title: Plasma metabolic profile delineates roles for neurodegeneration, pro-inflammatory damage and mitochondrial dysfunction in the FMR1 premutation.
abstract: Carriers of premutation CGG expansions in the fragile X mental retardation 1 (FMR1) gene are at higher risk of developing a late-onset neurodegenerative disorder named Fragile X-associated tremor ataxia syndrome (FXTAS). Given that mitochondrial dysfunction has been identified in fibroblasts, PBMC and brain samples from carriers as well as in animal models of the premutation and that mitochondria are at the center of intermediary metabolism, the aim of the present study was to provide a complete view of the metabolic pattern by uncovering plasma metabolic perturbations in premutation carriers. To this end, metabolic profiles were evaluated in plasma from 23 premutation individuals and 16 age- and sex-matched controls. Among the affected pathways, mitochondrial dysfunction was associated with a Warburg-like shift with increases in lactate levels and altered Krebs' intermediates, neurotransmitters, markers of neurodegeneration and increases in oxidative stress-mediated damage to biomolecules. The number of CGG repeats correlated with a subset of plasma metabolites, which are implicated not only in mitochondrial disorders but also in other neurological diseases, such as Parkinson's, Alzheimer's and Huntington's diseases. For the first time, the identified pathways shed light on disease mechanisms contributing to morbidity of the premutation, with the potential of assessing metabolites in longitudinal studies as indicators of morbidity or disease progression, especially at the early preclinical stages.
authors.affiliation: Department of Molecular Biosciences, School of Veterinary Medicine, University of California Davis, 1089 Veterinary Medicine Dr., VetMed 3B #3009, Davis, CA 95616, USA Medical Investigation of Neurodevelopmental Disorders (MIND) Institute, University of California Davis, Davis, CA 95817, USA.
authors.forename: Cecilia
authors.initials: C
authors.lastname: Giulivi
authors.affiliation: Department of Molecular Biosciences, School of Veterinary Medicine, University of California Davis, 1089 Veterinary Medicine Dr., VetMed 3B #3009, Davis, CA 95616, USA.
authors.forename: Eleonora
authors.initials: E
authors.lastname: Napoli
authors.affiliation: Medical Investigation of Neurodevelopmental Disorders (MIND) Institute, University of California Davis, Davis, CA 95817, USA Department of Biochemistry and Molecular Medicine, School of Medicine, University of California Davis, Davis, CA, USA.
authors.forename: Flora
authors.initials: F
authors.lastname: Tassone
authors.affiliation: Department of Molecular Biosciences, School of Veterinary Medicine, University of California Davis, 1089 Veterinary Medicine Dr., VetMed 3B #3009, Davis, CA 95616, USA.
authors.forename: Julian
authors.initials: J
authors.lastname: Halmai
authors.affiliation: Medical Investigation of Neurodevelopmental Disorders (MIND) Institute, University of California Davis, Davis, CA 95817, USA Department of Pediatrics, University of California Davis Medical Center, Sacramento, CA 95817, USA.
authors.forename: Randi
authors.initials: R
authors.lastname: Hagerman
mesh_terms: D000328:Adult; D005260:Female; D051860:Fragile X Messenger Ribonucleoprotein 1 / Q000235:genetics*; D006801:Humans; D007249:Inflammation / Q000097:blood* / Q000378:metabolism*; D007521:Isocitrate Dehydrogenase / Q000378:metabolism; D008297:Male; D055432:Metabolomics / Q000379:methods; D008875:Middle Aged; D008928:Mitochondria / Q000378:metabolism* / Q000473:pathology*; D008954:Models, Biological; D019636:Neurodegenerative Diseases / Q000097:blood* / Q000378:metabolism*; D011768:Pyruvate Dehydrogenase Complex / Q000378:metabolism
chemical_list: D051860:Fragile X Messenger Ribonucleoprotein 1; D007521:Isocitrate Dehydrogenase; D011768:Pyruvate Dehydrogenase Complex; C497683:FMR1 protein, human
keywords: fragile X; metabolomics; mitochondrial dysfunction; neurodegeneration; trinucleotide repeat disorders