Differential Expression of Nitric Oxide Synthase Isoforms nNOS and iNOS in Patients with Non-Segmental Generalized Vitiligo
نویسندگان
چکیده
Nitric oxide (NO) is involved in several biological processes, but its role in human melanogenesis is still not well understood. Exposure to UVA and UVB induces nitric oxide production in keratinocytes and melanocytes through the activation of constitutive nitric oxide synthase, increasing tyrosinase activity and melanin synthesis, whereas inducible nitric oxide synthase over expression might be involved in hypopigmentary disorders. The aim of this study was to evaluate whether inducible nitric oxide synthase and neuronal nitric oxide synthase expression were modified in vitiligo skin compared to healthy controls. Skin biopsies were obtained from inflammatory/lesional and white/lesional skin in 12 patients with active, non-segmental vitiligo; site-matched biopsies of normal skin from eight patients were used as controls. Nitric oxide synthase isoforms expression was evaluated by confocal laser scanning microscopy and Western Blot analysis. Inducible nitric oxide synthase expression was significantly increased in inflammatory/lesional skin compared to healthy skin; melanocytes showed a moderate neuronal nitric oxide synthase expression in white/lesional skin, demonstrating that metabolic function still goes on. The obtained data demonstrated that vitiligo lesions were characterized by modifications of nitric oxide synthase isoforms, thus confirming the hypothesis that nitric oxide imbalance is involved in vitiligo and supporting the idea that nitric oxide synthase inhibitors might be used as a possible therapeutic approach for the management of vitiligo.
منابع مشابه
EXPRESSION OF INDUCIBLE NITRIC OXIDE SYNTHASE GENE (iNOS) STIMULATED BY HYDROGEN PEROXIDE IN HUMAN ENDOTHELIAL CELLS
Inducible nitric oxide synthase (iNOS) gene expresses a calcium calmudolin-independent enzyme which can catalyse NO production from L-arginine. The induction of iNOS activity has been demonstrated in a wide variety of cell types under stimulation with cytokines and lipopoly saccharide (LPS). Previous studies indicated that all nitric oxide synthases (NOS) activated in human umbilical vein endot...
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متن کاملNitric oxide and the bioactivities
Nitric oxide (NO), previously known as Endothelium-Derived Relaxing Factor (EDRF) is involved in a wide range of physiological and pathophysiological mechanisms. It is synthesized endogenously by the enzymes Nitric Oxide Synthase (NOS) in specialized tissues from its precursor L-arginine, yielding L-citrulline as a byproduct. It is released by a family of isoenzymes, viz., the endothelial (eNOS...
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