Aging-dependent changes in tissue function are associated with the development of metabolic diseases. However, the molecular connections linking aging, obesity and diabetes remain unclear. Lamin A, lamin C and progerin, products of the Lmna gene, have antagonistic functions on energy metabolism and lifespan. Lamin C, albeit promoting obesity, increases lifespan suggesting that this isoform is crucial for maintaining healthy conditions under metabolic stresses. Since β-cell loss during obesity or aging leads to diabetes, we investigated the contribution of lamin C to β-cell function in physiopathological conditions. We demonstrate that aged lamin C-only expressing mice (Lmna ^LCS/LCS ) become obese but remain glucose tolerant, due to adaptive mechanisms including increased β-cell mass and insulin secretion. Triggering diabetes in young mice revealed that Lmna ^LCS/LCS animals normalize their fasting glycemia by both increasing insulin secretion and regenerating β-cells. Genome-wide analyses combined to functional analyses revealed an increase of mitochondrial biogenesis and global translational rate in Lmna ^LCS/LCS islets, two major processes involved in insulin secretion. Altogether, our results demonstrate for the first time, that the sole expression of lamin C protects from glucose intolerance through a β-cell adaptive transcriptional program during metabolic stresses highlighting Lmna gene processing as a new therapeutic target for diabetes treatment.

© 2020 by the American Diabetes Association.