title: AKR1C1 and SRD5A1 messenger RNA expression at term in the human myometrium and chorioamniotic membranes.
abstract: We sought to determine relative mRNA expression of AKR1C1 and SRD5A1, which respectively encode for the key progesterone metabolizing enzymes, 20alpha-hydroxysteroid dehydrogenase and 5alpha-reductase type 1, in the myometrium and chorioamniotic membranes during human spontaneous or induced labor and nonlabor. Quantitative real-time reverse-transcriptase polymerase chain reaction was used to compare relative mRNA expression of AKR1C1 and SRD5A1 in the myometrium and chorioamniotic membranes from 20 subjects during three different states of labor: not in labor ( N = 10), spontaneous labor ( N = 5), or induced labor ( N = 5). Labor was defined as regular uterine contractions that resulted in cervical dilation. Myometrial AKR1C1 mRNA expression was significantly greater in spontaneously laboring subjects compared with those not in labor (2.4-fold [1.97 to 2.98], P = 0.02). There was no difference in myometrial AKR1C1 mRNA expression between those with induced labor compared with those not in labor. Regardless of labor status, no differences were observed in the chorioamniotic membrane AKR1C1 mRNA expression between the groups. SRD5A1 mRNA expression was significantly lower in the membranes of both laboring groups when compared with those not in labor (spontaneous: 0.10-fold [0.06 to 0.18], P = 0.007; induced: 0.09-fold [0.03 to 0.25], P = 0.013). Regardless of labor status, there was no difference in SRD5A1 mRNA expression in the myometrium. Our study demonstrated tissue-specific changes in progesterone metabolizing enzyme mRNA expression in human intrauterine tissue at term associated with labor status. These observed changes in mRNA expression may have important implications for progesterone metabolism at those specific sites and thereby may differentially regulate the tissue-specific progesterone concentration and/or the level of specific progesterone metabolites.
authors.affiliation: Department of Obstetrics and Gynecology, Women's and Children's Hospital, University of Southern California-Keck School of Medicine, Los Angeles, California 90033, USA. richarhl@usc.edu
authors.forename: Richard H
authors.initials: RH
authors.lastname: Lee
authors.forename: Frank Z
authors.initials: FZ
authors.lastname: Stanczyk
authors.forename: Andrew
authors.initials: A
authors.lastname: Stolz
authors.forename: Qing
authors.initials: Q
authors.lastname: Ji
authors.forename: Gloria
authors.initials: G
authors.lastname: Yang
authors.forename: T Murphy
authors.initials: TM
authors.lastname: Goodwin
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D002585:Cesarean Section; D016009:Chi-Square Distribution; D005321:Extraembryonic Membranes / Q000378:metabolism*; D005260:Female; D005786:Gene Expression Regulation; D005865:Gestational Age; D006801:Humans; D006913:Hydroxysteroid Dehydrogenases / Q000235:genetics* / Q000378:metabolism; D017403:In Situ Hybridization; D007751:Labor, Induced; D007743:Labor, Obstetric; D009215:Myometrium / Q000378:metabolism*; D011247:Pregnancy; D011256:Pregnancy Outcome; D011336:Probability; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012494:Sampling Studies; D012680:Sensitivity and Specificity; D047929:Term Birth; D045002:3-alpha-Hydroxysteroid Dehydrogenase (B-Specific)
chemical_list: D006913:Hydroxysteroid Dehydrogenases; D012333:RNA, Messenger; C435496:AKR1C2 protein, human; D045002:3-alpha-Hydroxysteroid Dehydrogenase (B-Specific)