大黄多糖抑制脂多糖引起的TLR-4/NF-κB通路活化

Rheum Tanguticum Polysaccharides Suppress Lipopolysaccharide Induced Activation of TLR-4/ NF-κB Pathway

目的:探讨唐古特大黄多糖(Rheum tanguticum Polysaccharid,RTP)对脂多糖(Lipopolysaccharide,LPS)刺激上调人结肠癌细胞HT-29中TLR-4/NF-κB通路活性的影响及其机制。方法:将HT-29细胞分为对照组,LPS处理组(1μg/mL,作用30 min,1 h),RTP(1mg/mL,提前LPS 30 min给予)+LPS处理组(1μg/mL,分别作用30 min,1 h),采用免疫荧光法观察NF-κB的细胞分布情况;Western Blot法检测HT-29细胞中IκB-α,磷酸化IκB-α的蛋白变化,以及细胞膜上TLR-4的水平。结果:RTP可抑制LPS刺激引起的HT-29细胞的NF-κB核转位;可有效抑制IκB-α降解及IκB-α的磷酸化;可下调细胞膜上TLR-4的表达。结论:RTP可能通过抑制LPS刺激引起的TLR-4向细胞膜分布,从而抑制了NF-κB信号通路的活化。

Objective： To investigate the effect of rheum tanguticum polysaccharides （RTP） on the activity of TLR-4/NF-κB pathway and the possible mechanisms in lipopolysaccharide （LPS） treated human colon cancer cells HT-29. Methods： HT-29 cells were divided into control group, LPS-treated groups （1 μg/mL, added for 30 min, and 1 h）, RTP （1mg/mL, cells were pretreated with RTP for 30 min） and LPS-treated group （1μg/mL, added for 30 min, and 1 h）. Then, the distribution of NF-κB in cells was observed by immunofluorescence; the expression of IκB-α, phosphorylated IκB-α, as well as TLR-4 in the cell membrane, was detected using western blot. Results： RTP could inhibit LPS-stimulated nuclear translocation of NF-κB, degradation of IκB-α, phosphorylation of IKB-α, and reduce TLR-4 expression in membrane. Conclusion： RTP may suppress the activation of NF-κB signaling pathway through inhibition of LPS-stimulated TLR-4 distribution to cell membrane.