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Monica Beatriz Frungieri - One of the best experts on this subject based on the ideXlab platform.
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aging in the Syrian Hamster testis inflammatory oxidative status and the impact of photoperiod
Experimental Gerontology, 2019Co-Authors: Maria Eugenia Matzkin, Andrzej Bartke, Paula Valchi, Eugenia Riviere, Soledad Paola Rossi, Yamil Ezequiel Tavalieri, Monica Munoz De Toro, Artur Mayerhofer, Ricardo S Calandra, Monica Beatriz FrungieriAbstract:Abstract Testicular aging is linked to histological, morphological and functional alterations. In the present study, we investigated whether aging affects the inflammatory and oxidative status in the testis by comparing young adult, middle-aged adult and aged Hamsters. The Syrian Hamster, a thoroughly studied seasonal breeder, was chosen as the experimental model since it allows further investigations on the role of photoperiod and melatonin in testicular aging with a minimal impact of the experimental intervention on the animal well-being and the subsequent results achieved. In testes of aged Hamsters, we found a decrease in melatonin concentration, a thickening of the wall of the seminiferous tubules as well as a significant increase in IL-1β, NLRP3 and cyclooxygenase 2 expression, PGD2 production, macrophages numbers, lipid peroxidation and anti-oxidant enzyme catalase levels. Interestingly, when aged Hamsters were transferred from a long day (LD) to a short day (SD) photoperiod for 16 weeks, testicular melatonin concentration increased while local inflammatory processes and oxidative stress were clearly reduced. Overall, these results indicate that melatonin might display anti-inflammatory and anti-oxidant capacities in the aged testes.
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cyclooxygenase 2 and prostaglandin f2α in Syrian Hamster leydig cells inhibitory role on luteinizing hormone human chorionic gonadotropin stimulated testosterone production
Endocrinology, 2006Co-Authors: Artur Mayerhofer, Monica Beatriz Frungieri, Silvia I Gonzalezcalvar, Fernanda Parborell, Martin Albrecht, Ricardo S CalandraAbstract:We have previously found that cyclooxygenase-2 (COX-2), a key enzyme in the biosynthesis of prostaglandins (PGs), is present in the testicular interstitial cells of infertile men, whereas it is absent in human testes with no evident morphological changes or abnormalities. To find an animal model for further investigating COX-2 and its role in testicular steroidogenesis, we screened testes from adult species ranging from mice to monkeys. By using immunohistochemical assays, we found COX-2 expression only in Leydig cells of the reproductively active (peripubertal, pubertal, and adult) seasonal breeder Syrian Hamster. COX-2 expression in Hamster Leydig cells was confirmed by RT-PCR. In contrast, COX-1 expression was not detected in Hamster testes. Because COX-2 expression implies PG synthesis, we investigated the effect of various PGs on testosterone production and found that PGF2 alpha stood out because it significantly reduced human chorionic gonadotropin-stimulated testosterone release from isolated Hamster Leydig cells in a dose-dependent manner. This mechanism involves a decreased expression of testicular steroidogenic acute regulatory protein and 17beta-hydroxysteroid dehydrogenase. Testicular concentration and content of PGF2 alpha in reproductively active Hamsters as well as production of PGF2 alpha from isolated Hamster Leydig cells were also determined. Moreover, PGF2 alpha receptors were localized in Leydig cells of Hamsters and testicular biopsies from patients with Sertoli cell only and germ arrest syndromes. Thus, in this study, we described a COX-2-initiated pathway that via PGF2 alpha production, PGF2 alpha receptors, steroidogenic acute regulatory protein, and 17beta-hydroxysteroid dehydrogenase represents a physiological local inhibitory system of human chorionic gonadotropin-stimulated testosterone production in the Syrian Hamster testes.
Ricardo S Calandra - One of the best experts on this subject based on the ideXlab platform.
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aging in the Syrian Hamster testis inflammatory oxidative status and the impact of photoperiod
Experimental Gerontology, 2019Co-Authors: Maria Eugenia Matzkin, Andrzej Bartke, Paula Valchi, Eugenia Riviere, Soledad Paola Rossi, Yamil Ezequiel Tavalieri, Monica Munoz De Toro, Artur Mayerhofer, Ricardo S Calandra, Monica Beatriz FrungieriAbstract:Abstract Testicular aging is linked to histological, morphological and functional alterations. In the present study, we investigated whether aging affects the inflammatory and oxidative status in the testis by comparing young adult, middle-aged adult and aged Hamsters. The Syrian Hamster, a thoroughly studied seasonal breeder, was chosen as the experimental model since it allows further investigations on the role of photoperiod and melatonin in testicular aging with a minimal impact of the experimental intervention on the animal well-being and the subsequent results achieved. In testes of aged Hamsters, we found a decrease in melatonin concentration, a thickening of the wall of the seminiferous tubules as well as a significant increase in IL-1β, NLRP3 and cyclooxygenase 2 expression, PGD2 production, macrophages numbers, lipid peroxidation and anti-oxidant enzyme catalase levels. Interestingly, when aged Hamsters were transferred from a long day (LD) to a short day (SD) photoperiod for 16 weeks, testicular melatonin concentration increased while local inflammatory processes and oxidative stress were clearly reduced. Overall, these results indicate that melatonin might display anti-inflammatory and anti-oxidant capacities in the aged testes.
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cyclooxygenase 2 and prostaglandin f2α in Syrian Hamster leydig cells inhibitory role on luteinizing hormone human chorionic gonadotropin stimulated testosterone production
Endocrinology, 2006Co-Authors: Artur Mayerhofer, Monica Beatriz Frungieri, Silvia I Gonzalezcalvar, Fernanda Parborell, Martin Albrecht, Ricardo S CalandraAbstract:We have previously found that cyclooxygenase-2 (COX-2), a key enzyme in the biosynthesis of prostaglandins (PGs), is present in the testicular interstitial cells of infertile men, whereas it is absent in human testes with no evident morphological changes or abnormalities. To find an animal model for further investigating COX-2 and its role in testicular steroidogenesis, we screened testes from adult species ranging from mice to monkeys. By using immunohistochemical assays, we found COX-2 expression only in Leydig cells of the reproductively active (peripubertal, pubertal, and adult) seasonal breeder Syrian Hamster. COX-2 expression in Hamster Leydig cells was confirmed by RT-PCR. In contrast, COX-1 expression was not detected in Hamster testes. Because COX-2 expression implies PG synthesis, we investigated the effect of various PGs on testosterone production and found that PGF2 alpha stood out because it significantly reduced human chorionic gonadotropin-stimulated testosterone release from isolated Hamster Leydig cells in a dose-dependent manner. This mechanism involves a decreased expression of testicular steroidogenic acute regulatory protein and 17beta-hydroxysteroid dehydrogenase. Testicular concentration and content of PGF2 alpha in reproductively active Hamsters as well as production of PGF2 alpha from isolated Hamster Leydig cells were also determined. Moreover, PGF2 alpha receptors were localized in Leydig cells of Hamsters and testicular biopsies from patients with Sertoli cell only and germ arrest syndromes. Thus, in this study, we described a COX-2-initiated pathway that via PGF2 alpha production, PGF2 alpha receptors, steroidogenic acute regulatory protein, and 17beta-hydroxysteroid dehydrogenase represents a physiological local inhibitory system of human chorionic gonadotropin-stimulated testosterone production in the Syrian Hamster testes.
Ana Cotomontes - One of the best experts on this subject based on the ideXlab platform.
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analysis of constant tissue remodeling in Syrian Hamster harderian gland intra tubular and inter tubular syncytial masses
Journal of Anatomy, 2013Co-Authors: Ana Cotomontes, Russel J Reiter, Beatriz Caballero, Veronica Sierra, Marina Garciamacia, Maria Josefa Rodriguezcolunga, Ignacio VeganaredoAbstract:The Syrian Hamster Harderian gland (HG) has a marked sexual dimorphism and exhibits an extraordinary rate of porphyrinogenesis. The physiological oxidative stress, derived from constant porphyrin production, is so high that the HG needs additional survival autophagic mechanisms to fight against this chronic exposure, provoking the triggering of a holocrine secretion in female glands that forms two types of secretory masses: intra-tubular-syncytial and inter-tubular-syncytial masses. The aim of this work was to study the development of this inter-tubular holocrine secretion. To approach this task, we have considered that the steps developed during the formation of the so-called invasive masses consist of the growth of epithelial cells, cell detachment from the basal lamina and invasion of surrounding tissues. The presence of these masses, particularly in the female HG, are closely linked to sexual dimorphism in redox balance and to alterations in the expression of certain factors such as cytokeratins, P-cadherin, matrix metalloproteinases, cathepsin H, proliferating cell nuclear antigen, p53, CD-31 and vascular endothelial growth factor, which seem to be involved in tissue remodeling. The results document unusual mechanisms of secretion in Syrian Hamster HG: an extraordinary system of massive secretion through the conjunctive tissue, disrupting the branched structure of the gland.
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sexual dimorphism of autophagy in Syrian Hamster harderian gland culminates in a holocrine secretion in female glands
Autophagy, 2009Co-Authors: Ignacio Veganaredo, Beatriz Caballero, Veronica Sierra, Covadonga Huidobrofernandez, David De Gonzalocalvo, Marina Garciamacia, Delio Tolivia, Maria Josefa Rodriguezcolunga, Ana CotomontesAbstract:The Syrian Hamster Harderian gland (HG) has a large porphyrin metabolism with a sexual dimorphism, showing male HGs much lower porphyrin concentrations than female glands. Damage derived from this production of porphyrins, displayed by reactive oxygen species, forces the gland to develop morphological changes that must have a physiological significance. Thus, oxidative stress is present in two states: mild oxidative stress in male HGs and extreme oxidative stress in female HGs. Cathepsins data gave indirect indications about the presence of programmed cell death affecting the lysosomal pathway, especially in female HGs, which showed an accumulation of autophagic bodies. Our results showed different degrees of autophagy in Syrian Hamster HGs depending on sex and probably controlled by the redox-sensitive transcription factors: NF-kappaB and p53. The discovery of these sexual dimorphisms in redox signaling and in autophagy corroborates previous findings and underlines the key role of reactive oxygen species...
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physiological autophagy in the Syrian Hamster harderian gland
Methods in Enzymology, 2009Co-Authors: Ignacio Veganaredo, Ana CotomontesAbstract:Abstract The Syrian Hamster Harderian gland (HG) displays a huge porphyrins metabolism with sexual dimorphism. Even in male Syrian Hamsters with much lower porphyrins concentration than female HG, this activity is higher than in the liver. The damage derived from constant porphyrin production, displayed by reactive oxygen species, forces the gland to develop mechanisms that allow it to continue with its normal physiology. The survival strategy of the Harderian gland is mainly based on autophagic processes that are considered as a constant renovation system. Our results show different autophagy mechanisms in Syrian Hamster HG, macroautophagy and other lysosomal‐like processes such as chaperone‐mediated autophagy, depending on sex and probably related to oxidative stress status. This chapter describes the methods used by us to characterize the autophagic processes that are being physiologically developed by this organ under normal conditions.
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coexpression of mt1 and roralpha1 melatonin receptors in the Syrian Hamster harderian gland
Journal of Pineal Research, 2005Co-Authors: Cristina Tomaszapico, Ignacio Veganaredo, Beatriz Caballero, Veronica Sierra, Delio Tolivia, Maria Josefa Rodriguezcolunga, Jose Antonio Boga, Oscar Alvarezgarcia, Ana CotomontesAbstract:Melatonin acts through several specific receptors, including membrane receptors (MT(1) and MT(2)) and members of the RZR/ROR nuclear receptors family, which have been identified in a large variety of mammalian and nonmammalian cells types. Both membrane and nuclear melatonin receptors have been partially characterized in Harderian gland of the Syrian Hamster. Nevertheless, the identities of these receptors were unknown until this study, where the coexistence of MT(1) and RORalpha(1) in this gland was determined by nested RT-PCR followed by amplicon sequencing and Western-blot. Furthermore, the cellular localization of both receptors was determined by immunohistochemistry. Thus, MT(1) receptor was localized exclusively at the basal side of the cell acini, supporting the hypothesis that this receptor is activated by the pineal-synthesized melatonin. On the contrary, although a RORalpha(1)-immunoreactivity was observed in nuclei of epithelial cells of both sexes, an extranuclear specific staining, which was more frequently among those cells of males, was also seen. The implication of this possible nuclear exclusion of RORalpha(1) on the role of this indoleamine against oxidative stress is discussed.
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physiological oxidative stress model Syrian Hamster harderian gland sex differences in antioxidant enzymes
Free Radical Biology and Medicine, 2001Co-Authors: Ana Cotomontes, Maria Josefa Rodriguezcolunga, Cristina Tomaszapico, Jose Antonio Boga, Jorge Martinezfraga, Delio Toliviacadrecha, Gloria Menendez, Rudiger Hardeland, Delio ToliviaAbstract:The Syrian Hamster Harderian gland, a juxtaorbital organ exhibiting marked gender-associated differences in contents of porphyrins and melatonin, was used as a model system for comparing strong (in females) and moderate (in males) physiological oxidative stress. Histological differences showing much higher cell damage in females were studied in conjunction with lipid peroxidation and activities of superoxide dismutase, catalase, glutathione peroxidase, and glutathione reductase. Lipid peroxidation and enzyme activities were measured throughout the circadian cycle, revealing the importance of dynamical processes in oxidative stress. Especially in lipid peroxidation and in catalase, short-lasting rises exhibited strongest gender differences. Peaks of lipid peroxidation were about three times higher in females, compared to males. Catalase peaks of females exceeded those in males by several hundred-fold. Average levels of superoxide dismutase and glutathione peroxidase were about three or two times higher in females, respectively. A clear-cut diurnally peaking rhythm was found in glutathione peroxidase of females, which was not apparent in males. Glutathione reductase showed differences in time patterns, but less in average activities. The time courses of lipid peroxidation and of protective enzymes are not explained by circulating melatonin, whereas melatonin formed in the Harderian gland should contribute to differences in average levels. Neither damage nor antioxidative defense simply reflect the illumination cycle and are, therefore, not only a consequence of photoreactions.
Silvia I Gonzalezcalvar - One of the best experts on this subject based on the ideXlab platform.
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cyclooxygenase 2 and prostaglandin f2α in Syrian Hamster leydig cells inhibitory role on luteinizing hormone human chorionic gonadotropin stimulated testosterone production
Endocrinology, 2006Co-Authors: Artur Mayerhofer, Monica Beatriz Frungieri, Silvia I Gonzalezcalvar, Fernanda Parborell, Martin Albrecht, Ricardo S CalandraAbstract:We have previously found that cyclooxygenase-2 (COX-2), a key enzyme in the biosynthesis of prostaglandins (PGs), is present in the testicular interstitial cells of infertile men, whereas it is absent in human testes with no evident morphological changes or abnormalities. To find an animal model for further investigating COX-2 and its role in testicular steroidogenesis, we screened testes from adult species ranging from mice to monkeys. By using immunohistochemical assays, we found COX-2 expression only in Leydig cells of the reproductively active (peripubertal, pubertal, and adult) seasonal breeder Syrian Hamster. COX-2 expression in Hamster Leydig cells was confirmed by RT-PCR. In contrast, COX-1 expression was not detected in Hamster testes. Because COX-2 expression implies PG synthesis, we investigated the effect of various PGs on testosterone production and found that PGF2 alpha stood out because it significantly reduced human chorionic gonadotropin-stimulated testosterone release from isolated Hamster Leydig cells in a dose-dependent manner. This mechanism involves a decreased expression of testicular steroidogenic acute regulatory protein and 17beta-hydroxysteroid dehydrogenase. Testicular concentration and content of PGF2 alpha in reproductively active Hamsters as well as production of PGF2 alpha from isolated Hamster Leydig cells were also determined. Moreover, PGF2 alpha receptors were localized in Leydig cells of Hamsters and testicular biopsies from patients with Sertoli cell only and germ arrest syndromes. Thus, in this study, we described a COX-2-initiated pathway that via PGF2 alpha production, PGF2 alpha receptors, steroidogenic acute regulatory protein, and 17beta-hydroxysteroid dehydrogenase represents a physiological local inhibitory system of human chorionic gonadotropin-stimulated testosterone production in the Syrian Hamster testes.
Dietmar Schiffmann - One of the best experts on this subject based on the ideXlab platform.
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evidence that ultrafine titanium dioxide induces micronuclei and apoptosis in Syrian Hamster embryo fibroblasts
Environmental Health Perspectives, 2002Co-Authors: Qamar Rahman, Mohtashim Lohani, Elke Dopp, Heidemarie Pemsel, Ludwig Jonas, Dieter G Weiss, Dietmar SchiffmannAbstract:Inhaled ultrafine titanium dioxide (UF-TiO2) particles cause pronounced pulmonary inflammation, in contrast to fine TiO2. Previous studies provide evidence for the production of reactive oxygen species by alveolar macrophages, after overloading with UF-TiO2 particles and cytotoxicity of UF-TiO2 in rat lung alveolar macrophages. UF-TiO2 also causes pulmonary fibrosis and lung tumors in rats. UF-TiO2 particles are photogenotoxic, but in general, information on the genotoxicity of UF-TiO2 is still limited. We studied the potential of UF-TiO2 (particle size less than or equal to 20 nm) and fine TiO2 (particle size > 200 nm) to induce chromosomal changes, which can be monitored by the formation of micronuclei (MN) in Syrian Hamster embryo (SHE) cells. We also analyzed UF-TiO2-treated cells for apoptosis induction. The MN assay revealed a significant increase in MN induction (p less than or equal to 0.05) in SHE cells after treatment with UF-TiO2 (1.0 micro g/cm2) for 12 hr (mean, 24.5 MN/1,000 cells), 24 hr (mean, 31.13 MN/1,000 cells), 48 hr (mean, 30.8 MN/1,000 cells), 66 hr (mean, 31.2 MN/1,000 cells), and 72 hr (mean, 31.3 MN/1,000 cells). Bisbenzimide staining of the fixed cells revealed typical apoptotic structures (apoptotic bodies), and the apoptosis-specific "DNA ladder pattern" resulting from internucleosomal cleavage was identified by gel electrophoresis. Furthermore, transmission electron microscopy of the exposed cells revealed the typical chromatin compaction of apoptosis.
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5 azacytidine induces micronuclei in and morphological transformation of Syrian Hamster embryo fibroblasts in the absence of unscheduled dna synthesis
Mutation Research Letters, 1992Co-Authors: Helga Stopper, R Pechan, Dietmar SchiffmannAbstract:Abstract It is known that 5-azacytidine (5-AC) induces tumors in several organs of rats and mice. The mechanisms of these effects are still poorly understood although it is known that 5-AC can be incorporated into DNA. Furthermore, it can inhibit DNA methylaion. The known data on its clastogenic and/or gene mutation-inducing potential are still controversial. Therefore, we have investigated the kinds of genotoxic effects caused by 5-AC in Syrian Hamster embryo (SHE) fibroblasts. Three different endpoints (micronucleus formation, unscheduled DNA synthesis (UDS) and cell trnsformation) were assayed under similar conditions of metabolism and dose at target in this cell system, 5-AC induces morphological transformation of SHE cells, but not UDS. Therefore, 5-AC does not seem to cause repairable DNA lesions. Furthermore, our studies revealed that 5-AC is a potent inducer of micronuclei in the SHE system. Immunocytochemical analysis revealed that a certain percentage of these contain kinetochores indicating that 5-AC may induce both clastogenic events and numerical chromosome changes.
