Methyl donor supply to heat stress-challenged polymorphonuclear leukocytes from lactating Holstein cows enhances 1-carbon metabolism, immune response, and cytoprotective gene network abundance

Abstract

Mechanisms controlling immune function of dairy cows are dysregulated during heat stress (HS). Methyl donor supply-methionine (Met) and choline (Chol)-positively modulates innate immune function, particularly antioxidant systems of polymorphonuclear leukocytes (PMN). The objective of this study was to investigate the effect of Met and Chol supply in vitro on mRNA abundance of genes related to 1-carbon metabolism, inflammation, and immune function in short-term cultures of PMN isolated from mid-lactating Holstein cows in response to heat challenge. Blood PMN were isolated from 5 Holstein cows (153 ± 5 d postpartum, 34.63 ± 2.73 kg/d of milk production; mean ± SD). The PMN were incubated for 2 h at thermal-neutral (37°C; TN) or heat stress (42°C; HS) temperatures with 3 levels of Chol (0, 400, or 800 μg/mL) or 3 ratios of Lys: Met (Met; 3.6:1, 2.9:1, or 2.4:1). Supernatant concentrations of IL-1β, IL-6, and tumor necrosis factor-α were measured via bovinespecific ELISA. Fold-changes in mRNA abundance were calculated separately for Chol and Met treatments to obtain the fold-change response at 42°C (HS) relative to 37°C (TN). Data were subjected to ANOVA using PROC MIXED in SAS (SAS Institute Inc., Cary, NC). Orthogonal contrasts were used to determine the linear or quadratic effect of Met and Chol for mRNA fold-change and supernatant cytokine concentrations. Compared with PMN receiving 0 μg of Chol/mL, heatstressed PMN supplemented with Chol at 400 or 800 μg/mL had greater fold-change in abundance of CBS, CSAD, GSS, GSR, and GPX1. Among genes associated with inflammation and immune function, fold-change in abundance of TLR2, TLR4, IRAK1, IL1B, and IL10 increased with 400 and 800 μg of Chol/mL compared with PMN receiving 0 μg of Chol/mL. Fold-change in abundance of SAHH decreased linearly at increasing levels of Met supply. A linear effect was detected for MPO, NFKB1, and SOD1 due to greater fold-change in abundance when Met was increased to reach Lys: Met ratios of 2.9:1 and 2.4:1. Although increasing Chol supply upregulated BAX, BCL2, and HSP70, increased Met supply only upregulated BAX. Under HS conditions, enhancing PMN supply of Chol to 400 μg/mL effectively increased fold-change in abundance of genes involved in antioxidant production (conferring cellular processes protection from free radicals and reactive oxygen species), inflammatory signaling, and innate immunity. Although similar outcomes were obtained with Met supply at Lys: Met ratios of 2.9:1 and 2.4:1, the response was less pronounced. Both Chol and Met supply enhanced the cytoprotective characteristics of PMN through upregulation of heat shock proteins. Overall, the modulatory effects detected in the present experiment highlight an opportunity to use Met and particularly Chol supplementation during thermal stress.

Multifaceted role of one-carbon metabolism on immunometabolic control and growth during pregnancy, lactation and the neonatal period in dairy cattle

“…They reported a decrease in mRNA abundance of Sadenosylhomocysteine hydrolase and linear increases in myeloperoxidase, NFKB1, and SOD1 with increasing Met supply. In addition, increasing supply of Met during heat stress also upregulated mRNA abundance of cysteine dioxygenase 1 and BCL2 associated X apoptosis regulator and heat shock protein 70 suggesting an improvement in antioxidant and cytoprotective characteristics [93]. Hence, transcriptional changes in bovine immune cells may at least partly explain the reduced inflammation status and improved immune function in peripartal cows fed RPM.…”

“…Cells incubated without choline had greater mRNA abundance of interleukins and genes involved in GSH metabolism; this effect, however, was ameliorated by supplementing additional Met [19]. More recently, Lopreiato et al [93] used isolated PMNL for incubations with 3 ratios of Lys:Met (3.6:1, 2.9:1 or 2.4:1) under thermoneutral or heat stress conditions. They reported a decrease in mRNA abundance of Sadenosylhomocysteine hydrolase and linear increases in myeloperoxidase, NFKB1, and SOD1 with increasing Met supply.…”

“…Choline may play an important role in modulating immune function during periods of heat stress. Lopreiato et al [93] isolated PMNL from cows (153 DIM) and incubated them with 0, 400 or 800 μg/mL of choline under thermoneutral or heat stress conditions. They observed that mRNA abundance of CBS, GSS, GSR, GPX1, TLR2, TLR4, IL1B, IL10, heat shock protein 70, BCL2 associated X increased with choline supply.…”

Empirical Evaluation and Prediction of Protein Requirements for Maintenance and Growth of 18–24 Months Old Thai Swamp Buffaloes

“…These achievements, in turn, lead to lowering the feed efficiency and ADG pattern. If the reduction in a feed intake represents a shift of caloric restriction allowing hyperthermic animals to reduce heat generation [ 38 ], a reduction in feed efficiency or ADG pattern was obtained from the limitation of nutrient digestion and metabolism in the rumen host permitting an alleviation of the protein synthesis rate, as indicated from the insufficient energy intake [ 12 ].…”

Effects of Biopolymers from Cassava Implanted with Rodent Bait on Wistar Rats

“…In this study, the neutrophil level was increased in all treatment groups except in the bait meal with 3.0 g of zinc phosphide when compared with the control. The gradual increase in neutrophil counts across the intervals in all treated groups reflects a stressful condition on the immune system [46][47]. These changes are significant, implying that all the treatments elicit a negative effect on neutrophil level.…”