PROTEIN MODIFICATION IN AGE-RELATED RETINAL DEGENERATION

我们的目标是阐明视网膜变性的分子机制，如年龄相关性黄斑变性。 最近的证据表明，发病机制包括增加蛋白质和脂质氧化和细胞成分的回收不足。 蛋白酶体是蛋白水解酶，负责回收大部分细胞蛋白，包括氧化和错误折叠的蛋白。 由于蛋白酶体功能减弱，氧化蛋白可能积聚。 我们将检验蛋白酶体功能缺陷和氧化蛋白质积累导致视网膜变性的基因合成假说。 将在Fisher 344大鼠（10、23、26个月）视网膜的视杆外段（ROS）和视网膜色素上皮（RPE）中研究蛋白酶体功能和蛋白质氧化损伤的程度。 由于（a）光、（B）富氧环境和（c）含有高浓度易氧化的多不饱和脂肪酸的膜的组合，视网膜特别容易受到氧化损伤。将追求以下目标：（1）定义蛋白酶体表达和功能与年龄相关的变化。 这一目标将检验衰老伴随着蛋白酶体活性降低的假设。 (2)量化蛋白质氧化的程度。 我们预测更广泛的氧化修饰老年大鼠相比，年轻的大鼠。生物化学和免疫组织化学技术将被用来研究蛋白酶体功能，蛋白质氧化，和视网膜变性的程度，在视网膜从三个不同年龄的大鼠。虽然有相当多的证据表明氧化应激增加和其他组织中蛋白质周转减少有关，但需要该试点项目提供第一个明确的证据，证明这些影响与年龄相关的视网膜变性有关。氧化或错误折叠的蛋白质的积累已经在许多与年龄相关的退行性疾病中得到证实，例如阿尔茨海默病和帕金森病。 因此，蛋白酶体功能障碍可能是许多与年龄相关的变性疾病的常见潜在机制。 这项研究将扩展我们对蛋白酶体功能的基本机制的认识，这是开发治疗干预措施的第一步。

Our goal is to elucidate the moleccular mechanisms involved in degeneration of the retina, as occurs in age-related macular degeneration. Recent evidence suggests that the pathogenesis includes increased protein and lipid oxidation and inadequate recycling of cell constituents. The proteasome is the proteolytic enzyme responsible for recycling the majority of cell proteins, including oxidized and misfolded proteins. Oxidized proteins could accumulate due to diminished proteasome function. We will test the gypothesis that defects in proteasome function and the accumulation of oxidized proteins result in retinal degeneration. Proteasome function and the extent of oxidative damage to proteins will be investigated in rod outer segments (ROS) and the retinal pigment epithelium (RPE) of the retinas from Fisher 344 rats (10, 23, 26 months). The retina is particularly susceptible to oxidative damage because of the combination of (a) light, (b) an oxygen-rich environment, and (c) membranes containing a high concentration of polyunsaturated fatty acids that are easily oxidized. The following aims will be pursued: (1) Define age-related changes in proteasome expression and function. This aim will test the hypothesis that aging is accompanied by decreased proteasome activity. (2) Quantify the extent of protein oxidation. We predict more extensive oxidative modifications in aged compared with younger rats. Biochemical and immunohistochemical techniques will be used to investigate proteasome function, protein oxidation, and the extent of retinal degeneration in the retinas from three different age rats. Although there is considerable evidence linking increased oxidative stress and diminished protein turnover in other tissues, the pilot project is needed to provide the first clear evidence that these effects correlate with age-related retinal degeneration. The accumulation of oxidized or misfolded proteins has been demonstrated in a host of age-related degenerative diseases, such as Alzheimer's and Parkinson's diseases. Thus proteasome dysfunction may be the common, underlying mechanism for a number of age- related degeneration diseases. This study will extend our knowledge of the basic mechanism of proteasome function, a first step in developing therapeutic interventions.