scholarly journals Alcohol promotes renal fibrosis by activating Nox2/4-mediated DNA methylation of Smad7

2020 ◽  
Vol 134 (2) ◽  
pp. 103-122 ◽  
Author(s):  
Qin Yang ◽  
Hai-Yong Chen ◽  
Jia-nan Wang ◽  
Huai-Qin Han ◽  
Ling Jiang ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Dna Methylation ◽  
Animal Model ◽  
Renal Fibrosis ◽  
Collagen I ◽  
Sequencing Analysis ◽  
Fibrotic Response ◽  
Kidney Fibrosis

Abstract Alcohol consumption causes renal injury and compromises kidney function. The underlying mechanism of the alcoholic kidney disease remains largely unknown. In the present study, an alcoholic renal fibrosis animal model was first employed which mice received liquid diet containing alcohol for 4 to 12 weeks. The Masson’s Trichrome staining analysis showed that kidney fibrosis increased at week 8 and 12 in the animal model that was further confirmed by albumin assay, Western blot, immunostaining and real-time PCR of fibrotic indexes (collagen I and α-SMA). In vitro analysis also confirmed that alcohol significantly induced fibrotic response (collagen I and α-SMA) in HK2 tubular epithelial cells. Importantly, both in vivo and in vitro studies showed alcohol treatments decreased Smad7 and activated Smad3. We further determined how the alcohol affected the balance of Smad7 (inhibitory Smad) and Smad3 (regulatory Smad). Genome-wide methylation sequencing showed an increased DNA methylation of many genes and bisulfite sequencing analysis showed an increased DNA methylation of Smad7 after alcohol ingestion. We also found DNA methylation of Smad7 was mediated by DNMT1 in ethyl alcohol (EtOH)-treated HK2 cells. Knockdown of Nox2 or Nox4 decreased DNMT1 and rebalanced Smad7/Smad3 axis, and thereby relieved EtOH-induced fibrotic response. The inhibition of reactive oxygen species by the intraperitoneal injection of apocynin attenuated renal fibrosis and restored renal function in the alcoholic mice. Collectively, we established novel in vivo and in vitro alcoholic kidney fibrosis models and found that alcohol induces renal fibrosis by activating oxidative stress-induced DNA methylation of Smad7. Suppression of Nox-mediated oxidative stress may be a potential therapy for long-term alcohol abuse-induced kidney fibrosis.

scholarly journals Novel insights into the regulation of chemerin expression: role of acute-phase cytokines and DNA methylation

2019 ◽  
Author(s):  
Kamila Kwiecien ◽  
Piotr Brzoza ◽  
Pawel Majewski ◽  
Izabella Skulimowska ◽  
Kamil Bednarczyk ◽  
...  
Keyword(s):  
Dna Methylation ◽  
Acute Phase ◽  
Molecular Mechanisms ◽  
Retinoic Acid Receptor ◽  
Constitutive Expression ◽  
Sequencing Analysis ◽  
Mrna Levels ◽  
Pleiotropic Actions

AbstractChemerin is a chemoattractant protein with adipokine properties encoded by the retinoic acid receptor responder 2 (RARRES2) gene. It has gained more attention over the past few years due to its multilevel impact on metabolism and immune responses. The pleiotropic actions of chemerin include chemotaxis of dendritic cells, macrophages and natural killers (NK) subsets, bactericidal activity as well as regulation of adipogenesis and glucose metabolism. Therefore, reflecting the pleiotropic actions of chemerin, expression of RARRES2 is regulated by a variety of inflammatory and metabolic mediators. However, for most cell types, the molecular mechanisms controlling constitutive and regulated chemerin expression are poorly characterized. Here we show that RARRES2 mRNA levels in murine adipocytes are upregulated in vitro and in vivo by acute-phase cytokines, IL-1β and OSM. In contrast to adipocytes, these cytokines exerted a weak, if any, response in mouse hepatocytes, suggesting that the effect of IL-1β and OSM on chemerin expression is specific to fat tissue. Moreover, we show that DNA methylation controls the constitutive expression of chemerin. Bisulfite sequencing analysis showed low methylation levels within −735 to +258 bp of the murine RARRES2 gene promoter in unstimulated adipocytes and hepatocytes. In contrast to these cells, the RARRES2 promoter is highly methylated in B lymphocytes, cells that do not produce chemerin. Together, our findings reveal previously uncharacterized mediators and mechanisms controlling chemerin expression in various cells.

scholarly journals Oxidative Stress Aggravates Apoptosis of Nucleus Pulposus Cells through m6A Modification of MAT2A Pre-mRNA by METTL16

2022 ◽  
Vol 2022 ◽  
pp. 1-15
Author(s):  
Peng-Bo Chen ◽  
Gui-Xun Shi ◽  
Tao Liu ◽  
Bo Li ◽  
Sheng-Dan Jiang ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Animal Model ◽  
Pilot Study ◽  
Nucleus Pulposus ◽  
Intervertebral Disc Degeneration ◽  
Nucleus Pulposus Cell ◽  
Nucleus Pulposus Cells ◽  
Human Npcs

The process of intervertebral disc degeneration (IVDD) is complex, and its mechanism is considered multifactorial. Apoptosis of oxidative stressed nucleus pulposus cells (NPCs) should be a fundamental element in the pathogenesis of IVDD. In our pilot study, we found that the expression of MAT2A decreased, and METTL16 increased in the degenerative nucleus pulposus tissues. Previous studies have shown that the balance of splicing, maturation, and degradation of MAT2A pre-mRNA is regulated by METTL16 m6A modification. In the current study, we aimed to figure out whether this mechanism was involved in the aberrant apoptosis of NPCs and IVDD. Human NPCs were isolated and cultured under oxidative stress. An IVDD animal model was established. It showed that significantly higher METTL16 expression and lower MAT2A expression were seen in either the NPCs under oxidative stress or the degenerative discs of the animal model. MAT2A was inhibited with siRNA in vitro or cycloleucine in vivo. METTL16 was overexpressed with lentivirus in vitro or in vivo. Downregulation of MAT2A or upregulation of METTL16 aggravated nucleus pulposus cell apoptosis and disc disorganization. The balance of splicing, maturation, and degradation of MAT2A pre-mRNA was significantly inclined to degradation in the NPCs with the overexpression of METTL16. Increased apoptosis of NPCs under oxidative stress could be rescued by reducing the expression of METTL16 using siRNA with more maturation of MAT2A pre-mRNA. Collectively, oxidative stress aggravates apoptosis of NPCs through disrupting the balance of splicing, maturation, and degradation of MAT2A pre-mRNA, which is m6A modified by METTL16.

scholarly journals Involvement of FATP2-mediated tubular lipid metabolic reprogramming in renal fibrogenesis

2020 ◽  
Vol 11 (11) ◽  
Author(s):  
Yuting Chen ◽  
Qi Yan ◽  
Mengyue Lv ◽  
Kaixin Song ◽  
Yue Dai ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Lipid Metabolism ◽  
Growth Factor ◽  
Renal Fibrosis ◽  
Interstitial Fibrosis ◽  
Tissue Growth ◽  
Metabolic Reprogramming ◽  
Kidney Fibrosis

AbstractFollowing a chronic insult, renal tubular epithelial cells (TECs) contribute to the development of kidney fibrosis through dysregulated lipid metabolism that lead to lipid accumulation and lipotoxicity. Intracellular lipid metabolism is tightly controlled by fatty acids (FAs) uptake, oxidation, lipogenesis, and lipolysis. Although it is widely accepted that impaired fatty acids oxidation (FAO) play a crucial role in renal fibrosis progression, other lipid metabolic pathways, especially FAs uptake, has not been investigated in fibrotic kidney. In this study, we aim to explore the potential mechanically role of FAs transporter in the pathogenesis of renal fibrosis. In the present study, the unbiased gene expression studies showed that fatty acid transporter 2 (FATP2) was one of the predominant expressed FAs transport in TECs and its expression was tightly associated with the decline of renal function. Treatment of unilateral ureteral obstruction (UUO) kidneys and TGF-β induced TECs with FATP2 inhibitor (FATP2i) lipofermata restored the FAO activities and alleviated fibrotic responses both in vivo and in vitro. Moreover, the expression of profibrotic cytokines including TGF-β, connective tissue growth factor (CTGF), fibroblast growth factor (FGF), and platelet-derived growth factor subunit B (PDGFB) were all decreased in FATP2i-treated UUO kidneys. Mechanically, FATP2i can effectively attenuate cell apoptosis and endoplasmic reticulum (ER) stress induced by TGF-β treatment in cultured TECs. Taking together, these findings reveal that FATP2 elicits a profibrotic response to renal interstitial fibrosis by inducing lipid metabolic reprogramming including abnormal FAs uptake and defective FAO in TECs.

scholarly journals Drugs Targeting Tumor-Initiating Cells Prolong Survival in a Post-Surgery, Post-Chemotherapy Ovarian Cancer Relapse Model

Cancers ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 1645
Author(s):  
Brittney S. Harrington ◽  
Michelle K. Ozaki ◽  
Michael W. Caminear ◽  
Lidia F. Hernandez ◽  
Elizabeth Jordan ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Ovarian Cancer ◽  
Drug Metabolism ◽  
Disease Recurrence ◽  
Adherent Cells ◽  
Sequencing Analysis ◽  
Post Surgery ◽  
Platinum Based Chemotherapy

Disease recurrence is the major cause of morbidity and mortality of ovarian cancer (OC). In terms of maintenance therapies after platinum-based chemotherapy, PARP inhibitors significantly improve the overall survival of patients with BRCA mutations but is of little benefit to patients without homologous recombination deficiency (HRD). The stem-like tumor-initiating cell (TIC) population within OC tumors are thought to contribute to disease recurrence and chemoresistance. Therefore, there is a need to identify drugs that target TICs to prevent relapse in OC without HRD. RNA sequencing analysis of OC cells grown in TIC conditions revealed a strong enrichment of genes involved in drug metabolism, oxidative phosphorylation and reactive oxygen species (ROS) pathways. Concurrently, a high-throughput drug screen identified drugs that showed efficacy against OC cells grown as TICs compared to adherent cells. Four drugs were chosen that affected drug metabolism and ROS response: disulfiram, bardoxolone methyl, elesclomol and salinomycin. The drugs were tested in vitro for effects on viability, sphere formation and markers of stemness CD133 and ALDH in TICs compared to adherent cells. The compounds promoted ROS accumulation and oxidative stress and disulfiram, elesclomol and salinomycin increased cell death following carboplatin treatment compared to carboplatin alone. Disulfiram and salinomycin were effective in a post-surgery, post-chemotherapy OC relapse model in vivo, demonstrating that enhancing oxidative stress in TICs can prevent OC recurrence.

scholarly journals Ameliorative Effects of Osthole on Experimental Renal Fibrosis in vivo and in vitro by Inhibiting IL-11/ERK1/2 Signaling

2021 ◽  
Vol 12 ◽  
Author(s):  
Fan Wu ◽  
Yan Zhao ◽  
Qingqing Shao ◽  
Ke Fang ◽  
Ruolan Dong ◽  
...  
Keyword(s):  
Signaling Pathway ◽  
Renal Fibrosis ◽  
Cell Model ◽  
Smooth Muscle Actin ◽  
Collagen I ◽  
Mrna Levels ◽  
Smad Signaling ◽  
Tgf Β1

Objectives: Natural product, osthole, has been proven to have a protective effect on organ fibrosis, including renal fibrosis. All of these studies are mainly focused on the regulation of TGF-β/Smad signaling pathway. However, due to the pleiotropic roles of TGF-β/Smad signaling, direct TGF-β-targeted treatments are unlikely to be therapeutically feasible in clinic. Recently, the downstream IL-11/ERK1/2 signaling of TGF-β has become an attractive therapeutic target without upstream disadvantages. Based on that, this study was designed to identify the potential effects of osthole on IL-11/ERK1/2 signaling pathway in renal fibrosis.Methods: The renal fibrosis model was established in vivo and in vitro, we investigated the effects of osthole on unilateral ureteral obstruction (UUO)-induced renal fibrosis and TGF-β-induced HK-2 cells. After preliminarily confirming the antifibrogenic effects of osthole and the link between its antifibrogenic effects and the inhibition of IL-11/ERK1/2 signaling, we applied a direct IL-11-induced HK-2 cells fibrosis model to further explore the inhibitory effects of osthole on IL-11/ERK1/2 signaling pathway.Results: Our results confirmed that osthole can decrease the secretion of fibrosis proteins, such as α-smooth muscle actin (α-SMA), collagen I, and fibronectin, ameliorate experimental renal fibrosis in vivo and in vitro, and the effect was associated with suppressing TGF-β1/Smad signaling. More importantly, we found that IL-11/ERK1/2 signaling in UUO-induced renal fibrosis and TGF-β-induced HK-2 cell model was obviously upregulated, and osthole treatment also significantly inhibited the abnormal IL-11/ERK1/2 signaling activation. Given the direct link between TGF-β/Smad signaling and IL-11/ERK1/2 signaling pathway, we have verified that osthole has a direct inhibitory effect on IL-11/ERK1/2 signaling independent of TGF-β signaling by using an IL-11-induced HK-2 cells fibrosis model. Osthole treatment decreased the protein expression of α-SMA, collagen I and fibronectin without changing their mRNA levels in IL-11-induced HK-2 cells. Moreover, it was observed that the IL-11/ERK1/2 inhibitor, U0126, partly blocked the antifibrogenic effects of osthole.Conclusion: In this study, we found that osthole has a previously unrecognized role in inhibiting IL-11/ERK1/2 signaling pathway. Our work demonstrated that the antifibrogenic effect of osthole is not only mediated by TGF-β/Smad2/3 signaling, but also directly mediated by IL-11/ERK1/2 signaling pathway independent of TGF-β1 signaling.

scholarly journals Role of JAK3 in the Pathogenesis of Oxidative Stress-Induced Kidney Fibrosis

2018 ◽  
Vol 2 (1) ◽  
pp. 18-26
Author(s):  
Betty Pat ◽  
David W Johnson ◽  
Glenda C Gobe
Keyword(s):  
Oxidative Stress ◽  
Protein Expression ◽  
Cell Lines ◽  
Janus Kinase ◽  
In Vivo Models ◽  
Kidney Fibrosis ◽  
Stat3 Phosphorylation ◽  
Mitotic Cells

The Janus kinase (JAK) tyrosine kinase family and JAK/STAT signal transduction pathway may act in kidney fibrogenesis. JAK3 expression was investigated in in vitro and in vivo models of kidney fibrosis involving oxidative stress. There was a marked down-regulation of JAK3 mRNA in rat kidney tubular epithelial cells (NRK52E) and fibroblasts (NRK49F) exposed to 1.0 mM H2O2 for 18–20 h compared with controls, which correlated with increased apoptosis and decreased mitosis in both cell lines. However, JAK3 protein levels were not significantly different in control and H2O2-treated epithelial and fibroblast cultures. JAK3 activation (phospho-tyrosine) increased in NRK52E cells and decreased in NRK49F cells with oxidative stress. STAT3 phosphorylation decreased in both cell lines with oxidative stress compared with controls. JAK3 protein expression and localisation were investigated in kidneys using the unilateral ureteral obstruction (UUO) model (0–7 days, rats) of kidney fibrosis that involves oxidative stress. JAK3 protein expression did not differ between UUO and controls; however, JAK3 localisation increased temporally with UUO, with strong epithelial expression in mitotic cells compared with controls. Apoptotic tubular epithelium showed minimal JAK3. In summary, in vitro, decreased kidney JAK3 mRNA after oxidative stress was not seen translationally. Differences in the activation of the JAK3/STAT3 pathway may have different consequences for renal fibrosis. In vivo, changes in JAK3 protein localisation, and especially its co-localisation with mitotic cells, indicate that JAK3 protein may contribute to renal tubular epithelial cell proliferation after oxidative stress.

scholarly journals Extracellular vesicles produced by bone marrow mesenchymal stem cells attenuate renal fibrosis, in part by inhibiting the RhoA/ROCK pathway, in a UUO rat model

2020 ◽  
Author(s):  
Zhengzhou Shi ◽  
Qi Wang ◽  
Youbo Zhang ◽  
Dapeng Jiang
Keyword(s):  
Oxidative Stress ◽  
Extracellular Vesicles ◽  
Renal Fibrosis ◽  
Sham Group ◽  
Rock Inhibitor ◽  
Marrow Mesenchymal Stem Cells ◽  
Hk2 Cells ◽  
Tgf Β1

Abstract Background Renal interstitial fibrosis is a critical symptom of chronic kidney disease (CKD) that is associated with high incidence. Extracellular vesicles produced by bone marrow mesenchymal stem cells (BMSC-EVs) can play important roles in the repair of injured tissues. However, no reports have investigated the role and mechanism of BMSC-EVs in renal fibrosis. Thus, we hypothesized that BMSC-EVs containing milk fat globule-EGF factor-8 (MFG-E8) could attenuate renal fibrosis by inhibiting the RhoA/ROCK pathway.Methods We investigated whether BMSC-EVs have antifibrotic effects in a rat model of renal fibrosis-rats subjected to unilateral ureteral obstruction (UUO) - as well as in cultured HK2 cells. In vivo, Sprague-Dawley (SD) rats were randomly divided into 6 groups: Sham group, Sham + EVs group, UUO group, UUO + EVs group, UUO + EVs Ctrl group, and UUO + EVs shMFGE8 group. In vitro, extracellular vesicles from BMSCs were collected and co-cultured with HK2 cells during transforming growth factor-β1 (TGF-β1) treatment. Besides, HK2 cells co-cultured with TGF-β1 were also treated with the ROCK inhibitor, Y-27632. Results Compared with the Sham group, UUO rats displayed fibrotic abnormalities, accompanied by increased expression of α-SMA and Fibronectin, and decreased expression of E-cadherin. Both molecular and pathological changes suggested an increased inflammation in damaged kidneys. Oxidative stress, as evidenced by decreased levels of SOD1 and Catalase, was also observed in UUO kidneys. In addition, activation of cleaved caspase-3 and PARP1 and increased apoptosis in the proximal tubules confirmed tubular cell apoptosis in the UUO group. All of these phenotypes exhibited by UUO rats were suppressed by treatment with BMSC-EVs. However, the protective effect of BMSC-EVs was completely abolished by inhibition of MFG-E8. Consistent with the in vivo results, treatment with BMSC-EVs reduced inflammation, oxidative stress, apoptosis, and fibrosis in HK-2 cells stimulated with TGF-β1 in vitro . Interestingly, treatment with Y-27632, a ROCK inhibitor, protected HK-2 cells against inflammation and fibrosis, although oxidative stress and apoptosis were unchanged. Conclusions In summary, our results show that BMSC-EVs containing MFG-E8 attenuate renal fibrosis, partly through RhoA/ROCK pathway inhibition.

scholarly journals Inhibition of DNMT1 and ERRα crosstalk suppresses breast cancer via derepression of IRF4

Oncogene ◽  
2020 ◽  
Vol 39 (41) ◽  
pp. 6406-6420
Author(s):  
Mathieu Vernier ◽  
Shawn McGuirk ◽  
Catherine R. Dufour ◽  
Liangxinyi Wan ◽  
Etienne Audet-Walsh ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Dna Methylation ◽  
Dna Methyltransferase ◽  
Large Scale ◽  
Transcriptional Control ◽  
Critical Role ◽  
Promoter Hypermethylation ◽  
Sequencing Analysis

Abstract DNA methylation is implicated in the acquisition of malignant phenotypes, and the use of epigenetic modulating drugs is a promising anti-cancer therapeutic strategy. 5-aza-2’deoxycytidine (decitabine, 5-azadC) is an FDA-approved DNA methyltransferase (DNMT) inhibitor with proven effectiveness against hematological malignancies and more recently triple-negative breast cancer (BC). Herein, genetic or pharmacological studies uncovered a hitherto unknown feedforward molecular link between DNMT1 and the estrogen related receptor α (ERRα), a key transcriptional regulator of cellular metabolism. Mechanistically, DNMT1 promotes ERRα stability which in turn couples DNMT1 transcription with that of the methionine cycle and S-adenosylmethionine synthesis to drive DNA methylation. In vitro and in vivo investigation using a pre-clinical mouse model of BC demonstrated a clear therapeutic advantage for combined administration of the ERRα inhibitor C29 with 5-azadC. A large-scale bisulfite genomic sequencing analysis revealed specific methylation perturbations fostering the discovery that reversal of promoter hypermethylation and consequently derepression of the tumor suppressor gene, IRF4, is a factor underlying the observed BC suppressive effects. This work thus uncovers a critical role of ERRα in the crosstalk between transcriptional control of metabolism and epigenetics and illustrates the potential for targeting ERRα in combination with DNMT inhibitors for BC treatment and other epigenetics-driven malignancies.

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