免疫调节剂黄芪甲苷通过调节 K-JNK 缝隙连接信号通路减轻神经病理性疼痛。
Regulation of the K-JNK gap junction signaling pathway by immunomodulator astragaloside IV attenuates neuropathic pain.
机构信息
Jiangsu Key Laboratory of TCM Evaluation and Translational Research, School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing, Jiangsu, China.
Department of Anesthesiology, Children's Hospital of Nanjing Medical University, Nanjing, Jiangsu, China.
出版信息
Reg Anesth Pain Med. 2020 Dec;45(12):955-963. doi: 10.1136/rapm-2020-101411. Epub 2020 Sep 22.
BACKGROUND AND OBJECTIVES
Gap junctions play a pivotal role in contributing to the formation of astroglial networks and in chronic pain. However, the mechanisms underlying the dysfunction of astroglial gap junctions in chronic pain have not been fully elucidated.
METHODS
Chronic constriction injury (CCI) of the sciatic nerve was used to establish rat neuropathic pain model. C6 cells were used to perform experiments in vitro. Von Frey hairs and Hargreave's method were used to determine the withdrawal threshold of rats. Protein expression was detected by immunofluorescence and western blotting.
RESULTS
Astragaloside IV (AST IV) significantly attenuated neuropathic pain and suppressed the excitation of spinal astrocytes in rats with CCI. The antinociceptive effect of AST IV was reversed by the gap junction decoupler carbenoxolone (CBX). AST IV inhibited the high expression of phosphorylated connexin 43 (p-Cx43) and p-c-Jun N-terminal kinase (p-JNK) in spinal cord of rats with CCI. JNK inhibitor alleviated neuropathic pain, which was reversed by CBX. JNK inhibitor decreased the high expression of p-Cx43 in both rats with CCI and tumor necrosis factor-alpha (TNF-α)-treated C6 cells. Additionally, the analgesic effect of AST IV was reversed by the adenosine triphosphate-sensitive potassium (K) channel blocker, glibenclamide (Glib). Glib abolished the inhibitory effects of AST IV on p-JNK and p-Cx43 both in vivo and in vitro. K channel opener (KCO) mimicked the inhibitory effects of AST IV on p-JNK and p-Cx43 in TNF-α-treated C6 cells.
CONCLUSION
Our results indicate that the sciatic nerve CCI induces the dysfunction of gap junctions in the spinal cord by activating K/JNK signaling to contribute to neuropathic pain. AST IV attenuates neuropathic pain via regulating the K-JNK gap junction axis.
背景与目的
缝隙连接在星形胶质细胞网络的形成和慢性疼痛中发挥着关键作用。然而，星形胶质细胞缝隙连接在慢性疼痛中的功能障碍的机制尚未完全阐明。
方法
采用坐骨神经慢性缩窄性损伤（CCI）建立大鼠神经病理性疼痛模型。体外实验采用 C6 细胞。用 Von Frey 毛发和 Hargreave 法测定大鼠的退缩阈值。免疫荧光和 Western blot 检测蛋白表达。
结果
黄芪甲苷（AST IV）显著减轻 CCI 大鼠的神经病理性疼痛，并抑制脊髓星形胶质细胞的兴奋。缝隙连接解偶联剂 carbenoxolone（CBX）逆转了 AST IV 的镇痛作用。AST IV 抑制 CCI 大鼠脊髓中磷酸化连接蛋白 43（p-Cx43）和 c-Jun N 端激酶（p-JNK）的高表达。JNK 抑制剂减轻了神经病理性疼痛，而 CBX 则逆转了这一作用。JNK 抑制剂降低了 CCI 大鼠和 TNF-α 处理的 C6 细胞中 p-Cx43 的高表达。此外，三磷酸腺苷敏感性钾（K）通道阻滞剂格列本脲（Glib）逆转了 AST IV 的镇痛作用。Glib 消除了 AST IV 在体内和体外对 p-JNK 和 p-Cx43 的抑制作用。K 通道开放剂（KCO）模拟了 AST IV 在 TNF-α 处理的 C6 细胞中对 p-JNK 和 p-Cx43 的抑制作用。
结论
我们的结果表明，CCI 坐骨神经通过激活 K/JNK 信号通路导致脊髓缝隙连接功能障碍，从而导致神经病理性疼痛。AST IV 通过调节 K-JNK 缝隙连接轴减轻神经病理性疼痛。
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