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Sample records for beta hydroxylase activity

  1. Genotype-independent decrease in plasma dopamine beta-hydroxylase activity in Alzheimer’s disease

    Science.gov (United States)

    Mustapic, Maja; Presecki, Paola; Pivac, Nela; Mimica, Ninoslav; Hof, Patrick R.; Simic, Goran; Folnegovic-Smalc, Vera; Muck-Seler, Dorotea

    2014-01-01

    The noradrenergic system is involved in the etiology and progression of Alzheimer’s disease (AD) but its role is still unclear. Dopamine beta-hydroxylase (DBH) as a catecholamine-synthesizing enzyme plays a central role in noradrenaline (NA) synthesis and turnover. Plasma DBH (pDBH) activity shows wide inheritable interindividual variability that is under genetic control. The aim of this study was to determine pDBH activity, DBH (C-970T; rs1611115) and DBH (C1603T; rs6271) gene polymorphisms in 207 patients with AD and in 90 healthy age-matched controls. Plasma DBH activity was lower, particularly in the early stage of AD, compared to values in middle and late stages of the disease, as well as to control values. Two-way ANOVA revealed significant effect of both diagnosis and DBH (C-970T) or DBH (C1603T) genotypes on pDBH activity, but without significant diagnosis×genotype interaction. No association was found between AD and DBH C-970T (OR=1.08, 95% CI 1.13–4.37; p=0.779) and C1603T (OR=0.89; 95% CI 0.36–2.20; p=0.814) genotypes controlled for age, gender, and ApoE4 allele. The decrease in pDBH activity, found in early phase of AD suggests that alterations in DBH activity represent a compensatory mechanism for the loss of noradrenergic neurons, and that treatment with selective NA reuptake inhibitors may be indicated in early stages of AD to compensate for loss of noradrenergic activity in the locus coeruleus. PMID:23416088

  2. Dopamine beta-hydroxylase deficiency

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    Senard Jean-Michel

    2006-03-01

    Full Text Available Abstract Dopamine beta-hydroxylase (DβH deficiency is a very rare form of primary autonomic failure characterized by a complete absence of noradrenaline and adrenaline in plasma together with increased dopamine plasma levels. The prevalence of DβH deficiency is unknown. Only a limited number of cases with this disease have been reported. DβH deficiency is mainly characterized by cardiovascular disorders and severe orthostatic hypotension. First symptoms often start during a complicated perinatal period with hypotension, muscle hypotonia, hypothermia and hypoglycemia. Children with DβH deficiency exhibit reduced ability to exercise because of blood pressure inadaptation with exertion and syncope. Symptoms usually worsen progressively during late adolescence and early adulthood with severe orthostatic hypotension, eyelid ptosis, nasal stuffiness and sexual disorders. Limitation in standing tolerance, limited ability to exercise and traumatic morbidity related to falls and syncope may represent later evolution. The syndrome is caused by heterogeneous molecular alterations of the DBH gene and is inherited in an autosomal recessive manner. Restoration of plasma noradrenaline to the normal range can be achieved by therapy with the synthetic precursor of noradrenaline, L-threo-dihydroxyphenylserine (DOPS. Oral administration of 100 to 500 mg DOPS, twice or three times daily, increases blood pressure and reverses the orthostatic intolerance.

  3. Genetics Home Reference: congenital adrenal hyperplasia due to 11-beta-hydroxylase deficiency

    Science.gov (United States)

    ... due to 11-beta-hydroxylase deficiency congenital adrenal hyperplasia due to 11-beta-hydroxylase deficiency Enable Javascript ... PDF Open All Close All Description Congenital adrenal hyperplasia (CAH) due to 11-beta-hydroxylase deficiency is ...

  4. Plasma Dopamine-Beta-Hydroxylase as an Index of Peripheral Noradrenergic Activity

    Science.gov (United States)

    1981-08-17

    significant increase in NE after a 40-60% blood loss in dogs . Hemoconcentration is 34 a possible explanation. A sustained and controlled hypotension...was not maintained, and the rise in plasma enzyme activity did not reach levels signif icantly dif ferent from control values (200). In another dog ...change. 45 Decreased plasma DBH levels appear in patients with autism , and patients treated for acute alcoholism had enzyme activities essentially

  5. Construction of a tissue engineered intervertebral disc with high biological activity using an allogeneic intervertebral disc supplemented with transfected nucleus pulposus cells expressing exogenous dopamine beta-hydroxylase.

    Science.gov (United States)

    Bai, M; Wang, Y H; Yin, H P; Li, S W

    2015-09-09

    This study addressed the in vitro construction and biological activity of tissue engineered intervertebral discs with exogenous human dopamine beta-hydroxylase (DBH) nucleus pulposus cells. pSNAV2.0-DBH expression plasmids were utilized to enhance the survival rates of intervertebral disc tissue cells. Various concentrations of transfected nucleus pulposus cells were injected into the discs, and DBH mRNA expression was determined using polymerase chain reaction amplification. Polysaccharide content and total collagen protein content in the engineered disc nucleus pulposus tissue were determined. The visible fluorescence intensities of the 1 x 10(5) and 1 x 10(6) groups vs the 1 x 10(4) group were significantly increased (P 0.05) at 7 days after injection. DBH mRNA expression could be detected in the all but the EGFP control group at 14 days culture. No significant difference was observed in the protein content between the 1 x 10(4) and the control groups at various times, while the protein content was significantly higher in the 1 x 10(5) vs the control and the 1 x 10(4) groups at 7-, 14-, and 21-day cultures. These results demonstrate that a tissue engineered intervertebral disc with high biological activity can be constructed by utilizing allogeneic intervertebral discs stored in liquid nitrogen and a 1 x 10(5) transfected nucleus pulposus cell complex with in vitro culture for 14 days. This model can be used in animal experiments to study the biological activity of the engineered discs.

  6. Silencing of beta-carotene hydroxylase increases total carotenoid and beta-carotene levels in potato tubers

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    Pizzichini Daniele

    2007-03-01

    Full Text Available Abstract Background Beta-carotene is the main dietary precursor of vitamin A. Potato tubers contain low levels of carotenoids, composed mainly of the xanthophylls lutein (in the beta-epsilon branch and violaxanthin (in the beta-beta branch. None of these carotenoids have provitamin A activity. We have previously shown that tuber-specific silencing of the first step in the epsilon-beta branch, LCY-e, redirects metabolic flux towards beta-beta carotenoids, increases total carotenoids up to 2.5-fold and beta-carotene up to 14-fold. Results In this work, we silenced the non-heme beta-carotene hydroxylases CHY1 and CHY2 in the tuber. Real Time RT-PCR measurements confirmed the tuber-specific silencing of both genes . CHY silenced tubers showed more dramatic changes in carotenoid content than LCY-e silenced tubers, with beta-carotene increasing up to 38-fold and total carotenoids up to 4.5-fold. These changes were accompanied by a decrease in the immediate product of beta-carotene hydroxylation, zeaxanthin, but not of the downstream xanthophylls, viola- and neoxanthin. Changes in endogenous gene expression were extensive and partially overlapping with those of LCY-e silenced tubers: CrtISO, LCY-b and ZEP were induced in both cases, indicating that they may respond to the balance between individual carotenoid species. Conclusion Together with epsilon-cyclization of lycopene, beta-carotene hydroxylation is another regulatory step in potato tuber carotenogenesis. The data are consistent with a prevalent role of CHY2, which is highly expressed in tubers, in the control of this step. Combination of different engineering strategies holds good promise for the manipulation of tuber carotenoid content.

  7. On the release of catecholamines and dopamine-beta-hydroxylase evoked by ouabain in the perfused cat adrenal gland.

    OpenAIRE

    Garcia, A. G.; Hernandez, M.; Horga, J. F.; Sanchez-Garcia, P.

    1980-01-01

    1 Secretion of catecholamines (CA) and dopamine-beta-hydroxylase (DBH) activity from the retrogradely perfused cat adrenal gland was studied following ouabain infusion. Perfusion with ouabain (10(-4) M) for 10 min caused a gradual release of CA in the effluent which reached its peak 30 min after the ouabain pulse, and was maintained constant for at least 1 h. The effect of ouabain seemed to be irreversible. 2 Mecamylamine, while blocking the CA secretory effects of acetylcholine (ACh) perfusi...

  8. Tetrahydrobiopterin shows chaperone activity for tyrosine hydroxylase.

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    Thöny, Beat; Calvo, Ana C; Scherer, Tanja; Svebak, Randi M; Haavik, Jan; Blau, Nenad; Martinez, Aurora

    2008-07-01

    Tyrosine hydroxylase (TH) is the rate-limiting enzyme in the synthesis of catecholamine neurotransmitters. Primary inherited defects in TH have been associated with l-DOPA responsive and non-responsive dystonia and infantile parkinsonism. In this study, we show that both the cofactor (6R)-l-erythro-5,6,7,8-tetrahydrobiopterin (BH(4)) and the feedback inhibitor and catecholamine product dopamine increase the kinetic stability of human TH isoform 1 in vitro. Activity measurements and synthesis of the enzyme by in vitro transcription-translation revealed a complex regulation by the cofactor including both enzyme inactivation and conformational stabilization. Oral BH(4) supplementation to mice increased TH activity and protein levels in brain extracts, while the Th-mRNA level was not affected. All together our results indicate that the molecular mechanisms for the stabilization are a primary folding-aid effect of BH(4) and a secondary effect by increased synthesis and binding of catecholamine ligands. Our results also establish that orally administered BH(4) crosses the blood-brain barrier and therapeutic regimes based on BH(4) supplementation should thus consider the effect on TH. Furthermore, BH(4) supplementation arises as a putative therapeutic agent in the treatment of brain disorders associated with TH misfolding, such as for the human TH isoform 1 mutation L205P.

  9. Purification of recombinant flavanone 3beta-hydroxylase from petunia hybrida and assignment of the primary site of proteolytic degradation.

    Science.gov (United States)

    Lukacin, R; Gröning, I; Schiltz, E; Britsch, L; Matern, U

    2000-03-15

    Flavanone 3beta-hydroxylase catalyzes the Fe(II)/oxoglutarate-dependent hydroxylation of (2S)-flavanones to (2R,3R)-dihydroflavonols in the course of flavonol/anthocyanin or catechin biosynthesis. The enzyme from Petunia hybrida consists of a 41,655-Da polypeptide that is prone to rapid proteolysis in crude plant extracts as well as on expression in Escherichia coli, and commercial protease inhibitors were inefficient in stopping the degradation. To pinpoint the primary site of proteolysis and to improve the activity yields, two revised schemes of purification were developed for the recombinant polypeptides. Applying a four-step protocol based on extraction and ion-exchange chromatography at pH 7.5, the primary, catalytically inactive proteolytic enzyme fragment (1.1 mg) was isolated and shown to cross-react on Western blotting as one homogeneous band of about 38 kDa. Mass spectrometric analysis assigned a mass of 37,820 +/- 100 Da to this fragment, and partial sequencing revealed an unblocked amino terminus identical to that of the native 3beta-hydroxylase. Thus, the native enzyme had been degraded by proteolysis of a small carboxy-terminal portion, and the primary site of cleavage must be assigned most likely to the Glu 337-Leu 338 bond, accounting for a loss of about 3800 Da. Alternatively, the enzyme degradation was greatly reduced when the extraction of recombinant bacteria was carried out with phosphate buffer at pH 5.5 followed by size exlusion and anion-exchange chromatography. This rapid, two-step purification resulted in a homogeneous 3beta-hydroxylase of high specific acitivity (about 32 mkat/kg) at roughly 5% yield, and the procedure is a major breakthrough in mechanistic investigations of this class of labile dioxygenases.

  10. Expression of gibberellin 3 beta-hydroxylase gene in a gravi-response mutant, weeping Japanese flowering cherry

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    Sugano, Mami; Nakagawa, Yuriko; Nyunoya, Hiroshi; Nakamura, Teruko

    2004-01-01

    Expressions of the gibberellin biosynthesis gene were investigated in a normal upright type and a gravi-response mutant, a weeping type of Japanese flowering cherry (Prunus spachiana), that is unable to support its own weight and elongates downward. A segment of the gibberellin 3 beta-hydroxylase cDNA of Prunus spachiana (Ps3ox), which is responsible for active gibberellin synthesis, was amplified by using real-time RT-PCR. The content of Ps3ox mRNA in the weeping type was much greater than that in the upright type, while the endogenous gibberellin level was much higher in the elongating zone of the weeping type. These results suggest that the amount and distribution of synthesized gibberellin regulate secondary xylem formation, and the unbalanced distribution of gibberellin affects the gravi-response of the Prunus tree.

  11. Molecular characterization of flavanone 3 beta-hydroxylases. Consensus sequence, comparison with related enzymes and the role of conserved histidine residues.

    Science.gov (United States)

    Britsch, L; Dedio, J; Saedler, H; Forkmann, G

    1993-10-15

    A heterologous cDNA probe from Petunia hybrida was used to isolate flavanone-3 beta-hydroxylase-encoding cDNA clones from carnation (Dianthus caryophyllus), china aster (Callistephus chinensis) and stock (Matthiola incana). The deduced protein sequences together with the known sequences of the enzyme from P. hybrida, barley (Hordeum vulgare) and snapdragon (Antirrhinum majus) enabled the determination of a consensus sequence which revealed an overall 84% similarity (53% identity) of flavanone 3 beta-hydroxylases from the different sources. Alignment with the sequences of other known enzymes of the same class and to related non-heme iron-(II) enzymes demonstrated the strict genetic conservation of 14 amino acids, in particular, of three histidines and an aspartic acid. The conservation of the histidine motifs provides strong support for the possible conservation of structurally similar iron-binding sites in these enzymes. The putative role of histidines as chelators of ferrous ions in the active site of flavanone 3 beta-hydroxylases was corroborated by diethyl-pyrocarbonate modification of the partially purified recombinant Petunia enzyme.

  12. Effects of embryonic and adult exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin on hepatic microsomal testosterone hydroxylase activities in great blue herons (Ardea herodias)

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    Sanderson, J.T.; Giesy, J.P. [Michigan State Univ., East Lansing, MI (United States); Janz, D.M.; Bellward, G.D. [Univ. of British Columbia, Vancouver, British Columbia (Canada)

    1997-06-01

    In a continuing effort to evaluate biomarkers of exposure of great blue herons (Ardea herodias) to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and related halogenated aromatic hydrocarbons, the authors examined the effect of TCDD on hepatic microsomal testosterone hydroxylase activities. Heron embryos were exposed in ovo to 2 {micro}g TCDD/kg egg (or corn oil vehicle) and sacrificed at hatch or 7 d posthatch. Adult herons were exposed intraperitoneally to 20 {micro}g TCDD/kg and sacrificed 2 weeks later. The sex of the birds was known for the adults only. Hepatic microsomes of herons of each age group were able to hydroxylate testosterone at the 2{beta}, 6{beta}, 15{alpha}, 16{alpha}, or 16{beta} positions. In 7-d-old chicks, an additional unidentified compound was formed. The age of the untreated herons had a strong influence on the activities of the five hydroxylases, with changes of up to 17-fold. The TCDD significantly induced 2{beta}-, 6{beta}, and 15{alpha}-testosterone hydroxylase activities in the adult females, 15{alpha} in the adult males, and 6{beta}-testosterone hydroxylase activity in the hatchlings. In the 7-d-old chicks, induction was no longer apparent. A significant correlation existed between hepatic microsomal ethoxyresorufin O-deethylase (EROD) and 6{beta}-testosterone hydroxylase activity in hatchlings and adult female herons. The TCDD-induced changes in testosterone hydroxylase activities occurred at doses that resulted in tissue concentrations and levels of EROD induction that were environmentally relevant, but did not result in overt toxicities.

  13. Molecular cloning of hyoscyamine 6 beta-hydroxylase, a 2-oxoglutarate-dependent dioxygenase, from cultured roots of Hyoscyamus niger.

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    Matsuda, J; Okabe, S; Hashimoto, T; Yamada, Y

    1991-05-25

    Roots of several solanaceous plants produce anticholinergic alkaloids, hyoscyamine and scopolamine. Hyoscyamine 6 beta-hydroxylase, a 2-oxoglutarate-dependent dioxygenase (EC 1.14.11.11), catalyzes hydroxylation of hyoscyamine in the biosynthetic pathway leading to scopolamine. We report here on the isolation of cDNA clones encoding the hydroxylase from a cDNA library made from mRNA of the cultured roots of Hyoscyamus niger. The library was screened with three synthetic oligonucleotides that encode amino acid sequences of internal peptide fragments of the purified hydroxylase. Nucleotide sequence analysis of the cloned cDNA revealed an open reading frame that encodes 344 amino acids (Mr = 38,999). All 12 internal peptide fragments determined in the purified enzyme were found in the amino acid sequence deduced from the cDNA. With computer-aided comparison to other proteins we found that the hydroxylase is homologous to two synthases involved in the biosynthesis of beta-lactam antibiotics in some microorganisms and the gene products of tomato pTOM13 cDNA and maize A2 locus which had been proposed to catalyze oxidative reactions in the biosynthesis of ethylene and anthocyan, respectively. RNA blotting hybridization showed that mRNA of the hydroxylase is abundant in cultured roots and present in plant roots, but absent in leaves, stems, and cultured cells of H. niger.

  14. Evolution of flavone synthase I from parsley flavanone 3beta-hydroxylase by site-directed mutagenesis.

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    Gebhardt, Yvonne Helen; Witte, Simone; Steuber, Holger; Matern, Ulrich; Martens, Stefan

    2007-07-01

    Flavanone 3beta-hydroxylase (FHT) and flavone synthase I (FNS I) are 2-oxoglutarate-dependent dioxygenases with 80% sequence identity, which catalyze distinct reactions in flavonoid biosynthesis. However, FNS I has been reported exclusively from a few Apiaceae species, whereas FHTs are more abundant. Domain-swapping experiments joining the N terminus of parsley (Petroselinum crispum) FHT with the C terminus of parsley FNS I and vice versa revealed that the C-terminal portion is not essential for FNS I activity. Sequence alignments identified 26 amino acid substitutions conserved in FHT versus FNS I genes. Homology modeling, based on the related anthocyanidin synthase structure, assigned seven of these amino acids (FHT/FNS I, M106T, I115T, V116I, I131F, D195E, V200I, L215V, and K216R) to the active site. Accordingly, FHT was modified by site-directed mutagenesis, creating mutants encoding from one to seven substitutions, which were expressed in yeast (Saccharomyces cerevisiae) for FNS I and FHT assays. The exchange I131F in combination with either M106T and D195E or L215V and K216R replacements was sufficient to confer some FNS I side activity. Introduction of all seven FNS I substitutions into the FHT sequence, however, caused a nearly complete change in enzyme activity from FHT to FNS I. Both FHT and FNS I were proposed to initially withdraw the beta-face-configured hydrogen from carbon-3 of the naringenin substrate. Our results suggest that the 7-fold substitution affects the orientation of the substrate in the active-site pocket such that this is followed by syn-elimination of hydrogen from carbon-2 (FNS I reaction) rather than the rebound hydroxylation of carbon-3 (FHT reaction).

  15. Mutations in the dopamine beta-hydroxylase gene are associated with human norepinephrine deficiency

    Science.gov (United States)

    Kim, Chun-Hyung; Zabetian, Cyrus P.; Cubells, Joseph F.; Cho, Sonhae; Biaggioni, Italo; Cohen, Bruce M.; Robertson, David; Kim, Kwang-Soo

    2002-01-01

    Norepinephrine (NE), a key neurotransmitter of the central and peripheral nervous systems, is synthesized by dopamine beta-hydroxylase (DBH) that catalyzes oxidation of dopamine (DA) to NE. NE deficiency is a congenital disorder of unknown etiology, in which affected patients suffer profound autonomic failure. Biochemical features of the syndrome include undetectable tissue and circulating levels of NE and epinephrine, elevated levels of DA, and undetectable levels of DBH. Here, we report identification of seven novel variants including four potentially pathogenic mutations in the human DBH gene (OMIM 223360) from analysis of two unrelated patients and their families. Both patients are compound heterozygotes for variants affecting expression of DBH protein. Each carries one copy of a T-->C transversion in the splice donor site of DBH intron 1, creating a premature stop codon. In patient 1, there is a missense mutation in DBH exon 2. Patient 2 carries missense mutations in exons 1 and 6 residing in cis. We propose that NE deficiency is an autosomal recessive disorder resulting from heterogeneous molecular lesions at DBH. Copyright 2002 Wiley-Liss, Inc.

  16. Gibberellin (GA) biosynthesis in elongating internodes Zea mays (maize): The 3. beta. -hydroxylase

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    Spray, C.R.; Phinney, B.O. (Univ. of California, Los Angeles (USA)); Gaskin, P.; MacMillan, J. (Univ. of Bristol (England))

    1989-04-01

    The early-13-hydroxylation pathway for GA biosynthesis in maize leads to GA{sub 1}, the main GA responsible for shoot elongation. Growth response data, double-labeled feeding studies and endogenous GA levels suggest that the dwarf-1 mutant blocks the step GA{sub 20}to GA{sub 1}. We are screening for a system from maize from which we can purify the 3{beta}-hydroxylase and study its physical and biological properties. We find that diced internodal tissues will metabolize ({sup 13}C, {sup 3}H)-GA{sub 20} to ({sup 13}C, {sup 3}H)-GA{sub 1} and ({sup 13}C, {sup 3}H)-GA{sub 29} with metabolism as high as 80%. A cell free system from this material will give 5% metabolism. In a typical experiment 1g of internodal tissue is frozen in liquid nitrogen and macerated in 0.1M Tris plus cofactors. The homogenate is centrifuged at 15000 x g for 30 min at 4{degrees}C and the supernatant used for metabolic studies.

  17. Dictyostelium phenylalanine hydroxylase is activated by its substrate phenylalanine.

    Science.gov (United States)

    Kim, Hye-Lim; Park, Mi-Bee; Kim, Yumin; Yang, Yun Gyeong; Lee, Soo-Woong; Zhuang, Ningning; Lee, Kon Ho; Park, Young Shik

    2012-10-19

    We have studied the regulatory function of Dictyostelium discoideum Ax2 phenylalanine hydroxylase (dicPAH) via characterization of domain structures. Including the full-length protein, partial proteins truncated in regulatory, tetramerization, or both, were prepared from Escherichia coli as his-tag proteins and examined for oligomeric status and catalytic parameters for phenylalanine. The proteins were also expressed extrachromosomally in the dicPAH knockout strain to examine their in vivo compatibility. The results suggest that phenylalanine activates dicPAH, which is functional in vivo as a tetramer, although cooperativity was not observed. In addition, the results of kinetic study suggest that the regulatory domain of dicPAH may play a role different from that of the domain in mammalian PAH.

  18. Behavioral responses of dopamine beta-hydroxylase knockout mice to modafinil suggest a dual noradrenergic-dopaminergic mechanism of action.

    Science.gov (United States)

    Mitchell, Heather A; Bogenpohl, James W; Liles, L Cameron; Epstein, Michael P; Bozyczko-Coyne, Donna; Williams, Michael; Weinshenker, David

    2008-12-01

    Modafinil is approved for use in the treatment of excessive daytime sleepiness. The precise mechanism of modafinil action has not been elucidated, although both dopamine (DA) and norepinephrine (NE) systems have been implicated. To explore the roles of DA and NE in the mechanism of modafinil-induced arousal, dopamine beta-hydroxylase knockout (Dbh -/-) mice were examined in behavioral paradigms of arousal (photobeam breaks and behavioral scoring of sleep latency). Dbh -/- mice completely lack NE but have hypersensitive DA signaling. It was hypothesized that Dbh -/- mice would be unresponsive to modafinil if the compound acts primarily via NE, but would be hypersensitive to modafinil if it acts primarily via DA. Dbh -/- mice had increased sensitivity to the locomotor-activating and wake-promoting effects of modafinil. Paradoxically, the alpha1-adrenergic receptor antagonist, prazosin, attenuated the effects of modafinil in control mice, but not in Dbh -/- mice. Blockade of DA receptors with flupenthixol decreased modafinil-induced locomotion and wake in both control and Dbh -/- mice. These results suggest that both NE and DA are involved in the behavioral effects of modafinil in control mice, but the requirement for NE can be bypassed by hypersensitive DA signaling.

  19. Positive association between--1021TT genotype of dopamine beta hydroxylase gene and progressive behavior of injection heroin users.

    Science.gov (United States)

    Xie, Xiaohu; Xu, Limin; Liu, Huifen; Chen, Weisheng; Zhuang, Dingding; Zhang, Jianbing; Duan, Shiwei; Zhou, Wenhua

    2013-04-29

    By balancing the ratios of dopamine and norepinephrine, dopamine beta hydroxylase (DBH) plays an important role in brain reward circuit that is involved with behavioral effects of heroin addiction. DBH -1021C/T (rs1611115) is a functional variant with strong correlation with plasma DBH activity and several nerval and psychic disorders. In the present study, we have collected 333 male cases with heroin addiction and 200 male healthy controls to explore the role of -1021C/T in heroin addiction. There is no evidence of association between -1021C/T and heroin addiction on both genotype and allele levels (P>0.05). In the injection subgroup of cases, -1021TT carriers have longer heroin addiction time (P<0.001) and higher dosage of self-administered heroin (P=0.045) than carriers with -1021CC or -1021CT, suggesting that patients with TT genotype are likely to have more progressive style of heroin users with injection route. In conclusion, our results support -1021TT genotype may be implicated with a more progressive nature of heroin addiction, although DBH -1021C/T is unlikely to be involved in the risk of heroin addiction.

  20. Human DJ-1-specific Transcriptional Activation of Tyrosine Hydroxylase Gene*

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    Ishikawa, Shizuma; Taira, Takahiro; Takahashi-Niki, Kazuko; Niki, Takeshi; Ariga, Hiroyoshi; Iguchi-Ariga, Sanae M. M.

    2010-01-01

    Loss-of-function mutation in the DJ-1 gene causes a subset of familial Parkinson disease. The mechanism underlying DJ-1-related selective vulnerability in the dopaminergic pathway is, however, not known. DJ-1 has multiple functions, including transcriptional regulation, and one of transcriptional target genes for DJ-1 is the tyrosine hydroxylase (TH) gene, the product of which is a key enzyme for dopamine biosynthesis. It has been reported that DJ-1 is a neuroprotective transcriptional co-activator that sequesters a transcriptional co-repressor polypyrimidine tract-binding protein-associated splicing factor (PSF) from the TH gene promoter. In this study, we found that knockdown of human DJ-1 by small interference RNA in human dopaminergic cell lines attenuated TH gene expression and 4-dihydroxy-l-phenylalanine production but that knockdown or knock-out of mouse DJ-1 in mouse cell lines or in mice did not affect such expression and TH activity. In reporter assays using the human TH gene promoter linked to the luciferase gene, stimulation of TH promoter activity was observed in human cells, but not mouse cells, that had been transfected with DJ-1. Although human DJ-1 and mouse DJ-1 were associated either with human or with mouse PSF, TH promoter activity inhibited by PSF was restored by human DJ-1 but not by mouse DJ-1. Chromatin immunoprecipitation assays revealed that the complex of PSF with DJ-1 bound to the human but not the mouse TH gene promoter. These results suggest a novel species-specific transcriptional regulation of the TH promoter by DJ-1 and one of the mechanisms for no reduction of TH in DJ-1-knock-out mice. PMID:20938049

  1. Comparative effects of indole and aminoacetonitrile derivatives on dimethylnitrosamine-demethylase and aryl hydrocarbon hydroxylase activities.

    Science.gov (United States)

    Arcos, J C; Myers, S C; Neuburger, B J; Argus, M F

    1980-04-01

    The effect of in vivo administration of indole and five 3-indolyl derivatives including L-tryptophan, as well as of aminoacetonitrile and 3 of its derivatives, were studied on the carcinogen-metabolizing hepatic mixed-function oxidases dimethylnitrosamine (DMN)-demethylase I and II and aryl hydrocarbon hydroxylase (AHH). Indole, 3-indolylmethanol, 3-indolyl-acetonitrile, 3-indolylacetone and L-tryptophan induce AHH activity from 3- to 6-fold of the control level, whereas beta-3-indolylethanol has no effect; the latter compound produces a 21% decrease of the endoplasmic reticulum content in the tissue. Only L-tryptophan induces DMN-demethylase I and only L-tryptophan and 3-indolylmethanol induce DMN-demethylase II, representing a doubling of enzyme activity in all 3 instances. Aminoacetonitrile is a potent repressor of DMN-demethylase I. Substitutions on the amino group bring about strong decrease or abolishment of mixed-function oxidase repressor activity; thus, iminodiacetonitrile has only about 1/5th the repressor activity of the parent compound, whereas nitrilotriacetonitrile and dimethylaminoacetonitrile appear to be inactive. Aminoacetonitrile and its derivatives studied have no effect on DMN-demethylase II and AHH activities. The mixed-function oxidase-modifying effects of the indole compounds and of aminoacetonitrile and its derivatives illustrate the potential complexity of effects of dietary constituents on the carcinogenic responses.

  2. Congenital adrenal hyperplasia due to 11-beta-hydroxylase deficiency: functional consequences of four CYP11B1 mutations

    Science.gov (United States)

    Menabò, Soara; Polat, Seher; Baldazzi, Lilia; Kulle, Alexandra E; Holterhus, Paul-Martin; Grötzinger, Joachim; Fanelli, Flaminia; Balsamo, Antonio; Riepe, Felix G

    2014-01-01

    Congenital adrenal hyperplasia (CAH) is one of the most common autosomal recessive inherited endocrine disease. Steroid 11β-hydroxylase deficiency (11β-OHD) is the second most common form of CAH. The aim of the study was to study the functional consequences of three novel and one previously described CYP11B1 gene mutations (p.(Arg143Trp), p.(Ala306Val), p.(Glu310Lys) and p.(Arg332Gln)) detected in patients suffering from classical and non-classical 11β-OHD. Functional analyses were performed by using a HEK293 cell in vitro expression system comparing wild type (WT) with mutant 11β-hydroxylase activity. Mutant proteins were examined in silico to study their effect on the three-dimensional structure of the protein. Two mutations (p.(Ala306Val) and p.(Glu310Lys)) detected in patients with classical 11β-OHD showed a nearly complete loss of 11β-hydroxylase activity. The mutations p.(Arg143Trp) and p.(Arg332Gln) detected in patients with non-classical 11β-OHD showed a partial functional impairment with approximately 8% and 6% of WT activity, respectively. Functional mutation analysis allows the classification of novel CYP11B1 mutations as causes of classical and non-classical 11β-OHD. The detection of patients with non-classical phenotypes underscores the importance to screen patients with a phenotype comparable to non-classical 21-hydroxylase deficiency for mutations in the CYP11B1 gene in case of a negative analysis of the CYP21A2 gene. As CYP11B1 mutations are most often individual for a family, the in vitro analysis of novel mutations is essential for clinical and genetic counselling. PMID:24022297

  3. Development of vitamin D/sub 3/ 25-hydroxylase activity in rat liver microsomes

    Energy Technology Data Exchange (ETDEWEB)

    Thierry-Palmer, M.; Cullins, S.; Rashada, S.; Gray, T.K.; Free, A.

    1986-05-01

    The authors have determined the ontogeny of vitamin D/sub 3/ 25-hydroxylase activity in rat liver microsomes. Microsomes from fetuses, neonates, and their mothers were incubated with 44 nM /sup 3/H-vitamin D/sub 3/ in the presence of an NADPH generating system, oxygen, KCl, and MgCl/sub 2/. Lipid extracts of the incubation samples were partially purified by thin-layer chromatography. Tritiated 25-hydroxy vitamin D/sub 3/ (250HD/sub 3/) was analyzed by high-pressure liquid chromatography using 94/6 hexane/isopropanol. Production rate for 250HD/sub 3/ in the mothers ranged from 0.22 to 0.30 pmol/mg protein/hr. Activities in the fetuses and neonates were 2.1, 12.9, 32.0, 35.8, and 71.0% of that of their mothers at -3, 0, 2, 7, and 15 days of age. The cytosolic fraction protected the substrate from degradation, stimulated the vitamin D/sub 3/ 25-hydroxylase reaction in neonates and mothers (1.4 to 1.7 fold increase), and was absolutely required for 25-hydroxylase activity in fetuses. These data suggest that microsomal vitamin D/sub 3/ 25-hydroxylase activity develops slowly and approaches full activity near the weaning stage. A cytosolic factor present as early as -3 days of age stimulates the activity of the microsomal vitamin D/sub 3/ 25-hydroxylase.

  4. A unique dual activity amino acid hydroxylase in Toxoplasma gondii.

    Directory of Open Access Journals (Sweden)

    Elizabeth A Gaskell

    Full Text Available The genome of the protozoan parasite Toxoplasma gondii was found to contain two genes encoding tyrosine hydroxylase; that produces L-DOPA. The encoded enzymes metabolize phenylalanine as well as tyrosine with substrate preference for tyrosine. Thus the enzymes catabolize phenylalanine to tyrosine and tyrosine to L-DOPA. The catalytic domain descriptive of this class of enzymes is conserved with the parasite enzyme and exhibits similar kinetic properties to metazoan tyrosine hydroxylases, but contains a unique N-terminal extension with a signal sequence motif. One of the genes, TgAaaH1, is constitutively expressed while the other gene, TgAaaH2, is induced during formation of the bradyzoites of the cyst stages of the life cycle. This is the first description of an aromatic amino acid hydroxylase in an apicomplexan parasite. Extensive searching of apicomplexan genome sequences revealed an ortholog in Neospora caninum but not in Eimeria, Cryptosporidium, Theileria, or Plasmodium. Possible role(s of these bi-functional enzymes during host infection are discussed.

  5. Concentration of dopamine in plasma, activity of dopamine beta-hydroxylase in serum and urinary excretion of free catecholamines and vanillylmandelic acid in women chronically exposed to carbon disulphide.

    Science.gov (United States)

    Stanosz, S; Kuligowski, D; Pieleszek, A; Zuk, E; Rzechuła, D; Chlubek, D

    1994-01-01

    The authors studied 140 women, selected at random, aged 22-55, divided into two groups. Group I (control) included 50 women, mean age 40.1 +/- 1.7 years. Group II included 90 women, mean age 39.7 +/- 2.1 years, chronically exposed to 15.6 - 21.84 mg/m3 of carbon disulphide from 0.5 to over 20 years. It was found that women chronically exposed to CS2 showed significantly lower levels of dopamine and lower activities of DBH (p vanillylmandelic acid.

  6. Influence of various phenolic compounds on phenol hydroxylase activity of a Trichosporon cutaneum strain.

    Science.gov (United States)

    Gerginova, Maria; Manasiev, Jordan; Shivarova, Nedka; Alexieva, Zlatka

    2007-01-01

    The phenol-degrading strain Trichosporon cutaneum R57 utilizes various aromatic and aliphatic compounds as a sole carbon and energy source. The intracellular activities of phenol hydroxylase [EC 1.14.13.7] of a Trichosporon cutaneum R57 strain grown on phenol (0.5 g/l) were measured. Different toxic phenol derivatives (cresols, nitrophenols and hydroxyphenols) were used as substrates in the reaction mixture for determination of the enzyme activity. The data obtained showed that the investigated enzyme was capable to hydroxylate all applied aromatic substrates. The measured activities of phenol hydroxylase varied significantly depending on the aromatic compounds used as substrates. The rate of phenol hydroxylase activity with phenol as a substrate (1.0 U/mg total cell protein) was accepted as 100%.

  7. Selective estrogen receptor-beta (SERM-beta) compounds modulate raphe nuclei tryptophan hydroxylase-1 (TPH-1) mRNA expression and cause antidepressant-like effects in the forced swim test.

    Science.gov (United States)

    Clark, J A; Alves, S; Gundlah, C; Rocha, B; Birzin, E T; Cai, S-J; Flick, R; Hayes, E; Ho, K; Warrier, S; Pai, L; Yudkovitz, J; Fleischer, R; Colwell, L; Li, S; Wilkinson, H; Schaeffer, J; Wilkening, R; Mattingly, E; Hammond, M; Rohrer, S P

    2012-11-01

    Estrogen acts through two molecularly distinct receptors termed estrogen receptor alpha (ERα) and estrogen receptor beta (ERβ) which bind estradiol with similar affinities and mediate the effects of estrogen throughout the body. ERα plays a major role in reproductive physiology and behavior, and mediates classic estrogen signaling in such tissues as the uterus, mammary gland, and skeleton. ERβ, however, modulates estrogen signaling in the ovary, the immune system, prostate, gastrointestinal tract, and hypothalamus, and there is some evidence that ERβ can regulate ERα activity. Moreover, ERβ knockout studies and receptor distribution analyses in the CNS suggest that this receptor may play a role in the modulation of mood and cognition. In recent years several ERβ-specific compounds (selective estrogen receptor beta modulators; SERM-beta) have become available, and research suggests potential utility of these compounds in menopausal symptom relief, breast cancer prevention, diseases that have an inflammatory component, osteoporosis, cardiovascular disease, and inflammatory bowel disease, as well as modulation of mood, and anxiety. Here we demonstrate an antidepressant-like effect obtained using two SERM-beta compounds, SERM-beta1 and SERM-beta2. These compounds exhibit full agonist activity at ERβ in a cell based estrogen response element (ERE) transactivation assay. SERM-beta1 and 2 are non-proliferative with respect to breast as determined using the MCF-7 breast cancer cell-based assay and non-proliferative in the uterus as determined by assessing the effects of SERM-beta compounds on immature rat uterine weight and murine uterine weight. In vivo SERM-beta1 and 2 are brain penetrant and display dose dependent efficacy in the murine dorsal raphe assays for induction of tryptophan hydroxylase mRNA and progesterone receptor protein. These compounds show activity in the murine forced swim test and promote hippocampal neurogenesis acutely in rats. Taken

  8. Development of adrenal zonation in fetal rats defined by expression of aldosterone synthase and 11beta-hydroxylase.

    Science.gov (United States)

    Wotus, C; Levay-Young, B K; Rogers, L M; Gomez-Sanchez, C E; Engeland, W C

    1998-10-01

    The adult rat adrenal cortex is comprised of three concentric steroidogenic zones that are morphologically and functionally distinguishable: the zona glomerulosa, zona intermedia, and the zona fasciculata/reticularis. Expression of the zone-specific steroidogenic enzymes, cytochrome P450 aldosterone synthase (P450aldo), and P450 11beta hydroxylase (P45011beta), produced by the zona glomerulosa and zona fasciculata/reticularis, respectively, can be used to define the adrenal cortical cell phenotype of these two zones. In this study, immunohistochemistry and in situ hybridization were used to determine the ontogeny of expression of P450aldo and P45011beta to monitor the pattern of development of the rat adrenal cortex. RIA was used to measure adrenal content of aldosterone and corticosterone, the resulting products of the two enzymatic pathways. Double immunofluorescent staining for both enzymes at gestational day 16 (E16) showed P45011beta protein expressed in cells distributed throughout most of the adrenal intermixed with a separate, but smaller, population of cells expressing P450aldo protein. Whereas expression of P45011beta protein retained a similar pattern of distribution from E16 to adulthood (ignoring distribution of SA-1 positive, presumptive medullary cells), P450aldo protein changed its pattern of distribution by E19, becoming localized in a discontinuous ring of cells adjacent to the capsule. By postnatal day 1, P450aldo protein distribution was similar to that observed in adult glands; P450aldo-positive cells formed a continuous zone underlying the capsule. In situ hybridization showed that the pattern of P45011beta messenger RNA expression paralleled protein expression at all times, whereas P450aldo messenger RNA paralleled protein at E19 and after, but was undetectable before E19. However, adrenal aldosterone and corticosterone, as measured by RIA, were detected by E16, supporting the functional capacity of both phenotypes for all ages studied. These

  9. Effects of disulfiram and dopamine beta-hydroxylase knockout on cocaine-induced seizures

    Science.gov (United States)

    Gaval-Cruz, Meriem; Schroeder, Jason P.; Liles, L. Cameron; Javors, Martin A.; Weinshenker, David

    2008-01-01

    The antialcoholism drug disulfiram has shown recent promise as a pharmacotherapy for treating cocaine dependence, probably via inhibition of dopamine β-hydroxylase (DBH), the enzyme that catalyzes the conversion of dopamine (DA) to norepinephrine (NE). We previously showed that DBH knockout (Dbh -/-) mice, which lack NE, are susceptible to seizures and are hypersensitive to the psychomotor, rewarding, and aversive effects of cocaine, suggesting that disulfiram might exacerbate cocaine-induced seizures (CIS) by inhibiting DBH. To test this, we examined CIS in wild-type and Dbh -/- mice following administration of disulfiram or the selective DBH inhibitor nepicastat. We found that Dbh genotype had no effect on CIS probability or frequency, whereas disulfiram, but not nepicastat, increased the probability of having CIS in both wild-type and Dbh -/- mice. Both disulfiram and nepicastat increased CIS frequency in wild-type but not Dbh -/- mice. There were no genotype or treatment effects on serum cocaine levels, except for an increase in disulfiram-treated Dbh -/- mice at the highest dose of cocaine. These results suggest that disulfiram enhances CIS via two distinct mechanisms: it both increases CIS frequency by inhibiting DBH and increases CIS frequency in a DBH-independent manner. PMID:18329701

  10. Stringency of the 2-His-1-Asp active-site motif in prolyl 4-hydroxylase.

    Directory of Open Access Journals (Sweden)

    Kelly L Gorres

    Full Text Available The non-heme iron(II dioxygenase family of enzymes contain a common 2-His-1-carboxylate iron-binding motif. These enzymes catalyze a wide variety of oxidative reactions, such as the hydroxylation of aliphatic C-H bonds. Prolyl 4-hydroxylase (P4H is an alpha-ketoglutarate-dependent iron(II dioxygenase that catalyzes the post-translational hydroxylation of proline residues in protocollagen strands, stabilizing the ensuing triple helix. Human P4H residues His412, Asp414, and His483 have been identified as an iron-coordinating 2-His-1-carboxylate motif. Enzymes that catalyze oxidative halogenation do so by a mechanism similar to that of P4H. These halogenases retain the active-site histidine residues, but the carboxylate ligand is replaced with a halide ion. We replaced Asp414 of P4H with alanine (to mimic the active site of a halogenase and with glycine. These substitutions do not, however, convert P4H into a halogenase. Moreover, the hydroxylase activity of D414A P4H cannot be rescued with small molecules. In addition, rearranging the two His and one Asp residues in the active site eliminates hydroxylase activity. Our results demonstrate a high stringency for the iron-binding residues in the P4H active site. We conclude that P4H, which catalyzes an especially demanding chemical transformation, is recalcitrant to change.

  11. A Preliminary Study of DBH (Encoding Dopamine Beta-Hydroxylase) Genetic Variation and Neural Correlates of Emotional and Motivational Processing in Individuals With and Without Pathological Gambling.

    Science.gov (United States)

    Yang, Bao-Zhu; Balodis, Iris M; Lacadie, Cheryl M; Xu, Jiansong; Potenza, Marc N

    2016-06-01

    Background and aims Corticostriatal-limbic neurocircuitry, emotional and motivational processing, dopaminergic and noradrenergic systems and genetic factors have all been implicated in pathological gambling (PG). However, allelic variants of genes influencing dopaminergic and noradrenergic neurotransmitters have not been investigated with respect to the neural correlates of emotional and motivational states in PG. Dopamine beta-hydroxylase (DBH) converts dopamine to norepinephrine; the T allele of a functional single-nucleotide polymorphism rs1611115 (C-1021T) in the DBH gene is associated with less DBH activity and has been linked to emotional processes and addiction. Here, we investigate the influence of rs1611115 on the neural correlates of emotional and motivational processing in PG and healthy comparison (HC) participants. Methods While undergoing functional magnetic resonance imaging, 18 PG and 25 HC participants, all European Americans, viewed gambling-, sad-, and cocaine-related videotapes. Analyses focused on brain activation differences related to DBH genotype (CC/T-carrier [i.e., CT and TT]) and condition (sad/gambling/cocaine). Results CC participants demonstrated greater recruitment of corticostriatal-limbic regions, relative to T-carriers. DBH variants were also associated with altered corticostriatal-limbic activations across the different videotape conditions, and this association appeared to be driven by greater activation in CC participants relative to T-carriers during the sad condition. CC relative to T-carrier subjects also reported greater subjective sadness to the sad videotapes. Conclusions Individual differences in genetic composition linked to aminergic function contribute significantly to emotional regulation across diagnostic groups and warrant further investigation in PG.

  12. Activation of phenylalanine hydroxylase by phenylalanine does not require binding in the active site.

    Science.gov (United States)

    Roberts, Kenneth M; Khan, Crystal A; Hinck, Cynthia S; Fitzpatrick, Paul F

    2014-12-16

    Phenylalanine hydroxylase (PheH), a liver enzyme that catalyzes the hydroxylation of excess phenylalanine in the diet to tyrosine, is activated by phenylalanine. The lack of activity at low levels of phenylalanine has been attributed to the N-terminus of the protein's regulatory domain acting as an inhibitory peptide by blocking substrate access to the active site. The location of the site at which phenylalanine binds to activate the enzyme is unknown, and both the active site in the catalytic domain and a separate site in the N-terminal regulatory domain have been proposed. Binding of catecholamines to the active-site iron was used to probe the accessibility of the active site. Removal of the regulatory domain increases the rate constants for association of several catecholamines with the wild-type enzyme by ∼2-fold. Binding of phenylalanine in the active site is effectively abolished by mutating the active-site residue Arg270 to lysine. The k(cat)/K(phe) value is down 10⁴ for the mutant enzyme, and the K(m) value for phenylalanine for the mutant enzyme is >0.5 M. Incubation of the R270K enzyme with phenylalanine also results in a 2-fold increase in the rate constants for catecholamine binding. The change in the tryptophan fluorescence emission spectrum seen in the wild-type enzyme upon activation by phenylalanine is also seen with the R270K mutant enzyme in the presence of phenylalanine. Both results establish that activation of PheH by phenylalanine does not require binding of the amino acid in the active site. This is consistent with a separate allosteric site, likely in the regulatory domain.

  13. Polypeptides having beta-glucosidase activity, beta-xylosidase activity, or beta-glucosidase and beta-xylosidase activity and polynucleotides encoding same

    Energy Technology Data Exchange (ETDEWEB)

    Morant, Marc

    2017-02-07

    The present invention relates to isolated polypeptides having beta-glucosidase activity, beta-xylosidase activity, or beta-glucosidase and beta-xylosidase activity and isolated polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides.

  14. Bifunctional activity of deoxyhypusine synthase/hydroxylase from Trichomonas vaginalis.

    Science.gov (United States)

    Quintas-Granados, Laura Itzel; Carvajal Gamez, Bertha Isabel; Villalpando, Jose Luis; Ortega-Lopez, Jaime; Arroyo, Rossana; Azuara-Liceaga, Elisa; Álvarez-Sánchez, María Elizbeth

    2016-04-01

    The Trichomonas vaginalis genome analysis suggested the presence of a putative deoxyhypusine synthase (TvDHS) that catalyzes the posttranslational modification of eIF-5A. Herein, we expressed and purified the recombinant TvDHS (rTvDHS) protein (43 kDa) and the recombinant TveIF-5A (rTveIF-5A) precursor protein (46 kDa). A 41 kDa band of the native TvDHS was recognized by western blot analysis in T. vaginalis total protein extract by a mouse polyclonal anti-rTvDHS antibody. The enzymatic activity of rTvDHS was determined by in vitro rTveIF-5A precursor modification. The modification reaction was performed by using ((3)H)-spermidine, and the biochemical analysis showed that rTvDHS exhibited Km value of 0.6 μM. The rTvDHS activity was inhibited by the spermidine analog, N″-guanyl-1,7-diamino-heptane (GC7). Native gel electrophoresis analysis showed two bands corresponding to an rTvDHS-rTveIF-5A complex and an intermediate form of rTveIF-5A. The two forms were subsequently separated by ion exchange chromatography to identify the hypusine residue by MS/MS analysis. Moreover, mutations in TvDHS showed that the putative HE motif present in this enzyme is involved in the hydroxylation of TveIF-5A. We observed that only hypusine-containing TveIF-5A was bound to an RNA hairpin ERE structure from the cox-2 gene, which contains the AAAUGUCACAC consensus sequence. Interestingly, 2DE-WB assays, using parasites that were grown in DAB-culture conditions and transferred to exogenous putrescine, showed the new isoform of TveIF-5A. In summary, our results indicate that T. vaginalis contains an active TvDHS capable of modifying the precursor TveIF-5A protein, which subsequently exhibits RNA binding activity.

  15. Differential regulation of chemoattractant-stimulated beta 2, beta 3, and beta 7 integrin activity.

    Science.gov (United States)

    Sadhu, C; Masinovsky, B; Staunton, D E

    1998-06-01

    Leukocyte adhesion to endothelium and extravasation are dynamic processes that require activation of integrins. Chemoattractants such as IL-8 and FMLP are potent activators of leukocyte integrins. To compare the chemoattractant-stimulated activation of three integrins, alpha 4 beta 7, alpha L beta 2, and alpha V beta 3, in the same cellular context, we expressed an IL-8 receptor (IL-8RA) and FMLP receptor (FPR) in the lymphoid cell line JY. Chemoattractants induced a rapid increase in alpha L beta 2- and alpha V beta 3-dependent JY adhesion within 5 min, and it was sustained for 30 min. In contrast, stimulation of alpha 4 beta 7-dependent adhesion was transient, returning to basal levels by 30 min. The activation profiles of the integrins were similar regardless of whether IL-8 or FMLP was used for induction. We also demonstrate that alpha 4 beta 7-dependent adhesion was uniquely responsive to the F actin-disrupting agent cytochalasin D and the protein kinase C (PKC) inhibitor chelerythrin. While alpha V beta 3- and alpha L beta 2-mediated cell adhesion was significantly reduced by cytochalasin D, alpha 4 beta 7-mediated adhesion was enhanced. Chelerythrin inhibited both the IL-8 and PMA activation of alpha L beta 2 and alpha V beta 3. In contrast, inducible alpha 4 beta 7 activity was unaffected, and basal activity was increased. These findings demonstrate that the mechanism of alpha 4 beta 7 regulation by chemoattractants is different from that of alpha L beta 2 and alpha V beta 3 and that it appears to involve distinct cytoskeletal and PKC dependencies. In addition, PKC activity may be a positive or negative regulator of integrin-dependent adhesion.

  16. Crystal structure of the ectoine hydroxylase, a snapshot of the active site.

    Science.gov (United States)

    Höppner, Astrid; Widderich, Nils; Lenders, Michael; Bremer, Erhard; Smits, Sander H J

    2014-10-24

    Ectoine and its derivative 5-hydroxyectoine are compatible solutes that are widely synthesized by bacteria to cope physiologically with osmotic stress. They also serve as chemical chaperones and maintain the functionality of macromolecules. 5-Hydroxyectoine is produced from ectoine through a stereo-specific hydroxylation, an enzymatic reaction catalyzed by the ectoine hydroxylase (EctD). The EctD protein is a member of the non-heme-containing iron(II) and 2-oxoglutarate-dependent dioxygenase superfamily and is evolutionarily well conserved. We studied the ectoine hydroxylase from the cold-adapted marine ultra-microbacterium Sphingopyxis alaskensis (Sa) and found that the purified SaEctD protein is a homodimer in solution. We determined the SaEctD crystal structure in its apo-form, complexed with the iron catalyst, and in a form that contained iron, the co-substrate 2-oxoglutarate, and the reaction product of EctD, 5-hydroxyectoine. The iron and 2-oxoglutarate ligands are bound within the EctD active site in a fashion similar to that found in other members of the dioxygenase superfamily. 5-Hydroxyectoine, however, is coordinated by EctD in manner different from that found in high affinity solute receptor proteins operating in conjunction with microbial import systems for ectoines. Our crystallographic analysis provides a detailed view into the active site of the ectoine hydroxylase and exposes an intricate network of interactions between the enzyme and its ligands that collectively ensure the hydroxylation of the ectoine substrate in a position- and stereo-specific manner.

  17. Intracellular ascorbate enhances hypoxia-inducible factor (HIF)-hydroxylase activity and preferentially suppresses the HIF-1 transcriptional response.

    Science.gov (United States)

    Kuiper, Caroline; Dachs, Gabi U; Currie, Margaret J; Vissers, Margreet C M

    2014-04-01

    Hypoxia-inducible factor (HIF)-1 drives the transcription of hundreds of genes to support cell survival under conditions of microenvironmental and metabolic stress. HIF-1 is downregulated by iron-containing 2-oxoglutarate-dependent enzymes that require ascorbate as a cofactor. The HIF hydroxylases control both protein stability and the formation of an active transcription complex and, consequently, ascorbate could affect HIF-1α stabilization and/or gene expression, but the relative effect of ascorbate on these separate processes has not been well characterized. In this study we examined the effects of known intracellular ascorbate concentrations on both processes in response to various means of hydroxylase inhibition, including CoCl2, NiCl2, desferrioxamine, dimethyloxalylglycine, and hypoxia. Ascorbate inhibited HIF-1 activity most dramatically with all mechanisms of iron competition. In addition, HIF-1-dependent gene expression was effectively prevented by ascorbate and was inhibited even under conditions that allowed HIF-1α protein stabilization. This suggests that (1) ascorbate acts primarily to stabilize and reduce the iron atom in the hydroxylase active site and (2) the asparagine hydroxylase controlling HIF-1 transcriptional activity is particularly susceptible to fluctuations in intracellular ascorbate. These findings suggest that ascorbate plays a significant role in supporting HIF-hydroxylase function and that it could thereby modulate the cell survival response.

  18. Effects of exposure to air pollution and smoking on the placental aryl hydrocarbon hydroxylase (AHH) activity

    Energy Technology Data Exchange (ETDEWEB)

    Hincal, F.

    Aryl hydrocarbon hydroxylase (AHH) activities were determined in placental tissues of 152 nonsmoker or exsmoker women who live in Ankara and 125 nonsmoker women who live in areas surrounding Ankara. Levels of AHH were also determined in the placentas of 52 cigarette smokers. The mean AHH activity in the Ankara group was 11.17 +/- 5.41; in the control group, 6.44 +/- 5.48; and for smokers, 45.68 +/- 53.36, which indicates significant differences (p < .001). There was a strong correlation (r = 0.89) between the AHH activities of individuals who live in Ankara and smoke content of the air. Placental AHH activity did not show any relation to the age, nutritional and dietary habits, factors of indoor pollution, duration of pregnancy, nor did the weight, length and Apgar score of the babies.

  19. Allosteric regulation of phenylalanine hydroxylase.

    Science.gov (United States)

    Fitzpatrick, Paul F

    2012-03-15

    The liver enzyme phenylalanine hydroxylase is responsible for conversion of excess phenylalanine in the diet to tyrosine. Phenylalanine hydroxylase is activated by phenylalanine; this activation is inhibited by the physiological reducing substrate tetrahydrobiopterin. Phosphorylation of Ser16 lowers the concentration of phenylalanine for activation. This review discusses the present understanding of the molecular details of the allosteric regulation of the enzyme.

  20. Allosteric Regulation of Phenylalanine Hydroxylase

    OpenAIRE

    Fitzpatrick, Paul F.

    2011-01-01

    The liver enzyme phenylalanine hydroxylase is responsible for conversion of excess phenylalanine in the diet to tyrosine. Phenylalanine hydroxylase is activated by phenylalanine; this activation is inhibited by the physiological reducing substrate tetrahydrobiopterin. Phosphorylation of Ser16 lowers the concentration of phenylalanine for activation. This review discusses the present understanding of the molecular details of the allosteric regulation of the enzyme.

  1. Tissue Specific Expression of Cre in Rat Tyrosine Hydroxylase and Dopamine Active Transporter-Positive Neurons.

    Directory of Open Access Journals (Sweden)

    Zhenyi Liu

    Full Text Available The rat is a preferred model system over the mouse for neurological studies, and cell type-specific Cre expression in the rat enables precise ablation of gene function in neurons of interest, which is especially valuable for neurodegenerative disease modeling and optogenetics. Yet, few such Cre rats are available. Here we report the characterization of two Cre rats, tyrosine hydroxylase (TH-Cre and dopamine active transporter (DAT or Slc6a3-Cre, by using a combination of immunohistochemistry (IHC and mRNA fluorescence in situ hybridization (FISH as well as a fluorescent reporter for Cre activity. We detected Cre expression in expected neurons in both Cre lines. Interestingly, we also found that in Th-Cre rats, but not DAT-Cre rats, Cre is expressed in female germ cells, allowing germline excision of the floxed allele and hence the generation of whole-body knockout rats. In summary, our data demonstrate that targeted integration of Cre cassette lead to faithful recapitulation of expression pattern of the endogenous promoter, and mRNA FISH, in addition to IHC, is an effective method for the analysis of the spatiotemporal gene expression patterns in the rat brain, alleviating the dependence on high quality antibodies that are often not available against rat proteins. The Th-Cre and the DAT-Cre rat lines express Cre in selective subsets of dopaminergic neurons and should be particularly useful for researches on Parkinson's disease.

  2. Tissue Specific Expression of Cre in Rat Tyrosine Hydroxylase and Dopamine Active Transporter-Positive Neurons.

    Science.gov (United States)

    Liu, Zhenyi; Brown, Andrew; Fisher, Dan; Wu, Yumei; Warren, Joe; Cui, Xiaoxia

    2016-01-01

    The rat is a preferred model system over the mouse for neurological studies, and cell type-specific Cre expression in the rat enables precise ablation of gene function in neurons of interest, which is especially valuable for neurodegenerative disease modeling and optogenetics. Yet, few such Cre rats are available. Here we report the characterization of two Cre rats, tyrosine hydroxylase (TH)-Cre and dopamine active transporter (DAT or Slc6a3)-Cre, by using a combination of immunohistochemistry (IHC) and mRNA fluorescence in situ hybridization (FISH) as well as a fluorescent reporter for Cre activity. We detected Cre expression in expected neurons in both Cre lines. Interestingly, we also found that in Th-Cre rats, but not DAT-Cre rats, Cre is expressed in female germ cells, allowing germline excision of the floxed allele and hence the generation of whole-body knockout rats. In summary, our data demonstrate that targeted integration of Cre cassette lead to faithful recapitulation of expression pattern of the endogenous promoter, and mRNA FISH, in addition to IHC, is an effective method for the analysis of the spatiotemporal gene expression patterns in the rat brain, alleviating the dependence on high quality antibodies that are often not available against rat proteins. The Th-Cre and the DAT-Cre rat lines express Cre in selective subsets of dopaminergic neurons and should be particularly useful for researches on Parkinson's disease.

  3. In vitro residual activity of phenylalanine hydroxylase variants and correlation with metabolic phenotypes in PKU.

    Science.gov (United States)

    Trunzo, Roberta; Santacroce, Rosa; Shen, Nan; Jung-Klawitter, Sabine; Leccese, Angelica; De Girolamo, Giuseppe; Margaglione, Maurizio; Blau, Nenad

    2016-12-05

    Hyperphenylalaninemias (HPAs) are genetic diseases predominantly caused by a wide range of variants in the phenylalanine hydroxylase (PAH) gene. In vitro expression analysis of PAH variants offers the opportunity to elucidate the molecular mechanisms involved in HPAs and to clarify whether a disease-associated variant is genuinely pathogenic, while investigating the severity of a metabolic phenotype, and determining how a variant exerts its deleterious effects on the PAH enzyme. To study the effects of gene variants on PAH activity, we investigated eight variants: c.611A>G (p.Y204C), c.635T>C (p.L212P), c.746T>C (p.L249P), c.745C>T (p.L249F), c.809G>A (p.R270K), c.782G>C (p.R261P), c.587C>A (p.S196Y) and c.1139C>T (p.T380M), associated with different phenotypic groups. Transient expression of mutant full-length cDNAs in COS-7 cells yielded PAH proteins with PAH activity levels between 7% and 51% compared to the wild-type enzyme. With one exception (p.Y204C, which had no significant impact on PAH function), lower PAH activity was associated with a more severe phenotype (e.g. p.L249P with 7% PAH activity, 100% of classic PKU and no BH4 responsiveness), while higher activity correlated with milder phenotypes (e.g. p.T380M with 28% PAH activity, 97% of mild HPA and 83% of BH4 responsiveness). The results of the in vitro residual PAH activity have major implications, both for our understanding of genotype-phenotype correlations, and thereby existing inconsistencies, but also for the elucidation of the molecular basis of tetrahydrobiopterin (BH4) responsiveness.

  4. Effect of Water Miscible Organic Solvents on p-Nitrophenol Hydroxylase (CYP2E1) Activity in Rat Liver Microsomes.

    Science.gov (United States)

    Patil, Pranali G; Kamble, S H; Shah, T S; Iyer, K R

    2015-01-01

    Organic solvents used for solubilization of the substrates/NCEs are known to affect the activity of cytochrome P450 enzymes. Further, this effect varies with the solvents used, the substrates and CYP450 isoforms in question. In the present study, we have investigated the effect of ten commonly used water miscible organic solvents (methanol, ethanol, 1-propanol, 2-propanol, acetonitrile, acetone, dimethyl sulphoxide, N,N-dimethyl formamide, dioxane and polyethylene glycol 400) on p-nitrophenol hydroxylase activity at 0, 0.1, 0.25, 0.5, 0.75 and 1% v/v concentration in rat liver microsomes. All the solvents studied showed concentration dependent inhibition of the p-nitrophenol hydroxylase activity except acetonitrile which showed activation of the activity at concentration range studied. Out of ten solvents studied, dioxane was found to be the most inhibitory solvent (inhibition >90% at 0.25% v/v concentration). Overall, solvents like dimethyl sulphoxide, dimethyl formamide and dioxane appeared to be unsuitable for characterizing p-nitrophenol hydroxylase (CYP2E1-mediated) reactions due to a high degree of inhibition. On the other hand, methanol and acetonitrile at concentrations <0.5% v/v appeared to be appropriate solvents for substrate solubilization while evaluating CYP2E1-mediated catalysis. The results of this study imply that caution should be exercised while choosing solvents for dissolution of substrate during enzyme studies in liver microsomes.

  5. Effect of water miscible organic solvents on p-nitrophenol hydroxylase (CYP2E1 activity in rat liver microsomes

    Directory of Open Access Journals (Sweden)

    Pranali G Patil

    2015-01-01

    Full Text Available Organic solvents used for solubilization of the substrates/NCEs are known to affect the activity of cytochrome P450 enzymes. Further, this effect varies with the solvents used, the substrates and CYP450 isoforms in question. In the present study, we have investigated the effect of ten commonly used water miscible organic solvents (methanol, ethanol, 1-propanol, 2-propanol, acetonitrile, acetone, dimethyl sulphoxide, N,N-dimethyl formamide, dioxane and polyethylene glycol 400 on p-nitrophenol hydroxylase activity at 0, 0.1, 0.25, 0.5, 0.75 and 1% v/v concentration in rat liver microsomes. All the solvents studied showed concentration dependent inhibition of the p-nitrophenol hydroxylase activity except acetonitrile which showed activation of the activity at concentration range studied. Out of ten solvents studied, dioxane was found to be the most inhibitory solvent (inhibition >90% at 0.25% v/v concentration. Overall, solvents like dimethyl sulphoxide, dimethyl formamide and dioxane appeared to be unsuitable for characterizing p-nitrophenol hydroxylase (CYP2E1-mediated reactions due to a high degree of inhibition. On the other hand, methanol and acetonitrile at concentrations <0.5% v/v appeared to be appropriate solvents for substrate solubilization while evaluating CYP2E1-mediated catalysis. The results of this study imply that caution should be exercised while choosing solvents for dissolution of substrate during enzyme studies in liver microsomes.

  6. Activation of phenylalanine hydroxylase induces positive cooperativity toward the natural cofactor.

    Science.gov (United States)

    Gersting, Søren W; Staudigl, Michael; Truger, Marietta S; Messing, Dunja D; Danecka, Marta K; Sommerhoff, Christian P; Kemter, Kristina F; Muntau, Ania C

    2010-10-01

    Protein misfolding with loss-of-function of the enzyme phenylalanine hydroxylase (PAH) is the molecular basis of phenylketonuria in many individuals carrying missense mutations in the PAH gene. PAH is complexly regulated by its substrate L-Phenylalanine and its natural cofactor 6R-L-erythro-5,6,7,8-tetrahydrobiopterin (BH(4)). Sapropterin dihydrochloride, the synthetic form of BH(4), was recently approved as the first pharmacological chaperone to correct the loss-of-function phenotype. However, current knowledge about enzyme function and regulation in the therapeutic setting is scarce. This illustrates the need for comprehensive analyses of steady state kinetics and allostery beyond single residual enzyme activity determinations to retrace the structural impact of missense mutations on the phenylalanine hydroxylating system. Current standard PAH activity assays are either indirect (NADH) or discontinuous due to substrate and product separation before detection. We developed an automated fluorescence-based continuous real-time PAH activity assay that proved to be faster and more efficient but as precise and accurate as standard methods. Wild-type PAH kinetic analyses using the new assay revealed cooperativity of activated PAH toward BH(4), a previously unknown finding. Analyses of structurally preactivated variants substantiated BH(4)-dependent cooperativity of the activated enzyme that does not rely on the presence of l-Phenylalanine but is determined by activating conformational rearrangements. These findings may have implications for an individualized therapy, as they support the hypothesis that the patient's metabolic state has a more significant effect on the interplay of the drug and the conformation and function of the target protein than currently appreciated.

  7. Influence of some anti-inflammatory drugs on the activity of aryl hydrocarbon hydroxylase and the cytochrome P450 content

    Energy Technology Data Exchange (ETDEWEB)

    Mostafa, M.H.; Sheweita, S.A.; Abdel-Moneam, N.M. (Alexandria Univ. (Egypt))

    1990-06-01

    The metabolism of benzo({alpha})pyrene is mediated by the mixed function oxidase system including the cytochrome P450-dependent aryl hydrocarbon hydroxylase. The data of the present study revealed the ability of various commonly used anti-inflammatory drugs to alter the activity of this enzyme system, where all the tested drugs, namely phenyl butazone, ketoprofen, piroxicam, and acetaminophen, caused an increase in both the activity of aryl hydrocarbon hydroxylase and the cytochrome P450 content whether administered as a single dose or as a repeated dose for 6 consecutive days. The percentage of change for all drugs except phenyl butazone was proportional to the duration of drug administration. On the other hand, pyrazole which is chemically related to phenyl butazone, had no significant effect when administered as a single dose but caused a decrease in both studied parameters when administered as a repeated dose for 6 consecutive days. The mechanisms by which these commonly used drugs modify the aryl hydrocarbon hydroxylase activity and the cytochrome p450 content are discussed in the text.

  8. The dopamine beta-hydroxylase inhibitor nepicastat increases dopamine release and potentiates psychostimulant-induced dopamine release in the prefrontal cortex.

    Science.gov (United States)

    Devoto, Paola; Flore, Giovanna; Saba, Pierluigi; Bini, Valentina; Gessa, Gian Luigi

    2014-07-01

    The dopamine-beta-hydroxylase inhibitor nepicastat has been shown to reproduce disulfiram ability to suppress the reinstatement of cocaine seeking after extinction in rats. To clarify its mechanism of action, we examined the effect of nepicastat, given alone or in association with cocaine or amphetamine, on catecholamine release in the medial prefrontal cortex and the nucleus accumbens, two key regions involved in the reinforcing and motivational effects of cocaine and in the reinstatement of cocaine seeking. Nepicastat effect on catecholamines was evaluated by microdialysis in freely moving rats. Nepicastat reduced noradrenaline release both in the medial prefrontal cortex and in the nucleus accumbens, and increased dopamine release in the medial prefrontal cortex but not in the nucleus accumbens. Moreover, nepicastat markedly potentiated cocaine- and amphetamine-induced extracellular dopamine accumulation in the medial prefrontal cortex but not in the nucleus accumbens. Extracellular dopamine accumulation produced by nepicastat alone or by its combination with cocaine or amphetamine was suppressed by the α2 -adrenoceptor agonist clonidine. It is suggested that nepicastat, by suppressing noradrenaline synthesis and release, eliminated the α2 -adrenoceptor mediated inhibitory mechanism that constrains dopamine release and cocaine- and amphetamine-induced dopamine release from noradrenaline or dopamine terminals in the medial prefrontal cortex.

  9. Generation of Two Noradrenergic-Specific Dopamine-Beta-Hydroxylase-FLPo Knock-In Mice Using CRISPR/Cas9-Mediated Targeting in Embryonic Stem Cells.

    Directory of Open Access Journals (Sweden)

    Jenny J Sun

    Full Text Available CRISPR/Cas9 mediated DNA double strand cutting is emerging as a powerful approach to increase rates of homologous recombination of large targeting vectors, but the optimization of parameters, equipment and expertise required remain barriers to successful mouse generation by single-step zygote injection. Here, we sought to apply CRISPR/Cas9 methods to traditional embryonic stem (ES cell targeting followed by blastocyst injection to overcome the common issues of difficult vector construction and low targeting efficiency. To facilitate the study of noradrenergic function, which is implicated in myriad behavioral and physiological processes, we generated two different mouse lines that express FLPo recombinase under control of the noradrenergic-specific Dopamine-Beta-Hydroxylase (DBH gene. We found that by co-electroporating a circular vector expressing Cas9 and a locus-specific sgRNA, we could target FLPo to the DBH locus in ES cells with shortened 1 kb homology arms. Two different sites in the DBH gene were targeted; the translational start codon with 6-8% targeting efficiency, and the translational stop codon with 75% targeting efficiency. Using this approach, we established two mouse lines with DBH-specific expression of FLPo in brainstem catecholaminergic populations that are publically available on MMRRC (MMRRC_041575-UCD and MMRRC_041577-UCD. Altogether, this study supports simplified, high-efficiency Cas9/CRISPR-mediated targeting in embryonic stem cells for production of knock-in mouse lines in a wider variety of contexts than zygote injection alone.

  10. Increased activity of tyrosine hydroxylase in the cerebellum of the x-irradiated dystonic rat

    Energy Technology Data Exchange (ETDEWEB)

    Dopico, A.M.; Rios, H.; Mayo, J.; Zieher, L.M. (Departamentos de Biologia Celular e Histologia y de Farmacologia y Toxicologia, Facultad de Medicina, Universidad de Buenos Aires, (Argentina))

    1990-08-01

    The exposure of the cephalic end of rats to repeated doses of x-irradiation (150 rad) immediately after birth induces a long-term increase in the noradrenaline (NA) content of cerebellum (CE) (+ 37.8%), and a decrease in cerebellar weight (65.2% of controls), which results in an increased NA concentration (+ 109%). This increase in the neurotransmitter level is accompanied by a dystonic syndrome and histological abnormalities: Purkinje cells (the target cells for NA afferents to CE) fail to arrange in a characteristic monolayer, and their primary dendritic tree appears randomly oriented. The injection of reserpine 0.9 and 1.2 mg/kg ip to adult rats for 18 h depletes cerebellar NA content in both controls (15.7 {plus minus} 4 ng/CE and 2.8 {plus minus} 1.5 ng/CE, respectively) and x-irradiated rats (17.1 {plus minus} 1 ng/CE and 8.3 {plus minus} 2 ng/CE, respectively). The activity of tyrosine hydroxylase (TH) in CE of adult rats, measured by an in vitro assay, is significantly increased in neonatally x-irradiated animals when compared to age-matched controls (16.4 {plus minus} 1.4 vs 6.32 {plus minus} 0.6 nmol CO2/h/mg prot., p less than 0.01). As observed for NA levels, a net increase in TH activity induced by the ionizing radiation is also measured: 308.9 {plus minus} 23.8 vs 408.2 {plus minus} 21.5 nmol CO2/h/CE, p less than 0.01 (controls and x-treated, respectively). These results suggest that x-irradiation at birth may induce an abnormal sprouting of noradrenergic afferents to CE. The possibility that these changes represent a response of the NA system to the dystonic syndrome is discussed.

  11. Phenylalanine hydroxylase activity and expression in chicks subjected to phenylalanine imbalance or phenylalanine toxicity.

    Science.gov (United States)

    Lartey, F M; Austic, R E

    2009-04-01

    Experiments were performed to investigate the activity of hepatic Phe hydroxylase (PAH) and plasma amino acid concentrations under conditions of Phe imbalance or toxicity in chicks fed on experimental diets from 7 to 14 or 16 d of age. In experiment 1, Phe imbalance was created by adding 10% of a mixture of indispensable amino acids lacking Phe (IAA - Phe) to a basal diet containing 0.46% Phe. The activity of PAH was not significantly affected by the imbalance. Correcting the imbalance by adding 1.12% Phe to the diet prevented the growth impairment and increased the activity of PAH. In experiment 2, growth was reduced by the addition of excess (2%) Phe to the basal diet. Correcting the excess by adding the IAA - Phe to the diet prevented the growth reduction. The activity of PAH was not significantly affected by 2% Phe, but it increased in chicks fed the corrected diet. The levels of PAH mRNA were not affected by the dietary treatments. A factorial arrangement of treatments with 3 dietary levels of Phe (0.46, 1.58, and 2.46%) with or without the IAA - Phe was used in experiment 3. The effects on growth were similar to those of the same treatments in experiments 1 and 2. The addition of Phe significantly increased hepatic PAH activity, but there was no detectable main effect of the IAA - Phe and no interaction. Plasma Phe concentration was increased by dietary Phe and decreased by the IAA - Phe mixture. We conclude that hepatic PAH activity in chicks variably increases in response to Phe or a 10% dietary supplement of indispensable amino acids including Phe but does not increase in response to IAA - Phe when the amino acids are added to a diet that is marginally adequate in Phe. The increased activity does not involve changes in PAH mRNA. The effects of IAA - Phe on plasma Phe concentrations appear to be independent of hepatic PAH activity as measured in vitro.

  12. The Amino Acid Specificity for Activation of Phenylalanine Hydroxylase Matches the Specificity for Stabilization of Regulatory Domain Dimers.

    Science.gov (United States)

    Zhang, Shengnan; Hinck, Andrew P; Fitzpatrick, Paul F

    2015-08-25

    Liver phenylalanine hydroxylase is allosterically activated by phenylalanine. The structural changes that accompany activation have not been identified, but recent studies of the effects of phenylalanine on the isolated regulatory domain of the enzyme support a model in which phenylalanine binding promotes regulatory domain dimerization. Such a model predicts that compounds that stabilize the regulatory domain dimer will also activate the enzyme. Nuclear magnetic resonance spectroscopy and analytical ultracentrifugation were used to determine the ability of different amino acids and phenylalanine analogues to stabilize the regulatory domain dimer. The abilities of these compounds to activate the enzyme were analyzed by measuring their effects on the fluorescence change that accompanies activation and on the activity directly. At concentrations of 10-50 mM, d-phenylalanine, l-methionine, l-norleucine, and (S)-2-amino-3-phenyl-1-propanol were able to activate the enzyme to the same extent as 1 mM l-phenylalanine. Lower levels of activation were seen with l-4-aminophenylalanine, l-leucine, l-isoleucine, and 3-phenylpropionate. The ability of these compounds to stabilize the regulatory domain dimer agreed with their ability to activate the enzyme. These results support a model in which allosteric activation of phenylalanine hydroxylase is linked to dimerization of regulatory domains.

  13. Attenuation of voluntary ethanol consumption by dopamine-beta-hydroxylase inhibition (FLA-57): mediated by changes in aversion, reinforcement or both.

    Science.gov (United States)

    Amit, Z; Gill, K; Ng Cheong Ton, J M

    1991-01-01

    The dopamine-beta-hydroxylase inhibitor, FLA-57, was reported by several investigators to reduce voluntary ethanol consumption in rats. The nature of the effect of FLA-57 on this behavior had been attributed to its involvement in both the mediation of positive reinforcing and aversive processes. In the present study, the capacity of FLA-57 to induce a conditioned taste aversion (CTA) in both a forward and a "nominally backward conditioning" paradigms was investigated. This was done in an attempt to assess the possible contribution of a FLA-57-induced CTA to the previously observed reduction in ethanol intake in several drinking studies. Furthermore, the ability of FLA-57 to induce a CTA in a nonnovel situation, where the taste of the presented solution (ethanol or saccharin) was familiar to the animals, was also assessed. The inclusion of these specific conditions was necessitated by the attempt to create conditions similar to those prevalent in drinking studies. We found that FLA-57, in both conditioning paradigms, induced a significant CTA. Animals, naive and experienced with the taste of ethanol or saccharin, exhibited a CTA following the administration of FLA-57. However, the magnitude and rate of extinction of the observed CTAs did not resemble those observed in studies on the effects of FLA-57 on ethanol intake. The results of this study suggest that while it is possible that FLA-57 exerts its effect on ethanol intake, at least in part, through an aversive mechanism, such a mechanism is unlikely to be the exclusive process through which ethanol ingestion is attenuated.

  14. Pollination-, development-, and auxin-specific regulation of gibberellin 3beta-hydroxylase gene expression in pea fruit and seeds.

    Science.gov (United States)

    Ozga, Jocelyn A; Yu, Jody; Reinecke, Dennis M

    2003-03-01

    To understand further how pollination, seeds, auxin (4-chloroindole-3-acetic acid [4-Cl-IAA]), and gibberellins (GAs) regulate GA biosynthesis in pea (Pisum sativum) fruit, we studied expression of the gene PsGA3ox1 that codes for the enzyme that converts GA(20) to biologically active GA(1) using real-time reverse transcription-polymerase chain reaction analysis. PsGA3ox1 mRNA levels were minimally detectable in prepollinated pericarps and ovules (-2 d after anthesis [DAA]), increased dramatically after pollination (0 DAA), then decreased by 1 DAA. Seed PsGA3ox1 mRNA levels increased at 4 DAA and again 8 to 12 DAA, when seed development was rapid. Pericarp PsGA3ox1 mRNA levels peaked coincidentally with rapid pod diameter expansion (6-10 DAA) to accommodate the growing seeds. The effects of seeds and hormones on the expression of pericarp PsGA3ox1 were investigated over a 24-h treatment period. Pericarp PsGA3ox1 mRNA levels gradually increased from 2 to 3 DAA when seeds were present; however, when the seeds were removed, the pericarp transcript levels dramatically declined. When 2-DAA deseeded pericarps were treated with 4-Cl-IAA, PsGA3ox1 mRNA levels peaked 4 h after hormone treatment (270-fold increase), then decreased. PsGA3ox1 mRNA levels in deseeded pericarps treated with indole-3-acetic acid or GA(3) were the same or lower than deseeded controls. These data show that PsGA3ox1 is expressed and developmentally regulated in pea pericarps and seeds. These data also show that pericarp PsGA3ox1 expression is hormonally regulated and suggest that the conversion of GA(20) to GA(1) occurs in the pericarp and is regulated by the presence of seeds and 4-Cl-IAA for fruit growth.

  15. Embryotoxicity, teratogenicity, and aryl hydrocarbon hydroxylase activity in Forster's terns on Green Bay, Lake Michigan

    Energy Technology Data Exchange (ETDEWEB)

    Hoffman, D.J.; Rattner, B.A.; Sileo, L.; Docherty, D.; Kubiak, T.J.

    1987-02-01

    Known reproductive problems, including congenital malformations and poor hatching success, exist for the state endangered Forster's tern (Sterna forsteri) in Green Bay, Wisconsin. Twenty Forster's tern eggs were collected from separate nests at (i) a natural colony with documented reproductive problems, situated at Green Bay, Lake Michigan, and (ii) an inland colony at Lake Poygan (control) where reproduction was documented as normal. Eggs from the two locations were placed in the same laboratory incubator and candled throughout incubation. Hatching success of Green Bay eggs was 52% of that for controls. Several early embryonic deaths occurred, but most mortality occurred close to the time of hatching. Liver microsomal aryl hydrocarbon hydroxylase activity was elevated approximately threefold in Green Bay hatchlings compared to controls. Green Bay terns that hatched weighed less than controls, had an increased liver to body weight ratio, and had a shorter femur length. Two Green Bay embryos that failed to hatch had anomalies, one with a crossed beak and one with poor ossification of the foot. One Green Bay hatchling had an abnormally ossified ilium. These effects were observed in eggs where there were measurable levels of aryl hydrocarbon hydroxylase inducers including polychlorinated biphenyls and polychlorinated dibenzo-p-dioxins.

  16. Complement activation by the amyloid proteins A beta peptide and beta 2-microglobulin

    DEFF Research Database (Denmark)

    Nybo, Mads; Nielsen, E H; Svehag, S E

    1999-01-01

    Complement activation (CA) has been reported to play a role in the pathogenesis of Alzheimer's disease (AD). To investigate whether CA may contribute to amyloidogenesis in general, the CA potential of different amyloid fibril proteins was tested. CA induced by A beta preparations containing soluble...... protein, protofilaments and some fibrils or only fibrils in a solid phase system (ELISA) was modest with a slow kinetics compared to the positive delta IgG control. Soluble A beta induced no detectable CA in a liquid phase system (complement consumption assay) while fibrillar A beta caused CA at 200 mg....../ml and higher concentrations. Soluble beta 2-microglobulin (beta 2M) purified from peritoneal dialysates was found to be as potent a complement activator as A beta in both solid and liquid phase systems while beta 2M purified from urine exhibited lower activity, a difference which may be explained...

  17. Enzymatic changes in phenylalanine ammonia-lyase, cinnamic-4-hydroxylase, capsaicin synthase, and peroxidase activities in capsicum under drought stress.

    Science.gov (United States)

    Phimchan, Paongpetch; Chanthai, Saksit; Bosland, Paul W; Techawongstien, Suchila

    2014-07-23

    Penylalanine ammonia-lyase (PAL), cinnamic-4-hydroxylase (C4H), capsaicin synthase (CS), and peroxidase (POD) are involved in the capsaicinoid biosynthesis pathway and may be altered in cultivars with different pungency levels. This study clarified the action of these enzymes under drought stress for hot Capsicum cultivars with low, medium,and high pungency levels. At the flowering stage, control plants were watered at field capacity, whereas drought-induced plants were subjected to gradual drought stress. Under drought stress, PAL, C4H, CS, and POD enzyme activities increased as compared to the non-drought-stressed plants. A novel discovery was that PAL was the critical enzyme in capsaicinoid biosynthesis under drought stress because its activities and capsaicinoid increased across the different pungency levels of hot pepper cultivars examined.

  18. Enhancement of L-tryptophan 5-hydroxylation activity by structure-based modification of L-phenylalanine 4-hydroxylase from Chromobacterium violaceum.

    Science.gov (United States)

    Kino, Kuniki; Hara, Ryotaro; Nozawa, Ai

    2009-09-01

    The objective of this study was to enhance l-tryptophan hydroxylation activity of l-phenylalanine 4-hydroxylase. It had been known that l-phenylalanine 4-hydroxylase from Chromobacterium violaceum could convert l-tryptophan to 5-hydroxy-l-tryptophan and l-phenylalanine to l-tyrosine; however, the activity for l-tryptophan was extremely low compared to l-phenylalanine activity levels. We used the information on the crystal structures of aromatic amino acid hydroxylases to generate C. violaceuml-phenylalanine 4-hydroxylase with high l-tryptophan hydroxylating activity. In silico structural modeling analysis suggested that hydrophobic and/or stacking interactions with the substrate and cofactor at L101 and W180 in C. violaceuml-phenylalanine 4-hydroxylase would increase hydroxylation activity. Based on this hypothesis, we introduced a saturation mutagenesis towards these sites followed by the evaluation of 5-hydroxy-l-tryptophan productivity using a modified Gibbs assay. Three and nine positive mutants were obtained from the L101 and W180 mutant libraries, respectively. Among the mutants, L101Y and W180F showed the highest l-tryptophan hydroxylation activity at the respective residues. Steady-state kinetic analysis revealed that k(cat) values for l-tryptophan hydroxylation were increased from 0.40 (wild-type) to 1.02 (L101Y) and 0.51 s(-1) (W180F). In addition, the double mutant (L101Y-W180F) displayed higher l-tryptophan hydroxylation activity than the wild-type and the W180F and L101Y mutants. The k(cat) value of L101Y-W180F increased to 2.08 s(-1), showing a 5.2-fold increase compared to wild-type enzyme levels.

  19. Suppression of sterol 27-hydroxylase mRNA and transcriptional activity by bile acids in cultured rat hepatocytes

    NARCIS (Netherlands)

    Twisk, J.; Wit, E.C.M. de; Princen, H.M.G.

    1995-01-01

    In previous work we have demonstrated suppression of cholesterol 7α-hydroxylase by bile acids at the level of mRNA and transcription, resulting in a similar decline in bile acid synthesis in cultured rat hepatocytes. In view of the substantial contribution of the 'alternative' or '27-hydroxylase' ro

  20. In Vitro Interaction of 5-Hydroxytrptamine with Cytosolic Molybdenum Hydroxylases as a Potential Inhibitor for Initial Rates Activities

    Directory of Open Access Journals (Sweden)

    Abdullah M. Al-Mohizea

    2010-01-01

    Full Text Available Problem statement: The role of 5-HT has been investigated in many behavioral activities. Thus, studies using raphe lesion showed that 5-HT is involved in sleep, general activity levels, habituation, aggression, pain sensitivity and morphine analgesia, avoidance behavior, self-stimulation and water consumption. Approach: The metabolic interaction between serotonin (5- hydroxytrptamine and indole-3-aldehyde and xanthine via aldehyde oxidase (EC 1.2.3.1 and xanthine oxidase (EC 1.1.3.22, respectively, were studied in liver tissue homogenate of Dunkin-Hartley guinea pigs by following the decrease in substrate concentration using spectrophotometer. Homogenates of liver were incubated with indole-3-aldehyde in the presence and absence of serotonin or (chlorpromazine and allopurinol a potent and selective inhibitors for aldehyde oxidase and xanthine oxidase, respectively. Oxidation of indole-3-aldehyde to indole-3-acetic acid was reduced up to 63.2% in the presence of serotonin (100 µM, while oxidation of xanthine to uric acid was reduced up to 51.6% under the same conditions. Results: In comparison, incubation of the substrates with their specific inhibitors (100 µM of chlorpromazine and 100 µM allopurinol give almost complete inhibition. These results demonstrate that in the guinea pig liver a metabolic interaction between serotonin and indole-3-aldehyde or xanthine via molybdenum hydroxylases system may take place in liver, which is the main tissue for xenobiotics detoxification. Conclusion: The overall conclusion from this research is that serotonin could be a protector for neurons and other tissue from the insult of oxidation of aldehydes and xanthines by molybdenum hydroxylases.

  1. Genetic analysis of beta1 integrin "activation motifs" in mice

    DEFF Research Database (Denmark)

    Czuchra, Aleksandra; Meyer, Hannelore; Legate, Kyle R

    2006-01-01

    tails, leading to tail separation and integrin activation. We analyzed mice in which we mutated the tyrosines of the beta1 tail and the membrane-proximal aspartic acid required for the salt bridge. Tyrosine-to-alanine substitutions abolished beta1 integrin functions and led to a beta1 integrin......-null phenotype in vivo. Surprisingly, neither the substitution of the tyrosines with phenylalanine nor the aspartic acid with alanine resulted in an obvious defect. These data suggest that the NPXY motifs of the beta1 integrin tail are essential for beta1 integrin function, whereas tyrosine phosphorylation......Akey feature of integrins is their ability to regulate the affinity for ligands, a process termed integrin activation. The final step in integrin activation is talin binding to the NPXY motif of the integrin beta cytoplasmic domains. Talin binding disrupts the salt bridge between the alpha/beta...

  2. Affinity labeling of the active site and the reactive sulfhydryl associated with activation of rat liver phenylalanine hydroxylase

    Energy Technology Data Exchange (ETDEWEB)

    Gibbs, B.S.; Benkovic, S.J. (Pennsylvania State Univ., University Park (United States))

    1991-07-09

    A pterin analogue, 5-((3-azido-6-nitrobenzylidene)amino)-2,6-diamino-4-pyrimidinone (AN-BADP), was synthesized as a probe of the pterin binding site of phenylalanine hydroxylase. The photoaffinity label has been found to be a competitive inhibitor of the enzyme with respect to 6,7-dimethyltetrahydropterin, having a K{sub i} of 8.8{plus minus}1.1 {mu}M. The irreversible labeling of phenylalanine hydroxylase by the photoaffinity label upon irradiation is both concentration and time dependent. phenylalanine hydroxylase is covalently labeled with a stoichiometry of 0.87{plus minus}0.08 mol of label/enzyme subunit. 5-Deaza-6-methyltetrahydropterin protects against inactivation and both 5-deaza-6-methyltetrahydropterin and 6-methyltetrahydropterin protect against covalent labeling, indicating that labeling occurs at the pterin binding site. Three tryptic peptides were isolated from ({sup 3}H)ANBADP-photolabeled enzyme and sequenced. All peptides indicated the sequence Thr-Leu-Lys-Ala-Leu-Tyr-Lys (residues 192-198). The residues labeled with ({sup 3}H)ANBADP were Lys198 and Lys194, with the majority of the radioactivity being associated with Lys198. Tryptic and chymotryptic peptides were isolated from fluorescein-labeled enzyme and sequenced. The modified residue was identified as Cys236.

  3. Phenylalanine hydroxylase deficiency.

    Science.gov (United States)

    Mitchell, John J; Trakadis, Yannis J; Scriver, Charles R

    2011-08-01

    Phenylalanine hydroxylase deficiency is an autosomal recessive disorder that results in intolerance to the dietary intake of the essential amino acid phenylalanine. It occurs in approximately 1:15,000 individuals. Deficiency of this enzyme produces a spectrum of disorders including classic phenylketonuria, mild phenylketonuria, and mild hyperphenylalaninemia. Classic phenylketonuria is caused by a complete or near-complete deficiency of phenylalanine hydroxylase activity and without dietary restriction of phenylalanine most children will develop profound and irreversible intellectual disability. Mild phenylketonuria and mild hyperphenylalaninemia are associated with lower risk of impaired cognitive development in the absence of treatment. Phenylalanine hydroxylase deficiency can be diagnosed by newborn screening based on detection of the presence of hyperphenylalaninemia using the Guthrie microbial inhibition assay or other assays on a blood spot obtained from a heel prick. Since the introduction of newborn screening, the major neurologic consequences of hyperphenylalaninemia have been largely eradicated. Affected individuals can lead normal lives. However, recent data suggest that homeostasis is not fully restored with current therapy. Treated individuals have a higher incidence of neuropsychological problems. The mainstay of treatment for hyperphenylalaninemia involves a low-protein diet and use of a phenylalanine-free medical formula. This treatment must commence as soon as possible after birth and should continue for life. Regular monitoring of plasma phenylalanine and tyrosine concentrations is necessary. Targets of plasma phenylalanine of 120-360 μmol/L (2-6 mg/dL) in the first decade of life are essential for optimal outcome. Phenylalanine targets in adolescence and adulthood are less clear. A significant proportion of patients with phenylketonuria may benefit from adjuvant therapy with 6R-tetrahydrobiopterin stereoisomer. Special consideration must be

  4. Mapping of the Allosteric Site in Cholesterol Hydroxylase CYP46A1 for Efavirenz, a Drug That Stimulates Enzyme Activity.

    Science.gov (United States)

    Anderson, Kyle W; Mast, Natalia; Hudgens, Jeffrey W; Lin, Joseph B; Turko, Illarion V; Pikuleva, Irina A

    2016-05-27

    Cytochrome P450 46A1 (CYP46A1) is a microsomal enzyme and cholesterol 24-hydroxylase that controls cholesterol elimination from the brain. This P450 is also a potential target for Alzheimer disease because it can be activated pharmacologically by some marketed drugs, as exemplified by efavirenz, the anti-HIV medication. Previously, we suggested that pharmaceuticals activate CYP46A1 allosterically through binding to a site on the cytosolic protein surface, which is different from the enzyme active site facing the membrane. Here we identified this allosteric site for efavirenz on CYP46A1 by using a combination of hydrogen-deuterium exchange coupled to MS, computational modeling, site-directed mutagenesis, and analysis of the CYP46A1 crystal structure. We also mapped the binding region for the CYP46A1 redox partner oxidoreductase and found that the allosteric and redox partner binding sites share a common border. On the basis of the data obtained, we propose the mechanism of CYP46A1 allostery and the pathway for the signal transmission from the P450 allosteric site to the active site.

  5. Spectroscopic characterization of the catalytically competent ferrous site of the resting, activated, and substrate-bound forms of phenylalanine hydroxylase

    Energy Technology Data Exchange (ETDEWEB)

    Loeb, K.E.; Westre, T.E.; Hedman, B.; Hodgson, K.O.; Solomon, E.I. [Stanford Univ., CA (United States); Kappock, T.J.; Mitic, N.; Glasfeld, E.; Caradonna, J.P. [Yale Univ., New Haven, CT (United States)

    1997-02-26

    The geometric structure of the catalytically relevant ferrous active site of phenylalanine hydroxylase (PAH) has been investigated using magnetic circular dichroism (MCD) and X-ray absorption (XAS) spectroscopies. From the excited state ligand field transitions in the MCD spectrum, the temperature and field dependence of these transitions, and the XAS pre-edge shapes and intensities, the resting ferrous site of the `tense` from PAH is six-coordinate distorted octahedral. The low ligand field strength observed in the MCD spectrum results from significant oxygen ligation and longer Fe-O/N bond distances relative to model complexes as determined from an EXAFS analysis. Substrate-induced allosteric activation ({approx}34 kcal/mol) does not alter the structure of the iron site in the `relaxed` form of PAH compared to the substrate-bound `tense` state. Thus, while activation is necessary for the enzyme to achieve complete catalytic competence, it does not appear to affect the geometry of the catalytically relevent six-coordinate ferrous active site and only directly influences the surrounding protein conformation. In contrast, substrate addition results in a geometric and electronic structural change at the iron center which may help orient the substrate for completely coupled hydroxylation. 106 refs., 10 figs., 6 tabs.

  6. Polymorphism in the tyrosine hydroxylase (TH gene is associated with activity-impulsivity in German Shepherd Dogs.

    Directory of Open Access Journals (Sweden)

    Eniko Kubinyi

    Full Text Available We investigated the association between repeat polymorphism in intron 4 of the tyrosine hydroxylase (TH gene and two personality traits, activity-impulsivity and inattention, in German Shepherd Dogs. The behaviour of 104 dogs was characterized by two instruments: (1 the previously validated Dog-Attention Deficit Hyperactivity Disorder Rating Scale (Dog-ADHD RS filled in by the dog owners and (2 the newly developed Activity-impulsivity Behavioural Scale (AIBS containing four subtests, scored by the experimenters. Internal consistency, inter-observer reliability, test-retest reliability and convergent validity were demonstrated for AIBS. Dogs possessing at least one short allele were proved to be more active-impulsive by both instruments, compared to dogs carrying two copies of the long allele (activity-impulsivity scale of Dog-ADHD RS: p = 0.007; AIBS: p = 0.023. The results have some potential to support human studies; however, further research should reveal the molecular function of the TH gene variants, and look for the effect in more breeds.

  7. Radiation-induced polymerization of {beta}(+)-pinene and synthesis of optically active {beta}(+)/{beta}(-)pinene polymers and copolymers

    Energy Technology Data Exchange (ETDEWEB)

    Cataldo, Franco, E-mail: franco.cataldo@fastwebnet.i [Lupi Chemical Research, Via Casilina 1626/A, 00133 Rome (Italy); Lilla, Edo; Ursini, Ornella [Institute of Chemical Methodologies, CNR, Via Salaria Km. 29300, Monterotondo Stazione 00016, Rome (Italy)

    2011-06-15

    Poly-{beta}(+)-pinene (pB(+)p) was synthesized with {gamma} irradiation of the monomer {beta}(+)-pinene in bulk under vacuum at 1181 kGy. Also scalemic mixtures of {beta}(+)-pinene and {beta}(-)-pinene were irradiated at 1181 kGy to obtain synthetic copolymers of pB(+)/B(-)p. For comparison also {beta}(-)-pinene was converted into poly-{beta}(-)-pinene (pB(-)p) under the identical conditions adopted for its enantiomer. Furthermore pB(+)p and pB(-)p were also synthesized by thermal processing under the action of a chemical free radical initiator. The optical rotatory dispersion (ORD) of all pBp resins synthesized were accurately studied in the spectral range comprised between 375 and 625 nm and a curious asymmetry in the ORD of pB(+)p versus the ORD of pB(-)p is reported. Furthermore, it is shown that (+)-p-menth-1-ene and (-)-p-menth-1-ene are useful as a model compounds for the pBp resins and for the explanation of the amplification of the optical activity of the {beta}(+)-pinene and {beta}(-)-pinene after their ring-opening polymerization to pB(+)p and pB(-)p. The pBp resins were studied also by FT-IR spectroscopy and by thermal analysis (TGA and DTG).

  8. AE activity during transient beta drops in high poloidal beta discharges

    Science.gov (United States)

    Huang, J.; Gong, X. Z.; Ren, Q. L.; Ding, S. Y.; Qian, J. P.; Pan, C. K.; Li, G. Q.; Heidbrink, W. W.; Garofalo, A. M.; McClenaghan, J.

    2016-10-01

    Enhanced AE activity has been observed during transient beta drops in high poloidal beta DIII-D discharges with internal transport barriers (ITBs). These drops in beta are believed to be caused by n=1 external kink modes. In some discharges, beta recovers within 200 ms but, in others, beta stays suppressed. A typical discharge has βP 3, qmin 3, and q95 12. The drop in beta affects both fast ions and thermal particles, and a drop is also observed in the density and rotation. The enhanced AE activity follows the instability that causes the beta drop, is largest at the lowest beta, and subsides as beta recovers. MHD stability analysis is planned. A database study of the plasma conditions associated with the collapse will be also presented. Supported in part by the US Department of Energy under DE-FC02-04ER54698, DE-AC05-06OR23100, and by the National Natural Science Foundation of China 11575249, and the National Magnetic Confinement Fusion Program of China No. 2015GB110005.

  9. Regulation of diurnal variation of cholesterol 7alpha-hydroxylase (CYP7A1) activity in healthy subjects.

    Science.gov (United States)

    Kovár, J; Lenícek, M; Zimolová, M; Vítek, L; Jirsa, M; Pitha, J

    2010-01-01

    Cholesterol 7alpha-hydroxylase (CYP7A1), the key regulatory enzyme of bile acid synthesis, displays a pronounced diurnal variation. To better understand the regulation of CYP7A1 activity, three day-long examinations were carried out in 12 healthy men. The concentrations of 7alpha-hydroxycholest-4-en-3-one (C4), a surrogate marker of CYP7A1 activity, bile acids (BA), insulin, glucose, nonesterified fatty acids, triglycerides, and cholesterol were measured in serum in 90-min intervals from 7 AM till 10 PM. To lower and to increase BA concentration during the study, the subjects received cholestyramine and chenodeoxycholic acid (CDCA), respectively, in two examinations. No drug was used in the control examination. There was a pronounced diurnal variation of C4 concentration with a peak around 1 PM in most of the subjects. The area under the curve (AUC) of C4 concentration was five times higher and three times lower when subjects were treated with cholestyramine and CDCA, respectively. No relationship was found between AUC of C4 and AUC of BA concentration, but AUC of C4 correlated positively with that of insulin. Moreover, short-term treatment with cholestyramine resulted in about 10 % suppression of glycemia throughout the day. Our results suggest that insulin is involved in the regulation of diurnal variation of CYP7A1 activity in humans.

  10. Threonine 788 in integrin subunit beta1 regulates integrin activation

    DEFF Research Database (Denmark)

    Nilsson, Stina; Kaniowska, Dorota; Brakebusch, Cord

    2006-01-01

    was identified as a site with major influence on integrin function. The mutation to A788 strongly reduced beta1-dependent cell attachment and exposure of the extracellular 9EG7 epitope, whereas replacement of T789 with alanine did not interfere with the ligand-binding ability. Talin has been shown to mediate......In the present study, the functional role of suggested phosphorylation of the conserved threonines in the cytoplasmic domain of integrin subunit beta1 was investigated. Mutants mimicking phosphorylated and unphosphorylated forms of beta1 were expressed in beta1 deficient GD25 cells. T788 in beta1...... integrin activation, but the talin head domain bound equally well to the wild-type beta1 and the mutants indicating that the T788A mutation caused defect integrin activation by another mechanism. The phosphorylation-mimicking mutation T788D was fully active in promoting cell adhesion. GD25 cells expressing...

  11. AGN 2979 [3(3-methoxyphenyl)-3-(3-dimethylaminopropyl)-4, 4-dimethylpiperidine-2,6-dione]. An inhibitor of the activation of tryptophan hydroxylase.

    Science.gov (United States)

    Boadle-Biber, M C; Phan, T H

    1986-05-01

    AGN 2979 [3-(3-methoxyphenyl)-3-(3-dimethylaminopropyl)-4, 4-dimethylpiperidine-2,6-dione] blocked the increase in tryptophan hydroxylase activity that occurred when slices of brainstem were exposed to a depolarizing medium or to agents that mobilize intracellular pools of calcium, but it had no effect on the activity of enzyme prepared from slices of brainstem incubated in control medium. AGN 2979 also blocked the calcium-calmodulin-dependent activation of tryptophan hydroxylase that was seen when supernatant preparations of the enzyme were exposed to phosphorylating conditions but not the activation induced by calcium-dependent proteases that was triggered by millimolar calcium concentrations. An identical pattern of inhibition has been found with the antipsychotic drugs, haloperidol and fluphenazine [Boadle-Biber, Biochem. Pharmac. 31, 2495 (1982)]. The sensitivity to the same inhibitors of both the activation of tryptophan hydroxylase produced by pretreatment of brainstem slices and that induced by incubation of supernatant preparations of enzyme under phosphorylating conditions suggests involvement of a common mechanism of enzyme activation in response to these different treatments.

  12. Latency and activation in the control of TGF-beta

    Science.gov (United States)

    Barcellos-Hoff, M. H.; Chatterjee, A. (Principal Investigator)

    1996-01-01

    The biological activity of the transforming growth factor-beta's (TGF-beta)3 is tightly controlled by their persistence in the extracellular compartment as latent complexes. Each of the three mammalian isoform genes encodes a product that is cleaved intracellularly to form two polypeptides, each of which dimerizes. Mature TGF-beta, a 24 kD homodimer, is noncovalently associated with the 80 kD latency-associated peptide (LAP). LAP is a fundamental component of TGF-beta that is required for its efficient secretion, prevents it from binding to ubiquitous cell surface receptors, and maintains its availability in a large extracellular reservoir that is readily accessed by activation. This latent TGF-beta complex (LTGF-beta) is secreted by all cells and is abundant both in circulating forms and bound to the extracellular matrix. Activation describes the collective events leading to the release of TGF-beta. Despite the importance of TGF-beta regulation of growth and differentiation in physiological and malignant tissue processes, remarkably little is known about the mechanisms of activation in situ. Recent studies of irradiated mammary gland reveal certain features of TGF-beta 1 activation that may shed light on its regulation and potential roles in the normal and neoplastic mammary gland.

  13. An active hAT transposable element causing bud mutation of carnation by insertion into the flavonoid 3'-hydroxylase gene.

    Science.gov (United States)

    Momose, Masaki; Nakayama, Masayoshi; Itoh, Yoshio; Umemoto, Naoyuki; Toguri, Toshihiro; Ozeki, Yoshihiro

    2013-04-01

    The molecular mechanisms underlying spontaneous bud mutations, which provide an important breeding tool in carnation, are poorly understood. Here we describe a new active hAT type transposable element, designated Tdic101, the movement of which caused a bud mutation in carnation that led to a change of flower color from purple to deep pink. The color change was attributed to Tdic101 insertion into the second intron of F3'H, the gene for flavonoid 3'-hydroxylase responsible for purple pigment production. Regions on the deep pink flowers of the mutant can revert to purple, a visible phenotype of, as we show, excision of the transposable element. Sequence analysis revealed that Tdic101 has the characteristics of an autonomous element encoding a transposase. A related, but non-autonomous element dTdic102 was found to move in the genome of the bud mutant as well. Its mobilization might be the result of transposase activities provided by other elements such as Tdic101. In carnation, therefore, the movement of transposable elements plays an important role in the emergence of a bud mutation.

  14. Effect of proline analogues on activity of human prolyl hydroxylase and the regulation of HIF signal transduction pathway.

    Directory of Open Access Journals (Sweden)

    Xiaoyan Ma

    Full Text Available Hypoxia inducible factor 1 (HIF-1 plays a pivotal role in cellular responses to hypoxia. Prolyl hydroxylase 3 (PHD3 degrades HIF-1α under normoxic conditions through the hydroxylation of HIF-1α for proteolysis. Inhibiting PHD3 activity is crucial for up-regulating HIF-1α, thereby acting as a potential target for treating hypoxia-related diseases. In this study, two proline analogues (PA1 and PA2 were screened as PHD3 inhibitors with apparent EC50 values of 1.53 and 3.17 µM respectively, indicating good inhibition potency. Nine proteins, significantly regulated by PA1, were identified using 2-DE coupled with MALDI-TOF/TOF MS. Pyruvate kinase isozymes M1/M2 (PKM and alpha-enolase 1 (ENO1, which are key modulators of glycolysis, are directly regulated by HIF-1α. Moreover, VEGF, a signal protein stimulating angiogenesis, was strongly promoted by PA1. Our findings suggest that PA1 stabilized HIF-1α as well as up-regulated glycolysis and angiogenesis proteins. Herein, for the first time, we systematically studied proline analogue PA1 as a PHD3 inhibitor, which provides innovative evidence for the treatment of HIF-related diseases.

  15. The crtS gene of Xanthophyllomyces dendrorhous encodes a novel cytochrome-P450 hydroxylase involved in the conversion of beta-carotene into astaxanthin and other xanthophylls.

    Science.gov (United States)

    Alvarez, Vanessa; Rodríguez-Sáiz, Marta; de la Fuente, Juan Luis; Gudiña, Eduardo J; Godio, Ramiro P; Martín, Juan F; Barredo, José Luis

    2006-04-01

    The conversion of beta-carotene into xanthophylls is a subject of great scientific and industrial interest. We cloned the crtS gene involved in astaxanthin biosynthesis from two astaxanthin producing strains of Xanthophyllomyces dendrorhous: VKPM Y2410, an astaxanthin overproducing strain, and the wild type ATCC 24203. In both cases, the ORF has a length of 3166 bp, including 17 introns, and codes for a protein of 62.6 kDa with similarity to cytochrome-P450 hydroxylases. crtS gene sequences from strains VKPM Y2410, ATCC 24203, ATCC 96594, and ATCC 96815 show several nucleotide changes, but none of them causes any amino acid substitution, except a G2268 insertion in the 13th exon of ATCC 96815 which causes a change in the reading frame. A G1470 --> A change in the 5' splicing region of intron 8 was also found in ATCC 96815. Both point mutations explain astaxanthin idiotrophy and beta-carotene accumulation in ATCC 96815. Mutants accumulating precursors of the astaxanthin biosynthetic pathway were selected from the parental strain VKPM Y2410 (red) showing different colors depending on the compound accumulated. Two of them were blocked in the biosynthesis of astaxanthin, M6 (orange; 1% astaxanthin, 71 times more beta-carotene) and M7 (orange; 1% astaxanthin, 58 times more beta-carotene, 135% canthaxanthin), whereas the rest produced lower levels of astaxanthin (5-66%) than the parental strain. When the crtS gene was expressed in M7, canthaxanthin accumulation disappeared and astaxanthin production was partially restored. Moreover, astaxanthin biosynthesis was restored when X. dendrorhous ATCC 96815 was transformed with the crtS gene. The crtS gene was heterologously expressed in Mucor circinelloides conferring to this fungus an improved capacity to synthesize beta-cryptoxanthin and zeaxanthin, two hydroxylated compounds from beta-carotene. These results show that the crtS gene is involved in the conversion of beta-carotene into xanthophylls, being potentially useful to

  16. American ginseng modulates pancreatic beta cell activities

    Directory of Open Access Journals (Sweden)

    Luo Luguang

    2007-10-01

    Full Text Available Abstract The mechanism of the beneficial effects of Panax quinquefolius (Xiyangshen, American ginseng on diabetes is yet to be elucidated. Recent studies show that Panax quinquefolius increases insulin production and reduces the death of pancreatic beta cells. Mechanism studies indicate that Panax quinquefolius improves cell's immuno-reactivity and mitochondrial function through various factors. Clinical studies show that Panax quinquefolius improves postprandial glycemia in type 2 diabetic patients. Further studies to identify the component(s of Panax quinquefolius linked with pancreatic islets/beta cells in vitro and in vivo are warranted for better understanding of the full effects of Panax quinquefolius.

  17. Cloning of the astaxanthin synthase gene from Xanthophyllomyces dendrorhous (Phaffia rhodozyma) and its assignment as a beta-carotene 3-hydroxylase/4-ketolase.

    Science.gov (United States)

    Ojima, Kazuyuki; Breitenbach, Jürgen; Visser, Hans; Setoguchi, Yutaka; Tabata, Kazuyuki; Hoshino, Tatsuo; van den Berg, Johan; Sandmann, Gerhard

    2006-02-01

    A gene has been cloned from Xanthophyllomyces dendrorhous by complementation of astaxanthin formation in a beta-carotene accumulating mutant. It consists of 3,166 bp and contains 17 introns. For the beta-carotene mutant ATCC 96815, a single point mutation in the splicing sequence of intron 8 was found. The resulting improper splicing of the mRNA results in an inactive protein. The cDNA of this beta-carotene oxygenase encodes a cytochrome P450 monooxygenase belonging to the 3A subfamily. P450-specific domains were identified including a cytochrome P450 and an oxygen binding motif. Electrons are provided by a cytochrome P450 reductase. Functional characterization of the enzyme by genetic modification of X. dendrorhous demonstrated that this P450 monooxygenase is multifunctional catalyzing all steps from beta-carotene to astaxanthin formation by oxygenation of carbon 3 and 4. The reaction sequence is first 4-ketolation of beta-carotene followed by 3-hydroxylation. A hydroxylation mechanism at allylic carbon atoms has been proposed for the generation of 4-keto and 3-hydroxy groups at both beta-ionone ends.

  18. O-GlcNAcylation of ATG4B positively regulates autophagy by increasing its hydroxylase activity.

    Science.gov (United States)

    Jo, Yoon Kyung; Park, Na Yeon; Park, So Jung; Kim, Byung-Gyu; Shin, Ji Hyun; Jo, Doo Sin; Bae, Dong-Jun; Suh, Young-Ah; Chang, Jeong Ho; Lee, Eun Kyung; Kim, Sang-Yeob; Kim, Jin Cheon; Cho, Dong-Hyung

    2016-08-30

    Autophagy is a catabolic degradation process and maintains cellular homeostasis. And autophagy is activated in response to various stress conditions. Although O-GlcNAcylation functions a sensor for nutrient and stress, the relationship between O-GlcNAcylation and autophagy is largely unknown. Here, we identified that ATG4B is novel target for O-GlcNAcylation under metabolic stress condition. Treatment with PugNAc, an O-GlcNAcase inhibitor increased activation of autophagy in SH-SY5Y cells. Both bimolecular fluorescence complementation and immunoprecipitation assay indicated that OGT directly interacts with ATG4B in SH-SY5Y cells. We also found that the O-GlcNAcylated ATG4B was increased in autophagy activation conditions, and down-regulation of OGT reduces O-GlcNAcylation of ATG4B under low glucose condition. Furthermore, the proteolytic activity of ATG4B for LC3 cleavage was enhanced in PugNAc-treated cells. Taken together, these results imply that O-GlcNAcylation of ATG4B regulates autophagy activation by increasing its proteolytic activity under metabolic stress condition.

  19. Phenylalanine ammonia-lyase, flavanone 3β-hydroxylase and flavonol synthase enzyme activity by a new in vitro assay method in berry fruits.

    Science.gov (United States)

    Flores, Gema; De la Peña Moreno, Fernando; Blanch, Gracia Patricia; Del Castillo, Maria Luisa Ruiz

    2014-06-15

    An HPLC method for the determination of phenylalanine ammonia-lyase, flavanone 3β-hydroxylase and flavonol synthase enzyme activity is proposed. This method is based on the determination of the compounds produced and consumed on the enzymatic reaction in just one chromatographic analysis. Optimisation of the method considered kinetic studies to establish the incubation time to perform the assay. The method here described proved to be an interesting approach to measure the activities of the three enzymes simultaneously increasing the rapidity, selectivity and sensitivity over other exiting methods. The enzyme activity method developed was applied to strawberry, raspberry, blackberry, redcurrant and blackcurrant fruits.

  20. Phenylalanine requirement, imbalance, and dietary excess in one-week-old chicks: growth and phenylalanine hydroxylase activity.

    Science.gov (United States)

    Lartey, F M; Austic, R E

    2008-02-01

    Two experiments were performed to study Phe imbalance and toxicity in 1-wk-old Babcock B380 chicks resulting from the addition of either a mixture of indispensable amino acids lacking Phe (IAA - Phe) or excess Phe to a diet that was nutritionally adequate in Phe. Chicks received a preexperimental semipurified diet for 1 wk and experimental diets from 7 to 14 d of age. In the first experiment, the chicks were given diets with Phe levels at 0.24, 0.29, 0.34, 0.39, 0.44, and 0.49% of the diet to determine the Phe requirement. The requirement of the chicks for Phe, based on weight gain and feed efficiency, was determined to be 0.39% of the diet. In experiment 2, the IAA - Phe (10% of the diet) or excess Phe (2% of the diet) was added to a diet containing 0.44% Phe. Chicks given the IAA - Phe or excess Phe had significantly slower growth rates than chicks given the basal diet (P > or = 0.05). The activities of the major hepatic enzyme of Phe catabolism, Phe hydroxylase (PAH), were significantly higher than that of chicks fed the basal diet when the chicks were fed the diets containing IAA - Phe plus 1.1% Phe (P > or = 0.05) but not when chicks were fed the diet containing IAA - Phe alone. The activity of PAH in chicks given the excess (2%) Phe was nearly 4 times the activity of PAH in chicks given the basal diet. Adding IAA - Phe to the diet containing excess Phe also resulted in higher PAH activity than was observed in chicks fed the basal diet, although the activity was significantly lower than observed for chicks receiving the diet containing excess Phe alone (P > or = 0.05). It is concluded that hepatic PAH activity in chicks increases primarily in response to its substrate, Phe. A dietary amino acid load without Phe reduces this response to excess Phe.

  1. HYSCORE Analysis of the Effects of Substrates on Coordination of Water to the Active Site Iron in Tyrosine Hydroxylase.

    Science.gov (United States)

    McCracken, John; Eser, Bekir E; Mannikko, Donald; Krzyaniak, Matthew D; Fitzpatrick, Paul F

    2015-06-23

    Tyrosine hydroxylase is a mononuclear non-heme iron monooxygenase found in the central nervous system that catalyzes the hydroxylation of tyrosine to yield L-3,4-dihydroxyphenylalanine, the rate-limiting step in the biosynthesis of catecholamine neurotransmitters. Catalysis requires the binding of tyrosine, a tetrahydropterin, and O₂ at an active site that consists of a ferrous ion coordinated facially by the side chains of two histidines and a glutamate. We used nitric oxide as a surrogate for O₂ to poise the active site iron in an S = ³/₂ {FeNO}⁷ form that is amenable to electron paramagnetic resonance (EPR) spectroscopy. The pulsed EPR method of hyperfine sublevel correlation (HYSCORE) spectroscopy was then used to probe the ligands at the remaining labile coordination sites on iron. For the complex formed by the addition of tyrosine and nitric oxide, TyrH/NO/Tyr, orientation-selective HYSCORE studies provided evidence of the coordination of one H₂O molecule characterized by proton isotropic hyperfine couplings (A(iso) = 0.0 ± 0.3 MHz) and dipolar couplings (T = 4.4 and 4.5 ± 0.2 MHz). These data show complex HYSCORE cross peak contours that required the addition of a third coupled proton, characterized by an A(iso) of 2.0 MHz and a T of 3.8 MHz, to the analysis. This proton hyperfine coupling differed from those measured previously for H₂O bound to {FeNO}⁷ model complexes and was assigned to a hydroxide ligand. For the complex formed by the addition of tyrosine, 6-methyltetrahydropterin, and NO, TyrH/NO/Tyr/6-MPH₄, the HYSCORE cross peaks attributed to H₂O and OH⁻ for the TyrH/NO/Tyr complex were replaced by a cross peak due to a single proton characterized by an A(iso) of 0.0 MHz and a dipolar coupling (T = 3.8 MHz). This interaction was assigned to the N₅ proton of the reduced pterin.

  2. Loss of cholesterol 7 alpha-hydroxylase activity in vitro in the presence of bivalent metal ions and by dialysis of rat liver microsomes.

    Science.gov (United States)

    Sanghvi, A; Grassi, E; Diven, W

    1983-01-01

    A loss in cholesterol 7 alpha-hydroxylase activity [cholesterol 7 alpha-monooxygenase; cholesterol,NADPH:oxygen oxidoreductase (7 alpha-hydroxylating), EC 1.14.13.17] was seen when rat liver microsomes were incubated in the presence of Ca2+, Mg2+, or Mn2+. The loss in enzyme activity was complete within only 5 min of incubation with Ca2+ and Mn2+, whereas Mg2+ required 10 to 15 min of incubation with microsomes to produce a similar inhibition. This effect of metal ions could be blocked if the incubations were carried out in phosphate buffer. Similarly, preincubation of microsomes in the presence of NaF completely prevented the loss in enzyme activity due to Ca2+ and Mg2+ ions, but only partially the loss due to Mn2+. These results suggest metal ion activation of an endogenous microsomal phosphatase, which in turn may inactivate cholesterol 7 alpha-hydroxylase through its dephosphorylation. Further, a dialyzable microsomal factor appears to be essential for stabilizing the enzyme, because dialysis of a microsomal suspension results in a considerable loss of enzyme activity. PMID:6300898

  3. Mucor hiemalis mediated 14α-hydroxylation on steroids: in vivo and in vitro investigations of 14α-hydroxylase activity.

    Science.gov (United States)

    Kolet, Swati P; Haldar, Saikat; Niloferjahan, Siddiqui; Thulasiram, Hirekodathakallu V

    2014-07-01

    Transformation of testosterone and progesterone into synthetically challenging 14α-hydroxy derivatives was achieved by using fungal strain Mucor hiemalis. Prolonged incubation led to the formation of corresponding 6β/7α,14α-dihydroxy metabolites. The position and stereochemistry of newly introduced hydroxyl group was determined by detailed spectroscopic analyses. The time course experiment indicated that fungal strain initiated transformation by hydroxylation at 14α-position followed by at 6β- or 7α-positions. Studies using cell-free extracts suggest that the 14α-hydroxylase activity is NADPH dependent and belongs to the cytochrome P450 family.

  4. Urease inhibitory activities of beta-boswellic acid derivatives

    Directory of Open Access Journals (Sweden)

    Reza Hajiaghaee

    2013-01-01

    Full Text Available Background and the purpose of the study: Boswellia carterii have been used in traditional medicine for many years for management different gastrointestinal disorders. In this study, we wish to report urease inhibitory activity of four isolated compound of boswellic acid derivative.Methods 4 pentacyclic triterpenoid acids were isolated from Boswellia carterii and identified by NMR and Mass spectroscopic analysis (compounds 1, 3-O-acetyl-9,11-dehydro-beta-boswellic acid; 2, 3-O-acetyl-11-hydroxy-beta-boswellic acid; 3. 3-O- acetyl-11-keto-beta-boswellic acid and 4, 11-keto-beta-boswellic acid. Their inhibitory activity on Jack bean urease were evaluated. Docking and pharmacophore analysis using AutoDock 4.2 and Ligandscout 3.03 programs were also performed to explain possible mechanism of interaction between isolated compounds and urease enzyme.Results It was found that compound 1 has the strongest inhibitory activity against Jack bean urease (IC50 = 6.27 +/- 0.03 muM, compared with thiourea as a standard inhibitor (IC50 = 21.1 +/- 0.3 muM.Conclusion The inhibition potency is probably due to the formation of appropriate hydrogen bonds and hydrophobic interactions between the investigated compounds and urease enzyme active site and confirms its traditional usage.

  5. Polypeptides having beta-glucosidase activity and polynucleotides encoding same

    Energy Technology Data Exchange (ETDEWEB)

    Harris, Paul (Carnation, WA); Golightly, Elizabeth (Reno, NV)

    2011-06-14

    The present invention relates to isolated polypeptides having beta-glucosidase activity and isolated polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods for producing and using the polypeptides.

  6. Polypeptides having beta-glucosidase activity and polynucleotides encoding same

    Energy Technology Data Exchange (ETDEWEB)

    Harris, Paul (Carnation, WA); Golightly, Elizabeth (Reno, NV)

    2007-07-17

    The present invention relates to isolated polypeptides having beta-glucosidase activity and isolated polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods for producing and using the polypeptides.

  7. Polynucleotides encoding polypeptides having beta-glucosidase activity

    Energy Technology Data Exchange (ETDEWEB)

    Harris, Paul (Carnation, WA); Golightly, Elizabeth (Reno, NV)

    2010-03-02

    The present invention relates to isolated polypeptides having beta-glucosidase activity and isolated polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods for producing and using the polypeptides.

  8. Vaccinia virus recombinants expressing an 11-kilodalton beta-galactosidase fusion protein incorporate active beta-galactosidase in virus particles.

    Science.gov (United States)

    Huang, C; Samsonoff, W A; Grzelecki, A

    1988-10-01

    Recombinant plasmids in which vaccinia virus transcriptional regulatory sequences were fused to the Escherichia coli lacZ gene were constructed for insertion of the lacZ gene into the vaccinia virus genome. beta-Galactosidase (beta-gal) was found in some purified recombinant vaccinia virions. By enzyme activity, sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and microscopic techniques, the evidence suggested that beta-gal accounted for 5% of the total protein in the virion. These recombinant viruses were constructed so that a portion of the coding sequences of a late vaccinia virus structural polypeptide was fused to the amino terminus of beta-gal to produce the fusion protein. Removal of the coding sequences resulted in the complete loss of beta-gal activity. This demonstrated that a vaccinia virus DNA segment from a late structural gene is responsible for the incorporation of beta-gal into the virion.

  9. Potent and Selective Triazole-Based Inhibitors of the Hypoxia-Inducible Factor Prolyl-Hydroxylases with Activity in the Murine Brain

    Science.gov (United States)

    Chan, Mun Chiang; Atasoylu, Onur; Hodson, Emma; Tumber, Anthony; Leung, Ivanhoe K. H.; Chowdhury, Rasheduzzaman; Gómez-Pérez, Verónica; Demetriades, Marina; Rydzik, Anna M.; Holt-Martyn, James; Tian, Ya-Min; Bishop, Tammie; Claridge, Timothy D. W.; Kawamura, Akane; Pugh, Christopher W.; Ratcliffe, Peter J.; Schofield, Christopher J.

    2015-01-01

    As part of the cellular adaptation to limiting oxygen availability in animals, the expression of a large set of genes is activated by the upregulation of the hypoxia-inducible transcription factors (HIFs). Therapeutic activation of the natural human hypoxic response can be achieved by the inhibition of the hypoxia sensors for the HIF system, i.e. the HIF prolyl-hydroxylases (PHDs). Here, we report studies on tricyclic triazole-containing compounds as potent and selective PHD inhibitors which compete with the 2-oxoglutarate co-substrate. One compound (IOX4) induces HIFα in cells and in wildtype mice with marked induction in the brain tissue, revealing that it is useful for studies aimed at validating the upregulation of HIF for treatment of cerebral diseases including stroke. PMID:26147748

  10. Potent and Selective Triazole-Based Inhibitors of the Hypoxia-Inducible Factor Prolyl-Hydroxylases with Activity in the Murine Brain.

    Directory of Open Access Journals (Sweden)

    Mun Chiang Chan

    Full Text Available As part of the cellular adaptation to limiting oxygen availability in animals, the expression of a large set of genes is activated by the upregulation of the hypoxia-inducible transcription factors (HIFs. Therapeutic activation of the natural human hypoxic response can be achieved by the inhibition of the hypoxia sensors for the HIF system, i.e. the HIF prolyl-hydroxylases (PHDs. Here, we report studies on tricyclic triazole-containing compounds as potent and selective PHD inhibitors which compete with the 2-oxoglutarate co-substrate. One compound (IOX4 induces HIFα in cells and in wildtype mice with marked induction in the brain tissue, revealing that it is useful for studies aimed at validating the upregulation of HIF for treatment of cerebral diseases including stroke.

  11. Differential inhibition of 17alpha-hydroxylase and 17,20-lyase activities by three novel missense CYP17 mutations identified in patients with P450c17 deficiency

    NARCIS (Netherlands)

    E.L.T. van den Akker (Erica); J.W. Koper (Jan); A.L.M. Boehmer (Annemie); A.P.N. Themmen (Axel); M. Verhoef-Post (Miriam); M.A. Timmerman (Marianna); B.J. Otten (Barto); S.L.S. Drop (Stenvert); F.H. de Jong (Frank)

    2002-01-01

    textabstractThe microsomal enzyme cytochrome P450c17 is an important regulator of steroidogenesis. The enzyme has two functions: 17alpha-hydroxylase and 17,20-lyase activities. These functions determine the ability of adrenal glands and gonads to synthesize 17alpha-hydroxylated glu

  12. Resting-state beta and gamma activity in Internet addiction.

    Science.gov (United States)

    Choi, Jung-Seok; Park, Su Mi; Lee, Jaewon; Hwang, Jae Yeon; Jung, Hee Yeon; Choi, Sam-Wook; Kim, Dai Jin; Oh, Sohee; Lee, Jun-Young

    2013-09-01

    Internet addiction is the inability to control one's use of the Internet and is related to impulsivity. Although a few studies have examined neurophysiological activity as individuals with Internet addiction engage in cognitive processing, no information on spontaneous EEG activity in the eyes-closed resting-state is available. We investigated resting-state EEG activities in beta and gamma bands and examined their relationships with impulsivity among individuals with Internet addiction and healthy controls. Twenty-one drug-naïve patients with Internet addiction (age: 23.33 ± 3.50 years) and 20 age-, sex-, and IQ-matched healthy controls (age: 22.40 ± 2.33 years) were enrolled in this study. Severity of Internet addiction was identified by the total score on Young's Internet Addiction Test. Impulsivity was measured with the Barratt Impulsiveness Scale-11 and a stop-signal task. Resting-state EEG during eyes closed was recorded, and the absolute/relative power of beta and gamma bands was analyzed. The Internet addiction group showed high impulsivity and impaired inhibitory control. The generalized estimating equation showed that the Internet-addiction group showed lower absolute power on the beta band than did the control group (estimate = -3.370, p Internet addiction as well as with the extent of impulsivity. The present study suggests that resting-state fast-wave brain activity is related to the impulsivity characterizing Internet addiction. These differences may be neurobiological markers for the pathophysiology of Internet addiction.

  13. Heterogeneous expression of cholesterol 7α-hydroxylase and sterol 27- hydroxylase genes in the rat liver lobulus

    NARCIS (Netherlands)

    Twisk, J.; Hoekman, M.F.M.; Mager, W.H.; Moorman, A.F.M.; Boer, P.A.J. de; Scheja, L.; Princen, H.M.G.; Gebhardt, R.

    1995-01-01

    We investigated the lobular localization and molecular level of expression of cholesterol 7α-hydroxylase and sterol 27-hydroxylase, two key enzymes in bile acid synthesis, in isolated periportal and pericentral hepatocytes and by in situ hybridization of rat liver. Enzyme activity, mRNA, and gene tr

  14. Urease inhibitory activities of beta-boswellic acid derivatives

    OpenAIRE

    Reza Hajiaghaee; Behnam Yousefi; Zinat Bahrampour Omrany; Farzaneh Nabati; Sahand Golestanian; Roya Bazl; Sanaz Golbabaei; "Shamsali Rezazadeh; Massoud Amanlou

    2013-01-01

    Background and the purpose of the study: Boswellia carterii have been used in traditional medicine for many years for management different gastrointestinal disorders. In this study, we wish to report urease inhibitory activity of four isolated compound of boswellic acid derivative.Methods 4 pentacyclic triterpenoid acids were isolated from Boswellia carterii and identified by NMR and Mass spectroscopic analysis (compounds 1, 3-O-acetyl-9,11-dehydro-beta-boswellic acid; 2, 3-O-acetyl-11-hydrox...

  15. Biosynthesis of pseudoisoeugenols in tissue cultures of Pimpinella anisum. Phenylalanine ammonia lyase and cinnamic acid 4-hydroxylase activities.

    Science.gov (United States)

    Reichling, J; Kemmerer, B; Sauer-Gürth, H

    1995-07-28

    The genus Pimpinella contains pseudoisoeugenols, phenylpropanoids with a rare 2,5-dioxy substitution pattern on the phenyl ring. To study the biosynthesis of these compounds, we set up a leaf-differentiating tissue culture of Pimpinella anisum. These cultures mainly produce epoxy-pseudoisoeugenol-(2-methylbutyrate). To corroborate the biosynthetic pathway of epoxy-pseudoisoeugenol-(2-methylbutyrate) as proposed on the basis of investigations with 13C/14C-labelled precursors, the key steps of the pathway were investigated at an enzyme level. Experiments with cell-free homogenates clearly revealed that L-phenylalanine is converted to (E)-cinnamic acid by phenylalanine ammonia lyase and that (E)-cinnamic acid is converted to p-coumaric acid by cinnamic acid 4-hydroxylase. L-2-aminooxy-3-phenylpropionic acid, an analogue of L-phenylalanine, inhibited the incorporation of L-[3'-13C]phenylalanine into epoxy-pseudoisoeugenol-(2-methylbutyrate). Up to 2% of the precursor DL-[3'-13C]phenyllactate was incorporated into epoxy-pseudoisoeugenol-(2-methylbutyrate). Inhibition experiments with oxalacetic acid clearly showed that cinnamic acid is not formed by dehydration of phenyllactic acid in this leaf-differentiating tissue culture of P. anisum.

  16. Ablation of PGC-1 beta results in defective mitochondrial activity, thermogenesis, hepatic function, and cardiac performance

    OpenAIRE

    Lelliott, Christopher J.; Gema Medina-Gomez; Natasa Petrovic; Adrienn Kis; Feldmann, Helena M; Mikael Bjursell; Nadeene Parker; Keira Curtis; Mark Campbell; Ping Hu; Dongfang Zhang; Litwin, Sheldon E.; Vlad G Zaha; Fountain, Kimberly T; Sihem Boudina

    2006-01-01

    International audience; The transcriptional coactivator peroxisome proliferator-activated receptor-gamma coactivator-1beta (PGC-1beta) has been implicated in important metabolic processes. A mouse lacking PGC-1beta (PGC1betaKO) was generated and phenotyped using physiological, molecular, and bioinformatic approaches. PGC1betaKO mice are generally viable and metabolically healthy. Using systems biology, we identified a general defect in the expression of genes involved in mitochondrial functio...

  17. Immunohistochemical detection of active transforming growth factor-beta in situ using engineered tissue

    Science.gov (United States)

    Barcellos-Hoff, M. H.; Ehrhart, E. J.; Kalia, M.; Jirtle, R.; Flanders, K.; Tsang, M. L.; Chatterjee, A. (Principal Investigator)

    1995-01-01

    The biological activity of transforming growth factor-beta 1 (TGF-beta) is governed by dissociation from its latent complex. Immunohistochemical discrimination of active and latent TGF-beta could provide insight into TGF-beta activation in physiological and pathological processes. However, evaluation of immunoreactivity specificity in situ has been hindered by the lack of tissue in which TGF-beta status is known. To provide in situ analysis of antibodies to differentiate between these functional forms, we used xenografts of human tumor cells modified by transfection to overexpress latent TGF-beta or constitutively active TGF-beta. This comparison revealed that, whereas most antibodies did not differentiate between TGF-beta activation status, the immunoreactivity of some antibodies was activation dependent. Two widely used peptide antibodies to the amino-terminus of TGF-beta, LC(1-30) and CC(1-30) showed marked preferential immunoreactivity with active TGF-beta versus latent TGF-beta in cryosections. However, in formalin-fixed, paraffin-embedded tissue, discrimination of active TGF-beta by CC(1-30) was lost and immunoreactivity was distinctly extracellular, as previously reported for this antibody. Similar processing-dependent extracellular localization was found with a neutralizing antibody raised to recombinant TGF-beta. Antigen retrieval recovered cell-associated immunoreactivity of both antibodies. Two antibodies to peptides 78-109 showed mild to moderate preferential immunoreactivity with active TGF-beta only in paraffin sections. LC(1-30) was the only antibody tested that discriminated active from latent TGF-beta in both frozen and paraffin-embedded tissue. Thus, in situ discrimination of active versus latent TGF-beta depends on both the antibody and tissue preparation. We propose that tissues engineered to express a specific form of a given protein provide a physiological setting in which to evaluate antibody reactivity with specific functional forms of a

  18. Endocrine expression of the active form of TGF-beta1 in the TGF-beta1 null mice fails to ameliorate lethal phenotype.

    Science.gov (United States)

    Longenecker, Glenn; Thyagarajan, Tamizchelvi; Nagineni, Chandrasekharam N; Flanders, Kathleen C; Factor, Valentina; Miller, Georgina; Ward, Jerrold M; Nalca, Aysegul; Rangnekar, Vivek M; Thorgeirsson, Snorri; Kulkarni, Ashok B

    2002-04-01

    TGF-beta1 null mice die by 3 to 4 weeks of age due to a severe autoimmune-mediated multifocal inflammation resulting in multi-organ failure. To assess the therapeutic potential of circulating levels of active TGF-beta1, we generated mice with endocrine expression of active TGF-beta1 on a TGF-beta1 null background (TGF-beta1 (-/-/TG)) by crossing TGF-beta1(+/-) mice with transgenic mice (TG) that express recombinant TGF-beta1 specifically in the liver and secrete it in the blood. The TGF-beta1 (-/-/TG) mice exhibit a survival profile similar to the TGF-beta1 (-/-) mice indicating a failure to rescue the lethal phenotype. However, serum TGF-beta1 levels in the TGF-beta1 (-/-/TG) mice were restored to near normal levels with expression in all the tissues, notably in the kidney and spleen. Histopathology showed reduced inflammation in the target tissues, especially in the heart. Interestingly, unlike TGF-beta1 (-/-) mice, the TGF-beta1 (-/-/TG) mice have glomerulonephritis in their kidneys similar to the TG mice. Thus, the phenotype of TGF-beta1 (-/-/TG) animal model indicates the potential role of circulating active-TGF-beta1 in reducing inflammation, but its failure to rescue lethality in TGF-beta1 null mice indicates a critical autocrine role of TGF-beta1.

  19. Oxidative Status of DJ-1-dependent Activation of Dopamine Synthesis through Interaction of Tyrosine Hydroxylase and 4-Dihydroxy-l-phenylalanine (l-DOPA) Decarboxylase with DJ-1*

    Science.gov (United States)

    Ishikawa, Shizuma; Taira, Takahiro; Niki, Takeshi; Takahashi-Niki, Kazuko; Maita, Chinatsu; Maita, Hiroshi; Ariga, Hiroyoshi; Iguchi-Ariga, Sanae M. M.

    2009-01-01

    Parkinson disease (PD) is caused by loss of dopamine, which is synthesized from tyrosine by two enzymes, tyrosine hydroxylase (TH) and 4-dihydroxy-l-phenylalanine decarboxylase (DDC). DJ-1 is a causative gene for the familial form of PD, but little is known about the roles of DJ-1 in dopamine synthesis. In this study, we found that DJ-1 directly bound to TH and DDC and positively regulated their activities in human dopaminergic cells. Mutants of DJ-1 found in PD patients, including heterozygous mutants, lost their activity and worked as dominant-negative forms toward wild-type DJ-1. When cells were treated with H2O2, 6-hydroxydopamine, or 1-methyl-4-phenylpyridinium, changes in activities of TH and DDC accompanied by oxidation of cysteine 106 of DJ-1 occurred. It was found that DJ-1 possessing Cys-106 with SH and SOH forms was active and that DJ-1 possessing Cys-106 with SO2H and SO3H forms was inactive in terms of stimulation of TH and DDC activities. These findings indicate an essential role of DJ-1 in dopamine synthesis and contribution of DJ-1 to the sporadic form of PD. PMID:19703902

  20. Hydrolysis and transglycosylation activity of a thermostable recombinant beta-glycosidase from Sulfolobus acidocaldarius.

    Science.gov (United States)

    Park, Ah-Reum; Kim, Hye-Jung; Lee, Jung-Kul; Oh, Deok-Kun

    2010-04-01

    We expressed a putative beta-galactosidase from Sulfolobus acidocaldarius in Escherichia coli and purified the recombinant enzyme using heat treatment and Hi-Trap ion-exchange chromatography. The resultant protein gave a single 57-kDa band by SDS-PAGE and had a specific activity of 58 U/mg. The native enzyme existed as a dimer with a molecular mass of 114 kDa by gel filtration. The maximum activity of this enzyme was observed at pH 5.5 and 90 degrees C. The half-lives of the enzyme at 70, 80, and 90 degrees C were 494, 60, and 0.2 h, respectively. The hydrolytic activity with p-nitrophenyl(pNP) substrates followed the order p-nitrophenyl-beta-D-fucopyranoside > pNP-beta-D-glucopyranoside > pNP-beta-D-galactopyranoside > pNP-beta-D-mannopyranoside > pNP-beta-D-xylopyranoside, but not toward aryl-alpha-glycosides or pNP-beta-L-arabinofuranoside. Thus, the enzyme was actually a beta-glycosidase. The beta-glycosidase exhibited transglycosylation activity with pNP-beta-D-galactopyranoside, pNP-beta-D-glucopyranoside, and pNP-beta-D-fucopyranoside in decreasing order of activity, in the reverse order of its hydrolytic activity. The hydrolytic activity was higher toward cellobiose than toward lactose, but the transglycosylation activity was lower with cellobiose than with lactose.

  1. Expression and enzymatic activity of phenylalanine ammonia-lyase and p-coumarate 3-hydroxylase in mango (Mangifera indica 'Ataulfo') during ripening.

    Science.gov (United States)

    Palafox-Carlos, H; Contreras-Vergara, C A; Muhlia-Almazán, A; Islas-Osuna, M A; González-Aguilar, G A

    2014-05-16

    Phenylalanine ammonia lyase (PAL) and p-coumarate 3-hydroxylase (C3H) are key enzymes in the phenylpropanoid pathway. The relative expression of PAL and C3H was evaluated in mango fruit cultivar 'Ataulfo' in four ripening stages (RS1, RS2, RS3, and RS4) by quantitative polymerase chain reaction. In addition, enzyme activity of PAL and C3H was determined in mango fruits during ripening. The PAL levels were downregulated at the RS2 and RS3 stages, while C3H levels were upregulated in fruits only at RS3. The enzyme activity of PAL followed a pattern that was different from that of the PAL expression, thus suggesting regulation at several levels. For C3H, a regulation at the transcriptional level is suggested because a similar pattern was revealed by its activity and transcript level. In this study, the complexity of secondary metabolite biosynthesis regulation is emphasized because PAL and C3H enzymes are involved in the biosynthesis of several secondary metabolites that are active during all mango ripening stages.

  2. In vitro inhibition of 7-ethoxyresorufin-O-deethylase (EROD) and p-nitrophenol hydroxylase (PNPH) activities by sesamin in hepatic microsomes from two fish species.

    Science.gov (United States)

    Wagner, Liane; Zlabek, Vladimir; Trattner, Sofia; Zamaratskaia, Galia

    2013-01-01

    In the present study, we investigated the effect of sesamin on CYP1A (7-ethoxyresorufin-O-deethylase, EROD) and CYP2E1-like activities (p-nitrophenol hydroxylase, PNPH) in hepatic microsomes obtained from Atlantic salmon (Salmo salar) and common carp (Cyprinus carpio). Addition of sesamin to the incubations in a concentration range from 1 to 200 μM decreased the activities of EROD and PNPH in a concentration dependent manner. It is likely that the inhibition of EROD was mechanism-based as demonstrated by the decrease in the IC50 value from 5.9 to 3.2 μM for A. salmon and from 7.9 to 3.0 μM for common carp when 5 min pre-incubation step was included. Similarly, PNPH activity was inhibited by sesamin with a decrease in the IC50 values from 61.7 to 15.2 μM for A. salmon and from 194.3 to 20.7 μM for common carp. Thus, our results indicated that sesamin can act as a mechanism-based inhibitor of EROD and PNPH activity with similar degree of inhibition in both fish species. More importantly, the inhibition of CYP1A, in addition to being mechanism-based, was competitive with K(i) value of 5.3 μM.

  3. Antidepressant-like action of AGN 2979, a tryptophan hydroxylase activation inhibitor, in a chronic mild stress model of depression in rats.

    Science.gov (United States)

    Gittos, M W; Papp, M

    2001-10-01

    Chronic mild stress (CMS) procedure was used to study an antidepressant-like activity of AGN 2979, a selective inhibitor of tryptophan hydroxylase (TH) activation. At the dose of 4 mg/kg, AGN 2979 fully reversed the CMS-induced reduction in the consumption of 1% sucrose solution. This effect was maintained for at least 1 week after cessation of treatment and no signs of withdrawal were observed in either stressed or control animals receiving AGN 2979. The lower (1 mg/kg) and higher (16 mg/kg) doses were ineffective. The magnitude of action of AGN 2979 in the CMS model was comparable to that of imipramine (10 mg/kg) but its onset of action appears to be faster since the inhibition of sucrose intake in stressed animals was already reversed after the 1st week of AGN 2979 administration while imipramine required 3 weeks of treatment to cause similar effect. These results provide support for the hypothesis that inhibition of TH activation may result in a potent antidepressant activity.

  4. Glucose activates prenyltransferases in pancreatic islet {beta}-cells

    Energy Technology Data Exchange (ETDEWEB)

    Goalstone, Marc [Department of Medicine, University of Colorado, VA Medical Center, Denver, CO 80220 (United States); Kamath, Vasudeva [Department of Pharmaceutical Sciences, Wayne State University, VA Medical Center, Detroit, MI 48201 (United States); Kowluru, Anjaneyulu, E-mail: akowluru@med.wayne.edu [Department of Pharmaceutical Sciences, Wayne State University, VA Medical Center, Detroit, MI 48201 (United States)

    2010-01-01

    A growing body of evidence implicates small G-proteins [e.g., Cdc42 and Rac1] in glucose-stimulated insulin secretion [GSIS] in the islet {beta}-cell. These signaling proteins undergo post-translational modifications [e.g., prenylation] at their C-terminal cysteine residue and appear to be essential for the transport and fusion of insulin-containing secretory granules with the plasma membrane and the exocytotic secretion of insulin. However, potential regulation of the prenylating enzymes by physiological insulin secretogues [e.g., glucose] has not been investigated thus far. Herein, we report immunological localization, sub-cellular distribution and regulation of farnesyltransferases [FTases] and geranylgeranyltransferase [GGTase] by glucose in insulin-secreting INS 832/13 {beta}-cells and normal rat islets. Our findings suggest that an insulinotropic concentration of glucose [20 mM] markedly stimulated the expression of the {alpha}-subunits of FTase/GGTase-1, but not the {beta}-subunits of FTase or GGTase-1 without significantly affecting the predominantly cytosolic distribution of these holoenzymes in INS 832/13 cells and rodent islets. Under these conditions, glucose significantly stimulated [2.5- to 4.0-fold over basal] the activities of both FTase and GGTase-1 in both cell types. Together, these findings provide the first evidence to suggest that GSIS involves activation of the endogenous islet prenyltransferases by glucose, culminating in the activation of their respective G-protein substrates, which is necessary for cytoskeletal rearrangement, vesicular transport, fusion and secretion of insulin.

  5. Involvement of nitric oxide pathways in short term modulation of tyrosine hydroxylase activity by endothelins 1 and 3 in the rat anterior hypothalamus.

    Science.gov (United States)

    Morgazo, Carolina; Perfume, Guadalupe; Legaz, Guillermina; di Nunzio, Andrea; Hope, Sandra I; Bianciotti, Liliana G; Vatta, Marcelo S

    2005-09-02

    The ability of endothelins 1 and 3 (ET-1 and ET-3) to reduce neuronal norepinephrine release through ETB receptor activation involving nitric oxide (NO) pathways in the rat anterior hypothalamus region (AHR) was previously reported. In the present work, we studied the effects of ET-1 and -3 on tyrosine hydroxylase (TH) activity and the possible involvement of NO pathways. Results showed that ET-1 and -3 (10 nM) diminished TH activity in AHR and this effect was blocked by a selective ETB receptor antagonist (100 nM BQ-788), but not by a ET(A) receptor antagonist (BQ-610). To confirm these results, 1 microM IRL-1620 (ET(B) agonist) reduced TH activity whereas 300 nM sarafotoxin S6b falled to modify it. N(omega)-Nitro-L-arginine methyl ester (10 microM), 7-nitroindazole (10 microM), 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-ona (10 microM), KT5823 (2 microM), inhibitors of nitric oxide synthase, neuronal nitric oxide synthase, NO-sensitive-guanylyl cyclase, and protein kinase G, respectively, did not modify the reduction of TH activity produced by ETs. In addition, both 100 microM sodium nitroprusside and 50 microM 8-bromoguanosine-3',5'-cyclic monophosphate (NO donor and guanosine-3',5'-cyclic monophosphate analog, respectively) diminished TH activity. Present results showed that ET-1 and ET-3 diminished TH activity through the activation of ET(B) receptors involving the NO/guanosine-3',5'-cyclic monophosphate/protein kinase G pathway. Taken jointly present and previous results it can be concluded that both ETs play an important role as modulators of norepinephrine neurotransmission in the rat AHR.

  6. Short-term regulation of tyrosine hydroxylase in tonically-active and in tonically-inactive dopamine neurons: effects of haloperidol and protein phosphorylation.

    Science.gov (United States)

    Iuvone, P M

    1983-09-26

    Dopamine (DA)-containing neurons of retina were employed as an experimental model for studying the short-term regulation of tyrosine hydroxylase (TH) in tonically-active and tonically-inactive neurons. These DA-containing neurons are trans-synaptically activated by light. Two mechanisms have been observed in this system for regulation of TH activity. A short-term activation of TH that is characterized by a decreased apparent Km for pteridine cofactors occurs in response to rapid increases of neuronal activity. A second mechanism occurs in response to prolonged, tonic changes of neuronal activity and is characterized by changes of Vmax. Both the Km changes and Vmax changes represent changes of specific activity of TH rather than enzyme induction. To determine the effects of short-term increases of neuronal activity on TH in tonically-active and tonically-inactive neurons, the effects of acute administration of haloperidol were examined in rats that were continuously light-exposed or light-deprived for 4 days. Haloperidol increased TH activity in both light-exposed and light-deprived retinas. The drug elicited the same percent stimulation in both experimental conditions. However, because the basal activity of TH was higher in the light-exposed than the light-deprived retinas, the absolute increase of TH specific activity was greater in the light-exposed samples. The effect of protein phosphorylation on TH activity in extracts of chronically light-exposed or light-deprived retinas was also examined to determine if the differences in the response to haloperidol might be due to a difference in the amount of TH available for short-term activation. Phosphorylation by endogenous cyclic AMP-dependent protein kinase (APK) or by purified catalytic subunit of APK resulted in larger increases of TH specific activity in extracts of light-exposed retinas than in those of light-deprived retinas. As was observed for haloperidol-induced activation, the percent stimulation elicited

  7. Gross-beta activity in ground water: natural sources and artifacts of sampling and laboratory analysis

    Science.gov (United States)

    Welch, Alan H.

    1995-01-01

    Gross-beta activity has been used as an indicator of beta-emitting isotopes in water since at least the early 1950s. Originally designed for detection of radioactive releases from nuclear facilities and weapons tests, analysis of gross-beta activity is widely used in studies of naturally occurring radioactivity in ground water. Analyses of about 800 samples from 5 ground-water regions of the United States provide a basis for evaluating the utility of this measurement. The data suggest that measured gross-beta activities are due to (1) long-lived radionuclides in ground water, and (2) ingrowth of beta-emitting radionuclides during holding times between collection of samples and laboratory measurements.Although40K and228Ra appear to be the primary sources of beta activity in ground water, the sum of40K plus228Ra appears to be less than the measured gross-beta activity in most ground-water samples. The difference between the contribution from these radionuclides and gross-beta activity is most pronounced in ground water with gross-beta activities > 10 pCi/L, where these 2 radionuclides account for less than one-half the measured ross-beta activity. One exception is groundwater from the Coastal Plain of New Jersey, where40K plus228Ra generally contribute most of the gross-beta activity. In contrast,40K and228Ra generally contribute most of beta activity in ground water with gross-beta activities measure all beta activity in ground water. Although3H contributes beta activity to some ground water, it is driven from the sample before counting and therefore is not detected by gross-beta measurements. Beta-emitting radionuclides with half-lives shorter than a few days can decay to low values between sampling and counting. Although little is known about concentrations of most short-lived beta-emitting radionuclides in environmental ground water (water unaffected by direct releases from nuclear facilities and weapons tests), their activities are expected to be low.Ingrowth of

  8. Antibacterial activity of Beta vulgaris L. pomace extract

    Directory of Open Access Journals (Sweden)

    Velićanski Aleksandra S.

    2011-01-01

    Full Text Available Antibacterial activity of Beta vulgaris L. (beetroot pomace extract (concentration 100 mg/ml was tested against five Gram positive and seven Gram negative bacterial strains (reference cultures and natural isolates. Disc diffusion method with 15 µl of extract and agar-well diffusion method with 50 and 100 µl were used. Antibiotic (cefotaxime/clavulanic acid was used as a control sample. The tested extract showed the highest activity against Staphylococcus aureus and Bacillus cereus, where clear zones (without growth appeared. There was no any activity against other tested Gram-positive bacteria, except for Staphylococcus epidermidis, with a small zone of reduced growth. Growth of all tested Gram-negative bacteria was inhibited usually with 100 µl of extract. The most susceptible were Citrobacter freundii and Salmonella typhymurium. The tested antibiotic gave clear, usually large zones for all tested strains except for Staphylococcus cohni spp. cohni, where only a zone of reduced growth appeared.

  9. The tryptophan hydroxylase activation inhibitor, AGN-2979, decreases regional 5-HT synthesis in the rat brain measured with alpha-[14C]methyl-L-tryptophan: an autoradiographic study.

    Science.gov (United States)

    Hasegawa, Shu; Kanemaru, Kazuya; Gittos, Maurice; Diksic, Mirko

    2005-10-15

    Many experimental conditions are stressful for animals. It is well known that stress induces tryptophan hydroxylase (TPH) activation, resulting in increased serotonin (5-HT) synthesis. In our experimental procedure to measure 5-HT synthesis using alpha-[(14)C]methyl-L-tryptophan (alpha-MTrp) autoradiographic method, the hind limbs of animals are restrained using a loose-fitted plaster cast such that the forelimbs of the animal remain free. The objective of the present investigation was to evaluate the changes, if any, in 5-HT synthesis, after injecting these restrained rats with the TPH activation inhibitor AGN-2979. The effect on regional 5-HT synthesis was studied using the alpha-MTrp autoradiographic method. The hypothesis was that the TPH activation inhibitor would reduce 5-HT synthesis, if TPH activation was induced by this restraint. The rats received injection of AGN-2979 (10 mg/kg, i.p.) or distilled water vehicle (1 mL/kg, i.p.) 1 h prior to tracer administration. The free- and total tryptophan concentrations were not significantly different between the treatment and control groups. The results demonstrate that 5-HT synthesis in AGN-2979 treated rats is significantly decreased (-12 to -35%) in both the raphe nuclei and their terminal areas when compared to the control rats. These findings suggest that restrained conditions, such as those used in our experimental protocol, induce TPH activation resulting in an increased 5-HT synthesis throughout the brain. The reduction in 5-HT synthesis in the AGN-2979 group is not related to a change in the plasma tryptophan. Because there was no activation in the pineal body, the structure having a different isoform of TPH, we can propose that it is only the brain TPH that becomes activated with this specific restraint.

  10. Study of RNA interference inhibiting rat ovarian androgen biosynthesis by depressing 17alpha-hydroxylase/17, 20-lyase activity in vivo

    Directory of Open Access Journals (Sweden)

    Yang Xing

    2009-07-01

    Full Text Available Abstract Background 17alpha-hydroxylase/17, 20-lyase encoded by CYP17 is the key enzyme in androgen biosynthesis pathway. Previous studies demonstrated the accentuation of the enzyme in patients with polycystic ovary syndrome (PCOS was the most important mechanism of androgen excess. We chose CYP17 as the therapeutic target, trying to suppress the activity of 17alpha-hydroxylase/17, 20-lyase and inhibit androgen biosynthesis by silencing the expression of CYP17 in the rat ovary. Methods Three CYP17-targeting and one negative control oligonucleotides were designed and used in the present study. The silence efficiency of lentivirus shRNA was assessed by qRT-PCR, Western blotting and hormone assay. After subcapsular injection of lentivirus shRNA in rat ovary, the delivery efficiency was evaluated by GFP fluorescence and qPCR. Total RNA was extracted from rat ovary for CYP17 mRNA determination and rat serum was collected for hormone measurement. Results In total, three CYP17-targeting lentivirus shRNAs were synthesized. The results showed that all of them had a silencing effect on CYP17 mRNA and protein. Moreover, androstenedione secreted by rat theca interstitial cells (TIC in the RNAi group declined significantly compared with that in the control group. Two weeks after rat ovarian subcapsular injection of chosen CYP17 shRNA, the GFP fluorescence of frozen ovarian sections could be seen clearly under fluorescence microscope. It also showed that the GFP DNA level increased significantly, and its relative expression level was 7.42 times higher than that in the control group. Simultaneously, shRNA treatment significantly decreased CYP17 mRNA and protein levels at 61% and 54%, respectively. Hormone assay showed that all the levels of androstenedione, 17-hydroxyprogesterone and testosterone declined to a certain degree, but progesterone levels declined significantly. Conclusion The present study proves for the first time that ovarian androgen

  11. Intracerebroventricular administration of ouabain, a Na/K-ATPase inhibitor, activates tyrosine hydroxylase through extracellular signal-regulated kinase in rat striatum.

    Science.gov (United States)

    Yu, Hyun Sook; Kim, Se Hyun; Park, Hong Geun; Kim, Yong Sik; Ahn, Yong Min

    2011-11-01

    Alteration in dopamine neurotransmission has been reported to be involved in the mania of bipolar disorder. Tyrosine hydroxylase (TH) is the rate-limiting enzyme that is crucial for dopamine biosynthesis, and its activity is tightly regulated by phosphorylation at multiple N-terminal serine residues. Previously, we have reported that intracerebroventricular (ICV) injection of ouabain, a selective Na/K-ATPase inhibitor, induces hyperactivity in rats that mimics manic symptoms related to the activation of extracellular signal-regulated protein kinase1/2 (ERK1/2), which plays crucial roles in the modulation of TH phosphorylation. In this study, we investigated the effects of ICV injection of ouabain on TH phosphorylation in rat striatum and the involvement of ERK1/2 in ouabain-induced TH activation. ICV ouabain induced an acute dose-dependent increase in locomotor activity and in TH phosphorylation in rat striatum. TH phosphorylation at Ser19 was significantly increased with 100, 500, and 1000μM ouabain, and phosphorylation at Ser31 and Ser40 was significantly increased with 500 and 1000μM. We also found that ICV pretreatment with U0126, a specific MEK1/2 inhibitor, attenuated the 1000μM ouabain-induced increase in TH phosphorylation at Ser19, Ser31, and Ser40, as well as the hyperactivity of rats. Moreover, the increased phosphorylation of TH (Ser19, Ser31, and Ser40) was maintained until 8h after single administration ouabain was accompanied by increased phosphorylation of ERK1/2 (Thr202/Tyr204) and p90RSK (Thr359/Ser363). These findings imply that TH activation of the ERK1/2 signal pathway could play an important role in ouabain-induced hyperactivity of rats, a mania model.

  12. Systemic lupus erythematosus activity and beta two microglobulin levels

    Directory of Open Access Journals (Sweden)

    Thelma Larocca Skare

    Full Text Available CONTEXT AND OBJECTIVE: Systemic lupus erythematosus (SLE is an autoimmune disease with a cyclical clinical course. Evaluation of the clinical activity of this disease is important for choosing the correct treatment. The objective of this study was to analyze the value of beta-2 microglobulin (β2M serum levels in determining SLE clinical activity.DESIGN AND SETTING: Cross-sectional analytical study conducted at the rheumatology outpatient clinic of a private university hospital.METHODS: 129 SLE patients were studied regarding disease activity using SLEDAI (SLE Disease Activity Index and cumulative damage using SLICC ACR (SLE International Collaborating Clinics/American College of Rheumatology Damage Index for SLE. At the same time, the β2M serum level, ESR (erythrocyte sedimentation rate, anti-dsDNA (anti-double-stranded DNA and C3 and C4 complement fractions were determined.RESULTS: β2M levels correlated positively with SLEDAI (P = 0.02 and ESR (P = 0.0009 and negatively with C3 (P = 0.007. Patients who were positive for anti-dsDNA had higher β2M serum levels (P = 0.009.CONCLUSION: β2M levels are elevated in SLE patients with active disease.

  13. Beta-glucosidase enzymatic activity of crystal polypeptide of the Bacillus thuringiensis strain 1.1.

    Science.gov (United States)

    Papalazaridou, A; Charitidou, L; Sivropoulou, A

    2003-01-01

    The crystals of Bacillus thuringiensis strain 1.1 consist of the 140 kDa delta-endotoxin, which exhibits beta-glucosidase enzymatic activity, based on the following data. (i) Purified crystals exhibit beta-glucosidase enzymatic activity. When the crystals are reacted with specific antibodies directed either against the commercial (almond purified) beta-glucosidase or against the 140 kDa polypeptide, then considerable reduction of enzymatic activity is observed almost at the same level with both antibodies. (ii) Commercial beta-glucosidase and the 140 kDa crystal polypeptide share antigenic similarities; in Western immunoblots, the 140 kDa crystal polypeptide is recognized by anti-beta-glucosidase antibodies, and commercial beta-glucosidase is recognized by anti-140-kDa antibodies. (iii) The enzymatic properties of commercial beta-glucosidase and that resident in the crystals of B. thuringiensis strain 1.1 are very similar. Thus, both enzymes hydrolyze a wide range of substrates (aryl-beta-glucosides, disaccharides with alpha- or beta-linkage polysaccharides) and have an optimum activity at 40 degrees C and pH 5. Both enzymes are relatively thermostable and are resistant to end-product inhibition by glucose. Additionally, they show the same pattern of inhibition or activation by several chemical compounds. (iv) The crystals and commercial beta-glucosidase show almost equivalent levels of insecticidal activity against Drosophila melanogaster larvae and, furthermore, cause reduction in adult flies that emerge from larvae surviving treatment.

  14. Experimentally calibrated computational chemistry of tryptophan hydroxylase: Trans influence, hydrogen-bonding, and 18-electron rule govern O-2-activation

    DEFF Research Database (Denmark)

    Haahr, Lærke Tvedebrink; Kepp, Kasper Planeta; Boesen, Jane

    2010-01-01

    a two-state scenario involving Ohis and Pglu is possible. A structure of the activated deoxy state which is high-spin implies that the valence electron count has been lowered from 18 to 16 (glutamate becomes bidentate), giving a “green light” that invites O2-binding. Our mechanism of oxygen activation...

  15. Vasoactive intestinal peptide-induced expression of cytochrome P450 cholesterol side-chain cleavage and 17 alpha-hydroxylase enzyme activity in hen granulosa cells.

    Science.gov (United States)

    Johnson, A L; Li, Z; Gibney, J A; Malamed, S

    1994-08-01

    Experiments were conducted to determine whether vasoactive intestinal peptide (VIP) can regulate expression of cytochrome P450 side-chain cleavage (P450scc) and P450 17 alpha-hydroxylase (P450 17 alpha-OH) mRNA levels and enzyme activity in granulosa cells from nonhierarchal (6-8-mm) follicles. Initial studies demonstrated that immunoreactive VIP is localized within the theca (but not granulosa) layer of both resting (< 0.5-mm follicles) and 6-8-mm follicles, thus providing a potential paracrine mechanism of action for VIP. While short-term (3 h) incubation of granulosa cells with VIP (0.001-1.0 microM) failed to stimulate progesterone production from 6-8-mm follicle granulosa cells, a 4-h culture period in the presence of VIP resulted in increased cyclic AMP (cAMP) accumulation, and a 24-h culture period resulted in progesterone synthesis and increased P450scc mRNA levels; control levels of each endpoint measurement were not altered within the period observed. By contrast, culture with the growth factor transforming growth factor alpha (TGF alpha) in the presence of VIP (1 microM) prevented increases in P450scc mRNA levels and progesterone production. Similar effects of VIP and TGF alpha in the presence of VIP were demonstrated for P450 17 alpha-OH mRNA levels and enzyme activity. Finally, there was an additive effect of VIP (0.1 microM) plus recombinant human (rh) FSH (100 mIU) on the initiation of progesterone production in cultured 6-8-mm follicle granulosa cells compared to the addition of VIP or rhFSH alone.(ABSTRACT TRUNCATED AT 250 WORDS)

  16. A Sensitive Method Using 4-Methylumbelliferyl-(beta)-Cellobiose as a Substrate To Measure (1,4)-(beta)-Glucanase Activity in Sediments

    NARCIS (Netherlands)

    Boschker, H.T.S.; Cappenberg, T.E.

    1994-01-01

    A sensitive method to measure (1,4)-beta-glucanase activity in organic matter-rich sediments, using 4-methylumbelliferyl-beta- cellobiose as a substrate, is described. beta-Glucosidases, which were also able to hydrolyze this substrate, were inhibited with D-glucono-delta-lactone. The produced 4- me

  17. Liver-specific activities of FGF19 require Klotho beta.

    Science.gov (United States)

    Lin, Benjamin C; Wang, Manping; Blackmore, Craig; Desnoyers, Luc R

    2007-09-14

    Hepatocyte function is regulated by members of the fibroblast growth factor (FGF) family of proteins, but little is known about the specific molecular mechanisms of this endocrine pathway. FGF19 regulates bile acid homeostasis and gall bladder filling; FGF19 binds only to FGF receptor 4 (FGFR4), but its liver-specific activity cannot be explained solely by the distribution of this receptor. Although it has been suggested that Klotho beta (KLB) may have a role in mediating FGF19 activity, we have provided for the first time definitive evidence that KLB is required for FGF19 binding to FGFR4, intracellular signaling, and downstream modulation of gene expression. We have shown that FGFR4 is widely distributed in mouse, whereas KLB distribution is more restricted. Liver was the only organ in which both genes were abundantly expressed. We show that in mice, FGF19 injection triggers liver-specific induction of c-Fos and repression of CYP7A1. The tissue-specific activity of FGF19 supports the unique intersection of KLB and FGFR4 distribution in liver. These studies define KLB as a novel FGFR4 coreceptor required for FGF19 liver specific functions.

  18. Evidence for auto/paracrine actions of vitamin D in bone: 1α-Hydroxylase expression and activity in human bone cells

    NARCIS (Netherlands)

    M. van Driel (Marjolein); M. Koedam (Marijke); C.J. Buurman (Cok); M. Hewison; H. Chiba (Hideki); A.G. Uitterlinden (André); H.A.P. Pols (Huib); J.P.T.M. van Leeuwen (Hans)

    2006-01-01

    textabstractVitamin D is an important regulator of mineral homeostasis and bone metabolism. 1α-Hydroxylation of 25-(OH)D3 to form the bioactive vitamin D hormone, 1α,25-(OH)2D3, is classically considered to take place in the kidney. However, 1α-hydroxylase has been reported at extrarenal sites. Whet

  19. Screening of some medicinal plants from cameroon for beta-lactamase inhibitory activity.

    Science.gov (United States)

    Gangoué-Piéboji, Joseph; Baurin, Stéphane; Frère, Jean-Marie; Ngassam, Pierre; Ngameni, Bathelemy; Azebaze, Anatole; Pegnyemb, Dieudonné Emmanuel; Watchueng, Jean; Goffin, Colette; Galleni, Moreno

    2007-03-01

    In efforts to find new bioactive beta-lactamase inhibitors, this study investigated 16 Cameroonian plants belonging to 10 families which were evaluated for anti-beta-lactamase activity. The investigation showed that extracts 2, 6, 3 and 5 of the 16 plants investigated presented interesting in vitro beta-lactamase inhibition (over 90%), respectively, of the beta-lactamases TEM-1, OXA-10, IMP-1 and P99. These extracts were from Mammea africana (all beta-lactamases), Garcinia lucida, G. kola (OXA-10, IMP-1 and P99), Bridelia micrantha (OXA-10, P99), Ochna afzelii (OXA-10, P99), Prunus africana (IMP-1) and Adenia lobata (TEM-1). After elimination of tannins (according to the European Pharmacopoeia) the extracts from B. micrantha, G. lucida and M. africana were tested further for their anti-beta-lactamase activity. The extracts from B. micrantha and G. lucida exhibited potent inhibitory activity, respectively, of beta-lactamase OXA-10 (IC(50) = 0.02 mg/mL) and P99 (IC(50) = 0.01 mg/mL). The anti-beta-lactamase activity of M. africana extract was weak. The isolation and the structural elucidation of the active constituents of G. lucida and B. micrantha will provide useful leads in the development of beta-lactamase inhibitors.

  20. Angiotensin administration stimulates renal 11 beta-hydroxysteroid dehydrogenase activity in healthy men

    NARCIS (Netherlands)

    Kerstens, MN; van der Kleij, FGH; Boonstra, AH; Sluiter, WJ; van der Molen, JC; Navis, G; Dullaart, RPF

    2004-01-01

    Background. We examined whether acute administration of angiotensin modulates the activity of 11beta-hydroxysteroid dehydrogenase (11betaHSD), the intracellular enzyme catalyzing the interconversion between the hormonally active cortisol and inactive cortisone. Methods. Twenty-one male healthy subje

  1. Characterisation of two novel CYP4 genes from the marine polychaete Nereis virens and their involvement in pyrene hydroxylase activity

    DEFF Research Database (Denmark)

    Jørgensen, Anne; Rasmussen, Lene Juel; Andersen, Ole

    2005-01-01

    Cytochrome P450 enzymes (CYP enzymes) catalyse the initial step in biotransformation of xenobiotics like polycyclic aromatic hydrocarbons (PAHs). The marine polychaete Nereis virens has a high capacity for biotransformation of PAHs. In the present study, the complete cDNA sequences of two novel CYP....... Both CYP enzymes had monooxygenase activity and catalysed hydroxylation of pyrene to 1-hydroxypyrene. Based on the present results it is likely that both CYP4BB1 and CYP342A1 are involved in xenobiotic biotransformation. Furthermore, site-directed mutagenesis of the conserved cysteine residue...

  2. Effect of gamma-irradiation on the whitening activity of {beta}-glucan

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jae Hun; Sung, Nak Yun; Jung, Pil Moon; Choi, Jong Il; Kim, Jin Kyu; Lee, Ju Woon [Korea Atomic Energy Research Institute, Jeongeup (Korea, Republic of); Byun, Eui Hong [Chungnam Naitonal University, Daejeon (Korea, Republic of)

    2010-09-15

    This study evaluated the change in whitening activity of {beta}-glucan by gamma-irradiation. Tyrosinase inhibition was significantly increased in the samples with 30, 50, 10 kGy irradiated {beta}-glucan. Melanin synthesis of irradiated {beta}-glucan was measured from B16BL6 melanoma cell line treated with {alpha}-melanin stimulating hormone. Melanin synthesis was increased in the {alpha}-melanin stimulating hormone added group. However, it was decreased in the groups of 30, 50 and 100 kGy gamma-irradiated {beta}-glucan treated with {alpha}-melanin stimulating hormone. These results indicate that gamma irradiated {beta}-glucan may elevate the whitening activity. Therefore, gamma-irradiated {beta}-glucan could be used for nutraceutical foods in cosmetic industry.

  3. Platensimycin activity against mycobacterial beta-ketoacyl-ACP synthases.

    Directory of Open Access Journals (Sweden)

    Alistair K Brown

    Full Text Available BACKGROUND: There is an urgent need for the discovery and development of new drugs against Mycobacterium tuberculosis, the causative agent of tuberculosis, especially due to the recent emergence of multi-drug and extensively-drug resistant strains. Herein, we have examined the susceptibility of mycobacteria to the natural product platensimycin. METHODS AND FINDINGS: We have demonstrated that platensimycin has bacteriostatic activity against the fast growing Mycobacterium smegmatis (MIC = 14 microg/ml and against Mycobacterium tuberculosis (MIC = 12 microg/ml. Growth in the presence of paltensimycin specifically inhibited the biosynthesis of mycolic acids suggesting that the antibiotic targeted the components of the mycolate biosynthesis complex. Given the inhibitory activity of platensimycin against beta-ketoacyl-ACP synthases from Staphylococcus aureus, M. tuberculosis KasA, KasB or FabH were overexpressed in M. smegmatis to establish whether these mycobacterial KAS enzymes were targets of platensimycin. In M. smegmatis overexpression of kasA or kasB increased the MIC of the strains from 14 microg/ml, to 30 and 124 microg/ml respectively. However, overexpression of fabH on did not affect the MIC. Additionally, consistent with the overexpression data, in vitro assays using purified proteins demonstrated that platensimycin inhibited Mt-KasA and Mt-KasB, but not Mt-FabH. SIGNIFICANCE: Our results have shown that platensimycin is active against mycobacterial KasA and KasB and is thus an exciting lead compound against M. tuberculosis and the development of new synthetic analogues.

  4. Adaptive grip force is modulated by subthalamic beta activity in Parkinson's disease patients

    Directory of Open Access Journals (Sweden)

    Lukas L. Imbach

    2015-01-01

    Conclusion: The time-locked suppression of beta oscillatory activity in the STN is in line with previous reports of beta ERD prior to voluntary movements. Our results show that the STN is involved in anticipatory grip force control in PD patients. The difference in the phasic beta ERD between the two tasks and the reduction of cortico-subthalamic synchronization suggests that qualitatively different neuronal network states are involved in different grip force control tasks.

  5. miR-190 Enhances HIF-Dependent Responses to Hypoxia in Drosophila by Inhibiting the Prolyl-4-hydroxylase Fatiga.

    Science.gov (United States)

    De Lella Ezcurra, Ana Laura; Bertolin, Agustina Paola; Kim, Kevin; Katz, Maximiliano Javier; Gándara, Lautaro; Misra, Tvisha; Luschnig, Stefan; Perrimon, Norbert; Melani, Mariana; Wappner, Pablo

    2016-05-01

    Cellular and systemic responses to low oxygen levels are principally mediated by Hypoxia Inducible Factors (HIFs), a family of evolutionary conserved heterodimeric transcription factors, whose alpha- and beta-subunits belong to the bHLH-PAS family. In normoxia, HIFα is hydroxylated by specific prolyl-4-hydroxylases, targeting it for proteasomal degradation, while in hypoxia the activity of these hydroxylases decreases due to low oxygen availability, leading to HIFα accumulation and expression of HIF target genes. To identify microRNAs required for maximal HIF activity, we conducted an overexpression screen in Drosophila melanogaster, evaluating the induction of a HIF transcriptional reporter. miR-190 overexpression enhanced HIF-dependent biological responses, including terminal sprouting of the tracheal system, while in miR-190 loss of function embryos the hypoxic response was impaired. In hypoxic conditions, miR-190 expression was upregulated and required for induction of HIF target genes by directly inhibiting the HIF prolyl-4-hydroxylase Fatiga. Thus, miR-190 is a novel regulator of the hypoxia response that represses the oxygen sensor Fatiga, leading to HIFα stabilization and enhancement of hypoxic responses.

  6. Identification of thermostable beta-xylosidase activities produced by Aspergillus brasiliensis and Aspergillus niger

    DEFF Research Database (Denmark)

    Pedersen, Mads; Lauritzen, H.K.; Frisvad, Jens Christian

    2007-01-01

    Twenty Aspergillus strains were evaluated for production of extracellular cellulolytic and xylanolytic activities. Aspergillus brasiliensis, A. niger and A. japonicus produced the highest xylanase activities with the A. brasiliensis and A. niger strains producing thermostable beta...

  7. Use of surface plasmon resonance for real-time measurements of the global conformational transition in human phenylalanine hydroxylase in response to substrate binding and catalytic activation.

    Science.gov (United States)

    Flatmark, T; Stokka, A J; Berge, S V

    2001-07-15

    In the present study the optical biosensor technique, based on the surface plasmon resonance (SPR) phenomenon, was used for real-time measurements of the reversible binding of the pterin cofactor (6R)-l-erythro-5,6,7,8-tetrahydrobiopterin (BH(4)) and l-phenylalanine (l-Phe) to human phenylalanine hydroxylase (hPAH). When BH(4) (241 Da) was injected over the sensor chip with immobilized tetrameric wt-hPAH a positive DeltaRU response was observed with a square-wave type of sensorgram and a saturable response (about 25 RU/(pmol subunit/mm(2)) with a [S](0.5) value of 5.6 +/- 0.8 microM for the pterin cofactor. The rapid on-and-off rates were, however, not possible to determine. By contrast, when l-Phe (165 Da) was injected a time-dependent increase in RU (up to about 3 min) and a much higher saturable DeltaRU response (about 75 RU/(pmol subunit/mm(2)) at 2 mM l-Phe) than expected (i.e., <5 RU/(pmol subunit/mm(2))) from the low molecular mass of l-Phe were observed in the sensorgram. The half-time for the on-and-off rates were 6 +/- 2 and 9 +/- 1 s, respectively, at 2 mM l-Phe. The steady-state (apparent equilibrium) response revealed a hyperbolic concentration dependence with a [S](0.5) value of 98 +/- 7 microM. The [S](0.5) values of both pterin cofactor and l-Phe were lower than those determined by steady-state enzyme kinetic analysis. Evidence is presented that the DeltaRU response to l-Phe is accounted for by the global conformational transition which occurs in the enzyme upon l-Phe binding, i.e., by the slow reversible transition from a low activity state ("T"-state) to a high activity state ("R"-state) characteristic of this hysteretic enzyme.

  8. Regulation by retinoids of luteinizing hormone/chorionic gonadotropin receptor, cholesterol side-chain cleavage cytochrome P-450, 3 beta-hydroxysteroid dehydrogenase/delta (5-4)-isomerase and 17 alpha-hydroxylase/C17-20 lyase cytochrome P-450 messenger ribonucleic acid levels in the K9 mouse Leydig cell line.

    Science.gov (United States)

    Lefèvre, A; Rogier, E; Astraudo, C; Duquenne, C; Finaz, C

    1994-12-01

    Vitamin A is a potent regulator of testicular function. We have reported that retinol (R) and retinoic acid (RA) induced a down regulation of luteinizing hormone/human chorionic gonadotropin (LH/CG) binding sites in K9 Leydig cells. In the present study we evaluated the effect of R and RA on LH/CG receptors, cholesterol side-chain cleavage cytochrome P-450 (P-450 scc), 17 alpha-hydroxylase/C17-20 lyase (P-450 17 alpha) and 3 beta-hydroxysteroid dehydrogenase (3 beta HSD) mRNA levels in K9 mouse Leydig cells. To validate K9 cells as a model for studying Leydig cell steroidogenesis at the molecular level, we first investigated the effect of hCG on mRNA levels of the steroidogenic enzymes. P-450 scc, 3 beta HSD and P-450 17 alpha were expressed constitutively. The addition of 10 ng/ml hCG enhanced mRNA levels for the three genes within 2 h. Maximal accumulation of P-450 scc, P-450 17 alpha and 3 beta HSD mRNA in treated cells represents a 2.5-, 8.5- and 4-fold increase over control values, respectively. P-450 17 alpha expression reached a maximum by 4 h and then declined rapidly to return to control value by 24 h. The pattern of LH/CG receptor mRNAs in K9 cells was very similar to that of MA10 Leydig cells and showed six transcripts of 1.1, 1.6, 1.9, 2.6, 4.2 and 7.0 kb. Treatment of cells with R or RA resulted in a time- and dose-dependent decrease in all six species.(ABSTRACT TRUNCATED AT 250 WORDS)

  9. [Medullary layer activity of the rat adrenals after a flight on the Kosmos-1129 biosatellite].

    Science.gov (United States)

    Kvetnanský, R; Blazicek, P; Tigranian, R A

    1982-01-01

    After a 18.5-day space flight on Cosmos-1129 rat adrenals were investigated for the concentration of catecholamines and activity of enzymes involved in their synthesis, i.e. tyrosine hydroxylase, dopamine-beta-hydroxylase, and phenyl ethanol amine-N-methyl transferase. It was found that inflight the sympatho-adreno-medullary system of rats was not exposed to a prolonged or strong stressogenic effect. Postflight the rats showed an increased reactivity to the immobilization stress.

  10. The in-vitro antimicrobial activity of some medicinal plants against beta-lactam-resistant bacteria

    OpenAIRE

    Gangoue Pieboji, Joseph; Eze, N.; Ngongang Djintchui, A.; Ngameni, B; Tsabang, N.; Pegnyemb, D. E.; Biyiti, L.; Ngassam, P.; Koulla-Shiro, S.; Galleni, Moreno

    2009-01-01

    BACKGROUND: In effort to identify novel bacterial agents, this study was initiated to evaluate the antimicrobial properties of 17 crude extracts from 12 medicinal plants against beta-lactam-resistant bacteria. METHODOLOGY: The antimicrobial activities of plant extracts were evaluated against clinically proved beta-lactam-resistant bacteria (Klebsiella pneumoniae, Klebsiella oxytoca, Enterobacter cloacae, Serratia marcescens, Acinetobacter baumannii, Staphylococcus aureus and Enterococcus sp.)...

  11. A comparison of the activities of three beta-galactosidases in aqueous-organic solvent mixtures

    NARCIS (Netherlands)

    Yoon, JH; Mckenzie, D

    2005-01-01

    The hydrolytic activities of beta-galactosidases from three different sources have been determined in various 50% (v/v) organic solvent-buffer mixtures with a view to finding solvent systems of reduced water content suitable for the synthesis of glycosides and oligosaccharides. K. fragilis beta-gala

  12. Identification of (beta-carboxyethyl)-rhodanine derivatives exhibiting peroxisome proliferator-activated receptor gamma activity.

    Science.gov (United States)

    Choi, Jiwon; Ko, Yoonae; Lee, Hui Sun; Park, Yun Sun; Yang, Young; Yoon, Sukjoon

    2010-01-01

    We applied an improved virtual screening scheme combining ligand-centric and receptor-centric methods for the identification of a new series of PPARgamma agonists known as (beta-carboxyethyl)-rhodanine derivatives which include a thiazolidin-based core structure, 2-thioxo-thiazolidine-4-one. An in vitro assay confirmed the nanomolar binding affinity in one of the (beta-carboxyethyl)-rhodanine derivatives, SP1818. It showed a PPARgamma agonistic activity similar to that of a known PPARgamma drug, pioglitazone, in a cell-based transactivation assay. Furthermore, the structure-activity relationships of the rhodanine derivatives were investigated through comparative molecular field analysis. We also characterized the inconsistency between the in vitro binding affinity and cell-based transactivation ability by using a set of property-based molecular descriptors. The binding mode analysis provided new insight concerning their agonistic effect on PPARgamma.

  13. The time-course of hindbrain neuronal activity varies according to location during either intraperitoneal or subcutaneous tumor growth in rats: single Fos and dual Fos/dopamine β-hydroxylase immunohistochemistry.

    Science.gov (United States)

    Lackovicova, Lubica; Gaykema, Ronald P; Banovska, Lucia; Kiss, Alexander; Goehler, Lisa E; Mravec, Boris

    2013-07-15

    Neuronal activity in the nucleus of the solitary tract, ventrolateral medulla, area postrema, and parabrachial nucleus was studied in rats with intraperitoneal or subcutaneous tumors on the 7th, 14th, 21st, and 28th day after injection of fibrosarcoma tumor cells. We found that the number of Fos and dopamine β-hydroxylase immunopositive neurons differs between animals with intraperitoneal and subcutaneous tumors and also between tumor-bearing rats at different times following injection. Our data indicate that responses of the brainstem structures to peripheral tumor growth depend on the localization as well as the stage of the tumor growth.

  14. The phylogeny of the aromatic amino acid hydroxylases revisited by characterizing phenylalanine hydroxylase from Dictyostelium discoideum.

    Science.gov (United States)

    Siltberg-Liberles, Jessica; Steen, Ida Helene; Svebak, Randi M; Martinez, Aurora

    2008-12-31

    The social amoeba Dictyostelium discoideum contains only one aromatic amino acid hydroxylase (AAAH) gene compared to at least three in metazoans. As shown in this work this gene codes for a phenylalanine hydroxylase (DictyoPAH) and phylogenetic analysis places this enzyme close to the precursor AAAHs, aiding to define the evolutionary history of the AAAH family. DictyoPAH shows significant similarities to other eukaryote PAH, but it exhibits higher activity with tetrahydrodictyopterin (DH4) than with tetrahydrobiopterin (BH4) as cofactor. DH4 is an abundant tetrahydropterin in D. discoideum while BH4 is the natural cofactor of the AAAHs in mammals. Moreover, DictyoPAH is devoid of the characteristic regulatory mechanisms of mammalian PAH such as positive cooperativity for L-Phe and activation by preincubation with the substrate. Analysis of the few active site substitutions between DictyoPAH and mammalian PAH, including mutant expression analysis, reveals potential structural determinants for allosteric regulation.

  15. Selective activation of beta3-adrenoceptors by octopamine: comparative studies in mammalian fat cells.

    Science.gov (United States)

    Carpéné, C; Galitzky, J; Fontana, E; Atgié, C; Lafontan, M; Berlan, M

    1999-04-01

    Numerous synthetic agonists selectively stimulate beta3-adrenoceptors (ARs). The endogenous catecholamines, noradrenaline and adrenaline, however, stimulate all the beta-AR subtypes, and no selective physiological agonist for beta3-ARs has been described so far. The aim of this study was to investigate whether any naturally occurring amine can stimulate selectively beta3-ARs. Since activation of lipolysis is a well-known beta-adrenergic function, the efficacy and potency of various biogenic amines were compared with those of noradrenaline, isoprenaline, and beta3-AR agonists 4-(-{[2-hydroxy-(3-chlorophenyl)ethyl]-amino} propyl)phenoxyacetate (BRL 37,344) and (R,R)-5-(2-{[2-(3-chlorophenyl )-2-hydroxyethyl]-amino} propyl)-1,3-benzo-dioxole-2,2-dicarboxylate (CL 316,243) by testing their lipolytic action in white fat cells. Five mammalian species were studied: rat, hamster and dog, in which selective beta-AR agonists act as full lipolytic agents, and guinea-pigs and humans, in which beta3-AR agonists are less potent activators of lipolysis. Several biogenic amines were inefficient (e.g. dopamine, tyramine and beta-phenylethylamine) while others (synephrine, phenylethanolamine, epinine) were partially active in stimulating lipolysis in all species studied. Their actions were inhibited by all the beta-AR antagonists tested, including those selective for beta1- or beta2-ARs. Octopamine was the only amine fully stimulating lipolysis in rat, hamster and dog fat cells, while inefficient in guinea-pig or human fat cells, like the beta3-AR agonists. In rat white fat cells, beta-AR antagonists inhibited the lipolytic effect of octopamine with a relative order of potency very similar to that observed against CL 316,243. Competitive antagonism of octopamine effect resulted in the following apparent pA2 [-log(IC50), where IC50 is the antagonist concentration eliciting half-maximal inhibition] values: 7.77 (bupranolol), 6.48 [3-(2-ethyl-phenoxy)-1[(1 S)-1,2,3,4-tetrahydronaphth-1

  16. A 2-oxoglutarate-dependent dioxygenase from Ruta graveolens L. exhibits p-coumaroyl CoA 2'-hydroxylase activity (C2'H): a missing step in the synthesis of umbelliferone in plants.

    Science.gov (United States)

    Vialart, Guilhem; Hehn, Alain; Olry, Alexandre; Ito, Kyoko; Krieger, Celia; Larbat, Romain; Paris, Cedric; Shimizu, Bun-Ichi; Sugimoto, Yukihiro; Mizutani, Masaharu; Bourgaud, Frederic

    2012-05-01

    Coumarins are important compounds that contribute to the adaptation of plants to biotic or abiotic stresses. Among coumarins, umbelliferone occupies a pivotal position in the plant phenylpropanoid network. Previous studies indicated that umbelliferone is derived from the ortho-hydroxylation of p-coumaric acid by an unknown biochemical step to yield 2,4-dihydroxycinnamic acid, which then undergoes spontaneous lactonization. Based on a recent report of a gene encoding a 2-oxoglutarate-dependent dioxygenase from Arabidopsis thaliana that exhibited feruloyl CoA 6'-hydroxylase activity (Bourgaud et al., 2006), we combined a bioinformatic approach and a cDNA library screen to identify an orthologous ORF (Genbank accession number JF799117) from Ruta graveolens L. This ORF shares 59% amino acid identity with feruloyl CoA 6'-hydroxylase, was functionally expressed in Escherichia coli, and converted feruloyl CoA into scopoletin and p-coumaroyl CoA into umbelliferone with equal activity. Its bi-functionality was further confirmed in planta: transient expression of JF799117 in Nicotiana benthamiana yielded plants with leaves containing high levels of umbelliferone and scopoletin when compared to control plants, which contained barely detectable traces of these compounds. The expression of JF799117 was also tightly correlated to the amount of umbelliferone that was found in UV-elicited R. graveolens leaves. Therefore, JF799117 encodes a p-coumaroyl CoA 2'-hydroxylase in R. graveolens, which represents a previously uncharacterized step in the synthesis of umbelliferone in plants. Psoralen, which is an important furanocoumarin in R. graveolens, was found to be a competitive inhibitor of the enzyme, and it may exert this effect through negative feedback on the enzyme at an upstream position in the pathway.

  17. Immune-enhancing activities of low molecular weight {beta}-glucan depolymerized by gamma irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Sung, Nak-Yun [Team for Radiation Food Science and Biotechnology, Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, Jeongeup 580-185 (Korea, Republic of); Byun, Eui-Hong [Team for Radiation Food Science and Biotechnology, Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, Jeongeup 580-185 (Korea, Republic of); Laboratory of Food Chemistry, Division of Applied Biological Chemistry, Department of Bioscience and Biotechnology, Kyushu University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka, 812-8581 (Japan); Kwon, Sun-Kyu; Song, Beom-Seok; Choi, Jong-il; Kim, Jae-Hun; Byun, Myung-Woo [Team for Radiation Food Science and Biotechnology, Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, Jeongeup 580-185 (Korea, Republic of); Yoo, Young-Choon [Department of Microbiology, College of Medicine, Konyang University, Daejeon 302-718 (Korea, Republic of); Kim, Mee-Ree [Department of Food and Nutrition, Chungnam National University, Daejeon 305-764 (Korea, Republic of); Lee, Ju-Woon [Team for Radiation Food Science and Biotechnology, Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, Jeongeup 580-185 (Korea, Republic of)], E-mail: sjwlee@kaeri.re.kr

    2009-07-15

    {beta}-glucans are structural cell wall polymers of many microorganisms and cereals which possess immunomodulatory properties and have been used in the food, cosmetic and medical industry. In our previous study, {beta}-glucan was depolymerized by gamma irradiation and leads to improve the solubility and viscosity. This study was carried out to evaluate the functional properties, mainly immune-enhancing activities of low molecular weight {beta}-glucan fragmented by gamma irradiation. The results showed that RAW 264.7 macrophage cell stimulation activities of irradiated {beta}-glucan were higher than that of non-irradiated {beta}-glucan. In addition, the oral administration of gamma-irradiated {beta}-glucan significantly increased the proliferation and cytokine (IFN-{gamma} and IL-2) release of spleen and Peyer's patch cells compared with non-irradiated {beta}-glucan. In conclusion, gamma irradiation could be used as an effective method for the production of depolymerized {beta}-glucan improved functional property such as immunomodulatory activity.

  18. Release kinetics of prolyl hydroxylase inhibitors from collagen barrier membranes.

    Science.gov (United States)

    Hamid, Omar; Pensch, Manuela; Agis, Hermann

    2015-03-01

    Collagen barrier membranes are used in guided tissue regeneration to support healing. This strategy, however, relies on the healing capacity of the tissue. Pharmacological inhibitors of prolyl hydroxylases can support regeneration by enhancing angiogenesis and are therefore a promising tool for periodontology. Here we evaluate the release kinetics of the prolyl hydroxylase inhibitors dimethyloxalylglycine and L-mimosine from collagen barrier membranes. Dimethyloxalylglycine and L-mimosine were lyophilized onto the collagen barrier membranes. The morphology of the collagen barrier membranes was analysed using scanning electron microscopy. The release of prolyl hydroxylase inhibitors was assessed by colorimetric and spectroscopic methods. Their ability to induce a cellular response was assessed in bioassays with gingival and periodontal ligament fibroblasts based on vascular endothelial growth factor production, proliferation, and metabolic activity of the cells. We found that loading of collagen barrier membranes with prolyl hydroxylase inhibitors did not change the overall membrane morphology. Assessment of the release kinetics by direct measurements and based on vascular endothelial growth factor production showed that supernatants obtained from the collagen barrier membranes in the first 6 hours had a sufficient level of prolyl hydroxylase inhibitors to induce vascular endothelial growth factor production. A similar kinetic was found when cell proliferation was assessed. Changes in metabolic activity did not reach the level of significance in the MTT assay. In conclusion, collagen barrier membranes can release prolyl hydroxylase inhibitors thereby increasing the pro-angiogenic capacity of periodontal cells in vitro. These findings provide the basis for preclinical studies to evaluate the regenerative capacity of prolyl hydroxylase inhibitors in periodontology and oral surgery.

  19. Tumor-produced, active Interleukin-1 {beta} regulates gene expression in carcinoma-associated fibroblasts

    Energy Technology Data Exchange (ETDEWEB)

    Dudas, Jozsef, E-mail: Jozsef.Dudas@i-med.ac.at [Department of Otorhinolaryngology, Medical University Innsbruck, Anichstrasse 35, A-6020 Innsbruck (Austria); Fullar, Alexandra, E-mail: fullarsz@gmail.com [Department of Otorhinolaryngology, Medical University Innsbruck, Anichstrasse 35, A-6020 Innsbruck (Austria); 1st Institute of Pathology and Experimental Cancer Research, Semmelweis University, Ulloei ut 26, H-1085 Budapest (Hungary); Bitsche, Mario, E-mail: Mario.Bitsche@i-med.ac.at [Department of Otorhinolaryngology, Medical University Innsbruck, Anichstrasse 35, A-6020 Innsbruck (Austria); Schartinger, Volker, E-mail: Volker.Schartinger@i-med.ac.at [Department of Otorhinolaryngology, Medical University Innsbruck, Anichstrasse 35, A-6020 Innsbruck (Austria); Kovalszky, Ilona, E-mail: koval@korb1.sote.hu [1st Institute of Pathology and Experimental Cancer Research, Semmelweis University, Ulloei ut 26, H-1085 Budapest (Hungary); Sprinzl, Georg Mathias, E-mail: Georg.Sprinzl@i-med.ac.at [Department of Otorhinolaryngology, Medical University Innsbruck, Anichstrasse 35, A-6020 Innsbruck (Austria); Riechelmann, Herbert, E-mail: Herbert.Riechelmann@i-med.ac.at [Department of Otorhinolaryngology, Medical University Innsbruck, Anichstrasse 35, A-6020 Innsbruck (Austria)

    2011-09-10

    Recently we described a co-culture model of periodontal ligament (PDL) fibroblasts and SCC-25 lingual squamous carcinoma cells, which resulted in conversion of normal fibroblasts into carcinoma-associated fibroblasts (CAFs), and in epithelial-mesenchymal transition (EMT) of SCC-25 cells. We have found a constitutive high interleukin-1{beta} (IL1-{beta}) expression in SCC-25 cells in normal and in co-cultured conditions. In our hypothesis a constitutive IL1-{beta} expression in SCC-25 regulates gene expression in fibroblasts during co-culture. Co-cultures were performed between PDL fibroblasts and SCC-25 cells with and without dexamethasone (DEX) treatment; IL1-{beta} processing was investigated in SCC-25 cells, tumor cells and PDL fibroblasts were treated with IL1-{beta}. IL1-{beta} signaling was investigated by western blot and immunocytochemistry. IL1-{beta}-regulated genes were analyzed by real-time qPCR. SCC-25 cells produced 16 kD active IL1-{beta}, its receptor was upregulated in PDL fibroblasts during co-culture, which induced phosphorylation of interleukin-1 receptor-associated kinase-1 (IRAK-1), and nuclear translocalization of NF{kappa}B{alpha}. Several genes, including interferon regulatory factor 1 (IRF1) interleukin-6 (IL-6) and prostaglandin-endoperoxide synthase 2 (COX-2) were induced in CAFs during co-culture. The most enhanced induction was found for IL-6 and COX-2. Treatment of PDL fibroblasts with IL1-{beta} reproduced a time- and dose-dependent upregulation of IL1-receptor, IL-6 and COX-2. A further proof was achieved by DEX inhibition for IL1-{beta}-stimulated IL-6 and COX-2 gene expression. Constitutive expression of IL1-{beta} in the tumor cells leads to IL1-{beta}-stimulated gene expression changes in tumor-associated fibroblasts, which are involved in tumor progression. -- Graphical abstract: SCC-25 cells produce active, processed IL1-{beta}. PDL fibroblasts possess receptor for IL1-{beta}, and its expression is increased 4.56-times in the

  20. Enhanced Activity of Nanocrystalline Beta Zeolite for Acylation of Veratrole with Acetic Anhydride.

    Science.gov (United States)

    Aisha Mahmood Abdulkareem, Al-Turkustani; Selvin, Rosilda

    2016-04-01

    Friedel-Craft acylation of veratrole using homogeneous acid catalysts such as AlCl3, FeCl3, ZnCl2, and HF etc. produces acetoveratrone, (3',4'-dimethoxyacetophenone), which is the intermediate for synthesis of papavarine alkaloids. The problems associated with these homogeneous catalysts can be overcome by using heterogeneous solid catalysts. Since acetoveratrone is a larger molecule, large pore Beta zeolites with smaller particle sizes are beneficial for the liquid-phase acylation of veratrole, for easy diffusion of reactants and products. The present study aims in the acylation of veratrole with acetic anhydride using nanocrystalline Beta Zeolite catalyst. A systematic investigation of the effects of various reaction parameters was done. The catalysts were characterized for their structural features by using XRD, TEM and DLS analyses. The catalytic activity of nanocrystalline Beta zeolite was compared with commercial Beta zeolite for the acylation and was found that nanocrystalline Beta zeolite possessed superior activity.

  1. Ablation of PGC-1beta results in defective mitochondrial activity, thermogenesis, hepatic function, and cardiac performance.

    Directory of Open Access Journals (Sweden)

    Christopher J Lelliott

    2006-11-01

    Full Text Available The transcriptional coactivator peroxisome proliferator-activated receptor-gamma coactivator-1beta (PGC-1beta has been implicated in important metabolic processes. A mouse lacking PGC-1beta (PGC1betaKO was generated and phenotyped using physiological, molecular, and bioinformatic approaches. PGC1betaKO mice are generally viable and metabolically healthy. Using systems biology, we identified a general defect in the expression of genes involved in mitochondrial function and, specifically, the electron transport chain. This defect correlated with reduced mitochondrial volume fraction in soleus muscle and heart, but not brown adipose tissue (BAT. Under ambient temperature conditions, PGC-1beta ablation was partially compensated by up-regulation of PGC-1alpha in BAT and white adipose tissue (WAT that lead to increased thermogenesis, reduced body weight, and reduced fat mass. Despite their decreased fat mass, PGC1betaKO mice had hypertrophic adipocytes in WAT. The thermogenic role of PGC-1beta was identified in thermoneutral and cold-adapted conditions by inadequate responses to norepinephrine injection. Furthermore, PGC1betaKO hearts showed a blunted chronotropic response to dobutamine stimulation, and isolated soleus muscle fibres from PGC1betaKO mice have impaired mitochondrial function. Lack of PGC-1beta also impaired hepatic lipid metabolism in response to acute high fat dietary loads, resulting in hepatic steatosis and reduced lipoprotein-associated triglyceride and cholesterol content. Altogether, our data suggest that PGC-1beta plays a general role in controlling basal mitochondrial function and also participates in tissue-specific adaptive responses during metabolic stress.

  2. Xenon and halogenated alkanes track putative substrate binding cavities in the soluble methane monooxygenase hydroxylase.

    Science.gov (United States)

    Whittington, D A; Rosenzweig, A C; Frederick, C A; Lippard, S J

    2001-03-27

    To investigate the role of protein cavities in facilitating movement of the substrates, methane and dioxygen, in the soluble methane monooxygenase hydroxylase (MMOH), we determined the X-ray structures of MMOH from Methylococcus capsulatus (Bath) cocrystallized with dibromomethane or iodoethane, or by using crystals pressurized with xenon gas. The halogenated alkanes bind in two cavities within the alpha-subunit that extend from one surface of the protein to the buried dinuclear iron active site. Two additional binding sites were located in the beta-subunit. Pressurization of two crystal forms of MMOH with xenon resulted in the identification of six binding sites located exclusively in the alpha-subunit. These results indicate that hydrophobic species bind preferentially in preexisting cavities in MMOH and support the hypothesis that such cavities may play a functional role in sequestering and enhancing the availability of the physiological substrates for reaction at the active site.

  3. $\\beta$-Caseinophosphopeptide (f1-25) confers on $\\beta$-casein tryptic hydrolysate an antioxidant activity during iron/ascorbate-induced oxidation of liposomes

    OpenAIRE

    2004-01-01

    International audience; Protein ingredients such as hydrolysates of milk proteins may improve the nutritive value of functional foods. For instance, $\\beta$-casein tryptic hydrolysate could simultaneously increase iron absorption and prevent lipid oxidation in foods containing high contents of polyunsaturated fatty acids (PUFA). The aim of this study was to determine the antioxidant activity of $\\beta$-casein tryptic hydrolysate and of its $\\beta$-caseinophosphopeptide (f1-25) on Fe(III)/asco...

  4. Role of ROS-mediated TGF beta activation in laser photobiomodulation

    Science.gov (United States)

    Arany, Praveen R.; Chen, Aaron Chih-Hao; Hunt, Tristan; Mooney, David J.; Hamblin, Michael

    2009-02-01

    The ability of laser light to modulate specific biological processes has been well documented but the precise mechanism mediating these photobiological interactions remains an area of intense investigation. We recently published the results of our clinical trial with 30 patients in an oral tooth-extraction wound healing model using a 904nm GaAs laser (Oralaser 1010, Oralia, Konstnaz, Germany), assessing healing parameters using routine histopathology and immunostaining (Arany et al Wound Rep Regen 2007, 15, 866). We observed a better organized healing response in laser irradiated oral tissues that correlated with an increased expression of TGF-beta1 immediately post laser irradiation. Our data suggested the source of latent TGF-beta1 might be from the degranulating platelets in the serum, an abundant source of in vivo latent TGF-beta, in the freshly wounded tissues. Further, we also demonstrated the ability of the low power near-infrared laser irradiation to activate the latent TGF-beta complexes in vitro at varying fluences from 10sec (0.1 J/cm2) to 600secs (6 J/cm2). Using serum we observed two isoforms, namely TGF-beta1 and TGF-beta3, were capable of being activated by laser irradiation using an isoform-specific ELISA and a reporter based (p3TP) assay system. We are presently pursuing the precise photomolecular mechanisms focusing on potential chromophores, wavelength and fluence parameters affecting the Latent TGF-beta activation process in serum. As ROS mediated TGF-beta activation has been previously demonstrated and we are also exploring the role of Laser generated-ROS in this activation process. In summary, we present evidence of a potential molecular mechanism for laser photobiomodulation in its ability to activate latent TGF-beta complexes.

  5. A method for the determination of residual beta activity in drinking water samples

    Energy Technology Data Exchange (ETDEWEB)

    Idoeta, R. [Dpto. Ingenieria Nuclear y Mecanica de Fluidos, E. T. S. Ingenieria de Bilbao - Universidad del Pais Vasco (UPV/EHU), Alda. Urquijo s/n. 48013 Bilbao (Spain)], E-mail: raquel.idoeta@ehu.es; Herranz, M.; Abelairas, A.; Legarda, F. [Dpto. Ingenieria Nuclear y Mecanica de Fluidos, E. T. S. Ingenieria de Bilbao - Universidad del Pais Vasco (UPV/EHU), Alda. Urquijo s/n. 48013 Bilbao (Spain)

    2007-09-15

    The determination of residual beta activity in drinking water is usually needed in most monitoring programs. In this work a procedure for its determination is described and expressions for the calculations of detection limits and uncertainties are proposed.

  6. Comparison of Antioxidant and Antibacterial Activities of Free and Encapsulated Garlic Oil with Beta-cyclodextrin

    OpenAIRE

    2016-01-01

    Background and Objectives: Application of garlic oil in food industry can be improved by encapsulation. There is no study about the formation of inclusion complex of garlic oil by beta-cyclodextrin. The aim of the present study is comparison of the antioxidant and antibacterial activities of free and encapsulated garlic oil with beta-cyclodextrin.Materials and Methods: Antioxidant activity was determined by 1, 1- diphenyl-2- picryl-hydrazyl assay, and antibacterial properties by agar well dif...

  7. beta-Adrenergic agonist activity of a monoclonal anti-idiotypic antibody.

    Science.gov (United States)

    Guillet, J G; Kaveri, S V; Durieu, O; Delavier, C; Hoebeke, J; Strosberg, A D

    1985-03-01

    Hybridoma cells bearing monoclonal antibody against the beta-adrenergic ligand alprenolol were used as an immunogen to raise monoclonal anti-idiotypic antibodies. Of six anti-idiotypic antibodies, which inhibit ligand binding, three were able to recognize beta-adrenergic receptors. One of them, mAb2B4, an IgM that could be amplified into ascites, binds to the beta-adrenergic catecholamine receptors of intact epidermoid A431 cells and precipitates receptors solubilized from plasma membranes by digitonin. This antibody identifies the beta 2-adrenergic receptor of A431 cells as a single 55-kDa protein and stimulates adenylate cyclase activity. This stimulation is inhibited by the beta-adrenergic antagonist propranolol.

  8. Structural basis for substrate activation and regulation by cystathionine beta-synthase (CBS) domains in cystathionine [beta]-synthase

    Energy Technology Data Exchange (ETDEWEB)

    Koutmos, Markos; Kabil, Omer; Smith, Janet L.; Banerjee, Ruma (Michigan-Med)

    2011-08-17

    The catalytic potential for H{sub 2}S biogenesis and homocysteine clearance converge at the active site of cystathionine {beta}-synthase (CBS), a pyridoxal phosphate-dependent enzyme. CBS catalyzes {beta}-replacement reactions of either serine or cysteine by homocysteine to give cystathionine and water or H{sub 2}S, respectively. In this study, high-resolution structures of the full-length enzyme from Drosophila in which a carbanion (1.70 {angstrom}) and an aminoacrylate intermediate (1.55 {angstrom}) have been captured are reported. Electrostatic stabilization of the zwitterionic carbanion intermediate is afforded by the close positioning of an active site lysine residue that is initially used for Schiff base formation in the internal aldimine and later as a general base. Additional stabilizing interactions between active site residues and the catalytic intermediates are observed. Furthermore, the structure of the regulatory 'energy-sensing' CBS domains, named after this protein, suggests a mechanism for allosteric activation by S-adenosylmethionine.

  9. Co-expression pattern of dopamine beta-hydroxylase (DβH) and neuropeptide Y (NPY) within sympathetic innervation of ovary and umbilical cord of the European bison (Bison bonasus L.).

    Science.gov (United States)

    Skobowiat, Cezary; Panasiewicz, Grzegorz; Gizejewski, Zygmunt; Szafranska, Bozena

    2013-12-01

    Co-expression of dopamine β-hydroxylase (DβH) and neuropeptide Y (NPY) has never been examined in ovary (OV) and umbilical cord (UC) of the European bison (Eb), the endangered wild species. The OV and UC samples were harvested from seasonally eliminated Eb females (45-120 days post coitum). Frozen histological sections were examined by double fluorescent immunohistochemistry (dF-IHC), using the primary mouse anti-DβH monoclonals and rabbit anti-NPY polyclonals and then the immunocomplexes were visualized with FITC and CY3 fluorophores, respectively. Numerous DβH immunoreactive nerve fibers (DβH-IRs) and a little less frequent NPY-IRs were found in the bundle-like structures, innervating mainly perivascular regions of the OV. The NPY-IRs constantly co-expressed DβH, while some DβH-IRs did not express NPY. This specific pattern of innervation was observed both in the stromal and cortical regions of the OV. The simultaneous co-expression of DβH and NPY were also detected in the UC, in which specific single or bundle-like structures ran along the smooth muscles of blood vessels. The spatial-specific co-expression of DβH and NPY in OV and UC, may suggest that these markers are involved in the control of vascularization that regulates nourishing blood circulation required for proper pregnancy maintenance and efficient embryo/fetus development in the Eb.

  10. Proinflammatory cytokines activate the intrinsic apoptotic pathway in beta-cells

    DEFF Research Database (Denmark)

    Grunnet, Lars G; Aikin, Reid; Tonnesen, Morten F;

    2009-01-01

    of the intrinsic apoptotic pathway and the role of the two proapoptotic Bcl-2 proteins, Bad and Bax, were examined in beta-cells. RESEARCH DESIGN AND METHODS: Human and rat islets and INS-1 cells were exposed to a combination of proinflammatory cytokines (interleukin-1beta, interferon-gamma, and/or tumor necrosis......OBJECTIVE: Proinflammatory cytokines are cytotoxic to beta-cells and have been implicated in the pathogenesis of type 1 diabetes and islet graft failure. The importance of the intrinsic mitochondrial apoptotic pathway in cytokine-induced beta-cell death is unclear. Here, cytokine activation...... to investigate the role of Bad and Bax activation, respectively. RESULTS: We found that proinflammatory cytokines induced calcineurin-dependent dephosphorylation of Bad Ser136, mitochondrial stress, cytochrome c release, activation of caspase-9 and -3, and DNA fragmentation. Inhibition of Bad Ser136...

  11. Inhibition of AmpC beta-lactamase through a destabilizing interaction in the active site

    Energy Technology Data Exchange (ETDEWEB)

    Trehan, I.; Beadle, B.M.; Shoichet, B.K. (NWU)

    2010-03-08

    {beta}-Lactamases hydrolyze {beta}-lactam antibiotics, including penicillins and cephalosporins; these enzymes are the most widespread resistance mechanism to these drugs and pose a growing threat to public health. {beta}-Lactams that contain a bulky 6(7){alpha} substituent, such as imipenem and moxalactam, actually inhibit serine {beta}-lactamases and are widely used for this reason. Although mutant serine {beta}-lactamases have arisen that hydrolyze {beta}-lactamase resistant {beta}-lactams (e.g., ceftazidime) or avoid mechanism-based inhibitors (e.g., clavulanate), mutant serine {beta}-lactamases have not yet arisen in the clinic with imipenemase or moxalactamase activity. Structural and thermodynamic studies suggest that the 6(7){alpha} substituents of these inhibitors form destabilizing contacts within the covalent adduct with the conserved Asn152 in class C {beta}-lactamases (Asn132 in class A {beta}-lactamases). This unfavorable interaction may be crucial to inhibition. To test this destabilization hypothesis, we replaced Asn152 with Ala in the class C {beta}-lactamase AmpC from Escherichia coli and examined the mutant enzyme's thermodynamic stability in complex with imipenem and moxalactam. Consistent with the hypothesis, the Asn152 {yields} Ala substitution relieved 0.44 and 1.10 kcal/mol of strain introduced by imipenem and moxalactam, respectively, relative to the wild-type complexes. However, the kinetic efficiency of AmpC N152A was reduced by 6300-fold relative to that of the wild-type enzyme. To further investigate the inhibitor's interaction with the mutant enzyme, the X-ray crystal structure of moxalactam in complex with N152A was determined to a resolution of 1.83 {angstrom}. Moxalactam in the mutant complex is significantly displaced from its orientation in the wild-type complex; however, moxalactam does not adopt an orientation that would restore competence for hydrolysis. Although Asn152 forces {beta}-lactams with 6(7){alpha

  12. 21-Hydroxylase deficiency in Brazil

    Directory of Open Access Journals (Sweden)

    T.A.S.S. Bachega

    2000-10-01

    Full Text Available We determined the frequency of large rearrangements and point mutations in 130 Brazilian patients with 21-hydroxylase deficiency and correlated genotype with phenotype. The frequency of CYP21 deletions was lower (4.4% than in most of the previous series described, whereas the frequency of large gene conversions was similar to the frequency reported in the literature (6.6%. The most frequent point mutations were I2 splice (41.8% in salt wasting - SW, I172N (32.6% in simple virilizing - SV and V281L (40.2% in the late onset form - LO. The frequency of the nine most common point mutations was similar to that reported for other countries. The 93 fully genotyped patients were classified into 3 mutation groups based on the degree of enzymatic activity (A@ 2%, C>20%. In group A, 62% of cases presented the SW form; in group B, 96% the SV form, and in group C, 88% the LO form. We diagnosed 80% of the affected alleles after screening for large rearrangements and 15 point mutations. To diagnose these remaining alleles we sequenced the CYP21 gene of one patient with the SV form and identified a heterozygous G->A transition in codon 424. This mutation leads to a substitution of glycine by serine in a conserved region and was also found in a compound heterozygous state in 4 other patients. The mutation G424S presented a linkage disequilibrium with CYP21P and C4A gene deletions and HLA DR17, suggesting a probable founder effect. Search for the G424S mutation in other populations will reveal if it is restricted to the Brazilian patients or if it has a wider ethnic distribution.

  13. Neuronal injury induces the release of pro-interleukin-1beta from activated microglia in vitro.

    Science.gov (United States)

    Wang, Penglian; Rothwell, Nancy J; Pinteaux, Emmanuel; Brough, David

    2008-10-21

    Microglia activated after brain injury, are a major source of the pro-inflammatory cytokine interleukin-1 (IL-1), which is known to further exacerbate damage. However, the mechanisms that control IL-1 release in acute neuronal injury are unknown and the purpose of this study was to test the hypothesis that neuronal injury induces IL-1beta release from microglial cells. Here we report that lipopolysaccharide (LPS)-activated rat microglia co-cultured with healthy rat neurons express pro-IL-1beta, which in the absence of cell death accumulates in the cells. Treatment of co-cultures with the excitotoxin N-methyl-D-aspartate (NMDA) induced neuronal cell death leading to the appearance of pro-IL-1beta in the culture supernatant. This effect was reversed by the NMDA receptor antagonist MK-801, and was neuron-dependent, since NMDA had no effect on cell death or pro-IL-1beta release in mixed glial cell cultures. In addition, we show that pro-IL-1beta release from LPS-treated mixed glia or LPS-treated microglia is significantly reduced in the presence of conditioned medium from healthy co-cultures or neuronal cultures respectively. These results demonstrate that injured neurons promote the release of pro-IL-1beta from microglia, possibly by regulating microglial cell viability, and suggest an important alternative mechanism of IL-1beta release that occurs in response to neuronal injury.

  14. Localization of beta-D-glucosidase activity and glucovanillin in vanilla bean (Vanilla planifolia Andrews).

    Science.gov (United States)

    Odoux, E; Escoute, J; Verdeil, J-L; Brillouet, J-M

    2003-09-01

    The morphology, anatomy and histology of mature green vanilla beans were examined by light and transmission electron microscopy. Beans have a triangular cross-section with a central cavity containing seeds. Each angle is lined with tubular cells, or papillae, while the cavity sides consist of placental laminae. The epicarp and endocarp are formed by one or two layers of very small cells, while the mesocarp contains large, highly vacuolarized cells, the cytoplasm being restricted to a thin layer along the cell walls. The radial distributions of glucovanillin and beta-glucosidase activity, measured on p-nitrophenyl-beta-glucopyranoside and glucovanillin, are superimposable and show how beta-glucosidase activity increases from the epicarp towards the placental zone, whereas glucovanillin is exclusively located in the placentae and papillae. Subcellular localization of beta-glucosidase activity was achieved by incubating sections of vanilla beans in a buffer containing 5-bromo-4-chloro-3-indolyl-beta-d-glucopyranoside as a substrate. Activity was observed in the cytoplasm (and/or the periplasm) of mesocarp and endocarp cells, with a more diffuse pattern observed in the papillae. A possible mechanism for the hydrolysis of glucovanillin and release of the aromatic aglycon vanillin involves the decompartmentation of cytoplasmic (and/or periplasmic) beta-glucosidase and vacuolar glucovanillin.

  15. Glyceryl ether monooxygenase resembles aromatic amino acid hydroxylases in metal ion and tetrahydrobiopterin dependence.

    Science.gov (United States)

    Watschinger, Katrin; Keller, Markus A; Hermetter, Albin; Golderer, Georg; Werner-Felmayer, Gabriele; Werner, Ernst R

    2009-01-01

    Glyceryl ether monooxygenase is a tetrahydrobiopterin-dependent membrane-bound enzyme which catalyses the cleavage of lipid ethers into glycerol and the corresponding aldehyde. Despite many different characterisation and purification attempts, so far no gene and primary sequence have been assigned to this enzyme. The seven other tetrahydrobiopterin-dependent enzymes can be divided in the family of aromatic amino acid hydroxylases - comprising phenylalanine hydroxylase, tyrosine hydroxylase and the two tryptophan hydroxylases - and into the three nitric oxide synthases. We tested the influences of different metal ions and metal ion chelators on glyceryl ether monooxygenase, phenylalanine hydroxylase and nitric oxide synthase activity to elucidate the relationship of glyceryl ether monooxygenase to these two families. 1,10-Phenanthroline, an inhibitor of non-heme iron-dependent enzymes, was able to potently block glyceryl ether monooxygenase as well as phenylalanine hydroxylase, but had no effect on inducible nitric oxide synthase. Two tetrahydrobiopterin analogues, N(5)-methyltetrahydrobiopterin and 4-aminotetrahydrobiopterin, had a similar impact on glyceryl ether monooxygenase activity, as has already been shown for phenylalanine hydroxylase. These observations point to a close analogy of the role of tetrahydrobiopterin in glyceryl ether monooxygenase and in aromatic amino acid hydroxylases and suggest that glyceryl ether monooxygenase may require a non-heme iron for catalysis.

  16. Monitoring gross alpha and beta activity in liquids by using ZnS(Ag) scintillation detectors

    Energy Technology Data Exchange (ETDEWEB)

    Stevanato, L.; Cester, D.; Filippi, D.; Lunardon, M.; Mistura, G.; Moretto, S.; Viesti, G. [Department of Physics and Astronomy ' Galileo Galilei' , University of Padova, (Italy); Badocco, D.; Pastore, P.; Romanini, F. [Department of Chemical Sciences, University of Padova, (Italy)

    2015-07-01

    In this work the possibility of monitoring gross alpha and beta activity in liquids using EJ-444 was investigated. Specific tests were carried out to determine the change of the detector properties in water tests. Possible protecting coating is also proposed and tested. Alpha/beta real-time monitoring in liquids is a goal of the EU project TAWARA{sub R}TM. (authors)

  17. Cytochrome P3-450 cDNA encodes aflatoxin B1-4-hydroxylase.

    Science.gov (United States)

    Faletto, M B; Koser, P L; Battula, N; Townsend, G K; Maccubbin, A E; Gelboin, H V; Gurtoo, H L

    1988-09-01

    Aflatoxin B1 (AFB1), a potent hepatocarcinogen and ubiquitous dietary contaminant in some countries, is detoxified to aflatoxin M1 (AFM1) via cytochrome P-450-mediated AFB1-4-hydroxylase. Genetic studies in mice have demonstrated that the expression of AFB1-4-hydroxylase is regulated by the aryl hydrocarbon locus and suggested that different cytochrome P-450 isozymes catalyze AFB1-4-hydroxylase and aryl hydrocarbon hydroxylase activities. We have now examined lysates from mammalian cells infected with recombinant vaccinia viruses containing expressible cytochrome P1-450 or P3-450 cDNAs for their ability to metabolize AFB1 to AFM1. Our results show that cytochrome P3-450 cDNA specifies AFB1-4-hydroxylase. This is the first direct assignment of a specific cytochrome P-450 to an AFB1 detoxification pathway. This finding may have relevance to the dietary modulation of AFB1 hepatocarcinogenesis.

  18. Identification and characterization of phenol hydroxylase from phenol-degrading Candida tropicalis strain JH8.

    Science.gov (United States)

    Long, Yan; Yang, Sheng; Xie, Zhixiong; Cheng, Li

    2014-09-01

    The gene phhY encoding phenol hydroxylase from Candida tropicalis JH8 was cloned, sequenced, and expressed in Escherichia coli. The gene phhY contained an open reading frame of 2130 bp encoding a polypeptide of 709 amino acid residues. From its sequence analysis, it is a member of a family of flavin-containing aromatic hydroxylases and shares 41% amino acid identity with phenol hydroxylase from Trichosporon cutaneum. The recombinant phenol hydroxylase exists as a homotetramer structure with a native molecular mass of 320 kDa. Recombinant phenol hydroxylase was insensitive to pH treatment; its optimum pH was at 7.6. The optimum temperature for the enzyme was 30 °C, and its activity was rapidly lost at temperatures above 60 °C. Under the optimal conditions with phenol as substrate, the K(m) and V(max) of recombinant phenol hydroxylase were 0.21 mmol·L(-1) and 0.077 μmol·L(-1)·min(-1), respectively. This is the first paper presenting the cloning and expression in E. coli of the phenol hydroxylase gene from C. tropicalis and the characterization of the recombinant phenol hydroxylase.

  19. Decreased beta-band activity is correlated with disambiguation of hidden figures.

    Science.gov (United States)

    Minami, Tetsuto; Noritake, Yosuke; Nakauchi, Shigeki

    2014-04-01

    Insight is commonly described as sudden comprehension, sometimes called an "Aha! moment." In everyday life, we apply the process of insight to problems that are difficult to solve at first glance or that we perceive as ambiguous; however the brain dynamics underlying the disambiguation process remains elusive. Beta-band oscillatory brain activity has been hypothesized to reflect the transition of cognitive states. To elucidate the neural mechanism of insight, we recorded electroencephalograms while subjects were presented with hidden figures followed by unambiguous, gray images. We identified oscillatory activity to detect temporal changes, and compared brain activity that occurred during a perceptual transition with activity that occurred when no perceptual transition occurred. Statistical comparison confirmed stronger beta-power decrease during perceptual transition. Source analysis indicated that the beta-power decrease was around the parietal-posterior regions, mainly in the precuneus. We propose that beta-band desynchronization in the parietal-posterior regions reflects the disambiguation process, and our findings provide additional support for the theory that beta-band activity is related to the transition of cognitive state.

  20. Interleukin-1beta induced vascular permeability is dependent on induction of endothelial tissue factor (TF) activity.

    Science.gov (United States)

    Puhlmann, Markus; Weinreich, David M; Farma, Jeffrey M; Carroll, Nancy M; Turner, Ewa M; Alexander, H Richard

    2005-09-30

    IL-1beta is a pleotropic cytokine that may mediate increased procoagulant activity and permeability in endothelial tissue during inflammatory conditions. The procoagulant effects of IL-1beta are mediated through induction of tissue factor (TF) but its alterations on vascular permeability are not well characterized. We found that IL-1beta induced a rapid and dose-dependent increase in TF activity in human umbilical vein endothelial cells (ECs) under routine culture conditions. However, IL-1beta caused a rapid and marked increase in permeability across confluent EC monolayers using a two-compartment in vitro model only in the presence of factor VIII-deficient plasma that was completely abrogated by neutralizing anti-TF antibody pre-treatment. In vitro permeability was associated with loss of EC surface expression of VE-cadherin and contraction of F-actin cytoskeletal elements that resulted in EC intercellular gap formation. These data demonstrate that IL-1beta induces marked changes in permeability across activated endothelium via a TF dependent mechanism and suggest that modulation of TF activity may represent a strategy to treat various acute and chronic inflammatory conditions mediated by this cytokine.

  1. TLR2 is a primary receptor for Alzheimer's amyloid beta peptide to trigger neuroinflammatory activation.

    NARCIS (Netherlands)

    Liu, S.; Liu, Y.; Hao, W.; Wolf, L.; Kiliaan, A.J.; Penke, B.; Rube, C.E.; Walter, J.; Heneka, M.T.; Hartmann, T.; Menger, M.D.; Fassbender, K.

    2012-01-01

    Microglia activated by extracellularly deposited amyloid beta peptide (Abeta) act as a two-edged sword in Alzheimer's disease pathogenesis: on the one hand, they damage neurons by releasing neurotoxic proinflammatory mediators (M1 activation); on the other hand, they protect neurons by triggering an

  2. Effect of environmental estrogens on IL-1beta promoter activity in a macrophage cell line.

    Science.gov (United States)

    Ruh, M F; Bi, Y; Cox, L; Berk, D; Howlett, A C; Bellone, C J

    1998-10-01

    Environmental estrogens or estrogen disrupters have recently received a great deal of attention because of their potential health impact on reproductive tissues. Few, if any, studies have been made on the impact of these compounds on the immune system. We sought to determine the activities of various environmental estrogens on the modulation of the interleukin-1beta (IL-1beta) gene in a model monocytic cell line, hER + IL-1beta-CAT+. This cell line stably transfected with the human estrogen receptor, and an IL-1beta promoter construct fused to the CAT reporter gene allows us to monitor the effect of estrogenic compounds on IL-1beta promoter activity. 17beta-estradiol (E2) markedly enhanced lipopolysaccharide- (LPS) induced IL-1beta promoter-driven CAT activity in a dose-dependent manner. The mycotoxins alpha-zearalenol and zearalenone both exhibited full agonist activity, but at lower potencies, with EC50 values of 1.8 and 54 nM, respectively, compared with E2 at 0.5 nM. In addition, genistein was a very low-potency agonist, having an EC50 of 1.5 microM. Similar to the E2 response, the slope factors for alpha-zearalenol, zearalenone, and genistein were close to 3.0, suggesting positive cooperativity in the estrogenic response. The activity of the mycotoxins appeared to be mediated through the estrogen receptor, since both the antiestrogens H1285 and ICI 182,780 effectively inhibited their agonist activity in a dose-dependent manner. Representative environmental estrogenic compounds both from plant and industrial sources were also tested. Unlike the mycoestrogens, none of the compounds, with the exception of genistein, synergized with LPS to enhance IL-1beta promoter activity. When tested for antiestrogenic activity, the industrial compound 4-octylphenol was able to antagonize the response to E2; however, the response was three orders of magnitude less potent than H 1285. Naringenin, a plant flavonoid, showed little or no ability to antagonize the response to E2

  3. [Synthesis of novel beta-aminoalcohols containing nabumetone moiety with potential antidiabetic activity].

    Science.gov (United States)

    Zhang, Kun; Yan, Ju-fang; Tang, Xue-mei; Liu, Hong-ping; Fan, Li; Zhou, Guang-ming; Yang, Da-cheng

    2011-04-01

    Twenty five new beta-aminoalcohols containing nabumetone moiety were prepared via the reduction of potassium borohydride with a convenient and efficient procedure, starting from beta-aminoketones that have been synthesized by our group. Their chemical structures were determined by IR, MS, 1H NMR, 13C NMR, HR-MS and antidiabetic activities were screened in vitro. Preliminary results revealed that the antidiabetic activity of most beta-aminoalcohols were better than that of the corresponding beta-aminoketones. Although most compounds showed weak antidiabetic activity, the alpha-glucosidase inhibitory activity of compounds 5hd(1) and 5id(2) reached 74.37% and 90.15%, respectively, which were superior to the positive control. The relative peroxisome proliferator-activated receptor response element (PPRE) activity of five compounds were more than 60%, among them compound 5ca possessed the highest activity (112.59%). As lead molecules of antidiabetic agents, compounds 5hd(1), 5id(2) and 5ca deserve further study.

  4. Determination of total alpha and beta activities on vegetable samples by LSC; Determinacao de atividades alfa total e beta total em amostras vegetais por LSC

    Energy Technology Data Exchange (ETDEWEB)

    Nogueira, Regina Apolinaria; Santos, Eliane Eugenia dos; Bakker, Alexandre Pereira [Centro Regional de Ciencias Nucleares do Centro-Oeste (CRCN-CO/CNEN-GO), Abadia de Goias, GO (Brazil); Vavassori, Giullia [Centro Regional de Ciencias Nucleares do Centro-Oeste (CRCN-CO/CNEN-GO), Abadia de Goias, GO (Brazil); Pontificia Universidade Catolica de Goias (PUC-GO), Goiania, GO (Brazil). Dept. de Engenharia, Engenharia Ambiental; Mingote, Raquel Maia [Centro Regional de Ciencias Nucleares do Centro-Oeste (CRCN-CO/CNEN-GO), Abadia de Goias, GO (Brazil); Universidade Federal de Minas Gerais (DEN/UFMG), Belo Horizonte, MG (Brazil)

    2011-07-01

    Gross alpha and beta analyses are screening techniques used for environmental radioactivity monitoring. The present study proposes to determine the gross alpha and beta activities in vegetable samples by using LSC - liquid scintillation spectrometry. The procedure was applied to vegetable foods. After ashing vegetable samples in a muffle furnace, 100 mg of ash were added to gel mixture of scintillation cocktails, Water - Instagel - Ultima Gold AB (6:10:4) ml, in polyethylene vial. Am-241 standard solution and a KCl (K-40) solution were used to determine the counting configuration, alpha/beta efficiencies and spillover

  5. Age-related differences in EEG beta activity during an assessment of ankle proprioception.

    Science.gov (United States)

    Toledo, Diana R; Barela, José A; Manzano, Gilberto M; Kohn, André F

    2016-05-27

    The aim of this work was to compare cortical beta oscillatory activity between young (YA) and older (OA) adults during the assessment of ankle proprioception. We analyzed the response time (RT) to kinesthetic perception and beta event-related desynchronization/synchronization (ERD/ERS) in response to passive ankle movement applied at a slow speed, 0.5°/s. The relationship between ERD/ERS and RT was investigated by classifying the signals into fast-, medium-, and slow-RT. The results showed a temporal relationship between beta oscillation changes and RT for both groups, i.e., earlier ERD and ERS were obtained for trials with faster response time. ERD was larger and delayed in OA compared to the YA, and beta ERS was present only for OA. These findings suggest that a less efficient proprioceptive signaling reaching the brain of OA requires a higher level of brain processing and hence the differences in ERD potentials between YA and OA. Furthermore, the occurrence of ERS in OA might represent a compensatory strategy of active cortical resetting for adequate sensorimotor behavior due to the age-related reduced peripheral input and neuromuscular impairments. Altered balance between excitatory and inhibitory intracortical activity in older adults presumably explains the changes in beta oscillations.

  6. [Determination of beta-mannanase activity by viscosimetric and spectrophotometric methods].

    Science.gov (United States)

    Firantas, S G; Venozhinskene, Iu I; Pauliukonis, A B

    1982-01-01

    The activity of beta-mannanase from Bacillus subtilis was measured viscosimetrically and spectrophotometrically. As substrate galactomannane of Ceratonia siliqua was used. Relationships between the beta-mannanase activity and the substrate concentration as well as the enzyme content were investigated. The kinetic parameters of the enzymes obeying the Michaelis-Menten equation were calculated. It was found viscosimetrically that Vmax of the commercial enzyme preparation was 1.4 mucat/g (at pH 5.8 and 40 degrees) and Km was 0.6 mM. The viscosimetric method shows high sensitivity, whereas the spectrophotometric technique suits mass-scale analyses.

  7. Andrographolide inhibits NF-kappaBeta activation and attenuates neointimal hyperplasia in arterial restenosis.

    Science.gov (United States)

    Wang, Yu-Jiu; Wang, Jin-Tao; Fan, Quan-Xin; Geng, Jian-Guo

    2007-11-01

    The NF-kappaBeta transcription factors modulate the expression of tissue factor (TF), E-selectin (CD62E) and vascular cell adhesion molecule-1 (VCAM-1), which are essential for thrombosis and inflammation. We have previously shown that andrographolide (Andro) covalently modifies the reduced cysteine(62) of p50 - a major subunit of NF-kappaBeta transcription factors, thus blocking the binding of NF-kappaBeta transcription factors to the promoters of their target genes, preventing NF-kappaBeta activation and inhibiting inflammation in vitro and in vivo. Here we report that Andro, but not its inactive structural analog 4H-Andro, significantly suppressed the proliferation of arterial neointima ( approximately 60% reduction) in a murine model of arterial restenosis. Consistently, p50(-/-) mice manifested attenuated neointimal hyperplasia upon arterial ligation. Notably, the same dosage of Andro did not further reduce neointimal formation in p50(-/-) mice, which implicates the specificity of Andro on p50 for treating experimental arterial restenosis. The upregulation of NF-kappaBeta target genes, including TF, E-selectin and VCAM-1, and the increased deposition of leukocytes (mainly CD68+ macrophages) were clearly detected within the injured arterial walls, all of which were significantly abolished by treatment with Andro or genetic deletion of p50. The expression of TF, E-selectin and VCAM-1 was also markedly upregulated in the patient sample of thrombotic vasculitis, indicating the clinical relevance of NF-kappaBeta activation in the pathogeneses of occlusive arterial diseases. Our data thus indicate that, by the downregulation of the NF-kappaBeta target genes that are critical in thrombosis and inflammation, specific inhibitors of p50, such as Andro, may be therapeutically valuable for preventing and treating thrombotic arterial diseases, including neointimal hyperplasia in arterial restenosis.

  8. Rapid determination of gross alpha/beta activity in milk using liquid scintilation counter technique

    Directory of Open Access Journals (Sweden)

    Sas Daniel

    2016-01-01

    Full Text Available Rapid determination of gross alpha and beta emitters in milk by liquid scintillation counter is discussed. This method is based on direct addition of different types of milk into scintillation cocktail and therefore it is very promising for fast determination of alpha/beta activity due to direct alpha and beta separation, measurement in close 4p geometry and without sample treatment. The selected group of radionuclides was chosen with the respect to military significance, radio-toxicity, and possibility of potential misuse. As model radionuclides 241Am, 239Pu, and 90Sr were selected. The Liquid Scintilation Counter Hidex 300 SL equipped with triple-double-coincidence-ratio technique was used for sample measurement. The aim of the work was focused on comparison of different cocktails produced by Hidex and Perkin Elmer, choosing the best cocktail based on our measurement results and adjustment of its appropriate volume. Furthermore, the optimization of ratio between the volume of scintillation cocktail and the volume of urine was investigated with the respect to the model radionuclides. According to the obtained results, the efficiency for alpha emitters was greater than 85% and for beta, greater than 95%. The obtained results allowed this method to be used for rapid determination of gross alpha/beta activity in cases where time is an essence, such as first responders or mass-scale samples, where ordinary means suffer from lack of capacity or simply collapse under the onslaught.

  9. Redox-active cellulose Langmuir-Blodgett films containing beta-carotene as a molecular wire.

    Science.gov (United States)

    Sakakibara, Keita; Kamitakahara, Hiroshi; Takano, Toshiyuki; Nakatsubo, Fumiaki

    2007-05-01

    Redox-active Langmuir-Blodgett (LB) films containing dihydrophytyl ferrocenoate (DFc) and beta-carotene (betaC) were fabricated by use of 6-O-dihydrophytylcellulose (DHPC) as a matrix. A mixture of DFc-DHPC formed a stable monolayer. Atomic force microscopy images revealed that the DFc molecules were dispersed uniformly throughout the surface in the ratio DFc:DHPC = 2:8 at 30 mN m-1. The DFc-DHPC monolayer was transferred successfully onto a substrate, yielding Y-type LB films. Cyclic voltammograms for the DFc-DHPC LB films on an indium tin oxide (ITO) electrode exhibited a well-defined surface wave. The voltammograms of the DFc-DHPC LB films exhibited 60-40% redox-active ferrocene moieties, whereas those of the DFc-DHPC-betaC LB films exhibited 90-70%. X-ray diffraction patterns indicated that the distance between layers was independent of betaC molecules incorporated into the LB films. Consequently, these results suggested that betaC can function as a molecular wire.

  10. Amylase,. beta. -glucanase and protease activities from a mutant of Bacillus subtilis

    Energy Technology Data Exchange (ETDEWEB)

    Yin, X.S.; Li, Y.X. (Wuxi Inst. of Light Industry, JS (China). Dept. of Fermentation Technology); Stark, J.R. (International Centre for Brewing and Distilling, Edinburgh (UK))

    1991-10-01

    Enzymes in the shake culture of a mutant of Bacillus subtilis developed mainly during the stationary phase of growth. Extracellular {alpha}-amylase and protease activities increased and then declined to relatively low levels after 48 h of incubation while the {beta}-glucanase activity remained high. The production of extracellular proteolytic activity commenced only when the low molecular weight nitrogen source in the medium was completely consumed. Enzymes were fractionated by ion-exchange chromatography and the molecular weights of {beta}-glucanase, {alpha}-amylase, protease I and protease II were estimated by gel filtration to be 1.3x10{sup 4}, 3.2x10{sup 4}, 6.3x10{sup 3} and 2.0x10{sup 4}, respectively. The {beta}-glucanase and {alpha}-amylase showed maximum activities at around pH 7, but the two proteases had different pH optima (pH 6-7 and 8.5, respectivelty). The presence of proteolytic activity in the enzyme preparation had a significant effect on the stability of the {beta}-glucanase and the {alpha}-amylase at 65deg C. (orig.).

  11. Detection of alpha- and beta-hemolytic-like activity from Campylobacter jejuni.

    OpenAIRE

    Misawa, N; Hirayama, K.; Itoh, K.; Takahashi, E.

    1995-01-01

    Alpha-hemolytic-like activity from Campylobacter jejuni was clearly apparent when the medium pH ranged from 6.0 to 6.5, but the hemolytic zones disappeared when the pH of the medium increased. Beta-hemolytic-like activity just beneath the bacterial growth appeared after prolonged incubation. The hemolytic activity was not influenced by the species of blood.

  12. beta-carotene does not change markers of enzymatic and nonenzymatic antioxidant activity in human blood

    DEFF Research Database (Denmark)

    Castenmiller, J.J.M.; Lauridsen, Søren T.; Dragsted, Lars O.;

    1999-01-01

    and erythrocyte enzyme activities were assessed, and differences among experimental groups were tested. Consumption of spinach resulted in greater (P catalase activity and serum alpha-tocopherol concentration compared...... to an increased carotenoid (lutein and zeaxanthin) intake, but beta-carotene is unlikely to be a causative factor. Lower erythrocyte catalase activity after intervention with spinach products may be related to other constituents in spinach such as flavonoids....

  13. Crystal structure of the ternary complex of the catalytic domain of human phenylalanine hydroxylase with tetrahydrobiopterin and 3-(2-thienyl)-L-alanine, and its implications for the mechanism of catalysis and substrate activation.

    Science.gov (United States)

    Andersen, Ole Andreas; Flatmark, Torgeir; Hough, Edward

    2002-07-26

    Phenylalanine hydroxylase catalyzes the stereospecific hydroxylation of L-phenylalanine, the committed step in the degradation of this amino acid. We have solved the crystal structure of the ternary complex (hPheOH-Fe(II).BH(4).THA) of the catalytically active Fe(II) form of a truncated form (DeltaN1-102/DeltaC428-452) of human phenylalanine hydroxylase (hPheOH), using the catalytically active reduced cofactor 6(R)-L-erythro-5,6,7,8-tetrahydrobiopterin (BH(4)) and 3-(2-thienyl)-L-alanine (THA) as a substrate analogue. The analogue is bound in the second coordination sphere of the catalytic iron atom with the thiophene ring stacking against the imidazole group of His285 (average interplanar distance 3.8A) and with a network of hydrogen bonds and hydrophobic contacts. Binding of the analogue to the binary complex hPheOH-Fe(II).BH(4) triggers structural changes throughout the entire molecule, which adopts a slightly more compact structure. The largest change occurs in the loop region comprising residues 131-155, where the maximum r.m.s. displacement (9.6A) is at Tyr138. This loop is refolded, bringing the hydroxyl oxygen atom of Tyr138 18.5A closer to the iron atom and into the active site. The iron geometry is highly distorted square pyramidal, and Glu330 adopts a conformation different from that observed in the hPheOH-Fe(II).BH(4) structure, with bidentate iron coordination. BH(4) binds in the second coordination sphere of the catalytic iron atom, and is displaced 2.6A in the direction of Glu286 and the iron atom, relative to the hPheOH-Fe(II).BH(4) structure, thus changing its hydrogen bonding network. The active-site structure of the ternary complex gives new insight into the substrate specificity of the enzyme, notably the low affinity for L-tyrosine. Furthermore, the structure has implications both for the catalytic mechanism and the molecular basis for the activation of the full-length tetrameric enzyme by its substrate. The large conformational change, moving

  14. Receptor density is key to the alpha2/beta interferon differential activities.

    Science.gov (United States)

    Moraga, Ignacio; Harari, Daniel; Schreiber, Gideon; Uzé, Gilles; Pellegrini, Sandra

    2009-09-01

    Multiple type I interferons (IFN-alpha/beta) elicit Jak/Stat activation, rapid gene induction, and pleiotropic effects, such as differentiation, antiviral protection, and blocks in proliferation, which are dependent on the IFN subtype and the cellular context. To date, ligand- and receptor-specific molecular determinants underlying IFN-alpha/beta differential activities or potencies have been well characterized. To analyze cellular determinants that impact subtype-specific potency, human fibrosarcoma U5A-derived clones, exhibiting a gradient of IFN sensitivity by virtue of increasing receptor levels, were monitored for Jak/Stat signaling, gene induction, cell cycle lengthening, and apoptosis. In cells with scarce receptors, IFN-beta was more potent than IFN-alpha2 in antiproliferative activity, while the two subtypes were equipotent in all other readouts. Conversely, in cells with abundant receptors, IFN-alpha2 matched or even surpassed IFN-beta in all readouts tested. Our results suggest that the differential activities of the IFN subtypes are dictated not only by the intrinsic ligand/receptor binding kinetics but also by the density of cell surface receptor components.

  15. The gamma activities from the beta decay of /sup 27-34/Na and their descendants

    CERN Document Server

    Guillemaud, D; Détraz, C; Epherre-Rey-Campagnolle, Marcelle; Klapisch, Robert; Langevin, M; Naulin, F; Thibault, C; Touchard, F

    1981-01-01

    The gamma activities from the beta decay of Na isotopes up to /sup 34 /Na, which are formed in high energy fragmentation, are observed. The gamma intensities and delayed-neutron branching ratios P/sub n/ are measured. Preliminary decay schemes are obtained. (3 refs).

  16. Beta-ionone activates and bleaches visual pigment in salamander photoreceptors.

    Science.gov (United States)

    Isayama, Tomoki; McCabe England, S L; Crouch, R K; Zimmerman, A L; Makino, C L

    2009-01-01

    Vision begins with photoisomerization of 11-cis retinal to the all-trans conformation within the chromophore-binding pocket of opsin, leading to activation of a biochemical cascade. Release of all-trans retinal from the binding pocket curtails but does not fully quench the ability of opsin to activate transducin. All-trans retinal and some other analogs, such as beta-ionone, enhance opsin's activity, presumably on binding the empty chromophore-binding pocket. By recording from isolated salamander photoreceptors and from patches of rod outer segment membrane, we now show that high concentrations of beta-ionone suppressed circulating current in dark-adapted green-sensitive rods by inhibiting the cyclic nucleotide-gated channels. There were also decreases in circulating current and flash sensitivity, and accelerated flash response kinetics in dark-adapted blue-sensitive (BS) rods and cones, and in ultraviolet-sensitive cones, at concentrations too low to inhibit the channels. These effects persisted in BS rods even after incubation with 9-cis retinal to ensure complete regeneration of their visual pigment. After long exposures to high concentrations of beta-ionone, recovery was incomplete unless 9-cis retinal was given, indicating that visual pigment had been bleached. Therefore, we propose that beta-ionone activates and bleaches some types of visual pigments, mimicking the effects of light.

  17. Discoidin domain receptor 1 is activated independently of beta(1) integrin

    DEFF Research Database (Denmark)

    Vogel, W; Brakebusch, C; Fässler, R

    2000-01-01

    Various types of collagen have been identified as potential ligands for the two mammalian discoidin domain receptor (DDR) tyrosine kinases, DDR1 and DDR2. It is presently unclear whether collagen-induced DDR receptor activation, which occurs with very slow kinetics, involves additional proteins...... with kinase activity or membrane-anchored proteins serving as coreceptors. In particular, the role of the collagen-binding integrins alpha(1)beta(1) or alpha(2)beta(1) in the DDR activation process is undefined. Here, we provide three lines of evidence suggesting that DDR1 signaling is distinct from integrin...... activation. First we demonstrate that the enzymatic activity of DDR1 is essential for receptor tyrosine phosphorylation. Collagen-induced DDR receptor autophosphorylation can be blocked either by a dominant negative mutant or by a preparation of recombinant extracellular domain. Second, we show DDR1 signals...

  18. High isoproterenol doses are required to activate beta3-adrenoceptor-mediated functions in dogs.

    Science.gov (United States)

    Pelat, Michel; Verwaerde, Patrick; Galitzky, Jean; Lafontan, Max; Berlan, Michel; Senard, Jean-Michel; Montastruc, Jean-Louis

    2003-01-01

    The "in vivo" conditions for beta3-adrenoceptors (beta-AR) activation by isoproterenol were investigated in dog. Experiments were carried out in anesthetized dogs using isoproterenol as a nonselective beta-AR agonist. Intravenous infusion of isoproterenol (0.4 nmol/kg/min) induced arterial hypotension and tachycardia with a slight decrease in cutaneous blood flow. At this dose, isoproterenol increased glucose, glycerol, and nonesterified fatty acid plasma levels. The changes in cardiovascular and endocrine-metabolic parameters, induced by the low dose of isoproterenol, were suppressed by pretreatment with nadolol (1 mg/kg, i.v.). After nadolol administration, however, a 10-fold higher dose (4 nmol/kg/min) of isoproterenol was able to induce a decrease in arterial blood pressure with a slight tachycardia and an increase in cutaneous blood flow. This high dose of isoproterenol increased nonesterified fatty acid and glycerol plasma levels but failed to change glucose plasma levels. All these effects were abolished by a pretreatment with nadolol (1 mg/kg, i.v.) plus SR59230A [a selective beta3-adrenoceptor antagonist; (3-(2-ethylphenoxy)-1(1S)-1,2,3,4-tetrahydronaphth-1-ylaminol-(2S)2-propanol oxalate); 1 mg/kg, i.v.]. Moreover, as observed with the high dose of isoproterenol under nadolol pretreatment, an infusion of SR58611A [a selective beta3-adrenoceptor agonist; ((N2S)-7-carbethoxymethoxy-1,2,3,4-tetrahydronaphth-2-yl-(2R)-2-hydroxy-2-chlorophenyl) ethanamine hydrochloride] induces a decrease in mean arterial blood pressure associated with an increase in heart rate, cutaneous blood flow, and nonesterified fatty acid and glycerol plasma levels. These results demonstrate that the in vivo activation of beta3-adrenoceptors requires higher doses of catecholamine than those necessary for beta1- and/or beta2-adrenoceptor stimulation. These results also argue for the lack of a beta3-AR involvement in the control of heart rate and glycogenolysis in dogs.

  19. A note on starch hydrolysis and beta-glucuronidase activity among flavobacteria.

    Science.gov (United States)

    Petzel, J P; Hartman, P A

    1986-11-01

    Most flavobacteria tested with the fluorogenic substrate 4-methylumbelliferyl-beta-D-glucuronide possessed beta-glucuronidase (GUD), but when some of the same strains were tested with the API ZYM gallery, all were negative for GUD. Conflicting reports also appear in the literature about starch hydrolysis among flavobacteria. We observed that the results obtained can depend on the medium used and the length of incubation. Our results indicate that GUD activity and starch hydrolysis are more widely distributed in the genus Flavobacterium than previously reported.

  20. Purification and Characterization of Tryptophan Hydroxylase

    DEFF Research Database (Denmark)

    Haahr, Lærke Tvedebrink

    This thesis deals with the purification and characterization of the iron-containing enzyme tryptophan hydroxylase (TPH). TPH exists in two isoforms, called TPH1 and TPH2. Each isoform consists of threestructural distinct domains: the regulatory, the catalytic and the tetramerization domain. TPH...... of this project was to developpurification methods for full-length TPH1 and TPH2 as well as to characterize purified TPH variants. A successful purification method for full-length human TPH1 (hTPH1) was developed, which resulted in pure, active and stable protein. The method includes affinity-purification using....... The crystallization procedure for the catalytic domain of gallus gallus TPH1 (cgTPH1) was optimized to faster crystal growth by addition of tryptophan and incubation at room temperature. Crystals without imidazole in the crystallization conditions could be obtained. The solved structures were however of poor quality...

  1. Sumoylation regulates the transcriptional activity of MafA in pancreatic beta cells.

    Science.gov (United States)

    Shao, Chunli; Cobb, Melanie H

    2009-01-30

    MafA is a transcriptional regulator expressed primarily in pancreatic beta cells. It binds to the RIPE3b/C1-binding site within the ins gene promoter, which plays a critical role in regulating ins gene expression in response to glucose. Here, we show that MafA is post-translationally modified by the small ubiquitin-related modifiers SUMO-1 and -2. Mutation of a single site in MafA, Lys(32), blocks its sumoylation in beta cells. Incubation of beta cells in low glucose (2 mm) or exposure to hydrogen peroxide increases sumoylation of endogenous MafA. Forced sumoylation of MafA results in reduced transcriptional activity toward the ins gene promoter and increased suppression of the CHOP-10 gene promoter. Sumoylation of MafA has no apparent effect on either its nuclear localization in beta cells or its ubiquitin-dependent degradation. This study suggests that modification of MafA by SUMO modulates gene transcription and thereby beta cell function.

  2. Transforming growth factor-beta modulates plasminogen activator activity and plasminogen activator inhibitor type-1 expression in human keratinocytes in vitro.

    Science.gov (United States)

    Wikner, N E; Elder, J T; Persichitte, K A; Mink, P; Clark, R A

    1990-11-01

    Transforming growth factor beta (TGF-beta) is a multifunctional mediator with effects on cellular growth, differentiation, and extracellular matrix (ECM) metabolism. Because TGF-beta stimulates fibronectin expression in cultured human keratinocytes, we wished to determine whether it might also affect ECM degradation through the plasminogen activator (PA)-plasminogen activator inhibitor (PAI) system. Immunofluorescence of human keratinocytes using a monospecific antiserum to type 1 PAI (PAI-1) showed enhanced cellular and ECM staining when they were cultured in the presence of TGF-beta. The antiserum also identified an Mr 50,000 protein in conditioned media that was markedly enhanced by TGF-beta. A corresponding stimulation of PAI-1 mRNA was demonstrated by quantitative RNA blot analysis. Total plasminogen activating activity of conditioned medium was markedly decreased by TGF-beta. Zymography showed this to be at least partially due to decreased secreted urokinase activity. TGF-beta may play an important role in stabilizing the provisional matrix synthesized by keratinocytes in healing wounds.

  3. Hormone-sensitive lipase, the rate-limiting enzyme in triglyceride hydrolysis, is expressed and active in beta-cells.

    Science.gov (United States)

    Mulder, H; Holst, L S; Svensson, H; Degerman, E; Sundler, F; Ahrén, B; Rorsman, P; Holm, C

    1999-01-01

    Triglycerides in the beta-cell may be important for stimulus-secretion coupling, through provision of a lipid-derived signal, and for pathogenetic events in NIDDM, where lipids may adversely affect beta-cell function. In adipose tissues, hormone-sensitive lipase (HSL) is rate-limiting in triglyceride hydrolysis. Here, we investigated whether this enzyme is also expressed and active in beta-cells. Northern blot analysis and reverse transcription-polymerase chain reaction demonstrated that HSL is expressed in rat islets and in the clonal beta-cell lines INS-1, RINm5F, and HIT-T15. Western blot analysis identified HSL in mouse and rat islets and the clonal beta-cells. In mouse and rat, immunocytochemistry showed a predominant occurrence of HSL in beta-cells, with a presumed cytoplasmic localization. Lipase activity in homogenates of the rodent islets and clonal beta-cells constituted 2.1 +/- 0.6% of that in adipocytes; this activity was immunoinhibited by use of antibodies to HSL. The established HSL expression and activity in beta-cells offer a mechanism whereby lipids are mobilized from intracellular stores. Because HSL in adipocytes is activated by cAMP-dependent protein kinase (PKA), PKA-regulated triglyceride hydrolysis in beta-cells may participate in the regulation of insulin secretion, possibly by providing a lipid-derived signal, e.g., long-chain acyl-CoA and diacylglycerol.

  4. Assessing adrenocortical activity by determining levels of urinary free cortisol and urinary 6 beta-hydroxycortisol.

    Science.gov (United States)

    Nakamura, J; Yakata, M

    1989-03-01

    A comparative study of urinary free cortisol and urinary 6 beta-hydroxycortisol levels as a diagnostic test for hypercortisolemic states was carried out by measuring the excretion in 24-h specimens from 289 apparently healthy subjects and 10 Cushing patients. The diurnal variations of both variables were examined in normal subjects and subjects with altered adrenal activities. Two of the 289 apparently normal subjects had high values of urinary free cortisol; one had a high, the other a normal 6 beta-hydroxycortisol level; they were later diagnosed as having Cushing's syndrome and infertility, respectively. Three other subjects had high values of the urinary variables, but during 5 years of follow-up did not show any clinical evidence of hypercortisolism. The two urinary variables gave no false-negative results in the Cushing patients. The diurnal variation revealed that levels of 6 beta-hydroxycortisol change in parallel with those of free cortisol in normal subjects and in subjects with altered adrenal activities. However, the ratio of 6 beta-hydroxycortisol to free cortisol during the diurnal variation varied from low values when free cortisol levels were high to high values when free cortisol levels were low. In normal subjects, 1 mg of dexamethasone taken orally at 23.00 h completely suppressed the levels of both variables on the following day. It is concluded that urinary 6 beta-hydroxycortisol is correlated to urinary free cortisol so that measurement of urinary 6 beta-hydroxycortisol levels can be used as a diagnostic test for hypercortisolism in a way comparable to the method using urinary free cortisol.

  5. Concurrent Transient Activation of Wnt/{beta}-Catenin Pathway Prevents Radiation Damage to Salivary Glands

    Energy Technology Data Exchange (ETDEWEB)

    Hai Bo; Yang Zhenhua; Shangguan Lei; Zhao Yanqiu [Institute for Regenerative Medicine, Scott and White Hospital, Molecular and Cellular Medicine Department, Texas A and M Health Science Center, Temple, Texas (United States); Boyer, Arthur [Department of Radiology, Scott and White Hospital, Temple, Texas (United States); Liu, Fei, E-mail: fliu@medicine.tamhsc.edu [Institute for Regenerative Medicine, Scott and White Hospital, Molecular and Cellular Medicine Department, Texas A and M Health Science Center, Temple, Texas (United States)

    2012-05-01

    Purpose: Many head and neck cancer survivors treated with radiotherapy suffer from permanent impairment of their salivary gland function, for which few effective prevention or treatment options are available. This study explored the potential of transient activation of Wnt/{beta}-catenin signaling in preventing radiation damage to salivary glands in a preclinical model. Methods and Materials: Wnt reporter transgenic mice were exposed to 15 Gy single-dose radiation in the head and neck area to evaluate the effects of radiation on Wnt activity in salivary glands. Transient Wnt1 overexpression in basal epithelia was induced in inducible Wnt1 transgenic mice before together with, after, or without local radiation, and then saliva flow rate, histology, apoptosis, proliferation, stem cell activity, and mRNA expression were evaluated. Results: Radiation damage did not significantly affect activity of Wnt/{beta}-catenin pathway as physical damage did. Transient expression of Wnt1 in basal epithelia significantly activated the Wnt/{beta}-catenin pathway in submandibular glands of male mice but not in those of females. Concurrent transient activation of the Wnt pathway prevented chronic salivary gland dysfunction following radiation by suppressing apoptosis and preserving functional salivary stem/progenitor cells. In contrast, Wnt activation 3 days before or after irradiation did not show significant beneficial effects, mainly due to failure to inhibit acute apoptosis after radiation. Excessive Wnt activation before radiation failed to inhibit apoptosis, likely due to extensive induction of mitosis and up-regulation of proapoptosis gene PUMA while that after radiation might miss the critical treatment window. Conclusion: These results suggest that concurrent transient activation of the Wnt/{beta}-catenin pathway could prevent radiation-induced salivary gland dysfunction.

  6. Reduced 11beta-hydroxysteroid dehydrogenase activity in patients with the nephrotic syndrome.

    Science.gov (United States)

    Vogt, B; Dick, B; N'Gankam, V; Frey, F J; Frey, B M

    1999-02-01

    Patients with the nephrotic syndrome (NS) exhibit abnormal renal sodium retention which cannot completely explained by a secondary hyperaldosteronism due to reduced renal perfusion. As an alternative mechanism to explain this phenomenon we postulate a cortisol-mediated mineralocorticoid effect as a consequence of a reduced activity of 11beta-hydroxysteroid dehydrogenase (11beta-HSD). A down-regulation of 11beta-HSD, i.e. of the shuttle of active to inactive glucocorticosteroids, has been shown to cause mineralocorticoid effects. Therefore we investigated the activity of 11beta-HSD by measuring the urinary ratio of (tetrahydrocortisol + 5alpha-tetrahydrocortisol)/tetrahydrocortisone [(THF+5alpha-THF)/THE] by gas-chromatography in 29 NS patients with biopsy-proven glomerulonephritis and 29 healthy control subjects. The ratio of (THF+5alpha-THF)/THE was higher in NS patients (median 1.49, range 0.45-4.07) than in the control subjects (0.98, 0.60-1.36; pnew mechanism contributing to the exaggerated sodium retention in patients with the NS.

  7. The activity of wild type and mutant phenylalanine hydroxylase with respect to the C-oxidation of phenylalanine and the S-oxidation of S-carboxymethyl-L-cysteine.

    Science.gov (United States)

    Steventon, Glyn B; Mitchell, Stephen C; Pérez, Belen; Desviat, Lourdes R; Ugarte, Magdalena

    2009-01-01

    The involvement of the enzyme, phenylalanine hydroxylase (PAH), in the S-oxidation of S-carboxymethyl-L-cysteine (SCMC) is now firmly established in man and rat. However, the underlying role of the molecular genetics of PAH in dictating and influencing the S-oxidation polymorphism of SCMC metabolism is as yet unknown. In this work we report that the S-oxidation of SCMC was dramatically reduced in the tetrahydrobiopterin (BH(4)) responsive mutant PAH proteins (I65T, R68S, R261Q, V388M and Y414C) with these enzymes possessing between 1.2% and 2.0% of the wild type PAH activity when SCMC was used as substrate. These same mutant proteins express between 23% and 76% of the wild type PAH activity when phenylalanine was used as the substrate. The PAH mutant proteins (R158Q, I174T and R408W) that result in the classical phenylketonuria (PKU) phenotype expressing 0.2-1.8% of the wild type PAH activity when using phenylalanine as substrate were found to have phenylalanine as substrate have <2.0% residual activity when SCMC was used as a substrate. This investigation has led to the hypothesis that the S-oxidation polymorphism in man is a consequence of an individual carrying one mutant PAH allele which has resulted in the loss of the ability of the residual PAH protein to undertake the S-oxidation of SCMC in vivo.

  8. Bace1 activity impairs neuronal glucose metabolism: rescue by beta-hydroxybutyrate and lipoic acid

    Directory of Open Access Journals (Sweden)

    John A Findlay

    2015-10-01

    Full Text Available Glucose hypometabolism and impaired mitochondrial function in neurons have been suggested to play early and perhaps causative roles in Alzheimer’s disease (AD pathogenesis. Activity of the aspartic acid protease, beta-site amyloid precursor protein (APP cleaving enzyme 1 (BACE1, responsible for beta amyloid peptide generation, has recently been demonstrated to modify glucose metabolism. We therefore examined, using a human neuroblastoma (SH-SY5Y cell line, whether increased BACE1 activity is responsible for a reduction in cellular glucose metabolism. Overexpression of active BACE1, but not a protease-dead mutant BACE1, protein in SH-SY5Y cells reduced glucose oxidation and the basal oxygen consumption rate, which was associated with a compensatory increase in glycolysis. Increased BACE1 activity had no effect on the mitochondrial electron transfer process but was found to diminish substrate delivery to the mitochondria by inhibition of key mitochondrial decarboxylation reaction enzymes. This BACE1 activity-dependent deficit in glucose oxidation was alleviated by the presence of beta hydroxybutyrate or α-lipoic acid. Consequently our data indicate that raised cellular BACE1 activity drives reduced glucose oxidation in a human neuronal cell line through impairments in the activity of specific tricarboxylic acid cycle enzymes. Because this bioenergetic deficit is recoverable by neutraceutical compounds we suggest that such agents, perhaps in conjunction with BACE1 inhibitors, may be an effective therapeutic strategy in the early-stage management or treatment of AD.

  9. BACE1 activity impairs neuronal glucose oxidation: rescue by beta-hydroxybutyrate and lipoic acid.

    Science.gov (United States)

    Findlay, John A; Hamilton, David L; Ashford, Michael L J

    2015-01-01

    Glucose hypometabolism and impaired mitochondrial function in neurons have been suggested to play early and perhaps causative roles in Alzheimer's disease (AD) pathogenesis. Activity of the aspartic acid protease, beta-site amyloid precursor protein (APP) cleaving enzyme 1 (BACE1), responsible for beta amyloid peptide generation, has recently been demonstrated to modify glucose metabolism. We therefore examined, using a human neuroblastoma (SH-SY5Y) cell line, whether increased BACE1 activity is responsible for a reduction in cellular glucose metabolism. Overexpression of active BACE1, but not a protease-dead mutant BACE1, protein in SH-SY5Y cells reduced glucose oxidation and the basal oxygen consumption rate, which was associated with a compensatory increase in glycolysis. Increased BACE1 activity had no effect on the mitochondrial electron transfer process but was found to diminish substrate delivery to the mitochondria by inhibition of key mitochondrial decarboxylation reaction enzymes. This BACE1 activity-dependent deficit in glucose oxidation was alleviated by the presence of beta hydroxybutyrate or α-lipoic acid. Consequently our data indicate that raised cellular BACE1 activity drives reduced glucose oxidation in a human neuronal cell line through impairments in the activity of specific tricarboxylic acid cycle enzymes. Because this bioenergetic deficit is recoverable by neutraceutical compounds we suggest that such agents, perhaps in conjunction with BACE1 inhibitors, may be an effective therapeutic strategy in the early-stage management or treatment of AD.

  10. Extraction of single-trial cortical beta oscillatory activities in EEG signals using empirical mode decomposition

    Directory of Open Access Journals (Sweden)

    Wu Chi-Hsun

    2010-06-01

    Full Text Available Abstract Background Brain oscillatory activities are stochastic and non-linearly dynamic, due to their non-phase-locked nature and inter-trial variability. Non-phase-locked rhythmic signals can vary from trial-to-trial dependent upon variations in a subject's performance and state, which may be linked to fluctuations in expectation, attention, arousal, and task strategy. Therefore, a method that permits the extraction of the oscillatory signal on a single-trial basis is important for the study of subtle brain dynamics, which can be used as probes to study neurophysiology in normal brain and pathophysiology in the diseased. Methods This paper presents an empirical mode decomposition (EMD-based spatiotemporal approach to extract neural oscillatory activities from multi-channel electroencephalograph (EEG data. The efficacy of this approach manifests in extracting single-trial post-movement beta activities when performing a right index-finger lifting task. In each single trial, an EEG epoch recorded at the channel of interest (CI was first separated into a number of intrinsic mode functions (IMFs. Sensorimotor-related oscillatory activities were reconstructed from sensorimotor-related IMFs chosen by a spatial map matching process. Post-movement beta activities were acquired by band-pass filtering the sensorimotor-related oscillatory activities within a trial-specific beta band. Signal envelopes of post-movement beta activities were detected using amplitude modulation (AM method to obtain post-movement beta event-related synchronization (PM-bERS. The maximum amplitude in the PM-bERS within the post-movement period was subtracted by the mean amplitude of the reference period to find the single-trial beta rebound (BR. Results The results showed single-trial BRs computed by the current method were significantly higher than those obtained from conventional average method (P Conclusions The EMD-based method is effective for artefact removal and extracting

  11. Mx1 and IP-10: biomarkers to measure IFN-beta activity in mice following gene-based delivery.

    Science.gov (United States)

    Petry, Harald; Cashion, Linda; Szymanski, Paul; Ast, Oliver; Orme, Ann; Gross, Cynthia; Bauzon, Maxine; Brooks, Alan; Schaefer, Caralee; Gibson, Heather; Qian, Husheng; Rubanyi, Gabor M; Harkins, Richard N

    2006-10-01

    Recombinant interferon-beta (IFN-beta) protein is used successfully for the treatment of multiple sclerosis (MS). Gene therapy might be an alternative approach to overcome drawbacks occurring with IFN-beta protein therapy. A critical issue in developing a new approach is detection of biologically active IFN-beta in preclinical models. The goal of the present study was to determine if Mx1 and IP-10, which are known to be activated after IFN-beta treatment in humans, can be used as biomarkers in mice. In three in vivo experiments, the correlation between different methods of murine IFN-beta (MuIFN-beta) delivery and biomarker induction was studied: (1) bolus protein delivery by intravenous (i.v.) or intramuscular (i.m.) injection, (2) gene-based delivery of IFN- beta by i.m. injection of plasmid DNA, followed by electroporation, and (3) gene-based delivery of IFN-beta by i.m. injection of adenovirus-associated type 1 (AAV1). Short-term induction of Mx1 mRNA and IP-10 was observed after treatment with bolus MuIFN-beta protein. Long-term induction of both biomarkers was observed after IFN-beta plasmid DNA delivery or when AAV1 was used as the vector. The experiments demonstrate that gene-based delivery provides sustained levels of IFN-beta compared with bolus protein injection and that Mx1 RNA and IP-10 can be used to monitor biologically active circulating plasma MuIFN-beta protein in mice.

  12. Comparison of Antioxidant and Antibacterial Activities of Free and Encapsulated Garlic Oil with Beta-cyclodextrin

    Directory of Open Access Journals (Sweden)

    Khadijeh Khoshtinat

    2016-10-01

    Full Text Available Background and Objectives: Application of garlic oil in food industry can be improved by encapsulation. There is no study about the formation of inclusion complex of garlic oil by beta-cyclodextrin. The aim of the present study is comparison of the antioxidant and antibacterial activities of free and encapsulated garlic oil with beta-cyclodextrin.Materials and Methods: Antioxidant activity was determined by 1, 1- diphenyl-2- picryl-hydrazyl assay, and antibacterial properties by agar well diffusion, minimum inhibitory concentration, minimum bactericidal concentration and bacterial growth assay. Statistical analysis was performed by Minitab statistical software.Results and conclusion: Garlic oil had poor antioxidant activity (EC50, 5222 µg ml-1 and EC50 because garlic oil/beta-cyclodextrin (containing 1495 µg ml-1 released garlic oil was achieved after 5 h and 25 min. Agar well diffusion showed no inhibition zone on Muller Hinton Agar for garlic oil and garlic oil/betacyclodextrin (with initial release (shaking at 150 rpm for 24 h at 37ºC and without initial release. Staphylococcus aureus was the most susceptible bacterium to garlic oil, and garlic oil/beta-cyclodextrin with and without initial release (minimum inhibitory concentration 10-5 , 10-4 and 10-3 % w v -1 , respectively; however, Bacillus cereus was the most resistant. The effect of initial release for garlic oil/betacyclodextrin on inhibiting the growth of all four bacteria was significant. There was no significant difference (P>0.05 between the inhibitory effect of garlic oil and garlic oil/beta-cyclodextrin with initial release on Staphylococcus aureus and Bacillus cereus, also Salmonella entrica and Escherichia coli. Garlic oil showed a weak antioxidant activity in 1, 1- diphenyl-2-picryl-hydrazyl assay. Garlic oil and its complex were not able to penetrate to the solid media; therefore, no inhibition zone and no antibacterial activity in the agar well diffusion assay were

  13. Beta-AMYLASE4, a noncatalytic protein required for starch breakdown, acts upstream of three active beta-amylases in Arabidopsis chloroplasts.

    Science.gov (United States)

    Fulton, Daniel C; Stettler, Michaela; Mettler, Tabea; Vaughan, Cara K; Li, Jing; Francisco, Perigio; Gil, Manuel; Reinhold, Heike; Eicke, Simona; Messerli, Gaëlle; Dorken, Gary; Halliday, Karen; Smith, Alison M; Smith, Steven M; Zeeman, Samuel C

    2008-04-01

    This work investigated the roles of beta-amylases in the breakdown of leaf starch. Of the nine beta-amylase (BAM)-like proteins encoded in the Arabidopsis thaliana genome, at least four (BAM1, -2, -3, and -4) are chloroplastic. When expressed as recombinant proteins in Escherichia coli, BAM1, BAM2, and BAM3 had measurable beta-amylase activity but BAM4 did not. BAM4 has multiple amino acid substitutions relative to characterized beta-amylases, including one of the two catalytic residues. Modeling predicts major differences between the glucan binding site of BAM4 and those of active beta-amylases. Thus, BAM4 probably lost its catalytic capacity during evolution. Total beta-amylase activity was reduced in leaves of bam1 and bam3 mutants but not in bam2 and bam4 mutants. The bam3 mutant had elevated starch levels and lower nighttime maltose levels than the wild type, whereas bam1 did not. However, the bam1 bam3 double mutant had a more severe phenotype than bam3, suggesting functional overlap between the two proteins. Surprisingly, bam4 mutants had elevated starch levels. Introduction of the bam4 mutation into the bam3 and bam1 bam3 backgrounds further elevated the starch levels in both cases. These data suggest that BAM4 facilitates or regulates starch breakdown and operates independently of BAM1 and BAM3. Together, our findings are consistent with the proposal that beta-amylase is a major enzyme of starch breakdown in leaves, but they reveal unexpected complexity in terms of the specialization of protein function.

  14. EEG beta band activity is related to attention and attentional deficits in the visual performance of elderly subjects.

    Science.gov (United States)

    Gola, Mateusz; Magnuski, Mikołaj; Szumska, Izabela; Wróbel, Andrzej

    2013-09-01

    We have previously shown that beta-band EEG activity is related to attentional modulation in the visual system of cats and humans. In a separate experiment we also observed that some elderly subjects expressed beta-band power decreases during a simple visual attention task, an effect which was accompanied by low behavioral accuracy in this subgroup. Here, we conducted a detailed examination of beta power deficits in elderly subjects in comparison to young controls. In order to do so, we equalized the subjective level of task difficulty by adjusting visual stimuli presentation duration in such a way that elderly and young subjects achieved similar behavioral results. We found that: (1) beta-band power of EEG signals recorded over occipital regions in elderly and young groups is related to visual attention, as judged from increases in beta power preceding correct responses and lack of beta activity change before erroneous responses; (2) despite forming a homogeneous group when screened for dementia (MMSE), age, education level, visual correction, and speed-accuracy trade-off strategy, elderly subjects could be assigned into one of the two subgroups: high performers, who did not differ from young performers in terms of beta-band power increases, and low performers, whose beta power decreased during the most difficult attentional conditions (shortest - 3s and longest - 11s cue-target delays). These findings posit that the beta-band activity decrease recorded in low performing elderly subjects reflects difficulty in activation and deficits in sustaining attentional processes.

  15. [Induction, purification and antifungal activity of beta-1, 3-glucanase from wheat leaves].

    Science.gov (United States)

    Sun, Bin; Li, Duo-Chuan; Ci, Xiao-Yan; Guo, Run-Fang; Wang, Ying

    2004-08-01

    Treatment with mercuric chloride (0.01%), salicylic acid (10.0 mg/mL) or riboflavin (1 mmol/L) induced the beta-1, 3-glucanase activity in all the three wheat varieties i.e. 331, Kangdao 680 and Lumai 23 tested, with the strongest inductive effect on variety 331 by treatment with mercuric chloride (0.01%) for 24 h. From leaves of variety 331 treated with mercuric chloride (0.01%) for 24 h, a kind of beta-1, 3-glucanase was purified by fractional precipitation with ammonium sulphate, Phenyl-Sepharose chromatography (Phenyl-Sepharose Fast Flow), ion-exchange chromatography (DEAE-Sepharose Fast Flow) and gel-filtration chromatography (Sephacryl S-100). Through SDS-PAGE and gel filtration, the molecular weight of the purified beta-1, 3-glucanase was determined to be about 52.0-53.6 kD. The purified beta-1, 3-glucanase showed antifungal activity against both Alternaria longipes and Rhizoctonia cerealis on tested plates, and inhibited the germ tube elongation and spore germination of Verticillium dahliae and Fusarium omysporum f.sp cucumerinum.

  16. Catalytic activity of nuclear PLC-beta(1) is required for its signalling function during C2C12 differentiation.

    Science.gov (United States)

    Ramazzotti, Giulia; Faenza, Irene; Gaboardi, Gian Carlo; Piazzi, Manuela; Bavelloni, Alberto; Fiume, Roberta; Manzoli, Lucia; Martelli, Alberto M; Cocco, Lucio

    2008-11-01

    Here we report that PLC-beta(1) catalytic activity plays a role in the increase of cyclin D3 levels and induces the differentiation of C2C12 skeletal muscle cells. PLC-beta(1) mutational analysis revealed the importance of His(331) and His(378) for the catalysis. The expression of PLC-beta(1) and cyclin D3 proteins is highly induced during the process of skeletal myoblast differentiation. We have previously shown that PLC-beta(1) activates cyclin D3 promoter during the differentiation of myoblasts to myotubes, indicating that PLC-beta(1) is a crucial regulator of the mouse cyclin D3 gene. We show that after insulin treatment cyclin D3 mRNA levels are lower in cells overexpressing the PLC-beta(1) catalytically inactive form in comparison to wild type cells. We describe a novel signalling pathway elicited by PLC-beta(1) that modulates AP-1 activity. Gel mobility shift assay and supershift performed with specific antibodies indicate that the c-jun binding site is located in a cyclin D3 promoter region specifically regulated by PLC-beta(1) and that c-Jun binding activity is significantly increased by insulin and PLC-beta(1) overexpression. Mutation of AP-1 site decreased the basal cyclin D3 promoter activity and eliminated its induction by insulin and PLC-beta(1). These results hint at the fact that PLC-beta(1) catalytic activity signals a c-jun/AP-1 target gene, i.e. cyclin D3, during myogenic differentiation.

  17. N-methyl-D-aspartate antagonist activity of alpha- and beta-sulfallorphans.

    Science.gov (United States)

    Shukla, V K; Lemaire, S

    1997-01-01

    Resolved equatorial (alpha) and axial (beta) forms of S-allylmorphinans, alpha-sulfallorphan and beta-sulfallorphan, were tested for their ability to compete with the binding of phencyclidine and sigma receptor ligands to mouse brain membranes and to antagonize N-methyl-D-aspartate (NMDA)-induced convulsions in mice. alpha- and beta-sulfallorphans displayed distinct binding affinities for phencyclidine and sigma sites, inhibiting the binding of [3H]-(5R,10S)-(+)-5-methyl-10,11-dihydro-5H-dibenzo[a,d]cyclohepten++ +-5, 10-imine ([3H]MK-801) with Ki values of 2.32 and 0.13 microM and that of [3H](+)-pentazocine with Ki values of 1.97 and 1.61 microM, respectively. Intracerebroventricular administration of these compounds in mice caused dose-dependent inhibitions of NMDA-induced convulsions, but did not affect convulsions induced by (R,S)-alpha-amino-3-hydroxy-5-methylisoxazole-4-propionic acid (AMPA), kainic acid and bicuculline. alpha- and beta-sulfallorphans blocked the convulsive activity of NMDA (1 nmol/mouse; intracerebroventricular) with ED50 values of 0.48 and 0.015 nmol/mouse, as compared with 0.55, 0.039 and 0.013 nmol/mouse for dextrorphan, MK-801 and (+/-)3-(2-carboxypiperazine-4yl)propyl-1-proprionic acid, respectively. The structurally related compound, dextrallorphan, significantly but less potently blocked NMDA-induced convulsions (ED60, 2.68 nmol/mouse). At the protective doses, alpha- and beta-sulfallorphans markedly reduced NMDA- and AMPA-induced mortality without inducing locomotion and falling behavior. These results indicate that alpha- and beta-sulfallorphans are potent and selective NMDA antagonists devoid of motor side effects at protective doses.

  18. Effect of clavulanic acid on activity of beta-lactam antibiotics in Serratia marcescens isolates producing both a TEM beta-lactamase and a chromosomal cephalosporinase.

    Science.gov (United States)

    Bush, K; Flamm, R K; Ohringer, S; Singer, S B; Summerill, R; Bonner, D P

    1991-01-01

    An isolate of Serratia marcescens that produced both an inducible chromosomal and a plasmid-mediated TEM-1 beta-lactamase was resistant to ampicillin and amoxicillin and also demonstrated decreased susceptibility to extended-spectrum beta-lactam antibiotics (ESBAs). Clavulanic acid did not lower the MICs of the ESBAs, but it decreased the MICs of the penicillins. The TEM-1-producing plasmid was transferred to a more susceptible S. marcescens strain that produced a well-characterized inducible chromosomal beta-lactamase. The MICs of the ESBAs remained at a low level for the transconjugant. Ampicillin and amoxicillin which were good substrates for the plasmid-mediated enzyme, were not well hydrolyzed by the chromosomal enzymes; the ESBAs were hydrolyzed slowly by all the enzymes. When each of the S. marcescens strains was grown with these beta-lactam antibiotics, at least modest increases in chromosomal beta-lactamase activity were observed. When organisms were grown in the presence of clavulanic acid and an ESBA, no enhanced induction was observed. The increases in the MICs of the ESBAs observed for the initial clinical isolate may have been due to a combination of low inducibility, slow hydrolysis, and differences in permeability between the S. marcescens isolates. When clavulanic acid and a penicillin were added to strains that produced both a plasmid-mediated TEM and a chromosomal beta-lactamase, much higher levels of chromosomal beta-lactamase activity were present than were observed in cultures induced by the penicillin alone. This was due to the higher levels of penicillin that were available for induction as a result of inhibition of the TEM enzyme by clavulanate. Images PMID:1803992

  19. Effects of methoxychlor and its metabolite 2,2-bis(p-hydroxyphenyl)-1,1,1-trichloroethane on human and rat 17α-hydroxylase/17,20-lyase activity.

    Science.gov (United States)

    Ye, Leping; Chen, Xiaomin; Li, Xiaoheng; Zhu, Qiqi; Yu, Lin; Guo, Jingjing; Chen, Bingbing; Akingbemi, Benson T; Ge, Ren-Shan; Li, Hui

    2014-03-21

    Exposure to methoxychlor, an agricultural pesticide, has been associated with reduced testicular androgen secretion. However, methoxychlor is converted to 2,2-bis-(p-hydroxyphenyl)-1,1,1-trichloroethane (HPTE) in the liver, which then acts as its biologically active metabolite. Both methoxychlor and HPTE have been credited with estrogenic properties and have a weak anti-androgenic activity. However, the exact mechanisms of steroidogenic enzyme inhibition remain to be clarified. In the present study, human and rat testis microsomes were employed to investigate the inhibitory activities of methoxychlor and HPTE on 17α-hydroxylase/17,20-lyase (CYP17A1). The CYP17A1 enzyme is critical for androgen biosynthesis and catalyzes conversion of progesterone into androstenedione. The results demonstrated that HPTE directly inhibited human and rat CYP17A1 activities, while methoxychlor had no effects on this enzyme activity even at a concentration of 100 μM. The IC50 values of HPTE were 1.13±0.10 (human) and 6.87±0.13 μM (rat), respectively. When HPTE was incubated with rat immature Leydig cells, it also inhibited CYP17A1 activity with an IC50 value of 6.29±0.1 μM. Results of enzyme inhibition were supported by the observation that HPTE inhibited luteinizing hormone-stimulated 5α-androstane-3α,17β-diol and testosterone secretion by immature Leydig cells with IC50 values of 6.61±0.03 and 3.78±0.003 μM, respectively. The mode of action of HPTE on CYP17A1 activity was determined to be uncompetitive with the substrate progesterone. In conclusion, HPTE, the metabolite of MXC, directly inhibited human and rat testis CYP17A1 activities.

  20. Direct Evidence for a Phenylalanine Site in the Regulatory Domain of Phenylalanine Hydroxylase

    OpenAIRE

    Li, Jun; Ilangovan, Udayar; Daubner, S. Colette; Hinck, Andrew P.; Fitzpatrick, Paul F.

    2010-01-01

    The hydroxylation of phenylalanine to tyrosine by the liver enzyme phenylalanine hydroxylase is regulated by the level of phenylalanine. Whether there is a distinct allosteric binding site for phenylalanine outside of the active site has been unclear. The enzyme contains an N-terminal regulatory domain that extends through Thr117. The regulatory domain of rat phenylalanine hydroxylase was expressed in E. coli. The purified protein behaves as a dimer on a gel filtration column. In the presence...

  1. ANTIOXIDANT AND ANTI-INFLAMMATORY ACTIVITY OF ETHANOLIC EXTRACT OF BETA VULGARIS LINN. ROOTS

    OpenAIRE

    Chakole, Rita; Zade, Shubhangi; Charde, Manoj

    2011-01-01

    The present study deals with evaluation of antioxidant and anti-inflammatory activity of ethanolic extract of Beta Vulgaris roots. The ethanolic extract was subjected to screen forantioxidant activity using DPPH radical scavenging method. The anti-inflammatory activity was carried out by using carageenan induced rat paw edema method. The tested extract ofdifferent dilutions in range 200 µg/ml to 1000 µg/ml shows activity in range of 4.34% to 18.55%. The extract shows prominent anti-inflamma...

  2. Cannabis and cocaine decrease cognitive impulse control and functional corticostriatal connectivity in drug users with low activity DBH genotypes

    NARCIS (Netherlands)

    Ramaekers, J.G.; van Wel, J.H.; Spronk, D.; Franke, B.; Kenis, G.; Toennes, S.W.; Kuypers, K.P.; Theunissen, E.L.; Stiers, P.; Verkes, R.J.

    2016-01-01

    The dopamine beta-hydroxylase (DbetaH) enzyme transforms dopamine into noradrenaline. We hypothesized that individuals with low activity DBH genotypes (rs1611115 CT/TT) are more sensitive to the influence of cannabis and cocaine on cognitive impulse control and functional connectivity in the limbic

  3. Porcine reproductive and respiratory syndrome virus nonstructural protein 1beta modulates host innate immune response by antagonizing IRF3 activation.

    Science.gov (United States)

    Beura, Lalit K; Sarkar, Saumendra N; Kwon, Byungjoon; Subramaniam, Sakthivel; Jones, Clinton; Pattnaik, Asit K; Osorio, Fernando A

    2010-02-01

    Porcine reproductive and respiratory syndrome virus (PRRSV) infection of swine leads to a serious disease characterized by a delayed and defective adaptive immune response. It is hypothesized that a suboptimal innate immune response is responsible for the disease pathogenesis. In the study presented here we tested this hypothesis and identified several nonstructural proteins (NSPs) with innate immune evasion properties encoded by the PRRS viral genome. Four of the total ten PRRSV NSPs tested were found to have strong to moderate inhibitory effects on beta interferon (IFN-beta) promoter activation. The strongest inhibitory effect was exhibited by NSP1 followed by, NSP2, NSP11, and NSP4. We focused on NSP1alpha and NSP1beta (self-cleavage products of NSP1 during virus infection) and NSP11, three NSPs with strong inhibitory activity. All of three proteins, when expressed stably in cell lines, strongly inhibited double-stranded RNA (dsRNA) signaling pathways. NSP1beta was found to inhibit both IFN regulatory factor 3 (IRF3)- and NF-kappaB-dependent gene induction by dsRNA and Sendai virus. Mechanistically, the dsRNA-induced phosphorylation and nuclear translocation of IRF3 were strongly inhibited by NSP1beta. Moreover, when tested in a porcine myelomonocytic cell line, NSP1beta inhibited Sendai virus-mediated activation of porcine IFN-beta promoter activity. We propose that this NSP1beta-mediated subversion of the host innate immune response plays an important role in PRRSV pathogenesis.

  4. LXR/RXR ligand activation enhances basolateral efflux of beta-sitosterol in CaCo-2 cells.

    Science.gov (United States)

    Field, F Jeffrey; Born, Ella; Mathur, Satya N

    2004-05-01

    To examine whether intestinal ABCA1 was responsible for the differences observed between cholesterol and beta-sitosterol absorption, ABCA1-facilitated beta-sitosterol efflux was investigated in CaCo-2 cells following liver X receptor/retinoid X receptor (LXR/RXR) activation. Both the LXR agonist T0901317 and the natural RXR/LXR agonists 22-hydroxycholesterol and 9-cis retinoic acid enhanced the basolateral efflux of beta-sitosterol without altering apical efflux. LXR-mediated enhanced beta-sitosterol efflux occurred between 6 h and 12 h after activation, suggesting that transcription, protein synthesis, and trafficking was likely necessary prior to facilitating efflux. The transcription inhibitor actinomycin D prevented the increase in beta-sitosterol efflux by T0901317. Glybenclamide, an inhibitor of ABCA1 activity, and arachidonic acid, a fatty acid that interferes with LXR activation, also prevented beta-sitosterol efflux in response to the LXR ligand activation. Influx of beta-sitosterol mass did not alter the basolateral or apical efflux of the plant sterol, nor did it alter ABCA1, ABCG1, ABCG5, or ABCG8 gene expression or ABCA1 mass. Similar to results observed with intestinal ABCA1-facilitated cholesterol efflux, LXR/RXR ligand activation enhanced the basolateral efflux of beta-sitosterol without affecting apical efflux. The results suggest that ABCA1 does not differentiate between cholesterol and beta-sitosterol and thus is not responsible for the selectivity of sterol absorption by the intestine. ABCA1, however, may play a role in beta-sitosterol absorption.

  5. Activation of the human beta interferon gene by the adenovirus type 12 E1B gene

    Energy Technology Data Exchange (ETDEWEB)

    Shiroki, K.; Toth, M.

    1988-01-01

    The transcription of endogenous beta interferon mRNA was activated in human embryo kidney (HEK) cells infected with adenovirus 12 (Ad12) but was activated only inefficiently or not at all in HEK cells infected with Ad5 and rc-1 (Ad5 dl312 containing the Ad12 E1A region). The analysis with Ad12 mutants showed that Ad12 E1B products, especially the 19K protein, were important for the expression of the endogenous beta interferon gene and Ad12 E1A products were not involved in the expression. The expression of exogeneously transfected pIFN-CAT (a hybrid plasmid having the human beta interferon promoter fused with the CAT gene) was activated in HEK and chicken embryo fibroblast (CEF) cells infected with either Ad12 or Ad5. The analysis of cotransfection of CEF cells with pIFN-CAT and plasmids containing fragments of Ad12 or Ad5 DNA showed that Ad12 or Ad5 E1B (possibly the 19K protein) was and E1A was not involved in the expression of the exogenous pIFN-CAT.

  6. Beta and gamma oscillatory activities associated with olfactory memory tasks: Different rhythms for different functional networks?

    Directory of Open Access Journals (Sweden)

    Claire eMartin

    2014-06-01

    Full Text Available Olfactory processing in behaving animals, even at early stages, is inextricable from top down influences associated with odor perception. The anatomy of the olfactory network (olfactory bulb, piriform and entorhinal cortices and its unique direct access to the limbic system makes it particularly attractive to study how sensory processing could be modulated by learning and memory. Moreover, olfactory structures have been early reported to exhibit oscillatory population activities easy to capture through local field potential recordings. An attractive hypothesis is that neuronal oscillations would serve to ‘bind’ distant structures to reach a unified and coherent perception. In relation to this hypothesis, we will assess the functional relevance of different types of oscillatory activity observed in the olfactory system of behaving animals. This review will focus primarily on two types of oscillatory activities: beta (15-40 Hz and gamma (60-100 Hz. While gamma oscillations are dominant in the olfactory system in the absence of odorant, both beta and gamma rhythms have been reported to be modulated depending on the nature of the olfactory task. Studies from the authors of the present review and other groups brought evidence for a link between these oscillations and behavioral changes induced by olfactory learning. However, differences in studies led to divergent interpretations concerning the respective role of these oscillations in olfactory processing. Based on a critical reexamination of those data, we propose hypotheses on the functional involvement of beta and gamma oscillations for odor perception and memory.

  7. Increased CRE-binding activity and tryptophan hydroxylase mRNA expression induced by 3,4-methylenedioxymethamphetamine (MDMA, "ecstasy") in the rat frontal cortex but not in the hippocampus.

    Science.gov (United States)

    García-Osta, Ana; Del Río, Joaquín; Frechilla, Diana

    2004-07-26

    A single administration of either 3,4-methylenedioxymethamphetamine (MDMA, "ecstasy") or p-chloroamphetamine (PCA) produced a rapid and marked reduction of serotonin (5-HT) content in rat frontal cortex and hippocampus. In the cortex of MDMA-treated rats, 5-HT levels returned to control values 48 h after drug administration. This recovery was correlated with an induction of CRE-binding activity and an enhanced expression of tryptophan hydroxylase (TPH) mRNA, the rate-limiting enzyme in 5-HT biosynthesis, suggesting that MDMA may up-regulate the TPH gene through a CREB-dependent mechanism. In the cortex of PCA-treated rats, neither a recovery of 5-HT levels nor changes in DNA-binding or TPH mRNA were found at the same time point. In the hippocampus of rats receiving either PCA or MDMA a decrease in TPH mRNA levels was found at all times, along with a reduced CRE-binding at the 8-h time point. The results show region-specific effects of MDMA. In the frontal cortex, the increased TPH expression suggests a compensatory response to MDMA-induced loss of serotonergic function.

  8. Identification of phenylalanine 3-hydroxylase for meta-tyrosine biosynthesis.

    Science.gov (United States)

    Zhang, Wenjun; Ames, Brian D; Walsh, Christopher T

    2011-06-21

    Phenylalanine hydroxylase (PheH) is an iron(II)-dependent enzyme that catalyzes the hydroxylation of aromatic amino acid l-phenylalanine (L-Phe) to l-tyrosine (L-Tyr). The enzymatic modification has been demonstrated to be highly regiospecific, forming proteinogenic para-Tyr (p-Tyr) exclusively. Here we biochemically characterized the first example of a phenylalanine 3-hydroxylase (Phe3H) that catalyzes the synthesis of meta-Tyr (m-Tyr) from Phe. Subsequent mutagenesis studies revealed that two residues in the active site of Phe3H (Cys187 and Thr202) contribute to C-3 rather than C-4 hydroxylation of the phenyl ring. This work sets the stage for the mechanistic and structural study of regiospecific control of the substrate hydroxylation by PheH.

  9. HIF hydroxylase pathways in cardiovascular physiology and medicine.

    Science.gov (United States)

    Bishop, Tammie; Ratcliffe, Peter J

    2015-06-19

    Hypoxia inducible factors (HIFs) are α/β heterodimeric transcription factors that direct multiple cellular and systemic responses in response to changes in oxygen availability. The oxygen sensitive signal is generated by a series of iron and 2-oxoglutarate-dependent dioxygenases that catalyze post-translational hydroxylation of specific prolyl and asparaginyl residues in HIFα subunits and thereby promote their destruction and inactivation in the presence of oxygen. In hypoxia, these processes are suppressed allowing HIF to activate a massive transcriptional cascade. Elucidation of these pathways has opened several new fields of cardiovascular research. Here, we review the role of HIF hydroxylase pathways in cardiac development and in cardiovascular control. We also consider the current status, opportunities, and challenges of therapeutic modulation of HIF hydroxylases in the therapy of cardiovascular disease.

  10. Liquid argon as active shielding and coolant for bare germanium detectors. A novel background suppression method for the GERDA 0{nu}{beta}{beta} experiment

    Energy Technology Data Exchange (ETDEWEB)

    Peiffer, J.P.

    2007-07-25

    Two of the most important open questions in particle physics are whether neutrinos are their own anti-particles (Majorana particles) as required by most extensions of the StandardModel and the absolute values of the neutrino masses. The neutrinoless double beta (0{nu}{beta}{beta}) decay, which can be investigated using {sup 76}Ge (a double beta isotope), is the most sensitive probe for these properties. There is a claim for an evidence for the 0{nu}{beta}{beta} decay in the Heidelberg-Moscow (HdM) {sup 76}Ge experiment by a part of the HdM collaboration. The new {sup 76}Ge experiment Gerda aims to check this claim within one year with 15 kg.y of statistics in Phase I at a background level of {<=}10{sup -2} events/(kg.keV.y) and to go to higher sensitivity with 100 kg.y of statistics in Phase II at a background level of {<=}10{sup -3} events/(kg.keV.y). In Gerda bare germanium semiconductor detectors (enriched in {sup 76}Ge) will be operated in liquid argon (LAr). LAr serves as cryogenic coolant and as high purity shielding against external background. To reach the background level for Phase II, new methods are required to suppress the cosmogenic background of the diodes. The background from cosmogenically produced {sup 60}Co is expected to be {proportional_to}2.5.10{sup -3} events/(kg.keV.y). LAr scintillates in UV ({lambda}=128 nm) and a novel concept is to use this scintillation light as anti-coincidence signal for background suppression. In this work the efficiency of such a LAr scintillation veto was investigated for the first time. In a setup with 19 kg active LAr mass a suppression of a factor 3 has been achieved for {sup 60}Co and a factor 17 for {sup 232}Th around Q{sub {beta}}{sub {beta}} = 2039 keV. This suppression will further increase for a one ton active volume (factor O(100) for {sup 232}Th and {sup 60}Co). LAr scintillation can also be used as a powerful tool for background diagnostics. For this purpose a new, very stable and robust wavelength

  11. Template-free synthesis of beta-In2S3 superstructures and their photocatalytic activity.

    Science.gov (United States)

    Amutha, R; Akilandeswari, S; Ahmmad, Bashir; Muruganandham, M; Sillanpää, Mika

    2010-12-01

    In this article, we have successfully fabricated various morphological beta-Indium sulfide (In2S3) superstructures by using indium thiocyanate complex at acidic pH. All the synthesis has been performed by a template-free, hydrothermal method at 195 degrees C for 3 h. The photocatalytic activity of synthesized In2S3 have been investigated by using UV-B (lamda = 365 nm) light with Methyl Orange dye as a model pollutant. The synthesized photocatalyst was characterized by using XRD, FE-SEM, HR-TEM, DRS spectra and nitrogen adsorption analysis. The influence of indium precursors and solvents on the morphology as well as the surface properties has also been discussed. The XRD result shows that cubic phase beta-In2S3 formed under all experimental conditions. A plausible mechanism of the In2S3 microsphere formation has been discussed based on experimental observations.

  12. Interleukin-1 beta converting enzyme requires oligomerization for activity of processed forms in vivo.

    Science.gov (United States)

    Gu, Y; Wu, J; Faucheu, C; Lalanne, J L; Diu, A; Livingston, D J; Su, M S

    1995-05-01

    Interleukin-1 beta converting enzyme (ICE) is composed of 10' (p10) and 20 kDa (p20) subunits, which are derived from a common 45 kDa precursor. Recent crystallographic studies have shown that ICE exists as a tetramer (p20/p10)2 in the crystal lattice. We provide evidence that the p10 and p20 subunits of ICE associate as oligomers in transfected COS cells. Using intragenic complementation, we show that the activity of a p10/p10 interface mutant defective in autoprocessing can be restored by co-expression with active site ICE mutants. Different active site mutants can also complement each other by oligomerization to form active ICE. These studies indicate that ICE precursor polypeptides may associate in different quaternary structures and that oligomerization is required for autoprocessing. Furthermore, integenic complementation of active site mutants of ICE and an ICE homolog restores autoprocessing activity, suggesting that hetero-oligomerization occurs between ICE homologs.

  13. Cereblon inhibits proteasome activity by binding to the 20S core proteasome subunit beta type 4.

    Science.gov (United States)

    Lee, Kwang Min; Lee, Jongwon; Park, Chul-Seung

    2012-10-26

    In humans, mutations in the gene encoding cereblon (CRBN) are associated with mental retardation. Although CRBN has been investigated in several cellular contexts, its function remains unclear. Here, we demonstrate that CRBN plays a role in regulating the ubiquitin-proteasome system (UPS). Heterologous expression of CRBN inhibited proteasome activity in a human neuroblastoma cell line. Furthermore, proteasome subunit beta type 4 (PSMB4), the β7 subunit of the 20S core complex, was identified as a direct binding partner of CRBN. These findings suggest that CRBN may modulate proteasome activity by directly interacting with the β7 subunit.

  14. IFN-beta inhibits T cell activation capacity of central nervous system APCs

    DEFF Research Database (Denmark)

    Teige, Ingrid; Liu, Yawei; Issazadeh-Navikas, Shohreh

    2006-01-01

    coculture with T cells, the effector functions of T cells are impaired as IFN-gamma, TNF-alpha, and NO productions are decreased. Induction of the T cell activation marker, CD25 is also reduced. This suppression of T cell response is cell-cell dependent, but it is not dependent on a decrease in glial...... expression of MHC class II or costimulatory molecules. We propose that IFN-beta might exert its beneficial effects mainly by reducing the Ag-presenting capacity of CNS-specific APCs, which in turn inhibits the effector functions of encephalitogenic T cells. This affect is of importance because activation...

  15. Seasonal variation in tissue estrogen-2/4-hydroxylases (EH) and in vitro effects of steroids on ovarian EH activity in the catfish Heteropneustes fossilis.

    Science.gov (United States)

    Chourasia, T K; Joy, K P

    2010-12-12

    A radiometric assay was used to measure microsomal EH activity from tritiated H(2)O formed during the conversion of [2,4 (3)H] estradiol-17β into catecholestrogens in the microsomal fractions of liver, brain and ovary of the catfish Heteropneustes fossilis. The validation data show that enzyme activity increased with incubation time, and substrate and cofactor (NADPH) concentrations, elicited temperature optima of 30-37°C and pH optima of 6.8-7.8. EH activity was strongly NADPH-dependent and in its absence only 13.48% activity was recorded. Liver recorded the highest enzyme activity, followed by brain and ovary. EH activity showed a significant seasonal variation with the peak activity in spawning phase and the lowest activity in resting phase. In the ovary, the follicular layer (theca and granulosa) elicited the highest activity over that of the denuded oocytes. Modulatory effects of steroids on ovarian enzyme activity were further demonstrated. The incubation of postvitellogenic follicles with 1, 10 or 100 nM concentrations of various steroids for 24 h produced varied effects on EH activity. Progesterone and 2-hydroxyestradiol-17β elicited strong suppressive effects on enzyme activity. Estrogens (E(1), E(2) and E(3)) suppressed the activity in a concentration-dependent manner. Among the progestins tested, 17,20α-dihydroxy-4-pregnen-3-one, the isomer of 17,20β-dihydroxy-4-pregnen-3-one (a teleost maturation-inducing steroid) showed the lowest depressing effect. Among androgens, the testosterone metabolite 11-ketotestosterone (functional teleost androgen) showed a high suppressing effect. Corticosteroids elicited low activity with cortisol suppressed the activity at higher concentrations. The study will form a basis to understand the physiological role of catecholestrogens in ovarian functions.

  16. Congenitale dopamine Beta-hydroxylase deficientie : een nieuw orthostatisch syndroom

    NARCIS (Netherlands)

    A.J. Man in 't Veld (Arie)

    1988-01-01

    textabstractSinds decennia wordt chronische autonome dysfunctie herkend als een belangrijk klinisch probleem hoewel het relatief zeldzaam is. Bradbury en Eggleston beschreven in 1925 het sindsdien naar hen genoemde syndroom als "primary postural hypotension", ook bekend als . "idiopathische orthosta

  17. Mutagenesis of a specificity-determining residue in tyrosine hydroxylase establishes that the enzyme is a robust phenylalanine hydroxylase but a fragile tyrosine hydroxylase.

    Science.gov (United States)

    Daubner, S Colette; Avila, Audrey; Bailey, Johnathan O; Barrera, Dimitrios; Bermudez, Jaclyn Y; Giles, David H; Khan, Crystal A; Shaheen, Noel; Thompson, Janie Womac; Vasquez, Jessica; Oxley, Susan P; Fitzpatrick, Paul F

    2013-02-26

    The aromatic amino acid hydroxylases tyrosine hydroxylase (TyrH) and phenylalanine hydroxylase (PheH) have essentially identical active sites; however, PheH is nearly incapable of hydroxylating tyrosine, while TyrH can readily hydroxylate both tyrosine and phenylalanine. Previous studies have indicated that Asp425 of TyrH is important in determining the substrate specificity of that enzyme [Daubner, S. C., Melendez, J., and Fitzpatrick, P. F. (2000) Biochemistry 39, 9652-9661]. Alanine-scanning mutagenesis of amino acids 423-427, a mobile loop containing Asp425, shows that only mutagenesis of Asp425 alters the activity of the enzyme significantly. Saturation mutagenesis of Asp425 results in large (up to 10(4)) decreases in the V(max) and V(max)/K(tyr) values for tyrosine hydroxylation, but only small decreases or even increases in the V(max) and V(max)/K(phe) values for phenylalanine hydroxylation. The decrease in the tyrosine hydroxylation activity of the mutant proteins is due to an uncoupling of tetrahydropterin oxidation from amino acid hydroxylation with tyrosine as the amino acid substrate. In contrast, with the exception of the D425W mutant, the extent of coupling of tetrahydropterin oxidation and amino acid hydroxylation is unaffected or increases with phenylalanine as the amino acid substrate. The decrease in the V(max) value with tyrosine as the substrate shows a negative correlation with the hydrophobicity of the amino acid residue at position 425. The results are consistent with a critical role of Asp425 being to prevent a hydrophobic interaction that results in a restricted active site in which hydroxylation of tyrosine does not occur.

  18. In-situ NMR studies of isobutane activation and exchange in zeolite beta.

    Science.gov (United States)

    Truitt, Matthew J; White, Jeffery L

    2009-04-01

    (1)H solid-state NMR techniques have been used to simultaneously detect the reactivity of both catalyst and alkane reactant protons in an in-situ experimental design. Specifically, the activation of isobutane C-H bonds by the solid acid zeolite H-Beta is directly observed while the reaction is in progress, and the rate of proton transfer between the solid catalyst surface and gaseous isobutane is quantitatively measured using isotopic (1)H/(2)H exchange methods. Arrhenius analysis of isothermal kinetic runs revealed an apparent activation barrier of 70kJ/mole for the exchange process between isobutane and the 12-membered ring H-Beta, which exceeds our previously determined value of 57kJ/mole for isobutane in the 10-membered ring H-ZSM-5 (JACS 2006, v. 128, p. 1848). Estimation of true activation energies using heat of adsorption data from the literature combined with the experimentally measured apparent E(a) suggests that the true activation barrier differs by only 6-7kJ/mole in the two catalysts. We discuss the possibility that subtle shape selectivity, or inverse shape selectivity, and lattice solvation differences between the two catalysts account for the enhanced solvation of the isobutane transition state in HZSM-5 compared to the larger channel H-Beta. In all experiments, the isobutane reagent was treated to eliminate any unsaturated impurities that might serve as initiators for carbenium-ion mechanisms, and the active catalyst was free of any organic contaminants that might serve as a source of unsaturated initiators.

  19. PDGF-BB-mediated activation of p42(MAPK) is independent of PDGF beta-receptor tyrosine phosphorylation.

    Science.gov (United States)

    Cartel, N J; Liu, J; Wang, J; Post, M

    2001-10-01

    Herein, we investigated the activity of mitogen-activated protein kinase (MAPK), a key component of downstream signaling events, which is activated subsequent to platelet-derived growth factor (PDGF)-BB stimulation. Specifically, p42(MAPK) activity peaked 60 min after addition of PDGF-BB, declined thereafter, and was determined not to be a direct or necessary component of glycosaminoglycan (GAG) synthesis. PDGF-BB also activated MAPK kinase 2 (MAPKK2) but had no effect on MAPKK1 and Raf-1 activity. Chemical inhibition of Janus kinase, phosphatidylinositol 3-kinase, Src kinase, or tyrosine phosphorylation inhibition of the PDGF beta-receptor (PDGFR-beta) did not abrogate PDGF-BB-induced p42(MAPK) activation or its threonine or tyrosine phosphorylation. A dominant negative cytoplasmic receptor for hyaluronan-mediated motility variant 4 (RHAMMv4), a regulator of MAPKK-MAPK interaction and activation, did not inhibit PDGF-BB-induced p42(MAPK) activation nor did a construct expressing PDGFR-beta with cytoplasmic tyrosines mutated to phenylalanine. However, overexpression of a dominant negative PDGFR-beta lacking the cytoplasmic signaling domain abrogated p42(MAPK) activity. These results suggest that PDGF-BB-mediated activation of p42(MAPK) requires the PDGFR-beta but is independent of its tyrosine phosphorylation.

  20. A liver X receptor (LXR)-{beta} alternative splicing variant (LXRBSV) acts as an RNA co-activator of LXR-{beta}

    Energy Technology Data Exchange (ETDEWEB)

    Hashimoto, Koshi, E-mail: khashi@med.gunma-u.ac.jp [Department of Medicine and Molecular Science, Graduate School of Medicine, Gunma University, Maebashi, Gunma 371-8511 (Japan); Ishida, Emi; Matsumoto, Shunichi; Shibusawa, Nobuyuki; Okada, Shuichi [Department of Medicine and Molecular Science, Graduate School of Medicine, Gunma University, Maebashi, Gunma 371-8511 (Japan); Monden, Tsuyoshi [Department of Endocrinology and Metabolism, Dokkyo Medical College, Mibu, Tochigi (Japan); Satoh, Tetsurou; Yamada, Masanobu; Mori, Masatomo [Department of Medicine and Molecular Science, Graduate School of Medicine, Gunma University, Maebashi, Gunma 371-8511 (Japan)

    2009-12-25

    We report the isolation and functional characterization of a novel transcriptional co-activator, termed LXRBSV. LXRBSV is an alternative splicing variant of liver X receptor (LXR)-{beta} LXRBSV has an intronic sequence between exons 2 and 3 in the mouse LXR-{beta} gene. The LXRBSV gene is expressed in various tissues including the liver and brain. We sub-cloned LXRBSV into pSG5, a mammalian expression vector, and LXRBSV in pSG5 augmented human Sterol Response Element Binding Protein (SREBP)-1c promoter activity in HepG2 cells in a ligand (TO901317) dependent manner. The transactivation mediated by LXRBSV is selective for LXR-{beta}. The LXRBSV protein was deduced to be 64 amino acids in length; however, a GAL4-LXRBSV fusion protein was not able to induce transactivation. Serial deletion constructs of LXRBSV demonstrated that the intronic sequence inserted in LXRBSV is required for its transactivation activity. An ATG mutant of LXRBSV was able to induce transactivation as wild type. Furthermore, LXRBSV functions in the presence of cycloheximide. Taken together, we have concluded that LXRBSV acts as an RNA transcript not as a protein. In the current study, we have demonstrated for the first time that an alternative splicing variant of a nuclear receptor acts as an RNA co-activator.

  1. Interleukin-1{beta} regulates cell proliferation and activity of extracellular matrix remodelling enzymes in cultured primary pig heart cells

    Energy Technology Data Exchange (ETDEWEB)

    Zitta, Karina; Brandt, Berenice [Department of Anesthesiology and Intensive Care Medicine, University Hospital Schleswig-Holstein, Campus Kiel (Germany); Wuensch, Annegret [Institute of Molecular Animal Breeding and Biotechnology, Ludwig Maximilians University, Munich (Germany); Meybohm, Patrick; Bein, Berthold; Steinfath, Markus; Scholz, Jens [Department of Anesthesiology and Intensive Care Medicine, University Hospital Schleswig-Holstein, Campus Kiel (Germany); Albrecht, Martin, E-mail: Albrecht@anaesthesie.uni-kiel.de [Department of Anesthesiology and Intensive Care Medicine, University Hospital Schleswig-Holstein, Campus Kiel (Germany)

    2010-09-03

    Research highlights: {yields} Levels of IL-1{beta} are increased in the pig myocardium after infarction. {yields} Cultured pig heart cells possess IL-1 receptors. {yields} IL-1{beta} increases cell proliferation of pig heart cells in-vitro. {yields} IL-1{beta} increases MMP-2 and MMP-9 activity in pig heart cells in-vitro. {yields} IL-1{beta} may be important for tissue remodelling events after myocardial infarction. -- Abstract: After myocardial infarction, elevated levels of interleukins (ILs) are found within the myocardial tissue and IL-1{beta} is considered to play a major role in tissue remodelling events throughout the body. In the study presented, we have established a cell culture model of primary pig heart cells to evaluate the effects of different concentrations of IL-1{beta} on cell proliferation as well as expression and activity of enzymes typically involved in tissue remodelling. Primary pig heart cell cultures were derived from three different animals and stimulated with recombinant pig IL-1{beta}. RNA expression was detected by RT-PCR, protein levels were evaluated by Western blotting, activity of matrix metalloproteinases (MMPs) was quantified by gelatine zymography and cell proliferation was measured using colorimetric MTS assays. Pig heart cells express receptors for IL-1 and application of IL-1{beta} resulted in a dose-dependent increase of cell proliferation (P < 0.05 vs. control; 100 ng/ml; 24 h). Gene expression of caspase-3 was increased by IL-1{beta} (P < 0.05 vs. control; 100 ng/ml; 3 h), and pro-caspase-3 but not active caspase was detected in lysates of pig heart cells by Western blotting. MMP-2 gene expression as well as enzymatic activities of MMP-2 and MMP-9 were increased by IL-1{beta} (P < 0.05 vs. control; 100 ng/ml; 3 h for gene expression, 48 and 72 h for enzymatic activities of MMP-2 and MMP-9, respectively). Our in vitro data suggest that IL-1{beta} plays a major role in the events of tissue remodelling in the heart. Combined

  2. Induction and characterization of a cytochrome P-450-dependent camphor hydroxylase in tissue cultures of common sage (Salvia officinalis)

    Energy Technology Data Exchange (ETDEWEB)

    Funk, C.; Croteau, R. (Washington State Univ., Pullman (United States))

    1993-04-01

    (+)-Camphor, a major monoterpene of the essential oil of common sage (Salvia officinalis), is catabolized in senescent tissue, and the pathway for the breakdown of this bicyclic ketone has been previously elucidated in sage cell-suspension cultures. In the initial step of catabolism, camphor is oxidized to 6-exo-hydroxycamphor, and the corresponding NADPH- and O[sub 2]-dependent hydroxylase activity was demonstrated in microsomal preparations of sage cells. Several well-established inhibitors of cytochrome P-450-dependent reactions, including cytochrome c, clotrimazole, and CO, inhibited the hydroxylation of camphor, and CO-dependent inhibition was partially reversed by blue light. Upon treatment of sage suspension cultures with 30 mM MnCl[sub 2], camphor-6-hydroxylase activity was induced up to 7-fold. A polypeptide with estimated molecular mass of 58 kD from sage microsomal membranes exhibited antigenic cross-reactivity in western blot experiments with two heterologous polyclonal antibodies raised against cytochrome P-450 camphor-5-exo-hydroxylase from Pseudomonas putida and cytochrome P-450 limonene-6S-hydroxylase from spearmint (Mentha spicata). Dot blotting indicated that the concentration of this polypeptide increased with camphor hydroxylase activity in microsomes of Mn[sup 2+]-induced sage cells. These results suggest that camphor-6-exo-hydroxylase from sage is a microsomal cytochrome P-450 monooxygenase that may share common properties and epitopes with bacterial and other plant monoterpene hydroxylases. 44 refs., 6 figs., 2 tabs.

  3. Beta-carotene suppression of benzophenone-sensitized lipid peroxidation in hexane through additional chain-breaking activities

    Energy Technology Data Exchange (ETDEWEB)

    Cvetkovic, Dragan [Faculty of Technology, 16000 Leskovac (Serbia); Markovic, Dejan, E-mail: dejan_markovic57@yahoo.co [Faculty of Technology, 16000 Leskovac (Serbia)

    2011-01-15

    The aim of this work is to estimate the antioxidant activity of {beta}-carotene in the presence of two different mixtures of phospholipids in hexane solution, under continuous UV-irradiation from three different ranges (UV-A, UV-B, and UV-C). {beta}-Carotene is employed to control lipid peroxidation process generated by UV-irradiation, in the presence and in the absence of selected photosensitizer, benzophenone, by scavenging the involved, created free radicals. The results show that {beta}-carotene undergoes to a substantial, probably structural dependent destruction (bleaching), highly dependent on UV-photons energy input, more expressed in the presence than in the absence of benzophenone. The additional bleaching is synchronized with the further increase in {beta}-carotene antioxidant activity in the presence of benzophenone, implying the same cause: increase in (phospholipids peroxidation) chain-breaking activities.

  4. Prolyl hydroxylase 3 inhibited the tumorigenecity of gastric cancer cells.

    Science.gov (United States)

    Cui, Lei; Qu, Jianguo; Dang, Shengchun; Mao, Zhengfa; Wang, Xuqing; Fan, Xin; Sun, Kang; Zhang, Jianxin

    2014-09-01

    Gastric cancer is one of the most common malignancies and the second leading cause of cancer-related death in the world, and it is very urgent to develop novel therapeutic strategies. Although HIF-1α is the most highly characterized target of prolyl hydroxylase 3 (PHD3), PHD3 has been shown to regulate several signal pathways independent of HIF-1α. Here, we found that the expression of PHD3 was decreased in the clinical gastric cancer samples and reversely correlated with tumor size and tumor stage. Over-expression of PHD3 in the gastric cancer cells significantly inhibited cell growth in vitro and in vivo, while knockdown the expression of PHD3 promoted the tumorigenecity of gastric cancer cells. Mechanistically, it showed that PHD3 downregulated the expression of beta-catenin and inhibited beta-catenin/T-cell factor (TCF) signaling. Taken together, our findings demonstrate that PHD3 inhibits gastric cancer by suppressing the beta-catenin/TCF signaling and PHD3 might be an important therapeutic target in gastric cancer.

  5. Impediments to enhancement of CPT-11 anticancer activity by E. coli directed beta-glucuronidase therapy.

    Science.gov (United States)

    Hsieh, Yuan-Ting; Chen, Kai-Chuan; Cheng, Chiu-Min; Cheng, Tian-Lu; Tao, Mi-Hua; Roffler, Steve R

    2015-01-01

    CPT-11 is a camptothecin analog used for the clinical treatment of colorectal adenocarcinoma. CPT-11 is converted into the therapeutic anti-cancer agent SN-38 by liver enzymes and can be further metabolized to a non-toxic glucuronide SN-38G, resulting in low SN-38 but high SN-38G concentrations in the circulation. We previously demonstrated that adenoviral expression of membrane-anchored beta-glucuronidase could promote conversion of SN-38G to SN-38 in tumors and increase the anticancer activity of CPT-11. Here, we identified impediments to effective tumor therapy with E. coli that were engineered to constitutively express highly active E. coli beta-glucuronidase intracellularly to enhance the anticancer activity of CPT-11. The engineered bacteria, E. coli (lux/βG), could hydrolyze SN-38G to SN-38, increased the sensitivity of cultured tumor cells to SN-38G by about 100 fold and selectively accumulated in tumors. However, E. coli (lux/βG) did not more effectively increase CPT-11 anticancer activity in human tumor xenografts as compared to non-engineered E. coli. SN-38G conversion to SN-38 by E. coli (lux/βG) appeared to be limited by slow uptake into bacteria as well as by segregation of E. coli in necrotic regions of tumors that may be relatively inaccessible to systemically-administered drug molecules. Studies using a fluorescent glucuronide probe showed that significantly greater glucuronide hydrolysis could be achieved in mice pretreated with E. coli (lux/βG) by direct intratumoral injection of the glucuronide probe or by intratumoral lysis of bacteria to release intracellular beta-glucuronidase. Our study suggests that the distribution of beta-glucuronidase, and possibly other therapeutic proteins, in the tumor microenvironment might be an important barrier for effective bacterial-based tumor therapy. Expression of secreted therapeutic proteins or induction of therapeutic protein release from bacteria might therefore be a promising strategy to enhance anti

  6. AGN-2979, an inhibitor of tryptophan hydroxylase activation, does not affect serotonin synthesis in Flinders Sensitive Line rats, a rat model of depression, but produces a significant effect in Flinders Resistant Line rats.

    Science.gov (United States)

    Kanemaru, Kazuya; Nishi, Kyoko; Diksic, Mirko

    2009-12-01

    The neurotransmitter, serotonin, is involved in several brain functions, including both normal, physiological functions, and pathophysiological functions. Alterations in any of the normal parameters of serotonergic neurotransmission can produce several different psychiatric disorders, including major depression. In many instances, brain neurochemical variables are not able to be studied properly in humans, thus making the use of good animal models extremely valuable. One of these animal models is the Flinders Sensitive Line (FSL) of rats, which has face, predictive and constructive validities in relation to human depression. The objective of this study was to quantify the effect of the tryptophan hydroxylase (TPH) activation inhibitor, AGN-2979, on the FSL rats (rats with depression-like behaviour), and compare it to the effect on the Flinders Resistant Line (FRL) of rats used as the control rats. The effect was evaluated by measuring changes in regional serotonin synthesis in the vehicle treated rats (FSL-VEH and FRL-VEH) relative to those measured in the AGN-2979 treated rats (FSL-AGN and FRL-AGN). Regional serotonin synthesis was measured autoradiographically in more than 30 brain regions. The measurements were performed using alpha-[(14)C]methyl-l-tryptophan as the tracer. The results indicate that AGN-2979 did not produce a significant reduction of TPH activity in the AGN-2979 group relative to the vehicle group (a reduction would have been observed if there had been an activation of TPH by the experimental setup) in the FSL rats. On the other hand, there was a highly significant reduction of synthesis in the FRL rats treated by AGN-2979, relative to the vehicle group. Together, the results demonstrate that in the FSL rats, AGN-2979 does not affect serotonin synthesis. This suggests that there was no activation of TPH in the FSL rats during the experimental procedure, but such activation did occur in the FRL rats. Because of this finding, it could be

  7. Using total beta-activity measurements in milk to derive thyroid doses from Chernobyl fallout.

    Science.gov (United States)

    Drozdovitch, V; Germenchuk, M; Bouville, A

    2006-01-01

    Following the Chernobyl accident, more than 200 childhood thyroid cancer cases have been observed in Brest Oblast of Belarus in territories slightly contaminated with 137Cs, but with suspected relatively high 131I fallout. The most helpful measurements available that can be used to estimate thyroid doses for the population of Brest Oblast are the total beta-activity measurements in cow's milk performed using DP-100 device within a few weeks after the accident. The 131I concentrations in milk were derived from the total beta-activity measurements on the basis of (1) a radioecological model used to estimate the variation with time of the radionuclide composition in milk and (2) the determination of the calibration factors of the DP-100 device for the most important radionuclides present in milk. As a result, 131I concentrations in milk were reconstructed for territories with different levels of 137Cs deposition. A non-linear dependence of the 131I concentration in milk on the 137Cs deposition density was obtained; it was used to estimate the thyroid doses from the consumption of 131I-contaminated cow's milk by the population of Brest Oblast. The average individual thyroid doses have been estimated to be 0.15, 0.18, 0.12, 0.06, 0.04 and 0.03 Gy for newborn, children aged 1, 5, 10 and 15 y and adults, respectively. The collective thyroid dose for the entire population of Brest Oblast is estimated to be 64,500 man Gy, the contribution from the adult population being about one half of the total. The methodology that is described could be applied in the framework of epidemiological studies of the relationship between radiation exposure to the thyroid gland and thyroid cancer in areas where numerous total beta-activity measurements in cow's milk were performed within a few weeks after the accident.

  8. Phenylalanine hydroxylase deficiency: diagnosis and management guideline.

    Science.gov (United States)

    Vockley, Jerry; Andersson, Hans C; Antshel, Kevin M; Braverman, Nancy E; Burton, Barbara K; Frazier, Dianne M; Mitchell, John; Smith, Wendy E; Thompson, Barry H; Berry, Susan A

    2014-02-01

    Phenylalanine hydroxylase deficiency, traditionally known as phenylketonuria, results in the accumulation of phenylalanine in the blood of affected individuals and was the first inborn error of metabolism to be identified through population screening. Early identification and treatment prevent the most dramatic clinical sequelae of the disorder, but new neurodevelopmental and psychological problems have emerged in individuals treated from birth. The additional unanticipated recognition of a toxic effect of elevated maternal phenylalanine on fetal development has added to a general call in the field for treatment for life. Two major conferences sponsored by the National Institutes of Health held >10 years apart reviewed the state of knowledge in the field of phenylalanine hydroxylase deficiency, but there are no generally accepted recommendations for therapy. The purpose of this guideline is to review the strength of the medical literature relative to the treatment of phenylalanine hydroxylase deficiency and to develop recommendations for diagnosis and therapy of this disorder. Evidence review from the original National Institutes of Health consensus conference and a recent update by the Agency for Healthcare Research and Quality was used to address key questions in the diagnosis and treatment of phenylalanine hydroxylase deficiency by a working group established by the American College of Medical Genetics and Genomics. The group met by phone and in person over the course of a year to review these reports, develop recommendations, and identify key gaps in our knowledge of this disorder. Above all, treatment of phenylalanine hydroxylase deficiency must be life long, with a goal of maintaining blood phenylalanine in the range of 120-360 µmol/l. Treatment has predominantly been dietary manipulation, and use of low protein and phenylalanine medical foods is likely to remain a major component of therapy for the immediate future. Pharmacotherapy for phenylalanine

  9. Highly Potent, Water Soluble Benzimidazole Antagonist for Activated (alpha)4(beta)1 Integrin

    Energy Technology Data Exchange (ETDEWEB)

    Carpenter, R D; Andrei, M; Lau, E Y; Lightstone, F C; Liu, R; Lam, K S; Kurth, M J

    2007-08-29

    The cell surface receptor {alpha}{sub 4}{beta}{sub 1} integrin, activated constitutively in lymphoma, can be targeted with the bisaryl urea peptidomimetic antagonist 1 (LLP2A). However, concerns on its preliminary pharmacokinetic (PK) profile provided an impetus to change the pharmacophore from a bisaryl urea to a 2-arylaminobenzimidazole moiety resulting in improved solubility while maintaining picomolar potency [5 (KLCA4); IC{sub 50} = 305 pM]. With exceptional solubility, this finding has potential for improving PK to help diagnose and treat lymphomas.

  10. Synergistic activation of vascular TRPC6 channel by receptor and mechanical stimulation via phospholipase C/diacylglycerol and phospholipase A2/¿-hydroxylase/20-HETE pathways

    DEFF Research Database (Denmark)

    Inoue, Ryuji; Jensen, Lars Jørn; Jian, Zhong;

    2009-01-01

    -hydroxylation of arachidonic acid into 20-HETE (20-hydroxyeicosatetraenoic acid). Conversely, direct application of 20-HETE enhanced both OAG-induced macroscopic and single channel TRPC6 currents. Essentially the same results were obtained for TRPC6-like cation channel in A7r5 myocytes, where its activation by noradrenaline...... interactions of receptor and mechanical stimulations in activating this channel using the patch clamp technique. In HEK293 cells expressing TRPC6, application of mechanical stimuli (hypotonicity, shear, 2,4,6-trinitrophenol) caused, albeit not effective by themselves, a prominent potentiation of cationic...... currents (I(TRPC6)) induced by a muscarinic receptor agonist carbachol. This effect was insensitive to a tarantula toxin GsMTx-4 (5 mumol/L). A similar extent of mechanical potentiation was observed after activation of I(TRPC6) by GTPgammaS or a diacylglycerol analog 1-oleoyl-2-acetyl-sn-glycerol (OAG...

  11. Beta-Carotene, Vitamin E, MDA, Glutathione Reductase and Arylesterase Activity Levels in Patients with Active Rheumatoid Arthritis

    Directory of Open Access Journals (Sweden)

    N Aryaeian

    2011-06-01

    Full Text Available "nBackground: Many studies have investigated the possible role of reactive oxygen species in the etiology and patho­gene­sis of Rheumatoid Arthritis (RA. The aim of this study was to investigate the activities of some antioxidants in RA patients."nMethods: In this case-control study, 59 RA patients and 60 healthy sex and age-matched controls were selected. Vitamin E and Beta-carotene were determined using HPLC. Erythrocytes glutathione reductase (GR activity was meas­ured spec­trophotometrically, and malondialdehyde (MDA was determined by colorimetric method. Aryles­terase activity (AEA was measured by Phenylacetate. The clinical data were determined by a rheumatologist, medical history and filling the questionnaire by interview. Statistical analyses were carried out using the SPSS software."nResults: In patients with RA, serum MDA level was significantly higher and plasma concentration of vitamin E, Beta-carotene and GR activity, were significantly lower than healthy control (P<0.001. AEA activity differences between two groups were non-significant."nConclusions: Oxidative stress may play an important role in the inflammation and pathogenesis of RA.  

  12. Characterization of large area ZnS(Ag) detector for gross alpha and beta activity measurements in tap water plants

    Energy Technology Data Exchange (ETDEWEB)

    Lunardon, M.; Cester, D.; Mistura, G.; Moretto, S.; Stevanato, L.; Viesti, G. [Department of Physics and Astronomy ' Galileo Galilei' , University of Padova, (Italy); Schotanus, P.; Bodewits, E. [SCIONIX Holland BV, (Netherlands)

    2015-07-01

    In this work we present the characterization of a large area 200 x 200 mm{sup 2} EJ-444 scintillation detector to be used for monitoring gross alpha and beta activity in tap water plants. Specific tests were performed to determine the best setup to readout the light from the detector side in order to have the possibility to stack many detectors and get a compact device with total active area of the order of 1 m{sup 2}. Alpha/Beta discrimination, efficiency and homogeneity tests were carried out with alpha and beta sources. Background from ambient radioactivity was measured as well. Alpha/beta real-time monitoring in drinking water is a goal of the EU project TAWARA{sub R}TM. (authors)

  13. Simultaneous stimulation of GABA and beta adrenergic receptors stabilizes isotypes of activated adenylyl cyclase heterocomplex

    Directory of Open Access Journals (Sweden)

    Robichon Alain

    2004-06-01

    Full Text Available Abstract Background We investigated how the synthesis of cAMP, stimulated by isoproterenol acting through β-adrenoreceptors and Gs, is strongly amplified by simultaneous incubation with baclofen. Baclofen is an agonist of δ-aminobutyric acid type B receptors [GABAB], known to inhibit adenylyl cyclase via Gi. Because these agents have opposite effects on cAMP levels, the unexpected increase in cAMP synthesis when they are applied simultaneously has been intensively investigated. From previous reports, it appears that cyclase type II contributes most significantly to this phenomenon. Results We found that simultaneous application of isoproterenol and baclofen specifically influences the association/dissociation of molecules involved in the induction and termination of cyclase activity. Beta/gamma from [GABA]B receptor-coupled Gi has a higher affinity for adenylyl cyclase isoform(s when these isoforms are co-associated with Gs. Our data also suggest that, when beta/gamma and Gαs are associated with adenylyl cyclase isoform(s, beta/gamma from [GABA]B receptor-coupled Gi retards the GTPase activity of Gαs from adrenergic receptor. These reciprocal regulations of subunits of the adenylyl cyclase complex might be responsible for the drastic increase of cAMP synthesis in response to the simultaneous signals. Conclusions Simultaneous signals arriving at a particular synapse converge on molecular detectors of coincidence and trigger specific biochemical events. We hypothesize that this phenomenon comes from the complex molecular architectures involved, including scaffolding proteins that make reciprocal interactions between associated molecules possible. The biochemistry of simultaneous signaling is addressed as a key to synaptic function.

  14. Evaluation of beta-naphthoxyacetic acid for mutagenic activity in the Salmonella/mammalian microsome assay.

    Science.gov (United States)

    Rashid, K A; Mumma, R O

    1986-06-01

    Beta-naphthoxyacetic acid (BNOA) is used as a plant growth regulator on tomatoes and strawberries. It is the active ingredient in Blossom-Set and Berry-Set, two plant hormone sprays for fruit-set. The mutagenic activity of BNOA was evaluated in four strains of Salmonella typhimurium (TA97, TA98, TA100 and TA1535) in the presence and absence of liver microsomal and cytosolic enzymes derived from Aroclor induced rats. BNOA did not produce any significant increase (p less than 0.05) in the reversion of any of the four tester strains in the standard plate incorporation assay. Results of the agar overlay toxicity tests indicates that the chemical shows toxic effects at concentrations above 500 micrograms/plate. It was concluded that under the conditions of these tests, BNOA did not exhibit any mutagenic activity.

  15. Interaction of Plasminogen Activator Inhibitor-2 and Proteasome Subunit, Beta Type 1

    Institute of Scientific and Technical Information of China (English)

    JingFAN; Yu-QingZHANG; PingLI; MinHOU; LiTAN; XiaWANG; Yun-SongZHU

    2004-01-01

    The apoptosis protection by plasminogen activator inhibitor-2(PAI-2) is dependent on a 33 amino acid fragment between helix C and D of PAI-2 which is probably due to the interaction of PAI-2 with unknown intracellular proteins. In this study, we used the fragment between helix C and D of PAI-2 as bait to screen a HeLa cell cDNA library constructed during apoptosis in a yeast two-hybrid system and retrieved a clone encoding 241 amino acids of proteasome (prosome, macropain) subunit, beta type 1(PSMβ1) which plays important roles in NF-κB activation. GST-pulldown experiments confirmed the interaction between PAI-2 and PSMβ1 in vitro. These data suggest that the antiapoptosis activity of PAI-2 is probably related to its interation with PSMβ1.

  16. Histochemical demonstration of activity of acid phosphatase and beta-glucuronidase in bovine incisor tooth germs

    DEFF Research Database (Denmark)

    Kirkeby, S; Salling, E; Moe, D

    1983-01-01

    Activity of acid phosphatase and beta-glucuronidase was shown in bovine preodontoblasts and preameloblasts prior to the onset of secretion. In the preameloblasts the rather weak reaction consisted of small discrete granules dispersed in the cytoplasm apical, lateral, and proximal to the nucleus....... After initiation of enamel formation, a change in localization and intensity of the colored reaction product was observed in the ameloblasts. The activity appeared stronger and was restricted to a narrow zone just apical to the nucleus. It is proposed that the acid hydrolases in the tooth forming cells...... are located to the Golgi complex. The differences in activity of acid hydrolases between bone and tooth forming cells are expounded....

  17. Early peroxisome proliferator-activated receptor gamma regulated genes involved in expansion of pancreatic beta cell mass

    Directory of Open Access Journals (Sweden)

    Vivas Yurena

    2011-12-01

    Full Text Available Abstract Background The progression towards type 2 diabetes depends on the allostatic response of pancreatic beta cells to synthesise and secrete enough insulin to compensate for insulin resistance. The endocrine pancreas is a plastic tissue able to expand or regress in response to the requirements imposed by physiological and pathophysiological states associated to insulin resistance such as pregnancy, obesity or ageing, but the mechanisms mediating beta cell mass expansion in these scenarios are not well defined. We have recently shown that ob/ob mice with genetic ablation of PPARγ2, a mouse model known as the POKO mouse failed to expand its beta cell mass. This phenotype contrasted with the appropriate expansion of the beta cell mass observed in their obese littermate ob/ob mice. Thus, comparison of these models islets particularly at early ages could provide some new insights on early PPARγ dependent transcriptional responses involved in the process of beta cell mass expansion Results Here we have investigated PPARγ dependent transcriptional responses occurring during the early stages of beta cell adaptation to insulin resistance in wild type, ob/ob, PPARγ2 KO and POKO mice. We have identified genes known to regulate both the rate of proliferation and the survival signals of beta cells. Moreover we have also identified new pathways induced in ob/ob islets that remained unchanged in POKO islets, suggesting an important role for PPARγ in maintenance/activation of mechanisms essential for the continued function of the beta cell. Conclusions Our data suggest that the expansion of beta cell mass observed in ob/ob islets is associated with the activation of an immune response that fails to occur in POKO islets. We have also indentified other PPARγ dependent differentially regulated pathways including cholesterol biosynthesis, apoptosis through TGF-β signaling and decreased oxidative phosphorylation.

  18. Antimicrobial activity of beta-lactams against multiresistant micro-organisms from the family Enterobacteriaceae, and genus Pseudomonas.

    Science.gov (United States)

    Niebla, A; González, I; Vallín, C

    1994-01-01

    The antimicrobial activity of twenty beta-lactams was determined against multiresistant micro-organisms from the Enterobacteriaceae family (450) and the genus Pseudomonas (90). The antimicrobial susceptibility was assessed by the disk diffusion method. The most effective antibiotics were cephalosporins of the second and third generation, and non-classical beta-lactams (imipenem and moxalactam). A pronounced resistance was found to carbenicillin, ampicillin, cephalotin and cefazolin. These resistance patterns corresponded to a high consumption of these antibiotics.

  19. 17-Beta-estradiol inhibits transforming growth factor-beta signaling and function in breast cancer cells via activation of extracellular signal-regulated kinase through the G protein-coupled receptor 30.

    Science.gov (United States)

    Kleuser, Burkhard; Malek, Daniela; Gust, Ronald; Pertz, Heinz H; Potteck, Henrik

    2008-12-01

    Breast cancer development and breast cancer progression involves the deregulation of growth factors leading to uncontrolled cellular proliferation, invasion and metastasis. Transforming growth factor (TGF)-beta plays a crucial role in breast cancer because it has the potential to act as either a tumor suppressor or a pro-oncogenic chemokine. A cross-communication between the TGF-beta signaling network and estrogens has been postulated, which is important for breast tumorigenesis. Here, we provide evidence that inhibition of TGF-beta signaling is associated with a rapid estrogen-dependent nongenomic action. Moreover, we were able to demonstrate that estrogens disrupt the TGF-beta signaling network as well as TGF-beta functions in breast cancer cells via the G protein-coupled receptor 30 (GPR30). Silencing of GPR30 in MCF-7 cells completely reduced the ability of 17-beta-estradiol (E2) to inhibit the TGF-beta pathway. Likewise, in GPR30-deficient MDA-MB-231 breast cancer cells, E2 achieved the ability to suppress TGF-beta signaling only after transfection with GPR30-encoding plasmids. It is most interesting that the antiestrogen fulvestrant (ICI 182,780), which possesses agonistic activity at the GPR30, also diminished TGF-beta signaling. Further experiments attempted to characterize the molecular mechanism by which activated GPR30 inhibits the TGF-beta pathway. Our results indicate that GPR30 induces the stimulation of the mitogen-activated protein kinases (MAPKs), which interferes with the activation of Smad proteins. Inhibition of MAPK activity prevented the ability of E2 from suppressing TGF-beta signaling. These findings are of great clinical relevance, because down-regulation of TGF-beta signaling is associated with the development of breast cancer resistance in response to antiestrogens.

  20. Proteolytically modified human beta 2-microglobulin augments the specific cytotoxic activity in murine mixed lymphocyte culture

    DEFF Research Database (Denmark)

    Nissen, Mogens Holst; Claësson, M H

    1987-01-01

    (M-beta 2-m) bind to murine lymphocytes expressing H-2 class I antigens; M-beta 2-m, when added at day 0 and 1 of culture in nanomolar concentrations to a one-way murine allogeneic mixed lymphocyte culture (MLC) augments the generation of specific cytotoxic T lymphocytes; M-beta 2-m increases...... the endogenous production of interleukin 2 in the MLC culture; monoclonal antibody which reacts with both the native beta 2-m and M-beta 2-m molecule blocks the augmentation of cytotoxic T lymphocyte production induced by M-beta 2-m; murine as well as human MLC responder cells can proteolytically modify native...

  1. Activation of the Nlrp3 inflammasome in infiltrating macrophages by endocannabinoids mediates beta cell loss in type 2 diabetes.

    Science.gov (United States)

    Jourdan, Tony; Godlewski, Grzegorz; Cinar, Resat; Bertola, Adeline; Szanda, Gergő; Liu, Jie; Tam, Joseph; Han, Tiffany; Mukhopadhyay, Bani; Skarulis, Monica C; Ju, Cynthia; Aouadi, Myriam; Czech, Michael P; Kunos, George

    2013-09-01

    Type 2 diabetes mellitus (T2DM) progresses from compensated insulin resistance to beta cell failure resulting in uncompensated hyperglycemia, a process replicated in the Zucker diabetic fatty (ZDF) rat. The Nlrp3 inflammasome has been implicated in obesity-induced insulin resistance and beta cell failure. Endocannabinoids contribute to insulin resistance through activation of peripheral CB1 receptors (CB₁Rs) and also promote beta cell failure. Here we show that beta cell failure in adult ZDF rats is not associated with CB₁R signaling in beta cells, but rather in M1 macrophages infiltrating into pancreatic islets, and that this leads to activation of the Nlrp3-ASC inflammasome in the macrophages. These effects are replicated in vitro by incubating wild-type human or rodent macrophages, but not macrophages from CB₁R-deficient (Cnr1(-/-)) or Nlrp3(-/-) mice, with the endocannabinoid anandamide. Peripheral CB₁R blockade, in vivo depletion of macrophages or macrophage-specific knockdown of CB₁R reverses or prevents these changes and restores normoglycemia and glucose-induced insulin secretion. These findings implicate endocannabinoids and inflammasome activation in beta cell failure and identify macrophage-expressed CB₁R as a therapeutic target in T2DM.

  2. Beta activity in the premotor cortex is increased during stabilized as compared to normal walking

    Directory of Open Access Journals (Sweden)

    Sjoerd M. Bruijn

    2015-10-01

    Full Text Available Walking on two legs is inherently unstable. Still, we humans perform remarkable well at it, mostly without falling. To gain more understanding of the role of the brain in controlling gait stability we measured brain activity using electro-encephalography (EEG during stabilized and normal walking.Subjects walked on a treadmill in two conditions, each lasting 10 minutes; normal, and while being laterally stabilized by elastic cords. Kinematics of trunk and feet, electro-myography (EMG of neck muscles, as well as 64-channel EEG were recorded. To assess gait stability the local divergence exponent, step width, and trunk range of motion were calculated from the kinematic data. We used independent component analysis to remove movement, EMG, and eyeblink artifacts from the EEG, after which dynamic imaging of coherent sources beamformers were determined to identify cortical sources that showed a significant difference between conditions. Stabilized walking led to a significant increase in gait stability, i.e. lower local divergence exponents. Beamforming analysis of the beta band activity revealed significant sources in bilateral pre-motor cortices. Projection of sensor data on these sources showed a significant difference only in the left premotor area, with higher beta power during stabilized walking, specifically around push-off, although only significant around contralateral push-off. It appears that even during steady gait the cortex is involved in the control of stability.

  3. The TF1-ATPase and ATPase activities of assembled alpha 3 beta 3 gamma, alpha 3 beta 3 gamma delta, and alpha 3 beta 3 gamma epsilon complexes are stimulated by low and inhibited by high concentrations of rhodamine 6G whereas the dye only inhibits the alpha 3 beta 3, and alpha 3 beta 3 delta complexes.

    Science.gov (United States)

    Paik, S R; Yokoyama, K; Yoshida, M; Ohta, T; Kagawa, Y; Allison, W S

    1993-12-01

    The ATPase activity of the F1-ATPase from the thermophilic bacterium PS3 is stimulated at concentrations of rhodamine 6G up to about 10 microM where 70% stimulation is observed at 36 degrees C. Half maximal stimulation is observed at about 3 microM dye. At rhodamine 6G concentrations greater than 10 microM, ATPase activity declines with 50% inhibition observed at about 75 microM dye. The ATPase activities of the alpha 3 beta 3 gamma and alpha 3 beta 3 gamma delta complexes assembled from isolated subunits of TF1 expressed in E. coli deleted of the unc operon respond to increasing concentrations of rhodamine 6G nearly identically to the response of TF1. In contrast, the ATPase activities of the alpha 3 beta 3 and alpha 3 beta 3 delta complexes are only inhibited by rhodamine 6G with 50% inhibition observed, respectively, at 35 and 75 microM dye at 36 degrees C. The ATPase activity of TF1 is stimulated up to 4-fold by the neutral detergent, LDAO. In the presence of stimulating concentrations of LDAO, the ATPase activity of TF1 is no longer stimulated by rhodamine 6G, but rather, it is inhibited with 50% inhibition observed at about 30 microM dye at 30 degrees C. One interpretation of these results is that binding of rhodamine 6G to a high-affinity site on TF1 stimulates ATPase activity and unmasks a low-affinity, inhibitory site for the dye which is also exposed by LDAO.

  4. The Effect of the Arg389Gly Beta-1 Adrenoceptor Polymorphism on Plasma Renin Activity and Heart Rate and the Genotype-Dependent Response to Metoprolol Treatment

    DEFF Research Database (Denmark)

    Petersen, Morten; Andersen, Jon T; Jimenez-Solem, Espen

    2012-01-01

    A gene-drug interaction has been indicated between beta-1 selective beta-blockers and the Arg389Gly polymorphism (rs1801253) in the adrenergic beta-1 receptor gene (ADRB1). We studied the effect of the ADRB1 Arg389Gly polymorphism on plasma renin activity (PRA) and heart rate (HR) and the genotype...

  5. Beta-D-xylosidase from Selenomonas ruminantium: Role of Glutamate 186 in Catalysis Revealed by Site-Directed Mutagenesis, Alternate Substrates, and Active-site Inhibitor

    Science.gov (United States)

    Beta-D-xylosidase/alpha-L-arabinofuranosidase from Selenomonas ruminantium (SXA) is the most active enzyme known for catalyzing hydrolysis of 1,4-beta-D-xylooligosaccharides to D xylose. Catalysis and inhibitor binding by the GH43 beta-xylosidase are governed by the protonation states of catalytic ...

  6. Glucan, water dikinase activity stimulates breakdown of starch granules by plastidial beta-amylases.

    Science.gov (United States)

    Edner, Christoph; Li, Jing; Albrecht, Tanja; Mahlow, Sebastian; Hejazi, Mahdi; Hussain, Hasnain; Kaplan, Fatma; Guy, Charles; Smith, Steven M; Steup, Martin; Ritte, Gerhard

    2007-09-01

    Glucan phosphorylating enzymes are required for normal mobilization of starch in leaves of Arabidopsis (Arabidopsis thaliana) and potato (Solanum tuberosum), but mechanisms underlying this dependency are unknown. Using two different activity assays, we aimed to identify starch degrading enzymes from Arabidopsis, whose activity is affected by glucan phosphorylation. Breakdown of granular starch by a protein fraction purified from leaf extracts increased approximately 2-fold if the granules were simultaneously phosphorylated by recombinant potato glucan, water dikinase (GWD). Using matrix-assisted laser-desorption ionization mass spectrometry several putative starch-related enzymes were identified in this fraction, among them beta-AMYLASE1 (BAM1; At3g23920) and ISOAMYLASE3 (ISA3; At4g09020). Experiments using purified recombinant enzymes showed that BAM1 activity with granules similarly increased under conditions of simultaneous starch phosphorylation. Purified recombinant potato ISA3 (StISA3) did not attack the granular starch significantly with or without glucan phosphorylation. However, starch breakdown by a mixture of BAM1 and StISA3 was 2 times higher than that by BAM1 alone and was further enhanced in the presence of GWD and ATP. Similar to BAM1, maltose release from granular starch by purified recombinant BAM3 (At4g17090), another plastid-localized beta-amylase isoform, increased 2- to 3-fold if the granules were simultaneously phosphorylated by GWD. BAM activity in turn strongly stimulated the GWD-catalyzed phosphorylation. The interdependence between the activities of GWD and BAMs offers an explanation for the severe starch excess phenotype of GWD-deficient mutants.

  7. Detection and characterization of p-coumaric acid hydroxylase in mung bean, Vigna mungo, seedlings.

    Science.gov (United States)

    Kojima, M; Takeuchi, W

    1989-02-01

    A new p-coumaric acid (4-hydroxycinnamic acid) hydroxylase was detected in mung bean seedlings treated with tentoxin, a fungal toxin, in which polyphenol oxidase that hydroxylates a wide variety of monophenols in vitro was completely eliminated. The enzyme required molecular oxygen and showed a pH optimum of 5.0. The enzyme acted only on p-coumaric acid (Km, 3.0 X 10(-5) M), while its specificity for the electron donor was rather broad. The Km value for NADPH (1.5 X 10(-4) M) was much lower than that for L-ascorbic acid (1.0 X 10(-2) M), although the Vmax value was almost the same with both electron donors. The enzyme was potently inhibited by beta-mercaptoethanol (Ki, 3.5 X 10(-6) M) and diethyldithiocarbamate (Ki, 2.3 X 10(-4) M), but was insensitive to p-chloromercuribenzoate. The enzyme was localized in the cell organelles which sedimented between mitochondria and endplasmic reticulum on sucrose density gradient centrifugation. The enzyme activity in the seedling was changed in response to induction by light in a manner suggesting its involvement in biosynthesis of phenolic compounds in mung bean seedlings.

  8. OROFASYAL ENFEKSİYONLARDA BETA-LAKTAMAZ AKTİVİTESİ-ACTIVITY OF BETA-LACTAMASE IN OROFACIAL INFECTIONS

    OpenAIRE

    Gümrü, Osman Z.; Külekçi, Güven; Kasapoğlu, Çetin; Koçak, Hülya

    2013-01-01

    ÖZETAntibiyotiklere direnç mekanizmasının en önemlisi beta-laktamaz ile olanıdır.Çalışma, kliniğe alt 20 yaş dişlerinin cerrahi çekimlerinden sonra görülen post-operatif enfeksiyonlar, alt çene osteomyetiti, iltihabı radîküler kist, periapikal ve perio-dontal abse gibi orofasyal enfeksiyonlar nedeniyle başvuran toplam 33 hasta üzerinde yapıldı.Materyal ponksiyon yapılarak alındı ve hemen mikrobiyoloji laborahıvanna götürüldü.Yapılan mikrobiyolojik incelemede izole edilen 36 sustan 12'inde (% ...

  9. Activation of transmembrane bile acid receptor TGR5 stimulates insulin secretion in pancreatic {beta} cells

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, Divya P.; Rajagopal, Senthilkumar; Mahavadi, Sunila [Department of Physiology and Biophysics, Virginia Commonwealth University School of Medicine, Richmond, VA (United States); Mirshahi, Faridoddin [Division of Gastroenterology, Hepatology and Nutrition, Department of Internal Medicine, Virginia Commonwealth University School of Medicine, Richmond, VA (United States); Grider, John R. [Department of Physiology and Biophysics, Virginia Commonwealth University School of Medicine, Richmond, VA (United States); Murthy, Karnam S., E-mail: skarnam@vcu.edu [Department of Physiology and Biophysics, Virginia Commonwealth University School of Medicine, Richmond, VA (United States); Sanyal, Arun J., E-mail: asanyal@mcvh-vcu.edu [Division of Gastroenterology, Hepatology and Nutrition, Department of Internal Medicine, Virginia Commonwealth University School of Medicine, Richmond, VA (United States)

    2012-10-26

    Highlights: Black-Right-Pointing-Pointer G protein coupled receptor TGR5 is expressed in mouse and human islets. Black-Right-Pointing-Pointer TGR5 is coupled to activation of Gs and Ca{sup 2+} release via cAMP/Epac/PLC-{epsilon} pathway. Black-Right-Pointing-Pointer Activation of TGR5 by bile salts and selective ligands causes insulin secretion. Black-Right-Pointing-Pointer TGR5 could be a potential therapeutic target to treat diabetes. -- Abstract: Bile acids act as signaling molecules and stimulate the G protein coupled receptor, TGR5, in addition to nuclear farnesoid X receptor to regulate lipid, glucose and energy metabolism. Bile acid induced activation of TGR5 in the enteroendocrine cells promotes glucagon like peptide-1 (GLP-1) release, which has insulinotropic effect in the pancreatic {beta} cells. In the present study, we have identified the expression of TGR5 in pancreatic {beta} cell line MIN6 and also in mouse and human pancreatic islets. TGR5 selective ligands, oleanolic acid (OA) and INT-777 selectively activated G{alpha}{sub s} and caused an increase in intracellular cAMP and Ca{sup 2+}. OA and INT-777 also increased phosphoinositide (PI) hydrolysis and the increase was blocked by NF449 (a selective G{alpha}{sub s} inhibitor) or (U73122) (PI hydrolysis inhibitor). OA, INT-777 and lithocholic acid increased insulin release in MIN6 and human islets and the increase was inhibited by treatment with NF449, (U73122) or BAPTA-AM (chelator of calcium), but not with myristoylated PKI (PKA inhibitor), suggesting that the release is dependent on G{sub s}/cAMP/Ca{sup 2+} pathway. 8-pCPT-2 Prime -O-Me-cAMP, a cAMP analog, which activates Epac, but not PKA also stimulated PI hydrolysis. In conclusion, our study demonstrates that the TGR5 expressed in the pancreatic {beta} cells regulates insulin secretion and highlights the importance of ongoing therapeutic strategies targeting TGR5 in the control of glucose homeostasis.

  10. Synthesis and structure-activity study of quaternary ammonium functionalized beta-cyclodextrin-carboxymethylcellulose polymers.

    Science.gov (United States)

    Bonenfant, Danielle; Bourgeois, François-René; Mimeault, Murielle; Monette, Frédéric; Niquette, Patrick; Hausler, Robert

    2011-01-01

    Carboxymethylcellulose (CMC) and beta-cyclodextrin (beta-CD)-based polymers functionalized with two types of quaternary ammonium compounds (QACs), the alkaquat DMB-451 (N-alkyl (50% C14, 40% C12, 10% C10) dimethylbenzylammonium chloride) (DMD-451) named polymer DMB-451, and FMB 1210-8 (a blend of 32 w% N-alkyl (50% C14, 40% C12, 10% C10) dimethylbenzylammonium chloride and 48 w% of didecyldimethylammonium chloride) named polymer FMB 1210-8, were synthethized and characterized by Fourier transform infrared spectroscopy. The antimicrobial activities of these polymers against Eschericia coli were also evaluated at 25 degrees C in wastewater. The results have indicated that the polymer FMB 1210-8 possesses a high-affinity binding with bacterial cells that induces a rapid disinfection process. Moreover, in the same experimental conditions of disinfection (mixture of 1.0 g of polymer and 100 mL of wastewater), the polymer FMB 1210-8 has a higher antimicrobial efficiency (99.90%) than polymer DMB-451 (92.8%). This phenomenon might be associated to a stronger interaction with bacterial cells due to stronger binding affinity for E. coli cells and greater killing efficiency of the C10 alkyl chains QAC of polymer FMB 1210-8 to disrupt the bacterial cell membrane as compared to N-alkyl (50% C14, 40% C12, 10% C10) dimethylbenzylammonium chloride. Together, these results suggest that the polymer FMB 1210-8 could constitute a good disinfectant against Escherichia coli, which could be advantageously used in wastewater treatments due to the low toxicity of beta-CD and CMC, and moderated toxicity of FMB 1210-8 to human and environment.

  11. Cinnamic acid 4-hydroxylase of sorghum [Sorghum biocolor (L.) Moench] gene SbC4H1 restricts lignin synthesis in Arabidopsis

    Science.gov (United States)

    Cinnamic acid 4-hydroxylase (C4H) is the first hydroxylase enzyme of the phenylpropanoid pathway, and its content and activity affects the lignin synthesis. In this study, we isolated a C4H gene SbC4H1 from the suppression subtractive hybridization library of brown midrib (bmr) mutants of Sorghum b...

  12. Effect of interleukin-1beta gene functional polymorphism on dorsolateral prefrontal cortex activity in schizophrenic patients.

    Science.gov (United States)

    Papiol, Sergi; Molina, Vicente; Rosa, Araceli; Sanz, Javier; Palomo, Tomás; Fañanás, Lourdes

    2007-12-05

    Hypoactivity of the dorsolateral prefrontal cortex (DLPFC) during cognitive tasks is among the most consistent findings in schizophrenia. The biological factors contributing to this hypofrontality are only partially known. Previous reports have shown the influence of genes mapped to IL-1 cluster (i) in the risk to develop schizophrenia and (ii) on brain morphological abnormalities in these patients. Moreover, Interleukin-1beta (IL-1beta), encoded by IL-1B gene (IL-1 cluster, chromosome 2q13) has a key role in dopaminergic differentiation and dendrite growth in developing cortical neurons. The authors explored the role of a genetic functional polymorphism at IL-1B gene in relation to DLPFC activity. DLPFC (left and right) metabolic activity was measured in a sample of 19 DSM-IV diagnosed schizophrenic patients of Spanish origin using a procedure based on MRI/PET image fusion. During PET studies, subjects performed a contingent Continuous Performance Test aiming to activate DLPFC. Functional promoter polymorphism -511 C/T (rs16944) of IL-1B gene was genotyped in these patients. Those patients who were allele 2 (-511 T) carriers showed a lower metabolic activity in the left DLPFC with respect to patients homozygous for allele 1 (-511 C) (U = 16, z = -2.32, P = 0.02). Our results suggest that hypofrontality reported in some schizophrenic patients might be explained, at least in part, by this functional polymorphism at IL-1B gene. Genetic variants with influence on brain functionality may account for the neurocognitive heterogeneity observed in schizophrenic patients.

  13. Dynamic regulation of phenylalanine hydroxylase by simulated redox manipulation.

    Directory of Open Access Journals (Sweden)

    Julian E Fuchs

    Full Text Available Recent clinical studies revealed increased phenylalanine levels and phenylalanine to tyrosine ratios in patients suffering from infection, inflammation and general immune activity. These data implicated down-regulation of activity of phenylalanine hydroxylase by oxidative stress upon in vivo immune activation. Though the structural damage of oxidative stress is expected to be comparably small, a structural rationale for this experimental finding was lacking. Hence, we investigated the impact of side chain oxidation at two vicinal cysteine residues on local conformational flexibility in the protein by comparative molecular dynamics simulations. Analysis of backbone dynamics revealed a highly flexible loop region (Tyr138-loop in proximity to the active center of phenylalanine hydroxylase. We observed elevated loop dynamics in connection with a loop movement towards the active site in the oxidized state, thereby partially blocking access for the substrate phenylalanine. These findings were confirmed by extensive replica exchange molecular dynamics simulations and serve as a first structural explanation for decreased enzyme turnover in situations of oxidative stress.

  14. Dynamic regulation of phenylalanine hydroxylase by simulated redox manipulation.

    Science.gov (United States)

    Fuchs, Julian E; Huber, Roland G; von Grafenstein, Susanne; Wallnoefer, Hannes G; Spitzer, Gudrun M; Fuchs, Dietmar; Liedl, Klaus R

    2012-01-01

    Recent clinical studies revealed increased phenylalanine levels and phenylalanine to tyrosine ratios in patients suffering from infection, inflammation and general immune activity. These data implicated down-regulation of activity of phenylalanine hydroxylase by oxidative stress upon in vivo immune activation. Though the structural damage of oxidative stress is expected to be comparably small, a structural rationale for this experimental finding was lacking. Hence, we investigated the impact of side chain oxidation at two vicinal cysteine residues on local conformational flexibility in the protein by comparative molecular dynamics simulations. Analysis of backbone dynamics revealed a highly flexible loop region (Tyr138-loop) in proximity to the active center of phenylalanine hydroxylase. We observed elevated loop dynamics in connection with a loop movement towards the active site in the oxidized state, thereby partially blocking access for the substrate phenylalanine. These findings were confirmed by extensive replica exchange molecular dynamics simulations and serve as a first structural explanation for decreased enzyme turnover in situations of oxidative stress.

  15. Modifications of the alpha,beta-double bond in chalcones only marginally affect the antiprotozoal activities

    DEFF Research Database (Denmark)

    Nielsen, S F; Kharazmi, A; Christensen, S B

    1998-01-01

    Methods for selective alkylation of chalcones in the alpha- or beta-position and for selective reduction of the alpha,beta-double bond have been developed. The antiparasitic potencies of the alpha,beta-double bond modified chalcones only differ marginally from the potencies of the parent chalcones...

  16. The period between beta-blocker use and physical activity changes training heart rate behavior

    Directory of Open Access Journals (Sweden)

    Naiane Ferraz Bandeira Alves

    2009-12-01

    Full Text Available The Brazilian Society of Cardiology (SBC proposes that hypertensive subjects who use beta-blockers and practice physical exercises must have their training heart rate (HR corrected due to the negative chronotropic effect of this drug. Nevertheless, if the physical activity is performed outside of plasmatic half-life, correction may not be necessary. This study investigated the exercise chronotropic response both inside and outside the beta-blocker plasmatic half-life. Nine subjects in use of atenolol or propranolol, and six controls, carried out three walking sessions in three days according to different schedules: EX2 (two hours after drug administration, at the plasmatic peak; EX11 (eleven hours after drug administration, at the end of plasmatic half-life; and EX23 (twenty-three hours after drug administration, outside the plasmatic half-life. The walking sessions were performed on an ergometric treadmill and HR was monitored by a heart rate monitor. During the exercises, mean HRs were 97.2, 108.4 and 109 for EX2, EX11 and EX23, respectively, with the value for EX2 statistically lower than the others (p0.05. The study concludes that the attenuation of the positive chronotropic response which occurs during exercise in subjects using beta-blockers, is less evident when the exercise is performed outside the plasmatic half-life of the drug.A Sociedade Brasileira de Cardiologia (SBC propõe que os hipertensos que utilizam beta-bloqueadores e praticam exercícios físicos devem ter sua frequência cardíaca de treinamento (HR corrigida devido ao efeito cronotrópico negativo desse fármaco. Contudo, se a atividade física é realizada fora da meia-vida plasmática do fármaco, a correção pode não ser necessária. Este estudo investigou a resposta cronotrópica ao exercício dentro e fora da meia-vida plasmática do beta-bloqueador. Nove indivíduos que usavam atenolol ou propranolol e seis controles, efetuaram três sessões de caminhada em tr

  17. Few active mechanisms of the neutrinoless double beta-decay and effective mass of Majorana neutrinos

    CERN Document Server

    Simkovic, Fedor; Faessler, Amand

    2010-01-01

    It is well known that there exist many mechanisms that may contribute to neutrinoless double beta decay (0nbb-decay). By exploiting the fact that the associated nuclear matrix elements are target dependent we show that, given definite experimental results on a sufficient number of targets, one can determine or sufficiently constrain all lepton violating parameters including the mass term. As a specific example we show that, assuming the observation of the 0nbb-decay in three different nuclei, e.g., 76Ge, 100Mo and 130Te, and just three lepton number violating mechanisms (light and heavy neutrino mass mechanisms as well as R-parity breaking SUSY mechanism) being active, there are only four different solutions for the lepton violating parameters, provided that they are relatively real. In particular, assuming evidence of the 0nbb-decay of 76Ge, the effective neutrino Majorana mass |m_bb| can be almost uniquely extracted by utilizing other existing constraints (cosmological observations and tritium beta-decay ex...

  18. Temporal expectation and attention jointly modulate auditory oscillatory activity in the beta band.

    Science.gov (United States)

    Todorovic, Ana; Schoffelen, Jan-Mathijs; van Ede, Freek; Maris, Eric; de Lange, Floris P

    2015-01-01

    The neural response to a stimulus is influenced by endogenous factors such as expectation and attention. Current research suggests that expectation and attention exert their effects in opposite directions, where expectation decreases neural activity in sensory areas, while attention increases it. However, expectation and attention are usually studied either in isolation or confounded with each other. A recent study suggests that expectation and attention may act jointly on sensory processing, by increasing the neural response to expected events when they are attended, but decreasing it when they are unattended. Here we test this hypothesis in an auditory temporal cueing paradigm using magnetoencephalography in humans. In our study participants attended to, or away from, tones that could arrive at expected or unexpected moments. We found a decrease in auditory beta band synchrony to expected (versus unexpected) tones if they were unattended, but no difference if they were attended. Modulations in beta power were already evident prior to the expected onset times of the tones. These findings suggest that expectation and attention jointly modulate sensory processing.

  19. [Activity of cefpodoxime and other oral beta-lactams against Haemophilus influenzae and Streptococcus pneumoniae with different susceptibilities to penicillin].

    Science.gov (United States)

    Fenoll, A; Robledo, O; Lerma, M; Giménez, M J; Cebrián, L; Casal, J; Aguilar, L; Gómez-Lus, M L

    2006-03-01

    This study explores the influence on the intrinsic activity of different oral beta-lactams of beta-lactamase production in Haemophilus influenzae and penicillin resistance in Streptococcus pneumoniae. Three substudies were performed: a) a general susceptibility study, analyzing 550 strains received by the Spanish Laboratorio de Referencia de Neumococos throughout February and March 2005; b) a study on the influence of penicillin resistance on the activity of beta-lactams, analyzing 251 penicillin-susceptible strains (MICor=2 mg/l) randomly chosen among those received by the Spanish Laboratorio de Referencia de Neumococos throughout 2005; and c) an H. influenzae susceptibility study analyzing 150 strains received by Instituto Valenciano de Microbiologia throughout 2005. A total of 71% of S. pneumoniae strains were susceptible to penicillin, 21% exhibited intermediate resistance and 8% strains presented full resistance. H. influenzae beta-lactamase production rate was 18.6%. Of the non-beta-lactamase-producing strains, 3% were not susceptible to ampicillin. Cefpodoxime and cefixime exhibited the highest intrinsic activity against H. influenzae, while amoxicillin and cefpodoxime were the most active compounds against S. pneumoniae. All H. influenzae strains were susceptible to oral cephalosporins and amoxicillin/clavulanic acid. The increase in penicillin resistance in S. pneumoniae influenced cefixime, cefaclor and cefuroxime to a higher degree than amoxicillin and cefpodoxime.

  20. Cloning and expression of Chromobacterium violaceum phenylalanine hydroxylase in Escherichia coli and comparison of amino acid sequence with mammalian aromatic amino acid hydroxylases.

    Science.gov (United States)

    Onishi, A; Liotta, L J; Benkovic, S J

    1991-10-05

    The complete amino acid sequence (296 amino acids) of Chromobacterium violaceum phenylalanine hydroxylase (PAH) was determined by nucleotide analysis of a DNA clone isolated using both a synthetic oligonucleotide probe based on the NH2-terminal amino acid sequence and an antibody against this enzyme. The ApaL I fragment (approximately 1.9 kilobase pairs) containing the entire PAH gene was subcloned in pBluescript II and induced by isopropyl-beta-D-thiogalactopyranoside. In order to eliminate fusion proteins the XbaI/ClaI fragment which contained the PAH gene from the Bluescript construct was subcloned into pMAC 5-8 containing the TAC promoter. The recombinant protein reacts with antibody raised to authentic C. violaceum PAH and its NH2-terminal 20-amino acid sequence and COOH-terminal amino acid residue were identical with the wild-type protein. Key physical and chemical characteristics of the recombinant protein, i.e. its copper content and Michaelis-Menten parameters, were the same as wild-type. Comparison of amino acid sequences revealed a highly conserved region between C. violaceum PAH and three different mammalian aromatic amino acid hydroxylases. This conserved area may well be a catalytically important domain of these pterin- and metal-requiring aromatic amino acid hydroxylases. The over-expression of C. violaceum PAH in Escherichia coli will facilitate the analysis of the enzyme mechanism by various spectroscopic methods.

  1. Phenylalanine hydroxylase misfolding and pharmacological chaperones.

    Science.gov (United States)

    Underhaug, Jarl; Aubi, Oscar; Martinez, Aurora

    2012-01-01

    Phenylketonuria (PKU) is a loss-of-function inborn error of metabolism. As many other inherited diseases the main pathologic mechanism in PKU is an enhanced tendency of the mutant phenylalanine hydroxylase (PAH) to misfold and undergo ubiquitin-dependent degradation. Recent alternative approaches with therapeutic potential for PKU aim at correcting the PAH misfolding, and in this respect pharmacological chaperones are the focus of increasing interest. These compounds, which often resemble the natural ligands and show mild competitive inhibition, can rescue the misfolded proteins by stimulating their renaturation in vivo. For PKU, a few studies have proven the stabilization of PKU-mutants in vitro, in cells, and in mice by pharmacological chaperones, which have been found either by using the tetrahydrobiopterin (BH(4)) cofactor as query structure for shape-focused virtual screening or by high-throughput screening of small compound libraries. Both approaches have revealed a number of compounds, most of which bind at the iron-binding site, competitively with respect to BH(4). Furthermore, PAH shares a number of ligands, such as BH(4), amino acid substrates and inhibitors, with the other aromatic amino acid hydroxylases: the neuronal/neuroendocrine enzymes tyrosine hydroxylase (TH) and the tryptophan hydroxylases (TPHs). Recent results indicate that the PAH-targeted pharmacological chaperones should also be tested on TH and the TPHs, and eventually be derivatized to avoid unwanted interactions with these other enzymes. After derivatization and validation in animal models, the PAH-chaperoning compounds represent novel possibilities in the treatment of PKU.

  2. Alpha- and Beta-Cyclodextrin Inclusion Complexes with 5-Fluorouracil: Characterization and Cytotoxic Activity Evaluation

    Directory of Open Access Journals (Sweden)

    Cristina Di Donato

    2016-12-01

    Full Text Available Cyclodextrins are natural macrocyclic oligosaccharides able to form inclusion complexes with a wide variety of guests, affecting their physicochemical and pharmaceutical properties. In order to obtain an improvement of the bioavailability and solubility of 5-fluorouracil, a pyrimidine analogue used as chemotherapeutic agent in the treatment of the colon, liver, and stomac cancers, the drug was complexed with alpha- and beta-cyclodextrin. The inclusion complexes were prepared in the solid state by kneading method and characterized by Fourier transform-infrared (FT-IR spectroscopy and X-ray powder diffractometry. In solution, the 1:1 stoichiometry for all the inclusion complexes was established by the Job plot method and the binding constants were determined at different pHs by UV-VIS titration. Furthermore, the cytotoxic activity of 5-fluorouracil and its complexation products were evaluated using the 3-(4,5-dimethylthiazol-2-yl-2,5-diphenyltetrazolium bromide (MTT assay on MCF-7 (breast cancer cell line, Hep G2 (hepatocyte carcinoma cell line, Caco-2 (colon adenocarcinoma cell line, and A-549 (alveolar basal epithelial carcinoma cell line. The results showed that both inclusion complexes increased the 5-fluorouracil capability of inhibiting cell growth. In particular, 5-fluorouracil complexed with beta-cyclodextrin had the highest cytotoxic activity on MCF-7; with alpha-cyclodextrin the highest cytotoxic activity was observed on A-549. The IC50 values were equal to 31 and 73 µM at 72 h, respectively. Our results underline the possibility of using these inclusion complexes in pharmaceutical formulations for improving 5-fluorouracil therapeutic efficacy.

  3. Are striatal tyrosine hydroxylase interneurons dopaminergic?

    Science.gov (United States)

    Xenias, Harry S; Ibáñez-Sandoval, Osvaldo; Koós, Tibor; Tepper, James M

    2015-04-22

    Striatal GABAergic interneurons that express the gene for tyrosine hydroxylase (TH) have been identified previously by several methods. Although generally assumed to be dopaminergic, possibly serving as a compensatory source of dopamine (DA) in Parkinson's disease, this assumption has never been tested directly. In TH-Cre mice whose nigrostriatal pathway had been eliminated unilaterally with 6-hydroxydopamine, we injected a Cre-dependent virus coding for channelrhodopsin-2 and enhanced yellow fluorescent protein unilaterally into the unlesioned midbrain or bilaterally into the striatum. Fast-scan cyclic voltammetry in striatal slices revealed that both optical and electrical stimulation readily elicited DA release in control striata but not from contralateral striata when nigrostriatal neurons were transduced. In contrast, neither optical nor electrical stimulation could elicit striatal DA release in either the control or lesioned striata when the virus was injected directly into the striatum transducing only striatal TH interneurons. This demonstrates that striatal TH interneurons do not release DA. Fluorescence immunocytochemistry in enhanced green fluorescent protein (EGFP)-TH mice revealed colocalization of DA, l-amino acid decarboxylase, the DA transporter, and vesicular monoamine transporter-2 with EGFP in midbrain dopaminergic neurons but not in any of the striatal EGFP-TH interneurons. Optogenetic activation of striatal EGFP-TH interneurons produced strong GABAergic inhibition in all spiny neurons tested. These results indicate that striatal TH interneurons are not dopaminergic but rather are a type of GABAergic interneuron that expresses TH but none of the other enzymes or transporters necessary to operate as dopaminergic neurons and exert widespread GABAergic inhibition onto direct and indirect spiny neurons.

  4. Functional characterization of salicylate hydroxylase from the fungal endophyte Epichloë festucae.

    Science.gov (United States)

    Ambrose, Karen V; Tian, Zipeng; Wang, Yifei; Smith, Jordan; Zylstra, Gerben; Huang, Bingru; Belanger, Faith C

    2015-06-09

    Epichloë spp. are symbiotic fungal endophytes of many cool season grasses. The presence of the fungal endophytes often confers insect, drought, and disease tolerance to the host grasses. The presence of the fungal endophytes within the host plants does not elicit host defense responses. The molecular basis for this phenomenon is not known. Epichloë festucae, the endophyte of Festuca rubra, expresses a salicylate hydroxylase similar to NahG from the bacterium Pseudomonas putida. Few fungal salicylate hydroxylase enzymes have been reported. The in planta expression of an endophyte salicylate hydroxylase raised the possibility that degradation of plant-produced salicylic acid is a factor in the mechanism of how the endophyte avoids eliciting host plant defenses. Here we report the characterization of the E. festucae salicylate hydroxylase, designated Efe-shyA. Although the fungal enzyme has the expected activity, based on salicylic acid levels in endophyte-free and endophyte-infected plants it is unlikely that expression of the endophyte salicylate hydroxylase is a factor in the lack of a host defense response to the presence of the fungal endophyte.

  5. Azoxyglycoside content and beta-glycosidase activities in leaves of various cycads.

    Science.gov (United States)

    Yagi, Fumio

    2004-12-01

    Azoxyglycoside contents in leaves of 32 cycad species belonging to 10 cycad genera and the seeds of 4 Encephalartos species were analyzed by HPLC with a YMC-PA03 amide column. Azoxyglycosides were detected in mature leaves of 14 cycad species including 2 Bowenia, 2 Lepidozamia, 1 Microcycas, and 1 Stangeria species, but not in mature leaves of 18 other cycad species; 2 of 3 Ceratozamia, 1 of 3 Cycas, 3 of 3 Dioon, 10 of 11 Encephalartos, 1 of 3 Macrozamia and 1 of 3 Zamia species analyzed. The ratios of beta-glycosidase activity toward cycasin and macrozamin in extracts from the leaves of 9 species belonging to 9 genera were measured. The hydrolysis of cycasin was higher in the leaf extracts of Cycas revoluta, Bowenia spectabilis, Stangeria eriopus and Ceratozamia mexicana, whereas in Lepidozamia hopei, the hydrolysis levels of cycasin and macrozamin were similar. On the other hand, activity toward macrozamin was higher in Dioon edule, Encephalartos villosus, Macrozamia miquelii and Zamia fischeri. The hydrolytic activities in most species were estimated to be sufficient for the release of methylazoxymethanol in leaves analogous to the cyanogenesis of cyanogenic plants. Therefore, hydrolysis of azoxyglycosides by endogenous glycosidase in leaves seems to occur by accidental injury of leaves. However, in M. miquelii leaf extract, hydrolytic activity toward macrozamin was high and the activity toward cycasin was very low, though only cycasin was found in the leaves of this species.

  6. Thiodisaccharides with galactofuranose or arabinofuranose as terminal units: synthesis and inhibitory activity of an exo beta-D-galactofuranosidase.

    Science.gov (United States)

    Repetto, Evangelina; Marino, Carla; Uhrig, M Laura; Varela, Oscar

    2009-04-01

    Thiodisaccharides having beta-D-Galf or alpha-L-Araf units as non-reducing end have been synthesized by the SnCl(4)- or MoO(2)Cl(2)-promoted thioglycosylation of per-O-benzoyl-D-galactofuranose (1), its 1-O-acetyl analogue 4, or per-O-acetyl-alpha-L-arabinofuranose (16) with 6-thioglucose or 6-thiogalactose derivatives. After convenient removal of the protecting groups, the free thiodisaccharides having the basic structure beta-D-Galf(1-->6)-6-thio-alpha-D-Glcp-OMe (5) or beta-D-Galf(1-->6)-6-thio-alpha-D-Galp-OMe (15) were obtained. The respective alpha-L-Araf analogues 18 and 20 were prepared similarly from 16. Alternatively, beta-D-Galf(1-->4)-4-thio-3-deoxy-alpha-L-Xylp-OiPr was synthesized by Michael addition to a sugar enone of 1-thio-beta-d-Galf derivative, generated in situ from the glycosyl isothiourea derivative of 1. The free S-linked disaccharides were evaluated as inhibitors of the beta-galactofuranosidase from Penicillium fellutanum, being 15 and 20 the more active inhibitors against this enzyme.

  7. The "edge effect" after implantation of beta-emitting (55Co) stents with high initial activity.

    Science.gov (United States)

    Cervinka, Pavel; St'ásek, Josef; Costa, Marco Aurelio; Stursa, Jan; Fiser, Miloslav; Vodnanský, Petr; Kocisová, Michaela; Veselka, Josef; Pleskot, Miloslav; Malý, Jaroslav

    2004-01-01

    The aim of this study was to evaluate the incidence and the cause of "edge restenosis" after implantation of high activity 41.1 microCi +/- 1.2 microCi = 1520 kBq +/- 44 kBq, beta-emitting (55Co) stents. Proton bombarding in cyclotron has brought the radioactivity. Intravascular ultrasound (IVUS) investigation has been completed in 10 patients. The angiographies performed at 6 month revealed restenosis >50% in 5 cases (50%). The analysis of edges (5 mm distally and proximally to the last stent struts) showed no significant changes in TVV (187.3 +/- 62.60 mm3 and 176.9 +/- 53.5 mm3) but PMV increase significantly (i.e. neointimal proliferation) from 61.9 +/- 31.2 mm3 to 82.2 +/- 43.4 mm3 (pedge effect"/neointimal hyperplasia was in this trial sharp fall-off in radiation at the edges of the stents.

  8. Adult human liver mesenchymal progenitor cells express phenylalanine hydroxylase.

    Science.gov (United States)

    Baruteau, Julien; Nyabi, Omar; Najimi, Mustapha; Fauvart, Maarten; Sokal, Etienne

    2014-09-01

    Phenylketonuria (PKU) is one of the most prevalent inherited metabolic diseases and is accountable for a severe encephalopathy by progressive intoxication of the brain by phenylalanine. This results from an ineffective L-phenylalanine hydroxylase enzyme (PAH) due to a mutated phenylalanine hydroxylase (PAH) gene. Neonatal screening programs allow an early dietetic treatment with restrictive phenylalanine intake. This diet prevents most of the neuropsychological disabilities but remains challenging for lifelong compliance. Adult-derived human liver progenitor cells (ADHLPC) are a pool of precursors that can differentiate into hepatocytes. We aim to study PAH expression and PAH activity in a differenciated ADHLPC. ADHLPC were isolated from human hepatocyte primary culture of two different donors and differenciated under specific culture conditions. We demonstrated the high expression of PAH and a large increase of PAH activity in differenciated LPC. The age of the donor, the cellular viability after liver digestion and cryopreservation affects PAH activity. ADHLPC might therefore be considered as a suitable source for cell therapy in PKU.

  9. Mechanisms of transcriptional activation of the mouse claudin-5 promoter by estrogen receptor alpha and beta.

    Science.gov (United States)

    Burek, Malgorzata; Steinberg, Katrin; Förster, Carola Y

    2014-07-01

    Claudin-5 is an integral membrane protein and a critical component of endothelial tight junctions that control paracellular permeability. Claudin-5 is expressed at high levels in the brain vascular endothelium. Estrogens have multiple effects on vascular physiology and function. The biological actions of estrogens are mediated by two different estrogen receptor (ER) subtypes, ER alpha and ER beta. Estrogens have beneficial effects in several vascular disorders. Recently we have cloned and characterized a murine claudin-5 promoter and demonstrated 17beta-estradiol (E2)-mediated regulation of claudin-5 in brain and heart microvascular endothelium on promoter, mRNA and protein level. Sequence analysis revealed a putative estrogen response element (ERE) and a putative Sp1 transcription factor binding site in the claudin-5 promoter. The aim of the present study was to further characterize the estrogen-responsive elements of claudin-5 promoter. First, we introduced point mutations in ERE or Sp1 site in -500/+111 or in Sp1 site of -268/+111 claudin-5 promoter construct, respectively. Basal and E2-mediated transcriptional activation of mutated constructs was abrogated in the luciferase reporter gene assay. Next, we examined whether estrogen receptor subtypes bind to the claudin-5 promoter region. For this purpose we performed chromatin immunoprecipitation assays using anti-estrogen receptor antibodies and cellular lysates of E2-treated endothelial cells followed by quantitative PCR analysis. We show enrichment of claudin-5 promoter fragments containing the ERE- and Sp1-binding site in immunoprecipitates after E2 treatment. Finally, in a gel mobility shift assay, we demonstrated DNA-protein interaction of both ER subtypes at ERE. In summary, this study provides evidence that both a non-consensus ERE and a Sp1 site in the claudin-5 promoter are functional and necessary for the basal and E2-mediated activation of the promoter.

  10. The crystal structure of tryptophan hydroxylase with bound amino acid substrate

    DEFF Research Database (Denmark)

    Windahl, Michael Skovbo; Petersen, Charlotte Rode; Christensen, Hans Erik Mølager

    2008-01-01

    124−Asp139 and Ile367−Thr369 close around the active site. Similar structural changes are seen in the catalytic domain of phenylalanine hydroxylase (PAH) upon binding of substrate analogues norleucine and thienylalanine to the PAH·BH4 complex. In fact, the chicken TPH1·Trp·imidazole structure......Tryptophan hydroxylase (TPH) is a mononuclear non-heme iron enzyme, which catalyzes the reaction between tryptophan, O2, and tetrahydrobiopterin (BH4) to produce 5-hydroxytryptophan and 4a-hydroxytetrahydrobiopterin. This is the first and rate-limiting step in the biosynthesis...... acid hydroxylase with bound natural amino acid substrate. The iron coordination can be described as distorted trigonal bipyramidal coordination with His273, His278, and Glu318 (partially bidentate) and one imidazole as ligands. The tryptophan stacks against Pro269 with a distance of 3.9 Å between...

  11. Tryptophan hydroxylase is modulated by L-type calcium channels in the rat pineal gland.

    Science.gov (United States)

    Barbosa, Roseli; Scialfa, Julieta Helena; Terra, Ilza Mingarini; Cipolla-Neto, José; Simonneaux, Valérie; Afeche, Solange Castro

    2008-02-27

    Calcium is an important second messenger in the rat pineal gland, as well as cAMP. They both contribute to melatonin synthesis mediated by the three main enzymes of the melatonin synthesis pathway: tryptophan hydroxylase, arylalkylamine N-acetyltransferase and hydroxyindole-O-methyltransferase. The cytosolic calcium is elevated in pinealocytes following alpha(1)-adrenergic stimulation, through IP(3)-and membrane calcium channels activation. Nifedipine, an L-type calcium channel blocker, reduces melatonin synthesis in rat pineal glands in vitro. With the purpose of investigating the mechanisms involved in melatonin synthesis regulation by the L-type calcium channel, we studied the effects of nifedipine on noradrenergic stimulated cultured rat pineal glands. Tryptophan hydroxylase, arylalkylamine N-acetyltransferase and hydroxyindole-O-methyltransferase activities were quantified by radiometric assays and 5-hydroxytryptophan, serotonin, N-acetylserotonin and melatonin contents were quantified by HPLC with electrochemical detection. The data showed that calcium influx blockaded by nifedipine caused a decrease in tryptophan hydroxylase activity, but did not change either arylalkylamine N-acetyltransferase or hydroxyindole-O-methyltransferase activities. Moreover, there was a reduction of 5-hydroxytryptophan, serotonin, N-acetylserotonin and melatonin intracellular content, as well as a reduction of serotonin and melatonin secretion. Thus, it seems that the calcium influx through L-type high voltage-activated calcium channels is essential for the full activation of tryptophan hydroxylase leading to melatonin synthesis in the pineal gland.

  12. In-vitro profile of a new beta-lactam, ceftobiprole, with activity against methicillin-resistant Staphylococcus aureus.

    Science.gov (United States)

    Jones, M E

    2007-06-01

    Ceftobiprole is a novel, broad-spectrum cephalosporin with in-vitro activity against common Gram-positive and Gram-negative organisms. It forms a stable inhibitory complex with Staphylococcus aureus penicillin-binding protein (PBP) 2' (2a), resulting in enhanced activity against methicillin-resistant S. aureus (MRSA). In recent studies of methicillin-susceptible S. aureus, the ceftobiprole MIC(90) value was most frequently Ceftobiprole is active against Enterococcus faecalis (MIC(90) = 4 mg/L), but not generally active against Enterococcus faecium (MIC(90) > 16 mg/L). Ceftobiprole displayed bactericidal activity against Gram-negative pathogens comparable to that of cefepime, ceftazidime or piperacillin-tazobactam in early studies. However, recent data show activity against Pseudomonas aeruginosa similar to that of cefepime but less than that of ceftazidime. Ceftobiprole, like cefepime, is stable in the presence of most class A non-extended spectrum beta-lactamases and inducible class C beta-lactamases. Ceftobiprole is a poor inducer of AmpC beta-lactamase and a poor substrate for hydrolysis by AmpC beta-lactamase. Studies of ceftobiprole in several animal models have demonstrated potent in-vivo efficacy against infections caused by MRSA, including strains intermediately resistant to vancomycin. It was also efficacious in murine infections caused by Gram-negative bacteria with MIC values ceftobiprole in vitro and in vivo suggests that it may have potential for empirical treatment of suspected Gram-negative and Gram-positive infections, including those caused by MRSA.

  13. A survey of gross alpha and gross beta activity in soil samples in Kinta District, Perak, Malaysia.

    Science.gov (United States)

    Lee, Siak Kuan; Wagiran, Husin; Ramli, Ahmad Termizi

    2014-12-01

    The objective of this study was to determine the gross alpha and gross beta activity concentrations from the different soil types found in the Kinta District, Perak, Malaysia. A total of 128 soil samples were collected and their dose rates were measured 1 m above the ground. Gross alpha and gross beta activity measurements were carried out using gas flow proportional counter, Tennelec Series 5 LB5500 Automatic Low Background Counting System. The alpha activity concentration ranged from 15 to 9634 Bq kg(-1) with a mean value of 1558±121 Bq kg(-1). The beta activity concentration ranged from 142 to 6173 Bq kg(-1) with a mean value of 1112±32 Bq kg(-1). High alpha and beta activity concentrations are from the same soil type. The results of the analysis show a strong correlation between the gross alpha activity concentration and dose rate (R = 0.92). The data obtained can be used as a database for each soil type.

  14. Code Betal to calculation Alpha/Beta activities in environmental samples; Programa de ordenador Betal para el calculo de la actividad Beta/Alfa de muestras ambientales

    Energy Technology Data Exchange (ETDEWEB)

    Romero, L.; Travesi, A.

    1983-07-01

    A codes, BETAL, was developed, written in FORTRAN IV, to automatize calculations and presentations of the result of the total alpha-beta activities measurements in environmental samples. This code performs the necessary calculations for transformation the activities measured in total counts, to pCi/1., bearing in mind the efficiency of the detector used and the other necessary parameters. Further more, it appraise the standard deviation of the result, and calculus the Lower limit of detection for each measurement. This code is written in iterative way by screen-operator dialogue, and asking the necessary data to perform the calculation of the activity in each case by a screen label. The code could be executed through any screen and keyboard terminal, (whose computer accepts Fortran IV) with a printer connected to the said computer. (Author) 5 refs.

  15. Effect of trimethyllead chloride on slowly activating (SV) channels in red beet (Beta vulgaris L.) taproots.

    Science.gov (United States)

    Trela, Zenon; Burdach, Zbigniew; Przestalski, Stanisław; Karcz, Waldemar

    2012-12-01

    The patch-clamp technique was used to examine the effect of trimethyllead chloride (Met(3)PbCl) on SV channel activity in red beet (Beta vulgaris L.) taproot vacuoles. It was found that in the control bath the macroscopic currents showed the typical slow activation and a strong outward rectification of the steady-state currents. An addition of Met(3)PbCl to the bath solution blocked, in a concentration-dependent manner, SV currents in red beet vacuoles. The time constant τ increased several times in the presence of 100 μM trimethyllead chloride at all voltages tested. When single channel properties were analyzed, only little channel activity could be recorded in the presence of 100 μM Met(3)PbCl. Trimethyllead chloride decreased significantly (by about one order of magnitude) the open probability of single channels. The recordings of single channel activity obtained in the presence and absence of Met(3)PbCl showed that organolead only slightly (by ca. 10%) decreased the unitary conductance of single channels. It was also found that Met(3)PbCl diminished significantly the number of SV channel openings, whereas it did not change the opening times of the channels. Taken together, these results suggest that Met(3)PbCl binding site is located outside the channel selectivity filter.

  16. Phenylalanine binding is linked to dimerization of the regulatory domain of phenylalanine hydroxylase.

    Science.gov (United States)

    Zhang, Shengnan; Roberts, Kenneth M; Fitzpatrick, Paul F

    2014-10-28

    Analytical ultracentrifugation has been used to analyze the oligomeric structure of the isolated regulatory domain of phenylalanine hydroxylase. The protein exhibits a monomer-dimer equilibrium with a dissociation constant of ~46 μM; this value is unaffected by the removal of the 24 N-terminal residues or by phosphorylation of Ser16. In contrast, phenylalanine binding (Kd = 8 μM) stabilizes the dimer. These results suggest that dimerization of the regulatory domain of phenylalanine hydroxylase is linked to allosteric activation of the enzyme.

  17. Beta-lactam type molecular scaffolds for antiproliferative activity: synthesis and cytotoxic effects in breast cancer cells.

    Science.gov (United States)

    Meegan, Mary J; Carr, Miriam; Knox, Andrew J S; Zisterer, Daniela M; Lloyd, David G

    2008-10-01

    A series of novel beta-lactam containing compounds are described as antiproliferative agents and potential selective modulators of the oestrogen receptor. The purpose of the study is to evaluate the antiproliferative effects of these compounds on human MCF-7 and MDA MB-231 breast cancer cells. The compounds are designed to contain three aryl ring substituents arranged on the heterocyclic azetidin-2-one (beta-lactam), thus providing conformationally restrained analogues of the triarylethylene arrangement exemplified in the tamoxifen type structure. The compounds demonstrated potency in antiproliferative assays against MCF-7 human breast cancer cell line at low micromolar to nanomolar concentrations with low cytotoxicity and moderate binding affinity to the oestrogen receptor. The effect of a number of aryl and amine functional group substitutions on the antiproliferative activity of the beta-lactam products was explored and a brief computational structure-activity relationship investigation with molecular simulation was investigated.

  18. Performance of a Low Activity Beta-Sensitive SR{sup 90} Water Monitor for Fukushima

    Energy Technology Data Exchange (ETDEWEB)

    Zickefoose, J.; Bronson, F.; Ilie, G.; Jaderstrom, H.; Venkataraman, R. [Canberra Industries Inc. (United States)

    2015-07-01

    There are large volumes of contaminated water from the stabilization efforts at the damaged Fukushima Nuclear Power Plants. This water is being processed to remove radioactivity for eventual release to the environment. An on-line continuously operating system to confirm that the clean-up system is working properly, and to provide prompt feedback of the results is required by the system operator. While gamma emitting nuclides allow for the straight forward approach of gamma spectroscopy to identify and quantify radioactivity in water, pure beta emitting nuclides such as Sr{sup 90} pose a challenging problem. The relatively short range of beta radiation in water requires optimization of the measurement geometry in terms of the source-detector distance and source-detector interface while retaining a background sensitivity low enough to meet the Minimum Detectable Concentration (MDC) of 10 Bq/kg in 180 minutes. This issue is complicated by the continuum nature of the beta spectrum which does not allow for simple nuclide identification. The use of the Monte-Carlo code MCNP to estimate system performance before prototyping vastly increases the success of the end product. Various parameters such as detector size and thickness, water chamber size, water chamber construction materials were evaluated to help choose the optimum geometry. The final design was a system consisting of two large-area (16 x 35 cm) and thin (0.15 mm) plastic scintillators placed very close to a sealed a water chamber. The size of the chamber was optimized to obtain the maximum efficiency for the nuclide being measured (Sr/Y{sup 90}) but to minimize the efficiency for possible interferences (Ru/Rh{sup 106}, Cs{sup 137}). A thin carbon fiber window was selected with adequate material and thickness to contain the water under pressure, but also thin enough (0.5 mm) to allow enough beta radiation to pass through to the active detector volume. The entire measurement geometry is then housed in a thick lead

  19. Absence of aryl hydrocarbon hydroxylase (AHH) in three marine bivalves

    Energy Technology Data Exchange (ETDEWEB)

    Vandermeulen, J.H. (Bedford Inst. of Oceanography, Dartmouth, Nova Scotia); Penrose, W.R.

    1978-05-01

    Bivalves exposed to short-term (4 d) and long-term (6 yr) oil pollution were assayed for aryl hydrocarbon hydroxylase (AHH) and N-demethylase activity. Short-term induction studies were carried out on Mya arenaria, Mytilus edulis, and Ostrea edulis incubated in aqueous extracts of Kuwait crude oil or Bunker C (fuel) oil. For the chronic-induction studies Mya arenaria and Mytilus edulis were collected from oiled clam beds (Arrow Bunker C) in Chedabucto Bay, Nova Scotia. None of the bivalves showed any basal or petroleum-hydrocarbon-induced aryl hydrocarbon hydroxylase or N-demethylase activity, as shown by their inability to metabolize benzopyrene or imipramine. In contrast, oil-free control trout and trout taken from a polluted lake readily metabolized both these compounds. The inability of these bivalves to degrade petroleum aromatic hydrocarbons and the tendency of these compounds to accumulate in their tissues present an opportunity for transfer of unaltered hydrocarbons into the food chain.

  20. Characterization of two carnation petal prolyl 4 hydroxylases.

    Science.gov (United States)

    Vlad, Florina; Tiainen, Päivi; Owen, Carolyn; Spano, Thodhoraq; Daher, Firas Bou; Oualid, Fatiha; Senol, Namik Ozer; Vlad, Daniela; Myllyharju, Johanna; Kalaitzis, Panagiotis

    2010-10-01

    Prolyl 4-hydroxylases (P4Hs) catalyze the proline hydroxylation, a major post-translational modification, of hydroxyproline-rich glycoproteins. Two carnation petal P4H cDNAs, (Dianthus caryophyllus prolyl 4-hydroxylase) DcP4H1 and DcP4H2, were identified and characterized at the gene expression and biochemical level in order to investigate their role in flower senescence. Both mRNAs showed similar patterns of expression with stable transcript abundance during senescence progression and differential tissue-specific expression with DcP4H1 and DcP4H2 strongly expressed in ovaries and stems, respectively. Recombinant DcP4H1 and DcP4H2 proteins were produced and their catalytic properties were determined. Pyridine 2,4-dicarboxylate (PDCA) was identified as a potent inhibitor of the in vitro enzyme activity of both P4Hs and used to determine whether inhibition of proline hydroxylation in petals is involved in senescence progression of cut carnation flowers. PDCA suppressed the climacteric ethylene production indicating a strong correlation between the inhibition of DcP4H1 and DcP4H2 activity in vitro by PDCA and the suppression of climacteric ethylene production in cut carnation flowers.

  1. Antiviral activity of monoterpenes beta-pinene and limonene against herpes simplex virus in vitro.

    Directory of Open Access Journals (Sweden)

    Akram Astani

    2014-06-01

    Full Text Available Essential oils are complex mixtures containing compounds of several different functional- group classes. Depending on the structure, we can distinguish monoterpenes, phenylpropanes, and other components. Here in this study two monoterpene compounds of essential oils, i.e. β-pinene and limonene were examined for their antiviral activity against herpes simplex virus type 1 (HSV-1 in vitro.All antiviral assays were performed using RC-37 cells. Cytotoxicity was determined in a neutral red assay, antiviral assays were performed with HSV-1 strain KOS. The mode of antiviral action was evaluated at different periods during the viral replication cycle. Acyclovir was used as positive antiviral control.Beta-pinenene and limonenen reduced viral infectivity by 100 %. The mode of antiviral action has been determined, only moderate antiviral effects were revealed by monoterpenes when these drugs were added to host cells prior infection or after entry of HSV into cells. However, both monoterpenes exhibited high anti-HSV-1 activity by direct interaction with free virus particles. Both tested drugs interacted with HSV-1 in a dose-dependent manner thereby inactivating viral infection.These results suggest that monoterpenes in essential oils exhibit antiherpetic activity in the early phase of viral multiplication and might be used as potential antiviral agents.

  2. Elevation in sphingomyelin synthase activity is associated with increases in amyloid-beta peptide generation.

    Directory of Open Access Journals (Sweden)

    Jen-Hsiang T Hsiao

    Full Text Available A pathological hallmark of Alzheimer's disease (AD is the presence of amyloid-beta peptide (Aβ plaques in the brain. Aβ is derived from a sequential proteolysis of the transmenbrane amyloid precursor protein (APP, a process which is dependent on the distribution of lipids present in the plasma membrane. Sphingomyelin is a major membrane lipid, however its role in APP processing is unclear. Here, we assessed the expression of sphingomyelin synthase (SGMS1; the gene responsible for sphingomyelin synthesis in human brain and found that it was significantly elevated in the hippocampus of AD brains, but not in the cerebellum. Secondly, we assessed the impact of altering SGMS activity on Aβ generation. Inhibition of SGMS activity significantly reduced the level of Aβ in a dose- and time dependent manner. The decrease in Aβ level occurred without changes in APP expression or cell viability. These results when put together indicate that SGMS activity impacts on APP processing to produce Aβ and it could be a contributing factor in Aβ pathology associated with AD.

  3. TOPOLOGY OF THE MEMBRANE-BOUND ALKANE HYDROXYLASE OF PSEUDOMONAS-OLEOVORANS

    NARCIS (Netherlands)

    van Beilen, J.B.; PENNINGA, D; Witholt, Bernard

    1992-01-01

    The Pseudomonas oleovorans alkane hydroxylase is an integral cytoplasmic membrane protein that is expressed and active in both Escherichia coli and P. oleovorans. Its primary sequence contains eight hydrophobic stretches that could span the membrane as alpha-helices. The topology of alkane hydroxyla

  4. A CYCLIC-AMP RESPONSE ELEMENT IS INVOLVED IN RETINOIC ACID-DEPENDENT RAR-BETA-2 PROMOTER ACTIVATION

    NARCIS (Netherlands)

    KRUYT, FAE; FOLKERS, G; VANDENBRINK, CE; VANDERSAAG, PT; Kruyt, Frank

    1992-01-01

    Activation of the retinoic acid receptor (RAR) beta2 promoter is known to be mediated by a RA response element located in the proximity of the TATA-box. By deletion studies in P19 embryonal carcinoma cells we have analyzed the RARbeta2 promoter for the presence of additional regulatory elements. We

  5. Effect of fenoterol-induced constitutive beta(2)-adrenoceptor activity on contractile receptor function in airway smooth muscle

    NARCIS (Netherlands)

    de Vries, B; Roffel, AF; Zaagsma, J; Meurs, H

    2001-01-01

    In the present study, we investigated the effect of fenoterol-induced constitutive beta (2)-adrenoceptor activity on muscarinic receptor agonist- and histamine-induced bovine tracheal smooth muscle contractions. Bovine tracheal smooth muscle strips were incubated with 10 muM fenoterol or vehicle for

  6. A novel acid-stable, acid-active beta-galactosidase potentially suited to the alleviation of lactose intolerance.

    Science.gov (United States)

    O'Connell, Shane; Walsh, Gary

    2010-03-01

    Extracellular beta-galactosidase produced by a strain of Aspergillus niger van Tiegh was purified to homogeneity using a combination of gel filtration, ion-exchange, chromatofocusing, and hydrophobic interaction chromatographies. The enzyme displayed a temperature optimum of 65 degrees C and a low pH optimum of between 2.0 and 4.0. The monomeric glycosylated enzyme displayed a molecular mass of 129 kDa and an isoelectric point of 4.7. Protein database similarity searching using mass spectrometry-derived sequence data indicate that the enzyme shares homology with a previously sequenced A. niger beta-galactosidase. Unlike currently commercialised products, the enzyme displayed a high level of stability when exposed to simulated gastric conditions in vitro, retaining 68+/-2% of original activity levels. This acid-stable, acid-active beta-galactosidase was formulated, along with a neutral beta-galactosidase from Kluyveromyces marxianus DSM5418, in a novel two-segment capsule system designed to ensure delivery of enzymes of appropriate physicochemical properties to both stomach and small intestine. When subjected to simulated full digestive tract conditions, the twin lactase-containing capsule hydrolyzed, per unit activity, some 3.5-fold more lactose than did the commercial supplemental enzyme. The acid-stable, acid-active enzyme, along with the novel two-segment delivery system, may prove beneficial in the more effective treatment of lactose intolerance.

  7. Expression of mouse beta defensin 2 in Escherichia coli and its broad-spectrum antimicrobial activity

    Directory of Open Access Journals (Sweden)

    Tianxiang Gong

    2011-09-01

    Full Text Available Mature mouse beta defensin 2 (mBD2 is a small cationic peptide with antimicrobial activity. Here we established a prokaryotic expression vector containing the cDNA of mature mBD2 fused with thioredoxin (TrxA, pET32a-mBD2. The vector was transformed into Escherichia Coli (E. coli Rosseta-gami (2 for expression fusion protein. Under the optimization of fermentation parameters: induce with 0.6 mM isopropylthiogalactoside (IPTG at 34ºC in 2×YT medium and harvest at 6 h postinduction, fusion protein TrxA-mBD2 was high expressed in the soluble fraction (>95%. After cleaved fusion protein by enterokinase, soluble mature mBD2 was achieved 6 mg/L with a volumetric productivity. Purified recombinant mBD2 demonstrated clear broad-spectrum antimicrobial activity for fungi, bacteria and virus. The MIC of antibacterial activity of against Staphylococcus aureus was 50 µg/ml. The MIC of against Candida albicans (C. albicans and Cryptococcus neoformans (C. neoformans was 12.5µg/ml and 25µg/ml, respectively. Also, the antimicrobial activity of mBD2 was effected by NaCl concentration. Additionally, mBD2 showed antiviral activity against influenza A virus (IAV, the protective rate for Madin-Darby canine kidney cells (MDCK was 93.86% at the mBD2 concentration of 100 µg/ml. These works might provide a foundation for the following research on the mBD2 as therapeutic agent for medical microbes.

  8. Glucose-induced repression of PPARalpha gene expression in pancreatic beta-cells involves PP2A activation and AMPK inactivation

    DEFF Research Database (Denmark)

    Ravnskjaer, Kim; Boergesen, Michael; Dalgaard, Louise T;

    2006-01-01

    Tight regulation of fatty acid metabolism in pancreatic beta-cells is important for beta-cell viability and function. Chronic exposure to elevated concentrations of fatty acid is associated with beta-cell lipotoxicity. Glucose is known to repress fatty acid oxidation and hence to augment the toxi......Tight regulation of fatty acid metabolism in pancreatic beta-cells is important for beta-cell viability and function. Chronic exposure to elevated concentrations of fatty acid is associated with beta-cell lipotoxicity. Glucose is known to repress fatty acid oxidation and hence to augment...... but not AMPKalpha1 using RNAi suppressed PPARalpha expression, thereby mimicking the effect of glucose. These results indicate that activation of protein phosphatase 2A and subsequent inactivation of AMPK is necessary for glucose repression of PPARalpha expression in pancreatic beta-cells....

  9. 醛固酮合酶基因和11-β羟化酶基因多态性及其单体型与醛固酮瘤发病风险的关系%Association of aldosterone synthase and 11-beta hydroxylase genes polymorphism and haplotype with susceptibility of aldosterone producing adenoma

    Institute of Scientific and Technical Information of China (English)

    王保军; 陈路遥; 李新涛; 马鑫; 杨素霞; 欧阳金芝; 张旭

    2014-01-01

    目的 探讨醛固酮合酶基因(CYP11B2)和11-β羟化酶基因(CYP11B1)多态性及其单体型与醛固酮瘤发病风险的关系.方法 提取81例醛固酮瘤患者和103例对照人群外周血DNA,应用2个独立聚合酶链反应(PCR)和TaqMan探针技术对CYP11B2和CYP11B1基因的7个多态性位点(rs6387、rs6410、rs3097、rs4539、intron2转位、rs1799998、rs 13268025)进行基因分型,采用Logistic回归模型分析不同等位基因、基因型和单体型与醛固酮瘤发病风险的相关性.结果 intron2转位多态性位点C等位基因在病例组中的分布频率(25.3%)高于对照组(15.0%),携带C等位基因的个体较携带W等位基因的个体发生醛固酮瘤的风险增加了1.04倍(P<0.01).rs13268025位点中携带C等位基因的个体较携带T等位基因的个体发生醛固酮瘤的风险增加了0.91倍(P<0.05).7个多态性位点间存在着不同程度的连锁不平衡.单体型分析示AGGAWTT为最常见的单体型,单体型GAGAWTT是AGGAWTT发病风险的4.43倍(P<0.01).结论 CYP11B2和CYP11B1基因多态性与醛固酮瘤发病风险明显相关,intron2转位多态性位点的C等位基因、rs13268025位点的C等位基因、单体型GAGAWTT是醛固酮瘤发病的危险因素.%Objective To evaluate the effects of aldosterone synthase (CYP1 1B2) and 11-beta hydroxylase (CYP1 1 B1) genes polymorphism and haplotype on the susceptibility of aldosterone producing adenoma.Methods Peripheral blood DNA was extracted from 81 aldosterone producing adenoma patients and 103 control subjects.Real-time TaqMan probes technique and two seperate PCRs were used for genotyping seven polymorphism sites of the CYP1 1B2 and CYP11B1 genes (rs6387,rs6410,rs3097,rs4539,intron 2 conversion,rs1799998,rs13268025).Logistic regression model was performed to analyze the relationship of different genotypes or haplotype and the susceptibility of aldosterone producing adenoma.Results The frequency for allele C at site intron 2

  10. Are Striatal Tyrosine Hydroxylase Interneurons Dopaminergic?

    OpenAIRE

    Xenias, Harry S.; Ibáñez-Sandoval, Osvaldo; Koós, Tibor; Tepper, James M.

    2015-01-01

    Striatal GABAergic interneurons that express the gene for tyrosine hydroxylase (TH) have been identified previously by several methods. Although generally assumed to be dopaminergic, possibly serving as a compensatory source of dopamine (DA) in Parkinson's disease, this assumption has never been tested directly. In TH–Cre mice whose nigrostriatal pathway had been eliminated unilaterally with 6-hydroxydopamine, we injected a Cre-dependent virus coding for channelrhodopsin-2 and enhanced yellow...

  11. Measuring the Orientation of Taurine in the Active Site of the Non-Heme Fe (II)/α-Ketoglutarate Dependent Taurine Hydroxylase (TauD) using Electron Spin Echo Envelope Modulation (ESEEM) Spectroscopy

    OpenAIRE

    Casey, Thomas M.; Grzyska, Piotr K.; Hausinger, Robert P.; McCracken, John

    2013-01-01

    The position and orientation of taurine near the non-heme Fe(II) center of the α-ketoglutarate (α-KG) dependent taurine hydroxylase (TauD) was measured using Electron Spin Echo Envelope Modulation (ESEEM) spectroscopy. TauD solutions containing Fe(II), α-KG, and natural abundance taurine or specifically deuterated taurine were prepared anaerobically and treated with nitric oxide (NO) to make an S=3/2 {FeNO}7 complex that is suitable for robust analysis with EPR spectroscopy. Using ratios of E...

  12. Tumors initiated by constitutive Cdk2 activation exhibit transforming growth factor beta resistance and acquire paracrine mitogenic stimulation during progression

    DEFF Research Database (Denmark)

    Corsino, P.; Davis, B.; Law, M.;

    2007-01-01

    mediate some of the transforming effects that result from cyclin D1 overexpression in human breast cancers. MMTV-DIK2 cancer cells express the hepatocyte growth factor (HGF) receptor, c-Met. MMTV-D1K2 cancer cells also secrete transforming growth factor beta (TGF beta), but are relatively resistant to TGF......Cyclin D1/cyclin-dependent kinase 2 (Cdk2) complexes are present at high frequency in human breast cancer cell lines, but the significance of this observation is unknown. This report shows that expression of a cyclin D1-Cdk2 fusion protein under the control of the mouse mammary tumor virus (MMITV...... beta antiproliferative effects. Fibroblasts derived from MMTV-DIK2 tumors secrete factors that stimulate the proliferation of MMTV-D1K2 cancer cells, stimulate c-Met tyrosine phosphorylation, and stimulate the phosphorylation of the downstream signaling intermediates p70(s6k) and Akt on activating...

  13. Partially deglycosylated equine LH preferentially activates beta-arrestin-dependent signaling at the follicle-stimulating hormone receptor.

    Science.gov (United States)

    Wehbi, Vanessa; Tranchant, Thibaud; Durand, Guillaume; Musnier, Astrid; Decourtye, Jérémy; Piketty, Vincent; Butnev, Vladimir Y; Bousfield, George R; Crépieux, Pascale; Maurel, Marie-Christine; Reiter, Eric

    2010-03-01

    Deglycosylated FSH is known to trigger poor Galphas coupling while efficiently binding its receptor. In the present study, we tested the possibility that a deglycosylated equine LH (eLHdg) might be able to selectively activate beta-arrestin-dependent signaling. We compared native eLH to an eLH derivative [i.e. truncated eLHbeta (Delta121-149) combined with asparagine56-deglycosylated eLHalpha (eLHdg)] previously reported as an antagonist of cAMP accumulation at the FSH receptor (FSH-R). We confirmed that, when used in conjunction with FSH, eLHdg acted as an antagonist for cAMP accumulation in HEK-293 cells stably expressing the FSH-R. Furthermore, when used alone at concentrations up to 1 nM, eLHdg had no detectable agonistic activity on cAMP accumulation, protein kinase A activity or cAMP-responsive element-dependent transcriptional activity. At higher concentrations, however, a weak agonistic action was observed with eLHdg, whereas eLH led to robust responses whatever the concentration. Both eLH and eLHdg triggered receptor internalization and led to beta-arrestin recruitment. Both eLH and eLHdg triggered ERK and ribosomal protein (rp) S6 phosphorylation at 1 nM. The depletion of endogenous beta-arrestins had only a partial effect on eLH-induced ERK and rpS6 phosphorylation. In contrast, ERK and rpS6 phosphorylation was completely abolished at all time points in beta-arrestin-depleted cells. Together, these results show that eLHdg has the ability to preferentially activate beta-arrestin-dependent signaling at the FSH-R. This finding provides a new conceptual and experimental framework to revisit the physiological meaning of gonadotropin structural heterogeneity. Importantly, it also opens a field of possibilities for the development of selective modulators of gonadotropin receptors.

  14. AMP-activated protein kinase (AMPK mediates nutrient regulation of thioredoxin-interacting protein (TXNIP in pancreatic beta-cells.

    Directory of Open Access Journals (Sweden)

    Maayan Shaked

    Full Text Available Thioredoxin-interacting protein (TXNIP regulates critical biological processes including inflammation, stress and apoptosis. TXNIP is upregulated by glucose and is a critical mediator of hyperglycemia-induced beta-cell apoptosis in diabetes. In contrast, the saturated long-chain fatty acid palmitate, although toxic to the beta-cell, inhibits TXNIP expression. The mechanisms involved in the opposing effects of glucose and fatty acids on TXNIP expression are unknown. We found that both palmitate and oleate inhibited TXNIP in a rat beta-cell line and islets. Palmitate inhibition of TXNIP was independent of fatty acid beta-oxidation or esterification. AMP-activated protein kinase (AMPK has an important role in cellular energy sensing and control of metabolic homeostasis; therefore we investigated its involvement in nutrient regulation of TXNIP. As expected, glucose inhibited whereas palmitate stimulated AMPK. Pharmacologic activators of AMPK mimicked fatty acids by inhibiting TXNIP. AMPK knockdown increased TXNIP expression in presence of high glucose with and without palmitate, indicating that nutrient (glucose and fatty acids effects on TXNIP are mediated in part via modulation of AMPK activity. TXNIP is transcriptionally regulated by carbohydrate response element-binding protein (ChREBP. Palmitate inhibited glucose-stimulated ChREBP nuclear entry and recruitment to the Txnip promoter, thereby inhibiting Txnip transcription. We conclude that AMPK is an important regulator of Txnip transcription via modulation of ChREBP activity. The divergent effects of glucose and fatty acids on TXNIP expression result in part from their opposing effects on AMPK activity. In light of the important role of TXNIP in beta-cell apoptosis, its inhibition by fatty acids can be regarded as an adaptive/protective response to glucolipotoxicity. The finding that AMPK mediates nutrient regulation of TXNIP may have important implications for the pathophysiology and treatment

  15. Leu85 in the beta1-beta2 linker of ASIC1 slows activation and decreases the apparent proton affinity by stabilizing a closed conformation.

    Science.gov (United States)

    Li, Tianbo; Yang, Youshan; Canessa, Cecilia M

    2010-07-16

    Acid-sensing ion channels (ASICs) are proton-activated channels expressed in neurons of the central and peripheral nervous systems where they modulate neuronal activity in response to external increases in proton concentration. The size of ASIC1 currents evoked by a given local acidification is determined by the number of channels in the plasma membrane and by the apparent proton affinities for activation and steady-state desensitization of the channel. Thus, the magnitude of the pH drop and the value of the baseline pH both are functionally important. Recent characterization of ASIC1s from an increasing number of species has made evident that proton affinities of these channels vary across vertebrates. We found that in species with high baseline plasma pH, e.g. frog, shark, and fish, ASIC1 has high proton affinity compared with the mammalian channel. The beta1-beta2 linker in the extracellular domain, specifically by the substitution M85L, determines the interspecies differences in proton affinities and also the time course of ASIC1 macroscopic currents. The mechanism underlying these observations is a delay in channel opening after application of protons, most likely by stabilizing a closed conformation that decreases the apparent affinity to protons and also slows the rise and decay phases of the current. Together, the results suggest evolutionary adaptation of ASIC1 to match the value of the species-specific plasma pH. At the molecular level, adaptation is achieved by substitutions of nonionizable residues rather than by modification of the channel proton sensor.

  16. Amyloid beta inhibits olfactory bulb activity and the ability to smell.

    Directory of Open Access Journals (Sweden)

    Reynaldo Alvarado-Martínez

    Full Text Available Early olfactory dysfunction has been consistently reported in both Alzheimer's disease (AD and in transgenic mice that reproduce some features of this disease. In AD transgenic mice, alteration in olfaction has been associated with increased levels of soluble amyloid beta protein (Aβ as well as with alterations in the oscillatory network activity recorded in the olfactory bulb (OB and in the piriform cortex. However, since AD is a multifactorial disease and transgenic mice suffer a variety of adaptive changes, it is still unknown if soluble Aβ, by itself, is responsible for OB dysfunction both at electrophysiological and behavioral levels. Thus, here we tested whether or not Aβ directly affects OB network activity in vitro in slices obtained from mice and rats and if it affects olfactory ability in these rodents. Our results show that Aβ decreases, in a concentration- and time-dependent manner, the network activity of OB slices at clinically relevant concentrations (low nM and in a reversible manner. Moreover, we found that intrabulbar injection of Aβ decreases the olfactory ability of rodents two weeks after application, an effect that is not related to alterations in motor performance or motivation to seek food and that correlates with the presence of Aβ deposits. Our results indicate that Aβ disrupts, at clinically relevant concentrations, the network activity of the OB in vitro and can trigger a disruption in olfaction. These findings open the possibility of exploring the cellular mechanisms involved in early pathological AD as an approach to reduce or halt its progress.

  17. Betacyanin accumulation and guaiacol peroxidase activity in Beta vulgaris L. leaves following copper stress

    Directory of Open Access Journals (Sweden)

    Janet M. León Morales

    2012-07-01

    Full Text Available The effect of copper stress on betacyanin accumulation and guaiacol peroxidase (GPOD activity in leaves of different age was evaluated in red beet (Beta vulgaris L. var. Crosby Egyptian plants. In hydroponic culture, plants were treated with 0.3 μM (control, 50 μM, 100 μM, and 250 μM of CuSO4 for 6 days. Copper was taken up and accumulated in old roots but was not translocated to leaves. However in young leaves, the increase of lipid peroxidation and reduction of growth were evident from day 3 of copper exposure; whereas in old leaves, the lipid peroxidation and growth were the same from either copper-treated or control plants. In response to copper exposure, the betacyanin accumulation was evident in young leaves by day 3, and continued to increase until day 6. Betacyanin only were accumulated in old leaves until day 6, but the contents were from 4 to 5 times lower than those observed in young leaves at the same copper concentrations. GPOD activity increased 3.3- and 1.4-fold in young and old leaves from day 3 of copper treatment respectively, but only in the young leaves was sustained at the same level until day 6. Old roots shown betacyanin in the control plants, but the betacyanin level and growth were reduced with the copper exposure. In contrast, young roots emerged by copper effect also accumulated copper and showed the highest betacyanin content of all plant parts assayed. These results indicate that betacyanin accumulation and GPOD activity are defense responses to copper stress in actively growing organs.

  18. Antibody-mediated activation of a defective beta-D-galactosidase: dimeric form of the activatable mutant enzyme.

    Science.gov (United States)

    Conway de Macario, E; Ellis, J; Guzman, R; Rotman, B

    1978-02-01

    Sedimentation analyses of AMEF, an activatable mutant beta-D-galactosidase (beta-D-galactoside galactohydrolase, EC 3.2.1.23), and the products of its reaction with Fab fragments of activating antibody show that this enzyme exists mainly as 10S dimers. Activation of AMEF by purified antibody resulted in formation of 16S tetramers. A unifying hypothesis postulating a dimer--tetramer equilibrium accounts for this observation as the counterpart of inactivation, which was shown to involve the breakdown of tetramers into inactive subunits [Roth, R. A. & Rotman, B. (1975) Biochem. Biophys. Res. Commun. 67, 1382--1390]. Conditions are described under which AMEF loses the specific antigenic determinant(s) responsible for binding activating antibody, allowing its subsequent use as an absorption to obtain immunologically purified activating antibody,

  19. TGF-beta expression during rat pregnancy and activity on decidual cell survival

    Directory of Open Access Journals (Sweden)

    Déry Marie-Claude

    2005-05-01

    Full Text Available Abstract Background During early rat pregnancy, trophoblast of the tiny embryo joins with the endometrium and epithelial cells undergo apoptosis. Near the end of pregnancy, regression of the decidua basalis (DB is also observed (from day 14 to 20. However, little is known about the intra-cellular and molecular mechanisms involved in apoptosis regulation in the uterus during pregnancy. The objective of the present study was to investigate the presence and the developmental expression of transforming growth factor-beta isoforms (TGF-beta well known differentiation factor in the rat endometrium throughout pregnancy and its action in vitro using cultured endometrial stromal cells. Methods In vivo: Rats were killed at different days of pregnancy (days 2–20 and uteri removed to collect endometrial protein extracts or the uteri were fixed, embedded and sectioned for immunohistochemistry (IHC and in situ cell death analyses using TdT-mediated dUTP nick end labeling (TUNEL. In vitro: Rats were ovariectomized and decidualization was induced using sex steroids. Endometrial stromal decidual cells were then collected and cultured. Results An increase of apoptosis in the DB on days 14, 16 and 18 was observed. Cleaved caspase-3 was clearly detected during regression of the DB by Western analysis and immunofluorescence. Western analyses using endometrial protein extracts demonstrated that TGF-beta1, TGF-beta2 and TGF-beta3 were highly expressed at the time of DB regression (day 14. During early pregnancy, TGF-beta1 and -beta2 expressions raised at days 5.5 to 6.5. TGF-beta3 protein was not detected during early pregnancy. IHC analyses revealed that TGF-beta1 and -2 were found surrounding both epithelium (luminal and glandular in the stroma compartment at the implantation site, and TGF-beta3 was mainly located surrounding endometrial epithelium in the stroma compartment. Smad2 phosphorylation was increased at the time of DB regression. In vitro studies using

  20. Expression and purification of the metal-containing monooxygenases tryptophan hydroxylase and dopamine β-hydroxylase

    DEFF Research Database (Denmark)

    Karlsen, Pernille Efferbach

    to abnormal levels of the neurotransmitters serotonin, dopamine and norepinephrine and the regulation of tryptophan hydroxylase and dopamine β-hydroxylase. These include depression, anxiety disorders, obsessive compulsive disorder (OCD), schizophrenia, Parkinson's disease and attention deficit......-containing enzyme which belongs to the aromatic amino acid hydroxylase (AAAH) family. It exist in two isoforms, TPH1 and TPH2, which are expressed in different tissues and have different properties. TPH is known as a very diffcult protein to work with especially due to instability and only truncated forms of TPH1...... to the family of ascorbate dependent type II Cu monooxygenases. Very little knowledge exist on DβH and most of it comes from investigations of related proteins. Attempts to express human DβH in bacterial systems have been done in the Metalloprotein Chemistry and Engineering Group, but at present no system...

  1. Effects of transforming growth factor-[beta] and budesonide on mitogen-activated protein kinase activation and apoptosis in airway epithelial cells.

    Science.gov (United States)

    Pelaia, Girolamo; Cuda, Giovanni; Vatrella, Alessandro; Fratto, Donatella; Grembiale, Rosa D; Tagliaferri, Pierosandro; Maselli, Rosario; Costanzo, Francesco S; Marsico, Serafino A

    2003-07-01

    Airway epithelial cells play a central role in the inflammatory, apoptotic, and remodeling processes associated with asthma. Within this context, a key function is exerted by transforming growth factor-beta (TGF-beta), whose biological effects are mediated at least in part by mitogen-activated protein kinases (MAPKs). The aim of our study was to investigate, in primary cultures of human bronchial epithelial cells (HBEC), the effects of TGF-beta (10 ng/ml) on both MAPK activation and apoptosis, in the presence or absence of a pretreatment with budesonide (10-8 M). MAPK activation was detected by Western blotting, using anti-phospho-MAPK monoclonal antibodies, which specifically recognize the phosphorylated, active forms of these enzymes. Apoptosis was assayed by caspase-3 activation and fluorescence microscopy, using annexin-V (An-V) and propidium iodide (PI) as markers of cell death. Our results show that TGF-beta induced a marked ( reverse similar 9-fold) increase in p38 MAPK phosphorylation, and also dramatically enhanced cell death, which was completely prevented by specific MAPK inhibitors. Both MAPK activation and apoptosis were effectively inhibited by budesonide (BUD), thereby suggesting that the powerful antiapoptotic action of inhaled glucocorticoids may be very important for their protective role against epithelial injury, which represents a key pathogenic event in asthma.

  2. TGF-beta 1 Gene-Activated Matrices Regulated the Osteogenic Differentiation of BMSCs

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Poly (lactic acid/glycolic acid/asparagic acid-co-polyethylene glycol)(PLGA-[ASP-PEG]) scaffold materials were linked with a novel nonviral vector (K)16GRGDSPC through cross linker Sulfo-LC-SPDP to construct a new type of nonviral gene transfer system. Eukaryotic expressing vector containing transforming growth factor beta 1 (pcDNA3-TGFβ1) was encapsulated by the system. Bone marrow stromal cells (BMSCs) obtained from rabbit were cultured on PLGA-[ASP-PEG] modified by (K)16GRGDSPC and TGF-β1 gene and PLGA-[ASP-PEG] modified by (K)16GRGDSPC and empty vector pcDNA3 as control.The expressions of osteogenic makers of the BMSCs cultured on the TGF-β1 gene-activated scaffold materials were found significantly higher than those of the control group (P<0.05). A brand-new way was provided for regulating seed cells to directionally differentiate into osteoblasts for bone defect restoration in bone tissue engineering.

  3. Beta-receptor activation increases sodium current in guinea pig heart

    Institute of Scientific and Technical Information of China (English)

    Hong-wei WANG; Zhi-fang YANG; Yin ZHANG; Jian-min YANG; Yuan-mou LIU; Ci-zhen LI

    2009-01-01

    Aim: To study the influence of β-receptor activation on sodium channel current and the physiological significance of increased sodium current with regard to the increased cardiac output caused by sympathetic excitation.Methods: Multiple experimental approaches, including ECG, action potential recording with conventional microelectrodes, whole-cell current measurements, single-channel recordings, and pumping-force measurements, were applied to guinea pig hearts and isolated ventricular myocytes.Results: Isoprenaline was found to dose-dependently shorten QRS waves, increase the amplitude and the Vmaxof action potentials, aug-ment the fast sodium current, and increase the occurrence frequencies and open time constants of the long-open and burst modes of the sodium channel. Increased levels of membrane-permeable cAMP have similar effects. In the presence of a calcium channel blocker, TTX reversed the increased pumping force produced by isoprenaline.Conclusion: Beta-adrenergic modulation increases the inward sodium current and accelerates the conduction velocity within the ventri-cles by changing the sodium channel modes, which might both be conducive to the synchronous contraction of the heart and enhance its pumping function.

  4. Beta-adrenergic receptor sensitivity, autonomic balance and serotonergic activity in practitioners of Transcendental Meditation

    Energy Technology Data Exchange (ETDEWEB)

    Hill, D.A.

    1989-01-01

    The aim of this thesis was to investigate the acute autonomic effects of the Transcendental Meditation Program (TM) and resolve the conflict arising from discrepant neurochemical and psychophysiological data. Three experimental investigations were performed. The first examined beta{sub 2}-adrenergic receptors (AR's) on peripheral blood lymphocytes, via (I{sup 125})iodocyanopindolol binding, in 10 male mediating and 10 age matched non-meditating control subjects, to test the hypothesis that the long-term practice of TM and the TM Sidhi Program (TMSP) reduces end organ sensitivity to adrenergic agonists. The second investigated respiratory sinus arrhythmia (an indirect measure of cardiac Parasympathetic Nervous System tone), and skin resistance (a measure of Sympathetic Nervous System tone) during periods of spontaneous respiratory apneusis, a phenomenon occurring during TM that is known to mark the subjective experience of transcending. The third was within subject investigation of the acute effects of the TMSP on 5-hydroxytryptamine (5-HT) activity. Platelet 5-HT was assayed by high pressure liquid chromatography with electrochemical detection, plasma prolactin (PL) and lutenizing hormone (LH) by radioimmunoassay, tryptophan by spectrofluorimetry, and alpha-1-acid glycoprotein (AGP, a modulator of 5-HT uptake) by radial immunodiffusion assay.

  5. Beat-induced fluctuations in auditory cortical beta-band activity: Using EEG to measure age-related changes

    Directory of Open Access Journals (Sweden)

    Laura K Cirelli

    2014-07-01

    Full Text Available People readily extract regularity in rhythmic auditory patterns, enabling prediction of the onset of the next beat. Recent magnetoencephalography (MEG research suggests that such prediction is reflected by the entrainment of oscillatory networks in the brain to the tempo of the sequence. In particular, induced beta-band oscillatory activity from auditory cortex decreases after each beat onset and rebounds prior to the onset of the next beat across tempi in a predictive manner. The objective of the present study was to examine the development of such oscillatory activity by comparing electroencephalography (EEG measures of beta-band fluctuations in 7-year-old children to adults. EEG was recorded while participants listened passively to isochronous tone sequences at three tempi (390, 585, and 780ms for onset-to-onset interval. In adults, induced power in the high beta-band (20-25 Hz decreased after each tone onset and rebounded prior to the onset of the next tone across tempo conditions, consistent with MEG findings. In children, a similar pattern was measured in the two slower tempo conditions, but was weaker in the fastest condition. The results indicate that the beta-band timing network works similarly in children, although there are age-related changes in consistency and the tempo range over which it operates.

  6. Mechanistic studies of cancer cell mitochondria- and NQO1-mediated redox activation of beta-lapachone, a potentially novel anticancer agent

    Energy Technology Data Exchange (ETDEWEB)

    Li, Jason Z. [Virginia Tech CRC, Blacksburg, VA (United States); Ke, Yuebin [Shenzhen Center for Disease Control and Prevention, Shenzhen 518055 (China); Misra, Hara P. [Virginia Tech CRC, Blacksburg, VA (United States); Trush, Michael A. [Johns Hopkins University Bloomberg School of Public Health, Baltimore, MD (United States); Li, Y. Robert [Campbell University School of Osteopathic Medicine, Buies Creek, NC (United States); Virginia Tech-Wake Forest University SBES, Blacksburg, VA (United States); Department of Biology, University of North Carolina at Greensboro, NC (United States); Zhu, Hong, E-mail: zhu@campbell.edu [Campbell University School of Osteopathic Medicine, Buies Creek, NC (United States); Jia, Zhenquan, E-mail: z_jia@uncg.edu [Department of Biology, University of North Carolina at Greensboro, NC (United States)

    2014-12-15

    Beta-lapachone (beta-Lp) derived from the Lapacho tree is a potentially novel anticancer agent currently under clinical trials. Previous studies suggested that redox activation of beta-Lp catalyzed by NAD(P)H:quinone oxidoreductase 1 (NQO1) accounted for its killing of cancer cells. However, the exact mechanisms of this effect remain largely unknown. Using chemiluminescence and electron paramagnetic resonance (EPR) spin-trapping techniques, this study for the first time demonstrated the real-time formation of ROS in the redox activation of beta-lapachone from cancer cells mediated by mitochondria and NQO1 in melanoma B16–F10 and hepatocellular carcinoma HepG2 cancer cells. ES936, a highly selective NQO1 inhibitor, and rotenone, a selective inhibitor of mitochondrial electron transport chain (METC) complex I were found to significantly block beta-Lp meditated redox activation in B16–F10 cells. In HepG2 cells ES936 inhibited beta-Lp-mediated oxygen radical formation by ∼ 80% while rotenone exerted no significant effect. These results revealed the differential contribution of METC and NQO1 to beta-lapachone-induced ROS formation and cancer cell killing. In melanoma B16–F10 cells that do not express high NQO1 activity, both NOQ1 and METC play a critical role in beta-Lp redox activation. In contrast, in hepatocellular carcinoma HepG2 cells expressing extremely high NQO1 activity, redox activation of beta-Lp is primarily mediated by NQO1 (METC plays a minor role). These findings will contribute to our understanding of how cancer cells are selectively killed by beta-lapachone and increase our ability to devise strategies to enhance the anticancer efficacy of this potentially novel drug while minimizing its possible adverse effects on normal cells. - Highlights: • Both isolated mitochondria and purified NQO1 are able to generate ROS by beta-Lp. • The differential roles of mitochondria and NQO1 in mediating redox activation of beta-Lp • In cancer cells with

  7. Molecular characterization and allergenic activity of Lyc e 2 (beta-fructofuranosidase), a glycosylated allergen of tomato.

    Science.gov (United States)

    Westphal, Sandra; Kolarich, Daniel; Foetisch, Kay; Lauer, Iris; Altmann, Friedrich; Conti, Amedeo; Crespo, Jesus F; Rodríguez, Julia; Enrique, Ernesto; Vieths, Stefan; Scheurer, Stephan

    2003-03-01

    Until now, only a small amount of information is available about tomato allergens. In the present study, a glycosylated allergen of tomato (Lycopersicon esculentum), Lyc e 2, was purified from tomato extract by a two-step FPLC method. The cDNA of two different isoforms of the protein, Lyc e 2.01 and Lyc e 2.02, was cloned into the bacterial expression vector pET100D. The recombinant proteins were purified by electroelution and refolded. The IgE reactivity of both the recombinant and the natural proteins was investigated with sera of patients with adverse reactions to tomato. IgE-binding to natural Lyc e 2 was completely inhibited by the pineapple stem bromelain glycopeptide MUXF (Man alpha 1-6(Xyl beta 1-2)Man beta 1-4GlcNAc beta 1-4(Fuc alpha 1-3)GlcNAc). Accordingly, the nonglycosylated recombinant protein isoforms did not bind IgE of tomato allergic patients. Hence, we concluded that the IgE reactivity of the natural protein mainly depends on the glycan structure. The amino acid sequences of both isoforms of the allergen contain four possible N-glycosylation sites. By application of MALDI-TOF mass spectrometry the predominant glycan structure of the natural allergen was identified as MMXF (Man alpha 1-6(Man alpha 1-3)(Xyl beta 1-2)Man beta 1-4GlcNAc beta 1-4(Fuc alpha 1-3) GlcNAc). Natural Lyc e 2, but not the recombinant protein was able to trigger histamine release from passively sensitized basophils of patients with IgE to carbohydrate determinants, demonstrating that glycan structures can be important for the biological activity of allergens.

  8. Modeling clustered activity increase in amyloid-beta positron emission tomographic images with statistical descriptors

    Directory of Open Access Journals (Sweden)

    Shokouhi S

    2015-04-01

    Full Text Available Sepideh Shokouhi,1 Baxter P Rogers,1 Hakmook Kang,2 Zhaohua Ding,1 Daniel O Claassen,3 John W Mckay,1 William R Riddle1On behalf of the Alzheimer’s Disease Neuroimaging Initiative1Department of Radiology and Radiological Sciences, Vanderbilt University Institute of Imaging Science, 2Department of Biostatistics, 3Department of Neurology, Vanderbilt University, Nashville, TN, USABackground: Amyloid-beta (Aβ imaging with positron emission tomography (PET holds promise for detecting the presence of Aβ plaques in the cortical gray matter. Many image analyses focus on regional average measurements of tracer activity distribution; however, considerable additional information is available in the images. Metrics that describe the statistical properties of images, such as the two-point correlation function (S2, have found wide applications in astronomy and materials science. S2 provides a detailed characterization of spatial patterns in images typically referred to as clustering or flocculence. The objective of this study was to translate the two-point correlation method into Aβ-PET of the human brain using 11C-Pittsburgh compound B (11C-PiB to characterize longitudinal changes in the tracer distribution that may reflect changes in Aβ plaque accumulation.Methods: We modified the conventional S2 metric, which is primarily used for binary images and formulated a weighted two-point correlation function (wS2 to describe nonbinary, real-valued PET images with a single statistical function. Using serial 11C-PiB scans, we calculated wS2 functions from two-dimensional PET images of different cortical regions as well as three-dimensional data from the whole brain. The area under the wS2 functions was calculated and compared with the mean/median of the standardized uptake value ratio (SUVR. For three-dimensional data, we compared the area under the wS2 curves with the subjects’ cerebrospinal fluid measures.Results: Overall, the longitudinal changes in wS2

  9. Changes in cortical beta activity related to a biceps brachii movement task while experiencing exercise induced muscle damage.

    Science.gov (United States)

    Plattner, Kristina; Lambert, Michael I; Tam, Nicholas; Lamberts, Robert P; Baumeister, Jochen

    2014-01-17

    Exercise-induced-muscle-damage (EIMD) is a well-described phenomenon which leads to decreased force output and altered neuromuscular function. How these symptoms of EIMD affect brain function, in particular cortical activity has not been described. Therefore the aim of this study was to investigate the relationship between the symptoms of EIMD and cortical beta (β) activity during a submaximal biceps brachii movement. Half of the subjects participated in an EIMD protocol. Control and EIMD groups were monitored for 132h thereafter. Muscle pain scores in the EIMD group peaked after 36h with the lowest muscle torque reported at 12h. Beta-1 and -2 activity was increased in the frontal and parietal area in the experimental group at 12h. This suggests an impact of EIMD induced neuromuscular changes on the cortical proprioceptive and motor perceptive networks. Beta-2 activity decreased in the control group over time suggesting a loss in focused attention and greater familiarization with the protocol as the study progressed. These data suggest that a change in β-1 and -2 activity is associated with integrating movement perception and proprioception post-EIMD.

  10. Sequential changes in chromatin structure during transcriptional activation in the beta globin LCR and its target gene.

    Science.gov (United States)

    Kim, Kihoon; Kim, AeRi

    2010-09-01

    Chromatin structure is modulated during transcriptional activation. The changes include the association of transcriptional activators, formation of hypersensitive sites and covalent modifications of histones. To understand the order of the various changes accompanying transcriptional activation, we analyzed the mouse beta globin gene, which is transcriptionally inducible in erythroid MEL cells over a time course of HMBA treatment. Transcription of the globin genes requires the locus control region (LCR) consisting of several hypersensitive sites (HSs). Erythroid specific transcriptional activators such as NF-E2, GATA-1, TAL1 and EKLF were associated with the LCR in the uninduced state before transcriptional activation. The HSs of the LCR were formed in this state as revealed by high sensitivity to DNase I and MNase attack. However the binding of transcriptional activators and the depletion of histones were observed in the promoter of the beta globin gene only after transcriptional activation. In addition, various covalent histone modifications were sequentially detected in lysine residues of histone H3 during the activation. Acetylation of K9, K36 and K27 was notable in both LCR HSs and gene after induction but before transcriptional initiation. Inactive histone marks such as K9me2, K36me2 and K27me2 were removed coincident with transcriptional initiation in the gene region. Taken together, these results indicate that LCR has a substantially active structure in the uninduced state while transcriptional activation serially adds active marks, including histone modifications, and removes inactive marks in the target gene of the LCR.

  11. Alzheimer's beta-amyloid peptides can activate the early components of complement classical pathway in a C1q-independent manner.

    Science.gov (United States)

    Bergamaschini, L; Canziani, S; Bottasso, B; Cugno, M; Braidotti, P; Agostoni, A

    1999-03-01

    beta-Amyloid (beta-A) accumulates in the brain of patients with Alzheimer's disease (AD) and is presumably involved in the pathogenesis of this disease, on account of its neurotoxicity and complement-activating ability. Although assembly of beta-A in particular aggregates seems to be crucial, soluble non-fibrillar beta-A may also be involved. Non-fibrillar beta-A does not bind C1q, so we investigated alternative mechanisms of beta-A-dependent complement activation in vitro. On incubation with normal human plasma, non-fibrillar beta-A 1-42, and truncated peptide 1-28, induced dose-dependent activation of C1s and C4, sparing C3, as assessed by densitometric analysis of immunostained membrane after SDS-PAGE and Western blotting. The mechanism of C4 activation was not dependent on C1q, because non-fibrillar beta-A can still activate C1s and C4 in plasma genetically deficient in C1q (C1qd). In Factor XII-deficient plasma (F.XIId) the amount of cleaved C4 was about 5-10% less that in C1qd and in normal EDTA plasma; the reconstitution of F.XIId plasma with physiologic concentrations of F.XII resulted in an increased (8-15%) beta-A-dependent cleavage of C4. Thus our results indicate that the C1q-independent activation of C1 and C4 can be partially mediated by the activation products of contact system. Since the activation of contact system and of C4 leads to generation of several humoral inflammatory peptides, non-fibrillar beta-A might play a role in initiating the early inflammatory reactions leading to a multistep cascade contributing to neuronal and clinical dysfunction of AD brain.

  12. Differential hepatocellular zonation pattern of cholesterol 7alpha-hydroxylase (Cyp7a1) and sterol 12alpha-hydroxylase (Cyp8b1) in the mouse.

    Science.gov (United States)

    Wang, Jin; Olin, Maria; Rozell, Björn; Björkhem, Ingemar; Einarsson, Curt; Eggertsen, Gösta; Gåfvels, Mats

    2007-03-01

    The synthesis of primary bile acids is confined to the hepatocytes. This study aimed to evaluate the expression pattern within the liver architecture of the rate-limiting enzyme of the neutral pathway, cholesterol 7alpha-hydroxylase (Cyp7a1), and sterol 12alpha-hydroxylase (Cyp8b1), the enzyme necessary for the synthesis of cholic acid. Specific Cyp8b1 and Cyp7a1 peptide antiserums were used for immunohistochemical staining of livers from wild type and Cyp8b1 null mice, the latter instead expressing beta-galactosidase (beta-Gal) as a replacement reporter gene. Cyp8b1 was mainly expressed in the hepatocytes in a zonal pattern surrounding the central vein while the areas surrounding the portal zones showed much lower levels. The zonation was maintained in cholic acid-depleted mice using beta-Gal as a reporter protein. Cyp7a1 expression in wild type mice also showed a zonal distribution pattern, although less distinct, with a maximal expression within a 1-2 cell thick layer of hepatocytes surrounding the central vein. In Cyp8b1 null mice, a more intense staining was obtained, in accordance with the higher expression level of Cyp7a1, although the overall expression pattern was maintained. Our results in mice indicate possible differences in the regulation of the cellular zonation of Cyp7a1 and Cyp8b1. Also, cholic acid affects the set-point of Cyp7a1 expression but not its zonal distribution.

  13. Hydroxylase inhibition attenuates colonic epithelial secretory function and ameliorates experimental diarrhea.

    LENUS (Irish Health Repository)

    Ward, Joseph B J

    2012-02-01

    Hydroxylases are oxygen-sensing enzymes that regulate cellular responses to hypoxia. Transepithelial Cl(-) secretion, the driving force for fluid secretion, is dependent on O(2) availability for generation of cellular energy. Here, we investigated the role of hydroxylases in regulating epithelial secretion and the potential for targeting these enzymes in treatment of diarrheal disorders. Ion transport was measured as short-circuit current changes across voltage-clamped monolayers of T(84) cells and mouse colon. The antidiarrheal efficacy of dimethyloxallyl glycine (DMOG) was tested in a mouse model of allergic disease. Hydroxylase inhibition with DMOG attenuated Ca(2+)- and cAMP-dependent secretory responses in voltage-clamped T(84) cells to 20.2 +\\/- 2.6 and 38.8 +\\/- 6.7% (n=16; P<\\/=0.001) of those in control cells, respectively. Antisecretory actions of DMOG were time and concentration dependent, being maximal after 18 h of DMOG (1 mM) treatment. DMOG specifically inhibited Na(+)\\/K(+)-ATPase pump activity without altering its expression or membrane localization. In mice, DMOG inhibited agonist-induced secretory responses ex vivo and prevented allergic diarrhea in vivo. In conclusion, hydroxylases are important regulators of epithelial Cl(-) and fluid secretion and present a promising target for development of new drugs to treat transport disorders.

  14. Hydroxylase inhibition attenuates colonic epithelial secretory function and ameliorates experimental diarrhea.

    LENUS (Irish Health Repository)

    Ward, Joseph B J

    2011-02-01

    Hydroxylases are oxygen-sensing enzymes that regulate cellular responses to hypoxia. Transepithelial Cl(-) secretion, the driving force for fluid secretion, is dependent on O(2) availability for generation of cellular energy. Here, we investigated the role of hydroxylases in regulating epithelial secretion and the potential for targeting these enzymes in treatment of diarrheal disorders. Ion transport was measured as short-circuit current changes across voltage-clamped monolayers of T(84) cells and mouse colon. The antidiarrheal efficacy of dimethyloxallyl glycine (DMOG) was tested in a mouse model of allergic disease. Hydroxylase inhibition with DMOG attenuated Ca(2+)- and cAMP-dependent secretory responses in voltage-clamped T(84) cells to 20.2 ± 2.6 and 38.8 ± 6.7% (n=16; P≤0.001) of those in control cells, respectively. Antisecretory actions of DMOG were time and concentration dependent, being maximal after 18 h of DMOG (1 mM) treatment. DMOG specifically inhibited Na(+)\\/K(+)-ATPase pump activity without altering its expression or membrane localization. In mice, DMOG inhibited agonist-induced secretory responses ex vivo and prevented allergic diarrhea in vivo. In conclusion, hydroxylases are important regulators of epithelial Cl(-) and fluid secretion and present a promising target for development of new drugs to treat transport disorders.

  15. Selectivity and affinity determinants for ligand binding to the aromatic amino acid hydroxylases.

    Science.gov (United States)

    Teigen, Knut; McKinney, Jeffrey Alan; Haavik, Jan; Martínez, Aurora

    2007-01-01

    Hydroxylation of the aromatic amino acids phenylalanine, tyrosine and tryptophan is carried out by a family of non-heme iron and tetrahydrobiopterin (BH4) dependent enzymes, i.e. the aromatic amino acid hydroxylases (AAHs). The reactions catalyzed by these enzymes are important for biomedicine and their mutant forms in humans are associated with phenylketonuria (phenylalanine hydroxylase), Parkinson's disease and DOPA-responsive dystonia (tyrosine hydroxylase), and possibly neuropsychiatric and gastrointestinal disorders (tryptophan hydroxylase 1 and 2). We attempt to rationalize current knowledge about substrate and inhibitor specificity based on the three-dimensional structures of the enzymes and their complexes with substrates, cofactors and inhibitors. In addition, further insights on the selectivity and affinity determinants for ligand binding in the AAHs were obtained from molecular interaction field (MIF) analysis. We applied this computational structural approach to a rational analysis of structural differences at the active sites of the enzymes, a strategy that can help in the design of novel selective ligands for each AAH.

  16. Prolyl hydroxylase domain enzymes: important regulators of cancer metabolism

    Directory of Open Access Journals (Sweden)

    Yang M

    2014-08-01

    Full Text Available Ming Yang,1 Huizhong Su,1 Tomoyoshi Soga,2 Kamil R Kranc,3 Patrick J Pollard1 1Cancer Biology and Metabolism Group, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh, UK; 2Institute for Advanced Biosciences, Keio University, Mizukami, Tsuruoka, Yamagata, Japan; 3MRC Centre for Regenerative Medicine, University of Edinburgh, Edinburgh, UK Abstract: The hypoxia-inducible factor (HIF prolyl hydroxylase domain enzymes (PHDs regulate the stability of HIF protein by post-translational hydroxylation of two conserved prolyl residues in its α subunit in an oxygen-dependent manner. Trans-4-prolyl hydroxylation of HIFα under normal oxygen (O2 availability enables its association with the von Hippel-Lindau (VHL tumor suppressor pVHL E3 ligase complex, leading to the degradation of HIFα via the ubiquitin-proteasome pathway. Due to the obligatory requirement of molecular O2 as a co-substrate, the activity of PHDs is inhibited under hypoxic conditions, resulting in stabilized HIFα, which dimerizes with HIFβ and, together with transcriptional co-activators CBP/p300, activates the transcription of its target genes. As a key molecular regulator of adaptive response to hypoxia, HIF plays important roles in multiple cellular processes and its overexpression has been detected in various cancers. The HIF1α isoform in particular has a strong impact on cellular metabolism, most notably by promoting anaerobic, whilst inhibiting O2-dependent, metabolism of glucose. The PHD enzymes also seem to have HIF-independent functions and are subject to regulation by factors other than O2, such as by metabolic status, oxidative stress, and abnormal levels of endogenous metabolites (oncometabolites that have been observed in some types of cancers. In this review, we aim to summarize current understandings of the function and regulation of PHDs in cancer with an emphasis on their roles in metabolism. Keywords: prolyl hydroxylase domain (PHD

  17. A new perspective on beta-sheet structures using vibrational Raman optical activity: From poly(L-lysine) to the prion protein

    DEFF Research Database (Denmark)

    McColl, L.H.; Blanch, E.W.; Gill, A.C.;

    2003-01-01

    The vibrational Raman optical activity (ROA) spectrum of a polypeptide in a model beta-sheet conformation, that of poly(L-lysine), was measured for the first time, and the alpha-helix --> beta-sheet transition monitored as a function of temperature in H2O and D2O. Although no significant populati...

  18. Structure of human phytanoyl-CoA 2-hydroxylase identifies molecular mechanisms of Refsum disease.

    Science.gov (United States)

    McDonough, Michael A; Kavanagh, Kathryn L; Butler, Danica; Searls, Timothy; Oppermann, Udo; Schofield, Christopher J

    2005-12-01

    Refsum disease (RD), a neurological syndrome characterized by adult onset retinitis pigmentosa, anosmia, sensory neuropathy, and phytanic acidaemia, is caused by elevated levels of phytanic acid. Many cases of RD are associated with mutations in phytanoyl-CoA 2-hydroxylase (PAHX), an Fe(II) and 2-oxoglutarate (2OG)-dependent oxygenase that catalyzes the initial alpha-oxidation step in the degradation of phytenic acid in peroxisomes. We describe the x-ray crystallographic structure of PAHX to 2.5 A resolution complexed with Fe(II) and 2OG and predict the molecular consequences of mutations causing RD. Like other 2OG oxygenases, PAHX possesses a double-stranded beta-helix core, which supports three iron binding ligands (His(175), Asp(177), and His(264)); the 2-oxoacid group of 2OG binds to the Fe(II) in a bidentate manner. The manner in which PAHX binds to Fe(II) and 2OG together with the presence of a cysteine residue (Cys(191)) 6.7 A from the Fe(II) and two further histidine residues (His(155) and His(281)) at its active site distinguishes it from that of the other human 2OG oxygenase for which structures are available, factor inhibiting hypoxia-inducible factor. Of the 15 PAHX residues observed to be mutated in RD patients, 11 cluster in two distinct groups around the Fe(II) (Pro(173), His(175), Gln(176), Asp(177), and His(220)) and 2OG binding sites (Trp(193), Glu(197), Ile(199), Gly(204), Asn(269), and Arg(275)). PAHX may be the first of a new subfamily of coenzyme A-binding 2OG oxygenases.

  19. A comparative study of the in vitro antimicrobial activity of tea tree oils s.l. with special reference to the activity of beta-triketones.

    Science.gov (United States)

    Christoph, F; Kaulfers, P M; Stahl-Biskup, E

    2000-08-01

    The in vitro antibacterial and antifungal activities of Australian tea tree oil, cajuput oil, niaouli oil, kanuka oil and manuka oil as well as of a beta-triketone complex isolated from manuka oil were investigated in a constituent-oriented study. The compositions of the oils were analysed by capillary GLC and GLC-MS. The MICs for sixteen different microorganisms were determined applying the broth dilution method. Australian tea tree oil showed the best overall antimicrobial effect. The best inhibitory effects on Gram-positive bacteria and dermatophytes were achieved with manuka oil due to its beta-triketone content.

  20. Native and asialo-Tamm-Horsfall glycoproteins as important ligands for the detection of GalNAc beta 1-->and Gal beta 1-->4GlcNAc active lectins.

    Science.gov (United States)

    Wu, A M; Watkins, W M; Song, S C; Herp, A; Wu, J H

    1995-04-06

    The binding properties of human Tamm-Horsfall Sd(a+) urinary glycoprotein(THGP) and asialo-THGP with various applied lectins was investigated by quantitative precipitin and precipitin inhibition assays. Both glycoproteins completely precipitated Abrus precatorius agglutinin(APA). They also reacted well with Wistaria floribunda (WFA), Glycine max (soybean, SBA), and Ricinus communis agglutinins and precipitated over 78% of the lectin nitrogen added, but reacted poorly or weakly with all alpha-anomeric GalNAc specific lectins, such as Helix pomatia (HPA), Phaseolus lunatus (lima bean, LBL), and Maclura pomifera (MPL) lectins. The glycoprotein-lectin interaction was inhibited by GalNAc beta 1-->, Gal beta 1-->4GlcNAc, or by both. The findings suggest that Sd (a+) THGP and asialo-THGP are among the best water-soluble glycoprotein ligands for GalNAc beta 1-->and Gal beta 1-->4GlcNAc active lectins.

  1. Measurement of the activity of beta emitting gases using an ionisation chamber; Mesure de l'activite des gaz emetteurs beta au moyen d'une chambre d'ionisation

    Energy Technology Data Exchange (ETDEWEB)

    Lebouleux, P. [Commissariat a l' Energie Atomique. Centre d' Etudes Nucleaires de Saclay, 91 - Gif-sur-Yvette (France)

    1962-07-01

    An ionization chamber was developed for measuring directly the activity of a {beta}-emitting gas whatever the gas may be. The following two parameters are defined and determined: p, the average specific ionization produced by a {beta} disintegration, and i, the average {beta} path in the chamber. It was shown, during the determination of i, that the {beta} particles are reflected on the walls of the ionization chamber when the latter are made of a high atomic number material. It was possible to eliminate this effect by constructing an electrode chamber made of graphite. With this chamber a direct measurement can be made of the activity of a gaseous {beta} emitter with a precision of about {+-}10%. Some applications are given of the graphite electrode chamber (calibration of the chambers built industrially and determination of the activation cross section of a gaseous emitter). It was possible to determine the activation cross section of {sup 134}Xe; a value of 0.18 {+-} 0.03 barn was found. (author) [French] Le but de l'etude est de realiser une chambre d'ionisation permettant d'effectuer une mesure directe de l'activite d'un gaz emetteur {beta} quel que soit l'emetteur considere. On definit et l'on determine les deux parametres suivants: p: ionisation specifique moyenne produite par une desintegration {beta}. La determination est effectuee par une methode graphique, i: moyenne des parcours des {beta} dans la chambre. La determination est effectuee experimentalement par introduction dans la chambre d'un gaz radioactif dont on peut calculer l'activite. On a mis en evidence, au cours de la determination de i, la reflexion des particules {beta} sur les parois des chambres d'ionisation lorsque celles-ci sont constituees d'un materiau de numero atomique eleve. La construction d'une chambre a electrodes de graphite nous a permis d'eliminer ce phenomene. Avec cette chambre, on effectue une mesure directe de

  2. Serial studies of serum dopamine-B-hydroxylase and urinary vanillylmandelic and homovanillic acids in neuroblastoma.

    Science.gov (United States)

    Brewster, M A; Berry, D H

    1979-01-01

    Recent reports have suggested that elevations of serum dopamine-B-hydroxylase (DBH) activity may correlate with diagnosis in neuroblastoma patients excreting vanillylmandelic acid (VMA). We have serially studied serum DBH and urinary homovanillic acid (HVA) and VMA excretion during the disease course of five patients with neuroblastoma. DBH activities did not indicate clinical course, therapies, or prognosis. Dilution studies revealed an age-related alteration in DBH effectors and they suggest that these may be different in neuroblastoma.

  3. Purification and antifungal activity of a basic 34 kDa beta-1,3-glucanase from soybean hypocotyls inoculated with Phytophthora sojae f. sp. glycines.

    Science.gov (United States)

    Yi, S Y; Hwang, B K

    1997-06-30

    Inoculation of soybean (Glycine max L. cv. Jangyup) hypocotyls with Phytophthora sojae f. sp. glycines results in a marked accumulation of some pathogenesis-related (PR) proteins. A basic beta-1,3-glucanase (34 kDa) was purified from soybean hypocotyls infected by an incompatible race of P. sojae f. sp. glycines using CM-cellulose cation exchange chromatography and Bio-gel P-60 gel filtration. The purified soybean beta-1,3-glucanase cross-reacted with polyclonal antibody raised against a tomato beta-1,3-glucanase. The activity of beta-1,3-glucanase was much higher in the infected soybean hypocotyls than the healthy ones. The beta-1, 3-glucanase purified from soybean inhibited spore germination and hyphal growth of the chitin-negative fungus P. sojae f. sp. glycines, but did not show any antifungal activity against the chitin-containing fungi Alternaria mali, Colletotrichum gloeosporioides, and Magnaporthe grisea.

  4. Activity of cytisine and its brominated isosteres on recombinant human alpha7, alpha4beta2 and alpha4beta4 nicotinic acetylcholine receptors.

    Science.gov (United States)

    Houlihan, L M; Slater, Y; Guerra, D L; Peng, J H; Kuo, Y P; Lukas, R J; Cassels, B K; Bermudez, I

    2001-09-01

    Effects of cytisine (cy), 3-bromocytisine (3-Br-cy), 5-bromocytisine (5-Br-cy) and 3,5-dibromocytisine (3,5-diBr-cy) on human (h) alpha7-, alpha4beta2- and alpha4beta4 nicotinic acetylcholine (nACh) receptors, expressed in Xenopus oocytes and cell lines, have been investigated. Cy and its bromo-isosteres fully inhibited binding of both [alpha-(125)I]bungarotoxin ([alpha-(125)I]BgTx) to halpha7- and [(3)H]cy to halpha4beta2- or halpha4beta4-nACh receptors. 3-Br-cy was the most potent inhibitor of both [alpha-(125)I]BgTx and [(3)H]cy binding. Cy was less potent than 3-Br-cy, but 5-Br-cy and 3,5-diBr-cy were the least potent inhibitors. Cy and 3-Br-cy were potent full agonists at halpha7-nACh receptors but behaved as partial agonists at halpha4beta2- and halpha4beta4-nACh receptors. 5-Br-cy and 3,5-diBr-cy had low potency and were partial agonists at halpha7- and halpha4beta4-nACh receptors, but they elicited no responses on halpha4beta2-nACh receptors. Cy and 3-Br-cy produced dual dose-response curves (DRC) at both halpha4beta2- and halpha4beta4-nACh receptors, but ACh produced dual DRC only at halpha4beta2-nACh receptors. Low concentrations of cy, 3-Br-cy and 5-Br-cy enhanced ACh responses of oocytes expressing halpha4beta2-nACh receptors, but at high concentrations they inhibited the responses. In contrast, 3,5-diBr-cy only inhibited, in a competitive manner, ACh responses of halpha4beta2-nACh receptors. It is concluded that bromination of the pyridone ring of cy produces marked changes in effects of cy that are manifest as nACh receptor subtype-specific differences in binding affinities and in functional potencies and efficacies.

  5. Chemoprotective activity of boldine: modulation of drug-metabolizing enzymes.

    Science.gov (United States)

    Kubínová, R; Machala, M; Minksová, K; Neca, J; Suchý, V

    2001-03-01

    Possible chemoprotective effects of the naturally occurring alkaloid boldine, a major alkaloid of boldo (Peumus boldus Mol.) leaves and bark, including in vitro modulations of drug-metabolizing enzymes in mouse hepatoma Hepa-1 cell line and mouse hepatic microsomes, were investigated. Boldine manifested inhibition activity on hepatic microsomal CYP1A-dependent 7-ethoxyresorufin O-deethylase and CYP3A-dependent testosterone 6 beta-hydroxylase activities and stimulated glutathione S-transferase activity in Hepa-1 cells. In addition to the known antioxidant activity, boldine could decrease the metabolic activation of other xenobiotics including chemical mutagens.

  6. Differential effects of defined chemical modifications on antigenic and pharmacological activities of scorpion alpha and beta toxins.

    Science.gov (United States)

    el Ayeb, M; Darbon, H; Bahraoui, E M; Vargas, O; Rochat, H

    1986-03-03

    Specific chemical modifications of scorpion alpha and beta toxins have been used to study the involvement of particular residues in both the pharmacological and the antigenic sites of these toxins. Modification by 1,2-cyclohexanedione of arginine-27 of a beta toxin, Centruroides suffusus suffusus toxin II, drastically decrease the antigenic activity without any influence on the pharmacological activity. Conversely, modification by the same reagent of arginine-2 of an alpha toxin, Androctonus australis Hector toxin III, led to a 100-times less pharmacologically potent derivative and did not induce a significant loss of antigenic activity. Excision of the N-terminal pentapeptide of another alpha toxin, Buthus occitanus mardochei toxin III, by pepsin digestion led to a non-toxic derivative retaining full antigenic activity. Thus, the N-terminal part of the conserved hydrophobic surface of the toxin is highly implicated in the pharmacological activity, whereas the region of arginine-27, located in the alpha helix situated on the back surface, opposite the conserved hydrophobic region, is fully implicated in the antigenic activity and is far from the pharmacological site. These results are good arguments in favor of the idea that in scorpion toxins the surfaces implicated in the pharmacological and the antigenic activities do not overlap. Since the antigenic sites are present in highly variable sequence the development of an efficient polyvalent serotherapy is questionable.

  7. Beta Thalassemia

    Science.gov (United States)

    Beta thalassemia is found in people of Mediterranean, Middle Eastern, African, South Asian (Indian, Pakistani, etc.), Southeast Asian and Chinese descent. 1 Beta Thalassemia ßß Normal beta globin genes found on chromosomes ...

  8. Phagocytosis of haemozoin (malarial pigment enhances metalloproteinase-9 activity in human adherent monocytes: Role of IL-1beta and 15-HETE

    Directory of Open Access Journals (Sweden)

    Giribaldi Giuliana

    2008-08-01

    Full Text Available Abstract Background It has been shown previously that human monocytes fed with haemozoin (HZ or trophozoite-parasitized RBCs displayed increased matrix metalloproteinase-9 (MMP-9 enzyme activity and protein/mRNA expression and increased TNF production, and showed higher matrix invasion ability. The present study utilized the same experimental model to analyse the effect of phagocytosis of: HZ, delipidized HZ, beta-haematin (lipid-free synthetic HZ and trophozoites on production of IL-1beta and MMP-9 activity and expression. The second aim was to find out which component of HZ was responsible for the effects. Methods Native HZ freshly isolated from Plasmodium falciparum (Palo Alto strain, Mycoplasma-free, delipidized HZ, beta-haematin (lipid-free synthetic HZ, trophozoites and control meals such as opsonized non-parasitized RBCs and inert latex particles, were fed to human monocytes. The production of IL-1beta by differently fed monocytes, in presence or absence of specific MMP-9 inhibitor or anti-hIL-1beta antibodies, was quantified in supernatants by ELISA. Expression of IL-1beta was analysed by quantitative real-time RT-PCR. MMP-9 activity and protein expression were quantified by gelatin zymography and Western blotting. Results Monocytes fed with HZ or trophozoite-parasitized RBCs generated increased amounts of IL-1beta and enhanced enzyme activity (in cell supernatants and protein/mRNA expression (in cell lysates of monocyte MMP-9. The latter appears to be causally related to enhanced IL-1beta production, as enhancement of both expression and enzyme activity were abrogated by anti-hIL-1beta Abs. Upregulation of IL-1beta and MMP-9 were absent in monocytes fed with beta-haematin or delipidized HZ, indicating a role for HZ-attached or HZ-generated lipid components. 15-HETE (15(S,R-hydroxy-6,8,11,13-eicosatetraenoic acid a potent lipoperoxidation derivative generated by HZ from arachidonic acid via haem-catalysis was identified as one mediator

  9. A proteomics strategy to discover beta-glucosidases from Aspergillus fumigatus with two-dimensional page in-gel activity assay and tandem mass spectrometry.

    Science.gov (United States)

    Kim, Kee-Hong; Brown, Kimberly M; Harris, Paul V; Langston, James A; Cherry, Joel R

    2007-12-01

    Economically competitive production of ethanol from lignocellulosic biomass by enzymatic hydrolysis and fermentation is currently limited, in part, by the relatively high cost and low efficiency of the enzymes required to hydrolyze cellulose to fermentable sugars. Discovery of novel cellulases with greater activity could be a critical step in overcoming this cost barrier. beta-Glucosidase catalyzes the final step in conversion of glucose polymers to glucose. Despite the importance, only a few beta-glucosidases are commercially available, and more efficient ones are clearly needed. We developed a proteomics strategy aiming to discover beta-glucosidases present in the secreted proteome of the cellulose-degrading fungus Aspergillus fumigatus. With the use of partial or complete protein denaturing conditions, the secretory proteome was fractionated in a 2DGE format and beta-glucosidase activity was detected in the gel after infusion with a substrate analogue that fluoresces upon hydrolysis. Fluorescing spots were subjected to tryptic-digestion, and identification as beta-glucosidases was confirmed by tandem mass spectrometry. Two novel beta-glucosidases of A. fumigatus were identified by this in situ activity staining method, and the gene coding for a novel beta-glucosidase ( EAL88289 ) was cloned and heterologously expressed. The expressed beta-glucosidase showed far superior heat stability to the previously characterized beta-glucosidases of Aspergillus niger and Aspergillus oryzae. Improved heat stability is important for development of the next generation of saccharifying enzymes capable of performing fast cellulose hydrolysis reactions at elevated temperatures, thereby lowering the cost of bioethanol production. The in situ activity staining approach described here would be a useful tool for cataloguing and assessing the efficiency of beta-glucosidases in a high throughput fashion.

  10. Regulation of phenylalanine hydroxylase: conformational changes upon phosphorylation detected by H/D exchange and mass spectrometry.

    Science.gov (United States)

    Li, Jun; Fitzpatrick, Paul F

    2013-07-15

    The enzyme phenylalanine hydroxylase catalyzes the hydroxylation of excess phenylalanine in the liver to tyrosine. The enzyme is regulated allosterically by phenylalanine and by phosphorylation of Ser16. Hydrogen/deuterium exchange monitored by mass spectrometry has been used to gain insight into any structural change upon phosphorylation. Peptides in both the catalytic and regulatory domains show increased deuterium incorporation into the phosphorylated protein. Deuterium is incorporated into fewer peptides than when the enzyme is activated by phenylalanine, and the incorporation is slower. This establishes that the conformational change upon phosphorylation of phenylalanine hydroxylase is different from and less extensive than that upon phenylalanine activation.

  11. Differential effect of purified spruce chitinases and beta-1,3-glucanases on the activity of elicitors from ectomycorrhizal fungi.

    Science.gov (United States)

    Salzer, P; Hübner, B; Sirrenberg, A; Hager, A

    1997-07-01

    Two chitinases (EC 3.2.1.14) and two beta-1,3-glucanases (EC 3.2.1.39) were purified from the culture medium of spruce (Picea abines [L.] Karst.) cells to study their role in modifying elicitors, cell walls, growth, and hyphal morphology of ectomycorrhizal fungi. The 36-kD class I chitinase (isoelectric point [pl] 8.0) and the 28-kD chitinase (pl 8.7) decreased the activity of elicitor preparations from Hebeloma crustuliniforme (Bull. ex Fries.) Quél., Amanita muscaria (L.) Pers., and Suillus variegatus (Sw.: Fr.) O.K., as demonstrated by using the elicitor-induced extracellular alkalinization in spruce cells as a test system. In addition, chitinases released monomeric products from the walls of these ectomycorrhizal fungi. The beta-1,3-glucanases (35 kD, pl 3.7 and 3.9), in contrast, had little influence on the activity of the fungal elicitors and released only from walls of A. muscaria some polymeric products. Furthermore, chitinases alone and in combination with beta-1,3-glucanases had no effect on the growth and morphology of the hyphae. Thus, it is suggested that apoplastic chitinases in the root cortex destroy elicitors from the ectomycorrhizal fungi without damaging the fungus. By this mechanism the host plant could attenuate the elicitor signal and adjust its own defense reactions to a level allowing symbiotic interaction.

  12. Measuring phospholipase D activity in insulin-secreting pancreatic beta-cells and insulin-responsive muscle cells and adipocytes.

    Science.gov (United States)

    Cazzolli, Rosanna; Huang, Ping; Teng, Shuzhi; Hughes, William E

    2009-01-01

    Phospholipase D (PLD) is an enzyme producing phosphatidic acid and choline through hydrolysis of phosphatidylcholine. The enzyme has been identified as a member of a variety of signal transduction cascades and as a key regulator of numerous intracellular vesicle trafficking processes. A role for PLD in regulating glucose homeostasis is emerging as the enzyme has recently been identified in events regulating exocytosis of insulin from pancreatic beta-cells and also in insulin-stimulated glucose uptake through controlling GLUT4 vesicle exocytosis in muscle and adipose tissue. We present methodologies for assessing cellular PLD activity in secretagogue-stimulated insulin-secreting pancreatic beta-cells and also insulin-stimulated adipocyte and muscle cells, two of the principal insulin-responsive cell types controlling blood glucose levels.

  13. Conclusion on the peer review of the pesticide risk assessment of the active substance beta-cypermethrin

    Directory of Open Access Journals (Sweden)

    European Food Safety Authority

    2014-06-01

    Full Text Available The conclusions of the European Food Safety Authority (EFSA following the peer review of the initial risk assessments carried out by the competent authority of the rapporteur Member State the United Kingdom, for the pesticide active substance beta-cypermethrin are reported. The context of the peer review was that required by Commission Regulation (EU No 188/2011. The conclusions were reached on the basis of the evaluation of the representative uses of beta-cypermethrin as an insecticide on oilseed rape, wheat and maize. The reliable endpoints concluded as being appropriate for use in regulatory risk assessment, derived from the available studies and literature in the dossier peer reviewed, are presented. Missing information identified as being required by the regulatory framework is listed. Concerns are identified as regards the risk to aquatic organisms, bees and non-target arthropods.

  14. Identification of bacteria with beta-galactosidase activity in faeces from lactase non-persistent subjects

    NARCIS (Netherlands)

    Tao, H; Priebe, MG; Vonk, RJ; Welling, GW

    2005-01-01

    Previous studies suggest that, besides the maldigestion of lactose in the small intestine, the colonic processing of lactose might play a role in lactose intolerance. beta-Galactosidase is the bacterial enzyme which catalyzes the first step of lactose fermentation in the colon. We propose a practica

  15. A novel beta-lactamase activity from a penicillin-binding protein of Treponema pallidum and why syphilis is still treatable with penicillin.

    Science.gov (United States)

    Cha, Joo Young; Ishiwata, Akihiro; Mobashery, Shahriar

    2004-04-09

    Treponema pallidum, the causative agent of syphilis, is sensitive to penicillins. Yet, an abundant membrane-bound protein of this organism, Tp47, turns over penicillins. It is shown herein that the turnover process is a hydrolytic reaction that results in the corresponding penicilloates, products that have their beta-lactam bonds hydrolyzed. This is the reaction of beta-lactamases, bona fide resistance enzymes to beta-lactam antibiotics. Remarkably, the x-ray structure of Tp47 bears no resemblance to any other beta-lactamases or the related penicillin-binding proteins. Furthermore, evidence is presented that the reaction of Tp47 takes place in the absence of the zinc ion and does not involve intermediary acyl enzyme species. Hence, the beta-lactamase activity of Tp47 is the fifth known mechanism for turnover of beta-lactam antibiotics. Tp47 also exhibits a penicillin binding reaction, in the process of which the enzyme is covalently modified in the active site. The two reactions take place in two different active sites, and the events of the beta-lactamase activity are over 2,000-fold more rapid than the penicillin binding reaction. The level of beta-lactamase activity is high and is held back only by a strong product-inhibition component to the catalytic process. If natural selection would result in a mutant variant of Tp47 that overcomes product inhibition for the beta-lactamase activity, a novel bona fide resistance to penicillins will emerge in Treponema, which will be a disconcerting clinical development. The physiological functions of Tp47 are not known, but it is likely that this is at least a bifunctional enzyme involved in the processing of the Treponema peptidoglycan as a substrate.

  16. Design of a Quality Control Program for the Measurement of Gross Alpha and Gross Beta Activities (LMPR-CIEMAT); Diseno del Control de Calidad de las Medidas de Actividad Alfa-Beta Total (LMPR-CIEMAT)

    Energy Technology Data Exchange (ETDEWEB)

    Alvarez, A.; Yague, L.; Gasco, C.; Navarro, N.; Higueras, E.; Noguerales, C.

    2010-10-21

    In accordance with international standards, general requirements for testing laboratories have to include a quality system for planning, implementing, and assessing the work performed by the organization and for carrying out required quality assurance and quality control. The purpose of internal laboratory quality control is to monitor performance, identify problems, and initiate corrective actions. This report describes the internal quality control to monitor the gross alpha and beta activities determination. Identification of specific performance indicators, the principles that govern their use and statistical means of evaluation are explained. Finally, calculation of alpha and beta specific activities, uncertainties and detection limits are performed. (Author) 10 refs.

  17. Enzymic synthesis of alpha- and beta-D-glucosides of 1-deoxynojirimycin and their glycosidase inhibitory activities.

    Science.gov (United States)

    Asano, N; Oseki, K; Kaneko, E; Matsui, K

    1994-05-20

    1-Deoxynojirimycin (1) is a potent inhibitor of mammalian and rice alpha-glucosidase. Several glucosides of 1 were synthesized by use of the native and immobilized enzyme and their effect on various enzymes was investigated. Transglucosylation reactions using rice alpha-glucosidase, yeast alpha- and beta-glucosidases purified from Rhodotorula lactosa were performed with maltose or cellobiose as a glucose donor and N-(benzyloxycarbonyl)-1-deoxynojirimycin (2) as an acceptor. The transglucosylation reaction using native rice alpha-glucosidase afforded 3-O-alpha-D-glucopyranosyl-N-(benzyloxycarbonyl)-1-deoxynojirimycin (4), 4-O-alpha-D-glucopyranosyl-N-(benzyloxycarbonyl)-1-deoxynojirimycin (5), and 2-O-alpha-D-glucopyranosyl-N-(benzyloxycarbonyl)-1-deoxynojirimycin (3) in yields of 40, 13, and 2%, respectively, after 30 min. The transglucosylation reaction using immobilized rice alpha-glucosidase was similar to that using the native enzyme. In the system using native yeast alpha-glucosidase, 3, 5, and 4 were formed in yields of 34, 13, and 6%, respectively, after 15 h. The immobilization of yeast alpha-glucosidase caused a significant decrease in transglucosylation activity. Yeast beta-glucosidase showed a high transglucosylation activity and incubation with the reaction system afforded 2-O-beta-D-glucopyranosyl-N-(benzyloxycarbonyl)-1-deoxynojirimycin (6) and 4-O-beta-D-glucopyranosyl-N-(benzyloxycarbonyl)-1-deoxynojirimycin (7) in yields of 69 and 3%, respectively, after 3 h. The transglucosylation reaction using immobilized yeast beta-glucosidase preferentially afforded 6 in a yield of 73% after 3 h. After removal of N-benzyloxycarbonyl group from the product glucosides, their glycosidase inhibitory activities were measured. 3-O-alpha-D-Glucopyranosyl-1-deoxynojirimycin (9) retained the potent inhibition of 1 against rat intestinal sucrase activity and was more effective than 1 against rice alpha-glucosidase. 4-O-alpha-D-Glucopyranosyl-1-deoxynojirimycin (10

  18. Antiproliferative, anti-aromatase, anti-17beta-HSD and antioxidant activities of lignans isolated from Myristica argentea.

    Science.gov (United States)

    Filleur, F; Le Bail, J C; Duroux, J L; Simon, A; Chulia, A J

    2001-11-01

    Four lignans were isolated from the petrol extract of Myristica argentea mace (Myristicaceae) and their structures were elucidated by means of NMR and mass spectrometry. Although they have been previously described, NMR data are only available for threo-austrobailignan-5, which has been isolated only once, and is incomplete. Three of them, erythro-austrobailignan-6, meso-dihydroguaiaretic acid and nectandrin-B, exert an antiproliferative effect on MCF-7 cells as well as antioxidant activity on the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical, but not the threo-austrobailignan-5. Nectandrin-B also possesses anti-17beta-hydroxysteroid dehydrogenase and anti-aromatase activities.

  19. Activated endothelial interleukin-1beta, -6, and -8 concentrations and intercellular adhesion molecule-1 expression are attenuated by lidocaine.

    LENUS (Irish Health Repository)

    Lan, Wei

    2012-02-03

    Endothelial cells play a key role in ischemia reperfusion injury. We investigated the effects of lidocaine on activated human umbilical vein endothelial cell (HUVEC) interleukin (IL)-1beta, IL-6, and IL-8 concentrations and intercellular adhesion molecule-1 (ICAM-1) expression. HUVECs were pretreated with different concentrations of lidocaine (0 to 0.5 mg\\/mL) for 60 min, thereafter tumor necrosis factor-alpha was added at a concentration of 2.5 ng\\/mL and the cells incubated for 4 h. Supernatants were harvested, and cytokine concentrations were analyzed by enzyme-linked immunosorbent assay. Endothelial ICAM-1 expression was analyzed by using flow cytometry. Differences were assessed using analysis of variance and post hoc unpaired Student\\'s t-test where appropriate. Lidocaine (0.5 mg\\/mL) decreased IL-1beta (1.89 +\\/- 0.11 versus 4.16 +\\/- 1.27 pg\\/mL; P = 0.009), IL-6 (65.5 +\\/- 5.14 versus 162 +\\/- 11.5 pg\\/mL; P < 0.001), and IL-8 (3869 +\\/- 785 versus 14,961 +\\/- 406 pg\\/mL; P < 0.001) concentrations compared with the control. IL-1beta, IL-6, and IL-8 concentrations in HUVECs treated with clinically relevant plasma concentrations of lidocaine (0.005 mg\\/mL) were similar to control. ICAM-1 expression on lidocaine-treated (0.05 mg\\/mL) HUVECs was less than on controls (198 +\\/- 52.7 versus 298 +\\/- 50.3; Mean Channel Fluorescence; P < 0.001). Activated endothelial IL-1beta, IL-6, and IL-8 concentrations and ICAM-1 expression are attenuated only by lidocaine at concentrations larger than clinically relevant concentrations.

  20. Phenylalanine hydroxylase (PAH) from the lower eukaryote Leishmania major.

    Science.gov (United States)

    Lye, Lon-Fye; Kang, Song Ok; Nosanchuk, Joshua D; Casadevall, Arturo; Beverley, Stephen M

    2011-01-01

    Aromatic amino acid hydroxylases (AAAH) typically use tetrahydrobiopterin (H(4)B) as the cofactor. The protozoan parasite Leishmania major requires biopterin for growth and expresses strong salvage and regeneration systems to maintain H(4)B levels. Here we explored the consequences of genetic manipulation of the sole L. major phenylalanine hydroxylase (PAH) to explore whether it could account for the Leishmania H(4)B requirement. L. major PAH resembles AAAHs of other organisms, bearing eukaryotic-type domain organization, and conservation of key catalytic residues including those implicated in pteridine binding. A pah(-) null mutant and an episomal complemented overexpressing derivative (pah-/+PAH) were readily obtained, and metabolic labeling studies established that PAH was required to hydroxylate Phe to Tyr. Neither WT nor overexpressing lines were able to hydroxylate radiolabeled tyrosine or tryptophan, nor to synthesize catecholamines. WT but not pah(-) parasites showed reactivity with an antibody to melanin when grown with l-3,4-dihydroxyphenylalanine (L-DOPA), although the reactive product is unlikely to be melanin sensu strictu. WT was auxotrophic for Phe, Trp and Tyr, suggesting that PAH activity was insufficient to meet normal Tyr requirements. However, pah(-) showed an increased sensitivity to Tyr deprivation, while the pah(-)/+PAH overexpressor showed increased survival and could be adapted to grow well without added Tyr. pah(-) showed no alterations in H(4)B-dependent differentiation, as established by in vitro metacyclogenesis, or survival in mouse or macrophage infections. Thus Leishmania PAH may mitigate but not alleviate Tyr auxotrophy, but plays no essential role in the steps of the parasite infectious cycle. These findings suggest PAH is unlikely to explain the Leishmania requirement for biopterin.

  1. Rhodocytin (aggretin) activates platelets lacking alpha(2)beta(1) integrin, glycoprotein VI, and the ligand-binding domain of glycoprotein Ibalpha

    DEFF Research Database (Denmark)

    Bergmeier, W; Bouvard, D; Eble, J A

    2001-01-01

    Although alpha(2)beta(1) integrin (glycoprotein Ia/IIa) has been established as a platelet collagen receptor, its role in collagen-induced platelet activation has been controversial. Recently, it has been demonstrated that rhodocytin (also termed aggretin), a snake venom toxin purified from...... that collagen may activate platelets by a similar mechanism. In contrast to these findings, we provided evidence that rhodocytin does not bind to alpha(2)beta(1) integrin. Here we show that the Cre/loxP-mediated loss of beta(1) integrin on mouse platelets has no effect on rhodocytin-induced platelet activation...... lacking both alpha(2)beta(1) integrin and the activating collagen receptor GPVI responded normally to rhodocytin. Finally, even after additional proteolytic removal of the 45-kDa N-terminal domain of GPIbalpha rhodocytin induced aggregation of these platelets. These results demonstrate that rhodocytin...

  2. Antibacterial Activity of Some Plant Extracts Against Extended- Spectrum Beta-Lactamase Producing Escherichia coli Isolates

    Science.gov (United States)

    Saeidi, Saeide; Amini Boroujeni, Negar; Ahmadi, Hassan; Hassanshahian, Mehdi

    2015-01-01

    Background: The extended-spectrum beta-lactamase (ESBL) -producing Escherichia coli isolates make many serious infections, especially urinary tract infections. Objectives: The purpose of this study was to determine the antibacterial activities of some natural plant extracts against ESBL-producing E. coli isolates, which harbor the TEM gene in urine samples of the patients who have urinary tract infections. Materials and Methods: Evaluation has to be exactly determined for both methods of disk diffusion test and polymerase chain reaction (PCR), separately. We evaluated 120 strains of E. coli isolates from the urine culture of the patients in Boo-Ali Hospital (Zahedan, south-eastern Iran) who were suffering from urinary tract infections. The ESBL-producing E. coli isolates were evaluated by disk diffusion test and PCR through TEM gene detection. The minimal inhibitory concentration (MIC) of commonly used antibiotics including ceftazidime, ceftriaxon, amikacin, gentamicin and ciprofloxacin along with the MIC of the alcoholic extract of different natural plants including Myrtus communis L (Myrtaceae), Amaranthus retraflexus (Amaranthaceae), Cyminum cuminum L (Apiaceae), Marrubium vulgare (Laminaceae) and Peganum. harmala (Zygrophyllaceae) against the ESBL-producing E. coli isolates, which harbor the TEM genes, were determined using the microdulition method. Results: Results of this study showed that in disk diffusion method, 80 samples of E. coli produced ESBLs. In PCR method, the TEM gene distribution in the isolated ESBL-producing organisms was 50 (41.6%). Amikacin was the most effective anti-bacterial agent and ciprofloxacin was the least effective against E. coli isolates. All the natural plant extracts mentioned above, especially P. harmala, were effective against the selected isolates of ESBL-producing E. coli. The most frequent ESBL rate producing E. coli isolates (32 out of 50) had MIC of 2.5 mg/mL in ethanol extract of P. harmala. Conclusions: The alcoholic

  3. Hypoxia-inducible Factor Prolyl 4-Hydroxylase Inhibition A TARGET FOR NEUROPROTECTION IN THE CENTRAL NERVOUS SYSTEM*

    Science.gov (United States)

    Siddiq, Ambreena; Ayoub, Issam A.; Chavez, Juan C.; Aminova, Leila; Shah, Sapan; LaManna, Joseph C.; Patton, Stephanie M.; Connor, James R.; Cherny, Robert A.; Volitakis, Irene; Bush, Ashley I.; Langsetmo, Ingrid; Seeley, Todd; Gunzler, Volkmar; Ratan, Rajiv R.

    2008-01-01

    Hypoxia-inducible factor (HIF) prolyl 4-hydroxylases are a family of iron- and 2-oxoglutarate-dependent dioxygenases that negatively regulate the stability of several proteins that have established roles in adaptation to hypoxic or oxidative stress. These proteins include the transcriptional activators HIF-1α and HIF-2α. The ability of the inhibitors of HIF prolyl 4-hydroxylases to stabilize proteins involved in adaptation in neurons and to prevent neuronal injury remains unclear. We reported that structurally diverse low molecular weight or peptide inhibitors of the HIF prolyl 4-hydroxylases stabilize HIF-1α and up-regulate HIF-dependent target genes (e.g. enolase, p21waf1/cip1, vascular endothelial growth factor, or erythropoietin) in embryonic cortical neurons in vitro or in adult rat brains in vivo. We also showed that structurally diverse HIF prolyl 4-hydroxylase inhibitors prevent oxidative death in vitro and ischemic injury in vivo. Taken together these findings identified low molecular weight and peptide HIF prolyl 4-hydroxylase inhibitors as novel neurological therapeutics for stroke as well as other diseases associated with oxidative stress. PMID:16227210

  4. A revised model for AMP-activated protein kinase structure: The alpha-subunit binds to both the beta- and gamma-subunits although there is no direct binding between the beta- and gamma-subunits.

    Science.gov (United States)

    Wong, Kelly A; Lodish, Harvey F

    2006-11-24

    The 5'-AMP-activated protein kinase (AMPK) is a master sensor for cellular metabolic energy state. It is activated by a high AMP/ATP ratio and leads to metabolic changes that conserve energy and utilize alternative cellular fuel sources. The kinase is composed of a heterotrimeric protein complex containing a catalytic alpha-subunit, an AMP-binding gamma-subunit, and a scaffolding beta-subunit thought to bind directly both the alpha- and gamma-subunits. Here, we use coimmunoprecipitation of proteins in transiently transfected cells to show that the alpha2-subunit binds directly not only to the beta-subunit, confirming previous work, but also to the gamma1-subunit. Deletion analysis of the alpha2-subunit reveals that the C-terminal 386-552 residues are sufficient to bind to the beta-subunit. The gamma1-subunit binds directly to the alpha2-subunit at two interaction sites, one within the catalytic domain consisting of alpha2 amino acids 1-312 and a second within residues 386-552. Binding of the alpha2 and the gamma1-subunits was not affected by 400 mum AMP or ATP. Furthermore, we show that the beta-subunit C terminus is essential for binding to the alpha2-subunit but, in contrast to previous work, the beta-subunit does not bind directly to the gamma1-subunit. Taken together, this study presents a new model for AMPK heterotrimer structure where through its C terminus the beta-subunit binds to the alpha-subunit that, in turn, binds to the gamma-subunit. There is no direct interaction between the beta- and gamma-subunits.

  5. Continuous Production of Thermostable beta-Amylase with Clostridium thermosulfurogenes: Effect of Culture Conditions and Metabolite Levels on Enzyme Synthesis and Activity.

    Science.gov (United States)

    Nipkow, A; Shen, G J; Zeikus, J G

    1989-03-01

    A beta-amylase-overproducing mutant of Clostridium thermosulfurogenes was grown in continuous culture on soluble starch to produce thermostable beta-amylase. Enzyme productivity was reasonably stable over periods of weeks to months. The pH and temperature optima for beta-amylase production were pH 6.0 and 60 degrees C, respectively. Enzyme concentration was maximized by increasing biomass concentration by using high substrate concentrations and by maintaining a low growth rate. beta-Amylase concentration reached 90 U ml at a dilution rate of 0.07 h in a 3% starch medium. A further increase in enzyme activity levels was limited by acetic acid inhibition of growth and low beta-amylase productivity at low growth rates.

  6. Preparation of Black Hoof medicinal mushroom Phellinus linteus (Berk. et M.A. Curt.) Teng (Aphyllophoromycetideae) beta-glucan sulfate and in vitro tumor cell growth inhibitory activity.

    Science.gov (United States)

    Bae, In Young; Shin, Ji-Yoon; Lee, Hyeon Gyu

    2011-01-01

    Polysaccharide beta-glucans were extracted from the medicinal mushroom Phellinus linteus (Hymenochaetaceae, Aphyllophoromycetideae) and subjected to sulfation. Chemical modification of the beta-glucan was confirmed by structural analysis, and its biological properties were compared with those of native beta-glucan. The results of Fourier transform infrared spectroscopy and elemental analysis indicated that successive preparation of the sulfated derivative yielded a degree of substitution of 0.47. Nitric oxide production measured by the bronchoalveolar lavage (BAL) experiments increased 1.5-fold after sulfation. In addition, the introduction of sulfate groups into the beta-glucan chains improved in vitro growth inhibitory activity against SNU-C2A cells. Therefore, sulfated beta-glucan extracted from Ph. linteus may be beneficial for immune support due to its incorporation of functional groups into its polymer structure.

  7. An application of LSC method for the measurement of gross alpha and beta activities in spiked water and drinking water samples

    Directory of Open Access Journals (Sweden)

    Çakal Gaye Özgür

    2015-09-01

    Full Text Available In this study, after the pulse shape calibration of a liquid scintillation counting (LSC spectrometer (Quantulus 1220, the effi ciency was determined depending on sample quenching parameters. Then, gross alpha and beta activities in two spiked water samples obtained from International Atomic Energy Agency (IAEA were used for the validation of the ASTM D7283-06 method, which is a standard test method for alpha and beta activity in water by LSC. Later, the drinking water samples (35 tap water and 9 bottled water obtained from different districts of Ankara, Turkey, were measured. The maximum gross alpha activities are measured to be 0.08 Bq/L for tap waters and 0.13 Bq/L for bottled waters, whereas the maximum gross beta activities are found to be 0.18 Bq/L for tap waters and 0.16 Bq/L for bottled waters. These results indicate that these drinking water samples are below the required limits, which are 0.1 Bq/L for alpha emitting radionuclides and 1 Bq/L for beta emitting radionuclides. As a result, gross alpha and beta activities in drinking water of Ankara were determined accurately by this validated LSC method. It is also worth noting that LSC is a rapid and accurate method for the determination of gross alpha and beta activities without requiring a tedious sample preparation.

  8. 24-Hydroxylase in Cancer: Impact on Vitamin D-based Anticancer Therapeutics

    Science.gov (United States)

    Luo, Wei; Hershberger, Pamela A.; Trump, Donald L.; Johnson, Candace S.

    2013-01-01

    The active vitamin D hormone 1,25-dihydroxyvitamin D3 (1,25(OH)2D3) plays a major role in regulating calcium homeostasis and bone mineralization. 1,25(OH)2D3 also modulates cellular proliferation and differentiation in a variety of cell types. 24-hydroxylase, encoded by the CYP24A1 gene, is the key enzyme which converts 1,25(OH)2D3 to less active calcitroic acid. Nearly all cell types express 24-hydroxylase, the highest activity being observed in the kidney. There is increasing evidence linking the incidence and prognosis of certain cancers to low serum 25 (OH)D3 levels and high expression of vitamin D 24-hydroxylase supporting the idea that elevated CYP24A1 expression may stimulate degradation of vitamin D metabolites including 25-(OH)D3 and 1,25(OH)2D3. The over expression of CYP24A1 in cancer cells may be a factor affecting 1,25(OH)2D3 bioavailability and anti-proliferative activity pre-clinically and clinically. The combination of 1,25(OH)2D3 with CYP24A1 inhibitors enhances 1,25(OH)2D3 mediated signaling and anti-proliferative effects and may be useful in overcoming effects of aberrant CYP24 expression. PMID:23059474

  9. Inhibition of phosphorylated tyrosine hydroxylase attenuates ethanol-induced hyperactivity in adult zebrafish (Danio rerio).

    Science.gov (United States)

    Nowicki, Magda; Tran, Steven; Chatterjee, Diptendu; Gerlai, Robert

    2015-11-01

    Zebrafish have been successfully employed in the study of the behavioural and biological effects of ethanol. Like in mammals, low to moderate doses of ethanol induce motor hyperactivity in zebrafish, an effect that has been attributed to the activation of the dopaminergic system. Acute ethanol exposure increases dopamine (DA) in the zebrafish brain, and it has been suggested that tyrosine hydroxylase, the rate-limiting enzyme of DA synthesis, may be activated in response to ethanol via phosphorylation. The current study employed tetrahydropapaveroline (THP), a selective inhibitor of phosphorylated tyrosine hydroxylase, for the first time, in zebrafish. We treated zebrafish with a THP dose that did not alter baseline motor responses to examine whether it can attenuate or abolish the effects of acute exposure to alcohol (ethanol) on motor activity, on levels of DA, and on levels of dopamine's metabolite 3,4-dihydroxyphenylacetic acid (DOPAC). We found that 60-minute exposure to 1% alcohol induced motor hyperactivity and an increase in brain DA. Both of these effects were attenuated by pre-treatment with THP. However, no differences in DOPAC levels were found among the treatment groups. These findings suggest that tyrosine hydroxylase is activated via phosphorylation to increase DA synthesis during alcohol exposure in zebrafish, and this partially mediates alcohol's locomotor stimulant effects. Future studies will investigate other potential candidates in the molecular pathway to further decipher the neurobiological mechanism that underlies the stimulatory properties of this popular psychoactive drug.

  10. Xalpha-DVM investigation of double water molecule interactions with active sites of alpha- and beta-subunits of hemoglobin

    Science.gov (United States)

    Yuryeva, Elmira I.

    In this work, the results of Xalpha-discrete variation method calculations of the electronic structure and interatomic parameters of chemical bonding between iron (II) and oxygen molecule with and without extra electrons and protons in active site (AS) of alpha- and beta-subunits of oxyhemoglobin are presented. The Skulachev model of O2 molecule existing in respiration medium in the 2H2O form was used. The introduction of extra electrons does not change considerably the interaction of the iron atom with the O2 oxygen molecule, but strengthens the repulsion in the Fe bond N bonds. In this case, the estimated effective charge of the iron atom is +1.8/1.5e for AS of alpha-/beta-subunits of oxyhemoglobin, and the magnetic moment of iron atoms becomes zero. The deoxygenation effect of the AS of the alpha- and beta-subunits of oxyhemoglobin is due to the ability of extra protons to break down covalent attraction between the iron atom and the nearest oxygen atom and also to weakening of the repulsive component of the covalent Fe bond N interactions.

  11. The role of 14-3-3{beta} in transcriptional activation of estrogen receptor {alpha} and its involvement in proliferation of breast cancer cells

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Yoonseo; Kim, Hyungjin; Jang, Sung-Wuk [School of Life Sciences and Biotechnology, Korea University, Seoul 136-701 (Korea, Republic of); Ko, Jesang, E-mail: jesangko@korea.ac.kr [School of Life Sciences and Biotechnology, Korea University, Seoul 136-701 (Korea, Republic of)

    2011-10-14

    Highlights: {yields} 14-3-3{beta} interacts with ER{alpha} and the interaction is Akt-dependent. {yields} 14-3-3{beta} regulates the transcriptional activity of ER{alpha} in a ligand-dependent manner. {yields} 14-3-3{beta} increases expressions of ER{alpha} target genes. {yields} 14-3-3{beta} increases breast cancer cell proliferation. -- Abstract: The estrogen receptor (ER) functions as a transcription factor that mediates the effects of estrogen. ER{alpha}, which plays a crucial role in the development and progression of breast cancer, is activated by estrogen binding, leading to receptor phosphorylation, dimerization, and recruitment of co-activators and chaperons to the estrogen-bound receptor complex. The 14-3-3 proteins bind to target proteins via phosphorylation and influence many cellular events by altering their subcellular localization or acting as a chaperone. However, regulation of ER{alpha} expression and transactivation by the 14-3-3 proteins has not been reported. We demonstrate that 14-3-3{beta} functions as a positive regulator of ER{alpha} through a direct protein-protein interaction in an estrogen-dependent manner. Ectopic expression of 14-3-3{beta} stimulated ER{alpha}-mediated transcriptional activity in MCF-7 breast cancer cells. Enhanced ER{alpha} transcriptional activity due to 14-3-3{beta} increased the expressions of the endogenous ER{alpha} target genes, leading to proliferation of breast cancer cells. We suggest that 14-3-3{beta} has oncogenic potential in breast cancer via binding to ER{alpha} and activation of the transcriptional activity of ER{alpha}.

  12. Lycopene and other carotenoids inhibit estrogenic activity of 17beta-estradiol and genistein in cancer cells.

    Science.gov (United States)

    Hirsch, Keren; Atzmon, Andrea; Danilenko, Michael; Levy, Joseph; Sharoni, Yoav

    2007-08-01

    Epidemiological evidence suggests that carotenoids prevent several types of cancer, including mammary and endometrial cancers. On the other hand, such studies have also shown that estrogens are the most important risk factors for these cancer types. Genistein, the phytoestrogen mainly found in soy, also shows significant estrogenic activity when tested at concentrations found in human blood. The aim of this study was to determine whether carotenoids inhibit signaling of steroidal estrogen and phytoestrogen which could explain their cancer preventive activity. Similar to the known effect of 17beta-estradiol (E(2)), treatment of breast (T47D and MCF-7) and endometrial (ECC-1) cancer cells with phytoestrogens induced cell proliferation, cell-cycle progression and transactivation of the estrogen response element (ERE). However, each of the tested carotenoids (lycopene, phytoene, phytofluene, and beta-carotene) inhibited cancer cell proliferation induced by either E(2) or genistein. The inhibition of cell growth by lycopene was accompanied by slow down of cell-cycle progression from G1 to S phase. Moreover, the carotenoids inhibited estrogen-induced transactivation of ERE that was mediated by both estrogen receptors (ERs) ERalpha and ERbeta. The possibility that this inhibition results from competition of carotenoid-activated transcription systems on a limited pool of shared coactivators with the ERE transcription system was tested. Although cotransfection of breast and endometrial cancer cells with four different coactivators (SRC-1, SRC-2, SRC-3, and DRIP) strongly stimulated ERE reporter gene activity, it did not oppose the inhibitory effect of carotenoids. These results suggest that dietary carotenoids inhibit estrogen signaling of both 17beta-estradiol and genistein, and attenuate their deleterious effect in hormone-dependent malignancies.

  13. Unresponsiveness to tetrahydrobiopterin of phenylalanine hydroxylase deficiency.

    Science.gov (United States)

    Ponzone, Alberto; Porta, Francesco; Mussa, Alessandro; Alluto, Alessandra; Ferraris, Silvio; Spada, Marco

    2010-05-01

    Conflicting results have been reported concerning the efficacy of tetrahydrobiopterin (BH4), the cofactor of phenylalanine hydroxylase, for reducing phenylalanine (Phe) concentration in phenylketonuria (PKU). We aimed to test quantitatively the effects of BH4 in PKU patients. Seven fully characterized patients were selected among a population of 130 PKU subjects as harboring PKU mutations predicted as BH4 responsive and previously considered responsive to a cofactor challenge. They received a simple Phe (100 mg/kg) and 2 combined Phe (100 mg/kg) and BH4 (20 mg/kg) oral loading tests. Cofactor was administered either before or after the amino acid. The concentrations of Phe, tyrosine (Tyr), and biopterin were measured over 24 hours after loading. The comparative analysis of the loading tests showed that in all patients plasma Phe concentrations peaked within 3 hours, and fell within 24 hours by about 50% in benign, 20% in mild, and 15% in severe phenylalanine hydroxylase deficiency regardless of BH4 administration. A consistent or moderate increase of plasma Tyr, again independent of the cofactor challenge, was observed only in the less severe forms of PAH deficiency. Mean blood biopterin concentration increased 6 times after simple Phe and 34 to 39 times after combined loading tests. The administration of BH4 does not alter Phe and Tyr metabolism in PKU patients. The clearance of plasma Phe after oral loading and, as well as Tyr production, is not related to cofactor challenge but to patient's phenotype. The assessment of BH4 responsiveness by the methods so far used is not reliable, and the occurrence of BH4-responsive forms of PKU still has to be definitely proven.

  14. An additional substrate binding site in a bacterial phenylalanine hydroxylase.

    Science.gov (United States)

    Ronau, Judith A; Paul, Lake N; Fuchs, Julian E; Corn, Isaac R; Wagner, Kyle T; Liedl, Klaus R; Abu-Omar, Mahdi M; Das, Chittaranjan

    2013-09-01

    Phenylalanine hydroxylase (PAH) is a non-heme iron enzyme that catalyzes oxidation of phenylalanine to tyrosine, a reaction that must be kept under tight regulatory control. Mammalian PAH has a regulatory domain in which binding of the substrate leads to allosteric activation of the enzyme. However, the existence of PAH regulation in evolutionarily distant organisms, for example some bacteria in which it occurs, has so far been underappreciated. In an attempt to crystallographically characterize substrate binding by PAH from Chromobacterium violaceum, a single-domain monomeric enzyme, electron density for phenylalanine was observed at a distal site 15.7 Å from the active site. Isothermal titration calorimetry (ITC) experiments revealed a dissociation constant of 24 ± 1.1 μM for phenylalanine. Under the same conditions, ITC revealed no detectable binding for alanine, tyrosine, or isoleucine, indicating the distal site may be selective for phenylalanine. Point mutations of amino acid residues in the distal site that contact phenylalanine (F258A, Y155A, T254A) led to impaired binding, consistent with the presence of distal site binding in solution. Although kinetic analysis revealed that the distal site mutants suffer discernible loss of their catalytic activity, X-ray crystallographic analysis of Y155A and F258A, the two mutants with the most noticeable decrease in activity, revealed no discernible change in the structure of their active sites, suggesting that the effect of distal binding may result from protein dynamics in solution.

  15. Effect of dietary fiber on the induction of colorectal tumors and fecal beta-glucuronidase activity in the rat.

    Science.gov (United States)

    Bauer, H G; Asp, N G; Oste, R; Dahlqvist, A; Fredlund, P E

    1979-09-01

    The purpose of the present study was to investigate whether three different types of dietary fiber, wheat bran, carrot fiber, and citrus pectin, influenced the induction of colorectal tumors produced by 1,2-dimethylhydrazine in rats. In all groups, the tumor yield was high (87 to 97%). In the wheat bran and carrot fiber groups, the incidence of colorectal tumors was not significantly different from that of the group fed on the fiber-free basic diet. The citrus pectin group, however, had a significantly higher incidence of colorectal tumors (p less than 0.001). An increased number of auditory duct tumors was also noted in this group. In a separate experiment, dietary pectin induced a 10-fold increase in fecal beta-glucuronidase activity but did not alter this activity in the bowel wall. It has been suggested that dietary fiber protects against the induction of colorectal tumors, but this was not the case in the experiment. It is possible that the high tumor yield made the demonstration of a weak protective effect of wheat bran impossible. The reason for the increased occurrence of tumors in the citrus pectin group is obscure and will be subjected to further investigation. Fecal beta-glucuronidase activity might be one factor of importance in the activation of the carcinogen.

  16. Wound healing activity and docking of glycogen-synthase-kinase-3-beta-protein with isolated triterpenoid lupeol in rats.

    Science.gov (United States)

    Harish, B G; Krishna, V; Santosh Kumar, H S; Khadeer Ahamed, B M; Sharath, R; Kumara Swamy, H M

    2008-09-01

    A triterpene compound lupeol isolated from petroleum ether extract of leaves of Celastrus paniculatus was screened for wound healing activity (8 mg/ml of 0.2% sodium alginate gel) by excision, incision and dead space wound models on Swiss Albino rats (175-225 g). In lupeol treated groups wound healing activity was more significant (17.83+/-0.48) than the standard skin ointment nitrofurazone (18.33+/-0.42). Epithelialization of the incision wound was faster with a high rate of wound contraction (571.50+/-5.07) as compared with the control group. In dead space wound model also the weight of the granulation tissue of the lupeol treated animal was increased indicating increase of collagenation and absence of monocytes. The comparative docking of isolated lupeol molecule and standard drug nitrofurazone to glycogen synthase kinase 3-beta protein by Wnt signaling pathway also supported the wound healing property of lupeol. The activation domain of GSK3-beta consisted of Tyr216, with residues Asn64, Gly65, Ser66, Phe67, Gly68, Val70, Lys85, Leu132, Val135, Asp181 in the active pocket docked with lupeol at the torsional degree of freedom 0.5 units with Lamarckian genetic algorithm showed the inhibition constant of 1.38 x 10(-7). The inhibition constant of nitrofurazone was only 1.35 x 10(-4).

  17. Structural and Functional Analyses of a Glycoside Hydrolase Family 5 Enzyme with an Unexpected [beta]-Fucosidase Activity

    Energy Technology Data Exchange (ETDEWEB)

    Yoshida, Shosuke; Park, David S.; Bae, Brian; Mackie, Roderick; Cann, Isaac K.O.; Nair, Satish K. (UIUC)

    2012-02-15

    We present characterization of PbFucA, a family 5 glycoside hydrolase (GH5) from Prevotella bryantii B{sub 1}4. While GH5 members typically are xylanases, PbFucA shows no activity toward xylan polysaccharides. A screen against a panel of p-nitrophenol coupled sugars identifies PbFucA as a {beta}-D-fucosidase. We also present the 2.2 {angstrom} resolution structure of PbFucA and use structure-based mutational analysis to confirm the role of catalytically essential residues. A comparison of the active sites of PbFucA with those of family 5 and 51 glycosidases reveals that while the essential catalytic framework is identical between these enzymes, the steric contours of the respective active site clefts are distinct and likely account for substrate discrimination. Our results show that members of this cluster of orthologous group (COG) 5520 have {beta}-D-fucosidase activities, despite showing an overall sequence and structural similarity to GH-5 xylanases.

  18. Brain oscillatory activity during motor preparation: Effect of directional uncertainty on beta, but not alpha, frequency band

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    Charidimos eTzagarakis

    2015-07-01

    Full Text Available In time-constraint activities, such as sports, it is advantageous to be prepared to act even before knowing precisely what action will be needed. Here, we studied the relation between neural oscillations during motor preparation and amount of uncertainty about the direction of the upcoming target. Ten right-handed volunteers participated in a cued center-out task. A brief visual cue identified the region of space in which the target would appear. Three cue sizes were used to vary the amount of information about the direction of the upcoming target. The target appeared at a random location within the region indicated by the cue, and the participants moved a joystick-controlled cursor towards it. Time-frequency analyses showed phasic increases of power in low (delta/theta: 30 Hz frequency-bands in relation to the onset of visual stimuli and of the motor response. More importantly in regard to motor preparation, there was a tonic reduction of power in the alpha (8-12 Hz and beta (14-30 Hz bands during the period between cue presentation and target onset. During motor preparation, the main source of change of power of the alpha band was localized over the contralateral sensorimotor region and both parietal cortices, whereas for the beta-band the main source was the contralateral sensorimotor region. During cue presentation, the reduction of power of the alpha-band in the occipital lobe showed a brief differentiation of condition: the wider the visual cue, the more the power of the alpha-band decreased. However during motor preparation, only the power of the beta-band was dependent on directional uncertainty: the less the directional uncertainty, the more the power of the beta-band decreased. In conclusion, the results indicate that the power in the alpha-band is associated briefly with cue size, but is otherwise an undifferentiated indication of neural activation, whereas the power of the beta-band reflects the level of motor preparation.

  19. The Effect of Glutaraldehyde Cross-Linking on the Enzyme Activity of Immobilized &beta-Galactosidase on Chitosan Bead

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    He Chen

    2013-07-01

    Full Text Available The effect of glutaraldehyde solution concentration, cross-linking time, cross-linking pH and cross-linking temperature on the enzyme activity of the immobilized &beta-galactosidase on Chitosan beads were studied. The enzyme activity was measured after immobilized by detecting the absorbance value at 420 nm.The results were as follows: the immobilized enzyme activity reached the maximum when the concentration of glutaraldehyde solution was 0.3%.The immobilized enzyme had optimal cross-linking time of 3h, optimal cross-linking pH of 6.5, optimal cross-linking temperature of 25°C, under these conditions, the immobilized enzyme activity reached 101, 96, 90 U/g, respectively.

  20. The tissue plasminogen activator-plasminogen proteolytic cascade accelerates amyloid-beta (Abeta) degradation and inhibits Abeta-induced neurodegeneration.

    Science.gov (United States)

    Melchor, Jerry P; Pawlak, Robert; Strickland, Sidney

    2003-10-01

    Accumulation of the amyloid-beta (Abeta) peptide depends on both its generation and clearance. To better define clearance pathways, we have evaluated the role of the tissue plasminogen activator (tPA)-plasmin system in Abeta degradation in vivo. In two different mouse models of Alzheimer's disease, chronically elevated Abeta peptide in the brain correlates with the upregulation of plasminogen activator inhibitor-1 (PAI-1) and inhibition of the tPA-plasmin system. In addition, Abeta injected into the hippocampus of mice lacking either tPA or plasminogen persists, inducing PAI-1 expression and causing activation of microglial cells and neuronal damage. Conversely, Abeta injected into wild-type mice is rapidly cleared and does not cause neuronal degeneration. Thus, the tPA-plasmin proteolytic cascade aids in the clearance of Abeta, and reduced activity of this system may contribute to the progression of Alzheimer's disease.

  1. Inhibition of phosphoinositide 3-kinase enhances TRIF-dependent NF-kappa B activation and IFN-beta synthesis downstream of Toll-like receptor 3 and 4.

    Science.gov (United States)

    Aksoy, Ezra; Vanden Berghe, Wim; Detienne, Sophie; Amraoui, Zoulikha; Fitzgerald, Kathrine A; Haegeman, Guy; Goldman, Michel; Willems, Fabienne

    2005-07-01

    Phosphoinositide 3-kinases (PI3K) are known to regulate Toll-like receptor (TLR)-mediated inflammatory responses, but their impact on the different pathways of TLR signaling remains to be clarified. Here, we investigated the consequences of pharmacological inhibition of PI3K on Toll-IL-1 receptor domain-containing adapter-inducing IFN-beta (TRIF)-dependent signaling, which induces IFN-beta gene expression downstream of TLR3 and TLR4. First, treatment of monocyte-derived dendritic cells (DC) with wortmannin or LY294002 was found to enhance IFN-beta expression upon TLR3 or TLR4 engagement. In the same models of DC activation, PI3K inhibition increased DNA-binding activity of NF-kappaB, but not interferon response factor (IRF)-3, the key transcription factors required for TLR-mediated IFN-beta synthesis. In parallel, wortmannin-treated DC exhibited enhanced levels of IkappaB kinase (IKK)-alpha/beta phosphorylation and IkappaB-alpha degradation with a concomitant increase in NF-kappaB nuclear translocation. Experiments carried out in HEK 293T cells stably expressing TLR3 or TLR4 confirmed that inhibition of PI3K activity enhances NF-kappaB-dependent promoters as well as IFN-beta promoter activities without interfering with transcription at the positive regulatory domain III-I. Furthermore, wortmannin enhanced NF-kappaB activity induced by TRIF overexpression in HEK 293T cells, while overexpression of catalytically active PI3K selectively attenuated TRIF-mediated NF-kappaB transcriptional activity. Finally, in co-immunoprecipitation experiments, we showed that PI3K physically interacted with TRIF. We conclude that inhibition of PI3K activity enhances TRIF-dependent NF-kappaB activity, and thereby increases IFN-beta synthesis elicited by TLR3 or TLR4 ligands.

  2. Safrole oxide induces neuronal apoptosis through inhibition of integrin beta4/SOD activity and elevation of ROS/NADPH oxidase activity.

    Science.gov (United States)

    Su, Le; Zhao, BaoXiang; Lv, Xin; Wang, Nan; Zhao, Jing; Zhang, ShangLi; Miao, JunYing

    2007-02-20

    Neuronal apoptosis is a very important event in the development of the central nervous system (CNS), but the underlying mechanisms remain to be elucidated. We have previously shown that safrole oxide, a small molecule, induces integrin beta4 expression and promotes apoptosis in vascular endothelial cells. In this study, the effects of safrole oxide on cell growth and apoptosis have been examined in primary cultures of mouse neurons. Safrole oxide was found to significantly inhibit neuronal cell growth and to induce apoptosis. The inhibitory and apoptotic activities of safrole oxide followed a dose- and time-dependent manner. Interestingly, the expression of integrin beta4 was significantly inhibited with safrole oxide treatment. Furthermore, safrole oxide dramatically increases the level of intracellular reactive oxygen species (ROS) and the activity of NADPH oxidase. Moreover, manganese-dependent superoxide dismutase (MnSOD) activity was decreased significantly with safrole oxide treatment. Our study thus demonstrates that safrole oxide induces neuronal apoptosis through integrin beta4, ROS, NADPH, and MnSOD.

  3. Acetylcholine release in mouse hippocampal CA1 preferentially activates inhibitory-selective interneurons via alpha4 beta2* nicotinic receptor activation

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    L. Andrew Bell

    2015-04-01

    Full Text Available Acetylcholine (ACh release onto nicotinic receptors directly activates subsets of inhibitory interneurons in hippocampal CA1. However, the specific interneurons activated and their effect on the hippocampal network is not completely understood. Therefore, we investigated subsets of hippocampal CA1 interneurons that respond to ACh release through the activation of nicotinic receptors and the potential downstream effects this may have on hippocampal CA1 network function. ACh was optogenetically released in mouse hippocampal slices by expressing the excitatory optogenetic protein oChIEF-tdTomato in medial septum/diagonal band of Broca cholinergic neurons using Cre recombinase-dependent adeno-associated viral mediated transfection. The actions of optogenetically released ACh were assessed on both pyramidal neurons and different interneuron subtypes via whole cell patch clamp methods. Vasoactive intestinal peptide (VIP-expressing interneurons that selectively innervate other interneurons (VIP/IS were excited by ACh through the activation of nicotinic receptors containing alpah4 and beta2 subunits (alpha4 beta2*. ACh release onto VIP/IS was presynaptically inhibited by M2 muscarinic autoreceptors. ACh release produced spontaneous inhibitory postsynaptic current (sIPSC barrages blocked by dihydro-beta-erythroidine in interneurons but not pyramidal neurons. Optogenetic suppression of VIP interneurons did not inhibit these sIPSC barrages suggesting other interneuron-selective interneurons were also excited by 42* nicotinic receptor activation. In contrast, interneurons that innervate pyramidal neuron perisomatic regions were not activated by ACh release onto nicotinic receptors. Therefore, we propose ACh release in CA1 facilitates disinhibition through activation of 42* nicotinic receptors on interneuron-selective interneurons whereas interneurons that innervate pyramidal neurons are less affected by nicotinic receptor activation.

  4. Biphasic effect of IL-1beta on the activity of argininosuccinate synthetase in Caco-2 cells. Involvement of nitric oxide production.

    Science.gov (United States)

    Brasse-Lagnel, Carole; Lavoinne, Alain; Fairand, Alain; Vavasseur, Karine; Deniel, Nicolas; Husson, Annie

    2006-06-01

    The expression of the argininosuccinate synthetase gene (ASS), the limiting enzyme of arginine synthesis, was previously shown to be rapidly induced by a short-term (4 h) exposure to IL-1beta in Caco-2 cells [Biochimie, 2005, 403-409]. The present report shows that, by contrast, a long-term (24 h) exposure to IL-1beta inhibited the ASS activity despite an increase in both specific mRNA level and protein amount, demonstrating a post-translational effect. Concerning the mechanism involved, we demonstrate that the inhibiting effect is linked to the production of nitric oxide (NO) induced by IL-1beta. Indeed, the inhibiting effect of IL-1beta was totally blocked in the presence of l-NMMA, an inhibitor of the inducible nitric oxide synthase, or by culturing the cells in an arginine-deprived medium. Moreover, a decrease in the ASS activity was induced by culturing the cells in the presence of SNAP, a NO donor. Conversely, blocking the action of NO by antioxidant agents, the stimulatory effect of IL-1beta on ASS activity was restored, as measured at 24 h. Finally, such an inhibiting effect of NO on ASS activity may be related, at least in part, to S-nitrosylation of the protein. The physiological relevance of the antagonistic effects of IL-1beta and NO on ASS is discussed.

  5. Human recombinant macrophage inflammatory protein-1 alpha and -beta and monocyte chemotactic and activating factor utilize common and unique receptors on human monocytes.

    Science.gov (United States)

    Wang, J M; Sherry, B; Fivash, M J; Kelvin, D J; Oppenheim, J J

    1993-04-01

    The human macrophage inflammatory proteins-1 alpha and -beta (MIP-1 alpha and -beta), which are also known as LD78 and ACT2, respectively, are distinct but highly related members of the chemoattractant cytokine (chemokine) family. rMIP-1 alpha and -beta labeled with 125I specifically bind to human peripheral blood monocytes, the monocytic cell line THP-1, peripheral blood T cells, and the YT cell line. Steady state binding experiments revealed approximately 3000 high affinity binding sites/cell for MIP-1 alpha on human monocytes and on THP-1 cells, with Kd values of 383 pM and 450 pM, respectively. Human MIP-1 alpha and -beta had nearly identical affinities for the binding sites and each competed equally well for binding. Human monocyte chemotactic and activating factor (MCAF), a member of the same chemokine family, consistently displaced about 25% of human MIP-1 alpha and -beta binding on monocytes but not on YT cells, which did not bind MCAF. On the other hand, human rMIP-1 alpha and -beta partially inhibited binding of radiolabeled MCAF to monocytes. Both MIP-1 alpha and -beta were chemotactic for human monocytes. Preincubation of monocytes with human rMIP-1 alpha or -beta markedly reduced cell migration towards the other cytokine, whereas preincubation with human rMCAF only partially desensitized the monocyte chemotaxis response to human rMIP-1 alpha or -beta. These data suggest the existence of three subtypes of receptors, i.e., one unique receptor shared by MIP-1 alpha and -beta, a second unique receptor for MCAF, and a third species that recognizes both MCAF and MIP-1 peptides.

  6. Measuring the orientation of taurine in the active site of the non-heme Fe(II)/α-ketoglutarate-dependent taurine hydroxylase (TauD) using electron spin echo envelope modulation (ESEEM) spectroscopy.

    Science.gov (United States)

    Casey, Thomas M; Grzyska, Piotr K; Hausinger, Robert P; McCracken, John

    2013-09-12

    The position and orientation of taurine near the non-heme Fe(II) center of the α-ketoglutarate (α-KG)-dependent taurine hydroxylase (TauD) was measured using Electron Spin Echo Envelope Modulation (ESEEM) spectroscopy. TauD solutions containing Fe(II), α-KG, and natural abundance taurine or specifically deuterated taurine were prepared anaerobically and treated with nitric oxide (NO) to make an S = 3/2 {FeNO}(7) complex that is suitable for robust analysis with EPR spectroscopy. Using ratios of ESEEM spectra collected for TauD samples having natural abundance taurine or deuterated taurine, (1)H and (14)N modulations were filtered out of the spectra and interactions with specific deuterons on taurine could be studied separately. The Hamiltonian parameters used to calculate the amplitudes and line shapes of frequency spectra containing isolated deuterium ESEEM were obtained with global optimization algorithms. Additional statistical analysis was performed to validate the interpretation of the optimized parameters. The strongest (2)H hyperfine coupling was to a deuteron on the C1 position of taurine and was characterized by an effective dipolar distance of 3.90 ± 0.25 Å from the {FeNO}(7) paramagnetic center. The principal axes of this C1-(2)H hyperfine coupling and nuclear quadrupole interaction tensors were found to make angles of 26 ± 5 and 52 ± 17°, respectively, with the principal axis of the {FeNO}(7) zero-field splitting tensor. These results are discussed within the context of the orientation of substrate taurine prior to the initiation of hydrogen abstraction.

  7. A novel biological activity of praziquantel requiring voltage-operated Ca2+ channel beta subunits: subversion of flatworm regenerative polarity.

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    Taisaku Nogi

    Full Text Available BACKGROUND: Approximately 200 million people worldwide harbour parasitic flatworm infections that cause schistosomiasis. A single drug-praziquantel (PZQ-has served as the mainstay pharmacotherapy for schistosome infections since the 1980s. However, the relevant in vivo target(s of praziquantel remain undefined. METHODS AND FINDINGS: Here, we provide fresh perspective on the molecular basis of praziquantel efficacy in vivo consequent to the discovery of a remarkable action of PZQ on regeneration in a species of free-living flatworm (Dugesia japonica. Specifically, PZQ caused a robust (100% penetrance and complete duplication of the entire anterior-posterior axis during flatworm regeneration to yield two-headed organisms with duplicated, integrated central nervous and organ systems. Exploiting this phenotype as a readout for proteins impacting praziquantel efficacy, we demonstrate that PZQ-evoked bipolarity was selectively ablated by in vivo RNAi of voltage-operated calcium channel (VOCC beta subunits, but not by knockdown of a VOCC alpha subunit. At higher doses of PZQ, knockdown of VOCC beta subunits also conferred resistance to PZQ in lethality assays. CONCLUSIONS: This study identifies a new biological activity of the antischistosomal drug praziquantel on regenerative polarity in a species of free-living flatworm. Ablation of the bipolar regenerative phenotype evoked by PZQ via in vivo RNAi of VOCC beta subunits provides the first genetic evidence implicating a molecular target crucial for in vivo PZQ activity and supports the 'VOCC hypothesis' of PZQ efficacy. Further, in terms of regenerative biology and Ca(2+ signaling, these data highlight a novel role for voltage-operated Ca(2+ entry in regulating in vivo stem cell differentiation and regenerative patterning.

  8. Lactate-modulated induction of THBS-1 activates transforming growth factor (TGF-beta2 and migration of glioma cells in vitro.

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    Corinna Seliger

    Full Text Available BACKGROUND: An important phenomenon observed in glioma metabolism is increased aerobic glycolysis in tumor cells, which is generally referred to as the Warburg effect. Transforming growth factor (TGF-beta2, which we previously showed to be induced by lactic acid, is a key pathophysiological factor in glioblastoma, leading to increased invasion and severe local immunosuppression after proteolytic cleavage from its latency associated peptide. In this study we tested the hypothesis, that lactate regulates TGF-beta2 expression and glioma cell migration via induction of Thrombospondin-1 (THBS-1, a TGF-beta activating protein. METHODS: Lactate levels were reduced by knockdown of LDH-A using specific small interfering RNA (siRNA and competitive inhibition of LDH-A by sodium oxamate. Knockdown of THBS-1 was performed using specific siRNA. Western Blot, qRT-PCR, and ELISA were used to investigate expression levels of LDH-A, LDH-B, TGF-beta2 and THBS-1. Migration of cells was examined by Spheroid, Scratch and Boyden Chamber assays. RESULTS: Knockdown of LDH-A with subsequent decrease of lactate concentration leads to reduced levels of THBS-1 and TGF-beta2 in glioma cells. Lactate addition increases THBS-1 protein, leading to increased activation of TGF-beta2. Inhibition of THBS-1 reduces TGF-beta2 protein and migration of glioma cells. Addition of synthetic THBS-1 can rescue reduced TGF-beta2 protein levels and glioma cell migration in siLDH-A treated cells. CONCLUSION: We define a regulatory cascade between lactate, THBS-1 and TGF-beta2, leading to enhanced migration of glioma cells. Our results demonstrate a specific interaction between tumor metabolism and migration and provide a better understanding of the mechanisms underlying glioma cell invasion.

  9. Monomer formation and functioning of p hydroxybenzoate hydroxylase in reverse micelles and in dimethylsulfoxide-water mixtures

    NARCIS (Netherlands)

    Kudryashova, E.V.; Visser, A.J.W.G.; Berkel, van W.J.H.

    2008-01-01

    It has previously been postulated that the dimeric form of the flavoprotein p-hydroxybenzoate hydroxylase (PHBH) is important for catalysis. Here it is demonstrated that the monomeric form of PHBH is active. In a water/AOT/isooctane reverse micellar system, the function of the monomeric and dimeric

  10. Vascular endothelial growth factor-induced migration of multiple myeloma cells is associated with beta 1 integrin- and phosphatidylinositol 3-kinase-dependent PKC alpha activation.

    Science.gov (United States)

    Podar, Klaus; Tai, Yu-Tzu; Lin, Boris K; Narsimhan, Radha P; Sattler, Martin; Kijima, Takashi; Salgia, Ravi; Gupta, Deepak; Chauhan, Dharminder; Anderson, Kenneth C

    2002-03-08

    In multiple myeloma (MM), migration is necessary for the homing of tumor cells to bone marrow (BM), for expansion within the BM microenvironment, and for egress into the peripheral blood. In the present study we characterize the role of vascular endothelial growth factor (VEGF) and beta(1) integrin (CD29) in MM cell migration. We show that protein kinase C (PKC) alpha is translocated to the plasma membrane and activated by adhesion of MM cells to fibronectin and VEGF. We identify beta(1) integrin modulating VEGF-triggered MM cell migration on fibronectin. We show that transient enhancement of MM cell adhesion to fibronectin triggered by VEGF is dependent on the activity of both PKC and beta(1) integrin. Moreover, we demonstrate that PKC alpha is constitutively associated with beta(1) integrin. These data are consistent with PKC alpha-dependent exocytosis of activated beta(1) integrin to the plasma membrane, where its increased surface expression mediates binding to fibronectin; conversely, catalytically active PKC alpha-driven internalization of beta(1) integrin results in MM cell de-adhesion. We show that the regulatory subunit of phosphatidylinositol (PI) 3-kinase (p85) is constitutively associated with FMS-like tyrosine kinase-1 (Flt-1). VEGF stimulates activation of PI 3-kinase, and both MM cell adhesion and migration are PI 3-kinase-dependent. Moreover, both VEGF-induced PI 3-kinase activation and beta(1) integrin-mediated binding to fibronectin are required for the recruitment and activation of PKC alpha. Time-lapse phase contrast video microscopy (TLVM) studies confirm the importance of these signaling components in VEGF-triggered MM cell migration on fibronectin.

  11. Brain activation by short-term nicotine exposure in anesthetized wild-type and beta2-nicotinic receptors knockout mice: a BOLD fMRI study

    Energy Technology Data Exchange (ETDEWEB)

    Suarez, S.V.; Changeux, J.P.; Granon, S. [Unite de Neurobiologie Integrative du Systeme Cholinergique, URA CNRS 2182, Institut Pasteur, Departement de Neuroscience, 25 rue du Dr Roux, 75015 Paris (France); Amadon, A.; Giacomini, E.; Le Bihan, D. [Service Hospitalier Frederic Joliot, 4 place du general Leclerc, 91400 Orsay (France); Wiklund, A. [Section of Anaesthesiology and Intensive Care Medicine, Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm (Sweden)

    2009-07-01

    Rationale: The behavioral effects of nicotine and the role of the beta2-containing nicotinic receptors in these behaviors are well documented. However, the behaviors altered by nicotine rely on the functioning on multiple brain circuits where the high-affinity {beta}2-containing nicotinic receptors ({beta}2*nAChRs) are located. Objectives We intend to see which brain circuits are activated when nicotine is given in animals naive for nicotine and whether the {beta}2*nAChRs are needed for its activation of the blood oxygen level dependent (BOLD) signal in all brain areas. Materials and methods: We used functional magnetic resonance imaging (fMRI) to measure the brain activation evoked by nicotine (1 mg/kg delivered at a slow rate for 45 min) in anesthetized C57BL/6J mice and {beta}2 knockout (KO) mice. Results: Acute nicotine injection results in a significant increased activation in anterior frontal, motor, and somatosensory cortices and in the ventral tegmental area and the substantia nigra. Anesthetized mice receiving no nicotine injection exhibited a major decreased activation in all cortical and subcortical structures, likely due to prolonged anesthesia. At a global level, {beta}2 KO mice were not rescued from the globally declining BOLD signal. However, nicotine still activated regions of a meso-cortico-limbic circuit likely via {alpha}7 nicotinic receptors. Conclusions: Acute nicotine exposure compensates for the drop in brain activation due to anesthesia through the meso-cortico-limbic network via the action of nicotine on {beta}2*nAChRs. The developed fMRI method is suitable for comparing responses in wild-type and mutant mice. (authors)

  12. Tyrosine Hydroxylase as a Target for Deltamethrin in the Nigrostriatal Dopaminergic Pathway

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Objective To study the effects of deltamethrin on tyrosine hydroxylase in nigrostriatum of male rats. Methods Sprague-Dawley rats were daily treated with deltamethrin at 6.25 or 12.5 mg/kg body weight by gavage for 10 days. Then HPLC-fluorescence detection was used to analyze the contents of dopamine (DA), 3,4-dihydroxyphenylacetic acid (DOPAC) and homoranillic acid (HVA) in substantial nigra and striatum. The activities of tyrosine hydroxylase (TH) were also detected by HPLC-fluorescence detection. TH mRNA or TH protein levels were measured by RT-PCR and immunohistochemistry method. Results The content of DA in striatum was significantly decreased by the treatments, suggesting an inhibition of DA synthesis by deltamethrin. The contents of DA metabolites DOPAC and HVA increased, indicating increased dopamine turnover. Furthermore, deltamethrin significantly decreased the activity, as well as the mRNA and protein levels of TH.Conclusions These findings reveal a novel aspect of deltamethrin neurotoxicity and suggest tyrosine hydroxylase as a molecular target of deltamethin on dopamine metabolism in the nigrostriatal pathway.

  13. Direct evidence for a phenylalanine site in the regulatory domain of phenylalanine hydroxylase.

    Science.gov (United States)

    Li, Jun; Ilangovan, Udayar; Daubner, S Colette; Hinck, Andrew P; Fitzpatrick, Paul F

    2011-01-15

    The hydroxylation of phenylalanine to tyrosine by the liver enzyme phenylalanine hydroxylase is regulated by the level of phenylalanine. Whether there is a distinct allosteric binding site for phenylalanine outside of the active site has been unclear. The enzyme contains an N-terminal regulatory domain that extends through Thr117. The regulatory domain of rat phenylalanine hydroxylase was expressed in Escherichia coli. The purified protein behaves as a dimer on a gel filtration column. In the presence of phenylalanine, the protein elutes earlier from the column, consistent with a conformational change in the presence of the amino acid. No change in elution is seen in the presence of the non-activating amino acid proline. ¹H-¹⁵N HSQC NMR spectra were obtained of the ¹⁵N-labeled protein alone and in the presence of phenylalanine or proline. A subset of the peaks in the spectrum exhibits chemical shift perturbation in the presence of phenylalanine, consistent with binding of phenylalanine at a specific site. No change in the NMR spectrum is seen in the presence of proline. These results establish that the regulatory domain of phenylalanine hydroxylase can bind phenylalanine, consistent with the presence of an allosteric site for the amino acid.

  14. X-ray structure of a hydroxylase-regulatory protein complex from a hydrocarbon-oxidizing multicomponent monooxygenase, Pseudomonas sp. OX1 phenol hydroxylase.

    Science.gov (United States)

    Sazinsky, Matthew H; Dunten, Pete W; McCormick, Michael S; DiDonato, Alberto; Lippard, Stephen J

    2006-12-26

    Phenol hydroxylase (PH) belongs to a family of bacterial multicomponent monooxygenases (BMMs) with carboxylate-bridged diiron active sites. Included are toluene/o-xylene (ToMO) and soluble methane (sMMO) monooxygenase. PH hydroxylates aromatic compounds, but unlike sMMO, it cannot oxidize alkanes despite having a similar dinuclear iron active site. Important for activity is formation of a complex between the hydroxylase and a regulatory protein component. To address how structural features of BMM hydroxylases and their component complexes may facilitate the catalytic mechanism and choice of substrate, we determined X-ray structures of native and SeMet forms of the PH hydroxylase (PHH) in complex with its regulatory protein (PHM) to 2.3 A resolution. PHM binds in a canyon on one side of the (alphabetagamma)2 PHH dimer, contacting alpha-subunit helices A, E, and F approximately 12 A above the diiron core. The structure of the dinuclear iron center in PHH resembles that of mixed-valent MMOH, suggesting an Fe(II)Fe(III) oxidation state. Helix E, which comprises part of the iron-coordinating four-helix bundle, has more pi-helical character than analogous E helices in MMOH and ToMOH lacking a bound regulatory protein. Consequently, conserved active site Thr and Asn residues translocate to the protein surface, and an approximately 6 A pore opens through the four-helix bundle. Of likely functional significance is a specific hydrogen bond formed between this Asn residue and a conserved Ser side chain on PHM. The PHM protein covers a putative docking site on PHH for the PH reductase, which transfers electrons to the PHH diiron center prior to O2 activation, suggesting that the regulatory component may function to block undesired reduction of oxygenated intermediates during the catalytic cycle. A series of hydrophobic cavities through the PHH alpha-subunit, analogous to those in MMOH, may facilitate movement of the substrate to and/or product from the active site pocket

  15. Gross alpha and beta activity analyses in urine-a routine laboratory method for internal human radioactivity detection.

    Science.gov (United States)

    Chen, Xiaowen; Zhao, Luqian; Qin, Hongran; Zhao, Meijia; Zhou, Yirui; Yang, Shuqiang; Su, Xu; Xu, Xiaohua

    2014-05-01

    The aim of this work was to develop a method to provide rapid results for humans with internal radioactive contamination. The authors hypothesized that valuable information could be obtained from gas proportional counter techniques by screening urine samples from potentially exposed individuals rapidly. Recommended gross alpha and beta activity screening methods generally employ gas proportional counting techniques. Based on International Standards Organization (ISO) methods, improvements were made in the evaporation process to develop a method to provide rapid results, adequate sensitivity, and minimum sample preparation and operator intervention for humans with internal radioactive contamination. The method described by an American National Standards Institute publication was used to calibrate the gas proportional counter, and urine samples from patients with or without radionuclide treatment were measured to validate the method. By improving the evaporation process, the time required to perform the assay was reduced dramatically. Compared with the reference data, the results of the validation samples were very satisfactory with respect to gross-alpha and gross-beta activities. The gas flow proportional counting method described here has the potential for radioactivity monitoring in the body. This method was easy, efficient, and fast, and its application is of great utility in determining whether a sample should be analyzed by a more complicated method, for example radiochemical and/or γ-spectroscopy. In the future, it may be used commonly in medical examination and nuclear emergency treatment.Health Phys. 106(5):000-000; 2014.

  16. Cellular Oxygen Sensing: Crystal Structure of Hypoxia-Inducible Factor Prolyl Hydroxylase (PHD2)

    Energy Technology Data Exchange (ETDEWEB)

    McDonough,M.; Li, V.; Flashman, E.; Chowdhury, R.; Mohr, C.; Lienard, B.; Zondlo, J.; Oldham, N.; Clifton, I.; et al.

    2006-01-01

    Cellular and physiological responses to changes in dioxygen levels in metazoans are mediated via the posttranslational oxidation of hypoxia-inducible transcription factor (HIF). Hydroxylation of conserved prolyl residues in the HIF-{alpha} subunit, catalyzed by HIF prolyl-hydroxylases (PHDs), signals for its proteasomal degradation. The requirement of the PHDs for dioxygen links changes in dioxygen levels with the transcriptional regulation of the gene array that enables the cellular response to chronic hypoxia; the PHDs thus act as an oxygen-sensing component of the HIF system, and their inhibition mimics the hypoxic response. We describe crystal structures of the catalytic domain of human PHD2, an important prolyl-4-hydroxylase in the human hypoxic response in normal cells, in complex with Fe(II) and an inhibitor to 1.7 Angstroms resolution. PHD2 crystallizes as a homotrimer and contains a double-stranded {beta}-helix core fold common to the Fe(II) and 2-oxoglutarate-dependant dioxygenase family, the residues of which are well conserved in the three human PHD enzymes (PHD 1-3). The structure provides insights into the hypoxic response, helps to rationalize a clinically observed mutation leading to familial erythrocytosis, and will aid in the design of PHD selective inhibitors for the treatment of anemia and ischemic disease.

  17. Sesamin modulates tyrosine hydroxylase, superoxide dismutase, catalase, inducible NO synthase and interleukin-6 expression in dopaminergic cells under MPP+-induced oxidative stress.

    Science.gov (United States)

    Lahaie-Collins, Vicky; Bournival, Julie; Plouffe, Marilyn; Carange, Julie; Martinoli, Maria-Grazia

    2008-01-01

    Oxidative stress is regarded as a mediator of nerve cell death in several neurodegenerative disorders, such as Parkinson's disease. Sesamin, a lignan mainly found in sesame oil, is currently under study for its anti-oxidative and possible neuroprotective properties. We used 1-methyl-4-phenyl-pyridine (MPP(+)) ion, the active metabolite of the potent parkinsonism-causing toxin 1-methyl-4-phenyl-1,2,5,6-tetrahydropyridine, to produce oxidative stress and neurodegeneration in neuronal PC12 cells, which express dopamine, as well as neurofilaments. Our results show that picomolar doses of sesamin protected neuronal PC12 cells from MPP(+)-induced cellular death, as revealed by colorimetric measurements and production of reactive oxygen species. We also demonstrated that sesamin acted by rescuing tyrosine hydroxylase levels from MPP(+)-induced depletion. Sesamin, however, did not modulate dopamine transporter levels, and estrogen receptor-alpha and -beta protein expression. By examining several parameters of cell distress, we found that sesamin also elicited a strong increase in superoxide dismutase activity as well as protein expression and decreased catalase activity and the MPP(+) stimulated inducible nitric oxide synthase protein expression, in neuronal PC12 cells. Finally, sesamin possessed significant anti-inflammatory properties, as disclosed by its potential to reduce MPP(+)-induced interleukin-6 mRNA levels in microglia. From these studies, we determined the importance of the lignan sesamin as a neuroprotective molecule and its possible role in complementary and/or preventive therapies of neurodegenerative diseases.

  18. Sesamin Modulates Tyrosine Hydroxylase, Superoxide Dismutase, Catalase, Inducible No Synthase and Interleukin-6 Expression in Dopaminergic Cells Under Mpp+-Induced Oxidative Stress

    Directory of Open Access Journals (Sweden)

    Vicky Lahaie-Collins

    2008-01-01

    Full Text Available Oxidative stress is regarded as a mediator of nerve cell death in several neurodegenerative disorders, such as Parkinson's disease. Sesamin, a lignan mainly found in sesame oil, is currently under study for its anti-oxidative and possible neuroprotective properties. We used 1-methyl-4-phenyl-pyridine (MPP+ ion, the active metabolite of the potent parkinsonism-causing toxin 1-methyl-4-phenyl-1,2,5,6-tetrahydropyridine, to produce oxidative stress and neurodegeneration in neuronal PC12 cells, which express dopamine, as well as neurofilaments. Our results show that picomolar doses of sesamin protected neuronal PC12 cells from MPP+-induced cellular death, as revealed by colorimetric measurements and production of reactive oxygen species. We also demonstrated that sesamin acted by rescuing tyrosine hydroxylase levels from MPP+-induced depletion. Sesamin, however, did not modulate dopamine transporter levels, and estrogen receptor-alpha and -beta protein expression. By examining several parameters of cell distress, we found that sesamin also elicited a strong increase in superoxide dismutase activity as well as protein expression and decreased catalase activity and the MPP+ stimulated inducible nitric oxide synthase protein expression, in neuronal PC12 cells. Finally, sesamin possessed significant anti-inflammatory properties, as disclosed by its potential to reduce MPP+-induced interleukin-6 mRNA levels in microglia. From these studies, we determined the importance of the lignan sesamin as a neuroprotective molecule and its possible role in complementary and/or preventive therapies of neurodegenerative diseases.

  19. Phenylalanine hydroxylase: function, structure, and regulation.

    Science.gov (United States)

    Flydal, Marte I; Martinez, Aurora

    2013-04-01

    Mammalian phenylalanine hydroxylase (PAH) catalyzes the rate-limiting step in the phenylalanine catabolism, consuming about 75% of the phenylalanine input from the diet and protein catabolism under physiological conditions. In humans, mutations in the PAH gene lead to phenylketonuria (PKU), and most mutations are mainly associated with PAH misfolding and instability. The established treatment for PKU is a phenylalanine-restricted diet and, recently, supplementation with preparations of the natural tetrahydrobiopterin cofactor also shows effectiveness for some patients. Since 1997 there has been a significant increase in the understanding of the structure, catalytic mechanism, and regulation of PAH by its substrate and cofactor, in addition to improved correlations between genotype and phenotype in PKU. Importantly, there has also been an increased number of studies on the structure and function of PAH from bacteria and lower eukaryote organisms, revealing an additional anabolic role of the enzyme in the synthesis of melanin-like pigments. In this review, we discuss these recent studies, which contribute to define the evolutionary adaptation of the PAH structure and function leading to sophisticated regulation for effective catabolic processing of phenylalanine in mammalian organisms.

  20. Melanin biosynthesis inhibitory and antioxidant activities of quercetin-3'-O-beta-D-glucoside isolated from Allium cepa.

    Science.gov (United States)

    Arung, Enos Tangke; Furuta, Shoko; Ishikawa, Hiroya; Tanaka, Hiroyuki; Shimizu, Kuniyoshi; Kondo, Ryuichiro

    2011-01-01

    In the course of searching for new whitening agents, we have found that the methanol extract of dried skin of Allium cepa shows potent melanin biosynthesis inhibitory activity in B16 melanoma cells. Bioassay-guided fractionation led to the isolation of quercetin-3'-O-beta-D-glucoside (1) from the methanol extract of dried skin of A. cepa, which inhibited melanin formation in B16 melanoma cells with an IC50 value of 38.8 microM and mushroom tyrosinase with an IC50 value of 6.5 microM using L-tyrosine and 48.5 microM using L-dihydroxyphenylalanine as substrates, respectively. In addition, the antioxidant activity of 1 was evaluated in the oxygen radical absorbance capacity assay; it showed 3.04 micromol Trolox equivalents/mmol. 1 was shown to be a promising ingredient that could be useful for treating hyperpigmentation and for protecting against oxidative stress.

  1. A review on medicinal importance, pharmacological activity and bioanalytical aspects of beta-carboline alkaloid ‘‘Harmine’’

    Institute of Scientific and Technical Information of China (English)

    K Patel; M Gadewar; R Tripathi; SK Prasad; Dinesh Kumar Patel

    2012-01-01

    Harmine, a beta-carboline alkaloid, is widely distributed in the plants, marine creatures, insects, mammalians as well as in human tissues and body fluids. Harmine was originally isolated from seeds of Peganum harmal in 1847 having a core indole structure and a pyridine ring. Harmine has various types of pharmacological activities such as antimicrobial, antifungal, antitumor, cytotoxic, antiplasmodial, antioxidaant, antimutagenic, antigenotoxic and hallucinogenic properties. It acts on gamma-aminobutyric acid type A and monoamine oxidase A or B receptor, enhances insulin sensitivity and also produces vasorelaxant effect. Harmine prevents bone loss by suppressing osteoclastogenesis. The current review gives an overview on pharmacological activity and analytical techniques of harmine, which may be useful for researcheres to explore the hidden potential of harmine and and will also help in developing new drugs for the treatment of various diseases.

  2. A review on medicinal importance, pharmacological activity and bioanalytical aspects of beta-carboline alkaloid “Harmine”

    Directory of Open Access Journals (Sweden)

    K Patel

    2012-08-01

    Full Text Available Harmine, a beta-carboline alkaloid, is widely distributed in the plants, marine creatures, insects, mammalians as well as in human tissues and body fluids. Harmine was originally isolated from seeds of Peganum harmal in 1847 having a core indole structure and a pyridine ring. Harmine has various types of pharmacological activities such as antimicrobial, antifungal, antitumor, cytotoxic, antiplasmodial, antioxidaant, antimutagenic, antigenotoxic and hallucinogenic properties. It acts on gamma–aminobutyric acid type A and monoamine oxidase A or B receptor, enhances insulin sensitivity and also produces vasorelaxant effect. Harmine prevents bone loss by suppressing osteoclastogenesis. The current review gives an overview on pharmacological activity and analytical techniques of harmine, which may be useful for researcheres to explore the hidden potential of harmine and and will also help in developing new drugs for the treatment of various diseases.

  3. Mineralocorticoid replacement during infancy for salt wasting congenital adrenal hyperplasia due to 21-hydroxylase deficiency

    Directory of Open Access Journals (Sweden)

    Larissa G. Gomes

    2013-01-01

    Full Text Available OBJECTIVE: The protocols for glucocorticoid replacement in children with salt wasting 21-hydroxylase deficiency are well established; however, the current recommendation for mineralocorticoid replacement is general and suggests individualized dose adjustments. This study aims to retrospectively review the 9-∝-fludrocortisone dose regimen in salt wasting 21-hydroxylase deficient children who have been adequately treated during infancy. METHODS: Twenty-three salt wasting 21-hydroxylase deficient patients with good anthropometric and hormonal control were followed in our center since diagnosis. The assessments of cortisone acetate and 9-∝-fludrocortisone doses, anthropometric parameters, and biochemical and hormonal levels were rigorously evaluated in pre-determined intervals from diagnosis to two years of age. RESULTS: The 9-∝-fludrocortisone doses decreased over time during the first and second years of life; the median fludrocortisone doses were 200 µg at 0-6 months, 150 µg at 7-18 months and 125 µg at 19-24 months. The cortisone acetate dose per square meter was stable during follow-up (median = 16.8 mg/m²/day. The serum sodium, potassium and plasma rennin activity levels during treatment were normal, except in the first month of life, when periodic 9-∝-fludrocortisone dose adjustments were made. CONCLUSIONS: The mineralocorticoid needs of salt wasting 21-hydroxylase deficient patients are greater during early infancy and progressively decrease during the first two years of life, which confirms that a partial aldosterone resistance exists during this time. Our study proposes a safety regiment for mineralocorticoid replacement during this critical developmental period.

  4. CYP17A1 intron mutation causing cryptic splicing in 17α-hydroxylase deficiency.

    Directory of Open Access Journals (Sweden)

    Daw-Yang Hwang

    Full Text Available 17α-Hydroxylase/17, 20-lyase deficiency (17OHD is an autosomal recessive disease causing congenital adrenal hyperplasia and a rare cause of hypertension with hypokalemia. The CYP17A1 gene mutation leads to 17OHD and its clinical features. We described an 18 y/o female with clinical features of 17α-hydroxylase/17, 20-lyase deficiency and characterized the functional consequences of an intronic CYP17A1 mutation. The coding regions and flanking intronic bases of the CYP17A1 gene were amplified by PCR and sequenced. The patient is a compound heterozygote for the previously described p.R358X and IVS1 +2T>C mutations. A first intron splice donor site mutation was re-created in minigene and full-length expression vectors. Pre-mRNA splicing of the variant CYP17A1 intron was studied in transfected cells and in a transformed lymphoblastoid cell line. When the full-length CYP17A1 gene and minigene containing the intronic mutation was expressed in transfected cells, the majority (>90% of mRNA transcripts were incorrectly spliced. Only the p.R358X transcript was detected in the EBV-transformed lymphoblastoid cell line. The IVS1 +2T>C mutation abolished most 17α-hydroxylase/17, 20-lyase enzyme activity by aberrant mRNA splicing to an intronic pseudo-exon, causing a frame shift and early termination.

  5. Decreased activity and enhanced nuclear export of CCAAT-enhancer-binding protein beta during inhibition of adipogenesis by ceramide.

    Science.gov (United States)

    Sprott, Kam M; Chumley, Michael J; Hanson, Janean M; Dobrowsky, Rick T

    2002-07-01

    To identify novel molecular mechanisms by which ceramide regulates cell differentiation, we examined its effect on adipogenesis of 3T3-L1 preadipocytes. Hormonal stimulation of 3T3-L1 preadipocytes induced formation of triacylglycerol-laden adipocytes over 7 days; in part, via the co-ordinated action of CCAAT-enhancer-binding proteins alpha, beta and delta (C/EBP-alpha, -beta and -delta) and peroxisome-proliferator-activated receptor gamma (PPARgamma). The addition of exogenous N-acetylsphingosine (C2-ceramide) or increasing endogenous ceramide levels inhibited the expression of C/EBPalpha and PPARgamma, and blocked adipocyte development. C2-ceramide did not decrease the cellular expression of C/EBPbeta, which is required for expression of C/EBPalpha and PPARgamma, but significantly blocked its transcriptional activity from a promoter construct after 24 h. The ceramide-induced decrease in the transcriptional activity of C/EBPbeta correlated with a strong decrease in its phosphorylation, DNA-binding ability and nuclear localization at 24 h. However, ceramide did not change the nuclear level of C/EBPbeta after a period of 4 or 16 h, suggesting that it was not affecting nuclear import. CRM1 (more recently named 'exportin-1') is a nuclear membrane protein that regulates protein export from the nucleus by binding to a specific nuclear export sequence. Leptomycin B is an inhibitor of CRM1/exportin-1, and reversed the ceramide-induced decrease in nuclear C/EBPbeta at 24 h. Taken together, these data support the hypothesis that ceramide may inhibit adipogenesis, at least in part, by enhancing dephosphorylation and premature nuclear export of C/EBPbeta at a time when its maximal transcriptional activity is required to drive adipogenesis.

  6. Transforming growth factor beta isoforms regulation of Akt activity and XIAP levels in rat endometrium during estrous cycle, in a model of pseudopregnancy and in cultured decidual cells

    Directory of Open Access Journals (Sweden)

    Asselin Eric

    2009-08-01

    during pseudopregnancy. In cultured stromal cells, we found that TGF-beta3 isoform induced Smad2 phosphorylation, indicating that the Smad pathway is activated by TGF-beta3 in these cells. Furthermore, TGF-beta2 and TGF-beta3 induced a dose-dependant increase of apoptosis in cultured stromal cells, as demonstrated by Hoechst nuclear staining. Noteworthy, TGF-beta2 and TGF-beta3 reduced the level of the anti-apoptotic XIAP protein, as well as the level of phosphorylated/active Akt, a well known survival protein, in a dose-dependent manner. Conclusion Those results suggest that TGF-beta might play an important role in the remodelling endometrium during the estrous cycle and in the regulation of apoptosis in rat decidual cells, in which inhibition of Akt survival pathway might be an important mechanism involved in the regulation of apoptosis.

  7. Endotoxin/lipopolysaccharide activates NF-kappa B and enhances tumor cell adhesion and invasion through a beta 1 integrin-dependent mechanism.

    LENUS (Irish Health Repository)

    Wang, Jiang Huai

    2012-02-03

    Beta(1) integrins play a crucial role in supporting tumor cell attachment to and invasion into the extracellular matrix. Endotoxin\\/LPS introduced by surgery has been shown to enhance tumor metastasis in a murine model. Here we show the direct effect of LPS on tumor cell adhesion and invasion in extracellular matrix proteins through a beta(1) integrin-dependent pathway. The human colorectal tumor cell lines SW480 and SW620 constitutively expressed high levels of the beta(1) subunit, whereas various low levels of alpha(1), alpha(2), alpha(4), and alpha(6) expression were detected. SW480 and SW620 did not express membrane-bound CD14; however, LPS in the presence of soluble CD14 (sCD14) significantly up-regulated beta(1) integrin expression; enhanced tumor cell attachment to fibronectin, collagen I, and laminin; and strongly promoted tumor cell invasion through the Matrigel. Anti-beta(1) blocking mAbs (4B4 and 6S6) abrogated LPS- plus sCD14-induced tumor cell adhesion and invasion. Furthermore, LPS, when combined with sCD14, resulted in NF-kappaB activation in both SW480 and SW620 cells. Inhibition of the NF-kappaB pathway significantly attenuated LPS-induced up-regulation of beta(1) integrin expression and prevented tumor cell adhesion and invasion. These results provide direct evidence that although SW480 and SW620 cells do not express membrane-bound CD14, LPS in the presence of sCD14 can activate NF-kappaB, up-regulate beta(1) integrin expression, and subsequently promote tumor cell adhesion and invasion. Moreover, LPS-induced tumor cell attachment to and invasion through extracellular matrix proteins is beta(1) subunit-dependent.

  8. Follicle-stimulating hormone (FSH activates extracellular signal-regulated kinase phosphorylation independently of beta-arrestin- and dynamin-mediated FSH receptor internalization

    Directory of Open Access Journals (Sweden)

    Crepieux Pascale

    2006-06-01

    Full Text Available Abstract Background The follicle-stimulating hormone receptor (FSH-R is a seven transmembrane spanning receptor (7TMR which plays a crucial role in male and female reproduction. Upon FSH stimulation, the FSH-R activates the extracellular signal-regulated kinases (ERK. However, the mechanisms whereby the agonist-stimulated FSH-R activates ERK are poorly understood. In order to activate ERK, some 7 TMRs require beta-arrestin-and dynamin-dependent internalization to occur, whereas some others do not. In the present study, we examined the ability of the FSH-activated FSH-R to induce ERK phosphorylation, in conditions where its beta-arrestin- and dynamin-mediated internalization was impaired. Methods Human embryonic kidney (HEK 293 cells were transiently transfected with the rat FSH-R. Internalization of the FSH-R was manipulated by co-expression of either a beta-arrestin (319–418 dominant negative peptide, either an inactive dynamin K44A mutant or of wild-type beta-arrestin 1 or 2. The outcomes on the FSH-R internalization were assayed by measuring 125I-FSH binding at the cell surface when compared to internalized 125I-FSH binding. The resulting ERK phosphorylation level was visualized by Western blot analysis. Results In HEK 293 cells, FSH stimulated ERK phosphorylation in a dose-dependent manner. Co-transfection of the beta- arrestin (319–418 construct, or of the dynamin K44A mutant reduced FSH-R internalization in response to FSH, without affecting ERK phosphorylation. Likewise, overexpression of wild-type beta-arrestin 1 or 2 significantly increased the FSH-R internalization level in response to FSH, without altering FSH-induced ERK phosphorylation. Conclusion From these results, we conclude that the FSH-R does not require beta-arrestin- nor dynamin-mediated internalization to initiate ERK phosphorylation in response to FSH.

  9. The kiwifruit lycopene beta-cyclase plays a significant role in carotenoid accumulation in fruit.

    Science.gov (United States)

    Ampomah-Dwamena, Charles; McGhie, Tony; Wibisono, Reginald; Montefiori, Mirco; Hellens, Roger P; Allan, Andrew C

    2009-01-01

    The composition of carotenoids, along with anthocyanins and chlorophyll, accounts for the distinctive range of colour found in the Actinidia (kiwifruit) species. Lutein and beta-carotene are the most abundant carotenoids found during fruit development, with beta-carotene concentration increasing rapidly during fruit maturation and ripening. In addition, the accumulation of beta-carotene and lutein is influenced by the temperature at which harvested fruit are stored. Expression analysis of carotenoid biosynthetic genes among different genotypes and fruit developmental stages identified Actinidia lycopene beta-cyclase (LCY-beta) as the gene whose expression pattern appeared to be associated with both total carotenoid and beta-carotene accumulation. Phytoene desaturase (PDS) expression was the least variable among the different genotypes, while zeta carotene desaturase (ZDS), beta-carotene hydroxylase (CRH-beta), and epsilon carotene hydroxylase (CRH-epsilon) showed some variation in gene expression. The LCY-beta gene was functionally tested in bacteria and shown to convert lycopene and delta-carotene to beta-carotene and alpha-carotene respectively. This indicates that the accumulation of beta-carotene, the major carotenoid in these kiwifruit species, appears to be controlled by the level of expression of LCY-beta gene.

  10. Tissue-specific expression of betaKlotho and fibroblast growth factor (FGF) receptor isoforms determines metabolic activity of FGF19 and FGF21.

    Science.gov (United States)

    Kurosu, Hiroshi; Choi, Mihwa; Ogawa, Yasushi; Dickson, Addie S; Goetz, Regina; Eliseenkova, Anna V; Mohammadi, Moosa; Rosenblatt, Kevin P; Kliewer, Steven A; Kuro-o, Makoto

    2007-09-14

    The fibroblast growth factor (FGF) 19 subfamily of ligands, FGF19, FGF21, and FGF23, function as hormones that regulate bile acid, fatty acid, glucose, and phosphate metabolism in target organs through activating FGF receptors (FGFR1-4). We demonstrated that Klotho and betaKlotho, homologous single-pass transmembrane proteins that bind to FGFRs, are required for metabolic activity of FGF23 and FGF21, respectively. Here we show that, like FGF21, FGF19 also requires betaKlotho. Both FGF19 and FGF21 can signal through FGFR1-3 bound by betaKlotho and increase glucose uptake in adipocytes expressing FGFR1. Additionally, both FGF19 and FGF21 bind to the betaKlotho-FGFR4 complex; however, only FGF19 signals efficiently through FGFR4. Accordingly, FGF19, but not FGF21, activates FGF signaling in hepatocytes that primarily express FGFR4 and reduces transcription of CYP7A1 that encodes the rate-limiting enzyme for bile acid synthesis. We conclude that the expression of betaKlotho, in combination with particular FGFR isoforms, determines the tissue-specific metabolic activities of FGF19 and FGF21.

  11. Interleukin-1-mediated febrile responses in mice and interleukin-1 beta activation of NFkappaB in mouse primary astrocytes, involves the interleukin-1 receptor accessory protein.

    Science.gov (United States)

    Zetterström, M; Lundkvist, J; Malinowsky, D; Eriksson, G; Bartfai, T

    1998-06-01

    The endogenous pyrogen interleukin-1 (IL-1) is considered as one of the key molecules in orchestrating the host response of injury and inflammation. IL-1 exerts its effects upon binding to the type I IL-1 receptor (IL-1RI). The IL-1-IL-1RI complex is further thought to associate with the IL-1 receptor accessory protein (IL-1RAcP), which is suggested to be important for most IL-1 signal transduction pathways. With the aim of investigating the importance of the IL-1RAcP in IL-1 signalling, IL-1alpha and IL-1beta induced febrile responses and IL-1beta-mediated activation of NFkappaB in primary astrocyte cultures were examined using IL-1RAcP-deficient (IL-1RAcP KO) and wild type mice, respectively. It was shown that neither recombinant rat IL-1alpha (rrIL-1alpha, 25 microg/kg), recombinant rat IL-1beta (rrIL-1beta, 40 microg/kg) nor recombinant human IL-1beta (rhIL-1beta, 50 microg/kg) injected i.p. could elicit febrile responses in the IL-1RAcP-deficient mice, while the same doses of rrIL-1alpha/beta or rhIL-1beta injected into wild type mice caused normal fever responses. A febrile response could be induced in the IL-1RAcP-deficient mice by i.p. administration of E. coli lipopolysaccharide (LPS, 50 microg/kg) and this response was similar to that obtained in wild type mice. Furthermore, it was shown that rhIL-1beta activated, in a concentration-dependent manner, nuclear translocation of the transcriptional nuclear factor kappa B (NFkappaB) in primary astrocyte cultures prepared from wild type mice, whereas no IL-1beta-induced translocation of NFkappaB could be detected in cultures prepared from IL-1RAcP-deficient mice, as revealed by electrophoretic mobility shift assay (EMSA). The rhIL-1beta-induced NFkappaB complexes were shown to contain p50 but no, or very little, p65 and cRel immunoreactive proteins.

  12. Early activation of FGF and nodal pathways mediates cardiac specification independently of Wnt/beta-catenin signaling.

    Directory of Open Access Journals (Sweden)

    Lee J Samuel

    Full Text Available BACKGROUND: Cardiac induction, the first step in heart development in vertebrate embryos, is thought to be initiated by anterior endoderm during gastrulation, but what the signals are and how they act is unknown. Several signaling pathways, including FGF, Nodal, BMP and Wnt have been implicated in cardiac specification, in both gain- and loss-of-function experiments. However, as these pathways regulate germ layer formation and patterning, their specific roles in cardiac induction have been difficult to define. METHODOLOGY/PRINCIPAL FINDINGS: To investigate the mechanisms of cardiac induction directly we devised an assay based on conjugates of anterior endoderm from early gastrula stage Xenopus embryos as the inducing tissue and pluripotent ectodermal explants as the responding tissue. We show that the anterior endoderm produces a specific signal, as skeletal muscle is not induced. Cardiac inducing signal needs up to two hours of interaction with the responding tissue to produce an effect. While we found that the BMP pathway was not necessary, our results demonstrate that the FGF and Nodal pathways are essential for cardiogenesis. They were required only during the first hour of cardiogenesis, while sustained activation of ERK was required for at least four hours. Our results also show that transient early activation of the Wnt/beta-catenin pathway has no effect on cardiogenesis, while later activation of the pathway antagonizes cardiac differentiation. CONCLUSIONS/SIGNIFICANCE: We have described an assay for investigating the mechanisms of cardiac induction by anterior endoderm. The assay was used to provide evidence for a direct, early and transient requirement of FGF and Nodal pathways. In addition, we demonstrate that Wnt/beta-catenin pathway plays no direct role in vertebrate cardiac specification, but needs to be suppressed just prior to differentiation.

  13. A quantitation of the factors which affect the hydrolase and transgalactosylase activities of beta-galactosidase (E. coli) on lactose.

    Science.gov (United States)

    Huber, R E; Kurz, G; Wallenfels, K

    1976-05-04

    A study was implemented to quantitate the hydrolase and transgalactosylase activities of beta-galactosidase (E. coli) with lactose as the substrate and to investigate various factors which affect these activities. At low lactose concentrations the rate of galactose production was equal to the rate of glucose production. The rate of galactose production relative to glucose, however, dropped dramatically at lactose concentrations higher than 0.05 M and production of trisaccharides and tetrasaccharides began (galactose/glucose ratios of about 2:1 and 3:1, respectively, were found for these two types of oligosaccharides). At least five different trissacharides were formed and their patterns of formation showed that they probably utilized both lactose and allolactose as galactosyl acceptors. Allolactose was produced in amounts proportional to glucose at all lactose concentrations (ratios of allolactose/glucose were about 0.88). Analyses of various data, including a reaction analyzed at very early times, showed that the major means of production of allolactose (and the only means initially) was the direct enzymatic transfer of galactose from the 4 position to the 6 position of the glucose moiety of lactose without prior release of glucose from the enzyme. It was shown, however, that allolactose could also be formed in significant quantities by the transfer of galactose to the 6 position of free glucose, and also by hydrolysis of preformed trisaccharide. A mechanism which fits the initial velocity data was proposed in which the steps involving the formation of an enzyme-gallactose-glucose complex, the formation and breakage of allolactose on the enzyme, and the release of glucose all seem to be of roughly equal magnitude and rate determining. Various factors affected the amounts of transgalactosylase and hydrolase activities occurring. At high pH values (greater than 7.8) the transgalactosylase/hydrolyase activity ratio increased dramatically while it decreased at low p

  14. Atividade antioxidante do beta-caroteno e da vitamina A. Estudo comparativo com antioxidante sintético beta-carotene and vitamin A antioxidant activity. Comparative study with synthetic antioxidant

    Directory of Open Access Journals (Sweden)

    José Afonso PASSOTTO

    1998-04-01

    Full Text Available Foi avaliada a atividade antioxidante da vitamina A na forma de acetato de retinol e de seu principal precursor, o beta-caroteno, adicionados a um sistema de óleo de soja previamente sensibilizado à oxidação. Os parâmetros utilizados como grau de atividade oxidativa foram: índice de peróxidos, teores de malonaldeído durante os intervalos de 24 a 72 horas, e perfil dos ácidos linoléico e linolênico após 144 horas de oxidação. Pelos resultados pode-se verificar que o retinol apresentou atividade antioxidante superior ao beta-caroteno. As determinações das atividades antioxidantes foram comparadas à do butilhidroxitolueno (BHT. A eficiência antioxidante da vitamina A e do beta-caroteno foram proporcionais às suas resistências à decomposição no sistema oxidativo. O acetato de retinol, a exemplo do BHT, mostrou uma rápida interação com os radicais ativos, pois já no início de sua adição ao óleo de soja, reduziu o nível da oxidação em relação ao respectivo controle.In soybean oil suceptible to oxidation the authors studied the antioxidant activity of the vitamin A as retinol acetate and the beta-carotene was studied. The oxidation index of the system was determined by peroxide and malonaldehyde values during the intervals from 24 to 72 hours and profile of the linoleic and linolenic acids after 144 hours of oxidation. It was observed that the retinol acetate had an antioxidant activity greater than beta-carotene. The antioxidant activity of retinol acetate and beta-carotene were compared to the butyl hidroxi toluene (BHT and was observed that the antioxidant efficiency was directly proportional to degradation resistance of them in the oxidative system. The retinol acetate, as such BHT, showed a fast interaction with actives radicals, in the beginning of the addition to the soybean oil, reducing the oxidation level when compared to the control.

  15. Expression of Tyrosine Hydroxylase is Negatively Regulated Via Prion Protein.

    Science.gov (United States)

    da Luz, Marcio Henrique Mello; Glezer, Isaias; Xavier, Andre Machado; da Silva, Marcelo Alberti Paiva; Pino, Jessica Monteiro Volejnik; Zamith, Thiago Panaro; Vieira, Taynara Fernanda; Antonio, Bruno Brito; Antunes, Hanna Karen Moreira; Martins, Vilma Regina; Lee, Kil Sun

    2016-07-01

    Cellular prion protein (PrP(C)) is a glycoprotein of the plasma membrane that plays pleiotropic functions by interacting with multiple signaling complexes at the cell surface. Recently, a number of studies have reported the involvement of PrP(C) in dopamine metabolism and signaling, including its interactions with tyrosine hydroxylase (TH) and dopamine receptors. However, the outcomes reported by independent studies are still debatable. Therefore in this study, we investigated the effects of PrP(C) on the TH expression during the differentiation of N2a cells with dibutyryl-cAMP, a well-known cAMP analog that activates TH transcription. Upon differentiation, TH was induced with concomitant reduction of PrP(C) at protein level, but not at mRNA level. shRNA-mediated PrP(C) reduction increased the basal level of TH at both mRNA and protein levels without dibutyryl-cAMP treatment. This phenotype was reversed by re-expression of PrP(C). PrP(C) knockdown also potentiated the effect of dibutyryl-cAMP on TH expression. Our findings suggest that PrP(C) has suppressive effects on TH expression. As a consequence, altered PrP(C) functions may affect the regulation of dopamine metabolism and related neurological disorders.

  16. Catalytic domain surface residues mediating catecholamine inhibition in tyrosine hydroxylase.

    Science.gov (United States)

    Briggs, Gabrielle D; Bulley, Jesse; Dickson, Phillip W

    2014-03-01

    Tyrosine hydroxylase (TH) performs the rate-limiting step in catecholamine (CA) synthesis and is a tetramer composed of regulatory, catalytic and tetramerization domains. CAs inhibit TH by binding two sites in the active site; one with high affinity and one with low affinity. Only high affinity CA binding requires the regulatory domain, believed to interact with the catalytic domain in the presence of CA. Without a crystal structure of the regulatory domain, the specific areas involved in this process are largely undefined. It is not clear whether the regulatory domain-catalytic domain interaction is asymmetrical across the tetramer to produce the high and low affinity sites. To investigate this, pure dimeric TH was generated through double substitution of residues at the tetramerization interface and dimerization salt bridge (K170E/L480A). This was shown to be the core regulatory unit of TH for CA inhibition, possessing both high and low affinity CA binding sites, indicating that there is symmetry between dimers of the tetramer. We also examined possible regulatory domain-interacting regions on the catalytic domain that mediate high affinity CA binding. Using site-directed mutagenesis, A297, E362/E365 and S368 were shown to mediate high affinity dopamine inhibition through V(max) reduction and increasing the K(M) for the cofactor.

  17. Expression of the vitamin D receptor, 25-hydroxylases, 1alpha-hydroxylase and 24-hydroxylase in the human kidney and renal clear cell cancer

    DEFF Research Database (Denmark)

    Blomberg Jensen, Martin; Andersen, Claus B.; Nielsen, John E;

    2010-01-01

    The vitamin D receptor (VDR), CYP27B1 and CYP24A1 are expressed in the human kidney, but the segmental expression of the 25-hydroxylases is unknown. A comprehensive analysis of CYP2R1, CYP27A1, CYP27B1, VDR and CYP24A1 expression in normal kidney and renal clear cell cancer (CCc) would reveal...

  18. Quality control on the accuracy of the total Beta activity index in different sample matrices water; Control de calidad en la precision del indice de actividad beta total en diferentes matrices de muestras de aguas

    Energy Technology Data Exchange (ETDEWEB)

    Pujol, L.; Pablo, M. A. de; Payeras, J.

    2013-07-01

    The standard ISO/IEC 17025:2005 of general requirements for the technical competence of testing and calibration laboratories, provides that a laboratory shall have quality control procedures for monitoring the validity of tests and calibrations ago. In this paper, the experience of Isotopic Applications Laboratory (CEDEX) in controlling the accuracy rate of total beta activity in samples of drinking water, inland waters and marine waters is presented. (Author)

  19. Validation the quantification of beta emitters activity in urine by scintillation spectrometry in the liquid phase; Validacion de la cuantificacion de actividad de emisores beta en orina mediante espectrometria de centelleo en fase liquida

    Energy Technology Data Exchange (ETDEWEB)

    Sierra, I.; Hernandez, C.; Benito, P.; Lopez, C.

    2013-07-01

    In this paper the methodology used in the validation of the technique for quantifying activity of some beta emitters in urine ({sup 3}H, {sup 1}4C, {sup 3}5S, {sup 3}2P and {sup 9}0Sr) by scintillation spectrometry Liquid Phase (Liquid Scintillation Counting, LSC) is described in bio elimination Laboratory Service CIEMAT Radiation Dosimetry accredited since last year for carrying out assays measure radiation dose based on ISO forth above. (Author)

  20. Mutant p53 attenuates the anti-tumorigenic activity of fibroblasts-secreted interferon beta.

    Directory of Open Access Journals (Sweden)

    Shalom Madar

    Full Text Available Mutations in the p53 tumor suppressor protein are highly frequent in tumors and often endow cells with tumorigenic capacities. We sought to examine a possible role for mutant p53 in the cross-talk between cancer cells and their surrounding stroma, which is a crucial factor affecting tumor outcome. Here we present a novel model which enables individual monitoring of the response of cancer cells and stromal cells (fibroblasts to co-culturing. We found that fibroblasts elicit the interferon beta (IFNβ pathway when in contact with cancer cells, thereby inhibiting their migration. Mutant p53 in the tumor was able to alleviate this response via SOCS1 mediated inhibition of STAT1 phosphorylation. IFNβ on the other hand, reduced mutant p53 RNA levels by restricting its RNA stabilizer, WIG1. These data underscore mutant p53 oncogenic properties in the context of the tumor microenvironment and suggest that mutant p53 positive cancer patients might benefit from IFNβ treatment.

  1. Searches for Active and Sterile Neutrinos in Beta-Ray Spectra

    CERN Document Server

    Dragoun, Otokar

    2015-01-01

    Although neutrinos are probably the most abundant particles of the universe their mass is yet unknown. The oscillation experiments proved that at least one of the neutrino mass states is heavier than 0.05 eV. Strongly model dependent interpretations of cosmological observations yielded for the sum of the neutrino mass states the values between 0.12 and 1.7 eV. The almost model independent analyses of measured tritium \\b{eta}- spectra provided the upper limit of the effective electron neutrino mass of 2 eV. The upcoming KATRIN experiment aims to achieve ten times higher sensitivity. In this review, we try to summarize the experience of two generations of \\b{eta}-ray spectroscopists who improved the limit of the neutrino mass by three orders of magnitude. We describe important steps in the development of radioactive sources and electron spectrometers, and recapitulate the lessons from now disproved claims for the neutrino of 30 eV mass and the 17 keV neutrino with an admixture larger than 0.07 %. We also pay at...

  2. Inhibition of transforming growth factor-beta-induced liver fibrosis by a retinoic acid derivative via the suppression of Col 1A2 promoter activity.

    Science.gov (United States)

    Yang, Kun-Lin; Chang, Wen-Teng; Hung, Kuo-Chen; Li, Eric I C; Chuang, Chia-Chang

    2008-08-22

    Transforming growth factor-beta1 (TGF-beta1) mediates expression of collagen 1A2 (Col 1A2) gene via a synergistic cooperation between Smad2/Smad3 and Sp1, both act on the Col 1A2 gene promoter. In our previous study, we reported that a retinoic acid derivative obtained from Phellinus linteus (designated PL) antagonizes TGF-beta-induced liver fibrosis through regulation of ROS and calcium influx. In this continuing study we seek further the effect of PL on the Smad signaling pathway. We used a Col 1A2 promoter-luciferase construct to study the action of PL on Smad through TGF-beta. We found that PL decreases the promoter activity of Col 1A2, hinders the translocalization of phosphorylated Smad2/3-Smad 4 complex from cytosol into nucleus and inhibits Sp1 binding activity. These results suggest that PL inhibits TGF-beta1-induced Col 1A2 promoter activity through blocking ROS and calcium influx as well as impeding Sp1 binding and translocalization of pSmad 2/3-Smad4 complex into nucleus.

  3. Activity-Based Profiling of Retaining beta-Glucosidases : A Comparative Study

    NARCIS (Netherlands)

    Witte, Martin D.; Walvoort, Marthe T. C.; Li, Kah-Yee; Kallemeijn, Wouter W.; Donker-Koopman, Wilma E.; Boot, Rolf G.; Aerts, Johannes M. F. G.; Codee, Jeroen D. C.; van der Marel, Gijsbert A.; Overkleeft, Herman S.

    2011-01-01

    Activity-based protein profiling (ABPP) is a versatile strategy to report on enzyme activity in vitro, in situ, and in vivo. The development and use of ABPP tools and techniques has met with considerable success in monitoring physiological processes involving esterases and proteases. Activity-based

  4. Determination of Sr{sup 90}, Sb{sup 125}, Cs{sup 137} and absolute beta activities in First Cycle Supernatent

    Energy Technology Data Exchange (ETDEWEB)

    Helmholz, H.R.

    1954-03-15

    This report discusses procedures have been established for determining the absolute activities of Sr{sup 90}, Sb{sup 125}, Cs{sup 137}, and gross beta in First Cycle Supernatant. These procedures are also valid for other samples such as scavenged Radioactive Waste (RAW), the primary restriction being that the age of the material be at least 250 days so that any Sr{sup 89} activity (53 day half-life) is negligible. With the exception of the gross beta analysis the results are believed to be accurate to within 10%.

  5. Upregulating of Fas, integrin beta4 and P53 and depressing of PC-PLC activity and ROS level in VEC apoptosis by safrole oxide.

    Science.gov (United States)

    Zhao, Jing; Miao, Junying; Zhao, Baoxiang; Zhang, Shangli

    2005-10-24

    Previously, we found that safrole oxide could trigger vascular endothelial cell (VEC) apoptosis. In this study, to investigate its mechanism to induce apoptosis in VECs, the activities of nitric oxide synthetase and phosphatidylcholine specific phospholipase C, the level of reactive oxygen species and the expressions of Fas, integrin beta4 and P53 were analyzed. The data showed that safrole oxide induced apoptosis by increasing the expressions of Fas, integrin beta4 and P53, and depressing the activity of Ca(2+)-independent phosphatidylcholine-specific phospholipase C and intracellular reactive oxygen species levels in VECs.

  6. Optimizing the enzymatic synthesis of beta-D-galactopyranosyl-D-xyloses for their use in the evaluation of lactase activity in vivo.

    Science.gov (United States)

    Hermida, Carmen; Corrales, Guillermo; Cañada, Francisco J; Aragón, Juan J; Fernández-Mayoralas, Alfonso

    2007-07-15

    Disaccharides 2-O-, 3-O-, and 4-O-beta-D-galactopyranosyl-D-xyloses (2, 3, and 1, respectively) were obtained by beta-galactosidase-catalyzed reactions for their use in the evaluation of intestinal lactase activity in vivo. Their administration to suckling rats followed by determination of the derived D-xylose in the urine and measurement of lactase activity in intestinal homogenates showed 1 to be the most suitable disaccharide for a potential test of the deficiency of intestinal lactase. The synthesis of 1 was further studied by evaluating the effect of different variables on the yield and regioselectivity of the enzymatic galactosylation, and the purification process was optimized.

  7. Activation of transgenic estrogen receptor-beta by selected phytoestrogens in a stably transduced rat serotonergic cell line.

    Science.gov (United States)

    Amer, Dena A M; Kretzschmar, Georg; Müller, Nicole; Stanke, Nicole; Lindemann, Dirk; Vollmer, Günter

    2010-06-01

    Many flavonoids, a major group of phenolic plant-derived secondary metabolites, are known to possess estrogen-like bioactivities. However, little is known about their estrogenic properties in the central nervous system due to the lack of suitable cellular models expressing sufficient amounts of functional estrogen receptor beta (ERbeta). To overcome this deficit, we have created a cellular model, which is serotonergic in origin, to study properties of estrogenic substances by stably transducing RN46A-B14 cells derived from raphe nuclei region of the rat brain with a lentiviral vector encoding a human ERbeta. We clearly showed that the transgenic human ERbeta is a spontaneously expressed and a functional receptor. We have further assessed the estrogenicity of three different isoflavones and four different naringenin-type flavanones in this cell line utilizing a luciferase reporter gene assay. Genistein (GEN), Daidzein (DAI), Equol (EQ), Naringenin (NAR) and 8-prenylnaringenin (8-PN) showed strong estrogenic activity in a concentration-dependent manner as compared to 7-(O-prenyl)naringenin-4'-acetate (7-O-PN) which was only slightly estrogenic and 6-(1,1-dimethylallyl)naringenin (6-DMAN) that neither showed estrogenic nor anti-estrogenic activity in our model. All observed effects could be antagonized by the anti-estrogen fulvestrant. Moreover, co-treatment of cells with 17beta-estradiol (E2) and either GEN or DAI showed a slight additive effect as compared to EQ. On the other hand, 8-PN in addition to 7-O-PN, but not NAR and 6-DMAN, were able to slightly antagonize the responses triggered by E2. Our newly established cellular model may prove to be a useful tool in explicating basic physiological properties of ERbeta in the brain and may help unravel molecular and cellular mechanisms involved in serotonergic mood regulation by estrogen or potential plant-derived secondary metabolites.

  8. Positive regulation of the peroxisomal beta-oxidation pathway by fatty acids through activation of peroxisome proliferator-activan>ated receptors (PPAR).

    Science.gov (United States)

    Dreyer, C; Keller, H; Mahfoudi, A; Laudet, V; Krey, G; Wahli, W

    1993-01-01

    Peroxisome proliferators regulate the transcription of genes by activating ligand-dependent transcription factors, which, due to their structure and function, can be assigned to the superfamily of nuclear hormone receptors. Three such peroxisome proliferator-activan>ated receptors (PPAR alpha, beta, and gamma) have been cloned in Xenopus laevis. Their mRNAs are expressed differentially; xPPAR alpha and beta but not xPPAR gamma are expressed in oocytes and embryos. In the adult, expression of xPPAR alpha and beta appears to be ubiquitous, and xPPAR gamma is mainly observed in adipose tissue and kidney. Immunocytochemical analysis revealed that PPARs are nuclear proteins, and that their cytoplasmic-nuclear translocation is independent of exogenous activators. A target gene of PPARs is the gene encoding acyl-CoA oxidase (ACO), which catalyzes the rate-limiting step in the peroxisomal beta-oxidation of fatty acids. A peroxisome proliferator response element (PPRE), to which PPARs bind, has been identified within the promoter of the ACO gene. Besides the known xenobiotic activators of PPARs, such as hypolipidemic drugs, natural activators have been identified. Polyunsaturated fatty acids at physiological concentrations are efficient activators of PPARs, and 5,8,11,14-eicosatetraynoic acid (ETYA), which is the alkyne homolog of arachidonic acid, is the most potent activator of xPPAR alpha described to date. Taken together, our data suggest that PPARs have an important role in lipid metabolism.

  9. Differential protective effects of exenatide, an agonist of GLP-1 receptor and Piragliatin, a glucokinase activator in beta cell response to streptozotocin-induced and endoplasmic reticulum stresses.

    Directory of Open Access Journals (Sweden)

    Mi-Kyung Kim

    Full Text Available BACKGROUND: Agonists of glucagon-like peptide-1 receptor (GLP-1R and glucokinase activators (GKA act as antidiabetic agents by their ability protect beta cells, and stimulate insulin secretion. Oxidative and endoplasmic reticulum (ER stresses aggravate type 2 diabetes by causing beta cell loss. It was shown that GLP-1R agonists protect beta cells from oxidative and ER stresses. On the other hand, little is known regarding how GKAs protect beta cells. We hypothesized that GKAs protect beta cells by mechanisms distinct from those underlying GLP-1R agonist and tested our hypothesis by comparing the molecular effects of exenatide, a GLP-1R agonist, and piragliatin, a GKA, on INS-1 cells under oxidative and ER-induced stresses. METHODS: BETA CELLS WERE TREATED WITH STREPTOZOTOCIN (STZ TO INDUCE OXIDATIVE STRESS AND WITH PALMITATE OR THAPSIGARGIN (TG TO INDUCE ER STRESS RESPECTIVELY, AND THE EFFECTS OF EXENATIDE AND PIRAGLIATIN ON THESE CELLS WERE INVESTIGATED BY: a characterizing the kinases involved employing specific kinase inhibitors, and b by identifying the differentially regulated proteins in response to stresses with proteomic analysis. RESULTS: Exenatide protected INS-1 cells from both ER and STZ-induced death. In contrast, piragliatin rescued the cells only from STZ-induced stress. Akt activation by exenatide appeared to contribute to its protective effects of beta cells while enhanced glucose utilization was the contributing factor in the case of piragliatin. Also, exenatide, not piragliatin, blocked changes in proteins 14-3-3β, ε and θ, and preserved the 14-3-3θ levels under the ER stress. Isoform-specific modifications of 14-3-3, and the reduction of 14-3-3θ, commonly associated with beta cell death were assessed. CONCLUSIONS: Exenatide and piragliatin exert distinct effects on beta cell survival and thus on type 2 diabetes. This study which confirmed our hypothesis is also the first to observe specific modulation of 14-3-3 isoform

  10. Threonine 79 is a hinge residue that governs the fidelity of DNA polymerase beta by helping to position the DNA within the active site.

    Science.gov (United States)

    Maitra, Mausumi; Gudzelak, Andrew; Li, Shu-Xia; Matsumoto, Yoshihiro; Eckert, Kristin A; Jager, Joachim; Sweasy, Joann B

    2002-09-20

    DNA polymerase beta (pol beta) is an ideal system for studying the role of its different amino acid residues in the fidelity of DNA synthesis. In this study, the T79S variant of pol beta was identified using an in vivo genetic screen. T79S is located in the N-terminal 8-kDa domain of pol beta and has no contact with either the DNA template or the incoming dNTP substrate. The T79S protein produced 8-fold more multiple mutations in the herpes simplex virus type 1-thymidine kinase assay than wild-type pol beta. Surprisingly, T79S is a misincorporation mutator only when using a 3'-recessed primer-template. In the presence of a single nucleotide-gapped DNA substrate, T79S displays an antimutator phenotype when catalyzing DNA synthesis opposite template C and has similar fidelity as wild type opposite templates A, G, or T. Threonine 79 is located directly between two helix-hairpin-helix motifs located within the 8-kDa and thumb domains of pol beta. As the pol beta enzyme closes into its active form, the helix-hairpin-helix motifs appear to assist in the production and stabilization of a 90 degrees bend of the DNA. The function of the bent DNA is to present the templating base to the incoming nucleotide substrate. We propose that Thr-79 is part of a hydrogen bonding network within the helix-hairpin-helix motifs that is important for positioning the DNA within the active site. We suggest that alteration of Thr-79 to Ser disrupts this hydrogen bonding network and results in an enzyme that is unable to bend the DNA into the proper geometry for accurate DNA synthesis.

  11. Interleukin-1beta exacerbates and interleukin-1 receptor antagonist attenuates neuronal injury and microglial activation after excitotoxic damage in organotypic hippocampal slice cultures.

    Science.gov (United States)

    Hailer, Nils P; Vogt, Cornelia; Korf, Horst-Werner; Dehghani, Faramarz

    2005-05-01

    The effects of interleukin (IL)-1beta and IL-1 receptor antagonist (IL-1ra) on neurons and microglial cells were investigated in organotypic hippocampal slice cultures (OHSCs). OHSCs obtained from rats were excitotoxically lesioned after 6 days in vitro by application of N-methyl-D-aspartate (NMDA) and treated with IL-1beta (6 ng/mL) or IL-1ra (40, 100 or 500 ng/mL) for up to 10 days. OHSCs were then analysed by bright field microscopy after hematoxylin staining and confocal laser scanning microscopy after labeling of damaged neurons with propidium iodide (PI) and fluorescent staining of microglial cells. The specificity of PI labeling of damaged neurons was validated by triple staining with neuronal and glial markers and it was observed that PI accumulated in damaged neurons only but not in microglial cells or astrocytes. Treatment of unlesioned OHSCs with IL-1beta did not induce neuronal damage but caused an increase in the number of microglial cells. NMDA lesioning alone resulted in a massive increase in the number of microglial cells and degenerating neurons. Treatment of NMDA-lesioned OHSCs with IL-1beta exacerbated neuronal cell death and further enhanced microglial cell numbers. Treatment of NMDA-lesioned cultures with IL-1ra significantly attenuated NMDA-induced neuronal damage and reduced the number of microglial cells, whereas application of IL-1ra in unlesioned OHSCs did not induce significant changes in either cell population. Our findings indicate that: (i) IL-1beta directly affects the central nervous system and acts independently of infiltrating hematogenous cells; (ii) IL-1beta induces microglial activation but is not neurotoxic per se; (iii) IL-1beta enhances excitotoxic neuronal damage and microglial activation and (iv) IL-1ra, even when applied for only 4 h, reduces neuronal cell death and the number of microglial cells after excitotoxic damage.

  12. Ovarian intratumoral 21-hydroxylase deficiency in a postmenopausal hirsute woman.

    Science.gov (United States)

    Souto, Selma B; Baptista, Pedro V; Barreto, Filomena; Sousa, Pedro F; Braga, Daniel C; Carvalho, Davide

    2012-12-01

    Virilising ovarian tumours are a rare cause of hyperandrogenism in women, accounting for less than 5% of all ovarian neoplasms. It occurs most often in - and postmenopausal women. We report a case of a 64 year-old woman with signs of virilisation that had started 3 years before. Blood hormone analysis revealed increased levels of testosterone, and 17-hydroxyprogesterone. The tetracosactin test revealed 21-hydroxylase deficiency. Radiological imaging demonstrated a nodule in her left ovary. The patient was submitted to bilateral laparoscopic oophorectomy, and histopathological examination revealed a luteoma of the left ovary. Postoperative serum testosterone level and 17-hydroxyprogesterone returned to normal levels in one month. Virilism regressed within six months. Our patient also showed an elevation in 17-OHP serum levels. Normalization of 17-OHP after oophorectomy suggests a case of intratumoral 21-hydroxylase deficiency. To our knowledge, this is the first description of ovarian intratumoral 21-hydroxylase deficiency in a postmenopausal woman.

  13. Prostaglandin E2 stimulates S100A8 expression by activating protein kinase A and CCAAT/enhancer-binding-protein-beta in prostate cancer cells.

    Science.gov (United States)

    Miao, Lin; Grebhardt, Sina; Shi, Jiandang; Peipe, Isabelle; Zhang, Ju; Mayer, Doris

    2012-11-01

    S100A8 and S100A9 are strongly expressed in epithelial cells of human prostate cancer. However, the regulation of their expression is unclear. Here we show that S100A8 and to a lesser extent S100A9 mRNA expression is induced by prostaglandin E2 in a dose and time-dependent manner in PC-3 prostate cancer cells as well as in BPH-1 benign prostatic epithelial cells. Prostanoid receptor EP2 antagonist AH6809 and EP4 antagonist AH23848, as well as protein kinase A inhibitor H89, inhibited prostaglandin E2 mediated increase in S100A8 mRNA expression as well as promoter activity. Sequence analysis detected a potential binding site of the transcription factor CCAAT/enhancer-binding-protein-beta within the proximal S100A8 promoter. CCAAT/enhancer-binding-protein-beta overexpression increased S100A8 mRNA and protein expression as well as its promoter activity. The latter was prevented by mutation of the potential CCAAT/enhancer-binding-protein-beta binding site within the S100A8 promoter. Chromatin immunoprecipitation revealed increased binding of CCAAT/enhancer-binding-protein-beta to the S100A8 promoter in prostaglandin E2 treated cells. Knockdown of CCAAT/enhancer-binding-protein-beta by siRNA blocked prostaglandin E2 mediated induction of S100A8 promoter activity and mRNA expression. Our results indicate that in prostate cancer cells, S100A8 expression is stimulated by prostaglandin E2 via EP2 and EP4 receptors through activation of the protein kinase A signaling pathway and subsequent stimulation of CCAAT/enhancer-binding-protein-beta binding to the S100A8 promoter.

  14. Overexpression of EB1 in human esophageal squamous cell carcinoma (ESCC) may promote cellular growth by activating beta-catenin/TCF pathway.

    Science.gov (United States)

    Wang, Yihua; Zhou, Xiaobo; Zhu, Hongxia; Liu, Shuang; Zhou, Cuiqi; Zhang, Guo; Xue, Liyan; Lu, Ning; Quan, Lanping; Bai, Jinfeng; Zhan, Qimin; Xu, Ningzhi

    2005-10-01

    Esophageal squamous cell carcinoma (ESCC) has a multifactorial etiology involving environmental and/or genetic factors. End-binding protein 1 (EB1), which was cloned as an interacting partner of the adenomatous polyposis coli (APC) tumor suppressor protein, was previously found overexpressed in ESCC. However, the precise role of EB1 in the development of this malignancy has not yet been elucidated. In this study, we analysed freshly resected ESCC specimens and demonstrated that EB1 was overexpressed in approximately 63% of tumor samples compared to matched normal tissue. We report that overexpression of EB1 in the ESCC line EC9706 significantly promotes cell growth, whereas suppression of EB1 protein level by RNA interference significantly inhibited growth of esophageal tumor cells. In addition, EB1 overexpression induced nuclear accumulation of beta-catenin and promoted the transcriptional activity of beta-catenin/T-cell factor (TCF). These effects were partially or completely abolished by coexpression of APC or DeltaN TCF4, respectively. Also, we found that EB1 affected the interaction between beta-catenin and APC. Furthermore, EB1 overexpression was correlated with cytoplasmic/nuclear accumulation of beta-catenin in primary human ESCC. Taken together, these results support the novel hypothesis that EB1 overexpression may play a role in the development of ESCC by affecting APC function and activating the beta-catenin/TCF pathway.

  15. The role of endo-beta-Mannanase activity in tomato seed germination.

    NARCIS (Netherlands)

    Toorop, P.E.

    1998-01-01

    The role of endo-β-mannanase activity in tomato seed germination was studied using the osmotic agent PEG 6000 and the plant hormones abscisic acid (ABA) and gibberellic acid. Endo-β-mannanase is known to degrade galactomannans in cell walls, and its activity was found in the lateral endosperm upon r

  16. Synthesis and biological activity of some heterocyclic compounds containing benzimidazole and beta-lactam moiety

    Indian Academy of Sciences (India)

    K F Ansari; C Lal

    2009-11-01

    A number of 1-substituted-2-methyl benzimidazole derivatives have been synthesized and tested for their antibacterial activities. The chemical structures of the newly synthesized compounds were verified on the basis of spectral and elemental methods of analyses. Investigation of antimicrobial activity of the compounds was done by disc diffusion method using Gram-positive (S. aureus, S. mutans and B. subtilis), Gram-negative (E. coli, S. typhi and P. aeruginosa) bacteria and fungi (C. albicans, A. flavus and A. niger). Among the compounds tested 5a, 5b, 5d, 5i, 5j and 5k exhibited good antibacterial activities against Gram positive bacteria, while 5d and 5i also showed notable antifungal activity. Specially compounds 5a and 5b exhibited appreciable activity against S. aureus and B. subtilis comparable to reference drugs.

  17. Beta-Glucosidase Activity in Paddy Soils of the Taihu Lake Region, China

    Institute of Scientific and Technical Information of China (English)

    WANG Xiao-Chang; LU Qin

    2006-01-01

    The profile distribution ofβ-gulcosidase activity in twelve typical paddy soil profiles with high productivity in the Taihu Lake region of China were investigated. Activities ofβ-gulcosidase in the plow layers were in the range of 52.68-137.02μg PNP g-1 soil h-1 with a mean of 89.22μg PNP g-1 soil h-1. However, most plow layers ranged from 70 to 110μg PNP g-1 soil h-1. The profile distribution of β-gulcosidase activity in the 12 soil profiles decreased rapidly with soil depth, with activity at the 60 cm depth only about 10% of that in the surface layers (0-15 cm or 0-20 cm). In these soil profiles, β-gulcosidase activity was significantly positively correlated with soil organic carbon and arylsulphatase activity.Meanwhile, a significantly negative correlation was shown betweenβ-gulcosidase activity and soil pH.

  18. Evidence for the presence of both peroxisome proliferator-activated receptors alpha and beta in the rat spinal cord.

    Science.gov (United States)

    Benani, A; Krémarik-Bouillaud, P; Bianchi, A; Netter, P; Minn, A; Dauça, M

    2003-01-01

    Peroxisome proliferator-activated receptors (PPARs) are ligand-activated transcription factors belonging to the nuclear receptor superfamily. Different subtypes of PPARs (alpha, beta, and gamma) have been described. Their distinct physiological functions depend on their differential ligand activation profiles but also on their specific tissue expression. Previous studies have described their presence in the central nervous system. However, their expression in the adult rat spinal cord in normal physiological conditions has never been investigated. We demonstrated by using reverse-transcription-polymerase chain reaction, and Western blotting, the mRNA and protein expression of PPARalpha and PPARbeta, but not PPARgamma in cervical, thoracic, and lumbar segments of the spinal cord. Using immunohistochemistry, we also showed for the first time the specific cellular distribution of these transcription factors in the different segments of the spinal cord. In the gray matter, the distribution of PPARalpha was homogenous whereas PPARbeta was specifically localized in motoneurons and in medial part of laminae IV, V, VI, VII, VIII, and X. These latter areas are known as nociceptive afferent pathways to supra-spinal structures such as the medulla reticular nucleus and the thalamus. In the white matter, PPARalpha was localized exclusively in astrocytes while PPARbeta was present in oligodendrocytes. The possible functions of PPARalpha and PPARbeta expressed in both white and gray matters of the spinal cord will be discussed but need further studies.

  19. Effects of dietary bran and the colon carcinogen 1,2-dimethylhydrazine on faecal. beta. -glucuronidase activity in mice

    Energy Technology Data Exchange (ETDEWEB)

    London, J.F.; Clapp, N.K.; Henke, M.A.

    1981-01-01

    To evaluate the physiological changes that might provide either mechanistic or prognostic information in colon carcinogenesis, we treated 8-wk-old male BALB/c mice with semisynthetic bran diets containing 20% by weight of either soya bean, winter wheat, or corn bran and gave ten weekly injections (from age 11 to 21 wk) of 20 mg 1,2-dimethylhydrazine (DMH)/kg body weight. Appropriate controls were included. Faecal samples were collected 11 to 13 wk after completion of DMH treatment and after 24 to 26 wk of continuous bran diet feeding. Daily faecal ..beta..-glucuronidase activity fluctuations were observed, but these were not statistically significant. Faecal enzyme activity varied depending upon the type of bran diet (control > wheat > soya bean > corn). DMH generally depressed faecal enzyme activity to a statistically significant degree (P < 0.03). These results demonstrate the persistent enzyme alterations produced by DMH and the assay's sensitivity for detecting such change. Further, the effects of diet suggest that dietary brans cause physiological changes that have the potential to modify colon carcinogenesis.

  20. The Relationship Between Beta Endorphins and Emotional State in Physically Active Individuals Aged 45-55 (A Report on a Pilot Study)

    OpenAIRE

    Kundziņa Ieva; Grants Juris

    2014-01-01

    Introduction. This sports-science-related article heavily relies on studies that have reported an increase in beta-endorphin (â-EP) concentration in plasma in response to physical activity. It examines the psychological and physiological effects of physical activity and exercise and reports on a research-experiment-based, endorphin-hypotheses-related pilot study aimed at exploring mood-related â-EP effects occurring in physically active male and female individuals aged 45-55 in response to ph...

  1. Estrogen-2-hydroxylase in the brain of the male African catfish, Clarias gariepinus

    Energy Technology Data Exchange (ETDEWEB)

    Timmers, R.J.; Granneman, J.C.; Lambert, J.G.; van Oordt, P.G.

    1988-11-01

    Estrogen-2-hydroxylase activity, involved in the biosynthesis of catecholestrogens, was localized in the brain of the male African catfish, Clarias gariepinus, by means of a radiometric assay using (2-TH)estradiol as substrate. Fore- and midbrain were divided in 18, 500-microns thick, transverse sections from which small defined areas were punched out and assayed. The estrogen-2-hydroxylase activity was calculated from the release of tritium during hydroxylation, and expressed in femtomole catecholestradiol.milligram-1 tissue.hour-1. The enzyme could be demonstrated throughout the brain. A high activity (greater than 350 fmol) was observed in the telencephalon, in particularly the rostral part and the area ventralis pars dorsalis; in the diencephalon in the preoptic region, including the magnocellular part of the preoptic nucleus and the rostral part of the anterior periventricular nucleus; and in the area tuberalis, including the nucleus lateralis tuberis, the rostral part of the nucleus anterior tuberis, the caudal part of the nucleus posterior periventricularis, and in the nucleus recessus posterioris. Also a high activity was detected in the mesencephalic tectum opticum and the dorsolateral part of the torus semicircularis. The ventral mesencephalon showed a moderate (200-350 fmol) to low (less than 200 fmol) activity, whereas the lowest activity was found in the hindbrain (118 fmol). The significance of the biosynthesis of catecholestrogens in the brain is discussed in light of the negative feedback mechanism of gonadal steroids on gonadotropin release.

  2. Receptor Density Is Key to the Alpha2/Beta Interferon Differential Activities

    OpenAIRE

    Moraga, I.; Harari, D.; Schreiber, G.; Uze, G.; Pellegrini, S.

    2009-01-01

    Multiple type I interferons (IFN-α/β) elicit Jak/Stat activation, rapid gene induction, and pleiotropic effects, such as differentiation, antiviral protection, and blocks in proliferation, which are dependent on the IFN subtype and the cellular context. To date, ligand- and receptor-specific molecular determinants underlying IFN-α/β differential activities or potencies have been well characterized. To analyze cellular determinants that impact subtype-specific potency, human fibrosarcoma U5A-d...

  3. Correlation between expression of 1α-hydroxylase and hypocalcaemia in rats with severe pancreatitis

    Institute of Scientific and Technical Information of China (English)

    Ping Zhou; Li Chang; Xiao-Hong Zhang; You-Dai Chen; Xuan-Lin Feng; Lei Deng; Jian-Dong Wang

    2015-01-01

    at 3 h, 6 h and 12 h (r=0.976,P<0.001;r=0.948,P<0.001; r=0.742, P=0.001) and also positive correlation between the 1α-hydroxylase expression and serum 1, 25 dihydroxy vitamin D3 at 1 h,3 h, 6 h and 12 h (r=0.935,P<0.001;r=0.952,P<0.001;r=0.917,P<0.001; r=0.874, P<0.001).Conclusions:At the early stage of the kidney injury, the expression of 1α-hydroxylase in the kidney tissue is reduced with the progress of the disease and the decrease in its activity has a correlation with the hypocalcaemia.

  4. Beta 2-adrenergic receptor activation enhances neurogenesis in Alzheimer’s disease mice

    Institute of Scientific and Technical Information of China (English)

    Gao-shang Chai; Yang-yang Wang; Amina Yasheng; Peng Zhao

    2016-01-01

    Impaired hippocampal neurogenesis is one of the early pathological features of Alzheimer’s disease. Enhancing adult hippocampal neuro-genesis has been pursued as a potential therapeutic strategy for Alzheimer’s disease. Recent studies have demonstrated that environmental novelty activates β2-adrenergic signaling and prevents the memory impairment induced by amyloid-β oligomers. Here, we hypothesized that β2-adrenoceptor activation would enhance neurogenesis and ameliorate memory deifcits in Alzheimer’s disease. To test this hypothe-sis, we investigated the effects and mechanisms of action of β2-adrenoceptor activation on neurogenesis and memory in amyloid precursor protein/presenilin 1 (APP/PS1) mice using the agonist clenbuterol (intraperitoneal injection, 2 mg/kg). We found that β2-adrenoceptor ac-tivation enhanced hippocampal neurogenesis, ameliorated memory deifcits, and increased dendritic branching and the density of dendritic spines. hTese effects were associated with the upregulation of postsynaptic density 95, synapsin 1 and synaptophysin in APP/PS1 mice. Furthermore, β2-adrenoceptor activation decreased cerebral amyloid plaques by decreasing APP phosphorylation at hTr668. hTese ifndings suggest that β2-adrenoceptor activation enhances neurogenesis and ameliorates memory deifcits in APP/PS1 mice.

  5. Beta-hexosaminidase activity of the oral pathogen Tannerella forsythia influences biofilm formation on glycoprotein substrates.

    Science.gov (United States)

    Roy, Sumita; Phansopa, Chatchawal; Stafford, Prachi; Honma, Kiyonobu; Douglas, C W Ian; Sharma, Ashu; Stafford, Graham P

    2012-06-01

    Tannerella forsythia is an important pathogen in periodontal disease. Previously, we showed that its sialidase activity is key to utilization of sialic acid from a range of human glycoproteins for biofilm growth and initial adhesion. Removal of terminal sialic acid residues often exposes β-linked glucosamine or galactosamine, which may also be important adhesive molecules. In turn, these residues are often removed by a group of enzymes known as β-hexosaminidases. We show here that T. forsythia has the ability to cleave glucosamine and galactosamine from model substrates and that this activity can be inhibited by the hexosaminidase inhibitor PugNAc (O-(2-acetamido-2-deoxy-d-glucopyranosylidene)amino N-phenyl carbamate). We now demonstrate for the first time that β-hexosaminidase activity plays a role in biofilm growth on glycoprotein-coated surfaces because biofilm growth and initial cell adhesion are inhibited by PugNAc. In contrast, adhesion to siallo-glycoprotein-coated surfaces is unaltered by PugNAc in the absence of sialidase activity (using a sialidase-deficient mutant) or surprisingly on the clinically relevant substrates saliva or serum. These data indicate that β-hexosaminidase activity has a significant role in biofilm formation in combination with sialidase activity in the biofilm lifestyle of T. forsythia.

  6. Crystal Structure of Full-length Mycobacterium tuberculosis H37Rv Glycogen Branching Enzyme; Insights of N-Terminal [beta]-Sandwich in Sustrate Specifity and Enzymatic Activity

    Energy Technology Data Exchange (ETDEWEB)

    Pal, Kuntal; Kumar, Shiva; Sharma, Shikha; Garg, Saurabh Kumar; Alam, Mohammad Suhail; Xu, H. Eric; Agrawal, Pushpa; Swaminathan, Kunchithapadam (NU Sinapore); (Van Andel); (IMT-India)

    2010-07-13

    The open reading frame Rv1326c of Mycobacterium tuberculosis (Mtb) H37Rv encodes for an {alpha}-1,4-glucan branching enzyme (MtbGlgB, EC 2.4.1.18, Uniprot entry Q10625). This enzyme belongs to glycoside hydrolase (GH) family 13 and catalyzes the branching of a linear glucose chain during glycogenesis by cleaving a 1 {yields} 4 bond and making a new 1 {yields} 6 bond. Here, we show the crystal structure of full-length MtbGlgB (MtbGlgBWT) at 2.33-{angstrom} resolution. MtbGlgBWT contains four domains: N1 {beta}-sandwich, N2 {beta}-sandwich, a central ({beta}/{alpha}){sub 8} domain that houses the catalytic site, and a C-terminal {beta}-sandwich. We have assayed the amylase activity with amylose and starch as substrates and the glycogen branching activity using amylose as a substrate for MtbGlgBWT and the N1 domain-deleted (the first 108 residues deleted) Mtb{Delta}108GlgB protein. The N1 {beta}-sandwich, which is formed by the first 105 amino acids and superimposes well with the N2 {beta}-sandwich, is shown to have an influence in substrate binding in the amylase assay. Also, we have checked and shown that several GH13 family inhibitors are ineffective against MtbGlgBWT and Mtb{Delta}108GlgB. We propose a two-step reaction mechanism, for the amylase activity (1 {yields} 4 bond breakage) and isomerization (1 {yields} 6 bond formation), which occurs in the same catalytic pocket. The structural and functional properties of MtbGlgB and Mtb{Delta}108GlgB are compared with those of the N-terminal 112-amino acid-deleted Escherichia coli GlgB (EC{Delta}112GlgB).

  7. Structural features of the regulatory ACT domain of phenylalanine hydroxylase.

    Directory of Open Access Journals (Sweden)

    Carla Carluccio

    Full Text Available Phenylalanine hydroxylase (PAH catalyzes the conversion of L-Phe to L-Tyr. Defects in PAH activity, caused by mutations in the human gene, result in the autosomal recessively inherited disease hyperphenylalaninemia. PAH activity is regulated by multiple factors, including phosphorylation and ligand binding. In particular, PAH displays positive cooperativity for L-Phe, which is proposed to bind the enzyme on an allosteric site in the N-terminal regulatory domain (RD, also classified as an ACT domain. This domain is found in several proteins and is able to bind amino acids. We used molecular dynamics simulations to obtain dynamical and structural insights into the isolated RD of PAH. Here we show that the principal motions involve conformational changes leading from an initial open to a final closed domain structure. The global intrinsic motions of the RD are correlated with exposure to solvent of a hydrophobic surface, which corresponds to the ligand binding-site of the ACT domain. Our results strongly suggest a relationship between the Phe-binding function and the overall dynamic behaviour of the enzyme. This relationship may be affected by structure-disturbing mutations. To elucidate the functional implications of the mutations, we investigated the structural effects on the dynamics of the human RD PAH induced by six missense hyperphenylalaninemia-causing mutations, namely p.G46S, p.F39C, p.F39L, p.I65S, p.I65T and p.I65V. These studies showed that the alterations in RD hydrophobic interactions induced by missense mutations could affect the functionality of the whole enzyme.

  8. Structural features of the regulatory ACT domain of phenylalanine hydroxylase.

    Science.gov (United States)

    Carluccio, Carla; Fraternali, Franca; Salvatore, Francesco; Fornili, Arianna; Zagari, Adriana

    2013-01-01

    Phenylalanine hydroxylase (PAH) catalyzes the conversion of L-Phe to L-Tyr. Defects in PAH activity, caused by mutations in the human gene, result in the autosomal recessively inherited disease hyperphenylalaninemia. PAH activity is regulated by multiple factors, including phosphorylation and ligand binding. In particular, PAH displays positive cooperativity for L-Phe, which is proposed to bind the enzyme on an allosteric site in the N-terminal regulatory domain (RD), also classified as an ACT domain. This domain is found in several proteins and is able to bind amino acids. We used molecular dynamics simulations to obtain dynamical and structural insights into the isolated RD of PAH. Here we show that the principal motions involve conformational changes leading from an initial open to a final closed domain structure. The global intrinsic motions of the RD are correlated with exposure to solvent of a hydrophobic surface, which corresponds to the ligand binding-site of the ACT domain. Our results strongly suggest a relationship between the Phe-binding function and the overall dynamic behaviour of the enzyme. This relationship may be affected by structure-disturbing mutations. To elucidate the functional implications of the mutations, we investigated the structural effects on the dynamics of the human RD PAH induced by six missense hyperphenylalaninemia-causing mutations, namely p.G46S, p.F39C, p.F39L, p.I65S, p.I65T and p.I65V. These studies showed that the alterations in RD hydrophobic interactions induced by missense mutations could affect the functionality of the whole enzyme.

  9. Synthesis and antibacterial activities of new 1 beta-methylcarbapenems having a 1,3-diazabicyclo[3.3.0]octan-2,4-dione moiety.

    Science.gov (United States)

    Nam, K H; Oh, C H; Ham, Y W; Lee, K S; Cho, J H

    1997-08-01

    The synthesis of a new series of 1 beta-methylcarbapenems having a 1,3-diazabicyclo[3.3.0]octane-2,4-dione moiety is described. Their in vitro antibacterial activities against both Gram-positive and Gram-negative bateria are determined and the effect of substituent on the bicyclic ring as well as stereoisomerism was investigated.

  10. Characterization of paired mucoid/non-mucoid Pseudomonas aeruginosa isolates from Danish cystic fibrosis patients: antibiotic resistance, beta-lactamase activity and RiboPrinting

    DEFF Research Database (Denmark)

    Ciofu, O; Fussing, V; Bagge, N;

    2001-01-01

    The purpose of this study was to characterize 42 paired mucoid and non-mucoid Danish cystic fibrosis (CF) Pseudomonas aeruginosa isolates collected in 1997, by RiboPrinting, antibiotic susceptibility and beta-lactamase activity. Eight P. aeruginosa isolates collected before 1991 were included for...

  11. Adrenergic receptors and gastric secretion in dogs. Is a "tonic balance" relationship between vagal and beta 2-adrenergic activity a possibility?

    DEFF Research Database (Denmark)

    Gottrup, F; Hovendal, C; Bech, K

    1984-01-01

    The relative influence of adrenergic receptors on gastric acid secretion in the dog stomach with different vagal activity or "tone" is almost unknown. beta-adrenoceptors seem to be most important for the direct effect of adrenergic stimulation on acid secretion. In this study the effects of vagot...

  12. Synthesis and biological evaluation of beta-chloro vinyl chalcones as inhibitors of TNF-alpha and IL-6 with antimicrobial activity.

    Science.gov (United States)

    Bandgar, Babasaheb P; Patil, Sachin A; Korbad, Balaji L; Nile, Shivraj H; Khobragade, Chandrahase N

    2010-06-01

    A series of beta-chloro vinyl chalcones have been synthesized by Claisen-Schmidt condensation. beta-chloro vinyl aldehyde has been synthesized by the Vilsmayer-Hack formylation reaction. The structures of the newly synthesized compounds were confirmed by 1H NMR, IR and Mass spectral analysis. All the compounds were evaluated for their anti-inflammatory activity (against TNF-alpha and IL-6) and antimicrobial (antibacterial and antifungal) activity. Compounds 5a, 5d, 5e, 5g and 5i exhibited promising activity against IL-6 with 58-83% inhibition at 10 microM concentration. None of the compound was found to be cytotoxic in CCK-8 cells at 10 microM concentration. Whereas compounds 5b, 5d, 5e and 5i showed very good antibacterial activity and compounds 5a, 5b, 5e and 5i showed good antifungal activity.

  13. Partial agonist and antagonist activities of a mutant scorpion beta-toxin on sodium channels.

    Science.gov (United States)

    Karbat, Izhar; Ilan, Nitza; Zhang, Joel Z; Cohen, Lior; Kahn, Roy; Benveniste, Morris; Scheuer, Todd; Catterall, William A; Gordon, Dalia; Gurevitz, Michael

    2010-10-01

    Scorpion β-toxin 4 from Centruroides suffusus suffusus (Css4) enhances the activation of voltage-gated sodium channels through a voltage sensor trapping mechanism by binding the activated state of the voltage sensor in domain II and stabilizing it in its activated conformation. Here we describe the antagonist and partial agonist properties of a mutant derivative of this toxin. Substitution of seven different amino acid residues for Glu(15) in Css4 yielded toxin derivatives with both increased and decreased affinities for binding to neurotoxin receptor site 4 on sodium channels. Css4(E15R) is unique among this set of mutants in that it retained nearly normal binding affinity but lost its functional activity for modification of sodium channel gating in our standard electrophysiological assay for voltage sensor trapping. More detailed analysis of the functional effects of Css4(E15R) revealed weak voltage sensor trapping activity, which was very rapidly reversed upon repolarization and therefore was not observed in our standard assay of toxin effects. This partial agonist activity of Css4(E15R) is observed clearly in voltage sensor trapping assays with brief (5 ms) repolarization between the conditioning prepulse and the test pulse. The effects of Css4(E15R) are fit well by a three-step model of toxin action involving concentration-dependent toxin binding to its receptor site followed by depolarization-dependent activation of the voltage sensor and subsequent voltage sensor trapping. Because it is a partial agonist with much reduced efficacy for voltage sensor trapping, Css4(E15R) can antagonize the effects of wild-type Css4 on sodium channel activation and can prevent paralysis by Css4 when injected into mice. Our results define the first partial agonist and antagonist activities for scorpion toxins and open new avenues of research toward better understanding of the structure-function relationships for toxin action on sodium channel voltage sensors and toward

  14. Activation of the Wnt/{beta}-catenin signaling pathway is associated with glial proliferation in the adult spinal cord of ALS transgenic mice

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Yanchun [Department of Histology and Embryology, Weifang Medical University, Weifang, Shandong (China); Department of Histology and Embryology, Shandong University School of Medicine, Jinan, Shandong (China); Guan, Yingjun, E-mail: guanyj@wfmc.edu.cn [Department of Histology and Embryology, Weifang Medical University, Weifang, Shandong (China); Department of Histology and Embryology, Shandong University School of Medicine, Jinan, Shandong (China); Liu, Huancai [Department of Orthopedic, Affiliated Hospital, Weifang Medical University, Weifang, Shandong (China); Wu, Xin; Yu, Li; Wang, Shanshan; Zhao, Chunyan; Du, Hongmei [Department of Histology and Embryology, Weifang Medical University, Weifang, Shandong (China); Wang, Xin, E-mail: xwang@rics.bwh.harvard.edu [Department of Neurosurgery, Brigham and Women' s Hospital, Harvard Medical School, Boston, MA (United States)

    2012-04-06

    Highlights: Black-Right-Pointing-Pointer Wnt3a and Cyclin D1 were upregulated in the spinal cord of the ALS mice. Black-Right-Pointing-Pointer {beta}-catenin translocated from the cell membrane to the nucleus in the ALS mice. Black-Right-Pointing-Pointer Wnt3a, {beta}-catenin and Cyclin D1 co-localized for astrocytes were all increased. Black-Right-Pointing-Pointer BrdU/Cyclin D1 double-positive cells were increased in the spinal cord of ALS mice. Black-Right-Pointing-Pointer BrdU/Cyclin D1/GFAP triple-positive cells were detected in the ALS mice. -- Abstract: Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease characterized by the progressive and fatal loss of motor neurons. In ALS, there is a significant cell proliferation in response to neurodegeneration; however, the exact molecular mechanisms of cell proliferation and differentiation are unclear. The Wnt signaling pathway has been shown to be involved in neurodegenerative processes. Wnt3a, {beta}-catenin, and Cyclin D1 are three key signaling molecules of the Wnt/{beta}-catenin signaling pathway. We determined the expression of Wnt3a, {beta}-catenin, and Cyclin D1 in the adult spinal cord of SOD1{sup G93A} ALS transgenic mice at different stages by RT-PCR, Western blot, and immunofluorescence labeling techniques. We found that the mRNA and protein of Wnt3a and Cyclin D1 in the spinal cord of the ALS mice were upregulated compared to those in wild-type mice. In addition, {beta}-catenin translocated from the cell membrane to the nucleus and subsequently activated transcription of the target gene, Cyclin D1. BrdU and Cyclin D1 double-positive cells were increased in the spinal cord of these mice. Moreover, Wnt3a, {beta}-catenin, and Cyclin D1 were also expressed in both neurons and astrocytes. The expression of Wnt3a, {beta}-catenin or Cyclin D1 in mature GFAP{sup +} astrocytes increased. Moreover, BrdU/Cyclin D1/GFAP triple-positive cells were detected in the ALS mice. Our findings suggest that

  15. Therapeutic treatment with a novel hypoxia-inducible factor hydroxylase inhibitor (TRC160334 ameliorates murine colitis

    Directory of Open Access Journals (Sweden)

    Gupta R

    2014-01-01

    Full Text Available Ram Gupta,1 Anita R Chaudhary,2 Binita N Shah,1 Avinash V Jadhav,3 Shitalkumar P Zambad,1 Ramesh Chandra Gupta,4 Shailesh Deshpande,4 Vijay Chauthaiwale,4 Chaitanya Dutt4 1Department of Pharmacology, 2Cellular and Molecular Biology, 3Preclinical Safety Evaluation, 4Discovery, Torrent Research Centre, Torrent Pharmaceuticals Ltd, Gandhinagar, Gujarat, India Background and aim: Mucosal healing in inflammatory bowel disease (IBD can be achieved by improvement of intestinal barrier protection. Activation of hypoxia-inducible factor (HIF has been identified as a critical factor for barrier protection during mucosal insult and is linked with improvement in symptoms of colitis. Although prophylactic efficacy of HIF hydroxylase inhibitors in murine colitis have been established, its therapeutic efficacy in clinically relevant therapeutic settings have not been established. In the present study we aim to establish therapeutic efficacy of TRC160334, a novel HIF hydroxylase inhibitor, in animal models of colitis. Methods: The efficacy of TRC160334 was evaluated in two different mouse models of colitis by oral route. A prophylactic efficacy study was performed in a 2,4,6-trinitrobenzene sulfonic acid-induced mouse model of colitis representing human Crohn's disease pathology. Additionally, a therapeutic efficacy study was performed in a dextran sulfate sodium-induced mouse model of colitis, a model simulating human ulcerative colitis. Results: TRC160334 treatment resulted in significant improvement in disease end points in both models of colitis. TRC160334 treatment resulted into cytoprotective heatshock protein 70 induction in inflamed colon. TRC160334 successfully attenuated the rate of fall in body weight, disease activity index, and macroscopic and microscopic scores of colonic damage leading to overall improvement in study outcome. Conclusion: Our findings are the first to demonstrate that therapeutic intervention with a HIF hydroxylase inhibitor

  16. Identification, expression and activity analyses of five novel duck beta-defensins.

    Directory of Open Access Journals (Sweden)

    Deying Ma

    Full Text Available In the current study, five novel avian β-defensins (AvBDs were identified and characterized in tissues from Peking ducks (Anas platyrhynchos. The nucleotide sequences of these cDNAs comprised 198 bp, 182 bp, 201 bp, 204 bp, and 168 bp, and encoded 65, 60, 66, 67, and 55 amino acids, respectively. Homology, characterization and comparison of these genes with AvBD from other avian species confirmed that they were Apl_AvBD1, 3, 5, 6, and 16. Recombinant AvBDs were produced and purified by expressing these genes in Escherichia coli. In addition, peptides were synthesized according to the respective AvBD sequences. Investigation of the antibacterial activity of the Apl_AvBDs showed that all of them exhibited antibacterial activity against all 12 bacteria investigated (P<0.05 or P<0.01. In addition, the antibacterial activity of all of the AvBDs against M. tetragenus and P. multocida decreased significantly in the presence of 150 mM NaCl (P<0.01. None of the AvBDs showed hemolytic activity. Consistent with their broad-spectrum antibacterial activity, the five novel Apl_AvBDs inhibited replication of duck hepatitis virus (DHV in vitro significantly (P<0.05. The mRNA expression of all five Apl_AvBD in most tissues, including immune organs and the liver, was upregulated in response to DHV infection at different time points. These findings provide evidence that these defensins activate the immune response to combat microbial infection.

  17. Signal transducer and activator of transcription 5 activation is sufficient to drive transcriptional induction of cyclin D2 gene and proliferation of rat pancreatic beta-cells

    DEFF Research Database (Denmark)

    Friedrichsen, Birgitte N; Richter, Henrijette E; Hansen, Johnny A

    2003-01-01

    in a time-dependent manner by hGH in INS-1 cells. Inhibition of protein synthesis by coincubation with cycloheximide did not affect the hGH-induced increase of cyclin D2 mRNA levels at 4 h. Expression of a dominant negative STAT5 mutant, STAT5aDelta749, partially inhibited cyclin D2 protein levels. INS-1...... cells and hGH-induced increase of mRNA-levels of the cell cycle regulator cyclin D2. In this study we have further characterized the role of STAT5 in the regulation of cyclin D expression and beta-cell proliferation by hGH. Cyclin D2 mRNA and protein levels (but not cyclin D1 and D3) were induced......-STAT5b stimulated transcriptional activation of the cyclin D2 promoter and induced hGH-independent proliferation in these cells. In primary beta-cells, adenovirus-mediated expression of CA-STAT5b profoundly stimulated DNA-synthesis (5.3-fold over control) in the absence of hGH. Our studies indicate...

  18. Expression and characterization of recombinant single-chain salmon class I MHC fused with beta2-microglobulin with biological activity

    DEFF Research Database (Denmark)

    Zhao, Heng; Stet, René J M; Skjødt, Karsten;

    2008-01-01

    Heterodimeric class I major histocompatibility complex (MHC) molecules consist of a putative 45-kDa heavy chain and a 12-kDa beta2-microglobulin (beta2m) light chain. The knowledge about MHC genes in Atlantic salmon accumulated during the last decade has allowed us to generate soluble and stable ...

  19. Purification and biochemical characterization of the complete structure of a proteolytically modified beta-2-microglobulin with biological activity

    DEFF Research Database (Denmark)

    Nissen, Mogens Holst; Thim, L; Christensen, M

    1987-01-01

    A modified form of beta-2-microglobulin (beta-2-m) has previously been described to be present in serum from patients suffering from autoimmune diseases, acquired immune deficiency syndrome and small-cell lung cancer [Plesner, T. and Wiik, A. (1979) Scand. J. Immunol. 9, 247-254; Bhalla et al. (1...

  20. Lithium chloride ameliorates learning and memory ability and inhibits glycogen synthase kinase-3 beta activity in a mouse model of fragile X syndrome

    Institute of Scientific and Technical Information of China (English)

    Shengqiang Chen; Xuegang Luo; Quan Yang; Weiwen Sun; Kaiyi Cao; Xi Chen; Yueling Huang; Lijun Dai; Yonghong Yi

    2011-01-01

    In the present study, Fmr1 knockout mice (KO mice) were used as the model for fragile X syndrome. The results of step-through and step-down tests demonstrated that Fmr1 KO mice had shorter latencies and more error counts, indicating a learning and memory disorder. After treatment with 30, 60, 90, 120, or 200 mg/kg lithium chloride, the learning and memory abilities of the Fmr1 KO mice were significantly ameliorated, in particular, the 200 mg/kg lithium chloride treatment had the most significant effect. Western blot analysis showed that lithium chloride significantly enhanced the expression of phosphorylated glycogen synthase kinase 3 beta, an inactive form of glycogen synthase kinase 3 beta, in the cerebral cortex and hippocampus of the Fmr1 KO mice. These results indicated that lithium chloride improved learning and memory in the Fmr1 KO mice, possibly by inhibiting glycogen synthase kinase 3 beta activity.

  1. Predominant alpha2/beta2/gamma3 AMPK activation during exercise in human skeletal muscle

    DEFF Research Database (Denmark)

    Birk, Jesper Bratz; Wojtaszewski, Jørgen

    2006-01-01

    5'AMP-activated protein kinase (AMPK) is a key regulator of cellular metabolism and is regulated in muscle during exercise. We have previously established that only three of 12 possible AMPK a/ß/¿-heterotrimers are present in human skeletal muscle. Previous studies describe discrepancies between ...

  2. A role for Peroxisome Proliferator-Activated Receptor Beta in T cell development

    Science.gov (United States)

    Mothe-Satney, Isabelle; Murdaca, Joseph; Sibille, Brigitte; Rousseau, Anne-Sophie; Squillace, Raphaëlle; Le Menn, Gwenaëlle; Rekima, Akila; Larbret, Frederic; Pelé, Juline; Verhasselt, Valérie; Grimaldi, Paul A.; Neels, Jaap G.

    2016-01-01

    Metabolism plays an important role in T cell biology and changes in metabolism drive T cell differentiation and fate. Most research on the role of metabolism in T lymphocytes focuses on mature T cells while only few studies have investigated the role of metabolism in T cell development. In this study, we report that activation or overexpression of the transcription factor Peroxisome Proliferator-Activated Receptor β (PPARβ) increases fatty acid oxidation in T cells. Furthermore, using both in vivo and in vitro models, we demonstrate that PPARβ activation/overexpression inhibits thymic T cell development by decreasing proliferation of CD4−CD8− double-negative stage 4 (DN4) thymocytes. These results support a model where PPARβ activation/overexpression favours fatty acid- instead of glucose-oxidation in developing T cells, thereby hampering the proliferative burst normally occurring at the DN4 stage of T cell development. As a consequence, the αβ T cells that are derived from DN4 thymocytes are dramatically decreased in peripheral lymphoid tissues, while the γδ T cell population remains untouched. This is the first report of a direct role for a member of the PPAR family of nuclear receptors in the development of T cells. PMID:27680392

  3. Vagus Nerve Activity Augments Intestinal Macrophage Phagocytosis via Nicotinic Acetylcholine Receptor alpha 4 beta 2

    NARCIS (Netherlands)

    van der Zanden, Esmerij P.; Snoek, Susanne A.; Heinsbroek, Sigrid E.; Stanisor, Oana I.; Verseijden, Caroline; Boeckxstaens, Guy E.; Peppelenbosch, Maikel P.; Greaves, David R.; Gordon, Siamon; de Jonge, Wouter J.

    2009-01-01

    BACKGROUND & AIMS: The vagus nerve negatively regulates macrophage cytokine production via the release of acetylcholine (ACh) and activation of nicotinic acetylcholine receptors (nAChR). In various models of intestinal inflammation, vagus nerve efferent stimulation ameliorates disease. Given the act

  4. Modulation of Beta-catenin Activity with PKD1 in Prostate Cancer

    Science.gov (United States)

    2012-04-01

    2010 initiative), NIH (NCI RO1, NCRR COBRE ) and pharmaceutical industries (Merck Pharmaceuticals, Investigator Initiated Grant). 15. SUBJECT TERMS... COBRE ) and pharmaceutical industries (Merck Pharmaceuticals, Investigator Initiated Grant). 7 BODY - Aim 1: Molecular Nature of PKD1 and β-catenin...activating LIM kinase (LIMK). 22 from the state (Governor’s 2010 initiative), NIH (NCI RO1, NCRR COBRE ) and pharmaceutical industries (Merck

  5. [Dialkylmethyl beta-glycosides of N-acetylmuramyl-L-alanyl-D-isoglutamine: synthesis and infection protective and cytotoxic activities].

    Science.gov (United States)

    Zemliakov, A E; Tsikalova, V N; Tsikalov, V V; Chirva, V Ia; Mulik, E L; Kuzovlev, F N; Kaliuzhin, O V; Kiselevskií, M V

    2008-01-01

    Symmetric secondary linear alcohols were proposed as aglycones for the synthesis of lipophilic beta-glycosides of N-acetylmuramyl-L-alanyl-D-isoglutamine (MDP). Pentadecan-8-ol, nonadecan-10-ol, and tricosan-12-ol were glycosylated by the oxazoline method. Based on the corresponding glucosaminides, alkyl beta-glycosides of 4,6-O-isopropylidene-N-acetylmuramic acid were synthesized and coupled with the dipeptide. Deprotection of isopropylidene groups by acidic hydrolysis and catalytic hydrogenolysis of benzyl esters resulted in the target muramyldipeptide glycosides. Nonadecan-10-yl and tricosan-12-yl [beta]-MDPs at doses 2 microg/mice most effectively stimulated antibacterial resistance in mice against Staphylococcus aureus. In contrast to the previously synthesized undecan-6-yl beta-MDP, pentadecan-8-yl, nonadecan-10-yl, and tricosan-12-yl beta-MDPs demonstrated direct cytotoxicity toward tumor cells E-562 and blood mononuclear cells.

  6. STAT5 activity in pancreatic beta-cells influences the severity of diabetes in animal models of type 1 and 2 diabetes

    DEFF Research Database (Denmark)

    Jackerott, Malene; Møldrup, Annette; Thams, Peter;

    2006-01-01

    Pancreatic beta-cell growth and survival and insulin production are stimulated by growth hormone and prolactin through activation of the transcription factor signal transducer and activator of transcription (STAT)5. To assess the role of STAT5 activity in beta-cells in vivo, we generated transgenic...... of glucose tolerance, whereas RIP-CASTAT5 mice were more glucose tolerant and less hyperleptinemic than wild-type mice. Although the pancreatic insulin content and relative beta-cell area were increased in high-fat diet-fed RIP-DNSTAT5 mice compared with wild-type or RIP-CASTAT5 mice, RIP-DNSTAT5 mice showed...... reduced beta-cell proliferation at 6 months of age. The inhibitory effect of high-fat diet or leptin on insulin secretion was diminished in isolated islets from RIP-DNSTAT5 mice compared with wild-type islets. Upon multiple low-dose streptozotocin treatment, RIP-DNSTAT5 mice exhibited higher plasma...

  7. Effects of osmotic stress on the activity of MAPKs and PDGFR-beta-mediated signal transduction in NIH-3T3 fibroblasts

    DEFF Research Database (Denmark)

    Nielsen, M-B; Christensen, Søren Tvorup; Hoffmann, E K

    2008-01-01

    in a serum- and nutrient-free inorganic medium (300 mosM) to analyze the effects of osmotic stress on MAPK activity and PDGF receptor (PDGFR)-beta-mediated signal transduction. We found that hypoosmolarity (cell swelling at 211 mosM) induced the phosphorylation and nuclear translocation of ERK1/2, most...... likely via a pathway independent of PDGFR-beta and MEK1/2. Conversely, hyperosmolarity (cell shrinkage at 582 mosM) moved nuclear and phosphorylated ERK1/2 to the cytoplasm and induced the phosphorylation and nuclear translocation of p38 and phosphorylation of JNK1/2. In a series of parallel experiments......, hypoosmolarity did not affect PDGF-BB-induced activation of PDGFR-beta, whereas hyperosmolarity strongly inhibited ligand-dependent PDGFR-beta activation as well as downstream mitogenic signal components of the receptor, including Akt and the MEK1/2-ERK1/2 pathway. Based on these results, we conclude that ligand...

  8. Unlike PPAR{gamma}, PPAR{alpha} or PPAR{beta}/{delta} activation does not promote human monocyte differentiation toward alternative macrophages

    Energy Technology Data Exchange (ETDEWEB)

    Bouhlel, Mohamed Amine [Univ Lille Nord de France, F-59000 Lille (France); Inserm U545, F-59000 Lille (France); UDSL, F-59000 Lille (France); Institut Pasteur de Lille, F-59019 Lille (France); Brozek, John [Genfit, Loos (France); Derudas, Bruno [Univ Lille Nord de France, F-59000 Lille (France); Inserm U545, F-59000 Lille (France); UDSL, F-59000 Lille (France); Institut Pasteur de Lille, F-59019 Lille (France); Zawadzki, Christophe; Jude, Brigitte [Inserm ERI-9 and Equipe d' Accueil 2693, IFR114, Universite de Lille, Lille (France); Staels, Bart, E-mail: bart.staels@pasteur-lille.fr [Univ Lille Nord de France, F-59000 Lille (France); Inserm U545, F-59000 Lille (France); UDSL, F-59000 Lille (France); Institut Pasteur de Lille, F-59019 Lille (France); Chinetti-Gbaguidi, Giulia [Univ Lille Nord de France, F-59000 Lille (France); Inserm U545, F-59000 Lille (France); UDSL, F-59000 Lille (France); Institut Pasteur de Lille, F-59019 Lille (France)

    2009-08-28

    Macrophages adapt their response to micro-environmental signals. While Th1 cytokines promote pro-inflammatory M1 macrophages, Th2 cytokines promote an 'alternative' anti-inflammatory M2 macrophage phenotype. Peroxisome proliferator-activated receptors (PPARs) are ligand-activated transcription factors expressed in macrophages where they control the inflammatory response. It has been shown that PPAR{gamma} promotes the differentiation of monocytes into anti-inflammatory M2 macrophages in humans and mice, while a role for PPAR{beta}/{delta} in this process has been reported only in mice and no data are available for PPAR{alpha}. Here, we show that in contrast to PPAR{gamma}, expression of PPAR{alpha} and PPAR{beta}/{delta} overall does not correlate with the expression of M2 markers in human atherosclerotic lesions, whereas a positive correlation with genes of lipid metabolism exists. Moreover, unlike PPAR{gamma}, PPAR{alpha} or PPAR{beta}/{delta} activation does not influence human monocyte differentiation into M2 macrophages in vitro. Thus, PPAR{alpha} and PPAR{beta}/{delta} do not appear to modulate the alternative differentiation of human macrophages.

  9. Dehydrogenase and Oxoreductase Activities of Porcine Placental 11Beta-Hydroxysteroid Dehydrogenase

    Science.gov (United States)

    2016-06-07

    Subsequently, samples were thawed and extracted with ethyl acetate to obtain tritiated steroids. These extracts were sub- jected to thin layer chromatography...containing .02 M EDTA (PBS) to remove most radio- activity. Tissue fragments were then homogenized in PBS and aliquots removed for DNA analysis (32). In...either 3H-cortisol or 3H-cortisone were used as substrate. Incubations were conducted as above-noted and DNA measures conducted. Statistical

  10. Association between Tryptophan Hydroxylase 2 Gene Polymorphism and Completed Suicide

    Science.gov (United States)

    Fudalej, Sylwia; Ilgen, Mark; Fudalej, Marcin; Kostrzewa, Grazyna; Barry, Kristen; Wojnar, Marcin; Krajewski, Pawel; Blow, Frederic; Ploski, Rafal

    2010-01-01

    The association between suicide and a single nucleotide polymorphism (rs1386483) was examined in the recently identified tryptophan hydroxylase 2 (TPH2) gene. Blood samples of 143 suicide victims and 162 age- and sex-matched controls were examined. The frequency of the TT genotype in the TPH2 polymorphism was higher in suicide victims than in…

  11. Recommendations for the nutrition management of phenylalanine hydroxylase deficiency.

    Science.gov (United States)

    Singh, Rani H; Rohr, Fran; Frazier, Dianne; Cunningham, Amy; Mofidi, Shideh; Ogata, Beth; Splett, Patricia L; Moseley, Kathryn; Huntington, Kathleen; Acosta, Phyllis B; Vockley, Jerry; Van Calcar, Sandra C

    2014-02-01

    The effectiveness of a phenylalanine-restricted diet to improve the outcome of individuals with phenylalanine hydroxylase deficiency (OMIM no. 261600) has been recognized since the first patients were treated 60 years ago. However, the treatment regime is complex, costly, and often difficult to maintain for the long term. Improvements and refinements in the diet for phenylalanine hydroxylase deficiency have been made over the years, and adjunctive therapies have proven to be successful for certain patients. Yet evidence-based guidelines for managing phenylalanine hydroxylase deficiency, optimizing outcomes, and addressing all available therapies are lacking. Thus, recommendations for nutrition management were developed using evidence from peer-reviewed publications, gray literature, and consensus surveys. The areas investigated included choice of appropriate medical foods, integration of adjunctive therapies, treatment during pregnancy, monitoring of nutritional and clinical markers, prevention of nutrient deficiencies, providing of access to care, and compliance strategies. This process has not only provided assessment and refinement of current nutrition management and monitoring recommendations but also charted a direction for future studies. This document serves as a companion to the concurrently published American College of Medical Genetics and Genomics guideline for the medical treatment of phenylalanine hydroxylase deficiency.

  12. Tetrahydrobiopterin-responsive phenylalanine hydroxylase deficiency in Dutch neonates

    NARCIS (Netherlands)

    Spaapen, LJM; Bakker, JA; Velter, C; Loots, W; Rubio-Gonzalbo, ME; Forget, PP; Dorland, L; De Koning, TJ; Poll-The, BT; Van Amstel, HKP; Bekhof, J; Blau, N; Duran, M

    2001-01-01

    Four neonates with a positive phenylalanine screening test (Phe concentrations between 258 and 1250 mu mol/L) were investigated further to differentiate between phenylalanine hydroxylase (PAH) deficiency and variant hyperphenylalaninaemia (HPA) forms. In patients 1 and 2 a tetrahydrobiopterin (BH4)

  13. Cloning, expression, purification and characterization of tryptophan hydroxylase variants

    DEFF Research Database (Denmark)

    Boesen, Jane

    Tryptophan hydroxylase (TPH) catalyzes the first and rate-limiting step in the biosynthesis of the neurotransmitter and hormone serotonin (5-hydroxytryptamine). Serotonin is involved in many physiological functions, such as appetite and sleep rhythm, as well as a wide range of psychiatric disorde...

  14. Therapeutic treatment with a novel hypoxia-inducible factor hydroxylase inhibitor (TRC160334) ameliorates murine colitis

    Science.gov (United States)

    Gupta, Ram; Chaudhary, Anita R; Shah, Binita N; Jadhav, Avinash V; Zambad, Shitalkumar P; Gupta, Ramesh Chandra; Deshpande, Shailesh; Chauthaiwale, Vijay; Dutt, Chaitanya

    2014-01-01

    Background and aim Mucosal healing in inflammatory bowel disease (IBD) can be achieved by improvement of intestinal barrier protection. Activation of hypoxia-inducible factor (HIF) has been identified as a critical factor for barrier protection during mucosal insult and is linked with improvement in symptoms of colitis. Although prophylactic efficacy of HIF hydroxylase inhibitors in murine colitis have been established, its therapeutic efficacy in clinically relevant therapeutic settings have not been established. In the present study we aim to establish therapeutic efficacy of TRC160334, a novel HIF hydroxylase inhibitor, in animal models of colitis. Methods The efficacy of TRC160334 was evaluated in two different mouse models of colitis by oral route. A prophylactic efficacy study was performed in a 2,4,6-trinitrobenzene sulfonic acid-induced mouse model of colitis representing human Crohn’s disease pathology. Additionally, a therapeutic efficacy study was performed in a dextran sulfate sodium-induced mouse model of colitis, a model simulating human ulcerative colitis. Results TRC160334 treatment resulted in significant improvement in disease end points in both models of colitis. TRC160334 treatment resulted into cytoprotective heatshock protein 70 induction in inflamed colon. TRC160334 successfully attenuated the rate of fall in body weight, disease activity index, and macroscopic and microscopic scores of colonic damage leading to overall improvement in study outcome. Conclusion Our findings are the first to demonstrate that therapeutic intervention with a HIF hydroxylase inhibitor ameliorates IBD in disease models. These findings highlight the potential of TRC160334 for its clinical application in the treatment of IBD. PMID:24493931

  15. Expression of Xanthophyllomyces dendrorhous cytochrome-P450 hydroxylase and reductase in Mucor circinelloides.

    Science.gov (United States)

    Csernetics, Árpád; Tóth, Eszter; Farkas, Anita; Nagy, Gábor; Bencsik, Ottó; Vágvölgyi, Csaba; Papp, Tamás

    2015-02-01

    Carotenoids are natural pigments that act as powerful antioxidants and have various beneficial effects on human and animal health. Mucor circinelloides (Mucoromycotina) is a carotenoid producing zygomycetes fungus, which accumulates β-carotene as the main carotenoid but also able to produce the hydroxylated derivatives of β-carotene (i.e. zeaxanthin and β-cryptoxanthin) in low amount. These xanthophylls, together with the ketolated derivatives of β-carotene (such as canthaxanthin, echinenone and astaxanthin) have better antioxidant activity than β-carotene. In this study our aim was to modify and enhance the xanthophyll production of the M. circinelloides by expression of heterologous genes responsible for the astaxanthin biosynthesis. The crtS and crtR genes, encoding the cytochrome-P450 hydroxylase and reductase, respectively, of wild-type and astaxanthin overproducing mutant Xanthophyllomyces dendrorhous strains were amplified from cDNA and the nucleotide and the deduced amino acid sequences were compared to each other. Introduction of the crtS on autonomously replicating plasmid in the wild-type M. circinelloides resulted enhanced zeaxanthin and β-cryptoxanthin accumulation and the presence of canthaxanthin, echinenone and astaxanthin in low amount; the β-carotene hydroxylase and ketolase activity of the X. dendrorhous cytochrome-P450 hydroxylase in M. circinelloides was verified. Increased canthaxanthin and echinenone production was observed by expression of the gene in a canthaxanthin producing mutant M. circinelloides. Co-expression of the crtR and crtS genes led to increase in the total carotenoid and slight change in xanthophyll accumulation in comparison with transformants harbouring the single crtS gene.

  16. Live Borrelia burgdorferi preferentially activate interleukin-1 beta gene expression and protein synthesis over the interleukin-1 receptor antagonist.

    Science.gov (United States)

    Miller, L C; Isa, S; Vannier, E; Georgilis, K; Steere, A C; Dinarello, C A

    1992-01-01

    Lyme arthritis is one of the few forms of chronic arthritis in which the cause is known with certainty. Because cytokines are thought to contribute to the pathogenesis of chronic arthritis, we investigated the effect of the Lyme disease spirochete, Borrelia burgdorferi, on the gene expression and synthesis of IL-1 beta and the IL-1 receptor antagonist (IL-1ra) in human peripheral blood mononuclear cells. Live B. burgdorferi induced fivefold more IL-1 beta than IL-1 alpha and sevenfold more IL-1 beta than IL-1ra; LPS or sonicated B. burgdorferi induced similar amounts of all three cytokines. This preferential induction of IL-1 beta was most dramatic in response to a low passage, virulent preparation of B. burgdorferi vs. three high passage avirulent strains. No difference in induction of IL-1ra was seen between these strains. The marked induction of IL-1 beta was partially diminished by heat-treatment and abrogated by sonication; IL-1ra was not affected. This suggested that a membrane component(s) accounted for the preferential induction of IL-1 beta. However, recombinant outer surface protein beta induced little IL-1 beta. By 4 h after stimulation, B. burgdorferi induced sixfold more IL-1 beta protein than LPS. In contrast to LPS-induced IL-1 beta mRNA which reached maximal accumulation after 3 h, B. burgdorferi-induced IL-1 beta mRNA showed biphasic elevations at 3 and 18 h. B. burgdorferi-induced IL-1ra mRNA peaked at 12 h, whereas LPS-induced IL-1ra mRNA peaked at 9 h. IL-1 beta synthesis increased in response to increasing numbers of spirochetes, whereas IL-1ra synthesis did not. The preferential induction by B. burgdorferi of IL-1 beta over IL-1ra is an example of excess agonist over antagonist synthesis induced by a microbial pathogen, and may contribute to the destructive lesion of Lyme arthritis. Images PMID:1387885

  17. Functional implication of β-carotene hydroxylases in soybean nodulation.

    Science.gov (United States)

    Kim, Yun-Kyoung; Kim, Sunghan; Um, Ji-Hyun; Kim, Kyunga; Choi, Sun-Kang; Um, Byung-Hun; Kang, Suk-Woo; Kim, Jee-Woong; Takaichi, Shinichi; Song, Seok-Bo; Lee, Choon-Hwan; Kim, Ho-Seung; Kim, Ki Woo; Nam, Kyoung Hee; Lee, Suk-Ha; Kim, Yul-Ho; Park, Hyang-Mi; Ha, Sun-Hwa; Verma, Desh Pal S; Cheon, Choong-Ill

    2013-07-01

    Legume-Rhizobium spp. symbiosis requires signaling between the symbiotic partners and differential expression of plant genes during nodule development. Previously, we cloned a gene encoding a putative β-carotene hydroxylase (GmBCH1) from soybean (Glycine max) whose expression increased during nodulation with Bradyrhizobium japonicum. In this work, we extended our study to three GmBCHs to examine their possible role(s) in nodule development, as they were additionally identified as nodule specific, along with the completion of the soybean genome. In situ hybridization revealed the expression of three GmBCHs (GmBCH1, GmBCH2, and GmBCH3) in the infected cells of root nodules, and their enzymatic activities were confirmed by functional assays in Escherichia coli. Localization of GmBCHs by transfecting Arabidopsis (Arabidopsis thaliana) protoplasts with green fluorescent protein fusions and by electron microscopic immunogold detection in soybean nodules indicated that GmBCH2 and GmBCH3 were present in plastids, while GmBCH1 appeared to be cytosolic. RNA interference of the GmBCHs severely impaired nitrogen fixation as well as nodule development. Surprisingly, we failed to detect zeaxanthin, a product of GmBCH, or any other carotenoids in nodules. Therefore, we examined the possibility that most of the carotenoids in nodules are converted or cleaved to other compounds. We detected the expression of some carotenoid cleavage dioxygenases (GmCCDs) in wild-type nodules and also a reduced amount of zeaxanthin in GmCCD8-expressing E. coli, suggesting cleavage of the carotenoid. In view of these findings, we propose that carotenoids such as zeaxanthin synthesized in root nodules are cleaved by GmCCDs, and we discuss the possible roles of the carotenoid cleavage products in nodulation.

  18. Glycogen synthase kinase3 beta phosphorylates serine 33 of p53 and activates p53's transcriptional activity

    Directory of Open Access Journals (Sweden)

    Price Brendan D

    2001-07-01

    Full Text Available Abstract Background The p53 protein is activated by genotoxic stress, oncogene expression and during senescence, p53 transcriptionally activates genes involved in growth arrest and apoptosis. p53 activation is regulated by post-translational modification, including phosphorylation of the N-terminal transactivation domain. Here, we have examined how Glycogen Synthase Kinase (GSK3, a protein kinase involved in tumorigenesis, differentiation and apoptosis, phosphorylates and regulates p53. Results The 2 isoforms of GSK3, GSK3α and GSK3β, phosphorylate the sequence Ser-X-X-X-Ser(P when the C-terminal serine residue is already phosphorylated. Several p53 kinases were examined for their ability to create GSK3 phosphorylation sites on the p53 protein. Our results demonstrate that phosphorylation of serine 37 of p53 by DNA-PK creates a site for GSK3β phosphorylation at serine 33 in vitro. GSK3α did not phosphorylate p53 under any condition. GSK3β increased the transcriptional activity of the p53 protein in vivo. Mutation of either serine 33 or serine 37 of p53 to alanine blocked the ability of GSK3β to regulate p53 transcriptional activity. GSK3β is therefore able to regulate p53 function in vivo. p53's transcriptional activity is commonly increased by DNA damage. However, GSK3β kinase activity was inhibited in response to DNA damage, suggesting that GSK3β regulation of p53 is not involved in the p53-DNA damage response. Conclusions GSK3β can regulate p53's transcriptional activity by phosphorylating serine 33. However, GSK3β does not appear to be part of the p53-DNA damage response pathway. Instead, GSK3β may provide the link between p53 and non-DNA damage mechanisms for p53 activation.

  19. The inhibition of the human cholesterol 7α-hydroxylase gene (CYP7A1) promoter by fibrates in cultured cells is mediated via the liver x receptor α and peroxisome proliferator-activated receptor α heterodimer

    OpenAIRE

    Gbaguidi, G. Franck; Agellon, Luis B.

    2004-01-01

    In previous work, we showed that the binding of the liver x receptor α:peroxisome proliferator-activated receptor α (LXRα:PPARα) heterodimer to the murine Cyp7a1 gene promoter antagonizes the stimulatory effect of their respective ligands. In this study, we determined if LXRα:PPARα can also regulate human CYP7A1 gene promoter activity. Co-expression of LXRα and PPARα in McArdle RH7777 hepatoma cells decreased the activity of the human CYP7A1 gene promoter in response to fibrates and 25-hydrox...

  20. Beta-defensin-2 protein is a serum biomarker for disease activity in psoriasis and reaches biologically relevant concentrations in lesional skin.

    Directory of Open Access Journals (Sweden)

    Patrick A M Jansen

    Full Text Available BACKGROUND: Previous studies have extensively documented antimicrobial and chemotactic activities of beta-defensins. Human beta-defensin-2 (hBD-2 is strongly expressed in lesional psoriatic epidermis, and recently we have shown that high beta-defensin genomic copy number is associated with psoriasis susceptibility. It is not known, however, if biologically and pathophysiologically relevant concentrations of hBD-2 protein are present in vivo, which could support an antimicrobial and proinflammatory role of beta-defensins in lesional psoriatic epidermis. METHODOLOGY/PRINCIPAL FINDINGS: We found that systemic levels of hBD-2 showed a weak but significant correlation with beta defensin copy number in healthy controls but not in psoriasis patients with active disease. In psoriasis patients but not in atopic dermatitis patients, we found high systemic hBD-2 levels that strongly correlated with disease activity as assessed by the PASI score. Our findings suggest that systemic levels in psoriasis are largely determined by secretion from involved skin and not by genomic copy number. Modelling of the in vivo epidermal hBD-2 concentration based on the secretion rate in a reconstructed skin model for psoriatic epidermis provides evidence that epidermal hBD-2 levels in vivo are probably well above the concentrations required for in vitro antimicrobial and chemokine-like effects. CONCLUSIONS/SIGNIFICANCE: Serum hBD-2 appears to be a useful surrogate marker for disease activity in psoriasis. The discrepancy between hBD-2 levels in psoriasis and atopic dermatitis could explain the well known differences in infection rate between these two diseases.

  1. Structure of GES-1 at Atomic Resolution: Insights Into the Evolution of Carbapenamase Activity in the Class a Extended-Spectrum Beta-Lactamases

    Energy Technology Data Exchange (ETDEWEB)

    Smith, C.A.; /SLAC, SSRL; Caccamo, M.; /Notre Dame U.; Kantardjieff, K.A.; /Cal State, Fullerton; Vakulenko, S.; /Notre Dame U.

    2007-10-08

    The structure of the class A extended-spectrum {beta}-lactamase GES-1 from Klebsiella pneumoniae has been determined to 1.1 Angstrom resolution. GES-1 has the characteristic active-site disulfide bond of the carbapenemase family of {beta}-lactamases and has a structure that is very similar to those of other known carbapenemases, including NMC-A, SME-1 and KPC-2. Most residues implicated in the catalytic mechanism of this class of enzyme are present in the GES-1 active site, including Ser70, which forms a covalent bond with the carbonyl C atom of the {beta}-lactam ring of the substrate during the formation of an acyl-enzyme intermediate, Glu166, which is implicated as both the acylation and deacylation base, and Lys73, which is also implicated as the acylation base. A water molecule crucial to catalysis is observed in an identical location as in other class A {beta}-lactamases, interacting with the side chains of Ser70 and Glu166. One important residue, Asn170, also normally a ligand for the hydrolytic water, is missing from the GES-1 active site. This residue is a glycine in GES-1 and the enzyme is unable to hydrolyze imipenem. This points to this residue as being critically important in the hydrolysis of this class of {beta}-lactam substrate. This is further supported by flexible-docking studies of imipenem with in silico-generated Gly170Asn and Gly170Ser mutant GES-1 enzymes designed to mimic the active sites of imipenem-hydrolyzing point mutants GES-2 and GES-5.

  2. Simulation of TGF-Beta Activation by Low-Dose HZE Radiation in a Cell Culture

    Science.gov (United States)

    Plante, Ianik; Cucinotta, Francis A.

    2009-01-01

    High charge (Z) and energy (E) (HZE) nuclei comprised in the galactic cosmic rays are main contributors to space radiation risk. They induce many lesions in living matter such as non-specific oxidative damage and the double-strand breaks (DSBs), which are considered key precursors of early and late effects of radiation. There is increasing evidence that cells respond collectively rather than individually to radiation, suggesting the importance of cell signaling1. The transforming growth factor (TGF ) is a signaling peptide that is expressed in nearly all cell type and regulates a large array of cellular processes2. TGF have been shown to mediate cellular response to DNA damage3 and to induce apoptosis in non-irradiated cells cocultured with irradiated cells4. TFG molecules are secreted by cells in an inactive complex known as the latency-associated peptide (LAP). TGF is released from the LAP by a conformational change triggered by proteases, thrombospondin-1, integrins, acidic conditions and .OH radical5. TGF then binds to cells receptors and activates a cascade of events mediated by Smad proteins6, which might interfere with the repair of DNA. Meanwhile, increasingly sophisticated Brownian Dynamics (BD) algorithms have appeared recently in the literature7 and can be applied to study the interaction of molecules with receptors. These BD computer models have contributed to the elucidation of signal transduction, ligand accumulation and autocrine loops in the epidermal growth factor (EGF) and its receptor (EFGR) system8. To investigate the possible roles of TGF in an irradiated cell culture, our Monte-Carlo simulation codes of the radiation track structure9 will be used to calculate the activation of TFG triggered by .OH produced by low doses of HZE ions. The TGF molecules will then be followed by a BD algorithm in a medium representative of a cell culture to estimate the number of activated receptors.

  3. Broad Spectrum Chemotherapy: A Novel Approach Using Beta-Galactosidase Activated Pro-Drugs

    Science.gov (United States)

    2007-03-01

    significantly faster than WT. We tried to synthesize a conjugate of 5FU with galactose, although parts of the synthesis were successful, inseparable...100ug 1000ug Re la tiv e vi ab le c el l ( % o f c on tro l) 5-Fu-G / PC3-WT 5-FU/ PC3-WT 5-FU-G/PC3-lacZ 5-FU/PC3-lacZ 13 5FU has a notoriously...narrow window of efficacy. High concentrations cause systemic toxicity. We tested whether lacZ/β-gal could be used to activate and release 5FU in

  4. Renal sodium retention in cirrhotic rats depends on glucocorticoid-mediated activation of mineralocorticoid receptor due to decreased renal 11beta-HSD-2 activity

    DEFF Research Database (Denmark)

    Thiesson, Helle; Jensen, Boye L; Bistrup, Claus;

    2007-01-01

    rats with decompensated liver cirrhosis and ascites 7 wk after bile duct ligation (BDL). Renal 11beta-HSD-2 mRNA, protein, and activity were significantly decreased in decompensated rats. The urinary Na(+)/K(+) ratio was reduced by 40%. Renal epithelial sodium channel (ENaC) mRNA and immunostaining......, and reduced ascites formation to the same degree as direct inhibition of MR with K-canrenoate. Total potassium balance was negative in the BDL rats, whereas renal potassium excretion was unchanged. In the distal colon, expression of ENaC was increased in BDL rats. Fecal potassium excretion was increased...... by endogenous glucocorticoids. In addition, the overall potassium loss in the BDL model is due to increased fecal potassium excretion, which is associated with upregulation of ENaC in distal colon....

  5. In-beam PET measurement of $^{7}Li^{3+}$ irradiation induced $\\beta^+}$-activity

    CERN Document Server

    Priegnitz, M; Parodi, K; Sommerer, F; Fiedler, F; Enghardt, W

    2008-01-01

    At present positron emission tomography (PET) is the only feasible method of an in situ and non-invasive monitoring of patient irradiation with ions. At the experimental carbon ion treatment facility of the Gesellschaft für Schwerionenforschung (GSI) Darmstadt an in-beam PET scanner has been integrated into the treatment site and lead to a considerable quality improvement of the therapy. Since ions other than carbon are expected to come into operation in future patient treatment facilities, it is highly desirable to extend in-beam PET also to other therapeutic relevant ions, e.g. 7Li. Therefore, by means of the in-beam PET scanner at GSI the β+-activity induced by 7Li3+ ions has been investigated for the first time. Targets of PMMA, water, graphite and polyethylene were irradiated with monoenergetic, pencil-like beams of 7Li3+ with energies between 129.1 A MeV and 205.3 A MeV and intensities ranging from 3.0 × 107 to 1.9 × 108 ions s−1. This paper presents the measured β+-activity profiles as well as d...

  6. Garlic extract exhibits antiamyloidogenic activity on amyloid-beta fibrillogenesis: relevance to Alzheimer's disease.

    Science.gov (United States)

    Gupta, Veer Bala; Indi, S S; Rao, K S J

    2009-01-01

    Alzheimer's disease is characterized pathologically by the deposition of amyloid plaques. Fibrillar Abeta is the principal component of amyloid plaques in the brain of AD patients. The prevention of Abeta aggregation or dissolution of fibrillar Abeta has clinical significance. The present communication examined in vitro the antiamyloidogenic properties of garlic extract. The effects of aqueous garlic extract (both fresh and boiled) on Abeta aggregation and defibrillation were studied by thioflavin-T based fluorescence assay, transmission electron microscopy and SDS-polyacrylamide gel electrophoresis. The aqueous fresh garlic extract not only inhibited Abeta fibril formation in a concentration and time dependent manner but was also able to defibrillate Abeta preformed fibrils. The maximum defibrillization was observed after 2-3 days of incubation. The boiled aqueous garlic extract also retained its antiamyloidogenic activity. This indicated that antiamyloidogenic activity of garlic extract is non-enzymatic, i.e. proteases present in garlic did not degrade Abeta in solution. However, the fibril degrading ability of boiled garlic extract was significantly lost. The findings suggest that consumption of garlic may lead to inhibition of Abeta aggregation in human brain.

  7. Regulation of phenylalanine hydroxylase: conformational changes upon phenylalanine binding detected by hydrogen/deuterium exchange and mass spectrometry.

    Science.gov (United States)

    Li, Jun; Dangott, Lawrence J; Fitzpatrick, Paul F

    2010-04-20

    Phenylalanine acts as an allosteric activator of the tetrahydropterin-dependent enzyme phenylalanine hydroxylase. Hydrogen/deuterium exchange monitored by mass spectrometry has been used to gain insight into local conformational changes accompanying activation of rat phenylalanine hydroxylase by phenylalanine. Peptides in the regulatory and catalytic domains that lie in the interface between these two domains show large increases in the extent of deuterium incorporation from solvent in the presence of phenylalanine. In contrast, the effects of phenylalanine on the exchange kinetics of a mutant enzyme lacking the regulatory domain are limited to peptides surrounding the binding site for the amino acid substrate. These results support a model in which the N-terminus of the protein acts as an inhibitory peptide, with phenylalanine binding causing a conformational change in the regulatory domain that alters the interaction between the catalytic and regulatory domains.

  8. Activation of PPARd and RXRa stimulates fatty acid oxidatin and insulin secretion inpancreatic beta-cells

    DEFF Research Database (Denmark)

    Børgesen, Michael; Ravnskjær, Kim; Frigerio, Francesca;

    ACTIVATION OF PPARd AND RXRa STIMULATES FATTY ACID OXIDATION AND INSULIN SECRETION IN PANCREATIC b-CELLS Michael Boergesen1, Kim Ravnskjaer2, Francesca Frigerio3, Allan E. Karlsen4, Pierre Maechler3 and Susanne Mandrup1 1 Department of Biochemistry and Molecular Biology, University of Southern...... oxidation and dissipation of lipids particularly in skeletal muscle. Here we show that PPARd at the RNA as well as protein level is the most abundant PPAR subtype in the rat pancreatic ß-cell line INS-1E and in isolated rat pancreatic islets. In keeping with that, a large number of PPAR target genes...... involved in fatty acid uptake and oxidation. This correlates with a 5-fold induction of 14C-Oleate ß-oxidation when INS-1E cells are exposed to PPARd and RXR agonists. Notably, culture of INS-1E cells with oleate and other unsaturated fatty acids in the presence of an RXR agonist induces the same subset...

  9. α-Iso-cubebene exerts neuroprotective effects in amyloid beta stimulated microglia activation.

    Science.gov (United States)

    Park, Sun Young; Park, Se Jin; Park, Nan Jeong; Joo, Woo Hong; Lee, Sang-Joon; Choi, Young-Whan

    2013-10-25

    Schisandra chinensis is commonly used for food and as a traditional remedy for the treatment of neuronal disorders. However, it is unclear which component of S. chinensis is responsible for its neuropharmacological effects. To answer this question, we isolated α-iso-cubebene, a dibenzocyclooctadiene lignin, from S. chinensis and determined if it has any anti-neuroinflammatory and neuroprotective properties against amyloid β-induced neuroinflammation in microglia. Microglia that are stimulated by amyloid β increased their production of pro-inflammatory cytokines and chemokines, prostaglandin E2 (PGE2), nitric oxide (NO) and reactive oxygen species (ROS) and the enzymatic activity of matrix metalloproteinase 9 (MMP-9). We found this was all inhibited by α-iso-cubebene. Consistent with these results, α-iso-cubebene inhibited the expression of inducible nitric oxide synthase (iNOS), cyclooxygenase 2 (COX-2) and MMP-9 in amyloid β-stimulated microglia. Subsequent mechanistic studies revealed that α-iso-cubebene inhibited the phosphorylation and degradation of IκB-α, the phosphorylation and transactivity of NF-κB, and the phosphorylation of MAPK in amyloid β-stimulated microglia. These results suggest that α-iso-cubebene impairs the amyloid β-induced neuroinflammatory response of microglia by inhibiting the NF-κB and MAPK signaling pathways. Importantly, α-iso-cubebene can provide critical neuroprotection for primary cortical neurons against amyloid β-stimulated microglia-mediated neurotoxicity. To the best of our knowledge, this is the first report showing that α-iso