Astaxanthin Inhibits Alcohol-Induced Inflammation and Oxidative Stress by Mediating the Sirtuin 1 and Histone Deacetylase 4 Axis in Macrophages

Abstract

Abstract Objectives We previously demonstrated that astaxanthin (ASTX), a xanthophyll carotenoid, exerts anti-inflammatory and antioxidant properties in macrophages exposed to ethanol. In this study, to gain mechanistic insight, we explored the role of sirtuin 1 (SIRT1) and histone deacetylase 4 (HDAC4) in the prevention of ethanol-induced inflammation and oxidative stress by ASTX in macrophages. Methods RAW 264.7 macrophages and bone marrow-derived macrophages (BMDMs) isolated from wild-type (WT) and mice with macrophage specific-deletion of HDAC4 (Hdac4MKO) were used. Cells were stimulated with 80 mM ethanol in the absence or presence of 25 mM of ASTX for 72 h. The expression of genes associated with inflammation, SIRT1 and HDAC4 was measured. RAW 264.7 macrophages were treated with sirtinol or resveratrol, which are known inhibitor or activator of SIRT1 activity, respectively, to determine the effect of SIRT1 activity on HDAC4 expression. Parameters related to mitochondrial respiration were determined using a Seahorse XFe24 Extracellular Flux analyzer in both macrophage cell types. Results Ethanol decreased mRNA and protein levels of SIRT1 but increased those of HDAC4, which was attenuated by ASTX in RAW 264.7 macrophages. ASTX abolished an increase in acetylated histone H3 by ethanol in RAW 264.7 macrophages. Knockdown of HDAC4 increased SIRT1 expression, concomitantly decreasing ethanol-induced inflammatory gene expression. Furthermore, BMDMs from Hdac4MKO mice showed significant decreases in ethanol-induced inflammatory genes but an increase in SIRT1 expression compared with WT BMDMs. Ethanol increased mitochondrial respiration, ATP production, and proton leak, but decreased maximal respiration and spare respiratory capacity. The changes by ethanol were abolished by ASTX in RAW 264.7 macrophages. Compared with WT BMDMs, the ethanol-induced alterations in mitochondrial respiration were abrogated in Hdac4MKO BMDMs. Conclusions The anti-inflammatory and antioxidant properties of ASTX in ethanol-treated macrophages may be mediated, at least in part, by the crosstalk between SIRT1 and/HDAC4. This study, therefore, provides new mechanisms in preventing the alcohol-induced inflammation and oxidative stress through the crosstalk between SIRT1 and HDAC4. Funding Sources This study was supported by NIH 1R01DK108254–01.