Sertoli Cell Mediated Engulfment of Apoptotic Germ Cells

支持细胞介导的凋亡生殖细胞的吞噬

• 批准号: 7900863
• 负责人: JEFFREY J LYSIAK
• 金额: $ 30.8万
• 依托单位: UNIVERSITY OF VIRGINIA
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-07-27 至 2011-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7900863
• 关键词: Address; Affect; Age; Animals; Apoptosis; Apoptotic; Autoimmune orchitis; BAI1 gene; Biochemical; Biological; Biology; Cells; Complex; Couples; Cytoskeleton; Development; Disease; Eating; Gene Silencing; Genes; Germ Cells; In Vitro; Infertility; Injury; Integral Membrane Protein; Knockout Mice; Lead; Link; Male Infertility; Malignant neoplasm of testis; Mediating; Medical; Modeling; Molecular; Necrosis; Pathology; Pathway interactions; Phagocytosis; Phosphatidylserines; Process; Reporting; Role; Secondary to; Signal Transduction; Signaling Protein; Spermatogenesis; System; Testing; Testis; Tissues; child bearing; in vivo; insight; male; novel strategies; postnatal; rac GTP-Binding Proteins; receptor; sertoli cell; spermatogenic epithelium structure

Spermatogenesis is a complex process where the proliferation/differentiation of germ cells is intimately tied to their apoptosis. How these germ cell corpses are cleared and how this engulfment process links to normal spermatogenesis, are poorly understood. Studies in other tissues have shown that corpse clearance is fundamentally important for normal development, and that failed clearance can lead to secondary necrosis of the apoptotic cells and tissue damage. Sertoli cells of testes are important in the engulfment of dying or dead germ cells. However, little is known about the molecules and mechanisms that govern Sertoli cell-mediated engulfment of apoptotic germ cells. Our overall hypothesis is that a set of molecules in Sertoli cells regulates the engulfment of apoptotic germ cells, and that disruption of this engulfment pathway will result in disruption of normal germ cell development in the testes. Here, we will rigorously address the biochemical and biological features of Sertoli cell-mediated germ cell engulfment in vitro and in vivo. We will pursue these studies with the combined expertise of the two PIs on this project, Jeff Lysiak with respect to spermatogenesis and germ cell apoptosis, and Kodi Ravichandran on apoptotic cell recognition and engulfment. We will test the biology of corpse clearance in the testes through the following specific aims. Our preliminary studies suggest the expression in Sertoli cells and a possible role in engulfment for the evolutionarily conserved signaling module composed of ELMO1, Dock180 and Rac proteins. In Aim 1 of this proposal we will use a combination of biochemical, functional and gene silencing studies to rigorously test the hypothesis that this signaling module is involved in Sertoli cell-mediated engulfment of apoptotic germ cells. In Aim 2, through Sertoli cell-specific deletion of engulfment genes using conditional knockout mice, we will attempt to disrupt germ cell corpse clearance in vivo. We will then address the importance of corpse clearance at different levels, including developmental apoptosis in the postnatal testis, injury models, and during spermatogenesis. Taken together, the combination of in vitro, in vivo, and whole animal studies tested here will provide key insights into mechanisms governing germ cell corpse clearance and yield a better understanding of this fundamentally important process for spermatogenesis.

精子发生是一个复杂的过程，其中生殖细胞的增殖/分化是 与细胞凋亡密切相关。这些生殖细胞尸体是如何被清除的， 与正常精子发生的联系，知之甚少。其他组织的研究 尸体清理对正常发育至关重要， 清除可导致凋亡细胞的继发性坏死和组织损伤。支持细胞 睾丸在吞噬垂死或死亡的生殖细胞方面很重要。然而，人们对此知之甚少。 控制支持细胞介导的凋亡生殖细胞吞噬的分子和机制。我们 总的假设是，支持细胞中的一组分子调节着 凋亡的生殖细胞，而这种吞噬途径的破坏将导致破坏 睾丸中正常生殖细胞发育的过程在这里，我们将严格解决生物化学 以及支持细胞介导的生殖细胞吞噬的生物学特性。我们将 在这个项目上，Jeff Lysiak与两位PI的专业知识相结合，继续进行这些研究。 在精子发生和生殖细胞凋亡方面，Kodi Ravichandran对凋亡细胞的影响 承认和吞噬。我们将测试睾丸中尸体清除的生物学， 具体目标。 我们的初步研究表明，在支持细胞的表达和吞噬的可能作用， 进化上保守的信号模块由ELMO 1、Dock 180和Rac蛋白组成。在 本建议的目的1我们将使用生物化学，功能和基因沉默研究的组合 为了严格检验这一信号模块参与支持细胞介导的 凋亡生殖细胞的吞噬。在目的2中，通过Sertoli细胞特异性缺失吞噬 基因使用条件敲除小鼠，我们将试图破坏生殖细胞尸体清除体内。 然后，我们将在不同层面上讨论尸体清理的重要性，包括发展 生后睾丸、损伤模型和精子发生过程中的细胞凋亡。综合起来， 结合体外，体内和整个动物研究，这里测试将提供关键的见解， 控制生殖细胞尸体清除的机制，并对此有更好的理解。 精子发生的重要过程。