SIGNALS FOR RPE SURVIVAL IN VITRO

描述（改编自申请人摘要）：长期目标 本研究旨在了解RPE生长控制是如何维持的。 等 控制对于支持感光细胞的正常上皮功能至关重要 细胞 此外，RPE细胞数量的失调，例如在视网膜色素上皮细胞中发生。 年龄相关性黄斑变性（AMD）和增殖性玻璃体视网膜病变 (PVR)对视网膜健康构成重大威胁。 极端 这些细胞的寿命，以及它们有限的再生能力， 正常情况下，突出的事实，上皮细胞存活是一个 最重要的战略 因此，这些研究侧重于生存 机制，使用体外系统，条件可以精确地 控制。 单个RPE细胞，剥夺了所有外源性存活因子， 在培养中经历一种程序性细胞死亡。 此外，同样 细胞可以通过附着，并在其上扩散， 用细胞外基质（ECM）蛋白包被的基质。 使用 附着到纤连蛋白作为细胞与其相互作用的模型， 建议的研究旨在识别和控制 有助于附着介导的单个细胞生物组分 RPE细胞存活。 实验将确定细胞表面的作用 整合素（纤连蛋白受体）激活和细胞形状变化， 触发细胞存活的刺激。 一个潜在的信号伴随着 细胞-ECM相互作用，蛋白酪氨酸磷酸化，将在 详细的生物化学和细胞活力研究。 此外该 小GTP结合蛋白RhoA在介导存活效应中的作用 将通过显微注射到细胞中来检查细胞扩散的程度。 这种蛋白质的特异性灭活剂。 通过将特定分子定义为 促进或抑制细胞存活或死亡的靶点，信息 从这些研究中获得的信息可能构成设计治疗方案的基础。 干预RPE增殖和萎缩的策略。

DESCRIPTION (Adapted from applicant's abstract): The long-term objective of this research is to understand how RPE growth control is maintained. Such control is vital to normal epithelial function in supporting photoreceptor cells. Furthermore, dysregulation of RPE cell number, such as occurs in age-related macular degeneration (AMD) and proliferative vitreoretinopathy (PVR), constitutes a significant threat to retinal health. The extreme longevity of these cells, and their limited regenerative capacity under normal conditions, highlight the fact that epithelial cell survival is a paramount strategy. Consequently, these studies focus on survival mechanisms, using an in vitro system whereby conditions may be precisely controlled. Single RPE cells, deprived of all exogenous survival factors, undergo a form of programmed cell death in culture. Furthermore, the same cells can be rescued from cell death by attachment to, and spreading on, substrates coated with extracellular matrix (ECM) proteins. Using attachment to fibronectin as a model of the cell's interaction with its natural substratum, the proposed studies aim to identify and control the individual cell biological components contributing to attachment-mediated RPE cell survival. Experiments will define the roles of cell-surface integrin (fibronectin receptor) activation and cell shape changes as triggering stimuli for cell survival. One potential signal accompanying cell-ECM interaction, protein tyrosine phosphorylation, will be examined in detail in combined biochemical and cell viability studies. In addition, the role of the small GTP-binding protein RhoA in mediating the survival effects of cell spreading will be examined by microinjection into cells of a specific inactivator of this protein. By defining specific molecules as targets for promoting or inhibiting cell survival or death, information gained from these studies may form the basis for designing therapeutic strategies to intervene in RPE proliferation and atrophy.