Wang Si-Pu, Ba Ling, Lv Xin-Rui, Qi Ya-Xin, Wang Xu, Zhang Jie, Xu Xin
Department of Gastroenterology and Hepatology, Tianjin Medical University General Hospital, Tianjin, China.
Tianjin Institute of Digestive Disease, Tianjin Medical University General Hospital, Tianjin, China.
Front Microbiol. 2025 Sep 2;16:1580171. doi: 10.3389/fmicb.2025.1580171. eCollection 2025.
The regenerating gene 3γ (Reg IIIγ) protein, a key antimicrobial peptide, is essential for maintaining intestinal barrier homeostasis and host defense. Its expression is impaired in metabolic-associated fatty liver disease (MAFLD), particularly under high-fat diet (HFD) conditions, contributing to barrier dysfunction. Given evidence that probiotic-derived components can modulate Reg IIIγ, this study aimed to evaluate the effects of GG supernatant (LGGs) on Reg IIIγ expression, their impact on intestinal barrier function, and their therapeutic potential in mitigating MAFLD, while elucidating the underlying mechanisms involving the TLR2/MyD88/pSTAT3 signaling pathway.
Six-week-old C57BL/6 J mice were randomly assigned to four groups: standard diet with phosphate-buffered saline (PBS), standard diet with LGGs, high-fat diet (HFD) with PBS, and HFD with LGG. The expression of intestinal Reg IIIγ, changes in intestinal microbiota, and intestinal permeability were analyzed using quantitative PCR (qPCR) and western blot techniques. experiments involved assessing HIP/PAP expression in Caco-2 cell lines following stimulation with LGG supernatants, using qPCR and western blot. Additionally, siRNA transfection of Caco-2 cells was used to examine the MyD88/pSTAT3 signaling pathway.
HFD impaired the intestinal barrier in mice. However, oral administration of LGG significantly enhanced the expression of Reg IIIγ in the intestinal mucosa compared to control groups. This intervention notably improved intestinal barrier function, modulated the composition of intestinal microbiota, and mitigated MAFLD. Furthermore, an inverse correlation was observed between intestinal permeability and Reg IIIγ expression. , stimulation of Caco-2 cells with LGG led to a significant upregulation of HIP/PAP protein expression, mediated through the MyD88/pSTAT3 signaling pathway.
LGG supernatant enhances intestinal Reg IIIγ expression through the MyD88/pSTAT3 signaling pathway, thereby contributing to the protection of intestinal barrier function and alleviation of MAFLD.
再生基因3γ（Reg IIIγ）蛋白是一种关键的抗菌肽，对维持肠道屏障稳态和宿主防御至关重要。其表达在代谢相关脂肪性肝病（MAFLD）中受损，尤其是在高脂饮食（HFD）条件下，这会导致屏障功能障碍。鉴于有证据表明益生菌衍生成分可调节Reg IIIγ，本研究旨在评估鼠李糖乳杆菌上清液（LGGs）对Reg IIIγ表达的影响、其对肠道屏障功能的作用以及在减轻MAFLD方面的治疗潜力，同时阐明涉及TLR2/MyD88/pSTAT3信号通路的潜在机制。
将6周龄的C57BL/6 J小鼠随机分为四组：标准饮食加磷酸盐缓冲盐水（PBS）、标准饮食加LGGs、高脂饮食加PBS、高脂饮食加LGG。使用定量PCR（qPCR）和蛋白质印迹技术分析肠道Reg IIIγ的表达、肠道微生物群的变化和肠道通透性。实验包括在用LGG上清液刺激后，使用qPCR和蛋白质印迹评估Caco-2细胞系中HIP/PAP的表达。此外，使用Caco-2细胞的siRNA转染来检测MyD88/pSTAT3信号通路。
高脂饮食损害了小鼠的肠道屏障。然而，与对照组相比，口服LGG显著增强了肠道黏膜中Reg IIIγ的表达。这种干预显著改善了肠道屏障功能，调节了肠道微生物群的组成，并减轻了MAFLD。此外，观察到肠道通透性与Reg IIIγ表达之间呈负相关。在用LGG刺激Caco-2细胞后，通过MyD88/pSTAT3信号通路导致HIP/PAP蛋白表达显著上调。
LGG上清液通过MyD88/pSTAT3信号通路增强肠道Reg IIIγ表达，从而有助于保护肠道屏障功能并减轻MAFLD。
