Mittal Pooja, Romero Roberto, Mazaki-Tovi Shali, Tromp Gerard, Tarca Adi L, Kim Yeon Mee, Chaiworapongsa Tinnakorn, Kusanovic Juan Pedro, Erez Offer, Than Nandor Gabor, Hassan Sonia S
Perinatology Research Branch, NICHD, NIH, DHHS, Detroit, Michigan, USA.
J Matern Fetal Neonatal Med. 2009 Dec;22(12):1167-75. doi: 10.3109/14767050903019692.
Aquaporin 9 (AQP9) is a water channel protein characterized by its high permeability to nutrients such as lactate and glycerol, as well as urea and other small solutes. These unique properties of AQP9 suggest that this molecule may play a role in the modulation of nutrient flux through the fetal membranes in conditions associated with increased metabolic demand, such as spontaneous labor and inflammation. The objective of this study was to determine the expression of AQP9 in the chorioamniotic membranes from women with and without term labor, as well as those with preterm prelabor rupture of membranes (PPROM) with and without histologic chorioamnionitis.
A cross-sectional study was performed which included patients in the following groups: (1) term not in labor (TNL; n = 14); (2) term, spontaneous labor (n = 14); and (3) PPROM with (n = 20) and without (n = 17) histologic chorioamnionitis. AQP9 mRNA expression in fetal membranes was quantified using quantitative real-time reverse transcription-polymerase chain reaction and analyzed with a linear model including gestational age as a covariate.
(1) AQP9 mRNA expression was identified in all chorioamniotic membrane specimens; (2) AQP9 expression in fetal membranes was significantly higher in spontaneous term labor when compared with TNL (fold change 3.6; p = 0.01); and (3) Among patients with PPROM, the presence of histologic chorioamnionitis was associated with a higher expression of AQP9 in the chorioamniotic membranes compared with those from women without histologic chorioamnionitis (fold change 8.7; p < 0.001).
Aquaporin 9 mRNA expression is higher in the fetal membranes from patients with spontaneous term labor and those with PPROM and histologic chorioamnionitis. These findings are novel, and suggest a role for aquaporin 9 in membrane-mediated transfer of nutrients to support the increased metabolic demands associated with the host immune response of the terminal pathway of parturition and histologic chorioamnionitis.
水通道蛋白9（AQP9）是一种水通道蛋白，其特点是对乳酸、甘油等营养物质以及尿素和其他小分子溶质具有高通透性。AQP9的这些独特特性表明，在与代谢需求增加相关的情况下，如自然分娩和炎症，该分子可能在调节营养物质通过胎膜的通量中发挥作用。本研究的目的是确定AQP9在足月分娩和未足月分娩女性的绒毛羊膜中的表达，以及在有和没有组织学绒毛膜羊膜炎的早产胎膜早破（PPROM）患者中的表达。
进行了一项横断面研究，纳入以下几组患者：（1）足月未临产（TNL；n = 14）；（2）足月自然分娩（n = 14）；（3）有（n = 20）和无（n = 17）组织学绒毛膜羊膜炎的PPROM。使用定量实时逆转录-聚合酶链反应对胎膜中AQP9 mRNA表达进行定量，并采用以胎龄作为协变量的线性模型进行分析。
（1）在所有绒毛羊膜标本中均检测到AQP9 mRNA表达；（2）与TNL相比，足月自然分娩时胎膜中AQP9表达显著更高（倍数变化3.6；p = 0.01）；（3）在PPROM患者中，与无组织学绒毛膜羊膜炎的女性相比，有组织学绒毛膜羊膜炎的患者绒毛羊膜中AQP9表达更高（倍数变化8.7；p < 0.001）。
自然足月分娩患者以及PPROM和组织学绒毛膜羊膜炎患者的胎膜中水通道蛋白9 mRNA表达更高。这些发现是新颖的，并提示水通道蛋白9在膜介导的营养物质转运中发挥作用，以支持与分娩终末途径的宿主免疫反应和组织学绒毛膜羊膜炎相关的增加的代谢需求。
