Infection-specific phosphorylation of glutamyl-prolyl tRNA synthetase induces antiviral immunity.

The mammalian cytoplasmic multi-tRNA synthetase complex (MSC) is a depot system that regulates non-translational cellular functions. Here we found that the MSC component glutamyl-prolyl-tRNA synthetase (EPRS) switched its function following viral infection and exhibited potent antiviral activity. Infection-specific phosphorylation of EPRS at Ser990 induced its dissociation from the MSC, after which it was guided to the antiviral signaling pathway, where it interacted with PCBP2, a negative regulator of mitochondrial antiviral signaling protein (MAVS) that is critical for antiviral immunity. This interaction blocked PCBP2-mediated ubiquitination of MAVS and ultimately suppressed viral replication. EPRS-haploid (Eprs+/-) mice showed enhanced viremia and inflammation and delayed viral clearance. This stimulus-inducible activation of MAVS by EPRS suggests an unexpected role for the MSC as a regulator of immune responses to viral infection.

Hypoxia stabilizes SETDB1 to maintain genome stability.

Von Hippel-Lindau (VHL) is a tumor suppressor that functions as the substrate recognition subunit of the CRL2VHL E3 complex. While substrates of VHL have been identified, its tumor suppressive role remains to be fully understood. For further determination of VHL substrates, we analyzed the physical interactome of VHL and identified the histone H3K9 methyltransferase SETBD1 as a novel target. SETDB1 undergoes oxygen-dependent hydroxylation by prolyl hydroxylase domain proteins and the CRL2VHL complex recognizes hydroxylated SETDB1 for ubiquitin-mediated degradation. Under hypoxic conditions, SETDB1 accumulates by escaping CRL2VHL activity. Loss of SETDB1 in hypoxia compared with that in normoxia escalates the production of transposable element-derived double-stranded RNAs, thereby hyperactivating the immune-inflammatory response. In addition, strong derepression of TEs in hypoxic cells lacking SETDB1 triggers DNA damage-induced death. Our collective results support a molecular mechanism of oxygen-dependent SETDB1 degradation by the CRL2VHL E3 complex and reveal a role of SETDB1 in genome stability under hypoxia.

Cyclin Y regulates spatial learning and memory flexibility through distinct control of the actin pathway.

Spatial learning and memory flexibility are known to require long-term potentiation (LTP) and long-term depression (LTD), respectively, on a cellular basis. We previously showed that cyclin Y (CCNY), a synapse-remodeling cyclin, is a novel actin-binding protein and an inhibitory regulator of functional and structural LTP in vitro. In this study, we report that Ccny knockout (KO) mice exhibit enhanced LTP and weak LTD at Schaffer collateral-CA1 synapses in the hippocampus. In accordance with enhanced LTP, Ccny KO mice showed improved spatial learning and memory. However, although previous studies reported that normal LTD is necessary for memory flexibility, Ccny KO mice intriguingly showed improved memory flexibility, suggesting that weak LTD could exert memory flexibility when combined with enhanced LTP. At the molecular level, CCNY modulated spatial learning and memory flexibility by distinctively affecting the cofilin-actin signaling pathway in the hippocampus. Specifically, CCNY inhibited cofilin activation by original learning, but reversed such inhibition by reversal learning. Furthermore, viral-mediated overexpression of a phosphomimetic cofilin-S3E in hippocampal CA1 regions enhanced LTP, weakened LTD, and improved spatial learning and memory flexibility, thus mirroring the phenotype of Ccny KO mice. In contrast, the overexpression of a non-phosphorylatable cofilin-S3A in hippocampal CA1 regions of Ccny KO mice reversed the synaptic plasticity, spatial learning, and memory flexibility phenotypes observed in Ccny KO mice. Altogether, our findings demonstrate that LTP and LTD cooperatively regulate memory flexibility. Moreover, CCNY suppresses LTP while facilitating LTD in the hippocampus and negatively regulates spatial learning and memory flexibility through the control of cofilin-actin signaling, proposing CCNY as a learning regulator modulating both memorizing and forgetting processes.

Unraveling the mechanisms of benzo[a]pyrene degradation by Pigmentiphaga kullae strain KIT-003 using a multi-omics approach.

Polycyclic aromatic hydrocarbons (PAHs), notably benzo[a]pyrene (BaP), are environmental contaminants with multiple adverse ecological implications. Numerous studies have suggested the use of BaP biodegradation using various bacterial strains to remove BaP from the environment. This study investigates the BaP biodegradation capability of Pigmentiphaga kullae strain KIT-003, isolated from the Nak-dong River (South Korea) under specific environmental conditions. The optimum conditions of biodegradation were found to be pH 7.0, 35°C, and a salinity of 0 %. GC-MS analysis suggested alternative pathways by which KIT-003 produced catechol from BaP through several intermediate metabolites, including 4-formylchrysene-5-carboxylic acid, 5,6-dihydro-5,6-dihydroxychrysene-5-carboxylic acid (isomer: 3,4-dihydro-3,4-dihydroxychrysene-4-carboxylic acid), naphthalene-1,2-dicarboxylic acid, and 2-hydroxy-1-naphthoic acid. Proteomic profiles indicated upregulation of enzymes associated with aromatic compound degradation, such as nahAc and nahB, and of those integral to the tricarboxylic acid cycle, reflecting the strain's adaptability to and degradation of BaP. Lipidomic analysis of KIT-003 demonstrated that BaP exposure induced an accumulation of glycerolipids such as diacylglycerol and triacylglycerol, indicating their crucial role in bacterial adaptation mechanisms under BaP stress. This study provides significant scientific knowledge regarding the intricate mechanisms involved in BaP degradation by microorganisms.

Bacteria-derived metabolite, methylglyoxal, modulates the longevity of C. elegans through TORC2/SGK-1/DAF-16 signaling.

Gut microbes play diverse roles in modulating host fitness, including longevity; however, the molecular mechanisms underlying their mediation of longevity remain poorly understood. We performed genome-wide screens using 3,792 Escherichia coli mutants and identified 44 E. coli mutants that modulated Caenorhabditis elegans longevity. Three of these mutants modulated C. elegans longevity via the bacterial metabolite methylglyoxal (MG). Importantly, we found that low MG-producing E. coli mutants, Δhns E. coli, extended the lifespan of C. elegans through activation of the DAF-16/FOXO family transcription factor and the mitochondrial unfolded protein response (UPRmt). Interestingly, the lifespan modulation by Δhns did not require insulin/insulin-like growth factor 1 signaling (IIS) but did require TORC2/SGK-1 signaling. Transcriptome analysis revealed that Δhns E. coli activated novel class 3 DAF-16 target genes that were distinct from those regulated by IIS. Taken together, our data suggest that bacteria-derived MG modulates host longevity through regulation of the host signaling pathways rather than through nonspecific damage on biomolecules known as advanced glycation end products. Finally, we demonstrate that MG enhances the phosphorylation of hSGK1 and accelerates cellular senescence in human dermal fibroblasts, suggesting the conserved role of MG in controlling longevity across species. Together, our studies demonstrate that bacteria-derived MG is a novel therapeutic target for aging and aging-associated pathophysiology.

In vivo evaluation of novel particle-free polycaprolactone fillers for safety, degradation, and neocollagenesis in a rat model.

Dermal fillers have become popular due to the increased demand for skin rejuvenation products. Polycaprolactone (PCL), a newly developed bioresorbable medical polymer, has emerged as a durable and safe dermal filler. However, available PCL fillers cause irritation; carrier gels can coagulate PCL particles, block the injection needle, and cause nonhomogeneity of particle suspensions that could be responsible for the observed side effects. To relieve pain, premixing PCL filler with lidocaine. However, this formulation changes the property of the CMC portion of the PCL filler, and possibly results in an uneven suspension of the PCL particles. Hence, a particle-free PCL homogeneously solubilized in water was developed to overcome these limitations. This study aimed to assess the in vivo safety, biodegradability, and neocollagenesis ability of a novel PCL filler, DLMR01 using a rat model. Fillers were characterized after injecting a vehicle control or DLMR01 using a digital camera, folliscope, and a three-dimensional profiling system. Biopsy was performed to evaluate biocompatibility and neocollagenesis. Skin elasticity was measured using a Cutometer. DLMR01 caused no needle occlusion by particle aggregation or laborious injectability. Filler nodules dispersed to surrounding tissues within 6 hours without further granuloma formation. Histological inspection revealed no tissue residual material or foreign body reaction during the 12-week test period. DLMR01 increased dermal thickness, collagen regeneration, and skin elasticity. In conclusion, this study demonstrates the potential of DLMR01 for dermal rejuvenation in a rat model.

Preclinical evaluation for removal of bulging lower eyelid fat using ultrasound-assisted lipolysis on a Yorkshire pig.

PURPOSE: The purpose of this study is to evaluate the efficacy and safety of treating lower eyelid fat bulging with ultrasound-assisted lipolysis (UAL) by performing a preclinical evaluation of the procedure on a Yorkshire pig. METHODS: Two white Yorkshire pigs had lower eyelid fat bulging treated with UAL using a probe with a diameter of 1.0 mm or less. Fourteen days after treatment, we evaluated the changes in fat thickness from ultrasound, changes in skin contour (volume and height) from the Antera 3D™, and the disruption of fat cells and changes in collagen synthesis from histological evaluation. RESULTS: Fourteen days after treatment, the fat layer was significantly reduced with no damage to the skin surface. The mean change in the subcutaneous fat layer thickness was decreased 1.51-0.75 mm in ultrasound analysis. The skin contour of the treated area also decreased with time from 202.5 to 163.5 mm in mean volume and 0.8111 to 0.646 mm in mean height. Masson's trichrome staining showed that the UAL treatment induced the regeneration and remodeling of collagen. CONCLUSION: The results of this study demonstrate that UAL successfully reduced the bulging lower eyelid fat of a Yorkshire pig and also increased collagen contraction to tighten skin. UAL may be a beneficial and well-tolerated treatment option for lower eyelid fat bulging.

Comparison of different energy response for lipolysis using a 1,060-nm laser: An animal study of three pigs.

BACKGROUND: Non-invasive body-sculpting procedures are becoming increasingly popular. The application of 1,060 nm of laser energy transcutaneously to hyperthermically induce the disruption of fat cells in the abdomen is a type of non-invasive procedure. AIMS: The purpose of this study was to compare the treatment results from two parameters of the same system, each with different energy output levels, in an in vivo porcine model to determine the most effective application. METHODS: Female pigs (n = 3) were used in this study. We examined the effects of the treatment using photography, ultrasonography, gross and microscopic pathology, and histological examination in order to determine the mechanism of action, efficacy, and safety of the procedure. Blood chemistry analysis was performed before each session to check lipid levels and to monitor for any adverse changes in markers that may indicate liver damage. Biopsies were taken and routinely processed with hematoxylin and eosin and Oil Red O stains to examine for tissue damage at baseline and after each treatment. Terminal deoxynucleotidyl transferase deoxyuridine triphosphate nick end labeling (TUNEL) assays were performed to check for apoptotic-related DNA damage. RESULTS: Ultrasonic imaging of the same area before and after the application of 1,060 nm of laser energy at outputs of 0.9 and 1.4 W/cm2 showed that the density of the fat layer changed immediately after irradiation due to the transient heat transfer in the fat layer. Preclinical evaluation was performed to obtain comparison data on the safety and efficacy of subcutaneous fat reduction after applying the different energy outputs of 0.9 and 1.4 W/cm2 . CONCLUSION: Based on our findings, we suggest that long-term histologic changes through the use of these devices suggest a comparative effectiveness of the treatment energy.

Evaluation of nail surface topography using a three-dimensional in vivo optical skin imaging system.

BACKGROUND: The analysis of nail surface topography is a subject of ever-increasing interest in dermatology, especially in cosmetic studies. However, there is no accurate and scientifically sound instrumental method that can identify and provide quantitative data on nail surface topography. MATERIALS AND METHODS: The right index fingers of 78 healthy individuals were examined. The severity of nail roughness was rated by two independent dermatologists on a scale of 1 to 3. Using the phaseshift rapid in vivo measurement of the skin (PRIMOS) system, three-dimensional microtopography was performed, and the roughness parameter values were calculated and evaluated. The relationship between clinical nail roughness grade and nail roughness parameter values obtained utilizing PRIMOS was evaluated. RESULTS: A moderate correlation was found between the roughness parameter values and the clinical roughness grade. Our study showed that an overall relationship exists between the nail roughness parameter values obtained using PRIMOS and clinically observed nail surface changes. CONCLUSION: With further studies, PRIMOS could be a valuable tool for clinicians and researchers for conducting an accurate and objective patient assessment in daily practice and demonstrating effectiveness of different therapies for nail dystrophy or evaluating cosmetic effects of various topical treatments in future clinical trials.

Efficacy of a new dispatcher-assisted cardiopulmonary resuscitation protocol with audio call-to-video call transition.

BACKGROUND: Video call based dispatcher-assisted cardiopulmonary resuscitation (V-DACPR) has been suggested to improve the quality of bystander cardiopulmonary resuscitation. In the current system, dispatchers must convert the audio calls to video calls to provide V-DACPR. We aimed to develop new audio call-to-video call transition protocols and test its efficacy and safety compared to conventional DACPR(C-DACPR). METHODS: This was a randomized controlled simulation trial that compared the quality of bystander chest compression that was performed under three different DACPR protocols: C-DACPR, V-DACPR with rapid transition, and V-DACPR with delayed transition. Adult volunteers excluding healthcare providers were recruited for the trial. The primary outcome of the study was the mean proportion of adequate hand positioning during chest compression. RESULTS: Simulation results of 131 volunteers were analyzed. The mean proportion of adequate hand positioning was highest in V-DACPR with rapid transition (V-DACPR with rapid transition vs. C-DACPR: 92.7% vs. 82.4%, p = 0.03). The mean chest compression depth was deeper in both V-DACPR groups than in the C-DACPR group (V-DACPR with rapid transition vs. C-DACPR: 40.7 mm vs. 35.9 mm, p = 0.01, V-DACPR with delayed transition vs. C- DACPR: 40.9 mm vs. 35.9 mm, p = 0.01). Improvement in the proportion of adequate hand positioning was observed in the V-DACPR groups (r = 0.25, p < 0.01 for rapid transition and r = 0.19, p < 0.01 for delayed transition). CONCLUSION: Participants in the V-DACPR groups performed higher quality chest compression with higher appropriate hand positioning and deeper compression depth compared to the C-DACPR group.

Efficacy and Safety of a Novel Botulinum Toxin A for Masseter Reduction: A Randomized, Double-Blind, Placebo-Controlled, Optimal Dose-Finding Study.

BACKGROUND: A wide lower face and a square jaw are considered esthetic problems, particularly in Asia. OBJECTIVE: To investigate the optimal dose of a novel botulinum toxin (prabotulinum toxin A) for treating masseteric hypertrophy. METHODS: Ninety subjects with masseteric hypertrophy were randomly divided into 5 groups and treated with placebo (A, normal saline) or prabotulinum toxin A (B: 24, C: 48, D: 72, and E: 96 units). Photography, ultrasonography, and 3-dimensional imaging were performed before and after injection at baseline and at 4, 8, 12, and 16 weeks after treatment. The participants also rated their satisfaction. RESULTS: Masseter thickness significantly reduced in all groups at 12 weeks, compared with that in the placebo group. A dose-dependent reduction in masseter thickness was observed at the resting and maximal clenching positions. Sonography and 3-dimensional imaging revealed a gradual reduction in masseter thickness and volume, respectively, during the first 12 weeks. Despite being slightly effective, a dose of 24 units might be insufficient for resolving square face problems. Patients in Group E reported discomfort during jaw movement. CONCLUSION: Prabotulinum toxin A could effectively improve lower face contour without major complications, with an optimal dose of 48 to 72 units, followed by reinjection after 12 weeks.

Patch-Type Vibration Visualization (PVV) Sensor System Based on Triboelectric Effect.

Self-powered wireless sensor systems have emerged as an important topic for condition monitoring in nuclear power plants. However, commercial wireless sensor systems still cannot be fully self-sustainable due to the high power consumption caused by excessive signal processing in a mini-electronic computing system. In this sense, it is essential not only to integrate the sensor system with energy-harvesting devices but also to develop simple data processing methods for low power schemes. In this paper, we report a patch-type vibration visualization (PVV) sensor system based on the triboelectric effect and a visualization technique for self-sustainable operation. The PVV sensor system composed of a polyethylene terephthalate (PET)/Al/LCD screen directly converts the triboelectric signal into an informative black pattern on the LCD screen without excessive signal processing, enabling extremely low power operation. In addition, a proposed image processing method reconverts the black patterns to frequency and acceleration values through a remote-control camera. With these simple signal-to-pattern conversion and pattern-to-data reconversion techniques, a vibration visualization sensor network has successfully been demonstrated.

ONECUT2 upregulation is associated with CpG hypomethylation at promoter-proximal DNA in gastric cancer and triggers ACSL5.

Many studies have focused on global hypomethylation or hypermethylation of tumor suppressor genes, but less is known about the impact of promoter hypomethylation of oncogenes. We previously showed that promoter methylation may gradually increase or decrease during the transition from gastric mucosa (GM) to intestinal metaplasia (IM) to gastric cancer (GC). In our study, we focused on regional CpG hypomethylation of the promoter-proximal DNA of the transcription factor ONECUT2 (OC2) in IM and GC cells. We validated the hypomethylation of promoter-proximal DNA of OC2 in 160 primary GCs, in which methylation level correlated negatively with OC2 mRNA level. IM and GC cells stained positively for OC2, whereas GM cells did not. Stable transfection of OC2 in GC cells promoted colony formation, cell migration, invasion and proliferation. Moreover, OC2 knockdown with a short hairpin RNA suppressed tumorigenesis in nude mice. In addition, chromatin immunoprecipitation coupled with DNA sequencing and RNA-seq analyses revealed that OC2 triggered ACSL5, which is strongly expressed in IM of the stomach but not in GM, indicating that OC2 and ACSL5 are early-stage biomarkers for GC. We also observed a high correlation between the levels of OC2 and ACSL5 mRNAs in the GENT database These results suggest that epigenetic alteration of OC2 upregulates its expression, which then activates ACSL5; thus, OC2 is induced in IM by epigenetic alteration and triggers ACSL5 expression, and thus OC2 and ACSL5 may cooperatively promote intestinal differentiation and GC progression.

Boehmite enhances hair follicle growth via stimulation of dermal papilla cells by upregulating ß-catenin signalling.

Hair growth, a complex process, has long been the subject of intense research. Recent developments in material technology have revealed boehmite as a new therapeutic modality for use in wound healing and scar reduction, indicating its beneficial effects. Nonetheless, the biological bases of the beneficial effects of boehmite remain unknown. We investigated the hair growth properties of boehmite in vitro and in vivo and observed dose-dependent proliferation of human dermal papilla cells (hDPCs) in vitro and hair regrowth in a mouse model. To investigate the effects of boehmite on the promotion of cell transition to the anagen phase, we evaluated hDPC viability, alkaline phosphatase (ALP) activity, protein expression and vascular endothelial growth factor (VEGF) secretion in vitro and assessed the anagen-promoting effects of boehmite via gross observation and histological analysis in a mouse model. Boehmite increased hDPC viability, ALP activity, AKT/GSK3ß/ß-catenin pathway activity, anagen-related gene expression and VEGF secretion; moreover, it accelerated hair regrowth in a catagen-anagen transition model via upregulation of ß-catenin signalling and follicular cell proliferation. Collectively, our results indicate that boehmite accelerates hair growth, partly via its effects on critical events in the active phase of the hair follicle cycle, including the promotion of the proliferation of hDPCs and their immediate progeny to the follicle base.

310 nm UV-LEDs attenuate imiquimod-induced psoriasis-like skin lesions in C57BL/6 mice and inhibit IL-22-induced STAT3 expression in HaCaT cells.

Ultraviolet light-emitting diodes (UV-LEDs) are a novel light source for phototherapy. This study aimed to evaluate the therapeutic effects of UV-LEDs on psoriasis. Importantly, 310 nm UV-LEDs have not been studied in psoriasis in vitro and in vivo. Effects due to 310 nm UV-LED and 311 nm narrowband ultraviolet B (NBUVB) irradiation were compared for suppressing IL-22-induced activation of STAT3 expression using cell viability assay, western blotting, and immunocytochemistry. C57BL/6 mice were topically treated with imiquimod (IMQ) for 6 consecutive days and degenerative changes were observed. Test groups were irradiated with a 310 nm UV-LED and 311 nm NBUVB. Phenotypic observations, histopathological examinations, and ELISA were conducted with skin and blood samples. STAT3-dependent IL-22 signalling and effects in keratinocytes are negatively regulated by the 310 nm UV-LED, which significantly ameliorated IMQ-induced psoriasis-like dermatitis development and reduced Th17 cytokine levels (IL-17A, IL-22) in serum and dorsal skin. Histopathological findings showed decreases in epidermal thickness and inflammatory T-cell infiltration in the UV-LED-irradiated groups. Quantitative PCR confirmed a UV radiation energy-dependent decrease in IL-17A and IL-22 mRNA levels. The results demonstrated that UV-LEDs had anti-inflammatory and immunoregulatory effects. So, UV-LED phototherapy inhibits psoriasis development by suppressing STAT3 protein and inflammatory cytokines and could be useful in treating psoriasis.

Efficacy and Safety of High-Intensity Focused Ultrasound for Noninvasive Abdominal Subcutaneous Fat Reduction.

BACKGROUND: Demand for noninvasive body contouring has increased. OBJECTIVE: We evaluated the efficacy and safety of a thermal high-intensity focused ultrasound (HIFU) device for abdominal body shaping. PATIENTS AND METHODS: Adults with a body mass index ≤30 kg/m and an abdominal subcutaneous fat tissue thickness ≥2.5 cm were enrolled for HIFU treatment at energy levels of 150 J/cm (first session) and 135 J/cm (second session). The primary end point was a change from baseline waist circumference at post-treatment Week 8. Secondary efficacy end points were: changes in body weight, waist/hip ratio, and fat thickness assessed by ultrasound, caliper, and a fat CT scan. The Global Aesthetic Improvement Scale was evaluated by both investigators and subjects. RESULTS: The primary assessment achieved statistical significance, showing a reduction of 3.43 cm in mean waist circumference. The treatment effect was cumulative, with a steady decrease in waist circumference and fat thickness. The mean pain scores immediately after treatment were 4.45 ± 2.74 on a scale of 1 to 10 with 10 being the most painful, which decreased to 1.10 ± 1.33 after 1 week. CONCLUSION: High-intensity focused ultrasound is an effective and safe treatment modality for reducing waist circumference in nonobese individuals with focal fat accumulation.

The impact of phenanthrene on membrane phospholipids and its biodegradation by Sphingopyxis soli.

The direct interactions of bacterial membranes and polycyclic aromatic hydrocarbons (PAHs) strongly influence the biological processes, such as metabolic activity and uptake of substrates due to changes in membrane lipids. However, the elucidation of adaptation mechanisms as well as membrane phospholipid alterations in the presence of phenanthrene (PHE) from α-proteobacteria has not been fully explored. This study was conducted to define the degradation efficiency of PHE by Sphingopyxis soli strain KIT-001 in a newly isolated from Jeonju river sediments and to characterize lipid profiles in the presence of PHE in comparison to cells grown on glucose using quantitative lipidomic analysis. This strain was able to respectively utilize 1-hydroxy-2-naphthoic acid and salicylic acid as sole carbon source and approximately 90% of PHE (50 mg/L) was rapidly degraded via naphthalene route within 1 day incubation. In the cells grown on PHE, strain KIT-001 appeared to dynamically change profiles of metabolite and lipid in comparison to cells grown on glucose. The levels of primary metabolites, phosphatidylethanolamines (PE), and phosphatidic acids (PA) were significantly decreased, whereas the levels of phosphatidylcholines (PC) and phosphatidylglycerols (PG) were significantly increased. The adaptation mechanism of Sphingopyxis sp. regarded mainly the accumulation of bilayer forming lipids and anionic lipids to adapt more quickly under restricted nutrition and toxicity condition. Hence, these findings are conceivable that strain KIT-001 has a good adaptive ability and biodegradation for PHE through the alteration of phospholipids, and will be helpful for applications for effective bioremediation of PAHs-contaminated sites.

The Importance of Porins and ß-Lactamase in Outer Membrane Vesicles on the Hydrolysis of ß-Lactam Antibiotics.

Gram-negative bacteria have an outer membrane inhibiting the entry of antibiotics. Porins, found within the outer membrane, are involved in regulating the permeability of ß-lactam antibiotics. ß-lactamases are enzymes that are able to inactivate the antibacterial properties of ß-lactam antibiotics. Interestingly, porins and ß-lactamase are found in outer membrane vesicles (OMVs) of ß-lactam-resistant Escherichia coli and may be involved in the survival of susceptible strains of E. coli in the presence of antibiotics, through the hydrolysis of the ß-lactam antibiotic. In this study, OMVs isolated from ß-lactam-resistant E. coli and from mutants, lacking porin or ß-lactamase, were evaluated to establish if the porins or ß-lactamase in OMVs were involved in the degradation of ß-lactam antibiotics. OMVs isolated from E. coli deficient in ß-lactamase did not show any degradation ability against ß-lactam antibiotics, while OMVs lacking OmpC or OmpF showed significantly lower levels of hydrolyzing activity than OMVs from parent E. coli. These data reveal an important role of OMVs in bacterial defense mechanisms demonstrating that the OmpC and OmpF proteins allow permeation of ß-lactam antibiotics into the lumen of OMVs, and antibiotics that enter the OMVs can be degraded by ß-lactamase.

Proteomic analysis of whole-body responses in medaka (Oryzias latipes) exposed to benzalkonium chloride.

Benzalkonium chloride (BAC) is a cationic surfactant commonly used as a disinfectant, and is discharged into the aquatic environment by various water sources such as wastewater. BAC may also interact with potentially toxic substances such as persistent organic chemicals. Although studies of BAC contamination toxicity and bioaccumulation have been widely reported, the biochemical responses to BAC toxicity remain incompletely understood, and the detailed molecular mechanisms are largely unknown. In this study, two-dimensional gel electrophoresis (2-DE) and matrix-assisted laser desorption/ionization tandem time-of-flight mass spectrometry-based proteomic approaches were applied to investigate the protein profiles in Oryzias latipes (medaka) chronically exposed to BAC. Fish were exposed to three different concentrations of BAC, 0.05, 0.1, and 0.2 mg/L, for 21 days. A total of 20 proteins involved in the cytoskeleton, the oxidative stress response, the nervous and endocrine systems, signaling pathways, and cellular proteolysis were significantly upregulated by BAC exposure. The proteomic information obtained in the present study will be useful in identification of potential biomarkers for BAC toxicity, and begins to elucidate its molecular mechanisms, providing new insights into the ecotoxicity of BAC.

Dissipation of Herbicide Methiozolin and Its Metabolites in Aerobic Sediment-Water Systems.

Methiozolin is a novel herbicide for controlling annual bluegrass. After applying 14C labelled methiozolin in two sediment (clay loam and sand)-water systems under aerobic conditions, its distribution, half-life, and metabolites within 300 days were investigated. The mass balance ranged within 92.0%-104.4% of applied radioactivity (AR). Radioactivity in the water declined sharply from 94.4% to 0.5% AR, while in the sediment it increased to 83.9% AR at 14 days before declining to 9.1% AR. The volatiles were minimal (< 0.5% AR), and the evolved labelled CO2 accounted for up to ~ 33.4% AR. From Radio-HPLC analysis, labelled methiozolin in water decreased from 108.9% to 0% AR, while a maximum of 15.1% AR remained in the sediment at the end. Eight metabolites were detected, all at minor levels and accounting for < 5.5% AR. The half-life of labelled methiozolin in the total sediment-water systems were 50.7 and 38.7 days for clay loam and sand, respectively.