Sarah Adjei-Fremah

Effect of probiotic supplementation on growth and global gene expression in dairy cows

ABSTRACT Use of probiotic supplements as a non-chemical approach to promote health has increased in animal production. The present study evaluated the effect of oral probiotic administration on growth and global gene expression profile in dairy cows. Lactating Holstein-Friesian cows received a daily dose (50 ml) of a commercial probiotic (containing Lactobacillus acidophilus, Saccharomyces cerevisiae, Enterococcus faecium, Aspergillus oryza and Bacillus subtilis) for 60 days. A microarray experiment was performed with blood collected at day-0 and day-60. Although probiotic supplementation had no effect on body weight, PCV and total protein concentration in plasma (P > 0.05), per cent lymphocyte count increased (P < 0.05), and per cent neutrophil count decreased (P < 0.05) in probiotic-treated animals. Gene expression analysis identified 10,859 differentially expressed genes, 1168 up-regulated and 9691 down-regulated genes, respectively, following probiotic treatment. Single experiment pathway analysis identified 87 bovine pathways impacted by probiotic treatment. These pathways included the Toll-like receptor (TLR), inflammation response and Wingless signalling pathways. Oral administration of probiotics to dairy cows had a systemic effect on global gene expression, such as on genes involved in immunity and homeostasis. The results of this study show that the utilization of probiotics in animal agriculture impacts genes important to dairy cow health and production.

Transcriptional profiling of the effect of lipopolysaccharide (LPS) pretreatment in blood from probiotics-treated dairy cows

Probiotic supplements are beneficial for animal health and rumen function; and lipopolysaccharides (LPS) from gram negative bacteria have been associated with inflammatory diseases. In this study the transcriptional profile in whole blood collected from probiotics-treated cows was investigated in response to stimulation with lipopolysaccharides (LPS) in vitro. Microarray experiment was performed between LPS-treated and control samples using the Agilent one-color bovine v2 bovine (v2) 4x44K array slides. Global gene expression analysis identified 13,658 differentially expressed genes (fold change cutoff ≥ 2, P < 0.05), 3816 upregulated genes and 9842 downregulated genes in blood in response to LPS. Treatment with LPS resulted in increased expression of TLR4 (Fold change (FC) = 3.16) and transcription factor NFkB (FC = 5.4) and decreased the expression of genes including TLR1 (FC = − 2.54), TLR3 (FC = − 2.43), TLR10 (FC = − 3.88), NOD2 (FC = − 2.4), NOD1 (FC = − 2.45) and pro-inflammatory cytokine IL1B (− 3.27). The regulation of the genes involved in inflammation signaling pathway suggests that probiotics may stimulate the innate immune response of animal against parasitic and bacterial infections. We have provided a detailed description of the experimental design, microarray experiment and normalization and analysis of data which have been deposited into NCBI Gene Expression Omnibus (GEO): GSE75240.

Microarray analysis of the effect of Cowpea (Vigna unguiculata) phenolic extract in bovine peripheral blood

ABSTRACT In this study, the effect of polyphenolic extracts from cowpea (Vigna unguiculata) on global gene expression in bovine peripheral blood was investigated. Blood collected from Holstein-Friesian cows (n = 10) was treated with 10 µg/mL of cowpea phenolic extract (CPE) and subsequently used for transcriptional profiling using the Agilent bovine (v2) 4 × 44 K array. Calculation of fold change in gene expression and pathway analysis was conducted using the GeneSpring GX software 13.0. Real-time quantitative PCR was performed to validate the microarray data. Phenolic extracts of cowpea impacted global gene expression and resulted in 3170 differentially expressed genes (p < .05); 1716 genes were upregulated and 1454 genes were downregulated. Exposure to CPE impacted 66 pathways (p < .05) including the Wnt signalling pathway, Toll-like receptor pathway, inflammation response pathway, MAPK cascade pathway, prostaglandin synthesis and regulation pathway, cell cycle pathway, insulin signalling pathway, and the adipogenesis pathway. Expression of immune markers such as CD40, CD68, Toll-like receptors, and Wnt signalling changed. Exposure to CPE modulated expression of genes associated with immunity and homeostasis. Transcriptional profiles of the response to polyphenols may aid in the design of targeted diets to influence animal production and health and thus requires further study.