Dapagliflozin ameliorates myocardial infarction injury through AMPKα-dependent regulation of oxidative stress and apoptosis.

Dapagliflozin (DAPA) has been demonstrated to reduce cardiovascular mortality and heart failure hospitalization rates in diabetic patients. However, the mechanism underlying its cardio-protective effect in non-diabetic patients remains unclear. Our study aimed to explore the cardio-protective impact of DAPA on myocardial infarction in non-diabetic mice. We induced myocardial infarction in C57BL/6 mice by ligating the descending branch of the left coronary artery. After surgery, the animals were randomly treated with either saline or DAPA. We employed echocardiography, Western blot analysis, and tissue staining to assess post-infarction myocardial injury. Additionally, we investigated the mechanism of action through cell experiments. Compared to the myocardial infarction group, DAPA treatment significantly attenuated ventricular remodeling and improved cardiac function. By mitigating myocardial oxidative stress and apoptosis, DAPA may activate the AMPKα signaling pathway, thereby exerting a protective effect. These findings suggest that DAPA could serve as a novel therapeutic approach for patients with cardiac infarction.

Prognostic value of red cell distribution width in non-ST elevation myocardial infarction: A cohort study.

Non-ST elevation myocardial infarction (NSTEMI) has a higher risk of long-term mortality than ST-elevation myocardial infarction; thus, identifying such high-risk patients is essential. Red cell distribution width (RDW) recently emerged as a strong predictor of mortality in several cardiovascular diseases, however, it is scarcely known whether RDW has a prognostic value in NSTEMI patients, therefore, this study aims to elucidate this issue. 421 consecutive patients with NSTEMI between January 2020 and June 2022 were prospectively enrolled. Patients were divided into 2 groups by the optimal cutoff value of RDW using time-dependent receiver operating characteristic curves. The optimal cutoff value of RDW for predicting all-cause mortality was 13.4 and the study population was divided into low RDW (≤13.4) and high RDW (>13.4). The primary endpoint of this study was long-term all-cause mortality. The secondary endpoint was the association between RDW and long-term adverse events, including heart failure, gastrointestinal hemorrhage, stroke events, re-infarction rate, cardiovascular mortality, and major adverse cardiovascular events. The association of RDW with the outcome was analyzed by Cox regression analysis. Patients with high RDW tended to be older, had a higher history of previous MI, a higher history of percutaneous coronary intervention, a higher level of neutrophil, high-sensitivity C-reactive protein, a lower level of albumin, and a lower level of ejection fraction (all P < .05). During a median follow-up of 720 days (IQR, 534-913 days), the all-cause mortality was significantly higher in the high RDW group than in the low RDW group (24.8% vs 6.3%, P < .001). In the multivariate Cox proportional hazard analysis, RDW > 13.4 was an independent predictor for long-term all-cause mortality [hazard ratio 3.008; 95% confidence interval 1.005, 9.003, P = .049]. Admission RDW could be used as a new biomarker for predicting long-term mortality in patients with NSTEMI, and high RDW was associated with an increased risk of all-cause mortality.

LncRNA GAS5 downregulates NLRP3 inflammasome activation-mediated pyroptosis in sepsis-induced myocardial injury by targeting SIRT3/AMPKα.

An increasing body of studies has demonstrated the significance of long non-coding RNA (lncRNA) growth arrest specific 5 (GAS5) in inflammation and myocardial injury in septic shock. This research aims to determine whether GAS5 contributes to the pathological development of sepsis-induced cardiac damage and NLRP3 inflammasome-mediated myocardial cell pyroptosis. Cecal ligation and puncture (CLP) surgery was used to cause septic shock in C57BL/6 wild-type mice. After CLP, inflammatory, pyroptosis parameters of myocardial tissue, survival rate, and Murine Sepsis Score (MSS) were assessed to evaluate the involvement of GAS5 in the mouse myocardial depression. To investigate GAS5's function in lipopolysaccharide (LPS) induced myocardial cell pyroptosis, gain- and loss-of-function experiments were conducted in vitro on HL-1 cells. Our findings indicated that CLP dramatically reduced survival rates, MSS, SIRT3 and p-AMPK expression, and activated the Nuclear factor-κB (NF-κB) pathway and NLRP3 inflammasome-mediated pyroptosis. The NF-κB and pyroptosis pathways were greatly elevated while SIRT3/p-AMPKα was dramatically decreased as a result of GAS5 being downregulated. Meanwhile, the regulatory effect could be suppressed by SIRT3 and AMPKα activator. Our observations supported the idea that GAS5 has a crucial protective impact against myocardial inflammation and pyroptosis in sepsis.

iNOS contributes to heart failure with preserved ejection fraction through mitochondrial dysfunction and Akt S-nitrosylation.

INTRODUCTION: Despite the high morbidity and mortality of heart failure with preserved fraction (HFpEF), there are currently no effective therapies for this condition. Moreover, the pathophysiological basis of HFpEF remains poorly understood. OBJECTIVE: The aim of the present study was to investigate the role of inducible nitric oxide synthase (iNOS) and its underlying mechanism in a high-fat diet and Nω-nitro-L-arginine methyl ester-induced HFpEF mouse model. METHODS: The selective iNOS inhibitor L-NIL was used to examine the effects of short-term iNOS inhibition, whereas the long-term effects of iNOS deficiency were evaluated using iNOS-null mice. Cardiac and mitochondrial function, oxidative stress and Akt S-nitrosylation were then measured. RESULTS: The results demonstrated that both pharmacological inhibition and iNOS knockout mitigated mitochondrial dysfunction, oxidative stress and Akt S-nitrosylation, leading to an ameliorated HFpEF phenotype in mice. In vitro, iNOS directly induced Akt S-nitrosylation at cysteine 224 residues , leading to oxidative stress, while inhibiting insulin-mediated glucose uptake in myocytes. CONCLUSION: Altogether, the present findings suggested an important role for iNOS in the pathophysiological development of HFpEF, indicating that iNOS inhibition may represent a potential therapeutic strategy for HFpEF.

Esomeprazole inhibits endoplasmic reticulum stress and ameliorates myocardial ischemia-reperfusion injury.

Proton pump inhibitors (PPIs) are often prescribed in association with clopidogrel and aspirin to patients with myocardial infraction (MI), but their effects on heart is controversial. The purpose of this study was to investigate the effects and potential mechanism of omeprazole (OME) and esomeprazole (ESO) in myocardial ischemia reperfusion (I/R) injury. In the present study, mice were treated with OME, ESO or vehicle for 3 weeks and then subjected to myocardial I/R or sham surgery. At 1 day after surgery, echocardiography was performed to access cardiac injury. Hematoxylin and eosin (H&E) staining was performed to evaluate cardiomyocyte morphology. The IL1ß was evaluated by Immunohistochemistry (IHC). Elisa was used to detect cTnt content in serum. The expression of CD86, CD206, CHOP, ATF6, eIF2α and p eIF2α were determined by Western blot (WB). The result showed that ESO markedly improved the left ventricular ejection fraction (LVEF), shortening fraction (FS), suppressed inflammatory infiltration, endoplasmic reticulum stress (ERS) and decreased proinflammatory macrophages in I/R hearts, while OME had no significant effects on cardiac function, inflammation and ERS in the I/R heart. In conclusion, ESO but not OME pretreatment reduces the proportion of proinflammatory macrophages, inhibits endoplasmic reticulum stress, and alleviates I/R injury in mice, indicating that ESO maybe a more proper PPI than OME for application in I/R injury.