ABSTRACT
The aim of this study was to investigate the therapeutic effect of cow and human milk derived exosomes (MDEs) on colitis. We used gavage administration of fluorescent labeled MDEs to track their localization patterns in vivo and studied their therapeutic effect on colitis in a dextran sulfate sodium (DSS)-induced colitis model. MDEs attenuated the severity of colitis induced by DSS and statistically reduced the histopathological scoring grade and shortening of the colon. Likewise, treatment with MDEs reduced the expression of interleukin 6 and tumor necrosis factor-α. Moreover, miRNAs highly expressed in milk, such as miRNA-320, 375, and Let-7, were found to be more abundant in the colon of MDE-treated mice compared with untreated mice; contrastingly, the expression of their target genes, mainly DNA methyltransferase 1 (DNMT1) and DNMT3 were downregulated. Furthermore, the level of TGF-ß was upregulated in the colon of MDE-treated mice. We demonstrated that MDEs have a therapeutic and anti-inflammatory effect on colitis, involving several complementary pathways in its mechanism of action. The therapeutic effects of MDEs might have implications for the possible addition of MDEs as a nutrient in enteral nutrition formulas for patients with inflammatory bowel disease.
Subject(s)
Colitis/therapy , Exosomes/metabolism , Milk, Human/metabolism , Milk/metabolism , Animals , Dextran Sulfate , Disease Models, Animal , Humans , Mice , Mice, Inbred BALB CABSTRACT
BACKGROUND: Breastfeeding is the ideal source of infant nutrition. Human milk consists not only of nutrients but also biologically active components. Among these latter compounds, exosomes contain proteins, lipids, mRNAs and miRNAs. METHODS: To elucidate the biological effects of milk-derived exosomes (MDEs) on normal colonic epithelial cells compared to colonic tumor cells, we incubated cells with MDEs. MDEs were able to enter into normal and tumor cells and change their miRNA expression profiles. Proliferation, cell morphology and protein expression were analyzed in these cells. RESULTS: Human milk-derived exosomes induced proliferation- and epithelial mesenchymal transformation-related changes, such as collagen type I and twist expression, in normal but not in tumor cells. PTEN, a target of miRNA-148a, was downregulated in normal but not in tumor cells following incubation with MDEs. Moreover, miRNA-148a-3p knockdown cells were used to demonstrate the importance of miRNA in the effect of exosomes on cell proliferation and protein expression. MDEs inhibited proliferation and DNMT1 expression in cells with knockdown of miRNA-148a. CONCLUSIONS: In conclusion, the positive effect of exosomes on normal cells without affecting tumor cells may presents an aspect of their safety when considering it use as a nutritional supplement to infant formula.
Subject(s)
Colon/cytology , Colonic Neoplasms/pathology , Epithelial Cells/cytology , Exosomes/metabolism , Fetus/cytology , MicroRNAs/metabolism , Milk, Human/metabolism , Animals , Cattle , Cell Line, Tumor , Cell Proliferation , Cell Shape , DNA (Cytosine-5-)-Methyltransferase 1/genetics , DNA (Cytosine-5-)-Methyltransferase 1/metabolism , Down-Regulation/genetics , Humans , MicroRNAs/genetics , PTEN Phosphohydrolase/genetics , PTEN Phosphohydrolase/metabolism , RNA, Messenger/genetics , RNA, Messenger/metabolismABSTRACT
SCOPE: Breastfeeding is associated with reduced risk of infection, immune-mediated disorders, obesity, and even cancer. Recently it was found that breast milk contains a variety of microRNAs (miRNAs) in the skim and fat layer that can be transferred to infants, and appear to play important roles in those biological functions. METHODS AND RESULTS: This study applied next generation sequencing and quantitative real-time PCR analysis to determine the miRNA expression profile of the skim and fat fraction of human, goat, and bovine milk as well as infant formulas. Human and mammalian milk were found to contain known advantageous miRNAs in exosomes and also in the fat layer. These miRNAs are highly conserved in human, bovine and goat milk. However, they were not detected in several infant formulas. Further, miRNAs present in milk were able to enter normal and tumor cells and affect their biological functions. Following incubation of milk derived human miRNA with normal and cancer cells, the expression of miRNA-148a was upregulated and the expression of the DNA methyltransferase1 target gene of miRNA-148a was down regulated. CONCLUSION: These results reinforce previous findings on the importance of miRNA in breast milk. Future studies should concentrate on the addition of miRNA to infant formulas.
