Bailus Barbara J, Pyles Benjamin, McAlister Michelle M, O'Geen Henriette, Lockwood Sarah H, Adams Alexa N, Nguyen Jennifer Trang T, Yu Abigail, Berman Robert F, Segal David J
Genome Center, MIND Institute, and Department of Biochemistry and Molecular Medicine, University of California, Davis, California, USA.
Department of Neurological Surgery, University of California, Davis, California, USA.
Mol Ther. 2016 Mar;24(3):548-55. doi: 10.1038/mt.2015.236. Epub 2016 Jan 4.
Angelman syndrome (AS) is a neurological genetic disorder caused by loss of expression of the maternal copy of UBE3A in the brain. Due to brain-specific genetic imprinting at this locus, the paternal UBE3A is silenced by a long antisense transcript. Inhibition of the antisense transcript could lead to unsilencing of paternal UBE3A, thus providing a therapeutic approach for AS. However, widespread delivery of gene regulators to the brain remains challenging. Here, we report an engineered zinc finger-based artificial transcription factor (ATF) that, when injected i.p. or s.c., crossed the blood-brain barrier and increased Ube3a expression in the brain of an adult mouse model of AS. The factor displayed widespread distribution throughout the brain. Immunohistochemistry of both the hippocampus and cerebellum revealed an increase in Ube3a upon treatment. An ATF containing an alternative DNA-binding domain did not activate Ube3a. We believe this to be the first report of an injectable engineered zinc finger protein that can cause widespread activation of an endogenous gene in the brain. These observations have important implications for the study and treatment of AS and other neurological disorders.
天使综合征（AS）是一种神经遗传性疾病，由大脑中母本UBE3A基因拷贝的表达缺失引起。由于该基因座存在脑特异性基因印记，父本UBE3A被一个长反义转录本沉默。抑制该反义转录本可导致父本UBE3A去沉默，从而为AS提供一种治疗方法。然而，将基因调控因子广泛递送至大脑仍然具有挑战性。在此，我们报道了一种基于锌指的工程化人工转录因子（ATF），当通过腹腔注射或皮下注射时，其能够穿过血脑屏障并增加成年AS小鼠模型大脑中Ube3a的表达。该因子在整个大脑中广泛分布。海马体和小脑的免疫组织化学显示，治疗后Ube3a表达增加。含有替代DNA结合结构域的ATF不能激活Ube3a。我们认为这是关于一种可注射的工程化锌指蛋白能够在大脑中广泛激活内源性基因的首次报道。这些发现对AS及其他神经疾病的研究和治疗具有重要意义。
