The impact of mitochondrial protein acetylation status on neuronal function and vulnerability to neurological disorders is unknown. We found that the mitochondrial protein deacetylase SIRT3 mediates adaptive responses of neurons to bioenergetic, oxidative, and excitatory stress. Cortical neurons lacking SIRT3 exhibit heightened sensitivity to glutamate-induced calcium overload and excitotoxicity and oxidative and mitochondrial stress; AAV-mediated Sirt3 gene delivery restores neuronal stress resistance. In models relevant to Huntington's disease and epilepsy, Sirt3(-/-) mice exhibit increased vulnerability of striatal and hippocampal neurons, respectively. SIRT3 deficiency results in hyperacetylation of several mitochondrial proteins, including superoxide dismutase 2 and cyclophilin D. Running wheel exercise increases the expression of Sirt3 in hippocampal neurons, which is mediated by excitatory glutamatergic neurotransmission and is essential for mitochondrial protein acetylation homeostasis and the neuroprotective effects of running. Our findings suggest that SIRT3 plays pivotal roles in adaptive responses of neurons to physiological challenges and resistance to degeneration.

Agency
National Institute of Health (NIH)
Institute
National Institute on Aging (NIA)
Type
Investigator-Initiated Intramural Research Projects (ZIA)
Project #
1ZIAAG000326-01
Application #
9549280
Study Section
Project Start
Project End
Budget Start
Budget End
Support Year
1
Fiscal Year
2017
Total Cost
Indirect Cost
Name
Aging
Department
Type
DUNS #
City
State
Country
Zip Code
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Raefsky, Sophia M; Mattson, Mark P (2017) Adaptive responses of neuronal mitochondria to bioenergetic challenges: Roles in neuroplasticity and disease resistance. Free Radic Biol Med 102:203-216
Cheng, Aiwu; Yang, Ying; Zhou, Ye et al. (2016) Mitochondrial SIRT3 Mediates Adaptive Responses of Neurons to Exercise and Metabolic and Excitatory Challenges. Cell Metab 23:128-42