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

7.项目摘要/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神经磷酸酶(CN)的潜力。 阿尔茨海默病(AD)的抑制策略。小猎犬在新陈代谢方面与人类相似，并自发地 高龄时出现淀粉样蛋白(Aβ，Aβ)沉积。因此，老化的小猎犬模型已经显示 在几个备受瞩目的抗阿尔茨海默病药物试验中具有特殊的预测有效性。我们的分子靶标 治疗策略CN最近已成为AD病理生理学的关键机制。CN的征兆 在人类和阿尔茨海默病小鼠模型中，多动症在认知衰退的早期阶段被发现。研究 在众多实验室中，使用各种实验模型，表明CN活动既是 对于包括Aβ沉积在内的关键AD生物行为标记物的进展是必要的和充分的， 神经变性、神经炎症/神经胶质细胞激活、突触功能障碍和认知丧失。为了抑制CN， 我们将使用FDA批准的预防同种异体移植排斥反应的药物他克莫司和二线药物 治疗多种免疫/炎症性疾病。在动物模型中，他克莫司表现出强大的抗 具有发炎、神经保护和延年益寿的功效。此外，最近的一项流行病学调查 研究发现，人类肾移植患者服用以下药物可显著降低痴呆症的发病率 他克莫司，相对于普通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为期一年的行为/认知筛查。在6-7点 几个月龄(在出现明显的淀粉样变之前)，狗将被分成两组 认知状态相匹配。其中一组连续口服他克莫司(0.075 mg/kg/天)。 未来两年，而另一组将接受安慰剂。目标1将评估多领域认知和 通过他克莫司在多个时间点测量血液和脑脊液生物标记物(例如，Aβ和细胞因子) 治疗期。目标2将使用MRI/MRS来测量脑血流灌注的纵向变化，脑 新陈代谢和结构完整性。目标3将使用免疫组织化学和各种生化分析 评估AD生物标志物(例如Aβ沉积、胶质细胞激活、突触丢失和神经变性)和CN- 相关信号参数(例如，细胞类型特异性表达、CN蛋白降解和NFAT激活) 死后脑组织。这些研究将对AD的CN假说进行严格的检验，并可能 为研究CN抑制在人类AD中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.