Figure 5.

Mitochondrial DNA is elevated in the lungs and plasma of patients with idiopathic pulmonary fibrosis (IPF). (A) Immunohistochemistry-based detection of TOM20 in IPF lung tissues (relative to control samples) revealed strong detection in fibrotic regions of lung in cells that also expressed α-smooth muscle actin (α-SMA). Top left: Normal lung stained with TOM20 shows detection in macrophages (brown). Top right: IPF lung stained with TOM20 shows detection in fibrotic regions (brown). Images are counterstained with hematoxylin, and scale bar is 50 μm. Bottom left: Combined immunofluorescence for α-SMA (red) and TOM20 (green) on IPF lung tissue. Slides are counterstained with 4′,6-diamidino-2-phenylindole (blue nuclear stain), and images include a 50-μm scale bar. Bottom right: Enlargement of the boxed area shows codetection of TOM20 and α-SMA in spindle-shaped cells with the appearance of fibroblasts. (B) Relative to control lung tissue, there were a significantly higher percentage of TOM20-positive cells expressing α-SMA in the IPF lung. Data are presented as mean (±SEM) percentage of TOM20 cells that also express α-SMA. (C) Relative to bronchoalveolar lavage (BAL) samples obtained from subjects without parenchymal lung disease (left), the median concentration of MT-ATP6 was significantly increased in BAL samples obtained from IPF subjects (right). Data are presented graphically as log base 10 of the raw values of MT-ATP6 copies per microliter of BAL with median value and interquartile range. A graph including the raw values is presented in Figure E5A. (D) Relative to plasma specimens obtained from aged-matched control subjects (left), median concentration of MT-ATP6 in both the Pittsburgh (middle) and Yale (right) IPF cohorts was significantly increased. Data are presented graphically as log base 10 of the raw values of MT-ATP6 copies per microliter of plasma with median value and interquartile range. A graph including the raw values is presented in Figure E6A.