Hyperthermia attenuates TNF-alpha-induced up regulation of endothelial cell adhesion molecules in human arterial endothelial cells

Abstract

Background and aim: The activation of NF-κB induces production of inflammatory cytokines and up regulation of endothelial cell adhesion molecules (ECAM). ECAM (e.g., E-selectin, VCAM-1 and ICAM-1) associates to the recruitment of leukocytes into tissue exposed to inflammatory situation. In this study, we investigated the effects of hyperthermia on the activation of NF-κB and the up regulation of E-selectin and VCAM-1 in human endothelial cells stimulated by TNF-α.

Methods: Human arterial endothelial cells (HAEC) were pretreated with hyperthermia for 60 min at 42°C, followed by incubation at 37°C in a passively cooled incubator, before TNF-α stimulation. To assess the effects of hyperthermia on TNF-α-induced up regulation of ECAM and TNF-α-induced activation of NF-κB, we measured ECAM by ELISA, and evaluated the activation of NF-κB by Western blotting after TNF-α stimulation. The accumulation of HO-1, Hsp70 and IκBα in hyperthermia-treated HAEC was also assessed by Western blotting. To investigate the role of Hsp70, we treated HAEC with geranylgeranylacetone (GGA, Hsp70 inducer) 2 h before hyperthermia, and then measured ECAM in TNF-α-stimulated HAEC by ELISA.

Results: Pretreatment of hyperthermia reduced TNF-α-induced up regulation of E-selectin and VCAM-1. In addition, accumulation of Hsp70, HO-1 and IκBα protein were up-regulated after hyperthermia. Furthermore, Western blotting analysis revealed that pretreatment of hyperthermia attenuated TNF-α-induced translocation of p65 into the nuclei of HAEC. Moreover, GGA enhanced Hsp70 accumulation induced by hyperthermia. Hyperthermia pretreatment combined with GGA induced further inhibition of TNF-α-induced up regulation of ECAM when compared with hyperthermia alone.

Conclusion: Pretreatment of hyperthermia blocks TNF-α-induced NF-κB activation, resulting in the inhibition of ECAM up regulation in HAEC.

• Hyperthermia
• heat shock protein
• Hsp70
• heme oxygenase-1
• geranylgeranylacetone (GGA)
• E-selectin
• VCAM-1