Zhang Y, Cheng J L, Li Y
Department of First Affiliated Hospital of Zhengzhou University, Zhengzhou 450002, China.
Zhonghua Yi Xue Za Zhi. 2018 Apr 17;98(15):1176-1182. doi: 10.3760/cma.j.issn.0376-2491.2018.15.011.
To investigate the cerebral protective effect of shRNA down-regulated matrix metalloproteinase-9(MMP-9) on cerebral infarction rats. 32 SD rats were randomly divided into four groups (8 for each group): group A (sham operation group): the branches of external carotid artery were only separated and ligated and were not be inserted thread; group B (MCAO group): rat MCAO models were made referring to the conventional Longa method; group C (physiological saline group): rats were injected with 5 μl saline two weeks before MCAO models; group D (lentivirus intervention group): rats were injected with 5 μl lentivirus-mediated shRNA two weeks before MCAO models.The diffusion tensor imaging(DTI) was used to evaluate the tissue of cerebral ischemic of middle cerebral artery occlusion(MCAO) in rats.At 4, 8, 12, 18 and 24 h after MCAO, the ADC value and FA value of the lesion side were calculated.The expression of MMP-9 protein in brain tissue of ischemic side was measured by Western blot, and the expression of MMP-9 protein was observed by paraffin section and immunohistochemistry.SPSS 17.0 software was used for statistical processing, and the difference was statistically significant in <0.05. At 4, 8, 12, 18, 24 h after ischemia, the values of ADC and FA in the ischemic area of the lentivirus intervention group were higher than those in the MCAO group, and the difference was statistically significant (the values of ADC values at different time points were 8.78, 3.30, 3.58, 4.55 and 13.12, respectively <0.05.The values of FA values at different time points were 2.51, 5.87, 6.91, 4.97 and 4.58, respectively <0.05). The expression of MMP-9 protein increased gradually after focal cerebral ischemia.The expression of MMP-9 protein in lentivirus intervention group was lower than MCAO group.The differences were statistically significant at each point ( values at different time points were 3.55, 6.11, 4.67, 4.63 and 2.77, respectively <0.05). Lentivirus mediated shRNA inhibits the expression of MMP-9, reduces the vasogenic edema and plays a protective role in cerebral infarction.Magnetic resonance DTI can monitor dynamically the changes of ischemic area in rats with ischemic cerebral infarction.
探讨shRNA下调基质金属蛋白酶-9（MMP-9）对脑梗死大鼠的脑保护作用。将32只SD大鼠随机分为四组（每组8只）：A组（假手术组）：仅分离并结扎颈外动脉分支，不插入线栓；B组（MCAO组）：参照传统Longa法制作大鼠MCAO模型；C组（生理盐水组）：在制作MCAO模型前两周给大鼠注射5 μl生理盐水；D组（慢病毒干预组）：在制作MCAO模型前两周给大鼠注射5 μl慢病毒介导的shRNA。采用扩散张量成像（DTI）评估大鼠大脑中动脉闭塞（MCAO）脑缺血组织。在MCAO后4、8、12、18和24 h，计算梗死侧的表观扩散系数（ADC）值和各向异性分数（FA）值。采用蛋白质免疫印迹法检测缺血侧脑组织中MMP-9蛋白的表达，通过石蜡切片和免疫组织化学观察MMP-9蛋白的表达情况。采用SPSS 17.0软件进行统计学处理，差异有统计学意义为P <0.05。缺血后4、8、12、18、24 h，慢病毒干预组缺血区的ADC值和FA值均高于MCAO组，差异有统计学意义（不同时间点ADC值分别为8.78、3.30、3.58、4.55和13.12，P <0.05；不同时间点FA值分别为2.51、5.87、6.91、4.97和4.58，P <0.05）。局灶性脑缺血后MMP-9蛋白表达逐渐增加，慢病毒干预组MMP-9蛋白表达低于MCAO组，各时间点差异均有统计学意义（不同时间点P值分别为3.55、6.11、4.67、4.63和2.77，P <0.05）。慢病毒介导的shRNA抑制MMP-9表达，减轻血管源性水肿，对脑梗死起保护作用。磁共振DTI可动态监测缺血性脑梗死大鼠缺血区的变化。
