小鼠脑外伤模型中Nrf2与泛素-蛋白酶体系统的关系  

Nrf2 and the ubiquitin proteasome system in the mouse model of traumatic brain injury

作　　者：丁惠[1] 王汉东[1] 朱林[1] 韦武亭 吴永[1] 丁可[1] 

机构地区：[1]南方医科大学金陵医院(南京军区南京总医院)神经外科,南京210002

出　　处：《医学研究生学报》2016年第5期475-479,共5页Journal of Medical Postgraduates

基　　金：国家自然科学基金(81371357)

摘　　要：目的 Nrf2是重要的神经保护因子,泛素-蛋白酶体系统(ubiquitin proteasome system,UPS)作为一种高度特异性的细胞内蛋白降解途径,在维持基因和蛋白正常功能上发挥着重要的作用。文中初步研究脑外伤模型中Nrf2与UPS的关系。方法 42只健康雄性ICR小鼠随机数字表法分为3组:对照组,外伤+溶剂组,外伤+莱菔硫烷组,每组14只;12只Nrf2基因敲除小鼠为外伤+敲除组。外伤组采用自由落体法制备闭合性小鼠脑损伤模型,对照组仅切开头皮。外伤+莱菔硫烷组于造模后5 min予以腹腔注射莱菔硫烷5 mg/kg;外伤+溶剂组于造模后5 min予以腹腔注射同等体积的10%玉米油;造模24 h后取脑皮层,Western blot检测Nrf2、泛素化蛋白含量,同时用免疫组化、电镜分别观察Nrf2和泛素化蛋白的变化。结果与对照组相比,外伤+溶剂组中Nrf2核蛋白与泛素化蛋白表达含量均增高[(0.66±0.09)vs(0.09±0.02),(10.58±0.75)vs(3.27±0.21)],差异均有统计学意义(P<0.05);与外伤+溶剂组相比,外伤+莱菔硫烷组中核蛋白Nrf2表达明显增高[(1.22±0.14)vs(0.66±0.09)],泛素化蛋白含量则明显降低[(6.97±0.86)vs(10.58±0.75)],差异均有统计学意义(P<0.05);而外伤+敲除组中核蛋白Nrf2表达明显低于外伤+溶剂组[(0.17±0.02)vs(0.66±0.09)],泛素化蛋白含量则显著高于外伤+溶剂组[(14.35±0.65)vs(10.58±0.75)],差异均有统计学意义(P<0.05)。免疫组化和电镜也观察到相应的泛素化蛋白的变化。结论脑外伤模型中Nrf2可能通过调节UPS来发挥保护作用。Objective Nrf2 is an important neuroprotective factor and the ubiquitin proteasome system（ UPS）,as a highly specific intracellular protein degradation pathway,plays an important role in maintaining gene and protein functions. This paper presents a preliminary study on the relationship between Nrf2 and the ubiquitin proteasome system in the mouse model of traumatic brain injury（ TBI）. Methods Forty-two healthy male ICR mice were randomly divided into three groups： control,TBI ＋ sulforaphane（ SFN） and TBI ＋ vehicle,and 12 Nrf2-knockout mice were included in the TBI ＋ Nrf2- /-group. The animals of the TBI ＋ SFN group were treated with SFN while those of the TBI ＋ vehicle group with the same volume of 10% corn oil at 5 minutes after TBI. At 24 hours after TBI,brain samples were collected from the mice for determining the Nrf2 expression and ubiquitinated protein content by Western blot and the changes in the Nrf2 and ubiquitinated proteins were observed by immunohistochemistry and electron microscopy.Results Compared with the controls,the mice in the TBI ＋ vehicle group showed significantly increased expressions of Nrf2（ 0. 09 ±0. 02 vs 0. 66 ± 0. 09,P﹤0. 05） and ubiquitinated proteins（ 3. 27 ±0. 21 vs 10. 58 ± 0. 75,P﹤0. 05）. In comparison with animals in the TBI ＋ vehicle group,those in the TBI ＋ SFN group exhibited a significant increase in the Nrf2 protein level（ 0. 66 ± 0. 09 vs 1. 22 ± 0. 14,P﹤0. 05） but a decrease in the ubiquitinated protein level（ 10. 58 ± 0. 75 vs 6. 97 ± 0. 86,P﹤0. 05）,and those in the TBI ＋ Nrf2- /-group showed a markedly decreased expression of the Nrf2protein（ 0. 66 ± 0. 09 vs 0. 17 ± 0. 02,P﹤0. 05） but increased expression of the ubiquitinated protein（ 10. 58 ± 0. 75 vs 14. 35 ±0. 65,P﹤0. 05）. Similar results were observed by immunohistochemistry and electron microscopy. Conclusion Nrf2 played a neuroprotective role in the mouse model of traumatic brain injury by regulating the ubiquitin proteasome system.

关 键 词：NRF2 泛素-蛋白酶系统 颅脑外伤 

分 类 号：R651.1[医药卫生—外科学]