This proposal will develop of a potential gene therapy for Angelman syndrome (AS). The root cause of AS is the loss of the maternal copy of the gene UBE3A. In most regions of the brain, the paternal allele is intact, but is epigenetically silenced. Our goal is to activate of the silenced UBE3A allele to ameliorate the clinical manifestations of AS. We are developing zinc finger-based artificial transcription factors (ATFs) designed to activate the expression of the murine Ube3a in cultured mouse neuronal cells.
In Specific Aim 1, we will create ATFs that directly activate the transcription of murine Ube3a or repress the expression of murine Ube3a-Antisense Transcript (ATS). The milestone goal will be to create one or more ATFs that can activate Ube3a expression at least 2-fold. Several ATFs have been constructed and tested, and our preliminary data show that several are able to upregulate endogenous Ube3a protein levels.
In Specific Aim 2, the ATFs will be packaged into AAV viral vectors and delivered into the brains of AS mice. We will examine the distribution and expression of the ATF in the brain, its effect on Ube3a expression. The milestone goal is to achieve widespread neuronal transduction and expression of the ATF in injected brain structures (>10% of hippocampal cells, and transduction of some surrounding tissue). One or more ATFs are expected to cause at least a 2-fold increase in Ube3a expression from the paternal allele. Successful achievement of these milestones would justify expanded pre-clinical studies and the development of ATFs to the human UBE3A.
Angelman Syndrome (AS) is a neurogenetic disorder causing developmental delays and neurological impairments such as lack of speech. Currently, there is no cure and no specific drug therapy. Activation of the silenced paternal UBE3A allele by an ATF could address the fundamental genetic deficiency causing AS, and thus be a potentially curative gene therapy. This proposal will investigate such a therapy in a mouse model.
|Bailus, Barbara J; Pyles, Benjamin; McAlister, Michelle M et al. (2016) Protein Delivery of an Artificial Transcription Factor Restores Widespread Ube3a Expression in an Angelman Syndrome Mouse Brain. Mol Ther 24:548-55|
|Bailus, Barbara J; Segal, David J (2014) The prospect of molecular therapy for Angelman syndrome and other monogenic neurologic disorders. BMC Neurosci 15:76|