玻璃体腔注射roscovitine对大鼠视网膜中Cdk5/p25活性和tau蛋白磷酸化的抑制作用  

Inhibition of roscovitine on the activity of Cdk5/p25 and phosphorylation of tau in retina of RCS rats after intravitreal injection

作　　者：张金金[1] 盛迅伦[1] 任英华[1] 容维宁[1] 李慧平[1] 刘雅妮[1] 

机构地区：[1]宁夏回族自治区人民医院 宁夏眼科医院,银川750001

出　　处：《中华实验眼科杂志》2015年第1期5-9,共5页Chinese Journal Of Experimental Ophthalmology

基　　金：国家自然科学基金项目（81060078）

摘　　要：背景 视网膜色素变性（RP）与阿尔茨海默病有着共同的发病机制,细胞周期依赖性蛋白激酶（Cdk5）活性及其激活剂参与中枢神经系统的退行性病变.Cdk5抑制剂roscovitine可以抑制Cdk5/p25通路的活性,从而抑制细胞凋亡,但其对RP的影响尚不清楚. 目的 探讨玻璃体腔注射roscovitine对RCS大鼠视网膜组织中p35、p25和tau蛋白表达的影响.方法 12只RCS大鼠于出生后17d右眼玻璃体腔注射4 μlroscovitine作为实验眼,左眼未进行任何干预作为对照眼.分别于注射后8d（出生后25 d）和18d（出生后35 d）用过量麻醉法各处死6只大鼠并分离视网膜,Western blot法检测RCS大鼠视网膜组织中Cdk5、p35、p25蛋白的相对表达水平和tau蛋白磷酸化水平,采用分光光度仪（光谱法）测定大鼠视网膜组织340 nm处的吸光度（A）值,定量分析大鼠视网膜中Cdk5/p25激酶活性,采用配对t检验比较实验眼和对照眼的检测结果.结果 玻璃体腔注射后8d和18d,大鼠实验眼视网膜组织中p35蛋白的相对表达水平分别为1.186±0.019和1.069±0.019,明显低于对照眼的1.364±0.016和1.214±0.008,差异均有统计学意义（t=-6.294、-6.477,均P＜0.05）;大鼠实验眼视网膜组织中p25蛋白的相对表达水平分别为0.312±0.009和0.269±0.018,明显低于对照眼的0.595±0.013和0.473±0.011,差异均有统计学意义（t=-36.508、-11.879,均P＜0.05）;实验眼与对照眼间大鼠视网膜中Cdk5蛋白的相对表达水平差异均无统计学意义（t=0.213、-0.540,均P＞0.05）;实验眼大鼠视网膜组织中tau蛋白磷酸化水平均低于对照眼,差异均有统计学意义（t=-9.854、-6.744,均P＜0.05）.玻璃体腔注射后8d和18d,比色定量测定法测得大鼠实验眼视网膜中Cdk5/p25活性分别为（0.003 8±0.000 14）mol/（s·mg）和（0.00201±0.000 11）mol/（s·mg）,明显低于对照眼的（0.005 47±0.000 27） mol/（s·mg）和（0.003 35±0.000 15） mol/（s·mg）,差异�Background Study determined that retinitis pigmentosa has a similar pathogenesis mechanism to Alzheimer disease,and activity of cyclin-dependent kinase 5 （Cdk5） and its activators participates in the degeneration of central nervous system.Roscovitine,an inhibitor of Cdk5,can suppress activity of Cdk5/p25 pathway and therefore inhibit cell apoptosis.However,the influence of roscovitine on retinitis pigmentosa（RP） is unclear.Objective This study was to investigate the expressions of p35,p25 and tau in the retinas of RCS rats.Methods Roscovitine of 4 μl was intravitreally injected in the right eyes of 12 SPF 17-day-old RCS rats,and the fellow eyes were not intervened as the control eyes.The rats were sacrificed on eighth day （postnatal 25 days） and eighteenth day （postnatal 35 days）,and whole retinas were isolated to evaluate the relative expressions of Cdk5,p35,p25 and tau phosphorylation by Western blot,and the activity of Cdk5/p25 was analyzed by quantitative colorimetric assay.The results were compared between the right eyes and fellow eyes by paired t test.The use and care of the rats complied with Ethic Statement of Experimental Animal of Ningxia Medical University.Results In the eighth and eighteenth day after injection,the relative expression values （A values） of p35 in rat retinas were 1.186±0.019 and 1.069± 0.019 in the injected eyes,showing significant decreases in comparison with 1.364±0.016 and 1.214±0.008 of the fellow eyes （t =-6.294,-6.477,both at P〈0.05）;the relative expression values （A values） of p25 in rat retinas were 0.312±0.009 and 0.269±0.018 in the injected eyes,which was significantly lower than 0.595±0.013 and 0.473±0.011 of the fellow eyes （t=-36.508,-11.879,both at P〈0.05）.No significant difference was found in the relative expression of Cdk5 protein between the injected eyes and the fellow eyes in various time points after injection （both at P〉0.05）.The activities of Cdk5/p25 were （0.003 83 ±0.000 14） mol/（s·mg） and （0.002 0

关 键 词：Cdk5/p25 抑制剂 ROSCOVITINE 凋亡 RCS大鼠 视网膜变性/遗传性 

分 类 号：R774.1[医药卫生—眼科]