Hypoxanthine is a checkpoint stress metabolite in colonic epithelial energy modulation and barrier function
Hypoxanthine is a checkpoint stress metabolite in colonic epithelial energy modulation and barrier function
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DOI：
10.1074/jbc.ra117.000269
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发表时间：
2018-04-20
影响因子：
4.8
通讯作者：
Colgan, Sean P.
中科院分区：
文献类型：
--
作者：
Lee, J. Scott;Wang, Ruth X.;Colgan, Sean P.
肠上皮细胞形成选择性可渗透屏障，保护结肠组织免受肠道微生物群和抗原的侵害，并介导肠道内的营养物质、液体和废物通量。上皮细胞屏障的失调与代谢能量的深刻变化相吻合，特别是在结肠中，存在于生理缺氧的能量消耗状态。然而，缺乏系统地研究肠上皮屏障发育和破坏后恢复过程中的能量通量和腺苷酸代谢的研究。在这里，为了描述屏障相关的能量通量，我们开发了一种基于高效液相色谱的分析方法来跟踪屏障发育和恢复过程中能量通量和腺苷酸代谢物的变化。培养的上皮细胞在屏障发育过程中表现出磷酸肌酸的池化和ATP的维持。edta诱导的上皮屏障破坏表明次黄嘌呤水平与屏障抗性相关。进一步的研究发现，补充次黄嘌呤可以改善屏障功能和伤口愈合，并且次黄嘌呤似乎是通过增加细胞内ATP来实现的，这可以改善细胞骨架G-到f -肌动蛋白的聚合。次黄嘌呤的补充增加了小鼠结肠中的腺苷酸能量电荷，表明有可能调节肠上皮细胞中腺苷酸能量电荷介导的代谢。此外，在小鼠结肠炎模型中的实验表明，活动性炎症期间的次黄嘌呤损失与疾病严重程度的标志物相关。总之，我们的研究结果表明，次黄嘌呤调节肠上皮细胞的能量代谢，对肠屏障功能至关重要。
Intestinal epithelial cells form a selectively permeable barrier to protect colon tissues from luminal microbiota and antigens and to mediate nutrient, fluid, and waste flux in the intestinal tract. Dysregulation of the epithelial cell barrier coincides with profound shifts in metabolic energy, especially in the colon, which exists in an energetically depleting state of physiological hypoxia. However, studies that systematically examine energy flux and adenylate metabolism during intestinal epithelial barrier development and restoration after disruption are lacking. Here, to delineate barrier-related energy flux, we developed an HPLC-based profiling method to track changes in energy flux and adenylate metabolites during barrier development and restoration. Cultured epithelia exhibited pooling of phosphocreatine and maintained ATP during barrier development. EDTA-induced epithelial barrier disruption revealed that hypoxanthine levels correlated with barrier resistance. Further studies uncovered that hypoxanthine supplementation improves barrier function and wound healing and that hypoxanthine appears to do so by increasing intracellular ATP, which improved cytoskeletal G- to F-actin polymerization. Hypoxanthine supplementation increased the adenylate energy charge in the murine colon, indicating potential to regulate adenylate energy charge-mediated metabolism in intestinal epithelial cells. Moreover, experiments in a murine colitis model disclosed that hypoxanthine loss during active inflammation correlates with markers of disease severity. In summary, our results indicate that hypoxanthine modulates energy metabolism in intestinal epithelial cells and is critical for intestinal barrier function.