Berberine ameliorates obesity-induced chronic inflammation through suppression of ER stress and promotion of macrophage M2 polarization at least partly via downregulating lncRNA Gomafu

Background: Berberine has been established as a potential drug for inflammation and metabolic disorder. Here, we aimed to explore the effects and the underlying mechanisms of berberine on obesity-induced chronic inflammation. Methods: Mice were fed with high-fat diet to induce obesity. Inflammation in adipocytes were induced with treatment of free fatty acids. The expression of IL-4, CD206, ARG1 and other markers were used to identify M1 and M2 polarization. The expression of GPR78 and CHOP were used to evaluate endoplasmic reticulum stress. H&E staining was used to reveal the adipose tissue macrophage and adipocytes enlargement. Results: Berberine treatment attenuated endoplasmic reticulum stress and inflammation in obese mice and free fatty acids-treated adipocytes. Overexpression of lncRNA Gomafu partially blocked the protective effects of berberine in free fatty acids-treated adipocytes by increasing endoplasmic reticulum stress. Moreover, Gomafu overexpression partly reversed berberine-induced enhancement of M2 polarization in macrophages. Finally, Gomafu overexpression induced ER stress and inflammation in mice, which were improved by berberine administration. Conclusions: Berberine improves obesity-induced chronic inflammation by alleviating endoplasmic reticulum stress and consequently promoting macrophage M2 polarization. And these protective effects were mediated at least partly by the suppression of lncRNA Gomafu.