The Role and Expression Patterns of Cuproptosis in Pulmonary Ischemia-Reperfusion Injury: An Experimental Study

Objective : To investigate the mechanistic role of cuproptosis in acute lung ischemia-reperfusion injury (LIRI). Methods : Microarray datasets GSE127003 and GSE9634 were retrieved from the Gene Expression Omnibus (GEO) database to identify and analyze differentially expressed cuproptosis-related genes (CRGs). To validate the bioinformatics findings, 24 male Sprague-Dawley (SD) rats were randomly allocated into three groups: Control, ischemia-reperfusion (I/R), and I/R with ammonium tetrathiomolybdate (ATTM) intervention (I/R+ATTM). The I/R+ATTM group received ATTM pretreatment for copper chelation prior to surgery. An in situ lung I/R injury model was established, and femoral venous blood was collected intraoperatively, while cardiac blood and left lung tissues were harvested postoperatively.Macroscopic evaluation assessed pulmonary hemorrhage, congestion, and edema. Hematoxylin-eosin (H&E) staining was performed for histopathological examination and lung injury scoring. Serum levels of tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), and interleukin-6 (IL-6) were quantified using ELISA. Ceruloplasmin (Cp) levels were measured via a rat-specific assay kit. Western blotting analyzed pulmonary expression of ferredoxin 1 (FDX1), lipoic acid synthetase (LIAS), dihydrolipoyl transacetylase (DLAT), DLAT oligomers, dihydrolipoamide succinyltransferase (DLST), succinate dehydrogenase complex subunit B (SDHB), lipoylated DLAT (Lip-DLAT), and lipoylated DLST (Lip-DLST). Immunohistochemistry (IHC) localized FDX1, Lip-DLAT, and Lip-DLST expression in lung tissues. Results : Differential gene analysis revealed significant alterations in CRG RNA expression during lung I/R (P < 0.05). Histopathological assessment demonstrated severe injury in the I/R group, moderate in I/R+ATTM, and minimal in Controls (P < 0.01). Serum TNF-α, IL-1β, and IL-6 levels in I/R+ATTM were elevated versus Controls (P < 0.0001) but reduced compared to I/R (P < 0.05). ATTM intervention significantly decreased serum Cp (P < 0.001). Pulmonary FDX1, LIAS, DLAT, DLST, SDHB, Lip-DLAT, and Lip-DLST expression in I/R+ATTM was lower than I/R (P < 0.05) but remained higher than Controls (P < 0.05). DLAT oligomers increased versus Controls (P < 0.05) but were suppressed relative to I/R (P < 0.0001). IHC confirmed cytoplasmic localization of FDX1 and lipoylated proteins, with I/R+ATTM showing intermediate expression between I/R and Controls (P < 0.05). Conclusion : In a rat model of in situ lung ischemia-reperfusion, cuproptosis exacerbates acute lung injury by modulating key protein effectors, while copper chelation partially mitigates this pathological progression.