氧化损伤在玻璃体液化致核性白内障形成中关键分子的鉴定和调控机制研究

The prevention of vitreous liquefaction induced oxidative damage in nuclear cataract formation is the important subject regarding to the study on age-related ophthalmic diseases. Our previous studies have reported that liquefaction of vitreous and vitrectomy were proved to accelerate the nuclear cataract formation by increasing oxygen diffusion from retina to lens which would induce oxygen damage on lens. In the most recent, the mass spectrometric analysis by isobaric tags for relative and absolute quantitation (iTRAQ) have revealed that the most different proteins in lenses with longer ocular axis and liquefaction of vitreous are related to oxidative stress. Based on the human cataract lenses with high myopia and vitreous liquefaction and lens epithelium cells incubation models, this project will take further step to identify the critical molecules of oxidative damage in those lenses, to screen the regulating and controlling those targeted proteins and its related miRNA by using gene chip, to clarify how miRNA regulates expression and modification of proteins in lens during oxygen damage process and its signaling pathways. This study is designed to study mechanism of oxygen damage on vitreous liquefaction induced nuclear cataract through miRNAs and proteomics.

玻璃体液化致眼内氧化损伤形成白内障的机制和防治是年龄相关性眼病研究的重要问题。课题组前期证实，玻璃体液化和玻璃体切除手术可导致玻璃体腔内氧弥散的增加，加速了晶状体的氧化损伤；进而采用相对和绝对定量同位素标记（iTRAQ）质谱分析技术，初步筛查出长眼轴伴玻璃体液化白内障晶状体蛋白质的变化，与氧化应激通路密切相关。本课题通过高度近视性玻璃体液化白内障标本联合人晶状体上皮细胞培养和氧化损伤模型，以晶状体氧化损伤和修复机制为主线，进一步鉴定氧化损伤的关键分子，确定其在晶状体氧化损伤中的作用和机制，并通过芯片筛查调控目标蛋白质表达的相关miRNA，阐明玻璃体液化致核性白内障过程中，miRNA调控和蛋白的表达及调控机制。旨在探讨玻璃体内氧环境变化与白内障形成的机制，为研究以晶状体核性混浊为主要特征的年龄相关性白内障发生发展的关键环节提供新的理论和实验基础，以期对白内障防治提供临床上行之有效的新途径。

背景：玻璃体液化致眼内氧化损伤形成白内障的机制和防治是年龄相关性眼病研究的重要问题。课题组前期证实，玻璃体液化和玻璃体切除手术可导致玻璃体腔内氧弥散的增加，加速了晶状体的氧化损伤；进而采用相对和绝对定量同位素标记（iTRAQ）质谱分析技术，初步筛查出长眼轴伴玻璃体液化白内障晶状体蛋白质的变化，与氧化应激通路密切相关。.研究内容：本课题通过高度近视性玻璃体液化白内障标本联合人晶状体上皮细胞培养和氧化损伤模型，以晶状体氧化损伤和修复机制为主线，进一步鉴定氧化损伤的关键分子，确定其在晶状体氧化损伤中的作用和机制，并通过芯片筛查调控目标蛋白质表达的相关miRNA，阐明玻璃体液化致核性白内障过程中，miRNA 调控和蛋白的表达及调控机制。.研究结果：通过超声弹性成像检测年龄与眼轴相关性晶状体核硬度，发现核硬度随年龄与眼轴长度增加；通过iTARQ技术筛选并验证了与年龄及眼轴长度相关的差异蛋白质；通过基因芯片筛选并验证了与晶状体上皮细胞氧化损伤相关的microRNA,包括miR-630,miR-210-3p和miR-34a-5p；机制研究发现，miR-630通过调控靶基因ALCAM的表达水平，影响人晶状体上皮细胞的迁移能力。.科学意义：为研究以晶状体核性混浊为主要特征的年龄相关性白内障发生发展的关键环节提供了新的理论和实验基础。