Project description:The expression of clock genes are co-regulated by BMAL1 and CLOCK in all tissue including kidney. Whether these clock-regualted genes can be affected by melatonin still unclaer. To further examine the possible mechanism and biological consequence, we depleted BMAL1 or CLOCK with small interfering RNA (siRNA) and treated cells with melatonin. Then, we used microarray analyses to identify clock genes regulated by melatonin in renal tubular epithelial cell.
Project description:Circadian rhythmicity in renal function suggests rhythmic adaptations in renal metabolism. To decipher the role of the circadian clock in renal metabolism, we studied diurnal changes in renal metabolic pathways using integrated transcriptomic, proteomic, and metabolomic analysis performed on control mice and mice with inducible deletion of the circadian clock regulator Bmal1 in the renal tubule (cKOt). With this unique resource, we demonstrated that ~30% RNAs, ~20% proteins and ~20% metabolites are rhythmic in kidneys of control mice. Several key metabolic pathways including NAD+ biosynthesis, fatty acid transport, carnitine shuttle, and b-oxidation displayed impairments in kidneys of cKOt, resulting in a perturbed mitochondrial activity. Carnitine reabsorption from the primary urine was one of the most impacted processes with a ~50% reduction in plasma carnitine levels and a parallel systemic decrease in tissues carnitine content. This suggests that the circadian clock in the renal tubule controls both kidney and systemic physiology.
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: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:Circadian rhythmicity in renal function suggests a requirement for circadian adaptations in renal metabolism. We studied circadian changes in renal metabolic pathways using integrated transcriptomic, proteomic and metabolomic analysis performed on control mice and mice deficient in the circadian clock gene Bmal1 in the renal tubule (cKOt mice). Proteins were extracted from whole kidneys of 60 mice. Of these, 30 were conditional knockouts of Arntl (Bmal1) and 30 were of control genotype. They were housed under 12-hours light/12-hours dark cycles and were sacrificed at six different time points: zeitgeber time ZT 0, ZT 4, ZT 8, ZT 12, ZT 16, ZT 20 ( ZT 0 being the time of light on and ZT 12 the time of light off). Five replicates per genotype and time point were analysed.
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: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:Kidney damage involves the progressive and inexorable destruction of tubular and glomerular system. However, it is known that the patients survive AKI often recover renal structure and function. Correspondingly, previous studies demonstrated tubular regeneration in mice after massive kidney injury and linked mouse Sox9+ renal progenitor cells to this process. Here we show that renal progenitor cells can be cloned from renal needle biopsy sample of CKD patients. Progenitor cells can readily assembly into “kidney organoids” expressing proximal/distal tubular cell markers in 3D culture.