Publication Date:
2015-10-10
Description:
Huntington's disease (HD) is an autosomal-dominant degenerative disease caused by a cytosine-adenine-guanine trinucleotide expansion in the Huntingtin ( htt ) gene. The most vulnerable brain areas to mutant HTT-evoked toxicity are the striatum and cortex. In spite of the extensive efforts that have been devoted to the characterization of HD pathogenesis, no disease-modifying therapy for HD is currently available. The A 2A adenosine receptor (A 2A R) is widely distributed in the brain, with the highest level observed in the striatum. We previously reported that stimulation of the A 2A R triggers an anti-apoptotic effect in a rat neuron-like cell line (PC12). Using a transgenic mouse model (R6/2) of HD, we demonstrated that A 2A R-selective agonists effectively ameliorate several major symptoms of HD. In the present study, we show that human iPSCs can be successfully induced to differentiate into DARPP32-positive, GABAergic neurons which express the A 2A R in a similar manner to striatal medium spiny neurons. When compared with those derived from control subjects (CON-iPSCs), these HD-iPSC-derived neurons exhibited a higher DNA damage response, based on the observed expression of H2AX and elevated oxidative stress. This is a critical observation, because oxidative damage and abnormal DNA damage/repair have been reported in HD patients. Most importantly, stimulation of the A 2A R using selective agonists reduced DNA damage and oxidative stress-induced apoptosis in HD-iPSC-derived neurons through a cAMP/PKA-dependent pathway. These findings support our hypothesis that human neurons derived from diseased iPSCs might serve as an important platform to investigate the beneficial effects and underlying mechanisms of A 2A R drugs.
Print ISSN:
0964-6906
Electronic ISSN:
1460-2083
Topics:
Biology
,
Medicine
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