ABSTRACT

Microbial dysbiosis is an established finding in patients with inflammatory bowel disease (IBD), but host-microbial interactions are poorly understood. We aimed to unravel the effect of microbiota exposure on intestinal epithelial cells. Confluent Transwell® organoid monolayers of eight UC patients and eight non-IBD controls were co-cultured for six hours with microbiota (3x10⁸ cells) of UC patients or a healthy volunteer (HV), in the presence or absence of an inflammatory cytokine mix. Transepithelial electrical resistance (TEER), fluorescein isothiocyanate (FITC) dextran measurements, and RNA sequencing were performed on epithelial cells, and 16S rRNA sequencing on microbiota samples before and after co-culture. Transcriptomic response following microbiota exposure was not different between epithelial cells from UC patients or non-IBD controls. Following UC microbiota exposure, but not HV microbiota, a strong decrease in epithelial barrier integrity was observed in both UC and HV epithelial cells by TEER and FITC dextran measurements. Exposure of inflamed epithelium to UC microbiota induced transcriptomic stress pathways including activation of EGR1, MAPK and JAK/STAT signaling, as well as AP-1 family and FOSL transcripts. Stress responses after HV microbiota stimulation were milder. We conclude that not the epithelial cell origin (UC versus non-IBD) but the microbial donor drives transcriptomic responses, as exposure to UC microbiota was sufficient to induce stress responses in all epithelial cells. Further research on therapies to restore the microbial balance, to remove the constant trigger of dysbiosis, is required.

摘要

微生物菌群失调是炎症性肠病 (IBD) 患者的既定发现，但对宿主-微生物相互作用知之甚少。我们旨在揭示微生物群暴露对肠上皮细胞的影响。将 8 名 UC 患者和 8 名非 IBD 对照的 Confluent Transwell® 类器官单层与微生物群（3x10 ⁸UC 患者或健康志愿者 (HV) 的细胞），在存在或不存在炎性细胞因子混合物的情况下。对上皮细胞进行跨上皮电阻 (TEER)、异硫氰酸荧光素 (FITC) 葡聚糖测量和 RNA 测序，并对共培养前后的微生物群样本进行 16S rRNA 测序。UC 患者或非 IBD 对照的上皮细胞在微生物群暴露后的转录组反应没有差异。在 UC 微生物群暴露后，但不是 HV 微生物群，通过 TEER 和 FITC 葡聚糖测量，在 UC 和 HV 上皮细胞中观察到上皮屏障完整性的强烈下降。炎症上皮暴露于 UC 微生物群诱导的转录组应激途径，包括激活 EGR1、MAPK 和 JAK/STAT 信号传导，以及 AP-1 家族和 FOSL 成绩单。HV 微生物群刺激后的应激反应较温和。我们得出结论，不是上皮细胞起源（UC 与非 IBD），而是微生物供体驱动转录组反应，因为暴露于 UC 微生物群足以诱导所有上皮细胞的应激反应。需要进一步研究恢复微生物平衡的疗法，以消除生态失调的持续触发因素。