敲除背根神经节Fcgr1减弱类风湿关节炎模型大鼠NF-κB/NLRP3通路活化

Knocking out Fcgr1 of dorsal root ganglion attenuates the activation of NF-κB/NLRP3 pathway in a rat model of rheumatoid arthritis

目的探讨外周神经元FcγRⅠ调控类风湿关节炎疼痛的机制。方法利用野生型SD大鼠和条件敲除Fcgr1大鼠建立类风湿关节炎模型。设野生型大鼠对照组(control组)、野生型大鼠类风湿关节炎(RA)组和条件敲除Fcgr1大鼠类风湿关节炎(CKO+RA)组,每组7只。用痛觉行为学检测各组大鼠建模前第3、1 d,建模后第3、5、7、9 d机械痛阈值和热痛阈值变化,用荧光原位杂交实验检测条件敲除Fcgr1大鼠背根神经节(DRG)中是否表达Fcgr1 mRNA,用免疫荧光实验检测大鼠DRG中pNF-κB(p65)、NLRP3、IL-1β和IL-18表达和脊髓背角(SDH)胶质细胞活化。结果与control组比较,RA组和(CKO+RA)组大鼠机械和热疼痛阈值均降低,(CKO+RA)组大鼠机械和热疼痛阈值比RA组大鼠明显提高(P<0.05);与RA组大鼠相比,(CKO+RA)组大鼠DRG中pNF-κB(p65)、NLRP3、IL-1β和IL-18表达明显下调(P<0.05);SDH中GFAP和Iba1表达降低(P<0.05)。结论DRG神经元FcγRⅠ可能通过NF-κB/NLRP3通路促进神经元炎性细胞因子IL-1β和IL-18合成释放,引起SDH胶质细胞活化,参与类风湿关节炎疼痛。

Objective To explore the mechanism of peripheral neurons FcγRⅠregulating pain caused by rheumatoid arthritis.Methods Rheumatoid arthritis models were established in 14 wild-type SD rats and 7 Fcgr1 conditional knockout rats.Wild-type rat control group(control group),rheumatoid arthritis group of wild-type rat(RA group)and rheumatoid arthritis group of Fcgr1 conditional knockout rat(RA+CKO group)were established.Pain behavior was used to detect the changes of mechanical pain threshold and thermal pain threshold 3 and 1 days before modeling and 3,5,7 and 9 days after modeling.The expression of Fcgr1 mRNA indorsal root ganglion(DRG)of Fcgr1 conditional knockout rat was detected by fluorescence in situ hybridization.Immunofluorescence staining was used to detect the changes of IL-1βand IL-18 expression in the DRG and activation of glial cells in the spinal dorsal horn(SDH).Results Compared with the control group,the threshold of mechanical and thermal pain in RA group and(RA+CKO)group were decreased(P<0.05),the mechanical and thermal pain thresholds of the(RA+CKO)group were significantly higher than of RA group(P<0.05).Compared with the RA group,the expression of pNF-κB,NLRP3,IL-1βand IL-18 and the protein level of GFAP and Iba1 in the SDH of(RA+CKO)rats were significantly decreased(P<0.05).Conclusions FcγRⅠof DRG neurons may promote the synthesis and release of inflammatory cytokines IL-1βand IL-18 through NF-κB/NLRP3 pathway,and cause glial cells activation in the SDH,which may play a role in the mechanism causing pain of rheumatoid arthritis.