Affiliated Stomatological Hospital of Nanchang University, Nanchang, Jiangxi, China.
First Affiliated Hospital of Nanchang University, Nanchang, Jiangxi, China.
Sci Rep. 2020 Mar 19;10(1):4998. doi: 10.1038/s41598-020-61969-1.
Trigeminal neuralgia (TN), a sudden, needle-like pain in the distribution area of the trigeminal nerve, can seriously affect the physical and mental health of patients. In chronic pain conditions including TN, increased levels of brain-derived neurotrophic factor (BDNF) may enhance pain transmission. This study compares the effect of palmatine administration on the expression of BDNF and its receptor TrkB (tropomyosin receptor kinase B) in trigeminal ganglion cells of Sprague-Dawley rats in a sham versus TN model group. Within 14 days of surgery, the mechanical allodynia threshold of the TN group was significantly lower than that of the sham group, while the TN + palmatine group had a higher mechanical pain sensitivity threshold than the TN group (p < 0.05). Real-time quantitative PCR, immunohistochemistry, and immunofluorescence showed that BDNF and TrkB expression in the TN group was higher than that in the sham group, while palmatine treatment could reverse these changes. Western blotting showed that palmatine treatment could reduce the elevated phosphorylation of extracellular signal-regulated kinases 1/2 (ERK1/2) in TN rats. Thus, the BDNF/TrkB pathway may be involved in the pain transmission process of TN, and palmatine treatment may reduce pain transmission by inhibiting the BDNF/TrkB pathway and suppressing ERK1/2 phosphorylation.
三叉神经痛（TN）是一种发生在三叉神经分布区域的突发针刺样疼痛，可严重影响患者的身心健康。在包括 TN 在内的慢性疼痛情况下，脑源性神经营养因子（BDNF）水平的增加可能会增强疼痛的传递。本研究比较了黄连碱给药对假手术与 TN 模型组 Sprague-Dawley 大鼠三叉神经节细胞中 BDNF 及其受体 TrkB（原肌球蛋白受体激酶 B）表达的影响。在手术 14 天内，TN 组的机械性痛觉过敏阈值明显低于假手术组，而 TN+黄连碱组的机械性疼痛敏感性阈值高于 TN 组（p<0.05）。实时定量 PCR、免疫组织化学和免疫荧光显示，TN 组的 BDNF 和 TrkB 表达高于假手术组，而黄连碱治疗可以逆转这些变化。Western blot 显示，黄连碱治疗可降低 TN 大鼠中细胞外信号调节激酶 1/2（ERK1/2）的磷酸化水平升高。因此，BDNF/TrkB 通路可能参与 TN 的疼痛传递过程，黄连碱治疗可能通过抑制 BDNF/TrkB 通路和抑制 ERK1/2 磷酸化来减轻疼痛传递。
