UV Radiation Resistance Research Articles

Structural insights into the main S-layer unit of Deinococcus radiodurans reveal a massive protein complex with porin-like features

In the extremophile bacterium Deinococcus radiodurans, the outermost surface layer is tightly connected with the rest of the cell wall. This integrated organization provides a compact structure that shields the bacterium against environmental stresses. The fundamental unit of this surface layer (S-layer) is the S-layer deinoxanthin-binding complex (SDBC), which binds the carotenoid deinoxanthin and provides both, thermostability and UV radiation resistance. However, the structural organization of the SDBC awaits elucidation. Here, we report the isolation of the SDBC with a gentle procedure consisting of lysozyme treatment and solubilization with the nonionic detergent n-dodecyl-β-d-maltoside, which preserved both hydrophilic and hydrophobic components of the SDBC and allows the retention of several minor subunits. As observed by low-resolution single-particle analysis, we show that the complex possesses a porin-like structural organization, but is larger than other known porins. We also noted that the main SDBC component, the protein DR_2577, shares regions of similarity with known porins. Moreover, results from electrophysiological assays with membrane-reconstituted SDBC disclosed that it is a nonselective channel that has some peculiar gating properties, but also exhibits behavior typically observed in pore-forming proteins, such as porins and ionic transporters. The functional properties of this system and its porin-like organization provide information critical for understanding ion permeability through the outer cell surface of S-layer-carrying bacterial species.

Improving durability of glass fiber reinforced polymer composites by incorporation of ZnO/OMMT nanoparticles subjected to UV radiation and hygrothermal aging

Glass fiber reinforced polymer (GFRP) composites have high sensitivity to UV radiation, temperature, and moisture, and these factors lead to the decrease of mechanical properties. This study attempts to modify unsaturated polyester (UP) and vinylester (VE) resins with nano zinc oxide (ZnO) and organo-montmorillonite (OMMT), in order to improve UV radiation resistance and hygrothermal resistance. The nano ZnO/OMMT modified UP and VE based GFRP composites were subjected to UV radiation and hygrothermal aging at 30 °C, 50 °C and 60 °C (95% RH) for 90 days. Mass loss, moisture uptake, color change, flexural properties and short-beam-shear test were investigated. In comparison to unmodified GFRP specimens, ZnO/OMMT modifying decreased the mass loss, the color change, saturation moisture uptake, and the coefficient of diffusion. After exposure in UV radiation for 90 days, the flexural strength and interlaminar shear strength of nano modified GFRP composites increased by 23.5% and 27.8% compared with those of the unmodified GFRP composites. Nano ZnO/OMMT modifying also increased the flexural strength and interlaminar shear strength by 26.5% and 27.2% in hygrothermal condition at 60 °C. Furthermore, based on the change of mechanical properties and Arrhenius rate model, a prediction model was proposed to predict the life of nano modified FRP composites.

Functional Division Between the RecA1 and RecA2 Proteins in Myxococcus xanthus

Myxococcus xanthus DK1622 has two RecA genes, recA1 (MXAN_1441) and recA2 (MXAN_1388), with unknown functional differentiation. Herein, we showed that both recA genes were induced by ultraviolet (UV) irradiation but that the induction of recA1 was more delayed than that of recA2. Deletion of recA1 did not affect the growth but significantly decreased the UV-radiation survival, homologous recombination (HR) ability, and induction of LexA-dependent SOS genes. In contrast, the deletion of recA2 markedly prolonged the lag phase of bacterial growth and increased the sensitivity to DNA damage caused by hydrogen peroxide but did not change the UV-radiation resistance or SOS gene inducibility. Protein activity analysis demonstrated that RecA1, but not RecA2, catalyzed DNA strand exchange (DSE) and LexA autocleavage in vitro. Transcriptomic analysis indicated that RecA2 has evolved mainly to regulate gene expression for cellular transportation and antioxidation. This is the first report of functional divergence of duplicated bacterial recA genes. The results highlight the evolutionary strategy of M. xanthus cells for DNA HR and genome sophistication.

How autophagy is tied to inflammation and cancer

ABSTRACTIt is not completely understood how autophagy is tied to inflammation and age-related cancer predisposition. Here, we used a mouse model with inducible expression of a cancer-derived frameshift mutation in UV radiation resistance associated (UVRAG) to demonstrate that intervention with autophagy suppressor could exacerbate inflammation and promote age-related spontaneous cancers.

Enhanced thermal stability, hydrophobicity, UV radiation resistance, and antibacterial properties of wool fabric treated with p-aminobenzenesulphonic acid.

Wool fibre is a popular fibre for the manufacture of apparel and floor coverings, but it does not have adequate thermal stability, antistatic, UV resistance, and antibacterial properties that are required for some applications, such as outerwear and hospital gowns. In this work, a wool fabric was treated with para-aminobenzenesulphonic acid (ABSA) by the oxidative polymerisation method and its effect on the thermal stability, UV radiation resistance, electrical conductivity and antibacterial properties of the treated fabric was systematically evaluated. It was found that the ABSA treatment had synergistic effects on the various functional properties of the treated fabric. The ABSA treatment not only made the fabric antibacterial but also enhanced its UV radiation absorption capability, surface hydrophobicity, electro-conductivity, tensile strength, and thermal stability. The maximum degradation temperature of the wool fibre increased from 339.5 °C to 349.6 °C and the UV-B transmission through the fabric at 290 nm reduced to 1.5%. The surface hydrophobicity of the treated fabric samples also improved as the surface contact angle of the fabric increased from 119.5° for the untreated to 131.7° for the fabric treated with 4% ABSA. The surface electrical resistance decreased from 1200 × 109 to 484 × 109 Ohm cm−1, and the treated fabric also showed excellent antibacterial activity against Staphylococcus aureus and Klebsiella pneumoniae. The developed treatment could be used in the textile industry as an energy-efficient process for the multi-functionalisation of wool and other polyamide fibres.

Computational search for UV radiation resistance strategies in Deinococcus swuensis isolated from Paramo ecosystems.

Ultraviolet radiation (UVR) is widely known as deleterious for many organisms since it can cause damage to biomolecules either directly or indirectly via the formation of reactive oxygen species. The goal of this study was to analyze the capacity of high-mountain Espeletia hartwegiana plant phyllosphere microorganisms to survive UVR and to identify genes related to resistance strategies. A strain of Deinococcus swuensis showed a high survival rate of up to 60% after UVR treatment at 800J/m2 and was used for differential expression analysis using RNA-seq after exposing cells to 400J/m2 of UVR (with >95% survival rate). Differentially expressed genes were identified using the R-Bioconductor package NOISeq and compared with other reported resistance strategies reported for this genus. Genes identified as being overexpressed included transcriptional regulators and genes involved in protection against damage by UVR. Non-coding (nc)RNAs were also differentially expressed, some of which have not been previously implicated. This study characterized the immediate radiation response of D. swuensis and indicates the involvement of ncRNAs in the adaptation to extreme environmental conditions.

Ubiquitination of UVRAG by SMURF1 promotes autophagosome maturation and inhibits hepatocellular carcinoma growth

ABSTRACTUVRAG (UV radiation resistance associated) is an important regulator of mammalian macroautophagy/autophagy by interacting with BECN1, PIK3C3, and RUBCN. Phosphorylation of UVRAG by MTORC1 negatively regulates autophagosome maturation under nutrient-enriched conditions. However, how UVRAG ubiquitination is regulated is still unknown. Here we report that UVRAG is ubiquitinated by SMURF1 at lysine residues 517 and 559, which decreases the association of UVRAG with RUBCN and promotes autophagosome maturation. However, the deubiquitinase ZRANB1 specifically cleaves SMURF1-induced K29 and K33-linked polyubiquitin chains from UVRAG, thereby increasing the binding of UVRAG to RUBCN and inhibiting autophagy flux. We also demonstrate that CSNK1A1-mediated UVRAG phosphorylation at Ser522 disrupts the binding of SMURF1 to UVRAG through PPxY motif and blocks UVRAG ubiquitination-mediated autophagosome maturation. Interestingly, ZRANB1 is phosphorylated at Thr35, and Ser209 residues by CSNK1A1, and this phosphorylation activates its deubiquitinating activity. Importantly, we provide in vitro and in vivo evidence that UVRAG ubiquitination at lysine residues 517 and 559 or prevention of Ser522 phosphorylation by D4476, a CSNK1A1 inhibitor, enhances the lysosomal degradation of EGFR, which significantly inhibits hepatocellular carcinoma (HCC) growth. Furthermore, UVRAG S522 phosphorylation levels correlate with ZRANB1 T35/S209 phosphorylation levels and poor prognosis in HCC patients. These findings identify a novel molecular mechanism by which ubiquitination and phosphorylation of UVRAG regulate its function in autophagosome maturation and HCC growth, encouraging further study of their potential therapeutic implications.Abbreviations: ATG: autophagy related; BafA1: bafilomycin A1; BECN1: beclin 1; CHX: cycloheximide; CSNK1A1/CK1α: casein kinase 1 alpha 1; CQ: chloroquine; DUB: deubiquitinase; EBSS: Earle’s balanced salt solution; EGF: epidermal growth factor; GFP: green fluorescent protein; GST: glutathione S-transferase; HBSS: Hanks balanced salts solution; HCC: hepatocellular carcinoma; MAP1LC3B/LC3: microtubule associated protein 1 light chain 3 beta; MEFs: mouse embryo fibroblasts; mRFP: monomeric red fluorescent protein; PIK3C3/VPS34: phosphatidylinositol 3-kinase catalytic subunit type 3; PTMs: post-translational modifications; RUBCN: rubicon autophagy regulator; siRNA: small interfering RNA; SMURF1: SMAD specific E3 ubiquitin protein ligase 1; SQSTM1: sequestosome 1; Ub-AMC: ubiquitin-7-amido-4-methylcoumarin: a fluorogenic substrate; UVRAG: UV radiation resistance associated; ZRANB1/TRABID: zinc finger RANBP2-type containing 1

Macrophages target Salmonella by Lc3-associated phagocytosis in a systemic infection model

ABSTRACTInnate immune defense against intracellular pathogens, like Salmonella, relies heavily on the autophagy machinery of the host. This response is studied intensively in epithelial cells, the target of Salmonella during gastrointestinal infections. However, little is known of the role that autophagy plays in macrophages, the predominant carriers of this pathogen during systemic disease. Here we utilize a zebrafish embryo model to study the interaction of S. enterica serovar Typhimurium with the macroautophagy/autophagy machinery of macrophages in vivo. We show that phagocytosis of live but not heat-killed Salmonella triggers recruitment of the autophagy marker GFP-Lc3 in a variety of patterns labeling tight or spacious bacteria-containing compartments, also revealed by electron microscopy. Neutrophils display similar GFP-Lc3 associations, but genetic modulation of the neutrophil/macrophage balance and ablation experiments show that macrophages are critical for the defense response. Deficiency of atg5 reduces GFP-Lc3 recruitment and impairs host resistance, in contrast to atg13 deficiency, indicating that Lc3-Salmonella association at this stage is independent of the autophagy preinitiation complex and that macrophages target Salmonella by Lc3-associated phagocytosis (LAP). In agreement, GFP-Lc3 recruitment and host resistance are impaired by deficiency of Rubcn/Rubicon, known as a negative regulator of canonical autophagy and an inducer of LAP. We also found strict dependency on NADPH oxidase, another essential factor for LAP. Both Rubcn and NADPH oxidase are required to activate a Salmonella biosensor for reactive oxygen species inside infected macrophages. These results identify LAP as the major host protective autophagy-related pathway responsible for macrophage defense against Salmonella during systemic infection.Abbreviations: ATG: autophagy related gene; BECN1: Beclin 1; CFU: colony forming units; CYBA/P22PHOX: cytochrome b-245, alpha chain; CYBB/NOX2: cytochrome b-245 beta chain; dpf: days post fertilization; EGFP: enhanced green fluorescent protein; GFP: green fluorescent protein; hfp: hours post fertilization; hpi: hours post infection; IRF8: interferon regulatory factor 8; Lcp1/L-plastin: lymphocyte cytosolic protein 1; LAP: LC3-associated phagocytosis; MAP1LC3/LC3: microtubule-associated protein 1A/1B-light chain 3; mCherry: red fluorescent protein; mpeg1: macrophage expressed gene 1; mpx: myeloid specific peroxidase; NADPH oxidase: nicotinamide adenine dinucleotide phosphate oxidase; NCF4/P40PHOX: neutrophil cytosolic factor 4; NTR-mCherry: nitroreductase-mCherry fusion; PTU: phenylthiourea; PtdIns3K: class III phosphatidylinositol 3-kinase; PtdIns3P: phosphatidylinositol 3-phosphate; RB1CC1/FIP200: RB-1 inducible coiled coin 1; ROS: reactive oxygen species; RT-PCR: reverse transcriptase polymerase chain reaction; RUBCN/RUBICON: RUN and cysteine rich domain containing BECN1-interacting protein; SCV: Salmonella-containing vacuole; S. Typhimurium/S.T: Salmonella enterica serovar Typhimurium; TEM: transmission electron microscopy; Tg: transgenic; TSA: tyramide signal amplification; ULK1/2: unc-51-like autophagy activating kinase 1/2; UVRAG: UVRAG: UV radiation resistance associated; wt: wild type

Research on the UV radiation resistance of DNA improved by mechanical stimulation to cell nucleus Making Research Paper

Research on the UV radiation resistance of DNA improved by mechanical stimulation to cell nucleus Making Research Paper

Multifunctional Flax Fibres Based on the Combined Effect of Silver and Zinc Oxide (Ag/ZnO) Nanostructures.

Cellulosic fibre-based smart materials exhibiting multiple capabilities are getting tremendous attention due to their wide application areas. In this work, multifunctional flax fabrics with piezoresistive response were developed through the combined functionalization with silver (Ag) and zinc oxide (ZnO) nanoparticles (NPs). Biodegradable polyethylene glycol (PEG) was used to produce AgNPs, whereas ZnONPs were synthetized via a simple and low-cost method. Flax fabrics with and without NPs were characterized by Ground State Diffuse Reflectance (GSDR), Field Emission Scanning Electron Microscopy (FESEM), Energy Dispersive Spectroscopy (EDS), X-ray Diffraction (XRD), Attenuated Total Reflectance-Fourier Transform Infrared Spectroscopy (ATR-FTIR), and Thermogravimetric analysis (TGA). After creating a conductive surface by flax functionalization with AgNPs, ZnONPs were synthetized onto these fabrics. The developed fibrous systems exhibited piezoresistive response and the sensor sensitivity increased with the use of higher ZnO precursor concentrations (0.4 M). Functionalized fabrics exhibited excellent antibacterial activity against Gram-negative (Escherichia coli) and Gram-positive (Staphylococcus aureus) bacteria, higher hydrophobicity (WCA changed from 00 to >1000), UV radiation resistance, and wash durability. Overall, this work provides new insights regarding the bifunctionalization of flax fabrics with Ag/ZnO nanostructures and brings new findings about the combined effect of both NPs for the development of piezoresistive textile sensors with multifunctional properties.

Crosstalk between Autophagy and Nanomaterials: Internalization, Activation, Termination.

Nanomaterials (NMs) are comprehensively applied in biomedicine due to their unique physical and chemical properties. Autophagy, as an evolutionarily conserved cellular quality control process, is closely associated with the effect of NMs on cells. In this review, the recent advances in NM-induced/inhibited autophagy (NM-phagy) are summarized, with an aim to present a comprehensive description of the mechanisms of NM-phagy from the perspective of internalization, activation, and termination, thereby bridging autophagy and nanomaterials. Several possible mechanisms are extensively reviewed including the endocytosis pathway of NMs and the related cross components (clathrin and adaptor protein 2 (AP-2), adenosine diphosphate (ADP)-ribosylation factor 6 (Arf6), Rab, UV radiation resistance associated gene (UVRAG)), three main stress mechanisms (oxidative stress, damaged organelles stress, and toxicity stress), and several signal pathway-related molecules. The mechanistic insight is beneficial to understand the autophagic response to NMs or NMs' regulation of autophagy. The challenges currently encountered and research trend in the field of NM-phagy are also highlighted. It is hoped that the NM-phagy discussion in this review with the focus on the mechanistic aspects may serve as a guideline for future research in this field.

Photo-graft modification of fluoropolymer surface and its bonding properties with EVA hot melt adhesive

<p indent=0mm>As an important part of photovoltaic (PV) modules, backsheet materials play an important role in protecting solar cell from environmental degradation caused by moisture penetration. Fluoropolymers, which have excellent weatherability, UV radiation resistance and chemical stability, are widely used as the outer layer of the backsheet to ensure the long-term reliability and safety of PV modules. However, the low surface energy and poor adhesion to other materials of fluoropolymer markedly limits its practical application in encapsulation of solar cells which require the backsheet to be firmly bonded with PV modules by ethylene-vinyl acetate copolymer (EVA) hot melt adhesive. Although some methods such as corona discharge, plasma treatment, radiation grafting can effectively improve the surface properties of fluoropolymers, UV-induced graft polymerization is still considered as one of the most promising approach due to its advantages in fast reaction rate, low cost of processing, simple equipment, easy industrialization, and no damage to bulk property of materials. In this paper, different copolymers of acrylic acid-butyl acrylate (PAA-BA) or butyl acrylate-trimethylolpropane triacrylate (PBA-TMPTA) were introduced onto fluoropolymer film by photografting polymerization. The effects of UV irradiation time, monomer composition and monomer concentration on the graft efficiency were investigated. The chemical composition, surface morphology and chemical composition of the film were characterized by attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS) and contact angle analysis (CA). The results showed that the UV-induced graft polymerization can be successfully performed on the fluoropolymer film and a dense graft layer could be introduced on the surface. The introduction of PAA-BA changed the surface property of fluoropolymer film and facilitated the spreading of EVA, while the adhesive strength of PAA-BA modified surface bonded with EVA film is only <sc>0.8–4.8 N/cm,</sc> which is almost same as the unmodified fluoropolymer film. Similarly, introducing functional groups such as hydroxyl and sulfate groups by confined photooxidation method did not improve the adhesion properties. When PBA-TMPTA copolymer was grafted on the fluoropolymer film, its laminate with EVA hot melt adhesive had a peeling strength up to <sc>17.6 N/cm</sc> (15 times of unmodified film). The remarkable increase in the adhesive property of modified fluoropolymer was believed to be attributed to the unreacted double bond of grafted PBA-TMPTA. During the melt of EVA, the peroxide additive in it decomposed to release radicals and resulted in the crosslinking of EVA film. Meanwhile, the chain radicals of EVA also reacted with double bond in the PBA-TMPTA layer, which could form covalent bond between the interfaces and improve the adhesive strength. Therefore, the improvement of interfacial adhesion performance is mainly due to chemical bond rather than physical interaction.

ULK1 phosphorylates Ser30 of BECN1 in association with ATG14 to stimulate autophagy induction

ABSTRACTULK1 (unc51-like autophagy activating kinase 1) is a serine/threonine kinase that plays a key role in regulating macroautophagy/autophagy induction in response to amino acid starvation. Despite the recent progress in understanding ULK1 functions, the molecular mechanism by which ULK1 regulates the induction of autophagy remains elusive. In this study, we determined that ULK1 phosphorylates Ser30 of BECN1 (Beclin 1) in association with ATG14 (autophagy-related 14) but not with UVRAG (UV radiation resistance associated). The Ser30 phosphorylation was induced by deprivation of amino acids or treatments with Torin 1 or rapamycin, the conditions that inhibit MTORC1 (mechanistic target of rapamycin complex 1), and requires ATG13 and RB1CC1 (RB1 inducible coiled-coil 1), proteins that interact with ULK1. Hypoxia or glutamine deprivation, which inhibit MTORC1, was also able to increase the phosphorylation in a manner dependent upon ULK1 and ULK2. Blocking the BECN1 phosphorylation by replacing Ser30 with alanine suppressed the amino acid starvation-induced activation of the ATG14-containing PIK3C3/VPS34 (phosphatidylinositol 3-kinase catalytic subunit type 3) kinase, and reduced autophagy flux and the formation of phagophores and autophagosomes. The Ser30-to-Ala mutation did not affect the ULK1-mediated phosphorylations of BECN1 Ser15 or ATG14 Ser29, indicating that the BECN1 Ser30 phosphorylation might regulate autophagy independently of those 2 sites. Taken together, these results demonstrate that BECN1 Ser30 is a ULK1 target site whose phosphorylation activates the ATG14-containing PIK3C3 complex and stimulates autophagosome formation in response to amino acid starvation, hypoxia, and MTORC1 inhibition.

MiR-125b is downregulated in systemic lupus erythematosus patients and inhibits autophagy by targeting UVRAG

Systemic lupus erythematosus (SLE) is a severe autoimmune disease and the pathogenesis remains incompletely understood. This study aimed to investigate the role of miR-125b in the pathogenesis of SLE and explore the underlying mechanism. Compared to healthy controls, the expression of miR-125b decreased in peripheral blood mononuclear cells (PBMCs) of SLE patients. In addition, PBMCs exposed to ultraviolet B had lower miR-125b level compared to those unexposed to radiation. We identified UV radiation resistance associated gene (UVRAG) as a target of miR-125b. Jurkat cells treated with miR-125b-5p agomir showed reduced levels of ATG7, Beclin-1 and LC3 II and decreased autophagy. In contrast, Jurkat cells treated with miR-125b-5p antagomir showed increased levels of ATG7, Beclin-1 and LC3 II and increased autophagy. Furthermore, Jurkat cells transfected with UVRAG expression vector showed higher expression of ATG7, Beclin-1 and LC3 II and increased autophagy. Conversely, cells transfected with UVRAG siRNA had lower expression of ATG7, Beclin-1 and LC3 II and decreased autophagy. Taken together, our data demonstrate that Ultraviolet B radiation can downregulate miR-125b-5p and increase UVRAG expression and autophagy activity in PBMCs of SLE patients. These findings help explain how ultraviolet B exacerbates SLE and suggest that UVRAG is a potential therapeutic target for SLE.

Synthesis and characterization of organosoluble radiation‐resistant composite materials from octa(maleimidophenyl)silsesquioxane and aryldiamines

Radiation‐resistant composite materials based on nano‐sized polyhedral oligomeric silsesquioxanes building blocks. We successfully synthesized via aspartimide linkages resulting from Michael addition of octa(maleimidophenyl)silsesquioxane (OMIPS) and aryldiamines OMIPS. These materials can serve as a nano building block for construction of materials with nanometer control of the periodicity of the organic and inorganic components. The monomer concentration and reaction time of polymerization are optimized, which were 0.047 mol L−1 and 96 hours, respectively. The resulting polyaspartimides (PPAIs) were characterized by Fourier transform infrared, dielectric analysis, thermal properties, and morphological studies. The PPAI polymers are amorphous and soluble in highly polar organic solvents and show glass transition temperatures of 297°C to 323°C. They offer good thermal stability of 437°C to 507°C under nitrogen atmosphere, high char yields of 58% to 65% at 800°C, and have a dielectric constant of 3.7 to 4.1. Transition electron microscope analysis reveals the OMIPS dispersed well in molecular level in the continuous matrix while some aggregates also seen in the matrix. The UV radiation resistance of the resulting PPAI polymers was investigated.

Light scattering on PHA granules protects bacterial cells against the harmful effects of UV radiation.

Numerous prokaryotes accumulate polyhydroxyalkanoates (PHA) in the form of intracellular granules. The primary function of PHA is the storage of carbon and energy. Nevertheless, there are numerous reports that the presence of PHA granules in microbial cells enhances their stress resistance and fitness when exposed to various stress factors. In this work, we studied the protective mechanism of PHA granules against UV irradiation employing Cupriavidus necator as a model bacterial strain. The PHA-accumulating wild type strain showed substantially higher UV radiation resistance than the PHA non-accumulating mutant. Furthermore, the differences in UV-Vis radiation interactions with both cell types were studied using various spectroscopic approaches (turbidimetry, absorption spectroscopy, and nephelometry). Our results clearly demonstrate that intracellular PHA granules efficiently scatter UV radiation, which provides a substantial UV-protective effect for bacterial cells and, moreover, decreases the intracellular level of reactive oxygen species in UV-challenged cells. The protective properties of the PHA granules are enhanced by the fact that granules specifically bind to DNA, which in turn provides shield-like protection of DNA as the most UV-sensitive molecule. To conclude, the UV-protective action of PHA granules adds considerable value to their primary storage function, which can be beneficial in numerous environments.

Борорганические олигомеры в качестве УФ-стабилизаторов стеклопластиков

The results of researches UV radiation resistance of fiberglass, modified by additives of polymethylenester of phenols and boric acid, pigment and stabilizers based on benzophenone, benzotriazole, and sebacate are represented in article. The changes in tensile strength of the fiberglass modified samples from the accelerated of aging time in weathering tester are shows.

Experimental study on the effects of mechanical stimuli on cellular UV radiation resistance of DNA

Experimental study on the effects of mechanical stimuli on cellular UV radiation resistance of DNA

Experimental study on the mechanism of cyclic stretch-induced cellular UV radiation resistance

Experimental study on the mechanism of cyclic stretch-induced cellular UV radiation resistance

Effects Of Oral Glutamine on Inflammatory and Autophagy Responses in Cancer Patients Treated With Abdominal Radiotherapy: A Pilot Randomized Trial.

Background and Aims: Abdominal radiotherapy (RT) causes harm to the mid gastrointestinal mucosa by release of pro-inflammatory cytokines and promotes autophagic changes in tumor cells. This study was aimed to measure the effect of glutamine administration on markers of inflammation and autophagy in cancer patients treated with RT.Methods: In this double-blind, randomized, controlled pilot trial 43 patients under abdominal RT diagnosed of pelvic or abdominal malignancies receiving glutamine (30 g/d) or placebo (casein, 30 g/d). Patient recruitment took place in the Complejo Asistencial Universitario of León (CAULE), Spain. Patient evaluation took place at three different time points during the study: before RT (pre-treatment), in the middle of the RT period (mid-treatment), and after finishing RT (post-treatment). Data were compared by analysis of variance and the Newmann Keuls test. Significance was accepted at p < 0.05.Results Abdominal RT increased whole blood mRNA levels of inflammatory and autophagic markers, but glutamine administration showed significantly lower expression of toll-like receptor 4 (TLR4), CD36, interleukin-1β (IL-1β), tumor necrosis factor-alpha (TNF-α), cyclooxygenase-2 (COX-2), and matrix metalloproteinase-9 (MMP-9). Moreover, glutamine reduced the expression of the transcription factors nuclear factor kappa B (NF-κB) and activator protein 1 (AP-1). Glutamine also inhibited the autophagic response, with changes in expression of beclin-1, UV radiation resistance associated gene (UVRAG), autophagy-related protein-5 (Atg5), protein 1 light chain 3 (LC3), sequestosome 1 (p62/SQSTM1) and lysosome-associated membrane protein (LAMP)-1.Conclusions Findings provide evidence that glutamine decreases the inflammatory response and abolishes the changes of the autophagy machinery in patients receiving abdominal RT. The protective effect of glutamine must continue being investigated to disclose further molecular pathways.