Perlecan Domain V as a therapeutic VCID strategy for the clearance of amyloid beta from the brain in cerebral amyloid angiopathy

项目摘要/摘要 血管对认知损害和痴呆的贡献(VCID)包括脑血管频谱 脑部小血管疾病的变化，包括脑淀粉样血管病(CAA) 病理性淀粉样β蛋白(Aβ)积聚在大脑毛细血管和动脉壁中。随着不断增加 年龄、中青年高脂血症，脑壁A-β清除失败 毛细血管和动脉导致CAA。从大脑中消除β的关键机制之一是 沿细胞外基质(ECM)组成的毛细血管和动脉基底膜，作为壁内 动脉周围引流(IPad)。除其他因素外，老化会改变ECM的结构，导致 β的ipad失败了。此外，脑血管重塑和血管生成可能代表早期 VCID中出现的血流减少的代偿性变化，部分是通过增加蛋白水解物发生的 周转周转等周转ECM。我们已经证明了Perlecan结构域V(DV)蛋白 大大降低淀粉样蛋白的毒性，同时增强血管生成。人类慢性再生障碍性贫血患者缺乏通透性 仅在淀粉样阳性血管上染色。总的来说，这些研究提供了令人震惊的证据，表明 培莱康在脑血管Aβ沉积中的作用及其相关的有害作用。最后，蛋白多糖 可影响对β至关重要的内皮转运蛋白机制，如P-糖蛋白(P-gp) 从大脑中消除，这也会随着年龄的增长而减弱。IPad负担的增加与血脑相关 血脑屏障的破坏，最终加剧了Aβ在大脑中的沉积，从而导致VCID。AS 脑血管基膜随年龄变化，对改善iPad的ECM的干预 可能是一种早期的、关键的和治疗相关的方法来预防CAA和 VCID。这里我们假设DV在β的血管清除中起着重要的内源性作用 这可以在治疗上利用与iPad相关的VCID变化。为了支持这一假设， 初步数据表明：1.DV通过增加P-gp的表达和活性来增加HA-β的清除。 体外脑微血管，2.DV增加体外WT小鼠来源的BEC对HAβ的转运，3.小鼠 已确定的10%的总正常Perlecan和DV水平(称为PLN-/-)已损害iPad 通过壁上有Aβ的毛细血管和小动脉的数量更多(与注射β的WT对照组相比) 立体定向注射Aβ和4.PLN-/-来源的BEC缺乏可被DV挽救的β转运 体外治疗。有了这些结果，我们建议分析DV介导的Aβ清除增加 以及确定DV在脑血管内皮细胞中的作用和治疗潜力。 Aβ的ipad和实验性的CAA。

PROJECT SUMMARY/ABSTRACT Vascular contributions to cognitive impairment and dementia (VCID) encompass a spectrum of cerebrovascular changes seen in small vessel diseases of the brain including cerebral amyloid angiopathy (CAA) where pathologic amyloid beta (Aβ) protein accumulates in the walls of cerebral capillaries and arteries. With increasing age, and with hyperlipidemia in early to mid-life, there is a failure of clearance of Aβ along the walls of cerebral capillaries and arteries resulting in CAA. One of the key mechanisms for the elimination of Aβ from the brain is along the extracellular matrix (ECM)-composed basement membranes of capillaries and arteries, as intramural periarterial drainage (IPAD). Aging, among other factors, changes the structure of the ECM, resulting in the failure of IPAD of Aβ. Furthermore, cerebrovascular remodeling and angiogenesis may represent early compensatory changes to the reduced blood flow seen in VCID and occur in part by increasing the proteolytic turnover of the surrounding ECM such as perlecan. We have demonstrated that perlecan domain V (DV) protein greatly reduces amyloid toxicity while enhancing angiogenesis. Human CAA patients showed a lack of perlecan staining only on amyloid positive vessels. Collectively, these studies offer striking evidence to suggest a critical role of perlecan in cerebrovascular Aβ deposition and its associated deleterious effects. Lastly, proteoglycans can have effects on endothelium transporter mechanisms such as P- glycoprotein (P-gp) which are vital to Aβ elimination from the brain, which also fail with age. This increased burden on IPAD correlates to blood-brain barrier (BBB) disruption, ultimately worsening Aβ deposition in the brain, which contributes to VCID. As cerebrovascular basement membranes change with age, interventions upon the ECM that improve IPAD may represent an early, critical, and therapeutically relevant approach for the prevention of CAA and VCID. Here we hypothesize that DV plays an important endogenous role in vascular clearance of Aβ which can be therapeutically exploited in IPAD-related changes in VCID. In support of this hypothesis, preliminary data suggest that: 1. DV increases hAβ clearance by increasing P-gp expression and activity in cerebral microvessels in vitro, 2. DV increases hAβ transit across WT mice-derived BECs in vitro, 3. mice that express 10% of total normal perlecan and DV levels (referred to as Pln-/-) have impaired IPAD as determined by a higher number of capillaries and arterioles with Aβ in their walls (compared to Aβ-injected WT controls) after stereotactic injection of Aβ, and 4. Pln-/- - derived BEC’s have deficient Aβ transit that can be rescued by DV treatment in vitro. Armed with these results, we propose to analyze DV-mediated increased clearance of Aβ across brain endothelial cells in mechanistic detail, and to determine the role and therapeutic potential of DV on IPAD of Aβ and experimental CAA.