Long-chain n-3 polyunsaturated fatty acids are known to have beneficial effects on intestinal health. However, the underling mechanisms are largely unknown. The present study was conducted to investigate whether docosahexaenoic acid (DHA) attenuates TNF-α-induced intestinal cell injury and barrier dysfunction by modulating necroptosis signalling. Intestinal porcine epithelial cell line 1 was cultured with or without 12.5 µg/ml DHA, followed by exposure to 50 ng/ml TNF-α for indicated time periods. DHA restored cell viability and cell number triggered by TNF-α. DHA also improved barrier function, which was indicated by increased trans-epithelial electrical resistance, decreased FD4 flux and increased membrane localisation of zonula occludins (ZO-1) and claudin-1. Moreover, DHA suppressed cell necrosis in TNF-α-challenged cells, as shown in the IncuCyte ZOOM™ live cell imaging system and transmission electron microscopy. In addition, DHA decreased protein expression of TNF receptor, receptor interacting protein kinase 1, RIP3 and phosphorylation of mixed lineage kinase-like protein, phosphoglycerate mutase family 5, dynamin-related protein 1 and high mobility group box-1 protein. Furthermore, DHA suppressed protein expression of caspase-3 and caspase-8. Collectively, these results indicate that DHA is capable of alleviating TNF-α-induced cell injury and barrier dysfunction by suppressing the necroptosis signalling pathway.

长链n-3 多不饱和脂肪酸已知对肠道健康有益。然而，底层机制在很大程度上是未知的。本研究旨在研究二十二碳六烯酸 (DHA) 是否通过调节坏死性凋亡信号来减轻 TNF-α 诱导的肠细胞损伤和屏障功能障碍。肠道猪上皮细胞系 1 在有或没有 12.5 µg/ml DHA 的情况下进行培养，然后在指定的时间段内暴露于 50 ng/ml TNF-α。DHA 恢复了由 TNF-α 触发的细胞活力和细胞数量。DHA 还改善了屏障功能，这表现为增加的跨上皮电阻、降低 FD4 通量和增加封闭小带 (ZO-1) 和 claudin-1 的膜定位。此外，DHA 抑制了 TNF-α 攻击细胞中的细胞坏死，如 IncuCyte ZOOM™ 活细胞成像系统和透射电子显微镜所示。此外，DHA 降低了 TNF 受体、受体相互作用蛋白激酶 1、RIP3 的蛋白表达以及混合谱系激酶样蛋白、磷酸甘油酸变位酶家族 5、动力蛋白相关蛋白 1 和高迁移率族 box-1 蛋白的磷酸化。此外，DHA 抑制了 caspase-3 和 caspase-8 的蛋白质表达。总的来说，这些结果表明 DHA 能够通过抑制坏死性凋亡信号通路来减轻 TNF-α 诱导的细胞损伤和屏障功能障碍。磷酸甘油酸变位酶家族 5、动力蛋白相关蛋白 1 和高迁移率族 box-1 蛋白。此外，DHA 抑制了 caspase-3 和 caspase-8 的蛋白质表达。总的来说，这些结果表明 DHA 能够通过抑制坏死性凋亡信号通路来减轻 TNF-α 诱导的细胞损伤和屏障功能障碍。磷酸甘油酸变位酶家族 5、动力蛋白相关蛋白 1 和高迁移率族 box-1 蛋白。此外，DHA 抑制了 caspase-3 和 caspase-8 的蛋白质表达。总的来说，这些结果表明 DHA 能够通过抑制坏死性凋亡信号通路来减轻 TNF-α 诱导的细胞损伤和屏障功能障碍。