Atorvastatin attenuates angiotensin II-induced inflammatory actions in the liver

Abstract

Statins exert beneficial effects in chronically damaged tissues. Angiotensin II (ANG II) participates in liver fibrogenesis by inducing oxidative stress, inflammation, and transforming growth factor-β1 (TGF-β1) expression. We investigate whether atorvastatin modulates ANG II-induced pathogenic effects in the liver. Male Wistar rats were infused with saline or ANG II (100 ng·kg−1·min−1) for 4 wk through a subcutaneous osmotic pump. Rats received either vehicle or atorvastatin (5 mg·kg−1·day−1) by gavage. ANG II infusion resulted in infiltration of inflammatory cells (CD43 immunostaining), oxidative stress (4-hydroxynonenal), hepatic stellate cells (HSC) activation (smooth muscle α-actin), increased intercellular adhesion molecule (ICAM-1), and interleukin-6 hepatic gene expression (quantitative PCR). These effects were markedly blunted in rats receiving atorvastatin. The beneficial effects of atorvastatin were confirmed in an additional model of acute liver injury (carbon tetrachloride administration). We next explored whether the beneficial effects of atorvastatin on ANG II-induced actions are also reproduced at the cellular level. We studied HSC, a cell type with inflammatory and fibrogenic properties. ANG II (10−8M) stimulated cell proliferation, proinflammatory actions (NF-κB activation, ICAM-1 expression, interleukin-8 secretion) as well as expression of procollagen-α1(I) and TGF-β1. All of these effects were reduced in the presence of atorvastatin (10−7M). These results indicate that atorvastatin attenuates the pathogenic events induced by ANG II in the liver both in vivo and in vitro. Therefore, statins could have beneficial effects in conditions characterized by hepatic inflammation.