Aquaporin 8 expression in human placenta and fetal membrane / 中国组织工程研究

ABSTRACT

BACKGROUND: Placenta and fetal membrane play an important role In maternal-fetal homeostasis. However, the molecular and cellular mechanisms underlying water transfer across placenta and amniotic membrane remain unknown. It is hypothesized that maternal-fetal fluid exchanges via aquaporin (AQP) water channels in the placenta and fetal membrane.OBJECTIVE: To investigate AQP8 protein expression in normal human placenta and fetal membrane.DESIGN, TIME AND SETTING: A control observation was performed at the Central Laboratory of Guangzhou Medical College from July to December 2005.MATERIALS Human placenta and fetal membrane tissues from 5 elective cesarean section deliveries of normal term pregnancies (range 37-42 weeks) were studied. Maternal age averaged (27?) years old. Experimental protocol was approved by the Hospital's Ethics Committee.METHODS: Thirty minutes after delivery, fetal membrane and placenta were dissected and washed with sterile physiological saline. Some were frozen at -80?, and the remaining tissues were fixed for 24-48 hours with 10% neutral formalin and paraffin embedded for immunohistochemical staining.MAIN OUTCOME MEASURES: AQP8 expression and distribution in human placenta and fetal membrane were detected by the reverse transcription-polymerase chain reaction (RT-PCR), immunohistochemistry, and Western blotting analysis.RESULTS: RT-PCR results showed that AQP8 mRNA was expressed in both placenta and fetal membrane tissues. Western blotting analysis also yielded positive results in placenta and fetal membrane with a specific band site at approximately 45 000.Immunohistochemistry results revealed that AQP8 protein was expressed in placental syncytiotrophoblasts, amniotic epithelial cells, and chorion cytotrophoblasts.CONCLUSION: At protein level, AQP8 is expressed in placental syncytiotrophoblasts, amniotic epithelial cells, and chorion cytotrophoblasts.