Collagen-Annexin Interactions in Tissue Mineralization

组织矿化中胶原蛋白-膜联蛋白的相互作用

• 批准号: 6765887
• 负责人: THORSTEN KIRSCH
• 金额: $ 27.92万
• 依托单位: UNIVERSITY OF MARYLAND BALTIMORE
• 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 2008-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6765887
• 关键词: SDS polyacrylamide gel electrophoresis; annexins; apoptosis; calcium channel; calcium flux; cell differentiation; cell growth regulation; chick embryo; chondrocytes; collagen; flow cytometry; fluorescence microscopy; genetically modified animals; immunoprecipitation; in situ hybridization; infrared spectrometry; interferometry; laboratory mouse; microcalorimetry; normal ossification; polymerase chain reaction; protein protein interaction; protein structure function; terminal nick end labeling; tissue /cell culture; western blottings

Our long term goal of this study is to elucidate the roles of annexins II, V and VI and the interactions between annexin V and types II and X collagen in terminal differentiation events of chondrocytes. Terminal differentiation of growth plate chondrocytes consists of a series of events including mineralization and programmed cell death (apoptosis). These events play a crucial role during normal bone formation. If they, however, occur during pathological conditions, such as osteoarthritis, they will lead to cartilage destruction. Thus, an understanding of the cellular mechanisms controlling terminal differentiation of chondrocytes is of great importance. Major advances during the last funding period led to the following three new hypotheses which will be tested in the current proposal: (i) annexin channel formation in the plasma membrane of growth plate chondrocytes and annexin V channel activation by types II and X :ollagen lead to calcium influx into growth plate chondrocytes and alteration of calcium homeostasis; (ii) optimal annexin channel formation and annexin V/collagen interactions require the interactions between annexin II, V and VI; (iii) annexin-mediated alteration of calcium homeostasis regulates terminal differentiation events of growth plate chondrocytes. These hypotheses will be addressed through the following specific aims: 1. We will determine the function of annexin II, V and VI channel formation and annexin V/collagen interactions in alteration of calcium homeostasis in growth plate chondrocytes and test whether annexins through binding to collagen and cytoskeleton act as mechanosensors in these cells. 2. We will determine the interactions between annexin II, V and VI as a possible major regulator of annexin channel formation and annexin V/collagen interactions. 3. We will determine the regulatory roles of annexins and annexin V/collagen interactions in terminal differentiation events including mineralization and apoptosis of growth plate chondrocytes.This study relates directly to the mechanisms which control terminal differentiation of chondrocytes and investigates a novel mechanism regulating calcium homeostasis in skeletal cells.Thus, this proposal will not only greatly advance our understanding of how terminal differentiation events are regulated, but it might also provide novel therapeutic targets to prevent terminal differentiation events during patholoaical conditions.

本研究的长期目标是阐明膜联蛋白II、V和VI的作用以及膜联蛋白V与II型和X型胶原在软骨细胞终末分化事件中的相互作用。生长板软骨细胞的终末分化包括一系列事件，包括矿化和程序性细胞死亡（凋亡）。这些事件在正常骨形成过程中起着至关重要的作用。然而，如果它们发生在病理条件下，如骨关节炎，它们将导致软骨破坏。因此，了解控制软骨细胞终末分化的细胞机制是非常重要的。在上一个资助期间的重大进展导致了以下三个新的假设，这些假设将在本提案中进行测试：（i）生长板软骨细胞质膜中膜联蛋白通道的形成和II型和X型膜联蛋白V通道的激活 ：胶原导致钙流入生长板软骨细胞和钙稳态的改变;（ii）最佳膜联蛋白通道形成和膜联蛋白V/胶原相互作用需要膜联蛋白II、V和VI之间的相互作用;（iii）膜联蛋白介导的钙稳态的改变调节生长板软骨细胞的终末分化事件。这些假设将通过以下具体目标来解决：1。我们将确定膜联蛋白II，V和VI通道的形成和膜联蛋白V/胶原蛋白的相互作用在生长板软骨细胞中钙稳态的改变的功能，并测试膜联蛋白是否通过结合到胶原蛋白和细胞骨架作为这些细胞中的机械传感器。2.我们将确定膜联蛋白II，V和VI之间的相互作用作为膜联蛋白通道形成和膜联蛋白V/胶原蛋白相互作用的可能的主要调节剂。3.我们将确定监管角色 Annexin和Annexin V/胶原相互作用在终末分化过程中的作用，包括生长板软骨细胞的矿化和凋亡。本研究直接涉及软骨细胞终末分化的控制机制，并研究了一种调节骨骼细胞钙稳态的新机制。因此，这一建议不仅将大大促进我们对终末分化过程如何调节的理解，而且它还可能提供新的治疗靶点以防止病理条件期间的终末分化事件。