Oral Administration of Bovine and Porcine Milk Exosome Alter miRNAs Profiles in Piglet Serum

Abstract

Breast milk is the most important nutrient source for newborn mammals. Studies have reported that milk contains microRNAs (miRNAs), which are potential regulatory components. Currently, existing functional and nutritional two competing hypotheses in milk field though little date have been provided for nutritional hypothesis. In this study, we used the qRT-PCR method to evaluated whether milk miRNAs can be absorbed by newborn piglets by feeding them porcine or bovine milk. The result showed that miRNA levels (miR-2284×, 2291, 7134, 1343, 500, 223) were significantly different between bovine and porcine milk. Four miRNAs (miR-2284×, 2291, 7134, 1343) were significantly different in piglet serum after feeding porcine or bovine milk. After separated milk exosomes by ultracentrifugation, the results showed the selected milk miRNAs (miR-2284×, 2291, 7134, 1343) were present in both exosomes and supernatants, and the miRNAs showed the coincidental expression in IPEC-J2 cells. All our founding suggested that the milk miRNAs can be absorbed both in vivo and in vitro, which will building the foundation for understanding whether these sort of miRNAs exert physiological functions after being absorbed and provided additional evidence for the nutritional hypotheses. Breast milk is the first and most important source of nutrition for newborn mammals 1. By differential centrifugation, milk can be divided into milk fat, whey, casein, cells, and debris and further separated by ultra-centrifugation into extracellular vesicles (EVs) and supernatant 2. Exosomes, which are EVs of 30-100 nm in diameter and of endocytic origin, are released by numerous cells and are present in several body fluids, including saliva 3,4 , plasma 5 , urine 6 , amniotic fluid 7 , malignant ascites 8 , bronchoalveolar lavage fluid 9 , and synovial fluids 10. Studies have reported that exosomes contain lipids, proteins, mRNA, and microRNA (miRNA) 11-14 and that they serve as novel vehicles in cell-to-cell communication 15,16. Just like other body fluids, milk contains EVs 2,17. Hata et al. detected the presence of mRNA and miRNA in bovine milk-derived vesicles 18. MiRNAs represent a class of endogenous non-coding RNAs of approximately 22 nucleotides in length that are widely distributed in eukaryotes. The biological function of miRNAs is to destabilize mRNAs or halt mRNA translation 19,20. Studies have reported that 12 body fluids contain miRNAs, and milk has the highest concentration of total RNA that is rich in miRNAs 21. Milk components that contain miRNAs include milk fat globules 22 , whey 23,24 , and exosomes 11,15. Interestingly, Izumi et al. suggested that miRNAs were also present in the supernatant of ultra-centrifuged bovine raw milk 25. Furthermore, Zhou et al. confirmed the presence of 452 pre-miRNAs in human milk exosomes, which lead to 602 mature miRNAs 26. Chen et al. reported the presence of 245 miRNAs in bovine milk 27 , and Kosaka et al. detected 281 of 723 known human miRNAs in human milk by microarray technology 28. Porcine milk exosomes c...

Milk Exosomes: Perspective Agents for Anticancer Drug Delivery

“…Nonloaded camel milk exosomes contributed to a significant reduction in the progression of breast tumors, as evidenced by increased markers of apoptotic processes as well as oxidative stress reduction and downregulation of several genes associated with inflammatory processes and induction of the immune response [ 91 ]. Because the widespread consumption of milk and dairy products probably contributed to the development of human immune tolerance to milk proteins, milk exosomes can be used as delivery systems for oral drug administration [ 92 ].…”

“…Long noncoding RNA of porcine milk exosomes may interact with miRNA related to cell proliferation, and circular RNA may target miRNA associated with intestinal cells [ 60 ]. A recent paper showed that miRNAs from bovine and porcine milk were adsorbed in piglet intestine and transported to the blood serum with different efficiencies [ 92 ].…”

Lifetime Impact of Cow’s Milk on Overactivation of mTORC1: From Fetal to Childhood Overgrowth, Acne, Diabetes, Cancers, and Neurodegeneration

“…Pasteurized milk transfers bioavailable milk-derived exosomes (MEX) and their gene-regulatory microRNAs (miRs) [ 132 , 133 , 134 , 135 , 136 , 137 ]. Bovine and human MEX and their miRs resist degradative conditions in the gastrointestinal tract, reach the systemic circulation, and distribute in various tissues [ 134 , 138 , 139 , 140 , 141 , 142 , 143 , 144 ]. In fact, increasing evidence presented by studies in humans and animal models supports the view that MEX and their miRs are bioavailable and reach the systemic circulation [ 134 , 136 , 145 , 146 , 147 ], and modify gene expression of the milk recipient [ 132 , 148 , 149 , 150 ].…”

Circulating microRNAs in Breast Milk and Their Potential Impact on the Infant

“…They suggest that whereas exosomes appear to protect miRNA in the skim milk, this protective effect in the lipid fraction might be due to the exosomes as well, or even because of fat globules or proteins such as Argonaute-2. Lin et al [ 37 ] also proposed that milk-derived miRNA may circulate in plasma joined to proteins, as occurs with some endogenous known miRNA [ 7 , 38 , 39 ]. Another recent study from Smyczynska et al suggests that from all the pasteurization techniques, the High-Pressure Processing method interfere less with miRNA functionality compared to the Holder method [ 40 ].…”

“…Lin et al [ 37 ] analyzed the miRNA profile in piglet serum after oral administration of bovine and porcine milk and studied the differences in miRNA expression profiles both in in vivo and in vitro experiments. Milk-derived miRNAs were found in the piglets’ serum.…”