MicroRNA-218 targets adiponectin receptor 2 to regulate adiponectin signaling.

Adiponectin exerts an antidiabetic function through the adiponectin receptors 1 and 2 (AdipoR1 and AdipoR2). The mechanism regulating the expression of adiponectin receptors remains to be elucidated. Bioinformatics analysis demonstrated that microRNA (miR)‑218 targets the 3' untranslated region (3'UTR) of the AdipoR2 mRNA. The present study aimed to investigate whether miR-218 regulated the expression of AdipoR2 using immunoblotting, reverse transcription quantitative polymerase chain reaction and luciferase assays. The protein level and the mRNA level of AdipoR2 were reduced when miR‑218 was expressed in HepG2 cells. Additionally, overexpression of miR‑218 repressed the activity of a luciferase reporter containing the 3'UTR of AdipoR2. Furthermore, the present study aimed to determine whether miR-218 regulated glucose metabolism through detecting signaling pathways and glucose uptake. The phosphorylation of AMP‑activated protein kinase and p38 mitogen‑activated protein kinase was reduced in miR‑218‑expressing cells. In addition, miR‑218 inhibited adiponectin‑induced glucose uptake. The present results suggested that miR‑218 targets AdipoR2 to inhibit adiponectin signaling.