scholarly journals Mitoquinone Protects Podocytes from Angiotensin II-Induced Mitochondrial Dysfunction and Injury via the Keap1-Nrf2 Signaling Pathway

2021 ◽  
Vol 2021 ◽  
pp. 1-22
Author(s):  
Zijing Zhu ◽  
Wei Liang ◽  
Zhaowei Chen ◽  
Jijia Hu ◽  
Jun Feng ◽  
...  

Podocyte mitochondrial dysfunction plays a critical role in the pathogenesis of chronic kidney disease (CKD). Previous studies demonstrated that excessive mitochondrial fission could lead to the overproduction of reactive oxygen species (ROS) and promote podocyte apoptosis. Therefore, the maintenance of stable mitochondrial function is a newly identified way to protect podocytes and prevent the progression of CKD. As a mitochondria-targeted antioxidant, mitoquinone (MitoQ) has been proven to be a promising agent for the prevention of mitochondrial injury in cardiovascular disease and Parkinson’s disease. The present study examined the effects of MitoQ on angiotensin II- (Ang II-) induced podocyte injury both in vivo and in vitro. Podocyte mitochondria in Ang II-infused mice exhibited morphological and functional alterations. The observed mitochondrial fragmentation and ROS production were alleviated with MitoQ treatment. In vitro, alterations in mitochondrial morphology and function in Ang II-stimulated podocytes, including mitochondrial membrane potential reduction, ROS overproduction, and adenosine triphosphate (ATP) deficiency, were significantly reversed by MitoQ. Moreover, MitoQ rescued the expression and translocation of Nrf2 (nuclear factor E2-related factor 2) and decreased the expression of Keap1 (Kelch-like ECH-associated protein 1) in Ang II-stimulated podocytes. Nrf2 knockdown partially blocked the protective effects of MitoQ on Ang II-induced mitochondrial fission and oxidative stress in podocytes. These results demonstrate that MitoQ exerts a protective effect in Ang II-induced mitochondrial injury in podocytes via the Keap1-Nrf2 signaling pathway.

Author(s):  
Yuanping Cao ◽  
Qun Wang ◽  
Caiyun Liu ◽  
Wenjun Wang ◽  
Songqing Lai ◽  
...  

Abstract Capn4 belongs to a family of calpains that participate in a wide variety of biological functions, but little is known about the role of Capn4 in cardiac disease. Here, we show that the expression of Capn4 was significantly increased in Angiotensin II (Ang II)-treated cardiomyocytes and Ang II-induced cardiac hypertrophic mouse hearts. Importantly, in agreement with the Capn4 expression patterns, the maximal calpain activity measured in heart homogenates was elevated in Ang II-treated mice, and oral coadministration of SNJ-1945 (calpain inhibitor) attenuated the total calpain activity measured in vitro. Functional assays indicated that overexpression of Capn4 obviously aggravated Ang II-induced cardiac hypertrophy, whereas Capn4 knockdown resulted in the opposite phenotypes. Further investigation demonstrated that Capn4 maintained the activation of the insulin-like growth factor (IGF)-AKT signaling pathway in cardiomyocytes by increasing c-Jun expression. Mechanistic investigations revealed that Capn4 directly bound and stabilized c-Jun, and knockdown of Capn4 increased the ubiquitination level of c-Jun in cardiomyocytes. Additionally, our results demonstrated that the antihypertrophic effect of Capn4 silencing was partially dependent on the inhibition of c-Jun. Overall, these data suggested that Capn4 contributes to cardiac hypertrophy by enhancing the c-Jun-mediated IGF-AKT signaling pathway and could be a potential therapeutic target for hypertrophic cardiomyopathy.


2020 ◽  
Vol 2020 ◽  
pp. 1-18
Author(s):  
Yan Xu ◽  
Huan Yuan ◽  
Yi Luo ◽  
Yu-Jie Zhao ◽  
Jian-Hui Xiao

Aging is an important risk factor in the occurrence of many chronic diseases. Senescence and exhaustion of adult stem cells are considered as a hallmark of aging in organisms. In this study, a senescent human amniotic mesenchymal stem cell (hAMSC) model subjected to oxidative stress was established in vitro using hydrogen peroxide. We investigated the effects of ganoderic acid D (GA-D), a natural triterpenoid compound produced from Ganoderma lucidum, on hAMSC senescence. GA-D significantly inhibited β-galactosidase (a senescence-associated marker) formation, in a dose-dependent manner, with doses ranging from 0.1 μM to 10 μM, without inducing cytotoxic side-effects. Furthermore, GA-D markedly inhibited the generation of reactive oxygen species (ROS) and the expression of p21 and p16 proteins, relieved the cell cycle arrest, and enhanced telomerase activity in senescent hAMSCs. Furthermore, GA-D upregulated the expression of phosphorylated protein kinase R- (PKR-) like endoplasmic reticulum kinase (PERK), peroxidase III (PRDX3), and nuclear factor-erythroid 2-related factor (NRF2) and promoted intranuclear transfer of NRF2 in senescent cells. The PERK inhibitor GSK2656157 and/or the NRF2 inhibitor ML385 suppressed the PERK/NRF2 signaling, which was activated by GA-D. They induced a rebound for the generation of ROS and β-galactosidase-positive cells and attenuated the differentiation capacity. These findings suggest that GA-D retards hAMSC senescence through activation of the PERK/NRF2 signaling pathway and may be a promising candidate for the discovery of antiaging agents.


Author(s):  
Jingjing Li ◽  
Qiujie Wang ◽  
Yi Yang ◽  
Chong Lei ◽  
Fan Yang ◽  
...  

Abstract Background Glutathione S-transferase zeta 1 (GSTZ1) is the penultimate enzyme in phenylalanine/tyrosine catabolism. GSTZ1 is dysregulated in cancers; however, its role in tumorigenesis and progression of hepatocellular carcinoma (HCC) is largely unknown. We aimed to assess the role of GSTZ1 in HCC and to reveal the underlying mechanisms, which may contribute to finding a potential therapeutic strategy against HCC. Methods We first analyzed GSTZ1 expression levels in paired human HCC and adjacent normal tissue specimens and the prognostic effect of GSTZ1 on HCC patients. Thereafter, we evaluated the role of GSTZ1 in aerobic glycolysis in HCC cells on the basis of the oxygen consumption rate (OCR) and extracellular acidification rate (ECAR). Furthermore, we assessed the effect of GSTZ1 on HCC proliferation, glutathione (GSH) concentration, levels of reactive oxygen species (ROS), and nuclear factor erythroid 2-related factor 2 (NRF2) signaling via gain- and loss- of GSTZ1 function in vitro. Moreover, we investigated the effect of GSTZ1 on diethylnitrosamine (DEN) and carbon tetrachloride (CCl4) induced hepatocarcinogenesis in a mouse model of HCC. Results GSTZ1 was downregulated in HCC, thus indicating a poor prognosis. GSTZ1 deficiency significantly promoted hepatoma cell proliferation and aerobic glycolysis in HCC cells. Moreover, loss of GSTZ1 function depleted GSH, increased ROS levels, and enhanced lipid peroxidation, thus activating the NRF2-mediated antioxidant pathway. Furthermore, Gstz1 knockout in mice promoted DEN/CCl4-induced hepatocarcinogenesis via activation of the NRF2 signaling pathway. Furthermore, the antioxidant agent N-acetylcysteine and NRF2 inhibitor brusatol effectively suppressed the growth of Gstz1-knockout HepG2 cells and HCC progression in Gstz1−/− mice. Conclusions GSTZ1 serves as a tumor suppressor in HCC. GSH depletion caused by GSTZ1 deficiency elevates oxidative stress, thus constitutively activating the NRF2 antioxidant response pathway and accelerating HCC progression. Targeting the NRF2 signaling pathway may be a promising therapeutic approach for this subset of HCC.


2020 ◽  
Vol 318 (3) ◽  
pp. C640-C648 ◽  
Author(s):  
Xiaodan Lu ◽  
Qiang Zhang ◽  
Li Xu ◽  
Xiuying Lin ◽  
Jianhua Fu ◽  
...  

Zinc (Zn) has antioxidant effect in different types of organs and is closely associated with human health. Endometrial receptivity is one of the most important factors in the embryo implantation and development. However, the regulatory mechanism of Zn in endometrium tissue is still unclear. In the study, we found that plasma Zn level is significantly associated with female infertility, which severely affects female reproductive health. Primary endometrial stromal cells were isolated from female endometrium and cultured in the laboratory. Zn chelator TPEN treatment reduced the expression of stem cell markers CD73, CD90, and CD105 and generated reactive oxygen species in endometrial stromal cells. However, pretreatment of Zn (zinc sulfate) is able to prevent TPEN-induced oxidative stress in vitro. By transcriptional profiling and gene ontology analysis, we found that Zn increased the cellular pluripotency signaling and extracellular matrix-receptor interaction, but reduced autophagy, endocytosis, and the nitrogen metabolism pathway. We further discovered the antioxidant function of Zn through the peroxisome proliferator-activated receptor gamma coactivator 1α/nuclear factor erythroid-2-related factor signaling pathway in endometrial stromal cells. Zn supplementation may open up an effective therapeutic approach for patients with oxidative stress-related endometrial diseases.


2015 ◽  
Vol 117 (suppl_1) ◽  
Author(s):  
Ying Xin ◽  
Yang Bai ◽  
Xin Jiang ◽  
Shanshan Zhou ◽  
Yuehui Wang ◽  
...  

Aims: Sulforaphane (SFN) as a nuclear factor erythroid 2-related factor 2 (Nrf2) activator protects the heart from, and deletion of the Nrf2 gene exaggerates, the effects of diabetes. Angiotensin II (Ang II) plays a critical role in the development of diabetic cardiomyopathy; therefore, whether SFN prevents Ang II-induced cardiomyopathy through activation of Nrf2 was examined. Methods and Results: The chronic cardiac effects of Ang II with and without SFN were examined in wild-type mice, transgenic Nrf2 knockout (Nrf2-KO) mice, and mice in which cardiac tissue overexpressed Nrf2 (Nrf2-TG). The signaling pathways of SFN-mediated Nrf2 activation were examined in H9C2 cells. Administration of a subpressor dose of Ang II to WT mice induced cardiac oxidative stress, inflammation, remodeling and dysfunction, all of which could be prevented by SFN treatment, which also up-regulated Nrf2 expression and activation. Nrf2-TG mice showed resistance and Nrf2-KO mice displayed resistance to Ang II-induced cardiomyopathy. Meanwhile, the ability of SFN to protect against Ang II-induced cardiac damage was lost in Nrf2-KO mice. Up-regulation and activation of Nrf2 by SFN is accompanied by activation of AKT, inhibition of glycogen synthase kinase (GSK)-3β, and increased nuclear accumulation of Fyn. In vitro up-regulation of Nrf2 by SFN in H9C2 cells was abolished and nuclear Fyn accumulation was increased when cells were exposed to a PI3K inhibitor or GSK-3β-specific activator. Conclusion: Nrf2 plays a central role in the prevention of Ang II-induced pathological effects, and SFN can prevent Ang II-induced cardiomyopathy through activation of Nrf2 partially via the AKT/GSK-3β/Fyn pathway.


2017 ◽  
Vol 2017 ◽  
pp. 1-11 ◽  
Author(s):  
Zhao Gao ◽  
Xinghua Chen ◽  
Kai Zhu ◽  
Ping Zeng ◽  
Guohua Ding

Numerous studies have found that angiotensin II (Ang II) participates in podocyte apoptosis and exacerbates progression of end-stage kidney disease (ESKD). However, its underlying mechanism remains largely unexplored. As a homolog of Drosophila disabled (Dab) protein, Dab1 plays a vital role in cytoskeleton, neuronal migration, and proliferation. In the present study, our data revealed that Ang II-infused rats developed hypertension, proteinuria, and podocyte injury accompanied by Dab1 phosphorylation and increased reelin expression in kidney. Moreover, Ang II induced podocyte apoptosis in vitro. Dab1 phosphorylation and reelin expression in podocytes were increased after exposure to Ang II. Conversely, Dab1 small interfering RNA (siRNA) exerted protective effects on Ang II-induced podocyte apoptosis, resulting in decreased p38 phosphorylation and reelin expression. These results indicated that Dab1 mediated Ang II-induced podocyte apoptosis via p38 signaling pathway.


2017 ◽  
Vol 41 (5) ◽  
pp. 2004-2015 ◽  
Author(s):  
Zeng-xiang Dong ◽  
Lin Wan ◽  
Ren-jun Wang ◽  
Yuan-qi Shi ◽  
Guang-zhong Liu ◽  
...  

Background/Aims: Flavonol (–)-epicatechin (EPI) is present in high amounts in cocoa and tea products, and has been shown to exert beneficial effects on the cardiovascular system. However, the precise mechanism of EPI on cardiomyocyte hypertrophy has not yet been determined. In this study, we examined whether EPI could inhibit cardiac hypertrophy. Methods: We utilised cultured neonatal mouse cardiomyocytes and mice for immunofluorescence, immunochemistry, qRT-PCR, and western blot analyses. Results: 1µM EPI significantly inhibited 1µM angiotensin II (Ang II)-induced increase of cardiomyocyte size, as well as the mRNA and protein levels of ANP, BNP and β-MHC in vitro. The effects of EPI were accompanied with an up-regulation of SP1 and SIRT1, and were abolished by SP1 inhibition. Up-regulation of SP1 could block Ang II-induced increase in cardiomyocyte size, as well as the mRNA and protein levels of ANP, BNP and β-MHC, and increase the protein levels of SIRT1 in vitro. Moreover, 1 mg/kg body weight/day EPI significantly inhibited mouse cardiac hypertrophy induced by Ang II, which could be eliminated by SP1 inhibition in vivo. Conclusion: Our data indicated that EPI inhibited AngII-induced cardiac hypertrophy by activating the SP1/SIRT1 signaling pathway.


2020 ◽  
pp. 074823372097942
Author(s):  
Guangtao Yang ◽  
Yingping Xiang ◽  
Wei Zhou ◽  
Xiaohuan Zhong ◽  
Yanfang Zhang ◽  
...  

The bromoalkane, 1-bromopropane (1-BP), may damage the reproductive system though oxidative stress, while the transcription factor nuclear factor erythroid 2-related factor 2 (Nrf2) plays an important role in regulating intracellular antioxidant levels against oxidative stress. This study explored the role of oxidative stress and the Nrf2 signaling pathway in mediating the reproductive toxicity of 1-BP using the ovarian carcinoma cell line OVCAR-3 as an in vitro model of the human ovary. OVCAR-3 cells were treated with 1, 5, 10 and 15 mM 1-BP. After 24 h, the cellular reactive oxygen species and malondialdehyde concentrations significantly increased, while the superoxide dismutase activity decreased; translocation of Nrf2 from the cytosol to the nucleus as well as downstream protein expression of Nrf2-regulated genes heme oxygenase-1 and Bcl-2 was inhibited. Apoptosis was also observed, accompanied by increased caspase-3 and caspase-9 activity. The antioxidant vitamin C alleviated 1-BP-induced apoptosis by inhibiting caspase activity activating the Nrf2 signaling pathway. These findings suggested that 1-BP induced oxidative stress and apoptosis in OVCAR-3 cells through inactivation of Nrf2 signaling.


2021 ◽  
Vol 12 ◽  
Author(s):  
Hanyu Yang ◽  
Lu Wang ◽  
Caixia Zang ◽  
Xu Yang ◽  
Xiuqi Bao ◽  
...  

Mitochondrial dysfunction is involved in the pathogenesis of Parkinson’s disease (PD). Mitochondrial morphology is dynamic and precisely regulated by mitochondrial fission and fusion machinery. Aberrant mitochondrial fragmentation, which can result in cell death, is controlled by the mitochondrial fission protein, dynamin-related protein 1 (Drp1). Our previous results demonstrated that FLZ could correct mitochondrial dysfunction, but the effect of FLZ on mitochondrial dynamics remain uncharacterized. In this study, we investigated the effect of FLZ and the role of Drp1 on 1-methyl-4-phenylpyridinium (MPP+)–induced mitochondrial fission in neurons. We observed that FLZ blocked Drp1, inhibited Drp1 enzyme activity, and reduced excessive mitochondrial fission in cultured neurons. Furthermore, by inhibiting mitochondrial fission and ROS production, FLZ improved mitochondrial integrity and membrane potential, resulting in neuroprotection. FLZ curtailed the reduction of synaptic branches of primary cultured dopaminergic neurons caused by MPP+ exposure, reduced abnormal fission, restored normal mitochondrial distribution in neurons, and exhibited protective effects on dopaminergic neurons. The in vitro research results were validated using an MPTP-induced PD mouse model. The in vivo results revealed that FLZ significantly reduced the mitochondrial translocation of Drp1 in the midbrain of PD mice, which, in turn, reduced the mitochondrial fragmentation in mouse substantia nigra neurons. FLZ also protected dopaminergic neurons in PD mice and increased the dopamine content in the striatum, which improved the motor coordination ability of the mice. These findings elucidate this newly discovered mechanism through which FLZ produces neuroprotection in PD.


Circulation ◽  
2020 ◽  
Vol 142 (Suppl_3) ◽  
Author(s):  
Yoshihiro Uchikado ◽  
Yoshiyuki Ikeda ◽  
Yuichi Sasaki ◽  
Yuichi Akasaki ◽  
Mitsuru Ohishi

Introduction: Angiotensin II (Ang II) causes vascular senescence by damaging mitochondria that undergo quality control by mitochondrial dynamics and mitophagy. We examined whether and how AngII type I receptor (AT1R) signal regulates mitochondrial dynamics and mitophagy in the etiology of vascular senescence. Methods: We used vascular smooth muscle cells (VSMC) and C57BL6 (WT), apolipoprotein E deficient (ApoE KO) and the double knockout of ApoE and AT1R mice. Results: Administration of Ang II to VSMC forced mitochondria to fission and induced cellular senescence and mitochondrial dysfunction, which were restored by inhibition of fission by use of Mdivi-1. Treatment of ox-LDL also induced cellular senescence accompanied by excessive mitochondrial fission through phosphorylation of Drp1 at Ser616 and mitochondrial dysfunction. These alterations were ameliorated by inhibition of AT1R signal, suggesting that AT1R signal inhibition may contribute anti-cellular senescence by modification of mitochondrial dynamics. AT1R signal inhibition also induced mitophagy assessed by electron microscopy and immunohistochemistry of LAMP2 and TOMM20. AT1R inhibition-induced mitophagy was not affected by Atg7 Knockdown, whereas it was diminished by Rab9 knockdown. Immunohistochemistry showed TOMM20 dots were co-localized to LAMP2 and Rab9 but not LC3. These results suggest that AT1R signal induces mitophagy derived from Rab9-dependent alternative autophagy. Treatment of ox-LDL activated Ras, Raf and MEK, and AT1R inhibition inactivated them. Inhibition of Ras/Raf/MEK decreased excessive mitochondrial fission and induced mitophagy, suggesting that AT1R signal followed by Ras/Raf/MEK pathway modulates both mitochondrial dynamics and mitophagy. The degree of arterial senescence and atherosclerosis, Drp1 expression in mitochondrial fraction and oxidative stress in artery were higher and the number of mitophagy, fused mitochondria and its function were lower in ApoE KO than those of WT mice. AT1R KO to ApoE KO attenuated these adverse effects of ApoE KO. Conclusions: Inhibition of AT1R signal contributes vascular senescence through modification of mitochondrial dynamics and mitophagy by inactivation of Ras/Raf/MEK pathway.


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