Aims/hypothesis: We recently found that activation of the type III histone deacetylase sirtuin 1 suppresses T cell immune responses. Here we sought to determine the therapeutic potential of the sirtuin 1 activator resveratrol in the treatment of diabetes in the NOD mouse model of type 1 diabetes and the mechanisms underlying such potential.
Methods: NOD mice were fed or subcutaneously injected with resveratrol and evaluated for development of diabetes. Splenocytes from resveratrol-treated and control mice were analysed by gene array. The altered expression of inflammatory genes induced by resveratrol was validated and the role of changed gene expression in prevention of diabetes was determined.
Results: Resveratrol administration potently prevented and treated type 1 diabetes in NOD mice. Gene array analysis indicated a dramatic decrease in expression of Ccr6, which encodes chemokine (C-C motif) receptor (CCR) 6, in the splenocytes from resveratrol-treated mice. CCR6 abundance on IL-17-producing cells and CD11b(+)F4/80(hi) macrophages was inhibited by resveratrol treatment. Interestingly, CCR6(+) IL-17-producing cells and CD11b(+)F4/80(hi) macrophages accumulated in the spleens and pancreatic lymph nodes, but their presence in the pancreas was reduced, suggesting that resveratrol blocks their migration from peripheral lymphoid organs to the pancreas. Indeed, the migration of splenocytes toward media containing chemokine (C-C motif) ligand 20 (CCL20) was impaired by resveratrol treatment. CCL20 peptides, which block CCR6 binding to CCL20, inhibited development of type 1 diabetes.
Conclusions/interpretation: Inhibition of CCR6-mediated migration of inflammatory cells by resveratrol may provide a powerful approach for treatment of type 1 diabetes and possibly of other inflammatory diseases.