El Ramy R, Verot A, Mazaud S, Odet F, Magre S, Le Magueresse-Battistoni B
Inserm U418/INRA UMR 1245, Hôpital Debrousse, 29 rue soeur Bouvier, 69322 Lyon cedex 05, France.
J Endocrinol. 2005 Oct;187(1):135-47. doi: 10.1677/joe.1.06146.
The role of fibroblast growth factor (FGF) 2 and FGF9 as mediators of cell-cell interactions between Sertoli cells (SCs) and peritubular cells (PCs) was investigated. Using RT-PCR, we demonstrated that SCs and PCs recovered from 20-day-old rats expressed several of the seven FGF receptors (FGFRs), and more specifically the FGFR1 IIIc. FGF2 and FGF9 did not elicit any morphological changes in primary cultures of SCs, nor did they alter the number of SCs in culture. By contrast, changes in shape were observed in FGF2- and FGF9-treated PCs. In addition, FGF2 but not FGF9 enhanced significantly and dose-dependently the number of PCs in culture, indicating that FGF2 was a survival factor for these cells. It was also mitogenic because it enhanced the [3H]thymidine labeling index in PCs. We next examined the effects of FGF2 and FGF9 in a coculture system using 20-day-old rat SCs and PCs, and in an organotypic culture system using XY rat embryonic gonads. In both models, FGF2 and FGF9 were found to promote cellular interactions as evidenced by the extent of cellular reorganization in the coculture system, and cord morphogenesis and growth in the organotypic culture system. A key feature in SC-PC interactions is the synthesis and remodeling of the basement membrane which is co-elaborated by the two cell types. Since basement membrane homeostasis depends upon the coordinated activity of proteinases and inhibitors, the proteinases and inhibitors produced by PCs and SCs degrading or opposing degradation of the major components of the basement membrane were further studied. Specifically, we monitored the metalloproteinases (MMP)-2 and -9 and the tissue inhibitors -1, -2 and -3, the plasminogen activators (PAs) and the PA inhibitor-1, using zymography for the proteinases and Western blots for the cognate inhibitors. Cocultures received FGF or an analog of cAMP in order to prevent cellular reorganization. We found that FGF2 was unique in inducing MMP-9 in coculture. Also, the enhanced levels of the PA inhibitor-1 and the 30 kDa band glycosylated form of tissue inhibitor-3 correlated with the enhanced SC-PC reorganization. It was concluded that FGF2 and FGF9 are morphogens for the formation of testicular cords.
研究了成纤维细胞生长因子（FGF）2和FGF9作为支持细胞（SCs）与睾丸周细胞（PCs）之间细胞间相互作用介质的作用。利用逆转录聚合酶链反应（RT-PCR），我们证明从20日龄大鼠分离得到的SCs和PCs表达七种FGF受体（FGFRs）中的几种，更具体地说是FGFR1 IIIc。FGF2和FGF9在SCs原代培养中未引起任何形态学变化，也未改变培养的SCs数量。相比之下，在FGF2和FGF9处理的PCs中观察到了形态变化。此外，FGF2而非FGF9显著且剂量依赖性地增加了培养的PCs数量，表明FGF2是这些细胞的存活因子。它也是有丝分裂原，因为它提高了PCs中的[3H]胸苷标记指数。接下来，我们在使用20日龄大鼠SCs和PCs的共培养系统以及使用XY大鼠胚胎性腺的器官型培养系统中研究了FGF2和FGF9的作用。在这两种模型中，FGF2和FGF9均被发现可促进细胞间相互作用，共培养系统中的细胞重组程度以及器官型培养系统中的索状形态发生和生长均证明了这一点。SCs与PCs相互作用的一个关键特征是由这两种细胞共同形成的基底膜的合成与重塑。由于基底膜稳态取决于蛋白酶和抑制剂的协同活性，因此进一步研究了PCs和SCs产生的降解或对抗基底膜主要成分降解的蛋白酶和抑制剂。具体而言，我们使用蛋白酶的酶谱分析和同源抑制剂的蛋白质印迹法监测了金属蛋白酶（MMP）-2和-9以及组织抑制剂-1、-2和-3、纤溶酶原激活剂（PAs）和PA抑制剂-1。共培养物接受FGF或cAMP类似物以防止细胞重组。我们发现FGF2在共培养中诱导MMP-9方面具有独特性。此外，PA抑制剂-1水平的升高以及组织抑制剂-3的30 kDa糖基化形式条带与SCs-PCs重组的增强相关。得出的结论是，FGF2和FGF9是睾丸索形成的形态发生素。
