Tips and turns of bacteriophytochrome photoactivation
Phytochromes are red light-sensing photoreceptors. Here we review the current understanding of phytochrome photoactivation, with a special focus on bacteriophytochromes and their crystallographic studies.
Photodynamic therapy of oral lichen planus
Oral lichen planus (OLP) is a chronic inflammatory and immune-mediated disease affecting the oral mucosa.
Possibilities to estimate the personal UV radiation exposure from ambient UV radiation measurements
This paper summarizes the recent possibilities to use measurements of ambient UV radiation for estimations of the personal UV exposure of people.
The bright side of sound: perspectives on the biomedical application of sonoluminescence
Delivery light to deep tissues in vivo is a challenge. Sonoluminescence, the transduction of sound into light via the intermediate step of cavitation bubble collapse, might be a new endeavour to face this issue.
Lipids in ultraviolet radiation-induced immune modulation
Ultraviolet (UV) radiation modulates cutaneous lipids which in turn mediates immune suppression – a key mechanism conferring both detrimental and beneficial impacts of sun exposure on human health.
Fluorescence recovery protein: a powerful yet underexplored regulator of photoprotection in cyanobacteria
This review is devoted to the fluorescence recovery protein, which efficiently regulates the orange carotenoid protein-based photoprotection mechanism in cyanobacteria and has widespread homologous genes with yet unknown functions.
Composition, phosphorylation and dynamic organization of photosynthetic protein complexes in plant thylakoid membrane
Here we present an overview of the composition and organization of photosynthetic protein complexes in thylakoid membrane and discuss the consequences of the light-induced protein network re-organization to the thylakoid membrane ultrastructure.
Revisiting cyanobacterial state transitions
Critical evaluation of “new” and “old” models of cyanobacterial state transitions. Phycobilisome and membrane contributions to this mechanism are addressed. The signaling transduction pathway is discussed.
Studying the excited electronic states of guanine rich DNA quadruplexes by quantum mechanical methods: main achievements and perspectives
Calculations are providing more and more useful insights into the interaction between light and DNA quadruplexes.
Purple bacteria photo-bioelectrochemistry: enthralling challenges and opportunities
Perspective of research directions exploring purple bacteria photo-bioelectrochemistry: from harvesting photoexcited electrons to bioelectrochemical systems development.
Effects of UVR exposure on the gut microbiota of mice and humans
Changes in relative abundance of bacterial phyla in faecal samples from humans and mice exposed to UV radiation.
High aldehyde dehydrogenase activity does not protect colon cancer cells against TPCS2a-sensitized photokilling
Overexpression of Aldehyde Dehydrogenases (ALDH) has been linked to cancer therapy resistance. Here we show that high ALDH activity do not cause resistance against photodynamic therapy using the PCI-photosensitizer TPCS2a/fimaporfin.
Physiological and biochemical responses driven by different UV-visible radiation in Osmundea pinnatifida (Hudson) Stackhouse (Rhodophyta)
Different radiation qualities can modulate the production of pigments and other compounds, through photoreceptors sensitive to colored lights (red, green, and blue) and UV radiation.
Antimicrobial photodynamic therapy fighting polymicrobial infections – a journey from in vitro to in vivo
The batericidal effects of antimicrobial photodynamic therapy (aPDT), using methylene blue as a photosensitizer and pulsed red LED light for activation, were tested in various environments in vitro and in a wound model in mice infected with a fecal bacterial suspension.
Near infrared light exposure is associated with increased mitochondrial membrane potential in retinal pigmented epithelial cells
The goal of this study was to characterize the effect of near-infrared light exposure on mitochondrial membrane potential, in vitro.
The robustness of the terminal emitter site in major LHCII complexes controls xanthophyll function during photoprotection
Xanthophylls in light harvesting complexes perform a number of functions ranging from structural support to light-harvesting and photoprotection.
Photooxidation mediated by 11-cis and all-trans retinal in single isolated mouse rod photoreceptors
The fluorescence spectrum of the dye BODIPY C11 shifts upon oxidation, allowing the measurement of light-induced oxidation mediated by 11-cis and all-trans retinal in isolated single mouse rod photoreceptors with fluorescence imaging.
Restricted suitability of BODIPY for caging in biological applications based on singlet oxygen generation
Photochemical analysis and biological characterization in vitro revealed not only significant limitations of the BODIPY-caged inhibitor concept regarding uncaging in aqueous solution, but also promising cancer cell treatment through photodynamic effects.
A photoproduct of DXCF cyanobacteriochromes without reversible Cys ligation is destabilized by rotating ring twist of the chromophore
Twisted DXCF CBCRs showed dark reversion but relaxed ones did not show detectable dark reversion. The reaction was observed not for the DXCF CBCRs having reversible ligation activity, but for the DXCF CBCRs lacking reversible ligation activity.
Remodelling of fibrillin-rich microfibrils by solar-simulated radiation: impact of skin ethnicity
Cutaneous fibrillin-rich microfibrils (FRMs) should be considered as two distinct populations that differentially accrue damage in response to SSR. Furthermore, FRMs derived from black African skin show greater change following UVR challenge.
Anti- and pro-oxidative mechanisms comparing the macular carotenoids zeaxanthin and lutein with other dietary carotenoids – a singlet oxygen, free-radical in vitro and ex vivo study
The macular pigment lutein is shown to be a particularly efficient protector compared to other dietary carotenoids against a range of specific ROS at all oxygen concentrations.
Quercetin protects ARPE-19 cells against photic stress mediated by the products of rhodopsin photobleaching
Exposure to intense light could increase the risk of phototoxic reactions mediated by rhodopsin photobleaching products (RPBP) that might accumulate in photoreceptor outer segments (POS).
Photodynamic treatment of melanoma cells using aza-dipyrromethenes as photosensitizers
In this study, we report for the first time the use of four aza-dipyrromethenes (ADPMs) as photosensitizers for cancer PDT.
Food-based strategies for prevention of vitamin D deficiency as informed by vitamin D dietary guidelines, and consideration of minimal-risk UVB radiation exposure in future guidelines
There is widespread acknowledgement of the presence of vitamin D deficiency in the community and the pressing need to address this. Strategies to tackle this deficiency need to consider the role of food and UVB sun in supplying vitamin D to the body.
Multifunctional cubic liquid crystalline nanoparticles for chemo- and photodynamic synergistic cancer therapy
Multifunctional lipidic cubic liquid crystalline nanoparticles for potential cancer therapy were engineered by conjugating a porphyrin-based photosensitizer to the block copolymer Pluronic F108 and loading them with the antineoplastic drug Docetaxel.
The cyanobacterial phytochrome 2 regulates the expression of motility-related genes through the second messenger cyclic di-GMP
Blue light controls the expression of genes which are involved in behavioural responses of the cyanobacterium Synechocystis sp. PCC 6803.
Photophysics of deinoxanthin, the keto-carotenoid bound to the main S-layer unit of Deinococcus radiodurans
An ultrafast transient absorption experiment on the SDBC, which binds the carotenoid deinoxanthin, reveals a non-specific binding site that loosely binds the carotenoid, but protects the carotenoid from the outer environment.
Optogenetic Rac1 engineered from membrane lipid-binding RGS-LOV for inducible lamellipodia formation
We report the construction of a single-component optogenetic Rac1 (opto-Rac1) to control actin polymerization by dynamic membrane recruitment.
Nicotinamide for skin cancer chemoprevention: effects of nicotinamide on melanoma in vitro and in vivo
Nicotinamide is chemopreventive against keratinocyte cancers but its effects on melanoma are unknown. Clinically-achievable nicotinamide doses do not enhance melanoma viability, proliferation or invasion and enhance tumour-infiltrating lymphocytes.
Visible light in photodermatology
Until recently, visible light had been regarded to be without significant photobiologic effect on the skin. However, recent studies demonstrate that measurable effects can be documented in all skin types.
Sunscreen: FDA regulation, and environmental and health impact
Despite the concern for potential environmental and health effects, the FDA still considers organic UVR filters safe for use. For those who are concerned, inorganic UVR filter (namely, zinc oxide and titanium dioxide)-based sunscreens can be used.
About this collection
The World Congress on Light and Life (17th Congress of the International Union of Photobiology and 18th Congress of the European Society for Photobiology) was held in Barcelona in August-September 2019 (https://www.photobiology.eu/2019-esp-congress). All scientists presenting data were invited to contribute original papers or perspectives within the themes of the Congress for this virtual collection. Editing was carried out by the relevant associate editors as well as invited guest editors who contributed to various themes. The collection also includes a separate issue on ‘Photofunctional flavoproteins and UVB photosensors’ edited by associate editor Aba Losi joined by guest editors Margaret Ahmad and John Christie. The remainder of the papers fell in to the broader classifications chosen for the meeting: Photomedicine and Human Photobiology (in which contributions on ocular photobiology edited by Joan Roberts are included), Plants (including a theme on Light Harvesting and Photoprotection in Photosynthetic organisms edited by Diana Kirilovsky and Noam Adir), Photodynamic Therapy and Physical and Chemical Photobiology.