BmK NSP, a new sodium channel activator from Buthus martensii Karsch, promotes neurite outgrowth in primary cultured spinal cord neurons
BmK NSP, a new sodium channel activator from Buthus martensii Karsch, promotes neurite outgrowth in primary cultured spinal cord neurons
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BmK NSP 是一种来自 Buthus martensii Karsch 的新型钠通道激活剂，可促进原代培养的脊髓神经元中的神经突生长。
DOI：
10.1016/j.toxicon.2020.04.096
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发表时间：
2020-07-30
期刊：
影响因子：
2.8
通讯作者：
Cao, Zhengyu
中科院分区：
文献类型：
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作者：
Zou, Xiaohan;Wang, Yujing;Cao, Zhengyu
蝎子毒液是一种丰富的生物活性化合物，通过调节各种通道/受体的活动来影响神经元的兴奋性。在当前的研究中，在Ca2+动员试验的指导下，我们纯化了一种新的神经活性肽，命名为BmK NSP （Buthus martensii Karsch神经刺激肽，MW: 7064.30 Da）。通过Edman降解确定了BmK NSP的一级结构。在原代培养的脊髓神经元（SCNs）中，BmK NSP浓度依赖于细胞内Ca2+浓度（[Ca2+](i)）的升高，EC50值为4.18 μ M。细胞外Ca2+的消耗消除了BmK nsp触发的Ca2+反应。此外，我们证明BmK nsp诱导的Ca2+反应被l型Ca2+通道抑制剂、Na+-Ca2+交换剂和NMDA受体部分抑制，并被电压门控钠通道（VGSC）阻滞剂河豚毒素所消除。全细胞膜片钳记录显示，BmK NSP延缓了SCNs中VGSC的失活（EC50 = 1.10 μ M）。BmK NSP以非单调的方式促进神经突生长，其峰值与scn的30 nM相似。BmK nsp促进的神经突生长受到l型Ca2+通道、NMDA受体和VGSCs抑制剂的抑制。综上所述，这些数据表明BmK NSP是一种新的α蝎毒素，通过Ca2+内流的主要途径促进神经突生长。蝎毒素对VGSC活性的调节可能是一种调节scn神经发生的新策略。
Scorpion venom is a rich source of bioactive compounds that affect neuronal excitability by modulating the activities of various channels/receptors. In the current study, guided by a Ca2+ mobilization assay, we purified a new neuroactive peptide designated as BmK NSP (Buthus martensii Karsch neurite-stimulating peptide, MW: 7064.30 Da). The primary structure of BmK NSP was determined by Edman degradation. BmK NSP concentration-dependently elevated intracellular Ca2+ concentration ([Ca2+](i)) with an EC50 value of 4.18 mu M in primary cultured spinal cord neurons (SCNs). Depletion of extracellular Ca2+ abolished BmK NSP-triggered Ca2+ response. Moreover, we demonstrated that BmK NSP-induced Ca2+ response was partially suppressed by the inhibitors of L-type Ca2+ channels, Na+-Ca2+ exchangers and NMDA receptors and was abolished by voltage-gated sodium channel (VGSC) blocker, tetrodotoxin. Whole-cell patch clamp recording demonstrated that BmK NSP delayed VGSC inactivation (EC50 = 1.10 mu M) in SCNs. BmK NSP enhanced neurite outgrowth in a non-monotonic manner that peaked at similar to 30 nM in SCNs. BmK NSP-promoted neurite outgrowth was suppressed by the inhibitors of L-type Ca2+ channels, NMDA receptors, and VGSCs. Considered together, these data demonstrate that BmK NSP is a new alpha-scorpion toxin that enhances neurite outgrowth through main routes of Ca2+ influx. Modulation of VGSC activity by alpha-scorpion toxin might represent a novel strategy to regulate the neurogenesis in SCNs.