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1.
Nature ; 625(7996): 822-831, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-37783228

RESUMEN

Argonaute (Ago) proteins mediate RNA- or DNA-guided inhibition of nucleic acids1,2. Although the mechanisms used by eukaryotic Ago proteins and long prokaryotic Ago proteins (pAgos) are known, that used by short pAgos remains elusive. Here we determined the cryo-electron microscopy structures of a short pAgo and the associated TIR-APAZ proteins (SPARTA) from Crenotalea thermophila (Crt): a free-state Crt-SPARTA; a guide RNA-target DNA-loaded Crt-SPARTA; two Crt-SPARTA dimers with distinct TIR organization; and a Crt-SPARTA tetramer. These structures reveal that Crt-SPARTA is composed of a bilobal-fold Ago lobe that connects with a TIR lobe. Whereas the Crt-Ago contains a MID and a PIWI domain, Crt-TIR-APAZ has a TIR domain, an N-like domain, a linker domain and a trigger domain. The bound RNA-DNA duplex adopts a B-form conformation that is recognized by base-specific contacts. Nucleic acid binding causes conformational changes because the trigger domain acts as a 'roadblock' that prevents the guide RNA 5' ends and the target DNA 3' ends from reaching their canonical pockets; this disorders the MID domain and promotes Crt-SPARTA dimerization. Two RNA-DNA-loaded Crt-SPARTA dimers form a tetramer through their TIR domains. Four Crt-TIR domains assemble into two parallel head-to-tail-organized TIR dimers, indicating an NADase-active conformation, which is supported by our mutagenesis study. Our results reveal the structural basis of short-pAgo-mediated defence against invading nucleic acids, and provide insights for optimizing the detection of SPARTA-based programmable DNA sequences.


Asunto(s)
Proteínas Argonautas , Microscopía por Crioelectrón , NAD+ Nucleosidasa , Ácidos Nucleicos , Proteínas Argonautas/química , Proteínas Argonautas/metabolismo , Proteínas Argonautas/ultraestructura , ADN/química , ADN/genética , ADN/metabolismo , ADN/ultraestructura , Activación Enzimática , NAD+ Nucleosidasa/química , NAD+ Nucleosidasa/genética , NAD+ Nucleosidasa/metabolismo , NAD+ Nucleosidasa/ultraestructura , Conformación de Ácido Nucleico , Ácidos Nucleicos/metabolismo , Conformación Proteica , ARN Guía de Sistemas CRISPR-Cas , Mutagénesis
2.
Mol Cell ; 81(6): 1200-1215.e9, 2021 03 18.
Artículo en Inglés | MEDLINE | ID: mdl-33639093

RESUMEN

Ribosome biogenesis is a fundamental multi-step cellular process that culminates in the formation of ribosomal subunits, whose production and modification are regulated by numerous biogenesis factors. In this study, we analyze physiologic prokaryotic ribosome biogenesis by isolating bona fide pre-50S subunits from an Escherichia coli strain with the biogenesis factor ObgE, affinity tagged at its native gene locus. Our integrative structural approach reveals a network of interacting biogenesis factors consisting of YjgA, RluD, RsfS, and ObgE on the immature pre-50S subunit. In addition, our study provides mechanistic insight into how the GTPase ObgE, in concert with other biogenesis factors, facilitates the maturation of the 50S functional core and reveals both conserved and divergent evolutionary features of ribosome biogenesis between prokaryotes and eukaryotes.


Asunto(s)
Proteínas de Escherichia coli , Evolución Molecular , Sitios Genéticos , Hidroliasas , Proteínas de Unión al GTP Monoméricas , Subunidades Ribosómicas Grandes Bacterianas , Proteínas de Escherichia coli/química , Proteínas de Escherichia coli/genética , Proteínas de Escherichia coli/metabolismo , Hidroliasas/química , Hidroliasas/genética , Hidroliasas/metabolismo , Proteínas de Unión al GTP Monoméricas/química , Proteínas de Unión al GTP Monoméricas/genética , Proteínas de Unión al GTP Monoméricas/metabolismo , Subunidades Ribosómicas Grandes Bacterianas/química , Subunidades Ribosómicas Grandes Bacterianas/genética , Subunidades Ribosómicas Grandes Bacterianas/metabolismo
3.
Cell ; 153(6): 1327-39, 2013 Jun 06.
Artículo en Inglés | MEDLINE | ID: mdl-23746844

RESUMEN

The transcription factor HIF1A is a key mediator of the cellular response to hypoxia. Despite the importance of HIF1A in homeostasis and various pathologies, little is known about how it regulates RNA polymerase II (RNAPII). We report here that HIF1A employs a specific variant of the Mediator complex to stimulate RNAPII elongation. The Mediator-associated kinase CDK8, but not the paralog CDK19, is required for induction of many HIF1A target genes. HIF1A induces binding of CDK8-Mediator and the super elongation complex (SEC), containing AFF4 and CDK9, to alleviate RNAPII pausing. CDK8 is dispensable for HIF1A chromatin binding and histone acetylation, but it is essential for binding of SEC and RNAPII elongation. Global analysis of active RNAPII reveals that hypoxia-inducible genes are paused and active prior to their induction. Our results provide a mechanistic link between HIF1A and CDK8, two potent oncogenes, in the cellular response to hypoxia.


Asunto(s)
Hipoxia de la Célula , Quinasa 8 Dependiente de Ciclina/metabolismo , Subunidad alfa del Factor 1 Inducible por Hipoxia/metabolismo , Complejo Mediador/metabolismo , Neoplasias/metabolismo , ARN Polimerasa II/metabolismo , Elongación de la Transcripción Genética , Acetilación , Línea Celular Tumoral , Quinasa 8 Dependiente de Ciclina/química , Quinasas Ciclina-Dependientes/metabolismo , Células HeLa , Histonas/metabolismo , Humanos
4.
Mol Cell ; 79(5): 824-835.e5, 2020 09 03.
Artículo en Inglés | MEDLINE | ID: mdl-32649882

RESUMEN

DNA-protein crosslinks (DPCs) are highly toxic DNA lesions that threaten genomic integrity. Recent findings highlight that SPRTN, a specialized DNA-dependent metalloprotease, is a central player in proteolytic cleavage of DPCs. Previous studies suggest that SPRTN deubiquitination is important for its chromatin association and activation. However, the regulation and consequences of SPRTN deubiquitination remain unclear. Here we report that, in response to DPC induction, the deubiquitinase VCPIP1/VCIP135 is phosphorylated and activated by ATM/ATR. VCPIP1, in turn, deubiquitinates SPRTN and promotes its chromatin relocalization. Deubiquitination of SPRTN is required for its subsequent acetylation, which promotes SPRTN relocation to the site of chromatin damage. Furthermore, Vcpip1 knockout mice are prone to genomic instability and premature aging. We propose a model where two sequential post-translational modifications (PTMs) regulate SPRTN chromatin accessibility to repair DPCs and maintain genomic stability and a healthy lifespan.


Asunto(s)
Envejecimiento/genética , Reparación del ADN , Proteínas de Unión al ADN/metabolismo , Acetilación , Envejecimiento/metabolismo , Animales , Línea Celular , Daño del ADN , Proteínas de Unión al ADN/genética , Enzimas Desubicuitinizantes/metabolismo , Endopeptidasas/metabolismo , Femenino , Inestabilidad Genómica , Células HEK293 , Humanos , Masculino , Ratones Endogámicos C57BL , Ratones Noqueados , Fosforilación , Dominios Proteicos , Procesamiento Proteico-Postraduccional , Ubiquitinación
5.
Mol Cell ; 74(6): 1215-1226.e4, 2019 06 20.
Artículo en Inglés | MEDLINE | ID: mdl-31053471

RESUMEN

Programmed death ligand 1 (PD-L1, also called B7-H1) is an immune checkpoint protein that inhibits immune function through its binding of the programmed cell death protein 1 (PD-1) receptor. Clinically approved antibodies block extracellular PD-1 and PD-L1 binding, yet the role of intracellular PD-L1 in cancer remains poorly understood. Here, we discovered that intracellular PD-L1 acts as an RNA binding protein that regulates the mRNA stability of NBS1, BRCA1, and other DNA damage-related genes. Through competition with the RNA exosome, intracellular PD-L1 protects targeted RNAs from degradation, thereby increasing cellular resistance to DNA damage. RNA immunoprecipitation and RNA-seq experiments demonstrated that PD-L1 regulates RNA stability genome-wide. Furthermore, we developed a PD-L1 antibody, H1A, which abrogates the interaction of PD-L1 with CMTM6, thereby promoting PD-L1 degradation. Intracellular PD-L1 may be a potential therapeutic target to enhance the efficacy of radiotherapy and chemotherapy in cancer through the inhibition of DNA damage response and repair.


Asunto(s)
Antígeno B7-H1/genética , Reparación del ADN , ADN de Neoplasias/genética , Complejo Multienzimático de Ribonucleasas del Exosoma/genética , Regulación Neoplásica de la Expresión Génica , Receptor de Muerte Celular Programada 1/genética , Animales , Antineoplásicos/farmacología , Antígeno B7-H1/antagonistas & inhibidores , Antígeno B7-H1/metabolismo , Proteína BRCA1/genética , Proteína BRCA1/metabolismo , Proteínas de Ciclo Celular/genética , Proteínas de Ciclo Celular/metabolismo , Línea Celular Tumoral , Cisplatino/farmacología , Daño del ADN , ADN de Neoplasias/metabolismo , Complejo Multienzimático de Ribonucleasas del Exosoma/metabolismo , Rayos gamma/uso terapéutico , Células HCT116 , Células HeLa , Humanos , Proteínas con Dominio MARVEL , Proteínas de la Membrana/genética , Proteínas de la Membrana/metabolismo , Ratones , Proteínas de la Mielina , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Receptor de Muerte Celular Programada 1/antagonistas & inhibidores , Receptor de Muerte Celular Programada 1/metabolismo , Proteolisis/efectos de los fármacos , Proteolisis/efectos de la radiación , Estabilidad del ARN/efectos de los fármacos , Estabilidad del ARN/efectos de la radiación , ARN Interferente Pequeño/genética , ARN Interferente Pequeño/metabolismo , Ensayos Antitumor por Modelo de Xenoinjerto
6.
Mol Cell ; 70(5): 881-893.e3, 2018 06 07.
Artículo en Inglés | MEDLINE | ID: mdl-29883607

RESUMEN

The assembly of ribosomal subunits is an essential prerequisite for protein biosynthesis in all domains of life. Although biochemical and biophysical approaches have advanced our understanding of ribosome assembly, our mechanistic comprehension of this process is still limited. Here, we perform an in vitro reconstitution of the Escherichia coli 50S ribosomal subunit. Late reconstitution products were subjected to high-resolution cryo-electron microscopy and multiparticle refinement analysis to reconstruct five distinct precursors of the 50S subunit with 4.3-3.8 Å resolution. These assembly intermediates define a progressive maturation pathway culminating in a late assembly particle, whose structure is more than 96% identical to a mature 50S subunit. Our structures monitor the formation and stabilization of structural elements in a nascent particle in unprecedented detail and identify the maturation of the rRNA-based peptidyl transferase center as the final critical step along the 50S assembly pathway.


Asunto(s)
Escherichia coli/metabolismo , ARN Bacteriano/metabolismo , ARN Ribosómico 23S/metabolismo , Subunidades Ribosómicas Grandes Bacterianas/metabolismo , Microscopía por Crioelectrón , Escherichia coli/genética , Escherichia coli/ultraestructura , Modelos Moleculares , Conformación de Ácido Nucleico , Conformación Proteica , ARN Bacteriano/genética , ARN Bacteriano/ultraestructura , ARN Ribosómico 23S/genética , ARN Ribosómico 23S/ultraestructura , Subunidades Ribosómicas Grandes Bacterianas/genética , Subunidades Ribosómicas Grandes Bacterianas/ultraestructura , Relación Estructura-Actividad
7.
Nucleic Acids Res ; 51(13): 7053-7070, 2023 07 21.
Artículo en Inglés | MEDLINE | ID: mdl-37293979

RESUMEN

Schlafen11 (SLFN11) is one of the most studied Schlafen proteins that plays vital roles in cancer therapy and virus-host interactions. Herein, we determined the crystal structure of the Sus scrofa SLFN11 N-terminal domain (NTD) to 2.69 Å resolution. sSLFN11-NTD is a pincer-shaped molecule that shares an overall fold with other SLFN-NTDs but exhibits distinct biochemical characteristics. sSLFN11-NTD is a potent RNase cleaving type I and II tRNAs and rRNAs, and with preference to type II tRNAs. Consistent with the codon usage-based translation suppression activity of SLFN11, sSLFN11-NTD cleaves synonymous serine and leucine tRNAs with different efficiencies in vitro. Mutational analysis revealed key determinates of sSLFN11-NTD nucleolytic activity, including the Connection-loop, active site, and key residues essential for substrate recognition, among which E42 constrains sSLFN11-NTD RNase activity, and all nonconservative mutations of E42 stimulated RNase activities. sSLFN11 inhibited the translation of proteins with a low codon adaptation index in cells, which mainly dependent on the RNase activity of the NTD because E42A enhanced the inhibitory effect, but E209A abolished inhibition. Our findings provide structural characterization of an important SLFN11 protein and expand our understanding of the Schlafen family.


Asunto(s)
Proteínas Nucleares , ARN de Transferencia , Ribonucleasas , Dominio Catalítico , Mutación , Ribonucleasas/metabolismo , ARN de Transferencia/genética , ARN de Transferencia/metabolismo , Sus scrofa , Proteínas Nucleares/metabolismo , Animales
8.
Breast Cancer Res ; 26(1): 75, 2024 May 08.
Artículo en Inglés | MEDLINE | ID: mdl-38720366

RESUMEN

BACKGROUND: Tumor-associated macrophages (TAMs) are a prominent immune subpopulation in the tumor microenvironment that could potentially serve as therapeutic targets for breast cancer. Thus, it is important to characterize this cell population across different tumor subtypes including patterns of association with demographic and prognostic factors, and breast cancer outcomes. METHODS: We investigated CD163+ macrophages in relation to clinicopathologic variables and breast cancer outcomes in the Women's Circle of Health Study and Women's Circle of Health Follow-up Study populations of predominantly Black women with breast cancer. We evaluated 611 invasive breast tumor samples (507 from Black women, 104 from White women) with immunohistochemical staining of tissue microarray slides followed by digital image analysis. Multivariable Cox proportional hazards models were used to estimate hazard ratios for overall survival (OS) and breast cancer-specific survival (BCSS) for 546 cases with available survival data (median follow-up time 9.68 years (IQR: 7.43-12.33). RESULTS: Women with triple-negative breast cancer showed significantly improved OS in relation to increased levels of tumor-infiltrating CD163+ macrophages in age-adjusted (Q3 vs. Q1: HR = 0.36; 95% CI 0.16-0.83) and fully adjusted models (Q3 vs. Q1: HR = 0.30; 95% CI 0.12-0.73). A similar, but non-statistically significant, association was observed for BCSS. Macrophage infiltration in luminal and HER2+ tumors was not associated with OS or BCSS. In a multivariate regression model that adjusted for age, subtype, grade, and tumor size, there was no significant difference in CD163+ macrophage density between Black and White women (RR = 0.88; 95% CI 0.71-1.10). CONCLUSIONS: In contrast to previous studies, we observed that higher densities of CD163+ macrophages are independently associated with improved OS and BCSS in women with invasive triple-negative breast cancer. Trial registration Not applicable.


Asunto(s)
Antígenos CD , Antígenos de Diferenciación Mielomonocítica , Receptores de Superficie Celular , Neoplasias de la Mama Triple Negativas , Microambiente Tumoral , Humanos , Femenino , Microambiente Tumoral/inmunología , Antígenos de Diferenciación Mielomonocítica/metabolismo , Antígenos CD/metabolismo , Persona de Mediana Edad , Receptores de Superficie Celular/metabolismo , Neoplasias de la Mama Triple Negativas/mortalidad , Neoplasias de la Mama Triple Negativas/patología , Neoplasias de la Mama Triple Negativas/inmunología , Neoplasias de la Mama Triple Negativas/metabolismo , Estudios de Seguimiento , Pronóstico , Adulto , Macrófagos Asociados a Tumores/metabolismo , Macrófagos Asociados a Tumores/inmunología , Macrófagos/metabolismo , Macrófagos/inmunología , Macrófagos/patología , Anciano , Biomarcadores de Tumor/metabolismo , Modelos de Riesgos Proporcionales
9.
Am J Epidemiol ; 2024 May 21.
Artículo en Inglés | MEDLINE | ID: mdl-38775277

RESUMEN

BACKGROUND: Limited estimates exist on risk factors for epithelial ovarian cancer (EOC) in Asian, Hispanic, and Native Hawaiian/Pacific Islander (NHPI) women. METHODS: Participants included 1734 Asian (785 cases, 949 controls), 266 NHPI (99 cases, 167 controls), 1149 Hispanic (505 cases, 644 controls), and 24,189 White (9,981 cases, 14,208 controls) women from 11 studies in the Ovarian Cancer Association Consortium. Logistic regression models estimated odds ratios (ORs) and 95% confidence intervals (CIs) for risk associations by race and ethnicity. RESULTS: Heterogeneity in EOC risk associations by race and ethnicity (p ≤ 0.02) was observed for oral contraceptive (OC) use, parity, tubal ligation and smoking. We observed inverse associations with EOC risk for OC use and parity across all groups; associations were strongest in NHPI and Asian women. The inverse association for tubal ligation with risk was most pronounced for NHPI participants (OR=0.25, 95% CI 0.13-0.48), versus Asian and White participants, respectively (OR=0.68, 95% CI 0.51-0.90; OR=0.78, 95% CI 0.73-0.85). CONCLUSIONS: Differences in EOC risk factor associations were observed across racial and ethnic groups, which could in part be due to varying prevalence of EOC histotypes. Inclusion of greater diversity in future studies is essential to inform prevention strategies.

10.
Hum Genet ; 143(3): 331-342, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38478153

RESUMEN

Accurate discrimination of pathogenic and nonpathogenic variation remains an enormous challenge in clinical genetic testing of inherited retinal diseases (IRDs) patients. Computational methods for predicting variant pathogenicity are the main solutions for this dilemma. The majority of the state-of-the-art variant pathogenicity prediction tools disregard the differences in characteristics among different genes and treat all types of mutations equally. Since missense variants are the most common type of variation in the coding region of the human genome, we developed a novel missense mutation pathogenicity prediction tool, named Prediction of Deleterious Missense Mutation for IRDs (PdmIRD) in this study. PdmIRD was tailored for IRDs-related genes and constructed with the conditional random forest model. Population frequencies and a newly available prediction tool were incorporated into PdmIRD to improve the performance of the model. The evaluation of PdmIRD demonstrated its superior performance over nonspecific tools (areas under the curves, 0.984 and 0.910) and an existing eye abnormalities-specific tool (areas under the curves, 0.975 and 0.891). We also demonstrated the submodel that used a smaller gene panel further slightly improved performance. Our study provides evidence that a disease-specific model can enhance the prediction of missense mutation pathogenicity, especially when new and important features are considered. Additionally, this study provides guidance for exploring the characteristics and functions of the mutated proteins in a greater number of Mendelian disorders.


Asunto(s)
Mutación Missense , Enfermedades de la Retina , Humanos , Biología Computacional/métodos , Predisposición Genética a la Enfermedad , Pruebas Genéticas/métodos , Enfermedades de la Retina/diagnóstico , Enfermedades de la Retina/genética
11.
Small ; 20(1): e2304806, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-37649194

RESUMEN

The sluggish kinetics in Ni-rich cathodes at subzero temperatures causes decreased specific capacity and poor rate capability, resulting in slow and unstable charge storage. So far, the driving force of this phenomenon remains a mystery. Herein, with the help of in-situ X-ray diffraction and time of flight secondary ion mass spectrometry techniques, the continuous accumulation of both the cathode electrolyte interphase (CEI) film formation and the incomplete structure evolution during cycling under subzero temperature are proposed. It is presented that excessively uniform and thick CEI film generated at subzero temperatures would block the diffusion of Li+ -ions, resulting in incomplete phase evolution and clear charge potential delay. The incomplete phase evolution throughout the Li+ -ion intercalation/de-intercalation processes would further cause low depth of discharge and poor electrochemical reversibility with low initial Coulombic efficiency, as well. In addition, the formation of the thick and uniform CEI film would also consume Li+ -ions during the charging process. This discovery highlights the effects of the CEI film formation behavior and incomplete phase evolution in restricting electrochemical kinetics under subzero temperatures, which the authors believe would promote the further application of the Ni-rich cathodes.

12.
PLoS Pathog ; 18(2): e1009862, 2022 02.
Artículo en Inglés | MEDLINE | ID: mdl-35134095

RESUMEN

There is a growing appreciation for the idea that bacterial utilization of host-derived lipids, including cholesterol, supports Mycobacterium tuberculosis (Mtb) pathogenesis. This has generated interest in identifying novel antibiotics that can disrupt cholesterol utilization by Mtb in vivo. Here we identify a novel small molecule agonist (V-59) of the Mtb adenylyl cyclase Rv1625c, which stimulates 3', 5'-cyclic adenosine monophosphate (cAMP) synthesis and inhibits cholesterol utilization by Mtb. Similarly, using a complementary genetic approach that induces bacterial cAMP synthesis independent of Rv1625c, we demonstrate that inducing cAMP synthesis is sufficient to inhibit cholesterol utilization in Mtb. Although the physiological roles of individual adenylyl cyclase enzymes in Mtb are largely unknown, here we demonstrate that the transmembrane region of Rv1625c is required during cholesterol metabolism. Finally, the pharmacokinetic properties of Rv1625c agonists have been optimized, producing an orally-available Rv1625c agonist that impairs Mtb pathogenesis in infected mice. Collectively, this work demonstrates a role for Rv1625c and cAMP signaling in controlling cholesterol metabolism in Mtb and establishes that cAMP signaling can be pharmacologically manipulated for the development of new antibiotic strategies.


Asunto(s)
Adenilil Ciclasas/metabolismo , Colesterol/metabolismo , AMP Cíclico/metabolismo , Mycobacterium tuberculosis/genética , Animales , Proteínas Bacterianas/metabolismo , Ratones Endogámicos BALB C , Transducción de Señal/fisiología , Activación Transcripcional/fisiología
13.
New Phytol ; 2024 Jun 19.
Artículo en Inglés | MEDLINE | ID: mdl-38898642

RESUMEN

Drought-induced xylem embolism is a primary cause of plant mortality. Although c. 70% of cycads are threatened by extinction and extant cycads diversified during a period of increasing aridification, the vulnerability of cycads to embolism spread has been overlooked. We quantified the vulnerability to drought-induced embolism, pressure-volume curves, in situ water potentials, and a suite of xylem anatomical traits of leaf pinnae and rachises for 20 cycad species. We tested whether anatomical traits were linked to hydraulic safety in cycads. Compared with other major vascular plant clades, cycads exhibited similar embolism resistance to angiosperms and pteridophytes but were more vulnerable to embolism than noncycad gymnosperms. All 20 cycads had both tracheids and vessels, the proportions of which were unrelated to embolism resistance. Only vessel pit membrane fraction was positively correlated to embolism resistance, contrary to angiosperms. Water potential at turgor loss was significantly correlated to embolism resistance among cycads. Our results show that cycads exhibit low resistance to xylem embolism and that xylem anatomical traits - particularly vessels - may influence embolism resistance together with tracheids. This study highlights the importance of understanding the mechanisms of drought resistance in evolutionarily unique and threatened lineages like the cycads.

14.
Cytotherapy ; 26(6): 616-631, 2024 06.
Artículo en Inglés | MEDLINE | ID: mdl-38483361

RESUMEN

BACKGROUND AIMS: Human pluripotent stem cells, including embryonic stem cells and induced pluripotent stem cells, offer groundbreaking therapeutic potential for degenerative diseases and cellular repair. Despite their significance, a comprehensive bibliometric analysis in this field, particularly in relation to age-related macular degeneration (AMD), is yet to be conducted. This study aims to map the foundational and emerging areas in stem cell and AMD research through bibliometric analysis. METHODS: This study analyzed articles and reviews on stem cells and AMD from 2000 to 2022, sourced from the Web of Science Core Collection. We used VOSviewer and CiteSpace for analysis and visualization of data pertaining to countries, institutions, authors, journals, references and key words. Statistical analyses were conducted using R language and Microsoft Excel 365. RESULTS: In total, 539 publications were included, indicating an increase in global literature on stem cells and AMD from 2000 to 2022. The USA was the leading contributor, with 239 papers and the highest H-index, also the USA had the highest average citation rate per article (59.82). Notably, 50% of the top 10 institutions were from the USA, with the University of California system being the most productive. Key authors included Masayo Takahashi, Michiko Mandai, Dennis Clegg, Pete J. Coffey, Boris Stanzel, and Budd A. Tucker. Investigative Ophthalmology & Visual Science published the majority of relevant papers (n = 27). Key words like "clinical trial," "stem cell therapy," "retinal organoid," and "retinal progenitor cells" were predominant. CONCLUSIONS: Research on stem cells and AMD has grown significantly, highlighting the need for increased global cooperation. Current research prioritizes the relationship between "ipsc," "induced pluripotent stem cell," "cell culture," and "human embryonic stem cell." As stem cell culture and safety have advanced, focus has shifted to prognosis and complications post-transplantation, signifying the movement of stem cell research from labs to clinical settings.


Asunto(s)
Bibliometría , Degeneración Macular , Trasplante de Células Madre , Humanos , Células Madre Embrionarias/citología , Células Madre Embrionarias/trasplante , Células Madre Pluripotentes Inducidas/citología , Degeneración Macular/terapia , Trasplante de Células Madre/métodos
15.
Bioorg Med Chem Lett ; 98: 129596, 2024 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-38142914

RESUMEN

To identify new compounds that can effectively inhibit Mycobacterium tuberculosis (Mtb), the causative agent of tuberculosis (TB), we screened, synthesized, and evaluated a series of novel aryl fluorosulfate derivatives for their in vitro inhibitory activity against Mtb. Compound 21b exhibited an in vitro minimum inhibitory concentration (MIC) of 0.06 µM against Mtb, no cytotoxicity against both HEK293T and HepG2 mammalian cell lines, and had good in vivo mouse plasma exposure and lung concentration with a 20 mg/kg oral dose, which supports advanced development as a new chemical entity for TB treatment.


Asunto(s)
Mycobacterium tuberculosis , Tuberculosis , Animales , Humanos , Ratones , Antituberculosos , Células HEK293 , Mamíferos , Pruebas de Sensibilidad Microbiana , Relación Estructura-Actividad , Tuberculosis/tratamiento farmacológico , Ésteres del Ácido Sulfúrico/química , Ésteres del Ácido Sulfúrico/farmacología
16.
Mol Cell ; 61(4): 614-624, 2016 Feb 18.
Artículo en Inglés | MEDLINE | ID: mdl-26876938

RESUMEN

The AMP-activated protein kinase (AMPK) is the master regulator of metabolic homeostasis by sensing cellular energy status. When intracellular ATP levels decrease during energy stress, AMPK is initially activated through AMP or ADP binding and phosphorylation of a threonine residue (Thr-172) within the activation loop of its kinase domain. Here we report a key molecular mechanism by which AMPK activation is amplified under energy stress. We found that ubiquitination on AMPKα blocks AMPKα phosphorylation by LKB1. The deubiquitinase USP10 specifically removes ubiquitination on AMPKα to facilitate AMPKα phosphorylation by LKB1. Under energy stress, USP10 activity in turn is enhanced through AMPK-mediated phosphorylation of Ser76 of USP10. Thus, USP10 and AMPK form a key feedforward loop ensuring amplification of AMPK activation in response to fluctuation of cellular energy status. Disruption of this feedforward loop leads to improper AMPK activation and multiple metabolic defects.


Asunto(s)
Proteínas Quinasas Activadas por AMP/metabolismo , Ubiquitina Tiolesterasa/química , Ubiquitina Tiolesterasa/metabolismo , Animales , Metabolismo Energético , Activación Enzimática , Células HCT116 , Células HEK293 , Humanos , Ratones , Fosforilación , Proteínas Serina-Treonina Quinasas/metabolismo , Serina/metabolismo , Ubiquitinación
17.
Nucleic Acids Res ; 50(16): 9470-9489, 2022 09 09.
Artículo en Inglés | MEDLINE | ID: mdl-35947700

RESUMEN

The HAV nonstructural protein 2C is essential for virus replication; however, its precise function remains elusive. Although HAV 2C shares 24-27% sequence identity with other 2Cs, key motifs are conserved. Here, we demonstrate that HAV 2C is an ATPase but lacking helicase activity. We identified an ATPase-independent nuclease activity of HAV 2C with a preference for polyuridylic single-stranded RNAs. We determined the crystal structure of an HAV 2C fragment to 2.2 Å resolution, containing an ATPase domain, a region equivalent to enterovirus 2C zinc-finger (ZFER) and a C-terminal amphipathic helix (PBD). The PBD of HAV 2C occupies a hydrophobic pocket (Pocket) in the adjacent 2C, and we show the PBD-Pocket interaction is vital for 2C functions. We identified acidic residues that are essential for the ribonuclease activity and demonstrated mutations at these sites abrogate virus replication. We built a hexameric-ring model of HAV 2C, revealing the ribonuclease-essential residues clustering around the central pore of the ring, whereas the ATPase active sites line up at the gaps between adjacent 2Cs. Finally, we show the ribonuclease activity is shared by other picornavirus 2Cs. Our findings identified a previously unfound activity of picornavirus 2C, providing novel insights into the mechanisms of virus replication.


Asunto(s)
Virus de la Hepatitis A , Picornaviridae , Proteínas no Estructurales Virales/metabolismo , Virus de la Hepatitis A/genética , Virus de la Hepatitis A/metabolismo , Replicación Viral/genética , ARN , Picornaviridae/genética , Adenosina Trifosfatasas/genética , Ribonucleasas , ARN Viral/genética , ARN Viral/metabolismo
18.
Ecotoxicol Environ Saf ; 276: 116334, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38626607

RESUMEN

Thioacetamide (TAA) within the liver generates hepatotoxic metabolites that can be induce hepatic fibrosis, similar to the clinical pathological features of chronic human liver disease. The potential protective effect of Albiflorin (ALB), a monoterpenoid glycoside found in Paeonia lactiflora Pall, against hepatic fibrosis was investigated. The mouse hepatic fibrosis model was induced with an intraperitoneal injection of TAA. Hepatic stellate cells (HSCs) were subjected to treatment with transforming growth factor-beta (TGF-ß), while lipopolysaccharide/adenosine triphosphate (LPS/ATP) was added to stimulate mouse peritoneal macrophages (MPMs), leading to the acquisition of conditioned medium. For TAA-treated mice, ALB reduced ALT, AST, HYP levels in serum or liver. The administration of ALB reduced histopathological abnormalities, and significantly regulated the expressions of nuclear receptor-related 1 protein (NURR1) and the P2X purinoceptor 7 receptor (P2×7r) in liver. ALB could suppress HSCs epithelial-mesenchymal transition (EMT), extracellular matrix (ECM) deposition, and pro-inflammatory factor level. ALB also remarkably up-regulated NURR1, inhibited P2×7r signaling pathway, and worked as working as C-DIM12, a NURR1 agonist. Moreover, deficiency of NURR1 in activated HSCs and Kupffer cells weakened the regulatory effect of ALB on P2×7r inhibition. NURR1-mediated inhibition of inflammatory contributed to the regulation of ALB ameliorates TAA-induced hepatic fibrosis, especially based on involving in the crosstalk of HSCs-macrophage. Therefore, ALB plays a significant part in the mitigation of TAA-induced hepatotoxicity this highlights the potential of ALB as a protective intervention for hepatic fibrosis.


Asunto(s)
Células Estrelladas Hepáticas , Cirrosis Hepática , Miembro 2 del Grupo A de la Subfamilia 4 de Receptores Nucleares , Transducción de Señal , Tioacetamida , Animales , Tioacetamida/toxicidad , Células Estrelladas Hepáticas/efectos de los fármacos , Ratones , Cirrosis Hepática/inducido químicamente , Cirrosis Hepática/tratamiento farmacológico , Transducción de Señal/efectos de los fármacos , Masculino , Miembro 2 del Grupo A de la Subfamilia 4 de Receptores Nucleares/metabolismo , Miembro 2 del Grupo A de la Subfamilia 4 de Receptores Nucleares/genética , Hidrocarburos Aromáticos con Puentes/farmacología , Ratones Endogámicos C57BL , Inflamación/inducido químicamente , Inflamación/tratamiento farmacológico , Transición Epitelial-Mesenquimal/efectos de los fármacos
19.
Molecules ; 29(5)2024 Feb 29.
Artículo en Inglés | MEDLINE | ID: mdl-38474588

RESUMEN

Alcoholic liver disease (ALD) is the main factor that induces liver-related death worldwide and represents a common chronic hepatopathy resulting from binge or chronic alcohol consumption. This work focused on revealing the role and molecular mechanism of nodakenin (NK) in ALD associated with hepatic inflammation and lipid metabolism through the regulation of Nur77-P2X7r signaling. In this study, an ALD model was constructed through chronic feeding of Lieber-DeCarli control solution with or without NK treatment. Ethanol (EtOH) or NK was administered to AML-12 cells, after which Nur77 was silenced. HepG2 cells were exposed to ethanol (EtOH) and subsequently treated with recombinant Nur77 (rNur77). Mouse peritoneal macrophages (MPMs) were treated with lipopolysaccharide/adenosine triphosphate (LPS/ATP) and NK, resulting in the generation of conditioned media. In vivo, histopathological alterations were markedly alleviated by NK, accompanied by reductions in serum triglyceride (TG), aspartate aminotransferase (AST), and alanine aminotransferase (ALT) levels and the modulation of Lipin-1, SREBP1, and Nur77 levels in comparison to the EtOH-exposed group (p < 0.001). Additionally, NK reduced the production of P2X7r and NLRP3. NK markedly upregulated Nur77, inhibited P2X7r and Lipin-1, and promoted the function of Cytosporone B, a Nur77 agonist (p < 0.001). Moreover, Nur77 deficiency weakened the regulatory effect of NK on P2X7r and Lipin-1 inhibition (p < 0.001). In NK-exposed MPMs, cleaved caspase-1 and mature IL-1ß expression decreased following LPS/ATP treatment (p < 0.001). NK also decreased inflammatory-factor production in primary hepatocytes stimulated with MPM supernatant. NK ameliorated ETOH-induced ALD through a reduction in inflammation and lipogenesis factors, which was likely related to Nur77 activation. Hence, NK is a potential therapeutic approach to ALD.


Asunto(s)
Cumarinas , Glucósidos , Lipopolisacáridos , Hepatopatías Alcohólicas , Animales , Ratones , Lipopolisacáridos/farmacología , Hepatopatías Alcohólicas/metabolismo , Hígado , Etanol/metabolismo , Inflamación/metabolismo , Transducción de Señal/fisiología , Adenosina Trifosfato/metabolismo , Ratones Endogámicos C57BL , Compuestos Orgánicos
20.
Int Ophthalmol ; 44(1): 176, 2024 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-38619629

RESUMEN

PURPOSE: Conventional diagnosis of primary open angle glaucoma (POAG) needs a combination of ophthalmic examinations. An efficient assay is urgently needed for a timely POAG diagnosis. We aim to explore differential expressions of circulating microRNAs (miRNA) and provide novel miRNA biomarkers for POAG diagnosis. METHODS: A total of 180 POAG patients and 210 age-related cataract (ARC) patients were enrolled. We collected aqueous humor (AH) and plasma samples from the recruited patients. The expressions of candidate miRNAs were measured using quantitative real time polymerase chain reaction. The diagnostic ability of candidate miRNAs was analyzed by receiver operating characteristic curve. RESULTS: The expressions of miR-21-5p and miR-29b-3p were downregulated significantly in AH and plasma of POAG and miR-24-3p expression was significantly increased in AH and plasma of POAG, comparing with those of ARC. A three-miRNA panel was constructed by a binary logistic regression. And the panel could differentiate between POAG and ARC with an area under the curve of 0.8867 (sensitivity = 78.0%, specificity = 83.3%) in aqueous humor and 0.7547 (sensitivity = 73.8%, specificity = 81.2%) in plasma. Next, we verified the three-miRNA panel working as a potential diagnostic biomarker stable and reliable. At last, we identified related function and regulation pathways in vitro. CONCLUSIONS: In conclusion, we built and identified a circulating three-miRNA panel as a potential diagnostic biomarker for POAG. It may be developed into an efficient assay and help improve the POAG diagnosis in the future.


Asunto(s)
MicroARN Circulante , Glaucoma de Ángulo Abierto , MicroARNs , Humanos , Glaucoma de Ángulo Abierto/diagnóstico , Glaucoma de Ángulo Abierto/genética , MicroARNs/genética , Humor Acuoso , Biomarcadores
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