Project description:The potential of orally administered colostrum-derived EVs to regulate gut microbiota dysbiosis and prevent non-alcoholic steatohepatitis was evaluated. The results demonstrated that colostrum-derived EVs improved steatosis, fibrosis, and inflammation. Transcriptome analysis showed decreased lipid metabolism, bacterial response, and inflammatory responses in the intestine, and reduced inflammatory and fibrosis-related pathways in the liver. Gut microbiota and metabolite analysis revealed an increased abundance of Akkermansia and elevated cholesterol excretion. Additionally, treatment with colostrum-derived EVs increased the production of tight junction proteins and mucin in the intestine. These findings suggest that increased Akkermansia due to colostrum-derived EVs improves intestinal inflammation and barrier function, preventing endotoxin translocation to the liver and thereby reducing liver inflammation and fibrosis.
Project description:The protein profile of bovine milk serum was characterised as milk transitions from colostrum to transition milk over the first 5 days of lactation. Samples were collected from first and third parity cows at days 0, 2, 5 (D0, D2, D5) after calving. Following isolation of the milk serum fraction, label-free quantitative proteomics was carried out following normalisation by total protein concentration. Protein profiles indicated samples clustered by day postpartum, but not by parity. Proteins (n = 471) were identified and relative quantification was performed, with 199 protein groups showing altered abundance by day of lactation (fold change ≥ 2, P < 0.05). Elevated levels of immune proteins, including immunoglobulins and complement proteins were detected in colostrum with levels significantly decreasing by D2. These findings provide an outline of the dynamics of the protein profile of bovine milk and colostrum in early lactation.
Project description:α-Lactalbumin is an abundant protein present in the milk of most mammals, and is associated with biological, nutritional and technological functionality. Its sequence presents N-glycosylation motifs, the occupancy of which is species-specific, ranging from no to full occupancy. Here, we investigated the N-glycosylation of bovine α-lactalbumin in colostrum and milk sampled from four individual cows, each at 9 time points starting from the day of calving up to one month post-partum. Using a glycopeptide-centric mass spectrometry-based glycoproteomics approach, we identified N-glycosylation at both Asn residues found in the canonical Asn-Xxx-Ser/Thr motif, i.e., Asn45 and Asn74 of the secreted protein. We found similar glycan profiles in all four cows, with partial site occupancies averaging at 35% and 4% for Asn45 and Asn74, respectively. No substantial changes in occupancy occurred over lactation at either site. Fucosylation, sialylation primarily with N-acetylneuraminic acid (NeuAc) and a high ratio of N,N'-diacetyllactosamine (LacdiNAc)/N-acetyllactosamine (LacNAc) antennae were characteristic biochemical features of the identified N-glycans. While no substantial changes occurred in site occupancy at either site during lactation, the glycoproteoform profile revealed lactational dynamics; the maturation of the α-lactalbumin glycoproteoform repertoire from colostrum to mature milk was marked by substantial increases in neutral glycans and the number of LacNAc antennae per glycan, at the expense of LacdiNAc antennae. While the implications of α-lactalbumin N-glycosylation on functionality are still unclear, we speculate that N-glycosylation at Asn74 results in a structurally and functionally different protein, due to competition with the formation of its two intra-molecular disulphide bridges.
Project description:Liver and mammary gland are among the most prominent organs during lactation in dairy cows. With the purpose to understand 1) the adaptation of liver and mammary to different levels of forage/concentrate ration (60:40 vs. 40:60) and 2) the crosstalk between the two organs during lactation, a transcriptome analysis was performed on liver and mammary tissues of 10 primiparous dairy cows in mid-lactation. The analysis was performed using a 4x44K Bovine Agilent microarray chip. The mammary and liver samples were obtained from a subset of animals from a larger experiment where cows were fed two different levels of forage/concentrare ration (Archives of Animal Nutrition, 68:1, 63-71).