%0 Journal Article
%T Human Serum PCSK9 Is Elevated at Parturition in Comparison to Nonpregnant Subjects While Serum PCSK9 from Umbilical Cord Blood is Lower Compared to Maternal Blood
%A Patricia Peticca
%A Angela Raymond
%A Andr¨¦e Gruslin
%A Marion Cousins
%A Ejibunmi Adetola
%A Hussein Abujrad
%A Janice Mayne
%A Teik Chye Ooi
%J ISRN Endocrinology
%D 2013
%R 10.1155/2013/341632
%X Background. Serum lipids including total cholesterol (TC), triglycerides (TG), and low density lipoprotein cholesterol (LDL-C) are increased in pregnancy. Serum proprotein convertase subtilisin kexin 9 (PCSK9) is a significant player in lipoprotein metabolism. Circulating PCSK9 downregulates the LDL receptor on the surface of the liver, inhibiting clearance of LDL-C. Therefore, our study assessed serum PCSK9 concentrations at parturition (Maternal) compared to a nonpregnant (Control) cohort, as well as between mother and newborn (Maternal and Newborn). Methods. Blood was collected from women at parturition and from umbilical cords. Serum lipids and PCSK9 were measured and data were analysed for significance by Mann-Whitney test at and presented as median levels. Spearman's correlations were made at a 95% confidence interval. Results. Serum PCSK9 was significantly higher in Maternal versus Control cohorts (493.1 versus 289.7£¿ng/mL; , resp.), while the Newborn cohort was significantly lower than Maternal (278.2 versus 493.1£¿ng/mL; , resp.). PCSK9 was significantly correlated with TC and HDL-C in Maternal and with TC, LDL-C, and HDL-C in Newborn cohorts. Conclusions. Our study provides the first quantitative report on PCSK9 in pregnancy (at parturition) and in umbilical cord blood. Further research will determine how these changes may affect lipoprotein levels during this physiological state. 1. Introduction Pregnancy is associated with steady increases in maternal serum concentrations of total cholesterol (TC) and low density lipoprotein cholesterol (LDL-C) from first to third trimester [1, 2]. Other changes include an increase in high density lipoprotein cholesterol (HDL-C), triglycerides (TG), serum apolipoprotein B (apoB), and apolipoprotein AI (apoAI) levels and a net increase in the apoB/apoAI ratio [1, 2]. In contrast, umbilical cord blood has lower lipid levels than adults, including TG, LDL-C, and HDL-C subfractions [3]. In addition, HDL is the major cholesterol-containing particle in cord blood, unlike adult blood where it is LDL [3]. The molecular mechanisms involving lipoprotein changes during pregnancy and their influence on cord blood levels have yet to be fully elucidated [3]. Proprotein convertase subtilisin kexin 9 (PCSK9), a secreted glycoprotein and member of the proprotein convertase family of mammalian serine proteases, has emerged as a significant player in lipoprotein metabolism since its discovery in 2003 [4]. Population studies have shown that PCSK9 gain of function variants associate with high LDL-C levels and autosomal dominant
%U http://www.hindawi.com/journals/isrn.endocrinology/2013/341632/