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1.
Autophagy ; : 1-34, 2024 Mar 24.
Artículo en Inglés | MEDLINE | ID: mdl-38442890

RESUMEN

Macroautophagy/autophagy is a complex degradation process with a dual role in cell death that is influenced by the cell types that are involved and the stressors they are exposed to. Ferroptosis is an iron-dependent oxidative form of cell death characterized by unrestricted lipid peroxidation in the context of heterogeneous and plastic mechanisms. Recent studies have shed light on the involvement of specific types of autophagy (e.g. ferritinophagy, lipophagy, and clockophagy) in initiating or executing ferroptotic cell death through the selective degradation of anti-injury proteins or organelles. Conversely, other forms of selective autophagy (e.g. reticulophagy and lysophagy) enhance the cellular defense against ferroptotic damage. Dysregulated autophagy-dependent ferroptosis has implications for a diverse range of pathological conditions. This review aims to present an updated definition of autophagy-dependent ferroptosis, discuss influential substrates and receptors, outline experimental methods, and propose guidelines for interpreting the results.Abbreviation: 3-MA:3-methyladenine; 4HNE: 4-hydroxynonenal; ACD: accidentalcell death; ADF: autophagy-dependentferroptosis; ARE: antioxidant response element; BH2:dihydrobiopterin; BH4: tetrahydrobiopterin; BMDMs: bonemarrow-derived macrophages; CMA: chaperone-mediated autophagy; CQ:chloroquine; DAMPs: danger/damage-associated molecular patterns; EMT,epithelial-mesenchymal transition; EPR: electronparamagnetic resonance; ER, endoplasmic reticulum; FRET: Försterresonance energy transfer; GFP: green fluorescent protein;GSH: glutathione;IF: immunofluorescence; IHC: immunohistochemistry; IOP, intraocularpressure; IRI: ischemia-reperfusion injury; LAA: linoleamide alkyne;MDA: malondialdehyde; PGSK: Phen Green™ SK;RCD: regulatedcell death; PUFAs: polyunsaturated fatty acids; RFP: red fluorescentprotein;ROS: reactive oxygen species; TBA: thiobarbituricacid; TBARS: thiobarbituric acid reactive substances; TEM:transmission electron microscopy.

2.
Environ Mol Mutagen ; 2023 Dec 19.
Artículo en Inglés | MEDLINE | ID: mdl-38115239

RESUMEN

Quantitative risk assessments of chemicals are routinely performed using in vivo data from rodents; however, there is growing recognition that non-animal approaches can be human-relevant alternatives. There is an urgent need to build confidence in non-animal alternatives given the international support to reduce the use of animals in toxicity testing where possible. In order for scientists and risk assessors to prepare for this paradigm shift in toxicity assessment, standardization and consensus on in vitro testing strategies and data interpretation will need to be established. To address this issue, an Expert Working Group (EWG) of the 8th International Workshop on Genotoxicity Testing (IWGT) evaluated the utility of quantitative in vitro genotoxicity concentration-response data for risk assessment. The EWG first evaluated available in vitro methodologies and then examined the variability and maximal response of in vitro tests to estimate biologically relevant values for the critical effect sizes considered adverse or unacceptable. Next, the EWG reviewed the approaches and computational models employed to provide human-relevant dose context to in vitro data. Lastly, the EWG evaluated risk assessment applications for which in vitro data are ready for use and applications where further work is required. The EWG concluded that in vitro genotoxicity concentration-response data can be interpreted in a risk assessment context. However, prior to routine use in regulatory settings, further research will be required to address the remaining uncertainties and limitations.

3.
Structure ; 31(12): 1567-1577.e5, 2023 12 07.
Artículo en Inglés | MEDLINE | ID: mdl-37794594

RESUMEN

The structure determination of protein tyrosine phosphatase (PTP): phospho-protein complexes, which is essential to understand how specificity is achieved at the amino acid level, remains a significant challenge for protein crystallography and cryoEM due to the transient nature of binding interactions. Using rPTPεD1 and phospho-SrcKD as a model system, we have established an integrative workflow to address this problem, by means of which we generate a protein:phospho-protein complex model using predetermined protein structures, SAXS and pTyr-tailored MD simulations. Our model reveals transient protein-protein interactions between rPTPεD1 and phospho-SrcKD and is supported by three independent experimental validations. Measurements of the association rate between rPTPεD1 and phospho-SrcKD showed that mutations on the rPTPεD1: SrcKD complex interface disrupts these transient interactions, resulting in a reduction in protein-protein association rate and, eventually, phosphatase activity. This integrative approach is applicable to other PTP: phospho-protein complexes and the characterization of transient protein-protein interface interactions.


Asunto(s)
Proteínas , Dispersión del Ángulo Pequeño , Difracción de Rayos X , Fosforilación
4.
Cell Death Dis ; 14(8): 540, 2023 08 22.
Artículo en Inglés | MEDLINE | ID: mdl-37607937

RESUMEN

Accumulating evidence has shown that the quality of proteins must be tightly monitored and controlled to maintain cellular proteostasis. Misfolded proteins and protein aggregates are targeted for degradation through the ubiquitin proteasome (UPS) and autophagy-lysosome systems. The ubiquitination and deubiquitinating enzymes (DUBs) have been reported to play pivotal roles in the regulation of the UPS system. However, the function of DUBs in the regulation of autophagy remain to be elucidated. In this study, we found that knockdown of Leon/USP5 caused a marked increase in the formation of autophagosomes and autophagic flux under well-fed conditions. Genetic analysis revealed that overexpression of Leon suppressed Atg1-induced cell death in Drosophila. Immunoblotting assays further showed a strong interaction between Leon/USP5 and the autophagy initiating kinase Atg1/ULK1. Depletion of Leon/USP5 led to increased levels of Atg1/ULK1. Our findings indicate that Leon/USP5 is an autophagic DUB that interacts with Atg1/ULK1, negatively regulating the autophagic process.


Asunto(s)
Autofagia , Proteínas de Drosophila , Animales , Autofagia/genética , Autofagosomas , Muerte Celular , Drosophila , Lisosomas , Complejo de la Endopetidasa Proteasomal , Ubiquitina , Enzimas Desubicuitinizantes , Homólogo de la Proteína 1 Relacionada con la Autofagia/genética , Proteínas de Drosophila/genética , Proteasas Ubiquitina-Específicas/genética
5.
Environ Int ; 171: 107727, 2023 01.
Artículo en Inglés | MEDLINE | ID: mdl-36628859

RESUMEN

Relative potency factors (RPFs) for per- and polyfluoroalkyl substances (PFAS) have previously been derived based on liver effects in rodents for the purpose of performing mixture risk assessment with primary input from biomonitoring studies. However, in 2020, EFSA established a tolerable weekly intake for four PFAS assuming equal toxic potency for immune suppressive effects in humans. In this study we explored the possibility of deriving RPFs for immune suppressive effects using available data in rodents and humans. Lymphoid organ weights, differential blood cell counts, and clinical chemistry from 28-day studies in male rats from the National Toxicology Program (NTP) were combined with modeled serum PFAS concentrations to derive internal RPFs by applying dose-response modelling. Identified functional studies used diverse protocols and were not suitable for derivation of RPFs but were used to support immunotoxicity of PFAS in a qualitative manner. Furthermore, a novel approach was used to estimate internal RPFs based on epidemiological data by dose-response curve fitting optimization, looking at serum antibody concentrations and key cell populations from the National Health and Nutrition Examination Survey (NHANES). Internal RPFs were successfully derived for PFAS based on rat thymus weight, spleen weight, and globulin concentration. The available dose-response information for blood cell counts did not show a significant trend. Immunotoxic potency in serum was determined in the order PFDA > PFNA > PFHxA > PFOS > PFBS > PFOA > PFHxS. The epidemiological data showed inverse associations for the sum of PFOA, PFNA, PFHxS, and PFOS with serum antibody concentrations to mumps and rubella, but the data did not allow for deduction of reliable internal RPF estimates. The internal RPFs for PFAS based on decreased rat lymphoid organ weights are similar to those previously established for increased rat liver weight, strengthening the confidence in the overall applicability of these RPFs.


Asunto(s)
Ácidos Alcanesulfónicos , Contaminantes Ambientales , Fluorocarburos , Humanos , Masculino , Animales , Ratas , Encuestas Nutricionales , Monitoreo Biológico , Hígado/química , Ácidos Alcanesulfónicos/toxicidad
6.
Environ Sci Process Impacts ; 25(1): 66-74, 2023 Jan 25.
Artículo en Inglés | MEDLINE | ID: mdl-36504232

RESUMEN

Organic compounds are capable of generating hydroxyl radicals (˙OH) through their excited triplet states in natural water. It is of significance to reveal the underlying mechanism of the generation and obtain the generation quantum yield of ˙OH from organic compounds for better understanding of its involvement in indirect photochemical processes in the environment. In this study, the ˙OH quantum yields (Φ˙OH) of 20 organic compounds were determined by photochemical experiments. The calculated Φ˙OH values for the selected organic compounds vary from (1.2 ± 0.39) × 10-5 to (7.2 ± 0.16) × 10-4. A quantitative structure-activity relationship (QSAR) model for log Φ˙OH was developed and the established model was proven to have a proper goodness of fit, robustness, and predictive ability. The QSAR model was successfully used to predict the Φ˙OH value of organic pollutants. Mechanistic interpretation showed that the electron distribution and the electronegativity of organic compounds are the most important factors that determine the generation of ˙OH. The results are helpful for understanding the generation mechanism of ˙OH from organic compounds and also provide insights into the generation of ˙OH from dissolved organic matter in natural water.


Asunto(s)
Radical Hidroxilo , Contaminantes Químicos del Agua , Radical Hidroxilo/química , Relación Estructura-Actividad Cuantitativa , Compuestos Orgánicos , Agua/química , Procesos Fotoquímicos , Contaminantes Químicos del Agua/análisis
7.
Autophagy ; 18(8): 2008-2010, 2022 08.
Artículo en Inglés | MEDLINE | ID: mdl-35380918

RESUMEN

High levels of reactive oxygen species (ROS) result in oxidative stress, which damages cells and leads to the development of many diseases. Macroautophagy/autophagy plays an important role in protecting cells from diverse stress stimuli including oxidative stress. However, the molecular mechanisms of autophagy activation in response to oxidative stress remain largely unclear. In this study, we showed that TRAF6 mediates oxidative stress-induced ATG9A ubiquitination at two C-terminal lysine residues (K581 and K838). ATG9A ubiquitination promotes its association with BECN1, BECN1-PIK3C3/VPS34-UVRAG complex assembly and PIK3C3/VPS34 activation, thereby activating autophagy and endocytic trafficking. We also identified TNFAIP3/A20 as a negative regulator of oxidative-induced autophagy by counteracting TRAF6-mediated ATG9A ubiquitination. Moreover, ATG9A depletion attenuates LPS-induced autophagy and causes aberrant TLR4 signaling and inflammatory responses. Our findings revealed a critical role of ATG9A ubiquitination in oxidative stress-induced autophagy, endocytic trafficking and innate immunity.


Asunto(s)
Autofagia , Factor 6 Asociado a Receptor de TNF , Autofagia/fisiología , Fosfatidilinositol 3-Quinasas Clase III , Estrés Oxidativo , Factor 6 Asociado a Receptor de TNF/metabolismo , Ubiquitinación
8.
Cell Rep ; 38(8): 110354, 2022 02 22.
Artículo en Inglés | MEDLINE | ID: mdl-35196483

RESUMEN

Excessive generation and accumulation of highly reactive oxidizing molecules causes oxidative stress and oxidative damage to cellular components. Accumulating evidence indicates that autophagy diminishes oxidative damage in cells and maintains redox homeostasis by degrading and recycling intracellular damaged components. Here, we show that TRAF6 E3 ubiquitin ligase and A20 deubiquitinase coordinate to regulate ATG9A ubiquitination and autophagy activation in cells responding to oxidative stress. The ROS-dependent TRAF6-mediated non-proteolytic, K48/63-linked ubiquitination of ATG9A enhances its association with Beclin 1 and the assembly of VPS34-UVRAG complex, thereby stimulating autophagy. Notably, expression of the ATG9A ubiquitination mutants impairs ROS-induced VPS34 activation and autophagy. We further find that lipopolysaccharide (LPS)-induced ROS production also stimulates TRAF6-mediated ATG9A ubiquitination. Ablation of ATG9A causes aberrant TLR4 endosomal trafficking and decreases IRF-3 phosphorylation in LPS-stimulated macrophages. Our findings provide important insights into how K48/K63-linked ubiquitination of ATG9A contributes to the regulation of oxidative stress-induced autophagy.


Asunto(s)
Factor 6 Asociado a Receptor de TNF , Ubiquitina-Proteína Ligasas , Autofagia/fisiología , Estrés Oxidativo , Factor 6 Asociado a Receptor de TNF/metabolismo , Ubiquitina-Proteína Ligasas/metabolismo , Ubiquitinación
9.
IUBMB Life ; 74(4): 339-360, 2022 04.
Artículo en Inglés | MEDLINE | ID: mdl-34874101

RESUMEN

Autophagy regulates cellular homeostasis by degrading and recycling cytosolic components and damaged organelles. Disruption of autophagic flux has been shown to induce or facilitate neurodegeneration and accumulation of autophagic vesicles is overt in neurodegenerative diseases. The fruit fly Drosophila has been used as a model system to identify new factors that regulate physiology and disease. Here we provide a historical perspective of how the fly models have offered mechanistic evidence to understand the role of autophagy in neurodegenerative diseases including Alzheimer's disease, Parkinson's disease, Charcot-Marie-Tooth neuropathy, and polyglutamine disorders. Autophagy also plays a pivotal role in maintaining tissue homeostasis and protecting organism health. The gastrointestinal tract regulates organism health by modulating food intake, energy balance, and immunity. Growing evidence is strengthening the link between autophagy and digestive tract health in recent years. Here, we also discuss how the fly models have advanced the understanding of digestive physiology regulated by autophagy.


Asunto(s)
Enfermedad de Alzheimer , Enfermedades Neurodegenerativas , Animales , Autofagia/genética , Drosophila/genética , Tracto Gastrointestinal , Enfermedades Neurodegenerativas/genética
10.
J Biomed Sci ; 28(1): 72, 2021 Oct 27.
Artículo en Inglés | MEDLINE | ID: mdl-34706729

RESUMEN

BACKGROUND: During autophagy defense against invading microbes, certain lipid types are indispensable for generating specialized membrane-bound organelles. The lipid composition of autophagosomes remains obscure, as does the issue of how specific lipids and lipid-associated enzymes participate in autophagosome formation and maturation. Helicobacter pylori is auxotrophic for cholesterol and converts cholesterol to cholesteryl glucoside derivatives, including cholesteryl 6'-O-acyl-α-D-glucoside (CAG). We investigated how CAG and its biosynthetic acyltransferase assist H. pylori to escape host-cell autophagy. METHODS: We applied a metabolite-tagging method to obtain fluorophore-containing cholesteryl glucosides that were utilized to understand their intracellular locations. H. pylori 26695 and a cholesteryl glucosyltransferase (CGT)-deletion mutant (ΔCGT) were used as the standard strain and the negative control that contains no cholesterol-derived metabolites, respectively. Bacterial internalization and several autophagy-related assays were conducted to unravel the possible mechanism that H. pylori develops to hijack the host-cell autophagy response. Subcellular fractions of H. pylori-infected AGS cells were obtained and measured for the acyltransferase activity. RESULTS: The imaging studies of fluorophore-labeled cholesteryl glucosides pinpointed their intracellular localization in AGS cells. The result indicated that CAG enhances the internalization of H. pylori in AGS cells. Particularly, CAG, instead of CG and CPG, is able to augment the autophagy response induced by H. pylori. How CAG participates in the autophagy process is multifaceted. CAG was found to intervene in the degradation of autophagosomes and reduce lysosomal biogenesis, supporting the idea that intracellular H. pylori is harbored by autophago-lysosomes in favor of the bacterial survival. Furthermore, we performed the enzyme activity assay of subcellular fractions of H. pylori-infected AGS cells. The analysis showed that the acyltransferase is mainly distributed in autophago-lysosomal compartments. CONCLUSIONS: Our results support the idea that the acyltransferase is mainly distributed in the subcellular compartment consisting of autophagosomes, late endosomes, and lysosomes, in which the acidic environment is beneficial for the maximal acyltransferase activity. The resulting elevated level of CAG can facilitate bacterial internalization, interfere with the autophagy flux, and causes reduced lysosomal biogenesis.


Asunto(s)
Aciltransferasas/metabolismo , Colesterol/análogos & derivados , Infecciones por Helicobacter/fisiopatología , Helicobacter pylori/fisiología , Lisosomas/fisiología , Animales , Colesterol/biosíntesis , Infecciones por Helicobacter/enzimología , Infecciones por Helicobacter/microbiología , Masculino , Ratones , Ratones Endogámicos C57BL , Organismos Libres de Patógenos Específicos
11.
Environ Pollut ; 291: 118189, 2021 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-34543954

RESUMEN

Antibiotic resistance in environmental matrices becomes urgently significant for public health and has been considered as an emerging environmental contaminant. In this work, the ampicillin-resistant Escherichia coli (AR E. coli) and corresponding resistance genes (blaTEM-1) were effectively eliminated by the electrocatalytic process, and the dissemination risk of antibiotic resistance was also investigated. All the AR E. coli (∼8 log) was inactivated and 8.17 log blaTEM-1 was degraded by the carbon nanotubes/agarose/titanium (CNTs/AG/Ti) electrode within 30 min. AR E. coli was inactivated mainly attributing to the damage of cell membrane, which was attacked by reactive oxygen species and subsequent leakage of intracellular cytoplasm. The blaTEM-1 was degraded owing to the strand breaking in the process of electrocatalytic degradation. Furthermore, the dissemination risk of antibiotic resistance was effectively controlled after being electrocatalytic treatment. This study provided an effective electrocatalytic technology for the inactivation of antibiotic resistant bacteria and control of antibiotic resistance dissemination risk in the aqueous environment.


Asunto(s)
Antibacterianos , Nanotubos de Carbono , Antibacterianos/farmacología , Bacterias , Farmacorresistencia Microbiana , Escherichia coli
12.
Nat Commun ; 12(1): 1322, 2021 02 26.
Artículo en Inglés | MEDLINE | ID: mdl-33637724

RESUMEN

The ubiquitin-proteasome system (UPS) and autophagy are two major quality control processes whose impairment is linked to a wide variety of diseases. The coordination between UPS and autophagy remains incompletely understood. Here, we show that ubiquitin ligase UBE3C and deubiquitinating enzyme TRABID reciprocally regulate K29/K48-branched ubiquitination of VPS34. We find that this ubiquitination enhances the binding of VPS34 to proteasomes for degradation, thereby suppressing autophagosome formation and maturation. Under ER and proteotoxic stresses, UBE3C recruitment to phagophores is compromised with a concomitant increase of its association with proteasomes. This switch attenuates the action of UBE3C on VPS34, thereby elevating autophagy activity to facilitate proteostasis, ER quality control and cell survival. Specifically in the liver, we show that TRABID-mediated VPS34 stabilization is critical for lipid metabolism and is downregulated during the pathogenesis of steatosis. This study identifies a ubiquitination type on VPS34 and elucidates its cellular fate and physiological functions in proteostasis and liver metabolism.


Asunto(s)
Autofagia/fisiología , Fosfatidilinositol 3-Quinasas Clase III/metabolismo , Hígado/metabolismo , Proteostasis/fisiología , Ubiquitina-Proteína Ligasas/metabolismo , Ubiquitina/metabolismo , Ubiquitinación/fisiología , Animales , Autofagosomas/metabolismo , Fosfatidilinositol 3-Quinasas Clase III/genética , Dieta Alta en Grasa/efectos adversos , Células HEK293 , Células HeLa , Humanos , Masculino , Ratones Endogámicos C57BL , Complejo de la Endopetidasa Proteasomal/metabolismo , Ubiquitina-Proteína Ligasas/genética , Ubiquitinación/genética
13.
Autophagy ; 17(10): 2750-2765, 2021 10.
Artículo en Inglés | MEDLINE | ID: mdl-33112705

RESUMEN

Macroautophagy/autophagy is an evolutionarily conserved intracellular pathway for the degradation of cytoplasmic materials. Under stress conditions, autophagy is upregulated and double-membrane autophagosomes are formed by the expansion of phagophores. The ATG16L1 precursor fusion contributes to development of phagophore structures and is critical for the biogenesis of autophagosomes. Here, we discovered a novel role of the protein tyrosine phosphatase PTPN9 in the regulation of homotypic ATG16L1 vesicle fusion and early autophagosome formation. Depletion of PTPN9 and its Drosophila homolog Ptpmeg2 impaired autophagosome formation and autophagic flux. PTPN9 colocalized with ATG16L1 and was essential for homotypic fusion of ATG16L1+ vesicles during starvation-induced autophagy. We further identified the Q-SNARE VTI1B as a substrate target of PTPN9 phosphatase. Like PTPN9, the VTI1B nonphosphorylatable mutant but not the phosphomimetic mutant enhanced SNARE complex assembly and autophagic flux. Our findings highlight the important role of PTPN9 in the regulation of ATG16L1+ autophagosome precursor fusion and autophagosome biogenesis through modulation of VTI1B phosphorylation status.Abbreviations: csw: corkscrew; EBSS: Earle's balanced salt solution; ERGIC: ER-Golgi intermediate compartment; ESCRT: endosomal sorting complexes required for transport; mop: myopic; NSF: N-ethylmaleimide-sensitive factor; PAS: phagophore assembly site; PolyQ: polyglutamine; PtdIns3P: phosphatidylinositol-3-phosphate; PTK: protein tyrosine kinase; PTM: posttranslational modification; PTP: protein tyrosine phosphatase; PTPN23/HD-PTP: protein tyrosine phosphatase non-receptor type 23; SNARE: soluble N-ethylmaleimide sensitive factor attachment protein receptor; STX7: syntaxin 7; STX8: syntaxin 8; STX17: syntaxin 17; VAMP3: vesicle associated membrane protein 3; VAMP7: vesicle associated membrane protein 7; VTI1B: vesicle transport through interaction with t-SNAREs 1B; YKT6: YKT6 v-SNARE homolog; ZFYVE1/DFCP1: zinc finger FYVE-type containing 1.


Asunto(s)
Autofagosomas , Proteínas Relacionadas con la Autofagia , Macroautofagia , Proteínas Tirosina Fosfatasas no Receptoras , Proteínas Qb-SNARE , Autofagosomas/metabolismo , Autofagia/fisiología , Proteínas Relacionadas con la Autofagia/metabolismo , Células HeLa , Humanos , Fusión de Membrana , Proteínas Tirosina Fosfatasas no Receptoras/genética , Proteínas Tirosina Fosfatasas no Receptoras/metabolismo , Proteínas Qb-SNARE/metabolismo
14.
Aging Cell ; 19(8): e13191, 2020 08.
Artículo en Inglés | MEDLINE | ID: mdl-32666649

RESUMEN

Changes in mitochondrial dynamics (fusion and fission) are known to occur during stem cell differentiation; however, the role of this phenomenon in tissue aging remains unclear. Here, we report that mitochondrial dynamics are shifted toward fission during aging of Drosophila ovarian germline stem cells (GSCs), and this shift contributes to aging-related GSC loss. We found that as GSCs age, mitochondrial fragmentation and expression of the mitochondrial fission regulator, Dynamin-related protein (Drp1), are both increased, while mitochondrial membrane potential is reduced. Moreover, preventing mitochondrial fusion in GSCs results in highly fragmented depolarized mitochondria, decreased BMP stemness signaling, impaired fatty acid metabolism, and GSC loss. Conversely, forcing mitochondrial elongation promotes GSC attachment to the niche. Importantly, maintenance of aging GSCs can be enhanced by suppressing Drp1 expression to prevent mitochondrial fission or treating with rapamycin, which is known to promote autophagy via TOR inhibition. Overall, our results show that mitochondrial dynamics are altered during physiological aging, affecting stem cell homeostasis via coordinated changes in stemness signaling, niche contact, and cellular metabolism. Such effects may also be highly relevant to other stem cell types and aging-induced tissue degeneration.


Asunto(s)
Células Madre Germinales Adultas/metabolismo , Dinámicas Mitocondriales/genética , Células Madre/metabolismo , Animales , Diferenciación Celular , Proliferación Celular , Drosophila , Femenino , Masculino , Transducción de Señal
15.
Sci Total Environ ; 712: 136450, 2020 Apr 10.
Artículo en Inglés | MEDLINE | ID: mdl-31931195

RESUMEN

Singlet oxygen (1O2) is capable of degrading organic contaminants and inducing cell damage and inactivation of viruses. It is mainly generated through the interaction of dissolved oxygen with excited triplet states of dissolved organic matter (DOM) in natural waters. The present study aims at revealing the underlying mechanism of 1O2 generation and providing a potential tool for predicting the quantum yield of 1O2 (Φ1O2) generation from DOM by constructing a quantitative structure-activity relationship (QSAR) model. The determined Φ1O2 values for the selected DOM-analogs range from (0.54 ± 0.23) × 10-2 to (62.03 ± 2.97) × 10-2. A QSAR model was constructed and was proved to have satisfactory goodness-of-fit and robustness. The QSAR model was successfully used to predict the Φ1O2 of Suwannee River fulvic acid. Mechanistic interpretation of the descriptors in the model showed that hydrophobicity, molecular complexity and the presence of carbonyl groups in DOM play crucial roles in the generation of 1O2 from DOM. The presence of other heteroatoms besides O, such as N and S, also affects the generation of 1O2. The results of this study provide valuable insights into the generation of 1O2 from DOM in sunlit natural waters.

16.
Sci Total Environ ; 708: 133863, 2020 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-31771845

RESUMEN

Attenuation of organic compounds in sewage treatment plants (STPs) is affected by a complex interplay between chemical (e.g. ionization, hydrolysis), physical (e.g. sorption, volatilization), and biological (e.g. biodegradation, microbial acclimation) processes. These effects should be accounted for individually, in order to develop predictive cheminformatics tools for STPs. Using measured data from 70 STPs in the Netherlands for 69 chemicals (pharmaceuticals, herbicides, etc.), we highlighted the influences of 1) chemical ionization, 2) sorption to sludge, and 3) acclimation of the microbial consortia on the primary removal of chemicals. We used semi-empirical corrections for each of these influences to deduce biodegradation rate constants upon which quantitative structure-biodegradation relationships (QSBRs) were developed. As shown by a global QSBR, biodegradation in STPs generally relates to structural complexity, size, energetics, and charge distribution. Statistics of the global QSBR were reasonable, being R2training=0.69 (training set of 51 compounds) and R2validation=0.50 (validation set of 18 compounds). Class-specific QSBRs utilized electronic properties potentially relating to rate-limiting enzymatic steps. For class-specific QSBRs, values of R2 of in between 0.7 and 0.8 were obtained. With caution, environmental risk assessment methodologies may apply these models to estimate biodegradation rates for 'data-poor' compounds. The approach also highlights 'meta data' on STP operational parameters needed to develop QSBRs of better predictability in the future.


Asunto(s)
Aguas Residuales , Biodegradación Ambiental , Consorcios Microbianos , Países Bajos , Aguas del Alcantarillado , Eliminación de Residuos Líquidos , Contaminantes Químicos del Agua
17.
Oncogene ; 38(44): 7002-7016, 2019 10.
Artículo en Inglés | MEDLINE | ID: mdl-31406243

RESUMEN

Cancer cell migration plays a crucial role during the metastatic process. Reversible tyrosine phosphorylation by protein tyrosine kinases (PTKs) and protein tyrosine phosphatases (PTPs) have been implicated in the regulation of cancer cell migration and invasion. However, the underlying mechanisms have not been fully elucidated. Here, we show that depletion of the FERM and PDZ domain-containing protein tyrosine phosphatase PTPN3 enhances lung cancer cell migration/invasion and metastasis by promoting actin filament assembly and focal adhesion dynamics. We further identified Src and DAAM1 (dishevelled associated activator of morphogenesis 1) as interactors of PTPN3. DAAM1 is a formin-like protein involved in the regulation of actin cytoskeletal remodeling. PTPN3 inhibits Src activity and Src-mediated phosphorylation of Tyr652 on DAAM1. The tyrosine phosphorylation of DAAM1 is essential for DAAM1 homodimer formation and actin polymerization. Ectopic expression of a DAAM1 phosphodeficient mutant inhibited F-actin assembly and suppressed lung cancer cell migration and invasion. Our findings reveal a novel mechanism by which reversible tyrosine phosphorylation of DAAM1 by Src and PTPN3 regulates actin dynamics and lung cancer invasiveness.


Asunto(s)
Actinas/metabolismo , Neoplasias Pulmonares/patología , Proteínas de Microfilamentos/metabolismo , Invasividad Neoplásica , Proteína Tirosina Fosfatasa no Receptora Tipo 3/fisiología , Proteínas Proto-Oncogénicas p21(ras)/metabolismo , Proteínas de Unión al GTP rho/metabolismo , Adhesiones Focales , Humanos , Polimerizacion
18.
Autophagy ; 15(10): 1829-1833, 2019 10.
Artículo en Inglés | MEDLINE | ID: mdl-31234750

RESUMEN

The NIH-funded center for autophagy research named Autophagy, Inflammation, and Metabolism (AIM) Center of Biomedical Research Excellence, located at the University of New Mexico Health Science Center is now completing its second year as a working center with a mission to promote autophagy research locally, nationally, and internationally. The center has thus far supported a cadre of 6 junior faculty (mentored PIs; mPIs) at a near-R01 level of funding. Two mPIs have graduated by obtaining their independent R01 funding and 3 of the remaining 4 have won significant funding from NIH in the form of R21 and R56 awards. The first year and a half of setting up the center has been punctuated by completion of renovations and acquisition and upgrades for equipment supporting autophagy, inflammation and metabolism studies. The scientific cores usage, and the growth of new studies is promoted through pilot grants and several types of enablement initiatives. The intent to cultivate AIM as a scholarly hub for autophagy and related studies is manifested in its Vibrant Campus Initiative, and the Tuesday AIM Seminar series, as well as by hosting a major scientific event, the 2019 AIM symposium, with nearly one third of the faculty from the International Council of Affiliate Members being present and leading sessions, giving talks, and conducting workshop activities. These and other events are often videostreamed for a worldwide scientific audience, and information about events at AIM and elsewhere are disseminated on Twitter and can be followed on the AIM web site. AIM intends to invigorate research on overlapping areas between autophagy, inflammation and metabolism with a number of new initiatives to promote metabolomic research. With the turnover of mPIs as they obtain their independent funding, new junior faculty are recruited and appointed as mPIs. All these activities are in keeping with AIM's intention to enable the next generation of autophagy researchers and help anchor, disseminate, and convey the depth and excitement of the autophagy field.


Asunto(s)
Autofagia/fisiología , Investigación Biomédica/organización & administración , Inflamación , Metabolismo/fisiología , Sociedades Científicas , Investigación Biomédica/economía , Investigación Biomédica/tendencias , Docentes Médicos/economía , Docentes Médicos/educación , Financiación Gubernamental , Organización de la Financiación/economía , Historia del Siglo XXI , Humanos , Inflamación/etiología , Inflamación/patología , Mentores , National Institutes of Health (U.S.)/economía , New Mexico , Investigadores/economía , Investigadores/educación , Sociedades Científicas/economía , Sociedades Científicas/organización & administración , Sociedades Científicas/normas , Sociedades Científicas/tendencias , Estados Unidos
19.
Pak J Pharm Sci ; 32(1(Special)): 439-444, 2019 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-30852482

RESUMEN

Celecoxib is the most recent non steroidal anti-inflammatory analgesic, and has been gradually used in the treatment of acute pain, rheumatism and osteoarthritis. This paper analyzes the analgesic effect of celecoxib in the treatment of knee osteoarthritis and put forward a new mechanism of knee joint extensor reconstruction assisted by bone anchor. The experimental group was given celecoxib 200 mg/ time and 1 time /d. The results showed that VAS (Visual Analogue Scale) decreased gradually in both groups on the 1st, 3rd and 7th day of treatment and VAS in experimental group was lower than that in control group at the same time point (P<0.05). At the 1 year follow-up, experience group had a significant improvement on the Lysholm (69.33 ± 8.38 preoperatively and 88.65 ± 12.93 postoperatively) and Kujula (69.33 ± 8.38 preoperatively and 88.65 ±12.93 postoperatively) knee scores (P<0.05). The results showed that celecoxib had a good analgesic effect in patients with knee osteoarthritis and reducing the release of inflammatory factors may be its mechanism..


Asunto(s)
Antiinflamatorios no Esteroideos/uso terapéutico , Artralgia/tratamiento farmacológico , Celecoxib/uso terapéutico , Osteoartritis de la Rodilla/tratamiento farmacológico , Luxación de la Rótula , Anclas para Sutura , Adolescente , Adulto , Antiinflamatorios no Esteroideos/administración & dosificación , Celecoxib/administración & dosificación , Femenino , Humanos , Masculino , Persona de Mediana Edad , Luxación de la Rótula/tratamiento farmacológico , Luxación de la Rótula/cirugía , Resultado del Tratamiento , Adulto Joven
20.
Autophagy ; 14(6): 925-929, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-29938597

RESUMEN

Recently, NIH has funded a center for autophagy research named the Autophagy, Inflammation, and Metabolism (AIM) Center of Biomedical Research Excellence, located at the University of New Mexico Health Science Center (UNM HSC), with aspirations to promote autophagy research locally, nationally, and internationally. The center has 3 major missions: (i) to support junior faculty in their endeavors to develop investigations in this area and obtain independent funding; (ii) to develop and provide technological platforms to advance autophagy research with emphasis on cellular approaches for high quality reproducible research; and (iii) to foster international collaborations through the formation of an International Council of Affiliate Members and through hosting national and international workshops and symposia. Scientifically, the AIM center is focused on autophagy and its intersections with other processes, with emphasis on both fundamental discoveries and applied translational research.


Asunto(s)
Autofagia , Investigación Biomédica , Inflamación/patología , Cooperación Internacional , Investigadores , Congresos como Asunto , Difusión de la Información
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