Analysis of the bovine neutrophil transcriptome during glucocorticoid treatment

Abstract

The objective of this study was to characterize a large portion of the bovine neutrophil transcriptome following treatment with the anti-inflammatory glucocorticoid dexamethasone (Dex). Total RNA was isolated from blood neutrophils of healthy cattle (5 castrated male Holsteins) immediately following cell purification (0 h) or after ex vivo aging for 4 h with or without added Dex. Additional neutrophils were cotreated with a glucocorticoid receptor (GR) antagonist (RU486) and Dex for 4 h. RNA was amplified, dye labeled (Cy3 or Cy5), and hybridized to a series of National Bovine Functional Genomics Consortium (NBFGC) microarrays. LOWESS data normalization followed by mixture model analyses showed that 11.15% of the spotted NBFGC cDNAs (2,036/18,263) were expressed in 4-h (untreated) neutrophils. Subsequent two-step mixed-model analysis detected (P < or = 0.05) 1,109 differentially expressed genes, of which contrast analysis indicated those that were independently responsive to aging (1,064), Dex (502), RU486 + Dex (141), or RU486 (357). In silico analysis revealed that 416 of the differentially expressed genes are unknown, 59 did not cluster well based on known function, and 634 clustered into 20 ontological categories. Independent validation of differential expression was done for 14 of the putatively Dex-responsive genes across these categories. Results showed that Dex induced rapid translocation of GR into the neutrophil nucleus and signaled dramatic alterations in expression of genes that delay apoptosis, enhance bactericidal activity, and promote tissue remodeling without inflammation or fibrosis. Thus these findings revealed hitherto unappreciated plasticity of blood neutrophils and potentially novel anti-inflammatory/wound-healing actions of glucocorticoids.

Effect of Transport on Physical and Haematological Status of Cattle in Bangladesh

“…Some researcher showed no significant change of TLC after transportation compared to before in short duration (4 hours) of transportation. The proliferation of WBC in present study might be due to stimulating effects of glucocorticoids on white blood cells during long time transportation (Weber et al, 2007). The current study revealed that among the WBC the percentage of lymphocytes were decreased and the percentage of neutrophils was increased after transportation in comparison to before and 24h of post transportation.…”

Invited review: Relationship between cattle transport, immunity and respiratory disease

“…Differentially expressed genes fell into three major functional groups: immune function, apoptosis and wound healing. These expression changes largely correlated with the neutrophil count profile (Table 1), which relates to blood cortisol concentration in numerous models of bovine stress (Burton et al, 2005;Weber et al, 2006;Buckham Sporer et al, 2008). To our knowledge, this is the first study (Buckham Sporer et al, 2008) that has reported transportation-induced changes in the expression of key neutrophil inflammatory and antibacterial genes in association with peak cortisol and neutrophilia stress responses.…”

“…Gene expression regulation results from the binding of cortisol to its GR in the cytoplasm of target cells, with subsequent translocation of hormone-activated receptors into the nucleus and modulation of gene transcription by direct (receptor-DNA) and indirect (receptor-protein-DNA) interactions in regulatory regions of cortisol-sensitive genes (Preisler et al, 2000;Weber et al, 2006). In addition, bovine neutrophils have been shown to exhibit differential expression of genes important to roles of immune function, apoptosis, tissue remodelling, and various metabolic and cellular functions in response to glucocorticoids in vitro and in vivo (Burton et al, 2005).…”

“…The genes selected for profiling were sensitive to glucocorticoids in other stress models (Burton et al, 2005;Weber et al, 2006) and included Fas, A1, MMP-9, L-selectin, bactericidal/permeability-increasing protein (BPI ), transforming growth factor-β receptor type III (subsequently referred to as β-glycan), and GRα. In all, 88 genes were found to be differentially expressed between −24 and 4.5, 9.75 or 14.25 h relative to transport, when cortisol and neutrophilia were at their peaks.…”

Differential stress responses among newly received calves: variations in reductant capacity and Hsp gene expression

“…Neutrophils, crucial phagocytes for the acute defense of the lungs, respond to transportation stress by altering their numbers, migration capacity and function (Murata et al, 1987;Yagi et al, 2004). A large bulk of studies demonstrated that exogenously administrated or endogenously secreted glucocorticoids modulate the expression of neutrophil genes that regulate apoptosis, adhesion and inflammation Burton et al, 2005;Weber et al, 2001Weber et al, , 2006. In a recent study, Buckham Sporer et al (2007) showed that changes in concentrations of plasma cortisol might mediate the effect of transportation stress on altered expression of neutrophils.…”