α-乳白蛋白与β-酪蛋白预防炎症的协同作用研究

Study on the Synergistic Effect ofα-lactalbumin andβ-casein on Preventing Inflammation

牛乳中酪蛋白比例高,而母乳中乳清蛋白含量高,α-乳白蛋白、β-酪蛋白作为母乳中主要的乳清蛋白和酪蛋白,以α-乳白蛋白和β-酪蛋白为研究对象,利用脂多糖(LPS)诱导RAW264.7细胞炎症反应,探究不同比例的组合蛋白对细胞炎症的预防作用,探索乳清蛋白和酪蛋白的最佳配比,使婴配粉更贴合母乳。结果表明,添加α-乳白蛋白和β-酪蛋白单体能改变炎症因子mRNA和蛋白水平的表达,然而当混合比例为1:0.17时效果最佳,能显著降低白介素6(IL-6)、白介素10(IL-10)、髓样分化基因88(MyD88)、Toll样受体4(TLR4)在mRNA水平的表达,在蛋白水平降低IL-61.99倍、白介素1β(IL-1β)3.91倍、肿瘤坏死因子α(TNF-α)2.72倍。通过抑制非TLR4介导炎症信号通路关键蛋白NF-κB p65的磷酸化抑制炎症的发生。本研究明确了α-乳白蛋白和β-酪蛋白预防炎症发生的最佳比例,初步阐明了两者协同抗炎的作用机理,为其在婴幼儿配方奶粉中的精准添加提供理论支持和技术指导。

Breast milk is the best source of nutrition for infants.Therefore,the breastfeeding of infant formula is of great significance for the acquisition of nutrients and the establishment of immune function.Milk has a high proportion of casein,while breast milk has a high content of whey protein.We usedα-lactalbumin andβ-casein,the main whey protein and casein in breast milk,to represent whey protein and casein and explored the best ratio of whey protein and casein,so as to make baby powder more suitable for breast milk.In this study,α-lactalbumin andβ-casein were used to relieve inflammation in RAW264.7 cells induced by lipopolysaccharide(LPS)to explore the preventive effects of different proportions of combination proteins on cell inflammation.The results showed thatα-lactalbumin andβ-casein monomers could change the expression of mRNA and protein levels of inflammatory cytokines.Meanwhile,the mixing ratio of 1:0.17 showed the best effect,which could significantly reduce the expression of interleukin-6(IL-6),interleukin-10(IL-10),myeloid differentiation gene 88(MyD88)and Tolllike receptor 4(TLR4)at the mRNA level.The protein expression levels of interleukin 6(IL-6)was significantly reduced by 1.5 times,3 times in interleukin1β(IL-1β)and 2 times in tumor necrosis factorα(TNF-α).And inhibits inflammation by inhibiting the phosphorylation of NF-κB p65,not dependent on TLR4-mediated inflammatory signaling pathway.In the current study,the optimal ratio ofα-lactalbumin andβ-casein to prevent inflammation was determined and the synergistic anti-inflammatory mechanism ofα-lactalbumin andβ-casein was clarified,providing theoretical support and technical guidance for the precise addition ofα-lactalbumin to infant formula milk powder.