Figure 4From: JNK suppresses pulmonary fibroblast elastogenesis during alveolar developmentJNK is activated in lipofibroblasts during alveolar development. (A) By lineage tracing of lung mesenchymal cells, pJNK (purple) was located within mesenchymal cells (green), and not epithelial cells (red). 20× image. (B) An enlarged area of the confocal image with Z-plane sectioning showed that individual mesenchymal cells were located entirely within the green-stained mesenchymal cells. Scale bar = 5 μm. (C-E) Monochromatic images with z-planes demonstrated the presence of pJNK within mesenchymal cells. (F) Fibroblasts constitute only a subset of lung mesenchymal cells. Co-staining for pJNK and vimentin demonstrated that pJNK was localized to vimentin-positive cells although many vimentin positive cells did not contain pJNK. 40× image. (G) Lung myofibroblast were identified by staining for α-smooth muscle actin (αSMA). pJNK did not localize with αSMA positive cells. 40× image. (H) Lung lipofibroblasts were identified by Oil-Red-O staining. Using immunofluorescent imaging and differential interference contrast microscopy pJNK was located within interstitial cells having increased numbers lipid droplets but not within lipid-containing cells in airspaces (i.e. macrophages, upper right). 40× image, Scale Bar = 50 μm. Images are representative of sections from at least three different animals.Back to article page