77 research outputs found

    Testosterone induction of prostaglandin-endoperoxide synthase 2 expression and prostaglandin F 2α production in hamster Leydig cells

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    We have previously observed expression of prostaglandin-endoperoxide synthase 2 (PTGS2), the key enzyme in the biosynthesis of prostaglandins (PGs), in reproductively active Syrian hamster Leydig cells, and reported an inhibitory role of PGF 2α on hamster testicular steroidogenesis. In this study, we further investigated PTGS2 expression in hamster Leydig cells during sexual development and photoperiodic gonadal regression. Since PTGS2 is mostly expressed in pubertal and reproductively active adult hamsters with high circulating levels of LH and androgens, we studied the role of these hormones in the regulation/maintenance of testicular PTGS2/PGF 2α. In active hamster Leydig cells, LH/hCG and testosterone induced PTGS2 and PGF 2α production, and their actions were abolished by the antiandrogen bicalutamide (Bi). These results indicate that LH does not exert a direct effect on PG synthesis. Testosterone also stimulated phosphorylation of the mitogen-activated protein kinase isoforms 3/1 (MAPK3/1) within minutes and hours, but the testosterone metabolite dihydrotestosterone had no effect on PTGS2 and MAPK3/1. Because Bi and U0126, an inhibitor of the MAP kinase kinases 1 and 2 (MAP2K1/2), abolished testosterone actions on MAPK3/1 and PTGS2, our studies suggest that testosterone directly induces PTGS2/PGF 2α in hamster Leydig cells via androgen receptors and a non-classical mechanism that involves MAPK3/1 activation. Since PGF 2α inhibits testosterone production, it might imply the existence of a regulatory loop that is setting a brake on steroidogenesis. Thus, the androgen environment might be crucial for the regulation of testicular PG production at least during sexual development and photoperiodic variations in hamsters.Instituto Multidisciplinario de Biología Celula

    Testosterone induction of prostaglandin-endoperoxide synthase 2 expression and prostaglandin F 2α production in hamster Leydig cells

    Get PDF
    We have previously observed expression of prostaglandin-endoperoxide synthase 2 (PTGS2), the key enzyme in the biosynthesis of prostaglandins (PGs), in reproductively active Syrian hamster Leydig cells, and reported an inhibitory role of PGF 2α on hamster testicular steroidogenesis. In this study, we further investigated PTGS2 expression in hamster Leydig cells during sexual development and photoperiodic gonadal regression. Since PTGS2 is mostly expressed in pubertal and reproductively active adult hamsters with high circulating levels of LH and androgens, we studied the role of these hormones in the regulation/maintenance of testicular PTGS2/PGF 2α. In active hamster Leydig cells, LH/hCG and testosterone induced PTGS2 and PGF 2α production, and their actions were abolished by the antiandrogen bicalutamide (Bi). These results indicate that LH does not exert a direct effect on PG synthesis. Testosterone also stimulated phosphorylation of the mitogen-activated protein kinase isoforms 3/1 (MAPK3/1) within minutes and hours, but the testosterone metabolite dihydrotestosterone had no effect on PTGS2 and MAPK3/1. Because Bi and U0126, an inhibitor of the MAP kinase kinases 1 and 2 (MAP2K1/2), abolished testosterone actions on MAPK3/1 and PTGS2, our studies suggest that testosterone directly induces PTGS2/PGF 2α in hamster Leydig cells via androgen receptors and a non-classical mechanism that involves MAPK3/1 activation. Since PGF 2α inhibits testosterone production, it might imply the existence of a regulatory loop that is setting a brake on steroidogenesis. Thus, the androgen environment might be crucial for the regulation of testicular PG production at least during sexual development and photoperiodic variations in hamsters.Instituto Multidisciplinario de Biología Celula

    Expression of the TGF-beta1 system in human testicular pathologies

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    In non-obstructive azoospermia, histological patterns of Sertoli cell-only Syndrome (SCO) and hypospermatogenesis (H) are commonly found. In these pathologies, Leydig cell hyperplasia (LCH) is detected in some patients. Since TGF-ÎČ1 is involved in cellular proliferation/development, the aim of this work was to analyze the expression of TGF-ÎČ1, its receptors TGFBRII, TGFBRI (ALK-1 and ALK-5), and the co-receptor endoglin in human biopsies from patients with idiopathic infertilityFil: Gonzalez, Candela Rocio. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Instituto de BiologĂ­a y Medicina Experimental (i); Argentina; Argentina. Universidad de Buenos Aires. Facultad de Medicina; ArgentinaFil: Matzkin, Maria Eugenia. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Instituto de BiologĂ­a y Medicina Experimental (i); Argentina; Argentina. Universidad de Buenos Aires. Facultad de Medicina; ArgentinaFil: Frungieri, Monica Beatriz. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Instituto de BiologĂ­a y Medicina Experimental (i); Argentina; Argentina. Universidad de Buenos Aires. Facultad de Medicina; ArgentinaFil: Terradas, Claudio. Gobierno de la Ciudad de Buenos Aires. Hospital General de Agudos"Carlos G. Durand"; Argentina. Instituto MĂ©dico IPREFER; ArgentinaFil: Ponzio, Roberto . Universidad de Buenos Aires. Facultad de Medicina; ArgentinaFil: Puigdomenech, Elisa. Instituto MĂ©dico IPREFER;; ArgentinaFil: Levalle, Oscar. Gobierno de la Ciudad de Buenos Aires. Hospital General de Agudos"Carlos G. Durand"; ArgentinaFil: Calandra, Ricardo Saul. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Instituto de BiologĂ­a y Medicina Experimental (i); Argentina; ArgentinaFil: Gonzalez Calvar, Silvia InĂ©s. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Instituto de BiologĂ­a y Medicina Experimental (i); Argentina; Argentina. Universidad de Buenos Aires. Facultad de Medicina; Argentin

    Testosterone induction of prostaglandin-endoperoxide synthase 2 expression and prostaglandin F 2α production in hamster Leydig cells

    Get PDF
    We have previously observed expression of prostaglandin-endoperoxide synthase 2 (PTGS2), the key enzyme in the biosynthesis of prostaglandins (PGs), in reproductively active Syrian hamster Leydig cells, and reported an inhibitory role of PGF 2α on hamster testicular steroidogenesis. In this study, we further investigated PTGS2 expression in hamster Leydig cells during sexual development and photoperiodic gonadal regression. Since PTGS2 is mostly expressed in pubertal and reproductively active adult hamsters with high circulating levels of LH and androgens, we studied the role of these hormones in the regulation/maintenance of testicular PTGS2/PGF 2α. In active hamster Leydig cells, LH/hCG and testosterone induced PTGS2 and PGF 2α production, and their actions were abolished by the antiandrogen bicalutamide (Bi). These results indicate that LH does not exert a direct effect on PG synthesis. Testosterone also stimulated phosphorylation of the mitogen-activated protein kinase isoforms 3/1 (MAPK3/1) within minutes and hours, but the testosterone metabolite dihydrotestosterone had no effect on PTGS2 and MAPK3/1. Because Bi and U0126, an inhibitor of the MAP kinase kinases 1 and 2 (MAP2K1/2), abolished testosterone actions on MAPK3/1 and PTGS2, our studies suggest that testosterone directly induces PTGS2/PGF 2α in hamster Leydig cells via androgen receptors and a non-classical mechanism that involves MAPK3/1 activation. Since PGF 2α inhibits testosterone production, it might imply the existence of a regulatory loop that is setting a brake on steroidogenesis. Thus, the androgen environment might be crucial for the regulation of testicular PG production at least during sexual development and photoperiodic variations in hamsters.Instituto Multidisciplinario de Biología Celula

    An overview of the progress and challenges of peatland restoration in Western Europe

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    Peatlands are the most efficient terrestrial carbon store on Earth, and deliver multiple other ecosystem services including climate regulation, water purification, preservation of ecological and archaeological records, etc. Disturbed and degraded peatlands do not provide the same ecological services and thus bear a significant cost to society. Because this cost may be alleviated by appropriate restoration measures, money is being invested in peatland restoration projects around the world. Here, we review over 25 years of restoration in Western Europe. First, we provide an overview of techniques used in different contexts and evaluate the status of the evidence base for restoration outcomes. Between 1993 and 2015, the EU-LIFE nature programme alone invested 167.6M € in 80 projects, which aim to restore over 913 km2 of peatland habitats in Western European countries, mostly in protected sites part of the Natura 2000 EU network. This represents less than 2% of the total remaining area of peatlands in these countries, most of which have been impacted to some degree by anthropogenic disturbances. Potential for restoration should be considered in nondesignated sites. We reviewed a number of case studies covering a range of restoration approaches used in different parts of Western Europe. We found that published evidence of restoration progress was limited to specific sites/areas, and in many cases lacked baseline measurements and clear goals, that is, measurable target or contemporary reference(s). We discuss barriers and opportunities to turn the tide for peatland restoration in Western Europe and promote the establishment of robust, standardized monitoring schemes

    Plasma?-III tubulin, neurofilament light chain and glial fibrillary acidic protein are associated with neurodegeneration and progression in schizophrenia

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    Schizophrenia is a progressive disorder characterized by multiple psychotic relapses. After every relapse, patients may not fully recover, and this may lead to a progressive loss of functionality. Pharmacological treatment represents a key factor to minimize the biological, psychological and psychosocial impact of the disorder. The number of relapses and the duration of psychotic episodes induce a potential neuronal damage and subsequently, neurodegenerative processes. Thus, a comparative study was performed, including forty healthy controls and forty-two SZ patients divided into first-episode psychosis (FEP) and chronic SZ (CSZ) subgroups, where the CSZ sub group was subdivided by antipsychotic treatment. In order to measure the potential neuronal damage, plasma levels of beta-III tubulin, neurofilament light chain (Nf-L), and glial fibrillary acidic protein (GFAP) were performed. The results revealed that the levels of these proteins were increased in the SZ group compared to the control group (P < 0.05). Moreover, multiple comparison analysis showed highly significant levels of beta-III tubulin (P = 0.0002), Nf-L (P = 0.0403) and GFAP (P < 0.015) in the subgroup of CSZ clozapine-treated. In conclusion, beta-III tubulin, Nf-L and GFAP proteins may be potential biomarkers of neurodegeneration and progression in SZ

    New Insights into the Apoptotic Process in Mollusks: Characterization of Caspase Genes in Mytilus galloprovincialis

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    Apoptosis is an essential biological process in the development and maintenance of immune system homeostasis. Caspase proteins constitute the core of the apoptotic machinery and can be categorized as either initiators or effectors of apoptosis. Although the genes encoding caspase proteins have been described in vertebrates and in almost all invertebrate phyla, there are few reports describing the initiator and executioner caspases or the modulation of their expression by different stimuli in different apoptotic pathways in bivalves. In the present work, we characterized two initiator and four executioner caspases in the mussel Mytilus galloprovincialis. Both initiators and executioners showed structural features that make them different from other caspase proteins already described. Evaluation of the genes’ tissue expression patterns revealed extremely high expression levels within the gland and gills, where the apoptotic process is highly active due to the clearance of damaged cells. Hemocytes also showed high expression values, probably due to of the role of apoptosis in the defense against pathogens. To understand the mechanisms of caspase gene regulation, hemocytes were treated with UV-light, environmental pollutants and pathogen-associated molecular patterns (PAMPs) and apoptosis was evaluated by microscopy, flow cytometry and qPCR techniques. Our results suggest that the apoptotic process could be tightly regulated in bivalve mollusks by overexpression/suppression of caspase genes; additionally, there is evidence of caspase-specific responses to pathogens and pollutants. The apoptotic process in mollusks has a similar complexity to that of vertebrates, but presents unique features that may be related to recurrent exposure to environmental changes, pollutants and pathogens imposed by their sedentary nature

    Disease recurrence in paediatric renal transplantation

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    Renal transplantation (Tx) is the treatment of choice for end-stage renal disease. The incidence of acute rejection after renal Tx has decreased because of improving early immunosuppression, but the risk of disease recurrence (DR) is becoming relatively high, with a greater prevalence in children than in adults, thereby increasing patient morbidity, graft loss (GL) and, sometimes, mortality rate. The current overall graft loss to DR is 7–8%, mainly due to primary glomerulonephritis (70–80%) and inherited metabolic diseases. The more typical presentation is a recurrence of the full disease, either with a high risk of GL (focal and segmental glomerulosclerosis 14–50% DR, 40–60% GL; atypical haemolytic uraemic syndrome 20–80% DR, 10–83% GL; membranoproliferative glomerulonephritis 30–100% DR, 17–61% GL; membranous nephropathy ∌30% DR, ∌50% GL; lipoprotein glomerulopathy ∌100% DR and GL; primary hyperoxaluria type 1 80–100% DR and GL) or with a low risk of GL [immunoglobulin (Ig)A nephropathy 36–60% DR, 7–10% GL; systemic lupus erythematosus 0–30% DR, 0–5% GL; anti-neutrophilic cytoplasmic antibody (ANCA)-associated glomerulonephritis]. Recurrence may also occur with a delayed risk of GL, such as insulin-dependent diabetes mellitus, sickle cell disease, endemic nephropathy, and sarcoidosis. In other primary diseases, the post-Tx course may be complicated by specific events that are different from overt recurrence: proteinuria or cancer in some genetic forms of nephrotic syndrome, anti-glomerular basement membrane antibodies-associated glomerulonephritis (Alport syndrome, Goodpasture syndrome), and graft involvement as a consequence of lower urinary tract abnormality or human immunodeficiency virus (HIV) nephropathy. Some other post-Tx conditions may mimic recurrence, such as de novo membranous glomerulonephritis, IgA nephropathy, microangiopathy, or isolated specific deposits (cystinosis, Fabry disease). Adequate strategies should therefore be added to kidney Tx, such as donor selection, associated liver Tx, plasmatherapy, specific immunosuppression protocols. In such conditions, very few patients may be excluded from kidney Tx only because of a major risk of DR and repeated GL. In the near future the issue of DR after kidney Tx may benefit from alternatives to organ Tx, such as recombinant proteins, specific monoclonal antibodies, cell/gene therapy, and chaperone molecules

    Osmotic coefficients of alcoholic mixtures containing BMpyrDCA: Experimental determination and correlation

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    The vapour pressure osmometry technique (VPO) has been used to obtain the osmotic coefficients of the binary mixtures of the primary and secondary alcohols 1-propanol, 2-propanol, 1-butanol, 2-butanol and 1-pentanol with the ionic liquid 1-butyl-1-methylpyrrolidinium dicyanamide, BMpyrDCA. From these coefficients, the corresponding activity coefficients and vapour pressures of the mixtures have been also determined. The results have been discussed in terms of solute-solvent and ion-ion interactions and have been compared with those taken from literature in order to analyse the influence of the anion or cation constituting the ionic liquid. For the treatment of the experimental data, the Extended Pitzer model of Archer and the MNRTL model have been applied, obtaining standard deviations from the experimental osmotic coefficients lower than 0.015 and 0.065, respectively. From the parameters obtained with the Extended Pitzer model or Archer, the mean molal activity coefficients and the excess Gibbs free energy for the studied mixtures have been calculated. (C) 2014 Published by Elsevier Ltd

    Influence of the structure of the cation of ionic liquids on the vapor pressure and osmotic coefficients in their binary mixtures with 1-propanol

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    The osmotic and activity coefficients and vapor pressures of binary mixtures containing the alcohol 1-propanol and the ionic liquids 1-ethyl-3-methylpyridinium bis(trifluoromethylsulfonyl)imide, C2MpyNTf2, 1-propyl-3- methylpyridinium bis(trifluoromethylsulfonyl)imide, C3MpyNTf2, 1-butyl-3-methylpyridinium bis(trifluoromethylsulfonyl)imide, C4MpyNTf2 and 1-butyl-3-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide, C4MpyrNTf2 were determined at T = 323.15 K using the vapor pressure osmometry technique. The experimental osmotic coefficients were correlated using the Extended Pitzer model of Archer obtaining standard deviations lower than 0.060. The mean molal activity coefficients and the excess Gibbs free energy for the studied mixtures were calculated from the parameters of the Extended Pitzer model of Archer. From the experimental determination, the influence of the alkyl-side chain of the cation and of the cation itself on the osmotic and activity coefficients and on the vapor pressures can be analyze
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