Angiotensin II memory contributes to the development of hypertension and vascular injury via activation of NADPH oxidase

Aims: Activation of the rennin-angiotensin systemplays a critical role in the development of hypertension and its complication. Our previous study has demonstrated that a cellular memory is involved in angiotensin II (Ang II)-induced cardiac hypertrophy. The aim of this study is to investigate the effect of reversal of high Ang II to normal condition on hypertension and vascular damage. Main methods: Wild-type male mice were randomly divided into five groups. The vascular function, inflammation, oxidative stress and angiogenesis were examined by aortic ring relaxation studies, histological analysis, real-time PCR and Western blot analysis. Key findings: We found that continuous high Ang II infusion for 3 weeks (Ang II 3w) significantly elevated blood pressure, increased aortic wall thickness, collagen deposition, inflammation, oxidative stress, vascular function and activation of p38 MAPK, JNK1/2, STAT3 and NF-kappa B pathways in mouse aorta compared with saline group. High Ang II exposure for 2 weeks followed by saline for 1 week (Ang II 2 + 1w) failed to reverse these alterations. This phenomenon was named metabolic memory (or persistent effect). However, addition of NADPH oxidase inhibitor apocynin during saline infusion (Ang II 2 + 1w + Apo) markedly ameliorated such deleterious effects. Significance: These results showed that we report the first that persistent effect or metabolicmemory of angiotensin II through NADPH oxidase-mediated oxidative stress plays important roles in hypertension and vascular injury. (C) 2016 Elsevier Inc. All rights reserved.