HTTQ94 expression sensitizes neuronal cells and other cell types to ferroptosis. (A) Western blot analysis for HTTQ94 from HTTQ94 tet-on HT-22 cells treated with 0.5 μg/mL doxycycline for 2, 4, 8, and 16 h. (B) HTTQ94 tet-on HT-22 cells were preincubated with 0.5 μg/mL doxycycline for 4 h and then treated with 1 μM erastin for 12 h with/without 2 μM Ferr-1. (C) Representative phase-contrast images of cell death, related to B. (D) Western blot analysis for mutant HTT fragment (HTTQ94) and normal HTT fragment (HTTQ19) expression in the tet-on H1299 cells treated with 0.5 μg/mL doxycycline (tet) for 16 h. (E) Cell death assay. Control, HTTQ94, and HTTQ19 fragment tet-on H1299 cells preincubated with 0.5 μg/mL doxycycline for 16 h were treated with 30 μM erastin for 48 h with/without 2 μM Ferr-1. Cell deaths were calculated from three replicates. Data shown in B and E are the means ± SD. P-values were derived from two-tailed unpaired t-test. (***) P ≤ 0.001, (n.s.) P > 0.05.