Bim siRNA decreases lymphocyte apoptosis and improves survival in sepsis.
To assess the degree of lymphocyte apoptosis and survival in mice treated with small interfering RNA (siRNA) targeted to Bim, a proapoptotic molecule from the Bcl-2 family, within a clinically relevant model of sepsis. C57BL/6 mice were treated with a single dose of Bim siRNA complexed in cationic liposomes via tail vein injection. Approximately 24 h later, mice were subjected to either cecal ligation and puncture (CLP) or sham surgery. Animals were killed at 20 h postsurgery, and spleens were harvested for fluorescence-activated cell sorting analysis using terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end-labeling as a marker for apoptosis. A second cohort of mice was followed for survival for 7 days. The degree of lymphocyte apoptosis in Bim siRNA-treated mice was markedly decreased compared with controls. Fluorescent activated cell sorter analysis demonstrated 13.1% +/- 1.2% B-cell apoptosis and 11.5% +/- 1.5% T-cell apoptosis in control mice compared with 2.7% +/- 0.4% B-cell apoptosis and 3.9% +/- 0.3% T-cell apoptosis in Bim siRNA-treated mice after CLP (P < 0.001 and P < 0.01, respectively). This striking difference in lymphocyte apoptosis correlated with a significant survival advantage in Bim siRNA-treated mice. At 7 days, there was 90% overall survival in Bim siRNA-treated septic mice compared with 50% overall survival in control septic mice (P < 0.05). Treatment with Bim siRNA in vivo has the potential to be an effective therapy in the treatment of sepsis.
Schwulst
Steven J
SJ
Department of Surgery, Washington University School of Medicine, St Louis, MO 63110, USA.
Muenzer
Jared T
JT
Peck-Palmer
Octavia M
OM
Chang
Katherine C
KC
Davis
Christopher G
CG
McDonough
Jacquelyn S
JS
Osborne
Dale F
DF
Walton
Andrew H
AH
Unsinger
Jacqueline
J
McDunn
Jonathan E
JE
Hotchkiss
Richard S
RS
D000818:Animals; D017209:Apoptosis / Q000235:genetics* / Q000528:radiation effects; D051017:Apoptosis Regulatory Proteins / Q000037:antagonists & inhibitors / Q000172:deficiency / Q000235:genetics*; D000072224:Bcl-2-Like Protein 11; D002478:Cells, Cultured; D004195:Disease Models, Animal; D005720:Gamma Rays; D006801:Humans; D008214:Lymphocytes / Q000378:metabolism / Q000473:pathology* / Q000528:radiation effects; D008297:Male; D008565:Membrane Proteins / Q000037:antagonists & inhibitors / Q000172:deficiency / Q000235:genetics*; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D008822:Mice, Transgenic; D010538:Peritonitis / Q000378:metabolism / Q000401:mortality / Q000628:therapy; D011518:Proto-Oncogene Proteins / Q000037:antagonists & inhibitors / Q000172:deficiency / Q000235:genetics*; D034741:RNA, Small Interfering / Q000502:physiology*; D018805:Sepsis / Q000378:metabolism / Q000401:mortality* / Q000628:therapy*; D016019:Survival Analysis
D051017:Apoptosis Regulatory Proteins; C000606775:BCL2L11 protein, human; D000072224:Bcl-2-Like Protein 11; C000606776:Bcl2l11 protein, mouse; D008565:Membrane Proteins; D011518:Proto-Oncogene Proteins; D034741:RNA, Small Interfering