Dataset Information

Mouse models of spinocerebellar ataxia type 3 (Machado-Joseph disease).

ABSTRACT: Machado-Joseph disease, also called spinocerebellar ataxia type 3 (MJD/SCA3), is a hereditary and neurodegenerative movement disorder caused by ataxin-3 with a pathological polyglutamine stretch (mutant ataxin-3). Seven transgenic mouse models expressing full-length human mutant ataxin-3 throughout the brain have been generated and are compared in this review. They vary in the corresponding transgenic DNA constructs with differences that include the encoded human ataxin-3 isoform(s), number of polyglutamine(s), and the promoter driving transgene expression. The behaviors/signs evaluated in most models are body weight, balance/coordination, locomotor activity, gait, limb position, and age at death. The pathology analyzed includes presence of neuronal intranuclear inclusions, and qualitative evidence of neurodegeneration. On the basis of striking similarities in age-range of detection and number of behavior/sign abnormalities and pathology, all but 1 mouse model could be readily sorted into groups with high, intermediate, and low severity of phenotype. Stereological analysis of neurodegeneration was performed in the same brain regions in 2 mouse models; the corresponding results are consistent with the classification of the mouse models.

SUBMITTER: Colomer Gould VF

PROVIDER: S-EPMC3337014 | biostudies-literature | 2012 Apr

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Mouse models of spinocerebellar ataxia type 3 (Machado-Joseph disease).

Colomer Gould Veronica F VF

Neurotherapeutics : the journal of the American Society for Experimental NeuroTherapeutics 20120401 2

Machado-Joseph disease, also called spinocerebellar ataxia type 3 (MJD/SCA3), is a hereditary and neurodegenerative movement disorder caused by ataxin-3 with a pathological polyglutamine stretch (mutant ataxin-3). Seven transgenic mouse models expressing full-length human mutant ataxin-3 throughout the brain have been generated and are compared in this review. They vary in the corresponding transgenic DNA constructs with differences that include the encoded human ataxin-3 isoform(s), number of p ...[more]

PMID: 22451301

Similar Datasets

Project description:ObjectivesSpinocerebellar ataxia type 3/Machado-Joseph disease (SCA3/MJD) is a polyglutamine disorder with no current disease-modifying treatment. Conformational changes in mutant ataxin-3 trigger different pathogenic cascades, including reactive oxygen species (ROS) generation; however, the clinical relevance of oxidative stress elements as peripheral biomarkers of SCA3/MJD remains unknown. We aimed to evaluate ROS production and antioxidant defense capacity in symptomatic and presymptomatic SCA3/MJD individuals and correlate these markers with clinical and molecular data with the goal of assessing their properties as disease biomarkers.MethodsMolecularly confirmed SCA3/MJD carriers and controls were included in an exploratory case-control study. Serum ROS, measured by 2',7'-dichlorofluorescein diacetate (DCFH-DA) as well as superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) antioxidant enzyme activities, levels were assessed.ResultsFifty-eight early/moderate stage symptomatic SCA3/MJD, 12 presymptomatic SCA3/MJD, and 47 control individuals were assessed. The DCFH-DA levels in the symptomatic group were 152.82?nmol/mg of protein [95% confidence interval (CI), 82.57-223.08, p?<?0.001] higher than in the control and 243.80?nmol/mg of protein (95% CI, 130.64-356.96, p?<?0.001) higher than in the presymptomatic group. The SOD activity in the symptomatic group was 3?U/mg of protein (95% CI, 0.015-6.00, p?=?0.048) lower than in the presymptomatic group. The GSH-Px activity in the symptomatic group was 13.96?U/mg of protein (95% CI, 5.90-22.03, p?<?0.001) lower than in the control group and 20.52?U/mg of protein (95% CI, 6.79-34.24, p?<?0.001) lower than in the presymptomatic group and was inversely correlated with the neurological examination score for spinocerebellar ataxias (R?=?-0.309, p?=?0.049).ConclusionEarly/moderate stage SCA3/MJD patients presented a decreased antioxidant capacity and increased ROS generation. GSH-Px activity was the most promising oxidative stress disease biomarker in SCA3/MJD. Further longitudinal studies are necessary to identify both the roles of redox parameters in SCA3/MJD pathophysiology and as surrogate outcomes for clinical trials.

Project description:Blood-brain barrier (BBB) disruption is a common feature in neurodegenerative diseases. However, BBB integrity has not been assessed in spinocerebellar ataxias (SCAs) such as Machado-Joseph disease/SCA type 3 (MJD/SCA3), a genetic disorder, triggered by polyglutamine-expanded ataxin-3. To investigate that, BBB integrity was evaluated in a transgenic mouse model of MJD and in human post-mortem brain tissues.Firstly, we investigated the BBB permeability in MJD mice by: i) assessing the extravasation of the Evans blue (EB) dye and blood-borne proteins (e.g fibrinogen) in the cerebellum by immunofluorescence, and ii) in vivo Dynamic Contrast Enhanced-Magnetic Resonance Imaging (DCE-MRI). The presence of ataxin-3 aggregates in brain blood vessels and the levels of tight junction (TJ)-associated proteins were also explored by immunofluorescence and western blotting. Human brain samples were used to confirm BBB permeability by evaluating fibrinogen extravasation, co-localization of ataxin-3 aggregates with brain blood vessels and neuroinflammation.In the cerebellum of the mouse model of MJD, there was a 5-fold increase in EB accumulation when compared to age-matched controls. Moreover, vascular permeability displayed a 13-fold increase demonstrated by DCE-MRI. These results were validated by the 2-fold increase in fibrinogen extravasation in transgenic animals comparing to controls. Interestingly, mutant ataxin-3 aggregates were detected in cerebellar blood vessels of transgenic mice, accompanied by alterations of TJ-associated proteins in cerebellar endothelial cells, namely a 29% decrease in claudin-5 oligomers and a 10-fold increase in an occludin cleavage fragment. These results were validated in post-mortem brain samples from MJD patients as we detected fibrinogen extravasation across BBB, the presence of ataxin-3 aggregates in blood vessels and associated microgliosis.Altogether, our results prove BBB impairment in MJD/SCA3. These findings contribute for a better understanding of the disease mechanisms and opens the opportunity to treat MJD with medicinal products that in normal conditions would not cross the BBB.

Dataset Information

Mouse models of spinocerebellar ataxia type 3 (Machado-Joseph disease).

Publications

Mouse models of spinocerebellar ataxia type 3 (Machado-Joseph disease).

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets