Dysfunction of glutathione S-transferase leads to excess 4-hydroxy-2-nonenal and H(2)O(2) and impaired cytokine pattern in cultured keratinocytes and blood of vitiligo patients

Antioxid Redox Signal. 2010 Sep 1;13(5):607-20. doi: 10.1089/ars.2009.2976.

Abstract

Oxidative stress due to increased epidermal levels of H(2)O(2) with consequent inhibition of catalase activity is generally accepted as a leading cytotoxic mechanism of melanocyte loss in vitiligo. Keratinocyte-derived cytokines are considered key factors in the maintenance of melanocyte structure and functions. We hypothesized that abnormal redox control may lead to impaired cytokine production by keratinocytes, thus causing noncytotoxic defects in melanocyte proliferation and melanogenesis. We found significantly suppressed mRNA and protein expression of glutathione-S-transferase (GST) M1 isoform, and higher-than-normal levels of both 4-hydroxy-2-nonenal (HNE)-protein adducts and H(2)O(2) in the cultures of keratinocytes derived from unaffected and affected skin of vitiligo patients, and in their co-cultures with allogeneic melanocytes. GST and catalase activities, as well as glutathione levels, were dramatically low in erythrocytes, whilst HNE-protein adducts were high in the plasma of vitiligo patients. The broad spectrum of major cytokines, chemokines, and growth factors was dysregulated in both blood plasma and cultured keratinocytes of vitiligo patients, when compared to normal subjects. Exogenous HNE added to normal keratinocytes induced a vitiligo-like cytokine pattern, and H(2)O(2) overproduction accompanied by adaptive upregulation of catalase and GSTM1 genes, and transient inhibition of Erk1/2 and Akt phosphorylation. Based on these results, we suggest a novel GST-HNE-H(2)O(2)-based mechanism of dysregulation of cytokine-mediated keratinocyte-melanocyte interaction in vitiligo.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Aldehydes / blood
  • Aldehydes / metabolism*
  • Aldehydes / pharmacology
  • Catalase / genetics
  • Catalase / metabolism
  • Child
  • Coculture Techniques
  • Cytokines / genetics
  • Cytokines / metabolism*
  • Erythrocytes / metabolism
  • Extracellular Signal-Regulated MAP Kinases / metabolism
  • Female
  • Fibroblast Growth Factor 2 / genetics
  • Gene Expression / genetics
  • Gene Expression / radiation effects
  • Glutathione / metabolism
  • Glutathione Disulfide / metabolism
  • Glutathione Transferase / genetics
  • Glutathione Transferase / metabolism*
  • Humans
  • Hydrogen Peroxide / metabolism*
  • Interleukin-6 / genetics
  • Interleukin-6 / metabolism
  • Keratinocytes / cytology
  • Keratinocytes / drug effects
  • Keratinocytes / metabolism*
  • Keratinocytes / radiation effects
  • Male
  • Melanocytes / cytology
  • Middle Aged
  • Nitric Oxide Synthase Type II / genetics
  • Oxidation-Reduction
  • Phosphorylation / radiation effects
  • Proto-Oncogene Proteins c-akt / metabolism
  • SOXB1 Transcription Factors / genetics
  • Superoxide Dismutase / metabolism
  • Tumor Necrosis Factor-alpha / blood
  • Tumor Necrosis Factor-alpha / genetics
  • Tumor Suppressor Protein p53 / metabolism
  • Ultraviolet Rays
  • Vitiligo / blood*
  • Vitiligo / metabolism*
  • Young Adult

Substances

  • Aldehydes
  • Cytokines
  • Interleukin-6
  • SOXB1 Transcription Factors
  • Tumor Necrosis Factor-alpha
  • Tumor Suppressor Protein p53
  • Fibroblast Growth Factor 2
  • Hydrogen Peroxide
  • Catalase
  • NOS2 protein, human
  • Nitric Oxide Synthase Type II
  • Superoxide Dismutase
  • glutathione S-transferase T1
  • GSTA1 protein, human
  • Glutathione Transferase
  • glutathione S-transferase M1
  • AKT1 protein, human
  • Proto-Oncogene Proteins c-akt
  • Extracellular Signal-Regulated MAP Kinases
  • Glutathione
  • 4-hydroxy-2-nonenal
  • Glutathione Disulfide