Low-level laser therapy attenuates lung inflammation and airway remodeling in a murine model of idiopathic pulmonary fibrosis: Relevance to cytokines secretion from lung structural cells

Published: Journal of Photochemistry and Photobiology B: Biology, Volume 203, January 2020, 111731.

Keyword: Pulmonary fibrosis, Airway remodeling, Fibroblasts, Cytokines, Photobiomodulation

Author(s): Auriléia Aparecida deBrito, Elaine Cristinada Silveira, Nicole Cristine Rigonato-Oliveira, Stephanie Souza Soares, Maysa Alves Rodrigues Brandao-Rangel, Clariana Rodrigues Soares, Tawany Gonçalves Santos, Cintia Estefano Alvesa, Karine Zanella Herculano, Rodolfo Paula Vieira, Adriana Lino-dos-Santos-Franco, Regiane Albertini, Flavio Aimbire, Ana Paula de Oliveira.

Overview:  The present study investigated if laser attenuates cellular migration to the lungs, the airway remodeling as well as pro-fibrotic cytokines secretion from type II pneumocytes and fibroblasts. Mice were irradiated (780 nm and 30 mW) and then euthanized fifteen days after bleomycin-induced lung fibrosis.

Materials/Methods:

• For in vitro assays, bleomycin-activated fibroblasts and type II pneumocytes were irradiated with laser.
• The pro- and anti-inflammatory cytokines level in BALF as well as cells supernatant were measured by ELISA, and the TGFβ in lung was evaluated by flow cytometry.
• Lung histology was used to analyze collagen fibers around the airways.

Results: 

• LLLT reduced both migration of inflammatory cells and deposition of collagen fibers in the lungs.
• In addition, LLLT downregulated pro-inflammatory cytokines and upregulated the IL-10 secretion from fibroblasts and pneumocytes.
• Laser therapy greatly reduced total lung TGFβ. Systemically, LLLT also reduced the inflammatory cells counted in blood.

Conclusions: Data obtained indicate that laser effectively attenuates the lung inflammation, and the airway remodeling in experimental pulmonary fibrosis is driven to restore the balance between the pro- and anti-inflammatory cytokines in lung and inhibit the pro-fibrotic cytokines secretion from fibroblasts