南方医科大学学报 ›› 2025, Vol. 45 ›› Issue (3): 577-586.doi: 10.12122/j.issn.1673-4254.2025.03.15

• • 上一篇    

菊淀粉型巴戟天寡糖降低肺炎链球菌脑膜炎小鼠的症状评分和死亡率

李泽涵1(), 梁萌2, 韩根成2, 张学武1()   

  1. 1.延边大学医学院,吉林 延吉 133002
    2.军事科学院军事医学研究院,北京 100850
  • 收稿日期:2024-09-10 出版日期:2025-03-20 发布日期:2025-03-28
  • 通讯作者: 张学武 E-mail:13691216793@163.com;zhangxuewu@ybu.edu.cn
  • 作者简介:李泽涵,在读本科生,E-mail: 13691216793@163.com
  • 基金资助:
    国家自然科学基金(82171753)

Therapeutic effects of inulin-type oligosaccharides of Morinda officinalis on Streptococcus pneumoniae meningitis in mice

Zehan LI1(), Meng LIANG2, Gencheng HAN2, Xuewu ZHANG1()   

  1. 1.College of Medicine, Yanbian University, Yanji 133002, China
    2.Academy of Military Medical Sciences, Academy of Military Sciences, Beijing 100850, China
  • Received:2024-09-10 Online:2025-03-20 Published:2025-03-28
  • Contact: Xuewu ZHANG E-mail:13691216793@163.com;zhangxuewu@ybu.edu.cn
  • Supported by:
    National Natural Science Foundation of China(82171753)

摘要:

目的 探究菊淀粉型巴戟天寡糖(IOMO)对小鼠肺炎链球菌脑膜炎(SPM)的治疗作用及可能的作用机制。 方法 将120只雄性C57BL/6J小鼠随机分为假手术组、SPM+生理盐水(Saline)组、SPM+IOMO 25 mg/kg剂量组、SPM+IOMO 50 mg/kg剂量组,n=30。从造模当天起(0 d),SPM+Saline组和SPM+IOMO组小鼠分别灌胃生理盐水或IOMO 25 mg/kg、50 mg/kg进行干预,持续7 d,记录症状评分和死亡情况;采用脑组织HE染色和尼氏染色评价病理状态和神经元损伤情况,qRT-PCR检测皮质中炎症相关分子mRNA水平,干湿重法测脑含水量和伊文思蓝染色评价脑水肿程度和血脑屏障通透性,Western blotting检测皮质中BBB相关蛋白水平,流式细胞分析检测浸润淋巴细胞IFN-γ水平;SPM造模后21 d采用旷场实验和新物体识别实验评价小鼠学习记忆功能。 结果 灌胃给予IOMO 50 mg/kg(1次/d,连续7 d)可降低SPM小鼠的症状评分和死亡率(P<0.05),缓解脑组织病理损伤,降低皮质炎症相关分子(IL-6、TNF-α、IL-1β、IL-18、IFN-γ、iNOS、NLRP3、ASC、Caspase-1、GSDMD)mRNA水平(P<0.05); IOMO可以降低SPM小鼠脑含水量和伊文思蓝渗透量(P<0.05);IOMO可以上调脑皮质血管内皮钙黏蛋白VE-Cadherin和闭合蛋白Occludin水平、下调水通道蛋白AQP4和BBB损伤的关键调控因子iNOS、IFN-γ水平(P<0.05);建模21d后,与SPM + Saline组小鼠相比,IOMO可以改善SPM小鼠学习记忆能力(P<0.05)。 结论 首次发现IOMO可降低SPM小鼠的症状评分和死亡率,并改善其学习记忆能力,其作用机制可能与IOMO抑制过度炎症反应并保护血脑屏障有关。

关键词: 菊淀粉型巴戟天寡糖, 脑膜炎, 肺炎链球菌, 血脑屏障, 干扰素-γ

Abstract:

Objective To investigate the therapeutic effects of inulin-type oligosaccharides of Morinda officinalis (IOMO) in a murine model of Streptococcus pneumoniae meningitis (SPM) and explore its possible mechanisms. Methods A total of 120 male C57BL/6J mice were randomly assigned into Sham, SPM+Saline, SPM+IOMO (25 mg/kg), and SPM+IOMO (50 mg/kg) groups. After modeling, the mice received daily gavage of saline or IOMO at the indicated doses for 7 consecutive days, and the changes in symptom scores and mortality of the mice were monitored. Brain pathology and neuronal injury of the mice were assessed using HE and Nissl staining, and qRT-PCR was performed to detect mRNA levels of the inflammatory mediators. Brain edema and blood-brain barrier (BBB) permeability of the mice were evaluated by measuring brain water content and Evans blue (EB) staining; Western blotting was used to analyze the expressions of BBB-associated proteins, and flow cytometry was employed to detect IFN‑γ expression level in the infiltrating lymphocytes. Open-field test (OFT) and novel object recognition test (NORT) were conducted to assess learning and memory ability of the mice on day 21 after modeling. Results IOMO treatment at 50 mg/kg significantly reduced the symptom scores and mortality rate of SPM mice, alleviated brain damage, and downregulated mRNA levels of IL-6, TNF‑α, IL-1β, IL-18, IFN‑γ, iNOS, NLRP3, ASC, caspase-1 and GSDMD in the brain tissue. IOMO treatment also decreased brain water content and EB leakage, upregulated VE-cadherin and occludin expressions, and suppressed AQP4, iNOS, and IFN‑γ levels of the mice. IOMO-treated mice exhibited improved learning and memory compared with the saline-treated mice on day 21 after SPM modeling. Conclusion IOMO alleviates SPM symptoms, reduces mortality, and mitigates cognitive deficits in mice possibly by suppressing cerebral inflammation and protecting BBB functions.

Key words: inulin-type oligosaccharides of Morinda officinalis, meningitis, Streptococcus pneumoniae, blood-brain barrier, interferon-γ