STEROID INITIATED EXOCYTOSIS IN HUMAN SPERM

类固醇引发人类精子的胞吐作用

• 批准号: 3323111
• 负责人: STANLEY MEIZEL
• 金额: $ 15.13万
• 依托单位: UNIVERSITY OF CALIFORNIA AT DAVIS
• 依托单位国家: 美国
• 财政年份: 1990
• 资助国家: 美国
• 起止时间: 1990-08-01 至 1995-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3323111
• 关键词: acrosome; adenosinetriphosphatase; calcium flux; electron microscopy; enzyme inhibitors; female; granulosa cell; hamsters; high performance liquid chromatography; hormone regulation /control mechanism; human subject; image processing; immunofluorescence technique; membrane activity; pinocytosis; progesterone; progesterone receptors; steroid hormone

The acrosome reaction (AR) is a central event of mammalian fertilization involving the fusion and fenestration of sperm head membranes. The molecular events that initiate this exocytotic process are not completely understood. The goal of this research is to increase our knowledge of those events in human sperm. These studies will be carried out with an in vitro human sperm incubation system. My laboratory has found that progesterone, a steroid hormone present in follicular fluid and secreted by granulosa cells and cells of the cumulus oophorus, can initiate the human sperm AR by increasing sperm [Ca2+]. This is of particular interest because: 1) sperm have to pass through the cumulus extracellular matrix during in vivo human fertilization; 2) the [Ca2+] increase is so fast (< 1 min) that a sperm steroid surface receptor may be involved. These studies will include: 1) whether steroids increase [Ca2+] in the human sperm head; 2) determination of the steroid structure necessary for the increase in [Ca2+] and the AR; 3) experiments to help determine whether or not there is a plasma membrane steroid receptor; 4) investigation of the possible role of steroid inhibition of Na+, K+ -ATPase and [Ca2+ + Mg2+] -ATPase in increasing sperm head [Ca2+] and thereby the AR. Methods to be used include: in vitro incubation of human sperm, computerized fluorescence image analysis, transmission electron microscopy,immunofluorescent assay of the AR, HPLC, (45)Ca-efflux studies and ATPase assays with (32)P-substrate. It is hoped that these studies will result in a greater understanding of the molecular basis of human fertilization and thereby lead in the future to new methods of contraception and of treatment for infertility. In addition, the increasing of intracellular [Ca2+] by a steroid via a cell surface-mediated mechanism might have relevance to Ca2+-requiring events in somatic cells. Thus, these studies may also be of importance outside the field of fertilization.

顶体反应（AR）是哺乳动物受精的核心事件 涉及精子头膜的融合和开窗。这 启动这种胞吐过程的分子事件并不完全 明白了。这项研究的目的是增加我们对这些方面的了解 人类精子中的事件。这些研究将在体外进行 人类精子孵化系统。我的实验室发现黄体酮 存在于卵泡液中并由颗粒细胞分泌的类固醇激素 和卵丘细胞，可以通过以下方式启动人类精子 AR： 增加精子[Ca2+]。这是特别令人感兴趣的，因为：1）精子 人体在体内过程中必须通过卵丘细胞外基质 施肥； 2) [Ca2+] 增加如此之快（< 1 分钟）以至于精子 类固醇表面受体可能参与其中。 这些研究将包括：1) 类固醇是否会增加体内的 [Ca2+] 人类精子头； 2) 确定所需的类固醇结构 [Ca2+] 和 AR 增加； 3）实验来帮助确定是否 或不存在质膜类固醇受体； 4）调查 类固醇抑制 Na+、K+ -ATP 酶和 [Ca2+ + Mg2+] 的可能作用 -ATP酶增加精子头部[Ca2+]，从而增加AR。 使用的方法包括：体外培养人类精子， 计算机荧光图像分析、透射电子 显微镜检查、AR 免疫荧光测定、 HPLC、(45)Ca 流出研究和 (32)P 底物的 ATP 酶测定。 希望这些研究能够加深人们对 人类受精的分子基础，从而引领未来 避孕和治疗不孕症的新方法。在 此外，类固醇通过细胞增加细胞内 [Ca2+] 表面介导的机制可能与 Ca2+ 需求事件有关 体细胞。因此，这些研究在外部也可能具有重要意义。 施肥领域。