Activation of the CaR-CSE/H2S pathway confers cardioprotection against ischemia-reperfusion injury.

Ischemia-reperfusion (I/R) injury is a multifactorial process triggered when an organ is subjected to transiently reduced blood supply. The result is a cascade of pathological complications and organ damage due to the production of reactive oxygen species following reperfusion. The present study aims to evaluate the role of activated calcium-sensing receptor (CaR)-cystathionine γ-lyase (CSE)/hydrogen sulfide (H2S) pathway in I/R injury. Firstly, an I/R rat model with CSE knockout was constructed. Transthoracic echocardiography, TTC and HE staining were performed to determine the cardiac function of rats following I/R Injury, followed by TUNEL staining observation on apoptosis. Besides, with the attempt to better elucidate how CaR-CSE/H2S affects I/R, in-vitro culture of human coronary artery endothelial cells (HCAECs) was conducted with gadolinium chloride (GdCl3, a CaR agonist), H2O2, siRNA against CSE (siCSE), or W7 (a CaM inhibitor). The interaction between CSE and CaM was subsequently detected. Plasma oxidative stress indexes, H2S and CSE, and apoptosis-related proteins were all analyzed following cell apoptosis. We found that H2S elevation led to the improvement whereas CSE knockdown decreased cardiac function in rats with I/R injury. Moreover, oxidative stress injury in I/R rats with CSE knockout was aggravated, while the increased expression of H2S and CSE in the aortic tissues resulted in alleviated the oxidative stress injury. Moreover, increased H2S and CSE levels were found to inhibit cell apoptotic ability in the aortic tissues after I/R injury, thus attenuating oxidative stress injury, accompanied by inhibited expression of apoptosis-related proteins. In HCAECs following oxidative stress treatment, siCSE and CaM inhibitor were observed to reverse the protection of CaR agonist. Coimmunoprecipitation assay revealed the interaction between CSE and CaM. Taken together, all above-mentioned data provides evidence that activation of the CaR-CSE/H2S pathway may confer a potent protective effect in cardiac I/R injury.

Impact of Timing following Acute Myocardial Infarction on Efficacy and Safety of Bone Marrow Stem Cells Therapy: A Network Meta-Analysis.

Background. The optimal timing for Bone Marrow Stem Cells (BMCs) therapy following acute myocardial infarction (AMI) remains unclear. Aims. To synthesize the evidence from trials using a multiple-treatment comparison method, thereby permitting a broader comparison across multiple timing of BMCs therapy. Methods and Results. Randomized controlled trials in patients with AMI receiving BMCs therapy were identified from PubMed, Ovid LWW, BIOSIS Previews, and the Cochrane Library through January 2015. 2 035 patients of 31 studies included in our analysis were allocated to 5 groups' treatments: 1~3 days, 4~7 days, 8~14 days, 15~30 days, or placebo/control group. The multiple-treatment meta-analysis showed that 4~7 days' group could lead to significantly increased left ventricular ejection fraction (LVEF) as compared with control (mean of MDs and 95% CI: 6 months, 3.05 (0.92~5.25); 12 months, 4.18 (2.30~5.84)). Only 4~7 days led to significant reduction of MACEs compared with control (OR and 95% CI 0.34 (0.13~0.96)) for 12-months follow-up. In simulated comparisons, the 4~7 days' group ranked better than other timing groups for improvement of LVEF or reduction of the incidence of major adverse cardiac events. Conclusions. 4~7 days after AMI might be the optimal timing for cell therapy in terms of efficacy or safety.

Effectiveness and safety of selected bone marrow stem cells on left ventricular function in patients with acute myocardial infarction: a meta-analysis of randomized controlled trials.

BACKGROUND: Concerns regarding the use of selected bone marrow stem cells (BMSCs) in the field of cardiac repair after acute ischemic events have been raised. The current meta-analysis aimed to assess the efficacy and safety of selected BMSC transplantation in patients with acute myocardial infarction (AMI) based on published randomized controlled trials (RCTs). METHODS: A systematic literature search of PubMed, Ovid LWW, BIOSIS Previews, and the Cochrane library from 1990 to 2014 was conducted. Results from RCTs involving subjects with AMI receiving selected BMSC therapy and followed up for at least 6 months were pooled. RESULTS: Eight trials with a total of 262 participants were included. Data were analyzed using a random effects model. Overall, selected BMSC therapy improved left ventricular ejection fraction (LVEF) by 3.17% (95% confidence interval [CI] 0.57-5.76, P=0.02), compared with the controls. There were trends toward reduced left ventricular end-systolic volume (LVESV) and fewer major adverse cardiac events (MACEs). Subgroup analysis revealed a significant difference in LVEF in favor of selected BMSC therapy with bone marrow mesenchymal stem cells (BMMSCs) as the cell type. CONCLUSIONS: Transplantation of selected BMSCs for patients with AMI is safe and induces a significant increase in LVEF with a limited impact on left ventricular remodeling.