Mi-Ju Park

Integrin αVβ3 and αVβ5 are required for leukemia inhibitory factor-mediated the adhesion of trophoblast cells to the endometrial cells.

The embryo implantation including adhesion between trophoblast and endometrium is a crucial process for the successful pregnancy. LIF and adhesion molecules including integrins are known as significant factors for embryo implantation. However, the function of LIF on the regulation of adhesion molecule expression and promotion of trophoblast adhesion to endometrial cells has not been fully elucidated. Here we show that LIF significantly induced mRNA expression of ITGAV, ITGB3, and ITGB5 in endometrial cells, as evidenced by RT-PCR and qRT-PCR analysis. Based on the results from treatment of antagonist for LIF receptor (hLA), LIF positively regulates expression of integrin αV, β3, and β5, and adhesion of the human trophectoderm-derived JAr cells to endometrial Ishikawa cells. Furthermore, the adhesion between trophoblastic cells and LIF-stimulated endometrial cells was significantly reduced by neutralization of LIF-mediated integrin β3 and β5 expression on endometrial cell surface with integrin subunit β3 and β5 antibodies. Taken together, we firstly demonstrate that LIF enhances the adhesion of trophoblastic cells to endometrial cells by up-regulating expression of integrin heterodimer αVβ3 and αVβ5, indicating the promotion of endometrial receptivity for embryo implantation.

The inhibitory effects of Geranium thunbergii on interferon-γ- and LPS-induced inflammatory responses are mediated by Nrf2 activation

Geranium thunbergii Sieb. et Zucc. (GT; which belongs to the Geraniaceae family) has been used as a traditional medicine in East Asia for the treatment of inflammatory diseases, including arthritis and diarrhea. However, the underlying mechanisms of the anti-inflammatory effects of GT remain poorly understood. In the present study, we examined the mechanisms responsible for the anti-inflammatory activity of GT in macrophages. The results revealed that GT significantly inhibited the lipopolysaccharide (LPS)- and interferon-γ (IFN-γ)-induced expression of pro-inflammatory genes, such as inducible nitric oxide synthase, tumor necrosis factor-α and interleukin-1β, as shown by RT-PCR. However, the inhibitory effects of GT on LPS- and IFN-γ-induced inflammation were associated with an enhanced nuclear factor erythroid 2-related factor 2 (Nrf2) activity, but not with the suppression of nuclear factor (NF)-κB activity, as shown by western blot analysis. In addition, in bone marrow-derived macrophages (BMDM) isolated from Nrf2 knockout mice, GT did not exert any inhibitory effect on the LPS- and IFN-γ-induced inflammation. Taken together, our findings indicate that the anti-inflammatory effects of GT may be associated with the activation of Nrf2, an anti-inflammatory transcription factor.

Paeonia lactiflora Enhances the Adhesion of Trophoblast to the Endometrium via Induction of Leukemia Inhibitory Factor Expression

In the present study, we investigated the role of Paeonia lactiflora Pall. extract on embryo implantation in vitro and in vivo. A polysaccharides depleted-water extract of P. lactiflora (PL-PP) increased LIF expression in human endometrial Ishikawa cells at non-cytotoxic doses. PL-PP significantly increased the adhesion of the human trophectoderm-derived JAr spheroids to endometrial Ishikawa cells. PL-PP-induced LIF expression was decreased in the presence of a p38 kinase inhibitor SB203580 and an MEK/ERK inhibitor U0126. Furthermore, endometrial LIF knockdown by shRNA reduced the expression of integrins β3 and β5 and adhesion of JAr spheroids to Ishikawa cells. In vivo administration of PL-PP restored the implantation of mouse blastocysts in a mifepristone-induced implantation failure mice model. Our results demonstrate that PL-PP increases LIF expression via the p38 and MEK/ERK pathways and favors trophoblast adhesion to endometrial cells.

The function of cancer-shed gangliosides in macrophage phenotype: involvement with angiogenesis

Tumor-derived gangliosides in the tumor microenvironment are involved in the malignant progression of cancer. However, the molecular mechanisms underlying the effects of gangliosides shed from tumors on macrophage phenotype remain unknown. Here, we showed that ganglioside GM1 highly induced the activity and expression of arginase-1 (Arg-1), a major M2 macrophage marker, compared to various gangliosides in bone marrow-derived macrophages (BMDM), peritoneal macrophages and Raw264.7 macrophage cells. We found that GM1 bound to macrophage mannose receptor (MMR/CD206) and common gamma chain (γc). In addition, GM1 increased Arg-1 expression through CD206 and γc-mediated activation of Janus kinase 3 (JAK3) and signal transducer and activator of transcription- 6 (STAT-6). Interestingly, GM1-stimulated macrophages secreted monocyte chemoattractant protein-1 (MCP-1/CCL2) through a CD206/γc/STAT6-mediated signaling pathway and induced angiogenesis. Moreover, the angiogenic effect of GM1-treated macrophages was diminished by RS102895, an MCP-1 receptor (CCR2) antagonist. From these results we suggest that tumor-shed ganglioside is a secretory factor regulating the phenotype of macrophages and consequently enhancing angiogenesis.

Water-extracted tubers of Cyperus rotundus L. enhance endometrial receptivity through leukemia inhibitory factor-mediated expression of integrin αVβ3 and αVβ5

ETHNOPHARMACOLOGICAL RELEVANCE Cyperus rotundus L. (CR) has been traditionally used as an herbal medicine in Asian countries to treat diverse gynecological disorders. However, the potential therapeutic effect of CR on endometrial receptivity for successful embryo implantation to treat female infertility has not been fully studied. AIM OF STUDY The aim of this study was to evaluate the effect of water-extracted CR on endometrial receptivity by investigating the expression of leukemia inhibitory factor (LIF) and integrins, cell adhesion, and embryo implantation using mifepristone (RU486; RU)-induced implantation failure model. MATERIALS AND METHODS The water extract of CR was prepared and fingerprinted using high-performance liquid chromatography (HPLC). For the expression and regulation of LIF, reverse transcription polymerase chain reaction (RT-PCR) and western blotting were performed in CR-stimulated Ishikawa cells. To evaluate LIF-mediated integrin expression, knockdown of LIF by shRNA was performed in Ishikawa cells. The effect of CR on endometrial receptivity was determined by an in vitro adhesion assay between JAr cells and CR-induced Ishikawa cells. In vivo, C57BL/6 female mice (n = 7 per group) orally received CR (31.68mg/kg/day), a similar dose as used clinically. Seven days after CR treatment, all female mice were caged with male mice until pregnancy was verified. On day 4 of pregnancy, RU (4mg/kg) was injected subcutaneously to induce embryo implantation failure. RESULT CR increased the expression of LIF through the phosphatidylinositol-3-kinase/ protein kinase B (PI-3K/AKT) signaling pathway in Ishikawa cells. In addition, CR enhanced adhesion of JAr cells onto Ishikawa cells by inducing the expression of LIF-dependent integrins αVβ3 and αVβ5. Furthermore, CR improved the number of implantation sites in pregnant mice despite RU injection. CONCLUSION CR increased the expression of LIF-mediated integrins αVβ3 and αVβ5 on the surface of endometrial cells, which is associated with adhesion of trophoblastic cells to endometrial cells for blastocyst implantation. Our findings provide evidence that CR has therapeutic potential against poor endometrial receptivity.

Transforming growth factor β1 enhances adhesion of endometrial cells to mesothelium by regulating integrin expression

Endometriosis is the abnormal growth of endometrial cells outside the uterus, causing pelvic pain and infertility. Furthermore, adhesion of endometrial tissue fragments to pelvic mesothelium is required for the initial step of endometriosis formation outside uterus. TGF-β1 and adhesion molecules importantly function for adhesion of endometrial tissue fragments to mesothelium outside uterus. However, the function of TGF-β1 on the regulation of adhesion molecule expression for adhesion of endometrial tissue fragments to mesothelium has not been fully elucidated. Interestingly, transforming growth factor β1 (TGF-β1) expression was higher in endome-triotic epithelial cells than in normal endometrial cells. The adhesion efficiency of endometriotic epithelial cells to meso-thelial cells was also higher than that of normal endometrial cells. Moreover, TGF-β1 directly induced the adhesion of endometrial cells to mesothelial cells through the regulation of integrin of αV, α6, β1, and β4 via the activation of the TGF-β1/TGF-βRI/Smad2 signaling pathway. Conversely, the adhesion of TGF-β1-stimulated endometrial cells to mesothelial cells was clearly reduced following treatment with neutralizing antibodies against specific TGF-β1-mediated integrins αV, β1, and β4 on the endometrial cell membrane. Taken together, these results suggest that TGF-β1 may act to promote the initiation of endometriosis by enhancing integrin-mediated cell-cell adhesion.

Benzoic Acid Enhances Embryo Implantation through LIF-Dependent Expression of Integrin V3 and V5

Embryo implantation is the crucial step for a successful pregnancy. Diverse factors, including adhesion molecules, growth factors, and cytokines are important for embryo implantation through improving endometrial receptivity. Benzoic acid (BA), a component of various plants, has been shown to have antifungal and antioxidant effects. However, the effect of BA on embryo implantation remains unknown. Here, we showed the contribution of BA for the enhancement of endometrial receptivity through the leukemia inhibitory factor (LIF)-dependent increase of integrin αV, β3, and β5 expression. Furthermore, in vivo study using a mifepristone-induced implantation failure model showed that BA definitely improves the numbers of implantation embryos. Taken together, we suggest that BA has a novel function for embryo implantation through the up-regulation of LIF-mediated integrins, and may be a candidate for therapeutic medicine to increase the pregnancy rate.