We have shown that UVA (320-380 nm) radiation, hydrogen peroxide, and sodium arsenite induce a stress protein of approximately 32 kDa in human skin fibroblasts. The synthesis cloning cDNA from arsenite-induced mRNA populations now allowed us to unequivocally identify the 32-kDa as heme oxygenase. By analysis we oxygenase gene is also induced cultured fibroblasts by cadmium chloride, iodoacetamide, menadione. known antioxidant properties catabolites taken together with observation high level...

Oxidative stress of human skin fibroblasts by treatment with ultraviolet A (UVA) radiation has been shown to lead an increase in levels the heme catabolizing enzyme oxygenase 1 [heme, hydrogen-donor:oxygen oxidoreductase (alpha-methene-oxidizing, hydroxylating), EC 1.14.99.3] and iron storage protein ferritin. Here we show that fibroblasts, preirradiated UVA, sustain less membrane damage during a subsequent exposure UVA than cells had not preirradiated. Pretreating antisense oligonucleotide...

Heme oxygenase-1 mRNA levels increase following exposure of many mammalian cell lines to oxidative stress such as ultraviolet A (UVA) irradiation.Here we demonstrate a 4-fold in microsomal heme oxygenase activity and 40% decrease content 14 h after treatment human skin fibroblasts (FEKJ with 260 kJ m-2 UVA radiation.Paralleling this was 2-fold ferritin that sustained for at least 46 irradiation.Treatment the iron chelating agent desferrioxamine, UVA-dependent induction oxygenase, prevented...

Treatment of cultured human skin fibroblasts with near-UV radiation, hydrogen peroxide, and sodium arsenite induces accumulation heme oxygenase mRNA protein. In this study, these treatments led to a dramatic increase in the rate RNA transcription from gene but had no effect on stability. Transcriptional activation, therefore, appears be major mechanism stimulation expression by either oxidative stress or sulfydryl reagents.

We have analyzed the pattern of protein synthesis in solar near ultraviolet (334 nm, 365 nm) and visible (405 irradiated normal human skin fibroblasts. Two hours after irradiation we find that one major stress approximately 32 kDa is induced cells. This not by radiation at wavelengths shorter than 334 nm inducible heat shock treatment these Although sodium arsenite, diamide, menadione all a 32-kDa protein, they also proteins. In contrast, oxidizing agent, hydrogen peroxide, low molecular...

There is considerable current interest in the cytoprotective effects of natural antioxidants against oxidative stress. In particular, epicatechin, a major member flavanol family polyphenols with powerful antioxidant properties vitro, has been investigated to determine its ability attenuate oxidative-stress-induced cell damage and understand mechanism protective action. We have induced stress cultured human fibroblasts using hydrogen peroxide examined cellular responses form mitochondrial...

In mammalian cells, the level of iron-storage protein ferritin (Ft) is tightly controlled by iron-regulatory protein-1 (IRP-1) at posttranscriptional level. This regulation prevents iron acting as a catalyst in reactions between reactive oxygen species and biomolecules. The ultraviolet A (UVA) radiation component sunlight (320–400 nm) has been shown to be source oxidative stress skin via generation species. We report here that exposure human primary fibroblasts, FEK4, UVA causes an immediate...

We have examined the role of nucleus and membrane in activation nuclear factor (NF)-kappa B by oxidant stress generated via UVA (320-380 nm) component solar radiation. Nuclear extracts from human skin fibroblasts that had been irradiated with at doses caused little DNA damage contained activated NF-kappa bound to its recognition sequence DNA. The radiation-dependent enucleated cells confirmed was not involved. On other hand, appeared be correlated damage, could prevented alpha-tocopherol...

Abstract— Glutathione depletion of cultured human skin fibroblasts by treatment with buthionine‐S,R‐sulfoximine (BSO) sensitises them to radiation at a series defined wavelengths throughout the solar UV range. We now show that there is close quantitative correlation between cellular glutathione content (as depleted BSO) and sensitivity 365 nm. A weaker observed when cells are using diethylmaleimide. Both epidermal keratinocytes derived from same foreskin biopsy sensitised 313 nm depletion....

The induction of heme oxygenase by both hydrogen peroxide and UVA (365 nm) radiation in normal human skin flbro blasts is prevented prior treatment cells with the specific iron chelators, o-phenanthroline or desferrioxamine. In addition, chelators protected against lethal effects H irradiation. We propose that generation highly reactive hydroxyl radical an catalyzed Fenton reaction involved this stress response and, at least part, cell killing two treatments. These results are also...

Abstract— The colony‐forming ability of Chinese hamster cells (V‐79) and HeLa has been measured after near‐ultraviolet (UV) irradiation, predominantly at 365 nm. To avoid the production toxic photoproducts, were irradiated in an inorganic buffer rather than tissue culture medium. Under these circumstances near‐UV lethality was strongly oxygen‐dependent. Both cell lines approximately 10 4 times more sensitive to 254 nm irradiation radiation when aerobically. Pretreatment with 6 5 Jm ‐2...

Abstract —Irradiation at 365 nm results in the induction of approximately 2–4 times 10 ‐6 and 1‐2times single‐strand breaks (alkali‐labile bonds) per 8 daltons J m ‐2 extracted phage T4 DNA Escherichia coli bacterial DNA, respectively. The rate break intact is one‐fourth that for DNA. 2‐aminoethylisothiouronium bromide‐HBr protects against both systems. No are induced bacteria irradiated under anaerobic conditions over dose range tested. Possible mechanisms suggested. Consideration given to...

Abstract Both the UVB (290‐320 nm) and UVA (320‐380 regions of sunlight damage human skin cells but, particularly at longer wavelengths, information is scant concerning mechanism(s) induction roles cellular defense mechanisms. Following extensive glutathione depletion cultured fibroblasts, become strongly sensitized to cytotoxic action near‐visible (405 nm), (334 nm, 365 (313 but not UVC (254 radiations. In critical region, magnitude protection afforded by endogenous approaches that provided...