title: Tissue and circulating expression of IL-1 family members following heat stroke.
abstract: Interleukin-1 (IL-1) is thought to have a significant role in the pathophysiology of heat stroke (HS), although little is known regarding the actions or expression patterns of the IL-1 family. This study tested the hypotheses that following HS IL-1 family gene expression is dynamic, while loss of IL-1 signaling enhances recovery. IL-1 family expression was determined in plasma, spleen, and liver from C57BL/6J mice (n=24 control, n=20 HS) at maximum core temperature (Tc,Max), hypothermia, and 24 h post-HS (24 h). Soluble IL-1 receptor subtype I (sIL-1RI) protein expression peaked at 24 h (14,659.01±2,016.28 pg/ml, P<0.05), while sIL-1RII peaked at hypothermia (19,099.30±1,177.07 pg/ml). IL-1α gene expression in the spleen (ninefold) and liver (fourfold) along with IL-1RI (threefold spleen and fivefold liver) were maximal at hypothermia. Spleen IL-1β gene expression peaked at Tc,Max (fourfold) but at hypothermia (fourfold) in liver. Gene expression of the IL-1 family member IL-18 peaked (2.5-fold) at Tc,Max but was similar at all other time points. Subsequent studies revealed that despite accruing a greater heating area (298±16 vs. 247±13°C·min, P<0.05), IL-1RI knockout (KO) mice (n=14) showed an attenuated hypothermia depth (28.5±0.2 vs. 27.3±0.5°C, P<0.05) and duration (675±82 vs. 1,283±390 min, P<0.05) with a higher 24 h Tc (36.9 vs. 34.1°C, P<0.05) compared with C57BL/6J mice (n=8). The current results demonstrate that following HS IL-1 family gene expression is altered and IL-1RI KO mice display Tc responses consistent with a more rapid recovery.
authors.affiliation: United States Army Research Institute of Environmental Medicine, Thermal and Mountain Medicine Division, Natick, Massachusetts 01760, USA. Bryan.helwig@us.army.mil
authors.forename: Bryan G
authors.initials: BG
authors.lastname: Helwig
authors.forename: Lisa R
authors.initials: LR
authors.lastname: Leon
mesh_terms: D000818:Animals; D018883:Heat Stroke / Q000097:blood* / Q000378:metabolism*; D007035:Hypothermia / Q000097:blood / Q000378:metabolism; D007375:Interleukin-1 / Q000097:blood* / Q000378:metabolism*; D053582:Interleukin-1alpha / Q000097:blood / Q000378:metabolism; D053583:Interleukin-1beta / Q000097:blood / Q000378:metabolism; D008099:Liver / Q000378:metabolism; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D060888:Real-Time Polymerase Chain Reaction; D017472:Receptors, Interleukin-1 / Q000097:blood / Q000235:genetics / Q000378:metabolism; D013154:Spleen / Q000378:metabolism
chemical_list: D007375:Interleukin-1; D053582:Interleukin-1alpha; D053583:Interleukin-1beta; D017472:Receptors, Interleukin-1