Heat stress modulates hepatocyte membrane proteins during endotoxemia.
BACKGROUND
Hepatic failure following sepsis is one of the important features of burns. Studies have shown that in septic rats, heat stress (HS) has a protective effect on bile acid transporters in hepatocyte membranes. This study investigates the influence of HS on hepatocyte membrane proteins during endotoxemia using 2D gel electrophoresis.


METHODS
Endotoxemia in rats was induced by intraperitoneal injection of Escherichia coli lipopolysaccharide (LPS) (n=24), while control rats (n=24) received saline. Twelve rats from each group were exposed to HS 2h prior to LPS or saline injection by external warming to 42 degrees C for 10 min and 12 rats in each group were exposed to ambient temperature 2h prior to LPS or saline injection. Membrane fractions were extracted 12, 24 and 72 h after LPS or saline treatment. Extracted proteins were separated using 2D gel electrophoresis. The most dominant spots were analyzed by MALDI-TOF-MS.


RESULTS
Two-dimensional gel electrophoresis differentially identified expressed proteins in all treatment groups. The majority of the spots developed 24h after injection. Membrane proteins; Wnt 13, ribosomal protein L14, VLCAD, BHMT and HIT-40 were found only in HS-LPS. Protein profiles of the groups returned to normal after 72 h.


CONCLUSIONS
We propose that HS during endotoxemia changes hepatic membrane proteins expression, which are involved in metabolism.
Przkora
Rene
R
Shriners Hospital for Children and Department of Surgery, University of Texas Medical Branch, Galveston, TX 77550, USA. przkora@yahoo.com
Haslbeck
Martin
M
Jeschke
Marc G
MG
Heyde
Christoph
C
Ertel
Wolfgang
W
Herndon
David N
DN
Bolder
Ulrich
U
D000818:Animals; D015180:Electrophoresis, Gel, Two-Dimensional; D019446:Endotoxemia / Q000378:metabolism*; D004926:Escherichia coli; D018882:Heat Stress Disorders / Q000378:metabolism*; D022781:Hepatocytes / Q000378:metabolism*; D008070:Lipopolysaccharides / Q000494:pharmacology; D008297:Male; D008565:Membrane Proteins / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D015854:Up-Regulation
D008070:Lipopolysaccharides; D008565:Membrane Proteins