Apoptotic signaling induces hyperpermeability following hemorrhagic shock.
Hemorrhagic shock (HS) disrupts the endothelial cell barrier, resulting in microvascular hyperpermeability. Recent studies have also demonstrated that activation of the apoptotic signaling cascade is involved in endothelial dysfunction, which may result in hyperpermeability. Here we report involvement of the mitochondrial "intrinsic" pathway in microvascular hyperpermeability following HS in rats. HS resulted in the activation of the mitochondrial intrinsic pathway, as is evident from an increase in the proapoptotic Bcl-2 family member BAK, release of mitochondrial cytochrome c into the cytoplasm, and activation of caspase-3. This, along with the in vivo transfection of the proapoptotic peptide BAK (BH3), resulted in hyperpermeability (as visualized by intravital microscopy), release of mitochondrial cytochrome c into the cytoplasm, and activation of caspase-3. Conversely, transfection of the BAK (BH3) mutant had no effect on hyperpermeability. Together, these results demonstrate involvement of the mitochondrial intrinsic apoptotic pathway in HS-induced hyperpermeability and that the attenuation of this pathway may provide an alternative strategy in preserving vascular barrier integrity.
Childs
Ed W
EW
Department of Surgery, The Texas A & M University, HSC College of Medicine, Scott & White Memorial Hospital, 2401 South 31st St., Temple, TX 76508, USA. echilds@swmail.sw.org
Tharakan
Binu
B
Hunter
Felicia A
FA
Tinsley
John H
JH
Cao
Xiaobo
X
D000818:Animals; D017209:Apoptosis; D002199:Capillary Permeability; D053148:Caspase 3 / Q000378:metabolism; D061945:Caspase Inhibitors; D015853:Cysteine Proteinase Inhibitors / Q000494:pharmacology; D045304:Cytochromes c / Q000378:metabolism; D004195:Disease Models, Animal; D004730:Endothelium, Vascular / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology*; D004789:Enzyme Activation; D008297:Male; D053078:Membrane Potential, Mitochondrial; D008643:Mesentery / Q000098:blood supply*; D008833:Microcirculation / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology; D018715:Microscopy, Video; D008928:Mitochondria / Q000378:metabolism / Q000473:pathology; D009842:Oligopeptides / Q000494:pharmacology; D010446:Peptide Fragments / Q000235:genetics / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D012771:Shock, Hemorrhagic / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology*; D015398:Signal Transduction; D014162:Transfection; D050998:bcl-2 Homologous Antagonist-Killer Protein / Q000235:genetics / Q000378:metabolism*; D014841:von Willebrand Factor / Q000378:metabolism
C494774:Bak1 protein, rat; D061945:Caspase Inhibitors; D015853:Cysteine Proteinase Inhibitors; D009842:Oligopeptides; D010446:Peptide Fragments; D050998:bcl-2 Homologous Antagonist-Killer Protein; C110772:benzoylcarbonyl-aspartyl-glutamyl-valyl-aspartyl-fluoromethyl ketone; D014841:von Willebrand Factor; D045304:Cytochromes c; C505410:Casp3 protein, rat; D053148:Caspase 3