Laminins 2 and 4 are expressed by human decidual cells.

During pregnancy, the resident stromal cells of the endometrium differentiate to become decidual cells and produce a pericellular basement membrane. We used immunofluorescence and Western blotting with a panel of monoclonal Ab specific for various laminin subunits to examine the composition of decidual laminin. The stromal cell basement membrane contained subunits alpha 2 (M), beta 1 (B1), beta 2 (S), and gamma 1 (B2). Low levels of alpha 1 could also be detected. The glandular and vascular basement membranes of decidual tissue contained subunits alpha 1 (A), beta 1, and gamma 1. An extract was produced from decidual extracellular matrix. Western blots of nonreducing gels showed the presence of high molecular weight complexes containing alpha 2, beta 1, beta 2, and gamma 1. These data indicated that laminins 2 and 4 are coexpressed by decidual cells. Laminin 1 was present in the extract as a minor component. In contrast, cultured stromal cells expressed laminin 1 as the major secreted variant. Immunolocalization was carried out using tissue from various stages of the nonpregnant cycle. The alpha 2 chain polypeptide was absent in the proliferative phase of the cycle but present in late secretory phase in perivascular areas where predecidual differentiation occurs. Reverse transcriptase-PCR experiments confirmed the presence of alpha 2 chain mRNA in decidua but showed that this transcript is detectable throughout the nonpregnant cycle. The results showed that laminins 2 and 4 are hormonally regulated products of decidual cells. The composition of the vascular and epithelial basement membranes remained constant throughout the cycle.

Comment: effect of cytokines on prolactin production by human decidual stromal cells in culture: studies using cells freed of bone marrow-derived contaminants.

Human decidua contains resident decidual cells alongside a population of bone marrow-derived cells, among which macrophages and large granular lymphocytes are most abundant. We hypothesized that soluble effectors produced by bone marrow-derived cells may modulate the function of the decidual cells. To investigate this, a cell purification protocol was devised that involved digestion of first-trimester decidua with collagenase and hyaluronidase to produce a mixed stromal cell suspension from which the bone marrow-derived cells were removed using immunomagnetic beads coated with anti-CD45. The resulting stromal cells were maintained in culture in the presence of progesterone and were found to produce PRL. The effect of a panel of cytokines on PRL production was examined. Tumor necrosis factors-alpha and -beta had a dose-dependent inhibitory effect, and tumor necrosis factor receptors were identified on the cells. Interleukin 1 alpha and 1 beta, platelet-derived growth factor, and transforming growth factor-beta 1 were also found to inhibit PRL production, and platelet-derived growth factor and transforming growth factor-beta 1 stimulated cell proliferation. These findings suggest an interaction between the immune and endocrine systems in regulating the maternal environment of early pregnancy.