SIRT2 regulates insulin sensitivity in insulin resistant neuronal cells.

Insulin resistance in brain is well-associated with pathophysiology of deficits in whole-body energy metabolism, neurodegenerative diseases etc. Among the seven sirtuins, SIRT2 is the major deacetylase expressed in brain. Inhibition of SIRT2 confers neuroprotection in case of Parkinson's disease (PD) and Huntington's disease (HD). However, the role of this sirtuin in neuronal insulin resistance is not known. In this study, we report the role of SIRT2 in regulating insulin-sensitivity in neuronal cells in vitro. Using approaches like pharmacological inhibition of SIRT2, siRNA mediated SIRT2 knockdown and over-expression of wild-type and catalytically-mutated SIRT2, we observed that downregulation of SIRT2 ameliorated the reduced activity of AKT and increased insulin-stimulated glucose uptake in insulin resistant neuro-2a cells. The data was supported by over expression of catalytically-inactive SIRT2 in insulin-resistant human SH-SY5Y neuronal cells. Data highlights a crucial role of SIRT2 in regulation of neuronal insulin sensitivity under insulin resistant condition.