G protein-coupled receptor kinase-2 in peripheral blood mononuclear cells following acute mental stress

Aims: This study investigated G-protein-coupled receptor kinase-2 (GRK2) density in peripheral blood mononuclear cells (PBMC) and its relationship to plasma pro-inflammatory cytokine concentrations following acute mental stress. Main methods: Apparently healthymales (n=20; 21.3 +/- 0.55 years) participated in an acute mental stress task. Heart rate was measured at baseline and throughout mental stress. Plasma epinephrine (EPI), norepinephrine (NE), tumor necrosis factor-alpha (TNF-alpha) and interleukin-6 (IL-6) were assessed via enzyme-linked immunosorbent assays before, immediately following, and 30, 60 and 120min after the mental stress task. GRK2 density was measured by western blot technique at the same time points. Key findings: Acute mental stress elicited significant elevations in HR, and plasma EPI and NE. Additionally, GRK2 density increased significantly across time following the stress task. Post hoc analyses revealed that GRK2 density was significantly elevated at 30 and 60 min following acute stress. A significant positive correlation was observed between GRK2 density and plasma EPI, while a significant negative correlation was revealed between GRK2 density and TNF-alpha across all time points. Significance: Acute mental stress significantly increased GRK2 density in PBMCs of young adult males. Furthermore, although plasma IL-6 and TNF-alpha did not change following mental stress, it remains unknown whether a longer time period was needed to observe a pro-inflammatory state associated with the desensitization of beta-adrenergic receptor activity. Our findings that GRK2 expression is promptly increased in PBMC following an acute stress task, may suggest a link between stress and intracellular inflammatory signaling. (C) 2015 Elsevier Inc. All rights reserved.