1. In vivo/Ex Vivo EPR Investigation of the Brain Redox Status and Blood--Brain Barrier Integrity in the 5xFAD Mouse Model of Alzheimer's Disease
- Author
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Ana Popović-Bijelić, Ana Vesković, Selma Kanazir, Aleksandra Pavićević, Đura Nakarada, Bogomir Bolka Prokić, Miloš Mojović, and Milka Perovic
- Subjects
0303 health sciences ,Chemistry ,Neurodegeneration ,Mitochondrion ,medicine.disease ,Blood–brain barrier ,medicine.disease_cause ,law.invention ,Cell biology ,03 medical and health sciences ,0302 clinical medicine ,medicine.anatomical_structure ,Neurology ,In vivo ,law ,medicine ,Neurology (clinical) ,Cognitive decline ,Electron paramagnetic resonance ,030217 neurology & neurosurgery ,Oxidative stress ,Ex vivo ,030304 developmental biology - Abstract
Background: Alzheimer’s disease (AD) is the most common neurodegenerative disorder characterized by cognitive decline and total brain atrophy. Despite the substantial scientific effort, the pathological mechanisms underlying neurodegeneration in AD are currently unknown. In most studies, amyloid β peptide has been considered the key pathological change in AD. However, numerous Aβ-targeting treatments have failed in clinical trials. This implies the need to shift the research focus from Aβ to other pathological features of the disease. Objective: The aim of this study was to examine the interplay between mitochondrial dysfunction, oxidative stress and blood-brain barrier (BBB) disruption in AD pathology, using a novel approach that involves the application of electron paramagnetic resonance (EPR) spectroscopy. Methods: In vivo and ex vivo EPR spectroscopy using two spin probes (aminoxyl radicals) exhibiting different cell-membrane and BBB permeability were employed to assess BBB integrity and brain tissue redox status in the 5xFAD mouse model of AD. In vivo spin probe reduction decay was analyzed using a two-compartment pharmacokinetic model. Furthermore, 15 K EPR spectroscopy was employed to investigate the brain metal content. Results: This study has revealed an altered brain redox state, BBB breakdown, as well as ROS-mediated damage to mitochondrial iron-sulfur clusters, and up-regulation of MnSOD in the 5xFAD model. Conclusion: The EPR spin probes were shown to be excellent in vivo reporters of the 5xFAD neuronal tissue redox state, as well as the BBB integrity, indicating the importance of in vivo EPR spectroscopy application in preclinical studies of neurodegenerative diseases.
- Published
- 2020