Cao Run, Jing Jing, Ma Yuting, Qi Wenqing, Huang Xinyu, Zhang Chaofang, Lu Zhizhuo, He Jiayi, Wang Guiling, Ma Yuanfang, Zhang Hailong
Joint National Laboratory for Antibody Drug Engineering, the First Affiliated Hospital, Henan University, Kaifeng, Henan, People's Republic of China.
Xuzhou Central Hospital, Xuzhou, Jiangsu, People's Republic of China.
J Inflamm Res. 2025 Feb 5;18:1773-1786. doi: 10.2147/JIR.S503033. eCollection 2025.
Metformin (Met) is widely used to treat a variety of diseases, but its role in ulcerative colitis (UC) has not been fully elucidated. This study aimed to clarify the effect of Met on UC, exploring its relationship with NLRP3 inflammasome and elucidating the potential mechanisms.
C57BL/6J mice were administrated with DSS solution to establish UC model. Disease Activity Index (DAI) and hematoxylin and eosin staining (HE) were performed to evaluate the impact of Met on UC model. Enzyme-linked immunosorbent assay (ELISA), Reverse transcription - quantitative polymerase chain reaction (RT-qPCR), Western blotting (WB), immunohistochemistry, and immunofluorescence were used to detect NLRP3 inflammasome activation in vivo. Furthermore, in vitro, bone marrow-derived macrophages (BMDMs) selected to clarify the role of Met on NLRP3 inflammasome activation and the underlying mechanisms.
In vivo, Met could significantly inhibit the development of UC, characterized by decreased DAI, increased body weight and colorectal length, and the repair of damaged tissue. Met could also block macrophage infiltration and subsequently reduced the level of IL-1β, NLRP3, and Caspase-1 in the colorectal tissue, which were mainly expressed by macrophages. In addition, the level of IL-1β in serum was remarkedly down-regulated by Met. In vitro, Met could inhibit NLRP3 inflammasome activation and subsequently dampen the maturation of pro-caspase-1 and pro-IL-1β. Moreover, Met could simultaneously suppress the activation of NF-κB/p65 signaling pathway and disrupt the formation of ASC speck. At last, Met exhibited an anti-oxidant effect, along with upregulating the level of UCP2 and NCF1.
Met significantly ameliorated UC by inhibiting NLRP3 inflammasome activation in macrophages. The underlying mechanisms not only involved the inhibition of NF-κB signaling pathway activation (first signal), but was also associated with up-regulation of UCP2 and NCF1 levels and thus the repression of ROS generation (second signal).
二甲双胍（Met）被广泛用于治疗多种疾病，但其在溃疡性结肠炎（UC）中的作用尚未完全阐明。本研究旨在阐明Met对UC的影响，探讨其与NLRP3炎性小体的关系，并阐明潜在机制。
给C57BL/6J小鼠灌胃葡聚糖硫酸钠（DSS）溶液以建立UC模型。采用疾病活动指数（DAI）和苏木精-伊红染色（HE）评估Met对UC模型的影响。采用酶联免疫吸附测定（ELISA）、逆转录-定量聚合酶链反应（RT-qPCR）、蛋白质免疫印迹法（WB）、免疫组织化学和免疫荧光检测体内NLRP3炎性小体的激活情况。此外，在体外，选用骨髓来源的巨噬细胞（BMDMs）来阐明Met对NLRP3炎性小体激活的作用及其潜在机制。
在体内，Met可显著抑制UC的发展，表现为DAI降低、体重和结肠长度增加以及受损组织的修复。Met还可阻止巨噬细胞浸润，随后降低结肠组织中主要由巨噬细胞表达的IL-1β、NLRP3和半胱天冬酶-1的水平。此外，Met可显著下调血清中IL-1β的水平。在体外，Met可抑制NLRP3炎性小体的激活，随后抑制前半胱天冬酶-1和前IL-1β的成熟。此外，Met可同时抑制NF-κB/p65信号通路的激活并破坏凋亡相关斑点样蛋白（ASC）斑点的形成。最后，Met表现出抗氧化作用，同时上调解偶联蛋白2（UCP2）和中性粒细胞胞质因子1（NCF1）的水平。
Met通过抑制巨噬细胞中NLRP3炎性小体的激活显著改善UC。潜在机制不仅涉及抑制NF-κB信号通路的激活（第一信号），还与UCP2和NCF1水平的上调以及因此对活性氧生成的抑制（第二信号）有关。
