微管相关蛋白1轻链3在新生期大鼠惊厥后海马的表达

Expression of microtubule-associated protein 1 light chain 3 following recurrent neonatal seizures in hippocampus

目的 研究新生期大鼠反复惊厥后海马中自噬标记蛋白微管相关蛋白1轻链3（LC3）的表达及3-MA对表达的干预作用.方法 实验在苏州大学衰老与神经疾病实验室进行.日龄6 d的sprague-Dawley大鼠72只随机（随机数字法）分成三组,每组24只,惊厥组每日吸入三氟乙醚诱导惊厥发作5次,每次间隔30 min,连续9 d;对照组同样操作但不吸入三氟乙醚;3-MA组惊厥前腹腔注射3-MA（总量2μL）,同样方法吸入三氟乙醚诱导惊厥,方法同惊厥组.三组大鼠于最后一次惊厥后分别按1.5 h,3 h,6 h,24 h后取海马组织,采用蛋白质免疫印迹技术（western blot）分别检测三组大鼠大脑海马中LC-3的表达.各组LC3蛋白水平采用方差分析进行比较.结果 对照组和3-MA组同一时间点LC3表达差异无统计学意义,惊厥组（1.5 h,3 h,6 h,24 h）海马组织中LC-3的表达明显高于对照组和3-MA组同一时间点LC3表达（F值分别为4.70,5.28,8.51,5.89,P〈0.05）.结论 惊厥后自噬途径被激活,3-MA参与了自噬途径的调控.

Objective To explore the repetitive expressions of autophagy marker protein-microtubule-associated protein 1 light chain 3 （LC3） in hippocampus in newborn rats with recurrent seizure and the influence of 3- methyladeine （3-MA） on LC2 expressions. Method Seventy-two 6-day-old SD rats were randomly （random namber） divided into the recurrent neonatal seizure group （RS group, n = 24）, the 3-MA-treated seizure group （3- MA group, n = 24） and control group （ n = 24）. Rats in RS group were subjected to 55 attacks of seizure induced by flurothyl in 9 successive days from the 6th postnatal day （P6）. In 3-MA group, 2 uL of 3-MA was injected every day till seizure induced. Western blot analysis was used to determine LC3 protein level in hippocampus at different intervals of 1.5 h, 3 h, 6 h and 24 h after the last convulsion. The LC3 protein level was analyzed with Dunnett test after ANOVA. Results LC3 protein levels in RS group at the different intervals were significantly higher than those in the control group and in 3-MA group （ F = 4.70,5.28,8.51 and 5.89, respectively, P 〈 0.05）, and there were no significant differences in LC3 protein level between 3-MA group and control group at those intervals （ P 〉 0.05）. Conclusions The autophagy/lysosomal pathway is immediately activated after recurrent seizure evidenced by the elevated expressions of LC3 in hippocampus. The 3-MA is involved in the regulation of autophagy/ lysosomal pathway by down-regulating the expressions of LC3.