Figure 3.

Endogenous α-synuclein is degraded in lysosomes by chaperone-mediated autophagy (CMA) in SH-SY5Y cells. (A,B) Levels of endogenous α-synuclein were determined in SH-SY5Y cells treated with NH₄Cl for 9.5 h. Immunoblots for the indicated proteins are shown in (A) and quantification of α-synuclein levels is shown in (B; mean ± SEM, n = 3, **p < 0.01 vs. control). (C–H) Levels of endogenous α-synuclein were determined in SH-SY5Y cells treated with Chloroquine diphosphate (CQ), 3-methyladenine (3-MA) and lactacystin respectively for 24 h. Immunoblots for the indicated proteins are shown in (C,E,G), and quantifications of α-synuclein levels are shown in (D,F,H) respectively (mean ± SEM, n = 3, **p < 0.01 vs. control). (I–K) Levels of endogenous α-synuclein were determined in lysosome-associated membrane protein type-2 (LAMP2) knockdown SH-SY5Y cells. Immunoblots for the indicated proteins are shown in (I), and the quantifications of α-synuclein and LAMP2A levels are shown in (J,K) respectively (mean ± SEM, n = 3, ***p < 0.001 vs. control, ^###p < 0.001 vs. scramble). (L–N) Levels of endogenous α-synuclein were determined in LAMP1 knockdown SH-SY5Y cells. Immunoblots for the indicated proteins are shown in (L), and the quantifications of α-synuclein and LAMP1 levels are shown in (M,N) respectively (mean ± SEM, n = 3, ***p < 0.001 vs. control, ^###p < 0.001 vs. scramble).