A genomic and proteomic analysis of activation of the human neutrophil by lipopolysaccharide and its mediation by p38 mitogen-activated protein kinase.
Bacterial lipopolysaccharide (LPS) evokes several functional responses in the neutrophil that contribute to innate immunity. Although certain responses, such as adhesion and synthesis of tumor necrosis factor-alpha, are inhibited by pretreatment with an inhibitor of p38 mitogen-activated protein kinase, others, such as actin assembly, are unaffected. The aim of the present study was to investigate the changes in neutrophil gene transcription and protein expression following lipopolysaccharide exposure and to establish their dependence on p38 signaling. Microarray analysis indicated expression of 13% of the 7070 Affymetrix gene set in nonstimulated neutrophils, and LPS up-regulation of 100 distinct genes, including cytokines and chemokines, signaling molecules, and regulators of transcription. Proteomic analysis yielded a separate list of up-regulated modulators of inflammation, signaling molecules, and cytoskeletal proteins. Poor concordance between mRNA transcript and protein expression changes was noted. Pretreatment with the p38 inhibitor SB203580 attenuated 23% of LPS-regulated genes and 18% of LPS-regulated proteins by > or = 40%. This study indicates that p38 plays a selective role in regulation of neutrophil transcripts and proteins following lipopolysaccharide exposure, clarifies that several of the effects of lipopolysaccharide are post-transcriptional and post-translational, and identifies several proteins not previously reported to be involved in the innate immune response.
Fessler
Michael B
MB
Department of Medicine, Division of Pulmonary Sciences and Critical Care Medicine, University of Colorado Health Sciences Center and National Jewish Medical and Research Center, Denver, Colorado 80262, USA.
Malcolm
Kenneth C
KC
Duncan
Mark William
MW
Worthen
G Scott
GS
D000595:Amino Acid Sequence; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000494:pharmacology; D015180:Electrophoresis, Gel, Two-Dimensional; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects*; D006801:Humans; D007093:Imidazoles / Q000494:pharmacology; D008070:Lipopolysaccharides / Q000494:pharmacology*; D020928:Mitogen-Activated Protein Kinases / Q000097:blood / Q000235:genetics* / Q000302:isolation & purification; D009504:Neutrophils / Q000187:drug effects / Q000502:physiology*; D020411:Oligonucleotide Array Sequence Analysis; D020543:Proteome; D011725:Pyridines / Q000494:pharmacology; D012333:RNA, Messenger / Q000235:genetics; D011994:Recombinant Proteins / Q000097:blood / Q000302:isolation & purification; D020133:Reverse Transcriptase Polymerase Chain Reaction; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D014158:Transcription, Genetic; D048051:p38 Mitogen-Activated Protein Kinases
D000894:Anti-Inflammatory Agents, Non-Steroidal; D007093:Imidazoles; D008070:Lipopolysaccharides; D020543:Proteome; D011725:Pyridines; D012333:RNA, Messenger; D011994:Recombinant Proteins; D020928:Mitogen-Activated Protein Kinases; D048051:p38 Mitogen-Activated Protein Kinases; C093642:SB 203580