Stress-induced modulation of NF-κB activation, inflammation-associated gene expression, and cytokine levels in blood of healthy men

Abstract

Acute psychosocial stress stimulates transient increases in circulating pro-inflammatory plasma cytokines, but little is known about stress effects on anti-inflammatory cytokines or underlying mechanisms. We investigated the stress kinetics and interrelations of pro- and anti-inflammatory measures on the transcriptional and protein level. Forty-five healthy men were randomly assigned to either a stress or control group. While the stress group underwent an acute psychosocial stress task, the second group participated in a non-stress control condition. We repeatedly measured before and up to 120. min after stress DNA binding activity of the pro-inflammatory transcription factor NF-κB (NF-κB-BA) in peripheral blood mononuclear cells, whole-blood mRNA levels of NF-κB, its inhibitor IκBα, and of the pro-inflammatory cytokines interleukin (IL)-1ß and IL-6, and the anti-inflammatory cytokine IL-10. We also repeatedly measured plasma levels of IL-1ß, IL-6, and IL-10.Compared to non-stress, acute stress induced significant and rapid increases in NF-κB-BA and delayed increases in plasma IL-6 and mRNA of IL-1ß, IL-6, and IκBα (p's < .045). In the stress group, significant increases over time were also observed for NF-κB mRNA and plasma IL-1ß and IL-10 (p's < .055). NF-κB-BA correlated significantly with mRNA of IL-1β (r = .52, p = .002), NF-κB (r = .48, p = .004), and IκBα (r = .42, p = .013), and marginally with IL-6 mRNA (r = .31, p = .11). Plasma cytokines did not relate to NF-κB-BA or mRNA levels of the respective cytokines.Our data suggest that stress induces increases in NF-κB-BA that relate to subsequent mRNA expression of pro-inflammatory, but not anti-inflammatory cytokines, and of regulatory-cytoplasmic-proteins. The stress-induced increases in plasma cytokines do not seem to derive from de novo synthesis in circulating blood cells.