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.

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.

High glucose-induced RhoA activation requires caveolae and PKCβ1-mediated ROS generation

2012 ◽  
Vol 302 (1) ◽  
pp. F159-F172 ◽  
Author(s):  
Y. Zhang ◽  
F. Peng ◽  
B. Gao ◽  
A. J. Ingram ◽  
J. C. Krepinsky
Keyword(s):  
Diabetic Nephropathy ◽  
Nadph Oxidase ◽  
High Glucose ◽  
Transforming Growth Factor ◽  
Mesangial Cells ◽  
Ros Generation ◽  
Caveolin 1 ◽  
Rhoa Activation ◽  
Rhoa Signaling ◽  
Tgf Β1

Glomerular matrix accumulation is a hallmark of diabetic nephropathy. We previously showed that RhoA activation by high glucose in mesangial cells (MC) leads to matrix upregulation (Peng F, Wu D, Gao B, Ingram AJ, Zhang B, Chorneyko K, McKenzie R, Krepinsky JC. Diabetes 57: 1683–1692, 2008). Here, we study the mechanism whereby RhoA is activated. In primary rat MC, RhoA activation required glucose entry and metabolism. Broad PKC inhibitors (PMA, bisindolylmaleimide, Gö6976), as well as specific PKCβ blockade with an inhibitor and small interfering RNA (siRNA), prevented RhoA activation by glucose. PKCβ inhibition also abrogated reactive oxygen species (ROS) generation by glucose. The ROS scavenger N-acetylcysteine (NAC) or NADPH oxidase inhibitors apocynin and DPI prevented glucose-induced RhoA activation. RhoA and some PKC isoforms localize to caveolae. Chemical disruption of these microdomains prevented RhoA and PKCβ1 activation by glucose. In caveolin-1 knockout cells, glucose did not induce RhoA and PKCβ1 activation; these responses were rescued by caveolin-1 reexpression. Furthermore, glucose-induced ROS generation was significantly attenuated by chemical disruption of caveolae and in knockout cells. Downstream of RhoA signaling, activator protein-1 (AP-1) activation was also inhibited by disrupting caveolae, was absent in caveolin-1 knockout MC and rescued by caveolin-1 reexpression. Finally, transforming growth factor (TGF)-β1 upregulation, mediated by AP-1, was prevented by RhoA signaling inhibition and by disruption or absence of caveolae. In conclusion, RhoA activation by glucose is dependent on PKCβ1-induced ROS generation, most likely through NADPH oxidase. The activation of PKCβ1 and its downstream effects, including upregulation of TGF-β1, requires caveolae. These microdomains are thus important mediators of the profibrogenic process associated with diabetic nephropathy.

scholarly journals Protective Role of Endogenous Kallistatin in Vascular Injury and Senescence by Inhibiting Oxidative Stress and Inflammation

2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Julie Chao ◽  
Youming Guo ◽  
Lee Chao
Keyword(s):  
Oxidative Stress ◽  
Endothelial Cells ◽  
Nadph Oxidase ◽  
Vascular Injury ◽  
Oxidase Activity ◽  
Sirtuin 1 ◽  
Mouse Lung ◽  
Heparin Binding ◽  
Diabetic Mice ◽  
Nadph Oxidase Activity

Kallistatin was identified in human plasma as a tissue kallikrein-binding protein and a serine proteinase inhibitor. Kallistatin exerts pleiotropic effects on angiogenesis, oxidative stress, inflammation, apoptosis, fibrosis, and tumor growth. Kallistatin levels are markedly reduced in patients with coronary artery disease, sepsis, diabetic retinopathy, inflammatory bowel disease, pneumonia, and cancer. Moreover, plasma kallistatin levels are positively associated with leukocyte telomere length in young African Americans, indicating the involvement of kallistatin in aging. In addition, kallistatin treatment promotes vascular repair by increasing the migration and function of endothelial progenitor cells (EPCs). Kallistatin via its heparin-binding site antagonizes TNF-α-induced senescence and superoxide formation, while kallistatin’s active site is essential for inhibiting miR-34a synthesis, thus elevating sirtuin 1 (SIRT1)/eNOS synthesis in EPCs. Kallistatin inhibits oxidative stress-induced cellular senescence by upregulating Let-7g synthesis, leading to modulate Let-7g-mediated miR-34a-SIRT1-eNOS signaling pathway in human endothelial cells. Exogenous kallistatin administration attenuates vascular injury and senescence in association with increased SIRT1 and eNOS levels and reduced miR-34a synthesis and NADPH oxidase activity, as well as TNF-α and ICAM-1 expression in the aortas of streptozotocin- (STZ-) induced diabetic mice. Conversely, endothelial-specific depletion of kallistatin aggravates vascular senescence, oxidative stress, and inflammation, with further reduction of Let-7g, SIRT1, and eNOS and elevation of miR-34a in mouse lung endothelial cells. Furthermore, systemic depletion of kallistatin exacerbates aortic injury, senescence, NADPH oxidase activity, and inflammatory gene expression in STZ-induced diabetic mice. These findings indicate that endogenous kallistatin displays a novel role in protection against vascular injury and senescence by inhibiting oxidative stress and inflammation.

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 RAC2-P38 MAPK-dependent NADPH oxidase activity is associated with the resistance of quiescent cells to ionizing radiation

Cell Cycle ◽  
2016 ◽  
Vol 16 (1) ◽  
pp. 113-122 ◽  
Author(s):  
Hailong Pei ◽  
Jian Zhang ◽  
Jing Nie ◽  
Nan Ding ◽  
Wentao Hu ◽  
...  
Keyword(s):  
Ionizing Radiation ◽  
Nadph Oxidase ◽  
P38 Mapk ◽  
Oxidase Activity ◽  
Nadph Oxidase Activity ◽  
Quiescent Cells

scholarly journals Involvement of p300/CBP and epigenetic histone acetylation in TGF-β1-mediated gene transcription in mesangial cells

2013 ◽  
Vol 304 (5) ◽  
pp. F601-F613 ◽  
Author(s):  
Hang Yuan ◽  
Marpadga A. Reddy ◽  
Guangdong Sun ◽  
Linda Lanting ◽  
Mei Wang ◽  
...  
Keyword(s):  
Diabetic Nephropathy ◽  
Histone Acetylation ◽  
Transforming Growth Factor ◽  
Mesangial Cells ◽  
Mrna Levels ◽  
Creb Binding Protein ◽  
Diabetic Mice ◽  
Plasminogen Activator Inhibitor 1 ◽  
Tgf Β1 ◽  
Pai 1

Transforming growth factor-β1 (TGF-β1)-induced expression of plasminogen activator inhibitor-1 (PAI-1) and p21 in renal mesangial cells (MCs) plays a major role in glomerulosclerosis and hypertrophy, key events in the pathogenesis of diabetic nephropathy. However, the involvement of histone acetyl transferases (HATs) and histone deacetylases (HDACs) that regulate epigenetic histone lysine acetylation, and their interaction with TGF-β1-responsive transcription factors, are not clear. We evaluated the roles of histone acetylation, specific HATs, and HDACs in TGF-β1-induced gene expression in rat mesangial cells (RMCs) and in glomeruli from diabetic mice. Overexpression of HATs CREB binding protein (CBP) or p300, but not p300/CBP-activating factor, significantly enhanced TGF-β1-induced PAI-1 and p21 mRNA levels as well as transactivation of their promoters in RMCs. Conversely, they were significantly attenuated by HAT domain mutants of CBP and p300 or overexpression of HDAC-1 and HDAC-5. Chromatin immunoprecipitation assays showed that TGF-β1 treatment led to a time-dependent enrichment of histone H3-lysine9/14-acetylation (H3K9/14Ac) and p300/CBP occupancies around Smad and Sp1 binding sites at the PAI-1 and p21 promoters. TGF-β1 also enhanced the interaction of p300 with Smad2/3 and Sp1 and increased Smad2/3 acetylation. High glucose-treated RMCs exhibited increased PAI-1 and p21 levels, and promoter H3K9/14Ac, which were blocked by TGF-β1 antibodies. Furthermore, increased PAI-1 and p21 expression was associated with elevated promoter H3K9/14Ac levels in glomeruli from diabetic mice. Thus TGF-β1-induced PAI-1 and p21 expression involves interaction of p300/CBP with Smads and Sp1, and increased promoter access via p300/CBP-induced H3K9/14Ac. This in turn can augment glomerular dysfunction linked to diabetic nephropathy.

Regulation of NADPH Oxidase Activity Is Associated with miRNA-25-Mediated NOX4 Expression in Experimental Diabetic Nephropathy

2010 ◽  
Vol 32 (6) ◽  
pp. 581-589 ◽  
Author(s):  
Yibing Fu ◽  
Yan Zhang ◽  
Ziying Wang ◽  
Linlin Wang ◽  
Xinbing Wei ◽  
...  
Keyword(s):  
Diabetic Nephropathy ◽  
Nadph Oxidase ◽  
Oxidase Activity ◽  
Nadph Oxidase Activity ◽  
Mirna 25

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 Characterization of ferroptosis in kidney tubular cell death under diabetic conditions

2021 ◽  
Vol 12 (2) ◽  
Author(s):  
Seonghun Kim ◽  
Shin-Wook Kang ◽  
Jeongho Joo ◽  
Seung Hyeok Han ◽  
Huiyoon Shin ◽  
...  
Keyword(s):  
Lipid Peroxidation ◽  
Cell Death ◽  
Diabetic Nephropathy ◽  
Transforming Growth Factor ◽  
Lipid Peroxide ◽  
Tubular Cell ◽  
Diabetic Patients ◽  
Diabetic Mice ◽  
Glutathione Concentration ◽  
Tgf Β1

AbstractKidney tubular cell death induced by transforming growth factor-β1 (TGF-β1) is known to contribute to diabetic nephropathy, a major complication of diabetes. Caspase-3-dependent apoptosis and caspase-1-dependent pyroptosis are also involved in tubular cell death under diabetic conditions. Recently, ferroptosis, an atypical form of iron-dependent cell death, was reported to cause kidney disease, including acute kidney injury. Ferroptosis is primed by lipid peroxide accumulation through the cystine/glutamate antiporter system Xc− (xCT) and glutathione peroxidase 4 (GPX4)-dependent mechanisms. The aim of this study was to evaluate the role of ferroptosis in diabetes-induced tubular injury. TGF-β1-stimulated proximal tubular epithelial cells and diabetic mice models were used for in vitro and in vivo experiments, respectively. xCT and GPX4 expression, cell viability, glutathione concentration, and lipid peroxidation were quantified to indicate ferroptosis. The effect of ferroptosis inhibition was also assessed. In kidney biopsy samples from diabetic patients, xCT and GPX4 mRNA expression was decreased compared to nondiabetic samples. In TGF-β1-stimulated tubular cells, intracellular glutathione concentration was reduced and lipid peroxidation was enhanced, both of which are related to ferroptosis-related cell death. Ferrostatin-1 (Fer-1), a ferroptosis inhibitor, alleviated TGF-β1-induced ferroptosis. In diabetic mice, kidney mRNA and protein expressions of xCT and GPX4 were reduced compared to control. Kidney glutathione concentration was decreased, while lipid peroxidation was increased in these mice, and these changes were alleviated by Fer-1 treatment. Ferroptosis is involved in kidney tubular cell death under diabetic conditions. Ferroptosis inhibition could be a therapeutic option for diabetic nephropathy.

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