Project description:Mastitis, the inflammation of the mammary gland, is one of the most prevalent diseases in dairy farming worldwide. Unfortunately, the disease is most often present in a subclinical type with no clear symptoms. The sooner the infection is detected, the less opportunities for the disease to progress and the more treatment options remain available. Milk microRNA (miRNA) encapsulated in extracellular vesicles (EV) have been proposed as potential biomarkers of different mammary gland conditions, including subclinical mastitis. However, little is known about the robustness of EV analysis regarding sampling time-point or natural infections. In order to estimate the reliability of EV measurements in raw bovine milk, we first evaluated the changes in EV size, concentration and miRNA cargo during three consecutive days. Then, we compared milk EV differences from natural infected quarters with high somatic cell count (SCC) with their healthy adjacent quarters with low SCC and quarters from uninfected udders. We found that milk EV miRNA cargo is very stable along three days and that infected quarters do not induce relevant changes in milk EV of adjacent healthy quarters, making them suitable controls. We observed cow-individual changes in immunoregulatory miRNA in quarters with chronic subclinical mastitis, pointing towards infection-specific alterations. Finally, we proposed bta-miR-223 as a potential indicator of subclinical mastitis prognosis in raw milk.
Project description:Analysis of gene expression changes in milk somatic cells (MSCs) that occur with Staph Aureus mastitis. We used in house microarrays to indicate the changes that occur in gene expression in the BMCs as a result of mastitis Keywords: single time point, comparison mastitis animal vs control animal
Project description:Milk microRNAs (miRNAs) encapsulated in extracellular vesicles (EVs) are a novel class of bioactive food compounds. Milk produced by cows with subclinical mastitis threatens animals healthy and milk safety. However, little is known about the differentially expressed miRNA in milk-derived EVs related to subclinical mastitis. This study profiled miRNAs in milk-derived EVs from healthy cows and cows with subclinical mastitis. The potential targets for differentially expressed (DE) miRNAs were predicted. Milk-derived EVs were isolated from healthy cows (n = 7, the control group) and cows with subclinical (n = 7, the SM group). Two hundred ninety miRNAs (221 known and 69 novel ones) were identified. The top 20 miRNAs were commonly abundant (> 0.1% of the total read counts) in Healthy and SM groups, were regarded as abundant bovine milk-derived EVs miRNAs. MiR-21-5p was the most highly expressed known miRNA. Target genes of the top 20 abundant miRNAs were significantly enriched in Ras signaling pathway. The bta-miR-21-5p, bta-miR-30a-5p and miR-6-1096 were differentially expressed. For DE miRNAs, there was no significantly enriched pathways were found in the KEGG enrichment analysis. The linkage between the validated target genes and diseases suggested that we pay particular attention to exosome miRNAs from mastitic milk in milk safety.