Affiliations: [a] Departamento de Bioquímica, Universidade Federal de Santa Catarina, Florianópolis, Brazil
| [b]
Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal
| [c] Faculty of Pharmacy, University of Coimbra, Coimbra, Portugal
| [d]
Department of Physiological Sciences, Institute of Biological Sciences, University of Brasília, Brasília, Brazil
| [e] Department of Biomedical and Clinical Sciences, Linköping University, Linköping, Sweden
Correspondence:
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Correspondence to: Ana Ledo, Faculty of Pharmacy, University of Coimbra, Health Science Campus, Azinhaga de Santa Comba, 3000-548 Coimbra, Portugal. E-mail: [email protected]; Andreza Fabro de Bem, Department of Physiological Sciences, Institute of Biological Sciences, University of Brasília, Brasília, Brazil. E-mail: [email protected].
Abstract: Background:Ample evidence from clinical and pre-clinical studies suggests mid-life hypercholesterolemia as a risk factor for developing Alzheimer’s disease (AD) at a later age. Hypercholesterolemia induced by dietary habits can lead to vascular perturbations that increase the risk of developing sporadic AD. Objective:To investigate the effects of a high fat/cholesterol diet (HFCD) as a risk factor for AD by using a rodent model of AD and its correspondent control (healthy animals). Methods:We compared the effect of a HFCD in normal mice (non-transgenic mice, NTg) and the triple transgenic mouse model of AD (3xTgAD). We evaluated cognitive performance in relation to changes in oxidative metabolism and neuron-derived nitric oxide (•NO) concentration dynamics in hippocampal slices as well as histochemical staining of markers of the neurovascular unit. Results:In NTg, the HFCD produced only moderate hypercholesterolemia but significant decline in spatial memory was observed. A tendency for decrease in •NO production was accompanied by compromised mitochondrial function with decrease in spare respiratory capacity. In 3xTgAD mice, a robust increase in plasma cholesterol levels with the HFCD did not worsen cognitive performance but did induce compromise of mitochondrial function and significantly decreased •NO production. We found increased staining of biomarkers for astrocyte endfeet and endothelial cells in 3xTgAD hippocampi, which was further increased by the HFCD. Conclusion:A short term (8 weeks) intervention with HFCD can produce an AD-like phenotype even in the absence of overt systemic hypercholesterolemia and highlights mitochondrial dysfunction as a link between hypercholesterolemia and sporadic AD.
Keywords: Alzheimer’s disease, high fat/cholesterol diet, hippocampus, spare respiratory capacity
