Physiological Role of Theca-Granulosa Cell Interactions in Controlling Ovarian Follicular Development and Atresia

1.我们研究了卵泡膜和颗粒细胞相互作用在牛卵巢卵泡发育过程中控制卵泡成熟和闭锁的可能作用，使用了一种共培养系统，其中颗粒细胞和卵泡膜细胞生长在胶原膜的相对两侧。我们已经演示了以下facs。(1)颗粒细胞-卵泡膜细胞相互作用是控制卵泡细胞分化的主要卵泡成分;卵泡膜细胞分泌抑制未成熟颗粒细胞分化的因子，同时促进成熟颗粒细胞的分化，并且在整个卵泡成熟过程中，颗粒细胞分泌促进卵泡膜细胞分化和生长的因子。(2)这些因子控制颗粒细胞的凋亡，在卵泡发育的早期和晚期抑制颗粒细胞的凋亡。随着卵泡的生长，颗粒细胞对凋亡的敏感性降低.在第二系列研究中，我们用SV 40 DNA、Ha-ras癌基因和p53温度敏感突变体（p53-val 135）三重转染建立了人颗粒细胞系。使用该细胞系（HO-23），证实了糖皮质激素和细胞外基质（ECM）促进P4的产生，而bFGF和佛波醇酯TPA抑制P4的产生;糖皮质激素、ECM和bFGF抑制p53诱导的HO-23细胞凋亡，而TPA促进其凋亡;

1. We have investigated the possible role of theca and granulosa cell interaction in the control of follicular maturation and atresia during bovine ovarian follicular developmentusng a co-culture system in which granulosa and theca cells were grown on oppositesides of a collagen membrane. We have already demonstrated the following facs.(1) Granulosa-theca cell interaction is a major follicular constituent in the control of follicular cell differentiation; theca cells secrete factor(s) inhibiting the differentiation of the immature granulosa cells while promoting that of the matured ones and that granulosa cells secrete factor(s) promoting both the differentiation and growth of thecacells throughout the follicular maturation process.(2) Thecal factor(s) control the apoptosis of granulosa cells; inhibit the apoptosis of granulosa cells at the early and late stage of follicular development. Susceptibility of granulosa cells to apoptosis decreases as follicles grow.2. In the second series of the study, we established human granulosa cell lines by triply transfected with SV40 DNA, Ha-ras oncogene and the temperature sensitive mutant of p53(p53-val135). Using this cell-line (HO-23), it was confirmed that glucocorticoids and extracellular matrix(ECM) enhanced P4 production while bFGF and phorbol ester TPA suppressed it, that glucocorticoids, ECM and bFGF inhibited p53-induced apoptosis of HO-23 cells while TPA enhanced it, and that apoptosis at early stage does not interrupt steroidogenesis.