In vivo delivery of caspase-8 or Fas siRNA improves the survival of septic mice.
Although studies have shown increased evidence of death receptor-driven apoptosis in intestinal lymphoid cells, splenocytes, and the liver following the onset of polymicrobial sepsis, little is known about the mediators controlling this process or their pathologic contribution. We therefore attempted to test the hypothesis that the hydrodynamic administration of small interfering RNA (siRNA) against the death receptor, Fas or caspase-8, should attenuate the onset of morbidity and mortality seen in sepsis, as produced by cecal ligation and puncture (CLP). We initially show that in vivo administration of green fluorescent protein (GFP) siRNA in GFP transgenic mice results in a decrease in GFP fluorescence in most tissues. Subsequently, we also found that treating septic nontransgenic mice with siRNA targeting Fas or caspase-8 but not GFP (used as a control here) decreased the mRNA, in a sustained fashion up to 10 days, and protein expression of Fas and caspase-8, respectively. In addition, transferase-mediated dUTP (deoxyuridine triphosphate) nick end labeling (TUNEL) and active caspase-3 analyses revealed a decrease in apoptosis in the liver and spleen but not the thymus following siRNA treatment. Indices of liver damage were also decreased. Finally, the injection of Fas or caspase-8 given not only 30 minutes but up to 12 hours after CLP significantly improved the survival of septic mice.
Wesche-Soldato
Doreen E
DE
Division of Surgical Research, Department of Surgery, Brown University School of Medicine, Providence, RI, USA.
Chung
Chun-Shiang
CS
Lomas-Neira
Joanne
J
Doughty
Lesley A
LA
Gregory
Stephen H
SH
Ayala
Alfred
A
D000818:Animals; D017209:Apoptosis; D015153:Blotting, Western; D053148:Caspase 3; D053181:Caspase 8; D020169:Caspases / Q000235:genetics* / Q000378:metabolism; D005260:Female; D020868:Gene Silencing; D018014:Gene Transfer Techniques; D015316:Genetic Therapy / Q000379:methods; D049452:Green Fluorescent Proteins / Q000378:metabolism; D020287:In Situ Nick-End Labeling; D007371:Interferon-gamma / Q000378:metabolism; D015850:Interleukin-6 / Q000378:metabolism; D008099:Liver / Q000201:enzymology / Q000378:metabolism; D008297:Male; D051379:Mice; D008809:Mice, Inbred C3H; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D012333:RNA, Messenger / Q000378:metabolism; D034741:RNA, Small Interfering / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D018805:Sepsis / Q000401:mortality / Q000628:therapy*; D013154:Spleen / Q000378:metabolism; D013997:Time Factors; D014018:Tissue Distribution; D019014:fas Receptor / Q000235:genetics* / Q000378:metabolism
D015850:Interleukin-6; D012333:RNA, Messenger; D034741:RNA, Small Interfering; D019014:fas Receptor; D049452:Green Fluorescent Proteins; D007371:Interferon-gamma; C505409:Casp3 protein, mouse; C505526:Casp8 protein, mouse; D053148:Caspase 3; D053181:Caspase 8; D020169:Caspases