Amplification of the proinflammatory transcription factor cascade increases with severity of uncontrolled hemorrhage in swine.
BACKGROUND
Hypotension causes diffuse liver injury accompanied by increased local production of interleukin-6 (IL-6) in swine models of uncontrolled hemorrhagic shock (HS). IL-6 is transcriptionally up-regulated by nuclear factor (NF)-kappaB and results in activation of signal transducer and activator of transcription-3 (Stat3) in a murine model of controlled HS. Our objectives were: 1). to determine if increased IL-6 production and NF-kappaB and Stat3 activation occurs in a swine model of uncontrolled HS, and 2). to assess whether or not levels of IL-6 mRNA and activity of NF-kappaB and Stat3 correlate with shock severity.


METHODS
Swine were assigned to four groups: 1). control animals (n = 6): no intervention, 2). sham operation (n = 6): celiotomy and splenectomy, 3). uncontrolled hemorrhagic shock (UHS) (n = 6): sham plus grade V vascular liver injury and resuscitation, 4). profound uncontrolled hemorrhagic shock (PUHS) (n = 8): UHS after dilutional hypothermia. Following euthanasia at 2 h, livers were harvested, total RNA isolated, and IL-6 mRNA levels quantified by Q-RT-PCR (ABI Prism 7700, Applied Biosystems International, Foster City, CA). Protein was extracted for measurement of NF-kappaB and Stat3 activity by electrophoretic mobility shift assay (EMSA).


RESULTS
Compared to shams, IL-6 mRNA levels increased 4.5-fold in UHS and 90-fold in PUHS (P < 0.001). Compared with shams; NF-kappaB activity increased 2-fold in both UHS and PUHS (P < 0.05). Stat3 activity was equivalent (not significant) in UHS when compared with shams but increased 5.3-fold in PUHS. (P < 0.05).


CONCLUSIONS
These findings suggest that regional proinflammatory cytokine production results from and perpetuates a proinflammatory transcription factor cascade in a swine model of uncontrolled hemorrhagic shock and indicate that this process is proportional to the severity of shock.
Brundage
Susan I
SI
Department of Surgery, Stanford University Medical Center, Palo Alto, California 94305, USA. sbrundage@stanford.edu
Schreiber
Martin A
MA
Holcomb
John B
JB
Zautke
Nathan
N
Mastrangelo
Mary Ann
MA
Xq
Xu
X
Macaitis
Joe
J
Tweardy
David J
DJ
D000818:Animals; D004268:DNA-Binding Proteins / Q000378:metabolism; D015850:Interleukin-6 / Q000378:metabolism; D016328:NF-kappa B / Q000378:metabolism; D050796:STAT3 Transcription Factor; D012720:Severity of Illness Index; D012771:Shock, Hemorrhagic / Q000276:immunology*; D013552:Swine; D015534:Trans-Activators / Q000378:metabolism; D014157:Transcription Factors / Q000276:immunology*
D004268:DNA-Binding Proteins; D015850:Interleukin-6; D016328:NF-kappa B; D050796:STAT3 Transcription Factor; D015534:Trans-Activators; D014157:Transcription Factors