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Background: Leukemia inhibitory factor (LIF) is a pleiotropic cytokine that is essential for blastocyst implantation in mice. It has been suggested that LIF may play a role in human first trimester extravillous trophoblast (EVT) invasion. The aim of the present study was to establish whether LIF induces changes in EVT function related to invasiveness.Methods: Primary first trimester human EVT cell cultures were treated with/without LIF and the effects on cell adhesion to fibronectin (FN), vitronectin (VN) and laminin (LN) were assessed. Transcript levels of integrin subunits that mediate cell adhesion to these extracellular matrix (ECM) elements were determined by real-time RT-PCR. Matrix metalloproteinase (MMP)2 and MMP9 secretion was assessed by gelatine zymography and tissue inhibitors matrix metalloproteinase (TIMP) -1 and TIMP-2 secretion by enzyme-linked immunosorbent assay.Results: EVT cells showed increased adhesion to FN, VN and LN ECM elements in response to LIF (20, 20 and 29%, respectively, P < 0.05 FN and VN compared to control; and P < 0.001 LN compared to control). Integrin beta(4) mRNA levels decreased by 50% following LIF treatment (P < 0.001 versus control). MMP2 and MMP9 secretion was not affected by LIF but LIF did increase secretion of TIMP-1 and -2 (P < 0.001 versus control). LIF stimulated the phosphorylation of signal transducer and activator of transcription (STAT) 3 protein while it did not affect STAT3 protein abundance. The addition of a LIF inhibitor attenuated the LIF-induced STAT3 phosphorylation in EVT.Conclusion: The results suggest that LIF can regulate EVT invasion, suggesting an important role in early placental development. [ABSTRACT FROM AUTHOR]

Background: Successful blastocyst implantation requires the differentiation of human endometrial stromal cells (HESC), a process known as decidualization. Activin A, a transforming growth factor beta (TGFbeta) superfamily member, enhances HESC decidualization and localizes to decidual cells in human endometrium. Other TGFbeta superfamily members, including BMP2, BMP4, BMP7, GDF5, GDF8, GDF11, TGFbetas and Nodal, may also play a role during decidualization. This study aimed to identify these TGFbeta family members in human endometrium, and to determine whether they are involved in human decidualization.Methods: Protein localization of TGFbeta family members was examined in secretory phase human endometrium and first trimester decidua by immunohistochemistry. mRNA expression was examined in HESC. Activin inhibitors (Activin-M108A/SB431542) with differing specificities for the other TGFbeta members under consideration were applied during HESC decidualization in vitro. The secretion levels of potential TGFbeta superfamily members were measured during decidualization, and recombinant proteins added to examine their effect.Results: This study has identified BMP2, BMP4, BMP7, GDF5, GDF8 and GDF11 but not Nodal in secretory phase human endometrium, but only BMP2, GDF5 and TGFbeta1 protein were detected in decidual cells. All ligands except Nodal were expressed by cultured HESC. Both inhibitors significantly reduced decidualization validating the role of activin, but potentially also other TGFbeta members, during decidualization. BMP2 and TGFbeta1 secretion increased during HESC decidualisation and exogenous administration of these proteins significantly enhanced decidualization in vitro.Conclusions: Like activin, BMP2 and TGFbeta1 are likely to be involved in HESC decidualization. This is the first study to identify and localize BMP4, BMP7, GDF5, GDF8 and GDF11 in secretory phase human endometrium. Understanding the factors critical for the implantation process is needed for improving fertility and pregnancy outcomes. [ABSTRACT FROM AUTHOR]

BACKGROUND: Breakthrough bleeding (BTB) is the most common reason for discontinuation of progestin-only (p-only) contraceptives, yet the causes are unknown. Use of p-only contraceptives is associated with elevated influx of endometrial leukocytes, similar to that observed perimenstrually or within decidualized endometrium. We hypothesized that chemokine expression is altered in women using p-only contraceptives, leading to abnormal leukocyte recruitment and BTB. METHODS: Expression of eight highly abundant endometrial chemokines was examined using immunohistochemistry and real-time PCR, in endometria from women using subdermal and intrauterine levonorgestrel and correlated to leukocyte subpopulations. RESULTS: Macrophage-derived chemokine (MDC), hemofiltrate CC chemokine-1 (HCC-1), monocyte chemoattractant protein-3 (MCP-3), interleukin-8 (IL-8) and eotaxin were strongly produced by epithelial glands, comparable to levels in premenstrual phase endometrium. Stromal cells were negative for chemokines in atrophic/shedding endometria, but intensely positive in highly decidualized tissues for MDC, MCP-3, HCC-1 and 6Ckine. Macrophage inflammatory protein-1β (MIP-1b) and HCC-4 were suppressed in all p-exposed endometria. CONCLUSIONS: These data demonstrate that chemokine expression is dysregulated in p-exposed endometria, consistent with the morphological appearance of the endometrium and the leukocyte subsets present. This reinforces a potential role for chemokines in the elevated leukocyte recruitment that contributes to endometrial fragility and BTB. [ABSTRACT FROM AUTHOR]