Regulation of apoptosis in a colonial urochordate

集落尾索动物细胞凋亡的调节

• 批准号: 6596851
• 负责人: ROBERT J LAUZON
• 金额: $ 13.22万
• 依托单位: UNION COLLEGE
• 依托单位国家: 美国
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-07-01 至 2007-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6596851
• 关键词: Tunicata; apoptosis; bioperiodicity; cell cell interaction; cell growth regulation; cell migration; cysteine endopeptidases; cytochrome c; developmental genetics; enzyme activity; fluorescent dye /probe; gene expression; genetic mapping; growth /development; immunocytochemistry; immunologic assay /test; life cycle; mitochondria; phagocytes; phagocytosis; phosphatidylserines; polymerase chain reaction; protein localization; regeneration

DESCRIPTION (provided by applicant): Cell death is an essential aspect in the life of a multicellular animal, playing an integral role in cell turnover, embryonic development, and responses to environmental stress. The long term objective of this proposal is to gain an understanding of the molecular basis by which programmed cell death (PCD) and programmed cell removal are regulated in a unique model system, the colonial urochordate Botryllus schlosseri, and how these processes are counterbalanced with stern cell-derived organismal regeneration. In this animal, PCD occurs in cyclical fashion every week, during which all adult individuals in a colony die synchronously by apoptosis within 24 hours. During this period, cell corpses from adult tissues are engulfed by circulating phagocytic cells, and a new asexual generation of adults simultaneously replaces the old one as it is resorbed. The proposed studies will initially seek to identify components of the cell death machinery that are expressed during PCD/removal in B. schlosseri colonies, and how developing buds regulate their activities (aim #1). Caspase-3, a cysteinyl protease, is the principal executioner caspase in mammalian cells. The proposed studies will seek to clone the B. schlosseri homologue of this gene using degenerate polymerase chain reaction technology. Determining the complete nucleotide and amino acid sequence of the caspase-3 gene will pave the way to investigate its expression pattern, substrate specificity and function in B. schlosseri colonies (aim #2). Recent findings from this laboratory have strongly suggested that Botryllus phagocytes may be critical effectors in homeostatic regeneration of tissues and new individuals, by functioning as recycling shuttles during the death phase of a B. schlosseri colony. Aim #3 will seek to investigate phagocytic function in this animal. Specifically, india ink and phosphatidylserine receptor-specific antibodies will be used to track phagocyte homing patterns during and following PCD and removal. Liposome-encapsulated dichloromethylene diphosphonate will also be used to selectively deplete circulating phagocytes. Lastly, DNA and protein-specific fluorescent tracers will be used to selectively label degenerating adult tissues and monitor their translocation and incorporation within developing buds.

描述（由申请人提供）：细胞死亡是多细胞动物生命中的一个重要方面，在细胞更新、胚胎发育和对环境应激的反应中起着不可或缺的作用。这个建议的长期目标是获得一个了解的分子基础，其中程序性细胞死亡（PCD）和程序性细胞去除调节在一个独特的模型系统，殖民urochordate Botryllus schlosseri，以及这些过程是如何平衡与斯特恩细胞衍生的有机体再生。在这种动物中，PCD每周以周期性方式发生，在此期间，群体中的所有成年个体在24小时内通过凋亡同步死亡。在此期间，来自成体组织的细胞尸体被循环的吞噬细胞吞噬，新一代的无性繁殖的成体同时取代了被再吸收的旧一代。拟定的研究将首先寻求确定在B中PCD/去除期间表达的细胞死亡机制的组分。schlosseri殖民地，以及如何发展芽调节他们的活动（目标#1）。 半胱氨酸蛋白酶-3（Caspase-3）是哺乳动物细胞中主要的半胱氨酸蛋白酶。拟议的研究将寻求克隆B。schlosseri同源基因的同源性。caspase-3基因的核苷酸和氨基酸序列的测定将为研究其在B细胞中的表达模式、底物特异性和功能奠定基础。schlosseri菌落（目标#2）。本实验室最近的研究结果强烈表明，葡萄球菌吞噬细胞可能是组织和新个体的稳态再生的关键效应子，在B的死亡阶段作为回收梭发挥作用。施洛塞里殖民地。目的#3将寻求研究该动物的吞噬功能。具体而言，印度墨水和磷脂酰丝氨酸受体特异性抗体将用于跟踪PCD和去除期间和之后的吞噬细胞归巢模式。脂质体包封的二氯亚甲基二膦酸酯也将用于选择性地消耗循环吞噬细胞。最后，DNA和蛋白质特异性荧光示踪剂将被用于选择性地标记退化的成体组织，并监测它们在发育芽中的移位和掺入。