Glucocorticoid effects on pro-inflammatory cytokines gene expression in human peripheral blood neutrophils and neutrophil-depleted leukocytes.

<p>Neutrophils and neutrophil depleted leukocytes were isolated from the blood of 4 healthy human volunteers and were incubated for 5 h with or without lipopolysaccharide (LPS; 100 ng/mL) alone or combined with dexamethasone (DEX) at 10⁻⁶ M. Following culture, mRNA expression of proinflammatory cytokines (IL-1β, TNF-α and IL-8) was quantified by qPCR. Absolute values were corrected using GAPDH as a reference gene. A. Gene expression was reported as the relative variation (fold increase) to unstimulated cell mRNA levels (arbitrary value of 1). Bars represent means. *Significant effect of treatment over LPS-stimulated cells (p≤0.050). B. Dexamethasone percentage of inhibition on LPS-induced mRNA expression was compared between cell populations. A 100% inhibition means that mRNA expression returned to unstimulated cell basal mRNA level. Bars represent means. †Significant effect of treatment between cell populations (p = 0.048).