Chegini N, Rong H, Dou Q, Kipersztok S, Williams R S
Department of Obstetrics and Gynecology, University of Florida College of Medicine, Gainesville 32610, USA.
J Clin Endocrinol Metab. 1996 Sep;81(9):3215-21. doi: 10.1210/jcem.81.9.8784072.
The objective of the present study was to determine whether GnRH and GnRH receptor are expressed in myometrium and leiomyomata, and if GnRH analogs alone or in the presence of ovarian steroids can modulate the rate of DNA synthesis, proliferation, and transforming growth factor-beta 1 (TGF beta 1) production in myometrial smooth muscle cells in vitro. Reverse transcription-PCR revealed that leiomyomata, unaffected myometrium, and isolated myometrial smooth muscle cells express GnRH and GnRH receptor messenger ribonucleic acid. Furthermore, in a dose-dependent manner, GnRH agonist (leuprolide acetate) inhibited, but GnRH antagonist [D-pGlu1,D-Phe2,D-Trp3.6] (GnRH-Ant1) stimulated, the rate of [3H]thymidine incorporation into myometrial smooth muscle cells (P < 0.05), whereas GnRH-Ant2 (Ac-D-P-Cl-Phe1.2,D-Trp3,D-Arg6,D-Ala10) had no effect. 17 beta-Estradiol (E2) medroxyprogesterone acetate (MPA), and E2 plus MPA (1 micromol/L) stimulated the rate of DNA synthesis by smooth muscle cells (P < 0.05), which was inhibited by GnRH analogs used at 5 micromol/L (P < 0.05). GnRH analogs had no significant effect on myometrial smooth muscle cell proliferation, with the exception of GnRH-Ant1; however, they inhibited the stimulatory action of E2, MPA, and E2 plus MPA in a time-dependent manner (P < 0.05). These cells also synthesized and released approximately 1.32 +/- 0.02 ng/mL total (active plus latent) TGF beta 1, of which 0.73 +/- 0.02 ng/mL was in an active form. E2, MPA, E2 plus MPA, and GnRH analog treatments resulted in an increase in total TGF beta 1 production, whereas GnRH agonist and GnRH-Ant2, but not GnRH-An1, inhibited active TGF beta 1 (P < 0.05). GnRH analogs also inhibited the action of E2 plus MPA on total and active TGF beta 1 production, whereas GnRH-Ant1 further stimulated E2, MPA, or E2 plus MPA action on active TGF beta 1 production (P < 0.05). The data demonstrate for the first time that GnRH and GnRH receptor messenger ribonucleic acid are expressed in myometrium, leiomyomata, and myometrial smooth muscle cells. The local expression of GnRH and receptor along with the direct action of GnRH analogs on the smooth muscle cell DNA synthesis and TGF beta 1 production suggest an autocrine/paracrine role for GnRH in these tissues, a mechanism that may be involved in leiomyomata regression in women receiving GnRH agonist therapy.
本研究的目的是确定促性腺激素释放激素（GnRH）及其受体是否在子宫肌层和平滑肌瘤中表达，以及单独使用GnRH类似物或在卵巢甾体激素存在的情况下，是否能在体外调节子宫肌层平滑肌细胞的DNA合成速率、增殖以及转化生长因子-β1（TGF-β1）的产生。逆转录聚合酶链反应（RT-PCR）显示，平滑肌瘤、未受影响的子宫肌层以及分离出的子宫肌层平滑肌细胞均表达GnRH及其受体信使核糖核酸。此外，GnRH激动剂（醋酸亮丙瑞林）以剂量依赖的方式抑制了[3H]胸腺嘧啶核苷掺入子宫肌层平滑肌细胞的速率（P<0.05），而GnRH拮抗剂[D-pGlu1,D-Phe2,D-Trp3.6]（GnRH-Ant1）则刺激了该速率（P<0.05），而GnRH-Ant2（Ac-D-P-Cl-Phe1.2,D-Trp3,D-Arg6,D-Ala10）则无作用。17β-雌二醇（E2）、醋酸甲羟孕酮（MPA）以及E2加MPA（1μmol/L）刺激了平滑肌细胞的DNA合成速率（P<0.05），而5μmol/L的GnRH类似物则抑制了该速率（P<0.05）。除GnRH-Ant1外，GnRH类似物对子宫肌层平滑肌细胞增殖无显著影响；然而，它们以时间依赖的方式抑制了E2、MPA以及E2加MPA的刺激作用（P<0.05）。这些细胞还合成并释放了约1.32±0.02 ng/mL的总（活性加潜伏性）TGF-β1，其中0.73±0.02 ng/mL为活性形式。E2、MPA、E2加MPA以及GnRH类似物处理导致总TGF-β1产生增加，而GnRH激动剂和GnRH-Ant2（而非GnRH-Ant1）抑制了活性TGF-β1（P<0.05）。GnRH类似物还抑制了E2加MPA对总TGF-β1和活性TGF-β1产生的作用，而GnRH-Ant1则进一步刺激了E2、MPA或E2加MPA对活性TGF-β1产生的作用（P<0.05）。数据首次证明，GnRH及其受体信使核糖核酸在子宫肌层、平滑肌瘤以及子宫肌层平滑肌细胞中表达。GnRH及其受体的局部表达以及GnRH类似物对平滑肌细胞DNA合成和TGF-β1产生的直接作用表明，GnRH在这些组织中具有自分泌/旁分泌作用，这一机制可能参与了接受GnRH激动剂治疗的女性平滑肌瘤的消退过程。
