SOX9 regulates NAV3 to control cytoskeletal and mechanical properties of profibrotic myofibroblasts during renal fibrosis
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ABSTRACT: Fibrosis is a common pathway in the progression of chronic kidney disease. Extracellular matrix deposition from myofibroblasts causes scarring, tissue stiffness and organ failure. This submission studies the role of Sex determining region Y-box 9 (SOX9) in kidney fibrosis.
Project description:Tissue inhibitors of metalloproteinases (TIMP) are endogenous inhibitors of matrix metalloproteinases (MMP). While TIMP2 and TIMP3 inhibit MMPs, TIMP3 also inhibits activation of pro-MMP2 whereas TIMP2 promotes it. Here we assessed the differential role of TIMP2 and TIMP3 in renal injury using the unilateral ureteral obstruction model. Gene microarray assay showed that post-obstruction, the lack of TIMP3 had a greater impact on gene expression of intermediate, late injury- and repair-induced transcripts, kidney selective transcripts and solute carriers. Renal injury in TIMP3-/-, but not in TIMP2-/- mice increased expression of collagen type I/III, connective tissue growth factor, transforming growth factor-β and the downstream Smad2/3 pathway. Interestingly, ureteral obstruction markedly increased MMP2 activation in the kidneys of TIMP3-/- mice which was completely blocked in the kidneys of TIMP2-/- mice. These changes are consistent with enhanced renal tubulointerstitial fibrosis in TIMP3-/- and its reduction in TIMP2-/- mice. The activity of tumor necrosis factor-α converting enzyme, caspase-3 and mitogen activated kinases were elevated in the kidneys of TIMP3-/- but not TIMP2-/- mice, suggesting enhanced activation of apoptotic and pathological signaling pathways only in the obstructed kidney of TIMP3-/- mice. Thus, TIMP2 and TIMP3 play differential and contrasting roles in renal injury, TIMP3 protects from damage whereas TIMP2 promotes injury through MMP2 activation. Kidneys from the wild type (WT), TIMP2-/- and TIMP3-/- mice undergoing sham or unilateral ureteral obstruction (UUO) procedures
Project description:In this study, we employed high-throughput RNA sequencing (RNA-Seq) to identify the Smad3-dependent lncRNAs related to renal inflammation and fibrosis in Smad3 knockout (KO) mouse models of unilateral ureteral obstructive nephropathy (UUO) and immunologically-induced anti-glomerular basement membrane glomerulonephritis (anti-GBM GN). 12 kidney tissue samples of Smad3 KO/WT mice from normal control, UUO at day 5 or anti-GBM GN at day 10 models (n=2 in each group) for whole transcriptome RNA-sequencing.
Project description:To obtain an unbiased characterization of the resident and infiltrating immune cell populations of mouse kidneys in healthy and diseased states, we performed single cell RNA-seq of facs-sorted CD45+ immune cells and CD4+ T cells from naïve and injured kidneys, at selected time points.
Project description:Fibrosis is defined as an abnormal matrix remodeling and loss of tissue homeostasis due to excessive synthesis and accumulation of extracellular matrix proteins in tissues. At present, there is no effective therapy for organ fibrosis. Previous studies demonstrated that aged plasminogen activator inhibitor-1(PAI-1) knockout mice develop spontaneously cardiac-selective fibrosis without affecting any other organs including kidney. Therefore, the PAI-1 knockout model of cardiac fibrosis provides an excellent opportunity to find the igniter(s) of cardiac fibrosis and its status in unaffected organs. We hypothesized that differential expressions of profibrotic and antifibrotic genes in PAI-1 knockout hearts and unaffected organs lead to cardiac selective fibrosis. In order to address this prediction, we have used a genome-wide gene expression profiling of transcripts derived from aged PAI-1 knockout hearts and kidneys. The variations of global gene expression profiling were compared within four groups: wildtype heart vs. knockout heart; wildtype kidney vs. knockout kidney; knockout heart vs. knockout kidney and wildtype heart vs. wildtype kidney. Analysis of illumina-based microarray data revealed that several genes involved in different biological processes such as immune system processing, response to stress, cytokine signaling, cell proliferation, adhesion, migration, matrix organization and transcriptional regulation were affected in hearts and kidneys by the absence of PAI-1, a potent inhibitor of urokinase- and tissue-type plasminogen activator. Importantly, the expressions of a number of genes, involved in profibrotic pathways were upregulated or downregulated in PAI-1 knockout hearts compared to wildtype hearts and PAI-1 knockout kidneys. To our knowledge, this is the first comprehensive report on the influence of PAI-1 on global gene expression profiling in the heart and kidney and its implication in several biological processes including fibrogenesis. Total RNA was extracted from hearts and kidneys derived from three PAI-1 knockout (12- month old) and three wild-type mice (12-month old) using RNeasy Fibrous Tissue Mini Kit (Qiagen, Valencia, CA) following the manufacturer’s instructions. The quality of RNA (RNA Integrity, RIN) in all 12 samples (3 wildtype hearts; 3 PAI-1 KO hearts; 3 wildtype kidneys; and 3 PAI-1 KO kidneys) was checked using the bioanalyzer. We have used a genome-wide gene expression profiling of transcripts derived from aged PAI-1 knockout hearts and kidneys. The variations of global gene expression profiling were compared within four groups: wildtype heart vs. knockout heart; wildtype kidney vs. knockout kidney; knockout heart vs. knockout kidney and wildtype heart vs. wildtype kidney.
Project description:We analyzed differences in IRI kidneys between WT and Keap1 KD mice (= Nrf2-activated mice). To identify Nrf2-target genes or metabolic genes in kidneys, we examined the mRNA expression profile both in normal (uninjured) and IRI kidneys (at day1 after unilateral IRI) from mice We performed microarray analyses using 1) Injured kidneys at day 1 after unilateral IRI, and 2) intact kidneys from mice which did not undergo UIRI. Samples were harvested from Keap1 KD mice and WT mice, n = 2 each,
Project description:Increased export of transglutaminase-2 (TG2) by tubular epithelial cells (TECs) into the surrounding interstitium modifies the extracellular homeostatic balance leading to fibrotic membrane expansion. Although silencing of extracellular TG2 ameliorates progressive kidney scarring in animal models of chronic kidney disease, the pathway through which TG2 is secreted from TECs and contributes to disease progression has not been elucidated. In this study, we developed a global proteomic approach to identify binding partners of TG2 responsible for TG2 externalization in kidneys subjected to unilateral ureteric obstruction, using TG2-knockout kidneys as negative controls. We report a robust and unbiased analysis of the membrane interactome of TG2 in fibrotic kidneys relative to the entire proteome post-UUO detected by SWATH-mass spectrometry.
Project description:Proximal tubular epithelial cells (TECs) demand high energy and rely on mitochondrial oxidative phosphorylation as a main energy source. However, this is disturbed in renal fibrosis. Acetylation is an important posttranslational modification for mitochondrial metabolism. The mitochondrial protein NAD-dependent deacetylase sirtuin 3 (SIRT3) regulates mitochondrial metabolic function. Therefore, we aimed to identify the changes in the acetylome in tubules from fibrotic kidneys and determine their association with mitochondria. We found that decreased SIRT3 expression was accompanied by increased acetylation in mitochondria that have separated from TECs during the early phase of renal fibrosis. SIRT3 knockout mice were susceptible to hyper-acetylated mitochondrial proteins and to severe renal fibrosis. The activation of SIRT3 by honokiol ameliorated acetylation and prevented renal fibrosis. Analysis of the acetylome in separated tubules using LC-MS/MS showed that most kidney proteins were hyper-acetylated after unilateral ureteral obstruction. The increased acetylated proteins with 26.76% were mitochondrial proteins which were mapped to a broad range of mitochondrial pathways including fatty acid β-oxidation, the TCA cycle and oxidative phosphorylation. Pyruvate dehydrogenase E1α (PDHE1α), which is the primary link between glycolysis and the TCA cycle, was hyper-acetylated at lysine 385 in TECs after TGF-β1 stimulation, and was regulated by SIRT3. Our findings showed that mitochondrial proteins involved in regulating energy metabolism were acetylated and targeted by SIRT3 in TECs. The deacetylation of PDHE1α by SIRT3 at lysine 385 plays a key role in metabolic reprogramming associated with renal fibrosis.
Project description:OVE26 (OVE) mice provide a useful model of advanced diabetic nephropathy (DN) with respect to albuminuria and pathologies. We showed that albuminuria, reduced GFR and interstitial fibrosis, which normally take 8-9 months to develop, are more advanced in uninephrectomized OVE mice within 10 weeks of surgery, at 4.5 months of age. The accelerated progression of renal damage, especially renal fibrosis in OVE-uni mice, was also identified at the gene expression level. The hepatic fibrosis/hepatic stellate cell activation pathway was by far the most significant Ingenuity canonical pathway identified by gene array in OVE-uni mice. Many inflammatory- and immune-related pathways were found among the top pathways up-regulated in OVE-uni kidneys, including acute-phase response signaling, leukocyte extravasation, IL6, IL10, IL12 signaling, TREM1 signaling, dendritic cell maturation and the complement system. These pathways were also dramatically up-regulated in 8-month-old OVE mice (GSE20636). Nephrectomized OVE mice are a much faster alternative model for studying advanced renal disease in diabetes. Study of renal gene expression in diabetic OVE26 mice. Uninephrectomy was used as an accelerating factor. Pooled RNA samples from 4 individual mice in each treatment group (OVE-uni, OVE-sham, FVB-uni, FVB-sham) were used for probe hybridization. Treatment groups: OVE-uni: uninephrectomy treatment in diabetic mice OVE-sham: sham surgery treatment in diabetic mice FVB-uni: uninephrectomy treatment in nondiabetic mice FVB-sham: sham surgery treatment in nondiabetic mice
Project description:Polycystic Kidney Disease (PKD) is a genetic disease of the kidney characterized by the gradual replacement of normal kidney parenchyma by fluid-filled cysts and fibrotic tissue. Autosomal Dominant Polycystic Kidney Disease (ADPKD) is caused by mutations in the PKD1 or PKD2 gene. Here we present an RNASeq experiment designed to investigate the effect of a kidney specific and Tamoxifen inducible knockout of the Pkd1 gene in mice. The Pkd1cko mice were harvested at different time points 2-weeks, 3-weeks, 5-weeks, 10.5-weeks, 11-weeks and 15-weeks after gene inactivation.