HUVECs with endogenous or overexpressed GPR4 treated with pH 8.4 (control) or pH 6.4 for 5 h

Acidic tissue microenvironment is commonly found in a variety of pathophysiological conditions. GPR4 is a proton-sensing G protein-coupled receptor that is fully activated by acidic extracellular pH but has lesser activity at the physiological pH 7.4 and minimal activity at more alkaline pH. To determine the effects of GPR4 activation by acidosis on vascular endothelial cells, we examined the global gene expression of the acidosis response in primary human umbilical vein endothelial cells (HUVEC) with varying level of GPR4. HUVEC with endogenous or overexpressed GPR4 level (designated as HUVEC/Vector & HUVEC/GPR4 cells). Two treatment conditions: pH 6.4 vs. pH 8.4 for 5 h. Biological replicates: 4 HUVEC/Vector replicates (pH6.4 vs pH 8.4), and 4 HUVEC/GPR4 replicates (pH6.4 vs pH 8.4).