Background: Cerebral hemorrhagic stroke, including intracerebral hemorrhage (ICH), subarachnoid hemorrhage (SAH), and hemorrhagic transformation after cerebral infarction, is a major medical emergency in the neurology, neurosurgery, emergency and other clinical departments. The pathophysiological mechanisms of these cerebral hemorrhagic diseases have not been fully elucidated, and there are no effective pharmacological and molecular treatments against these diseases. Matrix metalloproteinase-9 (MMP-9), also known as collagenase B, is one of the most important members of the matrix metalloproteinases (MMPs) family.Objective: This article reviews the role of MMP-9 in the pathogenesis of diseases such as brain hemorrhage, hemorrhagic transformation after cerebral infarction, SAH, and brain injury. Results: The expression levels of MMP-9 in brain tissue increased after cerebral hemorrhage and related to the prognosis of brain hemorrhage. MMP-9 is related to post-thrombolytic hemorrhagic transformation after cerebral infarction. Inhibition of MMP-9 can reduce secondary brain injury after brain hemorrhage. MMP-9 aggravates the early brain injury and cerebral vasospasm after SAH. Conclusion: MMP-9 is involved in the pathological process of hemorrhagic stroke through a variety of mechanisms and is closely related to prognosis after cerebral hemorrhagic stroke.
Keywords: Matrix metalloproteinase-9, intracerebral hemorrhage, subarachnoid hemorrhage, hemorrhagic transformation, brain injury.