From the Division of Hematology/Oncology, Department of Internal Medicine (N.D., M.R.C., M.J., A.B., M.N., P.D., A.K.C.), University of Iowa, Iowa City.
Department of Radiology (D.T.), University of Iowa, Iowa City.
Stroke. 2019 May;50(5):1201-1209. doi: 10.1161/STROKEAHA.118.023697.
Background and Purpose- Cellular Fn-EDA (fibronectin containing extra domain A) is expressed in activated endothelial cells and elevated in circulation in patients with cardiovascular diseases. Although global deficiency of Fn-EDA in mice improves stroke outcome, the specific contribution of plasma versus endothelium Fn-EDA in stroke outcome is currently unknown. We investigated the role of plasma versus endothelial Fn-EDA in stroke exacerbation in the comorbid condition of hyperlipidemia. Methods- We generated novel plasma Fn-EDA ( Fn-EDA Alb ) and endothelial Fn-EDA ( Fn-EDA Tie2 ) strains on hyperlipidemic apolipoprotein E-deficient ( ApoE) background. By following the Stroke Therapy Academic Industry Roundtable guidelines, we evaluated stroke outcome in male and female mice. Susceptibility to ischemia/reperfusion injury was evaluated in 2 different models of stroke: intraluminal monofilament and embolic model on days 1, 3, and 7. Quantitative assessment of stroke outcome was evaluated by measuring infarct volume (by magnetic resonance imaging), cerebral blood flow (by laser speckle imaging), neurological and sensory-motor outcome, and postischemic thrombo-inflammation (platelet thrombi, fibrin, neutrophil, phospho-NFκB [nuclear factor κB], TNFα [tumor necrosis factor α], and IL1β [interleukin 1β]). Results- Stroke outcome was comparable in ApoE Fn-EDA Tie2 and control ApoE Fn-EDA mice suggesting endothelial Fn-EDA does not contribute to stroke. ApoE Fn-EDA Alb mice exhibited significantly smaller infarcts and improved neurological and sensory-motor outcome at days 1, 3, and 7 in monofilament and embolic models of stroke. Improved stroke outcome was concomitant with enhanced survival, and decreased postischemic thrombo-inflammatory response ( P<0.05 versus ApoE Fn-EDA ). No sex-based differences were observed. Laser speckle imaging revealed significantly improved regional cerebral blood flow at 1 hour in ApoE Fn-EDA Alb mice suggesting plasma Fn-EDA promotes postischemic secondary thrombosis. Coinfusion of anti-Fn-EDA antibody with r-tPA (recombinant tissue-type plasminogen activator) in ApoE mice, 1 hour after embolization, improved stroke outcome with enhanced survival, and improved neurological outcome ( P<0.05 versus r-tPA). Conclusions- Genetic evidence suggests that plasma Fn-EDA exacerbates stroke outcome by promoting postischemic thrombo-inflammation. Interventions targeting plasma Fn-EDA may reduce brain damage after reperfusion.
背景与目的-细胞型 Fn-EDA（含有额外结构域 A 的纤连蛋白）在激活的内皮细胞中表达，并在心血管疾病患者的循环中升高。尽管在伴有高脂血症的情况下，小鼠中 Fn-EDA 的全局缺失可改善中风预后，但血浆与内皮细胞 Fn-EDA 在中风预后中的具体贡献目前尚不清楚。我们研究了在高脂血症合并症中，血浆与内皮 Fn-EDA 在中风恶化中的作用。方法-我们在高脂血症的载脂蛋白 E 缺陷（ApoE）背景下生成了新型的血浆 Fn-EDA（Fn-EDA Alb）和内皮 Fn-EDA（Fn-EDA Tie2）株。按照中风治疗学术产业圆桌会议指南，我们评估了雄性和雌性小鼠的中风预后。通过两种不同的中风模型（腔内单丝和栓塞模型）在第 1、3 和 7 天评估对缺血再灌注损伤的易感性。通过磁共振成像（MRI）测量梗死体积、激光散斑成像（laser speckle imaging）测量脑血流、神经学和感觉运动学结局以及缺血后血栓炎症（血小板血栓、纤维蛋白、中性粒细胞、磷酸化 NFκB[核因子 κB]、TNFα[肿瘤坏死因子 α]和 IL1β[白细胞介素 1β]）来评估中风预后的定量评估。结果-在 ApoE Fn-EDA Tie2 和对照 ApoE Fn-EDA 小鼠中，中风预后相当，这表明内皮 Fn-EDA 不会导致中风。在腔内单丝和栓塞模型中，ApoE Fn-EDA Alb 小鼠在第 1、3 和 7 天的梗死体积更小，神经学和感觉运动学结局更好。改善的中风预后与生存率的提高以及缺血后血栓炎症反应的减少（与 ApoE Fn-EDA 相比，P<0.05）相关。未观察到性别差异。激光散斑成像显示在 ApoE Fn-EDA Alb 小鼠中，在栓塞后 1 小时时，区域脑血流明显改善，提示血浆 Fn-EDA 促进缺血后继发性血栓形成。在栓塞后 1 小时，将抗 Fn-EDA 抗体与 r-tPA（重组组织型纤溶酶原激活剂）共输注到 ApoE 小鼠中，可改善中风预后，提高生存率和神经学结局（与 r-tPA 相比，P<0.05）。结论-遗传证据表明，血浆 Fn-EDA 通过促进缺血后血栓炎症而加重中风预后。针对血浆 Fn-EDA 的干预措施可能会减少再灌注后的脑损伤。
