title: The glucagon-like peptide-1 receptor agonist exendin-4 ameliorates warfarin-associated hemorrhagic transformation after cerebral ischemia.
abstract: As the number of patients with cardioembolic ischemic stroke is predicted to be double by 2030, increased burden of warfarin-associated hemorrhagic transformation (HT) after cerebral ischemia is an expected consequence. However, thus far, no effective treatment strategy is available for HT prevention in routine clinical practice. While the glucagon-like peptide-1 receptor (GLP-1R) agonist exendin-4 (Ex-4) is known to protect against oxidative stress and neuronal cell death caused by ischemic brain damage, its effect on preventing warfarin-associated HT after cerebral ischemia is yet unknown. Therefore, we hypothesized that Ex-4 would stabilize the blood-brain barrier (BBB) and suppress neuroinflammation through PI3K-Akt-induced inhibition of glycogen synthase kinase-3β (GSK-3β) after warfarin-associated HT post-cerebral ischemia.
  
  
  
  We used male C57BL/6 mice for all experiments. A 5-mg warfarin sodium tablet was dissolved in animals' drinking water (effective warfarin uptake 0.04 mg (2 mg/kg) per mouse). The mice were fed for 0, 6, 12, and 24 h with ad libitum access to the treated water. To study the effects of Ex-4, temporary middle cerebral artery occlusion (MCAO) was performed. Then, either Ex-4 (10 mg/kg) or saline was injected through the tail vein, and in the Ex-4 + wortmannin group, PI3K inhibitor wortmannin was intravenously injected, after reperfusion. The infarct volume, neurological deficits, and integrity of the BBB were assessed 72 h post MCAO. One- or two-way ANOVA was used to test the difference between means followed by Newman-Keuls post hoc testing for pair-wise comparison.
  
  
  
  We observed that Ex-4 ameliorated warfarin-associated HT and preserved the integrity of the BBB after cerebral ischemia through the PI3K/Akt/GSK-3β pathway. Furthermore, Ex-4 suppressed oxidative DNA damage and lipid peroxidation, attenuated pro-inflammatory cytokine expression levels, and suppressed microglial activation and neutrophil infiltration in warfarin-associated HT post-cerebral ischemia. However, these effects were totally abolished in the mice treated with Ex-4 + the PI3K inhibitor-wortmannin. The PI3K/Akt-GSK-3β signaling pathway appeared to contribute to the protection afforded by Ex-4 in the warfarin-associated HT model.
  
  
  
  GLP-1 administration could reduce warfarin-associated HT in mice. This beneficial effect of GLP-1 is associated with attenuating neuroinflammation and BBB disruption by inactivating GSK-3β through the PI3K/Akt pathway.
authors: Department of Neurology, Huashan Hospital, State Key Laboratory of Medical Neurobiology, Fudan University, No. 12 Middle Wulumuqi Road, Shanghai, 200040, China.
authors: Fangzhe
authors: F
authors: Chen
authors: The Department of Clinical Laboratory, Central Laboratory, Jing'an District Centre Hospital of Shanghai, Huashan Hospital Fudan University Jing'an Branch, No. 259 Xi Kang Road, Shanghai, 200040, China.
authors: Weifeng
authors: W
authors: Wang
authors: Department of Neurology, Huashan Hospital, State Key Laboratory of Medical Neurobiology, Fudan University, No. 12 Middle Wulumuqi Road, Shanghai, 200040, China.
authors: Hongyan
authors: H
authors: Ding
authors: Department of Neurology, Huashan Hospital, State Key Laboratory of Medical Neurobiology, Fudan University, No. 12 Middle Wulumuqi Road, Shanghai, 200040, China.
authors: Qi
authors: Q
authors: Yang
authors: Department of Neurology, Huashan Hospital, State Key Laboratory of Medical Neurobiology, Fudan University, No. 12 Middle Wulumuqi Road, Shanghai, 200040, China. dong_qiang@fudan.edu.cn.
authors: Qiang
authors: Q
authors: Dong
authors: Department of Neurology, Huashan Hospital, State Key Laboratory of Medical Neurobiology, Fudan University, No. 12 Middle Wulumuqi Road, Shanghai, 200040, China. cuimei@fudan.edu.cn.
authors: Mei
authors: M
authors: Cui
mesh_terms: D000818:Animals; D000925:Anticoagulants / Q000009:adverse effects*; D001812:Blood-Brain Barrier / Q000187:drug effects / Q000503:physiopathology; D001921:Brain / Q000000981:diagnostic imaging / Q000187:drug effects / Q000378:metabolism; D020520:Brain Infarction / Q000188:drug therapy / Q000209:etiology; D002545:Brain Ischemia / Q000150:complications / Q000188:drug therapy / Q000473:pathology; D016207:Cytokines / Q000378:metabolism; D004195:Disease Models, Animal; D000077270:Exenatide; D005786:Gene Expression Regulation / Q000187:drug effects; D006470:Hemorrhage / Q000139:chemically induced* / Q000188:drug therapy*; D007004:Hypoglycemic Agents / Q000494:pharmacology / Q000627:therapeutic use*; D020244:Infarction, Middle Cerebral Artery / Q000188:drug therapy; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D017628:Microglia / Q000378:metabolism / Q000473:pathology; D009422:Nervous System Diseases / Q000188:drug therapy / Q000209:etiology; D010455:Peptides / Q000378:metabolism / Q000494:pharmacology / Q000627:therapeutic use*; D015398:Signal Transduction / Q000187:drug effects; D014688:Venoms / Q000378:metabolism / Q000494:pharmacology / Q000627:therapeutic use*; D014859:Warfarin / Q000009:adverse effects*; D000097789:Glucagon-Like Peptide-1 Receptor Agonists
chemical_list: D000925:Anticoagulants; D016207:Cytokines; D007004:Hypoglycemic Agents; D010455:Peptides; D014688:Venoms; D014859:Warfarin; D000077270:Exenatide; D000097789:Glucagon-Like Peptide-1 Receptor Agonists
keywords: Blood-brain barrier; Cerebral ischemia; Exendin-4; Hemorrhagic transformation; Neuroinflammation; PI3K/Akt-GSK-3β signaling pathway; Warfarin