Department of Neurology, UTHSC, Memphis, TN, United States of America; Integrated Biomedical Science Program, UTHSC, Memphis, TN, United States of America.
Molecular Bioinformatics Core, UTHSC, Memphis, TN, United States of America.
Neurobiol Dis. 2020 Jul;141:104879. doi: 10.1016/j.nbd.2020.104879. Epub 2020 Apr 25.
Epilepsy affects millions of individuals worldwide and many cases are pharmacoresistant. Duplication 15q syndrome (Dup15q) is a genetic disorder caused by duplications of the 15q11.2-q13.1 region. Phenotypes include a high rate of pharmacoresistant epilepsy. We developed a Dup15q model in Drosophila melanogaster that recapitulates seizures in Dup15q by over-expressing fly Dube3a or human UBE3A in glial cells, but not neurons, implicating glia in the Dup15q epilepsy phenotype. We compared Dube3a overexpression in glia (repo>Dube3a) versus neurons (elav>Dube3a) using transcriptomics and proteomics of whole fly head extracts. We identified 851 transcripts differentially regulated in repo>Dube3a, including an upregulation of glutathione S-transferase (GST) genes that occurred cell autonomously within glial cells. We reliably measured approximately 2,500 proteins by proteomics, most of which were also quantified at the transcript level. Combined transcriptomic and proteomic analysis revealed an enrichment of 21 synaptic transmission genes downregulated at the transcript and protein in repo>Dube3a indicating synaptic proteins change in a cell non-autonomous manner in repo>Dube3a flies. We identified 6 additional glia originating bang-sensitive seizure lines and found upregulation of GSTs in 4 out of these 6 lines. These data suggest GST upregulation is common among gliopathic seizures and may ultimately provide insight for treating epilepsy.
癫痫影响着全球数以百万计的个体，许多病例对药物治疗具有抗性。15q 重复综合征（Dup15q）是一种由 15q11.2-q13.1 区域重复引起的遗传疾病。其表型包括高比例的药物难治性癫痫。我们在果蝇中建立了 Dup15q 模型，通过在神经胶质细胞中过度表达果蝇 Dube3a 或人类 UBE3A 来重现 Dup15q 的癫痫发作，但不是神经元，这表明胶质细胞在 Dup15q 癫痫表型中起作用。我们比较了胶质细胞中 Dube3a 的过表达（repo>Dube3a）与神经元中 Dube3a 的过表达（elav>Dube3a），方法是使用全果蝇头部提取物的转录组学和蛋白质组学。我们鉴定了 851 个在 repo>Dube3a 中差异调节的转录本，包括谷胱甘肽 S-转移酶（GST）基因的上调，这种上调在胶质细胞中具有细胞自主性。我们通过蛋白质组学可靠地测量了大约 2500 种蛋白质，其中大多数在转录水平上也进行了定量。综合转录组学和蛋白质组学分析显示，在 repo>Dube3a 中，21 个突触传递基因的转录和蛋白质水平下调，表明突触蛋白以非细胞自主性的方式在 repo>Dube3a 果蝇中发生变化。我们鉴定了另外 6 条胶质起源的 bang 敏感癫痫发作系，发现其中 4 条系中的 GSTs 上调。这些数据表明 GST 的上调在神经胶质病变性癫痫发作中很常见，最终可能为治疗癫痫提供线索。
