Moderate intake of red wine improves ischemia-induced neovascularization in diabetic mice-Roles of endothelial progenitor cells and nitric oxide

Objective: Circulating endothelial progenitor cells (EPCs) play a significant role in postnatal neovascularization. Patients with diabetes have attenuated EPC functions and impaired angiogenic response after tissue ischemia. We investigated whether moderate red wine consumption can enhance blood flow recovery in response to tissue ischemia by enhancement of EPC functions in diabetic mice. Methods and results: Starting at 4 weeks after diabetes onset, red wine (4ml/kg/day) or ethanol were administered to streptozotocin (STZ)-induced (type 1) diabetic mice and KKAy-Ta (type 2) mice. Unilateral hind limb ischemia surgery was conducted after 2 weeks of red wine or ethanol ingestion. Type 1 and type 2 diabetic mice given red wine, but not ethanol, had significantly increased collateral flow about 30% and augmented capillary density in ischemic tissues. These beneficial effects were markedly abolished by an eNOS inhibitor (L-NAME). Flow cytometry analysis showed impaired EPC-like cells (Sca-1⁺/Flk-1⁺) mobilization after ischemia surgery in diabetic mice, but augmented mobilization in red wine group (baseline vs. 2 days after operation: 0.88±0.06% vs. 1.73±0.29%, p=0.010). C-kit positive bone marrow cells isolated from diabetic mice given red wine had enhanced adhesion and migration compared to mice given vehicle. By in-vitro studies, incubation with red wine in high-glucose medium significantly reduced H₂O₂ production, and improved high glucose-suppressed EPC functions by nitric oxide-related mechanisms. Conclusions: Our findings demonstrate that red wine consumption enhances blood flow recovery after tissue ischemia in diabetic mice. These effects may partly derive from enhanced EPC functions by upregulation of eNOS activity.