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1.
Nature ; 622(7981): 195-201, 2023 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-37730991

RESUMEN

Type A γ-aminobutyric acid receptors (GABAARs) are the principal inhibitory receptors in the brain and the target of a wide range of clinical agents, including anaesthetics, sedatives, hypnotics and antidepressants1-3. However, our understanding of GABAAR pharmacology has been hindered by the vast number of pentameric assemblies that can be derived from 19 different subunits4 and the lack of structural knowledge of clinically relevant receptors. Here, we isolate native murine GABAAR assemblies containing the widely expressed α1 subunit and elucidate their structures in complex with drugs used to treat insomnia (zolpidem (ZOL) and flurazepam) and postpartum depression (the neurosteroid allopregnanolone (APG)). Using cryo-electron microscopy (cryo-EM) analysis and single-molecule photobleaching experiments, we uncover three major structural populations in the brain: the canonical α1ß2γ2 receptor containing two α1 subunits, and two assemblies containing one α1 and either an α2 or α3 subunit, in which the single α1-containing receptors feature a more compact arrangement between the transmembrane and extracellular domains. Interestingly, APG is bound at the transmembrane α/ß subunit interface, even when not added to the sample, revealing an important role for endogenous neurosteroids in modulating native GABAARs. Together with structurally engaged lipids, neurosteroids produce global conformational changes throughout the receptor that modify the ion channel pore and the binding sites for GABA and insomnia medications. Our data reveal the major α1-containing GABAAR assemblies, bound with endogenous neurosteroid, thus defining a structural landscape from which subtype-specific drugs can be developed.


Asunto(s)
Microscopía por Crioelectrón , Neuroesteroides , Receptores de GABA-A , Ácido gamma-Aminobutírico , Animales , Ratones , Sitios de Unión/efectos de los fármacos , Depresión Posparto/tratamiento farmacológico , Flurazepam/farmacología , Ácido gamma-Aminobutírico/metabolismo , Hipnóticos y Sedantes/farmacología , Activación del Canal Iónico/efectos de los fármacos , Neuroesteroides/metabolismo , Neuroesteroides/farmacología , Fotoblanqueo , Pregnanolona/farmacología , Conformación Proteica/efectos de los fármacos , Subunidades de Proteína/química , Subunidades de Proteína/efectos de los fármacos , Subunidades de Proteína/metabolismo , Receptores de GABA-A/química , Receptores de GABA-A/efectos de los fármacos , Receptores de GABA-A/metabolismo , Receptores de GABA-A/ultraestructura , Trastornos del Inicio y del Mantenimiento del Sueño/tratamiento farmacológico , Zolpidem/farmacología
2.
Proc Natl Acad Sci U S A ; 119(45): e2210618119, 2022 Nov 08.
Artículo en Inglés | MEDLINE | ID: mdl-36322759

RESUMEN

Alterations of the tumor suppressor TP53, one of the most common events in cancer, alone are insufficient for tumor development but serve as drivers of transformation. We sought to identify cooperating events through genomic analyses of a somatic Trp53R245W mouse model (equivalent to the TP53R248W hot spot mutation in human cancers) that recapitulates metastatic breast-cancer development. We identified cooperating lesions similar to those found in human breast cancers. Moreover, we identified activation of the Pi3k/Akt/mTOR pathway in most tumors via mutations in Pten, Erbb2, Kras, and/or a recurrent Pip5k1c mutation that stabilizes the Pip5k1c protein and activates Pi3k/Akt/mTOR signaling. Another PIP5K1C family member, PIP5K1A, is coamplified with PI4KB in 18% of human breast cancer patients; both encode kinases that are responsible for production of the PI3K substrate, phosphatidylinositol 4,5-bisphosphate. Thus, the TP53R248W mutation and PI3K/AKT/mTOR signaling are major cooperative events driving breast-cancer development. Additionally, a combination of two US Food and Drug Administration (FDA)-approved drugs, tigecycline and metformin, which target oxidative phosphorylation downstream of PI3K signaling, inhibited tumor cell growth and may be repurposed for breast-cancer treatment. These findings advance our understanding of how mutant p53 drives breast-tumor development and pinpoint the importance of PI3K/AKT/mTOR signaling, expanding combination therapies for breast-cancer treatment.


Asunto(s)
Neoplasias de la Mama , Fosfatidilinositol 3-Quinasas , Animales , Femenino , Humanos , Ratones , Neoplasias de la Mama/patología , Fosfatidilinositol 3-Quinasas/genética , Fosfatidilinositol 3-Quinasas/metabolismo , Proteínas Proto-Oncogénicas c-akt/genética , Proteínas Proto-Oncogénicas c-akt/metabolismo , Transducción de Señal/genética , Serina-Treonina Quinasas TOR/genética , Serina-Treonina Quinasas TOR/metabolismo , Proteína p53 Supresora de Tumor/metabolismo
3.
Gut ; 73(7): 1142-1155, 2024 Jun 06.
Artículo en Inglés | MEDLINE | ID: mdl-38553043

RESUMEN

OBJECTIVE: Currently, there is no cure for chronic pancreatitis (CP). Germline loss-of-function variants in SPINK1 (encoding trypsin inhibitor) are common in patients with CP and are associated with acute attacks and progression of the disease. This preclinical study was conducted to explore the potential of adeno-associated virus type 8 (AAV8)-mediated overexpression of human SPINK1 (hSPINK1) for pancreatitis therapy in mice. DESIGN: A capsid-optimised AAV8-mediated hSPINK1 expression vector (AAV8-hSPINK1) to target the pancreas was constructed. Mice were treated with AAV8-hSPINK1 by intraperitoneal injection. Pancreatic transduction efficiency and safety of AAV8-hSPINK1 were dynamically evaluated in infected mice. The effectiveness of AAV8-hSPINK1 on pancreatitis prevention and treatment was studied in three mouse models (caerulein-induced pancreatitis, pancreatic duct ligation and Spink1 c.194+2T>C mouse models). RESULTS: The constructed AAV8-hSPINK1 vector specifically and safely targeted the pancreas, had low organ tropism for the heart, lungs, spleen, liver and kidneys and had a high transduction efficiency (the optimal expression dose was 2×1011 vg/animal). The expression and efficacy of hSPINK1 peaked at 4 weeks after injection and remained at significant level for up to at least 8 weeks. In all three mouse models, a single dose of AAV8-hSPINK1 before disease onset significantly alleviated the severity of pancreatitis, reduced the progression of fibrosis, decreased the levels of apoptosis and autophagy in the pancreas and accelerated the pancreatitis recovery process. CONCLUSION: One-time injection of AAV8-hSPINK1 safely targets the pancreas with high transduction efficiency and effectively ameliorates pancreatitis phenotypes in mice. This approach is promising for the prevention and treatment of CP.


Asunto(s)
Dependovirus , Modelos Animales de Enfermedad , Terapia Genética , Vectores Genéticos , Animales , Ratones , Terapia Genética/métodos , Dependovirus/genética , Inhibidor de Tripsina Pancreática de Kazal/genética , Páncreas/patología , Páncreas/metabolismo , Humanos , Pancreatitis Crónica/genética , Pancreatitis Crónica/terapia , Masculino , Pancreatitis/terapia , Pancreatitis/prevención & control , Pancreatitis/genética
4.
Ann Hum Genet ; 88(2): 126-137, 2024 03.
Artículo en Inglés | MEDLINE | ID: mdl-37846608

RESUMEN

INTRODUCTION: Prostate cancer is one of the most common cancer types in males and rs12621278:A > G has been suggested to be associated with this disease by previous genome-wide association studies. One thousand genomes project data analysis indicated that rs12621278:A > G is within two long-core haplotypes. However, the origin, causal variant(s), and molecular function of these haplotypes were remaining unclear. MATERIALS AND METHODS: Population genetics analysis and functional genomics work was performed for this locus. RESULTS: Phylogeny analysis verified that the rare haplotype is derived from Neanderthal introgression. Genome annotation suggested that three genetic variants in the core haplotypes, rs116108611:G > A, rs139972066:AAAAAAAA > AAAAAAAAA, and rs3835124:ATTTATT > ATT, are located in functional regions. Luciferase assay indicated that rs139972066:AAAAAAAA > AAAAAAAAA and rs116108611:G > A are not able to alter ITGA6 (integrin alpha 6) and ITGA6 antisense RNA 1 expression, respectively. In contrast, rs3835124:ATTTATT > ATT can significantly influence PDK1 (pyruvate dehydrogenase kinase 1) expression, which was verified by expression quantitative trait locus analysis. This genetic variant can alter transcription factor cut like homeobox 1 interaction efficiency. The introgressed haplotype was observed to be subject to positive selection in East Asian populations. The molecular function of the haplotype suggested that Neanderthal should be with lower PDK1 expression and further different energy homeostasis from modern human. CONCLUSION: This study provided new insight into the contribution of Neanderthal introgression to human phenotypes.


Asunto(s)
Hombre de Neandertal , Neoplasias , Humanos , Animales , Hombre de Neandertal/genética , Estudio de Asociación del Genoma Completo , Genética de Población , Filogenia , Haplotipos , Genoma Humano , Neoplasias/genética
5.
Small ; 20(12): e2307052, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-37946708

RESUMEN

Design of highly efficient electrocatalysts for alkaline hydrogen evolution reaction (HER) is of paramount importance for water electrolysis, but still a considerable challenge because of the slow HER kinetics in alkaline environments. Alloying is recognized as an effective strategy to enhance the catalytic properties. Lanthanides (Ln) are recognized as an electronic and structural regulator, attributed to their unique 4f electron behavior and the phenomenon known as lanthanide contraction. Here, a new class of Rh3Ln intermetallics (IMs) are synthesized using the sodium vapor reduction method. The alloying process induced an upshift of the d-band center and electron transfer from Ln to Rh, resulting in optimized adsorption and dissociation energies for H2O molecules. Consequently, Rh3Tb IMs exhibited outstanding HER activity in both alkaline environments and seawater, displaying an overpotential of only 19 mV at 10 mA cm-2 and a Tafel slope of 22.2 mV dec-1. Remarkably, the current density of Rh3Tb IMs at 100 mV overpotential is 8.6 and 5.7 times higher than that of Rh/C and commercial Pt/C, respectively. This work introduces a novel approach to the rational design of HER electrocatalysis and sheds light on the role of lanthanides in electrocatalyst systems.

6.
Small ; : e2400662, 2024 Mar 27.
Artículo en Inglés | MEDLINE | ID: mdl-38534137

RESUMEN

Developing high-performance electrocatalysts for alkaline hydrogen evolution reaction (HER) is crucial for producing green hydrogen, yet it remains challenging due to the sluggish kinetics in alkaline environments. Pt is located near the peak of HER volcano plot, owing to its exceptional performance in hydrogen adsorption and desorption, and Rh plays an important role in H2O dissociation. Lanthanides (Ln) are commonly used to modulate the electronic structure of materials and further influence the adsorption/desorption of reactants, intermediates, and products, and noble metal-Ln alloys are recognized as effective platforms where Ln elements regulate the catalytic properties of noble metals. Here Pt1.5Rh1.5Tm alloy is synthesized using the sodium vapor reduction method. This alloy demonstrates superior catalytic activity, being 4.4 and 6.6 times more effective than Pt/C and Rh/C, respectively. Density Functional Theory (DFT) calculations reveal that the upshift of d-band center and the charge transfer induced by alloying promote adsorption and dissociation of H2O, making Pt1.5Rh1.5Tm alloy more favorable for the alkaline HER reaction, both kinetically and thermodynamically.

7.
Small ; : e2400149, 2024 Mar 25.
Artículo en Inglés | MEDLINE | ID: mdl-38528389

RESUMEN

Layered Na2FePO4F (NFPF) cathode material has received widespread attention due to its green nontoxicity, abundant raw materials, and low cost. However, its poor inherent electronic conductivity and sluggish sodium ion transportation seriously impede its capacity delivery and cycling stability. In this work, NFPF by Ti doping and conformal carbon layer coating via solid-state reaction is modified. The results of experimental study and density functional theory calculations reveal that Ti doping enhances intrinsic conductivity, accelerates Na-ion transport, and generates more Na-ion storage sites, and pyrolytic carbon from polyvinylpyrrolidone (PVP) uniformly coated on the NFPF surface improves the surface/interface conductivity and suppresses the side reactions. Under the combined effect of Ti doping and carbon coating, the optimized NFPF (marked as 5T-NF@C) exhibits excellent electrochemical performance, with a high capacity of 108.4 mAh g-1 at 0.2C, a considerable capacity of 80.0 mAh g-1 even at high current density of 10C, and a high capacity retention rate of 81.8% after 2000 cycles at 10C. When assembled into a full cell with a hard carbon anode, 5T-NF@C also show good applicability. This work indicates that co-modification of Ti doping and carbon coating makes NFPF achieve high rate and long cycle performance for sodium-ion batteries.

8.
Brief Bioinform ; 23(2)2022 03 10.
Artículo en Inglés | MEDLINE | ID: mdl-35108362

RESUMEN

MOTIVATION: Effective computational methods to predict drug-protein interactions (DPIs) are vital for drug discovery in reducing the time and cost of drug development. Recent DPI prediction methods mainly exploit graph data composed of multiple kinds of connections among drugs and proteins. Each node in the graph usually has topological structures with multiple scales formed by its first-order neighbors and multi-order neighbors. However, most of the previous methods do not consider the topological structures of multi-order neighbors. In addition, deep integration of the multi-modality similarities of drugs and proteins is also a challenging task. RESULTS: We propose a model called ALDPI to adaptively learn the multi-scale topologies and multi-modality similarities with various significance levels. We first construct a drug-protein heterogeneous graph, which is composed of the interactions and the similarities with multiple modalities among drugs and proteins. An adaptive graph learning module is then designed to learn important kinds of connections in heterogeneous graph and generate new topology graphs. A module based on graph convolutional autoencoders is established to learn multiple representations, which imply the node attributes and multiple-scale topologies composed of one-order and multi-order neighbors, respectively. We also design an attention mechanism at neighbor topology level to distinguish the importance of these representations. Finally, since each similarity modality has its specific features, we construct a multi-layer convolutional neural network-based module to learn and fuse multi-modality features to obtain the attribute representation of each drug-protein node pair. Comprehensive experimental results show ALDPI's superior performance over six state-of-the-art methods. The results of recall rates of top-ranked candidates and case studies on five drugs further demonstrate the ability of ALDPI to discover potential drug-related protein candidates. CONTACT: zhang@hlju.edu.cn.


Asunto(s)
Algoritmos , Redes Neurales de la Computación , Desarrollo de Medicamentos/métodos , Interacciones Farmacológicas , Proteínas
9.
Phys Rev Lett ; 132(13): 133603, 2024 Mar 29.
Artículo en Inglés | MEDLINE | ID: mdl-38613308

RESUMEN

An integrated quantum light source is increasingly desirable in large-scale quantum information processing. Despite recent remarkable advances, a new material platform is constantly being explored for the fully on-chip integration of quantum light generation, active and passive manipulation, and detection. Here, for the first time, we demonstrate a gallium nitride (GaN) microring based quantum light generation in the telecom C-band, which has potential toward the monolithic integration of quantum light source. In our demonstration, the GaN microring has a free spectral range of 330 GHz and a near-zero anomalous dispersion region of over 100 nm. The generation of energy-time entangled photon pair is demonstrated with a typical raw two-photon interference visibility of 95.5±6.5%, which is further configured to generate a heralded single photon with a typical heralded second-order autocorrelation g_{H}^{(2)}(0) of 0.045±0.001. Our results pave the way for developing a chip-scale quantum photonic circuit.

10.
Pancreatology ; 24(5): 677-689, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-38763786

RESUMEN

BACKGROUND & AIMS: Mutations in genes, including serine protease inhibitor Kazal-type 1 (SPINK1), influence disease progression following sentinel acute pancreatitis event (SAPE) attacks. SPINK1 c.194+2T > C intron mutation is one of the main mutants of SPINK1,which leads to the impairment of SPINK1 function by causing skipping of exon 3. Research on the pathogenesis of SAPE attacks would contribute to the understanding of the outcomes of acute pancreatitis. Therefore, the aim of the study was to clarify the role of SPINK1 c.194+2T > C mutation in the CP progression after an AP attack. METHODS: SAPE attacks were induced in wildtype and SPINK mutant (Spink1 c.194+2T > C) mice by cerulein injection. The mice were sacrificed at 24 h, 14 d, 28 d, and 42 d post-SAPE. Data-independent acquisition (DIA) proteomic analysis was performed for the identification of differentially expressed protein in the pancreatic tissues. Functional analyses were performed using THP-1 and HPSCs. RESULTS: Following SAPE attack, the Spink1 c.194+2T > C mutant mice exhibited a more severe acute pancreatitis phenotype within 24 h. In the chronic phase, the chronic pancreatitis phenotype was more severe in the Spink1 c.194+2T > C mutant mice after SAPE. Proteomic analysis revealed elevated IL-33 level in Spink1 c.194+2T > C mutant mice. Further in vitro analyses revealed that IL-33 induced M2 polarization of macrophages and activation of pancreatic stellate cells. CONCLUSION: Spink1 c.194+2T > C mutation plays an important role in the prognosis of patients following SAPE. Heterozygous Spink1 c.194+2T > C mutation promotes the development of chronic pancreatitis after an acute attack in mice through elevated IL-33 level and the induction of M2 polarization in coordination with pancreatic stellate cell activation.


Asunto(s)
Mutación , Pancreatitis Crónica , Inhibidor de Tripsina Pancreática de Kazal , Animales , Inhibidor de Tripsina Pancreática de Kazal/genética , Ratones , Pancreatitis Crónica/genética , Pancreatitis Crónica/patología , Masculino , Ratones Endogámicos C57BL , Heterocigoto , Humanos , Enfermedad Aguda , Progresión de la Enfermedad , Glicoproteínas , Proteínas de Secreción Prostática
11.
Inorg Chem ; 63(4): 2060-2071, 2024 Jan 29.
Artículo en Inglés | MEDLINE | ID: mdl-38232754

RESUMEN

The synthesis of two versatile fluorescent metal-organic frameworks (MOFs), [Eu(4-NCP)(1,4-bdc)]n·0.5H2O (1) and [Eu(4-NCP)(4,4'-bpdc)]n·0.75H2O (2) (HNCP = 2-(4-carboxyphenyl)imidazo(4,5-f)-(1,10)phenanthroline, 1,4-H2bdc = benzene-1,4-dicarboxylic acid, 4,4'-H2bpdc = 4,4'-biphenyldicarboxylic acid), was carried out using a hydrothermal method. These MOFs were characterized through various advanced technologies to determine their structural information. The results indicate that both MOFs exhibited 3D network structures with specific topologies. Furthermore, these MOFs demonstrated exceptional thermal stabilities and adsorption capabilities. Additionally, complex 2 was utilized for studying the fluorescence sensing properties of various micronutrients including metal ions, nitro aromatic compounds, and biological small molecules. Notably, complex 2 showed promising potential as a multifunctional sensor for selectively detecting Fe3+, nitrobenzene, and ascorbic acid in aqueous solutions through fluorescence quenching with low limits of detection (LODs ∼ 10-7 M) and high quenching constants (Ksv ∼ 103 M-1). Moreover, the detection mechanism of complex 2 was further investigated by using experimental methods and DFT calculations.

12.
BMC Infect Dis ; 24(1): 426, 2024 Apr 22.
Artículo en Inglés | MEDLINE | ID: mdl-38649799

RESUMEN

BACKGROUND: Severe acute respiratory infection (SARI), a significant global health concern, imposes a substantial disease burden. In China, there is inadequate data concerning the monitoring of respiratory pathogens, particularly bacteria, among patients with SARI. Therefore, this study aims to delineate the demographic, epidemiological, and aetiological characteristics of hospitalised SARI patients in Central China between 2018 and 2020. METHODS: Eligible patients with SARI admitted to the First Affiliated Hospital of Zhengzhou University between 1 January 2018 and 31 December 2020 were included in this retrospective study. Within the first 24 h of admission, respiratory (including sputum, nasal/throat swabs, bronchoalveolar lavage fluid, thoracocentesis fluid, etc.), urine, and peripheral blood specimens were collected for viral and bacterial testing. A multiplex real-time polymerase chain reaction (PCR) diagnostic approach was used to identify human influenza virus, respiratory syncytial virus, parainfluenza virus, adenovirus, human bocavirus, human coronavirus, human metapneumovirus, and rhinovirus. Bacterial cultures of respiratory specimens were performed with a particular focus on pathogenic microorganisms, including S. pneumoniae, S. aureus, K. pneumoniae, P. aeruginosa, Strep A, H. influenzae, A. baumannii, and E. coli. In cases where bacterial culture results were negative, nucleic acid extraction was performed for PCR to assay for the above-mentioned eight bacteria, as well as L. pneumophila and M. pneumoniae. Additionally, urine specimens were exclusively used to detect Legionella antigens. Furthermore, epidemiological, demographic, and clinical data were obtained from electronic medical records. RESULTS: The study encompassed 1266 patients, with a mean age of 54 years, among whom 61.6% (780/1266) were males, 61.4% (778/1266) were farmers, and 88.8% (1124/1266) sought medical treatment in 2020. Moreover, 80.3% (1017/1266) were housed in general wards. The most common respiratory symptoms included fever (86.8%, 1122/1266) and cough (77.8%, 986/1266). Chest imaging anomalies were detected in 62.6% (792/1266) of cases, and 58.1% (736/1266) exhibited at least one respiratory pathogen, with 28.5% (361/1266) having multiple infections. Additionally, 95.7% (1212/1266) of the patients were from Henan Province, with the highest proportion (38.3%, 486/1266) falling in the 61-80 years age bracket, predominantly (79.8%, 1010/1266) seeking medical aid in summer and autumn. Bacterial detection rate (39.0%, 495/1266) was higher than viral detection rate (36.9%, 468/1266), with the primary pathogens being influenza virus (13.8%, 175/1266), K. pneumoniae (10.0%, 127/1266), S. pneumoniae (10.0%, 127/1266), adenovirus (8.2%, 105/1266), P. aeruginosa (8.2%, 105/1266), M. pneumoniae (7.8%, 100/1266), and respiratory syncytial virus (7.7%, 98/1266). During spring and winter, there was a significant prevalence of influenza virus and human coronavirus, contrasting with the dominance of parainfluenza viruses in summer and autumn. Respiratory syncytial virus and rhinovirus exhibited higher prevalence across spring, summer, and winter. P. aeruginosa, K. pneumoniae, and M. pneumoniae were identified at similar rates throughout all seasons without distinct spikes in prevalence. However, S. pneumoniae showed a distinctive pattern with a prevalence that doubled during summer and winter. Moreover, the positive detection rates of various other viruses and bacteria were lower, displaying a comparatively erratic prevalence trend. Among patients admitted to the intensive care unit, the predominant nosocomial bacteria were K. pneumoniae (17.2%, 43/249), A. baumannii (13.6%, 34/249), and P. aeruginosa (12.4%, 31/249). Conversely, in patients from general wards, predominant pathogens included influenza virus (14.8%, 151/1017), S. pneumoniae (10.4%, 106/1017), and adenovirus (9.3%, 95/1017). Additionally, paediatric patients exhibited significantly higher positive detection rates for influenza virus (23.9%, 11/46) and M. pneumoniae (32.6%, 15/46) compared to adults and the elderly. Furthermore, adenovirus (10.0%, 67/669) and rhinovirus (6.4%, 43/669) were the primary pathogens in adults, while K. pneumoniae (11.8%, 65/551) and A. baumannii (7.1%, 39/551) prevailed among the elderly, indicating significant differences among the three age groups. DISCUSSION: In Central China, among patients with SARI, the prevailing viruses included influenza virus, adenovirus, and respiratory syncytial virus. Among bacteria, K. pneumoniae, S. pneumoniae, P. aeruginosa, and M. pneumoniae were frequently identified, with multiple infections being very common. Additionally, there were substantial variations in the pathogen spectrum compositions concerning wards and age groups among patients. Consequently, this study holds promise in offering insights to the government for developing strategies aimed at preventing and managing respiratory infectious diseases effectively.


Asunto(s)
Infecciones del Sistema Respiratorio , Humanos , China/epidemiología , Estudios Retrospectivos , Infecciones del Sistema Respiratorio/epidemiología , Infecciones del Sistema Respiratorio/virología , Infecciones del Sistema Respiratorio/microbiología , Masculino , Femenino , Persona de Mediana Edad , Adulto , Anciano , Adolescente , Adulto Joven , Niño , Preescolar , Enfermedad Aguda , Lactante , Anciano de 80 o más Años , Virus/aislamiento & purificación , Virus/clasificación , Virus/genética , Hospitalización/estadística & datos numéricos
13.
Nature ; 557(7703): 123-126, 2018 05.
Artículo en Inglés | MEDLINE | ID: mdl-29695868

RESUMEN

Alternative complex III (ACIII) is a key component of the respiratory and/or photosynthetic electron transport chains of many bacteria1-3. Like complex III (also known as the bc1 complex), ACIII catalyses the oxidation of membrane-bound quinol and the reduction of cytochrome c or an equivalent electron carrier. However, the two complexes have no structural similarity4-7. Although ACIII has eluded structural characterization, several of its subunits are known to be homologous to members of the complex iron-sulfur molybdoenzyme (CISM) superfamily 8 , including the proton pump polysulfide reductase9,10. We isolated the ACIII from Flavobacterium johnsoniae with native lipids using styrene maleic acid copolymer11-14, both as an independent enzyme and as a functional 1:1 supercomplex with an aa3-type cytochrome c oxidase (cyt aa3). We determined the structure of ACIII to 3.4 Å resolution by cryo-electron microscopy and constructed an atomic model for its six subunits. The structure, which contains a [3Fe-4S] cluster, a [4Fe-4S] cluster and six haem c units, shows that ACIII uses known elements from other electron transport complexes arranged in a previously unknown manner. Modelling of the cyt aa3 component of the supercomplex revealed that it is structurally modified to facilitate association with ACIII, illustrating the importance of the supercomplex in this electron transport chain. The structure also resolves two of the subunits of ACIII that are anchored to the lipid bilayer with N-terminal triacylated cysteine residues, an important post-translational modification found in numerous prokaryotic membrane proteins that has not previously been observed structurally in a lipid bilayer.


Asunto(s)
Microscopía por Crioelectrón , Grupo Citocromo c/química , Grupo Citocromo c/ultraestructura , Citocromos a3/química , Citocromos a3/ultraestructura , Citocromos a/química , Citocromos a/ultraestructura , Complejo III de Transporte de Electrones/química , Complejo III de Transporte de Electrones/ultraestructura , Flavobacterium/enzimología , Cisteína/química , Cisteína/metabolismo , Grupo Citocromo c/metabolismo , Citocromos a/metabolismo , Citocromos a3/metabolismo , Complejo III de Transporte de Electrones/metabolismo , Hemo/análogos & derivados , Hemo/química , Membrana Dobles de Lípidos/química , Membrana Dobles de Lípidos/metabolismo , Lípidos/química , Modelos Moleculares , Nanoestructuras/química , Nanoestructuras/ultraestructura , Oxidación-Reducción , Subunidades de Proteína/química , Subunidades de Proteína/metabolismo
14.
Clin Exp Pharmacol Physiol ; 51(6): e13859, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38643975

RESUMEN

Previous study has demonstrated that the Dietary Inflammation Index (DII) played a role in the risk of inflammatory bowel disease (IBD), however, the prevalence and risk factors for IBD are distinct across locations and groups, and therefore, the findings are debatable and warrant further investigation. A total of 4363 participants were calculated in the National Health and Nutrition Examination Survey (NHANES) 2009 to 2010, of whom 1.21% self-reported a history of IBD. DII values were performed as a good predictor of dietary inflammation based on data from two 24-h dietary reviews in the NHANES database. Comparing the multifarious effects along with variations of the whole population by grouping populations according to DII quartiles, dietary inflammation levels increased progressively from DII quartile 1(Q1) to quartile 4(Q4). The association between DII and IBD was tested with multi-variable logistic regression models, subgroup analyses and weighted generalized additive models. Participants in the Q4 group showed the highest levels of C-reactive protein and reduced haemoglobin and albumin levels. Logistic regression confirmed the odds ratios (95% confidence intervals) of IBD for DII were 0.99 (0.86, 1.15), 0.97 (0.84, 1.13) and 0.80 (0.66, 0.98) in models 1, 2 and 3, respectively. The negative correlation between DII and IBD among United States adults from the NHANES database became increasingly apparent as covariates were adjusted. Subgroup analyses and smoothed curve fitting confirmed the inverse results. The study revealed that DII was correlated with the overall physical well-being of participants. However, there was no significant association between DII and IBD.


Asunto(s)
Dieta , Inflamación , Enfermedades Inflamatorias del Intestino , Encuestas Nutricionales , Humanos , Enfermedades Inflamatorias del Intestino/epidemiología , Masculino , Femenino , Adulto , Inflamación/epidemiología , Inflamación/sangre , Dieta/efectos adversos , Persona de Mediana Edad , Factores de Riesgo , Proteína C-Reactiva/análisis , Proteína C-Reactiva/metabolismo , Estados Unidos/epidemiología
15.
Proc Natl Acad Sci U S A ; 118(3)2021 01 19.
Artículo en Inglés | MEDLINE | ID: mdl-33436411

RESUMEN

Biominerals such as seashells, coral skeletons, bone, and tooth enamel are optically anisotropic crystalline materials with unique nanoscale and microscale organization that translates into exceptional macroscopic mechanical properties, providing inspiration for engineering new and superior biomimetic structures. Using Seriatopora aculeata coral skeleton as a model, here, we experimentally demonstrate X-ray linear dichroic ptychography and map the c-axis orientations of the aragonite (CaCO3) crystals. Linear dichroic phase imaging at the oxygen K-edge energy shows strong polarization-dependent contrast and reveals the presence of both narrow (<35°) and wide (>35°) c-axis angular spread in the coral samples. These X-ray ptychography results are corroborated by four-dimensional (4D) scanning transmission electron microscopy (STEM) on the same samples. Evidence of co-oriented, but disconnected, corallite subdomains indicates jagged crystal boundaries consistent with formation by amorphous nanoparticle attachment. We expect that the combination of X-ray linear dichroic ptychography and 4D STEM could be an important multimodal tool to study nano-crystallites, interfaces, nucleation, and mineral growth of optically anisotropic materials at multiple length scales.


Asunto(s)
Antozoos/química , Biomimética , Biomineralización , Cristalinas/química , Animales , Anisotropía , Antozoos/ultraestructura , Carbonato de Calcio/química , Cristalinas/ultraestructura , Microscopía Electrónica de Transmisión de Rastreo , Minerales/química , Radiografía , Ingeniería de Tejidos , Rayos X
16.
Proc Natl Acad Sci U S A ; 118(15)2021 04 13.
Artículo en Inglés | MEDLINE | ID: mdl-33833057

RESUMEN

Structural characterization of biologically formed materials is essential for understanding biological phenomena and their enviro-nment, and for generating new bio-inspired engineering concepts. For example, nacre-the inner lining of some mollusk shells-encodes local environmental conditions throughout its formation and has exceptional strength due to its nanoscale brick-and-mortar structure. This layered structure, comprising alternating transparent aragonite (CaCO3) tablets and thinner organic polymer layers, also results in stunning interference colors. Existing methods of structural characterization of nacre rely on some form of cross-sectional analysis, such as scanning or transmission electron microscopy or polarization-dependent imaging contrast (PIC) mapping. However, these techniques are destructive and too time- and resource-intensive to analyze large sample areas. Here, we present an all-optical, rapid, and nondestructive imaging technique-hyperspectral interference tomography (HIT)-to spatially map the structural parameters of nacre and other disordered layered materials. We combined hyperspectral imaging with optical-interference modeling to infer the mean tablet thickness and its disorder in nacre across entire mollusk shells from red and rainbow abalone (Haliotis rufescens and Haliotis iris) at various stages of development. We observed that in red abalone, unexpectedly, nacre tablet thickness decreases with age of the mollusk, despite roughly similar appearance of nacre at all ages and positions in the shell. Our rapid, inexpensive, and nondestructive method can be readily applied to in-field studies.


Asunto(s)
Exoesqueleto/química , Gastrópodos/metabolismo , Nácar/análisis , Imagen Óptica/métodos , Exoesqueleto/metabolismo , Animales , Gastrópodos/citología , Imagen Óptica/instrumentación , Imagen Óptica/normas , Sensibilidad y Especificidad
17.
Proc Natl Acad Sci U S A ; 118(8)2021 02 23.
Artículo en Inglés | MEDLINE | ID: mdl-33558418

RESUMEN

The expansion of anatomically modern humans (AMHs) from Africa around 65,000 to 45,000 y ago (ca. 65 to 45 ka) led to the establishment of present-day non-African populations. Some paleoanthropologists have argued that fossil discoveries from Huanglong, Zhiren, Luna, and Fuyan caves in southern China indicate one or more prior dispersals, perhaps as early as ca. 120 ka. We investigated the age of the human remains from three of these localities and two additional early AMH sites (Yangjiapo and Sanyou caves, Hubei) by combining ancient DNA (aDNA) analysis with a multimethod geological dating strategy. Although U-Th dating of capping flowstones suggested they lie within the range ca. 168 to 70 ka, analyses of aDNA and direct AMS 14C dating on human teeth from Fuyan and Yangjiapo caves showed they derive from the Holocene. OSL dating of sediments and AMS 14C analysis of mammal teeth and charcoal also demonstrated major discrepancies from the flowstone ages; the difference between them being an order of magnitude or more at most of these localities. Our work highlights the surprisingly complex depositional history recorded at these subtropical caves which involved one or more episodes of erosion and redeposition or intrusion as recently as the late Holocene. In light of our findings, the first appearance datum for AMHs in southern China should probably lie within the timeframe set by molecular data of ca. 50 to 45 ka.


Asunto(s)
Arqueología , Cuevas/química , ADN Antiguo/análisis , Fósiles , Sedimentos Geológicos/análisis , Migración Humana/historia , Datación Radiométrica/métodos , China , Historia Antigua , Humanos
18.
Artículo en Inglés | MEDLINE | ID: mdl-38743903

RESUMEN

Background: Chronic Obstructive Pulmonary Disease (COPD) is a prevalent and impactful respiratory condition, necessitating effective interventions for improved patient outcomes. This retrospective analysis aimed to explore the efficacy of respiratory function exercise combined with psychological nursing on cardiopulmonary function index, exercise tolerance, and quality of life in patients with stable COPD. Methods: The data of 100 patients with stable COPD admitted to Cangzhou Central Hospital from June 2019 to June 2021 were retrospectively analyzed. Patients were assigned to the experimental group (n=50) and the control group (n=50) alphabetically by their initials. Patients in both groups were treated with conventional care combined with respiratory function exercise, and the experimental group additionally received psychological care intervention. Pulmonary function indicators, including forced vital capacity (FVC), forced expiratory volume in one second (FEV1), one-second rate (FEV1/FVC), 6-min walking test (6MWT) results, quality of life (physical health and role emotional), anxiety and depression self-rating scale scores, nursing satisfaction, and clinical efficacy were compared between the two groups before and after treatment. Results: The two groups presented no significant differences in baseline data (P > .05). The experimental group outperformed the control group in terms of pulmonary function index, quality of life, and nursing satisfaction (P < .001). The observation group obtained lower negative emotion scores than the control group after nursing intervention (P < .001). After nursing, the FEV1/FVC in the experimental group was significantly higher than that in the control group [(58.63 ± 5.64) vs (46.36 ± 5.23)]. The 6MWT results in the experimental group were significantly better than those in the control group [(398.35 ± 28.65) m vs (348.97 ± 26.98) m] (all P < .001). Conclusion: The results revealed that this combined approach effectively improves lung function, mitigates negative emotions, enhances nursing satisfaction, and significantly boosts the quality of life in patients with stable COPD. These findings underscore the potential clinical relevance of implementing such interventions for better COPD management and patient well-being.

19.
Int Wound J ; 21(2): e14762, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38356162

RESUMEN

Ischemic ulcers pose a multifaceted clinical dilemma for patients with atherosclerosis, frequently compounded by suboptimal wound healing mechanisms. The dual function of Transforming Growth Factor Beta 3 (TGF-ß3) in ischemic ulcer healing is not fully comprehended, despite its involvement in modulating inflammatory responses and tissue regeneration. The main aim of this investigation was to clarify the functions and mechanisms by which TGF-ß3 regulates inflammatory responses and promotes wound healing in patients with ischemic ulcers who have atherosclerosis. Between August 2022 and November 2023, this cross-sectional investigation was conducted on 428 patients diagnosed with atherosclerotic ischemic ulcers in Haikou, China. The expression and function of TGF-ß3 were examined throughout the different stages of wound healing, including inflammation, proliferation and remodelling. In addition to documenting patient demographics and ulcer characteristics, an analysis was conducted on biopsy samples to determine the expression of TGF-ß3, pro-inflammatory and anti-inflammatory markers. A subset of patients were administered topical TGF-ß3 in order to evaluate its therapeutic effects. The expression pattern of TGF-ß3 was found to be stage-dependent and significant, exhibiting increased levels during the phase of inflammation and reduced activity in subsequent phases. TGF-ß3 levels were found to be greater in ulcers that were larger and deeper, especially in inflammatory phase. TGF-ß3 applied topically induced discernible enhancement in ulcer healing parameters, such as reduction in ulcer depth and size. The therapeutic significance of TGF-ß3 was emphasised due to its twofold function of regulating the inflammatory environment and facilitating the regeneration of damaged tissues. Ischemic ulcer lesion healing is significantly influenced by TGF-ß3, which functions as an anti-inflammatory and pro-inflammatory mediator. Its correlation with ulcer characteristics and stages of healing suggests that it may have utility as a targeted therapeutic agent.


Asunto(s)
Aterosclerosis , Factor de Crecimiento Transformador beta3 , Humanos , Antiinflamatorios , Estudios Transversales , Inflamación , Factor de Crecimiento Transformador beta/análisis , Factor de Crecimiento Transformador beta/metabolismo , Factor de Crecimiento Transformador beta3/uso terapéutico , Factor de Crecimiento Transformador beta3/farmacología , Úlcera , Cicatrización de Heridas
20.
Waste Manag Res ; : 734242X241237107, 2024 Mar 18.
Artículo en Inglés | MEDLINE | ID: mdl-38497604

RESUMEN

Removing water-soluble chlorides (WSCs) through water extraction is a common pretreatment technology for recycling municipal solid waste incineration (MSWI) fly ash (FA). However, the extracted solution often contains heavy metals, the concentrations of which exceed standards for effluent. This study aims to investigate the adsorption of heavy metals by palygorskite in water-extracted solution and explore the feasibility of stabilizing heavy metals through comilling palygorskite-adsorbed heavy metals (PAHMs) with water-extracted fly ash (WFA). The experimental parameters include: two-stage water extraction with a liquid-to-solid ratio of 5, adding 0, 0.125, 0.25, 0.5, 1, 2 or 3 g of palygorskite to 100 mL of water-extracted solution, and comilling the mixture of PAHMs and WFA for 0, 0.5, 1, 2, 4, 8, 12, 24 or 96 hours. The experimental results revealed that 3 g of palygorskite in 100 mL of extracted solution could absorb Pb, Cd, Cr, Cu and Zn, meeting the effluent standards. The total amount of Pb, Cd, Cr, Cu and Zn removal rate reached 99.7%. Moreover, 98.44% of the WSCs were not adsorbed, the water extraction process for removing WSCs was not compromised. After the comilling of PAHMs and WFA, the distribution of the heavy metals in the milled blended powder was greater than 99.44%; moreover, toxicity characteristic leaching procedure concentrations were determined to conform to regulatory standards, and the sequential extraction procedure revealed that the heavy metals tended to be in stable fractions. This achieves the goal of preventing secondary pollution from heavy metals during the MSWI FA recycling process.

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