上海中医药大学Wei Dou等研究人员合作发现，三七皂苷R1通过激活Wnt/β-Catenin信号转导促进结肠炎小鼠Lgr5⁺干细胞和上皮细胞新生。2024年3月15日，《中国药理学报》在线发表了这项成果。

研究人员表示，炎症性肠病（IBD）的特点是肠道屏障持续受损，炎症过度，导致肠道通透性增加。目前治疗IBD的方法主要针对炎症，而忽视了上皮修复。研究人员之前的研究报告称，三七根中的一种特征性皂甙——三七皂苷 R1（NGR1）具有通过减轻粘膜炎症来缓解急性结肠炎的治疗潜力。

研究人员测试了NGR1在DSS暴露急性损伤阶段后对粘膜屏障损伤的修复作用。DSS诱导的结肠炎小鼠口服NGR1（25、50、125 mg-kg^-1-d^-1）10天。在整个实验过程中，每天监测小鼠的体重和直肠出血量，然后将小鼠安乐死，收集结肠进行分析。研究表明，服用NGR1可剂量依赖性地改善结肠炎小鼠的粘膜炎症并增强上皮修复，表现为紧密连接蛋白的增加、粘液的产生和渗透性的降低。然后，研究人员利用RNA序列对直肠组织进行了转录组分析，发现服用NGR1能刺激肠隐窝细胞增殖，促进上皮损伤的修复；NGR1能上调肠干细胞（ISC）标志物 Lgr5、肠干细胞（ISC）分化基因以及结肠炎小鼠隐窝中的BrdU结合。

在体外NCM460人肠上皮细胞中，NGR1（100μM）可促进伤口愈合并减少细胞凋亡。在三维肠道类器官模型中，NGR1（100μM）还能增加Lgr5⁺细胞和出芽率。研究人员证明，NGR1通过激活Wnt信号通路促进了ISC的增殖和分化。同时使用Wnt抑制剂ICG-001可部分抵消NGR1对隐窝Lgr5⁺ISC、类器官出芽率和小鼠结肠炎整体改善的影响。这些结果表明，NGR1至少部分通过激活Wnt/β-Catenin信号通路，促进Lgr5⁺干细胞再生和肠道重建，从而缓解DSS诱导的小鼠结肠炎。

附：英文原文

Title: Notoginsenoside R1 promotes Lgr5+ stem cell and epithelium renovation in colitis mice via activating Wnt/β-Catenin signaling

Author: Yu, Zhi-lun, Gao, Rui-yang, Lv, Cheng, Geng, Xiao-long, Ren, Yi-jing, Zhang, Jing, Ren, Jun-yu, Wang, Hao, Ai, Fang-bin, Wang, Zi-yi, Zhang, Bei-bei, Liu, Dong-hui, Yue, Bei, Wang, Zheng-tao, Dou, Wei

Issue&Volume: 2024-03-15

Abstract: Inflammatory bowel disease (IBD) is characterized by persistent damage to the intestinal barrier and excessive inflammation, leading to increased intestinal permeability. Current treatments of IBD primarily address inflammation, neglecting epithelial repair. Our previous study has reported the therapeutic potential of notoginsenoside R1 (NGR1), a characteristic saponin from the root of Panax notoginseng, in alleviating acute colitis by reducing mucosal inflammation. In this study we investigated the reparative effects of NGR1 on mucosal barrier damage after the acute injury stage of DSS exposure. DSS-induced colitis mice were orally treated with NGR1 (25, 50, 125mg·kg1·d1) for 10 days. Body weight and rectal bleeding were daily monitored throughout the experiment, then mice were euthanized, and the colon was collected for analysis. We showed that NGR1 administration dose-dependently ameliorated mucosal inflammation and enhanced epithelial repair evidenced by increased tight junction proteins, mucus production and reduced permeability in colitis mice. We then performed transcriptomic analysis on rectal tissue using RNA-sequencing, and found NGR1 administration stimulated the proliferation of intestinal crypt cells and facilitated the repair of epithelial injury; NGR1 upregulated ISC marker Lgr5, the genes for differentiation of intestinal stem cells (ISCs), as well as BrdU incorporation in crypts of colitis mice. In NCM460 human intestinal epithelial cells in vitro, treatment with NGR1 (100μM) promoted wound healing and reduced cell apoptosis. NGR1 (100μM) also increased Lgr5+ cells and budding rates in a 3D intestinal organoid model. We demonstrated that NGR1 promoted ISC proliferation and differentiation through activation of the Wnt signaling pathway. Co-treatment with Wnt inhibitor ICG-001 partially counteracted the effects of NGR1 on crypt Lgr5+ ISCs, organoid budding rates, and overall mice colitis improvement. These results suggest that NGR1 alleviates DSS-induced colitis in mice by promoting the regeneration of Lgr5+ stem cells and intestinal reconstruction, at least partially via activation of the Wnt/β-Catenin signaling pathway.

DOI: 10.1038/s41401-024-01250-7

Source: https://www.nature.com/articles/s41401-024-01250-7