Project description:In order to identify major regulatory events in the immediate phase of renal IRI associated with CCN2, we performed full transcriptome RNA-sequencing on a cDNA library constructed from RNA extracted from samples of kidney cortex.
Project description:Differential gene expression of mouse cytokines and chemokines in Rag1 knockout (Rag1-/- or Rag1-KO) and Rag1-/- Tbx21-/- double knockout (Rag1-Tbet-DKO) was tested in fatty liver ischemic-reperfusion injury (IRI). C57BL/6 mice harboring Rag1-/- or Rag1-/- Tbx21-/- deletions were fed with a normal chow diet (ND, 4.09 kcal/gram,13.4% kJ/fat) or a high-fat diet (HFD, 5.10 kcal/gram, 60% kJ/fat). To induce liver ischemic-reperfusion injury in mice, an atraumatic micro clip was placed across the hepatic hilus, which interrupted the blood supply to the left and median lobes of the liver for 45-minutes of partial warm ischemia time. After 24 hours of liver IRI, the affected left lobe of the liver was harvested and stored in Allprotect Tissue Reagent (Qiagen). We used Qiagen RT² Profiler™ PCR Array for mouse cytokines & chemokines to distinguish immunologically related and diet-specific gene signatures specific to liver IRI in Rag1-KO and Rag1-Tbet-DKO mice.
Project description:The cellular communication network (CCN) 2, also known as CTGF, is a secreted matricellular protein with regulatory functions in vasoproliferative and fibrotic diseases. Although CCN2 functions extend to developmental processes, the impact of CCN2/CTGF expression, or lack thereof, during retinogenesis is unknown. Herein, we used bulk RNA-sequencing to determine the transcriptomic changes associated with global deletion of CCN2 in E18.5 mouse retinas. we show that CCN2 signals act on intrinsic signal transduction pathway genes and induce genetic reprogramming of retinal progenitor cells endowing these cells with neurogenic and gliogenic potentials.
Project description:To identify the direct m6A demethylation targets of ALKBH5 at the onset of renal IRI, we performed methylated RNA immunoprecipitation sequencing (MeRIP-seq) and RNA sequencing (RNA-seq) using RNA isolated from IRI mouse kidney of WT and KO mice 24h after I/R (WT n=3 vs. KO n=3)
Project description:TGF-β stimulates CCN2 expression which in turn amplifies TGF-β signaling. This process promotes extracellular matrix production and accelerates the pathological progression of fibrotic diseases. Alternative splicing plays an important role in multiple disease development, while U2 small nuclear RNA auxiliary factor 2 (U2AF2) is an essential factor in the early steps of pre-mRNA splicing. However, the molecular mechanism underlying abnormal CCN2 expression upon TGF-β stimulation remains unclear. This study elucidates that SIRT4 acts as a master regulator for CCN2 expression in response to TGF-β by modulating U2AF2-mediated alternative splicing. Analyses of renal biopsy specimens from patients with CKD and mouse fibrotic kidney tissues revealed marked nuclear accumulation of SIRT4. The tubulointerstitial fibrosis was alleviated by global deletion or tubular epithelial cell (TEC)-specific knockout of Sirt4, and aggravated by adeno-associated virus-mediated SIRT4 overexpression in TECs. Furthermore, SIRT4 was found to translocate from the mitochondria to the cytoplasm through the BAX/BAK pore under TGF-β stimulation. In the cytoplasm, TGF-β activated the ERK pathway and induced the phosphorylation of SIRT4 at Ser36, which further promoted its interaction with importin α1 and subsequent nuclear translocation. In the nucleus, SIRT4 was found to deacetylate U2AF2 at K413, facilitating the splicing of CCN2 pre-mRNA to promote CCN2 protein expression. Importantly, exosomes containing anti-SIRT4 antibodies were found to effectively mitigate the UUO-induced kidney fibrosis in mice. Collectively, these findings indicated that SIRT4 plays a role in kidney fibrosis by regulating CCN2 expression via the pre-mRNA splicing.
Project description:Vascular smooth muscle cell (VSMC) phenotypic switching is widely recognized as a key mechanism responsible for the pathogenesis of several aortic diseases such as aortic aneurysm. Cellular communication network factor 2 (CCN2), often upregulated in human pathologies and animal disease models, exerts a myriad of context-dependent biological functions. However, current understanding of the role of SMC-CCN2 in SMC phenotypic switching and its function in the pathology of abdominal aortic aneurysm (AAA) is lacking. Here we report the effect of SMC-restricted CCN2 deficiency of hypercholesterolemic mice on gene expression in infrarenal aorta with or without angiotensin II (Ang II)-infusion.
Project description:Hepatocellular carcinoma (HCC) is the second leading cause of cancer death worldwide. Most patients are at an advanced stage at diagnosis, and are not eligible for curative therapy. Chemotherapy is an alternative treatment for advanced HCCs, but resistance is found in many patients. Understanding the underlying mechanisms in chemo-resistance is critical to further improve the efficacy of HCC treatment. In this study, we found that increased expression of Id-1 and CCN2 were closely related to oxaliplatin resistance in HCC. Upregulation of CCN2 and Id-1 was independently associated with shorter survival and increased recurrence in HCC patients, and significantly enhanced oxaliplatin resistance and promoted lung metastasis in vivo, whereas knock-down of their expression significantly reversed the chemo-resistance and inhibited HCC cell stemness. cDNA microarrays and PCR revealed that Id-1 and MAPK pathway were the downstream signaling of CCN2, and Id-1 could upregulate CCN2 in a positive feedback manner. Moreover, CCN2 significantly enhanced oxaliplatin resistance by activating the MAPK signaling pathway and upregulating Id-1 expression. Meanwhile, MAPK/Id-1 signaling was demonstrated as one of the most important autocrine signaling pathways regulated by CCN2 in oxaliplatin-resistant models, and combination with sorafenib could improve the efficacy of oxaliplatin in HCC. Conclusions: These findings suggest that CCN2-MAPK-Id-1 loop feedback amplification is involved in oxaliplatin-resistant HCC, and the combination of oxaliplatin with inhibitor of CCN2 or MAPK signaling could provide a promising approach to ameliorating HCC progression and oxaliplatin resistance.
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:N-glycanase 1(NGLY1) catalyzes the removal of N-linked glycans from newly synthesized or misfolded protein to exert protein quality control function via the process of endoplasmic reticulum-associated degradation (ERAD). NGLY1 deficiency (OMIM 615273) is a newly diagnosed rare genetic disorder with ~60 patients worldwide to date. The affected individuals present a broad spectrum of clinical features, including developmental delay, seizures, muscle weakness, liver failure, and the reduced secretion of sweats and tears. Recent studies explored several possible molecular mechanisms of NGLY1 deficiency including in vivo proteostasis, mitochondrial homeostasis, innate immunity, water and ion transport, with the goal of linking these findings to the pathophysiology of the disease. This study focuses on the dysregulation of ERAD in NGLY1 deficiency. We demonstrate the abnormal accumulation of ERAD substrates in NGLY1 deficient cells. Comprehensive global quantitative proteomics discovered elevated levels of novel endogenous proteins in NGLY1 defective human and mouse cells. Further biological validation assays confirmed the altered abundance of several key candidates’ that were observed in the isobarically labeled proteomic experiments. CCN2 was selected for further analysis due to its high fold change in different cell models of NGLY1 deficiency. Functional assays show elevated CCN2 and over-stimulated TGF-β signaling in NGLY1 deficient cells. Given the important role of CCN2 and TGF-β pathway in mediating systemic fibrosis, we propose a potential link of increased CCN2 and TGF-β signaling to microscopic liver fibrosis in NGLY1 patients.
Project description:Ischemia reperfusion injury (IRI) in organ transplantation remains a significant problem with limited alternative therapeutic options. Organs that undergo significant damage during IRI, particularly those enduring long warm ischemia times, undergo significant delayed graft function (DGF) after reperfusion and tend to have greater complications long term with the onset of chronic rejection. The gas molecule carbon monoxide (CO) has emerged as an agent that can suppress IRI in rodent models of solid organ transplantation. Since the use of CO is a potential therapeutic modality in humans, we tested if CO can prevent DGF in a pig model of kidney transplantation Keywords: stress response, treatment response 18 Samples from pig kidneys, two naïve controls, two timepoints, two conditions, 4 replicates