title: Mechanisms of lumbrokinase in protection of cerebral ischemia.
abstract: The present study was designed to explore the mechanisms involved in the anti-ischemic action of lumbrokinase (LK) in brain. The enzyme immunoassay, spectrofluorimeter and flow cytometry were used to detect the level of adenosine 3',5'-cyclic monophosphate (cAMP) and guanosine 3',5'-cyclic monophosphate (cGMP), the Ca(2+) mobilization, and human platelet surface antigen expression in order to elucidate the anti-platelet action involved in LK cerebroprotection. RT-PCR and western blot were used to identify the role of Intercellular adhesion molecule-1 (ICAM-1) and Janus Kinase1/Signal Transducers and Activators of Transcription1 (JAK1/STAT1) pathway in protecting brain against ischemic injury by anti-thrombosis and anti-apoptosis. Results showed that LK significantly potentiated the activity of adenylate cyclase (AC), increased the cAMP level in vivo, remarkably inhibited the rise of rat platelet intracellular Ca(2+) ([Ca(2+)](i)), and attenuated the expression of Glycoprotein IIB/IIIA (GPIIB/IIIA) and P-selectin in human platelet stimulated by thrombin in vitro. Furthermore, the expressions of ICAM-1 and JAK1/STAT1 were remarkably regulated by LK in Human Umbilical Vein Endothelial Cell (HUVEC) and ischemic cerebral tissues. These data indicated that the anti-ischemic activity of LK was due to its anti-platelet activity by elevating cAMP level and attenuating the calcium release from calcium stores, the anti-thrombosis action due to inhibiting of ICAM-1 expression, and the anti-apoptotic effect due to the activation of JAK1/STAT1 pathway.
authors.affiliation: Institute of Clinical Pharmacology of Second Hospital, Harbin Medical University, Harbin, PR China.
authors.forename: Hongrui
authors.initials: H
authors.lastname: Ji
authors.forename: Lian
authors.initials: L
authors.lastname: Wang
authors.forename: Hui
authors.initials: H
authors.lastname: Bi
authors.forename: Lihua
authors.initials: L
authors.lastname: Sun
authors.forename: Benzhi
authors.initials: B
authors.lastname: Cai
authors.forename: Yuping
authors.initials: Y
authors.lastname: Wang
authors.forename: Jinlong
authors.initials: J
authors.lastname: Zhao
authors.forename: Zhimin
authors.initials: Z
authors.lastname: Du
mesh_terms: D000818:Animals; D001792:Blood Platelets / Q000187:drug effects; D002545:Brain Ischemia / Q000378:metabolism / Q000517:prevention & control*; D002478:Cells, Cultured; D000242:Cyclic AMP / Q000097:blood; D006152:Cyclic GMP / Q000097:blood; D010450:Endopeptidases / Q000494:pharmacology* / Q000627:therapeutic use; D042783:Endothelial Cells / Q000187:drug effects / Q000378:metabolism; D039661:Integrin beta3 / Q000097:blood; D018799:Intercellular Adhesion Molecule-1 / Q000235:genetics; D008297:Male; D018696:Neuroprotective Agents / Q000494:pharmacology*; D040201:Platelet Membrane Glycoprotein IIb / Q000097:blood; D051381:Rats; D017208:Rats, Wistar; D013917:Thrombin / Q000494:pharmacology
chemical_list: D039661:Integrin beta3; D018696:Neuroprotective Agents; D040201:Platelet Membrane Glycoprotein IIb; D018799:Intercellular Adhesion Molecule-1; D000242:Cyclic AMP; D010450:Endopeptidases; D013917:Thrombin; C083421:lumbrokinase; D006152:Cyclic GMP