Robust vascular development occurs during implantation and early placentation of normal pregnancies. Studies to define the extent and mechanisms by which defects in vascularity contribute to human implantation failure and early miscarriage need to be undertaken.
Placental growth factor (PGF, previously known as PlGF) is prominently expressed by trophoblasts in human placenta, whereas most nontrophoblast cells express low levels of PGF mRNA under normal physiological conditions. We have shown that hypoxia decreases PGF expression in the trophoblast, but little is known about transcriptional regulation of PGF gene expression. We sought to determine promoter regions of the human PGF gene that contribute to its restricted high constitutive expression in the trophoblast. Overlapping putative promoter regions of human PGF gene encompassing 2-1.5 kb were cloned into reporter vectors and co-transfected into trophoblast and nontrophoblast cell lines. Promoter activity generated by a 2-1.5-kb clone was significantly higher in trophoblasts than in nontrophoblasts. Selective deletion mutants showed that a clone encompassing the PGF (2-828/++34) region generated promoter activity similar to the 2-1.5-kb region in the trophoblast. However, deletion of another 131 bp from this subclone (2-698/++34) resulted in significantly less promoter activity in the trophoblast. The (2-828/2-698) region significantly enhanced activity of a minimal promoter construct in trophoblast but not in nontrophoblast cells, suggesting that this region contributes to regulating PGF transcription in the trophoblast. Site-directed mutagenesis of a glial cell missing 1 (GCM1) motif in the 131-bp region significantly decreased enhancer activity in the trophoblast. Furthermore, overexpression of GCM1 significantly increased PGF 2-1.5-kb promoter activity and PGF mRNA expression in trophoblast and nontrophoblast cells. Forced overexpression of GCM1 restored PGF expression in the hypoxic trophoblast. These data support a functional role for GCM1 contributing to constitutively high trophoblast PGF expression and is the first direct evidence of an oxygen-responsive, trophoblast-specific transcription factor contributing to the regulation of PGF expression.
Objective-To determine the mechanism for differential effects of low oxygen tension on human PlGF gene transcription in trophoblast and nontrophoblast cells.Study Design-Human PlGF reporter clones and real time RT-PCR were used to compare the effects of hypoxia on gene transcription in human trophoblast and nontrophoblast cell lines. Overexpression of HIF-1α, inhibition of HIF-1 function and biochemical assessments of HIF-1 cofactor interactions were used to characterize hypoxia response mechanisms regulating PlGF transcription.Results-PlGF transcription is specifically inhibited by low oxygen tension in trophoblast but is induced in some nontrophoblast cells. Overexpression of HIF-1α in normoxic cells or inhibition of HIF-1 function in hypoxic cells did not significantly alter transcription patterns of the PlGF gene in either cell type.Conclusions-These results suggest that transcriptional repression of PlGF gene expression occurs in human trophoblast exposed to low oxygen tension but that PlGF transcription is stimulated in certain hypoxic nontrophoblast cells. However, regulation of PlGF transcription is not mediated by functional HIF-1 activity in either cell types.
Abnormal accumulation of acyl-CoA cholesterol acyltransferase-1 (ACAT-1) mediated cholesterol ester has been shown to contribute to cancer progression in various cancers including leukemia, glioma, breast, pancreatic and prostate cancers. However, the significance of ACAT-1 and cholesterol esters (CE) is relatively understudied in ovarian cancer. In this in vitro study, we assessed the expression and contribution of ACAT-1 in ovarian cancer progression. We observed a significant increase in the expression of ACAT-1 and CE levels in a panel of ovarian cancer cell lines (OC-314, SKOV-3 and IGROV-1) compared to primary ovarian epithelial cells (normal controls). To confirm the tumor promoting capacity of ACAT-1, we inhibited ACAT-1 expression and activity by treating our cell lines with an ACAT inhibitor, avasimibe, or by stable transfection with ACAT-1 specific short hairpin RNA (shRNA). We observed significant suppression of cell proliferation, migration and invasion in ACAT-1 knockdown ovarian cancer cell lines compared to their respective controls (cell lines transfected with scrambled shRNA). ACAT-1 inhibition enhanced apoptosis with a concurrent increase in caspases 3/7 activity and decreased mitochondrial membrane potential. Increased generation of reactive oxygen species (ROS) coupled with increased expression of p53 may be the mechanism(s) underlying pro-apoptotic action of ACAT-1 inhibition. Additionally, ACAT-1 inhibited ovarian cancer cell lines displayed enhanced chemosensitivity to cisplatin treatment. These results suggest ACAT-1 may be a potential new target for the treatment of ovarian cancer.
Endometriosis is a common gynecological disease, which causes chronic pelvic pain and infertility in women of reproductive age. Due to limited efficacy of current treatment options, a critical need exists to develop new and effective treatments for endometriosis. Niclosamide is an efficacious and FDA-approved drug for the treatment of helminthosis in humans that has been used for decades. We have reported that niclosamide reduces growth and progression of endometriosis-like lesions via targeting STAT3 and NFĸB signaling in a mouse model of endometriosis. To examine the effects of niclosamide on macrophage-induced inflammation in endometriosis, a total of 29 stage III–IV endometrioma samples were used to isolate human endometriotic stromal cells (hESCs). M1 or M2 macrophages were isolated and differentiated from fresh human peripheral blood samples. Then, hESCs were cultured in conditioned media (CM) from macrophages with/without niclosamide. Niclosamide dose dependently reduced cell viability and the activity of STAT3 and NFκB signaling in hESCs. While macrophage CM stimulated cell viability in hESCs, niclosamide inhibited this stimulation. Macrophage CM stimulated the secretion of proinflammatory cytokines and chemokines from hESCs. Most of these secreted factors were inhibited by niclosamide. These results indicate that niclosamide is able to reduce macrophage-induced cell viability and cytokine/chemokine secretion in hESCs by inhibiting inflammatory mechanisms via STAT3 and/or NFκB signaling.
Epithelial ovarian cancer (OC) is the most deadly cancer of the female reproductive system. To date, there is no effective screening method for early detection of OC and current diagnostic armamentarium may include sonographic grading of the tumor and analyzing serum levels of tumor markers, Cancer Antigen 125 (CA-125) and Human epididymis protein 4 (HE4). Microorganisms (bacterial, archaeal, and fungal cells) residing in mucosal tissues including the gastrointestinal and urogenital tracts can be altered by different disease states, and these shifts in microbial dynamics may help to diagnose disease states. We hypothesized that the peritoneal microbial environment was altered in patients with OC and that inclusion of selected peritoneal microbial features with current clinical features into prediction analyses will improve detection accuracy of patients with OC. Blood and peritoneal fluid were collected from consented patients that had sonography confirmed adnexal masses and were being seen at SIU School of Medicine Simmons Cancer Institute. Blood was processed and serum HE4 and CA-125 were measured. Peritoneal fluid was collected at the time of surgery and processed for Next Generation Sequencing (NGS) using 16S V4 exon bacterial primers and bioinformatics analyses. We found that patients with OC had a unique peritoneal microbial profile compared to patients with a benign mass. Using ensemble modeling and machine learning pathways, we identified 18 microbial features that were highly specific to OC pathology. Prediction analyses confirmed that inclusion of microbial features with serum tumor marker levels and control features (patient age and BMI) improved diagnostic accuracy compared to currently used models. We conclude that OC pathogenesis alters the peritoneal microbial environment and that these unique microbial
Objectives Preeclampsia is associated with reduced trophoblast placenta growth factor (PGF) expression, elevated soluble fms-like tyrosine kinase-1 (sFlt-1) and decreased bioactivity of nitric oxide (NO). Elevated sFlt-1 reduces bioavailability of PGF and vascular endothelial growth factor (VEGF) leading to maternal endothelial dysfunction. Although NO can regulate gene expression, its ability to regulate trophoblast expression of angiogenic growth factors is not known. Study Design Human primary term trophoblast and JEG-3 choriocarcinoma cells were cultured under 21%O2 or 1%O2 conditions in the presence or absence of NO donor (SNP) or inhibitor (L-NAME). Effects on PGF, VEGF and Flt-1 isoform mRNA expression were determined by quantitative real time PCR. Changes in expression of soluble protein isoforms of FLT-1 was monitored by ELISA. Results Hypoxia decreased PGF mRNA but increased VEGF, sFlt-1 and Flt-1 mRNA expression in the trophoblast. Generation of NO in trophoblast under 1%O2 culture conditions significantly reversed sFlt-1 mRNA and protein expression, independent of mFlt-1. Conversely NO generation in hypoxic trophoblast increased VEGF and PGF mRNA expression. Conclusions NO production in primary human trophoblast cultures had divergent effects on pro-angiogenic (PGF, VEGF) versus anti-angiogenic (sFlt-1) mRNA expression, resulting in an enhanced pro-angiogenic gene expression environment in-vitro.
Endometriosis is an estrogen dependent gynecological disease associated with altered microbial phenotypes. The association among endogenous estrogen, estrogen metabolites, and microbial dynamics on disease pathogenesis has not been fully investigated. Here, we identified estrogen metabolites as well as microbial phenotypes in non-diseased patients (n = 9) and those with pathologically confirmed endometriosis (P-EOSIS, n = 20), on day of surgery (DOS) and ~1–3 weeks post-surgical intervention (PSI). Then, we examined the effects of surgical intervention with or without hormonal therapy (OCPs) on estrogen and microbial profiles of both study groups. For estrogen metabolism analysis, liquid chromatography/tandem mass spectrometry was used to quantify urinary estrogens. The microbiome data assessment was performed with Next generation sequencing to V4 region of 16S rRNA. Surgical intervention and hormonal therapy altered gastrointestinal (GI), urogenital (UG) microbiomes, urinary estrogen and estrogen metabolite levels in P-EOSIS. At DOS, 17β-estradiol was enhanced in P-EOSIS treated with OCPs. At PSI, 16-keto-17β-estradiol was increased in P-EOSIS not receiving OCPs while 2-hydroxyestradiol and 2-hydroxyestrone were decreased in P-EOSIS receiving OCPs. GI bacterial α-diversity was greater for controls and P-EOSIS that did not receive OCPs. P-EOSIS not utilizing OCPs exhibited a decrease in UG bacterial α-diversity and differences in dominant taxa, while P-EOSIS utilizing OCPs had an increase in UG bacterial α-diversity. P-EOSIS had a strong positive correlation between the GI/UG bacteria species and the concentrations of urinary estrogen and its metabolites. These results indicate an association between microbial dysbiosis and altered urinary estrogens in P-EOSIS, which may impact disease progression.
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