Characterizing Beta Lactams as Neuroprotectants for Amyotrophic Lateral Sclerosis

星形胶质细胞转运体EAAT 1和EAAT 2负责前脑中最大百分比的谷氨酸转运。EAAT 2的异常表达/功能在散发性ALS和该疾病的转基因模型中是常见的。此外，该转运蛋白家族的各种分子亚型的功能改变与脑肿瘤生长、小脑共济失调、多发性硬化和癫痫相关。调节这些蛋白质的表达可以提供有效的治疗方法来延缓疾病的进展。不存在可以激活谷氨酸转运蛋白的实用药理学试剂。最近使用EAAT 2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EAAT 2蛋白/活性可以延缓ALS动物模型中的神经变性;减少与癫痫相关的癫痫发作，并延缓脑肿瘤生长。最近NINDS组织的FDA批准药物筛选，确定β-内酰胺抗生素为EAAT 2的调节剂。我们已经积累了初步数据，表明几种筛选的抗生素可以激活EAAT 2基因表达，导致大脑蛋白质增加高达7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，可以延迟 肌肉力量和增加ALS转基因小鼠模型的存活率-即使在疾病发作时给予。在这项转化研究计划中，我们将系统地评估非抗生素β-内酰胺化合物和β-内酰胺抗生素作为EAAT 1或EAAT 2表达的调节剂。然后，我们将继续确定最有效的药物，并在ALS的体外相关和动物模型中彻底评估药物。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.