Rottlerin通过抑制PKCδ-ERK1/2通路减轻6-羟基多巴胺所致多巴胺能细胞凋亡  

Rottlerin Protects Dopaminergic Cells Line from 6-Hydroxydopamineinduced-apoptosis via Inhibiting PKCδ-ERK Signaling Pathway

作　　者：范鹰[1] 李静[1] 杨奕[1] 马兰[1] 张艳桥[2] 张一娜[1] 

机构地区：[1]哈尔滨医科大学附属第二医院老年病科 [2]哈尔滨医科大学附属第三医院内八科,哈尔滨150081

出　　处：《中国生物化学与分子生物学报》2011年第12期1133-1140,共8页Chinese Journal of Biochemistry and Molecular Biology

基　　金：黑龙江省科技厅国际合作项目(No.WB08B05);黑龙江省教育厅面上项目(No.11521076);哈尔滨医科大学附属第二医院博士科研基金项目(No.BS2008-22)~~

摘　　要：近来发现新的蛋白激酶Cδ亚型(PKCδ)的磷酸化激活与帕金森病(PD)中神经元的缺失有关.我们的前期研究发现,PKCδ磷酸化参与6-羟基多巴胺引起的多巴胺能细胞的毒性作用,但其具体机制尚不清楚.本研究以TUNEL检测发现,6-羟基多巴胺引起较显著的细胞凋亡,PKCδ抑制剂Rottlerin可减轻6-羟基多巴胺诱导的凋亡,总PKC抑制剂Bis、钙依赖性PKC(α和β)抑制剂G6976对6-羟基多巴胺诱导的凋亡无影响.采用Western免疫印迹杂交实验发现,6-羟基多巴胺持续性激活ERK 1/2和PKCδ,Rottlerin既可抑制PKCδ的磷酸化激活,又可抑制ERK的磷酸化激活,而MEK抑制剂U0126仅能抑制ERK 1/2磷酸化激活,对PKCδ磷酸化却无显著影响.这说明PKCδ是6-羟基多巴胺持续性激活ERK 1/2的上游激酶.本研究结果提示,在凋亡过程中PKCδ仍然是ERK1/2激活的上游激酶,阻断PKCδ磷酸化可阻断ERK1/2持续激活.Rottlerin正是由于阻断PKCδ的激活,进一步阻断ERK1/2持续激活,减轻多巴胺能细胞的凋亡.因此,Rottlerin可能对防治帕金森病患者神经元缺失有一定作用.Recent studies suggest that the activation of protein kinase C delta（PKCδ） is related to the loss of neurons in Parkinson＇s disease（PD）.Our previous studies have shown that activation of PKCδ was involved in the dopaminergic cell death mediated by 6-hydroxydopamine.However,its exact mechanism still remains largely elusive.In this study,the apoptotic rate of PC12 cells induced by 200 μmol/L 6-hydroxydopamine was 33.8%±8.3% by terminal-deoxynucleotidyl-transferase-mediated nick end labeling（TUNEL）.Rottlerin,a selective inhibitor of PKCδ,decreased the rate of apoptosis.In contrast,bisindolylmaleimide I and G6976 did not affect 6-hydroxydopamine-induced cell death.Western blotting showed that 6-hydroxydopamine could consistently activated both PKCδ and extracellular signal-regulated kinase（ERK） 1/2.Rottlerin decreased both ERK1/2 and PKCδ phosphorylation evoked by 6-hydroxydopamine.However,U0126,a MEK inhibitor,could only decrease ERK1/2 phosphorylation,but not decrease PKCδ phosphorylation.Thus,phosphorylated PKCδ,instead of general PKC or classic-type PKC（α,β1,β2,γ）,participated in 6-hydroxydopamine-induced neurotoxicity in PC12 cells and PKCδ is the upstream kinase of ERK activation.These results also indicated that Rottlerin protected PC12 from apoptosis by inhibiting PKC-ERK signaling pathway,implicating inhibiting PKCδ may ameliorate neural loss of Parkinsonian.

关 键 词：ROTTLERIN 6-羟基多巴胺 蛋白激酶C 蛋白激酶Cδ亚型 细胞外信号调节激酶1/2 凋亡 

分 类 号：R742.5[医药卫生—神经病学与精神病学]