The dynamic uptake and release of SOD3 from intracellular stores in macrophages modulates the inflammatory response

A Multi-Omics Approach to Defining Target Organ Injury in Youth with Primary Hypertension

BACKGROUND

Primary hypertension in childhood tracks into adulthood and may be associated with increased cardiovascular risk. Studies conducted in children and adolescents provide an opportunity to explore the early cardiovascular target organ injury (CV-TOI) in a population free from many of the comorbid cardiovascular disease risk factors that confound studies in adults.

METHODS

Youths (n=132, mean age 15.8 years) were stratified by blood pressure (BP) as low, elevated, and high-BP and by left ventricular mass index (LVMI) as low- and high-LVMI. Systemic circulating RNA, miRNA, and methylation profiles in peripheral blood mononuclear cells and deep proteome profiles in serum were determined using high-throughput sequencing techniques.

RESULTS

VASH1 gene expression was elevated in youths with high-BP with and without high-LVMI. VASH1 expression levels positively correlated with systolic BP (r=0.3143, p=0.0034). The expression of hsa-miR-335-5p, one of the VASH1-predicted miRNAs, was downregulated in high-BP with high-LVMI youths and was inversely correlated with systolic BP (r=-0.1891, p=0.0489). GSE1 hypermethylation, circulating PROZ upregulation (log2FC=0.61, p=0.0049 and log2FC=0.62, p=0.0064), and SOD3 downregulation (log2FC=-0.70, p=0.0042 and log2FC=-0.64, p=0.010) were observed in youths with elevated BP and high-BP with high-LVMI. Comparing the transcriptomic and proteomic profiles revealed elevated HYAL1 levels in youths displaying high-BP and high-LVMI.

CONCLUSIONS

The findings are compatible with a novel blood pressure-associated mechanism that may occur through impaired angiogenesis and extracellular matrix degradation through dysregulation of Vasohibin-1 and Hyaluronidase1 was identified as a possible mediator of CV-TOI in youth with high-BP and suggests strategies for ameliorating TOI in adult-onset primary hypertension.

SOD3 suppresses early cellular immune responses to parasite infection

Host immune responses are tightly controlled by various immune factors during infection, and protozoan parasites also manipulate the immune system to evade surveillance, leading to an evolutionary arms race in host‒pathogen interactions; however, the underlying mechanisms are not fully understood. We observed that the level of superoxide dismutase 3 (SOD3) was significantly elevated in both Plasmodium falciparum malaria patients and mice infected with four parasite species. SOD3-deficient mice had a substantially longer survival time and lower parasitemia than control mice after infection, whereas SOD3-overexpressing mice were much more vulnerable to parasite infection. We revealed that SOD3, secreted from activated neutrophils, bound to T cells, suppressed the interleukin-2 expression and concomitant interferon-gamma responses crucial for parasite clearance. Overall, our findings expose active fronts in the arms race between the parasites and host immune system and provide insights into the roles of SOD3 in shaping host innate immune responses to parasite infection.

Radical-Generating Activity, Phagocytosis, and Mechanical Properties of Four Phenotypes of Human Macrophages

Macrophages are the major players and orchestrators of inflammatory response. Expressed proteins and secreted cytokines have been well studied for two polar macrophage phenotypes-pro-inflammatory M1 and anti-inflammatory regenerative M2, but little is known about how the polarization modulates macrophage functions. In this study, we used biochemical and biophysical methods to compare the functional activity and mechanical properties of activated human macrophages differentiated from monocyte with GM-CSF (M0_GM) and M-CSF (M0_M) and polarized into M1 and M2 phenotypes, respectively. Unlike GM-CSF, which generates dormant cells with low activity, M-CSF confers functional activity on macrophages. M0_M and M2 macrophages had very similar functional characteristics-high reactive oxygen species (ROS) production level, and higher phagocytosis and survival compared to M1, while M1 macrophages showed the highest radical-generating activity but the lowest phagocytosis and survival among all phenotypes. All phenotypes decreased their height upon activation, but only M1 and M2 cells increased in stiffness, which can indicate a decrease in the migration ability of these cells and changes in their interactions with other cells. Our results demonstrated that while mechanical properties differ between M0 and polarized cells, all four phenotypes of monocyte-derived macrophages differ in their functional activities, namely in cytokine secretion, ROS production, and phagocytosis. Within the broad continuum of human macrophages obtained in experimental models and existing in vivo, there is a diversity of phenotypes with varying combinations of both markers and functional activities.

Oxidative stress is involved in immunosuppression and macrophage regulation in glioblastoma

Oxidative stress dually affected cancer progression, while its effect on glioblastomas remained unclear. Herein, we clustered the multicenter glioblastoma cohorts based on the oxidative-stress-responsive genes (OSS) expression. We found that cluster 2 with high OSS levels suffered a worse prognosis. Functional analyses and immune-related analyses results exhibited that M2-like pro-tumoral macrophages and neutrophils were enriched in cluster 2, while Natural killer cells' infiltration was decreased. The increased M2-like pro-tumoral macrophages in cluster 2 was confirmed by immunofluorescence. An integrated single-cell analysis validated the malignant features of cluster 2 neoplastic cells and discovered their crosstalk with M2-like pro-tumoral macrophages. Moreover, we observed that SOD3 knockdown might decrease the M2-like pro-tumoral transformation of macrophage in vitro and in vivo. Comprehensively, we revealed oxidative stress' prognostic and immunosuppressive potential in glioblastoma and discovered SOD3's potential role in regulating macrophage M2-like pro-tumoral transformation.

Uncovering SOD3 and GPX4 as new targets of Benzo[α]pyrene-induced hepatotoxicity through Metabolomics and Chemical Proteomics

Benzo[α]pyrene (Bap) is recognized as a ubiquitous environmental pollutant among the polycyclic aromatic hydrocarbons (PAHs) class. Previous studies have shown that the hepatotoxicity of Bap is mainly caused by its metabolites, although it remains unclear whether Bap itself induces such damage. This study integrated metabolomics and chemical proteomics approaches to comprehensively identify the potential target proteins affected by Bap in liver cells. The results from the metabolomics showed that the significant changed metabolites were related with cellular redox homeostasis. CEllular Thermal Shift Assay (CETSA) showed that Bap induced protein thermal displacement of superoxide dismutase 3 (SOD3) and glutathione peroxidase 4 (GPX4), which are closely related to oxidative homeostasis. Further validation through in vitro CETSA and drug affinity response target stability (DARTS) revealed that Bap directly affected the stability of SOD3 and GPX4 proteins. The binding affinities of Bap to the potential target proteins were further evaluated using molecular docking, while the isothermal titration calorimetry (ITC) interaction measurements indicated nanomolar-level Kd values. Importantly, we found that Bap weakened the antioxidant capacity by destroying the activities of SOD3 and GPX4, which provided a new understanding of the mechanism of hepatotoxicity induced by Bap. Moreover, our provided workflow integrating metabolomics and label-free chemical proteomics, can be regarded as a practical way to identify the targets and inter-mechanisms for the various environmental compounds.

Effects of Rosmarinus officinalis L. Extract on Neurobehavioral and Neurobiological Changes in Male Rats with Pentylenetetrazol-Induced Epilepsy

This study investigated the effect of Rosmarinus officinalis L. (RO) extract on neurobehavioral and neurobiological changes in male rats with pentylenetetrazol (PTZ)-induced epilepsy. Rats were assigned into five groups: (1) control rats, (2) RO-treated rats, (3) PTZ-treated rats, (4) PTZ + RO-treated rats, and (5) PTZ + valproic acid (VA)-treated rats. The PTZ-treated rats required a significantly longer time and distance to find the platform in the Morris water maze test than the control and RO-treated rats. Additionally, PTZ-treated rats showed a decrease in tendency to cross over the platform compared to PTZ group. PTZ + RO-treated rats showed decreased swimming time and distance to find the platform compared to PTZ group. PTZ + RO-treated rats showed a significant decrease in seizure score, a reduced number of myoclonic jerks, and an increased onset of the first myoclonic jerk compared to PTZ group. PTZ reduced the time required to enter the dark room in the passive avoidance learning test, which was reversed by RO treatment. Biochemical results revealed that PTZ-treated rats had higher levels of oxidative stress markers. RO significantly increased the antioxidant markers levels and maintained normal rat brain histology. This study revealed that RO can shield the brain and neural tissues from PTZ.

Aerosolized Pulmonary Delivery of mRNA Constructs Attenuates Severity of Escherichia coli Pneumonia in the Rat

Acute respiratory distress syndrome (ARDS), a rapid onset inflammatory lung disease with no effective specific therapy, typically has pathogenic etiology termed pneumonia. In previous studies nuclear factor-κB (NF-κB) inhibitor α super-repressor (IκBα-SR) and extracellular superoxide dismutase 3 (SOD3) reduced pneumonia severity when prophylactically delivered by viral vector. In this study, mRNA coding for green fluorescent protein, IκBα-SR, or SOD3 was complexed with cationic lipid, passed through a vibrating mesh nebulizer, and delivered to cell culture or directly to rats undergoing Escherichia coli pneumonia. Injury level was then assessed at 48 h. In vitro, expression was observed as early as 4 h in lung epithelial cells. IκBα-SR and wild-type IκBα mRNAs attenuated inflammatory markers, while SOD3 mRNA induced protective and antioxidant effects. In rat E. coli pneumonia, IκBα-SR mRNA reduced arterial carbon dioxide (pCO2) and reduced lung wet/dry ratio. SOD3 mRNA improved static lung compliance and alveolar-arterial oxygen gradient (AaDO2) and decreased bronchoalveolar lavage (BAL) bacteria load. White cell infiltration and inflammatory cytokine concentrations in BAL and serum were reduced by both mRNA treatments compared to scrambled mRNA controls. These findings indicate nebulized mRNA therapeutics are a promising approach to ARDS therapy, with rapid expression of protein and observable amelioration of pneumonia symptoms.

BNTA alleviates inflammatory osteolysis by the SOD mediated anti-oxidation and anti-inflammation effect on inhibiting osteoclastogenesis

Abnormal activation and overproliferation of osteoclast in inflammatory bone diseases lead to osteolysis and bone mass loss. Although current pharmacological treatments have made extensive advances, limitations still exist. N-[2-bromo-4-(phenylsulfonyl)-3-thienyl]-2-chlorobenzamide (BNTA) is an artificially synthesized molecule compound that has antioxidant and anti-inflammatory properties. In this study, we presented that BNTA can suppress intracellular ROS levels through increasing ROS scavenging enzymes SOD1 and SOD2, subsequently attenuating the MARK signaling pathway and the transcription of NFATc1, leading to the inhibition of osteoclast formation and osteolytic resorption. Moreover, the results also showed an obvious restrained effect of BNTA on RANKL-stimulated proinflammatory cytokines, which indirectly mediated osteoclastogenesis. In line with the in vitro results, BNTA protected LPS-induced severe bone loss in vivo by enhancing scavenging enzymes, reducing proinflammatory cytokines, and decreasing osteoclast formation. Taken together, all of the results demonstrate that BNTA effectively represses oxidation, regulates inflammatory activity, and inhibits osteolytic bone resorption, and it may be a potential and exploitable drug to prevent inflammatory osteolytic bone diseases.

Nox2-derived superoxide radical is crucial to control acute Trypanosoma cruzi infection

Trypanosoma cruzi is a flagellated protozoan that undergoes a complex life cycle between hematophagous insects and mammals. In humans, this parasite causes Chagas disease, which in thirty percent of those infected, would result in serious chronic pathologies and even death. Macrophages participate in the first stages of infection, mounting a cytotoxic response which promotes massive oxidative damage to the parasite. On the other hand, T. cruzi is equipped with a robust antioxidant system to repeal the oxidative attack from macrophages. This work was conceived to explicitly assess the role of mammalian cell-derived superoxide radical in a murine model of acute infection by T. cruzi. Macrophages derived from Nox2-deficient (gp91^phox-/-) mice produced marginal amounts of superoxide radical and were more susceptible to parasite infection than those derived from wild type (wt) animals. Also, the lack of superoxide radical led to an impairment of parasite differentiation inside gp91^phox-/- macrophages. Biochemical or genetic reconstitution of intraphagosomal superoxide radical formation in gp91^phox-/- macrophages reverted the lack of control of infection. Along the same line, gp91^phox-/- infected mice died shortly after infection. In spite of the higher lethality, parasitemia did not differ between gp91^phox-/- and wt animals, recapitulating an observation that has led to conflicting interpretations about the importance of the mammalian oxidative response against T. cruzi. Importantly, gp91^phox-/- mice presented higher and disseminated tissue parasitism, as evaluated by both qPCR- and bioimaging-based methodologies. Thus, this work supports that Nox2-derived superoxide radical plays a crucial role to control T. cruzi infection in the early phase of a murine model of Chagas disease.

∙

Nox2 derived-superoxide radical is required to control Trypanosoma cruzi infection in macrophages

∙Nox2-deficient mice (gp91^phox-/-) are highly susceptible to Trypanosoma cruzi infection

∙Parasitemia does not reflect the level of organ infection observed in wt and gp91^phox-/- mice.

∙gp91^phox-/- mice collapse to infection due to uncontrolled parasite proliferation in tissues

Epigenetic Regulation by Suv4-20h1 in Cardiopulmonary Progenitor Cells is Required to Prevent Pulmonary Hypertension and COPD

Background: The etiology of life-threatening cardiopulmonary diseases such as Pulmonary Hypertension (PH) and Chronic Obstructive Pulmonary Disease (COPD) originates from a complex interplay of environmental factors and genetic predispositions, which is not fully understood. Likewise, little is known about developmental abnormalities or epigenetic dysregulations that might predispose for PH or COPD in adult individuals. Methods: To identify pathology-associated epigenetic alteration in diseased lung tissues, we screened a cohort of human PH and COPD patients for changes of histone modifications by immunofluorescence staining. To analyze the function of H4K20me2/3 in lung pathogenesis, we developed a series of Suv4-20h1 knockout mouse lines targeting cardiopulmonary progenitor cells (CPPs) and different heart and lung cell types, followed by hemodynamic studies and morphometric assessment of tissue samples. Molecular, cellular and biochemical techniques were applied to analyze the function of Suv4-20h1-dependent epigenetic processes in cardiopulmonary progenitor cells and their derivatives. Results: We discovered a strong reduction of the histone modifications H4K20me2/3 in human COPD but not PH patients, which depend on the activity of the H4K20 di-methyltransferase SUV4-20H1. Loss of Suv4-20h1 in CPPs caused a COPD-like/PH phenotype in mice including formation of perivascular tertiary lymphoid tissue and goblet cell hyperplasia, hyper-proliferation of smooth muscle cells/myofibroblasts, impaired alveolarization and maturation defects of the microvasculature leading to massive right ventricular dilatation and premature death. Mechanistically, SUV4-20H1 binds directly to the 5'-upstream regulatory element of superoxide dismutase 3 (Sod3) gene to repress its expression. Increased levels of the extracellular SOD3 enzyme in Suv4-20h1 mutants increases hydrogen peroxide (H2O2) concentrations, causing vascular defects and impairing alveolarization. Conclusions: Our findings reveal a pivotal role of the histone modifier SUV4-20H1 in cardiopulmonary co-development and uncover developmental origins of cardiopulmonary diseases. We assume that the study will facilitate the understanding of pathogenic events causing PH and COPD, and aid the development of epigenetic drugs for treatment of cardiopulmonary diseases.

Huanglian Jiedu Decoction in the Treatment of the Traditional Chinese Medicine Syndrome "Shanghuo"-An Intervention Study

“Shanghuo” (“excessive internal heat”) is caused by exuberant endogenous fire, which does not have a comprehensive and systematic traditional Chinese medicine theory. In previous study, we had evaluated the therapeutic effect of Huanglian Jiedu Decoction (HLJDD) (granule) on patients with “Shanghuo”, however, the specific mechanism was not clear, which need further exploration. To explain its intervention mechanism, we select 57 patients with oral diseases caused by “Shanghuo” and 20 health volunteers to divide into oral disease group, HLJDD intervention group and healthy control group. Firstly, biochemical indicators before and after HLJDD intervention are detected, such as inflammatory factors, oxidative stress factors and energy metabolism factors. The results exhibit that HLJDD significantly decreases indicators succinic acid (p < 0.001); tumor necrosis factor-alpha, adenosine triphosphate, citric acid (p < 0.01); interleukin-8 (IL-8), 4-hydroxynonenal, pyruvic acid, lactate dehydrogenase (p < 0.05). The levels of glucocorticoid, adrenocorticotropic hormone (p < 0.01); lactic acid, IL-4, IL-10 (p < 0.05) significantly increase after HLJDD intervention. In addition, we adopt multi-omics analysis approach to investigate the potential biomarkers. Nontargeted metabolomics demonstrate that the levels of 7 differential metabolites approach that in the healthy control group after HLJDD intervention, which are correlated with histidine metabolism, beta-alanine metabolism and sphingolipid metabolism through metabolic pathway analysis. Targeted lipidomics results and receiver operating characteristic curve analysis show that 13 differential lipids are identified in the three groups mainly focuse on lysophosphatidylcholines, lysophosphatidylethanolamines. Finally, the network associations of those differential biomarkers reveal the regulation of adenosine triphosphate and tricarboxylic acid cycle play essential role in the therapeutic effect mechanism of HLJDD in “Shanghuo”. The study has laid the foundation for further revealing the mechanism and finding clinical biomarkers related to “Shanghuo”.

Dual Role of Hydrogen Peroxide as an Oxidant in Pneumococcal Pneumonia

Significance:Streptococcus pneumoniae (Spn), a facultative anaerobic Gram-positive human pathogen with increasing rates of penicillin and macrolide resistance, is a major cause of lower respiratory tract infections worldwide. Pneumococci are a primary agent of severe pneumonia in children younger than 5 years and of community-acquired pneumonia in adults. A major defense mechanism toward Spn is the generation of reactive oxygen species, including hydrogen peroxide (H₂O₂), during the oxidative burst of neutrophils and macrophages. Paradoxically, Spn produces high endogenous levels of H₂O₂ as a strategy to promote colonization. Recent Advances: Pneumococci, which express neither catalase nor common regulators of peroxide stress resistance, have developed unique mechanisms to protect themselves from H₂O₂. Spn generates high levels of H₂O₂ as a strategy to promote colonization. Production of H₂O₂ moreover constitutes an important virulence phenotype and its cellular activities overlap and complement those of other virulence factors, such as pneumolysin, in modulating host immune responses and promoting organ injury. Critical Issues: This review examines the dual role of H₂O₂ in pneumococcal pneumonia, from the viewpoint of both the pathogen (defense mechanisms, lytic activity toward competing pathogens, and virulence) and the resulting host-response (inflammasome activation, endoplasmic reticulum stress, and damage to the alveolar-capillary barrier in the lungs). Future Directions: An understanding of the complexity of H₂O₂-mediated host-pathogen interactions is necessary to develop novel strategies that target these processes to enhance lung function during severe pneumonia.

Superoxide dismutase 3 is expressed in bone tissue and required for normal bone homeostasis and mineralization

Superoxide dismutase 3 (SOD3) is an extracellular protein with the capacity to convert superoxide into hydrogen peroxide, an important secondary messenger in redox regulation. To investigate the utility of zebrafish in functional studies of SOD3 and its relevance for redox regulation, we have characterized the zebrafish orthologues; Sod3a and Sod3b. Our analyses show that both recombinant Sod3a and Sod3b express SOD activity, however, only Sod3b is able to bind heparin. Furthermore, RT-PCR analyses reveal that sod3a and sod3b are expressed in zebrafish embryos and are present primarily in separate organs in adult zebrafish, suggesting distinct functions in vivo. Surprisingly, both RT-PCR and whole mount in situ hybridization showed specific expression of sod3b in skeletal tissue. To further investigate this observation, we compared femoral bone obtained from wild-type and SOD3^-/- mice to determine whether a functional difference was apparent in healthy adult mice. Here we report, that bone from SOD3^-/- mice is less mineralized and characterized by significant reduction of cortical and trabecular thickness in addition to reduced mechanical strength. These analyses show that SOD3 plays a hitherto unappreciated role in bone development and homeostasis.

Novel and Converging Ways of NOX2 and SOD3 in Trafficking and Redox Signaling in Macrophages

Macrophages and related tissue macrophage populations use the classical NADPH oxidase (NOX2) for the regulated production of superoxide and derived oxidants for pathogen combat and redox signaling. With an emphasis on macrophages, we discuss how sorting into secretory storage vesicles, agonist-responsive membrane trafficking, and segregation into sphingolipid and cholesterol-enriched microdomains (lipid rafts) determine the subcellular distribution and spatial organization of NOX2 and superoxide dismutase-3 (SOD3). We discuss how inflammatory activation of macrophages, in part through small GTPase Rab27A/B regulation of the secretory compartments, mediates the coalescence of these two proteins on the cell surface to deliver a focalized hydrogen peroxide output. In interplay with membrane-embedded oxidant transporters and redox sensitive target proteins, this arrangement allows for the autocrine and paracrine signaling, which govern macrophage activation states and transcriptional programs. By discussing examples of autocrine and paracrine redox signaling, we highlight why formation of spatiotemporal microenvironments where produced superoxide is rapidly converted to hydrogen peroxide and conveyed immediately to reach redox targets in proximal vicinity is required for efficient redox signaling. Finally, we discuss the recent discovery of macrophage-derived exosomes as vehicles of NOX2 holoenzyme export to other cells.

Airway Redox Homeostasis and Inflammation Gone Awry: From Molecular Pathogenesis to Emerging Therapeutics in Respiratory Pathology

As aerobic organisms, we are continuously and throughout our lifetime subjected to an oxidizing atmosphere and, most often, to environmental threats. The lung is the internal organ most highly exposed to this milieu. Therefore, it has evolved to confront both oxidative stress induced by reactive oxygen species (ROS) and a variety of pollutants, pathogens, and allergens that promote inflammation and can harm the airways to different degrees. Indeed, an excess of ROS, generated intrinsically or from external sources, can imprint direct damage to key structural cell components (nucleic acids, sugars, lipids, and proteins) and indirectly perturb ROS-mediated signaling in lung epithelia, impairing its homeostasis. These early events complemented with efficient recognition of pathogen- or damage-associated recognition patterns by the airway resident cells alert the immune system, which mounts an inflammatory response to remove the hazards, including collateral dead cells and cellular debris, in an attempt to return to homeostatic conditions. Thus, any major or chronic dysregulation of the redox balance, the air-liquid interface, or defects in epithelial proteins impairing mucociliary clearance or other defense systems may lead to airway damage. Here, we review our understanding of the key role of oxidative stress and inflammation in respiratory pathology, and extensively report current and future trends in antioxidant and anti-inflammatory treatments focusing on the following major acute and chronic lung diseases: acute lung injury/respiratory distress syndrome, asthma, chronic obstructive pulmonary disease, pulmonary fibrosis, and cystic fibrosis.

Changes in the Activity and Concentration of Superoxide Dismutase Isoenzymes (Cu/Zn SOD, MnSOD) in the Blood of Healthy Subjects and Patients with Acute Pancreatitis

This study was aimed at evaluating the changes in the concentration and activity of all superoxide dismutase isoenzymes (SOD1, SOD2, SOD3) in the blood of patients with acute pancreatitis (AP) and healthy subjects, taking into account the extracellular (plasma) and intracellular (erythrocyte lysate) compartment. The relationships between the activity/concentration of SODs, metal concentration and the markers of inflammation were evaluated. To assess the pro/antioxidative imbalance, the malonyldialdehyde (MDA) concentration and the value of total antioxidant capacity (TAC) were measured. The impact of single-nucleotide polymorphism (SNP) in the SOD1 gene (rs2070424) on the activity/concentration of SOD1 as the main isoenzyme of the SOD family was also analyzed in this study. The SOD2 activity in erythrocytes was increased compared to plasma: 10-fold in the AP patient group and 5-fold in healthy subjects. The plasma of AP patients showed an increased SOD1 concentration and decreased SOD2 and SOD3 concentrations compared to healthy subjects. The Cu/Zn SOD (SOD1 + SOD3) concentration in plasma of AP patients was elevated compared to healthy subjects, but changes in plasma Cu/Zn SOD (SOD1 + SOD3) activity in the examined groups were not observed. An influence of SNP rs2070424 in the SOD1 gene on the total activity of SOD in AP patients (with AG genotype), accompanied by an increased IL-6 concentration, was observed. In oxidative stress conditions induced by inflammation, the participation of individual forms of plasma SOD isoenzymes in total antioxidative activity of SOD changed. A significant increase in the intracellular SOD1 concentration in plasma of AP patients proves the important role of this isoenzyme in the neutralization of oxidative stress induced by impaired Cu and Zn homeostasis. The presence of increased concentration of SOD2 in erythrocytes of healthy subjects and AP patients confirms the important function of this isoenzyme in the antioxidative defense.

Anti-oxidative effects of superoxide dismutase 3 on inflammatory diseases

Free radicals and other oxidants are critical determinants of the cellular signaling pathways involved in the pathogenesis of several human diseases including inflammatory diseases. Numerous studies have demonstrated the protective effects of antioxidant enzymes during inflammation by elimination of free radicals. The superoxide dismutase (SOD), an antioxidant enzyme, plays an essential pathogenic role in the inflammatory diseases by not only catalyzing the conversion of the superoxide to hydrogen peroxide and oxygen but also affecting immune responses. There are three distinct isoforms of SOD, which distribute in different cellular compartments such as cytosolic SOD1, mitochondrial SOD2, and extracellular SOD3. Many studies have investigated the anti-oxidative effects of SOD3 in the inflammatory diseases. Herein, in this review, we focus on the current understanding of SOD3 as a therapeutic protein in inflammatory diseases such as skin, autoimmune, lung, and cardiovascular inflammatory diseases. Moreover, the mechanism(s) by which SOD3 modulates immune responses and signal initiation in the pathogenesis of the diseases will be further discussed.