Tucci J, Beck F
Howard Florey Institute of Experimental Physiology and Medicine, University of Melbourne, Parkville, Victoria, Australia.
J Reprod Fertil. 1998 Jan;112(1):1-10. doi: 10.1530/jrf.0.1120001.
The interaction between parathyroid hormone-related protein (PTHrP) and the parathyroid hormone (PTH)/PTHrP receptor is thought to play a role in the growth and differentiation of various tissues throughout fetal development in the rodent. The aim of the present study was to define the patterns of expression of PTHrP and of the PTH/PTHrP receptor in the rat uterus during the early stages of normal pregnancy, and following artificial induction of a decidual reaction. Using hybridization histochemistry, we have shown that the receptor gene is switched on early in pregnancy (by 1.5 days post coitum) in the endometrial stromal cells that surround the lumen. These cells include the anti-mesometrial subepithelial stromal cells that are destined to become decidualized. This pattern continues until 5.0 days post coitum, when PTHrP is switched on in antimesometrial luminal epithelial cells that line the implantation chamber. Stromal cells underlying the implantation chamber then downregulate transcription of the receptor gene, and within 12 h differentiate into decidual cells. A similar pattern was seen in uteri in which a decidual reaction had been induced artificially. Therefore, it may be postulated that in early pregnancy the endometrial stroma initiates transcription of the gene for the PTH/PTHrP receptor and is thus 'primed' for the PTHrP signal from the luminal epithelial cells. Some time after receiving the signal, the endometrial stromal cells downregulate the receptor gene, and this appears to be a trigger for the terminal differentiation of the stromal cells into decidual cells. These results suggest that PTHrP, acting through the PTH/PTHrP receptor, plays a role in the initiation of a decidual reaction during early pregnancy by regulating the differentiation of endometrial stromal cells into decidual cells.
甲状旁腺激素相关蛋白（PTHrP）与甲状旁腺激素（PTH）/PTHrP受体之间的相互作用被认为在啮齿动物胎儿发育过程中各种组织的生长和分化中发挥作用。本研究的目的是确定正常妊娠早期以及人工诱导蜕膜反应后大鼠子宫中PTHrP和PTH/PTHrP受体的表达模式。使用杂交组织化学，我们发现受体基因在妊娠早期（交配后1.5天）在围绕管腔的子宫内膜基质细胞中开启。这些细胞包括注定会蜕膜化的反系膜上皮下基质细胞。这种模式一直持续到交配后5.0天，此时PTHrP在植入腔衬里的反系膜腔上皮细胞中开启。植入腔下方的基质细胞随后下调受体基因的转录，并在12小时内分化为蜕膜细胞。在人工诱导蜕膜反应的子宫中也观察到类似的模式。因此，可以推测在妊娠早期，子宫内膜基质启动PTH/PTHrP受体基因的转录，从而为来自腔上皮细胞的PTHrP信号做好“准备”。在接收到信号后的一段时间，子宫内膜基质细胞下调受体基因，这似乎是基质细胞终末分化为蜕膜细胞的触发因素。这些结果表明，PTHrP通过PTH/PTHrP受体发挥作用，在妊娠早期通过调节子宫内膜基质细胞向蜕膜细胞的分化，在蜕膜反应的启动中发挥作用。
