Deficiency of the Housekeeping Gene Hypoxanthine-Guanine Phosphoribosyltransferase (HPRT) Dysregulates Neurogenesis
Deficiency of the Housekeeping Gene Hypoxanthine-Guanine Phosphoribosyltransferase (HPRT) Dysregulates Neurogenesis
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DOI：
10.1038/mt.2009.178
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发表时间：
2010-01-01
影响因子：
12.4
通讯作者：
Friedmann, Theodore
中科院分区：
文献类型：
--
作者：
Guibinga, Ghiabe-Henri;Hsu, Stephen;Friedmann, Theodore
神经元转录因子在神经元（包括多巴胺能（DA）神经元）的规范和发育中发挥着至关重要的作用。编码嘌呤生物合成酶次黄嘌呤鸟嘌呤磷酸核糖基转移酶 (HPRT) 的基因突变会导致 Lesch-Nyhan 病 (LND) 的棘手且基本上无法治疗的神经损伤。该疾病与基底神经节 DA 通路缺陷有关。人们对嘌呤代谢缺陷和中枢神经系统 (CNS) 表型之间的联系机制知之甚少，但据推测反映了 DA 神经元的发育缺陷。我们在成熟的人类 (NT2) 胚胎癌神经发生模型中研究了 HPRT 缺陷对神经元分化的影响。我们使用表达小发夹 RNA (shRNA) 的逆转录病毒来敲低 HPRT 基因表达，并检查了许多神经元分化必需的转录因子和参与 DA 生物合成途径的标记基因的表达。 HPRT 缺陷的 NT2 细胞表现出多种转录因子和 DA 标记的异常表达。尽管分化的 HPRT 缺陷神经元在分化过程中也表现出神经突生长的显着缺陷，但所得神经元表现出野生型电生理特性。这些结果代表了 HPRT 缺陷中神经发生异常的直接实验证据，并表明其他管家基因在神经发育疾病中的发育作用。
Neuronal transcription factors play vital roles in the specification and development of neurons, including dopaminergic (DA) neurons. Mutations in the gene encoding the purine biosynthetic enzyme-hypoxanthine-guanine phosphoribosyltransferase (HPRT) cause the resulting intractable and largely untreatable neurological impairment of Lesch-Nyhan disease (LND). The disorder is associated with a defect in basal ganglia DA pathways. The mechanisms connecting the purine metabolic defect and the central nervous system (CNS) phenotype are poorly understood but have been presumed to reflect a developmental defect of DA neurons. We have examined the effect of HPRT deficiency on the differentiation of neurons in the well-established human (NT2) embryonic carcinoma neurogenesis model. We have used a retrovirus expressing a small hairpin RNA (shRNA) to knock down HPRT gene expression and have examined the expression of a number of transcription factors essential for neuronal differentiation and marker genes involved in DA biosynthetic pathway. HPRT-deficient NT2 cells demonstrate aberrant expression of several transcription factors and DA markers. Although differentiated HPRTdeficient neurons also demonstrate a striking deficit in neurite outgrowth during differentiation, resulting neurons demonstrate wild-type electrophysiological properties. These results represent direct experimental evidence for aberrant neurogenesis in HPRT deficiency and suggest developmental roles for other housekeeping genes in neurodevelopmental disease.