Nicotine-mediated upregulation of microRNA-141 expression determines adipokine-intervened insulin resistance

MicroRNAs (miRNAs) are non-coding RNAs that are associated with adipokine homeostasis and insulin resistance. Whereas, smoking can disturb metabolic homeostasis. Present study was aimed to investigate the level of miRNA-141 in experimental animal model that were exposed with graded doses of nicotine. We further aimed to investigate the possible interplay of miRNA-141 expression change with adipokine homeostasis and occurrence of insulin resistance in nicotine-exposed experimental animals. Nicotine (0.5, 1.0, 3.0 and 6.0 mg/Kg) was administered to early adolescent; postnatal days ranging from 25-30 Wistar rats for one month. Serum was analyzed for leptin, adipokines, IL-6, MDA, HbA1c, insulin, G6PDH, hexokinase, and lipid profile. While miRNA-141 expression level was determined in plasma. Higher doses of nicotine were associated with higher glucose, HbA1c, leptin, IL-6, MDA and lipids levels, while, insulin, adiponectin, G6PDH, hexokinase and HDL levels were lower. Higher doses of nicotine also impaired glucose tolerance and exhibited significant increase in miR-141 expression signifying that nicotine exposure may influence adipokines regulation altering glycemic profile. This is accompanied with aggravated inflammatory responses where genetic expression of miRNA-141 can be an accessible biomarker for metabolic disturbances with insulin resistance and glucose intolerance.

Keywords: Inflammatory biomarkers; glucose tolerance; insulin resistance; metabolic homeostasis; nicotine exposure.