title: Effects of IL-10 and age on IL-6, IL-1beta, and TNF-alpha responses in mouse skeletal and cardiac muscle to an acute inflammatory insult.
abstract: Exaggerated proinflammatory cytokine responses can be observed with aging, and reduced levels of the anti-inflammatory cytokine IL-10 may contribute to these responses. IL-10 can reduce IL-6, IL-1beta, and TNF-alpha expression in nonmuscle tissues; however, no studies have examined the combined effects of IL-10 and age on cytokine responses in skeletal and cardiac muscle. These experiments tested the hypothesis that the absence of IL-10, in vivo, is associated with greater IL-6, TNF-alpha, and IL-1beta responses to an inflammatory challenge in skeletal and cardiac muscle and that aging exaggerates these responses. We compared IL-6, IL-1beta, and TNF-alpha mRNA and protein levels in skeletal and cardiac muscle of young (4 mo) and mature (10-11 mo) wild-type (IL-10(+/+)) and IL-10 deficient (IL-10(-/-)) mice following LPS. Skeletal and cardiac IL-6 mRNA and protein were elevated by LPS for IL-10(+/+) and IL-10(-/-) mice with greater responses in the IL-10(-/-) mice (P < 0.01). In skeletal muscle these effects were greater in mature than young mice (P < 0.01). IL-1beta mRNA and protein responses to LPS were greater in cardiac muscle of young but not mature IL-10(-/-) mice compared with IL-10(+/+) (P < 0.01). However, IL-1beta responses were greater in mature than young mice, but only in IL-10(+/+) groups (P < 0.05). The absence of IL-10 was associated with higher TNF-alpha protein levels in cardiac muscle (P < 0.05). The results provide the first in vivo evidence that the absence of IL-10 is associated with a greater IL-6 response to LPS in skeletal and cardiac muscles, and in skeletal muscle aging further exaggerates these responses.
authors.affiliation: Departments of Kinesiology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA.
authors.forename: B M
authors.initials: BM
authors.lastname: Meador
authors.forename: C P
authors.initials: CP
authors.lastname: Krzyszton
authors.forename: R W
authors.initials: RW
authors.lastname: Johnson
authors.forename: K A
authors.initials: KA
authors.lastname: Huey
mesh_terms: D000375:Aging / Q000502:physiology*; D000818:Animals; D001835:Body Weight / Q000502:physiology; D016753:Interleukin-10 / Q000494:pharmacology*; D053583:Interleukin-1beta / Q000097:blood*; D015850:Interleukin-6 / Q000097:blood*; D008070:Lipopolysaccharides / Q000494:pharmacology; D008297:Male; D051379:Mice; D009124:Muscle Proteins / Q000378:metabolism; D018482:Muscle, Skeletal / Q000378:metabolism*; D009205:Myocarditis / Q000139:chemically induced / Q000378:metabolism*; D009206:Myocardium / Q000378:metabolism*; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism*
chemical_list: D053583:Interleukin-1beta; D015850:Interleukin-6; D008070:Lipopolysaccharides; D009124:Muscle Proteins; D012333:RNA, Messenger; D014409:Tumor Necrosis Factor-alpha; D016753:Interleukin-10