Epidermal growth factor inhibits large granulosa cell apoptosis by stimulating progesterone synthesis and regulating the distribution of intracellular free calcium.
Epidermal growth factor inhibits large granulosa cell apoptosis by stimulating progesterone synthesis and regulating the distribution of intracellular free calcium.
复制标题
DOI：
10.1095/biolreprod51.4.646
复制
发表时间：
1994-10
影响因子：
3.6
通讯作者：
A. M. Luciano;A. Pappalardo;C. Ray;J. Peluso
中科院分区：
文献类型：
--
作者：
A. M. Luciano;A. Pappalardo;C. Ray;J. Peluso
最初的研究旨在确定是否所有颗粒细胞(GC)在体外都会发生凋亡。从未成熟的大鼠卵巢分离GCs，用15-45%Percoll梯度分离。收集了12个组分，并根据大小将GC合并：小GC(约50亩2；组分2-5)和大GC(>；or=75亩2；组分6-8)。无血清培养24 h后，70-80%的大GCs内可见DNA片断3‘端原位末端标记的片段化DNA。同样，原位DNA染色显示，至少50%的大型GC有凋亡细胞核。这些DNA变性改变在5%的小GC内观察到。这些研究表明，在无血清培养中，大多数大GC在24小时内通过凋亡机制死亡。随后的研究集中在表皮生长因子(EGF)抑制大GC凋亡的机制上。EGF使大的GCs的核凋亡率从对照组的47+/-1%降低到18+/-2%(p<；0.05)。EGF还增加了大GCs的孕酮(P4)分泌(对照组为6.3+/-0.7，EGF组为18.7+/-1.0 ng/ml；p<；0.05)。P4模拟EGF对细胞凋亡的影响，P4拮抗剂RU 486和P4合成抑制剂氨基谷氨酰亚胺(AG)可减弱EGF对细胞凋亡的影响。AG的作用被P4所取代。因此，EGF通过刺激P4的合成来减少大的GC细胞的凋亡，而P4通过其受体介导其作用。
The initial study was designed to determine whether all granulosa cells (GCs) undergo apoptosis in vitro. GCs were isolated from immature rat ovaries and separated on a 15-45% Percoll gradient. Twelve fractions were collected, and GCs were pooled according to size: small GCs (approximately 50 mu 2; fractions 2-5) and large GCs (> or = 75 mu 2; fractions 6-8). GCs were cultured in serum-free medium for 24 h. After 24 h of culture, fragmented DNA, detected by in situ end labeling of the 3'OH ends of DNA fragments, was observed within 70-80% of large GCs. Similarly, in situ DNA staining demonstrated that at least 50% of large GCs possessed apoptotic nuclei. These degenerative changes in DNA were observed within < or = 5% of small GCs. These studies demonstrate that in serum-free medium, most large GCs die via an apoptotic mechanism within 24 h. Subsequent studies focused on the mechanism by which epidermal growth factor (EGF) inhibits large GC apoptosis. EGF reduced the percentage of large GCs with apoptotic nuclei from 47 +/- 1% for controls to 18 +/- 2% (p < 0.05). EGF also increased progesterone (P4) secretion from large GCs (6.3 +/- 0.7 for controls vs. 18.7 +/- 1.0 ng/ml for EGF treatment; p < 0.05). The effect of EGF on apoptosis was mimicked by P4 and attenuated by the P4 antagonist, RU 486, and aminoglutethimide (AG), an inhibitor of P4 synthesis. The effect of AG was overridden by P4. Therefore, EGF reduces large GC apoptosis by stimulating P4 synthesis, with P4 mediating its action through its receptor.(ABSTRACT TRUNCATED AT 250 WORDS)