scholarly journals Dab1 Contributes to Angiotensin II-Induced Apoptosis via p38 Signaling Pathway in Podocytes

2017 ◽  
Vol 2017 ◽  
pp. 1-11 ◽  
Author(s):  
Zhao Gao ◽  
Xinghua Chen ◽  
Kai Zhu ◽  
Ping Zeng ◽  
Guohua Ding
Keyword(s):  
Angiotensin Ii ◽  
Signaling Pathway ◽  
Underlying Mechanism ◽  
Vital Role ◽  
Protective Effects ◽  
Ang Ii ◽  
Induced Apoptosis ◽  
End Stage ◽  
Interfering Rna

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.

scholarly journals Angiotensin II down-regulates nephrin–Akt signaling and induces podocyte injury: role of c-Abl

2016 ◽  
Vol 27 (1) ◽  
pp. 197-208 ◽  
Author(s):  
Qian Yang ◽  
Yiqiong Ma ◽  
Yipeng Liu ◽  
Wei Liang ◽  
Xinghua Chen ◽  
...  
Keyword(s):  
Angiotensin Ii ◽  
Vital Role ◽  
Sh2 Domain ◽  
Renal Diseases ◽  
Ang Ii ◽  
Podocyte Injury ◽  
Nonreceptor Tyrosine Kinase ◽  
Inositol Phosphatase ◽  
Interfering Rna

Recent studies have shown that nephrin plays a vital role in angiotensin II (Ang II)–induced podocyte injury and thus contributes to the onset of proteinuria and the progression of renal diseases, but its specific mechanism remains unclear. c-Abl is an SH2/SH3 domain–containing nonreceptor tyrosine kinase that is involved in cell survival and regulation of the cytoskeleton. Phosphorylated nephrin is able to interact with molecules containing SH2/SH3 domains, suggesting that c-Abl may be a downstream molecule of nephrin signaling. Here we report that Ang II–infused rats developed proteinuria and podocyte damage accompanied by nephrin dephosphorylation and minimal interaction between nephrin and c-Abl. In vitro, Ang II induced podocyte injury and nephrin and Akt dephosphorylation, which occurred in tandem with minimal interaction between nephrin and c-Abl. Moreover, Ang II promoted c-Abl phosphorylation and interaction between c-Abl and SH2 domain–containing 5′-inositol phosphatase 2 (SHIP2). c-Abl small interfering RNA (siRNA) and STI571 (c-Abl inhibitor) provided protection against Ang II–induced podocyte injury, suppressed the Ang II-induced c-Abl–SHIP2 interaction and SHIP2 phosphorylation, and maintained a stable level of nephrin phosphorylation. These results indicate that c-Abl is a molecular chaperone of nephrin signaling and the SHIP2-Akt pathway and that the released c-Abl contributes to Ang II–induced podocyte injury.

scholarly journals Isorhynchophylline Protects PC12 Cells Against Beta-Amyloid-Induced Apoptosis via PI3K/Akt Signaling Pathway

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Yan-Fang Xian ◽  
Zhi-Xiu Lin ◽  
Qing-Qiu Mao ◽  
Jian-Nan Chen ◽  
Zi-Ren Su ◽  
...  
Keyword(s):  
Signaling Pathway ◽  
Pc12 Cells ◽  
Molecular Mechanisms ◽  
Glycogen Synthase ◽  
Neuroprotective Effect ◽  
Protective Action ◽  
Protective Effects ◽  
Phosphorylated Akt ◽  
Induced Apoptosis

The neurotoxicity of amyloid-β(Aβ) has been implicated as a critical cause of Alzheimer’s disease. Isorhynchophylline (IRN), an oxindole alkaloid isolated fromUncaria rhynchophylla,exerts neuroprotective effect againstAβ25–35-induced neurotoxicityin vitro. However, the exact mechanism for its neuroprotective effect is not well understood. The present study aimed to investigate the molecular mechanisms underlying the protective action of IRN againstAβ25–35-induced neurotoxicity in cultured rat pheochromocytoma (PC12) cells. Pretreatment with IRN significantly increased the cell viability, inhibited the release of lactate dehydrogenase and the extent of DNA fragmentation inAβ25–35-treated cells. IRN treatment was able to enhance the protein levels of phosphorylated Akt (p-Akt) and glycogen synthase kinase-3β(p-GSK-3β). Lithium chloride blockedAβ25–35-induced cellular apoptosis in a similar manner as IRN, suggesting that GSK-3βinhibition was involved in neuroprotective action of IRN. Pretreatment with LY294002 completely abolished the protective effects of IRN. Furthermore, IRN reversedAβ25–35-induced attenuation in the level of phosphorylated cyclic AMP response element binding protein (p-CREB) and the effect of IRN could be blocked by the PI3K inhibitor. These experimental findings unambiguously suggested that the protective effect of IRN againstAβ25–35-induced apoptosis in PC12 cells was associated with the enhancement of p-CREB expression via PI3K/Akt/GSK-3βsignaling pathway.

Capn4 aggravates angiotensin II-induced cardiac hypertrophy by activating the IGF-AKT signaling pathway

2021 ◽  
Author(s):  
Yuanping Cao ◽  
Qun Wang ◽  
Caiyun Liu ◽  
Wenjun Wang ◽  
Songqing Lai ◽  
...  
Keyword(s):  
Angiotensin Ii ◽  
Cardiac Hypertrophy ◽  
Signaling Pathway ◽  
Expression Patterns ◽  
Akt Signaling ◽  
Calpain Inhibitor ◽  
Ang Ii ◽  
Akt Signaling Pathway ◽  
Calpain Activity

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.

scholarly journals Alpha-Asarone Protects Endothelial Cells from Injury by Angiotensin II

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Hai-Xia Shi ◽  
Jiajun Yang ◽  
Tao Yang ◽  
Yong-Liang Xue ◽  
Jun Liu ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Endothelial Cells ◽  
Angiotensin Ii ◽  
Cell Injury ◽  
Fluorescent Dyes ◽  
Umbilical Vein ◽  
Protective Effects ◽  
Ang Ii ◽  
Versus Model

α-Asarone is the major therapeutical constituent ofAcorus tatarinowiiSchott. In this study, the potential protective effects ofα-asarone against endothelial cell injury induced by angiotensin II were investigatedin vitro. The EA.hy926 cell line derived from human umbilical vein endothelial cells was pretreated withα-asarone (10, 50, 100 µmol/L) for 1 h, followed by coincubation with Ang II (0.1 µmol/L) for 24 h. Intracellular nitric oxide (NO) and reactive oxygen species (ROS) were detected by fluorescent dyes, and phosphorylation of endothelial nitric oxide synthase (eNOS) atSer1177was determined by Western blotting.α-Asarone dose-dependently mitigated the Ang II-induced intracellular NO reduction (P<0.01versus model) and ROS production (P<0.01versus model). Furthermore, eNOS phosphorylation (Ser1177) by acetylcholine was significantly inhibited by Ang II, while pretreatment for 1 h withα-asarone partially prevented this effect (P<0.05versus model). Additionally, cell viability determined by the MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] assay (105~114.5% versus control,P>0.05) was not affected after 24 h of incubation withα-asarone at 1–100 µmol/L. Therefore,α-asarone protects against Ang II-mediated damage of endothelial cells and may be developed to prevent injury to cardiovascular tissues.

Hexarelin protects rat cardiomyocytes from angiotensin II-induced apoptosis in vitro

2004 ◽  
Vol 286 (3) ◽  
pp. H1063-H1069 ◽  
Author(s):  
Jin-Jiang Pang ◽  
Rong-Kun Xu ◽  
Xiang-Bin Xu ◽  
Ji-Min Cao ◽  
Chao Ni ◽  
...  
Keyword(s):  
Heart Failure ◽  
Angiotensin Ii ◽  
Caspase 3 ◽  
Cardiomyocyte Apoptosis ◽  
Protective Effects ◽  
Ang Ii ◽  
Growth Hormone Secretagogue Receptor ◽  
Growth Hormone Secretagogue ◽  
Rat Cardiomyocytes ◽  
Induced Apoptosis

Loss of cardiomyocytes by apoptosis is proposed to cause heart failure. Angiotensin II (ANG II), an important neurohormonal factor during heart failure, can induce cardiomyocyte apoptosis. Inasmuch as hexarelin has been reported to have protective effects in this process, we examined whether hexarelin can prevent cardiomyocytes from ANG II-induced cell death. Cultured cardiomyocytes from neonatal rats were stimulated with ANG II. Apoptosis was evaluated using fluorescence microscopy, TdT-mediated dUTP nick-end labeling (TUNEL) method, flow cytometry, DNA laddering, and analysis of cell viability by (3,4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT). It was found that incubation with 0.1 μmol/l ANG II for 48 h increased cardiomyocyte apoptosis. Administration of 0.1 μmol/l hexarelin significantly decreased this ANG II-induced apoptosis and DNA fragmentation and increased myocyte viability. To further investigate the underlying mechanisms, caspase-3 activity assay and mRNA expression of Bax, Bcl-2, and growth hormone secretagogue receptor (GHS-R; the supposed hexarelin binding site) were examined. GHS-R mRNA was abundantly expressed in cardiomyocytes and was upregulated after administration of hexarelin. These results suggest that hexarelin abates cardiomyocytes from ANG II-induced apoptosis possibly via inhibiting the increased caspase-3 activity and Bax expression induced by ANG II and by increasing the expression of Bcl-2, which is depressed by ANG II. Whether the upregulated expression of GHS-R induced by hexarelin is associated with this antiapoptotic effect deserves further investigation.

Abstract 152: IL-10 Inhibits Angiotensin II-induced Pathological Autophagy in Myocardium.

2014 ◽  
Vol 115 (suppl_1) ◽  
Author(s):  
Suresh K Verma ◽  
Prasanna Krishnamurthy ◽  
Tatiana Abramova ◽  
Garikipati Srikanth ◽  
Mohsin Khan ◽  
...  
Keyword(s):  
Angiotensin Ii ◽  
Fluorescent Protein ◽  
Heart Function ◽  
Cardiac Cells ◽  
Neonatal Rat ◽  
Autophagic Flux ◽  
Protective Effects ◽  
Ang Ii ◽  
Akt Inhibitor

Background: In heart, persistent pressure overload causes pathological autophagy leading to cardiac cell death and heart failure. The role IL-10, a pleiotropic anti-inflammatory cytokine, on pathological autophagy is largely unknown. Here we hypothesized that IL-10 inhibits stress-induced pathological autophagy and therefore attenuates cardiac cells death and improve heart function. Method and Results: Cardiac stress was induced in C57 BL/6 mice by Angiotensin II treatment (Ang II-1.2mg.kg b.wt/day for 28 days) using mini osmotic pumps. Ang II treatment markedly induced autophagy in mice as measured by electron microscopy (autophagosome numbers) and Western blotting (Becline1 and LC3II proteins expression). Interestingly, systemic recombinant mouse IL-10 administration markedly inhibited Ang II-induced autophagy. To further understand the mechanism of IL-10 protection, neonatal rat ventricular myocytes (NRCM) were transfected with monomeric Red Fluorescent Protein-Enhanced Green Fluorescent Protein (mRFP-EGFP) tandem fluorescent-tagged LC3 (tfLC3) adenovirus (to measure autophagic flux) and then treated with AngII (1μM) and/or IL-10 (20ng/mL), in vitro. Ang II treatment significantly increased the numbers of both yellow (merged EGFP and mRFP signals) and red puncta, indicating active formation of both autophagosomes and autolysosomes, however, this flux was strongly inhibited by IL-10. Furthermore, Ang II significantly increased the Beclin1 and LC3II proteins expression, which was markedly reduced by IL-10 as measured by Western blot analysis. In addition, Ang II-inhibited AKT signaling (anti-autophagic signaling component) was strongly enhanced by IL-10. Ang II-induced autophagic signaling was mimicked by AKT inhibitor, suggesting AKT as the downstream target of IL-10 effects. Conclusion: Inhibition of pathological autophagy is a novel mechanism for cardio-protective effects of IL-10.

scholarly journals Adiponectin Suppresses Angiotensin II-Induced Inflammation and Cardiac Fibrosis through Activation of Macrophage Autophagy

Endocrinology ◽  
2014 ◽  
Vol 155 (6) ◽  
pp. 2254-2265 ◽  
Author(s):  
Guan-Ming Qi ◽  
Li-Xin Jia ◽  
Yu-Lin Li ◽  
Hui-Hua Li ◽  
Jie Du
Keyword(s):  
Angiotensin Ii ◽  
Protein Kinase ◽  
Cardiac Fibrosis ◽  
Inflammatory Responses ◽  
Smooth Muscle Actin ◽  
Underlying Mechanism ◽  
Nuclear Factor Κb ◽  
Ang Ii ◽  
Compound C

Previous studies have indicated that adiponectin (APN) protects against cardiac remodeling, but the underlying mechanism remains unclear. The present study aimed to elucidate how APN regulates inflammatory responses and cardiac fibrosis in response to angiotensin II (Ang II). Male APN knockout (APN KO) mice and wild-type (WT) C57BL/6 littermates were sc infused with Ang II at 750 ng/kg per minute. Seven days after Ang II infusion, both APN KO and WT mice developed equally high blood pressure levels. However, APN KO mice developed more severe cardiac fibrosis and inflammation compared with WT mice. This finding was demonstrated by the up-regulation of collagen I, α-smooth muscle actin, IL-1β, and TNF-α and increased macrophage infiltration in APN KO mice. Moreover, there were substantially fewer microtubule-associated protein 1 light chain 3-positive autophagosomes in macrophages in the hearts of Ang II-infused APN KO mice. Additional in vitro studies also revealed that globular APN treatment induced autophagy, inhibited Ang II-induced nuclear factor-κB activity, and enhanced the expression of antiinflammatory cytokines, including IL-10, macrophage galactose N-acetyl-galactosamine specific lectin 2, found in inflammatory zone 1, and type-1 arginase in macrophages. In contrast, APN-induced autophagy and antiinflammatory cytokine expression was diminished in Atg5-knockdown macrophages or by Compound C, an inhibitor of adenosine 5′-monophosphate-activated protein kinase. Our study indicates that APN activates macrophage autophagy through the adenosine 5′-monophosphate-activated protein kinase pathway and suppresses Ang II-induced inflammatory responses, thereby reducing the extent of cardiac fibrosis.

scholarly journals (–)-Epicatechin Suppresses Angiotensin II-induced Cardiac Hypertrophy via the Activation of the SP1/SIRT1 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 ◽  
...  
Keyword(s):  
Angiotensin Ii ◽  
Cardiac Hypertrophy ◽  
Signaling Pathway ◽  
Cardiomyocyte Hypertrophy ◽  
Ang Ii ◽  
Beneficial Effects ◽  
Protein Levels ◽  
Qrt Pcr

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.

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 ◽  
...  
Keyword(s):  
Angiotensin Ii ◽  
Mitochondrial Dysfunction ◽  
Signaling Pathway ◽  
Mitochondrial Fission ◽  
Mitochondrial Morphology ◽  
Related Factor ◽  
Ang Ii ◽  
Mitochondrial Injury ◽  
Nrf2 Signaling Pathway

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.

scholarly journals Bilirubin Restrains the Anticancer Effect of Vemurafenib on BRAF-Mutant Melanoma Cells Through ERK-MNK1 Signaling

2021 ◽  
Vol 11 ◽  
Author(s):  
Yufan Tan ◽  
Xiaoyu Zhong ◽  
Xizhi Wen ◽  
Leyi Yao ◽  
Zhenlong Shao ◽  
...  
Keyword(s):  
Signaling Pathway ◽  
Animal Experiments ◽  
Underlying Mechanism ◽  
Melanoma Cells ◽  
Anticancer Effect ◽  
Braf Mutations ◽  
Melanoma Patients ◽  
Induced Apoptosis ◽  
Braf Mutant

Melanoma, the most threatening cancer in the skin, has been considered to be driven by the carcinogenic RAF-MEK1/2-ERK1/2 signaling pathway. This signaling pathway is usually mainly dysregulated by mutations in BRAF or RAS in skin melanomas. Although inhibitors targeting mutant BRAF, such as vemurafenib, have improved the clinical outcome of melanoma patients with BRAF mutations, the efficiency of vemurafenib is limited in many patients. Here, we show that blood bilirubin in patients with BRAF-mutant melanoma treated with vemurafenib is negatively correlated with clinical outcomes. In vitro and animal experiments show that bilirubin can abrogate vemurafenib-induced growth suppression of BRAF-mutant melanoma cells. Moreover, bilirubin can remarkably rescue vemurafenib-induced apoptosis. Mechanically, the activation of ERK-MNK1 axis is required for bilirubin-induced reversal effects post vemurafenib treatment. Our findings not only demonstrate that bilirubin is an unfavorable for patients with BRAF-mutant melanoma who received vemurafenib treatment, but also uncover the underlying mechanism by which bilirubin restrains the anticancer effect of vemurafenib on BRAF-mutant melanoma cells.

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