权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

Mechanism of apoptosis induction in amphibian spermatogonia by prolactin

催乳素诱导两栖动物精原细胞凋亡的机制

基本信息

批准号：
09480206
负责人：
ABE Shin-ichi
金额：
$ 8.06万
依托单位：
Kumamoto University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
1997
资助国家：
日本
起止时间：
1997 至 1999
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-09480206/
关键词：
newt spermatogonia meiosis initiation apoptosis prolactin FSH cycloheximide checkpoint プロラクチン受容体 RT-PCR FSH受容体

项目摘要

We have investigated about the mechanism of apoptosis induction in newt spermatogonia by prolactin. We clarified the following things.(1) Ovine prolactin (oPRL) administration into newts induced apoptotic cell death only in the last stage of spermatogonia (7th generation from primary spermatogonium) and co-administration of porcine follicle-stimulating hormone (pFSH) inhibited this cell death. In organ culture of testes fragments, it was demonstrated that PRL induces spermatogonial cell death by acting directly on the testis.(2) Transfer of newts to low temperature caused spermatogonial apoptosis and elevation of plasma PRL levels. Injection of anti-PRL serum into newt at low temperature almost completely rescued spermatogonia from degeneration for as long as 3 days. These results demonstrate that low temperature caused elevation of prolactin concentration in the newt blood, which induced cell death of spermatogonia just before meiosis.(3) Cycloheximide (CHX), a protein synthesis inhibitor, also induced apoptosis. zVAD -fmk, a broad caspase inhibitor, inhibited the apoptosis induced by PRL and CHX. On the other hand, these parameters were not suppressed by ICE inhibitor Ac-YVAD-CHO or by caspase-3 inhibitor Ac-DEVD-CHO, indicating that apoptotic morphological changes occurring when the 7th generation of spermatogonia dies are induced by some unknown caspases. We have isolated cDNA for newt caspase 3.(4) FSH activity is indispensable for accomplishment of the last mitosis of newt spermatogonia, because cell death of secondary spermatogonia just before meiosis occurred without pFSH in vitro. These results indicate that balance of the biological activity of PRL and FSH is the key factor for life-or-death of the last stage of spermatogonia and for decision whether spermatocytogenesis commence or not.

本研究探讨了催乳素诱导蝾螈精原细胞凋亡的机制。我们澄清了以下几点。(1)绵羊催乳素（oPRL）管理到蝾螈诱导凋亡细胞死亡，仅在最后阶段的精原细胞（第7代初级精原细胞）和共同管理的猪卵泡刺激素（pFSH）抑制这种细胞死亡。在睾丸碎片的器官培养中，证明PRL通过直接作用于睾丸而诱导精原细胞死亡。(2)蝾螈转移到低温引起精原细胞凋亡和血浆PRL水平升高。注射抗PRL血清在低温下几乎完全拯救蝾螈精原细胞的退化长达3天。这些结果表明，低温引起蝾螈血液中催乳素浓度的升高，从而诱导精原细胞减数分裂前的细胞死亡。(3)蛋白质合成抑制剂环己酰亚胺（CHX）也可诱导细胞凋亡。广泛的caspase抑制剂zVAD -fastin可抑制PRL和CHX诱导的细胞凋亡。ICE抑制剂Ac-YVAD-CHO和caspase-3抑制剂Ac-DEVD-CHO均不能抑制这些参数，提示第7代精原细胞死亡时发生的凋亡形态学变化是由一些未知的caspase诱导的。我们已经分离出蝾螈胱天蛋白酶3的cDNA。(4)FSH活性是蝾螈精原细胞完成最后一次有丝分裂所必需的，因为在体外没有pFSH的情况下，次级精原细胞在减数分裂前会发生细胞死亡。结果表明，PRL和FSH生物活性的平衡是决定精原细胞后期生死和精母细胞发生是否开始的关键因素。