DMT1在多巴胺能神经元变性中的作用研究

Role of divalent metal transporter 1 in degeneration of dopaminergic neuron

目的:研究二价金属离子转运蛋白1(DMT1)在乳胞素(lactacystin)诱导的SH-SY5Y细胞中的表达改变,从而进一步了解DMT1在帕金森病(PD)神经元损伤中的可能作用机制。方法:建立lactacystin损伤的SH-SY5Y细胞模型,用免疫荧光、Western blotting等方法检测细胞DMT1表达水平的变化;在高亚铁环境下,荧光探针DCFH-DA检测胞内氧化应激水平的变化,免疫组织化学法、Western blotting检测胞内α-突触核蛋白(α-SYN)聚合体的改变。结果:Lactacystin处理后,细胞活力呈浓度依赖性降低。与正常对照组相比,lactacystin处理组DMT1表达增加(P<0.01)。正常对照组、lactacystin处理组及Fe2+处理组3组比较,其细胞活力逐渐降低,胞内氧化应激反应逐渐增强,胞浆α-SYN低聚体(43-55 kD)表达量逐渐增多(P<0.05)。结论:Lactacystin诱导SH-SY5Y细胞高表达DMT1,增强细胞摄铁能力,这可能是铁直接或者通过氧化应激反应促进胞内α-SYN的错误折叠和聚集、最终导致PD神经元损伤的关键因素。

AEM： To observe the expression of divalent metal transporter 1 （ DMT1 ） in SH - SY5Y cells with lactacystin- induced injury, and to investigate the possible role of DMT1 in the degeneration of dopaminergic neuron in Parkinson disease（PD）. METHODS： An in vitro model of cell injury was established in SH - SYSY cells induced by lactacystin. The protein expression of DMT1 was detected by immunofluorescence and Western blotting. Under the environ- ment of high iron level, the cellular oxidative stress was observed by fluorescent probe DCFH - DA. The level of ot - synu- clein was determined by immunohistochemistry and Western blotting. RESULTS： The cell viability rate was reduced by lactacystin in a concentration - dependent pattern. Compared with the control, the protein level of DMT1 was obviously increased in lactacystin - treated cells. The arrangements of the changes from high to low in decreased cell viability, increased intracellular oxidative stress and increased aggregation of α -synuclein （43 -55 kD） were Fe2 ＋ treatment group 〉 lactacystin treatment group 〉 control group（ P 〈 0.05 ）. CONCLUSION： Lactacystin up - regulates the protein expres- sion of DMTI. By this way, the increased function of DMTI - mediated iron uptake may play an important role in iron or i- ron - catalyzed oxidative reactions to enhance a - synuclein aggregation, leading to the degeneration of neurons in PD.