Research Paper Volume 16, Issue 20 pp 12977—13011
Werner syndrome RECQ helicase participates in and directs maintenance of the protein complexes of constitutive heterochromatin in proliferating human cells
Figure 3. WRN, HDAC2, and HP1α associations are reduced in replicatively senescing cells. (A) Normal human dermal fibroblasts were passaged to derive early and late passage cultures, which were cryopreserved and subsequently used in the same experiment. (B) SA β-gal levels in young (Y) and old (O) fibroblasts were quantified via fluorescent detection and microscopy. Cytoplasmic MFI was measured per digital image, normalized to the number of cells in each image determined by DAPI counterstaining, and plotted. (C, D) Quantitation of H3K9me3, WRN, HDAC2, and HP1α MFIs in young vs. old fibroblasts determined by IF in situ. (E) Quantitations of HDAC2/HP1α, WRN/HP1α, and WRN/HDAC2 PLA signals in young vs. old fibroblasts. Graphs in C, D, and E represent two independent experiments each. Crossbars in graphs are distribution means.