Department of Immunology and Microbiology, School of Basic Medical Sciences, Guizhou University of Traditional Chinese Medicine, Guiyang, China.
Cengong County People's Hospital, Kaili, China.
Mediators Inflamm. 2024 Oct 18;2024:9550301. doi: 10.1155/2024/9550301. eCollection 2024.
Sepsis is defined as a life-threatening disease. Autophagy and the microbiome are increasingly connected with sepsis. The aim of this study was to investigate the protective effect of autophagy and the possible mechanisms. The septic rat model was established by cecal ligation perforation (CLP). Rapamycin (Rap), 3-methyladenine (3-MA), and chloroquine (CQ) were administered to interfere autophagy. Western blot (WB) was used to detect the expression of key proteins in autophagy. Hematoxylin and eosin (H&E) staining and enzyme-linked immunosorbent assays (ELISAs) were used to identify the effect of autophagy on various organs. 16S ribosomal RNA gene sequencing was used to analyze the changes of the gut microbiota. Rap significantly upregulated the expression of key autophagy proteins, and 3-MA reduced the relative expression compared to the CLP group. The autophagic flux showed a corresponding trend. Interestingly, the autophagy inducer significantly decreased the mortality and the lipopolysaccharide (LPS) level in serum compared with the CLP group. Autophagy activation significantly improves the inflammatory response in sepsis. Histopathological sections showed that CLP destroyed the tight junctions between ileal epithelial cells, while autophagy induction reversed the damage. The sequencing results showed that autophagy activation increased the alpha diversity and alterted the composition and structure of gut microbiota. The abundance of Proteobacteria was markedly decreased in the Rap group, whereas Bacteroidetes was notably increased compared with the CLP group. Additionally, the protective effect of autophagy further changed the biomarkers in the microbial community. The top 35 functions in each sample were analyzed to obtain 18 genes including RNA synthesis, ATP binding and transport, chromosome assignment, osmotic polysaccharide transport, transcytosis, and methylation. Autophagy is able to improve inflammation and may directly or indirectly regulate the microbiota of septic rats. Autophagy may be an important target for future clinical interventions in the treatment of sepsis.
脓毒症被定义为一种危及生命的疾病。自噬和微生物组与脓毒症的关系越来越密切。本研究旨在探讨自噬的保护作用及其可能的机制。通过盲肠结扎穿孔（CLP）建立脓毒症大鼠模型。雷帕霉素（Rap）、3-甲基腺嘌呤（3-MA）和氯喹（CQ）用于干扰自噬。Western blot（WB）用于检测自噬关键蛋白的表达。苏木精和伊红（H&E）染色和酶联免疫吸附试验（ELISA）用于鉴定自噬对各种器官的影响。16S 核糖体 RNA 基因测序用于分析肠道微生物群的变化。Rap 显著上调了自噬关键蛋白的表达，与 CLP 组相比，3-MA 降低了相对表达。自噬流表现出相应的趋势。有趣的是，与 CLP 组相比，自噬诱导剂显著降低了死亡率和血清中脂多糖（LPS）水平。自噬激活显著改善了脓毒症中的炎症反应。组织病理学切片显示 CLP 破坏了回肠上皮细胞之间的紧密连接，而自噬诱导则逆转了损伤。测序结果表明，自噬激活增加了 alpha 多样性，并改变了肠道微生物群的组成和结构。Rap 组中变形菌的丰度明显降低，而厚壁菌门的丰度明显高于 CLP 组。此外，自噬的保护作用进一步改变了微生物群落中的生物标志物。对每个样本的前 35 个功能进行分析，得到包括 RNA 合成、ATP 结合和运输、染色体分配、渗透多糖运输、转胞吞作用和甲基化在内的 18 个基因。自噬能够改善炎症，可能直接或间接调节脓毒症大鼠的微生物群。自噬可能是未来脓毒症治疗临床干预的一个重要靶点。
