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1.
Cell ; 153(1): 101-11, 2013 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-23540693

RESUMO

LINE-1 (L1) retrotransposons are mobile genetic elements comprising ~17% of the human genome. New L1 insertions can profoundly alter gene function and cause disease, though their significance in cancer remains unclear. Here, we applied enhanced retrotransposon capture sequencing (RC-seq) to 19 hepatocellular carcinoma (HCC) genomes and elucidated two archetypal L1-mediated mechanisms enabling tumorigenesis. In the first example, 4/19 (21.1%) donors presented germline retrotransposition events in the tumor suppressor mutated in colorectal cancers (MCC). MCC expression was ablated in each case, enabling oncogenic ß-catenin/Wnt signaling. In the second example, suppression of tumorigenicity 18 (ST18) was activated by a tumor-specific L1 insertion. Experimental assays confirmed that the L1 interrupted a negative feedback loop by blocking ST18 repression of its enhancer. ST18 was also frequently amplified in HCC nodules from Mdr2(-/-) mice, supporting its assignment as a candidate liver oncogene. These proof-of-principle results substantiate L1-mediated retrotransposition as an important etiological factor in HCC.


Assuntos
Carcinoma Hepatocelular/genética , Análise Mutacional de DNA , Genes Supressores de Tumor , Neoplasias Hepáticas/genética , Elementos Nucleotídeos Longos e Dispersos , Mutagênese Insercional , Subfamília B de Transportador de Cassetes de Ligação de ATP/genética , Adulto , Idoso , Animais , Linhagem Celular Tumoral , Transformação Celular Neoplásica , Feminino , Humanos , Masculino , Camundongos , Pessoa de Meia-Idade , Proteínas Repressoras/genética , Proteínas Supressoras de Tumor/genética , Membro 4 da Subfamília B de Transportadores de Cassetes de Ligação de ATP
2.
Plant Cell ; 36(7): 2465-2490, 2024 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-38513609

RESUMO

Plants in habitats with unpredictable conditions often have diversified bet-hedging strategies that ensure fitness over a wider range of variable environmental factors. A striking example is the diaspore (seed and fruit) heteromorphism that evolved to maximize species survival in Aethionema arabicum (Brassicaceae) in which external and endogenous triggers allow the production of two distinct diaspores on the same plant. Using this dimorphic diaspore model, we identified contrasting molecular, biophysical, and ecophysiological mechanisms in the germination responses to different temperatures of the mucilaginous seeds (M+ seed morphs), the dispersed indehiscent fruits (IND fruit morphs), and the bare non-mucilaginous M- seeds obtained by pericarp (fruit coat) removal from IND fruits. Large-scale comparative transcriptome and hormone analyses of M+ seeds, IND fruits, and M- seeds provided comprehensive datasets for their distinct thermal responses. Morph-specific differences in co-expressed gene modules in seeds, as well as in seed and pericarp hormone contents, identified a role of the IND pericarp in imposing coat dormancy by generating hypoxia affecting abscisic acid (ABA) sensitivity. This involved expression of morph-specific transcription factors, hypoxia response, and cell wall remodeling genes, as well as altered ABA metabolism, transport, and signaling. Parental temperature affected ABA contents and ABA-related gene expression and altered IND pericarp biomechanical properties. Elucidating the molecular framework underlying the diaspore heteromorphism can provide insight into developmental responses to globally changing temperatures.


Assuntos
Brassicaceae , Frutas , Regulação da Expressão Gênica de Plantas , Germinação , Sementes , Temperatura , Germinação/genética , Germinação/fisiologia , Sementes/genética , Sementes/fisiologia , Sementes/crescimento & desenvolvimento , Sementes/metabolismo , Brassicaceae/genética , Brassicaceae/fisiologia , Brassicaceae/metabolismo , Frutas/genética , Frutas/fisiologia , Frutas/crescimento & desenvolvimento , Frutas/metabolismo , Reguladores de Crescimento de Plantas/metabolismo , Transcriptoma/genética , Dormência de Plantas/genética , Dormência de Plantas/fisiologia , Ácido Abscísico/metabolismo
3.
Plant Cell ; 2024 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-38691576

RESUMO

Soil salinity is a major contributor to crop yield losses. To improve our understanding of root responses to salinity, we developed and exploited a real-time salt-induced tilting assay. This assay follows root growth upon both gravitropic and salt challenges, revealing that root bending upon tilting is modulated by Na+ ions, but not by osmotic stress. Next, we measured this salt-specific response in 345 natural Arabidopsis (Arabidopsis thaliana) accessions and discovered a genetic locus, encoding the cell wall-modifying enzyme EXTENSIN ARABINOSE DEFICIENT TRANSFERASE (ExAD) that is associated with root bending in the presence of NaCl (hereafter salt). Extensins are a class of structural cell wall glycoproteins known as hydroxyproline (Hyp)-rich glycoproteins, which are posttranslationally modified by O-glycosylation, mostly involving Hyp-arabinosylation. We show that salt-induced ExAD-dependent Hyp-arabinosylation influences root bending responses and cell wall thickness. Roots of exad1 mutant seedlings, which lack Hyp-arabinosylation of extensin, displayed increased thickness of root epidermal cell walls and greater cell wall porosity. They also showed altered gravitropic root bending in salt conditions and a reduced salt-avoidance response. Our results suggest that extensin modification via Hyp-arabinosylation is a unique salt-specific cellular process required for the directional response of roots exposed to salinity.

4.
PLoS Pathog ; 20(2): e1012032, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38394332

RESUMO

Lyme disease (LD) caused by Borrelia burgdorferi is among the most important human vector borne diseases for which there is no effective prevention method. Identification of tick saliva transmission factors of the LD agent is needed before the highly advocated tick antigen-based vaccine could be developed. We previously reported the highly conserved Ixodes scapularis (Ixs) tick saliva serpin (S) 17 (IxsS17) was highly secreted by B. burgdorferi infected nymphs. Here, we show that IxsS17 promote tick feeding and enhances B. burgdorferi colonization of the host. We show that IxsS17 is not part of a redundant system, and its functional domain reactive center loop (RCL) is 100% conserved in all tick species. Yeast expressed recombinant (r) IxsS17 inhibits effector proteases of inflammation, blood clotting, and complement innate immune systems. Interestingly, differential precipitation analysis revealed novel functional insights that IxsS17 interacts with both effector proteases and regulatory protease inhibitors. For instance, rIxsS17 interacted with blood clotting proteases, fXII, fX, fXII, plasmin, and plasma kallikrein alongside blood clotting regulatory serpins (antithrombin III and heparin cofactor II). Similarly, rIxsS17 interacted with both complement system serine proteases, C1s, C2, and factor I and the regulatory serpin, plasma protease C1 inhibitor. Consistently, we validated that rIxsS17 dose dependently blocked deposition of the complement membrane attack complex via the lectin complement pathway and protected complement sensitive B. burgdorferi from complement-mediated killing. Likewise, co-inoculating C3H/HeN mice with rIxsS17 and B. burgdorferi significantly enhanced colonization of mouse heart and skin organs in a reverse dose dependent manner. Taken together, our data suggests an important role for IxsS17 in tick feeding and B. burgdorferi colonization of the host.


Assuntos
Borrelia burgdorferi , Ixodes , Doença de Lyme , Serpinas , Camundongos , Animais , Humanos , Serpinas/metabolismo , Saliva/metabolismo , Peptídeo Hidrolases , Camundongos Endogâmicos C3H , Proteínas do Sistema Complemento , Endopeptidases , Sistema Imunitário/metabolismo
5.
Annu Rev Microbiol ; 75: 719-739, 2021 10 08.
Artigo em Inglês | MEDLINE | ID: mdl-34375543

RESUMO

Heat shock protein 90 (Hsp90) is a molecular chaperone that folds and remodels proteins, thereby regulating the activity of numerous substrate proteins. Hsp90 is widely conserved across species and is essential in all eukaryotes and in some bacteria under stress conditions. To facilitate protein remodeling, bacterial Hsp90 collaborates with the Hsp70 molecular chaperone and its cochaperones. In contrast, the mechanism of protein remodeling performed by eukaryotic Hsp90 is more complex, involving more than 20 Hsp90 cochaperones in addition to Hsp70 and its cochaperones. In this review, we focus on recent progress toward understanding the basic mechanisms of bacterial Hsp90-mediated protein remodeling and the collaboration between Hsp90 and Hsp70. We describe the universally conserved structure and conformational dynamics of these chaperones and their interactions with one another and with client proteins. The physiological roles of Hsp90 in Escherichia coli and other bacteria are also discussed. We anticipate that the information gained from exploring the mechanism of the bacterial chaperone system will provide a framework for understanding the more complex eukaryotic Hsp90 system.


Assuntos
Proteínas de Bactérias , Proteínas de Choque Térmico HSP90 , Proteínas de Bactérias/química , Proteínas de Bactérias/metabolismo , Escherichia coli/metabolismo , Proteínas de Escherichia coli/química , Proteínas de Escherichia coli/metabolismo , Proteínas de Choque Térmico HSP70/química , Proteínas de Choque Térmico HSP70/metabolismo , Proteínas de Choque Térmico HSP90/química , Proteínas de Choque Térmico HSP90/metabolismo , Chaperonas Moleculares/química , Chaperonas Moleculares/metabolismo , Ligação Proteica
6.
J Infect Dis ; 2024 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-38169323

RESUMO

BACKGROUND: Tuberculous meningitis (TBM) is difficult to diagnose. We investigated whether a 3-gene host response signature in blood can distinguish TBM from other brain infections. METHODS: The expression of 3 genes (Dual specificity phosphatase 3- DUSP3, Guanylate-binding protein- GBP5, Krupple-like factor 2- KLF2) was analysed by RNA sequencing of archived whole blood from four cohorts of Vietnamese adults: 281 with TBM; 279 with pulmonary tuberculosis; 50 with other brain infections; and 30 healthy controls. 'TB scores' (combined 3-gene expression) were calculated following published methodology and discriminatory performance compared using area under a receiver operator characteristic curve (AUC). RESULTS: GBP5 was upregulated in TBM compared to other brain infections (p < 0.001), with no difference in DUSP3 and KLF2 expression. The diagnostic performance of GBP5 alone (AUC 0.74 (95% CI 0.67-0.81)) was slightly better than the 3-gene TB score (AUC 0.66, 95% CI 0.58-0.73) in TBM. Both GBP5 expression and TB score were higher in HIV-positive participants (P < 0.001), with good diagnostic performance of GBP5 alone (AUC 0.86, 95% CI 0.80-0.93). CONCLUSION: The 3-gene host signature in whole blood has the ability to discriminate TBM from other brain infections, including in HIV-positive individuals. Validation in large prospective diagnostic study is now required.

7.
Biophys J ; 2024 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-38751115

RESUMO

The precise prediction of major histocompatibility complex (MHC)-peptide complex structures is pivotal for understanding cellular immune responses and advancing vaccine design. In this study, we enhanced AlphaFold's capabilities by fine-tuning it with a specialized dataset consisting of exclusively high-resolution class I MHC-peptide crystal structures. This tailored approach aimed to address the generalist nature of AlphaFold's original training, which, while broad-ranging, lacked the granularity necessary for the high-precision demands of class I MHC-peptide interaction prediction. A comparative analysis was conducted against the homology-modeling-based method Pandora as well as the AlphaFold multimer model. Our results demonstrate that our fine-tuned model outperforms others in terms of root-mean-square deviation (median value for Cα atoms for peptides is 0.66 Å) and also provides enhanced predicted local distance difference test scores, offering a more reliable assessment of the predicted structures. These advances have substantial implications for computational immunology, potentially accelerating the development of novel therapeutics and vaccines by providing a more precise computational lens through which to view MHC-peptide interactions.

8.
J Proteome Res ; 23(1): 84-94, 2024 01 05.
Artigo em Inglês | MEDLINE | ID: mdl-37999680

RESUMO

Niemann-Pick disease, type C (NPC) is a neurodegenerative, lysosomal storage disorder in individuals carrying two mutated copies of either the NPC1 or NPC2 gene. Consequently, impaired cholesterol recycling and an array of downstream events occur. Interestingly, in NPC, the hippocampus displays lysosomal lipid storage but does not succumb to progressive neurodegeneration as significantly as other brain regions. Since defining the neurodegeneration mechanisms in this disease is still an active area of research, we use mass spectrometry to analyze the overall proteome and phosphorylation pattern changes in the hippocampal region of a murine model of NPC. Using 3 week old mice representing an early disease time point, we observed changes in the expression of 47 proteins, many of which are consistent with the previous literature. New to this study, changes in members of the SNARE complex, including STX7, VTI1B, and VAMP7, were identified. Furthermore, we identified that phosphorylation of T286 on CaMKIIα and S1303 on NR2B increased in mutant animals, even at the late stage of the disease. These phosphosites are crucial to learning and memory and can trigger neuronal death by altering protein-protein interactions.


Assuntos
Doença de Niemann-Pick Tipo C , Proteoma , Animais , Camundongos , Proteoma/genética , Proteoma/metabolismo , Modelos Animais de Doenças , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Doença de Niemann-Pick Tipo C/genética , Hipocampo/metabolismo
9.
J Proteome Res ; 2024 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-38686625

RESUMO

NPC intracellular cholesterol transporter 1 (NPC1) is a multipass, transmembrane glycoprotein mostly recognized for its key role in facilitating cholesterol efflux. Mutations in the NPC1 gene result in Niemann-Pick disease, type C (NPC), a fatal, lysosomal storage disease. Due to the progressively expanding implications of NPC1-related disorders, we investigated endogenous NPC1 protein-protein interactions in the mouse cortex and human-derived iPSCs neuronal models of the disease through coimmunoprecipitation-coupled with LC-MS based proteomics. The current study investigated protein-protein interactions specific to the wild-type and the most prevalent NPC1 mutation (NPC1I1061T) while filtering out any protein interactor identified in the Npc1-/- mouse model. Additionally, the results were matched across the two species to map the parallel interactome of wild-type and mutant NPC1I1061T. Most of the identified wild-type NPC1 interactors were related to cytoskeleton organization, synaptic vesicle activity, and translation. We found many putative NPC1 interactors not previously reported, including two SCAR/WAVE complex proteins that regulate ARP 2/3 complex actin nucleation and multiple membrane proteins important for neuronal activity at synapse. Moreover, we identified proteins important in trafficking specific to wild-type and mutant NPC1I1061T. Together, the findings are essential for a comprehensive understanding of NPC1 biological functions in addition to its classical role in sterol efflux.

10.
Plant J ; 116(3): 921-941, 2023 11.
Artigo em Inglês | MEDLINE | ID: mdl-37609706

RESUMO

Schrenkiella parvula, a leading extremophyte model in Brassicaceae, can grow and complete its lifecycle under multiple environmental stresses, including high salinity. Yet, the key physiological and structural traits underlying its stress-adapted lifestyle are unknown along with trade-offs when surviving salt stress at the expense of growth and reproduction. We aimed to identify the influential adaptive trait responses that lead to stress-resilient and uncompromised growth across developmental stages when treated with salt at levels known to inhibit growth in Arabidopsis and most crops. Its resilient growth was promoted by traits that synergistically allowed primary root growth in seedlings, the expansion of xylem vessels across the root-shoot continuum, and a high capacity to maintain tissue water levels by developing thicker succulent leaves while enabling photosynthesis during salt stress. A successful transition from vegetative to reproductive phase was initiated by salt-induced early flowering, resulting in viable seeds. Self-fertilization in salt-induced early flowering was dependent upon filament elongation in flowers otherwise aborted in the absence of salt during comparable plant ages. The maintenance of leaf water status promoting growth, and early flowering to ensure reproductive success in a changing environment, were among the most influential traits that contributed to the extremophytic lifestyle of S. parvula.


Assuntos
Arabidopsis , Brassicaceae , Brassicaceae/fisiologia , Arabidopsis/fisiologia , Flores , Estresse Salino , Estresse Fisiológico , Água
11.
Epidemiology ; 35(1): 51-59, 2024 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-37756290

RESUMO

BACKGROUND: Research has demonstrated the negative impact of racism on health, yet the measurement of racial sentiment remains challenging. This article provides practical guidance on using social media data for measuring public sentiment. METHODS: We describe the main steps of such research, including data collection, data cleaning, binary sentiment analysis, and visualization of findings. We randomly sampled 55,844,310 publicly available tweets from 1 January 2011 to 31 December 2021 using Twitter's Application Programming Interface. We restricted analyses to US tweets in English using one or more 90 race-related keywords. We used a Support Vector Machine, a supervised machine learning model, for sentiment analysis. RESULTS: The proportion of tweets referencing racially minoritized groups that were negative increased at the county, state, and national levels, with a 16.5% increase at the national level from 2011 to 2021. Tweets referencing Black and Middle Eastern people consistently had the highest proportion of negative sentiment compared with all other groups. Stratifying temporal trends by racial and ethnic groups revealed unique patterns reflecting historical events specific to each group, such as the killing of George Floyd regarding sentiment of posts referencing Black people, discussions of the border crisis near the 2018 midterm elections and anti-Latinx sentiment, and the emergence of COVID-19 and anti-Asian sentiment. CONCLUSIONS: This study demonstrates the utility of social media data as a quantitative means to measure racial sentiment over time and place. This approach can be extended to a range of public health topics to investigate how changes in social and cultural norms impact behaviors and policy.A supplemental digital video is available at http://links.lww.com/EDE/C91.


Assuntos
COVID-19 , Mídias Sociais , Humanos , Estados Unidos , COVID-19/epidemiologia , Grupos Raciais , Saúde Pública , Etnicidade , Atitude
12.
Arch Microbiol ; 206(3): 97, 2024 Feb 13.
Artigo em Inglês | MEDLINE | ID: mdl-38349544

RESUMO

Cordyceps militaris is a well-known medicinal mushroom in Asian countries. This edible fungus has been widely exploited for traditional medicine and functional food production. C. militaris is a heterothallic fungus that requires both the mating-type loci, MAT1-1 and MAT1-2, for fruiting body formation. However, recent studies also indicated two groups of C. militaris, including monokaryotic strains carrying only MAT1-1 in their genomes and heterokaryotic strains harboring both MAT1-1 and MAT1-2. These strain groups are able to produce fruiting bodies under suitable cultivating conditions. In previous work, we showed that monokaryotic strains are more stable than heterokaryotic strains in fruiting body formation through successive culturing generations. In this study, we report a high cordycepin-producing monokaryotic C. militaris strain (HL8) collected in Vietnam. This strain could form normal fruiting bodies with high biological efficiency and contain a cordycepin content of 14.43 mg/g lyophilized fruiting body biomass. The ethanol extraction of the HL8 fruiting bodies resulted in a crude extract with a cordycepin content of 69.15 mg/g. Assays of cytotoxic activity on six human cancer cell lines showed that the extract inhibited the growth of all these cell lines with the IC50 values of 6.41-11.51 µg/mL. Notably, the extract significantly reduced cell proliferation and promoted apoptosis of breast cancer cells. Furthermore, the extract also exhibited strong antifungal activity against Malassezia skin yeasts and the citrus postharvest pathogen Penicillium digitatum. Our work provides a promising monokaryotic C. militaris strain as a bioresource for medicine, cosmetics, and fruit preservation.


Assuntos
Antineoplásicos , Cordyceps , Neoplasias , Penicillium , Humanos , Penicillium/genética , Carpóforos
13.
AIDS Behav ; 2024 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-38992226

RESUMO

Women living with HIV/AIDS (WLHA) encounter numerous challenges, such as stigma and gender disparities, that hinder their access to care, especially in patriarchal societies like Vietnam. We developed a hybrid intervention with online and offline (in-person) components to empower WLHA in Vietnam. The intervention was pilot tested with 91 WLHA in Hanoi. During baseline and 4-month, study investigators delivered two in-person sessions, one Zoom session, and 15 weeks of Zalo (social media platform) discussions to enhance positive coping strategies, treatment utilization and adherence, and engagement of support from family and peers. The participants continued their Zalo discussions from 4-month to 6-month without investigators' involvement. Intervention outcomes, including active coping and perceived barriers to care, were evaluated at baseline, 4-, and 6-month surveys. Mixed-effects regression models showed that the participants' active coping significantly increased from baseline (50.5 ± 9.4) to 4-month (53.8 ± 6.2; p = 0.0001), although there was a slight decrease at 6-month (52.8 ± 7.2), the change from 4-month to 6-month was not significantly significant (p = 0.3256). There was a significant reduction in participants' perceived barriers to care, from 19.8 ± 5.2 at baseline to 17.4 ± 5.2 at 4-month (p < 0.0001), which remained stable at 17.8 ± 4.3 at 6-month (p < 0.0001 compared to baseline). This intervention presents a promising model to empower WLHA in Vietnam and potentially in similar global contexts. Future interventions could benefit from leveraging natural peer leaders and adopting a more person-centered approach to meet WLHA's varying needs.

14.
Pediatr Blood Cancer ; 71(2): e30785, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38018337

RESUMO

BACKGROUND: There remains limited knowledge about the immune response to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccination in pediatric oncology patients, which is essential to provide counseling and risk adaptation in this vulnerable population. The goal of this study was to understand immunogenicity after vaccination in pediatric oncology patients, and determine if certain clinical factors impacted response. METHODS: Patients 0-25 years of age with a diagnosis of cancer and actively receiving therapy were enrolled on study. We excluded patients who were completely vaccinated prior to their cancer diagnosis. Blood samples were collected pre-vaccination, as well as 2, 4-6, and 8-12 weeks after vaccination. Healthy children who were fully vaccinated enrolled as controls. Clinical data and complete blood counts around time of vaccination were collected. To study B- and T-cell immunity, we measured neutralizing antibodies by enzyme-linked immunoassay and interferon gamma secretion by enzyme-linked immunospot, respectively. RESULTS: Twenty-six patients enrolled on study, for which 11 were evaluable oncology patients and seven were healthy controls. Adequate B-cell response was seen in 36.4% of patients, and adequate T-cell response in 77.8% of patients. Numbers were too small to detect differences based on malignancy type. There was no differences in immunity based on absolute lymphocyte count (ALC) or intensity of therapy. CONCLUSION: Pediatric oncology patients have a suboptimal immune response to SARS-CoV-2 vaccination. Booster doses will be imperative to provide optimal protection against COVID-19; however, blood counts may not be a useful guide to optimize the time of administration.


Assuntos
COVID-19 , Neoplasias , Criança , Humanos , Vacinas contra COVID-19 , SARS-CoV-2 , COVID-19/prevenção & controle , Oncologia , Anticorpos Neutralizantes , Neoplasias/terapia , Vacinação , Anticorpos Antivirais
15.
J Chem Inf Model ; 64(3): 960-973, 2024 Feb 12.
Artigo em Inglês | MEDLINE | ID: mdl-38253327

RESUMO

The neural network-based program AlphaFold2 (AF2) provides high accuracy structure prediction for a large fraction of globular proteins. An important question is whether these models are accurate enough for reliably docking small ligands. Several recent papers and the results of CASP15 reveal that local conformational errors reduce the success rates of direct ligand docking. Here, we focus on the ability of the models to conserve the location of binding hot spots, regions on the protein surface that significantly contribute to the binding free energy of the protein-ligand interaction. Clusters of hot spots predict the location and even the druggability of binding sites, and hence are important for computational drug discovery. The hot spots are determined by protein mapping that is based on the distribution of small fragment-sized probes on the protein surface and is less sensitive to local conformation than docking. Mapping models taken from the AlphaFold Protein Structure Database show that identifying binding sites is more reliable than docking, but the success rates are still 5% to 10% lower than based on mapping X-ray structures. The drop in accuracy is particularly large for models of multidomain proteins. However, both the model binding sites and the mapping results can be substantially improved by generating AF2 models for the ligand binding domains of interest rather than the entire proteins and even more if using forced sampling with multiple initial seeds. The mapping of such models tends to reach the accuracy of results obtained by mapping the X-ray structures.


Assuntos
Furilfuramida , Proteínas de Membrana , Ligantes , Ligação Proteica , Conformação Proteica , Sítios de Ligação
16.
Nanotechnology ; 35(34)2024 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-38806017

RESUMO

In this study, magnetic material based on graphene oxide (GO) was developed for enhanced adsorption capacity for heavy metals. The Fe3O4nanoparticles were combined with the GO material using a chitosan (CS) binder to obtain the CS-Fe3O4/GO nanocomposite. The adsorption capacity of this nanocomposite was evaluated by removing heavy metals including Ni2+ions. When GO was composed with Fe3O4and CS, the GO films were densely covered with ferromagnetic particles, which were bound and densely distributed on the GO film surface due to the interaction between GO and CS. The optimal conditions for the complexation of Ni2+and 4-(2-pyridyl azo)-rezoxine (PAR) are 1 ml Ni2+, 2 ml PAR 100 mg l-1,pH= 6 (adjusted with 0.7 ml of the 0.1 M K2HPO4solution) and a complexation time of 20 min. After 50 min of adsorption, the Ni2+removal efficiency of the CS-Fe3O4/GO nanocomposite reached 81.21% and the corresponding adsorption capacity was 2.03 mg g-1. The Ni2+removal process followed the first-order model and Freundlich isotherm. This process was spontaneous (ΔGo< 0) and an exothermic process (ΔHo= -1128.875 J·mol-1). In addition, the factors affecting this process were investigated, including thepHsolution, the dosage of the CS-Fe3O4/GO nanocomposite and the initial Ni2+concentration. The CS-Fe3O4/GO nanocomposite showed a potential adsorption capacity in removing Ni2+at low concentrations from wastewater.

17.
Cereb Cortex ; 33(22): 11157-11169, 2023 11 04.
Artigo em Inglês | MEDLINE | ID: mdl-37757479

RESUMO

Precision walking (PW) incorporates precise step adjustments into regular walking patterns to navigate challenging surroundings. However, the brain processes involved in PW control, which encompass cortical regions and interregional interactions, are not fully understood. This study aimed to investigate the changes in regional activity and effective connectivity within the frontoparietal network associated with PW. Functional near-infrared spectroscopy data were recorded from adult subjects during treadmill walking tasks, including normal walking (NOR) and PW with visual cues, wherein the intercue distance was either fixed (FIX) or randomly varied (VAR) across steps. The superior parietal lobule (SPL), dorsal premotor area (PMd), supplementary motor area (SMA), and dorsolateral prefrontal cortex (dlPFC) were specifically targeted. The results revealed higher activities in SMA and left PMd, as well as left-to-right SPL connectivity, in VAR than in FIX. Activities in SMA and right dlPFC, along with dlPFC-to-SPL connectivity, were higher in VAR than in NOR. Overall, these findings provide insights into the roles of different brain regions and connectivity patterns within the frontoparietal network in facilitating gait control during PW, providing a useful baseline for further investigations into brain networks involved in locomotion.


Assuntos
Mapeamento Encefálico , Sinais (Psicologia) , Adulto , Humanos , Caminhada , Encéfalo , Espectroscopia de Luz Próxima ao Infravermelho
18.
Environ Res ; 258: 119418, 2024 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-38897434

RESUMO

Highly colored azo dye-contaminated wastewater poses significant environmental threats and requires effective treatment before discharge. The anaerobic azo dye treatment method is a cost-effective and environmentally friendly solution, while its time-consuming and inefficient processes present substantial challenges for industrial scaling. Thus, the use of iron materials presents a promising alternative. Laboratory studies have demonstrated that systems coupled with iron materials enhance the decolorization efficiency and reduce the processing time. To fully realize the potential of iron materials for anaerobic azo dye treatment, a comprehensive synthesis and evaluation based on individual-related research studies, which have not been conducted to date, are necessary. This review provides, for the first time, an extensive and detailed overview of the utilization of iron materials for azo dye treatment, with a focus on decolorization. It assesses the treatment potential, analyzes the influencing factors and their impacts, and proposes metabolic pathways to enhance anaerobic dye treatment using iron materials. The physicochemical characteristics of iron materials are also discussed to elucidate the mechanisms behind the enhanced bioreduction of azo dyes. This study further addresses the current obstacles and outlines future prospects for industrial-scale application of iron-coupled treatment systems.

19.
Mol Divers ; 2024 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-38886315

RESUMO

This study aimed to use a computational approach that combined the classification-based QSAR model, molecular docking, ADME studies, and molecular dynamics (MD) to identify potential inhibitors of Fyn kinase. First, a robust classification model was developed from a dataset of 1,078 compounds with known Fyn kinase inhibitory activity, using the XGBoost algorithm. After that, molecular docking was performed between potential compounds identified from the QSAR model and Fyn kinase to assess their binding strengths and key interactions, followed by MD simulations. ADME studies were additionally conducted to preliminarily evaluate the pharmacokinetics and drug-like characteristics of these compounds. The results showed that our obtained model exhibited good predictive performance with an accuracy of 0.95 on the test set, affirming its reliability in identifying potent Fyn kinase inhibitors. Through the application of this model in conjunction with molecular docking and ADME studies, nine compounds were identified as potential Fyn kinase inhibitors, including 208 (ZINC70708110), 728 (ZINC8792432), 734 (ZINC8792187), 736 (ZINC8792350), 738 (ZINC8792286), 739 (ZINC8792309), 817 (ZINC33901069), 852 (ZINC20759145), and 1227 (ZINC100006936). MD simulations further demonstrated that the four most promising compounds, 728, 734, 736, and 852 exhibited stable binding with Fyn kinase during the simulation process. Additionally, a web-based platform ( https://fynkinase.streamlit.app/ ) has been developed to streamline the screening process. This platform enables users to predict the activity of their substances of interest on Fyn kinase from their SMILES, using our classification-based QSAR model and molecular docking.

20.
Mol Divers ; 2024 Apr 06.
Artigo em Inglês | MEDLINE | ID: mdl-38582821

RESUMO

This study aims to identify potential focal adhesion kinase (FAK) inhibitors through an integrated computational approach, combining mol2vec descriptor-based QSAR, molecular docking, ADMET study, and molecular dynamics simulation. A dataset of 437 compounds with known FAK inhibitory activities was used to develop QSAR models using machine learning algorithms combined with mol2vec descriptors. Subsequently, the most promising compounds were subjected to molecular docking against FAK to evaluate their binding affinities and key interactions. ADMET study and molecular dynamics simulation were also employed to investigate the pharmacokinetic, drug-like properties, and the stability of the protein-ligand complexes. The results showed that the mol2vec descriptor-based QSAR model established by support vector regression demonstrated good predictive performance (R2 = 0.813, RMSE = 0.453, MAE = 0.263 in case of training set, and R2 = 0.729, RMSE = 0.635, MAE = 0.477 in case of test set), indicating their reliability in identifying potent FAK inhibitors. Using this QSAR model and molecular docking, compound 21 (ZINC000004523722) was identified as the most potential compound, with predicted logIC50 value and binding energy of 2.59 and - 9.3 kcal/mol, respectively. The results of molecular dynamics simulation and ADMET study also further suggested its potential as a promising drug candidate. However, because our research was merely theoretical, additional in vitro and in vivo studies are required for the verification of these results.

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