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1.
bioRxiv ; 2024 Jun 14.
Artículo en Inglés | MEDLINE | ID: mdl-38915701

RESUMEN

Purpose: ADP-ribosylation is a post-translational modification involving the transfer of one or more ADP-ribose units from NAD+ to target proteins. Dysregulation of ADP-ribosylation is implicated in neurodegenerative diseases. Here we report a novel homozygous variant in the ADPRS gene (c.545A>G, p.His182Arg) encoding the mono(ADP-ribosyl) hydrolase ARH3 found in 2 patients with childhood-onset neurodegeneration with stress-induced ataxia and seizures (CONDSIAS). Methods: Genetic testing via exome sequencing was used to identify the underlying disease cause in two siblings with developmental delay, seizures, progressive muscle weakness, and respiratory failure following an episodic course. Studies in a cell culture model uncover biochemical and cellular consequences of the identified genetic change. Results: The ARH3 H182R variant affects a highly conserved residue in the active site of ARH3, leading to protein instability, degradation, and reduced expression. ARH3 H182R additionally fails to localize to the nucleus. The combination of reduced expression and mislocalization of ARH3 H182R resulted in accumulation of mono-ADP ribosylated species in cells. Conclusions: The children's clinical course combined with the biochemical characterization of their genetic variant develops our understanding of the pathogenic mechanisms driving CONDSIAS and highlights a critical role for ARH3-regulated ADP ribosylation in nervous system integrity.

2.
Urol Case Rep ; 54: 102733, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38655151

RESUMEN

Metanephric adenoma presents as a rare benign tumor in children with differentiated diagnoses: Wilms tumor or renal cell carcinoma. When confronted with small renal tumors, whether they fall into one of these three diagnostic categories, tumor resection surgery with laparoscopic partial nephrectomy is considered a viable and effective operative approach. Herein, we report the case of an 11-year-old female patient initially diagnosed with stage T1a renal cell carcinoma with postoperative pathology results confirming metanephric adenoma. Successfully treated with laparoscopic partial nephrectomy, the patient showed no signs of recurrence or metastasis during follow-up.

3.
J Am Chem Soc ; 146(15): 10993-11001, 2024 Apr 17.
Artículo en Inglés | MEDLINE | ID: mdl-38579283

RESUMEN

Photoreactions of (coumarin-4-yl)methyl derivatives have been extensively studied in many fields of chemistry, including organic synthesis and photoinduced drug delivery systems. The identification of the reaction intermediates involved in the photoreactions is crucial not only for elucidating the reaction mechanism but also for the application of the photoreactions. In this study, the photoreactions of 7-diethylamino(coumarin-4-yl)methyl thioester 1a [-SC(O)CH3], thionoester 1b [-OC(S)CH3], and ester 1c [-OC(O)CH3] were investigated to clarify the intermediary species and their chemical behavior. While a radical pair [i.e., 7-diethylamino(coumarin-4-yl)methyl radical and CH3C(O)S•] plays an important role in the photoreactions of 1a and 1b, an ion pair [i.e., 7-diethylamino(coumarin-4-yl)methyl cation, and CH3CO2-] was the key in the photoreaction of 1c. 18O-isotope-labeling of 1c revealed a negligible recombination process within the ion pair. The unprecedented observation was rationalized by the open-shell character of the 7-diethylamino(coumarin-4-yl)methyl cation, whose formation was confirmed through product analysis and transient absorption spectroscopy.

4.
J Org Chem ; 89(7): 4691-4701, 2024 Apr 05.
Artículo en Inglés | MEDLINE | ID: mdl-38502935

RESUMEN

Photoremovable protecting groups (PPGs) are powerful tools that are widely used to investigate biological events in cells. An important requirement for PPGs is the efficient release of bioactive molecules by using visible to near-infrared light in the biological window (650-1350 nm). In this study, we report a new two-photon (2P)-responsive PPG, 2-(p-aminophenyl)-5,6-dimethoxy-1-(hydroxyinden-3-yl)methyl, with a donor-π-donor cyclic stilbene structure. The 2P cross section was approximately 40-50 GM at ∼700 nm. The quantum yield of the uncaging process of caged benzoate was greater than 0.7, demonstrating that the 2P uncaging efficiency was approximately 30 GM at around 700 nm. This newly developed 2P-responsive chromophore can be used in future biological experiments. The mechanism of the photo-uncaging reaction via the carbocation intermediate was elucidated using transient absorption spectroscopy and product analysis.

5.
Heliyon ; 10(4): e26174, 2024 Feb 29.
Artículo en Inglés | MEDLINE | ID: mdl-38404825

RESUMEN

Context: The Piper species was studied several potential properties such as anti-tumor, anti-inflammatory and antioxidant activity. However, the specific anti-inflammatory activity of the extract from the fruits of P. longum L. has not been investigated. Objectives: Our study want to examine the anti-inflammatory effects of P. longum L. fruit methanolic extracts (PLE) on lipopolysachharide (LPS)-stimulated RAW 264.7 murine macrophages to understand the mechanism of this effect. Method: This study examined the chemical profiling of PLE by LC-HRMS analysis and measured the presence of nitric oxide (NO), interleukin-6 (IL-6) and tumor necrosis factor alpha (TNF-α) in the supernatant using the Griess reagent assay and enzyme-linked immunosorbent assay (ELISA), respectively. The mRNA expression of IL-6, TNF-α, cyclooxygenase-2 (COX-2), and inducible nitric oxide synthase (iNOS) were evaluated by using real-time quantitative polymerase chain reaction (RT-qPCR). Furthermore, the protein expression of COX-2, iNOS and the phosphorylation of MAPK family, c-Jun N-terminal kinase (JNK), p38 in protein level were observed by western blotting. Result: PLE have detected 66 compounds which belong to different classes such as alkaloids, flavonoids, terpenoids, phenolics, lactones, and organic acids inhibited nitric oxide products with the IC50 = 28.5 ± 0.91 µg/mL. Moreover, PLE at 10-100 µg/mL up-regulate HO-1 protein expression from 3 to 10 folds at 3 h. It also downregulated the mRNA and protein expression of iNOS, COX-2, decreased IL-6 and TNF-α secretion by modulating the mitogen-activated protein kinase (MAPK) signaling pathway, specifically by decreasing the phosphorylation of p38 and JNK. Conclusion: These results shown chemical profiling of PLE and demonstrated that PLE exhibits anti-inflammatory effects by regulating the MAPK family and could be a potential candidate for the treatment of inflammatory diseases.

6.
Sci Rep ; 14(1): 2261, 2024 Jan 27.
Artículo en Inglés | MEDLINE | ID: mdl-38278846

RESUMEN

Inertial electrostatic confinement fusion (IECF) devices often use two concentric spherical electrodes to converge ions in a plasma electrostatically. Using a highly transparent inner cathode, the ions can move through the cathode and collide at the center to undergo fusion reactions. This is a simple method to build a neutron source. Past research has focused chiefly on cathode "grids" manufactured by joining metal wire loops or disc-shaped elements via spot welding. There are two common geometries: "Globe" grids with a distinct latitude-longitude structure and "symmetric" grids with even-sized triangular-shaped apertures. Recent advances in additive manufacturing have opened the way to manufacturing a third class of grids in which the apertures are evenly distributed over the grid surface and have either circular or polygonal shaped apertures - here called "regular" grids. These three types are analyzed and compared based on a set of metrics, including transparency, homogeneity of aperture size, and the regularity of aperture distribution. It is shown that every type of grid comes with different advantages and disadvantages. The analysis focuses on grid geometries with 6 to 120 apertures.

7.
Cancer Res ; 84(4): 577-597, 2024 02 15.
Artículo en Inglés | MEDLINE | ID: mdl-37967363

RESUMEN

RNA splicing factor (SF) gene mutations are commonly observed in patients with myeloid malignancies. Here we showed that SRSF2- and U2AF1-mutant leukemias are preferentially sensitive to PARP inhibitors (PARPi), despite being proficient in homologous recombination repair. Instead, SF-mutant leukemias exhibited R-loop accumulation that elicited an R-loop-associated PARP1 response, rendering cells dependent on PARP1 activity for survival. Consequently, PARPi induced DNA damage and cell death in SF-mutant leukemias in an R-loop-dependent manner. PARPi further increased aberrant R-loop levels, causing higher transcription-replication collisions and triggering ATR activation in SF-mutant leukemias. Ultimately, PARPi-induced DNA damage and cell death in SF-mutant leukemias could be enhanced by ATR inhibition. Finally, the level of PARP1 activity at R-loops correlated with PARPi sensitivity, suggesting that R-loop-associated PARP1 activity could be predictive of PARPi sensitivity in patients harboring SF gene mutations. This study highlights the potential of targeting different R-loop response pathways caused by spliceosome gene mutations as a therapeutic strategy for treating cancer. SIGNIFICANCE: Spliceosome-mutant leukemias accumulate R-loops and require PARP1 to resolve transcription-replication conflicts and genomic instability, providing rationale to repurpose FDA-approved PARP inhibitors for patients carrying spliceosome gene mutations.


Asunto(s)
Leucemia , Empalmosomas , Humanos , Empalmosomas/genética , Estructuras R-Loop , Inhibidores de Poli(ADP-Ribosa) Polimerasas/farmacología , Inhibidores de Poli(ADP-Ribosa) Polimerasas/uso terapéutico , Reparación del ADN , Leucemia/tratamiento farmacológico , Leucemia/genética , Factores de Empalme de ARN/genética , Poli(ADP-Ribosa) Polimerasa-1/genética
8.
Small ; 19(42): e2301037, 2023 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-37330659

RESUMEN

Many devices heavily rely on combinatorial material optimization. However, new material alloys are classically developed by studying only a fraction of giant chemical space, while many intermediate compositions remain unmade in light of the lack of methods to synthesize gapless material libraries. Here report a high-throughput all-in-one material platform to obtain and study compositionally-tunable alloys from solution is reported. This strategy is applied to make all Csx MAy FAz PbI3 perovskite alloys (MA and FA stand for methylammonium and formamidinium, respectively), in less than 10 min, on a single film, on which 520 unique alloys are then studied. Through stability mapping of all these alloys in air supersaturated with moisture, a range of targeted perovskites are found, which are then chosen to make efficient and stable solar cells in relaxed fabrication conditions, in ambient air. This all-in-one platform provides access to an unprecedented library of compositional space with no unmade alloys, and hence aids in a comprehensive accelerated discovery of efficient energy materials.

9.
bioRxiv ; 2023 Apr 25.
Artículo en Inglés | MEDLINE | ID: mdl-37163118

RESUMEN

Prostate cancer (PCa) remains the most diagnosed non-skin cancer amongst the American male population. Treatment for localized prostate cancer consists of androgen deprivation therapies (ADTs), which typically inhibit androgen production and the androgen receptor (AR). Though initially effective, a subset of patients will develop resistance to ADTs and the tumors will transition to castration-resistant prostate cancer (CRPC). Second generation hormonal therapies such as abiraterone acetate and enzalutamide are typically given to men with CRPC. However, these treatments are not curative and typically prolong survival only by a few months. Several resistance mechanisms contribute to this lack of efficacy such as the emergence of AR mutations, AR amplification, lineage plasticity, AR splice variants (AR-Vs) and increased kinase signaling. Having identified SRC kinase as a key tyrosine kinase enriched in CRPC patient tumors from our previous work, we evaluated whether inhibition of SRC kinase synergizes with enzalutamide or chemotherapy in several prostate cancer cell lines expressing variable AR isoforms. We observed robust synergy between the SRC kinase inhibitor, saracatinib, and enzalutamide, in the AR-FL+/AR-V+ CRPC cell lines, LNCaP95 and 22Rv1. We also observed that saracatinib significantly decreases AR Y 534 phosphorylation, a key SRC kinase substrate residue, on AR-FL and AR-Vs, along with the AR regulome, supporting key mechanisms of synergy with enzalutamide. Lastly, we also found that the saracatinib-enzalutamide combination reduced DNA replication compared to the saracatinib-docetaxel combination, resulting in marked increased apoptosis. By elucidating this combination strategy, we provide pre-clinical data that suggests combining SRC kinase inhibitors with enzalutamide in select patients that express both AR-FL and AR-Vs.

10.
Molecules ; 28(7)2023 Mar 24.
Artículo en Inglés | MEDLINE | ID: mdl-37049674

RESUMEN

Multi-drug resistance to antibiotics represents a growing challenge in treating infectious diseases. Outside the hospital, bacteria with the multi-drug resistance (MDR) phenotype have an increased prevalence in anthropized environments, thus implying that chemical stresses, such as metals, hydrocarbons, organic compounds, etc., are the source of such resistance. There is a developing hypothesis regarding the role of metal contamination in terrestrial and aquatic environments as a selective agent in the proliferation of antibiotic resistance caused by the co-selection of antibiotic and metal resistance genes carried by transmissible plasmids and/or associated with transposons. Efflux pumps are also known to be involved in either antibiotic or metal resistance. In order to deal with these situations, microorganisms use an effective strategy that includes a range of expressions based on biochemical and genetic mechanisms. The data from numerous studies suggest that heavy metal contamination could affect the dissemination of antibiotic-resistant genes. Environmental pollution caused by anthropogenic activities could lead to mutagenesis based on the synergy between antibiotic efficacy and the acquired resistance mechanism under stressors. Moreover, the acquired resistance includes plasmid-encoded specific efflux pumps. Soil microbiomes have been reported as reservoirs of resistance genes that are available for exchange with pathogenic bacteria. Importantly, metal-contaminated soil is a selective agent that proliferates antibiotic resistance through efflux pumps. Thus, the use of multi-drug efflux pump inhibitors (EPIs) originating from natural plants or synthetic compounds is a promising approach for restoring the efficacy of existing antibiotics, even though they face a lot of challenges.


Asunto(s)
Bacterias , Metales Pesados , Farmacorresistencia Microbiana , Bacterias/genética , Bacterias/metabolismo , Plásmidos/genética , Metales Pesados/farmacología , Antibacterianos/farmacología , Antibacterianos/metabolismo , Farmacorresistencia Bacteriana Múltiple/genética
11.
Antibiotics (Basel) ; 12(2)2023 Feb 20.
Artículo en Inglés | MEDLINE | ID: mdl-36830331

RESUMEN

During the process of adapting to metal contamination, plants produce secondary metabolites that have the potential to modulate multidrug-resistant (MDR) phenotypes; this is achieved by inhibiting the activity of efflux pumps to reduce the minimum inhibitory concentrations (MICs) of antimicrobial substrates. Our study evaluated the effect of secondary metabolites of belowground parts of Pteris vittata L. and Fallopia japonica, two metal-tolerant plants from northern Vietnam, on six antibiotic-resistant Stenotrophomonas maltophilia strains possessing efflux pump resistance mechanisms that were isolated from soil and clinical samples. The chemical composition of aqueous and dichloromethane (DCM) fractions extracted from P. vittata and F. japonica was determined using UHPLC-DAD-ESI/QTOF analysis. The antibacterial and efflux pump inhibitory activities of the four fractions were evaluated for the six strains (K279a, 0366, BurA1, BurE1, PierC1, and 502) using a microdilution assay at fraction concentrations of 62.5, 125, and 250 µg/mL. The DCM fraction of F. japonica exhibited remarkable antibacterial activity against strain 0366, with a MIC of 31.25 µg/mL. Furthermore, this fraction also significantly decreased gentamicin MIC: four-fold and eight-fold reductions for BurA1 and BurE1 strains, respectively (when tested at 250 µg/mL), and two-fold and eight-fold reductions for K279a and BurE1 strains, respectively (when tested at 125 µg/mL). Pure emodin, the main component identified in the DCM fraction of F. japonica, and sennidine A&B only reduced by half the MIC of gentamicin (when tested at 30 µg/mL). Our results suggest that the DCM fraction components of F. japonica underground parts may be potential candidates for new bacterial efflux pump inhibitors (EPIs).

12.
Nucleic Acids Res ; 51(5): 2215-2237, 2023 03 21.
Artículo en Inglés | MEDLINE | ID: mdl-36794853

RESUMEN

PARP1 is a DNA-dependent ADP-Ribose transferase with ADP-ribosylation activity that is triggered by DNA breaks and non-B DNA structures to mediate their resolution. PARP1 was also recently identified as a component of the R-loop-associated protein-protein interaction network, suggesting a potential role for PARP1 in resolving this structure. R-loops are three-stranded nucleic acid structures that consist of a RNA-DNA hybrid and a displaced non-template DNA strand. R-loops are involved in crucial physiological processes but can also be a source of genome instability if persistently unresolved. In this study, we demonstrate that PARP1 binds R-loops in vitro and associates with R-loop formation sites in cells which activates its ADP-ribosylation activity. Conversely, PARP1 inhibition or genetic depletion causes an accumulation of unresolved R-loops which promotes genomic instability. Our study reveals that PARP1 is a novel sensor for R-loops and highlights that PARP1 is a suppressor of R-loop-associated genomic instability.


Asunto(s)
Inestabilidad Genómica , Poli(ADP-Ribosa) Polimerasa-1 , Estructuras R-Loop , Humanos , ADN/química , Reparación del ADN , Poli(ADP-Ribosa) Polimerasa-1/genética , Poli(ADP-Ribosa) Polimerasa-1/metabolismo , ARN/química
13.
Chem Res Toxicol ; 35(11): 2025-2036, 2022 11 21.
Artículo en Inglés | MEDLINE | ID: mdl-36356054

RESUMEN

4-(Methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) is a potent lung carcinogen present in tobacco products, and exposure to it is likely one of the factors contributing to the development of lung cancer in cigarette smokers. To exert its carcinogenic effects, NNK must be metabolically activated into highly reactive species generating a wide spectrum of DNA damage. We have identified a new class of DNA adducts, DNA-RNA cross-links found for the first time in NNK-treated mice lung DNA using our improved high-resolution accurate mass segmented full scan data-dependent neutral loss MS3 screening strategy. The levels of these DNA-RNA cross-links were found to be significantly higher in NNK-treated mice compared to the corresponding controls, which is consistent with higher levels of formaldehyde due to NNK metabolism as compared to endogenous levels. We hypothesize that this DNA-RNA cross-linking occurs through reaction with NNK-generated formaldehyde and speculate that this phenomenon has broad implications for NNK-induced carcinogenesis. The structures of these cross-links were characterized using high-resolution LC-MS2 and LC-MS3 accurate mass spectral analysis and comparison to a newly synthesized standard. Taken together, our data demonstrate a previously unknown link between DNA-RNA cross-link adducts and NNK and provide a unique opportunity to further investigate how these novel NNK-derived DNA-RNA cross-links contribute to carcinogenesis in the future.


Asunto(s)
Carcinogénesis , ARN , Ratones , Animales , Carcinogénesis/inducido químicamente , Transformación Celular Neoplásica , ADN , Formaldehído/toxicidad , Ratones Endogámicos , Pulmón
14.
J Mol Graph Model ; 111: 108103, 2022 03.
Artículo en Inglés | MEDLINE | ID: mdl-34959149

RESUMEN

Proteins are essential to nearly all cellular mechanism and the effectors of the cells activities. As such, they often interact through their surface with other proteins or other cellular ligands such as ions or organic molecules. The evolution generates plenty of different proteins, with unique abilities, but also proteins with related functions hence similar 3D surface properties (shape, physico-chemical properties, …). The protein surfaces are therefore of primary importance for their activity. In the present work, we assess the ability of different methods to detect such similarities based on the geometry of the protein surfaces (described as 3D meshes), using either their shape only, or their shape and the electrostatic potential (a biologically relevant property of proteins surface). Five different groups participated in this contest using the shape-only dataset, and one group extended its pre-existing method to handle the electrostatic potential. Our comparative study reveals both the ability of the methods to detect related proteins and their difficulties to distinguish between highly related proteins. Our study allows also to analyze the putative influence of electrostatic information in addition to the one of protein shapes alone. Finally, the discussion permits to expose the results with respect to ones obtained in the previous contests for the extended method. The source codes of each presented method have been made available online.


Asunto(s)
Proteínas , Ligandos , Modelos Moleculares , Dominios Proteicos , Electricidad Estática
15.
J Math Biol ; 83(2): 22, 2021 08 03.
Artículo en Inglés | MEDLINE | ID: mdl-34345961

RESUMEN

Motivated by our study of infiltrating dynamics of immune cells into tumors, we propose a stochastic model in terms of Ito stochastic differential equations to study how two parameters, the chemoattractant production rate and the chemotactic coefficient, influence immune cell migration and how these parameters distinguish two types of gliomas. We conduct a detailed analysis of the stochastic model and its deterministic counterpart. The deterministic model can differentiate two types of gliomas according to the range of the chemoattractant production rate as two equilibrium solutions, while the stochastic model also can differentiate two types of gliomas according to the ranges of the chemoattractant production rate and chemotactic coefficient with thresholds as one non-zero ergodic invariant measure and one weak persistent state when the noise intensities are small. When the noise intensities are large comparing with the chemotactic coefficient, there is only one type of glioma that corresponds to a non-zero ergodic invariant measure. Using our experimental data, numerical simulations are carried out to demonstrate properties of our models, and we give medical interpretations and implications for our analytical results and numerical simulations. This study also confirms some of our results about IDH gliomas.


Asunto(s)
Glioma , Humanos , Procesos Estocásticos
16.
Sci Rep ; 11(1): 8345, 2021 Apr 16.
Artículo en Inglés | MEDLINE | ID: mdl-33863930

RESUMEN

This work presents experiments about the transmission of electrons with an energy of around 15 keV with beam currents up to 20 µA through macroscopic glass capillaries. A systematic study was conducted to experimentally investigate the transmission of electrons through borosilicate glass capillaries with curve angles of 90°, 180°, 270° and 360° for the first time. The focus of the work was to identify the conditions under which the injected electron current is transmitted through the capillary. It was also shown that the transmission process in the macroscopic capillaries can be optically observed by cathodoluminescence-the interaction of electrons with the capillary surface causes locally a blue glow. Different distinctive "glow states" were observed and are found to correlate with different states of electron transmission.

17.
Nat Prod Res ; 35(7): 1134-1138, 2021 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-31322428

RESUMEN

The MeOH extract of the Vietnamese octocoral Dendronephthya mucronata afforded four bicyclic lactones (1-4), including three new compounds namely dendronephthyones A-C (1-3), after subjecting it on various chromatographic separations. The structures of the isolated compounds were established by spectroscopic experiments including 1D, 2D NMR, CD and HR-QTOF-MS. In addition, compounds 1-4 were found to exhibit selective cytotoxicity against the HeLa human cancer cell line with IC50 values of 32.48 ± 2.15, 30.12 ± 1.86, 35.14 ± 1.57 and 14.45 ± 1.34 µM, respectively.


Asunto(s)
Antozoos/química , Lactonas/aislamiento & purificación , Animales , Espectroscopía de Resonancia Magnética con Carbono-13 , Muerte Celular/efectos de los fármacos , Línea Celular Tumoral , Humanos , Lactonas/química , Lactonas/farmacología , Espectroscopía de Protones por Resonancia Magnética
18.
J Asian Nat Prod Res ; 23(5): 491-497, 2021 May.
Artículo en Inglés | MEDLINE | ID: mdl-32212861

RESUMEN

In our search for cytotoxic constituents from Vietnamese plants, the methanolic extract of Isotrema tadungense was found to exhibit significant cytotoxic effect. Subsequent phytochemical investigation of ethyl acetate fractions of this plant led to isolation of 11 compounds including one new arylbenzofuran rhamnoside namely aristolochiaside (1), two aristololactams (2 and 3), three lignanamides (4-6) and five phenolic amides (7-11). Their structures were elucidated by 1 D and 2 D NMR and HR-QTOF-MS experiments. Among the isolated compounds, aristolochiaside (1), aristolactam AIIIa (2) and N-trans-sinapoyltyramine (10) exhibited strong and selective cytotoxicity on the HeLa human cancer cell line with IC50 values of 7.59 ± 1.03, 8.51 ± 1.73 and 9.77 ± 1.25 µM, respectively.[Formula: see text].


Asunto(s)
Antineoplásicos , Amidas , Antineoplásicos/farmacología , Células HeLa , Humanos , Estructura Molecular , Extractos Vegetales
19.
Mol Cell ; 77(3): 514-527.e4, 2020 02 06.
Artículo en Inglés | MEDLINE | ID: mdl-31708417

RESUMEN

R loops arising during transcription induce genomic instability, but how cells respond to the R loop-associated genomic stress is still poorly understood. Here, we show that cells harboring high levels of R loops rely on the ATR kinase for survival. In response to aberrant R loop accumulation, the ataxia telangiectasia and Rad3-related (ATR)-Chk1 pathway is activated by R loop-induced reversed replication forks. In contrast to the activation of ATR by replication inhibitors, R loop-induced ATR activation requires the MUS81 endonuclease. ATR protects the genome from R loops by suppressing transcription-replication collisions, promoting replication fork recovery, and enforcing a G2/M cell-cycle arrest. Furthermore, ATR prevents excessive cleavage of reversed forks by MUS81, revealing a MUS81-triggered and ATR-mediated feedback loop that fine-tunes MUS81 activity at replication forks. These results suggest that ATR is a key sensor and suppressor of R loop-induced genomic instability, uncovering a signaling circuitry that safeguards the genome against R loops.


Asunto(s)
Proteínas de la Ataxia Telangiectasia Mutada/metabolismo , Proteínas de Unión al ADN/metabolismo , Endonucleasas/metabolismo , Estructuras R-Loop/genética , Proteínas de la Ataxia Telangiectasia Mutada/fisiología , Proteínas de Ciclo Celular/metabolismo , Quinasa 1 Reguladora del Ciclo Celular (Checkpoint 1)/genética , Daño del ADN , Reparación del ADN , Replicación del ADN/genética , Replicación del ADN/fisiología , Proteínas de Unión al ADN/genética , Endonucleasas/genética , Inestabilidad Genómica/fisiología , Células HeLa , Humanos , Fosforilación , Proteínas Quinasas/metabolismo , Transducción de Señal
20.
Molecules ; 24(21)2019 Oct 24.
Artículo en Inglés | MEDLINE | ID: mdl-31652901

RESUMEN

Marine microorganisms are an invaluable source of novel active secondary metabolites possessing various biological activities. In this study, the extraction and isolation of the marine sediment Penicillium species collected in Vietnam yielded ten secondary metabolites, including sporogen AO-1 (1), 3-indolecarbaldehyde (2), 2-[(5-methyl-1,4-dioxan-2-yl)methoxy]ethanol (3), 2-[(2R-hydroxypropanoyl)amino]benzamide (4), 4-hydroxybenzandehyde (5), chrysogine (6), 3-acetyl-4-hydroxycinnoline (7), acid 1H-indole-3-acetic (8), cyclo (Tyr-Trp) (9), and 2',3'-dihydrosorbicillin (10). Their structures were identified by the analysis of 1D and 2D NMR data. Among the isolated compounds, 2-[(5-methyl-1,4-dioxan-2-yl)methoxy]ethanol (3) showed a strong inhibitory effect against Enterococcus faecalis with a minimum inhibitory concentration value of 32 µg/mL. Both 2-[(2R-hydroxypropanoyl)amino]benzamide (4) and 4-hydroxybenzandehyde (5) selectively inhibited E. coli with minimum inhibitory concentration values of 16 and 8 µg/mL, respectively. 2',3'-Dihydrosorbicillin (10) potentially inhibited α-glucosidase activity at a concentration of 2.0 mM (66.31%).


Asunto(s)
Antibacterianos , Organismos Acuáticos , Enterococcus faecalis/crecimiento & desarrollo , Penicillium , Antibacterianos/química , Antibacterianos/metabolismo , Antibacterianos/farmacología , Organismos Acuáticos/química , Organismos Acuáticos/metabolismo , Estructura Molecular , Penicillium/química , Penicillium/metabolismo , Vietnam
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