Glutamate-dependent ectodomain shedding of neuregulin-1 type II precursors in rat forebrain neurons.
Glutamate-dependent ectodomain shedding of neuregulin-1 type II precursors in rat forebrain neurons.
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DOI：
10.1371/journal.pone.0174780
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发表时间：
2017
期刊：
影响因子：
3.7
通讯作者：
Nawa H
中科院分区：
文献类型：
--
作者：
Iwakura Y;Wang R;Inamura N;Araki K;Higashiyama S;Takei N;Nawa H
神经营养因子神经调节蛋白1（NRG 1）调节神经元发育、神经胶质分化和兴奋性突触成熟。NRG 1作为膜锚定前体合成，然后通过蛋白水解加工或胞吐作用释放。然后成熟的NRG 1与邻近神经元或神经胶质细胞表达的受体结合。然而，控制神经系统中这一过程的分子机制尚未详细定义。在这里，我们准备了神经元富集和胶质细胞富集的培养物从胚胎大鼠新皮层神经递质的作用，调节释放/释放NRG 1的神经元或神经胶质细胞的膜。使用双位点酶免疫检测可溶性NRG 1，我们表明，各种神经递质，谷氨酸是最有效的诱导剂NRG 1释放神经元富集的文化。神经胶质细胞富集培养物中NRG 1的释放相对有限。此外，在谷氨酸受体激动剂中，N-甲基-D-天冬氨酸（NMDA）和红藻氨酸（KA），而不是AMPA或tACPD，模拟谷氨酸的作用。从KA诱导癫痫发作的大鼠海马的分析中获得了类似的结果。为了评估的解整合素和金属蛋白酶（ADAM）家族的成员NRG 1释放的贡献，我们转染的原代培养的神经元与cDNA载体编码NRG 1型I，II，或III的前体，每个标记的碱性磷酸酶报告。碱性磷酸酶活性分析显示，NRG 1 II型前体以蛋白激酶C依赖性方式经历肿瘤坏死因子-α-转化酶（TACE）/ a去整合素和金属蛋白酶17（ADAM 17）依赖性胞外域脱落。这些结果表明，多巴胺能神经传递积极调节NRG 1 II型前体的胞外结构域脱落，并以活性依赖的方式释放活性NRG 1结构域。
The neurotrophic factor neuregulin 1 (NRG1) regulates neuronal development, glial differentiation, and excitatory synapse maturation. NRG1 is synthesized as a membrane-anchored precursor and is then liberated by proteolytic processing or exocytosis. Mature NRG1 then binds to its receptors expressed by neighboring neurons or glial cells. However, the molecular mechanisms that govern this process in the nervous system are not defined in detail. Here we prepared neuron-enriched and glia-enriched cultures from embryonic rat neocortex to investigate the role of neurotransmitters that regulate the liberation/release of NRG1 from the membrane of neurons or glial cells. Using a two-site enzyme immunoassay to detect soluble NRG1, we show that, of various neurotransmitters, glutamate was the most potent inducer of NRG1 release in neuron-enriched cultures. NRG1 release in glia-enriched cultures was relatively limited. Furthermore, among glutamate receptor agonists, N-Methyl-D-Aspartate (NMDA) and kainate (KA), but not AMPA or tACPD, mimicked the effects of glutamate. Similar findings were acquired from analysis of the hippocampus of rats with KA-induced seizures. To evaluate the contribution of members of a disintegrin and metalloproteinase (ADAM) families to NRG1 release, we transfected primary cultures of neurons with cDNA vectors encoding NRG1 types I, II, or III precursors, each tagged with the alkaline phosphatase reporter. Analysis of alkaline phosphatase activity revealed that the NRG1 type II precursor was subjected to tumor necrosis factor-α-converting enzyme (TACE) / a Disintegrin And Metalloproteinase 17 (ADAM17) -dependent ectodomain shedding in a protein kinase C-dependent manner. These results suggest that glutamatergic neurotransmission positively regulates the ectodomain shedding of NRG1 type II precursors and liberates the active NRG1 domain in an activity-dependent manner.