1
|
Liufu T, Yu H, Yu J, Yu M, Tian Y, Ou Y, Deng J, Xing G, Wang Z. Complex I deficiency in m.3243A>G fibroblasts is alleviated by reducing NADH accumulation. Front Physiol 2023; 14:1164287. [PMID: 37650111 PMCID: PMC10464909 DOI: 10.3389/fphys.2023.1164287] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2023] [Accepted: 08/03/2023] [Indexed: 09/01/2023] Open
Abstract
Introduction: Mitochondrial disease is a spectrum of debilitating disorders caused by mutations in the mitochondrial DNA (mtDNA) or nuclear DNA that compromises the respiratory chain. Mitochondrial 3243A>G (m.3243 A>G) is the most common mutation showing great heterogeneity in phenotype. Previous studies have indicated that NADH: ubiquinone oxidoreductase (complex I) deficiency accompanied by a decreased nicotinamide adenine dinucleotide (NAD+)/reduced NAD+ (NADH) ratio may play a pivotal role in the pathogenesis of m.3243A>G mutation. Methods: To evaluate the potential effects of strategies targeting the imbalanced NAD+/NADH ratio in m.3243A>G mutation, we treated fibroblasts derived from patients with the m.3243 A>G mutation using nicotinamide riboside (NR) or mitochondria-targeted H2O-forming NADH oxidase (mitoLbNOX). Results: M.3243 A>G fibroblasts showed a significant reduction in complex I core subunit 6, complex I enzymatic activity, complex I-dependent oxygen consumption rate (OCR), and adenosine triphosphate (ATP) production compared to the controls. The NAD+/NADH ratio was also significantly reduced in m.3243 A>G fibroblasts, and, using fluorescence lifetime imaging microscopy, we also found that the NADH level was elevated in m.3243 A>G fibroblasts. After NR treatment, the NAD+/NADH ratio, complex I-dependent OCR, and ATP levels increased, whereas NADH levels remained unchanged. More excitingly, after treatment with mitoLbNOX, the NAD+/NADH ratio, complex I-independent OCR, and ATP levels increased more pronouncedly compared with the NR treatment group, accompanied by significantly reduced NADH levels. Discussion: The present study suggests that compared with repletion of NAD+ alone, the combination of this therapeutic modality with alleviation of NADH overload may amplify the treatment effect of restoring NAD+/NADH balance in m.3243A>G fibroblasts.
Collapse
Affiliation(s)
- Tongling Liufu
- Department of Neurology, Peking University First Hospital, Beijing, China
| | - Haiyan Yu
- Department of Clinical Laboratory, Peking University First Hospital, Beijing, China
| | - Jiaxi Yu
- Department of Neurology, Peking University First Hospital, Beijing, China
| | - Meng Yu
- Department of Neurology, Peking University First Hospital, Beijing, China
| | - Yue Tian
- Neuroscience Research Institute, Peking University, Beijing, China
| | - Yichun Ou
- Neuroscience Research Institute, Peking University, Beijing, China
| | - Jianwen Deng
- Department of Neurology, Peking University First Hospital, Beijing, China
- Beijing Key Laboratory of Neurovascular Disease Discovery, Beijing, China
| | - Guogang Xing
- Neuroscience Research Institute, Peking University, Beijing, China
| | - Zhaoxia Wang
- Department of Neurology, Peking University First Hospital, Beijing, China
- Beijing Key Laboratory of Neurovascular Disease Discovery, Beijing, China
| |
Collapse
|
2
|
Hu G, Ling C, Chi L, Thind MK, Furse S, Koulman A, Swann JR, Lee D, Calon MM, Bourdon C, Versloot CJ, Bakker BM, Gonzales GB, Kim PK, Bandsma RHJ. The role of the tryptophan-NAD + pathway in a mouse model of severe malnutrition induced liver dysfunction. Nat Commun 2022; 13:7576. [PMID: 36481684 PMCID: PMC9732354 DOI: 10.1038/s41467-022-35317-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2020] [Accepted: 11/29/2022] [Indexed: 12/13/2022] Open
Abstract
Mortality in children with severe malnutrition is strongly related to signs of metabolic dysfunction, such as hypoglycemia. Lower circulating tryptophan levels in children with severe malnutrition suggest a possible disturbance in the tryptophan-nicotinamide adenine dinucleotide (TRP-NAD+) pathway and subsequently in NAD+ dependent metabolism regulator sirtuin1 (SIRT1). Here we show that severe malnutrition in weanling mice, induced by 2-weeks of low protein diet feeding from weaning, leads to an impaired TRP-NAD+ pathway with decreased NAD+ levels and affects hepatic mitochondrial turnover and function. We demonstrate that stimulating the TRP-NAD+ pathway with NAD+ precursors improves hepatic mitochondrial and overall metabolic function through SIRT1 modulation. Activating SIRT1 is sufficient to induce improvement in metabolic functions. Our findings indicate that modulating the TRP-NAD+ pathway can improve liver metabolic function in a mouse model of severe malnutrition. These results could lead to the development of new interventions for children with severe malnutrition.
Collapse
Affiliation(s)
- Guanlan Hu
- grid.17063.330000 0001 2157 2938Department of Nutritional Sciences, Temerty Faculty of Medicine, University of Toronto, M5G 1A8 Toronto, Canada ,grid.42327.300000 0004 0473 9646Translational Medicine Program, The Hospital for Sick Children, M5G 0A4 Toronto, Canada
| | - Catriona Ling
- grid.17063.330000 0001 2157 2938Department of Nutritional Sciences, Temerty Faculty of Medicine, University of Toronto, M5G 1A8 Toronto, Canada ,grid.42327.300000 0004 0473 9646Translational Medicine Program, The Hospital for Sick Children, M5G 0A4 Toronto, Canada
| | - Lijun Chi
- grid.42327.300000 0004 0473 9646Translational Medicine Program, The Hospital for Sick Children, M5G 0A4 Toronto, Canada
| | - Mehakpreet K. Thind
- grid.17063.330000 0001 2157 2938Department of Nutritional Sciences, Temerty Faculty of Medicine, University of Toronto, M5G 1A8 Toronto, Canada ,grid.42327.300000 0004 0473 9646Translational Medicine Program, The Hospital for Sick Children, M5G 0A4 Toronto, Canada
| | - Samuel Furse
- grid.5335.00000000121885934Core Metabolomics and Lipidomics Laboratory, Wellcome Trust-Metabolic Research Laboratories, Institute of Metabolic Sciences, University of Cambridge, CB2 0QQ Cambridge, UK ,grid.4903.e0000 0001 2097 4353Biological Chemistry Group, Royal Botanic Gardens, Kew, Kew Green, TW9 3AE Richmond, UK
| | - Albert Koulman
- grid.5335.00000000121885934Core Metabolomics and Lipidomics Laboratory, Wellcome Trust-Metabolic Research Laboratories, Institute of Metabolic Sciences, University of Cambridge, CB2 0QQ Cambridge, UK
| | - Jonathan R. Swann
- grid.5491.90000 0004 1936 9297School of Human Development and Health, Faculty of Medicine, University of Southampton, SO16 6YD Southampton, UK ,grid.7445.20000 0001 2113 8111Department of Metabolism, Digestion and Reproduction, Faculty of Medicine, Imperial College London, SW7 2AZ London, UK
| | - Dorothy Lee
- grid.42327.300000 0004 0473 9646Translational Medicine Program, The Hospital for Sick Children, M5G 0A4 Toronto, Canada
| | - Marjolein M. Calon
- grid.42327.300000 0004 0473 9646Translational Medicine Program, The Hospital for Sick Children, M5G 0A4 Toronto, Canada
| | - Celine Bourdon
- grid.42327.300000 0004 0473 9646Translational Medicine Program, The Hospital for Sick Children, M5G 0A4 Toronto, Canada ,grid.511677.3The Childhood Acute Illness & Nutrition Network (CHAIN), Nairobi, Kenya
| | - Christian J. Versloot
- grid.4494.d0000 0000 9558 4598Laboratory of Pediatrics, Center for Liver, Digestive, and Metabolic Diseases, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Barbara M. Bakker
- grid.4494.d0000 0000 9558 4598Laboratory of Pediatrics, Center for Liver, Digestive, and Metabolic Diseases, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Gerard Bryan Gonzales
- grid.42327.300000 0004 0473 9646Translational Medicine Program, The Hospital for Sick Children, M5G 0A4 Toronto, Canada ,grid.4818.50000 0001 0791 5666Nutrition, Metabolism and Genomics Group, Division of Human Nutrition and Health, Wageningen University, Wageningen, The Netherlands
| | - Peter K. Kim
- grid.17063.330000 0001 2157 2938Department of Biochemistry, University of Toronto, M5S 1A8 Toronto, Canada ,grid.42327.300000 0004 0473 9646Cell Biology Program, The Hospital for Sick Children, M5G 0A4 Toronto, Canada
| | - Robert H. J. Bandsma
- grid.17063.330000 0001 2157 2938Department of Nutritional Sciences, Temerty Faculty of Medicine, University of Toronto, M5G 1A8 Toronto, Canada ,grid.42327.300000 0004 0473 9646Translational Medicine Program, The Hospital for Sick Children, M5G 0A4 Toronto, Canada ,grid.511677.3The Childhood Acute Illness & Nutrition Network (CHAIN), Nairobi, Kenya ,grid.4494.d0000 0000 9558 4598Laboratory of Pediatrics, Center for Liver, Digestive, and Metabolic Diseases, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands ,grid.42327.300000 0004 0473 9646Division of Gastroenterology, Hepatology, and Nutrition, The Hospital for Sick Children, M5G 0A4 Toronto, Canada
| |
Collapse
|
3
|
Tinker RJ, Lim AZ, Stefanetti RJ, McFarland R. Current and Emerging Clinical Treatment in Mitochondrial Disease. Mol Diagn Ther 2021; 25:181-206. [PMID: 33646563 PMCID: PMC7919238 DOI: 10.1007/s40291-020-00510-6] [Citation(s) in RCA: 39] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/27/2020] [Indexed: 12/11/2022]
Abstract
Primary mitochondrial disease (PMD) is a group of complex genetic disorders that arise due to pathogenic variants in nuclear or mitochondrial genomes. Although PMD is one of the most prevalent inborn errors of metabolism, it often exhibits marked phenotypic variation and can therefore be difficult to recognise. Current treatment for PMD revolves around supportive and preventive approaches, with few disease-specific therapies available. However, over the last decade there has been considerable progress in our understanding of both the genetics and pathophysiology of PMD. This has resulted in the development of a plethora of new pharmacological and non-pharmacological therapies at varying stages of development. Many of these therapies are currently undergoing clinical trials. This review summarises the latest emerging therapies that may become mainstream treatment in the coming years. It is distinct from other recent reviews in the field by comprehensively addressing both pharmacological non-pharmacological therapy from both a bench and a bedside perspective. We highlight the current and developing therapeutic landscape in novel pharmacological treatment, dietary supplementation, exercise training, device use, mitochondrial donation, tissue replacement gene therapy, hypoxic therapy and mitochondrial base editing.
Collapse
Affiliation(s)
- Rory J Tinker
- Wellcome Centre for Mitochondrial Research, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK
- Clinical and Translational Research Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK
| | - Albert Z Lim
- Wellcome Centre for Mitochondrial Research, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK
- Clinical and Translational Research Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK
| | - Renae J Stefanetti
- Wellcome Centre for Mitochondrial Research, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK
- Clinical and Translational Research Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK
| | - Robert McFarland
- Wellcome Centre for Mitochondrial Research, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK.
- Clinical and Translational Research Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK.
- NHS Highly Specialised Service for Rare Mitochondrial Disorders for Adults and Children, Newcastle upon Tyne Hospitals NHS Foundation Trust, Newcastle upon Tyne, UK.
| |
Collapse
|
4
|
Koňaříková E, Marković A, Korandová Z, Houštěk J, Mráček T. Current progress in the therapeutic options for mitochondrial disorders. Physiol Res 2020; 69:967-994. [PMID: 33129249 PMCID: PMC8549882 DOI: 10.33549/physiolres.934529] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2020] [Accepted: 10/02/2020] [Indexed: 12/20/2022] Open
Abstract
Mitochondrial disorders manifest enormous genetic and clinical heterogeneity - they can appear at any age, present with various phenotypes affecting any organ, and display any mode of inheritance. What mitochondrial diseases do have in common, is impairment of respiratory chain activity, which is responsible for more than 90% of energy production within cells. While diagnostics of mitochondrial disorders has been accelerated by introducing Next-Generation Sequencing techniques in recent years, the treatment options are still very limited. For many patients only a supportive or symptomatic therapy is available at the moment. However, decades of basic and preclinical research have uncovered potential target points and numerous compounds or interventions are now subjects of clinical trials. In this review, we focus on current and emerging therapeutic approaches towards the treatment of mitochondrial disorders. We focus on small compounds, metabolic interference, such as endurance training or ketogenic diet and also on genomic approaches.
Collapse
Affiliation(s)
- E Koňaříková
- Laboratory of Bioenergetics, Institute of Physiology Czech Acad. Sci., Prague, Czech Republic. ,
| | | | | | | | | |
Collapse
|
5
|
Pek NMQ, Phua QH, Ho BX, Pang JKS, Hor JH, An O, Yang HH, Yu Y, Fan Y, Ng SY, Soh BS. Mitochondrial 3243A > G mutation confers pro-atherogenic and pro-inflammatory properties in MELAS iPS derived endothelial cells. Cell Death Dis 2019; 10:802. [PMID: 31641105 PMCID: PMC6805858 DOI: 10.1038/s41419-019-2036-9] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2019] [Revised: 09/11/2019] [Accepted: 10/04/2019] [Indexed: 12/12/2022]
Abstract
Mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes (MELAS) syndrome is a mitochondrial disorder that is commonly caused by the m.3243A > G mutation in the MT-TL1 gene encoding for mitochondrial tRNA(Leu(UUR)). While clinical studies reported cerebral infarcts, atherosclerotic lesions, and altered vasculature and stroke-like episodes (SLE) in MELAS patients, it remains unclear how this mutation causes the onset and subsequent progression of the disease. Here, we report that in addition to endothelial dysfunction, diseased endothelial cells (ECs) were found to be pro-atherogenic and pro-inflammation due to high levels of ROS and Ox-LDLs, and high basal expressions of VCAM-1, in particular isoform b, respectively. Consistently, more monocytes were found to adhere to MELAS ECs as compared to the isogenic control, suggesting the presence of an atherosclerosis-like pathology in MELAS. Notably, these disease phenotypes in endothelial cells can be effectively reversed by anti-oxidant treatment suggesting that the lowering of ROS is critical for treating patients with MELAS syndrome.
Collapse
Affiliation(s)
- Nicole Min Qian Pek
- Disease Modeling and Therapeutics Laboratory, A*STAR Institute of Molecular and Cell Biology, 61 Biopolis Drive Proteos, Singapore, 138673, Singapore
| | - Qian Hua Phua
- Disease Modeling and Therapeutics Laboratory, A*STAR Institute of Molecular and Cell Biology, 61 Biopolis Drive Proteos, Singapore, 138673, Singapore
| | - Beatrice Xuan Ho
- Disease Modeling and Therapeutics Laboratory, A*STAR Institute of Molecular and Cell Biology, 61 Biopolis Drive Proteos, Singapore, 138673, Singapore.,Department of Biological Sciences, National University of Singapore, Singapore, 117543, Singapore
| | - Jeremy Kah Sheng Pang
- Disease Modeling and Therapeutics Laboratory, A*STAR Institute of Molecular and Cell Biology, 61 Biopolis Drive Proteos, Singapore, 138673, Singapore.,Department of Biological Sciences, National University of Singapore, Singapore, 117543, Singapore
| | - Jin-Hui Hor
- Disease Modeling and Therapeutics Laboratory, A*STAR Institute of Molecular and Cell Biology, 61 Biopolis Drive Proteos, Singapore, 138673, Singapore.,Department of Biological Sciences, National University of Singapore, Singapore, 117543, Singapore.,Neurotherapeutics Laboratory, A*STAR Institute of Molecular and Cell Biology, 61 Biopolis Drive Proteos, Singapore, 138673, Singapore
| | - Omer An
- Cancer Science Institute of Singapore, National University of Singapore, Singapore, 117599, Singapore
| | - Henry He Yang
- Cancer Science Institute of Singapore, National University of Singapore, Singapore, 117599, Singapore
| | - Yang Yu
- Center of Reproductive Medicine, Department of Obstetrics and Gynecology, Peking University Third Hospital, Beijing, 100191, China
| | - Yong Fan
- Key Laboratory for Major Obstetric Diseases of Guangdong Province, The Third Affiliated Hospital of Guangzhou Medical University, Guangzhou, 510150, China.
| | - Shi-Yan Ng
- Neurotherapeutics Laboratory, A*STAR Institute of Molecular and Cell Biology, 61 Biopolis Drive Proteos, Singapore, 138673, Singapore. .,Key Laboratory for Major Obstetric Diseases of Guangdong Province, The Third Affiliated Hospital of Guangzhou Medical University, Guangzhou, 510150, China. .,National Neuroscience Institute, 11 Jalan Tan Tock Seng, Singapore, 308433, Singapore. .,Department of Physiology, National University of Singapore, 2 Medical Dr, Singapore, 117593, Singapore.
| | - Boon-Seng Soh
- Disease Modeling and Therapeutics Laboratory, A*STAR Institute of Molecular and Cell Biology, 61 Biopolis Drive Proteos, Singapore, 138673, Singapore. .,Department of Biological Sciences, National University of Singapore, Singapore, 117543, Singapore. .,Key Laboratory for Major Obstetric Diseases of Guangdong Province, The Third Affiliated Hospital of Guangzhou Medical University, Guangzhou, 510150, China.
| |
Collapse
|
6
|
The role of nutrients in the pathogenesis and treatment of migraine headaches: Review. Biomed Pharmacother 2018; 102:317-325. [DOI: 10.1016/j.biopha.2018.03.059] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2018] [Revised: 03/09/2018] [Accepted: 03/11/2018] [Indexed: 12/28/2022] Open
|
7
|
Abstract
Nicotinamide adenine dinucleotide (NAD), the cell's hydrogen carrier for redox enzymes, is well known for its role in redox reactions. More recently, it has emerged as a signaling molecule. By modulating NAD+-sensing enzymes, NAD+ controls hundreds of key processes from energy metabolism to cell survival, rising and falling depending on food intake, exercise, and the time of day. NAD+ levels steadily decline with age, resulting in altered metabolism and increased disease susceptibility. Restoration of NAD+ levels in old or diseased animals can promote health and extend lifespan, prompting a search for safe and efficacious NAD-boosting molecules that hold the promise of increasing the body's resilience, not just to one disease, but to many, thereby extending healthy human lifespan.
Collapse
Affiliation(s)
- Luis Rajman
- Paul F. Glenn Center for the Biological Mechanisms of Aging, Department of Genetics, Harvard Medical School, Boston, MA 02115, USA
| | - Karolina Chwalek
- Paul F. Glenn Center for the Biological Mechanisms of Aging, Department of Genetics, Harvard Medical School, Boston, MA 02115, USA
| | - David A Sinclair
- Paul F. Glenn Center for the Biological Mechanisms of Aging, Department of Genetics, Harvard Medical School, Boston, MA 02115, USA; Laboratory for Ageing Research, Department of Pharmacology, School of Medical Sciences, The University of New South Wales, Sydney, NSW 2052, Australia.
| |
Collapse
|
8
|
The current landscape for the treatment of mitochondrial disorders. J Genet Genomics 2018; 45:71-77. [DOI: 10.1016/j.jgg.2017.11.008] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2017] [Revised: 10/29/2017] [Accepted: 11/18/2017] [Indexed: 12/14/2022]
|
9
|
Therapeutic strategies for mitochondrial disorders. Pediatr Neurol 2015; 52:302-13. [PMID: 25701186 DOI: 10.1016/j.pediatrneurol.2014.06.023] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/25/2014] [Revised: 06/14/2014] [Accepted: 06/19/2014] [Indexed: 12/31/2022]
Abstract
OBJECTIVES There is currently no curative therapy for mitochondrial disorders, although symptomatic measures can be highly effective and greatly improve the quality of life and outcome of these patients. This review highlights potential strategies for the therapeutic management of mitochondrial disorders. METHODS Data for this review were identified by searches of MEDLINE, Current Contents, using various relevant search terms. RESULTS Strategies to establish a therapeutic regimen aim to enhance respiratory chain function, eliminate noxious compounds, shift the heteroplasmy rate, alter mitochondrial dynamics, transfer cytoplasm, and promote gene therapy. Symptomatic measures rely on drugs (e.g., antiepileptics), avoidance of mitochondrion-toxic agents, substitution of blood cells, hemodialysis, invasive measures (such as a pacemaker), surgery (e.g., ptosis correction), physiotherapy, speech therapy, occupational therapy, dietary measures (e.g., ketogenic diet, anaplerotic diet), and the avoidance of mitochondrion-toxic agents (e.g., ozone). With the increasing awareness of mitochondrial disorders, the number of treatment studies is growing and its quality is improving. If high quality studies (high Jadad score) yield statistical significance for end points, a treatment is more reliable than with lower quality studies. CONCLUSIONS Despite the lack of a proven treatment for mitochondrial disorders, a nihilistic attitude toward treatment is not justified. A number of studies are seeking targeted therapies, and highly effective symptomatic measures are available.
Collapse
|
10
|
Analyses of the mitochondrial mutations in the Chinese patients with sporadic Creutzfeldt-Jakob disease. Eur J Hum Genet 2014; 23:86-91. [PMID: 24667788 DOI: 10.1038/ejhg.2014.52] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2013] [Revised: 02/18/2014] [Accepted: 02/19/2014] [Indexed: 01/27/2023] Open
Abstract
Pathogenic mitochondrial DNA (mtDNA) mutations leading to mitochondrial dysfunction can cause a variety of chronic diseases in central nervous system (CNS). However, the role of mtDNA mutations in sporadic Creutzfeldt-Jakob disease (sCJD) has still been unknown. In this study, we comparatively analyzed complete mtDNA sequences of 31 Chinese sCJD patients and 32 controls. Using MITOMASTER and PhyloTree, we characterized 520 variants in sCJD patients and 507 variants in control by haplogroup and allele frequencies. We classified the mtDNAs into 40 sub-haplogroups of 5 haplogroups, most of them being Asian-specific haplogroups. Haplogroup U, an European-specific haplogroups mtDNA, was found only in sCJD. The analysis to control region (CR) revealed a 31% increase in the frequency of mtDNA CR mutations in sCJD versus controls. In functional elements of the mtDNA CR, six CR mutations were in conserved sequence blocks I (CSBI) in sCJD, while only one in control (P<0.05). More mutants in transfer ribonucleic acid-Leu (tRNA-Leu) were detected in sCJD. The frequencies of two synonymous amino-acid changes, m.11467A>G, p.(=) in NADH dehydrogenase subunit 4 (ND4) and m.12372G>A, p.(=) in NADH dehydrogenase subunit 5 (ND5), in sCJD patients were higher than that of controls. Our study, for the first time, screened the variations of mtDNA of Chinese sCJD patients and identified some potential disease-related mutations for further investigations.
Collapse
|
11
|
Abstract
Migraine is the most frequent type of headache in children. In the 1980s, scientists first hypothesized a connection between migraine and mitochondrial (mt) disorders. More recent studies have suggested that at least some subtypes of migraine may be related to a mt defect. Different types of evidence support a relationship between mitochondria (mt) and migraine: (1) Biochemical evidence: Abnormal mt function translates into high intracellular penetration of Ca(2+), excessive production of free radicals, and deficient oxidative phosphorylation, which ultimately causes energy failure in neurons and astrocytes, thus triggering migraine mechanisms, including spreading depression. The mt markers of these events are low activity of superoxide dismutase, activation of cytochrome-c oxidase and nitric oxide, high levels of lactate and pyruvate, and low ratios of phosphocreatine-inorganic phosphate and N-acetylaspartate-choline. (2) Morphologic evidence: mt abnormalities have been shown in migraine sufferers, the most characteristic ones being direct observation in muscle biopsy of ragged red and cytochrome-c oxidase-negative fibers, accumulation of subsarcolemmal mt, and demonstration of giant mt with paracrystalline inclusions. (3) Genetic evidence: Recent studies have identified specific mutations responsible for migraine susceptibility. However, the investigation of the mtDNA mutations found in classic mt disorders (mt encephalomyopathy with lactic acidosis and stroke-like episodes, myoclonus epilepsy with ragged red fibers, Kearns-Sayre syndrome, and Leber hereditary optic neuropathy) has not demonstrated any association. Recently, 2 common mtDNA polymorphisms (16519C→T and 3010G→A) have been associated with pediatric cyclic vomiting syndrome and migraine. Also, POLG mutations (eg, p.T851 A, p.N468D, p.Y831C, p.G517V, and p.P163S) can cause disease through impaired replication of mtDNA, including migraine. Further studies to investigate the relationship between mtDNA and migraine will require very large sample sizes to obtain statistically significant results. (4) Therapeutic evidence: Several agents that have a positive effect on mt metabolism have shown to be effective in the treatment of migraines. The agents include riboflavin (B2), coenzyme Q10, magnesium, niacin, carnitine, topiramate, and lipoic acid. Further study is warranted to learn how mt interact with other factors to cause migraines. This will facilitate the development of new and more specific treatments that will reduce the frequency or severity or both of this disease.
Collapse
Affiliation(s)
- William R Yorns
- Section of Neurology, St. Christopher's Hospital for Children, Philadelphia, PA; Departments of Pediatrics and Neurology, Drexel University College of Medicine, Philadelphia, PA
| | - H Huntley Hardison
- Section of Neurology, St. Christopher's Hospital for Children, Philadelphia, PA; Departments of Pediatrics and Neurology, Drexel University College of Medicine, Philadelphia, PA.
| |
Collapse
|
12
|
Pfeffer G, Horvath R, Klopstock T, Mootha VK, Suomalainen A, Koene S, Hirano M, Zeviani M, Bindoff LA, Yu-Wai-Man P, Hanna M, Carelli V, McFarland R, Majamaa K, Turnbull DM, Smeitink J, Chinnery PF. New treatments for mitochondrial disease-no time to drop our standards. Nat Rev Neurol 2013; 9:474-81. [PMID: 23817350 PMCID: PMC4967498 DOI: 10.1038/nrneurol.2013.129] [Citation(s) in RCA: 123] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Mitochondrial dysfunction is a common cause of inherited multisystem disease that often involves the nervous system. Despite major advances in our understanding of the pathophysiology of mitochondrial diseases, clinical management of these conditions remains largely supportive. Using a systematic approach, we identified 1,039 publications on treatments for mitochondrial diseases, only 35 of which included observations on more than five patients. Reports of a positive outcome on the basis of a biomarker of unproven clinical significance were more common in nonrandomized and nonblinded studies, suggesting a publication bias toward positive but poorly executed studies. Although trial design is improving, there is a critical need to develop new biomarkers of mitochondrial disease. In this Perspectives article, we make recommendations for the design of future treatment trials in mitochondrial diseases. Patients and physicians should no longer rely on potentially biased data, with the associated costs and risks.
Collapse
Affiliation(s)
- Gerald Pfeffer
- Wellcome Trust Centre for Mitochondrial Research, Institute of Genetic Medicine, Ageing and Health, Newcastle University, Newcastle upon Tyne NE1 3BZ, UK
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
13
|
|
14
|
TAM DIAMOND, TAM MAJESTIC, MAYNARD KENNETHI. Nicotinamide Modulates Energy Utilization and Improves Functional Recovery from Ischemia in the In Vitro Rabbit Retina. Ann N Y Acad Sci 2008. [DOI: 10.1111/j.1749-6632.2005.tb00033.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
|
15
|
Scaglia F, Northrop JL. The mitochondrial myopathy encephalopathy, lactic acidosis with stroke-like episodes (MELAS) syndrome: a review of treatment options. CNS Drugs 2006; 20:443-64. [PMID: 16734497 DOI: 10.2165/00023210-200620060-00002] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Mitochondrial encephalomyopathies are a multisystemic group of disorders that are characterised by a wide range of biochemical and genetic mitochondrial defects and variable modes of inheritance. Among this group of disorders, the mitochondrial myopathy, encephalopathy, lactic acidosis with stroke-like episodes (MELAS) syndrome is one of the most frequently occurring, maternally inherited mitochondrial disorders. As the name implies, stroke-like episodes are the defining feature of the MELAS syndrome, often occurring before the age of 15 years. The clinical course of this disorder is highly variable, ranging from asymptomatic, with normal early development, to progressive muscle weakness, lactic acidosis, cognitive dysfunction, seizures, stroke-like episodes, encephalopathy and premature death. This syndrome is associated with a number of point mutations in the mitochondrial DNA, with over 80% of the mutations occurring in the dihydrouridine loop of the mitochondrial transfer RNA(Leu(UUR)) [tRNA(Leu)((UUR))] gene. The pathophysiology of the disease is not completely understood; however, several different mechanisms are proposed to contribute to this disease. These include decreased aminoacylation of mitochondrial tRNA, resulting in decreased mitochondrial protein synthesis; changes in calcium homeostasis; and alterations in nitric oxide metabolism. Currently, no consensus criteria exist for treating the MELAS syndrome or mitochondrial dysfunction in other diseases. Many of the therapeutic strategies used have been adopted as the result of isolated case reports or limited clinical studies that have included a heterogeneous population of patients with the MELAS syndrome, other defects in oxidative phosphorylation or lactic acidosis due to disorders of pyruvate metabolism. Current approaches to the treatment of the MELAS syndrome are based on the use of antioxidants, respiratory chain substrates and cofactors in the form of vitamins; however, no consistent benefits have been observed with these treatments.
Collapse
Affiliation(s)
- Fernando Scaglia
- Department of Molecular and Human Genetics, Baylor College of Medicine and Texas Children's Hospital, Houston, Texas 77030, USA.
| | | |
Collapse
|
16
|
Baker SK, Tarnopolsky MA. Targeting cellular energy production in neurological disorders. Expert Opin Investig Drugs 2005; 12:1655-79. [PMID: 14519086 DOI: 10.1517/13543784.12.10.1655] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
The concepts of energy dysregulation and oxidative stress and their complicated interdependence have rapidly evolved to assume primary importance in understanding the pathophysiology of numerous neurological disorders. Therefore, neuroprotective strategies addressing specific bioenergetic defects hold particular promise in the treatment of these conditions (i.e., amyotrophic lateral sclerosis, Huntington's disease, Parkinson's disease, Friedreich's ataxia, mitochondrial cytopathies and other neuromuscular diseases), all of which, to some extent, share 'the final common pathway' leading to cell death through either necrosis or apoptosis. Compounds such as creatine monohydrate and coenzyme Q(10) offer substantial neuroprotection against ischaemia, trauma, oxidative damage and neurotoxins. Miscellaneous agents, including alpha-lipoic acid, beta-OH-beta-methylbutyrate, riboflavin and nicotinamide, have also been shown to improve various metabolic parameters in brain and/or muscle. This review will highlight the biological function of each of the above mentioned compounds followed by a discussion of their utility in animal models and human neurological disease. The balance of this work will be comprised of discussions on the therapeutic applications of creatine and coenzyme Q(10).
Collapse
Affiliation(s)
- Steven K Baker
- Neurology and Rehabilitation, Room 4U4, Department of Medicine, McMaster University, Hamilton, Ontario, L8N 3Z5, Canada
| | | |
Collapse
|
17
|
Prousky J, Seely D. The treatment of migraines and tension-type headaches with intravenous and oral niacin (nicotinic acid): systematic review of the literature. Nutr J 2005; 4:3. [PMID: 15673472 PMCID: PMC548511 DOI: 10.1186/1475-2891-4-3] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2004] [Accepted: 01/26/2005] [Indexed: 12/03/2022] Open
Abstract
Background Migraine and tension-type headaches impose a tremendous economic drain upon the healthcare system. Intravenous and oral niacin has been employed in the treatment of acute and chronic migraine and tension-type headaches, but its use has not become part of contemporary medicine, nor have there been randomized controlled trials further assessing this novel treatment. We aimed to systematically review the evidence of using intravenous and/or oral niacin as a treatment for migraine headaches, tension-type headaches, and for headaches of other etiologic types. Methods We searched English and non-English language articles in the following databases: MEDLINE (1966–February 2004), AMED (1995–February 2004) and Alt HealthWatch (1990–February 2004). Results Nine articles were found to meet the inclusion criteria and were included in this systematic review. Hypothetical reasons for niacin's effectiveness include its vasodilatory properties, and its ability to improve mitochondrial energy metabolism. Important side effects of niacin include flushing, nausea and fainting. Conclusion Although niacin's mechanisms of action have not been substantiated from controlled clinical trials, this agent may have beneficial effects upon migraine and tension-type headaches. Adequately designed randomized trials are required to determine its clinical implications.
Collapse
Affiliation(s)
- Jonathan Prousky
- Department of Clinical Education, The Canadian College of Naturopathic Medicine, 1255 Sheppard Avenue East, Toronto, Ontario, M2K 1E2, Canada
| | - Dugald Seely
- Department of Research, The Canadian College of Naturopathic Medicine, 1255 Sheppard Avenue East, Toronto, Ontario, M2K 1E2, Canada
- Institute of Medical Science, University of Toronto, Toronto, Canada
| |
Collapse
|
18
|
Marriage B, Clandinin MT, Glerum DM. Nutritional cofactor treatment in mitochondrial disorders. JOURNAL OF THE AMERICAN DIETETIC ASSOCIATION 2003; 103:1029-38. [PMID: 12891154 DOI: 10.1016/s0002-8223(03)00476-0] [Citation(s) in RCA: 72] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Mitochondrial disorders are degenerative diseases characterized by a decrease in the ability of mitochondria to supply cellular energy requirements. Substantial progress has been made in defining the specific biochemical defects and underlying molecular mechanisms, but limited information is available about the development and evaluation of effective treatment approaches. The goal of nutritional cofactor therapy is to increase mitochondrial adenosine 5'-triphosphate production and slow or arrest the progression of clinical symptoms. Accumulation of toxic metabolites and reduction of electron transfer activity have prompted the use of antioxidants, electron transfer mediators (which bypass the defective site), and enzyme cofactors. Metabolic therapies that have been reported to produce a positive effect include Coenzyme Q(10) (ubiquinone); other antioxidants such as ascorbic acid, vitamin E, and lipoic acid; riboflavin; thiamin; niacin; vitamin K (phylloquinone and menadione); creatine; and carnitine. A literature review of the use of these supplements in mitochondrial disorders is presented.
Collapse
Affiliation(s)
- Barbara Marriage
- Department of Medical Genetics, University of Alberta, Edmonton, Alberta, Canada.
| | | | | |
Collapse
|
19
|
Affiliation(s)
- Yau-Huei Wei
- Department of Biochemistry, Center for Cellular and Molecular Biology, National Yang-Ming University, Taipei, Taiwan, Republic of China
| | | |
Collapse
|
20
|
Mahoney DJ, Parise G, Tarnopolsky MA. Nutritional and exercise-based therapies in the treatment of mitochondrial disease. Curr Opin Clin Nutr Metab Care 2002; 5:619-29. [PMID: 12394637 DOI: 10.1097/00075197-200211000-00004] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
PURPOSE OF REVIEW This review will critically summarize the nutritional and exercise-based interventions that have been used to treat mitochondrial disease, with a focus on the biochemical or molecular rationale for their use as well as recent advances in the field. RECENT FINDINGS Many nutritional-based treatment strategies have been used in an attempt to target energy impairment and its sequelae. Recently, coenzyme Q10, idebenone and triacylglycerol have been shown to bypass defective respiratory enzymes or scavenge free radicals, whereas creatine monohydrate has provided an alternative energy source. Thiamine has been used to decrease lactate levels and increase flux through aerobic metabolism, and riboflavin has been used as a precursor to complexes I and II. Several therapies employing various antioxidants in combination with other supplements have been effective at targeting several of the final common pathways of mitochondrial disease. Miscellaneous supplements, such as L-arginine and uridine, have also had recent success. However, although positive responses have been reported with these agents, many reports have shown no benefit, and there is widespread disparity in the literature. An alternative approach to treatment is exercise training. Both resistance and endurance exercise training have had positive outcomes in patients with mitochondrial disease, although several questions remain to be answered. SUMMARY There is no currently recognized treatment for mitochondrial disease. Future clinical trials are needed, as well as research into the potential for in-vitro screening of various compounds within affected cells from patients. Until this time, an accurate diagnosis will facilitate treatment on a case-by-case basis.
Collapse
Affiliation(s)
- Douglas J Mahoney
- Department of Medical Sciences, McMaster University, Hamilton, Ontario, Canada
| | | | | |
Collapse
|
21
|
Ames BN, Elson-Schwab I, Silver EA. High-dose vitamin therapy stimulates variant enzymes with decreased coenzyme binding affinity (increased K(m)): relevance to genetic disease and polymorphisms. Am J Clin Nutr 2002; 75:616-58. [PMID: 11916749 DOI: 10.1093/ajcn/75.4.616] [Citation(s) in RCA: 218] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
As many as one-third of mutations in a gene result in the corresponding enzyme having an increased Michaelis constant, or K(m), (decreased binding affinity) for a coenzyme, resulting in a lower rate of reaction. About 50 human genetic dis-eases due to defective enzymes can be remedied or ameliorated by the administration of high doses of the vitamin component of the corresponding coenzyme, which at least partially restores enzymatic activity. Several single-nucleotide polymorphisms, in which the variant amino acid reduces coenzyme binding and thus enzymatic activity, are likely to be remediable by raising cellular concentrations of the cofactor through high-dose vitamin therapy. Some examples include the alanine-to-valine substitution at codon 222 (Ala222-->Val) [DNA: C-to-T substitution at nucleo-tide 677 (677C-->T)] in methylenetetrahydrofolate reductase (NADPH) and the cofactor FAD (in relation to cardiovascular disease, migraines, and rages), the Pro187-->Ser (DNA: 609C-->T) mutation in NAD(P):quinone oxidoreductase 1 [NAD(P)H dehy-drogenase (quinone)] and FAD (in relation to cancer), the Ala44-->Gly (DNA: 131C-->G) mutation in glucose-6-phosphate 1-dehydrogenase and NADP (in relation to favism and hemolytic anemia), and the Glu487-->Lys mutation (present in one-half of Asians) in aldehyde dehydrogenase (NAD + ) and NAD (in relation to alcohol intolerance, Alzheimer disease, and cancer).
Collapse
Affiliation(s)
- Bruce N Ames
- Department of Molecular and Cellular Biology, University of California, Berkeley, USA.
| | | | | |
Collapse
|
22
|
Maynard KI, Ayoub IA, Shen CC. Delayed multidose treatment with nicotinamide extends the degree and duration of neuroprotection by reducing infarction and improving behavioral scores up to two weeks following transient focal cerebral ischemia in Wistar rats. Ann N Y Acad Sci 2001; 939:416-24. [PMID: 11462797 DOI: 10.1111/j.1749-6632.2001.tb03653.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A single, delayed dose of nicotinamide (NAm) was shown to be protective against focal cerebral ischemia in rats, but the protection was limited to three to seven days following stroke. The investigation reported here was conducted to examine if the use of multiple doses of NAm, administered after the onset of focal cerebral ischemia, would extend the duration of neuroprotection compared with a single dose treatment regimen. Male Wistar rats were subjected to transient focal cerebral ischemia by occluding the right middle cerebral artery (MCAo) for two hours. Following MCAo, motor and sensory behavioral tests were performed daily and the cerebral infarct volumes were measured at two weeks after sacrifice. Each animal was placed into one of four groups that received either normal saline alone (Group S), one (Group A), two (Group B), or three (Group C) doses of NAm (500 mg/kg). Each animal, therefore, received three treatments over two weeks, with the first dose administered intravenously two hours after the onset of MCAo. Single and multiple doses of NAm reduced the infarction (p < 0.01) and improved (p < 0.05) the neurologic sensory and motor behavior when compared with the saline-treated animals up to two weeks after stroke. Moreover, animals that received multiple doses of NAm recuperated full motor function not different from normal, preoperative motor behavior. Delayed treatment with NAm given as multiple doses, therefore, further enhances the extent and duration of neuroprotection by significantly reducing cerebral infarct volumes, improving neurologic behavioral scores, and confers a complete motor recovery up to two weeks from the onset of focal cerebral ischemia in Wistar rats.
Collapse
Affiliation(s)
- K I Maynard
- Neurophysiology Laboratory, Neurosurgical Service, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, USA.
| | | | | |
Collapse
|
23
|
Abstract
Extracellular NAD is degraded to pyridine and purine metabolites by different types of surface-located enzymes which are expressed differently on the plasmamembrane of various human cells and tissues. In a previous report, we demonstrated that NAD-glycohydrolase, nucleotide pyrophosphatase and 5'-nucleotidase are located on the outer surface of human skin fibroblasts. Nucleotide pyrophosphatase cleaves NAD to nicotinamide mononucleotide and AMP, and 5'-nucleotidase hydrolyses AMP to adenosine. Cells incubated with NAD, produce nicotinamide, nicotinamide mononucleotide, hypoxanthine and adenine. The absence of ADPribose and adenosine in the extracellular compartment could be due to further catabolism and/or uptake of these products. To clarify the fate of the purine moiety of exogenous NAD, we investigated uptake of the products of NAD hydrolysis using U-[(14)C]-adenine-NAD. ATP was found to be the main labeled intracellular product of exogenous NAD catabolism; ADP, AMP, inosine and adenosine were also detected but in small quantities. Addition of ADPribose or adenosine to the incubation medium decreased uptake of radioactive purine, which, on the contrary, was unaffected by addition of inosine. ADPribose strongly inhibited the activity of ecto-NAD-hydrolyzing enzymes, whereas adenosine did not. Radioactive uptake by purine drastically dropped in fibroblasts incubated with (14)C-NAD and dipyridamole, an inhibitor of adenosine transport. Partial inhibition of [(14)C]-NAD uptake observed in fibroblasts depleted of ATP showed that the transport system requires ATP to some extent. All these findings suggest that adenosine is the purine form taken up by cells, and this hypothesis was confirmed incubating cultured fibroblasts with (14)C-adenosine and analyzing nucleoside uptake and intracellular metabolism under different experimental conditions. Fibroblasts incubated with [(14)C]-adenosine yield the same radioactive products as with [(14)C]-NAD; the absence of inhibition of [(14)C]-adenosine uptake by ADPribose in the presence of alpha-beta methyleneADP, an inhibitor of 5' nucleotidase, demonstrates that ADPribose coming from NAD via NAD-glycohydrolase is finally catabolised to adenosine. These results confirm that adenosine is the NAD hydrolysis product incorporated by cells and further metabolized to ATP, and that adenosine transport is partially ATP dependent.
Collapse
Affiliation(s)
- M F Aleo
- Departament of Biomedical Science and Biotechnology, University of Brescia, via Valsabbina, 19, 25123 Brescia, Italy.
| | | | | | | | | | | |
Collapse
|
24
|
Tarnopolsky MA, Beal MF. Potential for creatine and other therapies targeting cellular energy dysfunction in neurological disorders. Ann Neurol 2001. [DOI: 10.1002/ana.1028] [Citation(s) in RCA: 164] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
|
25
|
Gillmor HA, Bolton CH, Hopton M, Moore WP, Perrett D, Bingley PJ, Gale EA. Measurement of nicotinamide and N-methyl-2-pyridone-5-carboxamide in plasma by high performance liquid chromatography. Biomed Chromatogr 1999; 13:360-2. [PMID: 10425028 DOI: 10.1002/(sici)1099-0801(199908)13:5<360::aid-bmc893>3.0.co;2-s] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
We describe a simple and reproducible method for simultaneous determination of nicotinamide and its major human biological metabolite N-methyl-2-pyridone-5-carboxamide (2pyr). Previous assays for nicotinamide in plasma and in urine have been complicated by the use of tedious extraction procedures or HPLC conditions which, although often allowing simultaneous analysis of several metabolites, add to the difficulties of performing multiple analyses. The procedure we describe is simple, using a rapid column clean-up of samples prior to injection, which can then be done using an autosampler. Both nicotinamide and its major metabolite 2pyr can be assayed rapidly, with good reproducibility, and at the same time.
Collapse
Affiliation(s)
- H A Gillmor
- Diabetes and Metabolism, Medical School Unit, Southmead Hospital, Bristol BS10 5NB, UK
| | | | | | | | | | | | | |
Collapse
|
26
|
Singh SK, Sarin D, Puliyel JM, Srivastav R, Gupta R, Kumar N, Mathews A. Melas syndrome. Indian J Pediatr 1999; 66:621-5. [PMID: 10798118 DOI: 10.1007/bf02727181] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
An 11 year old male presented with headache, vomiting and weakness of right side of body. One day after admission he developed right focal seizures. He had 5 previous episodes of stroke, the first at 11 months age. His milestones were normal upto the first episode but subsequent mile stones were delayed. His serum and CSF lactic acids were raised. Muscle biopsy showed ragged red fibres on modified Gomori-trichrome staining. His EEG, CT scan and MRI were normal this time. The child improved spontaneously after 7 days. His recovery time progressively became shorter with each episode of stroke. Maximum time for recovery was noted during first episode and least in current episode. This is the first report of Melas syndrome in Indian literature.
Collapse
Affiliation(s)
- S K Singh
- Department of Pediatrics, St. Stephen's Hospital, Tis Hazari, Delhi
| | | | | | | | | | | | | |
Collapse
|
27
|
Abstract
Mitochondrial diseases are a group of disorders characterized by morphological or functional defects of the mitochondria, the organelles producing most of our cellular energy. As the only extranuclear site carrying genetic information, the mitochondria add an important chapter into the inheritance patterns of genetic diseases. Mitochondrial DNA (mtDNA) is exclusively maternally inherited in humans, but a mitochondrial disorder may follow either maternal or Mendelian inheritance, depending on the site of the primary gene defect. After the initial finding of mtDNA mutations in rare ocular myopathies in 1988, an explosion in the amount of information on mitochondrial diseases has occurred. Because the mitochondria produce energy in all the tissues, symptoms resulting from mtDNA mutations may originate from any organ system, and the clinical spectrum of mitochondrial diseases has expanded to virtually all branches of medicine. Subgroups of several common diseases, such as diabetes, deafness and inherited cardiomyopathies, have been found to be caused by mtDNA mutations, and some mtDNA defects have been suggested to modify the outcome of diseases primarily caused by other factors, such as Parkinson's or Alzheimer's disease. Although no breakthroughs in the therapeutic trials on the devastating mitochondrial diseases have so far been achieved, detection of mtDNA mutations offers an accurate diagnosis and is a prerequisite for genetic counselling, being now accessible to most clinicians.
Collapse
Affiliation(s)
- A Suomalainen
- National Public Health Institute, Department of Human Molecular Genetics, Helsinki, Finland.
| |
Collapse
|