Analyzing the Function of Exosome's microRNA in Milk by Comparing the Expression of microRNA in Milk and Exosome

Milk contains fats, carbohydrates, proteins, RNAs and enzymes, but also mRNA and microRNAs(miRNA), which plays an important role in neonatal innate and adaptive immunity. The following study investigates whether or not miRNA of exosome in milk is a vital pathway for miRNA of milk absorbing. Briefly, 280 pre-miRNAs and 326 mature miRNA were found. 37 exosomal miRNAs were upregulated (twice fold) compared to miRNAs found outside the exosomes. Among these miRNAs, ssc-miR-193a-3p's expression was up regulated 1467.35 times, while ssc-miR-423-5p?ssc-miR-551a?ssc-miR-138?ssc-miR-1 and ssc-miR-124a were highly concentrated and upregulated from 13.58 to 30.06 times. Moreover, all of these miRNAs play essential roles in cell's development and basic physiology processes in immune system. Following the analysis of target gene prediction and related signaling pathways, 9262 target genes showed to be mainly concentrated on three signaling pathway: metabolic pathways?pathways in cancer, and Phosphatidylinositol 3-kinase /Protein Kinase B(PI3K/Akt) signaling pathways. In addition, more than 20 miRNAs showed to be highly concentrated on exosomes, such as MECP2?GYS1? LRRC8A?BCL9L?PHRF1 and ELOVL1, all closely related to immunity and engendering of gene. After performing in-depth research on miRNA's localization, distribution and function related metabolism, we found that these exosome concentrated miRNA's target genes were interrelated to development and basic cell functions, like metabolism and immunity. These results imply that miRNAs in breast milk can influence offspring via milk exosomes. Overall design: Three Experimental swine milk. Small intestine of piglets at 31 days old was collected from Pig Breeding Farm in Chongqing Academy of Animal Science, China. Exosome were collected from the swine milk. Three individuals were randomly selected for biological replicates.

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