Fig. 4. SUV39H1 depletion in human cells correlates with reduced levels of H3K9me3 at TARDBP promoter and with a corresponding increase in TDP-43 protein.

A Western Blot showing the SUV39H1 and TDP-43 protein levels in extracts from WT or SUV39H1 KO cells. Numbers below represent band quantification normalized on internal loading control (actin; average of 6 experiments). B qRT-PCR analysis on the hTARDBP promoter immunoprecipitated with an anti-H3K9me3 in chromatin extracts from WT or SUV39H1 KO cells. Enrichment is shown as a percentage of input DNA and normalized on the GADPH gene used as control. Error bars represent SEM of three independent experiments (n = 3, 3 biological replicates) **p < 0.01 calculated by Mann-Whitney t-test. C Western blots showing the expression levels of TDP-43 in wild type (WT) or SUV39H1 KO HaCaT Keratinocytes after (+) or not (−) treatment with H₂O₂ (200 mM) for 2 h (2 h). H₂O₂ treatment reduces TDP-43 levels in WT but not in SUV39H1-KO cells. Numbers below represent band quantification normalized on internal loading control (actin; average of 3 biological repetitions).