(Pro)renin receptor over‐expression induces angiotensin II‐independent NADPH oxidase activation through PI3K ‐ ERK signaling in Neuronal cells

Abstract

We previously showed that (pro)renin receptor (PRR) mediates angiotensin II‐independent NADPH oxidase (NOX) activation and oxidative stress in neuronal cells. To investigate the signaling cascade of these events, Neuro‐2A cells were infected with adeno‐associated virus coding for human PRR and control virus. Cells were then treated with phosphoinositide 3‐kinase (PI3K,) inhibitor (wortmannin, 2uM) or extracellular signal‐regulated kinases 1/2(ERK1/2) inhibitor (U0126, 20uM). NOX activity, NOX2 and NOX4 expression levels were determined. The PI3K and ERK1/2 inhibitor decreased NOX2 (wortmannin: 2.685±0.11 vs. 6.346±0.532, P<0.05; U0126:0.373±0.03 vs. 6.346±0.53, P<0.05) and NOX4 (wortmannin:1.803±0.04 vs. 2.658±0.13, P<0.05; U0126:1.391±0.01 vs. 2.658±0.13, P<0.05) mRNA levels (Relative fold change) compare to vehicle following PRR over‐expression. Furthermore, PI3K (0.965±0.02 vs. 1.280±0.03, P<0.05) or ERK1/2 (0.923±0.03 vs. 1.280±0.03, P<0.05) inhibition significantly reduced NOX activity (Relative luminescence units) compared to vehicle following PRR over‐expression. These data suggested that PRR over‐expression induces oxidative stress in neuronal cells through activation of PI3K ‐ERK1/2 signaling cascade, and thus up‐regulation of NOX2 and NOX4 levels, indicating a new pathway for oxidative stress in the central nervous system.(NIH1P30HL101285, AHA11SDG73600050)