| Background and purpose:Intracerebral hemorrhage (ICH) is a critical subtype of cerebrovascular disease, with higher morbility in China than western countries. In spite of the medical strategy for the acute phase of ICH is becaming more and more standardized, it still be limited to evacuation of the hematoma and supporting therapy. At present, there is no effective therapeutic method for patients to improve neurological deficits caused by ICH. So the fatality rate and disability rate still remain high in the last ten years. The foregone injured mechanism of ICH demonstrated that the composition, structures and distribution of extracellular matrix (ECM) all have changed. Destruction of blood brain barrier (BBB), formation of brain edema, and etc are closely relevant to ECM. The former research confirmed that ECM participate in formation, development, restoration and regeneration of embryo and all kinds of tissues and organs. Moity of ECM were relevated to physiological and pathological process of nervous system. In addition, matrix metalloproteinases (MMPs), integrins, selectins, hyaluronidase and the other proteins associated with function of ECM, participating in inflammatory reaction, neoplasm metastasis, vasculogenesis, wound healing and the other process. Accordingly, the purpose of the present study is to clarify the mechanism of neurological function recovery following ICH by investigating genes associated ECM, and to provide new clues and ideas for exploring the clinical and basic treatment of ICH.Methods:This study was divided into two parts.(1) Models of ICH were administered by injecting type Ⅶ collagenase into brain of the rats. Sham controls received the same volume of0.9%sterile saline. Gene chip technology was used to detect genes correlated with ECM following ICH.(2) According to the results in the first part, collagen Ⅰ, collagen Ⅲ, collagenⅣ, MMP-2, MMP-9, MT1-MMP, integrin αvβ3and integrin α5β1were selected for further validation. The rats were divided into sham-operated group and model group, and given the same treatment with the rats in the first part. Confocal laser scanning microscopy was used to observed angioarchitecture and blood perfusion of damage zone after fluorescein isothiocyanate (FITC)-dextran injection. Immunohistochemisty were used to identify proliferating cell nuclear antigen (PCNA)+/von Willebrand factor+(vWF) nuclei, and the spatial and temporal distribution of collagen Ⅰ, collagen Ⅲ, collagen Ⅳ, MMP-2, MMP-9, MT1-MMP, integrin αvβ3and integrin α5β1. The expression level of protein collagen Ⅰ, collagenⅢ, collagenⅣ, MMP-2, MMP-9, MT1-MMP, integrin β3and integrin α5were evaluated by Western blot.Results:Results of gene chip detection showed that ECM-related genes such as cluster of differentiation (CD)44, oesteopontin (OPN/SPP-1), cadherin-1, elastin microfibril interfacer (EMILIN)-1, intercellular adhesion molecule (ICAM)-1, transforming growth factor (TGF)-β as well as most members of collagens, MMPs, intergrins all have different tendency at different time points after ICH induction, and it suggests that ECM may be revelant to repairing of neural injury following ICH. The result after FITC-dextran perfusion showed that the blood perfusion around the hematoma at4days after ICH decrease obviously than that of sham operation, The density of microvessel around the injured brain tissue continuously increasd from7days to14days after ICH and reach peak value at21days. Immunohistochemisty displayed that PCNA+nuclei in vWF+dilated vessels could be observed around the hematoma at4days, and peaked at14days after ICH induction. Numerous collagen Ⅰ, collagen Ⅲ, collagen Ⅳ, MMP-2, MMP-9, MT1-MMP, integrin αvβ3and integrin α5β1positive blood vessel could be detected around the hematoma. Results of Western blot suggested that the expression of protein collagen Ⅰ, collagen Ⅲ, collagen Ⅳ, MMP-2, MMP-9, MT1-MMP, integrin β3and integrin a5all increased obviously at4days after ICH than that in the sham operation group. Expression of collagen Ⅰ and collagen Ⅲ arrived climax at14days and lasted to21days, while expression of collagen Ⅳ started to reduce from14days. Protein level of MMP-9decreased from at7days, while the expression of MMP-2, MT1-MMP, integrin β3and integrin α5gradually increased untill14days and decreased at21days.Conclusions:1. Expression of genes correlated with ECM changed after ICH, the alteration may be relevant to inflammatory reaction and tissue repair process in the brain.2. Collagens, MMPs and integrins contiued to increase following ICH, and they may modify interaction between cerebral microvessel and peripheral ECM, thus to affect angiogenesis and restore injured brain tissue. |
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