局部亚低温对大鼠脑缺血再灌注基质金属蛋白酶9及细胞外基质蛋白表达的影响  

Local mild hypothermia influences the expression of matrix metalloproteinase 9 and extracellular matrix proteins in a rat model of ischemia and reperfusion injury

作　　者：李芳[1,2] 刘向荣[2] 闫峰[2] 张陈诚[2] 罗玉敏[2] 方伯言[3] 吉训明[2] 

机构地区：[1]辽宁医学院研究生院,辽宁锦州121001 [2]首都医科大学宣武医院脑血管病研究室,北京100053 [3]航天中心医院神经内科,北京100049

出　　处：《首都医科大学学报》2013年第1期58-63,共6页Journal of Capital Medical University

基　　金：国家自然科学基金资助项目(81171241;81200913)~~

摘　　要：目的研究局部亚低温对大鼠脑缺血再灌注损伤时基质金属蛋白酶9(metalloproteinase 9,MMP9)、细胞外基质蛋白———层黏连蛋白(laminin,LN)和纤维连接蛋白(fibronectin,FN)表达的影响,为局部亚低温应用于脑缺血的临床治疗提供理论依据。方法改良线栓法制作大鼠右侧大脑中动脉缺血再灌注模型,脑缺血时间为2 h,缺血即刻于大鼠头部放置冰块,脑温维持在32.5℃～33.5℃,并持续至再灌后1 h。采用12分评分法与2,3,5-氯化三苯基四氮唑染色法进行神经功能评分和脑梗死体积测定;免疫荧光方法测定检测缺血半暗带MMP9、LN及FN的表达。结果与正常体温再灌注组比较,局部亚低温再灌注组脑梗死体积百分比和神经功能评分均减小(P<0.01);脑组织MMP9表达降低(P<0.05),LN及FN表达升高(P<0.05)。结论在大鼠脑缺血再灌注损伤中,局部亚低温能够明显减小脑梗死体积,改善神经功能。局部亚低温可能通过减少MMP9的表达,增加LN及FN的表达发挥神经保护作用。Objective To investigate the effects of local mild hypothermia on expression of matrix metalloproteinase 9 （MMP9）, extracellular matrix proteins laminin （LN） and fibronectin （FN） in a rat model of ischemia/reperfusion（I/R） injury. Methods Ischemia and reperfusion injury was produced in Sprague Dawley rats with modified suture-occlusion method. The ischemia caused by suture was persisted for two hours in the bodies of rat I/R injury models then the suture was removed. These I/R injury models were randomly assigned into the normothermia group and hypothermia group. Ice was placed under the heads of rats of the local hypothermia group and the cooling lasted for 1 h after reperfusion. Groups of normothermia and hypothermia were further divided into six subgroups with 4 h （N-4 h group and H-4 h group）, 24 h （N-24 h group and H-24 h group）, 72 h （N-72 h group and H-72 h group） of reperfusion, respectively. 2,3,5-triphenyltetrazolium chloride （TTC） staining was applied to measure the cerebral infarction volume, and the neurological deficits scores stood for the neurological function in N-24 h group and H-24 h group. Expression of MMP9, LN and FN were detected with immunofluorescence in ischemic penumbra of all groups. Results The percentage of cerebral infarction volume of H-24 h group was less than that of N-24 h group （P〈0.01）. Compared with N-24 h group, the neurological deficits scores of H-24 h group declined significantly （P〈0.01）. The expression of LN and FN of H-4 h group significantly increased versus N-4 h group （P〈0.05）. MMP9 reduced in the groups of H-4 h and H-24 h when matched with groups of N-4 h and N-24 h, respectively （P〈0.05）. ConclusionLocal mild hypothermia can significantly reduce the cerebral infarct volume and ameliorate the neurological dysfunction in rat I/R injury models. And it can diminish the expression of MMP9 and attenuate the loss of LN and FN. These findings indicated that MMP9, LN and FN may be involved in the protective mechanism

关 键 词：脑缺血再灌注 亚低温 基质金属蛋白酶9 层黏连蛋白 纤维连接蛋白 

分 类 号：R743.31[医药卫生—神经病学与精神病学]