Exosomes secreted from osteocalcin-overexpressing endothelial progenitor cells promote endothelial cell angiogenesis.

Exosome secretion is an important paracrine way of endothelial progenitor cells (EPCs) to modulate resident endothelial cells. The osteocalcin (OCN)-expressing EPCs have been found to be increased in cardiovascular disease patients and are considered to be involved in the process of coronary atherosclerosis. Since OCN has been proven to prevent endothelial dysfunction, this study aimed to evaluate the effect of exosomes derived from OCN-overexpressed EPCs on endothelial cells. Exosomes derived from EPCs (Exos) and OCN-overexpressed EPCs (OCN-Exos) were isolated and incubated with rat aorta endothelial cells (RAOECs) with or without the inhibition of OCN receptor G protein-coupled receptor family C group 6 member A (GPRC6A). The effects of exosomes on the proliferation activity of endothelial cells were evaluated by CCK-8 assay, and the migration of endothelial cells was detected by wound healing assay. A tube formation assay was used to test the influence of exosomes on the angiogenesis performance of endothelial cells. Here, we presented that OCN was packed into Exos and was able to be transferred to the RAOECs via exosome incorporation, which was increased in OCN-Exos groups. Compared with Exos, OCN-Exos had better efficiency in promoting RAOEC proliferation and migration and tube formation. The promoting effects were impeded after the inhibition of GPRC6A expression in RAOECs. These data suggest that exosomes from OCN-overexpressed EPCs have a beneficial regulating effect on endothelial cells, which involved enhanced OCN-GPRC6A signaling.

Prognostic significance of the hemoglobin A1c level in non-diabetic patients undergoing percutaneous coronary intervention: a meta-analysis.

BACKGROUND: The predictive value of hemoglobin A1c (HbA1c) levels in non-diabetic patients with myocardial infarction undergoing percutaneous coronary intervention (PCI) is still controversial. This study aimed to evaluate whether HbA1c levels were independently associated with adverse clinical outcomes in non-diabetic patients with coronary artery disease (CAD) who had undergone PCI by performing a meta-analysis of cohort studies. METHODS: This meta-analysis included non-diabetic patients with CAD who had undergone PCI. A systematic search for publications listed in the PubMed, Embase, and Cochrane Library databases from commencement to December 2018 was conducted. Studies evaluating the adverse clinical outcomes according to abnormal HbA1c levels in non-diabetic patients diagnosed with CAD who had undergone PCI were eligible. The primary outcomes were long-term all-cause deaths and long-term major adverse cardiac events, and the secondary outcome was short-term all-cause deaths. The meta-analysis was conducted with RevMan 5.3 and Stata software 14.0. Odds ratios (ORs) were pooled using a random or fixed-effects model, depending on the heterogeneity of the included studies. Sub-group analysis or sensitivity analysis was conducted to explore potential sources of heterogeneity, when necessary. RESULTS: Six prospective cohort studies involving 10,721 patients met the inclusion criteria. From the pooled analysis, abnormal HbA1c levels were associated with increased risk for long-term all-cause death (OR 1.39, 95% confidence interval [CI] 1.16-1.68, P = 0.001, I = 45%). Sub-group analysis suggested that abnormal HbA1c levels between 6.0% and 6.5% predicted higher long-term major adverse cardiac event (including all-cause deaths, non-fatal myocardial infarction, target lesion revascularization, target vessel revascularization, recurrent acute myocardial infarction, heart failure requiring hospitalization, and stent thrombosis) risk (OR 2.05, 95% CI 1.46-2.87, P < 0.001, I = 0). Contrarily, elevated HbA1c levels were not associated with increased risk of short-term all-cause death (OR 1.16, 95% CI 0.88-1.54, P = 0.300, I = 0). CONCLUSIONS: An abnormal HbA1c level is an independent risk factor for long-term adverse clinical events in non-diabetic patients with CAD after PCI. Strict control of HbA1c levels may improve patient survival. Further studies in different countries and prospective cohort studies with a large sample size are required to verify the association.