scholarly journals A20 (TNFAIP3) alleviates viral myocarditis through ADAR1/miR-1a-3p-dependent regulation

2022 ◽  
Vol 22 (1) ◽  
Author(s):  
Bin Li ◽  
Xing Xie
Keyword(s):  
Creatine Kinase ◽  
Rna Binding ◽  
Viral Myocarditis ◽  
Neonatal Rat ◽  
Coxsackie Virus ◽  
Luciferase Reporter ◽  
Cell Culture Supernatant ◽  
Tunel Staining ◽  
Rat Cardiomyocytes ◽  
Cellular Models

Abstract Objective To investigate the effect of A20 and how A20 is regulated in viral myocarditis (VMC). Methods BABL/C mice, primary neonatal rat cardiomyocytes and H9c2 cells were infected with Coxsackie virus B3 (CVB3) to establish animal and cellular models of VMC. H&E staining revealed the pathologic condition of myocardium. ELISA measured the serum levels of creatine kinase, creatine kinase isoenzyme and cardiac troponin I. The effects of A20, miR-1a-3p and ADAR1 were investigated using gain and loss of function approaches. ELISA measured the levels of IL-6, IL-18 and TNF-α in serum or cell culture supernatant. TUNEL staining and flow cytometry assessed the apoptosis of myocardium and cardiomyocytes, respectively. RNA-binding protein immunoprecipitation and dual-luciferase reporter assays verified the binding between A20 and miR-1a-3p. Co-immunoprecipitation assay verified the binding between ADAR1 and Dicer. Results A20 was underexpressed and miR-1a-3p was overexpressed in the myocardium of VMC mice as well as in CVB3-infected cardiomyocytes. Overexpression of A20 suppressed cardiomyocyte inflammation and apoptosis in vivo and in vitro. miR-1a-3p promoted CVB3-induced inflammation and apoptosis in cardiomyocytes by binding to A20. The expression of miR-1a-3p was regulated by ADAR1. ADAR1 promoted the slicing of miR-1a-3p precursor by binding to Dicer. Conclusion A20, regulated by ADAR1/miR-1a-3p, suppresses inflammation and cardiomyocyte apoptosis in VMC.

scholarly journals Inhibition of calpain reduces cell apoptosis by suppressing mitochondrial fission in acute viral myocarditis

2021 ◽  
Author(s):  
Hui Shi ◽  
Ying Yu ◽  
Xiaoxiao Liu ◽  
Yong Yu ◽  
Minghui Li ◽  
...  
Keyword(s):  
Western Blotting ◽  
Mitochondrial Function ◽  
Mitochondrial Fission ◽  
Viral Myocarditis ◽  
Cardiomyocyte Apoptosis ◽  
Neonatal Rat ◽  
Tunel Staining ◽  
Mitochondrial Morphology ◽  
Rat Cardiomyocytes ◽  
Cvb3 Infection

AbstractCardiomyocyte apoptosis is critical for the development of viral myocarditis (VMC), which is one of the leading causes of cardiac sudden death in young adults. Our previous studies have demonstrated that elevated calpain activity is involved in the pathogenesis of VMC. This study aimed to further explore the underlying mechanisms. Neonatal rat cardiomyocytes (NRCMs) and transgenic mice overexpressing calpastatin were infected with coxsackievirus B3 (CVB3) to establish a VMC model. Apoptosis was detected with flow cytometry, TUNEL staining, and western blotting. Cardiac function was measured using echocardiography. Mitochondrial function was measured using ATP assays, JC-1, and MitoSOX. Mitochondrial morphology was observed using MitoTracker staining and transmission electron microscopy. Colocalization of dynamin-related protein 1 (Drp-1) in mitochondria was examined using immunofluorescence. Phosphorylation levels of Drp-1 at Ser637 site were determined using western blotting analysis. We found that CVB3 infection impaired mitochondrial function as evidenced by increased mitochondrial ROS production, decreased ATP production and mitochondrial membrane potential, induced myocardial apoptosis and damage, and decreased myocardial function. These effects of CVB3 infection were attenuated by inhibition of calpain both by PD150606 treatment and calpastatin overexpression. Furthermore, CVB3-induced mitochondrial dysfunction was associated with the accumulation of Drp-1 in the outer membrane of mitochondria and subsequent increase in mitochondrial fission. Mechanistically, calpain cleaved and activated calcineurin A, which dephosphorylated Drp-1 at Ser637 site and promoted its accumulation in the mitochondria, leading to mitochondrial fission and dysfunction. In summary, calpain inhibition attenuated CVB3-induced myocarditis by reducing mitochondrial fission, thereby inhibiting cardiomyocyte apoptosis.

Abstract P279: YAP, a Transcriptional Cofactor of the Hippo Pathway, Regulates Cardiomyocyte Growth, Survival, and Proliferation

2011 ◽  
Vol 109 (suppl_1) ◽  
Author(s):  
Yanfei Yang ◽  
Noritsugu Nakano ◽  
Junichi Sadoshima
Keyword(s):  
Cardiac Hypertrophy ◽  
Hippo Pathway ◽  
Neonatal Rat ◽  
Border Zone ◽  
Luciferase Reporter ◽  
Tunel Staining ◽  
H2o2 Treatment ◽  
Rat Hearts ◽  
The Hippo Pathway

Mst1 and Lats2, components of the mammalian Hippo pathway, stimulate apoptosis and inhibit hypertrophy of cardiomyocytes (CMs), thereby mediating reperfusion injury and heart failure. YAP, a transcription factor co-factor, is negatively regulated by the Hippo pathway, and controls cell survival, proliferation and tissue regeneration. The role of YAP in regulating growth and death of CMs is poorly understood. YAP overexpression in CMs induced cardiac hypertrophy, as indicated by increases in cell size (+1.2 fold, p<0.01), protein content (+1.1 fold, p<0.01) and ANF (luciferase reporter activity +1.7 fold, mRNA +2.2 fold, and staining +2.7 fold, p<0.01). Lats2 phosphorylates YAP at Serine 127, which induces cytoplasmic translocation of YAP, whereas YAP(S127A) is localized constitutively in the nucleus. Expression of YAP(S127A) enhanced hypertrophy in cultured CMs compared to that of wild type YAP (+1.87 fold ANF staining, p<0.05), suggesting that the Mst1/Hippo pathway negatively regulates cardiac hypertrophy through YAP. YAP inhibited cell death induced by H2O2 treatment, as evaluated with TUNEL staining (-65%, p<0.05) and CellTiter Blue assays (+34.9%, p<0.01), indicating that YAP plays an essential role in mediating CM survival. Interestingly, YAP also significantly increased Ki67 positive cells in cultured CMs compared to LacZ (+2.65 fold, p<0.05). We used a mouse model of chronic myocardial infarction (MI) to evaluate the function of YAP in the heart in vivo. Although YAP is diffusely localized both in the nucleus and cytosol in CMs in control hearts, CMs in the border zone of MI exhibited nuclear localization of YAP whereas YAP was excluded from the nucleus in CMs in the remodeling area four days after MI (+6.52 fold and +1.28 fold). Some of the YAP positive CMs in the border zone exhibited positive co-staining with Ki67, suggesting that YAP potentially induces CM proliferation. A significant increase in nuclear YAP and Ki67 positive CMs (+2.95 fold, p<0.01 and +2.18 fold, p<0.05) was also observed in neonatal rat hearts whose apex was surgically resected three days before euthanasia. These results suggest that YAP plays an important role in mediating not only hypertrophy and survival, but also proliferation of CMs in response to myocardial injury.

scholarly journals Overexpression of TIMP3 Protects Against Cardiac Ischemia/Reperfusion Injury by Inhibiting Myocardial Apoptosis Through ROS/Mapks Pathway

2017 ◽  
Vol 44 (3) ◽  
pp. 1011-1023 ◽  
Author(s):  
Hui Liu ◽  
Xibo Jing ◽  
Aiqiao Dong ◽  
Baobao Bai ◽  
Haiyan Wang
Keyword(s):  
Myocardial Infarct ◽  
Ischemia Reperfusion ◽  
Neonatal Rat ◽  
Tunel Staining ◽  
Ros Production ◽  
Rat Cardiomyocytes ◽  
Doxorubicin Treatment ◽  
Myocardial Apoptosis

Background/Aims: Myocardial ischemia/reperfusion (I/R) injury remains a great challenge in clinical therapy. Tissue inhibitor of metalloproteinases 3 (TIMP3) plays a crucial role in heart physiological and pathophysiological processes. However, the effects of TIMP3 on I/R injury remain unknown. Methods: C57BL/6 mice were infected with TIMP3 adenovirus by local delivery in myocardium followed by I/R operation or doxorubicin treatment. Neonatal rat cardiomyocytes were pretreated with TIMP3 adenovirus prior to anoxia/reoxygenation (A/R) treatment in vitro. Histology, echocardiography, in vivo phenotypical analysis, flow cytometry and western blotting were used to investigate the altered cardiac function and underlying mechanisms. Results: The results showed that upregulation of TIMP3 in myocardium markedly inhibited myocardial infarct areas and the cardiac dysfunction induced by I/R or by doxorubicin treatment. TUNEL staining revealed that TIMP3 overexpression attenuated I/R-induced myocardial apoptosis, accompanied by decreased Bax/Bcl-2 ratio, Cleaved Caspase-3 and Cleaved Caspase-9 expression. In vitro, A/R-induced cardiomyocyte apoptosis was abrogated by pharmacological inhibition of reactive oxygen species (ROS) production or MAPKs signaling. Attenuation of ROS production reversed A/R-induced MAPKs activation, whereas MAPKs inhibitors showed on effect on ROS production. Furthermore, in vivo or in vitro overexpression of TIMP3 significantly inhibited I/R- or A/R-induced ROS production and MAPKs activation. Conclusion: Our findings demonstrate that TIMP3 upregulation protects against cardiac I/R injury through inhibiting myocardial apoptosis. The mechanism may be related to inhibition of ROS-initiated MAPKs pathway. This study suggests that TIMP3 may be a potential therapeutic target for the treatment of I/R injury.

scholarly journals RBM20 Regulates CaV1.2 Surface Expression by Promoting Exon 9* Inclusion of CACNA1C in Neonatal Rat Cardiomyocytes

2019 ◽  
Vol 20 (22) ◽  
pp. 5591 ◽  
Author(s):  
Morinaga ◽  
Ito ◽  
Niimi ◽  
Maturana
Keyword(s):  
Alternative Splicing ◽  
Heart Development ◽  
Rna Binding ◽  
Surface Expression ◽  
Neonatal Rat ◽  
Sequencing Analysis ◽  
Rat Cardiomyocytes ◽  
Neonatal Rat Cardiomyocytes ◽  
Exon 9 ◽  
Sirna Knockdown

The CACNA1C gene encodes for the CaV1.2 protein, which is the pore subunit of cardiac l-type voltage-gated calcium (Ca2+) channels (l-channels). Through alternative splicing, CACNA1C encodes for various CaV1.2 isoforms with different electrophysiological properties. Splice variants of CaV1.2 are differentially expressed during heart development or pathologies. The molecular mechanisms of CACNA1C alternative splicing still remain incompletely understood. RNA sequencing analysis has suggested that CACNA1C is a potential target of the splicing factor RNA-binding protein motif 20 (RBM20). Here, we aimed at elucidating the role of RBM20 in the regulation of CACNA1C alternative splicing. We found that in neonatal rat cardiomyocytes (NRCMs), RBM20 overexpression promoted the inclusion of CACNA1C’s exon 9*, whereas the skipping of exon 9* occurred upon RBM20 siRNA knockdown. The splicing of other known alternative exons was not altered by RBM20. RNA immunoprecipitation suggested that RBM20 binds to introns flanking exon 9*. Functionally, in NRCMs, RBM20 overexpression decreased l-type Ca2+ currents, whereas RBM20 siRNA knockdown increased l-type Ca2+ currents. Finally, we found that RBM20 overexpression reduced CaV1.2 membrane surface expression in NRCMs. Taken together, our results suggest that RBM20 specifically regulates the inclusion of exon 9* in CACNA1C mRNA, resulting in reduced cell-surface membrane expression of l-channels in cardiomyocytes.

Chronic hypoxia–induced Cirbp hypermethylation attenuates hypothermic cardioprotection via down-regulation of ubiquinone biosynthesis

2019 ◽  
Vol 11 (489) ◽  
pp. eaat8406 ◽  
Author(s):  
Yiwei Liu ◽  
Junyue Xing ◽  
Yongnan Li ◽  
Qipeng Luo ◽  
Zhanhao Su ◽  
...  
Keyword(s):  
Cardiac Surgery ◽  
Therapeutic Hypothermia ◽  
Myocardial Injury ◽  
Chronic Hypoxia ◽  
Rna Binding ◽  
Epigenetic Modification ◽  
Neonatal Rat ◽  
Proteomics Analysis ◽  
Rat Cardiomyocytes ◽  
Underlying Mechanisms

Therapeutic hypothermia is commonly used during cardiopulmonary bypass (CPB) to protect the heart against myocardial injury in cardiac surgery. Patients who suffer from chronic hypoxia (CH), such as those with certain heart or lung conditions, are at high risk of severe myocardial injury after cardiac surgery, but the underlying mechanisms are unknown. This study tested whether CH attenuates hypothermic cardioprotection during CPB. Using a rat model of CPB, we found that hypothermic cardioprotection was impaired in CH rats but was preserved in normoxic rats. Cardiac proteomes showed that cold-inducible RNA binding protein (CIRBP) was significantly (P = 0.03) decreased in CH rats during CPB. Methylation analysis of neonatal rat cardiomyocytes under CH and myocardium specimens from patients with CH showed that CH induced hypermethylation of the Cirbp promoter region, resulting in its depression and failure to respond to cold stress. Cirbp-knockout rats showed attenuated hypothermic cardioprotection, whereas Cirbp-transgenic rats showed an enhanced response. Proteomics analysis revealed that the cardiac ubiquinone biosynthesis pathway was down-regulated during CPB in Cirbp-knockout rats, resulting in a significantly (P = 0.01) decreased concentration of ubiquinone (CoQ10). Consequently, cardiac oxidative stress was aggravated and adenosine 5′-triphosphate production was impaired, leading to increased myocardial injury during CPB. CoQ10-supplemented cardioplegic solution improved cardioprotection in rats exposed to CH, but its effect was limited in normoxic rats. Our study suggests that an individualized cardioprotection strategy should be used to fully compensate for the consequences of epigenetic modification of Cirbp in patients with CH who require therapeutic hypothermia.

M-CAT element mediates mechanical stretch-activated transcription of B-type natriuretic peptide via ERK activation

2011 ◽  
Vol 89 (8) ◽  
pp. 539-550 ◽  
Author(s):  
Elina Koivisto ◽  
Laura Karkkola ◽  
Theresa Majalahti ◽  
Jani Aro ◽  
Heikki Tokola ◽  
...  
Keyword(s):  
Natriuretic Peptide ◽  
Mechanical Stretch ◽  
Neonatal Rat ◽  
Luciferase Reporter ◽  
Transcriptional Enhancer ◽  
Luciferase Reporter Construct ◽  
Rat Cardiomyocytes ◽  
Erk Activation ◽  
Enhancer Factor

The muscle-CAT (M-CAT) promoter element is found on promoters of most muscle-specific cardiac genes, but its role in cardiac pathology is poorly understood. Here we studied whether the M-CAT element is involved in hypertrophic process activated by mechanical stretch, and identified the intracellular pathways mediating the response. When an in vitro stretch model of cultured neonatal rat cardiomyocytes and luciferase reporter construct driven by rat B-type natriuretic peptide (BNP) promoter were used, mutation of M-CAT element inhibited not only the basal reporter activity (88%), but also the stretch-activated BNP transcription (58%, p < 0.001). Stretch-induced BNP promoter activation was associated with an increase in transcriptional enhancer factor-1 (TEF-1) binding activity after 24 h mechanical stretch (p < 0.05). Inhibition of mitogen-activated protein kinases ERK, JNK, or p38 attenuated stretch-induced BNP activation. Interestingly, as opposed to p38 and JNK, inhibition of ERK had no additional effect on transcriptional activity of BNP promoter harboring the M-CAT mutation, suggesting a pivotal role for ERK in regulating stretch-induced BNP transcription via M-CAT binding site. Finally, immunoprecipitation studies showed that mechanical stretch induced myocyte enhancer factor-2 (MEF-2) binding to TEF-1. These data suggest a central role for M-CAT element in regulation of mechanical stretch-induced hypertrophic response via ERK activation.

scholarly journals BMP type I receptor ALK2 is required for angiotensin II-induced cardiac hypertrophy

2016 ◽  
Vol 310 (8) ◽  
pp. H984-H994 ◽  
Author(s):  
Mohd Shahid ◽  
Ester Spagnolli ◽  
Laura Ernande ◽  
Robrecht Thoonen ◽  
Starsha A. Kolodziej ◽  
...  
Keyword(s):  
Gene Expression ◽  
Angiotensin Ii ◽  
Cardiac Hypertrophy ◽  
Left Ventricular ◽  
Bmp Signaling ◽  
Neonatal Rat ◽  
Luciferase Reporter ◽  
Type I ◽  
Nuclear Factor ◽  
Rat Cardiomyocytes

Bone morphogenetic protein (BMP) signaling contributes to the development of cardiac hypertrophy. However, the identity of the BMP type I receptor involved in cardiac hypertrophy and the underlying molecular mechanisms are poorly understood. By using quantitative PCR and immunoblotting, we demonstrated that BMP signaling increased during phenylephrine-induced hypertrophy in cultured neonatal rat cardiomyocytes (NRCs), as evidenced by increased phosphorylation of Smads 1 and 5 and induction of Id1 gene expression. Inhibition of BMP signaling with LDN193189 or noggin, and silencing of Smad 1 or 4 using small interfering RNA diminished the ability of phenylephrine to induce hypertrophy in NRCs. Conversely, activation of BMP signaling with BMP2 or BMP4 induced hypertrophy in NRCs. Luciferase reporter assay further showed that BMP2 or BMP4 treatment of NRCs repressed atrogin-1 gene expression concomitant with an increase in calcineurin protein levels and enhanced activity of nuclear factor of activated T cells, providing a mechanism by which BMP signaling contributes to cardiac hypertrophy. In a model of cardiac hypertrophy, C57BL/6 mice treated with angiotensin II (A2) had increased BMP signaling in the left ventricle. Treatment with LDN193189 attenuated A2-induced cardiac hypertrophy and collagen deposition in left ventricles. Cardiomyocyte-specific deletion of BMP type I receptor ALK2 (activin-like kinase 2), but not ALK1 or ALK3, inhibited BMP signaling and mitigated A2-induced cardiac hypertrophy and left ventricular fibrosis in mice. The results suggest that BMP signaling upregulates the calcineurin/nuclear factor of activated T cell pathway via BMP type I receptor ALK2, contributing to cardiac hypertrophy and fibrosis.

Abstract 359: Negative Regulation Of The Fgf-16 Gene Promoter By Doxorubicin Is Associated With A Decrease In Nkx2.5 Binding

2014 ◽  
Vol 115 (suppl_1) ◽  
Author(s):  
Jie Wang ◽  
Yan Jin ◽  
Peter A Cattini
Keyword(s):  
Heart Development ◽  
Promoter Region ◽  
Isolated Heart ◽  
Neonatal Rat ◽  
Proximal Promoter ◽  
Luciferase Reporter ◽  
Cancer Drug ◽  
Rat Cardiomyocytes ◽  
Proximal Promoter Region ◽  
Rna Levels

Doxorubicin (DOX) is a widely used and effective anti-cancer drug, but it is also cardiotoxic, which can lead to heart failure, and so strategies are needed to protect the heart. Fibroblast growth factor 16 (FGF-16) is preferentially expressed and released from cardiomyocytes after birth. Evidence suggests that FGF-16 decreases the risk of heart damage and limits the negative effects of heart remodeling (hypertrophy and fibrosis) after injury in vivo. Exogenous addition of FGF-16 also increased resistance to the loss of contractility in an isolated heart model of acute DOX-induced injury. Thus, how endogenous FGF-16 production and by extension function is affected by DOX treatment is of interest. The FGF-16 gene is highly conserved between human and murine species. Alignment of sequences indicates a conserved Nkx2.5 binding site in the proximal promoter region that is associated with a previously characterized TATA box. Nkx2.5 is an important factor in vertebrate heart development and congenital disease. Furthermore, Nkx2.5 RNA levels are decreased with DOX treatment. Thus, the possibility that DOX negatively affects FGF-16, perhaps through an effect on Nkx2.5 levels or binding, was investigated. Neonatal rat cardiomyocytes were treated with DOX, and FGF-16 RNA levels decreased 75% within 6 hours as assessed by qPCR. Inhibition of transcription with actinomycinD had no effect on the DOX-induced decrease in FGF-16 RNA levels. Further support for an effect of DOX on FGF-16 transcription was obtained by transfection of cardiomyocytes with a hybrid 747 bp mouse FGF-16 promoter/luciferase reporter gene that was treated with DOX; a significant decrease in luciferase activity was observed. Electrophoretic mobility shift and chromatin immunoprecipitation assays suggest reduced Nkx2.5 protein-DNA interaction with this site after DOX treatment in vitro and in situ, respectively. These data indicate that DOX decreases FGF-16 RNA expression and this correlates with a decrease in Nkx2.5 levels and association with the proximal promoter region. A direct effect of Nkx2.5 on FGF-16 promoter activity awaits further testing. Thus, a decrease or loss of FGF-16 synthesis might contribute to the DOX-induced damage and/or response to injury.

Abstract 347: Targeted FAK Activation in Cardiomyocytes Protects the Heart from Doxorubicin-Induced Cardiomyopathy

2012 ◽  
Vol 111 (suppl_1) ◽  
Author(s):  
Zhaokang Cheng ◽  
Laura A DiMichele ◽  
Zeenat S Hakim ◽  
Mauricio Rojas ◽  
Christopher P Mack ◽  
...  
Keyword(s):  
Ischemia Reperfusion ◽  
Posterior Wall ◽  
Neonatal Rat ◽  
Tunel Staining ◽  
Littermate Control ◽  
Rat Cardiomyocytes ◽  
Enhanced Expression ◽  
Myocyte Apoptosis ◽  
Novel Strategy ◽  
Induced Apoptosis

OBJECTIVE: We recently reported that cardiac-restricted activation of focal adhesion kinase (FAK) attenuated myocardial injury following ischemia/reperfusion using transgenic mice that express a FAK variant (termed SuperFAK) in cardiomyocytes. Here we interrogated whether targeted elevation of myocardial FAK activity could protect against cardiomyopathy induced by the highly effective chemotherapy drug Doxorubicin (DOX). METHODS AND RESULTS: Eight- to twelve-week-old male mice were given a single injection of DOX (20mg/kg, i.p.). At day 14, SuperFAK mice exhibited better survival (62.5%, n=8) than littermate control mice (37.5%, n=8). Serial echocardiography revealed that DOX administration markedly decreased cardiac function and ventricular wall thickness in control mice, whereas both parameters were better preserved in SuperFAK mice at day 5 (fractional shortening: 52.7±1.5% in SuperFAK vs . 38.9±3.7% in control, p <0.01; posterior wall end-systolic thickness: 1.83±0.12mm in SuperFAK vs . 1.43±0.12mm in control, p <0.05). Importantly, SuperFAK hearts exhibited a dramatic increase in FAK activity (as assessed by phospho-FAK Y397 immunoblotting) and a reduction in myocyte apoptosis (as assessed by TUNEL staining) in comparison with control hearts. DOX also induced apoptosis in cultured neonatal rat cardiomyocytes and adenoviral-mediated expression of SuperFAK ameliorated DOX-induced toxicity as assessed by MTT and TUNEL assays. Over-expression of SuperFAK also enhanced expression of the pro-survival NF-κB transcriptional targets Bcl-2, Bcl-xl, and X-linked inhibitor of apoptosis, whereas pharmacologically blockade of the NF-κB pathway completely abolished the up-regulation of these anti-apoptotic molecules by SuperFAK. CONCLUSIONS: Ventricular dysfunction and myocyte apoptosis induced by DOX was attenuated by enhancing cardiac FAK activity, which may represent a novel strategy to reduce anthracycline mediated cardiotoxicity in cancer patients undergoing chemotherapy.

scholarly journals Exogenous H2S reduces the acetylation levels of mitochondrial respiratory enzymes via regulating the NAD+-SIRT3 pathway in cardiac tissues of db/db mice

2019 ◽  
Vol 317 (2) ◽  
pp. E284-E297 ◽  
Author(s):  
Yu Sun ◽  
Zongyan Teng ◽  
Xiaojiao Sun ◽  
Linxue Zhang ◽  
Jian Chen ◽  
...  
Keyword(s):  
Respiratory Chain ◽  
Mitochondrial Respiratory Chain ◽  
Neonatal Rat ◽  
Mass Spectrometry Analysis ◽  
Rat Cardiomyocytes ◽  
Sodium Hydrosulfide ◽  
Acetylation Level ◽  
Atp Production ◽  
Cellular Models ◽  
Mitochondrial Respiratory

Hydrogen sulfide (H2S), a gaseous molecule, is involved in modulating multiple physiological functions, such as antioxidant, antihypertension, and the production of polysulfide cysteine. H2S may inhibit reactive oxygen species generation and ATP production through modulating respiratory chain enzyme activities; however, the mechanism of this effect remains unclear. In this study, db/db mice, neonatal rat cardiomyocytes, and H9c2 cells treated with high glucose, oleate, and palmitate were used as animal and cellular models of type 2 diabetes. The mitochondrial respiratory rate, respiratory chain complex activities, and ATP production were decreased in db/db mice compared with those in db/db mice treated with exogenous H2S. Liquid chromatography with tandem mass spectrometry analysis showed that the acetylation level of proteins involved in the mitochondrial respiratory chain were increased in the db/db mice hearts compared with those with sodium hydrosulfide (NaHS) treatment. Exogenous H2S restored the ratio of NAD+/NADH, enhanced the expression and activity of sirtuin 3 (SIRT3) and decreased mitochondrial acetylation level in cardiomyocytes under hyperglycemia and hyperlipidemia. As a result of SIRT3 activation, acetylation of the respiratory complexe enzymes NADH dehydrogenase 1 (ND1), ubiquinol cytochrome c reductase core protein 1, and ATP synthase mitochondrial F1 complex assembly factor 1 was reduced, which enhanced the activities of the mitochondrial respiratory chain activity and ATP production. We conclude that exogenous H2S plays a critical role in improving cardiac mitochondrial function in diabetes by upregulating SIRT3.

Sign in / Sign up

Export Citation Format

Share Document