Surviving sepsis: bcl-2 overexpression modulates splenocyte transcriptional responses in vivo.
We hypothesized that spleen microarray gene expression profiles analyzed with contemporary pathway analysis software would provide molecular pathways of interest and target genes that might help explain the effect of bcl-2 on improving survival during sepsis. Two mouse models of sepsis, cecal ligation and puncture and tracheal instillation of Pseudomonas aeruginosa, were tested in both wild-type mice and mice that overexpress bcl-2. Whole spleens were obtained 6 h after septic injury. DNA microarray transcriptional profiles were obtained using the Affymetrix 430A GeneChip, containing 22,690 elements. Ingenuity Pathway Analysis software was used to construct hypothetical transcriptional networks that changed in response to sepsis and expression of the bcl-2 transgene. A conservative approach was used wherein only changes induced by both abdominal and pulmonary sepsis were studied. At 6 h, sepsis induced alterations in the abundance of hundreds of spleen genes, including a number of proinflammatory mediators (e.g., interleukin-6). These sepsis-induced alterations were blocked by expression of the bcl-2 transgene. Network analysis implicated a number of bcl-2-related apoptosis genes, including bcl2L11 (bim), bcl-2L2 (bcl-w), bmf, and mcl-1. Sepsis in bcl-2 transgenic animals resulted in alteration of RNA abundance for only a single gene, ceacam1. These findings are consistent with sepsis-induced alterations in the balance of pro- and anti-apoptotic transcriptional networks. In addition, our data suggest that the ability of bcl-2 overexpression to improve survival in sepsis in this model is related in part to prevention of sepsis-induced alterations in spleen transcriptional responses.
Wagner
Tracey H
TH
Department of Anesthesiology, School of Medicine, Washington University in St. Louis, St. Louis, MO 63110, USA.
Drewry
Anne M
AM
Macmillan
Sandra
S
Dunne
W Michael
WM
Chang
Katherine C
KC
Karl
Irene E
IE
Hotchkiss
Richard S
RS
Cobb
J Perren
JP
D000818:Animals; D004195:Disease Models, Animal; D015870:Gene Expression; D020869:Gene Expression Profiling; D006579:Heterozygote; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D020411:Oligonucleotide Array Sequence Analysis; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000235:genetics / Q000378:metabolism*; D018805:Sepsis / Q000235:genetics*; D013154:Spleen / Q000166:cytology / Q000378:metabolism*; D015996:Survival Rate; D013997:Time Factors; D014158:Transcription, Genetic; D019076:Transgenes
D019253:Proto-Oncogene Proteins c-bcl-2