Abstract 14664: SIRT3 Protects Cardiomyocytes From Doxorubicin-induced Mitochondrial Damage and Cell-death by Activating Opa1

Circulation ◽  
2014 ◽  
Vol 130 (suppl_2) ◽  
Author(s):  
Sadhana Samant ◽  
Vinodkumar Pillai ◽  
Don Wolfgeher ◽  
Mahesh Gupta

Introduction: The anti-cancer drug therapy with doxorubicin (Dox) is known to produce cardiomyopathy associated with fragmentation of mitochondria and excess production of reactive oxygen species (ROS). Sirtuin3 (SIRT3), a mitochondrial deacetylase regulates many mitochondrial functions including energy production, ROS synthesis and cell-death. A role of SIRT3 in regulating the aging process and aging-associated diseases like heart failure, cancer and diabetes has been also documented. This study was undertaken to investigate whether SIRT3 can protect cardiomyocytes from Dox-induced mitochondrial damage and cell-death. Methods and Results: Neonatal rat cardiomyocytes were over expressed with a vector synthesizing SIRT3 or a mock vector. Cells were treated with Dox (100nM) for 72 hours and cell-death was analyzed by measuring TUNEL-positive nuclei, ROS synthesis and expression of apoptotic markers by the western blotting. There was marked reduction of TUNEL-positive nuclei, ROS levels and expression of apoptotic markers such as Bax, Bim and FasL in SIRT3 over expressing cells, compared to control cells received the mock vector. Confocal imaging of myocytes revealed that Dox-treatment caused swelling and fragmentation of mitochondria in control cells, but not in cells over expressed with SIRT3. To understand the mechanism involved in SIRT3-mediated protection of mitochondria we analyzed acetylation of proteins involved in regulating mitochondrial fusion-fission dynamics. We found that OPA1 (optic atrophy-1), an essential inner membrane fusion protein, was hyper-acetylated in Dox-treated cells, leading to its reduced GTPase activity. SIRT3 was capable of deacetylating and augmenting GTPase activity of OPA1 both in vitro and in vivo assay conditions. Furthermore, by studying OPA1 null cells we found that it is necessary for SIRT3-mediated protection of cardiomyocytes from mitochondrial damage and cell-death. Conclusions: These results indicated that SIRT3-dependent activation of OPA1 contributes to preservation of mitochondrial population and protection of cardiomyocytes from Dox-mediated cell-death. We believe that SIRT3 could be utilized as a therapeutic target for treatment of Dox-induced cardiomyopathy of the heart.

2019 ◽  
Vol 40 (Supplement_1) ◽  
Author(s):  
A Belhadef ◽  
M Ribeiro ◽  
M Mazevet ◽  
M Laudette ◽  
B Crozatier ◽  
...  

Abstract Introduction Doxorubicin (Dox) is an anthracycline commonly used to treat many types of cancer; unfortunately this chemotherapeutic agent induces many side effects such as cardiotoxicity leading to dilated cardiomyopathy (DCM). The cardiotoxicity of Dox has been related to reactive oxygen species generation, DNA intercalation, topoisomerase II inhibition and bioenergetics alterations leading to cardiomyocyte death. Objective Nowadays the challenge is to find new treatment options aiming at reducing Dox cardiotoxicity. Epac (exchange protein directly activated by cAMP) signaling could be worth investigating as Epac activates small G proteins which are known to be involved in Dox-induced cardiotoxicity. Methods We investigated the time/dose-dependent Dox effect on Epac signaling in both in vivo mice model (C57Bl63/ Knock-out Epac1 mice, iv injections, 12mg/kg cumulative dose) and in vitro (primary culture of neonatal rat cardiomyocytes (NRVM, 24h, Dox 1μM). Results In vivo, Dox-treated mice developed a DCM associated with Ca2+ homeostasis dysfunction (increase of Ca2+ waves and Ca2+ leaks). In vitro, as measured by flow cytometry and western blot, Dox (1μM) induced DNA damages and cell death in NRVM. This cell death is associated with apoptotic features including mitochondrial membrane permeabilization, caspase activation and cell size reduction. The inhibition of Epac1 (ESI09, CE3F4) decreased Dox-induced DNA damage, loss of mitochondrial membrane potential, apoptosis and finally cardiomyocyte death. Moreover, in vivo, Epac1 KO mice were protected against Dox-induced cardiotoxicity by unaltered cardiac function (no DCM) and calcium homeostasis at 15 weeks post-treatment. Conclusion Inhibition of Epac1 could be a valuable therapeutic strategy to limit Dox-induced cardiomyopathy during cancer chemotherapy. Indeed, preliminary data show also that preventing Dox-induced cardiotoxicity, the inhibition of Epac1 can also potentiate cancerous cells death. Acknowledgement/Funding Labex Lermit (ANR 0033), Torino and Inserm


Pharmacology ◽  
2021 ◽  
Vol 106 (3-4) ◽  
pp. 189-201
Author(s):  
Shigang Qiao ◽  
Wen-jie Zhao ◽  
Huan-qiu Li ◽  
Gui-zhen Ao ◽  
Jian-zhong An ◽  
...  

Aim: It has been reported that necrostatin-1 (Nec-1) is a specific necroptosis inhibitor that could attenuate programmed cell death induced by myocardial ischemia/reperfusion (I/R) injury. This study aimed to observe the effect and mechanism of novel Nec-1 analog (Z)-5-(3,5-dimethoxybenzyl)-2-imine-1-methylimidazolin-4-1 (DIMO) on myocardial I/R injury. Methods: Male SD rats underwent I/R injury with or without different doses of DIMO (1, 2, or 4 mg/kg) treatment. Isolated neonatal rat cardiomyocytes were subjected to oxygen-glucose deprivation/reoxygenation (OGD/R) treatment with or without DIMO (0.1, 1, 10, or 100 μM). Myocardial infarction was measured by TTC staining. Cardiomyocyte injury was assessed by lactate dehydrogenase assay (LDH) and flow cytometry. Receptor-interacting protein 1 kinase (RIP1K) and autophagic markers were detected by co-immunoprecipitation and Western blotting analysis. Molecular docking of DIMO into the ATP binding site of RIP1K was performed using GLIDE. Results: DIMO at doses of 1 or 2 mg/kg improved myocardial infarct size. However, the DIMO 4 mg/kg dose was ineffective. DIMO at the dose of 0.1 μM decreased LDH leakage and the ratio of PI-positive cells followed by OGD/R treatment. I/R or OGD/R increased RIP1K expression and in its interaction with RIP3K, as well as impaired myocardial autophagic flux evidenced by an increase in LC3-II/I ratio, upregulated P62 and Beclin-1, and activated cathepsin B and L. In contrast, DIMO treatment reduced myocardial cell death and reversed the above mentioned changes in RIP1K and autophagic flux caused by I/R and OGD/R. DIMO binds to RIP1K and inhibits RIP1K expression in a homology modeling and ligand docking. Conclusion: DIMO exerts cardioprotection against I/R- or OGD/R-induced injury, and its mechanisms may be associated with the reduction in RIP1K activation and restoration impaired autophagic flux.


2013 ◽  
Vol 113 (suppl_1) ◽  
Author(s):  
Jifen Li ◽  
Sarah Carrante ◽  
Roslyn Yi ◽  
Frans van Roy ◽  
Glenn L. Radice

Introduction: Mammalian heart possesses regenerative potential immediately after birth and lost by one week of age. The mechanisms that govern neonatal cardiomyocyte proliferation and regenerative capacity are poorly understood. Recent reports indicate that Yap-Tead transcriptional complex is necessary and sufficient for cardiomyocyte proliferation. During postnatal development, N-cadherin/catenin adhesion complex becomes concentrated at termini of cardiomyocytes facilitating maturation of a specialized intercellular junction structure, the intercalated disc (ICD). This process coincides with the time cardiomyocytes exit cell cycle soon after birth. Hypothesis: We hypothesize that coincident with maturation of ICD α-catenins sequester transcriptional coactivator Yap in cytosol thus preventing activation of genes critical for cardiomyocyte proliferation. Methods: We deleted αE-catenin / αT-catenin genes (α-cat DKO) in perinatal mouse heart and knockdown (KD) α-catenins in neonatal rat cardiomyocytes to study functional impact of α-catenins ablation on ICD maturation. Results: We previously demonstrated that adult α-cat DKO mice exhibited decrease in scar size and improved function post myocardial infarction. In present study, we investigated function of α-catenins during postnatal heart development. We found increase in the number of Yap-positive nuclei (58.7% in DKO vs. 35.8 % in WT, n=13, p<0.001) and PCNA (53.9% in DKO vs. 47.8%, n=8, p<0.05) at postnatal day 1 and day 7 of α-cat DKO heart, respectively. Loss of α-catenins resulted in reduction in N-cadherin at ICD at day 14. We observed an increase number of mononucleated myocytes and decrease number of binucleated myocytes in α-cat DKO compared to controls. Using siRNA KD, we were able to replicate α-cat DKO proliferative phenotype in vitro. The number of BrdU-positive cells was decreased in α-cat KD after interfering with Yap expression (2.91% in α-cat KD vs. 2.02% in α-cat/Yap KD, n>2500 cells, p<0.05), suggesting α-catenins regulate cell proliferation through Yap in neonatal cardiomyocytes. Conclusion: Our results suggest that maturation of ICD regulates α-catenin-Yap interactions in cytosol, thus preventing Yap nuclear accumulation and cardiomyocyte proliferation.


2018 ◽  
Vol 38 (5) ◽  
Author(s):  
Zheng Wang ◽  
Lu Gao ◽  
Lili Xiao ◽  
Lingyao Kong ◽  
Huiting Shi ◽  
...  

Bakuchiol (Bak), a monoterpene phenol isolated from the seeds of Psoralea corylifolia, has been widely used to treat a large variety of diseases in both Indian and Chinese folkloric medicine. However, the effects of Bak on cardiac hypertrophy remain unclear. Therefore, the present study was designed to determine whether Bak could alleviate cardiac hypertrophy. Mice were subjected to aortic banding (AB) to induce cardiac hypertrophy model. Bak of 1 ml/100 g body weight was given by oral gavage once a day from 1 to 8 weeks after surgery. Our data demonstrated for the first time that Bak could attenuate pressure overload-induced cardiac hypertrophy and could attenuate fibrosis and the inflammatory response induced by AB. The results further revealed that the effect of Bak on cardiac hypertrophy was mediated by blocking the activation of the NF-κB signaling pathway. In vitro studies performed in neonatal rat cardiomyocytes further proved that the protective effect of Bak on cardiac hypertrophy is largely dependent on the NF-κB pathway. Based on our results, Bak shows profound potential for its application in the treatment of pathological cardiac hypertrophy, and we believe that Bak may be a promising therapeutic candidate to treat cardiac hypertrophy and heart failure.


Biomolecules ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1667
Author(s):  
Jian-Hong Lin ◽  
Kun-Ta Yang ◽  
Pei-Ching Ting ◽  
Yu-Po Luo ◽  
Ding-Jyun Lin ◽  
...  

Myocardial ischemia/reperfusion (I/R) injury has been associated with ferroptosis, which is characterized by an iron-dependent accumulation of lipid peroxide to lethal levels. Gossypol acetic acid (GAA), a natural product taken from the seeds of cotton plants, prevents oxidative stress. However, the effects of GAA on myocardial I/R-induced ferroptosis remain unclear. This study investigated the ability of GAA to attenuate I/R-induced ferroptosis in cardiomyocytes along with the underlying mechanisms in a well-established rat model of myocardial I/R and isolated neonatal rat cardiomyocytes. H9c2 cells and cardiomyocytes were treated with the ferroptosis inducers erastin, RSL3, and Fe-SP. GAA could protect H9c2 cells against ferroptotic cell death caused by these ferroptosis inducers by decreasing the production of malondialdehyde and reactive oxygen species, chelating iron content, and downregulating mRNA levels of Ptgs2. GAA could prevent oxygen-glucose deprivation/reperfusion-induced cell death and lipid peroxidation in the cardiomyocytes. Moreover, GAA significantly attenuated myocardial infarct size, reduced lipid peroxidation, decreased the mRNA levels of the ferroptosis markers Ptgs2 and Acsl4, decreased the protein levels of ACSL4 and NRF2, and increased the protein levels of GPX4 in I/R-induced ex vivo rat hearts. Thus, GAA may play a cytoprotectant role in ferroptosis-induced cardiomyocyte death and myocardial I/R-induced ferroptotic cell death.


2018 ◽  
Author(s):  
Hongying Fan ◽  
Ruqin Lin ◽  
Zhenhui Chen ◽  
Xingyu Leng ◽  
Xianbo Wu ◽  
...  

AbstractCronobacter sakazakii (CS), an important pathogen, is associated with the development of necrotizing enterocolitis (NEC), infant sepsis, and meningitis. Several randomized prospective clinical trials demonstrated that oral probiotics could decrease the incidence of NEC. Previously, we isolated and characterized a novel probiotic, B. fragilis strain ZY-312. However, it remains unclear how ZY-312 protects the host from the effects of CS infection. To understand the underlying mechanisms triggering the probiotic effects, we tested the hypothesis that there was a cross-talk between probiotics/probiotics-modulated microbiota and the local immune system, governed by the permeability of the intestinal mucosa using in vitro and in vivo models for the intestinal permeability. The probiotic effects of ZY-312 on intestinal epithelial cells were first examined, which revealed that ZY-312 inhibited CS invasion, CS-induced dual cell death (pyroptosis and apoptosis), and epithelial barrier dysfunction in vitro and in vivo. ZY-312 also decreased the expression of an inflammasome (NOD-like receptor family member pyrin domain-containing protein 3 (NLRP3), caspase-3, and serine protease caspase-1 in a neonatal rat model. Furthermore, ZY-312 significantly modulated the compositions of the intestinal bacterial communities, and decreased the relative abundances of Proteobacteria, Gamma proteobacteria, but increased the relative abundance of Bacteroides and Bacillus in neonatal rats. In conclusion, our findings have shown for the first time that the probiotic, B. fragilis ZY-312, suppresses CS-induced NEC by modulating the pro-inflammatory response and dual cell death (apoptosis and pyroptosis).Author summaryCronobacter sakazakii, a major necrotizing enterocolitis pathogen, is used as a model microorganism for the study of opportunistic bacteria in the pathogenesis of necrotizing enterocolitis. Here, we have now unequivocally demonstrated that both apoptotic and pyroptotic stimuli contribute to the pathogenesis of Cronobacter sakazakii -induced necrotizing enterocolitis. Previously, we isolated and characterized a novel probiotic, B. fragilis strain ZY-312. We found that the ZY-312 defense against Cronobacter sakazakii-induced necrotizing enterocolitis by inhibiting Cronobacter sakazakii invasion, epithelial barrier dysfunction, the expression of inflammatory cytokines and dual cell death (pyroptosis and apoptosis). This study demonstrates the utility of ZY-312 as a promising probiotic agent for the prevention and treatment of various intestinal diseases, including NEC.


2015 ◽  
Vol 117 (suppl_1) ◽  
Author(s):  
Navid Koleini ◽  
Jon Jon Santiago ◽  
Barbara E Nickel ◽  
Robert Fandrich ◽  
Davinder S Jassal ◽  
...  

Introduction: Protection of the heart from chemotherapeutic (Doxorubicin, DOX) drug-induced toxicity is a desirable goal, to limit side effects of cancer treatments. DOX toxicity has been linked to the activation (phosphorylation) of the AMP-activated kinase, AMPK. The 18 kDa low molecular weight isoform of fibroblast growth factor 2 (Lo-FGF-2) is a known cardioprotective and cytoprotective agent. In this study we have tested the ability of Lo-FGF-2 to protect from DOX-induced damage in rat cardiomyocytes in vitro, and in transgenic mouse models in vivo, in relation to AMPK activation. Methods: Rat neonatal cardiomyocytes in culture were exposed to DOX (0.5 μM) in the presence or absence of pre-treatment Lo-FGF-2 (10 ng/ml). Compound C was used to block phosphorylation (activity) of AMPK. Levels of cell viability/death (using Calcein-AM/Propidium iodide assay), phospho -and total AMPK, and apoptotic markers such as active caspase 3 were analyzed. In addition, transgenic mice expressing only Lo-FGF2, and wild type mice, expressing both high molecular weight (Hi-FGF2) as well as Lo-FGF2 were subjected to DOX injection (20 mg/kg, intraperitoneal); echocardiography was used to examine cardiac function at baseline and at 10 days post-DOX. Results: DOX-induced cell death of cardiomyocytes in culture was maximal at 24 hours post-DOX coinciding with significantly increased in activated (phosphorylated) AMPK. Compound C attenuated DOX-induced cardiomyocyte loss. Pre-incubation with Lo-FGF-2 decreased DOX induced cell death, and also attenuated the phosphorylation of AMPK post-DOX. Relative levels of phospho-AMPK were lower in the hearts of Lo-FGF2-expressing male mice compared to wild type. DOX-induced loss of contractile function (left ventricular ejection fraction and endocardial velocity) was negligible in Lo-FGF2-expressing mice but significant in wild type mice. Conclusion: Lo-FGF-2 protects the heart from DOX-induced damage in vitro and in vivo, by a mechanism likely involving an attenuation of AMPK activity.


1995 ◽  
Vol 76 (6) ◽  
pp. 1071-1078 ◽  
Author(s):  
Douwe E. Atsma ◽  
E.M. Lars Bastiaanse ◽  
Anastazia Jerzewski ◽  
Lizet J.M. Van der Valk ◽  
Arnoud Van der Laarse

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