title: Bezafibrate upregulates carnitine palmitoyltransferase II expression and promotes mitochondrial energy crisis dissipation in fibroblasts of patients with influenza-associated encephalopathy.
abstract: Influenza-associated encephalopathy (IAE) is characterized by persistently high fever, febrile convulsions, severe brain edema and high mortality. We reported previously that a large proportion of patients with disabling or fatal IAE exhibit a thermolabile phenotype of compound variants for [1055T>G/F352C] and [1102G>A/V368I] of carnitine palmitoyltransferase II (CPT II) and mitochondrial energy crisis during high fever. In the present study, we studied the effect of bezafibrate, a hypolipidemic pan-agonist of peroxisome proliferator-activated receptor (PPAR), on CPT II expression and mitochondrial energy metabolism in fibroblasts of IAE patients and wild type (WT) fibroblasts from a healthy volunteer at 37°C and 41°C. Although heat stress markedly upregulated CPT II, CPT IA and PPAR-δ mRNA expression levels, CPT II activity, β-oxidation and ATP levels in WT and IAE fibroblasts at 41°C were paradoxically downregulated probably due to the thermal instability of the corresponding enzymes. Bezafibrate significantly enhanced the expression levels of the above mRNAs and cellular functions of these enzymes in fibroblasts at 37°C. Bezafibrate-induced increase in CPT II activity also tended to restore the downregulated ATP levels, though moderately, and improved mitochondrial membrane potential even at 41°C to the levels at 37°C in fibroblasts of IAE patients. L-carnitine, a substrate of CPT II, boosted the effects of bezafibrate on cellular ATP levels in WT and IAE fibroblasts, even in severe IAE fibroblasts with thermolabile compound variations of F352C+V368I at 37°C and 41°C. The results suggest the potential usefulness of bezafibrate for the treatment of IAE.
authors.affiliation: Division of Enzyme Chemistry, Institute for Enzyme Research, The University of Tokushima, Kuramoto-cho 3-18-15, Tokushima 770-8503, Japan.
authors.forename: Min
authors.initials: M
authors.lastname: Yao
authors.forename: Dengbin
authors.initials: D
authors.lastname: Yao
authors.forename: Miyoko
authors.initials: M
authors.lastname: Yamaguchi
authors.forename: Junji
authors.initials: J
authors.lastname: Chida
authors.forename: Dengfu
authors.initials: D
authors.lastname: Yao
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Kido
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism; D001483:Base Sequence; D001629:Bezafibrate / Q000494:pharmacology* / Q000627:therapeutic use; D015153:Blotting, Western; D001928:Brain Diseases, Metabolic / Q000188:drug therapy* / Q000209:etiology / Q000378:metabolism; D002331:Carnitine / Q000378:metabolism; D002334:Carnitine O-Palmitoyltransferase / Q000235:genetics / Q000378:metabolism*; D017931:DNA Primers / Q000235:genetics; D004734:Energy Metabolism / Q000187:drug effects*; D005347:Fibroblasts / Q000378:metabolism; D005786:Gene Expression Regulation / Q000187:drug effects*; D023281:Genomics / Q000379:methods; D006358:Hot Temperature; D006801:Humans; D007251:Influenza, Human / Q000150:complications*; D007564:Japan; D053078:Membrane Potential, Mitochondrial / Q000187:drug effects / Q000502:physiology; D008856:Microscopy, Fluorescence; D008928:Mitochondria / Q000187:drug effects* / Q000378:metabolism; D008969:Molecular Sequence Data; D047492:Peroxisome Proliferator-Activated Receptors / Q000819:agonists; D012333:RNA, Messenger / Q000378:metabolism*; D060888:Real-Time Polymerase Chain Reaction; D017422:Sequence Analysis, DNA; D013997:Time Factors
chemical_list: D017931:DNA Primers; D047492:Peroxisome Proliferator-Activated Receptors; D012333:RNA, Messenger; D000255:Adenosine Triphosphate; D002334:Carnitine O-Palmitoyltransferase; D002331:Carnitine; D001629:Bezafibrate