炎症因子在大鼠脑缺血后MMP和TIMP-1致脑损伤中的作用

Role of Inflammatory Factor in Brain Damage with Cerebral Ischemia Rat Caused by MMP and TIMP-1

【目的】探讨肿瘤坏死因子-α(TNF-α)、白细胞介素1β(IL-1β)、基质金属蛋白酶-3(MMP-3)、基质金属蛋白酶-9(MMP-9)和基质金属蛋白酶抑制剂-1(TIMP-1)在大鼠脑缺血再灌注后的动态变化及特点,阐明TNF-α、IL-1β在脑缺血大鼠MMP和TIMP-1引起脑损伤中的作用。【方法】雄性SD大鼠56只随机分为假手术组和缺血2 h再灌注6、12、24、48、72 h和7 d组。运用线栓法复制大鼠局灶性脑缺血再灌注模型,采用ELISA法测定脑组织和血清TNF-α和IL-1β含量,及脑组织中MMP-3、MMP-9和TIMP-1的含量。【结果】与假手术组比较,血清和脑组织TNF-α和IL-1β含量于缺血再灌注6 h明显增加(4.38±0.73 vs 2.63±0.14、5.28±0.71 vs 3.46±0.47;22.34±3.56 vs 12.13±4.26、9.56±0.85 vs 4.23±0.83;P<0.05),12 h达到高峰,随后各时间点表达开始下降,至7 d与假手术组比较无明显差别。脑组织中MMP-3、MMP-9含量于再灌注6 h开始升高,24 h明显升高(P<0.05),48 h达高峰,随后逐渐下降,至再灌注7 d与假手术组比较无统计学意义,而脑组织中TIMP-1含量在再灌注各时间点均低于假手术组(P<0.05)。且血清和脑组织中TNF-α和IL-1β含量与MMP-3、MMP-9的含量呈明显正相关(P<0.05),与TIMP-1含量呈负相关(P<0.05)。【结论】MMP-3、MMP-9在脑缺血大鼠缺血再灌注早期水平即升高,提示MMP-3和MMP-9在脑缺血再灌注的发病过程中起着重要的作用,炎症因子TNF-α和IL-1β可通过促进脑组织中MMP-3、MMP-9的生成,抑制TIMP-1的生成,进一步加重缺血后脑损伤。

[Objective] To study the content change of TNF-α, IL-1β, MMP-3, MMP-9, and TIMP-1 in the rats after cerebral ischemia and reperfusion. To clarify the role of TNF-α and IL-1β in brain damage with ischemia rat caused by MMP and TIMP-1. [Methods] The 56 male SD rats were randomly divided into sham-operation group and ischemia 2 h reperfusion 6 h, 12 h, 24 h, 48 h, 72 h, 7 d group. The local cerebral ischemia reperfusion model was established by intraluminal thread occlusion of the middle cerebral arteries occlusion （MCAO）, the level of TNF-α, IL-1β, MMP-3, MMP-9, and TIMP-1 were determined by enzyme-linked immunosorbent assay （ELISA）. [Resuhs] Compared with sham-operation group, the content of TNF-αand IL-1β in brain tissue and blood were significantly higher in reperfusion 6 h （4.38 ± 0.73 vs 2.63 ±0.14, 5.28 ± 0.71 vs 3.46 ±0.47; 22.34± 3.56 vs 12.13± 4.26, 9.56 ± 0.85 vs 4.23 ± 0.83; P 〈 0.05）, and reached the peak at the 12th hour after reperfusion, and then fell down. MMP-3 and MMP-9 content increased at the 6th hour after reperfusion. Till the 48th hour it reached the peak, and then fell down. The content of TIMP-1 in brain tissue were significantly lower in reperfusion group than that in the sham-operation group. And the content of TNF-α and IL-1β were positively correlated with MMP-3 and MMP-9 （P 〈 0.05）, negatively correlated with TIMP-1. [ Conclusion] MMP-3 and MMP-9 play an important role in cerebral ischemia-reperfusion injury. Inflammatory factor can increasesthe production of MMP-3 and MMP-9 in brain tissue, decrease the production of TIMP-1, and further promote the brain damage cause by ischemia reperfusion.