ABSTRACT
Alcohol abuse has a negative impact on human health; however, epidemiological studies show that moderate consumption of ethanol (EtOH) reduces the risk of coronary heart disease, sudden cardiac death, and ischemic stroke. The mechanisms for these reductions in cardiovascular disease are not well established. Using cultured coronary artery vascular smooth muscle cells, we found that moderate levels of EtOH (10 and 20 mM) caused dose-related increases in both vascular endothelial growth factor (VEGF) mRNA (Northern blot) expression (1.9- and 2.6-fold) and VEGF protein (ELISA) expression (19 and 68%) compared with control (P < 0.05). EtOH at 0.25 g. kg(-1). day(-1) (7 days) increased VEGF mRNA expression by 1.48-fold over control, and increased vessel length density from 3.9 +/- 0.7 (control) to 6.0 +/- 0.3 mm/mm(2) (P < 0.05) in chick chorioallantoic membrane (CAM). We conclude that moderate levels of ethanol can induce VEGF expression and stimulate angiogenesis in chick CAM. Therefore, the results provide a theoretical basis for speculating that the cardiovascular-protective effects of moderate alcohol consumption may be partly mediated through VEGF-induced angiogenesis.
Subject(s)
Central Nervous System Depressants/pharmacology , Endothelial Growth Factors/genetics , Ethanol/pharmacology , Lymphokines/genetics , Muscle, Smooth, Vascular/physiology , Neovascularization, Physiologic/drug effects , Transcription Factors , Animals , Cell Division/drug effects , Cells, Cultured , Chick Embryo , Chorion/blood supply , Chorion/physiology , Coronary Vessels/cytology , Coronary Vessels/drug effects , Coronary Vessels/physiology , DNA-Binding Proteins/genetics , Dogs , Dose-Response Relationship, Drug , Endothelium, Vascular/cytology , Endothelium, Vascular/drug effects , Gene Expression/drug effects , Hypoxia-Inducible Factor 1 , Hypoxia-Inducible Factor 1, alpha Subunit , Male , Muscle, Smooth, Vascular/cytology , Muscle, Smooth, Vascular/drug effects , Nuclear Proteins/genetics , RNA, Messenger/analysis , Umbilical Veins/cytology , Vascular Endothelial Growth Factor A , Vascular Endothelial Growth FactorsABSTRACT
We tested whether increased endogenous adenosine produced by the adenosine kinase inhibitor GP-515 (Metabasis Therapeutics) can induce vascular endothelial growth factor (VEGF) expression in cultured rat myocardial myoblasts (RMMs). RMMs were cultured for 18 h in the absence (control) and presence of GP-515, adenosine (Ado), adenosine deaminase (ADA), or GP-515 + ADA. GP-515 (0.2-200 microM) caused a dose-related increase in VEGF protein expression (1.99-2.84 ng/mg total cell protein); control VEGF was 1.84 +/- 0.05 ng/mg. GP-515 at 2 and 20 microM also increased VEGF mRNA by 1.67- and 1. 82-fold, respectively. ADA (10 U/ml) decreased baseline VEGF protein levels by 60% and completely blocked GP-515 induction of VEGF. Ado (20 microM) and GP-515 (20 microM) caused a 59 and 39% increase in VEGF protein expression and a 98 and 33% increase in human umbilical vein endothelial cell proliferation, respectively, after 24 h of exposure. GP-515 (20 microM) had no effect on VEGF protein expression during severe hypoxia (1% O(2)) but increased VEGF by an additional 27% during mild hypoxia (10% O(2)). These results indicate that raising endogenous levels of Ado through inhibition of adenosine kinase can increase the expression of VEGF and stimulate endothelial cell proliferation during normoxic and hypoxic conditions.
