氯化锂治疗慢性青光眼神经退行性病变的作用机制

The effective mechanism of Lithium chlo ride on treatment of chronic glaucoma about neural degenerative diseases

目的观察在慢性青光眼大鼠视网膜神经节细胞层中Tau蛋白磷酸化的变化,并通过利用氯化锂抑制Tau上游激酶GSK-3β活性的实验,为在临床上用氯化锂治疗慢性青光眼神经退行性变提供实验依据。方法建立慢性高眼压SD大鼠模型,分为2组。一组为高眼压未治疗组,另一组为高眼压氯化锂治疗组,每组各15只。右眼为高眼压模型眼,左眼为对照眼。治疗组于建模当天起每天腹腔注射0.6 mol·L-1氯化锂(GSK-3β抑制剂)。在2周和4周从2组中各取3只大鼠处死并摘取眼球,Western blot方法观察视网膜总Tau和磷酸化Tau蛋白的变化;并于2周、4周,从2组中各取2只大鼠处死并摘除眼球,免疫荧光化学染色检测Tau蛋白在视网膜组织的表达。结果高眼压模型建立成功。高眼压模型眼总Tau含量在2周时下降为对照眼的77.3%,在4周时下降为对照眼的60.4%;P-Tau与总Tau的比值,在2周时几乎没有变化,在4周时增加至对照眼的135.4%,磷酸化明显增加。氯化锂对高眼压模型鼠的影响:在4周时,高眼压氯化锂治疗组视网膜总Tau含量较高眼压未治疗组明显升高,为对照眼的99%;P-Tau与总Tau的比值较高眼压未治疗组明显下降,几乎降至对照眼水平。在高眼压未治疗组视网膜,总Tau蛋白和磷酸化Tau蛋白的表达在各层都显著减少;而高眼压氯化锂治疗组视网膜总Tau蛋白和磷酸化Tau蛋白的表达在各层都较高眼压未治疗组有显著增加。结论持续高眼压刺激导致大鼠视网膜总Tau蛋白表达量降低,Tau蛋白磷酸化水平增加;氯化锂能减轻由持续高眼压引起的Tau蛋白的过度磷酸化。

Objective To investigate the variation of Tau phosphorylation on a retinal ganglion cell layer of rat with chronic glaucoma. By using the activity test of Lith- ium chloride to inhibit the upstream kinase GSK-3 β of Tau in order to provide experi- mental basis of Lithium chloride on treatment of chronic glaucoma about neural degen- erative diseases in clinic treatment. Methods To build up a model for the intraocular hypertension SD rat, divided into two groups. Group one was the untreated intraocular hypertension group, the other was the intraocular hypertension Lithium chloride treated group, 15 mice in each group. The right eyes were the model of intraocular hypertension while the left were the control ones. The treated group was injected 0.6 mol · L - l Lithi- um chloride （ GSK-3β inhibitor） on enterocoelia everyday since the model had made. During the second and fourth week taking 3 mice from each group and killed them and then took off their eyeballs. To investigate the variation of the whole Tau and the Tau protein on the retina using Western-blot method. And during the second and fourth week taldng 2 mice from each group and klled them and then took off their eyeballs. Tan protein in the expression of retinal tissue was examined by immunofluorescencal detection. Results The successful establishment of the intraocular hypertension mod-el. The whole amount of the Tan in the intraocular hypertension model decreased to 77.3 % of the controlled ones on the second week and then decreased to 60.4 % on the fourth week. Comparing with the whole amount of Tan, P-Tau was al- most no change on the second week but it increased to 135.4 % of the controlled group on the fourth week, obviously the phosphorylation increased. The influence of the intraocular hypertension of Lithium chloride to the intraocular hypertension model cats： during the fourth week, the whole amount of retina Tan of the Lithium chloride treated group increased signifi- cantly equaling 99% of the controlled eyes. The ratio between the amount of P-tau and the whole Tau decreased obviously. It almost declined to the controlled level. While the intraocular hypertension of the untreated retina group, the whole Tan protein and the phosphorylating Tau protein expression were decreased obviously in every layer. Comparing with the un- treated group,the whole Tau protein and the phosphorylating Tau protein expression of the intraocular hypertension of the Lithium chloride treated retina group increased significantly.Coclusion The continuous stimulating intraocular hyper- tension led to the decreasing of the the whole amount of Tau protein on cats＇ retina and the phosphorylating Tau protein expression increased. The Lithium chloride could reduce Tau protein＇ s overphosphorylation which was caused by lasting in- traocular hypertension.