基质金属蛋白酶-9与脑梗死关系的研究进展

基质金属蛋白酶-9（MMP-9）是一种锌依赖的蛋白水解酶并可特异性的降解细胞外基质。脑梗死急性期MMP-9的表达显著增加并参与了血脑屏障的破坏、血管源性水肿、缺血再灌注及出血性转化等病理过程,且其血浆水平与脑梗死面积、神经功能缺损程度及溶栓后出血转化等显著相关。现就MMP-9与脑梗死的相关关系进行综述,以更好地了解外周血MMP-9水平变化与脑梗死的关系。     

癫痈大鼠血脑屏障通透性与脑基质金属蛋白酶-9表达的相关性研究

目的：研究癫痫大鼠血脑屏障（BBB）通透性改变与基质金属蛋白酶-9（MMP-9）表达的相关性。方法：用荧光显微镜及免疫组化方法观察不同处理因素下伊文思蓝（EB）海马区染色程度及MMP-9免疫反应阳性表达的变化。结果：正常情况下，大鼠海马区EB透过量和MMP-9免疫反应阳性表达较少。致痫后EB在海马区的透过量及MMP-9免疫反应阳性表达增多。地塞米松对海马区EB透过量和MMP-9免疫反应阳性表达有抑制作用。结论：癫痫大鼠脑内海马区MMP-9的表达与BBB通透性改变时相一致。地塞米松对这一过程有显著的抑制作用。     

基质金属蛋白酶与实验性自身免疫性脑脊髓炎的免疫屏障

实验性自身免疫性脑脊髓炎（experimental autoimmune cncephalomyelitis，EAE）是一种主要由T细胞介导的，以中枢神经系统（CNSl内小血管周围单个核细胞浸润及白质髓鞘脱失为特征的自身免疫性疾病。EAE炎性脱髓鞘的过程有许多重要的炎性细胞因子参与。基质金属蛋白酶（matrix metalloproteinase，MMPs）尤其是MMP-9、MMP-2是引起血脑屏障（blood brain barrier，BBB）的免疫屏障破坏，炎性细胞浸润以及介导细胞外基质（ECM）和髓磷脂降解的重要因素。[第一段]     

基质金属蛋白酶-9与脑梗死的关系

近年研究发现炎症在动脉粥样硬化及脑梗死中发挥重要作用，炎性标志物基质金属蛋白酶-9（MMP-9）可降解细胞外基质，削弱纤维帽的结构，增加动脉粥样硬化斑块的不稳定性，加速斑块裂解，促进斑块破裂和血栓形成。脑梗死时MMP-9过度表达可破坏血-脑脊液屏障并形成脑水肿，在继发性脑出血和脑损伤过程中发挥了关键性作用。     

基质金属蛋白酶-9与脑缺血

基质金属蛋白酶-9（matrix metalloproteinase-9．MMP-9）是一种依赖锌离子的蛋白酶，因其表达细胞众多，作用底物广泛而备受重视，与脑血管病发病过程关系密切．已成为研究热点之一。脑缺血后表达的MMP-9能降解基底膜而破坏血脑屏障（blood brain barrier，BBB），导致血管源性脑水肿和出血转化．新近的研究还发现了MMP-9在脑缺血后神经元凋亡中的作用。MMP-9抑制剂被认为是治疗缺血性脑血管病很有前景的药物，充分理解脑缺血后MMP-9的作用机制将对缺血性脑血管病冶疗有重要的启示。     

动脉粥样硬化性脑梗死患者血清C反应蛋白及血浆MMP-9的表达及意义

目的通过检测动脉粥样硬化性脑梗死患者血清C反应蛋白（hs-CRP）,血浆基质金属蛋白酶-9（MMP-9）的水平以及血清中血脂相关指标,以探讨它们在脑梗死中的表达及意义。方法选择35例动脉粥样硬化性脑梗死患者为病例组,选择同期年龄、性别相匹配的健康体检者20例为对照组,用免疫比浊法测定血清hs-CRP水平,用酶联免疫吸附法测定血浆MMP-9水平,同时运用多普勒超声测定颈动脉内膜中层厚度（IMT）,全自动生化仪测定血脂指标（TC,TG,LDL）,采用NIHSS评分量表对患者进行神经功能缺损评分。结果动脉粥样硬化性脑梗死患者hs-CRP、MMP-9、TC、TG、LDL、IMT值均较对照组增高（P〈0.05）。病例组hs-CRP、MMP-9水平均与NHISS评分相关,与TC、TG、LDL、IMT值无相关性。MMP-9与hs-CRP水平呈直线正相关。结论 MMP-9及hs-CRP可能参与了动脉粥样硬化性脑梗死的病理过程,可以提示病情的严重程度。     

基质金属蛋白酶9基因多态性与脑梗死的关系研究

目的：探讨基质金属蛋白酶9（MMP-9）启动子区C-1562T的基因多态性与脑梗死的关系。方法：用聚合酶链反应-限制性片段长度多态性（PCR-RFLP）技术检测224例脑梗死患者（脑梗死组）和112例同期健康体检者（对照组）的MMP-9启动子区的1562C/T的基因多态性,并进行基因测序,检测MMP-9C-1562T的基因型。结果：脑梗死组MMP-9基因的1562C/T的基因多态性出现频率（16.96%）与对照组（17.86%）无明显差异。结论：MMP-9基因C-1562T的基因多态性与脑梗死无相关性。     

基质金属蛋白酶-9在缺血性脑损伤和脑缺血耐受中的表达

基质金属蛋白酶-9(MMP-9)在脑缺血时可以通过降解基底膜及紧密连接破坏血脑屏障,从而导致脑缺血后继发性脑水肿和脑出血。脑梗死时MMP-9表达增强,病情加重;而脑缺血预处理可诱导MMP-9表达下调,提示MMP-9可能参与脑缺血耐受形成的过程。本文就MMP-9在缺血性脑损伤和脑缺血耐受中表达的研究进展进行综述。     

血清MMP-9与脑梗死患者及其颈动脉粥样硬化斑块稳定性的关系研究

目的检测具有不同性质颈动脉粥样硬化斑块的脑梗死患者的血清基质金属蛋白酶-9（MMP-9）水平,探讨颈动脉粥样硬化斑块稳定性及相关炎性标志物MMP-9水平与脑梗死的关系。方法采用彩色多普勒超声检查48例颈内动脉系统的急性脑梗死患者（CI组）颈动脉粥样硬化斑块,同时检测患者血清MMP-9水平,并与20例慢性脑供血不足患者（CCCI组）及20例体检健康者（对照组）比较;根据斑块性质将CI组分为不稳定斑块组、稳定斑块组及无斑块组3个亚组,并进行组内比较。结果脑梗死组斑块检出率、不稳定斑块率及血清MMP9水平均明显高于慢性脑供血不足组及对照组（P〈0．05）;脑梗死不稳定斑块组MMP-9水平显著高于脑梗死稳定斑块组,脑梗死稳定斑块组高于脑梗死无斑块组（P〈0．01）。结论颈动脉粥样硬化斑块及其稳定性与脑梗死发生有密切关系,具有不同性质颈动脉斑块的脑梗死患者的血清MMP-9水平存在差异,MMP-9可能是不稳定性粥样硬化斑块及脑梗死的一个潜在的血清标志物。     

普罗布考对脑梗死患者急性期血清MMP-9水平的影响

目的 观察普罗布考对脑梗死患者急性期血清基质金属蛋白酶9（matrix metalloproteinases9，MMP-9）水平的影响。方法 采用自身对照和组间对照，将62例急性期脑梗死患者分为2组，其中普罗布考组（32例），常规治疗组（30例），用酶谱法分别测定治疗前后血清MMP-9水平的变化。结果 （1）普罗布考组治疗2周后血清MMP-9水平较治疗前明显降低（P〈0．05），而常规治疗组治疗前后血清MMP-9水平无明显差异（P〉0．05）；（2）治疗2周后普罗布考组血清MMP-9水平较常规治疗组明显降低（P〈0．05）。结论 普罗布考能降低脑梗死患者急性期血清MMP-9水平，可能因此抑制了血-脑屏障的早期开放和脑水肿，从而减轻缺血性脑损伤，防止脑梗死出血转化和再发。     

实验性大鼠脑动脉瘤形成过程中MMP-2、MMP-9表达的动态变化

目的探讨实验性大鼠动脉瘤形成过程中基质金属蛋白酶2(MMP-2)、基质金属蛋白酶9(MMP-9)的表达规律。方法制作肾性高血压大鼠脑动脉瘤模型,通过免疫组化在蛋白水平系统动态观察肾性高血压大鼠脑动脉瘤形成过程中MMP-2、MMP-9表达的变化。结果实验组在术后1 w脑动脉壁即可见MMP-2、MMP-9表达增加,随着术后时间的推移和大鼠血压的增高,其表达也迅速增加,术后1个月基本达最高峰并一直持续至4个月,其中MMP-9较正常状态的增加比MMP-2的表达增加更为显著。对照组脑动脉壁MMP-2、MMP-9也有微弱表达,且MMP-2表达较MMP-9略强。结论脑动脉壁MMP-9、MMP-2特别是MMP-9的过度表达导致的脑动脉壁胶原纤维及内弹力层破坏是脑动脉瘤形成的主要原因之一。     

Increases in matrix metalloproteinase-9 and tissue inhibitor of matrix metalloproteinase-1 mRNA after cerebral contusion and depolarisation

Matrix metalloproteinases (MMPs) and tissue inhibitors of matrix metalloproteinases (TIMPs) play major roles in physiological extracellular matrix turnover during normal development and in pathological processes. In brain, increases in MMP activity occur, for example, in multiple sclerosis, Alzheimer's disease, and after head trauma. We examined MMP-9 and TIMP-1, -2, and -3 in events after head trauma. A time-course study was carried out using two different rat injury models, cerebral contusion and depolarisation. Brains were analysed by RT-PCR and in situ hybridisation. We observed a distinct and time-dependent upregulation of MMP-9 and TIMP-1 mRNA in ipsilateral cortical areas. MMP-9 mRNA levels were upregulated 1 day after cerebral contusion with a peak at Day 4. Depolarisation per se, which also occurs after traumatic brain injury, lead to delayed increase of MMP-9 mRNA, 4 days post application. At Day 14, MMP-9 mRNA levels were indistinguishable from controls in both models. TIMP-1 mRNA increases were observed in both models 4 hr after injury, and increased further at Days 1 and 4. At Day 14, mRNA levels declined and were no higher than control levels. No alterations in mRNA levels were noted for TIMP-2 or -3. Our results support earlier reports on MMP-9 involvement in brain injury. It also shows a role for TIMP-1 in the mechanisms of trauma, where depolarisation could be the mechanism responsible for this upregulation.     

Herpes-simplex virus encephalitis is characterized by an early MMP-9 increase and collagen type IV degradation

Cerebrovascular complications including cerebral edema, raised intracranial pressure and hemorrhage contribute to the high mortality and morbidity of herpes-simplex virus encephalitis (HSE). We examined changes of collagen type IV, the major constituent of the neurovascular matrix, together with expression and localization of matrix-degrading enzymes during the development of acute HSE. In an experimental model of focal HSE, we found that early, symptomatic HSE (3 days after infection) and acute, fully developed HSE (7 days after infection) are associated with significantly raised levels of matrix-metalloproteinase-9 (MMP-9) (both P<0.05). In situ zymography of brain sections revealed that the increase of MMP-9 was restricted to the cerebral vasculature in early HSE and further expanded towards the perivascular space and adjacent tissue in acute HSE. Around the cerebral vasculature, we observed that MMP-9 activity was insufficiently counterbalanced by its endogenous tissue inhibitor of MMP (TIMP) TIMP-1, resulting in loss of collagen type IV. Our findings suggest that MMP-9 is involved in the evolution of HSE by causing damage to the cerebral vasculature. The degradation of the neurovascular matrix in HSE facilitates the development of cerebrovascular complications and may represent a target for novel adjuvant treatment strategies.     

大鼠脑缺血再灌注后MMP-9的表达及人工合成E-选择素的干预作用

目的：研究肿瘤坏死因子-α（TNF-α）和基质金属蛋白酶-9（MMP-9）参与大鼠脑缺血再灌注损伤的机制及人工合成E-选择素保护作用的机制。方法：健康SD大鼠,随机分为手术组、假手术组和治疗组。手术组建立大鼠局灶性脑缺血再灌注损伤模型;治疗组术前从股静脉注射人工合成E-选择素;假手术组仅将线栓插到颈外动脉、颈内动脉分叉处,其余步骤同手术组。免疫组化检测脑组织中TNF-α和MMP-9的表达,RT-PCR检测MMP-9mRNA的表达。结果：手术组TNF-α、MMP-9和MMP-9mRNA表达与假手术组比较均有明显升高（P〈0．05）;治疗组TNF-α、MMP-9和MMP-9mRNA表达水平比手术组明显下降（P〈0．05）。相关分析表明,MMP-9mRNA分别与TNF-α和MMP-9的表达呈正相关。结论：大鼠脑缺血再灌注后TNF-α能够在转录水平诱导MMP-9的表达。人工合成E-选择素降低大鼠脑缺血再灌注后缺血脑组织MMP-9表达的机制可能是抑制TNF-α对MMP-9mRNA合成的诱导,从而降低了MMP-9的表达。     

Neurological and pathological improvements of cerebral infarction in mice with platinum nanoparticles

Ischemic stroke is a major, urgent neurologic disorder in which reactive oxygen species (ROS) are deeply involved in the detrimental effects. Platinum nanoparticle (nPt) species are a novel and strong scavenger of such ROS, so we examined the clinical and neuroprotective effects of nPts in mouse ischemic brain. Mice were subjected to transient middle cerebral artery occlusion (tMCAO) for 60 min. Upon reperfusion, nPt or vehicle was administered intravenously. At 48 hr after the tMCAO, motor function, infarct volume, immunohistochemistry of neurovascular components (endothelial NAGO, tight junctional occludin, and basal laminal collagen IV), and zymography for MMP-9 activity were examined. Superoxide anion generation at 2 hr after tMCAO was determined with oxidized hydroethidine. Compared with vehicle, treatment with nPts significantly improved the motor function and greatly reduced the infarct volume, especially in the cerebral cortex. Immunohistochemical analyses revealed that tMCAO resulted in a minimal decrease of NAGO and occludin but a great decrease of collagen IV and a remarkable increase of MMP-9. Treatment with nPts greatly reduced this decrease of collagen IV and activation of MMP-9 and, with large reductions of MMP-9 activation on zymography and superoxide production. The present study demonstrates that treatment with nPts ameliorates the neurological scores with a large reduction in infarct size as well as the preservation of outer components of the neurovascular unit (collagen IV) and inactivation of MMP-9. A strong reduction of superoxide anion production by nPts could account for such remarkable neurobehavioral and neuroprotective effects on ischemic stroke.     

Neutrophil infiltration increases matrix metalloproteinase-9 in the ischemic brain after occlusion/reperfusion of the middle cerebral artery in rats.

Matrix metalloproteinase-9 (MMP-9) activity increases in the brain during the first day after focal ischemia and might be involved in the pathogenesis of tissue damage. We previously showed MMP-9 in the extracellular space of brain parenchyma along with neutrophil recruitment after ischemia. In the present study, we tested whether neutrophils were a direct source of enhanced MMP-9 in the ischemic brain. Neutrophil infiltration was prevented either by injecting an antibody against ICAM-1, which abrogates neutrophil adhesion to the endothelial vessel wall, or by inducing neutropenia. One-hour intraluminal middle cerebral artery occlusion with reperfusion was induced, and studies were performed at 24 hours. Circulating neutrophils expressed 95-kDa MMP-9 and dimers, and infiltrated neutrophils stained positive for MMP-9. The expression of MMP-9 (mainly 95-kDa proform and dimers and, to a lesser extent, 88-kDa form) increased in brain after ischemia/reperfusion. Treatments preventing neutrophil infiltration failed to preclude the ischemia-induced increase in 88-kDa MMP-9 form and gelatinase activity in neurons and blood vessels. However, these treatments prevented the major increase in 95-kDa MMP-9 form and dimers. We conclude that neutrophil infiltration highly contributes to enhanced MMP-9 in the ischemic brain by releasing MMP-9 proform, which might participate in the tissular inflammatory reaction.     

脑缺血/再灌注损伤时MMP-9的表达及银杏叶提取物的干预作用

目的观察银杏叶制剂对大鼠脑缺血再灌注后基质金属蛋白酶（MMPs）表达的影响，探讨其对脑缺血再灌注损伤的保护作用及其机制。方法应用明胶酶谱法（SDS—PAGE enzymograph）测各组脑组织不同时间点MMP-9的表达。结果MMP-9的动态变化：模型组缺血／再灌注6h后，大鼠缺血部位脑内可见少量的MMP-9的表达，24h明显升高，48h达高峰，3d时有所下降，5d时水平更低。假手术组的脑内未见到MMP-9的表达，24h和48h组与模型组相比有显著性差异，而银杏叶治疗组的脑内MMP-9的表达24h也明显升高，但是小于模型组，48h的峰值较模型组低，3d、5d下降。银杏叶治疗组的脑内MMP-9的表达24h和48h组与模型组相比差异有显著性。结论缺血／再灌注可引起MMP-9表达异常，并且呈动态变化；银杏叶提取物对MMP-9表达有干预作用，能够降低MMP-9的合成上调程度；其可能的作用机制为减轻脑缺血后的炎症性病理损害，减轻脑水肿，改善局部脑血液循环。     

Mmp-9 deficiency enhances collagenase-induced intracerebral hemorrhage and brain injury in mutant mice.

Matrix metalloproteinase-9 (MMP-9) participates in the disregulation of blood-brain barrier during hemorrhagic transformation, and exacerbates brain injury after cerebral ischemia. However, the consequences of long-term inhibition or deficiency of MMP-9 activity (which might affect normal collagen or matrix homeostasis) remains to be determined. The authors investigated how MMP-9 gene deficiency enhances hemorrhage and increases mortality and neurologic deficits in a collagenase-induced intracerebral hemorrhage (ICH) model in MMP-9-knockout mice. MMP-9-knockout and corresponding wild-type mice at 20 to 35 weeks were used to model an aged population (because advanced age is a significant risk factor in human ICH). Collagenase VII-S (0.5 microL, 0.075 U) was injected into the right basal ganglia in mice and mortality, neurologic deficits, brain edema, and hemorrhage size measured. In addition, MMP-9 activity, brain collagen content, blood coagulation, cerebral arterial structure, and expressions of several MMPs were examined. Increased hemorrhage and brain edema that correlated with higher mortality and neurologic deficits were found in MMP-9-knockout mice. No apparent structural changes were observed in cerebral arteries, even though brain collagen content was reduced in MMP-9-knockout mice. MMP-9-knockout mice did exhibit an enhanced expression of MMP-2 and MMP-3 in response to ICH. The results indicate that a deficiency of MMP-9 gene in mutant mice increases collagenase-induced hemorrhage and the resulting brain injury. The intriguing relationship between MMP-9 deficiency and collagenase-induced ICH may reflect the reduction in collagen content and an enhanced expression of MMP-2 and MMP-3.     

伴高血压病的脑梗死患者血清基质金属蛋白酶-9水平变化及意义

目的探讨伴高血压急性脑梗死患者血清基质金属蛋白酶-9（MMP-9）水平变化及意义。方法选择临床上发病3天内入院的伴有原发性高血压病的急性前循环脑梗死患者65例,不伴原发性高血压病的急性前循环脑梗死的患者43例,原发性高血压病患者30例,健康对照组30例,采集空腹静脉血。用ELISA法检测其血清MMP-9水平。结果伴有原发性高血压病急性脑梗死组患者血清MMP-9水平（316.18±52.26ng/ml）明显高于其他三组（均P〈0.01）,不伴原发性高血压病的脑梗死组患者血清MMP-9水平（287.65±48.83ng/ml）明显高于原发性高血压病组（206.82±44.22ng/ml）和健康对照组（112.16±36.28ng/ml）（均P〈0.01）。原发性高血压组患者血清MMP-9水平明显高于对照组（P〈0.01）。结论高血压病患者及脑梗死患者血清MMP-9均有明显增高,血清MMP-9的活性增强可能是高血压导致脑梗死发生的机制之一,血清MMP-9可能在高血压脑梗死患者的发病及继发的病理损害中发挥更为重要的作用。血清MMP-9可以作为高血压病患者脑梗死前的预警指标。