Nitric oxide is responsible for oxidative skin injury and modulation of cell proliferation after 24 hours of UVB exposures

Abstract

Nitric oxide (NO) is produced by various mammalian cells and plays a variety of regulatory roles in normal physiology and in pathological processes. This article provides evidence regarding the participation of NO in UVB-induced skin lesions and in the modulation of skin cell proliferation following UVB skin irradiation. Hairless mice were subjected to UVB irradiation for 3 hours and the skin evaluated immediately, 6 and 24 hours postirradiation. The skin lipid peroxidation, and NO levels evaluated by chemiluminescence and inducible nitric oxide synthase (iNOS) and nitrotyrosine immunolabelling increased significantly 24 hours after irradiation and decreased under the treatment with aminoguanidine (AG). On the other hand, cell proliferation markers, PCNA and VEGF showed a strong labelling index when AG was used. The data indicate that NO mediates, at least in part, the lipid peroxidation and protein nitration and also promotes the down regulation of factors involved in cell proliferation. This work shows that the NO plays an important role in the oxidative stress damage and on modulation of cell proliferation pathways in UVB irradiated skin.

Keywords::

• nitric oxide
• lipid peroxidation
• oxidative stress
• UVB skin irradiation
• proliferation markers
• iNOS
• cell proliferation
• modulation

Acknowledgements

Grant support was provided by the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior – CAPES. The authors are very grateful to J. A. Vargas for his excellent technical assistance.

Declaration of interest The authors state no conflict of interest. The authors alone are responsible for the content and writing of the paper.