Oliver Charlotte, Mishra Vinay S N, Santoro Jessie, Mukhopadhya Anindya, Buckley Frank, O'Driscoll Lorraine, Giblin Linda, Brodkorb André
Teagasc Food Research Centre, Moorepark, Fermoy, Co. Cork, P61C996, Ireland.
School of Pharmacy and Pharmaceutical Sciences & Trinity Biomedical Sciences Institute, Trinity College Dublin, Dublin 2, Ireland.
Mol Nutr Food Res. 2024 May;68(10):e2300620. doi: 10.1002/mnfr.202300620. Epub 2024 May 6.
Milk extracellular vesicles (EVs) are nanosized particles with potential immune bioactivities. This study examines their fate during in vitro infant gastrointestinal digestion (GI).
Bovine milk is digested using the in vitro INFOGEST method, adjusted for the infant. To unravel the contribution of digestive enzymes from bile, milk is treated with digestive enzymes, bile, or a combination of both. EVs are collected posttreatment using differential ultracentrifugation. EVs characterization includes electrophoresis, immunoblotting, nanoparticle tracking analysis, and atomic force microscopy. EVs protein markers programmed cell death 6-interacting protein (ALIX), tumor susceptibility gene 101 (TSG101), cluster of differentiation 9 (CD9), and xanthine dehydrogenase (XDH) are detected after gastric digestion (G60), but their signal intensity is significantly reduced by intestinal conditions (p < 0.05). Enzyme digestion, compared to bile treatment (I60 + bile), results in a significant reduction of signal intensities for TSG101 and CD9 (p < 0.05). Nanoparticle tracking analysis shows a significant reduction (p < 0.05) of EV numbers at the end of the intestinal phase. EVs are detected by atomic force microscopy at the end of the intestinal phase, showing that intact EVs can survive upper gut digestion.
Intact EVs can be found at the end of the intestinal phase. However, digestive enzymes and bile reduce the quantity and characteristics of EVs, with digestive enzymes playing a larger role.
牛奶细胞外囊泡（EVs）是具有潜在免疫生物活性的纳米级颗粒。本研究考察了它们在体外婴儿胃肠道消化（GI）过程中的命运。
采用针对婴儿调整后的体外INFOGEST方法对牛乳进行消化。为了阐明胆汁中消化酶的作用，分别用消化酶、胆汁或两者的组合处理牛奶。处理后使用差速超速离心法收集细胞外囊泡。细胞外囊泡的表征包括电泳、免疫印迹、纳米颗粒跟踪分析和原子力显微镜检查。在胃消化（G60）后检测到细胞外囊泡的蛋白质标志物程序性细胞死亡6相互作用蛋白（ALIX）、肿瘤易感基因101（TSG101）、分化簇9（CD9）和黄嘌呤脱氢酶（XDH），但它们的信号强度在肠道环境中显著降低（p < 0.05）。与胆汁处理（I60 + 胆汁）相比，酶消化导致TSG101和CD9的信号强度显著降低（p < 0.05）。纳米颗粒跟踪分析显示在肠道消化阶段结束时细胞外囊泡数量显著减少（p < 0.05）。在肠道消化阶段结束时通过原子力显微镜检测到细胞外囊泡，表明完整的细胞外囊泡能够在上消化道消化中存活。
在肠道消化阶段结束时可以发现完整的细胞外囊泡。然而，消化酶和胆汁会降低细胞外囊泡的数量和特性，其中消化酶起的作用更大。
