Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 257
Filtrar
Más filtros

Bases de datos
País/Región como asunto
Tipo del documento
Intervalo de año de publicación
1.
Mol Cell ; 73(1): 22-35.e6, 2019 01 03.
Artículo en Inglés | MEDLINE | ID: mdl-30527665

RESUMEN

Aberrant expression of programmed death ligand-1 (PD-L1) in tumor cells promotes cancer progression by suppressing cancer immunity. The retinoblastoma protein RB is a tumor suppressor known to regulate the cell cycle, DNA damage response, and differentiation. Here, we demonstrate that RB interacts with nuclear factor κB (NF-κB) protein p65 and that their interaction is primarily dependent on CDK4/6-mediated serine-249/threonine-252 (S249/T252) phosphorylation of RB. RNA-seq analysis shows a subset of NF-κB pathway genes including PD-L1 are selectively upregulated by RB knockdown or CDK4/6 inhibitor. S249/T252-phosphorylated RB inversely correlates with PD-L1 expression in patient samples. Expression of a RB-derived S249/T252 phosphorylation-mimetic peptide suppresses radiotherapy-induced upregulation of PD-L1 and augments therapeutic efficacy of radiation in vivo. Our findings reveal a previously unrecognized tumor suppressor function of hyperphosphorylated RB in suppressing NF-κB activity and PD-L1 expression and suggest that the RB-NF-κB axis can be exploited to overcome cancer immune evasion triggered by conventional or targeted therapies.


Asunto(s)
Antígeno B7-H1/metabolismo , Neoplasias de la Próstata/metabolismo , Proteína de Retinoblastoma/metabolismo , Factor de Transcripción ReIA/metabolismo , Escape del Tumor , Animales , Antineoplásicos Inmunológicos/farmacología , Antígeno B7-H1/antagonistas & inhibidores , Antígeno B7-H1/genética , Antígeno B7-H1/inmunología , Quimioradioterapia/métodos , Quinasa 4 Dependiente de la Ciclina/metabolismo , Quinasa 6 Dependiente de la Ciclina/metabolismo , Regulación Neoplásica de la Expresión Génica , Células HEK293 , Humanos , Masculino , Ratones Endogámicos C57BL , Ratones Endogámicos NOD , Ratones Noqueados , Ratones SCID , Células PC-3 , Fosforilación , Neoplasias de la Próstata/genética , Neoplasias de la Próstata/inmunología , Neoplasias de la Próstata/terapia , Unión Proteica , Dominios y Motivos de Interacción de Proteínas , Tolerancia a Radiación , Proteína de Retinoblastoma/genética , Proteína de Retinoblastoma/inmunología , Transducción de Señal , Factor de Transcripción ReIA/genética , Factor de Transcripción ReIA/inmunología , Ensayos Antitumor por Modelo de Xenoinjerto
2.
Pharmacol Rev ; 75(4): 758-788, 2023 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-36918260

RESUMEN

Parkinson's disease (PD) is a neurodegenerative disorder characterized by selective loss of dopaminergic neurons in the substantia nigra pars compacta (SNpc) region of the midbrain. The loss of neurons results in a subsequent reduction of dopamine in the striatum, which underlies the core motor symptoms of PD. To date, there are no effective treatments to stop, slow, or reverse the pathologic progression of dopaminergic neurodegeneration. This unfortunate predicament is because of the current early stages in understanding the biologic targets and pathways involved in PD pathogenesis. Ion channels have become emerging targets for new therapeutic development for PD due to their essential roles in neuronal function and neuroinflammation. Potassium channels are the most prominent ion channel family and have been shown to be critically important in PD pathology because of their roles in modulating neuronal excitability, neurotransmitter release, synaptic transmission, and neuroinflammation. In this review, members of the subfamilies of voltage-gated K+ channels, inward rectifying K+ channels, and Ca2+-activated K+ channels are described. Evidence of the role of these channels in PD etiology is discussed together with the latest views on related pathologic mechanisms and their potential as biologic targets for developing neuroprotective drugs for PD. SIGNIFICANCE STATEMENT: Parkinson's disease (PD) is the second most common neurodegenerative disorder, featuring progressive degeneration of dopaminergic neurons in the midbrain. It is a multifactorial disease involving multiple risk factors and complex pathobiological mechanisms. Mounting evidence suggests that ion channels play vital roles in the pathogenesis and progression of PD by regulating neuronal excitability and immune cell function. Therefore, they have become "hot" biological targets for PD, as demonstrated by multiple clinical trials of drug candidates targeting ion channels for PD therapy.


Asunto(s)
Productos Biológicos , Enfermedad de Parkinson , Humanos , Enfermedad de Parkinson/tratamiento farmacológico , Enfermedad de Parkinson/metabolismo , Canales de Potasio/metabolismo , Canales de Potasio/uso terapéutico , Enfermedades Neuroinflamatorias , Canales Iónicos/metabolismo , Neuronas Dopaminérgicas/metabolismo , Neuronas Dopaminérgicas/patología , Productos Biológicos/uso terapéutico
3.
Artículo en Inglés | MEDLINE | ID: mdl-38871183

RESUMEN

BACKGROUND: Inhalable biologics represent a promising approach to improve the efficacy and safety of asthma treatment. Although several mAbs targeting IL-4 receptor α chain (IL-4Rα) have been approved or are undergoing clinical trials, the development of inhalable mAbs targeting IL-4Rα presents significant challenges. OBJECTIVE: Capitalizing on the distinctive advantages of nanobodies (Nbs) in maintaining efficacy during storage and administration, we sought to develop a novel inhalable IL-4Rα Nb for effectively treating asthma. METHODS: Three IL-4Rα immunized Nb libraries were used to generate specific and functional IL-4Rα Nbs. LQ036, a bivalent Nb comprising 2 HuNb103 units, was constructed with a high affinity and specificity for human IL-4Rα. The efficacy, pharmacokinetics, and safety of inhaled LQ036 were evaluated in B-hIL4/hIL4RA humanized mice. RESULTS: LQ036 inhibited secreted embryonic alkaline phosphatase reporter activity, inhibited TF-1 cell proliferation, and suppressed phosphorylated signal transducer and activator of transduction 6 in T cells from patients with asthma. Crystal structure analysis revealed a binding region similar to dupilumab but with higher affinity, leading to better efficacy in blocking the signaling pathway. HuNb103 competed with IL-4 and IL-13 for IL-4Rα binding. Additionally, LQ036 significantly inhibited ovalbumin-specific IgE levels in serum, CCL17 levels in bronchoalveolar lavage fluid, bronchial mucous cell hyperplasia, and airway goblet cell hyperplasia in B-hIL4/hIL4RA humanized mice. Inhaled LQ036 exhibited favorable pharmacokinetics, safety, and tissue distribution, with higher concentrations observed in the lungs and bronchi. CONCLUSIONS: These findings from preclinical studies establish the safety and efficacy of inhaled LQ036, underscoring its potential as a pioneering inhalable biologic therapy for asthma.

4.
Chembiochem ; 25(5): e202300790, 2024 03 01.
Artículo en Inglés | MEDLINE | ID: mdl-38242853

RESUMEN

Transient receptor potential melastatin 2 (TRPM2) is a calcium-permeable, nonselective cation channel with a widespread distribution throughout the body. It is involved in many pathological and physiological processes, making it a potential therapeutic target for various diseases, including Alzheimer's disease, Parkinson's disease, and cancers. New analytical techniques are beneficial for gaining a deeper understanding of its involvement in disease pathogenesis and for advancing the drug discovery for TRPM2-related diseases. In this work, we present the application of collision-induced affinity selection mass spectrometry (CIAS-MS) for the direct identification of ligands binding to TRPM2. CIAS-MS circumvents the need for high mass detection typically associated with mass spectrometry of large membrane proteins. Instead, it focuses on the detection of small molecules dissociated from the ligand-protein-detergent complexes. This affinity selection approach consolidates all affinity selection steps within the mass spectrometer, resulting in a streamlined process. We showed the direct identification of a known TRPM2 ligand dissociated from the protein-ligand complex. We demonstrated that CIAS-MS can identify binding ligands from complex mixtures of compounds and screened a compound library against TRPM2. We investigated the impact of voltage increments and ligand concentrations on the dissociation behavior of the binding ligand, revealing a dose-dependent relationship.


Asunto(s)
Enfermedad de Alzheimer , Canales Catiónicos TRPM , Humanos , Ligandos , Descubrimiento de Drogas , Biblioteca de Genes
5.
Cardiovasc Diabetol ; 23(1): 7, 2024 01 03.
Artículo en Inglés | MEDLINE | ID: mdl-38172903

RESUMEN

BACKGROUND: The triglyceride-glucose (TyG) index is a reliable surrogate marker of insulin resistance and previous studies have confirmed the association of TyG index with incident chronic kidney disease (CKD). However, the impact of longitudinal patterns of TyG index on CKD risk among non-diabetic population is still unknown. Therefore, this study aimed to investigate the association of longitudinal patterns of TyG index with incident CKD among non-diabetic population. METHODS: A total of 5484 non-diabetic participants who underwent one health examination per year from 2015 to 2017 were included in this prospective study. TyG index variability and cumulative TyG index were calculated to assess the longitudinal patterns of TyG index. Cox proportional hazard models were performed to estimate the association of TyG index variability or cumulative TyG index with incident CKD. RESULTS: During a median of 3.82 years follow-up, 879 participants developed CKD. Compared with participants in the lowest quartile, the hazard ratio (HR) and 95% confidence interval (CI) of incident CKD were 1.772 (95% CI: 1.453, 2.162) for the highest TyG index variability quartile and 2.091 (95% CI: 1.646, 2.655) for the highest cumulative TyG index quartile in the fully adjusted models. The best discrimination and reclassification improvement were observed after adding baseline TyG, TyG index variability and cumulative TyG index to the clinical risk model for CKD. CONCLUSIONS: Both TyG index variability and cumulative TyG index can independently predict incident CKD among non-diabetic population. Monitoring longitudinal patterns of TyG index may assist with prediction and prevention of incident CKD.


Asunto(s)
Glucosa , Insuficiencia Renal Crónica , Humanos , Incidencia , Estudios Prospectivos , Insuficiencia Renal Crónica/diagnóstico , Insuficiencia Renal Crónica/epidemiología , Triglicéridos , Glucemia , Factores de Riesgo , Biomarcadores
6.
J Org Chem ; 89(6): 3941-3953, 2024 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-38421294

RESUMEN

An efficient synthetic method for constructing 2,3- and 2,4-disubstituted pyrimidio[1,2-b]indazole skeletons through I2-DMSO-mediated and substrate-controlled regioselective [4 + 2] cyclization is reported. The reaction conditions are mild, its operation is simple, and the substrate scope is wide. More than 60 pyrimidio[1,2-b]indazole derivatives have been synthesized, providing a new methodology for constructing related molecules and potentially enriching bioactive-molecule libraries.

7.
Environ Res ; 246: 118157, 2024 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-38199468

RESUMEN

Halomonas spp. are moderately halophilic bacteria with the ability to tolerate various heavy metals. However, the role of basic cellular metabolism, particularly amino acid metabolism, has not been investigated in Halomonas spp. under excess Mn(Ⅱ). The strain Halomonas sp. MNB13 was isolated from a deep-sea ferromanganese nodule and can tolerate 80 mM Mn(Ⅱ). To comprehensively explore the mechanisms underlying its resistance to excess Mn(Ⅱ), we conducted a comparative proteome analysis. The data revealed that both 10 mM and 50 mM Mn(Ⅱ) significantly up-regulated the expression of proteins involved in Mn(Ⅱ) transport (MntE), oxidative stress response (alkyl hydroperoxide reductase and the Suf system), and amino acid metabolism (arginine, cysteine, methionine, and phenylalanine). We further investigated the role of cysteine metabolism in Mn(Ⅱ) resistance by examining the function of its downstream product, H2S. Consistent with the up-regulation of cysteine desulfurase, we detected an elevated level of H2S in Halomonas sp. MNB13 cells under Mn(Ⅱ) stress, along with increased intracellular levels of H2O2 and O2•-. Upon exogenous addition of H2S, we observed a significant restoration of the growth of Halomonas sp. MNB13. Moreover, we identified decreased intracellular levels of H2O2 and O2•- in MNB13 cells, which coincided with a decreased formation of Mn-oxides during cultivation. In contrast, in cultures containing NaHS, the residual Mn(Ⅱ) levels were higher than in cultures without NaHS. Therefore, H2S improves Mn(Ⅱ) tolerance by eliminating intracellular reactive oxygen species rather than decreasing Mn(Ⅱ) concentration in solution. Our findings indicate that cysteine metabolism, particularly the intermediate H2S, plays a pivotal role in Mn(Ⅱ) resistance by mitigating the damage caused by reactive oxygen species. These findings provide new insights into the amino acid mechanisms associated with Mn(Ⅱ) resistance in bacteria.


Asunto(s)
Halomonas , Proteómica , Halomonas/metabolismo , Especies Reactivas de Oxígeno/metabolismo , Cisteína/metabolismo , Peróxido de Hidrógeno
8.
Nutr Metab Cardiovasc Dis ; 34(2): 334-342, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38000992

RESUMEN

BACKGROUND AND AIMS: In prospective studies, there is limited evidence of the association between inflammation and hypertension. We aimed to explore the relationship between systemic immune inflammatory index (SII)/systemic inflammatory response index (SIRI) and hypertension in a prospective cohort study to identify the best inflammatory cell markers that predict hypertension. METHODS AND RESULTS: This study was conducted in a functional community cohort in Beijing. In 2015, a total of 6003 individuals without hypertension were recruited and followed up until 2021. Using a restriction cubic spline with baseline SII/SIRI as a continuous variable, the dose-response relationship between hypertension and SII/SIRI was explored. Logistic regression was used to analyze the correlation between hypertension and SII/SIRI trajectory groups. At a mean follow-up of 6 years, 970 participants developed hypertension. SII showed a significant nonlinear dose-response relationship with hypertension (P < 0.05). Higher SII/SIRI was associated with an increased risk of hypertension (SII: RR = 1.003, 95%CI: 1.001-1.004; SIRI: RR = 1.228, 95%CI: 1.015-1.486). Both SII and SIRI were more predictive in males than females (SII: 0.698 vs. 0.695; SIRI: 0.686 vs. 0.678). CONCLUSION: Both systemic immune inflammatory index (SII) and systemic inflammatory response Index (SIRI) independently increased the risk of hypertension, and both were effective inflammatory cell indicators that predict the risk of hypertension.


Asunto(s)
Hipertensión , Femenino , Masculino , Humanos , Estudios de Cohortes , Estudios Prospectivos , Beijing/epidemiología , Hipertensión/diagnóstico , Hipertensión/epidemiología , Síndrome de Respuesta Inflamatoria Sistémica
9.
J Nanobiotechnology ; 22(1): 256, 2024 May 16.
Artículo en Inglés | MEDLINE | ID: mdl-38755613

RESUMEN

BACKGROUND: Gastric cancer represents a highly lethal malignancy with an elevated mortality rate among cancer patients, coupled with a suboptimal postoperative survival prognosis. Nectin-4, an overexpressed oncological target for various cancers, has been exploited to create antibody-drug conjugates (ADCs) to treat solid tumors. However, there is limited research on Nectin-4 ADCs specifically for gastric cancer, and conventional immunoglobulin G (IgG)-based ADCs frequently encounter binding site barriers. Based on the excellent tumor penetration capabilities inherent in nanobodies (Nbs), we developed Nectin-4-targeting Nb drug conjugates (NDCs) for the treatment of gastric cancer. RESULTS: An immunized phage display library was established and employed for the selection of Nectin-4-specific Nbs using phage display technology. Subsequently, these Nbs were engineered into homodimers to enhance Nb affinity. To prolong in vivo half-life and reduce immunogenicity, we fused an Nb targeting human serum albumin (HSA), resulting in the development of trivalent humanized Nbs. Further, we site-specifically conjugated a monomethyl auristatin E (MMAE) at the C-terminus of the trivalent Nbs, creating Nectin-4 NDC (huNb26/Nb26-Nbh-MMAE) with a drug-to-antibody ratio (DAR) of 1. Nectin-4 NDC demonstrated excellent in vitro cell-binding activities and cytotoxic efficacy against cells with high Nectin-4 expression. Subsequent administration of Nectin-4 NDC to mice bearing NCI-N87 human gastric cancer xenografts demonstrated rapid tissue penetration and high tumor uptake through in vivo imaging. Moreover, Nectin-4 NDC exhibited noteworthy dose-dependent anti-tumor efficacy in in vivo studies. CONCLUSION: We have engineered a Nectin-4 NDC with elevated affinity and effective tumor uptake, further establishing its potential as a therapeutic agent for gastric cancer.


Asunto(s)
Antineoplásicos , Moléculas de Adhesión Celular , Inmunoconjugados , Ratones Desnudos , Anticuerpos de Dominio Único , Neoplasias Gástricas , Neoplasias Gástricas/tratamiento farmacológico , Humanos , Animales , Anticuerpos de Dominio Único/química , Anticuerpos de Dominio Único/farmacología , Moléculas de Adhesión Celular/metabolismo , Línea Celular Tumoral , Ratones , Inmunoconjugados/química , Inmunoconjugados/farmacología , Inmunoconjugados/farmacocinética , Antineoplásicos/farmacología , Antineoplásicos/química , Ratones Endogámicos BALB C , Femenino , Ensayos Antitumor por Modelo de Xenoinjerto , Oligopéptidos/química , Oligopéptidos/farmacología , Nectinas
10.
Mar Drugs ; 22(3)2024 Feb 27.
Artículo en Inglés | MEDLINE | ID: mdl-38535452

RESUMEN

Sea anemone venom, abundant in protein and peptide toxins, serves primarily for predatory defense and competition. This study delves into the insulin-like peptides (ILPs) present in sea anemones, particularly focusing on their role in potentially inducing hypoglycemic shock in prey. We identified five distinct ILPs in Exaiptasia diaphana, exhibiting varied sequences. Among these, ILP-Ap04 was successfully synthesized using solid phase peptide synthesis (SPPS) to evaluate its hypoglycemic activity. When tested in zebrafish, ILP-Ap04 significantly reduced blood glucose levels in a model of diabetes induced by streptozotocin (STZ) and glucose, concurrently affecting the normal locomotor behavior of zebrafish larvae. Furthermore, molecular docking studies revealed ILP-Ap04's unique interaction with the human insulin receptor, characterized by a detailed hydrogen-bonding network, which supports a unique mechanism for its hypoglycemic effects. Our findings suggest that sea anemones have evolved sophisticated strategies to activate insulin receptors in vertebrates, providing innovative insights into the design of novel drugs for the treatment of diabetes.


Asunto(s)
Venenos de Cnidarios , Diabetes Mellitus , Anémonas de Mar , Humanos , Animales , Insulina , Hipoglucemiantes , Pez Cebra , Simulación del Acoplamiento Molecular , Péptidos Similares a la Insulina
11.
Pediatr Radiol ; 54(4): 646-652, 2024 04.
Artículo en Inglés | MEDLINE | ID: mdl-38472490

RESUMEN

Hand-wrist radiography is the most common and accurate method for evaluating children's bone age. To reduce the scattered radiation of radiosensitive organs in bone age assessment, we designed a small X-ray instrument with radioprotection function by adding metal enclosure for X-ray shielding. We used a phantom operator to compare the scattered radiation doses received by sensitive organs under three different protection scenarios (proposed instrument, radiation personal protective equipment, no protection). The proposed instrument showed greater reduction in the mean dose of a single exposure compared with radiation personal protective equipment especially on the left side which was proximal to the X-ray machine (≥80.0% in eye and thyroid, ≥99.9% in breast and gonad). The proposed instrument provides a new pathway towards more convenient and efficient radioprotection.


Asunto(s)
Protección Radiológica , Niño , Humanos , Dosis de Radiación , Rayos X , Radiografía , Protección Radiológica/métodos , Fluoroscopía , Fantasmas de Imagen
12.
J Environ Manage ; 354: 120321, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38377755

RESUMEN

Due to the malodorous effects and health risks of volatile sulfur compounds (VSCs) emitted from wastewater treatment plants (WWTPs), odor collection devices have been extensively utilized; however, their effectiveness has rarely been tested. In the present investigation, the characteristics of VSCs released in a WWTP equipped with gas collection hoods are methodically examined by gas chromatography. The obtained results indicate that the concentration of VSCs in the ambient air can be substantially reduced, and the primary treatment unit still achieves the highest concentration of VSCs. Compared to WWTPs without odor collection devices, the concentration of H2S in this WWTP is not dominant, but its sensory effects and health risks are still not negligible. Additionally, research on the emission of VSCs from sludge reveals that the total VSCs emitted from dewatering sludge reaches the highest level. Volatile organic sulfur compounds play a dominant role in the component and sensory effects of VSCs released by sludge. This study provides both data and theoretical support for analyzing the effectiveness of odor collection devices in WWTPs, as well as reducing the source of VSCs. The findings can be effectively employed to optimize these devices and improve their performance.


Asunto(s)
Compuestos Orgánicos Volátiles , Purificación del Agua , Compuestos de Azufre/análisis , Compuestos de Azufre/química , Aguas del Alcantarillado , Odorantes/análisis , Medición de Riesgo , Compuestos Orgánicos Volátiles/análisis
13.
Molecules ; 29(4)2024 Feb 07.
Artículo en Inglés | MEDLINE | ID: mdl-38398512

RESUMEN

Cardiac hypertrophy (CH) is an important characteristic in heart failure development. Chlorogenic acid (CGA), a crucial bioactive compound from honeysuckle, is reported to protect against CH. However, its underlying mechanism of action remains incompletely elucidated. Therefore, this study aimed to explore the mechanism underlying the protective effect of CGA on CH. This study established a CH model by stimulating AC16 cells with isoproterenol (Iso). The observed significant decrease in cell surface area, evaluated through fluorescence staining, along with the downregulation of CH-related markers, including atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP), and ß-myosin heavy chain (ß-MHC) at both mRNA and protein levels, provide compelling evidence of the protective effect of CGA against isoproterenol-induced CH. Mechanistically, CGA induced the expression of glycogen synthase kinase 3ß (GSK-3ß) while concurrently attenuating the expression of the core protein ß-catenin in the Wnt/ß-catenin signaling pathway. Furthermore, the experiment utilized the Wnt signaling activator IM-12 to observe its ability to modulate the impact of CGA pretreatment on the development of CH. Using the Gene Expression Omnibus (GEO) database combined with online platforms and tools, this study identified Wnt-related genes influenced by CGA in hypertrophic cardiomyopathy (HCM) and further validated the correlation between CGA and the Wnt/ß-catenin signaling pathway in CH. This result provides new insights into the molecular mechanisms underlying the protective effect of CGA against CH, indicating CGA as a promising candidate for the prevention and treatment of heart diseases.


Asunto(s)
Ácido Clorogénico , Vía de Señalización Wnt , Humanos , Isoproterenol/toxicidad , Ácido Clorogénico/farmacología , Glucógeno Sintasa Quinasa 3 beta/metabolismo , Cardiomegalia/inducido químicamente , Cardiomegalia/tratamiento farmacológico , beta Catenina/metabolismo
14.
Angew Chem Int Ed Engl ; 63(3): e202314621, 2024 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-37953402

RESUMEN

Bivalency is a prevalent natural mechanism to enhance receptor avidity. Various two-domain disulfide-rich peptides exhibiting bivalent action have been identified from animal venoms. A unique characteristic of these peptides is that they induce a pharmacological response different from that provoked by any of the constituent domains. The enhanced potency and avidity of such peptides is therefore a consequence of their domain fusion by a peptide linker. The role of the linker itself, beyond conjugation, remains unclear. Here, we investigate how the linker affects the bivalency of the capsaicin receptor (TRPV1) agonist DkTx. We recombinantly produced isotope labelled DkTx using a protein splicing approach, to solve the high-resolution solution structure of DkTx, revealing residual linker order stabilised by linker-domain interactions leading to biased domain orientations. The significance of this was studied using a combination of mutagenesis, spin relaxation studies and electrophysiology measurements. Our results reveal that disrupting the pre-organisation of the domains of DkTx is accompanied by reductions in potency and onset of avidity. Our findings support a model of pre-configured two-domain binding, in favour of the previously suggested sequential binding model. This highlights the significance of ordered elements in linker design and the natural evolution of these in bivalent toxins.


Asunto(s)
Toxinas Biológicas , Animales , Péptidos , Fenómenos Electrofisiológicos
15.
Angew Chem Int Ed Engl ; 63(17): e202400285, 2024 Apr 22.
Artículo en Inglés | MEDLINE | ID: mdl-38441382

RESUMEN

Low Na+ and electron diffusion kinetics severely restrain the rate capability of MoS2 as anode for sodium-ion batteries (SIBs). Slow phase transitions between 2H and 1T, and from NaxMoS2 to Mo and Na2S as well as the volume change during cycling, induce a poor cycling stability. Herein, an original Fe single atom doped MoS2 hollow multishelled structure (HoMS) is designed for the first time to address the above challenges. The Fe single atom in MoS2 promotes the electron transfer, companying with shortened charge diffusion path from unique HoMS, thereby achieving excellent rate capability. The strong adsorption with Na+ and self-catalysis of Fe single atom facilitates the reversible conversion between 2H and 1T, and from NaxMoS2 to Mo and Na2S. Moreover, the buffering effect of HoMS on volume change during cycling improves the cyclic stability. Consequently, the Fe single atom doped MoS2 quadruple-shelled sphere exhibits a high specific capacity of 213.3 mAh g-1 at an ultrahigh current density of 30 A g-1, which is superior to previously-reported results. Even at 5 A g-1, 259.4 mAh g-1 (83.68 %) was reserved after 500 cycles. Such elaborate catalytic site decorated HoMS is also promising to realize other "fast-charging" high-energy-density rechargeable batteries.

16.
EMBO J ; 38(5)2019 03 01.
Artículo en Inglés | MEDLINE | ID: mdl-30723117

RESUMEN

In light of the increasing number of identified cancer-driven gain-of-function (GOF) mutants of p53, it is important to define a common mechanism to systematically target several mutants, rather than developing strategies tailored to inhibit each mutant individually. Here, using RNA immunoprecipitation-sequencing (RIP-seq), we identified the Polycomb-group histone methyltransferase EZH2 as a p53 mRNA-binding protein. EZH2 bound to an internal ribosome entry site (IRES) in the 5'UTR of p53 mRNA and enhanced p53 protein translation in a methyltransferase-independent manner. EZH2 augmented p53 GOF mutant-mediated cancer growth and metastasis by increasing protein levels of mutant p53. EZH2 overexpression was associated with worsened outcome selectively in patients with p53-mutated cancer. Depletion of EZH2 by antisense oligonucleotides inhibited p53 GOF mutant-mediated cancer growth. Our findings reveal a non-methyltransferase function of EZH2 that controls protein translation of p53 GOF mutants, inhibition of which causes synthetic lethality in cancer cells expressing p53 GOF mutants.


Asunto(s)
Proteína Potenciadora del Homólogo Zeste 2/metabolismo , Mutación con Ganancia de Función , Regulación Neoplásica de la Expresión Génica , Neoplasias de la Próstata/patología , ARN Mensajero/metabolismo , Proteína p53 Supresora de Tumor/metabolismo , Animales , Apoptosis , Proliferación Celular , Proteína Potenciadora del Homólogo Zeste 2/genética , Humanos , Sitios Internos de Entrada al Ribosoma , Masculino , Ratones , Ratones Endogámicos NOD , Ratones SCID , Metástasis de la Neoplasia , Neoplasias de la Próstata/genética , Neoplasias de la Próstata/metabolismo , Estabilidad Proteica , ARN Mensajero/genética , Células Tumorales Cultivadas , Proteína p53 Supresora de Tumor/química , Proteína p53 Supresora de Tumor/genética , Ensayos Antitumor por Modelo de Xenoinjerto
17.
Cardiovasc Diabetol ; 22(1): 183, 2023 07 20.
Artículo en Inglés | MEDLINE | ID: mdl-37474925

RESUMEN

BACKGROUND: To investigate the association of variability in metabolic parameters such as total cholesterol concentrations (TC), uric acid (UA), body mass index (BMI), visceral adiposity index (VAI) and systolic blood pressure (SBP) with incident type 2 diabetes (T2D) and whether variability in these metabolic parameters has additive effects on the risk of T2D. METHODS: Based on the Beijing Functional Community Cohort, 4392 participants who underwent three health examinations (2015, 2016, and 2017) were followed up for incident T2D until the end of 2021. Variability in metabolic parameters from three health examinations were assessed using the coefficient of variation, standard deviation, variability independent of the mean, and average real variability. High variability was defined as the highest quartile of variability index. Participants were grouped according to the number of high-variability metabolic parameters. Cox proportional hazards models were performed to assess the hazard ratio (HR) and 95% confidence interval (CI) for incident T2D. RESULTS: During a median follow-up of 3.91 years, 249 cases of incident T2D were identified. High variability in TC, BMI, VAI and SBP was significantly associated with higher risks of incident T2D. As for UA, significant multiplicative interaction was found between variability in UA and variability in other four metabolic parameters for incident T2D. The risk of T2D significantly increased with the increasing numbers of high-variability metabolic parameters. Compared with the group with low variability for 5 parameters, the HR (95% CI) for participants with 1-2, 3, 4-5 high-variability metabolic parameters were 1.488 (1.051, 2.107), 2.036 (1.286, 3.222) and 3.017 (1.549, 5.877), respectively. Similar results were obtained in various sensitivity analyses. CONCLUSIONS: High variability of TC, BMI, VAI and SBP were independent predictors of incident T2D, respectively. There was a graded association between the number of high-variability metabolic parameters and incident T2D.


Asunto(s)
Diabetes Mellitus Tipo 2 , Humanos , Diabetes Mellitus Tipo 2/diagnóstico , Diabetes Mellitus Tipo 2/epidemiología , Factores de Riesgo , Incidencia , Obesidad Abdominal/complicaciones , Índice de Masa Corporal
18.
Environ Sci Technol ; 57(2): 1157-1166, 2023 01 17.
Artículo en Inglés | MEDLINE | ID: mdl-36602942

RESUMEN

Harmful algae blooms (HABs) frequently occur all over the world and cause great harm to the environment, human health, and aquatic ecosystems. However, owing to their great growth rate and large nutrient intake capacity, algae can enrich a large amount of carbon (CO2) and nutritional elements (N and P) in their biomass. Thus, this could be applied as a robust approach to battle global warming and water eutrophication if the harmful algae biomass was effectively harvested and utilized. Herein, we propose a thermochemical approach to convert algae biomass into a nitrogen-doped electrocatalyst for CO2 reduction. The as-synthesized carbon catalyst exhibits a favorable electrochemical CO2 reduction activity. The key drivers of the environmental impacts in the thermochemical conversion approach with a comparison with the commonly used landfilling approach are identified with life cycle assessment. The former presents much lower environmental burdens in terms of impacts such as freshwater/terrestrial ecotoxicity and human toxicity than the latter. Moreover, if the thermochemical conversion process was successfully applied for biomass conversion worldwide, 2.17 × 108 tons of CO2-eq, 8.42 × 106 tons of N, and 1.21 × 106 tons of P could be removed from the global carbon and other element cycles. Meanwhile, the thermochemical approach is also similar to landfilling in terms of costs. The results from this work provide a brand-new perspective for achieving twofold CO2 utilization and efficiently battling harmful algae blooms.


Asunto(s)
Dióxido de Carbono , Ecosistema , Humanos , Biomasa , Floraciones de Algas Nocivas , Carbono
19.
BMC Pregnancy Childbirth ; 23(1): 193, 2023 Mar 18.
Artículo en Inglés | MEDLINE | ID: mdl-36934233

RESUMEN

BACKGROUND: The current detection of fetal chromosomal abnormalities by non-invasive prenatal testing (NIPT) mainly relies on the cell free DNA(cfDNA) in the maternal blood. However, a gestational age of less than 12 weeks or a high maternal BMI affects cfDNA fetal fraction and further the detection by NIPT negatively. In this study, we aim to retrieve the trophoblast cells from the maternal cervix to develop a new sampling method for NIPT enabling an earlier use of NIPT. METHODS: We enrolled three patients who wanted to undergo induced abortion at Beijing Hospital between January 2022 and March 2022. Peripheral blood, cervix specimen, and the abortion tissue were collected and processed for each patient. Allele frequencies of the mutated gene loci of the maternal blood and the cervix sample were compared and the Sex Determining Region Y (SRY) gene was tested. RESULTS: The allele frequencies of the mutated gene loci showed no significant difference between the maternal blood and the cervix sample. But we successfully detected signal of the SRY gene in the cervix sample of the only patient carrying a male fetus. CONCLUSIONS: The detection of the SRY gene in a cervix sample indicated a successful retrieval of trophoblast cells from the cervix canal. Further study needs to be conducted to verify our finding before its application to the clinical settings.


Asunto(s)
Ácidos Nucleicos Libres de Células , Diagnóstico Prenatal , Embarazo , Femenino , Humanos , Masculino , Lactante , Diagnóstico Prenatal/métodos , Trofoblastos , Proyectos Piloto , Cuello del Útero
20.
Acta Neurochir (Wien) ; 165(3): 613-623, 2023 03.
Artículo en Inglés | MEDLINE | ID: mdl-36595057

RESUMEN

BACKGROUND: Superficial temporal artery-middle cerebral artery (STA-MCA) bypass is a common surgery in treating moyamoya disease (MMD) with occluded MCA. Computational fluid dynamics (CFD) simulation might provide a simple, non-invasive, and low-cost tool to evaluate the efficacy of STA-MCA surgery. AIM: We aim to quantitatively investigate the treatment efficacy of STA-MCA surgery in improving the blood flow of MMD patients using CFD simulation. METHODS: This retrospective study included 11 MMD patients with occlusion around proximal MCA who underwent STA-MCA bypass surgery. CFD simulation was performed using patient-specific blood pressure and postoperative artery geometry. The volumetric flow rates of STA and the bypass, average flow velocity in the proximal segment of transcranial bypass, transcranial pressure drop, and transcranial flow resistance were measured and compared with a postoperative increment of cerebral blood flow (CBF) in MCA territories derived from perfusion imaging. Per-branch pressure drop from model inlet to bypass branch outlet was calculated. RESULTS: The volumetric flow rates of STA and the bypass were 80.84 ± 14.54 mL/min and 46.03 ± 4.21 mL/min. Average flow velocity in proximal bypass, transcranial pressure drop, and transcranial flow resistance were 0.19 ± 0.07 m/s, 3.72 ± 3.10 mmHg, and 6.54 ± 5.65 10-8 Pa s m-3. Postoperative mean increment of CBF in MCA territories was 16.03 ± 11.72 mL·100 g-1·min-1. Per-branch pressure drop was 10.96 ± 5.59 mmHg and 7.26 ± 4.25 mmHg in branches with and without stenosis. CONCLUSIONS: CFD simulation results are consistent with CBF observation in verifying the efficacy of STA-MCA bypass, where postoperative stenosis may influence the hemodynamics.


Asunto(s)
Revascularización Cerebral , Enfermedad de Moyamoya , Humanos , Enfermedad de Moyamoya/cirugía , Proyectos Piloto , Arteria Cerebral Media/cirugía , Arterias Temporales/cirugía , Estudios Retrospectivos , Constricción Patológica , Revascularización Cerebral/métodos , Hemodinámica , Circulación Cerebrovascular , Simulación por Computador , Imagen de Perfusión
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA