IMM-H004 prevents toxicity induced by delayed treatment of tPA in a rat model of focal cerebral ischemia involving PKA-and PI3K-dependent Akt activation
IMM-H004 prevents toxicity induced by delayed treatment of tPA in a rat model of focal cerebral ischemia involving PKA-and PI3K-dependent Akt activation
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DOI：
10.1111/ejn.12551
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发表时间：
2014-06-01
影响因子：
3.4
通讯作者：
Chen, Naihong
中科院分区：
文献类型：
--
作者：
Zuo, Wei;Chen, Jiao;Chen, Naihong
目前治疗缺血性卒中的方法是溶栓治疗，如果超过其相对较窄的治疗时间窗，则会导致出血性转化(HT)。本研究旨在探讨香豆素衍生物IMM-H004在重组组织型纤溶酶原激活剂(TPA)诱导的高血压中的作用。血栓栓塞组或大脑中动脉闭塞6h组大鼠接受或不加IMM-H004的tPA干预。延迟的tPA干预显著增加了高血压的危险性，加重了缺血损伤。采用行为学、TTC染色、脑出血测定、激光散斑成像、Western印迹、明胶酶谱、免疫组织化学和免疫荧光染色等方法，评价IMM-H004对大鼠脑缺血再灌注后tPA毒性的延缓治疗作用。我们还在人脑微血管内皮细胞(HBMECs)和PC12细胞上进行了体外实验，以探讨IMM-H004的作用机制。TPA和IMM-H004联合治疗可阻止HT的发展，降低死亡率、脑梗塞体积和脑水肿。IMM-H004还通过减少基质金属蛋白酶、基质金属蛋白酶-2与星形胶质细胞的共存和增加封闭素而发挥保护作用。在HBMECs和PC12中的实验表明，在给予tPA后，IMM-H004提高了ATP水平，并激活了蛋白激酶A和PI3K依赖的Akt。这些结果提示IMM-H004是一种有希望的佐剂，可以减轻tPA在缺血性卒中临床治疗中的不良反应，并有助于更好地理解这一新药物有益作用的机制。
Ischemic stroke is currently treated with thrombolytic therapy with a drawback to induce hemorrhagic transformation (HT) 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. Rats subjected to 6h of thromboembolic occlusion or middle cerebral artery occlusion received tPA with or without IMM-H004. Delayed tPA intervention drastically increased the risk of HT and exaggerated 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 a 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 (HBMECs) and PC12 cells to explore the mechanism for the role of IMM-H004. Combination therapy of tPA and IMM-H004 prevented the development of HT, and reduced the mortality rate, infarct volume and brain edema. IMM-H004 also exerted a protective role by decreasing matrix metalloproteinases, the co-localization of matrix metalloproteinase-2 with astrocytes and increasing occludin. Experiments in HBMECs and PC12 revealed an elevation in ATP level and a protein kinase A- and PI3K-dependent activation of Akt by IMM-H004 after tPA administration. These results suggest IMM-H004 as a promising adjuvant to alleviate the detrimental side effects of tPA in clinical therapy of ischemic stroke, and contribute to better understand the mechanism for the beneficial role of this novel remedy.