老年小鼠慢性痛焦虑模型肠道菌群的变化规律

Changes of gut microbiota in aged mice with chronic neuropathic pain-related anxiety

目的观察老年慢性神经病理性痛伴焦虑小鼠的焦虑样行为和肠道菌群的变化规律。方法将16月龄的雄性C57BL/6小鼠随机分为模型组和对照组,每组6只。对模型组小鼠进行坐骨神经选择性结扎切断(spared nerve injury,SNI)手术。在手术后第21天,应用Von-Frey丝检测小鼠的机械痛敏,应用旷场实验(open field test,OFT)和高架十字实验(elevated plus maze,EPM)检测小鼠焦虑行为的变化,应用16S rDNA测序检测小鼠肠道菌群变化。结果与对照组相比,SNI小鼠痛敏阈值显著降低(P<0.001)。SNI术后第21天,SNI小鼠进入OFT的中央区和EPM的开臂区的活动时间比对照组明显减少(P<0.05),但活动总路程没有发生明显变化,提示SNI小鼠出现焦虑样行为。SNI小鼠肠道菌群结构紊乱及菌群多样性降低,在门分类水平,2β-变形菌显著减少;在目分类水平,乳杆菌显著减少;在科分类水平,普雷沃氏菌显著减少。结论老年慢性痛小鼠具有焦虑样的行为,且肠道菌群发生明显变化。

Objective To observe the anxiety-like behavior and the change of gut microbiota in aged mice with chronic neuropathic pain-related anxiety.Methods The male C57 BL/6 mice aged 16 months were randomly divided into model group and control group,with 6 mice in each group.Spared nerve injury(SNI)surgery was performed in the sciatic nerve to establish neuropathic pain-related anxiety model.On the 21 st day after surgery,Von-Frey hairs test was used to detect mechanical hyperalgesia.The open field test(OFT)and elevated plus maze(EPM)experiments were used to detect anxiety-like behaviors.16 S rDNA sequencing was used to analyze the gut microbiota.Results The mice in the model group showed decreasing mechanical thresholds in the Von Frey test(P<0.001).On the 21 st day after SNI,the activity time of the mice entering the central area of OFT and the open arm area of EPM experiments were significantly less than those of the control group(P<0.05),suggesting that SNI mice had anxiety-like behaviors.The total distance of the model group and the control group in OFT and EPM experiments showed no significant difference.The analysis of gut microbiota showed that the gut microbiota structure in the SNI mice was disordered and the diversity of the flora was reduced.In the SNI mice,2β-proteobacteria were significantly reduced at the level of phylum classification,Lactobacillus was significantly reduced at the order level,and Prevotella was significantly reduced at the family level.Conclusions Aged mice with neuropathic pain-related anxiety have anxiety-like behaviors and show significant changes in gut microbiota.