慢病毒介导生长抑素过表达对大鼠海马电点燃癫痫的抑制作用

Lentiviral vector-mediated somatostatin overexpression suppresses seizures induced in hippocampal kindled rats

目的观察慢病毒介导的神经元特异性生长抑素（somatostatin，SST）过表达对大鼠海马电点燃癫痫的抑制作用。方法成年Sprague—Dawley（sD）大鼠随机分为假手术组（Sham）、癫痫模型组（EP）、空载慢病毒注射癫痫模型组（Lenti—pSyn—EGFP，LV—EGFP）：海马齿状回（dentategyms，DG）部位注射LV—EGFP病毒5μl和SST重组慢病毒注射癫痫模型组（Lenti—pSyn—SST-2A．EGFP，LV—SST）：在海马齿状回、内嗅皮质（medial entorhinal codex，MEC）或杏仁核（amygdala，Amy）注射LV．SST病毒5μl；采用海马电点燃刺激法建立大鼠癫痫模型，观察各组大鼠行为学变化，免疫组化检测大鼠海马和大脑皮质内SST、神经元核蛋白（NeuN）以及微管相关蛋白2（MAP2）的表达变化。结果LV．SST（DG）组、LV—SST（MEC）组及LV—SST（Amy）组首次达到V级癫痫发作电流阈值分别为[（143．8±3．8）μA、（142．5±4．1）μA，（142．5±5．3）μA]，与癫痫组[（136．3±5．3）μA]相比有所增加，且前4轮刺激达到V级的电流值均明显升高（P〈0．05）；癫痫组和SST重组慢病毒注射组（LV—SST）大鼠电点燃后检测发现，在CA1、CA3和DG部位的SST和NeuN阳性表达细胞数均低于Sham组（P〈0．05），其中LV—SST组SST和NeuN表达降低幅度较癫痫组两者降低幅度小（P〈0．05），同时与癫痫组相比，LV—SST组大鼠MAP2的阳性表达较多。结论慢病毒介导的SST过表达对大鼠海马电点燃癫痫发作具有一定的抑制作用，对海马区神经元具有保护作用，为颞叶癫痫基因治疗提供新思路。

Objective To explore the effect of lentiviral vector-mediated somatostatin （SST） ex- pression on seizures induced by hippoeampal kindling in rats. Methods Adult Spragne-Dawley rats were randomly divided into the sham group （Sham）, epilepsy group （EP）, Lenti-pSyn-EGFP （LV-EGFP） group and Lenti-pSyn-SST-2A-EGFP （LV-SST） group.The rats in LV-EGFP group were subsequently electrically hippocampal kindled and LV-EGFP （5 μl） was injected into dentate gyrus （DG）. The rats in LV-SST group were kindled and LV-SST （5 μl） was injected into the dentate gyms （DG）, medial entorhinal cortex （MEC） or amygdala （Amy）. Seizure severity was evaluated and immunohistochemical staining was em- ployed to detect the expression of SST, neuron specific nuclear protein （NeuN） and microtubule associated protein 2 （MAP2）. Results The current values to the first stage V seizure of LV-SST （DG） group, LV-SST （MEC） group or LV-SST （Amy） group （ （143.8±3.8） μA, （ 142.5±4.1 ） μA, （142.5±5.3） μA,respeetive- ly） were significantly increased compared with that of epilepsy （EP） group （（136.3±5.3） μA） , and V stage current values of LV-SST groups in each stimulation day were higher than that of EP group except the fifth stimulation day （P〈0.05）. After kindling, SST expression and NeuN-positive neurons of EP group and LV- SST groups were less than that of Sham group in CA1 ,CA3 and DG. SST and NeuN neurons loss in LV-SST groups were less than that of EP group （P〈 0.05 ） and groups were higher than that in EP group. Conclusion MA192 immunohistochemistry stainings in LV-SST Lentiviral vector-mediated somatostatin expression suppresses seizures and can rescue the neuronal damage of seizure induced by kindling in hippocampus, which may provide a new method of gene therapy for temporal lobe epilepsy.