Reduced basal levels and enhanced LPS response of IL-6 mRNA in aged mice.
Senescence is a complex and multifactorial process that may predispose organisms to altered responses to environmental stressors. The cytokine interleukin-6 (IL-6) is expressed by a variety of cells and is one of the earliest mediators of the acute inflammatory response. In this study, the level of IL-6 mRNA in younger (7 months) and old (23 months) mice was determined in the tissue of several organs with or without stimulation with lipopolysaccharide (LPS). Whereas younger animals had a basal expression of IL-6 mRNA in all organs, this was undetectable in the old animals. In contrast, when the mice were injected with LPS, in a majority of the organ tissues there was a robust stimulation of IL-6 mRNA in the old mice whereas the younger animals had a more variable response. These data indicate that the aging process may predispose animals to an exaggerated and potentially harmful inflammatory response.
Sharman
K
K
Center for Occupational and Environmental Health, Department of Community and Environmental Medicine, University of California, Irvine, CA 92697-1825, USA.
Sharman
E
E
Campbell
A
A
Bondy
S C
SC
D000375:Aging / Q000378:metabolism*; D000818:Animals; D015850:Interleukin-6 / Q000235:genetics*; D008070:Lipopolysaccharides / Q000494:pharmacology*; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains; D012333:RNA, Messenger / Q000378:metabolism*; D014018:Tissue Distribution
D015850:Interleukin-6; D008070:Lipopolysaccharides; D012333:RNA, Messenger