基质金属蛋白酶9在血管性认知功能障碍中的作用和机制

发布时间：2018-04-21 06:15

本文选题：卒中后认知功能障碍 + 基质金属蛋白酶9　；参考：《郑州大学》2017年博士论文

【摘要】：背景:卒中后认知功能障碍(Post-stroke cognitive impairment,PSCI)是脑卒中(缺血性或出血性)后继发的认知功能减退,临床治疗效果差,严重影响脑卒中患者的预后和生活质量,对该病的早期发现和干预是治疗关键,但由于PSCI起病隐匿,早期不易被察觉和诊断,因此急需一种有效的生物学指标来辅助早期诊断。基质金属蛋白酶9(Matrix metallprotenaine 9,MMP9)生理状态下参与调控海马突触可塑性和学习记忆过程,病理状态下参与细胞外基质破坏、炎症浸润和血脑屏障破坏,在动脉粥样硬化、缺血性脑损伤及血管性痴呆中表达增高,因此,PSCI中MMP9表达水平及与认知功能减退可能存在一定关系;另外,MMP9/C1562T(rs3918242)基因多态性与动脉粥样硬化、缺血性脑梗死的发生有关,有必要进一步探讨MMP9/C1562T(rs3918242)基因多态性与PSCI发生的关系,为早期干预提供依据。目的:1.筛查PSCI在脑梗死急性期和恢复期发生情况及可能的危险因素,2.明确MMP9/C1562T(rs3918242)基因多态性与脑梗死及PSCI的发病关系,3.确定血清MMP9水平对缺血性脑卒中患者认知功能的影响以及不同部位梗死认知域受损的差异。方法:1.连续登记2013年5月至2016年9月在新乡医学院第一附属医院神经内科就诊的缺血性脑卒中患者,收集临床资料及各种脑血管疾病危险因素,所有患者均完成相关检查,所有纳入患者均同意登记临床资料、认知功能评估、抽血及定期随访。2.按照卒中后认知功能障碍筛查流程分别在发病2周和3月两个时间节点进行认知功能筛查,对缺血性脑卒中继发认知功能障碍的患者进行详细认知功能评估,并抽血备检。3.采用PCR-限制性内切酶技术及琼脂糖凝胶电泳技术对最终入组患者进行MMP9/C1562T(rs3918242)基因多态性分型,统计各基因型频率;采用酶联免疫吸附试验检测样本中MMP9浓度。结果:1.PSCI在卒中后2周发病率为7.9%(61/769),卒中后3月发病率25.59%(151/590),总发病率27.57%(212/769)2.PSCI组与认知正常脑梗死组在神经功能缺损程度比较显示,两组之间NIHSS评分无显著性差异(P0.05);按照TOAST分型各类型构成比两组之间比较无显著性差异(P0.05)。3.脑血管疾病危险因素多因素分析显示,高同型半胱氨酸血症分别增加了脑梗死(P0.01)和PSCI(P0.01)的发病风险;OSAS增加了脑梗死的发病风险(P0.01),但是对于PSCI的发病风险无统计学意义(P0.05);糖尿病虽增加了脑梗死以及PSCI的风险,但均不具有统计学意义(P0.05)。4.MMP9/C1562T(rs3918242)基因位点突变对脑梗死的发生具有统计学意义(χ2=10.35,P0.01)。其中CC基因型对脑梗死发病的风险具有统计学意义(OR=4.06,95%CI:1.49-11.11,P0.01),提示CC基因型是脑梗死发生的危险因素。而且C等位基因频率分布差异与脑梗死的发生具有统计学意义(OR=0.59,95%CI:0.42-0.82,P0.01)。但MMP9/C1562T(rs3918242)基因位点突变对PSCI的发生不具有统计学意义(χ2=4.43,P0.05)5.三组受试者血清MMP9浓度比较显示,差别具有统计学意义(P0.05)。组间比较显示PSCI组明显高于脑梗死组(P0.05)和正常对照组(P0.01),差别具有统计学意义;认知正常脑梗死患者血清MMP9浓度也明显高于正常对照组,差别具有统计学意义(P0.01)。6.认知功能缺损程度危险因素分析:三组受试Mo CA分值与糖尿病、高同型半胱氨酸血症及MMP9进行偏相关性分析显示,Mo CA分值与空腹血糖值(P0.05)、血同型半胱氨酸水平(P0.01)显著负相关,具有统计学意义(P0.01)。而且血清MMP9水平与空腹血糖值(P0.05)、血同型半胱氨酸水平(P0.01)、NIHSS评分(P0.01)呈正相关,具有统计学意义。血清MMP9水平、NIHSS评分与Mo CA分值均不相关(P0.05)。7.PSCI患者在视空间能力(P0.01)、执行功能(P0.01)及计算力(P0.05)3个认知领域受损严重,而在学习记忆、注意力、语言功能和定向力几个认知域受损不明显(P0.05)。8.PSCI组患者额叶(P0.01)及基底节区(P0.01)部位梗死所占比例明显升高,差异具有统计学意义。而在枕叶(P0.05)及脑干(P0.05)部位梗死所占比例明显减少,差异具有统计学意义。额叶梗死患者在视空间能力(P0.05)、语言功能(P0.05)、执行功能(P0.05)下降明显,而基底节区梗死在学习记忆(P0.05)和计算力(P0.05)方面下降明显。结论:1.MMP9/C1562T(rs3918242)基因多态性与脑梗死的发病密切相关,C等位基因是脑梗死发病的危险因素;MMP9/C1562T(rs3918242)基因多态性与脑梗死后是否出现认知功能障碍关系不明显。2.血清MMP9水平在PSCI中明显升高,血清同型半胱氨酸水平可作为评估PSCI认知功能损害程度的间接指标。3.额叶和基底节区脑梗死更容易出现认知功能障碍,额叶梗死患者在视空间能力、语言功能、执行功能下降明显,而基底节区梗死的患者在学习记忆和计算力方面下降明显。背景:海马神经元突触后膜NMDA受体被激活后可调控突触后膜钙离子通道,介导钙离子内流,参与了学习记忆的形成和突触功能可塑性。有研究证实,MMP9可通过激活海马CA1区NMDA受体,提高CA3-CA1神经传导通路长时程增强(Long-term potentiation,LTP),改善神经突触可塑性,促进学习记忆。但是在血管性痴呆或血管性认知功能障碍小鼠模型中,发现海马CA1区MMP9表达增高,因此,MMP9/NMDA受体通路在低灌注脑损伤后认知功能障碍中的作用需要深入探讨。目的:探讨MMP9/NMDA受体通路在血管性认知功能障碍中对LTP的作用及机制。方法:1.采用双侧颈动脉结扎方法制作慢性大脑低灌注模型,采用水迷宫自动记录仪评估模型鼠学习记忆能力。2.应用场电位记录系统分析记录海马离体脑片CA3/CA1通路LTP变化。3.通过调控MMP9浓度及NMDA受体活性研究MMP9/NMDA受体通路对LTP的作用和机制。结果:1.慢性大脑低灌注小鼠海马LTP受损(P0.01),学习记忆能力下降(P0.01)。2.外源性MMP9提高了正常小鼠海马CA1区LTP(P0.01),在慢性大脑低灌注脑损伤中,MMP9可加重VCI后LTP的损害(P0.01),应用MMP9抑制剂或NMDA受体拮抗剂分别作用于VCI小鼠海马脑片,可使受损的LTP提高(P0.01)。3.同时应用MMP9抑制剂和NMDA受体拮抗剂作用于VCI小鼠海马脑片使LTP提高程度大于二者分别应用之和(P0.05)。结论:生理状态下MMP9激活NMDA受体,有助于增强LTP,改善突触可塑性,提高学习记忆;慢性大脑低灌注后引起的VCI小鼠中MMP9过度激活了NMDA受体,使海马CA3-CA1区LTP减弱,损害突触可塑性,导致学习记忆受损。
[Abstract]:Background: Post-stroke cognitive impairment (PSCI) is a secondary cognitive impairment after stroke (ischemic or hemorrhagic). The effect of clinical treatment is poor, which seriously affects the prognosis and quality of life of stroke patients. Early detection and intervention of this disease is the key to treatment, but because of PSCI onset, the early stage is not. It is easy to be detected and diagnosed, so an effective biological indicator is urgently needed to assist early diagnosis. The physiological state of matrix metalloproteinase 9 (Matrix metallprotenaine 9, MMP9) is involved in the regulation of hippocampal synaptic plasticity and learning and memory process, in pathological condition, involvement of extracellular matrix damage, inflammatory infiltration and blood brain barrier damage, in porridge There is a certain relationship between the expression level of MMP9 in PSCI and the impairment of cognitive function. In addition, the polymorphism of MMP9/C1562T (rs3918242) gene is related to atherosclerosis and ischemic cerebral infarction. It is necessary to further explore the polymorphism of MMP9/C1562T (rs3918242) gene. The relationship between sex and PSCI in order to provide evidence for early intervention. Objective: 1. screening of PSCI in acute and Convalescent Cerebral Infarction and possible risk factors. 2. the relationship between MMP9/C1562T (rs3918242) gene polymorphism and cerebral infarction and PSCI, and 3. to determine the effect of serum MMP9 level on cognitive function of ischemic stroke patients Methods: 1. patients with ischemic stroke in the Department of Neurology, First Affiliated Hospital of Xinxiang Medical College, were registered from May 2013 to September 2016. Clinical data and risk factors of various cerebrovascular diseases were collected and all patients were completed. All the patients agreed to register. Bed data, cognitive function assessment, blood extraction, and regular follow-up.2. were screened for cognitive function at two time nodes of 2 weeks and March respectively according to the post-stroke cognitive dysfunction screening process, and a detailed cognitive function assessment was performed for patients with secondary cognitive dysfunction secondary to ischemic stroke, and PCR- restrictive endonuclease was used for.3.. Techniques and agarose gel electrophoresis were used for the MMP9/C1562T (rs3918242) polymorphism of the final group, and the frequency of each genotype was counted. The MMP9 concentration in the sample was detected by ELISA. Results: the incidence of 1.PSCI was 7.9% (61/769) at 2 weeks after stroke and 25.59% (151/590) after stroke in March, and the total incidence rate was 27.57%. 212/769) in the group 2.PSCI and the cognitive normal cerebral infarction group, there was no significant difference in the degree of neural function defect between the two groups (P0.05), and there was no significant difference between the types of TOAST types and the two groups (P0.05), the multiple factor analysis of the risk factors of.3. cerebrovascular disease showed that hyperhomocysteinemia increased respectively. The risk of cerebral infarction (P0.01) and PSCI (P0.01) was added; OSAS increased the risk of cerebral infarction (P0.01), but there was no statistical significance for the risk of PSCI (P0.05); diabetes increased the risk of cerebral infarction and PSCI, but did not have statistical meaning (P0.05).4.MMP9/C1562T (rs3918242) mutation to cerebral infarction. There were statistical significance (x 2=10.35, P0.01). Among them, the CC genotype was statistically significant (OR=4.06,95%CI:1.49-11.11, P0.01), suggesting that the CC genotype was a risk factor for cerebral infarction, and the difference in the frequency distribution of C alleles was statistically significant (OR=0.59,95%CI:0.42-0.82, P). 0.01). But the mutation of MMP9/C1562T (rs3918242) gene loci did not have statistical significance to the occurrence of PSCI (x 2=4.43, P0.05) 5. three groups, the serum MMP9 concentration comparison showed that the difference was statistically significant (P0.05). The comparison between groups showed that PSCI group was significantly higher than the cerebral infarction group (P0.05) and normal control group (P0.01), the difference was statistically significant. The serum MMP9 concentration in the patients with normal cerebral infarction was also significantly higher than that in the normal control group, and the difference was statistically significant (P0.01).6. cognitive impairment risk factors analysis: three groups of subjects Mo CA score and diabetes, hyperhomocysteinemia and MMP9 partial correlation analysis showed that the Mo CA score and fasting blood glucose (P0.05), blood same type The significant negative correlation of cysteine level (P0.01) was statistically significant (P0.01). The serum MMP9 level was positively correlated with the fasting blood glucose (P0.05), blood homocysteine level (P0.01) and NIHSS score (P0.01). The serum MMP9 level was not related to the Mo CA score (P0.05) in the visual space ability ( P0.01), 3 cognitive domains of executive function (P0.01) and computing power (P0.05) were severely damaged, while in the cognitive domains of learning, memory, attention, language function and orientation (P0.05), the proportion of the frontal lobe (P0.01) and the basal ganglia (P0.01) site of the.8.PSCI group was significantly increased, and the difference was statistically significant. In the occipital lobe (P0.05), the difference was statistically significant. The proportion of infarcts in the brain stem (P0.05) site was significantly reduced, and the difference was statistically significant. The patients with frontal lobe infarction were significantly decreased in visual space ability (P0.05), language function (P0.05) and executive function (P0.05), while basal ganglia infarction decreased in learning memory (P0.05) and calculation force (P0.05). Conclusion: 1.MMP9/C1562T (rs3918242) gene is more than that of P0.05 (rs3918242) gene. State sex is closely related to the onset of cerebral infarction. C allele is a risk factor for cerebral infarction. The relationship between MMP9/C1562T (rs3918242) gene polymorphism and cognitive impairment after cerebral infarction is not obvious. The level of.2. serum MMP9 is significantly increased in PSCI. Serum homocysteine level can be used to evaluate the degree of impairment of PSCI cognitive function. Cognitive impairment is more likely to occur in the frontal lobe and the basal ganglia infarction. The patients with frontal lobe infarction have a significant decline in visual spatial ability, language function, and executive function, while the patients with basal ganglia infarction decrease in learning and memory and computational power. Background: the NMDA receptor in the hippocampal neurons of the hippocampal neurons can be regulated after the activation of the postsynaptic membrane. The postsynaptic membrane calcium channel, which mediates calcium ion influx, participates in the formation of learning and memory and the plasticity of synaptic function. Some studies have shown that MMP9 can enhance the long term enhancement (Long-term potentiation, LTP) of the CA3-CA1 nerve conduction pathway by activating the NMDA receptor in the hippocampus CA1 region, improving the plasticity of synapse and promoting learning and memory. In the mice model of vascular dementia or vascular cognitive impairment, the expression of MMP9 in the CA1 region of the hippocampus is increased. Therefore, the role of MMP9/NMDA receptor pathway in cognitive dysfunction after low perfusion brain injury needs to be explored. Objective: To explore the role and mechanism of MMP9/NMDA receptor pathway to LTP in vascular cognitive impairment. Methods: 1. The model of chronic cerebral hypoperfusion was made with bilateral carotid artery ligation. The learning and memory ability of model rats was evaluated by water maze automatic recorder (.2.). The field potential recording system was used to record the LTP change of CA3/CA1 pathway in the brain slices of the hippocampus. The effect of MMP9/NMDA receptor pathway on LTP by regulating the concentration of MMP9 and the activity of NMDA receptor was studied and the effect of MMP9/NMDA receptor pathway on LTP was studied. Results: 1. the hippocampal LTP damage in chronic cerebral hypoperfusion mice (P0.01), learning and memory ability decreased (P0.01).2. exogenous MMP9 increased the CA1 region LTP (P0.01) in normal mice hippocampus. In chronic cerebral hypoperfusion brain injury, MMP9 could aggravate VCI LTP damage after VCI (P0.01). Hippocampal slices can make the damaged LTP increase (P0.01).3. and use MMP9 inhibitors and NMDA receptor antagonists to act on VCI mouse hippocampal slices to make LTP increase more than two, respectively, and (P0.05). Conclusion: MMP9 activation NMDA receptor in physiological state helps to enhance LTP, improve synaptic plasticity, improve learning and memory; chronic brain low After reperfusion, MMP9 overactivates NMDA receptor in VCI mice, resulting in the weakening of LTP in CA3-CA1 area and damage of synaptic plasticity, resulting in impaired learning and memory.

【学位授予单位】：郑州大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：R749.13

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