COL1A1
Collagen alpha-1(I) chain precursor (Alpha-1 type I collagen)
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Periodontal ligament stem cells (PDLSCs) have many applications in the field of cytotherapy, tissue engineering, and regenerative medicine. However, the effect of age on the biological and immunological characteristics of PDLSCs remains unclear. In this study, we compared PDLSCs isolated from young and adult individuals. PDLSC proliferation was analyzed by Cell Counting Kit-8 (CCK-8) and 5-ethynyl-2'-deoxyuridine (EdU) staining, and apoptosis level was detected by Annexin V-PE/7-ADD staining. PDLSC osteogenic/adipogenic/chondrogenic differentiation potentials were assessed by alkaline phosphatase (ALP), Alizarin Red, Oil Red O, Alcian Blue staining, and related quantitative analysis. PDLSC immunosuppressive capacity was determined by EdU and Annexin V-PE/7-ADD staining. To explore its underlying mechanism, microarray, quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR), and western blot analyses were performed to detect differentially expressed genes and proteins in PDLSCs. Our results demonstrated that with aging, the proliferation and osteogenic/adipogenic/chondrogenic differentiation potential of PDLSCs decreased, whereas apoptosis of PDLSCs increased. Moreover, the immunosuppressive ability of PDLSCs decreased with aging. Compared with PDLSCs from young subjects, analysis of mRNA expression revealed an upregulation of CCND3 and RC3H2, and a downregulation of Runx2, ALP, COL1A1, PPARγ2, CXCL12, FKBP1A, FKBP1B, NCSTN, P2RX7, PPP3CB, RIPK2, SLC11A1, and TP53 in those from adult individuals. Furthermore, protein expression levels of Runx2, ALP, COL1A1, and PPARγ2 in the adult group were decreased, whereas that of CCND3 increased. Taken together, aging influences the biological and immunological characteristics of PDLSCs, and thus, it is more appropriate to utilize PDLSCs from young individuals for tissue regeneration, post-aging treatment, and allotransplantation.
Keywords
- Aging
- Immunosuppression
- Osteogenic differentiation
- Periodontal ligament stem cells
- Peripheral blood mononuclear cells
- Tissue engineering
We investigate the effects of RT on the mechanical function, gene, and protein expression of key factors involved in bone remodeling during aging. Male rats of 3 and 21 months of age were randomly allocated into four groups (8 per group): young sedentary (YS), young trained (YT), old sedentary (OS), and old trained (OT). RT was performed three times per week (12 weeks). Bone tenacity and stiffness were measured by biomechanical tests and mRNA levels of COL1A1, MEPE, SOST, OPG, BMP-2, PPAR-y, MMP-2-9-13, and TIMP-1 were evaluated by quantitative PCR. COL1A1 protein and MMP-2 activity were detected by western blotting and zymography assays. Aging increased stiffness, while BMP-2, OPG, COL1A1 and MMP-2 mRNA levels reduced (OS vs YS; p ≤ 0.05). RT increased the tenacity of the femur and reduced PPAR-γ regardless of age (YT vs. YS; OT vs. OS; p ≤ 0.05). RT downregulated SOST mRNA levels only in the OT group (vs. OS group, p ≤ 0.05). RT mitigated the age-associated increase in MMP-9 mRNA levels (p ≤ 0.05). In young animals, upregulation in MEPE, MMP-13, TIMP-1 were observed after RT, as well an increase in COL1A1 protein and MMP-2 activity (p ≤ 0.05). RT improved bone tenacity independent of aging, which is relevant for mechanical function, while, at protein levels, RT upregulated MMP-2 activity and collagen 1 only in young rats. This study highlights the importance of exercise on bone health and identifies specific molecular changes in response to RT. Our findings provide insights into the mechanisms involved in age-related changes.
MeSH Terms
- Age Factors
- Aging
- Animals
- Bone Remodeling
- Gene Expression Regulation
- Male
- Physical Conditioning, Animal
- RNA, Messenger
- Random Allocation
- Rats
- Rats, Wistar
- Resistance Training
Keywords
- Aging
- Bone homeostasis
- Function
- Resistance training
Chronic wounds are a major, often underestimated, health problem for the elderly. Standard wound care products are not usually manufactured to meet the increased demand of nutrients by skin cells in order to regenerate new tissue and accelerate healing. This work was therefore undertaken to establish whether wound healing could be accelerated by nutritional supplementation with a specific mixture tailored to human need of essential amino acids (EAAs) without topical medication. To this end, using a skin full-thickness excisional model in aged rats, we compared the closure dynamics of undressing wounds in animals fed an EAAs-enriched diet or standard diet. We assessed the degree of fibrosis and inflammation, as well as relevant signaling molecules such as COL1A1, iNOS and TGFβ1. The results showed wound healing was accelerated in EAAs-fed rats, which was accompanied by reduced inflammation and changes in TGFβ1 and COL1A1 expression. Collectively, our findings indicate that dietary supplementation with balanced EAAs diet could serve as a strategy to accelerate wound healing without inducing fibrosis and could therefore be a simple but pivotal therapeutic approach in human also.
MeSH Terms
- Aging
- Amino Acids, Essential
- Animals
- Biomarkers
- Collagen
- Collagen Type I
- Diet
- Dietary Supplements
- Drinking Behavior
- Eating
- Immunohistochemistry
- Male
- Nitric Oxide Synthase Type II
- Rats, Sprague-Dawley
- Transforming Growth Factor beta1
- Wound Healing
Keywords
- Aging
- Amino acids
- Rat
- Skin
- Wound healing
Pulmonary fibrosis is a severe condition with no cure and limited therapeutic options. A better understanding of its pathophysiology is needed. Recent studies have suggested that pulmonary fibrosis may be driven by accelerated aging-related mechanisms. Sirtuins (SIRTs), particularly SIRT1, SIRT3, and SIRT6, are well-known mediators of aging; however, limited data exist on the contribution of sirtuins to lung fibrosis. We assessed the mRNA and protein levels of all seven known sirtuins in primary lung fibroblasts from patients with idiopathic pulmonary fibrosis (IPF) and systemic sclerosis-associated interstitial lung disease (SSc-ILD) in comparison with lung fibroblasts from healthy controls. These unbiased tests revealed a tendency for all sirtuins to be expressed at lower levels in fibroblasts from patients compared with controls, but the greatest decrease was observed with SIRT7. Similarly, SIRT7 was decreased in lung tissues of bleomycin-challenged mice. Inhibition of SIRT7 with siRNA in cultured lung fibroblasts resulted in an increase in collagen and α-smooth muscle actin (α-SMA). Reciprocally, overexpression of SIRT7 resulted in lower basal and TGF-β-induced levels of COL1A1, COL1A2, COL3A1, and α-SMA mRNAs, as well as collagen and α-SMA proteins. Induced changes in SIRT7 had no effect on endogenous TGF-β mRNA levels or latent TGF-β activation, but overexpression of SIRT7 reduced the levels of Smad3 mRNA and protein. In conclusion, the decline in SIRT7 in lung fibroblasts has a profibrotic effect, which is mediated by changes in Smad3 levels.
MeSH Terms
- Actins
- Adult
- Animals
- Cell Nucleus
- Cells, Cultured
- Collagen
- Dermis
- Female
- Fibroblasts
- Gene Silencing
- Humans
- Idiopathic Pulmonary Fibrosis
- Immunohistochemistry
- Infant, Newborn
- Lung
- Mice, Inbred C57BL
- Phenotype
- RNA, Messenger
- Sirtuins
- Smad3 Protein
- Subcellular Fractions
- Transforming Growth Factor beta
Keywords
- SIRT7
- aging
- idiopathic pulmonary fibrosis
- pulmonary fibrosis
- systemic sclerosis
The transcription factor scleraxis is required for tendon development and is upregulated during embryonic stem cell (ESC) differentiation into tenocytes. However, its role beyond early embryonic development is not defined. We utilized a short hairpin RNA to knock down scleraxis expression in ESCs and adult and fetal tenocytes. No effect on growth or morphology was observed in two-dimensional cultures. However, scleraxis knockdown in fetal tenocytes significantly reduced COL1A1, COMP, and SOX9 gene expression. Scleraxis knockdown in adult tenocytes had no effect on the expression of these genes. Strikingly, differentiating ESCs and fetal tenocytes without scleraxis failed to reorganize a three-dimensional (3D) matrix and generate artificial tendons. This was associated with a significantly reduced survival. In contrast, there was no effect on the survival and remodeling capacity of adult tenocytes following scleraxis knockdown. Overexpression of scleraxis in fetal tenocytes rescued gene expression, cell survival in 3D, and subsequent matrix contraction. Together, these results demonstrate that scleraxis is not only essential for ESC differentiation into tenocytes but that it also has an active role in maintaining fetal tenocytes, which is then redundant in adult tenocytes.
MeSH Terms
- Aging
- Animals
- Basic Helix-Loop-Helix Transcription Factors
- Cartilage Oligomeric Matrix Protein
- Cell Differentiation
- Cell Proliferation
- Cell Survival
- Cells, Cultured
- Collagen Type I
- DNA, Complementary
- Embryonic Stem Cells
- Fetus
- Gels
- Gene Expression Regulation
- Gene Knockdown Techniques
- Horses
- RNA, Small Interfering
- SOX9 Transcription Factor
- Tendons
- Tenocytes
Keywords
- embryonic stem cells
- scleraxis
- tendon
Skin aging is a process of structural and compositional remodeling that can be manifested as wrinkling and sagging. Remarkably, the dermis plays a dominant role in the process of skin aging. Recent studies suggest that microRNAs (miRNAs) may play a role in the regulation of gene expression in organism aging. However, studies about age-related miRNAs in human skin remain limited. To obtain an overall view of miRNAs expression in human aged dermis by comparison of dermis samples between young and elderly, construct the miRNA-gene-network and reveal the pivotal miRNAs in the regulatory network. Human dermis tissue was obtained from 12 donors, including 6 of young group and 6 of elderly one. The miRNA microarray and data analysis were performed. Target genes of differentially expressed miRNAs were predicted, followed by a gene ontology and pathway enrichment analysis. A miRNA-gene-network was then constructed, and the pivotal miRNAs in the network was revealed. Primary human dermal fibroblasts (HDFs) were isolated, and the cellular senescence was induced by serial passaging. Alteration in the expression of miRNAs between young and senescent fibroblasts was evaluated by real-time quantitative RT-PCR. MiR-34b-5p mimics were transfected into primary HDFs. Subsequent cell cycle analysis was performed and expression level of COL1A1, elastin and MMP-1 were evaluated. The expression of a total of 40 miRNAs (25 upregulated and 15 downregulated) was found to be significantly altered in aged dermis compared with young dermis. Real-time quantitative PCR results confirmed the differential expression of miR-34 family and miR-29 family between young and aged dermis. A computational approach demonstrated that predicted target genes of the miRNA profile were found to be mainly involved in processes including cell adhesion, collagen synthesis, positive or negative regulation of transcription, as well as pathways such as insulin signaling pathway, ErbB (Erythroblastic Leukemia Viral Oncogene Homolog) signaling pathway and Focal adhesion pathway. The miRNA-Gene-Network revealed that miR-34 family, miR-29 family and miR-424 may play a dominant role in the regulatory network. A similar miRNA alteration was observed in senescent fibroblasts in vitro, and the age-related miRNA profile may interact with p16 pathway to regulate the fibroblasts' senescence. Additionally, transfection of miR-34b-5p mimics induced cell cycle arrest in HDFs, decreased the expression of both COL1A1 and elastin and increased MMP-1 expression. The miR-34 family and miR-29 family expressed differentially in young and aged dermis. MiR-34 in HDFs modulated the cell function and expression of MMP-1, COL1A1 and elastin. The miRNAs may play critical roles in affecting dermis aging.
MeSH Terms
- Age Factors
- Aged
- Cellular Senescence
- Child
- Dermis
- Down-Regulation
- Fibroblasts
- Gene Expression Profiling
- Gene Regulatory Networks
- Humans
- MicroRNAs
- Middle Aged
- Reverse Transcriptase Polymerase Chain Reaction
- Signal Transduction
- Skin Aging
- Up-Regulation
Keywords
- Dermis
- Human
- MicroRNA
- Skin aging
- microRNA-29
- microRNA-34
Deciduous and permanent human teeth represent an excellent model system to study aging of stromal populations. Aging is tightly connected to self-renewal and proliferation and thus, mapping potential molecular differences in these characteristics between populations constitutes an important task. Using specifically designed microarray panels, Real-Time Quantitative Polymerase Chain Reaction (RT q-PCR), Western blot, immunohistochemistry and siRNA-mediated knock down experiments, we have detected a number of molecules that were differentially expressed in dental pulp from deciduous and permanent teeth extracted from young children and adults, respectively. Among the differentially regulated genes, high-mobility group AT-hook 2 (HMGA2), a stem cell-associated marker, stood out as a remarkable example with a robust expression in deciduous pulp cells. siRNA-mediated knock down of HMGA2 expression in cultured deciduous pulp cells caused a down-regulated expression of the pluripotency marker NANOG. This finding indicates that HMGA2 is a pulpal stem cell regulatory factor. In addition to this, we discovered that several proliferation-related genes, including CDC2A and CDK4, were up-regulated in deciduous pulp cells, while matrix genes COL1A1, fibronectin and several signaling molecules, such as VEGF, FGFr-1 and IGFr-1 were up-regulated in the pulp cells from permanent teeth. Taken together, our data suggest that deciduous pulp cells are more robust in self- renewal and proliferation, whereas adult dental pulp cells are more capable of signaling and matrix synthesis.
MeSH Terms
- Adult
- Aging
- CDC2 Protein Kinase
- Cell Proliferation
- Cells, Cultured
- Child
- Child, Preschool
- Cyclin-Dependent Kinase 4
- Cyclin-Dependent Kinases
- Dental Pulp
- Down-Regulation
- HMGA2 Protein
- Homeodomain Proteins
- Humans
- Middle Aged
- Nanog Homeobox Protein
- Oligonucleotide Array Sequence Analysis
- RNA Interference
- RNA, Small Interfering
- Stromal Cells
- Tooth, Deciduous
- Young Adult
Aging and obesity contribute to the initiation and progression of osteoarthritis with little information on their relation to gene expression in joint tissues, particularly the meniscus. Here, we test the hypothesis that patient age and body mass index (BMI) correlate with the expression of osteoarthritis- and obesity-related gene signatures in the meniscus. Meniscus was obtained from patients (N=68) undergoing arthroscopic partial meniscectomy. The mRNA expression of 24 osteoarthritis-related and 4 obesity-related genes in meniscus was assessed by quantitative real-time PCR. The relationship between gene expression and patient age and BMI was analyzed using Spearman's rank-order correlation. Hierarchical cluster dendrogram and heat map were generated to study inter-gene associations. Age was negatively correlated (P<0.05) with the expression of MMP-1 (r=-0.447), NFκB2 (r=-0.361), NFκBIA (r=-0.312), IκBA (r=-0.308), IL-8 (r=-0.305), ADAMTS-4 (r=-0.294), APLN (apelin) (r=-0.250) and IL-6 (r=-0.244). Similarly, BMI was negatively correlated with the expression of APLN (r=-0.328), ACAN (r=-0.268) and MMP-1 (r=-0.261). After adjusting for the correlation between age and BMI (r=0.310; P=0.008), the only independent effect of BMI on gene expression was for APLN (r=-0.272). However, age had an independent effect on the expression on ADAMTS-4 (r=-0.253), MMP-1 (r=-0.399), IL-8 (r=-0.327), COL1A1 (r=-0.287), NFκBIA (r=-0.278), NFκB2 (r=-0.312) and IκBA (r=-0.299). The gene correlation analysis identified four clusters of potentially relevant genes: transcription factors, matrix-degrading enzymes, cytokines and chemokines, and obesity genes. Age and BMI were negatively correlated with several osteoarthritis- and obesity-related genes. Although the bulk of these changes appeared to be driven by age, expression of APLN was related to BMI. Inter-gene correlation analysis implicated a common role for strongly correlated genes. Although age-related variations in gene expression appear to be more relevant than obesity-related differences for the role of the meniscus in osteoarthritis development, further investigation into the role of APLN in meniscus and joint health is warranted.
MeSH Terms
- ADAM Proteins
- ADAMTS4 Protein
- Adolescent
- Adult
- Aged
- Aging
- Apelin
- Body Mass Index
- Cartilage, Articular
- Female
- Gene Expression Profiling
- Gene Expression Regulation
- Humans
- I-kappa B Proteins
- Intercellular Signaling Peptides and Proteins
- Interleukin-8
- Male
- Matrix Metalloproteinase 1
- Menisci, Tibial
- Middle Aged
- NF-KappaB Inhibitor alpha
- NF-kappa B p52 Subunit
- Obesity
- Osteoarthritis
- Procollagen N-Endopeptidase
- Protein Array Analysis
- Real-Time Polymerase Chain Reaction
- Tibial Meniscus Injuries
- United States