IL-37, the anti-inflammatory cytokine of the IL-1 family, plays several key roles in the regulation of autoimmune diseases. Yet, its role in Hashimoto's thyroiditis (HT) is not clear. In the present study, we found that, in tissues from HT patients, most of the follicular epithelial cells were positive for both IL-37 and single Ig IL-1-related receptor (SIGIRR) by immunohistochemical staining, while the infiltrating lymphocytes and other inflammatory cells hardly expressed any. Meanwhile, mRNA expression levels of IL-37 in peripheral blood mononuclear cells (PBMC) of HT patients were significantly higher than those in normal controls measured by quantitative real-time PCR. Finally, we studied the possible role of IL-37 in IFN-γ-stimulated rat FRTL-5 cells. The results showed that IL-1β, TNF-α, and MCP-1 mRNA levels were significantly decreased, while the expression of IL-4 mRNA was dramatically up-regulated in IFN-γ-stimulated rat thyroid cell line FRTL-5 pre-treated with IL-37. The current study, for the first time, demonstrated that the IL-37 network is involved in Hashimoto's thyroiditis, and IL-37 signaling pathway may ameliorate the excessive autoimmune responses in this chronic lymphocytic thyroiditis.

中文翻译：

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IL-37信号通路在自身免疫性桥本甲状腺炎的反馈调节中的潜在作用。

IL-37是IL-1家族的抗炎细胞因子，在自身免疫性疾病的调节中起着关键作用。然而，其在桥本甲状腺炎（HT）中的作用尚不清楚。在本研究中，我们发现，在HT患者的组织中，通过免疫组织化学染色，大多数滤泡上皮细胞的IL-37和单个Ig IL-1相关受体（SIGIRR）均为阳性，而浸润的淋巴细胞和其他炎性细胞几乎不表达任何。同时，通过实时荧光定量PCR检测，HT患者外周血单个核细胞（PBMC）中IL-37的mRNA表达水平显着高于正常对照组。最后，我们研究了IL-37在IFN-γ刺激的大鼠FRTL-5细胞中的可能作用。结果显示，IL-1β，TNF-α和MCP-1 mRNA水平显着降低，而在IL-37预处理的IFN-γ刺激的大鼠甲状腺细胞FRTL-5中，IL-4 mRNA的表达显着上调。当前的研究首次证明IL-37网络与桥本甲状腺炎有关，而IL-37信号传导途径可减轻这种慢性淋巴细胞性甲状腺炎的过度自身免疫反应。