Differential expression of AP-1 proteins in human myometrium after spontaneous term labour onset.
OBJECTIVE
The aims of this study were (i) to determine the localisation of activator protein (AP)-1 family members (cFos, FosB, cJun, JunB and JunD) in human myometrium; and (ii) to determine the effect of human term labour on the expression of AP-1 family of transcription factors in myometrium.


METHODS
This localised the AP-1 family members cFos, FosB, cJun, JunB and JunD in human myometrium was performed by immunohistochemistry. The effect of term labour on the expression of these family members at the mRNA and protein level was assessed by qRT-PCR and Western blotting, respectively. The effect of pro-inflammatory stimuli on AP-1 transcriptional activity was assessed using a luciferase assay in primary human myometrial cells.


RESULTS
Immunohistochemical expression of cFos, FosB, cJun, JunB and JunD were all present in human myometrial tissue and displayed cytoplasmic staining. FosB and JunD also displayed nuclear staining. Term labour was associated with an increase in cFos and JunB mRNA and protein expression. On the other hand, JunD mRNA and protein expression was decreased with labour. FosB mRNA was increased with labour, but there was no change at the protein level. There was no change in cJun mRNA or protein expression. AP-1 transcriptional activity was increased in human myometrial cells by the pro-inflammatory cytokine TNF-α. There was, however, no effect of the bacterial products lipopolysaccharide (LPS; TLR4 ligand), iE-DAP (NOD1 ligand), MDP (NOD2 ligand), FSL-1 (TLR2 ligand) or flagellin (TLR5 ligand) on AP-1 transcriptional activity.


CONCLUSIONS
This study shows that human labour is associated with changes in AP-1 family members. Further studies are required to determine the exact role of the AP-1 family members in myometrium.
Mercy Perinatal Research Centre, Mercy Hospital for Women, Heidelberg, Victoria, Australia; Obstetrics, Nutrition and Endocrinology Group, Department of Obstetrics and Gynaecology, University of Melbourne, Victoria, Australia.
Ratana
R
Lim
Mercy Perinatal Research Centre, Mercy Hospital for Women, Heidelberg, Victoria, Australia; Obstetrics, Nutrition and Endocrinology Group, Department of Obstetrics and Gynaecology, University of Melbourne, Victoria, Australia. Electronic address: mlappas@unimelb.edu.au.
Martha
M
Lappas
D002467:Cell Nucleus / Q000737:chemistry; D002478:Cells, Cultured; D003593:Cytoplasm / Q000737:chemistry; D003960:Diaminopimelic Acid / Q000031:analogs & derivatives / Q000494:pharmacology; D004075:Diglycerides / Q000494:pharmacology; D005260:Female; D005408:Flagellin / Q000494:pharmacology; D006801:Humans; D007745:Labor Onset; D008070:Lipopolysaccharides / Q000494:pharmacology; D009215:Myometrium / Q000737:chemistry / Q000378:metabolism*; D009842:Oligopeptides / Q000494:pharmacology; D011247:Pregnancy; D016760:Proto-Oncogene Proteins c-fos / Q000032:analysis / Q000235:genetics / Q000378:metabolism; D016755:Proto-Oncogene Proteins c-jun / Q000032:analysis / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D047929:Term Birth; D018808:Transcription Factor AP-1 / Q000032:analysis / Q000235:genetics / Q000378:metabolism*; D014157:Transcription Factors / Q000032:analysis / Q000235:genetics / Q000378:metabolism; D014158:Transcription, Genetic / Q000187:drug effects; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology
D004075:Diglycerides; C064269:FOSB protein, human; C460864:FSL-1 lipoprotein, synthetic; C581727:JunB protein, human; C559371:JunD protein, human; D008070:Lipopolysaccharides; D009842:Oligopeptides; D016760:Proto-Oncogene Proteins c-fos; D016755:Proto-Oncogene Proteins c-jun; D012333:RNA, Messenger; D018808:Transcription Factor AP-1; D014157:Transcription Factors; D014409:Tumor Necrosis Factor-alpha; D005408:Flagellin; D003960:Diaminopimelic Acid; C034331:N(2)-(gamma-D-glutamyl)-meso-2,2'-diaminopimelic acid
AP-1; Human labour; Myometrium