CFTR
Cystic fibrosis transmembrane conductance regulator (CFTR) (ATP-binding cassette sub-family C member 7) (Channel conductance-controlling ATPase) (EC 5.6.1.6) (cAMP-dependent chloride channel) [ABCC7]
Publications[править]
Cystic fibrosis (CF), a severe life-limiting disease, is associated with multi-organ pathologies that contribute to a reduced exercise capacity. At present, the impact of, and interaction between, disease progression and other age-related physiological changes in CF on exercise capacity from child- to adult-hood is poorly understood. Indeed, the influences of disease progression and aging are inherently linked, leading to increasingly complex interactions. Thus, when interpreting age-related differences in exercise tolerance and devising exercise-based therapies for those with CF, it is critical to consider age-specific factors. Specifically, changes in lung function, chronic airway colonization by increasingly pathogenic and drug-resistant bacteria, the frequency and severity of pulmonary exacerbations, endocrine comorbidities, nutrition-related factors, and CFTR (cystic fibrosis transmembrane conductance regulator protein) modulator therapy, duration, and age of onset are important to consider. Accounting for how these factors ultimately influence the ability to exercise is central to understanding exercise impairments in individuals with CF, especially as the expected lifespan with CF continues to increase with advancements in therapies. Further studies are required that account for these factors and the changing landscape of CF in order to better understand [i]how[/i] the evolution of CF disease impacts exercise (in)tolerance across the lifespan and thereby identify appropriate intervention targets and strategies.
Keywords
- aging
- cystic fibrosis
- exercise capacity
- exercise prescription
- pediatric
Chronic Obstructive Pulmonary Disease (COPD) is a complex disease resulting in respiratory failure and represents the third leading cause of global death. The two classical phenotypes of COPD are chronic bronchitis and emphysema. Owing to similarities between chronic bronchitis and the autosomal-recessive disease Cystic Fibrosis (CF), a significant body of research addresses the hypothesis that dysfunctional CF Transmembrane Conductance Regulator (CFTR) is implicated in the pathogenesis of COPD. Much less attention has been given to emphysema in this context, despite similarities between the two diseases. These include early-onset cellular senescence, similar comorbidities, and the finding that CF patients develop emphysema as they age. To determine a potential role for CFTR dysfunction in the development of emphysema, Cftr (Wild-type; WT), Cftr (heterozygous), and Cftr (knock-out; KO) mice were aged or exposed to cigarette smoke and analyzed for airspace enlargement. Aged knockout mice demonstrated increased alveolar size compared to age-matched wild-type and heterozygous mice. Furthermore, both heterozygous and knockout mice developed enlarged alveoli compared to their wild-type counterparts following chronic smoke exposure. Taken into consideration with previous findings that cigarette smoke leads to reduced CFTR function, our findings suggest that decreased CFTR expression sensitizes the lung to the effects of cigarette smoke. These findings may caution normally asymptomatic CF carriers against exposure to cigarette smoke; as well as highlight emphysema as a future challenge for CF patients as they continue to live longer. More broadly, our data, along with clinical findings, may implicate CFTR dysfunction in a pathology resembling accelerated aging.
MeSH Terms
- Aging
- Animals
- Cystic Fibrosis Transmembrane Conductance Regulator
- Gene Expression
- Inhalation Exposure
- Mice
- Mice, Knockout
- Pulmonary Emphysema
- Tobacco Smoke Pollution
Keywords
- Aging
- CFTR
- Emphysema
- Smoking
Pulmonary disease is the main cause of the morbidity and mortality of patients affected by cystic fibrosis (CF). The lung pathology is dominated by excessive recruitment of neutrophils followed by an exaggerated inflammatory process that has also been reported to occur in the absence of apparent pathogenic infections. Airway surface dehydration and mucus accumulation are the driving forces of this process. The continuous release of reactive oxygen species and proteases by neutrophils contributes to tissue damage, which eventually leads to respiratory insufficiency. CF has been considered a paediatric problem for several decades. Nevertheless, during the last 40 years, therapeutic options for CF have been greatly improved, turning CF into a chronic disease and extending the life expectancy of patients. Unfortunately, chronic inflammatory processes, which are characterized by a substantial release of cytokines and chemokines, along with ROS and proteases, can accelerate cellular senescence, leading to further complications in adulthood. The alterations and mechanisms downstream of CFTR functional defects that can stimulate cellular senescence remain unclear. However, while there are correlative data suggesting that cellular senescence may be implicated in CF, a causal or consequential relationship between cellular senescence and CF is still far from being established. Senescence can be both beneficial and detrimental. Senescence may suppress bacterial infections and cooperate with tissue repair. Additionally, it may act as an effective anticancer mechanism. However, it may also promote a pro-inflammatory environment, thereby damaging tissues and leading to chronic age-related diseases. In this review, we present the most current knowledge on cellular senescence and contextualize its possible involvement in CF.
MeSH Terms
- Cellular Senescence
- Cystic Fibrosis
- Cystic Fibrosis Transmembrane Conductance Regulator
- Humans
Keywords
- Cellular senescence
- Cystic fibrosis
- SASP
Cystic fibrosis (CF) and Wilson disease (WD) are two monogenetic, recessively inherited lethal pathologies that are caused by ionic disequilibria. CF results from loss-of-function mutations in CF transmembrane conductance regulator (CFTR), a channel that conducts chloride across epithelial cell membranes, while WD is due to a deficiency of ATPase copper transporting beta (ATP7B), a plasma membrane protein that pumps out copper from cells. Recent evidence suggests that both diseases are linked to perturbations in autophagy. CFTR deficiency causes an inhibition of autophagic flux, thus locking respiratory epithelial cells in a pro-inflammatory state and subverting the bactericidal function of macrophages. WD is linked to an increase in autophagy, which, however, is insufficient to mitigate the cytotoxicity of copper. Pharmacological induction of autophagy may delay disease progression, as indicated by preclinical evidence (for CF and WD) and results from clinical trials, in particular in CF patients with the most frequent [i]CTRT[/i] mutation ([i]CFTRdel506[/i]). Thus, CF and WD exemplify pathologies in which insufficient autophagy plays a major role in determining the chronology of disease progression, much like the pace of 'normal' aging that is dictated by disabled autophagy as well.
MeSH Terms
- Age Factors
- Aging
- Animals
- Autophagy
- Cellular Senescence
- Copper-Transporting ATPases
- Cystic Fibrosis
- Cystic Fibrosis Transmembrane Conductance Regulator
- Disease Progression
- Genetic Predisposition to Disease
- Hepatolenticular Degeneration
- Humans
- Mutation
- Phenotype
Keywords
- Beclin 1
- aging
- heavy metals
- hepatosteatosis
- ion channels
Normal cystic fibrosis (CF) transmembrane regulator (CFTR) protein has multiple functions in health and disease. Many mutations in the CFTR gene produce abnormal or absent protein. CFTR protein dysfunction underlies the classic CF phenotype of progressive pulmonary and GI pathology but may underlie diseases not usually associated with CF. This review highlights selected extrapulmonary disease that may be associated with abnormal CFTR. Increasing survival in CF is associated with increasing incidence of diseases associated with aging. CFTR dysfunction in older individuals may have novel effects on glucose metabolism, control of insulin release, regulation of circadian rhythm, and cancer cell pathophysiology. In individuals who have cancers with acquired CFTR suppression, their tumors may more likely exhibit rapid expansion, epithelial-to-mesenchymal transformation, abnormally reduced apoptosis, and increased metastatic potential. The new modulators of CFTR protein synthesis could facilitate the additional exploration needed to better understand the unfolding clinical biology of CFTR in human disease, even as they revolutionize treatment of patients with CF.
MeSH Terms
- Aging
- Circadian Rhythm
- Cystic Fibrosis
- Cystic Fibrosis Transmembrane Conductance Regulator
- Glucose
- Humans
- Mutation
- Neoplasms
Keywords
- cancer
- circadian rhythm
- cystic fibrosis transmembrane regulator
- hypoglycemia
- sleep
Cystic fibrosis (CF) is a genetic disease with pulmonary involvement being predominant and often leading to respiratory failure and premature death. Non-pulmonary complications related to CF transmembrane conductance regulator (CFTR) defect are numerous and account for significant morbidity (exocrine pancreatic insufficiency, diabetes, CF-related liver disease, chronic sinusitis, osteoporosis). Improvement in patients' care led to a continuous increase in life expectancy, with a subsequent increase in the number of adult CF patients worldwide. Increased life expectancy comes with increased prevalence of CF-related comorbidities, but also with new emerging complications directly related to ageing (chronic kidney disease, cardiovascular risk factors, cancers). CFTR modulators might also contribute to modify the face of CF epidemiology and prognosis. Ageing with CF has become a challenge for CF patients and caregivers. This review summarizes classic and emerging comorbidities in the context of current growth and ageing of the CF population. It also addresses potential roles of CFTR modulators.
MeSH Terms
- Adult
- Aging
- Comorbidity
- Cystic Fibrosis
- Cystic Fibrosis Transmembrane Conductance Regulator
- Humans
- Life Expectancy
Keywords
- Cancer
- Chronic kidney disease
- Cystic fibrosis
- Diabetes
- Diabète
- Insuffisance rénale chronique
- Mucoviscidose
- Osteoporosis
- Ostéoporose
Inflammation in the lung is the body's natural response to injury. It acts to remove harmful stimuli such as pathogens, irritants, and damaged cells and initiate the healing process. Acute and chronic pulmonary inflammation are seen in different respiratory diseases such as; acute respiratory distress syndrome, chronic obstructive pulmonary disease (COPD), asthma, and cystic fibrosis (CF). In this review, we found that inflammatory response in COPD is determined by the activation of epithelial cells and macrophages in the respiratory tract. Epithelial cells and macrophages discharge transforming growth factor-β (TGF-β), which trigger fibroblast proliferation and tissue remodeling. Asthma leads to airway hyper-responsiveness, obstruction, mucus hyper-production, and airway-wall remodeling. Cytokines, allergens, chemokines, and infectious agents are the main stimuli that activate signaling pathways in epithelial cells in asthma. Mutation of the CF transmembrane conductance regulator (CFTR) gene results in CF. Mutations in CFTR influence the lung epithelial innate immune function that leads to exaggerated and ineffective airway inflammation that fails to abolish pulmonary pathogens. We present mechanistic computational models (based on ordinary differential equations, partial differential equations and agent-based models) that have been applied in studying the complex physiological and pathological mechanisms of chronic inflammation in different airway diseases. The scope of the present review is to explore the inflammatory mechanism in airway diseases and highlight the influence of aging on airways' inflammation mechanism. The main goal of this review is to encourage research collaborations between experimentalist and modelers to promote our understanding of the physiological and pathological mechanisms that control inflammation in different airway diseases.
MeSH Terms
- Aging
- Animals
- Humans
- Inflammation
- Lung
- Models, Biological
- Respiratory Tract Diseases
Keywords
- Airway disease
- Computational modeling
- Inflammaging
- Inflammation
Cystic fibrosis (CF) is the most common inherited disease in Caucasians, affecting around 10,000 individuals in the UK today. Prognosis has improved considerably over recent decades with ongoing improvements in treatment and care. Providing up-to-date survival predictions is important for patients, clinicians and health services planning. Flexible parametric survival modelling of UK CF Registry data from 2011 to 2015, capturing 602 deaths in 10,428 individuals. Survival curves were estimated from birth; conditional on reaching older ages; and projected under different assumptions concerning future mortality trends, using baseline characteristics of sex, CFTR genotype (zero, one, two copies of F508del) and age at diagnosis. Male sex was associated with better survival, as was older age at diagnosis, but only in F508del non-homozygotes. Survival did not differ by genotype among individuals diagnosed at birth. Median survival ages at birth in F508del homozygotes were 46years (males) and 41years (females), and similar in non-homozygotes diagnosed at birth. F508del heterozygotes diagnosed aged 5 had median survival ages of 57 (males) and 51 (females). Conditional on survival to 30, median survival age rises to 52 (males) and 49 (females) in homozygotes. Mortality rates decreased annually by 2% during 2006-2015. Future improvements at this rate suggest median survival ages for F508del homozygous babies of 65 (males) and 56 (females). Over half of babies born today, and of individuals aged 30 and above today, can expect to survive into at least their fifth decade. Evidence before this study We searched PubMed with terms "(cystic fibrosis survival) and (projection OR model OR registry OR United Kingdom OR UK)" to identify relevant studies on survival estimates for individuals with cystic fibrosis (CF). We also considered the most recent annual report from the UK Cystic Fibrosis Registry (Cystic Fibrosis Trust, 2016), a review by Buzzetti and colleagues (2009), the chapter on Epidemiology of Cystic Fibrosis by MacNeill (2016), the study of MacKenzie and colleagues (2014), and references therein. There have been many studies of factors associated with survival in CF; most have focused on identifying risk factors, and only a few have presented estimated survival curves, which are the focus of this work. The most recent study of survival in the UK is by Dodge and colleagues (2007), who used data obtained from CF clinics and the national death register, and gave an estimate of survival for babies born in 2003. We found no previous studies that have obtained detailed information on survival using UK Cystic Fibrosis Registry data. Jackson and colleagues obtained survival estimates for the US and Ireland using registry data (Jackson et al., 2011). MacKenzie and colleagues used US Cystic Fibrosis Foundation Patient Registry data from 2000 to 2010 to project survival for children born and diagnosed with CF in 2010, accounting for sex, genotype and age at diagnosis (MacKenzie et al., 2014). Previous studies on estimated survival in CF have become out of date or have not accounted for the full range of patient characteristics available at birth. Few have presented conditional survival estimates (Dodge et al., 2007). Added value of this study This is the first study to yield detailed survival statistics using the UK Cystic Fibrosis Registry, which is one of the largest national CF registries outside of the US and has almost complete coverage of the UK CF population. The primary goal was to leverage the long-term follow-up of the nearly complete UK CF population available in the Registry for the purposes of producing accurate, precise predictions in the modern era of CF care. Estimates are presented from birth and conditional on survival to older ages. These are the first conditional estimates in CF to also account for genotype, sex and age at diagnosis, which were each included in the modelling using a flexible approach. Projections are also provided under different scenarios based on downward trends in mortality rates. Our use of flexible parametric survival models is novel in this field, and our approach could be used to provide modern survival statistics for other chronic diseases and disorders. Implications of all the available evidence Our estimates of future survival in CF under a range of different scenarios are based on data on nearly all individuals living with the disease in the UK in recent times, reflective of a modern era of care, and are most appropriate for the families of babies being born in the present day with CF. Conditional estimates inform patients who have already reached an older age, and their clinicians. Over half of babies born today, and of individuals aged 30years and above alive today, can expect to survive into their fifth decade. Insights based on our survival projections can be used to inform future needs in CF health care provision.
MeSH Terms
- Adolescent
- Adult
- Aged
- Child
- Child, Preschool
- Cystic Fibrosis
- Cystic Fibrosis Transmembrane Conductance Regulator
- Female
- Humans
- Infant
- Life Expectancy
- Longitudinal Studies
- Male
- Middle Aged
- Registries
- Survival Analysis
- Survival Rate
- United Kingdom
- Young Adult
Keywords
- CFTR genotype
- Cystic fibrosis
- Flexible parametric survival model
- Longitudinal study
- Patient registry
- Survival
Cystic fibrosis (CF) is a monogenic autosomal recessive disorder affecting around 75,000 individuals worldwide. It is a multi-system disease but the main morbidity and mortality is caused by chronic lung disease. Due to newborn screening, a multidisciplinary approach to care and intensive symptomatic treatment, the prognosis has dramatically improved over the last decades and there are currently more adults than children in many countries. However, CF is still a very severe disease with a current median age of life expectancy in the fourth decade of life. The disease is caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene which encodes the CFTR protein, a protein kinase A-activated ATP-gated anion channel that regulates the transport of electrolytes such as chloride and bicarbonate. More than 2000 mutations have been reported, although not all of these have functional consequences. An enormous research effort and progress has been made in understanding the consequences of these mutations on the CFTR protein structure and function, and this has led to the approval of two new drug therapies that are able to bind to defective CFTR proteins and partially restore their function. They are mutation-specific therapies and available at present for specific mutations only. They are the first personalized medicine for CF with a possible disease-modifying effect. A pipeline of other compounds is under development with different mechanisms of action. It is foreseeable that new combinations of compounds will further improve the correction of CFTR function. Other strategies including premature stop codon read-through drugs, antisense oligonucleotides that correct the basic defect at the mRNA level or gene editing to restore the defective gene as well as gene therapy approaches are all in the pipeline. All these strategies are needed to develop disease-modifying therapies for all patients with CF.
MeSH Terms
- Adolescent
- Adult
- Aminophenols
- Child
- Child, Preschool
- Chloride Channel Agonists
- Cystic Fibrosis
- Cystic Fibrosis Transmembrane Conductance Regulator
- DNA Mutational Analysis
- Exocrine Pancreatic Insufficiency
- Genetic Therapy
- Humans
- Infant
- Infant, Newborn
- Interdisciplinary Communication
- Intersectoral Collaboration
- Life Expectancy
- Phenotype
- Prognosis
- Quinolones
- Young Adult
The exocrine pancreatic insufficiency affects more than 80% of cystic fibrosis (CF) infants. Pancreatic insufficiency is diagnosed by low levels of fecal elastase. An optimal caloric intake, a pancreatic enzyme treatment are the keys to maintain a good nutritional status. The fat soluble vitamins supplementation will be associated with pancreatic enzymes treatment and will be adapted to plasma levels. Iron and oligo-element deficiency such as zinc is common. The pancreatic enzymes function is not optimal in the proximal bowel: the intraluminal intestinal pH is low because of the absence of bicarbonate release by the pancreas. The use of proton pump inhibitors may improve the functionality of pancreatic enzymes treatment. New therapies such as ivacaftor in patients with a G551D mutation allows a weight gain in particular by restoring intestinal pH similar to controls. Lengthening of the life expectancy of patients with CF is accompanied by the emergence new aspects of the disease, especially diabetes, favored by pancreatic cystic fibrosis resulting in an anatomical destruction of pancreatic islets. Currently, diabetes affects a third of the patients after 20 years, and half after 30 years. Cystic fibrosis-related diabetes is a major factor of morbidity-mortality in all stages of the disease and is characterized by a preclinical phase of glucose intolerance particularly long reaching up to 10 years. Its pathophysiology combines a lack of insulin secretion, an insulin resistance secondary to chronic infection, and a decrease in the production of the GIP and GLP-1. The insulin secretion depending on the channel chlorine (Cystic Fibrosis Transmembrane conductance Regulator [[[CFTR]]]) activity at the membrane surface of insulin cell is reduced prior to the occurrence of pancreatic histological lesions. At the stage of diabetes, obtaining a normoglycemia by insulin treatment began very early allows to slow the decline of lung function and nutritional status. Given the silent phase of diabetes, screening it is recommended by the realization of an annual OGTT from 10 years of age, or before in severe forms of CF. New treatments of CF able to target CFTR showed their efficacy in slowing the decline of lung function, and could also contribute to slow or prevent the onset of diabetes.
MeSH Terms
- Adolescent
- Adult
- Child
- Child, Preschool
- Cystic Fibrosis
- Diabetes Mellitus
- Energy Intake
- Exocrine Pancreatic Insufficiency
- Glucose Tolerance Test
- Humans
- Infant
- Islets of Langerhans
- Life Expectancy
- Pancreas, Exocrine
- Pancreatic Extracts
- Proton Pump Inhibitors
- Young Adult
Protein modeling and molecular dynamics hold a unique toolset to aide in the characterization of clinical variants that may result in disease. Not only do these techniques offer the ability to study under characterized proteins, but they do this with the speed that is needed for time-sensitive clinical cases. In this paper we retrospectively study a clinical variant in the XIAP protein, C203Y, while addressing additional variants seen in patients with similar gastrointestinal phenotypes as the C203Y mutation. In agreement with the clinical tests performed on the C203Y patient, protein modeling and molecular dynamics suggest that direct interactions with RIPK2 and Caspase3 are altered by the C203Y mutation and subsequent loss of Zn coordination in the second BIR domain of XIAP. Interestingly, the variant does not appear to alter interactions with SMAC, resulting in further damage to the caspase and NOD2 pathways. To expand the computational strategy designed when studying XIAP, we have applied the molecular modeling tools to a list of 140 variants seen in CFTR associated with cystic fibrosis, and a list of undiagnosed variants in 17 different genes. This paper shows the exciting applications of molecular modeling in the classification and characterization of genetic variants identified in next generation sequencing. Graphical abstract XIAP in Caspase 3 and NOD2 signaling pathways.
MeSH Terms
- Aging
- Apoptosis
- Caspase 3
- Cystic Fibrosis Transmembrane Conductance Regulator
- Genome, Human
- Genomics
- High-Throughput Nucleotide Sequencing
- Humans
- Models, Molecular
- Molecular Dynamics Simulation
- Mutation
- Nod2 Signaling Adaptor Protein
- Protein Binding
- Protein Structure, Tertiary
- Sequence Analysis, DNA
- Signal Transduction
- X-Linked Inhibitor of Apoptosis Protein
Keywords
- Caspase3
- Clinical variants
- Protein modeling
- RIPK2
- SMAC
- Undiagnosed and rare diseases
- XIAP
Functional modeling of many adult epithelia is limited by the difficulty in maintaining relevant stem cell populations in culture. Here, we show that dual inhibition of SMAD signaling pathways enables robust expansion of primary epithelial basal cell populations. We find that TGFβ/BMP/SMAD pathway signaling is strongly activated in luminal and suprabasal cells of several epithelia, but suppressed in p63 basal cells. In airway epithelium, SMAD signaling promotes differentiation, and its inhibition leads to stem cell hyperplasia. Using dual SMAD signaling inhibition in a feeder-free culture system, we have been able to expand airway basal stem cells from multiple species. Expanded cells can produce functional airway epithelium physiologically responsive to clinically relevant drugs, such as CFTR modulators. This approach is effective for the clonal expansion of single human cells and for basal cell populations from epithelial tissues from all three germ layers and therefore may be broadly applicable for modeling of epithelia.
MeSH Terms
- Animals
- Cell Differentiation
- Cell Proliferation
- Cell Self Renewal
- Cellular Senescence
- Cilia
- Epithelial Cells
- Epithelium
- Humans
- Keratinocytes
- Lung
- Mice, Inbred C57BL
- Mucus
- Signal Transduction
- Smad Proteins
- Telomere
Keywords
- TGFβ/BMP4/SMAD signaling
- dedifferentiation
- differentiation
- dual SMAD signaling inhibition
- epithelial basal and stems cells
- p63( ) basal cells
- replicative exhaustion
- senescence
- stemness
- telomeres
Cystic fibrosis (CF) is the result of mutations in the cystic fibrosis transmembrane conductance regulator (CFTR). CF-related diabetes affects 50% of adult CF patients. How CFTR deficiency predisposes to diabetes is unknown. Herein, we examined the impact of the most frequent cftr mutation in humans, deletion of phenylalanine at position 508 (ΔF508), on glucose homeostasis in mice. We compared ΔF508 mutant mice with wild-type (WT) littermates. Twelve-week-old male ΔF508 mutants had lower body weight, improved oral glucose tolerance, and a trend toward higher insulin tolerance. Glucose-induced insulin secretion was slightly diminished in ΔF508 mutant islets, due to reduced insulin content, but ΔF508 mutant islets were not more sensitive to proinflammatory cytokines than WT islets. Hyperglycemic clamps confirmed an increase in insulin sensitivity with normal β-cell function in 12- and 18-week-old ΔF508 mutants. In contrast, 24-week-old ΔF508 mutants exhibited insulin resistance and reduced β-cell function. β-Cell mass was unaffected at 11 weeks of age but was significantly lower in ΔF508 mutants versus controls at 24 weeks. This was not associated with gross pancreatic pathology. We conclude that the ΔF508 CFTR mutation does not lead to an intrinsic β-cell secretory defect but is associated with insulin resistance and a β-cell mass deficit in aging mutants.
MeSH Terms
- Aging
- Animals
- Crosses, Genetic
- Cystic Fibrosis
- Cystic Fibrosis Transmembrane Conductance Regulator
- Diabetes Mellitus
- Down-Regulation
- Female
- Humans
- Immunohistochemistry
- Insulin
- Insulin Resistance
- Insulin Secretion
- Insulin-Secreting Cells
- Islets of Langerhans
- Male
- Mice, Inbred Strains
- Mice, Mutant Strains
- Mutation
- Tissue Culture Techniques
Benign prostatic hyperplasia (BPH) is a hyper-proliferative disease of the aging prostate; however, the exact mechanism underlying the development of BPH remains incompletely understood. The present study investigated the possible involvement of the cystic fibrosis transmembrane conductance regulator (CFTR), which has been previously shown to negatively regulate nuclear factor-κB (NF-κB)/cyclooxygenase 2 (COX2)/prostaglandin E2 (PGE2) pathway, in the pathogenesis of BPH. Our results showed decreasing CFTR and increasing COX2 expression in rat prostate tissues with aging. Furthermore, suppression of CFTR led to increased expression of COX2 and over-production of PGE2 in a normal human prostate epithelial cell line (PNT1A) with elevated NF-κB activity. PGE2 stimulated the proliferation of primary rat prostate stromal cells but not epithelial cells, with increased PCNA expression. In addition, the condition medium from PNT1A cells after inhibition or knockdown of CFTR promoted cell proliferation of prostate stromal cells which could be reversed by COX2 or NF-κB inhibitor. More importantly, the involvement of CFTR in BPH was further demonstrated by the down-regulation of CFTR and up-regulation of COX2/NF-κB in human BPH samples. The present results suggest that CFTR may be involved in regulating PGE2 production through its negative regulation on NF-κB/COX2 pathway in prostate epithelial cells, which consequently stimulates cell growth of prostate stromal cells. The overstimulation of prostate stromal cell proliferation by down-regulation of CFTR-enhanced PGE2 production and release during aging may contribute to the development of BPH.
MeSH Terms
- Aging
- Animals
- Blotting, Western
- Cell Line, Tumor
- Cyclooxygenase 2
- Cystic Fibrosis Transmembrane Conductance Regulator
- Dinoprostone
- Disease Models, Animal
- Down-Regulation
- Fluorescent Antibody Technique
- Humans
- Immunohistochemistry
- Male
- NF-kappa B
- Prostatic Hyperplasia
- Rats
- Rats, Sprague-Dawley
- Real-Time Polymerase Chain Reaction
- Reverse Transcriptase Polymerase Chain Reaction
- Signal Transduction
- Transfection
Cystic fibrosis (CF) is a multiorgan disease caused by loss of a functional cystic fibrosis transmembrane conductance regulator (CFTR) chloride channel in many epithelia of the body. Here we report the pathology observed in the gastrointestinal organs of juvenile to adult CFTR-knockout ferrets. CF gastrointestinal manifestations included gastric ulceration, intestinal bacterial overgrowth with villous atrophy, and rectal prolapse. Metagenomic phylogenetic analysis of fecal microbiota by deep sequencing revealed considerable genotype-independent microbial diversity between animals, with the majority of taxa overlapping between CF and non-CF pairs. CF hepatic manifestations were variable, but included steatosis, necrosis, biliary hyperplasia, and biliary fibrosis. Gallbladder cystic mucosal hyperplasia was commonly found in 67% of CF animals. The majority of CF animals (85%) had pancreatic abnormalities, including extensive fibrosis, loss of exocrine pancreas, and islet disorganization. Interestingly, 2 of 13 CF animals retained predominantly normal pancreatic histology (84% to 94%) at time of death. Fecal elastase-1 levels from these CF animals were similar to non-CF controls, whereas all other CF animals evaluated were pancreatic insufficient (<2 μg elastase-1 per gram of feces). These findings suggest that genetic factors likely influence the extent of exocrine pancreas disease in CF ferrets and have implications for the etiology of pancreatic sufficiency in CF patients. In summary, these studies demonstrate that the CF ferret model develops gastrointestinal pathology similar to CF patients.
MeSH Terms
- Aging
- Animals
- Atrophy
- Bacteria
- Cystic Fibrosis
- Cystic Fibrosis Transmembrane Conductance Regulator
- Ferrets
- Gastrointestinal Tract
- Gene Knockout Techniques
- Humans
- Mucus
- Organ Specificity
Sperm quality declines with aging; however, the underlying molecular mechanism remains elusive. The cystic fibrosis transmembrane conductance regulator (CFTR) has been shown to play an essential role in fertilizing capacity of sperm and male fertility. This study aimed to investigate the involvement of age-dependent CFTR downregulation in lowering sperm quality in old age. Two hundred and one healthy fertile men of three age groups (20-40 years, n=64; 40-60 years, n=61; and >60 years, n=76) were recruited. Expression of CFTR was determined by RT-PCR, western blot, and immunofluorescence staining. Collected sperm were treated with CFTR inhibitor or potentiator. Sperm quality was assessed by motility and bicarbonate-induced capacitation. The results showed that the expression of CFTR on the equatorial segment and neck region of sperm was significantly decreased in an age-dependent manner. Reduction of CFTR expression in sperm from old men was correlated with lowered forward motility and decreased HCO3(-) sensitivity required for sperm capacitation. Activation of CFTR by genistein partially rescued the decreased forward motility in sperm from old men. Decreased CFTR expression in sperm was also found to be associated with lowered sperm quality in aging mice. These results suggest that age-dependent downregulation of CFTR in sperm leads to lowered sperm quality in old age sperm. CFTR may be a pontential target for rescuing sperm motility as well as a fertility indicator in old age men.
MeSH Terms
- Adult
- Aged
- Aged, 80 and over
- Aging
- Animals
- Cystic Fibrosis Transmembrane Conductance Regulator
- Down-Regulation
- Humans
- Male
- Mice
- Mice, Inbred C57BL
- Middle Aged
- Semen Analysis
- Spermatozoa
- Young Adult
Cystic fibrosis transmembrane conductance regulator (CFTR) has been demonstrated to be expressed in mature spermatozoa and correlated with sperm quality. Sperm CFTR expression in fertile men is higher than that in infertile men suffering from teratospermia, asthenoteratospermia, asthenospermia and oligospermia, but it is unknown whether CFTR is correlated with sperm parameters when sperm parameters are normal. In this study, 282 healthy and fertile men with normal semen parameters were classified into three age groups, group (I): age group of 20-29 years (98 cases, 27.1 ± 6.2), group (II): age group of 30-39 years (142 cases, 33.7 ± 2.6) and group (III): age group of more than or equal to 40 years (42 cases, 44.1 ± 4.6). Sperm concentration, total count and progressive motility were analysed by computer-assisted sperm analysis. Sperm morphology was analysed by modified Papanicolaou staining. Sperm CFTR expression was conducted by indirect immunofluorescence staining. There was a significant positive correlation (P < 0.001) between CFTR expression and sperm progressive motility (r = 0.221) and normal morphology (r = 0.202), but there were no correlations between sperm CFTR expression and semen volume, sperm concentration, sperm total count as well as male age (P > 0.05). Our findings show that CFTR expression is associated with sperm progressive motility and normal morphology in healthy and fertile men with normal sperm parameters, but not associated with the number of spermatozoa and male age.
MeSH Terms
- Adult
- Aging
- Biomarkers
- Cystic Fibrosis Transmembrane Conductance Regulator
- Fertility
- Healthy Volunteers
- Humans
- Male
- Middle Aged
- Sperm Motility
- Spermatozoa
- Young Adult
Keywords
- Age
- cystic fibrosis transmembrane conductance regulator
- human spermatozoa
- morphology
- motility
Chronic sinusitis is nearly universal in humans with cystic fibrosis (CF) and is accompanied by sinus hypoplasia (small sinuses). However, whether impaired sinus development is a primary feature of loss of the cystic fibrosis transmembrane conductance regulator (CFTR) or a secondary consequence of chronic infection remains unknown. Our objective was to study the early pathogenesis of sinus disease in CF. Animal/basic science research. Sinus development was studied in a porcine CF model. Porcine sinus epithelia expressed CFTR and exhibited transepithelial anion transport. Disruption of the CFTR gene eliminated both. Sinuses of newborn CF pigs were not infected and showed no evidence of inflammation, yet were hypoplastic at birth. Older CF pigs spontaneously developed sinus disease similar to that seen in humans with CF. These results define a role for CFTR in sinus development and suggest the potential of the CF pig as a genetic model of CF-sinus disease in which to test therapeutic strategies to minimize sinus-related CF morbidity.
MeSH Terms
- Aging
- Animals
- Animals, Newborn
- Biopsy, Needle
- Chronic Disease
- Cystic Fibrosis
- Cystic Fibrosis Transmembrane Conductance Regulator
- Disease Models, Animal
- Female
- Gene Expression Regulation, Developmental
- Genetic Predisposition to Disease
- Immunohistochemistry
- Incidence
- Male
- Nasal Mucosa
- Organogenesis
- Paranasal Sinuses
- Random Allocation
- Reference Values
- Risk Assessment
- Sinusitis
- Swine
The F508del mutation in the cystic fibrosis transmembrane conductance regulator (Cftr) gene is believed to be an independent risk factor for cystic fibrosis-related bone disease. In this study, we evaluated the bone mineral density as well as the histomorphometric parameters of bone formation and bone mass in both F508del-Cftr homozygous mice (F508del Cftr(tm1Eur)) and Cftr( / ) littermate controls at 6 (prepubertal), 10 (pubertal), and 14 (young adult) weeks of age in both sexes. The bone architecture of F508del Cftr(tm1Eur) and wild-type (WT) littermate mice was evaluated by bone densitometry, microcomputed tomography, and analysis of the dynamic parameters of bone formation. Serum levels of both insulin-like growth factor 1 and osteocalcin also were determined. Reduced bone mineral density, lower femoral bone mass, and altered trabecular bone architecture were observed in F508del Cftr(tm1Eur) mice compared with controls at 6, 10, and 14 weeks of age. A decrease in the bone formation rate in F508del Cftr(tm1Eur) mice was shown compared with control mice, independently of age and sex. In addition, we found lower insulin-like growth factor 1 levels in F508del Cftr(tm1Eur) mice compared with age-matched controls, whereas osteocalcin levels were normal. Severe osteopenia and altered bone architecture were found in young and mature adult F508del Cftr(tm1Eur) mice. Our findings show that the F508del mutation in CFTR impacts trabecular bone mass by reducing bone formation.
MeSH Terms
- Aging
- Animals
- Base Sequence
- Bone Density
- Bone Diseases, Metabolic
- Cystic Fibrosis
- Cystic Fibrosis Transmembrane Conductance Regulator
- Female
- Femur
- Male
- Mice
- Mice, Inbred CFTR
- Osteogenesis
- Sequence Deletion
Since the discovery of the human CFTR gene in 1989 various mouse models for cystic fibrosis (CF) have been generated and used as a very suitable and popular tool to approach research on this life-threatening disease. Age related changes regarding the course of disease and susceptibility towards pulmonary infections have been discussed in numerous studies. Here, we investigated CftrTgH(neoim)Hgu and Cftrtm1Unc-Tg(FABPCFTR)1Jaw/J CF mice and their non-CF littermates during an acute lung infection with Pseudomonas aeruginosa for age dependent effects of their lung function and immune response.Mice younger than three or older than six months were intratracheally infected with P. aeruginosa TBCF10839. The infection was monitored by lung function of the animals using non-invasive head-out spirometry and the time course of physiological parameters over 192 hours. Quantitative bacteriology and lung histopathology of a subgroup of animals were used as endpoint parameters. Age-dependent changes in lung function and characteristic features for CF like a shallower, faster breathing pattern were observed in both CF mouse models in uninfected state. In contrast infected CF mice did not significantly differ from their non-CF littermates in susceptibility and severity of lung infection in both mouse models and age groups. The transgenic Cftrtm1Unc-Tg(FABPCFTR)1Jaw/J and their non-CF littermates showed a milder course of infection than the CftrTgH(neoim)Hgu CF and their congenic C57Bl/6J non-CF mice suggesting that the genetic background was more important for outcome than Cftr dysfunction. Previous investigations of the same mouse lines have shown a higher airway susceptibility of older CF mice to intranasally applied P. aeruginosa. The different outcome of intranasal and intratracheal instillation of bacteria implies that infected CF epithelium is impaired during the initial colonization of upper airways, but not in the subsequent response of host defense.
MeSH Terms
- Aging
- Animals
- Cystic Fibrosis
- Cystic Fibrosis Transmembrane Conductance Regulator
- Mice
- Mice, Transgenic
- Pneumonia, Bacterial
- Pseudomonas Infections
- Pseudomonas aeruginosa
- Respiratory Function Tests
- Tracheitis
Cystic fibrosis (CF), caused by reduced CFTR function, includes severe sinonasal disease which may predispose to lung disease. Newly developed CF pigs provide models to study the onset of CF pathophysiology. We asked if glands from pig nasal turbinates have secretory responses similar to those of tracheal glands and if CF nasal glands show reduced fluid secretion. Unexpectedly, we found that nasal glands differed from tracheal glands in five ways, being smaller, more numerous (density per airway surface area), more sensitive to carbachol, more sensitive to forskolin, and nonresponsive to Substance P (a potent agonist for pig tracheal glands). Nasal gland fluid secretion from newborn piglets (12 CF and 12 controls) in response to agonists was measured using digital imaging of mucus bubbles formed under oil. Secretion rates were significantly reduced in all conditions tested. Fluid secretory rates (Controls vs. CF, in pl/min/gland) were as follows: 3 µM forskolin: 9.2±2.2 vs. 0.6±0.3; 1 µM carbachol: 143.5±35.5 vs. 52.2±10.3; 3 µM forskolin 0.1 µM carbachol: 25.8±5.8 vs. CF 4.5±0.9. We also compared CF(ΔF508/ΔF508) with CFTR(-/-) piglets and found significantly greater forskolin-stimulated secretion rates in the ΔF508 vs. the null piglets (1.4±0.8, n = 4 vs. 0.2±0.1, n = 7). An unexpected age effect was also discovered: the ratio of secretion to 3 µM forskolin vs. 1 µM carbachol was ∼4 times greater in adult than in neonatal nasal glands. These findings reveal differences between nasal and tracheal glands, show defective fluid secretion in nasal glands of CF pigs, reveal some spared function in the ΔF508 vs. null piglets, and show unexpected age-dependent differences. Reduced nasal gland fluid secretion may predispose to sinonasal and lung infections.
MeSH Terms
- Aging
- Animals
- Animals, Newborn
- Body Fluids
- Carbachol
- Colforsin
- Cystic Fibrosis
- Cystic Fibrosis Transmembrane Conductance Regulator
- Drug Synergism
- Exocrine Glands
- Mutation
- Organ Size
- Substance P
- Sus scrofa
- Trachea
- Turbinates
The survival of patients with cystic fibrosis (CF) continues to improve. The discovery and cloning of the CFTR gene more than 21 years ago led to the identification of the structure and function of the CFTR chloride channel. New therapies based on the understanding of the function of CFTR are currently under development. The better clinical status and improved survival of patients with CF is not only a result of understanding of the molecular mechanisms of CF but also a result of the development of therapeutic strategies that are based on insights into the natural course of the disease. Current CF treatments that target respiratory infections, inflammation, mucociliary clearance, and nutritional status are associated with improved pulmonary function and reduced exacerbations. Patients benefit from treatment at a specialized CF center by a multidisciplinary dedicated team with emphasis being placed on frequent visits, periodic testing, and monitoring adherence to therapy. The purpose of this review is to survey recent developments in CF care that are responsible for the improved survival and quality of life of patients with CF.
MeSH Terms
- Cystic Fibrosis
- Cystic Fibrosis Transmembrane Conductance Regulator
- Humans
- Inflammation
- Life Expectancy
- Mucociliary Clearance
- Pseudomonas Infections
- Pseudomonas aeruginosa
- Quality of Life
The life expectancy of people with cystic fibrosis (CF), a lethal inherited disease, has been greatly extended by advances in therapy. Currently, there are a number of potential drugs for treatment of CF lung disease in clinical trials. These therapies are targeted at all points in the pathogenesis of lung disease, from gene transfer to drugs that treat mucus, infection and inflammation in the airways. An exciting development is that of modulation of the abnormal protein that causes CF, the cystic fibrosis transmembrane conductance regulator (CFTR), where drugs are targeted at specific defects in CFTR transcription, processing or functioning. Inhaled therapies are being developed to augment airway surface liquid height, either by modulating the abnormal ion channel function in the airway epithelial cell or by rehydrating with osmotic agents. Anti-inflammatory therapy is also of great interest in CF and there are several candidate drugs in clinical trials. A number of antibacterial agents formulated for inhalation are at various stages of study or newly approved, which should improve options for chronic management of airway infection. Hopefully, many of these potential therapies will come to market and will further extend the life expectancy of people with CF.
MeSH Terms
- Animals
- Anti-Bacterial Agents
- Anti-Inflammatory Agents
- Clinical Trials as Topic
- Cystic Fibrosis
- Cystic Fibrosis Transmembrane Conductance Regulator
- Drug Delivery Systems
- Drug Design
- Humans
- Life Expectancy
Hypersecretion of chloride can cause diarrhea, a disease frequently occurring in young pigs, particularly around weaning. We investigated the contribution of different channels to intestinal Cl(-) secretion as influenced by age and weaning. Jejunal and colonic epithelia from 4-month-old pigs and 4-week-old piglets were incubated in Ussing chambers and stimulated by carbachol and forskolin. Changes in short-circuit currents were taken as measure of electrogenic net Cl(-) secretion. DIDS or NPPB served to inhibit Ca-activated Cl(-)-channels and outwardly rectifying Cl(-)-channels (ORCC) or cystic fibrosis transmembrane regulator (CFTR), respectively. Depolarizing the basolateral membrane allowed to examine the influence of K( )-channels on Cl(-) secretion. Forskolin-stimulated Cl(-) secretion was mediated by CFTR. ORCC were not involved. Carbachol-induced Cl(-) secretion could be ascribed to an enhanced driving force due to the opening of K( )-channels, whereas Ca-dependent Cl(-) channels seemed not to be involved. In jejunum, piglets showed higher Cl(-) secretion than pigs. Two days after weaning forskolin induced an I (sc) overshoot and a faster increase in G (t). In colon, Cl(-) secretion was neither influenced by age nor by weaning. The data suggest a disposition of porcine jejunum for a higher Cl(-) secretion in young and freshly weaned piglets, which might be a natural defense mechanism as well as a predisposing factor for diarrhea.
MeSH Terms
- Aging
- Animals
- Animals, Suckling
- Chloride Channel Agonists
- Chloride Channels
- Colon
- Cystic Fibrosis Transmembrane Conductance Regulator
- Diarrhea
- Female
- Jejunum
- Male
- Membrane Potentials
- Orchiectomy
- Protein Isoforms
- Swine
- Swine Diseases
- Weaning
The expression and localization of the cystic fibrosis transmembrane conductance regulator (CFTR) were determined in four osmoregulatory tissues during the ontogeny of the sea-bass Dicentrarchus labrax acclimated to fresh water and sea water. At hatch in sea water, immunolocalization showed an apical CFTR in the digestive tract and integumental ionocytes. During the ontogeny, although CFTR was consistently detected in the digestive tract, it shifted from the integument to the gills. In fresh water, CFTR was not present in the integument and the gills, suggesting the absence of chloride secretion. In the kidney, the CFTR expression was brief from D4 to D35, prior to the larva-juvenile transition. CFTR was apical in the renal tubules, suggesting a chloride secretion at both salinities, and it was basolateral only in sea water in the collecting ducts, suggesting chloride absorption. In the posterior intestine, CFTR was located differently from D4 depending on salinity. In sea water, the basolateral CFTR may facilitate ionic absorption, perhaps in relation to water uptake. In fresh water, CFTR was apical in the gut, suggesting chloride secretion. Increased osmoregulatory ability was acquired just before metamorphosis, which is followed by the sea-lagoon migration.
MeSH Terms
- Aging
- Animals
- Bass
- Blotting, Western
- Cystic Fibrosis Transmembrane Conductance Regulator
- Digestive System
- Gills
- Kidney
- Larva
- Salinity
- Water-Electrolyte Balance
To describe the epidemiological, physiopathological, clinical and therapeutic knowledge concerning cystic fibrosis (CF). Important modifications in the health organization of the care concerning this orphan disease have been implemented in France. The life expectancy has dramatically increased, as well as the knowledge concerning the pathological structure and function of the CFTR gene and protein. This will lead to the development of emerging drug treatments for this lethal disease. The life expectancy is predicted to exceed 40 years for children born in the 2000s. As a result, there has been a tremendous growth of the adult population that reached 40% of the overall approximately 5000 patients included in the CF French registry (Observatoire National de la Mucoviscidose). Lung disease remains the primary cause of morbidity and mortality. The characteristic phenotypic presentation associates bronchial and rhinosinusal symptoms, pancreatic insufficiency and liver disease. Bronchial damage leads to progressive chronic respiratory insufficiency. Diabetes mellitus and osteoporosis frequently appears in adulthood. Neonatal screening has been implemented in France since 2002. It will prevent delayed diagnosis and its deleterious consequences. Some atypical cases of CF presenting only with one or two organ system involvement can be diagnosed in adulthood. Isolated chronic rhinosinusitis, bronchiectasis, congenital bilateral absence of vas deferens, recurrent pancreatitis, allergic bronchopulmonary aspergillosis, and some case of cholangitis may so revealed late form of cystic fibrosis. The health care is organized in cystic fibrosis centres. Despite gene discovery, treatment still remains symptomatic, based on intensive pulmonary and nutritional treatments. Challenges for new treatments are to correct the basic defect, either by gene therapy or by pharmacological modulation of the abnormal physiological processes.
MeSH Terms
- Adult
- Cystic Fibrosis
- Cystic Fibrosis Transmembrane Conductance Regulator
- France
- Genetic Therapy
- Humans
- Life Expectancy
- Lung Diseases
- Mutation
- Nutritional Status
- Phenotype
- Registries
Cystic Fibrosis (CF) is one of the most frequent genetic diseases in the white populations of Europe and North America. Its clinical manifestations are highly variable, ranging from a characteristic life-shortening pathology of the lungs and the pancreas in classical CF to symptoms mainly restricted to male sterility in patients with congenital bilateral aplasia of the vasa deferentia (CBAVD). The genetic basis of CF is mutations in both copies of the CFTR gene, which codes for an ion channel. Even though one single mutation, deltaF508, is responsible for two-thirds of all mutated CFTR alleles, a total of over 1000 CFTR mutations have been described, whose relative frequencies vary between different ethnic groups, and whose biochemical consequences are correlated to the clinical manifestations of the disease. Since 4% of white Europeans and North Americans are healthy heterozygous carriers of CF, the molecular diagnosis of this disease, offered in the context of genetic counselling by a specialist in human genetics, is of great importance.
MeSH Terms
- Alleles
- Chromosome Aberrations
- Cross-Cultural Comparison
- Cystic Fibrosis
- Cystic Fibrosis Transmembrane Conductance Regulator
- DNA Mutational Analysis
- Ethnic Groups
- Genes, Recessive
- Genetic Carrier Screening
- Genetic Counseling
- Genetic Testing
- Genotype
- Humans
- Longevity
- Phenotype
Most cystic fibrosis (CF) transmembrane receptor mutations are rare. The French CF Registry offers an opportunity to study the genotype-phenotype relationship of these rare alleles. Since 1992, 39 CF patients carrying one copy of the 3849 10kbC->T mutation and 88 the 2789 5G->A allele have been seen at least once in a CF care centre. Among them, 16 carrying the 3849 10kbC->T/Delta F508 genotype and 34 with the 2789 5G->A/Delta F508 genotype were seen in 2000. Their age at diagnosis, sweat chloride concentration, anthropometric and lung function results, and clinical aspects were compared with those homozygous for the Delta F508 mutation matched for sex, age and CF care centre. Major differences, most of them statistically significant, in the age at diagnosis, prevalence of pancreatic insufficiency, and other clinical signs, anthropometric and lung function measures were observed between both compound heterozygote groups and their matched Delta F508/Delta F508 groups. The mean sweat chloride concentration was also lower (close to normal values) among 3849 10kbC->T/Delta F508 patients, but not among 2789 5G->A/Delta F508 patients. In conclusion, both mutations studied here are associated with a milder course of cystic fibrosis disease. The 3849 10kbC->T and 2789 5G->A alleles are splice site mutations, leading to abnormal mRNA; however, a small amount of normally spliced transcripts can also be detected. The presence of these small amounts of normal cystic fibrosis transmembrane receptor protein in these cystic fibrosis patients is likely to be responsible for the milder severity of disease and a better life expectancy.
MeSH Terms
- Adult
- Age Distribution
- Age of Onset
- Alleles
- Body Size
- Comorbidity
- Cystic Fibrosis
- Cystic Fibrosis Transmembrane Conductance Regulator
- Exocrine Pancreatic Insufficiency
- Female
- France
- Genotype
- Humans
- Life Expectancy
- Male
- Phenotype
- Registries
- Sex Distribution
Guanylin-like peptides regulate electrolyte/water transport through the epithelia. Moreover, these peptides possess antiproliferative activity and regulate the turnover of epithelial cells. In an earlier study we localized guanylin immunoreactivity in secretory ducts of adult rodent salivary glands. In this study we investigated the appearance and distribution pattern of this peptide during the development of rat salivary glands. Guanylin immunoreactivity appeared at the beginning of cell differentiation from solid bud, on embryonic day 17 in the submandibular and sublingual glands and after day 18 in the parotid gland. Guanylin immunoreactivity appeared first in ductal and acinar anlage: its cell distribution pattern and fate differed in these two compartments. In the duct cells guanylin immunoreactivity spread after the duct system developed, whereas in acinar cells it disappeared after cell differentiation. The guanylin immunoreactivity we detected in adult salivary duct cells accords with guanylin's role in regulating electrolyte and water transport through the various epithelia. It does so by activating guanylate cyclase-C receptor, increasing intracellular cGMP concentration, and phosphorylating the cystic fibrosis transmembrane conductance regulator (CFTR) protein by the cGMP-dependent protein kinase II. This signaling cascade couples to the ductal electrolyte/water secretion and modulates finally the electrolyte composition of the saliva. On the other hand, CFTR is also involved in mechanisms of cell growth, by regulating apoptosis, and promoting cell differentiation. The early diffuse guanylin immunoreactivity we observed in ducts and acinar anlage, before the secretory set is operative, suggests guanylin has a role in cell differentiation.
MeSH Terms
- Aging
- Animals
- Animals, Newborn
- Embryo, Mammalian
- Embryonic and Fetal Development
- Gastrointestinal Hormones
- Gestational Age
- Immunohistochemistry
- Natriuretic Peptides
- Peptides
- Rats
- Rats, Wistar
- Salivary Glands
- Tissue Distribution
Mouse models for cystic fibrosis (CF) mimic intestinal manifestations of the human disease, but the lung disease phenotypes are lacking in most strains. In this work, the issue was addressed whether aging of the respiratory tract leads to lung pathophysiology in the exon 10 insertional mutant cftr(tm1Hgu) mouse. Weight gain, body weight and life-span of cftr(tm1Hgu) mice were significantly reduced compared with control mice. cftr(tm1Hgu) mice expressed 20, 21 or 37% (median) of wild-type cystic fibrosis conductance transmembrane regulator (cftr) mRNA transcript in lungs, intestine and kidney. Wild-type cftr mRNA in renal and respiratory epithelia varied with age from levels similar to Ztm:MF1 controls at the age of 2 and 4 months to levels seen in patients with CFTR splice mutations beyond the age of 6 months. The morphology of the bronchi and more distal airways was apparently normal in cftr(tm1Hgu) mice during their first year of life. The alveolar surfactant phospholipid pool was increased in cftr(tm1Hgu) mice by 1.5- to 2-fold compared with Ztm:MF1 controls. Alveolar clearance of gamma-labelled scandium oxide - the first report of lung clearance measurement in living mice - was reduced in cftr(tm1Hgu) mice compared with littermate controls. Although no progressive lung pathology was seen in the cftr expression of cftr(tm1Hgu) mice, surfactant phospholipid homeostasis, and alveolar and mucociliary clearance were abnormal. Therefore, the described model is useful for studying the initial CF lung pathophysiology.
MeSH Terms
- Aging
- Animals
- Body Weight
- Bronchoalveolar Lavage Fluid
- Cystic Fibrosis
- Cystic Fibrosis Transmembrane Conductance Regulator
- Intestinal Mucosa
- Kidney
- Lung
- Mice
- Mice, Inbred CFTR
- Models, Animal
- Mucociliary Clearance
- Mutation
- Phospholipids
- RNA, Messenger
- Reverse Transcriptase Polymerase Chain Reaction
Chloride transport is critical to many functions of the lung. Molecular defects in the best-known chloride channel, cystic fibrosis transmembrane conductance regulator (CFTR), lead to impaired function of airway defensins, hydration of airway surface fluid, and mucociliary clearance leading to chronic lung disease, and premature death, but do not cause defects in lung development. We examined the expression of one member of the ClC family of volume- and voltage-regulated channels using the ribonuclease protection assay and Western blot analysis in rats. ClC-5 mRNA and protein are most strongly expressed in the fetal lung, and expression is maintained although downregulated postnatally. In addition, using immunocytochemistry, we find that ClC-5 is predominantly expressed along the luminal surface of the airway epithelium, suggesting that ClC-5 may participate in lung chloride secretion. Identifying candidate genes for critical ion transport functions is essential for understanding normal lung morphogenesis and the pathophysiology of several lung diseases. In addition, the manipulation of non-CFTR chloride channels may provide a viable approach for treating cystic fibrosis lung disease.
MeSH Terms
- Aging
- Animals
- Animals, Newborn
- Chloride Channels
- Embryonic and Fetal Development
- Epithelium
- Fetus
- Lung
- RNA, Messenger
- Rats
- Rats, Sprague-Dawley
- Tissue Distribution
- Trachea
Homologous disruption of the murine gene encoding the cystic fibrosis (CF) transmembrane conductance regulator (CFTR) leads to the loss of cAMP-mediated ion transport. Mice carrying this gene defect exhibit meconium ileus at birth and gastrointestinal plugging during the neonatal period, both contributing to high rates of mortality. We investigated whether infectious mammalian rotavirus, the recently characterized rotaviral enterotoxin protein NSP4, or its active NSP4(114-135) peptide, can overcome these gastrointestinal complications in CF (CFTR(m3Bay) null mutation) mice. All three agents elicited diarrhea when administered to wild-type (CFTR( / )), heterozygous (CFTR( /-)), or homozygous (CFTR(-/-)) 7- to 14-day-old mouse pups but were ineffective when given to older mice. The diarrheal response was accompanied by non-age-dependent intracellular Ca(2 ) mobilization within both small and large intestinal crypt epithelia. Significantly, NSP4 elicited cellular I(-) influx into intestinal epithelial cells from all three genotypes, whereas both carbachol and the cAMP-mobilizing agonist forskolin failed to evoke influx in the CFTR(-/-) background. This unique plasma membrane halide permeability pathway was age dependent, being observed only in mouse pup crypts, and was abolished by either the removal of bath Ca(2 ) or the transport inhibitor DIDS. These findings indicate that NSP4 or its active peptide may induce diarrhea in neonatal mice through the activation of an age- and Ca(2 )-dependent plasma membrane anion permeability distinct from CFTR. Furthermore, these results highlight the potential for developing synthetic analogs of NSP4(114-135) to counteract chronic constipation/obstructive bowel syndrome in CF patients.
MeSH Terms
- Administration, Oral
- Aging
- Animals
- Animals, Newborn
- Biological Transport
- Calcium
- Cell Membrane Permeability
- Cystic Fibrosis
- Cystic Fibrosis Transmembrane Conductance Regulator
- Diarrhea
- Glycoproteins
- Injections
- Intestinal Mucosa
- Intracellular Membranes
- Iodides
- Mice
- Microvilli
- Peptide Fragments
- Reference Values
- Toxins, Biological
- Viral Nonstructural Proteins
The cystic fibrosis transmembrane conductance regulator (CFTR) protein is a small conductance adenosine 3',5'-cyclic monophosphate (cAMP)-activated chloride ion channel found in the apical membranes of epithelia within the pancreas, airway, intestine, bile duct, sweat gland, and male genital ducts. Pancreatic insufficiency is a feature of about 85% of patients with cystic fibrosis and is believed to be caused by pancreatic autolysis after pancreatic duct obstruction. The aim of this study was to investigate the expression of CFTR in the pancreas from early development to postnatal life to establish whether the CFTR plays a key role in development of the pancreatic duct epithelium. Expression of CFTR from the start of the mid-trimester of human development through term to adult life by messenger RNA (mRNA) in situ hybridization was examined. CFTR mRNA is detected throughout the pancreatic duct epithelium and its pattern of expression follows the differentiation of the duct system. CFTR is a valuable marker of human pancreatic duct cell development and differentiation.
MeSH Terms
- Aging
- Biomarkers
- Cystic Fibrosis Transmembrane Conductance Regulator
- Embryonic and Fetal Development
- Fetus
- Humans
- Infant
- Infant, Newborn
- Pancreatic Ducts
- RNA, Messenger
Chloride channels supply critical functions in epithelial cells throughout the body. Although function of the volume- and voltage-gated C1C-2 is uncertain, its wide tissue distribution of mRNA suggests C1C-2 has important housekeeping functions. This study's objective was to identify the extent of not only C1C-2 mRNA expression but also protein expression as a measure of the capacity for C1C-2 chloride secretion in epithelial tissues. Using quantitative ribonuclease protection assay, we found that C1C-2 mRNA transcripts were abundant in fetal and postnatal brain, fetal kidney, liver, intestine, and lung. In contrast to brain, C1C-2 mRNA transcripts were downregulated during late gestation in lung, kidney, and intestine. The lung expressed the least C1C-2 mRNA. Immunoblotting demonstrated similar tissue- and gestation-dependent variations in C1C-2 protein expression. To determine if there is a correlation between the sites of C1C-2 protein expression and cystic fibrosis transmembrane conductance regulator (CFTR), another epithelial chloride channel, a polyclonal COOH-terminal C1C-2 antibody and an anti-R domain CFTR anti-body were used. C1C-2 and CFTR were expressed in different sites in lung and kidney.
MeSH Terms
- Aging
- Animals
- Animals, Newborn
- Brain
- Chloride Channels
- Embryonic and Fetal Development
- Female
- Fetus
- Gene Expression Regulation, Developmental
- Gestational Age
- Immunohistochemistry
- Intestinal Mucosa
- Kidney
- Liver
- Lung
- Nerve Tissue Proteins
- Organ Specificity
- Pregnancy
- RNA, Messenger
- Rats
- Rats, Sprague-Dawley
- Transcription, Genetic
Cystic fibrosis transmembrane conductance regulator (CFTR) mRNA and protein are expressed in proximal and distal tubules of the human kidney, but CFTR expression pattern during human nephrogenesis is unknown. We have now studied CFTR expression in fetal kidneys by immunohistochemistry and Western blot analysis, using six antibodies against human CFTR. CFTR was expressed in 12-wk human fetal kidneys, mostly in the apical membrane region of the ureteric bud epithelial cells. By 15 wk, CFTR was also diffusely expressed throughout the cytoplasm of proximal tubules and loops of Henle. No glomerular staining was seen at any state. From 15 to 24 wk of gestation this staining pattern remained constant and also included immunoreactivity of the transitional epithelium. Western blot for CFTR was performed on membrane extracts of human fetal kidneys, using T84 cells as a positive control. A 165-kDa protein corresponding to the predicted size of CFTR was seen at 13 wk and throughout development. We also observed a 75-kDa protein that was distinctly regulated during development. This protein was detected with several antibodies against the first half of CFTR (including the regulatory "R" domain) but not with a COOH-terminal-specific antibody and had the predicted size of a functional splice variant of CFTR identified in the human kidney. These results show the complex regulation of CFTR during nephrogenesis and raise the question of the respective roles of the full-length and the splice variant CFTR proteins in the human kidney.
MeSH Terms
- Adolescent
- Adult
- Aging
- Blotting, Western
- Child
- Child, Preschool
- Cystic Fibrosis Transmembrane Conductance Regulator
- Embryo, Mammalian
- Embryonic and Fetal Development
- Humans
- Immunohistochemistry
- Infant
- Infant, Newborn
- Kidney
- Tissue Distribution
Mouse models for cystic fibrosis (CF) with no CFTR function (Cftr-/-) have the disadvantage that most animals die of intestinal obstruction shortly after weaning. The objective of this research was to extend the lifespan of CF mice and characterize their phenotype. Weanlings were placed on a nutrient liquid diet, and histologic and functional aspects of organs implicated in the disease were subsequently examined. Approximately 90% of Cftr-/- mice survived to 60 d, the majority beyond 100 d. Cftr-/- mice were underweight and had markedly abnormal intestinal histology. The intestinal epithelia did not respond to challenges with agents that raised intracellular cAMP, consistent with the absence of functional CFTR. No lesions or functional abnormalities were evident in the lungs. Liquid-fed Cftr-/- mice were infertile, although some males weaned to a solid diet were fertile before they died. Thus, we have succeeded in using dietary means to prolong the lives of Cftr-/- mice.
MeSH Terms
- Animals
- Cystic Fibrosis
- Diet
- Disease Models, Animal
- Female
- Genitalia
- Intestines
- Longevity
- Male
- Mice
- Mice, Inbred CFTR
- Pancreas
- Phenotype
- Respiratory System