Inhibiting pathological TDP-43 phosphorylation as a therapeutic strategy for ALS

TAR DNA结合蛋白43 kDa(TDP-43)是肌萎缩症中主要的聚集性疾病蛋白 侧索硬化症(ALS)90%以上的肌萎缩侧索硬化症病例显示含有洗涤剂的病理损害 磷酸化、截断和泛素化的TDP-43蛋白的不溶沉积。TDP-43 S409/410(pS409/410)的磷酸化是最一致、最稳健和最特异的神经病理 肌萎缩侧索硬化症的特征提示磷酸化的TDP-43(PTDP)介导的神经毒性级联。 此外，pTDP已被证明影响TDP-43在培养细胞中的聚集和在 人类肌萎缩侧索硬化症病例。我们先前的工作证明pS409/410 TDP-43介导运动神经元 家族性肌萎缩侧索硬化症引起的TDP-43突变的毒性。调节TDP-43磷酸化的激酶存在 是ALS治疗干预的一个有吸引力的靶点。我们发现了一种保存完好的TDP-43- 具有翻译潜能的活性激酶称为tau微管蛋白激酶1(TTBK1)。脑的辨认 渗透性TTBK1抑制剂最终可能提供一种可行的药物开发策略。我们 假设TDP-43磷酸化增加会导致ALS运动神经元变性，并且 通过抑制TTBK1抑制pTDP的积聚对TDP-43介导的损伤具有保护作用 肌萎缩侧索硬化症的神经变性。提出了三个综合的具体目标：1)TTBK1的鉴定 选择性的激酶抑制剂。2)TTBK1选择性抑制剂的优化及选择性的验证 PTDP积累的细胞模型中的化合物。3)确认TTBK1在形成中的作用 利用TTBK1基因敲除小鼠和现有的TDP-43蛋白病变转基因模型对pTDP进行了研究。这个 这里提出的研究将为开发TTBK1选择性抑制剂作为候选药物奠定基础 肌萎缩侧索硬化的治疗方法。

TAR DNA-binding protein 43 kDa (TDP-43) is the major aggregating disease protein in amyotrophic lateral sclerosis (ALS). Over 90% of ALS cases exhibit pathological lesions containing detergent insoluble deposits of phosphorylated, truncated, and ubiquitinated TDP-43 protein. TDP-43 phosphorylated at S409/410 (pS409/410) is the most consistent, robust, and specific neuropathological feature of ALS suggesting a phosphorylated TDP-43 (pTDP) mediated cascade of neurotoxicity. Furthermore pTDP has been shown to influence the aggregation of TDP-43 in cultured cells and in human ALS cases. Our previous work demonstrated pS409/410 TDP-43 mediates motor neuron toxicity of familial ALS-causing TDP-43 mutations. Kinases regulating TDP-43 phosphorylation present an attractive target for therapeutic intervention in ALS. We have identified a well-conserved TDP-43- active kinase with translational potential known as tau tubulin kinase 1 (TTBK1). Identification of brain penetrant TTBK1 inhibitors may ultimately provide a viable drug development strategy. We hypothesize that increased TDP-43 phosphorylation drives motor neuron degeneration in ALS and that blocking pTDP accumulation by inhibiting TTBK1 will protect against TDP-43 mediated neurodegeneration in ALS. Three integrated specific aims are proposed: 1) Identification of TTBK1 selective kinase inhibitors. 2) Optimization of TTBK1 selective inhibitors and validation of selective compounds in a cellular model of pTDP accumulation. 3) Validation of the role of TTBK1 in the formation of pTDP using TTBK1 knockout mice and an existing transgenic model of TDP-43 proteinopathy. The studies proposed here will set the stage for development of TTBK1 selective inhibitors as a candidate therapeutic approach for ALS.