Xin yixue (Jun 2024)

Effect of <i>Shewanella algae</i> on the incidence and progression of colorectal adenoma and immune microenvironment in mice

  • XU Weiwei, YANG Liusi, XU Jing, ZHOU Youlian, WANG Hong

DOI
https://doi.org/10.3969/j.issn.0253-9802.2024.06.004
Journal volume & issue
Vol. 55, no. 6
pp. 421 – 429

Abstract

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Objective To investigate the effect of Shewanella algae （S.algae） on the occurrence and development of colorectal adenoma and its regulatory effect on the immune microenvironment in mice. Methods Twenty-four mice were divided into three groups： control group， azoxymethane （AOM）/ dextran sodium sulfate （DSS） group， AOM/DSS+S.algae group. The survival status and colorectal adenoma of mice were compared among three groups. Colorectal tissues in the AOM/DSS group and AOM/DSS+S.algae group were collected for high-throughput RNA-seq. Gene set enrichment analysis （GSEA）and cell-type identification by estimating relative subsets of RNA transcripts （CIBERSORT） were used to analyze the changes of immune-related pathways， immune cells and immune factors. Results Compared with the AOM/DSS group， the body weight （P < 0.05） and survival rate were decreased， the hematochezia was aggravated， the survival status was worsened，the colorectal length was shortened （all P < 0.05）， and the average number and size of adenomas were significantly increased （both P < 0.05） in the AOM/DSS+S.algae group. Compared with the AOM/DSS group， the inflammatory responses were significantly enhanced in AOM/DSS+S.algae group （P < 0.05）. The production of pro-inflammatory cytokines including interleukin （IL）-2， IL-6， IL-12， IL-17， interferon （IFN）， tumor necrosis factor （TNF） （all P < 0.05） and IL-1β showed an upward trend in the AOM/DSS+S.algae group， while the production of anti-inflammatory cytokines including IL-4， IL-10， IL-13 （all P < 0.05） and transforming growth factor β showed an inhibitory trend. Both naive B cells and plasma cells （both P < 0.05） were increased in AOM/DSS+S.algae group， and the nuclear factor -κB （NF-κB） signaling pathway was activated. Conclusion S.algae may form a tumor-promoting immune microenvironment by activating immune signals， such as activation of B cells and activation of the NF-κB pathway， and then promote the development of colorectal adenoma.

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