Oxidatively Generated Damage to Cellular DNA by UVB and UVA Radiation^,

Abstract

This review article focuses on a critical survey of the main available information on the UVB and UVA oxidative reactions to cellular DNA as the result of direct interactions of UV photons, photosensitized pathways and biochemical responses including inflammation and bystander effects. UVA radiation appears to be much more efficient than UVB in inducing oxidatively generated damage to the bases and 2-deoxyribose moieties of DNA in isolated cells and skin. The UVA-induced generation of 8-oxo-7,8-dihydroguanine is mostly rationalized in terms of selective guanine oxidation by singlet oxygen generated through type II photosensitization mechanism. In addition, hydroxyl radical whose formation may be accounted for by metal-catalyzed Haber-Weiss reactions subsequent to the initial generation of superoxide anion radical contributes in a minor way to the DNA degradation. This leads to the formation of both oxidized purine and pyrimidine bases together with DNA single-strand breaks at the exclusion, however, of direct double-strand breaks. No evidence has been provided so far for the implication of delayed oxidative degradation pathways of cellular DNA. In that respect putative characteristic UVA-induced DNA damage could include single and more complex lesions arising from one-electron oxidation of the guanine base together with aldehyde adducts to amino-substituted nucleobases.

Restoration of Mitochondrial Integrity, Telomere Length, and Sensitivity to Oxidation by In Vitro Culture of Fuchs' Endothelial Corneal Dystrophy Cells

“…9,10,46,47 UVA wavelengths were used in this experiment because they represent 75% of the terrestrial UV radiations, they are known to reach the corneal endothelium, and they efficiently induce ROS. [6][7][8]48 H 2 O 2 , an oxidizing component induced by the mitochondrial respiratory chain, was also used to assess sensitivity to oxidative stress. Both UVA-and H 2 O 2 -induced cell death methods showed that FECD and healthy cultured cells behave similarly in the presence of oxidative stress (Fig.…”

“…8 Together, the high aerobic metabolism, the lifetime exposure to toxic sunlight, and the fact that the corneal endothelial cells in vivo are arrested in the G 1 phase of the cycle (i.e., nonmitotic cells) make the corneal endothelium prone to oxidative stress. recently described in FECD corneal endothelial cells, mostly at the level of mitochondrial DNA (mtDNA).…”

Radical-Scavenging Activity of a Sunscreen Enriched by Antioxidants Providing Protection in the Whole Solar Spectral Range

“…The effects caused by exposure to ultraviolet (UV; 280-400 nm) radiation are well documented in the literature [1,2]; however, the effects of visible (VIS; 400-760 nm) and near-infrared (NIR; 760-3,000 nm) radiations have not yet been fully elucidated, and recent studies have evaluated their effects on the skin [3,4,5]. It is well known that moderate sun exposure is essential for the vitamin D synthesis that is fundamental for the bone and muscle status [6].…”

Drivers of amphibian declines: effects of ultraviolet radiation and interactions with other environmental factors

“…8). Oxidation of DNA by ROS gives rise to several types of lesions, the most common of which is 8-oxo-7,8-dihydroguanine (8-oxoGua) [22]. Crosslinks between DNA and proteins also arise from the generation of aldehydes from the oxidation of lipids [23].…”