Lysine attenuates acute lung injury by restoring α-tubulin acetylation and ciliary activity.

Acute respiratory distress syndrome and pulmonary fibrosis stemming from severe acute lung injury (ALI) continue to incur high mortality due to ineffective pulmonary regeneration. While metabolic reprogramming is known to support alveolar epithelial repair, the specific role of amino acid metabolism remains enigmatic. Through integration of scRNA-seq mining analysis of human ALI samples and targeted plasma metabolomics, we identified that lysine was largely declined in injured pulmonary epithelium, accompanied by a deficiency of mitochondrial metabolism. Lysine supplementation dramatically improved survival (from 0% to 62.5% in mice), attenuated extracellular matrix deposition and alveolitis, and suppressed inflammation in murine and non-human primate ALI models. Mechanistically, lysine replenished acetyl-CoA to restore α-tubulin acetylation for rescuing ciliary TRPC1 localization, which prevented pathological STIM1-TRPC1 complex formation, thereby blocking calcium influx-reduced E-Cadherin/ZO-1 abundance in pulmonary epithelial cells. Notably, ciliogenesis preferentially occurred in SFTPC+ alveolar epithelial type II (AT2) cells; thus, lysine supplementation would promote regenerative activation of AT2 cells. Our work established lysine as a metabolic-structural orchestrator that coordinates acetyl-CoA availability to calcium homeostasis and epithelial repair through tubulin-mediated ciliary signaling.