EGCG对富亮氨酸重复激酶2活性的影响及其作用机制

目的: 研究表没食子儿茶素没食子酸酯(epigallocatechin 3 gallate, EGCG)对富亮氨酸重复激酶2(leucine rich repeat kinase 2, LRRK2)活性的影响及其分子机制。方法: 选用Ddc LRRK2 G2019S品系果蝇，分为7组，对照组用标准玉米培养基饲养，各实验组果蝇分别用含LRRK2抑制剂GW5074、N 乙酰半胱氨酸（NAC）及浓度为0.1、1、10和100 μmol/L的EGCG加药培养基饲养，检测并统计果蝇生命周期和运动能力，筛选出药物作用的最佳浓度与最适时间点；用蛋白质印迹法检测果蝇脑组织中p LRRK2、p p38 MAPK、核因子E2相关因子2(nuclear factor erythroid 2 related factor 2, Nrf2)、p ERK1/2和酪氨酸羟化酶(TH)等蛋白的表达。结果： 与对照组相比，10 μmol/L EGCG延长果蝇寿命、改善果蝇运动能力的效果最为突出，1 μmol/L EGCG效果较好(P<0.05)；各组果蝇第5周时行为学变化最显著(均P<0.05)；与对照组相比，10 μmol/L 和1 μmol/L EGCG组Nrf2、p ERK1/2、TH表达均明显增加(均P<0.05)，p LRRK2、p p38 MAPK表达明显降低(P<0.05)。 结论： EGCG可能通过Keap1 Nrf2 ARE、MAPK等信号通路有效抑制LRRK2激酶活性。

The effect of epigallocatechin 3 gallate on LRRK2 activity and its mechanism

Objective: To study the effect of epigallocatechin 3 gallate (EGCG) on leucine rich repeat kinase 2 (LRRK2) activities in Drosophila model and its potential molecular mechanism. Methods: Ddc LRRK2 G2019S strains of Drosophila was selected and divided into 7 groups. The control group was fed with standard corn medium. The Drosophila of each experimental group were fed with medium containing GW5074, NAC and EGCG with concentrations of 0.1, 1, 10 and 100 μmol/L, respectively. The life span and motor function of Drosophila were tested and screened for the optimal concentration and optimal time of drug action.Western blotting was used to detect p LRRK2, p p38 MAPK, nuclear factor erythroid 2 related factor 2(Nrf2), p ERK1/2 and tyrosine hydroxylase(TH) protein expressions in Drosophila brain tissues. Results: Compared with the control group, both 10 μmol/L EGCG group and 1 μmol/L EGCG group had significantly prolonged the lifespan and improved the motor function of Drosophila(P<0.05), while the effect of 0.1 μmol/L EGCG and 100 μmol/L EGCG group was not significant; there were marked differences in the behavioral changes of Drosophila in the 5th week(P<0.05). Compared with the control group, 10 μmol/L and 1 μmol/L EGCG group showed significantly higher expression of Nrf2, p ERK1/2 and lower expression of p LRRK2, p p38 MAPK(P<0.05). Conclusion: EGCG might effectively inhibit LRRK2 kinase activity through signaling pathways such as Keap1 Nrf2 ARE and MAPK.