This study was aimed at investigating the effects of lncRNA AK139328 on myocardial ischaemia/reperfusion injury (MIRI) in diabetic mice. Ischaemia/reperfusion (I/R) model was constructed in normal mice (NM) and diabetic mice (DM). Microarray analysis was utilized to identify lncRNA AK139328 overexpressed in DM after myocardial ischaemia/reperfusion (MI/R). RT‐qPCR assay was utilized to investigate the expressions of lncRNA AK139328 and miR‐204‐3p in cardiomyocyte and tissues. Left ventricular end diastolic diameter (LVEDD), left ventricular end systolic diameter (LVESD), left ventricular ejection fraction (LVEF) and fractioning shortening (FS) were obtained by transthoracic echocardiography. Haematoxylin‐eosin (HE) staining and Masson staining were utilized to detect the damage of myocardial tissues degradation of myocardial fibres and integrity of myocardial collagen fibres. Evans Blue/TTC staining was used to determine the myocardial infarct size. TUNEL staining was utilized to investigate cardiomyocyte apoptosis. The targeted relationship between lncRNA AK139328 and miR‐204‐3p was confirmed by dual‐luciferase reporter gene assay. MTT assay was used for analysis of cardiomyocyte proliferation. Western blot was utilized to investigate the expression of alpha smooth muscle actin (α‐SMA), Atg7, Atg5, LC3‐II/LC3‐I and p62 marking autophagy. Knockdown of lncRNA AK139328 relieved myocardial ischaemia/reperfusion injury in DM and inhibited cardiomyocyte autophagy as well as apoptosis of DM. LncRNA AK139328 modulated miR‐204‐3p directly. MiR‐204‐3p and knockdown of lncRNA AK139328 relieved hypoxia/reoxygenation injury via inhibiting cardiomyocyte autophagy. Silencing lncRNA AK139328 significantly increased miR‐204‐3p expression and inhibited cardiomyocyte autophagy, thereby attenuating MIRI in DM.

With an increasing global burden of coronary artery disease (CAD), early detection and timely management of risk factors are crucial to reduce morbidity and mortality in such patients. Diabetes mellitus (DM) is considered an independent risk factor for the development of CAD. Metformin, an anti-diabetic drug, has been shown in pre-clinical and clinical studies, to lower the cardiovascular events in the DM patients. Growing evidence suggests that metformin has a protective effect on coronary artery beyond its hypoglycemic effects. Given its global availability, route of administration and cost, metformin provides an alternate/additional therapeutic option for primary and secondary prevention of CAD in DM and non-diabetics alike. Future prospective cohort-based studies and randomized clinical trials are needed to identify 'at-risk' population who may potentially benefit from metformin.

The endothelial cell-specific microRNA (miRNA), miR-126, is considered a master regulator of physiological angiogenesis. Transplanted mesenchymal stem cells (MSCs) release soluble factors contributing to neoangiogenesis and cardiac repair. Therefore, we hypothesized that the over-expression of miR-126 may prolong MSC survival and enhance the cell secretome, thereby improving post-infarction angiogenesis and cardiac function. In this study, MSCs harvested from male C57BL/6 mouse bone marrow were infected in vitro with miR-126 (MSC(miR-126)) by using recombinant lentiviral vectors; the control cells were either non-transfected or transduced with mock vectors (MSC(null)). The results showed an increased secretion of angiogenic factors and a higher resistance against hypoxia in MSC(miR-126) compared with the control cells. The expression of the Notch ligand Delta-like (Dll)-4 in the MSC(miR-126) group was also increased. For in vivo experiments, MSC(miR-126) cultures were intramyocardially injected into the infarct region of the hearts of female C57BL/6 mice (an acute myocardial infarction model) who had undergone ligation of the left anterior descending coronary artery. The survival of MSC(miR-126) cultures, determined by Sry expression, was increased at 7 days after transplantation. MSC(miR-126)-treated animals showed significantly improved cardiac function as assessed by echocardiography 2 weeks later. The expression levels of angiogenic factors and Dll-4 in the infarcted myocardium were further increased by MSC(miR-126) compared with MSCs or MSC(null) cultures. Furthermore, fluorescent microsphere and histological studies revealed that myocardial blood flow and microvessel density were significantly increased in the MSC(miR-126)-transplanted animals. In addition, we found increased immature vessel proliferation following the transplantation of MSC(miR-126) cultures in which the expression of Dll-4 had been knocked down. However, blood vessels with lumen were barely detected, which indicated that Dll-4 plays a key role in tubulogenesis. We conclude that the transplantation of MSCs overexpressing miR-126 can further enhance functional angiogenesis in the ischemic myocardium possibly by the secretion of angiogenic factors and the activation of Dll-4, thus increasing MSC survival. Therefore, MSCs modified with miR-126 may represent a novel and efficient therapeutic approach for ischemic angiogenesis and the improvement of cardiac function.

The specific mechanism of pulmonary arterial hypertension (PAH) remains elusive. The present study aimed to explore the underlying mechanism of PAH through the identity of novel biomarkers for PAH using metabolomics approach. Serum samples from 40 patients with idiopathic PAH (IPAH), 20 patients with congenital heart disease‐associated PAH (CHD‐PAH) and 20 healthy controls were collected and analysed by ultra‐high‐performance liquid chromatography coupled with high‐resolution mass spectrometry (UPLC‐HRMS). Orthogonal partial least square‐discriminate analysis (OPLS‐DA) was applied to screen potential biomarkers. These results were validated in monocrotaline (MCT)‐induced PAH rat model. The OPLS‐DA model was successful in screening distinct metabolite signatures which distinguished IPAH and CHD‐PAH patients from healthy controls, respectively (26 and 15 metabolites). Unbiased analysis from OPLS‐DA identified 31 metabolites from PAH patients which were differentially regulated compared to the healthy controls. Our analysis showed dysregulation of the different metabolic pathways, including lipid metabolism, glucose metabolism, amino acid metabolism and phospholipid metabolism pathways in PAH patients compared to their healthy counterpart. Among these metabolites from dysregulated metabolic pathways, a panel of metabolites from lipid metabolism and fatty acid oxidation (lysophosphatidylcholine, phosphatidylcholine, perillic acid, palmitoleic acid, N‐acetylcholine‐d‐sphingomyelin, oleic acid, palmitic acid and 2‐Octenoylcarnitine metabolites) were found to have a close association with PAH. The results from the analysis of both real‐time quantitative PCR and Western blot showed that expression of LDHA, CD36, FASN, PDK1 GLUT1 and CPT‐1 in right heart/lung were significantly up‐regulated in MCT group than the control group.

BACKGROUND: Previous studies have found that predicted fat mass and lean body mass may act differently on adverse events. However, the cardiovascular prognostic value of lean body mass and fat mass in patients with type 2 diabetes mellitus (T2DM) has not yet been investigated. We sought to investigate the relation between predicted lean body mass or fat mass and the risk of cardiovascular disease in patients with T2DM. METHODS: We conducted a post hoc analysis of data from the Action to Control Cardiovascular Risk in Diabetes

The endothelial cell (EC)-specific miRNA, miR-126, is known to promote angiogenesis in response to angiogenic factors by repressing negative regulators of signal transduction pathways; however, whether miR-126 might regulate the differentiation of stem cells toward endothelial lineage remains unknown. To answer this question, in this study mesenchymal stem cells (MSCs) harvested from C57BL/6 mouse bone marrow were transfected with miR-126 (MSCmiR-126) using recombinant lentiviral vectors. Results showed the para-secretion and the expression levels of phosphorylated PI3K p85, Akt, p38, ERK1 protein in the MSCmiR-126 group were dramatically increased when compared with the control group. With half culture medium refreshed every 3 days, a small number of 6-day-cultured MSCmiR-126 differentiated into endothelial-like cells and most of 9-day-cultured MSCmiR-126 formed a cobblestone-like structure. These differentiated cells evidently expressed EC-specific makers and possessed mature ECs function, while inhibition of paracrine factors suppressed the MSC-EC differentiation. Strikingly, the increased secretion of MSCmiR-126 and their endothelial-differentiated potential were deprived by using a PI3K or MEK chemical inhibitor. Our results suggest that overexpression of miR-126 agumenting the endothelial differentiation of MSCs might in part be attributable to the activation of PI3K/Akt and MAPK/ERK pathways and an increased release of paracrine factors.

Background: The aim of this research was to study whether transplantation of mesenchymal stem cells (MSCs) overexpressing microRNA-1 into mouse infarcted myocardium can enhance cardiac myocyte differentiation and improve cardiac function efficiently. Methods: Eight-week-old female C57BL/6 mice underwent ligation of the left coronary artery to produce models of myocardial infarction. The ligated animals were randomly divided into 4 groups (20 in each). One week later, they were intramyocardially injected at the heart infarcted zone with microRNA-1-transduced MSCs (MSC^miR-1 group), mock-vector-transduced MSCs (MSC^null group), MSCs (MSC group) or medium (PBS group). At 4 weeks post-transplantation, transthoracic echocardiographic assessment, histological evaluation and Western blot were performed. Results: The transplanted MSCs were able to differentiate into cardiomyocytes in the infarcted zone. Cardiac function in the MSC, MSC^null and MSC^miR-1 groups was significantly improved compared to the PBS group (p < 0.01 or p < 0.001). However, treatment of MSCs expressing microRNA-1 was more effective for cardiac repair and improved cardiac function more efficiently by enhancing cell survival and cardiac myocyte differentiation compared to the MSC group or the MSC^null groups (p < 0.05 or p < 0.01, respectively). Conclusions: Transplantation of microRNA-1-transfected MSCs was more conducive to repair of infarct injury and improved heart function by enhancing transplanted cells survival and cardiomyogenic differentiation.

Statins are widely used to reduce cardiovascular risk. Unfortunately, some patients still experience cardiovascular events though prescribed with high-intensity statins. Metformin, an anti-diabetic drug, was reported to possess anti-atherosclerotic effects. Therefore, the experiments were designed to evaluate whether combined use of metformin and atorvastatin can achieve additional benefits. In rabbits fed a high-cholesterol diet, we evaluated the effects of the combination therapy on atherosclerotic plaques, lipid profiles, blood glucose levels, liver and kidney functions. Effects of combination therapy on cholesterol efflux and the expression of related transporters were studied in vitro. Our results showed that the combination therapy induced a more significant decrease in atherosclerotic lesion area than atorvastatin without additional lipid-lowering effect. The combination therapy significantly increased the percentage of large high-density lipoprotein subfraction. The intravenous glucose tolerance test showed that atorvastatin-treated rabbits had an increased area under the curve for time-dependent glucose levels after a bolus injection of glucose, which was completely reversed by metformin treatment. In cultured macrophages, co-treatment with metformin and atorvastatin promoted cholesterol efflux and up-regulated expression of ATP-binding cassette transporters A1 and G1. Taken together, our results suggest that atorvastatin/metformin combination therapy may achieve additional anti-atherosclerotic benefits likely through increasing cholesterol efflux in macrophages.