Zhang Duoduo, Zhou Xingtao, Zhang Ke, Yu Yongkang, Cui Steve W, Nie Shaoping
State Key Laboratory of Food Science and Technology, China-Canada Joint Lab of Food Science and Technology (Nanchang), Nanchang University, 235 Nanjing East Road, Nanchang, Jiangxi 330047, China.
State Key Laboratory of Food Science and Technology, China-Canada Joint Lab of Food Science and Technology (Nanchang), Nanchang University, 235 Nanjing East Road, Nanchang, Jiangxi 330047, China.
Int J Biol Macromol. 2023 Apr 30;235:123803. doi: 10.1016/j.ijbiomac.2023.123803. Epub 2023 Feb 24.
Impairment of intestinal epithelium barrier is a hallmark of gut pathology. Cell death can compromise barrier function and impair epithelial restitution directly or indirectly in inflammatory bowel disease (IBD). Our previous work demonstrated that glucomannan from Aloe vera gel (AGP) protected mice from DSS-induced colitis, with unclear mechanism of AGP-intestinal barrier interactions. Here, AGP maintained the integrity of intestinal barrier in colitis mice. RNA-Sequencing results indicated that pathways related to anoikis (apoptosis induced by loss of cell-matrix interaction), mitochondrial function and oxidative stress were significantly altered in the process of AGP-intestinal barrier interaction. Further experiments confirmed that AGP activated Nrf2, decreased ROS levels, mitigated mitochondrial dysfunction and anoikis of colonic epithelial cells in mice. Intriguingly, AGP reversed oxidative stress and mitochondrial dysfunction induced by knockdown or inhibitor (ML385) of Nrf2 in IEC-6 cells, which indicated the essential role of Nrf2-mitochondrial axis in the intestinal protective function of AGP. In addition, AGP alleviated anoikis caused by impaired mitochondrial function. Hence, this current work indicated that AGP might maintain intestinal barrier integrity by mitigating anoikis mediated by Nrf2-mitochondria axis. These findings provide new evidence into the effect of polysaccharides maintaining intestinal barrier integrity.
肠上皮屏障受损是肠道病理学的一个标志。在炎症性肠病(IBD)中,细胞死亡会直接或间接损害屏障功能并削弱上皮修复。我们之前的研究表明,来自芦荟凝胶的葡甘露聚糖(AGP)可保护小鼠免受右旋糖酐硫酸钠(DSS)诱导的结肠炎影响,AGP与肠道屏障相互作用的机制尚不清楚。在此,AGP维持了结肠炎小鼠肠道屏障的完整性。RNA测序结果表明,在AGP与肠道屏障相互作用过程中,与失巢凋亡(因细胞 - 基质相互作用丧失诱导的凋亡)、线粒体功能和氧化应激相关的信号通路发生了显著改变。进一步实验证实,AGP激活了Nrf2,降低了活性氧水平,减轻了小鼠结肠上皮细胞的线粒体功能障碍和失巢凋亡。有趣的是,AGP逆转了Nrf2敲低或抑制剂(ML385)在IEC - 6细胞中诱导的氧化应激和线粒体功能障碍,这表明Nrf2 - 线粒体轴在AGP的肠道保护功能中起重要作用。此外,AGP减轻了由线粒体功能受损引起的失巢凋亡。因此,当前这项研究表明,AGP可能通过减轻由Nrf2 - 线粒体轴介导的失巢凋亡来维持肠道屏障的完整性。这些发现为多糖维持肠道屏障完整性的作用提供了新证据。