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

糖尿病（DM）导致发生缺血性卒中的风险增加3-4倍。2型糖尿病卒中 2型糖尿病（T2 DM）患者和动物模型中，缺血性糖尿病（T2 DM）患者和动物模型中的血管和白色物质（WM）损伤增加。 与非DM患者相比，T2 DM患者的脑卒中具有独特的临床模式和不良预后 中风外泌体（Exosomes，Exo）是活性纳米尺寸的生物脂质容器，其运输调节基因和 细胞之间的蛋白质并形成主要的生物通讯管道，促进了大量的生物通讯 应答外泌体中包含的调节分子包括微RNA（miR），其调节细胞内的细胞凋亡。 基因翻译，并在介导广泛的生物功能中发挥主要作用。MicroRNA-126（miR-126） 126)是一种血管生成microRNA，主要在内皮细胞（EC）中表达。特殊条件 敲除EC miR-126（miR-126 EC-/-）小鼠在中风后也具有显著更差的功能结果 降低脑miR-126和ATP结合盒转运蛋白A1（ABCA 1）的表达。外来体 来源于EC（EC-Exo）的细胞具有高水平的miR-126。根据我们强大的初步数据， 开创性的研究，我们提出用EC-Exo治疗中风将增强中风后的神经恢复效果， T2 DM小鼠中风，可能通过miR-126/ABCA 1信号通路。该应用程序包括三个 目标。目的-1：测试EC-Exo对成年男性和女性缺血性脑卒中的治疗效果 T2 DM小鼠。目的-2：评估miR-126是否介导EC-Exo治疗诱导的神经修复 我们将评估EC特异性条件性基因敲除治疗中风的疗效 miR-126（miR-126 EC-/-）和非miR-126敲除对照（miR-126 fl/fl）T2 DM小鼠中的EC-Exo衍生 来自miR-126 EC-/-脑EC（miR-126 EC-/-EC-Exo）或源自野生型miR-126 fl/fl脑EC的EC-Exo （miR-126 fl/fl-EC-Exo）对血管和轴突/WM重构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ABCA 1是否有助于EC-Exo治疗 成年雄性T2 DM小鼠中风后诱导的神经恢复作用，脑特异性敲除小鼠 将使用ABCA 1（ABCA 1-B/-B）和WT ABCA 1敲除对照（ABCA 1 fl/fl）小鼠。在本申请中， 我们是第一个提出，在EC-Exo中包封的miR-126的产生有助于其稳健的表达。 miR-126/ABCA 1通路介导EC-Exo诱导的神经血管生成 和WM重塑，从而改善T2 DM中风神经和认知功能恢复 小鼠该建议具有高度的临床相关性，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.