Cerebral endothelial derived-exosomes improve cognitive function in aged diabetic rat

摘要： 糖尿病（Diabetes mellitus，DM）是中老年人群常见的代谢性疾病， 与认知能力下降和老年痴呆症风险增加有关。鉴于 人口老龄化的规模不断扩大，糖尿病患病率增加，制定具体的干预措施， 通过抵消DM诱导的病理生理过程来维持认知完整性是主要的临床 重要性临床试验表明，改善血糖控制的成就可能不会阻止 认知障碍的进展。DM引起的认知缺陷的根本原因仍然未知。 外泌体是直径为40 ~ 120 nm的纳米囊泡，介导细胞间通讯 通过将蛋白质、脂质和基因组物质（包括mRNA和microRNA（miRNA））在细胞之间转移， 源细胞和靶细胞。我们的初步数据表明，老年糖尿病大鼠表现出实质性的认知功能， 损伤，这与脑内皮细胞和神经干细胞功能障碍有关。我们也 发现来自DM诱导的功能障碍的脑内皮细胞的外泌体与 和受损的神经干细胞更重要的是，施用从脑组织中分离的外来体， 健康年轻成人脑的内皮细胞对老年糖尿病大鼠有效地改善了认知功能， 最大限度地减少DM诱导的脑内皮细胞和神经干细胞功能障碍。在本申请中，我们 因此，建议开发内皮外泌体作为DM诱导的基于机制的治疗。 老年人认知能力下降。我们的假设是：1）脑内皮细胞外泌体（CEE） 2）CEE治疗改善了老年DM大鼠的脑血管功能， 开放性和完整性，并促进老年DM大鼠的神经发生和少突神经发生，以及3） 携带升高的miR-1和-146a的工程化外泌体对脑血管的影响增强 功能、神经发生和少突胶质细胞发生以及认知功能。目的1是调查是否 来自年轻成年大鼠的CEE改善了老年DM大鼠的认知功能， 在老年雄性和雌性大鼠的DM早期（2个月）或晚期（4个月）阶段给药。目的2 研究CEE治疗是否改善脑血管功能和增强神经发生 和少突胶质细胞的发生。脑血管通畅性和完整性，神经发生和 将测量少突发生。目的3：探讨糖尿病模型大鼠是否存在糖尿病模型大鼠的糖尿病模型。 携带升高的miR-1和miR 146 a的定制的内皮外泌体进一步增强血管功能， 神经发生和少突胶质细胞发生以及认知功能。我们将生成量身定制的CEE， 然后将定制的CEE给予老年DM大鼠。这些研究具有创新性和高度临床相关性。

Abstract: Diabetes mellitus (DM) is a common metabolic disease in the middle-aged and older population, which is associated with cognitive decline and an increased risk of developing dementia in the elderly. Given the growing size of the aging population and increased prevalence of DM, development of specific interventions to maintain cognitive integrity by counteracting DM induced pathophysiological processes is of major clinical importance. Clinical trials show that the achievement of improved glycemic control may not prevent progression of cognitive impairment. The underlying cause of DM-induced cognitive deficits remains unknown. Exosomes are nanovesicles with a size of 40 to 120 nm in diameter and mediate intercellular communication by transferring proteins, lipids, and genomic materials including mRNAs and microRNAs (miRNAs) between source and target cells. Our preliminary data demonstrated aged-DM rats exhibit substantial cognitive impairment, which is associated with dysfunction of cerebral endothelial cells and neural stem cells. We also found that exosomes derived from dysfunctional cerebral endothelial cells induced by DM communicated with and damaged neural stem cells. More importantly, administration of exosomes isolated from cerebral endothelial cells of healthy young adult brain to aged-DM rats effectively improved cognitive function and minimize DM-induced dysfunction of cerebral endothelial cells and neural stem cells. In this application, we therefore, propose to develop the endothelial exosomes as a mechanism-based therapy for DM-induced cognitive decline in aged population. Our hypotheses are: 1) The cerebral endothelial exosome (CEE) treatment reduces cognitive deficits in the aged-DM rat, 2) The CEE treatment improves cerebral vascular patency and integrity, and promotes neurogenesis and oligodendrogenesis in the aged-DM rat, and 3) Engineered exosomes carrying elevated miR-1 and -146a have enhanced effects on cerebral vascular function, neurogenesis and oligodendrogenesis as well as cognitive function. Aim 1 is to investigate whether the CEE derived from young adult rats improve cognitive function in the aged-DM rat, when the CEE is administered at an early (2 months) or advanced (4 months) stage of DM in aged male and female rats. Aim 2 is to investigate whether the CEE treatment improves cerebral vascular function and enhances neurogenesis and oligodendrogenesis in the aged-DM rat. Cerebral vascular patency and integrity, neurogenesis and oligodendrogenesis will be measured. Aim 3 is to investigate whether treatment of the aged-DM rat with tailored endothelial exosomes carrying elevated miR-1 and miR146a further enhances vascular function, neurogenesis and oligodendrogenesis as well as cognitive function. We will generate the tailored CEE and then administer the tailored CEE to aged-DM rats. These studies are innovative and highly clinically relevant.