Project description:Liver plays a profound role in the acute phase response (APR) observed in the early phase of acute bovine mastitis caused by Escherichia coli (E. coli). To gain an insight into the genes and pathways involved in hepatic APR of dairy cows we performed a global gene expression analysis of liver tissue sampled at different time points before and after intra-mammary (IM) exposure to E. coli lipopolysaccharide (LPS) treatment. Experiment Overall Design: Eight healthy, high yielding Holstein-Friesian dairy cows in their first lactation (9 to 12 weeks after calving) were chosen for this study. At time 0 the right front quarter was infused with 200 μg E. coli LPS dissolved in 10 ml 0.9% NaCl solution, the left front quarter serving as control was infused with 10 ml 0.9% NaCl solution. Liver biopsies were taken at â22, 3, 6, 9, 12 and 48 hours relative to LPS infusion in 4 cows, and also at â22, 9 and 48 hours in the remaining 4 cows. RNA from liver biopsies was isolated and biotin labeled cRNA was loaded onto the Affymetric GeneChip Bovine Genome Array. A control study using cows infused with 0.9% NaCl showed that there was no effect of taking the biopsy, neither in the clinical measurement nor in the expression of a selected subset of genes. Therefore, only samples taken from the LPS treated cows were measured for the gene expression using microarrays.
Project description:The liver of dairy cows naturally displays a series of metabolic adaptation during the periparturient period in response to the increasing nutrient requirement of lactation. The hepatic adaptation is partly regulated by insulin resistance and it is affected by the prepartal energy intake level of cows. We aimed to investigate the metabolic changes in the liver of dairy cows during the periparturient at gene expression level and to study the effect of prepartal energy level on the metabolic adaptation at gene expression level.B13:N13
Project description:Liver plays a profound role in the acute phase response (APR) observed in the early phase of acute bovine mastitis caused by Escherichia coli (E. coli). To gain an insight into the genes and pathways involved in hepatic APR of dairy cows we performed a global gene expression analysis of liver tissue sampled at different time points before and after intra-mammary (IM) exposure to E. coli lipopolysaccharide (LPS) treatment. Keywords: Time course
Project description:The study investigated the acute and simultaneous response of the mammary and liver transcriptome to an intra-mammary lipopolysaccharide (LPS) challenge in early-lactating cows, and its consequences on metabolic biomarkers and liver composition. At 7 days of lactation, 7 cows served as controls (CTR) and 7 cows (LPS) received an intra-mammary E. coli LPS challenge. The mammary and liver tissues were sampled at 2.5 h from challenge for transcriptomic profiling. Liver composition was evaluated at 2.5 h and 7 d after challenge and blood biomarkers were analized at -2, 3, 7 and 14 d from challenge. In mammary tissue, the LPS challenge resulted in 189 differentially expressed gene (DEG), with 20 downregulated and 169 upregulated, while in the liver were found 107 DEG with 42 downregulated and 65 upregulated in LPS vs CTR. In the udder, the Dynamic Impact Approach (DIA) highlighted the activation of NOD-like receptor signaling, Toll-like receptor signaling, RIG-I-like receptor signaling and Apoptosis pathways, while in the liver were inhibited the Fatty acid elongation in mitochondria and activated the p53 signaling pathway. The LPS induced the alteration of liver lipid metabolism (rise of total lipid and triglyceride concentration), a systemic inflammation (rise of blood ceruloplasmin and bilirubin) and an increase of body fat mobilization. In cows subjected to intra-mammary LPS, the mammary gland responds activating mechanisms of pathogen recognition. In the liver the response likely depends by mediators coming from udder and affects the liver functionality and mainly the fatty acid metabolism.
Project description:The study investigated the acute and simultaneous response of the mammary and liver transcriptome to an intra-mammary lipopolysaccharide (LPS) challenge in early-lactating cows, and its consequences on metabolic biomarkers and liver composition. At 7 days of lactation, 7 cows served as controls (CTR) and 7 cows (LPS) received an intra-mammary E. coli LPS challenge. The mammary and liver tissues were sampled at 2.5 h from challenge for transcriptomic profiling. Liver composition was evaluated at 2.5 h and 7 d after challenge and blood biomarkers were analized at -2, 3, 7 and 14 d from challenge. In mammary tissue, the LPS challenge resulted in 189 differentially expressed gene (DEG), with 20 downregulated and 169 upregulated, while in the liver were found 107 DEG with 42 downregulated and 65 upregulated in LPS vs CTR. In the udder, the Dynamic Impact Approach (DIA) highlighted the activation of NOD-like receptor signaling, Toll-like receptor signaling, RIG-I-like receptor signaling and Apoptosis pathways, while in the liver were inhibited the Fatty acid elongation in mitochondria and activated the p53 signaling pathway. The LPS induced the alteration of liver lipid metabolism (rise of total lipid and triglyceride concentration), a systemic inflammation (rise of blood ceruloplasmin and bilirubin) and an increase of body fat mobilization. In cows subjected to intra-mammary LPS, the mammary gland responds activating mechanisms of pathogen recognition. In the liver the response likely depends by mediators coming from udder and affects the liver functionality and mainly the fatty acid metabolism. Fourteen Holstein cows entering their second or greater lactation were used. Cows were housed in a ventilated tie-stall barn and were fed a common lactation diet (Net energy of lactation = 1.69 Mcal/kg DM) as a total mixed ration once daily (0600 h) and milked twice daily (0400 and 1600 h). A bovine oligonucleotide (70-mers) microarray with >13,000 annotated sequences developed at the University of Illinois, was used for transcript profiling. Details on the development, annotation, and use of this microarray have been reported previously by Loor et al., 2007 (http://physiolgenomics.physiology.org/content/32/1/105.abstract). Methods for microarray hybridization and scanning were as reported by Loor et al. (2007). Briefly, slides were hydrated, dried, and placed in a UV Stratalinker 1800 (Stratagene, La Joya, CA) for ~5 min. Slides were washed with 0.2% SDS solution, rinsed with MilliQ (Millipore) H2O, and placed in warm prehybridization soln for 45 min at 42 C. The same amount of Cy3- or Cy5-labelled cDNA from mammary or liver and a reference standard RNA pool (made of different bovine tissues) were co-hybridized using a dye-swap design (i.e., two microarrays per sample). Slides were incubated for 48 h at 45 C prior to scanning. Criteria for evaluation of slide quality included: identification of number of spots with a minimum median signal intensity of 3 SD above background; keeping slides with a minimum of 20,000 spots with minimum median signal intensity of 3 SD above background in both Cy3 and Cy5 channels; and keeping slides with a minimum mean intensity of 400 relative fluorescent units in both Cy3 and Cy5 channels across the entire slide. Data from a total of 112 microarrays were normalized for dye and microarray effects (i.e., Lowess normalization and microarray centering) and used for statistical analysis. Data were analyzed using the Proc MIXED procedure of SAS (SAS, SAS Inst. Inc., Cary, NC). Fixed effects were treatment (LPS challenge, control (no infsuion)) and dye. Random effects included cow and microarray. Raw P values were adjusted using Benjamini and HochbergM-bM-^@M-^Ys false discovery rate (FDR). Differences in relative expression due to treatment were considered significant at an FDR-adjusted P < 0.05. For a more stringent characterization between the two treatments, a 1.5-fold difference in mRNA expression was set as threshold among differentially expressed genes.
Project description:Microarray analysis of liver and mammary gland biopsies of dairy cows supplemented with vitamins B9 and B12 alone or in combination
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).