title: Metabolic profiling of CHO-AβPP695 cells revealed mitochondrial dysfunction prior to amyloid-β pathology and potential therapeutic effects of both PPARγ and PPARα Agonisms for Alzheimer's disease.
abstract: In this study, we performed gas chromatography time-of-flight mass spectrometry (GC-TOFMS)-based extracellular metabolic profiling on AβPP-transfected CHO cells (CHO-AβPP695) and its wildtype. Orthogonal partial least squares discriminant analysis (OPLS-DA) was then used to identify discriminant metabolites, which gave clues on the effects of AβPP transgene on cellular processes. To confirm the hypotheses generated based on the metabolic data, we performed biochemical assays to gather further evidence to support our findings. The OPLS-DA showed a robust differentiation following 24 h of incubation (Q2(cum) = 0.884) and 15 discriminant metabolites were identified. In contrast, extracellular Aβ42 was identified to increase significantly in CHO-AβPP695 only after incubation for 48 h. The observed 24-h metabolic fluxes were associated with increased mitochondrial AβPP and reduced mitochondrial viabilities, which occurred before extracellular Aβ accumulation. We also investigated the therapeutic potential of peroxisome proliferator-activated receptor gamma (PPARγ) agonists, namely rosiglitazone (RSG) and pioglitazone (PIO), by employing the same approach to characterize the metabolic profiles of CHO-AβPP695 treated with RSG and PIO, with or without their respective receptor blockers. Treatment with PIO was found to reduce the perturbation of the discriminant metabolites in CHO-AβPP695 to a larger extent than treatment with RSG. We also attributed the PIO effects on the lowering of Aβ42, and restoration of mitochondrial activity to PPARγ and PPARα agonism, respectively. Taken together, PIO was demonstrated to be therapeutically superior to RSG. Our findings provide further insights into early disease stages in this AβPP model, and support the advancement of PIO in AD therapy.
authors.affiliation: Department of Pharmacy, Faculty of Science, National University of Singapore, Republic of Singapore Computational and Systems Medicine, Department of Surgery and Cancer, Faculty of Medicine, Imperial College London, London, UK.
authors.forename: Kai Lun
authors.initials: KL
authors.lastname: Chang
authors.affiliation: Department of Pharmacy, Faculty of Science, National University of Singapore, Republic of Singapore.
authors.forename: Hai Ning
authors.initials: HN
authors.lastname: Pee
authors.affiliation: Department of Pharmacy, Faculty of Science, National University of Singapore, Republic of Singapore.
authors.forename: Wee Pin
authors.initials: WP
authors.lastname: Tan
authors.affiliation: Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Republic of Singapore.
authors.forename: Gavin S
authors.initials: GS
authors.lastname: Dawe
authors.affiliation: Computational and Systems Medicine, Department of Surgery and Cancer, Faculty of Medicine, Imperial College London, London, UK.
authors.forename: Elaine
authors.initials: E
authors.lastname: Holmes
authors.affiliation: Computational and Systems Medicine, Department of Surgery and Cancer, Faculty of Medicine, Imperial College London, London, UK.
authors.forename: Jeremy K
authors.initials: JK
authors.lastname: Nicholson
authors.affiliation: Department of Pharmacy, Faculty of Science, National University of Singapore, Republic of Singapore.
authors.forename: Eric C Y
authors.initials: EC
authors.lastname: Chan
authors.affiliation: Department of Pharmacy, Faculty of Science, National University of Singapore, Republic of Singapore.
authors.forename: Paul C
authors.initials: PC
authors.lastname: Ho
mesh_terms: D016229:Amyloid beta-Peptides; D016564:Amyloid beta-Protein Precursor / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D016466:CHO Cells; D002454:Cell Differentiation; D049109:Cell Proliferation / Q000187:drug effects; D003412:Cricetulus; D016002:Discriminant Analysis; D045604:Extracellular Fluid / Q000187:drug effects; D005786:Gene Expression Regulation / Q000187:drug effects / Q000235:genetics; D005947:Glucose / Q000378:metabolism; D006801:Humans; D051379:Mice; D015999:Multivariate Analysis; D047493:PPAR alpha / Q000819:agonists*; D047495:PPAR gamma / Q000819:agonists*; D010446:Peptide Fragments; D000077205:Pioglitazone; D000077154:Rosiglitazone; D045162:Thiazolidinediones / Q000494:pharmacology*; D013997:Time Factors; D014162:Transfection
chemical_list: D016229:Amyloid beta-Peptides; D016564:Amyloid beta-Protein Precursor; D047493:PPAR alpha; D047495:PPAR gamma; D010446:Peptide Fragments; D045162:Thiazolidinediones; C075222:amyloid beta-protein (1-42); D000077154:Rosiglitazone; D005947:Glucose; D000077205:Pioglitazone
keywords: Alzheimer's disease; amyloid beta-protein precursor (AβPP); metabolomics; metabonomics; mitochondria; pioglitazone; rosiglitazone