Netrin-1在类风湿关节炎滑膜组织中的表达及作用研究

Expressions and roles of Netrin-1 in rheumatoid arthritis

目的探讨Netrin-1在类风湿关节炎(rheumatoid arthritis,RA)滑膜组织中的表达及作用。方法收集2012年7月至2017年10月来我院就诊的RA患者;免疫组化检测滑膜组织中Netrin-1的表达和B细胞的比例;流式检测外周血中调节性B细胞(Breg)的比例;收集RA患者的外周血,采用人淋巴细胞分离液分离外周血中的淋巴细胞,流式检测CD19+IL-10+Breg的比例。结果免疫组化的结果显示,RA组CD19+B细胞的数目显著高于对照组[(64.24±7.41)vs.(4.40±1.34)]mm^2,差异有统计学意义(t=7.471,P<0.001)。相关性分析的结果显示Netrin-1的表达与B细胞的数目,有明显的负相关性(r=-0.8049,P<0.001)。流式结果显示,RA组外周血中CD19+B细胞的比例显著高于对照组[(2.64±0.38)vs.(1.73±0.22)]%,差异有统计学意义(t=4.013,P<0.001)。RA组CD19+IL-10+Breg数目显著低于对照组[(1.86±0.38)vs.(6.58±0.87)]%,差异有统计学意义(t=6.526,P<0.001)。相关性分析的结果显示Netrin-1的表达与外周血中Breg比例具有显著的正相关性(r=0.7256,P<0.001)。体外实验结果显示,Netrin-1低浓度组及Netrin-1高浓度组B细胞比例均显著低于RA组[(16.27±3.45)vs.(7.33±1.02)vs.(4.24±0.68)]%,差异有统计学意义(t=3.320,P=0.029;t=4.858,P=0.008)。Netrin-1低浓度组及Netrin-1高浓度组Breg比例均显著高于RA组[(2.23±0.25)vs.(3.57±0.39)vs.(4.61±0.86)]%,差异有统计学意义(t=4.899,P<0.001;t=6.887,P<0.001)。结论Netrin-1在RA滑膜组织中低表达,Netrin-1可能通过促进Breg的分化,对RA的治疗具有一定的作用。

Objective To investigate expressions and roles of Netrin-1 in synovial tissues of rheumatoid arthritis( RA). Methods Clinical data of RA patients were collected from July 2012 to October 2017. Immunohistochemistry was used to detect expressions of Netrin-1 and the proportion of CD19 + B cells in synovial tissues. The lymphocyte in the peripheral blood was separated by human lymphocyte separation solution. Flow cytometry was applied to detect the proportion of regulatory B cells( Breg) and CD19 + IL-10 + Breg in the peripheral blood. Results Immunohistochemistry showed that the number of CD19 + B cells in RA group was significantly higher than that in the control group [( 64.24 ± 7.41) vs.( 4.40 ± 1.34) mm^2 ],( t = 7.471, P < 0.001). Correlation analysis demonstrated that the expression of Netrin-1 was negatively correlated with the number of B cells( r =-0.8049, P < 0.001). Flow cytometry indicated that the proportion of CD19 + B cells in the peripheral blood of RA group was significantly higher than that in the control group [( 2.64 ± 0.38) vs.( 1.73 ± 0.22) % ] with statistically significant differences( t = 4.013, P < 0.001). The number of CD19 + IL-10 + Breg in RA group was significantly lower than that in the control group [( 1.86 ± 0.38) vs.( 6.58 ± 0.87) % ] with statistically significant differences( t = 6.526, P < 0.001). Correlation analysis suggested that there was a significant positive correlation between the expression of Netrin-1 and the proportion of Breg in the peripheral blood( r = 0.7256, P < 0.001). In vitro experiments showed that the proportions of B cells in Netrin-1 low concentration group and Netrin-1 high concentration group were significantly lower than that in RA group [( 16.27 ± 3.45) vs.( 7.33 ± 1.02) vs.( 4.24 ± 0.68) % ] with statistically significant differences( t = 3.320, P = 0.029;t = 4.858, P = 0.008). The proportions of Breg in Netrin-1 low concentration group and Netrin-1 high concentration group were significantly higher than that in RA group [( 2.23 ± 0.25) vs.( 3.57 ± 0.39) vs.( 4.61 ± 0.86) % ] with statistically significant differences( t = 4.899, P < 0.001;t = 6.887, P < 0.001). Conclusions Netrin-1 is low-expressed in synovial tissues of RA. Netrin-1 can play a certain role by promoting Breg differentiation in the treatment of RA.