Targeting blood-derived integrin signaling after stroke

项目摘要。我们发现，雌性小鼠，而不是雄性小鼠，血浆玻连蛋白（VTN）水平增加 在暂时性大脑中动脉闭塞中风后， （MCAO）。VTN的这种女性特有的有害作用可能与女性有关，因为女性的VTN更严重。 卒中后的功能性神经功能结局。因此，该提案侧重于雌性小鼠。我们还发现 VTN在MCAO后泄漏到脑中并诱导促炎细胞因子表达。我们的体外和 体内数据表明VTN通过特异性α v整联蛋白和可能通过uPAR起作用。整合素激活 通过粘着斑激酶（FAK）的细胞内信号传导。全身注射FAK的雌性小鼠 抑制剂6小时后中风有更好的更好的结果。这些数据表明，VTN-整合素-FAK 信号传导有助于中风后的组织损失。目标1将确定是否存在个体差异， MCAO后血液中VTN水平的增加预示着炎症反应和脑组织的损失。 这可能会提供一个额外的预后中风标志物，并开辟新的机会，开发治疗。 我们还将确定VTN和FAK抑制是否通过星形胶质细胞或小胶质细胞FAK起作用，两个早期 已知对炎症有显著贡献的应答细胞类型。我们会找出最有效的 MCAO后时间和FAK抑制剂全身治疗的持续时间，以改善结局，包括 长期的运动功能，并在老年“绝经后”雌性小鼠中进行测试， 主要发生在老年人中，绝经后的结果更糟。FAK抑制剂目前正在进行临床试验， 癌症，而且似乎耐受良好。目的2将定义特定VTN受体介导的程度， VTN的影响，使用药理学和遗传学的方法后MCAO在体内。这一目标将有助于 确定可能比FAK抑制更具选择性的分子靶点和治疗。目标3将定义 MCAO后雌性脑中较高的IL-6诱导是否具有神经保护作用，如已报道的 男性，以及中风后较高的血液IL-6水平是否有助于诱发VTN。我们将 还可以确定女性性激素是否调节VTN，以及VTN是否抵消了保护性激素。 雌激素和孕激素的作用。总之，这些研究集中在一个新的和独特的分子靶点 这会导致更糟糕的结果，并将为中风后的药物治疗提供新的途径， 也许是专门针对女性的。

Project Summary. We found that female, but not male, mice have increased plasma vitronectin (VTN) levels and less tissue loss upon genetic VTN deletion after a stroke by temporary middle cerebral artery occlusion (MCAO). This female-specific detrimental role of VTN may be relevant to women because that have worse functional neurological outcomes after stroke. Therefore, this proposal focuses on female mice. We also find that VTN leaks into the brain after MCAO and induces pro-inflammatory cytokine expression. Our in vitro and in vivo data suggest that VTN acts through specific av integrins and possibly through uPAR. Integrins activate intracellular signaling through focal adhesion kinase (FAK). Female mice injected systemically with an FAK inhibitor 6 h after a stroke had better much better outcomes. These data suggest that VTN-Integrin-FAK signaling contributes to tissue loss after stroke. Aim 1 will determine whether individual differences in increased VTN levels in the blood seen after MCAO predict the inflammatory response and loss of brain tissue. This might provide an additional prognostic stroke marker and open new opportunities to develop treatments. We will also determine whether VTN and FAK inhibition act through astroglial or microglial FAK, two early responder cell types with known significant contributions to inflammation. We will identify the most efficacious post-MCAO time and duration of systemic treatments with the FAK inhibitor to improve outcomes, including long-term locomotor function and also test this in aged “post-menopausal” female mice because stroke occurs mainly in older people, with worse outcomes after menopause. FAK inhibitors are currently in clinical trials for cancer and seem to be well tolerated. Aim 2 will define the extent to which the specific VTN receptors mediate the VTN effects, using pharmacological and genetic approaches after MCAO in vivo. This aim will help to identify molecular targets and treatments that may be more selective than FAK inhibition. Aim 3 will define whether the higher IL-6 induction in the female brain after MCAO is neuroprotective, as has been reported for males, and whether blood IL-6 levels, which are higher after stroke, contribute to induction of VTN. We will also determine whether female sex hormones regulate VTN and whether VTN counteracts the protective effects of estrogen and progesterone. Together, these studies focus on a novel and unique molecular target that contributes to worse outcomes, and will provide new avenues for developing drug treatments after stroke, perhaps specifically for women.