Hsp-72, a candidate prognostic indicator of heatstroke.
Exposure of rats to environmental heat enhances the expression of heat shock protein-72 (Hsp-72) in most of their organs proportionally to heat stress severity. Pre-induction or over-expression of Hsp-72 prevents organ damage and lethality, suggesting that heat shock proteins (Hsps) may have a pathogenic role in this condition. We investigated the expression profile of Hsps in baboons subjected to environmental heat stress until the core temperature attained 42.5 degrees C (moderate heatstroke) or occurrence of hypotension associated with core temperature > or = 43.5 degrees C (severe heatstroke). Western blot analysis demonstrated a differential induction of Hsp-72 among organs of heat-stressed animals with the highest induction in the liver and the lowest in lung. Hsp-60 and Hsc-70 expression was similar between control and heat-stressed animals. ELISA studies indicated a marked release of Hsp-72 into the circulation of baboons with severe heatstroke with a peak at 24 h post-heatstroke onset and remained sustained up to 72 h. Hsp-72 release was not associated with core temperature or systolic blood pressure, but correlated with markers of liver, myocardium, and skeletal muscle tissue necrosis. Non-survivors displayed significantly higher Hsp-72 levels than survivors. No Hsp-60 was detected in the circulation. These findings add further evidence that increased expression of Hsp-72 may be an important component of the host response to severe heatstroke. They also suggest that extracellular Hsp-72 is a marker of multiple organs tissue damage. Whether extracellular Hsp-72 plays a role in the host immune response to heat stress merits further studies.
Dehbi
Mohammed
M
Department of Comparative Medicine, King Faisal Specialist Hospital and Research Centre, Riyadh 11211, Saudi Arabia. mdehbi@dcrtd.org.kw
Baturcam
Engin
E
Eldali
Abdelmoneim
A
Ahmed
Maqbool
M
Kwaasi
Aaron
A
Chishti
Muhammad Azhar
MA
Bouchama
Abderrezak
A
D000818:Animals; D015153:Blotting, Western; D004797:Enzyme-Linked Immunosorbent Assay; D005334:Fever / Q000378:metabolism; D050884:HSP72 Heat-Shock Proteins / Q000378:metabolism*; D018883:Heat Stroke / Q000378:metabolism*; D010215:Papio
D050884:HSP72 Heat-Shock Proteins