Development of Molecular Therapy for Carbamoyl Phosphate Synthetase Deficiency

 描述：尿素循环是哺乳动物氨解毒的主要途径。氨甲酰磷酸合成酶1（CPS 1）缺乏是一种毁灭性的疾病。在人类中，这种酶缺乏的临床特征是高氨血症的周期性发作，导致进行性精神损害和死亡的可能性很高。该提案旨在描述一种新的疾病动物模型，并开发用病毒载体进行基于基因的氨甲酰磷酸合成酶缺陷校正的方法。初步数据：我们的研究小组有：1）一直在开发条件性CPS 1缺陷敲除小鼠;和2）在患有导致遗传校正的肝细胞内和分泌蛋白质紊乱（血友病A和腺苷酸酶缺陷）的动物中，在新生儿给药后，证明了来自重组辅助依赖性腺病毒载体和腺相关病毒载体的转基因的短期和长期表达。在目标1中，我们将描述一种新的条件性敲除小鼠模型的氨甲酰磷酸合成酶I缺乏症，这将有助于开发这种疾病的治疗方法;在目标2中，我们将开发新的基因治疗载体作为CPS 1缺乏症的基因替代策略。这些研究将提供重要的新工具，开发方法的基因校正的CPS 1缺乏症，并提供一个小动物模型，研究脑损伤的机制超出了近端尿素循环障碍的高氨血症。

 DESCRIPTION: The urea cycle is the major pathway for detoxification of ammonia in mammals. Carbamoyl phosphate synthetase 1 (CPS1) deficiency is a devastating condition. In humans, deficiency of this enzyme is characterized clinically by periodic episodes of hyperammonemia resulting in progressive mental impairment and a high likelihood of death. This proposal is to characterize a new animal model of the disorder and develop methods for gene-based correction of carbamoyl phosphate synthetase deficiency with viral vectors. Preliminary data: Our research group has: 1) been developing a conditional CPS1-deficient knockout mouse; and 2) demonstrated short-term and long-term expression of transgenes from both recombinant helper-dependent adenoviral vectors and adeno-associated viral vectors after neonatal administration in animals with disorders of intracellular and secreted proteins of the liver resulting in genetic correction (hemophilia A and arginase deficiency). In Aim 1, we will characterize a novel conditional knockout mouse model of carbamoyl phosphate synthetase I deficiency that will be useful for developing therapies for this disorder; and in Aim 2, we will develop novel gene therapy vectors as gene replacement strategies for CPS1 deficiency. These studies will provide important new tools to develop methods for gene correction of CPS1 deficiency and provide a small animal model to study the mechanism of brain injury beyond that of hyperammonemia in proximal urea cycle disorders.