Kawasaki disease is an immune-mediated acute, systemic vasculitis and is the leading cause of acquired heart disease in children in the developed world. Bifidobacterium (BIF) is one of the dominant bacteria in the intestines of humans and many mammals and is able to adjust the intestinal flora disorder. The Caco-2 cell monolayers were treated with tumor necrosis factor-α (TNF-α) at 10 ng/ml for 24 h to induce the destruction of intestinal mucosal barrier system. Cells viability was detected through Cell Counting Kit-8 assay. Cell apoptosis was measured by flow cytometry and the expression of apoptosis related proteins was also detected through Western blot. The level of pro-inflammatory cytokines interleukin-6 (IL-6) and IL-8 was detected through ELISA, Western blot and qRT-PCR, respectively. Transepithelial electrical resistance (TEER) assay was conducted to value the barrier function of intestinal mucosa. Cell autophagy and NF-κB and p38MAPK pathways associated proteins were examined through Western blot. In the absence of TNF-α treatment, cell viability and apoptosis showed no significant change. TNF-α decreased cell viability and increased cell apoptosis and BIF treatment mitigated the TNF-α-induced change. Then, we found that BIF treatment effectively suppressed TNF-α-induced overexpression of IL-6 and IL-8. Besides, the results of TEER assay showed that barrier function of intestinal mucosa which was destroyed by TNF-α was effectively recovered by BIF treatment. In addition, TNF-α induced autophagy was also suppressed by BIF. Moreover, TNF-α activated NF-κB and p38MAPK signal pathways were also blocked by BIF, SN50 and SB203580. Our present study reveals that BIF plays a protective role in TNF-α-induced inflammatory response in Caco-2 cells through NF-κB and p38MAPK pathways.

中文翻译：

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双歧杆菌通过 NF-κB 和 p38MAPK 途径在 TNF-α 诱导的 Caco-2 细胞炎症反应中发挥保护作用。


川崎病是一种免疫介导的急性系统性血管炎，是发达国家儿童获得性心脏病的主要原因。双歧杆菌（BIF）是人类和许多哺乳动物肠道中的优势菌之一，能够调节肠道菌群紊乱。用10 ng/ml的肿瘤坏死因子-α（TNF-α）处理Caco-2单层细胞24小时，以诱导肠粘膜屏障系统的破坏。通过Cell Counting Kit-8 检测细胞活力。采用流式细胞仪检测细胞凋亡情况，并通过Western blot检测凋亡相关蛋白的表达。分别通过ELISA、Western blot和qRT-PCR检测促炎细胞因子白介素6（IL-6）和IL-8的水平。进行跨上皮电阻（TEER）测定以评价肠粘膜的屏障功能。通过蛋白质印迹检查细胞自噬以及 NF-κB 和 p38MAPK 通路相关蛋白。在没有TNF-α处理的情况下，细胞活力和细胞凋亡没有表现出显着变化。 TNF-α 降低细胞活力并增加细胞凋亡，BIF 治疗减轻 TNF-α 诱导的变化。然后，我们发现 BIF 治疗有效抑制 TNF-α 诱导的 IL-6 和 IL-8 过度表达。此外，TEER测定结果表明，被TNF-α破坏的肠粘膜屏障功能通过BIF治疗得到有效恢复。此外，BIF 还可抑制 TNF-α 诱导的自噬。此外，TNF-α激活的NF-κB和p38MAPK信号通路也被BIF、SN50和SB203580阻断。 我们目前的研究表明，BIF 通过 NF-κB 和 p38MAPK 途径在 Caco-2 细胞中 TNF-α 诱导的炎症反应中发挥保护作用。