MiR-126/ABCA1 mediates exosome induced neurorestorative effects after stroke in T2DM mice

糖尿病(DM)导致发生缺血性中风的风险增加3-4倍。2型糖尿病患者的卒中 (T2 DM)患者和在动物模型中增加缺血的血管和白质(WM)损害 与非糖尿病患者相比，T2 DM患者的脑、卒中具有明显的临床特征和较差的预后 卒中。Exosome(Exo)，是一种活性的纳米级生物脂类容器，它运输调控基因和 细胞之间的蛋白质，并形成一个主要的生物沟通管道，促进过多的生物 回应。外切体中包含的调节分子包括microRNAs(MiRs)，它调节 基因翻译在广泛的生物学功能中起着重要的调节作用。MicroRNA-126(miR- 126)是一种血管生成的microRNA，主要在内皮细胞(EC)中表达。特定条件 EC miR-126(miR-126EC-/-)基因敲除的小鼠在中风后的功能预后也明显恶化 AS降低脑组织miR-126和ATP结合盒转运体A1(ABCA1)的表达。外切体 来源于EC(EC-Exo)的化合物具有高水平的miR-126。根据我们稳健的初步数据，在这方面 开创性研究，我们认为EC-Exo治疗中风将增强神经修复效果 T2 DM小鼠卒中可能通过miR-126/ABCA1信号通路。此应用程序包括三个 目标。目的-1：检测EC-Exo对成年男女缺血性卒中的疗效 T2 DM小鼠。目的-2：评价miR-126是否介导EC-Exo治疗诱导的神经修复 我们将评估在特定条件基因敲除EC中治疗中风的疗效 MiR-126(miR-126EC-/-)和非miR-126基因敲除对照(miR-126fl/fl)T2 DM小鼠的EC-Exo来源 来源于miR-126EC-/-脑内皮细胞(miR-126EC-/-EC-Exo)或来源于野生型miR-126fl/fl脑内皮细胞的EC-Exo (MIR-126FL/FL-EC-Exo)对血管和轴突/WM重塑以及神经和认知功能的影响 结果。目的-3：检测miR-126的间接靶点ABCA1是否参与EC-Exo治疗 成年雄性T2 DM小鼠、脑特异性敲除小鼠卒中后的神经修复作用 将采用ABCA1(ABCA1-B/-B)和WT ABCA1基因敲除对照(ABCA1fl/fl)小鼠。在此应用程序中， 我们首次提出，封装在EC-Exo中的miR-126的生成有助于其健壮性 治疗性修复作用及miR-126/ABCA1通路介导EC-Exo诱导的神经血管 和WM重塑，从而促进T2 DM患者卒中神经和认知功能的恢复 老鼠。这项建议具有很高的临床相关性，如果成功，将显著影响 糖尿病中风，可能还有所有的中风患者。

Diabetes mellitus (DM) leads to a 3-4 fold higher risk of experiencing ischemic stroke. Stroke in type two DM (T2DM) patients and in animal models increases vascular and white matter (WM) damage in the ischemic brain, and stroke in T2DM patients has a distinct clinical pattern and a poor prognosis compared to non-DM stroke. Exosomes (Exo), are active nano size biological lipid containers, which transport regulatory genes and proteins between cells and form a major biological communication conduit, facilitating a plethora of biological responses. The regulatory molecules contained in the exosome include microRNAs (miRs), which regulate gene translation and play primary roles in mediating a vast range of biological functions. MicroRNA-126 (miR- 126) is an angiogenic microRNA and primarily expressed in endothelial cells (EC). Specific conditional knockout of EC miR-126 (miR-126EC-/-) mice have significantly worse functional outcome after stroke as well as decreased brain miR-126 and ATP-binding cassette transporter A1 (ABCA1) expression. Exosomes derived from EC (EC-Exo) have a high level of miR-126. Based on our robust preliminary data, in this pioneering study, we propose that treatment of stroke with EC-Exo will enhance neurorestorative effects after stroke in T2DM mice, possibly, via the miR-126/ABCA1 signaling pathway. This application includes three Aims. Aim-1: To test the therapeutic effects of EC-Exo on cerebral ischemic stroke in adult male and female T2DM mice. Aim-2: To evaluate whether miR-126 mediates EC-Exo treatment induced neurorestorative effects, we will evaluate the therapeutic effects of treatment of stroke in specific conditional knockout of EC miR-126 (MiR-126EC-/-) and in non-miR-126 knockout control (miR-126fl/fl) T2DM mice with EC-Exo derived from miR-126EC-/- brain ECs (miR-126EC-/-EC-Exo) or EC-Exo derived from wild type miR-126fl/fl brain ECs (miR-126fl/fl-EC-Exo) on vascular and axonal/WM remodeling and neurological and cognitive functional outcome. Aim-3: To test whether ABCA1, an indirect target of miR-126, contributes to EC-Exo treatment induced neurorestorative effects after stroke in adult male T2DM mice, mice with specific knockout of brain ABCA1 (ABCA1-B/-B) and WT ABCA1 knockout control (ABCA1fl/fl) mice will be employed. In this application, we are the first to propose that, generation of miR-126 encapsulated in EC-Exo contributes to its robust therapeutic restorative effects and that miR-126/ABCA1 pathway mediates EC-Exo-induced neurovascular and WM remodeling, and thereby improves stroke neurological and cognitive functional recovery in T2DM mice. This proposal is highly clinically relevant and if successful, will significantly impact the treatment of diabetic stroke, and possibly all stroke patients.