Race-specific changes in endothelial inflammation and microRNA in response to an acute inflammatory stimulus

Both aberrant vascular reactivity to acute cardiovascular stress and epigenetic mechanisms such as microRNA (miR) may underlie the increased propensity for African Americans (AA) to develop cardiovascular disease. This study assessed racial differences in acute induced endothelial inflammation and related miRs. Cultured human umbilical vein endothelial cells (HUVECs) derived from AA and Caucasian Americans (CA) were exposed to the influenza vaccine to determine changes in inflammatory markers, endothelial nitric oxide synthase (eNOS), and miR expression/release. Endothelial function (flow-mediated dilation [FMD]), circulating IL-6, and circulating miR were also measured in young, healthy AA and CA individuals before and after receiving the influenza vaccine. There were no significant racial differences in any parameters at baseline. The vaccine induced increases in IL-6 release (24%, P=0.02) and ICAM-1 mRNA (40%, P=0.03), as well as reduced eNOS mRNA (24%, P=0.04) in AA HUVECs, but not in CA HUVECs (all P>0.05). Intracellular levels of anti-inflammatory miR-221-3p and miR-222-3p increased specifically in CA HUVECs (72% and 53%, p=0.04 and p=0.06), while others did not change in either race. HUVEC secretion of several miRs decreased in both races, while the release of anti-inflammatory miR-150-5p was decreased only by AA cells (-30%, P=0.03). In individuals of both races, circulating IL-6 increased ~two-fold 24 hours after vaccination (both P