scholarly journals Protein disulfide isomerase inhibition impairs Keap1/Nrf2 signaling and mitochondrial function and induces apoptosis in renal proximal tubular cells

2020 ◽  
Vol 319 (4) ◽  
pp. F686-F696
Author(s):  
Indira D. Pokkunuri ◽  
Mustafa F. Lokhandwala ◽  
Anees Ahmad Banday
Keyword(s):  
Oxidative Stress ◽  
Mitochondrial Function ◽  
Cell Apoptosis ◽  
Protein Disulfide Isomerase ◽  
Caspase 3 ◽  
Nuclear Translocation ◽  
Proximal Tubular ◽  
Renal Proximal Tubular ◽  
Protein Disulfide ◽  
Hk2 Cells

Renal proximal tubular apoptosis plays a critical role in kidney health and disease. However, cellular molecules that trigger renal apoptosis remain elusive. Here, we evaluated the effect of inhibiting protein disulfide isomerase (PDI), a critical thioredoxin chaperone protein, on apoptosis as well as the underlying mechanisms in human renal proximal tubular (HK2) cells. HK2 cells were transfected with PDI-specific siRNA in the absence and presence of an antioxidant, tempol. PDI siRNA transfection resulted in a decrease of ~70% in PDI protein expression and enzyme activity. PDI inhibition increased caspase-3 activity and induced profound cell apoptosis. Mitochondrial function, as assessed by mitochondrial cytochrome c levels, mitochondrial membrane potential, oxygen consumption, and ATP levels, was significantly reduced in PDI-inhibited cells. Also, PDI inhibition caused nuclear factor erythroid 2-related factor 2 (Nrf2; a redox-sensitive transcription factor) cytoplasmic sequestration, decreased superoxide dismutase and glutathione- S-transferase activities, and increased oxidative stress. In PDI-inhibited cells, tempol reduced apoptosis, caspase-3 activity, and oxidative stress and also restored Nrf2 nuclear translocation and mitochondrial function. Silencing Nrf2 in the cells abrogated the beneficial effect of tempol, whereas Kelch-like ECH-associated protein 1 (an Nrf2 regulatory protein) silencing protected cells from PDI inhibitory effects. Collectively, our data indicate that PDI inhibition diminishes Nrf2 nuclear translocation, causing oxidative stress that further triggers mitochondrial dysfunction and renal cell apoptosis. This study suggests an important role for PDI in renal cell apoptosis involving Nrf2 and mitochondrial dysfunction.

scholarly journals Aldosterone promotes proximal tubular cell apoptosis: role of oxidative stress

2007 ◽  
Vol 293 (4) ◽  
pp. F1065-F1071 ◽  
Author(s):  
Hitesh Patni ◽  
Jayant T. Mathew ◽  
Liming Luan ◽  
Nicholas Franki ◽  
Praveen N. Chander ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Cytochrome C ◽  
Cell Apoptosis ◽  
Tubular Cell ◽  
Free Radical Scavengers ◽  
Dependent Manner ◽  
Proximal Tubular ◽  
Hk2 Cells ◽  
Cytosolic Cytochrome

Aldosterone has attracted significant consideration for its role in the progression of renal injury. Since apoptotic cell loss contributes to the deterioration of renal function, we examined the effect of aldosterone on tubular cell apoptosis. To determine dose and time course effect, human renal proximal tubular (HK2) cells were treated with aldosterone at different doses and for variable time periods followed by evaluation for apoptosis. To determine the role of mineralocorticoid receptors (MR) and oxidative stress, HK2 cells were treated with either vehicle or aldosterone in the presence or absence of spironolactone/antioxidants/free radical scavengers (FRS) followed by evaluation for apoptosis. The presence of MR was evaluated using RT-PCR. Reactive oxygen species (ROS) generation was evaluated using redox-sensitive dyes. Effect of aldosterone was evaluated on dephosphorylation of phospho-Bad and accumulation of cytosolic cytochrome c. Human tubular cells express MR. Aldosterone promotes tubular cell apoptosis in a dose- and time-dependent manner. This effect of aldosterone is mediated through MR and associated with generation of ROS. Antioxidants and FRS partially attenuated the proapoaptotic effect of aldosterone. Aldosterone enhanced dephosphorylation of phospho-Bad and accumulation of cytosolic cytochrome c. We conclude that aldosterone-induced tubular cell apoptosis is mediated through the activation of the mitochondrial pathway and generation of ROS.

scholarly journals Artemisinin attenuated oxidative stress and apoptosis by inhibiting autophagy in MPP+-treated SH-SY5Y cells

2021 ◽  
Vol 28 (1) ◽  
Author(s):  
Junqiang Yan ◽  
Hongxia Ma ◽  
Xiaoyi Lai ◽  
Jiannan Wu ◽  
Anran Liu ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Membrane Potential ◽  
Protein Expression ◽  
Mitochondrial Membrane Potential ◽  
Western Blotting ◽  
Cell Apoptosis ◽  
Mitochondrial Membrane ◽  
Caspase 3 ◽  
Neuroprotective Effect ◽  
Neuroprotective Effects

Abstract Background Parkinson’s disease (PD) is the second most common neurodegenerative disease after Alzheimer's disease. The oxidative stress is an important component of the pathogenesis of PD. Artemisinin (ART) has antioxidant and neuroprotective effects. The purpose of this study is to explore the neuroprotective effect of ART on 1-methyl-4-phenyliodine iodide (MPP +)-treated SH-SY5Y cells and underlying mechanism. Methods We used MPP+-treated SH-SY5Y cells to study the neuroprotective effect of ART. Cell viability was measured by MTT assay after incubating the cells with MPP+ and/or ART for 24 h. DCFH-DA was used to detect the level of intracellular reactive oxygen species (ROS), and WST-8 was used to detect the level of superoxide dismutase (SOD). The level of intracellular reduced glutathione (GSH) was detected with 5,5΄-dithiobis-(2-nitrobenzoic acid), and the level of malondialdehyde (MDA) was assessed based on the reaction of MDA and thiobarbituric acid. A mitochondrial membrane potential detection kit (JC-1) was used to detect changes in the mitochondrial membrane potential (MMP), and an Annexin V-FITC cell apoptosis kit was used to detect cell apoptosis. The expression levels of caspase-3, cleaved caspase-3 and the autophagy-related proteins LC3, beclin-1, and p62 were detected by Western blotting. In addition, to verify the change in autophagy, we used immunofluorescence to detect the expression of LC3 and p62. Results No significant cytotoxicity was observed at ART concentrations up to 40 μM. ART could significantly increase the viability of SH-SY5Y cells treated with MPP+ and reduce oxidative stress damage and apoptosis. In addition, the Western blotting and immunofluorescence results showed that MPP+ treatment could increase the protein expression of beclin1 and LC3II/LC3I and decrease the protein expression of p62, indicating that MPP+ treatment could induce autophagy. Simultaneous treatment with ART and MPP+ could decrease the protein expression of beclin1 and LC3II/LC3I and increase the protein expression of p62, indicating that ART could decrease the level of autophagy induced by MPP+. Conclusion Our results indicate that ART has a protective effect on MPP+-treated SH-SY5Y cells by the antioxidant, antiapoptotic activities and inhibition of autophagy. Our findings may provide new hope for the prevention and treatment of PD.

Selenium Modulates Oxidative Stress-Induced Cell Apoptosis in Human Myeloid HL-60 Cells Through Regulation of Calcium Release and Caspase-3 and -9 Activities

2009 ◽  
Vol 232 (1-3) ◽  
pp. 15-23 ◽  
Author(s):  
Abdülhadi Cihangir Uğuz ◽  
Mustafa Nazıroğlu ◽  
Javier Espino ◽  
Ignacio Bejarano ◽  
David González ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Cell Apoptosis ◽  
Caspase 3 ◽  
Calcium Release

scholarly journals Downregulation of Endogenous Hydrogen Sulfide Pathway Is Involved in Mitochondrion-Related Endothelial Cell Apoptosis Induced by High Salt

2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Yanfang Zong ◽  
Yaqian Huang ◽  
Siyao Chen ◽  
Mingzhu Zhu ◽  
Qinghua Chen ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Endothelial Cells ◽  
Membrane Potential ◽  
Endothelial Cell ◽  
Cell Apoptosis ◽  
Superoxide Anion ◽  
Mitochondrial Membrane ◽  
Caspase 3 ◽  
High Salt ◽  
Caspase 9

Background. The study aimed to investigate whether endogenous H2S pathway was involved in high-salt-stimulated mitochondria-related vascular endothelial cell (VEC) apoptosis.Methods. Cultured human umbilical vein endothelial cells (HUVECs) were used in the study. H2S content in the supernatant was detected. Western blot was used to detect expression of cystathionine gamma-lyase (CSE), cleaved-caspase-3, and mitochondrial and cytosolic cytochrome c (cytc). Fluorescent probes were used to quantitatively detect superoxide anion generation and measure thein situsuperoxide anion generation in HUVEC. Mitochondrial membrane pore opening, mitochondrial membrane potential, and caspase-9 activities were measured. The cell apoptosis was detected by cell death ELISA and TdT-mediated dUTP nick end labeling (TUNEL) methods.Results. High-salt treatment downregulated the endogenous VEC H2S/CSE pathway, in association with increased generation of oxygen free radicals, decreased mitochondrial membrane potential, enhanced the opening of mitochondrial membrane permeability transition pore and leakage of mitochondrial cytc, activated cytoplasmic caspase-9 and caspase-3 and subsequently induced VEC apoptosis. However, supplementation of H2S donor markedly inhibited VEC oxidative stress and mitochondria-related VEC apoptosis induced by high salt.Conclusion. H2S/CSE pathway is an important endogenous defensive system in endothelial cells antagonizing high-salt insult. The protective mechanisms for VEC damage might involve inhibiting oxidative stress and protecting mitochondrial injury.

scholarly journals Protective Effect of Standardized Extract ofGinkgo bilobaagainst Cisplatin-Induced Nephrotoxicity

2013 ◽  
Vol 2013 ◽  
pp. 1-11 ◽  
Author(s):  
Jie Song ◽  
Dan Liu ◽  
Liang Feng ◽  
Zhenhai Zhang ◽  
Xiaobin Jia ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Caspase 3 ◽  
Porcine Kidney ◽  
Beneficial Effects ◽  
Protein Levels ◽  
Ros Accumulation ◽  
Proximal Tubular ◽  
Antitumor Compound ◽  
Caspase Cascade

Cisplatin (CDDP) is a potent antitumor compound widely used with a notably side effect of nephrotoxicity inducing oxidative stress and apoptosis in kidneys. Standardized extract from the leaves of theGinkgo bilobatrees, labeled EGb761 (EGb), has been available on the market for its beneficial effects. The purpose of this study was to investigate the ability of EGb to prevent the nephrotoxic effect of CDDP and the mechanisms involved. Our results showed that EGb treatment restored the levels of creatinine, BUN, MDA, NO, SOD, CAT, GPx, and GSSG/GSH ratio in kidneys after CDDP injection. EGb also exhibited a tendency to decrease the elevated NF-κB translocation and caspase-3 protein levels in CDDP-treated kidneys. We further used a porcine kidney proximal tubular epithelial (LLC-PK1) cell line, finding that EGb accordingly inhibited ROS accumulation and iNOS increase induced by CDDPin vitro. EGb also attenuated IκB degradation and p65 NF-κB phosphorylation triggered by CDDP in LLC-PK1 cells. But EGb failed to influence CDDP-stimulated caspase cascade. These findings suggested that EGb’s renoprotective effect might be mediated by not only its well-known antioxidant activity but also the anti-inflammatory activity.

scholarly journals Sulodexide Protects Contrast-Induced Nephropathy in Sprague-Dawley Rats

2016 ◽  
Vol 40 (3-4) ◽  
pp. 621-632 ◽  
Author(s):  
Qing Zhao ◽  
Jianyong Yin ◽  
Zeyuan Lu ◽  
Yiwei Kong ◽  
Guangyuan Zhang ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Caspase 3 ◽  
Vehicle Group ◽  
Control Group ◽  
Therapeutic Effects ◽  
Protective Effects ◽  
Sprague Dawley ◽  
Contrast Induced Nephropathy ◽  
Sprague Dawley Rats ◽  
Hk2 Cells

Background: Sulodexide is a powerful antithrombin agent with reno-protective property. However, whether it has beneficial effects on Contrast-Induced Nephropathy (CIN) remained elusive. In the current study, we evaluated the therapeutic effects of Sulodexide on CIN and investigated the potential mechanisms. Methods: CIN model was induced by intravenous injection of indomethacin, followed by Ioversol and L-NAME. Sprague-Dawley rats were divided into 4 groups: control group, CIN group, CIN+vehicle group (CIN rats pretreated with vehicle) and CIN+ Sulodexide (CIN rats pretreated with Sulodexide). Sulodexide or an equivalent volume of vehicle was intravenously delivered 30 min before the induction of CIN. All the animals were sacrificed at 24h after CIN and tissues were harvested to evaluate renal injury, kidney oxidative stress and apoptosis levels. Plasma antithrombin III (ATIII) activities were also measured. Results: Compared to the untreated CIN group, improved renal function, reduced tubular injury, decreased levels of oxidative stress and apoptosis were observed in CIN rats receiving Sulodexide injection. In addition, we also found that ATIII activity was significantly higher in Sulodexide-administered group than that in vehicle-injected CIN rats. For in vitro studies, HK2 cells were exposed to Ioversol and the cyto-protective effects of Sulodexide were also determined. Sulodexide pretreatment protected HK2 cells against the cytotoxicity of Ioversol via inhibiting caspase-3 activity. Preincubation with Sulodexide could also attenuate H2O2-induced increases in ROS, apoptosis and caspase-3 levels. Conclusions: Taken together, Sulodexide could protect against CIN through activating ATIII, and inhibiting oxidative stress, inflammation and apoptosis.

scholarly journals Protein kinase C-α interaction with iHSP70 in mitochondria promotes recovery of mitochondrial function after injury in renal proximal tubular cells

2013 ◽  
Vol 305 (5) ◽  
pp. F764-F776 ◽  
Author(s):  
Grazyna Nowak ◽  
Sridharan Soundararajan ◽  
Ruben Mestril
Keyword(s):  
Mitochondrial Function ◽  
Ros Production ◽  
Atp Content ◽  
Oxidant Injury ◽  
Proximal Tubular Cells ◽  
Tubular Cells ◽  
Accelerated Proliferation ◽  
Proximal Tubular ◽  
Renal Proximal Tubular Cells ◽  
Renal Proximal Tubular

This study determined the role of PKC-α and associated inducible heat shock protein 70 (iHSP70) in the repair of mitochondrial function in renal proximal tubular cells (RPTCs) after oxidant injury. Wild-type PKC-α (wtPKC-α) and an inactive PKC-α [dominant negative dn; PKC-α] mutant were overexpressed in primary cultures of RPTCs, and iHSP70 levels and RPTC regeneration were assessed after treatment with the oxidant tert-butylhydroperoxide (TBHP). TBHP exposure increased ROS production and induced RPTC death, which was prevented by ferrostatin and necrostatin-1 but not by cyclosporin A. Overexpression of wtPKC-α maintained mitochondrial levels of active PKC-α, reduced cell death, and accelerated proliferation without altering ROS production in TBHP-injured RPTCs. In contrast, dnPKC-α blocked proliferation and monolayer regeneration. Coimmunoprecipitation and proteomic analysis demonstrated an association between inactive, but not active, PKC-α and iHSP70 in mitochondria. Mitochondrial iHSP70 levels increased as levels of active PKC-α decreased after injury. Overexpression of dnPKC-α augmented, whereas overexpression of wtPKC-α abrogated, oxidant-induced increases in mitochondrial iHSP70 levels. iHSP70 overexpression 1) maintained mitochondrial levels of phosphorylated PKC-α, 2) improved the recovery of state 3 respiration and ATP content, 3) decreased RPTC death (an effect abrogated by cyclosporine A), and 4) accelerated proliferation after oxidant injury. In contrast, iHSP70 inhibition blocked the recovery of ATP content and exacerbated RPTC death. Inhibition of PKC-α in RPTC overexpressing iHSP70 blocked the protective effects of iHSP70. We conclude that active PKC-α maintains mitochondrial function and decreases cell death after oxidant injury. iHSP70 is recruited to mitochondria in response to PKC-α dephosphorylation and associates with and reactivates inactive PKC-α, which promotes the recovery of mitochondrial function, decreases RPTC death, and improves regeneration.

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