Zhang Long, Zhao Jin-Song, Zhou Li, Chen Lei, Feng Zhi-Ying
Department of Anesthesiology,Ningbo No.6 Hospital,Ningbo,Zhejiang 315040,China.
Department of Pain Medicine,The First Affiliated Hospital of Zhejiang University School of Medicine,Hangzhou 310000,China.
Zhongguo Yi Xue Ke Xue Yuan Xue Bao. 2025 Aug;47(4):509-518. doi: 10.3881/j.issn.1000-503X.16494.
Objective To explore the functional mechanism of spinal cord fragile X mental retardation protein(FMRP)involved in neuropathic pain(NP)by using the sciatic nerve model of chronic compression injury(CCI).Methods First,to investigate the changes of spinal cord FMRP and β-catenin following the development of NP,this study compared the 50%mechanical withdrawal threshold(MWT)and thermal withdrawal latency(TWL)in CCI rats,as well as changes of FMRP and β-catenin in the spinal dorsal horn post-surgery,through random grouping.Immunofluorescence staining was performed on spinal cord tissue sections from CCI rats.Second,to further validate the alterations in pain behavior when the FMRP function was lost,we measured the 50%MWT,TWL,and FMRP and β-catenin in the spinal dorsal horn after FMRP knockdown in CCI rats.Finally,we measured the 50%MWT,TWL,and FMRP and β-catenin in the case of FMRP hyperfunction for validation.Results Compared with the baseline CCI group and the naive and sham groups after modeling,the CCI group after modeling showed decreases in 50%MWT and TWL(all <0.001).After modeling,compared with the naive group and the sham group,the CCI group presented up-regulated expression of FMRP(=0.027,=0.022)and β-catenin(<0.001,=0.001)in the spinal dorsal horn.No co-localization of FMRP with astrocytes and microglia was observed in the spinal cord,while the co-localization with neurons was observed.Compared with the baseline,the CCI+FMRP knockdown group showed decreases in 50%MWT(=0.015)and TWL(=0.001)after modeling.After intrathecal injection of small interfering RNA(siRNA),the 50%MWT(=0.020)and TWL(=0.009)of the CCI+FMRP knockdown group were increased.Moreover,compared with the CCI group and the CCI+solvent group,the CCI+FMRP knockdown group showed increases in 50%MWT(both <0.001)and TWL(=0.005,=0.006).After intrathecal injection of siRNA,the expression levels of FMRP(=0.012,=0.007)and β-catenin(both <0.001)in the spinal dorsal horn of the CCI+FMRP knockdown group were lower than those of the CCI group and the CCI+solvent group.Compared with the baseline FMRP overexpression group and the naive and negative control groups after adeno-associated virus(AAV)injection,the FMRP overexpression group after AAV injection showed decreases in 50%MWT and TWL(all <0.001).After AAV injection,compared with the naive group and the negative control group,the FMRP overexpression group demonstrated up-regulated expression of FMRP(both <0.001)and β-catenin(=0.006,=0.008)in the spinal cord.Conclusions This study confirms that spinal cord FMRP and β-catenin are involved in NP induced by CCI.Spinal cord FMRP may be one of the potential therapeutic targets for NP.
目的 采用坐骨神经慢性压迫损伤（CCI）模型，探讨脊髓脆性X智力低下蛋白（FMRP）参与神经性疼痛（NP）的作用机制。方法 首先，为研究NP发生过程中脊髓FMRP和β-连环蛋白的变化，本研究通过随机分组，比较了CCI大鼠的50%机械缩足阈值（MWT）和热缩足潜伏期（TWL），以及术后脊髓背角中FMRP和β-连环蛋白的变化。对CCI大鼠的脊髓组织切片进行免疫荧光染色。其次，为进一步验证FMRP功能丧失时疼痛行为的改变，我们检测了CCI大鼠FMRP基因敲低后50%MWT、TWL以及脊髓背角中FMRP和β-连环蛋白的变化。最后，在FMRP功能亢进的情况下进行检测以作验证。结果 与建模后的基线CCI组以及假手术组和正常组相比，建模后的CCI组50%MWT和TWL降低（均<0.001）。建模后，与正常组和假手术组相比，CCI组脊髓背角中FMRP表达上调（=0.027，=0.022），β-连环蛋白表达上调（<0.001，=0.001）。脊髓中未观察到FMRP与星形胶质细胞和小胶质细胞的共定位，但观察到与神经元的共定位。与基线相比，CCI+FMRP基因敲低组建模后50%MWT（=0.015）和TWL（=0.001）降低。鞘内注射小干扰RNA（siRNA）后，CCI+FMRP基因敲低组的50%MWT（=0.020）和TWL（=0.009）升高。此外，与CCI组和CCI+溶剂组相比，CCI+FMRP基因敲低组50%MWT（均<0.001）和TWL（=0.005，=0.006）升高。鞘内注射siRNA后，CCI+FMRP基因敲低组脊髓背角中FMRP表达水平（=0.012，=0.007）和β-连环蛋白表达水平（均<0.001）低于CCI组和CCI+溶剂组。与腺相关病毒（AAV）注射后的基线FMRP过表达组以及正常组和阴性对照组相比，AAV注射后的FMRP过表达组50%MWT和TWL降低（均<0.001）。AAV注射后，与正常组和阴性对照组相比，FMRP过表达组脊髓中FMRP表达上调（均<0.001），β-连环蛋白表达上调（=0.006，=0.008）。结论 本研究证实脊髓FMRP和β-连环蛋白参与CCI诱导的NP。脊髓FMRP可能是NP的潜在治疗靶点之一。
