Project description:We performed bulk RNA sequencing to characterize proximal tubular epithelial cells (PTECs) and PTECs that are positive for CD24 and CD133 (presumed to be scattered tubular cells (STCs)). We found an upregulation of many STC markers in our bulk RNA sequencing data and identified a pro-inflammatory and pro-fibrotic phenotype for STCs compared to PTECs. Many forms of metabolism were downregulated in the STCs compared to PTECs.
Project description:Fibroblasts can be directly reprogrammed to induced renal tubular epithelial cells (iRECs) using four transcription factors. These engineered cells may be used for disease modeling, cell replacement therapy or drug and toxicity testing. Direct reprogramming induces drastic changes in the transcriptional landscape, protein expression, morphological and functional properties of cells. However, how the metabolome is changed by reprogramming and to what degree it resembles the target cell type remains unknown. Using untargeted gas chromatography-mass spectrometry (GC-MS) and targeted liquid chromatography-MS, we characterized the metabolome of mouse embryonic fibroblasts (MEFs), iRECs, mIMCD-3 cells, and whole kidneys. Metabolic fingerprinting can distinguish each cell type reliably, revealing iRECs are most similar to mIMCD-3 cells and clearly separate from MEFs used for reprogramming. Treatment with the cytotoxic drug cisplatin induced typical changes in the metabolic profile of iRECs commonly occurring in acute renal injury. Interestingly, metabolites in the medium of iRECs, but not of mIMCD-3 cells or fibroblast could distinguish treated and non-treated cells by cluster analysis. In conclusion, direct reprogramming of fibroblasts into renal tubular epithelial cells strongly influences the metabolome of engineered cells, suggesting that metabolic profiling may aid in establishing iRECs as in vitro models for nephrotoxicity testing in the future.
Project description:Despite numerous studies reporting deregulated microRNA (miRNA) and gene expression patterns in clear cell renal cell carcinoma (ccRCC), no direct comparisons have been made to its presumed normal counterpart; the renal proximal epithelial tubular cells (PTEC). The aim of this study was to determine the miRNA expression profiles of ten clear cell renal cell carcinoma-derived cell lines and short-term cultures of PTEC, and to correlate these with their gene expression, and copy-number profiles. Using microarray-based methods, a significantly altered expression level in ccRCC cell lines was observed for 23 miRNAs and 1630 genes. The set of miRNAs with significantly decreased expression levels include all members of the miR-200 family known to be involved in the epithelial to mesenchymal transition (EMT) process. Expression levels of 13 of the 47 validated target genes for the downregulated miRNAs were increased more than two-fold. Our data reinforce the importance of the EMT process in the development of ccRCC. For mRNA expression data of these cell lines see GEO Series accession number GSE20491. MicroRNA profiling was performed on two proximal tubular epithelial cell samples (both cell samples were hybridized twice (biological duplicates)) and ten clear cell renal cell carcinoma- derived cell lines (one of which; RCC-JF in duplicate)
Project description:Shiga toxin type 2 (Stx2) from Escherichia coli is thought to be a main factor to casue renal dysfunction in Enterohemorrhagic E. coli (EHEC) infection. The renal dysfunction caused by the proximal tubular defects can be detected in the earlier EHEC infection. However, the precise information of gene expression from proximal tubular epithelial cells has yet to be clarified. We performed microarray experiments using Stx2-injected mouse kidney and Stx2-treated human renal proximal tubular epithelial cells (RPTEC), and extracted common genes that were differentially expressed.
Project description:Diabetic nephropathy is considered one of the most common microvascular complications of diabetes and the pathophysiology involves multiple factors. Progressive diabetic nephropathy is believed to be related to the structure and function of the tubular epithelial cells in the kidney. However, the role of lysine acetylation in lesions of the renal tubular epithelial cells arising from hyperglycemia is poorly understood. Consequently, in this study, we cultured mouse renal tubular epithelial cells in vitro under high glucose conditions and analyzed the acetylation levels of proteins by liquid chromatography-high-resolution mass spectrometry. We identified 48 upregulated proteins and downregulated 86 proteins. In addition, we identified 113 sites with higher acetylation levels and 374 sites with lower acetylation levels. Subcellular localization analysis showed that the majority of the acetylated proteins were located in the mitochondria (43.17%), nucleus (28.57%) and cytoplasm (16.19%). Enrichment analysis indicated that these acetylated proteins are primarily associated with oxidative phosphorylation, the citrate cycle (TCA cycle), metabolic pathways and carbon metabolism. In addition, we used the MCODE plug-in and the cytoHubba plug-in in Cytoscape software to analyze the PPI network and displayed the first four most compact MOCDEs and the top 10 hub genes from the differentially expressed proteins between global and acetylated proteomes. Finally, we extracted 37 conserved motifs from 4915 acetylated peptides. Collectively, this comprehensive analysis of the proteome reveals novel insights into the role of lysine acetylation in tubular epithelial cells and may make a valuable contribution towards the identification of the pathological mechanisms of diabetic nephropathy.
Project description:In order to study the effect of mesenchymal stem cells on miRNAs in renal tubular epithelial cells during renal fibrosis, and to find new treatment methods for renal fibrosis, we used TGF-β1 to stimulate mouse tubular epithelial cells, co-cultured with mesenchymal stem cells for 48 hours, and collected renal tubular epithelial cells .The renal tubular epithelial cells that were only stimulated by TGF-β1 were used as a control group. High-throughput miRNA sequencing was used to detect the increased and decreased miRNAs after co-culture.
Project description:NF-κB is a key regulator of innate and adaptive immunity and is implicated in the pathogenesis of acute kidney injury (AKI). The cell type-specific functions of NF-κB in the kidney are unknown; however, the pathway serves distinct functions in immune and tissue-parenchymal cells. We analyzed tubular epithelial-specific NF-κB signaling in a mouse model of ischemia-reperfusion injury (IRI)-induced AKI. NF-κB reporter activity and nuclear localization of phosphorylated NF-κB subunit p65 analyses in mice revealed widespread NF-κB activation in renal tubular epithelia and in interstitial cells following IRI that peaked at 2-3 days after injury. To genetically antagonize tubular epithelial NF-κB activity, we generated mice expressing the human NF-κB super-repressor IκBα∆N in renal proximal, distal, and collecting duct epithelial cells. These mice were protected from IRI-induced AKI, as indicated by improved renal function, reduced tubular apoptosis, and attenuated neutrophil and macrophage infiltration. Tubular NF-κB-dependent gene expression profiles revealed temporally distinct functional gene clusters for apoptosis, chemotaxis, and morphogenesis. Primary proximal tubular cells isolated from IκBα∆N-expressing mice exposed to hypoxia-mimetic agent cobalt chloride were protected from apoptosis and expressed reduced levels of chemokines. Our results indicate that postischemic NF-κB activation in renal-tubular epithelia aggravates tubular injury and exacerbates a maladaptive inflammatory response.