Very Low Density Lipoprotein and Low Density Lipoprotein Receptor mRNA Expression in Placentae from Preeclamptic Pregnancies and Fetal Growth Restriction

甘油三酯（TG）在胎盘中的转运和代谢途径尚未得到详细研究。本研究探讨了先兆子痫合并妊娠糖尿病（GDM）患者的血脂特征及这些患者的胎胎盘系统脂质代谢。本研究特别检测了极低密度脂蛋白（VLDL）受体mRNA和低密度脂蛋白（LDL）受体mRNA在胎盘中的表达，旨在阐明这些mRNA表达与病理的关系。在我科分娩的妇女（正常孕妇和并发症孕妇）均获得知情同意。测定血清脂质和脂蛋白水平。此外，从人胎盘中获得绒毛组织，并将其作为后续实验的材料。采用AGPC法提取RNA，进行Northern blot。为了比较mRNA的相对表达量，对mRNA表达频带进行扫描和定量分析。子痫前期组和GDM组分娩时TG、VLDL水平明显高于正常妊娠组。VLDL受体mRNA在GDM组显著升高，在子痫前期组显著降低。低密度脂蛋白受体mRNA在正常对照、GDM和子痫前期之间无显著差异。在所有妊娠组中，VLDL受体mRNA表达与脐血TG或VLDL水平呈正相关。在GDM组中，3名出生体重超过3500 g的新生儿脐血中TG和VLDL浓度较高。产后1个月，两种子痫前期组和GDM组血糖虽已恢复正常，但血清TG、VLDL水平仍升高，高密度脂蛋白-胆固醇水平明显降低。本研究首次证明，与正常孕妇相比，子痫前期和GDM患者血液中的脂质，尤其是TG含量过高，而TG是胎盘的能量来源。(2)胎盘中VLDL受体mRNA表达上调；(3)脐血中TG和VLDL水平升高；(4)分娩后1个月仍存在高脂血症。原因推测如下。由于胰岛素抵抗，TG是补偿细胞中葡萄糖利用受损所必需的，而VLDL代谢增加了TG的运输。少

The transport and-metabolic pathway of triglycerides (TG) in the placenta have not been studied in detail. The present study examined the characteristics of blood lipids in patients with Preeclampsia and gestational diabetes mellitus (GDM) and lipid metabolism in the fetoplacental system in these patients. Especially, this study measured the expressions of very low-density lipoprotein (VLDL) receptor mRNA and low-density lipoprotein (LDL) receptor mRNA in the placenta, aiming to elucidate the relationship between these mRNA expressions and the pathology. Informed consent was obtained from women (normal pregnant women and those complication) who delivered at our department. Serum levels of lipids and lipoproteins were measured. In addition, villous tissue was obtained from human placenta, and used as materials in the following experiments. RNA was extracted by the AGPC method, and Northern blot was performed. To compare the relative quantities of mRNA expression, the bands of mRNA expre … More ssion were scanned and quantitated. At delivery in the Preeclampsia and GDM groups, TG, VLDL levels were significantly higher than the levels in the normal pregnancy group. The VLDL receptor mRNA was significantly higher in the GDM group, lower in the Preeclampsia group. No significance difference in the LDL receptor mRNA was observed between the normal control, GDM and Preeclampsia. In all pregnancy groups, a positive correlation was Observed between the VLDL receptor mRNA expression and the TG or VLDL levels in umbilical blood. In the GDM group, three neonates with birth weights over 3500 g had high concentrations of TG and VLDL in the umbilical blood. At 1 month postpartum, although the blood glucose had normalized in a kind of Preeclampsia and GDM groups, serum TG and VLDL levels remained elevated, and high-density lipoprotein-cholesterol level was significantly lowered. The present study demonstrated for the first time that compared to the normal pregnant women, patients with Preeclampsia and GDM had (1)excessive lipids, especially TG, in the blood, which are the energy source in the placenta. (2) showed up-regulation of the expression of VLDL receptor mRNA in the placenta, (3) had elevated TG and VLDL levels in the umbilical blood, and (4) continued to have hyperlipemia even one month after parturition. The reason is speculated as follows. TG is necessary to compensate for impaired glucose utilization in cells because of insulin resistance, and VLDL metabolism is augmented for the transport of TG. Less