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Blue light-induced oxidative stress in live skin
Abstract and Figures
Skin damage from exposure to sunlight induces aging-like changes in appearance and is attributed to the ultraviolet (UV) component of light. Photosensitized production of reactive oxygen species (ROS) by UVA light is widely accepted to contribute to skin damage and carcinogenesis, but visible light is thought not to do so. Using mice expressing redox-sensitive GFP to detect ROS, blue light could produce oxidative stress in live skin. Blue light induced oxidative stress preferentially in mitochondria, but green, red, far red or infrared light did not. Blue light-induced oxidative stress was also detected in cultured human keratinocytes, but the per photon efficacy was only 25% of UVA in human keratinocyte mitochondria, compared to 68% of UVA in mouse skin. Skin autofluorescence was reduced by blue light, suggesting flavins are the photosensitizer. Exposing human skin to the blue light contained in sunlight depressed flavin autofluorescence, demonstrating that the visible component of sunlight has a physiologically significant effect on human skin. The ROS produced by blue light is probably superoxide, but not singlet oxygen. These results suggest that blue light contributes to skin aging similar to UVA.
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... Mitochondrial oxidative stress is a type of oxidative stress induced by blue light irradiation. [27][28][29] Blue light also promotes ROS uptake into mitochondria. 30) Mitochondria trigger the activation of caspase-3, a cell death-inducing factor. ...
Diabetes mellitus includes type 1 and type 2 diabetes. Type 1 diabetes is an autoimmune disease affecting young people. Although several factors that worsen type 1 diabetes are known, information on the effects of blue light remains obscure. In this study, we investigated the effects of blue light irradiation on diabetes using mice with streptozotocin (STZ)-induced type 1 diabetes. Furthermore, we investigated the potential of selected compounds in rescuing the blue light-induced aggravation of diabetes. Blue light irradiation exacerbated type 1 diabetes. It activated insulin-like growth factor-1 and reactive oxygen species/caspase 3/apoptosis/endothelial-monocyte activating polypeptide II/neutrophil/neutrophil extracellular trap-associated cell death (NETosis) system signaling and increased the expression of angiopoietin-like protein 2 (Agptl2). These results indicate that blue light worsens type 1 diabetes by increasing NETosis production and the expression of Agptl2. Administration of pantethine or tranexamic acid prevented the blue light-induced worsening of type 1 diabetes by suppressing neutrophil production and Agptl2 expression. Our results provide insights into the effects of blue light on type 1 diabetes and highlight the potential of compounds that can be used in ameliorating such effects.
... 32 SIRT1 controls mitochondrial biogenesis through activation of PGC-1α and autophagy. 33,34 Yogic practices can regulate mitochondrial structure and functions through: Activation of PGC-1α, mitochondrial biogenesis and its content in skeletal muscle, and by improving mitochondrial transcription factors. 8,35 ...
Aging is the continuous loss of homeostasis in a cell, tissue, organ, and whole body. Over time, skin, the biggest organ in the body, may age and become more susceptible to injury. In this study, we thoroughly examined signs of ageing skin. A challenge in front is the fast aging of the people with this finding a lifestyle intervention or strategy to improve skin as well overall health with negligible harmful effects. Yoga is an inclusive program that includes dietary, lifestyle, behavioral, and psychological involvements to re-establish the system's homeostasis and works simultaneously at the body, mind, and spirit levels. Yoga is an auspicious lifestyle intervention that has exposed antiaging effects to extend healthspan by reducing the nine hallmarks of skin aging and related disorder and diseases.
To evaluate the impact of yogic practices on hallmarks of skin aging leading to improved healthspan and lifespan.
This article evaluates that Yoga is a promising tool in controlling nine hallmarks of biological skin aging which increases both health span as well as lifespan. There is a need to verify its application and find a modest, appropriate, and costless substitute to improve longevity and health span.
... Blue light has been extensively analysed in other articles, with a special focus on its ability to induce oxidative stress in live skin, because it is a high-energy visible light that can penetrate the skin deeper than both UVA and UVB lights. Several studies have revealed that longer exposure to this light can increase the amount of DNA damage, cell and tissue death, injury, eye damage, skin barrier damage, and photoaging [28,29]. As a consequence, blue light was not used in this study to analyse UPE changes. ...
... UV radiation induces damage to connective tissue through reactive oxygen species (ROS). 2 Visible light, especially blue light, also contributes to photoaging by generating ROS. 3 Although most sunscreens defend against UVB and short UVA radiation, few FDA-approved sunscreens provide coverage against long UVA radiation, and none against visible light. 4 Limited data exist on sunscreen efficacy in preventing photoaging. ...
Mitochondria play an important role in cellular function, not only as a major site of adenosine triphosphate (ATP) production but also by regulating energy expenditure, apoptosis signaling, control of the cell cycle, cellular growth, cell differentiation, transportation of metabolites, and production of reactive oxygen species. Interaction with electromagnetic waves can lead to dysregulation or alterations in the patterns of energy activities in the mitochondria. Ultraviolet light (UV) can be found in sunlight and artificial sources, such as lamps. UV radiation can cause damage to DNA, proteins, and lipids. Besides that, UV radiation is largely used in microorganism disinfection. To establish possible alterations in mitochondrial bioenergetics, this study proposes to investigate the UV (at two distinct intervals) effects on isolated mitochondria from mice liver to obtain direct responses and selective permeability of the internal membrane information. UVA‐371 and UVC‐255 nm lamps were used to irradiate, at different doses varying from 22.5 to 756 mJ/cm ² , isolated mitochondria samples. Mitochondrial respiration pathways were investigated by high‐resolution respirometry, and possible mitochondrial membrane damages were evaluated by mitochondrial swelling by spectrophotometer analysis. UVC irradiation results (in the higher dose) indicate decrease in 75% of mitochondrial bioenergetics capacity, such as limitation of oxidative phosphorylation in 60% and increased energy dissipation in 30%. Mitochondrial swelling experiments (spectrophotometer) indicated inner membrane damage, and consequently a loss of selective permeability. Direct correlation between irradiation and effect responses was observed, mitochondrial bioenergetics is severely affected by UVC radiation, but (UVA) radiation did not present bioenergetic alterations. These alterations can contribute to improving the knowledge behind the cell death mechanism in disinfection UV light and UV therapy such as phototherapy.
Genetically encoded probes based on the H2O2-sensing proteins OxyR and Orp1 have greatly increased the ability to detect elevated H2O2 levels in stimulated or stressed cells. However, these proteins are not sensitive enough to monitor metabolic H2O2 baseline levels. Using yeast as a platform for probe development, we developed two peroxiredoxin-based H2O2 probes, roGFP2-Tsa2ΔCR and roGFP2-Tsa2ΔCPΔCR, that afford such sensitivity. These probes are ∼50% oxidized under 'normal' unstressed conditions and are equally responsive to increases and decreases in H2O2. Hence, they permit fully dynamic, real-time measurement of basal H2O2 levels, with subcellular resolution, in living cells. We demonstrate that expression of these probes does not alter endogenous H2O2 homeostasis. The roGFP2-Tsa2ΔCR probe revealed real-time interplay between basal H2O2 levels and partial oxygen pressure. Furthermore, it exposed asymmetry in H2O2 trafficking between the cytosol and mitochondrial matrix and a strong correlation between matrix H2O2 levels and cellular growth rate.
Background:
Observational and experimental data suggest that antioxidant and/or zinc supplements may delay progression of age-related macular degeneration (AMD) and vision loss.
Objective:
To evaluate the effect of high-dose vitamins C and E, beta carotene, and zinc supplements on AMD progression and visual acuity.
Design:
The Age-Related Eye Disease Study, an 11-center double-masked clinical trial, enrolled participants in an AMD trial if they had extensive small drusen, intermediate drusen, large drusen, noncentral geographic atrophy, or pigment abnormalities in 1 or both eyes, or advanced AMD or vision loss due to AMD in 1 eye. At least 1 eye had best-corrected visual acuity of 20/32 or better. Participants were randomly assigned to receive daily oral tablets containing: (1) antioxidants (vitamin C, 500 mg; vitamin E, 400 IU; and beta carotene, 15 mg); (2) zinc, 80 mg, as zinc oxide and copper, 2 mg, as cupric oxide; (3) antioxidants plus zinc; or (4) placebo.
Main outcome measures:
(1) Photographic assessment of progression to or treatment for advanced AMD and (2) at least moderate visual acuity loss from baseline (> or =15 letters). Primary analyses used repeated-measures logistic regression with a significance level of.01, unadjusted for covariates. Serum level measurements, medical histories, and mortality rates were used for safety monitoring.
Results:
Average follow-up of the 3640 enrolled study participants, aged 55-80 years, was 6.3 years, with 2.4% lost to follow-up. Comparison with placebo demonstrated a statistically significant odds reduction for the development of advanced AMD with antioxidants plus zinc (odds ratio [OR], 0.72; 99% confidence interval [CI], 0.52-0.98). The ORs for zinc alone and antioxidants alone are 0.75 (99% CI, 0.55-1.03) and 0.80 (99% CI, 0.59-1.09), respectively. Participants with extensive small drusen, nonextensive intermediate size drusen, or pigment abnormalities had only a 1.3% 5-year probability of progression to advanced AMD. Odds reduction estimates increased when these 1063 participants were excluded (antioxidants plus zinc: OR, 0.66; 99% CI, 0.47-0.91; zinc: OR, 0.71; 99% CI, 0.52-0.99; antioxidants: OR, 0.76; 99% CI, 0.55-1.05). Both zinc and antioxidants plus zinc significantly reduced the odds of developing advanced AMD in this higher-risk group. The only statistically significant reduction in rates of at least moderate visual acuity loss occurred in persons assigned to receive antioxidants plus zinc (OR, 0.73; 99% CI, 0.54-0.99). No statistically significant serious adverse effect was associated with any of the formulations.
Conclusions:
Persons older than 55 years should have dilated eye examinations to determine their risk of developing advanced AMD. Those with extensive intermediate size drusen, at least 1 large druse, noncentral geographic atrophy in 1 or both eyes, or advanced AMD or vision loss due to AMD in 1 eye, and without contraindications such as smoking, should consider taking a supplement of antioxidants plus zinc such as that used in this study.
Fluorescent protein sensors have re-vitalized the field of redox biology by revolutionizing the study of redox processes in living cells and organisms. Recent Advances: Within one decade a set of fundamental new insights has been gained, driven by the rapid technical development of in vivo redox sensing. Redox-sensitive yellow and green fluorescent protein variants (rxYFP and roGFPs) have been the central players.
Although widely used as an established standard tool, important questions remain surrounding their meaningful use in vivo. We review the growing range of thiol redox sensor variants and their application in different cells, tissues and organisms. We highlight five key findings where in vivo sensing has been instrumental in changing our understanding of redox biology, critically assess the interpretation of in vivo redox data and discuss technical and biological limitations of current redox sensors and sensing approaches.
We explore how novel sensor variants may further add to the current momentum towards a novel mechanistic and integrated understanding of redox biology in vivo.
Mutations in sunlight-induced melanoma arise from cyclobutane pyrimidine dimers (CPDs), DNA photoproducts that are typically created picoseconds after an ultraviolet (UV) photon is absorbed at thymine or cytosine. We found that in melanocytes, CPDs are generated for >3 hours after exposure to UVA, a major component of the radiation in sunlight and in tanning beds. These "dark CPDs" constitute the majority of CPDs and include the cytosine-containing CPDs that initiate UV-signature C→T mutations. Dark CPDs arise when UV-induced reactive oxygen and nitrogen species combine to excite an electron in fragments of the pigment melanin. This creates a quantum triplet state that has the energy of a UV photon but induces CPDs by energy transfer to DNA in a radiation-independent manner. Melanin may thus be carcinogenic as well as protective against cancer. These findings also validate the long-standing suggestion that chemically generated excited electronic states are relevant to mammalian biology.
Copyright © 2015, American Association for the Advancement of Science.
Most of us know there is a payoff to looking good, and in the quest for beauty we spend countless hours and billions of dollars on personal grooming, cosmetics, and plastic surgery. But how much better off are the better looking? Based on the evidence, quite a lot. The first book to seriously measure the advantages of beauty,Beauty Paysdemonstrates how society favors the beautiful and how better-looking people experience startling but undeniable benefits in all aspects of life. Noted economist Daniel Hamermesh shows that the attractive are more likely to be employed, work more productively and profitably, receive more substantial pay, obtain loan approvals, negotiate loans with better terms, and have more handsome and highly educated spouses. Hamermesh explains why this happens and what it means for the beautiful--and the not-so-beautiful--among us. Exploring whether a universal beauty standard exists, Hamermesh illustrates how attractive workers make more money, how these amounts differ by gender, and how looks are valued differently based on profession. The author wonders whether extra pay for good-looking people represents discrimination, and, if so, who is discriminating. He investigates the commodification of beauty in dating and how this influences the search for intelligent or high-earning mates, and even considers whether government programs should aid the ugly. Hamermesh also discusses whether the economic benefits of beauty will persist into the foreseeable future and what the "looks-challenged" can do to overcome their disadvantage. © Daniel S. Hamermesh Princeton University Press. All Rights Reserved.
The photochemical aspects of flavins have been reviewed with reference to the analysis of flavins and photoproducts in degraded solutions, spectral and photophysical properties, photodegradation reactions, photosensitization reactions, and photostability of riboflavin in pharmaceutical preparations. The photochemistry of flavins in aqueous solution involves two major photodegradation reactions, viz intramolecular photoreduction and photoaddition, occurring separately or concomitantly in the presence of phosphate buffer, leading to the formation of lumichrome and cyclodehydroriboflavin, respectively. The photoreduction is catalyzed by H2PO4- ions and the photoaddition by HPO42− ions. Intermolecular photoreduction also takes place in a large number of flavin-substrate interactions involving the flavin triplet state. Knowledge of the spectral and photophysical properties, and photochemical behaviour of flavins is necessary to understand the nature of flavin–protein interactions, flavin photosensitization reactions, and their role in biological processes. The study of the photochemical behaviour of riboflavin as a function of pH is a prerequisite to achieve optimum stability of the vitamin in pharmaceutical preparations. Technological processes are being developed to utilize riboflavin as a photosensitizer in the pathogenic inactivation of blood components. Riboflavin-sensitized photooxidation of amino acids in protein may have important biological implications to control photoinduced damage in biological systems. The application of femtosecond-resolved fluorescence spectroscopy and transient absorption techniques may provide useful information on the dynamics of flavoproteins.
Integrity of human skin is endangered by exposure to UV irradiation and chemical stressors, which can provoke a toxic production of reactive oxygen species (ROS) and oxidative damage. Since oxidation of proteins and metabolites occurs virtually instantaneously, immediate cellular countermeasures are pivotal to mitigate the negative implications of acute oxidative stress. We investigated the short-term metabolic response in human skin fibroblasts and keratinocytes to H2O2 and UV exposure. In time-resolved metabolomics experiments, we observed that within seconds after stress induction, glucose catabolism is routed to the oxidative pentose phosphate pathway (PPP) and nucleotide synthesis independent of previously postulated blocks in glycolysis (i.e., of GAPDH or PKM2). Through ultra-short (13)C labeling experiments, we provide evidence for multiple cycling of carbon backbones in the oxidative PPP, potentially maximizing NADPH reduction. The identified metabolic rerouting in oxidative and non-oxidative PPP has important physiological roles in stabilization of the redox balance and ROS clearance.
Copyright © 2015 Elsevier Inc. All rights reserved.
DNA damage induced by UV radiation and visible light (290-500 nm) in AS52 Chinese hamster cells was analysed by an alkaline elution assay with specific repair endonucleases. Cells were exposed to extensively filtered monochrome or broad-band radiation. Between 290 and 315 nm, the ratio of base modifications sensitive to Fpg protein (i.e. 8-hydroxyguanine and formamidopyrimidines) and T4 endonuclease V (i.e. cyclobutane pyrimidine dimers) was constant (approximately 1:200), indicating that the direct excitation of DNA is responsible for both types of damage in this range of the spectrum. While the yield of pyrimidine dimers per unit dose continued to decrease exponentially beyond 315 nm, the yield of Fpg-sensitive modifications increased to a second maximum between 400 and 450 nm. The damage spectrum in this wavelength range consisted of only a few other modifications (strand breaks, abasic sites and pyrimidine modifications sensitive to endonuclease III) and is attributed to endogenous photosensitizers that give rise to oxidative DNA damage via singlet oxygen and/or type I reactions. The generation of Fpg-sensitive modifications by visible light was not linear with dose but followed a saturation curve. It is calculated that the exposure of the cells to low doses of solar radiation results in the formation of cyclobutane pyrimidine dimers and Fpg-sensitive modifications in a ratio of 10:1.
Description
Flavins and flavoproteins are a widely investigated and highly versatile group of compounds. Participation of these compounds in photochemistry and photobiology processes are of particular importance in the fields of biology, chemistry and medicine. Written by leading experts in the field each section of the book includes a historical overview of the subject, state of the art developments and future perspectives. Flavins: Photochemistry and Photobiology begins with the properties and applications of flavins, including their photochemistry in aqueous and organic solutions. Subsequent sections discuss riboflavin as a visible light sensitizer in the photo degradation of drugs, antiviral and antibacterial effects, the role of flavins in light induced toxicity and blue light initiated DNA repair by photolyase. Finally there are sections on the flavin based photoreceptors in plants, bacteria and eukaryotic photosynthetic flagelettes. This book brings together leading experts with a unique interdisciplinary emphasis, to provide an authoritative resource on flavins and their role in photochemistry and photobiology.