Glutathione S-transferase polymorphisms in patients with photosensitive and non-photosensitive drug eruptions

Tissue expression of glutathione S transferase isoenzymes in vitiligo

The association of glutathione S-transferase (GST) enzymes with vitiligo is inconclusive. To evaluate tissue expressions of GST isoenzymes in vitiligo patients and to compare these expressions with healthy controls, we used 26 active depigmented patches on the trunk of vitiligo patients and 20 healthy sex and age matched controls. Punch biopsies were taken from the lesioned or normal skin. Tissue expression of GST isoenzymes were analyzed immunohistochemically. Tissue expression of GSTT1, GSTA1 and GSTP1 was significantly higher in the patient group than controls. Tissue expression of GSTM1 was not significantly different between the two groups. The increased tissue expression of GSTT1, GSTA1 and GSTP1 may represent a response to excess free radical formation in vitiligo and may support the role of oxidative stress in the pathogenesis of vitiligo.

Variability of the Genes Involved in the Cellular Redox Status and Their Implication in Drug Hypersensitivity Reactions

Adverse drug reactions are a major cause of morbidity and mortality. Of the great diversity of drugs involved in hypersensitivity drug reactions, the most frequent are non-steroidal anti-inflammatory drugs followed by β-lactam antibiotics. The redox status regulates the level of reactive oxygen and nitrogen species (RONS). RONS interplay and modulate the action of diverse biomolecules, such as inflammatory mediators and drugs. In this review, we address the role of the redox status in the initiation, as well as in the resolution of inflammatory processes involved in drug hypersensitivity reactions. We summarize the association findings between drug hypersensitivity reactions and variants in the genes that encode the enzymes related to the redox system such as enzymes related to glutathione: Glutathione S-transferase (GSTM1, GSTP, GSTT1) and glutathione peroxidase (GPX1), thioredoxin reductase (TXNRD1 and TXNRD2), superoxide dismutase (SOD1, SOD2, and SOD3), catalase (CAT), aldo-keto reductase (AKR), and the peroxiredoxin system (PRDX1, PRDX2, PRDX3, PRDX4, PRDX5, PRDX6). Based on current evidence, the most relevant candidate redox genes related to hypersensitivity drug reactions are GSTM1, TXNRD1, SOD1, and SOD2. Increasing the understanding of pharmacogenetics in drug hypersensitivity reactions will contribute to the development of early diagnostic or prognosis tools, and will help to diminish the occurrence and/or the severity of these reactions.

Comparison of the tissue expressions of glutathione S transferase isoenzymes among patients with morphea and healthy controls: A preliminary study

Morphea is an inflammatory connective tissue disorder, which is characterized by sclerosis in skin and subcutaneous tissues with a chronic progress. The oxidative stress in pathogenesis of sclerosing diseases was proposed in several studies with conflicting results. To explore the tissue expressions of Glutathione S transferase (GST) isoenzymes in patients with morphea and compare these expressions with healthy controls. Twenty-two morphea patients and 20 sex and age matched healthy controls were enrolled in this study. Four millimeter punch biopsies were performed from the active sclerotic plaques of morphea patients. Tissue samples of control group were obtained from nonlesional normal skin biopsy specimens. The protein expressions of GST isoenzymes were analyzed immunohistochemically. Tissue expressions of GSTP1, GSTT1, and GSTA1 isoenzymes in morphea patients were found to be significantly higher than in control tissues. There was no significant difference in GSTM1 isoenzyme expression between the two groups. The increased tissue expressions of GSTA1, GSTP1, and GSTT1 isoenzymes in morphea may represent the activated GST enzymes in response to excessive free radical formation and may also support the hypothesis of increased oxidative stress in morphea etiopathogenesis.

GSTP1 and cancer: Expression, methylation, polymorphisms and signaling (Review)

Glutathione S‑transferase Pi (GSTP1) is an isozyme encoded by the GST pi gene that plays an important regulatory role in detoxification, anti‑oxidative damage, and the occurrence of various diseases. The aim of the present study was to review the association between the expression of GSTP1 and the development and treatment of various cancers, and discuss GSTP1 methylation in several malignant tumors, such as prostate, breast and lung cancer, as well as hepatocellular carcinoma; to review the association between polymorphism of the GSTP1 gene and various diseases; and to review the effects of GSTP1 on electrophilic oxidative stress, cell signal transduction, and the regulation of carcinogenic factors. Collectively, GSTP1 plays a major role in the development of various diseases.