Reciprocal expression of peroxisome proliferator-activated receptor-gamma and cyclooxygenase-2 in human term parturition.
OBJECTIVE
The objective of this study was to test the hypothesis that peroxisome proliferator activated receptor-gamma (PPAR-gamma) is expressed in intrauterine tissues before active term human parturition, and that its repression is associated with up-regulation of cyclooxygenase-2 (COX-2).


METHODS
Specimens were collected from women with term singleton pregnancies after spontaneous labor or cesarean section before labor, prepared for immunoblot and immunohistochemical analysis, and probed for PPAR-gamma or COX-2.


RESULTS
PPAR-gamma expression was prominent in fetal membranes and placenta before active labor. After labor, PPAR-gamma expression was significantly reduced in fetal membranes, but not in placenta. The ratio of COX-2:PPAR-gamma was significantly elevated in fetal membranes with labor. PPAR-gamma immunostaining was prominent in syncytiotrophoblast, extravillous cytotrophoblasts, and cells of the amnion and chorion. COX-2 immunostaining was abundant in the amnion and rare in the placenta.


CONCLUSIONS
PPAR-gamma is highly expressed in term intrauterine tissues. In fetal membranes, PPAR-gamma levels are reduced once active labor commences, coincidental with a relative increase in COX-2 expression.
Dunn-Albanese
Lisa R
LR
Department of Obstetrics and Gynecology, Laboratory of Perinatal Research and Division of Maternal-Fetal Medicine, The Ohio State University, College of Medicine and Public Health, Columbus, Ohio, USA.
Ackerman
William E
WE
Xie
Yubing
Y
Iams
Jay D
JD
Kniss
Douglas A
DA
D000328:Adult; D051546:Cyclooxygenase 2; D005321:Extraembryonic Membranes / Q000378:metabolism; D005260:Female; D005865:Gestational Age; D006801:Humans; D015151:Immunoblotting; D007150:Immunohistochemistry; D007527:Isoenzymes / Q000378:metabolism*; D007743:Labor, Obstetric / Q000502:physiology*; D008565:Membrane Proteins; D036801:Parturition / Q000378:metabolism*; D011247:Pregnancy; D011451:Prostaglandin-Endoperoxide Synthases / Q000378:metabolism*; D018160:Receptors, Cytoplasmic and Nuclear / Q000378:metabolism*; D014018:Tissue Distribution; D014157:Transcription Factors / Q000378:metabolism*; D014599:Uterus / Q000378:metabolism*
D007527:Isoenzymes; D008565:Membrane Proteins; D018160:Receptors, Cytoplasmic and Nuclear; D014157:Transcription Factors; D051546:Cyclooxygenase 2; C496540:PTGS2 protein, human; D011451:Prostaglandin-Endoperoxide Synthases