Melbourne Dementia Research Centre, The Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Parkville, Victoria, Australia.
J Alzheimers Dis. 2020;77(2):753-771. doi: 10.3233/JAD-200551.
Abnormally hyperphosphorylated tau is a defining pathological feature of tauopathies, such as Alzheimer's disease (AD), and accumulating evidence suggests a role for iron in mediating tau pathology that may lead to cognitive decline in these conditions. The metal chelator deferiprone (DFP), which has a high affinity for iron, is currently in clinical trials for AD and Parkinson's disease. However, the effect of DFP on tau pathology remains underexplored.
We aimed to investigate the impact of chronic DFP treatment on tau pathology using a well-characterized mouse model of tauopathy (rTg(tauP301L)4510).
Animals were treated daily with DFP (100 mg/kg) via oral gavage for 16 weeks. After 14 weeks, mice were tested in the Y-maze, open field, Morris water maze, and rotorod. At the end of the study, brain tissue was collected to examine metal levels (using inductively coupled plasma-mass spectrometry) and for western blot analysis of DFP on tau and iron associated pathways.
DFP significantly reduced anxiety-like behavior, and revealed a trend toward improved cognitive function. This was accompanied by a decrease in brain iron levels and sarkosyl-insoluble tau. Our data also showed downregulation of the tau kinases glycogen synthase kinase 3β and cyclin dependent kinase-5 in DFP treated mice and an increase in the methylation of the catalytic subunit of protein phosphatase 2A.
These data support the hypothesis that suggests that iron plays a neurotoxic role in tauopathies and may be a potential therapeutic target for this class of disorders.
异常过度磷酸化的 tau 是 tau 病的一种定义性病理特征,例如阿尔茨海默病(AD),越来越多的证据表明铁在介导 tau 病理学中起作用,这可能导致这些疾病的认知能力下降。金属螯合剂地拉罗司(DFP)对铁具有高亲和力,目前正在 AD 和帕金森病的临床试验中。然而,DFP 对 tau 病理学的影响仍未得到充分探索。
我们旨在使用 tau 病的一种特征明确的小鼠模型(rTg(tauP301L)4510)研究慢性 DFP 治疗对 tau 病理学的影响。
动物通过口服灌胃每天接受 DFP(100mg/kg)治疗 16 周。在 14 周后,小鼠在 Y 迷宫、旷场、水迷宫和转棒上进行测试。在研究结束时,收集脑组织以检查金属水平(使用电感耦合等离子体质谱法)和 DFP 对 tau 和铁相关途径的 Western blot 分析。
DFP 显著降低了焦虑样行为,并显示出改善认知功能的趋势。这伴随着大脑铁水平和 Sarkosyl 不溶性 tau 的减少。我们的数据还表明,DFP 处理的小鼠中 tau 激酶糖原合酶激酶 3β和周期依赖性激酶-5 的下调以及蛋白磷酸酶 2A 的催化亚基的甲基化增加。
这些数据支持了铁在 tau 病中起神经毒性作用的假说,并可能成为这类疾病的潜在治疗靶点。