Project description:Oral administration of bovine milk-derived extracellular vesicles induces senescence in the primary tumor but accelerates cancer metastasis
Project description:Mycobacterium avium subspecies paratuberculosis (MAP) is the causative agent of Johne’s disease in cattle. MAP can be either shed directly into milk by infected cows, or introduced via fecal contamination. Viable MAP are detectable in milk and other dairy products, indicating survival of MAP after the pasteurization process. Although direct evidence is still lacking, MAP are discussed as a possible factor in the morbidity for chronic inflammatory bowel diseases in humans, such as Crohn’s disease and ulcerative colitis. Therefore, it is broadly accepted in the scientific community that exposure to MAP, especially through contaminated milk and dairy products, should be kept to a minimum. To gain deeper insight into the role of milk in MAP transmission and the question of why MAP can survive pasteurization, we investigated MAP proteome changes after incubation in milk at 37°C (simulating the environment in the mammary gland) and 4°C (simulating tank milk) as well as incubation in liquid control medium at 37°C.
Project description:Milk-derived extracellular vesicles (mEVs) have been proved to play a critical role in intercellular communication, mainly through the microRNAs (miRNAs) that they carry, to regulate biological functions of the target cells. Given miRNAs are evolutionarily conserved, EVs present in commercial milk may play a role in the physiology and health consumers. It is therefore essential to know the effects of technological treatments such as skimming and spray drying on the EV content of milk powders and on the cargo of bioactive molecules, in particular miRNAs, that they convey. Since goat’s milk or goat milk based formulas are considered as a healthy alternative for infants with cow’s milk sensitivities, including allergy, we undertook to analyze the EV content of skimmed and unskimmed goat's milk powders and to characterize their RNA content, in particular their miRNomes. mEVs were isolated using an optimized protocol based on Size Exclusion Chromatography (SEC) and compared regarding morphology, number and size by Transmission Electron Microscopy (TEM) and Nanoparticle Tracking Analysis (NTA). Their RNA and protein content were determined and their miRNomes established, using RNA sequencing. In this study we demonstrated that goat milk powders, skimmed or not upstream the spray drying treatment, contained many mEVs, ranging from 5.4 1011 to 2.5 1012 particles per mL of reconstituted milk, with an average size between 136.8 and 160.6 nm. We also demonstrated that mEVs carried significant amounts of RNA, including miRNAs. Using RT-qPCR, mRNAs encoding five of the major milk proteins were detected, suggesting that mEVs originated from mammary epithelial cells. We established the goat milk powder miRNome by identifying 351 miRNAs of which 233 are common to the 262 miRNAs previously profiled in raw goat milk. The 20 most abundant miRNAs (TOP 20) account for 80% of the total reads and the hierarchy of this TOP 20 miRNAs is somewhat overturned when comparing goat milk powder and raw goat milk. Surprisingly, whereas the comparison of raw from cow and goat milk confirmed the prevalence of miR-148a, miR-21-5p and miR-26a/miR-30a-5p, let-7a-5p and let-7f, which occupied ranks 1 and 2, respectively, in powders, were relegated to ranks 6 and 10 and 5 and 11 in raw goat and cow milk, respectively. Conversely to what was previously reported, we provide evidence that: i) EVs of typical morphology are present in goat milk powders; ii) mEVs survived the technological processes used to produce the powders; iii) their miRNA cargo is protected from degradation even though their miRNomes are not an exact mirror of miRNomes of EVs derived from fluid raw milk.
Project description:Breast milk contains macromolecular components with distinctive functions, whereby milk fat globules and casein micelles provide nutrition, while whey contains molecules that stimulate the infant’s immunity. Interestingly, the importance and function of extracellular vesicles (EV) in milk has not been addressed in detail. This in part is due to the difficulty to purify EV from other milk components and consequently the molecular composition of human milk-derived EV has not been fully elucidated. Methods: In this study, an extensive LC-MS/MS proteomic analysis was performed on EV isolated via density-based separation from human breast milk of 7 individuals. The proteome of milk-derived EV was analyzed using FunRich and compared to the Vesiclepedia database, as well as to the whole milk proteome, which was constructed from 38 previously published milk proteomics studies.
Project description:Mammalian milk is not only a source of nutrition for the newborn, but also contains various components that regulate further development. For instance, milk is an abundant source of microRNAs (miRNAs), which are evolutionary conserved small non-coding RNAs that are involved in post-transcriptional regulation of target mRNA. MiRNAs present in milk can occur in extracellular vesicles (EV), which are nanosized membrane vesicles released by many cell types as a means of intercellular communication. The membrane of EV protects enclosed miRNAs from degradation and harbors molecules that allow specific targeting to recipient cells. Although several studies have investigated the miRNA content in milk EV from individual species, little is known about the evolutionary conserved nature of EV-associated miRNAs among different species. In this study, we profiled the miRNA content of purified EV from human and porcine milk. These data were compared to published studies on EV from human, cow, porcine and panda milk to assess the overlap in the top 20 most abundant miRNAs. Interestingly, several abundant miRNAs were shared between species (e.g. let-7 family members let-7a, let-7b, let-7f, and miR-148a). Moreover, these miRNAs have been implicated in immune-related functions and regulation of cell growth and signal transduction. The conservation of these miRNA among species, not only in their sequence homology , but also in their incorporation in milk EV of several species, suggests that they are evolutionarily selected to regulate cell function in the newborn.
Project description:Background: Human milk extracellular vesicles (EVs) affect various cell types in the gastrointestinal tract, including T cells, and play a role in the development of the newborn’s immune system by delivering specific molecular cargo to target cells. Although maternal allergic sensitization alters the composition of milk, it is unknown whether this impacts the function of milk EVs. Therefore, we analyzed the T cell modulatory capacity and compared the protein and miRNA cargo of EVs from milk of allergic and non-allergic mothers. Methods: EVs were isolated from human milk from allergic and non-allergic donors by differential centrifugation, density gradient floatation and size exclusion chromatography. Functional modulation of primary human CD4+ T cells by EVs was assessed in vitro. Proteomic analysis and small RNA sequencing was performed on milk EVs to evaluate protein and miRNA abundance and to identify cellular targets of this EV cargo in relevant T cell signaling pathways. Results: T cell proliferation, activation and cytokine production were suppressed in the presence of milk EVs. Remarkably, milk EVs from allergic mothers modulated T cell activation to a lesser extent than EVs from non-allergic mothers. Integrative multi-omics analysis identified EV cargo of which the cellular targets could be linked to T cell activation-associated processes. Conclusions: Milk EVs from non-allergic mothers are stronger inhibitors of T cell activation compared to milk EVs from allergic mothers. This altered functionality might be linked to small changes in modulation of certain T cell signaling pathways.
Project description:Extracellular vesicles (EVs) and their microRNA (miRNA) cargo have been suggested as potential biomarkers for mammary gland health in cattle. However, milk is a dynamic fluid, and its biologically active components, including miRNAs, could be subject to changes throughout the day. 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 manually from one quarter during four consecutive days in the two daily milking sessions in the morning and the afternoon. The SCC was determined, and the milk EVs were isolated from skimmed milk. The presence of EVs was confirmed by transmission electron microscopy (TEM), tunable resistive pulse sensing (TRPS), and western blot (WB). Small RNA libraries were produced from 10 ng of extracted RNA and sequenced in two lanes of a HiSeq2500. The heterogeneity and integrity of EVs and the protein EV markers CD9, CD81, and TSG101 were confirmed by TEM and WB. The sequencing revealed that despite daily fluctuation in other milk components, like the somatic cells during milking sessions, the miRNA cargo abundance in milk EVs stayed constant. Our results show that the miRNA cargo of milk EVs is very stable regardless of the hour of the day, supporting their potential use as diagnostic markers for mammary gland health.
Project description:It is unclear to what degree protein degradation occurs in the infant stomach and whether peptides previously annotated for bioactivity are released. This study combined nanospray liquid chromatography separation with time of flight mass spectrometry, comprehensive structural libraries and informatics to interrogate milk of three human mothers and the gastric aspirates from their 4–12 day post-partum infants. Milk from the mothers contained almost two hundred distinct peptides, demonstrating enzymatic degradation of milk proteins beginning either during lactation or between milk collection and feeding. In the gastric samples, 649 milk peptides were identified, demonstrating that digestion continues in the infant stomach. The majority of peptides in both the intact milk and gastric samples were derived from β-casein. The numbers of peptides from β-casein, lactoferrin, α-lactalbumin, lactadherin, κ-casein, serum albumin, bile-salt associated lipase and xanthine dehydrogenase/oxidase were significantly higher in the gastric samples than the milk samples (p<0.05). Six hundred three peptides were significantly different in abundance between milk and gastric samples (p<0.05). Most of the identified peptides have previously identified biological activity. Gastric proteolysis occurs in the term infant in the first two weeks of life releasing biologically active milk peptides with immunomodulatory, antibacterial, and calcium-binding activity of clinical relevance to the proximal intestinal tract.
Project description:Mare milk is rich in nutrients and bioactive compounds, suggesting that its exosomes may possess immunomodulatory properties. We used microarray technology to profile the global gene expression of mare milk-derived small extracellular vesicles (MM-sEVs) and identified distinct classes of differentially expressed miRNAs targeting pathways and associated with diseases.