Identification of Hub Genes for Dexmedetomidine Alleviation of Limb Ischemia-Reperfusion-Induced Lung Injury in Rats by Transcriptomic

BACKGROUND: Limb ischemia-reperfusion (LIR), a prevalent clinical condition, frequently precipitates acute lung injury (ALI). Dexmedetomidine (DEX), a selective alpha2-adrenergic receptor agonist, mitigates LIR-induced ALI. However, its underlying mechanisms remain incompletely elucidated. This study aimed to identify hub genes implicated in DEX-mediated protection against LIR-ALI in rats. METHODS: Sprague-Dawley rats were allocated into five groups (n = 3 per group): Sham (femoral artery exposure without occlusion), LIR, LIR + DEX, LIR + Inhibitor, and LIR + DEX + Inhibitor. LIR was induced by clamping the femoral arteries for 3 hours, followed by reperfusion. DEX (50 μg/kg) or Atipamezole (alpha2-receptor inhibitor, 250 μg/kg) was administered prior to ischemia. Lung injury was evaluated via hematoxylin-eosin staining, wet/dry ratio assessment, and quantification of IL-1beta, TNF-alpha, malondialdehyde (MDA), and superoxide dismutase (SOD) levels. RNA sequencing was performed to identify differentially expressed genes (DEGs), followed by functional enrichment analysis, protein-protein interaction (PPI) network construction, and hub gene identification. Gene-gene interaction (GGI) networks were established. Polymerase chain reaction (PCR) and enzyme linked immunosorbent assay (ELISA) validation was conducted. RESULTS: LIR induced severe lung injury and inflammation, both of which were attenuated by DEX pretreatment. RNA sequencing identified 2,302 DEGs1, 471 DEGs2, 340 DEGs3, and 1,407 DEGs4. After intersection and subtraction analyses, 255 DEX-associated DEGs (DEGs-Dex) and 290 inhibitor-associated DEGs (DEGs-In) were identified, with enrichment in Wnt/PI3K-Akt signaling (DEX) and glycerolipid/butanoate metabolism (In). Nine Hub-Dex genes and four Hub-In genes were identified, among which Selp and Tars1 exhibited a strong positive correlation (correlation = 0.55, P < 0.05). Six hub genes (Tars1, Atf4, Ep300, Sphk1, AABR07051376.1, and Mmp9) were validated. CONCLUSION: Six hub genes associated with DEX-mediated protection against LIR-ALI were identified, providing mechanistic insights and potential therapeutic targets for intervention.