ubiquinone and Spinocerebellar-Ataxias

Spinocerebellar ataxia type 2 (SCA2) is a rare neurodegenerative disorder caused by a CAG repeat expansion in the ataxin-2 gene. We show increased oxidative stress, abnormalities in the antioxidant system, changes in complexes involved in oxidative phosphorylation and changes in mitochondrial morphology in SCA2 patient fibroblasts compared to controls, and we show that treatment with CoQ10 can partially reverse these changes. Together, our results suggest that oxidative stress and mitochondrial dysfunction may be contributory factors to the pathophysiology of SCA2 and that therapeutic strategies involving manipulation of the antioxidant system could prove to be of clinical benefit.

Topics: Adolescent; Adult; Aged; Cells, Cultured; Female; Fibroblasts; Humans; Male; Middle Aged; Mitochondria; Oxidative Stress; Spinocerebellar Ataxias; Ubiquinone; Vitamins; Young Adult

Spinocerebellar ataxia type 1 (SCA1), due to an unstable polyglutamine expansion within the ubiquitously expressed Ataxin-1 protein, leads to the premature degeneration of Purkinje cells (PCs), decreasing motor coordination and causing death within 10-15 years of diagnosis. Currently, there are no therapies available to slow down disease progression. As secondary cellular impairments contributing to SCA1 progression are poorly understood, here, we focused on identifying those processes by performing a PC specific proteome profiling of Sca1(154Q/2Q) mice at a symptomatic stage. Mass spectrometry analysis revealed prominent alterations in mitochondrial proteins. Immunohistochemical and serial block-face scanning electron microscopy analyses confirmed that PCs underwent age-dependent alterations in mitochondrial morphology. Moreover, colorimetric assays demonstrated impairment of the electron transport chain complexes (ETC) and decrease in ATPase activity. Subsequently, we examined whether the mitochondria-targeted antioxidant MitoQ could restore mitochondrial dysfunction and prevent SCA1-associated pathology in Sca1(154Q/2Q) mice. MitoQ treatment both presymptomatically and when symptoms were evident ameliorated mitochondrial morphology and restored the activities of the ETC complexes. Notably, MitoQ slowed down the appearance of SCA1-linked neuropathology such as lack of motor coordination as well as prevented oxidative stress-induced DNA damage and PC loss. Our work identifies a central role for mitochondria in PC degeneration in SCA1 and provides evidence for the supportive use of mitochondria-targeted therapeutics in slowing down disease progression.

Topics: Animals; Antioxidants; Disease Progression; DNA Damage; DNA, Mitochondrial; Drug Evaluation, Preclinical; Mice, Inbred C57BL; Mitochondria; Organophosphorus Compounds; Oxidative Stress; Proteome; Spinocerebellar Ataxias; Ubiquinone

The aim of this study was to investigate the association between drug exposure and disease severity in SCA types 1, 2, 3 and 6. The Clinical Research Consortium for Spinocerebellar Ataxias (CRC-SCA) enrolled 319 participants with SCA1, 2, 3, and 6 from 12 medical centers in the United States and repeatedly measured clinical severity by the Scale for Assessment and Rating of Ataxia (SARA), the Unified Huntington's Disease Rating Scale part IV (UHDRS-IV), and the 9-item Patient Health Questionnaire during July 2009 to May 2012. We employed generalized estimating equations in regression models to study the longitudinal effects of coenzyme Q10 (CoQ10), statin, and vitamin E on clinical severity of ataxia after adjusting for age, sex, and pathological CAG repeat number. Cross-sectionally, exposure to CoQ10 was associated with lower SARA and higher UHDRS-IV scores in SCA1 and 3. No association was found between statins, vitamin E, and clinical outcome. Longitudinally, CoQ10, statins, and vitamin E did not change the rates of clinical deterioration indexed by SARA and UHDRS-IV scores within 2 years. CoQ10 is associated with better clinical outcome in SCA1 and 3. These drug exposures did not appear to influence clinical progression within 2 years. Further studies are warranted to confirm the association.

Topics: Adult; Age of Onset; Aged; Disease Progression; Female; Humans; Huntington Disease; Male; Middle Aged; Severity of Illness Index; Spinocerebellar Ataxias; Surveys and Questionnaires; Treatment Outcome; Ubiquinone