CD14-dependent modulation of NF-kappaB alternative splicing in the lung after burn injury.
Nuclear factor kappa-B (NF-kappaB), a key downstream player of the LPS signaling pathway, has been shown to undergo alternative splicing in in vitro studies. In this study, we examined the effect of injury and the role of CD14 on NF-kappaB alternative splicing using a murine burn model. CD14 knockout and respective wild-type mice were sacrificed after 18% total body surface area burn. RT-PCR and subsequent sequencing analysis revealed that injury induced multiple novel splicing variants of relA, relB, and NF-kappaB2 in the lungs of CD14 knockout but not wild-type mice. These novel variants resulted either from exon skipping, alternative usage of splicing signals, or intron retention. All but one variant resulted in a frameshift leading to premature termination of translation. These splicing variants encoded for proteins that lacked the domains essential for NF-kappaB transcription factor functions. Two NF-kappaB2 variants acquired only minor changes in their C-terminus that might affect their post-translational cleavage into active isoforms. These results suggest that alternative splicing may be one of the mechanisms by which NF-kappaB activity in the lungs can be regulated after injury. Furthermore, the CD14-mediated LPS signaling pathway may play a role in the regulation of NF-kappaB alternative splicing in the lungs after injury.
Department of Surgery, University of California at Davis and Burn Research, Shriners Hospitals for Children Northern California, Sacramento, CA 95817, USA.
Ho H
HH
Phan
Kiho
K
Cho
Kelly S
KS
Sainz-Lyon
Soowan
S
Shin
David G
DG
Greenhalgh
D017398:Alternative Splicing / Q000187:drug effects / Q000235:genetics; D000818:Animals; D001483:Base Sequence; D002056:Burns / Q000235:genetics / Q000378:metabolism*; D002460:Cell Line; D018389:Codon, Nonsense / Q000235:genetics / Q000378:metabolism; D005091:Exons / Q000235:genetics; D005260:Female; D006801:Humans; D007438:Introns / Q000235:genetics; D018950:Lipopolysaccharide Receptors / Q000235:genetics / Q000378:metabolism*; D008070:Lipopolysaccharides / Q000494:pharmacology; D008168:Lung / Q000378:metabolism*; D055370:Lung Injury; D051379:Mice; D018345:Mice, Knockout; D008969:Molecular Sequence Data; D016328:NF-kappa B / Q000096:biosynthesis* / Q000235:genetics; D020033:Protein Isoforms / Q000096:biosynthesis / Q000235:genetics; D011499:Protein Processing, Post-Translational / Q000187:drug effects / Q000235:genetics; D015398:Signal Transduction / Q000187:drug effects / Q000235:genetics / Q000276:immunology
D018389:Codon, Nonsense; D018950:Lipopolysaccharide Receptors; D008070:Lipopolysaccharides; D016328:NF-kappa B; D020033:Protein Isoforms