Department of Anesthesiology, Duke University Medical Center, 595 LaSalle St, Durham, NC, 27710, USA.
Department of Biochemistry, Duke University Medical Center, 303 Research Drive, Durham, NC, 27710, USA.
Neurosci Bull. 2018 Feb;34(1):22-41. doi: 10.1007/s12264-018-0203-0. Epub 2018 Jan 15.
The voltage-gated Na channel subtype Nav1.7 is important for pain and itch in rodents and humans. We previously showed that a Nav1.7-targeting monoclonal antibody (SVmab) reduces Na currents and pain and itch responses in mice. Here, we investigated whether recombinant SVmab (rSVmab) binds to and blocks Nav1.7 similar to SVmab. ELISA tests revealed that SVmab was capable of binding to Nav1.7-expressing HEK293 cells, mouse DRG neurons, human nerve tissue, and the voltage-sensor domain II of Nav1.7. In contrast, rSVmab showed no or weak binding to Nav1.7 in these tests. Patch-clamp recordings showed that SVmab, but not rSVmab, markedly inhibited Na currents in Nav1.7-expressing HEK293 cells. Notably, electrical field stimulation increased the blocking activity of SVmab and rSVmab in Nav1.7-expressing HEK293 cells. SVmab was more effective than rSVmab in inhibiting paclitaxel-induced mechanical allodynia. SVmab also bound to human DRG neurons and inhibited their Na currents. Finally, potential reasons for the differential efficacy of SVmab and rSVmab and future directions are discussed.
电压门控钠离子通道亚型 Nav1.7 对啮齿动物和人类的疼痛和瘙痒很重要。我们之前的研究表明，一种靶向 Nav1.7 的单克隆抗体 (SVmab) 可减少小鼠的钠离子电流和疼痛及瘙痒反应。在此，我们研究了重组 SVmab(rSVmab) 是否与 SVmab 具有相似的结合和阻断 Nav1.7 的能力。ELISA 检测表明，SVmab 能够与表达 Nav1.7 的 HEK293 细胞、小鼠背根神经节神经元、人神经组织和 Nav1.7 的电压传感器结构域 II 结合。相比之下，rSVmab 在这些测试中几乎不能与 Nav1.7 结合。膜片钳记录显示，SVmab 但不是 rSVmab ，可显著抑制表达 Nav1.7 的 HEK293 细胞中的钠离子电流。值得注意的是，电场刺激增加了 SVmab 和 rSVmab 在表达 Nav1.7 的 HEK293 细胞中的阻断活性。SVmab 在抑制紫杉醇诱导的机械性痛觉过敏方面比 rSVmab 更有效。SVmab 还与人类背根神经节神经元结合，并抑制其钠离子电流。最后，讨论了 SVmab 和 rSVmab 效力差异的潜在原因和未来的研究方向。
