The Experts below are selected from a list of 165 Experts worldwide ranked by ideXlab platform
Adrian R Pierotti - One of the best experts on this subject based on the ideXlab platform.
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thimet oligopeptidase expression is differentially regulated in neuroendocrine and spermatid cell lines by transcription factor binding to sry sex determining region y caat and creb camp response element binding protein promoter consensus sequences
Biochemical Journal, 2003Co-Authors: Lesley S Morrison, Adrian R PierottiAbstract:The zinc metalloprotease thimet oligopeptidase (EP24.15) is found predominantly in the neuroendocrine-gonadal axis where it is implicated in the processing of bioactive peptides, including GnRH (gonadotropin-releasing hormone), beta-Neoendorphin, alpha-Neoendorphin and dynorphin(1-8), the progression of spermatogenesis and the normal clearance of beta-amyloid in brain cells. Regulation of the enzyme's activity may occur in part by phosphorylation and redox disruption of intermolecular disulphide bridges. The elevated levels of both EP24.15 activity and mRNA within testicular and neuroendocrine tissues indicate that EP24.15 gene expression is differentially regulated. In the present paper, we present a detailed analysis of the rat EP24.15 promoter region previously isolated and partially characterized in this laboratory. Employing site-directed mutagenesis to create a series of promoter deletions and full-length promoter mutants, and measuring their activity in luciferase reporter gene and electrophoretic mobility-shift assays, we have shown that the transcription of the EP24.15 gene is differentially regulated in neuroendocrine and spermatid cell lines by transcription factor binding to SRY (sex-determining region Y), CAAT and CREB (cAMP-response-element-binding protein) promoter consensus sequences. The key to identifying the in vivo role of thimet oligopeptidase is likely to be found within the mechanisms by which it is regulated, and it is therefore of particular significance that EP24.15 expression is regulated by SRY and CREB/CREM (cAMP-response element modulator), the principle testes-determining protein and the major orchestrator of spermatogenesis respectively.
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Thimet oligopeptidase expression is differentially regulated in neuroendocrine and spermatid cell lines by transcription factor binding to SRY (sex-determining region Y), CAAT and CREB (cAMP-response-element-binding protein) promoter consensus sequen
Biochemical Journal, 2003Co-Authors: Lesley S Morrison, Adrian R PierottiAbstract:The zinc metalloprotease thimet oligopeptidase (EP24.15) is found predominantly in the neuroendocrine–gonadal axis where it is implicated in the processing of bioactive peptides, including GnRH (gonadotropin-releasing hormone), β-Neoendorphin, α-Neoendorphin and dynorphin(1–8), the progression of spermatogenesis and the normal clearance of β-amyloid in brain cells. Regulation of the enzyme's activity may occur in part by phosphorylation and redox disruption of intermolecular disulphide bridges. The elevated levels of both EP24.15 activity and mRNA within testicular and neuroendocrine tissues indicate that EP24.15 gene expression is differentially regulated. In the present paper, we present a detailed analysis of the rat EP24.15 promoter region previously isolated and partially characterized in this laboratory. Employing site-directed mutagenesis to create a series of promoter deletions and full-length promoter mutants, and measuring their activity in luciferase reporter gene and electrophoretic mobility-shift assays, we have shown that the transcription of the EP24.15 gene is differentially regulated in neuroendocrine and spermatid cell lines by transcription factor binding to SRY (sex-determining region Y), CAAT and CREB (cAMP-response-element-binding protein) promoter consensus sequences. The key to identifying the in vivo role of thimet oligopeptidase is likely to be found within the mechanisms by which it is regulated, and it is therefore of particular significance that EP24.15 expression is regulated by SRY and CREB/CREM (cAMP-response element modulator), the principle testes-determining protein and the major orchestrator of spermatogenesis respectively.
Lesley S Morrison - One of the best experts on this subject based on the ideXlab platform.
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thimet oligopeptidase expression is differentially regulated in neuroendocrine and spermatid cell lines by transcription factor binding to sry sex determining region y caat and creb camp response element binding protein promoter consensus sequences
Biochemical Journal, 2003Co-Authors: Lesley S Morrison, Adrian R PierottiAbstract:The zinc metalloprotease thimet oligopeptidase (EP24.15) is found predominantly in the neuroendocrine-gonadal axis where it is implicated in the processing of bioactive peptides, including GnRH (gonadotropin-releasing hormone), beta-Neoendorphin, alpha-Neoendorphin and dynorphin(1-8), the progression of spermatogenesis and the normal clearance of beta-amyloid in brain cells. Regulation of the enzyme's activity may occur in part by phosphorylation and redox disruption of intermolecular disulphide bridges. The elevated levels of both EP24.15 activity and mRNA within testicular and neuroendocrine tissues indicate that EP24.15 gene expression is differentially regulated. In the present paper, we present a detailed analysis of the rat EP24.15 promoter region previously isolated and partially characterized in this laboratory. Employing site-directed mutagenesis to create a series of promoter deletions and full-length promoter mutants, and measuring their activity in luciferase reporter gene and electrophoretic mobility-shift assays, we have shown that the transcription of the EP24.15 gene is differentially regulated in neuroendocrine and spermatid cell lines by transcription factor binding to SRY (sex-determining region Y), CAAT and CREB (cAMP-response-element-binding protein) promoter consensus sequences. The key to identifying the in vivo role of thimet oligopeptidase is likely to be found within the mechanisms by which it is regulated, and it is therefore of particular significance that EP24.15 expression is regulated by SRY and CREB/CREM (cAMP-response element modulator), the principle testes-determining protein and the major orchestrator of spermatogenesis respectively.
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Thimet oligopeptidase expression is differentially regulated in neuroendocrine and spermatid cell lines by transcription factor binding to SRY (sex-determining region Y), CAAT and CREB (cAMP-response-element-binding protein) promoter consensus sequen
Biochemical Journal, 2003Co-Authors: Lesley S Morrison, Adrian R PierottiAbstract:The zinc metalloprotease thimet oligopeptidase (EP24.15) is found predominantly in the neuroendocrine–gonadal axis where it is implicated in the processing of bioactive peptides, including GnRH (gonadotropin-releasing hormone), β-Neoendorphin, α-Neoendorphin and dynorphin(1–8), the progression of spermatogenesis and the normal clearance of β-amyloid in brain cells. Regulation of the enzyme's activity may occur in part by phosphorylation and redox disruption of intermolecular disulphide bridges. The elevated levels of both EP24.15 activity and mRNA within testicular and neuroendocrine tissues indicate that EP24.15 gene expression is differentially regulated. In the present paper, we present a detailed analysis of the rat EP24.15 promoter region previously isolated and partially characterized in this laboratory. Employing site-directed mutagenesis to create a series of promoter deletions and full-length promoter mutants, and measuring their activity in luciferase reporter gene and electrophoretic mobility-shift assays, we have shown that the transcription of the EP24.15 gene is differentially regulated in neuroendocrine and spermatid cell lines by transcription factor binding to SRY (sex-determining region Y), CAAT and CREB (cAMP-response-element-binding protein) promoter consensus sequences. The key to identifying the in vivo role of thimet oligopeptidase is likely to be found within the mechanisms by which it is regulated, and it is therefore of particular significance that EP24.15 expression is regulated by SRY and CREB/CREM (cAMP-response element modulator), the principle testes-determining protein and the major orchestrator of spermatogenesis respectively.
Ryszard Przewlocki - One of the best experts on this subject based on the ideXlab platform.
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Effects of repeated psychostimulant administration on the prodynorphin system activity and kappa opioid receptor density in the rat brain
Neuroscience, 1998Co-Authors: J Turchan, Barbara Przewlocka, W. Lason, Ryszard PrzewlockiAbstract:Abstract The prodynorphin system is implicated in the neurochemical mechanism of psychostimulants. To elucidate the activity of the endogenous prodynorphin system upon treatment with psychostimulants, we investigated the effect of single and repeated cocaine and amphetamine on the prodynorphin messenger RNA level, the prodynorphin-derived peptide α-Neoendorphin tissue level, and its in vitro release in the nucleus accumbens and striatum of rats. The density of κ opioid receptors in those brain regions was also assessed. Rats were injected with cocaine following a “binge” administration pattern, 20 mg/kg i.p. every hour for 3 h, one (single treatment) or five days (chronic treatment). Amphetamine, 2.5 mg/kg i.p. was administered once (single treatment) or twice a day for five days (chronic treatment). As shown by an in situ hybridization study, the prodynorphin messenger RNA levels in the nucleus accumbens and striatum were raised following single (at 3 h) and chronic (at 3 and 24 h) cocaine administration. The prodynorphin messenger RNA level in the nucleus accumbens was markedly elevated after single or repeated amphetamine administration. A similar tendency was observed in the striatum. Acute cocaine and amphetamine administration had no effect on the α-Neoendorphin tissue level, whereas chronic administration of those drugs elevated the α-Neoendorphin level in the nucleus accumbens and striatum at the late time-points studied. Acute and repeated cocaine administration had no effect on α-Neoendorphin release in both the nucleus accumbens and striatum at 3 and 48 h after drug injection. In contrast, single and chronic (at 24 and 48 h) amphetamine administration profoundly elevated the release of α-Neoendorphin in both these structures. Addition of cocaine or amphetamine to the incubation medium (10 −5 –10 −6 M) decreased the basal release of α-Neoendorphin in the nucleus accumbens slices of naive rats, but it did not change the stimulated release (K + 57 mM). On the other hand, in the striatum slices, addition of cocaine to the incubation medium depressed basal and stimulated release of the peptide; no significant changes were observed after addition of amphetamine. Cocaine and amphetamine evoked profound and long-term down-regulation of the κ opioid receptors in both structures. The above data indicate that the amphetamine-induced changes were more abundant than those caused by cocaine; only treatment with amphetamine markedly enhanced the release of prodynorphin-derived peptide. Furthermore, the psychostimulant-induced enhancement of biosynthetic activity of prodynorphin neurons was correlated with a marked and persistent decrease in the κ opioid receptor density at a late withdrawal time.
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The effect of single and repeated morphine administration on the prodynorphin system activity in the nucleus accumbens and striatum of the rat.
Neuroscience, 1996Co-Authors: Barbara Przewlocka, J Turchan, W. Lason, Ryszard PrzewlockiAbstract:Pharmacological data indicate that prodynorphin peptides and exogenous kappa agonists affect opioid tolerance and dependence. In order to elucidate the activity of the endogenous prodynorphin system during opiate tolerance and dependence, we investigated the effect of single and repeated morphine administration on the alpha-Neoendorphin tissue level, its in vitro release, and the prodynorphin messenger RNA level in the nucleus accumbens and striatum of the rat. Acute and repeated morphine administration (14 days, increasing doses, 20-100 mg/kg, i.p.) increased the level of alpha-Neoendorphin in the nucleus accumbens after 3 h; a similar effect was observed at 24 and 48 h after the last chronic morphine injection. On the other hand, the basal and stimulated (K+, 57 mM) release of alpha-Neoendorphin from nucleus accumbens slices were significantly elevated only at 24 h after the last morphine injection. The prodynorphin messenger RNA hybridization signal in the nucleus accumbens was enhanced at 3 h after acute morphine injection, whereas repeated morphine administration decreased the messenger RNA level at that time point. Upon late chronic morphine withdrawal (at 24 and 48 h), the prodynorphin messenger RNA level in that tissue was significantly elevated. In the striatum, single morphine administration had no effect on the alpha-Neoendorphin tissue level, release of the peptide, and prodynorphin messenger RNA level. On the other hand, chronic injection of morphine elevated all those parameters. The tissue level of alpha-Neoendorphin was elevated at 3 h, and was back to normal at 24 and 48 h after the last drug injection. Both the basal and stimulated alpha-Neoendorphin release from striatal slices was significantly increased at all the time points studied. Repeated morphine administration elevated the striatal prodynorphin messenger RNA level at 24 and 48 h after the drug withdrawal. Addition of morphine to the incubation medium reduced the basal release of alpha-Neoendorphin in both the nucleus accumbens and striatal slices in naive animals, whereas the stimulated release was attenuated in the latter tissue only. The present study indicates that withdrawal of chronic morphine leads to enhancement of the prodynorphin neurons activity in the nucleus accumbens and striatum of the rat. It is suggested that these effects may participate in the mechanism of aversive reactions during withdrawal.
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Repeated ethanol administration decreases prodynorphin biosynthesis in the rat hippocampus.
Neuroscience letters, 1992Co-Authors: Barbara Przewlocka, W. Lason, Ryszard PrzewlockiAbstract:The effect of single and repeated (19 days) intragastric ethanol administration on prodynorphin mRNA and alpha-Neoendorphin levels in the hippocampus of the rat was studied using in situ hybridization and RIA methods, respectively. Single ethanol administration had no effect on either of these two parameters. Repeated ethanol administration decreased both immunoreactive (ir) alpha-Neoendorphin (by ca. 37%) and prodynorphin mRNA (by ca. 57%) levels. Two days after the last dose of ethanol no changes in the ir-alpha-Neoendorphin tissue content were found, whereas the level of prodynorphin mRNA remained decreased (by ca. 44%). These results suggest that repeated ethanol evokes a long-lasting decrease in the biosynthesis of hippocampal prodynorphin, this effect that may play some role in the ethanol-induced deficiency of neuronal functions.
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The prodynorphin system in the rat hippocampus is differentially influenced by kainic acid and pentetrazole.
Neuroscience, 1992Co-Authors: W. Lason, Barbara Przewlocka, Ryszard PrzewlockiAbstract:Administration of kainic acid (15 mg/kg, i.p.) or pentetrazole (75 mg/kg, i.p.) to rats evoked recurrent limbic or tonic-clonic seizures, respectively. Radioimmunoassay showed that the level of alpha-Neoendorphin (prodynorphin-derived peptide) in the hippocampus was decreased after 3 h (by c. 60%) and 72 h (by c. 40%), but was not changed after 24 h following kainic acid administration. The basal release of alpha-Neoendorphin from hippocampal slices of kainic acid-treated rats was decreased after 3, 24 and 72 h following the drug injection by c. 50%. The K(+)-stimulated release was decreased after 3 and 24 h (by c. 300 and 200%, respectively) and was back to the control level after 72 h. An in situ hybridization study showed that kainic acid strongly enhanced the prodynorphin messenger RNA levels in the dentate gyrus after 3 and 24 h (by c. 200%), whereas after 72 h it tended to decrease. Twenty four hours after pentetrazole injection the hippocampal level of alpha-Neoendorphin was elevated (by c. 33%) and remained unchanged after 3 and 72 h. No significant changes in the basal or K(+)-stimulated alpha-Neoendorphin release from hippocampal slices of pentetrazole-treated rats were found at any time points measured. Three and 24 h after pentetrazole administration the level of prodynorphin mRNA in the dentate gyrus was slightly decreased (by c. 30%), but was back to the control values after 72 h. Hence seizure-related changes in hippocampal prodynorphin neuron activity seem to depend on the experimental model of epilepsy.(ABSTRACT TRUNCATED AT 250 WORDS)
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Time-dependent changes in the activity of opioid systems in the spinal cord of monoarthritic rats--a release and in situ hybridization study.
Neuroscience, 1992Co-Authors: Barbara Przewlocka, W. Lason, Ryszard PrzewlockiAbstract:The activity of the endogenous opioid systems was analysed in the spinal cord of rats 12 h, one, five or 14 days after injection of the Freund Adjuvant into the hind limb sole. The tissue level of immunoreactive Met-enkephalin-Arg6-Gly7-Leu8, a peptide derived from proenkephalin, started to rise 12 h after Freund Adjuvant inoculation and remained enhanced until day 14. The spontaneous release of the immunoreactive Met-enkephalin-Arg6-Gly7-Leu8 was also elevated at all the examined time points, the peak occurring on day 1. No changes were observed in the stimulated release except on day 14, when the peptide release was decreased. The proenkephalin messenger RNA level was enhanced at all the time points on the ipsilateral side of the spinal cord in laminae I-II, whereas in lamina V an increase was observed only on days 1 and 5. An increase in the proenkephalin messenger RNA level on the contralateral side was observed only in laminae I-II and only on days 1 and 5. The tissue level of immunoreactive alpha-Neoendorphin, a peptide derived from prodynorphin, was significantly increased on days 5 and 14. The spontaneous immunoreactive alpha-Neoendorphin release from spinal cord slices was elevated at all the time points studied, whereas the stimulated release of the peptide was strongly increased 12 h after Freund Adjuvant inoculation but gradually declined on the following days. An in situ hybridization study showed that the prodynorphin messenger RNA level in laminae I-II was increased at all the examined time points.(ABSTRACT TRUNCATED AT 250 WORDS)
Wolfgang Kummer - One of the best experts on this subject based on the ideXlab platform.
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sympathetic noradrenergic fibers as the source of immunoreactive alpha Neoendorphin and dynorphin in the guinea pig heart
Cells Tissues Organs, 1994Co-Authors: Konrad Wegener, Wolfgang KummerAbstract:Dynorphin and α-Neoendorphin bind to the K subtype of opioid receptors and have been shown to inhibit the release of noradrenaline from cardiac sympathetic axons. The purpose of this study was to eluc
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Sympathetic Noradrenergic Fibers as the Source of Immunoreactive Alpha-Neoendorphin and Dynorphin in the Guinea Pig Heart
Acta anatomica, 1994Co-Authors: Konrad Wegener, Wolfgang KummerAbstract:Dynorphin and alpha-Neoendorphin bind to the kappa subtype of opioid receptors and have been shown to inhibit the release of noradrenaline from cardiac sympathetic axons. The purpose of this study was to elucidate the endogenous localization of dynorphin and alpha-Neoendorphin in the guinea pig heart. This goal was achieved by double- and triple-labelling immunofluorescence. Dynorphin- and alpha-Neoendorphin-immunoreactive nerve fibers were numerous around coronary blood vessels and among cardiomyocytes. They also contained immunoreactivities to the rate-limiting enzyme of catecholamine synthesis tyrosine hydroxylase and to neuropeptide Y. These fibers disappeared in response to chemical sympathectomy (6-hydroxydopamine treatment). In contrast, substance P/calcitonin gene-related peptide-immunoreactive axons of sensory origin did not contain dynorphin and alpha-Neoendorphin immunoreactivities and were unaffected by chemical sympathectomy. The findings demonstrate that immunoreactive dynorphin and alpha-Neoendorphin are contained in postganglionic sympathetic nerve fibers innervating coronary blood vessels and cardiac muscle. Therefore, the inhibitory effect of these peptides upon noradrenaline release from the sympathetic terminal may well be an autoinhibitory feedback loop.
Shigeki Tsuchida - One of the best experts on this subject based on the ideXlab platform.
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Kinetic evaluation of β-Neoendorphin hydrolysis by the somatic and testicular isozymes of human angiotensin-converting enzyme
Biochimica et biophysica acta, 1997Co-Authors: Makoto Hayakari, Kimihiko Satoh, Keizou Ookawa, Hiroko Kano, Satoshi Murakami, Noriaki Ikeda, Shigeki TsuchidaAbstract:Angiotensin-converting enzyme (ACE) has both somatic and testicular isozymes, the former possessing two catalytically active domains, amino-terminal and carboxyl-terminal, while the latter has only the carboxyl-terminal one. We compared hydrolysis processes of the nonapeptide beta-Neoendorphin by the two isozymes of human ACE. Both isozymes hydrolyzed the peptide to Tyr1-Gly2-Gly3 by the sequential removal of carboxyl-terminal dipeptides in three consecutive steps. The rate constant values for the second step, conversion of beta-Neoendorphin1-7 to Leu-enkephalin, by the somatic isozyme in the presence of 10 or 200 mM NaCl were 4-fold higher than those for the first step, conversion of beta-Neoendorphin1-9 to beta-Neoendorphin1-7. The k(cat) values of the somatic isozyme for beta-Neoendorphin1-7 were 2-fold higher than those for beta-Neoendorphin1-9, indicating that beta-Neoendorphin1-7 is more rapidly hydrolyzed than beta-Neoendorphin1-9. The rate constant value for the second step at 10 mM NaCl was 5-fold higher than that for the testicular isozyme. Similar extent of difference was also observed in k(cat) values for beta-Neoendorphin1-7 between the two isozymes. These results suggest that the amino-terminal domain of the somatic isozyme mainly contributes to the conversion of beta-Neoendorphin1-7 to Leu-enkephalin at a low NaCl concentration. Optimal chloride concentrations for the individual steps of beta-Neoendorphin1-9 hydrolysis differed between the two isozymes.
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kinetic evaluation of β Neoendorphin hydrolysis by the somatic and testicular isozymes of human angiotensin converting enzyme
Biochimica et Biophysica Acta, 1997Co-Authors: Makoto Hayakari, Kimihiko Satoh, Keizou Ookawa, Hiroko Kano, Satoshi Murakami, Noriaki Ikeda, Shigeki TsuchidaAbstract:Abstract Angiotensin-converting enzyme (ACE) has both somatic and testicular isozymes, the former possessing two catalytically active domains, amino-terminal and carboxyl-terminal, while the latter has only the carboxyl-terminal one. We compared hydrolysis processes of the nonapeptide β -Neoendorphin by the two isozymes of human ACE. Both isozymes hydrolyzed the peptide to Tyr 1 -Gly 2 -Gly 3 by the sequential removal of carboxyl-terminal dipeptides in three consecutive steps. The rate constant values for the second step, conversion of β -Neoendorphin 1–7 to Leu-enkephalin, by the somatic isozyme in the presence of 10 or 200 mM NaCl were 4-fold higher than those for the first step, conversion of β -Neoendorphin 1–9 to β -Neoendorphin 1–7 . The k cat values of the somatic isozyme for β -Neoendorphin 1–7 were 2-fold higher than those for β -Neoendorphin 1–9 , indicating that β -Neoendorphin 1–7 is more rapidly hydrolyzed than β -Neoendorphin 1–9 . The rate constant value for the second step at 10 mM NaCl was 5-fold higher than that for the testicular isozyme. Similar extent of difference was also observed in k cat values for β -Neoendorphin 1–7 between the two isozymes. These results suggest that the amino-terminal domain of the somatic isozyme mainly contributes to the conversion of β -Neoendorphin 1–7 to Leu-enkephalin at a low NaCl concentration. Optimal chloride concentrations for the individual steps of β -Neoendorphin 1–9 hydrolysis differed between the two isozymes.
