Characterization and biological function of milk-derived miRNAs

Area of Science:

• Biochemistry
• Genetics
• Pediatrics

Background:

• Breastfeeding offers significant health benefits, including reduced risks of infection, immune disorders, obesity, and cancer.
• Breast milk contains microRNAs (miRNAs) in skim and fat layers, transferable to infants, influencing biological functions.

Purpose of the Study:

• To profile microRNA expression in human, goat, and bovine milk, and infant formulas.
• To investigate the presence and conservation of miRNAs in milk fractions.
• To assess the functional impact of milk-derived miRNAs on normal and cancer cells.

Main Methods:

• Next-generation sequencing and quantitative real-time PCR were used to analyze miRNA expression.
• Human, goat, and bovine milk (skim and fat fractions) and infant formulas were analyzed.
• In vitro cell culture experiments were performed using milk-derived miRNAs and normal/cancer cells.

Main Results:

• Advantageous miRNAs were identified in exosomes and fat layers of human, goat, and bovine milk, showing high conservation.
• These beneficial miRNAs were notably absent in several tested infant formulas.
• Milk-derived miRNAs, specifically miRNA-148a, entered cells and modulated gene expression, downregulating DNA methyltransferase 1.

Conclusions:

• The findings confirm the critical role of miRNAs in breast milk for infant health.
• Future research should focus on incorporating essential miRNAs into infant formulas to mimic breastfeeding benefits.