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1.
J Cell Biol ; 223(10)2024 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-39012625

RESUMO

The GTPase Cdc42 regulates polarized growth in most eukaryotes. In the bipolar yeast Schizosaccharomyces pombe, Cdc42 activation cycles periodically at sites of polarized growth. These periodic cycles are caused by alternating positive feedback and time-delayed negative feedback loops. At each polarized end, negative feedback is established when active Cdc42 recruits the Pak1 kinase to prevent further Cdc42 activation. It is unclear how Cdc42 activation returns to each end after Pak1-dependent negative feedback. We find that disrupting branched actin-mediated endocytosis disables Cdc42 reactivation at the cell ends. Using experimental and mathematical approaches, we show that endocytosis-dependent Pak1 removal from the cell ends allows the Cdc42 activator Scd1 to return to that end to enable reactivation of Cdc42. Moreover, we show that Pak1 elicits its own removal via activation of endocytosis. These findings provide a deeper insight into the self-organization of Cdc42 regulation and reveal previously unknown feedback with endocytosis in the establishment of cell polarity.


Assuntos
Complexo 2-3 de Proteínas Relacionadas à Actina , Polaridade Celular , Endocitose , Retroalimentação Fisiológica , Proteínas de Schizosaccharomyces pombe , Schizosaccharomyces , Proteína cdc42 de Ligação ao GTP , Quinases Ativadas por p21 , Schizosaccharomyces/metabolismo , Schizosaccharomyces/genética , Proteínas de Schizosaccharomyces pombe/metabolismo , Proteínas de Schizosaccharomyces pombe/genética , Quinases Ativadas por p21/metabolismo , Quinases Ativadas por p21/genética , Complexo 2-3 de Proteínas Relacionadas à Actina/metabolismo , Complexo 2-3 de Proteínas Relacionadas à Actina/genética , Proteína cdc42 de Ligação ao GTP/metabolismo , Proteína cdc42 de Ligação ao GTP/genética , Actinas/metabolismo
2.
Phys Chem Chem Phys ; 26(28): 19543-19553, 2024 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-38979972

RESUMO

Rational design of γ-alumina-based catalysts relies on an extensive understanding of the distribution of hydroxyl groups on the surface of γ-alumina and their physicochemical properties, which remain unclear and challenging to determine experimentally due to the structural complexity. In this work, by means of DFT and thermodynamic calculations, various hydroxylation modes of γ-alumina (110) and (100) surfaces at different OH coverages were evaluated, based on which a thermodynamic model to reflect the relationship between temperature and the surface structure was established and the stable hydroxylation modes under experimental conditions were predicted. This enables us to identify the experimentally measured IR spectra. The effect of hydroxyl coverages on the surface Lewis acidity was then analyzed, showing that the presence of hydroxyl groups could promote the Lewis acidity of neighboring Al sites. This work provides fundamental insights into the molecular level understanding of the surface properties of γ-alumina and benefits the rational design of alumina-based catalysts.

3.
Artigo em Inglês | MEDLINE | ID: mdl-38982698

RESUMO

BACKGROUND: Hemerocallis citrina Baroni (Huanghuacai), a plant of the genus Hemerocallis in the family Asphodelaceae, is widely planted in China. Based on our survey results, the chemical compounds in the essential oil of the flowers of Hemerocallis citrina Baroni (EOFHCB) and relevant pharmacological activities have never been studied systematically. OBJECTIVE: To preliminarily decipher the pharmacological activities and mechanisms of EOFHCB in the treatment of anxiety disorders by GC-MS, Network Pharmacology, and Molecular docking. METHODS: EOFHCB compositions were identified using GC-MS, and their targets were predicted using Swiss Target Prediction databases. The targets of anxiety disorders were obtained by GeneCards, DisGeNET, and OMIM databases. The STRING database was used to construct the protein-protein interaction networks, and the DAVID database was used to carry out GO enrichment and KEGG pathway enrichment analysis. The EOFHCB-components-targetspathways- anxiety disorders network was constructed by Cytoscape software (Version 3.10.0). Finally, the result was verified by molecular docking. RESULTS: 28 chemical components were identified by GC-MS, including 3-furanmethanol (28.43%), 2-methyl-1-butanol (27.13%), nerolidol (10.62%), and so on, which correspond to 241 potential targets. Several 2440 biological processes, 187 cellular compositions, and 311 molecular functions were enriched by GO enrichment analysis and 174 pathways by KEGG enrichment analysis. The key targets are PTGS 2, SRC, DRD 2, ESR 1, MAOB, and SLC6A4. The most important pathway is the neuroactive ligand-receptor interaction. CONCLUSION: EOFHCB exerts its therapeutic effects on anxiety disorders through multicomponents, multi-targets, and multi-pathways, which provided new ideas and methods for the in-depth research of aromatic Chinese medicine in the treatment of anxiety disorders.

4.
Molecules ; 29(13)2024 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-38999191

RESUMO

Organic pollutants were one of the main sources of environmental pollutants. The degradation of organic pollutants through photocatalytic technology was one of the effective solutions. By preparing zinc oxide(ZnO) nanowires modified with sodium-doped conjugated 2,4,6-triaminopyrimidin-g-C3N4 (NaTCN) heterojunction (ZnO/NaTCN), the photocatalytic performance of NaTCN modified with different ratios of ZnO was systematically studied. The photocatalytic performance was studied through the degradation performance of methyl blue (MB) dye. The results showed that 22.5 wt% ZnO/NaTCN had the best degradation effect on MB dye. The degradation rate of MB reached 98.54% in 70 min. After three cycles, it shows good cycling stability (degradation rate is 96.99%) for dye degradation. It was found that there are two types of active species: ·OH and h+, of which h+ is the main active species produced by photocatalytic degradation of dyes. The excellent degradation performance was attributed to the fact that ZnO facilitated the extraction and transport of photogenerated carriers. The doping of sodium facilitated charge transfer. The NaTCN conjugated system promoted the extraction and transfer of photogenerated carriers. It provided guidance for designing efficient composite catalysts for use in other renewable energy fields.

5.
Int Immunopharmacol ; 137: 112384, 2024 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-38878484

RESUMO

Selenium nanoparticles (SeNPs) enhance the immune response as adjuvants, increasing the efficacy of viral vaccines, including those for COVID-19. However, the efficiency of mucosal SeNPs in boosting vaccine-induced protective immunity against tuberculosis remains unclear. Therefore, this study aims to investigate whether the combination of SeNPs with the AH antigen (Ag85A-HspX) can boost respiratory mucosal immunity and thereby enhance the protective effects against tuberculosis. We synthesized SeNPs and assessed their impact on the immune response and protection against Mycobacterium bovis (M. bovis) as a mucosal adjuvant in mice, administered intranasally at a dose of 20 µg. SeNPs outperformed polyinosinic-polycytidylic acid (Poly IC) in stimulating the maturation of bone marrow-derived dendritic cells (BMDCs), which enhanced antigen presentation. SeNPs significantly activated and proliferated tissue-resident memory T cells (TRMs) and effector CD4+ T cells in the lungs. The vaccines elicited specific antibody responses in the respiratory tract and stimulated systemic Th1 and Th17 immune responses. Immunization with AH and SeNPs led to higher levels of mucosal secretory IgA in bronchoalveolar lavage fluid (BALF) and secretory IL-17 in splenocytes. Moreover, SeNPs immunized mice showed reduced M. bovis infection loads and inflammatory lesions in the lungs post-challenge. Notably, immunization with AH and SeNPs significantly reduced bacterial load in the lungs, achieving the lowest levels compared to all other tested groups. This study calls for pre-clinical investigation of AHB-SeNPs as an anti-bovine tuberculosis vaccine and for exploring its human vaccine potential, which is anticipated to aid in the development of innovative vaccines or adjuvants.


Assuntos
Adjuvantes Imunológicos , Antígenos de Bactérias , Imunidade nas Mucosas , Mycobacterium bovis , Nanopartículas , Selênio , Animais , Mycobacterium bovis/imunologia , Imunidade nas Mucosas/efeitos dos fármacos , Nanopartículas/administração & dosagem , Camundongos , Adjuvantes Imunológicos/administração & dosagem , Feminino , Antígenos de Bactérias/imunologia , Camundongos Endogâmicos C57BL , Tuberculose/imunologia , Tuberculose/prevenção & controle , Células Dendríticas/imunologia , Células Dendríticas/efeitos dos fármacos , Vacinas contra a Tuberculose/imunologia , Vacinas contra a Tuberculose/administração & dosagem , Pulmão/imunologia , Pulmão/microbiologia , Proteínas de Bactérias/imunologia
6.
J Hazard Mater ; 476: 134972, 2024 Jun 19.
Artigo em Inglês | MEDLINE | ID: mdl-38908173

RESUMO

Metal-based nanoparticles (MNPs) are increasingly being released into the marine environment, posing potential environmental risks. However, factors governing the environmental occurrence and distribution of MNPs in bays still lack a comprehensive understanding. Herein, we collected seawater and sediment samples from two adjacent bays (Daya Bay and Honghai Bay, which have similar water qualities), and determined the particle concentrations and sizes of multi-element MNPs (Ti-, Cu-, Zn-, Ag-, Mn-, Pb- and Cr-based NPs) via single particle inductively coupled plasma-mass spectrometry (spICP-MS). The internal circulation in Daya Bay has resulted in an even distribution of MNPs' particle concentrations and sizes in both seawater and sediments, while the terrestrial discharge in Honghai Bay has led to a gradient-decreasing trend in MNPs' concentrations from nearshore to offshore. Moreover, the relatively high abundance of MNPs in Honghai Bay has contributed to 2.35-fold higher environmental risks than Daya Bay. Overall, this study has provided solid evidence on the critical but overlooked factors that have shaped the occurrence and distribution of MNPs, providing new insights for risk management and emission regulation.

7.
Adv Mater ; : e2404626, 2024 Jun 02.
Artigo em Inglês | MEDLINE | ID: mdl-38825781

RESUMO

Van der Waals (vdW) integration enables clean contacts for low-dimensional electronic devices. The limitation remains, however, that an additional tunneling contact resistance occurs, owing to the inherent vdW gap between the metal and the semiconductor. Here we demonstrate from theoretical calculations that stronger non-covalent hydrogen-bonding interactions facilitate electron tunneling and significantly reduce the contact resistance, thus promising to break the limitations of the vdW contact. π-Plane hydrogen-bonding contacts in surface-engineered MXene/carbon nanotube metal/semiconductor heterojunctions are realized, and an anomalous temperature-dependent tunneling resistance is observed. Low-dimensional flexible thin-film transistors integrated by hydrogen-bonding contacts exhibit both excellent flexibility and carrier mobility orders of magnitude higher than their counterparts with vdW contacts. Our strategy demonstrates a scalable solution for realizing high-performance and low-power flexible electronics beyond vdW contacts. This article is protected by copyright. All rights reserved.

8.
Development ; 151(12)2024 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-38814747

RESUMO

The shoot apical meristem (SAM) gives rise to the aboveground organs of plants. The size of the SAM is relatively constant due to the balance between stem cell replenishment and cell recruitment into new organs. In angiosperms, the transcription factor WUSCHEL (WUS) promotes stem cell proliferation in the central zone of the SAM. WUS forms a negative feedback loop with a signaling pathway activated by CLAVATA3 (CLV3). In the periphery of the SAM, the ERECTA family receptors (ERfs) constrain WUS and CLV3 expression. Here, we show that four ligands of ERfs redundantly inhibit the expression of these two genes. Transcriptome analysis confirmed that WUS and CLV3 are the main targets of ERf signaling and uncovered new ones. Analysis of promoter reporters indicated that the WUS expression domain mostly overlaps with the CLV3 domain and does not shift along the apical-basal axis in clv3 mutants. Our three-dimensional mathematical model captured gene expression distributions at the single-cell level under various perturbed conditions. Based on our findings, CLV3 regulates cellular levels of WUS mostly through autocrine signaling, and ERfs regulate the spatial expression of WUS, preventing its encroachment into the peripheral zone.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Regulação da Expressão Gênica de Plantas , Proteínas de Homeodomínio , Meristema , Transdução de Sinais , Arabidopsis/genética , Arabidopsis/metabolismo , Arabidopsis/crescimento & desenvolvimento , Meristema/metabolismo , Meristema/genética , Proteínas de Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Transdução de Sinais/genética , Proteínas de Homeodomínio/metabolismo , Proteínas de Homeodomínio/genética , Receptores de Superfície Celular/metabolismo , Receptores de Superfície Celular/genética , Fatores de Transcrição/metabolismo , Fatores de Transcrição/genética , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Serina-Treonina Quinases/genética , Modelos Biológicos
9.
Molecules ; 29(9)2024 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-38731650

RESUMO

The present study investigates the chemical composition variances among Pinelliae Rhizoma, a widely used Chinese herbal medicine, and its common adulterants including Typhonium flagelliforme, Arisaema erubescens, and Pinellia pedatisecta. Utilizing the non-targeted metabolomics technique of employing UHPLC-Q-Orbitrap HRMS, this research aims to comprehensively delineate the metabolic profiles of Pinelliae Rhizoma and its adulterants. Multivariate statistical methods including PCA and OPLS-DA are employed for the identification of differential metabolites. Volcano plot analysis is utilized to discern upregulated and downregulated compounds. KEGG pathway analysis is conducted to elucidate the differences in metabolic pathways associated with these compounds, and significant pathway enrichment analysis is performed. A total of 769 compounds are identified through metabolomics analysis, with alkaloids being predominant, followed by lipids and lipid molecules. Significant differential metabolites were screened out based on VIP > 1 and p-value < 0.05 criteria, followed by KEGG enrichment analysis of these differential metabolites. Differential metabolites between Pinelliae Rhizoma and Typhonium flagelliforme, as well as between Pinelliae Rhizoma and Pinellia pedatisecta, are significantly enriched in the biosynthesis of amino acids and protein digestion and absorption pathways. Differential metabolites between Pinelliae Rhizoma and Arisaema erubescens are mainly enriched in tyrosine metabolism and phenylalanine metabolism pathways. These findings aim to provide valuable data support and theoretical references for further research on the pharmacological substances, resource development and utilization, and quality control of Pinelliae Rhizoma.


Assuntos
Metabolômica , Pinellia , Rizoma , Cromatografia Líquida de Alta Pressão/métodos , Metabolômica/métodos , Pinellia/metabolismo , Pinellia/química , Rizoma/metabolismo , Rizoma/química , Medicamentos de Ervas Chinesas/química , Medicamentos de Ervas Chinesas/metabolismo , Espectrometria de Massas/métodos , Contaminação de Medicamentos , Metaboloma , Redes e Vias Metabólicas
10.
Int J Gen Med ; 17: 1729-1738, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38711824

RESUMO

Objective: We evaluated the long-term safety and efficacy of thalidomide in the treatment of transfusion-dependent ß-thalassemia (TDT). Methods: Fifty patients with TDT were treated with thalidomide and followed-up for 5 years. Thalidomide at a 50 mg dose was administered once a day after dinner. The dose was increased to 150 mg/d after 3 d if well tolerated. After 1 year of treatment, the hemoglobin (Hb) level was stabilized at its maximum, and thalidomide was gradually reduced and maintained at the minimum dose. The hematological response, transfusion dependence, and haemolytic indicators were assessed. Results: At 9 month of follow-up, 38 (76%) patients achieved an excellent response, 1 (2%) a good response, 4(8%) a minor response, and 7(14%) did not show a response. The overall response rate was 86%. At 9 months, the Hb level increased from 79.0 ± 13.2 g/L at baseline to 99.0 ± 13.7g/L (P<0.001). Patients who achieved excellent response continued to show an increase in Hb levels during follow-up. At 48 months, the mean Hb level was 98.99 ± 10.3g/L; 21 patients (84.0%) became transfusion independent. Thalidomide was reduced and maintained to 25 mg/d in three of these patients. Moreover, five patients completed 60 months of follow-up, and with a mean Hb level of 99.8 ± 6.7g/L. During follow-up, grade 1-2 adverse drug reactions were noted; however, no grade 3 or higher adverse event was reported. However, no decrease in hemolytic indicators was observed. Conclusion: Thalidomide was well tolerated in the long term, while it significantly improved Hb levels and reduced the transfusion burden.

11.
Sci Rep ; 14(1): 10856, 2024 05 13.
Artigo em Inglês | MEDLINE | ID: mdl-38740857

RESUMO

Bitter gourd, being perishable, requires timely harvesting. Delayed harvesting can result in a substantial reduction in fruit quality. while premature harvesting leads to underdeveloped fruit and decreased yields, the continuous flowering pattern in bitter gourd underscores the significance of accurately assessing fruit growth and ensuring timely harvesting for subsequent fruit setting and development. The current reliance on the experience of production personnel represents a substantial inefficiency. We present an improved real-time instance segmentation model based on YOLOv5-seg. The utilization of dynamic snake convolution enables the extraction of morphological features from the curved and elongated structure of bitter gourd. Diverse branch blocks enhance feature space diversity without inflating model size and inference time, contributing to improved recognition of expansion stages during bitter gourd growth. Additionally, the introduction of Focal-EIOU loss accurately locates the boundary box and mask, addressing sample imbalances in the L2 stage. Experimental results showcase remarkable accuracy rates of 99.3%, 93.8%, and 98.3% for L1, L2, and L3 stages using mAP@0.5. In comparison, our model outperforms other case segmentation models, excelling in both detection accuracy and inference speed. The improved YOLOv5-seg model demonstrates strong performance in fine-grained recognition of bitter gourd during the expansion stage. It efficiently segments bitter gourd in real-time under varying lighting and occlusion conditions, providing crucial maturity information. This model offers reliable insights for agricultural workers, facilitating precise harvesting decisions.


Assuntos
Frutas , Frutas/crescimento & desenvolvimento , Lycium/crescimento & desenvolvimento , Algoritmos
12.
Front Cell Dev Biol ; 12: 1378035, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38770153

RESUMO

Stem cell spheroid is a promising graft substitute for bone tissue engineering. Spheroids obtained by 3D culture of STRO1+ Gingival Mesenchymal Stem Cells (sGMSCs) (sGMSC spheroids, GS) seldom express angiogenic factors, limiting their angiogenic differentiation in vivo. This study introduced a novel stem cell spheroid with osteogenic and angiogenic potential through 3D co-culture of sGMSCs and Human Umbilical Vein Endothelial Cells (HUVECs) (sGMSC/HUVEC spheroids, GHS). GHS with varying seeding ratios of sGMSCs to HUVECs (GHR) were developed. Cell fusion within the GHS system was observed via immunofluorescence. Calcein-AM/PI staining and chemiluminescence assay indicated cellular viability within the GHS. Furthermore, osteogenic and angiogenic markers, including ALP, OCN, RUNX2, CD31, and VEGFA, were quantified and compared with the control group comprising solely of sGMSCs (GS). Incorporating HUVECs into GHS extended cell viability and stability, initiated the expression of angiogenic factors CD31 and VEGFA, and upregulated the expression of osteogenic factors ALP, OCN, and RUNX2, especially when GHS with a GHR of 1:1. Taken together, GHS, derived from the 3D co-culture of sGMSCs and HUVECs, enhanced osteogenic and angiogenic capacities in vitro, extending the application of cell therapy in bone tissue engineering.

13.
Animals (Basel) ; 14(10)2024 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-38791682

RESUMO

Neurotrophin receptor B (NTRK2), also named TRKB, belongs to the neurotrophic factor family. Previous studies have shown that NTRK2 is associated with high fertility in mammals. However, the molecular mechanism and regulatory pathway of this neurotrophic factor remain unclear. In this study, NTRK2 overexpression and NTRK2-siRNA were constructed to detect the effects of NTRK2 on the proliferation and hormone secretion of the ovarian granulosa cells (GCs) of sheep. We successfully isolated follicular phase granulosa cells in vitro from the ovaries of sheep in simultaneous estrus, and the immunofluorescence results confirmed that NTRK2 was expressed in the collected cells. Subsequently, the effect of NTRK2 on the proliferation of sheep granulosa cells was examined via cell transfection experiments. The results showed that the expression of CDK4 and CyclinD2 was significantly increased after NTRK2 overexpression, while the opposite trend was observed after the inhibition of NTRK2 expression (p < 0.05). The EdU and CCK-8 assays showed that the proliferation rate of sheep GCs was significantly increased after NTRK2 overexpression, while the opposite trend was observed after the inhibition of NTRK2 expression (p < 0.05). Moreover, NTRK2 significantly increased the expression of steroidogenesis-related genes, including steroidogenic acute regulatory protein (STAR) and hydroxy-δ-5-steroid dehydrogenase (HSD3B1), and cytochrome P450 family 19 subfamily A member 1 (CYP19A1). The ELISA results showed that the secretion levels of E2 and P4 significantly increased after NTRK2 overexpression, while the opposite trend was observed after the inhibition of NTRK2 expression (p < 0.05). Previous studies had confirmed that NTRK2 gene belongs to the PI3K-AKT signaling pathway and participates in the signaling of this pathway. This was demonstrated by protein-protein interaction analysis and NTRK2 belongs to the PI3K-AKT pathway. The modification of PI3K and AKT, markers of the PI3K-AKT pathway, via phosphorylation was increased after NTRK2 overexpression in the sheep GCs, while the opposite trend was observed after the inhibition of NTRK2 expression (p < 0.05). Overall, these results suggest that the NTRK2 gene regulates the proliferation of GCs and the secretion of steroid hormones in sheep, and that it influences the phosphorylation level of the PI3K/AKT signaling pathway. These findings provided a theoretical basis and new perspectives for exploring the regulation of NTRK2 gene in the development of ovine follicles.

14.
Phys Med Biol ; 69(11)2024 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-38749463

RESUMO

Objective.This study aims to leverage a deep learning approach, specifically a deformable convolutional layer, for staging cervical cancer using multi-sequence MRI images. This is in response to the challenges doctors face in simultaneously identifying multiple sequences, a task that computer-aided diagnosis systems can potentially improve due to their vast information storage capabilities.Approach.To address the challenge of limited sample sizes, we introduce a sequence enhancement strategy to diversify samples and mitigate overfitting. We propose a novel deformable ConvLSTM module that integrates a deformable mechanism with ConvLSTM, enabling the model to adapt to data with varying structures. Furthermore, we introduce the deformable multi-sequence guidance model (DMGM) as an auxiliary diagnostic tool for cervical cancer staging.Main results.Through extensive testing, including comparative and ablation studies, we validate the effectiveness of the deformable ConvLSTM module and the DMGM. Our findings highlight the model's ability to adapt to the deformation mechanism and address the challenges in cervical cancer tumor staging, thereby overcoming the overfitting issue and ensuring the synchronization of asynchronous scan sequences. The research also utilized the multi-modal data from BraTS 2019 as an external test dataset to validate the effectiveness of the proposed methodology presented in this study.Significance.The DMGM represents the first deep learning model to analyze multiple MRI sequences for cervical cancer, demonstrating strong generalization capabilities and effective staging in small dataset scenarios. This has significant implications for both deep learning applications and medical diagnostics. The source code will be made available subsequently.


Assuntos
Processamento de Imagem Assistida por Computador , Imageamento por Ressonância Magnética , Estadiamento de Neoplasias , Neoplasias do Colo do Útero , Neoplasias do Colo do Útero/diagnóstico por imagem , Neoplasias do Colo do Útero/patologia , Humanos , Feminino , Imageamento por Ressonância Magnética/métodos , Processamento de Imagem Assistida por Computador/métodos , Aprendizado Profundo
15.
Biomed Mater ; 19(4)2024 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-38772383

RESUMO

The traditional chemotherapeutic agents' disadvantages such as high toxicity, untargeting and poor water solubility lead to disappointing chemotherapy effects, which restricts its clinical application. In this work, novel size-appropriate and glutathione (GSH)-responsive nano-hydrogels were successfully prepared via the active ester method between chitosan (containing -NH2) and cross-linker (containing NHS). Especially, the cross-linker was elaborately designed to possess a disulfide linkage (SS) as well as two terminal NHS groups, namely NHS-SS-NHS. These functionalities endowed chitosan-based cross-linked scaffolds with capabilities for drug loading and delivery, as well as a GSH-responsive mechanism for drug release. The prepared nano-hydrogels demonstrated excellent performance applicable morphology, excellent drug loading efficiency (∼22.5%), suitable size (∼100 nm) and long-term stability. The prepared nano-hydrogels released over 80% doxorubicin (DOX) after incubation in 10 mM GSH while a minimal DOX release less than 25% was tested in normal physiological buffer (pH = 7.4). The unloaded nano-hydrogels did not show any apparent cytotoxicity to A 549 cells. In contrast, DOX-loaded nano-hydrogels exhibited marked anti-tumor activity against A 549 cells, especially in high GSH environment. Finally, through fluorescent imaging and flow cytometry analysis, fluorescein isothiocyanate-labeled nano-hydrogels show obvious specific binding to the GSH high-expressing A549 cells and nonspecific binding to the GSH low-expressing A549 cells. Therefore, with this cross-linking approach, our present finding suggests that cross-linked chitosan nano-hydrogel drug carrier improves the anti-tumor effect of the A 549 cells and may serve as a potential injectable delivery carrier.


Assuntos
Antineoplásicos , Quitosana , Reagentes de Ligações Cruzadas , Doxorrubicina , Glutationa , Hidrogéis , Quitosana/química , Humanos , Doxorrubicina/farmacologia , Doxorrubicina/química , Glutationa/química , Glutationa/metabolismo , Hidrogéis/química , Reagentes de Ligações Cruzadas/química , Antineoplásicos/química , Antineoplásicos/farmacologia , Sobrevivência Celular/efeitos dos fármacos , Liberação Controlada de Fármacos , Linhagem Celular Tumoral , Células A549 , Portadores de Fármacos/química , Sistemas de Liberação de Medicamentos , Dissulfetos/química , Preparações de Ação Retardada/química
16.
Cell Rep ; 43(4): 114032, 2024 Apr 23.
Artigo em Inglês | MEDLINE | ID: mdl-38568805

RESUMO

N(6)-methyladenosine (m6A) critically regulates RNA dynamics in various biological processes. The m6A demethylase ALKBH5 promotes tumorigenesis of glioblastoma, while the intricate web that orchestrates its regulation remains enigmatic. Here, we discover that cell density affects ALKBH5 subcellular localization and m6A dynamics. Mechanistically, ALKBH5 is phosphorylated by the large tumor suppressor kinase 2 (LATS2), preventing its nuclear export and enhancing protein stability. Furthermore, phosphorylated ALKBH5 reciprocally erases m6A from LATS2 mRNA, thereby stabilizing this transcript. Unexpectedly, LATS2 depletion suppresses glioblastoma stem cell self-renewal independent of yes-associated protein activation. Additionally, deficiency in either LATS2 or ALKBH5 phosphorylation impedes tumor progression in mouse xenograft models. Moreover, high levels of LATS2 expression and ALKBH5 phosphorylation are associated with tumor malignancy in patients with gliomas. Collectively, our study unveils an oncogenic positive feedback loop between LATS2 and ALKBH5, revealing a non-canonical branch of the Hippo pathway for RNA processing and suggesting potential anti-cancer interventions.


Assuntos
Homólogo AlkB 5 da RNA Desmetilase , Carcinogênese , Retroalimentação Fisiológica , Proteínas Supressoras de Tumor , Proteínas Supressoras de Tumor/metabolismo , Homólogo AlkB 5 da RNA Desmetilase/genética , Homólogo AlkB 5 da RNA Desmetilase/metabolismo , Retroalimentação Fisiológica/fisiologia , Estabilidade Proteica , Fosforilação/genética , Glioblastoma/enzimologia , Glioblastoma/fisiopatologia , Humanos , Animais , Camundongos , Linhagem Celular Tumoral , Adenosina/análogos & derivados , Adenosina/metabolismo , Contagem de Células , Proteólise , Carcinogênese/genética , Carcinogênese/patologia
17.
J Assoc Res Otolaryngol ; 25(3): 259-275, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38622383

RESUMO

PURPOSE: Cisplatin is a low-cost clinical anti-tumor drug widely used to treat solid tumors. However, its use could damage cochlear hair cells, leading to irreversible hearing loss. Currently, there appears one drug approved in clinic only used for reducing ototoxicity associated with cisplatin in pediatric patients, which needs to further explore other candidate drugs. METHODS: Here, by screening 1967 FDA-approved drugs to protect cochlear hair cell line (HEI-OC1) from cisplatin damage, we found that Tedizolid Phosphate (Ted), a drug indicated for the treatment of acute infections, had the best protective effect. Further, we evaluated the protective effect of Ted against ototoxicity in mouse cochlear explants, zebrafish, and adult mice. The mechanism of action of Ted was further explored using RNA sequencing analysis and verified. Meanwhile, we also observed the effect of Ted on the anti-tumor effect of cisplatin. RESULTS: Ted had a strong protective effect on hair cell (HC) loss induced by cisplatin in zebrafish and mouse cochlear explants. In addition, when administered systemically, it protected mice from cisplatin-induced hearing loss. Moreover, antitumor studies showed that Ted had no effect on the antitumor activity of cisplatin both in vitro and in vivo. RNA sequencing analysis showed that the otoprotective effect of Ted was mainly achieved by inhibiting phosphorylation of ERK. Consistently, ERK activator aggravated the damage of cisplatin to HCs. CONCLUSION: Collectively, these results showed that FDA-approved Ted protected HCs from cisplatin-induced HC loss by inhibiting ERK phosphorylation, indicating its potential as a candidate for preventing cisplatin ototoxicity in clinical settings.


Assuntos
Antineoplásicos , Cisplatino , Perda Auditiva , Organofosfatos , Oxazóis , Peixe-Zebra , Animais , Cisplatino/toxicidade , Cisplatino/efeitos adversos , Camundongos , Perda Auditiva/prevenção & controle , Perda Auditiva/induzido quimicamente , Oxazóis/farmacologia , Organofosfatos/toxicidade , Antineoplásicos/toxicidade , United States Food and Drug Administration , Aprovação de Drogas , Células Ciliadas Auditivas/efeitos dos fármacos , Estados Unidos , Ototoxicidade/prevenção & controle , Ototoxicidade/etiologia , Humanos
18.
Chem Biodivers ; 21(6): e202400519, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38576052

RESUMO

One new highly degraded steroid, namely 21-nor-4-ene-chaxine A (1) furnishing a 5/6/5-tricyclic, along with one known related analogue (2), were isolated from the South China Sea sponge Spongia officinalis. Their structures including absolute configurations were established by extensive spectroscopic data analysis, TDDFT-ECD calculation, and comparison with the spectral data previously reported in the literature. Compound 1 represent the new member of incisterols family with a highly degradation in ring B. In vitro bioassays revealed compound 2 exhibited significant anti-microglial inflammatory effect on lipopolysaccharide (LPS)-induced inflammation in BV-2 microglial cells.


Assuntos
Anti-Inflamatórios , Lipopolissacarídeos , Poríferos , Esteroides , Animais , Poríferos/química , Esteroides/química , Esteroides/isolamento & purificação , Esteroides/farmacologia , Lipopolissacarídeos/farmacologia , Lipopolissacarídeos/antagonistas & inibidores , Camundongos , Anti-Inflamatórios/farmacologia , Anti-Inflamatórios/química , Anti-Inflamatórios/isolamento & purificação , China , Microglia/efeitos dos fármacos , Microglia/metabolismo , Microglia/citologia , Linhagem Celular , Conformação Molecular , Estrutura Molecular
19.
IEEE J Biomed Health Inform ; 28(7): 4062-4071, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38662561

RESUMO

In a clinical setting, the acquisition of certain medical image modality is often unavailable due to various considerations such as cost, radiation, etc. Therefore, unpaired cross-modality translation techniques, which involve training on the unpaired data and synthesizing the target modality with the guidance of the acquired source modality, are of great interest. Previous methods for synthesizing target medical images are to establish one-shot mapping through generative adversarial networks (GANs). As promising alternatives to GANs, diffusion models have recently received wide interests in generative tasks. In this paper, we propose a target-guided diffusion model (TGDM) for unpaired cross-modality medical image translation. For training, to encourage our diffusion model to learn more visual concepts, we adopted a perception prioritized weight scheme (P2W) to the training objectives. For sampling, a pre-trained classifier is adopted in the reverse process to relieve modality-specific remnants from source data. Experiments on both brain MRI-CT and prostate MRI-US datasets demonstrate that the proposed method achieves a visually realistic result that mimics a vivid anatomical section of the target organ. In addition, we have also conducted a subjective assessment based on the synthesized samples to further validate the clinical value of TGDM.


Assuntos
Encéfalo , Próstata , Humanos , Encéfalo/diagnóstico por imagem , Próstata/diagnóstico por imagem , Masculino , Imageamento por Ressonância Magnética/métodos , Processamento de Imagem Assistida por Computador/métodos , Tomografia Computadorizada por Raios X/métodos , Algoritmos , Imagem Multimodal/métodos
20.
Int Urol Nephrol ; 2024 Apr 26.
Artigo em Inglês | MEDLINE | ID: mdl-38668886

RESUMO

PURPOSE: The relationship between vitamin intake and cancer risk in the chronic kidney disease (CKD) population is unknown. For this reason, we investigated the relationship between dietary vitamin intake and cancer risk in CKD patients and looked for effective vitamin dietary patterns. METHODS: This study included 3518 CKD patients from 2007 to 2018 National Health and Nutrition Examination Survey database. All participants were categorized into four groups based on vitamin intake by K-mean clustering. The data were collected and analyzed from June 2023 to December 2023. RESULTS: A total of 3518 CKD patients with a mean age of (61.8 ± 16.3) years were included in the study. During a median follow-up of 7.3 years, 137 participants died of cancer. In the multivariate adjusted cox proportional hazards model for single vitamin intake, vitamin E Q4 intake (reference Q1) reduced cancer mortality (HR (95% CI) = 0.45 (0.24-0.87), P = 0.018). Further plotting of the restricted cubic spline curve revealed a linearly decreasing relationship between vitamin E intake and cancer mortality (Poverall = 0.010 Pnon-linear = 0.163). In the multivariate adjusted cox proportional hazards model for multivitamin co-intake, the vitamin C/K intake group reduced cancer mortality compared to the low vitamin intake group (HR (95% CI) = 0.42 (0.20-0.88), P = 0.022). CONCLUSION: Increased vitamin C intake was independently associated with reduced cancer risk in CKD patients, and a vitamin dietary pattern with high vitamin C/K intake was also effective in reducing cancer risk.

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