Preclinical evaluation of tacrolimus in a canine model of Alzheimer's disease

7.项目总结/摘要 该项目使用老化的比格犬和纵向治疗设计来测试钙调磷酸酶（CN）的潜力。 阿尔茨海默病（Alzheimer's disease，AD）的治疗策略。比格犬的代谢与人类相似， 随着年龄的增长，淀粉样蛋白-β（Aβ）沉积。因此，老化的比格犬模型显示， 在几项备受瞩目的抗AD药物试验中具有出色的预测效度。我们的分子靶点 治疗策略CN最近已成为AD病理生理学的关键机制。CN的标志 在人类和AD小鼠模型中认知衰退早期发现了活动过度。研究 在众多实验室中使用各种实验模型进行的研究表明，氯化萘的活性 对于关键AD生物行为标志物（包括Aβ沉积）的进展是必要和充分的， 神经变性、神经炎症/神经胶质活化、突触功能障碍和认知丧失。为了抑制CN， 我们将使用他克莫司，一种FDA批准的预防同种异体移植排斥反应的药物， 治疗多种免疫/炎症疾病。在动物模型中，他克莫司表现出有效的抗- 炎症，神经保护，也许还有延长寿命的特性。此外，最近流行的 一项研究发现，在人类肾移植患者中， 他克莫司，相对于一般人群中年龄匹配的受试者。 在这个项目中，5-6个月大的比格犬将接受1年的行为/认知筛查。在6-7 月龄时（在发生显著的淀粉样蛋白病理学之前），将狗分成两组 与认知状态匹配一组将连续接受他克莫司（0.075 mg/kg/天，口服）， 在接下来的两年里，另一组将接受安慰剂。目标1将评估多领域认知， 在他克莫司治疗期间的多个时间点测量血液和CSF生物标志物（例如Aβ和细胞因子） 治疗期。目的2将使用MRI/MRS测量脑灌注、脑 新陈代谢和结构完整性。目的3将使用免疫组织化学和各种生化测定 评估AD生物标志物（例如Aβ沉积、神经胶质活化、突触丢失和神经变性）和CN- 相关的信号传导参数（例如细胞类型特异性表达、CN蛋白水解和NFAT活化）， 死后的脑组织这些研究将为AD的CN假设提供严格的检验， 为研究CN抑制是否是人类AD的主要或补充治疗策略铺平道路 临床试验

7. Project Summary/Abstract This project uses aging beagles and a longitudinal treatment design to test the potential of a calcineurin (CN) inhibiting strategy in Alzheimer's disease (AD). Beagles are metabolically similar to humans and spontaneously develop amyloid-β (Aβ) deposition with advanced age. Consequently, the aging beagle model has shown exceptional predictive validity in regard to several high-profile anti-AD drug trials. The molecular target of our treatment strategy, CN, has recently emerged as a key mechanism for AD pathophysiology. Signs of CN hyperactivity are found during early stages of cognitive decline in humans and in mouse models of AD. Studies across numerous laboratories, using a variety of experimental models, suggest that CN activity is both necessary and sufficient for the progression of key AD biobehavioral markers including Aβ deposition, neurodegeneration, neuroinflammation/glial activation, synapse dysfunction, and cognitive loss. To inhibit CN, we will use tacrolimus, an FDA-approved drug for the prophylaxis of allograft rejection and a second line treatment for numerous immune/inflammatory disorders. In animal models, tacrolimus exhibits potent anti- inflammatory, neuroprotective, and perhaps lifespan extending properties. Moreover, a recent epidemiological study found that the incidence of dementia was strikingly reduced in human kidney transplant patients taking tacrolimus, relative to age-matched subjects in the general population. In this project, 5-6 month old beagles will undergo 1 year of behavioral/cognitive screening. At 6-7 months-of age (prior to the development of significant amyloid pathology), dogs will be sorted into two groups matched for cognitive status. One group will received tacrolimus (.075mg/kg/day, orally) continuously for the next two years, while the other group will receive placebo. Aim 1 will assess multidomain cognition and measure blood and CSF biomarkers (e.g. Aβ and cytokines) at multiple time points across the tacrolimus treatment period. Aim 2 will use MRI/MRS to measure longitudinal changes in cerebral perfusion, brain metabolism, and structural integrity. Aim 3 will use immunohistochemistry and a variety of biochemical assays to assess AD biomarkers (e.g. Aβ deposition, glial activation, synapse loss, and neurodegeneration) and CN- related signaling parameters (e.g. cell-type specific expression, CN proteolysis, and NFAT activation) in postmortem brain tissue. These studies will provide a rigorous test of the CN hypothesis of AD and possibly pave the way for investigating CN inhibition has a primary or complimentary treatment strategy in human AD clinical trials.