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Howell JM, Dunton E, Creed KE, Quinlivan R, Sewry C. Investigating sodium valproate as a treatment for McArdle disease in sheep. Neuromuscul Disord 2014; 25:111-9. [PMID: 25455802 DOI: 10.1016/j.nmd.2014.10.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2014] [Revised: 09/01/2014] [Accepted: 10/04/2014] [Indexed: 11/26/2022]
Abstract
McArdle disease is due to an absence of the enzyme muscle glycogen phosphorylase and results in significant physical impairment in humans. We hypothesised that sodium valproate, an HDAC inhibitor, might have the ability to up-regulate the enzyme. We treated McArdle sheep with sodium valproate given enterically at 20-60 mg/kg body wt. Compared with untreated control animals, there was increased expression of phosphorylase in muscle fibres. The response was dose dependent and reached a maximum 2 hours after the application and increased with repeated applications. Improvement in mobility could not be demonstrated. These findings suggest that sodium valproate is a potential therapeutic treatment for McArdle disease.
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Affiliation(s)
- J McC Howell
- School of Veterinary and Life Sciences, Murdoch University, Perth, Western Australia, Australia; Australian Neuro-Muscular Research Institute, CNND, University of Western Australia, Perth, Western Australia, Australia.
| | - E Dunton
- School of Veterinary and Life Sciences, Murdoch University, Perth, Western Australia, Australia
| | - K E Creed
- School of Veterinary and Life Sciences, Murdoch University, Perth, Western Australia, Australia
| | - R Quinlivan
- Centre for Neuromuscular Diseases, National Hospital for Neurology and Neurosurgery, London, United Kingdom
| | - C Sewry
- Robert Jones and Agnes Hunt Orthopaedic hospital, Oswestry, United Kingdom
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Howell JM, Walker KR, Creed KE, Dunton E, Davies L, Quinlivan R, Karpati G. Phosphorylase re-expression, increase in the force of contraction and decreased fatigue following notexin-induced muscle damage and regeneration in the ovine model of McArdle disease. Neuromuscul Disord 2013; 24:167-77. [PMID: 24309536 DOI: 10.1016/j.nmd.2013.10.003] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2013] [Revised: 10/07/2013] [Accepted: 10/18/2013] [Indexed: 11/19/2022]
Abstract
McArdle disease is caused by a deficiency of myophosphorylase and currently a satisfactory treatment is not available. The injection of notexin into, or the layering of notexin onto, the muscles of affected sheep resulted in necrosis followed by regeneration of muscle fibres with the expression of both non-muscle isoforms of phosphorylase within the fibres and a reduction of the amount of glycogen in the muscle with an increase in the strength of contraction and a decrease in fatiguability in the muscle fibres. The sustained re-expression of both the brain and liver isoforms of phosphorylase within the muscle fibres provides further emphasis that strategies to enhance the re-expression of these isoforms should be investigated as a possible treatment for McArdle disease.
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Affiliation(s)
- J McC Howell
- School of Veterinary and Life Sciences, Murdoch University, Perth 6150, Western Australia, Australia; Australian Neuro-Muscular Research Institute,CNND, University of Western Australia, Perth 6150, Western Australia, Australia.
| | - K R Walker
- Centre for Medical Research, University of Western Australia, Perth 6150, Western Australia, Australia
| | - K E Creed
- School of Veterinary and Life Sciences, Murdoch University, Perth 6150, Western Australia, Australia
| | - E Dunton
- School of Veterinary and Life Sciences, Murdoch University, Perth 6150, Western Australia, Australia
| | - L Davies
- School of Veterinary and Life Sciences, Murdoch University, Perth 6150, Western Australia, Australia
| | - R Quinlivan
- Centre for Neuromuscular Diseases, National Hospital for Neurology and Neurosurgery, London, United Kingdom
| | - G Karpati
- Montreal Neurological Institute, McGill University, Montreal, Quebec, Canada
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Prathipati P, Pandey G, Saxena AK. CoMFA and Docking Studies on Glycogen Phosphorylase a Inhibitors as Antidiabetic Agents. J Chem Inf Model 2004; 45:136-45. [PMID: 15667139 DOI: 10.1021/ci049762u] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Glycogen phosphorylase (GP(a)) is a specific target for the design of inhibitors and may prevent glycogenolysis under high glucose conditions in type II diabetes. The carboxamides first reported by Hoover D. J. et al. (J. Med. Chem. 1998, 41, 2934-2938) are one of the major classes of GP(a) inhibitors other than glucose derivatives. The recent, X-ray crystallographic analyses (Oikonomakos et al. Biochim. Biophys. Acta 2003, 1647, 325-332) have revealed a distinct mechanism of action for these inhibitors, which bind at a new allosteric site away from the inhibitory and catalytic sites. To elucidate the essential structural and physicochemical requirements responsible for binding to the GP(a) enzyme and to develop predictive models, CoMFA and docking studies have been carried out on a series of indole-2-carboxamide derivates. The CoMFA model developed using pharmacophoric alignments and hydrogen-bonding fields demonstrated high predictive ability against the training (r2 = 0.98, q2 = 0.68) and the test set (r2pred = 0.85). Further the superimposition of PLS coefficient contour maps from CoMFA with the GP(a) active site (PDB: 1lwo) has shown a high level of compatibility.
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Affiliation(s)
- Philip Prathipati
- Medicinal Chemistry Division, Central Drug Research Institute, Chatter Manzil Palace, Lucknow-226 001, India
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Hoover DJ, Lefkowitz-Snow S, Burgess-Henry JL, Martin WH, Armento SJ, Stock IA, McPherson RK, Genereux PE, Gibbs EM, Treadway JL. Indole-2-carboxamide inhibitors of human liver glycogen phosphorylase. J Med Chem 1998; 41:2934-8. [PMID: 9685232 DOI: 10.1021/jm980264k] [Citation(s) in RCA: 88] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Affiliation(s)
- D J Hoover
- Departments of Cardiovascular and Metabolic Diseases Medicinal Chemistry, Exploratory Medicinal Biology, and Cardiovascular and Metabolic Diseases Biology, Central Research Division, Pfizer Inc., Groton, Connecticut 06340, USA
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Froman BE, Tait RC, Gorin FA. Role of E and CArG boxes in developmental regulation of muscle glycogen phosphorylase promoter during myogenesis. DNA Cell Biol 1998; 17:105-15. [PMID: 9502427 DOI: 10.1089/dna.1998.17.105] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Muscle glycogen phosphorylase (MGP) transcript and protein levels increase during skeletal muscle development in tandem with the products of other muscle genes responsible for glucose and glycogen metabolism. Previous studies demonstrated that a 269 bp region 5' to exon 1 of MGP is sufficient for developmental regulation in the C2C12 myogenic cell line (Froman et al., 1994). This genomic region (-209 to +60) contains four consensus E box motifs, a CArG-like sequence, and a GC-rich domain. Native MGP transcripts were not detected in pluripotent CH310T1/2 fibroblasts, but low levels of MGP mRNA were measured in CH310T1/2 cells that were stably transfected with MyoD. Three of the E box motifs in the MGP proximal promoter interacted with C2C12 nuclear proteins. However, cotransfection of the MGP promoter with myogenic regulatory factors, including MyoD and myogenin, produced less than 2-fold activation compared with 20-fold activation of the desmin promoter. Mutational analyses of the MGP promoter demonstrated that increased expression in C2C12 myotubes did not require any of the E box motifs or the CArG-like element. A small region (-76 to -68) upstream of GC-rich domain (-64 to -51) significantly reduced promoter activities in both myoblasts and myotubes. The functional studies suggest that MGP is developmentally regulated during myogenesis by alternative pathways that utilize unidentified regulatory elements or ancillary factors.
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Affiliation(s)
- B E Froman
- Department of Neurology/Center for the Neurosciences, University of California Davis, 95616-8647, USA
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Pfeiffer B, Buse E, Meyermann R, Hamprecht B. Immunocytochemical localization of glycogen phosphorylase in primary sensory ganglia of the peripheral nervous system of the rat. Histochem Cell Biol 1995; 103:69-74. [PMID: 7736282 DOI: 10.1007/bf01464477] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Neuronal localization was investigated of glycogen phosphorylase (GP) in ganglia of the peripheral nervous system of the rat. Immunofluorescence and immunoenzymatic procedures were applied with a monoclonal anti-bovine brain GP antibody on paraformaldehyde-fixed, paraffin-embedded tissues. Immunoreactivity was only present in the somatic neurons of the mesencephalic trigeminal nucleus in the brain stem and in dorsal root ganglia (DRG), but not in the autonomic neurons of the superior cervical ganglia or in the sensory nuclei of the spinal cord. GP immunoreactivity was present as early as day 1 after birth. In the adult rat, staining was present in neurons of different sizes, and to varying intensities. No relationship was apparent between the staining intensities and morphologically distinguishable types of neurons. In DRG, the type of reactivity was the same from cervical to sacral ganglia. The selected occurrence of GP in specific neurons of the peripheral nervous system in contrast to the ubiquitous occurrence in all astrocytes of the central nervous system may indicate a different role of neuronal glycogen compared to astrocytic glycogen.
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Affiliation(s)
- B Pfeiffer
- Physiologisch-Chemisches Institut, University of Tübingen, Germany
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Froman BE, Herrick KR, Gorin FA. Regulation of the rat muscle glycogen phosphorylase-encoding gene during muscle cell development. Gene 1994; 149:245-52. [PMID: 7958997 DOI: 10.1016/0378-1119(94)90156-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The muscle isozyme of glycogen phosphorylase (MGP) catalyzes the hydrolysis hydrolysis of intracellular glycogen in mammalian tissues and is produced in skeletal muscle, brain and heart. The MGP gene is developmentally and neutrally regulated in skeletal muscle, but little is known about the gene's transcriptional regulation. We have isolated and characterized the 5' flanking region of rat MGP. Truncated portions of the MGP 5' flanking region were coupled to the bacterial cat reporter gene and used in transient transfection assays in the mouse muscle C2C12 cell line. The region between -211 and +62 contained the smallest regulatory domain capable of demonstrating developmentally regulated myogenic expression in C2C12 cells. This was in contrast with findings from another investigation that transfected this cell line with human MGP [Lockyer and McCracken, J. Biol. Chem. 266 (1991) 20262-20269]. A 172-nucleotide (nt) region between -839 and -666 functioned as a potent enhancer in C2C12 cells when coupled to its cognate promoter, but not when coupled to a simian virus 40 promoter. This rat MGP enhancer region is 78% identical to a comparable region of the human MGP 5' flanking region, but contains only one putative regulatory element that has been previously identified in other muscle genes. These data suggest that rat MGP transcription in C2C12 muscle cells is modulated by a potent enhancer that utilizes novel regulatory elements.
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Affiliation(s)
- B E Froman
- Department of Neurology, University of California, Davis 95616-8647
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Hudson JW, Hefferon KL, Crerar MM. Comparative analysis of species-independent, isozyme-specific amino-acid substitutions in mammalian muscle, brain and liver glycogen phosphorylases. BIOCHIMICA ET BIOPHYSICA ACTA 1993; 1164:197-208. [PMID: 7916624 DOI: 10.1016/0167-4838(93)90248-p] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Mammalian glycogen phosphorylases exist as three isozymes, muscle, brain and liver, that exhibit different responses to activation by phosphorylation and AMP, regardless of species. To identify species-independent, amino-acid substitutions that may be important determinants in differential isozyme control, we have sequenced cDNAs containing the entire protein coding regions of rat muscle and brain phosphorylases. Nucleotide sequence comparisons with rat liver, rabbit muscle, and human muscle, brain and liver phosphorylase genes, indicate that muscle and brain isozymes are more related to each other than to the liver isozyme. Unlike the human isozymes, there is little difference in GC content of codons in the rat isozymes. In relation to the rabbit muscle isozyme three-dimensional structure, amino-acid sequence comparisons indicate that very few nonconservative isozyme-specific substitutions occur in buried and dimer contact residues. There is strict conservation of active site, pyridoxal-phosphate-binding site and nucleoside inhibitor site residues, as well as CAP loop and helix-2 residues that comprise the phosphorylation activation and part of the AMP binding sites. In contrast, five liver isozyme-specific substitutions occur between residues 313-325 and another at residue 78 which may be important determinants in the poor activation of this isozyme by AMP. Substitutions in the brain isozyme at residues 21-23, 405 and 435 may play a role in its poor response to activation by phosphorylation.
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Affiliation(s)
- J W Hudson
- Department of Biology, York University, North York, Ontario, Canada
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Froman BE, Tait RC, Gorin FA, Horwitz BA, Stern JS. The gene encoding rat liver glycogen phosphorylase contains multiple polyadenylation signal sequences. Gene 1991; 109:269-74. [PMID: 1765272 DOI: 10.1016/0378-1119(91)90620-q] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
RNA blot analysis of rat liver and adipose tissues detected two glycogen phosphorylase (GP)-encoding transcripts. The polymerase chain reaction was used to characterize the 3'-noncoding region of the gene (L-GP) encoding liver-GP (L-GP) from the lean Zucker rat (Fa/Fa). Three distinct classes of colinear cDNA clones were identified by nucleotide (nt) sequence analysis, demonstrating that the L-GP gene contains at least three functional polyadenylation sites. The predominant L-GP transcript was generated by polyadenylation 130 nt 3' from the end of the coding region. A previously uncharacterized L-GP transcript is generated by polyadenylation at 346 nt 3' of the first polyadenylation site. Polyadenylation site selection does not appear to be regulated in a tissue-specific fashion. The relative steady-state L-GP mRNA levels in the different types of adipose tissues were comparable to, or exceeded transcript levels in liver.
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Affiliation(s)
- B E Froman
- Department of Neurology, University of California, Davis 95616
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Newgard CB, Norkiewicz B, Hughes SD, Frenkel RA, Coats WS, Martiniuk F, Johnston JM. Developmental expression of glycogenolytic enzymes in rabbit tissues: possible relationship to fetal lung maturation. BIOCHIMICA ET BIOPHYSICA ACTA 1991; 1090:333-42. [PMID: 1954255 DOI: 10.1016/0167-4781(91)90198-u] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Glycogen can be degraded in mammalian tissues by one of three isozymes of glycogen phosphorylase, termed muscle (M), liver (L) and brain (B) after the tissues in which they are preferentially expressed in adult animals, or by members of the family of alpha-glucosidases. In the current study, we have examined the developmental expression of these enzymes and their respective mRNAs in rabbit tissues, with particular emphasis on the developing lung, a tissue in which glycogen serves as an important source of carbon for surfactant phospholipid biosynthesis. Native gel activity assays and RNA blot hybridization analysis revealed that the B isoform of glycogen phosphorylase predominates in fetal and adult lung tissues, accompanied by a low level of expression of the M isoform. Total B and M phosphorylase activities increased during fetal lung development, with a peak at day 28 of gestation, then decreased to the adult level at term. This peak in activity coincided with the peak period of glycogen degradation in developing lung. While the increase in M isozyme activity was correlated with an increase in the level of its mRNA, B isoform mRNA showed no significant alteration during development, suggesting that the increase in B isoform activity is determined by a posttranscriptional mechanism. Analysis of phosphorylase mRNA levels in developing liver, skeletal muscle, brain and heart revealed a diverse expression pattern. The L isozyme mRNA was predominant at all time points in liver, the M isozyme was predominant at all time points in muscle, the B isozyme was predominant at all time points in brain, and heart contained a mixture of B and M mRNA in roughly equal ratios at all time points. Thus, our studies of phosphorylase mRNA in the rabbit provide no evidence for general predominance of the B isozyme in fetal tissues, or for isozyme 'switching' from the B to the L or M forms during development, as has been suggested by others. In addition to the increase in phosphorylase activity, acid, but not neutral alpha-glucosidase activity was found to increase significantly during fetal lung development, again with a peak at day 28 of gestation. Interestingly, RNA blot hybridization analysis with a probe for lysosomal alpha-glucosidase revealed no change in the level of expression of its 4 kb transcript in developing lung. Instead, we observed induction of a structurally related mRNA of 7.4 kb that peaked at day 28 of gestation. Hybridization with a sucrase/isomaltase-specific oligonucleotide excluded the possibility that the 7.4 kb transcript encodes this protein.(ABSTRACT TRUNCATED AT 400 WORDS)
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Affiliation(s)
- C B Newgard
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas 75235
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Ignacio PC, Baldwin BA, Vijayan VK, Tait RC, Gorin FA. Brain isozyme of glycogen phosphorylase: immunohistological localization within the central nervous system. Brain Res 1990; 529:42-9. [PMID: 2282504 DOI: 10.1016/0006-8993(90)90809-p] [Citation(s) in RCA: 52] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
An antibody specific for the predicted carboxyterminal sequence of the human brain isozyme of glycogen phosphorylase (alpha-1,4-D-glucan:orthophosphate D-glucosyltransferase, EC 2.4.1.1) was generated to verify the carboxyterminal amino acid sequence of this protein. The isozyme-specific antibody was used to examine the localization of this protein in primate and non-primate brain. The highest levels of the brain isozyme in cerebrum and cerebellum were found in fibrous astrocytes, many with glial processes that appear to terminate upon blood vessels.
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Affiliation(s)
- P C Ignacio
- Department of Neurology, University of California, Davis 95616
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Gelinas RP, Froman BE, McElroy F, Tait RC, Gorin FA. Human brain glycogen phosphorylase: characterization of fetal cDNA and genomic sequences. BRAIN RESEARCH. MOLECULAR BRAIN RESEARCH 1989; 6:177-85. [PMID: 2615594 DOI: 10.1016/0169-328x(89)90052-1] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Glycogen phosphorylase (alpha-1,4-glucan:orthophosphate D-glucosyltransferase, EC 2.4.1.1) is the rate-determining enzyme catalyzing glycogen degradation. Human brain has been demonstrated previously to express genes of both the liver and muscle isozymes of glycogen phosphorylase. In this report, a human fetal brain cDNA and genomic DNA corresponding to the brain isozyme of glycogen phosphorylase were isolated and characterized. Transcripts corresponding to this isozyme are present in human adult and fetal brain, and at low levels in other human fetal tissues. The predicted C-terminal sequence of the protein encoded by this cDNA and gene differ from that encoded by a phosphorylase cDNA isolated from a human astrocytoma cell line.
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Affiliation(s)
- R P Gelinas
- Department of Neurology, University of California, Davis 95616
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