Fig. 6.

PACS2 protein and ER–mitochondrial tethering are decreased in IPF AECII. A Representative immunofluorescence images for PACS2 (red) and ABCA3 (green) in IPF and Donor lung sections, and nuclei were stained with DAPI (blue) scale bar = 25 µm. B Fluorescence intensity of PACS2 was quantified using ImageJ, and its intensity in Donor sections was set as one. Lung sections from seven IPF to seven Donors were used for stainings. Statistical significance is indicated as: *p ≤ 0.05. C Representative transmission electron microscopic images from alveolar epithelial type II cells (characterized by the presence of lamellar bodies (LB)) are shown. At the ultrastructural level, the appearance of the contact zones between ER and mitochondria (Mito) in IPF differed from the healthy control. The closest contacts (arrows) appeared to be rather point shaped with the ER piston-like widened in IPF. In healthy controls, the contacts were in general elongated and more laminar so that the ER and mitochondrial membranes had a parallel run