Project description:Parietal epithelial cells (PECs) are part of renal progenitor cells with similarities to bone marrow stem cell niche. In focal segmental glomerulosclerosis (FSGS) PECs become activated and contribute to extracellular matrix deposition. Colony stimulating factor-1 (CSF-1), a hematopoietic growth factor, acts via its specific receptor, CSF-1R, and has been implicated in several glomerular diseases, although its role on PEC activation is unknown. We found that CSF-1R was upregulated in PECs and podocytes from human biopsies with FSGS. Through in vitro studies, we demonstrated that PECs constitutively express CSF-1R. Incubation with CSF-1 induced CSF-1R upregulation and significant transcriptional regulation of genes involved in pathways associated with PEC activation. Specifically, CSF-1/CSF-1R activated the ERK1/2 pathway and upregulated CD44 in PECs, while both ERK and CSF-1R inhibitors reduced CD44 expression. Our functional studies showed that CSF-1 induced PEC proliferation and migration, while reducing the differentiation of PECs into podocytes. These results were validated in the Adriamycin-induced FSGS experimental model. Importantly, treatment with either the CSF-1R-specific inhibitor GW2580 or Ki20227 provided a robust therapeutic effect. In conclusion, we provide the first evidence of the role of the CSF-1/CSF-1R pathway in PEC activation in FSGS, paving the way for future clinical studies investigating the therapeutic effect of CSF-1R inhibitors on FSGS in humans.
Project description:To search for biomarkers to differentiate Adult-Onset Steroid Sensitive focal segmental glomerulosclerosis (FSGS) and minimal change disease (MCD). Compared the profiles of glomerular transcriptomes between patients with FSGS and patients with MCD using microarray analysis. This dataset is part of the TransQST collection.
Project description:Parietal epithelial cells (PECs) are crucially involved in the pathogenesis of rapidly progressive glomerulonephritis (RPGN) as well as in focal and segmental glomerulosclerosis (FSGS). In this study, transgenic mouse lines were used to isolate pure, genetically tagged primary cultures of PECs or podocytes using FACsorting. By this approach, the morphology of primary glomerular epithelial cells in culture could be resolved: Primary podocytes formed either large cells with intracytoplasmatic extensions or smaller spindle shaped cells, depending on specific culture conditions. Primary PECs were small and exhibited a spindle-shaped or polygonal morphology. In the very early phases of primary culture, rapid changes in gene expression (e.g. of WT-1 and Pax-2) were observed. However, after prolonged culture primary PECs and podocytes still segregated clearly in a transcriptome analysis - demonstrating that the origin of primary cell cultures is important. Of the classical markers, synaptopodin and podoplanin expression were differentially regulated the most in primary PEC and podocyte cultures. However, no expression of any endogenous gene allowed to differentiate between the two cell types in culture. Finally, we show that the transcription factor WT1 is also expressed by PECs. In summary, genetic tagging of PECs and podocytes is a novel and necessary tool to derive pure primary cultures with proven origin. These cultures will be a powerful tool for the emerging field of parietal epithelial cell biology. Total RNA for genechip analysis was derived from: 1) Primary parietal cells isolated by FACS sorting of glomeruli cultivated in 1a) RPMI media 1b) EGM-MV media 2) Primary podocyte cells isolated by FACS sorting of glomeruli cultivated in 2a) RPMI media 2b) EGM-MV media
Project description:Transcriptome comparison of glomeruli from kidneys with focal segmental glomerulosclerosis (FSGS) and glomeruli from the unaffected portion of tumor nephrectomies. High-density Affymetrix Human Transcriptome Arrays (HTA) 2.0 were used for the gene expression analysis.
Project description:Parietal epithelial cells (PECs) are crucially involved in the pathogenesis of rapidly progressive glomerulonephritis (RPGN) as well as in focal and segmental glomerulosclerosis (FSGS). In this study, transgenic mouse lines were used to isolate pure, genetically tagged primary cultures of PECs or podocytes using FACsorting. By this approach, the morphology of primary glomerular epithelial cells in culture could be resolved: Primary podocytes formed either large cells with intracytoplasmatic extensions or smaller spindle shaped cells, depending on specific culture conditions. Primary PECs were small and exhibited a spindle-shaped or polygonal morphology. In the very early phases of primary culture, rapid changes in gene expression (e.g. of WT-1 and Pax-2) were observed. However, after prolonged culture primary PECs and podocytes still segregated clearly in a transcriptome analysis - demonstrating that the origin of primary cell cultures is important. Of the classical markers, synaptopodin and podoplanin expression were differentially regulated the most in primary PEC and podocyte cultures. However, no expression of any endogenous gene allowed to differentiate between the two cell types in culture. Finally, we show that the transcription factor WT1 is also expressed by PECs. In summary, genetic tagging of PECs and podocytes is a novel and necessary tool to derive pure primary cultures with proven origin. These cultures will be a powerful tool for the emerging field of parietal epithelial cell biology.
Project description:Transcriptome comparison of tubular tissues from kidneys with focal segmental glomerulosclerosis (FSGS) and tubular tissues from the unaffected portion of tumor nephrectomies. High-density Affymetrix Human Transcriptome Arrays (HTA) 2.0 were used for the gene expression analysis.
Project description:Transcriptome comparison of tubulointerstitial tissues from kidneys with focal segmental glomerulosclerosis (FSGS) and tubulointerstitial tissues from the unaffected portion of surgical nephrectomies. High-density Affymetrix Human Transcriptome Arrays (HTA) 2.0 were used for the gene expression analysis.