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Sample records for mice lacking cytochrome

  1. Cytochrome P450 humanised mice

    Directory of Open Access Journals (Sweden)

    Gonzalez Frank J

    2004-05-01

    Full Text Available Abstract Humans are exposed to countless foreign compounds, typically referred to as xenobiotics. These can include clinically used drugs, environmental pollutants, food additives, pesticides, herbicides and even natural plant compounds. Xenobiotics are metabolised primarily in the liver, but also in the gut and other organs, to derivatives that are more easily eliminated from the body. In some cases, however, a compound is converted to an electrophile that can cause cell toxicity and transformation leading to cancer. Among the most important xenobiotic-metabolising enzymes are the cytochromes P450 (P450s. These enzymes represent a superfamily of multiple forms that exhibit marked species differences in their expression and catalytic activities. To predict how humans will metabolise xenobiotics, including drugs, human liver extracts and recombinant P450s have been used. New humanised mouse models are being developed which will be of great value in the study of drug metabolism, pharmacokinetics and pharmacodynamics in vivo, and in carrying out human risk assessment of xenobiotics. Humanised mice expressing CYP2D6 and CYP3A4, two major drug-metabolising P450s, have revealed the feasibility of this approach.

  2. Cytochrome P450 humanised mice

    Science.gov (United States)

    2004-01-01

    Humans are exposed to countless foreign compounds, typically referred to as xenobiotics. These can include clinically used drugs, environmental pollutants, food additives, pesticides, herbicides and even natural plant compounds. Xenobiotics are metabolised primarily in the liver, but also in the gut and other organs, to derivatives that are more easily eliminated from the body. In some cases, however, a compound is converted to an electrophile that can cause cell toxicity and transformation leading to cancer. Among the most important xenobiotic-metabolising enzymes are the cytochromes P450 (P450s). These enzymes represent a superfamily of multiple forms that exhibit marked species differences in their expression and catalytic activities. To predict how humans will metabolise xenobiotics, including drugs, human liver extracts and recombinant P450s have been used. New humanised mouse models are being developed which will be of great value in the study of drug metabolism, pharmacokinetics and pharmacodynamics in vivo, and in carrying out human risk assessment of xenobiotics. Humanised mice expressing CYP2D6 and CYP3A4, two major drug-metabolising P450s, have revealed the feasibility of this approach. PMID:15588489

  3. Reduced alcohol consumption in mice lacking preprodynorphin.

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    Blednov, Yuri A; Walker, Danielle; Martinez, Marni; Harris, R Adron

    2006-10-01

    Many studies suggest a role for endogenous opioid peptides and their receptors in regulation of ethanol intake. It is commonly accepted that the kappa-opioid receptors and their endogenous ligands, dynorphins, produce a dysphoric state and therefore may be responsible for avoidance of alcohol. We used mutant mice lacking preprodynorphin in a variety of behavioral tests of alcohol actions. Null mutant female, but not male, mice showed significantly lower preference for alcohol and consumed lower amounts of alcohol in a two-bottle choice test as compared with wild-type littermates. In the same test, knockout mice of both sexes showed a strong reduction of preference for saccharin compared to control mice. In contrast, under conditions of limited (4 h) access (light phase of the light/dark cycle), null mutant mice did not show any differences in consumption of saccharin, but they showed significantly reduced intake of sucrose. To determine the possible cause for reduction of ethanol preference and intake, we studied other ethanol-related behaviors in mice lacking the preprodynorphin gene. There were no differences between null mutant and wild-type mice in ethanol-induced loss of righting reflex, acute ethanol withdrawal, ethanol-induced conditioned place preference, or conditioned taste aversion to ethanol. These results indicate that deletion of preprodynorphin leads to substantial reduction of alcohol intake in female mice, and suggest that this is caused by decreased orosensory reward of alcohol (sweet taste and/or palatability).

  4. Mice lacking major brain gangliosides develop parkinsonism.

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    Wu, Gusheng; Lu, Zi-Hua; Kulkarni, Neil; Amin, Ruchi; Ledeen, Robert W

    2011-09-01

    Parkinson's disease (PD) is the second most prevalent late-onset neurodegenerative disorder that affects nearly 1% of the global population aged 65 and older. Whereas palliative treatments are in use, the goal of blocking progression of motor and cognitive disability remains unfulfilled. A better understanding of the basic pathophysiological mechanisms underlying PD would help to advance that goal. The present study provides evidence that brain ganglioside abnormality, in particular GM1, may be involved. This is based on use of the genetically altered mice with disrupted gene Galgt1 for GM2/GD2 synthase which depletes GM2/GD2 and all the gangliotetraose gangliosides that constitute the major molecular species of brain. These knockout mice show overt motor disability on aging and clear indications of motor impairment with appropriate testing at an earlier age. This disability was rectified by L-dopa administration. These mice show other characteristic symptoms of PD, including depletion of striatal dopamine (DA), loss of DA neurons of the substantia nigra pars compacta, and aggregation of alpha synuclein. These manifestations of parkinsonism were largely attenuated by administration of LIGA-20, a membrane permeable analog of GM1 that penetrates the blood brain barrier and enters living neurons. These results suggest that perturbation of intracellular mechanisms mediated by intracellular GM1 may be a contributing factor to PD.

  5. Lack of evidence for metabolism of p-phenylenediamine by human hepatic cytochrome P450 enzymes

    International Nuclear Information System (INIS)

    Stanley, Lesley A.; Skare, Julie A.; Doyle, Edward; Powrie, Robert; D'Angelo, Diane; Elcombe, Clifford R.

    2005-01-01

    p-Phenylenediamine (PPD) is a widely used ingredient in permanent hair dyes; however, little has been published on its metabolism, especially with respect to hepatic cytochrome P450 (CYP)-mediated oxidation. This is regarded as a key step in the activation of carcinogenic arylamines that ultimately leads to the development of bladder cancer. Most epidemiology studies show no significant association between personal use of hair dyes and bladder cancer, but one recent study reported an increased risk of bladder cancer in women who were frequent users of permanent hair dyes. The aim of the present study was to use intact human hepatocytes, human liver microsomes, and heterologously expressed human CYPs to determine whether PPD is metabolised by hepatic CYPs to form an N-hydroxylamine. p-Phenylenediamine was N-acetylated by human hepatocytes to form N-acetylated metabolites, but there was no evidence for the formation of mono-oxygenated metabolites or for enzyme-mediated covalent binding of 14 C-PPD to microsomal protein. In contrast, 2-aminofluorene underwent CYP-mediated metabolism to ≥4 different hydroxylated metabolites. The lack of evidence for hepatic CYP-mediated metabolism of PPD is inconsistent with the hypothesis that this compound plays a causal role in the development of bladder cancer via a mode of action involving hepatic metabolism to an N-hydroxyarylamine

  6. Kidney failure in mice lacking the tetraspanin CD151

    NARCIS (Netherlands)

    Sachs, Norman; Kreft, Maaike; van den Bergh Weerman, Marius A.; Beynon, Andy J.; Peters, Theo A.; Weening, Jan J.; Sonnenberg, Arnoud

    2006-01-01

    The tetraspanin CD151 is a cell-surface molecule known for its strong lateral interaction with the laminin-binding integrin alpha3beta1. Patients with a nonsense mutation in CD151 display end-stage kidney failure associated with regional skin blistering and sensorineural deafness, and mice lacking

  7. Kidney failure in mice lacking the tetraspanin CD151.

    NARCIS (Netherlands)

    Sachs, N.; Kreft, M.; Bergh Weerman, M. van der; Beynon, A.J.; Peters, T.A.; Weening, J.J.; Sonnenberg, A.

    2006-01-01

    The tetraspanin CD151 is a cell-surface molecule known for its strong lateral interaction with the laminin-binding integrin alpha3beta1. Patients with a nonsense mutation in CD151 display end-stage kidney failure associated with regional skin blistering and sensorineural deafness, and mice lacking

  8. Motor hypertonia and lack of locomotor coordination in mutant mice lacking DSCAM.

    Science.gov (United States)

    Lemieux, Maxime; Laflamme, Olivier D; Thiry, Louise; Boulanger-Piette, Antoine; Frenette, Jérôme; Bretzner, Frédéric

    2016-03-01

    Down syndrome cell adherence molecule (DSCAM) contributes to the normal establishment and maintenance of neural circuits. Whereas there is abundant literature regarding the role of DSCAM in the neural patterning of the mammalian retina, less is known about motor circuits. Recently, DSCAM mutation has been shown to impair bilateral motor coordination during respiration, thus causing death at birth. DSCAM mutants that survive through adulthood display a lack of locomotor endurance and coordination in the rotarod test, thus suggesting that the DSCAM mutation impairs motor control. We investigated the motor and locomotor functions of DSCAM(2J) mutant mice through a combination of anatomical, kinematic, force, and electromyographic recordings. With respect to wild-type mice, DSCAM(2J) mice displayed a longer swing phase with a limb hyperflexion at the expense of a shorter stance phase during locomotion. Furthermore, electromyographic activity in the flexor and extensor muscles was increased and coactivated over 20% of the step cycle over a wide range of walking speeds. In contrast to wild-type mice, which used lateral walk and trot at walking speed, DSCAM(2J) mice used preferentially less coordinated gaits, such as out-of-phase walk and pace. The neuromuscular junction and the contractile properties of muscles, as well as their muscle spindles, were normal, and no signs of motor rigidity or spasticity were observed during passive limb movements. Our study demonstrates that the DSCAM mutation induces dystonic hypertonia and a disruption of locomotor gaits. Copyright © 2016 the American Physiological Society.

  9. Impaired intestinal proglucagon processing in mice lacking prohormone convertase 1

    DEFF Research Database (Denmark)

    Ugleholdt, Randi; Zhu, Xiaorong; Deacon, Carolyn F

    2003-01-01

    proglucagon processing showed marked defects. Tissue proglucagon levels in null mice were elevated, and proglucagon processing to glicentin, oxyntomodulin, and glucagon-like peptide-1 and -2 (GLP-1 and GLP-2) was markedly decreased, indicating that PC1 is essential for the processing of all the intestinal...... proglucagon cleavage sites. This includes the monobasic site R(77) and, thereby, production of mature, biologically active GLP-1. We also found elevated glucagon levels, suggesting that factors other than PC1 that are capable of processing to mature glucagon are present in the secretory granules of the L cell......The neuroendocrine prohormone convertases 1 and 2 (PC1 and PC2) are expressed in endocrine intestinal L cells and pancreatic A cells, respectively, and colocalize with proglucagon in secretory granules. Mice lacking PC2 have multiple endocrinopathies and cannot process proglucagon to mature...

  10. Multiple sleep alterations in mice lacking cannabinoid type 1 receptors.

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    Alessandro Silvani

    Full Text Available Cannabinoid type 1 (CB1 receptors are highly expressed in the brain and play a role in behavior control. Endogenous cannabinoid signaling is modulated by high-fat diet (HFD. We investigated the consequences of congenital lack of CB1 receptors on sleep in mice fed standard diet (SD and HFD. CB1 cannabinoid receptor knock-out (KO and wild-type (WT mice were fed SD or HFD for 4 months (n = 9-10 per group. Mice were instrumented with electroencephalographic (EEG and electromyographic electrodes. Recordings were performed during baseline (48 hours, sleep deprivation (gentle handling, 6 hours, sleep recovery (18 hours, and after cage switch (insomnia model paradigm, 6 hours. We found multiple significant effects of genotype on sleep. In particular, KO spent more time awake and less time in non-rapid-eye-movement sleep (NREMS and rapid-eye-movement sleep (REMS than WT during the dark (active period but not during the light (rest period, enhancing the day-night variation of wake-sleep amounts. KO had slower EEG theta rhythm during REMS. REMS homeostasis after sleep deprivation was less effective in KO than in WT. Finally, KO habituated more rapidly to the arousing effect of the cage-switch test than WT. We did not find any significant effects of diet or of diet x genotype interaction on sleep. The occurrence of multiple sleep alterations in KO indicates important roles of CB1 cannabinoid receptors in limiting arousal during the active period of the day, in sleep regulation, and in sleep EEG in mice.

  11. Lethal Cardiomyopathy in Mice Lacking Transferrin Receptor in the Heart

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    Wenjing Xu

    2015-10-01

    Full Text Available Both iron overload and iron deficiency have been associated with cardiomyopathy and heart failure, but cardiac iron utilization is incompletely understood. We hypothesized that the transferrin receptor (Tfr1 might play a role in cardiac iron uptake and used gene targeting to examine the role of Tfr1 in vivo. Surprisingly, we found that decreased iron, due to inactivation of Tfr1, was associated with severe cardiac consequences. Mice lacking Tfr1 in the heart died in the second week of life and had cardiomegaly, poor cardiac function, failure of mitochondrial respiration, and ineffective mitophagy. The phenotype could only be rescued by aggressive iron therapy, but it was ameliorated by administration of nicotinamide riboside, an NAD precursor. Our findings underscore the importance of both Tfr1 and iron in the heart, and may inform therapy for patients with heart failure.

  12. Isolated cytochrome c oxidase deficiency in G93A SOD1 mice overexpressing CCS protein.

    Science.gov (United States)

    Son, Marjatta; Leary, Scot C; Romain, Nadine; Pierrel, Fabien; Winge, Dennis R; Haller, Ronald G; Elliott, Jeffrey L

    2008-05-02

    G93A SOD1 transgenic mice overexpressing CCS protein develop an accelerated disease course that is associated with enhanced mitochondrial pathology and increased mitochondrial localization of mutant SOD1. Because these results suggest an effect of mutant SOD1 on mitochondrial function, we assessed the enzymatic activities of mitochondrial respiratory chain complexes in the spinal cords of CCS/G93A SOD1 and control mice. CCS/G93A SOD1 mouse spinal cord demonstrates a 55% loss of complex IV (cytochrome c oxidase) activity compared with spinal cord from age-matched non-transgenic or G93A SOD1 mice. In contrast, CCS/G93A SOD1 spinal cord shows no reduction in the activities of complex I, II, or III. Blue native gel analysis further demonstrates a marked reduction in the levels of complex IV but not of complex I, II, III, or V in spinal cords of CCS/G93A SOD1 mice compared with non-transgenic, G93A SOD1, or CCS/WT SOD1 controls. With SDS-PAGE analysis, spinal cords from CCS/G93A SOD1 mice showed significant decreases in the levels of two structural subunits of cytochrome c oxidase, COX1 and COX5b, relative to controls. In contrast, CCS/G93A SOD1 mouse spinal cord showed no reduction in levels of selected subunits from complexes I, II, III, or V. Heme A analyses of spinal cord further support the existence of cytochrome c oxidase deficiency in CCS/G93A SOD1 mice. Collectively, these results establish that CCS/G93A SOD1 mice manifest an isolated complex IV deficiency which may underlie a substantial part of mutant SOD1-induced mitochondrial cytopathy.

  13. Impaired cutaneous wound healing in mice lacking tetranectin

    DEFF Research Database (Denmark)

    Iba, Kousuke; Hatakeyama, Naoko; Kojima, Takashi

    2009-01-01

    disruption of the tetranectin gene to elucidate the biological function of tetranectin. In this study, we showed that wound healing was markedly delayed in tetranectin-null mice compared with wild-type mice. A single full-thickness incision was made in the dorsal skin. By 14 days after the incision......, the wounds fully healed in all wild-type mice based on the macroscopic closure; in contrast, the progress of wound healing in the tetranectin null mice appeared to be impaired. In histological analysis, wounds of wild-type mice showed complete reepithelialization and healed by 14 days after the incision....... However, those of tetranectin-null mice never showed complete reepithelialization at 14 days. At 21 days after the injury, the wound healed and was covered with an epidermis. These results supported the fact that tetranectin may play a role in the wound healing process....

  14. Mice lacking neuropeptide Y show increased sensitivity to cocaine

    DEFF Research Database (Denmark)

    Sørensen, Gunnar; Woldbye, David Paul Drucker

    2012-01-01

    There is increasing data implicating neuropeptide Y (NPY) in the neurobiology of addiction. This study explored the possible role of NPY in cocaine-induced behavior using NPY knockout mice. The transgenic mice showed a hypersensitive response to cocaine in three animal models of cocaine addiction...

  15. Opposing regulation of cytochrome P450 expression by CAR and PXR in hypothyroid mice

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    Park, Young Joo [Department of Internal Medicine, Seoul National University College of Medicine (Korea, Republic of); Seoul National University Bundang Hospital, Seoul (Korea, Republic of); Lee, Eun Kyung [Department of Internal Medicine, Seoul National University College of Medicine (Korea, Republic of); Lee, Yoon Kwang [Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX 77030 (United States); Park, Do Joon; Jang, Hak Chul [Department of Internal Medicine, Seoul National University College of Medicine (Korea, Republic of); Moore, David D., E-mail: moore@bcm.edu [Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX 77030 (United States)

    2012-09-01

    Clinical hypothyroidism affects various metabolic processes including drug metabolism. CYP2B and CYP3A are important cytochrome P450 drug metabolizing enzymes that are regulated by the xenobiotic receptors constitutive androstane receptor (CAR, NR1I3) and pregnane X receptor (PXR, NR1I2). We evaluated the regulation of the hepatic expression of CYPs by CAR and PXR in the hypothyroid state induced by a low-iodine diet containing 0.15% propylthiouracil. Expression of Cyp3a11 was suppressed in hypothyroid C57BL/6 wild type (WT) mice and a further decrement was observed in hypothyroid CAR{sup −/−} mice, but not in hypothyroid PXR{sup −/−} mice. In contrast, expression of Cyp2b10 was induced in both WT and PXR{sup −/−} hypothyroid mice, and this induction was abolished in CAR{sup −/−} mice and in and CAR{sup −/−} PXR{sup −/−} double knockouts. CAR mRNA expression was increased by hypothyroidism, while PXR expression remained unchanged. Carbamazepine (CBZ) is a commonly used antiepileptic that is metabolized by CYP3A isoforms. After CBZ treatment of normal chow fed mice, serum CBZ levels were highest in CAR{sup −/−} mice and lowest in WT and PXR{sup −/−} mice. Hypothyroid WT or PXR{sup −/−} mice survived chronic CBZ treatment, but all hypothyroid CAR{sup −/−} and CAR{sup −/−} PXR{sup −/−} mice died, with CAR{sup −/−}PXR{sup −/−} mice surviving longer than CAR{sup −/−} mice (12.3 ± 3.3 days vs. 6.3 ± 2.1 days, p = 0.04). All these findings suggest that hypothyroid status affects xenobiotic metabolism, with opposing responses of CAR and PXR and their CYP targets that can cancel each other out, decreasing serious metabolic derangement in response to a xenobiotic challenge. -- Highlights: ► Hypothyroid status activates CAR in mice and induces Cyp2b10 expression. ► Hypothyroid status suppresses PXR activity in mice and represses Cyp3a11 expression. ► These responses balance each other out in normal mice.

  16. Opposing regulation of cytochrome P450 expression by CAR and PXR in hypothyroid mice

    International Nuclear Information System (INIS)

    Park, Young Joo; Lee, Eun Kyung; Lee, Yoon Kwang; Park, Do Joon; Jang, Hak Chul; Moore, David D.

    2012-01-01

    Clinical hypothyroidism affects various metabolic processes including drug metabolism. CYP2B and CYP3A are important cytochrome P450 drug metabolizing enzymes that are regulated by the xenobiotic receptors constitutive androstane receptor (CAR, NR1I3) and pregnane X receptor (PXR, NR1I2). We evaluated the regulation of the hepatic expression of CYPs by CAR and PXR in the hypothyroid state induced by a low-iodine diet containing 0.15% propylthiouracil. Expression of Cyp3a11 was suppressed in hypothyroid C57BL/6 wild type (WT) mice and a further decrement was observed in hypothyroid CAR −/− mice, but not in hypothyroid PXR −/− mice. In contrast, expression of Cyp2b10 was induced in both WT and PXR −/− hypothyroid mice, and this induction was abolished in CAR −/− mice and in and CAR −/− PXR −/− double knockouts. CAR mRNA expression was increased by hypothyroidism, while PXR expression remained unchanged. Carbamazepine (CBZ) is a commonly used antiepileptic that is metabolized by CYP3A isoforms. After CBZ treatment of normal chow fed mice, serum CBZ levels were highest in CAR −/− mice and lowest in WT and PXR −/− mice. Hypothyroid WT or PXR −/− mice survived chronic CBZ treatment, but all hypothyroid CAR −/− and CAR −/− PXR −/− mice died, with CAR −/− PXR −/− mice surviving longer than CAR −/− mice (12.3 ± 3.3 days vs. 6.3 ± 2.1 days, p = 0.04). All these findings suggest that hypothyroid status affects xenobiotic metabolism, with opposing responses of CAR and PXR and their CYP targets that can cancel each other out, decreasing serious metabolic derangement in response to a xenobiotic challenge. -- Highlights: ► Hypothyroid status activates CAR in mice and induces Cyp2b10 expression. ► Hypothyroid status suppresses PXR activity in mice and represses Cyp3a11 expression. ► These responses balance each other out in normal mice. ► Hypothyroidism sensitizes CAR null mice to toxic effects of carbamazepine.

  17. Abnormal Cardiac Autonomic Regulation in Mice Lacking ASIC3

    Directory of Open Access Journals (Sweden)

    Ching-Feng Cheng

    2014-01-01

    Full Text Available Integration of sympathetic and parasympathetic outflow is essential in maintaining normal cardiac autonomic function. Recent studies demonstrate that acid-sensing ion channel 3 (ASIC3 is a sensitive acid sensor for cardiac ischemia and prolonged mild acidification can open ASIC3 and evoke a sustained inward current that fires action potentials in cardiac sensory neurons. However, the physiological role of ASIC3 in cardiac autonomic regulation is not known. In this study, we elucidate the role of ASIC3 in cardiac autonomic function using Asic3−/− mice. Asic3−/− mice showed normal baseline heart rate and lower blood pressure as compared with their wild-type littermates. Heart rate variability analyses revealed imbalanced autonomic regulation, with decreased sympathetic function. Furthermore, Asic3−/− mice demonstrated a blunted response to isoproterenol-induced cardiac tachycardia and prolonged duration to recover to baseline heart rate. Moreover, quantitative RT-PCR analysis of gene expression in sensory ganglia and heart revealed that no gene compensation for muscarinic acetylcholines receptors and beta-adrenalin receptors were found in Asic3−/− mice. In summary, we unraveled an important role of ASIC3 in regulating cardiac autonomic function, whereby loss of ASIC3 alters the normal physiological response to ischemic stimuli, which reveals new implications for therapy in autonomic nervous system-related cardiovascular diseases.

  18. Generation of mice lacking DUF1220 protein domains

    DEFF Research Database (Denmark)

    Keeney, J G; O'Bleness, M S; Anderson, N

    2015-01-01

    associations, a function for these domains has not been described. As a first step in addressing this question, we have developed the first transgenic model of DUF1220 function by removing the single DUF1220 domain (the ancestral form) encoded in the mouse genome. In a hypothesis generating exercise...... function, and potentially suggests a role in developmental metabolism. Finally, the substantially reduced fecundity we observe associated with KO mice argues that the ancestral DUF1220 domain provides an important biological functionthat is critical to survivability and reproductive success....

  19. Soybean meal fermented by Aspergillus awamori increases the cytochrome P-450 content of the liver microsomes of mice.

    Science.gov (United States)

    Kishida, T; Ataki, H; Takebe, M; Ebihara, K

    2000-04-01

    The effect of soybean meal fermented by Aspergillus awamori on the acute lethality of acetaldehyde, pentobarbital sleeping time, and cytochrome P-450 content of the hepatic microsomes was studied in mice. Most of the daidzin and genistin in soybean meal (SBM) were converted into the respective aglycones, daidzein and genistein, by fermentation. In experiment 1, mice were fed isonitrogenic test diets with one of the following five protein sources for 28 d: casein, SBM, fermented and hot-air-dried SBM (FSBM-HD), fermented and freeze-dried SBM (FSBM-FD), or methanol-extracted FSBM-FD (FSMB-FD-R). The acute lethality of acetaldehyde in mice fed the FSBM-FD diet was significantly lower than that in mice fed the SBM, FSBM-HD, or FSBM-FD-R diet. In experiments 2 and 3, mice were fed isonitrogenic test diets with one of the following four protein sources for 28 d: casein, SBM, FSBM-FD, and FSBM-FD-R. The pentobarbital sleeping time was significantly shorter and the cytochrome P-450 content was significantly higher in the mice fed the FSBM-FD diet than the respective value in mice fed the other test diets. In experiment 4, mice were fed one of eight diets which contained different levels of aglycone obtained by varying the proportion of FSBM-FD and FSBM-FD-R, for 28 d. The cytochrome P-450 content in hepatic microsomes increased as the dietary level of isoflavonoid aglycones increased, but there was a saturation phenomenon. These results suggest that soy isoflavonoid aglycones are more potent inducers of cytochrome P-450 than isoflavonoid glycosides.

  20. Magnetite Compensates for the Lack of a Pilin-Associated c-Type Cytochrome in Extracellular Electron Exchange

    DEFF Research Database (Denmark)

    Liu, Fanghua; Rotaru, Amelia-Elena; Shrestha, Pravin

    2015-01-01

    investigation revealed that magnetite attached to the electrically conductive pili of Geobacter species in a manner reminiscent of the association of the multi-heme c-type cytochrome OmcS with the pili of Geobacter sulfurreducens. Magnetite conferred extracellular electron capabilities on an Omc...

  1. Pharmacokinetics and Differential Regulation of Cytochrome P450 Enzymes in Type 1 Allergic Mice.

    Science.gov (United States)

    Tanino, Tadatoshi; Komada, Akira; Ueda, Koji; Bando, Toru; Nojiri, Yukie; Ueda, Yukari; Sakurai, Eiichi

    2016-12-01

    Type 1 allergic diseases are characterized by elevated production of specific immunoglobulin E (IgE) for each antigen and have become a significant health problem worldwide. This study investigated the effect of IgE-mediated allergy on drug pharmacokinetics. To further understand differential suppression of hepatic cytochrome P450 (P450) activity, we examined the inhibitory effect of nitric oxide (NO), a marker of allergic conditions. Seven days after primary sensitization (PS7) or secondary sensitization (SS7), hepatic CYP1A2, CYP2C, CYP2E1, and CYP3A activities were decreased to 45%-75% of the corresponding control; however, CYP2D activity was not downregulated. PS7 and SS7 did not change the expression levels of five P450 proteins. Disappearance of CYP1A2 and CYP2D substrates from the plasma was not significantly different between allergic mice and control mice. In contrast, the area under the curve of a CYP1A2-mediated metabolite in PS7 and SS7 mice was reduced by 50% of control values. Total clearances of a CYP2E1 substrate in PS7 and SS7 mice were significantly decreased to 70% and 50% respectively, of the control without altering plasma protein binding. Hepatic amounts of CYP1A2 and CYP2E1 substrates were enhanced by allergic induction, being responsible for each downregulated activity. NO scavenger treatment completely improved the downregulated P450 activities. Therefore, our data suggest that the onset of IgE-mediated allergy alters the pharmacokinetics of major P450-metabolic capacity-limited drugs except for CYP2D drugs. NO is highly expected to participate in regulatory mechanisms of the four P450 isoforms. Copyright © 2016 by The American Society for Pharmacology and Experimental Therapeutics.

  2. Colonization by non-pathogenic bacteria alters mRNA expression of cytochromes P450 in originally germ-free mice.

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    Jourová, L; Anzenbacher, P; Lišková, B; Matušková, Z; Hermanová, P; Hudcovic, T; Kozáková, H; Hrnčířová, L; Anzenbacherová, E

    2017-11-01

    Gut microbiota provides a wide range of beneficial function for the host and has an immense effect on the host's health state. It has also been shown that gut microbiome is often involved in the biotransformation of xenobiotics; however, the molecular mechanisms of the interaction between the gut bacteria and the metabolism of drugs by the host are still unclear. To investigate the effect of microbial colonization on messenger RNA (mRNA) expression of liver cytochromes P450 (CYPs), the main drug-metabolizing enzymes, we used germ-free (GF) mice, lacking the intestinal flora and mice monocolonized by non-pathogenic bacteria Lactobacillus plantarum NIZO2877 or probiotic bacteria Escherichia coli Nissle 1917 compared to specific pathogen-free (SPF) mice. Our results show that the mRNA expression of Cyp1a2 and Cyp2e1 was significantly increased, while the expression of Cyp3a11 mRNA was decreased under GF conditions compared to the SPF mice. The both bacteria L. plantarum NIZO2877 and E. coli Nissle 1917 given to the GF mice decreased the level of Cyp1a2 mRNA and normalized it to the control level. On the other hand, the colonization by these bacteria had no effect on the expression of Cyp3a11 mRNA in the liver of the GF mice (which remained decreased). Surprisingly, monocolonization with chosen bacterial strains has shown a different effect on the expression of Cyp2e1 mRNA in GF mice. Increased level of Cyp2e1 expression observed in the GF mice was found also in mice colonized by L. plantarum NIZO2877 ; however, the colonization with probiotic E. coli Nissle 1917 caused a decrease in Cyp2e1 expression and partially restored the SPF mice conditions.

  3. Lacking Ketohexokinase-A Exacerbates Renal Injury in Streptozotocin-induced Diabetic Mice.

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    Doke, Tomohito; Ishimoto, Takuji; Hayasaki, Takahiro; Ikeda, Satsuki; Hasebe, Masako; Hirayama, Akiyoshi; Soga, Tomoyoshi; Kato, Noritoshi; Kosugi, Tomoki; Tsuboi, Naotake; Lanaspa, Miguel A; Johnson, Richard J; Kadomatsu, Kenji; Maruyama, Shoichi

    2018-03-28

    Ketohexokinase (KHK), a primary enzyme in fructose metabolism, has two isoforms, namely, KHK-A and KHK-C. Previously, we reported that renal injury was reduced in streptozotocin-induced diabetic mice which lacked both isoforms. Although both isoforms express in kidney, it has not been elucidated whether each isoform plays distinct roles in the development of diabetic kidney disease (DKD). The aim of the study is to elucidate the role of KHK-A for DKD progression. Diabetes was induced by five consecutive daily intraperitoneal injections of streptozotocin (50 mg/kg) in C57BL/6 J wild-type mice, mice lacking KHK-A alone (KHK-A KO), and mice lacking both KHK-A and KHK-C (KHK-A/C KO). At 35 weeks, renal injury, inflammation, hypoxia, and oxidative stress were examined. Metabolomic analysis including polyol pathway, fructose metabolism, glycolysis, TCA (tricarboxylic acid) cycle, and NAD (nicotinamide adenine dinucleotide) metabolism in kidney and urine was done. Diabetic KHK-A KO mice developed severe renal injury compared to diabetic wild-type mice, and this was associated with further increases of intrarenal fructose, dihydroxyacetone phosphate (DHAP), TCA cycle intermediates levels, and severe inflammation. In contrast, renal injury was prevented in diabetic KHK-A/C KO mice compared to both wild-type and KHK-A KO diabetic mice. Further, diabetic KHK-A KO mice contained decreased renal NAD + level with the increase of renal hypoxia-inducible factor 1-alpha expression despite having increased renal nicotinamide (NAM) level. These results suggest that KHK-C might play a deleterious role in DKD progression through endogenous fructose metabolism, and that KHK-A plays a unique protective role against the development of DKD. Copyright © 2018. Published by Elsevier Inc.

  4. Mutant Mice Lacking the p53 C-Terminal Domain Model Telomere Syndromes

    NARCIS (Netherlands)

    Simeonova, I.; Jaber, S.; Draskovic, I.; Bardot, B.; Fang, M.; Bouarich-Bourimi, R.; Lejour, V.; Charbonnier, L.; Soudais, C.; Bourdon, J.C.; Huerre, M.; Londono-Vallejo, A.; Toledo, F.

    2013-01-01

    Mutations in p53, although frequent in human cancers, have not been implicated in telomere-related syndromes. Here, we show that homozygous mutant mice expressing p53(Delta31), a p53 lacking the C-terminal domain, exhibit increased p53 activity and suffer from aplastic anemia and pulmonary fibrosis,

  5. Increased consumption of ethanol and sugar water in mice lacking the dopamine D2 long receptor.

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    Bulwa, Zachary B; Sharlin, Jordan A; Clark, Peter J; Bhattacharya, Tushar K; Kilby, Chessa N; Wang, Yanyan; Rhodes, Justin S

    2011-11-01

    Individual differences in dopamine D2 receptor (D2R) expression in the brain are thought to influence motivation and reinforcement for ethanol and other rewards. D2R exists in two isoforms, D2 long (D2LR) and D2 short (D2SR), produced by alternative splicing of the same gene. The relative contributions of D2LR versus D2SR to ethanol and sugar water drinking are not known. Genetic engineering was used to produce a line of knockout (KO) mice that lack D2LR and consequently have increased expression of D2SR. KO and wild-type (WT) mice of both sexes were tested for intake of 20% ethanol, 10% sugar water and plain tap water using established drinking-in-the-dark procedures. Mice were also tested for effects of the D2 antagonist eticlopride on intake of ethanol to determine whether KO responses were caused by lack of D2LR or overrepresentation of D2SR. Locomotor activity on running wheels and in cages without wheels was also measured for comparison. D2L KO mice drank significantly more ethanol than WT in both sexes. KO mice drank more sugar water than WT in females but not in males. Eticlopride dose dependently decreased ethanol intake in all groups except male KO. KO mice were less physically active than WT in cages with or without running wheels. Results suggest that overrepresentation of D2SR contributes to increased intake of ethanol in the KO mice. Decreasing wheel running and general levels of physical activity in the KO mice rules out the possibility that higher intake results from higher motor activity. Results extend the literature implicating altered expression of D2R in risk for addiction by delineating the contribution of individual D2R isoforms. These findings suggest that D2LR and D2SR play differential roles in consumption of alcohol and sugar rewards. Copyright © 2011 Elsevier Inc. All rights reserved.

  6. Mice lacking inositol 1,4,5-trisphosphate receptors exhibit dry eye.

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    Takaaki Inaba

    Full Text Available Tear secretion is important as it supplies water to the ocular surface and keeps eyes moist. Both the parasympathetic and sympathetic pathways contribute to tear secretion. Although intracellular Ca2+ elevation in the acinar cells of lacrimal glands is a crucial event for tear secretion in both the pathways, the Ca2+ channel, which is responsible for the Ca2+ elevation in the sympathetic pathway, has not been sufficiently analyzed. In this study, we examined tear secretion in mice lacking the inositol 1,4,5-trisphosphate receptor (IP3R types 2 and 3 (Itpr2-/-;Itpr3-/-double-knockout mice. We found that tear secretion in both the parasympathetic and sympathetic pathways was abolished in Itpr2-/-;Itpr3-/- mice. Intracellular Ca2+ elevation in lacrimal acinar cells after acetylcholine and epinephrine stimulation was abolished in Itpr2-/-;Itpr3-/- mice. Consequently, Itpr2-/-;Itpr3-/- mice exhibited keratoconjunctival alteration and corneal epithelial barrier disruption. Inflammatory cell infiltration into the lacrimal glands and elevation of serum autoantibodies, a representative marker for Sjögren's syndrome (SS in humans, were also detected in older Itpr2-/-;Itpr3-/- mice. These results suggested that IP3Rs are essential for tear secretion in both parasympathetic and sympathetic pathways and that Itpr2-/-;Itpr3-/- mice could be a new dry eye mouse model with symptoms that mimic those of SS.

  7. Lack of the Lysosomal Membrane Protein, GLMP, in Mice Results in Metabolic Dysregulation in Liver.

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    Xiang Yi Kong

    Full Text Available Ablation of glycosylated lysosomal membrane protein (GLMP, formerly known as NCU-G1 has been shown to cause chronic liver injury which progresses into liver fibrosis in mice. Both lysosomal dysfunction and chronic liver injury can cause metabolic dysregulation. Glmp gt/gt mice (formerly known as Ncu-g1gt/gt mice were studied between 3 weeks and 9 months of age. Body weight gain and feed efficiency of Glmp gt/gt mice were comparable to wild type siblings, only at the age of 9 months the Glmp gt/gt siblings had significantly reduced body weight. Reduced size of epididymal fat pads was accompanied by hepatosplenomegaly in Glmp gt/gt mice. Blood analysis revealed reduced levels of blood glucose, circulating triacylglycerol and non-esterified fatty acids in Glmp gt/gt mice. Increased flux of glucose, increased de novo lipogenesis and lipid accumulation were detected in Glmp gt/gt primary hepatocytes, as well as elevated triacylglycerol levels in Glmp gt/gt liver homogenates, compared to hepatocytes and liver from wild type mice. Gene expression analysis showed an increased expression of genes involved in fatty acid uptake and lipogenesis in Glmp gt/gt liver compared to wild type. Our findings are in agreement with the metabolic alterations observed in other mouse models lacking lysosomal proteins, and with alterations characteristic for advanced chronic liver injury.

  8. Protective effect of tea polyphenols against paracetamol-induced hepatotoxicity in mice is significantly correlated with cytochrome P450 suppression.

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    Chen, Xia; Sun, Chang-Kai; Han, Guo-Zhu; Peng, Jin-Yong; Li, Ying; Liu, Yan-Xia; Lv, Yuan-Yuan; Liu, Ke-Xin; Zhou, Qin; Sun, Hui-Jun

    2009-04-21

    To investigate the hepatoprotective activity of tea polyphenols (TP) and its relation with cytochrome P450 (CYP450) expression in mice. Hepatic CYP450 and CYPb(5) levels were measured by UV-spectrophotometry in mice 2 d after intraperitoneal TP (25, 50 and 100 mg/kg per day). Then the mice were intragastricly pre-treated with TP (100, 200 and 400 mg/kg per day) for six days before paracetamol (1000 mg/kg) was given. Their acute mortality was compared with that of control mice. The mice were pre-treated with TP (100, 200, and 400 mg/kg per day) for five days before paracetamol (500 mg/kg) was given. Hepatic CYP2E1 and CYP1A2 protein and mRNA expression levels were evaluated by Western blotting, immunohistochemical staining and transcriptase-polymerase chain reaction. The hepatic CYP450 and CYPb(5) levels in mice of TP-treated groups (100, 200 and 400 mg/kg per day) were decreased in a dose-dependent manner compared with those in the negative control mice. TP significantly attenuated the paracetamol-induced hepatic injury and dramatically reduced the mortality of paracetamol-treated mice. Furthermore, TP reduced CYP2E1 and CYP1A2 expression at both protein and mRNA levels in a dose-dependent manner. TP possess potential hepatoprotective properties and can suppress CYP450 expression.

  9. Suppression of cytochrome p450 reductase enhances long-term hematopoietic stem cell repopulation efficiency in mice.

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    Yan Zhang

    Full Text Available BACKGROUND: Bone marrow microenvironment (niche plays essential roles in the fate of hematopoietic stem cells (HSCs. Intracellular and extracellular redox metabolic microenvironment is one of the critical factors for the maintenance of the niche. Cytochrome P450 reductase (CPR is an obligate electron donor to all microsomal cytochrome P450 enzymes (P450 or CYP, and contributes to the redox metabolic process. However, its role in maintaining HSCs is unknown. OBJECTIVE: To examine the effects of low CPR expression on HSCs function using a mouse model of globally suppressed Cpr gene expression (Cpr Low, CL mice. METHODS: Hematopoietic cell subpopulations in bone marrow (BM and peripheral blood (PB from WT and CL mice were examined for their repopulation and differentiation ability upon BM competitive transplantation and enriched HSC (LKS(+ transplantation. Effects of low CPR expression on hematopoiesis were examined by transplanting normal BM cells into CL recipients. Reactive oxygen species (ROS, cell cycle, and apoptosis in CL mice were analyzed by flow cytometry for DCF-DA fluorescence intensity, Ki67 protein, and Annexin-V, respectively. RESULTS: The levels of ROS in BM cells, HPCs and HSCs were comparable between CL and WT mice. In comparison to WT mice, the number of LT-HSCs or ST-HSCs was lower in CL mice while CMPs, GMPs and MEPs in CL mice were higher than that in WT control. Competitive transplantation assay revealed enhanced repopulation capacity of HSCs with low CPR expression, but no difference in differentiation potential upon in vitro experiments. Furthermore, lymphoid differentiation of donor cells decreased while their myeloid differentiation increased under CL microenvironment although the overall level of donor hematopoietic repopulation was not significantly altered. CONCLUSIONS: Our studies demonstrate that suppressing CPR expression enhances the repopulation efficiency of HSCs and a low CPR expression microenvironment favors

  10. Myocardial mitochondrial and contractile function are preserved in mice lacking adiponectin.

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    Martin Braun

    Full Text Available Adiponectin deficiency leads to increased myocardial infarct size following ischemia reperfusion and to exaggerated cardiac hypertrophy following pressure overload, entities that are causally linked to mitochondrial dysfunction. In skeletal muscle, lack of adiponectin results in impaired mitochondrial function. Thus, it was our objective to investigate whether adiponectin deficiency impairs mitochondrial energetics in the heart. At 8 weeks of age, heart weight-to-body weight ratios were not different between adiponectin knockout (ADQ-/- mice and wildtypes (WT. In isolated working hearts, cardiac output, aortic developed pressure and cardiac power were preserved in ADQ-/- mice. Rates of fatty acid oxidation, glucose oxidation and glycolysis were unchanged between groups. While myocardial oxygen consumption was slightly reduced (-24% in ADQ-/- mice in isolated working hearts, rates of maximal ADP-stimulated mitochondrial oxygen consumption and ATP synthesis in saponin-permeabilized cardiac fibers were preserved in ADQ-/- mice with glutamate, pyruvate or palmitoyl-carnitine as a substrate. In addition, enzymatic activity of respiratory complexes I and II was unchanged between groups. Phosphorylation of AMP-activated protein kinase and SIRT1 activity were not decreased, expression and acetylation of PGC-1α were unchanged, and mitochondrial content of OXPHOS subunits was not decreased in ADQ-/- mice. Finally, increasing energy demands due to prolonged subcutaneous infusion of isoproterenol did not differentially affect cardiac contractility or mitochondrial function in ADQ-/- mice compared to WT. Thus, mitochondrial and contractile function are preserved in hearts of mice lacking adiponectin, suggesting that adiponectin may be expendable in the regulation of mitochondrial energetics and contractile function in the heart under non-pathological conditions.

  11. Remodeling of the Cervix and Parturition in Mice Lacking the Progesterone Receptor B Isoform1

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    Yellon, Steven M.; Oshiro, Bryan T.; Chhaya, Tejas Y.; Lechuga, Thomas J.; Dias, Rejane M.; Burns, Alexandra E.; Force, Lindsey; Apostolakis, Ede M.

    2011-01-01

    Withdrawal of progestational support for pregnancy is part of the final common pathways for parturition, but the role of nuclear progesterone receptor (PGR) isoforms in this process is not known. To determine if the PGR-B isoform participates in cervical remodeling at term, cervices were obtained from mice lacking PGR-B (PGR-BKO) and from wild-type (WT) controls before or after birth. PGR-BKO mice gave birth to viable pups at the same time as WT controls during the early morning of Day 19 postbreeding. Morphological analyses indicated that by the day before birth, cervices from PGR-BKO and WT mice had increased in size, with fewer cell nuclei/area as well as diminished collagen content and structure, as evidenced by optical density of picrosirius red-stained sections, compared to cervices from nonpregnant mice. Moreover, increased numbers of resident macrophages, but not neutrophils, were found in the prepartum cervix of PGR-BKO compared to nonpregnant mice, parallel to findings in WT mice. These results suggest that PGR-B does not contribute to the growth or degradation of the extracellular matrix or proinflammatory processes associated with recruitment of macrophages in the cervix leading up to birth. Rather, other receptors may contribute to the progesterone-dependent mechanism that promotes remodeling of the cervix during pregnancy and in the proinflammatory process associated with ripening before parturition. PMID:21613631

  12. Regulation of ENaC in mice lacking renal insulin receptors in the collecting duct

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    Pavlov, Tengis S.; Ilatovskaya, Daria V.; Levchenko, Vladislav; Li, Lijun; Ecelbarger, Carolyn M.; Staruschenko, Alexander

    2013-01-01

    The epithelial sodium channel (ENaC) is one of the central effectors involved in regulation of salt and water homeostasis in the kidney. To study mechanisms of ENaC regulation, we generated knockout mice lacking the insulin receptor (InsR KO) specifically in the collecting duct principal cells. Single-channel analysis in freshly isolated split-open tubules demonstrated that the InsR-KO mice have significantly lower ENaC activity compared to their wild-type (C57BL/6J) littermates when animals were fed either normal or sodium-deficient diets. Immunohistochemical and Western blot assays demonstrated no significant changes in expression of ENaC subunits in InsR-KO mice compared to wild-type littermates. Insulin treatment caused greater ENaC activity in split-open tubules isolated from wild-type mice but did not have this effect in the InsR-KO mice. Thus, these results suggest that insulin increases ENaC activity via its own receptor affecting the channel open probability. To further determine the mechanism of the action of insulin on ENaC, we used mouse mpkCCDc14 principal cells. Insulin significantly augmented amiloride-sensitive transepithelial flux in these cells. Pretreatment of the mpkCCDc14 cells with phosphatidylinositol 3-kinase (LY294002; 10 μM) or mTOR (PP242; 100 nM) inhibitors precluded this effect. This study provides new information about the importance of insulin receptors expressed in collecting duct principal cells for ENaC activity.—Pavlov, T. S., Ilatovskaya, D. V., Levchenko, V., Li, L., Ecelbarger, C. M., Staruschenko, A. Regulation of ENaC in mice lacking renal insulin receptors in the collecting duct. PMID:23558339

  13. Lack of Melanopsin Is Associated with Extreme Weight Loss in Mice upon Dietary Challenge.

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    Didem Göz Aytürk

    Full Text Available Metabolic disorders have been established as major risk factors for ocular complications and poor vision. However, little is known about the inverse possibility that ocular disease may cause metabolic dysfunction. To test this hypothesis, we assessed the metabolic consequences of a robust dietary challenge in several mouse models suffering from retinal mutations. To this end, mice null for melanopsin (Opn4-/-, the photopigment of intrinsically photosensitive retinal ganglion cells (ipRGCs, were subjected to five weeks of a ketogenic diet. These mice lost significantly more weight than wild-type controls or mice lacking rod and cone photoreceptors (Pde6brd1/rd1. Although ipRGCs are critical for proper circadian entrainment, and circadian misalignment has been implicated in metabolic pathology, we observed no differences in entrainment between Opn4-/- and control mice. Additionally, we observed no differences in any tested metabolic parameter between these mouse strains. Further studies are required to establish the mechanism giving rise to this dramatic phenotype observed in melanopsin-null mice. We conclude that the causality between ocular disease and metabolic disorders merits further investigation due to the popularity of diets that rely on the induction of a ketogenic state. Our study is a first step toward understanding retinal pathology as a potential cause of metabolic dysfunction.

  14. A high-fat diet induces bone loss in mice lacking the Alox5 gene.

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    Le, Phuong; Kawai, Masanobu; Bornstein, Sheila; DeMambro, Victoria E; Horowitz, Mark C; Rosen, Clifford J

    2012-01-01

    5-Lipoxygenase catalyzes leukotriene generation from arachidonic acid. The gene that encodes 5-lipoxygenase, Alox5, has been identified in genome-wide association and mouse Quantitative Trait Locus studies as a candidate gene for obesity and low bone mass. Thus, we tested the hypothesis that Alox5(-/-) mice would exhibit metabolic and skeletal changes when challenged by a high-fat diet (HFD). On a regular diet, Alox5(-/-) mice did not differ in total body weight, percent fat mass, or bone mineral density compared with wild-type (WT) controls (P < 0.05). However, when placed on a HFD, Alox5(-/-) gained more fat mass and lost greater areal bone mass vs. WT (P < 0.05). Microarchitectural analyses revealed that on a HFD, WT showed increases in cortical area (P < 0.01) and trabecular thickness (P < 0.01), whereas Alox5(-/-) showed no change in cortical parameters but a decrease in trabecular number (P < 0.05) and bone volume fraction compared with WT controls (P < 0.05). By histomorphometry, a HFD did not change bone formation rates of either strain but produced an increase in osteoclast number per bone perimeter in Alox5(-/-) mice (P < 0.03). In vitro, osteoclastogenesis of marrow stromal cells was enhanced in mutant but not WT mice fed a HFD. Gene expression for Rankl, Pparg, and Cox-2 was greater in the femur of Alox5(-/-) than WT mice on a HFD (P < 0.01), but these increases were suppressed in the Alox5(-/-) mice after 8 wk of treatment with celecoxib, a cyclooxygenase-2 inhibitor. In sum, there is a strong gene by environmental interaction for bone mass when mice lacking the Alox5 gene are fed a HFD.

  15. Ethanol-related behaviors in mice lacking the sigma-1 receptor.

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    Valenza, Marta; DiLeo, Alyssa; Steardo, Luca; Cottone, Pietro; Sabino, Valentina

    2016-01-15

    The Sigma-1 receptor (Sig-1R) is a chaperone protein that has been implicated in drug abuse and addiction. Multiple studies have characterized the role the Sig-1R plays in psychostimulant addiction; however, fewer studies have specifically investigated its role in alcohol addiction. We have previously shown that antagonism of the Sig-1R reduces excessive drinking and motivation to drink, whereas agonism induces binge-like drinking in rodents. The objectives of these studies were to investigate the impact of Sig-1R gene deletion in C57Bl/6J mice on ethanol drinking and other ethanol-related behaviors. We used an extensive panel of behavioral tests to examine ethanol actions in male, adult mice lacking Oprs1, the gene encoding the Sig-1R. To compare ethanol drinking behavior, Sig-1 knockout (KO) and wild type (WT) mice were subject to a two-bottle choice, continuous access paradigm with different concentrations of ethanol (3-20% v/v) vs. water. Consumption of sweet and bitter solutions was also assessed in Sig-1R KO and WT mice. Finally, motor stimulant sensitivity, taste aversion and ataxic effects of ethanol were assessed. Sig-1R KO mice displayed higher ethanol intake compared to WT mice; the two genotypes did not differ in their sweet or bitter taste perception. Sig-1R KO mice showed lower sensitivity to ethanol stimulant effects, but greater sensitivity to its taste aversive effects. Ethanol-induced sedation was instead unaltered in the mutants. Our results prove that the deletion of the Sig-1R increases ethanol consumption, likely by decreasing its rewarding effects, and therefore indicating that the Sig-1R is involved in modulation of the reinforcing effects of alcohol. Copyright © 2015 Elsevier B.V. All rights reserved.

  16. Increased anxiety and fear memory in adult mice lacking type 2 deiodinase.

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    Bárez-López, Soledad; Montero-Pedrazuela, Ana; Bosch-García, Daniel; Venero, César; Guadaño-Ferraz, Ana

    2017-10-01

    A euthyroid state in the brain is crucial for its adequate development and function. Impairments in thyroid hormones (THs; T3 or 3,5,3'-triiodothyronine and T4 or thyroxine) levels and availability in brain can lead to neurological alterations and to psychiatric disorders, particularly mood disorders. The thyroid gland synthetizes mainly T4, which is secreted to circulating blood, however, most actions of THs are mediated by T3, the transcriptionally active form. In the brain, intracellular concentrations of T3 are modulated by the activity of type 2 (D2) and type 3 (D3) deiodinases. In the present work, we evaluated learning and memory capabilities and anxiety-like behavior at adult stages in mice lacking D2 (D2KO) and we analyzed the impact of D2-deficiency on TH content and on the expression of T3-dependent genes in the amygdala and the hippocampus. We found that D2KO mice do not present impairments in spatial learning and memory, but they display emotional alterations with increased anxiety-like behavior as well as enhanced auditory-cued fear memory and spontaneous recovery of fear memory following extinction. D2KO mice also presented reduced T3 content in the hippocampus and decreased expression of the T3-dependent gene Dio3 in the amygdala suggesting a hypothyroid status in this structure. We propose that the emotional dysfunctions found in D2KO mice can arise from the reduced T3 content in their brain, which consequently leads to alterations in gene expression with functional consequences. We found a downregulation in the gene encoding for the calcium-binding protein calretinin (Calb2) in the amygdala of D2KO mice that could affect the GABAergic transmission. The current findings in D2KO mice can provide insight into emotional disorders present in humans with DIO2 polymorphisms. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. Entrainment and phase-shifting by centrifugation abolished in mice lacking functional vestibular input

    Science.gov (United States)

    Fuller, Charles; Ringgold, Kristyn

    The circadian pacemaker can be phase shifted and entrained by appropriately timed locomotor activity, however the mechanism(s) involved remain poorly understood. Recent work in our lab has suggested the involvement of the vestibular otolith organs in activity-induced changes within the circadian timing system (CTS). For example, we have shown that changes in circa-dian period and phase in response to locomotion (wheel running) require functional macular gravity receptors. We believe the neurovestibular system is responsible for the transduction of gravitoinertial input associated with the types of locomotor activity that are known to af-fect the pacemaker. This study investigated the hypothesis that daily, timed gravitoinertial stimuli, as applied by centrifugation. would induce entrainment of circadian rhythms in only those animals with functional afferent vestibular input. To test this hypothesis, , chemically labyrinthectomized (Labx) mice, mice lacking macular vestibular input (head tilt or hets) and wildtype (WT) littermates were implanted i.p. with biotelemetry and individually housed in a 4-meter diameter centrifuge in constant darkness (DD). After 2 weeks in DD, the mice were exposed daily to 2G via centrifugation from 1000-1200 for 9 weeks. Only WT mice showed entrainment to the daily 2G pulse. The 2G pulse was then re-set to occur at 1200-1400 for 4 weeks. Only WT mice demonstrated a phase shift in response to the re-setting of the 2G pulse and subsequent re-entrainment to the new centrifugation schedule. These results provide further evidence that gravitoinertial stimuli require a functional vestibular system to both en-train and phase shift the CTS. Entrainment among only WT mice supports the role of macular gravity receptive cells in modulation of the CTS while also providing a functional mechanism by which gravitoinertial stimuli, including locomotor activity, may affect the pacemaker.

  18. Mice lacking hippocampal left-right asymmetry show non-spatial learning deficits.

    Science.gov (United States)

    Shimbo, Akihiro; Kosaki, Yutaka; Ito, Isao; Watanabe, Shigeru

    2018-01-15

    Left-right asymmetry is known to exist at several anatomical levels in the brain and recent studies have provided further evidence to show that it also exists at a molecular level in the hippocampal CA3-CA1 circuit. The distribution of N-methyl-d-aspartate (NMDA) receptor NR2B subunits in the apical and basal synapses of CA1 pyramidal neurons is asymmetrical if the input arrives from the left or right CA3 pyramidal neurons. In the present study, we examined the role of hippocampal asymmetry in cognitive function using β2-microglobulin knock-out (β2m KO) mice, which lack hippocampal asymmetry. We tested β2m KO mice in a series of spatial and non-spatial learning tasks and compared the performances of β2m KO and C57BL6/J wild-type (WT) mice. The β2m KO mice appeared normal in both spatial reference memory and spatial working memory tasks but they took more time than WT mice in learning the two non-spatial learning tasks (i.e., a differential reinforcement of lower rates of behavior (DRL) task and a straight runway task). The β2m KO mice also showed less precision in their response timing in the DRL task and showed weaker spontaneous recovery during extinction in the straight runway task. These results indicate that hippocampal asymmetry is important for certain characteristics of non-spatial learning. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. Increased brain damage after ischaemic stroke in mice lacking the chemokine receptor CCR5

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    Sorce, S; Bonnefont, J; Julien, S; Marq-Lin, N; Rodriguez, I; Dubois-Dauphin, M; Krause, KH

    2010-01-01

    Background and purpose: The chemokine receptor CCR5 is well known for its function in immune cells; however, it is also expressed in the brain, where its specific role remains to be elucidated. Because genetic factors may influence the risk of developing cerebral ischaemia or affect its clinical outcome, we have analysed the role of CCR5 in experimental stroke. Experimental approach: Permanent cerebral ischaemia was performed by occlusion of the middle cerebral artery in wild-type and CCR5-deficient mice. Locomotor behaviour, infarct size and histochemical alterations were analysed at different time points after occlusion. Key results: The cerebral vasculature was comparable in wild-type and CCR5-deficient mice. However, the size of the infarct and the motor deficits after occlusion were markedly increased in CCR5-deficient mice as compared with wild type. No differences between wild-type and CCR5-deficient mice were elicited by occlusion with respect to the morphology and abundance of astrocytes and microglia. Seven days after occlusion the majority of CCR5-deficient mice displayed neutrophil invasion in the infarct region, which was not observed in wild type. As compared with wild type, the infarct regions of CCR5-deficient mice were characterized by increased neuronal death. Conclusions and implications: Lack of CCR5 increased the severity of brain injury following occlusion of the middle cerebral artery. This is of particular interest with respect to the relatively frequent occurrence of CCR5 deficiency in the human population (1–2% of the Caucasian population) and the advent of CCR5 inhibitors as novel drugs. PMID:20423342

  20. Nicotine anxiogenic and rewarding effects are decreased in mice lacking beta-endorphin.

    Science.gov (United States)

    Trigo, José M; Zimmer, Andreas; Maldonado, Rafael

    2009-06-01

    The endogenous opioid system plays an important role in the behavioral effects of nicotine. Thus, micro-opioid receptor and the endogenous opioids derived from proenkephalin are involved in the central effects of nicotine. However, the role played by the different endogenous opioid peptides in the acute and chronic effects of nicotine remains to be fully established. Mice lacking beta-endorphin were acutely injected with nicotine at different doses to evaluate locomotor, anxiogenic and antinociceptive responses. The rewarding properties of nicotine were evaluated by using the conditioned place-preference paradigm. Mice chronically treated with nicotine were acutely injected with mecamylamine to study the behavioral expression of nicotine withdrawal. Mice lacking beta-endorphin exhibited a spontaneous hypoalgesia and hyperlocomotion and a reduction on the anxiogenic and rewarding effects induced by nicotine. Nicotine induced similar antinociception and hypolocomotion in both genotypes and no differences were found in the development of physical dependence. The dissociation between nicotine rewarding properties and physical dependence suggests a differential implication of beta-endorphin in these addictive related responses.

  1. Nicotine anxiogenic and rewarding effects are decreased in mice lacking β-endorphin

    Science.gov (United States)

    Trigo, José M.; Zimmer, Andreas; Maldonado, Rafael

    2009-01-01

    The endogenous opioid system plays an important role in the behavioral effects of nicotine. Thus, μ-opioid receptor and the endogenous opioids derived from proenkephalin are involved in the central effects of nicotine. However, the role played by the different endogenous opioid peptides in the acute and chronic effects of nicotine remains to be fully established. Mice lacking β-endorphin were acutely injected with nicotine at different doses to evaluate locomotor, anxiogenic and antinociceptive responses. The rewarding properties of nicotine were evaluated by using the conditioned place-preference paradigm. Mice chronically treated with nicotine were acutely injected with mecamylamine to study the behavioral expression of nicotine withdrawal. Mice lacking β-endorphin exhibited a spontaneous hypoalgesia and hyperlocomotion and a reduction on the anxiogenic and rewarding effects induced by nicotine. Nicotine induced similar antinociception and hypolocomotion in both genotypes and no differences were found in the development of physical dependence. The dissociation between nicotine rewarding properties and physical dependence suggests a differential implication of β-endorphin in these addictive related responses. PMID:19376143

  2. Peroxisome Proliferator-Activated Receptor α Activation Suppresses Cytochrome P450 Induction Potential in Mice Treated with Gemfibrozil.

    Science.gov (United States)

    Shi, Cunzhong; Min, Luo; Yang, Julin; Dai, Manyun; Song, Danjun; Hua, Huiying; Xu, Gangming; Gonzalez, Frank J; Liu, Aiming

    2017-09-01

    Gemfibrozil, a peroxisome proliferator-activated receptor α (PPARα) agonist, is widely used for hypertriglyceridaemia and mixed hyperlipidaemia. Drug-drug interaction of gemfibrozil and other PPARα agonists has been reported. However, the role of PPARα in cytochrome P450 (CYP) induction by fibrates is not well known. In this study, wild-type mice were first fed gemfibrozil-containing diets (0.375%, 0.75% and 1.5%) for 14 days to establish a dose-response relationship for CYP induction. Then, wild-type mice and Pparα-null mice were treated with a 0.75% gemfibrozil-containing diet for 7 days. CYP3a, CYP2b and CYP2c were induced in a dose-dependent manner by gemfibrozil. In Pparα-null mice, their mRNA level, protein level and activity were induced more than those in wild-type mice. So, gemfibrozil induced CYP, and this action was inhibited by activated PPARα. These data suggested that the induction potential of CYPs was suppressed by activated PPARα, showing a potential role of this receptor in drug-drug interactions and metabolic diseases treated with fibrates. © 2017 Nordic Association for the Publication of BCPT (former Nordic Pharmacological Society).

  3. Impaired Glucose Metabolism in Mice Lacking the Tas1r3 Taste Receptor Gene.

    Science.gov (United States)

    Murovets, Vladimir O; Bachmanov, Alexander A; Zolotarev, Vasiliy A

    2015-01-01

    The G-protein-coupled sweet taste receptor dimer T1R2/T1R3 is expressed in taste bud cells in the oral cavity. In recent years, its involvement in membrane glucose sensing was discovered in endocrine cells regulating glucose homeostasis. We investigated importance of extraorally expressed T1R3 taste receptor protein in age-dependent control of blood glucose homeostasis in vivo, using nonfasted mice with a targeted mutation of the Tas1r3 gene that encodes the T1R3 protein. Glucose and insulin tolerance tests, as well as behavioral tests measuring taste responses to sucrose solutions, were performed with C57BL/6ByJ (Tas1r3+/+) inbred mice bearing the wild-type allele and C57BL/6J-Tas1r3tm1Rfm mice lacking the entire Tas1r3 coding region and devoid of the T1R3 protein (Tas1r3-/-). Compared with Tas1r3+/+ mice, Tas1r3-/- mice lacked attraction to sucrose in brief-access licking tests, had diminished taste preferences for sucrose solutions in the two-bottle tests, and had reduced insulin sensitivity and tolerance to glucose administered intraperitoneally or intragastrically, which suggests that these effects are due to absence of T1R3. Impairment of glucose clearance in Tas1r3-/- mice was exacerbated with age after intraperitoneal but not intragastric administration of glucose, pointing to a compensatory role of extraoral T1R3-dependent mechanisms in offsetting age-dependent decline in regulation of glucose homeostasis. Incretin effects were similar in Tas1r3+/+ and Tas1r3-/- mice, which suggests that control of blood glucose clearance is associated with effects of extraoral T1R3 in tissues other than the gastrointestinal tract. Collectively, the obtained data demonstrate that the T1R3 receptor protein plays an important role in control of glucose homeostasis not only by regulating sugar intake but also via its extraoral function, probably in the pancreas and brain.

  4. Impaired Glucose Metabolism in Mice Lacking the Tas1r3 Taste Receptor Gene.

    Directory of Open Access Journals (Sweden)

    Vladimir O Murovets

    Full Text Available The G-protein-coupled sweet taste receptor dimer T1R2/T1R3 is expressed in taste bud cells in the oral cavity. In recent years, its involvement in membrane glucose sensing was discovered in endocrine cells regulating glucose homeostasis. We investigated importance of extraorally expressed T1R3 taste receptor protein in age-dependent control of blood glucose homeostasis in vivo, using nonfasted mice with a targeted mutation of the Tas1r3 gene that encodes the T1R3 protein. Glucose and insulin tolerance tests, as well as behavioral tests measuring taste responses to sucrose solutions, were performed with C57BL/6ByJ (Tas1r3+/+ inbred mice bearing the wild-type allele and C57BL/6J-Tas1r3tm1Rfm mice lacking the entire Tas1r3 coding region and devoid of the T1R3 protein (Tas1r3-/-. Compared with Tas1r3+/+ mice, Tas1r3-/- mice lacked attraction to sucrose in brief-access licking tests, had diminished taste preferences for sucrose solutions in the two-bottle tests, and had reduced insulin sensitivity and tolerance to glucose administered intraperitoneally or intragastrically, which suggests that these effects are due to absence of T1R3. Impairment of glucose clearance in Tas1r3-/- mice was exacerbated with age after intraperitoneal but not intragastric administration of glucose, pointing to a compensatory role of extraoral T1R3-dependent mechanisms in offsetting age-dependent decline in regulation of glucose homeostasis. Incretin effects were similar in Tas1r3+/+ and Tas1r3-/- mice, which suggests that control of blood glucose clearance is associated with effects of extraoral T1R3 in tissues other than the gastrointestinal tract. Collectively, the obtained data demonstrate that the T1R3 receptor protein plays an important role in control of glucose homeostasis not only by regulating sugar intake but also via its extraoral function, probably in the pancreas and brain.

  5. Influenza virus-induced alterations of cytochrome P-450 enzyme activities following exposure of mice to coal and diesel particulates.

    Science.gov (United States)

    Rabovsky, J; Judy, D J; Rodak, D J; Petersen, M

    1986-06-01

    We have investigated a relationship between two detoxication systems, metabolic detoxication through the cytochrome P-450 (P-450) pathway and resistance to infection through interferon (IFN), in mice infected with influenza virus following exposure to coal dust (CD) and diesel exhaust (DE) particulates. Mice were exposed by inhalation to filtered air (FA; control), CD, or DE for 1 month and then inoculated intranasally (IN) with influenza virus. During infection, 7-ethoxycoumarin deethylase (7ECdeEt'ase) and ethylmorphine demethylase (EMdeMe'ase) (monooxygenases), and NADPH cytochrome c reductase (NADPH c red'ase) were measured in liver microsomes. Temporal patterns of enzyme activities were observed with control animals. EMdeMe'ase and NADPH c red'ase exhibited peak values at Day 4 postinfection (27.6 and 482 nmole/min/mg protein, respectively), compared to initial activities (9.1 and 307 nmole/min/mg protein, respectively). 7ECdeEt'ase activity decreased between Days 1-3 postvirus infection and thereafter returned to the original value (1.7 nmole/min/mg protein). When the mice were first exposed to CD or DE particulates for 1 month prior to influenza infection, changes in enzyme temporal patterns were observed. The increased EMdeMe'ase activity at Day 4 was not observed in mice exposed to CD and was reduced in mice exposed to DE. Preexposure to either particulate resulted in the abolition of the increased Day 4 activity of NADPH c red'ase. The 7ECdeEt'ase postinfection temporal pattern was not affected by a preexposure to either particulate. Estimates of the enzyme activities after the 1-month exposure to FA, CD, or DE but before virus infection indicated no changes due to particulate exposure alone. Under these conditions of particulate exposure and virus infection, serum IFN levels in the mice used in this study peaked at Days 4-5 and were unaffected by the 1-month preexposure to CD or DE (Hahon et al., (1985). The data suggest the relationship that exists

  6. Mice lacking liver-specific β-catenin develop steatohepatitis and fibrosis after iron overload.

    Science.gov (United States)

    Preziosi, Morgan E; Singh, Sucha; Valore, Erika V; Jung, Grace; Popovic, Branimir; Poddar, Minakshi; Nagarajan, Shanmugam; Ganz, Tomas; Monga, Satdarshan P

    2017-08-01

    Iron overload disorders such as hereditary hemochromatosis and iron loading anemias are a common cause of morbidity from liver diseases and increase risk of hepatic fibrosis and hepatocellular carcinoma (HCC). Treatment options for iron-induced damage are limited, partly because there is lack of animal models of human disease. Therefore, we investigated the effect of iron overload in liver-specific β-catenin knockout mice (KO), which are susceptible to injury, fibrosis and tumorigenesis following chemical carcinogen exposure. Iron overload diet was administered to KO and littermate control (CON) mice for various times. To ameliorate an oxidant-mediated component of tissue injury, N-Acetyl-L-(+)-cysteine (NAC) was added to drinking water of mice on iron overload diet. KO on iron diet (KO +Fe) exhibited remarkable inflammation, followed by steatosis, oxidative stress, fibrosis, regenerating nodules and occurrence of occasional HCC. Increased injury in KO +Fe was associated with activated protein kinase B (AKT), ERK, and NF-κB, along with reappearance of β-catenin and target gene Cyp2e1, which promoted lipid peroxidation and hepatic damage. Addition of NAC to drinking water protected KO +Fe from hepatic steatosis, injury and fibrosis, and prevented activation of AKT, ERK, NF-κB and reappearance of β-catenin. The absence of hepatic β-catenin predisposes mice to hepatic injury and fibrosis following iron overload, which was reminiscent of hemochromatosis and associated with enhanced steatohepatitis and fibrosis. Disease progression was notably alleviated by antioxidant therapy, which supports its chemopreventive role in the management of chronic iron overload disorders. Lack of animal models for iron overload disorders makes it hard to study the disease process for improving therapies. Feeding high iron diet to mice that lack the β-catenin gene in liver cells led to increased inflammation followed by fat accumulation, cell death and wound healing that mimicked

  7. Lack of mitochondrial trifunctional protein in mice causes neonatal hypoglycemia and sudden death

    OpenAIRE

    Ibdah, Jamal A.; Paul, Hyacinth; Zhao, Yiwen; Binford, Scott; Salleng, Ken; Cline, Mark; Matern, Dietrich; Bennett, Michael J.; Rinaldo, Piero; Strauss, Arnold W.

    2001-01-01

    Mitochondrial trifunctional protein (MTP) is a hetero-octamer of four α and four β subunits that catalyzes the final three steps of mitochondrial long chain fatty acid β-oxidation. Human MTP deficiency causes Reye-like syndrome, cardiomyopathy, or sudden unexpected death. We used gene targeting to generate an MTP α subunit null allele and to produce mice that lack MTP α and β subunits. The Mtpa–/– fetuses accumulate long chain fatty acid metabolites and have low birth weight compared with the...

  8. Sociability Deficits and Altered Amygdala Circuits in Mice Lacking Pcdh10, an Autism Associated Gene.

    Science.gov (United States)

    Schoch, Hannah; Kreibich, Arati S; Ferri, Sarah L; White, Rachel S; Bohorquez, Dominique; Banerjee, Anamika; Port, Russell G; Dow, Holly C; Cordero, Lucero; Pallathra, Ashley A; Kim, Hyong; Li, Hongzhe; Bilker, Warren B; Hirano, Shinji; Schultz, Robert T; Borgmann-Winter, Karin; Hahn, Chang-Gyu; Feldmeyer, Dirk; Carlson, Gregory C; Abel, Ted; Brodkin, Edward S

    2017-02-01

    Behavioral symptoms in individuals with autism spectrum disorder (ASD) have been attributed to abnormal neuronal connectivity, but the molecular bases of these behavioral and brain phenotypes are largely unknown. Human genetic studies have implicated PCDH10, a member of the δ2 subfamily of nonclustered protocadherin genes, in ASD. PCDH10 expression is enriched in the basolateral amygdala, a brain region implicated in the social deficits of ASD. Previous reports indicate that Pcdh10 plays a role in axon outgrowth and glutamatergic synapse elimination, but its roles in social behaviors and amygdala neuronal connectivity are unknown. We hypothesized that haploinsufficiency of Pcdh10 would reduce social approach behavior and alter the structure and function of amygdala circuits. Mice lacking one copy of Pcdh10 (Pcdh10 +/- ) and wild-type littermates were assessed for social approach and other behaviors. The lateral/basolateral amygdala was assessed for dendritic spine number and morphology, and amygdala circuit function was studied using voltage-sensitive dye imaging. Expression of Pcdh10 and N-methyl-D-aspartate receptor (NMDAR) subunits was assessed in postsynaptic density fractions of the amygdala. Male Pcdh10 +/- mice have reduced social approach behavior, as well as impaired gamma synchronization, abnormal spine morphology, and reduced levels of NMDAR subunits in the amygdala. Social approach deficits in Pcdh10 +/- male mice were rescued with acute treatment with the NMDAR partial agonist d-cycloserine. Our studies reveal that male Pcdh10 +/- mice have synaptic and behavioral deficits, and establish Pcdh10 +/- mice as a novel genetic model for investigating neural circuitry and behavioral changes relevant to ASD. Copyright © 2016 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.

  9. Lack of bcr and abr promotes hypoxia-induced pulmonary hypertension in mice.

    Directory of Open Access Journals (Sweden)

    Min Yu

    Full Text Available Bcr and Abr are GTPase activating proteins that specifically downregulate activity of the small GTPase Rac in restricted cell types in vivo. Rac1 is expressed in smooth muscle cells, a critical cell type involved in the pathogenesis of pulmonary hypertension. The molecular mechanisms that underlie hypoxia-associated pulmonary hypertension are not well-defined.Bcr and abr null mutant mice were compared to wild type controls for the development of pulmonary hypertension after exposure to hypoxia. Also, pulmonary arterial smooth muscle cells from those mice were cultured in hypoxia and examined for proliferation, p38 activation and IL-6 production. Mice lacking Bcr or Abr exposed to hypoxia developed increased right ventricular pressure, hypertrophy and pulmonary vascular remodeling. Perivascular leukocyte infiltration in the lungs was increased, and under hypoxia bcr-/- and abr-/- macrophages generated more reactive oxygen species. Consistent with a contribution of inflammation and oxidative stress in pulmonary hypertension-associated vascular damage, Bcr and Abr-deficient animals showed elevated endothelial leakage after hypoxia exposure. Hypoxia-treated pulmonary arterial smooth muscle cells from Bcr- or Abr-deficient mice also proliferated faster than those of wild type mice. Moreover, activated Rac1, phosphorylated p38 and interleukin 6 were increased in these cells in the absence of Bcr or Abr. Inhibition of Rac1 activation with Z62954982, a novel Rac inhibitor, decreased proliferation, p38 phosphorylation and IL-6 levels in pulmonary arterial smooth muscle cells exposed to hypoxia.Bcr and Abr play a critical role in down-regulating hypoxia-induced pulmonary hypertension by deactivating Rac1 and, through this, reducing both oxidative stress generated by leukocytes as well as p38 phosphorylation, IL-6 production and proliferation of pulmonary arterial smooth muscle cells.

  10. Spdef null mice lack conjunctival goblet cells and provide a model of dry eye.

    Science.gov (United States)

    Marko, Christina K; Menon, Balaraj B; Chen, Gang; Whitsett, Jeffrey A; Clevers, Hans; Gipson, Ilene K

    2013-07-01

    Goblet cell numbers decrease within the conjunctival epithelium in drying and cicatrizing ocular surface diseases. Factors regulating goblet cell differentiation in conjunctival epithelium are unknown. Recent data indicate that the transcription factor SAM-pointed domain epithelial-specific transcription factor (Spdef) is essential for goblet cell differentiation in tracheobronchial and gastrointestinal epithelium of mice. Using Spdef(-/-) mice, we determined that Spdef is required for conjunctival goblet cell differentiation and that Spdef(-/-) mice, which lack conjunctival goblet cells, have significantly increased corneal surface fluorescein staining and tear volume, a phenotype consistent with dry eye. Microarray analysis of conjunctival epithelium in Spdef(-/-) mice revealed down-regulation of goblet cell-specific genes (Muc5ac, Tff1, Gcnt3). Up-regulated genes included epithelial cell differentiation/keratinization genes (Sprr2h, Tgm1) and proinflammatory genes (Il1-α, Il-1β, Tnf-α), all of which are up-regulated in dry eye. Interestingly, four Wnt pathway genes were down-regulated. SPDEF expression was significantly decreased in the conjunctival epithelium of Sjögren syndrome patients with dry eye and decreased goblet cell mucin expression. These data demonstrate that Spdef is required for conjunctival goblet cell differentiation and down-regulation of SPDEF may play a role in human dry eye with goblet cell loss. Spdef(-/-) mice have an ocular surface phenotype similar to that in moderate dry eye, providing a new, more convenient model for the disease. Copyright © 2013 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.

  11. Mice lacking cyclin-dependent kinase-like 5 manifest autistic and ADHD-like behaviors.

    Science.gov (United States)

    Jhang, Cian-Ling; Huang, Tzyy-Nan; Hsueh, Yi-Ping; Liao, Wenlin

    2017-10-15

    Neurodevelopmental disorders frequently share common clinical features and appear high rate of comorbidity, such as those present in patients with attention-deficit hyperactivity disorder (ADHD) and autism spectrum disorders (ASD). While characterizing behavioral phenotypes in the mouse model of cyclin-dependent kinase-like 5 (CDKL5) disorder, a neurodevelopmental disorder caused by mutations in the X-linked gene encoding CDKL5, we found that these mice manifested behavioral phenotypes mimicking multiple key features of ASD, such as impaired social interaction and communication, as well as increased stereotypic digging behaviors. These mice also displayed hyper-locomotion, increased aggressiveness and impulsivity, plus deficits in motor and associative learning, resembling primary symptoms of ADHD. Through brain region-specific biochemical analysis, we uncovered that loss of CDKL5 disrupts dopamine synthesis and the expression of social communication-related key genes, such as forkhead-box P2 and mu-opioid receptor, in the corticostriatal circuit. Together, our findings support that CDKL5 plays a role in the comorbid features of autism and ADHD, and mice lacking CDKL5 may serve as an animal model to study the molecular and circuit mechanisms underlying autism-ADHD comorbidity. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  12. Mice lacking glutamate carboxypeptidase II develop normally, but are less susceptible to traumatic brain injury.

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    Gao, Yang; Xu, Siyi; Cui, Zhenwen; Zhang, Mingkun; Lin, Yingying; Cai, Lei; Wang, Zhugang; Luo, Xingguang; Zheng, Yan; Wang, Yong; Luo, Qizhong; Jiang, Jiyao; Neale, Joseph H; Zhong, Chunlong

    2015-07-01

    Glutamate carboxypeptidase II (GCPII) is a transmembrane zinc metallopeptidase found mainly in the nervous system, prostate and small intestine. In the nervous system, glia-bound GCPII mediates the hydrolysis of the neurotransmitter N-acetylaspartylglutamate (NAAG) into glutamate and N-acetylaspartate. Inhibition of GCPII has been shown to attenuate excitotoxicity associated with enhanced glutamate transmission under pathological conditions. However, different strains of mice lacking the GCPII gene are reported to exhibit striking phenotypic differences. In this study, a GCPII gene knockout (KO) strategy involved removing exons 3-5 of GCPII. This generated a new GCPII KO mice line with no overt differences in standard neurological behavior compared to their wild-type (WT) littermates. However, GCPII KO mice were significantly less susceptible to moderate traumatic brain injury (TBI). GCPII gene KO significantly lessened neuronal degeneration and astrocyte damage in the CA2 and CA3 regions of the hippocampus 24 h after moderate TBI. In addition, GCPII gene KO reduced TBI-induced deficits in long-term spatial learning/memory tested in the Morris water maze and motor balance tested via beam walking. Knockout of the GCPII gene is not embryonic lethal and affords histopathological protection with improved long-term behavioral outcomes after TBI, a result that further validates GCPII as a target for drug development consistent with results from studies using GCPII peptidase inhibitors. © 2015 International Society for Neurochemistry.

  13. Mutant Mice Lacking the p53 C-Terminal Domain Model Telomere Syndromes

    Directory of Open Access Journals (Sweden)

    Iva Simeonova

    2013-06-01

    Full Text Available Mutations in p53, although frequent in human cancers, have not been implicated in telomere-related syndromes. Here, we show that homozygous mutant mice expressing p53Δ31, a p53 lacking the C-terminal domain, exhibit increased p53 activity and suffer from aplastic anemia and pulmonary fibrosis, hallmarks of syndromes caused by short telomeres. Indeed, p53Δ31/Δ31 mice had short telomeres and other phenotypic traits associated with the telomere disease dyskeratosis congenita and its severe variant the Hoyeraal-Hreidarsson syndrome. Heterozygous p53+/Δ31 mice were only mildly affected, but decreased levels of Mdm4, a negative regulator of p53, led to a dramatic aggravation of their symptoms. Importantly, several genes involved in telomere metabolism were downregulated in p53Δ31/Δ31 cells, including Dyskerin, Rtel1, and Tinf2, which are mutated in dyskeratosis congenita, and Terf1, which is implicated in aplastic anemia. Together, these data reveal that a truncating mutation can activate p53 and that p53 plays a major role in the regulation of telomere metabolism.

  14. ROLE OF LEPTIN ON CYTOCHROME P-450 AND SOME LIVER MICROSOMAL ENZYMES ACTIVITIES IN THE OBESE AND LEAN MICE

    International Nuclear Information System (INIS)

    HEBEISHY, M.I.A.; MAZEN, G.M.A.; SHAHIN, M.I

    2008-01-01

    Leptin is a hormone that is secreted by adipocytes and regulates body weight through its effect on satiety and energy metabolism. The obese mouse is deficient in this protein and is characterized by obesity and other metabolic disorders. This study investigated the alterations of several hepatic cytochrome P 4 -5 0 (CYP), conjugation and antioxidant enzymes in lean and obese mice and the role of leptin in the modulation of these enzymes. Lean and obese male mice were injected with leptin (100 μg / rat) for 15 days. The obtained results revealed that administration of leptin to lean mice caused a significant elevation in the level of blood glucose, serum insulin, 6α, 6β, 16α- hydroxylation of testosterone, the activity of CYP 1 A 1 , CYP 4 A and GSH reductase in liver microsomes while serum corticosterone and the activity of total GSH were significantly decreased when compared to lean control mice. Moreover, obese mice treated with leptin recorded significant reduction in body weight, blood glucose concentration, serum levels of insulin and corticosterone, 7α and 16α- hydroxylation of testosterone, the activity of CYP 1A 1, CYP 2 B 1 and CYP 4 A and GST in liver microsomes. On the other hand, 6α, 6β-hydroxylation of testosterone, the activity of CYP 2 E 1 and GSH reductase in liver microsome were significantly increased when compared to obese control mice. The mechanism for the observed alterations may be due to direct leptin effects or via indirect alterations in insulin, corticosterone and/or growth hormone

  15. In vivo cytochrome P450 activity alterations in diabetic nonalcoholic steatohepatitis mice

    OpenAIRE

    Li, Hui; Clarke, John D.; Dzierlenga, Anika L.; Bear, John; Goedken, Michael J.; Cherrington, Nathan J.

    2016-01-01

    Nonalcoholic steatohepatitis (NASH) has been identified as a source of significant interindividual variation in drug metabolism. A previous ex vivo study demonstrated significant changes in hepatic Cytochrome P450 (CYP) activity in human NASH. This study evaluated the in vivo activities of multiple CYP isoforms simultaneously in prominent diabetic NASH mouse models. The pharmacokinetics of CYP selective substrates: caffeine, losartan, and omeprazole changed significantly in a diabetic NASH mo...

  16. Lack of liver glycogen causes hepatic insulin resistance and steatosis in mice.

    Science.gov (United States)

    Irimia, Jose M; Meyer, Catalina M; Segvich, Dyann M; Surendran, Sneha; DePaoli-Roach, Anna A; Morral, Nuria; Roach, Peter J

    2017-06-23

    Disruption of the Gys2 gene encoding the liver isoform of glycogen synthase generates a mouse strain (LGSKO) that almost completely lacks hepatic glycogen, has impaired glucose disposal, and is pre-disposed to entering the fasted state. This study investigated how the lack of liver glycogen increases fat accumulation and the development of liver insulin resistance. Insulin signaling in LGSKO mice was reduced in liver, but not muscle, suggesting an organ-specific defect. Phosphorylation of components of the hepatic insulin-signaling pathway, namely IRS1, Akt, and GSK3, was decreased in LGSKO mice. Moreover, insulin stimulation of their phosphorylation was significantly suppressed, both temporally and in an insulin dose response. Phosphorylation of the insulin-regulated transcription factor FoxO1 was somewhat reduced and insulin treatment did not elicit normal translocation of FoxO1 out of the nucleus. Fat overaccumulated in LGSKO livers, showing an aberrant distribution in the acinus, an increase not explained by a reduction in hepatic triglyceride export. Rather, when administered orally to fasted mice, glucose was directed toward hepatic lipogenesis as judged by the activity, protein levels, and expression of several fatty acid synthesis genes, namely, acetyl-CoA carboxylase, fatty acid synthase, SREBP1c, chREBP, glucokinase, and pyruvate kinase. Furthermore, using cultured primary hepatocytes, we found that lipogenesis was increased by 40% in LGSKO cells compared with controls. Of note, the hepatic insulin resistance was not associated with increased levels of pro-inflammatory markers. Our results suggest that loss of liver glycogen synthesis diverts glucose toward fat synthesis, correlating with impaired hepatic insulin signaling and glucose disposal. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

  17. Selective reward deficit in mice lacking beta-endorphin and enkephalin.

    Science.gov (United States)

    Hayward, Michael D; Pintar, John E; Low, Malcolm J

    2002-09-15

    It has been impossible to unequivocally identify which endogenous opioids modulate the incentive value of rewarding stimuli because these peptides are not highly selective for any single opioid receptor subtype. Here, we present evidence based on the measurement of instrumental behavior of beta-endorphin and enkephalin knock-out mice that both opioid peptides play a positive role. A progressive ratio schedule was used to measure how hard an animal would work for food reinforcers. The loss of either opioid reduced responding under this schedule, regardless of the palatability of the three different formulas of reinforcers used. The phenotype of mice lacking both endogenous opioids was nearly identical to the phenotype of mice mutant for either individual opioid. Responses were tested in nondeprived and deprived feeding states but were reduced in beta-endorphin- and enkephalin-deficient mice only when they were maintained under nondeprived conditions. Other operant manipulations ruled out variables that might contribute nonspecifically to this result such as differences in acquisition, early satiation, motor performance deficit, and reduced resistance to extinction. In contrast to the effects on instrumental performance, the loss of either or both endogenous opioids did not influence preference for water flavored with sucrose or saccharin in a two-bottle free-choice drinking paradigm. We conclude that both beta-endorphin and enkephalin positively contribute to the incentive-motivation to acquire food reinforcers. Because the attenuation of operant responding was observed only during a nondeprived motivational state, the hedonics of feeding are likely altered rather than energy homeostasis.

  18. Analgesic tone conferred by constitutively active mu opioid receptors in mice lacking β-arrestin 2

    Directory of Open Access Journals (Sweden)

    Hales Tim G

    2011-04-01

    Full Text Available Abstract Hedonic reward, dependence and addiction are unwanted effects of opioid analgesics, linked to the phasic cycle of μ opioid receptor activation, tolerance and withdrawal. In vitro studies of recombinant G protein coupled receptors (GPCRs over expressed in cell lines reveal an alternative tonic signaling mechanism that is independent of agonist. Such studies demonstrate that constitutive GPCR signaling can be inhibited by inverse agonists but not by neutral antagonists. However, ligand-independent activity has been difficult to examine in vivo, at the systems level, due to relatively low levels of constitutive activity of most GPCRs including μ receptors, often necessitating mutagenesis or pharmacological manipulation to enhance basal signaling. We previously demonstrated that the absence of β-arrestin 2 (β-arr2 augments the constitutive coupling of μ receptors to voltage-activated Ca2+ channels in primary afferent dorsal root ganglion neurons from β-arr2-/- mice. We used this in vitro approach to characterize neutral competitive antagonists and inverse agonists of the constitutively active wild type μ receptors in neurons. We administered these agents to β-arr2-/- mice to explore the role of constitutive μ receptor activity in nociception and hedonic tone. This study demonstrates that the induction of constitutive μ receptor activity in vivo in β-arr2-/- mice prolongs tail withdrawal from noxious heat, a phenomenon that was reversed by inverse agonists, but not by antagonists that lack negative efficacy. By contrast, the aversive effects of inverse agonists were similar in β-arr2-/- and β-arr2+/+ mice, suggesting that hedonic tone was unaffected.

  19. Influenza virus-induced alterations of cytochrome P-450 enzyme activities following exposure of mice to coal and diesel particulates

    Energy Technology Data Exchange (ETDEWEB)

    Rabovsky, J.; Judy, D.J.; Rodak, D.J.; Petersen, M.

    1986-06-01

    We have investigated a relationship between two detoxication systems, metabolic detoxication through the cytochrome P-450 (P-450) pathway and resistance to infection through interferon (IFN), in mice infected with influenza virus following exposure to coal dust (CD) and diesel exhaust (DE) particulates. Mice were exposed by inhalation to filtered air (FA; control), CD, or DE for 1 month and then inoculated intranasally (IN) with influenza virus. During infection, 7-ethoxycoumarin deethylase (7ECdeEt'ase) and ethylmorphine demethylase (EMdeMe'ase) (monooxygenases), and NADPH cytochrome c reductase (NADPH c red'ase) were measured in liver microsomes. Temporal patterns of enzyme activities were observed with control animals. EMdeMe'ase and NADPH c red'ase exhibited peak values at Day 4 postinfection (27.6 and 482 nmole/min/mg protein, respectively), compared to initial activities (9.1 and 307 nmole/min/mg protein, respectively). 7ECdeEt'ase activity decreased between Days 1-3 postvirus infection and thereafter returned to the original value (1.7 nmole/min/mg protein). When the mice were first exposed to CD or DE particulates for 1 month prior to influenza infection, changes in enzyme temporal patterns were observed. The increased EMdeMe'ase activity at Day 4 was not observed in mice exposed to CD and was reduced in mice exposed to DE. Preexposure to either particulate resulted in the abolition of the increased Day 4 activity of NADPH c red'ase. The 7ECdeEt'ase postinfection temporal pattern was not affected by a preexposure to either particulate. Estimates of the enzyme activities after the 1-month exposure to FA, CD, or DE but before virus infection indicated no changes due to particulate exposure alone. Under conditions of particulate exposure and virus infection, serum IFN levels peaked at Days 4-5 and were unaffected by the 1-month preexposure to CD or DE.

  20. ω-3 Polyunsaturated fatty acids and their cytochrome P450-derived metabolites suppress colorectal tumor development in mice.

    Science.gov (United States)

    Wang, Weicang; Yang, Jun; Nimiya, Yoshiki; Lee, Kin Sing Stephen; Sanidad, Katherine; Qi, Weipeng; Sukamtoh, Elvira; Park, Yeonhwa; Liu, Zhenhua; Zhang, Guodong

    2017-10-01

    Many studies have shown that dietary intake of ω-3 polyunsaturated fatty acids (PUFAs) reduces the risks of colorectal cancer; however, the underlying mechanisms are not well understood. Here we used a LC-MS/MS-based lipidomics to explore the role of eicosanoid signaling in the anti-colorectal cancer effects of ω-3 PUFAs. Our results showed that dietary feeding of ω-3 PUFAs-rich diets suppressed growth of MC38 colorectal tumor, and modulated profiles of fatty acids and eicosanoid metabolites in C57BL/6 mice. Notably, we found that dietary feeding of ω-3 PUFAs significantly increased levels of epoxydocosapentaenoic acids (EDPs, metabolites of ω-3 PUFA produced by cytochrome P450 enzymes) in plasma and tumor tissue of the treated mice. We further showed that systematic treatment with EDPs (dose=0.5 mg/kg per day) suppressed MC38 tumor growth in mice, with reduced expressions of pro-oncogenic genes such as C-myc, Axin2, and C-jun in tumor tissues. Together, these results support that formation of EDPs might contribute to the anti-colorectal cancer effects of ω-3 PUFAs. Copyright © 2017 Elsevier Inc. All rights reserved.

  1. ENU mutagenesis reveals a novel phenotype of reduced limb strength in mice lacking fibrillin 2.

    Directory of Open Access Journals (Sweden)

    Gaynor Miller

    2010-02-01

    Full Text Available Fibrillins 1 (FBN1 and 2 (FBN2 are components of microfibrils, microfilaments that are present in many connective tissues, either alone or in association with elastin. Marfan's syndrome and congenital contractural arachnodactyly (CCA result from dominant mutations in the genes FBN1 and FBN2 respectively. Patients with both conditions often present with specific muscle atrophy or weakness, yet this has not been reported in the mouse models. In the case of Fbn1, this is due to perinatal lethality of the homozygous null mice making measurements of strength difficult. In the case of Fbn2, four different mutant alleles have been described in the mouse and in all cases syndactyly was reported as the defining phenotypic feature of homozygotes.As part of a large-scale N-ethyl-N-nitrosourea (ENU mutagenesis screen, we identified a mouse mutant, Mariusz, which exhibited muscle weakness along with hindlimb syndactyly. We identified an amber nonsense mutation in Fbn2 in this mouse mutant. Examination of a previously characterised Fbn2-null mutant, Fbn2(fp, identified a similar muscle weakness phenotype. The two Fbn2 mutant alleles complement each other confirming that the weakness is the result of a lack of Fbn2 activity. Skeletal muscle from mutants proved to be abnormal with higher than average numbers of fibres with centrally placed nuclei, an indicator that there are some regenerating muscle fibres. Physiological tests indicated that the mutant muscle produces significantly less maximal force, possibly as a result of the muscles being relatively smaller in Mariusz mice.These findings indicate that Fbn2 is involved in integrity of structures required for strength in limb movement. As human patients with mutations in the fibrillin genes FBN1 and FBN2 often present with muscle weakness and atrophy as a symptom, Fbn2-null mice will be a useful model for examining this aspect of the disease process further.

  2. Fetal growth retardation and lack of hypotaurine in ezrin knockout mice.

    Directory of Open Access Journals (Sweden)

    Tomohiro Nishimura

    Full Text Available Ezrin is a membrane-associated cytoplasmic protein that serves to link cell-membrane proteins with the actin-based cytoskeleton, and also plays a role in regulation of the functional activities of some transmembrane proteins. It is expressed in placental trophoblasts. We hypothesized that placental ezrin is involved in the supply of nutrients from mother to fetus, thereby influencing fetal growth. The aim of this study was firstly to clarify the effect of ezrin on fetal growth and secondly to determine whether knockout of ezrin is associated with decreased concentrations of serum and placental nutrients. Ezrin knockout mice (Ez(-/- were confirmed to exhibit fetal growth retardation. Metabolome analysis of fetal serum and placental extract of ezrin knockout mice by means of capillary electrophoresis-time-of-flight mass spectrometry revealed a markedly decreased concentration of hypotaurine, a precursor of taurine. However, placental levels of cysteine and cysteine sulfinic acid (precursors of hypotaurine and taurine were not affected. Lack of hypotaurine in Ez(-/- mice was confirmed by liquid chromatography with tandem mass spectrometry. Administration of hypotaurine to heterogenous dams significantly decreased the placenta-to-maternal plasma ratio of hypotaurine in wild-type fetuses but only slightly decreased it in ezrin knockout fetuses, indicating that the uptake of hypotaurine from mother to placenta is saturable and that disruption of ezrin impairs the uptake of hypotaurine by placental trophoblasts. These results indicate that ezrin is required for uptake of hypotaurine from maternal serum by placental trophoblasts, and plays an important role in fetal growth.

  3. Hematopoietic Kit Deficiency, rather than Lack of Mast Cells, Protects Mice from Obesity and Insulin Resistance.

    Science.gov (United States)

    Gutierrez, Dario A; Muralidhar, Sathya; Feyerabend, Thorsten B; Herzig, Stephan; Rodewald, Hans-Reimer

    2015-05-05

    Obesity, insulin resistance, and related pathologies are associated with immune-mediated chronic inflammation. Kit mutant mice are protected from diet-induced obesity and associated co-morbidities, and this phenotype has previously been attributed to their lack of mast cells. We performed a comprehensive metabolic analysis of Kit-dependent Kit(W/Wv) and Kit-independent Cpa3(Cre/+) mast-cell-deficient mouse strains, employing diet-induced or genetic (Lep(Ob/Ob) background) models of obesity. Our results show that mast cell deficiency, in the absence of Kit mutations, plays no role in the regulation of weight gain or insulin resistance. Moreover, we provide evidence that the metabolic phenotype observed in Kit mutant mice, while independent of mast cells, is immune regulated. Our data underscore the value of definitive mast cell deficiency models to conclusively test the involvement of this enigmatic cell in immune-mediated pathologies and identify Kit as a key hematopoietic factor in the pathogenesis of metabolic syndrome. Copyright © 2015 Elsevier Inc. All rights reserved.

  4. Differentially expressed genes in embryonic cardiac tissues of mice lacking Folr1 gene activity

    Directory of Open Access Journals (Sweden)

    Schwartz Robert J

    2007-11-01

    Full Text Available Abstract Background Heart anomalies are the most frequently observed among all human congenital defects. As with the situation for neural tube defects (NTDs, it has been demonstrated that women who use multivitamins containing folic acid peri-conceptionally have a reduced risk for delivering offspring with conotruncal heart defects 123. Cellular folate transport is mediated by a receptor or binding protein and by an anionic transporter protein system. Defective function of the Folr1 (also known as Folbp1; homologue of human FRα gene in mice results in inadequate transport, accumulation, or metabolism of folate during cardiovascular morphogenesis. Results We have observed cardiovascular abnormalities including outflow tract and aortic arch arterial defects in genetically compromised Folr1 knockout mice. In order to investigate the molecular mechanisms underlying the failure to complete development of outflow tract and aortic arch arteries in the Folr1 knockout mouse model, we examined tissue-specific gene expression difference between Folr1 nullizygous embryos and morphologically normal heterozygous embryos during early cardiac development (14-somite stage, heart tube looping (28-somite stage, and outflow track septation (38-somite stage. Microarray analysis was performed as a primary screening, followed by investigation using quantitative real-time PCR assays. Gene ontology analysis highlighted the following ontology groups: cell migration, cell motility and localization of cells, structural constituent of cytoskeleton, cell-cell adhesion, oxidoreductase, protein folding and mRNA processing. This study provided preliminary data and suggested potential candidate genes for further description and investigation. Conclusion The results suggested that Folr1 gene ablation and abnormal folate homeostasis altered gene expression in developing heart and conotruncal tissues. These changes affected normal cytoskeleton structures, cell migration and

  5. Effects of MicroRNA-34a on the Pharmacokinetics of Cytochrome P450 Probe Drugs in Mice.

    Science.gov (United States)

    Jilek, Joseph L; Tian, Ye; Yu, Ai-Ming

    2017-05-01

    MicroRNAs (miRNAs or miRs), including miR-34a, have been shown to regulate nuclear receptor, drug-metabolizing enzyme, and transporter gene expression in various cell model systems. However, to what degree miRNAs affect pharmacokinetics (PK) at the systemic level remains unknown. In addition, miR-34a replacement therapy represents a new cancer treatment strategy, although it is unknown whether miR-34a therapeutic agents could elicit any drug-drug interactions. To address this question, we refined a practical single-mouse PK approach and investigated the effects of a bioengineered miR-34a agent on the PK of several cytochrome P450 probe drugs (midazolam, dextromethorphan, phenacetin, diclofenac, and chlorzoxazone) administered as a cocktail. This approach involves manual serial blood microsampling from a single mouse and requires a sensitive liquid chromatography-tandem mass spectrometry assay, which was able to illustrate the sharp changes in midazolam PK by ketoconazole and pregnenolone 16 α -carbonitrile as well as phenacetin PK by α -naphthoflavone and 3-methylcholanthrene. Surprisingly, 3-methylcholanthrene also decreased systemic exposure to midazolam, whereas both pregnenolone 16 α -carbonitrile and 3-methylcholanthrene largely reduced the exposure to dextromethorphan, diclofenac, and chlorzoxazone. Finally, the biologic miR-34a agent had no significant effects on the PK of cocktail drugs but caused a marginal (45%-48%) increase in systemic exposure to midazolam, phenacetin, and dextromethorphan in mice. In vitro validation of these data suggested that miR-34a slightly attenuated intrinsic clearance of dextromethorphan. These findings from single-mouse PK and corresponding mouse liver microsome models suggest that miR-34a might have minor or no effects on the PK of coadministered cytochrome P450-metabolized drugs. Copyright © 2017 by The American Society for Pharmacology and Experimental Therapeutics.

  6. Defective bile salt biosynthesis and hydroxylation in mice with reduced cytochrome P450 activity

    NARCIS (Netherlands)

    Kunne, Cindy; Acco, Alexandra; Hohenester, Simon; Duijst, Suzanne; de Waart, Dirk R.; Zamanbin, Alaleh; Oude Elferink, Ronald P. J.

    2013-01-01

    The difference in bile salt (BS) composition between rodents and humans is mainly caused by formation of muricholate in rodents as well as by efficient rehydroxylation of deoxycholic acid. The aim of this study was to characterize bile formation in a mouse model (Hrn mice) with hepatic disruption of

  7. Early signs of pathological cognitive aging in mice lacking high-affinity nicotinic receptors.

    Directory of Open Access Journals (Sweden)

    Eleni eKonsolaki

    2016-04-01

    Full Text Available In order to address pathological cognitive decline effectively, it is critical to adopt early preventive measures in individuals considered at risk. It is therefore essential to develop approaches that identify such individuals before the onset of irreversible dementia. Α deficient cholinergic system has been consistently implicated as one of the main factors associated with a heightened vulnerability to the aging process. In the present study we used mice lacking high affinity nicotinic receptors (β2-/-, which have been proposed as an animal model of accelerated/premature cognitive aging. Our aim was to identify behavioural signs that could serve as indicators or predictors of impending cognitive decline. We used test batteries in order to assess cognitive functions and additional tasks to investigate spontaneous behaviours, such as species-specific activities and exploration/locomotion in a novel environment. Our data confirm and extend the hypothesis that β2-/- animals exhibit age-related cognitive impairments, manifested in both spatial learning and recognition memory tasks. In addition, we reveal deficits in spontaneous behaviour and habituation processes earlier in life. To our knowledge, this is the first study to perform an extensive behavioural examination of an animal model of premature cognitive aging, and our results suggest that β2-nAChR dependent cognitive deterioration progressively evolves from initial subtle behavioural changes to global dementia due to the combined effect of the neuropathology and aging.

  8. Mice lacking Brinp2 or Brinp3, or both, exhibit behaviours consistent with neurodevelopmental disorders

    Directory of Open Access Journals (Sweden)

    Susie Ruth Berkowicz

    2016-10-01

    Full Text Available Background: Brinps 1 – 3, and Astrotactins (Astn 1 and 2, are members of the Membrane Attack Complex / Perforin (MACPF superfamily that are predominantly expressed in the mammalian brain during development. Genetic variation at the human BRINP2/ASTN1 and BRINP1/ASTN2 loci has been implicated in neurodevelopmental disorders. We, and others, have previously shown that Brinp1-/- mice exhibit behaviour reminiscent of autism spectrum disorder (ASD and attention deficit hyperactivity disorder (ADHD.Method: We created Brinp2-/- mice and Brinp3-/- mice via the Cre-mediated LoxP system to investigate the effect of gene deletion on anatomy and behaviour. Additionally, Brinp2-/-Brinp3-/- double knock-out mice were generated by interbreeding Brinp2-/- and Brinp3-/- mice. Genomic validation was carried out for each knock-out line, followed by histological, weight and behavioural examination. Brinp1-/-Brinp2-/-Brinp3-/- triple knock-out mice were also generated by crossing Brinp2/3 double knock-out mice with previously generated Brinp1-/- mice, and examined by weight and histological analysis.Results: Brinp2-/- and Brinp3-/- mice differ in their behaviour: Brinp2-/- mice are hyperactive, whereas Brinp3-/- mice exhibit marked changes in anxiety-response on the elevated plus maze. Brinp3-/- mice also show evidence of altered sociability. Both Brinp2-/- and Brinp3-/- mice have normal short-term memory, olfactory responses, pre-pulse inhibition and motor learning. The double knock-out mice show behaviours of Brinp2-/- and Brinp3-/- mice, without evidence of new or exacerbated phenotypes. Conclusion: Brinp3 is important in moderation of anxiety, with potential relevance to anxiety disorders. Brinp2 dysfunction resulting in hyperactivity may be relevant to the association of ADHD with chromosome locus 1q25.2. Brinp2-/- and Brinp3-/- genes do not compensate in the mammalian brain and likely have distinct molecular or cell-type specific functions.

  9. Mice lacking the p43 mitochondrial T3 receptor become glucose intolerant and insulin resistant during aging.

    Directory of Open Access Journals (Sweden)

    Christelle Bertrand

    Full Text Available Thyroid hormones (TH play an important regulatory role in energy expenditure regulation and are key regulators of mitochondrial activity. We have previously identified a mitochondrial triiodothyronine (T3 receptor (p43 which acts as a mitochondrial transcription factor of the organelle genome, which leads in vitro and in vivo, to a stimulation of mitochondrial biogenesis. Recently, we generated mice carrying a specific p43 invalidation. At 2 months of age, we reported that p43 depletion in mice induced a major defect in insulin secretion both in vivo and in isolated pancreatic islets, and a loss of glucose-stimulated insulin secretion. The present study was designed to determine whether p43 invalidation influences life expectancy and modulates blood glucose and insulin levels as well as glucose tolerance or insulin sensitivity during aging. We report that from 4 months old onwards, mice lacking p43 are leaner than wild-type mice. p43-/- mice also have a moderate reduction of life expectancy compared to wild type. We found no difference in blood glucose levels, excepted at 24 months old where p43-/- mice showed a strong hyperglycemia in fasting conditions compared to controls animals. However, the loss of glucose-stimulated insulin secretion was maintained whatever the age of mice lacking p43. If up to 12 months old, glucose tolerance remained unchanged, beyond this age p43-/- mice became increasingly glucose intolerant. In addition, if up to 12 months old p43 deficient animals were more sensitive to insulin, after this age we observed a loss of this capacity, culminating in 24 months old mice with a decreased sensitivity to the hormone. In conclusion, we demonstrated that during aging the depletion of the mitochondrial T3 receptor p43 in mice progressively induced an increased glycemia in the fasted state, glucose intolerance and an insulin-resistance several features of type-2 diabetes.

  10. Sex-dependent alteration of cardiac cytochrome P450 gene expression by doxorubicin in C57Bl/6 mice.

    Science.gov (United States)

    Grant, Marianne K O; Seelig, Davis M; Sharkey, Leslie C; Zordoky, Beshay N

    2017-01-01

    There is inconclusive evidence about the role of sex as a risk factor for doxorubicin (DOX)-induced cardiotoxicity. Recent experimental studies have shown that adult female rats are protected against DOX-induced cardiotoxicity. However, the mechanisms of this sexual dimorphism are not fully elucidated. We have previously demonstrated that DOX alters the expression of several cytochrome P450 (CYP) enzymes in the hearts of male rats. Nevertheless, the sex-dependent effect of DOX on the expression of CYP enzymes is still not known. Therefore, in the present study, we determined the effect of acute DOX exposure on the expression of CYP genes in the hearts of both male and female C57Bl/6 mice. Acute DOX cardiotoxicity was induced by a single intraperitoneal injection of 20 mg/kg DOX in male and female adult C57Bl/6 mice. Cardiac function was assessed 5 days after DOX exposure by trans-thoracic echocardiography. Mice were euthanized 1 day or 6 days after DOX or saline injection. Thereafter, the hearts were harvested and weighed. Heart sections were evaluated for pathological lesions. Total RNA was extracted and expression of natriuretic peptides, inflammatory and apoptotic markers, and CYP genes was measured by real-time PCR. Adult female C57Bl/6 mice were protected from acute DOX-induced cardiotoxicity as they show milder pathological lesions, less inflammation, and faster recovery from DOX-induced apoptosis and DOX-mediated inhibition of beta-type natriuretic peptide. Acute DOX exposure altered the gene expression of multiple CYP genes in a sex-dependent manner. In 24 h, DOX exposure caused male-specific induction of Cyp1b1 and female-specific induction of Cyp2c29 and Cyp2e1. Acute DOX exposure causes sex-dependent alteration of cardiac CYP gene expression. Since cardiac CYP enzymes metabolize several endogenous compounds to biologically active metabolites, sex-dependent alteration of CYP genes may play a role in the sexual dimorphism of acute DOX

  11. Mice lacking caspase-2 are protected from behavioral changes, but not pathology, in the YAC128 model of Huntington disease

    Directory of Open Access Journals (Sweden)

    Bissada Nagat

    2011-08-01

    Full Text Available Abstract Background Huntington Disease (HD is a neurodegenerative disorder in which caspase activation and cleavage of substrates, including the huntingtin protein, has been invoked as a pathological mechanism. Specific changes in caspase-2 (casp2 activity have been suggested to contribute to the pathogenesis of HD, however unique casp2 cleavage substrates have remained elusive. We thus utilized mice completely lacking casp2 (casp2-/- to examine the role played by casp2 in the progression of HD. This 'substrate agnostic' approach allows us to query the effect of casp2 on HD progression without pre-defining proteolytic substrates of interest. Results YAC128 HD model mice lacking casp2 show protection from well-validated motor and cognitive features of HD, including performance on rotarod, swimming T-maze, pre-pulse inhibition, spontaneous alternation and locomotor tasks. However, the specific pathological features of the YAC128 mice including striatal volume loss and testicular degeneration are unaltered in mice lacking casp2. The application of high-resolution magnetic resonance imaging (MRI techniques validates specific neuropathology in the YAC128 mice that is not altered by ablation of casp2. Conclusions The rescue of behavioral phenotypes in the absence of pathological improvement suggests that different pathways may be operative in the dysfunction of neural circuitry in HD leading to behavioral changes compared to the processes leading to cell death and volume loss. Inhibition of caspase-2 activity may be associated with symptomatic improvement in HD.

  12. Evaluating mice lacking serum carboxylesterase as a behavioral model for nerve agent intoxication.

    Science.gov (United States)

    Dunn, Emily N; Ferrara-Bowens, Teresa M; Chachich, Mark E; Honnold, Cary L; Rothwell, Cristin C; Hoard-Fruchey, Heidi M; Lesyna, Catherine A; Johnson, Erik A; Cerasoli, Douglas M; McDonough, John H; Cadieux, C Linn

    2018-06-07

    Mice and other rodents are typically utilized for chemical warfare nerve agent research. Rodents have large amounts of carboxylesterase in their blood, while humans do not. Carboxylesterase nonspecifically binds to and detoxifies nerve agent. The presence of this natural bioscavenger makes mice and other rodents poor models for studies identifying therapeutics to treat humans exposed to nerve agents. To obviate this problem, a serum carboxylesterase knockout (Es1 KO) mouse was created. In this study, Es1 KO and wild type (WT) mice were assessed for differences in gene expression, nerve agent (soman; GD) median lethal dose (MLD) values, and behavior prior to and following nerve agent exposure. No expression differences were detected between Es1 KO and WT mice in more than 34 000 mouse genes tested. There was a significant difference between Es1 KO and WT mice in MLD values, as the MLD for GD-exposed WT mice was significantly higher than the MLD for GD-exposed Es1 KO mice. Behavioral assessments of Es1 KO and WT mice included an open field test, a zero maze, a Barnes maze, and a sucrose preference test (SPT). While sex differences were observed in various measures of these tests, overall, Es1 KO mice behaved similarly to WT mice. The two genotypes also showed virtually identical neuropathological changes following GD exposure. Es1 KO mice appear to have an enhanced susceptibility to GD toxicity while retaining all other behavioral and physiological responses to this nerve agent, making the Es1 KO mouse a more human-like model for nerve agent research.

  13. Lack of caching of direct-seeded Douglas fir seeds by deer mice

    International Nuclear Information System (INIS)

    Sullivan, T.P.

    1978-01-01

    Seed caching by deer mice was investigated by radiotagging seeds in forest and clear-cut areas in coastal British Columbia. Deer mice tend to cache very few Douglas fir seeds in the fall when the seed is uniformly distributed and is at densities comparable with those used in direct-seeding programs. (author)

  14. Mice Lacking EGR1 Have Impaired Clock Gene (BMAL1) Oscillation, Locomotor Activity, and Body Temperature.

    Science.gov (United States)

    Riedel, Casper Schwartz; Georg, Birgitte; Jørgensen, Henrik L; Hannibal, Jens; Fahrenkrug, Jan

    2018-01-01

    Early growth response transcription factor 1 (EGR1) is expressed in the suprachiasmatic nucleus (SCN) after light stimulation. We used EGR1-deficient mice to address the role of EGR1 in the clock function and light-induced resetting of the clock. The diurnal rhythms of expression of the clock genes BMAL1 and PER1 in the SCN were evaluated by semi-quantitative in situ hybridization. We found no difference in the expression of PER1 mRNA between wildtype and EGR1-deficient mice; however, the daily rhythm of BMAL1 mRNA was completely abolished in the EGR1-deficient mice. In addition, we evaluated the circadian running wheel activity, telemetric locomotor activity, and core body temperature of the mice. Loss of EGR1 neither altered light-induced phase shifts at subjective night nor affected negative masking. Overall, circadian light entrainment was found in EGR1-deficient mice but they displayed a reduced locomotor activity and an altered temperature regulation compared to wild type mice. When placed in running wheels, a subpopulation of EGR1-deficient mice displayed a more disrupted activity rhythm with no measurable endogenous period length (tau). In conclusion, the present study provides the first evidence that the circadian clock in the SCN is disturbed in mice deficient of EGR1.

  15. Characterization of spontaneous air space enlargement in mice lacking microfibrillar-associated protein 4

    DEFF Research Database (Denmark)

    Holm, Anne Trommelholt; Wulf-Johansson, Helle; Hvidsten, Svend

    2015-01-01

    to characterize the pulmonary function changes and emphysematous changes that occur in Mfap4-deficient (Mfap4(-/-)) mice. Significant changes included increases in total lung capacity and compliance, which were evident in Mfap4(-/-) mice at 6 and 8 mo but not at 3 mo of age. Using in vivo breath-hold gated...... were both significantly decreased in Mfap4(-/-) mice by 25 and 15%, respectively. The data did not support an essential role of MFAP4 in pulmonary elastic fiber organization or content but indicated increased turnover in young Mfap4(-/-) mice. However, Mfap4(-/-) mice developed a spontaneous loss...... of lung function, which was evident at 6 mo of age, and moderate air space enlargement, with emphysema-like changes....

  16. Lack of skeletal muscle IL-6 influences hepatic glucose metabolism in mice during prolonged exercise

    DEFF Research Database (Denmark)

    Bertholdt, Lærke; Gudiksen, Anders; Schwartz, Camilla Lindgren

    2017-01-01

    The liver is essential in maintaining and regulating glucose homeostasis during prolonged exercise. IL-6 has been shown to be secreted from skeletal muscle during exercise and has been suggested to signal to the liver. Therefore, the aim of this study was to investigate the role of skeletal muscle...... IL-6 on hepatic glucose regulation and substrate choice during prolonged exercise. Skeletal muscle-specific IL-6 knockout (IL-6 MKO) mice (age, 12-14 wk) and littermate lox/lox (Control) mice were either rested (Rest) or completed a single bout of exercise for 10, 60, or 120 min, and the liver....... Furthermore, IL-6 MKO mice had higher hepatic pyruvate dehydrogenase (PDH)Ser232 and PDHSer300 phosphorylation than control mice at rest. In conclusion, hepatic gluconeogenic capacity in mice is increased during prolonged exercise independent of muscle IL-6. Furthermore, Skeletal muscle IL-6 influences...

  17. Impairment of social behavior and communication in mice lacking the Uba6-dependent ubiquitin activation system.

    Science.gov (United States)

    Lee, Ji Yeon; Kwak, Minseok; Lee, Peter C W

    2015-03-15

    The Uba6-Use1 ubiquitin enzyme cascade is a poorly understood arm of the ubiquitin-proteasome system required for mouse development. Recently, we reported that Uba6 brain-specific knockout (termed NKO) mice display abnormal social behavior and neuronal development due to a decreased spine density and accumulation of Ube3a and Shank3. To better characterize a potential role for NKO mice in autism spectrum disorders (ASDs), we performed a comprehensive behavioral characterization of the social behavior and communication of NKO mice. Our behavioral results confirmed that NKO mice display social impairments, as indicated by fewer vocalizations and decreased social interaction. We conclude that UBA6 NKO mice represent a novel ASD mouse model of anti-social and less verbal behavioral symptoms. Copyright © 2014 Elsevier B.V. All rights reserved.

  18. Lack of tau proteins rescues neuronal cell death and decreases amyloidogenic processing of APP in APP/PS1 mice.

    Science.gov (United States)

    Leroy, Karelle; Ando, Kunie; Laporte, Vincent; Dedecker, Robert; Suain, Valérie; Authelet, Michèle; Héraud, Céline; Pierrot, Nathalie; Yilmaz, Zehra; Octave, Jean-Noël; Brion, Jean-Pierre

    2012-12-01

    Lack of tau expression has been reported to protect against excitotoxicity and to prevent memory deficits in mice expressing mutant amyloid precursor protein (APP) identified in familial Alzheimer disease. In APP mice, mutant presenilin 1 (PS1) enhances generation of Aβ42 and inhibits cell survival pathways. It is unknown whether the deficient phenotype induced by concomitant expression of mutant PS1 is rescued by absence of tau. In this study, we have analyzed the effect of tau deletion in mice expressing mutant APP and PS1. Although APP/PS1/tau(+/+) mice had a reduced survival, developed spatial memory deficits at 6 months and motor impairments at 12 months, these deficits were rescued in APP/PS1/tau(-/-) mice. Neuronal loss and synaptic loss in APP/PS1/tau(+/+) mice were rescued in the APP/PS1/tau(-/-) mice. The amyloid plaque burden was decreased by roughly 50% in the cortex and the spinal cord of the APP/PS1/tau(-/-) mice. The levels of soluble and insoluble Aβ40 and Aβ42, and the Aβ42/Aβ40 ratio were reduced in APP/PS1/tau(-/-) mice. Levels of phosphorylated APP, of β-C-terminal fragments (CTFs), and of β-secretase 1 (BACE1) were also reduced, suggesting that β-secretase cleavage of APP was reduced in APP/PS1/tau(-/-) mice. Our results indicate that tau deletion had a protective effect against amyloid induced toxicity even in the presence of mutant PS1 and reduced the production of Aβ. Copyright © 2012 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.

  19. Lack of phosphatidylethanolamine N-methyltransferase in mice does not promote fatty acid oxidation in skeletal muscle.

    Science.gov (United States)

    Tasseva, Guergana; van der Veen, Jelske N; Lingrell, Susanne; Jacobs, René L; Vance, Dennis E; Vance, Jean E

    2016-02-01

    Phosphatidylethanolamine N-methyltransferase (PEMT) converts phosphatidylethanolamine (PE) to phosphatidylcholine (PC) in the liver. Mice lacking PEMT are protected from high-fat diet-induced obesity and insulin resistance, and exhibit increased whole-body energy expenditure and oxygen consumption. Since skeletal muscle is a major site of fatty acid oxidation and energy utilization, we determined if rates of fatty acid oxidation/oxygen consumption in muscle are higher in Pemt(-/-) mice than in Pemt(+/+) mice. Although PEMT is abundant in the liver, PEMT protein and activity were undetectable in four types of skeletal muscle. Moreover, amounts of PC and PE in the skeletal muscle were not altered by PEMT deficiency. Thus, we concluded that any influence of PEMT deficiency on skeletal muscle would be an indirect consequence of lack of PEMT in liver. Neither the in vivo rate of fatty acid uptake by muscle nor the rate of fatty acid oxidation in muscle explants and cultured myocytes depended upon Pemt genotype. Nor did PEMT deficiency increase oxygen consumption or respiratory function in skeletal muscle mitochondria. Thus, the increased whole body oxygen consumption in Pemt(-/-) mice, and resistance of these mice to diet-induced weight gain, are not primarily due to increased capacity of skeletal muscle for utilization of fatty acids as an energy source. Crown Copyright © 2015. Published by Elsevier B.V. All rights reserved.

  20. Behavioural endophenotypes in mice lacking the auxiliary GABAB receptor subunit KCTD16.

    Science.gov (United States)

    Cathomas, Flurin; Sigrist, Hannes; Schmid, Luca; Seifritz, Erich; Gassmann, Martin; Bettler, Bernhard; Pryce, Christopher R

    2017-01-15

    Gamma-aminobutyric acid (GABA) is the major inhibitory neurotransmitter in the brain and is implicated in the pathophysiology of a number of neuropsychiatric disorders. The GABA B receptors are G-protein coupled receptors consisting of principle subunits and auxiliary potassium channel tetramerization domain (KCTD) subunits. The KCTD subunits 8, 12, 12b and 16 are cytosolic proteins that determine the kinetics of the GABA B receptor response. Previously, we demonstrated that Kctd12 null mutant mice (Kctd12 -/- ) exhibit increased auditory fear learning and that Kctd12 +/- mice show altered circadian activity, as well as increased intrinsic excitability in hippocampal pyramidal neurons. KCTD16 has been demonstrated to influence neuronal excitability by regulating GABA B receptor-mediated gating of postsynaptic ion channels. In the present study we investigated for behavioural endophenotypes in Kctd16 -/- and Kctd16 +/- mice. Compared with wild-type (WT) littermates, auditory and contextual fear conditioning were normal in both Kctd16 -/- and Kctd16 +/- mice. When fear memory was tested on the following day, Kctd16 -/- mice exhibited less extinction of auditory fear memory relative to WT and Kctd16 +/- mice, as well as more contextual fear memory relative to WT and, in particular, Kctd16 +/- mice. Relative to WT, both Kctd16 +/- and Kctd16 -/- mice exhibited normal circadian activity. This study adds to the evidence that auxillary KCTD subunits of GABA B receptors contribute to the regulation of behaviours that could constitute endophenotypes for hyper-reactivity to aversive stimuli in neuropsychiatric disorders. Copyright © 2016 Elsevier B.V. All rights reserved.

  1. Spdef Null Mice Lack Conjunctival Goblet Cells and Provide a Model of Dry Eye

    OpenAIRE

    Marko, Christina K.; Menon, Balaraj B.; Chen, Gang; Whitsett, Jeffrey A.; Clevers, Hans; Gipson, Ilene K.

    2013-01-01

    Goblet cell numbers decrease within the conjunctival epithelium in drying and cicatrizing ocular surface diseases. Factors regulating goblet cell differentiation in conjunctival epithelium are unknown. Recent data indicate that the transcription factor SAM-pointed domain epithelial-specific transcription factor (Spdef) is essential for goblet cell differentiation in tracheobronchial and gastrointestinal epithelium of mice. Using Spdef−/− mice, we determined that Spdef is required for conjunct...

  2. Time-place learning and memory persist in mice lacking functional Per1 and Per2 clock genes.

    Science.gov (United States)

    Mulder, C; Van Der Zee, E A; Hut, R A; Gerkema, M P

    2013-12-01

    With time-place learning, animals link a stimulus with the location and the time of day. This ability may optimize resource localization and predator avoidance in daily changing environments. Time-place learning is a suitable task to study the interaction of the circadian system and memory. Previously, we showed that time-place learning in mice depends on the circadian system and Cry1 and/or Cry2 clock genes. We questioned whether time-place learning is Cry specific or also depends on other core molecular clock genes. Here, we show that Per1/Per2 double mutant mice, despite their arrhythmic phenotype, acquire time-place learning similar to wild-type mice. As well as an established role in circadian rhythms, Per genes have also been implicated in the formation and storage of memory. We found no deficiencies in short-term spatial working memory in Per mutant mice compared to wild-type mice. Moreover, both Per mutant and wild-type mice showed similar long-term memory for contextual features of a paradigm (a mild foot shock), measured in trained mice after a 2-month nontesting interval. In contrast, time-place associations were lost in both wild-type and mutant mice after these 2 months, suggesting a lack of maintained long-term memory storage for this type of information. Taken together, Cry-dependent time-place learning does not require Per genes, and Per mutant mice showed no PER-specific short-term or long-term memory deficiencies. These results limit the functional role of Per clock genes in the circadian regulation of time-place learning and memory.

  3. Aberrant Bone Density in Aging Mice Lacking the Adenosine Transporter ENT1

    Science.gov (United States)

    Hinton, David J.; McGee-Lawrence, Meghan E.; Lee, Moonnoh R.; Kwong, Hoi K.; Westendorf, Jennifer J.; Choi, Doo-Sup

    2014-01-01

    Adenosine is known to regulate bone production and resorption in humans and mice. Type 1 equilibrative nucleoside transporter (ENT1) is responsible for the majority of adenosine transport across the plasma membrane and is ubiquitously expressed in both humans and mice. However, the contribution of ENT1-mediated adenosine levels has not been studied in bone remodeling. With the recent identification of the importance of adenosine signaling in bone homeostasis, it is essential to understand the role of ENT1 to develop novel therapeutic compounds for bone disorders. Here we examined the effect of ENT1 deletion on bone density using X-ray, dual energy X-ray absorptiometry and micro-computerized tomography analysis. Our results show that bone density and bone mineral density is reduced in the lower thoracic and lumbar spine as well as the femur of old ENT1 null mice (>7 months) compared to wild-type littermates. Furthermore, we found increased mRNA expression of tartrate-resistant acid phosphatase (TRAP), an osteoclast marker, in isolated long bones from 10 month old ENT1 null mice compared to wild-type mice. In addition, aged ENT1 null mice displayed severe deficit in motor coordination and locomotor activity, which might be attributed to dysregulated bone density. Overall, our study suggests that ENT1-regulated adenosine signaling plays an essential role in lumbar spine and femur bone density. PMID:24586402

  4. Aberrant bone density in aging mice lacking the adenosine transporter ENT1.

    Directory of Open Access Journals (Sweden)

    David J Hinton

    Full Text Available Adenosine is known to regulate bone production and resorption in humans and mice. Type 1 equilibrative nucleoside transporter (ENT1 is responsible for the majority of adenosine transport across the plasma membrane and is ubiquitously expressed in both humans and mice. However, the contribution of ENT1-mediated adenosine levels has not been studied in bone remodeling. With the recent identification of the importance of adenosine signaling in bone homeostasis, it is essential to understand the role of ENT1 to develop novel therapeutic compounds for bone disorders. Here we examined the effect of ENT1 deletion on bone density using X-ray, dual energy X-ray absorptiometry and micro-computerized tomography analysis. Our results show that bone density and bone mineral density is reduced in the lower thoracic and lumbar spine as well as the femur of old ENT1 null mice (>7 months compared to wild-type littermates. Furthermore, we found increased mRNA expression of tartrate-resistant acid phosphatase (TRAP, an osteoclast marker, in isolated long bones from 10 month old ENT1 null mice compared to wild-type mice. In addition, aged ENT1 null mice displayed severe deficit in motor coordination and locomotor activity, which might be attributed to dysregulated bone density. Overall, our study suggests that ENT1-regulated adenosine signaling plays an essential role in lumbar spine and femur bone density.

  5. Mice lacking prostaglandin E receptor subtype 4 manifest disrupted lipid metabolism attributable to impaired triglyceride clearance.

    Science.gov (United States)

    Cai, Yin; Ying, Fan; Song, Erfei; Wang, Yu; Xu, Aimin; Vanhoutte, Paul M; Tang, Eva Hoi-Ching

    2015-12-01

    Upon high-fat feeding, prostaglandin E receptor subtype 4 (EP4)-knockout mice gain less body weight than their EP4(+/+) littermates. We investigated the cause of the lean phenotype. The mice showed a 68.8% reduction in weight gain with diminished fat mass that was not attributable to reduced food intake, fat malabsorption, or increased energy expenditure. Plasma triglycerides in the mice were elevated by 244.9%. The increase in plasma triglycerides was independent of changes in hepatic very low density lipoprotein (VLDL)-triglyceride production or intestinal chylomicron-triglyceride synthesis. However, VLDL-triglyceride clearance was drastically impaired in the EP4-knockout mice. The absence of EP4 in mice compromised the activation of lipoprotein lipase (LPL), the key enzyme responsible for trafficking of plasma triglycerides into peripheral tissues. Deficiency in EP4 reduced hepatic mRNA expression of the transcriptional factor cAMP response element binding protein H (by 36.8%) and LPL activators, including apolipoprotein (Apo)a5 (by 40.2%) and Apoc2 (by 61.3%). In summary, the lean phenotype of EP4-deficient mice resulted from reduction in adipose tissue and accretion of other peripheral organs caused by impaired triglyceride clearance. The findings identify a new metabolic dimension in the physiologic role played by endogenous EP4. © FASEB.

  6. Minor cell-death defects but reduced tumor latency in mice lacking the BH3-only proteins Bad and Bmf.

    Science.gov (United States)

    Baumgartner, F; Woess, C; Pedit, V; Tzankov, A; Labi, V; Villunger, A

    2013-01-31

    Proapoptotic Bcl-2 family members of the Bcl-2 homology (BH)3-only subgroup are critical for the establishment and maintenance of tissue homeostasis and can mediate apoptotic cell death in response to developmental cues or exogenously induced forms of cell stress. On the basis of the biochemical experiments as well as genetic studies in mice, the BH3-only proteins Bad and Bmf have been implicated in different proapoptotic events such as those triggered by glucose- or trophic factor-deprivation, glucocorticoids, or histone deacetylase inhibition, as well as suppression of B-cell lymphomagenesis upon aberrant expression of c-Myc. To address possible redundancies in cell death regulation and tumor suppression, we generated compound mutant mice lacking both genes. Our studies revealed lack of redundancy in most paradigms of lymphocyte apoptosis tested in tissue culture. Only spontaneous cell death of thymocytes kept in low glucose or that of pre-B cells deprived of cytokines was significantly delayed when both genes were lacking. Of note, despite these minor apoptosis defects we observed compromised lymphocyte homeostasis in vivo that affected mainly the B-cell lineage. Long-term follow-up revealed significantly reduced latency to spontaneous tumor formation in aged mice when both genes were lacking. Together our study suggests that Bad and Bmf co-regulate lymphocyte homeostasis and limit spontaneous transformation by mechanisms that may not exclusively be linked to the induction of lymphocyte apoptosis.

  7. Abnormal motor phenotype at adult stages in mice lacking type 2 deiodinase.

    Science.gov (United States)

    Bárez-López, Soledad; Bosch-García, Daniel; Gómez-Andrés, David; Pulido-Valdeolivas, Irene; Montero-Pedrazuela, Ana; Obregon, Maria Jesus; Guadaño-Ferraz, Ana

    2014-01-01

    Thyroid hormones have a key role in both the developing and adult central nervous system and skeletal muscle. The thyroid gland produces mainly thyroxine (T4) but the intracellular concentrations of 3,5,3'-triiodothyronine (T3; the transcriptionally active hormone) in the central nervous system and skeletal muscle are modulated by the activity of type 2 deiodinase (D2). To date no neurological syndrome has been associated with mutations in the DIO2 gene and previous studies in young and juvenile D2-knockout mice (D2KO) did not find gross neurological alterations, possibly due to compensatory mechanisms. This study aims to analyze the motor phenotype of 3-and-6-month-old D2KO mice to evaluate the role of D2 on the motor system at adult stages in which compensatory mechanisms could have failed. Motor abilities were explored by validated tests. In the footprint test, D2KO showed an altered global gait pattern (mice walked slower, with shorter strides and with a hindlimb wider base of support than wild-type mice). No differences were detected in the balance beam test. However, a reduced latency to fall was found in the rotarod, coat-hanger and four limb hanging wire tests indicating impairment on coordination and prehensile reflex and a reduction of muscle strength. In histological analyses of cerebellum and skeletal muscle, D2KO mice did not present gross structural abnormalities. Thyroid hormones levels and deiodinases activities were also determined. In D2KO mice, despite euthyroid T3 and high T4 plasma levels, T3 levels were significantly reduced in cerebral cortex (48% reduction) and skeletal muscle (33% reduction), but not in the cerebellum where other deiodinase (type 1) is expressed. The motor alterations observed in D2KO mice indicate an important role for D2 in T3 availability to maintain motor function and muscle strength. Our results suggest a possible implication of D2 in motor disorders.

  8. Developmental alterations in motor coordination and medium spiny neuron markers in mice lacking pgc-1α.

    Directory of Open Access Journals (Sweden)

    Elizabeth K Lucas

    Full Text Available Accumulating evidence implicates the transcriptional coactivator peroxisome proliferator activated receptor γ coactivator 1α (PGC-1α in the pathophysiology of Huntington Disease (HD. Adult PGC-1α (-/- mice exhibit striatal neurodegeneration, and reductions in the expression of PGC-1α have been observed in striatum and muscle of HD patients as well as in animal models of the disease. However, it is unknown whether decreased expression of PGC-1α alone is sufficient to lead to the motor phenotype and striatal pathology characteristic of HD. For the first time, we show that young PGC-1α (-/- mice exhibit severe rotarod deficits, decreased rearing behavior, and increased occurrence of tremor in addition to the previously described hindlimb clasping. Motor impairment and striatal vacuolation are apparent in PGC-1α (-/- mice by four weeks of age and do not improve or decline by twelve weeks of age. The behavioral and pathological phenotype of PGC-1α (-/- mice can be completely recapitulated by conditional nervous system deletion of PGC-1α, indicating that peripheral effects are not responsible for the observed abnormalities. Evaluation of the transcriptional profile of PGC-1α (-/- striatal neuron populations and comparison to striatal neuron profiles of R6/2 HD mice revealed that PGC-1α deficiency alone is not sufficient to cause the transcriptional changes observed in this HD mouse model. In contrast to R6/2 HD mice, PGC-1α (-/- mice show increases in the expression of medium spiny neuron (MSN markers with age, suggesting that the observed behavioral and structural abnormalities are not primarily due to MSN loss, the defining pathological feature of HD. These results indicate that PGC-1α is required for the proper development of motor circuitry and transcriptional homeostasis in MSNs and that developmental disruption of PGC-1α leads to long-term alterations in motor functioning.

  9. Mice lacking mPGES-1 are resistant to lithium-induced polyuria.

    Science.gov (United States)

    Jia, Zhanjun; Wang, Haiping; Yang, Tianxin

    2009-12-01

    Cyclooxygenase-2 activity is required for the development of lithium-induced polyuria. However, the involvement of a specific, terminal prostaglandin (PG) isomerase has not been evaluated. The present study was undertaken to assess lithium-induced polyuria in mice deficient in microsomal prostaglandin E synthase-1 (mPGES-1). A 2-wk administration of LiCl (4 mmol.kg(-1).day(-1) ip) in mPGES-1 +/+ mice led to a marked polyuria with hyposmotic urine. This was associated with elevated renal mPGES-1 protein expression and increased urine PGE(2) excretion. In contrast, mPGES-1 -/- mice were largely resistant to lithium-induced polyuria and a urine concentrating defect, accompanied by nearly complete blockade of high urine PGE(2) and cAMP output. Immunoblotting, immunohistochemistry, and quantitative (q) RT-PCR consistently detected a significant decrease in aquaporin-2 (AQP2) protein expression in both the renal cortex and medulla of lithium-treated +/+ mice. This decrease was significantly attenuated in the -/- mice. qRT-PCR detected similar patterns of changes in AQP2 mRNA in the medulla but not in the cortex. Similarly, the total protein abundance of the Na-K-2Cl cotransporter (NKCC2) in the medulla but not in the cortex of the +/+ mice was significantly reduced by lithium treatment. In contrast, the dowregulation of renal medullary NKCC2 expression was significantly attenuated in the -/- mice. We conclude that mPGES-1-derived PGE(2) mediates lithium-induced polyuria likely via inhibition of AQP2 and NKCC2 expression.

  10. Environmental Enrichment Ameliorates Behavioral Impairments Modeling Schizophrenia in Mice Lacking Metabotropic Glutamate Receptor 5.

    Science.gov (United States)

    Burrows, Emma L; McOmish, Caitlin E; Buret, Laetitia S; Van den Buuse, Maarten; Hannan, Anthony J

    2015-07-01

    Schizophrenia arises from a complex interplay between genetic and environmental factors. Abnormalities in glutamatergic signaling have been proposed to underlie the emergence of symptoms, in light of various lines of evidence, including the psychotomimetic effects of NMDA receptor antagonists. Metabotropic glutamate receptor 5 (mGlu5) has also been implicated in the disorder, and has been shown to physically interact with NMDA receptors. To clarify the role of mGlu5-dependent behavioral expression by environmental factors, we assessed mGlu5 knockout (KO) mice after exposure to environmental enrichment (EE) or reared under standard conditions. The mGlu5 KO mice showed reduced prepulse inhibition (PPI), long-term memory deficits, and spontaneous locomotor hyperactivity, which were all attenuated by EE. Examining the cellular impact of genetic and environmental manipulation, we show that EE significantly increased pyramidal cell dendritic branching and BDNF protein levels in the hippocampus of wild-type mice; however, mGlu5 KO mice were resistant to these alterations, suggesting that mGlu5 is critical to these responses. A selective effect of EE on the behavioral response to the NMDA receptor antagonist MK-801 in mGlu5 KO mice was seen. MK-801-induced hyperlocomotion was further potentiated in enriched mGlu5 KO mice and treatment with MK-801 reinstated PPI disruption in EE mGlu5 KO mice only, a response that is absent under standard housing conditions. Together, these results demonstrate an important role for mGlu5 in environmental modulation of schizophrenia-related behavioral impairments. Furthermore, this role of the mGlu5 receptor is mediated by interaction with NMDA receptor function, which may inform development of novel therapeutics.

  11. Mice lacking ANGPTL8 (Betatrophin) manifest disrupted triglyceride metabolism without impaired glucose homeostasis.

    Science.gov (United States)

    Wang, Yan; Quagliarini, Fabiana; Gusarova, Viktoria; Gromada, Jesper; Valenzuela, David M; Cohen, Jonathan C; Hobbs, Helen H

    2013-10-01

    Angiopoietin-like protein (ANGPTL)8 (alternatively called TD26, RIFL, Lipasin, and Betatrophin) is a newly recognized ANGPTL family member that has been implicated in both triglyceride (TG) and glucose metabolism. Hepatic overexpression of ANGPTL8 causes hypertriglyceridemia and increased insulin secretion. Here we examined the effects of inactivating Angptl8 on TG and glucose metabolism in mice. Angptl8 knockout (Angptl8(-/-)) mice gained weight more slowly than wild-type littermates due to a selective reduction in adipose tissue accretion. Plasma levels of TGs of the Angptl8(-/-) mice were similar to wild-type animals in the fasted state but paradoxically decreased after refeeding. The lower TG levels were associated with both a reduction in very low density lipoprotein secretion and an increase in lipoprotein lipase (LPL) activity. Despite the increase in LPL activity, the uptake of very low density lipoprotein-TG is markedly reduced in adipose tissue but preserved in hearts of fed Angptl8(-/-) mice. Taken together, these data indicate that ANGPTL8 plays a key role in the metabolic transition between fasting and refeeding; it is required to direct fatty acids to adipose tissue for storage in the fed state. Finally, glucose and insulin tolerance testing revealed no alterations in glucose homeostasis in mice fed either a chow or high fat diet. Thus, although absence of ANGPTL8 profoundly disrupts TG metabolism, we found no evidence that it is required for maintenance of glucose homeostasis.

  12. Mice lacking melanin-concentrating hormone receptor 1 demonstrate increased heart rate associated with altered autonomic activity.

    Science.gov (United States)

    Astrand, Annika; Bohlooly-Y, Mohammad; Larsdotter, Sara; Mahlapuu, Margit; Andersén, Harriet; Tornell, Jan; Ohlsson, Claes; Snaith, Mike; Morgan, David G A

    2004-10-01

    Melanin-concentrating hormone (MCH) plays an important role in energy balance. The current studies were carried out on a new line of mice lacking the rodent MCH receptor (MCHR1(-/-) mice). These mice confirmed the previously reported lean phenotype characterized by increased energy expenditure and modestly increased caloric intake. Because MCH is expressed in the lateral hypothalamic area, which also has an important role in the regulation of the autonomic nervous system, heart rate and blood pressure were measured by a telemetric method to investigate whether the increased energy expenditure in these mice might be due to altered autonomic nervous system activity. Male MCHR1(-/-) mice demonstrated a significantly increased heart rate [24-h period: wild type 495 +/- 4 vs. MCHR1(-/-) 561 +/- 8 beats/min (P dark phase: wild type 506 +/- 8 vs. MCHR1(-/-) 582 +/- 9 beats/min (P light phase: wild type 484 +/- 13 vs. MCHR1(-/-) 539 +/- 9 beats/min (P vs. MCHR1(-/-) 113 +/- 0.4 mmHg (P > 0.05)]. Locomotor activity and core body temperature were higher in the MCHR1(-/-) mice during the dark phase only and thus temporally dissociated from heart rate differences. On fasting, wild-type animals rapidly downregulated body temperature and heart rate. MCHR1(-/-) mice displayed a distinct delay in the onset of this downregulation. To investigate the mechanism underlying these differences, autonomic blockade experiments were carried out. Administration of the adrenergic antagonist metoprolol completely reversed the tachycardia seen in MCHR1(-/-) mice, suggesting an increased sympathetic tone.

  13. Atypical scrapie prions from sheep and lack of disease in transgenic mice overexpressing human prion protein.

    Science.gov (United States)

    Wadsworth, Jonathan D F; Joiner, Susan; Linehan, Jacqueline M; Balkema-Buschmann, Anne; Spiropoulos, John; Simmons, Marion M; Griffiths, Peter C; Groschup, Martin H; Hope, James; Brandner, Sebastian; Asante, Emmanuel A; Collinge, John

    2013-11-01

    Public and animal health controls to limit human exposure to animal prions are focused on bovine spongiform encephalopathy (BSE), but other prion strains in ruminants may also have zoonotic potential. One example is atypical/Nor98 scrapie, which evaded statutory diagnostic methods worldwide until the early 2000s. To investigate whether sheep infected with scrapie prions could be another source of infection, we inoculated transgenic mice that overexpressed human prion protein with brain tissue from sheep with natural field cases of classical and atypical scrapie, sheep with experimental BSE, and cattle with BSE. We found that these mice were susceptible to BSE prions, but disease did not develop after prolonged postinoculation periods when mice were inoculated with classical or atypical scrapie prions. These data are consistent with the conclusion that prion disease is less likely to develop in humans after exposure to naturally occurring prions of sheep than after exposure to epizootic BSE prions of ruminants.

  14. Defective thrombus formation in mice lacking endogenous factor VII activating protease (FSAP).

    Science.gov (United States)

    Subramaniam, Saravanan; Thielmann, Ina; Morowski, Martina; Pragst, Ingo; Sandset, Per Morten; Nieswandt, Bernhard; Etscheid, Michael; Kanse, Sandip M

    2015-04-01

    Factor VII (FVII) activating protease (FSAP) is a circulating protease with a putative function in blood coagulation and fibrinolysis. Genetic epidemiological studies have implied a role for FSAP in carotid stenosis, stroke and thrombosis. To date, no in vivo evidence is available to support these claims. We have, for the first time, used FSAP-/- mice to define its role in thrombosis and haemostasis in vivo and to characterise the molecular mechanisms involved. FeCl3-induced arterial thrombosis in carotid and mesenteric artery revealed that the occlusion time was significantly increased in FSAP-/- mice (pendogenous FSAP impaired the formation of stable, occlusive thrombi in mice. The underlying in vivo effect of FSAP is more likely to be related to the modulation of TFPI rather than FVIIa.

  15. Testicular development in mice lacking receptors for follicle stimulating hormone and androgen.

    Directory of Open Access Journals (Sweden)

    Peter J O'Shaughnessy

    Full Text Available Post-natal testicular development is dependent on gonadotrophin and androgen stimulation. Follicle stimulating hormone (FSH acts through receptors (FSHR on the Sertoli cell to stimulate spermatogenesis while androgens promote testis growth through receptors (AR on the Sertoli cells, Leydig cells and peritubular myoid cells. In this study we have examined the effects on testis development of ablating FSHRs (FSHRKO mice and/or ARs ubiquitously (ARKO mice or specifically on the Sertoli cells (SCARKO mice. Cell numbers were measured using stereological methods. In ARKO mice Sertoli cell numbers were reduced at all ages from birth until adulthood. FSHR ablation also caused small reductions in Sertoli cell numbers up to day 20 with more marked effects seen in the adult. Germ cell numbers were unaffected by FSHR and/or AR ablation at birth. By day 20 ubiquitous AR or FSHR ablation caused a marked reduction in germ cell numbers with a synergistic effect of losing both receptors (germ cell numbers in FSHRKO.ARKO mice were 3% of control. Germ cell numbers in SCARKO mice were less affected. By adulthood, in contrast, clear synergistic control of germ cell numbers had become established between the actions of FSH and androgen through the Sertoli cells. Leydig cell numbers were normal on day 1 and day 5 in all groups. By day 20 and in adult animals total AR or FSHR ablation significantly reduced Leydig cell numbers but Sertoli cell specific AR ablation had no effect. Results show that, prior to puberty, development of most testicular parameters is more dependent on FSH action than androgen action mediated through the Sertoli cells although androgen action through other cells types is crucial. Post-pubertally, germ cell numbers and spermatogenesis are dependent on FSH and androgen action through the Sertoli cells.

  16. Mice lacking the synaptic adhesion molecule Neph2/Kirrel3 display moderate hyperactivity and defective novel object preference

    Directory of Open Access Journals (Sweden)

    Su Yeon eChoi

    2015-07-01

    Full Text Available Synaptic adhesion molecules regulate diverse aspects of neuronal synapse development, including synapse specificity, formation, and maturation. Neph2, also known as Kirrel3, is an immunoglobulin superfamily adhesion molecule implicated in intellectual disability, neurocognitive delay associated with Jacobsen syndrome, and autism spectrum disorders. We here report mice lacking Neph2 (Neph2–/– mice display moderate hyperactivity in a familiar but not novel environment and novel object recognition deficit with normal performances in Morris water maze spatial learning and memory, contextual fear conditioning and extinction, and pattern separation tests. These mice show normal levels of anxiety-like behaviors, social interaction, and repetitive behaviors. At the synapse level, Neph2–/– dentate gyrus granule cells exhibit unaltered dendritic spine density and spontaneous excitatory synaptic transmission. These results suggest that Neph2 is important for normal locomotor activity and object recognition memory.

  17. Post-exposure vaccination with MP-12 lacking NSs protects mice against lethal Rift Valley fever virus challenge.

    Science.gov (United States)

    Gowen, Brian B; Bailey, Kevin W; Scharton, Dionna; Vest, Zachery; Westover, Jonna B; Skirpstunas, Ramona; Ikegami, Tetsuro

    2013-05-01

    Rift Valley fever virus (RVFV) causes severe disease in humans and livestock. There are currently no approved antivirals or vaccines for the treatment or prevention of RVF disease in humans. A major virulence factor of RVFV is the NSs protein, which inhibits host transcription including the interferon (IFN)-β gene and promotes the degradation of dsRNA-dependent protein kinase, PKR. We analyzed the efficacy of the live-attenuated MP-12 vaccine strain and MP-12 variants that lack the NSs protein as post-exposure vaccinations. Although parental MP-12 failed to elicit a protective effect in mice challenged with wild-type (wt) RVFV by the intranasal route, significant protection was demonstrated by vaccination with MP-12 strains lacking NSs when they were administered at 20-30 min post-exposure. Viremia and virus replication in liver, spleen and brain were also inhibited by post-exposure vaccination with MP-12 lacking NSs. The protective effect was mostly lost when vaccination was delayed 6 or 24 h after intranasal RVFV challenge. When mice were challenged subcutaneously, efficacy of MP-12 lacking NSs was diminished, most likely due to more rapid dissemination of wt RVFV. Our findings suggest that post-exposure vaccination with MP-12 lacking NSs may be developed as a novel post-exposure treatment to prevent RVF. Copyright © 2013 Elsevier B.V. All rights reserved.

  18. Attenuated traumatic axonal injury and improved functional outcome after traumatic brain injury in mice lacking Sarm1.

    Science.gov (United States)

    Henninger, Nils; Bouley, James; Sikoglu, Elif M; An, Jiyan; Moore, Constance M; King, Jean A; Bowser, Robert; Freeman, Marc R; Brown, Robert H

    2016-04-01

    Axonal degeneration is a critical, early event in many acute and chronic neurological disorders. It has been consistently observed after traumatic brain injury, but whether axon degeneration is a driver of traumatic brain injury remains unclear. Molecular pathways underlying the pathology of traumatic brain injury have not been defined, and there is no efficacious treatment for traumatic brain injury. Here we show that mice lacking the mouse Toll receptor adaptor Sarm1 (sterile α/Armadillo/Toll-Interleukin receptor homology domain protein) gene, a key mediator of Wallerian degeneration, demonstrate multiple improved traumatic brain injury-associated phenotypes after injury in a closed-head mild traumatic brain injury model. Sarm1(-/-) mice developed fewer β-amyloid precursor protein aggregates in axons of the corpus callosum after traumatic brain injury as compared to Sarm1(+/+) mice. Furthermore, mice lacking Sarm1 had reduced plasma concentrations of the phophorylated axonal neurofilament subunit H, indicating that axonal integrity is maintained after traumatic brain injury. Strikingly, whereas wild-type mice exibited a number of behavioural deficits after traumatic brain injury, we observed a strong, early preservation of neurological function in Sarm1(-/-) animals. Finally, using in vivo proton magnetic resonance spectroscopy we found tissue signatures consistent with substantially preserved neuronal energy metabolism in Sarm1(-/-) mice compared to controls immediately following traumatic brain injury. Our results indicate that the SARM1-mediated prodegenerative pathway promotes pathogenesis in traumatic brain injury and suggest that anti-SARM1 therapeutics are a viable approach for preserving neurological function after traumatic brain injury. © The Author (2016). Published by Oxford University Press on behalf of the Guarantors of Brain. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  19. Dwarfism and early death in mice lacking C-type natriuretic peptide

    Science.gov (United States)

    Chusho, Hideki; Tamura, Naohisa; Ogawa, Yoshihiro; Yasoda, Akihiro; Suda, Michio; Miyazawa, Takashi; Nakamura, Kenji; Nakao, Kazuki; Kurihara, Tatsuya; Komatsu, Yasato; Itoh, Hiroshi; Tanaka, Kiyoshi; Saito, Yoshihiko; Katsuki, Motoya; Nakao, Kazuwa

    2001-01-01

    Longitudinal bone growth is determined by endochondral ossification that occurs as chondrocytes in the cartilaginous growth plate undergo proliferation, hypertrophy, cell death, and osteoblastic replacement. The natriuretic peptide family consists of three structurally related endogenous ligands, atrial, brain, and C-type natriuretic peptides (ANP, BNP, and CNP), and is thought to be involved in a variety of homeostatic processes. To investigate the physiological significance of CNP in vivo, we generated mice with targeted disruption of CNP (Nppc−/− mice). The Nppc−/− mice show severe dwarfism as a result of impaired endochondral ossification. They are all viable perinatally, but less than half can survive during postnatal development. The skeletal phenotypes are histologically similar to those seen in patients with achondroplasia, the most common genetic form of human dwarfism. Targeted expression of CNP in the growth plate chondrocytes can rescue the skeletal defect of Nppc−/− mice and allow their prolonged survival. This study demonstrates that CNP acts locally as a positive regulator of endochondral ossification in vivo and suggests its pathophysiological and therapeutic implication in some forms of skeletal dysplasia. PMID:11259675

  20. Base excision repair deficient mice lacking the Aag alkyladenine DNA glycosylase.

    NARCIS (Netherlands)

    B.P. Engelward (Bevin); G. Weeda (Geert); M.D. Wyatt; J.L.M. Broekhof (Jose'); J. de Wit (Jan); I. Donker (Ingrid); J.M. Allan (James); B. Gold (Bert); J.H.J. Hoeijmakers (Jan); L.D. Samson (Leona)

    1997-01-01

    textabstract3-methyladenine (3MeA) DNA glycosylases remove 3MeAs from alkylated DNA to initiate the base excision repair pathway. Here we report the generation of mice deficient in the 3MeA DNA glycosylase encoded by the Aag (Mpg) gene. Alkyladenine DNA glycosylase turns out to be the major DNA

  1. Lack of genotoxic potential of pesticides, spinosad, imidacloprid and neem oil in mice (Mus musculus).

    Science.gov (United States)

    Saxena, Ankita; Kesari, V P

    2016-03-01

    Pesticides, spinosad, imidacloprid and neem oil are widely used both in residential and agricultural environments because of its broad spectrum insecticidal activity and effectiveness. The present study was undertaken to estimate genotoxicity of formulations of some pesticides in mice. Three pesticides of diverse group studied were spinosad (45% w/v), imidacloprid (17.8%, w/v) and neem oil. Animals were exposed 37, 4.5 and 50 mg kg⁻¹ b.wt. for spinosad, imidacloprid and neem oil, respectively, through oral gavage for 5 consecutive days. A vehicle control group and one positive control (cyclophosphamide; 20 mg kg⁻¹ b. wt.) were also selected. The results showed that cyclophosphamide produced 1.12% micronuclei in mice, as against 0.18 in vehicle control, 0.30 in spinosad, 0.28 in imidacloprid and 0.22% in neem oil, respectively. The gross percentage of chromosomal aberration in mice were 28.5% in cyclophosphamide against 6.5% in vehicle control, 8.0% in spinosad, 9.5% in imidacloprid and 7.0% in neem oil, respectively. The overall findings of the present study revealed that all the three pesticide formulations, imidacloprid, spinosad and neem oil at tested dose did not show any genotoxic effect in mice.

  2. Multiple alterations of platelet functions dominated by increased secretion in mice lacking Cdc42 in platelets

    DEFF Research Database (Denmark)

    Pleines, Irina; Eckly, Anita; Elvers, Margitta

    2010-01-01

    formation and exocytosis in various cell types, but its exact function in platelets is not established. Here, we show that the megakaryocyte/platelet-specific loss of Cdc42 leads to mild thrombocytopenia and a small increase in platelet size in mice. Unexpectedly, Cdc42-deficient platelets were able to form...

  3. Mice lacking desmocollin 1 show epidermal fragility accompanied by barrier defects and abnormal differentiation

    DEFF Research Database (Denmark)

    Chidgey, M; Brakebusch, C; Gustafsson, E

    2001-01-01

    epidermis because environmental insults are more stringent and wound healing is less rapid than in neonatal mice. This dermatitis is accompanied by localized hair loss associated with formation of utriculi and dermal cysts, denoting hair follicle degeneration. Possible resemblance of the lesions to human...

  4. Abnormal motor phenotype at adult stages in mice lacking type 2 deiodinase.

    Directory of Open Access Journals (Sweden)

    Soledad Bárez-López

    Full Text Available BACKGROUND: Thyroid hormones have a key role in both the developing and adult central nervous system and skeletal muscle. The thyroid gland produces mainly thyroxine (T4 but the intracellular concentrations of 3,5,3'-triiodothyronine (T3; the transcriptionally active hormone in the central nervous system and skeletal muscle are modulated by the activity of type 2 deiodinase (D2. To date no neurological syndrome has been associated with mutations in the DIO2 gene and previous studies in young and juvenile D2-knockout mice (D2KO did not find gross neurological alterations, possibly due to compensatory mechanisms. AIM: This study aims to analyze the motor phenotype of 3-and-6-month-old D2KO mice to evaluate the role of D2 on the motor system at adult stages in which compensatory mechanisms could have failed. RESULTS: Motor abilities were explored by validated tests. In the footprint test, D2KO showed an altered global gait pattern (mice walked slower, with shorter strides and with a hindlimb wider base of support than wild-type mice. No differences were detected in the balance beam test. However, a reduced latency to fall was found in the rotarod, coat-hanger and four limb hanging wire tests indicating impairment on coordination and prehensile reflex and a reduction of muscle strength. In histological analyses of cerebellum and skeletal muscle, D2KO mice did not present gross structural abnormalities. Thyroid hormones levels and deiodinases activities were also determined. In D2KO mice, despite euthyroid T3 and high T4 plasma levels, T3 levels were significantly reduced in cerebral cortex (48% reduction and skeletal muscle (33% reduction, but not in the cerebellum where other deiodinase (type 1 is expressed. CONCLUSIONS: The motor alterations observed in D2KO mice indicate an important role for D2 in T3 availability to maintain motor function and muscle strength. Our results suggest a possible implication of D2 in motor disorders.

  5. Communication impairments in mice lacking Shank1: reduced levels of ultrasonic vocalizations and scent marking behavior.

    Directory of Open Access Journals (Sweden)

    Markus Wöhr

    Full Text Available Autism is a neurodevelopmental disorder with a strong genetic component. Core symptoms are abnormal reciprocal social interactions, qualitative impairments in communication, and repetitive and stereotyped patterns of behavior with restricted interests. Candidate genes for autism include the SHANK gene family, as mutations in SHANK2 and SHANK3 have been detected in several autistic individuals. SHANK genes code for a family of scaffolding proteins located in the postsynaptic density of excitatory synapses. To test the hypothesis that a mutation in SHANK1 contributes to the symptoms of autism, we evaluated Shank1(-/- null mutant mice for behavioral phenotypes with relevance to autism, focusing on social communication. Ultrasonic vocalizations and the deposition of scent marks appear to be two major modes of mouse communication. Our findings revealed evidence for low levels of ultrasonic vocalizations and scent marks in Shank1(-/- mice as compared to wildtype Shank1(+/+ littermate controls. Shank1(-/- pups emitted fewer vocalizations than Shank1(+/+ pups when isolated from mother and littermates. In adulthood, genotype affected scent marking behavior in the presence of female urinary pheromones. Adult Shank1(-/- males deposited fewer scent marks in proximity to female urine than Shank1(+/+ males. Call emission in response to female urinary pheromones also differed between genotypes. Shank1(+/+ mice changed their calling pattern dependent on previous female interactions, while Shank1(-/- mice were unaffected, indicating a failure of Shank1(-/- males to learn from a social experience. The reduced levels of ultrasonic vocalizations and scent marking behavior in Shank1(-/- mice are consistent with a phenotype relevant to social communication deficits in autism.

  6. Communication Impairments in Mice Lacking Shank1: Reduced Levels of Ultrasonic Vocalizations and Scent Marking Behavior

    Science.gov (United States)

    Wöhr, Markus; Roullet, Florence I.; Hung, Albert Y.; Sheng, Morgan; Crawley, Jacqueline N.

    2011-01-01

    Autism is a neurodevelopmental disorder with a strong genetic component. Core symptoms are abnormal reciprocal social interactions, qualitative impairments in communication, and repetitive and stereotyped patterns of behavior with restricted interests. Candidate genes for autism include the SHANK gene family, as mutations in SHANK2 and SHANK3 have been detected in several autistic individuals. SHANK genes code for a family of scaffolding proteins located in the postsynaptic density of excitatory synapses. To test the hypothesis that a mutation in SHANK1 contributes to the symptoms of autism, we evaluated Shank1 −/− null mutant mice for behavioral phenotypes with relevance to autism, focusing on social communication. Ultrasonic vocalizations and the deposition of scent marks appear to be two major modes of mouse communication. Our findings revealed evidence for low levels of ultrasonic vocalizations and scent marks in Shank1 −/− mice as compared to wildtype Shank1 +/+ littermate controls. Shank1 −/− pups emitted fewer vocalizations than Shank1+/+ pups when isolated from mother and littermates. In adulthood, genotype affected scent marking behavior in the presence of female urinary pheromones. Adult Shank1 −/− males deposited fewer scent marks in proximity to female urine than Shank1+/+ males. Call emission in response to female urinary pheromones also differed between genotypes. Shank1+/+ mice changed their calling pattern dependent on previous female interactions, while Shank1 −/− mice were unaffected, indicating a failure of Shank1 −/− males to learn from a social experience. The reduced levels of ultrasonic vocalizations and scent marking behavior in Shank1 −/− mice are consistent with a phenotype relevant to social communication deficits in autism. PMID:21695253

  7. Mice lacking the kf-1 gene exhibit increased anxiety- but not despair-like behavior

    Directory of Open Access Journals (Sweden)

    Atsushi Tsujimura

    2008-09-01

    Full Text Available KF-1 was originally identified as a protein encoded by human gene with increased expression in the cerebral cortex of a patient with Alzheimer’s disease. In mouse brain, kf-1 mRNA is detected predominantly in the hippocampus and cerebellum, and kf-1 gene expression is elevated also in the frontal cortex of rats after chronic antidepressant treatments. KF-1 mediates E2-dependent ubiquitination and may modulate cellular protein levels as an E3 ubiquitin ligase, though its target proteins are not yet identified. To elucidate the role of kf-1 in the central nervous system, we generated kf-1 knockout mice by gene targeting, using Cre-lox recombination. The resulting kf-1−/− mice were normal and healthy in appearance. Behavioral analyses revealed that kf-1−/− mice showed significantly increased anxiety-like behavior compared with kf-1+/+ littermates in the light/dark transition and elevated plus maze tests; however, no significant differences were observed in exploratory locomotion using the open field test or in behavioral despair using the forced swim and tail suspension tests. These observations suggest that KF-1 suppresses selectively anxiety under physiological conditions probably through modulating protein levels of its unknown target(s. Interestingly, kf-1−/− mice exhibited significantly increased prepulse inhibition, which is usually reduced in human schizophrenic patients. Thus, the kf-1−/− mice provide a novel animal model for elucidating molecular mechanisms of psychiatric diseases such as anxiety/depression, and may be useful for screening novel anxiolytic/antidepressant compounds.

  8. Lack of adrenomedullin results in microbiota changes and aggravates azoxymethane and dextran sulfate sodium-induced colitis in mice

    Directory of Open Access Journals (Sweden)

    Sonia Martinez-Herrero

    2016-11-01

    Full Text Available The link between intestinal inflammation, microbiota, and colorectal cancer (CRC is intriguing and the potential underlying mechanisms remain unknown. Here we evaluate the influence of adrenomedullin (AM in microbiota composition and its impact on colitis with an inducible knockout (KO mouse model for AM. Microbiota composition was analyzed in KO and wild type (WT mice by pyrosequencing. Colitis was induced in mice by administration of azoxymethane (AOM followed by dextran sulfate sodium (DSS in the drinking water. Colitis was evaluated using a clinical symptoms index, histopathological analyses, and qRT-PCR. Abrogation of the adm gene in the whole body was confirmed by PCR and qRT-PCR. KO mice exhibit significant changes in colonic microbiota: higher proportion of δ-Proteobacteria class; of Coriobacteriales order; and of other families and genera was observed in KO feces. Meanwhile these mice had a lower proportion of beneficial bacteria, such as Lactobacillus gasseri and Bifidobacterium choerinum. TLR4 gene expression was higher (p<0.05 in KO animals. AM deficient mice treated with DSS exhibited a significantly worse colitis with profound weight loss, severe diarrhea, rectal bleeding, colonic inflammation, edema, infiltration, crypt destruction, and higher levels of pro-inflammatory cytokines. No changes were observed in the expression levels of adhesion molecules. In conclusion, we have shown that lack of AM leads to changes in gut microbiota population and in a worsening of colitis conditions, suggesting that endogenous AM is a protective mediator in this pathology.

  9. Obesity resistance and multiple mechanisms of triglyceride synthesis in mice lacking Dgat.

    Science.gov (United States)

    Smith, S J; Cases, S; Jensen, D R; Chen, H C; Sande, E; Tow, B; Sanan, D A; Raber, J; Eckel, R H; Farese, R V

    2000-05-01

    Triglycerides (or triacylglycerols) represent the major form of stored energy in eukaryotes. Triglyceride synthesis has been assumed to occur primarily through acyl CoA:diacylglycerol transferase (Dgat), a microsomal enzyme that catalyses the final and only committed step in the glycerol phosphate pathway. Therefore, Dgat has been considered necessary for adipose tissue formation and essential for survival. Here we show that Dgat-deficient (Dgat-/-) mice are viable and can still synthesize triglycerides. Moreover, these mice are lean and resistant to diet-induced obesity. The obesity resistance involves increased energy expenditure and increased activity. Dgat deficiency also alters triglyceride metabolism in other tissues, including the mammary gland, where lactation is defective in Dgat-/- females. Our findings indicate that multiple mechanisms exist for triglyceride synthesis and suggest that the selective inhibition of Dgat-mediated triglyceride synthesis may be useful for treating obesity.

  10. Lack of carcinogenicity of tragacanth gum in B6C3F1 mice.

    Science.gov (United States)

    Hagiwara, A; Boonyaphiphat, P; Kawabe, M; Naito, H; Shirai, T; Ito, N

    1992-08-01

    Tragacanth gum was administered at dietary levels of 0 (control), 1.25 and 5.0% to groups of 50 male and 50 female B6C3F1 mice for 96 wk after which all animals were maintained on a basal diet without tragacanth gum for a further 10 wk. Mean body weights of females in the 5.0% and 1.25% groups were lower than those of the controls after 11 and 16 wk, respectively. However, there were no treatment-related clinical signs or adverse effects on survival rate, urinalysis, haematology, blood biochemistry and organ weight. While detailed histopathology revealed the development of squamous cell hyperplasias, papillomas and one carcinoma in the forestomach, there was no significant treatment-related increase in the incidence of any preneoplastic or neoplastic lesion. Thus, under the experimental conditions used, tragacanth gum was not carcinogenic in B6C3F1 mice of either sex.

  11. The transient outward current in mice lacking the potassium channel gene Kv1.4

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    London, Barry; Wang, Dao W; Hill, Joseph A; Bennett, Paul B

    1998-01-01

    The transient outward current (Ito) plays a prominent role in the repolarization phase of the cardiac action potential. Several K+ channel genes, including Kv1.4, are expressed in the heart, produce rapidly inactivating currents when heterologously expressed, and may be the molecular basis of Ito.We engineered mice homozygous for a targeted disruption of the K+ channel gene Kv1.4 and compared Ito in wild-type (Kv1.4+/+), heterozygous (Kv1.4+/-) and homozygous ‘knockout’ (Kv1.4−/−) mice. Kv1.4 RNA was truncated in Kv1.4−/− mice and protein expression was absent.Adult myocytes isolated from Kv1.4+/+, Kv1.4+/− and Kv1.4−/− mice had large rapidly inactivating outward currents. The peak current densities at 60 mV (normalized by cellular capacitance, in pA pF−1; means ± s.e.m.) were 53.8 ± 5.3, 45.3 ± 2.2 and 44.4 ± 2.8 in cells from Kv1.4+/+, Kv1.4+/− and Kv1.4−/− mice, respectively (P mice.The voltage dependence and time course of inactivation were not changed by targeted disruption of Kv1.4. The mean best-fitting V½ (membrane potential at 50 % inactivation) values for myocytes from Kv1.4 +/+, Kv1.4+/− and Kv1.4−/− mice were -53.5 ± 3.7, -51.1 ± 2.6 and -54.2 ± 2.4 mV, respectively. The slope factors (k) were -10.1 ± 1.4, -8.8 ± 1.4 and -9.5 ± 1.2 mV, respectively. The fast time constants for development of inactivation at -30 mV were 27.8 ± 2.2, 26.2 ± 5.1 and 19.6 ± 2.1 ms in Kv1.4+/+, Kv1.4+/− and Kv1.4−/− myocytes, respectively. At +30 mV, they were 35.5 ± 2.6, 30.0 ± 2.1 and 28.7 ± 1.6 ms, respectively. The time constants for the rapid phase of recovery from inactivation at -80 mV were 32.5 ± 8.2, 23.3 ± 1.8 and 39.0 ± 3.7 ms, respectively.Nearly the entire inactivating component as well as more than 60 % of the steady-state outward current was eliminated by 1 mm 4-aminopyridine in Kv1.4+/+, Kv1.4+/− and Kv1.4−/− myocytes.Western blot analysis of heart membrane extracts showed no significant

  12. Autism-like socio-communicative deficits and stereotypies in mice lacking heparan sulfate.

    Science.gov (United States)

    Irie, Fumitoshi; Badie-Mahdavi, Hedieh; Yamaguchi, Yu

    2012-03-27

    Heparan sulfate regulates diverse cell-surface signaling events, and its roles in the development of the nervous system recently have been increasingly uncovered by studies using genetic models carrying mutations of genes encoding enzymes for its synthesis. On the other hand, the role of heparan sulfate in the physiological function of the adult brain has been poorly characterized, despite several pieces of evidence suggesting its role in the regulation of synaptic function. To address this issue, we eliminated heparan sulfate from postnatal neurons by conditionally inactivating Ext1, the gene encoding an enzyme essential for heparan sulfate synthesis. Resultant conditional mutant mice show no detectable morphological defects in the cytoarchitecture of the brain. Remarkably, these mutant mice recapitulate almost the full range of autistic symptoms, including impairments in social interaction, expression of stereotyped, repetitive behavior, and impairments in ultrasonic vocalization, as well as some associated features. Mapping of neuronal activation by c-Fos immunohistochemistry demonstrates that neuronal activation in response to social stimulation is attenuated in the amygdala in these mice. Electrophysiology in amygdala pyramidal neurons shows an attenuation of excitatory synaptic transmission, presumably because of the reduction in the level of synaptically localized AMPA-type glutamate receptors. Our results demonstrate that heparan sulfate is critical for normal functioning of glutamatergic synapses and that its deficiency mediates socio-communicative deficits and stereotypies characteristic for autism.

  13. Mice lacking cystathionine beta synthase have lung fibrosis and air space enlargement.

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    Hamelet, Julien; Maurin, Nicole; Fulchiron, Romain; Delabar, Jean-Maurice; Janel, Nathalie

    2007-10-01

    Cystathionine beta synthase (CBS) is a crucial regulator of plasma concentrations of homocysteine. Severe hyperhomocysteinemia due to CBS deficiency confers diverse clinical manifestations, notably pulmonary thrombotic disease. However, the association between hyperhomocysteinemia and chronic obstructive pulmonary disease is not well understood. To investigate the role of hyperhomocysteinemia in lung injury and pulmonary fibrosis, we analyzed the lung of CBS-deficient mice, a murine model of severe hyperhomocysteinemia. The degree of lung injury was assessed by histologic examination. Analysis of profibrogenic factors was performed by real-time quantitative reverse transcription-polymerase chain reaction. CBS-deficient mice develop fibrosis and air space enlargement in the lung, concomitant with an enhanced expression of heme oxygenase-1, pro(alpha)1 collagen type I, transforming growth factor-beta1 and alpha-smooth muscle actin. However, lung fibrosis was found in the absence of increased inflammatory cell infiltrates as determined by histology, without changes in gene expression of proinflammatory cytokines TNFalpha and interleukin 6. The increased expression of alpha-smooth muscle actin and transforming growth factor-beta1 emphasizes the role of myofibroblasts differentiation in case of lung fibrosis due to CBS deficiency in mice.

  14. Mice Lacking Pannexin 1 Release ATP and Respond Normally to All Taste Qualities.

    Science.gov (United States)

    Vandenbeuch, Aurelie; Anderson, Catherine B; Kinnamon, Sue C

    2015-09-01

    Adenosine triphosphate (ATP) is required for the transmission of all taste qualities from taste cells to afferent nerve fibers. ATP is released from Type II taste cells by a nonvesicular mechanism and activates purinergic receptors containing P2X2 and P2X3 on nerve fibers. Several ATP release channels are expressed in taste cells including CALHM1, Pannexin 1, Connexin 30, and Connexin 43, but whether all are involved in ATP release is not clear. We have used a global Pannexin 1 knock out (Panx1 KO) mouse in a series of in vitro and in vivo experiments. Our results confirm that Panx1 channels are absent in taste buds of the knockout mice and that other known ATP release channels are not upregulated. Using a luciferin/luciferase assay, we show that circumvallate taste buds from Panx1 KO mice normally release ATP upon taste stimulation compared with wild type (WT) mice. Gustatory nerve recordings in response to various tastants applied to the tongue and brief-access behavioral testing with SC45647 also show no difference between Panx1 KO and WT. These results confirm that Panx1 is not required for the taste evoked release of ATP or for neural and behavioral responses to taste stimuli. © The Author 2015. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  15. Cytochrome P450-2E1 is involved in aging-related kidney damage in mice through increased nitroxidative stress.

    Science.gov (United States)

    Abdelmegeed, Mohamed A; Choi, Youngshim; Ha, Seung-Kwoon; Song, Byoung-Joon

    2017-11-01

    The aim of this study was to investigate the role of cytochrome P450-2E1 (CYP2E1) in aging-dependent kidney damage since it is poorly understood. Young (7 weeks) and aged female (16-17 months old) wild-type (WT) and Cyp2e1-null mice were used. Kidney histology showed that aged WT mice exhibited typical signs of kidney aging such as cell vacuolation, inflammatory cell infiltration, cellular apoptosis, glomerulonephropathy, and fibrosis, along with significantly elevated levels of renal TNF-α and serum creatinine than all other groups. Furthermore, the highest levels of renal hydrogen peroxide, protein carbonylation and nitration were observed in aged WT mice. These increases in the aged WT mice were accompanied by increased levels of iNOS and mitochondrial nitroxidative stress through altered amounts and activities of the mitochondrial complex proteins and significantly reduced levels of the antioxidant glutathione (GSH). In contrast, the aged Cyp2e1-null mice exhibited significantly higher antioxidant capacity with elevated heme oxygenase-1 and catalase activities compared to all other groups, while maintaining normal GSH levels with significantly less mitochondrial nitroxidative stress compared to the aged WT mice. Thus, CYP2E1 is important in causing aging-related kidney damage most likely through increasing nitroxidative stress and that CYP2E1 could be a potential target in preventing aging-related kidney diseases. Published by Elsevier Ltd.

  16. Cytochrome P450 1A1 (CYP1A1) protects against nonalcoholic fatty liver disease caused by Western diet containing benzo[a]pyrene in mice.

    Science.gov (United States)

    Uno, Shigeyuki; Nebert, Daniel W; Makishima, Makoto

    2018-03-01

    The Western diet contributes to nonalcoholic fatty liver disease (NAFLD) pathogenesis. Benzo[a]pyrene (BaP), a prototypical environmental pollutant produced by combustion processes, is present in charcoal-grilled meat. Cytochrome P450 1A1 (CYP1A1) metabolizes BaP, resulting in either detoxication or metabolic activation in a context-dependent manner. To elucidate a role of CYP1A1-BaP in NAFLD pathogenesis, we compared the effects of a Western diet, with or without oral BaP treatment, on the development of NAFLD in Cyp1a1(-/-) mice versus wild-type mice. A Western diet plus BaP induced lipid-droplet accumulation in liver of Cyp1a1(-/-) mice, but not wild-type mice. The hepatic steatosis observed in Cyp1a1(-/-) mice was associated with increased cholesterol, triglyceride and bile acid levels. Cyp1a1(-/-) mice fed Western diet plus BaP had changes in expression of genes involved in bile acid and lipid metabolism, and showed no increase in Cyp1a2 expression but did exhibit enhanced Cyp1b1 mRNA expression, as well as hepatic inflammation. Enhanced BaP metabolic activation, oxidative stress and inflammation may exacerbate metabolic dysfunction in liver of Cyp1a1(-/-) mice. Thus, Western diet plus BaP induces NAFLD and hepatic inflammation in Cyp1a1(-/-) mice in comparison to wild-type mice, indicating a protective role of CYP1A1 against NAFLD pathogenesis. Copyright © 2018 Elsevier Ltd. All rights reserved.

  17. Alterations in gene expression in mutant amyloid precursor protein transgenic mice lacking Niemann-Pick type C1 protein.

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    Mahua Maulik

    Full Text Available Niemann-Pick type C (NPC disease, a rare autosomal recessive disorder caused mostly by mutation in NPC1 gene, is pathologically characterized by the accumulation of free cholesterol in brain and other tissues. This is accompanied by gliosis and loss of neurons in selected brain regions, including the cerebellum. Recent studies have shown that NPC disease exhibits intriguing parallels with Alzheimer's disease, including the presence of neurofibrillary tangles and increased levels of amyloid precursor protein (APP-derived β-amyloid (Aβ peptides in vulnerable brain neurons. To evaluate the role of Aβ in NPC disease, we determined the gene expression profile in selected brain regions of our recently developed bigenic ANPC mice, generated by crossing APP transgenic (Tg mice with heterozygous Npc1-deficient mice. The ANPC mice exhibited exacerbated neuronal and glial pathology compared to other genotypes [i.e., APP-Tg, double heterozygous (Dhet, Npc1-null and wild-type mice]. Analysis of expression profiles of 86 selected genes using real-time RT-PCR arrays showed a wide-spectrum of alterations in the four genotypes compared to wild-type controls. The changes observed in APP-Tg and Dhet mice are limited to only few genes involved mostly in the regulation of cholesterol metabolism, whereas Npc1-null and ANPC mice showed alterations in the expression profiles of a number of genes regulating cholesterol homeostasis, APP metabolism, vesicular trafficking and cell death mechanism in both hippocampus and cerebellum compared to wild-type mice. Intriguingly, ANPC and Npc1-null mice, with some exceptions, exhibited similar changes, although more genes were differentially expressed in the affected cerebellum than the relatively spared hippocampus. The altered gene profiles were found to match with the corresponding protein levels. These results suggest that lack of Npc1 protein can alter the expression profile of selected transcripts as well as proteins, and

  18. Impaired neuronal maturation of hippocampal neural progenitor cells in mice lacking CRAF.

    Science.gov (United States)

    Pfeiffer, Verena; Götz, Rudolf; Camarero, Guadelupe; Heinsen, Helmut; Blum, Robert; Rapp, Ulf Rüdiger

    2018-01-01

    RAF kinases are major constituents of the mitogen activated signaling pathway, regulating cell proliferation, differentiation and cell survival of many cell types, including neurons. In mammals, the family of RAF proteins consists of three members, ARAF, BRAF, and CRAF. Ablation of CRAF kinase in inbred mouse strains causes major developmental defects during fetal growth and embryonic or perinatal lethality. Heterozygous germline mutations in CRAF result in Noonan syndrome, which is characterized by neurocognitive impairment that may involve hippocampal physiology. The role of CRAF signaling during hippocampal development and generation of new postnatal hippocampal granule neurons has not been examined and may provide novel insight into the cause of hippocampal dysfunction in Noonan syndrome. In this study, by crossing CRAF-deficiency to CD-1 outbred mice, a CRAF mouse model was established which enabled us to investigate the interplay of neural progenitor proliferation and postmitotic differentiation during adult neurogenesis in the hippocampus. Albeit the general morphology of the hippocampus was unchanged, CRAF-deficient mice displayed smaller granule cell layer (GCL) volume at postnatal day 30 (P30). In CRAF-deficient mice a substantial number of abnormal, chromophilic, fast dividing cells were found in the subgranular zone (SGZ) and hilus of the dentate gyrus (DG), indicating that CRAF signaling contributes to hippocampal neural progenitor proliferation. CRAF-deficient neural progenitor cells showed an increased cell death rate and reduced neuronal maturation. These results indicate that CRAF function affects postmitotic neural cell differentiation and points to a critical role of CRAF-dependent growth factor signaling pathway in the postmitotic development of adult-born neurons.

  19. Pancreatic ductal adenocarcinoma mice lacking mucin 1 have a profound defect in tumor growth and metastasis.

    Science.gov (United States)

    Besmer, Dahlia M; Curry, Jennifer M; Roy, Lopamudra D; Tinder, Teresa L; Sahraei, Mahnaz; Schettini, Jorge; Hwang, Sun-Il; Lee, Yong Y; Gendler, Sandra J; Mukherjee, Pinku

    2011-07-01

    MUC1 is overexpressed and aberrantly glycosylated in more than 60% of pancreatic ductal adenocarcinomas. The functional role of MUC1 in pancreatic cancer has yet to be fully elucidated due to a dearth of appropriate models. In this study, we have generated mouse models that spontaneously develop pancreatic ductal adenocarcinoma (KC), which are either Muc1-null (KCKO) or express human MUC1 (KCM). We show that KCKO mice have significantly slower tumor progression and rates of secondary metastasis, compared with both KC and KCM. Cell lines derived from KCKO tumors have significantly less tumorigenic capacity compared with cells from KCM tumors. Therefore, mice with KCKO tumors had a significant survival benefit compared with mice with KCM tumors. In vitro, KCKO cells have reduced proliferation and invasion and failed to respond to epidermal growth factor, platelet-derived growth factor, or matrix metalloproteinase 9. Further, significantly less KCKO cells entered the G(2)-M phase of the cell cycle compared with the KCM cells. Proteomics and Western blotting analysis revealed a complete loss of cdc-25c expression, phosphorylation of mitogen-activated protein kinase (MAPK), as well as a significant decrease in nestin and tubulin-α2 chain expression in KCKO cells. Treatment with a MEK1/2 inhibitor, U0126, abrogated the enhanced proliferation of the KCM cells but had minimal effect on KCKO cells, suggesting that MUC1 is necessary for MAPK activity and oncogenic signaling. This is the first study to utilize a Muc1-null PDA mouse to fully elucidate the oncogenic role of MUC1, both in vivo and in vitro. ©2011 AACR

  20. Generation of mice lacking DUF1220 protein domains: effects on fecundity and hyperactivity

    Science.gov (United States)

    Keeney, JG; O’Bleness, MS; Anderson, N; Davis, JM; Arevalo, N; Busquet, N; Chick, W; Rozman, J; Hölter, SM; Garrett, L; Horsch, M; Beckers, J; Wurst, W; Klingenspor, M; Restrepo, D

    2014-01-01

    Sequences encoding DUF1220 protein domains show the most extreme human lineage-specific copy number increase of any coding region in the genome and have been linked to human brain evolution. In addition, DUF1220 copy number (dosage) has been implicated in influencing brain size within the human species, both in normal populations and in individuals associated with brain size pathologies (1q21-associated microcephaly and macrocephaly). More recently, increasing dosage of a subtype of DUF1220 has been linked with increasing severity of the primary symptoms of autism. Despite these intriguing associations, a function for these domains has not been described. As a first step in addressing this question we have developed the first transgenic model of DUF1220 function by removing the single DUF1220 domain (the ancestral form) encoded in the mouse genome. In a hypothesis generating exercise, these mice were evaluated by 197 different phenotype measurements. While resulting DUF1220-minus (KO) mice show no obvious anatomical peculiarities, they exhibit a significantly reduced fecundity (χ2= 19.1, df = 2, p = 7.0 × 10−5). Further extensive phenotypic analyses suggest hyperactivity (p < 0.05) of DUF1220 mice and changes in gene expression levels of brain associated with distinct neurological functions and disease. Other changes that met statistical significance include an increase in plasma glucose concentration (as measured by Area Under the Curve, AUC 0-30 and AUC 30-120) in male mutants, fasting glucose levels, reduce sodium levels in male mutants, increased levels of the liver functional indicator ALAT/GPT in males, levels of alkaline phosphatase (also an indicator of liver function), mean R and SR amplitude by electrocardiography, elevated IgG3 levels, a reduced ratio of CD4:CD8 cells, and a reduced frequency of T cells; though it should be noted that many of these differences are quite small and require further examination. The linking of DUF1220 loss to a

  1. Generation of mice lacking DUF1220 protein domains: effects on fecundity and hyperactivity.

    Science.gov (United States)

    Keeney, J G; O'Bleness, M S; Anderson, N; Davis, J M; Arevalo, N; Busquet, N; Chick, W; Rozman, J; Hölter, S M; Garrett, L; Horsch, M; Beckers, J; Wurst, W; Klingenspor, M; Restrepo, D; de Angelis, M Hrabě; Sikela, J M

    2015-02-01

    Sequences encoding DUF1220 protein domains show the most extreme human lineage-specific copy number increase of any coding region in the genome and have been linked to human brain evolution. In addition, DUF1220 copy number (dosage) has been implicated in influencing brain size within the human species, both in normal populations and in individuals associated with brain size pathologies (1q21-associated microcephaly and macrocephaly). More recently, increasing dosage of a subtype of DUF1220 has been linked with increasing severity of the primary symptoms of autism. Despite these intriguing associations, a function for these domains has not been described. As a first step in addressing this question, we have developed the first transgenic model of DUF1220 function by removing the single DUF1220 domain (the ancestral form) encoded in the mouse genome. In a hypothesis generating exercise, these mice were evaluated by 197 different phenotype measurements. While resulting DUF1220-minus (KO) mice show no obvious anatomical peculiarities, they exhibit a significantly reduced fecundity (χ(2) = 19.1, df = 2, p = 7.0 × 10(-5)). Further extensive phenotypic analyses suggest hyperactivity (p < 0.05) of DUF1220 mice and changes in gene expression levels of brain associated with distinct neurological functions and disease. Other changes that met statistical significance include an increase in plasma glucose concentration (as measured by area under the curve, AUC 0-30 and AUC 30-120) in male mutants, fasting glucose levels, reduce sodium levels in male mutants, increased levels of the liver functional indicator ALAT/GPT in males, levels of alkaline phosphatase (also an indicator of liver function), mean R and SR amplitude by electrocardiography, elevated IgG3 levels, a reduced ratio of CD4:CD8 cells, and a reduced frequency of T cells; though it should be noted that many of these differences are quite small and require further examination. The linking of DUF1220 loss to a

  2. Lack of tryptophan hydroxylase-1 in mice results in gait abnormalities.

    Science.gov (United States)

    Suidan, Georgette L; Duerschmied, Daniel; Dillon, Gregory M; Vanderhorst, Veronique; Hampton, Thomas G; Wong, Siu Ling; Voorhees, Jaymie R; Wagner, Denisa D

    2013-01-01

    The role of peripheral serotonin in nervous system development is poorly understood. Tryptophan hydroxylase-1 (TPH1) is expressed by non-neuronal cells including enterochromaffin cells of the gut, mast cells and the pineal gland and is the rate-limiting enzyme involved in the biosynthesis of peripheral serotonin. Serotonin released into circulation is taken up by platelets via the serotonin transporter and stored in dense granules. It has been previously reported that mouse embryos removed from Tph1-deficient mothers present abnormal nervous system morphology. The goal of this study was to assess whether Tph1-deficiency results in behavioral abnormalities. We did not find any differences between Tph1-deficient and wild-type mice in general motor behavior as tested by rotarod, grip-strength test, open field and beam walk. However, here we report that Tph1 (-/-) mice display altered gait dynamics and deficits in rearing behavior compared to wild-type (WT) suggesting that tryptophan hydroxylase-1 expression has an impact on the nervous system.

  3. Mice lacking natural killer T cells are more susceptible to metabolic alterations following high fat diet feeding.

    Directory of Open Access Journals (Sweden)

    Brittany V Martin-Murphy

    Full Text Available Current estimates suggest that over one-third of the adult population has metabolic syndrome and three-fourths of the obese population has non-alcoholic fatty liver disease (NAFLD. Inflammation in metabolic tissues has emerged as a universal feature of obesity and its co-morbidities, including NAFLD. Natural Killer T (NKT cells are a subset of innate immune cells that abundantly reside within the liver and are readily activated by lipid antigens. There is general consensus that NKT cells are pivotal regulators of inflammation; however, disagreement exists as to whether NKT cells exert pathogenic or suppressive functions in obesity. Here we demonstrate that CD1d(-/- mice, which lack NKT cells, were more susceptible to weight gain and fatty liver following high fat diet (HFD feeding. Compared with their WT counterparts, CD1d(-/- mice displayed increased adiposity and greater induction of inflammatory genes in the liver suggestive of the precursors of NAFLD. Calorimetry studies revealed a significant increase in food intake and trends toward decreased metabolic rate and activity in CD1d(-/- mice compared with WT mice. Based on these findings, our results suggest that NKT cells play a regulatory role that helps to prevent diet-induced obesity and metabolic dysfunction and may play an important role in mechanisms governing cross-talk between metabolism and the immune system to regulate energy balance and liver health.

  4. DNA vaccination with a plasmid encoding LACK-TSA fusion against Leishmania major infection in BALB/c mice.

    Science.gov (United States)

    Maspi, N; Ghaffarifar, F; Sharifi, Z; Dalimi, A; Khademi, S Z

    2017-12-01

    Vaccination would be the most important strategy for the prevention and elimination of leishmaniasis. The aim of the present study was to compare the immune responses induced following DNA vaccination with LACK (Leishmania analogue of the receptor kinase C), TSA (Thiol-specific-antioxidant) genes alone or LACK-TSA fusion against cutaneous leishmaniasis (CL). Cellular and humoral immune responses were evaluated before and after challenge with Leishmania major (L. major). In addition, the mean lesion size was also measured from 3th week post-infection. All immunized mice showed a partial immunity characterized by higher interferon (IFN)-γ and Immunoglobulin G (IgG2a) levels compared to control groups (pTSA fusion. Mean lesion sizes reduced significantly in all immunized mice compared with control groups at 7th week post-infection (pTSA and TSA groups than LACK group after challenge (pTSA antigens against CL. Furthermore, this study demonstrated that a bivalent vaccine can induce stronger immune responses and protection against infectious challenge with L. major.

  5. Ketamine Does Not Produce Relief of Neuropathic Pain in Mice Lacking the β-Common Receptor (CD131)

    Science.gov (United States)

    Swartjes, Maarten; Niesters, Marieke; Heij, Lara; Dunne, Ann; Aarts, Leon; Hand, Carla Cerami; Kim, Hyung-Suk; Brines, Michael; Cerami, Anthony; Dahan, Albert

    2013-01-01

    Neuropathic pain (NP) is a debilitating condition associated with traumatic, metabolic, autoimmune and neurological etiologies. Although the triggers for NP are diverse, there are common underlying pathways, including activation of immune cells in the spinal cord and up-regulation of the N-methyl-D-aspartate receptor (NMDAR). Ketamine, a well-known NDMAR antagonist, reduces neuropathic pain in a sustained manner. Recent study has shown that the novel 11-amino acid peptide erythropoietin derivative ARA290 produces a similar, long-lasting relief of NP. Here, we show that both drugs also have similar effects on the expression of mRNA of the NMDAR, as well as that of microglia, astrocytes and chemokine (C-C motif) ligand 2, all-important contributors to the development of NP. Although the effects of ketamine and ARA 290 on NP and its molecular mediators suggest a common mechanism of action, ARA 290 has no affinity for the NMDAR and acts specifically via the innate repair receptor (IRR) involved in tissue protection. We speculated therefore, that the IRR might be critically involved in the action of ketamine on neuropathic pain. To evaluate this, we studied the effects of ketamine and ARA 290 on acute pain, side effects, and allodynia following a spared nerve injury model in mice lacking the β-common receptor (βcR), a structural component of the IRR. Ketamine (50 mg/kg) and ARA 290 (30 µg/kg) produced divergent effects on acute pain: ketamine produced profound antinociception accompanied with psychomotor side effects, but ARA290 did not, in both normal and knock out mice. In contrast, while both drugs were antiallodynic in WT mice, they had no effect on NP in mice lacking the βcR. Together, these results show that an intact IRR is required for the effective treatment of NP with either ketamine or ARA 290, but is not involved in ketamine’s analgesic and side effects. PMID:23936499

  6. Prolongation of chemically-induced methemoglobinemia in mice lacking α-synuclein: A novel pharmacologic and toxicologic phenotype

    Directory of Open Access Journals (Sweden)

    Yien-Ming Kuo

    2015-01-01

    Full Text Available The protein α-synuclein is considered central to the pathogenesis of Parkinson disease (PD on genetic and histopathological grounds. It is widely expressed in fetal life and continues to be highly expressed in adult neural tissues, red blood cells and platelets, while the remainder of adult tissues are reported to have little or no expression. Despite cellular and molecular evidence for a role in neuronal function including synaptic vesicle trafficking, neurotransmitter release, mitochondrial function, lipid metabolism, neurogenesis, neuroprotection, and neuromelanin biosynthesis, mice ablated for the gene encoding α-synuclein (Snca have little or no neurological phenotype. Thus, nearly 20 years of intensive study have yet to reveal conclusively what the normal function of this highly abundant protein is in the nervous system. Interestingly, α-synuclein has also been shown to have enzymatic activity as a ferrireductase capable of reducing Fe+3 to Fe+2. Given its abundant expression in red blood cells, we set out to explore the role of α-synuclein in converting chemically-induced Fe+3 methemoglobin to normal Fe+2 hemoglobin. Initial in vivo experiments with the potent methemoglobin inducer, para-aminopropiophenone and its active metabolite, 4-hydroxy para-aminopropiophenone, demonstrated significantly greater and more prolonged methemoglobinemia in Snca−/− mice compared to Snca+/+ mice. In vitro experiments with red blood cells, however, and in vivo experiments in genetically engineered mouse strains that differ in their α-synuclein expression in various tissues, including the nervous system, red blood cells and liver, revealed that contrary to the initial hypothesis, a lack of expression of α-synuclein in red blood cells did not correlate with higher levels or more prolonged duration of methemoglobinemia. Instead, the greater sensitivity to chemically induced methemoglobinemia correlated with the absence of hepatic

  7. Minor abnormalities of testis development in mice lacking the gene encoding the MAPK signalling component, MAP3K1.

    Directory of Open Access Journals (Sweden)

    Nick Warr

    2011-05-01

    Full Text Available In mammals, the Y chromosome is a dominant male determinant, causing the bipotential gonad to develop as a testis. Recently, cases of familial and spontaneous 46,XY disorders of sex development (DSD have been attributed to mutations in the human gene encoding mitogen-activated protein kinase kinase kinase 1, MAP3K1, a component of the mitogen-activated protein kinase (MAPK signal transduction pathway. In individuals harbouring heterozygous mutations in MAP3K1, dysregulation of MAPK signalling was observed in lymphoblastoid cell lines, suggesting a causal role for these mutations in disrupting XY sexual development. Mice lacking the cognate gene, Map3k1, are viable and exhibit the eyes open at birth (EOB phenotype on a mixed genetic background, but on the C57BL/6J genetic background most mice die at around 14.5 dpc due to a failure of erythropoiesis in the fetal liver. However, no systematic examination of sexual development in Map3k1-deficient mice has been described, an omission that is especially relevant in the case of C57BL/6J, a genetic background that is sensitized to disruptions to testis determination. Here, we report that on a mixed genetic background mice lacking Map3k1 are fertile and exhibit no overt abnormalities of testis development. On C57BL/6J, significant non-viability is observed with very few animals surviving to adulthood. However, an examination of development in Map3k1-deficient XY embryos on this genetic background revealed no significant defects in testis determination, although minor abnormalities were observed, including an increase in gonadal length. Based on these observations, we conclude that MAP3K1 is not required for mouse testis determination. We discuss the significance of these data for the functional interpretation of sex-reversing MAP3K1 mutations in humans.

  8. Symbiotic Burkholderia Species Show Diverse Arrangements of nif/fix and nod Genes and Lack Typical High-Affinity Cytochrome cbb3 Oxidase Genes.

    Science.gov (United States)

    De Meyer, Sofie E; Briscoe, Leah; Martínez-Hidalgo, Pilar; Agapakis, Christina M; de-Los Santos, Paulina Estrada; Seshadri, Rekha; Reeve, Wayne; Weinstock, George; O'Hara, Graham; Howieson, John G; Hirsch, Ann M

    2016-08-01

    Genome analysis of fourteen mimosoid and four papilionoid beta-rhizobia together with fourteen reference alpha-rhizobia for both nodulation (nod) and nitrogen-fixing (nif/fix) genes has shown phylogenetic congruence between 16S rRNA/MLSA (combined 16S rRNA gene sequencing and multilocus sequence analysis) and nif/fix genes, indicating a free-living diazotrophic ancestry of the beta-rhizobia. However, deeper genomic analysis revealed a complex symbiosis acquisition history in the beta-rhizobia that clearly separates the mimosoid and papilionoid nodulating groups. Mimosoid-nodulating beta-rhizobia have nod genes tightly clustered in the nodBCIJHASU operon, whereas papilionoid-nodulating Burkholderia have nodUSDABC and nodIJ genes, although their arrangement is not canonical because the nod genes are subdivided by the insertion of nif and other genes. Furthermore, the papilionoid Burkholderia spp. contain duplications of several nod and nif genes. The Burkholderia nifHDKEN and fixABC genes are very closely related to those found in free-living diazotrophs. In contrast, nifA is highly divergent between both groups, but the papilionoid species nifA is more similar to alpha-rhizobia nifA than to other groups. Surprisingly, for all Burkholderia, the fixNOQP and fixGHIS genes required for cbb3 cytochrome oxidase production and assembly are missing. In contrast, symbiotic Cupriavidus strains have fixNOQPGHIS genes, revealing a divergence in the evolution of two distinct electron transport chains required for nitrogen fixation within the beta-rhizobia.

  9. Gene expression profiling of gastric mucosa in mice lacking CCK and gastrin receptors

    DEFF Research Database (Denmark)

    Zhao, Chun-Mei; Kodama, Yosuke; Flatberg, Arnar

    2014-01-01

    normalized, which was associated with an up-regulated pituitary adenylate cyclase-activating polypeptide (PACAP) type 1 receptor (PAC1). The basal part of the gastric mucosa expressed parathyroid hormone-like hormone (PTHLH) in a subpopulation of likely ECL cells (and possibly other cells) and vitamin D3 1α...... suggest a possible link between gastric PTHLH and vitamin D and bone metabolism.......The stomach produces acid, which may play an important role in the regulation of bone homeostasis. The aim of this study was to reveal signaling pathways in the gastric mucosa that involve the acid secretion and possibly the bone metabolism in CCK1 and/or CCK2 receptor knockout (KO) mice. Gastric...

  10. Aggressive Behavior and Altered Amounts of Brain Serotonin and Norepinephrine in Mice Lacking MAOA

    Science.gov (United States)

    Cases, Olivier; Grimsby, Joseph; Gaspar, Patricia; Chen, Kevin; Pournin, Sandrine; Müller, Ulrike; Aguet, Michel; Babinet, Charles; Shih, Jean Chen; De Maeyer, Edward

    2010-01-01

    Deficiency in monoamine oxidase A (MAOA), an enzyme that degrades serotonin and norepinephrine, has recently been shown to be associated with aggressive behavior in men of a Dutch family. A line of transgenic mice was isolated in which transgene integration caused a deletion in the gene encoding MAOA, providing an animal model of MAOA deficiency. In pup brains, serotonin concentrations were increased up to ninefold, and serotonin-like immunoreactivity was present in catecholaminergic neurons. In pup and adult brains, norepinephrine concentrations were increased up to twofold, and cytoarchitectural changes were observed in the somatosensory cortex. Pup behavioral alterations, including trembling, difficulty in righting, and fearfulness were reversed by the serotonin synthesis inhibitor parachlorophenylalanine. Adults manifested a distinct behavioral syndrome, including enhanced aggression in males. PMID:7792602

  11. Data on cytochrome c oxidase assembly in mice and human fibroblasts or tissues induced by SURF1 defect

    Czech Academy of Sciences Publication Activity Database

    Kovářová, Nikola; Pecina, Petr; Nůsková, Hana; Vrbacký, Marek; Zeviani, M.; Mráček, Tomáš; Viscomi, C.; Houštěk, Josef

    2016-01-01

    Roč. 7, June 01 (2016), s. 1004-1009 ISSN 2352-3409 R&D Projects: GA ČR(CZ) GB14-36804G; GA MŠk(CZ) LL1204; GA MZd(CZ) NT12370 Institutional support: RVO:67985823 Keywords : cytochrome c oxidase * respiratory chain * SURF1 * knockout * doxycycline Subject RIV: EB - Genetics ; Molecular Biology

  12. Prenatal administration of the cytochrome P4501A inducer, Β-naphthoflavone (BNF), attenuates hyperoxic lung injury in newborn mice: Implications for bronchopulmonary dysplasia (BPD) in premature infants

    International Nuclear Information System (INIS)

    Couroucli, Xanthi I.; Liang Yanhong Wei; Jiang Weiwu; Wang Lihua; Barrios, Roberto; Yang Peiying; Moorthy, Bhagavatula

    2011-01-01

    Supplemental oxygen contributes to the development of bronchopulmonary dysplasia (BPD) in premature infants. In this investigation, we tested the hypothesis that prenatal treatment of pregnant mice (C57BL/6J) with the cytochrome P450 (CYP)1A1 inducer, ss-napthoflavone (BNF), will lead to attenuation of lung injury in newborns (delivered from these dams) exposed to hyperoxia by mechanisms entailing transplacental induction of hepatic and pulmonary CYP1A enzymes. Pregnant mice were administered the vehicle corn oil (CO) or BNF (40 mg/kg), i.p., once daily for 3 days on gestational days (17-19), and newborns delivered from the mothers were either maintained in room air or exposed to hyperoxia (> 95% O 2 ) for 1-5 days. After 3-5 days of hyperoxia, the lungs of CO-treated mice showed neutrophil infiltration, pulmonary edema, and perivascular inflammation. On the other hand, BNF-pretreated neonatal mice showed decreased susceptibility to hyperoxic lung injury. These mice displayed marked induction of ethoxyresorufin O-deethylase (EROD) (CYP1A1) and methoxyresorufin O-demethylase (MROD) (CYP1A2) activities, and levels of the corresponding apoproteins and mRNA levels until PND 3 in liver, while CYP1A1 expression alone was augmented in the lung. Prenatal BNF did not significantly alter gene expression of pulmonary NAD(P)H quinone reductase (NQO1). Hyperoxia for 24-72 h resulted in increased pulmonary levels of the F 2 -isoprostane 8-iso-PGF 2α , whose levels were decreased in mice prenatally exposed to BNF. In conclusion, our results suggest that prenatal BNF protects newborns against hyperoxic lung injury, presumably by detoxification of lipid hydroperoxides by CYP1A enzymes, a phenomenon that has implications for prevention of BPD in infants. - Highlights: → Supplemental oxygen is routinely administered to premature infants. → Hyperoxia causes lung injury in experimental animals. → Prenatal treatment of mice with beta-naphthoflavone attenuates oxygen injury

  13. Milk Lacking α-Casein Leads to Permanent Reduction in Body Size in Mice

    Science.gov (United States)

    Kolb, Andreas F.; Huber, Reinhard C.; Lillico, Simon G.; Carlisle, Ailsa; Robinson, Claire J.; Neil, Claire; Petrie, Linda; Sorensen, Dorte B.; Olsson, I. Anna S.; Whitelaw, C. Bruce A.

    2011-01-01

    The major physiological function of milk is the transport of amino acids, carbohydrates, lipids and minerals to mammalian offspring. Caseins, the major milk proteins, are secreted in the form of a micelle consisting of protein and calcium-phosphate. We have analysed the role of the milk protein α-casein by inactivating the corresponding gene in mice. Absence of α-casein protein significantly curtails secretion of other milk proteins and calcium-phosphate, suggesting a role for α-casein in the establishment of casein micelles. In contrast, secretion of albumin, which is not synthesized in the mammary epithelium, into milk is not reduced. The absence of α-casein also significantly inhibits transcription of the other casein genes. α-Casein deficiency severely delays pup growth during lactation and results in a life-long body size reduction compared to control animals, but has only transient effects on physical and behavioural development of the pups. The data support a critical role for α-casein in casein micelle assembly. The results also confirm lactation as a critical window of metabolic programming and suggest milk protein concentration as a decisive factor in determining adult body weight. PMID:21789179

  14. Milk lacking α-casein leads to permanent reduction in body size in mice.

    Directory of Open Access Journals (Sweden)

    Andreas F Kolb

    Full Text Available The major physiological function of milk is the transport of amino acids, carbohydrates, lipids and minerals to mammalian offspring. Caseins, the major milk proteins, are secreted in the form of a micelle consisting of protein and calcium-phosphate.We have analysed the role of the milk protein α-casein by inactivating the corresponding gene in mice. Absence of α-casein protein significantly curtails secretion of other milk proteins and calcium-phosphate, suggesting a role for α-casein in the establishment of casein micelles. In contrast, secretion of albumin, which is not synthesized in the mammary epithelium, into milk is not reduced. The absence of α-casein also significantly inhibits transcription of the other casein genes. α-Casein deficiency severely delays pup growth during lactation and results in a life-long body size reduction compared to control animals, but has only transient effects on physical and behavioural development of the pups. The data support a critical role for α-casein in casein micelle assembly. The results also confirm lactation as a critical window of metabolic programming and suggest milk protein concentration as a decisive factor in determining adult body weight.

  15. Epithelial cell stretching and luminal acidification lead to a retarded development of stria vascularis and deafness in mice lacking pendrin.

    Directory of Open Access Journals (Sweden)

    Hyoung-Mi Kim

    2011-03-01

    Full Text Available Loss-of-function mutations of SLC26A4/pendrin are among the most prevalent causes of deafness. Deafness and vestibular dysfunction in the corresponding mouse model, Slc26a4(-/-, are associated with an enlargement and acidification of the membranous labyrinth. Here we relate the onset of expression of the HCO(3 (- transporter pendrin to the luminal pH and to enlargement-associated epithelial cell stretching. We determined expression with immunocytochemistry, cell stretching by digital morphometry and pH with double-barreled ion-selective electrodes. Pendrin was first expressed in the endolymphatic sac at embryonic day (E 11.5, in the cochlear hook-region at E13.5, in the utricle and saccule at E14.5, in ampullae at E16.5, and in the upper turn of the cochlea at E17.5. Epithelial cell stretching in Slc26a4(-/- mice began at E14.5. pH changes occurred first in the cochlea at E15.5 and in the endolymphatic sac at E17.5. At postnatal day 2, stria vascularis, outer sulcus and Reissner's membrane epithelial cells, and utricular and saccular transitional cells were stretched, whereas sensory cells in the cochlea, utricle and saccule did not differ between Slc26a4(+/- and Slc26a4(-/- mice. Structural development of stria vascularis, including vascularization, was retarded in Slc26a4(-/- mice. In conclusion, the data demonstrate that the enlargement and stretching of non-sensory epithelial cells precedes luminal acidification in the cochlea and the endolymphatic sac. Stretching and luminal acidification may alter cell-to-cell communication and lead to the observed retarded development of stria vascularis, which may be an important step on the path to deafness in Slc26a4(-/- mice, and possibly in humans, lacking functional pendrin expression.

  16. Data on cytochrome c oxidase assembly in mice and human fibroblasts or tissues induced by SURF1 defect

    Directory of Open Access Journals (Sweden)

    Nikola Kovářová

    2016-06-01

    Full Text Available This paper describes data related to a research article entitled “Tissue- and species-specific differences in cytochrome c oxidase assembly induced by SURF1 defects” [1]. This paper includes data of the quantitative analysis of individual forms of respiratory chain complexes I, III and IV present in SURF1 knockout (SURF1−/− and control (SURF1+/+ mouse fibroblasts and tissues and in fibroblasts of human control and patients with SURF1 gene mutation. Also it includes data demonstrating response of complex IV, cytochrome c oxidase (COX, to reversible inhibition of mitochondrial translation in SURF1−/− mouse and SURF1 patient fibroblast cell lines.

  17. Female mice lacking cholecystokinin 1 receptors have compromised neurogenesis, and fewer dopaminergic cells in the olfactory bulb

    Directory of Open Access Journals (Sweden)

    Yi eSui

    2013-03-01

    Full Text Available Neurogenesis in the adult rodent brain is largely restricted to the subependymal zone (SVZ of the lateral ventricle and subgranular zone (SGZ of the dentate gyrus (DG. We examined whether cholecystokinin (CCK through actions mediated by CCK1 receptors (CCK1R is involved in regulating neurogenesis. Proliferating cells in the SVZ, measured by 5-bromo-2-deoxyuridine (BrdU injected 2 hours prior to death or by immunoreactivity against Ki67, were reduced by 37% and 42%, respectively, in female (but not male mice lacking CCK1Rs (CCK1R-/- compared to wild-type (WT. Generation of neuroblasts in the SVZ and rostral migratory stream was also affected, since the number of doublecortin (DCX-immunoreactive (ir neuroblasts in these regions decreased by 29%. In the SGZ of female CCK1R-/- mice, BrdU-positive (+ and Ki67-ir cells were reduced by 38% and 56%, respectively, while DCX-ir neuroblasts were down 80%. Subsequently, the effect of reduced SVZ/SGZ proliferation on the generation and survival of mature adult-born cells in female CCK1R-/- mice was examined. In the OB granule cell layer (GCL, the number of neuronal nuclei (NeuN-ir and calretinin-ir cells was stable compared to WT, and 42 days after BrdU injections, the number of BrdU+ cells co-expressing GABA- or NeuN-like immunoreactivity (LI was similar. Compared to WT, the granule cell layer of the DG in female CCK1R-/- mice had a similar number of calbindin-ir cells and BrdU+ cells co-expressing calbindin-LI 42 days after BrdU injections. However, the OB glomerular layer (GL of CCK1R-/- female mice had 11% fewer NeuN-ir cells, 23% less TH-ir cells, and a 38% and 29% reduction in BrdU+ cells that co-expressed TH-LI or GABA-LI, respectively. We conclude that CCK, via CCK1Rs, is involved in regulating the generation of proliferating cells and neuroblasts in the adult female mouse brain, and mechanisms are in place to maintain steady neuronal populations in the OB and DG when the rate of proliferation is

  18. Inhibition of Stat3 signaling ameliorates atrophy of the soleus muscles in mice lacking the vitamin D receptor.

    Science.gov (United States)

    Gopinath, Suchitra D

    2017-01-25

    Although skeletal muscle wasting has long been observed as a clinical outcome of impaired vitamin D signaling, precise molecular mechanisms that mediate the loss of muscle mass in the absence of vitamin D signaling are less clear. To determine the molecular consequences of vitamin D signaling, we analyzed the role of signal transducer and activator of transcription 3 (Stat3) signaling, a known contributor to various muscle wasting pathologies, in skeletal muscles. We isolated soleus (slow) and tibialis anterior (fast) muscles from mice lacking the vitamin D receptor (VDR -/- ) and used western blot analysis, quantitative RTPCR, and pharmacological intervention to analyze muscle atrophy in VDR -/- mice. We found that slow and fast subsets of muscles of the VDR -/- mice displayed elevated levels of phosphorylated Stat3 accompanied by an increase in Myostatin expression and signaling. Consequently, we observed reduced activity of mammalian target of rapamycin (mTOR) signaling components, ribosomal S6 kinase (p70S6K) and ribosomal S6 protein (rpS6), that regulate protein synthesis and cell size, respectively. Concomitantly, we observed an increase in atrophy regulators and a block in autophagic gene expression. An examination of the upstream regulation of Stat3 levels in VDR -/- muscles revealed an increase in IL-6 protein expression in the soleus, but not in the tibialis anterior muscles. To investigate the involvement of satellite cells (SCs) in atrophy in VDR -/- mice, we found that there was no significant deficit in SC numbers in VDR -/- muscles compared to the wild type. Unlike its expression within VDR -/- fibers, Myostatin levels in VDR -/- SCs from bulk muscles were similar to those of wild type. However, VDR -/- SCs induced to differentiate in culture displayed increased p-Stat3 signaling and Myostatin expression. Finally, VDR -/- mice injected with a Stat3 inhibitor displayed reduced Myostatin expression and function and restored active p70S6K and rpS6

  19. Low bone mass and changes in the osteocyte network in mice lacking autophagy in the osteoblast lineage.

    Science.gov (United States)

    Piemontese, Marilina; Onal, Melda; Xiong, Jinhu; Han, Li; Thostenson, Jeff D; Almeida, Maria; O'Brien, Charles A

    2016-04-11

    Autophagy maintains cell function and homeostasis by recycling intracellular components. This process is also required for morphological changes associated with maturation of some cell types. Osteoblasts are bone forming cells some of which become embedded in bone and differentiate into osteocytes. This transformation includes development of long cellular projections and a reduction in endoplasmic reticulum and mitochondria. We examined the role of autophagy in osteoblasts by deleting Atg7 using an Osterix1-Cre transgene, which causes recombination in osteoblast progenitors and their descendants. Mice lacking Atg7 in the entire osteoblast lineage had low bone mass and fractures associated with reduced numbers of osteoclasts and osteoblasts. Suppression of autophagy also reduced the amount of osteocyte cellular projections and led to retention of endoplasmic reticulum and mitochondria in osteocytes. These results demonstrate that autophagy in osteoblasts contributes to skeletal homeostasis and to the morphological changes associated with osteocyte formation.

  20. Lack of Pannexin 1 Alters Synaptic GluN2 Subunit Composition and Spatial Reversal Learning in Mice.

    Science.gov (United States)

    Gajardo, Ivana; Salazar, Claudia S; Lopez-Espíndola, Daniela; Estay, Carolina; Flores-Muñoz, Carolina; Elgueta, Claudio; Gonzalez-Jamett, Arlek M; Martínez, Agustín D; Muñoz, Pablo; Ardiles, Álvaro O

    2018-01-01

    Long-term potentiation (LTP) and long-term depression (LTD) are two forms of synaptic plasticity that have been considered as the cellular substrate of memory formation. Although LTP has received considerable more attention, recent evidences indicate that LTD plays also important roles in the acquisition and storage of novel information in the brain. Pannexin 1 (Panx1) is a membrane protein that forms non-selective channels which have been shown to modulate the induction of hippocampal synaptic plasticity. Animals lacking Panx1 or blockade of Pannexin 1 channels precludes the induction of LTD and facilitates LTP. To evaluate if the absence of Panx1 also affects the acquisition of rapidly changing information we trained Panx1 knockout (KO) mice and wild type (WT) littermates in a visual and hidden version of the Morris water maze (MWM). We found that KO mice find the hidden platform similarly although slightly quicker than WT animals, nonetheless, when the hidden platform was located in the opposite quadrant (OQ) to the previous learned location, KO mice spent significantly more time in the previous quadrant than in the new location indicating that the absence of Panx1 affects the reversion of a previously acquired spatial memory. Consistently, we observed changes in the content of synaptic proteins critical to LTD, such as GluN2 subunits of N-methyl-D-aspartate receptors (NMDARs), which changed their contribution to synaptic plasticity in conditions of Panx1 ablation. Our findings give further support to the role of Panx1 channels on the modulation of synaptic plasticity induction, learning and memory processes.

  1. Lack of Pannexin 1 Alters Synaptic GluN2 Subunit Composition and Spatial Reversal Learning in Mice

    Science.gov (United States)

    Gajardo, Ivana; Salazar, Claudia S.; Lopez-Espíndola, Daniela; Estay, Carolina; Flores-Muñoz, Carolina; Elgueta, Claudio; Gonzalez-Jamett, Arlek M.; Martínez, Agustín D.; Muñoz, Pablo; Ardiles, Álvaro O.

    2018-01-01

    Long-term potentiation (LTP) and long-term depression (LTD) are two forms of synaptic plasticity that have been considered as the cellular substrate of memory formation. Although LTP has received considerable more attention, recent evidences indicate that LTD plays also important roles in the acquisition and storage of novel information in the brain. Pannexin 1 (Panx1) is a membrane protein that forms non-selective channels which have been shown to modulate the induction of hippocampal synaptic plasticity. Animals lacking Panx1 or blockade of Pannexin 1 channels precludes the induction of LTD and facilitates LTP. To evaluate if the absence of Panx1 also affects the acquisition of rapidly changing information we trained Panx1 knockout (KO) mice and wild type (WT) littermates in a visual and hidden version of the Morris water maze (MWM). We found that KO mice find the hidden platform similarly although slightly quicker than WT animals, nonetheless, when the hidden platform was located in the opposite quadrant (OQ) to the previous learned location, KO mice spent significantly more time in the previous quadrant than in the new location indicating that the absence of Panx1 affects the reversion of a previously acquired spatial memory. Consistently, we observed changes in the content of synaptic proteins critical to LTD, such as GluN2 subunits of N-methyl-D-aspartate receptors (NMDARs), which changed their contribution to synaptic plasticity in conditions of Panx1 ablation. Our findings give further support to the role of Panx1 channels on the modulation of synaptic plasticity induction, learning and memory processes. PMID:29692709

  2. Lack of Pannexin 1 Alters Synaptic GluN2 Subunit Composition and Spatial Reversal Learning in Mice

    Directory of Open Access Journals (Sweden)

    Ivana Gajardo

    2018-04-01

    Full Text Available Long-term potentiation (LTP and long-term depression (LTD are two forms of synaptic plasticity that have been considered as the cellular substrate of memory formation. Although LTP has received considerable more attention, recent evidences indicate that LTD plays also important roles in the acquisition and storage of novel information in the brain. Pannexin 1 (Panx1 is a membrane protein that forms non-selective channels which have been shown to modulate the induction of hippocampal synaptic plasticity. Animals lacking Panx1 or blockade of Pannexin 1 channels precludes the induction of LTD and facilitates LTP. To evaluate if the absence of Panx1 also affects the acquisition of rapidly changing information we trained Panx1 knockout (KO mice and wild type (WT littermates in a visual and hidden version of the Morris water maze (MWM. We found that KO mice find the hidden platform similarly although slightly quicker than WT animals, nonetheless, when the hidden platform was located in the opposite quadrant (OQ to the previous learned location, KO mice spent significantly more time in the previous quadrant than in the new location indicating that the absence of Panx1 affects the reversion of a previously acquired spatial memory. Consistently, we observed changes in the content of synaptic proteins critical to LTD, such as GluN2 subunits of N-methyl-D-aspartate receptors (NMDARs, which changed their contribution to synaptic plasticity in conditions of Panx1 ablation. Our findings give further support to the role of Panx1 channels on the modulation of synaptic plasticity induction, learning and memory processes.

  3. Effect of basic fibroblast growth factor and cytochrome c peroxidase combination in transgenic mice corneal epithelial healing process after excimer laser photoablation

    Directory of Open Access Journals (Sweden)

    Sergio Zaccaria Scalinci

    2011-02-01

    Full Text Available Sergio Zaccaria Scalinci1, Lucia Scorolli1, Alessandro Meduri2, Pier Luigi Grenga3, Giulia Corradetti1, Cristian Metrangolo11Low Vision Center – University of Bologna, Bologna, Italy; 2Department of Surgical Specialities, Ophthalmology Clinic, University of Messina, Messina, Italy; 3Department of Ophthalmology, University of Rome "La Sapienza", Rome, ItalyPurpose: To evaluate the role of prepared basic fibroblast growth factor (bFGF and cytochrome c peroxidase (CCP combination eyedrops in corneal epithelial healing of transgenic mice (B6(A-Rperd12/J after excimer laser photoablation. Materials and methods: In this prospective study, 216 eyes of 108 mice underwent bilateral photorefractive keratectomy. We considered 4 groups: A, B, C, and D. Group A received standard topical postoperative therapy with tobramycin, diclofenac, and dexamethasone eyedrops plus CCP at 3 drops per day for a week or until corneal re-epithelialization was achieved. Group B received standard topical postoperative therapy plus bFGF eyedrops and phosphate-buffered saline (PBS 3 drops per day for a week or until corneal re-epithelialization was complete. In group C, 1 eye received standard topical postoperative therapy plus CCP eyedrops, bFGF eyedrops, and PBS 3 drops per day for a week or until corneal re-epithelialization was complete. Control eyes (group D received a standard topical postoperative therapy plus placebo eyedrops. Mice were followed-up for a week from the day after the surgery to evaluate the rate of corneal re-epithelialization.Results: Data were analyzed by ANOVA using the XLSTAT 2010 software. Eyes in group A, B, and C healed completely before the fifth postoperative day, achieving, respectively, a re-epithelialization time of 92 hours ± 10 SD, 90 hours ± 12 SD, and 86 hours ± 12 SD. Group D had a re-epithelialization time of 121 hours ± 8 SD (P < 0.05. No side effects or toxic effects were documented.Conclusions: Results suggest that re

  4. Sympathetic activity induced by naloxone-precipitated morphine withdrawal is blocked in genetically engineered mice lacking functional CRF1 receptor

    International Nuclear Information System (INIS)

    García-Carmona, Juan-Antonio; Martínez-Laorden, Elena; Milanés, María-Victoria; Laorden, María-Luisa

    2015-01-01

    There is large body evidence indicating that stress can lead to cardiovascular disease. However, the exact brain areas and the mechanisms involved remain to be revealed. Here, we performed a series of experiments to characterize the role of CRF1 receptor (CRF1R) in the stress response induced by naloxone-precipitated morphine withdrawal. The experiments were performed in the hypothalamic paraventricular nucleus (PVN) ventrolateral medulla (VLM), brain regions involved in the regulation of cardiovascular activity, and in the right ventricle by using genetically engineered mice lacking functional CRF1R levels (KO). Mice were treated with increasing doses of morphine and withdrawal was precipitated by naloxone administration. Noradrenaline (NA) turnover, c-Fos, expression, PKA and TH phosphorylated at serine 40, was evaluated by high-performance liquid chromatography (HPLC), immunohistochemistry and immunoblotting. Morphine withdrawal induced an enhancement of NA turnover in PVN in parallel with an increase in TH neurons expressing c-Fos in VLM in wild-type mice. In addition we have demonstrated an increase in NA turnover, TH phosphorylated at serine 40 and PKA levels in heart. The main finding of the present study was that NA turnover, TH positive neurons that express c-Fos, TH phosphorylated at serine 40 and PKA expression observed during morphine withdrawal were significantly inhibited in CRF1R KO mice. Our results demonstrate that CRF/CRF1R activation may contribute to the adaptive changes induced by naloxone-precipitated withdrawal in the heart and in the brain areas which modulate the cardiac sympathetic function and suggest that CRF/CRF1R pathways could be contributing to cardiovascular disease associated to opioid addiction. - Highlights: • Naloxone-precipitated morphine withdrawal increases sympathetic activity in the PVN and heart. • Co-localization of TH phosphorylated at serine 40/c-Fos in the VLM after morphine withdrawal • Naloxone

  5. Sympathetic activity induced by naloxone-precipitated morphine withdrawal is blocked in genetically engineered mice lacking functional CRF1 receptor

    Energy Technology Data Exchange (ETDEWEB)

    García-Carmona, Juan-Antonio; Martínez-Laorden, Elena; Milanés, María-Victoria; Laorden, María-Luisa

    2015-02-15

    There is large body evidence indicating that stress can lead to cardiovascular disease. However, the exact brain areas and the mechanisms involved remain to be revealed. Here, we performed a series of experiments to characterize the role of CRF1 receptor (CRF1R) in the stress response induced by naloxone-precipitated morphine withdrawal. The experiments were performed in the hypothalamic paraventricular nucleus (PVN) ventrolateral medulla (VLM), brain regions involved in the regulation of cardiovascular activity, and in the right ventricle by using genetically engineered mice lacking functional CRF1R levels (KO). Mice were treated with increasing doses of morphine and withdrawal was precipitated by naloxone administration. Noradrenaline (NA) turnover, c-Fos, expression, PKA and TH phosphorylated at serine 40, was evaluated by high-performance liquid chromatography (HPLC), immunohistochemistry and immunoblotting. Morphine withdrawal induced an enhancement of NA turnover in PVN in parallel with an increase in TH neurons expressing c-Fos in VLM in wild-type mice. In addition we have demonstrated an increase in NA turnover, TH phosphorylated at serine 40 and PKA levels in heart. The main finding of the present study was that NA turnover, TH positive neurons that express c-Fos, TH phosphorylated at serine 40 and PKA expression observed during morphine withdrawal were significantly inhibited in CRF1R KO mice. Our results demonstrate that CRF/CRF1R activation may contribute to the adaptive changes induced by naloxone-precipitated withdrawal in the heart and in the brain areas which modulate the cardiac sympathetic function and suggest that CRF/CRF1R pathways could be contributing to cardiovascular disease associated to opioid addiction. - Highlights: • Naloxone-precipitated morphine withdrawal increases sympathetic activity in the PVN and heart. • Co-localization of TH phosphorylated at serine 40/c-Fos in the VLM after morphine withdrawal • Naloxone

  6. Conditioned place preference and locomotor activity in response to methylphenidate, amphetamine and cocaine in mice lacking dopamine D4 receptors

    Energy Technology Data Exchange (ETDEWEB)

    Thanos, P.K.; Thanos, P.K.; Bermeo, C.; Rubinstein, M.; Suchland, K.L.; Wang, G.-J.; Grandy, D.K.; Volkow, N.D.

    2010-05-01

    Methylphenidate (MP) and amphetamine (AMPH) are the most frequently prescribed medications for the treatment of attention-deficit/hyperactivity disorder (ADHD). Both drugs are believed to derive their therapeutic benefit by virtue of their dopamine (DA)-enhancing effects, yet an explanation for the observation that some patients with ADHD respond well to one medication but not to the other remains elusive. The dopaminergic effects of MP and AMPH are also thought to underlie their reinforcing properties and ultimately their abuse. Polymorphisms in the human gene that codes for the DA D4 receptor (D4R) have been repeatedly associated with ADHD and may correlate with the therapeutic as well as the reinforcing effects of responses to these psychostimulant medications. Conditioned place preference (CPP) for MP, AMPH and cocaine were evaluated in wild-type (WT) mice and their genetically engineered littermates, congenic on the C57Bl/6J background, that completely lack D4Rs (knockout or KO). In addition, the locomotor activity in these mice during the conditioning phase of CPP was tested in the CPP chambers. D4 receptor KO and WT mice showed CPP and increased locomotor activity in response to each of the three psychostimulants tested. D4R differentially modulates the CPP responses to MP, AMPH and cocaine. While the D4R genotype affected CPP responses to MP (high dose only) and AMPH (low dose only) it had no effects on cocaine. Inasmuch as CPP is considered an indicator of sensitivity to reinforcing responses to drugs these data suggest a significant but limited role of D4Rs in modulating conditioning responses to MP and AMPH. In the locomotor test, D4 receptor KO mice displayed attenuated increases in AMPH-induced locomotor activity whereas responses to cocaine and MP did not differ. These results suggest distinct mechanisms for D4 receptor modulation of the reinforcing (perhaps via attenuating dopaminergic signalling) and locomotor properties of these stimulant drugs

  7. The Biology of Autoimmune Response in the Scurfy Mice that Lack the CD4+Foxp3+ Regulatory T-Cells.

    Science.gov (United States)

    Ju, Shyr-Te; Sharma, Rahul; Gaskin, Felicia; Kung, John T; Fu, Shu Man

    2012-04-04

    Due to a mutation in the Foxp3 transcription factor, Scurfy mice lack regulatory T-cells that maintain self-tolerance of the immune system. They develop multi-organ inflammation (MOI) and die around four weeks old. The affected organs are skin, tail, lungs and liver. In humans, endocrine and gastrointestinal inflammation are also observed, hence the disease is termed IPEX (Immunodysregulation, Polyendocrinopathy, Enteropathy, X-linked) syndrome. The three week period of fatal MOI offers a useful autoimmune model in which the controls by genetics, T-cell subsets, cytokines, and effector mechanisms could be efficiently investigated. In this report, we will review published work, summarize our recent studies of Scurfy double mutants lacking specific autoimmune-related genes, discuss the cellular and cytokine controls by these genes on MOI, the organ-specificities of the MOI controlled by environments, and the effector mechanisms regulated by specific Th cytokines, including several newly identified control mechanisms for organ-specific autoimmune response.

  8. Cytochrome oxidase assembly does not require catalytically active cytochrome C.

    Science.gov (United States)

    Barrientos, Antoni; Pierre, Danielle; Lee, Johnson; Tzagoloff, Alexander

    2003-03-14

    Cytochrome c oxidase (COX), the terminal enzyme of the mitochondrial respiratory chain, catalyzes the transfer of electrons from reduced cytochrome c to molecular oxygen. COX assembly requires the coming together of nuclear- and mitochondrial-encoded subunits and the assistance of a large number of nuclear gene products acting at different stages of maturation of the enzyme. In Saccharomyces cerevisiae, expression of cytochrome c, encoded by CYC1 and CYC7, is required not only for electron transfer but also for COX assembly through a still unknown mechanism. We have attempted to distinguish between a functional and structural requirement of cytochrome c in COX assembly. A cyc1/cyc7 double null mutant strain was transformed with the cyc1-166 mutant gene (Schweingruber, M. E., Stewart, J. W., and Sherman, F. (1979) J. Biol. Chem. 254, 4132-4143) that expresses stable but catalytically inactive iso-1-cytochrome c. The COX content of the cyc1/cyc7 double mutant strain harboring non-functional iso-1-cytochrome c has been characterized spectrally, functionally, and immunochemically. The results of these studies demonstrate that cytochrome c plays a structural rather than functional role in assembly of cytochrome c oxidase. In addition to its requirement for COX assembly, cytochrome c also affects turnover of the enzyme. Mutants containing wild type apocytochrome c in mitochondria lack COX, suggesting that only the folded and mature protein is able to promote COX assembly.

  9. Elevated blood pressure in cytochrome P4501A1 knockout mice is associated with reduced vasodilation to omega − 3 polyunsaturated fatty acids

    Energy Technology Data Exchange (ETDEWEB)

    Agbor, Larry N.; Walsh, Mary T.; Boberg, Jason R.; Walker, Mary K., E-mail: mwalker@salud.unm.edu

    2012-11-01

    In vitro cytochrome P4501A1 (CYP1A1) metabolizes omega − 3 polyunsaturated fatty acids (n − 3 PUFAs); eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), primarily to 17,18-epoxyeicosatetraenoic acid (17,18-EEQ) and 19,20-epoxydocosapentaenoic acid (19,20-EDP), respectively. These metabolites have been shown to mediate vasodilation via increases in nitric oxide (NO) and activation of potassium channels. We hypothesized that genetic deletion of CYP1A1 would reduce vasodilatory responses to n − 3 PUFAs, but not the metabolites, and increase blood pressure (BP) due to decreases in NO. We assessed BP by radiotelemetry in CYP1A1 wildtype (WT) and knockout (KO) mice ± NO synthase (NOS) inhibitor. We also assessed vasodilation to acetylcholine (ACh), EPA, DHA, 17,18-EEQ and 19,20-EDP in aorta and mesenteric arterioles. Further, we assessed vasodilation to an NO donor and to DHA ± inhibitors of potassium channels. CYP1A1 KO mice were hypertensive, compared to WT, (mean BP in mm Hg, WT 103 ± 1, KO 116 ± 1, n = 5/genotype, p < 0.05), and exhibited a reduced heart rate (beats per minute, WT 575 ± 5; KO 530 ± 7; p < 0.05). However, BP responses to NOS inhibition and vasorelaxation responses to ACh and an NO donor were normal in CYP1A1 KO mice, suggesting that NO bioavailability was not reduced. In contrast, CYP1A1 KO mice exhibited significantly attenuated vasorelaxation responses to EPA and DHA in both the aorta and mesenteric arterioles, but normal vasorelaxation responses to the CYP1A1 metabolites, 17,18-EEQ and 19,20-EDP, and normal responses to potassium channel inhibition. Taken together these data suggest that CYP1A1 metabolizes n − 3 PUFAs to vasodilators in vivo and the loss of these vasodilators may lead to increases in BP. -- Highlights: ► CYP1A1 KO mice are hypertensive. ► CYP1A1 KO mice exhibit reduced vasodilation responses to n-3 PUFAs. ► Constitutive CYP1A1 expression regulates blood pressure and vascular function.

  10. Elevated blood pressure in cytochrome P4501A1 knockout mice is associated with reduced vasodilation to omega − 3 polyunsaturated fatty acids

    International Nuclear Information System (INIS)

    Agbor, Larry N.; Walsh, Mary T.; Boberg, Jason R.; Walker, Mary K.

    2012-01-01

    In vitro cytochrome P4501A1 (CYP1A1) metabolizes omega − 3 polyunsaturated fatty acids (n − 3 PUFAs); eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), primarily to 17,18-epoxyeicosatetraenoic acid (17,18-EEQ) and 19,20-epoxydocosapentaenoic acid (19,20-EDP), respectively. These metabolites have been shown to mediate vasodilation via increases in nitric oxide (NO) and activation of potassium channels. We hypothesized that genetic deletion of CYP1A1 would reduce vasodilatory responses to n − 3 PUFAs, but not the metabolites, and increase blood pressure (BP) due to decreases in NO. We assessed BP by radiotelemetry in CYP1A1 wildtype (WT) and knockout (KO) mice ± NO synthase (NOS) inhibitor. We also assessed vasodilation to acetylcholine (ACh), EPA, DHA, 17,18-EEQ and 19,20-EDP in aorta and mesenteric arterioles. Further, we assessed vasodilation to an NO donor and to DHA ± inhibitors of potassium channels. CYP1A1 KO mice were hypertensive, compared to WT, (mean BP in mm Hg, WT 103 ± 1, KO 116 ± 1, n = 5/genotype, p < 0.05), and exhibited a reduced heart rate (beats per minute, WT 575 ± 5; KO 530 ± 7; p < 0.05). However, BP responses to NOS inhibition and vasorelaxation responses to ACh and an NO donor were normal in CYP1A1 KO mice, suggesting that NO bioavailability was not reduced. In contrast, CYP1A1 KO mice exhibited significantly attenuated vasorelaxation responses to EPA and DHA in both the aorta and mesenteric arterioles, but normal vasorelaxation responses to the CYP1A1 metabolites, 17,18-EEQ and 19,20-EDP, and normal responses to potassium channel inhibition. Taken together these data suggest that CYP1A1 metabolizes n − 3 PUFAs to vasodilators in vivo and the loss of these vasodilators may lead to increases in BP. -- Highlights: ► CYP1A1 KO mice are hypertensive. ► CYP1A1 KO mice exhibit reduced vasodilation responses to n-3 PUFAs. ► Constitutive CYP1A1 expression regulates blood pressure and vascular function.

  11. Suppression of cytochrome P450 reductase (POR) expression in hepatoma cells replicates the hepatic lipidosis observed in hepatic POR-null mice.

    Science.gov (United States)

    Porter, Todd D; Banerjee, Subhashis; Stolarczyk, Elzbieta I; Zou, Ling

    2011-06-01

    Cytochrome P450 reductase (POR) is a microsomal electron transport protein essential to cytochrome P450-mediated drug metabolism and sterol and bile acid synthesis. The conditional deletion of hepatic POR gene expression in mice results in a marked decrease in plasma cholesterol levels counterbalanced by the accumulation of triglycerides in lipid droplets in hepatocytes. To evaluate the role of cholesterol and bile acid synthesis in this hepatic lipidosis, as well as the possible role of lipid transport from peripheral tissues, we developed a stable, small interfering RNA (siRNA)-mediated cell culture model for the suppression of POR. POR mRNA and protein expression were decreased by greater than 50% in McArdle-RH7777 rat hepatoma cells 10 days after transfection with a POR-siRNA expression plasmid, and POR expression was nearly completely extinguished by day 20. Immunofluorescent analysis revealed a marked accumulation of lipid droplets in cells by day 15, accompanied by a nearly 2-fold increase in cellular triglyceride content, replicating the lipidosis seen in hepatic POR-null mouse liver. In contrast, suppression of CYP51A1 (lanosterol demethylase) did not result in lipid accumulation, indicating that loss of cholesterol synthesis is not the basis for this lipidosis. Indeed, addition of cholesterol to the medium appeared to augment the lipidosis in POR-suppressed cells, whereas removal of lipids from the medium reversed the lipidosis. Oxysterols did not accumulate in POR-suppressed cells, discounting a role for liver X receptor in stimulating triglyceride synthesis, but addition of chenodeoxycholate significantly repressed lipid accumulation, suggesting that the absence of bile acids and loss of farnesoid X receptor stimulation lead to excessive triglyceride synthesis.

  12. Normal autophagic activity in macrophages from mice lacking Gαi3, AGS3, or RGS19.

    Directory of Open Access Journals (Sweden)

    Ali Vural

    Full Text Available In macrophages autophagy assists antigen presentation, affects cytokine release, and promotes intracellular pathogen elimination. In some cells autophagy is modulated by a signaling pathway that employs Gαi3, Activator of G-protein Signaling-3 (AGS3/GPSM1, and Regulator of G-protein Signaling 19 (RGS19. As macrophages express each of these proteins, we tested their importance in regulating macrophage autophagy. We assessed LC3 processing and the formation of LC3 puncta in bone marrow derived macrophages prepared from wild type, Gnai3(-/-, Gpsm1(-/-, or Rgs19(-/- mice following amino acid starvation or Nigericin treatment. In addition, we evaluated rapamycin-induced autophagic proteolysis rates by long-lived protein degradation assays and anti-autophagic action after rapamycin induction in wild type, Gnai3(-/-, and Gpsm1(-/- macrophages. In similar assays we compared macrophages treated or not with pertussis toxin, an inhibitor of GPCR (G-protein couple receptor triggered Gαi nucleotide exchange. Despite previous findings, the level of basal autophagy, autophagic induction, autophagic flux, autophagic degradation and the anti-autophagic action in macrophages that lacked Gαi3, AGS3, or RGS19; or had been treated with pertussis toxin, were similar to controls. These results indicate that while Gαi signaling may impact autophagy in some cell types it does not in macrophages.

  13. Normal hematopoiesis and lack of β-catenin activation in osteoblasts of patients and mice harboring Lrp5 gain of function mutations

    DEFF Research Database (Denmark)

    Galan-Diez, Marta; Isa, Adiba; Ponzetti, Marco

    2016-01-01

    of hematopoiesis and leukemogenic properties of β-catenin activation in osteoblasts, that lead to development of acute myeloid leukemia (AML). Using mice with gain-of-function (GOF) Lrp5 alleles (Lrp5(A214V)) that recapitulate the human high bone mass (HBM) phenotype, as well as patients with the T253I HBM Lrp5...... mutation, we show here that Lrp5 GOF mutations in both humans and mice do not activate β-catenin signaling in osteoblasts. Consistent with a lack of β-catenin activation in their osteoblasts, Lrp5(A214V) mice have normal trilinear hematopoiesis. In contrast to leukemic mice with constitutive activation...... of β-catenin in osteoblasts (Ctnnb1(CAosb)), accumulation of early myeloid progenitors, a characteristic of AML, myeloid-blasts in blood, and segmented neutrophils or dysplastic megakaryocytes in the bone marrow, are not observed in Lrp5(A214V) mice. Likewise, peripheral blood count analysis in HBM...

  14. Nonobese Diabetic (NOD Mice Lack a Protective B-Cell Response against the “Nonlethal” Plasmodium yoelii 17XNL Malaria Protozoan

    Directory of Open Access Journals (Sweden)

    Mirian Mendoza

    2016-01-01

    Full Text Available Background. Plasmodium yoelii 17XNL is a nonlethal malaria strain in mice of different genetic backgrounds including the C57BL/6 mice (I-Ab/I-Enull used in this study as a control strain. We have compared the trends of blood stage infection with the nonlethal murine strain of P. yoelii 17XNL malaria protozoan in immunocompetent Nonobese Diabetic (NOD mice prone to type 1 diabetes (T1D and C57BL/6 mice (control mice that are not prone to T1D and self-cure the P. yoelii 17XNL infection. Prediabetic NOD mice could not mount a protective antibody response to the P. yoelii 17XNL-infected red blood cells (iRBCs, and they all succumbed shortly after infection. Our data suggest that the lack of anti-P. yoelii 17XNL-iRBCs protective antibodies in NOD mice is a result of parasite-induced, Foxp3+ T regulatory (Treg cells able to suppress the parasite-specific antibody secretion. Conclusions. The NOD mouse model may help in identifying new mechanisms of B-cell evasion by malaria parasites. It may also serve as a more accurate tool for testing antimalaria therapeutics due to the lack of interference with a preexistent self-curing mechanism present in other mouse strains.

  15. Mice deficient in 11beta-hydroxysteroid dehydrogenase type 1 lack bone marrow adipocytes, but maintain normal bone formation

    DEFF Research Database (Denmark)

    Justesen, Jeannette; Mosekilde, Lis; Holmes, Megan

    2004-01-01

    Glucocorticoids (GCs) exert potent, but poorly characterized, effects on the skeleton. The cellular activity of GCs is regulated at a prereceptor level by 11beta-hydroxysteroid dehydrogenases (11betaHSDs). The type 1 isoform, which predominates in bone, functions as a reductase in intact cells...... and regenerates active cortisol (corticosterone) from circulating inert 11-keto forms. The aim of the present study was to investigate the role of this intracrine activation of GCs on normal bone physiology in vivo using mice deficient in 11betaHSD1 (HSD1(-/-)). The HSD1(-/-) mice exhibited no significant changes...... in cortical or trabecular bone mass compared with wild-type (Wt) mice. Aged HSD1(-/-) mice showed age-related bone loss similar to that observed in Wt mice. Histomorphometric analysis showed similar bone formation and bone resorption parameters in HSD1(-/-) and Wt mice. However, examination of bone marrow...

  16. Impact of fasting followed by short-term exposure to interleukin-6 on cytochrome P450 mRNA in mice.

    Science.gov (United States)

    Rasmussen, Martin Krøyer; Bertholdt, Lærke; Gudiksen, Anders; Pilegaard, Henriette; Knudsen, Jakob G

    2018-01-05

    The gene expression of the cytochrome P450 (CYP) enzyme family is regulated by numerous factors. Fasting has been shown to induce increased hepatic CYP mRNA in both humans and animals. However, the coordinated regulation of CYP, CYP-regulating transcription factors, and transcriptional co-factors in the liver linking energy metabolism to detoxification has never been investigated. Interleukin-6 (IL-6) has been suggested to be released during fasting and has been shown to regulate CYP expression. The present study investigated the hepatic mRNA content of selected CYP, AhR, CAR, PXR and PPARα in mice fasted for 18h and subsequently exposed to IL-6. Furthermore, the impact of fasting on PGC-1α, HNF-4α, SIRT1 and SIRT3 mRNA was examined. Fasting induced a marked increase in Cyp2b10, Cyp2e1 and Cyp4a10 mRNA, while CYP1a1, Cyp1a2, Cyp2a4 and Cyp3a11 mRNA levels remained unchanged. In accordance, the mRNA levels of CAR and PPARα were also increased with fasting. The PGC-1α, SIRT1 and SIRT3 mRNA levels were also increased after fasting, while the HNF-4α mRNA levels remained unchanged. In mice subjected to IL-6 injection, the fasting-induced PXR, PPARα and PGC-1α mRNA responses were lower than after saline injection. In conclusion, fasting was demonstrated to be a strong inducer of hepatic CYP mRNA as well as selected transcription factors controlling the expression of the investigated CYP. Moreover, the mRNA levels of transcriptional co-factors acting as energy sensors and co-factors for CYP regulation was also increased in the liver, suggesting crosstalk at the molecular level between regulation of energy metabolism and detoxification. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. Mice lacking the UbCKmit isoform of creatine kinase reveal slower spatial learning acquisition, diminished exploration and habituation, and reduced acoustic startle reflex responses.

    NARCIS (Netherlands)

    Streijger, F.; Jost, C.R.; Oerlemans, F.T.J.J.; Ellenbroek, B.A.; Cools, A.R.; Wieringa, B.; Zee, C.E.E.M. van der

    2004-01-01

    Brain-type creatine kinases B-CK (cytosolic) and UbCKmit (mitochondrial) are considered important for the maintenance and distribution of cellular energy in the central nervous system. Previously, we have demonstrated an abnormal behavioral phenotype in mice lacking the B-CK creatine kinase isoform,

  18. Identification and induction of cytochrome P450s involved in the metabolism of flavone-8-acetic acid in mice

    OpenAIRE

    Pham, Minh Hien; Rhinn, Hervé; Auzeil, Nicolas; Regazzetti, Anne; Harami, Djamel Eddine; Scherman, Daniel; Chabot, Guy G.

    2011-01-01

    The metabolism of flavone-8-acetic acid (FAA) has been hypothesized to be partly responsible for its potent anticancer activity in mice. The purpose of this study was to identify the mouse enzymes involved in FAA Phase I metabolism and evaluate their possible induction in vivo by FAA. Mouse microsomes metabolized FAA into 6 metabolites: 3′,4′-dihydrodiol-FAA, 5,6-epoxy-FAA, 4′-OH-FAA, 3′-OH-FAA, 3′,4′-epoxy-FAA and 6-OH-FAA. Using Cyp-specific inhibitors (furafylline, Cyp1a2; α-naphthoflavone...

  19. Normal viability and altered pharmacokinetics in mice lacking mdr1-type (drug-transporting) P-glycoproteins

    NARCIS (Netherlands)

    Schinkel, A. H.; Mayer, U.; Wagenaar, E.; Mol, C. A.; van Deemter, L.; Smit, J. J.; van der Valk, M. A.; Voordouw, A. C.; Spits, H.; van Tellingen, O.; Zijlmans, J. M.; Fibbe, W. E.; Borst, P.

    1997-01-01

    The mdr1-type P-glycoproteins (P-gps) confer multidrug resistance to cancer cells by active extrusion of a wide range of drugs from the cell. To study their physiological roles, we have generated mice genetically deficient in the mdr1b gene [mdr1b (-/-) mice] and in both the mdr1a and mdr1b genes

  20. Delayed contraction of the CD8+ T cell response toward lymphocytic choriomeningitis virus infection in mice lacking serglycin

    DEFF Research Database (Denmark)

    Grujic, Mirjana; Christensen, Jan P; Sørensen, Maria R

    2008-01-01

    (-/-)) mice with lymphocytic choriomeningitis virus (LCMV). Wt and SG(-/-) mice cleared 10(3) PFU of highly invasive LCMV with the same kinetics, and the CD8(+) T lymphocytes from wt and SG(-/-) animals did not differ in GrB, perforin, IFN-gamma, or TNF-alpha content. However, when a less invasive LCMV strain...

  1. Mice lacking collapsin response mediator protein 1 manifest hyperactivity, impaired learning and memory, and impaired prepulse inhibition

    Directory of Open Access Journals (Sweden)

    Naoya eYamashita

    2013-12-01

    Full Text Available Collapsin response mediator protein 1 (CRMP1 is one of the CRMP family members that are involved in various aspects of neuronal development such as axonal guidance and neuronal migration. Here we provide evidence that crmp1-/- mice exhibited behavioral abnormalities related to schizophrenia. The crmp1-/- mice exhibited hyperactivity and/or impaired emotional behavioral phenotype. These mice also exhibited impaired context-dependent memory and long-term memory retention. Furthermore, crmp1-/- mice exhibited decreased prepulse inhibition, and this phenotype was rescued by administration of chlorpromazine, a typical antipsychotic drug. In addition, in vivo microdialysis revealed that the methamphetamine-induced release of dopamine in prefrontal cortex was exaggerated in crmp1-/- mice, suggesting that enhanced mesocortical dopaminergic transmission contributes to their hyperactivity phenotype. These observations suggest that impairment of CRMP1 function may be involved in the pathogenesis of schizophrenia. We propose that crmp1-/- mouse may model endophenotypes present in this neuropsychiatric disorder.

  2. Identification of a cytochrome P4502E1/Bid/C1q-dependent axis mediating inflammation in adipose tissue after chronic ethanol feeding to mice.

    Science.gov (United States)

    Sebastian, Becky M; Roychowdhury, Sanjoy; Tang, Hui; Hillian, Antoinette D; Feldstein, Ariel E; Stahl, Gregory L; Takahashi, Kazue; Nagy, Laura E

    2011-10-14

    Chronic, heavy alcohol exposure results in inflammation in adipose tissue, insulin resistance, and liver injury. Here we have identified a CYP2E1/Bid/C1q-dependent pathway that is activated in response to chronic ethanol and is required for the development of inflammation in adipose tissue. Ethanol feeding for 25 days to wild-type (C57BL/6J) mice increased expression of multiple markers of adipose tissue inflammation relative to pair-fed controls independent of increased body weight or adipocyte size. Ethanol feeding increased the expression of CYP2E1 in adipocytes, but not stromal vascular cells, in adipose tissue and Cyp2e1(-/-) mice were protected from adipose tissue inflammation in response to ethanol. Ethanol feeding also increased the number of TUNEL-positive nuclei in adipose tissue of wild-type mice but not in Cyp2e1(-/-) or Bid (-/-) mice. Apoptosis contributed to adipose inflammation, as the expression of multiple inflammatory markers was decreased in mice lacking the Bid-dependent apoptotic pathway. The complement protein C1q binds to apoptotic cells, facilitating their clearance and activating complement. Making use of C1q-deficient mice, we found that activation of complement via C1q provided the critical link between CYP2E1/Bid-dependent apoptosis and onset of adipose tissue inflammation in response to chronic ethanol. In summary, chronic ethanol increases CYP2E1 activity in adipose, leading to Bid-mediated apoptosis and activation of complement via C1q, finally resulting in adipose tissue inflammation. Taken together, these data identify a novel mechanism for the development of adipose tissue inflammation that likely contributes to the pathophysiological effects of ethanol.

  3. Gender-specific induction of cytochrome P450s in nonylphenol-treated FVB/NJ mice

    International Nuclear Information System (INIS)

    Hernandez, Juan P.; Chapman, Laura M.; Kretschmer, Xiomara C.; Baldwin, William S.

    2006-01-01

    Nonylphenol (NP) is a breakdown product of nonylphenol ethoxylates, which are used in a variety of industrial, agricultural, household cleaning, and beauty products. NP is one of the most commonly found toxicants in the United States and Europe and is considered a toxicant of concern because of its long half-life. NP is an environmental estrogen that also activates the pregnane X-receptor (PXR) and in turn induces P450s. No study to date has examined the gender-specific effects of NP on hepatic P450 expression. We provided NP at 0, 50 or 75 mg/kg/day for 7 days to male and female FVB/NJ mice and compared their P450 expression profiles. Q-PCR was performed on hepatic cDNA using primers to several CYP isoforms regulated by PXR or its relative, the constitutive androstane receptor (CAR). In female mice, NP induced Cyp2b10 and Cyp2b13, and downregulated the female-specific P450s, Cyp3a41 and Cyp3a44. In contrast, male mice treated with NP showed increased expression of Cyp2a4, Cyp2b9, and Cyp2b10. Western blots confirmed induction of Cyp2b subfamily members in both males and females. Consistent with the Q-PCR data, Western blots showed dose-dependent downregulation of Cyp3a only in females and induction of Cyp2a only in males. The overall increase in female-predominant P450s in males (Cyp2a4, 2b9) and the decrease in female-predominant P450s in females (Cyp3a41, 3a44) suggest that NP is in part feminizing the P450 profile in males and masculinizing the P450 profile in females. Testosterone hydroxylation was also altered in a gender-specific manner, as testosterone 16α-hydroxylase activity was only induced in NP-treated males. In contrast, NP-treated females demonstrated a greater propensity for metabolizing zoxazolamine probably due to greater Cyp2b induction in females. In conclusion, NP causes gender-specific P450 induction and therefore exposure to NP may cause distinct pharmacological and toxicological effects in males compared to females

  4. Central diabetes insipidus associated with impaired renal aquaporin-1 expression in mice lacking liver X receptor β.

    Science.gov (United States)

    Gabbi, Chiara; Kong, Xiaomu; Suzuki, Hitoshi; Kim, Hyun-Jin; Gao, Min; Jia, Xiao; Ohnishi, Hideo; Ueta, Yoichi; Warner, Margaret; Guan, Youfei; Gustafsson, Jan-Åke

    2012-02-21

    The present study demonstrates a key role for the oxysterol receptor liver X receptor β (LXRβ) in the etiology of diabetes insipidus (DI). Given free access to water, LXRβ(-/-) but not LXRα(-/-) mice exhibited polyuria (abnormal daily excretion of highly diluted urine) and polydipsia (increased water intake), both features of diabetes insipidus. LXRβ(-/-) mice responded to 24-h dehydration with a decreased urine volume and increased urine osmolality. To determine whether the DI was of central or nephrogenic origin, we examined the responsiveness of the kidney to arginine vasopressin (AVP). An i.p. injection of AVP to LXRβ(-/-) mice revealed a partial kidney response: There was no effect on urine volume, but there was a significant increase of urine osmolality, suggesting that DI may be caused by a defect in central production of AVP. In the brain of WT mice LXRβ was expressed in the nuclei of magnocellular neurons in the supraoptic and paraventricular nuclei of the hypothalamus. In LXRβ(-/-) mice the expression of AVP was markedly decreased in the magnocellular neurons as well as in urine collected over a 24-h period. The persistent high urine volume after AVP administration was traced to a reduction in aquaporin-1 expression in the kidney of LXRβ(-/-) mice. The LXR agonist (GW3965) in WT mice elicited an increase in urine osmolality, suggesting that LXRβ is a key receptor in controlling water balance with targets in both the brain and kidney, and it could be a therapeutic target in disorders of water balance.

  5. Control of blood pressure, appetite, and glucose by leptin in mice lacking leptin receptors in proopiomelanocortin neurons.

    Science.gov (United States)

    do Carmo, Jussara M; da Silva, Alexandre A; Cai, Zhengwei; Lin, Shuying; Dubinion, John H; Hall, John E

    2011-05-01

    Although the central nervous system melanocortin system is an important regulator of energy balance, the role of proopiomelanocortin (POMC) neurons in mediating the chronic effects of leptin on appetite, blood pressure, and glucose regulation is unknown. Using Cre/loxP technology we tested whether leptin receptor deletion in POMC neurons (LepR(flox/flox)/POMC-Cre mice) attenuates the chronic effects of leptin to increase mean arterial pressure (MAP), enhance glucose use and oxygen consumption, and reduce appetite. LepR(flox/flox)/POMC-Cre, wild-type, LepR(flox/flox), and POMC-Cre mice were instrumented for MAP and heart rate measurement by telemetry and venous catheters for infusions. LepR(flox/flox)/POMC-Cre mice were heavier, hyperglycemic, hyperinsulinemic, and hyperleptinemic compared with wild-type, LepR(flox/flox), and POMC-Cre mice. Despite exhibiting features of metabolic syndrome, LepR(flox/flox)/POMC-Cre mice had normal MAP and heart rate compared with LepR(flox/flox) but lower MAP and heart rate compared with wild-type mice. After a 5-day control period, leptin was infused (2 μg/kg per minute, IV) for 7 days. In control mice, leptin increased MAP by ≈5 mm Hg despite decreasing food intake by ≈35%. In contrast, leptin infusion in LepR(flox/flox)/POMC-Cre mice reduced MAP by ≈3 mm Hg and food intake by ≈28%. Leptin significantly decreased insulin and glucose levels in control mice but not in LepR(flox/flox)/POMC-Cre mice. Leptin increased oxygen consumption in LepR(flox/flox)/POMC-Cre and wild-type mice. Activation of POMC neurons is necessary for the chronic effects of leptin to raise MAP and reduce insulin and glucose levels, whereas leptin receptors in other areas of the brain other than POMC neurons appear to play a key role in mediating the chronic effects of leptin on appetite and oxygen consumption.

  6. Antidepressive and BDNF effects of enriched environment treatment across ages in mice lacking BDNF expression through promoter IV

    Science.gov (United States)

    Jha, S; Dong, B E; Xue, Y; Delotterie, D F; Vail, M G; Sakata, K

    2016-01-01

    Reduced promoter IV-driven expression of brain-derived neurotrophic factor (BDNF) is implicated in stress and major depression. We previously reported that defective promoter IV (KIV) caused depression-like behavior in young adult mice, which was reversed more effectively by enriched environment treatment (EET) than antidepressants. The effects of promoter IV-BDNF deficiency and EET over the life stages remain unknown. Since early-life development (ED) involves dynamic epigenetic processes, we hypothesized that EET during ED would provide maximum antidepressive effects that would persist later in life due to enhanced, long-lasting BDNF induction. We tested this hypothesis by determining EET effects across three life stages: ED (0–2 months), young adult (2–4 months), and old adult (12–14 months). KIV mice at all life stages showed depression-like behavior in the open-field and tail-suspension tests compared with wild-type mice. Two months of EET reduced depression-like behavior in ED and young adult, but not old adult mice, with the largest effect in ED KIV mice. This effect lasted for 1 month after discontinuance of EET only in ED mice. BDNF protein induction by EET in the hippocampus and frontal cortex was also the largest in ED mice and persisted only in the hippocampus of ED KIV mice after discontinuance of EET. No gender-specific effects were observed. The results suggest that defective promoter IV causes depression-like behavior, regardless of age and gender, and that EET during ED is particularly beneficial to individuals with promoter IV-BDNF deficiency, while additional treatment may be needed for older adults. PMID:27648918

  7. Inositol- and folate-resistant neural tube defects in mice lacking the epithelial-specific factor Grhl-3.

    Science.gov (United States)

    Ting, Stephen B; Wilanowski, Tomasz; Auden, Alana; Hall, Mark; Voss, Anne K; Thomas, Tim; Parekh, Vishwas; Cunningham, John M; Jane, Stephen M

    2003-12-01

    The neural tube defects (NTDs) spina bifida and anencephaly are widely prevalent severe birth defects. The mouse mutant curly tail (ct/ct) has served as a model of NTDs for 50 years, even though the responsible genetic defect remained unrecognized. Here we show by gene targeting, mapping and genetic complementation studies that a mouse homolog of the Drosophila grainyhead (grh) gene, grainyhead-like-3 (Grhl3), is a compelling candidate for the gene underlying the curly tail phenotype. The NTDs in Grhl3-null mice are more severe than those in the curly tail strain, as the Grhl3 alleles in ct/ct mice are hypomorphic. Spina bifida in ct/ct mice is folate resistant, but its incidence can be markedly reduced by maternal inositol supplementation periconceptually. The NTDs in Grhl3-/- embryos are also folate resistant, but unlike those in ct/ct mice, they are resistant to inositol. These findings suggest that residual Grhl3 expression in ct/ct mice may be required for inositol rescue of folate-resistant NTDs.

  8. Skeletal development of mice lacking bone sialoprotein (BSP--impairment of long bone growth and progressive establishment of high trabecular bone mass.

    Directory of Open Access Journals (Sweden)

    Wafa Bouleftour

    Full Text Available Adult Ibsp-knockout mice (BSP-/- display shorter stature, lower bone turnover and higher trabecular bone mass than wild type, the latter resulting from impaired bone resorption. Unexpectedly, BSP knockout also affects reproductive behavior, as female mice do not construct a proper "nest" for their offsprings. Multiple crossing experiments nonetheless indicated that the shorter stature and lower weight of BSP-/- mice, since birth and throughout life, as well as their shorter femur and tibia bones are independent of the genotype of the mothers, and thus reflect genetic inheritance. In BSP-/- newborns, µCT analysis revealed a delay in membranous primary ossification, with wider cranial sutures, as well as thinner femoral cortical bone and lower tissue mineral density, reflected in lower expression of bone formation markers. However, trabecular bone volume and osteoclast parameters of long bones do not differ between genotypes. Three weeks after birth, osteoclast number and surface drop in the mutants, concomitant with trabecular bone accumulation. The growth plates present a thinner hypertrophic zone in newborns with lower whole bone expression of IGF-1 and higher IHH in 6 days old BSP-/- mice. At 3 weeks the proliferating zone is thinner and the hypertrophic zone thicker in BSP-/- than in BSP+/+ mice of either sex, maybe reflecting a combination of lower chondrocyte proliferation and impaired cartilage resorption. Six days old BSP-/- mice display lower osteoblast marker expression but higher MEPE and higher osteopontin(Opn/Runx2 ratio. Serum Opn is higher in mutants at day 6 and in adults. Thus, lack of BSP alters long bone growth and membranous/cortical primary bone formation and mineralization. Endochondral development is however normal in mutant mice and the accumulation of trabecular bone observed in adults develops progressively in the weeks following birth. Compensatory high Opn may allow normal endochondral development in BSP-/- mice

  9. Altered thalamocortical rhythmicity and connectivity in mice lacking CaV3.1 T-type Ca2+ channels in unconsciousness

    Science.gov (United States)

    Choi, Soonwook; Yu, Eunah; Lee, Seongwon; Llinás, Rodolfo R.

    2015-01-01

    In unconscious status (e.g., deep sleep and anesthetic unconsciousness) where cognitive functions are not generated there is still a significant level of brain activity present. Indeed, the electrophysiology of the unconscious brain is characterized by well-defined thalamocortical rhythmicity. Here we address the ionic basis for such thalamocortical rhythms during unconsciousness. In particular, we address the role of CaV3.1 T-type Ca2+ channels, which are richly expressed in thalamic neurons. Toward this aim, we examined the electrophysiological and behavioral phenotypes of mice lacking CaV3.1 channels (CaV3.1 knockout) during unconsciousness induced by ketamine or ethanol administration. Our findings indicate that CaV3.1 KO mice displayed attenuated low-frequency oscillations in thalamocortical loops, especially in the 1- to 4-Hz delta band, compared with control mice (CaV3.1 WT). Intriguingly, we also found that CaV3.1 KO mice exhibited augmented high-frequency oscillations during unconsciousness. In a behavioral measure of unconsciousness dynamics, CaV3.1 KO mice took longer to fall into the unconscious state than controls. In addition, such unconscious events had a shorter duration than those of control mice. The thalamocortical interaction level between mediodorsal thalamus and frontal cortex in CaV3.1 KO mice was significantly lower, especially for delta band oscillations, compared with that of CaV3.1 WT mice, during unconsciousness. These results suggest that the CaV3.1 channel is required for the generation of a given set of thalamocortical rhythms during unconsciousness. Further, that thalamocortical resonant neuronal activity supported by this channel is important for the control of vigilance states. PMID:26056284

  10. Enhanced leptin sensitivity and improved glucose homeostasis in mice lacking suppressor of cytokine signaling-3 in POMC-expressing cells.

    Science.gov (United States)

    Kievit, Paul; Howard, Jane K; Badman, Michael K; Balthasar, Nina; Coppari, Roberto; Mori, Hiroyuki; Lee, Charlotte E; Elmquist, Joel K; Yoshimura, Akihiko; Flier, Jeffrey S

    2006-08-01

    Suppressor of cytokine signaling-3 (Socs-3) negatively regulates the action of various cytokines, as well as the metabolic hormones leptin and insulin. Mice with haploinsufficiency of Socs-3, or those with neuronal deletion of Socs-3, are lean and more leptin and insulin sensitive. To examine the role of Socs-3 within specific neurons critical to energy balance, we created mice with selective deletion of Socs-3 within pro-opiomelanocortin (POMC)-expressing cells. These mice had enhanced leptin sensitivity, measured by weight loss and food intake after leptin infusion. On chow diet, glucose homeostasis was improved despite normal weight gain. On a high-fat diet, the rate of weight gain was reduced, due to increased energy expenditure rather than decreased food intake; glucose homeostasis and insulin sensitivity were substantially improved. These studies demonstrate that Socs-3 within POMC neurons regulates leptin sensitivity and glucose homeostasis, and plays a key role in linking high-fat diet to disordered metabolism.

  11. Mice Lacking the β2 Adrenergic Receptor Have a Unique Genetic Profile before and after Focal Brain Ischaemia

    Directory of Open Access Journals (Sweden)

    Robin E White

    2012-08-01

    Full Text Available The role of the β2AR (β2 adrenergic receptor after stroke is unclear as pharmacological manipulations of the β2AR have produced contradictory results. We previously showed that mice deficient in the β2AR (β2KO had smaller infarcts compared with WT (wild-type mice (FVB after MCAO (middle cerebral artery occlusion, a model of stroke. To elucidate mechanisms of this neuroprotection, we evaluated changes in gene expression using microarrays comparing differences before and after MCAO, and differences between genotypes. Genes associated with inflammation and cell deaths were enriched after MCAO in both genotypes, and we identified several genes not previously shown to increase following ischaemia (Ccl9, Gem and Prg4. In addition to networks that were similar between genotypes, one network with a central core of GPCR (G-protein-coupled receptor and including biological functions such as carbohydrate metabolism, small molecule biochemistry and inflammation was identified in FVB mice but not in β2KO mice. Analysis of differences between genotypes revealed 11 genes differentially expressed by genotype both before and after ischaemia. We demonstrate greater Glo1 protein levels and lower Pmaip/Noxa mRNA levels in β2KO mice in both sham and MCAO conditions. As both genes are implicated in NF-κB (nuclear factor κB signalling, we measured p65 activity and TNFα (tumour necrosis factor α levels 24 h after MCAO. MCAO-induced p65 activation and post-ischaemic TNFα production were both greater in FVB compared with β2KO mice. These results suggest that loss of β2AR signaling results in a neuroprotective phenotype in part due to decreased NF-κB signalling, decreased inflammation and decreased apoptotic signalling in the brain.

  12. IGF-II is up-regulated and myofibres are hypertrophied in regenerating soleus of mice lacking FGF6

    International Nuclear Information System (INIS)

    Armand, Anne-Sophie; Lecolle, Sylvie; Launay, Thierry; Pariset, Claude; Fiore, Frederic; Della Gaspera, Bruno; Birnbaum, Daniel; Chanoine, Christophe; Charbonnier, Frederic

    2004-01-01

    Important functions in myogenesis have been proposed for FGF6, a member of the fibroblast growth factor family accumulating almost exclusively in the myogenic lineage. However, the use of FGF6(-/-) mutant mice gave contradictory results and the role of FGF6 during myogenesis remains largely unclear. Using FGF6(-/-) mice, we first analysed the morphology of the regenerated soleus following cardiotoxin injection and showed hypertrophied myofibres in soleus of the mutant mice as compared to wild-type mice. Secondly, to examine the function of the IGF family in the hypertrophy process, we used semiquantitative and real-time RT-PCR assays and Western blots to monitor the expression of the insulin-like growth factors (IGF-I and IGF-II), their receptors [type I IGF receptor (IGF1R) and IGF-II receptor (IGF2R)], and of a binding protein IGFBP-5 in regenerating soleus muscles of FGF6(-/-) knockout mice vs. wild-type mice. In the mutant, both IGF-II and IGF2R, but not IGF-I and IGF1R, were strongly up-regulated, whereas IGFBP5 was down-regulated, strongly suggesting that, in the absence of FGF6, the mechanisms leading to myofibre hypertrophy were mediated specifically by an IGF-II/IGF2R signalling pathway distinct from the classic mechanism involving IGF-I and IGF1R previously described for skeletal muscle hypertrophy. The potential regulating role of IGFBP5 on IGF-II expression is also discussed. This report shows for the first time a specific role for FGF6 in the regulation of myofibre size during a process of in vivo myogenesis

  13. Depressed levels of prostaglandin F2α in mice lacking Akr1b7 increase basal adiposity and predispose to diet-induced obesity.

    Science.gov (United States)

    Volat, Fanny E; Pointud, Jean-Christophe; Pastel, Emilie; Morio, Béatrice; Sion, Benoit; Hamard, Ghislaine; Guichardant, Michel; Colas, Romain; Lefrançois-Martinez, Anne-Marie; Martinez, Antoine

    2012-11-01

    Negative regulators of white adipose tissue (WAT) expansion are poorly documented in vivo. Prostaglandin F(2α) (PGF(2α)) is a potent antiadipogenic factor in cultured preadipocytes, but evidence for its involvement in physiological context is lacking. We previously reported that Akr1b7, an aldo-keto reductase enriched in adipose stromal vascular fraction but absent from mature adipocytes, has antiadipogenic properties possibly supported by PGF(2α) synthase activity. To test whether lack of Akr1b7 could influence WAT homeostasis in vivo, we generated Akr1b7(-/-) mice in 129/Sv background. Akr1b7(-/-) mice displayed excessive basal adiposity resulting from adipocyte hyperplasia/hypertrophy and exhibited greater sensitivity to diet-induced obesity. Following adipose enlargement and irrespective of the diet, they developed liver steatosis and progressive insulin resistance. Akr1b7 loss was associated with decreased PGF(2α) WAT contents. Cloprostenol (PGF(2α) agonist) administration to Akr1b7(-/-) mice normalized WAT expansion by affecting both de novo adipocyte differentiation and size. Treatment of 3T3-L1 adipocytes and Akr1b7(-/-) mice with cloprostenol suggested that decreased adipocyte size resulted from inhibition of lipogenic gene expression. Hence, Akr1b7 is a major regulator of WAT development through at least two PGF(2α)-dependent mechanisms: inhibition of adipogenesis and lipogenesis. These findings provide molecular rationale to explore the status of aldo-keto reductases in dysregulations of adipose tissue homeostasis.

  14. Dwarfism in mice lacking collagen-binding integrins alpha 2 beta 1 and alpha 11 beta 1 is caused by severely diminished IGF-1 levels

    OpenAIRE

    Blumbach, Katrin; Niehoff, Anja; Belgardt, Bengt F.; Ehlen, Harald W.A.; Schmitz, Markus; Hallinger, Ralf; Schulz, Jan-Niklas; Brüning, Jens C.; Krieg, Thomas; Schubert, Markus; Gullberg, Donald; Eckes, Beate

    2012-01-01

    Mice with a combined deficiency in the α2β1 and α11β1 integrins lack the major receptors for collagen I. These mutants are born with inconspicuous differences in size but develop dwarfism within the first 4 weeks of life. Dwarfism correlates with shorter, less mineralized and functionally weaker bones that do not result from growth plate abnormalities or osteoblast dysfunction. Besides skeletal dwarfism, internal organs are correspondingly smaller, indicating proportional dwarfism and suggest...

  15. Mice Lacking the Alpha9 Subunit of the Nicotinic Acetylcholine Receptor Exhibit Deficits in Frequency Difference Limens and Sound Localization

    Directory of Open Access Journals (Sweden)

    Amanda Clause

    2017-06-01

    Full Text Available Sound processing in the cochlea is modulated by cholinergic efferent axons arising from medial olivocochlear neurons in the brainstem. These axons contact outer hair cells in the mature cochlea and inner hair cells during development and activate nicotinic acetylcholine receptors composed of α9 and α10 subunits. The α9 subunit is necessary for mediating the effects of acetylcholine on hair cells as genetic deletion of the α9 subunit results in functional cholinergic de-efferentation of the cochlea. Cholinergic modulation of spontaneous cochlear activity before hearing onset is important for the maturation of central auditory circuits. In α9KO mice, the developmental refinement of inhibitory afferents to the lateral superior olive is disturbed, resulting in decreased tonotopic organization of this sound localization nucleus. In this study, we used behavioral tests to investigate whether the circuit anomalies in α9KO mice correlate with sound localization or sound frequency processing. Using a conditioned lick suppression task to measure sound localization, we found that three out of four α9KO mice showed impaired minimum audible angles. Using a prepulse inhibition of the acoustic startle response paradigm, we found that the ability of α9KO mice to detect sound frequency changes was impaired, whereas their ability to detect sound intensity changes was not. These results demonstrate that cholinergic, nicotinic α9 subunit mediated transmission in the developing cochlear plays an important role in the maturation of hearing.

  16. Action potential generation in the small intestine of W mutant mice that lack interstitial cells of Cajal

    DEFF Research Database (Denmark)

    Malysz, J; Thuneberg, L; Mikkelsen, Hanne Birte

    1996-01-01

    significantly changed. Neither FLC nor MLC were part of a network nor did they form specialized junctions with neighboring cells as ICC do. Hence no cell type had replaced ICC at their normal morphological position associated with Auerbach's plexus. ICC were present in W/Wv mice at the deep muscular plexus...

  17. Mice lacking the transcriptional regulator Bhlhe40 have enhanced neuronal excitability and impaired synaptic plasticity in the hippocampus.

    Directory of Open Access Journals (Sweden)

    Kelly A Hamilton

    Full Text Available Bhlhe40 is a transcription factor that is highly expressed in the hippocampus; however, its role in neuronal function is not well understood. Here, we used Bhlhe40 null mice on a congenic C57Bl6/J background (Bhlhe40 KO to investigate the impact of Bhlhe40 on neuronal excitability and synaptic plasticity in the hippocampus. Bhlhe40 KO CA1 neurons had increased miniature excitatory post-synaptic current amplitude and decreased inhibitory post-synaptic current amplitude, indicating CA1 neuronal hyperexcitability. Increased CA1 neuronal excitability was not associated with increased seizure severity as Bhlhe40 KO relative to +/+ (WT control mice injected with the convulsant kainic acid. However, significant reductions in long term potentiation and long term depression at CA1 synapses were observed in Bhlhe40 KO mice, indicating impaired hippocampal synaptic plasticity. Behavioral testing for spatial learning and memory on the Morris Water Maze (MWM revealed that while Bhlhe40 KO mice performed similarly to WT controls initially, when the hidden platform was moved to the opposite quadrant Bhlhe40 KO mice showed impairments in relearning, consistent with decreased hippocampal synaptic plasticity. To investigate possible mechanisms for increased neuronal excitability and decreased synaptic plasticity, a whole genome mRNA expression profile of Bhlhe40 KO hippocampus was performed followed by a chromatin immunoprecipitation sequencing (ChIP-Seq screen of the validated candidate genes for Bhlhe40 protein-DNA interactions consistent with transcriptional regulation. Of the validated genes identified from mRNA expression analysis, insulin degrading enzyme (Ide had the most significantly altered expression in hippocampus and was significantly downregulated on the RNA and protein levels; although Bhlhe40 did not occupy the Ide gene by ChIP-Seq. Together, these findings support a role for Bhlhe40 in regulating neuronal excitability and synaptic plasticity in

  18. Environmental enrichment reduces innate anxiety with no effect on depression-like behaviour in mice lacking the serotonin transporter.

    Science.gov (United States)

    Rogers, Jake; Li, Shanshan; Lanfumey, Laurence; Hannan, Anthony J; Renoir, Thibault

    2017-08-14

    Along with being the main target of many antidepressant medications, the serotonin transporter (5-HTT) is known to be involved in the pathophysiology of depression and anxiety disorders. In line with this, mice with varying 5-HTT genotypes are invaluable tools to study depression- and anxiety-like behaviours as well as the mechanisms mediating potential therapeutics. There is clear evidence that both genetic and environmental factors play a role in the aetiology of psychiatric disorders. In that regard, housing paradigms which seek to enhance cognitive stimulation and physical activity have been shown to exert beneficial effects in animal models of neuropsychiatric disorders. In the present study, we examined the effects of environmental enrichment on affective-like behaviours and sensorimotor gating function of 5-HTT knock-out (KO) mice. Using the elevated-plus maze and the light-dark box, we found that environmental enrichment ameliorated the abnormal innate anxiety of 5-HTT KO mice on both tests. In contrast, environmental enrichment did not rescue the depression-like behaviour displayed by 5-HTT KO mice in the forced-swim test. Finally, measuring pre-pulse inhibition, we found no effect of genotype or treatment on sensorimotor gating. In conclusion, our data suggest that environmental enrichment specifically reduces innate anxiety of 5-HTT KO mice with no amelioration of the depression-like behaviour. This has implications for the current use of clinical interventions for patients with symptoms of both anxiety and depression. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. Lack of the matricellular protein SPARC (secreted protein, acidic and rich in cysteine attenuates liver fibrogenesis in mice.

    Directory of Open Access Journals (Sweden)

    Catalina Atorrasagasti

    Full Text Available INTRODUCTION: Secreted Protein, Acidic and Rich in Cysteine (SPARC is a matricellular protein involved in many biological processes and found over-expressed in cirrhotic livers. By mean of a genetic approach we herein provide evidence from different in vivo liver disease models suggesting a profibrogenic role for SPARC. METHODS: Two in vivo models of liver fibrosis, based on TAA administration and bile duct ligation, were developed on SPARC wild-type (SPARC(+/+ and knock-out (SPARC(-/- mice. Hepatic SPARC expression was analyzed by qPCR. Fibrosis was assessed by Sirius Red staining, and the maturation state of collagen fibers was analyzed using polarized light. Necroinflammatory activity was evaluated by applying the Knodell score and liver inflammatory infiltration was characterized by immunohistochemistry. Hepatic stellate cell activation was assessed by α-SMA immunohistochemistry. In addition, pro-fibrogenic genes and inflammatory cytokines were measured by qPCR and/or ELISA. Liver gene expression profile was analyzed in SPARC(-/- and SPARC(+/+ mice using Affymetrix Mouse Gene ST 1.0 array. RESULTS: SPARC expression was found induced in fibrotic livers of mouse and human. SPARC(-/- mice showed a reduction in the degree of inflammation, mainly CD4+ cells, and fibrosis. Consistently, collagen deposits and mRNA expression levels were decreased in SPARC(-/- mice when compared to SPARC(+/+ mice; in addition, MMP-2 expression was increased in SPARC(-/- mice. A reduction in the number of activated myofibroblasts was observed. Moreover, TGF-β1 expression levels were down-regulated in the liver as well as in the serum of TAA-treated knock-out animals. Ingenuity Pathway Analysis (IPA analysis suggested several gene networks which might involve protective mechanisms of SPARC deficiency against liver fibrogenesis and a better established machinery to repair DNA and detoxify from external chemical stimuli. CONCLUSIONS: Overall our data suggest that

  20. Lack of effect on the chromosomal non-disjunction in aged female mice after low dose x-irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Strausmanis, R; Hendrikson, I B; Holmberg, M; Roennbaeck, C [Research Inst. of National Defence, Sundbyberg (Sweden). Dept. 4

    1978-02-01

    Karyotypes were determined in 1064 embryos of aged C57/BL mothers. The virgin female mice were irradiated with 0, 4, 8 or 16 R of X-rays, respectively, and placed with young untreated males 5 days after irradiation. 10.5-days old embryos were recovered from the uterus. Aneuploid embryos classified as alive (heart beats observed at the dissection) were 1 monosomic in the control group (496 embryos) and 2 trisomics in the irradiated group (568 embryos). The number of aneuploid embryos classified as dead was 4 trisomic cases in the control group and 3 trisomics in the irradiated group. The data indicate that trisomic embryos are not uncommon in the mouse but are eliminated in post-implantation death. In contrast to the results of Yamamoto et al. the present data do not demonstrate an increased frequency of chromosome abnormalities in embryos of aged mice X-irradiated before mating as compared to non-irradiated ones.

  1. Lack of effect on the chromosomal non-disjunction in aged female mice after low dose x-irradiation

    International Nuclear Information System (INIS)

    Strausmanis, R.; Hendrikson, I.-B.; Holmberg, M.; Roennbaeck, C.

    1978-01-01

    Karyotypes were determined in 1064 embryos of aged C57/BL mothers. The virgin female mice were irradiated with 0, 4, 8 or 16 R of X-rays, respectively, and placed with young untreated males 5 days after irradiation. 10.5-days old embryos were recovered from the uterus. Aneuploid embryos classified as alive (heart beats observed at the dissection) were 1 monosomic in the control group (496 embryos) and 2 trisomics in the irradiated group (568 embryos). The number of aneuploid embryos classified as dead was 4 trisomic cases in the control group and 3 trisomics in the irradiated group. The data indicate that trisomic embryos are not uncommon in the mouse but are eliminated in post-implantation death. In contrast to the results of Yamamoto et al. the present data do not demonstrate an increased frequency of chromosome abnormalities in embryos of aged mice X-irradiated before mating as compared to non-irradiated ones

  2. Acute heat-evoked temperature sensation is impaired but not abolished in mice lacking TRPV1 and TRPV3 channels.

    Science.gov (United States)

    Marics, Irène; Malapert, Pascale; Reynders, Ana; Gaillard, Stéphane; Moqrich, Aziz

    2014-01-01

    The discovery of heat-sensitive Transient Receptor Potential Vanilloid ion channels (ThermoTRPVs) greatly advanced our molecular understanding of acute and injury-evoked heat temperature sensation. ThermoTRPV channels are activated by partially overlapping temperatures ranging from warm to supra-threshold noxious heat. TRPV1 is activated by noxious heat temperature whereas TRPV3 can be activated by warm as well as noxious heat temperatures. Loss-of-function studies in single TRPV1 and TRPV3 knock-out mice have shown that heat temperature sensation is not completely abolished suggesting functional redundancies among these two channels and highlighting the need of a detailed analysis of TRPV1::TRPV3 double knock-out mice (V1V3dKO) which is hampered by the close proximity of the loci expressing the two channels. Here we describe the generation of a novel mouse model in which trpv1 and trpv3 genes have been inactivated using bacterial artificial chromosome (BAC)-based homologous recombination in embryonic stem cells. In these mice, using classical thermosensory tests such hot plate, tail flick and the thermotaxis gradient paradigms, we confirm that TRPV1 is the master channel for sensing noxious heat temperatures and identify a cooperative role of TRPV1 and TRPV3 for sensing a well-defined window of acute moderate heat temperature. Using the dynamic hot plate assay, we unravel an intriguing and unexpected pronounced escape behavior in TRPV1 knock-out mice that was attenuated in the V1V3dKO. Together, and in agreement with the temperature activation overlap between TRPV1 and TRPV3 channels, our data provide in vivo evidence of a cooperative role between skin-derived TRPV3 and primary sensory neurons-enriched TRPV1 in modulation of moderate and noxious heat temperature sensation and suggest that other mechanisms are required for heat temperature sensation.

  3. Alterations in Brain Inflammation, Synaptic Proteins, and Adult Hippocampal Neurogenesis during Epileptogenesis in Mice Lacking Synapsin2.

    Directory of Open Access Journals (Sweden)

    Deepti Chugh

    Full Text Available Synapsins are pre-synaptic vesicle-associated proteins linked to the pathogenesis of epilepsy through genetic association studies in humans. Deletion of synapsins causes an excitatory/inhibitory imbalance, exemplified by the epileptic phenotype of synapsin knockout mice. These mice develop handling-induced tonic-clonic seizures starting at the age of about 3 months. Hence, they provide an opportunity to study epileptogenic alterations in a temporally controlled manner. Here, we evaluated brain inflammation, synaptic protein expression, and adult hippocampal neurogenesis in the epileptogenic (1 and 2 months of age and tonic-clonic (3.5-4 months phase of synapsin 2 knockout mice using immunohistochemical and biochemical assays. In the epileptogenic phase, region-specific microglial activation was evident, accompanied by an increase in the chemokine receptor CX3CR1, interleukin-6, and tumor necrosis factor-α, and a decrease in chemokine keratinocyte chemoattractant/ growth-related oncogene. Both post-synaptic density-95 and gephyrin, scaffolding proteins at excitatory and inhibitory synapses, respectively, showed a significant up-regulation primarily in the cortex. Furthermore, we observed an increase in the inhibitory adhesion molecules neuroligin-2 and neurofascin and potassium chloride co-transporter KCC2. Decreased expression of γ-aminobutyric acid receptor-δ subunit and cholecystokinin was also evident. Surprisingly, hippocampal neurogenesis was reduced in the epileptogenic phase. Taken together, we report molecular alterations in brain inflammation and excitatory/inhibitory balance that could serve as potential targets for therapeutics and diagnostic biomarkers. In addition, the regional differences in brain inflammation and synaptic protein expression indicate an epileptogenic zone from where the generalized seizures in synapsin 2 knockout mice may be initiated or spread.

  4. Expression of GAD67 and Dlx5 in the taste buds of mice genetically lacking Mash1.

    Science.gov (United States)

    Kito-Shingaki, Ayae; Seta, Yuji; Toyono, Takashi; Kataoka, Shinji; Kakinoki, Yasuaki; Yanagawa, Yuchio; Toyoshima, Kuniaki

    2014-06-01

    It has been reported that a subset of type III taste cells express glutamate decarboxylase (GAD)67, which is a molecule that synthesizes gamma-aminobutyric acid (GABA), and that Mash1 could be a potential regulator of the development of GABAnergic neurons via Dlx transcription factors in the central nervous system. In this study, we investigated the expression of GAD67 and Dlx in the embryonic taste buds of the soft palate and circumvallate papilla using Mash1 knockout (KO)/GAD67-GFP knock-in mice. In the wild-type animal, a subset of type III taste cells contained GAD67 in the taste buds of the soft palate and the developing circumvallate papilla, whereas GAD67-expressing taste bud cells were missing from Mash1 KO mice. A subset of type III cells expressed mRNA for Dlx5 in the wild-type animals, whereas Dlx5-expressing cells were not evident in the apical part of the circumvallate papilla and taste buds in the soft palate of Mash1 KO mice. Our results suggest that Mash1 is required for the expression of GAD67 and Dlx5 in taste bud cells. © The Author 2014. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  5. Lack of significant metabolic abnormalities in mice with liver-specific disruption of 11β-hydroxysteroid dehydrogenase type 1.

    LENUS (Irish Health Repository)

    Lavery, Gareth G

    2012-07-01

    Glucocorticoids (GC) are implicated in the development of metabolic syndrome, and patients with GC excess share many clinical features, such as central obesity and glucose intolerance. In patients with obesity or type 2 diabetes, systemic GC concentrations seem to be invariably normal. Tissue GC concentrations determined by the hypothalamic-pituitary-adrenal (HPA) axis and local cortisol (corticosterone in mice) regeneration from cortisone (11-dehydrocorticosterone in mice) by the 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) enzyme, principally expressed in the liver. Transgenic mice have demonstrated the importance of 11β-HSD1 in mediating aspects of the metabolic syndrome, as well as HPA axis control. In order to address the primacy of hepatic 11β-HSD1 in regulating metabolism and the HPA axis, we have generated liver-specific 11β-HSD1 knockout (LKO) mice, assessed biomarkers of GC metabolism, and examined responses to high-fat feeding. LKO mice were able to regenerate cortisol from cortisone to 40% of control and had no discernible difference in a urinary metabolite marker of 11β-HSD1 activity. Although circulating corticosterone was unaltered, adrenal size was increased, indicative of chronic HPA stimulation. There was a mild improvement in glucose tolerance but with insulin sensitivity largely unaffected. Adiposity and body weight were unaffected as were aspects of hepatic lipid homeostasis, triglyceride accumulation, and serum lipids. Additionally, no changes in the expression of genes involved in glucose or lipid homeostasis were observed. Liver-specific deletion of 11β-HSD1 reduces corticosterone regeneration and may be important for setting aspects of HPA axis tone, without impacting upon urinary steroid metabolite profile. These discordant data have significant implications for the use of these biomarkers of 11β-HSD1 activity in clinical studies. The paucity of metabolic abnormalities in LKO points to important compensatory effects by HPA

  6. Mice lacking the conserved transcription factor Grainyhead-like 3 (Grhl3) display increased apposition of the frontal and parietal bones during embryonic development.

    Science.gov (United States)

    Goldie, Stephen J; Arhatari, Benedicta D; Anderson, Peter; Auden, Alana; Partridge, Darren D; Jane, Stephen M; Dworkin, Sebastian

    2016-10-18

    Increased apposition of the frontal and parietal bones of the skull during embryogenesis may be a risk factor for the subsequent development of premature skull fusion, or craniosynostosis. Human craniosynostosis is a prevalent, and often serious embryological and neonatal pathology. Other than known mutations in a small number of contributing genes, the aetiology of craniosynostosis is largely unknown. Therefore, the identification of novel genes which contribute to normal skull patterning, morphology and premature suture apposition is imperative, in order to fully understand the genetic regulation of cranial development. Using advanced imaging techniques and quantitative measurement, we show that genetic deletion of the highly-conserved transcription factor Grainyhead-like 3 (Grhl3) in mice (Grhl3 -/- ) leads to decreased skull size, aberrant skull morphology and premature apposition of the coronal sutures during embryogenesis. Furthermore, Grhl3 -/- mice also present with premature collagen deposition and osteoblast alignment at the sutures, and the physical interaction between the developing skull, and outermost covering of the brain (the dura mater), as well as the overlying dermis and subcutaneous tissue, appears compromised in embryos lacking Grhl3. Although Grhl3 -/- mice die at birth, we investigated skull morphology and size in adult animals lacking one Grhl3 allele (heterozygous; Grhl3 +/- ), which are viable and fertile. We found that these adult mice also present with a smaller cranial cavity, suggestive of post-natal haploinsufficiency in the context of cranial development. Our findings show that our Grhl3 mice present with increased apposition of the frontal and parietal bones, suggesting that Grhl3 may be involved in the developmental pathogenesis of craniosynostosis.

  7. Variations of L- and D-amino acid levels in the brain of wild-type and mutant mice lacking D-amino acid oxidase activity.

    Science.gov (United States)

    Du, Siqi; Wang, Yadi; Weatherly, Choyce A; Holden, Kylie; Armstrong, Daniel W

    2018-05-01

    D-amino acids are now recognized to be widely present in organisms and play essential roles in biological processes. Some D-amino acids are metabolized by D-amino acid oxidase (DAO), while D-Asp and D-Glu are metabolized by D-aspartate oxidase (DDO). In this study, levels of 22 amino acids and the enantiomeric compositions of the 19 chiral proteogenic entities have been determined in the whole brain of wild-type ddY mice (ddY/DAO +/+ ), mutant mice lacking DAO activity (ddY/DAO -/- ), and the heterozygous mice (ddY/DAO +/- ) using high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). No significant differences were observed for L-amino acid levels among the three strains except for L-Trp which was markedly elevated in the DAO +/- and DAO -/- mice. The question arises as to whether this is an unknown effect of DAO inactivity. The three highest levels of L-amino acids were L-Glu, L-Asp, and L-Gln in all the three strains. The lowest L-amino acid level was L-Cys in ddY/DAO +/- and ddY/DAO -/- mice, while L-Trp showed the lowest level in ddY/DAO +/+ mice. The highest concentration of D-amino acid was found to be D-Ser, which also had the highest % D value (~ 25%). D-Glu had the lowest % D value (~ 0.01%) in all the three strains. Significant differences of D-Leu, D-Ala, D-Ser, D-Arg, and D-Ile were observed in ddY/DAO +/- and ddY/DAO -/- mice compared to ddY/DAO +/+ mice. This work provides the most complete baseline analysis of L- and D-amino acids in the brains of ddY/DAO +/+ , ddY/DAO +/- , and ddY/DAO -/- mice yet reported. It also provides the most effective and efficient analytical approach for measuring these analytes in biological samples. This study provides fundamental information on the role of DAO in the brain and may be relevant for future development involving novel drugs for DAO regulation.

  8. Pancreatic Ductal Adenocarcinoma (PDA) mice lacking Mucin 1 have a profound defect in tumor growth and metastasis

    Science.gov (United States)

    Besmer, Dahlia M.; Curry, Jennifer M.; Roy, Lopamudra D.; Tinder, Teresa L.; Sahraei, Mahnaz; Schettini, Jorge; Hwang, Sun-Il; Lee, Yong Y.; Gendler, Sandra J.; Mukherjee, Pinku

    2011-01-01

    MUC1 is over expressed and aberrantly glycosolated in >60% of pancreatic ductal adenocarcinomas. The functional role of MUC1 in pancreatic cancer has yet to be fully elucidated due to a dearth of appropriate models. In the present study, we have generated mouse models that spontaneously develop pancreatic ductal adenocarcinoma (KC), which are either Muc1-null (KCKO) or express human MUC1 (KCM). We show that KCKO mice have significantly slower tumor progression and rates of secondary metastasis, compared to both KC and KCM. Cell lines derived from KCKO tumors have significantly lower tumorigenic capacity compared to cells from KCM tumors. Therefore, mice with KCKO tumors had a significant survival benefit compared to mice with KCM tumors. In vitro, KCKO cells have reduced proliferation and invasion and failed to respond to epidermal growth factor (EGF), platelet-derived growth factor (PDGF), or matrix metalloproteinase-9 (MMP9). Further, significantly fewer KCKO cells entered the G2M phase of the cell cycle compared to the KCM cells. Proteomics and western blotting analysis revealed a complete loss of cdc-25c expression, phosphorylation of MAPK, as well as a significant decrease in Nestin and Tubulin α-2 chain expression in KCKO cells. Treatment with a MEK1/2 inhibitor, U0126, abrogated the enhanced proliferation of the KCM cells but had minimal effect on KCKO cells, suggesting that MUC1 is necessary for MAPK activity and oncogenic signaling. This is the first study to utilize a Muc1-null PDA mouse in order to fully elucidate the oncogenic role of MUC1, both in vivo and in vitro. PMID:21558393

  9. B-1a transitional cells are phenotypically distinct and are lacking in mice deficient in IκBNS

    Science.gov (United States)

    Pedersen, Gabriel K.; Àdori, Monika; Khoenkhoen, Sharesta; Dosenovic, Pia; Beutler, Bruce; Karlsson Hedestam, Gunilla B.

    2014-01-01

    B-1 cells mediate early protection against infection by responding to T cell-independent (TI) antigens found on the surface of various pathogens. Mice with impaired expression of the atypical IκB protein IκBNS have markedly reduced frequencies of B-1 cells. We used a mouse strain with dysfunctional IκBNS derived from an N-ethyl-N-nitrosourea (ENU) screen, named bumble, to investigate the point in the development of B-1 cells where IκBNS is required. The presence of wild-type (wt) peritoneal cells in mixed wt/bumble chimeras did not rescue the development of bumble B-1 cells, but wt peritoneal cells transferred to bumble mice restored natural IgM levels and response to TI antigens. The bumble and wt mice displayed similar levels of fetal liver B-1 progenitors and splenic neonatal transitional B (TrB) cells, both of which were previously shown to give rise to B-1 cells. Interestingly, we found that a subset of wt neonatal TrB cells expressed common B-1a markers (TrB-1a) and that this cell population was absent in the bumble neonatal spleen. Sorted TrB-1a (CD93+IgM+CD5+) cells exclusively generated B-1a cells when adoptively transferred, whereas sorted CD93+IgM+CD5− cells gave rise to B-2 cells and, to a lesser extent, B-1b and B-1a cells. This study identifies a phenotypically distinct splenic population of TrB-1a cells and establishes that the development of B-1a cells is blocked before this stage in the absence of IκBNS. PMID:25228759

  10. Dwarfism in Mice Lacking Collagen-binding Integrins α2β1 and α11β1 Is Caused by Severely Diminished IGF-1 Levels*

    Science.gov (United States)

    Blumbach, Katrin; Niehoff, Anja; Belgardt, Bengt F.; Ehlen, Harald W. A.; Schmitz, Markus; Hallinger, Ralf; Schulz, Jan-Niklas; Brüning, Jens C.; Krieg, Thomas; Schubert, Markus; Gullberg, Donald; Eckes, Beate

    2012-01-01

    Mice with a combined deficiency in the α2β1 and α11β1 integrins lack the major receptors for collagen I. These mutants are born with inconspicuous differences in size but develop dwarfism within the first 4 weeks of life. Dwarfism correlates with shorter, less mineralized and functionally weaker bones that do not result from growth plate abnormalities or osteoblast dysfunction. Besides skeletal dwarfism, internal organs are correspondingly smaller, indicating proportional dwarfism and suggesting a systemic cause for the overall size reduction. In accordance with a critical role of insulin-like growth factor (IGF)-1 in growth control and bone mineralization, circulating IGF-1 levels in the sera of mice lacking either α2β1 or α11β1 or both integrins were sharply reduced by 39%, 64%, or 81% of normal levels, respectively. Low hepatic IGF-1 production resulted from diminished growth hormone-releasing hormone expression in the hypothalamus and, subsequently, reduced growth hormone expression in the pituitary glands of these mice. These findings point out a novel role of collagen-binding integrin receptors in the control of growth hormone/IGF-1-dependent biological activities. Thus, coupling hormone secretion to extracellular matrix signaling via integrins represents a novel concept in the control of endocrine homeostasis. PMID:22210772

  11. Dwarfism in mice lacking collagen-binding integrins α2β1 and α11β1 is caused by severely diminished IGF-1 levels.

    Science.gov (United States)

    Blumbach, Katrin; Niehoff, Anja; Belgardt, Bengt F; Ehlen, Harald W A; Schmitz, Markus; Hallinger, Ralf; Schulz, Jan-Niklas; Brüning, Jens C; Krieg, Thomas; Schubert, Markus; Gullberg, Donald; Eckes, Beate

    2012-02-24

    Mice with a combined deficiency in the α2β1 and α11β1 integrins lack the major receptors for collagen I. These mutants are born with inconspicuous differences in size but develop dwarfism within the first 4 weeks of life. Dwarfism correlates with shorter, less mineralized and functionally weaker bones that do not result from growth plate abnormalities or osteoblast dysfunction. Besides skeletal dwarfism, internal organs are correspondingly smaller, indicating proportional dwarfism and suggesting a systemic cause for the overall size reduction. In accordance with a critical role of insulin-like growth factor (IGF)-1 in growth control and bone mineralization, circulating IGF-1 levels in the sera of mice lacking either α2β1 or α11β1 or both integrins were sharply reduced by 39%, 64%, or 81% of normal levels, respectively. Low hepatic IGF-1 production resulted from diminished growth hormone-releasing hormone expression in the hypothalamus and, subsequently, reduced growth hormone expression in the pituitary glands of these mice. These findings point out a novel role of collagen-binding integrin receptors in the control of growth hormone/IGF-1-dependent biological activities. Thus, coupling hormone secretion to extracellular matrix signaling via integrins represents a novel concept in the control of endocrine homeostasis.

  12. Characterization of NGF, trkANGFR, and p75NTR in Retina of Mice Lacking Reelin Glycoprotein

    Directory of Open Access Journals (Sweden)

    Bijorn Omar Balzamino

    2014-01-01

    Full Text Available Both Reelin and Nerve Growth Factor (NGF exert crucial roles in retinal development. Retinogenesis is severely impaired in E-reeler mice, a model of Reelin deficiency showing specific Green Fluorescent Protein expression in Rod Bipolar Cells (RBCs. Since no data are available on Reelin and NGF cross-talk, NGF and trkANGFR/ p75NTR expression was investigated in retinas from E-reeler versus control mice, by confocal microscopy, Western blotting, and real time PCR analysis. A scattered increase of NGF protein was observed in the Ganglion Cell Layer and more pronounced in the Inner Nuclear Layer (INL. A selective increase of p75NTR was detected in most of RBCs and in other cell subtypes of INL. On the contrary, a slight trend towards a decrease was detected for trkANGFR, albeit not significant. Confocal data were validated by Western blot and real time PCR. Finally, the decreased trkANGFR/ p75NTR ratio, representative of p75NTR increase, significantly correlated with E-reeler versus E-control. These data indicate that NGF-trkANGFR/ p75NTR is affected in E-reeler retina and that p75NTR might represent the main NGF receptor involved in the process. This first NGF-trkANGFR/ p75NTR characterization suggests that E-reeler might be suitable for exploring Reelin-NGF cross-talk, representing an additional information source in those pathologies characterized by retinal degeneration.

  13. The Lack of Cytotoxic Effect and Radioadaptive Response in Splenocytes of Mice Exposed to Low Level Internal β-Particle Irradiation through Tritiated Drinking Water in Vivo

    Directory of Open Access Journals (Sweden)

    Matthew Flegal

    2013-12-01

    Full Text Available Health effects of tritium, a β-emitter and a by-product of the nuclear industry, is a subject of significant controversy. This mouse in vivo study was undertaken to monitor biological effects of low level tritium exposure. Mice were exposed to tritiated drinking water (HTO at 10 KBq/L, 1 MBq/L and 20 MBq/L concentrations for one month. The treatment did not result in a significant increase of apoptosis in splenocytes. To examine if this low level tritium exposure alters radiosensitivity, the extracted splenocytes were challenged in vitro with 2 Gy γ-radiation, and apoptotic responses at 1 and 24 h were measured. No alterations in the radiosensitivity were detected in cells from mice exposed to tritium compared to sham-treated mice. In contrast, low dose γ-irradiation at 20 or 100 mGy, resulted in a significant increase in resistance to apoptotic cell death after 2 Gy irradiation; an indication of the radioadaptive response. Overall, our data suggest that low concentrations of tritium given to mice as HTO in drinking water do not exert cytotoxic effect in splenocytes, nor do they change cellular sensitivity to additional high dose γ-radiation. The latter may be considered as the lack of a radioadaptive response, typically observed after low dose γ-irradiation.

  14. Cytochrome P450 humanised mice

    OpenAIRE

    Gonzalez Frank J

    2004-01-01

    Abstract Humans are exposed to countless foreign compounds, typically referred to as xenobiotics. These can include clinically used drugs, environmental pollutants, food additives, pesticides, herbicides and even natural plant compounds. Xenobiotics are metabolised primarily in the liver, but also in the gut and other organs, to derivatives that are more easily eliminated from the body. In some cases, however, a compound is converted to an electrophile that can cause cell toxicity and transfo...

  15. Plasma biomarkers of liver injury and inflammation demonstrate a lack of apoptosis during obstructive cholestasis in mice

    Energy Technology Data Exchange (ETDEWEB)

    Woolbright, Benjamin L. [Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, Kansas City, KS (United States); Antoine, Daniel J.; Jenkins, Rosalind E. [MRC Centre for Drug Safety Science, Department of Molecular and Clinical Pharmacology, Institute of Translational Medicine, University of Liverpool, Liverpool (United Kingdom); Bajt, Mary Lynn [Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, Kansas City, KS (United States); Park, B. Kevin [MRC Centre for Drug Safety Science, Department of Molecular and Clinical Pharmacology, Institute of Translational Medicine, University of Liverpool, Liverpool (United Kingdom); Jaeschke, Hartmut, E-mail: hjaeschke@kumc.edu [Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, Kansas City, KS (United States)

    2013-12-15

    Cholestasis is a pathological common component of numerous liver diseases that results in hepatotoxicity, inflammation, and cirrhosis when untreated. While the predominant hypothesis in cholestatic liver injury remains hepatocyte apoptosis due to direct toxicity of hydrophobic bile acid exposure, recent work suggests that the injury occurs through inflammatory necrosis. In order to resolve this controversy, we used novel plasma biomarkers to assess the mechanisms of cell death during early cholestatic liver injury. C57Bl/6 mice underwent bile duct ligation (BDL) for 6–72 h, or sham operation. Another group of mice were given D-galactosamine and endotoxin as a positive control for apoptosis and inflammatory necrosis. Plasma levels of full length cytokeratin-18 (FL-K18), microRNA-122 (miR-122) and high mobility group box-1 protein (HMGB1) increased progressively after BDL with peak levels observed after 48 h. These results indicate extensive cell necrosis after BDL, which is supported by the time course of plasma alanine aminotransferase activities and histology. In contrast, plasma caspase-3 activity, cleaved caspase-3 protein and caspase-cleaved cytokeratin-18 fragments (cK18) were not elevated at any time during BDL suggesting the absence of apoptosis. In contrast, all plasma biomarkers of necrosis and apoptosis were elevated 6 h after Gal/End treatment. In addition, acetylated HMGB1, a marker for macrophage and monocyte activation, was increased as early as 12 h but mainly at 48–72 h. However, progressive neutrophil accumulation in the area of necrosis started at 6 h after BDL. In conclusion, these data indicate that early cholestatic liver injury in mice is an inflammatory event, and occurs through necrosis with little evidence for apoptosis. - Highlights: • The mechanism of cell death during cholestasis remains a controversial topic. • Plasma biomarkers offer new insight into cell death after bile duct ligation. • Cytokeratin-18, microRNA-122 and HMGB

  16. Plasma biomarkers of liver injury and inflammation demonstrate a lack of apoptosis during obstructive cholestasis in mice

    International Nuclear Information System (INIS)

    Woolbright, Benjamin L.; Antoine, Daniel J.; Jenkins, Rosalind E.; Bajt, Mary Lynn; Park, B. Kevin; Jaeschke, Hartmut

    2013-01-01

    Cholestasis is a pathological common component of numerous liver diseases that results in hepatotoxicity, inflammation, and cirrhosis when untreated. While the predominant hypothesis in cholestatic liver injury remains hepatocyte apoptosis due to direct toxicity of hydrophobic bile acid exposure, recent work suggests that the injury occurs through inflammatory necrosis. In order to resolve this controversy, we used novel plasma biomarkers to assess the mechanisms of cell death during early cholestatic liver injury. C57Bl/6 mice underwent bile duct ligation (BDL) for 6–72 h, or sham operation. Another group of mice were given D-galactosamine and endotoxin as a positive control for apoptosis and inflammatory necrosis. Plasma levels of full length cytokeratin-18 (FL-K18), microRNA-122 (miR-122) and high mobility group box-1 protein (HMGB1) increased progressively after BDL with peak levels observed after 48 h. These results indicate extensive cell necrosis after BDL, which is supported by the time course of plasma alanine aminotransferase activities and histology. In contrast, plasma caspase-3 activity, cleaved caspase-3 protein and caspase-cleaved cytokeratin-18 fragments (cK18) were not elevated at any time during BDL suggesting the absence of apoptosis. In contrast, all plasma biomarkers of necrosis and apoptosis were elevated 6 h after Gal/End treatment. In addition, acetylated HMGB1, a marker for macrophage and monocyte activation, was increased as early as 12 h but mainly at 48–72 h. However, progressive neutrophil accumulation in the area of necrosis started at 6 h after BDL. In conclusion, these data indicate that early cholestatic liver injury in mice is an inflammatory event, and occurs through necrosis with little evidence for apoptosis. - Highlights: • The mechanism of cell death during cholestasis remains a controversial topic. • Plasma biomarkers offer new insight into cell death after bile duct ligation. • Cytokeratin-18, microRNA-122 and HMGB

  17. Normal hematopoiesis and lack of β-catenin activation in osteoblasts of patients and mice harboring Lrp5 gain-of-function mutations.

    Science.gov (United States)

    Galán-Díez, Marta; Isa, Adiba; Ponzetti, Marco; Nielsen, Morten Frost; Kassem, Moustapha; Kousteni, Stavroula

    2016-03-01

    Osteoblasts are emerging regulators of myeloid malignancies since genetic alterations in them, such as constitutive activation of β-catenin, instigate their appearance. The LDL receptor-related protein 5 (LRP5), initially proposed to be a co-receptor for Wnt proteins, in fact favors bone formation by suppressing gut-serotonin synthesis. This function of Lrp5 occurring in the gut is independent of β-catenin activation in osteoblasts. However, it is unknown whether Lrp5 can act directly in osteoblast to influence other functions that require β-catenin signaling, particularly, the deregulation of hematopoiesis and leukemogenic properties of β-catenin activation in osteoblasts, that lead to development of acute myeloid leukemia (AML). Using mice with gain-of-function (GOF) Lrp5 alleles (Lrp5(A214V)) that recapitulate the human high bone mass (HBM) phenotype, as well as patients with the T253I HBM Lrp5 mutation, we show here that Lrp5 GOF mutations in both humans and mice do not activate β-catenin signaling in osteoblasts. Consistent with a lack of β-catenin activation in their osteoblasts, Lrp5(A214V) mice have normal trilinear hematopoiesis. In contrast to leukemic mice with constitutive activation of β-catenin in osteoblasts (Ctnnb1(CAosb)), accumulation of early myeloid progenitors, a characteristic of AML, myeloid-blasts in blood, and segmented neutrophils or dysplastic megakaryocytes in the bone marrow, are not observed in Lrp5(A214V) mice. Likewise, peripheral blood count analysis in HBM patients showed normal hematopoiesis, normal percentage of myeloid cells, and lack of anemia. We conclude that Lrp5 GOF mutations do not activate β-catenin signaling in osteoblasts. As a result, myeloid lineage differentiation is normal in HBM patients and mice. This article is part of a Special Issue entitled: Tumor Microenvironment Regulation of Cancer Cell Survival, Metastasis, Inflammation, and Immune Surveillance edited by Peter Ruvolo and Gregg L. Semenza. Published

  18. Alteration of structure and function of ATP synthase and cytochrome c oxidase by lack of F-o-a and Cox3 subunits caused by mitochondrial DNA 9205delTA mutation

    Czech Academy of Sciences Publication Activity Database

    Hejzlarová, Kateřina; Kaplanová, Vilma; Nůsková, Hana; Kovářová, Nikola; Ješina, Pavel; Drahota, Zdeněk; Mráček, Tomáš; Seneca, S.; Houštěk, Josef

    2015-01-01

    Roč. 466, č. 3 (2015), s. 601-611 ISSN 0264-6021 R&D Projects: GA ČR(CZ) GAP303/11/0970; GA ČR(CZ) GB14-36804G; GA MŠk(CZ) LL1204; GA ČR(CZ) GAP303/12/1363 Institutional support: RVO:67985823 Keywords : ATP synthase * cytochrome c oxidase * mitochondrial diseases * mtDNA MT-ATP6 mutation * oxidative phosphorylation * threshold effect Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 3.562, year: 2015

  19. Altered Hematopoiesis in Mice Lacking DNA Polymerase μ Is Due to Inefficient Double-Strand Break Repair

    Science.gov (United States)

    Lucas, Daniel; Escudero, Beatriz; Ligos, José Manuel; Segovia, Jose Carlos; Estrada, Juan Camilo; Terrados, Gloria; Blanco, Luis; Samper, Enrique; Bernad, Antonio

    2009-01-01

    Polymerase mu (Polμ) is an error-prone, DNA-directed DNA polymerase that participates in non-homologous end-joining (NHEJ) repair. In vivo, Polμ deficiency results in impaired Vκ-Jκ recombination and altered somatic hypermutation and centroblast development. In Polμ−/− mice, hematopoietic development was defective in several peripheral and bone marrow (BM) cell populations, with about a 40% decrease in BM cell number that affected several hematopoietic lineages. Hematopoietic progenitors were reduced both in number and in expansion potential. The observed phenotype correlates with a reduced efficiency in DNA double-strand break (DSB) repair in hematopoietic tissue. Whole-body γ-irradiation revealed that Polμ also plays a role in DSB repair in non-hematopoietic tissues. Our results show that Polμ function is required for physiological hematopoietic development with an important role in maintaining early progenitor cell homeostasis and genetic stability in hematopoietic and non-hematopoietic tissues. PMID:19229323

  20. Niemann-Pick C1-deficient mice lacking sterol O-acyltransferase 2 have less hepatic cholesterol entrapment and improved liver function.

    Science.gov (United States)

    Lopez, Adam M; Jones, Ryan Dale; Repa, Joyce J; Turley, Stephen D

    2018-06-07

    Cholesteryl esters are generated at multiple sites in the body by sterol O-acyltransferase 1 (SOAT1) or sterol O-acyltransferase 2 (SOAT2) in various cell types, and lecithin cholesterol acyltransferase (LCAT) in plasma. Esterified cholesterol (EC) and triacylglycerol (TAG) contained in lipoproteins cleared from the circulation via receptor-mediated or bulk-phase endocytosis are hydrolyzed by lysosomal acid lipase (LAL) within the late endosomal/lysosomal (E/L) compartment. Then, through the successive actions of Niemann-Pick C2 (NPC2) and Niemann-Pick C1 (NPC1), unesterified cholesterol (UC) is exported from the E/L compartment to the cytosol. Mutations in either NPC1 or NPC2 lead to continuing entrapment of UC in all organs, resulting in multisystem disease which includes hepatic dysfunction and in some cases liver failure. These studies investigated primarily whether elimination of SOAT2 in NPC1-deficient mice impacted hepatic UC sequestration, inflammation, and transaminase activities. Measurements were made in 7 wk-old mice fed a low-cholesterol chow diet or one enriched with cholesterol starting 2 wk before study. In the chow-fed mice, NPC1:SOAT2 double knockouts, compared to their littermates lacking only NPC1, had 20% less liver mass, 28% lower hepatic UC concentrations, and plasma ALT and AST activities that were decreased by 48% and 36%, respectively. mRNA expression levels for several markers of inflammation were all significantly lower in the NPC1 mutants lacking SOAT2. The existence of a new class of potent and selective SOAT2 inhibitors provides an opportunity for exploring if suppression of this enzyme could potentially become an adjunctive therapy for liver disease in NPC1 deficiency.

  1. Severe Extracellular Matrix Abnormalities and Chondrodysplasia in Mice Lacking Collagen Prolyl 4-Hydroxylase Isoenzyme II in Combination with a Reduced Amount of Isoenzyme I.

    Science.gov (United States)

    Aro, Ellinoora; Salo, Antti M; Khatri, Richa; Finnilä, Mikko; Miinalainen, Ilkka; Sormunen, Raija; Pakkanen, Outi; Holster, Tiina; Soininen, Raija; Prein, Carina; Clausen-Schaumann, Hauke; Aszódi, Attila; Tuukkanen, Juha; Kivirikko, Kari I; Schipani, Ernestina; Myllyharju, Johanna

    2015-07-03

    Collagen prolyl 4-hydroxylases (C-P4H-I, C-P4H-II, and C-P4H-III) catalyze formation of 4-hydroxyproline residues required to form triple-helical collagen molecules. Vertebrate C-P4Hs are α2β2 tetramers differing in their catalytic α subunits. C-P4H-I is the major isoenzyme in most cells, and inactivation of its catalytic subunit (P4ha1(-/-)) leads to embryonic lethality in mouse, whereas P4ha1(+/-) mice have no abnormalities. To study the role of C-P4H-II, which predominates in chondrocytes, we generated P4ha2(-/-) mice. Surprisingly, they had no apparent phenotypic abnormalities. To assess possible functional complementarity, we established P4ha1(+/-);P4ha2(-/-) mice. They were smaller than their littermates, had moderate chondrodysplasia, and developed kyphosis. A transient inner cell death phenotype was detected in their developing growth plates. The columnar arrangement of proliferative chondrocytes was impaired, the amount of 4-hydroxyproline and the Tm of collagen II were reduced, and the extracellular matrix was softer in the growth plates of newborn P4ha1(+/-);P4ha2(-/-) mice. No signs of uncompensated ER stress were detected in the mutant growth plate chondrocytes. Some of these defects were also found in P4ha2(-/-) mice, although in a much milder form. Our data show that C-P4H-I can to a large extent compensate for the lack of C-P4H-II in proper endochondral bone development, but their combined partial and complete inactivation, respectively, leads to biomechanically impaired extracellular matrix, moderate chondrodysplasia, and kyphosis. Our mouse data suggest that inactivating mutations in human P4HA2 are not likely to lead to skeletal disorders, and a simultaneous decrease in P4HA1 function would most probably be required to generate such a disease phenotype. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

  2. Not So Giants: Mice Lacking Both Somatostatin and Cortistatin Have High GH Levels but Show No Changes in Growth Rate or IGF-1 Levels.

    Science.gov (United States)

    Pedraza-Arévalo, S; Córdoba-Chacón, J; Pozo-Salas, A I; L-López, F; de Lecea, L; Gahete, M D; Castaño, J P; Luque, R M

    2015-06-01

    Somatostatin (SST) and cortistatin (CORT) are two highly related neuropeptides involved in the regulation of various endocrine secretions. In particular, SST and CORT are two primary negative regulators of GH secretion. Consequently, single SST or CORT knockout mice exhibit elevated GH levels; however, this does not lead to increased IGF-1 levels or somatic growth. This apparent lack of correspondence has been suggested to result from compensatory mechanisms between both peptides. To test this hypothesis, in this study we explored, for the first time, the consequences of simultaneously deleting endogenous SST and CORT by generating a double SST/CORT knockout mouse model and exploring its endocrine and metabolic phenotype. Our results demonstrate that simultaneous deletion of SST and CORT induced a drastic elevation of endogenous GH levels, which, surprisingly, did not lead to changes in growth rate or IGF-1 levels, suggesting the existence of additional factors/systems that, in the absence of endogenous SST and CORT, could counteract GH actions. Notably, elevation in circulating GH levels were not accompanied by changes in pituitary GH expression or by alterations in the expression of its main regulators (GHRH and ghrelin) or their receptors (GHRH receptor, GHS receptor, or SST/CORT receptors) at the hypothalamic or pituitary level. However, although double-SST/CORT knockout male mice exhibited normal glucose and insulin levels, they had improved insulin sensitivity compared with the control mice. Therefore, these results suggest the existence of an intricate interplay among the known (SST/CORT), and likely unknown, inhibitory components of the GH/IGF-1 axis to regulate somatic growth and glucose/insulin homeostasis.

  3. Defective cancellous bone structure and abnormal response to PTH in cortical bone of mice lacking Cx43 cytoplasmic C-terminus domain

    Science.gov (United States)

    Pacheco-Costa, Rafael; Davis, Hannah M.; Sorenson, Chad; Hon, Mary C.; Hassan, Iraj; Reginato, Rejane D.; Allen, Matthew R.; Bellido, Teresita; Plotkin, Lilian I.

    2015-01-01

    Connexin43 (Cx43) forms gap junction channels and hemichannels that allow the communication among osteocytes, osteoblasts, and osteoclasts. Cx43 carboxy-terminal (CT) domain regulates channel opening and intracellular signaling by acting as a scaffold for structural and signaling proteins. To determine the role of Cx43 CT domain in bone, mice in which one allele of full length Cx43 was replaced by a mutant lacking the CT domain (Cx43ΔCT/fl) were studied. Cx43ΔCT/fl mice exhibit lower cancellous bone volume but higher cortical thickness than Cx43fl/fl controls, indicating that the CT domain is involved in normal cancellous bone gain but opposes cortical bone acquisition. Further, Cx43ΔCT is able to exert the functions of full length osteocytic Cx43 on cortical bone geometry and mechanical properties, demonstrating that domains other than the CT are responsible for Cx43 function in cortical bone. In addition, parathyroid hormone (PTH) failed to increase endocortical bone formation or energy to failure, a mechanical property that indicates resistance to fracture, in cortical bone in Cx43ΔCT mice with or without osteocytic full length Cx43. On the other hand, bone mass and bone formation markers were increased by the hormone in all mouse models, regardless of whether full length or Cx43ΔCT were or not expressed. We conclude that Cx43 CT domain is involved in proper bone acquisition; and that Cx43 expression in osteocytes is dispensable for some but not all PTH anabolic actions. PMID:26409319

  4. Premature Aging Phenotype in Mice Lacking High-Affinity Nicotinic Receptors: Region-Specific Changes in Layer V Pyramidal Cell Morphology.

    Science.gov (United States)

    Konsolaki, Eleni; Skaliora, Irini

    2015-08-01

    The mechanisms by which aging leads to alterations in brain structure and cognitive deficits are unclear. Α deficient cholinergic system has been implicated as one of the main factors that could confer a heightened vulnerability to the aging process, and mice lacking high-affinity nicotinic receptors (β2(-/-)) have been proposed as an animal model of accelerated cognitive aging. To date, however, age-related changes in neuronal microanatomy have not been studied in these mice. In the present study, we examine the neuronal structure of yellow fluorescent protein (YFP(+)) layer V neurons in 2 cytoarchitectonically distinct cortical regions in wild-type (WT) and β2(-/-) animals. We find that (1) substantial morphological differences exist between YFP(+) cells of the anterior cingulate cortex (ACC) and primary visual cortex (V1), in both genotypes; (2) in WT animals, ACC cells are more susceptible to aging compared with cells in V1; and (3) β2 deletion is associated with a regionally and temporally specific increase in vulnerability to aging. ACC cells exhibit a prematurely aged phenotype already at 4-6 months, whereas V1 cells are spared in adulthood but strongly affected in old animals. Collectively, our data reveal region-specific synergistic effects of aging and genotype and suggest distinct vulnerabilities in V1 and ACC neurons. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  5. A lack of immune system genes causes loss in high frequency hearing but does not disrupt cochlear synapse maturation in mice.

    Science.gov (United States)

    Calton, Melissa A; Lee, Dasom; Sundaresan, Srividya; Mendus, Diana; Leu, Rose; Wangsawihardja, Felix; Johnson, Kenneth R; Mustapha, Mirna

    2014-01-01

    Early cochlear development is marked by an exuberant outgrowth of neurites that innervate multiple targets. The establishment of mature cochlear neural circuits is, however, dependent on the pruning of inappropriate axons and synaptic connections. Such refinement also occurs in the central nervous system (CNS), and recently, genes ordinarily associated with immune and inflammatory processes have been shown to play roles in synaptic pruning in the brain. These molecules include the major histocompatibility complex class I (MHCI) genes, H2-K(b) and H2-D(b), and the complement cascade gene, C1qa. Since the mechanisms involved in synaptic refinement in the cochlea are not well understood, we investigated whether these immune system genes may be involved in this process and whether they are required for normal hearing function. Here we report that these genes are not necessary for normal synapse formation and refinement in the mouse cochlea. We further demonstrate that C1qa expression is not necessary for normal hearing in mice but the lack of expression of H2-K(b) and H2-D(b) causes hearing impairment. These data underscore the importance of the highly polymorphic family of MHCI genes in hearing in mice and also suggest that factors and mechanisms regulating synaptic refinement in the cochlea may be distinct from those in the CNS.

  6. Dietary antioxidants prevent age-related retinal pigment epithelium actin damage and blindness in mice lacking αvβ5 integrin

    Science.gov (United States)

    Yu, Chia-Chia; Nandrot, Emeline F.; Dun, Ying; Finnemann, Silvia C.

    2011-01-01

    In the aging human eye, oxidative damage and accumulation of pro-oxidant lysosomal lipofuscin cause functional decline of the retinal pigment epithelium (RPE), which contributes to age-related macular degeneration. In mice with an RPE-specific phagocytosis defect due to lack of αvβ5 integrin receptors, RPE accumulation of lipofuscin suggests that the age-related blindness we previously described in this model may also result from oxidative stress. Cellular and molecular targets of oxidative stress in the eye remain poorly understood. Here we identify actin among 4-hydroxynonenal (HNE) adducts formed specifically in β5−/− RPE but not neural retina with age. HNE modification directly correlated with loss of resistance of actin to detergent extraction, suggesting cytoskeletal damage in aging RPE. Dietary enrichment with natural antioxidants grapes or marigold extract containing macular pigments lutein/zeaxanthin was sufficient to prevent HNE-adduct formation, actin solubility, lipofuscin accumulation, and age-related cone and rod photoreceptor dysfunction in β5−/− mice. Acute generation of HNE-adducts directly destabilized actin but not tubulin cytoskeletal elements of RPE cells. These findings identify destabilization of the actin cytoskeleton as a consequence of physiological, sublethal oxidative burden of RPE cells in vivo that is associated with age-related blindness and that can be prevented by consuming an antioxidant-rich diet. PMID:22178979

  7. Comparative metabolism of methacrylonitrile and acrylonitrile to cyanide using cytochrome P4502E1 and microsomal epoxide hydrolase-null mice

    International Nuclear Information System (INIS)

    El Hadri, L.; Chanas, B.; Ghanayem, B.I.

    2005-01-01

    Methacrylonitrile (MAN) and acrylonitrile (AN) are metabolized via glutathione (GSH) conjugation or epoxide formation. We have recently shown that CYP2E1 is essential for AN epoxidation and subsequent cyanide liberation. Current studies were designed to compare the enzymatic basis of MAN vs. AN metabolism to cyanide using wild-type (WT), CYP2E1-, and mEH-null mice. Mice received a single gavage dose of 0.047, 0.095, 0.19, or 0.38 mmol/kg of MAN or AN, and blood cyanide was measured at 1 or 3 h later. Blood cyanide levels in WT mice treated with AN or MAN were dose and time dependent. At equimolar doses, significantly higher levels of cyanide were detected in the blood of MAN- vs. AN-treated mice. Further, while significant reduction in blood cyanide levels occurred in MAN-treated CYP2E1-null vs. WT mice, AN metabolism to cyanide was largely abolished in CYP2E1-null mice. Pretreatment of mice with 1-aminobenzotriazole (ABT, CYP inhibitor) demonstrated that CYPs other than CYP2E1 also contribute to MAN metabolism to cyanide. Blood cyanide levels in mEH-null mice treated with aliphatic nitriles are generally lower than levels in similarly treated WT mice. Western blot analysis showed that expression of sEH was greater in male vs. female mice. The role of various epoxide hydrolases (EHs) in the production of cyanide from aliphatic nitriles is apparently structure and dose dependent. Regardless of genotype, significantly higher levels of cyanide were measured in the blood of male vs. female mice treated with MAN or AN. In conclusion, these data showed that (1) at equimolar doses, higher blood cyanide levels were detected in mice treated with MAN vs. AN; (2) while CYP2E1 is the only enzyme responsible for AN metabolism to cyanide, other CYPs also contribute to MAN metabolism; and (3) significantly higher levels of cyanide were measured in the blood of male vs. female treated with either nitrile. Higher blood cyanide levels in male vs. female mice and in MAN- vs. AN

  8. Novel Hg2+-Induced Nephropathy in Rats and Mice Lacking Mrp2: Evidence of Axial Heterogeneity in the Handling of Hg2+ Along the Proximal Tubule

    Science.gov (United States)

    Zalups, Rudolfs K.; Joshee, Lucy; Bridges, Christy C.

    2014-01-01

    The role of the multi-resistance protein 2 (Mrp2) in the nephropathy induced by inorganic mercuric mercury (Hg2+) was studied in rats (TR−) and mice (Mrp2−/−), which lack functional Mrp2, and control animals. Animals were exposed to nephrotoxic doses of HgCl2. Forty-eight or 24 hours after exposure, tissues were harvested and analyzed for Hg content and markers of injury. Histological analyses revealed that the proximal tubular segments affected pathologically by Hg2+ were significantly different between Mrp2-deficient animals and controls. In the absence of Mrp2, cellular injury localized almost exclusively in proximal tubular segments in the subcapsular (S1) to midcortical regions (early S2) of the kidney. In control animals, cellular death occurred mainly in the proximal tubular segments in the inner cortex (late S2) and outer stripe of the outer medulla (S3). These differences in renal pathology indicate that axial heterogeneity exists along the proximal tubule with respect to how mercuric ions are handled. Total renal and hepatic accumulation of mercury was also greater in animals lacking Mrp2 than in controls, indicating that Mrp2 normally plays a significant role in eliminating mercuric ions from within proximal tubular cells and hepatocytes. Analyses of plasma creatinine, BUN, and renal expression of Kim-1 and Ngal tend to support the severity of the nephropathies detected histologically. Collectively, our findings indicate that a fraction of mercuric ions is normally secreted by Mrp2 in early portions of proximal tubules into the lumen and then is absorbed downstream in straight portions, where mercuric species typically induce toxic effects. PMID:25145654

  9. Purple sweet potato color alleviates D-galactose-induced brain aging in old mice by promoting survival of neurons via PI3K pathway and inhibiting cytochrome C-mediated apoptosis.

    Science.gov (United States)

    Lu, Jun; Wu, Dong-mei; Zheng, Yuan-lin; Hu, Bin; Zhang, Zi-feng

    2010-05-01

    Purple sweet potato color (PSPC), a class of naturally occurring anthocyanins, protects brain function against oxidative stress induced by D-galactose (D-gal) (Sigma-Aldrich, St. Louis, MO, USA). Our data showed that PSPC enhanced open-field activity, decreased step-through latency, and improved spatial learning and memory ability in D-gal-treated old mice by decreasing advanced glycation end-products' (AGEs) formation and the AGE receptor (RAGE) expression, and by elevating Cu,Zn-superoxide dismutase (Cu,Zn-SOD) (Sigma-Aldrich) and catalase (CAT) expression and activity. Cleavage of caspase-3 and increased terminal deoxynucleotidyl transferase (TdT)-mediated deoxyuridine triphosphate (dUTP) nick-end-labeling (TUNEL)-positive cells in D-gal-treated old mice were inhibited by PSPC, which might be attributed to its antioxidant property. PSPC also suppressed the activation of c-Jun NH(2)-terminal kinase (JNK) and the release of cytochrome c from mitochondria that counteracted the onset of neuronal apoptosis in D-gal-treated old mice. Furthermore, it was demonstrated that phosphoinositide 3-kinase (PI3K) activation was required for PSPC to promote the neuronal survival accompanied with phosphorylation and activation of Akt and p44/42 mitogen-activated protein kinase (MAPK) by using PI3K inhibitor LY294002 (Cell Signaling Technology, Inc., Beverly, MA, USA), implicating a neuronal survival mechanism. The present results suggest that neuronal survival promoted by PSPC may be a potentially effective method to enhance resistance of neurons to age-related disease.

  10. The effect of alcohol and hydrogen peroxide on liver hepcidin gene expression in mice lacking antioxidant enzymes, glutathione peroxidase-1 or catalase.

    Science.gov (United States)

    Harrison-Findik, Duygu Dee; Lu, Sizhao

    2015-05-06

    This study investigates the regulation of hepcidin, the key iron-regulatory molecule, by alcohol and hydrogen peroxide (H2O2) in glutathione peroxidase-1 (gpx-1(-/-)) and catalase (catalase(-/-)) knockout mice. For alcohol studies, 10% ethanol was administered in the drinking water for 7 days. Gpx-1(-/-) displayed significantly higher hepatic H2O2 levels than catalase(-/-) compared to wild-type mice, as measured by 2'-7'-dichlorodihydrofluorescein diacetate (DCFH-DA). The basal level of liver hepcidin expression was attenuated in gpx-1(-/-) mice. Alcohol increased H2O2 production in catalase(-/-) and wild-type, but not gpx-1(-/-), mice. Hepcidin expression was inhibited in alcohol-fed catalase(-/-) and wild-type mice. In contrast, alcohol elevated hepcidin expression in gpx-1(-/-) mice. Gpx-1(-/-) mice also displayed higher level of basal liver CHOP protein expression than catalase(-/-) mice. Alcohol induced CHOP and to a lesser extent GRP78/BiP expression, but not XBP1 splicing or binding of CREBH to hepcidin gene promoter, in gpx-1(-/-) mice. The up-regulation of hepatic ATF4 mRNA levels, which was observed in gpx-1(-/-) mice, was attenuated by alcohol. In conclusion, our findings strongly suggest that H2O2 inhibits hepcidin expression in vivo. Synergistic induction of CHOP by alcohol and H2O2, in the absence of gpx-1, stimulates liver hepcidin gene expression by ER stress independent of CREBH.

  11. Male mice that lack the G-protein-coupled receptor GPR41 have low energy expenditure and increased body fat content.

    Science.gov (United States)

    Bellahcene, Mohamed; O'Dowd, Jacqueline F; Wargent, Ed T; Zaibi, Mohamed S; Hislop, David C; Ngala, Robert A; Smith, David M; Cawthorne, Michael A; Stocker, Claire J; Arch, Jonathan R S

    2013-05-28

    SCFA are produced in the gut by bacterial fermentation of undigested carbohydrates. Activation of the Gαi-protein-coupled receptor GPR41 by SCFA in β-cells and sympathetic ganglia inhibits insulin secretion and increases sympathetic outflow, respectively. A possible role in stimulating leptin secretion by adipocytes is disputed. In the present study, we investigated energy balance and glucose homoeostasis in GPR41 knockout mice fed on a standard low-fat or a high-fat diet. When fed on the low-fat diet, body fat mass was raised and glucose tolerance was impaired in male but not female knockout mice compared to wild-type mice. Soleus muscle and heart weights were reduced in the male mice, but total body lean mass was unchanged. When fed on the high-fat diet, body fat mass was raised in male but not female GPR41 knockout mice, but by no more in the males than when they were fed on the low-fat diet. Body lean mass and energy expenditure were reduced in male mice but not in female knockout mice. These results suggest that the absence of GPR41 increases body fat content in male mice. Gut-derived SCFA may raise energy expenditure and help to protect against obesity by activating GPR41.

  12. Deficient CD4+ T cell priming and regression of CD8+ T cell functionality in virus-infected mice lacking a normal B cell compartment

    DEFF Research Database (Denmark)

    Christensen, Jan Pravsgaard; Kauffmann, Susanne Ørding; Thomsen, Allan Randrup

    2003-01-01

    of virus-specific CD4(+) T cells was markedly impaired in B(-/-) mice infected with either virus strain. Thus, our results indicate that B cells play an important role in antiviral immunity not only as Ab producers, but also in promoting an optimal and sustained T cell response. The T cell defects......In this study, we investigate the state of T cell-mediated immunity in B cell-deficient (B(-/-)) mice infected with two strains of lymphocytic choriomeningitis virus known to differ markedly in their capacity to persist. In B(-/-) C57BL mice infected with the more persisting virus, virus......-specific CD8(+) T cells are initially generated that are qualitatively similar to those in wild-type mice. However, although cell numbers are well sustained over time, the capacity to produce cytokines is rapidly impaired. In similarly infected B(-/-) BALB/c mice, virus-specific CD8(+) T cells are completely...

  13. Short-Term Effects of Nose-Only Cigarette Smoke Exposure on Glutathione Redox Homeostasis, Cytochrome P450 1A1/2 and Respiratory Enzyme Activities in Mice Tissues

    Directory of Open Access Journals (Sweden)

    Haider Raza

    2013-05-01

    Full Text Available Background/Aims: The components of cigarette smoke (CS have been implicated in the development of cancer as well as in cardiopulmonary diseases. We have previously reported increased oxidative stress in rat tissues induced by tobacco-specific toxins nicotine and 4-(N-methyl-N-nitrosamino-1-(3-pyridyl-1-butanone (NNK. Recently, we have also shown increased oxidative stress and associated inflammatory responses in various tissues after exposure to cigarette smoke. Methods: In this study, we have further investigated the effects of nose-only cigarette smoke exposure on mitochondrial functions and glutathione-dependent redox metabolism in tissues of BALB/C mice. Liver, kidney, heart and lung tissues were analyzed for oxidative stress, glutathione (GSH and cytochrome P450 dependent enzyme activities and mitochondrial functions after exposure to smoke generated by 9 cigarettes/day for 4 days. Control mice were exposed to air only. Results: An increase in oxidative stress as observed by increased production of reactive oxygen species (ROS and altered GSH metabolism was apparent in all the tissues, but lung and heart appeared to be the main targets. Increased expression and activity of CYP450 1A1 and 1A2 were also observed in the tissues after exposure to cigarette smoke. Mitochondrial respiratory dysfunction in the tissues, as observed by alterations in the activities of Complex I and IV enzymes, was also observed after exposure to cigarette smoke. SDS-PAGE and Western blot results also indicate that alterations in the expression of enzyme proteins were in accordance with the changes in their catalytic functions. Conclusion: These results suggest that even short term exposure of cigarette smoke have adverse effects on mitochondrial functions and redox homeostasis in tissues which may progress to further complications associated with chronic smoking.

  14. Effects of aqueous extract of Ruta graveolens and its ingredients on cytochrome P450, uridine diphosphate (UDP-glucuronosyltransferase, and reduced nicotinamide adenine dinucleotide (phosphate (NAD(PH-quinone oxidoreductase in mice

    Directory of Open Access Journals (Sweden)

    Yune-Fang Ueng

    2015-09-01

    Full Text Available Ruta graveolens (the common rue has been used for various therapeutic purposes, including relief of rheumatism and treatment of circulatory disorder. To elucidate the effects of rue on main drug-metabolizing enzymes, effects of an aqueous extract of the aerial part of rue and its ingredients on cytochrome P450 (P450/CYP, uridine diphosphate (UDP-glucuronosyltransferase, and reduced nicotinamide adenine dinucleotide (phosphate (NAD(PH:quinone oxidoreductase were studied in C57BL/6JNarl mice. Oral administration of rue extract to males increased hepatic Cyp1a and Cyp2b activities in a dose-dependent manner. Under a 7-day treatment regimen, rue extract (0.5 g/kg induced hepatic Cyp1a and Cyp2b activities and protein levels in males and females. This treatment increased hepatic UDP-glucuronosyltransferase activity only in males. However, NAD(PH:quinone oxidoreductase activity remained unchanged. Based on the contents of rutin and furanocoumarins of mouse dose of rue extract, rutin increased hepatic Cyp1a activity and the mixture of furanocoumarins (Fmix increased Cyp2b activities in males. The mixture of rutin and Fmix increased Cyp1a and Cyp2b activities. These results revealed that rutin and Fmix contributed at least in part to the P450 induction by rue.

  15. Deletion of the Thyroid Hormone-Activating Type 2 Deiodinase Rescues Cone Photoreceptor Degeneration but Not Deafness in Mice Lacking Type 3 Deiodinase.

    Science.gov (United States)

    Ng, Lily; Liu, Hong; St Germain, Donald L; Hernandez, Arturo; Forrest, Douglas

    2017-06-01

    Type 2 deiodinase amplifies and type 3 deiodinase depletes levels of the active form of thyroid hormone, triiodothyronine. Given the opposing activities of these enzymes, we tested the hypothesis that they counteract each other's developmental functions by investigating whether deletion of type 2 deiodinase (encoded by Dio2) modifies sensory phenotypes in type 3 deiodinase-deficient (Dio3-/-) mice. Dio3-/- mice display degeneration of retinal cones, the photoreceptors that mediate daylight and color vision. In Dio2-/- mice, cone function was largely normal but deletion of Dio2 in Dio3-/- mice markedly recovered cone numbers and electroretinogram responses, suggesting counterbalancing roles for both enzymes in cone survival. Both Dio3-/- and Dio2-/- strains exhibit deafness with cochlear abnormalities. In Dio3-/-;Dio2-/- mice, deafness was exacerbated rather than alleviated, suggesting unevenly balanced actions by these enzymes during auditory development. Dio3-/- mice also exhibit an atrophic thyroid gland, low thyroxine, and high triiodothyronine levels, but this phenotype was ameliorated in Dio3-/-;Dio2-/- mice, indicating counterbalancing roles for the enzymes in determining the thyroid hormone status. The results suggest that the composite action of these two enzymes is a critical determinant in visual and auditory development and in setting the systemic thyroid hormone status.

  16. Mice lacking NKT cells but with a complete complement of CD8+ T-cells are not protected against the metabolic abnormalities of diet-induced obesity.

    Directory of Open Access Journals (Sweden)

    Benjamin S Mantell

    Full Text Available The contribution of natural killer T (NKT cells to the pathogenesis of metabolic abnormalities of obesity is controversial. While the combined genetic deletion of NKT and CD8(+ T-cells improves glucose tolerance and reduces inflammation, interpretation of these data have been complicated by the recent observation that the deletion of CD8(+ T-cells alone reduces obesity-induced inflammation and metabolic dysregulation, leaving the issue of the metabolic effects of NKT cell depletion unresolved. To address this question, CD1d null mice (CD1d(-/-, which lack NKT cells but have a full complement of CD8(+ T-cells, and littermate wild type controls (WT on a pure C57BL/6J background were exposed to a high fat diet, and glucose intolerance, insulin resistance, dyslipidemia, inflammation, and obesity were assessed. Food intake (15.5±4.3 vs 15.3±1.8 kcal/mouse/day, weight gain (21.8±1.8 vs 22.8±1.4 g and fat mass (18.6±1.9 vs 19.5±2.1 g were similar in CD1d(-/- and WT, respectively. As would be expected from these data, metabolic rate (3.0±0.1 vs 2.9±0.2 ml O(2/g/h and activity (21.6±4.3 vs 18.5±2.6 beam breaks/min were unchanged by NKT cell depletion. Furthermore, the degree of insulin resistance, glucose intolerance, liver steatosis, and adipose and liver inflammatory marker expression (TNFα, IL-6, IL-10, IFN-γ, MCP-1, MIP1α induced by high fat feeding in CD1d(-/- were not different from WT. We conclude that deletion of NKT cells, in the absence of alterations in the CD8(+ T-cell population, is insufficient to protect against the development of the metabolic abnormalities of diet-induced obesity.

  17. Changes in the expression of Hepatic Cytochrome P450 Isoenzymes 2E1, 2B1/2, 4A, and 2C6 in mice infected with different levels of Schistosoma Mansoni Cercariae

    International Nuclear Information System (INIS)

    Sheweita, Salah A.

    2005-01-01

    Most xenobiotic agents are metabolized by cytochrome P450 system. In the present study, Western blotting was used to investigate the effect of different levels of Schistosoma Mansoni infection on the expression of somr cytochrome P450 isozymes (CYP 2E1, 2B1/2, 2C6, 4A) and to enzyme assay their related metabolic functions in mouse liver microsomes. Male mice were infected with 60, 120, 180, 300 and 600 Schistosoma Mansoni cercariae per mouse for 33 days and 60, 120, 180 and 300 cercariae/mouse with no change at the last level of Schistosoma Mansoni infection. Also the expression of CYP 4A was potentially induced at all levels of Schistosoma Mansoni infection. A significant induction of CYP 2B1/2 expression was observed at all levels of Schistosoma Mansoni infection with loss of signal at 180 cercariaea/mouse. In contrast, CYP 2C6 expression was induced at the first two levels and such expression was decreased at the last three levels. In addition, the infection of the mouse with 60, 120 and 180 cercariae/mouse decreased; [1] 7-methoxycoumarin O-demethylase activity by 36, 54 and 58% respectively; [2] 7-ethoxycoumarin O-deethylase activity by 33, 40 and 57% respectively; [3] coumarin hydroxlase activity by 33, 45 and 55% respectively. However, 300 and 600 cercariae/mouse induced: [1] 7-methoxycoumarin O-demethylase activity by 45 and 97% respectively: [2] 7-ethoxycoumarin O-deethylase activity by 26 and 90% respectively; [3] coumarin hydroxylase activity by 100 and 200% respectively. In addition, all levels of Schistosoma Mansoni infection decreased the sleeping time caused by hexobarital. It is concluded that different levels of Schistosoma Mansoni infection change the expression of different CYPisozymes and that these alterations could enhance the carcinogenicity of N-nitrosamines which is mainly dependent on CYP 2E1. The alterations in the expression of CYP 2E1, 4A and 2B1/2 isozymes as a result of Schistosoma Mansoni infection may change the therapeutic actions

  18. An Examination of the Role of L-Glutamate and Inosine 5'-Monophosphate in Hedonic Taste-Guided Behavior by Mice Lacking the T1R1 + T1R3 Receptor.

    Science.gov (United States)

    Blonde, Ginger D; Spector, Alan C

    2017-06-01

    The heterodimeric T1R1 + T1R3 receptor is considered critical for normal signaling of L-glutamate and 5'-ribonucleotides in the oral cavity. However, some taste-guided responsiveness remains in mice lacking one subunit of the receptor, suggesting that other receptors are sufficient to support some behaviors. Here, mice lacking both receptor subunits (KO) and wild-type (WT, both n = 13) mice were tested in a battery of behavioral tests. Mice were trained and tested in gustometers with a concentration series of Maltrin-580, a maltodextrin, in a brief-access test (10-s trials) as a positive control. Similar tests followed with monosodium glutamate (MSG) with and without the ribonucleotide inosine 5'-monophosphate (IMP), but always in the presence of the epithelial sodium channel blocker amiloride (A). Brief-access tests were repeated following short-term (30-min) and long-term (48-h) exposures to MSG + A + IMP and were also conducted with sodium gluconate replacing MSG. Finally, progressive ratio tests were conducted with Maltrin-580 or MSG + A + IMP, to assess appetitive behavior while minimizing satiation. Overall, MSG generated little concentration-dependent responding in either food-restricted WT or KO mice, even in combination with IMP. However, KO mice licked less to the amino acid stimuli, a measure of consummatory behavior in the brief-access tests. In contrast, both groups initiated a similar number of trials and had a similar breakpoint in the progressive ratio task, both measures of appetitive (approach) behavior. Collectively, these results suggest that while the T1R1 + T1R3 receptor is necessary for consummatory responding to MSG (+IMP), other receptors are sufficient to maintain appetitive responding to this "umami" stimulus complex in food-restricted mice. © The Author 2017. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  19. Selegiline Ameliorates Depression-Like Behavior in Mice Lacking the CD157/BST1 Gene, a Risk Factor for Parkinson’s Disease

    Directory of Open Access Journals (Sweden)

    Satoka Kasai

    2017-05-01

    Full Text Available Parkinson’s disease (PD, a neurodegenerative disorder, is accompanied by various non-motor symptoms including depression and anxiety, which may precede the onset of motor symptoms. Selegiline is an irreversible monoamine oxidase-B (MAO-B inhibitor, and is widely used in the treatment of PD and major depression. However, there are few reports about the effects of selegiline on non-motor symptoms in PD. The aim of this study was to explore the antidepressant and anxiolytic effects of selegiline, using CD157/BST1 knockout (CD157 KO mouse, a PD-related genetic model displaying depression and anxiety, compared with other antiparkinsonian drugs and an antidepressant, and was to investigate the effects of selegiline on biochemical parameters in emotion-related brain regions. A single administration of selegiline (1–10 mg/kg dose-dependently reduced immobility time in the forced swimming test (FST in CD157 KO mice, but not C57BL/6N wild-type (WT mice. At 10 mg/kg, but not 3 mg/kg, selegiline significantly increased climbing time in CD157 KO mice. A single administration of the antiparkinsonian drugs pramipexole (a dopamine (DA D2/D3 receptor agonist or rasagiline (another MAO-B inhibitor, and repeated injections of a noradrenergic and specific serotonergic antidepressant (NaSSA, mirtazapine, also decreased immobility time, but did not increase climbing time, in CD157 KO mice. The antidepressant-like effects of 10 mg/kg selegiline were comparable to those of 10 mg/kg rasagiline, and tended to be stronger than those of 1 mg/kg rasagiline. After the FST, CD157 KO mice showed decreases in striatal and hippocampal serotonin (5-HT content, cortical norepinephrine (NE content, and plasma corticosterone concentration. A single administration of selegiline at 10 mg/kg returned striatal 5-HT, cortical NE, and plasma corticosterone levels to those observed in WT mice. In the open field test (OFT, repeated administration of mirtazapine had anxiolytic effects

  20. Facilitated stimulus-response associative learning and long-term memory in mice lacking the NTAN1 amidase of the N-end rule pathway.

    Science.gov (United States)

    Balogh, S A; McDowell, C S; Tae Kwon, Y; Denenberg, V H

    2001-02-23

    The N-end rule relates the in vivo half-life of a protein to the identity of its N-terminal residue. Inactivation of the NTAN1 gene encoding the asparagine-specific N-terminal amidase in mice results in impaired spatial memory [26]. The studies described here were designed to further characterize the effects upon learning and memory of inactivating the NTAN1 gene. NTAN1-deficient mice were found to be better than wild-type mice on black-white and horizontal-vertical discrimination learning. They were also better at 8-week Morris maze retention testing when a reversal trial was not included in the testing procedures. In all three tasks NTAN1-deficient mice appeared to use a strong win-stay strategy. It is concluded that inactivating the asparagine-specific branch of the N-end rule pathway in mice results in impaired spatial learning with concomitant compensatory restructuring of the nervous system in favor of non-spatial (stimulus-response) learning.

  1. Anxiety- and depression-like behavior in mice lacking the CD157/BST1 gene, a risk factor for Parkinson’s disease

    Directory of Open Access Journals (Sweden)

    Olga eLopatina

    2014-04-01

    Full Text Available CD157, known as bone marrow stromal cell antigen-1, is a glycosylphosphatidylinositol-anchored ADP-ribosyl cyclase that supports the survival and function of B-lymphocytes and hematopoietic or intestinal stem cells. Although CD157/Bst1 is a risk locus in Parkinson’s disease (PD, little is known about the function of CD157 in the nervous system and contribution to PD progression. Here, we show that no apparent motor dysfunction was observed in young knockout (CD157-/- male mice under less aging-related effects on behaviors. CD157-/- mice exhibited anxiety-related and depression-like behaviors compared with wild-type mice. These behaviors were rescued through treatment with anti-psychiatric drugs and oxytocin. CD157 was weakly expressed in the amygdala and c-Fos immunoreactivity was less evident in CD157-/- mice than in wild-type mice. These results demonstrate for the first time that CD157 plays a role as a neuro-regulator and suggest a potential role in pre-motor symptoms in PD.

  2. Lack of immunoglobulin M suppression by immunoglobulin G antibody in thymectomized, irradiated, and bone marrow-reconstituted mice infected with Toxoplasma gondii.

    Science.gov (United States)

    Aryanpour, J; Hafizi, A; Modabber, F

    1980-03-01

    Thymectomized, irradiated, bone marrow-reconstituted (T-deprived) mie infected with an avirulent strain of Toxoplasma gondii produced antibody titers comparable to those produced in intact syngeneic mice. Both immunoglobulin M (IgM) and IgG antibodies were produced in T-deprived animals; however, the IgM antibody remained constant in the presence of increasing amounts of IgG. In the intact animals, IgM became undetectable by day 50 postinfection as expected. Feedback inhibition of IgM by IgG seems to be dependent upon T-cells in Toxoplasma-infected mice.

  3. Upregulation of B7 molecules (CD80 and CD86) and exacerbated eosinophilic pulmonary inflammatory response in mice lacking the IFN-beta gene

    DEFF Research Database (Denmark)

    Matheu, Victor; Treschow, Alexandra; Navikas, Vaidrius

    2003-01-01

    . OBJECTIVE: We sought to define the differential role of endogenous IFN-beta in controlling the development of allergic inflammation. METHODS: We assessed whether deletion of the gene encoding IFN-beta (IFNB) with knockout mice participated in the development of allergic response in ovalbumin (OVA......BACKGROUND: IFN-beta has been shown to be effective as therapy for multiple sclerosis. Some reports attributed its beneficial effects to the capacity to induce a T(H)2 response. However, other studies have suggested that endogenous type I IFN might downregulate the allergic response in mice...

  4. Lack of genotoxic effect of food dyes amaranth, sunset yellow and tartrazine and their metabolites in the gut micronucleus assay in mice.

    Science.gov (United States)

    Poul, Martine; Jarry, Gérard; Elhkim, Mostafa Ould; Poul, Jean-Michel

    2009-02-01

    The food dyes amaranth, sunset yellow and tartrazine were administered twice, at 24h intervals, by oral gavage to mice and assessed in the in vivo gut micronucleus test for genotoxic effects (frequency of micronucleated cells) and toxicity (apoptotic and mitotic cells). The concentrations of each compound and their main metabolites (sulfanilic acid and naphthionic acid) were measured in faeces during a 24-h period after single oral administrations of the food dyes to mice. Parent dye compounds and their main aromatic amine metabolites were detected in significant amounts in the environment of colonic cells. Acute oral exposure to food dye additives amaranth, sunset yellow and tartrazine did not induce genotoxic effect in the micronucleus gut assay in mice at doses up to 2000 mg/kg b.w. Food dyes administration increased the mitotic cells at all dose levels when compared to controls. These results suggest that the transient DNA damages previously observed in the colon of mice treated by amaranth and tartrazine by the in vivo comet assay [Sasaki, Y.F., Kawaguchi, S., Kamaya, A., Ohshita, M., Kabasawa, K., Iwama, K., Taniguchi, K., Tsuda, S., 2002. The comet assay with 8 mouse organs: results with 39 currently used food additives. Mutat. Res. 519, 103-119] are unable to be fixed in stable genotoxic lesions and might be partly explained by local cytotoxicity of the dyes.

  5. The lack of therapeutic effects in mice of the combined gamma-irradiated Mycobacterium leprae and viable BCG against Mycobacterium leprae infection

    International Nuclear Information System (INIS)

    Saito, Hajime; Tomioka, Haruaki; Kitagawa, Toshiyuki

    1985-01-01

    Gamma-irradiated M. leprae in combination with BCG given once biweekly to mice from 2 weeks for up to 187 days after infection with M. leprae caused no significant growth inhibition of M. leprae, at the site of the infection. (author)

  6. Lack of parvalbumin in mice leads to behavioral deficits relevant to all human autism core symptoms and related neural morphofunctional abnormalities.

    Science.gov (United States)

    Wöhr, M; Orduz, D; Gregory, P; Moreno, H; Khan, U; Vörckel, K J; Wolfer, D P; Welzl, H; Gall, D; Schiffmann, S N; Schwaller, B

    2015-03-10

    Gene mutations and gene copy number variants are associated with autism spectrum disorders (ASDs). Affected gene products are often part of signaling networks implicated in synapse formation and/or function leading to alterations in the excitation/inhibition (E/I) balance. Although the network of parvalbumin (PV)-expressing interneurons has gained particular attention in ASD, little is known on PV's putative role with respect to ASD. Genetic mouse models represent powerful translational tools for studying the role of genetic and neurobiological factors underlying ASD. Here, we report that PV knockout mice (PV(-/-)) display behavioral phenotypes with relevance to all three core symptoms present in human ASD patients: abnormal reciprocal social interactions, impairments in communication and repetitive and stereotyped patterns of behavior. PV-depleted mice also showed several signs of ASD-associated comorbidities, such as reduced pain sensitivity and startle responses yet increased seizure susceptibility, whereas no evidence for behavioral phenotypes with relevance to anxiety, depression and schizophrenia was obtained. Reduced social interactions and communication were also observed in heterozygous (PV(+/-)) mice characterized by lower PV expression levels, indicating that merely a decrease in PV levels might be sufficient to elicit core ASD-like deficits. Structural magnetic resonance imaging measurements in PV(-/-) and PV(+/-) mice further revealed ASD-associated developmental neuroanatomical changes, including transient cortical hypertrophy and cerebellar hypoplasia. Electrophysiological experiments finally demonstrated that the E/I balance in these mice is altered by modification of both inhibitory and excitatory synaptic transmission. On the basis of the reported changes in PV expression patterns in several, mostly genetic rodent models of ASD, we propose that in these models downregulation of PV might represent one of the points of convergence, thus providing a

  7. Differing impact of the deletion of hemochromatosis-associated molecules HFE and transferrin receptor-2 on the iron phenotype of mice lacking bone morphogenetic protein 6 or hemojuvelin.

    Science.gov (United States)

    Latour, Chloé; Besson-Fournier, Céline; Meynard, Delphine; Silvestri, Laura; Gourbeyre, Ophélie; Aguilar-Martinez, Patricia; Schmidt, Paul J; Fleming, Mark D; Roth, Marie-Paule; Coppin, Hélène

    2016-01-01

    Hereditary hemochromatosis, which is characterized by inappropriately low levels of hepcidin, increased dietary iron uptake, and systemic iron accumulation, has been associated with mutations in the HFE, transferrin receptor-2 (TfR2), and hemojuvelin (HJV) genes. However, it is still not clear whether these molecules intersect in vivo with bone morphogenetic protein 6 (BMP6)/mothers against decapentaplegic (SMAD) homolog signaling, the main pathway up-regulating hepcidin expression in response to elevated hepatic iron. To answer this question, we produced double knockout mice for Bmp6 and β2-microglobulin (a surrogate for the loss of Hfe) and for Bmp6 and Tfr2, and we compared their phenotype (hepcidin expression, Bmp/Smad signaling, hepatic and extrahepatic tissue iron accumulation) with that of single Bmp6-deficient mice and that of mice deficient for Hjv, alone or in combination with Hfe or Tfr2. Whereas the phenotype of Hjv-deficient females was not affected by loss of Hfe or Tfr2, that of Bmp6-deficient females was considerably worsened, with decreased Smad5 phosphorylation, compared with single Bmp6-deficient mice, further repression of hepcidin gene expression, undetectable serum hepcidin, and massive iron accumulation not only in the liver but also in the pancreas, the heart, and the kidneys. These results show that (1) BMP6 does not require HJV to transduce signal to hepcidin in response to intracellular iron, even if the loss of HJV partly reduces this signal, (2) another BMP ligand can replace BMP6 and significantly induce hepcidin expression in response to extracellular iron, and (3) BMP6 alone is as efficient at inducing hepcidin as the other BMPs in association with the HJV/HFE/TfR2 complex; they provide an explanation for the compensatory effect of BMP6 treatment on the molecular defect underlying Hfe hemochromatosis in mice. © 2015 by the American Association for the Study of Liver Diseases.

  8. Forced expression of laminin β1 in podocytes prevents nephrotic syndrome in mice lacking laminin β2, a model for Pierson syndrome

    Science.gov (United States)

    Suh, Jung Hee; Jarad, George; VanDeVoorde, Rene G.; Miner, Jeffrey H.

    2011-01-01

    Pierson syndrome is a congenital nephrotic syndrome with ocular and neurological defects caused by mutations in LAMB2, the gene encoding the basement membrane protein laminin β2 (Lamβ2). It is the kidney glomerular basement membrane (GBM) that is defective in Pierson syndrome, as Lamβ2 is a component of laminin-521 (LM-521; α5β2γ1), the major laminin in the mature GBM. In both Pierson syndrome and the Lamb2−/− mouse model for this disease, laminin β1 (Lamβ1), a structurally similar homolog of Lamβ2, is marginally increased in the GBM, but it fails to fully compensate for the loss of Lamβ2, leading to the filtration barrier defects and nephrotic syndrome. Here we generated several lines of Lamβ1 transgenic mice and used them to show that podocyte-specific Lamβ1 expression in Lamb2−/− mice abrogates the development of nephrotic syndrome, correlating with a greatly extended lifespan. In addition, the more Lamβ1 was expressed, the less urinary albumin was excreted. Transgenic Lamβ1 expression increased the level of Lamα5 in the GBM of rescued mice, consistent with the desired increased deposition of laminin-511 (α5β1γ1) trimers. Ultrastructural analysis revealed occasional knob-like subepithelial GBM thickening but intact podocyte foot processes in aged rescued mice. These results suggest the possibility that up-regulation of LAMB1 in podocytes, should it become achievable, would likely lessen the severity of nephrotic syndrome in patients carrying LAMB2 mutations. PMID:21876163

  9. Forced expression of laminin beta1 in podocytes prevents nephrotic syndrome in mice lacking laminin beta2, a model for Pierson syndrome.

    Science.gov (United States)

    Suh, Jung Hee; Jarad, George; VanDeVoorde, Rene G; Miner, Jeffrey H

    2011-09-13

    Pierson syndrome is a congenital nephrotic syndrome with ocular and neurological defects caused by mutations in LAMB2, the gene encoding the basement membrane protein laminin β2 (Lamβ2). It is the kidney glomerular basement membrane (GBM) that is defective in Pierson syndrome, as Lamβ2 is a component of laminin-521 (LM-521; α5β2γ1), the major laminin in the mature GBM. In both Pierson syndrome and the Lamb2(-/-) mouse model for this disease, laminin β1 (Lamβ1), a structurally similar homolog of Lamβ2, is marginally increased in the GBM, but it fails to fully compensate for the loss of Lamβ2, leading to the filtration barrier defects and nephrotic syndrome. Here we generated several lines of Lamβ1 transgenic mice and used them to show that podocyte-specific Lamβ1 expression in Lamb2(-/-) mice abrogates the development of nephrotic syndrome, correlating with a greatly extended lifespan. In addition, the more Lamβ1 was expressed, the less urinary albumin was excreted. Transgenic Lamβ1 expression increased the level of Lamα5 in the GBM of rescued mice, consistent with the desired increased deposition of laminin-511 (α5β1γ1) trimers. Ultrastructural analysis revealed occasional knob-like subepithelial GBM thickening but intact podocyte foot processes in aged rescued mice. These results suggest the possibility that up-regulation of LAMB1 in podocytes, should it become achievable, would likely lessen the severity of nephrotic syndrome in patients carrying LAMB2 mutations.

  10. Proportionate Dwarfism in Mice Lacking Heterochromatin Protein 1 Binding Protein 3 (HP1BP3) Is Associated With Alterations in the Endocrine IGF-1 Pathway.

    Science.gov (United States)

    Garfinkel, Benjamin P; Arad, Shiri; Le, Phuong T; Bustin, Michael; Rosen, Clifford J; Gabet, Yankel; Orly, Joseph

    2015-12-01

    Heterochromatin protein 1 binding protein 3 (HP1BP3) is a recently described histone H1-related protein with roles in chromatin structure and transcriptional regulation. To explore the potential physiological role of HP1BP3, we have previously described an Hp1bp3(-/-) mouse model with reduced postnatal viability and growth. We now find that these mice are proportionate dwarfs, with reduction in body weight, body length, and organ weight. In addition to their small size, microcomputed tomography analysis showed that Hp1bp3(-/-) mice present a dramatic impairment of their bone development and structure. By 3 weeks of age, mice of both sexes have severely impaired cortical and trabecular bone, and these defects persist into adulthood and beyond. Primary cultures of both osteoblasts and osteoclasts from Hp1bp3(-/-) bone marrow and splenocytes, respectively, showed normal differentiation and function, strongly suggesting that the impaired bone accrual is due to noncell autonomous systemic cues in vivo. One major endocrine pathway regulating both body growth and bone acquisition is the IGF regulatory system, composed of IGF-1, the IGF receptors, and the IGF-binding proteins (IGFBPs). At 3 weeks of age, Hp1bp3(-/-) mice exhibited a 60% reduction in circulating IGF-1 and a 4-fold increase in the levels of IGFBP-1 and IGFBP-2. These alterations were reflected in similar changes in the hepatic transcripts of the Igf1, Igfbp1, and Igfbp2 genes. Collectively, these results suggest that HP1BP3 plays a key role in normal growth and bone development by regulating transcription of endocrine IGF-1 components.

  11. Proportionate Dwarfism in Mice Lacking Heterochromatin Protein 1 Binding Protein 3 (HP1BP3) Is Associated With Alterations in the Endocrine IGF-1 Pathway

    OpenAIRE

    Garfinkel, Benjamin P.; Arad, Shiri; Le, Phuong T.; Bustin, Michael; Rosen, Clifford J.; Gabet, Yankel; Orly, Joseph

    2015-01-01

    Heterochromatin protein 1 binding protein 3 (HP1BP3) is a recently described histone H1-related protein with roles in chromatin structure and transcriptional regulation. To explore the potential physiological role of HP1BP3, we have previously described an Hp1bp3?/? mouse model with reduced postnatal viability and growth. We now find that these mice are proportionate dwarfs, with reduction in body weight, body length, and organ weight. In addition to their small size, microcomputed tomography...

  12. Elevated sensitivity to diet-induced obesity and insulin resistance in mice lacking 4E-BP1 and 4E-BP2.

    Science.gov (United States)

    Le Bacquer, Olivier; Petroulakis, Emmanuel; Paglialunga, Sabina; Poulin, Francis; Richard, Denis; Cianflone, Katherine; Sonenberg, Nahum

    2007-02-01

    The most common pathology associated with obesity is insulin resistance, which results in the onset of type 2 diabetes mellitus. Several studies have implicated the mammalian target of rapamycin (mTOR) signaling pathway in obesity. Eukaryotic translation initiation factor 4E-binding (eIF4E-binding) proteins (4E-BPs), which repress translation by binding to eIF4E, are downstream effectors of mTOR. We report that the combined disruption of 4E-BP1 and 4E-BP2 in mice increased their sensitivity to diet-induced obesity. Increased adiposity was explained at least in part by accelerated adipogenesis driven by increased expression of CCAAT/enhancer-binding protein delta (C/EBPdelta), C/EBPalpha, and PPARgamma coupled with reduced energy expenditure, reduced lipolysis, and greater fatty acid reesterification in the adipose tissue of 4E-BP1 and 4E-BP2 double KO mice. Increased insulin resistance in 4E-BP1 and 4E-BP2 double KO mice was associated with increased ribosomal protein S6 kinase (S6K) activity and impairment of Akt signaling in muscle, liver, and adipose tissue. These data clearly demonstrate the role of 4E-BPs as a metabolic brake in the development of obesity and reinforce the idea that deregulated mTOR signaling is associated with the development of the metabolic syndrome.

  13. Low transformation growth factor-β1 production and collagen synthesis correlate with the lack of hepatic periportal fibrosis development in undernourished mice infected with Schistosoma mansoni

    Directory of Open Access Journals (Sweden)

    Andreia Ferreira Barros

    2014-04-01

    Full Text Available Undernourished mice infected (UI submitted to low and long-lasting infections by Schistosoma mansoni are unable to develop the hepatic periportal fibrosis that is equivalent to Symmers’ fibrosis in humans. In this report, the effects of the host’s nutritional status on parasite (worm load, egg viability and maturation and host (growth curves, biology, collagen synthesis and characteristics of the immunological response were studied and these are considered as interdependent factors influencing the amount and distribution of fibrous tissue in hepatic periovular granulomas and portal spaces. The nutritional status of the host influenced the low body weight and low parasite burden detected in UI mice as well as the number, viability and maturation of released eggs. The reduced oviposition and increased number of degenerated or dead eggs were associated with low protein synthesis detected in deficient hosts, which likely induced the observed decrease in transformation growth factor (TGF-β1 and liver collagen. Despite the reduced number of mature eggs in UI mice, the activation of TGF-β1 and hepatic stellate cells occurred regardless of the unviability of most miracidia, due to stimulation by fibrogenic proteins and eggshell glycoproteins. However, changes in the repair mechanisms influenced by the nutritional status in deficient animals may account for the decreased liver collagen detected in the present study.

  14. Cholesterol reduction and lack of genotoxic or toxic effects in mice after repeated 21-day oral intake of lemongrass (Cymbopogon citratus) essential oil.

    Science.gov (United States)

    Costa, Celso A R A; Bidinotto, Lucas T; Takahira, Regina K; Salvadori, Daisy M F; Barbisan, Luís F; Costa, Mirtes

    2011-09-01

    Cymbopogon citratus (lemongrass) is currently used in traditional folk medicine. Although this species presents widespread use, there are no scientific data on its efficacy or safety after repeated treatments. Therefore, this work investigated the toxicity and genotoxicity of this lemongrass's essential oil (EO) in male Swiss mice. The single LD(50) based on a 24h acute oral toxicity study was found to be around 3500 mg/kg. In a repeated-dose 21-day oral toxicity study, mice were randomly assigned to two control groups, saline- or Tween 80 0.01%-treated groups, or one of the three experimental groups receiving lemongrass EO (1, 10 or 100mg/kg). No significant changes in gross pathology, body weight, absolute or relative organ weights, histology (brain, heart, kidneys, liver, lungs, stomach, spleen and urinary bladder), urinalysis or clinical biochemistry were observed in EO-treated mice relative to the control groups. Additionally, blood cholesterol was reduced after EO-treatment at the highest dose tested. Similarly, data from the comet assay in peripheral blood cells showed no genotoxic effect from the EO. In conclusion, our findings verified the safety of lemongrass intake at the doses used in folk medicine and indicated the beneficial effect of reducing the blood cholesterol level. Copyright © 2011 Elsevier Ltd. All rights reserved.

  15. Lack of macrophage migration inhibitory factor in mice does not affect hallmarks of the inflammatory/immune response during the first week after stroke

    Directory of Open Access Journals (Sweden)

    Deierborg Tomas

    2011-06-01

    Full Text Available Abstract Background Macrophage migration inhibitory factor (MIF has been proposed to play a detrimental role in stroke. We recently showed that MIF promotes neuronal death and aggravates neurological deficits during the first week after experimental stroke, in mice. Since MIF regulates tissue inflammation, we studied the putative role of MIF in post-stroke inflammation. Methods We subjected C57BL/6 mice, Mif-/- (MIF-KO or Mif+/+ (WT, to a transient occlusion of the right middle cerebral artery (tMCAo or sham-surgery. We studied MIF expression, GFAP expression and the number of CD74-positive cells in the ischemic brain hemisphere 7 days after tMCAo using primarily immunohistochemistry. We determined IFN-γ, IL-2, IL-4, IL-5, IL-10, IL-12, KC/CXCL-1 and TNF-α protein levels in the brain (48 h after surgery and serum (48 h and 7 days after surgery by a multiplex immunoassay. Results We observed that MIF accumulates in neurons and astrocytes of the peri-infarct region, as well as in microglia/macrophages of the infarct core up to 7 days after stroke. Among the inflammatory mediators analyzed, we found a significant increase in cerebral IL-12 and KC levels after tMCAo, in comparison to sham-surgery. Importantly, the deletion of Mif did not significantly affect the levels of the cytokines evaluated, in the brain or serum. Moreover, the spleen weight 48 h and 7 days subsequent to tMCAo was similar in WT and MIF-KO mice. Finally, the extent of GFAP immunoreactivity and the number of MIF receptor (CD74-positive cells within the ischemic brain hemisphere did not differ significantly between WT and MIF-KO mice subjected to tMCAo. Conclusions We conclude that MIF does not affect major components of the inflammatory/immune response during the first week after experimental stroke. Based on present and previous evidence, we propose that the deleterious MIF-mediated effects in stroke depend primarily on an intraneuronal and/or interneuronal action.

  16. Lack of immunoglobulin M suppression by immunoglobulin G antibody in thymectomized, irradiated, and bone marrow-reconstituted mice infected with Toxoplasma gondii.

    OpenAIRE

    Aryanpour, J; Hafizi, A; Modabber, F

    1980-01-01

    Thymectomized, irradiated, bone marrow-reconstituted (T-deprived) mie infected with an avirulent strain of Toxoplasma gondii produced antibody titers comparable to those produced in intact syngeneic mice. Both immunoglobulin M (IgM) and IgG antibodies were produced in T-deprived animals; however, the IgM antibody remained constant in the presence of increasing amounts of IgG. In the intact animals, IgM became undetectable by day 50 postinfection as expected. Feedback inhibition of IgM by IgG ...

  17. Mice lacking the p75 receptor fail to acquire a normal complement of taste buds and geniculate ganglion neurons by adulthood

    OpenAIRE

    Krimm, Robin F.

    2006-01-01

    Brain derived neurotrophic factor and neurotrophin-4 are required for normal taste bud development. Although these neurotrophins normally function via the tyrosine kinase receptor, trkB, they also bind to the pan-neurotrophin receptor, p75. The goal of the present study was to determine whether the p75 receptor is required for the development or maintenance of a full complement of adult taste buds. Mice with p75 null mutations lose 34% of their circumvallate taste buds, 36% of their fungiform...

  18. Generation of Novel Traj18-Deficient Mice Lacking Vα14 Natural Killer T Cells with an Undisturbed T Cell Receptor α-Chain Repertoire.

    Directory of Open Access Journals (Sweden)

    Nyambayar Dashtsoodol

    Full Text Available Invariant Vα14 natural killer T (NKT cells, characterized by the expression of a single invariant T cell receptor (TCR α chain encoded by rearranged Trav11 (Vα14-Traj18 (Jα18 gene segments in mice, and TRAV10 (Vα24-TRAJ18 (Jα18 in humans, mediate adjuvant effects to activate various effector cell types in both innate and adaptive immune systems that facilitates the potent antitumor effects. It was recently reported that the Jα18-deficient mouse described by our group in 1997 harbors perturbed TCRα repertoire, which raised concerns regarding the validity of some of the experimental conclusions that have been made using this mouse line. To resolve this concern, we generated a novel Traj18-deficient mouse line by specifically targeting the Traj18 gene segment using Cre-Lox approach. Here we showed the newly generated Traj18-deficient mouse has, apart from the absence of Traj18, an undisturbed TCRα chain repertoire by using next generation sequencing and by detecting normal generation of Vα19Jα33 expressing mucosal associated invariant T cells, whose development was abrogated in the originally described Jα18-KO mice. We also demonstrated here the definitive requirement for NKT cells in the protection against tumors and their potent adjuvant effects on antigen-specific CD8 T cells.

  19. Increased Energy Expenditure, Ucp1 Expression, and Resistance to Diet-induced Obesity in Mice Lacking Nuclear Factor-Erythroid-2-related Transcription Factor-2 (Nrf2).

    Science.gov (United States)

    Schneider, Kevin; Valdez, Joshua; Nguyen, Janice; Vawter, Marquis; Galke, Brandi; Kurtz, Theodore W; Chan, Jefferson Y

    2016-04-01

    The NRF2 (also known as NFE2L2) transcription factor is a critical regulator of genes involved in defense against oxidative stress. Previous studies suggest thatNrf2plays a role in adipogenesisin vitro, and deletion of theNrf2gene protects against diet-induced obesity in mice. Here, we demonstrate that resistance to diet-induced obesity inNrf2(-/-)mice is associated with a 20-30% increase in energy expenditure. Analysis of bioenergetics revealed thatNrf2(-/-)white adipose tissues exhibit greater oxygen consumption. White adipose tissue showed a >2-fold increase inUcp1gene expression. Oxygen consumption is also increased nearly 2.5-fold inNrf2-deficient fibroblasts. Oxidative stress induced by glucose oxidase resulted in increasedUcp1expression. Conversely, antioxidant chemicals (such asN-acetylcysteine and Mn(III)tetrakis(4-benzoic acid)porphyrin chloride) and SB203580 (a known suppressor ofUcp1expression) decreasedUcp1and oxygen consumption inNrf2-deficient fibroblasts. These findings suggest that increasing oxidative stress by limitingNrf2function in white adipocytes may be a novel means to modulate energy balance as a treatment of obesity and related clinical disorders. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

  20. Androgen Receptor (AR) Physiological Roles in Male and Female Reproductive Systems: Lessons Learned from AR-Knockout Mice Lacking AR in Selective Cells1

    Science.gov (United States)

    Chang, Chawnshang; Lee, Soo Ok; Wang, Ruey-Sheng; Yeh, Shuyuan; Chang, Ta-Min

    2013-01-01

    ABSTRACT Androgens/androgen receptor (AR) signaling is involved primarily in the development of male-specific phenotypes during embryogenesis, spermatogenesis, sexual behavior, and fertility during adult life. However, this signaling has also been shown to play an important role in development of female reproductive organs and their functions, such as ovarian folliculogenesis, embryonic implantation, and uterine and breast development. The establishment of the testicular feminization (Tfm) mouse model exploiting the X-linked Tfm mutation in mice has been a good in vivo tool for studying the human complete androgen insensitivity syndrome, but this mouse may not be the perfect in vivo model. Mouse models with various cell-specific AR knockout (ARKO) might allow us to study AR roles in individual types of cells in these male and female reproductive systems, although discrepancies are found in results between labs, probably due to using various Cre mice and/or knocking out AR in different AR domains. Nevertheless, no doubt exists that the continuous development of these ARKO mouse models and careful studies will provide information useful for understanding AR roles in reproductive systems of humans and may help us to develop more effective and more specific therapeutic approaches for reproductive system-related diseases. PMID:23782840

  1. Increased oxidative metabolism and neurotransmitter cycling in the brain of mice lacking the thyroid hormone transporter SLC16A2 (MCT8).

    Science.gov (United States)

    Rodrigues, Tiago B; Ceballos, Ainhoa; Grijota-Martínez, Carmen; Nuñez, Barbara; Refetoff, Samuel; Cerdán, Sebastian; Morte, Beatriz; Bernal, Juan

    2013-01-01

    Mutations of the monocarboxylate transporter 8 (MCT8) cause a severe X-linked intellectual deficit and neurological impairment. MCT8 is a specific thyroid hormone (T4 and T3) transporter and the patients also present unusual abnormalities in the serum profile of thyroid hormone concentrations due to altered secretion and metabolism of T4 and T3. Given the role of thyroid hormones in brain development, it is thought that the neurological impairment is due to restricted transport of thyroid hormones to the target neurons. In this work we have investigated cerebral metabolism in mice with Mct8 deficiency. Adult male mice were infused for 30 minutes with (1-(13)C) glucose and brain extracts prepared and analyzed by (13)C nuclear magnetic resonance spectroscopy. Genetic inactivation of Mct8 resulted in increased oxidative metabolism as reflected by increased glutamate C4 enrichment, and of glutamatergic and GABAergic neurotransmissions as observed by the increases in glutamine C4 and GABA C2 enrichments, respectively. These changes were distinct to those produced by hypothyroidism or hyperthyroidism. Similar increments in glutamate C4 enrichment and GABAergic neurotransmission were observed in the combined inactivation of Mct8 and D2, indicating that the increased neurotransmission and metabolic activity were not due to increased production of cerebral T3 by the D2-encoded type 2 deiodinase. In conclusion, Mct8 deficiency has important metabolic consequences in the brain that could not be correlated with deficiency or excess of thyroid hormone supply to the brain during adulthood.

  2. A complex of cardiac cytochrome c1 and cytochrome c.

    Science.gov (United States)

    Chiang, Y L; Kaminsky, L S; King, T E

    1976-01-10

    The interactions of cytochrome c1 and cytochrome c from bovine cardiac mitochondria were investigated. Cytochrome c1 and cytochrome c formed a 1:1 molecular complex in aqueous solutions of low ionic strength. The complex was stable to Sephadex G-75 chromatography. The formation and stability of the complex were independent of the oxidation state of the cytochrome components as far as those reactions studied were concerned. The complex was dissociated in solutions of ionic strength higher than 0.07 or pH exceeding 10 and only partially dissociated in 8 M urea. No complexation occurred when cytochrome c was acetylated on 64% of its lysine residues or photooxidized on its 2 methionine residues. Complexes with molecular ratios of less than 1:1 (i.e. more cytochrome c) were obtained when polymerized cytochrome c, or cytochrome c with all lysine residues guanidinated, or a "1-65 heme peptide" from cyanogen bromide cleavage of cytochrome c was used. These results were interpreted to imply that the complex was predominantly maintained by ionic interactions probably involving some of the lysine residues of cytochrome c but with major stabilization dependent on the native conformations of both cytochromes. The reduced complex was autooxidizable with biphasic kinetics with first order rate constants of 6 X 10(-5) and 5 X U0(-5) s-1 but did not react with carbon monoxide. The complex reacted with cyanide and was reduced by ascorbate at about 32% and 40% respectively, of the rates of reaction with cytochrome c alone. The complex was less photoreducible than cytochrome c1 alone. The complex exhibited remarkably different circular dichroic behavior from that of the summation of cytochrome c1 plus cytochrome c. We concluded that when cytochromes c1 and c interacted they underwent dramatic conformational changes resulting in weakening of their heme crevices. All results available would indicate that in the complex cytochrome c1 was bound at the entrance to the heme crevice of

  3. Comparative Assessment of Induced Immune Responses Following Intramuscular Immunization with Fusion and Cocktail of LeIF, LACK and TSA Genes Against Cutaneous Leishmaniasis in BALB/c Mice.

    Science.gov (United States)

    Maspi, Nahid; Ghaffarifar, Fatemeh; Sharifi, Zohreh; Dalimi, Abdolhossein; Dayer, Mohammad Saaid

    2018-02-01

    In the present study, we evaluated induced immune responses following DNA vaccine containing cocktail or fusion of LeIF, LACK and TSA genes or each gene alone. Mice were injected with 100 µg of each plasmid containing the gene of insert, plasmid DNA alone as the first control group or phosphate buffer saline as the second control group. Then, cellular and humoral responses, lesion size were measured for all groups. All vaccinated mice induced Th1 immune responses against Leishmania characterized by higher IFN-γ and IgG2a levels compared with control groups (p < 0.05). In addition, IFN-γ levels increased in groups immunized with fusion and cocktail vaccines in comparison with LACK (p < 0.001) and LeIF (p < 0.01) groups after challenge. In addition, fusion and cocktail groups produced higher IgG2a values than groups vaccinated with a gene alone (p < 0.05). Lesion progression delayed for all immunized groups compared with control groups from 5th week post-infection (p < 0.05). Mean lesion size decreased in immunized mice with fusion DNA than three groups vaccinated with one gene alone (p < 0.05). While, lesion size decreased significantly in cocktail recipient group than LeIF recipient group (p < 0.05). There was no difference in lesion size between fusion and cocktail groups. Overall, immunized mice with cocktail and fusion vaccines showed stronger Th1 response by production of higher IFN-γ and IgG2a and showed smaller mean lesion size. Therefore, use of multiple antigens can improve induced immune responses by DNA vaccination.

  4. Data describing lack of effects of 17α-ethinyl estradiol on mammary gland morphology in female mice exposed during pregnancy and lactation.

    Science.gov (United States)

    LaPlante, Charlotte D; Vandenberg, Laura N

    2017-10-01

    Ethinyl estradiol (EE) is a synthetic estrogen used in pharmaceutical contraceptives. In many studies evaluating estrogenic endocrine disruptors, EE is used as a positive control for estrogenicity. However, the effects of EE often differ from the effects of other xenoestrogens, suggesting that these other compounds might act via distinct mechanisms. Reported here are data describing the effect of low doses of EE during pregnancy and lactation on the morphology of the lactating mammary gland in CD-1 mice. The data suggest that these low doses have few if any discernable effects on mammary gland morphology. Alterations to cell proliferation and the expression of estrogen receptor (ER)α were also not observed. These companion data were collected from the same females analyzed for effects of EE on maternal behavior and brain recently published in Reproductive Toxicology (Catanese & Vandenberg, 2017).

  5. Data describing lack of effects of 17α-ethinyl estradiol on mammary gland morphology in female mice exposed during pregnancy and lactation

    Directory of Open Access Journals (Sweden)

    Charlotte D. LaPlante

    2017-10-01

    Full Text Available Ethinyl estradiol (EE is a synthetic estrogen used in pharmaceutical contraceptives. In many studies evaluating estrogenic endocrine disruptors, EE is used as a positive control for estrogenicity. However, the effects of EE often differ from the effects of other xenoestrogens, suggesting that these other compounds might act via distinct mechanisms. Reported here are data describing the effect of low doses of EE during pregnancy and lactation on the morphology of the lactating mammary gland in CD-1 mice. The data suggest that these low doses have few if any discernable effects on mammary gland morphology. Alterations to cell proliferation and the expression of estrogen receptor (ERα were also not observed. These companion data were collected from the same females analyzed for effects of EE on maternal behavior and brain recently published in Reproductive Toxicology (Catanese & Vandenberg, 2017.

  6. Increased oxidative metabolism and neurotransmitter cycling in the brain of mice lacking the thyroid hormone transporter SLC16A2 (MCT8.

    Directory of Open Access Journals (Sweden)

    Tiago B Rodrigues

    Full Text Available Mutations of the monocarboxylate transporter 8 (MCT8 cause a severe X-linked intellectual deficit and neurological impairment. MCT8 is a specific thyroid hormone (T4 and T3 transporter and the patients also present unusual abnormalities in the serum profile of thyroid hormone concentrations due to altered secretion and metabolism of T4 and T3. Given the role of thyroid hormones in brain development, it is thought that the neurological impairment is due to restricted transport of thyroid hormones to the target neurons. In this work we have investigated cerebral metabolism in mice with Mct8 deficiency. Adult male mice were infused for 30 minutes with (1-(13C glucose and brain extracts prepared and analyzed by (13C nuclear magnetic resonance spectroscopy. Genetic inactivation of Mct8 resulted in increased oxidative metabolism as reflected by increased glutamate C4 enrichment, and of glutamatergic and GABAergic neurotransmissions as observed by the increases in glutamine C4 and GABA C2 enrichments, respectively. These changes were distinct to those produced by hypothyroidism or hyperthyroidism. Similar increments in glutamate C4 enrichment and GABAergic neurotransmission were observed in the combined inactivation of Mct8 and D2, indicating that the increased neurotransmission and metabolic activity were not due to increased production of cerebral T3 by the D2-encoded type 2 deiodinase. In conclusion, Mct8 deficiency has important metabolic consequences in the brain that could not be correlated with deficiency or excess of thyroid hormone supply to the brain during adulthood.

  7. Lack of TNF-alpha receptor type 2 protects motor neurons in a cellular model of amyotrophic lateral sclerosis and in mutant SOD1 mice but does not affect disease progression.

    Science.gov (United States)

    Tortarolo, Massimo; Vallarola, Antonio; Lidonnici, Dario; Battaglia, Elisa; Gensano, Francesco; Spaltro, Gabriella; Fiordaliso, Fabio; Corbelli, Alessandro; Garetto, Stefano; Martini, Elisa; Pasetto, Laura; Kallikourdis, Marinos; Bonetto, Valentina; Bendotti, Caterina

    2015-10-01

    Changes in the homeostasis of tumor necrosis factor α (TNFα) have been demonstrated in patients and experimental models of amyotrophic lateral sclerosis (ALS). However, the contribution of TNFα to the development of ALS is still debated. TNFα is expressed by glia and neurons and acts through the membrane receptors TNFR1 and TNFR2, which may have opposite effects in neurodegeneration. We investigated the role of TNFα and its receptors in the selective motor neuron death in ALS in vitro and in vivo. TNFR2 expressed by astrocytes and neurons, but not TNFR1, was implicated in motor neuron loss in primary SOD1-G93A co-cultures. Deleting TNFR2 from SOD1-G93A mice, there was partial but significant protection of spinal motor neurons, sciatic nerves, and tibialis muscles. However, no improvement of motor impairment or survival was observed. Since the sciatic nerves of SOD1-G93A/TNFR2-/- mice showed high phospho-TAR DNA-binding protein 43 (TDP-43) accumulation and low levels of acetyl-tubulin, two indices of axonal dysfunction, the lack of symptom improvement in these mice might be due to impaired function of rescued motor neurons. These results indicate the interaction between TNFR2 and membrane-bound TNFα as an innovative pathway involved in motor neuron death. Nevertheless, its inhibition is not sufficient to stop disease progression in ALS mice, underlining the complexity of this pathology. We show evidence of the involvement of neuronal and astroglial TNFR2 in the motor neuron degeneration in ALS. Both concur to cause motor neuron death in primary astrocyte/spinal neuron co-cultures. TNFR2 deletion partially protects motor neurons and sciatic nerves in SOD1-G93A mice but does not improve their symptoms and survival. However, TNFR2 could be a new target for multi-intervention therapies. © 2015 International Society for Neurochemistry.

  8. Influence of acute and chronic administration of methadone hydrochloride on NADPH-cytochrome c reductase and cytochrome P-450 of mouse liver microsomes.

    Science.gov (United States)

    Datta, R K; Johnson, E A; Bhattacharjee, G; Stenger, R J

    1976-03-01

    Administration of a single acute dose (20 mg/kg body weight) of methadone hydrochloride to both male and female mice increased the specific activity of NADPH-cytochrome c reductase and did not change much the content of cytochrome P-450 of their liver microsomes. Administration of multiple acute doses of methadone in male mice increased the specific activity of cytochrome c reductase and the content of cytochrome P-450 of their liver microsomes. Chronic administration of progressively increasing doses of methadone (up to 40 mg/kg body weight) to male mice increased the specific activity of c reductase. Similar chronic administration of methadone up to 28 mg/kg body weight also increased the microsomal content of P-450, but with higher doses of methadone, the content of P-450 declined and finally dropped slightly below control levels. The levels of c reductase activity and P-450 content returned to normal about two weeks after discontinuation of methadone administration.

  9. Mice lacking Ras-GRF1 show contextual fear conditioning but not spatial memory impairments: convergent evidence from two independently generated mouse mutant lines

    Directory of Open Access Journals (Sweden)

    Raffaele ed'Isa

    2011-12-01

    Full Text Available Ras-GRF1 is a neuronal specific guanine exchange factor that, once activated by both ionotropic and metabotropic neurotransmitter receptors, can stimulate Ras proteins, leading to long-term phosphorylation of downstream signaling. The two available reports on the behavior of two independently generated Ras-GRF1 deficient mouse lines provide contrasting evidence on the role of Ras-GRF1 in spatial memory and contextual fear conditioning. These discrepancies may be due to the distinct alterations introduced in the mouse genome by gene targeting in the two lines that could differentially affect expression of nearby genes located in the imprinted region containing the Ras-grf1 locus. In order to determine the real contribution of Ras-GRF1 to spatial memory we compared in Morris Water Maze learning the Brambilla’s mice with a third mouse line (GENA53 in which a nonsense mutation was introduced in the Ras-GRF1 coding region without additional changes in the genome and we found that memory in this task is normal. Also, we measured both contextual and cued fear conditioning, which were previously reported to be affected in the Brambilla’s mice, and we confirmed that contextual learning but not cued conditioning is impaired in both mouse lines. In addition, we also tested both lines for the first time in conditioned place aversion in the Intellicage, an ecological and remotely controlled behavioral test, and we observed normal learning. Finally, based on previous reports of other mutant lines suggesting that Ras-GRF1 may control body weight, we also measured this non-cognitive phenotype and we confirmed that both Ras-GRF1 deficient mutants are smaller than their control littermates. In conclusion, we demonstrate that Ras-GRF1 has no unique role in spatial memory while its function in contextual fear conditioning is likely to be due not only to its involvement in amygdalar functions but possibly to some distinct hippocampal connections specific to

  10. Progressive hearing loss and gradual deterioration of sensory hair bundles in the ears of mice lacking the actin-binding protein Eps8L2.

    Science.gov (United States)

    Furness, David N; Johnson, Stuart L; Manor, Uri; Rüttiger, Lukas; Tocchetti, Arianna; Offenhauser, Nina; Olt, Jennifer; Goodyear, Richard J; Vijayakumar, Sarath; Dai, Yuhai; Hackney, Carole M; Franz, Christoph; Di Fiore, Pier Paolo; Masetto, Sergio; Jones, Sherri M; Knipper, Marlies; Holley, Matthew C; Richardson, Guy P; Kachar, Bechara; Marcotti, Walter

    2013-08-20

    Mechanotransduction in the mammalian auditory system depends on mechanosensitive channels in the hair bundles that project from the apical surface of the sensory hair cells. Individual stereocilia within each bundle contain a core of tightly packed actin filaments, whose length is dynamically regulated during development and in the adult. We show that the actin-binding protein epidermal growth factor receptor pathway substrate 8 (Eps8)L2, a member of the Eps8-like protein family, is a newly identified hair bundle protein that is localized at the tips of stereocilia of both cochlear and vestibular hair cells. It has a spatiotemporal expression pattern that complements that of Eps8. In the cochlea, whereas Eps8 is essential for the initial elongation of stereocilia, Eps8L2 is required for their maintenance in adult hair cells. In the absence of both proteins, the ordered staircase structure of the hair bundle in the cochlea decays. In contrast to the early profound hearing loss associated with an absence of Eps8, Eps8L2 null-mutant mice exhibit a late-onset, progressive hearing loss that is directly linked to a gradual deterioration in hair bundle morphology. We conclude that Eps8L2 is required for the long-term maintenance of the staircase structure and mechanosensory function of auditory hair bundles. It complements the developmental role of Eps8 and is a candidate gene for progressive age-related hearing loss.

  11. Lack of WDR36 leads to preimplantation embryonic lethality in mice and delays the formation of small subunit ribosomal RNA in human cells in vitro.

    Science.gov (United States)

    Gallenberger, Martin; Meinel, Dominik M; Kroeber, Markus; Wegner, Michael; Milkereit, Philipp; Bösl, Michael R; Tamm, Ernst R

    2011-02-01

    Mutations in WD repeat domain 36 gene (WDR36) play a causative role in some forms of primary open-angle glaucoma, a leading cause of blindness worldwide. WDR36 is characterized by the presence of multiple WD40 repeats and shows homology to Utp21, an essential protein component of the yeast small subunit (SSU) processome required for maturation of 18S rRNA. To clarify the functional role of WDR36 in the mammalian organism, we generated and investigated mutant mice with a targeted deletion of Wdr36. In parallel experiments, we used RNA interference to deplete WDR36 mRNA in mouse embryos and cultured human trabecular meshwork (HTM-N) cells. Deletion of Wdr36 in the mouse caused preimplantation embryonic lethality, and essentially similar effects were observed when WDR36 mRNA was depleted in mouse embryos by RNA interference. Depletion of WDR36 mRNA in HTM-N cells caused apoptotic cell death and upregulation of mRNA for BAX, TP53 and CDKN1A. By immunocytochemistry, staining for WDR36 was observed in the nucleolus of cells, which co-localized with that of nucleolar proteins such as nucleophosmin and PWP2. In addition, recombinant and epitope-tagged WDR36 localized to the nucleolus of HTM-N cells. By northern blot analysis, a substantial decrease in 21S rRNA, the precursor of 18S rRNA, was observed following knockdown of WDR36. In addition, metabolic-labeling experiments consistently showed a delay of 18S rRNA maturation in WDR36-depleted cells. Our results provide evidence that WDR36 is an essential protein in mammalian cells which is involved in the nucleolar processing of SSU 18S rRNA.

  12. Dengue envelope-based 'four-in-one' virus-like particles produced using Pichia pastoris induce enhancement-lacking, domain III-directed tetravalent neutralising antibodies in mice.

    Science.gov (United States)

    Rajpoot, Ravi Kant; Shukla, Rahul; Arora, Upasana; Swaminathan, Sathyamangalam; Khanna, Navin

    2018-06-05

    Dengue is a significant public health problem worldwide, caused by four antigenically distinct mosquito-borne dengue virus (DENV) serotypes. Antibodies to any given DENV serotype which can afford protection against that serotype tend to enhance infection by other DENV serotypes, by a phenomenon termed antibody-dependent enhancement (ADE). Antibodies to the viral pre-membrane (prM) protein have been implicated in ADE. We show that co-expression of the envelope protein of all four DENV serotypes, in the yeast Pichia pastoris, leads to their co-assembly, in the absence of prM, into tetravalent mosaic VLPs (T-mVLPs), which retain the serotype-specific antigenic integrity and immunogenicity of all four types of their monomeric precursors. Following a three-dose immunisation schedule, the T-mVLPs elicited EDIII-directed antibodies in mice which could neutralise all four DENV serotypes. Importantly, anti-T-mVLP antibodies did not augment sub-lethal DENV-2 infection of dengue-sensitive AG129 mice, based on multiple parameters. The 'four-in-one' tetravalent T-mVLPs possess multiple desirable features which may potentially contribute to safety (non-viral, prM-lacking and ADE potential-lacking), immunogenicity (induction of virus-neutralising antibodies), and low cost (single tetravalent immunogen produced using P. pastoris, an expression system known for its high productivity using simple inexpensive media). These results strongly warrant further exploration of this vaccine candidate.

  13. Antibody response against Betaferon® in immune tolerant mice: involvement of marginal zone B-cells and CD4+ T-cells and apparent lack of immunological memory.

    Science.gov (United States)

    Sauerborn, Melody; van Beers, Miranda M C; Jiskoot, Wim; Kijanka, Grzegorz M; Boon, Louis; Schellekens, Huub; Brinks, Vera

    2013-01-01

    The immunological processes underlying immunogenicity of recombinant human therapeutics are poorly understood. Using an immune tolerant mouse model we previously demonstrated that aggregates are a major trigger of the antidrug antibody (ADA) response against recombinant human interferon beta (rhIFNβ) products including Betaferon®, and that immunological memory seems to be lacking after a rechallenge with non-aggregated rhIFNβ. The apparent absence of immunological memory indicates a CD4+ T-cell independent (Tind) immune response underlying ADA formation against Betaferon®. This hypothesis was tested. Using the immune tolerant mouse model we first validated that rechallenge with highly aggregated rhIFNβ (Betaferon®) does not lead to a subsequent fast increase in ADA titers, suggesting a lack of immunological memory. Next we assessed whether Betaferon® could act as Tind antigen by inactivation of marginal zone (MZ) B-cells during treatment. MZ B-cells are major effector cells involved in a Tind immune response. In a following experiment we depleted the mice from CD4+ T-cells to test their involvement in the ADA response against Betaferon®. Inactivation of MZ B-cells at the start of Betaferon® treatment drastically lowered ADA levels, suggesting a Tind immune response. However, persistent depletion of CD4+ T-cells before and during Betaferon® treatment abolished the ADA response in almost all mice. The immune response against rhIFNβ in immune tolerant mice is neither a T-cell independent nor a classical T-cell dependent immune response. Further studies are needed to confirm absence of immunological memory (cells).

  14. Aspirin Induces Apoptosis through Release of Cytochrome c from Mitochondria

    Directory of Open Access Journals (Sweden)

    Katja C. Zimmermann

    2000-01-01

    Full Text Available Nonsteroidal anti-inflammatory drugs (NSAID reduce the risk for cancer, due to their anti proliferative and apoptosis-inducing effects. A critical pathway for apoptosis involves the release of cytochrome c from mitochondria, which then interacts with Apaf-1 to activate caspase proteases that orchestrate cell death. In this study we found that treatment of a human cancer cell line with aspirin induced caspase activation and the apoptotic cell morphology, which was blocked by the caspase inhibitor zVAD-fmk. Further analysis of the mechanism underlying this apoptotic event showed that aspirin induces translocation of Bax to the mitochondria and triggers release of cytochrome c into the cytosol. The release of cytochrome c from mitochondria was inhibited by overexpression of the antiapoptotic protein Bcl-2 and cells that lack Apaf-1 were resistant to aspirin-induced apoptosis. These data provide evidence that the release of cytochrome c is an important part of the apoptotic mechanism of aspirin.

  15. Acute Systemic Infection with Dengue Virus Leads to Vascular Leakage and Death through Tumor Necrosis Factor-α and Tie2/Angiopoietin Signaling in Mice Lacking Type I and II Interferon Receptors.

    Science.gov (United States)

    Phanthanawiboon, Supranee; Limkittikul, Kriengsak; Sakai, Yusuke; Takakura, Nobuyuki; Saijo, Masayuki; Kurosu, Takeshi

    2016-01-01

    Severe dengue is caused by host responses to viral infection, but the pathogenesis remains unknown. This is, in part, due to the lack of suitable animal models. Here, we report a non-mouse-adapted low-passage DENV-3 clinical isolate, DV3P12/08, derived from recently infected patients. DV3P12/08 caused a lethal systemic infection in type I and II IFN receptor KO mice (IFN-α/β/γR KO mice), which have the C57/BL6 background. Infection with DV3P12/08 induced a cytokine storm, resulting in severe vascular leakage (mainly in the liver, kidney and intestine) and organ damage, leading to extensive hemorrhage and rapid death. DV3P12/08 infection triggered the release of large amounts of TNF-α, IL-6, and MCP-1. Treatment with a neutralizing anti-TNF-α antibody (Ab) extended survival and reduced liver damage without affecting virus production. Anti-IL-6 neutralizing Ab partly prolonged mouse survival. The anti-TNF-α Ab suppressed IL-6, MCP-1, and IFN-γ levels, suggesting that the severe response to infection was triggered by TNF-α. High levels of TNF-α mRNA were expressed in the liver and kidneys, but not in the small intestine, of infected mice. Conversely, high levels of IL-6 mRNA were expressed in the intestine. Importantly, treatment with Angiopoietin-1, which is known to stabilize blood vessels, prolonged the survival of DV3P12/08-infected mice. Taken together, the results suggest that an increased level of TNF-α together with concomitant upregulation of Tie2/Angiopoietin signaling have critical roles in severe dengue infection.

  16. The mechanism by which oxygen and cytochrome c increase the rate of electron transfer from cytochrome a to cytochrome a3 of cytochrome c oxidase.

    Science.gov (United States)

    Bickar, D; Turrens, J F; Lehninger, A L

    1986-11-05

    When cytochrome c oxidase is isolated from mitochondria, the purified enzyme requires both cytochrome c and O2 to achieve its maximum rate of internal electron transfer from cytochrome a to cytochrome a3. When reductants other than cytochrome c are used, the rate of internal electron transfer is very slow. In this paper we offer an explanation for the slow reduction of cytochrome a3 when reductants other than cytochrome c are used and for the apparent allosteric effects of cytochrome c and O2. Our model is based on the conventional understanding of cytochrome oxidase mechanism (i.e. electron transfer from cytochrome a/CuA to cytochrome a3/CuB), but assumes a relatively rapid two-electron transfer between cytochrome a/CuA and cytochrome a3/CuB and a thermodynamic equilibrium in the "resting" enzyme (the enzyme as isolated) which favors reduced cytochrome a and oxidized cytochrome a3. Using the kinetic constants that are known for this reaction, we find that the activating effects of O2 and cytochrome c on the rate of electron transfer from cytochrome a to cytochrome a3 conform to the predictions of the model and so provide no evidence of any allosteric effects or control of cytochrome c oxidase by O2 or cytochrome c.

  17. Structure of the Zymomonas mobilis respiratory chain: oxygen affinity of electron transport and the role of cytochrome c peroxidase.

    Science.gov (United States)

    Balodite, Elina; Strazdina, Inese; Galinina, Nina; McLean, Samantha; Rutkis, Reinis; Poole, Robert K; Kalnenieks, Uldis

    2014-09-01

    The genome of the ethanol-producing bacterium Zymomonas mobilis encodes a bd-type terminal oxidase, cytochrome bc1 complex and several c-type cytochromes, yet lacks sequences homologous to any of the known bacterial cytochrome c oxidase genes. Recently, it was suggested that a putative respiratory cytochrome c peroxidase, receiving electrons from the cytochrome bc1 complex via cytochrome c552, might function as a peroxidase and/or an alternative oxidase. The present study was designed to test this hypothesis, by construction of a cytochrome c peroxidase mutant (Zm6-perC), and comparison of its properties with those of a mutant defective in the cytochrome b subunit of the bc1 complex (Zm6-cytB). Disruption of the cytochrome c peroxidase gene (ZZ60192) caused a decrease of the membrane NADH peroxidase activity, impaired the resistance of growing culture to exogenous hydrogen peroxide and hampered aerobic growth. However, this mutation did not affect the activity or oxygen affinity of the respiratory chain, or the kinetics of cytochrome d reduction. Furthermore, the peroxide resistance and membrane NADH peroxidase activity of strain Zm6-cytB had not decreased, but both the oxygen affinity of electron transport and the kinetics of cytochrome d reduction were affected. It is therefore concluded that the cytochrome c peroxidase does not terminate the cytochrome bc1 branch of Z. mobilis, and that it is functioning as a quinol peroxidase. © 2014 The Authors.

  18. The cytochrome p450 homepage.

    Science.gov (United States)

    Nelson, David R

    2009-10-01

    The Cytochrome P450 Homepage is a universal resource for nomenclature and sequence information on cytochrome P450 ( CYP ) genes. The site has been in continuous operation since February 1995. Currently, naming information for 11,512 CYPs are available on the web pages. The P450 sequences are manually curated by David Nelson, and the nomenclature system conforms to an evolutionary scheme such that members of CYP families and subfamilies share common ancestors. The organisation and content of the Homepage are described.

  19. Flower colour and cytochromes P450.

    Science.gov (United States)

    Tanaka, Yoshikazu; Brugliera, Filippa

    2013-02-19

    Cytochromes P450 play important roles in biosynthesis of flavonoids and their coloured class of compounds, anthocyanins, both of which are major floral pigments. The number of hydroxyl groups on the B-ring of anthocyanidins (the chromophores and precursors of anthocyanins) impact the anthocyanin colour, the more the bluer. The hydroxylation pattern is determined by two cytochromes P450, flavonoid 3'-hydroxylase (F3'H) and flavonoid 3',5'-hydroxylase (F3'5'H) and thus they play a crucial role in the determination of flower colour. F3'H and F3'5'H mostly belong to CYP75B and CYP75A, respectively, except for the F3'5'Hs in Compositae that were derived from gene duplication of CYP75B and neofunctionalization. Roses and carnations lack blue/violet flower colours owing to the deficiency of F3'5'H and therefore lack the B-ring-trihydroxylated anthocyanins based upon delphinidin. Successful redirection of the anthocyanin biosynthesis pathway to delphinidin was achieved by expressing F3'5'H coding regions resulting in carnations and roses with novel blue hues that have been commercialized. Suppression of F3'5'H and F3'H in delphinidin-producing plants reduced the number of hydroxyl groups on the anthocyanidin B-ring resulting in the production of monohydroxylated anthocyanins based on pelargonidin with a shift in flower colour to orange/red. Pelargonidin biosynthesis is enhanced by additional expression of a dihydroflavonol 4-reductase that can use the monohydroxylated dihydrokaempferol (the pelargonidin precursor). Flavone synthase II (FNSII)-catalysing flavone biosynthesis from flavanones is also a P450 (CYP93B) and contributes to flower colour, because flavones act as co-pigments to anthocyanins and can cause blueing and darkening of colour. However, transgenic plants expression of a FNSII gene yielded paler flowers owing to a reduction of anthocyanins because flavanones are precursors of anthocyanins and flavones.

  20. Aggravated restenosis and atherogenesis in ApoCIII transgenic mice but lack of protection in ApoCIII knockouts: the effect of authentic triglyceride-rich lipoproteins with and without ApoCIII.

    Science.gov (United States)

    Li, Haibo; Han, Yingchun; Qi, Rong; Wang, Yuhui; Zhang, Xiaohong; Yu, Maomao; Tang, Yin; Wang, Mengyu; Shu, Ya-Nan; Huang, Wei; Liu, Xinfeng; Rodrigues, Brian; Han, Mei; Liu, George

    2015-09-01

    Previously, our group and others have demonstrated a causative relationship between severe hypertriglyceridaemia and atherogenesis in mice. Furthermore, clinical investigations have shown high levels of plasma Apolipoprotein C-III (ApoCIII) associated with hypertriglyceridaemia and even cardiovascular disease. However, it remains unclear whether ApoCIII affects restenosis in vivo, and whether such an effect is mediated by ApoCIII alone, or in combination with hypertriglyceridaemia. We sought to investigate ApoCIII in restenosis and clarify how smooth muscle cells (SMCs) respond to authentic triglyceride-rich lipoproteins (TRLs) with or without ApoCIII (TRLs ± ApoCIII). ApoCIII transgenic (ApoCIIItg) and knockout (ApoCIII-/-) mice underwent endothelial denudation to model restenosis. Here, ApoCIIItg mice displayed severe hypertriglyceridaemia and increased neointimal formation compared with wild-type (WT) or ApoCIII-/- mice. Furthermore, increased proliferating cell nuclear antigen (PCNA)-positive cells, Mac-3, and vascular cell adhesion protein-1 (VCAM-1) expression, and 4-hydroxynonenal (4HNE) production were found in lesion sites. ApoCIIItg and ApoCIII-/- mice were then crossed to low-density lipoprotein receptor-deficient (Ldlr-/-) mice and fed an atherogenic diet. ApoCIIItg/Ldlr-/- mice had significantly increased atherosclerotic lesions. However, there was no statistical difference in restenosis between ApoCIII-/- and WT mice, and in atherosclerosis between ApoCIII/Ldlr double knockout and Ldlr-/- mice. SMCs were then incubated in vitro with authentic TRLs ± ApoCIII isolated from extreme hypertriglyceridaemia glycosylphosphatidylinositol-anchored high-density lipoprotein-binding protein 1-deficient (GPIHBP1-/-) mice crossed with ApoCIIItg or ApoCIII-/- mice. It was shown that TRLs + ApoCIII promoted SMC proliferation, VCAM-1 expression, and reactive oxygen species (ROS) production, and activated the Akt pathway. Scavenging ROS significantly reduced SMC

  1. Mice Lacking Free Fatty Acid Receptor 1 (GPR40/FFAR1) are Protected Against Conjugated Linoleic Acid-Induced Fatty Liver but Develop Inflammation and Insulin Resistance in the Brain.

    Science.gov (United States)

    Sartorius, Tina; Drescher, Andrea; Panse, Madhura; Lastovicka, Petr; Peter, Andreas; Weigert, Cora; Kostenis, Evi; Ullrich, Susanne; Häring, Hans-Ulrich

    2015-01-01

    Conjugated linoleic acids (CLAs) affect body fat distribution, induce insulin resistance and stimulate insulin secretion. The latter effect is mediated through the free fatty acid receptor-1 (GPR40/FFAR1). This study examines whether GPR40/FFAR1 interacts with tissue specific metabolic changes induced by CLAs. After chronic application of CLAs C57BL/6J wild type (WT) and GPR40/FFAR1 (Ffar1(-/-)) knockout mice developed insulin resistance. Although CLAs accumulated in liver up to 46-fold genotype-independently, hepatic triglycerides augmented only in WT mice. This triglyceride deposition was not associated with increased inflammation. In contrast, in brain of CLA fed Ffar1(-/-) mice mRNA levels of TNF-α were 2-fold higher than in brain of WT mice although CLAs accumulated genotype-independently in brain up to 4-fold. Concomitantly, Ffar1(-/-) mice did not respond to intracerebroventricular (i.c.v.) insulin injection with an increase in cortical activity while WT mice reacted as assessed by radiotelemetric electrocorticography (ECoG) measurements. In vitro incubation of primary murine astrocytes confirmed that CLAs stimulate neuronal inflammation independent of GPR40/FFAR1. This study discloses that GPR40/FFAR1 indirectly modulates organ-specific effects of CLAs: the expression of functional GPR40/FFAR1 counteracts CLA-induced inflammation and insulin resistance in the brain, but favors the development of fatty liver. © 2015 S. Karger AG, Basel.

  2. Heme exporter FLVCR1a regulates heme synthesis and degradation and controls activity of cytochromes P450.

    Science.gov (United States)

    Vinchi, Francesca; Ingoglia, Giada; Chiabrando, Deborah; Mercurio, Sonia; Turco, Emilia; Silengo, Lorenzo; Altruda, Fiorella; Tolosano, Emanuela

    2014-05-01

    The liver has one of the highest rates of heme synthesis of any organ. More than 50% of the heme synthesized in the liver is used for synthesis of P450 enzymes, which metabolize exogenous and endogenous compounds that include natural products, hormones, drugs, and carcinogens. Feline leukemia virus subgroup C cellular receptor 1a (FLVCR1a) is plasma membrane heme exporter that is ubiquitously expressed and controls intracellular heme content in hematopoietic lineages. We investigated the role of Flvcr1a in liver function in mice. We created mice with conditional disruption of Mfsd7b, which encodes Flvcr1a, in hepatocytes (Flvcr1a(fl/fl);alb-cre mice). Mice were analyzed under basal conditions, after phenylhydrazine-induced hemolysis, and after induction of cytochromes P450 synthesis. Livers were collected and analyzed by histologic, quantitative real-time polymerase chain reaction, and immunoblot analyses. Hepatic P450 enzymatic activities were measured. Flvcr1a(fl/fl);alb-cre mice accumulated heme and iron in liver despite up-regulation of heme oxygenase 1, ferroportin, and ferritins. Hepatic heme export activity of Flvcr1a was closely associated with heme biosynthesis, which is required to sustain cytochrome induction. Upon cytochromes P450 stimulation, Flvcr1a(fl/fl);alb-cre mice had reduced cytochrome activity, associated with accumulation of heme in hepatocytes. The expansion of the cytosolic heme pool in these mice was likely responsible for the early inhibition of heme synthesis and increased degradation of heme, which reduced expression and activity of cytochromes P450. In livers of mice, Flvcr1a maintains a free heme pool that regulates heme synthesis and degradation as well as cytochromes P450 expression and activity. These findings have important implications for drug metabolism. Copyright © 2014 AGA Institute. Published by Elsevier Inc. All rights reserved.

  3. Heme Exporter FLVCR1a Regulates Heme Synthesis and Degradation and Controls Activity of Cytochromes P450

    Science.gov (United States)

    Vinchi, Francesca; Ingoglia, Giada; Chiabrando, Deborah; Mercurio, Sonia; Turco, Emilia; Silengo, Lorenzo; Altruda, Fiorella; Tolosano, Emanuela

    2014-01-01

    Background & Aims The liver has one of the highest rates of heme synthesis of any organ. More than 50% of the heme synthesized in the liver is used for synthesis of P450 enzymes, which metabolize exogenous and endogenous compounds that include natural products, hormones, drugs, and carcinogens. Feline leukemia virus subgroup C cellular receptor 1a (FLVCR1a) is plasma membrane heme exporter that is ubiquitously expressed and controls intracellular heme content in hematopoietic lineages. We investigated the role of Flvcr1a in liver function in mice. Methods We created mice with conditional disruption of Mfsd7b, which encodes Flvcr1a, in hepatocytes (Flvcr1afl/fl;alb-cre mice). Mice were analyzed under basal conditions, after phenylhydrazine-induced hemolysis, and after induction of cytochromes P450 synthesis. Livers were collected and analyzed by histologic, quantitative real-time polymerase chain reaction, and immunoblot analyses. Hepatic P450 enzymatic activities were measured. Results Flvcr1afl/fl;alb-cre mice accumulated heme and iron in liver despite up-regulation of heme oxygenase 1, ferroportin, and ferritins. Hepatic heme export activity of Flvcr1a was closely associated with heme biosynthesis, which is required to sustain cytochrome induction. Upon cytochromes P450 stimulation, Flvcr1afl/fl;alb-cre mice had reduced cytochrome activity, associated with accumulation of heme in hepatocytes. The expansion of the cytosolic heme pool in these mice was likely responsible for the early inhibition of heme synthesis and increased degradation of heme, which reduced expression and activity of cytochromes P450. Conclusions In livers of mice, Flvcr1a maintains a free heme pool that regulates heme synthesis and degradation as well as cytochromes P450 expression and activity. These findings have important implications for drug metabolism. PMID:24486949

  4. Mercury modulates the cytochrome P450 1a1, 1a2 and 1b1 in C57BL/6J mice: in vivo and in vitro studies

    International Nuclear Information System (INIS)

    Amara, Issa E.A.; Anwar-Mohamed, Anwar; Abdelhamid, Ghada; El-Kadi, Ayman O.S.

    2013-01-01

    In the current study C57BL/6J mice were injected intraperitoneally with Hg 2+ in the absence and presence of TCDD. After 6 and 24 h the liver was harvested and the expression of Cyps was determined. In vitro, isolated hepatocytes were incubated with TCDD in the presence and absence of Hg 2+ . At the in vivo level, Hg 2+ significantly decreased the TCDD-mediated induction of Cyps at 6 h while potentiating their levels at 24 h. In vitro, Hg 2+ significantly inhibited the TCDD-mediated induction of Cyp1a1 in a concentration- and time-dependent manner. Interestingly, Hg 2+ increased the serum hemoglobin (Hb) levels in mice treated for 24 h. Upon treatment of isolated hepatocytes with Hb alone, there was an increase in the AhR-dependent luciferase activity with a subsequent increase in Cyp1a1 protein and catalytic activity levels. Importantly, when hepatocytes were treated for 2 h with Hg 2+ in the presence of TCDD, then the medium was replaced with new medium containing Hb, there was potentiation of the TCDD-mediated effect. In addition, Hg 2+ increased heme oxygenase-1 (HO-1) mRNA, which coincided with a decrease in the Cyp1a1 activity level. When the competitive HO-1 inhibitor, tin mesoporphyrin was applied to the hepatocytes there was a partial restoration of Hg 2+ -mediated inhibition of Cyp1a1 activity. In conclusion, we demonstrate for the first time that there is a differential modulation of the TCDD-mediated induction of Cyp1a1 by Hg 2+ in C57BL/6J mice livers and isolated hepatocytes. Moreover, this study implicates Hb as an in vivo specific modulator of Cyp1 family. -- Highlights: ► In vivo, Hg 2+ decreased the Cyps at 6 h while potentiating their levels at 24 h. ► In vitro, Hg 2+ significantly inhibited the TCDD-mediated induction of Cyps. ► Hg 2+ increased the serum Hb levels in animals treated for 24 h. ► Hb potentiated the TCDD-mediated effect on Cyps. ► Tin mesoporphyrin partially restored Hg 2+ -mediated inhibition of Cyp1a1.

  5. Differentially regulated protein kinase A (PKA) activity in adipose tissue and liver is associated with resistance to diet-induced obesity and glucose intolerance in mice that lack PKA regulatory subunit type IIα.

    Science.gov (United States)

    London, Edra; Nesterova, Maria; Sinaii, Ninet; Szarek, Eva; Chanturiya, Tatyana; Mastroyannis, Spyridon A; Gavrilova, Oksana; Stratakis, Constantine A

    2014-09-01

    The cAMP-dependent protein kinase A (PKA) signaling system is widely expressed and has a central role in regulating cellular metabolism in all organ systems affected by obesity. PKA has four regulatory (RIα, RIIα, RIβ, RIIβ) and four catalytic (Cα, Cβ, Cγ, Prkx) subunit isoforms that have tissue-specific expression profiles. In mice, knockout (KO) of RIIβ, the primary PKA regulatory subunit in adipose tissue or knockout of the catalytic subunit Cβ resulted in a lean phenotype that resists diet-induced obesity and associated metabolic complications. Here we report that the disruption of the ubiquitously expressed PKA RIIα subunit in mice (RIIαKO) confers resistance to diet-induced obesity, glucose intolerance, and hepatic steatosis. After 2-week high-fat diet exposure, RIIαKO mice weighed less than wild-type littermates. Over time this effect was more pronounced in female mice that were also leaner than their wild-type counterparts, regardless of the diet. Decreased intake of a high-fat diet contributed to the attenuated weight gain in RIIαKO mice. Additionally, RIIα deficiency caused differential regulation of PKA in key metabolic organs: cAMP-stimulated PKA activity was decreased in liver and increased in gonadal adipose tissue. We conclude that RIIα represents a potential target for therapeutic interventions in obesity, glucose intolerance, and nonalcoholic fatty liver disease.

  6. The role of p38 in mitochondrial respiration in male and female mice.

    Science.gov (United States)

    Ju, Xiaohua; Wen, Yi; Metzger, Daniel; Jung, Marianna

    2013-06-07

    p38 is a mitogen-activated protein kinase and mediates cell growth, cell differentiation, and synaptic plasticity. The aim of this study is to determine the extent to which p38 plays a role in maintaining mitochondrial respiration in male and female mice under a normal condition. To achieve this aim, we have generated transgenic mice that lack p38 in cerebellar Purkinje neurons by crossing Pcp2 (Purkinje cell protein 2)-Cre mice with p38(loxP/loxP) mice. Mitochondria from cerebellum were then isolated from the transgenic and wild-type mice to measure mitochondrial respiration using XF24 respirometer. The mRNA and protein expression of cytochrome c oxidase (COX) in cerebellum were also measured using RT-PCR and immunoblot methods. Separately, HT22 cells were used to determine the involvement of 17β-estradiol (E2) and COX in mitochondrial respiration. The genetic knockout of p38 in Purkinje neurons suppressed the mitochondrial respiration only in male mice and increased COX expression only in female mice. The inhibition of COX by sodium azide (SA) sharply suppressed mitochondrial respiration of HT22 cells in a manner that was protected by E2. These data suggest that p38 is required for the mitochondrial respiration of male mice. When p38 is below a normal level, females may maintain mitochondrial respiration through COX up-regulation. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  7. The novel cytochrome c6 of chloroplasts: a case of evolutionary bricolage?

    Science.gov (United States)

    Howe, Christopher J; Schlarb-Ridley, Beatrix G; Wastl, Juergen; Purton, Saul; Bendall, Derek S

    2006-01-01

    Cytochrome c6 has long been known as a redox carrier of the thylakoid lumen of cyanobacteria and some eukaryotic algae that can substitute for plastocyanin in electron transfer. Until recently, it was widely accepted that land plants lack a cytochrome c6. However, a homologue of the protein has now been identified in several plant species together with an additional isoform in the green alga Chlamydomonas reinhardtii. This form of the protein, designated cytochrome c6A, differs from the 'conventional' cytochrome c6 in possessing a conserved insertion of 12 amino acids that includes two absolutely conserved cysteine residues. There are conflicting reports of whether cytochrome c6A can substitute for plastocyanin in photosynthetic electron transfer. The evidence for and against this is reviewed and the likely evolutionary history of cytochrome c6A is discussed. It is suggested that it has been converted from a primary role in electron transfer to one in regulation within the chloroplast, and is an example of evolutionary 'bricolage'.

  8. Energy brands lack vitality

    International Nuclear Information System (INIS)

    Godri, S.; Wilders, E.

    2004-01-01

    The three Dutch energy companies (Nuon, Essent and Eneco Energie) have relatively little brand strength. The brands are not perceived to be sufficiently different from one another and are not valued by consumers. With liberalisation imminent, this is hardly a strong starting point. How can you win over consumers if it is not clear what is on offer? In the business market, decision-makers are better placed to distinguish between brands. However, the brands lack vitality in this sector of the market too. The only consolation is that the situation is by no means exclusive to the Netherlands [nl

  9. Non-cytochrome mediated mitochondrial ATP production in bloodstream form Trypanosoma brucei brucei

    NARCIS (Netherlands)

    Bienen, E. J.; Maturi, R. K.; Pollakis, G.; Clarkson, A. B.

    1993-01-01

    The life cycle of Trypanosoma brucei brucei involves a series of differentiation steps characterized by marked changes in mitochondrial development and function. The bloodstream forms of this parasite completely lack cytochromes and have not been considered to have any Krebs cycle function. It has

  10. Importance of c-Type cytochromes for U(VI reduction by Geobacter sulfurreducens

    Directory of Open Access Journals (Sweden)

    Leang Ching

    2007-03-01

    Full Text Available Abstract Background In order to study the mechanism of U(VI reduction, the effect of deleting c-type cytochrome genes on the capacity of Geobacter sulfurreducens to reduce U(VI with acetate serving as the electron donor was investigated. Results The ability of several c-type cytochrome deficient mutants to reduce U(VI was lower than that of the wild type strain. Elimination of two confirmed outer membrane cytochromes and two putative outer membrane cytochromes significantly decreased (ca. 50–60% the ability of G. sulfurreducens to reduce U(VI. Involvement in U(VI reduction did not appear to be a general property of outer membrane cytochromes, as elimination of two other confirmed outer membrane cytochromes, OmcB and OmcC, had very little impact on U(VI reduction. Among the periplasmic cytochromes, only MacA, proposed to transfer electrons from the inner membrane to the periplasm, appeared to play a significant role in U(VI reduction. A subpopulation of both wild type and U(VI reduction-impaired cells, 24–30%, accumulated amorphous uranium in the periplasm. Comparison of uranium-accumulating cells demonstrated a similar amount of periplasmic uranium accumulation in U(VI reduction-impaired and wild type G. sulfurreducens. Assessment of the ability of the various suspensions to reduce Fe(III revealed no correlation between the impact of cytochrome deletion on U(VI reduction and reduction of Fe(III hydroxide and chelated Fe(III. Conclusion This study indicates that c-type cytochromes are involved in U(VI reduction by Geobacter sulfurreducens. The data provide new evidence for extracellular uranium reduction by G. sulfurreducens but do not rule out the possibility of periplasmic uranium reduction. Occurrence of U(VI reduction at the cell surface is supported by the significant impact of elimination of outer membrane cytochromes on U(VI reduction and the lack of correlation between periplasmic uranium accumulation and the capacity for uranium

  11. Brucella abortus mutants lacking ATP-binding cassette transporter proteins are highly attenuated in virulence and confer protective immunity against virulent B. abortus challenge in BALB/c mice.

    Science.gov (United States)

    Truong, Quang Lam; Cho, Youngjae; Park, Soyeon; Park, Bo-Kyoung; Hahn, Tae-Wook

    2016-06-01

    Brucella abortus RB51 is an attenuated vaccine strain that has been most frequently used for bovine brucellosis. Although it is known to provide good protection in cattle, it still has some drawbacks including resistance to rifampicin, residual virulence and pathogenicity in humans. Thus, there has been a continuous interest on new safe and effective bovine vaccine candidates. In the present study, we have constructed unmarked mutants by deleting singly cydD and cydC genes, which encode ATP-binding cassette transporter proteins, from the chromosome of the virulent Brucella abortus isolate from Korean cow (referred to as IVK15). Both IVK15ΔcydD and ΔcydC mutants showed increased sensitivity to metal ions, hydrogen peroxide and acidic pH, which are mimic to intracellular environment during host infection. Additionally, the mutants exhibited a significant growth defect in RAW264.7 cells and greatly attenuated in mice. Vaccination of mice with either IVK15ΔcydC or IVK15ΔcydD mutant could elicit an anti-Brucella specific immunoglobulin G (IgG) and IgG subclass responses as well as enhance the secretion of interferon-gamma, and provided better protection against challenge with B. abortus strain 2308 than with the commercial B. abortus strain RB51 vaccine. Collectively, these results suggest that both IVK15ΔcydC and IVK15ΔcydD mutants could be an attenuated vaccine candidate against B. abortus. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. NADPH–Cytochrome P450 Oxidoreductase: Roles in Physiology, Pharmacology, and Toxicology

    Science.gov (United States)

    Ding, Xinxin; Wolf, C. Roland; Porter, Todd D.; Pandey, Amit V.; Zhang, Qing-Yu; Gu, Jun; Finn, Robert D.; Ronseaux, Sebastien; McLaughlin, Lesley A.; Henderson, Colin J.; Zou, Ling; Flück, Christa E.

    2013-01-01

    This is a report on a symposium sponsored by the American Society for Pharmacology and Experimental Therapeutics and held at the Experimental Biology 2012 meeting in San Diego, California, on April 25, 2012. The symposium speakers summarized and critically evaluated our current understanding of the physiologic, pharmacological, and toxicological roles of NADPH–cytochrome P450 oxidoreductase (POR), a flavoprotein involved in electron transfer to microsomal cytochromes P450 (P450), cytochrome b5, squalene mono-oxygenase, and heme oxygenase. Considerable insight has been derived from the development and characterization of mouse models with conditional Por deletion in particular tissues or partial suppression of POR expression in all tissues. Additional mouse models with global or conditional hepatic deletion of cytochrome b5 are helping to clarify the P450 isoform- and substrate-specific influences of cytochrome b5 on P450 electron transfer and catalytic function. This symposium also considered studies using siRNA to suppress POR expression in a hepatoma cell–culture model to explore the basis of the hepatic lipidosis phenotype observed in mice with conditional deletion of Por in liver. The symposium concluded with a strong translational perspective, relating the basic science of human POR structure and function to the impacts of POR genetic variation on human drug and steroid metabolism. PMID:23086197

  13. Lack of Exposure in a First-in-Man Study Due to Aldehyde Oxidase Metabolism: Investigated by Use of 14C-microdose, Humanized Mice, Monkey Pharmacokinetics, and In Vitro Methods.

    Science.gov (United States)

    Jensen, Klaus Gjervig; Jacobsen, Anne-Marie; Bundgaard, Christoffer; Nilausen, Dorrit Østergaard; Thale, Zia; Chandrasena, Gamini; Jørgensen, Martin

    2017-01-01

    Inclusion of a microdose of 14 C-labeled drug in the first-in-man study of new investigational drugs and subsequent analysis by accelerator mass spectrometry has become an integrated part of drug development at Lundbeck. It has been found to be highly informative with regard to investigations of the routes and rates of excretion of the drug and the human metabolite profiles according to metabolites in safety testing guidance and also when additional metabolism-related issues needed to be addressed. In the first-in-man study with the NCE Lu AF09535, contrary to anticipated, surprisingly low exposure was observed when measuring the parent compound using conventional bioanalysis. Parallel accelerator mass spectrometry analysis revealed that the low exposure was almost exclusively attributable to extensive metabolism. The metabolism observed in humans was mediated via a human specific metabolic pathway, whereas an equivalent extent of metabolism was not observed in preclinical species. In vitro, incubation studies in human liver cytosol revealed involvement of aldehyde oxidase (AO) in the biotransformation of Lu AF09535. In vivo, substantially lower plasma exposure of Lu AF09535 was observed in chimeric mice with humanized livers compared with control animals. In addition, Lu AF09535 exhibited very low oral bioavailability in monkeys despite relatively low clearance after intravenous administration in contrast to the pharmacokinetics in rats and dogs, both showing low clearance and high bioavailability. The in vitro and in vivo methods applied were proved useful for identifying and evaluating AO-dependent metabolism. Different strategies to integrate these methods for prediction of in vivo human clearance of AO substrates were evaluated. Copyright © 2016 by The American Society for Pharmacology and Experimental Therapeutics.

  14. Role of Asp544 in subunit I for Na+ pumping by Vitreoscilla cytochrome bo

    International Nuclear Information System (INIS)

    Chung, Yeon T.; Stark, Benjamin C.; Webster, Dale A.

    2006-01-01

    The conserved Glu540 in subunit I of Escherichia coli cytochrome bo (a H + pump) is replaced by Asp544 in the Vitreoscilla enzyme (a Na + pump). Site-directed mutagenesis of the Vitreoscilla cytochrome bo operon changed this Asp to Glu, and both wild type and mutant cyo's were transformed into E. coli strain GV100, which lacks cytochrome bo. Compared to the wild type transformant the Asp544Glu transformant had decreased ability to pump Na + as well as decreased stimulation in respiratory activity in the presence of Na + . Preliminary experiments indicated that this mutant also had increased ability to pump protons, suggesting that this single change may provide cation pumping specificity in this group of enzymes

  15. Spaceflight Effects on Cytochrome P450 Content in Mouse Liver.

    Directory of Open Access Journals (Sweden)

    Natalia Moskaleva

    Full Text Available Hard conditions of long-term manned spaceflight can affect functions of many biological systems including a system of drug metabolism. The cytochrome P450 (CYP superfamily plays a key role in the drug metabolism. In this study we examined the hepatic content of some P450 isoforms in mice exposed to 30 days of space flight and microgravity. The CYP content was established by the mass-spectrometric method of selected reaction monitoring (SRM. Significant changes in the CYP2C29, CYP2E1 and CYP1A2 contents were detected in mice of the flight group compared to the ground control group. Within seven days after landing and corresponding recovery period changes in the content of CYP2C29 and CYP1A2 returned to the control level, while the CYP2E1 level remained elevated. The induction of enzyme observed in the mice in the conditions of the spaceflight could lead to an accelerated biotransformation and change in efficiency of pharmacological agents, metabolizing by corresponding CYP isoforms. Such possibility of an individual pharmacological response to medication during long-term spaceflights and early period of postflight adaptation should be taken into account in space medicine.

  16. Cytochrome c1 exhibits two binding sites for cytochrome c in plants.

    Science.gov (United States)

    Moreno-Beltrán, Blas; Díaz-Quintana, Antonio; González-Arzola, Katiuska; Velázquez-Campoy, Adrián; De la Rosa, Miguel A; Díaz-Moreno, Irene

    2014-10-01

    In plants, channeling of cytochrome c molecules between complexes III and IV has been purported to shuttle electrons within the supercomplexes instead of carrying electrons by random diffusion across the intermembrane bulk phase. However, the mode plant cytochrome c behaves inside a supercomplex such as the respirasome, formed by complexes I, III and IV, remains obscure from a structural point of view. Here, we report ab-initio Brownian dynamics calculations and nuclear magnetic resonance-driven docking computations showing two binding sites for plant cytochrome c at the head soluble domain of plant cytochrome c1, namely a non-productive (or distal) site with a long heme-to-heme distance and a functional (or proximal) site with the two heme groups close enough as to allow electron transfer. As inferred from isothermal titration calorimetry experiments, the two binding sites exhibit different equilibrium dissociation constants, for both reduced and oxidized species, that are all within the micromolar range, thus revealing the transient nature of such a respiratory complex. Although the docking of cytochrome c at the distal site occurs at the interface between cytochrome c1 and the Rieske subunit, it is fully compatible with the complex III structure. In our model, the extra distal site in complex III could indeed facilitate the functional cytochrome c channeling towards complex IV by building a "floating boat bridge" of cytochrome c molecules (between complexes III and IV) in plant respirasome. Copyright © 2014 Elsevier B.V. All rights reserved.

  17. Cytochrome cbb3 of Thioalkalivibrio is a Na+-pumping cytochrome oxidase

    NARCIS (Netherlands)

    Muntyan, M.S.; Cherepanov, D.A.; Malinen, A.M.; Bloch, D.A.; Sorokin, D.Y.; Severina, I.I.; Ivashina, T.V.; Lahti, R.; Muyzer, G.; Skulachev, V.P.

    2015-01-01

    Cytochrome c oxidases (Coxs) are the basic energy transducers in the respiratory chain of the majority of aerobic organisms. Coxs studied to date are redox-driven proton-pumping enzymes belonging to one of three subfamilies: A-, B-, and C-type oxidases. The C-type oxidases (cbb3 cytochromes), which

  18. Comparison of brain mitochondrial cytochrome c oxidase activity with cyanide LD(50) yields insight into the efficacy of prophylactics.

    Science.gov (United States)

    Marziaz, Mandy L; Frazier, Kathryn; Guidry, Paul B; Ruiz, Robyn A; Petrikovics, Ilona; Haines, Donovan C

    2013-01-01

    Cyanide inhibits cytochrome c oxidase, the terminal oxidase of the mitochondrial respiratory pathway, therefore inhibiting the cell oxygen utilization and resulting in the condition of histotoxic anoxia. The enzyme rhodanese detoxifies cyanide by utilizing sulfur donors to convert cyanide to thiocyanate, and new and improved sulfur donors are actively sought as researchers seek to improve cyanide prophylactics. We have determined brain cytochrome c oxidase activity as a marker for cyanide exposure for mice pre-treated with various cyanide poisoning prophylactics, including sulfur donors thiosulfate (TS) and thiotaurine (TT3). Brain mitochondria were isolated by differential centrifugation, the outer mitochondrial membrane was disrupted by a maltoside detergent, and the decrease in absorbance at 550 nm as horse heart ferrocytochrome c (generated by the dithiothreitol reduction of ferricytochrome c) was oxidized was monitored. Overall, the TS control prophylactic treatment provided significant protection of the cytochrome c oxidase activity. The TT3-treated mice showed reduced cytochrome c oxidase activity even in the absence of cyanide. In both treatment series, addition of exogenous Rh did not significantly enhance the prevention of cytochrome c oxidase inhibition, but the addition of sodium nitrite did. These findings can lead to a better understanding of the protection mechanism by various cyanide antidotal systems. Copyright © 2011 John Wiley & Sons, Ltd.

  19. Cytochrome b5 and epoxide hydrolase contribute to benzo[a]pyrene-DNA adduct formation catalyzed by cytochrome P450 1A1 under low NADPH:P450 oxidoreductase conditions

    International Nuclear Information System (INIS)

    Stiborová, Marie; Moserová, Michaela; Černá, Věra; Indra, Radek; Dračínský, Martin; Šulc, Miroslav; Henderson, Colin J.; Wolf, C. Roland; Schmeiser, Heinz H.; Phillips, David H.; Frei, Eva; Arlt, Volker M.

    2014-01-01

    In previous studies we had administered benzo[a]pyrene (BaP) to genetically engineered mice (HRN) which do not express NADPH:cytochrome P450 oxidoreductase (POR) in hepatocytes and observed higher DNA adduct levels in livers of these mice than in wild-type mice. To elucidate the reason for this unexpected finding we have used two different settings for in vitro incubations; hepatic microsomes from control and BaP-pretreated HRN mice and reconstituted systems with cytochrome P450 1A1 (CYP1A1), POR, cytochrome b 5 , and epoxide hydrolase (mEH) in different ratios. In microsomes from BaP-pretreated mice, in which Cyp1a1 was induced, higher levels of BaP metabolites were formed, mainly of BaP-7,8-dihydrodiol. At a low POR:CYP1A1 ratio of 0.05:1 in the reconstituted system, the amounts of BaP diones and BaP-9-ol formed were essentially the same as at an equimolar ratio, but formation of BaP-3-ol was ∼1.6-fold higher. Only after addition of mEH were BaP dihydrodiols found. Two BaP-DNA adducts were formed in the presence of mEH, but only one when CYP1A1 and POR were present alone. At a ratio of POR:CYP1A1 of 0.05:1, addition of cytochrome b 5 increased CYP1A1-mediated BaP oxidation to most of its metabolites indicating that cytochrome b 5 participates in the electron transfer from NADPH to CYP1A1 required for enzyme activity of this CYP. BaP-9-ol was formed even by CYP1A1 reconstituted with cytochrome b 5 without POR. Our results suggest that in livers of HRN mice Cyp1a1, cytochrome b 5 and mEH can effectively activate BaP to DNA binding species, even in the presence of very low amounts of POR

  20. Functional environmental proteomics: elucidating the role of a c-type cytochrome abundant during uranium bioremediation.

    Science.gov (United States)

    Yun, Jiae; Malvankar, Nikhil S; Ueki, Toshiyuki; Lovley, Derek R

    2016-02-01

    Studies with pure cultures of dissimilatory metal-reducing microorganisms have demonstrated that outer-surface c-type cytochromes are important electron transfer agents for the reduction of metals, but previous environmental proteomic studies have typically not recovered cytochrome sequences from subsurface environments in which metal reduction is important. Gel-separation, heme-staining and mass spectrometry of proteins in groundwater from in situ uranium bioremediation experiments identified a putative c-type cytochrome, designated Geobacter subsurface c-type cytochrome A (GscA), encoded within the genome of strain M18, a Geobacter isolate previously recovered from the site. Homologs of GscA were identified in the genomes of other Geobacter isolates in the phylogenetic cluster known as subsurface clade 1, which predominates in a diversity of Fe(III)-reducing subsurface environments. Most of the gscA sequences recovered from groundwater genomic DNA clustered in a tight phylogenetic group closely related to strain M18. GscA was most abundant in groundwater samples in which Geobacter sp. predominated. Expression of gscA in a strain of Geobacter sulfurreducens that lacked the gene for the c-type cytochrome OmcS, thought to facilitate electron transfer from conductive pili to Fe(III) oxide, restored the capacity for Fe(III) oxide reduction. Atomic force microscopy provided evidence that GscA was associated with the pili. These results demonstrate that a c-type cytochrome with an apparent function similar to that of OmcS is abundant when Geobacter sp. are abundant in the subsurface, providing insight into the mechanisms for the growth of subsurface Geobacter sp. on Fe(III) oxide and suggesting an approach for functional analysis of other Geobacter proteins found in the subsurface.

  1. Genetic defects of cytochrome c oxidase assembly

    Czech Academy of Sciences Publication Activity Database

    Pecina, Petr; Houšťková, H.; Hansíková, H.; Zeman, J.; Houštěk, Josef

    2004-01-01

    Roč. 53, Suppl. 1 (2004), s. S213-S223 ISSN 0862-8408 R&D Projects: GA ČR GA303/03/0749 Institutional research plan: CEZ:AV0Z5011922 Keywords : cytochrome c oxidase * mitochondrial disorders Subject RIV: FB - Endocrinology, Diabetology, Metabolism, Nutrition Impact factor: 1.140, year: 2004

  2. Differential action on cancer and normal tissue by adrenochrome monoaminoguanidine methanesulfonate and cytochrome C combined with radiotherapy

    International Nuclear Information System (INIS)

    Nakatsugawa, S.; Sugahara, T.

    1994-01-01

    The possibility that radioprotective effects on potent natural killer (NK) cells by adrenochrome monoaminoguanidine methanesulfonate (AMM) + cytochrome C during radiotherapy (RT) for lung cancer might result in the radiosensitization of human lung cancer cells in vivo is examined. Human lung cancer xenografts in the right hind legs of KSN mice (10 weeks old) were locally irradiated with 20 Gy of X ray. AMM (10 mg/kg/day) and/or cytochrome C (CCC) (5 mg/kg/day) were given intraperitoneally immediately before or after RT, followed by daily administration for 4 days. Natural killer activities of host splenocytes were also tested with the standard 51 Cr releasing assay with YAC-1 cells as target cells. In a clinical study, 65 patients with lung cancer were treated with more than 50 Gy of RT with or without combination with AMM + CCC, OK-432 or AMM + CCC + OK-432. Before and after RT, lymphocyte subsets in the peripheral blood were examined with dichromatic analysis using an Ortho Spectrum IIIFCM system and fluorescent MABs. In this study, the change in the absolute number of each subset was investigated. AMM + cytochrome C augumented NK activity in KSN nude mice, protected potent NK cells in patients with lung cancer against RT and sensitized the human lung cancer xenografts to RT. AMM + cytochrome C may have potential as a differential modulator of radiosensitivity of normal tissues and of tumors. 8 refs., 2 figs., 1 tab

  3. The reaction of neuroglobin with potential redox protein partners cytochrome b5  and cytochrome c

    DEFF Research Database (Denmark)

    Fago, Angela; Mathews, A.J.; Moens, L.

    2006-01-01

    Previously identified, potentially neuroprotective reactions of neuroglobin require the existence of yet unknown redox partners. We show here that the reduction of ferric neuroglobin by cytochrome b5 is relatively slow (k=6×102M-1s-1 at pH 7.0) and thus is unlikely to be of physiological...... significance. In contrast, the reaction between ferrous neuroglobin and ferric cytochrome c is very rapid (k=2×107M-1s-1) with an apparent overall equilibrium constant of 1μM. Based on this data we propose that ferrous neuroglobin may well play a role in preventing apoptosis...

  4. Regulation of cytochrome P-450 monooxygenases in the mouse

    International Nuclear Information System (INIS)

    Kelley, M.F.

    1986-01-01

    Recently, the compound 1,4-bis[2-(3,4-dichloropyridyloxy)] benzene (TCPOBOP) has been identified as a highly potent phenobabital-like agonist in mice. This finding has led to the suggestion that a receptor-mediated process may govern the induction of cytochrome P-450 monooxygenases by phenobarbital and phenobarbital-like agonists. This dissertation examines: (1) the effects of structural alterations of the TCPOBOP molecule on enzyme induction activity, (2) the induction response to phenobarbital and TCPOBOP among inbred mouse strains, (3) the spectrum of monooxygenase activities induced by phenobarbital and TCPOBOP compared to 3-methylcholanthrene, isosafrole and pregnenolone 16α-carbonitrile (PCN) and (4) the binding of [ 3 H] TCPOBOP in hepatic cytosol. Changes in the structure of the pyridyloxy or benzene rings markedly affect enzyme induction activity and provide additional indirect evidence for a receptor-mediated response. An evaluation of monooxygenase induction by TCPOBOP for 27 inbred mouse strains and by phenobarbital for 15 inbred mouse strains failed to identify a strain which was completely nonresponsive to these compounds, although several strains exhibited decreased responsiveness for select monooxygenase reactions. TCPOBOP, PCN and phenobarbital were all found to significantly increase the rate of hydroxylation of testosterone at the 2α-, 6β- and 15β- positions but only TCPOBOP and phenobarbital dramatically increased the rate of pentoxyresorufin O-dealkylation. The results demonstrates that TCPOBOP most closely resembles phenobarbital in its mode of monooxygenase induction in mice. Sucrose density gradient analysis of [ 3 H] TCPOBOP-hepatic cytosol incubations failed to identify specific, saturable binding of [ 3 H] TCPOBOP to cytosolic marcomolecular elements

  5. Probing cytochrome c in living mitochondria with surface-enhanced Raman spectroscopy

    DEFF Research Database (Denmark)

    Brazhe, Nadezda A.; Evlyukhin, Andrey B.; Goodilin, Eugene A.

    2015-01-01

    Selective study of the electron transport chain components in living mitochondria is essential for fundamental biophysical research and for the development of new medical diagnostic methods. However, many important details of inter- and intramembrane mitochondrial processes have remained in shadow...... due to the lack of non-invasive techniques. Here we suggest a novel label-free approach based on the surface-enhanced Raman spectroscopy (SERS) to monitor the redox state and conformation of cytochrome c in the electron transport chain in living mitochondria. We demonstrate that SERS spectra of living...... mitochondria placed on hierarchically structured silver-ring substrates provide exclusive information about cytochrome c behavior under modulation of inner mitochondrial membrane potential, proton gradient and the activity of ATP-synthetase. Mathematical simulation explains the observed enhancement of Raman...

  6. New insight into the mechanism of mitochondrial cytochrome c function

    DEFF Research Database (Denmark)

    Chertkova, Rita V; Brazhe, Nadezda A; Bryantseva, Tatiana V

    2017-01-01

    We investigate functional role of the P76GTKMIFA83 fragment of the primary structure of cytochrome c. Based on the data obtained by the analysis of informational structure (ANIS), we propose a model of functioning of cytochrome c. According to this model, conformational rearrangements of the P76...... with conformational changes and reduced mobility of heme porphyrin. This points to a significant role of the P76GTKMIFA83 fragment in the electron transport function of cytochrome c....

  7. Cytochrome P450 monooxygenases and insecticide resistance in insects.

    OpenAIRE

    Bergé, J B; Feyereisen, R; Amichot, M

    1998-01-01

    Cytochrome P450 monooxygenases are involved in many cases of resistance of insects to insecticides. Resistance has long been associated with an increase in monooxygenase activities and with an increase in cytochrome P450 content. However, this increase does not always account for all of the resistance. In Drosophila melanogaster, we have shown that the overproduction of cytochrome P450 can be lost by the fly without a corresponding complete loss of resistance. These results prompted the seque...

  8. Prediction of cytochrome P450 mediated metabolism

    DEFF Research Database (Denmark)

    Olsen, Lars; Oostenbrink, Chris; Jørgensen, Flemming Steen

    2015-01-01

    Cytochrome P450 enzymes (CYPs) form one of the most important enzyme families involved in the metabolism of xenobiotics. CYPs comprise many isoforms, which catalyze a wide variety of reactions, and potentially, a large number of different metabolites can be formed. However, it is often hard...... to rationalize what metabolites these enzymes generate. In recent years, many different in silico approaches have been developed to predict binding or regioselective product formation for the different CYP isoforms. These comprise ligand-based methods that are trained on experimental CYP data and structure...

  9. Regulation of gap junction function and Connexin 43 expression by cytochrome P450 oxidoreductase (CYPOR)

    International Nuclear Information System (INIS)

    Polusani, Srikanth R.; Kar, Rekha; Riquelme, Manuel A.; Masters, Bettie Sue; Panda, Satya P.

    2011-01-01

    Highlights: → Humans with severe forms of cytochrome P450 oxidoreductase (CYPOR) mutations show bone defects as observed in Antley-Bixler Syndrome. → First report showing knockdown of CYPOR in osteoblasts decreased Connexin 43 (Cx43) protein levels. Cx43 is known to play an important role in bone modeling. → Knockdown of CYPOR decreased Gap Junctional Intercellular Communication and hemichannel activity. → Knockdown of CYPOR decreased Cx43 in mouse primary calvarial osteoblasts. → Decreased Cx43 expression was observed at the transcriptional level. -- Abstract: Cytochrome P450 oxidoreductase (CYPOR) is a microsomal electron-transferring enzyme containing both FAD and FMN as co-factors, which provides the reducing equivalents to various redox partners, such as cytochromes P450 (CYPs), heme oxygenase (HO), cytochrome b 5 and squalene monooxygenase. Human patients with severe forms of CYPOR mutation show bone defects such as cranio- and humeroradial synostoses and long bone fractures, known as Antley-Bixler-like Syndrome (ABS). To elucidate the role of CYPOR in bone, we knocked-down CYPOR in multiple osteoblast cell lines using RNAi technology. In this study, knock-down of CYPOR decreased the expression of Connexin 43 (Cx43), known to play a critical role in bone formation, modeling, and remodeling. Knock-down of CYPOR also decreased Gap Junction Intercellular Communication (GJIC) and hemichannel activity. Promoter luciferase assays revealed that the decrease in expression of Cx43 in CYPOR knock-down cells was due to transcriptional repression. Primary osteoblasts isolated from bone specific Por knock-down mice calvariae confirmed the findings in the cell lines. Taken together, our study provides novel insights into the regulation of gap junction function by CYPOR and suggests that Cx43 may play an important role(s) in CYPOR-mediated bone defects seen in patients.

  10. Regulation of gap junction function and Connexin 43 expression by cytochrome P450 oxidoreductase (CYPOR)

    Energy Technology Data Exchange (ETDEWEB)

    Polusani, Srikanth R.; Kar, Rekha; Riquelme, Manuel A.; Masters, Bettie Sue [The University of Texas Health Science Center at San Antonio, Department of Biochemistry, San Antonio, TX 78229 (United States); Panda, Satya P., E-mail: panda@uthscsa.edu [The University of Texas Health Science Center at San Antonio, Department of Biochemistry, San Antonio, TX 78229 (United States)

    2011-08-05

    Highlights: {yields} Humans with severe forms of cytochrome P450 oxidoreductase (CYPOR) mutations show bone defects as observed in Antley-Bixler Syndrome. {yields} First report showing knockdown of CYPOR in osteoblasts decreased Connexin 43 (Cx43) protein levels. Cx43 is known to play an important role in bone modeling. {yields} Knockdown of CYPOR decreased Gap Junctional Intercellular Communication and hemichannel activity. {yields} Knockdown of CYPOR decreased Cx43 in mouse primary calvarial osteoblasts. {yields} Decreased Cx43 expression was observed at the transcriptional level. -- Abstract: Cytochrome P450 oxidoreductase (CYPOR) is a microsomal electron-transferring enzyme containing both FAD and FMN as co-factors, which provides the reducing equivalents to various redox partners, such as cytochromes P450 (CYPs), heme oxygenase (HO), cytochrome b{sub 5} and squalene monooxygenase. Human patients with severe forms of CYPOR mutation show bone defects such as cranio- and humeroradial synostoses and long bone fractures, known as Antley-Bixler-like Syndrome (ABS). To elucidate the role of CYPOR in bone, we knocked-down CYPOR in multiple osteoblast cell lines using RNAi technology. In this study, knock-down of CYPOR decreased the expression of Connexin 43 (Cx43), known to play a critical role in bone formation, modeling, and remodeling. Knock-down of CYPOR also decreased Gap Junction Intercellular Communication (GJIC) and hemichannel activity. Promoter luciferase assays revealed that the decrease in expression of Cx43 in CYPOR knock-down cells was due to transcriptional repression. Primary osteoblasts isolated from bone specific Por knock-down mice calvariae confirmed the findings in the cell lines. Taken together, our study provides novel insights into the regulation of gap junction function by CYPOR and suggests that Cx43 may play an important role(s) in CYPOR-mediated bone defects seen in patients.

  11. The SMARTCyp cytochrome P450 metabolism prediction server

    DEFF Research Database (Denmark)

    Rydberg, Patrik; Gloriam, David Erik Immanuel; Olsen, Lars

    2010-01-01

    The SMARTCyp server is the first web application for site of metabolism prediction of cytochrome P450-mediated drug metabolism.......The SMARTCyp server is the first web application for site of metabolism prediction of cytochrome P450-mediated drug metabolism....

  12. Transgenic overexpression of p23 induces spontaneous hydronephrosis in mice

    Science.gov (United States)

    Lee, Jaehoon; Kim, Hye Jin; Moon, Jung Ah; Sung, Young Hoon; Baek, In-Jeoung; Roh, Jae-il; Ha, Na Young; Kim, Seung-Yeon; Bahk, Young Yil; Lee, Jong Eun; Yoo, Tae Hyun; Lee, Han-Woong

    2011-01-01

    p23 is a cochaperone of heat shock protein 90 and also interacts functionally with numerous steroid receptors and kinases. However, the in vivo roles of p23 remain unclear. To explore its in vivo function, we generated the transgenic (TG) mice ubiquitously overexpressing p23. The p23 TG mice spontaneously developed kidney abnormalities closely resembling human hydronephrosis. Consistently, kidney functions deteriorate significantly in the p23 TG mice compared to their wild-type (WT) littermates. Furthermore, the expression of target genes for aryl hydrocarbon receptor (AhR), such as cytochrome P450, family 1, subfamily A, polypeptide 1 (Cyp1A1) and cytochrome P450, family 1, subfamily B, polypeptide 1 (Cyp1B1), were induced in the kidneys of the p23 TG mice. These results indicate that the overexpression of p23 contributes to the development of hydronephrosis through the upregulation of the AhR pathway in vivo. PMID:21323770

  13. Lack of Glycogenin Causes Glycogen Accumulation and Muscle Function Impairment.

    Science.gov (United States)

    Testoni, Giorgia; Duran, Jordi; García-Rocha, Mar; Vilaplana, Francisco; Serrano, Antonio L; Sebastián, David; López-Soldado, Iliana; Sullivan, Mitchell A; Slebe, Felipe; Vilaseca, Marta; Muñoz-Cánoves, Pura; Guinovart, Joan J

    2017-07-05

    Glycogenin is considered essential for glycogen synthesis, as it acts as a primer for the initiation of the polysaccharide chain. Against expectations, glycogenin-deficient mice (Gyg KO) accumulate high amounts of glycogen in striated muscle. Furthermore, this glycogen contains no covalently bound protein, thereby demonstrating that a protein primer is not strictly necessary for the synthesis of the polysaccharide in vivo. Strikingly, in spite of the higher glycogen content, Gyg KO mice showed lower resting energy expenditure and less resistance than control animals when subjected to endurance exercise. These observations can be attributed to a switch of oxidative myofibers toward glycolytic metabolism. Mice overexpressing glycogen synthase in the muscle showed similar alterations, thus indicating that this switch is caused by the excess of glycogen. These results may explain the muscular defects of GSD XV patients, who lack glycogenin-1 and show high glycogen accumulation in muscle. Copyright © 2017 Elsevier Inc. All rights reserved.

  14. Cytochrome P450-Mediated Phytoremediation using Transgenic Plants: A Need for Engineered Cytochrome P450 Enzymes

    OpenAIRE

    Kumar, Santosh; Jin, Mengyao; Weemhoff, James L

    2012-01-01

    There is an increasing demand for versatile and ubiquitous Cytochrome P450 (CYP) biocatalysts for biotechnology, medicine, and bioremediation. In the last decade there has been an increase in realization of the power of CYP biocatalysts for detoxification of soil and water contaminants using transgenic plants. However, the major limitations of mammalian CYP enzymes are that they require CYP reductase (CPR) for their activity, and they show relatively low activity, stability, and expression. O...

  15. NMR comparison of prokaryotic and eukaryotic cytochromes c

    International Nuclear Information System (INIS)

    Chau, Meihing; Cai, Meng Li; Timkovich, R.

    1990-01-01

    1 H NMR spectroscopy has been used to examine ferrocytochrome c-551 from Pseudomonas aeruginosa (ATCC 19429) over the pH range 3.5-10.6 and the temperature range 4-60 degree C. Resonance assignments are proposed for main-chain and side-chain protons. Comparison of results for cytochrome c-551 to recently assigned spectra for horse cytochrome c and mutants of yeast iso-1 cytochrome reveals some unique resonances with unusual chemical shifts in all cytochromes that may serve as markers for the heme region. Results for cytochrome c-551 indicate that in the smaller prokaryotic cytochrome, all benzoid side chains are rapidly flipping on the NMR time scale. In contrast, in eukaryotic cytochromes there are some rings flipping slowly on the NMR time scale. The ferrocytochrome c-551 undergoes a transition linked to pH with a pK around 7. The pH behavior of assigned resonances provides evidence that the site of protonation is the inner or buried 17-propionic acid heme substituent (IUPAC-IUB porphyrin nomenclature). Conformational heterogeneity has been observed for segments near the inner heme propionate substituent

  16. Calcium transport in vesicles energized by cytochrome oxidase

    Energy Technology Data Exchange (ETDEWEB)

    Rosier, Randy N. [Univ. of Rochester, NY (United States)

    1979-01-01

    Experiments on the reconstitution of cytochrome oxidase into phospholipid vesicles were carried out using techniques of selectivity energizing the suspensions with ascorbate and cytochrome c or ascorbate, PMS, and internally trapped cytochrome c. It was found that the K+ selective ionophore valinomycin stimulated the rate of respiration of cytochrome oxidase vesicles regardless of the direction of the K+ flux across the vesicle membranes. The stimulation occurred in the presence of protonophoric uncouplers and in the complete absence of potassium or in detergent-lysed suspensions. Gramicidin had similar effects and it was determined that the ionophores acted by specific interaction with cytochrome oxidase rather than by the previously assumed collapse of membrane potentials. When hydrophobic proteins and appropriate coupling factors were incorporated into the cytochrome oxidase, vesicles phosphorylation of ADP could be coupled to the oxidation reaction of cytochrome oxidase. Relatively low P:O, representing poor coupling of the system, were problematical and precluded measurements of protonmotive force. However the system was used to study ion translocation.

  17. Biogenesis of the yeast cytochrome bc1 complex.

    Science.gov (United States)

    Zara, Vincenzo; Conte, Laura; Trumpower, Bernard L

    2009-01-01

    The mitochondrial respiratory chain is composed of four different protein complexes that cooperate in electron transfer and proton pumping across the inner mitochondrial membrane. The cytochrome bc1 complex, or complex III, is a component of the mitochondrial respiratory chain. This review will focus on the biogenesis of the bc1 complex in the mitochondria of the yeast Saccharomyces cerevisiae. In wild type yeast mitochondrial membranes the major part of the cytochrome bc1 complex was found in association with one or two copies of the cytochrome c oxidase complex. The analysis of several yeast mutant strains in which single genes or pairs of genes encoding bc1 subunits had been deleted revealed the presence of a common set of bc1 sub-complexes. These sub-complexes are represented by the central core of the bc1 complex, consisting of cytochrome b bound to subunit 7 and subunit 8, by the two core proteins associated with each other, by the Rieske protein associated with subunit 9, and by those deriving from the unexpected interaction of each of the two core proteins with cytochrome c1. Furthermore, a higher molecular mass sub-complex is that composed of cytochrome b, cytochrome c1, core protein 1 and 2, subunit 6, subunit 7 and subunit 8. The identification and characterization of all these sub-complexes may help in defining the steps and the molecular events leading to bc1 assembly in yeast mitochondria.

  18. Editor's Highlight: Complete Attenuation of Mouse Lung Cell Proliferation and Tumorigenicity in CYP2F2 Knockout and CYP2F1 Humanized Mice Exposed to Inhaled Styrene for up to 2 Years Supports a Lack of Human Relevance.

    Science.gov (United States)

    Cruzan, George; Bus, James S; Banton, Marcy I; Sarang, Satinder S; Waites, Robbie; Layko, Debra B; Raymond, James; Dodd, Darol; Andersen, Melvin E

    2017-10-01

    Styrene is a mouse-specific lung carcinogen, and short-term mode of action studies have demonstrated that cytotoxicity and/or cell proliferation, and genomic changes are dependent on CYP2F2 metabolism. The current study examined histopathology, cell proliferation, and genomic changes in CD-1, C57BL/6 (WT), CYP2F2(-/-) (KO), and CYP2F2(-/-) (CYP2F1, 2B6, 2A13-transgene) (TG; humanized) mice following exposure for up to 104 weeks to 0- or 120-ppm styrene vapor. Five mice per treatment group were sacrificed at 1, 26, 52, and 78 weeks. Additional 50 mice per treatment group were followed until death or 104 weeks of exposure. Cytotoxicity was present in the terminal bronchioles of some CD-1 and WT mice exposed to styrene, but not in KO or TG mice. Hyperplasia in the terminal bronchioles was present in CD-1 and WT mice exposed to styrene, but not in KO or TG mice. Increased cell proliferation, measured by KI-67 staining, occurred in CD-1 and WT mice exposed to styrene for 1 week, but not after 26, 52, or 78 weeks, nor in KO or TG mice. Styrene increased the incidence of bronchioloalveolar adenomas and carcinomas in CD-1 mice. No increase in lung tumors was found in WT despite clear evidence of lung toxicity, or, KO or TG mice. The absence of preneoplastic lesions and tumorigenicity in KO and TG mice indicates that mouse-specific CYP2F2 metabolism is responsible for both the short-term and chronic toxicity and tumorigenicity of styrene, and activation of styrene by CYP2F2 is a rodent MOA that is neither quantitatively or qualitatively relevant to humans. © The Author 2017. Published by Oxford University Press on behalf of the Society of Toxicology. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  19. Control of electron transfer in the cytochrome system of mitochondria by pH, transmembrane pH gradient and electrical potential. The cytochromes b-c segment.

    Science.gov (United States)

    Papa, S; Lorusso, M; Izzo, G; Capuano, F

    1981-02-15

    1. A study is presented of the effects of pH, transmembrane pH gradient and electrical potential on oxidoreductions of b and c cytochromes in ox heart mitochondria and 'inside-out' submitochondrial particles. 2. Kinetic analysis shows that, in mitochondria at neutral pH, there is a restraint on the aerobic oxidation of cytochrome b566 with respect to cytochrome b562. Valinomycin plus K+ accelerates cytochrome b566 oxidation and retards net oxidation of cytochrome b562. At alkaline pH the rate of cytochrome b566 oxidation approaches that of cytochrome b562 and the effects of valinomycin on b cytochromes are impaired. 3. At slightly acidic pH, oxygenation of antimycin-supplemented mitochondria causes rapid reduction of cytochrome b566 and small delayed reduction of cytochrome b562. Valinomycin or a pH increase in the medium promote reduction of cytochrome b562 and decrease net reduction of cytochrome b566. 4. Addition of valinomycin to mitochondria and submitochondrial particles in the respiring steady state causes, at pH values around neutrality, preferential oxidation of cytochrome b566 with respect to cytochrome b562. The differential effect of valinomycin on oxidation of cytochromes b566 and b562 is enhanced by substitution of 1H2O of the medium with 2H2O and tends to disappear as the pH of the medium is raised to alkaline values. 5. Nigericin addition in the aerobic steady state causes, both in mitochondria and submitochondrial particles, preferential oxidation of cytochrome b562 with respect to cytochrome b566. This is accompanied by c cytochrome oxidation in mitochondria but c cytochrome reduction in submitochondrial particles. 6. In mitochondria as well as in submitochondrial particles, the aerobic transmembrane potential (delta psi) does not change by raising the pH of the external medium from neutrality to alkalinity. The transmembrane pH gradient (delta pH) on the other hand, decrease slightly. 7. The results presented provide evidence that the delta psi

  20. Plastocyanin/cytochrome c6 interchange in Scenedesmus vacuolatus.

    Science.gov (United States)

    Miramar, M Dolores; Inda, Luis A; Saraiva, Lígia M; Peleato, M Luisa

    2003-12-01

    Plastocyanin and cytochrome c6 from the green alga Scenedesmus vacuolatus were immunoquantified in cells grown under different concentrations of copper and iron. Plastocyanin expression was constitutive, its synthesis was not significantly affected by iron availability, and increases with copper availability. On the contrary, cytochrome c6 synthesis is repressed by copper, and only residual amounts of the protein were detected at 0.1 micromol/L copper. Under copper deficiency, cytochrome c6 is slightly dependent on iron. In natural environments, plastocyanin seems to be the predominant electron donor to P700.

  1. The dimerization of the yeast cytochrome bc1 complex is an early event and is independent of Rip1.

    Science.gov (United States)

    Conte, Annalea; Papa, Benedetta; Ferramosca, Alessandra; Zara, Vincenzo

    2015-05-01

    In Saccharomyces cerevisiae the mature cytochrome bc1 complex exists as an obligate homo-dimer in which each monomer consists of ten distinct protein subunits inserted into or bound to the inner mitochondrial membrane. Among them, the Rieske iron-sulfur protein (Rip1), besides its catalytic role in electron transfer, may be implicated in the bc1 complex dimerization. Indeed, Rip1 has the globular domain containing the catalytic center in one monomer while the transmembrane helix interacts with the adjacent monomer. In addition, the lack of Rip1 leads to the accumulation of an immature bc1 intermediate, only loosely associated with cytochrome c oxidase. In this study we have investigated the biogenesis of the yeast cytochrome bc1 complex using epitope tagged proteins to purify native assembly intermediates. We showed that the dimerization process is an early event during bc1 complex biogenesis and that the presence of Rip1, differently from previous proposals, is not essential for this process. We also investigated the multi-step model of bc1 assembly thereby lending further support to the existence of bona fide subcomplexes during bc1 maturation in the inner mitochondrial membrane. Finally, a new model of cytochrome bc1 complex assembly, in which distinct intermediates sequentially interact during bc1 maturation, has been proposed. Copyright © 2015 Elsevier B.V. All rights reserved.

  2. Ethanol metabolism, oxidative stress, and endoplasmic reticulum stress responses in the lungs of hepatic alcohol dehydrogenase deficient deer mice after chronic ethanol feeding

    Energy Technology Data Exchange (ETDEWEB)

    Kaphalia, Lata [Department of Internal Medicine, The University of Texas Medical Branch, Galveston, TX 775555 (United States); Boroumand, Nahal [Department of Pathology, The University of Texas Medical Branch, Galveston, TX 775555 (United States); Hyunsu, Ju [Department of Preventive Medicine and Community Health, The University of Texas Medical Branch, Galveston, TX 775555 (United States); Kaphalia, Bhupendra S., E-mail: bkaphali@utmb.edu [Department of Pathology, The University of Texas Medical Branch, Galveston, TX 775555 (United States); Calhoun, William J. [Department of Internal Medicine, The University of Texas Medical Branch, Galveston, TX 775555 (United States)

    2014-06-01

    Consumption and over-consumption of alcoholic beverages are well-recognized contributors to a variety of pulmonary disorders, even in the absence of intoxication. The mechanisms by which alcohol (ethanol) may produce disease include oxidative stress and prolonged endoplasmic reticulum (ER) stress. Many aspects of these processes remain incompletely understood due to a lack of a suitable animal model. Chronic alcohol over-consumption reduces hepatic alcohol dehydrogenase (ADH), the principal canonical metabolic pathway of ethanol oxidation. We therefore modeled this situation using hepatic ADH-deficient deer mice fed 3.5% ethanol daily for 3 months. Blood ethanol concentration was 180 mg% in ethanol fed mice, compared to < 1.0% in the controls. Acetaldehyde (oxidative metabolite of ethanol) was minimally, but significantly increased in ethanol-fed vs. pair-fed control mice. Total fatty acid ethyl esters (FAEEs, nonoxidative metabolites of ethanol) were 47.6 μg/g in the lungs of ethanol-fed mice as compared to 1.5 μg/g in pair-fed controls. Histological and immunohistological evaluation showed perivascular and peribronchiolar lymphocytic infiltration, and significant oxidative injury, in the lungs of ethanol-fed mice compared to pair-fed controls. Several fold increases for cytochrome P450 2E1, caspase 8 and caspase 3 found in the lungs of ethanol-fed mice as compared to pair-fed controls suggest role of oxidative stress in ethanol-induced lung injury. ER stress and unfolded protein response signaling were also significantly increased in the lungs of ethanol-fed mice. Surprisingly, no significant activation of inositol-requiring enzyme-1α and spliced XBP1 was observed indicating a lack of activation of corrective mechanisms to reinstate ER homeostasis. The data suggest that oxidative stress and prolonged ER stress, coupled with formation and accumulation of cytotoxic FAEEs may contribute to the pathogenesis of alcoholic lung disease. - Highlights: • Chronic

  3. Ethanol metabolism, oxidative stress, and endoplasmic reticulum stress responses in the lungs of hepatic alcohol dehydrogenase deficient deer mice after chronic ethanol feeding

    International Nuclear Information System (INIS)

    Kaphalia, Lata; Boroumand, Nahal; Hyunsu, Ju; Kaphalia, Bhupendra S.; Calhoun, William J.

    2014-01-01

    Consumption and over-consumption of alcoholic beverages are well-recognized contributors to a variety of pulmonary disorders, even in the absence of intoxication. The mechanisms by which alcohol (ethanol) may produce disease include oxidative stress and prolonged endoplasmic reticulum (ER) stress. Many aspects of these processes remain incompletely understood due to a lack of a suitable animal model. Chronic alcohol over-consumption reduces hepatic alcohol dehydrogenase (ADH), the principal canonical metabolic pathway of ethanol oxidation. We therefore modeled this situation using hepatic ADH-deficient deer mice fed 3.5% ethanol daily for 3 months. Blood ethanol concentration was 180 mg% in ethanol fed mice, compared to < 1.0% in the controls. Acetaldehyde (oxidative metabolite of ethanol) was minimally, but significantly increased in ethanol-fed vs. pair-fed control mice. Total fatty acid ethyl esters (FAEEs, nonoxidative metabolites of ethanol) were 47.6 μg/g in the lungs of ethanol-fed mice as compared to 1.5 μg/g in pair-fed controls. Histological and immunohistological evaluation showed perivascular and peribronchiolar lymphocytic infiltration, and significant oxidative injury, in the lungs of ethanol-fed mice compared to pair-fed controls. Several fold increases for cytochrome P450 2E1, caspase 8 and caspase 3 found in the lungs of ethanol-fed mice as compared to pair-fed controls suggest role of oxidative stress in ethanol-induced lung injury. ER stress and unfolded protein response signaling were also significantly increased in the lungs of ethanol-fed mice. Surprisingly, no significant activation of inositol-requiring enzyme-1α and spliced XBP1 was observed indicating a lack of activation of corrective mechanisms to reinstate ER homeostasis. The data suggest that oxidative stress and prolonged ER stress, coupled with formation and accumulation of cytotoxic FAEEs may contribute to the pathogenesis of alcoholic lung disease. - Highlights: • Chronic

  4. Cytochrome c Is Tyrosine 97 Phosphorylated by Neuroprotective Insulin Treatment

    Czech Academy of Sciences Publication Activity Database

    Sanderson, T. H.; Mahapatra, G.; Pecina, Petr; Ji, Q.; Yu, K.; Sinkler, Ch.; Varughese, A.; Kumar, R.; Bukowski, M. J.; Tousignant, R. N.; Salomon, A. R.; Lee, I.; Hüttemann, M.

    2013-01-01

    Roč. 8, č. 11 (2013), e78627 E-ISSN 1932-6203 Institutional support: RVO:67985823 Keywords : cytochrome c * tyrosine phosphorylation * brain ischemia * insulin Subject RIV: ED - Physiology Impact factor: 3.534, year: 2013

  5. North African genetic variation of cytochrome and sulfotransferase ...

    African Journals Online (AJOL)

    in these genes have shown relevant ethnic differences among Sub-Saharan .... This cytochrome catalyzes a big amount of oxidative reactions of substances like ... with samples of European and African origin (because of the scarce data ...

  6. Isolation and purification of membrane-bound cytochrome c from ...

    African Journals Online (AJOL)

    Administrator

    2007-05-02

    ferrochrome and redox spectra showed the presence of heme-c. Key words: Cytochrome c, respiratory chain and Proteus mirabilis. INTRODUCTION. Proteus mirabilis is facultative anaerobic, rod-shaped, gram negative bacterium.

  7. Oxygen and xenobiotic reductase activities of cytochrome P450.

    NARCIS (Netherlands)

    Goeptar, A.R.; Scheerens, H.; Vermeulen, N.P.E.

    1995-01-01

    The oxygen reductase and xenobiotic reductase activities of cytochrome P450 (P450) are reviewed. During the oxygen reductase activity of P450, molecular oxygen is reduced to superoxide anion radicals (O

  8. The biodiversity of microbial cytochromes P450.

    Science.gov (United States)

    Kelly, Steven L; Lamb, David C; Jackson, Colin J; Warrilow, Andrew G; Kelly, Diane E

    2003-01-01

    The cytochrome P450 (CYP) superfamily of genes and proteins are well known for their involvement in pharmacology and toxicology, but also increasingly for their importance and diversity in microbes. The extent of diversity has only recently become apparent with the emergence of data from whole genome sequencing projects and the coming years will reveal even more information on the diversity in microbial eukaryotes. This review seeks to describe the historical development of these studies and to highlight the importance of the genes and proteins. CYPs are deeply involved in the development of strategies for deterrence and attraction as well as detoxification. As such, there is intense interest in pathways of secondary metabolism that include CYPs in oxidative tailoring of antibiotics, sometimes influencing potency as bioactive compounds. Further to this is interest in CYPs in metabolism of xenobiotics for use as carbon sources for microbial growth and as biotransformation agents or in bioremediation. CYPs are also current and potential drug targets; compounds inhibiting CYP are antifungal and anti-protozoan agents, and potentially similar compounds may be useful against some bacterial diseases such as tuberculosis. Of note is the diversity of CYP requirements within an organism, ranging from Escherichia coli that has no CYPs as in many bacteria, to Mycobacterium smegmatis that has 40 representing 1% of coding genes. The basidiomycete fungus Phanerochaete chrysosporium surprised all when it was found to contain a hundred or more CYPs. The functional genomic investigation of these orphan CYPs is a major challenge for the future.

  9. Geometrical analysis of cytochrome c unfolding

    Science.gov (United States)

    Urie, Kristopher G.; Pletneva, Ekaterina; Gray, Harry B.; Winkler, Jay R.; Kozak, John J.

    2011-01-01

    A geometrical model has been developed to study the unfolding of iso-1 cytochrome c. The model draws on the crystallographic data reported for this protein. These data were used to calculate the distance between specific residues in the folded state, and in a sequence of extended states defined by n = 3, 5, 7, 9, 11, 13, and 15 residue units. Exact calculations carried out for each of the 103 residues in the polypeptide chain demonstrate that different regions of the chain have different unfolding histories. Regions where there is a persistence of compact structures can be identified, and this geometrical characterization is fully consistent with analyses of time-resolved fluorescence energy-transfer (TrFET) data using dansyl-derivatized cysteine side-chain probes at positions 39, 50, 66, 85, and 99. The calculations were carried out assuming that different regions of the polypeptide chain unfold synchronously. To test this assumption, lattice Monte Carlo simulations were performed to study systematically the possible importance of asynchronicity. Calculations show that small departures from synchronous dynamics can arise if displacements of residues in the main body of the chain are much more sluggish than near-terminal residues.

  10. Epidermal CYP2 family cytochromes P450

    International Nuclear Information System (INIS)

    Du Liping; Hoffman, Susan M.G.; Keeney, Diane S.

    2004-01-01

    Skin is the largest and most accessible drug-metabolizing organ. In mammals, it is the competent barrier that protects against exposure to harmful stimuli in the environment and in the systemic circulation. Skin expresses many cytochromes P450 that have critical roles in exogenous and endogenous substrate metabolism. Here, we review evidence for epidermal expression of genes from the large CYP2 gene family, many of which are expressed preferentially in extrahepatic tissues or specifically in epithelia at the environmental interface. At least 13 CYP2 genes (CYP2A6, 2A7, 2B6, 2C9, 2C18, 2C19, 2D6, 2E1, 2J2, 2R1, 2S1, 2U1, and 2W1) are expressed in skin from at least some human individuals, and the majority of these genes are expressed in epidermis or cultured keratinocytes. Where epidermal expression has been localized in situ by hybridization or immunocytochemistry, CYP2 transcripts and proteins are most often expressed in differentiated keratinocytes comprising the outer (suprabasal) cell layers of the epidermis and skin appendages. The tissue-specific transcriptional regulation of CYP2 genes in the epidermis, and in other epithelia that interface with the environment, suggests important roles for at least some CYP2 gene products in the production and disposition of molecules affecting competency of the epidermal barrier

  11. Novel extrahepatic cytochrome P450s

    International Nuclear Information System (INIS)

    Karlgren, Maria; Miura, Shin-ichi; Ingelman-Sundberg, Magnus

    2005-01-01

    The cytochrome P450 enzymes are highly expressed in the liver and are involved in the metabolism of xenobiotics. Because of the initiatives associated with the Human Genome Project, a great progress has recently been seen in the identification and characterization of novel extrahepatic P450s, including CYP2S1, CYP2R1, CYP2U1 and CYP2W1. Like the hepatic enzymes, these P450s may play a role in the tissue-specific metabolism of foreign compounds, but they may also have important endogenous functions. CYP2S1 has been shown to metabolize all-trans retinoic acid and CYP2R1 is a major vitamin D 25-hydroxylase. Regarding their metabolism of xenobiotics, much remains to be established, but CYP2S1 metabolizes naphthalene and it is likely that these P450s are responsible for metabolic activation of several different kinds of xenobiotic chemicals and contribute to extrahepatic toxicity and carcinogenesis

  12. Polyethylene glycol promotes autoxidation of cytochrome c.

    Science.gov (United States)

    Sato, Wataru; Uchida, Takeshi; Saio, Tomohide; Ishimori, Koichiro

    2018-06-01

    Cytochrome c (Cyt c) was rapidly oxidized by molecular oxygen in the presence, but not absence of PEG. The redox potential of heme c was determined by the potentiometric titration to be +236 ± 3 mV in the absence of PEG, which was negatively shifted to +200 ± 4 mV in the presence of PEG. The underlying the rapid oxidation was explored by examining the structural changes in Cyt c in the presence of PEG using UV-visible absorption, circular dichroism, resonance Raman, and fluorescence spectroscopies. These spectroscopic analyses suggested that heme oxidation was induced by a modest tertiary structural change accompanied by a slight shift in the heme position (c, which triggered heme displacement. The primary dehydration site was estimated to be around surface-exposed hydrophobic residues near the heme center: Ile81 and Val83. These findings and our previous studies, which showed that hydrated water molecules around Ile81 and Val83 are expelled when Cyt c forms a complex with CcO, proposed that dehydration of these residues is functionally significant to electron transfer from Cyt c to CcO. Copyright © 2018 Elsevier B.V. All rights reserved.

  13. Differential androgenesis in gamma irradiated mice

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jihyang; Yoon, Yongdal [Hanyang Univ., Seoul (Korea, Republic of); Kim, Jin Kyu [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    2002-07-01

    The Leydig cells of the testis account for at least 75% of the total testosterone produced in the normal adult male. Whereas the production of estrogen from androgen is catalyzed by aromatase cytochrome P450, which is found in many tissues, including gonad, brain, adipose tissue, bone, and heart. The gamma-irradiation causes the impairment of spermatogenesis and steroidogenesis in male mice. The present study was performed to analyze changes in testosterone concentrations and expression of steroidogenic enzyme of mice after whole body gamma-irradiation. Eight-week-old male ICR mice were irradiated with 6.5 or 10 Gy. At days 1, 2, 3, 4, and 5 after irradiation, testes were removed and processed for paraffin sections and isolation of mRNA. We calculated the gonad index from body and testis weight, and checked the testis volume. Hormonal analysis was performed by means of radioimmunoassay (RIA) in serum and intratesticular fluid. Semiquantitative reverse transcription polymerase chain reaction (RT-PCR) was used to evaluate the expression kinetics of the apoptotic gene and the cytochrome P450 aromatase gene after irradiation. In gamma-irradiated mice, the body weight reduced in comparison to that of the control group. Therefore, gonad indices increased. The testosterone concentrations in serum and intratesticular fluid were significantly reduced. RT- PCR data represented that the expression of Fas, Fas ligand, and aromatase cytochrome P450 showed the specific patterns against control groups. These results indicated that gamma- irradiation of adult mice induced the alteration of androgenesis and suggested that might counteract the spermatogenesis.

  14. Lack of RNase L attenuates macrophage functions.

    Directory of Open Access Journals (Sweden)

    Xin Yi

    Full Text Available Macrophages are one of the major cell types in innate immunity against microbial infection. It is believed that the expression of proinflammatory genes such as tumor necrosis factor-α (TNF-α, interleukin (IL-1β, IL-6, and cyclooxygenase-2 (Cox-2 by macrophages is also crucial for activation of both innate and adaptive immunities. RNase L is an interferon (IFN inducible enzyme which is highly expressed in macrophages. It has been demonstrated that RNase L regulates the expression of certain inflammatory genes. However, its role in macrophage function is largely unknown.Bone marrow-derived macrophages (BMMs were generated from RNase L(+/+and (-/- mice. The migration of BMMs was analyzed by using Transwell migration assays. Endocytosis and phagocytosis of macrophages were assessed by using fluorescein isothiocyanate (FITC-Dextran 40,000 and FITC-E. coli bacteria, respectively. The expression of inflammatory genes was determined by Western Blot and ELISA. The promoter activity of Cox-2 was measured by luciferase reporter assays.Lack of RNase L significantly decreased the migration of BMMs induced by M-CSF, but at a less extent by GM-CSF and chemokine C-C motif ligand-2 (CCL2. Interestingly, RNase L deficient BMMs showed a significant reduction of endocytic activity to FITC-Dextran 40,000, but no any obvious effect on their phagocytic activity to FITC-bacteria under the same condition. RNase L impacts the expression of certain genes related to cell migration and inflammation such as transforming growth factor (TGF-β, IL-1β, IL-10, CCL2 and Cox-2. Furthermore, the functional analysis of the Cox-2 promoter revealed that RNase L regulated the expression of Cox-2 in macrophages at its transcriptional level. Taken together, our findings provide direct evidence showing that RNase L contributes to innate immunity through regulating macrophage functions.

  15. Lack of Neuronal IFN-β-IFNAR Causes Lewy Body- and Parkinson's Disease-like Dementia

    DEFF Research Database (Denmark)

    Ejlerskov, Patrick; Hultberg, Jeanette Göransdotter; Wang, JunYang

    2015-01-01

    -causing mutant proteins. Mice lacking Ifnb function exhibited motor and cognitive learning impairments with accompanying α-synuclein-containing Lewy bodies in the brain, as well as a reduction in dopaminergic neurons and defective dopamine signaling in the nigrostriatal region. Lack of IFN-β signaling caused...

  16. Characterization of vitamin D-deficient klotho(-/-) mice: do increased levels of serum 1,25(OH)2D3 cause disturbed calcium and phosphate homeostasis in klotho(-/-) mice?

    NARCIS (Netherlands)

    Woudenberg-Vrenken, T.E.; van der Eerden, B.C.; van der Kemp, A.W.; Leeuwen, J.P. van; Bindels, R.J.M.; Hoenderop, J.G.J.

    2012-01-01

    BACKGROUND: Klotho(-/-) mice display disturbed Ca(2+) and vitamin D homeostasis. Renal cytochrome p450 27b1 (Cyp27b1), the enzyme that catalyzes the hydrolysis to 1,25-dihydroxyvitamin D(3) (1,25(OH)(2)D(3)), is increased in klotho(-/-) mice, and a 1,25(OH)(2)D(3)-deficient diet partially normalized

  17. Synthesis of ¹³C-lidocaine as a probe of breath test for the evaluation of cytochrome P450 activity.

    Science.gov (United States)

    Mitome, Hidemichi; Sugiyama, Erika; Sato, Hitoshi; Akira, Kazuki

    2014-01-01

    (13)C-Labeled lidocaine, 2-di[1-(13)C]ethylamino-N-(2,6-dimethylphenyl)acetamide (1), was synthesized from [1-(13)C]acetic acid in six steps, as a probe for a breath test to evaluate in vivo cytochrome P450 activity. The measurement of (13)CO2 in breath was successfully performed following oral administration of (13)C-lidocaine 1 to mice.

  18. Cytochrome b5 and NADH cytochrome b5 reductase: genotype-phenotype correlations for hydroxylamine reduction.

    Science.gov (United States)

    Sacco, James C; Trepanier, Lauren A

    2010-01-01

    NADH cytochrome b5 reductase (b5R) and cytochrome b5 (b5) catalyze the reduction of sulfamethoxazole hydroxylamine (SMX-HA), which can contribute to sulfonamide hypersensitivity, to the parent drug sulfamethoxazole. Variability in hydroxylamine reduction could thus play a role in adverse drug reactions. The aim of this study was to characterize variability in SMX-HA reduction in 111 human livers, and investigate its association with single nucleotide polymorphisms (SNPs) in b5 and b5R cDNA. Liver microsomes were assayed for SMX-HA reduction activity, and b5 and b5R expression was semiquantified by immunoblotting. The coding regions of the b5 (CYB5A) and b5R (CYB5R3) genes were resequenced. Hepatic SMX-HA reduction displayed a 19-fold range of individual variability (0.06-1.11 nmol/min/mg protein), and a 17-fold range in efficiency (Vmax/Km) among outliers. SMX-HA reduction was positively correlated with b5 and b5R protein content (Phydroxylamine reduction activities, these low-frequency cSNPs seem to only minimally impact overall observed phenotypic variability. Work is underway to characterize polymorphisms in other regions of these genes to further account for individual variability in hydroxylamine reduction.

  19. Solution NMR study of the yeast cytochrome c peroxidase: cytochrome c interaction

    Energy Technology Data Exchange (ETDEWEB)

    Volkov, Alexander N., E-mail: ovolkov@vub.ac.be; Nuland, Nico A. J. van [Vrije Universiteit Brussel, Jean Jeener NMR Centre, Structural Biology Brussels (Belgium)

    2013-07-15

    Here we present a solution NMR study of the complex between yeast cytochrome c (Cc) and cytochrome c peroxidase (CcP), a paradigm for understanding the biological electron transfer. Performed for the first time, the CcP-observed heteronuclear NMR experiments were used to probe the Cc binding in solution. Combining the Cc- and CcP-detected experiments, the binding interface on both proteins was mapped out, confirming that the X-ray structure of the complex is maintained in solution. Using NMR titrations and chemical shift perturbation analysis, we show that the interaction is independent of the CcP spin-state and is only weakly affected by the Cc redox state. Based on these findings, we argue that the complex of the ferrous Cc and the cyanide-bound CcP is a good mimic of the catalytically-active Cc-CcP compound I species. Finally, no chemical shift perturbations due to the Cc binding at the low-affinity CcP site were observed at low ionic strength. We discuss possible reasons for the absence of the effects and outline future research directions.

  20. Production and characterization of yeast cytochrome c antibodies; immunological studies of mutants with altered cytochrome c synthesis

    International Nuclear Information System (INIS)

    Matner, R.R.

    1980-01-01

    Mutations at the structural gene, CYC1, for iso-1-cytochrome c and at the structural gene, CYC7, for iso-2-cytochrome c can reduce the levels of the respective proteins by varying degrees in Saccharomyces cerevisiae. Mutations at two other loci, cyc2 and cyc3, that are unlinked to either of the structural genes, specifically reduced the levels of both iso-cytochromes c. The cyc2 mutations can cause as low as 10 to 20% of the normal level and cyc3 mutations can cause complete deficiencies. We have explored the possiblity that the CYC2 and CYC3 loci code for maturation functions in the biosynthesis of cytochrome c. The approach used to characterize the nature of the cyc2 and cyc3 induced deficiencies of cytochrome c involved four steps. The results were used to propose possible roles for the CYC2 and CYC3 encoded functions. The CYC3 encoded function is hypothesized to be enzymatic heme attachment. CYC2 may code for a protein that binds and transports apo-cytochrome c through the outer mitochondrial membrane and/or enhances the activity of the heme attachment enzyme

  1. Cytochrome P450s and molecular epidemiology

    Science.gov (United States)

    Gonzalez, Frank J.; Gelboin, Harry V.

    1993-03-01

    Cytochrome P450 (P450) represent a superfamily of heme-containing monooxygenases that are found throughout the animal and plant kingdoms and in many microorganisms. A number of these enzymes are involved in biosynthetic pathways of steroid synthesis but in mammals the vast majority of P450s function to metabolize foreign chemicals or xenobiotics. In the classical phase I reactions on the latter, a membrane-bound P450 will hydroxylate a compound, usually hydrophobic in nature, and the hydroxyl group will serve as a substrate for the various transferases or phase II enzymes that attach hydrophilic substituents such as glutathione, sulfate or glucuronic acid. Some chemicals, however, are metabolically-activated by P450s to electrophiles capable of reacting with cellular macromolecules. The cellular concentrations of the chemical and P450, reactivity of the active metabolite with nucleic acid and the repairability of the resultant adducts, in addition to the nature of the cell type, likely determines whether a chemical will be toxic and kill the cell or will transform the cell. Immunocorrelative and cDNA-directed expression have been used to define the substrate specificities of numerous human P450s. Levels of expression of different human P450 forms have been measured by both in vivo and in vitro methodologies leading to the realization that a large degree of interindividual differences occur in P450 expression. Reliable procedures for measuring P450 expression in healthy and diseased subjects will lead to prospective and case- cohort studies to determine whether interindividual differences in levels of P450 are associated with susceptibility or resistance to environmentally-based disease.

  2. Cytochrome b5 reductase is the component from neuronal synaptic plasma membrane vesicles that generates superoxide anion upon stimulation by cytochrome c

    Directory of Open Access Journals (Sweden)

    Alejandro K. Samhan-Arias

    2018-05-01

    Full Text Available In this work, we measured the effect of cytochrome c on the NADH-dependent superoxide anion production by synaptic plasma membrane vesicles from rat brain. In these membranes, the cytochrome c stimulated NADH-dependent superoxide anion production was inhibited by antibodies against cytochrome b5 reductase linking the production to this enzyme. Measurement of the superoxide anion radical generated by purified recombinant soluble and membrane cytochrome b5 reductase corroborates the production of the radical by different enzyme isoforms. In the presence of cytochrome c, a burst of superoxide anion as well as the reduction of cytochrome c by cytochrome b5 reductase was measured. Complex formation between both proteins suggests that cytochrome b5 reductase is one of the major partners of cytochrome c upon its release from mitochondria to the cytosol during apoptosis. Superoxide anion production and cytochrome c reduction are the consequences of the stimulated NADH consumption by cytochrome b5 reductase upon complex formation with cytochrome c and suggest a major role of this enzyme as an anti-apoptotic protein during cell death.

  3. Mass spectrometry-based proteomic analysis of human liver cytochrome(s) P450

    Energy Technology Data Exchange (ETDEWEB)

    Shrivas, Kamlesh; Mindaye, Samuel T.; Getie-Kebtie, Melkamu; Alterman, Michail A., E-mail: Michail.Alterman@fda.hhs.gov

    2013-02-15

    The major objective of personalized medicine is to select optimized drug therapies and to a large degree such mission is determined by the expression profiles of cytochrome(s) P450 (CYP). Accordingly, a proteomic case study in personalized medicine is provided by the superfamily of cytochromes P450. Our knowledge about CYP isozyme expression on a protein level is very limited and based exclusively on DNA/mRNA derived data. Such information is not sufficient because transcription and translation events do not lead to correlated levels of expressed proteins. Here we report expression profiles of CYPs in human liver obtained by mass spectrometry (MS)-based proteomic approach. We analyzed 32 samples of human liver microsomes (HLM) of different sexes, ages and ethnicity along with samples of recombinant human CYPs. We have experimentally confirmed that each CYP isozyme can be effectively differentiated by their unique isozyme-specific tryptic peptide(s). Trypsin digestion patterns for almost 30 human CYP isozymes were established. Those findings should assist in selecting tryptic peptides suitable for MS-based quantitation. The data obtained demonstrate remarkable differences in CYP expression profiles. CYP2E1, CYP2C8 and CYP4A11 were the only isozymes found in all HLM samples. Female and pediatric HLM samples revealed much more diverse spectrum of expressed CYPs isozymes compared to male HLM. We have confirmed expression of a number of “rare” CYP (CYP2J2, CYP4B1, CYP4V2, CYP4F3, CYP4F11, CYP8B1, CYP19A1, CYP24A1 and CYP27A1) and obtained first direct experimental data showing expression of such CYPs as CYP2F1, CYP2S1, CYP2W1, CYP4A22, CYP4X1, and CYP26A1 on a protein level. - Highlights: ► First detailed proteomic analysis of CYP isozymes expression in human liver ► Trypsin digestion patterns for almost 30 human CYP isozymes established ► The data obtained demonstrate remarkable differences in CYP expression profiles. ► Female HLM samples revealed more

  4. Mass spectrometry-based proteomic analysis of human liver cytochrome(s) P450

    International Nuclear Information System (INIS)

    Shrivas, Kamlesh; Mindaye, Samuel T.; Getie-Kebtie, Melkamu; Alterman, Michail A.

    2013-01-01

    The major objective of personalized medicine is to select optimized drug therapies and to a large degree such mission is determined by the expression profiles of cytochrome(s) P450 (CYP). Accordingly, a proteomic case study in personalized medicine is provided by the superfamily of cytochromes P450. Our knowledge about CYP isozyme expression on a protein level is very limited and based exclusively on DNA/mRNA derived data. Such information is not sufficient because transcription and translation events do not lead to correlated levels of expressed proteins. Here we report expression profiles of CYPs in human liver obtained by mass spectrometry (MS)-based proteomic approach. We analyzed 32 samples of human liver microsomes (HLM) of different sexes, ages and ethnicity along with samples of recombinant human CYPs. We have experimentally confirmed that each CYP isozyme can be effectively differentiated by their unique isozyme-specific tryptic peptide(s). Trypsin digestion patterns for almost 30 human CYP isozymes were established. Those findings should assist in selecting tryptic peptides suitable for MS-based quantitation. The data obtained demonstrate remarkable differences in CYP expression profiles. CYP2E1, CYP2C8 and CYP4A11 were the only isozymes found in all HLM samples. Female and pediatric HLM samples revealed much more diverse spectrum of expressed CYPs isozymes compared to male HLM. We have confirmed expression of a number of “rare” CYP (CYP2J2, CYP4B1, CYP4V2, CYP4F3, CYP4F11, CYP8B1, CYP19A1, CYP24A1 and CYP27A1) and obtained first direct experimental data showing expression of such CYPs as CYP2F1, CYP2S1, CYP2W1, CYP4A22, CYP4X1, and CYP26A1 on a protein level. - Highlights: ► First detailed proteomic analysis of CYP isozymes expression in human liver ► Trypsin digestion patterns for almost 30 human CYP isozymes established ► The data obtained demonstrate remarkable differences in CYP expression profiles. ► Female HLM samples revealed more

  5. Influence of polyhalogenated aromatic hydrocarbons on the induction, activity, and stabilization of cytochrome P450

    International Nuclear Information System (INIS)

    Voorman, R.

    1987-01-01

    In the course of experiments evaluating the metabolism of polybrominated biphenyls by cytochrome P450 isozymes induced by 3,4,5,3',4',5'-hexabromobiphenyl (HBB), it was discovered that the inducer remained closely associated with cytochrome P450d. Subsequent purification of cytochromes from HBB treated rates revealed a 0.5:1 association of HBB to cytochrome P450d but virtually none with cytochrome P450c or cytochrome b5. Immunochemical quantitation of cytochrome P450d in the same microsomes yielded a ratio of P450d:HBB that approached unity. Measurement of cytochrome P450d estradiol 2-hydroxylase indicated non-competitive or mixed type inhibition caused by HBB at a concentration of 10-1000 nM. Inhibition was specific to cytochrome P450d since estradiol 2-hydroxylase catalyzed by cytochrome P450h was unaffected by HBB. The ability of HCB and isosafrole to stabilize cytochrome P450d, and thus indirectly influence regulation of the enzyme, was evaluated by treating rats with a dose of TCDD sufficient to produce maximum induction of cytochromes P450c and P450d via the Ah receptor, yet insufficient to bind to the enzyme. Subsequent treatment of these animals with HCB or isosafrole and a radiolabeled amino acid, revealed a significant increase in cytochrome P450d specific content relative to cytochrome P450c and significant retention of the radiolabel in P450d relative to rats treated only with TCDD

  6. Calorimetric studies of the thermal denaturation of cytochrome c peroxidase

    International Nuclear Information System (INIS)

    Kresheck, G.C.; Erman, J.E.

    1988-01-01

    Two endotherms are observed by differential scanning calorimetry during the thermal denaturation of cytochrome c peroxidase at pH 7.0. The transition midpoint temperatures (t/sub m/) were 43.9 +- 1.4 and 63.3 +- 1.6 0 C, independent of concentration. The two endotherms were observed at all pH values between 4 and 8, with the transition temperatures varying with pH. Precipitation was observed between pH 4 and 6, and only qualitative data are presented for this region. The thermal unfolding of cytochrome c peroxidase was sensitive to the presence and ligation state of the heme. Only a single endotherm was observed for the unfolding of the apoprotein, and this transition was similar to the high-temperature transition in the holoenzyme. Addition of KCN to the holoenzyme increases the midpoint of the high-temperature transition whereas the low-temperature transition was increased upon addition of KF. Binding of the natural substrate ferricytochrome c to the enzyme increases the low-temperature transition by 4.8 +- 1.3 0 C but has no effect on the high-temperature transition at pH 7. The presence of cytochrome c peroxidase decreases the stability of cytochrome c, and both proteins appear to unfold simultaneously. The results are discussed in terms of the two domains evident in the X-ray crystallographic structure of cytochrome c peroxidase

  7. Oleamide synthesizing activity from rat kidney: identification as cytochrome c.

    Science.gov (United States)

    Driscoll, William J; Chaturvedi, Shalini; Mueller, Gregory P

    2007-08-03

    Oleamide (cis-9-octadecenamide) is the prototype member of an emerging class of lipid signaling molecules collectively known as the primary fatty acid amides. Current evidence suggests that oleamide participates in the biochemical mechanisms underlying the drive to sleep, thermoregulation, and antinociception. Despite the potential importance of oleamide in these physiologic processes, the biochemical pathway for its synthesis in vivo has not been established. We report here the discovery of an oleamide synthetase found in rat tissues using [(14)C]oleoyl-CoA and ammonium ion. Hydrogen peroxide was subsequently found to be a required cofactor. The enzyme displayed temperature and pH optima in the physiologic range, a remarkable resistance to proteolysis, and specificity for long-chain acyl-CoA substrates. The reaction demonstrated Michaelis-Menten kinetics with a K(m) for oleoyl-CoA of 21 microm. Proteomic, biochemical, and immunologic analyses were used to identify the source of the oleamide synthesizing activity as cytochrome c. This identification was based upon peptide mass fingerprinting of isolated synthase protein, a tight correlation between enzymatic activity and immunoreactivity for cytochrome c, and identical functional properties shared by the tissue-derived synthetase and commercially obtained cytochrome c. The ability of cytochrome c to catalyze the formation of oleamide experimentally raises the possibility that cytochrome c may mediate oleamide biosynthesis in vivo.

  8. Cardiolipin modulates allosterically peroxynitrite detoxification by horse heart cytochrome c

    Energy Technology Data Exchange (ETDEWEB)

    Ascenzi, Paolo, E-mail: ascenzi@uniroma3.it [Department of Biology and Interdepartmental Laboratory for Electron Microscopy, University Roma Tre, I-00146 Roma (Italy); Ciaccio, Chiara [Department of Experimental Medicine and Biochemical Sciences, University of Roma ' Tor Vergata' , I-00133 Roma (Italy); Interuniversity Consortium for the Research on the Chemistry of Metals in Biological Systems, I-70126 Bari (Italy); Sinibaldi, Federica; Santucci, Roberto [Department of Experimental Medicine and Biochemical Sciences, University of Roma ' Tor Vergata' , I-00133 Roma (Italy); Coletta, Massimo [Department of Experimental Medicine and Biochemical Sciences, University of Roma ' Tor Vergata' , I-00133 Roma (Italy); Interuniversity Consortium for the Research on the Chemistry of Metals in Biological Systems, I-70126 Bari (Italy)

    2011-01-07

    Research highlights: {yields} Cardiolipin binding to cytochrome c. {yields} Cardiolipin-dependent peroxynitrite isomerization by cytochrome c. {yields} Cardiolipin-cytochrome c complex plays pro-apoptotic effects. {yields} Cardiolipin-cytochrome c complex plays anti-apoptotic effects. -- Abstract: Upon interaction with bovine heart cardiolipin (CL), horse heart cytochrome c (cytc) changes its tertiary structure disrupting the heme-Fe-Met80 distal bond, reduces drastically the midpoint potential out of the range required for its physiological role, binds CO and NO with high affinity, and displays peroxidase activity. Here, the effect of CL on peroxynitrite isomerization by ferric cytc (cytc-Fe(III)) is reported. In the absence of CL, hexa-coordinated cytc does not catalyze peroxynitrite isomerization. In contrast, CL facilitates cytc-Fe(III)-mediated isomerization of peroxynitrite in a dose-dependent fashion inducing the penta-coordination of the heme-Fe(III)-atom. The value of the second order rate constant for CL-cytc-Fe(III)-mediated isomerization of peroxynitrite (k{sub on}) is (3.2 {+-} 0.4) x 10{sup 5} M{sup -1} s{sup -1}. The apparent dissociation equilibrium constant for CL binding to cytc-Fe(III) is (5.1 {+-} 0.8) x 10{sup -5} M. These results suggest that CL-cytc could play either pro-apoptotic or anti-apoptotic effects facilitating lipid peroxidation and scavenging of reactive nitrogen species, such as peroxynitrite, respectively.

  9. Lack of centrioles and primary cilia in STIL(-/-) mouse embryos.

    Science.gov (United States)

    David, Ahuvit; Liu, Fengying; Tibelius, Alexandra; Vulprecht, Julia; Wald, Diana; Rothermel, Ulrike; Ohana, Reut; Seitel, Alexander; Metzger, Jasmin; Ashery-Padan, Ruth; Meinzer, Hans-Peter; Gröne, Hermann-Josef; Izraeli, Shai; Krämer, Alwin

    2014-01-01

    Although most animal cells contain centrosomes, consisting of a pair of centrioles, their precise contribution to cell division and embryonic development is unclear. Genetic ablation of STIL, an essential component of the centriole replication machinery in mammalian cells, causes embryonic lethality in mice around mid gestation associated with defective Hedgehog signaling. Here, we describe, by focused ion beam scanning electron microscopy, that STIL(-/-) mouse embryos do not contain centrioles or primary cilia, suggesting that these organelles are not essential for mammalian development until mid gestation. We further show that the lack of primary cilia explains the absence of Hedgehog signaling in STIL(-/-) cells. Exogenous re-expression of STIL or STIL microcephaly mutants compatible with human survival, induced non-templated, de novo generation of centrioles in STIL(-/-) cells. Thus, while the abscence of centrioles is compatible with mammalian gastrulation, lack of centrioles and primary cilia impairs Hedgehog signaling and further embryonic development.

  10. Mitochondrial cytochrome c biogenesis: no longer an enigma.

    Science.gov (United States)

    Babbitt, Shalon E; Sutherland, Molly C; San Francisco, Brian; Mendez, Deanna L; Kranz, Robert G

    2015-08-01

    Cytochromes c (cyt c) and c1 are heme proteins that are essential for aerobic respiration. Release of cyt c from mitochondria is an important signal in apoptosis initiation. Biogenesis of c-type cytochromes involves covalent attachment of heme to two cysteines (at a conserved CXXCH sequence) in the apocytochrome. Heme attachment is catalyzed in most mitochondria by holocytochrome c synthase (HCCS), which is also necessary for the import of apocytochrome c (apocyt c). Thus, HCCS affects cellular levels of cyt c, impacting mitochondrial physiology and cell death. Here, we review the mechanisms of HCCS function and the roles of heme and residues in the CXXCH motif. Additionally, we consider concepts emerging within the two prokaryotic cytochrome c biogenesis pathways. Copyright © 2015 Elsevier Ltd. All rights reserved.

  11. Cytochrome c catalyzes the in vitro synthesis of arachidonoyl glycine

    International Nuclear Information System (INIS)

    McCue, Jeffrey M.; Driscoll, William J.; Mueller, Gregory P.

    2008-01-01

    Long chain fatty acyl glycines are an emerging class of biologically active molecules that occur naturally and produce a wide array of physiological effects. Their biosynthetic pathway, however, remains unknown. Here we report that cytochrome c catalyzes the synthesis of N-arachidonoyl glycine (NAGly) from arachidonoyl coenzyme A and glycine in the presence of hydrogen peroxide. The identity of the NAGly product was verified by isotope labeling and mass analysis. Other heme-containing proteins, hemoglobin and myoglobin, were considerably less effective in generating arachidonoyl glycine as compared to cytochrome c. The reaction catalyzed by cytochrome c in vitro points to its potential role in the formation of NAGly and other long chain fatty acyl glycines in vivo

  12. Identification of a c-Type Cytochrome Specific for Manganese Dioxide (MnO2) Reduction in Anaeromyxobacter dehalogenans Strain 2CP-C

    Science.gov (United States)

    Pfiffner, S. M.; Nissen, S.; Liu, X.; Chourey, K.; Vishnivetskaya, T. A.; Hettich, R.; Loeffler, F.

    2014-12-01

    Anaeromyxobacter dehalogenans is a metabolically versatile Deltaproteobacterium and conserves energy from the reduction of various electron acceptors, including insoluble MnO2 and ferric oxides/oxyhydroxides (FeOOH). The goal of this study was to identify c-type cytochromes involved in electron transfer to MnO2. The characterization of deletion mutants has revealed a number of c-type cytochromes involved in electron transfer to solid metal oxides in Shewanella spp. and Geobacter spp; however, a genetic system for Anaeromyxobacter is not available. The A. dehalogenans str. 2CP-C genome encodes 68 putative c-type cytochromes, which all lack functional assignments. To identify c-type cytochromes involved in electron transfer to solid MnO2, protein expression profiles of A. dehalogenans str. 2CP-C cells grown with acetate as electron donor and MnO2, ferric citrate, FeOOH, nitrate or fumarate as electron acceptors were compared. Whole cell proteomes were analyzed after trypsin proteolysis using liquid chromatography-tandem mass spectrometry (LC-MS/MS). Distinct c-type cytochrome expression patterns were observed with cells grown with different electron acceptors. A. dehalogenans str. 2CP-C grown with MnO2 expressed 25 out of the 68 c-type cytochromes encoded on the genome. The c-type cytochrome Adeh_1278 was only expressed in strain 2CP-C grown with MnO2. Reverse transcription PCR confirmed that the Adeh_1278 gene was transcribed in MnO2-grown cells but not in cells grown with other terminal electron acceptors. The expression of the Adeh_1278 gene correlated with Mn(IV) reduction activity. Adeh_1278 has three heme binding motifs and is predicted to be located in the periplasm. The identification of Adeh_1278 as a protein uniquely expressed when MnO2 serves as electron acceptor suggests its utility as a biomarker for MnO2 reduction. This example demonstrates the value of the LC-MS/MS approach for identifying specific proteins of interest and making functional assignments

  13. Cox1 mutation abrogates need for Cox23 in cytochrome c oxidase biogenesis

    Directory of Open Access Journals (Sweden)

    Richard Dela Cruz

    2016-06-01

    Full Text Available Cox23 is a known conserved assembly factor for cytochrome c oxidase, although its role in cytochrome c oxidase (CcO biogenesis remains unresolved. To gain additional insights into its role, we isolated spontaneous suppressors of the respiratory growth defect in cox23∆ yeast cells. We recovered independent colonies that propagated on glycerol/lactate medium for cox23∆ cells at 37°C. We mapped these mutations to the mitochondrial genome and specifically to COX1 yielding an I101F substitution. The I101F Cox1 allele is a gain-of-function mutation enabling yeast to respire in the absence of Cox23. CcO subunit steady-state levels were restored with the I101F Cox1 suppressor mutation and oxygen consumption and CcO activity were likewise restored. Cells harboring the mitochondrial genome encoding I101F Cox1 were used to delete genes for other CcO assembly factors to test the specificity of the Cox1 mutation as a suppressor of cox23∆ cells. The Cox1 mutant allele fails to support respiratory growth in yeast lacking Cox17, Cox19, Coa1, Coa2, Cox14 or Shy1, demonstrating its specific suppressor activity for cox23∆ cells.

  14. Fast prediction of cytochrome P450 mediated drug metabolism

    DEFF Research Database (Denmark)

    Rydberg, Patrik Åke Anders; Poongavanam, Vasanthanathan; Oostenbrink, Chris

    2009-01-01

    Cytochrome P450 mediated metabolism of drugs is one of the major determinants of their kinetic profile, and prediction of this metabolism is therefore highly relevant during the drug discovery and development process. A new rule-based method, based on results from density functional theory...... calculations, for predicting activation energies for aliphatic and aromatic oxidations by cytochromes P450 is developed and compared with several other methods. Although the applicability of the method is currently limited to a subset of P450 reactions, these reactions describe more than 90...

  15. Evaluation of cytochrome P-450 concentration in Saccharomyces cerevisiae strains

    Directory of Open Access Journals (Sweden)

    Míriam Cristina Sakuragui Matuo

    2010-09-01

    Full Text Available Saccharomyces cerevisiae has been widely used in mutagenicity tests due to the presence of a cytochrome P-450 system, capable of metabolizing promutagens to active mutagens. There are a large number of S. cerevisiae strains with varying abilities to produce cytochrome P-450. However, strain selection and ideal cultivation conditions are not well defined. We compared cytochrome P-450 levels in four different S. cerevisiae strains and evaluated the cultivation conditions necessary to obtain the highest levels. The amount of cytochrome P-450 produced by each strain varied, as did the incubation time needed to reach the maximum level. The highest cytochrome P-450 concentrations were found in media containing fermentable sugars. The NCYC 240 strain produced the highest level of cytochrome P-450 when grown in the presence of 20 % (w/v glucose. The addition of ethanol to the media also increased cytochrome P-450 synthesis in this strain. These results indicate cultivation conditions must be specific and well-established for the strain selected in order to assure high cytochrome P-450 levels and reliable mutagenicity results.Linhagens de Saccharomyces cerevisiae tem sido amplamente empregadas em testes de mutagenicidade devido à presença de um sistema citocromo P-450 capaz de metabolizar substâncias pró-mutagênicas à sua forma ativa. Devido à grande variedade de linhagens de S. cerevisiae com diferentes capacidades de produção de citocromo P-450, torna-se necessária a seleção de cepas, bem como a definição das condições ideais de cultivo. Neste trabalho, foram comparados os níveis de citocromo P-450 em quatro diferentes linhagens de S. cerevisiae e avaliadas as condições de cultivo necessárias para obtenção de altas concentrações deste sistema enzimático. O maior nível enzimático foi encontrado na linhagem NCYC 240 em presença de 20 % de glicose (p/v. A adição de etanol ao meio de cultura também produziu um aumento na s

  16. Synthesis of cytochrome c oxidase 1 (SCO1) inhibits insulin sensitivity by decreasing copper levels in adipocytes.

    Science.gov (United States)

    Wei, Xiang-Bo; Guo, Liang; Liu, Yang; Zhou, Shui-Rong; Liu, Yuan; Dou, Xin; Du, Shao-Yue; Ding, Meng; Peng, Wan-Qiu; Qian, Shu-Wen; Huang, Hai-Yan; Tang, Qi-Qun

    2017-09-23

    Dysregulation of insulin signaling leads to type 2 diabetes mellitus (T2DM) and other metabolic disorders. Obesity is an important contributor to insulin resistance, and although the understanding of this relationship has improved in recent years, the mechanism of obesity-induced insulin resistance is not completely understood. Disorders of copper metabolism tend to accompany the development of obesity, which increases the risk of insulin resistance. Synthesis of cytochrome c oxidase 1 (SCO1) functions in the assembly of cytochrome c oxidase (COX) and cellular copper homeostasis. However, the role of SCO1 in the regulation of metabolism remains unknown. Here, we found that obese mice had higher expression of SCO1 and lower levels of copper in white adipose tissue (WAT) than did the control mice. Overexpression of SCO1 in adipocytes was associated with copper deficiency. Copper increased insulin sensitivity by decreasing the level of phosphatase and tensin homolog (PTEN) protein. Ectopic expression of SCO1 led to insulin resistance and was accompanied by a decrease in intracellular copper level, and addition of copper abolished the inhibitory effect of SCO1 on insulin sensitivity. Our results demonstrated a novel role of SCO1 in modulating insulin sensitivity via the regulation of copper concentration in WAT and suggested a potential therapeutic target for T2DM. Copyright © 2017. Published by Elsevier Inc.

  17. Chronic Ethanol Consumption in Mice Alters Hepatocyte Lipid Droplet Properties

    Science.gov (United States)

    Orlicky, David J.; Roede, James R.; Bales, Elise; Greenwood, Carrie; Greenberg, Andrew; Petersen, Dennis; McManaman, James L.

    2014-01-01

    Background Hepatosteatosis is a common pathological feature of impaired hepatic metabolism following chronic alcohol consumption. Although often benign and reversible, it is widely believed that steatosis is a risk factor for development of advanced liver pathologies, including steatohepatitis and fibrosis. The hepatocyte alterations accompanying the initiation of steatosis are not yet clearly defined. Methods Induction of hepatosteatosis by chronic ethanol consumption was investigated using the Lieber-DeCarli (LD) high fat diet model. Effects were assessed by immunohistochemistry and blood and tissue enzymatic assays. Cell culture models were employed for mechanistic studies. Results Pair feeding mice ethanol (LD-Et) or isocaloric control (LD-Co) diets for 6 weeks progressively increased hepatocyte triglyceride accumulation in morphological, biochemical, and zonally distinct cytoplasmic lipid droplets (CLD). The LD-Et diet induced zone 2-specific triglyceride accumulation in large CLD coated with perilipin, adipophilin (ADPH), and TIP47. In LD-Co- fed mice, CLD were significantly smaller than those in LD-Et-fed mice and lacked perilipin. A direct role of perilipin in formation of large CLD was further suggested by cell culture studies showing that perilipin-coated CLD were significantly larger than those coated with ADPH or TIP47. LD-Co- and LD-Et-fed animals also differed in hepatic metabolic stress responses. In LD-Et but not LD-Co-fed mice, inductions were observed in the following: microsomal ethanol-oxidizing system [cytochrome P-4502E1 (CYP2E1)], hypoxia response pathway (hypoxia-inducible factor 1 alpha, HIF1α), endoplasmic reticulum stress pathway (calreticulin), and synthesis of lipid peroxidation products [4-hydroxynonenal (4-HNE)]. CYP2E1 and HIF1 α immunostaining localized to zone 3 and did not correlate with accumulation of large CLD. In contrast, calreticulin and 4-HNE immunostaining closely correlated with large CLD accumulation. Importantly, 4

  18. Loss of NCB5OR in the cerebellum disturbs iron pathways, potentiates behavioral abnormalities, and exacerbates harmaline-induced tremor in mice.

    Science.gov (United States)

    Stroh, Matthew A; Winter, Michelle K; Swerdlow, Russell H; McCarson, Kenneth E; Zhu, Hao

    2016-08-01

    Iron dyshomeostasis has been implicated in many diseases, including a number of neurological conditions. Cytosolic NADH cytochrome b5 oxidoreductase (NCB5OR) is ubiquitously expressed in animal tissues and is capable of reducing ferric iron in vitro. We previously reported that global gene ablation of NCB5OR resulted in early-onset diabetes and altered iron homeostasis in mice. To further investigate the specific effects of NCB5OR deficiency on neural tissue without contributions from known phenotypes, we generated a conditional knockout (CKO) mouse that lacks NCB5OR only in the cerebellum and midbrain. Assessment of molecular markers in the cerebellum of CKO mice revealed changes in pathways associated with cellular and mitochondrial iron homeostasis. (59)Fe pulse-feeding experiments revealed cerebellum-specific increased or decreased uptake of iron by 7 and 16 weeks of age, respectively. Additionally, we characterized behavioral changes associated with loss of NCB5OR in the cerebellum and midbrain in the context of dietary iron deprivation-evoked generalized iron deficiency. Locomotor activity was reduced and complex motor task execution was altered in CKO mice treated with an iron deficient diet. A sucrose preference test revealed that the reward response was intact in CKO mice, but that iron deficient diet consumption altered sucrose preference in all mice. Detailed gait analysis revealed locomotor changes in CKO mice associated with dysfunctional proprioception and locomotor activation independent of dietary iron deficiency. Finally, we demonstrate that loss of NCB5OR in the cerebellum and midbrain exacerbated harmaline-induced tremor activity. Our findings suggest an essential role for NCB5OR in maintaining both iron homeostasis and the proper functioning of various locomotor pathways in the mouse cerebellum and midbrain.

  19. Effect of carbon source on the accumulation of cytochrome P-450 in the yeast Saccharomyces cerevisiae.

    OpenAIRE

    Kärenlampi, S O; Marin, E; Hänninen, O O

    1981-01-01

    The appearance of cytochrome P-450 in the yeast Saccharomyces cerevisiae depended on the substrate supporting growth. Cytochrome P-450 was apparent in yeast cells grown on a strongly fermentable sugar such as D-glucose, D-fructose or sucrose. When yeast was grown on D-galactose, D-mannose or maltose, where fermentation and respiration occurred concomitantly, cytochrome P-450 was also formed. The cytochrome P-450 concentration was maximal at the beginning of the stationary phase of the culture...

  20. Functional characterization of cytochrome P450-derived epoxyeicosatrienoic acids in adipogenesis and obesity.

    Science.gov (United States)

    Zha, Weibin; Edin, Matthew L; Vendrov, Kimberly C; Schuck, Robert N; Lih, Fred B; Jat, Jawahar Lal; Bradbury, J Alyce; DeGraff, Laura M; Hua, Kunjie; Tomer, Kenneth B; Falck, John R; Zeldin, Darryl C; Lee, Craig R

    2014-10-01

    Adipogenesis plays a critical role in the initiation and progression of obesity. Although cytochrome P450 (CYP)-derived epoxyeicosatrienoic acids (EETs) have emerged as a potential therapeutic target for cardiometabolic disease, the functional contribution of EETs to adipogenesis and the pathogenesis of obesity remain poorly understood. Our studies demonstrated that induction of adipogenesis in differentiated 3T3-L1 cells (in vitro) and obesity-associated adipose expansion in high-fat diet (HFD)-fed mice (in vivo) significantly dysregulate the CYP epoxygenase pathway and evoke a marked suppression of adipose-derived EET levels. Subsequent in vitro experiments demonstrated that exogenous EET analog administration elicits potent anti-adipogenic effects via inhibition of the early phase of adipogenesis. Furthermore, EET analog administration to mice significantly mitigated HFD-induced weight gain, adipose tissue expansion, pro-adipogenic gene expression, and glucose intolerance. Collectively, these findings suggest that suppression of EET bioavailability in adipose tissue is a key pathological consequence of obesity, and strategies that promote the protective effects of EETs in adipose tissue offer enormous therapeutic potential for obesity and its downstream pathological consequences. Copyright © 2014 by the American Society for Biochemistry and Molecular Biology, Inc.

  1. Computational identification of putative cytochrome P450 genes in ...

    African Journals Online (AJOL)

    Chattha

    Economically, legumes represent the second most important family of crop plants after Poacea (grass family), accounting for ... further characterization of P450 genes with both known and unknown functions. MATERIALS AND METHODS ..... Cytochrome P450. In: Somerville CR, Meyerowitz EM (eds) .The Arabidopsis book,.

  2. Interplay between cytochrome c and gibberellins during Arabidopsis vegetative development

    Czech Academy of Sciences Publication Activity Database

    Racca, S.; Welchen, E.; Gras, D. E.; Tarkowská, Danuše; Turečková, Veronika; Maurino, V. G.; Gonzalez, D. H.

    2018-01-01

    Roč. 94, č. 1 (2018), s. 105-121 ISSN 0960-7412 R&D Projects: GA MŠk(CZ) LO1204 Institutional support: RVO:61389030 Keywords : Arabidopsis thaliana * cytochrome c * DELLA protein * gibberellin * mitochondrion Subject RIV: EB - Genetics ; Molecular Biology OBOR OECD: Plant sciences, botany Impact factor: 5.901, year: 2016

  3. The Role of Cytochromes P450 in Infection

    Directory of Open Access Journals (Sweden)

    Elisavet Stavropoulou

    2018-01-01

    Full Text Available Cytochromes are expressed in many different tissues of the human body. They are found mostly in intestinal and hepatic tissues. Cytochromes P450 (CYPs are enzymes that oxidize substances using iron and are able to metabolize a large variety of xenobiotic substances. CYP enzymes are linked to a wide array of reactions including and O-dealkylation, S-oxidation, epoxidation, and hydroxylation. The activity of the typical P450 cytochrome is influenced by a variety of factors, such as genus, environment, disease state, herbicide, alcohol, and herbal medications. However, diet seems to play a major role. The mechanisms of action of dietary chemicals, macro- and micronutrients on specific CYP isoenzymes have been extensively studied. Dietary modulation has effects upon the metabolism of xenobiotics. Cytochromes harbor intra- or interindividual and intra- or interethnic genetic polymorphisms. Bacteria were shown to express CYP-like genes. The tremendous metabolic activity of the microbiota is associated to its abundant pool of CYP enzymes, which catalyze phase I and II reactions in drug metabolism. Disease states, intestinal disturbances, aging, environmental toxic effects, chemical exposures or nutrition modulate the microbial metabolism of a drug before absorption. A plethora of effects exhibited by most of CYP enzymes can resemble those of proinflammatory cytokines and IFNs. Moreover, they are involved in the initiation and persistence of pathologic pain by directly activating sensory neurons and inflammatory cytokines.

  4. Redox Thermodynamics of Cytochromes c Subjected to Urea Induced Unfolding

    NARCIS (Netherlands)

    Monari, S.; Ranieri, A.; Di Rocco, G.; van der Zwan, G.; Peressini, S.; Tavagnacco, C.; Millo, D.; Borsari, M.

    2009-01-01

    The thermodynamics of the electron transfer (ET) process for beef heart and yeast cytochromes c and the Lys72Ala/Lys73Ala/Lys79Ala mutant of the latter species subjected to progressive urea-induced unfolding was determined electrochemically. The results indicate the presence of at least three

  5. Multivariate Modeling of Cytochrome P450 Enzymes for 4 ...

    African Journals Online (AJOL)

    Conclusion: Apart from insights into important molecular properties for CYP inhibition, the findings may also guide further investigations of novel drug candidates that are unlikely to inhibit multiple CYP sub-types. Keywords: Antimalarial, Chloroquine, Cytochrome P450, Genetic algorithm-based multiple linear regression, ...

  6. [Immunosuppressant effect of cyclophosphamide activated in vitro by liver microsomes from different strains of mice].

    Science.gov (United States)

    Telegin, L Iu; Zhirnov, G F; Mazurov, A V; Pevnitskiĭ, L A

    1981-07-01

    The paper is concerned with activation of cyclophosphamide by mouse liver microsomes in vitro. Liver microsomes from BALB/c mice metabolize cyclophosphamide more effectively as compared with those from DBA/2 mice, which manifested by a more intense output of products having alkylating or immunodepressant properties. This seems likely to be a consequence of the increased P-450 cytochrome content in liver microsomes from BALB/c mice, as well as of its structural characteristics in the mouse. The relationship between the immunodepressant effect of cyclophosphamide in vivo and in vitro in mice of varied genotypes is discussed.

  7. Normal macrophage function in copper deficient mice

    International Nuclear Information System (INIS)

    Lukasewycz, O.A.; Kolquist, K.L.; Prohaska, J.R.

    1986-01-01

    Copper deficiency (-Cu) was produced in C57 BL and C58 mice by feeding a low copper diet (modified AIN-76A) from birth. Mice given supplemental copper in the drinking water (+Cu) served as controls. Copper status was monitored by assay of ceruloplasmin (CP) activity. Macrophages (M0) were obtained from matched +Cu and -Cu male 7 week-old mice by peritoneal lavage 3 days after thioglycollate stimulation. M0 were assayed in terms of lipopolysaccharide-induced hexose monophosphate shunt activity by monitoring 14 CO 2 production from [1- 14 C]-glucose and by the determination of phagocytic index using fluorescein labelled latex bead ingestion. M0 from -Cu mice were equivalent to those of +Cu mice in both these parameters. However, superoxide dismutase and cytochrome oxidase activities were both significantly lower in -Cu M0, confirming a functional copper deficiency. Previous results from this laboratory have shown that -Cu mice have a decreased antibody response to sheep erythrocyte antigens and a diminished reactivity to B and T cell mitogens. These immunological insufficiencies appear to be proportional to the severity of copper depletion as determined by CP levels. Furthermore, -Cu lymphocytes exhibit depressed mixed lymphocyte reactivity consistent with alterations at the membrane surface. The present results suggest that M0/monocytes are less severely affected than lymphocytes in copper deficiency states

  8. Therapeutic cloning in individual parkinsonian mice

    Science.gov (United States)

    Tabar, Viviane; Tomishima, Mark; Panagiotakos, Georgia; Wakayama, Sayaka; Menon, Jayanthi; Chan, Bill; Mizutani, Eiji; Al-Shamy, George; Ohta, Hiroshi; Wakayama, Teruhiko; Studer, Lorenz

    2009-01-01

    Cell transplantation with embryonic stem (ES) cell progeny requires immunological compatibility with host tissue. ‘Therapeutic cloning’ is a strategy to overcome this limitation by generating nuclear transfer (nt)ES cells that are genetically matched to an individual. Here we establish the feasibility of treating individual mice via therapeutic cloning. Derivation of 187 ntES cell lines from 24 parkinsonian mice, dopaminergic differentiation, and transplantation into individually matched host mice showed therapeutic efficacy and lack of immunological response. PMID:18376409

  9. Mechanistic Scrutiny Identifies a Kinetic Role for Cytochrome b5 Regulation of Human Cytochrome P450c17 (CYP17A1, P450 17A1.

    Directory of Open Access Journals (Sweden)

    Alexandr N Simonov

    Full Text Available Cytochrome P450c17 (P450 17A1, CYP17A1 is a critical enzyme in the synthesis of androgens and is now a target enzyme for the treatment of prostate cancer. Cytochrome P450c17 can exhibit either one or two physiological enzymatic activities differentially regulated by cytochrome b5. How this is achieved remains unknown. Here, comprehensive in silico, in vivo and in vitro analyses were undertaken. Fluorescence Resonance Energy Transfer analysis showed close interactions within living cells between cytochrome P450c17 and cytochrome b5. In silico modeling identified the sites of interaction and confirmed that E48 and E49 residues in cytochrome b5 are essential for activity. Quartz crystal microbalance studies identified specific protein-protein interactions in a lipid membrane. Voltammetric analysis revealed that the wild type cytochrome b5, but not a mutated, E48G/E49G cyt b5, altered the kinetics of electron transfer between the electrode and the P450c17. We conclude that cytochrome b5 can influence the electronic conductivity of cytochrome P450c17 via allosteric, protein-protein interactions.

  10. Lansoprazole is an antituberculous prodrug targeting cytochrome bc1.

    Science.gov (United States)

    Rybniker, Jan; Vocat, Anthony; Sala, Claudia; Busso, Philippe; Pojer, Florence; Benjak, Andrej; Cole, Stewart T

    2015-07-09

    Better antibiotics capable of killing multi-drug-resistant Mycobacterium tuberculosis are urgently needed. Despite extensive drug discovery efforts, only a few promising candidates are on the horizon and alternative screening protocols are required. Here, by testing a panel of FDA-approved drugs in a host cell-based assay, we show that the blockbuster drug lansoprazole (Prevacid), a gastric proton-pump inhibitor, has intracellular activity against M. tuberculosis. Ex vivo pharmacokinetics and target identification studies reveal that lansoprazole kills M. tuberculosis by targeting its cytochrome bc1 complex through intracellular sulfoxide reduction to lansoprazole sulfide. This novel class of cytochrome bc1 inhibitors is highly active against drug-resistant clinical isolates and spares the human H(+)K(+)-ATPase thus providing excellent opportunities for targeting the major pathogen M. tuberculosis. Our finding provides proof of concept for hit expansion by metabolic activation, a powerful tool for antibiotic screens.

  11. Variations in epidermal cytochrome oxidase activity after local irradiation

    International Nuclear Information System (INIS)

    Itoiz, M.E.; Rey, B.M. de; Cabrini, R.L.

    1982-01-01

    Cytochrome oxidase activity was evaluated histochemically as an index of mitochondrial damage after local irradiation with X-rays. It was determined by microphotometry on the tail skin of newly born Wistar rats four days after irradiation with doses ranging from 2 to 16krad. The enzyme activity of the whole epidermis increased after irradiation, the increases being related to the increase in thickness of the epithelium which was observed as a response to irradiation injury. Within the dose range tested, the enzyme concentration (expressed per unit volume of tissue) decreased in relation to the dose applied. At the electron microscopy level, the cytochemical demonstration of cytochrome oxidase revealed an irregular reaction over the cristae, intramitochondrial vacuolization and partial homogenization of the matrix. Positive membrane fragments were seen around lipid droplets. This reaction confirms the mitochondrial origin of these previously observed radiation-induced vacuoles. (author)

  12. Interaction of rocuronium with human liver cytochromes P450

    OpenAIRE

    Anzenbacherova, Eva; Spicakova, Alena; Jourova, Lenka; Ulrichova, Jitka; Adamus, Milan; Bachleda, Petr; Anzenbacher, Pavel

    2015-01-01

    Rocuronium is a neuromuscular blocking agent acting as a competitive antagonist of acetylcholine. Results of an inhibition of eight individual liver microsomal cytochromes P450 (CYP) are presented. As the patients are routinely premedicated with diazepam, possible interaction of diazepam with rocuronium has been also studied. Results indicated that rocuronium interacts with human liver microsomal CYPs by binding to the substrate site. Next, concentration dependent inhibition of liver micro...

  13. Coordinate regulation of cytochrome and alternative pathway respiration in tobacco.

    Science.gov (United States)

    Vanlerberghe, G C; McIntosh, L

    1992-12-01

    In suspension cells of NT1 tobacco (Nicotiana tabacum L. cv bright yellow), inhibition of the cytochrome pathway of respiration with antimycin A induced a large increase in the capacity of the alternative pathway over a period of approximately 12 h, as confirmed in both whole cells and isolated mitochondria. The increase in alternative pathway capacity required de novo RNA and protein synthesis and correlated closely with the increase of a 35-kD alternative oxidase protein. When the cytochrome pathway of intact cells was inhibited by antimycin A, respiration proceeded exclusively through the alternative pathway, reached rates significantly higher than before antimycin A addition, and was not stimulated by p-trifluoromethoxycarbonylcyanide (FCCP). When inhibition of the cytochrome pathway was relieved, alternative pathway capacity and the level of the 35-kD alternative oxidase protein declined. Respiration rate also declined and could once again be stimulated by FCCP. These observations show that the capacities of the mitochondrial electron transport pathways can be regulated in a coordinate fashion.

  14. Monoclonal antibodies to drosophila cytochrome P-450's

    International Nuclear Information System (INIS)

    Sundseth, S.S.; Kennel, S.J.; Waters, L.C.

    1987-01-01

    Hybridomas producing monoclonal antibodies were prepared by the fusion of SP2/0 myeloma cells and spleen cells from a female BALB/c mouse immunized by cytochrome P-450-A and P-450-B purified from Drosophila Hikone-R (BG) microsomes. P-450-A and P-450-B are electrophoretically distinct subsets of Drosophila P-450. P-450-A is ubiquitous among strains tested, while P-450-B is present in only a few strains displaying unique enzyme activities and increased insecticide resistance. The Oregon-R strain contains only cytochromes P-450-A and is susceptible to insecticides. The authors Hikone-R (BG) strain expresses both cytochromes P-450-A and P-450-B and is insecticide resistant. Antibody producing hybridomas were detected in a solid-phase radioimmunoassay (RIA) by binding to Hikone-R (BG) or Oregon-R microsomes. Four independent hybridomas were identified as producing monoclonal antibodies that recognized proteins in the P-450 complex by immunoblot experiments. Three monoclonal antibodies recognized P-450-A proteins, while one monoclonal antibody bound predominantly P-450-B. This monoclonal antibody also recognized southern armyworm (Spodoptera eridania, Cramer) microsomal proteins

  15. Covalent modification of cytochrome c by reactive metabolites of furan.

    Science.gov (United States)

    Phillips, Martin B; Sullivan, Mathilde M; Villalta, Peter W; Peterson, Lisa A

    2014-01-21

    Metabolism of the hepatotoxicant furan leads to protein adduct formation in the target organ. The initial bioactivation step involves cytochrome P450-catalyzed oxidation of furan, generating cis-2-butene-1,4-dial (BDA). BDA reacts with lysine to form pyrrolin-2-one adducts. Metabolic studies indicate that BDA also reacts with glutathione (GSH) to generate 2-(S-glutathionyl)butanedial (GSH-BDA), which then reacts with lysine to form GSH-BDA-lysine cross-links. To explore the relative reactivity of these two reactive intermediates, cytochrome c was reacted with BDA in the presence and absence of GSH. As judged by MALDI-TOF mass spectrometry, BDA reacts extensively with cytochrome c to form adducts that add 66 Da to the protein, consistent with the formation of pyrrolinone adducts. Addition of GSH to the reaction mixture reduced the overall extent of adduct formation. The mass of the adducted protein was shifted by 355 Da as expected for GSH-BDA-protein cross-link formation. LC-MS/MS analysis of the tryptic digests of the alkylated protein indicated that the majority of adducts occurred on lysine residues, with BDA reacting less selectively than GSH-BDA. Both types of adducts may contribute to the toxic effects of furan.

  16. Tributyltin interacts with mitochondria and induces cytochrome c release.

    Science.gov (United States)

    Nishikimi, A; Kira, Y; Kasahara, E; Sato, E F; Kanno, T; Utsumi, K; Inoue, M

    2001-01-01

    Although triorganotins are potent inducers of apoptosis in various cell types, the critical targets of these compounds and the mechanisms by which they lead to cell death remain to be elucidated. There are two major pathways by which apoptotic cell death occurs: one is triggered by a cytokine mediator and the other is by a mitochondrion-dependent mechanism. To elucidate the mechanism of triorganotin-induced apoptosis, we studied the effect of tributyltin on mitochondrial function. We found that moderately low doses of tributyltin decrease mitochondrial membrane potential and induce cytochrome c release by a mechanism inhibited by cyclosporine A and bongkrekic acid. Tributyltin-induced cytochrome c release is also prevented by dithiols such as dithiothreitol and 2,3-dimercaptopropanol but not by monothiols such as GSH, N-acetyl-L-cysteine, L-cysteine and 2-mercaptoethanol. Further studies with phenylarsine oxide agarose revealed that tributyltin interacts with the adenine nucleotide translocator, a functional constituent of the mitochondrial permeability transition pore, which is selectively inhibited by dithiothreitol. These results suggest that, at low doses, tributyltin interacts selectively with critical thiol residues in the adenine nucleotide translocator and opens the permeability transition pore, thereby decreasing membrane potential and releasing cytochrome c from mitochondria, a series of events consistent with established mechanistic models of apoptosis. PMID:11368793

  17. Rational redesign of the biodegradative enzyme cytochrome P450 cam:

    International Nuclear Information System (INIS)

    Ornstein, R.; Paulsen, M.; Bass, M.; Arnold, G.

    1991-03-01

    Cytochromes P450, a superfamily of monooxygenase enzymes present in all kingdoms of living organisms, are very versatile with respect to substrate range and catalytic functionality. Many recalcitrant halogenated hydrocarbons, on DOE sites and throughout the nation, result in serious environmental impact. Cytochromes P450 have been shown to be catalytically capable of, at least partial, dehalogenation of some such compounds. Clearly, however, their active site stereochemistry and related functional components are not well suited for this role because the rates of dehalogenation are generally rather modest. The evolution of modified active site and access channel structures may proceed very slowly if multiple genetic changes are simultaneously required for enzyme adaptation. Since each mutational event is by itself a rare event, a basic premise of our research is that designing multiple changes into an enzyme may be more timely than waiting for them to occur biologically either via natural selection or under laboratory-controlled conditions. Starting with available high-resolution x-ray crystal structures, molecular modeling and molecular dynamics simulations have been used to probe the basic structure/function principles and conformational fluctuations of the biodegradative enzyme, cytochrome P450cam (camphor hydroxylase from Pseudomonas putida) and active site mutants, to provide the fundamental understanding necessary for rational engineering of the enzyme for modified substrate specificity. In the present paper, we review our progress to data, in the area of molecular dynamics simulations and active site redesign of P450cam. 36 refs., 2 figs

  18. Identification of human cytochrome P450s as autoantigens.

    Science.gov (United States)

    Manns, M P; Johnson, E F

    1991-01-01

    Antimicrosomal antibodies in inflammatory liver diseases all seem to be directed against members of the cytochrome P450 family of proteins. These autoantigens seem to be genetically polymorphic, the autoantibodies are inhibitory, and the autoepitopes are generally conserved among species. Anti-P450 autoantibodies share these characteristics with other autoantibodies, for example, antinuclear antibodies in systemic lupus erythematosus. The identification of P450s as human autoantigens is clinically important. Diagnostic tests will be developed on the basis of cloned antigen, facilitating a better diagnosis of drug-induced and idiopathic autoimmune hepatitis. It is unknown what triggers autoantibody production against cytochrome P450 proteins. Furthermore, their pathogenetic role and thus their involvement in tissue destruction is unclear. In this context LKM1 autoantibodies may serve as a model. Although LKM1 antibodies are inhibitory, all LKM1 antibody-positive patients tested so far are extensive metabolizers for drug metabolism mediated by P450IID6 and express this protein in their livers. Thus, the inhibitory LKM1 autoantibody does not sufficiently penetrate through the intact liver cell membrane to inhibit enzyme function in vivo. Presumably, tissue destruction in autoimmune hepatitis is mediated by liver-infiltrating T lymphocytes. T lymphocytes have been cloned from liver tissue that specifically proliferate in the presence of recombinant cytochrome P450IID6. The construction of overlapping cDNA subclones is also valuable to identify immunodominant B cell as well as relevant T cell epitopes.

  19. Formation of putative chloroplast cytochromes in isolated developing pea chloroplasts

    International Nuclear Information System (INIS)

    Thaver, S.S.; Bhava, D.; Castelfranco, P.A.

    1986-01-01

    In addition to chlorophyll-protein complexes, other proteins were labeled when isolated developing pea chloroplasts were incubated with [ 14 C]-5-aminolevulinic acid [ 14 C]-ALA. The major labeled band (M/sub r/ = 43 kDa by LDS-PAGE) was labeled even in the presence of chloramphenicol. Heme-dependent peroxidase activity (as detected by the tetramethyl benzidine-H 2 O 2 stain) was not visibly associated with this band. The radioactive band was stable to heat, 5% HCl in acetone, and was absent if the incubation with [ 14 C]-5-aminolevulinic acid was carried out in the presence of N-methyl protoporphyrin IX dimethyl ester (a specific inhibitor of ferrochelatase). Organic solvent extraction procedures for the enrichment of cytochrome f from chloroplast membranes also extracted this unknown labeled product. It was concluded that this labeled product was probably a c-type cytochrome. The effect of exogenous iron, iron chelators, gabaculine (an inhibitor of ALA synthesis) and other incubation conditions upon the in vitro formation of putative chloroplast cytochromes will be discussed

  20. Conformational changes of the NADPH-dependent cytochrome P450 reductase in the course of electron transfer to cytochromes P450

    DEFF Research Database (Denmark)

    Laursen, Tomas; Jensen, Kenneth; Møller, Birger Lindberg

    2011-01-01

    The NADPH-dependent cytochrome P450 reductase (CPR) is a key electron donor to eucaryotic cytochromes P450 (CYPs). CPR shuttles electrons from NADPH through the FAD and FMN-coenzymes into the iron of the prosthetic heme-group of the CYP. In the course of these electron transfer reactions, CPR und...... to serve as an effective electron transferring "nano-machine"....

  1. One-electron reduction of mitomycin c by rat liver : role of cytochrome P-450 and NADPH-cytochrome P-450 reductase

    NARCIS (Netherlands)

    Vromans, R M; Van de Straat, R; Groeneveld, M.; Vermeulen, N P

    1. The role of cytochrome P-450 in the one-electron reduction of mitomycin c was studied in rat hepatic microsomal systems and in reconstituted systems of purified cytochrome P-450. Formation of H2O2 from redox cycling of the reduced mitomycin c in the presence of O2 and the alkylation of

  2. In-silico assessment of protein-protein electron transfer. a case study: cytochrome c peroxidase--cytochrome c.

    Directory of Open Access Journals (Sweden)

    Frank H Wallrapp

    Full Text Available The fast development of software and hardware is notably helping in closing the gap between macroscopic and microscopic data. Using a novel theoretical strategy combining molecular dynamics simulations, conformational clustering, ab-initio quantum mechanics and electronic coupling calculations, we show how computational methodologies are mature enough to provide accurate atomistic details into the mechanism of electron transfer (ET processes in complex protein systems, known to be a significant challenge. We performed a quantitative study of the ET between Cytochrome c Peroxidase and its redox partner Cytochrome c. Our results confirm the ET mechanism as hole transfer (HT through residues Ala194, Ala193, Gly192 and Trp191 of CcP. Furthermore, our findings indicate the fine evolution of the enzyme to approach an elevated turnover rate of 5.47 × 10(6 s(-1 for the ET between Cytc and CcP through establishment of a localized bridge state in Trp191.

  3. Rates and energetics of tyrosine ring flips in yeast iso-2-cytochrome c

    International Nuclear Information System (INIS)

    Nall, B.T.; Zuniga, E.H.

    1990-01-01

    Isotope-edited nuclear magnetic resonance spectroscopy is used to monitor ring flip motion of the five tyrosine side chains in the oxidized and reduced forms of yeast iso-2-cytochrome c. With specifically labeled protein purified from yeast grown on media containing [3,5- 13 C]tyrosine, isotope-edited one-dimensional proton spectra have been collected over a 5-55 degree C temperature range. The spectra allow selective observation of the 10 3,5 tyrosine ring proton resonances and, using a two-site exchange model, allow estimation of the temperature dependence of ring flip rates from motion-induced changes in proton line shapes. For the reduced protein, tyrosines II and IV are in fast exchange throughout the temperature range investigated, or lack resolvable differences in static chemical shifts for the 3,5 ring protons. Tyrosines I, III, and V are in sloe exchange at low temperatures and in fast exchange at high temperatures. Spectral simulations give flip rates for individual tyrosines in a range of one flip per second at low temperatures to thousands of flips per second at high temperatures. Eyring plots show that two of the tyrosines (I and III) have essentially the same activation parameters. Tentative sequence-specific assignments for the tyrosines in reduced iso-2 are suggested by comparison to horse cytochrome c. For oxidized iso-2, five resonances are observed at high temperatures, suggesting flip rates for all five tyrosines sufficient to average static chemical shift differences. At lower temperatures, there is evidence of intermediate and slow flipping for some of the rings

  4. Structure and expression of cytochrome f in an Oenothera plastome mutant.

    Science.gov (United States)

    Johnson, E M; Sears, B B

    1990-06-01

    The chloroplast mutant pm7 is one of a number of mutants derived from the plastome mutator (pm) line of Oenothera hookeri, strain Johansen. Immunoblotting showed that this mutant accumulates a protein that is cross-antigenic with cytochrome f, but five kilodaltons larger than the mature wild-type protein. Since cytochrome f is known to be translated on plastid ribosomes as a precursor with an amino-terminal extension, it is proposed that the unprocessed cytochrome f precursor accumulates in pm7. In addition to this precursor-sized cytochrome f protein, some mature-sized cytochrome f was also found in the mutant plastids. The pm7 mutation is inherited in a non-Mendelian fashion; but no alterations in chloroplast DNA restriction patterns, or differences in DNA sequence in the region encoding cytochrome f, were found in a comparison of the wild-type and pm7 chloroplast DNAs. Although the mutant was capable of synthesizing heme, no covalently-bound heme, normally found associated with mature, functional, cytochrome f was detected in the mutant at sizes expected for the presumed precursor, or for mature cytochrome f. These results indicate that the aberrant accumulation of a precursor-sized cytochrome f in pm7 is not due to a lesion directly in the plastid gene encoding cytochrome f, petA, or to a deficiency in the ability of the mutant plastids to synthesize or accumulate heme.

  5. Menoctone Resistance in Malaria Parasites Is Conferred by M133I Mutations in Cytochrome b That Are Transmissible through Mosquitoes.

    Science.gov (United States)

    Blake, Lynn D; Johnson, Myles E; Siegel, Sasha V; McQueen, Adonis; Iyamu, Iredia D; Shaikh, Abdul Kadar; Shultis, Michael W; Manetsch, Roman; Kyle, Dennis E

    2017-08-01

    Malaria-related mortality has slowly decreased over the past decade; however, eradication of malaria requires the development of new antimalarial chemotherapies that target liver stages of the parasite and combat the emergence of drug resistance. The diminishing arsenal of anti-liver-stage compounds sparked our interest in reviving the old and previously abandoned compound menoctone. In support of these studies, we developed a new convergent synthesis method that was facile, required fewer steps, produced better yields, and utilized less expensive reagents than the previously published method. Menoctone proved to be highly potent against liver stages of Plasmodium berghei (50 percent inhibitory concentration [IC 50 ] = 0.41 nM) and erythrocytic stages of Plasmodium falciparum (113 nM). We selected for resistance to menoctone and found M133I mutations in cytochrome b of both P. falciparum and P. berghei The same mutation has been observed previously in atovaquone resistance, and we confirmed cross-resistance between menoctone and atovaquone in vitro (for P. falciparum ) and in vivo (for P. berghei ). Finally, we assessed the transmission potential of menoctone-resistant P. berghei and found that the M133I mutant parasites were readily transmitted from mouse to mosquitoes and back to mice. In each step, the M133I mutation in cytochrome b , inducing menoctone resistance, was confirmed. In summary, this study is the first to show the mechanism of resistance to menoctone and that menoctone and atovaquone resistance is transmissible through mosquitoes. Copyright © 2017 American Society for Microbiology.

  6. Plasmon waveguide resonance spectroscopic evidence for differential binding of oxidized and reduced rhodobacter capsulatus cytochrome c(2) to the cytochrome bc(1) complex mediated by the conformation of the rieske iron-sulfur protein

    International Nuclear Information System (INIS)

    Devanathan, S.; Salamon, Z.; Tollin, G.; Fitch, J.C.; Meyer, T.E.; Berry, E.A.; Cusanovich, M.A.

    2007-01-01

    The dissociation constants for the binding of Rhodobacter capsulatus cytochrome c2 and its K93P mutant to the cytochrome bc1 complex embedded in a phospholipid bilayer were measured by plasmon waveguide resonance spectroscopy in the presence and absence of the inhibitor stigmatellin. The reduced form of cytochrome c2 strongly binds to reduced cytochrome bc1 (Kd = 0.02 M) but binds much more weakly to the oxidized form (Kd = 3.1 M). In contrast, oxidized cytochrome c2 binds to oxidized cytochrome bc1 in a biphasic fashion with Kd values of 0.11 and 0.58 M. Such a biphasic interaction is consistent with binding to two separate sites or conformations of oxidized cytochrome c2 and/or cytochrome bc1. However, in the presence of stigmatellin, we find that oxidized cytochrome c2 binds to oxidized cytochrome bc1 in a monophasic fashion with high affinity (Kd = 0.06 M) and reduced cytochrome c2 binds less strongly (Kd = 0.11 M) but ∼30-fold more tightly than in the absence of stigmatellin. Structural studies with cytochrome bc1, with and without the inhibitor stigmatellin, have led to the proposal that the Rieske protein is mobile, moving between the cytochrome b and cytochrome c1 components during turnover. In one conformation, the Rieske protein binds near the heme of cytochrome c1, while the cytochrome c2 binding site is also near the cytochrome c1 heme but on the opposite side from the Rieske site, where cytochrome c2 cannot directly interact with Rieske. However, the inhibitor, stigmatellin, freezes the Rieske protein iron-sulfur cluster in a conformation proximal to cytochrome b and distal to cytochrome c1. We conclude from this that the dual conformation of the Rieske protein is primarily responsible for biphasic binding of oxidized cytochrome c2 to cytochrome c1. This optimizes turnover by maximizing binding of the substrate, oxidized cytochrome c2, when the iron-sulfur cluster is proximal to cytochrome b and minimizing binding of the product, reduced cytochrome c

  7. In vitro effects of myricetin, morin, apigenin, (+)-taxifolin, (+)-catechin, (−)-epicatechin, naringenin and naringin on cytochrome b5 reduction by purified NADH-cytochrome b5 reductase

    International Nuclear Information System (INIS)

    Çelik, Haydar; Koşar, Müberra; Arinç, Emel

    2013-01-01

    Highlights: • We assessed inhibitory effects of 8 dietary flavonoids on cytochrome b5 reduction by purified NADH-cytochrome b5 reductase. • The flavonol myricetin was the most potent in inhibiting cytochrome b5 reduction with an IC 50 value of 0.35 μM. • We investigated kinetics of myricetin-induced inhibition in detail. • We explored the structure–inhibitory activity relationship of compounds. • Modulation of cytochrome b5 reduction indicates a potential for myricetin to lead to some food–drug/xenobiotic interactions. - Abstract: The microsomal NADH-dependent electron transport system consisting of cytochrome b5 reductase and cytochrome b5 participates in a number of physiologically important processes including lipid metabolism as well as is involved in the metabolism of various drug and xenobiotics. In the present study, we assessed the inhibitory effects of eight dietary flavonoids representing five distinct chemical classes on cytochrome b5 reduction by purified cytochrome b5 reductase. From the flavonoids tested, myricetin was the most potent in inhibiting cytochrome b5 reduction with an IC 50 value of 0.35 μM. Myricetin inhibited b5 reductase noncompetitively with a K i of 0.21 μM with respect to cofactor NADH, and exhibited a non-linear relationship indicating non-Michaelis–Menten kinetic binding with respect to cytochrome b5. In contrast to the potent inhibitory activity of myricetin, (+)-taxifolin was found to be a weak inhibitor (IC 50 = 9.8 μM). The remaining flavonoids were inactive within the concentration range tested (1–50 μM). Analysis of structure–activity data suggested that simultaneous presence of three OH groups in ring B is a primary structural determinant for a potent enzyme inhibition. Our results suggest that inhibition of the activity of this system by myricetin or myricetin containing diets may influence the metabolism of therapeutic drugs as well as detoxification of xenobiotics

  8. Study of the individual cytochrome b5 and cytochrome b5 reductase domains of Ncb5or reveals a unique heme pocket and a possible role of the CS domain.

    Science.gov (United States)

    Deng, Bin; Parthasarathy, Sudharsan; Wang, WenFang; Gibney, Brian R; Battaile, Kevin P; Lovell, Scott; Benson, David R; Zhu, Hao

    2010-09-24

    NADH cytochrome b(5) oxidoreductase (Ncb5or) is found in animals and contains three domains similar to cytochrome b(5) (b(5)), CHORD-SGT1 (CS), and cytochrome b(5) reductase (b(5)R). Ncb5or has an important function, as suggested by the diabetes and lipoatrophy phenotypes in Ncb5or null mice. To elucidate the structural and functional properties of human Ncb5or, we generated its individual b(5) and b(5)R domains (Ncb5or-b(5) and Ncb5or-b(5)R, respectively) and compared them with human microsomal b(5) (Cyb5A) and b(5)R (Cyb5R3). A 1.25 Å x-ray crystal structure of Ncb5or-b(5) reveals nearly orthogonal planes of the imidazolyl rings of heme-ligating residues His(89) and His(112), consistent with a highly anisotropic low spin EPR spectrum. Ncb5or is the first member of the cytochrome b(5) family shown to have such a heme environment. Like other b(5) family members, Ncb5or-b(5) has two helix-loop-helix motifs surrounding heme. However, Ncb5or-b(5) differs from Cyb5A with respect to location of the second heme ligand (His(112)) and of polypeptide conformation in its vicinity. Electron transfer from Ncb5or-b(5)R to Ncb5or-b(5) is much less efficient than from Cyb5R3 to Cyb5A, possibly as a consequence of weaker electrostatic interactions. The CS linkage probably obviates the need for strong interactions between b(5) and b(5)R domains in Ncb5or. Studies with a construct combining the Ncb5or CS and b(5)R domains suggest that the CS domain facilitates docking of the b(5) and b(5)R domains. Trp(114) is an invariant surface residue in all known Ncb5or orthologs but appears not to contribute to electron transfer from the b(5)R domain to the b(5) domain.

  9. A Phenomenological Study on Lack of Motivation

    Science.gov (United States)

    Educational Research and Reviews, 2013

    2013-01-01

    The aim of this research is to point out the underlying reasons about the lack of motivation at academic activities concerning Attribution Theory. Attribution Theory trys to understand how the people answer "why" question and how they do casual explanations. This research is a qualitative based research. It used the phenomenological…

  10. Metabolism of styrene to styrene oxide and vinylphenols in cytochrome P450 2F2- and P450 2E1-knockout mouse liver and lung microsomes.

    Science.gov (United States)

    Shen, Shuijie; Li, Lei; Ding, Xinxin; Zheng, Jiang

    2014-01-21

    Pulmonary toxicity of styrene is initiated by cytochromes P450-dependent metabolic activation. P450 2E1 and P450 2F2 are considered to be two main cytochrome P450 enzymes responsible for styrene metabolism in mice. The objective of the current study was to determine the correlation between the formation of styrene metabolites (i.e., styrene oxide and 4-vinylphenol) and pulmonary toxicity of styrene, using Cyp2e1- and Cyp2f2-null mouse models. A dramatic decrease in the formation of styrene glycol and 4-vinylphenol was found in Cyp2f2-null mouse lung microsomes relative to that in the wild-type mouse lung microsomes; however, no significant difference in the production of the styrene metabolites was observed between lung microsomes obtained from Cyp2e1-null and the wild-type mice. The knockout and wild-type mice were treated with styrene (6.0 mmol/kg, ip), and cell counts and LDH activity in bronchoalveolar lavage fluids were monitored to evaluate the pulmonary toxicity induced by styrene. Cyp2e1-null mice displayed a susceptibility to lung toxicity of styrene similar to that of the wild-type animals; however, Cyp2f2-null mice were resistant to styrene-induced pulmonary toxicity. In conclusion, both P450 2E1 and P450 2F2 are responsible for the metabolic activation of styrene. The latter enzyme plays an important role in styrene-induced pulmonary toxicity. Both styrene oxide and 4-vinylphenol are suggested to participate in the development of lung injury induced by styrene.

  11. Comparison of xenobiotic-metabolising human, porcine, rodent, and piscine cytochrome P450

    International Nuclear Information System (INIS)

    Burkina, Viktoriia; Rasmussen, Martin Krøyer; Pilipenko, Nadezhda; Zamaratskaia, Galia

    2017-01-01

    Highlights: • The percent identity of porcine, murine and piscine CYPs was compared with human CYPs. • Main similarities and differences were reviewed. • Understanding of molecular mechanisms of CYP system will provide further insights into the CYP regulatory processes, and responses to different factors. - Abstract: Cytochrome P450 proteins (CYP450s) are present in most domains of life and play a critical role in the metabolism of endogenous compounds and xenobiotics. The effects of exposure to xenobiotics depend heavily on the expression and activity of drug-metabolizing CYP450s, which is determined by species, genetic background, age, gender, diet, and exposure to environmental pollutants. Numerous reports have investigated the role of different vertebrate CYP450s in xenobiotic metabolism. Model organisms provide powerful experimental tools to investigate Phase I metabolism. The aim of the present review is to compare the existing data on human CYP450 proteins (1–3 families) with those found in pigs, mice, and fish. We will highlight differences and similarities and identify research gaps which need to be addressed in order to use these species as models that mimic human traits. Moreover, we will discuss the roles of nuclear receptors in the cellular regulation of CYP450 expression in select organisms.

  12. Cytochrome P450 metabolism of the post-lanosterol intermediates explains enigmas of cholesterol synthesis

    Science.gov (United States)

    Ačimovič, Jure; Goyal, Sandeep; Košir, Rok; Goličnik, Marko; Perše, Martina; Belič, Ales; Urlep, Žiga; Guengerich, F. Peter; Rozman, Damjana

    2016-06-01

    Cholesterol synthesis is among the oldest metabolic pathways, consisting of the Bloch and Kandutch-Russell branches. Following lanosterol, sterols of both branches are proposed to be dedicated to cholesterol. We challenge this dogma by mathematical modeling and with experimental evidence. It was not possible to explain the sterol profile of testis in cAMP responsive element modulator tau (Crem τ) knockout mice with mathematical models based on textbook pathways of cholesterol synthesis. Our model differs in the inclusion of virtual sterol metabolizing enzymes branching from the pathway. We tested the hypothesis that enzymes from the cytochrome P450 (CYP) superfamily can participate in the catalysis of non-classical reactions. We show that CYP enzymes can metabolize multiple sterols in vitro, establishing novel branching points of cholesterol synthesis. In conclusion, sterols of cholesterol synthesis can be oxidized further to metabolites not dedicated to production of cholesterol. Additionally, CYP7A1, CYP11A1, CYP27A1, and CYP46A1 are parts of a broader cholesterol synthesis network.

  13. Current status of prediction of drug disposition and toxicity in humans using chimeric mice with humanized liver.

    Science.gov (United States)

    Kitamura, Shigeyuki; Sugihara, Kazumi

    2014-01-01

    1. Human-chimeric mice with humanized liver have been constructed by transplantation of human hepatocytes into several types of mice having genetic modifications that injure endogenous liver cells. Here, we focus on liver urokinase-type plasminogen activator-transgenic severe combined immunodeficiency (uPA/SCID) mice, which are the most widely used human-chimeric mice. Studies so far indicate that drug metabolism, drug transport, pharmacological effects and toxicological action in these mice are broadly similar to those in humans. 2. Expression of various drug-metabolizing enzymes is known to be different between humans and rodents. However, the expression pattern of cytochrome P450, aldehyde oxidase and phase II enzymes in the liver of human-chimeric mice resembles that in humans, not that in the host mice. 3. Metabolism of various drugs, including S-warfarin, zaleplon, ibuprofen, naproxen, coumarin, troglitazone and midazolam, in human-chimeric mice is mediated by human drug-metabolizing enzymes, not by host mouse enzymes, and thus resembles that in humans. 4. Pharmacological and toxicological effects of various drugs in human-chimeric mice are also similar to those in humans. 5. The current consensus is that chimeric mice with humanized liver are useful to predict drug metabolism catalyzed by cytochrome P450, aldehyde oxidase and phase II enzymes in humans in vivo and in vitro. Some remaining issues are discussed in this review.

  14. Conceptualising the lack of health insurance coverage.

    Science.gov (United States)

    Davis, J B

    2000-01-01

    This paper examines the lack of health insurance coverage in the US as a public policy issue. It first compares the problem of health insurance coverage to the problem of unemployment to show that in terms of the numbers of individuals affected lack of health insurance is a problem comparable in importance to the problem of unemployment. Secondly, the paper discusses the methodology involved in measuring health insurance coverage, and argues that the current method of estimation of the uninsured underestimates the extent that individuals go without health insurance. Third, the paper briefly introduces Amartya Sen's functioning and capabilities framework to suggest a way of representing the extent to which individuals are uninsured. Fourth, the paper sketches a means of operationalizing the Sen representation of the uninsured in terms of the disability-adjusted life year (DALY) measure.

  15. Laura: Soybean variety lacking Kunitz trypsin inhibitor

    Directory of Open Access Journals (Sweden)

    Srebrić Mirjana

    2010-01-01

    Full Text Available Grain of conventional soybean varieties requires heat processing to break down trypsin inhibitor's activity before using as food or animal feed. At the same time, protein denaturation and other qualitative changes occur in soybean grain, especially if the temperature of heating is not controlled. Two types of trypsin inhibitor were found in soybean grain the Kunitz trypsin inhibitor and the Bowman-Birk inhibitor. Mature grain of soybean Laura is lacking Kunitz trypsin inhibitor. Grain yield of variety Laura is equal to high yielding varieties from the maturity group I, where it belongs. Lacking of Kunitz-trypsin inhibitor makes soybean grain suitable for direct feeding in adult non ruminant animals without previous thermal processing. Grain of variety Laura can be processed for a shorter period of time than conventional soybeans. This way we save energy, and preserve valuable nutritional composition of soybean grain, which is of interest in industrial processing.

  16. The amino acid sequence of cytochrome c from Cucurbita maxima L. (pumpkin)

    Science.gov (United States)

    Thompson, E. W.; Richardson, M.; Boulter, D.

    1971-01-01

    The amino acid sequence of pumpkin cytochrome c was determined on 2μmol of protein. Some evidence was found for the occurrence of two forms of cytochrome c, whose sequences differed in three positions. Pumpkin cytochrome c consists of 111 residues and is homologous with mitochondrial cytochromes c from other plants. Experimental details are given in a supplementary paper that has been deposited as Supplementary Publication SUP 50005 at the National Lending Library for Science and Technology, Boston Spa, Yorks. LS23 7BQ, U.K., from whom copies can be obtained on the terms indicated in Biochem. J. (1971), 121, 7. PMID:5131733

  17. Covalent Modification of Cytochrome C by Reactive Metabolites of Furan

    OpenAIRE

    Phillips, Martin B.; Sullivan, Mathilde M.; Villalta, Peter W.; Peterson, Lisa A.

    2013-01-01

    Metabolism of the hepatotoxicant furan leads to protein adduct formation in the target organ. The initial bioactivation step involves cytochrome P450-catalyzed oxidation of furan, generating cis-2-butene-1,4-dial (BDA). BDA reacts with lysine to form pyrrolin-2-one adducts. Metabolic studies indicate that BDA also reacts with glutathione (GSH) to generate 2-(S-glutathionyl)butanedial (GSH-BDA), which then reacts with lysine to form GSH-BDA-lysine cross-links. To explore the relative reactivit...

  18. Redox Thermodynamics of Cytochromes c Subjected to Urea Induced Unfolding

    OpenAIRE

    Monari, S.; Ranieri, A.; Di Rocco, G.; van der Zwan, G.; Peressini, S.; Tavagnacco, C.; Millo, D.; Borsari, M.

    2009-01-01

    The thermodynamics of the electron transfer (ET) process for beef heart and yeast cytochromes c and the Lys72Ala/Lys73Ala/Lys79Ala mutant of the latter species subjected to progressive urea-induced unfolding was determined electrochemically. The results indicate the presence of at least three protein forms which were assigned to a low-temperature and a high-temperature His-Met intermediate species and a bis-histidinate form (although the presence of a His-Lys form cannot be excluded). The muc...

  19. Enzymes activities involving bacterial cytochromes incorporated in clays

    International Nuclear Information System (INIS)

    Lojou, E.; Giudici-Orticoni, M.Th.; Bianco, P.

    2005-01-01

    With the development of bio electrochemistry, researches appeared on the enzymes immobilization at the surface of electrodes for the realization of bioreactors and bio sensors. One of the main challenges is the development of host matrix able to immobilize the protein material preserving its integrity. In this framework the authors developed graphite electrodes modified by clay films. These electrodes are examined for two enzyme reactions involving proteins of sulfate-reduction bacteria. Then in the framework of the hydrogen biological production and bioreactors for the environmental pollution de-pollution, the electrochemical behavior of the cytochrome c3 in two different clays deposed at the electrode is examined

  20. Lack of a Functioning P2X7 Receptor Leads to Increased Susceptibility to Toxoplasmic Ileitis.

    Directory of Open Access Journals (Sweden)

    Catherine M Miller

    Full Text Available Oral infection of C57BL/6J mice with the protozoan parasite Toxoplasma gondii leads to a lethal inflammatory ileitis.Mice lacking the purinergic receptor P2X7R are acutely susceptible to toxoplasmic ileitis, losing significantly more weight than C57BL/6J mice and exhibiting much greater intestinal inflammatory pathology in response to infection with only 10 cysts of T. gondii. This susceptibility is not dependent on the ability of P2X7R-deficient mice to control the parasite, which they accomplish just as efficiently as C57BL/6J mice. Rather, susceptibility is associated with elevated ileal concentrations of pro-inflammatory cytokines, reactive nitrogen intermediates and altered regulation of elements of NFκB activation in P2X7R-deficient mice.Our data support the thesis that P2X7R, a well-documented activator of pro-inflammatory cytokine production, also plays an important role in the regulation of intestinal inflammation.

  1. Reduction of reversed micelle entrapped cytochrome c and cytochrome c3 by electrons generated by pulse radiolysis or by pyrene photoionization

    International Nuclear Information System (INIS)

    Vlsser, A.J.W.G.; Fendler, J.H.

    1982-01-01

    Horse heart cytochrome c and cytochrome c 3 , isolated from Desulfovibrio vulgaris, have been incorporated in sodium bis(2-ethylhexyl)sulfosuccinate (AOT) entrapped water pools in heptane. The absorption spectra of the cytochromes have been found to be strongly dependent on the water to AOT concentration ratios. The proteins solubilized in heptane by the AOT reversed micelles have retained their ability to mediate electron transfer. They reacted very rapidly with hydrated electrons, generated pulse radiolytically or, alternatively, formed in the laser photoionization of pyrene

  2. Accidents in radiotherapy: Lack of quality assurance?

    International Nuclear Information System (INIS)

    Novotny, J.

    1997-01-01

    About 150 radiological accidents, involving more than 3000 patients with adverse effects, 15 patient's fatalities and about 5000 staff and public exposures have been collected and analysed. Out of 67 analysed accidents in external beam therapy 22% has been caused by wrong calculation of the exposure time or monitor units, 13% by inadequate review of patient's chart, 12% by mistakes in the anatomical area to be treated. The remaining 35% can be attributed to 17 different causes. The most common mistakes in brachytherapy were wrong activities of sources used for treatment (20%), inadequate procedures for placement of sources applicators (14%), mistakes in calculating the treatment time (12%), etc. The direct and contributing causes of radiological accidents have been deduced from each event, when it was possible and categorized into 9 categories: mistakes in procedures (30%), professional mistakes (17%), communication mistakes (15%), lack of training (8.5%), interpretation mistakes (7%), lack of supervision (6%), mistakes in judgement (6%), hardware failures (5%), software and other mistakes (5.5%). Three types of direct and contributing causes responsible for almost 62% of all accidents are directly connected to the quality assurance of treatment. The lessons learnt from the accidents are related to frequencies of direct and contributing factors and show that most of the accident are caused by lack, non-application of quality assurance (QA) procedures or by underestimating of QA procedures. The international system for collection of accidents and dissemination of lessons learnt from the different accidents, proposed by IAEA, can contribute to better practice in many radiotherapy departments. Most of the accidents could have been avoided, had a comprehensive QA programme been established and properly applied in all radiotherapy departments, whatever the size. (author)

  3. Why does Colombia lack agricultural commodity futures?

    Directory of Open Access Journals (Sweden)

    Pablo Moreno-Alemay

    2015-11-01

    Full Text Available This article explores the reasons why futures contracts are not traded as an alternative to price hedging for agricultural goods in Colombia. Based on surveys, interviews and statistical analysis, this study identified that conceptual gaps in contract negotiation, lack of consensus in the agricultural sector regarding the use of financial mechanisms and the sector’s infrequent contact with Colombia’s financial institutions, are the main reasons why a futures contracts market has not emerged.

  4. Modulation of expression and activity of cytochrome P450s and alteration of praziquantel kinetics during murine schistosomiasis

    Directory of Open Access Journals (Sweden)

    Mara A Gotardo

    2011-03-01

    Full Text Available In this study, we investigated the expression and activity of liver cytochrome P450s (CYPs and praziquantel (PZQ kinetics in mice infected with Schistosoma mansoni. Swiss Webster (SW mice of both genders were infected (100 cercariae on postnatal day 10 and killed on post-infection days (PIDs 30 or 55. Non-infected mice of the same age and sex served as controls. Regardless of mouse sex, infection depressed the activities of CYP1A [ethoxy/methoxy-resorufin-O-dealkylases (EROD/MROD], 2B9/10 [pentoxy/benzyloxy-resorufin-O-dealkylases (PROD, BROD], 2E1 [p-nitrophenol-hydroxylase (PNPH] and 3A11 [erythromycin N-demethylase (END] on PID 55 but not on PID 30. On PID 55, infection decreased liver CYP mRNA levels (real-time reverse transcription-polymerase chain reaction. On PID 30, whereas mRNA levels remained unaltered in males, they were depressed in females. Plasma PZQ (200 and 400 mg/kg body weight intraperitoneally levels were measured (high-performance liquid chromatography at different post-treatment intervals. In males and females, infection delayed the PZQ clearance on PID 55, but not on PID 30. Therefore, it can be concluded that schistosomiasis down-modulated CYP expression and activity and delayed PZQ clearance on PID 55, when a great number of parasite eggs were lodged in the liver. On PID 30, when egg-laying was initiated by the worms, no change of CYP expression and activity was found, except for a depression of CYP1A2 and 3A11 mRNAs in female mice.

  5. A cytosolic cytochrome b 5-like protein in yeast cell accelerating the electron transfer from NADPH to cytochrome c catalyzed by Old Yellow Enzyme

    International Nuclear Information System (INIS)

    Nakagawa, Manabu; Yamano, Toshio; Kuroda, Kiyo; Nonaka, Yasuki; Tojo, Hiromasa; Fujii, Shigeru

    2005-01-01

    A 410-nm absorbing species which enhanced the reduction rate of cytochrome c by Old Yellow Enzyme (OYE) with NADPH was found in Saccharomyces cerevisiae. It was solubilized together with OYE by the treatment of yeast cells with 10% ethyl acetate. The purified species showed visible absorption spectra in both oxidized and reduced forms, which were the same as those of the yeast microsomal cytochrome b 5 . At least 14 amino acid residues of the N-terminal region coincided with those of yeast microsomal b 5 , but the protein had a lower molecular weight determined to be 12,600 by SDS-PAGE and 9775 by mass spectrometry. The cytochrome b 5 -like protein enhanced the reduction rate of cytochrome c by OYE, and a plot of the reduction rates against its concentration showed a sigmoidal curve with an inflexion point at 6 x 10 -8 M of the protein

  6. Antimycin-insensitive mutants of Candida utilis II. The effects of antimycin on Cytochrome b

    DEFF Research Database (Denmark)

    Grimmelikhuijzen, C J; Marres, C A; Slater, Conor

    1975-01-01

    1. Cytochrome b-562 is more reduced in submitochondrial particles of mutant 28 during the aerobic steady-state respiration with succinate than in particles of the wild type. When anaerobiosis is reached, the reduction of cytochrome b is preceded by a rapid reoxidation in the mutnat. A similar reo...

  7. Electrochemical determination of hydrogen peroxide using Rhodobacter capsulatus cytochrome c peroxidase at a gold electrode

    NARCIS (Netherlands)

    De Wael, K.; Buschop, H.; Heering, H.A.; De Smet, L.; Van Beeumen, J.; Devreese, B.; Adriaens, A.

    2007-01-01

    We describe the redox behaviour of horse heart cytochrome c (HHC) and Rhodobacter capsulatus cytochrome c peroxidase (RcCCP) at a gold electrode modified with 4,4?-bipyridyl. RcCCP shows no additional oxidation or reduction peaks compared to the electrochemistry of only HHC, which indicates that it

  8. Immobilized unfolded cytochrome c acts as a catalyst for dioxygen reduction.

    Science.gov (United States)

    Tavagnacco, Claudio; Monari, Stefano; Ranieri, Antonio; Bortolotti, Carlo Augusto; Peressini, Silvia; Borsari, Marco

    2011-10-21

    Unfolding turns immobilized cytochrome c into a His-His ligated form endowed with catalytic activity towards O(2), which is absent in the native protein. Dioxygen could be used by naturally occurring unfolded cytochrome c as a substrate for the production of partially reduced oxygen species (PROS) contributing to the cell oxidative stress.

  9. Effect of carbon source on the accumulation of cytochrome P-450 in the yeast Saccharomyces cerevisiae.

    Science.gov (United States)

    Kärenlampi, S O; Marin, E; Hänninen, O O

    1981-02-15

    The appearance of cytochrome P-450 in the yeast Saccharomyces cerevisiae depended on the substrate supporting growth. Cytochrome P-450 was apparent in yeast cells grown on a strongly fermentable sugar such as D-glucose, D-fructose or sucrose. When yeast was grown on D-galactose, D-mannose or maltose, where fermentation and respiration occurred concomitantly, cytochrome P-450 was also formed. The cytochrome P-450 concentration was maximal at the beginning of the stationary phase of the culture. Thereafter the concentration decreased, reaching zero at a late-stationary phase. When the yeast was grown on a medium that contained lactose or pentoses (L-arabinose, L-rhamnose, D-ribose and D-xylose), cytochrome P-450 did not occur. When a non-fermentable energy source (glycerol, lactate or ethanol) was used, no cytochrome P-450 was detectable. Transfer of cells from D-glucose medium to ethanol medium caused a slow disappearance of cytochrome P-450, although the amount of the haemoprotein still continued to increase in the control cultures. Cytochrome P-450 appeared thus to accumulate in conditions where the rate of growth was fast and fermentation occurred. Occurrence of this haemoprotein is not necessarily linked, however, with the repression of mitochondrial haemoprotein synthesis.

  10. The functional localization of cytochromes b in the respiratory chain of anaerobically grown Proteus mirabilis

    NARCIS (Netherlands)

    Van Wielink, J E; Reijnders, W N; Van Spanning, R J; Oltmann, L F; Stouthamer, A.H.

    1986-01-01

    The functional localization of the cytochromes b found in anaerobically grown Proteus mirabilis was investigated. From light absorption spectra, scanned during uninhibited and HQNO-inhibited electron transport to various electron acceptors, it was concluded that all cytochromes b function between

  11. Lack of consensus in social systems

    Science.gov (United States)

    Benczik, I. J.; Benczik, S. Z.; Schmittmann, B.; Zia, R. K. P.

    2008-05-01

    We propose an exactly solvable model for the dynamics of voters in a two-party system. The opinion formation process is modeled on a random network of agents. The dynamical nature of interpersonal relations is also reflected in the model, as the connections in the network evolve with the dynamics of the voters. In the infinite time limit, an exact solution predicts the emergence of consensus, for arbitrary initial conditions. However, before consensus is reached, two different metastable states can persist for exponentially long times. One state reflects a perfect balancing of opinions, the other reflects a completely static situation. An estimate of the associated lifetimes suggests that lack of consensus is typical for large systems.

  12. The Pentapeptide RM-131 Promotes Food Intake and Adiposity in Wildtype Mice but Not in Mice Lacking the Ghrelin Receptor

    DEFF Research Database (Denmark)

    Fischer, Katrin; Finan, Brian; Clemmensen, Christoffer

    2014-01-01

    The gastrointestinal peptide hormone ghrelin is the endogenous ligand of the growth hormone secretagogue receptor (a.k.a. ghrelin receptor, GHR). Currently, ghrelin is the only circulating peripheral hormone with the ability to promote a positive energy balance by stimulating food intake while...... decreasing energy expenditure and body fat utilization, as defined in rodents. Based on these and additional, beneficial effects on metabolism, the endogenous ghrelin system is considered an attractive target to treat diverse pathological conditions including those associated with eating/wasting disorders...... and cachexia. As the pharmacological potential of ghrelin is hampered by its relatively short half-life, ghrelin analogs with enhanced pharmacokinetics offer the potential to sustainably improve metabolism. One of these ghrelin analogs is the pentapeptide RM-131, which promotes food intake and adiposity...

  13. Effectiveness of cytochrome C and cepharanthin for leukopenia following multidisciplinary treatment

    International Nuclear Information System (INIS)

    Tabata, Kumiko; Endow, Masaru; Suzuki, Hirotoshi

    1986-01-01

    Leukopenia is one of important problems for multidisciplinary treatment of malignant tumor. We could not be able to take a continuous cancer therapy because of leukopenia. And then we had a study of effectiveness combination treatment of cytochrome C with cepharanthin for leukopenia of cancer patient. We carried on the study of 3 classifications of treatment as follows, a) cytochrome C only, b) combined cytochrome C with cepharanthin, and c) control group without drugs. Bone marrow potentiality is individual differentiation and then the group was administrated both cytochrome C and cepharanthin following radiotherapy associated with postoperative breast cancer. The above description lead to conclusion that combination treatment of cytochrome C and cepharanthin was available for protective drugs from multidisciplinary treatment induced leukemia. (author)

  14. Acrolein, A Reactive Product of Lipid Peroxidation, Induces Oxidative Modification of Cytochrome c

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Jung Hoon [Cheongju Univ., Cheongju (Korea, Republic of)

    2013-11-15

    Acrolein (ACR) is a well-known carbonyl toxin produced by lipid peroxidation of polyunsaturated fatty acids, which is involved in the pathogenesis of neurodegenerative disorders such as Alzheimer's disease (AD). In Alzheimer's brain, ACR was found to be elevated in hippocampus and temporal cortex where oxidative stress is high. In this study, we evaluated oxidative modification of cytochrome c occurring after incubation with ACR. When cytochrome c was incubated with ACR, protein aggregation increased in a dose-dependent manner. The formation of carbonyl compounds and the release of iron were obtained in ACR-treated cytochrome c. Reactive oxygen species scavengers and iron specific chelator inhibited the ACR-mediated cytochrome c modification and carbonyl compound formation. Our data demonstrate that oxidative damage of cytochrome c by ACR might induce disruption of cyotochrome c structure and iron mishandling as a contributing factor to the pathology of AD.

  15. Acrolein, A Reactive Product of Lipid Peroxidation, Induces Oxidative Modification of Cytochrome c

    International Nuclear Information System (INIS)

    Kang, Jung Hoon

    2013-01-01

    Acrolein (ACR) is a well-known carbonyl toxin produced by lipid peroxidation of polyunsaturated fatty acids, which is involved in the pathogenesis of neurodegenerative disorders such as Alzheimer's disease (AD). In Alzheimer's brain, ACR was found to be elevated in hippocampus and temporal cortex where oxidative stress is high. In this study, we evaluated oxidative modification of cytochrome c occurring after incubation with ACR. When cytochrome c was incubated with ACR, protein aggregation increased in a dose-dependent manner. The formation of carbonyl compounds and the release of iron were obtained in ACR-treated cytochrome c. Reactive oxygen species scavengers and iron specific chelator inhibited the ACR-mediated cytochrome c modification and carbonyl compound formation. Our data demonstrate that oxidative damage of cytochrome c by ACR might induce disruption of cyotochrome c structure and iron mishandling as a contributing factor to the pathology of AD

  16. Cytochromes c': Structure, Reactivity and Relevance to Haem-Based Gas Sensing.

    Science.gov (United States)

    Hough, Michael A; Andrew, Colin R

    2015-01-01

    Cytochromes c' are a group of class IIa cytochromes with pentacoordinate haem centres and are found in photosynthetic, denitrifying and methanotrophic bacteria. Their function remains unclear, although roles in nitric oxide (NO) trafficking during denitrification or in cellular defence against nitrosoative stress have been proposed. Cytochromes c' are typically dimeric with each c-type haem-containing monomer folding as a four-α-helix bundle. Their hydrophobic and crowded distal sites impose severe restrictions on the binding of distal ligands, including diatomic gases. By contrast, NO binds to the proximal haem face in a similar manner to that of the eukaryotic NO sensor, soluble guanylate cyclase and bacterial analogues. In this review, we focus on how structural features of cytochromes c' influence haem spectroscopy and reactivity with NO, CO and O2. We also discuss the relevance of cytochrome c' to understanding the mechanisms of gas binding to haem-based sensor proteins. © 2015 Elsevier Ltd. All rights reserved.

  17. Cytochrome c and c1 heme lyases are essential in Plasmodium berghei.

    Science.gov (United States)

    Posayapisit, Navaporn; Songsungthong, Warangkhana; Koonyosying, Pongpisid; Falade, Mofolusho O; Uthaipibull, Chairat; Yuthavong, Yongyuth; Shaw, Philip J; Kamchonwongpaisan, Sumalee

    Malaria parasites possess a de novo heme synthetic pathway. Interestingly, this pathway is dispensable during the blood stages of development in mammalian hosts. The assembly of the two most important hemeproteins, cytochromes c and c1, is mediated by cytochrome heme lyase enzymes. Plasmodium spp. possess two cytochrome heme lyases encoded by separate genes. Given the redundancy of heme synthesis, we sought to determine if heme lyase function also exhibits redundancy. To answer this question, we performed gene knockout experiments. We found that the PBANKA_143950 and PBANKA_0602600 Plasmodium berghei genes encoding cytochrome c (Pbcchl) and cytochrome c1 (Pbcc 1 hl) heme lyases, respectively, can only be disrupted when a complementary gene is present. In contrast, four genes in the de novo heme synthesis pathway can be disrupted without complementation. This work provides evidence that Pbcchl and Pbcc 1 hl are both essential and thus may be antimalarial targets. Copyright © 2016 Elsevier B.V. All rights reserved.

  18. Total synthesis of cytochrome b562 by native chemical ligation using a removable auxiliary

    Science.gov (United States)

    Low, Donald W.; Hill, Michael G.; Carrasco, Michael R.; Kent, Stephen B. H.; Botti, Paolo

    2001-01-01

    We have completed the total chemical synthesis of cytochrome b562 and an axial ligand analogue, [SeMet7]cyt b562, by thioester-mediated chemical ligation of unprotected peptide segments. A novel auxiliary-mediated native chemical ligation that enables peptide ligation to be applied to protein sequences lacking cysteine was used. A cleavable thiol-containing auxiliary group, 1-phenyl-2-mercaptoethyl, was added to the α-amino group of one peptide segment to facilitate amide bond-forming ligation. The amine-linked 1-phenyl-2-mercaptoethyl auxiliary was stable to anhydrous hydrogen fluoride used to cleave and deprotect peptides after solid-phase peptide synthesis. Following native chemical ligation with a thioester-containing segment, the auxiliary group was cleanly removed from the newly formed amide bond by treatment with anhydrous hydrogen fluoride, yielding a full-length unmodified polypeptide product. The resulting polypeptide was reconstituted with heme and folded to form the functional protein molecule. Synthetic wild-type cyt b562 exhibited spectroscopic and electrochemical properties identical to the recombinant protein, whereas the engineered [SeMet7]cyt b562 analogue protein was spectroscopically and functionally distinct, with a reduction potential shifted by ≈45 mV. The use of the 1-phenyl-2-mercaptoethyl removable auxiliary reported here will greatly expand the applicability of total protein synthesis by native chemical ligation of unprotected peptide segments. PMID:11390992

  19. The human genome project and novel aspects of cytochrome P450 research

    International Nuclear Information System (INIS)

    Ingelman-Sundberg, Magnus

    2005-01-01

    Currently, 57 active cytochrome P450 (CYP) genes and 58 pseudogenes are known to be present in the human genome. Among the genes discovered by initiatives in the human genome project are CYP2R1, CYP2W1, CYP2S1, CYP2U1 and CYP3A43, the latter apparently encoding a pseudoenzyme. The function, polymorphism and regulation of these genes are still to be discovered to a great extent. The polymorphism of drug metabolizing CYPs is extensive and influences the outcome of drug therapy causing lack of response or adverse drug reactions. The basis for the differences in the global distribution of the polymorphic variants is inactivating gene mutations and subsequent genetic drift. However, polymorphic alleles carrying multiple active gene copies also exist and are suggested in case of CYP2D6 to be caused by positive selection due to development of alkaloid resistance in North East Africa about 10,000-5000 BC. The knowledge about the CYP genes and their polymorphisms is of fundamental importance for effective drug therapy and for drug development as well as for understanding metabolic activation of carcinogens and other xenobiotics. Here, a short review of the current knowledge is given

  20. Mam33 promotes cytochrome c oxidase subunit I translation in Saccharomyces cerevisiae mitochondria.

    Science.gov (United States)

    Roloff, Gabrielle A; Henry, Michael F

    2015-08-15

    Three mitochondrial DNA-encoded proteins, Cox1, Cox2, and Cox3, comprise the core of the cytochrome c oxidase complex. Gene-specific translational activators ensure that these respiratory chain subunits are synthesized at the correct location and in stoichiometric ratios to prevent unassembled protein products from generating free oxygen radicals. In the yeast Saccharomyces cerevisiae, the nuclear-encoded proteins Mss51 and Pet309 specifically activate mitochondrial translation of the largest subunit, Cox1. Here we report that Mam33 is a third COX1 translational activator in yeast mitochondria. Mam33 is required for cells to adapt efficiently from fermentation to respiration. In the absence of Mam33, Cox1 translation is impaired, and cells poorly adapt to respiratory conditions because they lack basal fermentative levels of Cox1. © 2015 Roloff and Henry. This article is distributed by The American Society for Cell Biology under license from the author(s). Two months after publication it is available to the public under an Attribution–Noncommercial–Share Alike 3.0 Unported Creative Commons License (http://creativecommons.org/licenses/by-nc-sa/3.0).

  1. Cytotoxic 1-deoxysphingolipids are metabolized by a cytochrome P450-dependent pathway.

    Science.gov (United States)

    Alecu, Irina; Othman, Alaa; Penno, Anke; Saied, Essa M; Arenz, Christoph; von Eckardstein, Arnold; Hornemann, Thorsten

    2017-01-01

    The 1-deoxysphingolipids (1-deoxySLs) are atypical sphingolipids (SLs) that are formed when serine palmitoyltransferase condenses palmitoyl-CoA with alanine instead of serine during SL synthesis. The 1-deoxySLs are toxic to neurons and pancreatic β-cells. Pathologically elevated 1-deoxySLs cause the inherited neuropathy, hereditary sensory autonomic neuropathy type 1 (HSAN1), and are also found in T2D. Diabetic sensory polyneuropathy (DSN) and HSAN1 are clinically very similar, suggesting that 1-deoxySLs may be implicated in both pathologies. The 1-deoxySLs are considered to be dead-end metabolites, as they lack the C1-hydroxyl group, which is essential for the canonical degradation of SLs. Here, we report a previously unknown metabolic pathway, which is capable of degrading 1-deoxySLs. Using a variety of metabolic labeling approaches and high-resolution high-accuracy MS, we identified eight 1-deoxySL downstream metabolites, which appear to be formed by cytochrome P450 (CYP)4F enzymes. Comprehensive inhibition and induction of CYP4F enzymes blocked and stimulated, respectively, the formation of the downstream metabolites. Consequently, CYP4F enzymes might be novel therapeutic targets for the treatment of HSAN1 and DSN, as well as for the prevention of T2D. Copyright © 2017 by the American Society for Biochemistry and Molecular Biology, Inc.

  2. Linkage disequilibrium in wild mice.

    Directory of Open Access Journals (Sweden)

    Cathy C Laurie

    2007-08-01

    Full Text Available Crosses between laboratory strains of mice provide a powerful way of detecting quantitative trait loci for complex traits related to human disease. Hundreds of these loci have been detected, but only a small number of the underlying causative genes have been identified. The main difficulty is the extensive linkage disequilibrium (LD in intercross progeny and the slow process of fine-scale mapping by traditional methods. Recently, new approaches have been introduced, such as association studies with inbred lines and multigenerational crosses. These approaches are very useful for interval reduction, but generally do not provide single-gene resolution because of strong LD extending over one to several megabases. Here, we investigate the genetic structure of a natural population of mice in Arizona to determine its suitability for fine-scale LD mapping and association studies. There are three main findings: (1 Arizona mice have a high level of genetic variation, which includes a large fraction of the sequence variation present in classical strains of laboratory mice; (2 they show clear evidence of local inbreeding but appear to lack stable population structure across the study area; and (3 LD decays with distance at a rate similar to human populations, which is considerably more rapid than in laboratory populations of mice. Strong associations in Arizona mice are limited primarily to markers less than 100 kb apart, which provides the possibility of fine-scale association mapping at the level of one or a few genes. Although other considerations, such as sample size requirements and marker discovery, are serious issues in the implementation of association studies, the genetic variation and LD results indicate that wild mice could provide a useful tool for identifying genes that cause variation in complex traits.

  3. Cloning Mice.

    Science.gov (United States)

    Ogura, Atsuo

    2017-08-01

    Viable and fertile mice can be generated by somatic nuclear transfer into enucleated oocytes, presumably because the transplanted somatic cell genome becomes reprogrammed by factors in the oocyte. The first somatic cloned offspring of mice were obtained by directly injecting donor nuclei into recipient enucleated oocytes. When this method is used (the so-called Honolulu method of somatic cell nuclear transfer [SCNT]), the donor nuclei readily and completely condense within the enucleated metaphase II-arrested oocytes, which contain high levels of M-phase-promoting factor (MPF). It is believed that the condensation of the donor chromosomes promotes complete reprogramming of the donor genome within the mouse oocytes. Another key to the success of mouse cloning is the use of blunt micropipettes attached to a piezo impact-driving micromanipulation device. This system saves a significant amount of time during the micromanipulation of oocytes and thus minimizes the loss of oocyte viability in vitro. For example, a group of 20 oocytes can be enucleated within 10 min by an experienced operator. This protocol is composed of seven parts: (1) preparing micropipettes, (2) setting up the enucleation and injection micropipettes, (3) collecting and enucleating oocytes, (4) preparing nucleus donor cells, (5) injecting donor nuclei, (6) activating embryos and culturing, and (7) transferring cloned embryos. © 2017 Cold Spring Harbor Laboratory Press.

  4. Marine copepod cytochrome P450 genes and their applications for molecular ecotoxicological studies in response to oil pollution.

    Science.gov (United States)

    Han, Jeonghoon; Won, Eun-Ji; Kang, Hye-Min; Lee, Min-Chul; Jeong, Chang-Bum; Kim, Hui-Su; Hwang, Dae-Sik; Lee, Jae-Seong

    2017-11-30

    Recently, accidental spills of heavy oil have caused adverse effects in marine organisms. Oil pollution can induce damages on development and reproduction, linking with detrimental effects on diverse molecular levels of genes and proteins in plankton and fish. However, most information was mainly focused on marine vertebrates and consequently, limited information was available in marine invertebrates. Furthermore, there is still a lack of knowledge bridging in vivo endpoints with the functional regulation of cytochrome P450 (CYP) genes in response to oil spill pollution in marine invertebrates. In this paper, adverse effects of oil spill pollution in marine invertebrates are summarized with the importance of CYP genes as a potential biomarker, applying for environmental monitoring to detect oil spill using marine copepods. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. Mice lacking the PACAP type I receptor have impaired photic entrainment and negative masking

    DEFF Research Database (Denmark)

    Hannibal, J.; Brabet, P.; Fahrenkrug, J.

    2008-01-01

    The retinohypothalamic tract (RHT) is a retinofugal neuronal pathway which, in mammals, mediates nonimage-forming vision to various areas in the brain involved in circadian timing, masking behavior, and regulation of the pupillary light reflex. The RHT costores the two neurotransmitters glutamate...... intensities. Our findings substantiate a role for PACAP/PAC1 receptor signaling in nonimage-forming vision and indicate that the system is particularly important at lower light intensities Udgivelsesdato: 2008/12...

  6. Mice lacking pituitary tumor transforming gene show elevated exposure of DGalNAc carbohydrate determinants

    Directory of Open Access Journals (Sweden)

    Lutsyk A. D.

    2012-04-01

    Full Text Available Aim. To investigate the influence of pituitary tumor transforming gene (pttg-1 knockout on glycome of parenchimal organs by means of lectin histochemistry. Methods. DGalNAc, DGlcNAc, NeuNAc carbohydrate determinants were labelled with soybean agglutinin (SBA and wheat germ agglutinin (WGA, conjugated to peroxidase, with subsequent visualization of the lectin-binding sites with diaminobenzidine. The testes and kidneys of murine strain BL6/C57 with the pttg-1 gene knockout (PTTG-KO were compared to the wild type (PTTG-WT animals, both groups 1 month of age. Results. Knockout of the pttg-1 gene was accompanied by enhanced exposure of the DGalNAc sugar residues within the Golgi complex of secondary spermatocytes, in a brush border of renal tubules and on the lumenal surface of collecting ducts. Conclusions. This study suggests that knockout of the pttg-1 gene may lead to the changes in carbohydrate processing in mammalian organism.

  7. Antipsychotic-induced catalepsy is attenuated in mice lacking the M4 muscarinic acetylcholine receptor

    DEFF Research Database (Denmark)

    Fink-Jensen, Anders; Schmidt, Lene S; Dencker, Ditte

    2011-01-01

    of the striatum, suggesting a role for muscarinic M4 receptors in the motor side effects of antipsychotics, and in the alleviation of these side effects by anticholinergics. Here we investigated the potential role of the muscarinic M4 receptor in catalepsy induced by antipsychotics (haloperidol and risperidone...

  8. Lack of protection against ebola virus from chloroquine in mice and hamsters.

    Science.gov (United States)

    Falzarano, Darryl; Safronetz, David; Prescott, Joseph; Marzi, Andrea; Feldmann, Friederike; Feldmann, Heinz

    2015-06-01

    The antimalarial drug chloroquine has been suggested as a treatment for Ebola virus infection. Chloroquine inhibited virus replication in vitro, but only at cytotoxic concentrations. In mouse and hamster models, treatment did not improve survival. Chloroquine is not a promising treatment for Ebola. Efforts should be directed toward other drug classes.

  9. Lack of myeloid Fatp1 increases atherosclerotic lesion size in Ldlr-/- mice

    Science.gov (United States)

    Altered metabolism is an important regulator of macrophage (MF) phenotype, which contributes to inflammatory diseases such as atherosclerosis. Broadly, pro-inflammatory, classically-activated MFs (CAM) are glycolytic while alternatively-activated MFs (AAM) oxidize fatty acids, although there is prof...

  10. Spdef null mice lack conjunctival goblet cells and provide a model of dry eye

    NARCIS (Netherlands)

    Marko, C.K.; Menon, B.B.; Chen, G.; Whitsett, J.A.; Clevers, H.; Gipson, I.K.

    2013-01-01

    Goblet cell numbers decrease within the conjunctival epithelium in drying and cicatrizing ocular surface diseases. Factors regulating goblet cell differentiation in conjunctival epithelium are unknown. Recent data indicate that the transcription factor SAM-pointed domain epithelial-specific

  11. The production of ammonia by multiheme cytochromes C.

    Science.gov (United States)

    Simon, Jörg; Kroneck, Peter M H

    2014-01-01

    The global biogeochemical nitrogen cycle is essential for life on Earth. Many of the underlying biotic reactions are catalyzed by a multitude of prokaryotic and eukaryotic life forms whereas others are exclusively carried out by microorganisms. The last century has seen the rise of a dramatic imbalance in the global nitrogen cycle due to human behavior that was mainly caused by the invention of the Haber-Bosch process. Its main product, ammonia, is a chemically reactive and biotically favorable form of bound nitrogen. The anthropogenic supply of reduced nitrogen to the biosphere in the form of ammonia, for example during environmental fertilization, livestock farming, and industrial processes, is mandatory in feeding an increasing world population. In this chapter, environmental ammonia pollution is linked to the activity of microbial metalloenzymes involved in respiratory energy metabolism and bioenergetics. Ammonia-producing multiheme cytochromes c are discussed as paradigm enzymes.

  12. The Membrane Modulates Internal Proton Transfer in Cytochrome c Oxidase

    DEFF Research Database (Denmark)

    Öjemyr, Linda Nasvik; Ballmoos, Christoph von; Faxén, Kristina

    2012-01-01

    The functionality of membrane proteins is often modulated by the surrounding membrane. Here, we investigated the effect of membrane reconstitution of purified cytochrome c oxidase (CytcO) on the kinetics and thermodynamics of internal electron and proton-transfer reactions during O-2 reduction...... DOPC lipids. In conclusion, the data show that the membrane significantly modulates internal charge-transfer reactions and thereby the function of the membrane-bound enzyme.......-glycerol) (DOPG). In addition, a small Change in the internal Cu-A-heme a electron equilibrium constant was observed. This effect was lipid-dependent and explained in terms of a lower electrostatic potential within the membrane-spanning part of the protein with the anionic DOPG lipids than with the zwitterionic...

  13. Cytochrome P450 polymorphism and postoperative cognitive dysfunction

    DEFF Research Database (Denmark)

    Steinmetz, J; Jespersgaard, Cathrine; Dalhoff, Kim Peder

    2012-01-01

    neuropsychological testing at one week had POCD, and 24 out of 307 (7.8%) had POCD at three months. None of the examined CYP2C19, 2D6 alleles, or various phenotypes were significantly associated with POCD. CONCLUSION: Polymorphisms in CYP2C19, or 2D6 genes do not seem to be related to the occurrence of cognitive......BACKGROUND:The etiology of postoperative cognitive dysfunction (POCD) remains unclear but toxicity of anesthetic drugs and their metabolites could be important. We aimed to assess the possible association between POCD after propofol anesthesia and various phenotypes owing to polymorphisms...... in cytochrome P450 encoding genes. METHODS:We included patients who underwent non-cardiac surgery under total intravenous anesthesia with propofol. POCD was identified using a neuropsychological test-battery administered preoperatively, one week, and three months after surgery. Genotyping of CYP2C19*2, *3, CYP2...

  14. Role of cytochrome P450 in drug interactions

    Directory of Open Access Journals (Sweden)

    Bibi Zakia

    2008-10-01

    Full Text Available Abstract Drug-drug interactions have become an important issue in health care. It is now realized that many drug-drug interactions can be explained by alterations in the metabolic enzymes that are present in the liver and other extra-hepatic tissues. Many of the major pharmacokinetic interactions between drugs are due to hepatic cytochrome P450 (P450 or CYP enzymes being affected by previous administration of other drugs. After coadministration, some drugs act as potent enzyme inducers, whereas others are inhibitors. However, reports of enzyme inhibition are very much more common. Understanding these mechanisms of enzyme inhibition or induction is extremely important in order to give appropriate multiple-drug therapies. In future, it may help to identify individuals at greatest risk of drug interactions and adverse events.

  15. Advances in molecular modeling of human cytochrome P450 polymorphism.

    Science.gov (United States)

    Martiny, Virginie Y; Miteva, Maria A

    2013-11-01

    Cytochrome P450 (CYP) is a supergene family of metabolizing enzymes involved in the phase I metabolism of drugs and endogenous compounds. CYP oxidation often leads to inactive drug metabolites or to highly toxic or carcinogenic metabolites involved in adverse drug reactions (ADR). During the last decade, the impact of CYP polymorphism in various drug responses and ADR has been demonstrated. Of the drugs involved in ADR, 56% are metabolized by polymorphic phase I metabolizing enzymes, 86% among them being CYP. Here, we review the major CYP polymorphic forms, their impact for drug response and current advances in molecular modeling of CYP polymorphism. We focus on recent studies exploring CYP polymorphism performed by the use of sequence-based and/or protein-structure-based computational approaches. The importance of understanding the molecular mechanisms related to CYP polymorphism and drug response at the atomic level is outlined. © 2013.

  16. Differentially regulated NADPH: cytochrome p450 oxidoreductases in parsely

    International Nuclear Information System (INIS)

    Koopmann, E.; Hahlbrock, K.

    1997-01-01

    Two NADPH:cytochrome P450 oxidoreductases (CPRs) from parsley (Petroselinum crispum) were cloned, and the complete proteins were expressed and functionally identified in yeast. The two enzymes, designated CPR1 and CPR2, are 80% identical in amino acid sequence with one another and about 75% identical with CPRs from several other plant species. The mRNA accumulation patterns for CPR1 and CPR2 in fungal elicitor-treated or UV-irradiated cultured parsley cells and in developing or infected parsley plants were compared with those for cinnamate 4-hydroxylase (C4H), one of the most abundant CPR-dependent P450 enzymes in plants. All treatments strongly induced the mRNAs for C4H and CPR1 but not for CPR2, suggesting distinct metabolic roles of CPR1 and CPR2 and a functional relationship between CPR1 and C4H

  17. Stability enhancement of cytochrome c through heme deprotonation and mutations

    OpenAIRE

    Sonoyama, Takafumi; Hasegawa, Jun; Uchiyama, Susumu; Nakamura, Shota; Kobayashi, Yuji; Sambongi, Yoshihiro

    2009-01-01

    The chemical denaturation of Pseudomonas aeruginosa cytochrome c551 variants was examined at pH 5.0 and 3.6. All variants were stabilized at both pHs compared with the wild-type. Remarkably, the variants carrying the F34Y and/or E43Y mutations were more stabilized than those having the F7A/V13M or V78I ones at pH 5.0 compared with at pH 3.6 by ~3.0 – 4.6 kJ/mol. Structural analyses predicted that the side chains of introduced Tyr-34 and Tyr-43 become hydrogen donors for the hydrogen bond form...

  18. Ligand Access Channels in Cytochrome P450 Enzymes: A Review

    Directory of Open Access Journals (Sweden)

    Philippe Urban

    2018-05-01

    Full Text Available Quantitative structure-activity relationships may bring invaluable information on structural elements of both enzymes and substrates that, together, govern substrate specificity. Buried active sites in cytochrome P450 enzymes are connected to the solvent by a network of channels exiting at the distal surface of the protein. This review presents different in silico tools that were developed to uncover such channels in P450 crystal structures. It also lists some of the experimental evidence that actually suggest that these predicted channels might indeed play a critical role in modulating P450 functions. Amino acid residues at the entrance of the channels may participate to a first global ligand recognition of ligands by P450 enzymes before they reach the buried active site. Moreover, different P450 enzymes show different networks of predicted channels. The plasticity of P450 structures is also important to take into account when looking at how channels might play their role.

  19. Prognostic relevance of cytochrome C oxidase in primary glioblastoma multiforme.

    Directory of Open Access Journals (Sweden)

    Corinne E Griguer

    Full Text Available Patients with primary glioblastoma multiforme (GBM have one of the lowest overall survival rates among cancer patients, and reliable biomarkers are necessary to predict patient outcome. Cytochrome c oxidase (CcO promotes the switch from glycolytic to OXPHOS metabolism, and increased CcO activity in tumors has been associated with tumor progression after chemotherapy failure. Thus, we investigated the relationship between tumor CcO activity and the survival of patients diagnosed with primary GBM. A total of 84 patients with grade IV glioma were evaluated in this retrospective cohort study. Cumulative survival was calculated by the Kaplan-Meier method and analyzed by the log-rank test, and univariate and multivariate analyses were performed with the Cox regression model. Mitochondrial CcO activity was determined by spectrophotometrically measuring the oxidation of cytochrome c. High CcO activity was detected in a subset of glioma tumors (∼30%, and was an independent prognostic factor for shorter progression-free survival and overall survival [P = 0.0087 by the log-rank test, hazard ratio = 3.57 for progression-free survival; P<0.001 by the log-rank test, hazard ratio = 10.75 for overall survival]. The median survival time for patients with low tumor CcO activity was 14.3 months, compared with 6.3 months for patients with high tumor CcO activity. High CcO activity occurs in a significant subset of high-grade glioma patients and is an independent predictor of poor outcome. Thus, CcO activity may serve as a useful molecular marker for the categorization and targeted therapy of GBMs.

  20. Mode of Antifungal Drugs Interaction with Cytochrome P- 450

    Directory of Open Access Journals (Sweden)

    M- Mahmodian

    1991-07-01

    Full Text Available Computer was used to identify the interactions of substrates and antifungal drugs with the enzyme, Cytochrome P-450; and then Molplot.bas computer program was applied to get three dimensional figures of 5-hydroxy camphor.oxidation products of camphor analogues, and antifungal drugs.Cartesian characteristics of atoms building molecules, are taken from Buildz. for program, which can calculate X,Y,Z coordinates of atoms by Zmatrix data. The other program which can calculate X,Y,Z coordinates, using fractional characteristics, is the Coord, for program that, gives our cartesian characteristics of the atoms of molecule, then by using these data, we obtain three dimensional figures and distance between active atoms in compounds under consideration. Results show that distance between two oxygen atoms in 5-exo-hydroxy- camphor and the other compounds obtained from oxidation of camphor analogues, with the distance of two oxygen atoms in antifungal compounds under discussion are equal. Therefore, we can conclude that, the antifungal molecule also interacts with enzyme's active site, by its own sites, in a similar manner to the 5-hydroxy camphor molecule, which is:"n1. Nitrogen atom (N of Imidazole and Triazole ring in antifungal molecule with Iron atom in heam molecule belonging to Cytochrome P-450 enzyme, are coordinated."n2. The other atoms such as : 0,S or N in structure of the antifungal drug are coordinated with hydrogen atom of hydroxyl group belong ing to Tyr-96 in the structure of enzyme, forming hydrogen bonding.

  1. Dietary restriction ameliorates haematopoietic ageing independent of telomerase, whilst lack of telomerase and short telomeres exacerbates the ageing phenotype.

    Science.gov (United States)

    Al-Ajmi, Nouf; Saretzki, Gabriele; Miles, Colin; Spyridopoulos, Ioakim

    2014-10-01

    Ageing is associated with an overall decline in the functional capacity of tissues and stem cells, including haematopoietic stem and progenitor cells (HSPCs), as well as telomere dysfunction. Dietary restriction (DR) is a recognised anti-ageing intervention that extends lifespan and improves health in several organisms. To investigate the role of telomeres and telomerase in haematopoietic ageing, we compared the HSPC profile and clonogenic capacity of bone marrow cells from wild type with telomerase-deficient mice and the effect of DR on these parameters. Compared with young mice, aged wild type mice demonstrated a significant accumulation of HSPCs (1.3% vs 0.2%, P=0.002) and elevated numbers of granulocyte/macrophage colony forming units (CFU-GM, 26.4 vs 17.3, P=0.0037) consistent with myeloid "skewing" of haematopoiesis. DR was able to restrict the increase in HSPC number as well as the myeloid "skewing" in aged wild type mice. In order to analyse the influence of short telomeres on the ageing phenotype we examined mice lacking the RNA template for telomerase, TERC(-/-). Telomere shortening resulted in a similar bone marrow phenotype to that seen in aged mice, with significantly increased HSPC numbers and an increased formation of all myeloid colony types but at a younger age than wild type mice. However, an additional increase in erythroid colonies (BFU-E) was also evident. Mice lacking telomerase reverse transcriptase without shortened telomeres, TERT(-/-), also presented with augmented haematopoietic ageing which was ameliorated by DR, demonstrating that the effect of DR was not dependent on the presence of telomerase in HSPCs. We conclude that whilst shortened telomeres mimic some aspects of haematopoietic ageing, both shortened telomeres and the lack of telomerase produce specific phenotypes, some of which can be prevented by dietary restriction. Copyright © 2014 Elsevier Inc. All rights reserved.

  2. Resonance Raman study on photoreduction of cytochrome c oxidase: distinction of cytochromes a and a3 in the intermediate oxidation states.

    Science.gov (United States)

    Ogura, T; Yoshikawa, S; Kitagawa, T

    1985-12-17

    Occurrence of photoreduction of bovine cytochrome c oxidase was confirmed with the difference absorption spectra and oxygen consumption measurements for the enzyme irradiated with laser light at 406.7, 441.6, and 590 nm. The resonance Raman spectra were obtained under the same experimental conditions as those adopted for the measurements of oxygen consumption and difference absorption spectra. The photoreduction was more effective upon irradiation at shorter wavelengths and was irreversible under anaerobic conditions. However, upon aeration into the cell, the original oxidized form was restored. It was found that aerobic laser irradiation produces a photo steady state of the catalytic dioxygen reduction and that the Raman scattering from this photo steady state probes cytochrome a2+ and cytochrome a3(3)+ separately upon excitations at 441.6 and 406.7 nm, respectively. The enzyme was apparently protected from the photoreduction in the spinning cell with the spinning speed between 1 and 1500 rpm. These results were explained satisfactorily with the reported rate constant for the electron transfer from cytochrome a to cytochrome a3 (0.58 s-1) and a comparable photoreduction rate of cytochrome a. The anaerobic photoreduction did give Raman lines at 1666 and 214 cm-1, which are characteristic of the ferrous high-spin cytochrome a3(2)+, but they were absent under aerobic photoreduction. The formyl CH = O stretching mode of the a3 heme was observed at 1671 cm-1 for a2+a3(2)+CO but at 1664 cm-1 for a2+a3(2)+CN-, indicating that the CH = O stretching frequency reflects the pi back-donation to the axial ligand similar to the oxidation state marker line (v4).

  3. Immunohistochemical detection of cytochrome P450 isoenzymes in cultured human epidermal cells.

    Science.gov (United States)

    Van Pelt, F N; Meierink, Y J; Blaauboer, B J; Weterings, P J

    1990-12-01

    We used specific monoclonal antibodies (MAb) to human cytochrome P450 isoenzymes to determine the presence of these proteins in human epidermal cells. Two MAb (P450-5 and P450-8) recognize major forms of hepatic cytochrome P450 involved in biotransformation of xenobiotics. A third MAb, to cytochrome P450-9, is not fully characterized. The proteins were determined by the indirect immunoperoxidase technique after fixation with methanol and acetone. Biopsy materials for cultured keratinocytes, i.e., foreskin and hair follicles, contained the two major forms of cytochrome P450. In cultured keratinocytes derived from hair follicles the proteins were undetectable, whereas the keratinocytes derived from foreskin continued to express the two major forms of hepatic cytochrome P450. Cultured human fibroblasts and a human keratinocyte cell line (SVK14) showed staining similar to that of the foreskin keratinocytes. Cytochrome P450-9 was detectable only in human hepatocytes. The results indicate that, under the culture conditions applied, cultured human foreskin cells and the cell line SVK14 continue to express specific cytochrome P450 isoenzymes in culture, in contrast to hair follicle keratinocytes.

  4. Lack of efficacy of ergocalciferol repletion

    Directory of Open Access Journals (Sweden)

    Thomas Wasser

    2012-04-01

    Full Text Available Introduction: Vitamin D has become an area of intensive scrutiny, both in medical and lay literature. However, there are limited data to suggest proper repletion regimens for those patients who have hypovitaminosis D. Consequently, various methods are used in clinical practice. The aim of this study was to assess the efficacy of various treatment strategies for hypovitaminosis D in an ambulatory internal medicine practice. Methods: A retrospective chart review between October 2005 and June 2010 of a suburban internal medicine practice was performed via query of the electronic medical record (Centricity, General Electric Healthcare, UK. Patients with a 25-hydroxyvitamin D concentration less than 32 mg/dl were identified and treated. Treatment success was defined as 25-hydroxyvitamin D concentrations greater than 32 mg/dl. Statistical analysis to assess changes in vitamin D level controlling for season, comorbidities, and demographics were used. Results: A total of 607 treatment episodes were identified, with 395 excluded due to lack of follow-up vitamin D level within 16 weeks, no treatment documented, topical treatment, doxercalciferol treatment, or non-compliance. Of the remaining patients, there were 212 treatment instances on 178 patients. Ergocalciferol 50,000 international units (IU was used most frequently (71.4% of the time.. A higher initial vitamin D level was positively associated with treatment success (adjusted odds ratio = 1.11, p=0.002. Increased doses of ergocalciferol increased the likelihood of treatment success (p=0.0011. Seasonal variation was related to posttreatment 25-hydroxyvitamin D concentration as was body mass index (BMI (p=0.003 and p=0.044. Conclusion: Pretreatment levels of 25-hydroxyvitamin D, BMI, season, and vitamin D dose are predictors of successful hypovitaminosis D treatment. Our data suggest that patients with initial 25-hydroxyvitamin D concentrations of <20 should be treated with a higher total dose of

  5. Tributyltin potentiates 3,3{prime},4,4{prime},5-pentachlorobiphenyl-induced cytochrome P-4501A-related activity

    Energy Technology Data Exchange (ETDEWEB)

    DeLong, G.T.; Rice, C.D. [Mississippi State Univ., MS (United States)

    1997-10-01

    Induction of cytochrome P-4501A protein and induction of related enzyme activity are hallmark physiological responses following exposure to planar halogenated aromatic hydrocarbons (HAHs) such as 3,3{prime},4,4{prime},5-pentachlorobiphenyl (PCB 126; PeCB). Environments contaminated by HAHs are often contaminated by mixtures of anthropogenic contaminants, including organometallic compounds. Both HAHs and organometallics easily bioconcentrate in aquatic food chains that may be linked to humans through seafood consumption. Tributyltin (TBT), a marine biocide, has been detected in many aquatic environments. Exposure to TBT, as well as several PCBs, has been associated with immunotoxicity, neurotoxicity, and endocrine disruption. Recently TBT has been shown to inhibit cytochrome P-4501A activity in vitro. Female mice were exposed to 0.07, 0.1, and 1.0 mg/kg PeCB, TBT or both. P-4501A levels and BaP-OHase activity were significantly elevated in mice exposed to PeCB alone. This effect was enhanced by coexposure to low levels of TBT; PeCB-induced P-4501A-related activity was potentiated at the low range of each. The highest dose of TBT, however, inhibited these activities when given in combination with PeCB. Thymic atrophy was evident only in mice exposed daily to 0.1 and 1.0 mg/kg PeCB alone, or to a combination of the lowest and highest dose of PeCB and TBT, respectively. Because environmental levels of. TBT are not expected to be as high as the highest level used in our toxicological studies, we conclude that environmental exposure to TBT may potentiate, rather than inhibit, the activity of environmental levels of HAHs that are associated with P-4501A induction. 31 refs., 8 figs.

  6. In situ Raman study of redox state changes of mitochondrial cytochromes in a perfused rat heart

    DEFF Research Database (Denmark)

    Brazhe, Nadezda; Treiman, Marek; Faricelli, Barbara

    2013-01-01

    We developed a Raman spectroscopy-based approach for simultaneous study of redox changes in c-and b-type cytochromes and for a semiquantitative estimation of the amount of oxygenated myoglobin in a perfused rat heart. Excitation at 532 nm was used to obtain Raman scattering of the myocardial...... surface of the isolated heart at normal and hypoxic conditions. Raman spectra of the heart under normal pO2 demonstrate unique peaks attributable to reduced c-and b-type cytochromes and oxymyoglobin (oMb). The cytochrome peaks decreased in intensity upon FCCP treatment, as predicted from uncoupling...

  7. Removal of Bound Triton X-100 from Purified Bovine Heart Cytochrome bc1

    OpenAIRE

    Varhač, Rastislav; Robinson, Neal C.; Musatov, Andrej

    2009-01-01

    Cytochrome bc1 isolated from Triton X-100 solubilized mitochondrial membranes contains up to 120 nmol of Triton X-100 bound per nmol of the enzyme. Purified cytochrome bc1 is fully active; however, protein bound Triton X-100 significantly interferes with structural studies of the enzyme. Removal of Triton X-100 bound to bovine cytochrome bc1 was accomplished by incubation with Bio-Beads SM-2 in presence of sodium cholate. Sodium cholate is critical since it does not interfere with the adsorpt...

  8. The Cytochrome bd Oxidase of Porphyromonas gingivalis Contributes to Oxidative Stress Resistance and Dioxygen Tolerance.

    Directory of Open Access Journals (Sweden)

    Julia Leclerc

    Full Text Available Porphyromonas gingivalis is an etiologic agent of periodontal disease in humans. The disease is associated with the formation of a mixed oral biofilm which is exposed to oxygen and environmental stress, such as oxidative stress. To investigate possible roles for cytochrome bd oxidase in the growth and persistence of this anaerobic bacterium inside the oral biofilm, mutant strains deficient in cytochrome bd oxidase activity were characterized. This study demonstrated that the cytochrome bd oxidase of Porphyromonas gingivalis, encoded by cydAB, was able to catalyse O2 consumption and was involved in peroxide and superoxide resistance, and dioxygen tolerance.

  9. Magnetic circular dichroism studies on microsomal aryl hydrocarbon hydroxylase: comparison with cytochrome b/sub 5/ and cytochrome P-450/sub cam/

    Energy Technology Data Exchange (ETDEWEB)

    Vickery, L; Salmon, A; Sauer, K

    1975-01-01

    Magnetic circular dichroism spectra are reported for the visible and near ultraviolet spectral regions of liver microsomes from dimethylbenzanthracene-treated rats. The sequential addition of NADH, dithionite, and carbon monoxide enables us to determine contributions to the magnetic circular dichroism by cytochromes b/sub 5/ and P-450, which dominate the spectra. The magnetic circular dichroism of the microsomal preparation is compared with that of purified oxidized and reduced cytochrome b/sub 5/ from pig liver and with the camphor-complexed and camphor-free oxidized, reduced, and reduced carbonmonoxy cytochrome P-450/sub cam/ from Pseudomonas putida. The magnetic circular dichroism spectra of the membrane bound cytochrome b/sub 5/ are similar to those of the purified protein, indicating that little or no alteration in the environment of the heme occurs during the isolation procedure. The soluble bacterial cytochrome P-450/sub cam/ also appears to be a suitable model for microsomal P-450, although differences in the magnetic circular dichroism intensity are observed for the two enzymes. No effect of dimethylbenzanthracene on the magnetic circular dichroism spectra of induced compared to control rat microsomes could be observed.

  10. Does Skeletal Muscle Mass Influence Breast Cancer? Evaluating Mammary Tumorigenesis and Progression Genetically Hyper-Muscular Mice

    National Research Council Canada - National Science Library

    Zimmers, Teresa

    2006-01-01

    .... Mice lacking the skeletal muscle-specific muscle growth inhibitor myostatin and mice expressing a dominant negative form of the myostatin receptor, Activin Receptor Type IIB, display heightened muscle mass...

  11. Sulfite oxidase activity of cytochrome c: Role of hydrogen peroxide

    Directory of Open Access Journals (Sweden)

    Murugesan Velayutham

    2016-03-01

    Full Text Available In humans, sulfite is generated endogenously by the metabolism of sulfur containing amino acids such as methionine and cysteine. Sulfite is also formed from exposure to sulfur dioxide, one of the major environmental pollutants. Sulfite is used as an antioxidant and preservative in dried fruits, vegetables, and beverages such as wine. Sulfite is also used as a stabilizer in many drugs. Sulfite toxicity has been associated with allergic reactions characterized by sulfite sensitivity, asthma, and anaphylactic shock. Sulfite is also toxic to neurons and cardiovascular cells. Recent studies suggest that the cytotoxicity of sulfite is mediated by free radicals; however, molecular mechanisms involved in sulfite toxicity are not fully understood. Cytochrome c (cyt c is known to participate in mitochondrial respiration and has antioxidant and peroxidase activities. Studies were performed to understand the related mechanism of oxidation of sulfite and radical generation by ferric cytochrome c (Fe3+cyt c in the absence and presence of H2O2. Electron paramagnetic resonance (EPR spin trapping studies using 5,5-dimethyl-1-pyrroline-N-oxide (DMPO were performed with sulfite, Fe3+cyt c, and H2O2. An EPR spectrum corresponding to the sulfite radical adducts of DMPO (DMPO-SO3- was obtained. The amount of DMPO-SO3- formed from the oxidation of sulfite by the Fe3+cyt c increased with sulfite concentration. In addition, the amount of DMPO-SO3- formed by the peroxidase activity of Fe3+cyt c also increased with sulfite and H2O2 concentration. From these results, we propose a mechanism in which the Fe3+cyt c and its peroxidase activity oxidizes sulfite to sulfite radical. Our results suggest that Fe3+cyt c could have a novel role in the deleterious effects of sulfite in biological systems due to increased production of sulfite radical. It also shows that the increased production of sulfite radical may be responsible for neurotoxicity and some of the injuries which

  12. Lack of the purinergic receptor P2X7 results in resistance to contact hypersensitivity

    Science.gov (United States)

    Weber, Felix C.; Esser, Philipp R.; Müller, Tobias; Ganesan, Jayanthi; Pellegatti, Patrizia; Simon, Markus M.; Zeiser, Robert; Idzko, Marco; Jakob, Thilo

    2010-01-01

    Sensitization to contact allergens requires activation of the innate immune system by endogenous danger signals. However, the mechanisms through which contact allergens activate innate signaling pathways are incompletely understood. In this study, we demonstrate that mice lacking the adenosine triphosphate (ATP) receptor P2X7 are resistant to contact hypersensitivity (CHS). P2X7-deficient dendritic cells fail to induce sensitization to contact allergens and do not release IL-1β in response to lipopolysaccharide (LPS) and ATP. These defects are restored by pretreatment with LPS and alum in an NLRP3- and ASC-dependent manner. Whereas pretreatment of wild-type mice with P2X7 antagonists, the ATP-degrading enzyme apyrase or IL-1 receptor antagonist, prevents CHS, IL-1β injection restores CHS in P2X7-deficient mice. Thus, P2X7 is a crucial receptor for extracellular ATP released in skin in response to contact allergens. The lack of P2X7 triggering prevents IL-1β release, which is an essential step in the sensitization process. Interference with P2X7 signaling may be a promising strategy for the prevention of allergic contact dermatitis. PMID:21059855

  13. Conjugation of cytochrome c with hydrogen titanate nanotubes: novel conformational state with implications for apoptosis

    Energy Technology Data Exchange (ETDEWEB)

    Ray, Moumita; Mazumdar, Shyamalava [Department of Chemical Sciences, Tata Institute of Fundamental Research, Homi Bhabha Road, Mumbai 400005 (India); Chatterjee, Sriparna; Das, Tanmay; Bhattacharyya, Somnath; Ayyub, Pushan, E-mail: somnath@tifr.res.in, E-mail: pushan@tifr.res.in, E-mail: shyamal@tifr.res.in [Department of Condensed Matter Physics and Materials Science, Tata Institute of Fundamental Research, Homi Bhabha Road, Mumbai 400005 (India)

    2011-10-14

    We show that hydrogen titanate (H{sub 2}Ti{sub 3}O{sub 7}) nanotubes form strongly associated reversible nano-bio-conjugates with the vital respiratory protein, cytochrome c. Resonance Raman spectroscopy along with direct electrochemical studies indicate that in this nano-bio-conjugate, cytochrome c exists in an equilibrium of two conformational states with distinctly different formal redox potentials and coordination geometries of the heme center. The nanotube-conjugated cytochrome c also showed enhanced peroxidase activity similar to the membrane-bound protein that is believed to be an apoptosis initiator. This suggests that such a nanotube-cytochrome c conjugate may be a good candidate for cancer therapy applications.

  14. Prognostic Value of Cytochrome C and Cytokines in Acute Viral Encephalopathy

    Directory of Open Access Journals (Sweden)

    J Gordon Millichap

    2006-06-01

    Full Text Available Serum cytochrome c and cytokines were evaluated as prognostic predictors in 29 children (ages 9 mos to 9 yrs 11 mos with viral acute encephalopathies and multiple organ failure at Fukushima Medical University School of Medicine, Japan.

  15. Evidence that Na+-pumping occurs through the D-channel in Vitreoscilla cytochrome bo

    International Nuclear Information System (INIS)

    Kim, Seong K.; Stark, Benjamin C.; Webster, Dale A.

    2005-01-01

    The operon (cyo) encoding the Na + -pumping respiratory terminal oxidase (cytochrome bo) of the bacterium Vitreoscilla was transformed into Escherichia coli GV100, a deletion mutant of cytochrome bo. This was done for the wild type operon and five mutants in three conserved Cyo subunit I amino acids known to be crucial for H + transport in the E. coli enzyme, one near the nuclear center, one in the K-channel, and one in the D-channel. CO-binding, NADH and ubiquinol oxidase, and Na + -pumping activities were all substantially inhibited by each mutation. The wild type Vitreoscilla cytochrome bo can pump Na + against a concentration gradient, resulting in a transmembrane concentration differential of 2-3 orders of magnitude. It is proposed that Vitreoscilla cytochrome bo pumps four Na + through the D-channel to the exterior and transports four H + through the K-channel for the reduction of each O 2

  16. A mitochondrial cytochrome b mutation causing severe respiratory chain enzyme deficiency in humans and yeast.

    NARCIS (Netherlands)

    Blakely, E.L.; Mitchell, A.L.; Fisher, N.; Meunier, B.; Nijtmans, L.G.J.; Schaefer, A.M.; Jackson, M.J.; Turnbull, D.M.; Taylor, R.W.

    2005-01-01

    Whereas the majority of disease-related mitochondrial DNA mutations exhibit significant biochemical and clinical heterogeneity, mutations within the mitochondrially encoded human cytochrome b gene (MTCYB) are almost exclusively associated with isolated complex III deficiency in muscle and a clinical

  17. P450 reductase and cytochrome b5 interactions with cytochrome P450: Effects on house fly CYP6A1 catalysis

    OpenAIRE

    Murataliev, Marat B.; Guzov, Victor M.; Walker, F. Ann; Feyereisen, René

    2008-01-01

    The interactions of protein components of the xenobiotic-metabolizing cytochrome P450 system, CYP6A1, P450 reductase, and cytochrome b5 from the house fly (Musca domestica) have been characterized. CYP6A1 activity is determined by the concentration of the CYP6A1-P450 reductase complex, regardless of which protein is present in excess. Both holo- and apo-b5 stimulated CYP6A1 heptachlor epoxidase and steroid hydroxylase activities and influenced the regioselectivity of testosterone hydroxylatio...

  18. [Immunomodulators with an 8-azasteroid structure as inducers of liver cytochrome P-450].

    Science.gov (United States)

    Kuz'mitskiĭ, B B; Dad'kov, I G; Mashkovich, A E; Stoma, O V; Slepneva, L M

    1990-01-01

    Two structural analogues of D-homo-8-azasteroids, both an immunostimulant and an immunodepressant, are inductors of the liver cytochrome P-450 in animals. This capability was shown by means of both a decrease of the hexenal sleep duration in the pharmacological test and an increase of the quantity of cytochrome P-450 and the rate of N-demethylation of aminopyrine in the biochemical assays.

  19. Evolution of NADPH-cytochrome P450 oxidoreductases (POR) in Apiales - POR 1 is missing

    DEFF Research Database (Denmark)

    Andersen, Trine Bundgaard; Hansen, Niels Bjørn; Laursen, Tomas

    2016-01-01

    The NADPH-dependent cytochrome P450 oxidoreductase (POR) is the obligate electron donor to eukaryotic microsomal cytochromes P450 enzymes. The number of PORs within plant species is limited to one to four isoforms, with the most common being two PORs per plant. These enzymes provide electrons to ...... (available from the SRA at NCBI). All three genes were shown to be functional upon reconstitution into nanodiscs, confirming that none of the isoforms are pseudogenes....

  20. Utilizing Chemical Genomics to Identify Cytochrome b as a Novel Drug Target for Chagas Disease.

    Directory of Open Access Journals (Sweden)

    Shilpi Khare

    2015-07-01

    Full Text Available Unbiased phenotypic screens enable identification of small molecules that inhibit pathogen growth by unanticipated mechanisms. These small molecules can be used as starting points for drug discovery programs that target such mechanisms. A major challenge of the approach is the identification of the cellular targets. Here we report GNF7686, a small molecule inhibitor of Trypanosoma cruzi, the causative agent of Chagas disease, and identification of cytochrome b as its target. Following discovery of GNF7686 in a parasite growth inhibition high throughput screen, we were able to evolve a GNF7686-resistant culture of T. cruzi epimastigotes. Clones from this culture bore a mutation coding for a substitution of leucine by phenylalanine at amino acid position 197 in cytochrome b. Cytochrome b is a component of complex III (cytochrome bc1 in the mitochondrial electron transport chain and catalyzes the transfer of electrons from ubiquinol to cytochrome c by a mechanism that utilizes two distinct catalytic sites, QN and QP. The L197F mutation is located in the QN site and confers resistance to GNF7686 in both parasite cell growth and biochemical cytochrome b assays. Additionally, the mutant cytochrome b confers resistance to antimycin A, another QN site inhibitor, but not to strobilurin or myxothiazol, which target the QP site. GNF7686 represents a promising starting point for Chagas disease drug discovery as it potently inhibits growth of intracellular T. cruzi amastigotes with a half maximal effective concentration (EC50 of 0.15 µM, and is highly specific for T. cruzi cytochrome b. No effect on the mammalian respiratory chain or mammalian cell proliferation was observed with up to 25 µM of GNF7686. Our approach, which combines T. cruzi chemical genetics with biochemical target validation, can be broadly applied to the discovery of additional novel drug targets and drug leads for Chagas disease.

  1. Glaucoma and Cytochrome P4501B1 Gene Mutations

    Directory of Open Access Journals (Sweden)

    Mukesh Tanwar

    2010-01-01

    Full Text Available Developmental anomalies of the ocular anterior chamber angle may lead to an incomplete development of the structures that form the conventional aqueous outflow pathway. Thus, disorders that present with such dysfunction tend to be associated with glaucoma. Among them, Axenfeld-Rieger (ARS malformation is a rare clinical entity with an estimated prevalence of one in every 200,000 individuals. The changes in eye morphogenesis in ARS are highly penetrant and are associated with 50% risk of development of glaucoma. Mutations in the cytochrome P4501B1 (CYP1B1 gene have been reported to be associated with primary congenital glaucoma and other forms of glaucoma and mutations in pituitary homeobox 2 (PITX2 gene have been identified in ARS in various studies. This case was negative for PITX2 mutations and compound heterozygote for CYP1B1 mutations. Clinical manifestations of this patient include bilateral elevated intraocular pressure (>40 mmHg with increased corneal diameter (>14 mm and corneal opacity. Patient also had iridocorneal adhesions, anteriorly displaced Schwalbe line, anterior insertion of iris, broad nasal bridge and protruding umbilicus. This is the first study from north India reporting CYP1B1 mutations in Axenfeld-Rieger syndrome with bilateral buphthalmos and early onset glaucoma. Result of this study supports the role of CYP1B1 as a causative gene in ASD disorders and its role in oculogenesis.

  2. Enhanced mitochondrial degradation of yeast cytochrome c with amphipathic structures.

    Science.gov (United States)

    Chen, Xi; Moerschell, Richard P; Pearce, David A; Ramanan, Durga D; Sherman, Fred

    2005-02-01

    The dispensable N-terminus of iso-1-cytochrome c (iso-1) in the yeast Saccharomyces cerevisiae was replaced by 11 different amphipathic structures. Rapid degradation of the corresponding iso-1 occurred, with the degree of degradation increasing with the amphipathic moments; and this amphipathic-dependent degradation was designated ADD. ADD occurred with the holo-forms in the mitochondria but not as the apo-forms in the cytosol. The extreme mutant type degraded with a half-life of approximately 12 min, whereas the normal iso-1 was stable over hours. ADD was influenced by the rho+/rho- state and by numerous chromosomal genes. Most importantly, ADD appeared to be specifically suppressed to various extents by deletions of any of the YME1, AFG3, or RCA1 genes encoding membrane-associated mitochondrial proteases, probably because the amphipathic structures caused a stronger association with the mitochondrial inner membrane and its associated proteases. The use of ADD assisted in the differentiation of substrates of different mitochondrial degradation pathways.

  3. Clinical Pharmacogenetics of Cytochrome P450-Associated Drugs in Children

    Directory of Open Access Journals (Sweden)

    Ida Aka

    2017-11-01

    Full Text Available Cytochrome P450 (CYP enzymes are commonly involved in drug metabolism, and genetic variation in the genes encoding CYPs are associated with variable drug response. While genotype-guided therapy has been clinically implemented in adults, these associations are less well established for pediatric patients. In order to understand the frequency of pediatric exposures to drugs with known CYP interactions, we compiled all actionable drug–CYP interactions with a high level of evidence using Clinical Pharmacogenomic Implementation Consortium (CPIC data and surveyed 10 years of electronic health records (EHR data for the number of children exposed to CYP-associated drugs. Subsequently, we performed a focused literature review for drugs commonly used in pediatrics, defined as more than 5000 pediatric patients exposed in the decade-long EHR cohort. There were 48 drug–CYP interactions with a high level of evidence in the CPIC database. Of those, only 10 drugs were commonly used in children (ondansetron, oxycodone, codeine, omeprazole, lansoprazole, sertraline, amitriptyline, citalopram, escitalopram, and risperidone. For these drugs, reports of the drug–CYP interaction in cohorts including children were sparse. There are adequate data for implementation of genotype-guided therapy for children for three of the 10 commonly used drugs (codeine, omeprazole and lansoprazole. For the majority of commonly used drugs with known CYP interactions, more data are required to support pharmacogenomic implementation in children.

  4. Becoming a Peroxidase: Cardiolipin-Induced Unfolding of Cytochrome c

    Science.gov (United States)

    Muenzner, Julia; Toffey, Jason R.; Hong, Yuning; Pletneva, Ekaterina V.

    2014-01-01

    Interactions of cytochrome c (cyt c) with a unique mitochondrial glycerophospholipid cardiolipin (CL) are relevant for the protein’s function in oxidative phosphorylation and apoptosis. Binding to CL-containing membranes promotes cyt c unfolding and dramatically enhances the protein’s peroxidase activity, which is critical in early stages of apoptosis. We have employed a collection of seven dansyl variants of horse heart cyt c to probe the sequence of steps in this functional transformation. Kinetic measurements have unraveled four distinct processes during CL-induced cyt c unfolding: rapid protein binding to CL liposomes; rearrangements of protein substructures with small unfolding energies; partial insertion of the protein into the lipid bilayer; and extensive protein restructuring leading to “open” extended structures. While early rearrangements depend on a hierarchy of foldons in the native structure, the later process of large-scale unfolding is influenced by protein interactions with the membrane surface. The opening of the cyt c structure exposes the heme group, which enhances the protein’s peroxidase activity and also frees the C-terminal helix to aid in the translocation of the protein through CL membranes. PMID:23713573

  5. Force modulation and electrochemical gating of conductance in a cytochrome

    Science.gov (United States)

    Davis, Jason J.; Peters, Ben; Xi, Wang

    2008-09-01

    Scanning probe methods have been used to measure the effect of electrochemical potential and applied force on the tunnelling conductance of the redox metalloprotein yeast iso-1-cytochrome c (YCC) at a molecular level. The interaction of a proximal probe with any sample under test will, at this scale, be inherently perturbative. This is demonstrated with conductive probe atomic force microscopy (CP-AFM) current-voltage spectroscopy in which YCC, chemically adsorbed onto pristine Au(111) via its surface cysteine residue, is observed to become increasingly compressed as applied load is increased, with concomitant decrease in junction resistance. Electrical contact at minimal perturbation, where probe-molecule coupling is comparable to that in scanning tunnelling microscopy, brings with it the observation of negative differential resistance, assigned to redox-assisted probe-substrate tunnelling. The role of the redox centre in conductance is also resolved in electrochemical scanning tunnelling microscopy assays where molecular conductance is electrochemically gateable through more than an order of magnitude.

  6. Regulation of the cytochrome P450 2A genes

    International Nuclear Information System (INIS)

    Su Ting; Ding Xinxin

    2004-01-01

    Cytochrome P450 monooxygenases of the CYP2A subfamily play important roles in xenobiotic disposition in the liver and in metabolic activation in extrahepatic tissues. Many of the CYP2A transcripts and enzymes are inducible by xenobiotic compounds, and the expression of at least some of the CYP2A genes is influenced by physiological status, such as circadian rhythm, and pathological conditions, such as inflammation, microbial infection, and tumorigenesis. Variability in the expression of the CYP2A genes, which differs by species, animal strain, gender, and organ, may alter the risks of chemical toxicity for numerous compounds that are CYP2A substrates. The mechanistic bases of these variabilities are generally not well understood. However, recent studies have yielded interesting findings in several areas, such as the role of nuclear factor 1 in the tissue-selective expression of CYP2A genes in the olfactory mucosa (OM); the roles of constitutive androstane receptor, pregnane X receptor (PXR), and possibly, peroxisome proliferator-activated receptors in transcriptional regulation of the Cyp2a5 gene; and the involvement of heterogeneous nuclear ribonucleoprotein A1 in pyrazole-induced stabilization of CYP2A5 mRNA. The aims of this minireview are to summarize current knowledge of the regulation of the CYP2A genes in rodents and humans, and to stimulate further mechanistic studies that will ultimately improve our ability to determine, and to understand, these variabilities in humans

  7. Expression of cytochrome P450 regulators in cynomolgus macaque.

    Science.gov (United States)

    Uno, Yasuhiro; Yamazaki, Hiroshi

    2017-09-11

    1. Cytochrome P450 (P450) regulators including nuclear receptors and transcription factors have not been fully investigated in cynomolgus macaques, an important species used in drug metabolism studies. In this study, we analyzed 17 P450 regulators by sequence and phylogenetic analysis, and tissue expression. 2. Gene and genome structures of 17 P450 regulators were similar to the human orthologs, and the deduced amino acid sequences showed high sequence identities (92-95%) and more closely clustered in a phylogenetic tree, with the human orthologs. 3. Many of the P450 regulator mRNAs were preferentially expressed in the liver, kidney, and/or jejunum. Among the P450 regulator mRNAs, PXR was most abundant in the liver and jejunum, and HNF4α in the kidney. In the liver, the expression of most P450 regulator mRNAs did not show significant differential expression (>2.5-fold) between cynomolgus macaques bred in Cambodia, China, and Indonesia, or rhesus macaques. 4. By correlation analysis, most of the P450 regulators were significantly (p < 0.05) correlated to other P450 regulators, and many of them were also significantly (p < 0.05) correlated with P450s. 5. These results suggest that 17 P450 regulators of cynomolgus macaques had similar molecular characteristics to the human orthologs.

  8. Interaction of rocuronium with human liver cytochromes P450.

    Science.gov (United States)

    Anzenbacherova, Eva; Spicakova, Alena; Jourova, Lenka; Ulrichova, Jitka; Adamus, Milan; Bachleda, Petr; Anzenbacher, Pavel

    2015-02-01

    Rocuronium is a neuromuscular blocking agent acting as a competitive antagonist of acetylcholine. Results of an inhibition of eight individual liver microsomal cytochromes P450 (CYP) are presented. As the patients are routinely premedicated with diazepam, possible interaction of diazepam with rocuronium has been also studied. Results indicated that rocuronium interacts with human liver microsomal CYPs by binding to the substrate site. Next, concentration dependent inhibition of liver microsomal CYP3A4 down to 42% (at rocuronium concentration 189 μM) was found. This effect has been confirmed with two CYP3A4 substrates, testosterone (formation of 6β-hydroxytestosterone) and diazepam (temazepam formation). CYP2C9 and CYP2C19 activities were inhibited down to 75-80% (at the same rocuronium concentration). Activities of other microsomal CYPs have not been inhibited by rocuronium. To prove the possibility of rocuronium interaction with other drugs (diazepam), the effect of rocuronium on formation of main diazepam metabolites, temazepam (by CYP3A4) and desmethyldiazepam, (also known as nordiazepam; formed by CYP2C19) in primary culture of human hepatocytes has been examined. Rocuronium has caused inhibition of both reactions by 20 and 15%, respectively. The results open a possibility that interactions of rocuronium with drugs metabolized by CYP3A4 (and possibly also CYP2C19) may be observed. Copyright © 2014 Japanese Pharmacological Society. Production and hosting by Elsevier B.V. All rights reserved.

  9. Direct observation of vibrational energy flow in cytochrome c.

    Science.gov (United States)

    Fujii, Naoki; Mizuno, Misao; Mizutani, Yasuhisa

    2011-11-10

    Vibrational energy flow in ferric cytochrome c has been examined by picosecond time-resolved anti-Stokes ultraviolet resonance Raman (UVRR) measurements. By taking advantage of the extremely short nonradiative excited state lifetime of heme in the protein (energy of 20000-25000 cm(-1) was optically deposited selectively at the heme site. Subsequent energy relaxation in the protein moiety was investigated by monitoring the anti-Stokes UVRR intensities of the Trp59 residue, which is a single tryptophan residue involved in the protein that is located close to the heme group. It was found from temporal changes of the anti-Stokes UVRR intensities that the energy flow from the heme to Trp59 and the energy release from Trp59 took place with the time constants of 1-3 and ~8 ps, respectively. These data are consistent with the time constants for the vibrational relaxation of the heme and heating of water reported for hemeproteins. The kinetics of the energy flow were not affected by the amount of excess energy deposited at the heme group. These results demonstrate that the present technique is a powerful tool for studying the vibrational energy flow in proteins.

  10. Polycyclic aromatic hydrocarbons and cytochrome P450 in HIV pathogenesis

    Science.gov (United States)

    Rao, P. S. S.; Kumar, Santosh

    2015-01-01

    High prevalence of cigarette smoking in HIV patients is associated with increased HIV pathogenesis and disease progression. While the effect of smoking on the occurrence of lung cancer has been studied extensively, the association between smoking and HIV pathogenesis is poorly studied. We have recently shown the possible role of cytochrome P450 (CYP) in smoking/nicotine-mediated viral replication. In this review, we focus on the potential role of CYP pathway in polycyclic aromatic hydrocarbons (PAH), important constituents of cigarette smoke, mediated HIV pathogenesis. More specifically, we will discuss the role of CYP1A1 and CYP1B1, which are the major PAH-activating CYP enzymes. Our results have shown that treatment with cigarette smoke condensate (CSC) increases viral replication in HIV-infected macrophages. CSC contains PAH, which are known to be activated by CYP1A1 and CYP1B1 into procarcinogens/toxic metabolites. The expression of these CYPs is regulated by aryl hydrocarbon receptors (AHR), the cellular target of PAH, and an important player in various diseases including cancer. We propose that PAH/AHR-mediated CYP pathway is a novel target to develop new interventions for HIV positive smokers. PMID:26082767

  11. Cytochromes P450: History, Classes, Catalytic Mechanism, and Industrial Application.

    Science.gov (United States)

    Cook, D J; Finnigan, J D; Cook, K; Black, G W; Charnock, S J

    Cytochromes P450, a family of heme-containing monooxygenases that catalyze a diverse range of oxidative reactions, are so-called due to their maximum absorbance at 450nm, ie, "Pigment-450nm," when bound to carbon monoxide. They have appeal both academically and commercially due to their high degree of regio- and stereoselectivity, for example, in the area of active pharmaceutical ingredient synthesis. Despite this potential, they often exhibit poor stability, low turnover numbers and typically require electron transport protein(s) for catalysis. P450 systems exist in a variety of functional domain architectures, organized into 10 classes. P450s are also divided into families, each of which is based solely on amino acid sequence homology. Their catalytic mechanism employs a very complex, multistep catalytic cycle involving a range of transient intermediates. Mutagenesis is a powerful tool for the development of improved biocatalysts and has been used extensively with the archetypal Class VIII P450, BM3, from Bacillus megaterium, but with the increasing scale of genomic sequencing, a huge resource is now available for the discovery of novel P450s. © 2016 Elsevier Inc. All rights reserved.

  12. Differences in renal metabolism of insulin and cytochrome c

    International Nuclear Information System (INIS)

    Herrman, J.; Simmons, R.E.; Frank, B.H.; Rabkin, R.

    1988-01-01

    Kidneys degrade small proteins such as cytochrome c (CYT c) by the classic lysosomal pathway. However, because alternate routes for the transport and degradation of protein hormones have been identified in other tissues, the authors set out to determine whether extralysosomal sites might participate in the renal degradation of insulin. First, they compared the effect of the lysosomal inhibitor NH 4 Cl on insulin and CYT c degradation by isolated perfused rat kidneys. After kidneys were loaded with radiolabeled proteins to allow for absorption and transport to lysosomes, degradation was measured in the presence or absence of inhibitors. Next they followed the subcellular distribution of 125 I-labeled insulin in kidneys exposed to 125 I-labeled insulin in vivo or when isolated and perfused. Under both circumstances the distribution of insulin on a linear sucrose gradient differed from that of the lysosomal enzyme N-acetyl-β-glucosaminidase. In contrast, [ 14 CH 3 ]CYT c, injected in vivo, distributed over a density similar to the lysosomal marker. Thus important differences exist between the renal metabolism of CYT c, which proceeds in lysosomes, and the renal metabolism of insulin. These include rate of degradation, sensitivity to NH 4 Cl, and subcellular sites of localization. Accordingly, they suggest that insulin degradation may occur, at least in part, in a different compartment from the classic lysosomal site of protein degradation

  13. MOLECULAR DYNAMICS STUDY OF CYTOCHROME C – LIPID COMPLEXES

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    V. Trusova

    2017-10-01

    Full Text Available The interactions between a mitochondrial hemoprotein cytochrome c (cyt c and the model lipid membranes composed of zwitterionic lipid phosphatidylcholine (PC and anionic lipids phosphatidylglycerol (PG, phosphatidylserine (PS or cardiolipin (CL were studied using the method of molecular dynamics. It was found that cyt c structure remains virtually unchanged in the protein complexes with PC/PG or PC/PS bilayers. In turn, protein binding to PC/CL bilayer is followed by the rise in cyt c radius of gyration and root-mean-square fluctuations. The magnitude of these changes was demonstrated to increase with the anionic lipid content. The revealed effect was interpreted in terms of the partial unfolding of polypeptide chain in the region Ala15-Leu32, widening of the heme crevice and enhancement of the conformational fluctuations in the region Pro76-Asp93 upon increasing the CL molar fraction from 5 to 25%. The results obtained seem to be of utmost importance in the context of amyloidogenic propensity of cyt c.

  14. Taxonomic relationships among Phenacomys voles as inferred by cytochrome b

    Science.gov (United States)

    Bellinger, M.R.; Haig, S.M.; Forsman, E.D.; Mullins, T.D.

    2005-01-01

    Taxonomic relationships among red tree voles (Phenacomys longicaudus longicaudus, P. l. silvicola), the Sonoma tree vole (P. pomo), the white-footed vole (P. albipes), and the heather vole (P. intermedius) were examined using 664 base pairs of the mitochondrial cytochrome b gene. Results indicate specific differences among red tree voles, Sonoma tree voles, white-footed voles, and heather voles, but no clear difference between the 2 Oregon subspecies of red tree voles (P. l. longicaudus and P. l. silvicola). Our data further indicated a close relationship between tree voles and albipes, validating inclusion of albipes in the subgenus Arborimus. These 3 congeners shared a closer relationship to P. intermedius than to other arvicolids. A moderate association between porno and albipes was indicated by maximum parsimony and neighbor-joining phylogenetic analyses. Molecular clock estimates suggest a Pleistocene radiation of the Arborimus clade, which is concordant with pulses of diversification observed in other murid rodents. The generic rank of Arborimus is subject to interpretation of data.

  15. Stability enhancement of cytochrome c through heme deprotonation and mutations.

    Science.gov (United States)

    Sonoyama, Takafumi; Hasegawa, Jun; Uchiyama, Susumu; Nakamura, Shota; Kobayashi, Yuji; Sambongi, Yoshihiro

    2009-01-01

    The chemical denaturation of Pseudomonas aeruginosa cytochrome c(551) variants was examined at pH 5.0 and 3.6. All variants were stabilized at both pHs compared with the wild-type. Remarkably, the variants carrying the F34Y and/or E43Y mutations were more stabilized than those having the F7A/V13M or V78I ones at pH 5.0 compared with at pH 3.6 by ~3.0-4.6 kJ/mol. Structural analyses predicted that the side chains of introduced Tyr-34 and Tyr-43 become hydrogen donors for the hydrogen bond formation with heme 17-propionate at pH 5.0, but less efficiently at pH 3.6, because the propionate is deprotonated at the higher pH. Our results provide an insight into a stabilization strategy for heme proteins involving variation of the heme electronic state and introduction of appropriate mutations.

  16. Multifunctional Cytochrome c: Learning New Tricks from an Old Dog.

    Science.gov (United States)

    Alvarez-Paggi, Damián; Hannibal, Luciana; Castro, María A; Oviedo-Rouco, Santiago; Demicheli, Veronica; Tórtora, Veronica; Tomasina, Florencia; Radi, Rafael; Murgida, Daniel H

    2017-11-08

    Cytochrome c (cyt c) is a small soluble heme protein characterized by a relatively flexible structure, particularly in the ferric form, such that it is able to sample a broad conformational space. Depending on the specific conditions, interactions, and cellular localization, different conformations may be stabilized, which differ in structure, redox properties, binding affinities, and enzymatic activity. The primary function is electron shuttling in oxidative phosphorylation, and is exerted by the so-called native cyt c in the intermembrane mitochondrial space of healthy cells. Under pro-apoptotic conditions, however, cyt c gains cardiolipin peroxidase activity, translocates into the cytosol to engage in the intrinsic apoptotic pathway, and enters the nucleus where it impedes nucleosome assembly. Other reported functions include cytosolic redox sensing and involvement in the mitochondrial oxidative folding machinery. Moreover, post-translational modifications such as nitration, phosphorylation, and sulfoxidation of specific amino acids induce alternative conformations with differential properties, at least in vitro. Similar structural and functional alterations are elicited by biologically significant electric fields and by naturally occurring mutations of human cyt c that, along with mutations at the level of the maturation system, are associated with specific diseases. Here, we summarize current knowledge and recent advances in understanding the different structural, dynamic, and thermodynamic factors that regulate the primary electron transfer function, as well as alternative functions and conformations of cyt c. Finally, we present recent technological applications of this moonlighting protein.

  17. Respiration control of multicellularity in Bacillus subtilis by a complex of the cytochrome chain with a membrane-embedded histidine kinase

    Energy Technology Data Exchange (ETDEWEB)

    Kolodkin-Gal, I; Elsholz, AKW; Muth, C; Girguis, PR; Kolter, R; Losick, R

    2013-04-29

    Bacillus subtilis forms organized multicellular communities known as biofilms wherein the individual cells are held together by a self-produced extracellular matrix. The environmental signals that promote matrix synthesis remain largely unknown. We discovered that one such signal is impaired respiration. Specifically, high oxygen levels suppressed synthesis of the extracellular matrix. In contrast, low oxygen levels, in the absence of an alternative electron acceptor, led to increased matrix production. The response to impaired respiration was blocked in a mutant lacking cytochromes caa(3) and bc and markedly reduced in a mutant lacking kinase KinB. Mass spectrometry of proteins associated with KinB showed that the kinase was in a complex with multiple components of the aerobic respiratory chain. We propose that KinB is activated via a redox switch involving interaction of its second transmembrane segment with one or more cytochromes under conditions of reduced electron transport. In addition, a second kinase (KinA) contributes to the response to impaired respiration. Evidence suggests that KinA is activated by a decrease in the nicotinamide adenine dinucleotide (NAD(+))/NADH ratio via binding of NAD(+) to the kinase in a PAS domain A-dependent manner. Thus, B. subtilis switches from a unicellular to a multicellular state by two pathways that independently respond to conditions of impaired respiration.

  18. Respiration control of multicellularity in Bacillus subtilis by a complex of the cytochrome chain with a membrane-embedded histidine kinase

    Science.gov (United States)

    Kolodkin-Gal, Ilana; Elsholz, Alexander K.W.; Muth, Christine; Girguis, Peter R.; Kolter, Roberto; Losick, Richard

    2013-01-01

    Bacillus subtilis forms organized multicellular communities known as biofilms wherein the individual cells are held together by a self-produced extracellular matrix. The environmental signals that promote matrix synthesis remain largely unknown. We discovered that one such signal is impaired respiration. Specifically, high oxygen levels suppressed synthesis of the extracellular matrix. In contrast, low oxygen levels, in the absence of an alternative electron acceptor, led to increased matrix production. The response to impaired respiration was blocked in a mutant lacking cytochromes caa3 and bc and markedly reduced in a mutant lacking kinase KinB. Mass spectrometry of proteins associated with KinB showed that the kinase was in a complex with multiple components of the aerobic respiratory chain. We propose that KinB is activated via a redox switch involving interaction of its second transmembrane segment with one or more cytochromes under conditions of reduced electron transport. In addition, a second kinase (KinA) contributes to the response to impaired respiration. Evidence suggests that KinA is activated by a decrease in the nicotinamide adenine dinucleotide (NAD+)/NADH ratio via binding of NAD+ to the kinase in a PAS domain A-dependent manner. Thus, B. subtilis switches from a unicellular to a multicellular state by two pathways that independently respond to conditions of impaired respiration. PMID:23599347

  19. Photo-excitation of electrons in cytochrome c oxidase as a theory of the mechanism of the increase of ATP production in mitochondria by laser therapy

    Science.gov (United States)

    Zielke, Andrzej

    2014-02-01

    The hypothesis explains the molecular basis for restoring mitochondrial function by laser therapy. It also explains how laser therapy reverses both excessive oxidation (lack of NADH/FADH2) and excessive reduction (lack of O2) states of cytochrome c oxidase complex. It is proposed that photons interact with heme molecules of cytochrome c oxidase. A molecule of heme contains a porphyrin ring and an atom of iron in the center. The iron atom (Fe) can switch oxidation states back and forth between ferrous (Fe2+) and ferric (Fe3+) by accepting or releasing an electron. The porphyrin ring is a complex aromatic molecule that has 26 pi electrons which are "delocalized", spinning in the carbon rings creating a resonating electromagnetic cloud. Photons with similar wavelengths are absorbed by the cloud increasing its energy. The energy is then passed on to the centrally located atom of iron existing in a reduced state (Fe2+). The electrons on the orbits of the iron atom accept this electromagnetic energy, and change orbitals to a higher energetic level. If the energy is sufficient, electrons leave the atom entirely. If this occurs, Fe2+ become oxidized to Fe3+ releasing electrons, thus restoring electron flow and the production of ATP. At the same time, electrons freed from complex IV may have sufficient energy to be picked by NAD+/FADH and re-enter the chain at the complex I or II amplifying the flow of electrons.

  20. Lack of drug interaction between omeprazole, lansoprazole, pantoprazole and theophylline

    Science.gov (United States)

    Dilger, Karin; Zheng, Zhichang; Klotz, Ulrich

    1999-01-01

    Aims Theophylline is a model substrate of cytochrome P4501A2. The ability of the proton pump inhibitors (PPI) omeprazole, lansoprazole and pantoprazole to induce cytochrome P4501A2 has not yet been unequivocally resolved. The aim of this comprehensive study was to compare directly the effect of the three PPI on the absorption and disposition of theophylline. Methods Twenty healthy, nonsmoking, male and female volunteers (extensive metabolisers of cytochrome P4502C19 and Helicobacter pylori negative) participated in a randomized, double-blind, four-period, placebo-controlled crossover study. In each of the four periods they received either omeprazole (40 mg), lansoprazole (60 mg), pantoprazole (80 mg) or placebo once daily for 10 days. Sustained release theophylline (350 mg twice daily) was coadministered from day 8–10. Pharmacokinetics of theophylline as well as of all three PPI were determined at steady-state (day 10). Results In all periods, point estimates and 90% confidence intervals of the area under the concentration-time curves (AUC), maximum steady-state concentrations and peak-trough fluctuations of theophylline were not altered by PPI pretreatment and met the required limits for bioequivalence. Point estimates (90% confidence intervals) of the AUC ratios of theophylline plus PPI to theophylline alone were 0.92 (0.87–0.97), 0.90 (0.85–0.95) and 1.00 (0.95–1.06) for omeprazole, lansoprazole and pantoprazole, respectively. Conclusions Concomitant intake of omeprazole, lansoprazole or pantoprazole at high therapeutic doses does not affect the absorption and disposition of theophylline. PMID:10510158

  1. [Anatomy and histology characteristics of lymph node in nude mice].

    Science.gov (United States)

    Sun, R; Gao, B; Guo, C B

    2017-10-18

    To compare the differences of anatomical and histological characteristics of lymph nodes between BALB/c nude mice and BALB/c mice. Firstly, twenty BALB/c nude mice and twenty BALB/c mice were dissected by using a surgical microscope. Secondly, the differences of T cells and B cells at the lymph node were compared by the expressions of CD 3 and CD 20 immunohistochemistry dyes. There were, on average, 23 nodes per mouse contained within the large lymph node assembly in the BALB/c nude mouse. The anatomical features of the lymph node distribution in the nude mice were mainly found in the neck with relatively higher density. There were two lymph nodes both in the submandible lymph nodes group and in the superficial cervical lymph nodes group (the constituent ratios were 95% and 90%, respectively) in the BALB/c nude mice, but there were four lymph nodes (the constituent ratios were 95% and 90%, respectively) in the BALB/c mice. There were significant difference between the BALB/c nude mice and the BALB/c mice. Mostly there were two lymph nodes of deep cervical lymph nodes both in the BALB/c nude mice and the BALB/c mice (the constituent ratios were 95% and 100%, respectively). There were no significant difference between the BALB/c nude mice and the BALB/c mice. We confirmed that the number of CD 3 -positive T lymphocytes in lymph nodes of the nude mice decreased greatly as compared with the BALB/c mice. Expressions of CD3 in T cells were 95% and 100% in the BALB/c nude mice and in the BALB/c mice, respectively. There were significant differences between the BALB/c nude mice and the BALB/c mice. Expressions of CD20 in B cells were 95% and 100% in the BALB/c nude mice and in the BALB/c mice, respectively. There was no significant difference between the BALB/c nude mice and BALB/c mice. The anatomical pictures of lymph node distribution in the nude mouse will be benefit to those who are interested. The anatomical features of the lymph node local higher density in neck of

  2. Alteration in the Expression of Cytochrome P450s (CYP1A1, CYP2E1, and CYP3A11 in the Liver of Mouse Induced by Microcystin-LR

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    Bangjun Zhang

    2015-03-01

    Full Text Available Microcystins (MCs are cyclic heptapeptide toxins and can accumulate in the liver. Cytochrome P450s (CYPs play an important role in the biotransformation of endogenous substances and xenobiotics in animals. It is unclear if the CYPs are affected by MCs exposure. The objective of this study was to evaluate the effects of microcystin-LR (MCLR on cytochrome P450 isozymes (CYP1A1, CYP2E1, and CYP3A11 at mRNA level, protein content, and enzyme activity in the liver of mice the received daily, intraperitoneally, 2, 4, and 8 µg/kg body weight of MCLR for seven days. The result showed that MCLR significantly decreased ethoxyresorufin-O-deethylase (EROD (CYP1A1 and erythromycin N-demthylase (ERND (CYP3A11 activities and increased aniline hydroxylase (ANH activity (CYP2E1 in the liver of mice during the period of exposure. Our findings suggest that MCLR exposure may disrupt the function of CYPs in liver, which may be partly attributed to the toxicity of MCLR in mice.

  3. Polarography of cytochrome c in ammoniacal buffers containing cobalt ions. The effect of the protein conformation.

    Science.gov (United States)

    Brabec, V

    1985-12-01

    Catalytic currents yielded by cytochrome c in ammoniacal buffers containing cobalt ions at a dropping mercury electrode (Brdicka's catalytic currents) were investigated by means of direct current, differential pulse, normal pulse (NP) and phase-selective alternating current polarography. It was found that Brdicka's catalytic current of cytochrome c, (the more negative part of Brdicka's double wave, wave B) is influenced by the presence of cytochrome c denaturants in the background solution. The wave B rose with the increasing concentrations of urea and sodium perchlorate, and increased in parallel with absorbance changes at 409 and 695 nm measured for identical cytochrome c solutions. The latter absorbance changes reflect unfolding of cytochrome c molecules in the bulk of solution by these denaturants. The results of NP polarography (a technique working with large potential excursion during the drop lifetime) indicate that in Brdicka's solution cytochrome c could extensively be unfolded due to its adsorption at the mercury electrode, polarized to potentials around that of zero charge.

  4. Unique organizational and functional features of the cytochrome c maturation system in Shewanella oneidensis.

    Directory of Open Access Journals (Sweden)

    Miao Jin

    Full Text Available Shewanella are renowned for their ability to respire on a wide range of electron acceptors, which has been partially accredited to the presence of a large number of the c-type cytochromes. In the model species S. oneidensis MR-1, at least 41 genes encode c-type cytochromes that are predicted to be intact, thereby likely functional. Previously, in-frame deletion mutants for 36 of these genes were obtained and characterized. In this study, first we completed the construction of an entire set of c-type cytochrome mutants utilizing a newly developed att-based mutagenesis approach, which is more effective and efficient than the approach used previously by circumventing the conventional cloning. Second, we investigated the cytochrome c maturation (Ccm system in S. oneidensis. There are two loci predicted to encode components of the Ccm system, SO0259-SO0269 and SO0476-SO0478. The former is proven essential for cytochrome c maturation whereas the latter is dispensable. Unlike the single operon organization observed in other γ-proteobacteria, genes at the SO0259-SO0269 locus are uniquely organized into four operons, ccmABCDE, scyA, SO0265, and ccmFGH-SO0269. Functional analysis revealed that the SO0265 gene rather than the scyA and SO0269 genes are relevant to cytochrome c maturation.

  5. Interface Adsorption Taking the Most Advantageous Conformation for Electron Transfer Between Graphene and Cytochrome c.

    Science.gov (United States)

    Hu, Benfeng; Ge, Zhenpeng; Li, Xiaoyi

    2015-07-01

    Most designed functions in biomedical nanotechnology are directly influenced by interactions of biological molecules with nano surfaces. Here, we explored and detected the most favorable adsorption conformation of cytochrome c on graphene by measuring the adsorption energy, the number of contact atoms, and the minimal distance between protein and surface. From the root mean square deviation of the protein backbone, the radius of gyration, and the proportion of secondary structure, it is revealed that cytochrome c does not deform significantly and the secondary structures are preserved to a large extent. The residues, Lys, Phe and Thr contribute significantly to the adsorption of cytochrome c to graphene. The long hydrophobic and flexible alkyl tail of Lys, the π-π stacking interaction between Phe and graphene, and the presence of abundant Thr constitute the driving force for the stable adsorption of cytochrome c on graphene. Cytochrome c is adsorbed to graphene with the group heme lying almost perpendicular to the graphene, and the distance between Fe atom and the graphene is 10.15 A, which is shorter than that between electron donor and receptor in many other biosystems. All the results suggest that the most favorable adsorption takes the most advantageous conformation for electron transfer, which promotes significantly the electron transfer between graphene and cytochrome c. The findings might provide new and important information for designs of biomedical devices or products with graphene-based nanomaterials.

  6. Multi-heme Cytochromes in Shewanella oneidensis MR-1: Structures, functions and opportunities

    Energy Technology Data Exchange (ETDEWEB)

    Breuer, Marian; Rosso, Kevin M.; Blumberger, Jochen; Butt, Julea N.

    2014-11-05

    Multi-heme cytochromes are employed by a range of microorganisms to transport electrons over distances of up to tens of nanometers. Perhaps the most spectacular utilization of these proteins is in the reduction of extracellular solid substrates, including electrodes and insoluble mineral oxides of Fe(III) and Mn(III/IV), by species of Shewanella and Geobacter. However, multi-heme cytochromes are found in numerous and phylogenetically diverse prokaryotes where they participate in electron transfer and redox catalysis that contributes to biogeochemical cycling of N, S and Fe on the global scale. These properties of multi-heme cytochromes have attracted much interest and contributed to advances in bioenergy applications and bioremediation of contaminated soils. Looking forward there are opportunities to engage multi-heme cytochromes for biological photovoltaic cells, microbial electrosynthesis and developing bespoke molecular devices. As a consequence it is timely to review our present understanding of these proteins and we do this here with a focus on the multitude of functionally diverse multi-heme cytochromes in Shewanella oneidensis MR-1. We draw on findings from experimental and computational approaches which ideally complement each other in the study of these systems: computational methods can interpret experimentally determined properties in terms of molecular structure to cast light on the relation between structure and function. We show how this synergy has contributed to our understanding of multi-heme cytochromes and can be expected to continue to do so for greater insight into natural processes and their informed exploitation in biotechnologies.

  7. Double gene deletion reveals the lack of cooperation between PPARα and PPARβ in skeletal muscle

    International Nuclear Information System (INIS)

    Bedu, E.; Desplanches, D.; Pequignot, J.; Bordier, B.; Desvergne, B.

    2007-01-01

    The peroxisome proliferator-activated receptors (PPARs) are involved in the regulation of most of the pathways linked to lipid metabolism. PPARα and PPARβ isotypes are known to regulate muscle fatty acid oxidation and a reciprocal compensation of their function has been proposed. Herein, we investigated muscle contractile and metabolic phenotypes in PPARα-/-, PPARβ-/-, and double PPARα-/- β-/- mice. Heart and soleus muscle analyses show that the deletion of PPARα induces a decrease of the HAD activity (β-oxidation) while soleus contractile phenotype remains unchanged. A PPARβ deletion alone has no effect. However, these mild phenotypes are not due to a reciprocal compensation of PPARβ and PPARα functions since double gene deletion PPARα-PPARβ mostly reproduces the null PPARα-mediated reduced β-oxidation, in addition to a shift from fast to slow fibers. In conclusion, PPARβ is not required for maintaining skeletal muscle metabolic activity and does not compensate the lack of PPARα in PPARα null mice

  8. The 14CO2 breath test: Facilities and limitations of a rapid and noninvasive method for in vivo evaluation of modified hepatic cytochrome P-450 - a critique

    International Nuclear Information System (INIS)

    Bruech, M.; Kling, L.; Legrum, W.; Maser, E.

    1986-01-01

    By means of the breath test technique the cascade from O-demethylations to CO 2 was investigated after pretreatment of mice with warfarin, phenobarbital, cobaltous chloride, sodium vanadate and metyrapone. It was the intention to examine the validity of the technique with respect to cytochrome P-450 activity. Therefore three different radioactive labeled substrates, i.e., hydrogen carbonate, formate and xenobiotics, were applied at three different levels of the one-carbon pathway and were utilized to demonstrate possible interference of the modifiers with the sequence from O-demethylation to CO 2 . Real in vivo information about a modified cytochrome P-450 system can be obtained using model substrates carefully selected with regard to the type of expected modification of the monooxygenase system. In addition, a parallel monitoring of the consecutive reaction sequence by measuring the conversion of formate to CO 2 is necessary in order to guarantee the validity of the in vivo technique in visualizing the activity of the hepatic monooxygenase system. (orig.)<