Department of Clinical Immunology and Rheumatology, Hiroshima University Hospital, 1-2-3 Kasumi, Minami, Hiroshima, 734-8551, Japan.
Division of Respirology, Neurology and Rheumatology, Department of Medicine, Kurume University School of Medicine, 67 Asahi, Kurume, Fukuoka, 830-0011, Japan.
Inflammation. 2018 Oct;41(5):1945-1954. doi: 10.1007/s10753-018-0838-z.
Aberrant endochondral bone formation in the physis is a unique bone lesion in neonatal-onset multisystem inflammatory disease (NOMID), also called chronic infantile neurologic cutaneous articular (CINCA), the most severe of the cryopyrin-associated periodic syndrome (CAPS) diseases, which are interleukin-1β (IL-1β)-related monogenic autoinflammatory diseases. The wingless (Wnt) pathway plays an important role in osteoblast differentiation. In this study, we explored the potential role of IL-1β on the expression of WNT genes and the Wnt antagonist Dickkopf-1 (DKK1). The expression of WNT and DKK1 in fibroblast-like synoviocytes (FLS), which are articular resident cells, was quantified by quantitative PCR and enzyme-linked immunosorbent assay. Additionally, we used T cell factor (TCF) reporter assays to evaluate the activity of the canonical Wnt signal pathway in the presence or absence of the supernatant of cultured FLS treated with or without IL-1β and IL-6. Anti-DKK1 antibodies were used to neutralize DKK1. The expression of both canonical and non-canonical WNT genes as well as DKK1 was observed in FLS. The supernatant of cultured FLS suppressed the luciferase activity of the TCF reporter, and this effect was reduced by its pre-treatment with an anti-DKK1 antibody. Both IL-1β and IL-6 significantly reduced DKK1 production. Furthermore, the supernatant of FLS cultured with IL-1β or IL-6 showed a reduced inhibitory effect on Wnt signaling, compared with the supernatant of untreated FLS. These data suggest that IL-1β, like IL-6, dampens DKK1 production, and thereby promotes Wnt signal activation. Therefore, increased levels of IL-1β may contribute to the dysregulation of endochondral ossification in NOMID/CINCA.
骺板内的异常软骨内骨形成是新生儿发病的多系统炎症性疾病（NOMID）的一种独特的骨病变，也称为慢性婴儿神经皮肤关节病（CINCA），这是一种最严重的 Cryopyrin 相关周期性综合征（CAPS）疾病，属于白细胞介素-1β（IL-1β）相关的单基因自身炎症性疾病。无翅型（Wnt）信号通路在成骨细胞分化中发挥重要作用。在这项研究中，我们探讨了 IL-1β对 WNT 基因和 Wnt 拮抗剂 Dickkopf-1（DKK1）表达的潜在作用。通过定量 PCR 和酶联免疫吸附试验定量测定关节驻留细胞成纤维样滑膜细胞（FLS）中 WNT 和 DKK1 的表达。此外，我们使用 T 细胞因子（TCF）报告基因测定法，评估在有无培养的 FLS 上清液存在的情况下，IL-1β和 IL-6 处理或未处理的 FLS 上清液对经典 Wnt 信号通路活性的影响。使用抗 DKK1 抗体中和 DKK1。在 FLS 中观察到经典和非经典 WNT 基因以及 DKK1 的表达。培养的 FLS 的上清液抑制了 TCF 报告基因的荧光素酶活性，而用抗 DKK1 抗体预处理可降低其抑制作用。IL-1β 和 IL-6 均显著降低了 DKK1 的产生。此外，与未经处理的 FLS 的上清液相比，用 IL-1β 或 IL-6 培养的 FLS 的上清液对 Wnt 信号的抑制作用降低。这些数据表明，IL-1β 与 IL-6 一样，可抑制 DKK1 的产生，从而促进 Wnt 信号的激活。因此，IL-1β 水平的升高可能导致 NOMID/CINCA 中软骨内骨化的失调。
