Department of Rheumatology, Fukushima Medical University School of Medicine, 1 Hikarigaoka, Fukushima, Fukushima, 960-1295, Japan.
BMC Res Notes. 2021 Dec 11;14(1):447. doi: 10.1186/s13104-021-05860-w.
Interferon-gamma (IFN-γ) is overexpressed in rheumatoid synovium and thought to be involved in the pathogenesis of rheumatoid arthritis (RA). In this study, we examined our hypothesis that IFN-γ activates innate immune cells and upregulates inflammatory cytokines. Peripheral blood neutrophils were stimulated with IFN-γ in the presence or absence of Janus kinase (JAK) inhibitors. Interleukin-6 (IL-6) mRNA and protein expression were analyzed using real-time polymerase chain reaction (PCR) method and enzyme-linked immunosorbent assay. Protein phosphorylation of JAKs or STAT1 was assessed by Western blot using phospho-specific antibodies.
IFN-γ stimulation induces IL-6 expression in protein and mRNA levels in human neutrophils. Furthermore, IFN-γ stimulation induces JAK1/JAK2 phosphorylation and downstream signal transducer and activator of transcription (STAT) 1 phosphorylation in human neutrophils. Although all JAKi, blocked IFN-γ-induced JAK1.2/STAT1 phosphorylation at higher concentrations (100 nM), baricitinib most efficiently inhibited IFN-γ-induced JAK1.2/STAT1 phosphorylation at lower concentrations (≤ 25 nM). Among these JAKi, baricitinib was the most potent regulator for IFN-γ-induced IL-6 production in human neutrophils. Our data indicate that IFN-γ upregulates IL-6 production via the JAK1/2-STAT1 pathway in human innate immune cells. Furthermore, this IFN-γ-mediated IL-6 induction via JAK/STAT was downregulated by JAKi.
γ干扰素（IFN-γ）在类风湿滑膜中过度表达，被认为参与了类风湿关节炎（RA）的发病机制。在本研究中，我们检验了我们的假设，即 IFN-γ 激活固有免疫细胞并上调炎症细胞因子。在存在或不存在 Janus 激酶（JAK）抑制剂的情况下，用 IFN-γ 刺激外周血中性粒细胞。使用实时聚合酶链反应（PCR）方法和酶联免疫吸附测定法分析白细胞介素-6（IL-6）mRNA 和蛋白表达。通过使用磷酸特异性抗体的 Western blot 评估 JAK 和 STAT1 的蛋白磷酸化。
IFN-γ 刺激诱导人中性粒细胞中 IL-6 的表达在蛋白和 mRNA 水平上。此外，IFN-γ 刺激诱导人中性粒细胞中 JAK1/JAK2 磷酸化和下游信号转导和转录激活因子（STAT）1 磷酸化。虽然所有 JAKi 在较高浓度（100 nM）时阻断 IFN-γ 诱导的 JAK1.2/STAT1 磷酸化，但巴瑞替尼在较低浓度（≤25 nM）时最有效地抑制 IFN-γ 诱导的 JAK1.2/STAT1 磷酸化。在这些 JAKi 中，巴瑞替尼是最有效的调节剂，可调节人中性粒细胞中 IFN-γ 诱导的 IL-6 产生。我们的数据表明，IFN-γ 通过 JAK1/2-STAT1 通路在上调人固有免疫细胞中的 IL-6 产生。此外，JAKi 下调了 IFN-γ 介导的 JAK/STAT 诱导的 IL-6 诱导。
