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Journal of Drugs in Dermatology : JDD May 2024This study aimed to investigate the ultraviolet (UV) protection/repair benefits of a patented Amino Acid Complex (AAComplex).
OBJECTIVE
This study aimed to investigate the ultraviolet (UV) protection/repair benefits of a patented Amino Acid Complex (AAComplex).
METHODS
I) AAComplex was incubated with dermal fibroblasts, with/without UVA, and collagen I was measured with a GlasBoxPlus device. II) A lotion, with/without AAComplex (1%) was applied topically to skin explants, following UVA irradiation, and quantified for health-related biomarkers (TNFalpha, histamine, and MMP-1). III) A broad spectrum sunscreen with SPF 46 and a skincare serum containing AAComplex (2%) were assessed using epidermal equivalents, in the presence of UV irradiation, for effects on IL-1alpha, thymine dimers, Ki-67, filaggrin and Nrf2.
RESULTS
I) Collagen I synthesis in dermal fibroblasts was significantly decreased after UVA compared to without UV. The presence of AAComplex prevented this decrease. II) UVA irradiation of skin explants increased histamine, TNFα, and MMP-1. Hydrocortisone aceponate cream significantly decreases all 3 biomarkers. AAComplex contained lotion also significantly decreased all 3 biomarkers, the no AAComplex control lotion only reduced histamine. III) With the regimen of sunscreen + AAComplex contained skincare serum, the significant reduction in IL-1alpha was observed along with a complete recovery of Ki-67 and stimulation of filaggrin and Nrf2T. No thymine dimer positive cell was observed indicating the most positive skin impact from the regiment. Conclusion: This research using different human skin models demonstrated that AAComplex can provide protection and damage repair caused by UV, at the ingredient level also when formulated in a serum or lotion formula. Skin may be best protected from UV damage when the regimen is used. J Drugs Dermatol. 2024;23(5):366-375. doi:10.36849/JDD.7916.
Topics: Humans; Filaggrin Proteins; Ultraviolet Rays; Fibroblasts; Matrix Metalloproteinase 1; Tumor Necrosis Factor-alpha; Skin; Sunscreening Agents; Amino Acids; Interleukin-1alpha; Histamine; Skin Cream; Biomarkers; Collagen Type I; Intermediate Filament Proteins; Ki-67 Antigen; Pyrimidine Dimers; Cells, Cultured; NF-E2-Related Factor 2
PubMed: 38709706
DOI: 10.36849/JDD.7916 -
Immunity Apr 2024Toll-like receptor 7 (TLR7) is essential for recognition of RNA viruses and initiation of antiviral immunity. TLR7 contains two ligand-binding pockets that recognize...
Toll-like receptor 7 (TLR7) is essential for recognition of RNA viruses and initiation of antiviral immunity. TLR7 contains two ligand-binding pockets that recognize different RNA degradation products: pocket 1 recognizes guanosine, while pocket 2 coordinates pyrimidine-rich RNA fragments. We found that the endonuclease RNase T2, along with 5' exonucleases PLD3 and PLD4, collaboratively generate the ligands for TLR7. Specifically, RNase T2 generated guanosine 2',3'-cyclic monophosphate-terminated RNA fragments. PLD exonuclease activity further released the terminal 2',3'-cyclic guanosine monophosphate (2',3'-cGMP) to engage pocket 1 and was also needed to generate RNA fragments for pocket 2. Loss-of-function studies in cell lines and primary cells confirmed the critical requirement for PLD activity. Biochemical and structural studies showed that PLD enzymes form homodimers with two ligand-binding sites important for activity. Previously identified disease-associated PLD mutants failed to form stable dimers. Together, our data provide a mechanistic basis for the detection of RNA fragments by TLR7.
PubMed: 38697119
DOI: 10.1016/j.immuni.2024.04.010 -
Physical Chemistry Chemical Physics :... May 2024The photoinduced cycloreversion of oxetane derivatives is of considerable biological interest since these compounds are involved in the photochemical formation and...
The photoinduced cycloreversion of oxetane derivatives is of considerable biological interest since these compounds are involved in the photochemical formation and repair of the highly mutagenic pyrimidine (6-4) pyrimidone DNA photoproducts ((6-4)PPs). Previous reports have dealt with the photoreactivity of heterodimeric oxetanes composed mainly of benzophenone (BP) and thymine (Thy) or uracil (Ura) derivatives. However, these models are far from the non-isolable Thy〈º〉Thy dimers, which are the real precursors of (6-4)PPs. Thus, we have synthesized two chemically stable homodimeric oxetanes through the Paternò-Büchi reaction between two identical enone units, 1,4-benzoquinone (BQ) and 1,4-naphthoquinone (NQ), that led to formation of BQ-Ox and NQ-Ox, respectively. Their photoreactivity has been studied by means of steady-state photolysis and transient absorption spectroscopy from the femtosecond to the microsecond time scale. Thus, photolysis of BQ-Ox and NQ-Ox led to formation of the monomeric BQ or NQ, respectively, through ring opening in a "non-adiabatic" process. Accordingly, the transient absorption spectra of the triplet excited quinones (BQ* and NQ*) were not observed as a result of direct photolysis of the quinone-derived oxetanes. In the case of NQ-Ox, a minor signal corresponding to NQ* was detected; its formation was ascribed to minor photodegradation of the oxetane during acquisitions of the spectra during the laser experiments. These results are supported by computational analyses based on density functional theory and multiconfigurational quantum chemistry (CASSCF/CASPT2); here, an accessible conical intersection between the ground and excited singlet states has been characterized as the main structure leading to deactivation of excited BQ-Ox or NQ-Ox. This behavior contrasts with those previously observed for heterodimeric thymine-derived oxetanes, where a certain degree of ring opening into the excited triplet state is observed.
PubMed: 38651219
DOI: 10.1039/d4cp00830h -
Experimental Eye Research Jun 2024Xeroderma pigmentosum (XP) is a rare genetic disorder characterized by injury to the ocular surface due to exposure to ultraviolet (UV) radiation. UV-induced damage in...
Xeroderma pigmentosum (XP) is a rare genetic disorder characterized by injury to the ocular surface due to exposure to ultraviolet (UV) radiation. UV-induced damage in the cells leads to the formation of cyclobutane pyrimidine dimers (CPDs) and 6-4 pyrimidine-pyrimidone photoproducts that are repaired by the NER (Nucleotide Excision Repair) pathway. Mutations in the genes coding for NER proteins, as reported in XP patients, would lead to sub-optimal damage repair resulting in clinical signs varying from photo-keratitis to cancerous lesions on the ocular surface. Here, we aimed to provide evidence for the accumulation of DNA damage and activation of DNA repair pathway proteins in the corneal cells of patients with XP. Corneal buttons of patients who underwent penetrating keratoplasty were stained to quantify DNA damage and the presence of activated DNA damage response proteins (DDR) using specific antibodies. Positive staining for pH2A.X and thymidine dimers confirmed the presence of DNA damage in the corneal cells. Positive cells were found in both control corneas and XP samples however, unlike normal tissues, positive cells were found in all cell layers of XP samples indicating that these cells were sensitive to very low levels of UV. pH2A.X-positive cells were significantly more in XP corneas (p < 0.05) indicating the presence of double strand breaks in these tissues. A positive expression of phosphorylated-forms of DDR proteins was noted in XP corneas (unlike controls) such as ataxia telangiectasia mutated/Rad-3 related proteins (ATM/ATR), breast cancer-1 and checkpoint kinases-1 and -2. Nuclear localization of XPA was noted in XP samples which co-localized (calculated using Pearson's correlation) with pATM (0.9 ± 0.007) and pATR (0.6 ± 0.053). The increased presence of these in the nucleus confirms that unresolved DNA damage was accumulating in these cells thereby leading to prolonged activation of the damage response proteins. An increase in pp53 and TUNEL positive cells in the XP corneas indicated cell death likely driven by the p53 pathway. For comparison, cultured normal corneal epithelial cells were exposed to UV-radiation and stained for DDR proteins at 3, 6 and 24 h after irradiation to quantify the time taken by cells with intact DDR pathway to repair damage. These cells, when exposed to UV showed nuclear translocation of DDR proteins at 3 and 6 h which reduced significantly by 24 h confirming that the damaged DNA was being actively repaired leading to cell survival. The persistent presence of the DDR proteins in XP corneas indicates that damage is being actively recognized and DNA replication is stalled, thereby causing accumulation of damaged DNA leading to cell death, which would explain the cancer incidence and cell loss reported in these patients.
Topics: Humans; Ultraviolet Rays; DNA Damage; Xeroderma Pigmentosum; DNA Repair; Pyrimidine Dimers; Keratoplasty, Penetrating; Cornea; Female; Adult; Histones; Male; Middle Aged; Ataxia Telangiectasia Mutated Proteins; Adolescent; Young Adult
PubMed: 38641197
DOI: 10.1016/j.exer.2024.109901 -
Dermatology (Basel, Switzerland) 2024Ultraviolet radiation (UVR) is the primary risk factor for keratinocyte carcinomas. Oral supplementation with nicotinamide (NAM) is reported to reduce the formation of... (Comparative Study)
Comparative Study
INTRODUCTION
Ultraviolet radiation (UVR) is the primary risk factor for keratinocyte carcinomas. Oral supplementation with nicotinamide (NAM) is reported to reduce the formation of new keratinocyte carcinomas. NAM's photoprotection is mediated by enhanced DNA repair. We wanted to explore whether NAM in combination with antiproliferative (metformin [Met]) or antioxidant (phloroglucinol [PG]) compounds could potentially enhance its photoprotective effects.
METHODS
Hairless mice (C3.Cg-Hrhr/TifBomTac) were treated orally with either a standard dose of NAM monotherapy (NAM-mono; 600 mg/kg) or NAM (400 mg/kg) combined with Met (200 mg/kg) (NAM-Met) or PG (75 mg/kg) (NAM-PG). Mice were irradiated with 3.5 standard erythema doses of UVR three times per week to induce tumour development. Photoprotective effects were based on (i) tumour onset of the first three tumours, (ii) skin photodamage, and (iii) DNA damage (cyclobutane pyrimidine dimers [CPDs] and pyrimidine-pyrimidone (6-4) photoproducts [6-4PPs]).
RESULTS
All mice treated with NAM demonstrated a delay in tumour onset and reduced tumour burden compared to the UV control group (NAM, NAM-Met, NAM-PG vs. UV control: p ≤ 0.015). NAM-mono and NAM-PG increased time until all three tumours with no difference between them, indicating a similar degree of photoprotection. NAM-mono had no effect on DNA damage compared to the UV control group (p > 0.05), whereas NAM-PG reduced 6-4PP lesions (p < 0.01) but not CPDs (p > 0.05) compared to NAM-mono. NAM-Met delayed the onset of the third tumour compared to the UV control but demonstrated a quicker onset compared to NAM-mono, suggesting inferior photoprotection compared to nicotinamide monotherapy.
CONCLUSION
NAM-PG was as effective in delaying UVR-induced tumour onset as NAM-mono. The reduction in 6-4PP lesions may indicate that the mechanism of NAM-PG is better suited for photoprotection than NAM-mono. NAM-mono was superior to NAM-Met, indicating a dose dependency of NAM's photoprotection. These results highlight the potential for combining photoprotective compounds to enhance photoprotection.
Topics: Animals; Niacinamide; Skin Neoplasms; Ultraviolet Rays; Mice, Hairless; Mice; Metformin; Neoplasms, Radiation-Induced; Drug Therapy, Combination; Antioxidants; DNA Damage; Female; Vitamin B Complex
PubMed: 38599196
DOI: 10.1159/000538445 -
Photochemical & Photobiological... May 2024Exposure to ultraviolet radiation (UVR) leads to skin DNA damage, specifically in the form of cyclobutane pyrimidine dimers, with thymidine dimers being the most common....
Exposure to ultraviolet radiation (UVR) leads to skin DNA damage, specifically in the form of cyclobutane pyrimidine dimers, with thymidine dimers being the most common. Quantifying these dimers can indicate the extent of DNA damage resulting from UVR exposure. Here, a new liquid chromatography-mass spectrometry (LC-MS) method was used to quantify thymidine dimers in the urine after a temporary increase in real-life UVR exposure. Healthy Danish volunteers (n = 27) experienced increased UVR exposure during a winter vacation. Individual exposure, assessed via personally worn electronic UVR dosimeters, revealed a mean exposure level of 32.9 standard erythema doses (SEDs) during the last week of vacation. Morning urine thymidine dimer concentrations were markedly elevated both 1 and 2 days post-vacation, and individual thymidine dimer levels correlated with UVR exposure during the last week of the vacation. The strongest correlation with erythema-weighted personal UVR exposure (Power model, r = 0.64, p < 0.001) was observed when both morning urine samples were combined to measure 48-h thymidine dimer excretion, whereas 24-h excretion based on a single sample provided a weaker correlation (Power model, r = 0.55, p < 0.001). Sex, age, and skin phototype had no significant effect on these correlations. For the first time, urinary thymidine dimer excretion was quantified by LC-MS to evaluate the effect of a temporary increase in personal UVR exposure in a real-life setting. The high sensitivity to elevated UVR exposure and correlation between urinary excretion and measured SED suggest that this approach may be used to quantify DNA damage and repair and to evaluate photoprevention strategies.
Topics: Humans; Ultraviolet Rays; Pyrimidine Dimers; Male; Adult; Female; DNA Damage; Middle Aged; Mass Spectrometry; Chromatography, Liquid; Young Adult; Radiation Exposure; Healthy Volunteers
PubMed: 38589652
DOI: 10.1007/s43630-024-00563-0 -
Scientific Reports Apr 2024Mutations in PINK1 and Parkin cause early-onset Parkinson's Disease (PD). PINK1 is a kinase which functions as a mitochondrial damage sensor and initiates mitochondrial...
Mutations in PINK1 and Parkin cause early-onset Parkinson's Disease (PD). PINK1 is a kinase which functions as a mitochondrial damage sensor and initiates mitochondrial quality control by accumulating on the damaged organelle. There, it phosphorylates ubiquitin, which in turn recruits and activates Parkin, an E3 ubiquitin ligase. Ubiquitylation of mitochondrial proteins leads to the autophagic degradation of the damaged organelle. Pharmacological modulation of PINK1 constitutes an appealing avenue to study its physiological function and develop therapeutics. In this study, we used a thermal shift assay with insect PINK1 to identify small molecules that inhibit ATP hydrolysis and ubiquitin phosphorylation. PRT062607, an SYK inhibitor, is the most potent inhibitor in our screen and inhibits both insect and human PINK1, with an IC in the 0.5-3 µM range in HeLa cells and dopaminergic neurons. The crystal structures of insect PINK1 bound to PRT062607 or CYC116 reveal how the compounds interact with the ATP-binding pocket. PRT062607 notably engages with the catalytic aspartate and causes a destabilization of insert-2 at the autophosphorylation dimer interface. While PRT062607 is not selective for PINK1, it provides a scaffold for the development of more selective and potent inhibitors of PINK1 that could be used as chemical probes.
Topics: Humans; Protein Kinases; HeLa Cells; Ubiquitin-Protein Ligases; Phosphorylation; Ubiquitin; Adenosine Triphosphate; Cyclohexylamines; Pyrimidines
PubMed: 38565869
DOI: 10.1038/s41598-024-58285-3 -
Current Issues in Molecular Biology Feb 2024Ultraviolet (UV) radiation plays a crucial role in the development of melanoma and non-melanoma skin cancers. The types of UV radiation are differentiated by wavelength:... (Review)
Review
Ultraviolet (UV) radiation plays a crucial role in the development of melanoma and non-melanoma skin cancers. The types of UV radiation are differentiated by wavelength: UVA (315 to 400 nm), UVB (280 to 320 nm), and UVC (100 to 280 nm). UV radiation can cause direct DNA damage in the forms of cyclobutane pyrimidine dimers (CPDs) and 6-4 photoproducts (6-4PPs). In addition, UV radiation can also cause DNA damage indirectly through photosensitization reactions caused by reactive oxygen species (ROS), which manifest as 8-hydroxy-2'-deoxyguanine (8-OHdG). Both direct and indirect DNA damage can lead to mutations in genes that promote the development of skin cancers. The development of melanoma is largely influenced by the signaling of the melanocortin one receptor (MC1R), which plays an essential role in the synthesis of melanin in the skin. UV-induced mutations in the BRAF and NRAS genes are also significant risk factors in melanoma development. UV radiation plays a significant role in basal cell carcinoma (BCC) development by causing mutations in the Hedgehog (Hh) pathway, which dysregulates cell proliferation and survival. UV radiation can also induce the development of squamous cell carcinoma via mutations in the TP53 gene and upregulation of MMPs in the stroma layer of the skin.
PubMed: 38534742
DOI: 10.3390/cimb46030126 -
A recombinant fungal photolyase autonomously enters human cell nuclei to fix UV-induced DNA lesions.Biotechnology Letters Jun 2024Solar ultraviolet radiations induced DNA damages in human skin cells with cyclobutane pyrimidine dimers (CPD) and (6-4) photoproducts (6-4PPs) as the most frequent...
Solar ultraviolet radiations induced DNA damages in human skin cells with cyclobutane pyrimidine dimers (CPD) and (6-4) photoproducts (6-4PPs) as the most frequent lesions. CPDs are repaired much slower than 6-4PPs by the nucleotide excision repair pathway, which are thus the major lesions that interfere with key cellular processes and give rise to gene mutations, possibly resulting in skin cancer. In prokaryotes and multicellular eukaryotes other than placental mammals, CPDs can be rapidly repaired by CPD photolyases in one simple enzymatic reaction using the energy of blue light. In this study, we aim to construct recombinant CPD photolyases that can autonomously enter human cell nuclei to fix UV-induced CPDs. A fly cell penetration peptide and a viral nucleus localization signal peptide were recombined with a fungal CPD photolyase to construct a recombinant protein. This engineered CPD photolyase autonomously crosses cytoplasm and nuclear membrane of human cell nuclei, which then efficiently photo-repairs UV-induced CPD lesions in the genomic DNA. This further protects the cells by increasing SOD activity, and decreasing cellular ROSs, malondialdehyde and apoptosis.
Topics: Humans; Deoxyribodipyrimidine Photo-Lyase; Ultraviolet Rays; Cell Nucleus; DNA Damage; DNA Repair; Recombinant Proteins; Pyrimidine Dimers; Fungal Proteins
PubMed: 38523200
DOI: 10.1007/s10529-024-03474-3 -
Heliyon Mar 2024The sensitivity of crops to ultraviolet B (UVB, 280-315 nm) radiation varies significantly. Plants' sensitivity to UVB is heavily influenced by the activity of the... (Review)
Review
The sensitivity of crops to ultraviolet B (UVB, 280-315 nm) radiation varies significantly. Plants' sensitivity to UVB is heavily influenced by the activity of the enzyme cyclobutane pyrimidine dimer (CPD) photolyase, which fixes UVB-induced CPDs. Crops grown in tropical areas with high level of UVB radiation, like from Africa and ssp. rice from Bengal, are more sensitive to UVB radiation and could suffer more as a result of rising UVB levels on the earth's surface. Therefore, creating crops that can withstand high UVB is crucial in tropical regions. There is, however, little information on current techniques for breeding UVB-resistant plants. The most recent techniques for producing UVB-resistant crops are presented in this review. The use of DNA methylation, boosting the antioxidant system, regulating the expression of micro-RNA396, and overexpressing CPD photolyase in transgenic plants are some of the methods that are discussed. CPD photolyase overexpression in transgenic plants is the most popular technique for producing UVB-resistant rice. The study also offers several strategies for creating UVB-resistant plants using gene editing techniques. To feed the world's rapidly expanding population, researchers can use the information from this study to improve food production.
PubMed: 38509919
DOI: 10.1016/j.heliyon.2024.e27806