The role of apolipoprotein C4 in vascular endothelial cell injury in hypertensive disorder of pregnancy

Abstract

Objective Find abnormal changes of plasma lipid metabolism-related proteins before 20 weeks of gestation in patients with hypertensive disorder of pregnancy(HDP), and preliminarily investigate the role of plasma apolipoprotein C4 elevation in HDP. Methods A nested case-control study was used. The plasma were collected from pregnant women who underwent routine prenatal examination in Guangzhou Women and Children′s Medical Center from November 2014 to March 2017. Label-free mass spectrometry was used to detect the differences in plasma lipid metabolism-related proteins before 20 weeks of gestation between 12 pairs of HDP patients and normal controls, and different 48 pairs of samples were used for verification. The protein with the most significant difference multiples was screened to study its effects on monolayer permeability and nitric oxide secretion of endothelial cells. One-way ANOVA was used for comparison between groups, and P<0.05 was considered as statistically significant difference. Results Compared with the control, the lipid metabolism-related proteins, APOC4, Fatty acid-binding protein 4 (FABP4), Apolipoprotein E (APOE), Apolipoprotein C3 (APOC3) and Beta-2-glycoprotein 1(APOH) raised to 1.94, 1.82, 1.59, 1.55 and 1.38 times, phospholipid transfer protein (PLTP) decreased to 0.78 times in plasma before 20 weeks of pregnancy of patients with HDP (t value were 2.499, 2.497, 2.081, 2.098, 2.426 and 2.564, respectively, P<0.05). Cell experiments results showed that 50 ng/ml APOC4 significantly increased 20% HUVEC single layer cell permeability to FITC-labeled dextran (F=455.4, P<0.01), and significantly decreased the level of nitric oxide in the supernatant of HUVEC culture by 25% (F=61.92, P<0.01). Conclusions Before diagnosis, plasma protein levels involved in lipid metabolism in HDP patients have been changed, resulting in abnormal lipid metabolism. APOC4 can increase the permeability of vascular endothelial cells, inhibit endothelial source of NO secretion, cause endothelial dysfunction. Key words: Apolipoprotein C4; Hypertensive disorder of pregnancy; Endothelial cell injury