论文部分内容阅读
OBJECTIVE Ischemic stroke is currently treated with thrombolytic therapy with a drawback to induce hemorrhagic transformation if applied beyond its relatively narrow treatment time window.The present study was designed to examine the role of IMM-H004, a derivative of coumarin, in recombinant tissue plasminogen activator (tPA)-induced HT.METHODS Rats subjected to 6 h thromboembolic occlusion or middle cerebral artery occlusion received tPA with or without IMM-H004.Delayed tPA intervention drastically increased the risk of HT and exaggerating the ischemic injury.To assess the effect of IMM-H004 on delayed treatment of tPA-induced toxicity after ischemia and reperfusion, various approaches were used including behavior test, TTC-staining, determination of cerebral hemorrhage, laser speckle imaging, western blot, gelatin zymogram, immunohistochemistry and immunofluorescence staining.Experiments were also conducted in vitro in human brain microvascular endothelial cells and PC12 cells to explore the mechanism for the role of IMM-H004.RESULTS Combination therapy of tPA and IMM-H004 prevented the development of HT, reduced the mortality rate, infarct volume and brain edema.IMM-H004 also exerted protective role by decreasing matrix metalloproteinases, the colocalization of matrix metalloproteinase-2 with astrocytes and increasing occludin.Experiments in HBMEC and PC12 revealed an elevation in ATP level and a PKA-and PI3K-dependent activation of Akt by IMM-H004 after tPA administration.CONCLUSION These results suggest IMM-H004 as a promising adjuvant to alleviate the detrimental side effect of tPA in therapy of ischemic stroke in clinic, and contribute to better understanding the mechanism for the beneficial role of this novel remedy.