DNase1L3分泌减少和相关抗体诱发散发性SLE患者NET降解障碍

Decreased DNase1L3 secretion and associated antibodies induce impaired degradation of NETs in patients with sporadic SLE

目的 探讨DNA酶1(DNase1)和DNA酶1样分子3(DNase1L3)活性改变与散发性系统性红斑狼疮(SLE)患者人群中中性粒细胞胞外诱捕网(NET)降解受损相关性及发生机制。方法 募集46例散发性SLE患者和30名正常个体,采用ELISA检测DNase1、 DNase1L3及相应自身抗体,免疫沉淀法分离样本DNase1和DNase1L3,改进的免疫荧光法检测NET和酶降解活性,酶联免疫斑点实验(ELISPOT)、 Western blot法和反转录PCR分析外周血单个核细胞(PBMC)分泌DNase1L3能力。结果H3-dsDNA和Ela-dsDNA两种复合物在SLE人群中的水平显著升高;低密度中性粒细胞(LDG)在SLE人群中的水平显著高于正常人群,LDG与H3-dsDNA和Ela-dsDNA两种NET复合物具有显著正相关性。SLE患者血浆体外降解NET的能力显著低于正常人群;DNase1和DNase1L3不同比例的综合降解实验显示DNase1L3降低是影响NET残留升高的关键;SLE患者人群DNase1L3自身抗体也显著高于正常人群;SLE患者PBMC分泌DNase1L3的能力相对正常人群减退。结论 DNase1L3分泌减少和相关自身抗体的存在是SLE人群NET降解能力减退的主要因素,为SLE患者病情监测和治疗提供新的方向。

Objective To evaluate the correlation between alterations in DNase1 and DNase1L3 enzyme activities and impairment of NET degradation in patients with sporadic SLE,and to investigate the underlying mechanism.Methods 46 sporadic SLE patients and 30 age-and sex-matched healthy individuals were recruited.Serum levels of DNase1,DNase1L3 and corresponding autoantibodies were detected by ELISA.DNase1 and DNase1L3 were isolated by immunoprecipitation;NETs and enzyme degradation activities were detected using a modified immunofluorescence.DNase1L3 secretion by PBMCs was analyzed by ELISPOT,Western blotting and reverse transcription PCR.Results Levels of H3-dsDNA and Ela-dsDNA complexes were significantly elevated in SLE patients.LDGs in SLE population was significantly higher than in the control group,and LDGs was positively correlated with H3-dsDNA and Ela-dsDNA NETs complexes.The ability of SLE patients to degrade NET in vitro was significantly lower than that of the control group.Degradation experiments of DNase1 and DNase1L3 in different proportions showed that the decrease in DNase1L3 activity was the primary contributor to the elevated NET residue level.The concentration of DNase1L3 autoantibodies in SLE patients was significantly elevated compared to the control group.In addition,the capacity of PBMCs to secrete DNase1L3 was significantly lower in the SLE patients compared to the control group.Conclusion Decreased secretion of DNase1L3 and the presence of relevant autoantibodies notably impede NET degradation in patients with SLE,offering new directions for the monitoring and treatment of SLE patients.