Abundantly Present miRNAs in Milk-Derived Extracellular Vesicles Are Conserved Between Mammals

Assessment of isolation strategies to remove caseins for high-quality milk-derived extracellular vesicles

Increasing studies have highlighted the significance of milk-derived extracellular vesicles (MEV) in mother-newborn integration, as well as their application as novel drug delivery systems and diagnostic biomarkers. However, conventional ultracentrifugation (UC) often results in the co-precipitation of casein micelles in MEV pellets. In this study, we compared methods with different principles to screen the optimal pretreatment in caseins removal, and found that isoelectric precipitation by hydrochloric acid (HA) could most effectively remove caseins in porcine milk. We further characterized MEV populations isolated by UC and HA/UC from diverse aspects, including particle methodology via nanoparticle tracking analysis (NTA) and transmission electron microscopy (TEM), RNA and protein contents, and purity analysis. Importantly, the proliferative and anti-inflammatory effects of MEV were evaluated in vitro, showing the superiority of MEV via HA/UC in functionality compared with UC. Our results suggest that HA pretreatment before ultracentrifugation could effectively remove caseins and other protein complexes, making MEV with higher purity and more significant effects in vitro. This study provides valuable insights for the advancement of MEV isolation techniques across different species and accurate function analysis of MEV.

Dairy: Friend or Foe? Bovine Milk-Derived Extracellular Vesicles and Autoimmune Diseases

Due to the availability, scalability, and low immunogenicity, bovine milk-derived extracellular vesicles (MEVs) are increasingly considered to be a promising carrier of nanomedicines for future therapy. However, considering that extracellular vesicles (EVs) are of biological origin, different sources of EVs, including the host origin and the specific cells that produce the EVs, may have different effects on the structure and function of EVs. Additionally, MEVs play an important role in immune regulation, due to their evolutionary conserved cargo, such as cytokines and miRNAs. Their potential effects on different organs, as well as their accumulation in the human body, should not be overlooked. In this review, we have summarized current impacts and research progress brought about by utilizing MEVs as nano-drug carriers. Nevertheless, we also aim to explore the possible connections between the molecules involved in cellular immunity, cytokines and miRNAs of MEVs produced under different health conditions, and autoimmune diseases.

Milk-Derived Extracellular Vesicles Carrying ssc-let-7c Alleviate Early Intestinal Inflammation and Regulate Macrophage Polarization via Targeting the PTEN-Mediated PI3K/Akt Pathway

Milk-derived extracellular vesicles (mEVs) are beneficial to the health of infants. However, the effect of mEVs on early intestinal inflammation is not well established. Herein, weaned colitic mice were used to explore the potential effects and underlying mechanisms of porcine mEVs (pmEVs) on intestinal inflammation during early life. We found that pmEVs administration attenuated early life intestinal inflammation and promoted colonic barrier integrity in mice. The anti-inflammatory effect of pmEVs was achieved by shifting a proinflammatory macrophage (M1) toward an anti-inflammatory macrophage (M2). Moreover, pmEVs can be absorbed by macrophages and reduce proinflammatory polarization (stimulated by LPS) in vitro. Noteworthily, ssc-let-7c was found to be highly expressed in pmEVs that can regulate the polarization of macrophages by targeting the tensin homologue deleted on chromosome ten (PTEN), thereby activating the PI3K/Akt pathway. Collectively, our findings revealed a crucial role of mEVs in early intestinal immunity and its underlying mechanism.

mRNA expression profiles in muscle-derived extracellular vesicles of Large White and wild boar piglets reveal their potential roles in immunity and muscle phenotype

Introduction

Extracellular vesicles (EVs) known for their pivotal role in intercellular communication through RNA delivery, hold paramount implications for understanding muscle phenotypic variations in diverse pig breeds.

Methods

In this study, we compared the mRNA expression profiles of longissimus dorsi muscles and muscle-derived extracellular vesicles (M-EVs), and also examined the diversity of enriched genes in M-EVs between weaned wild boars and commercial Large White pigs with respect to their numbers and biological functions.

Results

The results of the study showed that the variation in the expression profiles of mRNAs between muscles and M-EVs was much greater than the variability between the respective breeds. Meanwhile, the enrichment trend of low-expressed genes (ranked <1,000) was significantly (p-value ≤ 0.05) powerful in M-EVs compared to highly expressed genes in muscles. In addition, M-EVs carried a smaller proportion of coding sequences and a larger proportion of untranslated region sequences compared to muscles. There were 2,110 genes enriched in M-EVs (MEGs) in Large White pigs and 2,322 MEGs in wild boars, with 1,490 MEGs shared interbreeds including cyclin D2 (CCND2), which inhibits myogenic differentiation. Of the 89 KEGG pathways that were significantly enriched (p-value ≤ 0.05) for these MEGs, 13 unique to Large White pigs were mainly related to immunity, 27 unique to wild boars were functionally diverse but included cell fate regulation such as the Notch signaling pathway and the TGF-beta signaling pathway, and 49 were common to both breeds were also functionally complex but partially related to innate immunity, such as the Complement and coagulation cascades and the Fc gamma R-mediated phagocytosis.

Discussion

These findings suggest that mRNAs in M-EVs have the potential to serve as indicators of muscle phenotype differences between the two pig breeds, highlighting the need for further exploration into the role of EV-RNAs in pig phenotype formation.

Sheep (Ovis aries) Milk Exosomal miRNAs Attenuate Dextran Sulfate Sodium-Induced Colitis in Mice via TLR4 and TRAF-1 Inhibition

Mammalian milk exosomal miRNAs play an important role in maintaining intestinal immune homeostasis and protecting epithelial barrier function, but the specific miRNAs and whether miRNA-mediated mechanisms are responsible for these benefits remain a matter of investigation. This study isolated sheep milk-derived exosomes (sheep MDEs), identifying the enriched miRNAs in sheep MDEs, oar-miR-148a, and oar-let-7b as key components targeting TLR4 and TRAF1, which was validated by a dual-luciferase reporter assay. In dextran sulfate sodium-induced colitis mice, administration of sheep MDEs alleviated colitis symptoms, reduced colonic inflammation, and systemic oxidative stress, as well as significantly increased colonic oar-miR-148a and oar-let-7b while reducing toll-like receptor 4 (TLR4) and TNF-receptor-associated factor 1 (TRAF1) level. Further characterization in TNF-α-challenged Caco-2 cells showed that overexpression of these miRNAs suppressed the TLR4/TRAF1-IκBα-p65 pathway and reduced IL-6 and IL-12 production. These findings indicate that sheep MDEs exert gastrointestinal anti-inflammatory effects through the miRNA-mediated modulation of TLR4 and TRAF1, highlighting their potential in managing colitis.

Analysis of miRNAs in milk of four livestock species

BACKGROUND

Milk is essential for mammalian nutrition because it provides vital nutrients for growth and development. Milk composition, which is influenced by genetic and environmental factors, supports lactation, a complex process crucial for milk production and quality. Recent research has focused on noncoding RNAs, particularly microRNAs (miRNAs), which are present in body fluids and regulate gene expression post-transcriptionally. This study comprehensively characterizes miRNAs in milk of four livestock species, namely Bubalus bubalis, Capra hircus, Equus asinus, and Ovis aries and identifies potential target genes.

RESULTS

High-throughput sequencing of milk RNA resulted in distinct read counts across species: B. bubalis (8,790,441 reads), C. hircus (12,976,275 reads), E. asinus (9,385,067 reads), and O. aries (7,295,297 reads). E. asinus had the highest RNA mapping rate (94.6%) and O. aries the lowest (84.8%). A substantially greater proportion of miRNAs over other small RNAs was observed for the donkey milk sample (7.74%) compared to buffalo (0.87%), goat (1.57%), and sheep (1.12%). Shared miRNAs, which included miR-200a, miR-200b, miR-200c, and miR-23a among others, showed varying expression levels across species, confirmed by qPCR analysis. Functional annotation of predicted miRNA target genes highlighted diverse roles, with an enrichment in functions linked to metabolism and immunity. Pathway analysis identified immune response pathways as significant, with several miRNAs targeting specific genes across species, suggesting their regulatory function in milk.

CONCLUSIONS

Both conserved and species-specific miRNAs were detected in milk of the investigated species. The identified target genes of these miRNAs have important roles in neonatal development, adaptation, growth, and immune response. Furthermore, they influence milk and meat production traits in livestock.

Risk of Fat Mass- and Obesity-Associated Gene-Dependent Obesogenic Programming by Formula Feeding Compared to Breastfeeding

It is the purpose of this review to compare differences in postnatal epigenetic programming at the level of DNA and RNA methylation and later obesity risk between infants receiving artificial formula feeding (FF) in contrast to natural breastfeeding (BF). FF bears the risk of aberrant epigenetic programming at the level of DNA methylation and enhances the expression of the RNA demethylase fat mass- and obesity-associated gene (FTO), pointing to further deviations in the RNA methylome. Based on a literature search through Web of Science, Google Scholar, and PubMed databases concerning the dietary and epigenetic factors influencing FTO gene and FTO protein expression and FTO activity, FTO's impact on postnatal adipogenic programming was investigated. Accumulated translational evidence underscores that total protein intake as well as tryptophan, kynurenine, branched-chain amino acids, milk exosomal miRNAs, NADP, and NADPH are crucial regulators modifying FTO gene expression and FTO activity. Increased FTO-mTORC1-S6K1 signaling may epigenetically suppress the WNT/β-catenin pathway, enhancing adipocyte precursor cell proliferation and adipogenesis. Formula-induced FTO-dependent alterations of the N6-methyladenosine (m6A) RNA methylome may represent novel unfavorable molecular events in the postnatal development of adipogenesis and obesity, necessitating further investigations. BF provides physiological epigenetic DNA and RNA regulation, a compelling reason to rely on BF.

Extracellular vesicles: an emerging tool for wild immunology

The immune system is crucial for defending organisms against pathogens and maintaining health. Traditionally, research in immunology has relied on laboratory animals to understand how the immune system works. However, there is increasing recognition that wild animals, due to their greater genetic diversity, lifespan, and environmental exposures, have much to contribute to basic and translational immunology. Unfortunately, logistical challenges associated with collecting and storing samples from wildlife, and the lack of commercially available species-specific reagents have hindered the advancement of immunological research on wild species. Extracellular vesicles (EVs) are cell-derived nanoparticles present in all body fluids and tissues of organisms spanning from bacteria to mammals. Human and lab animal studies indicate that EVs are involved in a range of immunological processes, and recent work shows that EVs may play similar roles in diverse wildlife species. Thus, EVs can expand the toolbox available for wild immunology research, helping to overcome some of the challenges associated with this work. In this paper, we explore the potential application of EVs to wild immunology. First, we review current understanding of EV biology across diverse organisms. Next, we discuss key insights into the immune system gained from research on EVs in human and laboratory animal models and highlight emerging evidence from wild species. Finally, we identify research themes in wild immunology that can immediately benefit from the study of EVs and describe practical considerations for using EVs in wildlife research.

Gut-liver axis: Potential mechanisms of action of food-derived extracellular vesicles

Food-derived extracellular vesicles (FEVs) are nanoscale membrane vesicles obtained from dietary materials such as breast milk, plants and probiotics. Distinct from other EVs, FEVs can survive the harsh degrading conditions in the gastrointestinal tract and reach the intestines. This unique feature allows FEVs to be promising prebiotics in health and oral nanomedicine for gut disorders, such as inflammatory bowel disease. Interestingly, therapeutic effects of FEVs have recently also been observed in non-gastrointestinal diseases. However, the mechanisms remain unclear or even mysterious. It is speculated that orally administered FEVs could enter the bloodstream, reach remote organs, and thus exert therapeutic effects therein. However, emerging evidence suggests that the amount of FEVs reaching organs beyond the gastrointestinal tract is marginal and may be insufficient to account for the significant therapeutic effects achieved regarding diseases involving remote organs such as the liver. Thus, we herein propose that FEVs primarily act locally in the intestine by modulating intestinal microenvironments such as barrier integrity and microbiota, thereby eliciting therapeutic impact remotely on the liver in non-gastrointestinal diseases via the gut-liver axis. Likewise, drugs delivered to the gastrointestinal system through FEVs may act via the gut-liver axis. As the liver is the main metabolic hub, the intestinal microenvironment may be implicated in other metabolic diseases. In fact, many patients with non-alcoholic fatty liver disease, obesity, diabetes and cardiovascular disease suffer from a leaky gut and dysbiosis. In this review, we provide an overview of the recent progress in FEVs and discuss their biomedical applications as therapeutic agents and drug delivery systems, highlighting the pivotal role of the gut-liver axis in the mechanisms of action of FEVs for the treatment of gut disorders and metabolic diseases.

Human Breast Milk Exosomal miRNAs are Influenced by Premature Delivery and Affect Neurodevelopment

SCOPE

This study investigates the exosomal microRNA (miRNA) profiles of term and preterm breast milk, including the most abundant and differentially expressed (DE) miRNAs, and their impact on neurodevelopment in infants.

METHODS AND RESULTS

Mature milk is collected from the mothers of term and preterm infants. Using high-throughput sequencing and subsequent data analysis, exosomal miRNA profiles of term and preterm human breast milk (HBM) are acquired and it is found that the let-7 and miR-148 families are the most abundant miRNAs. Additionally, 23 upregulated and 15 downregulated miRNAs are identified. MiR-3168 is the most upregulated miRNA in preterm HBM exosome, exhibiting targeting activity toward multiple genes involved in the SMAD and MAPK signaling pathways and playing a crucial role in early neurodevelopment. Additionally, the effects of miR-3168 on neurodevelopment is confirmed and it is determined that it is an essential factor in the differentiation of neural stem cells (NSCs).

CONCLUSION

This study demonstrates that miRNA expression in breast milk exosomes can be influenced by preterm delivery, thereby potentially impacting neurodevelopment in preterm infants.

Milk-derived exosome nanovesicles: recent progress and daunting hurdles

Raw milk is the foundation of quality and safety in the dairy industry, and improving milk source management is the fundamental guarantee. Milk-derived exosomes (MDEs) are nanoscale information transfer molecules secreted by mammary cells with unique content and high stability, which can be used not only as potential markers to analyze key traits of lactation, reproduction, nutrition and health of animals, but also help farm managers to take timely interventions to improve animal welfare, milk quality, and functional traits. Our review first outlines the latest advances in MDEs isolation and purification, compositional analysis and characterization tools. We then provide a comprehensive summary of recent applications of MDEs liquid biopsy in breed selection, disease prevention and control, and feeding management. Finally, we evaluate the impact of processing on the stability of MDEs to offer guidance for dairy production and storage. The limitations and challenges in the development and use of MDEs markers are also discussed. As a noninvasive marker with high sensitivity and specificity, the MDEs-mediated assay technology is expected to be a powerful tool for measuring cow health and raw milk quality, enabling dynamic and precise regulation of dairy cows and full traceability of raw milk.

The Difference of Milk-Derived Extracellular Vesicles from Cow Colostrum and Mature Milk on miRNAs Expression and Protecting Intestinal Epithelial Cells against Lipopolysaccharide Damage

Intestinal epithelial cells (IECs) play crucial roles in forming an essential barrier, providing host defense against pathogens and regulating nutrients absorption. Milk-derived extracellular vesicles (EVs) within its miRNAs are capable of modulating the recipient cell function. However, the differences between colostrum and mature milk EVs and their biological function in attenuating intestinal epithelial cell injury remain poorly understood. Thus, we carried out the present study to characterize the difference between colostrum and mature milk-derived miRNA of EVs and the effect of colostrum and mature milk EVs on the proliferation, apoptosis, proinflammatory cytokines and intestinal epithelial barrier related genes in IEC-6 induced by LPS. Differential expression of 329 miRNAs was identified between colostrum and mature milk EVs, with 185 miRNAs being downregulated and 144 upregulated. In addition, colostrum contains a greater number and protein concentration of EVs than mature milk. Furthermore, compared to control, EVs derived from colostrum significantly inhibited the expression of apoptosis- (Bax, p53, and caspase-3) and proinflammatory-related genes (TNFα, IL6, and IL1β). EVs derived from mature milk did not affect expression of apoptosis-related genes (Bax, p53, bcl2, and caspase-3). The EVs derived from mature milk significantly inhibited the expression of proinflammatory-related genes (TNFα and IL6). Western blot analysis also indicated that colostrum and mature milk EVs significantly decreased the apoptosis of IEC-6 cells. The EdU assay results showed that colostrum and mature milk EVs significantly increased the proliferation of IEC-6 cells. The expression of intestinal barrier-related genes (TJP1, CLDN1, OCLN, CDX2, MUC2, and IGF1R) was significantly promoted in IEC-6 cells after colostrum and mature milk EVs addition. Importantly, colostrum and mature milk EVs significantly relieved the LPS-induced inhibition of proliferation and intestinal barrier-related genes expression and attenuated apoptosis and proinflammatory responses induced by LPS in IEC-6 cells. Flow cytometry and Western blot analysis also indicated that colostrum and mature milk EVs significantly affect the apoptosis of IEC-6 cells induced by LPS. The results also indicated that EVs derived from colostrum had better effects on inhibiting the apoptosis- and proinflammatory cytokines-related genes expression. However, the EVs derived from mature milk exhibited beneficial effects on intestinal epithelial barrier protection. The present study will provide a better understanding of the role of EVs derived from colostrum and milk in dairy cows with different responses in the regulation of intestinal cells function, and also presents new evidence for the change of EVs cargos during various stages of lactation.

A Review of the Use of Extracellular Vesicles in the Treatment of Neonatal Diseases: Current State and Problems with Translation to the Clinic

Neonatal disorders, particularly those resulting from prematurity, pose a major challenge in health care and have a significant impact on infant mortality and long-term child health. The limitations of current therapeutic strategies emphasize the need for innovative treatments. New cell-free technologies utilizing extracellular vesicles (EVs) offer a compelling opportunity for neonatal therapy by harnessing the inherent regenerative capabilities of EVs. These nanoscale particles, secreted by a variety of organisms including animals, bacteria, fungi and plants, contain a repertoire of bioactive molecules with therapeutic potential. This review aims to provide a comprehensive assessment of the therapeutic effects of EVs and mechanistic insights into EVs from stem cells, biological fluids and non-animal sources, with a focus on common neonatal conditions such as hypoxic-ischemic encephalopathy, respiratory distress syndrome, bronchopulmonary dysplasia and necrotizing enterocolitis. This review summarizes evidence for the therapeutic potential of EVs, analyzes evidence of their mechanisms of action and discusses the challenges associated with the implementation of EV-based therapies in neonatal clinical practice.

Maternal fiber-rich diet promotes early-life intestinal development in offspring through milk-derived extracellular vesicles carrying miR-146a-5p

BACKGROUNDS

The intestinal development in early life is profoundly influenced by multiple biological components of breast milk, in which milk-derived extracellular vesicles (mEVs) contain a large amount of vertically transmitted signal from the mother. However, little is known about how maternal fiber-rich diet regulates offspring intestinal development by influencing the mEVs.

RESULTS

In this study, we found that maternal resistant starch (RS) consumption during late gestation and lactation improved the growth and intestinal health of offspring. The mEVs in breast milk are the primary factor driving these beneficial effects, especially enhancing intestinal cell proliferation and migration. To be specific, administration of mEVs after maternal RS intake enhanced intestinal cell proliferation and migration in vivo (performed in mice model and indicated by intestinal histological observation, EdU assay, and the quantification of cyclin proteins) and in vitro (indicated by CCK8, MTT, EdU, and wound healing experiments). Noteworthily, miR-146a-5p was found to be highly expressed in the mEVs from maternal RS group, which also promotes intestinal cell proliferation in cells and mice models. Mechanically, miR-146a-5p target to silence the expression of ubiquitin ligase 3 gene NEDD4L, thereby inhibiting DVL2 ubiquitination, activating the Wnt pathway, and promoting intestinal development.

CONCLUSION

These findings demonstrated the beneficial role of mEVs in the connection between maternal fiber rich diet and offspring intestinal growth. In addition, we identified a novel miRNA-146a-5p-NEDD4L-β-catenin/Wnt signaling axis in regulating early intestinal development. This work provided a new perspective for studying the influence of maternal diet on offspring development.

Breed-Related Differential microRNA Expression and Analysis of Colostrum and Mature Milk Exosomes in Bamei and Landrace Pigs

Breast milk, an indispensable source of immunological and nutrient components, is essential for the growth and development of newborn mammals. MicroRNAs (miRNAs) are present in various tissues and body fluids and are selectively packaged inside exosomes, a type of membrane vesicle. Milk exosomes have potential regulatory effects on the growth, development, and immunity of newborn piglets. To explore the differences in milk exosomes related to the breed and milk type, we isolated exosomes from colostrum and mature milk from domestic Bamei pigs and foreign Landrace pigs by using density gradient centrifugation and then characterized them by transmission electron microscopy (TEM) and nanoparticle tracking analysis (NTA). Furthermore, the profiles and functions of miRNAs in the two types of pig milk exosomes were investigated using miRNA-seq and bioinformatics analysis. We identified a total of 1081 known and 2311 novel miRNAs in pig milk exosomes from Bamei and Landrace pigs. These differentially expressed miRNAs (DE-miRNAs) are closely associated with processes such as cell signaling, cell physiology, and immune system development. Functional enrichment analysis showed that DE-miRNA target genes were significantly enriched in endocytosis, the T cell receptor signaling pathway, and the Th17 cell differentiation signaling pathway. The exosomal miRNAs in both the colostrum and mature milk of the two pig species showed significant differences. Based on related signaling pathways, we found that the colostrum of local pig breeds contained more immune-system-development-related miRNAs. This study provides new insights into the possible function of milk exosomal miRNAs in the development of the piglet immune system.

Milk exosomal microRNA profiling identified miR-375 and miR-199-5p for regulation of immune response during subclinical mastitis of crossbred cattle

BACKGROUND

The dairy industry has experienced significant economic losses as a result of mastitis, an inflammatory disease of cows, including both subclinical and clinical cases. Milk exosome microRNAs have gained attention due to their stable and selective wrapping nature, offering potential for the prognosis and diagnosis of bovine mastitis, the most common pathological condition of the mammary gland.

METHODS AND RESULTS

 In the present investigation, the microRNA profile of milk exosomes was explored using high-throughput small RNA sequencing data in sub-clinical mastitic and healthy crossbred Vrindavani cattle. In both groups, 349 microRNAs were identified, with 238 (68.19%) microRNAs co-expressed; however, 35 and 76 distinct microRNAs were found in subclinical mastitic and healthy cattle, respectively. Differential expression analysis revealed 11 microRNAs upregulated, and 18 microRNAs were downregulated in sub-clinical mastitic cattle. The functional annotation of the target genes of differentially expressed known and novel microRNAs including bta-miR-375, bta-miR-199-5p and bta-miR-12030 reveals their involvement in the regulation of immune response and inflammatory mechanisms and could be involved in development of mastitis.

CONCLUSIONS

The analysis of milk exosomal miRNAs cargos hold great promise as an approach to study the underlying molecular mechanisms associated with mastitis in high milk producing dairy cattle. Concurrently, the significantly downregulated miR-375 may upregulate key target genes, including CTLA4, IHH, IRF1, and IL7R. These genes are negative regulators of immune response pathways, which could be associated with impaired inflammatory mechanisms in mammary cells. According to the findings, bta-miR-375 could be a promising biomarker for the development of mastitis in dairy cattle.

Gestational age at birth influences protein and RNA content in human milk extracellular vesicles

Human milk extracellular vesicles (HM EVs) are proposed to protect against disease development in infants. This protection could in part be facilitated by the bioactive EV cargo of proteins and RNA. Notably, mothers birth infants of different gestational ages with unique needs, wherein the EV cargo of HM may diverge. We collected HM from lactating mothers within two weeks of a term or preterm birth. Following purification of EVs, proteins and mRNA were extracted for proteomics and sequencing analyses, respectively. Over 2000 protein groups were identified, and over 8000 genes were quantified. The total number of proteins and mRNA did not differ significantly between the two conditions, while functional bioinformatics of differentially expressed cargo indicated enrichment in immunoregulatory cargo for preterm HM EVs. In term HM EVs, significantly upregulated cargo was enriched in metabolism-related functions. Based on gene expression signatures from HM-contained single cell sequencing data, we proposed that a larger portion of preterm HM EVs are secreted by immune cells, whereas term HM EVs contain more signatures of lactocyte epithelial cells. Proposed differences in EV cargo could indicate variation in mother's milk based on infants' gestational age and provide basis for further functional characterisation.

Periconceptional and Prenatal Exposure to Metals and Extracellular Vesicle and Particle miRNAs in Human Milk: A Pilot Study

Human milk is a rich source of microRNAs (miRNAs), which can be transported by extracellular vesicles and particles (EVPs) and are hypothesized to contribute to maternal-offspring communication and child development. Environmental contaminant impacts on EVP miRNAs in human milk are largely unknown. In a pilot study of 54 mother-child pairs from the New Hampshire Birth Cohort Study, we examined relationships between five metals (arsenic, lead, manganese, mercury, and selenium) measured in maternal toenail clippings, reflecting exposures during the periconceptional and prenatal periods, and EVP miRNA levels in human milk. 798 miRNAs were profiled using the NanoString nCounter platform; 200 miRNAs were widely detectable and retained for downstream analyses. Metal-miRNA associations were evaluated using covariate-adjusted robust linear regression models. Arsenic exposure during the periconceptional and prenatal periods was associated with lower total miRNA content in human milk EVPs (PBonferroni < 0.05). When evaluating miRNAs individually, 13 miRNAs were inversely associated with arsenic exposure, two in the periconceptional period and 11 in the prenatal period (PBonferroni < 0.05). Other metal-miRNA associations were not statistically significant after multiple testing correction (PBonferroni ≥ 0.05). Many of the arsenic-associated miRNAs are involved in lactation and have anti-inflammatory properties in the intestine and tumor suppressive functions in breast cells. Our findings raise the possibility that periconceptional and prenatal arsenic exposure may reduce levels of multiple miRNAs in human milk EVPs. However, larger confirmatory studies, which can apply environmental mixture approaches, evaluate potential effect modifiers of these relationships, and examine possible downstream consequences for maternal and child health and breastfeeding outcomes, are needed.

Identification of Hub Genes and Target miRNAs Crucial for Milk Production in Holstein Friesian Dairy Cattle

Dairy milk production is a quantitative trait that is controlled by many biological and environmental factors. This study employs a network-driven systems approach and clustering algorithm to uncover deeper insights into its genetic associations. We analyzed the GSE33680 dataset from the GEO database to understand the biological importance of milk production through gene expression and modules. In this study, we employed CytoNCA and ClusterONE plugins within Cytoscape for network analysis. Moreover, miRWalk software was utilized to detect miRNAs, and DAVID was employed to identify gene ontology and pathways. The results revealed 140 up-regulated genes and 312 down-regulated genes. In addition, we have identified 91 influential genes and 47 miRNAs that are closely associated with milk production. Through our examination of the network connecting these genes, we have found significant involvement in important biological processes such as calcium ion transit across cell membranes, the BMP signaling pathway, and the regulation of MAPK cascade. The conclusive network analysis further reveals that GAPDH, KDR, CSF1, PYGM, RET, PPP2CA, GUSB, and PRKCA are closely linked to key pathways essential for governing milk production. Various mechanisms can control these genes, making them valuable for breeding programs aiming to enhance selection indexes.

Characterization and profiling of the microRNA in small extracellular vesicles isolated from goat milk samples collected during the first week postpartum

Colostrum contains nutrients, immunoglobulins, and various bioactive compounds such as microRNA (miRNA). Less is known about the temporal changes in miRNA profiles in ruminant milk samples during the first week postpartum. In this study, we characterized and compared the profiles of miRNA in the small extracellular vesicles (sEV) isolated from colostrum (CM, collected immediately after parturition, n = 8) and transition milk (TM, collected 7 d postpartum, n = 8) from eight 1-yr-old Guanzhong dairy goats with a milk yield of approximately 500 kg/year. A total of 192 unique sEV-associated miRNA (transcripts per million >1 at least 4 samples in either CM or TM) were identified in all samples. There were 29 miRNA uniquely identified in the TM samples while no miRNA was uniquely identified in the CM samples. The abundance of the top 10 miRNA accounted for 82.4% ± 4.0% (± SD) of the total abundance, with let-7 families (e.g., let-7a/b/c-5p) being predominant in all samples. The top 10 miRNA were predicted to target 1,008 unique genes that may regulate pathways such as focal adhesion, TGF-β signaling, and axon guidance. The expression patterns of EV miRNA were similar between the 2 sample groups, although the abundance of let-7c-5p and miR-30a-3p was higher, whereas that of let-7i-5p and miR-103-3p was lower in CM than in TM. In conclusion, the core miRNAome identified in the samples from CM and TM may play an important role in cell proliferation, bone homeostasis, and neuronal network formation in newborn goat kids. The lack of differential miRNA expression between the CM and TM samples may be due to a relatively short sampling interval in which diet composition, intake and health status of ewes, and environment were relatively stable.

Milk-derived small extracellular vesicles: a new perspective on dairy nutrition

Milk contains bioactive compounds that have multiple essential benefits. Milk-derived small extracellular vesicles (M-sEVs) have emerged as novel bioactive milk components with various beneficial biological functions and broad applications. The M-sEVs from different mammalian sources have similar composition and bioactive functions. The digestive stability and biocompatibility of the M-sEVs provide a good foundation for their physiological functions. Evidence suggests that M-sEVs promote intestinal, immune, bone, neural, liver, and heart health and show therapeutic effects against cancer, indicating their potential for use in functional foods. In addition, M-sEVs can be developed as natural delivery carriers owing to their superior structural characteristics. Further studies are needed to elucidate the relationship between the specific components and functions of M-sEVs, standardize their extraction processes, and refine relevant clinical trials to advance the future applications of M-sEVs. This review summarizes the structure and composition of M-sEVs isolated from different milk sources and discusses several common extraction methods. Since the introduction of M-sEVs for digestion and absorption, studies have been conducted on their biological functions. Furthermore, we outline the theoretical industrial production route, potential application scenarios of M-sEVs, and the future perspectives of M-sEV research.

Plant and mammalian-derived extracellular vesicles: a new therapeutic approach for the future

Background: In recent years, extracellular vesicles have been recognized as important mediators of intercellular communication through the transfer of active biomolecules (proteins, lipids, and nucleic acids) across the plant and animal kingdoms and have considerable roles in several physiological and pathological mechanisms, showing great promise as new therapeutic strategies for a variety of pathologies. Methods: In this study, we carefully reviewed the numerous articles published over the last few decades on the general knowledge of extracellular vesicles, their application in the therapy of various pathologies, and their prospects as an approach for the future. Results: The recent discovery and characterization of extracellular vesicles (EVs) of diverse origins and biogenesis have altered the current paradigm of intercellular communication, opening up new diagnostic and therapeutic perspectives. Research into these EVs released by plant and mammalian cells has revealed their involvement in a number of physiological and pathological mechanisms, such as embryonic development, immune response, tissue regeneration, and cancer. They are also being studied as potential biomarkers for disease diagnosis and vectors for drug delivery. Conclusion: Nanovesicles represent powerful tools for intercellular communication and the transfer of bioactive molecules. Their molecular composition and functions can vary according to their origin (plant and mammalian), so their formation, composition, and biological roles open the way to therapeutic applications in a variety of pathologies, which is arousing growing interest in the scientific community. Clinical Trial Registration: ClinicalTrials.gov identifier: NCT03608631.

Connecting the dots in the associations between diet, obesity, cancer, and microRNAs

The prevalence of obesity has reached pandemic levels worldwide, leading to a lower quality of life and higher health costs. Obesity is a major risk factor for noncommunicable diseases, including cancer, although obesity is one of the major preventable causes of cancer. Lifestyle factors, such as dietary quality and patterns, are also closely related to the onset and development of obesity and cancer. However, the mechanisms underlying the complex association between diet, obesity, and cancer remain unclear. In the past few decades, microRNAs (miRNAs), a class of small non-coding RNAs, have been demonstrated to play critical roles in biological processes such as cell differentiation, proliferation, and metabolism, highlighting their importance in disease development and suppression and as therapeutic targets. miRNA expression levels can be modulated by diet and are involved in cancer and obesity-related diseases. Circulating miRNAs can also mediate cell-to-cell communications. These multiple aspects of miRNAs present challenges in understanding and integrating their mechanism of action. Here, we introduce a general consideration of the associations between diet, obesity, and cancer and review the current knowledge of the molecular functions of miRNA in each context. A comprehensive understanding of the interplay between diet, obesity, and cancer could be valuable for the development of effective preventive and therapeutic strategies in future.

Comparison of goat and cow milk-derived extracellular vesicle miRNomes

miRNAs present in milk are mainly found in extracellular vesicles (EVs), which are nanosized membrane vesicles released by most of the cell types to ensure intercellular communication. The majority of the studies performed so far on these vesicles have been conducted on human and cow's milk and focused on their miRNA content. The objectives of this study were to profile the miRNA content of purified EVs from five healthy goats and to compare their miRNome to those obtained from five healthy cows, at an early stage of lactation. EV populations were morphologically characterized using Transmission Electron Microscopy and Nanoparticle Tracking Analysis. The presence of EV protein markers checked by Western blotting and the absence of contamination of preparations by milk proteins. The size distribution and concentration of bovine and goat milk-derived EVs were similar. RNA-sequencing were performed, and all sequences were mapped to the cow genome identifying a total of 295 miRNAs. This study reports for the first-time a goat miRNome from milk EVs and its validation using cow miRNomes.

Circadian Rhythm Does Not Affect the miRNA Cargo of Bovine Raw Milk Extracellular Vesicles

Extracellular vesicles (EVs) and their microRNA (miRNA) cargo have been proposed as possible mammary gland health biomarkers in cattle. However, throughout the day, the biologically active milk components, such as miRNAs, may change due to the dynamic nature of milk. The current study aimed to evaluate the circadian fluctuation of milk EVs miRNA cargo to assess the feasibility of milk EVs as future biomarkers for mammary gland health management. Milk from four healthy dairy cows was collected for four consecutive days in the two daily milking sessions in the morning and the evening. The isolated EVs were heterogeneous, intact, and carried the EV protein markers CD9, CD81, and TSG101, as shown by transmission electron microscopy and western blot. The miRNA sequencing results demonstrate that the abundance of miRNA cargo in milk EVs remained stable, unlike other milk components, such as somatic cells, that changed during milking sessions. These findings indicated that the miRNA cargo within milk EVs remains stable irrespective of the time of day, suggesting their potential utility as diagnostic markers for mammary gland health.

Extracellular vesicles and their indispensable roles in pathogenesis and treatment of inflammatory bowel disease: A comprehensive review

Inflammatory bowel disease (IBD) is a global disease with rising incidence worldwide, and its debilitating symptoms and dissatisfactory therapies have brought heavy burdens for patients. Extracellular vesicles (EVs), a heterogeneous population of lipid bilayer membranes containing abundant bioactive molecules, have been indicated to play important roles in the pathogenesis and treatment of many diseases. However, to our knowledge, comprehensive reviews summarizing the various roles of diverse source-derived EVs in the pathogenesis and treatment of IBD are still lacking. This review, not only summarizes the EV characteristics, but also focuses on the multiple roles of diverse EVs in IBD pathogenesis and their treatment potential. In addition, hoping to push forward the research frontiers, we point out several challenges that the researchers are faced, about EVs in current IBD research and future therapeutic applications. We also put forward our prospects on future exploration regarding EVs in IBD treatment, including developing IBD vaccines and paying more attention on apoptotic vesicles. This review is aimed to enrich the knowledge on the indispensable roles of EVs in IBD pathogenesis and treatment, providing ideas and reference for future therapeutic strategy for IBD treatment.

Regulation of adipogenesis by exosomal milk miRNA

Milk is a rich source of miRNA packaged in exosomes. Evidence for the systemic uptake and tissue distribution of milk exosomes was reported in newborn and adult humans and animals. Breastfeeding in infants was associated with a reduced risk of obesity. Numerous adipogenesis-related miRNAs have been detected in human milk exosomes. It has been demonstrated that ingested exosomal milk miRNAs may alter gene expression in offspring to regulate their metabolism and growth. In humans, consumption of other species' milk, such as cows and goats, is continued through adulthood. Since miRNAs are conserved, the concern of cross-species transfer of adipogenic miRNA has been raised in recent years, and the increase in obesity worldwide was attributed partially to dairy milk consumption by humans. However, evidence is still weak. Research emphasizes the need for an adequate number of exosomal milk's miRNAs to reach the target cell for biological action to be achieved. It was reported that obese women's milk had less miRNA-148a and miRNA-30b, which may affect the fat acquisition of their babies. Some exosomal milk miRNAs, such as miRNA-29, miRNA-148, miRNA-30b and miRNA-125b, may have epigenetic effects on milk recipients. Moreover, the ability of milk exosomes to cross the gastrointestinal barrier makes them a promising oral drug delivery tool. Yet, exosomes may also be tagged with specific ligands which target certain tissues. Thus, milk exosomes can be engineered and loaded with certain miRNAs responsible for adipocyte differentiation, conversion, or browning. Modifications in the miRNA cargo of exosomes can benefit human health and be an alternative to traditional drugs.

Potential Pathogenic Impact of Cow’s Milk Consumption and Bovine Milk-Derived Exosomal MicroRNAs in Diffuse Large B-Cell Lymphoma

Epidemiological evidence supports an association between cow’s milk consumption and the risk of diffuse large B-cell lymphoma (DLBCL), the most common non-Hodgkin lymphoma worldwide. This narrative review intends to elucidate the potential impact of milk-related agents, predominantly milk-derived exosomes (MDEs) and their microRNAs (miRs) in lymphomagenesis. Upregulation of PI3K-AKT-mTORC1 signaling is a common feature of DLBCL. Increased expression of B cell lymphoma 6 (BCL6) and suppression of B lymphocyte-induced maturation protein 1 (BLIMP1)/PR domain-containing protein 1 (PRDM1) are crucial pathological deviations in DLBCL. Translational evidence indicates that during the breastfeeding period, human MDE miRs support B cell proliferation via epigenetic upregulation of BCL6 (via miR-148a-3p-mediated suppression of DNA methyltransferase 1 (DNMT1) and miR-155-5p/miR-29b-5p-mediated suppression of activation-induced cytidine deaminase (AICDA) and suppression of BLIMP1 (via MDE let-7-5p/miR-125b-5p-targeting of PRDM1). After weaning with the physiological termination of MDE miR signaling, the infant’s BCL6 expression and B cell proliferation declines, whereas BLIMP1-mediated B cell maturation for adequate own antibody production rises. Because human and bovine MDE miRs share identical nucleotide sequences, the consumption of pasteurized cow’s milk in adults with the continued transfer of bioactive bovine MDE miRs may de-differentiate B cells back to the neonatal “proliferation-dominated” B cell phenotype maintaining an increased BLC6/BLIMP1 ratio. Persistent milk-induced epigenetic dysregulation of BCL6 and BLIMP1 expression may thus represent a novel driving mechanism in B cell lymphomagenesis. Bovine MDEs and their miR cargo have to be considered potential pathogens that should be removed from the human food chain.

Breast milk microRNAs: Potential players in oral tolerance development

Breast milk is an essential source of nutrition and hydration for the infant. In addition, this highly complex biological fluid contains numerous immunologically active factors such as microorganisms, immunoglobulins, cytokines and microRNAs (miRNAs). Here, we set out to predict the function of the top 10 expressed miRNAs in human breast milk, focusing on their relevance in oral tolerance development and allergy prevention in the infant. The top expressed miRNAs in human breast milk were identified on basis of previous peer-reviewed studies gathered from a recent systematic review and an updated literature search. The miRNAs with the highest expression levels in each study were used to identify the 10 most common miRNAs or miRNA families across studies and these were selected for subsequent target prediction. The predictions were performed using TargetScan in combination with the Database for Annotation, Visualization and Integrated Discovery. The ten top expressed miRNAs were: let-7-5p family, miR-148a-3p, miR-30-5p family, miR-200a-3p + miR-141-3p, miR-22-3p, miR-181-5p family, miR-146b-5p, miR-378a-3p, miR-29-3p family, miR-200b/c-3p and miR-429-3p. The target prediction identified 3,588 potential target genes and 127 Kyoto Encyclopedia of Genes and Genomes pathways; several connected to the immune system, including TGF-b and T cell receptor signaling and T-helper cell differentiation. This review highlights the role of breast milk miRNAs and their potential contribution to infant immune maturation. Indeed, breast milk miRNAs seem to be involved in several pathways that influence oral tolerance development.

Regulatory Role of microRNA of Milk Exosomes in Mastitis of Dairy Cows

The aim of this study was to compare the cargos of miRNA in exosomes isolated from the milk of healthy (H) cows, cows at risk of mastitis (ARM), and cows with subclinical mastitis (SCM). Based on the number of somatic cells and the percentage of polymorphonuclear cells, 10 cows were assigned to group H, 11 to group ARM, and 11 to group SCM. After isolating exosomes in milk by isoelectric precipitation and ultracentrifugation, the extracted RNA was sequenced to 50 bp long single reads, and these were mapped against Btau_5.0.1. The resulting 225 miRNAs were uploaded to the miRNet suite, and target genes for Bos taurus were identified based on the miRTarBase and miRanda databases. The list of differentially expressed target genes resulting from the comparisons of the three groups was enriched using the Function Explorer of the Kyoto Encyclopedia of Genes and Genomes. A total of 38, 18, and 12 miRNAs were differentially expressed (DE, p < 0.05) in the comparisons of H vs. ARM, ARM vs. SCM, and H vs. SCM, respectively. Only 1 DE miRNA was shared among the three groups (bta-mir-221), 1 DE miRNA in the H vs. SCM comparison, 9 DE miRNAs in the ARM vs. SCM comparison, and 21 DE miRNAs in the H vs. ARM comparison. A comparison of the enriched pathways of target genes from the H, SCM, and ARM samples showed that 19 pathways were differentially expressed in the three groups, while 56 were expressed in the H vs. SCM comparison and 57 in the H vs. ARM comparison. Analyzing milk exosome miRNA cargos can be considered as a promising approach to study the complex molecular machinery set in motion in response to mastitis in dairy cows.

Exploring Purification Methods of Exosomes from Different Biological Samples

Objective

Exosomes were extracted from a variety of biological samples using several different purification processes, and our goal was to determine which method and sample were the most effective for exosome extraction.

Methods

We used ExoQuick-TC combined with ultrafiltration to separate and purify exosomes from the supernatant of gastric cancer cells, while we used the ExoQuick kit and ultracentrifugation to purify exosomes from human serum samples. Furthermore, exosomes were isolated and purified from human urine samples by diafiltration and from postparturition human breast milk samples by the filtration-polyethylene glycol precipitation method. The isolated exosomes were morphologically analyzed using a transmission electron microscope, the particle size was measured by NanoSight, and the protein content was analyzed by western blotting.

Results

The isolated exosomes showed an obvious cup holder shape, with a clear outline and typical exosome morphological characteristics. The sizes of exosomes derived from gastric cancer cell supernatant, serum, urine, and milk were 65.8 ± 26.9 nm, 87.6 ± 50.9 nm, 197.5 ± 55.2 nm, and 184.1 ± 68.7 nm, respectively. Western blot results showed that CD9 and TSG101 on the exosomes were expressed to varying degrees based on the exosome source. Exosome abundance was higher in the serum, urine, and breast milk than in the supernatant. It is suggested that its exosomes can be extracted to obtain an excellent potential biological source of exosomes.

Conclusion

In this study, the extraction and separation methods of foreign bodies from different biological samples were obtained, and it was found that human breast milk was a potential excellent material for administration because of its high abundance.

Updated Methods of Extracellular Vesicles Isolation

Extracellular vesicles (EVs) are considered as cargo and mediate intercellular communication. As natural biological nanoparticles, EVs can be secreted by almost all kinds of cells and exist in biofluids such as milk, urine, blood, etc. In the past decades, several methods have been utilized to isolate EVs from cell culture medium, biofluids, and tissues. Here in this chapter, we summarized conventional and novel methods and fundamental procedures of EVs extraction and purification from different biofluids (plasma, urine, milk, and saliva) and tissues (brain, intestinal tissue, muscles, and heart). The present section also discusses how to choose appropriate methods to extract EVs from tissues based on downstream analysis. This chapter will expand the horizons of EVs isolation and purification from different mediums.

Intracellular Compartmentalization: A Key Determinant of MicroRNA Functions

Being an integral part of the eukaryotic transcriptome, miRNAs are regarded as vital regulators of diverse developmental and physiological processes. Clearly, miRNA activity is kept in check by various regulatory mechanisms that control their biogenesis and decay pathways. With the increasing technical depth of RNA profiling technologies, novel insights have unravelled the spatial diversity exhibited by miRNAs inside a cell. Compartmentalization of miRNAs adds complexity to the regulatory circuits of miRNA expression, thereby providing superior control over the miRNA function. This review provides a bird's eye view of miRNAs expressed in different subcellular locations, thus affecting the gene regulatory pathways therein. Occurrence of miRNAs in diverse intracellular locales also reveals various unconventional roles played by miRNAs in different cellular organelles and expands the scope of miRNA functions beyond their traditionally known repressive activities.

Extracellular Vesicles from Animal Milk: Great Potentialities and Critical Issues

Other than representing the main source of nutrition for newborn mammals, milk delivers a sophisticated signaling system from mother to child that promotes postnatal health. The bioactive components transferred through the milk intake are important for the development of the newborn immune system and include oligosaccharides, lactoferrin, lysozyme, α-La, and immunoglobulins. In the last 15 years, a pivotal role in this mother-to-child exchange has been attributed to extracellular vesicles (EVs). EVs are micro- and nanosized structures enclosed in a phospholipidic double-layer membrane that are produced by all cell types and released in the extracellular environment, reaching both close and distant cells. EVs mediate the intercellular cross-talk from the producing to the receiving cell through the transfer of molecules contained within them such as proteins, antigens, lipids, metabolites, RNAs, and DNA fragments. The complex cargo can induce a wide range of functional modulations in the recipient cell (i.e., anti-inflammatory, immunomodulating, angiogenetic, and pro-regenerative modulations) depending on the type of producing cells and the stimuli that these cells receive. EVs can be recovered from every biological fluid, including blood, urine, bronchoalveolar lavage fluid, saliva, bile, and milk, which is one of the most promising scalable vesicle sources. This review aimed to present the state-of-the-art of animal-milk-derived EV (mEV) studies due to the exponential growth of this field. A focus on the beneficial potentialities for human health and the issues of studying vesicles from milk, particularly for the analytical methodologies applied, is reported.

Milk-Derived miR-22-3p Promotes Proliferation of Human Intestinal Epithelial Cells (HIECs) by Regulating Gene Expression

MicroRNA (miRNA) is small non-coding RNA involved in gene silencing and post-transcriptional regulation of gene expression. Milk exosomes are microvesicles containing microRNAs (miRNAs). miR-22-3p (miR-22) is plentiful in human milk exosomes and may contribute to intestinal development since milk exosomes and microRNAs are resistant to gastrointestinal digestion in infants. After miR-22 mimics were transfected to human intestinal crypt-like epithelial cells (HIECs) using Lipofectamine for 24 h, RNA was isolated for microarray assay. Microarray results show that miR-22 markedly regulates gene expression, and the roles of miR-22 include promotion of proliferation, regulation of immune functions, and inhibition of apoptosis. Based on the microarray results and miR-22 predicted target genes, CCAAT/enhancer-binding protein δ (C/EBPδ) may be an important direct target of miR-22. C/EBPδ is a transcription factor that regulates numerous biological processes including cell proliferation. In miR-22 transfected HIECs, expression of the C/EBPδ gene was significantly inhibited. Silencing of the C/EBPδ gene by siRNA resulted in increased proliferation of HIECs. A luciferase assay showed that miR-22 specifically binds to the 3'-untranslated region of C/EBPδ mRNA. In summary, milk-derived miR-22 promotes intestinal proliferation by modifying gene expression, and C/EBPδ may be an important target for miR-22 involved in this effect.

Extracellular vesicle miRNAs in breast milk of obese mothers

Background

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) are expected to interact with other organs in breastfed infants and modify the gene expression of recipient cells using miRNAs. Maternal pre-pregnancy BMI is a critical factor influencing the composition of breast milk. Thus, in mothers with obesity, miRNAs in bEVs can be altered, 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 mothers with obesity and their potential impact on breastfed infants.

Methods

We recruited healthy nursing mothers who were either of normal weight (BMI < 25) or with obesity (BMI ≥ 30) based on their pre-pregnancy BMI, and delivered a singleton baby in the prior 6 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 differentially expressed miRNAs in bEVs of mothers with obesity compared to mothers of normal weight.

Results

We included 65 nursing mothers: 47 of normal weight and 18 with obesity based on pre-pregnancy BMI. After bEV isolation, we confirmed the expression of various EV markers. Out of 37 EV markers, CD326 (EpCaM) was the most highly expressed in bEVs. The most abundant miRNAs in bEVs include miR-30b-5p, miR-4454, miR-494-3p, and let-7 miRNAs. Target genes of the top 10 miRNAs were associated with cancer, prolactin pathway, EGFR, ErbB, and FoxO signaling pathway. In bEVs of mothers with obesity, 19 miRNAs were differentially expressed (adjusted p < 0.05 cut-off), which include miR-575, miR-630, miR-642a-3p, and miR-652-5p. These miRNAs and their target genes were associated with neurological diseases and psychological disorders.

Conclusion

In this study, we characterized bEVs and demonstrated altered miRNAs in bEVs of mothers with obesity 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.

Milk Exosomal microRNAs: Postnatal Promoters of β Cell Proliferation but Potential Inducers of β Cell De-Differentiation in Adult Life

Pancreatic β cell expansion and functional maturation during the birth-to-weaning period is driven by epigenetic programs primarily triggered by growth factors, hormones, and nutrients provided by human milk. As shown recently, exosomes derived from various origins interact with β cells. This review elucidates the potential role of milk-derived exosomes (MEX) and their microRNAs (miRs) on pancreatic β cell programming during the postnatal period of lactation as well as during continuous cow milk exposure of adult humans to bovine MEX. Mechanistic evidence suggests that MEX miRs stimulate mTORC1/c-MYC-dependent postnatal β cell proliferation and glycolysis, but attenuate β cell differentiation, mitochondrial function, and insulin synthesis and secretion. MEX miR content is negatively affected by maternal obesity, gestational diabetes, psychological stress, caesarean delivery, and is completely absent in infant formula. Weaning-related disappearance of MEX miRs may be the critical event switching β cells from proliferation to TGF-β/AMPK-mediated cell differentiation, whereas continued exposure of adult humans to bovine MEX miRs via intake of pasteurized cow milk may reverse β cell differentiation, promoting β cell de-differentiation. Whereas MEX miR signaling supports postnatal β cell proliferation (diabetes prevention), persistent bovine MEX exposure after the lactation period may de-differentiate β cells back to the postnatal phenotype (diabetes induction).

Investigation of the transability of dietary small non-coding RNAs to animals

Our daily diet not only provides essential nutrients needed for survival and growth but also supplies bioactive ingredients to promote health and prevent disease. Recent studies have shown that exogenous microRNAs (miRNAs), xenomiRs, may enter the consumer’s body through dietary intake and regulate gene expression. This fascinating phenomenon suggests that xenomiRs can act as a new class of bioactive substances associated with mammalian systems. In contrast, several studies have failed to detect xenomiRs in consumers and reported that the observed diet-derived miRNAs in the previous studies can be related to the false positive effects of experiments. This discrepancy can be attributed to the potential artifacts related to the process of experiments, small sample size, and inefficient bioinformatics pipeline. Since this hypothesis is not generally accepted yet, more studies are required. Here, a stringent and reliable bioinformatics pipeline was used to analyze 133 miRNA sequencing data from seven different studies to investigate this phenomenon. Generally, our results do not support the transfer of diet-derived miRNAs into the animal/human tissues in every situation. Briefly, xenomiRs were absent from most samples, and also, their expressions were very low in the samples where they were present, which is unlikely to be sufficient to regulate cell transcripts. Furthermore, this study showed that the possibility of miRNAs being absorbed through animals’ diets and thus influencing gene expression during specific periods of biological development is not inconceivable. In this context, our results were in agreement with the theory of the transfer of small RNAs under certain conditions and periods as xenomiRs were found in colostrum which may modulate infants’ immune systems via post-transcriptional regulation. These findings provide evidence for the selective absorption of diet-derived small RNAs, which need to be investigated in future studies to shed light on the mechanisms underlying the transference of diet-derived miRNAs.

Extracellular Vesicles—Oral Therapeutics of the Future

Considered an artifact just after discovery, the possibility of oral delivery of extracellular vesicles (EVs) and their functional cargos has recently gained much research attention. EVs from various sources, including edible plants, milk, bacteria and mammalian cells, have emerged as a platform for miRNA and drug delivery that seem to induce the expected immune effects locally and in distant tissues after oral administration. Such a possibility greatly expands the clinical applicability of EVs. The present review summarizes research findings that either support or deny the biological/therapeutical activity of orally administered EVs and their role in cross-species and cross-kingdom signaling.

Theragnostic Applications of Mammal and Plant-Derived Extracellular Vesicles: Latest Findings, Current Technologies, and Prospects

The way cells communicate is not fully understood. However, it is well-known that extracellular vesicles (EVs) are involved. Researchers initially thought that EVs were used by cells to remove cellular waste. It is now clear that EVs function as signaling molecules released by cells to communicate with one another, carrying a cargo representing the mother cell. Furthermore, these EVs can be found in all biological fluids, making them the perfect non-invasive diagnostic tool, as their cargo causes functional changes in the cells upon receiving, unlike synthetic drug carriers. EVs last longer in circulation and instigate minor immune responses, making them the perfect drug carrier. This review sheds light on the latest development in EVs isolation, characterization and, application as therapeutic cargo, novel drug loading techniques, and diagnostic tools. We also address the advancement in plant-derived EVs, their characteristics, and applications; since plant-derived EVs only recently gained focus, we listed the latest findings. Although there is much more to learn about, EV is a wide field of research; what scientists have discovered so far is fascinating. This paper is suitable for those new to the field seeking to understand EVs and those already familiar with it but wanting to review the latest findings.

The Therapeutic Potential of Milk Extracellular Vesicles on Colorectal Cancer

Colorectal cancer remains one of the leading prevalent cancers in the world and is the fourth most common cause of death from cancer. Unfortunately, the currently utilized chemotherapies fail in selectively targeting cancer cells and cause harm to healthy cells, which results in profound side effects. Researchers are focused on developing anti-cancer targeted medications, which is essential to making them safer, more effective, and more selective and to maximizing their therapeutic benefits. Milk-derived extracellular vesicles (EVs) from camels and cows have attracted much attention as a natural substitute product that effectively suppresses a wide range of tumor cells. This review sheds light on the biogenesis, methods of isolation, characterization, and molecular composition of milk EVs as well as the therapeutic potentials of milk EVs on colorectal cancer.

Extracellular vesicles derived from mesenchymal stem/stromal cells: The regenerative impact in liver diseases

Liver dysfunctions are classified into acute and chronic diseases, which comprise a heterogeneous group of pathological features and a high mortality rate. Liver transplantation remains the gold-standard therapy for most liver diseases, with concomitant limitations related to donor organ shortage and lifelong immunosuppressive therapy. A concept in liver therapy intends to overcome these limitations based on the secreted extracellular vesicles (EVs; microvesicles and exosomes) by mesenchymal stem/stromal cells (MSCs). A significant number of studies have shown that factors released by MSCs could induce liver repair and ameliorate systemic inflammation through paracrine effects. It is well known that this paracrine action is based not only on the secretion of cytokines and growth factors but also on EVs, which regulate pathways associated with inflammation, hepatic fibrosis, integrin-linked protein kinase signaling, and apoptosis. Herein, we extensively discuss the differential effects of MSC-EVs on different liver diseases and on cellular and animal models and address the complex molecular mechanisms involved in the therapeutic potential of EVs. In addition, we cover the crucial information regarding the type of molecules contained in MSC-EVs that can be effective in the context of liver diseases. In conclusion, outcomes on MSC-EV-mediated therapy are expected to lead to an innovative, cell-free, noninvasive, less immunogenic, and nontoxic alternative strategy for liver treatment and to provide important mechanistic information on the reparative function of liver cells.

Maternal immune protection against infectious diseases

The maternal immune system protects developing offspring against pathogens before birth via transplacental transfer and after birth through secreted milk. This transferred maternal immunity influences each generation's susceptibility to infections and responsiveness to immunization. Thus, boosting immunity in the maternal-neonatal dyad is a potentially valuable public health strategy. Additionally, at critical times during fetal and postnatal development, environmental factors and immune stimuli influence immune development. These "windows of opportunity" offer a chance to identify both risk and protective factors that promote long-term health and limit disease. Here, we review pre- and postpartum maternal immune factors that protect against infectious agents in offspring and how they may shape the infant's immune landscape over time. Additionally, we discuss the influence of maternal immunity on the responsiveness to immunization in early life. Lastly, when maternal factors are insufficient to prevent neonatal infectious diseases, we discuss pre- and postnatal therapeutic strategies for the maternal-neonatal dyad.

Extracellular vesicles in human milk

PURPOSE OF REVIEW

Milk-derived extracellular vesicles (MDEVs) are nanovesicles that carry microRNA (miRNA) DNA, RNA, proteins and lipids. MDEVs have a potential of therapeutic targets, based on their properties and cargo profile. The present review summarizes recent studies on MDEVs, their cargo and potential role in mammalian development.

RECENT FINDINGS

The detailed characterization of their miRNA cargo leads to the conclusion of their potential importance in the regulation of gene expression, immune function, development and infant growth.While their miRNAs are important regulatory elements and their profile expression was characterized in various mammalian milk sources, little is known about their effect on infant health and development. MiRNA activity in breast milk is likely influenced by the overall ecosystem of the early environment, including maternal characteristics, behaviors, and health.

SUMMARY

MDEVs may have an important role in early child development and infant future health. Understanding benefits of MDEVs characteristics have potential role on gut maturation, immune system development and the prevention of metabolic disorders.

Human Breast Milk: From Food to Active Immune Response With Disease Protection in Infants and Mothers

Breastfeeding is associated with long-term wellbeing including low risks of infectious diseases and non-communicable diseases such as asthma, cancer, autoimmune diseases and obesity during childhood. In recent years, important advances have been made in understanding the human breast milk (HBM) composition. Breast milk components such as, non-immune and immune cells and bioactive molecules, namely, cytokines/chemokines, lipids, hormones, and enzymes reportedly play many roles in breastfed newborns and in mothers, by diseases protection and shaping the immune system of the newborn. Bioactive components in HBM are also involved in tolerance and appropriate inflammatory response of breastfed infants if necessary. This review summarizes the current literature on the relationship between mother and her infant through breast milk with regard to disease protection. We will shed some light on the mechanisms underlying the roles of breast milk components in the maintenance of health of both child and mother.

Testing the effects of processing on donor human Milk: Analytical methods

Holder pasteurization is the current recommended method for donor human milk treatment. This method effectively eliminates most life-threatening contaminants in donor milk, but it also greatly reduces some of its biological properties. Consequently, there is a growing interest for developing novel processing methods that can ensure both microbial inactivation and a higher retention of the functional components of donor milk. Our aim was to offer a comprehensive overview of the analytical techniques available for the evaluation of such methods. To suggest an efficient workflow for the analysis of processed donor milk, a safety analytical panel as well as a nutritional value and functionality analytical panel are discussed, together with the principles, benefits, and drawbacks of the available techniques. Concluding on the suitability of a novel method requires a multifactorial approach which can be achieved by a combination of analytical targets and by using complementary assays to cross-validate the obtained results.

Beneficial Effects of Bovine Milk Exosomes in Metabolic Interorgan Cross-Talk

Extracellular vesicles are membrane-enclosed secreted vesicles involved in cell-to-cell communication processes, identified in virtually all body fluids. Among extracellular vesicles, exosomes have gained increasing attention in recent years as they have unique biological origins and deliver different cargos, such as nucleic acids, proteins, and lipids, which might mediate various health processes. In particular, milk-derived exosomes are proposed as bioactive compounds of breast milk, which have been reported to resist gastric digestion and reach systemic circulation, thus being bioavailable after oral intake. In the present manuscript, we critically discuss the available evidence on the health benefits attributed to milk exosomes, and we provide an outlook for the potential future uses of these compounds. The use of milk exosomes as bioactive ingredients represents a novel avenue to explore in the context of human nutrition, and they might exert important beneficial effects at multiple levels, including but not limited to intestinal health, bone and muscle metabolism, immunity, modulation of the microbiota, growth, and development.

Bovine colostrum derived-exosomes prevent dextran sulfate sodium-induced intestinal colitis via suppression of inflammation and oxidative stress

Despite the rise in the global burden of inflammatory bowel disease, there is a lack of safe and effective therapies that can meet the needs of clinical patients. In this study, we investigated the beneficial effects of bovine milk, especially colostrum-derived exosomes (Col-exo) in a murine model of ulcerative colitis induced by dextran sodium sulfate (DSS). Col-exo activated the proliferation of colonic epithelial cells and macrophages, and created an environment to relieve inflammation by effectively removing reactive oxygen species and regulating the expression of immune cytokines. Besides, Col-exo could pass through the gastrointestinal tract intact and efficiently deliver bioactive cargoes to the stomach, small intestine, and colon. Our results showed that oral gavage of Col-exo can alleviate colitis symptoms including weight loss, gastrointestinal bleeding, and chronic diarrhea by modulating intestinal inflammatory immune responses. Overall, bovine colostrum-derived exosomes with excellent structural and functional stability may offer great potential as natural therapeutics for the recovery of colitis.

Bovine Milk-Derived Extracellular Vesicles Inhibit Catabolic and Inflammatory Processes in Cartilage from Osteoarthritis Patients

SCOPE

Data from the Osteoarthritis Initiative shows that females who drink milk regularly have less joint cartilage loss and OA progression, but the biologic mechanism is unclear. Bovine milk is a rich source of extracellular vesicles (EVs), which are small phospholipid bilayer bound structures that facilitate intercellular communication. In this study, the authors aim to evaluate whether these EVs may have the capacity to protect cartilage from osteoarthritis patients, ex vivo, by directly effecting chondrocytes.

METHODS AND RESULTS

Human cartilage explants are exposed to cow's milk-derived EVs (CMEVs), which results in reduced sulfated glycosaminoglycan release and inhibition of metalloproteinase-1 expression. Incubation of articular chondrocytes with CMEVs also effectively reduces expression of cartilage destructive enzymes (ADAMTS5, MMPs), which play key roles in the disease progression. In part, these findings are attributed to the presence of TGFβ on these vesicles, and in addition, a possible role is reserved for miR-148a, which is functionally transferred by CMEVs.

CONCLUSION

These findings highlight the therapeutic potential of local CMEV delivery in osteoarthritic joints, where inflammatory and catabolic mediators are responsible for joint pathology. CMEVs are carriers of both TGFβ and miR-148a, two essential regulators for maintaining chondrocyte homeostasis and protection against cartilage destruction.

Identification of Bovine miRNAs with the Potential to Affect Human Gene Expression

Milk and other products from large mammals have emerged during human evolution as an important source of nutrition. Recently, it has been recognized that exogenous miRNAs (mRNA inhibited RNA) contained in milk and other tissues of the mammalian body can enter the human body, which in turn have the ability to potentially regulate human metabolism by affecting gene expression. We studied for exogenous miRNAs from Bos taurus that are potentially contain miRNAs from milk and that could act postprandially as regulators of human gene expression. The interaction of 17,508 human genes with 1025 bta-miRNAs, including 245 raw milk miRNAs was studied. The milk bta-miR-151-5p, bta-miR-151-3p, bta-miRNA-320 each have 11 BSs (binding sites), and bta-miRNA-345-5p, bta-miRNA-614, bta-miRNA-1296b and bta-miRNA-149 has 12, 14, 15 and 26 BSs, respectively. The bta-miR-574-5p from cow’s milk had 209 human genes in mRNAs from one to 25 repeating BSs. We found 15 bta-miRNAs that have 100% complementarity to the mRNA of 13 human target genes. Another 12 miRNAs have BSs in the mRNA of 19 human genes with 98% complementarity. The bta-miR-11975, bta-miR-11976, and bta-miR-2885 BSs are located with the overlap of nucleotide sequences in the mRNA of human genes. Nucleotide sequences of BSs of these miRNAs in 5′UTR mRNA of human genes consisted of GCC repeats with a total length of 18 nucleotides (nt) in 18 genes, 21 nt in 11 genes, 24 nt in 14 genes, and 27–48 nt in nine genes. Nucleotide sequences of BSs of bta-miR-11975, bta-miR-11976, and bta-miR-2885 in CDS mRNA of human genes consisted of GCC repeats with a total length of 18 nt in 33 genes, 21 nt in 13 genes, 24 nt in nine genes, and 27–36 nt in 11 genes. These BSs encoded polyA or polyP peptides. In only one case, the polyR (SLC24A3 gene) was encoded. The possibility of regulating the expression of human genes by exogenous bovine miRNAs is discussed.