The effects of labour and of interleukin 1 beta upon the expression of nuclear factor kappa B related proteins in human amnion.
Human labour is associated with persistently increased nuclear factor kappa B (NF-kB) activity in amnion. In this study we have shown that this involves only the p65 and p50 NF-kB subunits and is associated with an increase in the expression of p65 (P < 0.05), and of the NF-kB binding proteins IkBa, IkBb-1 and IkBb-2 (P < 0.05). Interleukin-1b stimulation leads to rapid degradation and resynthesis of IkBa within 2 h, and a decrease in IkBb-1 without a return to full expression by 2 h, but has little effect upon IkBb-2. IkBb-2 was found in both the cytosolic and nuclear protein fractions. These findings demonstrate that persistently increased NF-kB activity in amnion occurs despite increased expression of the inhibitory IkBa protein and is not mediated by persistant I-kappa kinase activity or inhibition of IkBa synthesis. The increased expression and nuclear localization of IkBb-2 suggests that its function may be to protect NF-kB from inactivation by IkBa and to maintain NF-kB-mediated gene transcription.
Lee
Yooni
Y
Imperial College Parturition Research Group, Institute of Reproductive and Developmental Biology, Hammersmith Hospital Campus, DuCane Road, London W12 0NN.
Allport
Victoria
V
Sykes
Anna
A
Lindstrom
Tamsin
T
Slater
Donna
D
Bennett
Phillip
P
D000650:Amnion / Q000166:cytology / Q000378:metabolism*; D002458:Cell Fractionation; D002478:Cells, Cultured; D005260:Female; D005865:Gestational Age; D006801:Humans; D020672:I-kappa B Proteins / Q000378:metabolism; D007375:Interleukin-1 / Q000378:metabolism*; D007743:Labor, Obstetric / Q000502:physiology*; D000072000:NF-KappaB Inhibitor alpha; D016328:NF-kappa B / Q000037:antagonists & inhibitors / Q000378:metabolism*; D052002:NF-kappa B p50 Subunit; D011247:Pregnancy; D051996:Transcription Factor RelA
C083487:I kappa B beta protein; D020672:I-kappa B Proteins; D007375:Interleukin-1; D016328:NF-kappa B; D052002:NF-kappa B p50 Subunit; C000606204:NFKBIA protein, human; D051996:Transcription Factor RelA; D000072000:NF-KappaB Inhibitor alpha