title: Expression of apoptosis regulatory factors during myocardial dysfunction in endotoxemic rats.
abstract: OBJECTIVE
  To document the time course of apoptosis pathway activation in sepsis and to determine whether Bcl-2 overexpression would improve endotoxin-induced myocardial dysfunction and mortality rate.
  
  
  METHODS
  Randomized, controlled trial.
  
  
  METHODS
  Experimental laboratory.
  
  
  METHODS
  Male Sprague Dawley rats, wild-type C57BL/6 female mice, C57BL/6 female mice overexpressing Bcl-2.
  
  
  METHODS
  Hearts were isolated from rats treated with endotoxin (10 mg/kg, intravenously) to perform heart function, immunohistochemistry (terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick 3'-end labeling, caspase 3), RNase protection assay, reverse transcriptase polymerase chain reaction, Western blotting (caspase 3), and radiolabeled annexin V studies. Twenty-four hours before endotoxin challenge (10 mg/kg, intravenously), rats were pretreated with saline or endotoxin (0.5 mg/kg, intraperitoneally), with or without parthenolide (1 mg/kg, intraperitoneally). Isolated hearts were used to test myocardial function. Mortality induced by endotoxin (10 mg/kg, intraperitoneally) was tested on wild-type or mice overexpressing Bcl-2.
  
  
  RESULTS
  Endotoxin-induced heart dysfunction was maximal at 4 and 8 hrs postinjection, started to improve, and was fully restored at 24 hrs after endotoxin treatment. Endotoxin also induced phosphatidylserine outer leaflet membrane exposure, caspase 3 activation, nuclear apoptosis, and changes in apoptosis gene expression. Bcl-2 overexpression induced by endotoxin pretreatment prevented endotoxin-induced myocardial dysfunction. Mice overexpressing Bcl-2 had dramatic improvement in survival rate compared with wild-type mice.
  
  
  CONCLUSIONS
  These observations suggest that both death receptor and caspase-mediated apoptosis processes are activated in this sepsis model. Bcl-2 overexpression before endotoxin challenge prevents myocardial dysfunction in rats and improves survival rate in mice.
authors.affiliation: Département de Physiologie, Faculté de Médecine, Université de Lille 2, Lille, France.
authors.forename: Steve
authors.initials: S
authors.lastname: Lancel
authors.forename: Patrice
authors.initials: P
authors.lastname: Petillot
authors.forename: Raphael
authors.initials: R
authors.lastname: Favory
authors.forename: Nicolas
authors.initials: N
authors.lastname: Stebach
authors.forename: Christophe
authors.initials: C
authors.lastname: Lahorte
authors.forename: Pierre Marie
authors.initials: PM
authors.lastname: Danze
authors.forename: Benoît
authors.initials: B
authors.lastname: Vallet
authors.forename: Philippe
authors.initials: P
authors.lastname: Marchetti
authors.forename: Remi
authors.initials: R
authors.lastname: Neviere
mesh_terms: D000818:Animals; D017209:Apoptosis; D009202:Cardiomyopathies / Q000503:physiopathology*; D053148:Caspase 3; D020169:Caspases / Q000378:metabolism; D004731:Endotoxins; D005260:Female; D015870:Gene Expression; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D009206:Myocardium / Q000166:cytology / Q000473:pathology; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism*; D011897:Random Allocation; D051381:Rats; D017207:Rats, Sprague-Dawley; D018805:Sepsis / Q000235:genetics / Q000401:mortality / Q000503:physiopathology*; D016019:Survival Analysis
chemical_list: D004731:Endotoxins; D019253:Proto-Oncogene Proteins c-bcl-2; C505409:Casp3 protein, mouse; C505410:Casp3 protein, rat; D053148:Caspase 3; D020169:Caspases