Fig. 1
From: Computational modeling of the effects of autophagy on amyloid-β peptide levels
Schematic diagram of the model system. The rounded rectangles with white borders illustrate four compartments: 1) intracellular protein, 2) autophagosome, 3) autolysosome, and 4) extracellular amyloid-β (Aβ) peptide. CS1, CS2, and CS3 denote the concentrations of intracellular resident protein S1, abnormal protein S2, and amyloid-β peptide S3, respectively. Cgi and Cli represent the concentrations of autophagosomes and autolysosomes, respectively, from Si (i = 1, 2, 3). CES3 stands for the extracellular Aβ concentration. Rgi, Rli, Rhi, and Rdi are the specific rates of autophagosome formation, autolysosome formation, intralysosomal hydrolysis, and non-autophagic degradation, respectively, for Si (i = 1, 2, and 3 again). Rsec and Rclr denote respectively the rates of Aβ secretion and clearance. The differential equations describe variations of the concentrations of proteins (Eqs. (1)–(4)), autophagosomes (Eq. (5)), autolysosomes (Eq. (6)), amino acids (Eq. (7)), and ATP (Eq. (8))