Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 260
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
Nucleic Acids Res ; 52(1): 404-419, 2024 Jan 11.
Artigo em Inglês | MEDLINE | ID: mdl-38000383

RESUMO

The bacterial ribonuclease RNase E plays a key role in RNA metabolism. Yet, with a large substrate spectrum and poor substrate specificity, its activity must be well controlled under different conditions. Only a few regulators of RNase E are known, limiting our understanding on posttranscriptional regulatory mechanisms in bacteria. Here we show that, RebA, a protein universally present in cyanobacteria, interacts with RNase E in the cyanobacterium Anabaena PCC 7120. Distinct from those known regulators of RNase E, RebA interacts with the catalytic region of RNase E, and suppresses the cleavage activities of RNase E for all tested substrates. Consistent with the inhibitory function of RebA on RNase E, depletion of RNase E and overproduction of RebA caused formation of elongated cells, whereas the absence of RebA and overproduction of RNase E resulted in a shorter-cell phenotype. We further showed that the morphological changes caused by altered levels of RNase E or RebA are dependent on their physical interaction. The action of RebA represents a new mechanism, potentially conserved in cyanobacteria, for RNase E regulation. Our findings provide insights into the regulation and the function of RNase E, and demonstrate the importance of balanced RNA metabolism in bacteria.


Assuntos
Anabaena , Endorribonucleases , Anabaena/genética , Cianobactérias/genética , Cianobactérias/metabolismo , Endorribonucleases/genética , Endorribonucleases/metabolismo , RNA , RNA Bacteriano/genética , RNA Bacteriano/metabolismo
2.
J Am Chem Soc ; 146(11): 7658-7667, 2024 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-38452365

RESUMO

High-power phosphor-converted white light-emitting diodes (hp-WLEDs) have been widely involved in modern society as outdoor lighting sources. In these devices, due to the Joule effect, the high applied currents cause high operation temperatures (>500 K). Under these conditions, most phosphors lose their emission, an effect known as thermal quenching (TQ). Here, we introduce a zero-dimensional (0D) metal halide, Rb3InCl6:xSb3+, as a suitable anti-TQ phosphor offering robust anti-TQ behavior up to 500 K. We ascribe this behavior of the metal halide to two factors: (1) a compensation process via thermally activated energy transfer from structural defects to emissive centers and (2) an intrinsic structural rigidity of the isolated octahedra in the 0D structure. The anti-TQ phosphor-based WLEDs can stably work at a current of 2000 mA. The low synthesis cost and nontoxic composition reported here can herald a new generation of anti-TQ phosphors for hp-WLED.

3.
Int Arch Allergy Immunol ; : 1-12, 2024 May 24.
Artigo em Inglês | MEDLINE | ID: mdl-38797160

RESUMO

INTRODUCTION: Kamebakaurin is an active constituent of both Rabdosia japonica and Rabdosia excisa, which are utilized in Chinese traditional medicine for improving symptoms in patients with allergies. We investigated the molecular mechanisms of the anti-allergic effects of kamebakaurin using BMMCs. METHODS: The degranulation ratio, histamine release, and the interleukin (IL)-4, leukotriene B4 (LTB4), and cysteinyl leukotriene productions on antigen-triggered BMMC were investigated. Additionally, the effects of kamebakaurin on signal transduction proteins were examined by Western blot and binding to the Syk and Lyn kinase domain was calculated. The effects of kamebakaurin on antigen-induced hyperpermeability were investigated using mouse model. RESULTS: At 10 µm, kamebakaurin partially inhibited degranulation, histamine release, and IL-4 production. At 30 µm, kamebakaurin partially reduced LTB4 and cysteinyl leukotriene productions and suppressed degranulation, histamine release, and IL-4 production. Phosphorylation of both Syk Y519/520 and its downstream protein, Gab2, was reduced by kamebakaurin, and complete inhibition was observed with 30 µm kamebakaurin. In contrast, phosphorylation of Erk was only partially inhibited, even in the presence of 30 µm kamebakaurin. Syk Y519/520 is known to be auto-phosphorylated via intramolecular ATP present in its own ATP-binding site, and this auto-phosphorylation triggers degranulation, histamine release, and IL-4 production. Docking simulation study indicated kamebakaurin blocked ATP binding to the ATP-binding site in Syk. Therefore, inhibition of Syk auto-phosphorylation by kamebakaurin binding to the Syk ATP-binding site appeared to cause a reduction of histamine release and IL-4 production. Kamebakaurin inhibited antigen-induced vascular hyperpermeability in a dose-dependent fashion but did not reduce histamine-induced vascular hyperpermeability. CONCLUSION: Kamebakaurin ameliorates allergic symptoms via inhibition of Syk phosphorylation; thus, kamebakaurin could be a lead compound for the new anti-allergic drug.

4.
Age Ageing ; 53(7)2024 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-38984694

RESUMO

OBJECTIVE: Whether physical activity could reduce the risk of atrial fibrillation (AF) remains unclear. This study was to investigate the relationship of leisure-time physical activity (LTPA) with AF incidence among Chinese older adults. METHODS: A total of 3253 participants aged ≥60 years from the Guangzhou Heart Study were successfully followed between March 2018 and September 2019. LTPA was assessed using a modified Global Physical Activity Questionnaire. AF was ascertained by 12-lead electrocardiograms, 24-hour single-lead Holter and clinical examination. The Cox proportional hazards model was used to the estimate hazard ratio (HR) and 95% confidence interval (CI) after adjustment for confounders, and the population-attributable fraction (PAF) was estimated. RESULTS: A total of 76 (2.34%) new-onset cases of AF were identified during a median of 31.13 months of follow-up. After adjustment for confounders, subjects who had LTPA at least 10.0 metabolic equivalent (MET)-hours/week had a 55% lower risk of developing AF (HR: 0.45, 95%CI: 0.25-0.81), and at least 20 MET-hours/week reduced the risk by 45% (HR: 0.55, 95%CI: 0.34-0.92). At least 11% (PAF: 11%, 95%CI: 0%-20%) or 14% (PAF: 14%, 95%CI: 0%-26%) of AF cases could be avoided, respectively, if the subjects do LTPA at least 10 MET-hours/week or 20 MET-hours/week. A significant exposure-response trend was also observed between LTPA and AF risk (Plinear-trend = 0.002). For a specific LTPA, doing housework was associated with a 43% reduced risk, while engaging in ball games was associated with an increased risk. CONCLUSION: This prospective cohort study indicated that a higher LTPA volume was associated with a lower AF risk in Chinese older adults.


Assuntos
Fibrilação Atrial , Exercício Físico , Atividades de Lazer , Humanos , Fibrilação Atrial/epidemiologia , Fibrilação Atrial/diagnóstico , Fibrilação Atrial/prevenção & controle , Masculino , Feminino , Idoso , Estudos Prospectivos , Incidência , Pessoa de Meia-Idade , China/epidemiologia , Fatores de Risco
5.
Radiology ; 307(5): e221408, 2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-37367448

RESUMO

Background Current guidelines recommend the use of conventional US for risk stratification and management of thyroid nodules. However, fine-needle aspiration (FNA) is often recommended in benign nodules. Purpose To compare the diagnostic performance of multimodality US (including conventional US, strain elastography, and contrast-enhanced US [CEUS]) with the American College of Radiology Thyroid Imaging Reporting and Data System (TI-RADS) in the recommendation of FNA for thyroid nodules to reduce unnecessary biopsies. Materials and Methods In this prospective study, 445 consecutive participants with thyroid nodules from nine tertiary referral hospitals were recruited between October 2020 and May 2021. With univariable and multivariable logistic regression, the prediction models incorporating sonographic features, evaluated with interobserver agreement, were constructed and internally validated with bootstrap resampling technique. In addition, discrimination, calibration, and decision curve analysis were performed. Results A total of 434 thyroid nodules confirmed at pathologic analysis (259 malignant thyroid nodules) in 434 participants (mean age, 45 years ± 12 [SD]; 307 female participants) were included. Four multivariable models incorporated participant age, nodule features at US (proportion of cystic components, echogenicity, margin, shape, punctate echogenic foci), elastography features (stiffness), and CEUS features (blood volume). In recommending FNA in thyroid nodules, the highest area under the receiver operating characteristic curve (AUC) was 0.85 (95% CI: 0.81, 0.89) for the multimodality US model, and the lowest AUC was 0.63 (95% CI: 0.59, 0.68) for TI-RADS (P < .001). At the 50% risk threshold, 31% (95% CI: 26, 38) of FNA procedures could be avoided with multimodality US compared with 15% (95% CI: 12, 19) with TI-RADS (P < .001). Conclusion Multimodality US had better performance in recommending FNA to avoid unnecessary biopsies than the TI-RADS. Clinical trial registration no. NCT04574258 © RSNA, 2023 Supplemental material is available for this article.


Assuntos
Nódulo da Glândula Tireoide , Adulto , Feminino , Humanos , Pessoa de Meia-Idade , Biópsia por Agulha Fina , Imagem Multimodal , Estudos Prospectivos , Nódulo da Glândula Tireoide/diagnóstico por imagem , Nódulo da Glândula Tireoide/patologia , Ultrassonografia/métodos
6.
Bioorg Med Chem Lett ; 82: 129149, 2023 02 15.
Artigo em Inglês | MEDLINE | ID: mdl-36690039

RESUMO

A series of 1-O-acyl- and 1-oxo-kamebanin analogues were prepared from kamebanin, isolated from Rabdosia excisa and their cytotoxicity was assayed on HL60 promyelocytic leukemia cells and HCT116 human colon cancer cells. The structure-activity relationship study showed that the presence of 1-O-acyl groups of a C3-C5 carbon chain increased the cytotoxic activity.


Assuntos
Antineoplásicos , Isodon , Humanos , Antineoplásicos/farmacologia , Relação Estrutura-Atividade , Células HL-60 , Células HCT116
7.
Ren Fail ; 45(2): 2272717, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37870491

RESUMO

BACKGROUND: The role of inflammation in the pathogenesis of type 2 diabetes mellitus (T2DM) is well established. Lyn, a member of the nonreceptor protein tyrosine kinase Src family, has been reported to modulate inflammatory signaling pathways. METHODS: Lyn expression was assessed in kidney biopsies of 11 patients with diabetic kidney disease (DKD) and in kidney tissues of streptozotocin (STZ)-induced DKD mice. 102 recruited T2DM patients were divided into three groups: normoalbuminuria, microalbuminuria and macroalbuminuria. Twenty-one healthy volunteers were recruited as a control group. Clinical data, blood and urine samples of all individuals were collected for analysis. RESULTS: Lyn expression was augmented in the kidneys of DKD patients and STZ-induced diabetic mice. Compared with control and normoalbuminuria groups, both mRNA and protein expression of Lyn in peripheral blood mononuclear cells (PBMCs) in the macroalbuminuria group were significantly increased (p < .05). Elevated Lyn levels were independently related to urine albumin/urine creatinine ratio and were positively associated with key inflammatory factors, namely interleukin-1ß, monocyte chemoattractant protein-1, and tumor necrosis factor-α. Additionally, Lyn exhibited a noteworthy connection with renal tubular injury indicators, specifically urinary neutrophil gelatinase-associated lipocalin and urinary retinol binding protein. ROC curve analysis showed that Lyn could predict albuminuria in diabetic patients with an area under the curve of 0.844 (95% CI: 0.764-0.924). CONCLUSION: Lyn levels in PBMCs exhibited a positive correlation with the severity of albuminuria, renal tubular damage, and inflammatory responses. Hence, Lyn may be a compelling candidate for predicting albuminuria levels in diabetes.


Assuntos
Diabetes Mellitus Experimental , Diabetes Mellitus Tipo 2 , Nefropatias Diabéticas , Humanos , Animais , Camundongos , Regulação para Cima , Leucócitos Mononucleares/metabolismo , Albuminúria/etiologia , Albuminúria/urina , Proteínas Quinases/metabolismo , Diabetes Mellitus Experimental/complicações , Biomarcadores , Rim/metabolismo
8.
Zhongguo Zhong Yao Za Zhi ; 48(17): 4722-4730, 2023 Sep.
Artigo em Zh | MEDLINE | ID: mdl-37802811

RESUMO

This study aims to investigate the regulatory effects of Astragalus polysaccharide(APS) and APS combined with 5-fluorouracil(5-FU) on indoleamine-2,3-dioxygenase(IDO1) in the colon tumor microenvironment. Sixty Balb/c mice were randomized into a blank group, a model group, an APS group, an APS + 5-FU group, an APS + low-dose 5-FU group, and a 5-FU group. A tumor model was established by subcutaneous transplantation with CT-26 mouse colon cancer cells in other groups except the blank group. After successful modeling, each group was treated with corresponding drugs for 7 days. The general condition, body weight, and tumor volume of the mice were observed and measured daily during the treatment period. The mice were sacrificed at the end of treatment, and the tumor suppression rate and spleen index of the mice were calculated. Western blot and fluorescence quantitative PCR were employed to determine the protein and mRNA levels, respectively, of IDO1 in the tumor tissue of mice. High performance liquid chromatography was employed to measure the levels of tryptophan(Trp) and kynurenine(Kyn) in the tumor tissue of mice. Hematoxylin-eosin(HE) staining was performed to observe the histological changes of the tumor tissue, and immunohistochemistry to detect the changes of CD4 and CD8 expression in the tumor tissue. Compared with that in the model group, the tumor volume of mice in each treatment group significantly reduced. The body weights of mice in APS + 5-FU group and 5-FU group significantly reduced from day 4 to day 7 of treatment. In addition, the APS + 5-FU group and 5-FU group showed significantly decreased spleen index. The protein and mRNA levels of IDO1 were significantly down-regulated in the APS, APS + 5-FU, and APS + low-dose 5-FU groups. The drug interventions significantly increased the Trp content and decreased the Kyn content. The APS + 5-FU group showed significantly reduced infiltration of CD4~+ T lymphocytes and increased infiltration of CD8~+ T lymphocytes. APS inhibited the expression of IDO1 in the colon tumor microenvironment to increase CD8~+ T lymphocyte infiltration, and the combination of APS with 5-FU demonstrated better effect.


Assuntos
Neoplasias do Colo , Microambiente Tumoral , Camundongos , Animais , Neoplasias do Colo/tratamento farmacológico , Neoplasias do Colo/genética , Fluoruracila/farmacologia , Polissacarídeos/farmacologia , Linfócitos T CD8-Positivos/metabolismo , RNA Mensageiro/metabolismo
9.
Zhongguo Zhong Yao Za Zhi ; 48(4): 1032-1042, 2023 Feb.
Artigo em Zh | MEDLINE | ID: mdl-36872274

RESUMO

Based on transcriptome sequencing technology, the mouse model of prediabetes treated with Huangjing Qianshi Decoction was sequenced to explore the possible mechanism of treating prediabetes. First of all, transcriptome sequencing was performed on the normal BKS-DB mouse group, the prediabetic model group, and the Huangjing Qianshi Decoction treatment group(treatment group) to obtain differentially expressed genes in the skeletal muscle samples of mice. The serum biochemical indexes were detected in each group to screen out the core genes of Huangjing Qianshi Decoction in prediabetes. Gene Ontology(GO) database and Kyoto Encyclopedia of Genes and Genomes(KEGG) database were used to conduct signaling pathway enrichment analysis of differentially expressed genes, and real-time quantitative polymerase chain reaction(RT-qPCR) was used to verify them. The results showed that the levels of fasting blood glucose(FBG), fasting insulin(FINS), insulin resistance index(HOMA-IR), total cholesterol(TC), triglycerides(TG), and low-density lipoprotein cholesterol(LDL-C) in the mouse model were significantly decreased after treatment with Huangjing Qianshi Decoction. In the results of differential gene screening, there were 1 666 differentially expressed genes in the model group as compared with the normal group, and there were 971 differentially expressed genes in the treatment group as compared with the model group. Among them, interleukin-6(IL-6) and NR3C2 genes, which were closely related to the regulation of insulin resis-tance function, were significantly up-regulated between the model group and the normal group, and vascular endothelial growth factor A(VEGFA) genes were significantly down-regulated between the model group and the normal group. However, the expression results of IL-6, NR3C2, and VEGFA genes were adverse between the treatment group and the model group. GO functional enrichment analysis found that the biological process annotation mainly focused on cell synthesis, cycle, and metabolism; cell component annotation mainly focused on organelles and internal components; and molecular function annotation mainly focused on binding molecular functions. KEGG pathway enrichment analysis found that it involved the protein tyrosine kinase 6(PTK6) pathway, CD28-dependent phosphoinositide 3-kinase/protein kinase B(PI3K/AKT) pathway, p53 pathway, etc. Therefore, Huangjing Qianshi Decoction can improve the state of prediabetes, and the mechanism may be related to cell cycle and apoptosis, PI3K/AKT pathway, p53 pathway, and other biological pathways regulated by IL-6, NR3C2, and VEGFA.


Assuntos
Estado Pré-Diabético , Proteínas Proto-Oncogênicas c-akt , Animais , Camundongos , Fosfatidilinositol 3-Quinases , Fator A de Crescimento do Endotélio Vascular , Interleucina-6 , Transcriptoma , Proteína Supressora de Tumor p53 , Insulina , Colesterol
10.
Zhongguo Zhong Yao Za Zhi ; 48(19): 5356-5364, 2023 Oct.
Artigo em Zh | MEDLINE | ID: mdl-38114125

RESUMO

This study aims to investigate the mechanism of Linderae Radix water extract(LRWE) in the prevention and treatment of diarrhea-predominant irritable bowel syndrome(IBS-D) based on serum metabolomics. Eighteen 2-week-old male SD rats were randomized into control, IBS-D model, and LRWE groups. The rats in other groups except the control group received gavage of senna concentrate combined with restraint stress for the modeling of IBS-D. The rats in the LRWE group were administrated with LRWE(5.4 g·kg~(-1)) by gavage, and those in the control and IBS-D model groups with an equal volume of distilled water for a total of 14 days. The visceral sensitivity was evaluated by the abdominal withdrawal reflex(AWR) score, and the degree of diarrhea was assessed by the fecal water content(FWC). The morphological changes of the colon and the morphology and number of goblet cells were observed by hematoxylin-eosin(HE) and periodic acid-schiff(PAS) staining, respectively. Ultra-high performance liquid chromatography-tandem mass spectrometry(UPLC-MS/MS) was used for the screening of the potential biomarkers in the rat serum and their related metabolic pathways. The results showed that LRWE reduced the AWR score, decreased FWC, and alleviated visceral sensitivity and diarrhea symptoms in IBS-D rats. HE and PAS staining showed that LRWE mitigated low-grade intestinal inflammation and increased the number of mature secretory goblet cells in the colonic epithelium of IBS-D rats. A total of 25 potential biomarkers of LRWE in treating IBS-D were screened out in this study, which were mainly involved in riboflavin, tryptophan, glycine, serine and threonine metabolism, glyoxylate and dicarboxylate metabolism, and cysteine and methionine metabolism. The regulatory effects were the most significant on the riboflavin and tryptophan metabolism pathways. LRWE may alleviate the visceral hypersensitivity by promoting energy metabolism and amino acid metabolism, enhancing intestinal barrier function, and improving intestinal immune function in IBS-D rats.


Assuntos
Síndrome do Intestino Irritável , Ratos , Masculino , Animais , Síndrome do Intestino Irritável/tratamento farmacológico , Síndrome do Intestino Irritável/metabolismo , Água , Cromatografia Líquida , Triptofano , Ratos Sprague-Dawley , Espectrometria de Massas em Tandem , Diarreia/tratamento farmacológico , Biomarcadores , Riboflavina
11.
Opt Express ; 30(3): 4312-4326, 2022 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-35209670

RESUMO

Metasurfaces have made great progress in the last decade for generating miniature and integrated optical devices. The optical properties of metasurfaces can be tuned dynamically by integrating with phase-change materials. However, the efficiency of tunable metasurfaces remains a bit low, which is a disadvantage for the realistic applications of metasurfaces. Here, we demonstrate the tunable dielectric metasurfaces by structuring the phase-change material Ge2Sb2Te5. The unit cell of metasurface is composed of several Ge2Sb2Te5 nanopillars with different geometric parameters, and the incident light interacts with different nanopillars at diverse phases of Ge2Sb2Te5, leading to various functions. By elaborately arranging the Ge2Sb2Te5 nanopillars, various tunable optical devices have been realized, including tunable beam steering, reconfigurable metalens and switchable wave plate. The refractive direction, focal length and polarization state can be tuned through the phase transition of Ge2Sb2Te5. The phase-change metasurfaces based on Ge2Sb2Te5 nanostructures could be used in cameras, optical microscopy and adaptive optics.

12.
Opt Lett ; 47(23): 6073-6076, 2022 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-37219175

RESUMO

Metasurfaces have made great progress in the past decade in generating various planar optical devices. However, most metasurfaces exhibit their functions in either reflection mode or transmission mode, with the other mode unutilized. In this work, we demonstrate switchable transmissive and reflective metadevices by combining metasurfaces with vanadium dioxide. The composite metasurface can work as a transmissive metadevice, with one function for vanadium dioxide in the insulating phase, and is changed to a reflective metadevice with another function for vanadium dioxide in the metallic phase. By carefully designing the structures, the metasurface can be switched from a transmissive metalens to a reflective vortex generator, or between a transmissive beam steering and a reflective quarter-wave plate through the phase transition of vanadium dioxide. The switchable transmissive and reflective metadevices have potential applications in imaging, communication, and information processing.

13.
Pharmacol Res ; 184: 106464, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-36162600

RESUMO

Uveal melanoma (UM) is the most common intraocular cancer in adults. UMs are usually initiated by a mutation in GNAQ or GNA11 (encoding Gq or G11, respectively), unlike cutaneous melanomas (CMs), which usually carry a BRAF or NRAS mutation. Currently, there are no clinically effective targeted therapies for UM carrying Gq/11 mutations. Here, we identified a causal link between Gq activating mutations and hypersensitivity to bromodomain and extra-terminal (BET) inhibitors. BET inhibitors transcriptionally repress YAP via BRD4 regardless of Gq mutation status, independently of Hippo core components LATS1/2. In contrast, YAP/TAZ downregulation reduces BRD4 transcription exclusively in Gq-mutant cells and LATS1/2 double knockout cells, both of which are featured by constitutively active YAP/TAZ. The transcriptional interdependency between BRD4 and YAP identified in Gq-mutated cells is responsible for the preferential inhibitory effect of BET inhibitors on the growth and dissemination of Gq-mutated UM cells compared to BRAF-mutated CM cells in both culture cells and animal models. Our findings suggest BRD4 as a viable therapeutic target for Gq-driven UMs that are addicted to unrestrained YAP function.


Assuntos
Melanoma , Proteínas Nucleares , Animais , Subunidades alfa Gq-G11 de Proteínas de Ligação ao GTP/genética , Subunidades alfa Gq-G11 de Proteínas de Ligação ao GTP/metabolismo , Melanoma/tratamento farmacológico , Melanoma/genética , Mutação , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Proteínas Serina-Treonina Quinases , Proteínas Proto-Oncogênicas B-raf/genética , Transdução de Sinais , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Neoplasias Uveais
14.
Acta Pharmacol Sin ; 43(9): 2397-2409, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35165399

RESUMO

Rapalogs (everolimus and temsirolimus) are allosteric mTORC1 inhibitors and approved agents for advanced clear cell renal cell carcinoma (ccRCC), although only a subset of patients derive clinical benefit. Progress in genomic characterization has made it possible to generate comprehensive profiles of genetic alterations in ccRCC; however, the correlations between recurrent somatic mutations and rapalog efficacy remain unclear. Here, we demonstrate by using multiple patient-derived ccRCC cell lines that compared to PTEN-proficient cells, PTEN-deficient cells exhibit hypersensitivity to rapalogs. Rapalogs inhibit cell proliferation by inducing G0/G1 arrest without inducing apoptosis in PTEN-deficient ccRCC cell lines. Using isogenic cell lines generated by CRISPR/Cas9, we validate the correlation between PTEN loss and rapalog hypersensitivity. In contrast, deletion of VHL or chromatin-modifying genes (PBRM1, SETD2, BAP1, or KDM5C) fails to influence the cellular response to rapalogs. Our mechanistic study shows that ectopic expression of an activating mTOR mutant (C1483F) antagonizes PTEN-induced cell growth inhibition, while introduction of a resistant mTOR mutant (A2034V) enables PTEN-deficient ccRCC cells to escape the growth inhibitory effect of rapalogs, suggesting that PTEN loss generates vulnerability to mTOR inhibition. PTEN-deficient ccRCC cells are more sensitive to the inhibitory effects of temsirolimus on cell migration and tumor growth in zebrafish and xenograft mice, respectively. Of note, PTEN protein loss as detected by immunohistochemistry is much more frequent than mutations in the PTEN gene in ccRCC patients. Our study suggests that PTEN loss correlates with rapalog sensitivity and could be used as a marker for ccRCC patient selection for rapalog therapy.


Assuntos
Carcinoma de Células Renais , Neoplasias Renais , Animais , Carcinoma de Células Renais/tratamento farmacológico , Carcinoma de Células Renais/genética , Carcinoma de Células Renais/patologia , Humanos , Neoplasias Renais/tratamento farmacológico , Neoplasias Renais/genética , Neoplasias Renais/patologia , Inibidores de MTOR , Camundongos , Mutação , PTEN Fosfo-Hidrolase/genética , Serina-Treonina Quinases TOR/metabolismo , Proteínas Supressoras de Tumor/genética , Peixe-Zebra/metabolismo , Proteínas de Peixe-Zebra
15.
Acta Pharmacol Sin ; 43(7): 1803-1815, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34737422

RESUMO

The tumor suppressor gene BAP1 encodes a widely expressed deubiquitinase for histone H2A. Both hereditary and acquired mutations are associated with multiple cancer types, including cutaneous melanoma (CM), uveal melanoma (UM), and clear cell renal cell carcinoma (ccRCC). However, there is no personalized therapy for BAP1-mutant cancers. Here, we describe an epigenetic drug library screening to identify small molecules that exert selective cytotoxicity against BAP1 knockout CM cells over their isogenic parental cells. Hit characterization reveals that BAP1 loss renders cells more vulnerable to bromodomain and extraterminal (BET) inhibitor-induced transcriptional alterations, G1/G0 cell cycle arrest and apoptosis. The association of BAP1 loss with sensitivity to BET inhibitors is observed in multiple BAP1-deficient cancer cell lines generated by gene editing or derived from patient tumors as well as immunodeficient xenograft and immunocompetent allograft murine models. We demonstrate that BAP1 deubiquitinase activity reduces sensitivity to BET inhibitors. Concordantly, ectopic expression of RING1A or RING1B (H2AK119 E3 ubiquitin ligases) enhances sensitivity to BET inhibitors. The mechanistic study shows that the BET inhibitor OTX015 exerts a more potent suppressive effect on the transcription of various proliferation-related genes, especially MYC, in BAP1 knockout cells than in their isogenic parental cells, primarily by targeting BRD4. Furthermore, ectopic expression of Myc rescues the BET inhibitor-sensitizing effect induced by BAP1 loss. Our study reveals new approaches to specifically suppress BAP1-deficient cancers, including CM, UM, and ccRCC.


Assuntos
Carcinoma de Células Renais , Neoplasias Renais , Melanoma , Neoplasias Cutâneas , Animais , Carcinoma de Células Renais/tratamento farmacológico , Proteínas de Ciclo Celular , Humanos , Neoplasias Renais/genética , Melanoma/genética , Camundongos , Proteínas Nucleares , Fatores de Transcrição/genética , Proteínas Supressoras de Tumor/genética , Proteínas Supressoras de Tumor/metabolismo , Ubiquitina Tiolesterase/genética , Ubiquitina Tiolesterase/metabolismo , Neoplasias Uveais , Melanoma Maligno Cutâneo
16.
Neoplasma ; 69(1): 113-122, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34846158

RESUMO

Previous studies identified an association of low-density lipoprotein (LDL) levels and LDL receptor (LDLR) with renal cell carcinoma (RCC) development. This study investigated the expression and roles of LDLR in RCC. LDLR expression was examined in clear cell RCC (ccRCC) and adjacent normal kidney tissues, and its clinicopathological significance was analyzed. The role of LDLR in RCC cell proliferation, cell cycle, and invasion were assessed in RCC cells with LDLR stable knockdown. LDLR expression was higher in ccRCC tissues than in normal kidney tissues and increased with RCC progression. LDLR knockdown in RCC cells inhibited cell growth, migration and invasion, and induced G1/S cell cycle arrest. We identified an interaction between LDLR and EGFR, and EGFR signaling protein expression was reduced after LDLR knockdown. Our findings reveal that LDLR plays an important role in RCC carcinogenesis, suggesting that LDL and LDLR might be potential targets for therapeutic intervention in RCC.


Assuntos
Carcinoma de Células Renais , Neoplasias Renais , Carcinoma de Células Renais/genética , Linhagem Celular Tumoral , Movimento Celular , Proliferação de Células , Receptores ErbB/genética , Receptores ErbB/metabolismo , Regulação Neoplásica da Expressão Gênica , Humanos , Neoplasias Renais/genética , Receptores de LDL/genética
17.
Nephrology (Carlton) ; 27(1): 7-24, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34510645

RESUMO

End-stage renal disease (ESRD) patients are amongst the vulnerable groups and thus prioritized in the Coronavirus disease-2019 vaccination programmes. However, this cohort was excluded from vaccine-trials and yet shares the same vaccination scheme with the general population. Here, we explore trends of immune response-proportions amongst ESRD patients on renal replacement therapy for up to 4 weeks post-vaccination completion with Pfizer/Moderna vaccines. From inception to 10 July 2021, we searched six online-databases for articles reporting humoral and cellular immune response proportions for up to 4 weeks post booster-vaccination. We pooled the responders' proportions by meta-analysis and conducted a meta-regression stratifying outcomes by significant confounders. Twenty-seven eligible studies reported 2789 ESRD patients. 1337, 1452 and 477 were on haemodialysis, received kidney transplantation, and healthy controls, respectively. Haemodialysis patients' proportions of humoral and cellular immune responses varied from 87.29% (80.77-93.81)-88.78% (86.76-90.80) and 62.86% (56.56, 69.17)-85.78% (78.99, 92.57), respectively, between first- and fourth-weeks. Kidney transplant patients' proportions of humoral and cellular immune responses ranged from 2.6% (0.06-13.48)-29.87% (27.68, 32.07) and 5.13% (0.63-17.3)-59.84% (54.57-65.10), respectively, between first- and fourth-weeks. All healthy controls maintained ≥93% proportions of both responses throughout the follow-up. Study design and country of study influenced the pooled response proportions. Conclusively, haemodialysis and kidney transplant patients have lower proportions of humoral and cellular immune responses than healthy controls. However, haemodialysis patients' response proportions improve, reaching near healthy-control levels by the fourth week. Kidney transplant patients' lower responses' proportions also improve but remain significantly lower than healthy controls throughout four-weeks. The "one-size-fits-all" vaccination scheme might be inadequate for kidney transplant patients.


Assuntos
COVID-19/prevenção & controle , Imunidade Celular/imunologia , Falência Renal Crônica/terapia , Transplante de Rim , Diálise Renal , SARS-CoV-2/imunologia , Vacinação/efeitos adversos , Anticorpos Antivirais/imunologia , COVID-19/epidemiologia , Vacinas contra COVID-19/efeitos adversos , Comorbidade , Humanos , Imunogenicidade da Vacina , Falência Renal Crônica/epidemiologia , Fatores de Risco , Transplantados
18.
Chem Biodivers ; 19(10): e202200767, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-36098055

RESUMO

Two new C21 steroidal glycosides, brapreguanes A and B (1-2) were isolated from 75 % aqueous ethanol extract of Selaginella braunii Baker. Their structures were established by spectroscopic analyses (1D/2D NMR spectra and HR-ESI-MS). The absolute configurations of sugar were elucidated by enzymatic hydrolysis and GCMS analysis. In addition, all compounds were evaluated for the anti-proliferative activities against various human cancer cells in vitro. Compounds exhibited no inhibition to various human cancer cells.


Assuntos
Selaginellaceae , Humanos , Selaginellaceae/química , Estrutura Molecular , Glicosídeos/farmacologia , Glicosídeos/química , Açúcares , Etanol , Extratos Vegetais
19.
Hepatobiliary Pancreat Dis Int ; 21(6): 551-558, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-35000845

RESUMO

BACKGROUND: The optimal width of resection margin (RM) for hepatocellular carcinoma (HCC) remains controversial. This study aimed to investigate the value of imaging tumor capsule (ITC) and imaging tumor size (ITS) in guiding RM width for patients with HCC. METHODS: Patients who underwent hepatectomy for HCC in our center were retrospectively reviewed. ITC (complete/incomplete) and ITS (≤ 3 cm/> 3 cm) were assessed by preoperative magnetic resonance imaging (MRI). Using subgroup analyses based on ITC and ITS, the impact of RM width [narrow RM (< 5 mm)/wide RM (≥ 5 mm)] on recurrence-free survival (RFS), overall survival (OS), and RM recurrence was analyzed. RESULTS: A total of 247 patients with solitary HCC were included. ITC and ITS were independent predictors for RFS and OS in the entire cohort. In patients with ITS ≤ 3 cm, neither ITC nor RM width showed a significant impact on prognosis, and the incidence of RM recurrence was comparable between the narrow RM and wide RM groups (15.6% vs. 4.3%, P = 0.337). In patients with ITS > 3 cm and complete ITC, the narrow RM group exhibited comparable RFS, OS, and incidence of RM recurrence with the wide RM group (P = 0.606, 0.916, and 0.649, respectively). However, in patients with ITS > 3 cm and incomplete ITC, the wide RM group showed better RFS and OS and a lower incidence of RM recurrence compared with the narrow RM group (P = 0.037, 0.018, and 0.046, respectively). CONCLUSIONS: As MRI-based preoperative markers, conjoint analysis of ITC with ITS aids in determining RM width for solitary HCC patients. Narrow RM is applicable in patients with ITS ≤ 3 cm regardless of ITC status and in those with ITS > 3 cm and complete ITC. Wide RM is preferred in those with ITS > 3 cm and incomplete ITC.


Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , Humanos , Carcinoma Hepatocelular/diagnóstico por imagem , Carcinoma Hepatocelular/cirurgia , Neoplasias Hepáticas/diagnóstico por imagem , Neoplasias Hepáticas/cirurgia , Margens de Excisão , Estudos Retrospectivos , Recidiva Local de Neoplasia/patologia , Hepatectomia/efeitos adversos , Hepatectomia/métodos , Prognóstico
20.
BMC Surg ; 22(1): 298, 2022 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-35915446

RESUMO

BACKGROUND: Stapled haemorrhoidopexy (SH) has resulted in a unique collection of procedural complications with postoperative mucocele a particularly rare example. This study is designed to comprehensively describe the characteristics of rectal mucocele and discuss its pathogenesis following SH surgery. METHODS: A database of patients presenting with a rectal mucocele following an SH procedure was established and studied retrospectively. RESULTS: Seven patients (5 males; median age 32 years, range 20-75 years) were identified. All patients complained of variable anal discomfort with 5/7 presenting with inconstant anal pain, 2 with de novo evacuatory difficulty. These cases appeared at a median time of 6 months (range 2-84 months) after SH surgery. CONCLUSION: Rectal Mucocele develops when mucosal fragments become embedded and isolated under the mucosa. It is a preventable complication of SH surgery by ensuring correct purse string placement prior to stapled haemorrhoid excision.


Assuntos
Hemorroidas , Mucocele , Adulto , Idoso , Hemorroidas/cirurgia , Humanos , Masculino , Pessoa de Meia-Idade , Mucocele/etiologia , Mucocele/cirurgia , Complicações Pós-Operatórias/etiologia , Complicações Pós-Operatórias/cirurgia , Reto/cirurgia , Estudos Retrospectivos , Grampeamento Cirúrgico/efeitos adversos , Grampeamento Cirúrgico/métodos , Resultado do Tratamento , Adulto Jovem
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA