Age-related macular degeneration: signal transduction leading to changed secretion of angiogenic factors by retinal pigment epithelial cells from excised neovascular membranes

本研究的目的是对老年性黄斑变性的血管生成诱导机制有新的认识。视网膜色素上皮(RPE)分泌的血管生成因子在这一过程中起着核心作用。这种分泌是自身/旁分泌刺激的，或由这些细胞微环境的变化诱导。使用膜片钳技术的细胞生理学研究将在老年性黄斑变性患者的眼科手术获得的增殖膜或新生血管膜中新鲜分离或培养的RPE细胞上进行。我们将对这些RPE细胞主要表达的钙和钾通道的特性进行研究，以研究它们的分化。然后将描述分泌刺激因子的细胞内信号转导。信号转导的研究将集中在生长因子、晚期糖基化终产物和整合素配体的刺激作用上。将荧光黄添加到吸管溶液中，用于对新鲜分离的RPE细胞进行全细胞记录，可以进行后续的免疫组织化学分析以进行鉴定。为了比较的目的，我们将用膜片钳技术和生化方法研究培养的人和大鼠RPE细胞中分泌刺激因子的信号转导。

The aim of this study is to gain new insights into angiogenesis-inducing mechanisms in age-related macular degeneration. Secretion of angiogenic factors by the retinal pigment epithelium (RPE) plays a central role in this process. This secretion is auto-/paracrine-stimulated or induced by changes in the microenvironment of these cells. Cellular physiological studies using patch-clamp techniques will be performed on freshly isolated or cultured RPE cells from proliferative or neovascular membranes obtained by eye surgery in patients with age-related macular degeneration. The characteristics of mainly Ca2+ and K+ channels expressed in these RPE cells will be investigated in order to study their differentiation. Then the intracellular signal transduction of secretion-stimulating factors will be described. Studies on signal transduction will be focused on stimulation by growth factors, advanced glycation endproducts and integrin ligands. Adding lucifer yellow to the pipette solution for whole-cell recordings on freshly isolated RPE cells allows the subsequent immunohistochemical analysis for identification. For purposes of comparison, the signal transduction of secretion-stimulating factors in cultured human and rat RPE cells will be studied by patch-clamp techniques and biochemical methods.