Figure 4.

Consequences of sustained mTOR activation. In the liver, muscle and fat tissues, sustained mTOR activation causes systemic IR. In the beta cells, mTOR initially increases beta-cell function, causes beta-cell hypertrophy and adaptation to IR. Beta-cell hyperfunction and IR eventually may cause beta-cell failure and type II diabetes. In the retina and the kidney, hyperactivation of mTOR may lead to retinopathy and nephropathy, respectively