Human umbilical cord mesenchymal stromal cell-derived extracellular vesicles alleviate radiation induced pulmonary fibrosis

Pulmonary fibrosis, a chronic, fatal lung disease affecting millions worldwide, urgently needs more effective treatments. This article comments on the study by Wang <i>et al</i>, which proposed that human umbilical cord mesenchymal stromal cell-derived exosomes alleviate rats radiation induced pulmonary fibrosis. The study demonstrated that these exosomes suppressed inflammation, extracellular matrix deposition, and epithelial-mesenchymal transition by inhibition of AKT signaling in radiation-exposed alveolar epithelial cells. Despite these observations, aspects of the study merit further discussion. Most importantly, further confirmation is needed to prove that the therapeutic effect is exerted through the AKT signaling pathway. Moreover, the definitions of both mesenchymal stem cell and exosomes require further refinement, more rigorous terms should be mesenchymal stromal cell and extracellular vesicles. It seems apparent that this therapy will develop into one of great clinical value.