MicroRNA-92b-3p suppresses angiotensin II-induced cardiomyocyte hypertrophy via targeting HAND2.

AIMS: The pathological cardiac hypertrophy will develop into heart failure, which has no effective treatment currently. Previous studies have proved that microRNAs (miRNAs) participate in the development of cardiac hypertrophy and regulate the pathological progress. In this study, we want to investigate the role of microRNA-92b-3p (miR-92b-3p) in cardiomyocyte hypertrophy and the mechanisms involved. MATERIALS AND METHODS: Neonatal mouse ventricular cells (NMVCs) were isolated from the hearts of 1-3-d-old newborn C57BL6 mice. The isolated NMVCs were induced hypertrophic phenotype by Angiotensin-II (Ang-II) and the cell size was examined by FITC-phalloidin staining assay. The expression of miR-92b-3p was determined by quantitative real-time PCR (qRT-qPCR). MRNA and protein level of ß-MHC, ACTA1 and HAND2 in NMVCs transfected with miR-92b-3p mimic and inhibition were assessed by RT-qPCR assay and western blot assay, respectively. Dual luciferase assay was used to verify the interaction between miR-92b-3p and the 3'-untranslated region (UTR) of HAND2 gene. KEY FINDINGS: MiR-92b-3p and HAND2 were significantly increased in Ang-II-induced NMVCs. Overexpression of miR-92b-3p can ameliorate Ang-II-induced cardiomyocyte hypertrophy. MiR-92b-3p negatively regulated HAND2 expression at the transcriptional level. Both miR-92b-3p mimic and HAND2 siRNA could efficiently inhibit Ang-II-induced hypertrophy in mouse cardiomyocytes. SIGNIFICANCE: MiR-92b-3p inhibits Ang-II-induced cardiomyocyte hypertrophy via targeting HAND2.

Targeting myocyte-specific enhancer factor 2D contributes to the suppression of cardiac hypertrophic growth by miR-92b-3p in mice.

The role of microRNA-92b-3p (miR-92b-3p) in cardiac hypertrophy was not well illustrated. The present study aimed to investigate the expression and potential target of miR-92b-3p in angiotensin II (Ang-II)-induced mouse cardiac hypertrophy. MiR-92b-3p was markedly decreased in the myocardium of Ang-II-infused mice and of patients with cardiac hypertrophy. However, miR-92b-3p expression was revealed increased in Ang-II-induced neonatal mouse cardiomyocytes. Cardiac hypertrophy was shown attenuated in Ang-II-infused mice received tail vein injection of miR-92b-3p mimic. Moreover, miR-92b-3p inhibited the expression of atrial natriuretic peptide (ANP), skeletal muscle α-actin (ACTA1) and ß-myosin heavy chain (MHC) in Ang-II-induced mouse cardiomyocytes in vitro. Myocyte-specific enhancer factor 2D (MEF2D), which was increased in Ang-II-induced mouse hypertrophic myocardium and cardiomyocytes, was identified as a target gene of miR-92b-3p. Functionally, miR-92b-3p mimic, consistent with MEF2D siRNA, inhibited cell size increase and protein expression of ANP, ACTA1 and ß-MHC in Ang-II-treated mouse cardiomyocytes. Taken together, we demonstrated that MEF2D is a novel target of miR-92b-3p, and attenuation of miR-92b-3p expression may contribute to the increase of MEF2D in cardiac hypertrophy.

Prevalence and determinants of left ventricular geometric abnormalities in hypertensive patients: A study based on the updated classification system of left ventricular geometry.

OBJECTIVE: This study was to determine whether different risk factors were associated with different type of left ventricular (LV) geometric abnormalities. METHODS: This retrospective analysis included 2290 hypertensive participants without other cardiovascular disease, valve disease and with ejection fraction ≥50%. The type of LV geometric abnormality was defined on the basis of the new classification system. RESULTS: LV geometric abnormalities were detected in 1479 subjects (64.6%), wherein concentric LV remodeling is the most common LV geometric abnormality (40.3%). Large waist circumference (WC) and neck circumference (NC) were positively associated with concentric LV remodeling, whereas body mass index (BMI) [odds ratio (OR) 0.89, 95% CI 0.85∼0.92, P ＜ 0.001] and systolic blood pressure (SBP) (OR 0.99, 95% CI 0.98∼0.99, P = 0.018) were inversely associated with concentric abnormalities. SBP and age were positively associated with eccentric dilated LVH, while male was inversely associated with eccentric dilated left ventricular hypertrophy (LVH). Age was the strongest risk factor for eccentric dilated LVH (OR 1.05, 95% CI 1.03∼1.07, P ＜ 0.001). Age, NC, SBP, hyperuricemia, and alcohol use were positively associated with concentric LVH, whereas BMI (OR 0.95, 95% CI 0.90∼0.99, P = 0.033) and male (OR 0.12, 95% CI 0.07∼0.18, P ＜ 0.001) were negatively associated with concentric LVH. CONCLUSION: The prevalence of hypertensive LV geometric abnormality in rural area of Southern China was obvious higher. Compared with eccentric LV geometric abnormalities, there were more risk factors, including large WC and NC, age, NC, SBP, hyperuricemia, alcohol use, BMI and gender, which were associated with concentric LV geometric abnormalities.

Association of Serum Omentin-1 Concentrations with the Presence of Atrial Fibrillation.

BACKGROUND Omentin-1 is one of the adipokines associated with obesity, diabetes, and coronary heart disease development. We determined to investigate whether serum omentin-1 concentrations were correlated with the presence of atrial fibrillation (AF). MATERIAL AND METHODS Serum omentin-1 concentrations were examined in a cross-sectional population that included 220 patients with AF (70 with paroxysmal AF, 78 with persistent AF, and 72 with permanent AF) and 115 healthy controls. RESULTS Reduced serum omentin-1 concentrations were found in AF patients compared to the controls. In addition, patients with permanent AF had lower serum omentin-1 concentrations compared to patients with persistent AF and patients with paroxysmal AF. Significantly decreased serum omentin-1 concentrations were observed in persistent AF patients compared to paroxysmal AF patients. Spearman correlation analysis suggested that serum omentin-1 concentrations were negatively correlated with left atrial diameter in AF patients. CONCLUSIONS Serum omentin-1 concentrations were correlated with the presence of AF and atrial remolding.