PPAR Function in human pregnancy and preeclampsia

描述（由申请方提供）：本提案的目的是表征过氧化物酶体激活受体（PPARs）在正常人妊娠中以及在妊娠综合征、先兆子痫（PE）相关代谢紊乱中的功能。在美国，PE是造成20%的孕产妇死亡的原因。PE突然发生在妊娠的第二或第三个月，其特征是高血压、蛋白尿和全身水肿。PE的原因仍然难以捉摸，唯一有效的治疗方法是立即分娩婴儿，由于早产并发症导致婴儿发病率和死亡率高。因此，母亲和孩子都因这种综合症而遭受严重的健康风险。本研究旨在探讨正常妊娠时母体能量代谢的调节机制及其在PE中的可能变化。虽然它们不像经典的三重PE符号那样被广泛认可（即，高血压、蛋白尿和水肿）、血脂异常、肥胖和异常葡萄糖耐量也是PE综合征的常见方面。PPARs在脂质和葡萄糖代谢的调节中起着关键作用，我们已经证明，循环中的PPARs激活剂在正常妊娠过程中增加。在具体目标1中，我们建议使用质谱法作为我们现有HPLC分析的辅助手段，以鉴定妊娠血浆中存在的PPAR激活剂。配体结合测定将确定所鉴定的化合物是否是PPARs的直接高亲和力配体。我们还将确定哪些特定的PPARs被循环化合物结合和激活。在特定目标2中，我们选择了两个候选基因（人胎盘催乳素[hPL]和血管内皮生长因子[VEGF]），它们在胎盘生长和功能中起关键作用。我们的初步研究表明，PPARs可以调节这两个基因，并且这两个基因产物的表达在PE中改变。使用PPARg的特异性抑制剂，将定量全部或部分归因于PPARg活性的hPL和VEGF的表达和分泌的差异。在具体目标3中，将在正常妊娠和PE妊娠中检查已知改变体内PPAR功能的PPAR多态性的频率。PCR扩增编码每个特定基因突变的区域，然后进行诊断性限制性内切酶消化，以对正常和PE妊娠的母亲和婴儿进行基因分型。 这些基因中的单核苷酸多态性也将被寻找。我们预期，我们的多方面的方法来阐明正常妊娠和PE中的PPAR作用，将为潜在的病理生理学提供新的线索，并最终治疗PE及其临床并发症。

DESCRIPTION (provided by applicant): The objective of this proposal is to characterize the function of Peroxisome Proliferator-Activated Receptors (PPARs) in normal human pregnancy, and in the metabolic disturbances associated with the pregnancy syndrome, preeclampsia (PE). PE is responsible for 20% of maternal deaths in the U.S. PE occurs suddenly in the late second or third trimester of pregnancy and is characterized by high blood pressure, proteinuria, and generalized edema. The cause of PE remains elusive, and the only effective treatment is immediate delivery of the baby, resulting in high levels of infant morbidity and mortality due to complications of premature birth. Thus, both mother and child suffer serious health risks due to this syndrome. This project will evaluate PPAR regulation of maternal energy metabolism in normal pregnancy, and its possible alteration in PE. Although they are not as widely recognized as the classical triad of PE signs (i.e., hypertension, proteinuria and edema), dyslipidemia, obesity and aberrant glucose tolerance also are common facets of the PE syndrome. PPARs play critical roles in the regulation of lipid and glucose metabolism, and we have demonstrated that circulating PPAR activators increase during the course of normal pregnancy. In Specific Aim 1, we propose to use mass spectrometry, as an adjunct to our existing analyses by HPLC, to identify the PPAR activator(s) present in pregnancy plasma. Ligand binding assays will determine whether the identified compound(s) is a direct high affinity ligand of PPARs. We also will determine which specific PPARs are bound and activated by the circulating compound(s). In Specific Aim 2, we have selected two candidate genes (human placental lactogen [hPL] and vascular endothelial growth factor [VEGF]) that play key roles in placental growth and function. Our preliminary studies indicate that PPARs can regulate both genes and that the expression of both gene products is altered in PE. Using a specific inhibitor of PPARg, differences in expression and secretion of hPL and VEGF, due in whole or in part to PPARg activity, will be quantified. In Specific Aim 3, the frequency of PPAR polymorphisms known to alter PPAR function in vivo will be examined in both normal and PE pregnancy. PCR amplification of regions encoding each specific genetic mutation will be followed by diagnostic restriction enzyme digestion in order to genotype both mothers and babies of normal and PE pregnancies. Single nucleotide polymorphisms in these genes also will be sought. We anticipate that our multi-faceted approach to elucidate the role of PPAR action in normal pregnancy and PE will provide new clues to the underlying pathophysiology, and ultimately, therapy of PE and its clinical complications.