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ARS Home » Northeast Area » Beltsville, Maryland (BARC) » Beltsville Agricultural Research Center » Animal Genomics and Improvement Laboratory » Research » Publications at this Location » Publication #330212

Title: Glucose supplementation has minimal effects on blood neutrophil functionand gene expression in vitro

Author
item GARCIA, M - University Of Maryland
item Elsasser, Theodore
item JUENGST, J - University Of Maryland
item QU, Y - University Of Maryland
item ZHU, X - University Of Maryland
item MOYES, K - University Of Maryland

Submitted to: Journal of Dairy Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/5/2015
Publication Date: 6/25/2015
Citation: Garcia, M., Elsasser, T.H., Juengst, J., Qu, Y., Zhu, X., Moyes, K.M. 2015. Glucose supplementation has minimal effects on blood neutrophil functionand gene expression in vitro. Journal of Dairy Science. 98(9):6139-6150.

Interpretive Summary: Dairy cows face challenging demands on their basic metabolism right after they deliver their calf and begin to product milk. It is hard for them to even eat enough to satisfy their needs to make milk and the question has arisen as to whether or not the amount of glucose (the major energy source for metabolism at this time) circulating in their blood might affect how efficiently immune cells that guard against infection work. Researchers at the University of Maryland and USDA-ARS, Beltsville, MD looked into this important question by collecting white blood cells, the immune cells used for disease protection, from cows right after they had given birth or a while after and cultured them in the presence of different levels of glucose. White blood cell functions looked at included how they move in response to an infection stimulus, how efficiently they take up invading bacteria and how much of an enzyme that destroys bacteria is produced. In addition researchers looked at how the gene expression of these immune cells changes with the different levels of glucose. The researchers observed that glucose supplementation into the culture media increased white blood cell uptake of bacteria but did not alter their tendency to move towards infection. Neither was gene expression changed by increasing glucose. What they did notice was that the overall efficiency of the white blood cells was greater in cells collected from cows that had given birth several weeks earlier in contrast the responses observed from cells in freshly calved cows. Collectively, the information suggests that increasing the nutrient content of diets in early lactation may be advantageous to white blood cell function in cows.

Technical Abstract: During early lactation, glucose availability is low and the effect of glucose supply on bovine polymorphonuclear leukocyte (PMNL) function is poorly understood. The objective of this study was to determine the effect of glucose supplementation on the function and transcriptomic inflammatory response of PMNL from cows in early and mid-lactation in vitro. Twenty Holstein cows in early (n=10; days in milk=17±3.1) and mid-lactation (n=10; days in milk=168±14.8) were used for this study. Jugular blood was analyzed for serum concentrations of nonesterified fatty acids, ß-hydroxybutyrate, and glucose. Polymorphonuclear leukocytes were isolated and diluted using RPMI (basal glucose concentration was 7.2 mM) to different concentrations of PMNL/mL for phagocytosis, chemotaxis, gene expression, and medium analyses. Working solutions of glucose (0 or 4 mM of d-glucose) and lipopolysaccharide (0 or 50µg/mL) were added and tubes were incubated for 120 min at 37°C. Media were analyzed for concentrations of glucose and tumor necrosis factor-a (TNF-a). Data were analyzed in a randomized block (stage of lactation) design. Challenge with lipopolysaccharide increased the expression of the genes encoding for nuclear factor kappa B (NFKB1), IL-10 (IL10), IL1B, IL6, IL8, TNF-a (TNFA), glucose transporter 3 (SLC2A3), and the concentration of TNF-a in medium (147.3 vs. 72.5 pg/mL for lipopolysaccharide and control, respectively). Main effect of stage of lactation was minimal where the expression of IL10 increased for cows in early compared with cows in mid-lactation. After lipopolysaccharide challenge, cows in early lactation experienced more marked increases in the expression of IL6, TNFA, and IL8 when compared with cows in mid-lactation. Glucose supplementation had minimal effects on gene expression where glucose supplementation increased the expression of lysozyme (LYZ). Glucose supplementation increased PMNL phagocytosis but did not alter chemotaxis, morphology, or concentration of TNF-a in the medium. Under the conditions of the experiment, stage of lactation had minimal effects on PMNL response to glucose supply where only the expression of NFKB1 and the production of TNF-a were greater for cows in mid-lactation when compared with early lactation. Metabolic profiles for cows in early lactation did not parallel those for cows during the early postpartum period and may partly explain results for this study. Future studies investigating the effect of glucose supply on bovine PMNL function in vivo and how this may be altered by stage of lactation are warranted.