Human serum from patients with septic shock activates transcription factors STAT1, IRF1, and NF-kappaB and induces apoptosis in human cardiac myocytes.
Proinflammatory cytokines have been linked to depression of myocardial contractility in vivo in patients with acute septic shock and in vitro models employing isolated myocytes exposed to serum from such patients. The key pathways involved in mediating this septic organ dysfunction (cell adhesion molecule expression, inducible nitric-oxide synthase induction, and apoptosis) are known to be regulated by transcription factors STAT1, IRF1, and NF-kappaB. Utilizing a model that mimics human disease, we have demonstrated activation of the transcription factors STAT1, IRF1, and NF-kappaB in human fetal myocytes exposed to human septic serum. Both reporter and electrophoretic mobility shift assays demonstrated a 5-19-fold increase in activation of transcription factors STAT1, IRF1, and NF-kappaB in response to incubation with human septic serum. The addition of human septic serum to human fetal myocytes induced apoptosis in human fetal myocytes and activation of the mitogen-activated protein kinase c-Jun NH -terminal kinase and caspase 1 as measured by Western blot. These data suggest that transcription factor activation and early myocyte apoptosis play a mechanistic role in septic myocardial depression and sepsis-induced organ dysfunction.
Kumar
Aseem
A
Department of Chemistry and Biochemistry and the Biomolecular Sciences Programme, Laurentian University, Sudbury, Ontario P3E 2C6, Canada. akumar@laurentian.ca
Kumar
Anand
A
Michael
Paul
P
Brabant
Danielle
D
Parissenti
Amadeo M
AM
Ramana
Chilakamarti V
CV
Xu
Xiulong
X
Parrillo
Joseph E
JE
D000328:Adult; D017209:Apoptosis; D015153:Blotting, Western; D020170:Caspase 1 / Q000378:metabolism; D015815:Cell Adhesion Molecules / Q000378:metabolism; D004247:DNA / Q000378:metabolism; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005333:Fetus / Q000378:metabolism; D017930:Genes, Reporter; D006801:Humans; D015151:Immunoblotting; D007249:Inflammation; D050856:Interferon Regulatory Factor-1 / Q000378:metabolism*; D007375:Interleukin-1 / Q000097:blood; D048031:JNK Mitogen-Activated Protein Kinases / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D048055:Mitogen-Activated Protein Kinase 8 / Q000378:metabolism; D048056:Mitogen-Activated Protein Kinase 9 / Q000378:metabolism; D009206:Myocardium / Q000473:pathology; D032383:Myocytes, Cardiac / Q000378:metabolism / Q000473:pathology*; D016328:NF-kappa B / Q000378:metabolism*; D050794:STAT1 Transcription Factor / Q000378:metabolism*; D018805:Sepsis; D012772:Shock, Septic / Q000097:blood*; D014157:Transcription Factors / Q000378:metabolism; D014158:Transcription, Genetic; D014162:Transfection; D014343:Trypan Blue / Q000494:pharmacology; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis
D015815:Cell Adhesion Molecules; C494257:IRF1 protein, human; D050856:Interferon Regulatory Factor-1; D007375:Interleukin-1; D016328:NF-kappa B; D050794:STAT1 Transcription Factor; D014157:Transcription Factors; D014409:Tumor Necrosis Factor-alpha; D004247:DNA; D048056:Mitogen-Activated Protein Kinase 9; D048031:JNK Mitogen-Activated Protein Kinases; D048055:Mitogen-Activated Protein Kinase 8; D020170:Caspase 1; D014343:Trypan Blue