Departamento de Farmacobiología, Cinvestav, Mexico City, Mexico.
Unidad de Investigación Médica en Inmunología e Infectología, Centro Médico Nacional, La Raza, IMSS. Mexico City, Mexico.
J Pain. 2023 Apr;24(4):689-705. doi: 10.1016/j.jpain.2022.12.005. Epub 2022 Dec 13.
Previous studies have reported that L5/L6 spinal nerve ligation (SNL), but not L5 spinal nerve transection (SNT), enhances anoctamin-1 in injured and uninjured dorsal root ganglia (DRG) of rats suggesting some differences in function of the type of nerve injury. The role of bestrophin-1 in these conditions is unknown. The aim of this study was to investigate the role of bestrophin-1 in rats subjected to L5 SNT and L5/L6 SNL. SNT up-regulated bestrophin-1 protein expression in injured L5 and uninjured L4 DRG at day 7, whereas it enhanced GAP43 mainly in injured, but also in uninjured DRG. In contrast, SNL enhanced GAP43 at day 1 and 7, while bestrophin-1 expression increased only at day 1 after nerve injury. Accordingly, intrathecal injection of the bestrophin-1 blocker CaCC (1-10 µg) reverted SNT- or SNL-induced tactile allodynia in a concentration-dependent manner. Intrathecal injection of CaCC (10 µg) prevented SNT-induced upregulation of bestrophin-1 and GAP43 at day 7. In contrast, CaCC did not affect SNL-induced up-regulation of GAP43 nor bestrophin-1. Bestrophin-1 was mainly expressed in small- and medium-size neurons in naïve rats, while SNT increased bestrophin-1 immunoreactivity in CGRP+, but not in IB4+ neuronal cells in DRG. Intrathecal injection of bestrophin-1 plasmid (pCMVBest) induced tactile allodynia and increased bestrophin-1 expression in DRG and spinal cord in naïve rats. CaCC reversed bestrophin-1 overexpression-induced tactile allodynia and restored bestrophin-1 expression. Our data suggest that bestrophin-1 plays a relevant role in neuropathic pain induced by SNT, but not by SNL. PERSPECTIVE: SNT, but not SNL, up-regulates bestrophin-1 and GAP43 protein expression in injured L5 and uninjured L4 DRG. SNT increases bestrophin-1 immunoreactivity in CGRP+ neurons in DRG. Bestrophin-1 overexpression induces allodynia. CaCCinh-A01 reduces allodynia and restores bestrophin-1 expression. Our data suggest bestrophin-1 is differentially regulated depending on the neuropathic pain model.
先前的研究表明，L5/L6 脊神经结扎（SNL）而非 L5 脊神经切断术（SNT）增强了损伤和未损伤的背根神经节（DRG）中的 anoctamin-1，表明两种神经损伤的功能存在一些差异。但是，目前尚不清楚 bestrophin-1 在这些情况下的作用。本研究旨在探讨 SNT 和 L5/L6 SNL 后大鼠中 bestrophin-1 的作用。SNT 在第 7 天上调了受伤的 L5 和未受伤的 L4 DRG 中的 bestrophin-1 蛋白表达，而 GAP43 主要在受伤的 DRG 中增强，也在未受伤的 DRG 中增强。相比之下，SNL 在第 1 天和第 7 天增强了 GAP43，而 bestrophin-1 表达仅在神经损伤后第 1 天增加。因此，鞘内注射 bestrophin-1 阻断剂 CaCC（1-10μg）以浓度依赖性方式逆转 SNT 或 SNL 引起的触觉过敏。鞘内注射 CaCC（10μg）可预防 SNT 诱导的第 7 天 bestrophin-1 和 GAP43 的上调。相比之下，CaCC 不会影响 SNL 诱导的 GAP43 或 bestrophin-1 的上调。在未受伤的大鼠中，bestrophin-1 主要表达于中小神经元中，而 SNT 增加了 CGRP+神经元，而不是 DRG 中的 IB4+神经元中的 bestrophin-1 免疫反应性。鞘内注射 bestrophin-1 质粒（pCMVBest）可引起感觉过敏，并增加了未受伤的大鼠的 DRG 和脊髓中的 bestrophin-1 表达。CaCC 逆转了 bestrophin-1 过表达诱导的触觉过敏，并恢复了 bestrophin-1 的表达。我们的数据表明，bestrophin-1 在 SNT 引起的神经性疼痛中起重要作用，但在 SNL 中不起作用。观点：SNT 而非 SNL 会上调受伤的 L5 和未受伤的 L4 DRG 中的 bestrophin-1 和 GAP43 蛋白表达。SNT 增加了 DRG 中 CGRP+神经元中的 bestrophin-1 免疫反应性。Bestrophin-1 过表达可引起痛觉过敏。CaCCinh-A01 减轻痛觉过敏并恢复 bestrophin-1 的表达。我们的数据表明，bestrophin-1 的表达取决于神经性疼痛模型。
