Immature rat ovaries become revascularized rapidly after autotransplantation and show a gonadotropin-dependent increase in angiogenic factor gene expression.
Immature rat ovaries become revascularized rapidly after autotransplantation and show a gonadotropin-dependent increase in angiogenic factor gene expression.
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DOI：
10.1210/endo.134.3.8119153
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发表时间：
1994-03
期刊：
影响因子：
4.8
通讯作者：
G. A. Dissen;H. Lara;W. H. Fahrenbach;M. Costa;S. Ojeda
中科院分区：
文献类型：
--
作者：
G. A. Dissen;H. Lara;W. H. Fahrenbach;M. Costa;S. Ojeda
当23日龄幼鼠的卵巢被移植到异位部位时，它们在1周内通过类固醇负反馈恢复控制促性腺激素分泌的能力。血管腐蚀铸造扫描电镜显示，移植卵巢成为丰富的血管重建后48小时内移植。通过相应mRNA的RNA印迹杂交评估，血管向内生长伴随着编码两种血管生成因子（血管内皮生长因子（VEGF）和转化生长因子β 1（TGF β 1））的基因表达增加40- 60倍。虽然TGF β 3 mRNA水平也增加，但未观察到编码其他假定血管生成因子（如TGF α、碱性成纤维细胞生长因子和TGF β 2）的mRNA水平的变化。杂交组织化学结果显示，在完整卵巢中，VEGF mRNA主要表达于卵丘颗粒细胞和大腔卵泡的卵泡膜细胞。移植后，mRNA丰度增加，细胞定位发生显著变化，因此mRNA主要在卵巢外皮质细胞中表达。在完整的卵巢中，在膜间质细胞中检测到低水平的TGF β 1 mRNA;移植后，其表达在卵巢外皮质中也变得更加突出，但这种变化不像VEGF那样显著。由于卵巢自体移植后血清促性腺激素水平迅速升高，因此进行实验以确定这种升高在VEGF和TGF β 1基因表达活化中的重要性。移植后，用LHRH拮抗剂Nal-Glu LHRH（50微克/大鼠，每天一次，持续2天）处理一些动物，以防止移植后血清促性腺激素升高。48 h后通过RNA酶保护试验定量VEGF和TGF β 1 mRNA，结果表明，抑制促性腺激素分泌减少了VEGF和TGF β 1基因表达的增加。PMSG（8 IU/大鼠，单次注射）的伴随治疗主要绕过了内源性FSH水平的抑制，恢复了TGF β 1 mRNA反应，但对VEGF mRNA无影响。结果表明，卵巢移植后促性腺激素分泌的增加有助于通过上调两种主要血管生成因子的基因表达来促进移植物的血管重建。
When the ovaries of 23-day-old juvenile rats are transplanted to an ectopic site, they recover within 1 week the ability to control gonadotropin secretion via steroid negative feedback. Vascular corrosion casting followed by scanning electron microscopy revealed that the transplanted ovary becomes profusely revascularized within 48 h after transplantation. Vascular ingrowth was accompanied by a 40- to 60-fold increase in expression of the genes encoding two angiogenic factors, vascular endothelial growth factor (VEGF) and transforming growth factor-beta 1 (TGF beta 1), as assessed by RNA blot hybridization of the corresponding mRNAs. Although TGF beta 3 mRNA levels also increased, no changes in the levels of mRNAs encoding other putative angiogenic factors, such as TGF alpha, basic fibroblast growth factor, and TGF beta 2, were observed. Hybridization histochemistry demonstrated that in intact ovaries, VEGF mRNA is mainly expressed in granulosa cells of the cumulus oophorus and thecal cells of large antral follicles. Transplantation is followed by an increase in mRNA abundance and a dramatic shift in cellular localization, so that the mRNA becomes predominantly expressed in cells of the outer ovarian cortex. In intact ovaries, low levels of TGF beta 1 mRNA were detected in thecal-interstitial cells; after transplantation, its expression also became more predominant in the ovarian outer cortex, but this change was not as marked as in the case of VEGF. Because ovarian autotransplantation is followed by a rapid increase in serum gonadotropin levels, experiments were conducted to determine the importance of this rise in the activation of VEGF and TGF beta 1 gene expression. After transplantation, some animals were treated with the LHRH antagonist Nal-Glu LHRH (50 micrograms/rat, once a day for 2 days) to prevent the posttransplantation rise in serum gonadotropins. Quantitation of VEGF and TGF beta 1 mRNA by RNase protection assay 48 h later showed that suppression of gonadotropin secretion diminished the increase in both VEGF and TGF beta 1 gene expression. Concomitant treatment with PMSG (8 IU/rat, single injection), which mainly bypasses the suppression of endogenous FSH levels, restored the TGF beta 1 mRNA response, but had no effect on VEGF mRNA. The results suggest that the increase in gonadotropin secretion following ovarian transplantation contributes to revascularization of the graft by up-regulating the gene expression of two major angiogenic factors.