Department of Rheumatology (YJZ,XFL), Qilu Hospital, Shandong University, Jinan 250012, Shandong, P.R. China.
J Histochem Cytochem. 2014 May;62(5):347-54. doi: 10.1369/0022155414521213. Epub 2014 Jan 14.
G-proteins mediate cellular function upon interaction with G-protein coupled receptors. Of the 16 mammalian G-protein α subunits identified, G-protein subunit α-11 (GNA11) and -14 (GNA14) have been implicated in modulating hypertension and endothelial function. However, little is known about their expression and roles in human placentas. Here, we examined GNA11 and GNA14 protein expression in first trimester (FT), normal term (NT), and severe preeclamptic (sPE) human placentas as well as in NT human umbilical cords. We found that GNA11 and GNA14 were immunolocalized primarily in trophoblasts, villous stromal cells, and endothelial cells in placentas as well as in endothelial and/or smooth muscle cells of the umbilical cord artery and vein. Western blotting revealed that the GNA14, but not GNA11, protein levels were increased (2.5-2.9 fold; p<0.01) in sPE vs. NT placentas. GNA11 protein was detected only in NT, but not FT, placentas, whereas GNA14 protein levels were increased (7.7-10.6 fold; p<0.01) in NT vs. FT placentas. Thus, GNA11 and GNA14 may mediate the function of several cell types in placentas. Moreover, the high expression of GNA14 in sPE placentas may also imply its importance in sPE pregnancies as in the other hypertension-related disorders.
G 蛋白通过与 G 蛋白偶联受体相互作用来介导细胞功能。在鉴定出的 16 种哺乳动物 G 蛋白α亚基中，G 蛋白亚基α-11（GNA11）和-14（GNA14）已被证明可调节高血压和内皮功能。然而，它们在人胎盘中的表达和作用知之甚少。在这里，我们检测了 GNA11 和 GNA14 蛋白在早孕（FT）、正常足月（NT）和严重子痫前期（sPE）人胎盘中的表达，以及在 NT 人脐带上的表达。我们发现 GNA11 和 GNA14 主要在胎盘的滋养层细胞、绒毛间质细胞和内皮细胞中以及脐动脉和静脉的内皮细胞和/或平滑肌细胞中免疫定位。Western blot 显示，与 NT 胎盘相比，sPE 胎盘中的 GNA14 蛋白水平增加了（2.5-2.9 倍；p<0.01），而 GNA11 蛋白水平没有变化。GNA11 蛋白仅在 NT 胎盘中检测到，而在 FT 胎盘中未检测到，而 GNA14 蛋白水平在 NT 胎盘中增加了（7.7-10.6 倍；p<0.01）。因此，GNA11 和 GNA14 可能介导胎盘内几种细胞类型的功能。此外，sPE 胎盘中 GNA14 的高表达也暗示了它在 sPE 妊娠中的重要性，就像在其他与高血压相关的疾病中一样。
