Tea polyphenols protect bovine mammary epithelial cells from hydrogen peroxide-induced oxidative damage in vitro by activating NFE2L2/HMOX1 pathways
Tea polyphenols protect bovine mammary epithelial cells from hydrogen peroxide-induced oxidative damage in vitro by activating NFE2L2/HMOX1 pathways
复制标题
茶多酚通过激活 NFE2L2/HMOX1 通路保护牛乳腺上皮细胞免受过氧化氢诱导的体外氧化损伤
DOI：
10.3168/jds.2018-15047
复制
发表时间：
2019-02-01
影响因子：
3.5
通讯作者：
Loor, J. J.
中科院分区：
文献类型：
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作者：
Ma, Y. F.;Zhao, L.;Loor, J. J.
围产期奶牛可能会受到改变细胞内的还原-氧化（氧化还原）平衡，由于高代谢率和分娩前后发生的生理适应。这些条件可能会导致氧化损伤。在非反刍动物中，已经确定核因子红细胞2样2（NFE 2L 2）是通过诱导针对氧化应激（OS）的适应性反应来维持细胞氧化还原平衡的关键转录因子，否则氧化应激可能导致不受控制的炎症。茶多酚是绿色茶中的主要多酚类物质，具有清除自由基的作用，对牛乳腺上皮细胞具有保护作用。我们使用NFE 2L 2短干扰RNA（siRNA）下调培养的BMEC中NFE 2L 2的表达，以研究TP是否可以通过激活NFE 2L 2/血红素加氧酶-1（HMOX 1）通路来抑制H2 O2诱导的OS。将分离的BMEC暴露于H2 O2（600 μ M）6 h以诱导OS。通过预处理BMEC 0、2、4、6、8、12和24 h，然后用H2 O2（600 μ M）攻击6 h来评估TP的最佳剂量（0、60、80和100 μ g/mL）。用NFE 2L 2-siRNA转染BMEC 48 h，用100 μ g/mL TP预处理12 h，然后用600 μ M H2 O2攻击6 h。结果显示，H2 O2暴露后，TP的浓度为100 μ g/mL，在12小时的孵育导致更大的细胞活力，蛋白质和mRNA丰度的NFE 2L 2，和较低的细胞内活性氧（ROS）的积累。此外，转染NFE 2L 2-siRNA降低了NFE 2L 2和HMOX 1的丰度，尽管外源性TP的补充，而ROS的产生增加响应外源性H2 O2（600 μ M）。总的来说，TP对BMEC的氧化还原平衡有有益的影响，通过减少ROS的产生和增强至少部分由NFE 2L 2/HMOX 1通路控制的机制来减缓细胞OS相关的损伤。
Periparturient dairy cows are likely subject to altered intracellular reduction-oxidation (redox) balance due to the high metabolic rates and physiological adaptations occurring around parturition. Such conditions could induce oxidative damage. In nonruminants, it is well established that nuclear factor erythroid 2 like 2 (NFE2L2) is a critical transcription factor for maintaining cellular redox balance by inducing adaptive responses against oxidative stress (OS) that can otherwise lead to uncontrolled inflammation. Tea polyphenols (TP), the major polyphenolic constituents of green tea, are potent antioxidants that could exert protective effects on bovine mammary epithelial cells (BMEC) by scavenging free radicals. We used NFE2L2 short interfering RNA (siRNA) to downregulate NFE2L2 expression in cultured BMEC to investigate whether TP could inhibit H2O2 -induced OS by activating the NFE2L2/heme oxygenase-1 (HMOX1) pathway. Isolated BMEC were exposed to H2O2 (600 mu M) for 6 h to induce OS. Optimal doses of TP (0, 60, 80, and 100 mu g/mL) were evaluated by pretreatment of BMEC for 0, 2, 4, 6, 8, 12, and 24 h, followed by a H2O2 (600 mu M) challenge for 6 h. The BMEC were transfected with NFE2L2-siRNA for 48 h, pretreated with 100 mu g/mL of TP for 12 h, then challenged by 600 mu M H2O2 for 6 h. Results revealed that after H2O2 exposure a concentration of TP of 100 mu g/mL during a 12-h incubation led to greater cell viability, protein, and mRNA abundance of NFE2L2, and lower intracellular reactive oxygen species (ROS) accumulation. In addition, transfection with NFE2L2-siRNA decreased abundance of NFE2L2 and HMOX1 in spite of exogenous TP supplementation, whereas ROS production was increased in response to exogenous H2O2 (600 mu M). Overall, TP had beneficial effects on redox balance in BMEC, slowing down cellular OS-related injury through decreasing the production of ROS and enhancing mechanisms controlled at least in part by the NFE2L2/HMOX1 pathway.