Guanabenz in the treatment of mutant SOD1 ALS mice

描述（由申请人提供）：我们计划的研究可能为肌萎缩侧索硬化症（ALS）提供新的靶点和治疗方向，ALS是一种无法治愈的致命疾病。突变体（mt）SOD 1被认为是导致家族性ALS（FALS）的原因，因为功能的增加可能涉及蛋白质的错误折叠。我们最近发表的数据表明，PERK的单倍不足（作为未折叠蛋白反应[UPR]的一部分，导致eIF 2的磷酸化，随后抑制翻译）加速了G85 R mtSOD 1 FALS转基因小鼠的疾病，并且初步未发表的数据表明，GADD 34的敲低（使eIF 2去磷酸化）改善了疾病。这些数据导致了这一提议的假设：PERK和PERK通路的增强将改善疾病。在具体目标I中，我们将测试FDA批准的药物guanabenz在改善G85 R mtSOD 1 FALS小鼠疾病方面的疗效。Guanabenz以前被证明可以促进组织培养细胞中羊瘙痒症朊蛋白（PrPsc）（一种错误折叠的蛋白质）的清除，并显着延长PrPsc转基因小鼠的存活时间。Guanabenz最近被发现与蛋白磷酸酶1的调节亚基PPP 1 R15 A/GADD 34结合，选择性地破坏应激诱导的eIF 2的去磷酸化。胍那苄是一种特别有吸引力的用于治疗FALS的药物，因为关于其药代动力学已知很多（例如，已知其可穿过血脑屏障）和安全性，因为其目前用作抗高血压药。在特定目标II中，我们计划在应激反应被触发之前激活PERK，并且还在ER应激期间将PERK增强到高于正常内源性水平（例如，疾病期间）。我们将使用腺相关病毒9（AAV 9）来递送Fv 2 E-PERK，其含有融合到蛋白模块的PERK的激酶结构域（其通常通过二聚化激活）。即使在没有应激反应的情况下，施用小的二聚化分子（AP 20187）也会导致PERK活化。我们的研究结果将对散发性ALS以及FALS具有意义，因为：最近的数据表明，散发性ALS也可能涉及SOD 1蛋白或其活性的异常; TDP-43与散发性ALS和FALS有关，具有与UPR的潜在相互作用，因为TDP-43在这些疾病中错误折叠，并且因为TDP-43是应激颗粒的成分-这可能是普遍定期审议的结果。

DESCRIPTION (provided by applicant): Our planned studies may provide new targets and treatment directions in amyotrophic lateral sclerosis (ALS), a fatal disease with no cure. Mutant (mt) SOD1 is thought to cause familial ALS (FALS) because of a gain in function probably involving misfolding of the protein. We recently published data that show that haploinsufficiency of PERK (which as part of the unfolded protein response [UPR] leads to phosphorylation of eIF2¿ with a subsequent suppression of translation) accelerates disease in G85R mtSOD1 FALS transgenic mice and have preliminary unpublished data that show that a knockdown of GADD34 (which dephosphorylates eIF2¿) ameliorates disease. These data have led to the hypothesis underlying this proposal: an enhancement of PERK and the PERK pathway will ameliorate disease. In Specific Aim I, we will test the efficacy of an FDA-approved drug, guanabenz, in ameliorating disease in G85R mtSOD1 FALS mice. Guanabenz was previously shown to promote clearance of scrapie prion protein (PrPsc) (a misfolded protein) in tissue-culture cells and also to significantly prolong survival of PrPsc transgenic mice. Guanabenz was very recently found to bind to a regulatory subunit of protein phosphatase 1, PPP1R15A/GADD34, selectively disrupting the stress-induced dephosphorylation of eIF2¿. Guanabenz is an especially attractive drug for the treatment of FALS because a great deal is known about its pharmacokinetics (e.g., it is known to cross the blood-brain barrier) and safety due to its present use as an antihypertensive. In Specific Aim II, we plan to activate PERK before the stress response is triggered, and also enhance PERK above the normal endogenous levels during ER stress (e.g., during disease). We will use adeno-associated virus9 (AAV9) to deliver Fv2E-PERK, which contains the kinase domain of PERK (that is normally activated by dimerization) fused to a protein module. Administration of a small dimerizer molecule (AP20187) leads to PERK activation, even in the absence of a stress response. The results of our studies will have implications for sporadic ALS as well as FALS because: recent data suggest that sporadic ALS may also involve abnormalities in the SOD1 protein or its activity; TDP-43, which is implicated in sporadic ALS and FALS, has potential interactions with the UPR since TDP-43 is misfolded in these diseases and because TDP-43 is a constituent of stress granules-which can form as a result of the UPR.