乳源酪蛋白糖巨肽对NF-κB信号通路中关键蛋白的调控作用  

Regulatory Effect of Milk-Derived Casein Glycomacropeptide on Key Enzymes Involved in NF-κB Signaling Pathway

作　　者：王泳[1] 龚建苗[1] 贾彦[1] 赵培[1] 庞广昌[1] 阎亚丽[1] 陈庆森[1] WANG Yong;GONG Jianmiao;JIA Yan;ZHAO Pei;PANG Guangchang;YAN Yali;CHEN Qingsen(Tianjin Key Laboratory of Food Biotechnology, College of Biotechnology and Food Science,Tianjin University of Commerce, Tianjin 300134, China)

机构地区：[1]天津市食品生物技术重点实验室天津商业大学生物技术与食品科学学院,天津300134

出　　处：《食品科学》2017年第17期26-31,共6页Food Science

基　　金：国家自然科学基金面上项目(31071522)

摘　　要：以结肠癌细胞HT-29为细胞系,在确定乳源性酪蛋白糖巨肽(casein glycomacropeptide,CGMP)对脂多糖(lipopolysaccharides,LPS)诱导的HT-29细胞核因子-κB(nuclear factor-κB,NF-κB)亚单位p65蛋白影响的基础上,在最适作用时间条件下,利用Western blotting技术进一步检测乳源CGMP对NF-κB信号通路上关键蛋白IκBα、p-IκBα、E3RSIκB、UBC5表达水平的影响,以阐述乳源CGMP调控NF-κB信号通路中关键蛋白的作用机制。结果表明:乳源CGMP组的3种质量浓度(0.001、0.010、0.100?μg/m L)均可在一定程度上抑制LPS诱导的HT-29细胞NF-κB信号通路上IκBα蛋白的降解,0.100?μg/m L作用较为明显,与空白对照组比较有显著性差异(P<0.01)。研究明确地证实了乳源CGMP可通过抑制p-IκBα、E3RSIκB、UBC5蛋白的表达来抑制IκBα蛋白的降解,进而抑制NF-κB信号通路的激活。结论:乳源CGMP可显著降低NF-κB信号通路关键蛋白IκBα的降解,其机制是抑制了IκBα的磷酸化和泛素化,使p-IκBα和泛素化关键蛋白E3RSIκB和UBC5的表达均有所下降,进而减少了IκBα的降解,增加了IκBα-p65-p50蛋白三聚体的数量,使p65蛋白核移位效应降低,进而减少下游基因的表达。因此,研究结果科学地阐释了乳源CGMP是通过调控NF-κB信号通路发挥抗炎的作用。This study was undertaken to determine the effect of casein glycomacropeptide(CGMP)on the p65subunit of nuclear factor-κB(NF-κB)of HT-29human colon cancer cells challenged with lipopolysaccharide(LPS).Furthermore,Western blotting technology was used to detect and compared the expression levels of the key proteins involved in the NF-κB signaling pathway such as IκBα,p-IκBα,E3RSIκB and UBC5in the control group,milk-derived CGMP group and LPS group to uncover the molecular mechanism of CGMP in regulating the NF-κB signaling pathway.The results showed that all three doses of CGMP(0.001,0.010and0.100μg/mL)could suppress the degradation of IκBαin some degree,which is involved in the NF-κB signaling pathway of HT-29cells challenged with LPS and this effect was more significant at the dose of0.100μg/mL,which was significantly different when compared with the control group(P<0.01).Therefore,it was confirmed that CGMP could suppress the degradation of IκBαby repressing the expression of p-IκBα,E3RSIκB and UBC5,thereby inhibiting the activation of the NF-κB signaling pathway.As a result,CGMP can significantly reduce the degradation of IκBαin the NF-κB signal pathway,increase the amount of protein trimer-IκBα-p65-p50and decrease nuclear translocation of p65and downstream gene expression by inhibiting the phosphorylation and ubiquitination of IκBαand reducing the expression of p-IκBαand key ubiquitin proteins(E3RSIκB and UBC5).This study illustrates that milk-derived CGMP plays an anti-inflammatory role by regulating the NF-κB signal pathway.

关 键 词：酪蛋白糖巨肽 结肠癌细胞 核因子-ΚB 磷酸化核因子-κB抑制因子α 泛素-蛋白连接酶亚单位 

分 类 号：R151[医药卫生—营养与食品卫生学]