重组硫酸软骨素蛋白SRPX2减轻小鼠葡聚糖硫酸钠诱导的结肠炎的作用

Effect of recombinant SRPX2 in ameliorating murine dextran sulfatesodium induced colitis

目的评价sushi重复蛋白X连锁2蛋白(SRPX2)在葡聚糖硫酸钠(DSS)诱导的实验性结肠炎小鼠中的作用及其可能机制。方法 DSS+SRPX2组,DSS组小鼠各5只,自第1天起给予5%DSS溶液自由饮用,分别给予SRPX2重组蛋白及0.9%氯化钠溶液腹腔注射5 d,至第6天处死小鼠。另设正常对照组(不予处理)。记录各组小鼠疾病活动度(DAI)评分、结肠组织学评分;检测结肠组织髓过氧化物酶(MPO)活性;分离固有层单个核细胞(LPMC),酶联免疫吸附实验法检测LPMC中肿瘤坏死因子α(TNF-α)、核因子κB(NF-κB)的表达;比色法试剂盒检测N6-腺苷酸甲基化(m~6A)修饰的RNA的水平。结果 DSS组小鼠第5天的DAI评分较正常对照组明显升高(P <0.01),DSS+SRPX2组DAI评分较DSS组均明显降低(P <0.05)。处死小鼠后,DSS组小鼠结肠组织学评分及MPO活性较正常对照组均明显升高(P <0.05),DSS+SRPX2组小鼠结肠的组织学评分及MPO活性均较DSS组明显降低(P <0.05)。DSS组小鼠LPMC中TNF-α、NF-κB水平较正常对照组均明显升高(P <0.05),DSS+SRPX2组小鼠LPMC中TNF-α、NF-κB水平均较DSS组明显降低(P <0.05)。DSS组小鼠LPMC中m~6A修饰的RNA的比例较正常对照组明显升高(P <0.05),而DSS+SRPX2组小鼠LPMC中m~6A修饰的RNA的比例较DSS组明显降低(P <0.05)。结论 SRPX2重组蛋白具有减轻DSS诱导的小鼠实验性结肠炎的作用,其作用可能与改变结肠组织LPMC中m~6A甲基化RNA的水平有关。

Objective To investigate the role of sushi repeat-containing protein X-linked 2(SRPX2)in relieving dextran sulfatesodium(DSS)induced colitis and possible mechanism.Methods 5%DSS was given to mice in DSS and DSS+SRPX2 group from the 1st day to the 6th day.Peritoneal injection of saline and recombinant SRPX2 protein were administered to all mice every day.DAI score,histology score was recorded.MPO activity was measured,lamina propria mononuclear cells(LPMC)were separated and the level of tumor necrosis factor alpha(TNF-α)and nuclear factor-κB(NF-κB)in LPMC of mice were determined using enzyme-linked immunosorbent assay(ELISA),m 6A RNA level was measured using colometric assay.Results DAI scores of the DSS group mice on the 5th day were higher than those of normal control group,and DAI in DSS+SRPX2 group were all lower than DSS group(P<0.05).After sacrificing of mice,colonic histology scores and MPO activity of mice in DSS group were higher than normal control group,and colonic histology scores and MPO activity of mice in DSS+SRPX2 group were lower than those of DSS group(P<0.05).The lelves of TNF-αand NF-κB in LPMC of mice in DSS group were higher than those of normal control group,and lelves of TNF-αand NF-κB in LPMC of mice in DSS+SRPX2 group were significantly lower than those of DSS group(P<0.05).The percentage of m 6A RNA in LPMC of mice in DSS group was signifcantly higher than that of normal control group(P<0.05),while the percentage in DSS+SRPX2 group was significanly lower than that of DSS group(P<0.05).Conclusion SRPX2 may ameliorate DSS induced colitis in mice via modulating the percentage of m 6A methylation RNA in LPMCs.