Corneal alkali burns are potentially blinding injuries. Alkali induces oxidative stress in corneas followed by excessive corneal inflammation, neovascularization, and untransparent scar formation. Molecular hydrogen (H2), a potent reactive oxygen species (ROS) scavenger, suppresses oxidative stress and enables corneal healing when applied on the corneal surface. The purpose of this study was to examine whether the H2 pretreatment of healthy corneas evokes a protective effect against corneal alkali-induced oxidative stress. Rabbit eyes were pretreated with a H2 solution or buffer solution, by drops onto the ocular surface, and the corneas were then burned with 0.25 M NaOH. The results obtained with immunohistochemistry and pachymetry showed that in the corneas of H2-pretreated eyes, slight oxidative stress appeared followed by an increased expression of antioxidant enzymes. When these corneas were postburned with alkali, the alkali-induced oxidative stress was suppressed. This was in contrast to postburned buffer-pretreated corneas, where the oxidative stress was strong. These corneas healed with scar formation and neovascularization, whereas corneas of H2-pretreated eyes healed with restoration of transparency in the majority of cases. Corneal neovascularization was strongly suppressed. Our results suggest that the corneal alkali-induced oxidative stress was reduced via the increased antioxidant capacity of corneal cells against reactive oxygen species (ROS). It is further suggested that the ability of H2 to induce the increase in antioxidant cell capacity is important for eye protection against various diseases or external influences associated with ROS production.

• MeSH
• alkálie toxicita   MeSH
• antioxidancia metabolismus   MeSH
• chemické popálení farmakoterapie   metabolismus   patologie   MeSH
• epitelové buňky účinky léků   metabolismus   patologie   MeSH
• hojení ran účinky léků   MeSH
• králíci MeSH
• modely nemocí na zvířatech MeSH
• neovaskularizace rohovky prevence a kontrola   MeSH
• oxidační stres účinky léků   MeSH
• popálení oka chemicky indukované   farmakoterapie   metabolismus   patologie   MeSH
• reaktivní formy kyslíku metabolismus   MeSH
• rohovka krevní zásobení   účinky léků   metabolismus   patologie   MeSH
• vodík farmakologie   terapeutické užití   MeSH
• zvířata MeSH
• Check Tag
• králíci MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• publikace stažené z tisku MeSH
• Názvy látek
• alkálie MeSH
• antioxidancia MeSH
• reaktivní formy kyslíku MeSH
• vodík MeSH

Our previous research revealed that trehalose, a nonreducing disaccharide of glucose and an important stress responsive factor, proved to have anti-inflammatory, antiapoptotic, and particularly antioxidant properties in UVB-irradiated corneas. Trehalose reduced oxidative stress in corneas induced by UVB irradiation, by means of a decrease in the antioxidant/prooxidant imbalance in the corneal epithelium. In this study, we demonstrate that trehalose of 3% or 6% concentration in eye drops directly decreases oxidative stress in UVB-irradiated corneas, by removing the excessive amount of reactive oxygen species (ROS). Trehalose drops applied on corneas during UVB irradiation once daily for four days resulted in a reduction or even absence of the oxidative stress, DNA damage, and peroxynitrite formation (detected by nitrotyrosine residues), seen in buffer-treated corneas. Furthermore, trehalose treatment applied curatively after repeated irradiation for the subsequent fourteen days led to the renewal of corneal transparency and significant suppression or even absence of neovascularization. This was in contrast to buffer-treated irradiated corneas, where the intracorneal inflammation was developed and the untransparent corneas were vascularized. In conclusion, the treatment of UVB-irradiated corneas with trehalose eye drops removed the excessive amount of ROS in the corneal epithelium, leading to the suppression of oxidative stress and favorable corneal healing. The 6% trehalose showed a higher intensive antioxidant effect.

• MeSH
• hojení ran účinky léků   účinky záření   MeSH
• interleukin-1beta metabolismus   MeSH
• keratiny metabolismus   MeSH
• králíci MeSH
• oxidační stres * účinky léků   účinky záření   MeSH
• poranění rohovky farmakoterapie   MeSH
• poškození DNA MeSH
• reaktivní formy kyslíku metabolismus   MeSH
• reepitalizace účinky léků   účinky záření   MeSH
• rohovka účinky léků   patologie   účinky záření   MeSH
• synthasa oxidu dusnatého, typ II metabolismus   MeSH
• trehalosa farmakologie   terapeutické užití   MeSH
• tyrosin analogy a deriváty   metabolismus   MeSH
• ultrafialové záření * MeSH
• vaskulární endoteliální růstový faktor A metabolismus   MeSH
• zvířata MeSH
• Check Tag
• králíci MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• publikace stažené z tisku MeSH
• Názvy látek
• 3-nitrotyrosine MeSH Prohlížeč
• interleukin-1beta MeSH
• keratiny MeSH
• reaktivní formy kyslíku MeSH
• synthasa oxidu dusnatého, typ II MeSH
• trehalosa MeSH
• tyrosin MeSH
• vaskulární endoteliální růstový faktor A MeSH

The aim of this study is to examine whether molecular hydrogen (H2) is able to reduce oxidative stress after corneal damage induced by UVB irradiation. We previously found that UVB irradiation of the cornea caused the imbalance between the antioxidant and prooxidant enzymes in the corneal epithelium, followed by the imbalance between metalloproteinases and their physiological inhibitors (imbalances in favour of prooxidants and metalloproteinases) contributing to oxidative stress and development of the intracorneal inflammation. Here we investigate the effect of H2 dissolved in PBS in the concentration 0.5 ppm wt/vol, applied on rabbit corneas during UVB irradiation and healing (UVB doses 1.01 J/cm2 once daily for four days). Some irradiated corneas remained untreated or buffer treated. In these corneas the oxidative stress appeared, followed by the excessive inflammation. Malondiladehyde and peroxynitrite expressions were present. The corneas healed with scar formation and neovascularization. In contrast, in H2 treated irradiated corneas oxidative stress was suppressed and malondiladehyde and peroxynitrite expressions were absent. The corneas healed with the restoration of transparency. The study provides the first evidence of the role of H2 in prevention of oxidative and nitrosative stress in UVB irradiated corneas, which may represent a novel prophylactic approach to corneal photodamage.

• MeSH
• králíci MeSH
• kyselina peroxydusitá metabolismus   MeSH
• malondialdehyd metabolismus   MeSH
• oxidační stres účinky léků   účinky záření   MeSH
• poranění rohovky farmakoterapie   metabolismus   MeSH
• reaktivní formy kyslíku metabolismus   MeSH
• rohovka účinky léků   metabolismus   účinky záření   MeSH
• ultrafialové záření * MeSH
• vodík terapeutické užití   MeSH
• zvířata MeSH
• Check Tag
• králíci MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• publikace stažené z tisku MeSH
• Názvy látek
• kyselina peroxydusitá MeSH
• malondialdehyd MeSH
• reaktivní formy kyslíku MeSH
• vodík MeSH

The aim of this study was to examine whether mesenchymal stem cells (MSCs) and/or corneal limbal epithelial stem cells (LSCs) influence restoration of an antioxidant protective mechanism in the corneal epithelium and renewal of corneal optical properties changed after alkali burns. The injured rabbit corneas (with 0.25 N NaOH) were untreated or treated with nanofiber scaffolds free of stem cells, with nanofiber scaffolds seeded with bone marrow MSCs (BM-MSCs), with adipose tissue MSCs (Ad-MSCs), or with LSCs. On day 15 following the injury, after BM-MSCs or LSCs nanofiber treatment (less after Ad-MSCs treatment) the expression of antioxidant enzymes was restored in the regenerated corneal epithelium and the expressions of matrix metalloproteinase 9 (MMP9), inducible nitric oxide synthase (iNOS), α-smooth muscle actin (α-SMA), transforming growth factor-β1 (TGF-β1), and vascular endothelial factor (VEGF) were low. The central corneal thickness (taken as an index of corneal hydration) increased after the injury and returned to levels before the injury. In injured untreated corneas the epithelium was absent and numerous cells revealed the expressions of iNOS, MMP9, α-SMA, TGF-β1, and VEGF. In conclusion, stem cell treatment accelerated regeneration of the corneal epithelium, restored the antioxidant protective mechanism, and renewed corneal optical properties.

• MeSH
• alkálie MeSH
• antioxidancia terapeutické užití   MeSH
• buněčná diferenciace účinky léků   MeSH
• chemické popálení enzymologie   genetika   patologie   terapie   MeSH
• imunohistochemie MeSH
• králíci MeSH
• limbus corneae cytologie   MeSH
• matrixová metaloproteinasa 9 metabolismus   MeSH
• mezenchymální kmenové buňky cytologie   účinky léků   MeSH
• ochranné látky farmakologie   terapeutické užití   MeSH
• pachymetrie rohovky MeSH
• regulace genové exprese účinky léků   MeSH
• rohovkový epitel patologie   MeSH
• superoxiddismutasa metabolismus   MeSH
• synthasa oxidu dusnatého, typ II metabolismus   MeSH
• transformující růstový faktor beta genetika   metabolismus   MeSH
• transplantace mezenchymálních kmenových buněk * MeSH
• tukové buňky cytologie   účinky léků   MeSH
• vaskulární endoteliální růstový faktor A metabolismus   MeSH
• zákal rohovky komplikace   terapie   MeSH
• zvířata MeSH
• Check Tag
• králíci MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• publikace stažené z tisku MeSH
• Názvy látek
• alkálie MeSH
• antioxidancia MeSH
• matrixová metaloproteinasa 9 MeSH
• ochranné látky MeSH
• superoxiddismutasa MeSH
• synthasa oxidu dusnatého, typ II MeSH
• transformující růstový faktor beta MeSH
• vaskulární endoteliální růstový faktor A MeSH

Oxidative stress is involved in many ocular diseases and injuries. The imbalance between oxidants and antioxidants in favour of oxidants (oxidative stress) leads to the damage and may be highly involved in ocular aging processes. The anterior eye segment and mainly the cornea are directly exposed to noxae of external environment, such as air pollution, radiation, cigarette smoke, vapors or gases from household cleaning products, chemical burns from splashes of industrial chemicals, and danger from potential oxidative damage evoked by them. Oxidative stress may initiate or develop ocular injury resulting in decreased visual acuity or even vision loss. The role of oxidative stress in the pathogenesis of ocular diseases with particular attention to oxidative stress in the cornea and changes in corneal optical properties are discussed. Advances in the treatment of corneal oxidative injuries or diseases are shown.

• MeSH
• alkálie toxicita   MeSH
• oční roztoky terapeutické užití   MeSH
• oxidační stres * účinky léků   účinky záření   MeSH
• poranění rohovky farmakoterapie   metabolismus   patologie   MeSH
• reaktivní formy kyslíku metabolismus   MeSH
• rohovka účinky léků   účinky záření   MeSH
• ultrafialové záření MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH
• Názvy látek
• alkálie MeSH
• oční roztoky MeSH
• reaktivní formy kyslíku MeSH

BACKGROUND: Trehalose, a nonreducing disaccharide of glucose, is synthesized as a stress response factor when cells are exposed to stressful conditions. In the cornea, oxidative stress plays the key role in the development of acute corneal inflammatory response to UVB rays, photokeratitis. We found previously that trehalose reduced UVB-induced oxidative effects on the formation of cytotoxic peroxynitrite, apoptotic corneal epithelial cell death and changes in corneal optics. The aim of the present study was to examine whether trehalose might inhibit UVB-mediated proinflammatory cytokine and matrix metalloproteinase induction and the development of an antioxidant/pro-oxidant imbalance in the corneal epithelium, changes found previously to be strongly involved in the acute corneal UVB-induced inflammation. The expression of heat shock protein 70 as a potential biomarker for corneal UVB-induced damage was also examined. METHODS: The corneas of New Zealand white rabbits were irradiated with UVB rays, 312 nm, daily dose of 0.5 J/cm(2) for 4 days. During the irradiation, trehalose drops were applied on the right eye and buffered saline on the left eye. One day after the end of irradiations, the animals were killed and the corneas examined immunohistochemically for the expression of antioxidant enzymes (catalase, superoxide dismutase, glutathione peroxidase), pro-oxidant xanthine oxidoreductase/xanthine oxidase, proinflammatory cytokines (interleukin-6, interleukin-8), matrix metalloproteinase-9 and heat shock protein 70. RESULTS: After buffered saline treatment during UVB irradiation, an antioxidant/pro-oxidant imbalance appeared in the corneal epithelium: The expression of antioxidant enzymes was highly reduced, whereas the expression of pro-oxidant xanthine oxidase was increased. The pronounced expression of pro-inflammatory cytokines, matrix metalloproteinase and heat shock protein 70 was found in the UVB-irradiated corneal epithelium. Trehalose application significantly suppressed all the above-mentioned UVB-induced corneal disturbances. CONCLUSIONS: Trehalose favorably influenced the oxidative damage of the cornea caused by UVB rays. Trehalose suppressed proinflammatory cytokine induction. It is suggested that suppression of proinflammatory cytokines contributed strongly to reduced matrix metalloproteinase and xanthine oxidase expression in the UVB-irradiated corneal epithelium and to the decreased development of an antioxidant/pro-oxidant imbalance. The overexpression of heat shock protein 70 found in UVB-irradiated cornea after buffered saline treatment was reduced after trehalose application.

• MeSH
• antioxidancia MeSH
• biologické markery metabolismus   MeSH
• cytokiny metabolismus   MeSH
• experimentální radiační poranění farmakoterapie   enzymologie   MeSH
• imunoenzymatické techniky MeSH
• králíci MeSH
• matrixová metaloproteinasa 9 metabolismus   MeSH
• oxidační stres účinky léků   MeSH
• oxidancia MeSH
• oxidoreduktasy metabolismus   MeSH
• počítačové zpracování obrazu MeSH
• proteiny tepelného šoku HSP70 metabolismus   MeSH
• reaktivní formy kyslíku metabolismus   MeSH
• rohovkový epitel enzymologie   účinky záření   MeSH
• trehalosa farmakologie   MeSH
• ultrafialové záření škodlivé účinky   MeSH
• zvířata MeSH
• Check Tag
• králíci MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• antioxidancia MeSH
• biologické markery MeSH
• cytokiny MeSH
• matrixová metaloproteinasa 9 MeSH
• oxidancia MeSH
• oxidoreduktasy MeSH
• proteiny tepelného šoku HSP70 MeSH
• reaktivní formy kyslíku MeSH
• trehalosa MeSH

PURPOSE: Normal corneal hydration is necessary for the maintenance of corneal transparency. Damage of the corneal epithelium or endothelium by various external influences disturbs the mechanism by which the cornea maintains normal hydration and transparency. The cornea swells, and the corneal thickness increases, resulting in increased scatter and the development of corneal opacity. The transmission of light across the cornea is changed. The purpose of this study is to investigate spectrophotometrically the corneal light transmission under the influence of the various factors affecting the cornea. METHODS: We developed a spectrophotometric method to measure the light transmission across the cornea under the influence of various factors affecting the cornea, such as treatment with 0.9% NaCl, saline, or phosphate buffered saline (PBS), solutions employed as placebo eye drops (negative controls) in experimental studies, agents toxic to the cornea, such as diluted acids or alkalis. The method distinguishes between changes in corneal light transmission caused by altered corneal thickness (the level of hydration) and changes resulting from other corneal disturbances which in turn affect corneal light transmission. RESULTS: The results obtained show that the corneal light transmission is decreased following the application of toxic substances on the corneal surface. This decrease is highly dependent on the severity of the corneal injury evoked by individual noxes, and the resulting changes in corneal hydration and transparency. CONCLUSIONS: The influence of various influences applied to the cornea, manifested as changes in corneal light transmission, can be measured using our spectrophotometric method with a high degree of sensitivity.

• MeSH
• edém rohovky chemicky indukované   MeSH
• hydroxid sodný toxicita   MeSH
• králíci MeSH
• kyselina chlorovodíková toxicita   MeSH
• rohovka účinky léků   účinky záření   MeSH
• spektrofotometrie MeSH
• světlo * MeSH
• zvířata MeSH
• Check Tag
• králíci MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• hydroxid sodný MeSH
• kyselina chlorovodíková MeSH