The rRole of Intestinal Scavenger Receptor Class B Type I in Chylomicron Production in Normal and Insulin Resistant States

In recent years, studies have revealed a central role for the intestine in regulation of lipid homeostasis and development of insulin resistance and type-2 diabetes. The function of intestinal Scavenger Receptor Class-B type-I remains unknown, however it is believed to play a role in dietary lipid uptake. Recently, our laboratory demonstrated a correlation between intestinal SR-BI expression and chylomicron secretion. We hypothesized that intestinal SR-BI is involved in chylomicron secretion and contributes to chylomicron oversecretion in insulin resistance. I first characterized chylomicron production in healthy and insulin resistant Syrian golden hamsters. Inhibition of SR-BI resulted in reduced postprandial chylomicron accumulation in plasma, and resistance to diet-induced hyperlipidemia and weight-gain. Lower postprandial triglyceride levels were also observed in SR-BI-/- mice. In summary, these data demonstrate a key role for intestinal SR-BI in chylomicron secretion and control of lipid homeostasis, implicating intestinal SR-BI in chylomicron overproduction in insulin resistant states.MAS