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

Area of Science:

• Cardiovascular Disease Research
• Endothelial Biology
• Epigenetics and microRNAs

Background:

• African Americans (AA) have a higher risk of cardiovascular disease (CVD).
• Aberrant vascular reactivity and epigenetic factors like microRNAs (miRs) may contribute to this disparity.
• Endothelial cells play a crucial role in vascular health and inflammation.

Purpose of the Study:

• To investigate racial differences in endothelial inflammation and microRNA profiles following acute inflammatory stimulus.
• To compare the response of endothelial cells from African Americans (AA) and Caucasian Americans (CA) to influenza vaccine.
• To assess in vivo endothelial function and circulating miRs after vaccination in different racial groups.

Main Methods:

• Cultured human umbilical vein endothelial cells (HUVECs) from AA and CA donors were exposed to influenza vaccine.
• Measured inflammatory markers, endothelial nitric oxide synthase (eNOS) mRNA, and miR expression/release in HUVECs.
• Assessed endothelial function (flow-mediated dilation - FMD), circulating IL-6, and circulating miRs in AA and CA individuals post-vaccination.

Main Results:

• Influenza vaccine increased IL-6 release and ICAM-1 mRNA, and reduced eNOS mRNA in AA HUVECs, but not CA HUVECs.
• Specific intracellular miRs (miR-221-3p, miR-222-3p) increased in CA HUVECs, while miR-150-5p release decreased in AA HUVECs.
• In vivo, vaccination caused similar systemic IL-6 increases in both groups, but did not affect FMD or circulating miRs.

Conclusions:

• Endothelial cells from African Americans exhibit greater susceptibility to acute inflammation induced by influenza vaccine.
• Race-specific changes in intracellular and secreted miRs occur in response to acute inflammation.
• These endothelial cell-specific responses may underlie exaggerated inflammatory reactions and contribute to CVD disparities in African Americans.