Qi Hongbo, Li Li, Zong Wenjun, Hyer Barb J, Huang Jin
Department of Obstetrics and Gynecology, First Affiliated Hospital, Chongqing Medical University, Chongqing, China.
J Obstet Gynaecol Res. 2009 Dec;35(6):1019-25. doi: 10.1111/j.1447-0756.2009.01061.x.
Water absorption across fetal chorioamniotic membranes is a critical regulatory pathway for amniotic fluid volume homeostasis. Aquaporin 8 (AQP8) is a water channel regulating osmotic water travel across membranes. This study was to investigate the distribution and expression of AQP8 in amnion epithelial cells (AEC) in response to different osmotic stresses.
Cells derived from the amnion were subjected to different osmotic culture media. Reverse transcriptase-polymerase chain reaction, Western blotting and immunofluorescence analysis were used to determine expression and localization of AQP8.
Immunofluorescent staining confirmed the expression of AQP8 on cytomembrane and in cytoplasm. Hypotonic media increased AQP8 on cytomembrane of AEC. Compared to isosmolar media, hypotonic media significantly enhanced AQP8 mRNA and protein expression (P < 0.05), while hypertonic media significantly decreased expression (P < 0.05).
The expression and distribution of AQP8 in AEC are diversely regulated by osmotic loads suggesting a role for AQP8 in intramembranous water transport and the balance of amniotic fluid.
胎儿绒毛膜羊膜的水吸收是羊水容量稳态的关键调节途径。水通道蛋白8（AQP8）是一种调节跨膜渗透水转运的水通道。本研究旨在探讨不同渗透压应激下AQP8在羊膜上皮细胞（AEC）中的分布及表达情况。
将来源于羊膜的细胞置于不同渗透压的培养基中培养。采用逆转录聚合酶链反应、蛋白质免疫印迹法及免疫荧光分析法检测AQP8的表达及定位。
免疫荧光染色证实AQP8在细胞膜及细胞质中均有表达。低渗培养基可增加AEC细胞膜上的AQP8表达。与等渗培养基相比，低渗培养基显著增强了AQP8 mRNA及蛋白表达（P<0.05），而高渗培养基则显著降低了其表达（P<0.05）。
渗透压负荷对AEC中AQP8的表达及分布具有不同的调节作用，提示AQP8在膜内水转运及羊水平衡中发挥作用。
