- Academic Editor
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Background: Idiopathic pulmonary fibrosis (IPF) is a chronic and
progressive interstitial lung disease (ILD) whose cause and pathogenesis are not
yet well understood. Until now, no animal model of lung fibrosis succeeds in
recapitulating all IPF features, thus the use of different rodent models is
essential for the evaluation and development of new effective pharmacological
treatments. Recently, the alveolar epithelial dysfunction has been emphasized in
the etiopathogenesis context of IPF. Remarkably, the role of an aberrant basaloid
cell type, primarily found in humans and confirmed in mice, seems to be crucial
in the establishment and progression of the disease/model. Our work aimed to
characterize for the first time this cell population in a rat model of lung
fibrosis induced by a double bleomycin (BLM) administration, demonstrating the
translational value of the model and its potential use in the testing of
effective new drugs. Methods: Rats received an intratracheal BLM
administration at day 0 and 4. Animals were sacrificed 21 and 28 days post-BLM.
The fibrosis evaluation was carried out through histological (Ashcroft score and
automatic image analysis) and immunoenzymatic analysis. Immunofluorescence was
used for the characterization of the aberrant basaloid cells markers. Results: Lung histology revealed an increase in severe grades of
Ashcroft scores and areas of fibrosis, resulting in a rise of collagen deposition
at both the analyzed time-points. Immunofluorescence staining indicated the
presence of KRT8+ cells in bronchial epithelial cells from both controls (saline,
SAL) and BLM-treated animals. Interesting, KRT8+ cells were found exclusively in
the fibrotic parenchyma (confirmed by the alpha-smooth muscle actin
(


