scholarly journals RhoA/Rho kinase mediates TGF-β1-induced kidney myofibroblast activation through Poldip2/Nox4-derived reactive oxygen species

2014 ◽  
Vol 307 (2) ◽  
pp. F159-F171 ◽  
Author(s):  
Nagaraj Manickam ◽  
Mandakini Patel ◽  
Kathy K. Griendling ◽  
Yves Gorin ◽  
Jeffrey L. Barnes
Keyword(s):  
Nadph Oxidase ◽  
Oxidase Activity ◽  
Transforming Growth Factor ◽  
Rat Kidney ◽  
Smooth Muscle Actin ◽  
Rho Kinase ◽  
Ros Generation ◽  
Myofibroblast Differentiation ◽  
Interacting Protein ◽  
Nadph Oxidase Activity

The small G proteins Rac1 and RhoA regulate actin cytoskeleton, cell shape, adhesion, migration, and proliferation. Recent studies in our laboratory have shown that NADPH oxidase Nox4-derived ROS are involved in transforming growth factor (TGF)-β1-induced rat kidney myofibroblast differentiation assessed by the acquisition of an α-smooth muscle actin (α-SMA) phenotype and expression of an alternatively spliced fibronectin variant (Fn-EIIIA). Rac1 and RhoA are essential in signaling by some Nox homologs, but their role as effectors of Nox4 in kidney myofibroblast differentiation is not known. In the present study, we explored a link among Rac1 and RhoA and Nox4-dependent ROS generation in TGF-β1-induced kidney myofibroblast activation. TGF-β1 stimulated an increase in Nox4 protein expression, NADPH oxidase activity, and abundant α-SMA and Fn-EIIIA expression. RhoA but not Rac1 was involved in TGF-β1 induction of Nox4 signaling of kidney myofibroblast activation. TGF-β1 stimulated active RhoA-GTP and increased Rho kinase (ROCK). Inhibition of RhoA with small interfering RNA and ROCK using Y-27632 significantly reduced TGF-β1-induced stimulation of Nox4 protein, NADPH oxidase activity, and α-SMA and Fn-EIIIA expression. Treatment with diphenyleneiodonium, an inhibitor of NADPH oxidase, did not decrease RhoA activation but inhibited TGF-β1-induced α-SMA and Fn-EIIIA expression, indicating that RhoA is upstream of ROS generation. RhoA/ROCK also regulated polymerase (DNA-directed) δ-interacting protein 2 (Poldip2), a newly discovered Nox4 enhancer protein. Collectively, these data indicate that RhoA/ROCK is upstream of Poldip2-dependent Nox4 regulation and ROS production and induces redox signaling of kidney myofibroblast activation and may broader implications in the pathophysiology of renal fibrosis.

Mitochondria-targeted peptide SS-31 attenuates renal injury via an antioxidant effect in diabetic nephropathy

2016 ◽  
Vol 310 (6) ◽  
pp. F547-F559 ◽  
Author(s):  
Yanjuan Hou ◽  
Shuangcheng Li ◽  
Ming Wu ◽  
Jinying Wei ◽  
Yunzhuo Ren ◽  
...  
Keyword(s):  
Diabetic Nephropathy ◽  
Nadph Oxidase ◽  
P38 Mapk ◽  
Renal Injury ◽  
Oxidase Activity ◽  
Transforming Growth Factor ◽  
Ros Generation ◽  
Diabetic Mice ◽  
Nadph Oxidase Activity ◽  
Tgf Β1

Oxidative stress is implicated in the pathogenesis of diabetic kidney injury. SS-31 is a mitochondria-targeted tetrapeptide that can scavenge reactive oxygen species (ROS). Here, we investigated the effect and molecular mechanism of mitochondria-targeted antioxidant peptide SS-31 on injuries in diabetic kidneys and mouse mesangial cells (MMCs) exposed to high-glucose (HG) ambience. CD-1 mice underwent uninephrectomy and streptozotocin treatment prior to receiving daily intraperitoneal injection of SS-31 for 8 wk. The diabetic mice treated with SS-31 had alleviated proteinuria, urinary 8-hydroxy-2-deoxyguanosine level, glomerular hypertrophy, and accumulation of renal fibronectin and collagen IV. SS-31 attenuated renal cell apoptosis and expression of Bax and reversed the expression of Bcl-2 in diabetic mice kidneys. Furthermore, SS-31 inhibited expression of transforming-growth factor (TGF)-β1, Nox4, and thioredoxin-interacting protein (TXNIP), as well as activation of p38 MAPK and CREB and NADPH oxidase activity in diabetic kidneys. In vitro experiments using MMCs revealed that SS-31 inhibited HG-mediated ROS generation, apoptosis, expression of cleaved caspase-3, Bax/Bcl-2 ratio, and cytochrome c (cyt c) release from mitochondria. SS-31 normalized mitochondrial potential (ΔΨm) and ATP alterations, and inhibited the expression of TGF-β1, Nox4, and TXNIP, as well as activation of p38 MAPK and CREB and NADPH oxidase activity in MMCs under HG conditions. SS-31 treatment also could reverse the reduction of thioredoxin (TRX) biologic activity and upregulate expression of thioredoxin 2 (TRX2) in MMCs under HG conditions. In conclusion, this study demonstrates a protective effect of SS-31 against HG-induced renal injury via an antioxidant mechanism in diabetic nephropathy.

Rutaecarpine prevents hypoxia–reoxygenation-induced myocardial cell apoptosis via inhibition of NADPH oxidases

2011 ◽  
Vol 89 (3) ◽  
pp. 177-186 ◽  
Author(s):  
Mei-Hua Bao ◽  
Wen Dai ◽  
Yuan-Jian Li ◽  
Chang-Ping Hu
Keyword(s):  
Lactate Dehydrogenase ◽  
Nadph Oxidase ◽  
Cell Viability ◽  
Cell Apoptosis ◽  
Oxidase Activity ◽  
Ventricular Remodeling ◽  
Myocardial Cell ◽  
Ros Generation ◽  
Nadph Oxidase Activity ◽  
Hypoxia Reoxygenation

It is proposed that myocardial cell apoptosis causes ventricular remodeling and heart failure. The aim of the present study was to determine the effects of rutaecarpine (Rut) on hypoxia–reoxygenation (H–R)-induced apoptosis in myocardial cell line H9c2, as well as the underlying mechanisms. Cultured H9c2 cells were exposed to hypoxia for 24 h, followed by 12 h reoxygenation. Rut (in concentrations of 0.1, 1, and 10 µmol/L) was added 1 h prior to H–R. Cell viability and lactate dehydrogenase were measured to evaluate the cell injuries. Apoptosis was evaluated by Hoechst 33258 staining and flow cytometry. NADPH oxidase activity was measured by assay kit; intracellular reactive oxygen species (ROS) generation was detected by 2′,7′-dichlorofluorescein diacetate; and Nox2, Nox4, and p47phox mRNA and protein expression were analyzed by real-time PCR and Western blotting, respectively. The results showed that H–R significantly decreased cell viability and increased the lactate dehydrogenase release, as well as the apoptotic rate, concomitantly with enhanced NADPH oxidase activity. H–R also upregulated mRNA and protein expressions of Nox2, Nox4, and p47phox and increased ROS production. Treatment with Rut markedly reversed these effects introduced by H–R. These results suggest that the protective effects of Rut against H–R-induced myocardial cell injury and apoptosis might, at least partly, be due to the inhibition of the NADPH oxidase – ROS pathway.

scholarly journals The two formyl peptide receptors differently regulate GPR84-mediated neutrophil NADPH-oxidase activity

2020 ◽  
Author(s):  
Jonas Mårtensson ◽  
Martina Sundqvist ◽  
Asmita Manandhar ◽  
Loukas Ieremias ◽  
Linjie Zhang ◽  
...  
Keyword(s):  
Nadph Oxidase ◽  
Oxidase Activity ◽  
Human Neutrophils ◽  
Ros Generation ◽  
Ros Production ◽  
Peptide Receptors ◽  
Nadph Oxidase Activity ◽  
Formyl Peptide Receptors ◽  
Formyl Peptide ◽  
Specific Antagonist

ABSTRACTNeutrophils express many G protein-coupled receptors (GPCRs) including the two formyl peptide receptors (FPR1 and FPR2) and the medium chain fatty acid receptor GPR84. The FPRs are known to define a hierarchy among neutrophil GPCRs, i.e., the GPCR-mediated response can be either suppressed or amplified by signals generated by FPRs. In this study, we investigated the position of GPR84 in the FPR-defined hierarchy regarding the activation of neutrophil NADPH-oxidase, an enzyme system designed to generate reactive oxygen species (ROS). When naïve neutrophils are activated by GPR84 agonists a modest ROS release was induced. However, vast amounts of ROS production was induced by these GPR84 agonists in FPR2-desensitized neutrophils, and the response is inhibited not only by a GPR84 antagonist but also by an FPR2 specific antagonist. This suggests that the amplified GPR84 agonist response is achieved through a reactivation of the desensitized FPR2. In addition, the GPR84-mediated FPR2 reactivation was independent of β-arrestin recruitment and sensitive to a protein phosphatase inhibitor. In contrast, the modest ROS production induced by GPR84 agonists was primarily suppressed in FPR1-desensitized neutrophils through hierarchical desensitization of GPR84 by FPR1 generated signals.In summary, our data show that FPRs control the NADPH-oxidase activity mediated through GPR84 in human neutrophils. While an amplified ROS generation is achieved by GPR84 agonists through reactivation of desensitized FPR2, FPR1 heterologously desensitizes GPR84 and by that suppresses the release of ROS induced by GPR84 agonists.

scholarly journals Endothelial FAK suppresses NADPH oxidase activity and ROS generation to prevent ALI

2011 ◽  
Vol 25 (S1) ◽  
Author(s):  
Tracy Thennes ◽  
Mohammad Tauseef ◽  
Marcello Bonini ◽  
Joachim Gothert ◽  
Tang‐Long Shen ◽  
...  
Keyword(s):  
Nadph Oxidase ◽  
Oxidase Activity ◽  
Ros Generation ◽  
Nadph Oxidase Activity

scholarly journals Neuroprotective Benefits of Exercise and MitoQ on Memory Function, Mitochondrial Dynamics, Oxidative Stress, and Neuroinflammation in D-Galactose-Induced Aging Rats

2021 ◽  
Vol 11 (2) ◽  
pp. 164
Author(s):  
Jae-Hoon Jeong ◽  
Jung-Hoon Koo ◽  
Jang Soo Yook ◽  
Joon-Yong Cho ◽  
Eun-Bum Kang
Keyword(s):  
Oxidative Stress ◽  
Antioxidant Activity ◽  
Cognitive Impairment ◽  
Nadph Oxidase ◽  
Learning And Memory ◽  
Oxidase Activity ◽  
Mitochondrial Dynamics ◽  
Nadph Oxidase Activity ◽  
Aging Rats ◽  
Positive Effects

Exercise and antioxidants have health benefits that improve cognitive impairment and may act synergistically. In this study, we examined the effects of treadmill exercise (TE) and mitochondria-targeted antioxidant mitoquinone (MitoQ), individually or combined, on learning and memory, mitochondrial dynamics, NADPH oxidase activity, and neuroinflammation and antioxidant activity in the hippocampus of D-galactose-induced aging rats. TE alone and TE combined with MitoQ in aging rats reduced mitochondrial fission factors (Drp1, Fis1) and increased mitochondrial fusion factors (Mfn1, Mfn2, Opa1). These groups also exhibited improved NADPH oxidase activity and antioxidant activity (SOD-2, catalase). TE or MitoQ alone decreased neuroinflammatory response (COX-2, TNF-α), but the suppression was greater with their combination. In addition, aging-increased neuroinflammation in the dentate gyrus was decreased in TE but not MitoQ treatment. Learning and memory tests showed that, contrarily, MitoQ alone demonstrated some similar effects to TE but not a definitive improvement. In conclusion, this study demonstrated that MitoQ exerted some positive effects on aging when used as an isolated treatment, but TE had a more effective role on cognitive impairment, oxidative stress, inflammation, and mitochondria dysfunction. Our findings suggest that the combination of TE and MitoQ exerted no synergistic effects and indicated regular exercise should be the first priority in neuroprotection of age-related cognitive decline.

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