Project description:Background: Maternal pre-pregnancy BMI is a critical factor influencing the composition of breast milk. Breast milk has abundant extracellular vesicles (EVs) containing various biological molecules (cargo), including miRNAs. EVs are not degraded in the gastrointestinal system and circulation; thus, breast milk EVs (bEVs) interact with other organs in breastfed infants and modify the gene expression of recipient cells using miRNAs. In maternal obesity, miRNAs in bEVs are deregulated, which might be associated with adverse health outcomes in infants. In this study, we examined 798 miRNAs to determine which miRNAs are altered in the bEVs of obese mothers and their potential impact on breastfed infants. Methods: We recruited healthy nursing mothers who were either obese (BMI≥30) or lean (BMI<25) based on their pre-pregnancy BMI, and delivered a singleton baby in the prior six months. EVs were isolated from breast milk with ultracentrifugation. bEV characteristics were examined by flow cytometry and fluorescence imaging of EV markers. A total of 798 miRNAs were screened using a NanoString human miRNA panel to find deregulated miRNAs in bEVs of obese mothers compared to lean mothers. Results: We included 65 nursing mothers: 47 lean and 18 obese mothers based on pre-pregnancy BMI. After bEV isolation, we confirmed the expression of general EV markers. Out of 37 EV markers, CD326 was the most highly expressed marker in bEVs. From miRNA analysis using NanoString, we found that the most abundant miRNAs include miR-30b-5p, miR-494-3p, and let-7 families, and the list of top 10 miRNAs was not different between lean and obese mothers. Target genes of the top 10 miRNAs were associated with the EGFR, ErbB, and FoxO signaling pathway. Nineteen miRNAs were deregulated in bEVs of obese mothers (adjusted p < 0.05 cut-off), including miR-575, miR-548g-3p, miR-582-3p, and miR-652-5p. The target genes of these miRNAs are associated with lipid metabolism, inflammatory diseases, and nervous/cardiovascular system development. Conclusion: In this study, we demonstrated altered miRNAs in bEVs of obese mothers and identified the pathways of their potential target genes. Our findings will provide insight for future studies investigating the role of bEVs in breastfed infants.
Project description:Given that different diets could alter cow milk yield and composition, the effects of different feed formula on milk extracellular vesicle (EV) miRNAs were detected. Cow milk EVs contained various small RNAs, including miRNAs, snRNAs, tiRNAs, Cis-regulatory elements, and piRNAs. Two hundred and seventy-six known bos taurus miRNAs were identified by sequencing in bovine milk EVs. There were 13 immune-related miRNAs in the top 20 miRNAs in milk EVs. Nine differently expressed known miRNAs were detected in responding to different feed formulations. Cow milk EVs are abundant of small RNAs, especially miRNAs, which might be closely related to the development of maternal mammary gland and neonatal immune maturity.
Project description:EVP miRNAs levels were measured in the supernatant fraction of 54 human milk samples collected approximately 6 weeks postpartum from individuals in New Hampshire using the NanoString nCounter Human v3 miRNA expression panel
Project description:Milk can mediate maternal-neonatal signal transmission by the bioactive component-extracellular vesicles (EVs), which select specific types of miRNA to encapsulate. The miRNA profiling of sheep milk EVs was characterized by sequencing and compared with that of cow milk. Sheep milk EVs contained various small RNAs, including tRNA, Cis-regulatory element, rRNA, snRNA, other Rfam RNA, and miRNA, which held about 36% of all the small RNAs. Totally 84 types of miRNAs were annotated with Ovis aries by miRBase (version 22.0) in sheep milk EVs, with 75 shared types of miRNAs in all samples. Fourteen sheep milk EV-miRNAs in the top 20, occupying 98% of the total expression, were immune-related.
Project description:To study the impact of the obesity condition on circulating Extracellular Vesicle-miRNA expression signature in breast cancer patients, and identify potential obesity-related miRNAs that may be associated with progression.
Project description:MicroRNAs are important regulators of cell-autonomous gene expression that influences many biological processes. They are also released from cells and are present in virtually all body fluids, including blood, urine, saliva, sweat, and milk. The functional role of extracellular miRNAs is controversial, and irrefutable demonstration of miRNA uptake by cells and canonical miRNA function is still lacking. Here we show that miRNAs are present at high levels in milk of lactating mice. To investigate intestinal uptake of miRNAs in newborn mice, we employed genetic models in which newborn miR-375 and miR-200c KO mice received milk from wildtype foster mothers. Analysis of intestinal epithelium, blood, liver and spleen revealed no evidence for miRNA uptake. miR-375 levels in hepatocytes were at the limit of detection and remained orders of magnitude below the threshold for target gene regulation (between 1000 and 10,000 copies/cell). Furthermore, our study revealed rapid degradation of milk miRNAs in the intestinal fluid. Together, our results indicate a nutritional rather than gene regulatory role of miRNAs in milk of newborn mice.