Takeyama J, Suzuki T, Hirasawa G, Muramatsu Y, Nagura H, Iinuma K, Nakamura J, Kimura K I, Yoshihama M, Harada N, Andersson S, Sasano H
Department of Pathology, Tohoku University School of Medicine, Sendai, Miyagi, Japan.
J Clin Endocrinol Metab. 2000 Jan;85(1):410-6. doi: 10.1210/jcem.85.1.6323.
The present study investigates the expression patterns of 17beta-hydroxysteroid dehydrogenase (17betaHSD) isozymes in human fetal tissues to understand how estrogenic activity is regulated in the human fetus. Using enzyme assay, high 17betaHSD activity was detected in the placenta and liver, and low levels of 17betaHSD activity were also present in the gastrointestinal tract and kidney. After Northern blot analysis, we detected the messenger ribonucleic acid for 17betaHSD type 1 (17betaHSD1) only in the placenta, whereas that for 17betaHSD type 2 (17betaHSD2) was detected in the placenta, liver, gastrointestinal tract, and urinary tract at 20 gestational weeks. In RT-PCR analysis of the messenger ribonucleic acid transcripts, 17betaHSD 1 was predominantly expressed in the placenta, brain, heart, lung, and adrenal, whereas 17betaHSD2 expression was predominantly detected in the liver, gastrointestinal tract, and kidney. In addition, we detected 17betaHSD2 immunoreactive protein in surface epithelial cells of the stomach, absorptive epithelial cells of the small intestine and colon, hepatocytes of the liver, and interstitial cells surrounding the urinary tubules of the renal medulla. 17betaHSD2 in these tissues may be functioning in the prevention of in utero exposure of the fetus to excessive estradiol from the maternal circulation and amniotic fluids.
本研究调查了17β-羟基类固醇脱氢酶（17βHSD）同工酶在人胎儿组织中的表达模式，以了解人胎儿中雌激素活性是如何调节的。通过酶活性测定，在胎盘和肝脏中检测到高17βHSD活性，在胃肠道和肾脏中也存在低水平的17βHSD活性。经过Northern印迹分析，我们仅在胎盘中检测到17βHSD 1型（17βHSD1）的信使核糖核酸，而在妊娠20周时，在胎盘、肝脏、胃肠道和泌尿道中检测到17βHSD 2型（17βHSD2）的信使核糖核酸。在信使核糖核酸转录本的逆转录-聚合酶链反应（RT-PCR）分析中，17βHSD 1主要在胎盘、脑、心脏、肺和肾上腺中表达，而17βHSD2表达主要在肝脏、胃肠道和肾脏中检测到。此外，我们在胃的表面上皮细胞、小肠和结肠的吸收上皮细胞、肝脏的肝细胞以及肾髓质肾小管周围的间质细胞中检测到17βHSD2免疫反应蛋白。这些组织中的17βHSD2可能在防止胎儿在子宫内暴露于来自母体循环和羊水的过量雌二醇方面发挥作用。
