Figure 1.

Tissue from patients with IPF has increased acetylation of MnSOD^K68, a known SIRT3 deacetylase target, which is localized to AT2 cells. A) Explanted lungs from patients with end-stage IPF were evaluated via IHC by using Abs that were targeted to a negative control IgG (fibrotic lung) and Ac-MnSOD^K68 from normal controls and fibrotic lungs. Shown is a representative panel of 2 normal and 3 fibrotic lungs (for the remainder, please see Supplemental Fig. 1). B) Dual immunofluorescence (IF) staining was used to colocalize expression of acetylated MnSOD^K68 (green fluorescence) and SFTPC (red fluorescence, used as a marker for AT2 cells). C) Semiquantitative analysis, measured by per-cell fluorescence intensity units as described in Materials and Methods, was used to compare AcMnSOD^K68 expression in AT2 cells of fibrotic (n = 110) and normal control (n = 121) lungs. Bars shown indicate means ± sem. *P < 0.05 vs. normal AT2 cells.