Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 665
Filtrar
Más filtros

Bases de datos
Tipo del documento
Intervalo de año de publicación
1.
Mol Cell ; 80(6): 996-1012.e9, 2020 12 17.
Artículo en Inglés | MEDLINE | ID: mdl-33147438

RESUMEN

Reactive aldehydes arise as by-products of metabolism and are normally cleared by multiple families of enzymes. We find that mice lacking two aldehyde detoxifying enzymes, mitochondrial ALDH2 and cytoplasmic ADH5, have greatly shortened lifespans and develop leukemia. Hematopoiesis is disrupted profoundly, with a reduction of hematopoietic stem cells and common lymphoid progenitors causing a severely depleted acquired immune system. We show that formaldehyde is a common substrate of ALDH2 and ADH5 and establish methods to quantify elevated blood formaldehyde and formaldehyde-DNA adducts in tissues. Bone-marrow-derived progenitors actively engage DNA repair but also imprint a formaldehyde-driven mutation signature similar to aging-associated human cancer mutation signatures. Furthermore, we identify analogous genetic defects in children causing a previously uncharacterized inherited bone marrow failure and pre-leukemic syndrome. Endogenous formaldehyde clearance alone is therefore critical for hematopoiesis and in limiting mutagenesis in somatic tissues.


Asunto(s)
Alcohol Deshidrogenasa/genética , Aldehído Deshidrogenasa Mitocondrial/genética , Formaldehído/sangre , Leucemia/genética , Adolescente , Aldehídos/sangre , Animales , Niño , Preescolar , Aductos de ADN/genética , Daño del ADN/efectos de los fármacos , Reparación del ADN/efectos de los fármacos , Femenino , Formaldehído/toxicidad , Hematopoyesis/genética , Células Madre Hematopoyéticas/metabolismo , Humanos , Lactante , Leucemia/sangre , Leucemia/patología , Masculino , Ratones , Mutación/genética , Especificidad por Sustrato
2.
Plant Cell ; 35(5): 1593-1616, 2023 04 20.
Artículo en Inglés | MEDLINE | ID: mdl-36695476

RESUMEN

High salinity, an adverse environmental factor affecting about 20% of irrigated arable land worldwide, inhibits plant growth and development by causing oxidative stress, damaging cellular components, and disturbing global metabolism. However, whether and how reactive oxygen species disturb the metabolism of salt-stressed plants remain elusive. Here, we report that salt-induced hydrogen peroxide (H2O2) inhibits the activity of plastid triose phosphate isomerase (pdTPI) to promote methylglyoxal (MG) accumulation and stimulates the sulfenylation of pdTPI at cysteine 74. We also show that MG is a key factor limiting the plant growth, as a decrease in MG levels completely rescued the stunted growth and repressed salt stress tolerance of the pdtpi mutant. Furthermore, targeting CATALASE 2 into chloroplasts to prevent salt-induced overaccumulation of H2O2 conferred salt stress tolerance, revealing a role for chloroplastic H2O2 in salt-caused plant damage. In addition, we demonstrate that the H2O2-mediated accumulation of MG in turn induces H2O2 production, thus forming a regulatory loop that further inhibits the pdTPI activity in salt-stressed plants. Our findings, therefore, illustrate how salt stress induces MG production to inhibit the plant growth.


Asunto(s)
Peróxido de Hidrógeno , Piruvaldehído , Peróxido de Hidrógeno/metabolismo , Piruvaldehído/metabolismo , Estrés Salino , Estrés Oxidativo , Plantas/metabolismo , Cloroplastos/metabolismo , Estrés Fisiológico
3.
J Biol Chem ; 299(7): 104854, 2023 07.
Artículo en Inglés | MEDLINE | ID: mdl-37224962

RESUMEN

Functional depletion of the U1 small nuclear ribonucleoprotein (snRNP) with a 25 nt U1 AMO (antisense morpholino oligonucleotide) may lead to intronic premature cleavage and polyadenylation of thousands of genes, a phenomenon known as U1 snRNP telescripting; however, the underlying mechanism remains elusive. In this study, we demonstrated that U1 AMO could disrupt U1 snRNP structure both in vitro and in vivo, thereby affecting the U1 snRNP-RNAP polymerase II interaction. By performing chromatin immunoprecipitation sequencing for phosphorylation of Ser2 and Ser5 of the C-terminal domain of RPB1, the largest subunit of RNAP polymerase II, we showed that transcription elongation was disturbed upon U1 AMO treatment, with a particular high phosphorylation of Ser2 signal at intronic cryptic polyadenylation sites (PASs). In addition, we showed that core 3'processing factors CPSF/CstF are involved in the processing of intronic cryptic PAS. Their recruitment accumulated toward cryptic PASs upon U1 AMO treatment, as indicated by chromatin immunoprecipitation sequencing and individual-nucleotide resolution CrossLinking and ImmunoPrecipitation sequencing analysis. Conclusively, our data suggest that disruption of U1 snRNP structure mediated by U1 AMO provides a key for understanding the U1 telescripting mechanism.


Asunto(s)
Morfolinos , Oligonucleótidos Antisentido , Precursores del ARN , Ribonucleoproteína Nuclear Pequeña U1 , Morfolinos/metabolismo , Oligonucleótidos Antisentido/metabolismo , Oligonucleótidos Antisentido/farmacología , Poliadenilación , Ribonucleoproteína Nuclear Pequeña U1/genética , Ribonucleoproteína Nuclear Pequeña U1/metabolismo , ARN Polimerasa II/genética , ARN Polimerasa II/metabolismo , Precursores del ARN/metabolismo , Humanos , Células HeLa , Técnicas de Silenciamiento del Gen , Factor de Especificidad de Desdoblamiento y Poliadenilación , Factor de Estimulación del Desdoblamiento/metabolismo , Transcripción Genética/efectos de los fármacos
4.
Bioinformatics ; 39(1)2023 01 01.
Artículo en Inglés | MEDLINE | ID: mdl-36477791

RESUMEN

MOTIVATION: DNA methylation within gene body and promoters in cancer cells is well documented. An increasing number of studies showed that cytosine-phosphate-guanine (CpG) sites falling within other regulatory elements could also regulate target gene activation, mainly by affecting transcription factors (TFs) binding in human cancers. This led to the urgent need for comprehensively and effectively collecting distinct cis-regulatory elements and TF-binding sites (TFBS) to annotate DNA methylation regulation. RESULTS: We developed a database (CanMethdb, http://meth.liclab.net/CanMethdb/) that focused on the upstream and downstream annotations for CpG-genes in cancers. This included upstream cis-regulatory elements, especially those involving distal regions to genes, and TFBS annotations for the CpGs and downstream functional annotations for the target genes, computed through integrating abundant DNA methylation and gene expression profiles in diverse cancers. Users could inquire CpG-target gene pairs for a cancer type through inputting a genomic region, a CpG, a gene name, or select hypo/hypermethylated CpG sets. The current version of CanMethdb documented a total of 38 986 060 CpG-target gene pairs (with 6 769 130 unique pairs), involving 385 217 CpGs and 18 044 target genes, abundant cis-regulatory elements and TFs for 33 TCGA cancer types. CanMethdb might help biologists perform in-depth studies of target gene regulations based on DNA methylations in cancer. AVAILABILITY AND IMPLEMENTATION: The main program is available at https://github.com/chunquanlipathway/CanMethdb. SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.


Asunto(s)
Metilación de ADN , Neoplasias , Humanos , Factores de Transcripción/metabolismo , Genoma , Secuencias Reguladoras de Ácidos Nucleicos , Regiones Promotoras Genéticas , Neoplasias/genética , ADN/metabolismo , Islas de CpG
5.
New Phytol ; 242(1): 211-230, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38326975

RESUMEN

Microbe-produced secondary metabolite phenazine-1-carboxylic acid (PCA) facilitates pathogen virulence and defense mechanisms against competitors. Magnaporthe oryzae, a causal agent of the devastating rice blast disease, needs to compete with other phyllosphere microbes and overcome host immunity for successful colonization and infection. However, whether M. oryzae produces PCA or it has any other functions remains unknown. Here, we found that the MoPHZF gene encodes the phenazine biosynthesis protein MoPhzF, synthesizes PCA in M. oryzae, and regulates appressorium formation and host virulence. MoPhzF is likely acquired through an ancient horizontal gene transfer event and has a canonical function in PCA synthesis. In addition, we found that PCA has a role in suppressing the accumulation of host-derived reactive oxygen species (ROS) during infection. Further examination indicated that MoPhzF recruits both the endoplasmic reticulum membrane protein MoEmc2 and the regulator of G-protein signaling MoRgs1 to the plasma membrane (PM) for MoRgs1 phosphorylation, which is a critical regulatory mechanism in appressorium formation and pathogenicity. Collectively, our studies unveiled a canonical function of MoPhzF in PCA synthesis and a noncanonical signaling function in promoting appressorium formation and host infection.


Asunto(s)
Ascomicetos , Magnaporthe , Oryza , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Oryza/metabolismo , Fenazinas/metabolismo , Enfermedades de las Plantas/genética
6.
J Med Virol ; 96(2): e29400, 2024 02.
Artículo en Inglés | MEDLINE | ID: mdl-38293843

RESUMEN

Serum hepatitis B virus (HBV) spliced RNAs (spRNAs) are ubiquitous in HBV-infected patients; however, their clinical significance remains unknown. Therefore, we aimed to explore the relationship between HBV spRNAs and liver disease progression in chronic hepatitis B (CHB) patients; in vitro cell line assessment was also performed. The serum HBV wild-type RNA (wtRNA) and spRNA levels were individually quantified in a cohort of 279 treatment-naïve, hepatitis B e antigen positive CHB patients with or without cirrhosis. The spRNA proportion was determined as (spRNA × 100%)/(spRNAs + wtRNA). 20 patients' serum samples underwent spRNA species profiling using next-generation sequencing. Serum spRNA species 1, 2, 3, 4, and 5 were the most common variants. The spRNA proportion varied from 0.00% to 19.02%, with higher levels in HBV genotype C patients than in those with genotype B (1.76% vs. 0.84%, p < 0.001). The spRNA proportion was positively associated with the alanine aminotransferase levels (r = 0.144, p = 0.053) and significantly higher in cirrhotic than in non-cirrhotic patients (1.69% vs. 1.04%, p = 0.001). Multivariate analysis revealed a 2.566-fold higher risk of cirrhosis in patients with elevated spRNA proportion (p = 0.024). In vitro experiments confirmed that spRNAs contributed to hepatic stellate cell activation, which is critical in liver fibrosis development. Therefore, increased HBV spRNA expression poses a risk for liver disease progression. Quantifying serum HBV spRNAs can aid in monitoring liver disease progression. Furthermore, the therapeutic targeting of spRNAs may improve the prognosis of patients with CHB.


Asunto(s)
Virus de la Hepatitis B , Hepatitis B Crónica , Humanos , Virus de la Hepatitis B/genética , Hepatitis B Crónica/tratamiento farmacológico , ARN/uso terapéutico , Cirrosis Hepática/complicaciones , Antígenos e de la Hepatitis B , Progresión de la Enfermedad , ADN Viral/genética
7.
Plant Cell Environ ; 2024 Aug 29.
Artículo en Inglés | MEDLINE | ID: mdl-39205629

RESUMEN

Over the past century, environmental changes have significantly impacted wheat spike morphology, crucial for adaptation and grain yield. However, the changes in wheat spike modifications during this period remain largely unknown. This study examines 16 spike morphology traits in 830 accessions released from 1900 to 2020. It finds that spike weight, grain number per spike (GN), and thousand kernel weight have significantly increased, while spike length has no significant change. The increase in fertile spikelets is due to fewer degenerated spikelets, resulting in a higher GN. Genome-wide association studies identified 49,994 significant SNPs, grouped into 293 genomic regions. The accumulation of favorable alleles in these genomic regions indicates the genetic basis for modification in spike morphology traits. Genetic network analysis of these genomic regions reveals the genetic basis for phenotypic correlations among spike morphology traits. The haplotypes of the identified genomic regions display obvious geographical differentiation in global accessions and environmental adaptation over the past 120 years. In summary, we reveal the genetic basis of adaptive evolution and the interactions of spike morphology, offering valuable resources for the genetic improvement of spike morphology to enhance environmental adaptation.

8.
Neurobiol Learn Mem ; : 107991, 2024 Oct 14.
Artículo en Inglés | MEDLINE | ID: mdl-39414127

RESUMEN

In laboratories, classical fear conditioning and extinction procedures are commonly used to study the behavioral and neural mechanisms underlying fear regulation. Contextual fear conditioning involves the association of an aversive event with the environment where it occurs, which engages the hippocampus and its interactions with the amygdala. The orbitofrontal cortex (OFC), divided into the lateral OFC (lOFC) and medial OFC (mOFC) subregions, plays a crucial role in integrating contextual information from the hippocampus and modulating behavioral responses based on the anticipated outcomes of the context. Because of the extensive anatomical connections of the OFC with the fear circuit, including the hippocampus, the amygdala, and the medial prefrontal cortex, and the reasoning that proper retrieval of fear-related memory is context-dependent, we raised the question to investigate the ability of the animals to discriminate between contexts when they were trained under differential OFC activation levels during the encoding of contextual fear memory. In this study, we conducted a contextual fear conditioning procedure in rats using footshock as an unconditioned stimulus (US), followed by the test of their fear levels in contexts same (dangerous) or different (safe) from the conditioning context. We used a pharmacological approach to modulate the activation levels of the lOFC or the mOFC during conditioning to examine their roles on context-specific fear encoding. Our findings showed that the animals could accurately distinguish between the two contexts in control and OFC hypoactivation groups, but failed to do so if they were trained under OFC hyperactivation. Therefore, OFC hyperactivity disturbed the encoding of contextual information during fear acquisition.

9.
Scand J Immunol ; 99(6): e13366, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38720518

RESUMEN

Antiphospholipid syndrome is a rare autoimmune disease characterized by persistent antiphospholipid antibodies. Immunoglobulin G plays a vital role in disease progression, with its structure and function affected by glycosylation. We aimed to investigate the changes in the serum immunoglobulin G glycosylation pattern in antiphospholipid syndrome patients. We applied lectin microarray on samples from 178 antiphospholipid syndrome patients, 135 disease controls (including Takayasu arteritis, rheumatoid arthritis and cardiovascular disease) and 100 healthy controls. Lectin blots were performed for validation of significant differences. Here, we show an increased immunoglobulin G-binding level of soybean agglutinin (p = 0.047, preferring N-acetylgalactosamine) in antiphospholipid syndrome patients compared with healthy and disease controls. Additionally, the immunoglobulin G from antiphospholipid syndrome patients diagnosed with pregnancy events had lower levels of fucosylation (p = 0.001, recognized by Lotus tetragonolobus) and sialylation (p = 0.030, recognized by Sambucus nigra I) than those with simple thrombotic events. These results suggest the unique serum immunoglobulin G glycosylation profile of antiphospholipid syndrome patients, which may inform future studies to design biomarkers for more accurate diagnosis of antiphospholipid syndrome and even for the prediction of clinical symptoms in patients.


Asunto(s)
Síndrome Antifosfolípido , Inmunoglobulina G , Humanos , Síndrome Antifosfolípido/inmunología , Síndrome Antifosfolípido/sangre , Síndrome Antifosfolípido/diagnóstico , Glicosilación , Femenino , Masculino , Inmunoglobulina G/sangre , Inmunoglobulina G/inmunología , Adulto , Persona de Mediana Edad , Embarazo , Lectinas/sangre , Lectinas/metabolismo , Lectinas/inmunología , Biomarcadores/sangre , Análisis por Matrices de Proteínas/métodos , Anticuerpos Antifosfolípidos/sangre , Anticuerpos Antifosfolípidos/inmunología , Lectinas de Plantas/metabolismo , Lectinas de Plantas/inmunología , Anciano , Glicoproteínas
10.
Opt Lett ; 49(4): 862-865, 2024 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-38359201

RESUMEN

A diode-pumped wavelength switchable passively Q-switched 2.3 µm Tm:YVO4 laser was demonstrated in this work. A Cr:ZnS saturable absorber was introduced into the cavity for initiating passive Q-switching. With the increase of the absorbed pump power, the passively Q-switched laser could be switched from the single wavelength of 2366 nm to the dual wavelength of 2290 and 2360 nm. The pulse duration and pulse repetition frequency could be tuned in the ranges of 0.745-1.782 µs and 2.9-43.4 kHz, respectively. The pulse energy and peak power were estimated to be 7.5 µJ and 10 W, respectively, at an absorbed pump power of 12 W.

11.
Hum Genomics ; 17(1): 108, 2023 Nov 27.
Artículo en Inglés | MEDLINE | ID: mdl-38012712

RESUMEN

Recent advances in next-generation sequencing (NGS) technology have greatly accelerated the need for efficient annotation to accurately interpret clinically relevant genetic variants in human diseases. Therefore, it is crucial to develop appropriate analytical tools to improve the interpretation of disease variants. Given the unique genetic characteristics of mitochondria, including haplogroup, heteroplasmy, and maternal inheritance, we developed a suite of variant analysis toolkits specifically designed for primary mitochondrial diseases: the Mitochondrial Missense Variant Annotation Tool (MmisAT) and the Mitochondrial Missense Variant Pathogenicity Predictor (MmisP). MmisAT can handle protein-coding variants from both nuclear DNA and mtDNA and generate 349 annotation types across six categories. It processes 4.78 million variant data in 76 min, making it a valuable resource for clinical and research applications. Additionally, MmisP provides pathogenicity scores to predict the pathogenicity of genetic variations in mitochondrial disease. It has been validated using cross-validation and external datasets and demonstrated higher overall discriminant accuracy with a receiver operating characteristic (ROC) curve area under the curve (AUC) of 0.94, outperforming existing pathogenicity predictors. In conclusion, the MmisAT is an efficient tool that greatly facilitates the process of variant annotation, expanding the scope of variant annotation information. Furthermore, the development of MmisP provides valuable insights into the creation of disease-specific, phenotype-specific, and even gene-specific predictors of pathogenicity, further advancing our understanding of specific fields.


Asunto(s)
Biología Computacional , Enfermedades Mitocondriales , Humanos , Mitocondrias/genética , Enfermedades Mitocondriales/genética , ADN Mitocondrial/genética , Mutación Missense , Secuenciación de Nucleótidos de Alto Rendimiento
12.
Nephrol Dial Transplant ; 39(2): 251-263, 2024 Jan 31.
Artículo en Inglés | MEDLINE | ID: mdl-37458807

RESUMEN

BACKGROUND: To explore the cut-off values of haemoglobin (Hb) on adverse clinical outcomes in incident peritoneal dialysis (PD) patients based on a national-level database. METHODS: The observational cohort study was from the Peritoneal Dialysis Telemedicine-assisted Platform (PDTAP) dataset. The primary outcomes were all-cause mortality, major adverse cardiovascular events (MACE) and modified MACE (MACE+). The secondary outcomes were the occurrences of hospitalization, first-episode peritonitis and permanent transfer to haemodialysis (HD). RESULTS: A total of 2591 PD patients were enrolled between June 2016 and April 2019 and followed up until December 2020. Baseline and time-averaged Hb <100 g/l were associated with all-cause mortality, MACE, MACE+ and hospitalizations. After multivariable adjustments, only time-averaged Hb <100 g/l significantly predicted a higher risk for all-cause mortality {hazard ratio [HR] 1.83 [95% confidence interval (CI) 1.19-281], P = .006}, MACE [HR 1.99 (95% CI 1.16-3.40), P = .012] and MACE+ [HR 1.77 (95% CI 1.15-2.73), P = .010] in the total cohort. No associations between Hb and hospitalizations, transfer to HD and first-episode peritonitis were observed. Among patients with Hb ≥100 g/l at baseline, younger age, female, use of iron supplementation, lower values of serum albumin and renal Kt/V independently predicted the incidence of Hb <100 g/l during the follow-up. CONCLUSION: This study provided real-world evidence on the cut-off value of Hb for predicting poorer outcomes through a nation-level prospective PD cohort.


Asunto(s)
Fallo Renal Crónico , Diálisis Peritoneal , Peritonitis , Humanos , Femenino , Estudios Prospectivos , Diálisis Peritoneal/efectos adversos , Diálisis Renal/efectos adversos , Hemoglobinas , Fallo Renal Crónico/epidemiología , Peritonitis/etiología , Estudios Retrospectivos
13.
Pharmacol Res ; 201: 107080, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38272335

RESUMEN

Thanks to the advancements in bioinformatics, drugs, and other interventions that modulate microbes to treat diseases have been emerging continuously. In recent years, an increasing number of databases related to traditional Chinese medicine (TCM) or gut microbes have been established. However, a database combining the two has not yet been developed. To accelerate TCM research and address the traditional medicine and micro ecological system connection between short board, we have developed the most comprehensive micro-ecological database of TCM. This initiative includes the standardization of the following advantages: (1) A repeatable process achieved through the standardization of a retrieval strategy to identify literature. This involved identifying 419 experiment articles from PubMed and six authoritative databases; (2) High-quality data integration achieved through double-entry extraction of literature, mitigating uncertainties associated with natural language extraction; (3) Implementation of a similar strategy aiding in the prediction of mechanisms of action. Leveraging drug similarity, target entity similarity, and known drug-target entity association, our platform enables the prediction of the effects of a new herb or acupoint formulas using the existing data. In total, MicrobeTCM includes 171 diseases, 725 microbes, 1468 herb-formulas, 1032 herbs, 15780 chemical compositions, 35 acupoint-formulas, and 77 acupoints. For further exploration, please visit https://www.microbetcm.com.


Asunto(s)
Medicina Tradicional China , Microbiota , Medicina Tradicional , Biología Computacional , Bases de Datos Factuales
14.
Inorg Chem ; 63(29): 13392-13401, 2024 Jul 22.
Artículo en Inglés | MEDLINE | ID: mdl-38991459

RESUMEN

Fused porphyrinoids have received increasing interest in light of their extended conjugation and unique coordination behavior. On the basis of our previously reported multiply fused pentaphyrin isomers 1 and 2, a novel isomer 3 has been synthesized in this work. 3 possesses a hexacyclic fused moiety with a nearly coplanar CCNN cavity involving an inverted pyrrole, which is slightly different from the CNNN ones of 1 and 2 involving an N-confused pyrrole. 1-3 possess cavities with three depronatable protons and thus they all can generate Cu(III) complexes. However, only 3Cu is stable under ambient conditions. On the other hand, 3 remains intact upon treatment with Pd(II) ions, while 1 and 2 could undergo structural rearrangement to accommodate Pd(II), affording 1Pd and 2Pd accompanied by the formation of a lactone ring and the addition of a methoxy group, respectively. Compared with the free bases, the complexes show distinct aromaticity and more intense near-infrared (NIR) absorption up to ca. 1600, 1170, and 1500 nm, respectively. The results indicate that the subtle modification of the linking modes between the pyrrolic units in the fused pentaphyrinoids is effective in modulating the coordination behavior for synthesizing complexes with tunable aromaticity and NIR absorption.

15.
Macromol Rapid Commun ; : e2400528, 2024 Oct 18.
Artículo en Inglés | MEDLINE | ID: mdl-39422630

RESUMEN

Hypoxic diabetic foot ulcers (HDFUs) pose a challenging chronic condition characterized by oxidative stress damage, bacterial infection, and persistent inflammation. This study introduces a novel therapeutic approach combining ergothioneine (EGT), luteolin (LUT), and quaternized chitosan oxidized dextran (QCOD) to address these challenges and facilitate wound healing in hypoxic DFUs. In vitro, assessments have validated the biosafety, antioxidant, and antimicrobial properties of the ergothioneine-luteolin-chitin (QCOD@EGT-LUT) hydrogel. Furthermore, near-infrared II (NIR-II) fluorescence image-guided the application of QCOD@EGT-LUT hydrogel in simulated HDFUs. Mechanistically, QCOD@EGT-LUT hydrogel modulates the diabetic wound microenvironment by reducing reactive oxygen species (ROS). In vivo studies demonstrated increased expression of angiogenic factors mannose receptor (CD206) and latelet endothelial cell adhesion molecule-1 (PECAM-1/CD31), coupled with decreased inflammatory factors tumor necrosis factor-α (TNF-α) and Interleukin-6 (IL-6), thereby promoting diabetic wound healing through up-regulation of transforming growth factor ß-1 (TGF-ß1).

16.
Phys Chem Chem Phys ; 26(35): 23010-23022, 2024 Sep 11.
Artículo en Inglés | MEDLINE | ID: mdl-39171693

RESUMEN

Zn-Cu alloys have attracted great attention as biodegradable alloys owing to their excellent mechanical properties and biocompatibility, with corrosion characteristics being crucial for their suitability for biomedical applications. However, the unresolved identification of intermetallic compounds in Zn-Cu alloys affecting corrosion and the complexity of the application environment hamper the understanding of their electrochemical behavior. Utilizing high-throughput first-principles calculations and machine-learning accelerated evolutionary algorithms for screening the most stable compounds in Zn-Cu systems, a dataset encompassing the formation energy of 2033 compounds is generated. It reveals that most of the experimentally reported Zn-Cu compounds can be replicated, especially the structure of R32 CuZn5 is first discovered which possesses the lowest formation energy of -0.050 eV per atom. Furthermore, the simulated X-ray diffraction pattern matches perfectly with the experimental ones. By formulating 342 potential electrochemical reactions based on the binary compounds, the Pourbaix diagrams for Zn-Cu alloys are constructed to clarify the fundamental competition between different phases and ions. The calculated equilibrium potential of CuZn5 is higher than that of Zn through the forward reaction Zn + CuZn5 ⇌ CuZn5 + Zn2+ + 2e-, resulting in microcell formation owing to the stronger charge density localization in Zn compared to CuZn5. The presence of chlorine accelerates the corrosion of Zn through the reaction Zn + CuZn5 + 6Cl- + 6H2O ⇌ Cu + 6ZnOHCl + 6H+ + 12e-, where the formation of ZnOHCl disrupts the ZnO passive film and expands the corrosion pH range from 9.2 to 8.8. Our findings reveal an accurate quantitative corrosion mechanism for Zn-Cu alloys, providing an effective pathway to investigate the corrosion resistance of biodegradable alloys.

17.
Antonie Van Leeuwenhoek ; 118(1): 12, 2024 Sep 28.
Artículo en Inglés | MEDLINE | ID: mdl-39340698

RESUMEN

A Gram-staining-negative, dark pink, rod-shaped, amastigote and cellulose-degrading strain, designated H9T, was isolated from intestinal contents of Nipponacmea schrenckii. The isolate was able to grow at 4-42 °C (optimum, 25 °C), at pH 6.5-9.0 (optimum, pH 7.0), and with 0.0-11.0% (w/v) NaCl (optimum, 3.0-5.0%). Phylogenetic analysis of the 16S rRNA gene sequence suggested that isolate H9T belongs to the genus Roseobacter, neighboring Roseobacter insulae YSTF-M11T, Roseobacter cerasinus AI77T and Roseobacter ponti MM-7 T, and the pairwise sequence showed the highest similarity of 99.1% to Roseobacter insulae YSTF-M11T. The major fatty acid was summed feature 8 (C18:1ω7c and/or C18:1ω6c; 81.08%). The predominant respiratory quinone was Q-10. The polar lipids consisted of phosphatidylcholine, phosphatidylglycerol, an unknown lipid, and a small amount of an unknown phospholipid. The genome of strain H9T was 5,351,685 bp in length, and the DNA G + C content was 59.8%. The average amino acid identity (AAI), average nucleotide identity (ANI), and digital DNA hybridization (dDDH) values between strain H9T and closely related strains were 63.4-76.8%, 74.7-78.8%, and 13.4-19.7%, respectively. On the basis of the phenotypic, chemical taxonomic, and phylogenetic data, it is suggested that strain H9T should represent a novel species in the genus Roseobacter, for which the name Roseobacter weihaiensis sp. nov. is proposed. The type strain is H9T (= KCTC 82507 T = MCCC 1K04354T).


Asunto(s)
Composición de Base , Celulosa , ADN Bacteriano , Ácidos Grasos , Filogenia , ARN Ribosómico 16S , Roseobacter , China , ARN Ribosómico 16S/genética , Celulosa/metabolismo , ADN Bacteriano/genética , Ácidos Grasos/metabolismo , Roseobacter/clasificación , Roseobacter/genética , Roseobacter/aislamiento & purificación , Roseobacter/metabolismo , Animales , Técnicas de Tipificación Bacteriana , Análisis de Secuencia de ADN , Genoma Bacteriano , Intestinos/microbiología , Fosfolípidos/análisis
18.
J Nanobiotechnology ; 22(1): 527, 2024 Aug 31.
Artículo en Inglés | MEDLINE | ID: mdl-39217379

RESUMEN

BACKGROUND: Cardiac iron overload and ferroptosis greatly contribute to the poor prognosis of myocardial infarction (MI). Iron chelator is one of the most promising strategies for scavenging excessive iron and alleviating cardiac dysfunction post MI. However, various side effects of existing chemical iron chelators restrict their clinical application, which calls for a more viable and safer approach to protect against iron injury in ischemic hearts. RESULTS: In this study, we isolated macrophage-derived extracellular vesicles (EVs) and identified macrophage-derived EVs as a novel endogenous biological chelator for iron. The administration of macrophage-derived EVs effectively reduced iron overload in hypoxia-treated cardiomyocytes and hearts post MI. Moreover, the oxidative stress and ferroptosis induced by excessive iron were considerably suppressed by application of macrophage-derived EVs. Mechanistically, transferrin receptor (TfR), which was inherited from macrophage to the surface of EVs, endowed EVs with the ability to bind to transferrin and remove excess protein-bound iron. EVs with TfR deficiency exhibited a loss of function in preventing MI-induced iron overload and protecting the heart from MI injury. Furthermore, the iron-chelating EVs were ultimately captured and processed by macrophages in the liver. CONCLUSIONS: These results highlight the potential of macrophage-derived EVs as a powerful endogenous candidate for iron chelation therapy, offering a novel and promising therapeutic approach to protect against iron overload-induced injury in MI and other cardiovascular diseases.


Asunto(s)
Vesículas Extracelulares , Quelantes del Hierro , Sobrecarga de Hierro , Macrófagos , Ratones Endogámicos C57BL , Infarto del Miocardio , Receptores de Transferrina , Infarto del Miocardio/metabolismo , Animales , Vesículas Extracelulares/metabolismo , Sobrecarga de Hierro/metabolismo , Macrófagos/metabolismo , Macrófagos/efectos de los fármacos , Ratones , Quelantes del Hierro/farmacología , Quelantes del Hierro/uso terapéutico , Receptores de Transferrina/metabolismo , Masculino , Hierro/metabolismo , Miocitos Cardíacos/metabolismo , Ferroptosis/efectos de los fármacos , Estrés Oxidativo/efectos de los fármacos , Transferrina/metabolismo , Humanos
19.
Arch Toxicol ; 98(8): 2429-2439, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-38722348

RESUMEN

With advances in next-generation sequencing technology, there is growing evidence that the gut microbiome plays a key role in the host's innate and adaptive immune system. Gut microbes and their metabolites directly or indirectly regulate host immune cells. Crucially, dysregulation of the gut microbiota is often associated with many immune system diseases. In turn, microbes modulate disease immunotherapy. Data from preclinical to clinical studies suggest that the gut microbiota may influence the effectiveness of tumor immunotherapy, particularly immune checkpoint inhibitors (ICIs). In addition, the most critical issue now is a COVID-19 vaccine that generates strong and durable immunity. A growing number of clinical studies confirm the potential of gut microbes to enhance the efficacy of COVID-19 vaccines. However, it is still unclear how gut bacteria interact with immune cells and what treatments are based on gut microbes. Here, we outline recent advances in the effects and mechanisms of the gut microbiota and its metabolites (tryptophan metabolites, bile acids, short-chain fatty acids, and inosine) on different immune cells (dendritic cells, CD4+T cells, and macrophages). It also highlights innovative intervention strategies and clinical trials of microbiota-based checkpoint blocking therapies for tumor immunity, and ongoing efforts to maintain the long-term immunogenicity of COVID-19 vaccines. Finally, the challenges to be overcome in this area are discussed. These provide an important basis for further research and clinical translation of gut microbiota.


Asunto(s)
COVID-19 , Microbioma Gastrointestinal , Inmunoterapia , Humanos , Microbioma Gastrointestinal/inmunología , Inmunoterapia/métodos , COVID-19/inmunología , COVID-19/prevención & control , COVID-19/terapia , Vacunas contra la COVID-19/inmunología , Inhibidores de Puntos de Control Inmunológico/uso terapéutico , Inhibidores de Puntos de Control Inmunológico/farmacología , Animales , SARS-CoV-2/inmunología , Neoplasias/inmunología , Neoplasias/terapia
20.
Arch Toxicol ; 98(5): 1297-1310, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38498160

RESUMEN

Lung injury has been a serious medical problem that requires new therapeutic approaches and biomarkers. Circular RNAs (circRNAs) are non-coding RNAs (ncRNAs) that exist widely in eukaryotes. CircRNAs are single-stranded RNAs that form covalently closed loops. CircRNAs are significant gene regulators that have a role in the development, progression, and therapy of lung injury by controlling transcription, translating into protein, and sponging microRNAs (miRNAs) and proteins. Although the study of circRNAs in lung injury caused by pulmonary toxicants is just beginning, several studies have revealed their expression patterns. The function that circRNAs perform in relation to pulmonary toxicants (severe acute respiratory distress syndrome coronavirus-2 (SARS-CoV-2), drug abuse, PM2.5, and cigarette smoke) is the main topic of this review. A variety of circRNAs can serve as potential biomarkers of lung injury. In this review, the biogenesis, properties, and biological functions of circRNAs were concluded, and the relationship between circRNAs and pulmonary toxicants was discussed. It is expected that the new ideas and potential treatment targets that circRNAs provide would be beneficial to research into the molecular mechanisms behind lung injury.


Asunto(s)
Lesión Pulmonar , MicroARNs , Humanos , ARN Circular/genética , Lesión Pulmonar/inducido químicamente , Lesión Pulmonar/genética , Lesión Pulmonar/terapia , Pulmón/metabolismo , MicroARNs/genética , MicroARNs/metabolismo , Biomarcadores/metabolismo
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA