title: Identification of two phosphorylation sites essential for annexin A1 in blood-brain barrier protection after experimental intracerebral hemorrhage in rats.
abstract: Annexin A1 has been reported to exert a blood-brain barrier protection. This study was designed to examine the role of annexin A1 in intracerebral hemorrhage-induced blood-brain barrier dysfunction. A collagenase intracerebral hemorrhage model was performed in adult male Sprague Dawley rats. First, a possible relationship between annexin A1 and intracerebral hemorrhage pathology was confirmed by a loss of annexin A1 in the cerebrovascular endothelium and serum of intracerebral hemorrhage rats, and the rescue effects of i.v. administration of human recombinant annexin A1 in vivo and annexin A1 overexpression in vitro on the barrier function of brain microvascular endothelial cells exposed to intracerebral hemorrhage stimulus. Second, we found that intracerebral hemorrhage significantly increased the phosphorylation ratio of annexin A1 at the serine/threonine residues. Finally, based on site-specific mutagenesis, we identified two phosphorylation sites (a) annexin A1 phosphorylation at threonine 24 is required for its interaction with actin cytoskeleton, and (b) phosphorylation at serine27 is essential for annexin A1 secretion, both of which were essential for maintaining cytoskeleton integrity and paracellular permeability. In conclusion, annexin A1 prevents intracerebral hemorrhage-induced blood-brain barrier dysfunction in threonine 24 and serine27 phosphorylation-dependent manners. Annexin A1 phosphorylation may be a self-help strategy in brain microvascular endothelial cells after intracerebral hemorrhage; however, that was almost completely abolished by the intracerebral hemorrhage-induced loss of annexin A1.
authors.affiliation: 1 Department of Neurosurgery, The First Affiliated Hospital of Soochow University, Suzhou, China.
authors.forename: Zhong
authors.initials: Z
authors.lastname: Wang
authors.affiliation: 1 Department of Neurosurgery, The First Affiliated Hospital of Soochow University, Suzhou, China.
authors.forename: Zhouqing
authors.initials: Z
authors.lastname: Chen
authors.affiliation: 2 Department of Cardiovascular Surgery, The First Affiliated Hospital of Soochow University, Suzhou, China.
authors.forename: Junjie
authors.initials: J
authors.lastname: Yang
authors.affiliation: 2 Department of Cardiovascular Surgery, The First Affiliated Hospital of Soochow University, Suzhou, China.
authors.forename: Ziying
authors.initials: Z
authors.lastname: Yang
authors.affiliation: 1 Department of Neurosurgery, The First Affiliated Hospital of Soochow University, Suzhou, China.
authors.forename: Jia
authors.initials: J
authors.lastname: Yin
authors.affiliation: 1 Department of Neurosurgery, The First Affiliated Hospital of Soochow University, Suzhou, China.
authors.forename: Gang
authors.initials: G
authors.lastname: Zuo
authors.affiliation: 1 Department of Neurosurgery, The First Affiliated Hospital of Soochow University, Suzhou, China.
authors.forename: Xiaochun
authors.initials: X
authors.lastname: Duan
authors.affiliation: 1 Department of Neurosurgery, The First Affiliated Hospital of Soochow University, Suzhou, China.
authors.forename: Haitao
authors.initials: H
authors.lastname: Shen
authors.affiliation: 1 Department of Neurosurgery, The First Affiliated Hospital of Soochow University, Suzhou, China.
authors.forename: Haiying
authors.initials: H
authors.lastname: Li
authors.affiliation: 1 Department of Neurosurgery, The First Affiliated Hospital of Soochow University, Suzhou, China.
authors.forename: Gang
authors.initials: G
authors.lastname: Chen
mesh_terms: D000818:Animals; D017305:Annexin A1 / Q000097:blood / Q000235:genetics / Q000378:metabolism* / Q000494:pharmacology; D001812:Blood-Brain Barrier / Q000187:drug effects / Q000378:metabolism* / Q000503:physiopathology; D002460:Cell Line; D002543:Cerebral Hemorrhage / Q000378:metabolism* / Q000503:physiopathology; D004195:Disease Models, Animal; D042783:Endothelial Cells / Q000378:metabolism; D004730:Endothelium, Vascular / Q000187:drug effects / Q000378:metabolism*; D006801:Humans; D008297:Male; D055806:Microvessels / Q000187:drug effects / Q000378:metabolism; D016297:Mutagenesis, Site-Directed; D010766:Phosphorylation; D017207:Rats, Sprague-Dawley; D011994:Recombinant Proteins
chemical_list: D017305:Annexin A1; D011994:Recombinant Proteins
keywords: Intracerebral hemorrhage; annexin A1; blood–brain barrier; phosphorylation; secondary brain injury