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1.
Cell ; 183(3): 730-738.e13, 2020 10 29.
Artigo em Inglês | MEDLINE | ID: mdl-32979942

RESUMO

SARS-CoV-2 is an enveloped virus responsible for the COVID-19 pandemic. Despite recent advances in the structural elucidation of SARS-CoV-2 proteins, the detailed architecture of the intact virus remains to be unveiled. Here we report the molecular assembly of the authentic SARS-CoV-2 virus using cryoelectron tomography (cryo-ET) and subtomogram averaging (STA). Native structures of the S proteins in pre- and postfusion conformations were determined to average resolutions of 8.7-11 Å. Compositions of the N-linked glycans from the native spikes were analyzed by mass spectrometry, which revealed overall processing states of the native glycans highly similar to that of the recombinant glycoprotein glycans. The native conformation of the ribonucleoproteins (RNPs) and their higher-order assemblies were revealed. Overall, these characterizations revealed the architecture of the SARS-CoV-2 virus in exceptional detail and shed light on how the virus packs its ∼30-kb-long single-segmented RNA in the ∼80-nm-diameter lumen.


Assuntos
Betacoronavirus/fisiologia , Betacoronavirus/ultraestrutura , Montagem de Vírus , Animais , Chlorocebus aethiops , Microscopia Crioeletrônica , Humanos , Espectrometria de Massas , Modelos Moleculares , Conformação Proteica , SARS-CoV-2 , Células Vero , Proteínas Virais/química , Proteínas Virais/ultraestrutura , Cultura de Vírus
2.
Cereb Cortex ; 34(5)2024 May 02.
Artigo em Inglês | MEDLINE | ID: mdl-38752980

RESUMO

The effects of hypoxia on brain function remain largely unknown. This study aimed to clarify this issue by visual-stimulated functional magnetic resonance imaging design. Twenty-three college students with a 30-d high-altitude exposure were tested before, 1 week and 3 months after returning to sea level. Brain functional magnetic resonance imaging and retinal electroretinogram were acquired. One week after returning to sea level, decreased blood oxygenation level dependent in the right lingual gyrus accompanied with increased blood oxygenation level dependent in the frontal cortex and insular cortex, and decreased amplitude of electroretinogram a-wave in right eye; moreover, the bilateral lingual gyri showed increased functional connectivity within the dorsal visual stream pathway, and the blood oxygenation level dependent signals in the right lingual gyrus showed positive correlation with right retinal electroretinogram a-wave. Three months after returning to sea level, the blood oxygenation level dependent signals recovered to normal level, while intensively increased blood oxygenation level dependent signals in a broad of brain regions and decreased retinal electroretinogram were also existed. In conclusion, hypoxic exposure has long-term effects on visual cortex, and the impaired retinal electroretinogram may contribute to it. The increased functional connectivity of dorsal stream may compensate for the decreased function of retinal photoreceptor cells to maintain normal visual function.


Assuntos
Eletrorretinografia , Imageamento por Ressonância Magnética , Plasticidade Neuronal , Vias Visuais , Humanos , Masculino , Adulto Jovem , Feminino , Plasticidade Neuronal/fisiologia , Vias Visuais/fisiologia , Vias Visuais/diagnóstico por imagem , Hipóxia/fisiopatologia , Adulto , Oxigênio/sangue , Córtex Visual/diagnóstico por imagem , Córtex Visual/fisiologia , Encéfalo/fisiologia , Encéfalo/diagnóstico por imagem , Estimulação Luminosa/métodos , Retina/fisiologia , Retina/diagnóstico por imagem , Mapeamento Encefálico/métodos
3.
J Am Chem Soc ; 146(14): 9679-9687, 2024 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-38478888

RESUMO

Jumping crystals of racemic mixtures of asparagine monohydrate have been presented in this contribution to emphasize the key role of molecular chirality in governing the direction of macroscopic motions. When heated at the specific faces of the single crystals, a pair of enantiomorphs jump in opposite directions, which are further utilized for chiral resolution. The hydrogen-bonded networks between asparagine molecules in a specific direction provide oriented channels for the escape of water molecules during the dehydration, serving as a foundation for the directional crystal jumping. Our findings not only lay the foundation for the future creation of directed actuation systems based on dynamic crystals but shall also guide the efforts to reveal the correlation between chirality and motion across diverse realms of knowledge.

4.
Anal Biochem ; 689: 115494, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38403258

RESUMO

Invasive Aspergillosis is a high-risk illness with a high death rate in immunocompromised people due to a lack of early detection and timely treatment. Based on immunology study, we achieved an efficient production of anti-galactomannan antibody by Chinese hamster ovary (CHO) cells and applied it to time-resolved fluoroimmunoassay for Aspergillus galactomannan detection. We first introduced dual promoter expression vector into CHO host cells, and then applied a two-step screening strategy to screen the stable cell line by methionine sulfoximine pressurization. After amplification and fermentation, antibody yield reached 4500 mg/L. Then we conjugated the antibodies with fluorescent microspheres to establish a double antibody sandwich time-resolved fluoroimmunoassay, which was compared with the commercial Platelia™ Aspergillus Ag by clinical serum samples. The preformed assay could obtain the results in less than 25 min, with a limit of detection for galactomannan of approximately 1 ng/mL. Clinical results of the two methods showed that the overall percent agreement was 97.7% (95% CI: 96.6%-98.4%) and Cohen's kappa coefficient was 0.94. Overall, the assay is highly consistent with commercial detection, providing a more sensitive and effective method for the rapid diagnosis of invasive aspergillosis.


Assuntos
Aspergilose , Aspergillus , Galactose/análogos & derivados , Animais , Cricetinae , Humanos , Células CHO , Cricetulus , Aspergilose/diagnóstico , Mananas , Fluorimunoensaio , Anticorpos Monoclonais
5.
Psychophysiology ; 61(6): e14548, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38385977

RESUMO

This study aimed to explore the neural mechanisms underlying high-altitude (HA) adaptation and deadaptation in perceptual processes in lowlanders. Eighteen healthy lowlanders were administered a facial S1-S2 matching task that included incomplete face (S1) and complete face (S2) photographs combined with ERP technology. Participants were tested at four time points: shortly before they departed the HA (Test 1), twenty-five days after entering the HA (Test 2), and one week (Test 3) and one month (Test 4) after returning to the lowlands. Compared with those at sea level (SL), shorter reaction times (RTs), shorter latencies of P1 and N170, and larger amplitudes of complete face N170 were found in HAs. After returning to SL, compared with that of HA, the amplitude of the incomplete face P1 was smaller after one week, and the complete face was smaller after one month. The right hemisphere N170 amplitude was greater after entering HA and one week after returning to SL than at baseline, but it returned to baseline after one month. Taken together, the current findings suggest that HA adaptation increases visual cortex excitation to accelerate perceptual processing. More mental resources are recruited during the configural encoding stage of complete faces after HA exposure. The perceptual processes affected by HA exposure are reversible after returning to SL, but the low-level processing stage differs between incomplete and complete faces due to neural compensation mechanisms. The configural encoding stage in the right hemisphere is affected by HA exposure and requires more than one week but less than one month to recover to baseline.


Assuntos
Adaptação Fisiológica , Altitude , Eletroencefalografia , Reconhecimento Facial , Humanos , Masculino , Adulto , Feminino , Adulto Jovem , Reconhecimento Facial/fisiologia , Estudos Longitudinais , Adaptação Fisiológica/fisiologia , Hipóxia/fisiopatologia , Tempo de Reação/fisiologia , Potenciais Evocados/fisiologia , Córtex Visual/fisiologia , Doença da Altitude/fisiopatologia
6.
BMC Med Res Methodol ; 24(1): 65, 2024 Mar 11.
Artigo em Inglês | MEDLINE | ID: mdl-38468223

RESUMO

BACKGROUND: The Core Outcome Measures in Effectiveness Trials (COMET) working group proposed core outcome sets (COS) to address the heterogeneity in outcome measures in clinical studies. According to the recommendations of COMET, performing systematic reviews (SRs) usually was the first step for COS development. However, the SRs that serve as a basis for COS are not specifically appraised by organizations such as COMET regarding their quality. Here, we investigated the status of SRs related to development of COS and evaluated their methodological quality. METHODS: We conducted a search on PubMed to identify SRs related to COS development published from inception to May 2022. We qualitatively summarized the disease included in SR topics, and the studies included in the SRs. We evaluated the methodological quality of the SRs using AMSTAR 2.0 and compared the overall quality of SRs with and without protocols using the Mann-Whitney U test. RESULTS: We included 175 SRs from 23 different countries or regions, and they mainly focused on five diseases: musculoskeletal system or connective tissue disease (n = 19, 10.86%), injury, poisoning, or certain other consequences of external causes (n = 18, 10.29%), digestive system disease (n = 16, 9.14%), nervous system disease (n = 15, 8.57%), and genitourinary system disease (n = 15, 8.57%). Although 88.00% of SRs included randomized controlled trials (RCTs), only a few SRs (23.38%) employed appropriate tools to assess the risk of bias in RCTs. The assessment results on the basis of AMSTAR 2.0 indicated that most SRs (93.71%) were rated as ''critically low'' to ''low'' in terms of overall confidence. The overall confidence of SRs with protocols was significantly higher than that without protocols (P <.001). Compared to the SRs with protocols on Core Outcome Measures in Effectiveness Trials (COMET), SRs with protocols on PROSPERO were of better overall confidence (P = .017). CONCLUSION: The overall quality of published SRs regarding COS development was poor. Our findings emphasize the need for researchers to carefully select the disease topic and strictly adhere to the requirements of optimal methodology when conducting a SR for the establishment of a COS.


Assuntos
Avaliação de Resultados em Cuidados de Saúde , Projetos de Pesquisa , Humanos , Revisões Sistemáticas como Assunto , Viés
7.
Mikrochim Acta ; 191(7): 383, 2024 06 11.
Artigo em Inglês | MEDLINE | ID: mdl-38861005

RESUMO

A competitive-type photoelectrochemical (PEC) aptasensor coupled with a novel Au@Cd:SnO2/SnS2 nanocomposite was designed for the detection of 17ß-estradiol (E2) in microfluidic devices. The designed Au@Cd:SnO2/SnS2 nanocomposites exhibit high photoelectrochemical activity owing to the good matching of cascade band-edge and the efficient separation of photo-generated e-/h+ pairs derived from the Cd-doped defects in the energy level. The Au@Cd:SnO2/SnS2 nanocomposites were loaded into carbon paste electrodes (CPEs) to immobilize complementary DNA (cDNA) and estradiol aptamer probe DNA (E2-Apt), forming a double-strand DNA structure on the CPE surface. As the target E2 interacts with the double-strand DNA, E2-Apt is sensitively released from the CPE, subsequently increasing the photocurrent intensity due to the reduced steric hindrance of the electrode surface. The competitive-type sensing mechanism, combined with high PEC activity of the Au@Cd:SnO2/SnS2 nanocomposites, contributed to the rapid and sensitive detection of E2 in a "signal on" manner. Under the optimized conditions, the PEC aptasensor exhibited a linear range from 1.0 × 10-13 mol L-1 to 3.2 × 10-6 mol L-1 and a detection limit of 1.2 × 10-14 mol L-1 (S/N = 3). Moreover, the integration of microfluidic device with smartphone controlled portable electrochemical workstation enables the on-site detection of E2. The small sample volume (10 µL) and short analysis time (40 min) demonstrated the great potential of this strategy for E2 detection in rat serum and river water. With these advantages, the PEC aptasensor can be utilized for point-of-care testing (POCT) in both clinical and environmental applications.


Assuntos
Aptâmeros de Nucleotídeos , Técnicas Biossensoriais , Técnicas Eletroquímicas , Estradiol , Ouro , Limite de Detecção , Nanocompostos , Sulfetos , Compostos de Estanho , Compostos de Estanho/química , Aptâmeros de Nucleotídeos/química , Nanocompostos/química , Ouro/química , Estradiol/análise , Estradiol/sangue , Estradiol/química , Técnicas Eletroquímicas/métodos , Técnicas Eletroquímicas/instrumentação , Técnicas Biossensoriais/métodos , Técnicas Biossensoriais/instrumentação , Sulfetos/química , Cádmio/química , Cádmio/análise , Processos Fotoquímicos , Dispositivos Lab-On-A-Chip
8.
Antimicrob Agents Chemother ; 67(6): e0024923, 2023 06 15.
Artigo em Inglês | MEDLINE | ID: mdl-37219437

RESUMO

Present evidence suggests that the administration of antibiotics, particularly aminopenicillins, may increase the risk of rash in children with infectious mononucleosis (IM). This retrospective, multicenter cohort study of children with IM was conducted to explore the association between antibiotic exposure in IM children and the risk of rash. A robust error generalized linear regression was performed to address the potential cluster effect, as well as confounding factors such as age and sex. A total of 767 children (aged from 0 to 18 years) with IM from 14 hospitals in Guizhou Province were included in the final analysis. The regression analysis implied that exposure to antibiotics was associated with a significantly increased incidence of overall rash in IM children (adjusted odds ratio [AOR], 1.47; 95% confidence interval [CI], ~1.04 to 2.08; P = 0.029). Of 92 overall rash cases, 43 were probably related to antibiotic exposure: two cases (4.08%) in the amoxicillin-treated group and 41 (8.15%) in the group treated with other antibiotics. Regression analysis indicated that the risk of rash induced by amoxicillin in IM children was similar to that induced by other penicillins (AOR, 1.12; 95% CI, ~0.13 to 9.67), cephalosporins (AOR, 2.45; 95% CI, ~0.43 to 14.02), or macrolides (AOR, 0.91; 95% CI, ~0.15 to 5.43). Antibiotic exposure may be associated with an increased risk of overall rash in IM children, but amoxicillin was not found to be associated with any increased risk of rash during IM compared to other antibiotics. We suggest that clinicians be vigilant against the occurrence of rash in IM children receiving antibiotic therapy, rather than indiscriminately avoiding prescribing amoxicillin.


Assuntos
Exantema , Mononucleose Infecciosa , Humanos , Criança , Antibacterianos/efeitos adversos , Estudos Retrospectivos , Mononucleose Infecciosa/tratamento farmacológico , Mononucleose Infecciosa/induzido quimicamente , Estudos de Coortes , Amoxicilina/efeitos adversos , Exantema/induzido quimicamente , Exantema/tratamento farmacológico , Exantema/epidemiologia , Penicilinas/efeitos adversos
9.
Anal Chem ; 95(11): 5053-5060, 2023 03 21.
Artigo em Inglês | MEDLINE | ID: mdl-36892972

RESUMO

Fluorescent proteins (FPs) provide a ratiometric readout for quantitative assessment of the destination of internalized biomolecules. FP-inspired peptide nanostructures that can compete with FPs in their capacity are the most preferred building blocks for the synthesis of fluorescent soft matter. However, realizing a ratiometric emission from a single peptide fluorophore remains exclusive since multicolor emission is a rare property in peptide nanostructures. Here, we describe a bioinspired peptidyl platform for ratiometric intracellular quantitation by employing a single ferrocene-modified histidine dipeptide. The intensiometric ratio of green to blue fluorescence correlates linearly with the concentration of the peptide by three orders of magnitude. The ratiometric fluorescence of the peptide is an assembly-induced emission originating from hydrogen bonds and aromatic interactions. Additionally, modular design enables ferrocene-modified histidine dipeptides to use as a general platform for the construction of intricate peptides that retain the ratiometric fluorescent properties. The ratiometric peptide technique promises flexibility in the design of a wide spectrum of stoichiometric biosensors for quantitatively understanding the trafficking and subcellular fate of biomolecules.


Assuntos
Técnicas Biossensoriais , Dipeptídeos , Dipeptídeos/química , Histidina , Metalocenos , Peptídeos/química , Corantes Fluorescentes/química , Técnicas Biossensoriais/métodos
10.
Anal Chem ; 95(21): 8284-8290, 2023 05 30.
Artigo em Inglês | MEDLINE | ID: mdl-37161261

RESUMO

Reconstruction of the miniaturized peptide to mimic the tailored functions of protein has been attractive but challenging. Herein, initialized from the crystal structure of redox-sensitive green fluorescent protein-2 (roGFP2), we propose a practical approach to construct the roGFP2 mimetic peptide by rethreading the aromatic residues adjacent to the chromophore fragment. By fine-tuning the residues of peptides, a mini tetrapeptide (Cys-Phe-Phe-His) was designed, which can act as a hydrogen peroxide sensor using its ratiometric fluorescence. The roGFP2 mimetic tetrapeptide is biocompatible and photostable and has competitive fluorescent properties with roGFP2 by the virtue of its assembly induced emissions. We expand the ratiometric tetrapeptide for sensing hydrogen peroxide in acidic chambers. The results provide a promising approach for the artificial design of miniaturized peptides with the desired function.


Assuntos
Peróxido de Hidrogênio , Peptídeos , Proteínas de Fluorescência Verde/química , Oxirredução , Fluorescência , Peptídeos/metabolismo
11.
Small ; 19(1): e2204959, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36372545

RESUMO

The self-assembly of peptidyl virus-like nanovesicles (pVLNs) composed of highly ordered peptide bilayer membranes that encapsulate the small interfering RNA (siRNA) is reported. The targeting and enzyme-responsive sequences on the bilayer's surface allow the pVLNs to enter cancer cells with high efficiency and control the release of genetic drugs in response to the subcellular environment. By transforming its structure in response to the highly expressed enzyme matrix metalloproteinase 7 (MMP-7) in cancer cells, it helps the siRNA escape from the lysosomes, resulting in a final silencing efficiency of 92%. Moreover, the pVLNs can serve as reconfigurable "Trojan horse" by transforming into membranes triggered by the MMP-7 and disrupting the cytoplasmic structure, thereby achieving synergistic anticancer effects and 96% cancer cell mortality with little damage to normal cells. The pVLNs benefit from their biocompatibility, targeting, and enzyme responsiveness, making them a promising platform for gene therapy and anticancer therapy.


Assuntos
Nanopartículas , Neoplasias , Sistemas de Liberação de Medicamentos/métodos , Metaloproteinase 7 da Matriz , RNA Interferente Pequeno/genética , Linhagem Celular Tumoral , Peptídeos/química , Nanopartículas/química , Neoplasias/tratamento farmacológico
12.
PLoS Pathog ; 17(3): e1009439, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33711082

RESUMO

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causes the global pandemic of COVID-19. SARS-CoV-2 is classified as a biosafety level-3 (BSL-3) agent, impeding the basic research into its biology and the development of effective antivirals. Here, we developed a biosafety level-2 (BSL-2) cell culture system for production of transcription and replication-competent SARS-CoV-2 virus-like-particles (trVLP). This trVLP expresses a reporter gene (GFP) replacing viral nucleocapsid gene (N), which is required for viral genome packaging and virion assembly (SARS-CoV-2 GFP/ΔN trVLP). The complete viral life cycle can be achieved and exclusively confined in the cells ectopically expressing SARS-CoV or SARS-CoV-2 N proteins, but not MERS-CoV N. Genetic recombination of N supplied in trans into viral genome was not detected, as evidenced by sequence analysis after one-month serial passages in the N-expressing cells. Moreover, intein-mediated protein trans-splicing approach was utilized to split the viral N gene into two independent vectors, and the ligated viral N protein could function in trans to recapitulate entire viral life cycle, further securing the biosafety of this cell culture model. Based on this BSL-2 SARS-CoV-2 cell culture model, we developed a 96-well format high throughput screening for antivirals discovery. We identified salinomycin, tubeimoside I, monensin sodium, lycorine chloride and nigericin sodium as potent antivirals against SARS-CoV-2 infection. Collectively, we developed a convenient and efficient SARS-CoV-2 reverse genetics tool to dissect the virus life cycle under a BSL-2 condition. This powerful tool should accelerate our understanding of SARS-CoV-2 biology and its antiviral development.


Assuntos
COVID-19/virologia , Técnicas de Cultura de Células/métodos , SARS-CoV-2/fisiologia , Antivirais/farmacologia , Contenção de Riscos Biológicos , Genoma Viral/efeitos dos fármacos , Ensaios de Triagem em Larga Escala , Humanos , SARS-CoV-2/efeitos dos fármacos , SARS-CoV-2/genética , SARS-CoV-2/crescimento & desenvolvimento , Replicação Viral/efeitos dos fármacos
13.
Microb Pathog ; 174: 105891, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36427659

RESUMO

CONTEXT: Chronic kidney disease (CKD) affects approximately 10% of the global population. The abundance of Akkermansia muciniphila (AKK) is significantly reduced in CKD patients. OBJECTIVE: This study investigated the effects of AKK bacteria on kidney damage and the renal interstitium in rats with CKD. MATERIALS AND METHODS: CKD model 5/6 nephrectomy rats were used. CKD rats were supplemented with AKK (2 × 108 cfu/0.2 mL) for 8 weeks. RESULTS: AKK administration significantly suppressed epithelial-mesenchymal transition (EMT), and high-throughput 16S rRNA pyrosequencing showed that AKK supplementation restored the disordered intestinal microecology in CKD rats. AKK also enhanced the intestinal mucosal barrier function. AKK may regulate the intestinal microecology and reduce renal interstitial fibrosis by enhancing the abundance of probiotics and reducing damage to the intestinal mucosal barrier. CONCLUSION: The results suggest that AKK administration could be a novel therapeutic strategy for treating renal fibrosis and CKD.


Assuntos
Rim , Insuficiência Renal Crônica , Ratos , Animais , RNA Ribossômico 16S/genética , Rim/patologia , Insuficiência Renal Crônica/tratamento farmacológico , Insuficiência Renal Crônica/genética , Insuficiência Renal Crônica/microbiologia , Fibrose
14.
Cell Mol Neurobiol ; 43(5): 2273-2288, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-36355226

RESUMO

Cognitive dysfunction and brain white matter (WM) injury have been found in adults exposed to hypoxia. However, the mechanisms underlying these impairments remain unclear, and moreover, it is also unclear whether these impairments are reversible after reoxygenation. In this study, adult male mice were exposed to hypoxia for 15 days at a simulated altitude of 4300 m and then reoxygenated for 2 months. Control mice were raised under normoxic conditions. Mice showed a significant decrease in arterial oxygen saturation (SaO2) and an increase in heart rate and breath rate after hypoxic exposure, and they displayed anxiety-like emotion and impaired cognitions. Hypoxic mice showed decreased brain WM fractional anisotropy (FA) and increased mean diffusion (MD) mainly in the corpus callosum and internal capsule. The reason for the adult brain WM injury was myelin rather than axon. Further, the myelin injury was due to the obstruction of oligodendrocyte precursor cells (OPCs) differentiation and eventually led to behavioral deficits. More importantly, the changes in physiological indicators, behavioral disorders, and WM injury caused by hypoxia can be recovered after reoxygenation. Taken together, our data indicate that adult brain WM injury caused by hypoxia is reversible after reoxygenation and enhancing OPCs differentiation may be a promising therapy for clinical hypoxic diseases associated with brain injury. Schematic diagram of brain WM and behavioral changes induced by hypoxia/reoxygenation in adult mice.


Assuntos
Lesões Encefálicas , Substância Branca , Animais , Masculino , Camundongos , Substância Branca/patologia , Encéfalo/patologia , Hipóxia/complicações , Hipóxia/patologia , Imageamento por Ressonância Magnética , Lesões Encefálicas/patologia
15.
Exp Physiol ; 108(7): 961-974, 2023 07.
Artigo em Inglês | MEDLINE | ID: mdl-37139700

RESUMO

NEW FINDINGS: What is the central question of this study? Is there a risk of developing diabetes associated with statin treatment? What is the underlying mechanism of the increased incidence rate of new-onset diabetes in patients treated with rosuvastatin? What is the main finding and its importance? Rosuvastatin therapy reduced intraperitoneal glucose tolerance and changed the catabolism of branched-chain amino acid (BCAAs) in white adipose tissue and skeletal muscle. Protein phosphatase 2Cm knockdown completely abolished the effects of insulin and rosuvastatin on glucose absorption. This study provides mechanistic support for recent clinical data on rosuvastatin-related new-onset diabetes and underscores the logic for intervening in BCAA catabolism to prevent the harmful effects of rosuvastatin. ABSTRACT: Accumulating evidence indicates that patients treated with rosuvastatin have an increased risk of developing new-onset diabetes. However, the underlying mechanism remains unclear. In this study, we administered rosuvastatin (10 mg/kg body weight) to male C57BL/6J mice for 12 weeks and found that oral rosuvastatin dramatically reduced intraperitoneal glucose tolerance. Rosuvastatin-treated mice showed considerably higher serum levels of branched-chain amino acids (BCAAs) than control mice. They also showed dramatically altered expression of BCAA catabolism-related enzymes in white adipose tissue and skeletal muscle, including downregulated mRNA expression of BCAT2 and protein phosphatase 2Cm (PP2Cm) and upregulated mRNA expression of branched-chain ketoacid dehydrogenase kinase (BCKDK). The levels of BCKD in the skeletal muscle were reduced in rosuvastatin-treated mice, which was associated with lower PP2Cm protein levels and increased BCKDK levels. We also investigated the effects of rosuvastatin and insulin administration on glucose metabolism and BCAA catabolism in C2C12 myoblasts. We observed that incubation with insulin enhanced glucose uptake and facilitated BCAA catabolism in C2C12 cells, which was accompanied by elevated Akt and glycogen synthase kinase 3 ß (GSK3ß) phosphorylation. These effects of insulin were prevented by co-incubation of the cells with 25 µM rosuvastatin. Moreover, the effects of insulin and rosuvastatin administration on glucose uptake and Akt and GSK3ß signaling in C2C12 cells were abolished when PP2Cm was knocked down. Although the relevance of these data, obtained with high doses of rosuvastatin in mice, to therapeutic doses in humans remains to be elucidated, this study highlights a potential mechanism for the diabetogenic effects of rosuvastatin, and suggests that BCAA catabolism could be a pharmacological target for preventing the adverse effects of rosuvastatin.


Assuntos
Diabetes Mellitus , Resistência à Insulina , Animais , Masculino , Camundongos , Aminoácidos de Cadeia Ramificada/metabolismo , Glucose , Glicogênio Sintase Quinase 3 beta , Insulina , Camundongos Endogâmicos C57BL , Fosfoproteínas Fosfatases/genética , Fosfoproteínas Fosfatases/metabolismo , Proteínas Proto-Oncogênicas c-akt , RNA Mensageiro , Rosuvastatina Cálcica/efeitos adversos
16.
Inorg Chem ; 62(29): 11633-11644, 2023 Jul 24.
Artigo em Inglês | MEDLINE | ID: mdl-37439595

RESUMO

Small-pore Lewis acid zeolites have been showing increasing potential in shape-selective reactions regarding small-molecule conversion. In this study, Sn-CHA with tunable framework Sn contents was facilely prepared via a fluoride-free, seed-assisted interzeolite conversion (IZC) pathway. Commercially available dealuminated USY functioned as the parent sample, and seeding played a vital role in accelerating the transformation process, promoting the target zeolite yield, and guiding the attached-growth pathway. Notably, a proto-zeolite phase with a semi-constructed pore structure was captured during the IZC process, which represents a crucial intermediate stage for developing the complete CHA structure and ensuring a well-defined Sn status. The detailed synthesis mechanism was explored in multiscale by a series of techniques. The obtained Sn-CHA and proto-Sn-CHA exhibited excellent catalytic performance in converting 1,3-dihydroxyacetone to methyl lactate. Proto-Sn-CHA was proven to be a highly effective glucose isomerization catalyst owing to its larger pore size and Lewis acidic nature.

17.
BMC Womens Health ; 23(1): 491, 2023 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-37715186

RESUMO

BACKGROUND: Since the connection between muscle atrophy and vitamin D and estradiol status ambiguous, this study was thus conducted to determine whether low skeletal muscle mass (SMM) in middle-aged and elderly women was affected by estradiol and vitamin D levels together. METHODS: Baseline data from a sub-cohort of the China Northwest Natural Population Cohort: Ningxia Project (CNC-NX) were analyzed. Serum 25-hydroxyvitamin D (25(OH) D) and estradiol were measured by chemiluminescence immunoassay analyzer. Bivariate logistic regression and multiplicative interaction analyses were used to assess the impact of estradiol level and vitamin D status on low SMM, as well as the combined impact of estradiol and low vitamin D status on low SMM. RESULTS: A total of 287 (9.49%) participants had low SMM, which had lower levels of estradiol and vitamin D concentration than normal SMM group. While, after adjusting the confounding variables, these correlations were maintained in estradiol Q1, Q2, Q3 and vitamin D Q1. Furthermore, the significant combined effect of the highest quartile of estradiol concentrations and non-vitamin D deficiency, and interactions between vitamin D Q1 and estradiol Q2, vitamin D Q1 and estradiol Q3, vitamin D Q2 and estradiol Q1, vitamin D Q3 and estradiol Q3 on low SMM were stably reflected (P for interaction < 0.05). CONCLUSIONS: Estradiol and vitamin D were interrelated with low SMM in middle-aged and elderly women. Combination of estradiol and vitamin D supplements should be encouraged for middle-aged and elderly women who are at risk of muscle atrophy or experiencing muscle atrophy.


Assuntos
Calcifediol , Suplementos Nutricionais , Idoso , Pessoa de Meia-Idade , Feminino , Humanos , Estradiol , Músculo Esquelético , Atrofia Muscular
18.
Radiol Med ; 128(2): 136-148, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36648615

RESUMO

This study aimed to systematically summarize the performance of the machine learning-based radiomics models in the prediction of microsatellite instability (MSI) in patients with colorectal cancer (CRC). It was conducted according to the preferred reporting items for a systematic review and meta-analysis of diagnostic test accuracy studies (PRISMA-DTA) guideline and was registered at the PROSPERO website with an identifier CRD42022295787. Systematic literature searching was conducted in databases of PubMed, Embase, Web of Science, and Cochrane Library up to November 10, 2022. Research which applied radiomics analysis on preoperative CT/MRI/PET-CT images for predicting the MSI status in CRC patients with no history of anti-tumor therapies was eligible. The radiomics quality score (RQS) and Quality Assessment of Diagnostic Accuracy Studies 2 (QUADAS-2) were applied to evaluate the research quality (full score 100%). Twelve studies with 4,320 patients were included. All studies were retrospective, and only four had an external validation cohort. The median incidence of MSI was 19% (range 8-34%). The area under the receiver operator curve of the models ranged from 0.78 to 0.96 (median 0.83) in the external validation cohort. The median sensitivity was 0.76 (range 0.32-1.00), and the median specificity was 0.87 (range 0.69-1.00). The median RQS score was 38% (range 14-50%), and half of the studies showed high risk in patient selection as evaluated by QUADAS-2. In conclusion, while radiomics based on pretreatment imaging modalities had a high performance in the prediction of MSI status in CRC, so far it does not appear to be ready for clinical use due to insufficient methodological quality.


Assuntos
Neoplasias Colorretais , Instabilidade de Microssatélites , Humanos , Neoplasias Colorretais/patologia , Aprendizado de Máquina , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada , Estudos Retrospectivos
19.
Entropy (Basel) ; 25(10)2023 Oct 13.
Artigo em Inglês | MEDLINE | ID: mdl-37895566

RESUMO

In this paper, we present the derivation of Jeffreys divergence, generalized Fisher divergence, and the corresponding De Bruijn identities for space-time random field. First, we establish the connection between Jeffreys divergence and generalized Fisher information of a single space-time random field with respect to time and space variables. Furthermore, we obtain the Jeffreys divergence between two space-time random fields obtained by different parameters under the same Fokker-Planck equations. Then, the identities between the partial derivatives of the Jeffreys divergence with respect to space-time variables and the generalized Fisher divergence are found, also known as the De Bruijn identities. Later, at the end of the paper, we present three examples of the Fokker-Planck equations on space-time random fields, identify their density functions, and derive the Jeffreys divergence, generalized Fisher information, generalized Fisher divergence, and their corresponding De Bruijn identities.

20.
Angew Chem Int Ed Engl ; 62(41): e202309830, 2023 Oct 09.
Artigo em Inglês | MEDLINE | ID: mdl-37602955

RESUMO

Covalent regulatory systems of enzymes are widely used to modulate biological enzyme activities. Inspired by the regulation of reactive-site phosphorylation in organisms, we developed peptide-based catecholase mimetics with switchable catalytic activity and high selectivity through the co-assembly of nanofibers comprising peptides and copper ions (Cu2+ ). Through careful design and modification of the peptide backbone structure based on the change in the free energy of the system, we identified the peptide with the most effective reversible catalytic activity. Kinase/phosphatase switches were used to control the reversible transition of nanofiber formation and depolymerization, as well as to modulate the active-site microenvironment. Notably, the self-assembly and disassembly processes of nanofibers were simulated using coarse-grained molecular dynamics. Furthermore, theoretical calculations confirmed the coordination of the peptide and Cu2+ , forming a zipper-like four-ligand structure at the catalytically active center of the nanofibers. Additionally, we conducted a comprehensive analysis of the catalytic mechanism. This study opens novel avenues for designing biomimetic enzymes with ordered structures and dynamic catalytic activities.

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