Human placental peroxisome proliferator-activated receptor delta and gamma expression in healthy pregnancy and in preeclampsia and intrauterine growth restriction.
OBJECTIVE
Human and animal studies have demonstrated that peroxisome proliferator-activated receptors (PPARs) are important in placental development and play key roles in metabolism and inflammation. We studied placental PPARdelta, PPARgamma, and retinoid X receptor alpha (RXRalpha) expression in healthy pregnancy and in preeclampsia (PET) and intrauterine growth restriction (IUGR).


RESULTS
Using immunocytochemistry, PPARdelta, PPARgamma, and RXRalpha were localized to the cyto- and syncytiotrophoblast and invading trophoblast columns in first and second trimester placentas. Third trimester placentas from healthy pregnancy, and in PET and IUGR, demonstrated PPARdelta, PPARgamma, and RXRalpha staining within the syncytium, and localization within isolated cells in the stroma. In uncomplicated pregnancies, PPARdelta mRNA expression (PPARdelta:18s ratio, third trimester median 0.43 [interquartile (IQ) range 0.26-0.52] vs first trimester 0.20 [0.00-0.26], P = .03) and PPARdelta protein expression (third trimester 3.94 [2.45-4.68] vs first trimester 1.29 [0.78-2.29] optical densitometry [OD] mm(2), P = .04) were higher in the third trimester than in the first trimester. There were no consistent differences in PPARdelta, PPARgamma, or RXRalpha mRNA and protein expression among PET or IUGR placentas and controls.


CONCLUSIONS
PPARdelta expression is up-regulated between the first and third trimester, indicating a role for this nuclear receptor in placental function. We found no evidence that placental PPARdelta, PPARgamma, and RXRalpha expression is changed in PET or IUGR. This suggests that changes in total placental PPAR expression are not involved in the pathophysiology of these conditions.
Division of Developmental Medicine, University of Glasgow, Glasgow Royal Infirmary, Glasgow, United Kingdom. vanessarodie@hotmail.com <vanessarodie@hotmail.com>
Vanessa A
VA
Rodie
Anne
A
Young
Fiona
F
Jordan
Naveed
N
Sattar
Ian A
IA
Greer
D J
DJ
Freeman
D016022:Case-Control Studies; D005260:Female; D005317:Fetal Growth Retardation / Q000503:physiopathology*; D020869:Gene Expression Profiling; D006801:Humans; D007150:Immunohistochemistry; D047494:PPAR delta / Q000096:biosynthesis*; D047495:PPAR gamma / Q000096:biosynthesis*; D010920:Placenta / Q000502:physiology; D011225:Pre-Eclampsia / Q000503:physiopathology*; D011247:Pregnancy / Q000502:physiology*; D011262:Pregnancy Trimester, Second; D011263:Pregnancy Trimester, Third; D047488:Retinoid X Receptors / Q000096:biosynthesis; D015854:Up-Regulation
D047494:PPAR delta; D047495:PPAR gamma; D047488:Retinoid X Receptors