Project description:Cows were fed a lactation diet at ad libitum intake (n = 6). At 27±3 days in milk, cows were injected with 50 µg of LPS E. coli in one healthy rear mammary quarter. Milk samples were collected just before LPS challenge (LPS-) and 6.5 h after LPS challenge (LPS+) from the same cows. Microarray analysis was performed using customized 8x60K ruminant miRNA microarrays to compare LPS- to LPS+ miRNome. MiRNome comparison between LPS- and LPS+ identified 37 differentially abundant miRNAs (q-value ≤ 0.05)
Project description:Supplementation of a Saccharomyces cerevisiae fermentation product modulates dairy cows health by reducing incidence and severity of mastitis, one of the most common and economically important diseases of the dairy industry. However, mechanisms remain unclear. We conducted a comprehensive molecular analysis, along with physiological data, on dairy cows supplemented for 45 days with NutriTek, a commercially available S. cerevisiae fermentation product, and then subjected to a mastitis challenge . NutriTek supplementation improved cow’s responses to a mastitis challenge by stimulating influx of immune cells to the mammary gland , enhancing their bactericidal capacity, and protecting mammary tissues from the side effect of an immune response allowing faster and more complete recovery from milk production drop
Project description:Mastitis is defined as inflammation of the mammary gland and one of the most serious concerns with regards to milk production and animal health in dairy industry. Indeed, mastitis have marked influence on the milk yield, milk constituents, milk quality and nourishment of the neonates. We performed a comparative proteome analysis of the bovine milk obtained from healthy, sub-clinical and clinical mastitis from Indian indigenous cattle Karan Fries.
Project description:In dairy ruminants transcriptome profiling has enabled the identification of genes, pathways and regulatory networks activated in mammary tissues during experimental infection by various pathogens, including E. coli, S. aureus and S. uberis. Information in goats are still low and many host-pathogen interaction mechanisms have to be explained. The objectives of the present study were (1) to identify the network of genes that becomes activated in caprine blood and milk somatic cells in early response towards a S. aureus challenge in order to better understand the local and sistemic response and (2) to search any difference in this immune response by using two animal groups belonging to a caprine reference family established based on founders with adverse SCC breeding values. Udders from ten healthy French Alpine goats were infected with S. aureus and samples of blood and milk cells were collected at 0, 24 and 30 hours after infection. Alterations in the transcriptome profile were investigated using a custom bovine DNA microarray containing 43.822 unique gene probes.
Project description:We performed a genome-wide transcriptional analysis in the mammary gland in a mouse model of E. coli mastitis using high-density mouse oligonucleotide microarrays. This global transcription analysis revealed that about 7% of tested genes are mobilized in the mouse mammary gland to E. coli endotoxin. We identified 1402 differentially expressed genes that were associated with physiological system development/function and molecular/cellular functions and metabolic/signalling pathways that are highly relevant to host immune-inflammatory defense response against E. coli infection. The mouse differentially expressed genes through the use of comparative mapping/genomics and positional information on reported QTL for bovine mastitis allowed identifying 293 potential candidate genes for bovine mastitis. This study will enable other researchers to combine our mRNA expression data with genetic association studies to discover genomic variation underlying variation of susceptibility to mastitis in dairy cows. Keywords: time course, disease state analysis
Project description:Mastitis is a common disease in dairy cows and brings massive losses to the dairy industry. m6A is a type of modification strongly associated with many diseases. However, the role of m6A in mastitis caused by Staphylococcus aureus and Escherichia coli has not been investigated.We used MeRIP-seq technology to sequence the bovine mammary epithelial cells (MAC-T) infected with inactivated S. aureus/E. coli for 24 h.
Project description:We performed a genome-wide transcriptional analysis in the mammary gland in a mouse model of E. coli mastitis using high-density mouse oligonucleotide microarrays. This global transcription analysis revealed that about 7% of tested genes are mobilized in the mouse mammary gland to E. coli endotoxin. We identified 1402 differentially expressed genes that were associated with physiological system development/function and molecular/cellular functions and metabolic/signalling pathways that are highly relevant to host immune-inflammatory defense response against E. coli infection. The mouse differentially expressed genes through the use of comparative mapping/genomics and positional information on reported QTL for bovine mastitis allowed identifying 293 potential candidate genes for bovine mastitis. This study will enable other researchers to combine our mRNA expression data with genetic association studies to discover genomic variation underlying variation of susceptibility to mastitis in dairy cows. Keywords: time course, disease state analysis This study was conducted using a split-plot design. We measured levels of gene expression in healthy (saline injected) and diseased (E. coli injected) mammary gland tissue (treatment = 2, in sub-plots). The mammary tissue samples were collected at two-time points: 24 hr and 48 hr post-injection (time = 2, in main-plots). Each inbred mouse was injected with both treatments: the 4th left mammary gland was injected with saline solution and the 4th right mammary gland was injected with E. coli solution (mice = 4). The expression profiling was carried out using two biological replications (replication = 2) at each time point.
Project description:Methods: During the last trimester of the gestation, three heifers were immunized using intramuscular injections of heat-killed E. coli P4 emulsified in Montanide ISA 61VG® adjuvant (SEPPIC). Two months later, they received a mammary ductal injection of 50 µg protein from concentrated E. coli supernate as a booster. Control cows were injected intramuscularly with adjuvant only at the same dates. Cows were then challenged on average at 140 days in milk in one healthy quarter by infusion of a E. coli P4 bacterial suspension (10e3 bacteria in total). Cows were then euthanized 16 hours after inoculation for mammary tissue collection. After collagenase and DNase treatment and Percoll-gradient separation, CD45+ CD4+ mononuclear cells were sorted by flow cytometry. RNA was extracted and sequenced using Illumina protocol. Results : Mammary Th17-polarized CD4 T cells predominate in the mammary tissue of cows immunized through the local route, and are activated after challenge with E. coli. Conclusions: Local immunization promotes the development of TH17 immunity that correlated with protection.
Project description:Purpose: The goal of this study is to explore the role of miRNAs in dairy cow response to E. coli and S. aureus, mastitis causing pathogens, is not well understood. Results: The global expression of miRNAs in bovine mammary epithelial cells (MAC-T cells) challenged with heat-inactivated Staphylococcus aureus (S. aureus) or Escherichia coli (E. coli) bacteria (treatments: 6, 12, 24 and 48 hr) and without challenge (control: 0, 6, 12, 24 and 48 hr) was profiled using next-generation-sequencing. A total of 231 known bovine miRNAs were identified with more than 10 counts per million (CPM) in at least one of 13 libraries and 5 miRNAs including bta-miR-21-5p, miR-27b, miR-22-3p, miR-184 and let-7f represented more than 50% of the total reads of known bovine miRNAs. One hundred and fifty novel miRNAs were identified and half of them belong to the bta-miR-2284 family. Seventeen miRNAs were significantly (P<0.05) differentially regulated by the presence of pathogens. E. coli initiated an earlier regulation of miRNAs (6 miRNAs differentially regulated within the first 6 hrs post challenge as compared to one for S. aureus) while S. aureus presented a delayed response. Five differentially expressed miRNAs (Bta-miR184, miR-24-3p, miR-148, miR-486 and bta-let-7a-5p) were unique to E. coli while four (bta-miR-2339, miR-499, miR-23a and miR-99b) were unique to S. aureus. In addition, our study revealed a temporal differential regulation of five miRNAs (bta-miR-193a-3p, miR-423-5p, miR-30b-5p, miR-29c and miR-un116) in unchallenged cells. Target gene predictions of pathogen differentially expressed miRNAs indicate a significant enrichment in gene ontology functional categories in development/cellular processes, biological regulation as well as cell growth and death. Furthermore, target genes were significantly enriched in several KEGG (Kyoto encyclopedia of genes and genomes) pathways of the immune system, signal transduction, cellular process, nervous system, development and pathways in human diseases, especially cancer. Conclusion: Using next-generation sequencing, our study identified 150 novel bovine miRNAs and revealed a pathogen directed differential regulation of miRNAs in MAC-T cells with roles in immunity and development. E. coli elicited an earlier differential regulation of miRNAs as opposed to a delayed regulation by S. aureus. Furthermore, target gene prediction showed significant enrichments for functions in different biological and cellular processes as well as KEGG pathways in immunity, development and human diseases. Our study provides a further confirmation of the involvement of mammary epithelia cells in contributing to the immune response to infecting pathogens and suggests the potential of miRNAs to serve as biomarkers for diagnosis of mastitis and development of control measures. Bovine mammary epithelial cells (MAC-T cells) challenged with heat-inactivated Staphylococcus aureus (S. aureus) or Escherichia coli (E. coli) bacteria (treatments: 6, 12, 24 and 48 hr) and without challenge (control: 0, 6, 12, 24 and 48 hr) was profiled using next-generation-sequencing, no replicates, using illumina HiScanSQ platform.
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.