Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 79
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
Nano Lett ; 2024 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-38838340

RESUMO

Cancer immunotherapies based on cytotoxic CD8+ T lymphocytes (CTLs) are highly promising for cancer treatment. The specific interaction between T-cell receptors and peptide-MHC-I complexes (pMHC-I) on cancer cell membranes critically determines their therapeutic outcomes. However, the lack of appropriate endogenous antigens for MHC-I presentation disables tumor recognition by CTLs. By devising three antigen-loaded self-assembling peptides of pY-K(Ag)-ERGD, pY-K(Ag)-E, and Y-K(Ag)-ERGD to noncovalently generate light-activatable supramolecular antigens at tumor sites in different manners, we report pY-K(Ag)-ERGD as a promising candidate to endow tumor cells with pMHC-I targets on demand. Specifically, pY-K(Ag)-ERGD first generates low-antigenic supramolecular antigens on cancer cell membranes, and a successive light pulse allows antigen payloads to efficiently release from the supramolecular scaffold, directly producing antigenic pMHC-I. Intravenous administration of pY-K(Ag)-ERGD enables light-controlled tumor inhibition when combined with adoptively transferred antigen-specific CTLs. Our strategy is feasible for broadening tumor antigen repertoires for T-cell immunotherapies and advancing precision-controlled T-cell immunotherapies.

2.
Mikrochim Acta ; 191(7): 387, 2024 06 13.
Artigo em Inglês | MEDLINE | ID: mdl-38869719

RESUMO

A novel construction strategy is introduced for an ultrasensitive dynamic light scattering (DLS) immunosensor targeting alpha fetoprotein (AFP). This approach relies on a self-assembled heptamer fusion protein (A1-C4bpα), incorporating the dual functions of multivalent recognition and crosslinking aggregation amplification due to the presence of seven AFP-specific A1 nanobodies on the A1-C4bpα heptamer. Leveraging antibody-functionalized magnetic nanoparticles for target AFP capture and DLS signal output, the proposed heptamer-assisted DLS immunosensor offers high sensitivity, strong specificity, and ease of operation. Under the optimized conditions, the designed DLS immunosensor demonstrates excellent linear detection of AFP in the concentration range 0.06 ng mL-1 to 512 ng mL-1, with a detection limit of 15 pg mL-1. The selectivity, accuracy, precision, practicability, and reliability of this newly developed method were further validated through an assay of AFP levels in spiked and actual human serum samples. This work introduces a novel approach for constructing ultrasensitive DLS immunosensors, easily extendable to the sensitive determination of other targets via simply replacing the nanobody sequence, holding great promise in various applications, particularly in disease diagnosis.


Assuntos
Difusão Dinâmica da Luz , Limite de Detecção , alfa-Fetoproteínas , alfa-Fetoproteínas/análise , alfa-Fetoproteínas/imunologia , Humanos , Imunoensaio/métodos , Anticorpos Imobilizados/imunologia , Técnicas Biossensoriais/métodos , Anticorpos de Domínio Único/química , Anticorpos de Domínio Único/imunologia , Nanopartículas de Magnetita/química
3.
Nano Lett ; 23(16): 7665-7674, 2023 08 23.
Artigo em Inglês | MEDLINE | ID: mdl-37535903

RESUMO

Precise manipulation of cancer cell death by harnessing reactive oxygen species (ROS) is a promising strategy to defeat malignant tumors. However, it is quite difficult to produce active ROS with spatial precision and regulate their biological outcomes. We succeed here in selectively generating short-lived and lipid-reactive hydroxyl radicals (•OH) adjacent to cancer cell membranes, successively eliciting lipid peroxidation and ferroptosis. DiFc-K-pY, a phosphorylated self-assembling precursor that consists of two branched Fc moieties and interacts specifically with epidermal growth factor receptor, can in situ produce membrane-bound nanofibers and enrich ferrocene moieties on cancer cell membranes in response to alkaline phosphatase. Within the acidic tumor microenvironment, DiFc-K-pY nanofibers efficiently convert tumoral H2O2 to active •OH around the target cell membranes via Fenton-like reactions, leading to lipid peroxidation and ferroptosis with good cellular selectivity. Our strategy successfully prevents tumor progression with acceptable biocompatibility through intratumoral administration.


Assuntos
Nanofibras , Neoplasias , Humanos , Espécies Reativas de Oxigênio/metabolismo , Metalocenos , Peróxido de Hidrogênio/metabolismo , Morte Celular , Neoplasias/terapia , Oxirredução , Linhagem Celular Tumoral , Microambiente Tumoral
4.
J Am Chem Soc ; 145(8): 4366-4371, 2023 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-36669158

RESUMO

Innovative methods for engineering cancer cell membranes promise to manipulate cell-cell interactions and boost cell-based cancer therapeutics. Here, we illustrate an in situ approach to selectively modify cancer cell membranes by employing an enzyme-instructed peptide self-assembly (EISA) strategy. Using three phosphopeptides (pY1, pY2, and pY3) targeting the membrane-bound epidermal growth factor receptor (EGFR) and differing in just one phosphorylated tyrosine, we reveal that site-specific phosphorylation patterns in pY1, pY2, and pY3 can distinctly command their preorganization levels, self-assembling kinetics, and spatial distributions of the resultant peptide assemblies in cellulo. Overall, pY1 is the most capable of producing preorganized assemblies and shows the fastest dephosphorylation reaction in the presence of alkaline phosphatase (ALP), as well as the highest binding affinity for EGFR after dephosphorylation. Consequently, pY1 exhibits the greatest capacity to construct stable peptide assemblies on cancer cell membranes with the assistance of both ALP and EGFR. We further use peptide-protein and peptide-peptide co-assembly strategies to apply two types of antigens, namely ovalbumin (OVA) protein and dinitrophenyl (DNP) hapten respectively, on cancer cell membranes. This study demonstrates a very useful technique for the in situ construction of membrane-bound peptide assemblies around cancer cells and implies a versatile strategy to artificially enrich cancer cell membrane components for potential cancer immunotherapy.


Assuntos
Neoplasias , Humanos , Neoplasias/metabolismo , Receptores ErbB/metabolismo , Membrana Celular/metabolismo , Fosforilação , Fosfopeptídeos/metabolismo , Fosfatase Alcalina/metabolismo
5.
Int J Mol Sci ; 24(18)2023 Sep 08.
Artigo em Inglês | MEDLINE | ID: mdl-37762143

RESUMO

Metabolic diseases are growing in prevalence worldwide. Although the pathogenesis of metabolic diseases remains ambiguous, the correlation between cyclic GMP-AMP synthase (cGAS)-stimulator of interferon gene (STING) and metabolic diseases has been identified recently. Exercise is an effective intervention protecting against metabolic diseases, however, the role of the cGAS-STING signaling pathway in this process is unclear, and the effect and mechanism of different exercise intensities on metabolic disorders are still unknown. Thus, we explored the association between exercise to ameliorate HFD-induced metabolic disorders and the cGAS-STING signaling pathway and compared the effects of high-intensity interval training (HIIT) and moderate-intensity continuous training (MICT). Male C57BL/6 mice (6-8 weeks old) were fed HFD for 8 weeks to establish a metabolic disease model and were subjected to 8-week MICT or HIIT training. Glucose tolerance tests (GTT) and insulin tolerance tests (ITT) were used to assess glucose metabolism. Serum triglyceride (TG) and total cholesterol (TC) were measured to evaluate lipid metabolism. Oil red staining was used to observe the lipid droplets in the gastrocnemius muscle. An enzyme-linked immunosorbent assay was used to detect the serum inflammatory factors IL-6 and IFN-ß. The protein expression of the cGAS-STING signaling pathway was detected by the WesTM automatic protein expression analysis system. We reported that HFD induced metabolic disorders with obesity, abnormal glucolipid metabolism, and significant inflammatory responses. Both HIIT and MICT ameliorated the above adverse reactions, but MICT was superior to HIIT in improving glucolipid disorders. Additionally, HIIT significantly increased the expression of STING protein, as well as the phosphorylation of TBKI and the ratio of p-IRF3/IRF3. MICT only increased the expression of STING protein. Our findings suggest that HIIT may alleviate HFD-induced metabolic disorder phenotype through the cGAS-STING signaling pathway. However, the improvement of MICT on metabolic disorder phenotype is less associated with the cGAS-STING pathway, which needs to be further explored.


Assuntos
Treinamento Intervalado de Alta Intensidade , Doenças Metabólicas , Camundongos , Animais , Masculino , Dieta Hiperlipídica/efeitos adversos , Camundongos Endogâmicos C57BL , Transdução de Sinais/fisiologia , Nucleotidiltransferases/genética , Nucleotidiltransferases/metabolismo , Doenças Metabólicas/etiologia , Doenças Metabólicas/terapia , Interferons
6.
Anal Chem ; 94(6): 2812-2819, 2022 02 15.
Artigo em Inglês | MEDLINE | ID: mdl-34982528

RESUMO

The pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has lasted for almost 2 years. Stemming its spread has posed severe challenges for clinical virus detection. A long turnaround time, complicated operation, and low accuracy have become bottlenecks in developing detection techniques. Adopting a direct antigen detection strategy, we developed a fast-responding and quantitative capacitive aptasensor for ultratrace nucleocapsid protein detection based on a low-cost microelectrode array (MEA) chip. Employing the solid-liquid interface capacitance with a sensitivity of picofarad level, the tiny change on the MEA surface can be definitively detected. As a result, the limit of detection reaches an ultralow level of femtogram per milliliter in different matrices. Integrated with efficient microfluidic enrichment, the response time of this sensor from the sample to the result is shortened to 15 s, completely meeting the real-time detection demand. Moreover, the wide linear range of the sensor is from 10-5 to 10-2 ng/mL, and a high selectivity of 6369:1 is achieved. After application and evaluation in different environmental and body fluid matrices, this sensor and the detection method have proved to be a label-free, real-time, easy-to-operate, and specific strategy for SARS-CoV-2 screening and diagnosis.


Assuntos
COVID-19 , Proteínas do Nucleocapsídeo de Coronavírus/isolamento & purificação , COVID-19/diagnóstico , Humanos , Microeletrodos , Microfluídica , Fosfoproteínas/isolamento & purificação , SARS-CoV-2
7.
Proc Natl Acad Sci U S A ; 116(23): 11253-11258, 2019 06 04.
Artigo em Inglês | MEDLINE | ID: mdl-31097588

RESUMO

The structural polymorphism in ß-amyloid (Aß) plaques from Alzheimer disease (AD) has been recognized as an important pathological factor. Plaques from sporadic AD patients contain fibrillar deposits of various amyloid proteins/peptides, including posttranslational modified Aß (PTM-Aß) subtypes. Although many PTM-Aßs were shown to accelerate the fibrillation process, increase neuronal cytotoxicity of aggregates, or enhance the stability of fibrils, the contribution of PTM-Aßs to structural polymorphisms and their pathological roles remains unclear. We report here the NMR-based structure for the Ser-8-phosphorylated 40-residue Aß (pS8-Aß40) fibrils, which shows significant difference to the wild-type fibrils, with higher cross-seeding efficiency and thermodynamic stability. Given these physicochemical properties, the structures originated from pS8-Aß40 fibrils may potentially dominate the polymorphisms in the mixture of wild-type and phosphorylated Aß deposits. Our results imply that Aß subtypes with "seeding-prone" properties may influence the polymorphisms of amyloid plaques through the cross-seeding process.


Assuntos
Peptídeos beta-Amiloides/química , Doença de Alzheimer/metabolismo , Amiloide/química , Humanos , Espectroscopia de Ressonância Magnética/métodos , Estrutura Molecular , Fragmentos de Peptídeos/química , Fosforilação/fisiologia , Placa Amiloide/química
8.
J Med Internet Res ; 23(1): e26089, 2021 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-33400682

RESUMO

BACKGROUND: China is at the forefront of global efforts to develop COVID-19 vaccines and has five fast-tracked candidates at the final-stage, large-scale human clinical trials testing phase. Vaccine-promoting policymaking for public engagement is a prerequisite for social mobilization. However, making an informed and judicious choice is a dilemma for the Chinese government in the vaccine promotion context. OBJECTIVE: In this study, public opinions in China were analyzed via dialogues on Chinese social media, based on which Chinese netizens' views on COVID-19 vaccines and vaccination were investigated. We also aimed to develop strategies for promoting vaccination programs in China based on an in-depth understanding of the challenges in risk communication and social mobilization. METHODS: We proposed a novel behavioral dynamics model, SRS/I (susceptible-reading-susceptible/immune), to analyze opinion transmission paradigms on Chinese social media. Coupled with a meta-analysis and natural language processing techniques, the emotion polarity of individual opinions was examined in their given context. RESULTS: We collected more than 1.75 million Weibo messages about COVID-19 vaccines from January to October 2020. According to the public opinion reproduction ratio (R0), the dynamic propagation of those messages can be classified into three periods: the ferment period (R01=1.1360), the revolution period (R02=2.8278), and the transmission period (R03=3.0729). Topics on COVID-19 vaccine acceptance in China include price and side effects. From September to October, Weibo users claimed that the vaccine was overpriced, making up 18.3% (n=899) of messages; 38.1% (n=81,909) of relevant topics on Weibo received likes. On the contrary, the number of messages that considered the vaccine to be reasonably priced was twice as high but received fewer likes, accounting for 25.0% (n=53,693). In addition, we obtained 441 (47.7%) positive and 295 (31.9%) negative Weibo messages about side effects. Interestingly, inactivated vaccines instigated more heated discussions than any other vaccine type. The discussions, forwards, comments, and likes associated with topics related to inactivated vaccines accounted for 53% (n=588), 42% (n=3072), 56% (n=3671), and 49% (n=17,940), respectively, of the total activity associated with the five types of vaccines in China. CONCLUSIONS: Most Chinese netizens believe that the vaccine is less expensive than previously thought, while some claim they cannot afford it for their entire family. The findings demonstrate that Chinese individuals are inclined to be positive about side effects over time and are proud of China's involvement with vaccine development. Nevertheless, they have a collective misunderstanding about inactivated vaccines, insisting that inactivated vaccines are safer than other vaccines. Reflecting on netizens' collective responses, the unfolding determinants of COVID-19 vaccine acceptance provide illuminating benchmarks for vaccine-promoting policies.


Assuntos
Vacinas contra COVID-19/administração & dosagem , COVID-19/prevenção & controle , Mídias Sociais/estatística & dados numéricos , Vacinação/psicologia , COVID-19/epidemiologia , COVID-19/imunologia , China/epidemiologia , Humanos , Pandemias , SARS-CoV-2/imunologia , SARS-CoV-2/isolamento & purificação , Vacinação/métodos , Vacinação/estatística & dados numéricos
9.
Anal Chem ; 92(3): 2435-2442, 2020 02 04.
Artigo em Inglês | MEDLINE | ID: mdl-31904935

RESUMO

The process and mechanism of silk degradation is still a bewildering mystery in the investigation and conservation of cultural relics, which rely on the development of accurate and tailored analysis technologies. Here, two advanced approaches, proteomics and immunology, were developed for determining the deterioration behavior of historic silk fabrics and artificially aged samples from the molecular to the holistic level. The surface morphology and secondary structure of silk were destroyed during degradation. Subsequently, the proteomics and immunology analysis demonstrated a new degradation model differing from previous reports. First, the amorphous region and the looser crystalline regions were destroyed together, and the macromolecular chains were broken randomly. Then, the tight ß-sheet blocks in the crystalline region were exposed and deteriorated, which expedited the degradation of tight ß-sheet blocks and relatively loose blocks in the crystalline domain as well as the amorphous domain, ultimately yielding small molecule polypeptides. However, the deterioration process of ancient fabrics could be accelerated by poor burial conditions, thus showing distinct destructive characteristics. Overall, the results gave us a more comprehensive and profound understanding of the degradation process of ancient silk.


Assuntos
Fibroínas/análise , Proteômica , Seda/química , Animais , Bombyx , Fibroínas/imunologia , Seda/imunologia
10.
Nanotechnology ; 31(19): 195103, 2020 May 08.
Artigo em Inglês | MEDLINE | ID: mdl-31978912

RESUMO

The integration of chemotherapy drugs and photosensitizers to form versatile nanoplatforms for achieving chemo-photodynamic synergetic therapy has shown great superiority in tumor theranostic applications. We constructed pH-responsive nanoparticles (DOX/PB NPs) encapsulating the chemotherapeutic drug doxorubicin (DOX) into the cores of PLGA NPs coated with bovine serum albumin (BSA) via a water-in-oil (W/O/W) emulsion method. A simple and efficient chemo-photodynamic synergetic nanoplatform (DOX/PB@Ce6 NPs) was obtained by the adsorption of photosensitizer chlorin e6 (Ce6) onto the surface of the DOX/PB NPs. With optimal size, pH-responsive drug release behavior and excellent singlet oxygen production, the DOX/PB@Ce6 NPs have the potential to enhance anti-tumor efficiency. The cellular uptake, cytotoxicity, chemo-photodynamic synergetic effect and biocompatibility of the NPs were evaluated based on HeLa cells via in vitro experiments. The in vitro chemo-photodynamic synergetic experiments indicated that the DOX/PB@Ce6 NPs had remarkable cancer cell killing efficiency under laser irradiation. Notably, by hemolysis assay, all the NPs displayed excellent blood compatibility and were expected to be applicable for intravenous injection. In summary, the designed DOX/PB@Ce6 NPs multifunctional theranostic nanoplatform had excellent reactive oxygen species generation and would be a potential therapeutic platform for chemo-photodynamic synergetic therapy.


Assuntos
Antibióticos Antineoplásicos/farmacologia , Doxorrubicina/farmacologia , Porfirinas/farmacologia , Radiossensibilizantes/farmacologia , Antibióticos Antineoplásicos/química , Cápsulas , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Clorofilídeos , Doxorrubicina/química , Sinergismo Farmacológico , Células HeLa , Humanos , Concentração de Íons de Hidrogênio , Nanopartículas , Tamanho da Partícula , Fotoquimioterapia , Fármacos Fotossensibilizantes , Porfirinas/química , Radiossensibilizantes/química , Espécies Reativas de Oxigênio/metabolismo
11.
BMC Pregnancy Childbirth ; 20(1): 604, 2020 Oct 08.
Artigo em Inglês | MEDLINE | ID: mdl-33032548

RESUMO

BACKGROUND: Pregnancy tests can be used for the early diagnosis of fetal problems and can prevent abnormal birth in pregnancies. Yet, testing preferences among Chinese women are poorly investigated. METHODS: We developed a Discrete Choice Experiment with 5 attributes: test procedure, detection rate, miscarriage rate, time to wait for result, and test cost. By studying the choices that the women make in the hypothetical scenarios and comparing the attributes and levels, we can analyze the women's preference of prenatal testing in China. RESULTS: Ninety-two women completed the study. Respondents considered the test procedure as the most important attribute, followed by detection rate, miscarriage rate, wait time for result, and test cost, respectively. The estimated preference weight for the non-invasive procedure was 0.928 (P < 0.0001). All other attributes being equal, the odds of choosing a non-invasive testing procedure over an invasive one was 2.53 (95% confidence interval, 2.42-2.64; P < 0.001). Participants were willing to pay up to RMB$28,810 (approximately US$4610) for a non-invasive test, RMB$6061(US$970) to reduce the miscarriage rate by 1% and up to RMB$3356 (US$537) to increase the detection rate by 1%. Compared to other DCE (Discrete Choice Experiment) studies regarding Down's syndrome screening, women in our study place relatively less emphasis on test safety. CONCLUSIONS: The present study has shown that Chinese women place more emphasis on detection rate than test safety. Chinese women place great preference on noninvasive prenatal testing, which indicate a popular need of incorporating noninvasive prenatal testing into the health insurance coverage in China. This study provided valuable evidence for the decision makers in the Chinese government.


Assuntos
Aborto Espontâneo/prevenção & controle , Comportamento de Escolha , Síndrome de Down/diagnóstico , Preferência do Paciente/estatística & dados numéricos , Diagnóstico Pré-Natal/psicologia , Aborto Espontâneo/etiologia , Adulto , China , Feminino , Humanos , Preferência do Paciente/economia , Preferência do Paciente/psicologia , Gravidez , Diagnóstico Pré-Natal/efeitos adversos , Diagnóstico Pré-Natal/economia , Diagnóstico Pré-Natal/estatística & dados numéricos , Inquéritos e Questionários/estatística & dados numéricos
12.
Mol Cell Neurosci ; 99: 103394, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31356881

RESUMO

Dendritic spines on the dendrites of pyramidal neurons are one of the most important components for excitatory synapses, where excitatory information exchanges and integrates. The defects of dendritic spine development have been closely connected with many nervous system diseases including autism, intellectual disability and so forth. Based on our previous studies, we here report a new functional signaling link between phospholipase D1 (PLD1) and protein kinase D1 (PKD1) in dendritic spine morphogenesis. Coimmunoprecipitation assays showed that PLD1 associates with PKD1. A series of knocking down and rescuing experiments demonstrated that PLD1 acts upstream of PKD1 in positively regulating dendritic spine morphogenesis. Using PLD1 inhibitor, we found that PLD1 activates PKD1 to promote dendritic spine morphogenesis. Thus, we further reveal the roles of the two different enzymes in neuronal development.


Assuntos
Espinhas Dendríticas/metabolismo , Neurogênese , Fosfolipase D/metabolismo , Canais de Cátion TRPP/metabolismo , Animais , Linhagem Celular , Células Cultivadas , Espinhas Dendríticas/fisiologia , Camundongos , Fosfolipase D/antagonistas & inibidores , Ligação Proteica , Ratos , Ratos Sprague-Dawley
13.
J Med Internet Res ; 22(11): e22639, 2020 11 16.
Artigo em Inglês | MEDLINE | ID: mdl-33156807

RESUMO

BACKGROUND: In the context of the COVID-19 infodemic, the global profusion of monikers and hashtags for COVID-19 have found their way into daily communication and contributed to a backlash against China and the Chinese people. OBJECTIVE: This study examines public engagement in crisis communication about COVID-19 during the early epidemic stage and the practical strategy of social mobilization to mitigate the infodemic. METHODS: We retrieved the unbiased values of the top-ranked search phrases between December 30, 2019, and July 15, 2020, which normalized the anonymized, categorized, and aggregated samples from Google Search data. This study illustrates the most-searched terms, including the official COVID-19 terms, the stigmatized terms, and other controls, to measure the collective behavioral propensities to stigmatized terms and to explore the global reaction to the COVID-19 epidemic in the real world. We calculated the ratio of the cumulative number of COVID-19 cases to the regional population as the cumulative rate (R) of a specific country or territory and calculated the Gini coefficient (G) to measure the collective heterogeneity of crowd behavior. RESULTS: People around the world are using stigmatizing terms on Google Search, and these terms were used earlier than the official names. Many stigmatized monikers against China (eg, "Wuhan pneumonia," G=0.73; "Wuhan coronavirus," G=0.60; "China pneumonia," G=0.59; "China coronavirus," G=0.52; "Chinese coronavirus," G=0.50) had high collective heterogeneity of crowd behavior between December 30, 2019, and July 15, 2020, while the official terms "COVID-19" (G=0.44) and "SARS-CoV-2" (G=0.42) have not become de facto standard usages. Moreover, the pattern of high consistent usage was observed in 13 territories with low cumulative rates (R) between January 16 and July 15, 2020, out of 58 countries and territories that have reported confirmed cases of COVID-19. In the scientific literature, multifarious naming practices may have provoked unintended negative impacts by stigmatizing Chinese people. The World Health Organization; the United Nations Educational, Scientific and Cultural Organization; and the media initiated campaigns for fighting back against the COVID-19 infodemic with the same mission but in diverse voices. CONCLUSIONS: Infodemiological analysis can articulate the collective propensities to stigmatized monikers across search behaviors, which may reflect the collective sentiment of backlash against China and Chinese people in the real world. The full-fledged official terms are expected to fight back against the resilience of negative perceptual bias amid the COVID-19 epidemic. Such official naming efforts against the infodemic should be met with a fair share of identification in scientific conventions and sociocultural paradigms. As an integral component of preparedness, appropriate nomenclatures should be duly assigned to the newly identified coronavirus, and social mobilization in a uniform voice is a priority for combating the next infodemic.


Assuntos
COVID-19/epidemiologia , Pandemias/estatística & dados numéricos , PubMed/tendências , SARS-CoV-2/patogenicidade , Humanos
14.
Biophys J ; 117(8): 1524-1535, 2019 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-31570231

RESUMO

We investigate the variability in the dynamics of the disordered N-terminal domain of amyloid-ß fibrils (Aß), comprising residues 1-16 of Aß1-40, due to post-translational modifications and mutations in the ß-bend regions known to modulate aggregation properties. Using 2H static solid-state NMR approaches, we compare the dynamics in the wild-type Aß fibrils in the threefold symmetric polymorph with the fibrils from three post-translational modification sequences: isoaspartate-D7, the phosphorylation of S8, and an N-terminal truncation ΔE3. Additional comparisons are made with the mutants in the ß-bend region (residues 21-23) corresponding to the familial Osaka E22Δ deletion and D23N Iowa mutation. We also include the aggregates induced by Zn2+ ions. The dynamics are probed at the F4 and G9 positions. The main motional model involves two free states undergoing diffusion and conformational exchanges with the bound state in which the diffusion is quenched because of transient interactions involving fibril core and other intrastrand contacts. The fraction of the bound state increases in a sigmoidal fashion with a decrease in temperature. There is clear variability in the dynamics: the phosphorylation of S8 variant is the most rigid at the G9 site in line with structural studies, the ΔE3 fibrils are more flexible at the G9 site in line with the morphological fragmentation pattern, the Zn-induced aggregates are the most mobile, and the two ß-bend mutants have the strongest changes at the F4 site toward higher rigidity. Overall, the changes underlie the potential role of conformational ensembles in setting the stage for aggregation-prone states.


Assuntos
Peptídeos beta-Amiloides/química , Mutação , Processamento de Proteína Pós-Traducional , Peptídeos beta-Amiloides/genética , Peptídeos beta-Amiloides/metabolismo , Simulação de Dinâmica Molecular , Fosforilação , Domínios Proteicos , Multimerização Proteica , Zinco/metabolismo
15.
J Biol Chem ; 292(7): 2611-2623, 2017 02 17.
Artigo em Inglês | MEDLINE | ID: mdl-28031462

RESUMO

Polymorphism of amyloid-ß (Aß) fibrils, implying different fibril structures, may play important pathological roles in Alzheimer's disease (AD). Morphologies of Aß fibrils were found to be sensitive to fibrillation conditions. Herein, the Ser8-phosphorylated Aß (pAß), which is assumed to specially associate with symptomatic AD, is reported to modify the morphology, biophysical properties, cellular toxicity, and structures of Aß fibrils. Under the same fibrillation conditions, pAß favors the formation of fibrils (Fpß), which are different from the wild-type Aß fibrils (Fß). Both Fß and Fpß fibrils show single predominant morphologies. Compared with Fß, Fpß exhibits higher propagation efficiency and higher neuronal cell toxicity. The residue-specific structural differences between the Fß- and Fpß-seeded Aß fibrils were identified using magic angle spin NMR. Our results suggest a potential regulatory mechanism of phosphorylation on Aß fibril formation in AD and imply that the post-translationally modified Aß, especially the phosphorylated Aß, may be an important target for the diagnosis or treatment of AD at specific stages.


Assuntos
Doença de Alzheimer/metabolismo , Peptídeos beta-Amiloides/metabolismo , Amiloide/metabolismo , Fragmentos de Peptídeos/metabolismo , Serina/metabolismo , Doença de Alzheimer/patologia , Sequência de Aminoácidos , Peptídeos beta-Amiloides/química , Peptídeos beta-Amiloides/ultraestrutura , Dicroísmo Circular , Humanos , Espectroscopia de Ressonância Magnética , Microscopia Eletrônica de Transmissão , Fragmentos de Peptídeos/química , Fragmentos de Peptídeos/ultraestrutura , Fosforilação , Conformação Proteica , Espectrometria de Fluorescência , Espectroscopia de Infravermelho com Transformada de Fourier
16.
Nanotechnology ; 29(10): 105403, 2018 Mar 09.
Artigo em Inglês | MEDLINE | ID: mdl-29319002

RESUMO

MoS2 quantum dots (QDs) that are 5 nm in size were deposited on the surface of ultrathin TiO2 nanotubes (TNTs) with 5 nm wall thickness by using an improved hydrothermal method to form a MoS2 QDs@TNT visible-light photocatalyst. The ultrathin TNTs with high percentage of photocatalytic reactive facets were fabricated by the commercially available TiO2 nanoparticles (P25) through an improved hydrothermal method, and the MoS2 QDs were acquired by using a surfactant-assisted technique. The novel MoS2 QDs@TNT photocatalysts showed excellent photocatalytic activity with a decolorization rate of 92% or approximately 3.5 times more than that of pure TNTs for the high initial concentration of methylene blue solution (20 mg l-1) within 40 min under visible-light irradiation. MoS2 as the co-catalysts favored the broadening of TNTs into the visible-light absorption scope. The quantum confinement and edge effects of the MoS2 QDs and the heterojunction formed between the MoS2 QDs and TNTs efficiently extended the lifetime of photoinduced charges, impeded the recombination of photoexcited electron-hole pairs, and improved the visible-light-driven high-efficiency photocatalysis.

17.
Med Sci Monit ; 23: 1768-1774, 2017 Apr 12.
Artigo em Inglês | MEDLINE | ID: mdl-28400549

RESUMO

BACKGROUND Prostate carcinoma (PCa) is often not diagnosed until advanced disease with bone metastasis. Predictive factors for bone metastasis are required to improve patient outcomes. The study aimed to analyze the factors associated with bone metastases in newly diagnosed patients with PCa. MATERIAL AND METHODS This was a retrospective study of 80 patients newly diagnosed with PCa by pathological examination between January 2012 and December 2014. Bone metastases were diagnosed by positron emission computed tomography. Clinical data, serological laboratory results, and pathological examination results were collected. RESULTS Among the 80 patients, 45 (56%) had bone metastases. Age, serum alkaline phosphatase, prostate-specific antigen (PSA), erythrocyte sedimentation rate, PCa tissue Gleason score, androgen receptor (AR) expression, and Ki-67 expression were higher in patients with bone metastasis compared with those without (all P<0.05). Multivariate logistic regression showed that PSA (OR: 1.005; 95%CI: 1.001-1.010; P=0.016), Gleason score (OR: 4.095; 95%CI: 1.592-10.529; P=0.003), and AR expression (OR: 14.023; 95%CI: 3.531-55.6981; P=0.005) were independently associated with bone metastases. Cut-off values for PSA, Gleason score, and AR expression were 67.1 ng/ml (sensitivity: 55.6%; specificity: 97.1%), 7.5 (sensitivity: 75.6%; specificity: 82.9%), and 2.5 (sensitivity: 84.0%; specificity: 91.4%), respectively. CONCLUSIONS PSA, Gleason score, and AR expression in PCa tissues were independently associated with PCa bone metastases. These results could help identifying patients with PCa at high risk of bone metastases.


Assuntos
Neoplasias Ósseas/secundário , Calicreínas/sangue , Antígeno Prostático Específico/sangue , Neoplasias da Próstata/patologia , Receptores Androgênicos/biossíntese , Idoso , Idoso de 80 Anos ou mais , Biomarcadores Tumorais/sangue , Biomarcadores Tumorais/metabolismo , Neoplasias Ósseas/diagnóstico por imagem , Neoplasias Ósseas/metabolismo , Humanos , Imuno-Histoquímica , Masculino , Pessoa de Meia-Idade , Gradação de Tumores , Metástase Neoplásica , Tomografia por Emissão de Pósitrons , Valor Preditivo dos Testes , Prognóstico , Neoplasias da Próstata/diagnóstico por imagem , Neoplasias da Próstata/metabolismo , Receptores Androgênicos/sangue , Estudos Retrospectivos
18.
Int Immunopharmacol ; 127: 111413, 2024 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-38118318

RESUMO

BACKGROUND: The leading course of death in patients with advanced hepatocellular carcinoma (HCC) is intrahepatic progression and associated hepatic failure. The study aimed to evaluate the efficacy of locoregional therapy targeting intrahepatic lesions after intrahepatic progression for advanced HCC. METHODS: Consecutive 263 HCC patients who received lenvatinib combined with immunotherapy were reviewed. Until to last follow-up, 178 patients had disease progression:107 patients had intrahepatic progression (IP group) with or without extrahepatic progression, and 71 patients only had extrahepatic progression (EP group). After intrahepatic progression, 47 patients received systemic therapy (Systemic group), 23 patients received locoregional-systemic therapy (Loco-systemic group), and 37 patients received best supportive therapy (Supportive group). RESULTS: The EP group showed significantly longer OS (overall survival) than the IP group (not reached vs 16.2 months, P = 0.009). Median OS was significantly longer in the Loco-systemic group (20.3 v 8.8 months; P = 0.03) than in the Systemic group. The median PFS (progression-free survival) was 11.7 months in the Loco-systemic group and 5.3 months in the Systemic group (P = 0.046). In patients who progressed fast in first-line treatment, there was no significant difference in OS and PFS between the two groups. CONCLUSION: Intrahepatic progression was associated with a poorer survival outcome compared with extrahepatic progression in advanced HCC. After intrahepatic progression, additional locoregional therapy based on systemic therapy may offer clinical benefits on OS and PFS in second-line treatment, the benefits were limited to patients who had once achieved tumor control during their first-line treatments.


Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , Humanos , Carcinoma Hepatocelular/tratamento farmacológico , Neoplasias Hepáticas/tratamento farmacológico , Resultado do Tratamento , Estudos Retrospectivos , Intervalo Livre de Progressão
19.
Adv Mater ; 36(3): e2306736, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37853568

RESUMO

Immune cells are pivotal in cancer immunotherapy, yet their therapeutic effectiveness is often hampered by limited tumor infiltration and inhibitory tumor microenvironments. An alkaline phosphatase (ALP)-responsive and transformable supramolecular bis-specific cell engager (Supra-BiCE) to harness natural killer (NK)/T cells for effective cancer immunotherapy is introduced here. The Supra-BiCE, consisting of both SA-P (a phosphorylated peptide targeting and blocking programmed cell death ligand 1 (PD-L1)) and SA-T (a phosphorylated peptide targeting and blocking T cell immunoglobulin and ITIM domain (TIGIT)) is constructed by a simple co-assembling strategy. Upon intravenous administration, Supra-BiCE self-assembles into nanoribbons and interacts with NK/T cells via TIGIT. Notably, these nanoribbons undergo transformation into long nanofibrils within ALP-overexpressing tumor regions, resulting in enhanced binding affinities of Supra-BiCE to both PD-L1 and TIGIT. Consequently, this leads to the accumulation and retention of NK/T cells within tumor regions. Furthermore, the combinatorial blockade of checkpoints by Supra-BiCE activates infiltrating NK/T cells. Moreover, the adjustable peptide ratio in Supra-BiCE enables customization for optimal therapeutic effects against distinct tumor types. Particularly, Supra-BiCE (T:P = 1:3) achieved 98.27% tumor suppression rate against colon carcinoma model. Overall, this study offers a promising tool for engaging NK and T cells for cancer immunotherapy.


Assuntos
Neoplasias do Colo , Nanotubos de Carbono , Neoplasias , Humanos , Linfócitos T/metabolismo , Células Matadoras Naturais , Antígeno B7-H1 , Imunoterapia/métodos , Receptores Imunológicos/metabolismo , Peptídeos/farmacologia , Microambiente Tumoral
20.
Neurology ; 102(9): e209299, 2024 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-38598742

RESUMO

BACKGROUND AND OBJECTIVES: Stroke attributable to nonoptimal temperature needs more attention with dramatic climate change. The aim of this study was to estimate the global burden and distribution characteristics of the burden. METHODS: In this ecological study, we collected data from the Climate Research Unit Gridded Time Series, the World Bank databases, and the Global Burden of Diseases study to estimate the distribution of burden. We used the joinpoint model, decomposition analysis, age-period-cohort model, panel data analysis, and health inequality analysis to assess the different types of stroke burden attributable to different climatic conditions. RESULTS: The burden of stroke attributable to nonoptimal temperature continued to grow, and aging was a key factor in this increase. In 2019, 521,031 (95% uncertainty interval [UI] 402,433-663,996) deaths and 9,423,649 (95% UI 7,207,660-12,055,172) disability-adjusted life years [DALYs] attributable to stroke due to nonoptimal temperature were recorded globally. Globally, men (age-standardized mortality rate [ASMR] 7.70, 95% UI 5.80-9.73; age-standardized DALY rate [ASDR] 139.69, 95% UI 102.96-178.54 in 2019) had a heavier burden than women (ASMR 5.89, 95% UI 4.50-7.60; ASDR 96.02, 95% UI 72.62-123.85 in 2019). Central Asia (ASMR 18.12, 95% UI 13.40-24.53; ASDR 327.35, 95% UI 240.24-440.61 in 2019) had the heaviest burden at the regional level. In the national level, North Macedonia (ASMR 32.97, 95% UI 20.57-47.44 in 2019) and Mongolia (ASDR 568.54, 95% UI 242.03-1,031.14 in 2019) had the highest ASMR/ASDR, respectively. Low temperature currently contributes to the main burden (deaths 474,002, 95% UI 355,077-606,537; DALYs 8,357,198, 95% UI 6,186,217-10,801,911 attributable to low temperature vs deaths 48,030, 95% UI 5,630-104,370; DALYs 1,089,329, 95% UI 112,690-2,375,345 attributable to high temperature in 2019). However, the burden due to high temperature has increased rapidly, especially among people aged older than 10 years, and was disproportionately concentrated in low sociodemographic index (SDI) regions such as Africa. In addition, the rapid increase in the stroke burden due to high temperature in Central Asia also requires special attention. DISCUSSION: This is the first study to assess the global stroke burden attributed to nonoptimal temperature. The dramatic increase in the burden due to high temperature requires special attention, especially in low-SDI countries.


Assuntos
Carga Global da Doença , Acidente Vascular Cerebral , Masculino , Humanos , Feminino , Idoso , Temperatura , Disparidades nos Níveis de Saúde , Anos de Vida Ajustados por Qualidade de Vida , Saúde Global , Acidente Vascular Cerebral/epidemiologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA