MicroRNA-122 aggravates angiotensin II-mediated apoptosis and autophagy imbalance in rat aortic adventitial fibroblasts via the modulation of SIRT6-elabela-ACE2 signaling.

Abnormal aortic adventitial fibroblasts (AFs) play essential roles in the development of vascular remodeling and disorders. Previous studies revealed that microRNA-122 (miR-122) levels were elevated in the aortic adventitia of hypertensive rats with vascular injury. Here, we aim to evaluate the biological effects and underlying mechanisms of miR-122 in rat AFs. Exposure to angiotensin II (ATII) in rat AFs resulted in decreased levels of sirtuin 6 (SIRT6), elabela (ELA), and angiotensin-converting enzyme 2 (ACE2). Additionally, stimulation with ATII contributed to a decline in autophagic flux and obvious increases in cellular migration, oxidative stress, and apoptosis, which were exacerbated by the transfection of miR-122-5p mimic but were rescued by miR-122-5p inhibitor, exogenous replenishment of ELA, and recombinant adeno-associated virus expressing SIRT6 (rAAV-SIRT6), respectively. Moreover, stimulation with miR-122-5p mimic led to a marked reduction in the levels of SIRT6 and ELA in rat AFs, which were elevated by stimulation with rAAV-SIRT6. Furthermore, miR-122-5p inhibitor-mediated pro-autophagic, anti-oxidant and anti-apoptotic effects in rat AFs were partially suppressed by 3-methyladenine, SIRT6 small interfering RNA (siRNA) and ELA siRNA, which were linked with the downregulation in the protein levels of LC3-II, beclin-1, and ACE2 and the upregulation of p62 expression and bax/bcl-2 ratio. Our findings indicated that miR-122-5p inhibition prevented ATII-mediated loss of autophagy, and the promotion of apoptosis and oxidative stress via activating the SIRT6-ELA-ACE2 signaling. MiR-122-5p may be a novel predictive biomarker of adventitial injury, and targeting the SIRT6-ELA-ACE2 signaling may have the potential therapeutic importance of controlling vascular remodeling and disorders.

Progress in Therapies for Myocardial Ischemia Reperfusion Injury.

BACKGROUND: Experimental studies of acute myocardial infarction have revealed that up to half of the final infarct size may be due to reperfusion injury rather than the initial ischemic incident. Research over the past three decades has deepened our understanding of the molecular mechanisms underlying ischemic reperfusion injury and several therapeutic strategies to decrease the incidence and severity of reperfusion injury have been explored. OBJECTIVE: To discuss the promising therapies and future perspectives on methods to attenuate myocardial reperfusion injury. RESULTS: Existing therapies that address reperfusion can be divided into two major groups comprising nonpharmacological and pharmacological interventions. Myriad pharmacological and nonpharmacological approaches to reduce lethal reperfusion injury have been employed. Although many initial clinical studies were negative, more recent proof-of-concept clinical trials are promising. To date, the most encouraging results are with ischemic postconditioning, remote ischemic preconditioning, ANP, adenosine, cyclosporine and exenatide. CONCLUSION: Studies demonstrate that nonpharmacological and pharmacological conditioning can be used together as part of a multifaceted approach to improve clinical outcomes in patients with ischemic heart disease.

The ideal cardiovascular health metrics associated inversely with mortality from all causes and from cardiovascular diseases among adults in a Northern Chinese industrial city.

BACKGROUND AND AIMS: The American Heart Association has recently established seven ideal cardiovascular health metrics for cardiovascular health promotion and disease reduction (i.e., non-smoking, normal body mass index, physically active, healthy diet, and normal levels of cholesterol, blood pressure and fasting blood glucose). The present study seeks to evaluate how well these metrics predict mortality from all causes and cardiovascular diseases in adult Chinese living in a northern industrial city. METHODS AND RESULTS: Data of 95,429 adults who participated in the Kailuan cohort study from June 2006 to October 2007 was analyzed. All participants underwent questionnaire assessment, clinical examination, laboratory assessments and were followed up biannually. During a median follow-up of 4.02 years, 1,843 deaths occurred, with 597 deaths resulting from cardiovascular diseases. Lower mortality rates from all causes and cardiovascular diseases were observed among the subjects who met a higher number of the ideal health metrics. Compared to the participants who met none or one ideal health metric, those meeting ≥5 ideal health metrics had a lower risk of all-cause mortality by 30% (adjusted hazard ratio, 0.70; 95% confidence interval, 0.56-0.88) and a lower risk of mortality from cardiovascular diseases by 39% (adjusted hazard ratio, 0.61; 95% confidence interval, 0.41-0.89) . Four metrics (smoking status, physical activity, blood pressure and fasting blood glucose) were significantly associated with all-cause mortality. Three metrics (physical activity, blood pressure and fasting blood glucose) were significantly associated with mortality from cardiovascular diseases. CONCLUSION: The number of ideal health metrics is negatively associated with mortality rates from all causes and cardiovascular diseases among adults in a Northern Chinese industrial city. The data supports the AHA recommendation of ideal health metrics for adults from Northern China.

[Effects of reperfusion arrhythmia on myocardial apoptosis and left ventricular remodeling in patients with acute myocardial infarction].

OBJECTIVE: To observe plasma soluble Fas/APO-1 concentration in patients with reperfusion arrhythmia immediately after coronary reperfusion in patients with acute myocardial infarction (AMI) and to investigate the impact of reperfusion arrhythmia on left ventricular (LV) remodeling in AMI patients. To observe the relationship between cardiomyocytes apoptosis with reperfusion arrhythmia in patients with acute myocardial infarction (AMI), and investigate the impact of reperfusion arrhythmia on left ventricular (LV) remodeling in patients with AMI. METHODS: One hundred and fifty-six patients with AMI who received reperfusion therapy were selected as subjects. Fifty-eight patients underwent reperfusion arrhythmia within 24 hour after coronary reperfusion treatment (RA group). Ninety-eight patients did not occurred reperfusion arrhythmia (Non-RA group). Strepavidin-biotin ELISA was used to determine the soluble Fas/APO-1 plasma concentration at baseline, 7 day (d) and 2 - 4 week (W). All patients were followed up with scheduled evaluations of LV function and morphology with left ventriculography for 1 year. RESULTS: 1. It was later that the coronary reperfusion occurred in patients of RA group than that of Non-RA group, and the left anterior descending was more frequent infarct related artery (60.3%) than of Non-RA group (36.9%, P < 0.05). 2. The Fas/APO-1 levels in patients of RA group higher than those of Non-RA group at baseline [(13.82 +/- 4.36) microg/L vs (8.19 +/- 3.56) microg/L, P < 0.01]. 3. The highest level of Fas/APO-1 was on 7 d after AMI and the plasma levels of Fas/APO-1 in 2 - 4 W were slightly lower than those in 7 d in the two groups [RA group: (10.91 +/- 3.65) microg/L vs (14.26 +/- 4.98) microg/L, P < 0.05; Non-RA group: (4.69 +/- 1.87) microg/L vs (12.19 +/- 3.25) microg/L, P < 0.01]. However, the Fas/APO-1 level of 2 - 4 W in RA group was slightly higher than the level in Non-RA group [(10.91 +/- 3.65) microg/L vs (4.69 +/- 1.87) microg/L, P < 0.01]. 4. There was on difference between two groups in left ventricular ejection fraction (LVEF) and the left ventricular end-diastolic dimension (LVEDD) one week after AMI [LVEF: (47.7 +/- 9.6)% vs (49.2 +/- 8.9)%, P > 0.05; LVEDD: (59.7 +/- 10.3) mm vs (57.4 +/- 12.4) mm, P > 0.05]. 5. In the Non-RA group, the LVEF significantly increased from 1 W phase to the 1-year phase [from (49.2 +/- 8.9)% to (59.5 +/- 9.2)%, P < 0.05], but unchanged in the 58 patients without reperfusion arrhythmia [from (47.7 +/- 9.6)% to (49.9 +/- 10.1)%, P > 0.05]. The LVEF of Non-RA group was slightly higher than that of RA group at 1 year [(59.5 +/- 9.2)% vs (49.9 +/- 10.1)%, P < 0.05]. The LVEDD had no significant difference between two groups, but there was downtrend in the Non-RA group at 1 year after AMI. CONCLUSION: Reperfusion arrhythmia was related with cardiomyocytes apoptosis in patients with AMI, and might influence left ventricular function and promote LV remodeling.