Integrins are heterodimeric glycoproteins that have been found to undergo dynamic temporal and spatial changes in the endometrium during the menstrual cycle and in early pregnancy. Specificity of integrins is known to be different in human endometrial stromal cells and decidual cells. These shifts of integrins suggested to play an important role in embryo implantation and can be modulated by progesterone, cAMP derivatives, and cytokines. The mechanisms of decidualization and its precise physiological role are still not clearly understood and in vitro systems could provide an alternative that overcomes limitations of studying such complex biological phenomena in vivo at the time of implantation. This study was undertaken to establish an in vitro model system for human decidualization using 8-bromo-cAMP and to investigate the characteristics of stromal integrin expression in vitro by 8-Br-cAMP. Endometrial stromal cells were isolated and cultured, and then were induced to decidualize by 0.5 mM 8-Br-cAMP for 15 days. Immunofluorescence staining and flow cytometric analyses of the integrin subunits (alpha1, alpha4, alpha5, alpha6, beta1 and alpha v beta3) were performed at day 9. In the presence of 8-Br-cAMP, the staining intensity of alpha v beta3 was significantly higher than control and measurements for alpha1, alpha4, alpha5, alpha6, and beta1 were similar. Immunofluorescent localization of the integrins reflected the differences obtained from the flow cytometric analyses described above. In summary, the expression of alpha;avbeta;b3 integrin increased in stromal cells in vitro decidualized by 8-Br-cAMP and this up-regulation of alpha v beta3 integrin expression during decidualization might influence on human implantation.
8-Bromo Cyclic Adenosine Monophosphate/*pharmacology ; Cell Size ; Cells, Cultured ; Decidua/*cytology/drug effects/metabolism ; Female ; Flow Cytometry ; Human ; Integrins/*analysis/metabolism ; Prolactin/analysis ; Stromal Cells/cytology/*drug effects/*metabolism

OBJECTIVETo study the effect of exogenous cytokine-stimulated decidual cells on IgG secretion of B lymphocytes and investigate the features of local immunological microenvironment of the decidua.

METHODSExogenous cytokines interferon-gamma (IFN-gamma), interleukin-2 (IL-2), IL-6 and epidermal growth factor (EGF) were added separately in cultured decidual cells, and the supernatant of the culture medium was prepared for stimulating human peripheral blood lymphocytes. IgG secretion of the B cells was measured by radio-immunological method.

RESULTThe decidual cells of normal early pregnancy stimulated B lymphocyte IgG secretion, and the supernatant of exogenous cytokine-stimulated decidual cells had the same effect, which, however, was depended not on the concentration and category of the cytokines, but only on the time of treatment.

CONCLUSIONThe exogenous cytokines can increase the humoral immunity in the decidual immunological microenvironment, but such effect might result from a self-regulatory mechanism of the local immunological microenvironment of the decidua, which can be fundamental for maintenance of normal pregnancy.

Adult ; B-Lymphocytes ; cytology ; drug effects ; metabolism ; Cells, Cultured ; Culture Media, Conditioned ; pharmacology ; Cytokines ; pharmacology ; Decidua ; cytology ; drug effects ; metabolism ; Female ; Humans ; Immunoglobulin G ; biosynthesis ; Interferon-gamma ; pharmacology ; Interleukin-2 ; pharmacology ; Pregnancy ; Pregnancy Trimester, First