赤灵芝多糖对ETEC所致肠炎的影响及机制研究
he impact and mechanisms of Ganoderma lucidum polysaccharide on ETEC-induced enteritis
目的 本实验旨在研究赤灵芝多糖对产肠毒素型大肠杆菌（ETEC）诱导小鼠肠炎的作用效果及机制。方法 选用24只6至8周龄雄性SPF级昆明小鼠。利用ETEC菌液腹腔注射诱导建立小鼠肠炎模型。随机平均分为为正常组、ETEC感染组、ETEC感染+赤灵芝多糖高剂量组，ETEC感染+赤灵芝多糖低剂量组。通过HE染色法观察小鼠小肠组织病理变化情况，了解小鼠组织的病理变化。通过WB法检测各组小鼠小肠组织中C反应蛋白(CRP)、肿瘤坏死因子-α(TNF-α)和白细胞介素-6(IL-6)蛋白的表达情况和RT-qPCR技术检测各组小鼠小肠组织中Toll-样受体4(TLR4)、核因子kappaB p65亚基(NF-κB p65)、髓样分化因子88(MyD88)mRNA的表达水平，探查赤灵芝多糖通过TLR4/NF-κB信号通路对ETEC诱导的小鼠肠道炎症的调控作用。结果 与正常组比较，ETEC感染组小鼠出现精神萎靡，食欲减弱，小肠绒毛破损，组织中可发现大量的炎性浸润，DAI评分呈上升趋势（P<0.05），小鼠小肠组织中TLR4、NF-κBp65、MyD88 mRNA的相对表达量和CRP、TNF-α、IL-6的蛋白表达水平显著增高（P<0.01）。与ETEC感染组比较，不同剂量组中小鼠精神状态和食欲有所改善，小鼠小肠组织中TLR4、NF-κBp65、MyD88的mRNA相对表达量均显著降低（P<0.01）。高剂量组中小鼠小肠组织CRP、TNF-α、IL-6蛋白表达水平显著降低（P<0.01），低剂量组降低程度无显著性（P>0.05）。相比于低剂量组，高剂量组小鼠小肠组织TLR4、MyD88 mRNA的相对表达量和IL-6蛋白表达水平均均显著降低（P<0.01或P<0.05）。结论 赤灵芝多糖可以有效缓解ETEC诱导的小鼠肠道的炎症，且可能通过调控TLR4/NF-κB信号通路发挥其抗炎作用，其作用效果可能与其浓度成正比关系。
Objective The aim is to study the effect and mechanism of polysaccharide on enterotoxigenic E. coli (ETEC) induced enteritis in mice. Methods Twenty-four 6-to 8-week-old male SPF Kunming mice were selected. A mouse enteritis model was induced by intraperitoneal injection of ETEC bacterial suspension. They were randomly divided into four groups: normal group, ETEC infection group, ETEC infection+high-dose Ganoderma lucidum polysaccharide group, and ETEC infection+low-dose Ganoderma lucidum polysaccharide group. Histopathological changes in mouse small intestine tissues were observed using HE staining to understand the pathological changes in mouse tissues. The expression of C-reactive protein (CRP), tumor necrosis factor-alpha (TNF-α), and interleukin-6 (IL-6) proteins in mouse small intestine tissues was detected by WB method, and the expression levels of Toll-like receptor 4 (TLR4), nuclear factor kappa B p65 subunit (NF-κB p65), and myeloid differentiation factor 88 (MyD88) mRNA in mouse small intestine tissues were detected by RT-qPCR technique to explore the regulatory effect of Ganoderma lucidum polysaccharide on ETEC-induced mouse intestinal inflammation through the TLR4/NF-κB signaling pathway. Results Compared with the control group, mice infected with ETEC showed lethargy, reduced appetite, damaged intestinal villi, significant inflammatory infiltration in tissues, and an increasing trend in DAI scores (P<0.05). The relative expression levels of TLR4, NF-κBp65, and MyD88 mRNA, as well as the protein expression levels of CRP, TNF-α, and IL-6 in the small intestine tissues of mice, were significantly increased (P<0.01).Compared with the ETEC-infected group, mice in the different dosage groups showed improvements in mental status and appetite. The relative expression levels of TLR4, NF-κB p65, and MyD88 mRNA in the small intestine tissues of mice were significantly decreased in all dosage groups (P<0.01). In the high-dose group, the protein expression levels of CRP, TNF-α, and IL-6 in the small intestine tissues of mice were significantly decreased (P<0.01), while the decrease in the low-dose group was not significant (P>0.05). Compared with the low-dose group, the high-dose group showed significant decreases in the relative expression levels of TLR4 and MyD88 mRNA, as well as in the protein expression level of IL-6 in the small intestine tissues of mice (P<0.01 or P<0.05). Conclusion Ganoderma lucidum polysaccharide can effectively relieve the intestinal inflammation induced by ETEC, and may exert its anti-inflammatory effect through regulating TLR4/NF-κB signaling pathway, which may be proportional to its concentration
邢栋、侯娟、谭妃彤、黄柯翔、肖如雁、潘堂鑫、贾薇
医药卫生理论基础医学药学
灵芝多糖ETEC炎症因子肠炎TLR4/NF-κB
Ganoderma lucidum polysaccharideETECinflammatory factorenteritisLR4/NF-κB
邢栋,侯娟,谭妃彤,黄柯翔,肖如雁,潘堂鑫,贾薇.赤灵芝多糖对ETEC所致肠炎的影响及机制研究[EB/OL].(2024-06-16)[2025-04-28].https://www.biomedrxiv.org.cn/article/doi/bmr.202410.00010.点此复制
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