Tensile Overload Injures Human Alveolar Epithelial Cells through YAP/F-Actin/MAPK Signaling

Background: Explosion shockwaves can generate overloaded mechanical forces and induce lung injuries. However, the mechanism of lung injuries caused by tensile overload is still unclear.

Methods: Flow cytometry was used to detect the Apoptosis of human alveolar epithelial cells (BEAS-2B) induced by tensile overload, and cell proliferation was detected using 5-ethynyl-2'-deoxyuridine (EdU). Immunofluorescence and Western blot analysis were used to identify the tensile overload on the actin Cytoskeleton, proteins related to the mitogen-activated protein kinase (MAPK) signal pathway, and the Yes-associated protein (YAP).

Results: Tensile overload reduced BEAS-2B cell proliferation and increased Apoptosis. In terms of the mechanism, we found that tensile overload led to the depolymerization of the actin Cytoskeleton, the activation of c-Jun N-terminal kinase (JNK) and extracellular-signal-regulated kinase 1/2 (ERK1/2), and the upregulation of YAP expression. Jasplakinolide (Jasp) treatment promoted the polymerization of the actin Cytoskeleton and reduced the phosphorylation of tension-overload-activated JNK and ERK1/2 and the Apoptosis of BEAS-2B cells. Moreover, the inhibition of the JNK and ERK1/2 signaling pathways, as well as the expression of YAP, also reduced Apoptosis caused by tensile overload.

Conclusion: Our study establishes the role of the YAP/F-actin/MAPK axis in tensile-induced BEAS-2B cell injury and proposes new strategies for the treatment and repair of future lung injuries.

ERK1/2; F-actin; JNK; apoptosis; human alveolar epithelial cells; tensile overload.