Figure 2.

Tight Regulation of cardiac autophagy—inherent mechanisms and pathways. (A, B) In healthy individuals, tightly regulated activity of mTOR and AMP kinase (AMPK) maintains normal proteostasis, however, factors that accelerate cardiovascular aging also dysregulates mTOR and AMPK activity and autophagy. (C) Longevity treatments induce autophagy in the heart via initial inhibition of mTOR and activation of AMPK. However, building blocks such as amino acids generated by autophagy can reactivate mTOR, whereas an increase in microRNAs that inhibit various component proteins of autophagy machinery (shown in Figure 1) can inhibit further progression of autophagy in the heart.