1. IL-17A promotes lung fibrosis through impairing mitochondrial homeostasis in type II alveolar epithelial cells.
- Author
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Xiao H, Peng L, Jiang D, Liu Y, Zhu L, Li Z, Geng J, Xie B, Huang X, Wang J, Dai H, and Wang C
- Subjects
- Animals, Mice, Bleomycin pharmacology, Epithelial Cells metabolism, Fibrosis, Homeostasis, Interleukin-17 metabolism, Lung pathology, Mitochondria metabolism, Protein Kinases metabolism, Alveolar Epithelial Cells metabolism, Idiopathic Pulmonary Fibrosis chemically induced, Idiopathic Pulmonary Fibrosis genetics, Idiopathic Pulmonary Fibrosis metabolism
- Abstract
The dysfunction of type II alveolar epithelial cells (AECIIs), mainly manifested by apoptosis, has emerged as a major component of idiopathic pulmonary fibrosis (IPF) pathophysiology. A pivotal mechanism leading to AECIIs apoptosis is mitochondrial dysfunction. Recently, interleukin (IL)-17A has been demonstrated to have a pro-fibrotic role in IPF, though the mechanism is unclear. In this study, we report enhanced expression of IL-17 receptor A (IL-17RA) in AECIIs in lung samples of IPF patients, which may be related to the accumulation of mitochondria in AECIIs of IPF. Next, we investigated this relationship in bleomycin (BLM)-induced PF murine model. We found that IL-17A knockout (IL-17A
-/- ) mice exhibited decreased apoptosis levels of AECIIs. This was possibly a result of the recovery of mitochondrial morphology from the improved mitochondrial dynamics of AECIIs, which eventually contributed to alleviating lung fibrosis. Analysis of in vitro data indicates that IL-17A impairs mitochondrial function and mitochondrial dynamics of mouse primary AECIIs, further promoting apoptosis. PTEN-induced putative kinase 1 (PINK1)/Parkin signal-mediated mitophagy is an important aspect of mitochondria homeostasis maintenance. Our data demonstrate that IL-17A inhibits mitophagy and promotes apoptosis of AECIIs by decreasing the expression levels of PINK1. We conclude that IL-17A exerts its pro-fibrotic effects by inducing mitochondrial dysfunction in AECIIs by disturbing mitochondrial dynamics and inhibiting PINK1-mediated mitophagy, thereby leading to apoptosis of AECIIs., (© 2022 The Authors. Journal of Cellular and Molecular Medicine published by Foundation for Cellular and Molecular Medicine and John Wiley & Sons Ltd.)- Published
- 2022
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