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: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:Podocyte effacement and loss characterizes glomerulopathies such as diabetic nephropathy, lupus, and glomerular toxicity. Human primary podocyte-like epithelial cells cultured from urine (ECU) were characterized as a window to understand podocyte regeneration in these glomerulopathies. Cytokines TNF, and VEGF stimulated regrowth, whereas FGF-1 and IL1 inhibited growth, consistent with other podocyte or parietal epithelial cell models. Review of published micrographs indicated that podocyte foot processes in rodent kidneys interdigitated exclusively with foot processes from other cells, suggesting podocytes practice self-avoidance. In culture, ECU avoided close interactions with other cells arising from the same clone, until enough cells grew for the culture to become confluent. In contrast, ECU derived from multiple clones associated actively to form contiguous monolayers. Gene expression profiling of eight clonal ECU colonies using RNA sequencing revealed that each colony expressed a highly variable profile of the 53 Protocadherin genes. Variable combinations of the 53 Protocadherin PCDHA-, PCDHB-, and PCDHG- gene products are known to act homophilically to direct self-avoidance interactions in human neurons, so PCDH- genes are postulated to govern self-avoidance similarly in podocytes. Such protocadherin profiles could be considered cell names. Transcriptional profiles of ECUs suggest they may represent intermediate stages of Parietal Epithelial Cells (PECs) differentiating into podocytes. They further suggest that each podocyte practices self-avoidance, interdigitating selectively with other cells in the glomerulus. To enable further investigation of multi-clonal podocyte interactions, five podocyte clones were immortalized using temperature-sensitive SV40 Large T antigen. These results suggest that non-self interdigitation of new podocytes with remnant podocytes may facilitate replacement of dying podocytes and re-establishment of a functional filtration barrier.
Project description:Podocytes, highly differentiated glomerular epithelial cells, are essential for the maintenance of glomerular filtration barrier. Podocyte dysfunction in podocytes is a major determinant of proteinuric kidney disease. By RNA sequencing analysis in ADR-treated podocytes with or without MYDGF overexpression, we observed the significant changes of genes important in regulating cell cycle in podocytes with ADR treatment.
Project description:We generated a single-cell RNA sequencing (scRNAseq) dataset of primary cultures of human glomerular parietal epithelial cells. Comparing this dataset with an already available dataset obtained by scRNAseq of human renal progenitor cells (GSE137620), we identified an immature PEC subset characterized by the expression of stem cell markers and stratifin (SFN). Moreover, we analyzed the effect of treatment with the HDAC inhibitor panobinostat on PEC transcriptome demonstrating the upregulation of podocyte-specific markers in different PEC subsets including the stratifin-expressing subset.
Project description:The specialized glomerular epithelial cell (podocyte) of the kidney is a complex cell that is often damaged in glomerular diseases. Study of this cell type is facilitated by an in vitro system of propagation of conditionally immortalized podocytes. Here, genes that are differentially expressed in this in vitro model of podocyte differentiation are evaluated. Conditionally immortalized undifferentiated mouse podocytes were cultured under permissive conditions at 33*C. Podocytes that were differentiated at the non-permissive conditions at 37*C were used for comparison.
Project description:Podocytes, highly differentiated glomerular epithelial cells, are essential for the maintenance of glomerular filtration barrier. Lipid accumulation in podocytes is a major determinant of proteinuric kidney disease. By RNA-sequencing analysis, we observed the significant changes of genes important in regulating cellular lipid homeostasis in podocytes with HG treatment. We generated two mouse podocyte cell lines stably transduced with either a sh-NC lentiviral construct or a shRNA lentiviral construct designed to target JAML RNA to investigate the consequences on the gene expression profile of JAML knockdown in mouse podocytes.
Project description:PURPOSE: To provide a detailed gene expression profile of the normal postnatal mouse cornea. METHODS: Serial analysis of gene expression (SAGE) was performed on postnatal day (PN)9 and adult mouse (6 week) total corneas. The expression of selected genes was analyzed by in situ hybridization. RESULTS: A total of 64,272 PN9 and 62,206 adult tags were sequenced. Mouse corneal transcriptomes are composed of at least 19,544 and 18,509 unique mRNAs, respectively. One third of the unique tags were expressed at both stages, whereas a third was identified exclusively in PN9 or adult corneas. Three hundred thirty-four PN9 and 339 adult tags were enriched more than fivefold over other published nonocular libraries. Abundant transcripts were associated with metabolic functions, redox activities, and barrier integrity. Three members of the Ly-6/uPAR family whose functions are unknown in the cornea constitute more than 1% of the total mRNA. Aquaporin 5, epithelial membrane protein and glutathione-S-transferase (GST) omega-1, and GST alpha-4 mRNAs were preferentially expressed in distinct corneal epithelial layers, providing new markers for stratification. More than 200 tags were differentially expressed, of which 25 mediate transcription. CONCLUSIONS: In addition to providing a detailed profile of expressed genes in the PN9 and mature mouse cornea, the present SAGE data demonstrate dynamic changes in gene expression after eye opening and provide new probes for exploring corneal epithelial cell stratification, development, and function and for exploring the intricate relationship between programmed and environmentally induced gene expression in the cornea. Keywords: other