Project description:Purpose: Next-generation sequencing (NGS) was used to define the transcriptome of native mouse podocytes and non-podocytes glomerular cells as part of a project aiming to define the molecular fingerprint of mouse podocytes. Method: Glomeruli from 29 Gt(ROSA)26Sortm4(ACTB-tdTomato,-EGFP)Luo/J x hNPHS2Cre mice at the age of 10 weeks were purified and a single cell solution was prepared to seperate GFP-expressing (podocytes) and GFP-negative (non-podocytes glomerular cells) cells by FACS sorting. RNA was extracted and prepared for further analysis using directional, polyA+ library preparation. An Illumina HiSeq2500 was used for a paired-end sequencing of 100 cycles . Salmon and Sleuth were used for downstream analysis. Results: A total of 100 Million reads each from podocytes and non-podocytes glomerular cells could be used for further analysis.
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:The effect of miRNA delivery from glomerular endothelial cells (GEnCs) to podocytes in vitro was examined by miRNA epression in podocytes untreated and treated with extracellular vesicles from GEnCs under varied activation conditions.
Project description:The effect of miRNA delivery from glomerular endothelial cells (GEnCs) to podocytes in vitro was examined by mRNA epression in podocytes untreated and treated with extracellular vesicles from GEnCs under varied activation conditions.
Project description:The glomerular filtration barrier prevents large serum proteins from being lost into the urine. It is not known, however, why the filter does not routinely clog with large proteins that enter the glomerular basement membrane (GBM). Here we provide evidence that an active transport mechanism exists to remove immunoglobulins that accumulate at the filtration barrier. We found that FcRn, an IgG and albumin transport receptor, is expressed in podocytes and functions to internalize IgG from the GBM. Mice lacking FcRn accumulated IgG in the GBM as they aged and tracer studies showed delayed clearance of IgG from the kidneys of FcRn deficient mice. Supporting a role for this pathway in disease, saturating the clearance mechanism potentiated the pathogenicity of nephrotoxic sera. These studies support the idea that podocytes play an active role in removing proteins from the GBM and suggest that genetic or acquired impairment of the clearance machinery is likely to be a common mechanism promoting glomerular diseases. Keywords: Unique cell type expression analysis
Project description:Indoxyl sulfate (IS) is a uremic toxin and ligand of the aryl-hydrocarbon receptor (Ahr), a transcriptional regulator. Elevated serum IS may contribute to the progression of kidney disease. Therefore, we assessed mouse podocyte damage mediated by IS. Ahr was predominantly localized to the podocyte nucleus in vivo and in vitro. In isolated glomeruli, IS-exposure for 2 – 24 h induced Cyp1a1 expression, the most sensitive biomarker of Ahr activation. Mice exposed to IS for 4–8 weeks exhibited microalbuminuria, and mild glomerular injury characterized by ischemic changes, partial podocyte foot process effacement, as well as vascular and tubulointerstitial damage. Chronically IS-exposed kidneys exhibited decreased mRNA, decreased protein levels, and altered staining patterns for podocin, synaptopodin, and non-muscle myosin IIA (Myh9). Immortalized podocytes, upon differentiation, exhibited Ahr nuclear translocation beginning 30 min after 1 mM IS-exposure. At 2 h, there was a dose-dependent decrease in podocyte mRNA expression of WT1, Podxl, Snypo, Myh9, Actn4, and Cd2ap. After 24 h of exposure to IS, podocytes were smaller, had fewer actin/Myh9 fibers, and decreased viability. Ahr-RNAi decreased mRNA expression of podocyte-specific proteins and inhibited Cyp1a1 induction by IS-exposure. Combinations of Ahr-RNAi and IS-exposure further decreased Myh9 expression. In immortalized human podocytes, IS treatment caused cell injury, decreased mRNA expression of podocyte-specific proteins, integrins, collagens, cytoskeletal proteins, and bone morphogenetic proteins, and increased cytokine and chemokine expression. Thus, chronic IS-exposure causes glomerular damage by activating Ahr, altering podocyte function, differentiation, and morphology, and inducing a pro-inflammatory phenotype. Podocyte cells treated with Indoxyl sulfate, a uremic toxin and aryl-hydrocarbon receptor ligand, mediates progressive glomerular disease by damaging podocytes Human podocyte cell line treated with or without 3-Indoxyl sulfate (1mM/0.1%DMSO) in three replications
Project description:The glomerular filtration barrier prevents large serum proteins from being lost into the urine. It is not known, however, why the filter does not routinely clog with large proteins that enter the glomerular basement membrane (GBM). Here we provide evidence that an active transport mechanism exists to remove immunoglobulins that accumulate at the filtration barrier. We found that FcRn, an IgG and albumin transport receptor, is expressed in podocytes and functions to internalize IgG from the GBM. Mice lacking FcRn accumulated IgG in the GBM as they aged and tracer studies showed delayed clearance of IgG from the kidneys of FcRn deficient mice. Supporting a role for this pathway in disease, saturating the clearance mechanism potentiated the pathogenicity of nephrotoxic sera. These studies support the idea that podocytes play an active role in removing proteins from the GBM and suggest that genetic or acquired impairment of the clearance machinery is likely to be a common mechanism promoting glomerular diseases. Experiment Overall Design: Total RNA for genechip analysis was derived from two sources: Experiment Overall Design: 1) Primary mouse podocytes isolated by FACS sorting of collagenase digested glomeruli Experiment Overall Design: 2) In vitro differentiated conditionally immortalized mouse podocyte cell line. Experiment Overall Design: After obtaining genechip data, the expression of various IgG and albumin receptors was queried in the genechip data and then confirmed by RT-PCR.
Project description:Transcriptome analysis of growth hormone dependant genes in glomerular podocytes Differentiated human glomerular podocytes in culture exposed to growth hormone for 0 min, 2 min, 5 min, 15 min, and 30 min. Total RNA is extracted and subjected to microarray analysis.
Project description:Indoxyl sulfate (IS) is a uremic toxin and ligand of the aryl-hydrocarbon receptor (Ahr), a transcriptional regulator. Elevated serum IS may contribute to the progression of kidney disease. Therefore, we assessed mouse podocyte damage mediated by IS. Ahr was predominantly localized to the podocyte nucleus in vivo and in vitro. In isolated glomeruli, IS-exposure for 2 – 24 h induced Cyp1a1 expression, the most sensitive biomarker of Ahr activation. Mice exposed to IS for 4–8 weeks exhibited microalbuminuria, and mild glomerular injury characterized by ischemic changes, partial podocyte foot process effacement, as well as vascular and tubulointerstitial damage. Chronically IS-exposed kidneys exhibited decreased mRNA, decreased protein levels, and altered staining patterns for podocin, synaptopodin, and non-muscle myosin IIA (Myh9). Immortalized podocytes, upon differentiation, exhibited Ahr nuclear translocation beginning 30 min after 1 mM IS-exposure. At 2 h, there was a dose-dependent decrease in podocyte mRNA expression of WT1, Podxl, Snypo, Myh9, Actn4, and Cd2ap. After 24 h of exposure to IS, podocytes were smaller, had fewer actin/Myh9 fibers, and decreased viability. Ahr-RNAi decreased mRNA expression of podocyte-specific proteins and inhibited Cyp1a1 induction by IS-exposure. Combinations of Ahr-RNAi and IS-exposure further decreased Myh9 expression. In immortalized human podocytes, IS treatment caused cell injury, decreased mRNA expression of podocyte-specific proteins, integrins, collagens, cytoskeletal proteins, and bone morphogenetic proteins, and increased cytokine and chemokine expression. Thus, chronic IS-exposure causes glomerular damage by activating Ahr, altering podocyte function, differentiation, and morphology, and inducing a pro-inflammatory phenotype. Podocyte cells treated with Indoxyl sulfate, a uremic toxin and aryl-hydrocarbon receptor ligand, mediates progressive glomerular disease by damaging podocytes