Role of AP-1 family proteins in regulation of inducible nitric oxide synthase (iNOS) in human neutrophils.
The aim of the study was to assess the activity of AP-1 family proteins, e.g. Fra-1, Fra-2, JunB, JunD, and FosB, engaged in the regulation of inducible nitric oxide synthase (iNOS) expression and the production of NO by neutrophils (PMN) exposed to N-nitrosodimethylamine (NDMA) xenobiotic. Isolated human PMN were incubated in the presence of NDMA. iNOS mRNA expression was then analyzed using Northern blot and the expression of other proteins in the cytoplasmic and nuclear fractions were assessed using Western blot. The obtained results indicate that NDMA increased iNOS mRNA and protein expression in human PMN. Furthermore, it increased the expression of Fra-1, Fra-2, JunB, and JunD in the cytoplasmic fraction, and FosB expression in the fractions of analyzed cells. As a consequence of inhibiting p38 pathway and JNK, reduced iNOS expression and NO production was noted in PMN exposed to NDMA. Inhibition of the p38 pathway resulted in reduced expression of all analyzed proteins in the cytoplasmic fraction of PMN exposed to NDMA. Furthermore, increased Fra-2 expression and reduced FosB expression were found in the nuclear fraction of those cells. Inhibiting ERK5 pathway resulted in increased JunB expression in both fractions of the analyzed cells. Therefore, no changes in the expression of analyzed proteins in the presence of NDMA were observed in PMN pre-incubated with JNK pathway inhibitor. In conclusion, the results here indicate a role of Fra-1, Fra-2, JunB, JunD, and FosB transcription factors in the regulation of iNOS expression and NO production by human neutrophils exposed to NDMA.
Department of Immunology, Medical University of Bialystok, Waszyngtona 15A, 15-269 Bialystok, Poland. rwioletta@umb.edu.pl
Wioletta
W
Ratajczak-Wrona
Ewa
E
Jablonska
Marzena
M
Garley
Jakub
J
Jablonski
Piotr
P
Radziwon
Agnieszka
A
Iwaniuk
D002478:Cells, Cultured; D003593:Cytoplasm / Q000378:metabolism*; D004128:Dimethylnitrosamine / Q000494:pharmacology; D051921:Fos-Related Antigen-2 / Q000235:genetics / Q000378:metabolism; D015971:Gene Expression Regulation, Enzymologic; D006801:Humans; D020935:MAP Kinase Signaling System; D009504:Neutrophils / Q000276:immunology*; D052247:Nitric Oxide Synthase Type II / Q000235:genetics*; D021381:Protein Transport; D016760:Proto-Oncogene Proteins c-fos / Q000235:genetics / Q000378:metabolism; D016755:Proto-Oncogene Proteins c-jun / Q000235:genetics / Q000378:metabolism; D018808:Transcription Factor AP-1 / Q000235:genetics / Q000378:metabolism*; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism; D015854:Up-Regulation; D000099169:Fos-Related Antigen 1
D004128:Dimethylnitrosamine; D051921:Fos-Related Antigen-2; D052247:Nitric Oxide Synthase Type II; D016760:Proto-Oncogene Proteins c-fos; D016755:Proto-Oncogene Proteins c-jun; D018808:Transcription Factor AP-1; D014157:Transcription Factors; D000099169:Fos-Related Antigen 1; C064269:FOSB protein, human; C497872:FOSL2 protein, human; C581727:JunB protein, human; C559371:JunD protein, human; C496319:NOS2 protein, human