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Silvia Fasano - One of the best experts on this subject based on the ideXlab platform.
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anandamide modulates the expression of gnrh ii and gnrhrs in frog Rana esculenta diencephalon
General and Comparative Endocrinology, 2011Co-Authors: Rosanna Chianese, Riccardo Pierantoni, Silvia Fasano, Vincenza Ciaramella, Rosaria MeccarielloAbstract:Abstract In the hypothalamus, endocannabinoids affect neuroendocrine activity by means of Gonadotropin-Releasing-Hormone-I (GnRH-I) inhibition. Since most vertebrates, human included, possess at least two GnRH molecular forms, the aim of this work was to investigate the effect of endocannabinoids on GnRH molecular forms other than GnRH-I and on GnRHRs. Thus, we cloned GnRH precursors as well as GnRH receptors (GnRHR-I, GnRHR-II, GnRHR-III) from the diencephalons of the anuran amphibian, Rana esculenta. GnRH-II expression was evaluated in pituitary, whole brain, spinal cord, hindbrain, midbrain and forebrain during the annual sexual cycle. Then, in post-reproductive period (May), GnRH-I, GnRH-II and GnRHRs expression was evaluated by quantitative real time (qPCR) after incubation of diencephalons with the endocannabinoid anandamide (AEA). AEA significantly decreased GnRH-I and GnRH-II expression, up regulated GnRHR-I and GnRHR-II mRNA and it had no effect upon GnRHR-III expression. These effects were counteracted by SR141716A (Rimonabant), a selective antagonist of type I cannabinoid receptor (CB1). In conclusion our results demonstrate a CB1 receptor dependent modulation of GnRH system expression rate (both ligands and receptors) in frog diencephalons. In particular, we show that AEA, besides GnRH-I, also acts on GnRH-II expression.
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interplay between the endocannabinoid system and gnrh i in the forebrain of the anuran amphibian Rana esculenta
Endocrinology, 2008Co-Authors: Rosaria Meccariello, Riccardo Pierantoni, Gilda Cobellis, Rosanna Chianese, Donatella Scarpa, Maria Fosca Franzoni, Erika Cottone, Daniela Donna, Alda Guastalla, Silvia FasanoAbstract:The morphofunctional relationship between the endocannabinoid system and GnRH activity in the regulation of reproduction has poorly been investigated in vertebrates. Due to the anatomical features of lower vertebrate brain, in the present paper, we chose the frog Rana esculenta (anuran amphibian) as a suitable model to better investigate such aspects of the reproductive physiology. By using double-labeling immunofluorescence aided with a laser-scanning confocal microscope, we found a subpopulation of the frog hypothalamic GnRH neurons endowed with CB1 cannabinoid receptors. By means of semiquantitative RT-PCR assay, we have shown that, during the annual sexual cycle, GnRH-I mRNA (formerly known as mammalian GnRH) and CB1 mRNA have opposite expression profiles in the brain. In particular, this occurs in telencephalon and diencephalon, the areas mainly involved in GnRH release and control of the reproduction. Furthermore, we found that the endocannabinoid anandamide is able to inhibit GnRH-I mRNA synthesis; buserelin (a GnRH agonist), in turn, inhibits the synthesis of GnRH-I mRNA and induces an increase of CB1 transcription. Our observations point out the occurrence of a morphofunctional anatomical basis to explain a reciprocal relationship between the endocannabinoid system and GnRH neuronal activity.
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ubpy msj 1 system during male germ cell progression in the frog Rana esculenta
General and Comparative Endocrinology, 2007Co-Authors: Rosaria Meccariello, Riccardo Pierantoni, Gilda Cobellis, Rosanna Chianese, Donatella Scarpa, Giovanna Berruti, Silvia FasanoAbstract:mUBPy (mouse ubiquitin specific processing protease) is a de-ubiquitinating enzyme expressed in mouse testis and brain. In testis, it interacts with the DnaJ protein MSJ-1 (mouse sperm cell specific DnaJ first homologue), a molecular chaperone expressed in spermatids and spermatozoa. Since MSJ-1 is conserved among vertebrates, to demonstrate an evolutionarily conserved function of UBPy/MSJ-1 system, we assayed mUBPy presence in the anuran amphibian, the frog, Rana esculenta, during the annual sexual cycle. By Western blot we have detected a specific signal of 126 kDa in testis and isolated spermatozoa. During the annual sexual cycle, the signal gradually increases as soon as spermatogenesis resumes after the winter stasis. Using immunocytochemistry, we have localized the protein in spermatids and spermatozoa. In conclusion, UBPy/MSJ-1 system is available in R. esculenta testis suggesting a conserved fundamental function in spermatogenesis and sperm formation.
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c fos activity in Rana esculenta testis seasonal and estradiol induced changes
Endocrinology, 1999Co-Authors: Gilda Cobellis, Sergio Minucci, Riccardo Pierantoni, Roberto Pernasalonso, Rosaria Meccariello, Silvia FasanoAbstract:Estradiol-17β (E2) is suspected to exert a role in the regulation of testicular activity. Using a nonmammalian vertebrate model (the frog, Rana esculenta), we have investigated whether c-fos activity is detectable in the testis during the annual sexual cycle and whether E2 exerts a regulatory role on spermatogenesis through fos activity. FOS protein is available in testicular nuclear extracts (about 60 kDa) and, surprisingly, also in cytosolic extracts (about 60, 80, and 100 kDa). Estradiol induces primary spermatogonia (ISPG) proliferation [this effect is counteracted by antiestrogens (Tamoxifen and ICI 182–780)] and FOS appearance in testicular cytosolic extracts as well as c-fos transcription. Also, this effect is counteracted by ICI 182–780. Interestingly, the number of FOS immunopositive nuclei of ISPG strongly increases after E2 treatment, whereas a great increase of immunopositivity in the cytoplasm of ISPG is observed with the contemporaneous treatment with antiestrogens. In conclusion, our result...
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17β estradiol effects on mast cell number and spermatogonial mitotic index in the testis of the frog Rana esculenta
Journal of Experimental Zoology, 1997Co-Authors: Sergio Minucci, Loredana Di Matteo, Riccardo Pierantoni, Paolo Chieffi, Silvia FasanoAbstract:Estrogen affects mast cell activity and cellular proliferation in several vertebrate tissues. Due to the presence of mast cells in the interstitial tissue of the testis and due to the annual changes of spermatogonial proliferation and estradiol level in the frog, Rana esculenta, we have studied the possible regulation of mast cell number (MCN) and primary spermatogonial mitosis exerted by 17β-estradiol (E2). MCN changed in the testis during the annual reproductive cycle, showing peaks in December and in May. Administration of E2 elicited an increase of MCN both in intact and hypophysectomized frogs, and this effect was counteracted by tamoxifen. In vitro experiments indicated that E2 induced an increase of both MCN and the primary spermatogonial mitotic index. Moreover, a significant decrease of intratesticular androgen content was measured in E2-treated testes. All the in vitro effects induced by E2 were counteracted by tamoxifen. In conclusion, our data indicate that in Rana esculenta testis E2 increases MCN and primary spermatogonial mitotic index via intratesticular mechanisms. A possible involvement of the decrease of androgen levels exerted by E2 in the mechanism underlying the increase of MCN is also considered. J. Exp. Zool. 278:93–100, 1997. © 1997 Wiley-Liss, Inc.
Massimo Zerani - One of the best experts on this subject based on the ideXlab platform.
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role of nitric oxide in gonadotropin releasing hormone dependent prostaglandin f2α synthesis by frog Rana esculenta interrenal gland during post reproduction
Prostaglandins & Other Lipid Mediators, 1998Co-Authors: Anna Gobbetti, L Bellinicardellini, Massimo ZeraniAbstract:Abstract The aim of this study was to clarify the possible involvement of nitric oxide (NO) on prostaglandin (PG) E2-9-ketoreductase activity in the gonadotropin-releasing hormone (GnRH)-dependent PGF2α synthesis by the interrenal gland of the female water frog, Rana esculenta, during the post-reproduction. Interrenal glands were incubated in vitro with GnRH, NO donor (sodium nitroprusside, SNP), and inhibitors of phospholipase C (compound 48/80), inositol triphosphate (decavanadate), calmodulin (calmidazolium), NO synthase ( L -NAME), and PGE2-9-ketoreductase (palmitic acid). Production of PGE2 and PGF2α and NO synthase and PGE2-9-ketoreductase activities were determined. GnRH and SNP increased PGF2α production and PGE2-9-ketoreductase activity, and decreased production of PGE2 and GnRH increased NO synthase activity. GnRH effects were blocked by all inhibitors, except for palmitic acid, which did not affect NO synthase activity, which is increased by GnRH. This study indicates that NO may be involved in regulation of the R. esculenta post-reproduction through stimulation of PGE2-9-ketoreductase activity in GnRH-dependent PGF2α synthesis by the frog interrenal gland.
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gonadotropin releasing hormone stimulates biosynthesis of prostaglandin f2α by the interrenal gland of the water frog Rana esculenta in vitro
General and Comparative Endocrinology, 1991Co-Authors: Anna Gobbetti, Massimo ZeraniAbstract:Abstract The present study was carried out to evaluate the in vitro effects of mammalian gonadotropin-releasing hormone (mGnRH) on the production of prostaglandin F2α(PGF2α) and sex steroids (progesterone, androgens, and 17β-estradiol) by the interrenal gland of male and female Rana esculenta during three different periods of the sexual annual cycle. In both sexes, mGnRH induced a significant increase in PGF2α in the incubation medium in all examined periods. Progesterone and androgens were undetectable, while 17β-estradiol was significantly increased by mGnRH in interrenals incubated during the postreproductive period in both sexes. These results suggest that R. esculenta interrenals could be a GnRH-dependent PGF2α-secreting tissue. In addition, the simultaneous increase in PGF2α and estradiol from postreproductive cultured interrenals support the notion that mGnRH-induced estradiol synthesis is mediated through PGF2α formation. This finding, taken to-gether with other previous studies, strongly suggests that the end of the breeding period in R. esculenta depends on GnRH-induced PGF2α-mediated enhancement of estradiol synthesis in a steroidogenetic organ (probably interrenals).
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effects of captivity stress on plasma steroid levels in the green frog Rana esculenta during the annual reproductive cycle
Comparative Biochemistry and Physiology Part A: Physiology, 1991Co-Authors: Massimo Zerani, Gilberto Mosconi, Fabrizia Amabili, Anna GobbettiAbstract:Abstract 1. 1. Androgen, 17β-estradiol and corticosterone levels were measured by RIA in plasma of Rana esculenta frogs sampled in the field and in the laboratory. 2. 2. Androgen and 17β-estradiol annual cycles of frogs sampled in the field mirrored those of animals sampled in the laboratory 24 hr after capture; on the contrary the absolute values were not similar. 3. 3. 17β-estradiol levels showed a peak 6 hr after capture in the pre-reproduction and reproduction periods. 4. 4. Corticosterone levels increased 72 hr after capture.
Ines Di Rosa - One of the best experts on this subject based on the ideXlab platform.
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Evidence of Batrachochytrium dendrobatidis Infection in Water Frogs of the Rana esculenta Complex in Central Italy
2014Co-Authors: Ines Di RosaAbstract:Abstract: Batrachochytrium dendrobatidis (phylum Chytridiomycota, order Chytridiales) is the causative organism of chytridiomycosis in amphibians, a disease associated with their population decline worldwide. In this work, we report a cutaneous infection in water frogs of the Rana esculenta complex in agricultural areas of Umbria, central Italy. Histological, immunohistochemical, ultrastructural, and molecular analyses demon-strated for the first time the presence of the Batrachochytrium dendrobatidis in this complex; to date, no association between the presence of chytrid fungal infection and mortality has been found, to our knowledge. However, the presence of Batrachochytrium dendrobatidis infection in the water frogs of the Rana esculenta complex is of concern because the frogs could act as a reservoir species and contribute to the decline of less resistant species. Key words: amphibians, Batrachochytrium dendrobatidis, Rana esculenta, agricultural area
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Evidence of Batrachochytrium dendrobatidis Infection in Water Frogs of the Rana esculenta Complex in Central Italy
Ecohealth, 2005Co-Authors: Francesca Simoncelli, Raffaele Dall’olio, D. Vagnetti, Rita Pascolini, Anna Fagotti, Ines Di RosaAbstract:Batrachochytrium dendrobatidis (phylum Chytridiomycota, order Chytridiales) is the causative organism of chytridiomycosis in amphibians, a disease associated with their population decline worldwide. In this work, we report a cutaneous infection in water frogs of the Rana esculenta complex in agricultural areas of Umbria, central Italy. Histological, immunohistochemical, ultrastructural, and molecular analyses demonstrated for the first time the presence of the Batrachochytrium dendrobatidis in this complex; to date, no association between the presence of chytrid fungal infection and mortality has been found, to our knowledge. However, the presence of Batrachochytrium dendrobatidis infection in the water frogs of the Rana esculenta complex is of concern because the frogs could act as a reservoir species and contribute to the decline of less resistant species.
Anna Gobbetti - One of the best experts on this subject based on the ideXlab platform.
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role of nitric oxide in gonadotropin releasing hormone dependent prostaglandin f2α synthesis by frog Rana esculenta interrenal gland during post reproduction
Prostaglandins & Other Lipid Mediators, 1998Co-Authors: Anna Gobbetti, L Bellinicardellini, Massimo ZeraniAbstract:Abstract The aim of this study was to clarify the possible involvement of nitric oxide (NO) on prostaglandin (PG) E2-9-ketoreductase activity in the gonadotropin-releasing hormone (GnRH)-dependent PGF2α synthesis by the interrenal gland of the female water frog, Rana esculenta, during the post-reproduction. Interrenal glands were incubated in vitro with GnRH, NO donor (sodium nitroprusside, SNP), and inhibitors of phospholipase C (compound 48/80), inositol triphosphate (decavanadate), calmodulin (calmidazolium), NO synthase ( L -NAME), and PGE2-9-ketoreductase (palmitic acid). Production of PGE2 and PGF2α and NO synthase and PGE2-9-ketoreductase activities were determined. GnRH and SNP increased PGF2α production and PGE2-9-ketoreductase activity, and decreased production of PGE2 and GnRH increased NO synthase activity. GnRH effects were blocked by all inhibitors, except for palmitic acid, which did not affect NO synthase activity, which is increased by GnRH. This study indicates that NO may be involved in regulation of the R. esculenta post-reproduction through stimulation of PGE2-9-ketoreductase activity in GnRH-dependent PGF2α synthesis by the frog interrenal gland.
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gonadotropin releasing hormone stimulates biosynthesis of prostaglandin f2α by the interrenal gland of the water frog Rana esculenta in vitro
General and Comparative Endocrinology, 1991Co-Authors: Anna Gobbetti, Massimo ZeraniAbstract:Abstract The present study was carried out to evaluate the in vitro effects of mammalian gonadotropin-releasing hormone (mGnRH) on the production of prostaglandin F2α(PGF2α) and sex steroids (progesterone, androgens, and 17β-estradiol) by the interrenal gland of male and female Rana esculenta during three different periods of the sexual annual cycle. In both sexes, mGnRH induced a significant increase in PGF2α in the incubation medium in all examined periods. Progesterone and androgens were undetectable, while 17β-estradiol was significantly increased by mGnRH in interrenals incubated during the postreproductive period in both sexes. These results suggest that R. esculenta interrenals could be a GnRH-dependent PGF2α-secreting tissue. In addition, the simultaneous increase in PGF2α and estradiol from postreproductive cultured interrenals support the notion that mGnRH-induced estradiol synthesis is mediated through PGF2α formation. This finding, taken to-gether with other previous studies, strongly suggests that the end of the breeding period in R. esculenta depends on GnRH-induced PGF2α-mediated enhancement of estradiol synthesis in a steroidogenetic organ (probably interrenals).
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effects of captivity stress on plasma steroid levels in the green frog Rana esculenta during the annual reproductive cycle
Comparative Biochemistry and Physiology Part A: Physiology, 1991Co-Authors: Massimo Zerani, Gilberto Mosconi, Fabrizia Amabili, Anna GobbettiAbstract:Abstract 1. 1. Androgen, 17β-estradiol and corticosterone levels were measured by RIA in plasma of Rana esculenta frogs sampled in the field and in the laboratory. 2. 2. Androgen and 17β-estradiol annual cycles of frogs sampled in the field mirrored those of animals sampled in the laboratory 24 hr after capture; on the contrary the absolute values were not similar. 3. 3. 17β-estradiol levels showed a peak 6 hr after capture in the pre-reproduction and reproduction periods. 4. 4. Corticosterone levels increased 72 hr after capture.
Maurizio Simmaco - One of the best experts on this subject based on the ideXlab platform.
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functional characterisation of the 1 18 fragment of esculentin 1b an antimicrobial peptide from Rana esculenta
Peptides, 2003Co-Authors: Luisa M Mangoni, Donatella Barra, Giuseppina Mignogna, Daniela Fiocco, Maurizio SimmacoAbstract:Esculentin-1 is a 46-amino acid residue peptide isolated from skin secretions of Rana esculenta, displaying the most potent antimicrobial activity among the bioactive molecules found in the secretion, with negligible effects on eukaryotic cell membranes. From skin secretions, the 19-46 fragment of esculentin-1, devoid of antibacterial activity, was also isolated. We studied in detail the activity of the N-terminal fragment (1-18) of esculentin-1 using a synthetic amidated analogue. The results show that this fragment is highly active against most bacterial and fungal species, although at a lower extent than the full-length peptide, being four-fold more potent against Phytophthora nicotianae. It has a reduced activity against human erythrocytes with respect to the full-length peptide. The killing curves in liquid medium are similar for the two molecules and the shorter peptide is able to increase the bacterial outer and inner membrane permeability. Overall these data indicate that the antimicrobial properties of esculentin-1 are exerted by its N-terminal 1-18 region and that the positively charged residue distribution as well as peptide length represent important determinants for cell selectivity.
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The synthesis of antimicrobial peptides in the skin of Rana esculenta is stimulated by microorganisms.
The FASEB Journal, 2001Co-Authors: Maria Luisa Mangoni, Tindaro G. Renda, Donatella Barra, Rossella Miele, Maurizio SimmacoAbstract:SPECIFIC AIMIn the present study, we investigated the synthesis of antimicrobial peptides in skin glands of the frog Rana esculenta under different conditions. We show by HPLC analysis, detection of antimicrobial activity, and gland morphology that frogs kept in a sterile environment do not synthesize these peptides; their synthesis is induced by the presence of microorganisms.PRINCIPAL FINDINGS1. Induction of peptide synthesis by microorganismsTo study the synthesis of antimicrobial peptides in vivo, specimens of R. esculenta were repeatedly stimulated to deplete skin glands. Frogs were then exposed to different environmental conditions. A first group was kept in water in the presence of bacteria of the natural flora at 106 cfu/ml, and a second group was maintained for the same amount of time in water containing tetracycline and erythromycin at a final concentration of 80 and 150 μg/ml, respectively. After 1 and 2 wk, the antimicrobial activity, expressed as cecropin A units, as well as the reversed-phas...
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novel antimicrobial peptides from skin secretion of the european frog Rana esculenta
FEBS Letters, 1993Co-Authors: Maurizio Simmaco, Giuseppina Mignogna, Donatella Barra, Francesco BossaAbstract:Three antimicrobial peptides were isolated from skin secretion of the European frog, Rana esculenta. Two of them show similarity to brevinin-1 and brevinin-2, respectively, two antimicrobial peptides recently isolated from a Japanese frog [Morikawa, N., Hagiwara, K. and Nakajima, T. (1992) Biochem. Biophys. Res. Commun. 189, 184-190]. The third one, named esculentin, is 46 residues long and represents a different type of peptide. All these peptides have as a common motif an intramolecular disulfide bridge located at the COOH-terminal end. The peptides from R. esculenta show distinctive antibacterial activity against representative Gram-negative and Gram-positive bacterial species. In particular, esculentin is the most active against Staphylococcus aureus, and has a much lower hemolytic activity.