糖尿病视网膜病变是最为常见的糖尿病微血管并发症，主要由糖尿病引起的机体代谢紊乱导致。而然在临床工作中发现，部分患者通过单纯控制血糖以延缓糖尿病视网膜病变进展，所取得效果不甚理想，一些其他因素对于糖尿病视网膜病变的发生、发展，也起到不可忽视的作用。研究表明，在并发高脂血症的糖尿病视网膜病变患者中，胆固醇代谢异常是诱发视网膜病变的主要原因之一。胆固醇代谢异常通过减弱肝脏X受体，导致胆固醇在视网膜上不断积累，降低视网膜血管内皮功能，从而造成视网膜缺血、缺氧环境的形成，又可通过增加炎症因子和细胞黏附分子-1的表达，使原本病态的糖尿病视网膜血管变得更加脆弱，该文总结了糖尿病视网膜病变的病理因素，对比分析当前糖尿病视网膜病变的主要治疗手段，通过分析胆固醇逆向转运(cholesterol reverse transport,RCT)途径转运对糖尿病视网膜病变发生、发展的影响，发现降低高血脂可提高糖尿病视网膜病变的治愈率，这将为糖尿病视网膜病变的临床防治工作提供新思路。
Diabetic retinopathy is the most common diabetic microvascular complication, which is mainly caused by metabolic disorders caused by diabetes. However, in clinical work, it is found that some patients do not achieve satisfactory results in delaying the progress of diabetic retinopathy by simply controlling blood sugar, and some other factors contribute to the occurrence and development of diabetic retinopathy. Also played a role that can not be ignored. Studies have shown that abnormal cholesterol metabolism is one of the main causes of retinopathy in diabetic retinopathy patients with hyperlipidemia. Abnormal cholesterol metabolism leads to the accumulation of cholesterol in the retina and the decrease of retinal vascular endothelial function by weakening the X receptor in the liver, resulting in the formation of retinal ischemia and hypoxia environment. it can also increase the expression of inflammatory cytokines and cell adhesion molecule-1 to make the originally morbid retinal vessels more fragile. This paper summarizes the pathological factors of diabetic retinopathy. By comparing and analyzing the main treatment methods of diabetic retinopathy at present, and by analyzing the influence of cholesterol reverse transport (cholesterolreversetransport,RCT) pathway on the occurrence and development of diabetic retinopathy, it is found that reducing hyperlipidemia can improve the cure rate of diabetic retinopathy, which will provide new ideas for the clinical prevention and treatment of diabetic retinopathy.
目的：玻璃膜疣主要成分胆固醇对人视网膜色素上皮细胞ARPE-19中细胞膜钙ATP酶1(plasma membrane Ca2+ ATPase 1，PMCA1)、L型电压依赖性钙离子通道(L-type voltage-dependent calcium channel，LVDCC)和细胞膜钠钙交换蛋白1(sodium calcium exchange protein 1，NCX1)表达的影响。方法：体外培养ARPE-19细胞，将细胞分为对照组和胆固醇处理组(2.5 mg/mL)，取样时间为0、6、12、24、48、72 h。通过实时定量PCR检测PMCA1、LVDCC和NCX1 mRNA的表达水平，用蛋白质印迹法检测蛋白质的表达水平。结果：主要负责细胞内钙离子外排的PMCA1的mRNA和蛋白表达水平在胆固醇处理下出现下调。在胆固醇处理下，钙流入通道LVDCC和钙稳态调控蛋白NCX1的mRNA和蛋白表达明显增多，并且呈现时间依赖性，都是在24 h或48 h表达最多后出现回落。其中LVDCC表达上调倍数较大。结论：玻璃膜疣主要成分胆固醇可以影响人视网膜色素上皮细胞中钙转运通道蛋白的表达，PMCA1的表达受到胆固醇抑制， LVDCC和NCX1的表达受到胆固醇处理上调。这可能会影响细胞内钙离子外排，引起钙离子内流，是否能进一步导致细胞内钙超载而引起细胞凋亡，值得探讨。
Objective: To study the effects of cholesterol, the main component of drusen, on the expression plasma membrane Ca2+ ATPase 1 (PMCA1), L-type voltage-dependent calcium channel (LVDCC) and cell membrane sodium calcium exchange protein 1 (NCX1) of ARPE-19 cells. Methods: The ARPE-19 cell line was cultured in vitro, and the cells were divided into a control group and a cholesterol treatment group (2.5 mg/mL). The treatment time was 0, 6, 12, 24, 48, 72 hours. Real-time quantitative PCR was used to detect the expression of PMCA1, LVDCC and NCX1 at the mRNA level, and western blot was used to detect the expression at the protein level. Results: The mRNA and protein expression levels of PMCA1 which mainly responsible for the efflux of intracellular calcium ions, was down regulated under cholesterol treatment. Meanwhile, the expression of the mRNA and protein of the calcium inflow channel LVDCC and calcium stability regulatory protein NCX1 were significantly increased, and the time-dependency was present, which was up expressed to 24 or 48 h and then fell back. Among them, the LVDCC expression had a large number of times. Conclusion: Cholesterol, the main component of drusen, can affect the expression of calcium channels in human retinal pigment epithelial cells. The expression of PMCA1 was suppressed by cholesterol, and expression of LVDCC and NCX1 were up-regulated with cholesterol treatment, which may affect intracellular calcium efflux then cause calcium influx. Whether it can further cause intracellular calcium overload and cell death is worth exploring.
目的：研究玻璃膜疣主要成分胆固醇对人视网膜色素上皮细胞ARPE-19中金属硫蛋白表达的影响。方法：体外培养ARPE-19细胞，将细胞分为对照组和胆固醇处理组(2.5 mg/mL)，取样时间为0，6，12，24，48，72h。通过实时定量PCR检测hMT1a，hMT2a和hMT3在转录水平的表达，用蛋白质印迹法检测总金属硫蛋白的表达。结果：在转录水平上hMT1a，hMT2a和hMT3受到胆固醇影响mRNA表达上调，且hMT3上调倍数最大；总金属硫蛋白的蛋白表达随着胆固醇处理时间延长明显增多。结论：玻璃膜疣主要成分胆固醇可以上调人视网膜色素上皮细胞中金属硫蛋白的表达，提示金属硫蛋白表达可受到玻璃膜疣形成起始阶段的刺激，其检测是否能用于年龄相关性黄斑变性的早期发现及早期诊断还需深入探讨。
Objective: To study the effects of cholesterol, the main component of drusen, on the expression of metallothionein of ARPE-19 cells. Methods: The ARPE-19 cell line was cultured in vitro, and the cells were divided into a control group and a cholesterol treatment group (2.5 mg/mL). The treatment time was 0, 6, 12, 24, 48, 72 hours. Real- time quantitative PCR was used to detect the expression of hMT1a, hMT2a and hMT3 at the mRNA level, and Western blot was used to detect the expression at the protein level. Results: The mRNA expression of hMT1a, hMT2a and hMT3 were up-regulated by cholesterol and the protein expression of total MTs was increased with cholesterol treatment. Conclusion: Cholesterol, the main component of drusen, can up-regulate the expression of metallothionein in human retinal pigment epithelial cells, suggesting that the expression of metallothionine can be stimulated by the initial stage of drusen formation. However, whether its detection can be used for the early detection and early diagnosis of age-related macular degeneration or not still needs to be further explored.
