Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 538
Filtrar
Más filtros

Banco de datos
País/Región como asunto
Tipo del documento
Intervalo de año de publicación
1.
Bioinformatics ; 40(2)2024 02 01.
Artículo en Inglés | MEDLINE | ID: mdl-38291952

RESUMEN

MOTIVATION: Spectral imaging is often used to observe different objects with multiple fluorescent labels to reveal the development of the biological event. As the number of observed objects increases, the spectral overlap between fluorophores becomes more serious, and obtaining a "pure" picture of each fluorophore becomes a major challenge. Here, we propose a blind spectral unmixing algorithm called BINGO (Blind unmixing via SVD-based Initialization Nmf with project Gradient descent and spare cOnstrain), which can extract all kinds of fluorophores more accurately from highly overlapping multichannel data, even if the spectra of the fluorophores are extremely similar or their fluorescence intensity varies greatly. RESULTS: BINGO can isolate up to 10 fluorophores from spectral imaging data for a single excitation. nine-color living HeLa cells were visualized distinctly with BINGO. It provides an important algorithmic tool for multiplex imaging studies, especially in intravital imaging. BINGO shows great potential in multicolor imaging for biomedical sciences. AVAILABILITY AND IMPLEMENTATION: The source code used for this paper is available with the test data at https://github.com/Xinyuan555/BINGO_unmixing.


Asunto(s)
Algoritmos , Programas Informáticos , Humanos , Microscopía Fluorescente/métodos , Células HeLa , Colorantes Fluorescentes
2.
Nat Chem Biol ; 19(11): 1309-1319, 2023 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-37248412

RESUMEN

With an eye toward expanding chemistries used for covalent ligand discovery, we elaborated an umpolung strategy that exploits the 'polarity reversal' of sulfur when cysteine is oxidized to sulfenic acid, a widespread post-translational modification, for selective bioconjugation with C-nucleophiles. Here we present a global map of a human sulfenome that is susceptible to covalent modification by members of a nucleophilic fragment library. More than 500 liganded sulfenic acids were identified on proteins across diverse functional classes, and, of these, more than 80% were not targeted by electrophilic fragment analogs. We further show that members of our nucleophilic fragment library can impair functional protein-protein interactions involved in nuclear oncoprotein transport and DNA damage repair. Our findings reveal a vast expanse of ligandable sulfenic acids in the human proteome and highlight the utility of nucleophilic small molecules in the fragment-based covalent ligand discovery pipeline, presaging further opportunities using non-traditional chemistries for targeting proteins.


Asunto(s)
Cisteína , Ácidos Sulfénicos , Humanos , Cisteína/metabolismo , Ligandos , Proteoma/metabolismo , Procesamiento Proteico-Postraduccional
3.
Proc Natl Acad Sci U S A ; 119(6)2022 02 08.
Artículo en Inglés | MEDLINE | ID: mdl-35074895

RESUMEN

The development of small-molecules targeting different components of SARS-CoV-2 is a key strategy to complement antibody-based treatments and vaccination campaigns in managing the COVID-19 pandemic. Here, we show that two thiol-based chemical probes that act as reducing agents, P2119 and P2165, inhibit infection by human coronaviruses, including SARS-CoV-2, and decrease the binding of spike glycoprotein to its receptor, the angiotensin-converting enzyme 2 (ACE2). Proteomics and reactive cysteine profiling link the antiviral activity to the reduction of key disulfides, specifically by disruption of the Cys379-Cys432 and Cys391-Cys525 pairs distal to the receptor binding motif in the receptor binding domain (RBD) of the spike glycoprotein. Computational analyses provide insight into conformation changes that occur when these disulfides break or form, consistent with an allosteric role, and indicate that P2119/P2165 target a conserved hydrophobic binding pocket in the RBD with the benzyl thiol-reducing moiety pointed directly toward Cys432. These collective findings establish the vulnerability of human coronaviruses to thiol-based chemical probes and lay the groundwork for developing compounds of this class, as a strategy to inhibit the SARS-CoV-2 infection by shifting the spike glycoprotein redox scaffold.


Asunto(s)
Amino Alcoholes/farmacología , Enzima Convertidora de Angiotensina 2/química , Antivirales/farmacología , Éteres Fenílicos/farmacología , Receptores Virales/química , SARS-CoV-2/efectos de los fármacos , Glicoproteína de la Espiga del Coronavirus/química , Compuestos de Sulfhidrilo/farmacología , Regulación Alostérica , Amino Alcoholes/química , Enzima Convertidora de Angiotensina 2/antagonistas & inhibidores , Enzima Convertidora de Angiotensina 2/genética , Enzima Convertidora de Angiotensina 2/metabolismo , Antivirales/química , Sitios de Unión , COVID-19/virología , Línea Celular , Disulfuros/antagonistas & inhibidores , Disulfuros/química , Disulfuros/metabolismo , Relación Dosis-Respuesta a Droga , Humanos , Simulación del Acoplamiento Molecular , Mucosa Nasal/efectos de los fármacos , Mucosa Nasal/metabolismo , Mucosa Nasal/virología , Oxidación-Reducción , Éteres Fenílicos/química , Unión Proteica , Conformación Proteica en Hélice alfa , Conformación Proteica en Lámina beta , Dominios y Motivos de Interacción de Proteínas , Receptores Virales/antagonistas & inhibidores , Receptores Virales/genética , Receptores Virales/metabolismo , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , SARS-CoV-2/genética , SARS-CoV-2/metabolismo , Glicoproteína de la Espiga del Coronavirus/antagonistas & inhibidores , Glicoproteína de la Espiga del Coronavirus/genética , Glicoproteína de la Espiga del Coronavirus/metabolismo , Compuestos de Sulfhidrilo/química , Tratamiento Farmacológico de COVID-19
4.
Biochem Biophys Res Commun ; 735: 150839, 2024 Oct 16.
Artículo en Inglés | MEDLINE | ID: mdl-39427375

RESUMEN

There is a potential link between autoimmune diseases and Epstein-Barr virus (EBV) infections, with EBV playing a substantial role in the onset of Sjögren's syndrome (SjS). Some EBV proteins could mimic host self-antigens post-infection, leading to molecular mimicry. This similarity may cause the immune system to attack its tissues mistakenly. Among the various proteins associated with EBV, nuclear antigen 1 (EBNA-1) is essential for the latent replication of infected cells and is prevalent in all EBV-related diseases. In the study, single-chain variable fragment (scFv) antibodies targeting EBNA-1 were isolated using phage display technology from a primary SjS patient who also had a chronic active EBV infection. The specific clones were enriched after panning, and the binding activity of selected scFvs targeting EBNA-1 was confirmed. Sequence analysis indicated that the scFvs exhibiting positive signals could be grouped into five clones, all of which used homologous heavy chain V regions derived from germline Vh4-39, and two types of light chain V regions stemming from germline Vλ1-44 and Vλ3-15. These scFvs were found to exhibit a high degree of somatic mutations, likely indicative of antigen selection. Of the scFvs, P1-3 demonstrated the strongest binding affinity to EBNA-1, exhibiting a determined value of 7.3 x 10-8 M, and showed cross-reactivity to the SjS associated La/SSB self-antigen. The experimental results combined with AlphaFold 3 predictions revealed a potential epitope for scFv P1-3 binding to EBNA-1. Additionally, scFv P1-3 could also cross-bind to the modeled structure of La/SSB. We inferred a possible structural correlation between EBNA-1 and La/SSB involving an X2AX6PG epitope motif. This research contributes to our understanding of the structural basis of the interactions between antibodies and EBNA-1, shedding light on the VH and VL gene usage of anti-EBNA-1 antibodies in EBV-infected SjS patients and the potential origins of autoantibodies.

5.
Opt Lett ; 49(18): 5167-5170, 2024 Sep 15.
Artículo en Inglés | MEDLINE | ID: mdl-39270256

RESUMEN

In this Letter, we utilize the speckle model to measure the average random scattering rate of fiber backscatter and analyze its dependence on length, yielding a linear fitting coefficient of 0.23 ppm/m for a PM980-XP fiber. We incorporate the temperature coupling effect into the model and validate the model's accuracy by examining the distribution of the change rate of the backscattering rate relative to the temperature and the amplitude spectral density of the backscattered power. Our findings demonstrate that the typical shoulder-shaped noise in interferometer experiments is limited by stray light, and the dependence of shoulder-shaped noise on the fiber length and temperature noise level is analyzed.

6.
Opt Lett ; 49(12): 3300-3303, 2024 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-38875605

RESUMEN

Optical path length (OPL) noise resulting from stray light significantly constrains interferometry displacement measurements in the low-frequency band. This paper presents an analytical model considering the presence of stray light in heterodyne laser interferometers. Due to the cyclic nonlinear coupling effect, there will be some special OPLs of stray light, minimizing the frequency-mixing impact to zero. Consequently, we propose a noise suppression scheme that locks the OPL of stray light at the zero coupling point. Therefore, we significantly enhanced the interference displacement measurement noise within the low-frequency band. Experimental results show that the interferometer achieves a displacement noise level lower than 6 pm/Hz1/2 covering 1 mHz.

7.
Chemistry ; 30(24): e202303912, 2024 Apr 25.
Artículo en Inglés | MEDLINE | ID: mdl-38319524

RESUMEN

Adsorption of metal-organic complexes on metallic surfaces to produce well-defined single site catalysts is a novel approach combining the advantages of homogeneous and heterogeneous catalysis. To avoid the "surface trans-effect" a dome-shaped molybdenum(0) tricarbonyl complex supported by an tolylazacalix[3](2,6)pyridine ligand is synthesized. This vacuum-evaporable complex both activates CO and reacts with molecular oxygen (O2) to form a Mo(VI) trioxo complex which in turn is capable of catalytically mediating oxygen transfer. The molybdenum tricarbonyl- and trioxo complexes are investigated in the solid state, in homogeneous solution and on noble metal surfaces (Cu, Au) employing a range of spectroscopic and analytical methods.

8.
BMC Cancer ; 24(1): 1277, 2024 Oct 15.
Artículo en Inglés | MEDLINE | ID: mdl-39407127

RESUMEN

BACKGROUND: Head and neck squamous cell carcinoma (HNSCC) is the sixth most prevalent malignancy worldwide, with high incidence and poor survival rates. RBP1 is highly expressed in several kinds of cancer and plays a potential prognostic factor. However, the relationship between RBP1 and HNSCC were analyzed based on The Cancer Genome Atlas (TCGA) database. MATERIALS AND METHODS: RBP1 expression and clinical information were obtained from the Cancer Genome Atlas (TCGA) database. Tumor tissue and adjacent normal tissue of 6 HNSCC patients were collected to analyze the RBP1 mRNA expression level by quantitative PCR. Cox regression analysis was used to evaluate the prognostic values of RBP1 and clinical data in HNSCC. A nomogram was also established to predict the impact of RBP1 on prognosis based on Cox multivariate results. The methylation level of RBP1 in HNSC and its prognosis were analyzed in UALACN and MethSurv. Finally, the potential biological functions of RBP1 were investigated using gene set enrichment analysis (GSEA) and single sample GSEA (ssGSEA). RESULTS: The mRNA expression levels of RBP1 were highly expressed in HNSCC tissue. The Cox analyses demonstrate that highly-expressed RBP1 is an independent prognosis marker(P < 0.05). ROC curve analysis showed that performances of RBP1 (area under the ROC curve: 0.887, sensitivity: 84.1%, specificity: 79.9%). The methylation was increased in HNSCC patients compared with normal subjects(P < 0.05) and was associated with better prognosis at sites cg06208339, cg12298268, cg12497564, cg15288618, cg20532370, cg23448348. Additionally, RBP1 expression is mildly associated with immune cell infiltration and immunological checkpoints. CONCLUSION: RBP1 is overexpressed and associated with poor patient prognosis in head and neck squamous cell carcinoma.


Asunto(s)
Biomarcadores de Tumor , Metilación de ADN , Neoplasias de Cabeza y Cuello , Carcinoma de Células Escamosas de Cabeza y Cuello , Humanos , Pronóstico , Carcinoma de Células Escamosas de Cabeza y Cuello/genética , Carcinoma de Células Escamosas de Cabeza y Cuello/mortalidad , Carcinoma de Células Escamosas de Cabeza y Cuello/metabolismo , Carcinoma de Células Escamosas de Cabeza y Cuello/patología , Masculino , Femenino , Neoplasias de Cabeza y Cuello/genética , Neoplasias de Cabeza y Cuello/metabolismo , Neoplasias de Cabeza y Cuello/mortalidad , Neoplasias de Cabeza y Cuello/patología , Biomarcadores de Tumor/genética , Biomarcadores de Tumor/metabolismo , Persona de Mediana Edad , Regulación Neoplásica de la Expresión Génica , Proteínas Plasmáticas de Unión al Retinol/genética , Proteínas Plasmáticas de Unión al Retinol/metabolismo , Nomogramas , Anciano , ARN Mensajero/genética , ARN Mensajero/metabolismo , Proteínas Celulares de Unión al Retinol
9.
Nat Chem Biol ; 18(8): 904-912, 2022 08.
Artículo en Inglés | MEDLINE | ID: mdl-35864333

RESUMEN

Chemoproteomics has emerged as a key technology to expand the functional space in complex proteomes for probing fundamental biology and for discovering new small-molecule-based therapies. Here we report a modification-centric computational tool termed pChem to provide a streamlined pipeline for unbiased performance assessment of chemoproteomic probes. The pipeline starts with an experimental setting for isotopically coding probe-derived modifications that can be automatically recognized by pChem, with masses accurately calculated and sites precisely localized. pChem exports on-demand reports by scoring the profiling efficiency, modification homogeneity and proteome-wide residue selectivity of a tested probe. The performance and robustness of pChem were benchmarked by applying it to eighteen bioorthogonal probes. These analyses reveal that the formation of unexpected probe-derived modifications can be driven by endogenous reactive metabolites (for example, bioactive aldehydes and glutathione). pChem is a powerful and user-friendly tool that aims to facilitate the development of probes for the ever-growing field of chemoproteomics.


Asunto(s)
Aldehídos , Proteoma , Aldehídos/química , Proteoma/metabolismo
10.
Chemphyschem ; 25(5): e202300693, 2024 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-38183359

RESUMEN

Lithium-sulfur batteries (LSBs) are considered as the development direction of the new generation energy storage system due to their high energy density and low cost. The slow redox kinetics of sulfur and the shuttle effect of lithium polysulfide (LiPS) are considered to be the main obstacles to the practical application of LSBs. Transition-metal sulfide as the cathode host can improve the Li-S redox chemistry. However, there has been no investigation of the application of FeS2 host in Li-S redox chemistry. Applying the first-principles calculations, we investigated the formation energy, band gap, Li+ diffusion, adsorption energy, catalytic performance and Li2 S decomposition barrier of FeAx S2-x (A=N, P, O, Se; x=0, 0.125, 0.25, 0.375) to explore the Li-S redox chemistry and finally select excellent host material. FeA0.25 S1.75 (A=P, Se) has a low Li+ diffusion barrier and superior electronic conductivity. FeO0.25 S1.75 is more favorable for LiPS adsorption, followed by FeP0.25 S1.75 . FeP0.25 S1.75 (001) shows a low overpotential for the Li-S redox chemistry. In summary, FeP0.25 S1.75 has more application potential in LSBs due to its physical and chemical properties, followed by FeSe0.25 S1.75 . This work provides theoretical guidance for the design and selection of the sulfur cathode host materials in LSBs.

11.
Inorg Chem ; 63(17): 7746-7753, 2024 Apr 29.
Artículo en Inglés | MEDLINE | ID: mdl-38609344

RESUMEN

A novel two-dimensional (2D) Hofmann-type coordination polymer, {FeII(PyHbim)2[Pd(CN)4]}·2CH3OH [1·2CH3OH, PyHbim = 2-(4-pyridyl)benzimidazole], has been synthesized, which can undergo a spontaneous guest exchange, transforming to 1·2H2O in a single-crystal-to-single-crystal (SCSC) manner, shifting from orthorhombic Cmmm to monoclinic C2/m involving the displacement of 2D layers. The solvent-induced SCSC transformation process was reversible and verified through powder X-ray diffraction (PXRD) and single-crystal X-ray crystallography analyses. Both 1·2CH3OH and 1·2H2O exhibit complete and abrupt spin crossover (SCO) behaviors in two steps, while their SCO temperature ranges drastically shift by ca.100 K, spanning room temperature, owing to different intermolecular interactions resulting from diverse interlayer packing manners and host-guest interactions. Besides, a structural phase transition is observed in 1·2CH3OH, contributing to the two-step spin transition.

12.
Phys Chem Chem Phys ; 26(3): 2249-2259, 2024 Jan 17.
Artículo en Inglés | MEDLINE | ID: mdl-38165279

RESUMEN

Lithium-sulfur batteries (LSBs) are one of the most promising energy storage devices with high energy density. However, their application and commercialization are hampered by the slow Li-S redox chemistry. Fe0.875M0.125S2 (M = Ti, V), as the sulfur cathode host, enhances the Li-S redox chemistry. FeS2 with Pa3̄ is transformed into Li2FeS2 with P3̄m1 after discharge. The structure changes and physicochemical properties during Fe0.875M0.125S2 discharge process are further investigated to screen out the sulfur cathode host materials with the best comprehensive properties. The discharge structure of Fe0.875M0.125S2 is verified by the thermodynamic stability of Li-deficient phases, voltage and capacity based on Monte Carlo methods. Fe0.875M0.125S2 with Pa3̄ is transformed into Li2Fe0.875M0.125S2 with P3̄m1 after discharge. Using the first-principles calculations, the physicochemical properties of Li2Fe0.875M0.125S2 are systematically investigated, including the formation energy, voltage, theoretical capacity, electrical conductivity, Li+ diffusion, catalytic performance and Li2S oxidation decomposition. The average redox voltage of Li2Fe0.875V0.125S2 is higher than that of Li2Fe0.875Ti0.125S2. Li2Fe0.875M0.125S2 shows metallic properties. Li2Fe0.875V0.125S2 is more beneficial to the reduction reaction of Li2S2 and Li2S oxidation decomposition. Fe0.875V0.125S2 has more potential as the sulfur cathode host than Fe0.875Ti0.125S2 in LSBs. A new strategy for the selection of the sulfur cathode host material for LSBs is provided by this work.

13.
Acta Pharmacol Sin ; 2024 Sep 23.
Artículo en Inglés | MEDLINE | ID: mdl-39313515

RESUMEN

Acetaminophen (APAP) overdose-induced acute liver injury (ALI) is characterized by extensive oxidative stress, and the clinical interventions for this adverse effect remain limited. Astilbin is an active compound found in the rhizome of Smilax glabra Roxb. with anti-inflammatory and antioxidant activities. Due to its low oral bioavailability, astilbin can accumulate in the intestine, which provides a basis for the interaction between astilbin and gut microbiota (GM). In the present study we investigated the protective effects of astilbin against APAP-induced ALI by focusing on the interaction between astilbin and GM. Mice were treated with astilbin (50 mg·kg-1·d-1, i.g.) for 7 days. After the last administration of astilbin for 2 h, the mice received APAP (300 mg/kg, i.g.) to induce ALI. We showed that oral administration of astilbin significantly alleviated APAP-induced ALI by altering the composition of GM and enriching beneficial metabolites including hydroxytyrosol (HT). GM depletion using an "antibiotics cocktail" or paraoral administration of astilbin abolished the hepatoprotective effects of astilbin. On the other hand, administration of HT (10 mg/kg, i.g.) caused similar protective effects in APAP-induced ALI mice. Transcriptomic analysis of the liver tissue revealed that HT inhibited reactive oxygen species and inflammation-related signaling in APAP-induced ALI; HT promoted activation of the Nrf2 signaling pathway to combat oxidative stress following APAP challenge in a sirtuin-6-dependent manner. These results highlight that oral astilbin ameliorates APAP-induced ALI by manipulating the GM and metabolites towards a more favorable profile, and provide an alternative therapeutic strategy for alleviating APAP-induced ALI.

14.
Zhongguo Zhong Yao Za Zhi ; 49(11): 2940-2946, 2024 Jun.
Artículo en Zh | MEDLINE | ID: mdl-39041153

RESUMEN

The chemical constituents from Leucas ciliata belonging to Leucas genus in Lamiaceae were systematically explored by silica gel column chromatography, ODS column chromatography, Sephadex LH-20 gel column chromatography, and preparative high performance liquid chromatography, and seventeen phenolic acids were isolated. The chemical structures of the compounds were identified by their physicochemical properties, spectroscopic data, and literature. They were 4-hydroxyphenethyl ethyl succinate(1), 4-hydroxyphenethyl methyl succinate(2), 2-(4-hydroxyphenyl) ethyl acetate(3), p-hydroxyphenylethyl anisate(4), cassia cis-trans diphenylpropanoid(5), p-coumaric acid(6), 3,4-dihydroxybenzenepropionic acid methyl ester(7), caffeic acid(8), trans-p-hydroxyl ethyl cinnamate(9), methyl p-hydroxybenzeneacetate(10), 4-hydroxyphenethyl alcohol(11), syringic acid(12), vanillin(13), protocatechuic acid(14), salicylic acid(15), p-hydroxybenzaldehyde(16), and diorcinol(17). Among them, compound 1 was new, and compounds 2-10, 12, 14, and 16-17 were isolated from the plants belonging to Leucas genus for the first time. All compounds were obtained from L. ciliata for the first time. The anti-inflammatory activity of compounds 1-17 on NO production in lipopolysaccharide(LPS)-induced mouse leukemia cells of monocyte macrophage(RAW264. 7) cells was evaluated. The results showed that compounds 5, 7, and 9 exhibited significant anti-inflammatory activity, with IC50values of(10. 14±0. 36)-(21. 17±0. 11) µmol·L~(-1).


Asunto(s)
Antiinflamatorios , Hidroxibenzoatos , Antiinflamatorios/farmacología , Antiinflamatorios/química , Hidroxibenzoatos/química , Hidroxibenzoatos/farmacología , Animales , Ratones , Células RAW 264.7 , Lamiaceae/química , Medicamentos Herbarios Chinos/química , Medicamentos Herbarios Chinos/farmacología , Estructura Molecular , Óxido Nítrico , Macrófagos/efectos de los fármacos
15.
Biochem Biophys Res Commun ; 680: 161-170, 2023 11 05.
Artículo en Inglés | MEDLINE | ID: mdl-37741263

RESUMEN

Studies have shown that the high expression of EphA4 in gastric cancer tissues may correlate with unfavorable clinical pathological characteristics. Therefore, EphA4 may be an effective target for treating gastric cancer in addition to HER-2/neu. In this study, generated scFv S3 can bind endogenous EphA4 of gastric cancer cells and has significant membrane staining. Additionally, scFv S3 binding to EphA4 inhibits the growth and migration of cancer cells and the growth induction that ephrinA1 generates in gastric cancer cells. We found that EphA4 molecules may degrade through antibody treatment of cells, and the increase in LAMP1 and LAMP2 indicates that lysosome is involved in the degradation. The scFv S3 administration leads to the signals pAKT, pERK, and pSTAT3 decrease in cancer cells. The xenograft model of HER-2/neu low expressing gastric cancer cell SNU-16 exhibits better therapeutic effects by scFv S3 than trastuzumab scFv. The scFv S3 administration in vivo can degrade EphA4 molecules in tumor tissues, decreasing Ki67 and increasing cleaved C3 molecule expression. Furthermore, we identified and validated that scFv S3 generates essential ionic bonding with R162 on EphA4. The antibody may provide effective treatment for patients with gastric cancer and abnormal activation or overexpression of EphA4 signaling.


Asunto(s)
Anticuerpos de Cadena Única , Neoplasias Gástricas , Humanos , Transducción de Señal , Neoplasias Gástricas/tratamiento farmacológico , Anticuerpos de Cadena Única/farmacología , Animales
16.
Biochem Biophys Res Commun ; 688: 149214, 2023 12 25.
Artículo en Inglés | MEDLINE | ID: mdl-37951154

RESUMEN

Pancreatic adenocarcinoma, a highly aggressive form of cancer with a poor prognosis, necessitates the development of innovative treatment strategies. Our prior research showcased the growth-inhibiting effects of the anti-EphA2 antibody drug hSD5 on pancreatic cancer tumors. This antibody targets and induces the degradation of the EphA2 receptor while also prompting the antibody's internalization. A deeper dive into the hSD5 Fab crystallographic structure and docking studies revealed that hSD5's CDRH3 drives the primary interaction between hSD5 and the EphA2 active site. In this study, we developed a novel antibody-drug conjugate (ADC)-the auristatin-based hSD5-vedotin specifically targeting EphA2 in pancreatic cancer cells. This ADC aims at the tumor-specific antigen EphA2, triggering endocytosis and releasing the conjugated payload molecule Monomethyl auristatin E (MMAE), amplifying the tumor-killing effect. Upon cellular entry, hSD5-vedotin demonstrated an impressive tumor-killing response, inhibiting tumor cell growth and promoting apoptosis even at lower antibody concentrations. In a pancreatic cancer xenograft animal model, hSD5-vedotin showcased the potential to suppress tumor growth entirely. Notably, potential immune resistance responses were also observed in recurrent pancreatic cancer tumors. Our empirical results underscore the possibility of developing hSD5-vedotin further, which we anticipate will have a broader and more potent therapeutic impact on pancreatic cancer and other EphA2-related cancers.


Asunto(s)
Adenocarcinoma , Inmunoconjugados , Neoplasias Pancreáticas , Animales , Humanos , Inmunoconjugados/farmacología , Inmunoconjugados/uso terapéutico , Inmunoconjugados/química , Neoplasias Pancreáticas/patología , Adenocarcinoma/tratamiento farmacológico , Línea Celular Tumoral , Recurrencia Local de Neoplasia , Ensayos Antitumor por Modelo de Xenoinjerto , Neoplasias Pancreáticas
17.
Plant Cell ; 32(4): 1000-1017, 2020 04.
Artículo en Inglés | MEDLINE | ID: mdl-32024687

RESUMEN

Hydrogen sulfide (H2S) is a gaseous signaling molecule that regulates diverse cellular signaling pathways through persulfidation, which involves the post-translational modification of specific Cys residues to form persulfides. However, the mechanisms that underlie this important redox-based modification remain poorly understood in higher plants. We have, therefore, analyzed how protein persulfidation acts as a specific and reversible signaling mechanism during the abscisic acid (ABA) response in Arabidopsis (Arabidopsis thaliana). Here we show that ABA stimulates the persulfidation of l-CYSTEINE DESULFHYDRASE1, an important endogenous H2S enzyme, at Cys44 and Cys205 in a redox-dependent manner. Moreover, sustainable H2S accumulation drives persulfidation of the NADPH oxidase RESPIRATORY BURST OXIDASE HOMOLOG PROTEIN D (RBOHD) at Cys825 and Cys890, enhancing its ability to produce reactive oxygen species. Physiologically, s-persulfidation-induced RBOHD activity is relevant to ABA-induced stomatal closure. Together, these processes form a negative feedback loop that fine-tunes guard cell redox homeostasis and ABA signaling. These findings not only expand our current knowledge of H2S function in the context of guard cell ABA signaling, but also demonstrate the presence of a rapid signal integration mechanism involving specific and reversible redox-based post-translational modifications that occur in response to changing environmental conditions.


Asunto(s)
Ácido Abscísico/metabolismo , Proteínas de Arabidopsis/metabolismo , Arabidopsis/citología , Arabidopsis/metabolismo , Cistationina gamma-Liasa/metabolismo , NADPH Oxidasas/metabolismo , Estomas de Plantas/citología , Transducción de Señal , Sulfuros/metabolismo , Cisteína/metabolismo , Sulfuro de Hidrógeno/metabolismo , Modelos Biológicos , Oxidación-Reducción , Especies Reactivas de Oxígeno/metabolismo
18.
Opt Lett ; 48(6): 1518-1521, 2023 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-36946967

RESUMEN

Two-photon excitation fluorescence (TPEF) microscopy has evolved into a versatile tool in biological research. However, the multiplexing capability of TPEF microscopy is limited by the narrow spectral bandwidth of the light source. In this study, we apply a photonic crystal fiber in TPEF microscopy to broaden the excitation source bandwidth. We tuned the spectral window using a spatial light modulator as a programmable diffraction grating that was placed behind a prism pair. In addition, we combined a grating pair to compensate for dispersion to improve the two-photon excitation efficiency. The combination of a broad spectrum and a programmable grating enabled fast spectral window tuning rate on a time scale of tens of milliseconds. We demonstrate the performance of our method by imaging live B16 cells labeled with four emission spectrum overlapped fluorescent proteins.

19.
Brain Behav Immun ; 108: 98-117, 2023 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-36427810

RESUMEN

Growing evidence suggests the involvement of the microbiota-gut-brain axis in cognitive impairment induced by sleep deprivation (SD), however how the microbiota-gut-brain axis work remains elusive. Here, we discovered that chronic SD induced intestinal dysbiosis, activated NLRP3 inflammasome in the colon and brain, destructed intestinal/blood-brain barrier, and impaired cognitive function in mice. Transplantation of "SD microbiota" could almost mimic the pathological and behavioral changes caused by chronic SD. Furthermore, all the behavioral and pathological abnormalities were practically reversed in chronic sleep-deprived NLRP3-/- mice. Regional knockdown NLRP3 expression in the gut and hippocampus, respectively. We observed that down-regulation of NLRP3 in the hippocampus inhibited neuroinflammation, and ameliorated synaptic dysfunction and cognitive impairment induced by chronic SD. More intriguingly, the down-regulation of NLRP3 in the gut protected the intestinal barrier, attenuated the levels of peripheral inflammatory factors, down-regulated the expression of NLRP3 in the brain, and improved cognitive function in chronic SD mice. Our results identified gut microbiota as a driver in chronic SD and highlighted the NLRP3 inflammasome as a key regulator within the microbiota-gut-brain axis.


Asunto(s)
Disfunción Cognitiva , Inflamasomas , Ratones , Animales , Inflamasomas/metabolismo , Proteína con Dominio Pirina 3 de la Familia NLR/metabolismo , Privación de Sueño/complicaciones , Disbiosis/inducido químicamente , Hipocampo/metabolismo , Disfunción Cognitiva/metabolismo , Intestinos
20.
Cardiology ; 148(2): 138-149, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36596284

RESUMEN

INTRODUCTION: Data on first-line ablation treatment for patients with symptomatic atrial fibrillation (AF) are scarce. This study indirectly compared the efficacy and safety of cryoballoon ablation (CBA) versus radiofrequency ablation (RFA) as initial therapy for symptomatic AF. METHODS: We searched the EMBASE, PubMed, Cochrane Library, and ClinicalTrials.gov databases for randomized controlled trials (RCTs) that compared CBA or RFA with antiarrhythmic drugs (AADs) as first-line treatment for AF from the time of database establishment up to December 2021. The odds ratio (OR) with a 95% confidence interval (CI) was used as a measure of the treatment effect. RESULTS: Six RCTs (3 CBA, 3 RFA) that enrolled a total of 1,215 patients were included in this analysis. There were no significant differences in atrial arrhythmia (AA) (OR 0.993, 95% CI: 0.602-1.638), symptomatic AA (OR 0.638, 95% CI: 0.344-1.182), or serious adverse events (OR 1.474, 95% CI: 0.404-5.376) between the two ablation techniques. The incidences of additional CBA therapy (OR 2.693, 95% CI: 1.277-5.681) and patients who crossed over to AAD therapy (OR 0.345, 95% CI: 0.179-0.664) in the CBA group were significantly lower than those in the RFA group. CONCLUSION: Among patients with paroxysmal AF receiving initial therapy, CBA and RFA share a similar efficacy and safety profile. When pulmonary vein isolation is performed by CBA, study crossover and the need for additional ablation are substantially lower.


Asunto(s)
Fibrilación Atrial , Ablación por Catéter , Criocirugía , Ablación por Radiofrecuencia , Humanos , Criocirugía/métodos , Resultado del Tratamiento , Metaanálisis en Red , Ablación por Catéter/métodos , Ensayos Clínicos Controlados Aleatorios como Asunto , Recurrencia
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA