Cerebrovascular Pathology Research Group, Department of Neurology, Girona Biomedical Research Institute (IDIBGI), Parc Hospitalari Martí i Julià, C/Dr. Castany s/n, M2 Building, 17190, Salt, Girona, Spain.
Cellular and Molecular Neurobiology Research Group, Department of Biology, University of Girona (UdG), Aulari Comú building, C/Maria Aurèlia Capmany 40, 17003, Girona, Spain.
Mol Neurobiol. 2022 Feb;59(2):1320-1332. doi: 10.1007/s12035-021-02644-y. Epub 2022 Jan 5.
Thrombolytic therapy with recombinant tissue plasminogen activator (rt-PA) is currently the only FDA-approved drug for acute ischemic stroke. However, its administration is still limited due to the associated increased risk of hemorrhagic transformation (HT). rt-PA may exacerbate blood-brain barrier (BBB) injury by several mechanisms that have not been fully elucidated. Caveolin-1 (Cav-1), a major structural protein of caveolae, has been linked to the endothelial barrier function. The effects of rt-PA on Cav-1 expression remain largely unknown. Here, Cav-1 protein expression after ischemic conditions, with or without rt-PA administration, was analyzed in a murine thromboembolic middle cerebral artery occlusion (MCAO) and in brain microvascular endothelial bEnd.3 cells subjected to oxygen/glucose deprivation (OGD). Our results show that Cav-1 is overexpressed in endothelial cells of infarcted area and in bEnd.3 cell line after ischemia but there is disagreement regarding rt-PA effects on Cav-1 expression between both experimental models. Delayed rt-PA administration significantly reduced Cav-1 total levels from 24 to 72 h after reoxygenation and increased pCav-1/Cav-1 at 72 h in the bEnd.3 cells while it did not modify Cav-1 immunoreactivity in the infarcted area at 24 h post-MCAO. Importantly, tissue Cav-1 positively correlated with Cav-1 serum levels at 24 h post-MCAO and negatively correlated with the volume of hemorrhage after infarction, the latter supporting a protective role of Cav-1 in cerebral ischemia. In addition, the negative association between baseline serum Cav-1 levels and hemorrhagic volume points to a potential usefulness of baseline serum Cav-1 levels to predict hemorrhagic volume, independently of rt-PA administration.
溶栓治疗用重组组织型纤溶酶原激活剂(rt-PA)是目前唯一获得美国食品药品监督管理局批准用于急性缺血性脑卒中的药物。然而,由于其相关的出血性转化(HT)风险增加,其应用仍然受到限制。rt-PA 可能通过尚未完全阐明的几种机制加剧血脑屏障(BBB)损伤。小窝蛋白-1(Cav-1)是小窝的主要结构蛋白,与内皮屏障功能有关。rt-PA 对 Cav-1 表达的影响在很大程度上仍不清楚。在这里,分析了缺血条件下(有或没有 rt-PA 给药)、在小鼠血栓栓塞性大脑中动脉闭塞(MCAO)和在氧/葡萄糖剥夺(OGD)的脑微血管内皮 bEnd.3 细胞中 Cav-1 蛋白表达。结果表明,缺血后 Cav-1 在梗死区内皮细胞和 bEnd.3 细胞系中过表达,但两种实验模型之间 rt-PA 对 Cav-1 表达的影响存在分歧。延迟 rt-PA 给药可显著降低再复氧后 24 至 72 小时的 Cav-1 总水平,并增加 bEnd.3 细胞中 72 小时的 pCav-1/Cav-1,而在 MCAO 后 24 小时内不改变梗死区的 Cav-1 免疫反应性。重要的是,组织 Cav-1 与 MCAO 后 24 小时的血清 Cav-1 水平呈正相关,与梗死后出血体积呈负相关,后者支持 Cav-1 在脑缺血中的保护作用。此外,基础血清 Cav-1 水平与出血体积之间的负相关表明,基础血清 Cav-1 水平可预测出血体积,与 rt-PA 给药无关。