title: Mitochondrial trifunctional protein deficiency in human cultured fibroblasts: effects of bezafibrate.
abstract: Mitochondrial trifunctional protein (MTP) deficiency caused by HADHA or HADHB gene mutations exhibits substantial molecular, biochemical, and clinical heterogeneity and ranks among the more severe fatty acid oxidation (FAO) disorders, without pharmacological treatment. Since bezafibrate has been shown to potentially correct other FAO disorders in patient cells, we analyzed its effects in 26 MTP-deficient patient fibroblasts representing 16 genotypes. Overall, the patient cell lines exhibited variable, complex, biochemical profiles and pharmacological responses. HADHA-deficient fibroblasts showed markedly reduced alpha subunit protein levels together with decreased beta-subunit abundance, exhibited a -86 to -96% defect in LCHAD activity, and produced large amounts of C14 and C16 hydroxyacylcarnitines. In control fibroblasts, exposure to bezafibrate (400 μM for 48 h) increased the abundance of HADHA and HADHB mRNAs, immune-detectable alpha and beta subunit proteins, activities of LCHAD and LCKAT, and stimulated FAO capacities, clearly indicating that MTP is pharmacologically up-regulated by bezafibrate in human fibroblasts. In MTP-deficient patient fibroblasts, which were found markedly FAO-deficient, bezafibrate improved FAO capacities in six of 26 (23%) cases, including three cell lines heterozygous for the common c1528G > C mutation. Altogether, our results strongly suggest that, due to variable effects of HADHA and HADHB mutations on MTP abundance and residual activity, improvement of MTP deficiency in response to bezafibrate was achieved in a subset of responsive genotypes.
authors.affiliation: INSERM UMR-1124, Université Paris Descartes, Centre Universitaire des Saints Pères, 45 rue des Saints Pères, 75006, Paris, France.
authors.forename: Fatima
authors.initials: F
authors.lastname: Djouadi
authors.affiliation: INSERM UMR-1124, Université Paris Descartes, Centre Universitaire des Saints Pères, 45 rue des Saints Pères, 75006, Paris, France.
authors.forename: Florence
authors.initials: F
authors.lastname: Habarou
authors.affiliation: INSERM UMR-1124, Université Paris Descartes, Centre Universitaire des Saints Pères, 45 rue des Saints Pères, 75006, Paris, France.
authors.forename: Carole
authors.initials: C
authors.lastname: Le Bachelier
authors.affiliation: Laboratory Genetic Metabolic Diseases, Department of Clinical Chemistry and Pediatrics, Academic Medical Centre, University of Amsterdam, Meibergdreef 9, 1105 AZ, Amsterdam, The Netherlands.
authors.forename: Sacha
authors.initials: S
authors.lastname: Ferdinandusse
authors.affiliation: Centre de Référence des Maladies Héréditaires du Métabolisme, Service de Biochimie-Hormonologie, Hôpital Robert Debré, 48 bd Sérurier, 75019, Paris, France.
authors.forename: Dimitri
authors.initials: D
authors.lastname: Schlemmer
authors.affiliation: Centre de Référence des Maladies Héréditaires du Métabolisme, Service de Biochimie-Hormonologie, Hôpital Robert Debré, 48 bd Sérurier, 75019, Paris, France.
authors.forename: Jean François
authors.initials: JF
authors.lastname: Benoist
authors.affiliation: Service de Biochimie, Hôpital Bicêtre, 78 rue du Général Leclerc, 94270, Le Kremlin Bicêtre, France.
authors.forename: Audrey
authors.initials: A
authors.lastname: Boutron
authors.affiliation: Department of Biochemistry and Molecular Biology, University of Southern Denmark, Campusvej 55, DK-5230, Odense M, Denmark.
authors.forename: Brage S
authors.initials: BS
authors.lastname: Andresen
authors.affiliation: Wilhelmina Children's Hospital, University Medical Centre Utrecht, Lundlaan 6, 3584 EA, Utrecht, The Netherlands.
authors.forename: Gepke
authors.initials: G
authors.lastname: Visser
authors.affiliation: INSERM U781, Institut Imagine des Maladies Génétiques, Université Paris Descartes et Centre de Référence des Maladies Héréditaires du Métabolisme, Hôpital Necker, 149 rue de Sèvres, 75015, Paris, France.
authors.forename: Pascale
authors.initials: P
authors.lastname: de Lonlay
authors.affiliation: Department of Clinical Chemistry, Sheffield Children's Hospital, Western Bank, Sheffield, South Yorkshire, S10 2TH, UK.
authors.forename: Simon
authors.initials: S
authors.lastname: Olpin
authors.affiliation: Department of Pediatrics, Graduate School of Medicine, Gifu University, Yanagido 1-1, Gifu, 501-1194, Japan.
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Fukao
authors.affiliation: Department of Pediatrics, Shimane University School of Medicine, 89-1 Enya-Cho, Izumo, 693-8501, Japan.
authors.forename: Seiji
authors.initials: S
authors.lastname: Yamaguchi
authors.affiliation: Cincinnati Children's Hospital Medical Center, 3333 Burnet Avenue, Cincinnati, OH, 45229, USA.
authors.forename: Arnold W
authors.initials: AW
authors.lastname: Strauss
authors.affiliation: Laboratory Genetic Metabolic Diseases, Department of Clinical Chemistry and Pediatrics, Academic Medical Centre, University of Amsterdam, Meibergdreef 9, 1105 AZ, Amsterdam, The Netherlands.
authors.forename: Ronald J A
authors.initials: RJ
authors.lastname: Wanders
authors.affiliation: INSERM UMR-1124, Université Paris Descartes, Centre Universitaire des Saints Pères, 45 rue des Saints Pères, 75006, Paris, France. jean.bastin@inserm.fr.
authors.forename: Jean
authors.initials: J
authors.lastname: Bastin
mesh_terms: D001629:Bezafibrate / Q000494:pharmacology*; D009202:Cardiomyopathies / Q000188:drug therapy* / Q000235:genetics; D002460:Cell Line; D005347:Fibroblasts / Q000187:drug effects*; D005838:Genotype; D006801:Humans; D000960:Hypolipidemic Agents / Q000494:pharmacology*; D008052:Lipid Metabolism, Inborn Errors / Q000188:drug therapy* / Q000235:genetics; D017240:Mitochondrial Myopathies / Q000188:drug therapy* / Q000235:genetics; D063991:Mitochondrial Trifunctional Protein / Q000172:deficiency* / Q000235:genetics; D063992:Mitochondrial Trifunctional Protein, alpha Subunit / Q000172:deficiency* / Q000235:genetics; D063993:Mitochondrial Trifunctional Protein, beta Subunit / Q000172:deficiency* / Q000235:genetics; D009154:Mutation / Q000235:genetics; D009422:Nervous System Diseases / Q000188:drug therapy* / Q000235:genetics; D012206:Rhabdomyolysis / Q000188:drug therapy* / Q000235:genetics
chemical_list: D000960:Hypolipidemic Agents; C576205:HADHA protein, human; D063992:Mitochondrial Trifunctional Protein, alpha Subunit; C576206:HADHB protein, human; D063991:Mitochondrial Trifunctional Protein; D063993:Mitochondrial Trifunctional Protein, beta Subunit; D001629:Bezafibrate