The natural scorpion peptide, BmK NT1 activates voltage-gated sodium channels and produces neurotoxicity in primary cultured cerebellar granule cells
The natural scorpion peptide, BmK NT1 activates voltage-gated sodium channels and produces neurotoxicity in primary cultured cerebellar granule cells
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天然蝎肽 BmK NT1 激活电压门控钠通道并在原代培养的小脑颗粒细胞中产生神经毒性
DOI：
10.1016/j.toxicon.2015.11.005
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发表时间：
2016
期刊：
影响因子：
2.8
通讯作者：
Zhengyu Cao
中科院分区：
文献类型：
--
作者：
Xiaohan Zou;Yuwei He;Jinping Qiao;Chunlei Zhang;Zhengyu Cao
东亚钳蝎（Buthus martensii Karsch）在中国传统医学中用于治疗神经疾病，如神经性疼痛，瘫痪和癫痫已有数千年的历史。研究表明蝎毒是其主要活性成分。蝎毒在临床上虽能有效镇痛，但也产生神经毒性反应。在本研究中，毒性指导纯化导致鉴定了一种称为BmK NT 1的哺乳动物毒素，其包含65个氨基酸残基和酰胺化C-末端，其是由核苷酸序列（GenBank No.AF464898）编码的成熟肽。与具有相同核苷酸序列的重组产物BmK AGAP相比，静脉注射（i. v.）BmK NT 1对小鼠产生急性毒性，LD_（50）为1.36 mg/kg。在原代培养的小脑颗粒细胞中，BmK NT 1产生浓度依赖性细胞死亡，IC 50值为0.65 mM（0.41 e1.03 mM，95%置信区间，95% CI），可被电压门控钠通道（VGSC）阻断剂TTX消除。我们还证明，BmK NT 1产生适度的钠流入小脑颗粒细胞培养物中的EC 50值为2.19 mM（0.76e6.40 mM，95% CI），类似于VGSC激动剂，藜芦碱的效果。钠内流反应被TTX消除，表明BmK NT 1诱导的钠内流仅通过激活VGSC。综合考虑这些数据，我们证明了BmK NT 1激活VGSC并在小脑颗粒细胞培养中产生神经毒性。
The scorpion Buthus martensii Karsch has been used in Traditional Chinese Medicine to treat neuronal diseases such as neuropathic pain, paralysis and epilepsy for thousands of years. Studies have demon- strated that scorpion venom is the primary active component. Although scorpion venom can effectively attenuate pain in the clinic, it also produces neurotoxic response. In this study, toxicity guided purifi- cation led to identify a mammalian toxin termed BmK NT1 comprising of 65 amino acid residues and an amidated C-terminus, a mature peptide encoded by the nucleotide sequence (GenBank No. AF464898). In contract to the recombinant product of the same nucleotide sequence, BmK AGAP, which displayed analgesic and anti-tumor effect, intravenous injection (i.v.) of BmK NT1 produced acute toxicity in mice with an LD50 value of 1.36 mg/kg. In primary cultured cerebellar granule cells, BmK NT1 produced a concentration-dependent cell death with an IC50 value of 0.65 mM (0.41e1.03 mM, 95% Confidence In- tervals, 95% CI) which was abolished by TTX, a voltage-gated sodium channel (VGSC) blocker. We also demonstrated that BmK NT1 produced modest sodium influx in cerebellar granule cell cultures with an EC50 value of 2.19 mM (0.76e6.40 mM, 95% CI), an effect similar to VGSC agonist, veratridine. The sodium influx response was abolished by TTX suggesting that BmK NT1-induced sodium influx is solely through activation of VGSC. Considered these data together, we demonstrated that BmK NT1 activated VGSC and produced neurotoxicity in cerebellar granule cell cultures.