■本研究的目的是研究葛三素(AM)对葡聚糖硫酸钠(DSS)诱导的结肠炎小鼠的影响,并阐明其保护机制。
■使用3%DSS溶液诱导结肠炎,并以25和50mg/kg的剂量进行AM的胃内给药。进行综合评估以评估结肠中的炎症反应和粘膜完整性。使用酶联免疫吸附测定(ELISA)定量炎症因子。通过RT-qPCR和流式细胞术分析肠系膜淋巴结(MLN)中T辅助细胞17(Th17)和调节性T细胞(Treg)细胞的比例。通过RT-qPCR检查与Notch和JAK2/STAT3途径相关的蛋白质,西方印迹,和免疫荧光。此外,体外研究了AM对Treg和Th17细胞分化的影响。
■AM预处理可显着减轻小鼠的结肠炎症,体重减轻证明了这一点,较短的结肠长度,较低的疾病活动指数(DAI)评分,髓过氧化物酶(MPO)含量降低。值得注意的是,AM预处理减弱了促炎细胞因子的产生,包括白细胞介素(IL)-1β,肿瘤坏死因子(TNF)-α,和IL-6,在DSS诱导的结肠炎小鼠中。此外,AM预处理显着增强了紧密连接蛋白(Occludin和ZO-1)的表达,从而保持肠屏障功能。此外,我们观察到AM给药降低Th17细胞的比例,同时增加结肠Treg细胞的频率,从而在体内和体外调节Th17/Treg平衡。此外,在AM治疗组中,Notch-1、Jagged1、δ样4(DLL4)的表达,与DSS组相比,结肠组织中的磷酸-janus激酶2(p-JAK2)/JAK2和p-信号转导子和转录激活因子3(STAT3)/STAT3减少。值得注意的是,AM对结肠炎小鼠的治疗作用被Notch激活剂阻断.
■这些发现强调了AM通过调节Notch和JAK2/STAT3信号通路重新平衡Th17/Treg细胞稳态,在减轻DSS诱导的结肠炎小鼠症状和病理损伤中的有效性。这些对AM作用机制的见解为新的治疗策略提供了潜在的途径。
UNASSIGNED: The objective of this study was to investigate the effects of agrimonolide (AM) on mice with dextran sulfate sodium (DSS)-induced colitis and elucidate its protective mechanisms.
UNASSIGNED: A 3 % DSS solution was used to induce colitis, and intragastric administration of AM at doses of 25 and 50 mg/kg was performed. A comprehensive assessment was conducted to evaluate inflammatory responses and mucosal integrity in the colon. Inflammatory factors were quantified using enzyme-linked immunosorbent assay (ELISA). The proportions of T helper cell 17 (Th17) and regulatory T cells (Treg) cells in mesenteric lymph nodes (MLNs) was analyzed through RT-qPCR and flow cytometry. Proteins associated with the
Notch and JAK2/STAT3 pathways were examined via RT-qPCR, western blotting, and immunofluorescence. Additionally, the impact of AM on Treg and Th17 cell differentiation was investigated in vitro.
UNASSIGNED: Pre-treatment with AM significantly alleviated colon inflammation in mice, as evidenced by reduced body weight loss, shorter colon length, lower disease activity index (DAI) score, and decreased myeloperoxidase (MPO) content. Notably, AM pre-treatment attenuated the production of pro-inflammatory cytokines, including interleukin (IL)-1β, tumor necrosis factor (TNF)-α, and IL-6, in mice with DSS-induced colitis. Additionally, AM pre-treatment significantly enhanced the expression of tight junction proteins (Occludin and ZO-1), thereby preserving gut barrier function. Moreover, we observed that AM administration decreased the ratio of Th17 cells while increasing the frequency of colonic Treg cells, thus modulating the Th17/Treg balance both in vivo and in vitro. Furthermore, in the AM-treated group, the expression of
Notch-1, Jagged1, delta like 4 (DLL4), phospho-janus kinases 2 (p-JAK2)/JAK2, and p-signal transducer and activator of transcription 3 (STAT3)/STAT3 in colonic tissue was reduced compared to the DSS group. Remarkably, the therapeutic effects of AM in colitis mice were blocked by a
Notch activator.
UNASSIGNED: These findings underscore the effectiveness of AM in alleviating symptoms and pathological damage in DSS-induced colitis mice by rebalancing Th17/Treg cell homeostasis through modulation of the
Notch and JAK2/STAT3 signaling pathways. These insights into AM\'s mechanisms of action offer potential avenues for novel therapeutic strategies.