angiogenin and Endometriosis

How does hypoxia-mediated downregulation of chicken ovalbumin upstream promoter-transcription factor II (COUP-TFII) promote angiogenesis in endometriosis?. Suppression of COUP-TFII by hypoxia stimulates angiogenesis through induction of angiogenin (ANG).. The level of COUP-TFII is downregulated in endometriotic tissues, and downregulation of COUP-TFII contributes to the development of endometriosis.. Twenty-seven patients of reproductive age with endometriosis were recruited in this study. Eutopic endometrial and ectopic endometriotic stromal cells were isolated, cultured and subjected to various treatments.. Microarray hybridization, quantitative RT-PCR, and Western blot were used to detect gene expression in normal and endometriotic samples. A luciferase reporter assay and chromatin immunoprecipitation in normoxia- or hypoxia-treated primary cultures of human endometrial stromal cells were performed. Tube formation analysis was performed using primary human umbilical vein endothelial cells (HUVECs).. Protein level of COUP-TFII was downregulated by hypoxia (P < 0.05, normoxia versus hypoxia). Loss of COUP-TFII increased the angiogenic capacity of endometrial stromal cells (P < 0.05, COUP-TFII knockdown versus knockdown control). A novel COUP-TFII target gene, ANG, was identified through microarray analysis. Chromatin immunoprecipitation and promoter activity assays demonstrated that the ANG promoter was bound and suppressed by COUP-TFII (P < 0.05, COUP-TFII overexpression versus empty vector). The levels of ANG mRNA and protein were elevated in ectopic endometriotic stromal cells and negatively correlated with COUP-TFII (P < 0.05, endometrial versus endometriotic tissues/stromal cells). Both knockdown and forced-expression of COUP-TFII further demonstrated that ANG expression and ANG-mediated angiogenic activity were negatively regulated by COUP-TFII (P < 0.05, COUP-TFII knockdown versus knockdown control, and COUP-TFII overexpression versus empty vector).. This study was conducted in primary human endometrial stromal cell cultures and HUVECs, therefore, may not fully reflect the situation in vivo.. The raw data were submitted to Gene Expression Omnibus (GSE107469).. This is the first study to highlight that the aberrant expression of ANG in endometriotic lesions is mediated by hypoxia-suppressed COUP-TFII expression, which reveals an as yet unidentified molecular pathogenesis of endometriosis.. This work was supported by research grants (MOST 105-2314-B-006-059-MY3 to M.H.W. and MOST 104-2320-B-006-036-MY3 to S.J.T.) from the Ministry of Science and Technology, Taiwan. The authors declare that there is no conflict of interest.

Topics: Case-Control Studies; Cell Hypoxia; Cells, Cultured; Cellular Microenvironment; COUP Transcription Factor II; Endometriosis; Endometrium; Female; Human Umbilical Vein Endothelial Cells; Humans; Neovascularization, Pathologic; Paracrine Communication; Primary Cell Culture; Ribonuclease, Pancreatic; Signal Transduction; Stromal Cells

Endometriosis is a sex hormone-dependent and successively progressing gynecological disease, characterized by the presence of endometrial tissue outside the uterus. The etiology of endometriosis is known to be multifactorial, and its growth depends on immunological, hormonal, genetic and environmental factors. Angiogenesis plays a key role in implantation and growth of endometriotic lesions, as well as in adhesion formation. Physiologically angiogenesis is responsible for neoangiogenesis and recruitment of new capillaries from the already existing capillaries. It is well-documented that altered angiogenesis provokes improper follicular maturation, infertility recurrent miscarriages, ovarian hyperstimulation syndrome, and carcinogenesis. Factors stimulating angionesis include angiogenin, vascular endothelial growth factor (VEGF) and fibroblast growth factor (FGF).. The aim of the study was to analyze angiogenic factor concentration (angiogenin, VEGF, FGF) in blood serum and peritoneal fluid in patients with diagnosed endometriosis and idiopathic infertility.. A total of 39 patients were recruited for the study including 19 patients (study group) diagnosed with endometriosis during the laparoscopic procedure and 20 patients (control group) with idiopathic infertility and no morphologic changes within the pelvis revealed during the laparoscopic procedure. All patients underwent laparoscopy during the follicular phase of the menstrual cycle. Vein blood sample was obtained before the procedure and during laparoscopy the entire peritoneal fluid was aspirated for further measurement of VEGF, FGF and angiogenin concentrations.. Angiogenin concentration in peritoneal fluid was statistically higher in patient with idiopathic infertility in comparison to endometriosis (p<0.05). Higher angiogenin concentration was detected also in blood serum of patients with idiopathic infertility as compared to patients with endometriosis, but no statistical significance was found. VEGF and FGF concentration in blood serum and peritoneal fluid was similar in both groups (p>0.05). There were no significant differences between serum and peritoneal fluid in case of VEGF FGF and angiogenin in any of the groups.. Angiogenic factors concentration (VEGF FGF agiogenin) in the peritoneal fluid and blood serum during the follicular phase of the menstrual cycle is not a diagnostic criterion for endometriosis.

Topics: Adult; Ascitic Fluid; Endometriosis; Female; Fibroblast Growth Factors; Humans; Reference Values; Ribonuclease, Pancreatic; Vascular Endothelial Growth Factor A; Young Adult

Angiogenin, a potent inducer of angiogenesis, is expressed in human endometrium. This study was performed to compare the expression of angiogenin mRNA level in the eutopic endometrium from women with and without endometriosis. Thirty-two women with advanced stage endometriosis and 29 control women were recruited. Following isolation of total RNA from endometrial tissue and reverse transcription, cDNA samples were amplified by real time polymerase chain reaction to quantify the expression of angiogenin genes. In selected patients, immunohistochemical staining was utilized to localize the area of angiogenin expression. Angiogenin mRNA level was significantly lower in the endometriosis group than in the control group during the secretory phase, especially the mid-secretory phase, and the decline was observed mainly in the women who presented with infertility. Within the endometriosis group, angiogenin mRNA levels did not differ between the proliferative and secretory phases, but, in the control group, the level in the secretory phase was higher than that during the proliferative phase. Immunohistochemistry showed that the glandular epithelial cell layer was decorated positively in both groups. These findings suggest that the relative deficiency of angiogenin expression in the secretory endometrium could impair implantation in women with advanced stage endometriosis.

Topics: Adult; Endometriosis; Endometrium; Female; Fertility; Gene Expression Regulation; Humans; Immunohistochemistry; Menstrual Cycle; Models, Biological; Reverse Transcriptase Polymerase Chain Reaction; Ribonuclease, Pancreatic; RNA, Messenger

Many soluble factors contributing to the pathophysiology of endometriosis are found at abnormal levels in patients suffering from the disease. We postulated that levels of these factors could also be altered in the serum of patients. We compared levels of insulin-like growth factor-1 (IGF-1), soluble form of tumor necrosis factor-alpha (TNF-alpha) receptor-1 (sTNFR-1) and angiogenin in the serum of patients with endometriosis and controls.. Levels of IGF-1, sTNFR-1 and angiogenin were measured by enzyme-linked immunosorbent assay in samples from 148 patients (77 cases and 71 controls) with diagnostic confirmed by laparoscopy. Correlations with demographic data and stage of the disease were evaluated and potential confounders in the study population were controlled.. A significant increase in sTNFR-1 and angiogenin serum levels was observed in cases in comparison with controls, but only for patients in the follicular phase of the cycle. No significant difference was found in serum levels of IGF-1, sTNFR-1 and angiogenin between cases and controls in the luteal phase of the cycle. Correlations between levels of angiogenin and stage of the disease could also be observed.. sTNFR-1 and angiogenin represent potential blood markers for endometriosis.

Topics: Adult; Biomarkers; Carrier Proteins; Endometriosis; Enzyme-Linked Immunosorbent Assay; Female; Follicular Phase; Humans; Insulin-Like Growth Factor I; Luteal Phase; Middle Aged; Receptors, Tumor Necrosis Factor; Receptors, Tumor Necrosis Factor, Type I; Ribonuclease, Pancreatic; Tumor Necrosis Factor Decoy Receptors

To assess the release of angiogenin into peritoneal fluid in women with and without endometriosis by measuring its concentration with reference to disease stage, presence of red lesions, and phase of the menstrual cycle.. Retrospective study.. Nagoya City University Hospital.. Sixty-four women with endometriosis (n = 38) and cystadenomas (n = 26) for whom surgery was scheduled in the proliferative or secretory phase of the menstrual cycle.. Peritoneal fluid samples were obtained at laparotomy or laparoscopy.. Angiogenin concentrations in the peritoneal fluid, as measured by ELISA.. Angiogenin concentration in the peritoneal fluid was markedly elevated in the endometriosis patients (median 515 ng/mL, interquartile range 151-1763 ng/mL) compared with the cystadenoma (control) patients (195 ng/mL, 98-324 ng/mL), with values correlating with the extent of the disease. No significant differences between the proliferative phase and the secretory phase were observed in either the controls or the endometriosis patients.. The inflammation associated with endometriosis, through increasing levels of peritoneal fluid angiogenin, might promote angiogenesis for progression of the disease and correlate with the extent of the disorder.

Topics: Adult; Angiogenesis Inducing Agents; Ascitic Fluid; Cohort Studies; Endometriosis; Female; Humans; Laparoscopy; Laparotomy; Menstrual Cycle; Middle Aged; Osmolar Concentration; Retrospective Studies; Ribonuclease, Pancreatic; Severity of Illness Index