Heme oxygenase-1 gene activation by the NAD(P)H oxidase inhibitor 4-(2-aminoethyl) benzenesulfonyl fluoride via a protein kinase B, p38-dependent signaling pathway in monocytes.
Heme oxygenase (HO)-1 is the inducible isoform of the rate-limiting enzyme of heme degradation and modulates the inflammatory immune response. Because HO-1 is up-regulated by NAD(P)H oxidase activators such as lipopolysaccharide and 12-O-tetradecanoylphorbol-13-acetate in monocytic cells, we investigated the gene regulation of HO-1 by the chemical NAD(P)H oxidase inhibitor 4-(2-aminoethyl) benzenesulfonyl fluoride (AEBSF). Unexpectedly, AEBSF induced endogenous gene expression and promoter activity of HO-1 in cell cultures of human and mouse monocytes. Inhibition of the phosphatidylinositol 3-kinase/protein kinase B (PKB) pathway by pharmacological inhibitors and cotransfection of an expression vector for a dominant negative mutant of PKB reduced the AEBSF-dependent induction of HO-1 gene transcription. Accordingly, overexpressed constitutively active PKB markedly up-regulated HO-1 promoter activity. AEBSF activated the mitogen-activated protein kinases (MAPK) JNK and p38. Inhibition of p38alpha and p38beta, but not that of JNK or p38gamma and p38delta, prevented the induction of HO-1 gene expression by AEBSF. p38 was stimulated by AEBSF in a PKB-dependent manner as demonstrated by a luciferase assay with a Gal4-CHOP fusion protein. Finally, AEBSF- and PKB-dependent induction of HO-1 promoter activity was reduced by simultaneous mutation of an E-box motif (-47/-42) and a cAMP response element/AP-1 element (-664/-657) of the proximal HO-1 gene promoter. Overexpression of the basic helix-loop-helix transcription factor USF2 and coactivator p300 enhanced the AEBSF-dependent response of the HO-1 promoter. The data suggest that the transcriptional induction of HO-1 gene expression by AEBSF is mediated via activation of a PKB, p38 MAPK signaling pathway.
Wijayanti
Nastiti
N
Institut für Klinische Immunologie und Transfusionsmedizin, Justus-Liebig-Universität Giessen, Langhanstrasse 7, D-35392 Giessen, Germany.
Kietzmann
Thomas
T
Immenschuh
Stephan
S
D020816:Amino Acid Motifs; D000818:Animals; D015153:Blotting, Western; D002460:Cell Line; D002478:Cells, Cultured; D004789:Enzyme Activation; D004791:Enzyme Inhibitors / Q000494:pharmacology; D015971:Gene Expression Regulation, Enzymologic; D005799:Genes, Dominant; D006419:Heme Oxygenase (Decyclizing) / Q000096:biosynthesis* / Q000235:genetics*; D051547:Heme Oxygenase-1; D006801:Humans; D007107:Immune System; D007249:Inflammation; D007963:Leukocytes, Mononuclear / Q000378:metabolism; D008156:Luciferases / Q000378:metabolism; D008565:Membrane Proteins; D051379:Mice; D008954:Models, Biological; D009154:Mutation; D019255:NADPH Oxidases / Q000037:antagonists & inhibitors*; D010957:Plasmids / Q000378:metabolism; D011401:Promoter Regions, Genetic; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism; D011518:Proto-Oncogene Proteins / Q000378:metabolism; D051057:Proto-Oncogene Proteins c-akt; D051381:Rats; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D015842:Serine Proteinase Inhibitors / Q000494:pharmacology; D015398:Signal Transduction; D013450:Sulfones / Q000494:pharmacology; D013997:Time Factors; D018808:Transcription Factor AP-1 / Q000378:metabolism; D014158:Transcription, Genetic; D015533:Transcriptional Activation; D014162:Transfection; D015854:Up-Regulation; D048051:p38 Mitogen-Activated Protein Kinases / Q000378:metabolism
D004791:Enzyme Inhibitors; D008565:Membrane Proteins; D011518:Proto-Oncogene Proteins; D011993:Recombinant Fusion Proteins; D015842:Serine Proteinase Inhibitors; D013450:Sulfones; D018808:Transcription Factor AP-1; C002010:4-(2-aminoethyl)benzenesulfonylfluoride; D008156:Luciferases; C496541:HMOX1 protein, human; D006419:Heme Oxygenase (Decyclizing); D051547:Heme Oxygenase-1; C496542:Hmox1 protein, mouse; D019255:NADPH Oxidases; D017346:Protein Serine-Threonine Kinases; D051057:Proto-Oncogene Proteins c-akt; D048051:p38 Mitogen-Activated Protein Kinases