Extended Data Fig. 6 |. Telomere dysfunction activates autophagy.

a, Metaphase chromosomes of post-senescent HMECs (PD22) expressing non-targeting control shRNA or shRNA against TRF1 or TRF2. Metaphases were prepared from cells at day 6 post-transduction. Mock represents non-transduced cells. DAPI staining in blue, telomeres in green and γH2AX in red. Arrowheads indicate chromosome fusion events. Two independent experiments were performed. b, Left, scatter plot showing the mean number of telomeric γH2AX foci per metaphase at day 6 post-transduction. Right, scatter plot showing the number of fused chromosomes per metaphase at day 6 post-transduction. Centre line, mean. n shows number of metaphases analysed. Two independent experiments were performed. One-way ANOVA; ns, not significant, ∗∗∗P < 0.001. c, LC3-II and P62 turnover assays. HMECs and IMR90^E6E7 cells expressing non-targeting control shRNA or shRNA targeting TRF2 at day 6 post-transduction were treated for bafilomycin A1 (50 nM for 24 h) or MG132 (10 μM for 24 h). Top, experimental timeline. Bottom, immunoblotting of HMECs and IMR90^E6E7 cells at day 6 posttransduction with GAPDH as loading control. One experiment was performed. For gel source data, see Supplementary Fig. 1.