%0 Journal Article
%T Expression of Nuclear Receptor Coactivators in the Human Fetal Membranes at Term before and after Labor
%A Che-Wei Ryan Ou
%A Meihua Sun
%A Weronika Sadej
%A William Gibb
%J Obstetrics and Gynecology International
%D 2012
%I Hindawi Publishing Corporation
%R 10.1155/2012/717294
%X Human fetal membranes play an important role in term and preterm labor and are responsive to steroids. We examined the expression of steroid receptor coactivators in fetal membranes obtained prior to and following labor at term. Proteins were localized by immunohistochemistry, Western analysis was carried out in nuclear extracts, and mRNA levels were determined by real-time RT-PCR. SRC-1, SRC-2, p300, and PCAF proteins were present in all nuclear extracts. The amnion nuclei expressed higher levels of SRC-1, p300, and PCAF than nuclei from the chorion-decidua, whereas the reverse was true for SRC-2. Chorion-decidua from patients before labor expressed higher levels of SRC-1 than those from patients after labor. Also, the PCAF level was higher in the amnion obtained before labor than the same tissue obtained after labor. In contrast to the protein expression, mRNA levels of SRC-1 and p300 were higher in the chorion-decidua compared to the amnion, whereas there was no difference in levels of SRC-2 and PCAF mRNAs between these two tissues. These data underline that the regulation of the expression of the coactivators in these tissues occurs during labor and is complex and tissue specific. 1. Introduction Preterm birth remains the leading cause of perinatal mortality and morbidity. Despite intensive efforts towards prevention, prompt diagnosis, and use of a variety of tocolytics, the incidence of preterm birth has increased [1]. This is in part due to lack of understanding of the mechanisms responsible for the initiation of labor. Understanding the molecular basis for labor is essential for the prevention, early diagnosis, and effective treatment of preterm labor. The onset of labor in pregnant women involves multiple complex pathways including both endocrine and mechanical signals [2, 3]. In both the human and sheep, glucocorticoids and progesterone appear to play a central role in the parturition. In the fetal membranes, glucocorticoids increase the expression of type 2 prostaglandin H2 synthase (PGHS-2), a rate-limiting enzyme for the production of prostaglandins (PGs), in the amnion cells in culture [4, 5]. Glucocorticoids also inhibit the expression and activity of 15-hydroxyprostaglandin dehydrogenase (PGDH), the major PG degrading enzyme, in the human fetal membranes, and progesterone is believed to tonically stimulate expression of this enzyme [6]. Furthermore, glucocorticoids stimulate the expression of corticotropin-releasing hormone (CRH) in the fetal membranes and placenta [7, 8], and CRH has also been shown to stimulate PG production [9]. These
%U http://www.hindawi.com/journals/ogi/2012/717294/