Tetrandrine downregulates TRPV2 expression to ameliorate myocardial ischemia/reperfusion injury in rats via regulation of cardiomyocyte apoptosis, calcium homeostasis and mitochondrial function.

Our previous study has indicated that tetrandrine (TET) can target miR-202-5p to repress the activation of transient receptor potential vanilloid type 2 (TRPV2), eventually ameliorating the progression of myocardial ischemia/reperfusion injury (MI/RI). This study is aimed to further ascertain the detailed mechanisms between TET and TRPV2 in MI/RI pathogenesis. Here, a myocardial I/R injury rat model and a hypoxia-reoxygenation (H/R) model in rat myocardial cell line (H9C2 cells) were established. We reported that pronounced upregulation of TRPV2 was observed in I/R rats and H/R-induced H9C2 cells. Silencing of TRPV2 could improve cardiac function and myocardial injury, reduced infarction size, and promoted cardiomyocyte proliferation in I/R rats. In I/R rats or H/R-induced H9C2 cells, cardiomyocyte apoptosis was inhibited by knocking-down TRPV2. Meanwhile, the silenced TRPV2 or TET treatment ameliorated the damaged mitochondrial structure, mitigated ROS generation, restored the impaired ΔΨM, inhibited mPTP opening and alleviated Ca2+ overload in H/R-induced H9C2 cells. The results obtained from the overexpression of TRPV2 were contrary to those depicted above. Moreover, TET could downregulate TRPV2 expression, while the overexpression of TRPV2 could reverse the above protective effects of TET in H/R-induced H9C2 cells. The results indicated that TET may function as a TRPV2 blocking agent, thereby attenuating the progression of MI/RI through modulation of cardiomyocyte apoptosis, calcium homeostasis and mitochondrial function. These findings offer a theoretical foundation for potential clinical application of TET therapy in patients with MI/RI.

Targeting Circulating lncRNA ENST00000538705.1 Relieves Acute Coronary Syndrome via Modulating ALOX15.

Objective: Acute coronary syndrome (ACS) is the most dangerous and deadly form of coronary heart disease. Herein, we aimed to explore ACS-specific circulating lncRNAs and their regulatory mechanisms. Methods: This study collected serum samples from ACS patients and healthy controls for microarray analysis. Dysregulated circulating lncRNAs and mRNAs were determined with |log2fold - change| > 1 and p < 0.05. lncRNA-mRNA coexpression analysis was carried out. ENST00000538705.1 and ALOX15 expression was further verified in serum specimens. In human coronary artery endothelial cells (HCAECs), ENST00000538705.1 and ALOX15 were knocked out through transfecting specific siRNAs. Thereafter, proliferation and migration were investigated with CCK-8 and wound-healing assays. Myocardial infarction rat models were established and administrated with siRNAs against ENST00000538705.1 or ALOX15. Myocardial damage was investigated with H&E staining, and serum TC, LDL, and HDL levels were measured. Results: Microarray analysis identified 353 dysregulated circulating lncRNAs and 441 dysregulated circulating mRNAs in ACS. Coexpression analysis indicated the interaction between ENST00000538705.1 and ALOX15. RT-qPCR confirmed the remarkable upregulation of circulating ENST00000538705.1 and ALOX15 in ACS patients. In HCAECs, ENST00000538705.1 knockdown lowered the expression of ALOX15 but ALOX15 did not alter the expression of ENST00000538705.1. Silencing ENST00000538705.1 or ALOX15 weakened the proliferation and migration of HCAECs. Additionally, knockdown of ENST00000538705.1 or ALOX15 relieved myocardial damage, decreased serum TC and LDL levels, and elevated HDL levels in myocardial infarction rats. Conclusion: Collectively, our findings demonstrate that circulating ENST00000538705.1 facilitates ACS progression through modulating ALOX15, which provide potential targets for ACS treatment.

Efficacy and safety of sacubitril valsartan in treating heart failure with midrange ejection fraction after acute myocardial infarction in diabetic patients.

ABSTRACT: Objective to evaluate the clinical efficacy and safety of sacubitril valsartan in the treatment of heart failure (HF) with midrange ejection fraction after acute myocardial infarction (AMI) in diabetic patients. From January 2015 to July 2020, HF patients with diabetes mellitus complicated with AMI were retrospectively analyzed. According to the medication, they were divided into 2 groups, that is, sacubitril valsartan group (84 cases) and valsartan group (86 cases). Valsartan group took valsartan capsule (80 mg/capsule, Beijing Novartis Pharmaceutical Co., Ltd) 80 mg, qd, on the basis of routine treatment. On the basis of routine treatment, the sacubitril valsartan group took sacubitril valsartan sodium tablets (50 mg/tablet, Beijing Novartis Pharmaceutical Co., Ltd), the initial dose was 25 mg, bid, and gradually increased to the target dose according to the patient's blood pressure. After 12 months of treatment, the independent sample t test showed that the left ventricular end diastolic dimension in the sacubitril valsartan group was lower than that in the valsartan group [(47.26 ±â€Š4.71) mm vs (50.05 ±â€Š5.62) mm, P < .001]. The left ventricular ejection fraction in the sacubitril valsartan group was higher than that in the valsartan group [(54.76 ±â€Š4.24)% vs (49.28 ±â€Š3.74)%, P < .001]. χ2 inspection showed that the readmission rate in the sacubitril valsartan group was lower than that in the valsartan group (7.14% vs 18.60%, P < .05). Sacubitril valsartan has good safety and tolerability in patients with diabetes mellitus complicated with AMI who have HF with midrange ejection fraction. Compared with valsartan, sacubitril valsartan can improve the left ventricular function better and reduce the readmission rate due to HF in these patients.