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Frontiers in Plant Science 2024, an aerial green alga, exhibits remarkable adaptability to the extreme conditions of Antarctica by forming layered colonies capable of utilizing far-red light for...
, an aerial green alga, exhibits remarkable adaptability to the extreme conditions of Antarctica by forming layered colonies capable of utilizing far-red light for photosynthesis. Despite a recent report on the structure of 's unique light-harvesting chlorophyll (Chl)-binding protein complex (Pc-frLHC), which facilitates far-red light absorption and uphill excitation energy transfer to photosystem II, the specific genes encoding the subunits of Pc-frLHC have not yet been identified. Here, we report a draft genome sequence of strain 4113, originally isolated from soil samples on Ongul Island, Antarctica. We obtained a 92 Mbp sequence distributed in 1,045 scaffolds comprising 10,244 genes, reflecting 87.1% of the core eukaryotic gene set. Notably, 26 genes associated with the light-harvesting Chl / binding complex (LHC) were identified, including four Pc-frLHC genes, with similarity to a noncanonical Lhca gene with four transmembrane helices, such as Ot_Lhca6 in and Cr_LHCA2 in . A comparative analysis revealed that Pc-frLHC shares homology with certain Lhca genes found in and species. This similarity indicates that Pc-frLHC has evolved from an ancestral Lhca gene with four transmembrane helices and branched out within the Trebouxiaceae family. Furthermore, RNA-seq analysis conducted during the initiation of Pc-frLHC gene induction under red light illumination indicated that Pc-frLHC genes were induced independently from other genes associated with photosystems or LHCs. Instead, the genes of transcription factors, helicases, chaperones, heat shock proteins, and components of blue light receptors were identified to coexpress with Pc-frLHC. Those kinds of information could provide insights into the expression mechanisms of Pc-frLHC and its evolutional development.
PubMed: 38916036
DOI: 10.3389/fpls.2024.1409116 -
Phytomedicine : International Journal... Mar 2024Photodamage to the skin stands out as one of the most widespread epidermal challenges globally. Prolonged exposure to sunlight containing ultraviolet radiation (UVR)... (Review)
Review
BACKGROUND
Photodamage to the skin stands out as one of the most widespread epidermal challenges globally. Prolonged exposure to sunlight containing ultraviolet radiation (UVR) instigates stress, thereby compromising the skin's functionality and culminating in photoaging. Recent investigations have shed light on the importance of autophagy in shielding the skin from photodamage. Despite the acknowledgment of numerous phytochemicals possessing photoprotective attributes, their potential to induce autophagy remains relatively unexplored.
PURPOSE
Diminished autophagy activity in photoaged skin underscores the potential benefits of restoring autophagy through natural compounds to enhance photoprotection. Consequently, this study aims to highlight the role of natural compounds in safeguarding against photodamage and to assess their potential to induce autophagy via an in-silico approach.
METHODS
A thorough search of the literature was done using several databases, including PUBMED, Science Direct, and Google Scholar, to gather relevant studies. Several keywords such as Phytochemical, Photoprotection, mTOR, Ultraviolet Radiation, Reactive oxygen species, Photoaging, and Autophagy were utilized to ensure thorough exploration. To assess the autophagy potential of phytochemicals through virtual screening, computational methodologies such as molecular docking were employed, utilizing tools like AutoDock Vina. Receptor preparation for docking was facilitated using MGLTools.
RESULTS
The initiation of structural and functional deterioration in the skin due to ultraviolet radiation (UVR) or sunlight-induced reactive oxygen species/reactive nitrogen species (ROS/RNS) involves the modulation of various pathways. Natural compounds like phenolics, flavonoids, flavones, and anthocyanins, among others, possess chromophores capable of absorbing light, thereby offering photoprotection by modulating these pathways. In our molecular docking study, these phytochemicals have shown binding affinity with mTOR, a negative regulator of autophagy, indicating their potential as autophagy modulators.
CONCLUSION
This integrated review underscores the photoprotective characteristics of natural compounds, while the in-silico analysis reveals their potential to modulate autophagy, which could significantly contribute to their anti-photoaging properties. The findings of this study hold promise for the advancement of cosmeceuticals and therapeutics containing natural compounds aimed at addressing photoaging and various skin-related diseases. By leveraging their dual benefits of photoprotection and autophagy modulation, these natural compounds offer a multifaceted approach to combatting skin aging and related conditions.
PubMed: 38901286
DOI: 10.1016/j.phymed.2024.155508 -
Photochemistry and Photobiology Jun 2024Exposure to phototoxicants and photosensitizers can result in the generation of reactive oxygen species (ROS), leading to oxidative stress, DNA damage, and various...
Exposure to phototoxicants and photosensitizers can result in the generation of reactive oxygen species (ROS), leading to oxidative stress, DNA damage, and various skin-related issues such as aging, allergies, and cancer. While several photo-protectants offer defense against ultraviolet radiation (UV-R), their effectiveness is often limited by photo-instability. Sunset Yellow (SY), an FDA-approved food dye, possesses significant UV-R and visible light absorption properties. However, its photoprotective potential has remained unexplored. Our investigation reveals that SY exhibits remarkable photostability for up to 8 h under both UV-R and sunlight. Notably, SY demonstrates the ability to quench ROS, including singlet oxygen (O), superoxide radicals ( ), and hydroxyl radicals (·OH) induced by rose bengal, riboflavin and levofloxacin, respectively. Moreover, SY proves effective in protecting against the apoptotic and necrotic cell death induced by the phototoxicant chlorpromazine (CPZ) in HaCaT cells. Further, it was observed that SY imparts photoprotection by inhibiting intracellular ROS generation and calcium release. Genotoxicity evaluation provides additional evidence supporting SY's photoprotective effects against CPZ-induced DNA damage. In conclusion, these findings underscore the potential of SY as a promising photoprotective agent against the toxic hazards induced by phototoxicants, suggesting its prospective application in the formulation of broad-spectrum sunscreens.
PubMed: 38899585
DOI: 10.1111/php.13966 -
ACS Medicinal Chemistry Letters Jun 2024A hydrophobic nitric oxide (NO) photodonor integrating both nitroso and nitro functionalities within its chromophoric skeleton has been synthesized. Excitation of this...
A hydrophobic nitric oxide (NO) photodonor integrating both nitroso and nitro functionalities within its chromophoric skeleton has been synthesized. Excitation of this compound with blue light triggers the release of two NO molecules from the nitroso and the nitro functionalities via a stepwise mechanism. Encapsulation of the NO photodonor within biocompatible neutral, cationic, and anionic β-cyclodextrin branched polymers as suitable carriers leads to supramolecular nanoassemblies, which exhibit the same nature of the photochemical processes but NO photorelease performances enhanced by about 1 order of magnitude when compared with the free guest. Antibacterial tests carried out with methicillin-resistant and demonstrate an effective antibacterial activity exclusively under light activation and point out a differentiated role of the polymeric nanocarriers in determining the outcome of the antibacterial photodynamic action.
PubMed: 38894929
DOI: 10.1021/acsmedchemlett.4c00061 -
Structural basis for an early stage of the photosystem II repair cycle in Chlamydomonas reinhardtii.Nature Communications Jun 2024Photosystem II (PSII) catalyzes water oxidation and plastoquinone reduction by utilizing light energy. It is highly susceptible to photodamage under high-light...
Photosystem II (PSII) catalyzes water oxidation and plastoquinone reduction by utilizing light energy. It is highly susceptible to photodamage under high-light conditions and the damaged PSII needs to be restored through a process known as the PSII repair cycle. The detailed molecular mechanism underlying the PSII repair process remains mostly elusive. Here, we report biochemical and structural features of a PSII-repair intermediate complex, likely arrested at an early stage of the PSII repair process in the green alga Chlamydomonas reinhardtii. The complex contains three protein factors associated with a damaged PSII core, namely Thylakoid Enriched Factor 14 (TEF14), Photosystem II Repair Factor 1 (PRF1), and Photosystem II Repair Factor 2 (PRF2). TEF14, PRF1 and PRF2 may facilitate the release of the manganese-stabilizing protein PsbO, disassembly of peripheral light-harvesting complexes from PSII and blockage of the Q site, respectively. Moreover, an α-tocopherol quinone molecule is located adjacent to the heme group of cytochrome b, potentially fulfilling a photoprotective role by preventing the generation of reactive oxygen species.
Topics: Photosystem II Protein Complex; Chlamydomonas reinhardtii; Thylakoids; Light-Harvesting Protein Complexes; Plant Proteins; Cytochrome b Group; Oxidation-Reduction; Reactive Oxygen Species; Light
PubMed: 38890314
DOI: 10.1038/s41467-024-49532-2 -
Clinical and Experimental Dermatology Jun 2024
PubMed: 38876092
DOI: 10.1093/ced/llae230 -
EClinicalMedicine Jul 2024Janus kinase (JAK) inhibition is a promising approach for treating vitiligo. We aimed to assess the efficacy and safety of upadacitinib, an oral selective JAK inhibitor,...
Once-daily upadacitinib versus placebo in adults with extensive non-segmental vitiligo: a phase 2, multicentre, randomised, double-blind, placebo-controlled, dose-ranging study.
BACKGROUND
Janus kinase (JAK) inhibition is a promising approach for treating vitiligo. We aimed to assess the efficacy and safety of upadacitinib, an oral selective JAK inhibitor, in adults with non-segmental vitiligo.
METHODS
This was a phase 2, multicentre, randomised, double-blind, placebo-controlled, dose-ranging study completed at 33 clinical centres in the United States, Canada, France, and Japan. Eligible patients were aged 18-65 years with non-segmental vitiligo and had a Facial Vitiligo Area Scoring Index (F-VASI) ≥0.5 and a Total Vitiligo Area Scoring Index (T-VASI) ≥5. Patients were randomly assigned (2:2:2:1:1) using an interactive response technology to receive upadacitinib 6 mg (UPA6), upadacitinib 11 mg (UPA11), upadacitinib 22 mg (UPA22), or placebo (PBO; preassigned to switch to either UPA11 or UPA22 in period 2) once daily for 24 weeks (period 1). For weeks 24-52 (period 2), patients randomly assigned to upadacitinib continued their treatment, and patients receiving PBO switched to their preassigned upadacitinib dose in a blinded fashion. The primary endpoint was the percent change from baseline in F-VASI at week 24. Efficacy was analysed in the intention-to-treat population, and safety was examined in all randomly assigned patients who received at least one dose of study drug. This study is registered with ClinicalTrials.gov, number NCT04927975.
FINDINGS
Between June 16, 2021, and June 27, 2022, 185 patients (including 115 [62%] who were female and 70 [38%] who were male) were randomly assigned to UPA6 (n = 49), UPA11 (n = 47), UPA22 (n = 43), or PBO (n = 46). At week 24, the LS mean difference versus PBO in the percent change from baseline in F-VASI was -7.60 (95% CI -22.18 to 6.97; p = 0.3037) for UPA6, -21.27 (95% CI -36.02 to -6.52; p = 0.0051) for UPA11, and -19.60 (95% CI -35.04 to -4.16; p = 0.0132) for UPA22. The LS mean difference versus PBO in the percent change from baseline in T-VASI was -7.45 (95% CI -16.86 to 1.96; p = 0.1198) for UPA6, -10.84 (95% CI -20.37 to -1.32; p = 0.0259) for UPA11 and -14.27 (95% CI -24.24 to -4.30; p = 0.0053) for UPA22. Ongoing treatment with upadacitinib induced continuous skin repigmentation over time without reaching a plateau through week 52. The rates for study drug discontinuation and serious treatment-emergent adverse events (TEAEs) were higher in the UPA22 group than in the UPA11 and UPA6 groups. Eight serious TEAEs, including one death of unknown cause and one case of infiltrating lobular breast carcinoma, were reported through 52 weeks; only two serious TEAEs (coronary artery arteriosclerosis [UPA6 (n = 1)] and non-fatal ischemic stroke [UPA11 (n = 1)]) were deemed by the investigator to have a reasonable possibility of being related to study drug. The one case of breast cancer in the UPA11 group was deemed unrelated to study drug, and the one death of unknown cause in the UPA22 group was reviewed and adjudicated and was deemed to be unrelated to study drug. The most common TEAEs were COVID-19, headache, acne, and fatigue. No new safety signals were observed.
INTERPRETATION
Upadacitinib monotherapy led to substantial repigmentation of both facial and total body vitiligo lesions and may offer an effective treatment option for adults with extensive non-segmental vitiligo. Based on these findings, upadacitinib 15 mg is being investigated in adults and adolescents with non-segmental vitiligo in an ongoing phase 3 randomised controlled trial.
FUNDING
AbbVie Inc.
PubMed: 38873632
DOI: 10.1016/j.eclinm.2024.102655 -
Annual Review of Microbiology Jun 2024Widespread phytochrome photoreceptors use photoisomerization of linear tetrapyrrole (bilin) chromophores to measure the ratio of red to far-red light. Cyanobacteria also... (Review)
Review
Widespread phytochrome photoreceptors use photoisomerization of linear tetrapyrrole (bilin) chromophores to measure the ratio of red to far-red light. Cyanobacteria also contain distantly related cyanobacteriochrome (CBCR) proteins that share the bilin-binding GAF domain of phytochromes but sense other colors of light. CBCR photocycles are extremely diverse, ranging from the near-UV to the near-IR. Photoisomerization of the bilin triggers photoconversion of the CBCR input, thereby modulating the biochemical signaling state of output domains such as histidine kinase bidomains that can interface with cellular signal transduction pathways. CBCRs thus can regulate several aspects of cyanobacterial photobiology, including phototaxis, metabolism of cyclic nucleotide second messengers, and optimization of the cyanobacterial light-harvesting apparatus. This review examines spectral tuning, photoconversion, and photobiology of CBCRs and recent developments in understanding their evolution and in applying them in synthetic biology.
PubMed: 38848579
DOI: 10.1146/annurev-micro-041522-094613 -
Photochemistry and Photobiology Jun 2024The field of sun protection is quickly changing and the research article by Douki et al., published in the current issue of Photochemistry and Photobiology, reported...
An important step towards the comprehensive sun protection: Blue-light exposure inhibits DNA repair in reconstituted human skin and a broadband sunscreen avoids this inhibition.
The field of sun protection is quickly changing and the research article by Douki et al., published in the current issue of Photochemistry and Photobiology, reported key experimental data that will certainly help the development of better sun care products. Mutagenic photoproducts (CPDs, cyclobutane pyrimidine dimers and 6-4PPs, pyrimidine-6-4-pyrimidone photoproducts) were formed in the reconstructed human epidermis (RHE) by UVB (312 nm) irradiation, and their concentrations were detected by HPLC-MS/MS as a function of time after the UVB treatment. RHE had been previously exposed or not (control) to blue light (427 nm). Both CPDs and 6-4PPs were shown to last longer in blue-light irradiated RHE, proving the inhibition of the DNA repair by blue light exposure. This is a highly relevant information because sunscreens allow people to enjoy longer periods under the sun and consequently, to endure very high doses of blue light. The work also reported results obtained with RHEs previously treated with a sunscreen formulation containing a broadband filter that offers blue-light protection. Interestingly, authors observed that the DNA repair was not significantly inhibited in RHE previously treated with the sunscreen offering broadband protection. Readers will find a scientifically sound proof of the importance of blue-light protection in sun care products.
PubMed: 38828502
DOI: 10.1111/php.13979 -
Ophthalmology Science 2024To investigate the changes in axial length (AL) elongation and other ocular parameters before and during the coronavirus disease 2019 pandemic.
PURPOSE
To investigate the changes in axial length (AL) elongation and other ocular parameters before and during the coronavirus disease 2019 pandemic.
DESIGN
A longitudinal school-based study.
PARTICIPANTS
Public elementary schoolchildren in Tokyo (grades 1-6; age, 6-12 years) participated in this study from 2018 to 2021.
METHODS
All participants underwent eye examinations and provided written consent to measurements of the noncycloplegic refraction and ocular biometry including AL, among others. The students' parents also completed a questionnaire about the students' lifestyles. We included the right eye in our analysis and compared the changes in the ocular parameters among the periods using a linear mixed-effects model for repeated measures and examined the univariate and step-wise multiple regression analyses to evaluate the associations between myopia and other covariates.
MAIN OUTCOME MEASURES
Changes in AL elongation and other ocular parameters from 2018 to 2019 (prepandemic), that of 2019 to 2020 (immediately after the pandemic onset), and that of 2020 to 2021 (during the pandemic).
RESULTS
A total of 578 students before the pandemic period, 432 immediately after the pandemic onset, and 457 during the pandemic period were evaluated. The changes in the ALs and spherical equivalents (SEs) a year before, immediately after onset, and during the pandemic were 0.31 mm/-0.20 diopter, 0.38 mm/-0.27 diopter, and 0.28 mm/-0.47 diopter, respectively (ALs, < 0.001; SEs, = 0.014). The results of the questionnaire showed that time spent outdoors daily had changed during the 3 years to 79, 63, and 77 minutes/day, respectively ( < 0.001). Time spent using smartphones or tablets increased year by year to 41, 52, and 62 minutes/day ( < 0.001). The greatest AL elongation occurred during the period when the shortest amount of time was spent outdoors during the 3 years.
CONCLUSIONS
These results suggested that the school closures and decreasing time spent outdoors might have caused greater AL elongation among schoolchildren in Tokyo; however, it is possible that, although the time spent in near work still increased, the return to the time spent outdoors to the prepandemic levels may have affected the slowing of AL elongation after lockdown.
FINANCIAL DISCLOSURES
Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.
PubMed: 38827490
DOI: 10.1016/j.xops.2024.100491