Induction of surfactant protein A expression by cortisol facilitates prostaglandin synthesis in human chorionic trophoblasts.
BACKGROUND
Surfactant protein A (SP-A) may be an important link between the maturation of fetal organs and the initiation of parturition. However, the local expression of SP-A and the effect of SP-A on prostaglandin synthesis in human fetal membranes have not been resolved.


OBJECTIVE
Our objective was to examine SP-A expression and the effect of SP-A on prostaglandin synthesis in human fetal membranes.


METHODS
SP-A expression was examined with immunohistochemistry and PCR. The effect of SP-A on prostaglandin synthesis was investigated in cultured human chorionic trophoblasts.


METHODS
Patients were normal-term pregnant women undergoing elective cesarean sections.


RESULTS
Both SP-A protein and mRNA were present in amnion epithelial cells, fibroblasts, and chorionic trophoblasts. Cortisol (10(-7) and 10(-6) M, 24 h) induced SP-A expression in cultured chorionic trophoblasts, which could be blocked by the glucocorticoid receptor antagonist RU486. Treatment of chorionic trophoblasts with SP-A (10-100 microg/ml, 24 h) caused a dose-dependent increase of prostaglandin E2 release and an induction of cyclooxygenase type 2 but not cytosolic phospholipase A2 and microsomal prostaglandin E synthase expression.


CONCLUSIONS
SP-A can be synthesized locally in human fetal membranes, which can be induced by glucocorticoids. SP-A appeared to induce prostaglandin E2 synthesis in chorionic trophoblasts via induction of cyclooxygenase type 2 expression.
Sun
Kang
K
Department of Obstetrics and Gynecology, College of Medicine, University of Cincinnati, 231 Albert Sabin Way, Cincinnati, Ohio 45267, USA. sunkang2000@yahoo.com
Brockman
Diane
D
Campos
Begona
B
Pitzer
Brad
B
Myatt
Leslie
L
D002478:Cells, Cultured; D002823:Chorion / Q000166:cytology* / Q000378:metabolism; D015232:Dinoprostone / Q000378:metabolism; D005321:Extraembryonic Membranes / Q000378:metabolism; D005260:Female; D015870:Gene Expression; D006801:Humans; D006854:Hydrocortisone / Q000494:pharmacology*; D011247:Pregnancy; D011451:Prostaglandin-Endoperoxide Synthases / Q000378:metabolism; D011453:Prostaglandins / Q000096:biosynthesis*; D037662:Pulmonary Surfactant-Associated Protein A / Q000378:metabolism* / Q000494:pharmacology / Q000502:physiology; D014018:Tissue Distribution; D014327:Trophoblasts / Q000378:metabolism*
D011453:Prostaglandins; D037662:Pulmonary Surfactant-Associated Protein A; D011451:Prostaglandin-Endoperoxide Synthases; D015232:Dinoprostone; D006854:Hydrocortisone