Endoscopy Center, Department of Gastroenterology, Shanghai East Hospital, Tongji University School of Medicine, Shanghai, China.
Department of Gastroenterology, Changhai Hospital, Naval Medical University, Shanghai, China.
Phytomedicine. 2024 Jul 25;130:155580. doi: 10.1016/j.phymed.2024.155580. Epub 2024 Apr 2.
Macrophages exhibit different phenotypes in inflammatory bowel disease (IBD) and promote inflammation or tissue repair depending on their polarization state. Alcohol is a widely used solvent in pharmaceutical formulations, and its consumption is associated with an increased risk of colitis; however, its effects on macrophages in IBD remain poorly understood.
This study aimed to investigate the effect of alcohol on macrophages in dextran sodium sulfate (DSS)-induced colitis and understand the underlying mechanisms.
DSS-treated C57BL/6 mice were exposed to varying concentrations of alcohol, transient receptor potential vanilloid 1 (TRPV1) antagonist, and 5-aminosalicylic acid. The distal colon was resected, fixed, stained, and histologically analyzed, through hematoxylin and eosin (H&E) staining and immunofluorescence staining. Ratio [Ca]i measurements, western blotting, quantitative polymerase chain reaction, cytokine measurements, and RNA sequencing analyses were also performed. Peritoneal macrophages and RAW264.7 cells were used for in vitro experiments, and various assays were performed to evaluate cellular responses, gene expression, and signaling pathways.
Alcohol exacerbated DSS-treated mice colitis and promoted the secretion of various inflammatory cytokines from colonic macrophages. Alcohol enhances the calcium ion influx induced by lipopolysaccharide (LPS) in peritoneal macrophages, while the TRPV1 antagonist capsazepine (CPZ) inhibits LPS- and/or alcohol- induced calcium influx in macrophages. Alcohol and LPS activate the MAPK/P38, MAPK/ERK, and NF-κB signaling pathways and induce the macrophage M2b polarization, resulting in the increased expression level of inflammatory cytokines such as Tnf, Il1b, and Il10. Additionally, CPZ can inhibit the facilitatory effects of alcohol or LPS on the abovementioned pathways and inflammatory factors, reversing macrophage M2b polarization and promoting alcohol-induced colitis. The inhibition of nucleotide binding oligomerization domain containing 2 (NOD2) partially suppressed the alcohol and LPS effects on macrophages.
Alcohol exacerbates experimental colitis and induces M2b polarization of macrophage via TRPV1-MAPK/NF-κB. Our study provides new insights into the potential therapeutic targets for IBD treatment by elucidating the role of TRPV1 in alcohol-exacerbated colitis, using CPZ as a potential therapeutic option. The identification of transient receptor potential ankyrin subtype 1 (TRPA1) as a therapeutic target expands the scope of future research.
巨噬细胞在炎症性肠病（IBD）中表现出不同的表型，并根据其极化状态促进炎症或组织修复。酒精是药物制剂中广泛使用的溶剂，其消费与结肠炎风险增加有关；然而，其在 IBD 中对巨噬细胞的影响仍知之甚少。
本研究旨在探讨酒精对葡聚糖硫酸钠（DSS）诱导结肠炎中巨噬细胞的影响，并了解其潜在机制。
用不同浓度的酒精、瞬时受体电位香草酸 1（TRPV1）拮抗剂和 5-氨基水杨酸处理 DSS 处理的 C57BL/6 小鼠。切除、固定、染色并通过苏木精和伊红（H&E）染色和免疫荧光染色进行组织学分析。还进行了[Ca]i 测量、western blot、定量聚合酶链反应、细胞因子测量和 RNA 测序分析。腹腔巨噬细胞和 RAW264.7 细胞用于体外实验，并进行各种测定以评估细胞反应、基因表达和信号通路。
酒精加重 DSS 处理的小鼠结肠炎并促进结肠巨噬细胞分泌各种炎症细胞因子。酒精增强脂多糖（LPS）诱导的腹腔巨噬细胞钙离子内流，而 TRPV1 拮抗剂辣椒素（CPZ）抑制巨噬细胞中 LPS 和/或酒精诱导的钙离子内流。酒精和 LPS 激活 MAPK/P38、MAPK/ERK 和 NF-κB 信号通路，并诱导巨噬细胞 M2b 极化，导致 TNF、IL1b 和 IL10 等炎症因子的表达水平增加。此外，CPZ 可以抑制酒精或 LPS 对上述通路和炎症因子的促进作用，逆转巨噬细胞 M2b 极化并促进酒精诱导的结肠炎。核苷酸结合寡聚化结构域包含 2（NOD2）的抑制部分抑制了酒精和 LPS 对巨噬细胞的作用。
酒精通过 TRPV1-MAPK/NF-κB 加重实验性结肠炎并诱导巨噬细胞 M2b 极化。我们的研究通过阐明 TRPV1 在酒精加重结肠炎中的作用，使用 CPZ 作为潜在的治疗选择，为 IBD 治疗提供了新的治疗靶点。瞬态受体电位锚蛋白亚型 1（TRPA1）作为治疗靶点的鉴定扩展了未来研究的范围。
