National Engineering Research Center For Breeding Swine Industry, Guangdong Provincial Key Laboratory of Agro-Animal Genomics and Molecular Breeding, Guangdong Province Research Center of Woody Forage Engineering and Technology, Guangdong Provincial Key Laboratory of Animal Nutrition Control, South China Agricultural University, 483 Wushan Road, Guangzhou, 510642, China.
Institute of Animal Science and Veterinary Medicine, Hainan Academy of Agricultural Sciences, Haikou, 571100, China.
Sci Rep. 2020 Apr 24;10(1):6983. doi: 10.1038/s41598-020-63485-8.
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.
母乳是新生哺乳动物最重要的营养来源。研究报道称，牛奶中含有 microRNAs（miRNAs），它们是潜在的调节成分。目前，尽管营养假说提供的证据很少，但在牛奶领域存在两种相互竞争的现有功能和营养假说。在这项研究中，我们使用 qRT-PCR 方法评估了通过给新生仔猪喂食猪或牛的奶是否可以吸收奶中的 miRNAs。结果表明，牛和猪的奶中的 miRNA 水平（miR-2284×、2291、7134、1343、500、223）存在显著差异。在给仔猪喂食猪或牛的奶后，其血清中的四种 miRNAs（miR-2284×、2291、7134、1343）存在显著差异。经过超速离心分离牛奶外泌体后，结果表明所选的牛奶 miRNAs（miR-2284×、2291、7134、1343）既存在于外泌体中，也存在于上清液中，并且在 IPEC-J2 细胞中这些 miRNAs 表现出一致的表达。我们所有的研究结果表明，牛奶中的 miRNAs 既可以在体内也可以在体外被吸收，这将为理解这些 miRNA 在被吸收后是否发挥生理功能奠定基础，并为营养假说提供额外的证据。
