Department of Pharmacy, Jiangsu Health Vocational College, 150 Fenghuang W St, Gulou, Nanjing, Jiangsu 211800, China.
Department of Clinical Medicine, Jiangsu Health Vocational College, 150 Fenghuang W St, Gulou, Nanjing, Jiangsu 211800, China.
Int Immunopharmacol. 2024 Oct 25;140:112802. doi: 10.1016/j.intimp.2024.112802. Epub 2024 Jul 31.
Formononetin (FNT) is an isoflavone known for its anti-inflammatory properties and has been shown to reduce insulin resistance in Type 2 Diabetes Mellitus (T2DM). However, its effects and the underlying mechanisms in diabetic liver injury remain largely unexplored.
We established a T2DM-induced liver injury mouse model by feeding high-fat diet, followed by injecting streptozotocin. The mice were then treated with FNT and the liver function in these mice was assessed. Macrophage markers in FNT-treated T2DM mice or human THP-1 cells were evaluated using flow cytometry, RT-qPCR, and Western blotting. The expression of PTP1B and STAT6 in mouse liver tissues and THP-1 cells was analyzed. Molecular docking predicted the interaction between PTP1B and STAT6, which was validated via co-immunoprecipitation (Co-IP) and phos-tag analysis. Microscale thermophoresis (MST) assessed the binding affinity of FNT to PTP1B.
FNT treatment significantly ameliorated blood glucose levels, hepatocyte apoptosis, inflammatory response, and liver dysfunction in T2DM mice. Moreover, FNT facilitated M2 macrophage polarization in both T2DM mice and high glucose (HG)-induced THP-1-derived macrophages. The PTP1B/STAT6 axis, deregulated in T2DM mice, was normalized by FNT treatment, which counteracted the T2DM-induced upregulation of PTP1B and downregulation of phosphorylated STAT6. Molecular docking and subsequent analyses revealed that PTP1B binds to and dephosphorylates STAT6 at the S325A site. In contrast, FNT strongly binds to PTP1B and influences its expression at the K116A site, promoting M2 polarization of THP-1 cells via downregulation of PTP1B.
Formononetin mitigates diabetic hepatic injury by fostering M2 macrophage polarization via the PTP1B/STAT6 axis.
芒柄花素（FNT）是一种具有抗炎特性的异黄酮，已被证明可降低 2 型糖尿病（T2DM）的胰岛素抵抗。然而，其在糖尿病肝损伤中的作用和潜在机制在很大程度上仍未得到探索。
我们通过高脂饮食喂养，再注射链脲佐菌素，建立了 T2DM 诱导的肝损伤小鼠模型。然后用 FNT 处理这些小鼠，并评估其肝功能。使用流式细胞术、RT-qPCR 和 Western blot 评估 FNT 处理的 T2DM 小鼠或人 THP-1 细胞中的巨噬细胞标志物。分析小鼠肝组织和 THP-1 细胞中 PTP1B 和 STAT6 的表达。分子对接预测了 PTP1B 和 STAT6 之间的相互作用，通过共免疫沉淀（Co-IP）和 phos-tag 分析进行了验证。微尺度热泳（MST）评估了 FNT 与 PTP1B 的结合亲和力。
FNT 治疗显著改善了 T2DM 小鼠的血糖水平、肝细胞凋亡、炎症反应和肝功能障碍。此外，FNT 促进了 T2DM 小鼠和高糖（HG）诱导的 THP-1 衍生巨噬细胞中的 M2 巨噬细胞极化。在 T2DM 小鼠中失调的 PTP1B/STAT6 轴被 FNT 治疗所纠正，这拮抗了 T2DM 诱导的 PTP1B 上调和磷酸化 STAT6 下调。分子对接和随后的分析表明，PTP1B 结合并使 STAT6 在 S325A 位点去磷酸化。相反，FNT 强烈结合 PTP1B 并影响其在 K116A 位点的表达，通过下调 PTP1B 促进 THP-1 细胞的 M2 极化。
芒柄花素通过 PTP1B/STAT6 轴促进 M2 巨噬细胞极化来减轻糖尿病肝损伤。
