374-OR: Exercise Training Decreases ß-Cell Senescence in Mice and Humans

Abstract

Increased β-cell senescence contributes to the development of type 2 diabetes (T2D). Exercise is critical in the treatment of T2D and can attenuate aging-associated cellular changes, but exercise effects on β-cell senescence are unknown. We tested the effects of treadmill running (1h/day for 10 days) on two insulin resistance models: high-fat diet and insulin receptor antagonist (S961). Exercise improved glucose responsiveness and decreased senescence markers (SA-βGal activity, p21Cip1 and p16Ink4a mRNA and protein levels). RNAseq from pancreatic islets of exercised mice revealed decreased expression of senescence effector genes and senescence associated secretory phenotype factors. Exercise increased AMPK activity in islets as assessed by alpha catalytic subunit phosphorylation. Islets from sedentary mice cultured for 2 days with serum from exercised mice showed decreased senescence, suggesting a circulatory factor was responsible for these effects. Pathway analysis of RNASeq revealed that exercise upregulated glucagon type ligand receptors. Glucagon treatment of mouse and human islets activated AMPK and decreased senescence in β-cells, an affect attenuated by an AMPK inhibitor (compound C). Exercised mice treated with a glucagon antagonist (adomeglivant) blocked AMPK phosphorylation and increased p21Cip1 and p16Ink4. Exercise increased nuclear translocation of the AMPK substrate NRF2 in mouse islets while downregulation of Nrf2 with siRNA in MIN6 cells increased transcription of p16Ink4a, suggesting a potential mechanism linking exercise, AMPK activation and downregulation of β-cell senescence. Treatment of human donor islets with serum obtained pre- and post-exercise training for 10 weeks in people with T2D showed that training activated AMPK and decreased senescence markers. These findings demonstrate that exercise training decreases β-cell senescence and suggest that this important response to exercise occurs through circulating factors mediating an AMPK-dependent pathway. Disclosure P.Carapeto: None. J.Kahng: None. A.T.Alves wagner: None. R.J.W.Middelbeek: Research Support; Novo Nordisk. M.F.Hirshman: Stock/Shareholder; Abbott, AbbVie Inc., Amgen Inc., Colgate-Palmolive, Eli Lilly and Company, Medtronic. G.A.Rutter: Consultant; Sun Pharmaceutical Industries Ltd. L.Goodyear: None. C.Aguayo-mazzucato: None. Funding Joslin Diabetes Center (to C.A-M.); Richard and Susan Smith Family Foundation; Coordenação de Aperfeiçoamento de Pessoal de Nível Superior-Brasil (001)