[17-AAG, ameliorates polyglutamine-mediated motor neuron degeneration]
>> Nat Med. 2005 Sep 11; [Epub ahead of print]
17-AAG, an Hsp90 inhibitor, ameliorates polyglutamine-mediated motor neuron degeneration.
Waza M, Adachi H, Katsuno M, Minamiyama M, Sang C, Tanaka F, Inukai A, Doyu M, Sobue G.
[1] Department of Neurology, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya 466-8550, Japan. [2] These authors contributed equally to this work.
Heat-shock protein 90 (Hsp90) functions as part of a multichaperone complex that folds, activates and assembles its client proteins. Androgen receptor (AR), a pathogenic gene product in spinal and bulbar muscular atrophy (SBMA), is one of the Hsp90 client proteins. We examined the therapeutic effects of 17-allylamino-17-demethoxygeldanamycin (17-AAG), a potent Hsp90 inhibitor, and its ability to degrade polyglutamine-expanded mutant AR. Administration of 17-AAG markedly ameliorated motor impairments in the SBMA transgenic mouse model without detectable toxicity, by reducing amounts of monomeric and aggregated mutant AR. The mutant AR showed a higher affinity for Hsp90-p23 and preferentially formed an Hsp90 chaperone complex as compared to wild-type AR; mutant AR was preferentially degraded in the presence of 17-AAG in both cells and transgenic mice as compared to wild-type AR. 17-AAG also mildly induced Hsp70 and Hsp40. 17-AAG would thus provide a new therapeutic approach to SBMA and probably to other related neurodegenerative diseases.<<
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