Institute of Physiology, School of Medicine, National Yang-Ming University, Taipei, Taiwan.
J Cell Physiol. 2011 Jun;226(6):1608-19. doi: 10.1002/jcp.22491.
Angiogenesis occurs during ovarian follicle development and luteinization. Pituitary secreted FSH was reported to stimulate the expression of endothelial mitogen VEGF in granulosa cells. And, intraovarian cytokine transforming growth factor (TGF)β1 is known to facilitate FSH-induced differentiation of ovarian granulosa cells. This intrigues us to investigate the potential role of FSH and TGFβ1 regulation of granulosa cell function in relation to ovarian angiogenesis. Granulosa cells were isolated from gonadotropin-primed immature rats and treated once with FSH and/or TGFβ1 for 48 h, and the angiogenic potential of conditioned media (granulosa cell culture conditioned media; GCCM) was determined using an in vitro assay with aortic ring embedded in collagen gel and immunoblotting. FSH and TGFβ1 increased the secreted angiogenic activity in granulosa cells (FSH + TGFβ1 > FSH ≈ TGFβ1 >control) that was partly attributed to the increased secretion of pro-angiogenic factors VEGF and PDGF-B. This is further supported by the evidence that pre-treatment with inhibitor of VEGF receptor-2 (Ki8751) or PDGF receptor (AG1296) throughout or only during the first 2-day aortic ring culture period suppressed microvessel growth in GCCM-treated groups, and also inhibited the FSH + TGFβ1-GCCM-stimulated release of matrix remodeling-associated gelatinase activities. Interestingly, pre-treatment of AG1296 at late stage suppressed GCCM-induced microvessel growth and stability with demise of endothelial and mural cells. Together, we provide original findings that both FSH and TGFβ1 increased the secretion of VEGF and PDGF-B, and that in turn up-regulated the angiogenic activity in rat ovarian granulosa cells. This implicates that FSH and TGFβ1 play important roles in regulation of ovarian angiogenesis during follicle development.
血管生成发生在卵巢卵泡发育和黄体化过程中。据报道，垂体分泌的 FSH 可刺激颗粒细胞中内皮细胞有丝分裂原 VEGF 的表达。并且，已知卵巢内细胞因子转化生长因子 (TGF)β1 有助于 FSH 诱导卵巢颗粒细胞的分化。这引起了我们的兴趣，以研究 FSH 和 TGFβ1 对颗粒细胞功能的调节在卵巢血管生成中的潜在作用。将促性腺激素刺激的未成熟大鼠的颗粒细胞分离出来，并用 FSH 和/或 TGFβ1 处理一次 48 小时，并使用在胶原蛋白凝胶中嵌入主动脉环的体外测定法和免疫印迹法测定条件培养基（颗粒细胞培养条件培养基；GCCM）的血管生成潜力。FSH 和 TGFβ1 增加了颗粒细胞中分泌的血管生成活性（FSH+TGFβ1>FSH≈TGFβ1>对照），这部分归因于促血管生成因子 VEGF 和 PDGF-B 的分泌增加。这进一步得到了以下证据的支持：在整个主动脉环培养期间或仅在前 2 天用 VEGF 受体-2（Ki8751）或 PDGF 受体（AG1296）抑制剂预处理抑制了 GCCM 处理组中小血管的生长，并且还抑制了 FSH+TGFβ1-GCCM 刺激的基质重塑相关明胶酶活性的释放。有趣的是，在晚期用 AG1296 预处理可抑制 GCCM 诱导的微血管生长和稳定性，内皮细胞和壁细胞死亡。总之，我们提供了原始发现，即 FSH 和 TGFβ1 均可增加 VEGF 和 PDGF-B 的分泌，进而上调大鼠卵巢颗粒细胞的血管生成活性。这表明 FSH 和 TGFβ1 在卵泡发育过程中卵巢血管生成的调节中起重要作用。
