imm-h004 and Infarction--Middle-Cerebral-Artery

IMM-H004 (7-hydroxy-5-methoxy-4-methyl-3-[4-methylpiperazin-1-yl]-2H-chromen-2-one) is a novel coumarin derivative that showed better effect in improving global cerebral ischemia in rats. However, the effects and mechanisms in focal cerebral ischemia were not clear. Blood-brain barrier (BBB) protection is a vital strategy for the treatment of cerebral ischemia. This study is to investigate whether IMM-H004 improves brain ischemia injury via BBB protection.. Focal brain ischemia model was induced by middle cerebral artery occlusion for 1 hour and reperfusion (MCAO/R) for 24 hours in rats. IMM-H004 (1.5, 3, 6 mg/kg) and edaravone (positive drug, 6 mg/kg) were administered after 5 minutes of occlusion. Neurological score and TTC staining were used to evaluate the effect of IMM-H004. Evans Blue (EB) staining and electron microscopy were used to assess BBB permeability. Western blot, reverse transcription-polymerase chain reaction, and immunohistochemistry were used to detect the expression of BBB structure-related proteins.. Compared with the model group, IMM-H004 in the focal brain ischemia model improved neurological function and reduced cerebral infarction size and edema content. IMM-H004 sharply reduced the EB content and alleviated BBB structure. In addition, IMM-H004 increased the level of zonula occludens (ZO-1) and occluding, decreased the level of aquaporin 4 and matrix metalloproteinase 9, either in cortex or in hippocampus. And all of these changed were related to BBB protection.. IMM-H004 improved cerebral ischemia injury via BBB protection. For a potential therapy drug of cerebral ischemia, IMM-H004 merits further study.

Topics: Animals; Aquaporin 4; Blood-Brain Barrier; Brain Edema; Capillary Permeability; Cerebral Cortex; Coumarins; Cytoprotection; Disease Models, Animal; Dose-Response Relationship, Drug; Hippocampus; Infarction, Middle Cerebral Artery; Male; Matrix Metalloproteinase 9; Neuroprotective Agents; Occludin; Rats, Sprague-Dawley; Reperfusion Injury; Time Factors; Zonula Occludens-1 Protein

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 6 h 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.

Topics: Animals; Brain; Brain Ischemia; Cells, Cultured; Cerebral Hemorrhage; Coumarins; Cyclic AMP-Dependent Protein Kinases; Disease Models, Animal; Endothelial Cells; Fibrinolytic Agents; Humans; Infarction, Middle Cerebral Artery; Male; Neuroprotective Agents; PC12 Cells; Proto-Oncogene Proteins c-akt; Random Allocation; Rats; Rats, Sprague-Dawley; Recombinant Proteins; Thromboembolism; Time Factors; Tissue Plasminogen Activator