scholarly journals MitoQ regulates redox-related noncoding RNAs to preserve mitochondrial network integrity in pressure-overload heart failure

2020 ◽  
Vol 318 (3) ◽  
pp. H682-H695 ◽  
Author(s):  
Seulhee Kim ◽  
Jiajia Song ◽  
Patrick Ernst ◽  
Mary N. Latimer ◽  
Chae-Myeong Ha ◽  
...  

Evidence suggests that mitochondrial network integrity is impaired in cardiomyocytes from failing hearts. While oxidative stress has been implicated in heart failure (HF)-associated mitochondrial remodeling, the effect of mitochondrial-targeted antioxidants, such as mitoquinone (MitoQ), on the mitochondrial network in a model of HF (e.g., pressure overload) has not been demonstrated. Furthermore, the mechanism of this regulation is not completely understood with an emerging role for posttranscriptional regulation via long noncoding RNAs (lncRNAs). We hypothesized that MitoQ preserves mitochondrial fusion proteins (i.e., mitofusin), likely through redox-sensitive lncRNAs, leading to improved mitochondrial network integrity in failing hearts. To test this hypothesis, 8-wk-old C57BL/6J mice were subjected to ascending aortic constriction (AAC), which caused substantial left ventricular (LV) chamber remodeling and remarkable contractile dysfunction in 1 wk. Transmission electron microscopy and immunostaining revealed defective intermitochondrial and mitochondrial-sarcoplasmic reticulum ultrastructure in AAC mice compared with sham-operated animals, which was accompanied by elevated oxidative stress and suppressed mitofusin (i.e., Mfn1 and Mfn2) expression. MitoQ (1.36 mg·day−1·mouse−1, 7 consecutive days) significantly ameliorated LV dysfunction, attenuated Mfn2 downregulation, improved interorganellar contact, and increased metabolism-related gene expression. Moreover, our data revealed that MitoQ alleviated the dysregulation of an Mfn2-associated lncRNA (i.e., Plscr4). In summary, the present study supports a unique mechanism by which MitoQ improves myocardial intermitochondrial and mitochondrial-sarcoplasmic reticulum (SR) ultrastructural remodeling in HF by maintaining Mfn2 expression via regulation by an lncRNA. These findings underscore the important role of lncRNAs in the pathogenesis of HF and the potential of targeting them for effective HF treatment. NEW & NOTEWORTHY We have shown that MitoQ improves cardiac mitochondrial network integrity and mitochondrial-SR alignment in a pressure-overload mouse heart-failure model. This may be occurring partly through preventing the dysregulation of a redox-sensitive lncRNA-microRNA pair (i.e., Plscr4-miR-214) that results in an increase in mitofusin-2 expression.

2014 ◽  
Vol 306 (10) ◽  
pp. H1453-H1463 ◽  
Author(s):  
Fuzhong Qin ◽  
Deborah A. Siwik ◽  
David R. Pimentel ◽  
Robert J. Morgan ◽  
Andreia Biolo ◽  
...  

Oxidative stress in the myocardium plays an important role in the pathophysiology of hemodynamic overload. The mechanism by which reactive oxygen species (ROS) in the cardiac myocyte mediate myocardial failure in hemodynamic overload is not known. Accordingly, our goals were to test whether myocyte-specific overexpression of peroxisomal catalase (pCAT) that localizes in the sarcoplasm protects mice from hemodynamic overload-induced failure and prevents oxidation and inhibition of sarco(endo)plasmic reticulum Ca2+-ATPase (SERCA), an important sarcoplasmic protein. Chronic hemodynamic overload was caused by ascending aortic constriction (AAC) for 12 wk in mice with myocyte-specific transgenic expression of pCAT. AAC caused left ventricular hypertrophy and failure associated with a generalized increase in myocardial oxidative stress and specific oxidative modifications of SERCA at cysteine 674 and tyrosine 294/5. pCAT overexpression ameliorated myocardial hypertrophy and apoptosis, decreased pathological remodeling, and prevented the progression to heart failure. Likewise, pCAT prevented oxidative modifications of SERCA and increased SERCA activity without changing SERCA expression. Thus cardiac myocyte-restricted expression of pCAT effectively ameliorated the structural and functional consequences of chronic hemodynamic overload and increased SERCA activity via a post-translational mechanism, most likely by decreasing inhibitory oxidative modifications. In pressure overload-induced heart failure cardiac myocyte cytosolic ROS play a pivotal role in mediating key pathophysiologic events including hypertrophy, apoptosis, and decreased SERCA activity.


2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Shengqi Huo ◽  
Wei Shi ◽  
Haiyan Ma ◽  
Dan Yan ◽  
Pengcheng Luo ◽  
...  

Background. Inflammation and oxidative stress are involved in the initiation and progress of heart failure (HF). However, the role of the IL6/STAT3 pathway in the pressure overload-induced HF remains controversial. Methods and Results. Transverse aortic constriction (TAC) was used to induce pressure overload-HF in C57BL/6J mice. 18 mice were randomized into three groups (Sham, TAC, and TAC+raloxifene, n = 6 , respectively). Echocardiographic and histological results showed that cardiac hypertrophy, fibrosis, and left ventricular dysfunction were manifested in mice after TAC treatment of eight weeks, with aggravation of macrophage infiltration and interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-α) expression in the myocardium. TAC (four and eight weeks) elevated the phosphorylation of signal transducer and activator of transcription 3 (p-STAT3) and prohibitin2 (PHB2) protein expression. Importantly, IL-6/gp130/STAT3 inhibition by raloxifene alleviated TAC-induced myocardial inflammation, cardiac remodeling, and dysfunction. In vitro, we demonstrated cellular hypertrophy with STAT3 activation and oxidative stress exacerbation could be elicited by IL-6 (25 ng/mL, 48 h) in H9c2 myoblasts. Sustained IL-6 stimulation increased intracellular reactive oxygen species, repressed mitochondrial membrane potential (MMP), decreased intracellular content of ATP, and led to decreased SOD activity, an increase in iNOS protein expression, and increased protein expression of Pink1, Parkin, and Bnip3 involving in mitophagy, all of which were reversed by raloxifene. Conclusion. Inflammation and IL-6/STAT3 signaling were activated in TAC-induced HF in mice, while sustained IL-6 incubation elicited oxidative stress and mitophagy-related protein increase in H9c2 myoblasts, all of which were inhibited by raloxifene. These indicated IL-6/STAT3 signaling might be involved in the pathogenesis of myocardial hypertrophy and HF.


Circulation ◽  
2007 ◽  
Vol 116 (suppl_16) ◽  
Author(s):  
Shungo Hikoso ◽  
Kinya Otsu ◽  
Osamu Yamaguchi ◽  
Toshihiro Takeda ◽  
Masayuki Taniike ◽  
...  

Objectives: We have previously reported that NF-κB contributes to GPCR agonist-induced hypertrophy in cultured cardiomyocytes. However, the in vivo role of this pathway in the pathogenesis of cardiac remodeling remains to be elucidated. Although IκB kinase β (IKKβ)/NF-κB pathway is a major negative regulator of cell death, it can sensitize cells to death-inducing stimuli in some instances, thus it can be either anti- or pro-apoptotic. In this study, we aimed to clarify the role of IKKβ/NF-κB signaling in cardiac remodeling using cardiac-specific IKKβ deficient mice. Methods and Results: We crossed mice bearing an IKK β flox allele with mice expressing the Cre recombinase under the control of the myosin light chain 2v promoter ( MLC2v-Cre +/− ) to generate IKK β flox/flox ; MLC2v-Cre +/− mice (conditional knockout:CKO). Then, CKO mice (n=14) and control littermates bearing IKK β flox/flox (CTRL, n=14) were subjected to pressure overload by means of transverse aortic constriction (TAC). EMSA analysis revealed NF-κB DNA binding activity after TAC had attenuated in CKO hearts. One week after TAC, echocardiography showed significantly lower left ventricular fractional shortening (26.9±2.7% vs. 41.4±0.9%, p<0.01), and higher left ventricular end-diastolic dimension (4.02±0.14 mm vs. 3.47±0.08 mm, p<0.01) and lung weight/body weight ratio (11.1±1.4 vs. 5.5±0.1, p<0.01) in CKO mice compared with CTRL mice, indicating the development of heart failure in CKO mice. Number of apoptotic cells had increased in CKO hearts after TAC, suggesting that the enhanced apoptosis is a cause for heart failure. The expression levels of MnSOD mRNA and protein after TAC, which is one of NF-κB target genes, were significantly lower in CKO than those in CTRL mice. As a consequence, oxidative stress and JNK activation in CKO hearts after TAC had significantly increased compared with those in CTRL heart, suggesting that increased oxidative stress and enhanced JNK activity resulted in cardiomyocyte apoptosis in CKO hearts. Conclusion: These results show that IKKβ/NF-κB pathway in cardiomyocyte plays a protective role mediated through attenuation of oxidative stress and JNK activation in response to pressure overload.


2014 ◽  
Vol 115 (suppl_1) ◽  
Author(s):  
Dayue D Duan ◽  
Ying Yu ◽  
Guanlei Wang ◽  
Lingyu L Ye ◽  
Yi-gang Li

Backgrand: Myocardial hypertrophy causes an increase in myocyte volume and constitutive activation of a volume-sensitive outwardly-rectifying anion channel (VSORAC). The underlying molecular mechanisms and function of VSORAC in the electrical remodeling during myocardial hypertrophy and heart failure remain undefined. We tested whether cardiac CLC-3 chloride channels play a role in the hypertrophy-induced electrophysiological remodeling. Methods and Results: The age-matched CLC-3 knockout (Clcn3-/-) mice and their wild-type (Clcn3+/+) littermates were subjected to minimally-invasive transverse aortic banding (MTAB). In 77% (44/57) left ventricular (LV) myocytes isolated from MTAB-Clcn3+/+ mice a large VSORAC current was activated under isotonic conditions. Hypotonic cell-swelling caused no changes in the VSORAC but hypertonic cell-shrinkage significantly inhibited it. This constitutively-activated VSORAC had an anion selectivity of I->Cl->Asp-, and was inhibited by tamoxifen, PKC activation and intracellular application of anti-CLC-3 antibody. In the age-matched MTAB-Clcn3-/- mice, a significantly smaller outwardly-rectifying current was present in only 38% (36/94, P<0.05 vs MTAB-Clcn3+/+) LV myocytes. This current was neither increased by hypotonic stress nor inhibited by tamoxifen, PKC or anti-CLC-3 antibody, indicating not a VSORAC or CLC-3 current. Expression of CLC-3 protein was significantly increased in the LV tissues of MTAB-Clcn3+/+ mice but not in Sham-Clcn3+/+ and MTAB-Clcn3-/- mice. Both surface and intracardiac electrophysiological recordings revealed more atrial or ventricular arrhythmias in MTAB-Clcn3-/- mice than in MTAB- and Sham-Clcn3+/+ mice. Conclusions: Pressure-overload-induced myocardial hypertrophy causes an upregulation of CLC-3 expression and constitutive activation of CLC-3 may serve as a novel protective mechanism against the electrical remodeling during myocardial hypertrophy and heart failure.


2019 ◽  
Vol 316 (6) ◽  
pp. H1366-H1377
Author(s):  
Yoshifumi Okawa ◽  
Atsushi Hoshino ◽  
Makoto Ariyoshi ◽  
Satoshi Kaimoto ◽  
Shuhei Tateishi ◽  
...  

Despite the advances in medical therapy, the morbidity and mortality of heart failure (HF) remain unacceptably high. HF results from reduced metabolism–contraction coupling efficiency, so the modulation of cardiac metabolism may be an effective strategy for therapeutic interventions. Tumor suppressor p53 (TP53) and its downstream target TP53-induced glycolysis and apoptosis regulator (TIGAR) are known to modulate cardiac metabolism and cell fate. To investigate TIGAR’s function in HF, we compared myocardial, metabolic, and functional outcomes between TIGAR knockout (TIGAR−/−) mice and wild-type (TIGAR+/+) mice subjected to chronic thoracic transverse aortic constriction (TAC), a pressure-overload HF model. In wild-type mice hearts, p53 and TIGAR increased markedly during HF development. Eight weeks after TAC surgery, the left ventricular (LV) dysfunction, fibrosis, oxidative damage, and myocyte apoptosis were significantly advanced in wild-type than in TIGAR−/− mouse heart. Further, myocardial high-energy phosphates in wild-type hearts were significantly decreased compared with those of TIGAR−/− mouse heart. Glucose oxidation and glycolysis rates were also reduced in isolated perfused wild-type hearts following TAC than those in TIGAR−/− hearts, which suggest that the upregulation of TIGAR in HF causes impaired myocardial energetics and function. The effects of TIGAR knockout on LV function were also replicated in tamoxifen (TAM)-inducible cardiac-specific TIGAR knockout mice ( TIGARflox/flox/Tg(Myh6-cre/Esr1) mice). The ablation of TIGAR during pressure-overload HF preserves myocardial function and energetics. Thus, cardiac TIGAR-targeted therapy to increase glucose metabolism will be a novel strategy for HF. NEW & NOTEWORTHY The present study is the first to demonstrate that TP53-induced glycolysis and apoptosis regulator (TIGAR) is upregulated in the myocardium during experimental heart failure (HF) in mice and that TIGAR knockout can preserve the heart function and myocardial energetics during HF. Reducing TIGAR to enhance myocardial glycolytic energy production is a promising therapeutic strategy for HF.


Hypertension ◽  
2013 ◽  
Vol 62 (suppl_1) ◽  
Author(s):  
Scott Supowit ◽  
Prakash Gupta ◽  
Donald DiPette

We previously demonstrated that the potent antioxidant, resveratrol, significantly attenuates the adverse cardiac remodeling and dysfunction in pressure overload heart failure induced by transverse aortic constriction (TAC) in C57/BL6 mice. The purpose of this study was to identify the mechanisms that mediate the cardioprotective activities of resveratrol in this setting. Male C57BL6 mice (26-28 g) were subjected to either sham or TAC surgery. One group of TAC mice was given daily resveratrol treatment (oral gavage, 100 mg/kg/body weight for 28 days starting on day 2 after surgery. At the end of the protocol (28 days), the hearts were removed for analysis of markers of oxidative stress, inflammation, and apoptosis. Immunohistological staining for left ventricular (LV) 4-hydroxy-2-nonenal, a marker of lipid peroxidation was significantly elevated in the TAC mice (18.4±3.0 IOD/μm 2 ) compared to sham mice (3.4±1.0). Resveratrol treatment significantly attenuated this increase (14.4±2.0). In contrast, LV content of the antioxidant glutathione was significantly decreased in the TAC mice (5.3±0.2 nM/mg protein) compared to the sham mice (8.5±0.2). Resveratrol treatment significantly increased glutathione (7.6±0.3) to near sham levels. Likewise, LV activity of sodium oxide dismutase 2 was markedly reduced in TAC mice (7.3±0.9 U/mg protein) compared to sham mice (10.7±1.3) and was significantly increased by resveratrol treatment (7.6±0.3). LV macrophage and mast cell infiltration was markedly increased in the TAC mice (14.8±0.1 and 12.6±0.0 %) compared to sham mice (1.7±0.1 and 2.6±0.1). This increase was significantly attenuated by resveratrol administration (10.4±0.1 and 8.0±0.1). Apoptotic cell death, as determined by the TUNEL assay, was also increased in the TAC mice (0.13±0.01 % cells) compared to sham mice (0.01±0.01). This increase was significantly attenuated in the resveratrol treated group (0.06±0.01). A similar pattern was observed when activated LV caspase-3, a second marker of apoptosis, was measured. In conclusion, these data indicate that the cardioprotective effects of resveratrol in pressure overload-induced heart failure are mediated through the inhibition of oxidative stress, inflammation, and apoptotic cell death.


2021 ◽  
Vol 12 ◽  
Author(s):  
Hongyang Shu ◽  
Weijian Hang ◽  
Yizhong Peng ◽  
Jiali Nie ◽  
Lujin Wu ◽  
...  

Energic deficiency of cardiomyocytes is a dominant cause of heart failure. An antianginal agent, trimetazidine improves the myocardial energetic supply. We presumed that trimetazidine protects the cardiomyocytes from the pressure overload-induced heart failure through improving the myocardial metabolism. C57BL/6 mice were subjected to transverse aortic constriction (TAC). After 4 weeks of TAC, heart failure was observed in mice manifested by an increased left ventricular (LV) chamber dimension, an impaired LV ejection fraction evaluated by echocardiography analysis, which were significantly restrained by the treatment of trimetazidine. Trimetazidine restored the mitochondrial morphology and function tested by cardiac transmission electron microscope and mitochondrial dynamic proteins analysis. Positron emission tomography showed that trimetazidine significantly elevated the glucose uptake in TAC mouse heart. Trimetazidine restrained the impairments of the insulin signaling in TAC mice and promoted the translocation of glucose transporter type IV (GLUT4) from the storage vesicle to membrane. However, these cardioprotective effects of trimetazidine in TAC mice were notably abolished by compound C (C.C), a specific AMPK inhibitor. The enlargement of neonatal rat cardiomyocyte induced by mechanical stretch, together with the increased expression of hypertrophy-associated proteins, mitochondria deformation and dysfunction were significantly ameliorated by trimetazidine. Trimetazidine enhanced the isolated cardiomyocyte glucose uptake in vitro. These benefits brought by trimetazidine were also removed with the presence of C.C. In conclusion, trimetazidine attenuated pressure overload-induced heart failure through improving myocardial mitochondrial function and glucose uptake via AMPK.


2020 ◽  
Vol 18 (3) ◽  
pp. 260-265
Author(s):  
Xu Lin ◽  
Zheng Xiaojun ◽  
Lv Heng ◽  
Mo Yipeng ◽  
Tong Hong

The purpose of this study was to evaluate the protective effect of swertiamarin on heart failure. To this end, a rat model of heart failure was established via left coronary artery ligation. Infarct size of heart tissues was determined using triphenyl tetrazolium chloride staining. Echocardiography was performed to evaluate cardiac function by the determination of ejection fraction, left ventricular internal dimension in diastole and left ventricular internal dimension in systole. The effect of swertiamarin on oxidative stress was evaluated via enzyme-linked immunosorbent assay. The mechanism was evaluated using western blot. Administration of swertiamarin reduced the infarct size of heart tissues in rat models with heart failure. Moreover, swertiamarin treatment ameliorated the cardiac function, increased ejection fraction and fractional shortening, decreased left ventricular internal dimension in diastole and left ventricular internal dimension in systole. Swertiamarin improved oxidative stress with reduced malondialdehyde, while increased superoxide dismutase, glutathione, and GSH peroxidase. Furthermore, nuclear-factor erythroid 2-related factor 2, heme oxygenase and NAD(P)H dehydrogenase (quinone 1) were elevated by swertiamarin treatment in heart tissues of rat model with heart failure. Swertiamarin alleviated heart failure through suppression of oxidative stress response via nuclear-factor erythroid 2-related factor 2/heme oxygenase-1 pathway providing a novel therapeutic strategy for heart failure.


2017 ◽  
Vol 68 (7) ◽  
pp. 1506-1511
Author(s):  
Cerasela Mihaela Goidescu ◽  
Anca Daniela Farcas ◽  
Florin Petru Anton ◽  
Luminita Animarie Vida Simiti

Oxidative stress (OS) is increased in chronic diseases, including cardiovascular (CV), but there are few data on its effects on the heart and vessels. The isoprostanes (IsoP) are bioactive compounds, with 8-iso-PGF25a being the most representative in vivo marker of OS. They correlate with the severity of heart failure (HF), but because data regarding OS levels in different types of HF are scarce, our study was aimed to evaluate it by assessing the urinary levels of 8-iso-PGF2aand its correlations with various biomarkers and parameters. Our prospective study included 53 consecutive patients with HF secondary to ischemic heart disease or dilative cardiomyopathy, divided according to the type of HF (acute, chronic decompensated or chronic compensated HF). The control group included 13 hypertensive patients, effectively treated. They underwent clinical, laboratory - serum NT-proBNP, creatinine, uric acid, lipids, C reactive protein (CRP) and urinary 8-iso-PGF2a and echocardiographic assessment. HF patients, regardless the type of HF, had higher 8-iso-PGF2a than controls (267.32pg/�mol vs. 19.82pg/�mol, p[0.001). The IsoP level was directly correlated with ejection fraction (EF) (r=-0.31, p=0.01) and NT-proBNP level (r=0.29, p=0.019). The relative wall thickness (RWT) was negatively correlated with IsoP (r=-0.55, p[0.001). Also 8-iso-PGF25a was higher by 213.59pg/�mol in the eccentric left ventricular (LV) hypertrophy subgroup comparing with the concentric subgroup (p=0.014), and the subgroups with severe mitral regurgitation (MR) and moderate/severe pulmonary hypertension (PAH) had the highest 8-iso-PGF2a levels. Male sex, severe MR, moderate/severe PAH, high LV mass and low RWT values were predictive for high OS level in HF patients.Eccentric cardiac remodeling, MR severity and PAH severity are independent predictors of OS in HF patients.


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