MicroRNA Milk Exosomes: From Cellular Regulator to Genomic Marker

Recent development of carrier materials in anthocyanins encapsulation applications: A comprehensive literature review

Anthocyanins are natural polyphenols belonging to the flavonoid family that possess a variety of putative health benefits when consumed in a balanced diet. However, applications of anthocyanins in, for example, functional foods are limited due to poor stability, degradation, and low transmembrane efficiency. To maintain bioactivities of anthocyanins and optimize their use, various carrier materials have been developed. Here, we reviewed the uses of the different carrier materials (organic/inorganic, micro/nano) for anthocyanin encapsulation and delivery over the past five years. The performance of different materials and interactions between anthocyanins and these materials are described. Lastly, we give our perspective on the future development trend of anthocyanin encapsulation strategies.

Extracellular Vesicles Derived from Selenium-Deficient MAC-T Cells Aggravated Inflammation and Apoptosis by Triggering the Endoplasmic Reticulum (ER) Stress/PI3K-AKT-mTOR Pathway in Bovine Mammary Epithelial Cells

Selenium (Se) deficiency disrupts intracellular REDOX homeostasis and severely deteriorates immune and anti-inflammatory function in high-yielding periparturient dairy cattle. To investigate the damage of extracellular vesicles derived from Se-deficient MAC-T cells (SeD-EV) on normal mammary epithelial cells, an in vitro model of Se deficiency was established. Se-deficient MAC-T cells produced many ROS, promoting apoptosis and the release of inflammatory factors. Extracellular vesicles were successfully isolated by ultrahigh-speed centrifugation and identified by transmission electron microscopy, particle size analysis, and surface markers (CD63, CD81, HSP70, and TSG101). RNA sequencing was performed on exosomal RNA. A total of 9393 lncRNAs and 63,155 mRNAs transcripts were identified in the SeC and SeD groups, respectively, of which 126 lncRNAs and 955 mRNAs were differentially expressed. Furthermore, SeD-EV promoted apoptosis of normal MAC-T cells by TUNEL analysis. SeD-EV significantly inhibited Bcl-2, while Bax and Cleaved Caspase3 were greatly increased. Antioxidant capacity (CAT, T-AOC, SOD, and GSH-Px) was inhibited in SeD-EV-treated MAC-T cells. Additionally, p-PERK, p-eIF2α, ATF4, CHOP, and XBP1 were all elevated in MAC-T cells supplemented with SeD-EV. In addition, p-PI3K, p-Akt, and p-mTOR were decreased strikingly by SeD-EV. In conclusion, SeD-EV caused oxidative stress, thus triggering apoptosis and inflammation through endoplasmic reticulum stress and the PI3K-Akt-mTOR signaling pathway, which contributed to explaining the mechanism of Se deficiency causing mastitis.

Genomic and Phenotypic Udder Evaluation for Dairy Cattle Selection: A Review

The traditional point of view regarding dairy cattle selection has been challenged by recent genomic studies indicating that livestock productivity prediction can be redefined based on the evaluation of genomic and phenotypic data. Several studies that included different genomic-derived traits only indicated that interactions among them or even with conventional phenotypic evaluation criteria require further elucidation. Unfortunately, certain genomic and phenotypic-derived traits have been shown to be secondary factors influencing dairy production. Thus, these factors, as well as evaluation criteria, need to be defined. Owing to the variety of genomic and phenotypic udder-derived traits which may affect the modern dairy cow functionality and conformation, a definition of currently important traits in the broad sense is indicated. This is essential for cattle productivity and dairy sustainability. The main objective of the present review is to elucidate the possible relationships among genomic and phenotypic udder evaluation characteristics to define the most relevant traits related to selection for function and conformation in dairy cattle. This review aims to examine the potential impact of various udder-related evaluation criteria on dairy cattle productivity and explore how to mitigate the adverse effects of compromised udder conformation and functionality. Specifically, we will consider the implications for udder health, welfare, longevity, and production-derived traits. Subsequently, we will address several concerns covering the application of genomic and phenotypic evaluation criteria with emphasis on udder-related traits in dairy cattle selection as well as its evolution from origins to the present and future prospects.

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.

Milk exosomes: an oral drug delivery system with great application potential

Exosomes are extracellular vesicles with the smallest diameter, usually divided into cellular sources and body fluid sources. Due to their special properties different from cell-derived exosomes, the application of milk exosomes as an oral drug delivery system has increased greatly. This article introduces the physical and chemical properties of exosomes, separation technology, dyeing and labeling technology, targeted modification technology, and the application of milk exosomes in drug loading and disease therapies.

MicroRNAs in Ruminants and Their Potential Role in Nutrition and Physiology

The knowledge of how diet choices, dietary supplements, and feed intake influence molecular mechanisms in ruminant nutrition and physiology to maintain ruminant health, is essential to attain. In the present review, we focus on the role of microRNAs in ruminant health and disease; additionally, we discuss the potential of circulating microRNAs as biomarkers of disease in ruminants and the state of technology for their detection, also considering the major difficulties in the transition of biomarker development from bench to clinical practice. MicroRNAs are an inexhaustible class of endogenous non-protein coding small RNAs of 18 to 25 nucleotides that target either the 3' untranslated (UTR) or coding region of genes, ensuring a tight post-transcriptionally controlled regulation of gene expression. The development of new "omics" technologies facilitated a fresh perspective on the nutrition-to-gene relationship, incorporating more extensive data from molecular genetics, animal nutrition, and veterinary sciences. MicroRNAs might serve as important regulators of metabolic processes and may present the inter-phase between nutrition and gene regulation, controlled by the diet. The development of biomarkers holds the potential to revolutionize veterinary practice through faster disease detection, more accurate ruminant health monitoring, enhanced welfare, and increased productivity. Finally, we summarize the latest findings on how microRNAs function as biomarkers, how technological paradigms are reshaping this field of research, and how platforms are being used to identify novel biomarkers. Numerous studies have demonstrated a connection between circulating microRNAs and ruminant diseases such as mastitis, tuberculosis, foot-and-mouth disease, fasciolosis, and metabolic disorders. Therefore, the identification and analysis of a small number of microRNAs can provide crucial information about the stage of a disease, etiology, and prognosis.

Suppression of milk-derived miR-148a caused by stress plays a role in the decrease in intestinal ZO-1 expression in infants

BACKGROUND & AIMS

Milk-derived miR-148a-3p (miR-148a), which is abundant in breast milk, has been shown to be associated with the development of infants' intestines. Although it is well known that stress during lactation changes milk constituents in terms of lipid and protein, no studies have examined the influence of stress on miR-148a expression in breast milk. The objective of this study is to investigate the relationship between stress and miR-148a expression in milk, and to evaluate whether the changes in milk-derived miR-148a expression-caused by the mother's exposure to stress-influence intestinal ZO-1 expression in infants.

METHODS

The participants of this study were healthy Japanese women who were nursing. Psychological stress evaluation of the subjects was conducted using a short form of the Profile of Mood State Second Edition-Adult (POMS-2). Additionally, miR-148a expressions in restraint stressed nursing mice were investigated using quantitative real-time PCR. The levels of a tight junction protein zonula occludens-1 (ZO-1) and DNA methyltransferase 1 (DNMT1), which is a direct target of miR-148a, in ileum in neonatal mice breastfed by stressed nursing mice were investigated using Western blot. Furthermore, to investigate the influence of miR-148a on ZO-1 expression within the intestine, the levels of ZO-1 and DNMT1 in human intestinal epithelial Caco-2 cells with lentivirus-mediated miR-148a overexpression were evaluated.

RESULTS

A significantly negative correlation was observed between relative miR-148a expression in breast milk and the total mood disturbance T-score. Each T-score on negative mood subscales of anger-hostility, confusion-bewilderment, depression-dejection, fatigue-inertia, and tension-anxiety was significantly negatively correlated with relative miR-148a expression in breast milk: a positive mood subscale vigor-activity T-score was significantly positively correlated with relative miR-148a expression in breast milk. A positive mood friendliness T-score, estimated separately from other scores, was significantly positively correlated with relative miR-148a expression in breast milk. Additionally, the relative expression of miR-148a in the milk obtained from stressed mice was significantly lower than that of control mice. The relative level of ZO-1 in ileum of neonatal mice nursed by stressed mice was significantly lower than that of neonatal mice nursed by control mice. Additionally, the relative level of DNMT1 in ileum of neonatal mice nursed by stressed mice was significantly higher than that of neonatal mice nursed by control mice. Furthermore, the relative level of ZO-1 in miR-148a-overexpressed Caco-2 cells was significantly higher than that in control cells. The relative level of DNMT1 in miR-148a-overexpressed Caco-2 cells was significantly lower than that in control cells.

CONCLUSIONS

Mothers' exposure to stress during lactation may cause miR-148a expression in breast milk. Additionally, stressed-induced suppression of miR-148a expression in breast milk may cause a decrease in intestinal ZO-1 level via the increase in DNMT1 in infants' intestines. These observations are beneficial information for breastfeeding mothers and their families and perinatal medical professionals. Our findings encourage monitoring maternal psychological stress during lactation to promote breastfeeding and adequate infant nutrition.

Comparative Study of the Expression Profiles of miRNAs of Milk-Derived Exosomes of Yak and Jeryak

The Jeryak is the hybrid offspring of yaks and Jersey cattle and exhibit improved milk and meat yields. Biomolecules carried within milk exosomes are important for cell growth, development, immune regulation, and various pathophysiological processes. Previous studies showed that miRNAs regulate mammary gland development, lactation, and milk quality. This study explored the relationship between milk exosomes miRNAs and lactation performance. A comparison of the milk content showed that yak milk was of a better quality compared to Jeryak milk (casein, fat, TS, SNF, lactose). Milk collected in December was superior to that collected in June for both yak and Jeryak, except for lactose concentrations. Exosomes were extracted by density gradient centrifugation and miRNA expression profiles in milk exosomes from three yaks and three Jeryaks collected in June and December were detected by small RNA sequencing. In all, 22, 120, 78, and 62 differentially expressed miRNAs (DEMs) were identified in Jun_ JY vs. Jun_ Y (P1: Jeryak in June vs. Yak in June), Jun_ JY vs. Dec_ JY (P2: Jeryak in June vs. Jeryak in December), Dec_ JY vs. Dec_ Y (P3: Jeryak in December vs. Yak in December), and Jun_ Y vs. Dec_ Y (P4: Yak in June vs. Yak in December) groups. These DEMs were enriched in functions and signaling pathways related to lactation performance. In conclusion, these findings are a reference tool to study the molecular basis of lactation performance.

The potential therapeutic role of Camel Milk Exosomes

Exosomes (EXOs) are naturally occurring tiny extracellular nanovesicles, which emancipate into the extracellular environment by exocytosis. By moving vital biological molecules (DNA, mRNA proteins, etc), EXOs contribute to intercellular communications. Camel milk (CM) as a valuable food, is rich of EXO. Nowadays, EXOs are promising delivery agents for several diseases therapy. Camel milk exosomes (CMEXOs) have unique ingredients in comparison to other animal milks. It is documented that CMEXOs reduce the growth of cancer cells through inducing apoptosis, inhibation of oxidative stress and inflammation occurance. By inhibation of inflammatory, and apoptosis pathways, CMEXOs could inhibit numerous of pathways, leading to adverse effects, due to drug levels over the therapeutic window. Moreover, CMEXOs exhibited a prominent property in improving the antioxidant capability in both in vitro and in vivo experiments. Moreover, the anti-angiogenesis property of CMEXOs was illustrated via decrease in expression of the angiogenesis-related gene; vascular endothelial growth factor (VEGF). It is expected that exosomal lactoferrin (LF) and kappa casein (KC) mRNAs are crucial parts of CMEXOs mediating their anticancer effects. The immunomodulatory effect of CMEXOs may be attributed to their high contents of LF and KC. According to previous works, CMEXOs are favorable elements in developing new therapeutic methods to remedy innumerable diseases. This review aims to provide an overview on the isolation, characterization and biological activities of the exosomes derived from camel milk for address their possible use in therapeutics.

Prediction of potential molecular markers of bovine mastitis by meta-analysis of differentially expressed genes using combined p value and robust rank aggregation

Bovine mastitis causes significant economic loss to the dairy industry by affecting milk quality and quantity. Escherichia coli and Staphylococcus aureus are the two common mastitis-causing bacteria among the consortia of mastitis pathogens, wherein E. coli is an opportunistic environmental pathogen, and S. aureus is a contagious pathogen. This study was designed to predict molecular markers of bovine mastitis by meta-analysis of differentially expressed genes (DEG) in E. coli- or S. aureus-infected mammary epithelial cells (MECs) using p value combination and robust rank aggregation (RRA) methods. High-throughput transcriptome of bovine MECs, infected with E. coli or S. aureus, were analyzed, and correlation of z-scores were computed for the expression datasets to identify the lineage profile and functional ontology of DEGs. Key pathways enriched in infected MECs were deciphered by Gene Set Enrichment Analysis (GSEA), following which combined p value and RRA were used to perform DEG meta-analysis to limit type I error in the analysis. The miRNA-gene networks were then built to uncover potential molecular markers of mastitis. Lineage profiling of MECs showed that the gene expression levels were associated with mammary tissue lineage. The up-regulated genes were enriched in immune-related pathways, whereas down-regulated genes influenced the cellular processes. GSEA analysis of DEGs deciphered the involvement of Toll-like receptor (TLR), and NF-kappa B signaling pathway during infection. Comparison after meta-analysis yielded with genes ZC3H12A, RND1, and MAP3K8 having significant expression levels in both E. coli and S. aureus dataset, and on evaluating miRNA-gene network, 7 pairs were common to both sets identifying them as potential molecular markers.

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.

Organelles coordinate milk production and secretion during lactation: Insights into mammary pathologies

The mammary gland undergoes a spectacular series of changes during its development and maintains a remarkable capacity to remodel and regenerate during progression through the lactation cycle. This flexibility of the mammary gland requires coordination of multiple processes including cell proliferation, differentiation, regeneration, stress response, immune activity, and metabolic changes under the control of diverse cellular and hormonal signaling pathways. The lactating mammary epithelium orchestrates synthesis and apical secretion of macromolecules including milk lipids, milk proteins, and lactose as well as other minor nutrients that constitute milk. Knowledge about the subcellular compartmentalization of these metabolic and signaling events, as they relate to milk production and secretion during lactation, is expanding. Here we review how major organelles (endoplasmic reticulum, Golgi apparatus, mitochondrion, lysosome, and exosome) within mammary epithelial cells collaborate to initiate, mediate, and maintain lactation, and how study of these organelles provides insight into options to maintain mammary/breast health.

Exosomal lnc-AFTR as a novel translation regulator of FAS ameliorates Staphylococcus aureus-induced mastitis

Although the specific expression of long noncoding RNA (lncRNA) in mastitis tissue has been reported, few studies have involved the differential expression of lncRNA in mastitis exosomes (Exo) and its mechanism and function. We screened an lncRNA associated with FAS translational regulation (lnc-AFTR) through exosomal RNA sequencing, and clarified its function and molecular mechanism. Lnc-AFTR is markedly downregulated in Staphylococcus aureus-Exo and S. aureus-induced MAC-T cell as well as mastitis tissue. Overexpression of lnc-AFTR exosomes (oe-AFTR-Exo) significantly improves cell damage induced by S. aureus, including inhibiting apoptosis, promoting proliferation, and increasing the production of pro-inflammatory cytokines (tumor necrosis factor-α [TNF-α] and interleukin-1β [IL-1β]). Oe-AFTR-Exo also suppressed the activation of Caspase-8, Caspase-3, and JNK. Dual-luciferase report analysis confirmed that lnc-AFTR interacts with FAS mRNA directly to hinder translation process, but does not degrade FAS mRNA. Overexpression of lnc-AFTR in MAC-T cells obviously reduced S. aureus-induced apoptosis and inflammation. Knockdown of lnc-AFTR significantly increased FAS and promoted the activation of Caspase-8, Caspase-3, and JNK caused by S. aureus. In summary, these results revealed the mechanism by which lnc-AFTR directly bound FAS mRNA to prevent translation, and confirmed that the exosomal lnc-AFTR exerted anti-inflammatory and anti-apoptotic effects by inhibiting the activation of TNF signaling pathway and mitogen-activated protein kinases (MAPK) signaling pathway.

circ01592 regulates unsaturated fatty acid metabolism through adsorbing miR-218 in bovine mammary epithelial cells

The composition of fatty acids plays a key role in regulating milk flavor and quality. Therefore, to improve the quality of milk, it is particularly important to study the regulatory mechanism of fatty acid metabolism in dairy cows. In this study, the expression profiles at non-lactation, peak-lactation, mid-lactation and late-lactation were constructed by high-throughput sequencing. Considering non-lactation as the control group and the other points as the experimental groups, the differentially expressed genes were screened. ELOVL5 was significantly upregulated and was selected for subsequent analyses. Bioinformatics prediction, a dual-luciferase assay, qPCR analysis and western blot analysis were used for verification. The results showed that ELOVL5 was a downstream target gene of miR-218 that regulated milk fat metabolism. A dual-luciferase assay and expression level analysis showed that circ01592 can directly bind to miR-218 and that overexpression of circ01592 (pcDNA-circ01592) significantly reduced the expression of miR-218 and enhanced the expression of ELOVL5, the target gene of miR-218 in BMECs. A functional study of BMECs showed that circ01592 promoted the synthesis of TAG and increased the content of UFA. The function of miR-218 was opposite to that of circ01592. Overall, the data showed that circ01592 promoted TAG synthesis and fatty acid composition by binding miR-218, alleviating the inhibitory effect of miR-218 on ELOVL5 expression. These mechanisms provide a new research approach and theoretical basis for improving milk quality.

Exosomes in Dogs and Cats: An Innovative Approach to Neoplastic and Non-Neoplastic Diseases

Exosomes are extracellular vesicles with a diameter between 40 and 120 nm, which are derived from all types of cells and released into all biological fluids, such as blood plasma, serum, urine, breast milk, colostrum, and more. They contain proteins, nucleic acids (mRNA, miRNA, other non-coding RNA, and DNA), and lipids. Exosomes represent a potentially accurate footprint of the miRNA profile of the parental cell and can therefore be proposed as potential and sensitive biomarkers, both in diagnosing and monitoring a variety of diseases in humans and animals. Liquid biopsy offers itself as a non-invasive or minimally invasive, pain-free, time-saving alternative to conventional tissue biopsy. Exosomes in both human and veterinary medicine find their major application in neoplastic diseases, but applications in the field of veterinary cardiology, nephrology, reproduction, parasitology, and regenerative medicine are currently being explored. Exosomes can therefore be used as diagnostic, prognostic, and, in some cases, therapeutic tools for several conditions. The aim of this review was to assess the current applications of exosomes in veterinary medicine, particularly in dog and cat patients.

Milk exosomes: Nature's abundant nanoplatform for theranostic applications

Exosomes are a unique subpopulation of naturally occurring extracellular vesicles which are smaller intracellular membrane nanoparticle vesicles. Exosomes have proven to be excellent nanocarriers for carrying lipids, proteins, mRNAs, non-coding RNAs, and DNAs, and disseminating long-distance intercellular communications in various biological processes. Among various cell-line or biological fluid derived exosomes, milk exosomes are abundant in nature and exhibit many nanocarrier characteristics favorable for theranostic applications. To be an effective delivery carrier for their clinical translation, exosomes must inbuilt loading, release, targeting, and imaging/tracking characteristics. Considering the unmet gaps of milk exosomes in theranostic technology it is essential to focus the current review on drug delivery and imaging applications. This review delineates the efficiency of exosomes to load therapeutic or imaging agents and their successful delivery approaches. It is emphasized on possible modifications of exosomes towards increasing the stability and delivery of agents. This article also summarizes the specific applications and the process of developing milk exosomes as a future pharmaceutical drug delivery vehicle.

Ruminant Milk-Derived Extracellular Vesicles: A Nutritional and Therapeutic Opportunity?

Milk has been shown to contain a specific fraction of extracellular particles that are reported to resist digestion and are purposefully packaged with lipids, proteins, and nucleic acids to exert specific biological effects. These findings suggest that these particles may have a role in the quality of infant nutrition, particularly in the early phase of life when many of the foundations of an infant's potential for health and overall wellness are established. However, much of the current research focuses on human or cow milk only, and there is a knowledge gap in how milk from other species, which may be more commonly consumed in different regions, could also have these reported biological effects. Our review provides a summary of the studies into the extracellular particle fraction of milk from a wider range of ruminants and pseudo-ruminants, focusing on how this fraction is isolated and characterised, the stability and uptake of the fraction, and the reported biological effects of these fractions in a range of model systems. As the individual composition of milk from different species is known to differ, we propose that the extracellular particle fraction of milk from non-traditional and minority species may also have important and distinct biological properties that warrant further study.

Personalized Nutrition Approach in Pregnancy and Early Life to Tackle Childhood and Adult Non-Communicable Diseases

The development of childhood and adult non-communicable diseases (NCD) is associated with environmental factors, starting from intrauterine life. A new theory finds the roots of epigenetic programming in parental gametogenesis, continuing during embryo development, fetal life, and finally in post-natal life. Maternal health status and poor nutrition are widely recognized as implications in the onset of childhood and adult diseases. Early nutrition, particularly breastfeeding, also plays a primary role in affecting the health status of an individual later in life. A poor maternal diet during pregnancy and lack of breastfeeding can cause a nutrient deficiency that affects the gut microbiota, and acts as a cofactor for many pathways, impacting the epigenetic controls and transcription of genes involved in the metabolism, angiogenesis, and other pathways, leading to NCDs in adult life. Both maternal and fetal genetic backgrounds also affect nutrient adsorption and functioning at the cellular level. This review discusses the most recent evidence on maternal nutrition and breastfeeding in the development of NCD, the potentiality of the omics technologies in uncovering the molecular mechanisms underlying it, with the future prospective of applying a personalized nutrition approach to prevent and treat NCD from the beginning of fetal life.

Extracellular vesicles piwi-interacting RNAs from skin mucus for identification of infected Cynoglossus semilaevis with Vibrio harveyi

Extracellular vesicles play a regulatory role in intracellular and intercellular transmission through a variety of biological information molecules, including mRNA, small RNAs and proteins. piRNAs are one kind of regulatory small RNAs in the vesicles at the post transcriptional level. Hereby, we isolated the extracellular vesicles from skin mucus and screened the piRNA profiles of these vesicles, aiming at developing biomarkers related to bacterial infections in Cynoglossus semilaevis. The different profilings of piRNAs in mucous extracellular vesicles of C. semilaevis were compared through small RNA sequencing, between fish infected with Vibrio harveyi and healthy ones. The number of clean reads on the alignment of exosome sick (ES) group was 105, 345 and that of exosome control (EC) group was 455, 144. GO and KEGG pathway enrichment analysis showed that most of the target genes were involved in cellular process, response to stimulus, biological regulation, immune system process and signal transduction, signal molecular and interaction, transport and catabolism. The 45 final candidate piRNAs related to immunity or infectious diseases included 20 piRNAs with high expression in the ES group and 25 piRNAs with a low expression in the ES group. After verification by qRT-PCR, there was significant difference of five piRNAs expression level between infected fish and healthy fish, in line with the sequencing. The expression level of piR-mmu-16401212, piR-mmu-26829319 and piR-gga-244092 in infected fish were significantly lower than that of control group, while piR-gga-71717 and piR-gga-99034 were higher, which implying that these piRNAs in mucous extracellular vesicles can be used to identify diseased fish from normal ones. This work supplied a novel class of biomarker for infection diagnosis in fish, and it will be benefit for screening disease resistant breeding of C. semilaevis.

Circulating microRNAs in Breast Milk and Their Potential Impact on the Infant

MicroRNAs (MiRNAs) are small RNA molecules that can exert regulatory functions in gene expression. MiRNAs have been identified in diverse tissues and biological fluids, both in the context of health and disease. Breastfeeding has been widely recognized for its superior nutritional benefits; however, a number of bioactive compounds have been found to transcend these well-documented nutritional contributions. Breast milk was identified as a rich source of miRNAs. There has been increasing interest about their potential ability to transfer to the offspring as well as what their specific involvement is within the benefits of breast milk in the infant. In comparison to breast milk, formula milk lacks many of the benefits of breastfeeding, which is thought to be a result of the absence of some of these bioactive compounds. In recent years, the miRNA profile of breast milk has been widely studied, along with the possible transfer mechanisms throughout the infant's digestive tract and the role of miRNA-modulated genes and their potential protective and regulatory functions. Nonetheless, to date, the current evidence is not consistent, as many methodological limitations have been identified; hence, discrepancies exits about the biological functions of miRNAs. Further research is needed to provide thorough knowledge in this field.

Milk Exosomes: Perspective Agents for Anticancer Drug Delivery

Exosomes are biological nanovesicles that participate in intercellular communication by transferring biologically active chemical compounds (proteins, microRNA, mRNA, DNA, and others). Due to their small size (diameter 40-100 nm) and high biological compatibility, exosomes are promising delivery tools in personalized therapy. Because artificial exosome synthesis methods are not developed yet, the urgent task is to develop an effective and safe way to obtain exosomes from natural sources. Milk is the only exosome-containing biological fluid that is commercially available. In this regard, milk exosomes are unique and promising candidates for new therapeutic approaches to treating various diseases, including cancer. The appearance of side effects during the use of cytotoxic and cytostatic agents is among the main problems in cancer chemotherapy. According to this, the targeted delivery of chemotherapeutic agents can be a potential solution to the toxic effect of chemotherapy. The ability of milk exosomes to carry out biologically active substances to the cell makes them promising tools for oral delivery of chemotherapeutic agents. This review is devoted to the methods of milk exosome isolation, their biological components, and prospects for their use in cancer treatment.