叶酸对低氧诱导THP-1细胞产生炎症介质的影响

Effect of folic acid on hypoxia-induced expression of inflammatory factors in THP-1 cells

目的探讨叶酸对低氧诱导人单核细胞系THP-1细胞产生炎症介质的影响及对核因子-κB的效应。方法采用不同叶酸浓度（0.4μg/m L,4μg/m L和40μg/m L）预处理细胞30min,再在1%O_2条件下培养细胞24h诱导低氧损伤,收集细胞以及培养上清。通过MTT法检测不同浓度叶酸对细胞活性的影响;ELISA法和实时荧光定量PCR分别检测细胞炎性介质（IL-1β和IL-8）的蛋白和m RNA表达水平;Western blot测定细胞NF-κB p65的蛋白表达。结果0.4～40μg/m L浓度叶酸对THP-1细胞的活性没有影响（P〉0.05）;叶酸能降低低氧所致THP-1细胞产生炎症介质IL-1β和IL-8蛋白以及m RNA的高表达（P〈0.05）,同时下调NF-κB p65蛋白表达（P〈0.05）,并呈现剂量反应关系。结论叶酸能够缓解低氧所引起的细胞炎症反应,其作用可能与抑制THP-1细胞NF-κB通路的激活及其炎症介质的释放相关。

Objective To study the effects of folic acid on hypoxia-mediated expression of inflammatory factors and NF-κB in human mononuclear cell line,THP-1,in vitro. Methods Human monocyte cell line,THP-1 cells,were pretreated withfolic acid at different concentrations,including 0.4 μg/m L,4 μg/m L,and 40 μg/m L for 30 min followed by a 24 h incubationwith 1% O2 to induce hypoxic injury. The cells and culture supernatant were harvested. MTT-based colorimetry was used toassess viability of THP- 1 cells treated with folic acid at different concentrations. Protein levels and m RNA expression ofinterleukin-1 beta（IL-1β）and interleukin-8（IL-8）were evaluated by ELISA and q RT-PCR respectively. The expressionof nuclear factor κB（NF-κB）was evaluated by western blot. Results Effect of folic acid on viability of THP-1 cells wasnegligible at any of the concentrations studied（P〉0.05）. Folic acid significantly reduced hypoxia-induced production andgene expression of IL-1β and IL-8（P〈0.05）,and markedly attenuated hypoxia-induced up-regulation of NF-κB（P〈0.05）in a dose-dependent manner. Conclusion Folic acid inhibits the inflammatory response of THP-1 cells to hypoxia,whichmay be resulted from inhibition of NF-κB pathways and the release of IL-1β and IL-8.