Maternal obesity programs hypothalamic miR-505-5p expression in mouse offspring and impacts hypothalamic fatty acid sensing

Abstract

AbstractIn utero exposure to maternal obesity programs a susceptibility to develop obesity. Animal models have shown that offspring obesity is often preceded by increased food intake, however, the mechanisms that mediate these changes are not understood. Using a mouse model of maternal diet-induced obesity we observed increased intake specifically of a high-fat pellet in adult offspring of obese mothers. Through small RNA sequencing, we identified programmed overexpression of miR-505-5p in the hypothalamus of offspring of obese mothers that is established in the fetus, and confirmed in vitro that fatty acid exposure increases expression of miR-505-5p. Pulsed SILAC analysis demonstrated protein targets of miR-505-5p are enriched in pathways involved in fatty acid metabolism. These include key components of neuronal fatty acid sensing, such as Cpt1a, that are implicated in BMI regulation in human genetic studies. Over-expression of miR-505-5p decreased neuronal fatty acid uptake and metabolism in vitro. Importantly, intra-cerebroventricular injection of a miR-505-5p mimic in mice resulted in increased high-fat pellet intake. Collectively these data suggest that maternal obesity induces over-expression of miR-505-5p in offspring hypothalamus, resulting in altered fatty acid sensing and increased intake of high-fat diet. This represents a novel mechanism by which maternal obesity programs obesity in offspring.