Ackerman William E, Summerfield Taryn L, Mesiano Sam, Schatz Frederick, Lockwood Charles J, Kniss Douglas A
Division of Maternal-Fetal Medicine and Laboratory of Perinatal Research, Department of Obstetrics and Gynecology, The Ohio State University, College of Medicine and Wexner Medical Center, Columbus, OH, USA.
Department of Obstetrics, Gynecology and Reproductive Sciences, Case Western Reserve University, School of Medicine, Cleveland, OH, USA.
Reprod Sci. 2016 Jan;23(1):112-23. doi: 10.1177/1933719115597787. Epub 2015 Aug 4.
Progesterone (P(4)) maintains uterine quiescence during the majority of pregnancy, whereas diminished progesterone receptor (PR) expression and/or activity (ie, functional P(4) withdrawal) promotes parturition. To investigate the regulation of PR expression in cervical stroma, fibroblasts from premenopausal hysterectomy specimens were prepared. Greater than 99% of the cultures were vimentin positive (mesenchymal cell marker) with only occasional cytokeratin-8 positivity (epithelial cell marker) and no evidence of CD31-positive (endothelial cell marker) cells. Cells were immunolabeled with antibodies directed against PRs (PR-A and PR-B), estrogen receptor α (ER-α), and glucocorticoid receptor-α/β (GR-α/β). All cells were uniformly immunopositive for ER-α and GR-α/β but did not express PRs. Incubation of cells with 10(-8) mol/L 17β-estradiol induced a time-dependent increase in PR-A and PR-B messenger RNAs (mRNAs) by quantitative real-time polymerase chain reactions and proteins by immunoblotting and immunofluorescence. Incubation of cervical fibroblasts with PR ligands (medroxyprogesterone acetate or Org-2058) downregulated PR-A and PR-B levels. Coincubation of cells with PR ligands plus RU-486, a PR antagonist, partially abrogated agonist-induced receptor downregulation. Dexamethasone, a pure glucocorticoid, had no inhibitory effect on PR expression. These results indicate that progestins and estrogens regulate PR expression in cervical fibroblasts. We postulate that hormonal regulation of PR expression in the cervical stroma may contribute to functional P(4) withdrawal in preparation for parturition.
孕酮（P(4)）在孕期的大部分时间维持子宫静息状态，而孕酮受体（PR）表达和/或活性降低（即功能性P(4)撤退）会促进分娩。为了研究宫颈基质中PR表达的调控，制备了来自绝经前子宫切除标本的成纤维细胞。超过99%的培养细胞波形蛋白呈阳性（间充质细胞标志物），只有偶尔的细胞角蛋白-8呈阳性（上皮细胞标志物），且没有CD31阳性（内皮细胞标志物）细胞的证据。用针对PRs（PR-A和PR-B）、雌激素受体α（ER-α）和糖皮质激素受体-α/β（GR-α/β）的抗体对细胞进行免疫标记。所有细胞对ER-α和GR-α/β均呈均匀免疫阳性，但不表达PRs。用10(-8) mol/L 17β-雌二醇孵育细胞，通过定量实时聚合酶链反应可诱导PR-A和PR-B信使核糖核酸（mRNAs）随时间增加，通过免疫印迹和免疫荧光可诱导蛋白质增加。用PR配体（醋酸甲羟孕酮或Org-2058）孵育宫颈成纤维细胞可下调PR-A和PR-B水平。将细胞与PR配体加RU-486（一种PR拮抗剂）共同孵育，可部分消除激动剂诱导的受体下调。地塞米松，一种纯糖皮质激素，对PR表达没有抑制作用。这些结果表明，孕激素和雌激素调节宫颈成纤维细胞中的PR表达。我们推测，宫颈基质中PR表达的激素调节可能有助于功能性P(4)撤退以准备分娩。
