title: Metabolic alterations induced by sucrose intake and Alzheimer's disease promote similar brain mitochondrial abnormalities.
abstract: Evidence shows that diabetes increases the risk of developing Alzheimer's disease (AD). Many efforts have been done to elucidate the mechanisms linking diabetes and AD. To demonstrate that mitochondria may represent a functional link between both pathologies, we compared the effects of AD and sucrose-induced metabolic alterations on mouse brain mitochondrial bioenergetics and oxidative status. For this purpose, brain mitochondria were isolated from wild-type (WT), triple transgenic AD (3xTg-AD), and WT mice fed 20% sucrose-sweetened water for 7 months. Polarography, spectrophotometry, fluorimetry, high-performance liquid chromatography, and electron microscopy were used to evaluate mitochondrial function, oxidative status, and ultrastructure. Western blotting was performed to determine the AD pathogenic protein levels. Sucrose intake caused metabolic alterations like those found in type 2 diabetes. Mitochondria from 3xTg-AD and sucrose-treated WT mice presented a similar impairment of the respiratory chain and phosphorylation system, decreased capacity to accumulate calcium, ultrastructural abnormalities, and oxidative imbalance. Interestingly, sucrose-treated WT mice presented a significant increase in amyloid β protein levels, a hallmark of AD. These results show that in mice, the metabolic alterations associated to diabetes contribute to the development of AD-like pathologic features.
authors.affiliation: Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal.
authors.forename: Cristina
authors.initials: C
authors.lastname: Carvalho
authors.forename: Susana
authors.initials: S
authors.lastname: Cardoso
authors.forename: Sónia C
authors.initials: SC
authors.lastname: Correia
authors.forename: Renato X
authors.initials: RX
authors.lastname: Santos
authors.forename: Maria S
authors.initials: MS
authors.lastname: Santos
authors.forename: Inês
authors.initials: I
authors.lastname: Baldeiras
authors.forename: Catarina R
authors.initials: CR
authors.lastname: Oliveira
authors.forename: Paula I
authors.initials: PI
authors.lastname: Moreira
mesh_terms: D000544:Alzheimer Disease / Q000235:genetics / Q000473:pathology*; D000818:Animals; D000975:Antioxidants; D001921:Brain / Q000166:cytology* / Q000187:drug effects / Q000473:pathology; D002118:Calcium / Q000378:metabolism / Q000494:pharmacology; D048909:Diabetes Complications / Q000235:genetics / Q000473:pathology; D003924:Diabetes Mellitus, Type 2 / Q000150:complications / Q000473:pathology; D004579:Electron Transport; D004734:Energy Metabolism; D005786:Gene Expression Regulation; D005978:Glutathione / Q000378:metabolism / Q000494:pharmacology; D008297:Male; D051379:Mice; D008822:Mice, Transgenic; D008928:Mitochondria / Q000187:drug effects* / Q000473:pathology*; D033681:Mitochondrial Membrane Transport Proteins / Q000187:drug effects; D000083162:Mitochondrial Permeability Transition Pore; D018384:Oxidative Stress; D010766:Phosphorylation; D011897:Random Allocation; D013395:Sucrose / Q000009:adverse effects*; D014810:Vitamin E / Q000378:metabolism / Q000494:pharmacology
chemical_list: D000975:Antioxidants; D033681:Mitochondrial Membrane Transport Proteins; D000083162:Mitochondrial Permeability Transition Pore; D014810:Vitamin E; D013395:Sucrose; D005978:Glutathione; D002118:Calcium