Kostyuk V.A.,Laboratory of Tissue Engineering and Cutaneous Pathophysiology |
Kostyuk V.A.,Belarusian State University |
Potapovich A.I.,Laboratory of Tissue Engineering and Cutaneous Pathophysiology |
Potapovich A.I.,Belarusian State University |
And 12 more authors.
Antioxidants and Redox Signaling | Year: 2010
Oxidative stress due to increased epidermal levels of H2O 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 H2O2 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 H2O 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-H2O2-based mechanism of dysregulation of cytokine-mediated keratinocyte-melanocyte interaction in vitiligo. © 2010 Mary Ann Liebert, Inc.
de Luca C.,Laboratory of Tissue Engineering and Cutaneous Pathophysiology |
Scordo G.,Uppsala University Hospital |
Cesareo E.,Laboratory of Tissue Engineering and Cutaneous Pathophysiology |
Raskovic D.,Laboratory of Tissue Engineering and Cutaneous Pathophysiology |
And 2 more authors.
Indian Journal of Experimental Biology | Year: 2010
Inherited or acquired impairment of xenobiotics metabolism is a postulated mechanism underlying environment-associated pathologies such as multiple chemical sensitivity, fibromyalgia, chronic fatigue syndrome, dental amalgam disease, and others, also collectively named idiopathic environmental intolerances (IEI). In view of the poor current knowledge of their etiology and pathogenesis, and the absence of recognised genetic and metabolic markers of the diseases. They are often considered medically unexplained syndromes,. These disabling conditions share the features of poly-symptomatic multi-organ syndromes, considered by part of the medical community to be aberrant responses triggered by exposure to low-dose organic and inorganic chemicals and metals, in concentrations far below average reference levels admitted for environmental toxicants. A genetic predisposition to altered biotransformation of environmental chemicals, drugs, and metals, and of endogenous low-molecular weight metabolites, caused by polymorphisms of genes coding for xenobiotic metabolizing enzymes, their receptors and transcription factors appears to be involved in the susceptibility to these environment-associated pathologies, along with epigenetic factors. Free radical/antioxidant homeostasis may also be heavily implicated, indirectly by affecting the regulation of xenobiotic metabolizing enzymes, and directly by causing increased levels of oxidative products, implicated in the chronic damage of cells and tissues, which is in part correlated with clinical symptoms. More systematic studies of molecular epidemiology, toxico- and pharmaco-genomics, elucidating the mechanisms of regulation, expression, induction, and activity of antioxidant/detoxifying enzymes, and the possible role of inflammatory mediators, promise a better understanding of this pathologically increased sensitivity to low-level chemical stimuli, and a solid basis for effective individualized antioxidant- and/or chelator-based treatments.