Previous heat shock facilitates the glutamine-induced expression of heat-shock protein 72 in septic liver.
OBJECTIVE
This study investigated the effects of glutamine administration on the expression of the heat-shock protein 72 (Hsp72) in the liver during sepsis. The role of heat-shock factor 1 (HSF-1) was analyzed for possible mechanisms to the phenomenon.


METHODS
Male Sprague-Dawley rats were subjected to sepsis by cecal ligation and puncture (CLP). Heat-shock treatment was applied to the rats' whole body using an electric heating pad 24 h before CLP. Glutamine or saline was administered 1 h after initiation of sepsis by tail vein injection. The Hsp72 and HSF-1 expressions were detected using western blot analysis, and Hsp72 mRNA expression was measured using reverse transcription-polymerase chain reaction.


RESULTS
The Hsp72 content noticeably increased in the livers of preheated rats supplied by glutamine 1 h after sepsis. However, no further synthesis of Hsp72 was found in septic livers or sham glutamine-treated livers. Hsp72, which was induced by preheating, decreased with time, whereas a large amount of Hsp72 could be detected by glutamine administration. Reverse transcription-polymerase chain reaction data indicated that Hsp72 mRNA could be detected only in the group treated with preheating and glutamine administration. The translocation of HSF-1 occurred significantly during sepsis in preheated and non-preheated rats. However, only the preheated group showed the phosphorylation in HSF-1. With the administration of glutamine, the nuclear accumulation of phosphorylated HSF-1 was observed to decline significantly 9 and 18 h after CLP when the Hsp72 mRNA became detectable.


CONCLUSIONS
These results demonstrated that Hsp72 could be induced by glutamine in septic liver only if the liver was preconditioned by heat-shock response. The selective facilitating effect might depend on the accumulation of intranuclear phosphorylated HSF-1 caused by previous heat-shock treatment.
Wang
Shu-Jung
SJ
Department of Physiology, Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung City, Taiwan.
Chen
Hsiang-Wen
HW
Huang
Maw-Hsiung
MH
Yang
Rei-Cheng
RC
D000818:Animals; D015153:Blotting, Western; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D004195:Disease Models, Animal; D005786:Gene Expression Regulation / Q000187:drug effects; D005973:Glutamine / Q000494:pharmacology*; D050884:HSP72 Heat-Shock Proteins / Q000235:genetics / Q000378:metabolism*; D000076249:Heat Shock Transcription Factors; D018869:Heat-Shock Response / Q000187:drug effects*; D008297:Male; D010766:Phosphorylation; D012333:RNA, Messenger / Q000378:metabolism; D011897:Random Allocation; D051381:Rats; D017207:Rats, Sprague-Dawley; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods; D018805:Sepsis / Q000235:genetics / Q000378:metabolism*; D013997:Time Factors; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism
D004268:DNA-Binding Proteins; D050884:HSP72 Heat-Shock Proteins; D000076249:Heat Shock Transcription Factors; D012333:RNA, Messenger; D014157:Transcription Factors; D005973:Glutamine