Публикации о генах и старении (titles)
Human pluripotent stem cell (hPSC)-derived progenies are immature versions of cells, presenting a potential limitation to the accurate modelling of diseases associated with maturity or age. Hence, it is important to characterise how closely cells used in culture resemble their native counterparts. In order to select appropriate time points of retinal pigment epithelium (RPE) cultures that reflect native counterparts, we characterised the transcriptomic profiles of the hPSC-derived RPE cells from 1- and 12-month cultures. We differentiated the human embryonic stem cell line H9 into RPE cells, performed single-cell RNA-sequencing of a total of 16,576 cells to assess the molecular changes of the RPE cells across these two culture time points. Our results indicate the stability of the RPE transcriptomic signature, with no evidence of an epithelial-mesenchymal transition, and with the maturing populations of the RPE observed with time in culture. Assessment of Gene Ontology pathways revealed that as the cultures age, RPE cells upregulate expression of genes involved in metal binding and antioxidant functions. This might reflect an increased ability to handle oxidative stress as cells mature. Comparison with native human RPE data confirms a maturing transcriptional profile of RPE cells in culture. These results suggest that long-term in vitro culture of RPE cells allows the modelling of specific phenotypes observed in native mature tissues. Our work highlights the transcriptional landscape of hPSC-derived RPE cells as they age in culture, which provides a reference for native and patient samples to be benchmarked against.
Keywords
- Aging
- Human embryonic stem cell
- Human pluripotent stem cell
- Retinal pigment epithelium
- Single-cell RNA sequencing
Interstitial pneumonia was the first manifestation to be recognized as caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2); however, in just a few weeks, it became clear that the coronavirus disease-2019 (COVID-19) overrun tissues and more body organs than just the lungs, so much so that it could be considered a systemic pathology. Several studies reported the involvement of the conjunctiva, the gut, the heart and its pace, and vascular injuries such as thromboembolic complications and Kawasaki disease in children and toddlers were also described. More recently, it was reported that in a sample of 214 SARS-CoV-2 positive patients, 36.4% complained of neurological symptoms ranging from non-specific manifestations (dizziness, headache, and seizures), to more specific symptoms such hyposmia or hypogeusia, and stroke. Older individuals, especially males with comorbidities, appear to be at the highest risk of developing such severe complications related to the Central Nervous System (CNS) involvement. Neuropsychiatric manifestations in COVID-19 appear to develop in patients with and without pre-existing neurological disorders. Growing evidence suggests that SARS-CoV-2 binds to the human Angiotensin-Converting Enzyme 2 (ACE2) for the attachment and entrance inside host cells. By describing ACE2 and the whole Renin Angiotensin Aldosterone System (RAAS) we may better understand whether specific cell types may be affected by SARS-CoV-2 and whether their functioning can be disrupted in case of an infection. Since clear evidences of neurological interest have already been shown, by clarifying the topographical distribution and density of ACE2, we will be able to speculate how SARS-CoV-2 may affect the CNS and what is the pathogenetic mechanism by which it contributes to the specific clinical manifestations of the disease. Based on such evidences, we finally hypothesize the process of SARS-CoV-2 invasion of the CNS and provide a possible explanation for the onset or the exacerbation of some common neuropsychiatric disorders in the elderly including cognitive impairment and Alzheimer disease.
Keywords
- ACE2
- Alzheimer disease
- Ang(1-7)/Mas
- COVID-19
- RAAS
- SARS-CoV
- brain aging
- neurodegenerative and psychiatric disorders abstract
Naringenin is naturally isolated from citrus fruits possessing many pharmacological activities. However, little is known about the effect of naringenin on nonalcoholic steatohepatitis (NASH) in the model of metabolic syndrome. The present study is aimed to investigate the effect of naringenin on NASH in 12-mo-old male ApoE mice and its possible underlying mechanism. In vivo, 12-mo-old male ApoE mice were administrated with naringenin by intragastric gavage for 12 weeks. At the end of experiment, the blood samples and liver tissues were collected. Metabolic parameters in serum, levels of triglyceride, cholesterol and hydroxyproline, activities of antioxidant enzymes, and content of inflammatory cytokines (TNF-α and IL-6) in liver were examined by corresponding assay kits. Pathological changes in liver were observed by hematoxylin-eosin, oil red O, masson's trichrome, picro-sirius red and senescence β-galactosidase staining. Dihydroethidium was used for detection of reactive oxygen species (ROS). In vitro, AML-12 cells were treated with oleic acid in the presence or absence of naringenin for 24 h. Transfection of SIRT1 siRNA was also conducted in vitro. Lipid accumulation, cellular ROS generation, malondialdehyde content, antioxidant enzyme activities and secretion levels of TNF-α and IL-6 were examined. Both in vivo and in vitro, gene expressions were detected by real-time PCR or western blot. Naringenin administration improved metabolic parameters, suppressed hepatic steatosis, regulated expression of genes involved in lipid metabolism (FASN, SCD1, PPARα and CPT1α), reduced hepatic fibrosis and cell senescence, inhibited hepatic inflammation as evidenced by the decreased macrophage recruitment and content of TNF-α and IL-6, and reduced hepatic oxidative stress by suppressing ROS generation and normalizing activities of antioxidant enzymes. Notably, naringenin administration increased hepatic SIRT1 protein expression and activity along with the increased deacetylation of liver kinase B1 (LKB1), PGC1α and NF-κB. In vitro study, the benefits of naringenin on lipid accumulation, oxidative stress and inflammation were diminished by SIRT1 siRNA transfection. These results indicate that naringenin administration may be a potential curative therapy for NASH treatment and the activation of hepatic SIRT1-mediated signaling cascades is involved in its beneficial effects.
Keywords
- AML-12 cells
- Aging
- ApoE(−/−) mice
- Naringenin
- Nonalcoholic steatohepatitis
- SIRT1
With the rising number of hip surgeries, simple and cost-effective tools for surgery risk assessment are warranted. The analysis of heart rate variability (HRV) may not only provide critical insights into the general frailty of patients with hip surgery, but also allow for better differentiation of health profiles in different hip surgery groups. Using HRV analysis, the present study compared cardiovascular as well as anthropometric parameters between patients with hip surgery, the hip fracture surgery group (HFS) and the total hip arthroplasty group (THA), and a control group. 71 participants (56.3% women), aged 60-85 years, took part, divided into three groups-patients after hip surgery (21 HFS and 30 THA patients) and a control group (20 participants). Electrocardiogram was recorded at baseline and after the application of a physical stressor (grip strength). A 3 (group) × 2 (time) repeated measures ANOVA, and a chi square test were carried out to test for group differences. Higher weight (p = .002), body mass index (p = .001), and systolic blood pressure (p = .034) were found in THA patients compared to HFS patients. Lower calf circumference (p = .009) and diastolic blood pressure (p = .048) were observed for the HFS group compared to the control group. For cardiovascular parameters, significant differences emerged between the HFS group and the control group in HR (p = .005), SDNN (p = .034) and SD2 (p = .012). No significant differences in cardiovascular parameters were observed between the two hip surgery groups: neither at baseline nor during stressor recovery. While HRV seems to differentiate well between HFS patients and controls, more research with larger samples is needed to scrutinize similaritites and differences in cardiovascular profiles between HFS and THA patients.
Keywords
- Aging
- Cardiovascular reactivity
- Heart rate variability
- Hip fracture
- Total hip arthroplasty
Examining handgrip strength (HGS) asymmetry could extend the utility of handgrip dynamometers for screening future falls. We sought to determine the associations of HGS asymmetry on future falls in older Americans. The analytic sample included 10,446 adults aged at least 65 years from the 2006-2016 waves of the Health and Retirement Study. Falls were self-reported. A handgrip dynamometer measured HGS. The highest HGS on each hand was used for determining HGS asymmetry ratio: (non-dominant HGS/dominant HGS). Those with HGS asymmetry ratio < 1.0 had their ratio inverted to make all HGS asymmetry ratios ≥ 1.0. Participants were categorized into asymmetry groups based on their inverted HGS asymmetry ratio: (1) 0.0-10.0%, (2) 10.1-20.0%, (3) 20.1-30.0%, and (4) > 30.0%. Generalized estimating equations were used for the analyses. Every 0.10 increase in HGS asymmetry ratio was associated with 1.26 (95% confidence interval (CI) 1.07-1.48) greater odds for future falls. Relative to those with HGS asymmetry 0.0-10.0%, participants with HGS asymmetry > 30.0% had 1.15 (CI 1.01-1.33) greater odds for future falls; however, the associations were not significant for those with HGS asymmetry 10.1-20.0% (odds ratio: 1.06; CI 0.98-1.14) and 20.1-30.0% (odds ratio: 1.10; CI 0.99-1.22). Compared to those with HGS asymmetry 0.0-10.0%, participants with HGS asymmetry > 10.0% and > 20.0% had 1.07 (CI 1.01-1.16) and 1.12 (CI 1.02-1.22) greater odds for future falls, respectively. Asymmetric HGS, as a possible biomarker of impaired neuromuscular function, may help predict falls. We recommend that HGS asymmetry be considered in HGS protocols and fall risk assessments.
Keywords
- Aging
- Functional laterality
- Geriatric assessment
- Geriatrics
- Muscle strength dynamometer
Aging impairs the IGF-I signaling of bone marrow mesenchymal stem cells (bmMSCs), but the mechanism is unclear. Here, we found that the ability to auto-phosphorylate IGF-I receptor (IGF-IR) in response to IGF-I was decreased in the bmMSCs of aged donors. Conversely, data showed that decorin (DCN) expression was prominently increased in aged bmMSCs, and that under IGF-I treatment, DCN knockdown in serum-starved aged bmMSCs potentiated their mitogenic activity and IGF-IR auto-phosphorylation, whereas DCN overexpression in serum-starved adult bmMSCs decreased both activities. Co-immunoprecipitation assays suggested that IGF-I and DCN bound to IGF-IR in a competitive manner. Online MethPrimer predicted 4 CpG islands (CGIs) in the introns of [i]DCN[/i] gene. RT-qPCR and bisulfite sequencing showed that dimethyloxalylglycine, an inhibitor of DNA demethylation, increased [i]DCN[/i] mRNA expression and CGI-I methylation in adult bmMSCs, whereas 5-aza-2'-deoxycytidine, a DNA methylation inhibitor, decreased [i]DCN[/i] mRNA expression and CGI-I methylation in aged bmMSCs, and ultimately enhanced the proliferation of serum-starved aged bmMSCs under IGF-I stimulation. Thus, IGF-IR could be the prime target of aging in down-regulating the IGF-I signaling of bmMSCs, where DCN could be a critical mediator.
Keywords
- IGF-I
- aging
- bone marrow mesenchymal stem cell
- osteoporosis
- small leucine-rich proteoglycan
Frailty is a condition of elderly characterized by increased vulnerability to stressful events. Frail patients are more likely to have adverse events. The purposes of this study were to define frailty in patients aged ≥ 70 years with chronic coronary syndrome (CCS) and to evaluate mortality and prognostic significance of frailty in these patients. We included 99 patients, ≥ 70 years old (mean age 74±5.3 years), with diagnosis of CCS. They were followed-up for up to 12 months. The frailty score was evaluated according to the Canadian Study of Health and Aging (CSHA). All patients were divided as frail or non-frail. The groups were compared for their characteristics and clinical outcomes. Fifty patients were classified as frail, and 49 patients as non-frail. The 12-month Major Adverse Cardiac Events (MACE) rate was 69.4% in frail patients and 20% in non-frail patients. Frailty increases the risk for MACE as much as 3.48 times. Two patients died in the non-frail group and 11 patients died in the frail group. Frailty increases the risk for death as much as 6.05 times. When we compared the aforementioned risk factors by multivariate analysis, higher CSHA frailty score was associated with increased MACE and death (relative risk [RR] = 22.94, 95% confidence interval [CI] 3.33-158.19, P=0.001, for MACE; RR = 7.41, 95% CI 1.44-38.03, P=0.016, for death). Being a frail elderly CCS patient is associated with worse outcomes. Therefore, frailty score should be evaluated for elderly CCS patients as a prognostic marker.
Keywords
- Aging
- Canada
- Confidence Intervals
- Death
- Frail Elderly
- Frailty
- Heart
- Multivariate Analysis
- Prognosis
- Risk Factors
CD4 Foxp3 T maintain immune homeostasis, but distinct mechanisms underlying their functional heterogeneity during infections are driven by specific cytokine milieu. Here we show that MyD88 deletion in Foxp3 cells altered their function and resulted in increased fungal burden and immunopathology during oral [i]Candida albicans[/i] (CA) challenge. Excessive inflammation due to the absence of MyD88 in T coincided with a reduction of the unique population of IL-17A expressing Foxp3 cells (T 17) and an increase in dysfunctional IFN-γ /Foxp3 cells (T IFN-γ) in infected mice. Failure of MyD88 T to regulate effector CD4 T cell functions correlated with heightened levels of IFN-γ in CD4 T cells, as well as increased infiltration of inflammatory monocytes and neutrophils in oral mucosa [i]in vivo[/i]. Mechanistically, IL-1β/MyD88 signaling was required for the activation of IRAK-4, Akt, and mTOR, which led to the induction and proliferation of T 17 cells. In the absence of IL-1 receptor signaling, T 17 cells were reduced, but IL-6-driven expansion of T IFN-γ cells was increased. This mechanism was physiologically relevant during [i]Candida[/i] infection in aged mice, as they exhibited IL-1 receptor/MyD88 defect in Foxp3 cells, loss of p-mTOR T 17 cells and reduced levels of IL-1β in oral mucosa, which coincided with persistent tongue inflammation. Concurrent with T dysfunction, aging was associated with increased CD4 T cell hyperactivation and heightened levels of IL-6 in mice and humans in oral mucosa [i]in vivo[/i]. Taken together, our data identify IL-1β/MyD88/T axis as a new component that modulates inflammatory responses in oral mucosa. Also, dysregulation of this axis in an aging immune system may skew host defense towards an immunopathological response in mucosal compartments.
Keywords
- Candida
- Foxp3
- IL-1β
- Treg
- Treg17
- aging
- fungal infection
- senescence
Aging is a universal feature of life that is a major focus of scientific research and a risk factor in many diseases. A comprehensive understanding of the cellular and molecular mechanisms of aging are critical to the prevention of diseases associated with the aging process. Here, it is shown that MYSM1 is a key suppressor of aging and aging-related pathologies. MYSM1 functionally represses cellular senescence and the aging process in human and mice primary cells and in mice organs. MYSM1 mechanistically attenuates the aging process by promoting DNA repair processes. Remarkably, MYSM1 deficiency facilitates the aging process and reduces lifespan, whereas MYSM1 over-expression attenuates the aging process and increases lifespan in mice. The functional role of MYSM1 is demonstrated in suppressing the aging process and prolonging lifespan. MYSM1 is a key suppressor of aging and may act as a potential agent for the prevention of aging and aging-associated diseases.
Keywords
- DNA repair
- Myb‐like, SWIRM, and MPN domains‐containing protein 1 (MYSM1)
- aging
- senescence
- senescence‐associated secretory phenotype (SASP)
Skin undergoes constant self-renewal, and its functional decline is a visible consequence of aging. Understanding human skin aging requires in-depth knowledge of the molecular and functional properties of various skin cell types. We performed single-cell RNA sequencing of human eyelid skin from healthy individuals across different ages and identified eleven canonical cell types, as well as six subpopulations of basal cells. Further analysis revealed progressive accumulation of photoaging-related changes and increased chronic inflammation with age. Transcriptional factors involved in the developmental process underwent early-onset decline during aging. Furthermore, inhibition of key transcription factors HES1 in fibroblasts and KLF6 in keratinocytes not only compromised cell proliferation, but also increased inflammation and cellular senescence during aging. Lastly, we found that genetic activation of HES1 or pharmacological treatment with quercetin alleviated cellular senescence of dermal fibroblasts. These findings provide a single-cell molecular framework of human skin aging, providing a rich resource for developing therapeutic strategies against aging-related skin disorders.
Keywords
- HES1
- KLF6
- aging
- fibroblast
- keratinocyte
- quercetin
- senescence
- single-cell RNA sequencing
- skin
Cellular senescence is a stable cell cycle arrest induced by diverse triggers, including replicative exhaustion, DNA damaging agents, oncogene activation, oxidative stress, and chromatin disruption. With important roles in aging and tumor suppression, cellular senescence has been implicated also in tumor promotion. Here we show that certain multiwalled carbon nanotubes (MWCNTs), as fiber-like nanomaterials, can trigger cellular senescence in primary human mesothelial cells. Using in vitro approaches, we found manifestation of several markers of cellular senescence, especially after exposure to a long and straight MWCNT. These included inhibition of cell division, senescence-associated heterochromatin foci, senescence-associated distension of satellites, LMNB1 depletion, γH2A.X nuclear panstaining, and enlarged cells exhibiting senescence-associated β-galactosidase activity. Furthermore, genome-wide transcriptome analysis revealed many differentially expressed genes, among which were genes encoding for a senescence-associated secretory phenotype. Our results clearly demonstrate the potential of long and straight MWCNTs to induce premature cellular senescence. This finding may find relevance in risk assessment of workplace safety, and in evaluating MWCNT's use in medicine such as drug carrier, due to exposure effects that might prompt onset of age-related diseases, or even carcinogenesis.
Keywords
- alpha tubulin
- cellular senescence
- mesothelial cells
- microarray analysis
- multiwalled carbon nanotubes
- γH2A.X
Lung ultrasound (LUS) showed a promising role in the diagnosis and monitoring of patients hospitalized for novel coronavirus disease (COVID-19). However, no data are available on its role in elderly patients. The aim of this study was to evaluate the diagnostic and prognostic role of LUS in elderly patients hospitalized for severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) pneumonia. Consecutive elderly patients (age >65 years) hospitalized for COVID-19 were enrolled. Demographics, laboratory, comorbidity, and the clinical features of the patients were collected. All patients underwent LUS on admission to the ward. LUS characteristics have been analyzed. Uni- and multivariate analyses to evaluate predictors for in-hospital death were performed. Thirty-seven hospitalized elderly patients (19 men) with a diagnosis of SARS-CoV-2 infection were consecutively enrolled. The median age was 82 years (interquartile range 74.5-93.5). Ultrasound alterations were found in all patients enrolled; inhomogeneous interstitial syndrome with spared areas (91.9%) and pleural alterations (100%) were the most frequent findings. At univariate analysis, LUS score (hazard ratio [[[HR]]] 1.168, 95% CI 1.049-1.301) and pleural effusions (HR 3.995, 95% CI 1.056-15.110) were associated with in-hospital death. At multivariate analysis, only LUS score (HR 1.168, 95% CI 1.049-1.301) was independelty associated with in-hospital death. The LUS score's best cutoff for distinguishing patients experiencing in-hospital death was 17 (at multivariate analysis LUS score ≥17, HR 4.827, 95% CI 1.452-16.040). In-hospital death was significantly different according to the LUS score cutoff of 17 (p = 0.0046). LUS could play a role in the diagnosis and prognosis in elderly patients hospitalized for SARS-CoV-2 infection.
Keywords
- Aging
- Coronavirus disease
- Elderly
- Lung ultrasound
- Severe acute respiratory syndrome-coronavirus-2
In addition to performing digestion and nutrient absorption, the intestine serves as one of the first barriers to the external environment, crucial for protecting the host from environmental toxins, pathogenic invaders, and other stress inducers. The gene regulatory network (GRN) governing embryonic development of the endoderm and subsequent differentiation and maintenance of the intestine has been well-documented in C. elegans. A key regulatory input that initiates activation of the embryonic GRN for endoderm and mesoderm in this animal is the maternally provided SKN-1 transcription factor, an ortholog of the vertebrate Nrf-1 and -2, which, like C. elegans SKN-1, perform conserved regulatory roles in mediating a variety of stress responses across metazoan phylogeny. Other key regulatory factors in early gut development also participate in stress response as well as in innate immunity and aging and longevity. In this review, we discuss the intersection between genetic nodes that mediate endoderm/intestine differentiation and regulation of stress and homeostasis. We also consider how direct signaling from the intestine to the germline, in some cases involving SKN-1, facilitates heritable epigenetic changes, allowing transmission of adaptive stress responses across multiple generations. These connections between regulation of endoderm/intestine development and stress response mechanisms suggest that varying selective pressure exerted on the stress response pathways may influence the architecture of the endoderm GRN, thereby leading to genetic and epigenetic variation in early embryonic GRN regulatory events.
Keywords
- Caenorhabditis elegans
- Embryonic development
- Epigenetics inheritance
- Innate immunity
- Longevity
- Pleiotropy
- Stress
Cortical injury, such as stroke, causes neurotoxic cascades that lead to rapid death and/or damage to neurons and glia. Axonal and myelin damage in particular, are critical factors that lead to neuronal dysfunction and impair recovery of function after injury and can be exacerbated in the aged brain where white matter damage is prevalent. Therapies that can ameliorate myelin damage and promote repair by targeting oligodendroglia, the cells that produce and maintain myelin, may facilitate recovery after injury, especially in the aged brain where these processes are already compromised. We previously reported that a novel therapeutic, Mesenchymal Stem Cell derived extracellular vesicles (MSC-EVs), administered intravenously at both 24 h and 14 days after cortical injury reduced microgliosis (Go et al. 2019), reduced neuronal pathology (Medalla et al. 2020), and improved motor recovery (Moore et al. 2019) in aged female rhesus monkeys. Here, we evaluated the effect of treatment with MSC-EVs on changes in oligodendrocyte maturation and associated myelin markers in the sublesional white matter using immunohistochemistry, confocal microscopy, stereology, qRT-PCR, and ELISA. Compared to vehicle-treated control, EV-treated monkeys showed a reduction in the density of damaged oligodendrocytes. Further, EV-treatment was associated with enhanced myelin maintenance, evidenced by upregulation of myelin-related genes and increases in actively-myelinating oligodendrocytes in in sublesional white matter. These changes in myelination correlate with the rate of motor recovery, suggesting that improved myelin maintenance facilitates this recovery. Overall, our results suggest that EVs act on oligodendrocytes to support myelination and likely improve functional recovery after injury in the aged brain. SIGNIFICANCE: We previously reported that after cortical injury in the aged monkey brain, EVs reduce neuronal pathology (Medalla et al. 2020), microgliosis (Go et al. 2019), and facilitate recovery of function. However, the effect of injury on oligodendrocytes and myelination has not been characterized in the primate brain (Dewar et al. 1999; Sozmen et al. 2012; Zhang et al. 2013). In the present study, we assessed changes in myelination after cortical injury in these same aged monkeys. Our results show, for the first time, that MSC-EVs support recovery of function after cortical injury by enhancing myelin maintenance in the aged primate brain.
Keywords
- Aging
- Cortical injury
- Extracellular vesicles
- Monkeys
- Myelin
- Non-human primates
- Oligodendrocytes
- Stroke
- White matter
5-Aminolevulinic acid (ALA) is the rate-limiting intermediate in heme biosynthesis in vertebrate species; a reaction catalyzed by the mitochondrial ALA synthase 1 (ALAS1) enzyme. Previously we reported that knockdown of the ubiquitously expressed ALAS1 gene in mice disrupts normal glucose metabolism, attenuates mitochondrial function and results in a prediabetic like phenotype when animals pass 20-weeks of age (Saitoh et al., 2018). Contrary to our expectations, the cytosolic and mitochondrial heme content of ALAS1 heterozygous (A1+/-) mice were similar to WT animals. Therefore, we speculated that regulatory "free heme" may be reduced in an age dependent manner in A1 ± mice, but not total heme. Here, we examine free and total heme from the skeletal muscle and liver of WT and A1 ± mice using a modified acetone extraction method and examine the effects of aging on free heme by comparing the amounts at 8-12 weeks and 30-36 weeks of age, in addition to the mRNA abundance of ALAS1. We found an age-dependent reduction in free heme in the skeletal muscle and liver of A1 ± mice, while WT mice showed only a slight decrease in the liver. Total heme levels showed no significant difference between young and aged WT and A1 ± mice. ALAS1 mRNA levels showed an age-dependent reduction similar to that of free heme levels, indicating that ALAS1 mRNA expression levels are a major determinant for free heme levels. The free heme pools in skeletal muscle tissue were almost 2-fold larger than that of liver tissue, suggesting that the heme pool varies across different tissue types. The expression of heme oxygenase 1 (HO-1) mRNA, which is expressed proportionally to the amount of free heme, were similar to those of free heme levels. Taken together, this study demonstrates that the free heme pool differs across tissues, and that an age-dependent reduction in free heme levels is accelerated in mice heterozygous for ALAS1, which could account for the prediabetic phenotype and mitochondrial abnormality observed in these animals.
Keywords
- 5-Aminolevulinate synthase 1 (ALAS1)
- 5-Aminolevulinic acid (ALA)
- Aging
- Free heme
- Liver
- Skeletal muscle
Cellular reprogramming forcing the expression of pluripotency markers can reverse aging of cells but how molecular mechanisms through which reprogrammed cells alter aging-related cellular activities still remain largely unclear. In this study, we reprogrammed human synovial fluid-derived mesenchymal stem cells (MSCs) into induced pluripotent stem cells (iPSCs) using six reprogramming factors and reverted the iPSCs back to MSCs, as an approach to cell rejuvenation. Using the parental and reprogrammed MSCs as control nonrejuvenated and rejuvenated cells, respectively, for comparative analysis, we found that aging-related activities were greatly reduced in reprogrammed MSCs compared with those in their parental lines, indicating reversal of cell aging. Global transcriptome analysis revealed differences in activities of regulatory networks associated with inflammation and proliferation. Mechanistically, we demonstrated that, compared with control cells, the expression of GATA binding protein 6 (GATA6) in reprogrammed cells was attenuated, resulting in an increase in the activity of sonic hedgehog signaling and the expression level of downstream forkhead box P1 (FOXP1), in turn ameliorating cellular hallmarks of aging. Lower levels of GATA6 expression were also found in cells harvested from younger mice or lower passage cultures. Our findings suggest that GATA6 is a critical regulator increased in aged MSCs that controls the downstream sonic hedgehog signaling and FOXP1 pathway to modulate cellular senescence and aging-related activities.
Keywords
- aging
- cell signaling
- mesenchymal stem cells
- reprogramming
- transcription factors
Aging induces several stress response pathways to counterbalance detrimental changes associated with this process. These pathways include nutrient signaling, proteostasis, mitochondrial quality control and DNA damage response. At the cellular level, these pathways are controlled by evolutionarily conserved signaling molecules, such as 5'AMP-activated protein kinase (AMPK), mechanistic target of rapamycin (mTOR), insulin/insulin-like growth factor 1 (IGF-1) and sirtuins, including SIRT1. Peroxisome proliferation-activated receptor coactivator 1 alpha (PGC-1α), encoded by the [i]PPARGC1A[/i] gene, playing an important role in antioxidant defense and mitochondrial biogenesis, may interact with these molecules influencing lifespan and general fitness. Perturbation in the aging stress response may lead to aging-related disorders, including age-related macular degeneration (AMD), the main reason for vision loss in the elderly. This is supported by studies showing an important role of disturbances in mitochondrial metabolism, DDR and autophagy in AMD pathogenesis. In addition, disturbed expression of PGC-1α was shown to associate with AMD. Therefore, the aging stress response may be critical for AMD pathogenesis, and further studies are needed to precisely determine mechanisms underlying its role in AMD. These studies can include research on retinal cells produced from pluripotent stem cells obtained from AMD donors with the mutations, either native or engineered, in the critical genes for the aging stress response, including [i]AMPK[/i], [i]IGF1[/i], [i]MTOR[/i], [i]SIRT1[/i] and [i]PPARGC1A[/i].
Keywords
- AMD
- DNA damage response
- PGC-1α
- SIRT1
- age-related macular degeneration
- aging
- autophagy
- insulin/IGF-1
- mitochondrial quality control
- the aging stress response
The aim of this work was to examine the content of aryl hydrocarbon receptor interacting protein (AIP) in fibroblasts of human dermis from 20 weeks of pregnancy until 85 years old, and defining of a role of AIP in age-dependent changes in the number of fibroblasts in the dermis. AIP, proliferating cells nuclear antigen (PCNA) were detected with indirect immunohistochemical technique. Results showed that a portion of fibroblasts with positive staining for AIP in the dermis is gradually increased from 20 weeks of pregnancy until 85 years old. A total number and percent of PCNA positive fibroblasts in dermis decreased with progression of age. Most sufficient age-dependent reduction in a total and PCNA positive number of dermal fibroblast was observed from antenatal until 40 years of life. Correlation analysis showed that both age-dependent decrease in the number of fibroblasts and retardation of their proliferation are significantly associated with age-related increase in the number of AIP positive fibroblasts in dermis. Results allow to suggest that AIP is involved in age-dependent decrease in the number and proliferation of fibroblasts in human dermis.
Keywords
- AIP
- PCNA
- aging
- fibroblasts
- skin
Mitochondrial dysfunction causes energy deficiency and nigrostriatal neurodegeneration which is integral to the pathogenesis of Parkinson disease (PD). Clearance of defective mitochondria involves fission and ubiquitin-dependent degradation via mitophagy to maintain energy homeostasis. We hypothesize that LRRK2 (leucine-rich repeat kinase 2) mutation disrupts mitochondrial turnover causing accumulation of defective mitochondria in aging brain. We found more ubiquitinated mitochondria with aberrant morphology associated with impaired function in aged (but not young) LRRK2 knockin mutant mouse striatum compared to wild-type (WT) controls. LRRK2 mutant mouse embryonic fibroblasts (MEFs) exhibited reduced MAP1LC3/LC3 activation indicating impaired macroautophagy/autophagy. Mutant MEFs under FCCP-induced (mitochondrial uncoupler) stress showed increased LC3-aggregates demonstrating impaired mitophagy. Using a novel flow cytometry assay to quantify mitophagic rates in MEFs expressing photoactivatable [i]mito[/i]-PAmCherry, we found significantly slower mitochondria clearance in mutant cells. Specific LRRK2 kinase inhibition using GNE-7915 did not alleviate impaired mitochondrial clearance suggesting a lack of direct relationship to increased kinase activity alone. DNM1L/Drp1 knockdown in MEFs slowed mitochondrial clearance indicating that DNM1L is a prerequisite for mitophagy. DNM1L knockdown in slowing mitochondrial clearance was less pronounced in mutant MEFs, indicating preexisting impaired DNM1L activation. DNM1L knockdown disrupted mitochondrial network which was more evident in mutant MEFs. DNM1L-Ser616 and MAPK/ERK phosphorylation which mediate mitochondrial fission and downstream mitophagic processes was apparent in WT using FCCP-induced stress but not mutant MEFs, despite similar total MAPK/ERK and DNM1L levels. In conclusion, aberrant mitochondria morphology and dysfunction associated with impaired mitophagy and DNM1L-MAPK/ERK signaling are found in mutant LRRK2 MEFs and mouse brain. ATP: adenosine triphosphate; BAX: BCL2-associated X protein; CDK1: cyclin-dependent kinase 1; CDK5: cyclin-dependent kinase 5; CQ: chloroquine; CSF: cerebrospinal fluid; DNM1L/DRP1: dynamin 1-like; ELISA: enzyme-linked immunosorbent assay; FACS: fluorescence-activated cell sorting; FCCP: carbonyl cyanide-4-(trifluoromethoxy)phenylhydrazone; GAPDH: glyceraldehyde-3-phosphate dehydrogenase; LAMP2A: lysosomal-associated membrane protein 2A; LRRK2: leucine-rich repeat kinase 2; MAP1LC3/LC3: microtubule-associated protein 1 light chain 3; MAPK1/ERK2: mitogen-activated protein kinase 1; MEF: mouse embryonic fibroblast; MFN1: mitofusin 1; MMP: mitochondrial membrane potential; PAmCherry: photoactivatable-mCherry; PD: Parkinson disease; PINK1: PTEN induced putative kinase 1; PRKN/PARKIN: parkin RBR E3 ubiquitin protein ligase; RAB10: RAB10, member RAS oncogene family; RAF: v-raf-leukemia oncogene; SNCA: synuclein, alpha; TEM: transmission electron microscopy; VDAC: voltage-dependent anion channel; WT: wild type; SQSTM1/p62: sequestosome 1.
Keywords
- Aging
- Dnm1l/DRP1
- SQSTM1/p62
- knockin mice
- macroautophagy
- mitochondria dysfunction
- mitochondrial fission
- mitophagy
- parkinson disease
- ubiquitination
The interrelation of the processes of immunity and senescence now receives an unprecedented emphasis during the COVID-19 pandemic, which brings to the fore the critical need to combat immunosenescence and improve the immune function and resilience of older persons. Here we review the historical origins and the current state of the science of innate and adaptive immunity in aging and longevity. From the modern point of view, innate and adaptive immunity are not only affected by aging but also are important parts of its underlying mechanisms. Excessive levels or activity of antimicrobial peptides, C-reactive protein, complement system, TLR/NF-κB, cGAS/STING/IFN 1,3 and AGEs/RAGE pathways, myeloid cells and NLRP3 inflammasome, declined levels of NK cells in innate immunity, thymus involution and decreased amount of naive T-cells in adaptive immunity, are biomarkers of aging and predisposition factors for cellular senescence and aging-related pathologies. Long-living species, human centenarians, and women are characterized by less inflamm-aging and decelerated immunosenescence. Despite recent progress in understanding, the harmonious theory of immunosenescence is still developing. Geroprotectors targeting these mechanisms are just emerging and are comprehensively discussed in this article.
Keywords
- adaptive immunity
- aging
- innate immunity
- longevity
- resilience
Fluid intelligence (FI) involves abstract problem-solving without prior knowledge. Greater age-related FI decline increases Alzheimer's disease (AD) risk, and recent studies suggest that certain dietary regimens may influence rates of decline. However, it is uncertain how long-term food consumption affects FI among adults with or without familial history of AD (FH) or APOE4 (ɛ4). Observe how the total diet is associated with long-term cognition among mid- to late-life populations at-risk and not-at-risk for AD. Among 1,787 mid-to-late-aged adult UK Biobank participants, 10-year FI trajectories were modeled and regressed onto the total diet based on self-reported intake of 49 whole foods from a Food Frequency Questionnaire (FFQ). Daily cheese intake strongly predicted better FIT scores over time (FH-: β= 0.207, p < 0.001; ɛ4-: β= 0.073, p = 0.008; ɛ4+: β= 0.162, p = 0.001). Alcohol of any type daily also appeared beneficial (ɛ4+: β= 0.101, p = 0.022) and red wine was sometimes additionally protective (FH+: β= 0.100, p = 0.014; ɛ4-: β= 0.59, p = 0.039). Consuming lamb weekly was associated with improved outcomes (FH-: β= 0.066, p = 0.008; ɛ4+: β= 0.097, p = 0.044). Among at risk groups, added salt correlated with decreased performance (FH+: β= -0.114, p = 0.004; ɛ4+: β= -0.121, p = 0.009). Modifying meal plans may help minimize cognitive decline. We observed that added salt may put at-risk individuals at greater risk, but did not observe similar interactions among FH- and AD- individuals. Observations further suggest in risk status-dependent manners that adding cheese and red wine to the diet daily, and lamb on a weekly basis, may also improve long-term cognitive outcomes.
Keywords
- APOE4
- Aging
- Mediterranean diet
- cognitive decline
- functional food
- lamb
- nutrition policy
- preventive medicine
- red wine
- salt
Sirtuin 6 gene (SIRT6) is a longevity gene that is involved in a variety of metabolic pathways, but the relationship between SIRT6 methylation and longevity has not been clarified. We conducted a case-control study on 129 residents with a family history of longevity (1 of parents, themselves, or siblings aged ≥90 years) and 86 individuals without a family history of exceptional longevity to identify the association. DNA pyrosequencing was performed to analyze the methylation status of SIRT6 promoter CpG sites. qRT-PCR and ELISA were used to estimate the SIRT6 messenger RNA (mRNA) levels and protein content. Six CpG sites (P1-P6) were identified as methylation variable positions in the SIRT6 promoter region. At the P2 and P5 CpG sites, the methylation rates of the longevity group were lower than those of the control group (p < 0.001 and p = 0.009), which might be independent determinants of longevity. The mRNA and protein levels of SIRT6 decreased in the control group (p < 0.0001 and p = 0.038). The mRNA level negatively correlated with the methylation rates at the P2 (rs = -0.173, p = 0.011) and P5 sites (rs = -0.207, p = 0.002). Furthermore, the protein content positively correlated with the methylation rate at the P5 site (rs = 0.136, p = 0.046) but showed no significant correlation with the methylation rate at the P2 site. The low level of SIRT6 methylation may be a potential protective factor of Chinese longevity.
Keywords
- DNA Methylation
- Longevity
- Messenger RNA
- SIRT6
Aging increases risk for ischemic vascular diseases. Bone marrow-derived hematopoietic stem/progenitor cells (HSPCs) are known to stimulate vascular regeneration. Activation of either the Mas receptor (MasR) by angiotensin-(1-7) (Ang-(1-7)) or angiotensin-converting enzyme-2 (ACE2) stimulates vasoreparative functions in HSPCs. This study tested if aging is associated with decreased ACE2 expression in HSPCs and if Ang-(1-7) restores vasoreparative functions. Flow cytometric enumeration of Lin CD45 CD34 cells was carried out in peripheral blood of male or female individuals (22-83 years of age). Activity of ACE2 or the classical angiotensin-converting enzyme (ACE) was determined in lysates of HSPCs. Lin Sca-1 cKit (LSK) cells were isolated from young (3-5 months) or old (20-22 months) mice, and migration and proliferation were evaluated. Old mice were treated with Ang-(1-7), and mobilization of HSPCs was determined following ischemia induced by femoral ligation. A laser Doppler blood flow meter was used to determine blood flow. Aging was associated with decreased number (Spearman r = - 0.598, P < 0.0001, n = 56), decreased ACE2 (r = - 0.677, P < 0.0004), and increased ACE activity (r = 0.872, P < 0.0001) (n = 23) in HSPCs. Migration or proliferation of LSK cells in basal or in response to stromal-derived factor-1α in old cells is attenuated compared to young, and these dysfunctions were reversed by Ang-(1-7). Ischemia increased the number of circulating LSK cells in young mice, and blood flow to ischemic areas was recovered. These responses were impaired in old mice but were restored by treatment with Ang-(1-7). These results suggest that activation of ACE2 or MasR would be a promising approach for enhancing ischemic vascular repair in aging.
Keywords
- ACE2
- Aging
- Angiotensin-(1-7)
- Hematopoietic stem/progenitor cells
- Ischemia
Cellular senescence is defined as a stable, persistent arrest of cell proliferation. Here, we examine whether senescent cells can lose senescence hallmarks and reenter a reversible state of cell-cycle arrest (quiescence). We constructed a molecular regulatory network of cellular senescence based on previous experimental evidence. To infer the regulatory logic of the network, we performed phosphoprotein array experiments with normal human dermal fibroblasts and used the data to optimize the regulatory relationships between molecules with an evolutionary algorithm. From ensemble analysis of network models, we identified 3-phosphoinositide-dependent protein kinase 1 (PDK1) as a promising target for inhibitors to convert the senescent state to the quiescent state. We showed that inhibition of PDK1 in senescent human dermal fibroblasts eradicates senescence hallmarks and restores entry into the cell cycle by suppressing both nuclear factor κB and mTOR signaling, resulting in restored skin regeneration capacity. Our findings provide insight into a potential therapeutic strategy to treat age-related diseases associated with the accumulation of senescent cells.
Keywords
- PDK1
- cellular senescence
- network modeling
- skin aging
- systems biology
Aging is generally characterized as a gradual increase in tissue damage, which is associated with senescence and chronic systemic inflammation and is evident in a variety of age-related diseases. The extent to which such tissue damage is a result of a gradual decline in immune regulation, which consequently compromises the capacity of the body to repair damages, has not been fully explored. Whereas CD4 T lymphocytes play a critical role in the orchestration of immunity, thymus involution initiates gradual changes in the CD4 T-cell landscape, which may significantly compromise tissue repair. In this review, we describe the lifespan accumulation of specific dysregulated CD4 T-cell subsets and their coevolution with systemic inflammation in the process of declined immunity and tissue repair capacity with age. Then, we discuss the process of thymus involution-which appears to be most pronounced around puberty-as a possible driver of the aging T-cell landscape. Finally, we identify individualized T cell-based early diagnostic biomarkers and therapeutic strategies for age-related diseases.
Keywords
- Aging
- Chronic systemic inflammation
- Dysregulated CD4 T cells
- Immune-mediated repair
- Thymus
Late-onset asthma (LOA) is beginning to account for an increasing proportion of asthma patients, which is often underdiagnosed in the elderly. Studies on the possible relations between aging-related genes and LOA contribute to the diagnosis and treatment of LOA. Forkhead Box O3 (FOXO3) and TP53 are two classic aging-related genes. DNA methylation varies greatly with age which may play an important role in the pathogenesis of LOA. We supposed that the differentially methylated sites of FOXO3 and TP53 associated with clinical phenotypes of LOA may be useful biomarkers for the early screening of LOA. The mRNA expression and DNA methylation of FOXO3 and TP53 in peripheral blood of 43 LOA patients (15 mild LOA, 15 moderate LOA and 13 severe LOA) and 60 healthy controls (HCs) were determined. The association of methylated sites with age was assessed by Cox regression to control the potential confounders. Then, the correlation between differentially methylated sites (DMSs; p-value < 0.05) and clinical lung function in LOA patients was evaluated. Next, candidate DMSs combining with age were evaluated to predict LOA by receiver operating characteristic (ROC) analysis and principal components analysis (PCA). Finally, HDM-stressed asthma model was constructed, and DNA methylation inhibitor 5-Aza-2'-deoxycytidine (5-AZA) were used to determine the regulation of DNA methylation on the expression of FOXO3 and TP53. Compared with HCs, the mRNA expression and DNA methylation of FOXO3 and TP53 vary significantly in LOA patients. Besides, 8 DMSs from LOA patients were identified. Two of the DMSs, chr6:108882977 (FOXO3) and chr17:7591672 (TP53), were associated with the severity of LOA. The combination of the two DMSs and age could predict LOA with high accuracy (AUC values = 0.924). In HDM-stressed asthma model, DNA demethylation increased the expression of FOXO3 and P53. The mRNA expression of FOXO3 and TP53 varies significantly in peripheral blood of LOA patients, which may be due to the regulation of DNA methylation. FOXO3 and TP53 methylation is a suitable blood biomarker to predict LOA, which may be useful targets for the risk diagnosis and clinical management of LOA.
Keywords
- Aging
- DNA methylation
- FOXO3
- Late-onset asthma
- TP53
Ankyrin repeat and SOCS box (ASB) family members have a [i]C[/i]-terminal SOCS box and an [i]N[/i]-terminal ankyrin-related sequence of variable repeats. To date, the roles of ASB family members remain largely unknown. In the present study, by employing knockdown analysis, we investigated the effects of ASB7 on mouse oocyte meiosis. We show that specific depletion of ASB7 disrupts maturational progression and meiotic apparatus. In particular, abnormal spindle, misaligned chromosomes, and loss of cortical actin cap are frequently observed in ASB7-abated oocytes. Consistent with this observation, incidence of aneuploidy is increased in these oocytes. Meanwhile, confocal scanning reveals that loss of ASB7 impairs kinetochore-microtubule interaction and provokes the spindle assembly checkpoint during oocyte meiosis. Furthermore, we find a significant reduction of ASB7 protein in oocytes from aged mice. Importantly, increasing ASB7 expression is capable of partially rescuing the maternal age-induced meiotic defects in oocytes. Together, our data identify ASB7 as a novel player in regulating cytoskeletal organization and discover the potential effects of ASB7 on quality control of aging oocytes.
Keywords
- ASBs
- maternal aging
- meiosis
- oocyte
- reproduction
Further knowledge on modifiable aging risk factors is required to mitigate the increasing burden of age-related diseases in a rapidly growing global demographic of elderly individuals. We explored the effect of everyday exposure to polycyclic aromatic hydrocarbons (PAHs), which are fundamental constituents of air pollution, on cellular biological aging. This was determined via the analysis of leukocyte telomere length (LTL), mitochondrial DNA copy number (LmtDNAcn), and by the formation of anti-benzo[a]pyrene diolepoxide (B[a]PDE-DNA) adducts. The study population consisted of 585 individuals living in North-East Italy. PAH exposure (diet, indoor activities, outdoor activities, traffic, and residential exposure) and smoking behavior were assessed by questionnaire and anti-B[a]PDE-DNA by high-performance-liquid-chromatography. LTL, LmtDNAcn and genetic polymorphisms [glutathione S-transferase M1 and T1 (GSTM1; GSTT1)] were measured by polymerase chain reaction. Structural equation modelling analysis evaluated these complex relationships. Anti-B[a]PDE-DNA enhanced with PAH exposure (p = 0.005) and active smoking (p = 0.0001), whereas decreased with detoxifying GSTM1 (p = 0.021) and in females (p = 0.0001). Subsequently, LTL and LmtDNAcn reduced with anti-B[a]PDE-DNA (p = 0.028 and p = 0.018), particularly in males (p = 0.006 and p = 0.0001). Only LTL shortened with age (p = 0.001) while elongated with active smoking (p = 0.0001). Besides this, the most significant determinants of PAH exposure that raised anti-B[a]PDE-DNA were indoor and diet (p = 0.0001), the least was outdoor (p = 0.003). New findings stemming from our study suggest that certain preventable everyday life exposures to PAHs reduce LTL and LmtDNAcn. In particular, the clear association with indoor activities, diet, and gender opens new perspectives for tailored preventive measures in age-related diseases. Everyday life exposure to polycyclic aromatic hydrocarbons reduces leukocyte telomere length and mitochondrial DNA copy number through anti-B[a]PDE-DNA adduct formation.
Keywords
- Biological aging
- DNA adduct
- Mitochondrial DNA copy number
- Polycyclic aromatic hydrocarbon
- Structural equation modelling
- Telomere length
Food insecurity is associated with increased morbidity and mortality in people living with HIV on antiretroviral therapy, but its relationship with immune dysregulation, a hallmark of HIV infection and comorbidity, is unknown. In 241 women participating in the Women's Interagency HIV Study, peripheral blood mononuclear cells were characterized by flow cytometry to identify cell subsets, comprising surface markers of activation (%CD38+HLADR+), senescence (%CD57+CD28-), exhaustion (%PD-1+), and co-stimulation (%CD57- CD28+) on CD4+ and CD8+ T-cells. Mixed-effects linear regression models were used to assess the relationships of food insecurity with immune outcomes, accounting for repeated measures at up to three study visits and adjusting for sociodemographic and clinical factors. At the baseline study visit, 71% of participants identified as non-Hispanic Black, 75% were virally suppressed, and 43% experienced food insecurity. Food insecurity was associated with increased activation of CD4+ and CD8+ T-cells, increased senescence of CD8+ T-cells, and decreased co-stimulation of CD4+ and CD8+ T-cells (all p<0.05), adjusting for age, race/ethnicity, income, education, substance use, smoking, HIV viral load, and CD4 cell count. In stratified analyses, the association of food insecurity with CD4+ T-cell activation was more pronounced in women with uncontrolled HIV (viral load >40 copies/mL and CD4 <500 cells/mm 3), but remained statistically significant in those with controlled HIV. Food insecurity may contribute to the persistent immune activation and senescence in women living with HIV on antiretroviral therapy, independently of HIV control. Reducing food insecurity may be important for decreasing non-AIDS-related disease risk in this population.
Keywords
- HIV
- exhaustion
- food insecurity
- immune activation
- senescence
Aging of the uterine endometrium is a critical factor that affects reproductive success, but the mechanisms associated with uterine aging are unclear. In this study, we conducted a qualitative examination of age-related changes in endometrial tissues and identified candidate genes as markers for uterine aging. Gene expression patterns were assessed by two RNA sequencing experiments using uterine tissues from wild type (WT) C57BL/6 mice. Gene expression data obtained by RNA-sequencing were validated by real-time PCR. Genes expressing the pro-inflammatory cytokines Il17rb and chemokines Cxcl12 and Cxcl14 showed differential expression between aged WT mice and a group of mice composed of 5 and 8 week-old WT (young) animals. Protein expression levels of the above-mentioned genes and of IL8, which functions downstream of IL17RB, were analysed by quantitative immunohistochemistry of unaffected human endometrium tissue samples from patients in their 20 s and 40 s (10 cases each). In the secretory phase samples, 3,3'- diaminobenzidine (DAB) staining intensities of IL17RB, CXCL12 and CXCL14 for patients in their 40 s were significantly higher than that for patients in their 20 s, as detected by a Mann Whitney U test. These results suggest that these genes are candidate markers for endometrial aging and for prediction of age-related infertility, although confirmation of these findings is needed in larger studies involving fertile and infertile women.
Keywords
- CXCL12
- CXCL14
- IL17RB
- endometrial cell aging
- infertility
- quantitative
immunohistochemistry
Chrysomya albiceps (Wiedemann 1819) is one of the most important insects in forensic entomology. Its larval developmental and survival rates are influenced by nutritional resources, temperature, humidity, and geographical regions. The present study investigated the possibility of relying on body size and cuticular hydrocarbon composition as indicators for age estimation of the different larval instars of C. albiceps. Larvae were maintained in standardized laboratory conditions at different experimental temperatures. All larval instars (first, second, and third) were randomly collected for measuring their body sizes and for estimating their cuticular hydrocarbons at different rearing temperatures (30, 35, 40, and 45°C) using gas chromatography-mass spectrometry (GC-MS). Results indicated that the duration of larval stage was temperature dependent as it gradually decreased on increasing the rearing temperature (30, 35, and 40°C) except 45°C at which larval development was ceased. In contrary, larval body size, in terms of length, width, and weight, was temperature dependent as it gradually increased with larval development on increasing rearing temperature except at 45°C at which larval development was ceased. The GC-MS showed a significant difference in the extracted components of cuticular hydrocarbons between different larval instars reared in the same temperature and between the same larval instar that reared at different temperatures. Furthermore, the highest and lowest amounts of cuticular hydrocarbons were detected at 35 and 40°C, respectively. Overall, larval body size and cuticular hydrocarbon components were temperature dependent within the range 30-40°C, which may suggest them as possible reliable age indicators for estimating the postmortem interval in the field of medicolegal entomology.
Keywords
Chrysomya albiceps
- body size
- cuticular hydrocarbon
- forensic
- larval longevity
The ability to distinguish resident microglia from infiltrating myeloid cells by flow cytometry-based surface phenotyping is an important technique for examining age-related neuroinflammation. The most commonly used surface markers for the identification of microglia include CD45 (low-intermediate expression), CD11b, Tmem119, and P2RY12. In this study, we examined changes in expression levels of these putative microglia markers in in vivo animal models of stroke, cerebral amyloid angiopathy (CAA), and aging as well as in an ex vivo LPS-induced inflammation model. We demonstrate that Tmem119 and P2RY12 expression is evident within both CD45 and CD45 myeloid populations in models of stroke, CAA, and aging. Interestingly, LPS stimulation of FACS-sorted adult microglia suggested that these brain-resident myeloid cells can upregulate CD45 and downregulate Tmem119 and P2RY12, making them indistinguishable from peripherally derived myeloid populations. Importantly, our findings show that these changes in the molecular signatures of microglia can occur without a contribution from the other brain-resident or peripherally sourced immune cells. We recommend future studies approach microglia identification by flow cytometry with caution, particularly in the absence of the use of a combination of markers validated for the specific neuroinflammation model of interest. The subpopulation of resident microglia residing within the "infiltrating myeloid" population, albeit small, may be functionally important in maintaining immune vigilance in the brain thus should not be overlooked in neuroimmunological studies.
Keywords
- Aging
- Brain infiltrating myeloid cells
- CD45
- Cerebral amyloid angiopathy
- Microglia
- Neuroinflammation
- P2RY12
- Stroke
- Tmem119
In the current study, we aimed to explore the correlation between TRIM27 and breast cancer prognosis, as well as the functions of TRIM27 in breast cancer and their underlying mechanisms. Bioinformatics analyses were used to examine the correlation between TRIM27 and breast cancer prognosis. Moreover, TRIM27 knockdown and overexpression in breast cancer cells were performed to investigate its functions in breast cancer. Tamoxifen (TAM) was applied to evaluate the influence of TRIM27 on chemoresistance of breast cancer cells, while co-immunoprecipitation (coIP) was performed to identify the E3 ubiquitin ligase capability of TRIM27. High expression of TRIM27 was found in non-triple-negative breast cancer (non-TNBC) tumor tissues and was positively correlated with the mortality of non-TNBC patients. Moreover, TRIM27 could suppress non-TNBC cell apoptosis and senescence, promote cell viability and tumor growth, counteract the anti-cancer effects of TAM, and mediate ubiquitination of p21. In addition, EP300 could enhance the expression of TRIM27 and its transcription promoter H3K27ac. TRIM27, through ubiquitination of p21, might serve as a prognostic biomarker for non-TNBC prognosis. TRIM27 functions as a novel oncogene in non-TNBC cellular processes, especially suppressing cell senescence and interfering with non-TNBC chemoresistance.
Keywords
- EP300
- TRIM27
- breast cancer
- cell apoptosis
- cell senescence
- chemoresistance
- p21
- prognosis
- transcription
- ubiquitination
Acquired immune responses mediated by CD4 T cells contribute to the initiation and progression of acute coronary syndrome (ACS). ACS patients show acquired immune system abnormalities that resemble the characteristics of autoimmune dysfunction described in the elderly. This study aimed to investigate the role of premature CD4 T cells senescence in ACS and the underlying mechanism. We compared the immunological status of 25 ACS patients, 15 young healthy individuals (C1), and 20 elderly individuals with absence of ACS (C2). The percentages of CD4 T lymphocyte subsets (including naïve, regulatory, memory and effector T cells) in peripheral blood were analyzed. In ACS patients, a significant expansion of CD4 CD28 effector T cells and a decline of CD4 CD25 CD62L Treg cells were observed. In addition, patients with ACS showed an accelerated loss of CD4 CD45RA CD62L naïve T cells and a compensatory increase in the number of CD4 CD45RO memory T cells. ACS patients demonstrated no significant difference in frequency of T cell receptor excision circles (TRECs) compared to age-matched healthy volunteers. The expression of p16 was increased while CD62L was decreased in CD4 CD28 T cells of ACS patients. Compared to healthy donors, ACS patients demonstrated the lowest telomerase activity in both CD4 CD28 and CD4 CD28 T cells. The serum levels of C-reactive protein, Cytomegalovirus IgG, [i]Helicobactor pylori[/i] IgG and [i]Chlamydia pneumonia[/i] IgG were significantly higher in ACS patients. The results suggested that the percentage of CD4 T cell subpopulations correlated with chronic infection, which contributes to immunosenescence. In conclusion, chronic infection induced senescence of premature CD4 T cells, which may be responsible for the development of ACS.
Keywords
- CD28null T cells
- CD4+ T cells
- acute coronary syndrome
- immunosenescence
- infection
Dry eye disease (DED), one of the most prevalent conditions among the elderly, is a chronic inflammatory disorder that disrupts tear film stability and causes ocular surface damage. Aged C57BL/6J mice spontaneously develop DED. Rapamycin is a potent immunosuppressant that prolongs the lifespan of several species. Here, we compared the effects of daily instillation of eyedrops containing rapamycin or empty micelles for three months on the aged mice. Tear cytokine/chemokine profile showed a pronounced increase in vascular endothelial cell growth factor-A (VEGF-A) and a trend towards decreased concentration of Interferon gamma (IFN)-γ in rapamycin-treated groups. A significant decrease in inflammatory markers in the lacrimal gland was also evident ([i]IFN-γ[/i], [i]IL-12[/i], [i]CIITA[/i] and [i]Ctss[/i]); this was accompanied by slightly diminished [i]Unc-51 Like Autophagy Activating Kinase 1[/i] ([i]ULK1[/i]) transcripts. In the lacrimal gland and draining lymph nodes, we also observed a significant increase in the CD45 CD4 Foxp3 cells in the rapamycin-treated mice. More importantly, rapamycin eyedrops increased conjunctival goblet cell density and area compared to the empty micelles. Taken together, evidence from these studies indicates that topical rapamycin has therapeutic efficacy for age-associated ocular surface inflammation and goblet cell loss and opens the venue for new investigations on its role in the aging process of the eye.
Keywords
- aging
- dry eye
- goblet cell
- inflammation
- lacrimal gland
- ocular surface
- rapamycin
In this report, we describe the implementation and short-term outcomes of a Special Populations Consultation Service within the University of California, Los Angeles (UCLA) Clinical and Translational Science Institute (CTSI). With the goal of increasing the quality and quantity of special population (SP) research, the UCLA CTSI Integrating Special Populations program designed a consultation service to support faculty and trainees conducting research involving one of three CTSI "special populations:" children, older adults, and/or minority; underserved; or health disparity populations. The Special Populations Consultation Service offers three types of activities: grant proposal studios, career consultations, and project reviews. UCLA CTSI faculty with appropriate content expertise serve as consultants. We evaluated this consultation model using satisfaction surveys and by quantifying funded grants and reported changes in career goals in SP research. Between 2016 and 2019, the Special Populations Consultation Service provided 59 consultations including 42 grant studios and was used by researchers at all levels from all four UCLA CTSI institutions. Recipients rated the consultations very highly. Funding success rates were 57% following K-level grant studios and 28% following R-level grant studios. Users of project and career consultations commonly attributed career accomplishments in part to their consultation experiences. The SP Consultation Service is feasible and acceptable and appears to enhance careers of investigators studying special populations.
Keywords
- faculty development
- geriatrics
- grant review
- grant studio
- pediatrics
- peer review
- research consultation service
- special populations
- underrepresented minorities
Menstrual blood (MB) is a common and important type of forensic evidence, especially in sexual assault cases. MB is composed of peripheral blood (PB), vaginal fluid, and endometrial cells of the uterine wall. In forensic investigations, the differentiation of MB and PB can determine whether the blood present is a result of tissue damage from an assault or a natural cause and thus help to reconstruct the event. Understanding how menstrual blood changes is necessary to develop a method for bloodstain aging. Fluorescence spectroscopy, a promising spectroscopic method for bloodstain analysis, was used to probe the biochemical changes that occur over time in menstrual bloodstains. It was found that steady-state fluorescence spectra underwent significant changes over first nine hours post deposition. The underlying mechanism of fluorescence changes was proposed to involve the kinetic transformation of three fluorophores: tryptophan, nicotinamide adenine dinucleotide and flavins.
Keywords
- Aging
- Analytical methods
- Blood
- Fluorescence spectroscopy
- Forensics
Age-associated decline of the immune system is referred to as immunosenescence. The E3 ligase RING finger 10 (RNF10) has long been associated with the innate immune response, but a potential role in immunosenescence has not previously been reported. In the present study, we identified that RNF10 expression is lower in aged mouse macrophages than in young cells. After lipopolysaccharide (LPS) stimulation, RNF10 expression remained at a basal low level in aged mouse cells, but declined sharply in young mouse cells. Knockdown of RNF10 enhanced both the nuclear factor-κB (NF-κB) and interferon regulatory factor 3 (IRF3) signaling pathways and thus enhanced proinflammatory cytokines and type I interferons (IFN-I) in macrophages, promoting clearance of L. monocytigenes. These findings indicate that dysregulated expression of RNF10 is associated with age-associated immune dysfunction, and RNF10 may thus be a potential target for the treatment of age-related inflammatory diseases.
Keywords
- E3 ubiquitin ligase
- RNF10
- immunosenescence
- inflammation
- macrophages
Ectopic expression of FOREVER YOUNG FLOWER (FYF) delays floral senescence and abscission in transgenic Arabidopsis. To analyze the FYF function in Phalaenopsis orchids, two FYF-like genes (PaFYF1/2) were identified. PaFYF1/2 were highly expressed in young Phalaenopsis flowers, and their expression decreased significantly afterward until flower senescence. This pattern was strongly correlated with the process of flower senescence and revealed that PaFYF1/2 function to suppress senescence/abscission during early flower development. Interestingly, in flowers, PaFYF1 was consistently expressed less in petals than in lips/sepals, whereas PaFYF2 was expressed relatively evenly in all flower organs. This difference suggests a regulatory modification of the functions of PaFYF1 and PaFYF2 during Phalaenopsis flower evolution. Delayed flower senescence and abscission, which were unaffected by ethylene treatment, were observed in 35S::PaFYF1/2 and 35S::PaFYF1/2+SRDX transgenic Arabidopsis plants due to downregulation of the ethylene signaling and abscission-associated genes EDF1-4, IDA and BOP1/2. These results suggest a possible repressor role for Phalaenopsis PaFYF1/2 in controlling floral senescence/abscission by suppressing ethylene signaling and abscission-associated genes. To further validate the function of PaFYF1/2, PaFYF1/2-VIGS (virus-induced gene silencing) Phalaenopsis were generated and analyzed. Promotion of senescence and abscission was observed in PaFYF1/2-VIGS Phalaenopsis flowers by the upregulation of PeEDF1/2, PeSAG39 and PeBOP1/2 expression, early occurrence of greening according to their increased chlorophyll content and reduction of water content in flower organs. Our results support that PaFYF1/2 function as transcriptional repressors to prohibit flower senescence and abscission in Phalaenopsis.
Keywords
FOREVER YOUNG FLOWER
Phalaenopsis orchids
- Abscission
- Ethylene responses
- MADS-box gene
- Senescence
Old skeletal muscle exhibits decreased anabolic sensitivity, eventually contributing to muscle wasting. Besides anabolism, also muscle inflammation and catabolism are critical players in regulating the old skeletal muscle's sensitivity. Omega-3 fatty acids (ω-3) are an interesting candidate to reverse anabolic insensitivity via anabolic actions. Yet, it remains unknown whether ω-3 also attenuates muscle inflammation and catabolism. The present study investigates the effect of ω-3 supplementation on muscle inflammation and metabolism (anabolism/catabolism) upon resistance exercise (RE). Twenty-three older adults (OA) (65-84yr;8♀) were randomized to receive ω-3 (~3g·d -1) or corn oil (PLAC) and engaged in a 12-wk RE program (3x·wk -1). Before and after intervention, muscle volume, strength and systemic inflammation were assessed, and muscle biopsies were analysed for markers of anabolism, catabolism and inflammation. Isometric knee-extensor strength increased in ω-3 (+12.2%), but not in PLAC (-1.4%; pinteraction=0.015), whereas leg press strength improved in both conditions (+27.1%; ptime<0.001). RE, but not ω-3, decreased inflammatory (p65NF-κB) and catabolic (FOXO1, LC3b) markers, and improved muscle quality. Yet, muscle volume remained unaffected by RE and ω-3. Accordingly, muscle anabolism (mTORC1) and plasma CRP remained unchanged by RE and ω-3, whereas serum IL-6 tended to decrease in ω-3 (pinteraction=0.07). These results show that, despite no changes in muscle volume, RE-induced gains in isometric strength can be further enhanced by ω-3. However, ω-3 did not improve RE-induced beneficial catabolic or inflammatory adaptations. Irrespective of muscle volume, gains in strength (primary criterion for sarcopenia) might be explained by changes in muscle quality due to muscle inflammatory or catabolic signaling.
Keywords
- Muscle wasting
- aging
- anabolic resistance
- inflammation
- resistance training
- sarcopenia
An adequate development of the placenta includes trophoblast differentiation with the processes of trophoblast migration, invasion, cellular senescence and apoptosis which are all crucial to establishing a successful pregnancy. Altered placental development and function lead to placental diseases such as preeclampsia (PE) which is mainly characterized by insufficient trophoblast invasion and abnormally invasive placenta (AIP) disorders ([i]Placenta accreta[/i], [i]increta[/i], or [i]percreta)[/i] which are characterized by excessive trophoblast invasion. Both of them will cause maternal and fetal morbidity/mortality. However, the etiology of these diseases is still unclear. Our previous study has shown that the matricellular protein [i]nephroblastoma overexpressed[/i] (NOV, CCN3) induces G0/G1 cell cycle arrest, drives trophoblast cells into senescence and activates FAK and Akt kinases resulting in reduced cell proliferation and enhanced migration capability of the human trophoblast cell line SGHPL-5. The present study focuses on whether CCN3 can alter cell cycle-regulated pathways associated with trophoblast senescence and invasion activity in pathological versus gestational age-matched control placentas. Cell cycle regulator proteins were investigated by immunoblotting and qPCR. For localization of CCN3, p16, p21, and Cyclin D1 proteins, co-immunohistochemistry was performed. In early-onset PE placentas, CCN3 was expressed at a significantly lower level compared to gestational age-matched controls. The decrease of CCN3 level is associated with an increase in p53, Cyclin E1 and pRb protein expression, whereas the level of cleaved Notch-1, p21, Cyclin D1, pFAK, pAKT, and pmTOR protein decreased. In term AIP placentas, the expression of CCN3 was significantly increased compared to matched term controls. This increase was correlated to an increase in p53, p16, p21, Cyclin D1, cleaved Notch-1, pFAK, pAkt, and pmTOR whereas pRb was significantly decreased. However, in late PE and early AIP placentas, no significant differences in CCN3, p16, p21, Cyclin D1, p53, and cleaved Notch-1 expression were found when matched to appropriate controls. CCN3 expression levels are correlated to markers of cell cycle arrest oppositely in PE and AIP by activating the FAK/AKT pathway in AIP or down-regulating in PE. This may be one mechanism to explain the different pathological features of placental diseases, PE and AIP.
Keywords
- CCN3
- abnormally invasive placenta
- invasion
- preeclampsia
- senescence
- trophoblast
Mesenchymal stromal cell (MSC) transplantation is a form of the stem-cell therapy that has shown beneficial effects for many diseases. The use of stem-cell therapy, including MSC transplantation, however, has limitations such as the tumorigenic potential of stem cells and the lack of efficacy of aged autologous cells. An ideal therapeutic approach would keep the beneficial effects of MSC transplantation while circumventing the limitations associated with the use of intact stem cells. This study provides proof-of-concept evidence that MSC-derived extracellular vesicles represent a promising platform to develop an acellular therapeutic approach that would just do that. Extracellular vesicles are membranous vesicles secreted by MSCs and contain bioactive molecules to mediate communication between different cells. Extracellular vesicles can be taken up by recipient cells, and once inside the recipient cells, the bioactive molecules are released to exert the beneficial effects on the recipient cells. This study, for the first time to our knowledge, shows that extracellular vesicles secreted by MSCs recapitulate the beneficial effects of MSCs on vascular repair and promote blood vessel regeneration after ischemic events. Furthermore, MSCs from aged donors can be engineered to produce extracellular vesicles with improved regenerative potential, comparable to MSCs from young donors, thus eliminating the need for allogenic young donors for elderly patients.
Keywords
- BM, bone marrow
- CVD, cardiovascular disease
- EC, endothelial cell
- EPC, endothelial progenitor cell
- EV, extracellular vesicle
- FBS, fetal bovine serum
- MEM, minimum essential medium
- MI, myocardial infarction
- MSC, mesenchymal stromal cell
- NTA, nanotracking analysis
- PBS, phosphate-buffered saline
- TEV, tailored extracellular vesicle
- VEGF, vascular endothelial growth factor
- acellular
- angiogenesis
- extracellular vesicles
- lin− BMC, lineage negative bone marrow cell
- miR, microRNA
- qPCR, quantitative transcription polymerase chain reaction
- regeneration
- senescence
Animals tend to increase in body weight and body condition score (BCS) with aging. Serum diagnostic markers related to energy metabolism may show changes even in healthy cats with aging. Seventy domestic cats were recruited for this study. Based upon the modified AAFP-AAHA Feline Life Stage Guidelines, animals were divided into six groups: Junior (7 months-2 years), Prime (3 -6 years), Mature (7-10 years), Senior (11-14 years), Geriatric-obese (15 years ≤) and Geriatric-thin (15 years ≤). Their body condition scores (BCS) ranged from 3/9 to 9/9. Changes in metabolites, inflammatory markers, hormone concentrations and enzyme activities related to energy metabolism were investigated in serum of 70 domestic cats of various ages. Serum glucose (GLU) concentrations in the Mature, Senior, and Geriatric-obese groups were significantly higher than those in the Junior group. Serum amyloid A (SAA) concentrations in the Geriatric-thin group were significantly increased compared with the Junior group. SAA concentrations in the Geriatric-obese group tended to increase although there were no statistically significant differences. In the Mature, Senior, Geriatric-obese and Geriatric-thin groups, malate dehydrogenase/lactate dehydrogenase (M/L) ratio, an energy metabolic indicator, tended to decrease compared with the Junior group. In the Senior group, triglyceride (TG) concentrations were significantly increased compared with the Junior group. In the Geriatric-obese and Geriatric-thin groups, blood urea nitrogen (BUN) concentrations were significantly increased compared with the Junior group. In the Geriatric-obese group, albumin (ALB) concentrations were decreased compared with the Junior group. Aged domestic cats tend to increase in body weight and BCS. In addition, serum GLU, TG, SAA, and BUN concentrations increased and serum ALB concentrations and M/L ratio decreased. These diagnostic markers may be useful to detect small changes related to energy metabolism with aging that may cause obesity with light inflammation in healthy cats.
Keywords
- M/L ratio
- SAA
- aging
- domestic cats
- obesity
Aging is characterized by reduced immune responses, a process known as immunosenescence. Shortly after their generation, antigen-experienced adaptive immune cells, such as CD8 and CD4 T cells, migrate into the bone marrow (BM), in which they can be maintained for long periods of time within survival niches. Interestingly, we recently observed how oxidative stress may negatively support the maintenance of immunological memory in the BM in old age. To assess whether the generation and maintenance of immunological memory could be improved by scavenging oxygen radicals, we vaccinated 18-months (old) and 3-weeks (young) mice with alum-OVA, in the presence/absence of antioxidants vitamin C (Vc) and/or N-acetylcysteine (NAC). To monitor the phenotype of the immune cell population, blood was withdrawn at several time-points, and BM and spleen were harvested 91 days after the first alum-OVA dose. Only in old mice, memory T cell commitment was boosted with some antioxidant treatments. In addition, oxidative stress and the expression of pro-inflammatory molecules decreased in old mice. Finally, changes in the phenotype of dendritic cells, important regulators of T cell activation, were additionally observed. Taken together, our data show that the generation and maintenance of memory T cells in old age may be improved by targeting oxidative stress.
Keywords
- NAC
- T cells
- aging
- antioxidants
- immunosenescence
- vaccination
- vitamin C
Although the Klotho gene is recognized as an aging-suppressor gene, the clinical significance of its soluble product, soluble Klotho, in coronary artery disease (CAD) has not been completely determined. The relationship between soluble Klotho and coronary artery calcification (CAC) was investigated in patients with stable CAD. CAC in culprit lesions was analyzed in 75 non-dialysis patients with stable CAD who were scheduled for percutaneous coronary intervention (PCI) following intravascular ultrasound (IVUS). The main outcome measure was the calcium index (CalcIndex), a volumetric IVUS-derived measure of total calcification per culprit lesion. A low CalcIndex was defined as a first-quartile calcium index (<0.042). Patients were divided into two groups according to the median serum Klotho value: low Klotho (n = 37, ≤460 pg/mL) and high Klotho (n = 38, >460 pg/mL). The CalcIndex was significantly lower in patients with high than with low Klotho. Patients with high Klotho had a significantly higher prevalence of a low CalcIndex than those with low Klotho. The number of angiographic moderate-severe CACs in whole coronary arteries was significantly decreased in patients with high Klotho compared to low Klotho. Serum Klotho levels correlated significantly and inversely with the CalcIndex. This relationship was pronounced in patients with estimated glomerular filtration rate <60 mL/min/1.73 m . Logistic regression analysis showed that high Klotho was associated with a low CalcIndex independent of classical coronary risk factors and markers of mineral metabolism. High serum soluble Klotho levels are associated with a low degree of CAC in non-dialysis, stable CAD patients treated by PCI.
Keywords
- Aging
- Coronary artery calcification
- Intravascular ultrasound
- Klotho
Intervertebral disc degeneration (IDD) represents major cause of low back pain. Quercetin (QUE) is one of the approved senolytic agents. In this study, we evaluated the protective effects of QUE on IDD development and its underlying mechanism. Effects of senolytic agent QUE on the viability of nucleus pulposus cells (NPCs) were measured by CCK-8 assays and EdU staining. The senescence associated secreted phenotype (SASP) factors expressions were measured by qPCR, western blot, and ELISA; and NF-κB pathway was detected by immunofluorescence and western blot. Molecular docking was applied to predict the interacting protein of QUE; while Nrf2 was knocked down by siRNAs to confirm its role in QUE regulated senescence phenotype. X-ray, MRI, Hematoxylin-Eosin and Safranin O-Fast green staining were performed to evaluate the therapeutic effects of QUE on IDD in the puncture-induced rat model. In in vitro experiments, QUE inhibited SASP factors expression and senescence phenotype in IL-1β-treated NPCs. Mechanistically, QUE suppressed IL-1β induced activation of the NF-κB pathway cascades; it was also demonstrated in molecular docking and knock down studies that QUE might bind to Keap1-Nrf2 complex to suppress NF-κB pathway. In vivo, QUE ameliorated the IDD process in the puncture-induced rat model. Together the present work suggests that QUE inhibits SASP factors expression and senescence phenotype in NPCs and ameliorates the progression of IDD via the Nrf2/NF-κB axis, which supports senolytic agent QUE as a potential therapeutic agent for the treatment of IDD.
Keywords
- Intervertebral disc degeneration
- NF-κB pathway
- Nrf2
- Quercetin
- Senescence
Aging processes affect the brain in many ways, ranging from cellular to functional levels which lead to cognitive decline and increased oxidative stress. The aim of this study was to investigate the potentials of [i]Lactobacillus plantarum[/i] DR7 on brain health including cognitive and memory functions during aging and the impacts of high fat diet during a 12-week period. Male Sprague-Dawley rats were separated into six groups: (1) young animals on normal diet (ND, (2) young animals on a high fat diet (HFD), (3) aged animals on ND, (4) aged animals on HFD, (5) aged animals on HFD and [i]L. plantarum[/i] DR7 (10 cfu/day) and (6) aged animals receiving HFD and lovastatin. To induce ageing, all rats in group 3 to 6 were injected sub-cutaneously at 600 mg/kg/day of D-galactose daily. The administration of DR7 has reduced anxiety accompanied by enhanced memory during behavioural assessments in aged-HFD rats ([i]P[/i]<0.05). Hippocampal concentration of all three pro-inflammatory cytokines were increased during aging but reduced upon administration of both statin and DR7. Expressions of hippocampal neurotransmitters and apoptosis genes showed reduced expressions of indoleamine dioxygenase and P53 accompanied by increased expression of TPH1 in aged- HFD rats administered with DR7, indicating potential effects of DR7 along the pathways of serotonin and oxidative senescence. This study provided an insight into potentials of [i]L. plantarum[/i] DR7 as a prospective dietary strategy to improve cognitive functions during aging. This study provided an insight into potentials of [i]L. plantarum[/i] DR7 as a prospective dietary strategy to improve cognitive functions during aging.
Keywords
- Lactobacillus spp.
- aging
- brain
Healthy immune aging is in part determined by how well the sizes of naïve T cell compartments are being maintained with advancing age. Throughout adult life, replenishment largely derives from homeostatic proliferation of existing naïve and memory T cell populations. However, while the subpopulation composition of CD4 T cells is relatively stable, the CD8 T cell compartment undergoes more drastic changes with loss of naïve CD8 T cells and accumulation of effector T cells, suggesting that CD4 T cells are more resilient to resist age-associated changes. To determine the epigenetic basis for these differences in behaviors, we compared chromatin accessibility maps of CD4 and CD8 T cell subsets from young and old individuals and related the results to the expressed transcriptome. The dominant age-associated signatures resembled hallmarks of differentiation, which were more pronounced for CD8 naïve and memory than the corresponding CD4 T cell subsets, indicating that CD8 T cells are less able to keep cellular quiescence upon homeostatic proliferation. In parallel, CD8 T cells from old adults, irrespective of their differentiation state, displayed greater reduced accessibility to genes of basic cell biological function, including genes encoding ribosomal proteins. One possible mechanism is the reduced expression of the transcription factors YY1 and NRF1. Our data suggest that chromatin accessibility signatures can be identified that distinguish CD4 and CD8 T cells from old adults and that may confer the higher resilience of CD4 T cells to aging.
Keywords
- T-cell
- T-cell homeostasis
- aging
- chromatin accessibility
- epigenetics
- ribosomal proteins
Systematic understanding of immune aging on a whole-body scale is currently lacking. We characterized age-associated alterations in immune cells across multiple mouse organs using single-cell RNA and antigen receptor sequencing and flow cytometry-based validation. We defined organ-specific and common immune alterations and identified a subpopulation of age-associated granzyme K (GZMK)-expressing CD8 T (Taa) cells that are distinct from T effector memory (Tem) cells. Taa cells were highly clonal, had specific epigenetic and transcriptional signatures, developed in response to an aged host environment, and expressed markers of exhaustion and tissue homing. Activated Taa cells were the primary source of GZMK, which enhanced inflammatory functions of non-immune cells. In humans, proportions of the circulating GZMK CD8 T cell population that shares transcriptional and epigenetic signatures with mouse Taa cells increased during healthy aging. These results identify GZMK Taa cells as a potential target to address age-associated dysfunctions of the immune system.
Keywords
- Aging
- CD8 T cells
- CITE-seq
- granzyme K
- immune system
- inflammaging
- single-cell ATAC-sequencing
- single-cell BCR-sequencing
- single-cell RNA-sequencing
- single-cell TCR-sequencing
Aging is characterized by increase in reactive oxygen (ROS) and nitrogen (RNS) species, key factors of cardiac failure and disuse-induced muscle atrophy. This study focused on serum nitroproteome as a trait of longevity by adopting two complementary gel-based techniques: two-dimensional differential in gel electrophoresis (2-D DIGE) and Nitro-DIGE coupled with mass spectrometry of albumin-depleted serum of aged (A, [i]n[/i] = 15) and centenarian (C, [i]n[/i] = 15) versus young females (Y, [i]n[/i] = 15). Results indicate spots differently expressed in A and C compared to Y and spots changed in A vs. C. Nitro-DIGE revealed nitrosated protein spots in A and C compared to Y and spots changed in A vs. C only ([i]p[/i]-value < 0.01). Nitro-proteoforms of alpha-1-antitripsin (SERPINA1), alpha-1-antichimotripsin (SERPINA3), ceruloplasmin (CP), 13 proteoforms of haptoglobin (HP), and inactive glycosyltransferase 25 family member 3 (CERCAM) increased in A vs. Y and C. Conversely, nitrosation levels decreased in C vs. Y and A, for immunoglobulin light chain 1 (IGLC1), serotransferrin (TF), transthyretin (TTR), and vitamin D-binding protein (VDBP). Immunoblottings of alcohol dehydrogenase 5/S-nitrosoglutathione reductase (ADH5/GSNOR) and thioredoxin reductase 1 (TRXR1) indicated lower levels of ADH5 in A vs. Y and C, whereas TRXR1 decreased in A and C in comparison to Y. In conclusion, the study identified putative markers in C of healthy aging and high levels of ADH5/GSNOR that can sustain the denitrosylase activity, promoting longevity.
Keywords
- aging
- cardiovascular disease
- muscle atrophy
- nitrosative stress
- proteomics
Endothelial dysfunction is one of the main age-related arterial phenotypes responsible for cardiovascular disease (CVD) in older adults. This endothelial dysfunction results from decreased bioavailability of nitric oxide (NO) arising downstream of endothelial oxidative stress. In this study, we investigated the protective effect of anthocyanins and the underlying mechanism in rat thoracic aorta and human vascular endothelial cells in aging models. In vitro, cyanidin-3-rutinoside (C-3-R) and cyanidin-3-glucoside (C-3-G) inhibited the d-galactose (d-gal)-induced senescence in human endothelial cells, as indicated by reduced senescence-associated-β-galactosidase activity, p21, and p16 . Anthocyanins blocked d-gal-induced reactive oxygen species (ROS) formation and NADPH oxidase activity. Anthocyanins reversed d-gal-mediated inhibition of endothelial nitric oxide synthase (eNOS) serine phosphorylation and SIRT1 expression, recovering NO level in endothelial cells. Also, SIRT1-mediated eNOS deacetylation was shown to be involved in anthocyanin-enhanced eNOS activity. In vivo, anthocyanin-rich mulberry extract was administered to aging rats for 8 weeks. In vivo, mulberry extract alleviated endothelial senescence and oxidative stress in the aorta of aging rats. Consistently, mulberry extract also raised serum NO levels, increased phosphorylation of eNOS, increased SIRT1 expression, and reduced nitrotyrosine in aortas. The eNOS acetylation was higher in the aging group and was restored by mulberry extract treatment. Similarly, SIRT1 level associated with eNOS decreased in the aging group and was restored in aging plus mulberry group. These findings indicate that anthocyanins protect against endothelial senescence through enhanced NO bioavailability by regulating ROS formation and reducing eNOS uncoupling.
Keywords
- NO
- SIRT1
- anthocyanins
- eNOS deacetylation
- senescence
Neuromuscular dysfunction is common in old age. Damaged cytoplasmic structures aggregate with aging, especially in post-mitotic cells like motor neurons. Autophagy is a ubiquitous cell process that aids in the clearance of damaged aggregates. Accordingly, we hypothesized that autophagy is impaired in old age, contributing to neuromuscular dysfunction via an effect in motor neurons. Autophagy flux may be impaired as a result of deficits in the initiation, elongation or degradation phases. Changes in the expression levels of core proteins necessary for each of the autophagy phases were evaluated by Western blotting in the cervical spinal cord (segments C2-C6 corresponding to the phrenic motor pool) of adult male and female mice at 6-, 18-, and 24-months of age (reflecting 100%, 90% and 75% survival, respectively). There was no evidence of an effect of age on the expression of the autophagy markers Beclin-1 (Becn-1; initiation), ATG7 and ATG5/12 complex (elongation) or LC3 (elongation/degradation). Reduced p62 expression (a marker of degradation) was evident in the cervical spinal cord of adult mice at 18-months compared to 24-months. Accordingly, expression of LC3 and p62 in motor neurons was analyzed using immunofluorescence and confocal microscopy in separate animals. LC3 and p62 immunoreactivity was evident in the gray matter with minimal expression in the white matter across all age groups. A mixed linear model with animal as a random effect was used to compare relative LC3 and p62 expression in motor neurons to gray matter across age groups. Expression of both LC3 and p62 was higher in choline acetyl transferase (ChAT)-positive motor neurons (~2-3 fold vs. gray matter). Across age groups, there were differences in the relative expression of LC3 (F = 7.59, p < 0.01) and p62 (F = 8.00, p < 0.01) in cervical motor neurons. LC3 expression in motor neurons increased ~20% by 24-months of age in both male and female mice. p62 expression in motor neurons increased ~70% by 18-months compared to 6-months with no further changes by 24-months of age in male mice. p62 expression did not change across age groups in female mice, and was ~20% higher than in males. Our findings highlight important changes in autophagy pathways that likely contribute to the development of aging-related neuromuscular dysfunction in mice. At 18-months of age, increased autophagosome clearance (reduced p62 expression) appears to be a global effect not restricted to motor neurons. By 24-months of age, increased expression of LC3 and p62 indicates impaired autophagy with autophagosome accumulation in cervical motor neurons.
Keywords
- Aging
- Autophagy
- Motor neuron
- Neuromuscular dysfunction
- Spinal cord
The conditional reprogramming cell culture method was developed to facilitate growth of senescence-prone normal and neoplastic epithelial cells, and involves co-culture with irradiated fibroblasts and the addition of a small molecule Rho kinase (ROCK) inhibitor. The aim of this study was to determine whether this approach would facilitate the culture of compact low grade gliomas. We attempted to culture 4 pilocytic astrocytomas, 2 gangliogliomas, 2 myxopapillary ependymomas, 2 anaplastic gliomas, 2 difficult-to-classify low grade neuroepithelial tumors, a desmoplastic infantile ganglioglioma, and an anaplastic pleomorphic xanthoastrocytoma using a modified conditional reprogramming cell culture approach. Conditional reprogramming resulted in robust increases in growth for a majority of these tumors, with fibroblast conditioned media and ROCK inhibition both required. Switching cultures to standard serum containing media, or serum free neurosphere conditions, with or without ROCK inhibition, resulted in decreased proliferation and induction of senescence markers. ROCK inhibition and conditioned media both promoted Akt and Erk1/2 activation. Several cultures, including one derived from a NF1-associated pilocytic astrocytoma (JHH-NF1-PA1) and one from a BRAF p.V600E mutant anaplastic pleomorphic xanthoastrocytoma (JHH-PXA1), exhibited growth sufficient for preclinical testing in vitro. In addition, JHH-NF1-PA1 cells survived and migrated in larval zebrafish orthotopic xenografts, while JHH-PXA1 formed orthotopic xenografts in mice histopathologically similar to the tumor from which it was derived. These studies highlight the potential for the conditional reprogramming cell culture method to promote the growth of glial and glioneuronal tumors in vitro, in some cases enabling the establishment of long-term culture and in vivo models.
Keywords
- BRAFV600E
- Conditional reprogramming
- NF1
- Senescence
- low grade glioma
Macroautophagic/autophagic degradation of nuclear components (or nuclear autophagy) is a poorly understood area in autophagy research. We previously reported the nuclear lamina protein LMNB1 (lamin B1) as a nuclear autophagy substrate in primary human cells, stimulating the investigation of nuclear autophagy in the mammalian system. We recently reported the sirtuin protein SIRT1 as a new selective substrate of nuclear autophagy in senescence and aging. Upon senescence of primary human cells, SIRT1 degradation is mediated by a direct nuclear SIRT1-LC3 interaction, followed by nucleus-to-cytoplasm shuttling of SIRT1 and autophagosome-lysosome degradation. In vivo, SIRT1 is downregulated by lysosomes in hematopoietic and immune organs upon natural aging in mice and in aged human T cells. Our study identified another substrate of nuclear autophagy and suggests a new strategy to promote SIRT1-mediated health benefits by suppressing its autophagic degradation.
Keywords
- Aging
- SIRT1
- nuclear autophagy
- senescence
- sirtuin
Ovarian aging leads to reproductive and endocrine dysfunction, causing the disorder of multiple organs in the body and even declined quality of offspring's health. However, few studies have investigated the changes in gene expression profile in the ovarian aging process. Here, we applied integrated bioinformatics to screen, identify, and validate the critical pathogenic genes involved in ovarian aging and uncover potential molecular mechanisms. The expression profiles of GSE84078 were downloaded from the Gene Expression Omnibus (GEO) database, which included the data from ovarian samples of 10 normal C57BL/6 mice, including old (21-22 months old, ovarian failure period) and young (5-6 months old, reproductive bloom period) ovaries. First, we filtered 931 differentially expressed genes (DEGs), including 876 upregulated and 55 downregulated genes through comparison between ovarian expression data from old and young mice. Functional enrichment analysis showed that biological functions of DEGs were primarily immune response regulation, cell-cell adhesion, and phagosome pathway. The most closely related genes among DEGs ([i]Tyrobp[/i], [i]Rac2[/i], [i]Cd14[/i], [i]Zap70[/i], [i]Lcp2[/i], [i]Itgb2[/i], [i]H2-Ab1[/i], and [i]Fcer1g[/i]) were identified by constructing a protein-protein interaction (PPI) network and consequently verified using mRNA and protein quantitative detection. Finally, the immune cell infiltration in the ovarian aging process was also evaluated by applying CIBERSORT, and a correlation analysis between hub genes and immune cell type was also performed. The results suggested that plasma cells and naïve CD4 T cells may participate in ovarian aging. The hub genes were positively correlated with memory B cells, plasma cells, M1 macrophages, Th17 cells, and immature dendritic cells. In conclusion, this study indicates that screening for DEGs and pathways in ovarian aging using bioinformatic analysis could provide potential clues for researchers to unveil the molecular mechanism underlying ovarian aging. These results could be of clinical significance and provide effective molecular targets for the treatment of ovarian aging.
Keywords
- GEO database
- bioinformatics
- biomarker
- immune cell infiltration
- ovarian aging
Vascular calcification is common among aging populations and mediated by vascular smooth muscle cells (VSMCs). The endoplasmic reticulum (ER) is involved in protein folding and ER stress has been implicated in bone mineralization. The role of ER stress in VSMC-mediated calcification is less clear. Approach and Results: mRNA expression of the ER stress markers PERK (PKR (protein kinase RNA)-like ER kinase), ATF (activating transcription factor) 4, ATF6, and Grp78 was detectable in human vessels with levels of PERK decreased in calcified plaques compared to healthy vessels. Protein deposition of Grp78/Grp94 was increased in the matrix of calcified arteries. Induction of ER stress accelerated human primary VSMC-mediated calcification, elevated expression of some osteogenic markers (Runx2, Osterix, ALP, BSP, and OPG), and decreased expression of SMC markers. ER stress potentiated extracellular vesicle (EV) release via SMPD3. EVs from ER stress-treated VSMCs showed increased Grp78 levels and calcification. Electron microscopy confirmed the presence of Grp78/Grp94 in EVs. siRNA knock-down of Grp78 decreased calcification. Warfarin-induced Grp78 and ATF4 expression in rat aortas and VSMCs and increased calcification in an ER stress-dependent manner via increased EV release. ER stress induces vascular calcification by increasing release of Grp78-loaded EVs. Our results reveal a novel mechanism of action of warfarin, involving increased EV release via the PERK-ATF4 pathway, contributing to calcification. This study is the first to show that warfarin induces ER stress and to link ER stress to cargo loading of EVs.
Keywords
- aging
- arteries
- endoplasmic reticulum
- vascular calcification
- warfarin
Sestrin2 (Sesn2) is involved in the maintenance of metabolic homeostasis and aging via modulation of the 5' AMP-activated protein kinase-mammalian target of rapamycin (AMPK-mTOR) pathway. Wild-type and Sesn2 knockout (KO) mice of the 129/SvJ background were maintained in a pathogen-free authorized facility under a 12-hour dark/light cycle at 20°C-22°C and 50%-60% humidity. Mouse embryonic fibroblasts (MEFs) were prepared from 13.5-day-old embryos derived from Sesn2-KO mice mated with each other. The MEFs from Sesn2-KO mice showed enlarged and flattened morphologies and senescence-associated β-galactosidase activity, accompanied by an elevated level of reactive oxygen species. These senescence phenotypes recovered following treatment with N-acetyl-cysteine. Notably, the mRNA levels of NADPH oxidase 4 (NOX4) and transforming growth factor (TGF)-β were markedly increased in Sesn2-KO MEFs. Treatment of Sesn2-KO MEFs with the NOX inhibitor diphenyleneiodonium and the TGF-β inhibitor SB431542 restored cell growth inhibited by Sesn2-KO. Sesn2 attenuates cellular senescence via suppression of TGF-β- and NOX4-induced reactive oxygen species generation and subsequent inhibition of AMPK.
Keywords
- NOX4
- Reactive oxygen species
- Senescence
- Sestrin2
Sirtuins are class III histone deacetylase (HDAC) enzymes that target both histone and non-histone substrates. They are linked to different brain functions and the regulation of different isoforms of these enzymes is touted to be an emerging therapy for the treatment of neurodegenerative diseases (NDs), including Parkinson's disease (PD), Alzheimer's disease (AD), and amyotrophic lateral sclerosis (ALS). The level of sirtuins affects brain health as many sirtuin-regulated pathways are responsible for the progression of NDs. Certain sirtuins are also implicated in aging, which is a risk factor for many NDs. In addition to SIRT1-3, it has been suggested that the less studied sirtuins (SIRT4-7) also play critical roles in brain health. This review delineates the role of each sirtuin isoform in NDs from a disease centric perspective and provides an up-to-date overview of sirtuin modulators and their potential use as therapeutics in these diseases. Furthermore, the future perspectives for sirtuin modulator development and their therapeutic application in neurodegeneration are outlined in detail, hence providing a research direction for future studies.
Keywords
- Aging
- neurodegenerative diseases
- neuroprotective
- sirtuin
- sirtuin activators
- sirtuin inhibitors
Frailty is a geriatric syndrome represented by susceptibility to precipitating health events and reduced functional reserve. Frailty can be difficult to measure in clinical practice and research. One approach to approximate frailty is based on a deficit accumulation approach, which assesses a larger number of less specific measures such as the presence of comorbidities, physical or cognitive assessments, and lab tests, and summarizes these as a frailty index. The objective of this study was to develop such an index using the Lifestyle Interventions and Independence for Elders (LIFE) Study and evaluate the validity of the frailty measure derived based on baseline information via its association with the primary outcomes of the trial, namely major mobility disability (MMD) and persistent MMD (pMMD). Further, this study aimed to evaluate the effectiveness of the physical activity intervention among participants based on their baseline frailty score. Subjects in the LIFE Study were evaluated at baseline for demographics, clinical history, and a battery of physical and cognitive functioning assessments. In total, 75 possible deficits were scored either as present (yes/no) or based on each score's quintiles for score-based assessments. The frailty index was measured as the total sum of deficits divided by the total number of possible deficits on a continuous scale between 0 and 100 (i.e., percent of deficits present). The frailty index was further divided into quintiles for comparison. A proportional hazards model was estimated for the MMD outcome controlling for other baseline information. A data driven approach was also used to determine relevant cut-offs in the frailty index where the trial intervention appeared to be modified. Among 1635 trial participants, the mean frailty index was 30.4 ± 6.6 and normally distributed. Over 2.5 years of average follow-up, 14.6%, 16.5%, 18.6%, 22.6%, and 27.6% of participants experienced MMD in quintiles 1-5, respectively. Each 1-unit increase in the frailty index increased the hazard of MMD by 4% (2-5%), and there was a nearly 2-fold increase in MMD between the highest and lowest frailty quintiles. Using log-rank criteria, a cut-point at the median was identified. Further, iterations tested for a frailty cut-off and indicated a subgroup beyond the 85th percentile wherein the physical activity intervention appeared to be no longer be effective. This internally derived deficit accumulation frailty index was uniquely able to identify individuals at higher risk of MMD and pMMD and showed that along the spectrum of frailty, the physical activity intervention remained effective for the majority of participants.
Keywords
- LIFE Study
- deficit accumulation
- disability
- frailty
- healthy aging
- mobility
- older adults
Intron retention (IR) is the least well-understood alternative splicing type in animals, and its prevalence and function in physiological and pathological processes have long been underestimated. Cellular senescence contributes to individual aging and age-related diseases and can also serve as an important cancer prevention mechanism. Dynamic IR events have been observed in senescence models and aged tissues; however, whether and how IR impacts senescence remain unclear. Through analyzing polyA RNA-seq data from human replicative senescence models, we found IR was prevalent and dynamically regulated during senescence and IR changes negatively correlated with expression alteration of corresponding genes. We discovered that knocking down (KD) splicing factor U2AF1, which showed higher binding density to retained introns and decreased expression during senescence, led to senescence-associated phenotypes and global IR changes. Intriguingly, U2AF1-KD-induced IR changes also negatively correlated with gene expression. Furthermore, we demonstrated that U2AF1-mediated IR of specific gene (CPNE1 as an example) contributed to cellular senescence. Decreased expression of U2AF1, higher IR of CPNE1, and reduced expression of CPNE1 were also discovered in dermal fibroblasts with age. We discovered prevalent IR could fine-tune gene expression and contribute to senescence-associated phenotypes, largely extending the biological significance of IR.
Keywords
- CPNE1
- U2AF1
- intron retention
- senescence
- splicing factor
Aging results in a chronic, pro-inflammatory state which can promote and exacerbate age-associated diseases. In contrast, physical activity in older adults improves whole body health, protects against disease, and reduces inflammation, but the elderly are less active making it difficult to disentangle the effects of aging from a sedentary lifestyle. To interrogate this interaction, we analyzed peripheral blood collected at rest and post-exercise from 68 healthy younger and older donors that were either physically active aerobic exercisers or chronically sedentary. Subjects were profiled for 44 low-abundance cytokines, chemokines and growth factors in peripheral blood. At rest, we found that regular physical activity had no impact on the age-related elevation in circulating IL-18, eotaxin, GRO, IL-8, IP-10, PDGF-AA or RANTES. Similarly, there was no impact of physical activity on the age-related reduction in VEGF, EGF or IL-12 (p70). However, older exercisers had lower resting plasma fractalkine, IL-3, IL-6 and TNF-α compared to sedentary older adults. In contrast to our resting characterization, blood responses following acute exercise produced more striking difference between groups. Physically active younger and older subjects increased over 50% of the analyzed factors in their blood which resulted in both unique and overlapping exercise signatures. However, sedentary individuals, particularly the elderly, had few detectable changes in response to exercise. Overall, we show that long term physical activity has a limited effect on age-associated changes in basal cytokines and chemokines in the healthy elderly, yet physically active individuals exhibit a broader induction of factors post-exercise irrespective of age.
Keywords
- growth factors
- human aging
- inflammation
- physical activity
The knowledge about the age effects in speech acoustics is still disperse and incomplete. This study extends the analyses of the effects of age and gender on acoustics of European Portuguese (EP) oral vowels, in order to complement initial studies with limited sets of acoustic parameters, and to further investigate unclear or inconsistent results. A database of EP vowels produced by a group of 113 adults, aged between 35 and 97, was used. Duration, fundamental frequency (f0), formant frequencies (F1 to F3), and a selection of vowel space metrics (F1 and F2 range ratios, vowel articulation index [VAI] and formant centralization ratio [FCR]) were analyzed. To avoid the arguable division into age groups, the analyses considered age as a continuous variable. The most relevant age-related results included: vowel duration increase in both genders; a general tendency to formant frequencies decrease for females; changes that were consistent with vowel centralization for males, confirmed by the vowel space acoustic indexes; and no evidence of F3 decrease with age, in both genders. This study has contributed to knowledge on aging speech, providing new information for an additional language. The results corroborated that acoustic characteristics of speech change with age and present different patterns between genders.
Keywords
- Acoustic
- Aging voice
- European Portuguese
- Oral vowel
Proteostasis collapse, the diminished ability to maintain protein homeostasis, has been established as a hallmark of nematode aging. However, whether proteostasis collapse occurs in humans has remained unclear. Here, we demonstrate that proteostasis decline is intrinsic to human senescence. Using transcriptome-wide characterization of gene expression, splicing, and translation, we found a significant deterioration in the transcriptional activation of the heat shock response in stressed senescent cells. Furthermore, phosphorylated HSF1 nuclear localization and distribution were impaired in senescence. Interestingly, alternative splicing regulation was also dampened. Surprisingly, we found a decoupling between different unfolded protein response (UPR) branches in stressed senescent cells. While young cells initiated UPR-related translational and transcriptional regulatory responses, senescent cells showed enhanced translational regulation and endoplasmic reticulum (ER) stress sensing; however, they were unable to trigger UPR-related transcriptional responses. This was accompanied by diminished ATF6 nuclear localization in stressed senescent cells. Finally, we found that proteasome function was impaired following heat stress in senescent cells, and did not recover upon return to normal temperature. Together, our data unraveled a deterioration in the ability to mount dynamic stress transcriptional programs upon human senescence with broad implications on proteostasis control and connected proteostasis decline to human aging.
Keywords
- UPR
- chaperones
- heat shock response
- protein homeostasis
- senescence
For the first time in history, most of the population has a life expectancy equal or greater than 60 years. By the year 2050, it is expected that the world population in that age range will reach 2000 million, an increase of 900 million with respect to 2015, which poses new challenges for health systems. In this way, it is relevant to analyze the most common diseases associated with the aging process, namely Alzheimer´s disease, Parkinson Disease and Type II Diabetes, some of which may have a common genetic component that can be detected before manifesting, in order to delay their progress. Genetic inheritance and epigenetics are factors that could be linked in the development of these pathologies. Some researchers indicate that the [i]BDNF[/i] gene is a common factor of these diseases, and apparently some of its polymorphisms favor the progression of them. In this regard, alterations in the level of BDNF expression and secretion, due to polymorphisms, could be linked to the development and/or progression of neurodegenerative and metabolic disorders. In this review we will deepen on the different polymorphisms in the [i]BDNF[/i] gene and their possible association with age-related pathologies, to open the possibilities of potential therapeutic targets.
Keywords
- Aging
- BDNF gene
- aging-related diseases
- polymorphism
The Chinese herbal formula Heshouwu decoction (Heshouwuyin) has protective effects on testicular function in aging male rats, but the mechanism is unknown. This study investigated whether Heshouwuyin affects the testicular function of aging rats by regulating the insulin/IGF signalling pathway. Sixteen-month-old male Wistar rats in the Heshouwuyin group and the natural-aging group were orally administered Heshouwuyin granules (0.056 g/kg) or equivalent normal saline for 60 d. The testicular tissue of 12-month-old male Wistar rats was removed as a young control group ([i]n[/i] = 10). The testicular tissue and spermatogenic cells were studied. The immunofluorescence results revealed that the insulin receptor (INSR)- (0.056 ± 0.00548), insulin receptor substrate 1(IRS1)- (0.251 ± 0.031), IRS2 (0.230 ± 0.019)- and insulin-like growth factor 1 (IGF1)-positive cell rate (0.33 ± 0.04) in the aging group was higher than that in the young control group (0.116 ± 0.011, 0.401 ± 0.0256, 0.427 ± 0.031, 0.56 ± 0.031; [i]p[/i] < 0.01), and the IGF-binding protein 3 (IGFBP3)-positive cell rate (0.42 ± 0.024) was lower than that (0.06 ± 0.027) in the young group ([i]p[/i] < 0.01). The intervention of Heshouwuyin reversed the above phenomena. The qPCR and immunoblot results were consistent with those of the immunofluorescence. The same results were obtained in spermatogenic cells. Our research shows that Heshouwuyin can regulate the insulin/IGF signalling pathway to improve testicular function, and provides an experimental basis for further clinical use.
Keywords
- IGF1
- IGFBP3
- INSR
- IRS1
- IRS2
- Male reproduction
- senescence
During cellular respiration, radicals, such as superoxide, are produced, and in a large concentration, they may cause cell damage. To combat this threat, the cell employs the enzyme Cu/Zn Superoxide Dismutase (SOD1), which converts the radical superoxide into molecular oxygen and hydrogen peroxide, through redox reactions. Although this is its main function, recent studies have shown that the SOD1 has other functions that deviates from its original one including activation of nuclear gene transcription or as an RNA binding protein. This comprehensive review looks at the most important aspects of human SOD1 (hSOD1), including the structure, properties, and characteristics as well as transcriptional and post-translational modifications (PTM) that the enzyme can receive and their effects, and its many functions. We also discuss the strategies currently used to analyze it to better understand its participation in diseases linked to hSOD1 including Amyotrophic Lateral Sclerosis (ALS), cancer, and Parkinson.
Keywords
- Aging
- Cancer
- Neurodegenerative diseases
- Post-translational modifications
- Superoxide dismutase 1
Endogenous salicylic acid (SA) regulates leaf senescence, but the underlying mechanism remains largely unexplored. The exogenous application of SA to living plants is not efficient for inducing leaf senescence. By taking advantage of probenazole (PBZ)-induced biosynthesis of endogenous SA, we previously established a chemical inducible leaf senescence system that depends on SA biosynthesis and its core signaling receptor NPR1 in Arabidopsis thaliana. Here, using this system, we identified WRKY46 and WRKY6 as key components of the transcriptional machinery downstream of NPR1 signaling. Upon PBZ treatment, the wrky46 mutant exhibited significantly delayed leaf senescence. We demonstrate that NPR1 is essential for PBZ/SA-induced WRKY46 activation, whereas WRKY46 in turn enhances NPR1 expression. WRKY46 interacts with NPR1 in the nucleus, binding to the W-box of the WRKY6 promoter to induce its expression in response to SA signaling. Dysfunction of WRKY6 abolished PBZ-induced leaf senescence, while overexpression of WRKY6 was sufficient to accelerate leaf senescence even under normal growth conditions, suggesting that WRKY6 may serve as an integration node of multiple leaf senescence signaling pathways. Taken together, these findings reveal that the NPR1-WRKY46-WRKY6 signaling cascade plays a critical role in PBZ/SA-mediated leaf senescence in Arabidopsis. This article is protected by copyright. All rights reserved.
Keywords
- Leaf senescence
- NPR1
- Probenazole
- Salicylic acid
- WRKY46
- WRKY6
Perineuronal nets (PNNs) are insoluble aggregates of extracellular matrix molecules in the brain that consist of hyaluronan (HA) and chondroitin sulfate proteoglycans (CSPGs). PNNs promote the acquisition and storage of memories by stabilizing the formation of synapses in the adult brain. Although the deterioration of PNNs has been suggested to contribute to the age-dependent decline in brain function, the molecular mechanisms underlying age-related changes in PNNs remain unclear. The amount and solubility of PNN components were investigated by sequential extraction followed by a disaccharide analysis and immunoblotting. We examined the interaction between HA and aggrecan, a major HA-binding CSPG, by combining mass spectrometry and pull-down assays. The solubility and amount of HA increased in the brain with age. Among several CSPGs, the solubility of aggrecan was selectively elevated during aging. In contrast to alternations in biochemical properties, the expression of PNN components at the transcript level was not markedly changed by aging. The increased solubility of aggrecan was not due to the loss of HA-binding properties. Our results indicated that the degradation of high-molecular-mass HA induced the release of the HA-aggrecan complex from PNNs in the aged brain. The present study revealed a novel mechanism underlying the age-related deterioration of PNNs in the brain.
Keywords
- Brain aging
- Chondroitin sulfate proteoglycan
- Extracellular matrix
- Hyaluronan
- Perineuronal net
Rare perivascular mesenchymal stromal cells (MSCs) with therapeutic properties have been identified in many tissues. Their rarity necessitates extensive in vitro expansion, resulting in spontaneous differentiation, cellular senescence and apoptosis, producing therapeutic products with variable quality and decreased potency. We previously demonstrated that A83-01, a transforming growth factor beta (TGF-β) receptor inhibitor, maintained clonogenicity and promoted the potency of culture-expanded premenopausal endometrial MSCs using functional assays and whole-transcriptome sequencing. Here, we compared the effects of A83-01 on MSCs derived from postmenopausal endometrium, menstrual blood, placenta decidua-basalis, bone marrow and adipose tissue. Sushi-domain-containing-2 (SUSD2 ) and CD34 CD31 CD45 MSCs were isolated. Expanded MSCs were cultured with or without A83-01 for 7 days and assessed for MSC properties. SUSD2 identified perivascular cells in the placental decidua-basalis, and their maternal origin was validated. A83-01 promoted MSC proliferation from all sources except bone marrow and only increased SUSD2 expression and prevented apoptosis in MSCs from endometrial-derived tissues. A83-01 only improved the cloning efficiency of postmenopausal endometrial MSCs (eMSCs), and expanded adipose tissue MSCs (adMSCs) underwent significant senescence, which was mitigated by A83-01. MSCs derived from bone marrow (bmMSCs) were highly apoptotic, but A83-01 was without effect. A83-01 maintained the function and phenotype in MSCs cultured from endometrial, but not other, tissues. Our results also demonstrated that cellular SUSD2 expression directly correlates with the functional phenotype.
Keywords
- SUSD2
- adipose tissue
- apoptosis
- bone marrow
- clonogenicity
- endometrium
- menstrual fluid
- perivascular mesenchymal stromal cells
- placenta
- senescence
To evaluate the effectiveness of an evidence-based 12-week Tai Chi course designed to improve balance and physical function in a population of older veterans. Community dwelling veterans of all ages with gait and balance problems were invited to participate in the Tai Chi program. Participants completed the Berg Balance Scale (BBS), the Timed Up and Go (TUG) test, and the Falls Efficacy Scale-International (FES-I) at baseline and again at the end of the program. Descriptive statistics were used to summarize study participants' characteristics. The change from baseline to the end of the 12-week program was calculated for each of the three primary outcome variables (BBS, TUG, FES-I). Twenty-two veterans, aged 58 years and above, with perceived gait and/or balance issues were enrolled in the program with completion by 11 veterans. Veterans who completed their final assessments showed the BBS, improved significantly (p = 0.004) from baseline to the 12-week assessment. The TUG scores improved by a median of 1.3 s (p = 0.022). There was not a significant change in the FES-I. Preliminary findings provide evidence of the effectiveness of a 12-week Tai Chi program to improve functional outcomes for older veterans with mild to moderate gait and balance problems.
Keywords
- Tai Chi
- balance
- exercise
- gait
- geriatrics