Wang Y, Gu Y, Zhang Y, Lewis D F, Alexander J S, Granger D N
Department of Obstetrics and Gynecology, Louisiana State University Health Sciences Center, Shreveport, LA 71130, USA.
Placenta. 2007 Apr;28(4):263-9. doi: 10.1016/j.placenta.2006.03.012. Epub 2006 May 15.
Placenta-derived chymotrypsin-like protease (CLP/chymase) promotes endothelial P-selectin and E-selectin expression, which may be responsible for the increased neutrophil/endothelial interactions in preeclampsia (PE). However, little is known about this protease expression and production in human placenta. This study was undertaken to determine the distribution and gene expression of CLP in human placenta. Human placental tissues were obtained immediately after delivery from normal and PE pregnancies. We examined (1) CLP/chymase immunoactivity by immunohistochemical staining of villous tissue sections; (2) trophoblast mRNA and protein expression for chymase by RT-PCR and Western blot analysis; (3) chymase cDNA sequencing in isolated trophoblast cells (TCs); and (4) release of CLP by placental villous tissue cultured under 2% and 20% O(2). We found (1) CLP expression is mainly localized in the epithelial layer of syncytiotrophoblasts; (2) both mRNA and protein expression are significantly (p<0.05) upregulated in TCs isolated from PE vs. normal placentas; (3) TC chymase cDNA sequence and the deduced amino acid sequence are 100% identical to that reported for the human heart; and (4) villous tissue releases more chymotrypsin when cultured with 2% O(2). We conclude that (1) the DNA and protein sequence for chymase in placental trophoblast cells are the same as those reported in the human heart; (2) CLP/chymase expression is upregulated in TCs during PE; and (3) lowered oxygen condition promotes CLP release by placental TCs. Since chymase is a potent non-ACE angiotensin II producing enzyme, our data suggest that if placenta-derived CLP/chymase is released into the maternal circulation, it may contribute to the cardiovascular complications associated with PE.
胎盘来源的类胰凝乳蛋白酶（CLP/糜酶）可促进内皮细胞P选择素和E选择素的表达，这可能是子痫前期（PE）中中性粒细胞/内皮细胞相互作用增加的原因。然而，关于这种蛋白酶在人胎盘中的表达和产生情况知之甚少。本研究旨在确定CLP在人胎盘中的分布和基因表达。在正常和PE妊娠分娩后立即获取人胎盘组织。我们进行了以下研究：（1）通过绒毛组织切片的免疫组织化学染色检测CLP/糜酶免疫活性；（2）通过逆转录聚合酶链反应（RT-PCR）和蛋白质印迹分析检测滋养层细胞中糜酶的mRNA和蛋白质表达；（3）对分离的滋养层细胞（TCs）中的糜酶cDNA进行测序；（4）在2%和20%氧气条件下培养胎盘绒毛组织，检测CLP的释放情况。我们发现：（1）CLP表达主要定位于合体滋养层的上皮层；（2）与正常胎盘分离的TCs相比，PE胎盘分离的TCs中mRNA和蛋白质表达均显著上调（p<0.05）；（3）TCs糜酶cDNA序列和推导的氨基酸序列与报道的人心肌序列100%相同；（4）绒毛组织在2%氧气条件下培养时释放更多的胰凝乳蛋白酶。我们得出以下结论：（1）胎盘滋养层细胞中糜酶的DNA和蛋白质序列与报道的人心肌序列相同；（2）PE期间TCs中CLP/糜酶表达上调；（3）低氧条件促进胎盘TCs释放CLP。由于糜酶是一种有效的非血管紧张素转换酶（ACE）血管紧张素II产生酶，我们的数据表明，如果胎盘来源的CLP/糜酶释放到母体循环中，可能会导致与PE相关的心血管并发症。
