HDAC1 and 2 are co-localized with myofibroblasts in the infarcted and non-infarcted myocardium in CHF. Cross-sections of sham and 6w CHF hearts were stained for HDAC1 (A-E) or HDAC2 (F-J) and α-SMA. DAPI (Blue) is used to stain nuclei. α-SMA was expressed in vessels in sham LV and RV and did not co-localize with HDAC1 (A, E) and HDAC2 (F-J) staining. HDAC1 staining was co- localized with α-SMA + cells in LV (B) and RV (E) and scar (C) in CHF. White arrows indicate co-localized cells. Similarly, HDAC2 was co-localized with α-SMA + cells in LV (G) and RV (J) and scar (H) in CHF. Scale bars: 150 μm. CHF, congestive heart failure; HDAC, Histone Deacetylase; CHF, congestive heart failure; SMA, α-Smooth muscle actin.