Clustering of ligand-binding receptors of different types on thickened isles of the cell membrane, namely lipid rafts, is an experimentally observed phenomenon. Although its influence on cell's response is deeply investigated, the role of the coupling between mechanical processes and multiphysics involving the active receptors and the surrounding lipid membrane during ligand-binding has not yet been understood. Specifically, the focus of this work is on (GPCRs), the widest group of transmembrane proteins in animals, which regulate specific cell processes through chemical signalling pathways involving a synergistic balance between the (cAMP) produced by active GPCRs in the intracellular environment and its efflux, mediated by the (MRPs) transporters.
View Article and Find Full Text PDFWe investigated the effect of high-frequency electromagnetic fields (HF-EMFs) and 17-β-estradiol on connexins (Cxs), integrins (Ints), and estrogen receptor (ER) expression, as well as on ultrastructure of trophoblast-derived HTR-8/SVneo cells. HF-EMF, 17-β-estradiol, and their combination induced an increase of Cx40 and Cx43 mRNA expression. HF-EMF decreased Int alpha1 and β 1 mRNA levels but enhanced Int alpha5 mRNA expression.
View Article and Find Full Text PDFReoperative surgery in the neck for recurrent differentiated thyroid cancer (DTC) is associated with increased morbidity compared with primary surgery. Radioguided occult lesion localization was recently proposed in patients with DTC recurrences. Here we report on the combination of radioguided occult lesion localization procedure to preoperative SPECT/CT in 2 patients with DTC recurrences.
View Article and Find Full Text PDFCircadian clock controls several physiological processes such as cell proliferation. Extravillous trophoblast proliferation is a tightly regulated function playing a fundamental role in maternal vessel remodeling. We recently demonstrated that clock genes Per2 and Dec1 as well as the clock-controlled genes Dbp and Vegf are rhythmically expressed in human extravillous trophoblast-derived HTR-8/SVneo cells.
View Article and Find Full Text PDFAims: Human amnion-derived cells have been used as in vitro models to test the release of inflammatory mediators, such as arachidonic acid (AA) and prostaglandin E(2) (PGE(2)). We compared estrogen metabolites for their ability to induce AA release, to influence PGE(2) production and to interact toward intracellular estrogen receptors (ERs).
Main Methods: Metabolite effects on AA and PGE(2) release were examined by radiolabelled substrate incorporation and by colorimetric enzyme immunoassays, respectively.
For many years glucocorticoids have been used world-wide in pregnant women for treatment of a variety of medical disorders, from bronchial asthma to systemic lupus erythematosous, to renal transplant. More recently their administration has been successfully addressed to the prevention of congenital fetal diseases. In some of these, such as for instance the 21-hydroxylase deficiency leading to congenital adrenal hyperplasia, the pathogenic mechanism is well known, while in others, such as the cystic adenomatoid malformation of the lung, it is not yet understood.
View Article and Find Full Text PDFCyclic adenosine 3'-5'-monophosphate (cAMP) is a second messenger, which exerts an important role in the control of human first-trimester trophoblast functions. In the present study we demonstrate the existence of a mechanism that is able to extrude cAMP from trophoblast-derived cell lines, and show evidence indicating the involvement of multidrug resistance protein (MRP) 1, a transporter belonging to the ATP-binding cassette family, in cAMP egress. MRP1 is expressed in trophoblast cell lines and cAMP efflux is highly reduced by the MRP1 inhibitor, MK-571.
View Article and Find Full Text PDFConnexins (Cx) are membrane proteins able to influence trophoblast functions. Here we investigated the effect of high-frequency electromagnetic fields (HF-EMF) on Cx expression and localization in extravillous trophoblast cell line HTR-8/SVneo. We also analysed cell ultrastructural changes induced by HF-EMF exposure.
View Article and Find Full Text PDFBiochem Biophys Res Commun
January 2009
Circadian clock governs daily rhythmicity of a number of physiological processes such as reproductive functions. The existence of circadian clocks in the placenta is not clearly established. In order to investigate whether human placenta may function as circadian oscillator, we utilized HTR-8/SVneo cells derived from human first-trimester trophoblast.
View Article and Find Full Text PDFWe have tested the hypothesis that human early trophoblast is a target for somatostatin (SRIF) regulatory actions. We report for the first time that SSTR2A and 2B transcripts and proteins are present in first-trimester human chorionic villi and the trophoblast-derived HTR-8/SVneo and JAR cells. In both cell lines, SSTR are functional since SRIF inhibits cyclic AMP pathway, stimulates arachidonic acid release and enhances cell proliferation.
View Article and Find Full Text PDFBackground: We previously demonstrated a high incidence (7.7%) of venous thromboembolism (VTE) in breast cancer patients treated with infusional chemotherapy after insertion of central vein catheters (CVC). The aim of this study was to evaluate the efficacy and safety of low-dose aspirin for the prevention of VTE.
View Article and Find Full Text PDFThe trophoblast, i.e. the peripheral part of the human conceptus, exerts a crucial role in implantation and placentation.
View Article and Find Full Text PDFVitamin C plays an important role in embryogenesis and fetal growth as well as in the progression of pregnancy and delivery. Therefore, it is important to understand the mechanism that mediates its transport to the fetus as well as the possible influences by endogenous and exogenous substances on its placental uptake. The aim of this study was to investigate placental sodium-dependent vitamin C transporters (SVCT) 1 and 2.
View Article and Find Full Text PDFNormal placentation requires a highly coordinated control of proliferation, migration and invasiveness of extravillous trophoblast cells. Since prostaglandin E2 is a major prostanoid synthesized by intrauterine tissues and highly involved in pregnancy homeostasis, we examined the possibility that it modulates extravillous trophoblast cell functions. Here, we report the presence of mRNAs for prostaglandin E2 EP2 and EP4 receptor isoforms and of proteins in both first-trimester human chorionic villi and in the human trophoblast-derived HTR-8/SVneo cells.
View Article and Find Full Text PDFOxidative processes exert a fundamental regulatory function during pregnancy. It depends on the influence of oxygen, nitric oxide, reactive oxygen species and reactive nitrogen species metabolic pathways upon the vascular changes in the maternal organism, as well as on the regulation of uterine and cervical tone throughout gestation and delivery. These functions are strictly linked with the mediators of the inflammatory pathway.
View Article and Find Full Text PDFNaunyn Schmiedebergs Arch Pharmacol
August 2004
The peptide somatostatin-14 (SRIF) acts in the mammalian retina through its distinct receptors (sst(1-5)). Scarce information is available on SRIF function in the retina, including the elucidation of transduction pathways mediating SRIF action. We have investigated SRIF and SRIF receptor modulation of adenylyl cyclase (AC) activity in both wild-type (WT) retinas and sst1 or sst2 knock-out (KO) retinas, which are known to over-express sst2 or sst1 receptors respectively.
View Article and Find Full Text PDFBackground: Hepatic intra-arterial chemotherapy (HIAC) leads to a higher response rate than systemic administration in untreated patients with liver metastases from colorectal cancer (CRC). The aim of this study was to evaluate the activity and safety of giving HIAC through a percutaneous catheter in pre-treated patients.
Patients And Methods: Forty-five CRC patients with liver-only or liver-dominant metastases, resistant or refractory to previous systemic therapy, were treated using a temporary trans-subclavian catheter.
Objective: To test the effect of ampicillin on amniotic interleukin-6 (IL-6) and prostaglandin E2 (PGE2) release.
Methods: In an in vitro study, IL-6 and PGE2 release from amnion-like Wistar Institute Susan Hayflick cells was assayed under basal conditions, as well as after incubation with ampicillin. In an in vivo study, amniotic fluid IL-6 was assayed in a total of 212 patients submitted to genetic amniocentesis during the 17th week of their singleton physiological pregnancy.
17beta-Estradiol (17beta-E(2)) greatly and dose-dependently stimulates [(3)H]arachidonic acid (AA) release from the human amnion-like Wistar Institute Susan Hayflick (WISH) cells. This action is abolished by the phospholipase A(2) inhibitor AACOCF(3), significantly reduced by the estrogen receptor (ER) antagonist ICI 182,780, and uninfluenced by cycloheximide. The estradiol-BSA conjugate E(2)coBSA, which binds putative membrane ERs and is unable to enter the cell, also highly stimulates [(3)H]AA release from WISH cells, although to a lesser extent compared with 17beta-E(2).
View Article and Find Full Text PDFIn human amnion-derived WISH cells [(3)H]estradiol-17beta binding sites are not detectable, but they become measurable in cells exposed to cAMP elevating agents such as forskolin or Ro 20-1724. In cells unexposed to these drugs, 17beta-estradiol stimulates prostaglandin (PG)E(2) release but exerts an evident inhibitory effect in cells exposed to Ro 20-1724. Both stimulatory and inhibitory actions are inhibited by the estrogen receptor antagonist, tamoxifen, by cell pretreatment with cycloheximide, or when the hormone is bound to BSA.
View Article and Find Full Text PDFPurpose: Chemotherapy administered as a continuous infusion is a widely used treatment in oncology. Huber needle deserves close attention during chemotherapy, but no data are reported on how long it can be left in situ without change. We therefore evaluated the feasibility of leaving in situ the needle for a prolonged time.
View Article and Find Full Text PDFThe object of this study was to evaluate whether phthalic acid, which is one of the metabolites of phthalic acid esters, exerts estrogenic actions in WISH cells, an immortalized cell line derived from human amniotic tissue. Our data demonstrate that phthalic acid (i) displaces [3H]estradiol from its binding sites, (ii) enhances the intracellular cyclic AMP concentration, without influencing adenylyl cyclase activity, (iii) stimulates or inhibits prostaglandin output, probably depending on the intracellular nucleotide level. The effects on prostanoid release are counteracted by addition of the protein-synthesis inhibitor cycloheximide, or when the diffusion of phthalic acid through the cell membrane is prevented.
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