Search

Myocardial infarction arises from an excessive or prolonged inflammatory response, leading to ventricular remodeling or impaired cardiac function. Macrophages exhibit different polarization types associated with inflammation both at steady state and after myocardial infarction. Exosomal miR-146a-5p has been identified as an important molecule in the cardiovascular field in recent years. However, the effect of cardiomyocyte-derived exosomal miR-146a-5p on macrophages has not yet been elucidated. Initially, we found that exosomes with low expression of miR-146a-5p derived from myocardial infarction tissues modulated macrophage polarization. To determine whether cardiomyocyte-derived exosomal miR-146a-5p mediated macrophage polarization, we treated macrophages with exosomes rich in miR-146a-5p collected from neonatal mouse cardiomyocytes. The effects of exosomal miR-146a-5p on macrophage polarization were measured using RT-qPCR, transwell assays, and western blotting. The results showed that the increased expression of miR-146a-5p promoted M1 macrophage polarization, inhibited M2 macrophage polarization, and increased the expression of VEGFA. However, the decreased expression of exosomalmiR-146a-5p showed the opposite trends. Interestingly, in contrast to treatment with the solitary miR-146a-5p mimic, exosomal miR-146a-5p derived from neonatal mouse cardiomyocytes reduced TNFα and iNOS expression. In addition, when macrophages were activated by the miR-146a-5p mimic or exosomal miR-146a-5p, the expression of TNF receptor-associated factor 6 (TRAF6), a target gene of miR-146a-5p, was reduced significantly. Taken together, these findings indicate that exosomal miR-146a-5p derived from cardiomyocytes could stimulate M1 macrophage polarization to induce an inflammatory reaction, while targeting TRAF6, exerting an anti-inflammatory effect. Exosomal miR-146a-5p plays important roles in macrophages, illuminating a novel potential therapeutic target in myocardial infarction.

This study primarily explored the role of paeonol in doxorubicin (DOX)-induced chronic heart failure (CHF), considering the cardioprotective effect of paeonol on an epirubicin-induced cardiac injury.DOX-induced CHF-modeled rats were treated with paeonol. Cardiac function and myocardial damage in rats were evaluated by using the multifunction instrument, and the histopathology, apoptosis, and the expression of miR-21-5p and S-phase kinase-associated protein 2 (SKP2) in myocardium were detected. The target gene of miR-21-5p was confirmed by a dual-luciferase reporter assay. After the required transfection or paeonol treatment, the viability, apoptosis, mitochondrial membrane potential (MMP), and reactive oxygen species (ROS) of the DOX-induced cardiomyocytes were determined. Reverse-transcription quantitative-PCR (RT-qPCR) and Western blot were performed to quantify the expressions of miR-21-5p, SKP2, and apoptosis-related factors.Paeonol improved cardiac function and also ameliorated the cardiac damage of CHF-modeled rats, where the downregulation of abnormally elevated myocardial damage markers, including brain natriuretic peptide, lactate dehydrogenase, renin, angiotensin II, aldosterone, and endothelin 1, was observed. Paeonol alleviated the histopathological injury and suppressed the apoptosis in CHF-modeled rats, inhibited miR-21-5p expression, and upregulated SKP2 expressionPaeonol shows a cardioprotective effect on DOX-induced CHF

Refractory and resistant hypertension is defined as hypertension that is uncontrolled despite the use of multiple antihypertensives. The aim of the present study is to evaluate the prevalence, both in young and elderly, and the pattern of left ventricular hypertrophy (LVH) in South-Eastern Chinese patients with refractory, resistant and non-resistant hypertension.A total of 1455 patients (age 60.3 ± 13.9, male 55.7%) with essential hypertension were recruited. Refractory hypertension was defined as uncontrolled blood pressure (systolic/diastolic, ≥140/90 mm Hg) on ≥5 antihypertensive drug classes. Resistant hypertension was defined as uncontrolled blood pressure (systolic/diastolic, ≥140/90 mm Hg) on 3 or140/90 mm Hg on ≥4 antihypertensive classes.Among the total population, 1273 (87.4%) patients were considered non-resistant hypertension; 170 (11.7%) with resistant hypertension and 12 (0.8%) with refractory hypertension. The prevalence of the three groups of hypertension were similar between patients age60 or ≥60. Patients with refractory hypertension had the most dilated LV dimension, greatest left ventricular mass index and highest prevalence of diastolic dysfunction than patients with resistant and non-resistant hypertension. In particular, all patients with refractory hypertension had either concentric or eccentric LVH.In South-Eastern Chinese patients, the prevalence of refractory and resistant hypertension was 0.8% and 11.7%, respectively. Furthermore, no difference was observed in the hypertensive patterns between patients age60 and ≥60. Importantly, patients with refractory hypertension had the worst LV remodeling with all suffering from either concentric or eccentric hypertrophy.

A non-dipper pattern of high blood pressure is associated with increased risk of organ damage and cardiovascular disease in patients with hypertension. The aim of the study was to evaluate the left ventricular (LV) remodeling and function and arterial stiffness in a dipper/non-dipper pattern of high blood pressure in patients with hypertension. A total of 183 hypertensive patients with no history of adverse cardiovascular events were divided into two groups based on 24 hours ambulatory blood pressure monitoring (ABPM): 66 patients with a dipper pattern and 117 patients with non-dipper pattern. Detailed transthoracic echocardiogram was performed and analyzed with advance speckle tracking 3-orthogonal direction strain analysis to assess LV systolic function and tissue Doppler-derived E/E′ for LV diastolic function assessment. Cardio ankle vascular index (CAVI) was used to evaluate arterial stiffness. Compared with patients with dipper hypertension, those with non-dipper hypertension had increased LV mass index, higher prevalence of eccentric and concentric LV hypertrophy, more impaired LV diastolic and systolic function and peripheral arterial stiffness. Multivariable analysis revealed that a non-dipper pattern was independently associated with LV systolic dysfunction evaluated by speckle tracking-derived strain analysis. In conclusion, a non-dipper pattern of hypertension is an independent risk factor for LV systolic dysfunction. Treatment that could reverse this non-dipper pattern may reduce cardiac damage in these patients.