CCN1 Promotes Inflammation by Inducing IL-6 Production via α6β1/PI3K/Akt/NF-κB Pathway in Autoimmune Hepatitis.
CCN1 Promotes Inflammation by Inducing IL-6 Production via α6β1/PI3K/Akt/NF-κB Pathway in Autoimmune Hepatitis.
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自身免疫性肝炎CCN1通过α6β1/PI3K/Akt/NF-κB通路诱导IL-6产生促进炎症
DOI：
10.3389/fimmu.2022.810671
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发表时间：
2022
影响因子：
7.3
通讯作者：
中科院分区：
文献类型：
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自身免疫性肝炎（AIH）是一种病因不明的慢性炎症性肝病。 CCN1是一种细胞外基质相关蛋白，与癌症、炎症、肝纤维化甚至自身免疫性疾病有关。然而，CCN1 在 AIH 中发挥的作用仍不清楚。在本研究中，通过实时PCR、蛋白质印迹和免疫组织化学（IHC）检测肝脏中CCN1的表达。采用ELISA法检测血清中CCN1水平。 CCN1的诊断价值通过受试者工作特征（ROC）曲线分析确定。 CCN1 条件敲除 (CCN1 fl/fl Cre+) 小鼠是通过 CCN1 fl/fl C57BL/6J 和 CAG-Cre-ERT C57BL/6J 小鼠交配产生的。采用刀豆球蛋白A（ConA）诱导自身免疫性肝炎小鼠模型。通过蛋白质印迹法测定 IKKα/β、IκBα、NF-κB p65 和 Akt 磷酸化。通过免疫荧光检查 NF-κB p65 核转位。在这里，我们发现CCN1在AIH患者的肝细胞中过度表达。与健康对照（HC）相比，AIH 患者血清中的 CCN1 水平也有所升高。 ROC曲线分析结果显示，血清CCN1能够区分AIH患者和HD患者。在 ConA 诱导的肝炎小鼠模型中，CCN1 条件敲除 (CCN1 fl/fl Cre+) 通过降低 ALT/AST 水平和 IL-6 表达来减轻炎症。在体外，CCN1 处理显着诱导 LO2 细胞产生 IL-6。此外，CCN1 敲低会减弱 IL-6 的产生。此外，我们发现CCN1可以通过与α6β1受体结合，通过PI3K/Akt/NF-κB信号通路激活IL-6的产生。总之，我们的结果揭示了 CCN1 通过上调 AIH 中 IL-6 的产生而促进炎症的新作用。我们的研究还表明，靶向 CCN1 可能代表 AIH 治疗的一种新策略。
Autoimmune hepatitis (AIH) is a chronic inflammatory liver disease with unknown etiology. CCN1, an extracellular matrix-associated protein, is associated with carcinoma, inflammation, liver fibrosis, and even autoimmune diseases. However, the role that CCN1 plays in AIH has remained undetermined. In this study, expression of CCN1 in liver was detected by real-time PCR, western blot and immunohistochemistry (IHC). CCN1 level in serum was detected by ELISA. Diagnostic value of CCN1 was determined by receiver operating characteristic (ROC) curve analysis. CCN1 conditional knockout (CCN1 fl/fl Cre+) mice were generated by mating CCN1 fl/fl C57BL/6J and CAG-Cre-ERT C57BL/6J mice. Autoimmune hepatitis mice model was induced by concanavalin A (ConA). IKKα/β, IκBα, NF-κB p65 and Akt phosphorylation were determined by western blot. NF-κB p65 nuclear translocation was examined by immunofluorescence. Here, we found that CCN1 was over-expressed in hepatocytes of AIH patients. CCN1 level also increased in serum of AIH patients compared to healthy controls (HC). ROC curve analysis results showed that serum CCN1 was able to distinguish AIH patients from HD. In ConA induced hepatitis mice model, CCN1 conditional knockout (CCN1 fl/fl Cre+) attenuated inflammation by reducing ALT/AST level and IL-6 expression. In vitro, CCN1 treatment dramatically induced IL-6 production in LO2 cells. Moreover, the production of IL-6 was attenuated by CCN1 knockdown. Furthermore, we showed that CCN1 could activate IL-6 production via the PI3K/Akt/NF-κB signaling pathway by binding to α6β1 receptor. In summary, our results reveal a novel role of CCN1 in promoting inflammation by upregulation of IL-6 production in AIH. Our study also suggests that targeting of CCN1 may represent a novel strategy in AIH treatment.