MAPK-Mediated YAP Activation Controls Mechanical-Tension-Induced Pulmonary Alveolar Regeneration

• Increased mechanical tension is essential for post-pneumonectomy alveolar regeneration
• YAP is a key mediator in regulating mechanical tension-induced alveolar regeneration
• Cdc42/F-actin/JNK and p38 MAPK signaling cascade is required for YAP activation

SummaryThe pulmonary alveolar epithelium undergoes extensive regeneration in response to lung injuries, including lung resection. In recent years, our understanding of cell lineage relationships in the pulmonary alveolar epithelium has improved significantly. However, the molecular and cellular mechanisms that regulate pneumonectomy (PNX)-induced alveolar regeneration remain largely unknown. In this study, we demonstrate that mechanical-tension-induced YAP activation in alveolar stem cells plays a major role in promoting post-PNX alveolar regeneration. Our results indicate that JNK and p38 MAPK signaling is critical for mediating actin-cytoskeleton-remodeling-induced nuclear YAP expression in alveolar stem cells. Moreover, we show that Cdc42-controlled actin remodeling is required for the activation of JNK, p38, and YAP in post-PNX lungs. Our findings together establish that the Cdc42/F-actin/MAPK/YAP signaling cascade is essential for promoting alveolar regeneration in response to mechanical tension in the lung.

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