Search Results (460)

Skin aging is characterized by compromised epidermal homeostasis and dermo-epidermal junction (DEJ) integrity, resulting in reduced stem cell potential and impaired tissue regeneration. This study investigated the effects of Andrographis paniculata extract (APE) on keratinocyte stem cells (KSCs) and DEJ composition in human skin. Using human skin explants and cell culture models, we demonstrated that APE treatment enhances DEJ composition by increasing Collagen IV and Laminin production while decreasing MMP-9 expression, without altering epidermal structure or differentiation. In the same model, APE preserved stemness potential by upregulating markers related to niche components (collagen XVII and β1-integrin), proliferation (Ki-67 and KRT15), and stem cell capacity (Survivin and LRIG1). In vitro studies revealed that APE selectively stimulated KSC proliferation without affecting transit amplifying cells and promoted Collagen IV and Laminin secretion, particularly in KSCs. Furthermore, in a co-culture model simulating a compromised DEJ (UVB-induced), APE increased Laminin production in KSCs, suggesting a protective effect against photo-damage. These findings indicate that APE enhances DEJ composition and preserves stem cell potential, highlighting its promise as a candidate for skin anti-aging strategies targeting stem cell maintenance and extracellular matrix stability to promote skin regeneration and repair. Full article

Recreational diving depends on healthy marine ecosystems, yet it can harm biodiversity through species displacement and habitat damage. Bombinhas, a biodiverse diving hotspot in southern Brazil, faces growing threats from human activity and climate change. This study assessed the ecological structure of Sepultura Beach (2018) for potential diving trails, comparing it with historical data from Porto Belo Island. Using visual censuses, transects, and photo-quadrats across six sampling campaigns, researchers documented 2419 organisms from five zoological groups, identifying 14 dominant species, including Haemulon aurolineatum and Diplodus argenteus. Cluster analysis revealed three ecological zones, with higher biodiversity at the site’s edges (Groups 1 and 3), but these areas also hosted endangered species like Epinephelus marginatus, complicating trail planning. A major concern was the widespread bleaching of the zoanthid Palythoa caribaeorum, a key ecosystem engineer, likely due to rising sea temperatures (+1.68 °C from 1961–2018) and declining chlorophyll-a levels post-2015. Comparisons with past data showed a 0.33 °C increase in species’ thermal preferences over 17 years, alongside lower trophic levels and greater ecological vulnerability, indicating tropicalization from the expanding Brazil Current. While Sepultura Beach’s biodiversity supports diving tourism, conservation efforts must address coral bleaching and endangered species protection. Long-term monitoring is crucial to track warming impacts, and adaptive management is needed for sustainable trail development. The study highlights the urgent need to balance ecotourism with climate resilience in subtropical marine ecosystems. Full article

Modified oligonucleotides (oligos) are widely used as convenient tools in many scientific fields, including biomedical applications and therapies. In particular, oligos with lipophilic groups attached to the backbone ensure penetration of the cell membrane without the need for transfection. This study examines the interaction between amphiphilic DNA duplexes, in which one of the chains contains a lipophilic substituent, and several DNA repair proteins, particularly DNA-damage-dependent PARPs, using various biochemical approaches. DNA with a lipophilic substituent (LS-DNA) demonstrates more efficient binding with DNA damage activated poly(AD-ribose) polymerases 1-3 (PARP1, PARP2, PARP3) and DNA polymerase β. Chemically reactive LS-DNA derivatives containing a photoactivatable nucleotide (photo-LS-DNAs) or a 5′ deoxyribose phosphate (dRP) group in the vicinity of double-strand breaks (DSBs) are used for the affinity labelling of PARPs and other proteins in several whole-cell extracts of human cells. In particular, photo-LS-DNAs are used to track the level of Ku antigen in the extracts of neuron-like differentiated SH-SY5Y, undifferentiated SH-SY5Y, and olfactory epithelial cells. In vitro, PARP1–PARP3 are shown to be able to slowly excise the 5′ dRP group at DSBs. LS-DNAs can activate PARP1 and PARP2 for autoPARylation, albeit less effectively than regular DNA duplexes. Full article

Retinal degeneration is associated with dietary factors and environmental light exposure. This study investigated the effects of a high-fructose high-fat (HFHF) diet on susceptibility to blue light (BL)-induced retinal damage. Male ICR mice were randomized into three groups: control, BL alone, and BL plus HFHF diet (BL + HFHF). The BL + HFHF group consumed the HFHF diet for 40 weeks, followed by 8 weeks of low-intensity BL exposure (465 nm, 37.7 lux, 0.8 μW/cm²) for 6 h daily. The BL group underwent the same BL exposure while kept on a standard diet. Histopathological analysis showed that, under BL exposure, the HFHF diet significantly reduced the number of photoreceptor nuclei and the thickness of the outer nuclear layer and inner/outer segments compared to the BL group (p < 0.05). While BL exposure alone caused oxidative DNA damage, rhodopsin loss, and Müller cell activation, the combination with an HFHF diet significantly amplified the oxidative DNA damage and Müller cell activation. Moreover, the HFHF diet increased blood–retinal barrier permeability and triggered apoptosis under BL exposure. Mechanistically, the BL + HFHF group exhibited increased retinal advanced glycated end product (AGE) deposition, accompanied by the activation of the receptor for AGE (RAGE), NFκB, and the NLRP3 inflammasome-dependent IL-1β pathway. In conclusion, this study underscores that unhealthy dietary factors, particularly those high in fructose and fat, may intensify the hazard of BL and adversely impact visual health. Full article

Ultraviolet B (UVB) irradiation drives skin photodamage, prompting exploration of natural therapeutics. This study investigated the reparative effects and mechanisms of crude Gastrodia elata polysaccharides (GP) on UVB-induced acute skin damage. GP was extracted from fresh G. elata via water extraction and alcohol precipitation. It is a homogeneous polysaccharide with a weight-average molecular weight of 808.863 kDa, comprising Ara, Glc, Fru, and GalA. Histopathological analysis revealed that topical application of GP on the dorsal skin of mice effectively restored normal physiological structure, suppressing epidermal hyperplasia and collagen degradation. Biochemical assays showed that GP significantly reduced the activities of MPO and MDA following UVB exposure while restoring the enzymatic activities of SOD and GSH, thereby mitigating oxidative stress. Moreover, GP treatment markedly upregulated the anti-inflammatory cytokines TGF-β and IL-10 and downregulated the pro-inflammatory mediators IL-6, IL-1β, and TNF-α, suggesting robust anti-inflammatory effects. Transcriptomics revealed dual-phase mechanisms: Early repair (day 5) involved GP-mediated suppression of hyper inflammation and accelerated necrotic tissue clearance via pathway network modulation. Late phase (day 18) featured enhanced anti-inflammatory, antioxidant, and tissue regeneration processes through energy-sufficient, low-inflammatory pathway networks. Through a synergistic response involving antioxidation, anti-inflammation, promotion of collagen synthesis, and acceleration of skin barrier repair, GP achieves comprehensive repair of UVB-induced acute skin damage. Our findings not only establish GP as a potent natural alternative to synthetic photoprotective agents but also reveal novel pathway network interactions governing polysaccharide-mediated skin regeneration. Full article

Background: Bambusaoldhamii is an important economic bamboo species. However, flowering occurred after its introduction and cultivation, resulting in damage to the economy of bamboo forests. Currently, the molecular mechanism of flowering induced by introduction stress is still unclear. This study systematically explored the key genes and regulatory pathways of flowering in Bambusaoldhamii under introduction stress through field experiments combined with transcriptome sequencing and weighted gene co-expression network analysis (WGCNA), with the aim of providing a basis for flower-resistant cultivation and molecular breeding of bamboo. Results: The study conducted transcriptome sequencing on flowering and non-flowering Bambusaoldhamii bamboo introduced from Youxi, Fujian Province for 2 years, constructed a reference transcriptome containing 213,747 Unigenes, and screened out 36,800–42,980 significantly differentially expressed genes (FDR < 0.05). The results indicated that the photosensitive gene CRY and the temperature response gene COR413-PM were significantly upregulated in the flowering group; the expression level of the heavy metal detoxification gene MT3 increased by 27.77 times, combined with the upregulation of the symbiotic signaling gene NIN. WGCNA analysis showed that the expression level of the flower meristem determination gene AP1/CAL/FUL in the flowering group was 90.38 times that of the control group. Moreover, its expression is regulated by the cascade synergy of CRY-HRE/RAP2-12-COR413-PM signals. Conclusions: This study clarifies for the first time that the stress of introducing Bambusaoldhamii species activates the triad pathways of photo-temperature signal perception (CRY/COR413-PM), heavy metal detoxification (MT3), and symbiotic regulation (NIN), collaboratively driving the AP1/CAL/FUL gene expression network and ultimately triggering the flowering process. Full article

Background: Integrating artificial intelligence into clinical photography offers great potential for monitoring skin conditions such as actinic keratosis (AK) and skin field cancerization. Identifying the extent of AK lesions often requires more than analyzing lesion morphology—it also depends on contextual cues, such as surrounding photodamage. This highlights the need for models that can combine fine-grained local features with a comprehensive global view. Methods: To address this challenge, we propose AKTransU-net, a hybrid U-net-based architecture. The model incorporates Transformer blocks to enrich feature representations, which are passed through ConvLSTM modules within the skip connections. This configuration allows the network to maintain semantic coherence and spatial continuity in AK detection. This global awareness is critical when applying the model to whole-image detection via tile-based processing, where continuity across tile boundaries is essential for accurate and reliable lesion segmentation. Results: The effectiveness of AKTransU-net was demonstrated through comparative evaluations with state-of-the-art segmentation models. A proprietary annotated dataset of 569 clinical photographs from 115 patients with actinic keratosis was used to train and evaluate the models. From each photograph, crops of 512 × 512 pixels were extracted using translation lesion boxes that encompassed lesions in different positions and captured different contexts. AKtransU-net exhibited a more robust context awareness and achieved a median Dice score of 65.13%, demonstrating significant progress in whole-image assessments. Conclusions: Transformer-driven context modeling offers a promising approach for robust AK lesion monitoring, supporting its application in real-world clinical settings where accurate, context-aware analysis is crucial for managing skin field cancerization. Full article

Andrographolide (AP), a bioactive compound from Andrographis paniculata, is known for its anti-inflammatory and antioxidant properties, both essential for wound healing. However, its effects on energy metabolism during tissue repair and its role in UVB-induced photoaging remain poorly understood. This study explored AP’s multitarget therapeutic effects on wound healing under photoaging conditions (PhA/WH) using network pharmacology and experimental validation. Scratch wound assays showed that AP promoted keratinocyte migration in UVB-exposed HaCaT cells. Bioinformatic analysis identified 10 key targets in PhA/WH, including TNF-α, IL-1β, JUN, PPARγ, MAPK3, TP53, TGFB1, HIF-1α, PTGS2, and CTNNB1. AP suppressed UVB-induced pro-inflammatory gene expression (IL-1β, IL-6, IL-8, and COX-2) and inhibited the phosphorylation of ERK1/2 and P38, while enhancing Hypoxia-Inducible Factor-1alpha (HIF-1α) and peroxisome proliferator-activated receptors (PPARγ) expression. GC/MS-based metabolomics revealed that AP reversed UVB-induced disruptions in fatty acid metabolism, glycolysis/gluconeogenesis, and tricarboxylic acid (TCA) cycle, indicating its role in restoring the metabolic balance necessary for tissue regeneration. In conclusion, andrographolide modulates key inflammatory and metabolic pathways involved in wound repair and photoaging. These mechanistic insights contribute to a better understanding of the molecular processes underlying skin regeneration under photodamage and may inform future therapeutic strategies. Full article

Ultraviolet B (UVB), a component of solar ultraviolet light, is a major contributor to skin photodamage. UVB exposure primarily affects the epidermis, which leads to wrinkle formation, loss of skin elasticity, oxidative stress, and inflammation. Prolonged or intense UVB exposure can increase the risk of skin cancer. Collagen peptides are known as functional foods that improve skin dryness and wound healing. In this study, we aimed to investigate the protective and ameliorative effects of a low-molecular-weight collagen peptide (LMWCP) with a high absorption rate and photodamage. In vitro analysis using human dermal fibroblasts (HDFs) demonstrated that LMWCP promoted skin protection by increasing procollagen type I production, enhancing cell proliferation and migration, and inhibiting MMP-1 activity. Furthermore, LMWCP intake was indicated by improved skin hydration, reduced trans-epidermal water loss (TEWL), and changes in the clinical parameters, including skin elasticity, erythema, and scaling scores in UVB-exposed hairless mice. In the UVB-damaged tissues, an increase in skin elasticity-related enzymes was observed along with a decrease in aging-related and pro-inflammatory gene expression. Histological analysis revealed an increase in collagen content and restoration of dermal thickness. These findings suggested that LMWCP has significant benefits in preventing and improving UVB-induced skin damage. Full article

Belle II is a particle physics experiment working at an high luminosity collider within a hard irradiation environment. The Time-Of-Propagation detector, aimed at the charged particle identification, surrounds the Belle II tracking detector on the barrel part. This detector is composed by 16 modules, each module contains a finely fused silica bar, coupled to microchannel plate photomultiplier tube (MCP-PMT) photo-detectors and readout by high-speed electronics. The MCP-PMT lifetime at the nominal collider luminosity is about one year, this is due to the high photon background degrading the quantum efficiency of the photocathode. An alternative to these MCP-PMTs is multi-pixel photon counters (MPPC), known as silicon photomultipliers (SiPM). The SiPMs, in comparison to MCP-PMTs, have a lower cost, higher photon detection efficiency and are unaffected by the presence of a magnetic field, but also have a higher dark count rate that rapidly increases with the integrated neutron flux. The dark count rate can be mitigated by annealing the damaged devices and/or operating them at low temperatures. We tested SiPMs, with different dimensions and pixel sizes from different producers, to study their time resolution (the main constraint that has to satisfy the photon detector) and to understand their behavior and tolerance to radiation. For these studies we irradiated the devices to radiation up to $5\times {10}^{11}1$ MeV neutrons equivalent (neq) per cm² fluences; we also started studying the effect of annealing on dark count rates. We performed several measurements on these devices, on top of the dark count rate, at different conditions in terms of overvoltage and temperatures. These measurements are: IV-curves, amplitude spectra, time resolution. For the last two measurements we illuminated the devices with a picosecond pulsed laser at very low intensities (with a number of detected photons up to about twenty). We present results mainly on two types of SiPMs. A new SiPM prototype developed in collaboration with FBK with the aim of improving radiation hardness, is expected to be delivered in September 2025. Full article

Hurricanes are major drivers of forest structure in the Caribbean. In 2017, Hurricane Maria caused substantial damage to Puerto Rico’s forests. We studied forest structure variation across 75 sites at Las Casas de la Selva, a sustainable forest plantation in Patillas, Puerto Rico, seven years after Hurricane Maria hit the property. At each site we analyzed 360° photos in a 3D VR headset to quantify the vertical structure and transformed them into hemispherical images to quantify canopy closure and ground cover. We also computed the Vertical Habitat Diversity Index (VHDI) from the amount of foliage in four strata: herbaceous, shrub, understory, and canopy. Using the Local Bivariate Relationship tool in ArcGIS Pro, we analyzed the relationship between forest recovery (vertical structure, canopy closure, and ground cover) and damage. Likewise, we analyzed the effects of elevation, slope, and aspect, on damage, canopy closure, and vertical forest structure. We found that canopy closure decreases with increasing elevation and increases with the amount of damage. Higher elevations show a greater amount of damage even seven years post hurricane. We conclude that trees in the mixed tabonuco/plantation forest are more susceptible to hurricanes at higher elevations. The results have implications for plantation forest management under climate-change-driven higher intensity hurricane regimes. Full article

The microalgal defense strategies for different white light intensities (70–700 μmol m⁻² s⁻¹) were investigated in isolates from unexplored habitats, focusing on photosynthetic performance. Chlorella sorokiniana strain F4 from a Mediterranean inland swamp and two strains related to Pectinodesmus pectinatus (PEC) and Ettlia pseudoalveolaris (ETI) from an Ecuadorian highland lake were exposed to light over 18 h. The results showed that PSII photochemical efficiency was affected with increasing light due to photoinhibition or photodamage. F4 showed a low threshold of saturation light intensity, after which NPQ was compromised and total antioxidant levels were increased, leading to a reduction in its PSII photochemistry performance. F4 exhibited limited capacity for antennae reorganization in response to light stress. ETI and PEC differed in their photophysiological responses, although they came from the same habitat. ETI maintained high Chlb to Chla (i.e., large antennae), exhibited sustained energy dissipation, and preserved a high antioxidant pool (i.e., mycosporine-like amino acids) in all lights. Differently, in PEC, NPQ, antennae rearrangement, and reactive oxygen species scavenger pool were induced in a light-dependent manner. This study revealed the complex relationship between light parameters and microalgal physiology affected by environmental constraint adaptation and phylogenetic diversity. Full article

Hair is continuously exposed to various damaging factors in daily life, necessitating effective protective strategies that balance efficacy with environmental sustainability. In this study, we developed an environmentally friendly hair protective coating using casein proteins crosslinked with tannic acid via riboflavin phosphate-mediated photo-initiation. Casein solutions containing tannic acid (0.05% w/v) and riboflavin phosphate (0.01–0.1% w/v) were prepared and applied to virgin Asian hair, followed by blue light irradiation to initiate crosslinking. The coating formation mechanism was investigated through rheological characterization, which confirmed successful network formation with optimal mechanical stability at a 0.05% tannic acid concentration. Chemical analysis using FTIR spectroscopy revealed subtle but meaningful interactions between the coating components, while SEM analysis demonstrated the coating’s integration with the hair surface. Mechanical property evaluations showed that the photo-crosslinked coating significantly enhanced hair tensile strength by approximately 21% compared to untreated hair, while maintaining appropriate elasticity. Region-specific analysis of stress–strain behavior indicated that the coating extended the initial Hookean region while preserving natural resistance in the post-yield region, creating a balanced enhancement in mechanical properties. This approach offers a promising alternative to conventional hair treatments by utilizing natural, food-grade components and mild processing conditions, addressing growing demands for sustainable hair care solutions that effectively protect against daily damage. Full article

A 71-year-old Caucasian woman presented with lesions on both elbows. A physical examination revealed arcuate plaques with raised erythematous edges and central clearing. Comedones and cysts were evident on the border of the lesions. The dermatoscopic view showed the presence of pores, in addition to granuloma annulare changes. The biopsies showed changes according to granuloma annulare, but the granulomas were closely related to comedones and cysts. Furthermore, the presence of elastophagocytosis via multinucleated Langhans-type giant cells was evident. Verhoeff–van Gieson staining highlighted the transepithelial elimination of elastic fibers in the bottom of some cysts. The presence of comedones or cysts is exceptional in granuloma annulare. Only four similar cases have been reported. Although all previous cases showed lesions in sun-exposed areas over photodamaged skin, only our case showed transepithelial elimination of elastic fibers. Diabetes mellitus (DM) could play a role in the pathogenesis of this variant of actinic granuloma annulare, because most cases are associated with uncontrolled DM and the lesions improve after DM is controlled. Full article

Melanoma, the most aggressive form of skin cancer, still represents a significant and growing public health concern. Ultraviolet radiation (UVR) is considered the primary driver of melanoma, although genetic predisposition also plays a critical role. This review explores the intricate molecular mechanisms by which UVR-induced photodamage contributes to melanoma development. We examine epidemiological evidence linking UV exposure to increased risk, detailing how UVR damage to DNA triggers inflammatory responses and impairs DNA repair mechanisms. Specifically, we discuss the roles of nucleotide excision repair (NER) and base excision repair (BER) in mitigating UV damage. The review further explores diagnostic and surgical implications for melanomas arising on sun-exposed skin. By synthesizing current evidence, this overview aims to deepen understanding of the complex relationship between UVR, photodamage, and melanoma, shedding light on the need for personalized preventive strategies to better stratify the risk and introduce behavioral changes to reduce skin photodamage. Full article