Effects and relationship of intermittent hypoxia on serum lipid levels, hepatic low-density lipoprotein receptor-related protein 1, and hypoxia-inducible factor 1α.

Abstract

This study investigated the influence of intermittent hypoxia on serum lipid level, hepatic low-density lipoprotein receptor-related protein (LRP)1, and hepatic hypoxia-inducible factor (HIF)-1α and the underlying mechanisms of action. Male Sprague Dawley rats were subjected to different levels of hypoxia. After 1-4 weeks hypoxemia, routine blood tests were performed and the levels of LRP1 and HIF-1α in liver were examined. Intermittent hypoxia (IH) was induced in HepG2 cells with or without HIF-1α inhibitor YC-1 pretreatment, and the levels of LRP1 and HIF-1α in cells were examined. IH caused elevated serum triglyceride, cholesterol, low-density lipoprotein, and high-density lipoprotein in rats. IH caused elevated hepatic levels of LRP1 and HIF-1α. After pretreatment with YC-1, HIF-1α protein expression decreased but mRNA expression did not change in HepG2 cells. IH caused dyslipidemia and elevated LRP1 and HIF-1α. Elevated LRP1 expression was caused by HIF-1α.