普雷沃氏菌对肠道菌群失调所致小鼠子宫组织损伤的保护作用

Protective effect of Prevotella against uterine tissue damage induced by gut microbiota dysbiosis in mice

摘要:

背景 子宫组织损伤是导致动物不孕的常见原因之一，而肠道菌群与多种疾病的发生和发展密切相关。目的 研究肠道菌群与小鼠子宫之间的相互作用机制。方法 以小鼠为研究模型，通过建立小鼠肠道菌群失调模型及肠道菌群移植模型，探究肠道菌群失调与小鼠子宫组织损伤的关联性，以及通过16S rRNA基因测序分析肠道菌群中对小鼠子宫组织损伤具有正向调控的菌种。结果 相较于正常小鼠，肠道菌群失调小鼠子宫组织中炎症介质(TNF-α, IL-1β, IL-10)的表达水平显著上调，而在移植正常小鼠粪便后其子宫组织中TNF-α和IL-1β的表达水平发生显著下调。此外，通过对子宫形态学观察及苏木精-伊红(hematoxylin-eosin, HE)染色分析，发现肠道菌群失调小鼠子宫组织的损伤情况显著高于正常小鼠和肠道菌群移植小鼠的子宫组织。相较于正常小鼠和肠道菌群移植小鼠的子宫组织，肠道菌群失调小鼠子宫组织中中性粒细胞(Ly-6G)和巨噬细胞(F4/80)的阳性信号水平显著升高，而紧密连接蛋白闭锁小带蛋白-1 (zonula occludens-1, ZO-1)阳性信号水平显著降低。对小鼠粪便进行16S rRNA基因测序，在科和种的水平上分析发现肠道菌群失调小鼠粪便中普雷沃氏菌科(Prevotellaceae)和Prevotellaceae_UCG-001的相对丰度显著低于正常小鼠和肠道菌群移植小鼠。普雷沃氏菌(Prevotella sp.)对肠道菌群失调所致的小鼠子宫组织损伤具有治疗作用，具体表现为普雷沃氏菌治疗后小鼠子宫组织中TNF-α和IL-1β的表达水平显著下调，并且IL-10的表达水平显著上调。此外，普雷沃氏菌治疗可降低小鼠子宫组织中损伤相关蛋白HMGB1和HABP2的表达。普雷沃氏菌治疗后中性粒细胞(Ly-6G)和巨噬细胞(F4/80)的阳性信号水平显著下调，而ZO-1阳性信号水平显著上调。结论 肠道菌群失调与小鼠子宫组织损伤之间存在紧密关系，并且肠道菌群中普雷沃氏菌在其中发挥重要的调节作用。此外普雷沃氏菌对肠道菌群失调所致的小鼠子宫内膜炎具有治疗作用。该研究为未来防治子宫组织损伤相关疾病的防治提供了新的思路和依据。

Abstract:

Background Uterine tissue damage is one of the common causes of infertility in animals, and gut microbiota is closely related to the occurrence and development of various diseases.Objective To study the interaction mechanism between gut microbiota and the uterus in mice.Methods We established mouse models of gut microbiota dysbiosis and fecal microbiota transplantation to investigate the relationship between gut microbiota dysbiosis and uterine tissue damage. Subsequently, we employed 16S rRNA gene sequencing to analyze the bacterial species positively associated with uterine tissue damage.Results Compared with normal mice, the mouse model of gut microbiota dysbiosis showed significantly upregulated expression levels of inflammatory mediators (TNF-α, IL-1β, and IL-10), while transplantation of normal mouse feces significantly downregulated the expression levels of TNF-α and IL-1β in the uterine tissue. Histological observation and hematoxylin-eosin (HE) staining results revealed that the uterine tissue damage in the mouse model of gut microbiota dysbiosis was significantly severer than that in normal mice and the mouse model of fecal microbiota transplantation. Compared with normal mice and the mouse model of gut microbiota transplantation, the mouse model of gut microbiota dysbiosis exhibited significantly elevated positive signals of neutrophils (Ly-6G) and macrophages (F4/80) and a declined positive signal level of tight junction protein Zonula occludens-1 (ZO-1). The 16S rRNA gene sequencing was performed on the feces of mice. At the family and species levels, it was found that the relative abundance of Prevotellaceae and Prevotellaceae_UCG-001 in the feces of mice with gut microbiota dysbiosis was significantly lower than that in normal mice and mice with intestinal flora transplantation. Prevotella exhibited a therapeutic effect on uterine tissue damage induced by gut microbiota dysbiosis, as evidenced by significant reductions in TNF-α and IL-1β expression levels and a significant increase in the IL-10 expression level in the uterine tissue after Prevotella treatment. Additionally, Prevotella treatment downregulated the expression levels of damage-related proteins HMGB1 and HABP2 in the uterine tissue. After treatment, the positive signals of neutrophils (Ly-6G) and macrophages (F4/80) in the uterine tissue were significantly downregulated, while the positive signal level of tight junction protein ZO-1 was significantly upregulated.Conclusion There is a close relationship between gut microbiota dysbiosis and uterine tissue damage in mice, with Prevotella playing a crucial regulatory role. Furthermore, Prevotella exhibits a therapeutic effect on endometritis induced by gut microbiota dysbiosis in mice. This study provides new insights and evidence for the prevention and treatment of diseases associated with uterine tissue damage.