Characterizing Beta Lactams as Neuroprotectants for Amyotrophic Lateral Sclerosis

星形胶质细胞转运蛋白EAAT1和EAAT2负责前脑谷氨酸转运的最大比例。EAAT2的异常表达/功能在散发性ALS和转基因ALS模型中很常见。此外，该转运蛋白家族各分子亚型的功能改变与脑肿瘤生长、小脑性共济失调、多发性硬化症和癫痫有关。调节这些蛋白的表达可以提供有效的治疗方法来延缓疾病的进展。目前还没有可以激活谷氨酸转运体的实用药理制剂。最近使用EAAT2转基因小鼠的研究提供了令人兴奋的结果 有证据表明，增加EAAT2蛋白/活性可以延缓ALS动物模型的神经退化；减少与癫痫相关的癫痫发作，并延缓脑瘤的生长。最近，NINDS组织了FDA批准的药物筛选，确定β-内酰胺类抗生素是EAAT2的调节剂。我们已经积累了初步数据，几种筛选出的抗生素可以激活EAAT2基因的表达，导致大脑蛋白质增加多达七倍。这些药物的体外和体内作用已经得到验证-它们可以保护培养的神经元/运动神经元免受兴奋性毒性损伤。最后一种β-内酰胺，头孢曲松，可以延缓 在ALS转基因小鼠模型中，即使在疾病开始时给药，也能增强肌肉力量并提高存活率。在这项翻译研究计划中，我们将系统地评估非抗生素β-内酰胺类化合物和β-内酰胺类抗生素作为EAAT1或EAAT2表达调节剂的作用。然后，我们将继续确定最有效的药物(S)，并在ALS的体外相关动物模型中彻底评估这些药物。这些连续的阶段将为未来向合理的临床试验设计的实际转化奠定基础。

The astroglial transporters EAAT1 and EAAT2 are responsible for the largest percentage of glutamate transport in forebrain. Abnormal expression/function of EAAT2 is common to sporadic ALS and to transgenic models of the disease. In addition, altered function of various molecular subtypes of this transporter family is associated with brain tumor growth, cerebellar ataxia, multiple sclerosis and epilepsy. Regulating expression of these proteins could provide powerful therapies to retard disease progression. No practical pharmacological agents exist that can activate glutamate transporters. Studies using EAAT2 transgenic mice recently provide exciting evidence that increasing EAAT2 protein/activity can retard neurodegeneration in ALS animal models; diminish seizures associated with epilepsy, and retard brain tumor growth. A recent NINDS-organized screen of FDA approved drugs, identified beta-lactam antibiotics as modulators of EAAT2. We have accumulated preliminary data that several screened antibiotics can activate EAAT2 gene expression, leading to increased brain protein up to seven fold. The in vitro and in vivo actions of these drugs have been validated- they can protect against excitotoxic injury to cultured neurons/motor neurons. Finally one beta-lactam, ceftriaxone, can delay loss of muscle strength and increase survival in the ALS transgenic mouse model-even when given at disease onset. In this translational research proposal we will systematically evaluate non-antibiotic beta-lactam compounds and beta-lactam antibiotics as modulators of EAAT1 or EAAT2 expression. We will then go on to identify the most potent agent(s) and thoroughly evaluate the drugs in an in vitro-relevant and animal model of ALS. These sequential phases will set the stage for future practical translation towards rational clinical trial design.