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1.
Nature ; 604(7904): 72-79, 2022 04.
Artículo en Inglés | MEDLINE | ID: mdl-35388196

RESUMEN

Covalent organic frameworks (COFs) are distinguished from other organic polymers by their crystallinity1-3, but it remains challenging to obtain robust, highly crystalline COFs because the framework-forming reactions are poorly reversible4,5. More reversible chemistry can improve crystallinity6-9, but this typically yields COFs with poor physicochemical stability and limited application scope5. Here we report a general and scalable protocol to prepare robust, highly crystalline imine COFs, based on an unexpected framework reconstruction. In contrast to standard approaches in which monomers are initially randomly aligned, our method involves the pre-organization of monomers using a reversible and removable covalent tether, followed by confined polymerization. This reconstruction route produces reconstructed COFs with greatly enhanced crystallinity and much higher porosity by means of a simple vacuum-free synthetic procedure. The increased crystallinity in the reconstructed COFs improves charge carrier transport, leading to sacrificial photocatalytic hydrogen evolution rates of up to 27.98 mmol h-1 g-1. This nanoconfinement-assisted reconstruction strategy is a step towards programming function in organic materials through atomistic structural control.

2.
PLoS Genet ; 19(5): e1010691, 2023 05.
Artículo en Inglés | MEDLINE | ID: mdl-37200372

RESUMEN

Replication protein A (RPA) is a heterotrimeric complex and the major single-strand DNA (ssDNA) binding protein in eukaryotes. It plays important roles in DNA replication, repair, recombination, telomere maintenance, and checkpoint signaling. Because RPA is essential for cell survival, understanding its checkpoint signaling function in cells has been challenging. Several RPA mutants have been reported previously in fission yeast. None of them, however, has a defined checkpoint defect. A separation-of-function mutant of RPA, if identified, would provide significant insights into the checkpoint initiation mechanisms. We have explored this possibility and carried out an extensive genetic screen for Rpa1/Ssb1, the large subunit of RPA in fission yeast, looking for mutants with defects in checkpoint signaling. This screen has identified twenty-five primary mutants that are sensitive to genotoxins. Among these mutants, two have been confirmed partially defective in checkpoint signaling primarily at the replication fork, not the DNA damage site. The remaining mutants are likely defective in other functions such as DNA repair or telomere maintenance. Our screened mutants, therefore, provide a valuable tool for future dissection of the multiple functions of RPA in fission yeast.


Asunto(s)
Schizosaccharomyces , Schizosaccharomyces/genética , Schizosaccharomyces/metabolismo , Proteínas de Unión al ADN/genética , Proteínas de Unión al ADN/metabolismo , Replicación del ADN/genética , Daño del ADN/genética , Proteína de Replicación A/genética , Proteína de Replicación A/metabolismo , Reparación del ADN/genética , ADN de Cadena Simple/metabolismo
3.
PLoS Med ; 21(2): e1004340, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38386617

RESUMEN

BACKGROUND: Screening reduces colorectal cancer (CRC) burden by allowing early resection of precancerous and cancerous lesions. An adequate selection of high-risk individuals and a high uptake rate for colonoscopy screening are critical to identifying people more likely to benefit from screening and allocating healthcare resources properly. We evaluated whether combining a questionnaire-based interview for risk factors with fecal immunochemical test (FIT) outcomes for high-risk assessment is more efficient and economical than a questionnaire-based interview-only strategy. METHODS AND FINDINGS: In this multicenter, population-based, prospective cohort study, we enrolled community residents aged 40 to 74 years in 29 provinces across China. From 2016 to 2020, a total of 1,526,824 eligible participants were consecutively enrolled in the Cancer Screening Program in Urban China (CanSPUC) cohort, and 940,605 were enrolled in the Whole Life Cycle of Cancer Screening Program (WHOLE) cohort, with follow-up to December 31, 2022. The mean ages were 56.89 and 58.61 years in CanSPUC and WHOLE, respectively. In the WHOLE cohort, high-risk individuals were identified by combining questionnaire-based interviews to collect data on risk factors (demographics, diet history, family history of CRC, etc.) with FIT outcomes (RF-FIT strategy), whereas in the CanSPUC cohort, high-risk individuals were identified using only interview-based data on risk factors (RF strategy). The primary outcomes were participation rate and yield (detection rate of advanced neoplasm, early-stage detection rate of CRCs [stage I/II], screening yield per 10,000 invitees), which were reported for the entire population and for different gender and age groups. The secondary outcome was the cost per case detected. In total, 71,967 (7.65%) and 281,985 (18.47%) individuals were identified as high-risk and were invited to undergo colonoscopy in the RF-FIT group and RF group, respectively. The colonoscopy participation rate in the RF-FIT group was 26.50% (19,071 of 71,967) and in the RF group was 19.54% (55,106 of 281,985; chi-squared test, p < 0.001). A total of 102 (0.53%) CRCs and 2,074 (10.88%) advanced adenomas were detected by the RF-FIT, versus 90 (0.16%) and 3,593 (6.52%) by the RF strategy (chi-squared test, both p < 0.001). The early-stage detection rate using the RF-FIT strategy was significantly higher than that by the RF strategy (67.05% versus 47.95%, Fisher's exact test, p = 0.016). The cost per CRC detected was $24,849 by the RF-FIT strategy versus $55,846 by the RF strategy. A limitation of the study was lack of balance between groups with regard to family history of CRC (3.5% versus 0.7%). CONCLUSIONS: Colonoscopy participation and screening yield were better with the RF-FIT strategy. The association with CRC incidence and mortality reduction should be evaluated after long-term follow-up.


Asunto(s)
Neoplasias Colorrectales , Detección Precoz del Cáncer , Humanos , Persona de Mediana Edad , Estudios de Cohortes , Colonoscopía , Neoplasias Colorrectales/diagnóstico , Neoplasias Colorrectales/epidemiología , Neoplasias Colorrectales/patología , Detección Precoz del Cáncer/métodos , Selección de Paciente , Estudios Prospectivos , Medición de Riesgo , Encuestas y Cuestionarios , Adulto , Anciano
4.
Am J Respir Crit Care Med ; 207(1): 77-88, 2023 01 01.
Artículo en Inglés | MEDLINE | ID: mdl-35900139

RESUMEN

Rationale: Over 40% of lung cancer cases occurred in never-smokers in China. However, high-risk never-smokers were precluded from benefiting from lung cancer screening as most screening guidelines did not consider them. Objectives: We sought to develop and validate prediction models for 3-year lung cancer risks for never- and ever-smokers, named the China National Cancer Center Lung Cancer models (China NCC-LCm2021 models). Methods: 425,626 never-smokers and 128,952 ever-smokers from the National Lung Cancer Screening program were used as the training cohort and analyzed using multivariable Cox models. Models were validated in two independent prospective cohorts: one included 369,650 never-smokers and 107,678 ever-smokers (841 and 421 lung cancers), and the other included 286,327 never-smokers and 78,469 ever-smokers (503 and 127 lung cancers). Measurements and Main Results: The areas under the receiver operating characteristic curves in the two validation cohorts were 0.698 and 0.673 for never-smokers and 0.728 and 0.752 for ever-smokers. Our models had higher areas under the receiver operating characteristic curves than other existing models and were well calibrated in the validation cohort. The China NCC-LCm2021 ⩾0.47% threshold was suggested for never-smokers and ⩾0.51% for ever-smokers. Moreover, we provided a range of threshold options with corresponding expected screening outcomes, screening targets, and screening efficiency. Conclusion: The construction of the China NCC-LCm2021 models can accurately reflect individual risk of lung cancer, regardless of smoking status. Our models can significantly increase the feasibility of conducting centralized lung cancer screening programs because we provide justified thresholds to define the high-risk population of lung cancer and threshold options to adapt different configurations of medical resources.


Asunto(s)
Neoplasias Pulmonares , Humanos , Neoplasias Pulmonares/diagnóstico , Neoplasias Pulmonares/epidemiología , Neoplasias Pulmonares/etiología , Estudios Prospectivos , Fumadores , Fumar/epidemiología , Detección Precoz del Cáncer , Factores de Riesgo
5.
Drug Resist Updat ; 71: 101014, 2023 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-37913652

RESUMEN

High levels of the estrogen receptor ß (ERß) predict poor prognosis following platinum-containing adjuvant chemotherapies in patients with non-small cell lung cancer (NSCLC). However, the precise role of ERß remains elusive. In this study, we demonstrated that targeting ERß could significantly increase the cytotoxicity of cisplatin both in vitro and in vivo. Mechanically, cisplatin directly binds to ERß, which facilitates its homodimerization and nuclear translocation. ERß activation transcriptionally represses the expression of DCAF8, an adaptor of CRL4 E3 ubiquitin ligase, which in turn attenuates the proteasomal degradation of ERß, leading to ERß accumulation; this positive feedback loop results in Akt activation and eventually cisplatin resistance in NSCLC through PTEN inhibition. Moreover, low expression of DCAF8 and high expression of ERß are associated with treatment resistance in patients receiving cisplatin-containing adjuvant chemotherapy. The present results provide insights into the underlying mechanism of ERß-induced cisplatin resistance and offer an alternative therapeutic strategy to improve the efficacy of platinum-based chemotherapy in patients with NSCLC.


Asunto(s)
Carcinoma de Pulmón de Células no Pequeñas , Neoplasias Pulmonares , Humanos , Carcinoma de Pulmón de Células no Pequeñas/tratamiento farmacológico , Carcinoma de Pulmón de Células no Pequeñas/genética , Cisplatino/farmacología , Cisplatino/uso terapéutico , Proteínas Proto-Oncogénicas c-akt/genética , Proteínas Proto-Oncogénicas c-akt/metabolismo , Proteínas Proto-Oncogénicas c-akt/uso terapéutico , Receptor beta de Estrógeno/genética , Receptor beta de Estrógeno/metabolismo , Receptor beta de Estrógeno/uso terapéutico , Neoplasias Pulmonares/tratamiento farmacológico , Neoplasias Pulmonares/genética , Resistencia a Antineoplásicos/genética , Retroalimentación , Línea Celular Tumoral , Fosfohidrolasa PTEN/genética , Fosfohidrolasa PTEN/uso terapéutico
6.
Cancer ; 129(18): 2871-2886, 2023 09 15.
Artículo en Inglés | MEDLINE | ID: mdl-37221876

RESUMEN

BACKGROUND: There were limited studies on the quantification of the modifiable and nonmodifiable lung cancer burden over time in China. Furthermore, the potential effect of risk factor reduction for lung cancer on gains in life expectancy (LE) remains unknown. METHODS: This study explored temporal trends in lung cancer deaths and disability-adjusted life years (DALY) attributable to modifiable risk factors from 1990 to 2019, based on the 2019 Global Burden of Disease Study. The abridged period life table method was used to quantify the effect of risk factors on LE. The authors used the decomposition approach to estimate contributions of aging metrics to change in the lung cancer burden. RESULTS: Nationally, the majority of lung cancer deaths and DALYs were attributable to behavioral and environmental risk clusters. Potential gains in life expectancy (PGLE) at birth would be 0.78 years for males and 0.35 years for females if the exposure to risk factors was mitigated to the theoretical minimum level. Tobacco use had the most robust impact on LE for both sexes (PGLE: 0.71 years for males and 0.19 years for females). From 1990 to 2019, risk-attributable age-standardized death and DALY rates of lung cancer showed an increasing trend in both sexes; adult population growth imposed 245.9 thousand deaths and 6.2 million DALYs for lung cancer. CONCLUSIONS: The modifiable risk-attributable lung cancer burden remains high in China. Effective tobacco control is the critical step toward addressing the lung cancer burden. Adult population growth was the foremost driver of transition in the age-related lung cancer burden. PLAIN LANGUAGE SUMMARY: We estimate the lung cancer burden attributable to modifiable and nonmodifiable contributors and the effect of risk factor reduction for lung cancer on the life expectancy in China. The findings suggest that the majority of lung cancer deaths and disability-adjusted life years were attributable to behavioral risk clusters, and the risk-attributable lung cancer burden increased nationally from 1990 to 2019. The average gains in life expectancy would be 0.78 years for males and 0.35 years for females if the exposure to risk factors for lung cancer was reduced to the theoretical minimum risk exposure level. Adult population growth was identified as the foremost driver of variation in the aging lung cancer burden.


Asunto(s)
Esperanza de Vida , Neoplasias Pulmonares , Adulto , Masculino , Recién Nacido , Femenino , Humanos , Años de Vida Ajustados por Calidad de Vida , Factores de Riesgo , Neoplasias Pulmonares/epidemiología , Envejecimiento , China/epidemiología
7.
Clin Gastroenterol Hepatol ; 21(3): 819-826.e13, 2023 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-36403728

RESUMEN

BACKGROUND & AIMS: A one-size-fits-all approach to colorectal cancer (CRC) screening that does not account for CRC risk factors is not conducive to personalized screening. On the basis of the principle of equal management of equal risks, we aimed to tailor and validate risk-adapted starting ages of CRC screening for individuals with different CRC risk factors. METHODS: A multi-center community-based population cohort (N = 3,165,088) was used to evaluate the starting age of CRC screening with comprehensive consideration of risk factors. Age-specific 10-year cumulative risk curves were used to determine when individuals at greater risk for CRC reached the same risk level as the 50-year-old general population, which is currently the recommended starting age for CRC screening in China. RESULTS: During the study follow-up period (2013-2021), 4,840 incident CRCs were recorded. Family history of CRC, adverse lifestyle, and comorbidities demonstrated heterogeneous associations with CRC risk (hazard ratios, 1.05-1.55; P < .05). Men and women with CRC family history and at least 2 risk factors reached the standard benchmark risk (0.28%) for screening at the age of 40, 10 years earlier than their peers without risk factors in the general population. Proposed starting ages for CRC screening were validated in an independent community-based population cohort (N = 1,023,367). CONCLUSIONS: We determined a risk-adapted CRC screening starting age for individuals with various CRC risk factors. Earlier, personalized screening based on these findings could allow for scarce health resources to be dedicated to individuals who benefit most.


Asunto(s)
Neoplasias Colorrectales , Detección Precoz del Cáncer , Masculino , Humanos , Femenino , Persona de Mediana Edad , Neoplasias Colorrectales/diagnóstico , Factores de Riesgo , Comorbilidad , Modelos de Riesgos Proporcionales , Tamizaje Masivo , Colonoscopía
8.
BMC Plant Biol ; 23(1): 118, 2023 Feb 28.
Artículo en Inglés | MEDLINE | ID: mdl-36849930

RESUMEN

BACKGROUND: Arbuscular mycorrhizal fungi (AMF) have a positive effect on drought tolerance of plants after establishing reciprocal resymbiosis with roots, while the underlying mechanism is not deciphered. Metabolomics can explain the mechanism of plant response to environmental stress by analyzing the changes of all small molecular weight metabolites. The purpose of this study was to use Ultra High Performance Liquid Chromatography Q Exactive Mass Spectrometer to analyze changes in root metabolites of walnut (Juglans regia) after inoculation with an arbuscular mycorrhizal fungus Diversispora spurca under well-watered (WW) and drought stress (DS). RESULTS: Sixty days of soil drought significantly inhibited root mycorrhizal colonization rate, shoot and root biomass production, and leaf water potential in walnut, while AMF inoculation significantly increased biomass production and leaf water potential, accompanied by a higher increase magnitude under DS versus under WW. A total of 3278 metabolites were identified. Under WW, AMF inoculation up-regulated 172 metabolites and down-regulated 61 metabolites, along with no changes in 1104 metabolites. However, under DS, AMF inoculation up-regulated 49 metabolites and down-regulated 116 metabolites, coupled with no changes in 1172 metabolites. Among them, juglone (a quinone found in walnuts) as the first ranked differential metabolite was up-regulated by AMF under WW but not under DS; 2,3,5-trihydroxy-5-7-dimethoxyflavanone as the first ranked differential metabolite was increased by AMF under DS but not under WW. The KEGG annotation showed a large number of metabolic pathways triggered by AMF, accompanied by different metabolic pathways under WW and DS. Among them, oxidative phosphorylation and phenylalanine metabolism and biosynthesis were triggered by AMF in response to WW and DS, where N-acetyl-L-phenylalanine was induced by AMF to increase under DS, while decreasing under WW. CONCLUSION: This study provides new insights into the metabolic mechanisms of mycorrhiza-enhanced drought tolerance in walnuts.


Asunto(s)
Juglans , Micorrizas , Sequías , Metabolómica , Resistencia a la Sequía
9.
Small ; 19(28): e2301298, 2023 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-36974580

RESUMEN

SnTe, emerging as an environment-friendly alternative to conventional PbTe thermoelectrics, has drawn significant attention for clean energy conversion. Here, a high peak figure of merit (ZT) of 1.45 at 873 K in Ge/Bi codoped SnTe-AgBiTe2 alloys is reported. It is demonstrated that the existence of Ge, Bi, and Ag facilitate band convergence in SnTe, resulting in remarkable enhancement of Seebeck coefficient and power factor. Simultaneously, localized lattice imperfections including dislocations, point defects, and micro/nanopore structures are caused by incorporation of Ge, Bi, and Ag, which can effectively scatter heat carrying phonons with different wavelengths and contribute to an extremely low κL of 0.61 W m-1  K-1 in Sn0.92 Ge0.04 Bi0.04 Te-10%AgBiTe2 . Such high peak ZT is achieved by decouples electron and phonon transport through band modification and localized lattice engineering, highlighting promising solutions for advancing thermoelectrics.

10.
Phys Rev Lett ; 131(25): 256002, 2023 Dec 22.
Artículo en Inglés | MEDLINE | ID: mdl-38181352

RESUMEN

The Fe_{4}Se_{5} with a sqrt[5]×sqrt[5] Fe vacancy order is suggested to be a Mott insulator and the parent state of bulk FeSe superconductor. The iron vacancy ordered state has been considered as a Mott insulator and the parent compound of bulk FeSe-based superconductors. However, for the superconducting FeSe/SrTiO_{3} monolayer (FeSe/STO) with an interface-enhanced high transition temperature (T_{c}), the electronic evolution from its Fe vacancy ordered parent phase to the superconducting state, has not been explored due to the challenge to realize an Fe vacancy order in the FeSe/STO monolayer, even though important to the understanding of superconductivity mechanism. In this study, we developed a new method to generate Fe vacancies within the FeSe/STO monolayer in a tunable fashion, with the assistance of atomic hydrogen. As a consequence, an insulating sqrt[5]×sqrt[5] Fe vacancy ordered monolayer is realized as the parent state. By using scanning tunneling microscopy and scanning tunneling spectroscopy, the spectral evolution from superconductivity to insulator is fully characterized. Surprisingly, a prominent spectral weight transfer occurs, thus implying a strong electron correlation effect. Moreover, the Fe vacancy induced insulating gap exhibits no Mott gap-like features. This work provides new insights in understanding the high-T_{c} superconductivity in FeSe/STO monolayer.

11.
Curr Microbiol ; 80(10): 321, 2023 Aug 16.
Artículo en Inglés | MEDLINE | ID: mdl-37587316

RESUMEN

Many fruits are consumed raw and act as vehicles for spreading antibiotic-resistant bacteria to consumers; hence, preventing foodborne diseases and ensuring food safety of fresh fruits are challenging. In this study, we aimed to analyze contamination in fruits and characterize antibiotic resistance genes in pathogenic microorganisms isolated from fruits. Sixty fruit samples were collected and screened for pathogenic microorganisms. The strains were identified, and the minimum inhibitory concentration for various antibiotics was determined. Antibiotic-resistant strains were analyzed by whole-genome sequencing. We isolated strain L46 from lemon samples and identified it as Rahnella aquatilis using MALDI-TOF MS and 16S rRNA sequencing. The whole genome of R. aquatilis L46 was 4.94 Mb and contained 291 putative antibiotic resistance genes (6.53%), including the gene coding for ß-lactamase RAHN-1 CTX-M-2 and conferring resistance to ampicillin, polymyxin B, nitrofurantoin, imipenem, aztreonam, and cefotaxime. Thus, fruits can pose a potential hazard to human health and require greater surveillance and attention, as they may contain pathogenic and multidrug-resistant bacteria.


Asunto(s)
Frutas , Rahnella , Humanos , ARN Ribosómico 16S/genética , Genómica , Antibacterianos/farmacología , China
12.
Ecotoxicol Environ Saf ; 253: 114660, 2023 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-36812872

RESUMEN

After intensive research on the gut-brain axis, intestinal dysbiosis is considered to be one of the important pathways of cognitive decline. Microbiota transplantation has long been thought to reverse the behavioral changes in the brain caused by colony dysregulation, but in our study, microbiota transplantation seemed to improve only behavioral brain function, and there was no reasonable explanation for the high level of hippocampal neuron apoptosis that remained. Butyric acid is one of the short-chain fatty acids of intestinal metabolites and is mainly used as an edible flavoring. It is commonly used in butter, cheese and fruit flavorings, and is a natural product of bacterial fermentation of dietary fiber and resistant starch in the colon, acting similarly to the small-molecule HDAC inhibitor TSA. The effect of butyric acid on HDAC levels in hippocampal neurons in the brain remains unclear. Therefore, this study used rats with low bacterial abundance, conditional knockout mice, microbiota transplantation, 16S rDNA amplicon sequencing, and behavioral assays to demonstrate the regulatory mechanism of short-chain fatty acids on the acetylation of hippocampal histones. The results showed that disturbance of short-chain fatty acid metabolism led to high HDAC4 expression in the hippocampus and regulated H4K8ac, H4K12ac, and H4K16ac to promote increased neuronal apoptosis. However, microbiota transplantation did not change the pattern of low butyric acid expression, resulting in maintained high HDAC4 expression in hippocampal neurons with continued neuronal apoptosis. Overall, our study shows that low levels of butyric acid in vivo can promote HDAC4 expression through the gut-brain axis pathway, leading to hippocampal neuronal apoptosis, and demonstrates that butyric acid has great potential value for neuroprotection in the brain. In this regard, we suggest that patients with chronic dysbiosis should pay attention to changes in the levels of SCFAs in their bodies, and if deficiencies occur, they should be promptly supplemented through diet and other means to avoid affecting brain health.


Asunto(s)
Disbiosis , Microbioma Gastrointestinal , Ratones , Ratas , Animales , Ácido Butírico/farmacología , Ácidos Grasos Volátiles/metabolismo , Bacterias/genética , Bacterias/metabolismo , Hipocampo/metabolismo , Apoptosis , Histona Desacetilasas/genética , Histona Desacetilasas/metabolismo , Histona Desacetilasas/farmacología
13.
Mikrochim Acta ; 190(9): 360, 2023 08 22.
Artículo en Inglés | MEDLINE | ID: mdl-37606732

RESUMEN

Carbapenem-resistant Enterobacterales pose significant global health challenges due to their rapid spread and ability to hydrolyse various beta-lactam antibiotics. Rapid tests for these carbapenemase genes are crucial to ensure appropriate prescription administration and infection control. In this study, we developed a rapid visual nanodiagnostic platform for multiplexed detection of carbapenemase genes using a lateral flow strip. The nanodiagnostic strip was designed with separate barcoded DNA tetrahedrons for the blaKPC and blaNDM genes. These tetrahedrons were distributed on a nitrocellulose membrane at two different test lines as capture probes. When tested against a panel of carbapenemase genes, the tetrahedral probes captured single-stranded amplicons of asymmetric PCR via strand hybridisation. The amplicons acted as bridging elements, binding the DNA-modified gold nanoparticles to the test line of the strip, resulting in clear visual readouts specific to the blaKPC and blaNDM genes. By employing barcoded tetrahedrons and asymmetric PCR in conjunction with the lateral flow strip, a single diagnostic test enabled the detection of multiple carbapenemase genes. The test yielded results as low as 0.12 fM for blaKPC and 0.05 fM for blaNDM within 75 min. Furthermore, the strip effectively identified specific carbapenemase genes in clinical isolates using real-time PCR, antibody-based lateral flow systems for carbapenemase detection, and carbapenemase phenotype experiments. Thus, the strip develop has a high potential for testing blaKPC and blaNDM genes in practice.


Asunto(s)
Técnicas Biosensibles , Farmacorresistencia Bacteriana , Técnicas Genéticas , Carbapenémicos/farmacología , Gammaproteobacteria/efectos de los fármacos , Gammaproteobacteria/genética , Reacción en Cadena de la Polimerasa/métodos
14.
Int J Mol Sci ; 24(9)2023 May 05.
Artículo en Inglés | MEDLINE | ID: mdl-37175973

RESUMEN

The heterotrimeric Tel2-Tti1-Tti2 or TTT complex is essential for cell viability and highly observed in eukaryotes. As the co-chaperone of ATR, ATM, DNA-PKcs, mTOR, SMG1, and TRRAP, the phosphatidylinositol 3-kinase-related kinases (PIKKs) and a group of large proteins of 300-500 kDa, the TTT plays crucial roles in genome stability, cell proliferation, telomere maintenance, and aging. Most of the protein kinases in the kinome are targeted by co-chaperone Cdc37 for proper folding and stability. Like Cdc37, accumulating evidence has established the mechanism by which the TTT interacts with chaperone Hsp90 via R2TP (Rvb1-Rvb2-Tah1-Pih1) complex or other proteins for co-translational maturation of the PIKKs. Recent structural studies have revealed the α-solenoid structure of the TTT and its interactions with the R2TP complex, which shed new light on the co-chaperone mechanism and provide new research opportunities. A series of mutations of the TTT have been identified that cause disease syndrome with neurodevelopmental defects, and misregulation of the TTT has been shown to contribute to myeloma, colorectal, and non-small-cell lung cancers. Surprisingly, Tel2 in the TTT complex has recently been found to be a target of ivermectin, an antiparasitic drug that has been used by millions of patients. This discovery provides mechanistic insight into the anti-cancer effect of ivermectin and thus promotes the repurposing of this Nobel-prize-winning medicine for cancer chemotherapy. Here, we briefly review the discovery of the TTT complex, discuss the recent studies, and describe the perspectives for future investigation.


Asunto(s)
Carcinoma de Pulmón de Células no Pequeñas , Neoplasias Pulmonares , Humanos , Proteínas HSP90 de Choque Térmico/metabolismo , Ivermectina , Chaperonas Moleculares/metabolismo , Proteínas de Unión a Telómeros/metabolismo , Fosfatidilinositol 3-Quinasas/metabolismo
15.
J Cell Mol Med ; 26(11): 3213-3222, 2022 06.
Artículo en Inglés | MEDLINE | ID: mdl-35582950

RESUMEN

Oral-facial-digital syndrome (OFDS) is a multisystemic ciliopathic disorder with an autosomal recessive mode of inheritance. OFDS usually manifests with typical craniofacial anomalies and variable occurrence of polydactyly. Germline variants in CPLANE1 cause OFDS VI. In this study, we investigated a 26-year-old Chinese female patient who was 23+1  weeks pregnant. She had a history of adverse pregnancy outcomes with multiple foetal malformations. We performed ultrasonography and identified the foetus as having a posterior fossa Blake cyst and postaxial polydactyly. The patient decided to terminate her pregnancy, and further genetic molecular analysis was performed. We identified the aborted foetus as having postaxial polydactyly. Whole-exome sequencing identified a missense variant (c.3599C>T, p.A1200V) in exon 20 and a c.834+1G>T variant in exon 7 of CPLANE1 (NM_023073.3) in the foetus. Sanger sequencing confirmed that these variants came from the parents of the foetus. In this study, we investigated a family with OFDS VI through genetic testing and bioinformatics analysis, which provided powerful help for prenatal diagnosis. Then, we demonstrated that the cell migration rate and the number of cilia were decreased after interference with CPLANE1 expression in NIH/3T3 cells. After CPLANE1 knockdown, the Hh signalling pathway was inhibited, and the Hh pathway activator SAG reversed the inhibitory effect. This is the first report of a family with OFDS VI in the Chinese population.


Asunto(s)
Anomalías Múltiples , Síndromes Orofaciodigitales , Polidactilia , Anomalías Múltiples/genética , Adulto , Animales , Cilios/genética , Femenino , Dedos/anomalías , Humanos , Ratones , Síndromes Orofaciodigitales/diagnóstico , Síndromes Orofaciodigitales/genética , Embarazo , Dedos del Pie/anomalías , Secuenciación del Exoma
16.
J Am Chem Soc ; 144(21): 9434-9442, 2022 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-35588159

RESUMEN

Electrochemically active covalent organic frameworks (COFs) are promising electrode materials for Li-ion batteries. However, improving the specific capacities of COF-based electrodes requires materials with increased conductivity and a higher concentration of redox-active groups. Here, we designed a series of pyrene-4,5,9,10-tetraone COF (PT-COF) and carbon nanotube (CNT) composites (denoted as PT-COFX, where X = 10, 30, and 50 wt % of CNT) to address these challenges. Among the composites, PT-COF50 achieved a capacity of up to 280 mAh g-1 as normalized to the active COF material at a current density of 200 mA g-1, which is the highest capacity reported for a COF-based composite cathode electrode to date. Furthermore, PT-COF50 exhibited excellent rate performance, delivering a capacity of 229 mAh g-1 at 5000 mA g-1 (18.5C). Using operando Raman microscopy the reversible transformation of the redox-active carbonyl groups of PT-COF was determined, which rationalizes an overall 4 e-/4 Li+ redox process per pyrene-4,5,9,10-tetraone unit, accounting for its superior performance as a Li-ion battery electrode.

17.
Biochem Biophys Res Commun ; 594: 139-145, 2022 02 26.
Artículo en Inglés | MEDLINE | ID: mdl-35085890

RESUMEN

Lead is a highly toxic metal that displays developmental neurotoxicity. Ambra1 plays a crucial role in embryonic neural development. At present, the role of Ambra1 in lead-induced developmental neurotoxicity remains unknown. In this study, we investigated the mechanism of Ambra1 concerning its role in lead-induced neurotoxicity. Zebrafish (Danio rerio) embryos were exposed to 0.1, 1, or 10 µM Pb until 5 days post-fertilization, and their locomotor activity was significantly impaired by the 10 µM treatment. Meanwhile, Pb reduced the expression of ambra1a and ambra1b in the brain at 48 and 72 h post-fertilization. Overexpression of ambra1a or ambra1b reversed Pb-induced alterations in locomotor activity, and decreased the apoptotic cell numbers in the brains of Pb-treated zebrafish. Our data reveal a novel protective role of Ambra1 against Pb-induced neural damage in the developing zebrafish.


Asunto(s)
Proteínas Adaptadoras Transductoras de Señales/fisiología , Lesiones Encefálicas/metabolismo , Encéfalo/efectos de los fármacos , Encéfalo/embriología , Regulación del Desarrollo de la Expresión Génica , Plomo , Movimiento/efectos de los fármacos , Proteínas de Pez Cebra/fisiología , Animales , Apoptosis , Relación Dosis-Respuesta a Droga , Embrión no Mamífero/metabolismo , Desarrollo Embrionario , Perfilación de la Expresión Génica , Silenciador del Gen , Hibridación in Situ , Larva , Sistema Nervioso , Neurogénesis , Síndromes de Neurotoxicidad/metabolismo , Neurotoxinas , Pez Cebra
18.
FEMS Yeast Res ; 22(1)2022 03 24.
Artículo en Inglés | MEDLINE | ID: mdl-35262697

RESUMEN

Schizosaccharomyces pombe is an established yeast model for studying the cellular mechanisms conserved in humans, such as the DNA replication checkpoint. The replication checkpoint deals with replication stress caused by numerous endogenous and exogenous factors that perturb fork movement. If undealt with, perturbed forks collapse, causing chromosomal DNA damage or cell death. Hydroxyurea (HU) is an inhibitor of ribonucleotide reductase (RNR) commonly used in checkpoint studies. It produces replication stress by depleting dNTPs, which slows the movement of ongoing forks and thus activates the replication checkpoint. However, HU also causes side effects such as oxidative stress, particularly under chronic exposure conditions, which complicates the studies. To find a drug that generates replication stress more specifically, we tested three other RNR inhibitors gemcitabine, guanazole and triapine in S. pombe under various experimental conditions. Our results show that guanazole and triapine can produce replication stress more specifically than HU under chronic, not acute drug treatment conditions. Therefore, using the two drugs in spot assay, the method commonly used for testing drug sensitivity in yeasts, should benefit the checkpoint studies in S. pombe and likely the research in other model systems.


Asunto(s)
Ribonucleótido Reductasas , Proteínas de Schizosaccharomyces pombe , Schizosaccharomyces , Proteínas de Ciclo Celular/metabolismo , Quinasa de Punto de Control 2/metabolismo , Replicación del ADN , Desoxicitidina/análogos & derivados , Inhibidores Enzimáticos/metabolismo , Guanazol , Humanos , Hidroxiurea/farmacología , Piridinas , Ribonucleótido Reductasas/genética , Ribonucleótido Reductasas/metabolismo , Ribonucleótido Reductasas/farmacología , Schizosaccharomyces/genética , Proteínas de Schizosaccharomyces pombe/genética , Tiosemicarbazonas , Gemcitabina
19.
Appl Opt ; 61(21): 6297-6310, 2022 Jul 20.
Artículo en Inglés | MEDLINE | ID: mdl-36256244

RESUMEN

It is important to perform contraband inspections on items before they are taken into public places in order to ensure the safety of people and property. At present, the mainstream method of judging contraband is that security inspectors observe the X-ray image of objects and judge whether they belong to contraband. Unfortunately, contraband is often hidden under other normal objects. In a high-intensity working environment, security inspectors are very prone to missed detection and wrong detection. To this end, a detection framework based on computer vision technology is proposed, which is trained and improved on the basis of the current state-of-the-art YOLOX object detection network, and adopts strategies such as feature fusion, adding a double attention mechanism and classifying regression loss. Compared with the benchmark YOLOX-S model, the proposed method achieves a higher average accuracy, with an improvement of 5.0% on the public safety SIXray dataset, opening the way to large-scale automatic detection of contraband in public places.


Asunto(s)
Algoritmos , Humanos , Rayos X
20.
Sensors (Basel) ; 22(13)2022 Jun 26.
Artículo en Inglés | MEDLINE | ID: mdl-35808333

RESUMEN

The use of fiber Bragg grating (FBG) sensors is proposed to solve the technical problem of poor sensor stability in the long-term safety monitoring of shaft lining structures. The auxiliary shaft of the Zhuxianzhuang coal mine was considered as the engineering background, and a test system implementing FBG sensors was established to monitor the long-term safety of the shaft lining structure. Indoor simulation testing revealed that the coefficient of determination (r2) between the test curves of the FBG sensor and the resistance strain gauge is greater than 0.99 in both the transverse and vertical strains. Therefore, the FBG sensor and resistance strain gauge test values are similar, and the error is small. The early warning value was obtained by calculation, according to the specific engineering geological conditions and shaft lining structure. The monitoring data obtained for the shaft lining at three test levels over more than three years reveal that the measured vertical strain value is less than the warning value, indicating that the shaft lining structure is currently in a safe state. The analysis of the monitoring data reveals that the vertical strain increment caused by the vertical additional force is approximately 0.0752 µÎµ/d. As the mine drainage progresses, the increasing vertical additional force acting on the shaft lining will compromise the safety of the shaft lining structure. Therefore, the monitoring must be enhanced to facilitate decision-making for safe shaft operation.


Asunto(s)
Tecnología de Fibra Óptica , Fibras Ópticas , Monitoreo Fisiológico
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