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Tachikawa M, Hosoya KI. Transport characteristics of guanidino compounds at the blood-brain barrier and blood-cerebrospinal fluid barrier: relevance to neural disorders. Fluids Barriers CNS 2011; 8:13. [PMID: 21352605 PMCID: PMC3058069 DOI: 10.1186/2045-8118-8-13] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2010] [Accepted: 02/28/2011] [Indexed: 12/24/2022] Open
Abstract
Guanidino compounds (GCs), such as creatine, phosphocreatine, guanidinoacetic acid, creatinine, methylguanidine, guanidinosuccinic acid, γ-guanidinobutyric acid, β-guanidinopropionic acid, guanidinoethane sulfonic acid and α-guanidinoglutaric acid, are present in the mammalian brain. Although creatine and phosphocreatine play important roles in energy homeostasis in the brain, accumulation of GCs may induce epileptic discharges and convulsions. This review focuses on how physiologically important and/or neurotoxic GCs are distributed in the brain under physiological and pathological conditions. Transporters for GCs at the blood-brain barrier (BBB) and the blood-cerebrospinal fluid (CSF) barrier (BCSFB) have emerged as substantial contributors to GCs distribution in the brain. Creatine transporter (CRT/solute carrier (SLC) 6A8) expressed at the BBB regulates creatine concentration in the brain, and represents a major pathway for supply of creatine from the circulating blood to the brain. CRT may be a key factor facilitating blood-to-brain guanidinoacetate transport in patients deficient in S-adenosylmethionine:guanidinoacetate N-methyltransferase, the creatine biosynthetic enzyme, resulting in cerebral accumulation of guanidinoacetate. CRT, taurine transporter (TauT/SLC6A6) and organic cation transporter (OCT3/SLC22A3) expressed at the BCSFB are involved in guanidinoacetic acid or creatinine efflux transport from CSF. Interestingly, BBB efflux transport of GCs, including guanidinoacetate and creatinine, is negligible, though the BBB has a variety of efflux transport systems for synthetic precursors of GCs, such as amino acids and neurotransmitters. Instead, the BCSFB functions as a major cerebral clearance system for GCs. In conclusion, transport of GCs at the BBB and BCSFB appears to be the key determinant of the cerebral levels of GCs, and changes in the transport characteristics may cause the abnormal distribution of GCs in the brain seen in patients with certain neurological disorders.
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Affiliation(s)
- Masanori Tachikawa
- Department of Pharmaceutics, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama, Japan.
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Skelton MR, Schaefer TL, Graham DL, Degrauw TJ, Clark JF, Williams MT, Vorhees CV. Creatine transporter (CrT; Slc6a8) knockout mice as a model of human CrT deficiency. PLoS One 2011; 6:e16187. [PMID: 21249153 PMCID: PMC3020968 DOI: 10.1371/journal.pone.0016187] [Citation(s) in RCA: 80] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2010] [Accepted: 12/09/2010] [Indexed: 11/18/2022] Open
Abstract
Mutations in the creatine (Cr) transporter (CrT; Slc6a8) gene lead to absence of brain Cr and intellectual disabilities, loss of speech, and behavioral abnormalities. To date, no mouse model of CrT deficiency exists in which to understand and develop treatments for this condition. The purpose of this study was to generate a mouse model of human CrT deficiency. We created mice with exons 2–4 of Slc6a8 flanked by loxP sites and crossed these to Cre:CMV mice to create a line of ubiquitous CrT knockout expressing mice. Mice were tested for learning and memory deficits and assayed for Cr and neurotransmitter levels. Male CrT−/y (affected) mice lack Cr in the brain and muscle with significant reductions of Cr in other tissues including heart and testes. CrT−/y mice showed increased path length during acquisition and reversal learning in the Morris water maze. During probe trials, CrT−/y mice showed increased average distance from the platform site. CrT−/y mice showed reduced novel object recognition and conditioned fear memory compared to CrT+/y. CrT−/y mice had increased serotonin and 5-hydroxyindole acetic acid in the hippocampus and prefrontal cortex. Ubiquitous CrT knockout mice have learning and memory deficits resembling human CrT deficiency and this model should be useful in understanding this disorder.
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Affiliation(s)
- Matthew R Skelton
- Division of Neurology, Cincinnati Children's Research Foundation, and Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, Ohio, United States of America.
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Kim DW, Yeo SI, Ryu HJ, Kim JE, Song HK, Kwon OS, Choi SY, Kang TC. Effects of creatine and β-guanidinopropionic acid and alterations in creatine transporter and creatine kinases expression in acute seizure and chronic epilepsy models. BMC Neurosci 2010; 11:141. [PMID: 20979657 PMCID: PMC2978220 DOI: 10.1186/1471-2202-11-141] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2010] [Accepted: 10/28/2010] [Indexed: 11/12/2022] Open
Abstract
Background In order to confirm the roles of creatine (Cr) in epilepsy, we investigated the anti-convulsive effects of Cr, creatine transporter (CRT) and creatine kinases (CKs) against chemical-induced acute seizure activity and chronic epileptic seizure activity. Results Two hr after pilocarpine (PILO)-seizure induction, ubiquitous mitochondrial CK (uMtCK) immunoreactivity was unaltered as compared to control level. However, brain-type cytoplasm CK (BCK) immunoreactivity was decreased to 70% of control level. CRT immunoreactivity was decreased to 60% of control level. Following Cr or Tat-CK treatment, uMtCK or CRT immunoreactivity was unaffected, while BCK immunoreactivity in Cr treated group was increased to 3.6-fold of control levels. β-Guanidinopropionic acid (GPA, a competitive CRT inhibitor) reduced BCK and CRT expression. In addition, Cr and tat-BCK treatment delayed the beginning of seizure activity after PILO injection. However, GPA treatment induced spontaneous seizure activity without PILO treatment. In chronic epilepsy rats, both uMtCK and CRT immunoreactivities were reduced in the hippocampus. In contrast, BCK immunoreactivity was similar to that observed in control animals. Cr-, GPA and tat-BCK treatment could not change EEG. Conclusion Cr/CK circuit may play an important role in sustaining or exacerbating acute seizure activity, but not chronic epileptic discharge.
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Affiliation(s)
- Dae Won Kim
- Department of Biomedical Sciences, College of Life Science, Hallym University, Chunchon Kangwon-Do 200-702, Republic of Korea
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54
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Dodd JR, Birch NP, Waldvogel HJ, Christie DL. Functional and immunocytochemical characterization of the creatine transporter in rat hippocampal neurons. J Neurochem 2010; 115:684-93. [DOI: 10.1111/j.1471-4159.2010.06957.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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55
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Béard E, Braissant O. Synthesis and transport of creatine in the CNS: importance for cerebral functions. J Neurochem 2010; 115:297-313. [DOI: 10.1111/j.1471-4159.2010.06935.x] [Citation(s) in RCA: 118] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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56
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Wang L, Angley MT, Sorich MJ, Young RL, McKinnon RA, Gerber JP. Is there a role for routinely screening children with autism spectrum disorder for creatine deficiency syndrome? Autism Res 2010; 3:268-72. [DOI: 10.1002/aur.145] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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57
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Diagnosis of creatine metabolism disorders by determining creatine and guanidinoacetate in plasma and urine. Methods Mol Biol 2010; 603:175-85. [PMID: 20077070 DOI: 10.1007/978-1-60761-459-3_17] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
Creatine metabolism disorders include a creatine transporter deficiency, as well as, deficiencies of two enzymes involved in creatine synthesis, arginine-glycine amidinotransferase (AGAT) and guanidinoacetate methyltransferase (GAMT). Laboratory diagnosis of these disorders relies on the determination of creatine and guanidinoacetate in both plasma and urine. Here we describe a rapid HPLC/MS/MS method for these measurements using a normal phase HILIC column after analyte derivatization.
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58
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Wang L, Chen D, Yang L, Huang S, Zhang Y, Zhang H. Expression patterns of the creatine metabolism-related molecules AGAT, GAMT and CT1 in adult zebrafish Danio rerio. JOURNAL OF FISH BIOLOGY 2010; 76:1212-1219. [PMID: 20409172 DOI: 10.1111/j.1095-8649.2010.02555.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
AGAT, GAMT and CT1, three creatine synthesis and transport-related molecules, have been widely studied in mammals. To explore their homologous genes in adult zebrafish Danio rerio, the gene expression patterns of these three genes in D. rerio were investigated. The results reveal that AGAT, GAMT and CT1 are expressed widely in diverse tissues of D. rerio where the homologous genes in mammals are also expressed.
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Affiliation(s)
- L Wang
- Institute of Developmental Biology, Life Science College, Shandong University, Key Lab of Experimental Teratology of the Ministry of Education, Jinan, China
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Nasrallah F, Feki M, Kaabachi N. Creatine and creatine deficiency syndromes: biochemical and clinical aspects. Pediatr Neurol 2010; 42:163-71. [PMID: 20159424 DOI: 10.1016/j.pediatrneurol.2009.07.015] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/09/2009] [Revised: 06/10/2009] [Accepted: 07/30/2009] [Indexed: 11/28/2022]
Abstract
Creatine deficiency syndromes, which have only recently been described, represent a group of inborn errors of creatine synthesis (L-arginine-glycine amidinotransferase deficiency and guanidinoacetate methyltransferase deficiency) and transport (creatine transporter deficiency). Patients with creatine deficiency syndromes present with mental retardation expressive speech and language delay, and epilepsy. Patients with guanidinoacetate methyltransferase deficiency or creatine transporter deficiency may exhibit autistic behavior. The common denominator of these disorders is the depletion of the brain creatine pool, as demonstrated by in vivo proton magnetic resonance spectroscopy. For diagnosis, laboratory investigations start with analysis of guanidinoacetate, creatine, and creatinine in plasma and urine. Based on these findings, enzyme assays or DNA mutation analysis may be performed. The creatine deficiency syndromes are underdiagnosed, so the possibility should be considered in all children affected by unexplained mental retardation, seizures, and speech delay. Guanidinoacetate methyltransferase deficiency and arginine-glycine amidinotransferase deficiency are treatable by oral creatine supplementation, but patients with creatine transporter deficiency do not respond to this type of treatment.
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60
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Braissant O, Béard E, Torrent C, Henry H. Dissociation of AGAT, GAMT and SLC6A8 in CNS: Relevance to creatine deficiency syndromes. Neurobiol Dis 2010; 37:423-33. [DOI: 10.1016/j.nbd.2009.10.022] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2009] [Revised: 10/15/2009] [Accepted: 10/22/2009] [Indexed: 10/20/2022] Open
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Brosnan JT, Brosnan ME. Creatine metabolism and the urea cycle. Mol Genet Metab 2010; 100 Suppl 1:S49-52. [PMID: 20304692 DOI: 10.1016/j.ymgme.2010.02.020] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/20/2009] [Accepted: 02/10/2010] [Indexed: 11/27/2022]
Abstract
Because creatine and creatine phosphate are irreversibly converted to creatinine, there is a continuous need for their replacement. This occurs by means of diet and de novo synthesis. Dietary creatine is provided in animal products and can amount to about half of the required amount. Synthesis provides the remainder. Creatine synthesis is a major component of arginine metabolism, amounting to more than 20% of the dietary intake of this amino acid. Creatine metabolism is of importance to patients with urea cycle disorders in two ways, both related to arginine levels. In patients with arginase deficiency, markedly elevated arginine levels may result in higher concentrations of guanidinoacetate and higher rates of creatine synthesis. This is of concern because it is thought that elevated levels of guanidinoacetate may exert neurotoxic effects. In the case of the other urea cycle disorders, arginine levels are markedly decreased unless the patients are supplemented with this amino acid. Decreased levels of arginine may result in decreased rates of creatine synthesis. This may be compounded by the fact that such patients, maintained on low protein diets, will also have lower dietary creatine intakes. There is some evidence that this may decrease brain creatine levels which may contribute to the neurological symptoms exhibited by these patients. It is clear that patients with urea cycle disorders also have altered creatine metabolism. Whether this contributes in a significant way to their neurological symptoms remains an open question.
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Affiliation(s)
- John T Brosnan
- Department of Biochemistry, Memorial University of Newfoundland, St. John's, NL, Canada.
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62
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Braissant O. Ammonia toxicity to the brain: effects on creatine metabolism and transport and protective roles of creatine. Mol Genet Metab 2010; 100 Suppl 1:S53-8. [PMID: 20227315 DOI: 10.1016/j.ymgme.2010.02.011] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/13/2009] [Accepted: 02/08/2010] [Indexed: 11/17/2022]
Abstract
Hyperammonemia can provoke irreversible damage to the developing brain, with the formation of cortical atrophy, ventricular enlargement, demyelination or gray and white matter hypodensities. Among the various pathogenic mechanisms involved, alterations in cerebral energy have been demonstrated. In particular, we could show that ammonia exposure generates a secondary deficiency in creatine in brain cells, by altering the brain expression and activity of the genes allowing creatine synthesis (AGAT and GAMT) and transport (SLC6A8). On the other hand, it is known that creatine administration can exert protective effects in various neurodegenerative processes. We could also show that creatine co-treatment under ammonia exposure can protect developing brain cells from some of the deleterious effects of ammonia, in particular axonal growth impairment. This article focuses on the effects of ammonia exposure on creatine metabolism and transport in developing brain cells, and on the potential neuroprotective properties of creatine in the brain exposed to ammonium.
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Affiliation(s)
- Olivier Braissant
- Inborn Errors of Metabolism, Clinical Chemistry Laboratory, Center Hospitalier Universitaire Vaudois and University of Lausanne, Lausanne, Switzerland.
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63
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Braissant O. Current concepts in the pathogenesis of urea cycle disorders. Mol Genet Metab 2010; 100 Suppl 1:S3-S12. [PMID: 20227314 DOI: 10.1016/j.ymgme.2010.02.010] [Citation(s) in RCA: 92] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/25/2009] [Accepted: 02/08/2010] [Indexed: 12/14/2022]
Abstract
The common feature of urea cycle diseases (UCD) is a defect in ammonium elimination in liver, leading to hyperammonemia. This excess of circulating ammonium eventually reaches the central nervous system, where the main toxic effects of ammonium occur. These are reversible or irreversible, depending on the age of onset as well as the duration and the level of ammonium exposure. The brain is much more susceptible to the deleterious effects of ammonium during development than in adulthood, and surviving UCD patients may develop cortical and basal ganglia hypodensities, cortical atrophy, white matter atrophy or hypomyelination and ventricular dilatation. While for a long time, the mechanisms leading to these irreversible effects of ammonium exposure on the brain remained poorly understood, these last few years have brought new data showing in particular that ammonium exposure alters several amino acid pathways and neurotransmitter systems, cerebral energy, nitric oxide synthesis, axonal and dendritic growth, signal transduction pathways, as well as K(+) and water channels. All these effects of ammonium on CNS may eventually lead to energy deficit, oxidative stress and cell death. Recent work also proposed neuroprotective strategies, such as the use of NMDA receptor antagonists, nitric oxide inhibitors, creatine and acetyl-l-carnitine, to counteract the toxic effects of ammonium. Better understanding the pathophysiology of ammonium toxicity to the brain under UCD will allow the development of new strategies for neuroprotection.
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Affiliation(s)
- Olivier Braissant
- Inborn Errors of Metabolism, Clinical Chemistry Laboratory, Centre Hospitalier Universitaire Vaudois and University of Lausanne, CI 02/33, Lausanne, Switzerland.
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64
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Rae C. RE: Magnetic resonance spectroscopy of the brain: review of metabolites and clinical applications. Clin Radiol 2009; 64:1042-3. [DOI: 10.1016/j.crad.2009.06.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2009] [Accepted: 06/02/2009] [Indexed: 12/01/2022]
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65
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Immunohistochemical localisation of the creatine transporter in the rat brain. Neuroscience 2009; 163:571-85. [DOI: 10.1016/j.neuroscience.2009.06.065] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2009] [Revised: 06/26/2009] [Accepted: 06/29/2009] [Indexed: 11/22/2022]
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66
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Tachikawa M, Kasai Y, Yokoyama R, Fujinawa J, Ganapathy V, Terasaki T, Hosoya KI. The blood-brain barrier transport and cerebral distribution of guanidinoacetate in rats: involvement of creatine and taurine transporters. J Neurochem 2009; 111:499-509. [DOI: 10.1111/j.1471-4159.2009.06332.x] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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67
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Gualano B, Artioli GG, Poortmans JR, Lancha Junior AH. Exploring the therapeutic role of creatine supplementation. Amino Acids 2009; 38:31-44. [PMID: 19253023 DOI: 10.1007/s00726-009-0263-6] [Citation(s) in RCA: 99] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2009] [Accepted: 02/11/2009] [Indexed: 12/12/2022]
Abstract
Creatine (Cr) plays a central role in energy provision through a reaction catalyzed by phosphorylcreatine kinase. Furthermore, this amine enhances both gene expression and satellite cell activation involved in hypertrophic response. Recent findings have indicated that Cr supplementation has a therapeutic role in several diseases characterized by atrophic conditions, weakness, and metabolic disturbances (i.e., in the muscle, bone, lung, and brain). Accordingly, there has been an evidence indicating that Cr supplementation is capable of attenuating the degenerative state in some muscle disorders (i.e., Duchenne and inflammatory myopathies), central nervous diseases (i.e., Parkinson's, Huntington's, and Alzheimer's), and bone and metabolic disturbances (i.e., osteoporosis and type II diabetes). In light of this, Cr supplementation could be used as a therapeutic tool for the elderly. The aim of this review is to summarize the main studies conducted in this field and to highlight the scientific and clinical perspectives of this promising therapeutic supplement.
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Affiliation(s)
- Bruno Gualano
- Laboratory of Applied Nutrition and Metabolism, School of Physical Education and Sport, University of São Paulo, São Paulo, Brazil.
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68
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da Silva RP, Nissim I, Brosnan ME, Brosnan JT. Creatine synthesis: hepatic metabolism of guanidinoacetate and creatine in the rat in vitro and in vivo. Am J Physiol Endocrinol Metab 2009; 296:E256-61. [PMID: 19017728 PMCID: PMC2645018 DOI: 10.1152/ajpendo.90547.2008] [Citation(s) in RCA: 91] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/27/2008] [Accepted: 11/10/2008] [Indexed: 11/22/2022]
Abstract
Since creatinine excretion reflects a continuous loss of creatine and creatine phosphate, there is a need for creatine replacement, from the diet and/or by de novo synthesis. Creatine synthesis requires three amino acids, methionine, glycine, and arginine, and two enzymes, l-arginine:glycine amidinotransferase (AGAT), which produces guanidinoacetate acid (GAA), and guanidinoacetate methyltransferase (GAMT), which methylates GAA to produce creatine. In the rat, high activities of AGAT are found in the kidney, whereas high activities of GAMT occur in the liver. Rat hepatocytes readily convert GAA to creatine; this synthesis is stimulated by the addition of methionine, which increases cellular S-adenosylmethionine concentrations. These same hepatocytes are unable to produce creatine from methionine, arginine, and glycine. (15)N from (15)NH(4)Cl is readily incorporated into urea but not into creatine. Hepatic uptake of GAA is evident in vivo by livers of rats fed a creatine-free diet but not when rats were fed a creatine-supplemented diet. Rats fed the creatine-supplemented diet had greatly decreased renal AGAT activity and greatly decreased plasma [GAA] but no decrease in hepatic GAMT or in the capacity of hepatocytes to produce creatine from GAA. These studies indicate that hepatocytes are incapable of the entire synthesis of creatine but are capable of producing it from GAA. They also illustrate the interplay between the dietary provision of creatine and its de novo synthesis and point to the crucial role of renal AGAT expression in regulating creatine synthesis in the rat.
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Affiliation(s)
- Robin P da Silva
- Dept. of Biochemistry, Memorial Univ. of Newfoundland, St. John's, NL, Canada A1B3X9
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69
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Fons C, Sempere A, Arias A, López-Sala A, Póo P, Pineda M, Mas A, Vilaseca MA, Salomons GS, Ribes A, Artuch R, Campistol J. Arginine supplementation in four patients with X-linked creatine transporter defect. J Inherit Metab Dis 2008; 31:724-8. [PMID: 18925426 DOI: 10.1007/s10545-008-0902-1] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/22/2008] [Revised: 06/08/2008] [Accepted: 06/23/2008] [Indexed: 01/02/2023]
Abstract
BACKGROUND Treatment with oral creatine monohydrate has not shown efficacy in patients with creatine transporter deficiency (CRTR-D). Another therapeutic option proposed is L-arginine, the substrate for the enzyme L-arginine:glycine amidinotransferase (AGAT). We evaluate clinical characteristics and cerebral creatine replenishment after L-arginine therapy in four patients with CRTR-D. PATIENTS AND METHODS Four boys with genetically confirmed diagnosis of CRTR-D (ages 9-16 years) were supplemented with L-arginine (0.4 g/kg per day) for a period of 9 months. Treatment efficacy was evaluated by clinical and neuropsychological assessment and determination of creatine signals by brain proton magnetic resonance spectroscopy ((1)H-MRS). RESULTS Epileptic seizures remained well controlled with antiepileptic drugs in three cases, both before and after L-arginine supplementation. Vineland Adaptive Behaviour Scale did not show any change in communication, daily living skills, socialization or motor skills, and a lack of improvement in brain (1)H-MRS follow-up was observed. L-Arginine was discontinued at the end of the observation period. CONCLUSIONS Nine months of L-arginine supplementation did not show effectiveness in the four patients affected with CRTR-D in this protocol.
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Affiliation(s)
- C Fons
- Department of Child Neurology, Hospital Universitari Sant Joan de Déu, Centre for Research on Rare Diseases (CIBERER), Barcelona, Spain.
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70
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Tachikawa M, Fujinawa J, Takahashi M, Kasai Y, Fukaya M, Sakai K, Yamazaki M, Tomi M, Watanabe M, Sakimura K, Terasaki T, Hosoya KI. Expression and possible role of creatine transporter in the brain and at the blood-cerebrospinal fluid barrier as a transporting protein of guanidinoacetate, an endogenous convulsant. J Neurochem 2008; 107:768-78. [DOI: 10.1111/j.1471-4159.2008.05652.x] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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71
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Dezortova M, Jiru F, Petrasek J, Malinova V, Zeman J, Jirsa M, Hajek M. 1H MR spectroscopy as a diagnostic tool for cerebral creatine deficiency. MAGNETIC RESONANCE MATERIALS IN PHYSICS BIOLOGY AND MEDICINE 2008; 21:327-32. [PMID: 18726626 DOI: 10.1007/s10334-008-0137-z] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/28/2008] [Revised: 08/05/2008] [Accepted: 08/05/2008] [Indexed: 11/25/2022]
Abstract
OBJECTIVE Total creatine (tCr) constitutes one of the most prominent signals in human brain MR spectra. A significant decrease in the tCr signal indicates a severe disorder of creatine metabolism. We describe the potential of 1H MR spectroscopy in differential diagnosis of creatine transporter (SLC6A8) deficiency syndrome. MATERIALS AND METHODS Two siblings, a 7-year-old female presenting with mild psychomotor delay, and a 5-year-old male with severe psychomotor retardation, epilepsy and autistic spectrum of problems including speech delay, underwent MR examination because of suspected creatine deficiency. After the MRI examination, 1H MR spectroscopy using the CSI technique was performed. RESULTS Metabolic images of N-acetylaspartate, tCr and choline concentrations showed a very low tCr signal in the male, which was approximately three times lower than in his sister (male/female/controls: tCr=1.6/4.6/7.5 mM). Despite creatine supplementation, no improvement in clinical status and tCr concentration in the MR spectra of the male was observed and diagnosis of SLC6A8 deficiency was proposed. Sequence analysis of the SLC6A8 gene revealed a novel pathogenic frameshift mutation c.219delC; p.Asn74ThrfsX23, hemizygous in the male and heterozygous in the female. CONCLUSIONS The diagnosis of X-linked mental retardation caused by the SLC6A8 deficiency can be independently established by 1H MR spectroscopy.
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Affiliation(s)
- Monika Dezortova
- MR-Unit, Department of Diagnostic and Interventional Radiology, Institute for Clinical and Experimental Medicine, Videnska 1958/9, 140 21, Prague 4, Czech Republic.
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