Subcellular localization of nuclear factor kappa B in term human fetal membranes and myometrium during labor

Objective: To investigate the subcellular localization of nuclear factor kappa B (NF-B) in term human fetal membranes and myometrium during labor. Methods: Fetal membranes and myometrial tissue were collected from term pregnant women undergoing cesarean delivery after labor (n=4) and before labor (n=4). An immunostaining was done with NF-B p65 antibody. The intensity and distribution of nuclear immunostaining of NF-B p65 subunit were evaluated visually using a semiquantitative analysis. Results: NF-B p65 was present in all tissues studied, and it was localized principally in the cytoplasm of cells of amnion and chorion. But, NF-B p65 was localized more abundant in the nucleus than in the cytoplasm in myometrial cells. In amnion, chorion and myometrium, the staining scores of nuclear NF-B did not show any difference between the after-labor group and before-labor group. Conclusion: In human term gestational tissues, subcellular localization of NF-B showed cytoplasmic predominance in amnion and chorion, and nuclear predominance in myometrium. But these subcellular localizations did not change during labor.