Themed collection The World Congress on Light and Life, Barcelona 2019

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.

Oral lichen planus (OLP) is a chronic inflammatory and immune-mediated disease affecting the oral mucosa.

This paper summarizes the recent possibilities to use measurements of ambient UV radiation for estimations of the personal UV exposure of people.

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.

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.

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.

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.

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.

Calculations are providing more and more useful insights into the interaction between light and DNA quadruplexes.

Perspective of research directions exploring purple bacteria photo-bioelectrochemistry: from harvesting photoexcited electrons to bioelectrochemical systems development.

Changes in relative abundance of bacterial phyla in faecal samples from humans and mice exposed to UV radiation.

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 TPCS_2a/fimaporfin.

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.

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.

The goal of this study was to characterize the effect of near-infrared light exposure on mitochondrial membrane potential, in vitro.

Xanthophylls in light harvesting complexes perform a number of functions ranging from structural support to light-harvesting and photoprotection.

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.

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.

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.

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.

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.

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).

In this study, we report for the first time the use of four aza-dipyrromethenes (ADPMs) as photosensitizers for cancer PDT.

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 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.

Blue light controls the expression of genes which are involved in behavioural responses of the cyanobacterium Synechocystis sp. PCC 6803.

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.

We report the construction of a single-component optogenetic Rac1 (opto-Rac1) to control actin polymerization by dynamic membrane recruitment.

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.

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.

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.