• Open Access

Aging is associated with greater nuclear NFκB, reduced IκBα, and increased expression of proinflammatory cytokines in vascular endothelial cells of healthy humans

Authors



Anthony J. Donato, PhD, Department of Integrative Physiology, University of Colorado at Boulder, 354 UCB, Boulder, CO 80309, USA. Tel.: +303 492-4568; fax: +303 492-6778; e-mail: tony.donato@colorado.edu

Summary

The vascular endothelium may develop a proinflammatory profile with aging, but evidence is limited in humans. Expression of inflammatory proteins was determined in vascular endothelial cells (EC) obtained from peripheral veins of 24 young (23 ± 1 years, mean ± SE) and 36 older (63 ± 1) healthy men and women using quantitative immunofluorescence. The older subjects had lower vascular endothelium-dependent dilation (forearm blood flow responses to acetylcholine, p < 0.05), and higher plasma concentrations of C-reactive protein, interleukin-6 (IL-6), and oxidized low-density lipoprotein (all p < 0.05), but not tumor necrosis factor-α (TNF-α). Total (O: 0.52 ± 0.04 vs. Y: 0.33 ± 0.05 NFκB/HUVEC intensity, p < 0.05) and nuclear (O: 0.59 ± 0.04 vs. Y: 0.41 ± 0.04) expression of nuclear factor κ B p65 (NFκB), a proinflammatory gene transcription factor, was greater in EC from the older subjects (p < 0.05). EC expression of the inhibitor (of nuclear translocation) of NFκB (IκBα) was lower in the older subjects (O: 0.16 ± 0.02 vs. Y: 0.24 ± 0.03, p < 0.05), whereas IκB kinase (IκK) was not different. EC expression of the proinflammatory proteins IL-6 (O: 0.42 ± 0.06 vs. Y: 0.29 ± 0.03, p < 0.05), TNF-α (O: 0.52 ± 0.06 vs. Y: 0.33 ± 0.05, p < 0.05) and monocyte chemoattractant protein 1 (MCP-1) (O: 0.59 ± 0.06 vs. Y: 0.38 ± 0.02, p < 0.05) was greater in the older subjects, whereas cyclooxygenase 2 and the receptor for advanced glycation end-products did not differ. These findings indicate that impaired function with aging in healthy adults is associated with the development of a proinflammatory phenotype in the vascular endothelium that could be caused in part by reduced IκB-mediated inhibition of NFκB.

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