INTRODUCTION
Polycystic Ovary Syndrome (PCOS) is one of most common and complicated endocrine and metabolic disorder, affecting about 6%-20% women of reproductive age1.In addition to reproductive dysfunction, PCOS can also manifest abnormal glycolipid metabolism while the insulin resistance (IR) is an independent risk factor for several metabolic abnormalities, including dyslipidemia, impaired glucose tolerance, cardiovascular disease and metabolic syndrome(MetS)2-4. The process of follicular development is crucial for reproduction. It needs bi-directional signaling between oocytes and granulosa cells. For patients with PCOS, the associated endocrine and glycolipid metabolic disorder can disrupt normal signal transmission, and then leads to the block of follicular growing, a decrease of high-quality embryos and even reduce the rate of transplantation 5,6.
ANGPTL4 is a member of angiopoietin-like proteins (Angptls) family and is known as a regulator of lipid and glucose metabolism. It is proposed to inhibit activity of the enzyme lipoprotein lipase (LPL), which hydrolyzes triglyceride(TG) core of TG-rich lipoproteins, chylomicrons and very low-density lipoproteins (VLDL), and regulates their distribution to peripheral tissues7-9. A research reported that, there was a significant increase of ANGPTL4 level in serum of patients with PCOS compared with healthy subjects10. Evidence has shown that ANGPTL4 level in serum may positively correlate with PCOS.
Research on ANGPTL4 expression in ovarian granulosa cells (GCs) is still deleted. Therefore, our study aims to investigate the relative expression levels of ANGPTL4 in ovarian granulosa cells in PCOS and examined their possible associations with the glucose and lipid metabolism.