Abstract Rationale Copper is an essential trace element required for cellular respiration and redox regulation. However, excessive intracellular accumulation can trigger cuproptosis, a recently identified form of regulated cell death. While cuproptosis has been studied in cancer, its relevance to non-oncological inflammatory diseases remains unclear. Acute lung injury (ALI) is characterized by excessive inflammation and diffuse alveolar damage, yet the contribution of copper dysregulation and cuproptosis to its pathogenesis is unknown. Methods Transcriptomic profiling of peripheral white blood cells from patients with severe community-acquired pneumonia was analyzed to assess copper metabolism and cuproptosis-related gene signatures. A murine model of lipopolysaccharide (LPS)-induced ALI was established to evaluate tissue injury, copper accumulation, and markers of cuproptosis. In vitro, alveolar macrophages (MH-S) were exposed to LPS or the copper ionophore Elesclomol to examine intracellular copper dynamics, Pyruvate Dehydrogenase E2 (DLAT) oligomerization, mitochondrial dysfunction, and inflammatory responses. Functional studies were performed by Ferredoxin-1 (Fdx1) knockdown and copper chelation using tetrathiomolybdate (TTM). Results Bioinformatic analysis revealed altered copper metabolism and differential expression of copper-related genes in ALI patients. In LPS-challenged mice, lung copper concentrations were significantly elevated, accompanied by enhanced DLAT oligomerization, loss of Fe-S cluster proteins, and histological injury. DLAT accumulation was predominantly localized in inflammatory regions. In MH-S cells, both LPS and Elesclomol induced intracellular copper overload, DLAT oligomerization, and mitochondrial impairment, consistent with cuproptotic cell death. Fdx1 knockdown suppressed DLAT oligomerization, restored Fe-S protein function, improved cell viability, and attenuated the expression of proinflammatory cytokines Il1b and Tnfa. Similarly, TTM treatment reduced intracellular copper levels, mitigated cuproptosis, and alleviated inflammatory activation both in vitro and in vivo. Mitochondrial respiration assays and transmission electron microscopy demonstrated that copper overload disrupted oxidative phosphorylation and mitochondrial structure, which were preserved by Fdx1 knockdown or TTM pretreatment. Conclusion Our findings demonstrate that dysregulated copper metabolism and consequent cuproptosis contribute to the pathogenesis of ALI. LPS-induced intracellular copper overload triggers DLAT oligomerization, mitochondrial dysfunction, and inflammatory activation, particularly in alveolar macrophages. Inhibition of Fdx1 or pharmacological copper chelation effectively suppresses cuproptosis and mitigates lung injury, highlighting copper homeostasis as a promising therapeutic target for inflammatory lung diseases. This abstract is funded by: National Natural Science Foundation of PR. China, Ministry of Science and Technology of PR. China
Chen et al. (Fri,) studied this question.