METHODS: We analyzed the levels of NETs DNA and platelet-derived extracellular vesicles (pEVs) from 50 SLE patients and 20 healthy control subjects. The effects of pEVs on NETs formation were evaluated by using immunofluorescence assay and myeloperoxidase-DNA PicoGreen assay. The regulatory mechanism of pEVs on NETs formation and inflammatory cytokines production were investigated using an in vitro cell-based assay.
RESULTS: Increased circulating NETs DNA and pEVs were shown in SLE patients and were associated with disease activity (P < 0.005). We demonstrated that SLE patient-derived immune complexes (ICs) induced platelet activation, followed by pEVs release. ICs-triggered NETs formation was significantly enhanced in the presence of pEVs through Toll-like receptor (TLR) 8 activation. Increased levels of tRF-His-GTG-1 in pEVs and neutrophils of SLE patients were associated with disease activity. tRF-His-GTG-1 interacted with TLR8 to prime p47phox phosphorylation in neutrophils, resulting in reactive oxygen species production and NETs formation. Additionally, tRF-His-GTG-1 modulated NF-κB and IRF7 activation in neutrophils upon TLR8 engagement, resulting IL-1β, IL-8, and interferon-α upregulation, respectively.
CONCLUSIONS: The level of tRF-His-GTG-1 was positively correlated with NETs formation in SLE patients; tRF-His-GTG-1 inhibitor could efficiently suppress ICs-triggered NETs formation/hyperactivation, which may become a potential therapeutic target.
Neutrophils and platelets are key members in the immunopathogenesis of SLE. EVs play a key role in intercellular communication. Abnormal NETs formation promotes vascular complications and organ damage in SLE patients. tsRNA is a novel regulatory small non-coding RNA and participates in diverse pathological processes. Herein, we showed that SLE patient-derived ICs activates platelets directly, followed by intracellular tRF-His-GTG-1 upregulation, which is loaded into pEVs. The pEV-carried tRF-His-GTG-1 could interact with TLR8 in neutrophils, followed by activation of the downstream signaling pathway, including p47phox-NOX2-ROS, which causes NETs enhancement, while IRF7 promotes the expression of IFN-α. The tRF-His-GTG-1 inhibitor could suppress efficiently SLE ICs-induced NETs formation and pEVs primed NETs enhancement. This study offers new molecular machinery to explain the association between the platelets-derived tsRNAs, pEVs, and hyperactive NETs formation in lupus. tRF-His-GTG-1 may serve as a potential therapeutic target and help to advance our understanding of tsRNAs in SLE pathogenesis.
方法:我们分析了50名SLE患者和20名健康对照受试者的NETsDNA和血小板衍生的细胞外囊泡(pEVs)水平。通过使用免疫荧光测定法和髓过氧化物酶-DNAPicoGreen测定法评估了pEV对NETs形成的影响。使用体外基于细胞的测定法研究了pEV对NETs形成和炎性细胞因子产生的调节机制。
结果:在SLE患者中显示循环NETsDNA和pEV增加,并与疾病活动性相关(P<0.005)。我们证明SLE患者来源的免疫复合物(IC)诱导血小板活化,其次是电动汽车的释放。在pEV存在下,通过Toll样受体(TLR)8激活,IC触发的NETs形成显著增强。SLE患者pEV和中性粒细胞中tRF-His-GTG-1水平升高与疾病活动性相关。tRF-His-GTG-1与TLR8相互作用以引发中性粒细胞中的p47phox磷酸化,导致活性氧的产生和NET的形成。此外,tRF-His-GTG-1在TLR8参与时调节中性粒细胞中NF-κB和IRF7的激活,导致IL-1β,IL-8和干扰素-α上调,分别。
结论:SLE患者tRF-His-GTG-1水平与NETs形成呈正相关;tRF-His-GTG-1抑制剂可有效抑制IC引发的NETs形成/过度激活,这可能成为潜在的治疗靶点。
中性粒细胞和血小板是SLE免疫发病机制中的关键成员。电动汽车在细胞间通讯中起着关键作用。NETs的异常形成促进了SLE患者的血管并发症和器官损伤。tsRNA是一种新型的非编码小分子调控RNA,参与多种病理过程。在这里,我们发现SLE患者来源的IC直接激活血小板,随后是细胞内tRF-His-GTG-1上调,它被加载到pEV中。pEV携带的tRF-His-GTG-1可以与中性粒细胞中的TLR8相互作用,然后激活下游信号通路,包括p47phox-NOX2-ROS,这导致NET增强,而IRF7促进IFN-α的表达。tRF-His-GTG-1抑制剂可以有效抑制SLEIC诱导的NETs形成和pEV引发的NETs增强。这项研究提供了新的分子机制来解释血小板来源的tsRNAs之间的关联。电动汽车,和狼疮中过度活跃的NETs形成。tRF-His-GTG-1可能是一个潜在的治疗靶点,有助于促进我们对tsRNA在SLE发病机制中的理解。