Omega-3 and Omega-6 polyunsaturated fatty acids stimulate vascular differentiation of mouse embryonic stem cells.

Polyunsaturated fatty acids (PUFAs) and their metabolites may influence cell fate regulation. Herein, we investigated the effects of linoleic acid (LA) as omega-6 PUFA, eicosapentaenoic acid (EPA) as omega-3 PUFA and palmitic acid (PA) on vasculogenesis of embryonic stem (ES) cells. LA and EPA increased vascular structure formation and protein expression of the endothelial-specific markers fetal liver kinase-1, CD31 as well as VE-cadherin, whereas PA was without effect. LA and EPA increased reactive oxygen species (ROS) and nitric oxide (NO), activated endothelial NO synthase (eNOS) and raised intracellular calcium. The calcium response was inhibited by the intracellular calcium chelator BAPTA, sulfo-N-succinimidyl oleate which is an antagonist of CD36, the scavenger receptor for fatty acid uptake as well as by a CD36 blocking antibody. Prevention of ROS generation by radical scavengers or the NADPH oxidase inhibitor VAS2870 and inhibition of eNOS by L-NAME blunted vasculogenesis. PUFAs stimulated AMP activated protein kinase-alpha (AMPK-alpha) as well as peroxisome proliferator-activated receptor-alpha (PPAR-alpha). AMPK activation was abolished by calcium chelation as well as inhibition of ROS and NO generation. Moreover, PUFA-induced vasculogenesis was blunted by the PPAR-alpha inhibitor GW6471. In conclusion, omega-3 and omega-6 PUFAs stimulate vascular differentiation of ES cells via mechanisms involving calcium, ROS and NO, which regulate function of the energy sensors AMPK and PPAR-alpha and determine the metabolic signature of vascular cell differentiation.