Racial differences in the responses to shear stress in human umbilical vein endothelial cells

Abstract

Background:African American ethnicity is an independent risk factor for exaggerated oxidative stress, which is related to inflammation, hypertension, and cardiovascular disease. Recently, we reported that in vitro oxidative stress and inflammation levels differ between African American and Caucasian human umbilical vein endothelial cells (HUVECs), African American HUVECs having higher levels of both. However, it remains to be shown whether the cells would respond differently to external stimuli.Methods:We used a cone and plate viscometer to apply laminar shear stress (LSS) as an aerobic exercise mimetic to compare the responses by race. HUVECs were exposed to static conditions (no LSS), low LSS (5 dyne/cm2), and moderate LSS (20 dyne/cm2).Results:It was found that African American HUVECs had higher levels of oxidative stress under static conditions, and when LSS was applied protein expression levels (NADPH oxidase NOX2, NOX4 and p47phox subunits, eNOS, SOD2, and catalase) and biomarkers (NO, SOD, and total antioxidant capacity) were modulated to similar levels between race.Conclusion:African American HUVECs may be more responsive to LSS stimulus indicating that aerobic exercise prescriptions may be valuable for this population since the potential exists for large in vivo improvements in oxidative stress levels along the endothelial layer in response to increased shear flow.

Are they in or out? The Elusive Interaction between Qtracker ® 800 Vascular Labels and Brain Endothelial Cells

“…Our data agree with previously reported donor-dependent variability of HUVECs exposed to laminar shear stress [59], and might have implications for the use of near-infrared-emitting quantum dots in clinical vascular imaging applications.…”

Shear stress-induced mitochondrial biogenesis decreases the release of microparticles from endothelial cells

“…NO levels were indirectly measured by determining NO end-products, nitrate and nitrite, using an Enzo Life Sciences/ Assay Designs assay kit as described previously (18). Absorbance was read at 540 nm.…”

Cardiorespiratory function associated with dietary nitrate supplementation

“…Some of the essential hypertension in African Americans has been explained by endothelial cell dysfunction (Kalinowski et al 2004), and it has been hypothesized that an insufficiency of NOS activity is associated with a gene variant that reduces the normal production of NO (Martinez Cantarin et al 2010). A study supporting this hypothesis found that umbilical arteries from African Americans exhibited greater oxidative stress and inflammation during exposures to increased shear forces than did those from Caucasian Americans (Feairheller et al 2011 a , 2011 b ). One approach to overcoming NO deficiency is dietary supplementation of nitrate and increasing the bioavailability of NO by using foods such as beetroot juice (Miller et al 2012).…”