The Hippo kinase LATS2 impairs pancreatic ß-cell survival in diabetes through the mTORC1-autophagy axis.

ABSTRACT

Diabetes results from a decline in functional pancreatic ß-cells, but the molecular mechanisms underlying the pathological ß-cell failure are poorly understood. Here we report that large-tumor suppressor 2 (LATS2), a core component of the Hippo signaling pathway, is activated under diabetic conditions and induces ß-cell apoptosis and impaired function. LATS2 deficiency in ß-cells and primary isolated human islets as well as ß-cell specific LATS2 ablation in mice improves ß-cell viability, insulin secretion and ß-cell mass and ameliorates diabetes development. LATS2 activates mechanistic target of rapamycin complex 1 (mTORC1), a physiological suppressor of autophagy, in ß-cells and genetic and pharmacological inhibition of mTORC1 counteracts the pro-apoptotic action of activated LATS2. We further show a direct interplay between Hippo and autophagy, in which LATS2 is an autophagy substrate. On the other hand, LATS2 regulates ß-cell apoptosis triggered by impaired autophagy suggesting an existence of a stress-sensitive multicomponent cellular loop coordinating ß-cell compensation and survival. Our data reveal an important role for LATS2 in pancreatic ß-cell turnover and suggest LATS2 as a potential therapeutic target to improve pancreatic ß-cell survival and function in diabetes.