Characterization of Glutathione S-Transferase in Cultured Human Keratinocytes

Blacker, Kerry L.; Olson, Eric R.; Vessey, Donald A.; Boyer, Thomas D.

doi:10.1111/1523-1747.ep12481276

Cited by 31 publications

(18 citation statements)

References 27 publications

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“…A possible explanation may be that following transport through the cytoplasmic membrane, CTP1 binds to cytoplasmic proteins. This assumption is supported by the fact that indocyanine green, another dye known to be a photosensitizer, is bound to gluthathione Stransferase, as shown in hepatocytes, and the fluorescence signals of indocyanine green were also found in the cytosols of keratinocytes and were not colocalized in lysosomes or mitochondria (2,10,53). In contrast to these findings for CTP1, the fluorescence signals of XF70 and XF73 were colocalized with the mitochondria.…”

Section: Discussionmentioning

confidence: 94%

Photodynamic Effects of Novel XF Porphyrin Derivatives on Prokaryotic and Eukaryotic Cells

Maisch¹,

Bosl²,

Szeimies³

et al. 2005

Antimicrob Agents Chemother

212

138

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The worldwide rise in the rates of antibiotic resistance of bacteria underlines the need for alternative antibacterial agents. A promising approach to the killing of gram-positive antibiotic-resistant bacteria of the skin uses light in combination with a photosensitizer to induce a phototoxic reaction. Different concentrations (0 to 100 M) of porphyrin-based photosensitizers (CTP1, XF70, and XF73) and different incubation times (5 min, 1 h, and 4 h) were used to determine phototoxicity against two methicillin-resistant Staphylococcus aureus strains, one methicillin-sensitive S. aureus strain, one methicillin-resistant Staphylococcus epidermidis strain, one Escherichia coli strain, and human keratinocytes and fibroblasts. Incubation with 0.005 M XF70 or XF73, followed by illumination, yielded a 3-log 10 (>99.9%) decrease in the viable cell numbers of all staphylococcal strains, indicating that the XF drugs have high degrees of potency against gram-positive bacteria and also that the activities of these novel drugs are independent of the antibiotic resistance pattern of the staphylococci examined. CTP1 was less potent against the staphylococci under the same conditions. At 0.005 M, XF70 and XF73 demonstrated no toxicity toward fibroblasts or keratinocytes. No inactivation of E. coli was detected at this concentration. XF73 was confirmed to act via a reactive oxygen species from the results of studies with sodium azide (a quencher of singlet oxygen), which reduced the killing of both eukaryotic and prokaryotic cells. When a quencher of superoxide anion and the hydroxyl radical was used, cell killing was not inhibited. These results demonstrate that the porphyrin-based photosensitizers had concentration-dependent differences in their efficacies of killing of methicillin-resistant staphylococcal strains via reactive oxygen species without harming eukaryotic cells at the same concentrations.

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Section: Discussionmentioning

confidence: 94%

Photodynamic Effects of Novel XF Porphyrin Derivatives on Prokaryotic and Eukaryotic Cells

Maisch¹,

Bosl²,

Szeimies³

et al. 2005

Antimicrob Agents Chemother

212

138

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“…The specific activity in whole human skin cytosol using CDNB as substrate was 25.82 B 1.95 compared to 59.5 B 3.91 nmol/min/mg protein for rat skin. Blacker et al [13] have suggested that the · isozyme found in whole human skin is from the dermis as they could demonstrate only the presence of the  form in human keratinocytes even after applying classical inducers of the · and Ì forms. The activity in human keratinocyte cultures increases with the degree of confluence, and by implication the degree of differentiation to 0.718 B 0.095 Ìmol/min/mg protein for the CDNB substrate.…”

Section: Discussionmentioning

confidence: 99%

Comparison of Activities Dependent on Glutathione S-Transferase and Cytochrome P-450 IA1 in Cultured Keratinocytes and Reconstructed Epidermal Models

Harris

Siefken

Beck-Oldach

et al. 2002

Skin Pharmacol Physiol

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There is an increasing need for in vitro testing of compounds for topical application. Reconstructed epidermal models may provide a suitable and relevant model for screening compounds that may affect the activities of phase I and II enzymes involved in epidermal detoxification. In this study, we measured the activity of a phase I enzyme, cytochrome P450 IA1, i.e. 7-ethoxyresorufin-O-deethylase (EROD) and 7-ethoxycoumarin-O-deethylase (ECOD) activities, and that of a phase II enzyme, glutathione S-transferase (GST). The enzyme activities were determined in cultured keratinocytes, reconstructed epidermal models and samples of human epidermis or hair follicle. EROD activity was detected in cultured keratinocytes and was induced by 3-methylcholanthrene (3-MC) and β-naphthoflavone. The level of induction increased with increasing confluence. Induced EROD activity could be inhibited by clotrimazole in a dose-dependent manner. However, EROD activity was not detected in either hair follicles or untreated epidermal models but could be induced by 3-MC. The ability to induce EROD activity in epidermal models was batch dependent, and clotrimazole was able to inhibit the induced EROD activity. ECOD activity was detected in untreated models and paralleled EROD activity. GST activity was detected in cultured keratinocytes and all epidermal models. GST activity in models was equal or higher than the activity in epidermal samples. Reconstructed skin models may be useful to study the effects of non-water-soluble topical formulations on xenobiotic metabolism.

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“…GSTM1 may be important in the repair of DNA since it is present in the normal melanocytes in both cytoplasm and nuclei, and because it may efficiently detoxify peroxides arising in DNA (Ketterer and Meyer, 1989). Various authors have reported that GSTM 1 is almost non-existent in human epidermis (Blacker et al, 1991;Campbell et al, 1991;Raza et al, 1991;Singhal et al, 1993). Minimal amounts of the Mu class GSTs are present in human skin samples, as shown by Western blot analysis or immunohistological staining in the human epidermis, where most cells are keratinocytes.…”

Section: Discussionmentioning

confidence: 99%

Phenotype of glutathione S-transferase Mu (GSTM1) and susceptibility to malignant melanoma

Lafuente

Molina²,

Palou³

et al. 1995

Br J Cancer

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Summary The isoenzyme Mu of glutathione S-transferase (GSTM 1) is dominantly inherited, and the prevalence of this isoenzyme in the population is about 60%. The (Longstreth et al., 1992). As a host genetic factor, dysplastic naevi (DN), which are relatively distinct melanocytic lesions, can be precursors of melanoma, and responsible for the tendency of melanoma to run in families. Metabolic factors such as the isoenzyme Mu of glutathione S-transferase (GSTM1) should also be considered. GSTM1 has polymorphic expression, and about half the population from various racial groups lack it (Hussey et al., 1986). The enzyme detoxifies various carcinogenic electrophiles including epoxides, and it has therefore been attributed a protective role against neoplasias associated with smoking. Indeed, a major susceptibility to lung (Seidegard et al., 1986), bladder and larynx cancer (Lafuente et al., 1993) has been shown among smokers lacking GSTM1.When ROS damage DNA, the derived residues, which are cytotoxic and cytostatic, are also substrates of GSTM1, suggesting that these isoforms also have a role in the DNA repair system (Ketterer and Meyer, 1989).We therefore designed a study to determine whether GSTM 1 deficiency may confer susceptibility to malignant melanoma (MM) on the basis of the antioxidant properties of this isoenzyme against UV-derived ROS. Materials and methodsA total of 197 white melanoma patients were recruited at the Dermatology Department at the Hospital Clinic of Barcelona in 1993. Ninety-three patients were men (mean age 53.0 ± 19.0) and 104 were women (mean age 51.06 ± 16.4).

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Characterization of Glutathione S-Transferase in Cultured Human Keratinocytes

Cited by 31 publications

References 27 publications

Photodynamic Effects of Novel XF Porphyrin Derivatives on Prokaryotic and Eukaryotic Cells

Photodynamic Effects of Novel XF Porphyrin Derivatives on Prokaryotic and Eukaryotic Cells

Comparison of Activities Dependent on Glutathione S-Transferase and Cytochrome P-450 IA1 in Cultured Keratinocytes and Reconstructed Epidermal Models

Phenotype of glutathione S-transferase Mu (GSTM1) and susceptibility to malignant melanoma

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