Cerebral Arteriole Structure/Function in Diabetic Ischemic Brain Injury

在580万患有痴呆症的美国人中，有一半以上的人患有血管性痴呆症。 损伤和痴呆症（VCID），对此没有有效的治疗方法。重点关注神经元 这种疾病的病理学限制了我们对促进肿瘤生长的细胞/分子机制的理解， 神经胶质血管（NGV）界面认知功能下降的发生和进展，并阻止了 制定有效的治疗策略。虽然已知糖尿病会增加风险， 由于VCID的严重性，糖尿病实验VCID研究的不充分整合扩大了这一巨大的 知识差距。这一更新提案的具体目标是通过定义蜂窝网络， 以糖尿病和中风为疾病，导致NGV单位进行性破坏的机制 模型虽然神经系统疾病长期以来一直被归类为血管性、神经退行性或 炎症，现在认识到这些机制是交织在一起的。我们过去令人兴奋的发现 资助期使我们专注于NGVU内复杂相互作用的机制：1）糖尿病男性和 雌性大鼠表现出认知缺陷，在中风后恶化，并伴有广泛的 NGV界面的重塑，2）在初始损伤中存活的细胞失去其神经营养/促血管生成功能， 特性，并成为男女发炎，3）成熟的脑源性神经营养因子（mBDNF）是 在糖尿病脑中，促凋亡的proBDNF及其同源受体p75 NTR减少，而促凋亡的proBDNF及其同源受体p75 NTR增加， 脑微血管内皮细胞（BMVECs），4）与对照组大鼠不同， 抗/促炎性小胶质细胞中风后，糖尿病大鼠显示持续的促炎性小胶质细胞， 中风后早期小胶质细胞敲低可改善感觉运动和认知结果，5） 缺血性损伤后糖尿病大鼠内皮细胞衰老标记物的表达增强，6）白细胞介素-1 (IL-1在炎症应激下，BMVECs中其受体和磷酸化tau（p~tau）增加， 7)西洛他唑，一种临床批准的血管扩张剂，具有抑制衰老/抗炎特性，目前 预防中风幸存者进行性认知障碍的临床试验， 炎症以及认知功能的影响。两个目标与翻译和机制的研究将测试 中心假设是糖尿病介导的内皮过早衰老促进血管营养 解偶联和内皮tau病理学，共同传播衰老相关的炎症， 脑损伤后NGVU导致进行性VCID。目的1将确定内皮细胞的因果作用， （e）糖尿病中进行性VCID的衰老，通过定义a）a）细胞特异性抑制VCID的影响， 在VCAM 1标记的细胞中通过内皮（e）p16敲低或西洛他唑鼻内递送的衰老 纳米颗粒对NGVU衰老/功能障碍和认知缺陷的演变的影响 成像质谱细胞术和复杂的自动化行为分析; B）e- 使用超灵敏的VCAM 1标记的分子磁共振成像（mMRI）检测炎症; c） 西洛他唑对两种性别认知能力下降的影响比较;和d）最有效的策略， e-衰老的消除改善了VCID。目标2将确定e-衰老的机制 通过定义双特异性酪氨酸磷酸化调节激酶的作用驱动NGVU衰老 B）内皮细胞IL 1 R1沉默对IL 1 R1介导的p~tau和mBDNF降低的影响; 认知缺陷;以及c）使用创造性媒体的电子衰老对NGVU衰老和功能的影响 转移实验鉴于退伍军人不成比例地患有心脏代谢风险因素和VCID， 确定创新和有效的基于机制的治疗方法， 和/或抑制认知损害的发作和进展，包括快速转化的增龄抑制剂， 通过重新利用西洛他唑进行治疗，将对人类健康和VA使命产生重大影响。

Over half of the 5.8 million Americans who suffer from dementia have Vascular contributions to Cognitive Impairment and Dementia (VCID), for which there are NO effective treatments. The focus on neuronal pathologies of the disease limited our understanding of the cellular/molecular mechanisms that promote the onset and progression of cognitive decline at the neural-glial-vascular (NGV) interface and stalled the development of any effective therapeutic strategies. While it is known that diabetes increases the risk and severity of VCID, the inadequate integration of diabetes experimental VCID research has widened this vast knowledge gap. The specific objective of this renewal proposal is to address these gaps by defining cellular mechanisms contributing to the progressive disruption of the NGV unit using diabetes and stroke as disease models. While neurological diseases have long been categorized as vascular, neurodegenerative or inflammatory, it is now recognized that these mechanisms are interwoven. Our exciting findings in the past funding period led us to focus on the mechanisms of complex interaction within the NGVU: 1) diabetic male and female rats display cognitive deficits that are worsened after stroke and accompanied by exhibit extensive remodeling at the NGV interface, 2) cells that survive initial injury lose their neurotrophic/proangiogenic properties and become inflamed in both sexes, 3) mature brain derived neurotrophic factor (mBDNF) is decreased while proapoptotic proBDNF & its cognate receptor p75NTR are increased in the diabetic brain and brain microvascular endothelial cells (BMVECs), 4) unlike control rats that show a dynamic switch between anti/pro-inflammatory microglia after stroke, diabetic rats display sustained proinflammatory microglia and microglia knockdown in the early poststroke period improves sensorimotor and cognitive outcomes, 5) endothelial expression of senescent markers is amplified in diabetic rats after ischemic injury, 6) interleukin-1 (IL-1), its receptor and phosphorylated tau (p~tau) are increased in BMVECs under inflammatory stress, and 7) cilostazol, a clinically approved vasodilator with senostatic/anti-inflammatory properties that is on current clinical trials for the prevention of progressive cognitive impairment in stroke survivors, improves endothelial inflammation as well as cognition in diabetic rats. Two aims with translational and mechanistic studies will test the central hypothesis is that diabetes-mediated premature endothelial senescence promotes vasotrophic uncoupling and endothelial tau pathology, collectively propagating senescence-associated inflammation within the NGVU after brain injury leading to progressive VCID. Aim 1 will determine the causal role of endothelial (e)senescence in progressive VCID in diabetes by defining a) a) the impact of cell specific inhibition of senescence via endothelial (e)p16 knockdown or intranasal delivery of cilostazol in VCAM1-tagged nanoparticles on the evolution of NGVU senescence/dysfunction and cognitive deficits using innovative Hyperion imaging mass cytometry and complex automated behavior analyses; b) tempora/spatial development of e- inflammation using ultra-sensitive VCAM1-tagged molecular magnetic resonance imaging (mMRI); c) the comparative impact of cilostazol on cognitive decline in both sexes; and d) the most effective tactics by which elimination of e-senescence improves VCID. Aim 2 will determine the mechanisms by which e-senescence drives NGVU senescence by defining a the role(s) of dual specificity tyrosine phosphorylation-regulated kinase 1A (DYRK1A) in IL1R1-mediated p~tau and mBDNF decrease; b) the impact of endothelial IL1R1 silencing on cognitive deficits; and c) the impact of e-senescence on NGVU senescence and functions using creative media transfer experiments. Given that Veterans disproportionately suffer from cardiometabolic risk factors and VCID, identification of innovative and effective mechanism-based therapeutic approaches that would prevent, retard and/or dampen the onset and progression of cognitive impairment, including a rapidly translatable senostatic therapy by repurposing of cilostazol, will have a significant impact on human health and the VA mission.