Rapalog Therapy in Heritable and Vigabatrin-Induced GABA Metabolic Disorders

作为主要的抑制性神经递质，超生理学GABA可以干扰自噬，导致细胞内 线粒体数量和氧化应激，雷帕洛格药物(雷帕霉素，Torin 1)通过 与自噬调节因子mTOR(雷帕霉素的机械靶标)的相互作用。GABA相关的病理学是 表现在遗传和药物诱导的状态，包括可遗传的琥珀酸半醛脱氢酶 缺乏(SSADHD)和抗癫痫药物(AED)Vigabatrin(VGB)的干预，其不可逆转 GABA转氨酶失活(GABA-T)在AEDs中是唯一的机制。长期VGB 然而，干预(FDA批准的唯一治疗婴儿痉挛的方法)由于 视网膜毒性的发展。假设1假设涉及GABA、mTOR和 Rapalog可以缓解线粒体功能，为遗传性、 或药物所致(Vgb)、GABA-T和SSADH功能障碍。假设2假设拉帕洛格应用于 局部(眼)联合VGB将减轻视网膜毒性，扩大这种AED的应用范围。目标1 长期给野生型小鼠服用临床相关剂量的VGB，随后表征 全身/眼部影响和拉帕罗格减轻病理的潜力。Aim 1a将使用视觉诱发 视觉大脑皮层的电位(VEP)来评估VGB眼(视网膜)毒性，而目标1b是系统的 用光镜/电子显微镜和免疫组织化学方法检查VGB处理的小鼠的视网膜 与VGB诱导的毒性相关的细胞层。目的2评价临床前雷帕洛格的疗效 在SSADHD小鼠模型中给药。目的2a审问神经行为和神经生理学 雷帕洛格干预对aldh5a1/-小鼠的影响，而Aim 2b则检测雷帕洛格逆转细胞的效果 信号-自噬-mTOR异常，结合药物安全性和安全性的初步体外评估 毒性。我们将使用方差分析来了解雷帕洛格干预对表型的影响，以及他们的 交互作用，随后进行调整后的特别t检验。雷帕洛格在慢性阻塞性肺疾病患者中的临床评价 遗传性结节性硬化症为将我们的临床前结果转换到床边提供了先例。 消除vgb视网膜毒性的药物将在癫痫方面具有巨大的临床价值。 治疗学。这些药物也将对SSADHD具有治疗意义，同时可能导致新的 GABA升高的其他疾病(自闭症、成瘾、唐氏综合症)的治疗范例 具有病理生理作用，进一步突出了我们的提案的广泛临床影响。

Supraphysiological GABA, the primary inhibitory neurotransmitter, can disrupt autophagy resulting in increased mitochondrial number and oxidative stress, an effect mitigated by rapalog drugs (rapamycin, Torin 1) via interaction with the autophagy regulator, mTOR (mechanistic target of rapamycin). GABA-related pathology is manifest in genetic and drug-induced states, including heritable succinate semialdehyde dehydrogenase deficiency (SSADHD), and intervention with the antiepileptic drug (AED) vigabatrin (VGB), whose irreversible inactivation of GABA-transaminase (GABA-T) is mechanistically unique among AEDs. Long-term VGB intervention (the sole FDA-approved treatment for infantile spasms), however, is curtailed due to the development of retinal toxicity. Hypothesis 1 posits that autophagic pathways involving GABA, mTOR and mitochondrial function can be mitigated with rapalogs that will provide clinical benefit in patients with heritable, or medication-induced (VGB), dysfunction of GABA-T and SSADH. Hypothesis 2 posits that rapalogs applied locally (eye), in combination with VGB, will ameliorate retinal toxicity and extend the utility of this AED. Aim 1 chronically administers VGB to wild type mice in clinically relevant dosages, followed by characterization of systemic/ocular effects and the potential of rapalogs to mitigate pathology. Aim 1a will employ visual evoked potentials (VEPs) in the visual cerebral cortex to assess VGB ocular (retinal) toxicity, while aim 1b systematically examines the retina of VGB-treated mice using light/electron microscopy and immunohistochemistry to pinpoint cell layers associated with VGB-induced toxicity. Aim 2 evaluates the efficacy of preclinical rapalog administration in a murine model of SSADHD. Aim 2a interrogates the neurobehavioral and neurophysiological effects of rapalog intervention in aldh5a1-/- mice, while aim 2b examines the efficacy of rapalogs in reversing cell signaling-autophagy-mTOR abnormalities, coupled to a preliminary in vitro assessment of drug safety and toxicity. We will employ ANOVA to understand the impact of rapalog intervention on phenotype, and their interactions, followed by adjusted post hoc t-tests. Ongoing clinical evaluation of rapalogs in patients with heritable tuberous sclerosis provides the precedent for translating our preclinical outcomes to the bedside. Pharmaceutical agents that eliminate the retinal toxicity of VGB will have enormous clinical value in epilepsy therapeutics. Such agents will also have therapeutic relevance to SSADHD, while potentially leading to novel treatment paradigms for other disorders (autism, addiction, Down syndrome) in which elevated GABA may well have pathophysiological roles, further highlighting the broad clinical impact of our proposal.