Fig. 3: Regulation of autophagy.
From: Mechanism of neuroprotection by trehalose: controversy surrounding autophagy induction
a Distinguishing between autophagosomes and autolysosomes. mRFP-GFP tandem fluorescent-tagged LC3 (tfLC3) fluoresces both GFP and RFP signals (yellow) before it is delivered to lysosomes. GFP in tfLC3 loses its fluorescence in the acidic and degradative lysosomal environment (red). Autophagy induction increases autophagosomes (yellow) and autolysosomes (red) together because the autophagic flux to lysosomes is not disturbed. Blocking fusion of autophagosomes and lysosomes, however, would increase the number of autophagosomes (yellow) only. b Autophagy modulating factors. Autophagy is initiated through inhibition of mTORC1 complex and activation of Class III PI3K complex. 3-methyladenine (3-MA) and Wortmannin prevent autophagy through inhibition of mTORC1 complex. Trehalose may activate autophagy through PI3K. BafA1 and trehalose could both inhibit fusions of autophagosomes and lysosomes, thus blocking final stage of autophagy
