Differential effects of caspase inhibitors on endotoxin-induced myocardial dysfunction and heart apoptosis.
Endotoxin is one of the major factors causing myocardial depression and death during sepsis in humans. Recently, it was reported that endotoxin may induce cardiomyocyte apoptosis. Also, multiple caspase activation has been implicated in endotoxin-induced apoptosis in several organ systems. In this study, we investigated whether endotoxin would increase myocardial caspase activities and evaluated the effects of in vivo administration (3 mg/kg) of the broad-spectrum caspase inhibitor benzyloxycarbonyl-Val-Ala-Asp-fluoromethylketone(z-VAD.fmk), the caspase-3-like inhibitor benzyloxycarbonyl-Asp-Glu-Val-Asp-chloromethylketone (z-DEVD.cmk), and the caspase-1-like inhibitor acetyl-Tyr-Val-Ala-Asp-chloromethylketone (Ac-YVAD. fmk), on endotoxin-induced myocardial dysfunction and apoptosis. Endotoxin administration (10 mg/kg iv) induced myocardial contractile dysfunction that was associated with caspase activity increases and nuclear apoptosis. Broad-spectrum z-VAD.fmk and z-DEVD.cmk improved endotoxin-induced myocardial dysfunction and reduced caspase activation and nuclear apoptosis when given immediately and 2 h after endotoxin. In contrast, no effects of Ac-YVAD.fmk were observed on myocardial function and caspase-induced apoptosis. Administration of caspase inhibitors 4 h after endotoxin treatment was not able to protect the rat heart from myocardial dysfunction and nuclear apoptosis. These observations provide evidence that in our model, caspase activation plays a role in endotoxin-induced myocardial apoptosis. Caspase inhibition strategy may represent a therapeutic approach to endotoxin-induced myocardial dysfunction.
Institut National de la Santé et de la Recherche Médicale U459, Lille Cedex, 59045, France.
H
H
Fauvel
P
P
Marchetti
C
C
Chopin
P
P
Formstecher
R
R
Nevière
D000590:Amino Acid Chloromethyl Ketones / Q000494:pharmacology; D000818:Animals; D017209:Apoptosis / Q000187:drug effects*; D001794:Blood Pressure; D061945:Caspase Inhibitors; D003326:Coronary Circulation / Q000187:drug effects / Q000502:physiology; D015853:Cysteine Proteinase Inhibitors / Q000494:pharmacology*; D053938:DNA Fragmentation; D004731:Endotoxins / Q000633:toxicity*; D006321:Heart / Q000187:drug effects / Q000502:physiology* / Q000503:physiopathology; D006439:Hemodynamics / Q000187:drug effects* / Q000502:physiology; D066298:In Vitro Techniques; D008297:Male; D009200:Myocardial Contraction / Q000187:drug effects; D009206:Myocardium / Q000166:cytology* / Q000473:pathology; D009842:Oligopeptides / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D013997:Time Factors; D016277:Ventricular Function, Left / Q000187:drug effects / Q000502:physiology
D000590:Amino Acid Chloromethyl Ketones; D061945:Caspase Inhibitors; D015853:Cysteine Proteinase Inhibitors; D004731:Endotoxins; C098738:N-acetyl-tyrosyl-valyl-alanyl-aspartyl chloromethyl ketone; D009842:Oligopeptides; C120992:benzyloxycarbonyl aspartyl-glutamyl-valyl-aspartyl-chloromethyl ketone; C096713:benzyloxycarbonylvalyl-alanyl-aspartyl fluoromethyl ketone