Functional study of the upregulation of miRNA-27a and miRNA-27b in 3T3-L1 cells in response to berberine

Abstract

Berberine is the major active component of Rhizoma Coptidis derived from a traditional Chinese herbal medicine and is known to regulate micro (mi)RNA levels, although the mechanism for this action remains unknown. The present study confirmed that treatment of 3T3-L1 cells with berberine inhibited cell viability and differentiation in a dose- and time-dependent manner, and significantly increased the mRNA expression levels of miRNA-27a and miRNA-27b. In addition, in 3T3-L1 cells treated with berberine, overexpression of miRNA-27a and miRNA-27b improved the berberine-mediated inhibition of cell differentiation and reduction of triglyceride contents. By contrast, miRNA-27a and miRNA-27b inhibitors attenuated the berberine-mediated inhibition of cell differentiation and reduction of triglyceride contents. Additionally, peroxisome proliferator-activated receptors (PPAR)-γ was confirmed to be a target of miRNA-27a in the 3T3-L1 cells. A dual-luciferase reporter assay indicated that the expression of PPAR-γ was negatively regulated by miRNA-27a. These findings may provide novel mechanistic insight into the antiobesity effects of certain compounds in traditional Chinese herbal medicine.