alexa Decreased expression of Hsp27 and Hsp70 in transformed lymphoblastoid cells from patients with spinocerebellar ataxia type 7.


Journal of Alzheimers Disease & Parkinsonism

Author(s): Tsai HF, Lin SJ, Li C, Hsieh M

Abstract Share this page

Abstract Spinocerebellar ataxia type 7 (SCA7) is caused by an expansion of unstable CAG repeats within the coding region of the novel gene, ataxin-7, on chromosome 3. This disease is also associated with an accumulation of abnormal proteins, including expanded polyglutamine-containing proteins, molecular chaperones, and the ubiquitin-proteasome system. In this study, two SCA7 lymphoblastoid cell lines (LCLs) with 100 and 41 polyglutamine repeats were utilized to examine the effects of polyglutamine expansion on heat shock proteins. Interestingly, under basal conditions, Western blot and immunocytochemical analysis showed a significant decrease of Hsp27 and Hsp70 protein expression in cells containing expanded ataxin-7, as compared with that of the normal LCL. On the other hand, the protein levels of Hsp60 and Hsp90 were not significantly altered in the mutant LCLs. Results from semi-quantitative RT-PCR indicated that the differences in Hsp70 protein levels were due to transcriptional defects while the reduction of Hsp27 in the mutant cells was not caused by transcriptional defects. Our results further demonstrated that despite of defective protein expression of Hsp27 and Hsp70, a normal heat shock response was observed in lymphoblastoid cells expressing mutant ataxin-7. Taken together, our results indicated that expanded ataxin-7 that leads to neurodegeneration significantly impaired the expression of Hsp27 and Hsp70 protein, which may be, at least in part, responsible for the toxicity of mutant ataxin-7 proteins and ultimately resulted in an increase of stress-induced cell death. This article was published in Biochem Biophys Res Commun and referenced in Journal of Alzheimers Disease & Parkinsonism

Relevant Expert PPTs

Relevant Speaker PPTs

Recommended Conferences

Relevant Topics

Peer Reviewed Journals
Make the best use of Scientific Research and information from our 700 + peer reviewed, Open Access Journals
International Conferences 2017-18
Meet Inspiring Speakers and Experts at our 3000+ Global Annual Meetings

Contact Us

© 2008-2017 OMICS International - Open Access Publisher. Best viewed in Mozilla Firefox | Google Chrome | Above IE 7.0 version