DIFFERENTIAL EXPRESSION OF MICRORNAS BY ANTI-OBESITY TREATMENT SULFORAPHANE IN SKELETAL MUSCLE OF DIET-INDUCED OBESITY IN MICE

Abstract

Background: Skeletal muscles account for 40-60% of total body weight and are responsible for 30% of resting metabolic rate. They are essential for metabolic homeostasis in the body as they provide the leading site for glucose uptake into tissues by insulin induction. Sulforaphane (SFN), a natural isothiocyanate compound extracted from cruciferous vegetables, acts mainly as an antioxidant; but multiple research studies have shown that it can also act as an anti-obesity drug. Recent studies have shown that microRNAs (miRNAs) play a critical role in regulating skeletal muscle dysfunction; however, their exact mechanism of regulation is not well known. Aim: To study the expression profile of miRNA in the skeletal muscles of diet- induced obesity (DIO) mice treated with SFN and determine their role by identifying pathways and gene ontology involved in the metabolic functions of skeletal muscles. Methods: The study included ten male mice of CD1 strain (five-SFN treated and five-vehicle as control); they were randomized at four weeks old and fed ahigh-fat diet to induce DIO condition. Total RNA was extracted from the skeletal muscles of DIO mice, and small RNA sequencing was utilized to identify the microRNA expression profiles. Pathway mapping and gene ontology (GO) tools were used to evaluate the biological processes and signaling pathways affected by the differentially expressed miRNAs. Results: Body weight, food intake, plasma glucose, and leptin levels were significantly decreased in SFN-treated mice compared to control groups. Furthermore, we identified eight differentially expressed miRNAs in SFN-treated DIO mice, of which five were upregulated (mmu-miR-150-5p, mmu-miR-486a-3p, mmu-miR-126b-5p, mmu-miR-140-3p, mmu-miR-92a-3p) and three were downregulated (mmu-miR-101a-3p, mmu-miR-29c-3p, mmu-miR-3074-5p). Furthermore, we confirmed that SFN treatment dysregulates miRNAs that regulate genes involved in insulin signaling, MAPK, and PI3K/Akt signaling pathways, which are important regulators of skeletal muscle metabolism, including insulin resistance and obesity. Conclusion: Our study showed that SFN induced a change in the expression profiles of miRNAs in the skeletal muscle of DIO mice, which regulate gene targets of miRNAs involved in multiple biological processes to combat obesity.