A型肉毒素对带状疱疹后神经痛小鼠炎性神经递质表达的影响

The effect of botulinum toxin A on the expression of inflammatory neurotransmitters in mice with postherpetic neuralgia

目的:观察A型肉毒素(BTX-A)对带状疱疹后神经痛(PHN)小鼠炎性神经递质表达的影响,探讨其可能的作用机制。方法:将36只PHN雄性C57小鼠随机分成A、B、C 3组,每组12只。A组在疱疹部位注射0.9%氯化钠溶液;B组在疱疹部位注射BTX-A(2 U/kg);C组在L5背根神经节(DRG)处注射BTX-A(2 U/kg)。连续干预7 d后处死小鼠,取小鼠DRG和相应的脊髓节段,采用RT-q PCR和ELISA法检测各组小鼠DRG和脊髓中炎性神经递质TNF-α、IL-1β、神经激肽A的m RNA表达,采用Western blot检测各组小鼠DRG和脊髓中Na1.3、Na1.8通道蛋白表达。结果:RT-q PCR检测结果显示,与A组比,B组和C组炎性神经递质TNF-α、IL-1β、神经激肽A的m RNA表达水平显著降低(P<0.05),但B和C 2组间比较差异无统计学意义。ELISA法检测结果显示,与A组比,B组和C组TNF-α、IL-1β、神经激肽A的蛋白含量显著降低(P<0.05),但B和C 2组间比较差异无统计学意义。Western blot结果显示,与A组比,B组和C组Na1.3、Na1.8通道蛋白表达显著降低(P<0.05),但B和C 2组间比较差异无统计学意义。结论:BTX-A能有效抑制PHN,其作用机制可能是通过降低通道蛋白Na1.3、Na1.8的表达,抑制炎性神经递质TNF-α、IL-1β、神经激肽A的mRNA表达水平和蛋白含量。

Objective: To explore the mechanism of botulinum toxin A(BTX-A) on postherpetic neuralgia(PHN) by observing its effect on the expression of inflammatory neurotransmitter in mice with PNH. Methods: Thirty-six male C57 mice with PHN were randomly divided as group A, B and C, with 12 mice in each group. Herpes site in group A was injected with 0.9% saline, with BTX-A(2 U/kg) in group B, while BTX-A(2 U/kg) was injected into dorsal root ganglion(DRG) of the fifth lumber spine in group C. All mice were sacrificed after 7 d of continuous intervention, and DRG and corresponding segments of spinal cord were isolated from mice. The mRNA expression levels of TNF-α, IL-1β and neurokinin A in DRG and spinal cord was detected by RT-qPCR and ELISA. The expression of Na1.3 and Na1.8 channels in DRG and spinal cord was detected by Western blot. Results: RT-q PCR results showed that the mRNA expression levels of inflammatory neurotransmitters on TNF-α, IL-1β and neurokinin A in group B and group C were significantly lower than those in group A(P<0.05), but there was no significant difference between group B and group C. The results of ELISA showed that the protein contents of TNF-α, IL-1β and neurokinin A in group B and group C were significantly lower than those in group A(P<0.05), but there was no significant difference between group B and group C. Western blot results showed that the expression of Na1.3 and Na1.8 channel proteins in group B and group C decreased significantly compared with group A(P<0.05), but there was no statistical difference between the two groups. Conclusion: BTXA can effectively inhibit PHN, and its mechanism may be by reducing the expression of Na1.3 and Na1.8 channel proteins and thus inhibiting the expression of inflammatory neurotransmitters TNF-α, IL-1β and neurokinin A.