Project description:Podocyte injury is a key event for progressive renal failure. We previously established a mouse model of inducible podocyte injury (NEP25) and demonstrated relentless progression of glomerular injury toward sclerosis. To further investigate molecular events, we performed polysome analysis of intact and injured podocytes utilizing the NEP25 and RiboTag transgenic mice. We show here the expression profiling of normal podocytes and podocytes injured by immunotoxin.
Project description:We compared mRNA profiles of isolated glomeruli versus sorted podocytes between diabetic and control mice. IRG mice crossed with eNOS-/- mice were further bred with podocin-rTTA and TetON-Cre mice to permanently label podocytes before the diabetic injury. Diabetes was induced by injection of streptozotocin. mRNA profiles of isolated glomeruli and sorted podocytes from diabetic and control mice at 10 weeks after induction of diabetes were examined. Consistent with the previous reports, expression of podocyte-specific markers in the glomeruli were down-regulated in the diabetic mice compared to controls. However, these differences disappeared when mRNA levels were corrected for podocyte number per glomerulus. Interestingly, the expression of these markers was not altered in sorted podocytes from diabetic mice, suggesting that the reduced expression of podocyte markers in isolated glomeruli is likely a secondary effect of reduced podocyte number, rather than the loss of differentiation markers. Analysis of the differentially expressed genes in diabetic mice also revealed distinct up-regulated pathways in the glomeruli (mitochondrial function and oxidative stress) and podocytes (actin organization). In conclusion, our data suggest that podocyte-specific gene expression in transcriptome obtained from the whole glomeruli may not represent those of podocytes in the diabetic kidney. We compared mRNA profiles of isolated glomeruli versus sorted podocytes between diabetic and control mice.
Project description:We analyzed the proteome of mouse FACS-sorted podocytes. We compared podocytes ("green cells") with non-podocyte ("red cells") cells of the glomerulus.
Project description:Purpose: Next-generation sequencing (NGS) was used to identify cellular pathways and genes through systems-based analysis. The goals of this study are to identify NGS-derived transcriptome profiling (RNA-seq) in control (untreated) and Injured (PAN and Adriamycin) podocyte. These high throughput data were further validated through qRT–PCR methods to confirm the cellular pathways and genes affected due to the podocyte injury. Methods: Human podocytes were differentiated for 14 days by thermoswitching from 33⁰C to 37⁰C and removal of growth factors, insulin-transferrin-selenium from the medium. These podocytes were incubated 4hour in serum free RPMI medium and injury was induced by using PAN (100μg/ml) and Adriamycin (0.25μg/ml) treatment for 48 hours.Further, podocytes were processed for RNA isolation and submitted to Medical University of South Carolina Sequencing Core facility for RNA-Seq. All the experiments were performed in triplicates. Conclusions: Our study is first to describe the detailed analysis of PAN and Adriamycin induced podocyte transcriptomes using the RNA-seq technology. A comparative analysis of the differential expression profile was obtained between control vs PAN injured podocytes, and control vs Adriamycin injured podocytes. Complex genetic network and genes effected due to the injury will provide a platform to define biological pathways participate during podocytes injury process.
Project description:The thorough characterization of the transcriptome of endogenous podocytes has been hampered by low yields of cell isolation procedures. Here we introduce a double fluorescent reporter mouse model combined with an optimized bead perfusion protocol and efficient single cell dissociation yielding more than 500,000 podocytes per mouse allowing for global, unbiased downstream applications. Combining mRNA transcriptional profiling revealed programs of highly specific gene regulation tightly controlling cytoskeleton, cell differentiation, endosomal transport and peroxisome function in podocytes. Strikingly, the analyses further predict that these podocyte-specific gene regulatory networks are accompanied by alternative splicing of respective genes. In summary, the presented M-bM-^@M-^XomicsM-bM-^@M-^Y approach will facilitate the discovery and integration of novel gene, protein and organelle regulatory networks that deepen our systematic understanding of podocyte biology. To compare gene expression of glomerulus podocytes versus non-podocytes 5 replicates of 4 pooled mice were used. Data were normalized by robust multi-chip analysis. Exon expression values were summarised to the core meta probesets, as defined by Affymetrix, using the oligo library from R.
Project description:Podocytes form filtration barrier through foot process around glomerualar basement membrane and selectively permit permeability of molecular smaller than albumin. Diabetes can cause podocyte pathological changes leading to high urine albumin level. Diabetic mouse model OVE26 has extremly high urine albumin and previously studies indicated its podocyte damaged. Here we try to find the key genes change in OVE26 diabetic mouse model podocyte by microarray assay while normal FVB mouse podocyte set as control. Podocyte eGFP transgenic mice were made on FVB background and crossbred to OVE26 diabetic model. Glomeruli isolated from OVE-GFP mice were digested by trypsin into signal cell. Podocytes with GFP were sorting out by FACS.
Project description:Podocytes form filtration barrier through foot process around glomerualar basement membrane and selectively permit permeability of molecular smaller than albumin. Diabetes can cause podocyte pathological changes leading to high urine albumin level. Diabetic mouse model OVE26 has extremly high urine albumin and previously studies indicated its podocyte damaged. Here we try to find the key genes change in OVE26 diabetic mouse model podocyte by microarray assay while normal FVB mouse podocyte set as control.
Project description:We compared mRNA profiles of isolated glomeruli versus sorted podocytes between diabetic and control mice. IRG mice crossed with eNOS-/- mice were further bred with podocin-rTTA and TetON-Cre mice to permanently label podocytes before the diabetic injury. Diabetes was induced by injection of streptozotocin. mRNA profiles of isolated glomeruli and sorted podocytes from diabetic and control mice at 10 weeks after induction of diabetes were examined. Consistent with the previous reports, expression of podocyte-specific markers in the glomeruli were down-regulated in the diabetic mice compared to controls. However, these differences disappeared when mRNA levels were corrected for podocyte number per glomerulus. Interestingly, the expression of these markers was not altered in sorted podocytes from diabetic mice, suggesting that the reduced expression of podocyte markers in isolated glomeruli is likely a secondary effect of reduced podocyte number, rather than the loss of differentiation markers. Analysis of the differentially expressed genes in diabetic mice also revealed distinct up-regulated pathways in the glomeruli (mitochondrial function and oxidative stress) and podocytes (actin organization). In conclusion, our data suggest that podocyte-specific gene expression in transcriptome obtained from the whole glomeruli may not represent those of podocytes in the diabetic kidney.
Project description:The progression of proteinuric kidney disease is associated with podocyte loss but the mechanisms remain unclear. Podocytes reenter the cell cycle to repair damaged ds DNA breaks. However, unsuccessful repair results in podocytes crossing the G1/S checkpoint and undergoes abortive cytokinesis. In this study, we identified Pfn1 as a major contributor in maintaining glomerular integrity and its loss in mice results in severe proteinuria, and kidney failure due to podocyte mitotic catastrophe, characterized by abundant multinucleated cells. Reentry of podocytes were identified by using FUCCI-2aR mice, accompanying the alteration of cell-cycle associated proteins, such as P21, P53, Cyclin B, and Cyclin D. Podocyte-specific translating ribosome affinity purification (TRAP) and RNAseq revealed a reduction of Ribosomal RNA-processing protein 8 (Rrp8) and re-expression of Rrp8 partially rescued the in-vitro phenotype. Clinical analysis of patients with proteinuric kidney disease demonstrated multinucleated podocytes and reduced podocyte profilin1 in kidney tissue. These results suggest that profilin is indispensible in regulating podocyte cell cycle and its disruption contributes to podocyte loss through mitotic catastrophe.