Wang Shu, Wang Lu, Lin Junjie, Wang Mingyuan, Li Jiajia, Guo Qiong, Jiao Chunhua, Tang Nana, Ma Jingjing, Zhang Hongjie, Zhao Xiaojing
Department of Gastroenterology, The First Affiliated Hospital with Nanjing Medical University, 300 Guangzhou Road, Nanjing 210029 Jiangsu Province, China.
Department of Gastroenterology, The First Affiliated Hospital with Nanjing Medical University, 300 Guangzhou Road, Nanjing 210029 Jiangsu Province, China.
Mucosal Immunol. 2025 Aug;18(4):989-1000. doi: 10.1016/j.mucimm.2025.05.008. Epub 2025 Jun 4.
Intestinal fibrosis is one of the most threatening complications of Crohn's disease (CD). Although our previous study identified the profibrotic role of amphiregulin (AREG) in intestinal fibrosis, the underlying molecular mechanisms remain poorly understood. This study aimed to elucidate the mechanisms by which AREG mediates intestinal fibrosis. Specimens from stenotic and non-stenotic lesions in CD patients were collected, alongside normal specimens from individuals with intestinal diverticula, for the assessment of AREG levels. A dextran sulfate sodium (DSS)-induced chronic colitis model was established in wild type (WT) and Areg-knockout (Areg) mice. RNA-sequencing (RNA-seq) was performed on human intestinal fibroblasts (HIFs) to elucidate the underlying mechanisms. Additionally, the single-cell RNA-seq data of full-thickness CD, obtained from Prof. Rieder, was reanalyzed. Elevated levels of AREG were detected at stenotic sites in patients with CD. Areg colitis mice exhibited decreased intestinal fibrosis. AREG enhanced the activation and proliferation of HIFs by activating the PI3K/AKT pathway. The inhibitor of the PI3K/AKT pathway effectively suppressed AREG-induced activation and proliferation of HIFs and attenuated colitis-associated fibrosis in mice. In stricturing CD, inflammatory monocytes exhibited higher AREG levels, contributing to the activation and proliferation of intestinal fibroblasts. Adoptive transfer of Ly6c inflammatory monocytes from WT but not Areg mice exacerbated intestinal fibrosis in DSS-induced colitis mice. These findings reveal that inflammatory monocytes derived-AREG promotes intestinal fibrosis in experimental colitis and CD patients by promoting intestinal fibroblasts activation and proliferation through the PI3K/AKT pathway. Inflammatory monocytes serve as the primary source of AREG in stricturing CD, critically mediating fibroblast-related fibrotic progression in an AREG-dependent manner. Therefore, AREG, the PI3K/AKT pathway and inflammatory monocytes may serve as potential therapeutic targets for intestinal fibrosis in CD.
肠道纤维化是克罗恩病（CD）最具威胁性的并发症之一。尽管我们之前的研究确定了双调蛋白（AREG）在肠道纤维化中的促纤维化作用，但其潜在的分子机制仍知之甚少。本研究旨在阐明AREG介导肠道纤维化的机制。收集了CD患者狭窄和非狭窄病变的标本，以及肠道憩室患者的正常标本，以评估AREG水平。在野生型（WT）和Areg基因敲除（Areg -/-）小鼠中建立了葡聚糖硫酸钠（DSS）诱导的慢性结肠炎模型。对人肠道成纤维细胞（HIFs）进行RNA测序（RNA - seq）以阐明潜在机制。此外，还重新分析了从里德教授处获得的全层CD的单细胞RNA - seq数据。在CD患者的狭窄部位检测到AREG水平升高。Areg -/- 结肠炎小鼠的肠道纤维化程度降低。AREG通过激活PI3K/AKT途径增强了HIFs的活化和增殖。PI3K/AKT途径抑制剂有效地抑制了AREG诱导的HIFs活化和增殖，并减轻了小鼠结肠炎相关的纤维化。在狭窄性CD中，炎性单核细胞表现出较高的AREG水平，这有助于肠道成纤维细胞的活化和增殖。从WT小鼠而非Areg -/- 小鼠过继转移Ly6c炎性单核细胞会加剧DSS诱导的结肠炎小鼠的肠道纤维化。这些发现表明，来源于炎性单核细胞的AREG通过PI3K/AKT途径促进肠道成纤维细胞的活化和增殖，从而在实验性结肠炎和CD患者中促进肠道纤维化。炎性单核细胞是狭窄性CD中AREG的主要来源，以AREG依赖的方式关键地介导与成纤维细胞相关的纤维化进展。因此，AREG、PI3K/AKT途径和炎性单核细胞可能是CD肠道纤维化的潜在治疗靶点。
