趋化因子CXCL10作为神经病理性疼痛生物标记物的研究

The study of chemokine CXCL10 as a biomarker of neuropathic pain

摘要:

摘 要 目的：目前临床上缺乏神经病理性疼痛诊断和预后判断的客观指标，本研究旨在检测神经病理性疼痛小鼠和人的脑脊液（Cerebrospinal Fluid，CSF）和血清中趋化因子CXCL10的表达情况。方法：结扎ICR小鼠L5脊神经（Spinal nerve ligation, SNL）构建神经病理性疼痛（Neuropathic Pain, NP）模型，足底注射福尔马林或完全弗氏佐剂（complete Freund’s adjuvant，CFA）建立炎症性疼痛模型；收集捐赠者的脑脊液和血液，采用Real-time PCR、半定量PCR、Western Blot、免疫荧光和ELISA方法，分别检测CXCL10和CXCR3的mRNA和蛋白表达、CSF和血清中CXCL10的表达。 结果：① Cxcl10在正常ICR小鼠的脾脏、淋巴结、背根神经节(dorsal root ganglion, DRG)、脊髓和脑中有不同程度的基础表达；② Cxcr3在正常ICR小鼠的脾脏、淋巴结、DRG、脊髓和脑中也有不同程度的基础表达；③与假手术组相比，SNL模型小鼠CSF与血清中CXCL10含量显著增加（P<0.05，P<0.01）；急性炎症性疼痛小鼠CSF和血清中CXCL10与对照组相比无显著变化（P>0.05）；慢性炎症性疼痛小鼠CSF中CXCL10与对照组相比无显著变化；血清中CXCL10显著增加（P<0.05）；④ 人的脊髓、DRG和淋巴结中表达CXCL10和CXCR3；⑤疱疹后神经痛患者CSF与血清中CXCL10与对照组相比显著增加（P<0.05），骨性关节炎患者CSF和血清中CXCL10无显著增加。结论：神经病理性小鼠CSF和血清以及疱疹后神经痛患者CSF和血清中CXCL10表达显著增加，CXCL10可能作为神经病理性疼痛的生物标志物。

Abstract:

Abstract Objective: Objective biomarkers of neuropathic pain status and progression are still lacking. The aim of this study was to determine CXCL10 levels in the serum and cerebrospinal fluid (CSF) in mice and human and to evaluate whether CXCL10 can be used as a biomarker in neuropathic pain. Methods: Neuropathic pain was produced by L5 spinal nerve ligation (SNL) in mice. Inflammatory pain was induced by injection of formalin or complete Freund’s adjuvant (CFA) in the hind paw. The mRNA expression of CXCL10 and CXCR3 in distinct tissues was assessed by real-time PCR (RT-PCR) and semi-quantitative PCR, and the protein expression was determined by immunofluorescence or western blotting (WB). CXCL10 levels in the serum and CSF were tested by ELISA. Results: ① Cxcl10 is expressed at different levels in spleen, lymph nodes, dorsal root ganglion (DRG), spinal cord, and brain from adult ICR mice; ② Cxcr3 is expressed at different levels in spleen, lymph nodes, DRG, spinal cord, and brain from adult ICR mice; ③ Compared with the control group, the CXCL10 content in the CSF and serum of SNL mice was significantly increased (P<0.05, P<0.01); There is no significant difference of CXCL10 in CSF and serum between naive mice and acute inflammatory pain mice (P>0.05); In chronic inflammatory pain mice, serum CXCL10 was significantly increased compared to the control group (P<0.05), but no change in CSF. ④ The expression of CXCL10 and CXCR3 was observed in human DRG, spinal cord, and lymph node; ⑤ The CSF and serum levels of CXCL10 were elevated in patients with postherpetic pain (P<0.05), but not in patients with osteoarthritis. Conclusion: Our results indicate that the CXCL10 content is significantly increased in the serum or CSF of both mouse and human experiencing neuropathic pain. Thus, CXCL10 may serve as a possible objective diagnostic and/or prognostic marker of neuropathic pain.