Carnosic Acid Protects Against Myocardial Infarction by Controlling Oxidative Stress and Inflammation in Rats

3-Hydroxyl-3-methylglutaryl coenzyme A reductase inhibitors (statins) have been shown to reduce the incidence of myocardial infarction independent of their lipid-lowering effects. Nitric oxide (NO) in the central nervous system contributes to cardiovascular regulatory mechanisms. Imbalance between nitric oxide (NO) and superoxide anion (O 2 . − ) in the brain may contribute to enhanced sympathetic drive in heart failure (HF). This study was done to determine whether treatment with atorvastatin (ATS) ameliorates the imbalance between NO and O 2 . − production in the brain stem and contributes to improvement of left ventricular (LV) function. Methods and Results: Myocardial infarction (MI) was induced by ligation of the left coronary artery or sham surgery. Subsequently, mice were treated with ATS (10 μg/kg) (MI + ATS), or vehicle (MI + V). After 5 weeks, echocardiography revealed left ventricular dilatation in MI mice. Realtime RT-PCR indicated an increase in the mRNA expression of the LV hypertrophy markers, atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP). Neuronal NOS (nNOS) and endothelial NOS (eNOS) mRNA expression were significantly reduced, while that of NAD(P)H oxidase subunit (gp91phox) expression was elevated in the brain stem of MI mice. Compared with sham-operated mice, ATS-treated mice showed reduced cardiac dilatation, decreased ANP and BNP in the LV. ATS also reduced gp91phox expression and increased nNOS mRNA expression in the brain stem, while no changes in eNOS and iNOS were observed. Conclusion: These findings suggest that ATS reduces oxidative stress and increases neuronal NOS in the brain stem, and improves left ventricular function in heart failure.

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Abstract 265: Uroetensin II Protects Cardiomyocytes from Apoptosis Induced by Oxidative Stress through Cystathionine-γ-Lyase (CSE)/Hydrogen Sulfide Pathway

Circulation Research ◽

10.1161/res.115.suppl_1.265 ◽

2014 ◽

Vol 115 (suppl_1) ◽

Author(s):

Hui Gong ◽

Zhidan Chen ◽

Xiaoyi Zhang ◽

Jie Zhang ◽

Yang Li ◽

...

Keyword(s):

Oxidative Stress ◽

Myocardial Infarction ◽

Acute Myocardial Infarction ◽

Erk Signaling ◽

Cardiac Protection ◽

Health Control ◽

Cardiology Department ◽

Apoptotic Protein ◽

Induced Apoptosis ◽

H2s Production

Plasma UII has been observed to be raised in patients with acute myocardial infarction, a lower UII response is associated with more severe injury of myocardium, suggesting a possible cardioprotective role for this peptide. In the present study, we studied plasma UII concentration of thirty patients admitted to the Cardiology Department with acute myocardial infartion.The results showed that plasma UII was sharply increased in patients compared to that in health control within one week after admission. We then explore whether UII could protect cardiomyocytes from injury induced by oxidative stress. Cultured cardiomyocyte were treated with H2O2 to induce oxidative stress, and the influence of UII on H2O2-induced apoptosis was observed. The results showed that UII pretreatment significantly reduced the number of TUNEL-positive cardiomyocytes induced by H2O2, and it partly abolished the upregulation of pro-apoptotic protein Bax and the down-regulation of anti-apoptotic protein Bcl-2. siRNA targeted to urotensin receptor (UT) greatly inhibited these effects. H2S has been reported to exert protective effect on cardiomyocytes, we detected the effect of UII on H2S production and CSE (Major H2S-producing enzyme) expressions in cardiomyocytes exposed to H2O2.The present data revealed that UII increased the H2S production by enhancing the expression of CSE by activating the ERK signaling in cardiomyocytes exposed to H2O2. Si-CSE or ERK inhibitor not only greatly inhibited the upregulation of CSE or the phosphorylation of ERK induced by UII but also reversed UII-induced-upregulation of H2S production and anti-apoptosis in cadiomyocytes exposed to H2O2. In conclusion, UII rapidly promoted the phosphorylation of ERK, increased CSE exression and induced H2S production, which in turn enhanced the p-ERK level to protect cardiomyocytes from apoptosis under ischemic or oxidative stress. The increased plasma UII level in patients may be critical for cardiac protection in patients at early-phase of acute myocardial infarction.

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