摘要
目的探讨抑制c-Jun氨基末端激酶(JNK)/核转录因子FOXO3a信号通路对缺氧缺血性脑损伤(HIBD)新生大鼠神经元凋亡的保护作用机制。方法将64只7日龄Sprague-Dawley大鼠随机分为假手术组、缺氧缺血(HI)组、二甲基亚砜(DMSO)溶剂组和JNK特异性抑制剂AS601245干预组(JNK抑制剂组)。各组分别在建模后24 h处死动物取大脑皮层,应用Western blot法定量检测JNK、p-JNK、FOXO3a、胞核FOXO3a、胞浆FOXO3a,以及促凋亡蛋白Bim及CC3的表达水平;应用TUNEL染色法检测神经细胞凋亡情况。结果与假手术组相比,HI后24 h,p-JNK蛋白水平增高(P<0.01);胞核FOXO3a蛋白水平增高,胞浆FOXO3a蛋白水平降低(P<0.01);Bim及CC3表达水平增高(P<0.01)。与HI组及DMSO溶剂组相比,JNK抑制剂组p-JNK蛋白水平降低(P<0.01);胞核FOXO3a蛋白水平降低,胞浆FOXO3a蛋白水平增高(P<0.01);Bim及CC3表达水平降低(P<0.01)。JNK抑制剂组的TUNEL染色阳性细胞表达较HI组及DMSO溶剂组减少(P<0.01)。结论新生大鼠HIBD时,JNK发生磷酸化,活性增高;抑制JNK活性可抑制FOXO3a核转位,下调促凋亡蛋白Bim及CC3表达,减少神经细胞凋亡。
Objective To explore the mechanisms of neuroprotective effects of c-Jun N-terminal kinase（JNK）/FOXO3a transcription factor signaling pathway inhibition on hypoxic-ischemic neuronal apoptosis in neonatal rats with hypoxic-ischemic brain damage（HIBD）. Methods Sixty-four 7-day-old Sprague-Dawley rats were divided into four groups： hypoxia-ischemia（HI）, sham-operated, JNK specific inhibitor AS601245-treated, and DMSO vehicle. Rats＇ cerebral cortexes were collected at 24 hours after HI. Western blot was used to detect the protein expression of JNK, p-JNK, FOXO3a, nuclear and cytoplasmic FOXO3a, Bim, and CC3. TUNEL staining was used to detect the apoptotic cells. Results Compared with the sham-operated group, p-JNK protein increased（P0.01）, nuclear protein of FOXO3a increased（P0.01）, cytoplasmic protein decreased（P0.01）, and pro-apoptotic proteins Bim and CC3 increased 24 hours after HI（P0.01）. Compared with the HI and DMSO vehicle groups, p-JNK protein was reduced（P0.01）, nuclear protein of FOXO3a was also reduced（P0.01）, cytoplasmic protein increased（P0.01）, and Bim and CC3 proteins decreased（P0.01） in the AS601245-treated group 24 hours after HI. TUNEL positive cells were reduced in the AS601245-treated rats compared with the HI and DMSO vehicle groups 24 hours after HI（P0.01）. Conclusions JNK activity increases in the neonatal rat brain with HI damage. JNK activity inhibition can inhibit FOXO3a translocation from cytoplasm to nucleus and downregulate the levels of pro-apoptotic proteins Bim and CC3, leading to the reduction of neuronal apoptosis.
出处
《中国当代儿科杂志》
CAS
CSCD
北大核心
2017年第4期458-462,共5页
Chinese Journal of Contemporary Pediatrics
基金
国家自然科学基金(81000262)
四川省卫生和计划生育委员会科研课题(16PJ240)
四川省卫生和计划生育委员会资助项目(140045)
