TSA对发育期大鼠癫痫后脑损伤的保护作用及其机制

The Protection Effects and Mechanisms of TSA on Seizures-Induced Brain Damage in Developing Rat

目的 探讨组蛋白去乙酰化酶抑制剂曲古抑素A（TSA）在癫痫后脑损伤发病中的作用及其机制。方法 将32只雄性SD大鼠随机分为4组：对照组、海人酸（KA）组、小剂量TSA干预组（0.03 mg/kg）及大剂量TSA干预组（0.1 mg/kg）组,通过腹腔注射海人酸（KA）制作发育期大鼠癫痫模型,TSA于KA诱导癫痫前2 h腹腔注射给药,评估惊厥发作的等级及记录惊厥的潜伏期。癫痫后24 h处死大鼠,HE染色观察脑组织病理变化;TUNEL染色检测大鼠海马神经元细胞凋亡;CD68染色检测活化的小胶质细胞;Western blot检测IL-1β和TNF-α蛋白的表达。结果 KA组均达到Ⅳ-Ⅴ级惊厥发作,而TSA干预组能减轻惊厥发作的等级和延长惊厥的潜伏期。HE染色可见KA组明显的神经元凋亡及细胞水肿,伴有较多的炎症细胞浸润,而TSA干预组能减轻神经元凋亡及细胞水肿,同时减少炎症细胞浸润。与对照组比较,KA组神经元凋亡数、小胶质细胞活化数及炎症因子的表达均显著增加（P〈0.05）,而TSA能抑制KA诱导的改变。相对于0.03 mg/kg TSA干预组,0.1 mg/kg TSA干预组治疗作用更明显（P〈0.05）。结论 TSA能抑制癫痫后海马神经元凋亡、小胶质细胞活化及炎症因子的表达,同时能减轻惊厥发作的等级和延长惊厥的潜伏期,从而对癫痫后脑损伤起到保护作用。

Objective This study aimed to investigate the protection effects and mechanisms of Histone deacetylase inhibitor （HDACi） TSA on seizure-induced brain damage of developing rats. Methods 32 male Sprague-Dawley （SD） rats were randomly divided into 4 groups：Control group, KA group,0.03 mg/kg TSA treated group and 0.1 mg/kg TSA treated group.Intraperitoneal administration of KA induced rat seizures.TSA was injected intraperitoneally 2 hours before KA injection.The seizure stage and seizure latency were recorded after KA injection. Hippocampus tissues were sampled at 24 hours after seizures.Brain tissue pathological changes were observed by HE staining;Apoptotic neuron were observed using TUNEL immunohistochemical staining;Activated microglia were detected by CD68 mmunohistochemical staining;IL-1β and TNF-α protein were detected using Western Blot. Results The brain tissue pathological changes, apoptosis of neurons, activated microglia, IL-1β and TNF-α protein and seizure latency significantly increased after KA treatment （P〈0.05）, but these effects were attenuated by adding TSA.Compared with 0.03 mg/kg TSA treated group, 0.1 mg/kg TSA treated group plays a more important role in protecting against seizure-induced brain damage. Conclusions Histone deacetylase inhibitor TSA can reduce brain tissue pathological changes, apoptosis of neurons, activated microglia and inflammation factor.This suggests a protective effect against brain damage associated with seizures in developing rats.