Sustained lung activity of a novel chimeric protein, SOD2/3, after intratracheal administration

Superoxide dismutase secreting Bacillus amyloliquefaciens spores attenuate pulmonary fibrosis

Superoxide dismutase (SOD) can convert active oxygen to oxygen or hydrogen peroxide, and recent research has suggested that it can protect against lung damage and fibrosis. Clinical applications based on SOD remain limited however due to costs and low stability. We here investigated a potential new therapeutic delivery system for this enzyme in the form of SOD-overexpressing Bacillus amyloliquefaciens spores which we introduced into a bleomycin-induced pulmonary fibrosis mouse model. This treatment significantly alleviated the disease, as quantified using a hydroxyproline assay, at 107 colony forming unit (CFU) of Bacillus spores per day. Exposure of the mice to the spores was further found to decrease the lung mRNA levels of CTGF, Col1a1, α-SMA, TGF-β, TNF-α, and IL-6, and the protein levels of TGF-β, Smad2/3, αSMA and Col1a1, all major indicators of pulmonary fibrosis. Survival benefits, and reduced byproducts of lipid peroxidase such as malondialdehyde and 4-hydroxynen, were also noted in the treated animals. The beneficial effects of these Bacillus spores on pulmonary fibrosis were further found to be greater than the equivalent free SOD concentration. Immunofluorescence staining of primary pulmonary fibroblasts extracted from the bleomycin-induced model showed decreased αSMA expression following the in vivo treatment with SOD-overexpressing Bacillus. Our treatment approach SOD through Bacillus spores shows beneficial effects against pulmonary fibrosis, combined with the suppression of the SMAD/TGF-β pathway, suggesting that it is an effective novel delivery route for antioxidants.

Oral delivery of a highly stable superoxide dismutase as a skin aging inhibitor

As an effective antioxidant enzyme, superoxide dismutase (SOD) has been widely used as a food supplement, cosmetic additive, and therapeutic agent. However, oral delivery of SOD is challenging due to its relative instability, limited bioavailability, and low absorption efficiency in the gastrointestinal (GI) tract. We addressed these issues using a highly stable superoxide dismutase (hsSOD) generated from a hot spring microbial sample. This SOD exhibited a specific activity of 5000 IU/mg while retaining its enzymatic activity under low pH environments of an artificial GI system and in the presence of surfactants and various proteolytic enzymes. The inhibitory effects of hsSOD against skin-aging was evaluated under both in vitro and in vivo experiments using fibroblast cell and D-galactose induced aging-mouse models, respectively. Effective oral delivery of hsSOD promises wide applicability in pharmaceutical and food industries.

Actein alleviates 2,3,7,8-tetrachlorodibenzo-p-dioxin-mediated cellular dysfunction in osteoblastic MC3T3-E1 cells

The environmental pollutant 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) is known to affect bone metabolism. We evaluated the protective effects of the triterpene glycoside actein from the herb black cohosh against TCDD-induced toxicity in MC3T3-E1 osteoblastic cells. We found that TCDD significantly reduced cell viability and increased apoptosis and autophagy in MC3T3-E1 osteoblastic cells (P < .05). In addition, TCDD treatment resulted in a significant increase in intracellular calcium concentration, mitochondrial membrane potential collapse, reactive oxygen species (ROS) production, and cardiolipin peroxidation, whereas pretreatment with actein significantly mitigated these effects (P < .05). The effects of TCDD on extracellular signal-related kinase (ERK), aryl hydrocarbon receptor, aryl hydrocarbon receptor repressor, and cytochrome P450 1A1 levels in MC3T3-E1 cells were significantly inhibited by actein. The levels of superoxide dismutase, ERK1, and nuclear factor kappa B mRNA were also effectively restored by pretreatment with actein. Furthermore, actein treatment resulted in a significant increase in alkaline phosphatase (ALP) activity and collagen content, as well as in the expression of genes associated with osteoblastic differentiation (ALP, type I collagen, osteoprotegerin, bone sialoprotein, and osterix). This study demonstrates the underlying molecular mechanisms of cytoprotection exerted by actein against TCDD-induced oxidative stress and osteoblast damage.

Cocktail of Superoxide Dismutase and Fasudil Encapsulated in Targeted Liposomes Slows PAH Progression at a Reduced Dosing Frequency

Currently, two or more pulmonary vasodilators are used to treat pulmonary arterial hypertension (PAH), but conventional vasodilators alone cannot reverse disease progression. In this study, we tested the hypothesis that a combination therapy comprising a vasodilator plus a therapeutic agent that slows pulmonary arterial remodeling and right heart hypertrophy is an efficacious alternative to current vasodilator-based PAH therapy. Thus, we encapsulated a cocktail of superoxide dismutase (SOD), a superoxide scavenger, and fasudil, a specific rho-kinase inhibitor, into a liposomal formulation equipped with a homing peptide, CAR. We evaluated the effect of the formulations on pulmonary hemodynamics in monocrotaline-induced PAH rats (MCT-induced PAH) and assessed the formulation's efficacy in slowing the disease progression in Sugen-5416/hypoxia-induced PAH rats (SU/hypoxia-induced PAH). For acute studies, we monitored both mean pulmonary and systemic arterial pressures (mPAP and mSAP) for 2 to 6 h after a single dose of the plain drugs or formulations. In chronic studies, PAH rats received plain drugs every 48 h and the formulations every 72 h for 21 days. In MCT-induced PAH rats, CAR-modified liposomes containing fasudil plus SOD elicited a more pronounced, prolonged, and selective reduction in mPAP than unmodified liposomes and plain drugs did. In SU/hypoxia-induced PAH rats, the formulation produced a >50% reduction in mPAP and slowed right ventricular hypertrophy. When compared with individual plain drugs or combination, CAR-modified-liposomes containing both drugs reduced the extent of collagen deposition, muscularization of arteries, increased SOD levels in the lungs, and decreased the expression of pSTAT-3 and p-MYPT1. Overall, CAR-modified-liposomes of SOD plus fasudil, given every 72 h, was as efficacious as plain drugs, given every 48 h, suggesting that the formulation can reduce the total drug intake, systemic exposures, and dosing frequency.

Role of reactive oxygen species in neonatal pulmonary vascular disease

SIGNIFICANCE

Abnormal lung development in the perinatal period can result in severe neonatal complications, including persistent pulmonary hypertension (PH) of the newborn and bronchopulmonary dysplasia. Reactive oxygen species (ROS) play a substantive role in the development of PH associated with these diseases. ROS impair the normal pulmonary artery (PA) relaxation in response to vasodilators, and ROS are also implicated in pulmonary arterial remodeling, both of which can increase the severity of PH.

RECENT ADVANCES

PA ROS levels are elevated when endogenous ROS-generating enzymes are activated and/or when endogenous ROS scavengers are inactivated. Animal models have provided valuable insights into ROS generators and scavengers that are dysregulated in different forms of neonatal PH, thus identifying potential therapeutic targets.

CRITICAL ISSUES

General antioxidant therapy has proved ineffective in reversing PH, suggesting that it is necessary to target specific signaling pathways for successful therapy.

FUTURE DIRECTIONS

Development of novel selective pharmacologic inhibitors along with nonantioxidant therapies may improve the treatment outcomes of patients with PH, while further investigation of the underlying mechanisms may enable earlier detection of the disease.

Oxidative Stress and Therapeutic Development in Lung Diseases

Oxidative stress has many implications in the pathogenesis of lung diseases. In this review, we provide an overview of Reactive Oxygen Species (ROS) and nitrogen (RNS) species and antioxidants, how they relate to normal physiological function and the pathophysiology of different lung diseases, and therapeutic strategies. The production of ROS/RNS from endogenous and exogenous sources is first discussed, followed by antioxidant systems that restore oxidative balance and cellular homeostasis. The contribution of oxidant/antioxidant imbalance in lung disease pathogenesis is also discussed. An overview of therapeutic strategies is provided, such as augmenting NO bioactivity, blocking the production of ROS/RNS and replacement of deficient antioxidants. The limitations of current strategies and failures of clinical trials are then addressed, followed by discussion of novel experimental approaches for the development of improved antioxidant therapies.

Regulation of lung oxidative damage by endogenous superoxide dismutase in sepsis

Background

The purpose of this research is to study the relationship between superoxide dismutase (SOD) and lung redox state in an animal model of sepsis.

Methods

Sepsis was induced in rats by the cecal ligation and perforation model (CLP). After 3, 6, and 12 h, CLP protein content and expression of SOD1, SOD2, and SOD3 were evaluated, and SOD activity was assessed. Oxidative damage was determined by quantifying nitrotyrosine content. Lung localization of SOD3 was performed by immunohistochemistry. The protective effect of a SOD mimetic on oxidative damage, inflammation, and lung permeability was assessed 12 and 24 h after sepsis induction.

Results

Lung levels of SOD1 decreased 3 and 12 h after sepsis, but SOD2 and SOD3 increased, as well as SOD activity. These alterations were not associated with changes in sod gene expression. Nitrotyrosine levels increased 3 and 12 h after sepsis. The administration of a SOD mimetic decreased nitrotyrosine and proinflammatory cytokine levels and improved lung permeability.

Conclusions

SOD2 and SOD3 increased after sepsis induction, but this was insufficient to protect the lung. Treatments based on SOD mimetics could have a role in lung injury associated with sepsis.

Superoxide dismutase administration, a potential therapy against oxidative stress related diseases: several routes of supplementation and proposal of an original mechanism of action

Oxidative stress, involved in many diseases, is defined as an impaired balance between reactive oxygen species (ROS) production and antioxidant defences. Antioxidant enzymes such as superoxide dismutase (SOD) play a key role in diminishing oxidative stress. Thus, the removal of ROS by exogenous SODs could be an effective preventive strategy against various diseases. The poor bioavailability of exogenous SODs has been criticized. However, improvements in SOD formulation may overcome this limitation and boost interest in its therapeutic properties. Here, we provide a review of animal and human studies about SODs supplementation in order to evaluate their therapeutic value. Protective effects have been observed against irradiation, carcinogenesis, apoptosis and neurodegeneration. SODs administration has also been reported to alleviate inflammatory, infectious, respiratory, metabolic and cardiovascular diseases and genitourinary and fertility disorders, raising the question of its mechanism of action in these diverse situations. Some authors have shown an increase in endogenous antioxidant enzymes after exogenous SODs administration. The induction of endogenous antioxidant defence and, consequently, a decrease in oxidative stress, could explain all the effects observed. Further investigations need to be carried out to test the hypothesis that SODs supplementation acts by inducing an endogenous antioxidant defence.

Pharmacological antioxidant strategies as therapeutic interventions for COPD

Cigarette/tobacco smoke/biomass fuel-induced oxidative and aldehyde/carbonyl stress are intimately associated with the progression and exacerbation of chronic obstructive pulmonary disease (COPD). Therefore, targeting systemic and local oxidative stress with antioxidants/redox modulating agents, or boosting the endogenous levels of antioxidants are likely to have beneficial effects in the treatment/management of COPD. Various antioxidant agents, such as thiol molecules (glutathione and mucolytic drugs, such as N-acetyl-L-cysteine and N-acystelyn, erdosteine, fudosteine, ergothioneine, and carbocysteine), have been reported to modulate various cellular and biochemical aspects of COPD. These antioxidants have been found to scavenge and detoxify free radicals and oxidants, regulate of glutathione biosynthesis, control nuclear factor-kappaB (NF-kappaB) activation, and hence inhibiting inflammatory gene expression. Synthetic molecules, such as specific spin traps like α-phenyl-N-tert-butyl nitrone, a catalytic antioxidant (ECSOD mimetic), porphyrins (AEOL 10150 and AEOL 10113), and a superoxide dismutase mimetic M40419, iNOS and myeloperoxidase inhibitors, lipid peroxidation inhibitors/blockers edaravone, and lazaroids/tirilazad have also been shown to have beneficial effects by inhibiting cigarette smoke-induced inflammatory responses and other carbonyl/oxidative stress-induced cellular alterations. A variety of oxidants, free radicals, and carbonyls/aldehydes are implicated in the pathogenesis of COPD, it is therefore, possible that therapeutic administration or supplementation of multiple antioxidants and/or boosting the endogenous levels of antioxidants will be beneficial in the treatment of COPD. This review discusses various novel pharmacological approaches adopted to enhance lung antioxidant levels, and various emerging beneficial and/or prophylactic effects of antioxidant therapeutics in halting or intervening the progression of COPD. This article is part of a Special Issue entitled: Antioxidants and Antioxidant Treatment in Disease.

Catalase and superoxide dismutase conjugated with platelet-endothelial cell adhesion molecule antibody distinctly alleviate abnormal endothelial permeability caused by exogenous reactive oxygen species and vascular endothelial growth factor

Reactive oxygen species (ROS) superoxide anion (O(2)()) and hydrogen peroxide (H(2)O(2)) produced by activated leukocytes and endothelial cells in sites of inflammation or ischemia cause endothelial barrier dysfunction that may lead to tissue edema. Antioxidant enzymes (AOEs) catalase and superoxide dismutase (SOD) conjugated with antibodies to platelet-endothelial cell adhesion molecule-1 (PECAM-1) specifically bind to endothelium, quench the corresponding ROS, and alleviate vascular oxidative stress and inflammation. In the present work, we studied the effects of anti-PECAM/catalase and anti-PECAM/SOD conjugates on the abnormal permeability manifested by transendothelial electrical resistance decline, increased fluorescein isothiocyanate-dextran influx, and redistribution of vascular endothelial-cadherin in human umbilical vein endothelial cell (HUVEC) monolayers. Anti-PECAM/catalase protected HUVEC monolayers against H(2)O(2)-induced endothelial barrier dysfunction. Polyethylene glycol-conjugated catalase exerted orders of magnitude lower endothelial uptake and no protective effect, similarly to IgG/catalase. Anti-PECAM/catalase, but not anti-PECAM/SOD, alleviated endothelial hyperpermeability caused by exposure to hypoxanthine/xanthine oxidase, implicating primarily H(2)O(2) in the disruption of the endothelial barrier in this model. Thrombin-induced endothelial permeability was not affected by treatment with anti-PECAM/AOEs or the NADPH oxidase inhibitor apocynin or overexpression of AOEs, indicating that the endogenous ROS play no key role in thrombin-mediated endothelial barrier dysfunction. In contrast, anti-PECAM/SOD, but not anti-PECAM/catalase, inhibited a vascular endothelial growth factor (VEGF)-induced increase in endothelial permeability, identifying a key role of endogenous O(2)() in the VEGF-mediated regulation of endothelial barrier function. Therefore, AOEs targeted to endothelial cells provide versatile molecular tools for testing the roles of specific ROS in vascular pathology and may be translated into remedies for these ROS-induced abnormalities.