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1.
Nat Chem Biol ; 20(3): 373-381, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-37919548

RESUMO

The RAS-mitogen-activated protein kinase (MAPK) pathway includes KSR, RAF, MEK and the phospho-regulatory sensor 14-3-3. Specific assemblies among these components drive various diseases and likely dictate efficacy for numerous targeted therapies, including allosteric MEK inhibitors (MEKi). However, directly measuring drug interactions on physiological RAS-MAPK complexes in live cells has been inherently challenging to query and therefore remains poorly understood. Here we present a series of NanoBRET-based assays to quantify direct target engagement of MEKi on MEK1 and higher-order MEK1-bound complexes with ARAF, BRAF, CRAF, KSR1 and KSR2 in the presence and absence of 14-3-3 in living cells. We find distinct MEKi preferences among these complexes that can be compiled to generate inhibitor binding profiles. Further, these assays can report on the influence of the pathogenic BRAF-V600E mutant on MEKi binding. Taken together, these approaches can be used as a platform to screen for compounds intended to target specific complexes in the RAS-MAPK cascade.


Assuntos
Bioensaio , Proteínas Proto-Oncogênicas B-raf , Proteínas Proto-Oncogênicas B-raf/genética , Sistema de Sinalização das MAP Quinases , Inibidores de Proteínas Quinases/farmacologia
2.
PLoS Biol ; 20(11): e3001855, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-36395330

RESUMO

The neuronal microtubule cytoskeleton is key to establish axon-dendrite polarity. Dendrites are characterized by the presence of minus-end out microtubules. However, the mechanisms that organize these microtubules with the correct orientation are still poorly understood. Using Caenorhabditis elegans as a model system for microtubule organization, we characterized the role of 2 microtubule minus-end related proteins in this process, the microtubule minus-end stabilizing protein calmodulin-regulated spectrin-associated protein (CAMSAP/PTRN-1), and the NINEIN homologue, NOCA-2 (noncentrosomal microtubule array). We found that CAMSAP and NINEIN function in parallel to mediate microtubule organization in dendrites. During dendrite outgrowth, RAB-11-positive vesicles localized to the dendrite tip to nucleate microtubules and function as a microtubule organizing center (MTOC). In the absence of either CAMSAP or NINEIN, we observed a low penetrance MTOC vesicles mislocalization to the cell body, and a nearly fully penetrant phenotype in double mutant animals. This suggests that both proteins are important for localizing the MTOC vesicles to the growing dendrite tip to organize microtubules minus-end out. Whereas NINEIN localizes to the MTOC vesicles where it is important for the recruitment of the microtubule nucleator γ-tubulin, CAMSAP localizes around the MTOC vesicles and is cotranslocated forward with the MTOC vesicles upon dendritic growth. Together, these results indicate that microtubule nucleation from the MTOC vesicles and microtubule stabilization are both important to localize the MTOC vesicles distally to organize dendritic microtubules minus-end out.


Assuntos
Proteínas de Caenorhabditis elegans , Caenorhabditis elegans , Animais , Microtúbulos , Centro Organizador dos Microtúbulos , Tubulina (Proteína) , Dendritos , Proteínas Associadas aos Microtúbulos , Proteínas de Caenorhabditis elegans/genética
3.
Nucleic Acids Res ; 51(13): 6914-6926, 2023 07 21.
Artigo em Inglês | MEDLINE | ID: mdl-37264902

RESUMO

Prokaryotic Cas1-Cas2 protein complexes generate adaptive immunity to mobile genetic elements (MGEs), by capture and integration of MGE DNA in to CRISPR sites. De novo immunity relies on naive adaptation-Cas1-Cas2 targeting of MGE DNA without the aid of pre-existing immunity 'interference' complexes-by mechanisms that are not clear. Using E. coli we show that the chaperone DnaK inhibits DNA binding and integration by Cas1-Cas2, and inhibits naive adaptation in cells that results from chromosomal self-targeting. Inhibition of naive adaptation was reversed by deleting DnaK from cells, by mutation of the DnaK substrate binding domain, and by expression of an MGE (phage λ) protein. We also imaged fluorescently labelled Cas1 in living cells, observing that Cas1 foci depend on active DNA replication, and are much increased in frequency in cells lacking DnaK. We discuss a model in which DnaK provides a mechanism for restraining naive adaptation from DNA self-targeting, until DnaK is triggered to release Cas1-Cas2 to target MGE DNA.


Assuntos
Proteínas Associadas a CRISPR , Proteínas de Escherichia coli , Proteínas de Choque Térmico HSP70 , Repetições Palindrômicas Curtas Agrupadas e Regularmente Espaçadas , Proteínas Associadas a CRISPR/metabolismo , Sistemas CRISPR-Cas , DNA/química , Escherichia coli/metabolismo , Proteínas de Escherichia coli/metabolismo , Proteínas de Choque Térmico HSP70/metabolismo
4.
Nucleic Acids Res ; 51(4): 1740-1749, 2023 02 28.
Artigo em Inglês | MEDLINE | ID: mdl-36718939

RESUMO

DNA strand breaks are repaired by DNA synthesis from an exposed DNA end paired with a homologous DNA template. DNA polymerase delta (Pol δ) catalyses DNA synthesis in multiple eukaryotic DNA break repair pathways but triggers genome instability unless its activity is restrained. We show that human HelQ halts DNA synthesis by isolated Pol δ and Pol δ-PCNA-RPA holoenzyme. Using novel HelQ mutant proteins we identify that inhibition of Pol δ is independent of DNA binding, and maps to a 70 amino acid intrinsically disordered region of HelQ. Pol δ and its POLD3 subunit robustly stimulated DNA single-strand annealing by HelQ, and POLD3 and HelQ interact physically via the intrinsically disordered HelQ region. This data, and inability of HelQ to inhibit DNA synthesis by the POLD1 catalytic subunit of Pol δ, reveal a mechanism for limiting DNA synthesis and promoting DNA strand annealing during human DNA break repair, which centres on POLD3.


Assuntos
DNA Helicases , DNA Polimerase III , Replicação do DNA , Humanos , DNA/metabolismo , DNA Polimerase III/genética , Primers do DNA , Antígeno Nuclear de Célula em Proliferação/metabolismo , DNA Helicases/química , DNA Helicases/metabolismo
5.
J Am Chem Soc ; 146(14): 9709-9720, 2024 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-38546406

RESUMO

Chemically modifying monolayer two-dimensional transition metal dichalcogenides (TMDs) with organic molecules provides a wide range of possibilities to regulate the electronic and optoelectronic performance of both materials and devices. However, it remains challenging to chemically attach organic molecules to monolayer TMDs without damaging their crystal structures. Herein, we show that the Mo atoms of monolayer MoS2 (1L-MoS2) in defect states can coordinate with both catechol and 1,10-phenanthroline (Phen) groups, affording a facile route to chemically modifying 1L-MoS2. Through the design of two isomeric molecules (LA2 and LA5) comprising catechol and Phen groups, we show that attaching organic molecules to Mo atoms via coordinative bonds has no negative effect on the crystal structure of 1L-MoS2. Both theoretical calculation and experiment results indicate that the coordinative strategy is beneficial for (i) repairing sulfur vacancies and passivating defects; (ii) achieving a long-term and stable n-doping effect; and (iii) facilitating the electron transfer. Field effect transistors (FETs) based on the coordinatively modified 1L-MoS2 show high electron mobilities up to 120.3 cm2 V-1 s-1 with impressive current on/off ratios over 109. Our results indicate that coordinatively attaching catechol- or Phen-bearing molecules may be a general method for the nondestructive modification of TMDs.

6.
Eur J Immunol ; 53(4): e2250204, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-36681386

RESUMO

Tuberculosis caused by Mycobacterium tuberculosis (M.tb) is one of the main causes of human death in the world. Bacillus Calmette-Guérin (BCG) provides limited protection in adolescents and adults. To explore the factors reducing efficacy of BCG vaccine, we assess the impacts of interleukin (IL)-10 and alarmins S100A8/A9 on T-cell memory. We found that BCG-induced IL-10 inhibited production of S100A8/A9 in human peripheral blood mononuclear cells (PBMCs) and murine splenocytes. S100A9 deficiency inhibited IFN-γ production by CD4+ T cells in the early phase of BCG immunization and hindered the development of effector memory T helper type 1 (Th1) cells, while IL-10 deficiency promoted Th1 memory and blocking IL-10 signaling enhanced Th1 protective recall response against M.tb. IL-10 inhibited the binding of transcription factor CCAAT enhancer binding protein beta to S100a8/a9 promoter leading to S100A8/A9 reduction. S100A8/A9 heterodimer enhanced the IFN-γ production via receptor for advanced glycation end products signaling in CD4+ T cells. Our results demonstrate a hurdle to development of Th1 memory after BCG immunization and clarify the mechanism of the regulation of Th1 memory by IL-10 and S100A8/A9.


Assuntos
Mycobacterium bovis , Tuberculose , Adolescente , Adulto , Animais , Humanos , Camundongos , Vacina BCG , Interleucina-10 , Leucócitos Mononucleares , Células Th1/imunologia
7.
J Intern Med ; 295(4): 557-568, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38111091

RESUMO

BACKGROUND: Effects of intensive blood pressure (BP) control on cognitive outcomes in patients with excess orthostatic BP changes are unclear. We aimed to evaluate whether orthostatic BP changes modified the effects of BP intervention on cognitive impairment. METHODS: We analyzed 8547 participants from the Systolic Blood Pressure Intervention Trial Memory and cognition IN Decreased Hypertension. Associations between orthostatic BP changes and incident cognitive outcomes were evaluated by restricted cubic spline curves based on Cox models. The interactions between orthostatic BP changes and intensive BP intervention were assessed. RESULTS: The U-shaped associations were observed between baseline orthostatic systolic BP changes and cognitive outcomes. However, there were insignificant interactions between either change in orthostatic systolic BP (P for interaction = 0.81) or diastolic BP (P for interaction = 0.32) and intensive BP intervention for the composite outcome of probable dementia or mild cognitive impairment (MCI). The hazard ratio of intensive versus standard target for the composite cognitive outcome was 0.82 (95% CI 0.50-1.35) in those with an orthostatic systolic BP reduction of >20 mmHg and 0.41 (95% CI 0.21-0.80) in those with an orthostatic systolic BP increase of >20 mmHg. Results were similar for probable dementia and MCI. The annual changes in global cerebral blood flow (P for interaction = 0.86) consistently favored intensive BP treatment across orthostatic systolic BP changes. CONCLUSION: Intensive BP control did not have a deteriorating effect on cognitive outcomes among hypertensive patients experiencing significant postural BP changes.


Assuntos
Disfunção Cognitiva , Demência , Hipertensão , Hipotensão Ortostática , Humanos , Pressão Sanguínea , Cognição , Hipertensão/tratamento farmacológico , Hipotensão Ortostática/psicologia
8.
Mol Carcinog ; 63(4): 742-756, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38270247

RESUMO

Nuclear factor erythroid 2-related factor 2 (Nrf2) significantly contributes to drug resistance of cancer cells, and Nrf2 inhibitors have been vigorously pursued. Repurposing of existing drugs, especially anticancer drugs, is a straightforward and promising strategy to find clinically available Nrf2 inhibitors and effective drug combinations. Topoisomerase inhibitors SN-38 (an active metabolite of irinotecan), topotecan, mitoxantrone, and epirubicin were found to significantly suppress Nrf2 transcriptional activity in cancer cells. SN-38, the most potent one among them, significantly inhibited the transcription of Nrf2, as indicated by decreased mRNA level and binding of RNA polymerase II to NFE2L2 gene, while no impact on Nrf2 protein or mRNA degradation was observed. SN-38 synergized with Nrf2-sensitive anticancer drugs such as mitomycin C in killing colorectal cancer cells, and irinotecan and mitomycin C synergistically inhibited the growth of SW480 xenografts in nude mice. Our study identified SN-38 and three other topoisomerase inhibitors as Nrf2 inhibitors, revealed the Nrf2-inhibitory mechanism of SN-38, and indicate that clinically feasible drug combinations could be designed based on their interactions with Nrf2 signaling.


Assuntos
Antineoplásicos , Neoplasias Colorretais , Animais , Camundongos , Humanos , Irinotecano/farmacologia , Camptotecina/farmacologia , Mitomicina/farmacologia , Camundongos Nus , Fator 2 Relacionado a NF-E2/genética , Antineoplásicos/farmacologia , Resistencia a Medicamentos Antineoplásicos , Inibidores da Topoisomerase/farmacologia , Combinação de Medicamentos , Neoplasias Colorretais/tratamento farmacológico , Neoplasias Colorretais/genética
9.
J Cardiovasc Electrophysiol ; 35(4): 811-820, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38424601

RESUMO

INTRODUCTION: Various left atrial (LA) anatomical structures are correlated with postablative recurrence for atrial fibrillation (AF) patients. Comprehensively integrating anatomical structures, digitizing them, and implementing in-depth analysis, which may supply new insights, are needed. Thus, we aim to establish an interpretable model to identify AF patients' phenotypes according to LA anatomical morphology, using machine learning techniques. METHODS AND RESULTS: Five hundred and nine AF patients underwent first ablation treatment in three centers were included and were followed-up for postablative recurrent atrial arrhythmias. Data from 369 patients were regarded as training set, while data from another 140 patients, collected from different centers, were used as validation set. We manually measured 57 morphological parameters on enhanced computed tomography with three-dimensional reconstruction technique and implemented unsupervised learning accordingly. Three morphological groups were identified, with distinct prognosis according to Kaplan-Meier estimator (p < .001). Multivariable Cox model revealed that morphological grouping were independent predictors of 1-year recurrence (Group 1: HR = 3.00, 95% CI: 1.51-5.95, p = .002; Group 2: HR = 4.68, 95% CI: 2.40-9.11, p < .001; Group 3 as reference). Furthermore, external validation consistently demonstrated our findings. CONCLUSIONS: Our study illustrated the feasibility of employing unsupervised learning for the classification of LA morphology. By utilizing morphological grouping, we can effectively identify individuals at different risks of postablative recurrence and thereby assist in clinical decision-making.


Assuntos
Apêndice Atrial , Fibrilação Atrial , Ablação por Cateter , Humanos , Fibrilação Atrial/diagnóstico por imagem , Fibrilação Atrial/cirurgia , Resultado do Tratamento , Átrios do Coração/diagnóstico por imagem , Átrios do Coração/cirurgia , Ablação por Cateter/efeitos adversos , Ablação por Cateter/métodos , Recidiva
10.
Opt Express ; 32(7): 11259-11270, 2024 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-38570977

RESUMO

Photonic topological insulators with topologically protected edge states featuring one-way, robustness and backscattering-immunity possess extraordinary abilities to steer and manipulate light. In this work, we construct a topological heterostructure (TH) consisting of a domain of nontrivial pseudospin-type topological photonic crystals (PCs) sandwiched between two domains of trivial PCs based on two-dimensional all-dielectric core-shell PCs in triangle lattice. We consider three THs with different number of layers in the middle nontrivial domain (i.e., one-layer, two-layer, three-layer) and demonstrate that the projected band diagrams of the three THs host interesting topological waveguide states (TWSs) with properties of one-way, large-area, broad-bandwidth and robustness due to coupling effect of the helical edge states associated with the two domain-wall interfaces. Moreover, taking advantage of the tunable bandgap between the TWSs by the layer number of the middle domain due to the coupling effect, a topological Y-splitter with functionality of wavelength division multiplexing is explicitly demonstrated exploiting the unique feature of the dispersion curves of TWSs in the three THs. Our work not only offers a new method to realize pseudospin-polarized large-area TWSs with tunable mode-width, but also could provide new opportunities for practical applications in on-chip multifunctional (i.e., wavelength division multiplexing) photonic devices with topological protection and information processing with pseudospin-dependent transport.

11.
Protein Expr Purif ; 216: 106431, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38184161

RESUMO

Human pepsinogens (mainly pepsinogen I and pepsinogen II) are the major inactive precursor forms of the digestive enzyme pepsin which play a crucial role in protein digestion. The levels and ratios of human pepsinogens have demonstrated potential as diagnostic biomarkers for gastrointestinal diseases, particularly gastric cancer. Nanobodies are promising tools for the treatment and diagnosis of diseases, owing to their unique recognition properties. In this study, recombinant human pepsinogens proteins were expressed and purified as immunized antigens. We constructed a VHH phage library and identified several nanobodies via phage display bio-panning. We determined the binding potency and cross-reactivity of these nanobodies. Our study provides technical support for developing immunodiagnostic reagents targeting human pepsinogens.


Assuntos
Pepsinogênios , Anticorpos de Domínio Único , Humanos , Pepsinogênios/metabolismo , Anticorpos de Domínio Único/genética , Mucosa Gástrica/metabolismo , Pepsina A
12.
Pacing Clin Electrophysiol ; 47(1): 58-65, 2024 01.
Artigo em Inglês | MEDLINE | ID: mdl-38010824

RESUMO

BACKGROUND: Sodium-glucose cotransporter 2 inhibitors (SGLT2i) is reported to reduce incident atrial fibrillation (AF) in patients with or without diabetes; however, its cardiovascular (CV) benefit for AF patients remains unclear. SS AIMS: To investigate the effect of SGLT2i on the incidence of CV events in patients with AF. METHODS: Six randomized controlled trials (RCTs) assessing the effects of SGLT2i on CV outcomes in patients with or without AF were included (PROSPERO: CRD 42023431535). The primary endpoint was the composite outcome of heart failure (HF) hospitalization and CV death. Additionally, we assessed the effects of treatment in prespecified subgroups on HF hospitalization, CV death, and all-cause mortality. RESULTS: Among 38,529 participants from all trials, 5018 patients with AF were treated with SGLT2i. The follow-up period of these trials ranged from 2.3 to 3.3 years. SGLT2i treatment was significantly associated with the risk reduction of primary endpoint in patients with AF (risk ratio [RR] 0.81, 95% confidence interval [CI] 0.74-0.88; p < 0.001), consistent with the finding in the general population (p for interaction = 0.76). SGLT2i was also associated with a consistent reduction in the risk of HF hospitalization in patients with AF (RR 0.76, 95% CI 0.69-0.84; p < 0.001) or not (RR 0.72, 95% CI 0.64-0.80; p < 0.0001), with no statistical difference between them (p for interaction = 0.41). Meta-regression further revealed no significant association between the prevalence of HF with reduced ejection fraction or diabetes and the effect size of SGLT2i. CONCLUSIONS: The treatment effects of SGLT2i were associated with a lower incidence of CV events, especially HF hospitalization, in patients with AF.


Assuntos
Fibrilação Atrial , Diabetes Mellitus , Insuficiência Cardíaca , Inibidores do Transportador 2 de Sódio-Glicose , Humanos , Fibrilação Atrial/tratamento farmacológico , Inibidores do Transportador 2 de Sódio-Glicose/uso terapêutico , Ensaios Clínicos Controlados Aleatórios como Assunto , Insuficiência Cardíaca/tratamento farmacológico , Insuficiência Cardíaca/epidemiologia
13.
Pacing Clin Electrophysiol ; 47(4): 518-524, 2024 04.
Artigo em Inglês | MEDLINE | ID: mdl-38407374

RESUMO

BACKGROUND: Left bundle branch block (LBBB) and atrial fibrillation (AF) are commonly coexisting conditions. The impact of LBBB on catheter ablation of AF has not been well determined. This study aims to explore the long-term outcomes of patients with AF and LBBB after catheter ablation. METHODS: Forty-two patients with LBBB of 11,752 patients who underwent catheter ablation of AF from 2011 to 2020 were enrolled as LBBB group. After propensity score matching in a 1:4 ratio, 168 AF patients without LBBB were enrolled as non-LBBB group. Late recurrence and a composite endpoint of stroke, all-cause mortality, and cardiovascular hospitalization were compared between the two groups. RESULTS: Late recurrence rate was significantly higher in the LBBB group than that in the non-LBBB group (54.8% vs. 31.5%, p = .034). Multivariate analysis showed that LBBB was an independent risk factor for late recurrence after catheter ablation of AF (hazard ratio [HR] 2.19, 95% confidence interval [CI] 1.09-4.40, p = .031). LBBB group was also associated with a significantly higher incidence of the composite endpoint (21.4% vs. 6.5%, HR 3.98, 95% CI 1.64-9.64, p = .002). CONCLUSIONS: LBBB was associated with a higher risk for late recurrence and a higher incidence of composite endpoint in the patients underwent catheter ablation.


Assuntos
Fibrilação Atrial , Ablação por Cateter , Acidente Vascular Cerebral , Humanos , Bloqueio de Ramo/etiologia , Fatores de Risco , Acidente Vascular Cerebral/etiologia , Ablação por Cateter/efeitos adversos , Resultado do Tratamento , Recidiva
14.
Transfus Med ; 34(2): 136-141, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38258949

RESUMO

BACKGROUND: Hepatitis B virus (HBV) reactivity in individual immunologic and nucleic acid tests (NAT) tests does not represent the true infectious status of the blood donor. This study discusses the use of confirmatory tests to determine when deferral of blood donors is appropriate. METHODS: HBsAg or HBV NAT reactive samples were confirmed via a neutralisation test. All the HBsAg reactive but neutralisation test negative samples were subjected to further anti-HBc testing. The receiver operating characteristic curve was used to obtain the best threshold value using signal-to-cut-off ratios of two HBsAg enzyme-linked immunosorbent assay reagents. RESULTS: Of the 780 HBV reactive samples collected, there were 467 HBsAg reactive but HBV DNA negative samples, of which 65 (13.92%) and 402 (86.08%) were neutralisation test positive and negative, respectively. Of the 402, 91 samples (30% of tested samples) were anti-HBc reactive. HBV DNA positive specimens negative by virus neutralisation were >80% HBcAg positive. A screening strategy was proposed for Chinese blood collection agencies. CONCLUSION: These findings suggest that adopting a screening algorithm for deferring HBV reactive blood donors based on HBsAg and NAT testing followed with HBsAg S/CO consideration and HBcAg testing can be both safe and feasible in China.


Assuntos
Antígenos do Núcleo do Vírus da Hepatite B , Hepatite B , Humanos , Antígenos de Superfície da Hepatite B , Doadores de Sangue , DNA Viral , Hepatite B/prevenção & controle , Vírus da Hepatite B/genética , Anticorpos Anti-Hepatite B
15.
BMC Public Health ; 24(1): 581, 2024 Feb 23.
Artigo em Inglês | MEDLINE | ID: mdl-38395820

RESUMO

BACKGROUND: Despite technological, political and economic progress, Pakistan is still a traditionally patriarchal society, and cultural norms curb women's freedom of socialization, which contributes to poor mental health. The digital technology spaces are rampant with male dominance, and offline cultural behaviours are replicated. Therefore, the current research in Pakistan intends to focus solely on women, their social media uses and the consequent impact on their psychological well-being. Furthermore, the mediation role of social capital is explored, which is linked to women's socialization. In virtual communication, women can expand their connection or remain limited to known people. METHODS: An online survey collected 240 responses from women social media users. The questionnaire was divided into demographics, social media use patterns like access, online time, frequency of use, social media uses, online social capital and psychological well-being. The obtained responses were statistically analyzed using Smart PLS. RESULTS: Pakistani women use social media extensively; however, their uses are culturally influenced. The women use social media and socialize online but do not openly disclose their personalities and emotions to extend the connection. They seek information only from acquaintances and do not trust newly developed online contacts. Therefore, the mediation role of bonding social capital is significant, referring to the importance of close ties and trust in psychological well-being. Though virtual spaces provide an opportunity for bridging social capital, women use social media for socialization; however, it doesn't contribute to women's psychological well-being. CONCLUSION: Despite the higher penetration of digital technologies, cultural power still rules in developing countries like Pakistan. Social media uses are gender- and culturally specific, contributing to psychological well-being and developing social capital. The results from Pakistani society recommend ensuring a secure digital experience for women to get maximum benefits from social media and enhance their psychological well-being.


Assuntos
Capital Social , Mídias Sociais , Feminino , Masculino , Humanos , Bem-Estar Psicológico , Comportamento Social , Identidade de Gênero
16.
J Biol Chem ; 298(3): 101581, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-35038452

RESUMO

RNA polymerase III (pol III) products play fundamental roles in a variety of cellular processes, including protein synthesis and cancer cell proliferation. In addition, dysregulation of pol III-directed transcription closely correlates with tumorigenesis. It is therefore of interest to identify novel pathways or factors governing pol III-directed transcription. Here, we show that transcription factor (TF) GATA binding protein 4 (GATA4) expression in SaOS2 cells was stimulated by the silencing of filamin A (FLNA), a repressor of pol III-directed transcription, suggesting that GATA4 is potentially associated with the regulation of pol III-directed transcription. Indeed, we show that GATA4 expression positively correlates with pol III-mediated transcription and tumor cell proliferation. Mechanistically, we found that GATA4 depletion inhibits the occupancies of the pol III transcription machinery factors at the loci of pol III target genes by reducing expression of both TFIIIB subunit TFIIB-related factor 1 and TFIIIC subunit general transcription factor 3C subunit 2 (GTF3C2). GATA4 has been shown to activate specificity factor 1 (Sp1) gene transcription by binding to the Sp1 gene promoter, and Sp1 has been confirmed to activate pol III gene transcription by directly binding to both Brf1 and Gtf3c2 gene promoters. Thus, the findings from this study suggest that GATA4 links FLNA and Sp1 signaling to form an FLNA/GATA4/Sp1 axis to modulate pol III-directed transcription and transformed cell proliferation. Taken together, these results provide novel insights into the regulatory mechanism of pol III-directed transcription.


Assuntos
Filaminas , Fator de Transcrição GATA4 , Proteínas Quinases , RNA Polimerase III , Proliferação de Células , Filaminas/genética , Filaminas/metabolismo , Fator de Transcrição GATA4/genética , Fator de Transcrição GATA4/metabolismo , Proteínas Quinases/metabolismo , RNA Polimerase III/metabolismo , Transdução de Sinais , Fatores de Transcrição/genética , Transcrição Gênica
17.
BMC Genomics ; 24(1): 571, 2023 Sep 26.
Artigo em Inglês | MEDLINE | ID: mdl-37752438

RESUMO

BACKGROUND: Malvaceae is an economically important plant family of 4,225 species in nine subfamilies. Phylogenetic relationships among the nine subfamilies have always been controversial, especially for Brownlowioideae, whose phylogenetic position remains largely unknown due to the lack of samples in previous analysis datasets. To greatly clarify the phylogenetic relationship of Malvaceae, we newly sequenced and assembled the plastome of Diplodiscus trichospermus taxonomically located in Brownlowioideae, and downloaded the allied genomes from public database to build a dataset covering all subfamily members of Malvaceae. RESULTS: The annotation results showed that the plastome of Diplodiscus trichospermus has a typical quadripartite structure, comprising 112 unique genes, namely 78 protein-coding genes, 30 tRNA genes and 4 rRNA genes. The total length was 158,570 bp with 37.2% GC content. Based on the maximum likelihood method and Bayesian inference, a robust phylogenetic backbone of Malvaceae was reconstructed. The topology showed that Malvaceae was divided distinctly into two major branches which were previously recognized as Byttneriina and Malvadendrina. In the Malvadendrina clade, Malvoideae and Bombacoideae formed, as always, a close sister clade named as Malvatheca. Subfamily Helicteroideae occupied the most basal position and was followed by Sterculioideae which was sister to the alliance of Malvatheca, Brownlowioideae, Dombeyoideae, and Tilioideae. Brownlowioideae together with the clade comprising Dombeyoideae and Tilioideae formed a sister clade to Malvatheca. In addition, one specific conservation SSR and three specific palindrome sequences were observed in Brownlowioideae. CONCLUSIONS: In this study, the phylogenetic framework of subfamilies in Malvaceae has been resolved clearly based on plastomes, which may contribute to a better understanding of the classification and plastome evolution for Malvaceae.


Assuntos
Genoma de Cloroplastos , Malvaceae , Filogenia , Malvaceae/genética , Teorema de Bayes , Sequência de Bases
18.
J Transl Med ; 21(1): 630, 2023 09 16.
Artigo em Inglês | MEDLINE | ID: mdl-37716978

RESUMO

BACKGROUND: Diffuse large B-cell lymphoma (DLBCL) is an aggressive malignancy. Neutrophil extracellular traps (NETs) are pathogen-trapping structures in the tumor microenvironment that affect DLBCL progression. However, the predictive function of NET-related genes (NRGs) in DLBCL has received little attention. This study aimed to investigate the interaction between NRGs and the prognosis of DLBCL as well as their possible association with the immunological microenvironment. METHODS: The gene expression and clinical data of patients with DLBCL were downloaded from the Gene Expression Omnibus database. We identified 148 NRGs through the manual collection of literature. GSE10846 (n = 400, GPL570) was used as the training dataset and divided into training and testing sets in a 7:3 ratio. Univariate Cox regression analysis was used to identify overall survival (OS)-related NETs, and the least absolute shrinkage and selection operator was used to evaluate the predictive efficacy of the NRGs. Kaplan-Meier plots were used to visualize survival functions. Receiver operating characteristic (ROC) curves were used to assess the prognostic predictive ability of NRG-based features. A nomogram containing the clinical information and prognostic scores of the patients was constructed using multivariate logistic regression and Cox proportional risk regression models. RESULTS: We identified 36 NRGs that significantly affected patient overall survival (OS). Eight NRGs (PARVB, LYZ, PPARGC1A, HIF1A, SPP1, CDH1, S100A9, and CXCL2) were found to have excellent predictive potential for patient survival. For the 1-, 3-, and 5-year survival rates, the obtained areas under the receiver operating characteristic curve values were 0.8, 0.82, and 0.79, respectively. In the training set, patients in the high NRG risk group presented a poorer prognosis (p < 0.0001), which was validated using two external datasets (GSE11318 and GSE34171). The calibration curves of the nomogram showed that it had excellent predictive ability. Moreover, in vitro quantitative real-time PCR (qPCR) results showed that the mRNA expression levels of CXCL2, LYZ, and PARVB were significantly higher in the DLBCL group. CONCLUSIONS: We developed a genetic risk model based on NRGs to predict the prognosis of patients with DLBCL, which may assist in the selection of treatment drugs for these patients.


Assuntos
Armadilhas Extracelulares , Linfoma Difuso de Grandes Células B , Humanos , Prognóstico , Nomogramas , Linfoma Difuso de Grandes Células B/genética , Calgranulina B , Microambiente Tumoral
19.
Anticancer Drugs ; 34(6): 791-796, 2023 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-36729978

RESUMO

Osimertinib is recommended as the first-line treatment of advanced non-small cell lung cancer (NSCLC) in adults. The most commonly reported adverse events for osimertinib are skin effects, diarrhea, nausea, decreased appetite, fatigue, paronychia, and stomatitis. Severe thrombocytopenia is rarely reported. We present a case of severe thrombocytopenia in a 70-year-old NSCLC patient caused by osimertinib combined with sitagliptin. After remission of thrombocytopenia, the patient was well tolerated with osimertinib re-administration in the absence of sitagliptin. We speculated that declined platelet count might be related to the interaction between osimertinib and sitagliptin by acting with a synergistic effect on platelets. Osimertinib rechallenge can be considered after discontinuing drugs that may contribute to platelet decline if possible, and making a careful assessment of complete blood count and risk of bleeding.


Assuntos
Carcinoma Pulmonar de Células não Pequenas , Neoplasias Pulmonares , Trombocitopenia , Adulto , Humanos , Idoso , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Neoplasias Pulmonares/tratamento farmacológico , Fosfato de Sitagliptina/uso terapêutico , Receptores ErbB/genética , Compostos de Anilina/uso terapêutico , Trombocitopenia/induzido quimicamente , Inibidores de Proteínas Quinases/uso terapêutico , Mutação
20.
Europace ; 25(7)2023 07 04.
Artigo em Inglês | MEDLINE | ID: mdl-37417712

RESUMO

AIMS: After radiofrequency catheter ablation (RFCA) of atrial fibrillation (AF), the effect of very-early (within 48 h) symptomatic recurrence (VESR) on late (after 3 months of RFCA) recurrence (LR) has been seldomly reported. We aimed to explore the relationship between VESR and LR among post-RFCA patients. METHODS AND RESULTS: This was a single-centre prospective cohort study that enrolled 6887 AF patients who received the first RFCA procedure from June 2018 to December 2021 at Beijing Anzhen Hospital. Patients were divided into four groups based on VESR and early (from 48 h to 3 months after RFCA) recurrence (ER): Group A (no VESR, no ER); Group B (VESR but no ER); Group C (ER but no VESR); and Group D (both VESR and ER). Three hundred and thirty (4.79%) patients experienced VESR (Groups B and D). With an average follow-up of 14.7 months after grouping, the Kaplan-Meier curve showed that LR risk in VESR patients was higher than in other patients (log-rank, P < 0.001), and the difference was significant in both paroxysmal (log-rank, P < 0.001) and persistent (log-rank, P < 0.001) AF patients (P for interaction = 0.118). In multivariate analysis, Groups B, C, and D were associated with a 2.161-, 5.409-, and 7.401-fold increase in the risk of LR, respectively. What is more, compared with Group A, VESR-atrial tachycardia and VESR-AF were related to a 3.467- and 5.564-fold LR risk, respectively. In VESR patients, classification based on ER and VESR modes improved the prediction potential of LR risk. CONCLUSION: Very-early symptomatic recurrence is associated with an increased risk of LR.


Assuntos
Fibrilação Atrial , Ablação por Cateter , Humanos , Fibrilação Atrial/diagnóstico , Fibrilação Atrial/cirurgia , Fibrilação Atrial/etiologia , Estudos Prospectivos , Resultado do Tratamento , Fatores de Risco , Fatores de Tempo , Recidiva , Ablação por Cateter/efeitos adversos , Ablação por Cateter/métodos , Doença Crônica
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