Project description:COL4A3/A4/A5 mutations have been identified as critical causes of Alport syndrome and other genetic chronic kidney diseases. However, the underlying pathogenesis remains unclear, and specific treatments are lacking. Here, we constructed a transgenic Alport syndrome mouse model by generating a mutation (Col4a3 p.G799R) identified previously from one large Alport syndrome family into mice. We observed that the mutation caused a pathological decrease in intracellular and secreted collagen IV α3α4α5 heterotrimers. The mutant collagen IV α3 chains abnormally accumulated in the endoplasmic reticulum and exhibited defective secretion, leading to persistent endoplasmic reticulum stress in vivo and in vitro. RNA-seq analysis revealed that the MyD88/p38 MAPK pathway plays key roles in mediating subsequent inflammation and apoptosis signaling activation. Treatment with tauroursodeoxycholic acid, a chemical chaperone drug that functions as an endoplasmic reticulum stress inhibitor, effectively suppressed endoplasmic reticulum stress, promoted secretion of the α3 chains, and inhibited the activation of the MyD88/p38 MAPK pathway. Tauroursodeoxycholic acid treatment significantly improved renal function in vivo. These results partly clarified the pathogenesis of renal injuries associated with Alport syndrome, especially in glomeruli, and suggested that tauroursodeoxycholic acid might be useful for the early clinical treatment of Alport syndrome.
Project description:Ductal progenitor-like cells are a subpopulation of ductal cells in the adult human pancreas that have the potential to contribute to regenerative medicine. However, the microenvironmental cues that regulate their activation are poorly understood. Here, we establish a 3-dimensional suspension culture system containing six defined soluble factors in which primary human ductal and ductal progenitor-like cells can survive but do not proliferate. Expansion and polarization occur when cells are provided with a low concentration (5% v/v) of Matrigel, a sarcoma cell product enriched in many extracellular matrix (ECM) proteins. Screening of ECM proteins identified that collagen IV is capable of partially recapitulating the effects of Matrigel. Inhibition of integrin α1β1, a major collagen IV receptor, negates collagen IV- and Matrigel-stimulated effects. These results demonstrate that collagen IV is a key ECM protein that stimulates the expansion and polarization of human ductal and ductal progenitor-like cells via integrin α1β1 receptor signaling.
Project description:Ductal progenitor-like cells are a subpopulation of ductal cells in the adult human pancreas that have the potential to contribute to regenerative medicine. However, the microenvironmental cues that regulate their activation are poorly understood. Here, we establish a 3-dimensional suspension culture system containing six defined soluble factors in which primary human ductal and ductal progenitor-like cells can survive but do not proliferate. Expansion and polarization occur when cells are provided with a low concentration (5% v/v) of Matrigel, a sarcoma cell product enriched in many extracellular matrix (ECM) proteins. Screening of ECM proteins identified that collagen IV is capable of partially recapitulating the effects of Matrigel. Inhibition of integrin α1β1, a major collagen IV receptor, negates collagen IV- and Matrigel-stimulated effects. These results demonstrate that collagen IV is a key ECM protein that stimulates the expansion and polarization of human ductal and ductal progenitor-like cells via integrin α1β1 receptor signaling.
Project description:Transcriptional activity was identified in all categories of genes expressed by ADSC, including collagens, ECM and basement membrane constituents, adhesion molecules involved in cell-cell and cell-matrix interactions, and proteases involved in degradation of the ECM and their inhibitors. Importantly, it was observed that ADSC synthesize and secrete all three collagen VI chains, suggesting suitability of ADSC for collagen VI congenital muscular dytrophy treatment.
Project description:Alport syndrome (AS) is a genetic defect involving mutations of collagen IV α3, α4 or α5 genes, resulting in distinctive clinical features: kidney disease, hearing loss and eye abnormalities. Podocytes are responsible of production and correct assembly of the collagen IV isoforms, however, specific alterations of podocyte phenotype are currently scarce. We here generated immortalised AS urine-derived podocyte from three different patients. AS podocytes expressed a typical podocyte signature when compared to normal urine-derived podocytes, with comparable expression of podocyte markers. Each AS cell line showed a collagen IV profile that reflected the typical patient mutation. Furthermore, by RNA-sequencing 348 genes were found differentially expressed in Alport podocytes. Gene Ontology analysis underlined enrichment in genes involved in cell motility, adhesion, survival and angiogenesis. In parallel, AS podocyte motility was reduced. In conclusion, our data clearly indicate that AS podocytes display altered features connected but distinct from the collagen alterations.
Project description:Transcriptional activity was identified in all categories of genes expressed by ADSC, including collagens, ECM and basement membrane constituents, adhesion molecules involved in cell-cell and cell-matrix interactions, and proteases involved in degradation of the ECM and their inhibitors. Importantly, it was observed that ADSC synthesize and secrete all three collagen VI chains, suggesting suitability of ADSC for collagen VI congenital muscular dytrophy treatment. We developed a procedure for isolation of human stem cells from adipose layer of neonatal foreskin skin. The adipose-derived stem cells (ADSC) were examined for expression of extracellular matrix (ECM) and related genes using gene expression array analysis.
Project description:Type IV collagen is the main component of the basement membrane which gives strength to the blood-gas barrier. In avians the formation of the blood-gas barrier happens rapidly and before hatching. We have performed a microarray expression analysis in late chick lung development and found that COL4A1 and COL4A2 were among the most significantly upregulated genes during the formation of the avian blood-gas barrier. Our study showed that type IV collagen and therefore the basement membrane play fundamental roles in coordinating alveolar morphogenesis.
Project description:Type IV collagen is the main component of the basement membrane which gives strength to the blood-gas barrier. In avians the formation of the blood-gas barrier happens rapidly and before hatching. We have performed a microarray expression analysis in late chick lung development and found that COL4A1 and COL4A2 were among the most significantly upregulated genes during the formation of the avian blood-gas barrier. Our study showed that type IV collagen and therefore the basement membrane play fundamental roles in coordinating alveolar morphogenesis. Four developmental stages of chick lung maturation (E14, E15, E16, E18). Three biological replicates per time point.
Project description:Electrical and structural remodeling processes are contributors to the self-perpetuating nature of atrial fibrillation (AF). However, their correlation has not been clarified. In this study, human atrial tissues from the patients with rheumatic mitral valve disease in either sinus rhythm or persistent AF were analyzed using a combined transcriptomic and proteomic approach. An up-regulation in chloride intracellular channel (CLIC) 1, 4, 5 and a rise in type IV collagen were revealed. Combined with the results from immunohistochemistry and electron microscope analysis, the distribution of type IV collagen and effects of fibrosis on myocyte membrane indicated the possible interaction between CLIC and type IV collagen, confirmed by protein structure prediction and co-immunoprecipitation. These results indicate that CLICs play an important role in the development of atrial fibrillation and that CLICs and structural type IV collagen may interact on each other to promote the development of AF in rheumatic mitral valve disease.