Impact of UV Radiation on Genome Stability and Human Health

Melanin-based color variation in response to changing climates in snakes

Melanism, the process of heavier melanin deposition, can interact with climate variation at both micro and macro scales, ultimately influencing color evolution in organisms. While the ecological processes regulating melanin production in relation to climate have been extensively studied, intraspecific variations of melanism are seldom considered. Such scientific gap hampers our understanding of how species adapt to rapidly changing climates. For example, dark coloration may lead to higher heat absorption and be advantageous in cool climates, but also in hot environments as a UV or antimicrobial protection mechanism. To disentangle such opposing predictions, here we examined the effect of climate on shaping melanism variation in 150 barred grass snakes (Natrix helvetica) and 383 green whip snakes (Hierophis viridiflavus) across Italy. By utilizing melanistic morphs (charcoal and picturata in N. helvetica, charcoal and abundistic in H. viridiflavus) and compiling observations from 2002 to 2021, we predicted that charcoal morphs in H. viridiflavus would optimize heat absorption in cold environments, while offering protection from excessive UV radiation in N. helvetica within warm habitats; whereas picturata and abundistic morphs would thrive in humid environments, which naturally have a denser vegetation and wetter substrates producing darker ambient light, thus providing concealment advantages. While picturata and abundistic morphs did not align with our initial humidity expectations, the charcoal morph in N. helvetica is associated with UV environments, suggesting protection mechanisms against damaging solar radiation. H. viridiflavus is associated with high precipitations, which might offer antimicrobial protection. Overall, our results provide insights into the correlations between melanin-based color morphs and climate variables in snake populations. While suggestive of potential adaptive responses, future research should delve deeper into the underlying mechanisms regulating this relationship.

Advancements in sunscreen formulations: integrating polyphenolic nanocarriers and nanotechnology for enhanced UV protection

Sunscreens are essential in protecting the skin from harmful effects of ultraviolet radiation (UVR). These formulations, designed to absorb, block, or scatter UVR, offer vital protection against skin aging, sunburns, and the development of skin cancers like melanomas. However, some sunscreens, especially those containing organic/chemical compounds, can cause allergic reactions. To address this, researchers are extensively investigating formulations that incorporate plant extracts rich in polyphenols, such as flavonoids and carotenoids, which can be considered safer alternatives. Products derived from plants are commonly used in cosmetics to counteract skin aging due to their antioxidant activity that combat harmful free radicals. This review focuses on evaluating the advancements in chemical and natural sunscreens, exploring the integration of polyphenolic nanocarriers within sunscreen formulas, their interaction with UVR, and utilizing nanotechnology to enhance their effectiveness. An attempt has been made to highlight the concerns related to toxicity associated with their use and notable advancements in the regulatory aspects governing their utilization.

SscA is required for fungal development, aflatoxin production, and pathogenicity in Aspergillus flavus

Fungal spores are specialized dormant cells that act as primary reproductive biological particles and exhibit strong viability under extremely harsh conditions. They contaminate a variety of crops and foods, causing severe health hazards to humans and animals. Previous studies demonstrated that a spore-specific transcription factor SscA plays pivotal roles in the conidiogenesis of the model organism Aspergillus nidulans. In this study, we investigated the biological and genetic functions of SscA in the aflatoxin-producing fungus A. flavus. Deletion of sscA showed reduced conidia formation, lost long-term viability, and exhibited more sensitivity to thermal, oxidative, and radiative stresses. The sscA-deficient strain showed increased aflatoxin B1 production in conidia as well as mycelia. Importantly, the absence of sscA affected fungal pathogenicity on crops. Further transcriptomic and phenotypic studies suggested that SscA coordinates conidial wall structures. Overall, SscA is important for conidial formation, maturation and dormancy, mycotoxin production, and pathogenicity in A. flavus.

Antioxidants in Photoaging: From Molecular Insights to Clinical Applications

Photoaging (PA) is considered a silent disease affecting millions of people globally and is defined as skin damage due to prolonged exposure to ultraviolet radiation (UVR) from the sun. Physiologically, the skin is in a state of renewal and synthesis of components of the extracellular matrix (ECM). However, exposure to UVR affects the production of the ECM, and the functioning and response of skin cells to UVR begins to change, thus expressing clinical and phenotypic characteristics of PA. The primary mechanisms involved in PA are direct damage to the DNA of skin cells, increases in oxidative stress, the activation of cell signaling pathways responsible for the loss of skin integrity, and cytotoxicity. The medical and scientific community has been researching new therapeutic tools that counteract PA, considering that the damage caused by UVR exceeds the antioxidant defense mechanisms of the skin. Thus, in recent years, certain nutraceuticals and phytochemicals have been found to exhibit potential antioxidant and photoprotective effects. Therefore, the main objective of this review is to elucidate the molecular bases of PA and the latest pharmaceutical industry findings on antioxidant treatment against the progression of PA.

Rapamycin protects mouse skin from ultraviolet B-induced photodamage by modulating Hspb2-mediated autophagy and apoptosis

BACKGROUND

Continuous exposure to UVB is the main extrinsic cause of skin photodamage, which is associated with oxidative stress, DNA damage, apoptosis and degradation of collagen. Rapamycin, a mechanistic target inhibitor of rapamycin complex 1 (mTORC1), has been shown to play a crucial role anti-tumor and aging retardation, but its mechanism of action in UVB-induced photodamage still remains unknown. In this study, we investigated the role of rapamycin and Hspb2 (also known as Hsp27) in UVB-induced photodamage in mice.

METHODS AND RESULTS

We constructed skin acute photodamage models on the ears of WT and Hspb2 KO mice, respectively, and administered rapamycin treatment. Histological results showed that knockout of the hspb2 exacerbated the skin damage, as evidenced by thickening of the epidermis, breakage and disruption of collagen fibers and reduction in their number, which is reversed by rapamycin treatment. In addition, hspb2 knockout promoted UVB-induced apoptosis and reduced autophagy levels, with a significant increase in p53 levels and Bax/Bcl-2 ratio, a reduction in LC3II/I ratio and an increase in p62 levels in the KO mice compared to those in WT mice after the same dose of UVB irradiation. Rapamycin was also found to inhibit collagen degradation induced by hspb2 knockdown through activation of the TGF-β/Smad signaling pathway.

CONCLUSIONS

Rapamycin can alleviate skin photodamage from Hspb2 knockout to some extent. It may be a potential therapeutic drug for skin photodamage. In this study, we investigated the role of rapamycin and Hspb2 in UVB-induced photodamage in mice. Histological results showed that knockout of the hspb2 exacerbated the skin damage, as evidenced by thickening of the epidermis, breakage and disruption of collagen fibers and reduction in their number, which is reversed by rapamycin treatment. In addition, hspb2 knockout promoted UVB-induced apoptosis and reduced autophagy levels. Rapamycin was also found to inhibit collagen degradation induced by hspb2 knockdown through activation of the TGF-β/Smad signaling pathway. We conclude that rapamycin and Hspb2 exert a synergistic protective effect in skin photodamage.

Photoinactivation of the bacteriophage PhiX174 by UVA radiation and visible light in SM buffer and DMEM-F12

OBJECTIVE

It has been observed that viruses can be inactivated by UVA radiation and visible light. The aim of this study is to investigate whether a medium that contains a photosensitizer might have an influence on viral reduction under irradiation by UVA, violet or blue light. Test virus is the bacteriophage PhiX174 in the photosensitizer-free SM buffer and DMEM-F12, which contains the known photosensitizer riboflavin.

RESULTS

The determined PhiX174 D90 doses in SM buffer and DMEM were 36.8 J/cm² and 13.6 J/cm² at 366 nm, 153.6 J/cm² and 129.1 J/cm² at 408 nm and 4988 J/cm² and 2477.1 J/cm² at 455 nm, respectively. It can be concluded that the medium has a large influence on the results. This might be caused by the photosensitizer riboflavin in DMEM-F12. As riboflavin is a key component in many cell culture media, irradiation experiments with viruses in cell culture media should be avoided if the investigation of intrinsical photoinactivation properties of viruses is aimed for.

Identifying Suitable Reference Gene Candidates for Quantification of DNA Damage-Induced Cellular Responses in Human U2OS Cell Culture System

DNA repair pathways trigger robust downstream responses, making it challenging to select suitable reference genes for comparative studies. In this study, our goal was to identify the most suitable housekeeping genes to perform comparable molecular analyses for DNA damage-related studies. Choosing the most applicable reference genes is important in any kind of target gene expression-related quantitative study, since using the housekeeping genes improperly may result in false data interpretation and inaccurate conclusions. We evaluated the expressional changes of eight well-known housekeeping genes (i.e., 18S rRNA, B2M, eEF1α1, GAPDH, GUSB, HPRT1, PPIA, and TBP) following treatment with the DNA-damaging agents that are most frequently used: ultraviolet B (UVB) non-ionizing irradiation, neocarzinostatin (NCS), and actinomycin D (ActD). To reveal the significant changes in the expression of each gene and to determine which appear to be the most acceptable ones for normalization of real-time quantitative polymerase chain reaction (RT-qPCR) data, comparative and statistical algorithms (such as absolute quantification, Wilcoxon Rank Sum Test, and independent samples T-test) were conducted. Our findings clearly demonstrate that the genes commonly employed as reference candidates exhibit substantial expression variability, and therefore, careful consideration must be taken when designing the experimental setup for an accurate and reproducible normalization of RT-qPCR data. We used the U2OS cell line since it is generally accepted and used in the field of DNA repair to study DNA damage-induced cellular responses. Based on our current data in U2OS cells, we suggest using 18S rRNA, eEF1α1, GAPDH, GUSB, and HPRT1 genes for UVB-induced DNA damage-related studies. B2M, HPRT1, and TBP genes are recommended for NCS treatment, while 18S rRNA, B2M, and PPIA genes can be used as suitable internal controls in RT-qPCR experiments for ActD treatment. In summary, this is the first systematic study using a U2OS cell culture system that offers convincing evidence for housekeeping gene selection following treatment with various DNA-damaging agents. Here, we unravel an indispensable issue for performing and assessing trustworthy DNA damage-related differential gene expressional analyses, and we create a "zero set" of potential reference gene candidates.

Nucleic Acids Persistence-Benefits and Limitations in Forensic Genetics

The analysis of genetic material may be the only way to identify an unknown person or solve a criminal case. Often, the conditions in which the genetic material was found determine the choice of the analytical method. Hence, it is extremely important to understand the influence of various factors, both external and internal, on genetic material. The review presents information on DNA and RNA persistence, depending on the chemical and physical factors affecting the genetic material integrity. One of the factors taken into account is the time elapsing to genetic material recovery. Temperature can both preserve the genetic material or lead to its rapid degradation. Radiation, aquatic environments, and various types of chemical and physical factors also affect the genetic material quality. The substances used during the forensic process, i.e., for biological trace visualization or maceration, are also discussed. Proper analysis of genetic material degradation can help determine the post-mortem interval (PMI) or time since deposition (TsD), which may play a key role in criminal cases.

Light-driven textile sensors with potential application of UV detection

Smart textiles based on monitoring systems of health conditions, structural behaviour, and external environmental conditions have been presented as elegant solutions for the increasing demands of health care. In this study, cotton fabrics (CFs) were modified by a common strategy with a dipping-padding procedure using reduced graphene oxide (RGO) and a photosensitive dye, spiropyran (SP), which can detect environmental UV light. The morphology of the CF is observed by scanning electron microscopy (SEM) measurements showing that the topography structure of coatings is related to the SP content. The resistance of the textile sensors decreases after UV radiation, which may be attributed to the easier electron transmission on the coatings of the CF. With the increase of SP content, the introduction of a large amount of SP within the composites could cause discontinuous distributions of RGO in the fiber surfaces, preventing electron transmission within the coatings of the RGO. The surface wettability of the coatings and the sweat sensitivity are also studied before and after UV radiation.

UV-induced skin's green autofluorescence is a biomarker for both non-invasive evaluations of the dosages of UV exposures of the skin and non-invasive prediction of UV-induced skin damage

It is crucial to discover biomarkers for non-invasive evaluations of the dosages of UV exposures to a person during post-UV exposure period, and for non-invasive prediction of UV-induced skin damage. Our current study has obtained findings: UVB exposures produced dose-dependent increases in skin's green autofluorescence (AF) intensity of mice, which were significantly associated with the UVB dosages. The UVC-induced green AF increases were dose dependent, which were highly associated with the UVC dosages. Moreover, both previous reports and our current study have collectively shown significant association between UVB/UVC dosages and UVB/UVC-induced skin damage. Collectively, our study has indicated that the UVB/UVC-induced skin's AF are first biomarkers for both non-invasive evaluations of the dosages of UV exposures to a person during post-UV exposure period and non-invasive and label-free prediction of UVB/UVC-induced skin damage.

Plant responses to UV-B radiation: signaling, acclimation and stress tolerance

Ultraviolet-B (UV-B) light is an intrinsic part of sunlight that reaches the earth's surface, and affects plant survival and adaptation. How plants respond to UV-B light is regulated by the wavelength, intensity and duration of UV-B radiation, and is also regulated by photosynthetically active radiation perceived by phytochrome and cryptochrome photoreceptors. Non-damaging UV-B light promotes plant photomorphogenesis and UV-B acclimation which enhances plant tolerance against UV-B stress. However, high-level UV-B radiation induces DNA damage, generates reactive oxygen species (ROS) and impairs photosynthesis. Plants have evolved efficient mechanisms to utilize informational UV-B signal, and protect themselves from UV-B stress. UV RESISTANCE LOCUS8 (UVR8) is a conserved plant-specific UV-B photoreceptor. It interacts with CONSTITUTIVELY PHOTOMORPHOGENIC1 (COP1) to initiate UV-B-specific light signaling and regulate UV-B responsive gene expression. A set of transcription factors such as ELONGATED HYPOCOTYL5 (HY5) function downstream of the UVR8-COP1 module to promote seedling de-etiolation for photomorphogenic development and biosynthesis of sunscreen flavonoids for UV-B stress tolerance. In addition to UVR8 signaling pathways, plants subjected to damaging UV-B radiation initiate stress protection and repair mechanisms through UVR8-independent pathways. In this review, we summarize the emerging mechanisms underlying UV-B stress acclimation and protection in plants, primarily revealed in the model plant Arabidopsis thaliana.

The enigma of ultraviolet radiation stress granules: Research challenges and new perspectives

Stress granules (SGs) are non-membrane bound cytoplasmic condensates that form in response to a variety of different stressors. Canonical SGs are thought to have a cytoprotective role, reallocating cellular resources during stress by activation of the integrated stress response (ISR) to inhibit translation and avoid apoptosis. However, different stresses result in compositionally distinct, non-canonical SG formation that is likely pro-apoptotic, though the exact function(s) of both SGs subtypes remain unclear. A unique non-canonical SG subtype is triggered upon exposure to ultraviolet (UV) radiation. While it is generally agreed that UV SGs are bona fide SGs due to their dependence upon the core SG nucleating protein Ras GTPase-activating protein-binding protein 1 (G3BP1), the localization of other key components of UV SGs are unknown or under debate. Further, the dynamics of UV SGs are not known, though unique properties such as cell cycle dependence have been observed. This Perspective compiles the available information on SG subtypes and on UV SGs in particular in an attempt to understand the formation, dynamics, and function of these mysterious stress-specific complexes. We identify key gaps in knowledge related to UV SGs, and examine the unique aspects of their formation. We propose that more thorough knowledge of the distinct properties of UV SGs will lead to new avenues of understanding of the function of SGs, as well as their roles in disease.

Impaired Fanconi anemia pathway causes DNA hypomethylation in human angiosarcomas

Angiosarcomas (AS) is a rare soft tissue sarcomas with poor treatment options and a dismal prognosis. The abnormal DNA methylation pattern has been determined as the certain clinical relevance with different angiosarcoma subtypes. However, the profound mechanism is not clear. In present study, we studied thirty-six AS with or without chronic lymphedema, and reported that DNA damage was an important factor causing DNA methylation abnormality. Furthermore, we determined that the impaired Fanconi anemia (FA) pathway contributed to severe DNA damage in AS with chronic lymphedema. We also observed that the activated FANCD2 could facilitate DNMT1 recruitment on genomic DNA. Our study uncovers a novel regulatory mechanism of FA pathway on DNA methylation, and is a benefit to advanced understanding the pathogenesis of AS, as well as providing the potential therapeutic targets for AS treatment.

Facile Preparation of Silk Fabrics with Enhanced UV Radiation Shielding and Wrinkle Resistance by Cross-Linking Light-Responsive Copolymers

Enhanced UV radiation shielding is realized by cross-linking the light-responsive copolymer poly(di(ethylene glycol)methyl ether methacrylate-co-oligo(ethylene glycol)methyl ether methacrylate-co-ethylene glycol methacrylate-co-6-(4-phenylazo-phenoxy)hexyl methacrylate), abbreviated as PMOEA, with silk fabrics. Owing to the existence of the azobenzene component in 6-(4-phenylazo-phenoxy)hexyl methacrylate, UV radiation can be significantly absorbed in an aqueous PMOEA solution by the trans-cis isomerization of azobenzene. After immobilization onto the silk fabrics by the cross-linker 1,2,3,4-butanetetracarboxylic acid, the cross-linked copolymer-coated silk fabrics present an enhanced capability of UV radiation absorption. More than 70% of the UV radiation is efficiently shielded by the cross-linked copolymer-coated silk fabrics, which is double that of the original silk fabrics. Considering the limited amount of the light-responsive copolymer applied (5 wt %), UV protection is successfully realized for the silk fabrics. In addition, the cross-linked copolymer layer also forms covalent bonds with the hydroxyl and amino groups on the silk fabrics. Wrinkles on the silk fabrics, typically caused by the movement of the silk chains, are suppressed by the formed covalent bonds, significantly hindering such chain movement. Therefore, the wrinkle resistance capability is also improved by cross-linking PMOEA on silk fabrics. As the glass transition temperature of the copolymer is lower than room temperature, the hand feel of silk fabrics is not affected by the cross-linking layer. Based on these advantages, the cross-linked copolymer-coated silk fabrics can be used for light clothes to shield against UV radiation from the sun during outdoor activities in summer.

Light-activated molecular machines are fast-acting broad-spectrum antibacterials that target the membrane

The increasing occurrence of antibiotic-resistant bacteria and the dwindling antibiotic research and development pipeline have created a pressing global health crisis. Here, we report the discovery of a distinctive antibacterial therapy that uses visible (405 nanometers) light-activated synthetic molecular machines (MMs) to kill Gram-negative and Gram-positive bacteria, including methicillin-resistant Staphylococcus aureus, in minutes, vastly outpacing conventional antibiotics. MMs also rapidly eliminate persister cells and established bacterial biofilms. The antibacterial mode of action of MMs involves physical disruption of the membrane. In addition, by permeabilizing the membrane, MMs at sublethal doses potentiate the action of conventional antibiotics. Repeated exposure to antibacterial MMs is not accompanied by resistance development. Finally, therapeutic doses of MMs mitigate mortality associated with bacterial infection in an in vivo model of burn wound infection. Visible light-activated MMs represent an unconventional antibacterial mode of action by mechanical disruption at the molecular scale, not existent in nature and to which resistance development is unlikely.

Ozone Layer Depletion and Emerging Public Health Concerns - An Update on Epidemiological Perspective of the Ambivalent Effects of Ultraviolet Radiation Exposure

Solar ultraviolet (UV) radiation exposure is the primary etiological agent responsible for developing cutaneous malignancies. Avoiding excessive radiation exposure, especially by high-risk groups, is recommended to prevent UV-induced photo-pathologies. However, optimal sun exposure is essential for the healthy synthesis of about 90% of vitamin D levels in the body. Insufficient exposure to UV-B is linked to vitamin D deficiency in humans. Therefore, optimal sun exposure is necessary for maintaining a normal state of homeostasis in the skin. Humans worldwide face a major existential threat because of climate change which has already shown its effects in several ways. Over the last 4 to 5 decades, increased incidences in skin cancer cases have led international health organizations to develop strong sun protection measures. However, at the same time, a growing concern about vitamin D deficiency is creating a kind of exposure dilemma. Current knowledge of UV exposure to skin outweighs the adverse effects than the beneficial roles it offers to the body, necessitating a correct public health recommendation on optimal sun exposure. Following an appropriate recommendation on optimal sun exposure will lead to positive outcomes in protecting humans against the adverse effects of strict recommendations on sun protection measures. In this short review, we spotlight the ambivalent health effects of UV exposure and how ozone layer depletion has influenced these effects of UVR. Further, our aim remains to explore how to lead towards a balanced recommendation on sun protection measures to prevent the spurt of diseases due to inadequate exposure to UV-B.

The effect of ultraviolet radiation on the incidence and severity of major mental illness using birth month, birth year, and sunspot data

Background and objectives

The evaluation of the severity of patients afflicted with major mental illness (MMI) has been problematic because of confounding variables and genetic variability. There have been multiple studies that suggest several human diseases, especially schizophrenia, are predisposed to be born in certain months or seasons. This observation implied an epigenetic effect of sunlight, likely ultraviolet radiation (UVR), which is damaging to DNA, especially in an embryo. This paper outlines a method to evaluate the severity of schizophrenia (SZ), bipolar disorder (BPD), and schizoaffective disorder (SZ-AFF) using the month/year of birth of those affected compared to the month/year of birth of the general population (GP).

Relevance

Our previous research found that more intense UVR (equal to or greater than 90 sunspot number (SSN)) had a negative effect on the average human lifespan. Also, human birth rates vary in frequency by month of birth reflecting variables like availability of food, sunlight, and other unknown epigenetic factors. We wanted to see if the patient month of birth varied from the average birth months of the general population and if UVR has an epigenetic effect promoting these diseases.

Methods

We obtained the month and year of birth of 1,233 patients admitted over a 15-year period to Maine's largest state psychiatric hospital and counted the months of birth for each diagnosis of SZ, BPD, and SZ-AFF, and compared these results to the general population's birth months of 4,265,555 persons from U. S. Census Year 2006. The number of patients in each month was normalized to August and compared with the normalized birth months of the general population (GP). Plots of the normalized months were considered rates of change (e.g., derivatives) and their respective integrals gave domains of each mental illness relative to the GP. Normalizing the GP to unity was then related to the factor 1.28, e.g., 28% more entropy, deduced from the Sun's fractal dimension imprinted on biological organisms.

Results

The percent of patients meeting our criterion for severity: SZ = 27%; BPD = 26%; SZ-AFF = 100%.

Conclusions

High UVR intensity or a rapid increase in UVR in early gestation are likely epigenetic triggers of major mental illness. BPD is more epigenetically affected than SZ or SZ-AFF disorders. We found that 52% of 1,233 patients comprised the core function of a tertiary-care psychiatric hospital. Also, mental illness exacerbated when the median SSN doubled. This work also validates the Kraeplinian dichotomy.

What is new in this research

This paper offers a new paradigm for evaluating the severity of MMI and supports significant epigenetic effects from UVR.

Metnase and EEPD1: DNA Repair Functions and Potential Targets in Cancer Therapy

Cells respond to DNA damage by activating signaling and DNA repair systems, described as the DNA damage response (DDR). Clarifying DDR pathways and their dysregulation in cancer are important for understanding cancer etiology, how cancer cells exploit the DDR to survive endogenous and treatment-related stress, and to identify DDR targets as therapeutic targets. Cancer is often treated with genotoxic chemicals and/or ionizing radiation. These agents are cytotoxic because they induce DNA double-strand breaks (DSBs) directly, or indirectly by inducing replication stress which causes replication fork collapse to DSBs. EEPD1 and Metnase are structure-specific nucleases, and Metnase is also a protein methyl transferase that methylates histone H3 and itself. EEPD1 and Metnase promote repair of frank, two-ended DSBs, and both promote the timely and accurate restart of replication forks that have collapsed to single-ended DSBs. In addition to its roles in HR, Metnase also promotes DSB repair by classical non-homologous recombination, and chromosome decatenation mediated by TopoIIα. Although mutations in Metnase and EEPD1 are not common in cancer, both proteins are frequently overexpressed, which may help tumor cells manage oncogenic stress or confer resistance to therapeutics. Here we focus on Metnase and EEPD1 DNA repair pathways, and discuss opportunities for targeting these pathways to enhance cancer therapy.

Molecular characterization of stress tolerance genes associated with D. indicus strain under extreme environment conditions

Deinococcus indicus is a novel bacteria isolated from West Bengal, India known for its UV radiation and heavy metal tolerance. Since, this organism is reported from a region known for heavy metal contamination and earlier investigations demonstrated its radiation resistance, our study focused on the multiple stress responsive and DNA repair mechanisms. Though, most of the members of the genus Deinococcus are Gram positive cocci, D. indicus postures Gram negative rod shaped cells. Hence, the objectives were framed precisely to understand DNA repair pathway and stress responsive genes expression with a broader perspective. Based on available whole genome sequence of D. indicus, quantitative real time PCR (qPCR) was done to determine the expression pattern of multiple stress responsive genes upon various environmental extremities. Among them, UV responsive genes like UvrD and UvsE showed elevated expression when subjected to UV-C radiation at different time intervals. Similarly, when supplemented with arsenic and chromium, ArsR and ArsB exhibited considerably higher level of expression. While all the genes were subsequently analyzed in-silico, depicted that most of them were with N-glycosylation site, GPI anchor sites, N-terminal trans-membrane helix region besides putative signal peptides. Overall, this study opined the functional information on stress tolerance genes that aid to understand the DNA damage recovery mechanism towards elucidation of DNA repair pathways.

Effects of photodeoxygenation on cell biology using dibenzothiophene S-oxide derivatives as O(3P)-precursors

Photodeoxygenation of dibenzothiophene S-oxide and its derivatives have been used to generate atomic oxygen [O(³P)] to examine its effect on proteins, nucleic acids, and lipids. The unique reactivity and selectivity of O(³P) have shown distinct oxidation products and outcomes in biomolecules and cell-based studies. To understand the scope of its global impact on the cell, we treated MDA-MB-231 cells with 2,8-diacetoxymethyldibenzothiophene S-oxide and UV-A light to produce O(³P) without targeting a specific cell organelle. Cellular responses to O(³P)-release were analyzed using cell viability and cell cycle phase determination assays. Cell death was observed when cells were treated with higher concentrations of sulfoxides and UV-A light. However, significant differences in cell cycle phases due to UV-A irradiation of the sulfoxide were not observed. We further performed RNA-Seq analysis to study the underlying biological processes at play, and while UV-irradiation itself influenced gene expression, there were 9 upregulated and 8 downregulated genes that could be attributed to photodeoxygenation.

Visible blue light inhibits infection and replication of SARS-CoV-2 at doses that are well-tolerated by human respiratory tissue

The delivery of safe, visible wavelengths of light can be an effective, pathogen-agnostic, countermeasure that would expand the current portfolio of SARS-CoV-2 intervention strategies beyond the conventional approaches of vaccine, antibody, and antiviral therapeutics. Employing custom biological light units, that incorporate optically engineered light-emitting diode (LED) arrays, we harnessed monochromatic wavelengths of light for uniform delivery across biological surfaces. We demonstrated that primary 3D human tracheal/bronchial-derived epithelial tissues tolerated high doses of a narrow spectral band of visible light centered at a peak wavelength of 425 nm. We extended these studies to Vero E6 cells to understand how light may influence the viability of a mammalian cell line conventionally used for assaying SARS-CoV-2. The exposure of single-cell monolayers of Vero E6 cells to similar doses of 425 nm blue light resulted in viabilities that were dependent on dose and cell density. Doses of 425 nm blue light that are well-tolerated by Vero E6 cells also inhibited infection and replication of cell-associated SARS-CoV-2 by > 99% 24 h post-infection after a single five-minute light exposure. Moreover, the 425 nm blue light inactivated cell-free betacoronaviruses including SARS-CoV-1, MERS-CoV, and SARS-CoV-2 up to 99.99% in a dose-dependent manner. Importantly, clinically applicable doses of 425 nm blue light dramatically inhibited SARS-CoV-2 infection and replication in primary human 3D tracheal/bronchial tissue. Safe doses of visible light should be considered part of the strategic portfolio for the development of SARS-CoV-2 therapeutic countermeasures to mitigate coronavirus disease 2019 (COVID-19).

The Tardigrade Damage Suppressor Protein Modulates Transcription Factor and DNA Repair Genes in Human Cells Treated with Hydroxyl Radicals and UV-C

Simple Summary

The Ramazzottius varieornatus is known to be the most resilient invertebrate on Earth. Belonging to the phylum of Tardigrada, it can live in any habitat, from the deep sea to various terrestrial environments, surviving in extreme temperatures, severe dryness or air deprivation. This exceptional tolerance to extreme conditions is attributable to the Dsup protein, which is able to bind and “protect” the DNA of this micro-animal, allowing it to survive where most other forms of life would quickly die. By introducing Dsup in human cell cultures, we investigated how this protein operates in response to two different extreme conditions: oxidative stress and ultraviolet (UV) irradiation. We learned that Dsup increases cell survival by triggering significantly different cellular mechanisms. In cells treated with hydrogen peroxide, Dsup “physically” protects DNA and activates several detoxification pathways aimed to remove intracellular free radicals. In contrast to this, a direct protection of DNA is not exerted by Dsup after UV irradiation, but the protein seems to activate mechanisms of DNA damage repair more efficiently, promoting faster cell recovery and survival. Even though further studies are required, understanding the mechanisms associated with Dsup resistance to cell damage may represent an important benefit for humans and plants.

Abstract

The Ramazzottius varieornatus tardigrade is an extremotolerant terrestrial invertebrate with a length of 0.1–1.0 mm. These small animals show an extraordinary tolerance to extreme conditions such as high pressure, irradiation, chemicals and dehydration. These abilities are linked to a recently discovered damage suppressor protein (Dsup). Dsup is a nucleosome-binding protein that avoids DNA damage after X-ray and oxidative stress exposure without impairing cell life in Dsup-transfected animal and plant cells. The exact “protective” role of this protein is still under study. In human cells, we confirmed that Dsup confers resistance to UV-C and H₂O₂ exposure compared to untransfected cells. A different transcription factor activation was also observed. In addition, a different expression of endogenous genes involved in apoptosis, cell survival and DNA repair was found in Dsup+ cells after H₂O₂ and UV-C. In UV-C exposed cells, Dsup efficiently upregulates DNA damage repair genes, while H₂O₂ treatment only marginally involves the activation of pathways responsible for DNA repair in Dsup+ cells. These data are in agreement with the idea of a direct protective effect of the protein on DNA after oxidative stress. In conclusion, our data may help to outline the different mechanisms by which the Dsup protein works in response to different insults.

Multi-Omics Approaches and Radiation on Lipid Metabolism in Toothed Whales

Lipid synthesis pathways of toothed whales have evolved since their movement from the terrestrial to marine environment. The synthesis and function of these endogenous lipids and affecting factors are still little understood. In this review, we focused on different omics approaches and techniques to investigate lipid metabolism and radiation impacts on lipids in toothed whales. The selected literature was screened, and capacities, possibilities, and future approaches for identifying unusual lipid synthesis pathways by omics were evaluated. Omics approaches were categorized into the four major disciplines: lipidomics, transcriptomics, genomics, and proteomics. Genomics and transcriptomics can together identify genes related to unique lipid synthesis. As lipids interact with proteins in the animal body, lipidomics, and proteomics can correlate by creating lipid-binding proteome maps to elucidate metabolism pathways. In lipidomics studies, recent mass spectroscopic methods can address lipid profiles; however, the determination of structures of lipids are challenging. As an environmental stress, the acoustic radiation has a significant effect on the alteration of lipid profiles. Radiation studies in different omics approaches revealed the necessity of multi-omics applications. This review concluded that a combination of many of the omics areas may elucidate the metabolism of lipids and possible hazards on lipids in toothed whales by radiation.

Identifying cysteine residues susceptible to oxidation by photoactivatable atomic oxygen precursors using a proteome-wide analysis

The reactivity profile of atomic oxygen [O(3P)] in the condensed phase has shown a preference for the thiol group of cysteines. In this work, water-soluble O(3P)-precursors were synthesized by adding aromatic burdens and water-soluble sulphonic acid groups to the core structure of dibenzothiophene-S-oxide (DBTO) to study O(3P) reactivity in cell lysates and live cells. The photodeoxygenation of these compounds was investigated using common intermediates, which revealed that an increase in aromatic burdens to the DBTO core structure decreases the total oxidation yield due to competitive photodeoxygenation mechanisms. These derivatives were then tested in cell lysates and live cells to profile changes in cysteine reactivity using the isoTOP-ABPP chemoproteomics platform. The results from this analysis indicated that O(3P) significantly affects cysteine reactivity in the cell. Additionally, O(3P) was found to oxidize cysteines within peptide sequences with leucine and serine conserved at the sites surrounding the oxidized cysteine. O(3P) was also found to least likely oxidize cysteines among membrane proteins.

A photoelectrochemical enzyme biosensor based on functionalized hematite microcubes for rutin determination by square-wave voltammetry

A photoelectrochemical biosensing strategy for the highly sensitive detection of the flavonoid rutin was developed by synergizing the photoelectrocatalytic properties of hematite (α-Fe₂O₃) decorated with palladium nanoparticles (PdNPs) and the biocatalysis towards laccase-based reactions. The integration of α-Fe₂O₃.PdNPs with a polyphenol oxidase as a biorecognition element yields a novel biosensing platform. Under visible light irradiation, the photoactive biocomposite can generate a stable photocurrent, which was found to be directly dependent upon the concentration of rutin. Under the optimal experimental conditions, the cathodic photocurrent, measured at 0.33 V vs. Ag/AgCl, from the square-wave voltammograms presented a linear dependence on the rutin concentration within the range of 0.008-30.0 × 10^-8 mol L^-1 (sensitivity: 1.7 μA·(× 10^-8 M^-1)·cm^-2), with an experimental detection limit (S/N = 3) of 8.4 × 10^-11 mol L^-1. The proposed biosensor device presented good selectivity towards rutin in the presence of various organic compounds and inorganic ions, demonstrating the potential application of this biosensing platform in complex matrices. This bioanalytical device also exhibited excellent operational and analytical properties, such as intra-day (standard deviation, SD = 0.21%) and inter-day (SD = 1.30%) repeatability, and long storage stability (SD = 2.80% over 30 days).Graphical abstract.

Topical Oral and Intranasal Antiviral Agents for Coronavirus Disease 2019 (COVID-19)

With the largest viral loads in both symptomatic and asymptomatic patients with Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) present in the oral and nasal cavities, agents that act on these two areas have the potential for large therapeutic and prophylactic benefit. A literature review was conducted to elucidate the possible agents useful in treatment of SARS-CoV-2. These agents were evaluated for their current applications, adverse reactions, their current state of study, and any future considerations in their management of coronavirus disease 2019 (COVID-2019). Our review has found that, while there are many promising agents with proven efficacy in their in-vitro efficacy against SARS-CoV-2, more clinical trials and in-vivo studies, as well as safety trials, must be conducted before these agents can be effectively implemented.

Next-generation DNA damage sequencing

Cellular DNA is constantly chemically altered by exogenous and endogenous agents. As all processes of life depend on the transmission of the genetic information, multiple biological processes exist to ensure genome integrity. Chemically damaged DNA has been linked to cancer and aging, therefore it is of great interest to map DNA damage formation and repair to elucidate the distribution of damage on a genome-wide scale. While the low abundance and inability to enzymatically amplify DNA damage are obstacles to genome-wide sequencing, new developments in the last few years have enabled high-resolution mapping of damaged bases. Recently, a number of DNA damage sequencing library construction strategies coupled to new data analysis pipelines allowed the mapping of specific DNA damage formation and repair at high and single nucleotide resolution. Strikingly, these advancements revealed that the distribution of DNA damage is heavily influenced by chromatin states and the binding of transcription factors. In the last seven years, these novel approaches have revealed new genomic maps of DNA damage distribution in a variety of organisms as generated by diverse chemical and physical DNA insults; oxidative stress, chemotherapeutic drugs, environmental pollutants, and sun exposure. Preferred sequences for damage formation and repair have been elucidated, thus making it possible to identify persistent weak spots in the genome as locations predicted to be vulnerable for mutation. As such, sequencing DNA damage will have an immense impact on our ability to elucidate mechanisms of disease initiation, and to evaluate and predict the efficacy of chemotherapeutic drugs.

Transdermal delivery of topical lidocaine in a mouse model is enhanced by treatment with cold atmospheric plasma

BACKGROUND

Topical anesthetics are widely used in dermatology and cosmetology to alleviate the pain from nonsurgical cosmetic procedures, while the transdermal drug delivery is limited by the skin barrier. Cold atmospheric plasma (CAP) is a potential approach used for skin pretreatment to enhance transdermal delivery of topical medications.

AIMS

To assess the efficacy of CAP as a pretreatment to improve the transdermal delivery of topical anesthetic.

METHODS

First, we conducted ex vivo permeation studies on 30 mice with a Franz cell diffusion experiment. CAP irradiations of different intensity and duration were pretreated on the epidermal layer of mice before topical lidocaine applied, with the control group received no pretreatment. The amount of drug penetrated through the skin and drug flux were determined by high-performance liquid chromatography. Then, we treated 3 living mice with CAP followed by application of methylene blue cream (MB) and used skin biopsies to measure penetration depth by microscope. Last, we measured the transepidermal water loss (TEWL) of mouse skin in vivo before and after CAP treatment to observe its effect on the skin barrier function.

RESULTS

In the permeation study, the transdermal flux of lidocaine was enhanced to 1.97 times of the control samples by CAP pretreatment. We also observed that the accumulative amount of lidocaine varied with the duration of the CAP treatment in a biphasic manner. In the MB penetration study, significant amount of MB deposition was observed under the epidermis and deeper parts of the skin after CAP pretreatment compared with the control sample. A sharp increase in TEWL value was observed directly after the CAP treatment, but 30 minutes later, it began to decrease and recovered to baseline in the next 3 hours, indicating that the skin barrier property had been changed reversibly.

CONCLUSIONS

Our studies suggested that the transdermal absorption of topical lidocaine can be efficiently and safely enhanced by pretreatment of the skin with CAP. We believe that CAP could be used as an assistance to improve analgesia in dermatology.

Ultraviolet A light effectively reduces bacteria and viruses including coronavirus

Antimicrobial-resistant and novel pathogens continue to emerge, outpacing efforts to contain and treat them. Therefore, there is a crucial need for safe and effective therapies. Ultraviolet-A (UVA) phototherapy is FDA-approved for several dermatological diseases but not for internal applications. We investigated UVA effects on human cells in vitro, mouse colonic tissue in vivo, and UVA efficacy against bacteria, yeast, coxsackievirus group B and coronavirus-229E. Several pathogens and virally transfected human cells were exposed to a series of specific UVA exposure regimens. HeLa, alveolar and primary human tracheal epithelial cell viability was assessed after UVA exposure, and 8-Oxo-2'-deoxyguanosine was measured as an oxidative DNA damage marker. Furthermore, wild-type mice were exposed to intracolonic UVA as an in vivo model to assess safety of internal UVA exposure. Controlled UVA exposure yielded significant reductions in Pseudomonas aeruginosa, Klebsiella pneumoniae, Escherichia coli, Enterococcus faecalis, Clostridioides difficile, Streptococcus pyogenes, Staphylococcus epidermidis, Proteus mirabilis and Candida albicans. UVA-treated coxsackievirus-transfected HeLa cells exhibited significantly increased cell survival compared to controls. UVA-treated coronavirus-229E-transfected tracheal cells exhibited significant coronavirus spike protein reduction, increased mitochondrial antiviral-signaling protein and decreased coronavirus-229E-induced cell death. Specific controlled UVA exposure had no significant effect on growth or 8-Oxo-2'-deoxyguanosine levels in three types of human cells. Single or repeated in vivo intraluminal UVA exposure produced no discernible endoscopic, histologic or dysplastic changes in mice. These findings suggest that, under specific conditions, UVA reduces various pathogens including coronavirus-229E, and may provide a safe and effective treatment for infectious diseases of internal viscera. Clinical studies are warranted to further elucidate the safety and efficacy of UVA in humans.

Applications of cold atmospheric plasma for transdermal drug delivery: a review

Although transdermal drug delivery would be very useful for the treatment of many diseases, in practice it is difficult to accomplish for the obstruction of the stratum corneum. The application of cold atmospheric plasma (CAP) as a pretreatment to the skin surface helps to enhance the delivery of topically applied drugs into the skin and the systemic circulation. CAP can change the skin properties to improve drug penetration by various different effects based on its multiple components. This review first introduces the skin barrier properties and some traditional transdermal drug delivery strategies. Next what is known about the application of CAP in transdermal drug delivery has been summarized, including the mechanisms and possible side effects. We believe that CAP could be developed as a non-invasive and efficient pretreatment to improve the transdermal permeation of drugs in clinical practice, although more research needs to be done to overcome the challenges. Graphical Abstract.

Updates on Treatment Approaches for Cutaneous Field Cancerization

Purpose of Review

Field cancerization describes the phenomenon that multiple heterogenous mutations may arise in an area exposed to chronic carcinogenic stimuli. Advances in the understanding of cutaneous field cancerization have led to novel therapeutic approaches to the management of actinic keratoses (AKs). Herein, we review the literature on the pathophysiology and emerging research of field cancerization in dermatology.

Recent Findings

The classification systems for grading AK lesions are being refined with investigations focusing on their clinical utility. There is a growing shift towards field-directed treatment for AKs as the importance of field cancerization becomes clearer. Current field-directed therapies are being optimized and novel therapeutic modalities are being studied.

Summary

Field cancerization underlies the transformation of photodamaged skin into AKs and potentially cutaneous SCC (cSCC). Clinically meaningful classification systems for AKs are needed to better inform decisions regarding treatment. As we learn more about the role of field characterization in photodamage, AKs and cSCCs, therapeutic strategies are becoming more field-directed rather than lesion-directed.

The Horizon of Gene Therapy in Modern Medicine: Advances and Challenges

Gene therapy as a novel study in molecular medicine will have a significant impact on human health in the near future. In recent years, the scope of gene therapy has been developed and is now beginning to revolutionize therapeutic approaches. Accordingly, many types of diseases are now being studied and treated in clinical trials through various gene delivery vectors. The emergence of recombinant DNA technology which provides the possibility of fetal genetic screening and genetic counseling is a good case in point. Therefore, gene therapy advances are being applied to correct inherited genetic disorders such as hemophilia, cystic fibrosis, and familial hypercholesterolemia as well as acquired diseases like cancer, AIDS, Alzheimer's disease, Parkinson's disease, and infectious diseases like HIV. As a result, gene therapy approaches have the ability to help the vast majority of newborns with different diseases. Since these ongoing treatments and clinical trials are being developed, many more barriers and challenges have been created. In order to continue this positive growth, these challenges need to be recognized and addressed. Accordingly, safety, efficiency and also risks and benefits of gene therapy trials for each disease should be considered. As a result, sustained manufacturing of the therapeutic gene product without any harmful side effects is the least requirement for gene therapy. Herein, different aspects of gene therapy, an overview of the progress, and also the prospects for the future have been discussed for the successful practice of gene therapy.