Loss of SIRT2 leads to axonal degeneration and locomotor disability associated with redox and energy imbalance

Sirtuin 2 (SIRT2) is a member of a family of NAD+ -dependent histone deacetylases (HDAC) that play diverse roles in cellular metabolism and especially for aging process. SIRT2 is located in the nucleus, cytoplasm, and mitochondria, is highly expressed in the central nervous system (CNS), and has been reported to regulate a variety of processes including oxidative stress, genome integrity, and myelination. However, little is known about the role of SIRT2 in the nervous system specifically during aging. Here, we show that middle-aged, 13-month-old mice lacking SIRT2 exhibit locomotor dysfunction due to axonal degeneration, which was not present in young SIRT2 mice. In addition, these Sirt2-/- mice exhibit mitochondrial depletion resulting in energy failure, and redox dyshomeostasis. Our results provide a novel link between SIRT2 and physiological aging impacting the axonal compartment of the central nervous system, while supporting a major role for SIRT2 in orchestrating its metabolic regulation. This underscores the value of SIRT2 as a therapeutic target in the most prevalent neurodegenerative diseases that undergo with axonal degeneration associated with redox and energetic dyshomeostasis.This study was supported by grants from the Spanish Institute for Health Carlos III and 'Fondo Europeo de Desarrollo Regional (FEDER), Union Europea, una manera de hacer Europa' [FIS PI11/01043, FIS PI14/00410], the Autonomous Government of Catalonia [SGR 2014SGR1430] to A.P., The Spanish Institute for Health Carlos III and 'Fondo Europeo de Desarrollo Regional (FEDER), Union Europea, una manera de hacer Europa' [Miguel Servet program CP11/00080, CPII16/00016, FIS PI15/00857] to S.F. and the Center for Biomedical Research on Rare Diseases (CIBERER) to M.R., and the Spanish Institute for Health Carlos III and FEDER funds from European Union ('A way to build Europe') [FIS grants PI14/01115, PI13/00584, and PI14/00328], Foundation La Marató de TV3 [345/C/2014], and the Autonomous Government of Catalonia [2014SGR168] to M.J., M.P.O., and R.P. The studies conducted at the Chromatin Biology Laboratory were supported by the Spanish Ministry of Economy and Competitiveness‐MINECO [SAF2011‐25860, SAF2014‐55964R] to A.V