甲状腺激素对大鼠脑缺血再灌注损伤后NF-κB与TNF-α表达的影响

发布时间：2018-11-17 06:39

【摘要】：研究背景缺血性脑血管病是一种发病率高、致残率高、死亡率高的三高疾病,严重威胁着人类的健康并影响着生活质量。近年来关于缺血性脑血管病的治疗主要有动静脉溶栓、机械取栓等,主要目的是为了及时再通血流,挽救缺血半暗带。血管再通后虽使组织细胞重新获得了新鲜的血流,避免了进一步的缺血缺氧,但随之而带来的缺血再灌注损伤问题也是目前最突出且研究热门的问题。缺血再灌注损伤是指当组织重新获得血流后,组织器官不仅没有得到好转,反而出现新的损伤。缺血再灌注损伤涉及了多种复杂的病理过程,炎症反应是参与其中重要的病理机制之一,其最终作用结果可导致神经元损伤死亡。炎性因子核转录因子(nuclear factor-kappa B,NF-κB)、肿瘤坏死因子(tumor necrosis factor,TNF-α)在脑缺血后容易表达,以此做为观察指标,可以较好的模拟人体内脑缺血的病理生理过程。我们知道,甲状腺激素对中枢神经系统的发育具有不可忽视的影响。但目前关于甲状腺激素对缺血再灌注损伤(Ischemic-reperfusion,IR)作用的报道相对较少。本实验通过制作大鼠大脑中动脉闭塞(middle cerebral artery occlusion,MCAO)模型,观察了甲状腺激素(Triiodothyronine,T3)对缺血再灌注后炎性因子NF-κB、TNF-α表达的影响,探讨了甲状腺激素在炎症反应通路中的作用,为脑血管病的治疗提供了新思路。研究目的探讨甲状腺激素(T3)对大鼠脑缺血再灌注损伤(IR)后缺血侧皮质NF-κB、TNF-α表达的影响。研究方法将96只健康成年SD雄性大鼠随机分为假手术组、假手术+T3组、IR组、IR+T3组,采用改良线栓法制作大鼠大脑中动脉缺血2h再灌注模型,假手术+T3组及IR+T3组在造模后1h再灌注后6h分别腹腔注射甲状腺激素l0 ug/100 g,其余两组分别腹腔注射等量生理盐水。在大鼠麻醉苏醒后24h,根据Longa5分制法对其进行神经功能评分,于再灌注24h后取脑组织。用2,3,5-氯化三苯基四氮唑(2,3,5-Triphenyltetrazolium chloride,TTC)染色法检测大鼠脑梗死灶的面积百分比,HE染色法观察脑组织的病理结构的改变。采用实时荧光定量PCR(Real-Time PCR)法检测大鼠缺血侧皮质NF-κB mRNA、TNF-αmRNA的表达水平,免疫组化染色法检测缺血侧皮质NF-κB、TNF-α蛋白表达变化。结果1.IR+T3组大鼠的神经功能评分及脑梗死灶面积百分比较IR组的明显降低(P0.05)。2.HE染色结果显示IR+T3组大鼠脑组织病理损伤较IR组明显减轻。3.Real-time PCR及免疫组织化学结果显示,假手术组、假手术+T3组大鼠缺血侧皮质NF-κB mRNA、TNF-αmRNA及其蛋白表达量无明显差异。与假手术组相比,IR组大鼠缺血侧皮质NF-κB mRNA、TNF-αmRNA及其蛋白表达量显著增多(P0.05);与IR组相比,IR+T3组大鼠NF-κB mRNA、TNF-αmRNA及其蛋白表达量显著减少(P0.05)。结论1.甲状腺激素对大鼠脑缺血再灌注损伤具有保护作用。2.甲状腺激素的保护作用是通过下调炎性因子NF-κB、TNF-α的表达来实现的。
[Abstract]:Background Ischemic cerebrovascular disease (ICVD) is a kind of three high diseases with high morbidity, high disability rate and high mortality rate. It is a serious threat to human health and affects the quality of life. In recent years, the treatment of ischemic cerebrovascular disease mainly includes arteriovenous thrombolysis, mechanical thrombolysis and so on. The main purpose is to recanalize the blood flow and save the ischemic penumbra in time. Although the tissue cells can get fresh blood flow again and avoid further ischemia and hypoxia after vascular recanalization, the problem of ischemia reperfusion injury is also the most prominent and hot issue at present. Ischemia-reperfusion injury refers to the new injury of tissue and organ after the tissue regains blood flow. Ischemia-reperfusion injury involves a variety of complex pathological processes, inflammatory response is one of the important pathological mechanisms involved, and the final result can lead to the death of neurons. The expression of nuclear factor-kappa BNF- 魏 B), tumor necrosis factor (tumor necrosis factor,TNF- 伪) is easy after cerebral ischemia, which can be used as an index to simulate the pathophysiological process of cerebral ischemia in human body. Thyroid hormones are known to have an important effect on the development of the central nervous system. However, there are few reports about the effect of thyroid hormone on ischemia reperfusion injury (Ischemic-reperfusion,IR). The effect of thyroid hormone (Triiodothyronine,T3) on the expression of inflammatory factor NF- 魏 B (TNF- 伪) in rats with middle cerebral artery occlusion (MCAO) was studied. To explore the role of thyroid hormone in inflammatory response pathway and provide a new idea for the treatment of cerebrovascular disease. Objective to investigate the effect of thyroid hormone (T 3) on the expression of NF- 魏 B tNF- 伪 in ischemic cortex of rats after cerebral ischemia reperfusion injury (IR). Methods 96 healthy adult SD male rats were randomly divided into three groups: sham operation group, T3 group, IR group and IR T3 group. Thyroid hormone 10 ug/100 g was injected intraperitoneally in group T3 and IR group 6 h after reperfusion, and the other two groups were injected with the same amount of normal saline respectively. At 24 hours after anaesthesia, the rats were graded according to Longa5 score and brain tissues were taken after 24 h reperfusion. The area percentage of cerebral infarction in rats was detected by using the method of 2ttriphenyl 5-triphenyltetrazolium chloride,TTC staining, and the pathological structure of brain tissue was observed by HE staining. The expression of NF- 魏 B mRNA,TNF- 伪 mRNA in ischemic cortex of rats was detected by real-time fluorescence quantitative PCR (Real-Time PCR), and the expression of NF- 魏 B mRNA,TNF- 伪 protein in ischemic cortex was detected by immunohistochemical staining. Results the scores of neurological function and the percentage of cerebral infarction area in 1.IR T3 group were significantly lower than those in IR group (P0.05). The results of 2.HE staining showed that the pathological damage of brain tissue in IR T3 group was significantly less than that in IR group. Real-time PCR and immunohistochemical results showed that, There was no significant difference in the expression of NF- 魏 B mRNA,TNF- 伪 mRNA and its protein in ischemic cortex between sham-operated group and T3 group. Compared with sham operation group, the expression of NF- 魏 B mRNA,TNF- 伪 mRNA and its protein in ischemic cortex of IR group was significantly increased (P0.05). Compared with IR group, the expression of NF- 魏 B mRNA,TNF- 伪 mRNA and its protein decreased significantly in IR T3 group (P0.05). Conclusion 1. Thyroid hormone has protective effect on cerebral ischemia-reperfusion injury in rats. 2. The protective effect of thyroid hormone is achieved by down-regulating the expression of inflammatory factor NF- 魏 B, TNF- 伪.
【学位授予单位】：郑州大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：R743

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