The effects of elevated subcutaneous fat stores on fatty acid composition and gene expression of proinflammatory markers in periparturient dairy cows

Abstract

During the periparturient period, elevated circulating nonesterified fatty acids (NEFA) from excessive lipid mobilization affect not only the circulating fatty acid (FA) composition, but also that of the peripheral blood mononuclear cells (PBMC) and polymorphonuclear leukocytes (PMNL). However, the changes to specific lipid fractions remain unknown. We hypothesized that elevated lipid mobilization will alter FA profiles and gene expression of selected proinflammatory mediators in PBMC and PMNL. Starting -28 d relative to expected calving (d 0), treatment cows (n = 18) received a dry cow ration plus an additional 10 kg of corn/head per day, while the control cows (n = 16) received the dry cow ration (no additional corn) supplemented with 400 mg of monensin/head per day to minimize lipid mobilization. Postpartum, treatment cows were feed deprived for 8 h on d +3. For FA analysis, serum was collected on d -28 and -7 relative to expected parturition and d +1, +3, +6, +15, and +21 postpartum, in addition to milk samples. Immune cells, PBMC and PMNL, were isolated on d -28, +3, +12, and +21 for FA analysis and gene expression analysis by reverse-transcription PCR. Serum, PBMC, and PMNL lipids were fractionated into NEFA and phospholipids (PL). The FA composition of milk, serum, PBMC, and PMNL was analyzed by gas chromatography. Data were analyzed as repeated measures ANOVA using mixed model procedures in SAS (9.3) with significance declared at P ≤ 0.05. Several FA varied by treatment and across time and parity. Within the serum PL fraction, FA associated with altered immune function, C18:3n-6, C20:4, C20:5, total n-3, and the ratio of n-6 to n-3 varied significantly by a treatment × parity × time interaction. Overall, FA composition of NEFA and PL fractions from PBMC and PMNL did not significantly reflect FA of serum. Gene expression for IL-1β in PBMC was greater for control, whereas ICAM, IL-1β, IL-6, and TNF-α were greater in primiparous than multiparous cows, without a detectable treatment effect. Whereas gene expression of CASP, IL-8R, and SELL in PMNL changed over time, no treatment effect was detected. In summary, high-energy prepartal diets altered FA profile in serum, milk, PBMC, and PMNL lipids; however, gene expression of selected proinflammatory mediators was not significantly affected.

The Effects of Sodium Acetate on the Immune Functions of Peripheral Mononuclear Cells and Polymorphonuclear Granulocytes in Postpartum Dairy Cows

“…In order to compensate for the lack of energy, the body will mobilize lipids for decomposition; however, excessive lipid mobilization triggers a mass of free fatty acids to accumulate in the liver, resulting in fatty liver in postpartum dairy cows, with triglyceride accumulation impairing liver function and increasing pro-inflammatory responses [22]. In addition, excessive lipid mobilization also despoils the amount of inclusion of the leukocyte membrane, triggering the disruption of the membrane function of PBMC and PMN cells [23]. Additionally, impaired PBMC and PMN functions also increase susceptibility to disease in postpartum dairy cows [8].…”

Effect of Different Combinations of Dietary Vitamin A, Protein Levels, and Monensin on Inflammatory Markers and Metabolites, Retinol-Binding Protein, and Retinoid Status in Periparturient Dairy Cows

“…Peripheral blood mononuclear cells (PBMC) were isolated, according to Scholte et al, [ 24 ] with modifications, from 50 mL of blood by gradient centrifugation using a mixture of Histopaque 1077 and 1119 (Sigma Aldrich, St. Louis, MO, USA). After centrifugation at 456× g for 1 h at room temperature, plasma was discarded, and the buffy coat and red blood cells were collected.…”

Yeast Culture Supplementation Effects on Systemic and Polymorphonuclear Leukocytes’ mRNA Biomarkers of Inflammation and Liver Function in Peripartal Dairy Cows

“…Parity effects on gene expression regulation in PMNLs have seldom been reported in dairy cows. For instance, Scholte et al [56] observed an upregulation of genes related to inflammation (i.e., IL1B, IL6, and TNFA) and cell adhesion (ICAM) in primiparous cows in comparison to multiparous during the transition period. This suggests that younger animals have a more active immune response or better immunocompetence than older cows, where milk production might restrict nutrients to sustain a viable immune response.…”