Effect of Interleukin-10 and Laminar Shear Stress on Endothelial Nitric Oxide Synthase and Nitric Oxide in African American Human Umbilical Vein Endothelial Cells

Abstract

<p><strong>Background: </strong>African Americans have a pre­disposition to heightened systemic inflamma­tion and a high prevalence of hypertension.</p><p><strong>Objective: </strong>The purpose of this study was to evaluate the influence of interleukin-10 (IL- 10) and laminar shear stress (LSS) on African American endothelial cells by measuring to­tal endothelial nitric oxide synthase (eNOS) protein expression and its phosphorylated form (p-eNOS) at Serine 1177, and nitric oxide (NO) levels, in response to IL-10 incubation and high physiological levels of LSS, used as an <em>in vitro </em>mimetic for aerobic exercise training (AEXT).</p><p><strong>Design: </strong>Human umbilical vein endothelial cells (HUVEC) from an African American donor were cultured. The experimental conditions included <em>Static</em>, <em>Static with IL-10 Incubation, LSS at 20 dynes/cm</em><em>2</em><em>, and LSS at 20 dynes/cm</em><em>2 </em><em>with IL-10 Incubation</em>. West­ern blotting was used to measure eNOS and p-eNOS protein expression in the cells. A modified Griess assay was used to measure NO metabolites in the cell culture media.</p><p><strong>Results: </strong>There were significant increases in p-eNOS, eNOS, and NO in the <em>LSS at 20 dynes/cm</em><em>2 </em>and <em>LSS at 20 dynes/cm</em><em>2 </em><em>with IL-10 Incubation </em>experimental conditions when compared to the <em>Static </em>experimental condition. There were no other statistically significant differences demonstrating that IL- 10 did not have an additive effect on eNOS activity in our study.</p><p><strong>Conclusion: </strong>The significant increases in p-eNOS, eNOS, and NO as a result of LSS in African American HUVECs suggest that AEXT may be a viable, nonpharmacologic method to improve vascular inflamma­tion status and vasodilation, and thereby contribute to hypertension reduction in the African American population. <em>Ethn Dis. </em>2015;25(4):413-418; doi:10.18865/ ed.25.4.413</p>