CAMP-MEDIATED SIGNALS AS DETERMINANTS FOR APOPTOSIS IN PRIMARY GRANULOSA-CELLS
CAMP-MEDIATED SIGNALS AS DETERMINANTS FOR APOPTOSIS IN PRIMARY GRANULOSA-CELLS
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DOI：
10.1006/excr.1995.1156
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发表时间：
1995-05-01
影响因子：
3.7
通讯作者：
AMSTERDAM, A
中科院分区：
文献类型：
--
作者：
AHARONI, D;DANTES, A;AMSTERDAM, A
促性腺营养激素和其他物质诱导颗粒细胞的分化和黄体化，从而升高细胞内循环AMP（CAMP）的物质。我们已经研究了这些物质增强类固醇生成的效力与诱导从大鼠前卵泡获得的原代颗粒细胞培养物中凋亡的相关性，营地类似物，8- BR CAMP诱导了超过90％的细胞种群的凋亡。在无血清培养基中的37摄氏度，这些细胞的生理兴奋剂，卵泡刺激激素（FSH）和黄体生成激素（LH）的生理兴奋剂（LH）中，在37摄氏度的37度中孵育15小时，这引起了这些细胞中等的cAMP反应，然后是脱敏周期，相反，对细胞死亡的产生增加了四倍，对细胞死亡没有明显的影响，福斯科蛋白是一种有效的腺苷酸环化酶激活剂，通过比贡献激素刺激大的数量级刺激了cAMP和类固醇生成的反应，并同意地增加了。细胞死亡（25％）。此外，通过异丁基甲基黄嘌呤（IBMX）阻断了福斯科蛋白刺激细胞中细胞磷酸二酯酶的活性，该细胞（IBMX）维持高水平的细胞内cAMP，导致孵育40小时后的细胞死亡进一步增强（50％），碱性成纤维细胞生长因子（BFGGF）（BFGGF） ）和促性腺激素释放激素（GNRH），它们以cAMP无关的方式刺激了这些细胞中的类固醇生成，并未促进细胞死亡，此外，与福斯科林和BFGF一起对细胞进行了刺激，导致了相对降低的相对相对相对相对率的降低。为了检查肿瘤抑制基因的表达是否与CAMP诱导的颗粒细胞分化和凋亡有关，我们检查了SV40中CAMP转化的颗粒细胞的作用，预计T-抗原表达会阻止T-抗原的表达p53以及视网膜母细胞瘤基因产物（PRB）及其相关蛋白的活性，SV40转化建立的三种不同细胞系的培养物表现出对8-BR-cAMP或Forskolin Plus IBMS诱导的凋亡的抗性，相比之下原代细胞中严重的凋亡反应，我们建议通过高水平的cAMP催化刺激原代颗粒细胞，而通过促性腺激素激素刺激细胞的刺激，导致中度cAMP反应，随后降低了降温，以进一步刺激，可以进一步刺激。此外，延长黄叶藻细胞的寿命，一个或多个抑制肿瘤蛋白可能会介导cAMP产生的信号，导致细胞死亡。 （c）1995 Academic Press，Inc。
Differentiation and luteinization of granulosa cells are induced by gonadotrophic hormones and other substances elevating intracellular levels of cyclic AMP (cAMP). We have investigated the correlation between the potency of these substances to enhance steroidogenesis and to induce apoptosis in primary granulosa cell cultures obtained from rat preovulatory follicles, The cAMP analog, 8-Br cAMP, induced apoptosis in more than 90% of the cell population within 15 h of incubation at 37 degrees C in serum-free medium, The physiological stimulants of these cells, follicle-stimulating hormone (FSH) and luteinizing hormone (LH), which caused a moderate cAMP response in these cells, followed by a desensitization period, increased progesterone production by fourfold with no apparent effect on cell death, In contrast, forskolin, a potent activator of adenylate cyclase, stimulated both the cAMP and steroidogenic response by an order of magnitude greater than the gonadotropin stimulation, concomitantly with a pronounced increase in cell death (25%). Moreover, blocking of the cellular phosphodiesterase activity in forskolin-stimulated cells by isobutylmethylxanthine (IBMX), which maintains high levels of intracellular cAMP, led to further enhancement of cell death following 40 h of incubation (50%), Basic fibroblast growth factor (bFGF) and gonadotropin-releasing hormone (GnRH), which stimulated steroidogenesis in these cells in a cAMP-independent manner, did not promote cell death, Moreover, costimulation of the cells with forskolin and bFGF led to a substantial decrease in the incidence of apoptosis relative to forskolin alone, In order to examine whether the expression of tumor suppressor genes is involved in granulosa cell differentiation and apoptosis induced by cAMP, we examined the effect of cAMP in SV40 transformed granulosa cells, in which T-antigen expression is expected to block the activity of p53 as well as of the retinoblastoma gene product (pRB) and its related proteins, Cultures of three different cell lines established by SV40 transformation demonstrated resistance to 8-Br-cAMP- or forskolin plus IBMS-induced apoptosis, in contrast to the severe apoptotic response in primary cells, We suggest that stimulation of primary granulosa cells by high levels of cAMP catalyzes programmed cell death, while stimulation of the cells by gonadotropic hormones, which result in a moderate cAMP response, followed by desensitization to further stimulation, can prolong the lifespan of the luteinized granulosa cells, Moreover, one or more tumor suppressor proteins may mediate the cAMP generated signal leading to cell death. (C) 1995 Academic Press, Inc.