[n-3 Polyunsaturated fatty acid attenuates hyperhomocysteinemia-induced hepatic steatosis by increasing hepatic LXA5 content].

Nonalcoholic fatty liver disease (NAFLD) and hyperhomocysteinemia (HHcy) both are major health problems worldwide, whose incidence are closely related with each other. We previously reported the mechanism of HHcy-caused hepatic steatosis, but the role of n-3 polyunsaturated fatty acid (n-3 PUFA) in HHcy-induced hepatic steatosis remains unclear. In this study, 6-week-old C57BL/6 male mice were given a high methionine diet (HMD, 2% methionine diet), and plasma homocysteine levels were measured by ELISA to confirm the establishment of an HHcy model. Meantime, mice were fed HMD with or without n-3 PUFA supplement for 8 weeks to determine the role and mechanism of n-3 PUFA in hepatic steatosis induced by HHcy. Results showed that n-3 PUFA significantly improved hepatic lipid deposition induced by HHcy. qRT-PCR analysis demonstrated that n-3 PUFA inhibited the upregulation of Cd36, a key enzyme of fatty acid uptake, caused by HHcy. Further, the inhibition of hepatic Cd36 expression was associated with the inactivation of aryl hydrocarbon receptor (Ahr) induced by n-3 PUFA. Of note, mass spectrometry revealed that hepatic content of lipoxin A5 (LXA5) was significantly increased in HMD+n-3 PUFA-fed mice compared with that in HMD-fed mice. In primary cultured hepatocytes, LXA5 treatment markedly reversed homocysteine-evoked Cd36 upregulation and Ahr activation, which resulted in reduced lipid accumulation. In conclusion, we demonstrate that n-3 PUFA inactivates HHcy-induced Ahr-Cd36 pathway by increasing hepatic LXA5 content, which alleviates hepatic steatosis. Thus, our results may provide a potential strategy for treatment of NAFLD.