CircRNF111 Protects Against Insulin Resistance and Lipid Deposition via Regulating miR-143-3p/IGF2R Axis in Metabolic Syndrome

Abstract

Abnormal expression of circRNAs (circular RNAs), a subclass of non-coding RNAs, has been documented in numerous human diseases. Herein, we explored whether circRNAs act as ceRNAs (competing endogenous RNAs) to modulate the pathological process-insulin resistance, as well as dyslipidemia of MetS (Metabolic Syndrome). The profile of circRNAs in serume of MetS and control samples was characterized by circRNA deep sequencing. We identified circRNF111 as a key downregulated circRNA involved in MetS. The decreased expression of circRNF111 in the serum samples of MetS was directly linked to excessive insulin resistance and dyslipidemia. Loss-of-function experiments showed that circRNF111 knockdown inhibited the glucose uptake and the Akt signaling pathway, meanwhile increased the deposition of triglycerides in adipogenic differentiated hADSCs (human adipose-derived stem cells). Mechanistically, circRNF111 sponged miR-143-3p and functioned via targeting miR-143-3p along with its downstream target gene IGF2R. The role along with the mechanism of circRNF111 sponging miR-143-3p in MetS was also explored in obese mice triggered by high-fat die. Therefore, our data suggest a protective role of the novel circRNA-circRNF111 in MetS progression. CircRNF111 inhibition enhances insulin resistance and lipid deposition in MetS through regulating miR-143-3p-IGF2R cascade. This provides a promising therapeutic approach for MetS.