Effects of the hypoxia-inducible factor-1 inhibitor echinomycin on vascular endothelial growth factor production and apoptosis in human ectopic endometriotic stromal cells.

Recent evidence points to a possible role for hypoxia-inducible factor (HIF)-1 in the pathogenesis and development of endometriosis. The objectives of this study were to investigate the critical role of HIF-1 in endometriosis and the effect of the HIF-1 inhibitor echinomycin on human ectopic endometriotic stromal cells (eESCs). Ectopic endometriotic tissues were obtained from 20 patients, who received an operation for ovarian endometriomas. We examined vascular endothelial growth factor (VEGF) and stromal cell-derived factor-1 (SDF-1) production, HIF-1 expression, cell proliferation and apoptosis of eESCs. Cobalt chloride (CoCl2) significantly induced expression of HIF-1α protein and VEGF production in a time-dependent manner in eESCs, but reduced SDF-1 production. VEGF production was significantly suppressed by treatment of 100 nM echinomycin without causing cell toxicity, but 0.1-10 nM echinomycin or 100 nM progestin had no significant effect. SDF-1 production was not affected by echinomycin treatment at any dose. Echinomycin inhibited cell proliferation and induced apoptotic cell death of the eESCs, and significantly inhibited expression of the anti-apoptotic proteins Bcl-2 and Bcl-xL. Echinomycin inhibits VEGF production and induces apoptosis of eESCs by suppression of Bcl-2 and Bcl-xL. These findings suggest the unique therapeutic potential for echinomycin as an inhibitor of HIF-1 activation for endometriosis treatment.

Regulation of decidualization and angiogenesis in the human endometrium: mini review.

AIM: The human endometrium is a dynamic tissue that undergoes regular cycles of menstruation, menstrual repair, proliferation and secretory differentiation in response to hypoxia and the female sex hormones. METHODS: We identified new target genes that are regulated by progesterone during the decidualization of human endometrial stromal cells (ESC), including interleukin-15 (IL-15), fibulin-1 (FBLN-1), and heart and neural crest derivatives expressed transcript 2 (HAND2). RESULTS: IL-15 is deeply involved in the hormonal control of the human endometrium by progesterone and may be important in embryo implantation. FBLN-1 has been shown to be an important extracellular matrix that mediates progesterone action in human ESC differentiation toward implantation. Moreover, progestin-induced HAND2 is a transcription factor that contributes to the increased levels of FBLN-1 in human ESC. Several mediators, including vascular endothelial growth factor (VEGF), angiopoietin (ANGPT) and stromal cell-derived factor 1 (SDF-1), regulate human endometrial angiogenesis. Hypoxia increased the expression of VEGF and decreased the expression of SDF-1 in ESCs. Furthermore, hypoxia reduced ANGPT1 levels in ESC; however, ANGPT2 levels were unaffected. Estradiol simultaneously induced the expressions of VEGF and SDF-1, suppressing ANGPT1 production. Therefore, hypoxia and estradiol caused an increase in the ANGPT2/ANGPT1 ratio. CONCLUSION: Hypoxia and female sex hormones are involved in the regulation of angiogenic factors in an independent manner in human ESC. Analysis of the process of decidualization and angiogenesis in the human endometrium would provide useful information for the fields of reproductive biology, regenerative medicine and tissue engineering.

Requirement of heart and neural crest derivatives-expressed transcript 2 during decidualization of human endometrial stromal cells in vitro.

OBJECTIVE: To investigate the role of heart and neural crest derivatives-expressed transcript 2 (HAND2) during decidualization of human endometrial stromal cells (ESCs). DESIGN: In vitro experiment. SETTING: Research laboratory. PATIENT(S): Twenty-six patients undergoing hysterectomy for benign reasons. INTERVENTION(S): ESCs were cultured for 12 days with HAND2 small interfering RNA (siRNA) or nonsilencing RNA during decidualization by medroxyprogesterone acetate (MPA) and E2. MAIN OUTCOME MEASURE(S): Decidualization was monitored by changes in cellular morphology and the expression of several decidual-specific genes. RESULT(S): HAND2 siRNA effectively suppressed HAND2 levels in ESCs after 12 days of E2 + MPA treatment. ESCs cultured with HAND2 siRNA retained a long fibroblast-like shape, whereas the cells cultured with control siRNA transformed into enlarged polygonal cells. Silencing of HAND2 expression significantly reduced connexin-43 involved in the morphologic changes. HAND2 silencing significantly reduced the mRNA levels of fibulin-1, prolactin, tissue inhibitor of metalloproteinase 3, interleukin-15, and forkhead box O1A (FOXO1A), but had no effect on the mRNA levels of dickkopf-1, serum glucocorticoid kinase 1, and insulin-like growth factor-binding protein 5. HAND2 siRNA effectively suppressed the levels of nuclear FOXO1A protein as a regulator of decidualization. CONCLUSION(S): These results suggest that HAND2 plays a key role in the regulation of progestin-induced decidualization of human ESCs.