# Extracellular Superoxide Dismutase in Acute Respiratory Distress Syndrome: Pathogenic Mechanisms and Therapeutic Implications **Authors:** William Osier, Eva S. Nozik, Christina Sul PMC · DOI: 10.3390/antiox15020249 · Antioxidants · 2026-02-13 ## TL;DR This paper reviews how extracellular superoxide dismutase (EC-SOD) regulates lung redox balance and its potential as a therapeutic target in acute respiratory distress syndrome (ARDS). ## Contribution The paper provides a comprehensive review of EC-SOD's role in ARDS pathogenesis and highlights novel therapeutic strategies based on EC-SOD modulation. ## Key findings - Loss of EC-SOD worsens immune responses in acute lung injury models. - Enhanced EC-SOD activity protects against lung injury in experimental models. - Genetic and epigenetic factors influence EC-SOD expression and function in ARDS. ## Abstract The lung is highly susceptible to oxidative stress because of its exposure to high oxygen tension and environmental stressors, making tight regulation of the redox environment essential for homeostasis and disease pathogenesis. Extracellular superoxide dismutase (EC-SOD, sod3) is an important antioxidant enzyme in the lung that catalyzes the dismutation of superoxide into hydrogen peroxide and oxygen, thereby regulating the redox environment of the extracellular matrix, cell surfaces, and lining fluids of the lung. This review summarizes the structural features, post-translational regulation, genetic variations, and cellular sources of EC-SOD, with a particular focus on its role in acute respiratory distress syndrome (ARDS). We highlight evidence demonstrating that loss of EC-SOD exacerbates dysregulated immune responses, whereas enhanced EC-SOD activity confers protection in multiple experimental models of acute lung injury. We also discuss how inflammatory signaling, epigenetic regulation, aging, and genetic polymorphisms in the sod3 gene influence EC-SOD expression and function. Finally, we review emerging therapeutic strategies, including SOD mimetics and mRNA-based approaches, and address the challenges associated with non-specific antioxidant therapies in ARDS. Collectively, the data position EC-SOD as a central regulator of extracellular redox signaling and a promising, mechanism-driven therapeutic target in acute lung injury and ARDS. ## Linked entities - **Genes:** SOD3 (superoxide dismutase 3) [NCBI Gene 6649] - **Proteins:** SOD3 (superoxide dismutase 3) - **Diseases:** acute respiratory distress syndrome (MONDO:0006502), ARDS (MONDO:0006502), acute lung injury (MONDO:0006502) ## Full-text entities - **Genes:** CCL2 (C-C motif chemokine ligand 2) [NCBI Gene 6347] {aka GDCF-2, HC11, HSMCR30, MCAF, MCP-1, MCP1}, IL1B (interleukin 1 beta) [NCBI Gene 3553] {aka IL-1, IL1-BETA, IL1F2, IL1beta}, PTPN1 (protein tyrosine phosphatase non-receptor type 1) [NCBI Gene 5770] {aka PTP1B}, CYBB (cytochrome b-245 beta chain) [NCBI Gene 1536] {aka AMCBX2, CGD, CGDX, GP91-1, GP91-PHOX, GP91PHOX}, TLR4 (toll like receptor 4) [NCBI Gene 7099] {aka ARMD10, CD284, TLR-4, TOLL}, SP3 (Sp3 transcription factor) [NCBI Gene 6670] {aka SPR2}, SOD3 (superoxide dismutase 3) [NCBI Gene 6649] {aka EC-SOD}, STAT3 (signal transducer and activator of transcription 3) [NCBI Gene 6774] {aka ADMIO, ADMIO1, APRF, HIES}, TNF (tumor necrosis factor) [NCBI Gene 7124] {aka DIF, IMD127, TNF-alpha, TNFA, TNFSF2, TNLG1F}, GSR (glutathione-disulfide reductase) [NCBI Gene 2936] {aka CNSHA10, GR, GSRD, HEL-75, HEL-S-122m}, FURIN (furin, paired basic amino acid cleaving enzyme) [NCBI Gene 5045] {aka FUR, PACE, PCSK3, SPC1}, LRP1 (LDL receptor related protein 1) [NCBI Gene 4035] {aka A2MR, APOER, APR, CD91, DDH3, IGFBP-3R}, SOD2 (superoxide dismutase 2) [NCBI Gene 6648] {aka GC1, GClnc1, IPO-B, IPOB, MNSOD, MVCD6}, SDC1 (syndecan 1) [NCBI Gene 6382] {aka CD138, SDC, SYND1, syndecan}, SIRT1 (sirtuin 1) [NCBI Gene 23411] {aka SIR2, SIR2L1, SIR2alpha}, VEGFA (vascular endothelial growth factor A) [NCBI Gene 7422] {aka L-VEGF, MVCD1, VEGF, VPF}, NOS2 (nitric oxide synthase 2) [NCBI Gene 4843] {aka HEP-NOS, INOS, NOS, NOS2A}, CASP3 (caspase 3) [NCBI Gene 836] {aka CPP32, CPP32B, SCA-1}, NFKB1 (nuclear factor kappa B subunit 1) [NCBI Gene 4790] {aka CVID12, EBP-1, KBF1, NF-kB, NF-kB1, NF-kappa-B1}, CXCL8 (C-X-C motif chemokine ligand 8) [NCBI Gene 3576] {aka GCP-1, GCP1, IL8, LECT, LUCT, LYNAP}, HPSE (heparanase) [NCBI Gene 10855] {aka HPA, HPA1, HPR1, HPSE1, HSE1}, TGFB1 (transforming growth factor beta 1) [NCBI Gene 7040] {aka CAEND1, CED, DPD1, IBDIMDE, LAP, TGF-beta1}, CAT (catalase) [NCBI Gene 847], AGT (angiotensinogen) [NCBI Gene 183] {aka ANHU, SERPINA8, hFLT1}, SOD1 (superoxide dismutase 1) [NCBI Gene 6647] {aka ALS, ALS1, HEL-S-44, IPOA, SOD, STAHP}, IFI44 (interferon induced protein 44) [NCBI Gene 10561] {aka MTAP44, TLDC5, p44}, IL6 (interleukin 6) [NCBI Gene 3569] {aka BSF-2, BSF2, CDF, HGF, HSF, IFN-beta-2}, IL17A (interleukin 17A) [NCBI Gene 3605] {aka CTLA-8, CTLA8, IL-17, IL-17A, IL17, ILA17}, PTPRJ (protein tyrosine phosphatase receptor type J) [NCBI Gene 5795] {aka CD148, DEP1, HPTP eta, HPTPeta, R-PTP-ETA, R-PTP-J}, ATOX1 (antioxidant 1 copper chaperone) [NCBI Gene 475] {aka ATX1, HAH1}, IRF3 (interferon regulatory factor 3) [NCBI Gene 3661] {aka IIAE7}, SP1 (Sp1 transcription factor) [NCBI Gene 6667], CDH5 (cadherin 5) [NCBI Gene 1003] {aka 7B4, CD144}, CTSG (cathepsin G) [NCBI Gene 1511] {aka CATG, CG}, IFNG (interferon gamma) [NCBI Gene 3458] {aka IFG, IFI, IMD69}, CCL7 (C-C motif chemokine ligand 7) [NCBI Gene 6354] {aka FIC, MARC, MCP-3, MCP3, NC28, SCYA6}, SIRT3 (sirtuin 3) [NCBI Gene 23410] {aka SIR2L3}, JAK2 (Janus kinase 2) [NCBI Gene 3717] {aka JTK10} - **Diseases:** tumor (MESH:D009369), diabetes (MESH:D003920), lung injury (MESH:D055370), chronic kidney disease (MESH:D051436), asthma (MESH:D001249), pre-eclampsia (MESH:D011225), pulmonary edema (MESH:D011654), acute lung injury (MESH:D055371), fetal growth restriction (MESH:D005317), critical illness (MESH:D016638), platelet-neutrophil aggregation (MESH:D001791), inflammation (MESH:D007249), injury to (MESH:D014947), hyperoxia (MESH:D018496), ARDS (MESH:D012128), hypoxemia (MESH:D000860), hemorrhage (MESH:D006470), Organ Failure (MESH:D009102), S. aureus pneumonia (MESH:D011023), NETs (MESH:C536657), acute respiratory failure (MESH:D012131), pneumonia (MESH:D011014), right heart strain (MESH:D013180), acute kidney injury (MESH:D058186), COPD (MESH:D029424), COVID-19 (MESH:D000086382), infection (MESH:D007239), diabetic neuropathy (MESH:D003929), cardiovascular, inflammatory, and pulmonary diseases (MESH:D002318), myocardial infarction (MESH:D009203), reduced insulin sensitivity (MESH:D007333), cytotoxicity (MESH:D064420), weight loss (MESH:D015431), idiopathic pulmonary arterial hypertension (MESH:D065627), vascular dysfunction (MESH:D002561), endothelial injury (MESH:D057772), E. coli pneumonia (MESH:D004927), bronchopulmonary dysplasia (MESH:D001997), endotoxemia (MESH:D019446), thrombosis (MESH:D013927), microvascular thrombosis (MESH:D017566), pulmonary neutrophilia (MESH:C563010), pulmonary arterial hypertension (MESH:D000081029), Mortality (MESH:D003643), hypertension (MESH:D006973), septic shock (MESH:D012772), acute pulmonary hypertension (MESH:D006976), Sepsis (MESH:D018805), radiation (MESH:D011832), breast cancer (MESH:D001943), renal dysfunction (MESH:D007674), aspiration (MESH:D011015), bacterial infections (MESH:D001424), type 2 diabetes (MESH:D003924), coronary artery disease (MESH:D003324), myocardial reperfusion injury (MESH:D015428) - **Chemicals:** MDA (MESH:D015104), His (MESH:D006639), glycan (MESH:D011134), NO2 (MESH:D009585), Pro (MESH:D011392), cGMP (MESH:D006152), molecular oxygen (MESH:D010100), zinc (MESH:D015032), salt (MESH:D012492), Glu (MESH:D018698), bleomycin (MESH:D001761), copper (MESH:D003300), Vitamin C (MESH:D001205), hyaluronan (MESH:D006820), hydroxyl radical (MESH:D017665), Asn (MESH:D001216), NO (MESH:D009569), EUK-8 (MESH:C090577), water (MESH:D014867), AVA (MESH:C053511), acetyl coenzyme A. (MESH:D000105), Fe (MESH:D007501), nitrotyrosine (MESH:C002744), amino acids (MESH:D000596), NADPH (MESH:D009249), lipofectamine (MESH:C086724), Arg (MESH:D001120), malondialdehyde (MESH:D008315), EUK-189 (MESH:C436526), heparan sulfate (MESH:D006497), superoxide (MESH:D013481), EUK (-), H2O2 (MESH:D006861), disulfide (MESH:D004220), MnTE-2-PyP (MESH:C520506), glycosaminoglycans (MESH:D006025), N-acetylcysteine (MESH:D000111), Heparin (MESH:D006493), Antileukinate (MESH:C118980), M40403 (MESH:C121876), GC4419 (MESH:C000707700), ROS (MESH:D017382), S-acetyl glutathione (MESH:C096306), perhydroxyl radical (MESH:C049375), Mn (MESH:D008345), peroxynitrite (MESH:D030421), glutathione (MESH:D005978), metalloporphyrins (MESH:D008665), AEOL 10150 (MESH:C472668), OH (MESH:C031356), lipid (MESH:D008055), Cys (MESH:D003545), LPS (MESH:D008070) - **Species:** Mus musculus (house mouse, species) [taxon 10090], Mycoplasmoides pneumoniae (Filterable agent of primary atypical pneumonia, species) [taxon 2104], Escherichia coli (E. coli, species) [taxon 562], Sus scrofa (pig, species) [taxon 9823], Severe acute respiratory syndrome coronavirus 2 (no rank) [taxon 2697049], Staphylococcus aureus (species) [taxon 1280], Rattus norvegicus (brown rat, species) [taxon 10116], Homo sapiens (human, species) [taxon 9606], Bos taurus (bovine, species) [taxon 9913] - **Mutations:** Arg to Gly, Phe131Cys, Ala40Thr, rs8192287, Arg213 Gly, rs8192288 ## Full text _Full body text omitted from this summary view._ Fetch the complete paper as Markdown: https://tomesphere.com/paper/PMC12937663/full.md ## Figures 3 figures with captions in the complete paper: https://tomesphere.com/paper/PMC12937663/full.md ## References 238 references — full list in the complete paper: https://tomesphere.com/paper/PMC12937663/full.md --- Source: https://tomesphere.com/paper/PMC12937663