Inhalations against fibrosis
Idiopathic pulmonary fibrosis is a serious disease in which healthy lung tissue thickens due to inflammation and replacement of mucosal cells with fibrous tissue. In a new study conducted by the University of North Carolina, the group used its own developments over the past five years and tested previously discovered spheroid lung stem cells (LSC) as a therapeutic agent on several animal models of pulmonary fibrosis.
The fact is that lung stem cells are able to recreate a natural microenvironment, known as a stem cell niche, into which cells secrete exosomes to communicate with each other in the same way as inside the body. Lung stem cells release secretions – this is a general term combining exosomes, useful proteins and growth factors that can reproduce the regenerative microenvironment of the cells themselves.
Ke Cheng and his colleagues tested the secretions (LSC-Sec) and exosomes (LSC-Exo) of lung stem cells, comparing them with commonly used mesenchymal stem cells (MSC), on mouse and rat models of chemically induced and silicon dioxide-induced pulmonary fibrosis. The therapeutic agent was delivered through a nebulizer (from Lat. nebula – fog, cloud) in a chamber with an experimental animal, allowing proteins, small molecules and exosomes to be delivered directly to the lungs.
In a mouse model of chemically induced fibrosis, the researchers found that inhalation treatment using LSC-Sec or MSC-Sec resulted in an improvement compared to control – saline inhalation, but LSC-Sec treatment reduced fibrosis by almost 50% compared to 32.4% with MSC-Sec treatment.
In a mouse model of pulmonary fibrosis caused by silicon dioxide, inhalation of LSC-Sec resulted in a 26% decrease in fibrosis compared to a 16.9% decrease in MSC-Sec treatment.
From left to right: healthy lung, pulmonary fibrosis, pulmonary fibrosis after LSC-Sec therapy.
The researchers also created rat models of both types of pulmonary fibrosis, tested the treatment of LSC-Exo and LSC-Sec in comparison with MSC-Exo and obtained similar results. In addition, they found that treatment with LSC-exosomes alone could produce a therapeutic effect similar to LSC-Sec treatment, but the SECRET was the most effective.
Thus, the secretions and exosomes of pulmonary stem cells are more effective in restoring fibrous tissue and reducing inflammation in damaged lung tissue than their counterparts from mesenchymal stem cells. An important advantage of the new therapy is high efficiency combined with low invasiveness: the drug is delivered to the lungs in sufficient quantities using a nebulizer.
Considering the effectiveness of therapy on different models of fibrosis, the authors plan to test the technique for the treatment of other pulmonary diseases, including chronic obstructive pulmonary disease, acute respiratory distress syndrome and pulmonary hypertension.
Article by P-U.C.Dinh et al. Inhalation of lung spheroid cell secretome and exosomes promotes lung repair in pulmonary fibrosis is published in the journal Nature Communications.
Aminat Adzhieva, portal "Eternal Youth" http://vechnayamolodost.ru Based on NC State University News: Inhalation Therapy Shows Promise Against Pulmonary Fibrosis in Mice, Rats.