VPS13C deficiency alters ER-lysosome and mitochondria-lysosome contact sites in iPSC-derived dopaminergic neurons. (A and B) Representative live-cell confocal images showing lysosome-ER contact sites in control (A) and VPS13C KD (B) dopaminergic neurons expressing LAMP1-mGFP (green) and Halo-KDEL (gray) (scale bar: 10 µm, inset: 1 µm). (C) Quantification of the percentage of stable ER-lysosome contacts (≥10 s) (N = 4, from n = 15 cells). (D and E) Quantification and histogram distribution of the minimum duration of ER-lysosome contacts (N = 4, from n = 15 cells). (F) Quantification of the percentage of cell area occupied by ER (N = 4, from n = 15 cells). (G) Representative time-lapse confocal images showing mitochondria-lysosome contact sites in iPSC-derived dopaminergic neurons expressing LAMP1-mGFP (green) and mAppleTOMM20 (gray). Tethered mitochondria with lysosomes (yellow arrow) untether at 59 and 56 s, respectively, in control conditions (white arrow) but remain tethered in VPS13C KD neurons (yellow arrow) until 153 and 135 s, respectively (scale bar: 1 µm). (H) Quantification of the percentage of stable mitochondria-lysosome contacts (≥10 s) (N = 4, from n = 15 cells). (I) Quantification of the minimum contact duration of mitochondria-lysosome (M-L) contacts (N = 4, from n = 15 cells). Data represented as mean ± SEM; unpaired two-tailed t test (C, D, F, H, and I); ns: not significant (D and F), **P < 0.01 (C and H), ****P < 0.0001 (I).