Charcoal-stripped serum impairs growth and sprouting of male and female human umbilical vein endothelial cells (HUVECs) regardless of estrogens

Loss of a normal endothelial function crucially contributes to the development and clinical expression of atherosclerosis and cardiovascular disease (CVD). Despite substantial sex/gender differences have been described in the occurrence of CVD, very little is known about innate sex properties of male and female endothelial cells (ECs). To characterize putative sex-dependent differences, we compared in vitro properties of male and female human umbilical vein ECs (HUVECs) showing that female HUVECs express an higher amount of eNOS mRNA and protein, and possess greater migratory capabilities in comparison to male cells. Male and female HUVECs did not show however any significant difference in metabolic activity. Since a crucial issue in the sex-related incidence of CVD concerns estrogens, we compared male and female HUVECs grown in standard medium or in a nominally estrogen-free medium containing charcoal-stripped FBS. We found that lack of hormones induced in both sexes: i) a decrease in cell number, and as a consequence in metabolic activity (evaluated by MTT and ATP); ii) an impaired in vitro angiogenesis. All the effects were not reverted by 17-beta-estradiol (E2). These results suggest that estrogens did not represent a critical factor for the maintenance of EC behavior regardless of cell sex. Experiments are ongoing to identify substance(s) responsible for EC rescue from charcoal-stripped FBS-induced impairment in growth and angiogenesis.