Staff Publications

Staff Publications

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    'Staff publications' is the digital repository of Wageningen University & Research

    'Staff publications' contains references to publications authored by Wageningen University staff from 1976 onward.

    Publications authored by the staff of the Research Institutes are available from 1995 onwards.

    Full text documents are added when available. The database is updated daily and currently holds about 240,000 items, of which 72,000 in open access.

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Record number 426005
Title A role for the peroxisomal 3-ketoacyl-CoA thiolase B enzyme in the control of PPAR alpha-mediated upregulation of SREBP-2 target genes in the liver
Author(s) Fidaleo, M.; Arnauld, S.; Clemencet, M.C.; Chevillard, G.; Royer, M.C.; Bruycker, M. de; Wanders, R.J.A.; Athias, A.; Gresti, J.; Clouet, P.; Degrace, P.; Kersten, A.H.; Espeel, M.; Latruffe, N.; Nicolas-Frances, V.; Mandard, S.
Source Biochimie 93 (2011)5. - ISSN 0300-9084 - p. 876 - 891.
Department(s) Chair Nutrition Metabolism and Genomics
Publication type Refereed Article in a scientific journal
Publication year 2011
Keyword(s) acyl-coa oxidase - proliferator-activated receptors - element-binding proteins - fatty-acid oxidation - beta-oxidation - rat-liver - cholesterol-synthesis - 3-oxoacyl-coa thiolase - neuronal migration - zellweger-syndrome
Abstract Peroxisomal 3-ketoacyl-CoA thiolase B (Thb) catalyzes the final step in the peroxisomal beta-oxidation of straight-chain acyl-CoAs and is under the transcription control of the nuclear hormone receptor PPAR alpha. PPARa binds to and is activated by the synthetic compound Wy14,643 (Wy). Here, we show that the magnitude of Wy-mediated induction of peroxisomal beta-oxidation of radiolabeled (1-(14)C) palmitate was significantly reduced in mice deficient for Thb. In contrast, mitochondrial beta-oxidation was unaltered in Thb(-1-) mice. Given that Wy-treatment induced Acox1 and MFP-1/-2 activity at a similar level in both genotypes, we concluded that the thiolase step alone was responsible for the reduced peroxisomal beta-oxidation of fatty acids. Electron microscopic analysis and cytochemical localization of catalase indicated that peroxisome proliferation in the liver after Wy-treatment was normal in Thb(-/-) mice. Intriguingly, micro-array analysis revealed that mRNA levels of genes encoding cholesterol biosynthesis enzymes were upregulated by Wy in Wild-Type (WT) mice but not in Thb(-1-) mice, which was confirmed at the protein level for the selected genes. The non-induction of genes encoding cholesterol biosynthesis enzymes by Wy in Thb(-1-) mice appeared to be unrelated to defective SREBP-2 or PPARa signaling. No difference was observed in the plasma lathosterol/cholesterol ratio (a marker for de novo cholesterol biosynthesis) between Wy-treated WT and Thb(-1-) mice, suggesting functional compensation. Overall, we conclude that ThA and SCPx/SCP2 thiolases cannot fully compensate for the absence of ThB. In addition, our data indicate that ThB is involved in the regulation of genes encoding cholesterol biosynthesis enzymes in the liver, suggesting that the peroxisome could be a promising candidate for the correction of cholesterol imbalance in dyslipidemia.
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