SIGNALS FOR RPE SURVIVAL IN VITRO

描述(摘自申请者摘要)：长期目标 这项研究是为了了解RPE增长控制是如何维持的。是这样的 控制对支持光感受器的正常上皮功能至关重要 细胞。此外，RPE细胞数量的失调，如在 老年性黄斑变性与增殖性玻璃体视网膜病变 (PVR)，对视网膜健康构成重大威胁。极端的 这些细胞的寿命，以及它们在 正常情况下，突出了这样一个事实，即上皮细胞的存活是一种 派拉蒙战略。因此，这些研究的重点是生存 机制，使用体外系统，借此条件可能精确 控制住了。单个RPE细胞，剥夺了所有外源生存因素， 在培养中经历一种形式的程序性细胞死亡。此外，同样的 通过附着和传播，细胞可以从细胞死亡中解救出来。 涂有细胞外基质(ECM)蛋白的底物。vbl.使用 依附于纤维连接蛋白作为细胞与其相互作用的模型 自然底物，拟议的研究目的是识别和控制 影响依附的单个细胞生物学成分 RPE细胞存活。实验将确定细胞表面的作用 整合素(纤维连接蛋白受体)的激活和细胞形态的变化 触发细胞存活的刺激。一个潜在的信号伴随着 细胞-细胞外基质相互作用，蛋白质酪氨酸磷酸化，将在 在生化和细胞活力的联合研究中提供了详细的信息。此外， 小分子GTP结合蛋白RhoA在介导生存效应中的作用 的细胞扩散将通过显微注射到一个细胞 这种蛋白质的特定失活剂。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结果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.