Sertoli Cell Mediated Engulfment of Apoptotic Germ Cells

精子发生是一个复杂的过程，生殖细胞的增殖/分化 与它们的细胞凋亡密切相关。这些生殖细胞身体是如何被清除的，以及这种吞噬是如何 与正常精子发生有关的过程，人们知之甚少。在其他组织中的研究已经 表明身体清理对正常发育至关重要，但失败了 清除可导致继发性坏死的凋亡细胞和组织损伤。Sertoli细胞 睾丸在吞噬垂死或死亡的生殖细胞的过程中起着重要作用。然而，人们对此知之甚少 控制支持细胞介导的吞噬凋亡生殖细胞的分子和机制。我们的 总体假设是支持细胞中的一组分子调节吞噬 生殖细胞凋亡，而这一吞噬途径的破坏将导致破坏 睾丸内正常的生殖细胞发育。在这里，我们将严谨地阐述生化 支持细胞介导的生殖细胞吞噬的体内外生物学特性。我们会 利用两个PI在该项目上的组合专业知识进行这些研究，Jeff Lysiak与 Kodi Ravichandran对精子发生和生殖细胞凋亡的影响 承认和吞没。我们将测试在睾丸中清除身体的生物学 遵循特定的目标。 我们的初步研究表明，该基因在支持细胞中表达，并可能在吞噬过程中发挥作用。 进化上保守的信号模块由ELMO1、Dock180和Rac蛋白组成。在……里面 这项建议的目标1我们将结合生化、功能和基因沉默研究 为了严格测试这个信号模块参与支持细胞介导的假设 吞噬了凋亡的生殖细胞。在目标2中，通过Sertoli细胞特异性删除包裹体 利用条件性基因敲除小鼠，我们将试图扰乱体内生殖细胞身体的清除。 然后，我们将在不同的层面上解决身体清理的重要性，包括发展 出生后睾丸、损伤模型和精子发生过程中的细胞凋亡。总而言之， 在这里测试的体外、体内和整体动物研究的结合将提供对 生殖细胞身体清除的机制，并对此有更好的理解 对精子发生至关重要的过程。

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.