Project description:Renal tubular epithelial cells (TECs) are critical mediators of renal fibrogenesis. Telomere dysfunction has been associated with renal injury and fibrosis. However, the role of telomere dysfunction specifically in TECs in the onset and progression of renal fibrosis remains poorly understood. To investigate the impact of telomere dysfunction on renal injury and fibrosis, we generated mice depleted for the shelterin component TRF1 specifically in TECs. Genetic ablation of Trf1 caused decline in renal function, tubular injury and tubulointerstitial fibrosis eight weeks after TRF1 depletion, concomitant with excessive accumulation of extracellular matrix (ECM), cell cycle arrest at G2/M phase, and telomeric damage. Trf1Δ/Δ mice activated regenerative repair mechanism, increasing the risk of of chronic kidney disease (CKD) progression following acute kidney injury (AKI), supporting proliferation-mediated telomere shortening in tubular cells. Mechanistically, Trf1 deletion upregulated Ras–Raf–Mek–Erk, PI3k/Akt/mTOR and p38 pathways. At humane endpoint, Trf1Δ/Δ mice displayed elevated urinary albumin-to-creatinine ratio (uACR), associated with augmented interstitial fibrosis and tubular atrophy eventually leading to CKD. In folic acid (FA)-induced nephropathy, depletion of Trf1 in TECs mitigated the fibrogenic phenotype of CKD. Collectively, our study underlies the important role of TECs in the development and progression of renal fibrosis and CKD associated to dysfunctional telomeres.
Project description:Aged-related kidney impairment that involves tubular epithelial cell senescence and renal fibrosis become a severe threaten for worldwide public health. m6A-mRNA epitranscriptomic microarray was performed to reveal the targeted genes with abnormal m6A modification in aged human kidney tissues.
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:Sepsis is a severe and dysregulated inflammatory disease that often precedes the development of acute kidney injury (AKI) with consequent worsening outcome. The main characteristics of sepsis-induced AKI include endothelial cell (EC) dysfunction, infiltration of inflammatory cells, glomerular thrombosis, and renal tubular epithelial cells (RTEC) injury. Numerous studies have demonstrated that mammalian target of rapamycin (mTOR) activation has been implicated in the initiation and progression of renal injury in course of sepsis. However, little is known, about the molecular basis of mTOR role in EC and RTEC dysfunction. Here, we evaluate whether mTOR inhibition by Rapamycin (Rp) as potential strategy to ameliorate renal function and dissected the molecular mechanisms involved. In a mouse model of lipopolysaccharide (LPS)-induced AKI , LPS injection led to a time-dependent increase of serum creatinine and significant morphological changes in renal parenchyma associated with increased collagen deposits and endothelial dysfunction. Interestingly, Rp treatment significantly decreased creatine levels and preserved renal parenchyma, counteracting Endothelial-to mesenchymal transition (EndMT) process and early fibrosis through the inhibition of ERK pathway. Next, we examined the effects of LPS-TLR4 interaction in RTECs. Through a whole-genome DNA methylation analysis in cultured RTEC, we found that LPS induced aberrant methylation, particularly in regions involved in premature aging. The most represented genes were CD39 and WFS1. LPS stimulation of RTEC led to up-regulation of SA-β Gal and cell cycle arrest markers such as p21. In accordance, in endotoxemic mice, we found a decreased expression of CD39 concurrent with Klotho down-regulation. Administration of Rp exerted anti-aging effects in endotoxemic mice, preserving CD39 and Klotho expression. In conclusion, we demonstrated that mTOR inhibition could offer novel strategies to protect endothelial and tubular compartment from accelerated aging and fibrosis thus counteracting the progression to chronic kidney disease.
Project description:The role of endothelial dysfunction in tubulointerstitial fibrosis associated with chronic kidney disease (CKD) is not well understood. In this study, we demonstrate that the activation of the endothelial tyrosine kinase TIE2 alleviates renal pathology in experimental CKD in mice. TIE2 activation was achieved using a human angiopoietin-2 (ANGPT2)-binding and TIE2-activating antibody (ABTAA), or through adult-induced endothelial-specific knockout of the vascular endothelial protein tyrosine phosphatase gene (Veptp). Both methods significantly protected CKD mice from endothelial dysfunction, peritubular capillary loss, tubular epithelial injury, and tubulointerstitial fibrosis. Conversely, silencing TIE2 through adult-induced endothelial-specific knockout of the Tie2 gene exacerbated CKD pathology. Additionally, we found that endothelial dysfunction promotes renal fibrosis not through endothelial-to-mesenchymal transition as previously expected, but by inducing the expression of pro-fibrotic PDGFB in tubular epithelial cells, a process that is inhibited by TIE2 activation. Our findings suggest that TIE2 activation via ABTAA warrants investigation in human CKD, where there is a significant unmet medical need.
Project description:The circadian clock has been found to be associated with various diseases. We showed that 5/6 nephrectomy (5/6Nx) Clk/Clk mice, which show mutation in the gene encoding circadian locomotor output cycles (Clock) do not show aggravation of renal fibrosis because transforming growth factor-1 (Tgf-1) expression is not increased. In wild-type 5/6Nx kidneys, we found that retinoid, a metabolite of retinol, led to alteration of the expresion 24-h rhythm of Clock expression. Renal Tgf- 1 expression is activated by Clock and further aggravates renal dysfunction by causing fibrosis. We also showed that, in 5/6Nx mice fed a retinol-free diet, renal fibrosis and apoptosis are reduced, leading to a marked improvement in serum creatinine levels. Moreover, our study identified hepatic Cyp3a11 and Cyp26a1 as key retinol metabolism-related genes whose expression decreased in 5/6Nx mice. Our data indicated that the negative chain reaction of metabolic clock alteration in between the kidney and liver aggravates renal dysfunction.
Project description:A Gene Expression Signature that Predicts the Future Onset of Drug-Induced Renal Tubular Toxicity These data support the publication titled "A Gene Expression Signature that Predicts the Future Onset of Drug-Induced Renal Tubular Toxicity" Copyright (c) 2005 by Iconix Pharmaceuticals, Inc. Guidelines for commercial use: http://www.iconixbiosciences.com/guidelineCommUse.pdf replicated drug treatments with controls
Project description:Renal fibrosis is the common pathological feature of CKD and plays a key role in the progression of CKD to ESRD. However, the underlying mechanisms of renal fibrosis initiation and progression remains unclear. FAM3D belongs to FAM3 gene family and is associate with nutrient regulation and inflammation. In this study, we found that FAM3D was de novo expressed in tubules during CKD and positively correlated with fibrogenesis. Knockout of tubular FAM3D effectively improved UIRI- or UUO-induced renal fibrosis. Mechanistically, FAM3D depletion suppressed NF-κB activation in epithelial cells via FPRs/MAPK pathway and then alleviated cell pyroptosis. Furthermore, blockade of FPR1/2 prevented renal inflammation, tubular cell pyroptosis, and fibrosis development. Our findings provided the first evidence for the critical role of FAM3D in renal fibrosis progression.
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: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.