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1.
Proc Natl Acad Sci U S A ; 120(48): e2307389120, 2023 Nov 28.
Artículo en Inglés | MEDLINE | ID: mdl-37983515

RESUMEN

Granulocytes are indispensable for various immune responses. Unlike other cell types in the body, the nuclei of granulocytes, particularly neutrophils, are heavily segmented into multiple lobes. Although this distinct morphological feature has long been observed, the underlying mechanism remains incompletely characterized. In this study, we utilize cryo-electron tomography to examine the nuclei of mouse neutrophils, revealing the cytoplasmic enrichment of intermediate filaments on the concave regions of the nuclear envelope. Aided by expression profiling and immuno-electron microscopy, we then elucidate that the intermediate-filament protein vimentin is responsible for such perinuclear structures. Of importance, exogenously expressed vimentin in nonimmune cells is sufficient to form cytoplasmic filaments wrapping on the concave nuclear surface. Moreover, genetic deletion of the protein causes a significant reduction of the number of nuclear lobes in neutrophils and eosinophils, mimicking the hematological condition of the Pelger-Huët anomaly. These results have uncovered a new component establishing the nuclear segmentation of granulocytes.


Asunto(s)
Filamentos Intermedios , Neutrófilos , Animales , Ratones , Neutrófilos/metabolismo , Vimentina/metabolismo , Núcleo Celular , Eosinófilos
2.
Proc Natl Acad Sci U S A ; 120(12): e2221712120, 2023 03 21.
Artículo en Inglés | MEDLINE | ID: mdl-36917659

RESUMEN

Selective macroautophagy (hereafter referred to as autophagy) describes a process in which cytosolic material is engulfed in a double membrane organelle called an autophagosome. Autophagosomes are carriers responsible for delivering their content to a lytic compartment for destruction. The cargo can be of diverse origin, ranging from macromolecular complexes to protein aggregates, organelles, and even invading pathogens. Each cargo is unique in composition and size, presenting different challenges to autophagosome biogenesis. Among the largest cargoes targeted by the autophagy machinery are intracellular bacteria, which can, in the case of Salmonella, range from 2 to 5 µm in length and 0.5 to 1.5 µm in width. How phagophores form and expand on such a large cargo remains mechanistically unclear. Here, we used HeLa cells infected with an auxotrophic Salmonella to study the process of phagophore biogenesis using in situ correlative cryo-ET. We show that host cells generate multiple phagophores at the site of damaged Salmonella-containing vacuoles (SCVs). The observed double membrane structures range from disk-shaped to expanded cup-shaped phagophores, which have a thin intermembrane lumen with a dilating rim region and expand using the SCV, the outer membrane of Salmonella, or existing phagophores as templates. Phagophore rims establish different forms of contact with the endoplasmic reticulum (ER) via structurally distinct molecular entities for membrane formation and expansion. Early omegasomes correlated with the marker Double-FYVE domain-Containing Protein 1 (DFCP1) are observed in close association with the ER without apparent membrane continuity. Our study provides insights into the formation of phagophores around one of the largest selective cargoes.


Asunto(s)
Autofagosomas , Macroautofagia , Humanos , Autofagosomas/metabolismo , Autofagia , Retículo Endoplásmico/metabolismo , Células HeLa
3.
Biol Cell ; : e2400064, 2024 Jul 19.
Artículo en Inglés | MEDLINE | ID: mdl-39031999

RESUMEN

BACKGROUND INFORMATION: Microtubules serve as integral components in cellular operations such as cell division, intracellular trafficking, and cellular architecture. Composed of tubulin protein subunits, these hollow tubular structures have been increasingly elucidated through advanced cryo-electron microscopy (Cryo-EM), which has unveiled the presence of microtubule inner proteins (MIPs) within the microtubular lumen. RESULTS: In the present investigation, we employ a synergistic approach incorporating high-pressure freezing, cryo-focused ion beam milling, and Cryo-electron tomography (Cryo-ET) to interrogate the in situ architecture of microtubules in Caenorhabditis elegans larvae. Our Cryo-ET assessments across neuronal cilia and diverse tissue types consistently demonstrate the formation of annular configurations within the microtubular lumen. CONCLUSIONS: In concert with recently characterized MIPs, our in situ observations within a living organism corroborate the hypothesis that intricate luminal assemblages exist within microtubule scaffolds. These findings necessitate further exploration into the molecular constituents and functional ramifications of these internal microtubular configurations in both cellular physiology and pathophysiology.

4.
Nature ; 567(7748): 409-413, 2019 03.
Artículo en Inglés | MEDLINE | ID: mdl-30867599

RESUMEN

Chromatin remodellers include diverse enzymes with distinct biological functions, but nucleosome-sliding activity appears to be a common theme1,2. Among the remodelling enzymes, Snf2 serves as the prototype to study the action of this protein family. Snf2 and related enzymes share two conserved RecA-like lobes3, which by themselves are able to couple ATP hydrolysis to chromatin remodelling. The mechanism by which these enzymes couple ATP hydrolysis to translocate the nucleosome along the DNA remains unclear2,4-8. Here we report the structures of Saccharomyces cerevisiae Snf2 bound to the nucleosome in the presence of ADP and ADP-BeFx. Snf2 in the ADP-bound state adopts an open conformation similar to that in the apo state, and induces a one-base-pair DNA bulge at superhelix location 2 (SHL2), with the tracking strand showing greater distortion than the guide strand. The DNA distortion propagates to the proximal end, leading to staggered translocation of the two strands. The binding of ADP-BeFx triggers a closed conformation of the enzyme, resetting the nucleosome to a relaxed state. Snf2 shows altered interactions with the DNA in different nucleotide states, providing the structural basis for DNA translocation. Together, our findings suggest a fundamental mechanism for the DNA translocation that underlies chromatin remodelling.


Asunto(s)
Adenosina Trifosfatasas/metabolismo , Ensamble y Desensamble de Cromatina , Cromatina/genética , Cromatina/metabolismo , ADN/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae , Factores de Transcripción/metabolismo , Adenosina Difosfato/química , Adenosina Difosfato/metabolismo , Adenosina Trifosfatasas/química , Apoproteínas/química , Apoproteínas/metabolismo , Transporte Biológico , Cromatina/química , ADN/química , ADN/genética , Transferencia Resonante de Energía de Fluorescencia , Modelos Moleculares , Nucleosomas/química , Nucleosomas/metabolismo , Nucleótidos/química , Nucleótidos/metabolismo , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/química , Factores de Transcripción/química
5.
Proc Natl Acad Sci U S A ; 119(24): e2122249119, 2022 06 14.
Artículo en Inglés | MEDLINE | ID: mdl-35666862

RESUMEN

Microvilli are actin-bundle-supported membrane protrusions essential for absorption, secretion, and sensation. Microvilli defects cause gastrointestinal disorders; however, mechanisms controlling microvilli formation and organization remain unresolved. Here, we study microvilli by vitrifying the Caenorhabditis elegans larvae and mouse intestinal tissues with high-pressure freezing, thinning them with cryo-focused ion-beam milling, followed by cryo-electron tomography and subtomogram averaging. We find that many radial nanometer bristles referred to as nanobristles project from the lateral surface of nematode and mouse microvilli. The C. elegans nanobristles are 37.5 nm long and 4.5 nm wide. Nanobristle formation requires a protocadherin family protein, CDH-8, in C. elegans. The loss of nanobristles in cdh-8 mutants slows down animal growth and ectopically increases the number of Y-shaped microvilli, the putative intermediate structures if microvilli split from tips. Our results reveal a potential role of nanobristles in separating microvilli and suggest that microvilli division may help generate nascent microvilli with uniformity.


Asunto(s)
Caenorhabditis elegans , Tomografía con Microscopio Electrónico , Animales , Caenorhabditis elegans/metabolismo , Microscopía por Crioelectrón/métodos , Tomografía con Microscopio Electrónico/métodos , Congelación , Ratones , Microvellosidades/metabolismo
6.
Plant Cell Physiol ; 2024 Feb 19.
Artículo en Inglés | MEDLINE | ID: mdl-38372617

RESUMEN

The polyhydroxylated steroid phytohormone brassinosteroids (BRs) control many aspects of plant growth, development and responses to environmental changes. Plasma membrane (PM) H+-ATPase, the well-known PM proton pump, is a central regulator in plant physiology, which mediates not only plant growth and development, but also adaptation to stresses. Recent studies highlight that PM H+-ATPase is at least partly regulated via the BR signaling. Firstly, the BR cell surface receptor BRASSINOSTEROID-INSENSITIVE 1 (BRI1) and multiple key components of BR signaling directly or indirectly influence PM H+-ATPase activity. Secondly, the SMALL AUXIN UP RNA (SAUR) gene family physically interacts with BRI1 to enhance organ development of Arabidopsis by activating PM H+-ATPase. Thirdly, RNA-sequencing (RNA-seq) assays showed that the expression of some SAUR genes is upregulated under the light or sucrose conditions, which is related to the phosphorylation state of the penultimate residue of PM H+-ATPase in a time-course manner. In this review, we describe the structural and functional features of PM H+-ATPase, and summarize recent progress toward understanding the regulatory mechanism of PM H+-ATPase by BRs, and briefly introduce how PM H+-ATPase activity is modulated by its own biterminal regions and the post-translational modifications.

7.
Mol Carcinog ; 63(2): 238-252, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-37861358

RESUMEN

The curative treatment options for papillary thyroid cancer (PTC) encompass surgical intervention, radioactive iodine administration, and chemotherapy. However, the challenges of radioiodine (RAI) resistance, metastasis, and chemotherapy resistance remain inadequately addressed. The objective of this study was to investigate the protective role of hypoxia-inducible factor-1α (HIF-1α) in 131 I-resistant cells and a xenograft model under hypoxic conditions, as well as to explore potential mechanisms. The effects of HIF-1α on 131 I-resistant BCPAP and TPC-1 cells, as well as the xenograft model, were assessed in this study. Cell viability, migration, invasion, and apoptosis rates were measured using Cell Counting Kit-8, wound-healing, Transwell, and flow cytometry assays. Additionally, the expressions of Ki67, matrix metalloproteinase-9 (MMP-9), and pyruvate kinase M2 (PKM2) were examined using immunofluorescence or immunohistochemistry assays. Sodium iodide symporter and PKM2/NF-κBp65 relative protein levels were detected by western blot analysis. The findings of our study indicate that siHIF-1α effectively inhibits cell proliferation, cell migration, and invasion in 131 I-resistant cells under hypoxic conditions. Additionally, the treatment of siHIF-1α leads to alterations in the relative protein levels of Ki67, MMP-9, PKM2, and PKM2/NF-κBp65, both in vivo and in vitro. Notably, the effects of siHIF-1α are modified when DASA-58, an activator of PKM2, is administered. These results collectively demonstrate that siHIF-1α reduces cell viability in PTC cells and rat models, while also mediating the nuclear factor-κB (NF-κB)/PKM2 signaling pathway. Our findings provide a new rationale for further academic and clinical research on RAI-resistant PTC.


Asunto(s)
FN-kappa B , Neoplasias de la Tiroides , Humanos , Ratas , Animales , FN-kappa B/metabolismo , Radioisótopos de Yodo , Cáncer Papilar Tiroideo/radioterapia , Metaloproteinasa 9 de la Matriz/metabolismo , Supervivencia Celular , Antígeno Ki-67/metabolismo , Neoplasias de la Tiroides/radioterapia , Transducción de Señal , Hipoxia , Hipoxia de la Célula , Subunidad alfa del Factor 1 Inducible por Hipoxia/metabolismo , Línea Celular Tumoral
8.
Mol Cell Biochem ; 479(3): 653-664, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-37155089

RESUMEN

Pleckstrin homeolike domain, family A, member 1 (PHLDA1) is a multifunctional protein that plays diverse roles in A variety of biological processes, including cell death, and hence its altered expression has been found in different types of cancer. Although studies have shown a regulatory relationship between p53 and PHLDA1, the molecular mechanism is still unclear. Especially, the role of PHLDA1 in the process of apoptosis is still controversial. In this study, we found that the expression of PHLDA1 in human cervical cancer cell lines was correlated with the up-expression of p53 after treatment with apoptosis-inducing factors. Subsequently, the binding site and the binding effect of p53 on the promoter region of PHLDA1 were verified by our bioinformatics data analysis and luciferase reporter assay. Indeed, we used CRISPR-Cas9 to knockout the p53 gene in HeLa cells and further confirmed that p53 can bind to the promoter region of PHLDA1 gene, and then directly regulate the expression of PHLDA1 by recruiting P300 and CBP to change the acetylation and methylation levels in the promoter region. Finally, a series of gain-of-function experiments further confirmed that p53 re-expression in HeLap53-/- cell can up-regulate the reduction of PHLDA1 caused by p53 knockout, and affect cell apoptosis and proliferation. Our study is the first to explore the regulatory mechanism of p53 on PHLDA1 by using the p53 gene knockout cell model, which further proves that PHLDA1 is a target-gene in p53-mediated apoptosis, and reveals the important role of PHLDA1 in cell fate determination.


Asunto(s)
Factores de Transcripción , Proteína p53 Supresora de Tumor , Humanos , Apoptosis , Células HeLa , Factores de Transcripción/metabolismo , Proteína p53 Supresora de Tumor/genética
9.
Luminescence ; 39(8): e4843, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-39129388

RESUMEN

Photoelectric functional materials with electrochemical reversible activity and fluorescence intensities have attracted significant interest due to their wide range of applications in optoelectronic devices. In this work, a series of photoresponsive and electroactive monomers based on thieno[3.4-c]pyrrole-4,6-dione (TPD) are synthesized and characterized. They possess planar geometry with smaller dihedral angles owing to the existence of a noncovalent conformation lock coming from the S atoms and the O atoms. Crystallographic, spectroscopic, and computational results reveal that the introduction of the TPD unit can endow the monomers with aggregation-induced emission (AIE), reduced energy levels, and increased electrochemical activity. The monomers were successfully polymerized through the electrochemical method, and the corresponding polymers displayed reversible electrochemical activity and stability. Moreover, polymer films based on 3,3-dimethyl-3,4-dihydro-2H-thieno[3,4-b][1,4]dioxepine (ProE)-TPD have electrochromic properties in the near-infrared field with a high value of optical contrast ratio (∆T) of 27.1% at 1000 nm.


Asunto(s)
Técnicas Electroquímicas , Polimerizacion , Pirroles , Pirroles/química , Pirroles/síntesis química , Estructura Molecular , Polímeros/química , Polímeros/síntesis química
10.
Nature ; 544(7651): 440-445, 2017 04 27.
Artículo en Inglés | MEDLINE | ID: mdl-28424519

RESUMEN

Chromatin remodellers are helicase-like, ATP-dependent enzymes that alter chromatin structure and nucleosome positions to allow regulatory proteins access to DNA. Here we report the cryo-electron microscopy structure of chromatin remodeller Switch/sucrose non-fermentable (SWI2/SNF2) from Saccharomyces cerevisiae bound to the nucleosome. The structure shows that the two core domains of Snf2 are realigned upon nucleosome binding, suggesting activation of the enzyme. The core domains contact each other through two induced Brace helices, which are crucial for coupling ATP hydrolysis to chromatin remodelling. Snf2 binds to the phosphate backbones of one DNA gyre of the nucleosome mainly through its helicase motifs within the major domain cleft, suggesting a conserved mechanism of substrate engagement across different remodellers. Snf2 contacts the second DNA gyre via a positively charged surface, providing a mechanism to anchor the remodeller at a fixed position of the nucleosome. Snf2 locally deforms nucleosomal DNA at the site of binding, priming the substrate for the remodelling reaction. Together, these findings provide mechanistic insights into chromatin remodelling.


Asunto(s)
Adenosina Trifosfatasas/química , Adenosina Trifosfatasas/metabolismo , Ensamble y Desensamble de Cromatina , Nucleosomas/química , Nucleosomas/metabolismo , Proteínas de Saccharomyces cerevisiae/química , Proteínas de Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/química , Factores de Transcripción/química , Factores de Transcripción/metabolismo , Adenosina Trifosfatasas/ultraestructura , Secuencia de Aminoácidos , Sitios de Unión , Microscopía por Crioelectrón , ADN/química , ADN/metabolismo , Histonas/química , Histonas/metabolismo , Modelos Moleculares , Nucleosomas/ultraestructura , Unión Proteica , Saccharomyces cerevisiae/enzimología , Saccharomyces cerevisiae/ultraestructura , Proteínas de Saccharomyces cerevisiae/ultraestructura , Factores de Transcripción/ultraestructura
11.
Bioprocess Biosyst Eng ; 46(11): 1639-1650, 2023 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-37733076

RESUMEN

With potent herbicidal activity, biocatalysis synthesis of L-glufosinate has drawn attention. In present research, NAP-Das2.3, a deacetylase capable of stereoselectively resolving N-acetyl-L-glufosinate to L-glufosinate mined from Arenimonas malthae, was heterologously expressed and characterized. In Escherichia coli, NAP-Das2.3 activity only reached 0.25 U/L due to the formation of inclusive bodies. Efficient soluble expression of NAP-Das2.3 was achieved in Pichia pastoris. In shake flask and 5 L bioreactor fermentation, NAP-Das2.3 activity by recombinant P. pastoris reached 107.39 U/L and 1287.52 U/L, respectively. The optimum temperature and pH for N-acetyl-glufosinate hydrolysis by NAP-Das2.3 were 45 °C and pH 8.0, respectively. The Km and Vmax of NAP-Das2.3 towards N-acetyl-glufosinate were 25.32 mM and 19.23 µmol mg-1 min-1, respectively. Within 90 min, 92.71% of L-enantiomer in 100 mM racemic N-acetyl-glufosinate was converted by NAP-Das2.3. L-glufosinate with high optical purity (e.e.P above 99.9%) was obtained. Therefore, the recombinant NAP-Das2.3 might be an alternative for L-glufosinate biosynthesis.


Asunto(s)
Reactores Biológicos , Pichia , Proteínas Recombinantes/química , Pichia/genética , Pichia/metabolismo , Fermentación
12.
Langmuir ; 35(21): 7018-7025, 2019 05 28.
Artículo en Inglés | MEDLINE | ID: mdl-31066285

RESUMEN

There is a growing interest in the use of hybrid liposomes for various biochemical and biomedical applications. In this study, we report the first preparation and characterization of a class of TiO2-reinforced liposomes by a one-step assembly approach. The amphiphilic natural structure of lipids is exploited to localize a hydrophobic molecule, namely, precursor tetrabutyl titanate (TBOT), in the mid-plane of the liposomal bilayer assemblies in the aqueous phase. In situ TiO2 nanoshell formation is driven by subsequent interfacial hydrolysis of TBOT and the ensuing condensation within the hydrophobic interstices of the lipid bilayer. The core-shell structure, like cell and wall, is demonstrated by means of scanning electron microscopy and transmission electron microscopy images, and the formation of the TiO2 shell is confirmed using energy-dispersive X-ray spectroscopy, thermogravimetric analysis, and differential scanning calorimetry. To study the structural evolution of the hybrid liposomes during titania formation, fluorescence probe technique and surface pressure versus molecular area (π- A) isotherms are designed. The results demonstrate that the incorporation of TBOT into the mid-membrane of the lipid and titania in the core of the membrane strengthened the assembly of the lipid bilayer. We further demonstrate that titania shell improved the stability and release property of liposomes. We expect that the reported new TiO2-coated liposomes by co-assembly will be valuable in designing hybrid liposomes, exhibiting integrative capacity for drug encapsulation, compartment reaction, and photocatalysis.


Asunto(s)
Membrana Dobles de Lípidos/química , Nanoestructuras , Titanio/química , Interacciones Hidrofóbicas e Hidrofílicas , Liposomas , Microscopía Electrónica de Rastreo , Nanoestructuras/química , Nanoestructuras/ultraestructura , Espectrometría por Rayos X
13.
J Struct Biol ; 195(3): 325-336, 2016 09.
Artículo en Inglés | MEDLINE | ID: mdl-27424268

RESUMEN

Particle picking is a time-consuming step in single-particle analysis and often requires significant interventions from users, which has become a bottleneck for future automated electron cryo-microscopy (cryo-EM). Here we report a deep learning framework, called DeepPicker, to address this problem and fill the current gaps toward a fully automated cryo-EM pipeline. DeepPicker employs a novel cross-molecule training strategy to capture common features of particles from previously-analyzed micrographs, and thus does not require any human intervention during particle picking. Tests on the recently-published cryo-EM data of three complexes have demonstrated that our deep learning based scheme can successfully accomplish the human-level particle picking process and identify a sufficient number of particles that are comparable to those picked manually by human experts. These results indicate that DeepPicker can provide a practically useful tool to significantly reduce the time and manual effort spent in single-particle analysis and thus greatly facilitate high-resolution cryo-EM structure determination. DeepPicker is released as an open-source program, which can be downloaded from https://github.com/nejyeah/DeepPicker-python.


Asunto(s)
Microscopía por Crioelectrón/métodos , Imagenología Tridimensional/métodos , Programas Informáticos , Algoritmos , Secretasas de la Proteína Precursora del Amiloide/química , Secretasas de la Proteína Precursora del Amiloide/ultraestructura , Interpretación Estadística de Datos , Aprendizaje Automático , Modelos Moleculares , Canales Catiónicos TRPV/química , Canales Catiónicos TRPV/ultraestructura
14.
Vasa ; 45(4): 317-24, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-27428501

RESUMEN

BACKGROUND: External counterpulsation therapy enhances blood flow and was shown to improve endothelial function and quality of life in coronary artery disease patients. However, high pressures of up to 300 mmHg may lead to malperfusion of the ischaemic limb. To improve the clinical outcome of patients with peripheral artery disease (PAD), we adjusted external counterpulsation and developed a novel non-invasive approach termed individual shear rate therapy (ISRT). PATIENTS AND METHODS: In the present study, 14 patients with a Fontaine stage IIb and femoral-popliteal PAD underwent 30 hours of ISRT over 5 weeks. For ISRT, individual treatment pressures that do not exceed 160 mmHg were assessed by Doppler flow parameters during counterpulsation (individual shear rate diagnosis) in order to enhance and maximise peripheral perfusion. The study aimed to enhance peripheral perfusion and evaluate the primary clinical endpoint endothelial function, as well as to perform preliminary analysis of the ankle brachial index (ABI) and walking distance. RESULTS: Doppler flow measurements in the lower limb (ankle) validated that maximum blood flow velocity during systole and acceleration doubled during ISRT. Study results demonstrated that long-term ISRT significantly increased flow-mediated dilation (FMD) in the brachial artery (0.13+/- 0.09 mm to 0.38+/- 0.05 mm; p < 0.05), while nitromediated dilation (0.36+/- 0.10 mm to 0.45+/- 0.08 mm) remained and common femoral artery FMD did not reach statistical significance (0.38+/- 0.08 mm to 0.67+/- 0.19 mm; p<0.05). Initial claudication distance considerably improved for all patients after 30 hours of ISRT (92.6 +/- 8.2 metres to 280+/- 101.3 metres, p<0.05), just like the absolute claudication distance, which showed a more than 2.5-fold increase (167.8+/- 18.1 metres to 446.7+/- 133.3 metres; p<0.05). The ABI did not improve (0.58+/- 0.03 to 0.65+/- 0.04). CONCLUSIONS: Our data demonstrate that long-term ISRT is a potential novel non-invasive treatment to improve endothelial function and absolute pain-free walking distance for PAD patients.


Asunto(s)
Velocidad del Flujo Sanguíneo/fisiología , Endotelio Vascular/fisiopatología , Aparatos de Compresión Neumática Intermitente , Enfermedad Arterial Periférica/terapia , Anciano , Anciano de 80 o más Años , Arteria Braquial/diagnóstico por imagen , Femenino , Humanos , Masculino , Persona de Mediana Edad , Enfermedad Arterial Periférica/fisiopatología , Ultrasonografía Doppler
15.
Adv Healthc Mater ; 13(20): e2400109, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-38676445

RESUMEN

Proteolysis targeting chimeras (PROTACs) technology is rapidly developed as a novel and selective medicinal strategy for the degradation of cellular proteins in cancer therapy. However, the applications of PROTACs as heterobifunctional molecules are largely limited by high molecular weight, low bioavailability, poor permeability, insufficient targeting, and low efficacy in vivo. Herein, self-assembling micelles of FA-PEG-PROTAC are designed for cancer cell selective targeting and reductive-response proteolysis in tumor-bearing mice. FA-PEG-PROTAC is prepared by conjugating folic acid (FA)-PEG with EGFR-targeting PROTAC via a disulfide bond. The FA-PEG-PROTAC micelles, formed by self-assembling, are demonstrated to significantly improve tumor targeting efficacy and exhibit excellent anti-tumor efficacy in the mouse xenograft model compared to the traditional PROTACs. The strategy of applying self-assembled FA-PEG-PROTAC micelles in tumor therapy can not only improve targeted proteolysis efficiency but also broaden applications in the development of PROTAC-based drugs.


Asunto(s)
Ácido Fólico , Micelas , Polietilenglicoles , Proteolisis , Animales , Ácido Fólico/química , Ácido Fólico/análogos & derivados , Polietilenglicoles/química , Proteolisis/efectos de los fármacos , Humanos , Ratones , Línea Celular Tumoral , Ratones Desnudos , Ensayos Antitumor por Modelo de Xenoinjerto , Ratones Endogámicos BALB C , Receptores ErbB/metabolismo , Neoplasias/tratamiento farmacológico , Neoplasias/metabolismo , Sistemas de Liberación de Medicamentos/métodos
16.
J Ethnopharmacol ; 334: 118506, 2024 Nov 15.
Artículo en Inglés | MEDLINE | ID: mdl-38964625

RESUMEN

ETHNIC PHARMACOLOGICAL RELEVANCE: Panax ginseng is a traditional Chinese herbal medicine used to treat cardiovascular diseases (CVDs), and it is still widely used to improve the clinical symptoms of various CVDs. However, there is currently a lack of summary and analysis on the mechanism of Panax ginseng exerts its cardiovascular protective effects. This article provides a review of in vivo and in vitro pharmacological studies on Panax ginseng and its active ingredients in reducing CVDs damage. AIM OF THIS REVIEW: This review summarized the latest literature on Panax ginseng and its active ingredients in CVDs research, aiming to have a comprehensive and in-depth understanding of the cardiovascular protection mechanism of Panax ginseng, and to provide new ideas for the treatment of CVDs, as well as to optimize the clinical application of Panax ginseng. METHODS: Enrichment of pathways and biological terms using the traditional Chinese medicine molecular mechanism bioinformatics analysis tool (BATMAN-TCM). The literature search is based on electronic databases such as PubMed, ScienceDirect, Scopus, CNKI, with a search period of 2002-2023. The search terms include Panax ginseng, Panax ginseng ingredients, ginsenosides, ginseng polysaccharides, ginseng glycoproteins, ginseng volatile oil, CVDs, heart, and cardiac. RESULTS: 132 articles were ultimately included in the review. The ingredients in Panax ginseng that manifested cardiovascular protective effects are mainly ginsenosides (especially ginsenoside Rb1). Ginsenosides protected against CVDs such as ischemic reperfusion injury, atherosclerosis and heart failure mainly through improving energy metabolism, inhibiting hyper-autophagy, antioxidant, anti-inflammatory and promoting secretion of exosomes. CONCLUSION: Panax ginseng and its active ingredients have a particularly prominent effect on improving myocardial energy metabolism remodeling in protecting against CVDs. The AMPK and PPAR signaling pathways are the key targets through which Panax ginseng produces multiple mechanisms of cardiovascular protection. Extracellular vesicles and nanoparticles as carriers are potential delivery ways for optimizing the bioavailability of Panax ginseng and its active ingredients.


Asunto(s)
Enfermedades Cardiovasculares , Panax , Panax/química , Humanos , Enfermedades Cardiovasculares/tratamiento farmacológico , Enfermedades Cardiovasculares/prevención & control , Animales , Ginsenósidos/farmacología , Ginsenósidos/química , Medicamentos Herbarios Chinos/farmacología , Medicamentos Herbarios Chinos/uso terapéutico , Medicamentos Herbarios Chinos/química , Cardiotónicos/farmacología , Cardiotónicos/uso terapéutico , Medicina Tradicional China/métodos
17.
Heliyon ; 10(4): e25181, 2024 Feb 29.
Artículo en Inglés | MEDLINE | ID: mdl-38370208

RESUMEN

Objective: Meta-analysis was used to evaluate the clinical efficacy of auricular acupressure in the treatment of allergic rhinitis. Methods: Randomised controlled trials (RCTS) on the treatment of allergic rhinitis with ear acupuncture were searched by computer in PubMed, Cochrane Library, Embase、Web of Science、China National Knowledge Infrastructure (CNKI), Wanfang Database (Wanfang), VIP database, and China Biomedical Literature Service System (CBM). The search time was from the establishment of the database to September 18, 2022. Meta-analysis was performed using RevMan 5.4 software. Results: A total of 15 papers with 1002 patients were included in the final study. ①Clinical efficiency: The clinical efficiency of ear acupuncture combined with control group was higher than that of control group, and the difference was statistically significant (P < 0.00001); ② Nasal symptom score: the effect of ear acupuncture combined with control group on allergic rhinitis on nasal symptoms was more obvious than that of control group, and the difference was statistically significant (P = 0.004); ③ Nasal itching symptom score: the efficacy of ear acupuncture combined with control group on allergic rhinitis on nasal itching symptom was significantly higher than that of control group, and the difference was statistically significant (P = 0.01). ④Sneeze symptom score: the effect of ear acupuncture combined with control group on allergic rhinitis on nasal itching symptom was more effective than that of control group, and the difference was statistically significant (P < 0.00001); ⑤Score of runny nose symptom: the effect of ear acupuncture combined with control group on allergic rhinitis on runny nose symptom was more obvious than that of control group, the difference was statistically significant (P = 0.004); ⑥Nasal congestion symptom scores: The effect of ear acupuncture combined with control group on allergic rhinitis on nasal congestion symptom was more obvious than that of control group, and the difference was statistically significant (P = 0.003). Conclusion: Ear acupuncture as an adjunctive therapy of allergic rhinitis can achieve better clinical efficacy.

18.
Plant Cell Physiol ; 54(12): 2020-33, 2013 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-24092882

RESUMEN

Abiotic stresses disrupt protein folding and induce endoplasmic reticulum (ER) stress, which in turn activates the unfolded protein response (UPR) to aid in the refolding or degradation of misfolded proteins. The phytohormone ABA regulates many aspects of plant development and plays a central role in the stress response; however, the role of ABA in transducing stress signals to activate the UPR has not been recognized. In this study, a gene encoding the maize ortholog of AtbZIP17, a transmembrane transcription factor functioning as an ER stress transducer, was identified from the MaizeGDB database, and designated ZmbZIP17. ZmbZIP17 was induced by both ABA and ER stress-eliciting agents such as dithiotreitol (DTT) and tunicamycin (TM). Transiently expressed yellow fluorescent protein (YFP)-ZmbZIP17 co-localized with the ER marker HDEL-mCherry under control conditions, but partially translocated into the nucleus upon TM treatment or removal of the transmembrane domain. TM-induced processing of ZmbZIP17 was confirmed by Western blot analysis. When overexpressed in Arabidopsis, ZmbZIP17 triggered ER stress response gene expression and tolerance to DTT and TM, elevated ABA-responsive gene expression and ABA sensitivity both pre- and post-germination. Additionally, ABA was found to induce ER stress response gene expression, alone or synergistically with ZmbZIP17, in the absence of DTT or TM; while ZmbZIP17 was capable of interacting with ABA-responsive cis-elements (ABREs) that exist in promoters of known ABA-responsive genes. Together, our results reveal a direct link between ER stress and ABA signaling pathways involving the ZmbZIP17 transcription factor.


Asunto(s)
Ácido Abscísico/farmacología , Estrés del Retículo Endoplásmico/efectos de los fármacos , Proteínas de Plantas/metabolismo , Factores de Transcripción/metabolismo , Zea mays/efectos de los fármacos , Zea mays/metabolismo , Ditiotreitol/farmacología , Proteínas de Plantas/genética , Factores de Transcripción/genética , Tunicamicina/farmacología
19.
Circ Res ; 109(5): 524-33, 2011 Aug 19.
Artículo en Inglés | MEDLINE | ID: mdl-21719759

RESUMEN

RATIONALE: Positive outward remodeling of pre-existing collateral arteries into functional conductance arteries, arteriogenesis, is a major endogenous rescue mechanism to prevent cardiovascular ischemia. Collateral arterial growth is accompanied by expression of kinin precursor. However, the role of kinin signaling via the kinin receptors (B1R and B2R) in arteriogenesis is unclear. OBJECTIVE: The purpose of this study was to elucidate the functional role and mechanism of bradykinin receptor signaling in arteriogenesis. METHODS AND RESULTS: Bradykinin receptors positively affected arteriogenesis, with the contribution of B1R being more pronounced than B2R. In mice, arteriogenesis upon femoral artery occlusion was significantly reduced in B1R mutant mice as evidenced by reduced microspheres and laser Doppler flow perfusion measurements. Transplantation of wild-type bone marrow cells into irradiated B1R mutant mice restored arteriogenesis, whereas bone marrow chimeric mice generated by reconstituting wild-type mice with B1R mutant bone marrow showed reduced arteriogenesis after femoral artery occlusion. In the rat brain 3-vessel occlusion arteriogenesis model, pharmacological blockade of B1R inhibited arteriogenesis and stimulation of B1R enhanced arteriogenesis. In the rat, femoral artery ligation combined with arterial venous shunt model resulted in flow-driven arteriogenesis, and treatment with B1R antagonist R715 decreased vascular remodeling and leukocyte invasion (monocytes) into the perivascular tissue. In monocyte migration assays, in vitro B1R agonists enhanced migration of monocytes. CONCLUSIONS: Kinin receptors act as positive modulators of arteriogenesis in mice and rats. B1R can be blocked or therapeutically stimulated by B1R antagonists or agonists, respectively, involving a contribution of peripheral immune cells (monocytes) linking hemodynamic conditions with inflammatory pathways.


Asunto(s)
Arterias/crecimiento & desarrollo , Receptor de Bradiquinina B1/fisiología , Receptor de Bradiquinina B2/fisiología , Transducción de Señal/fisiología , Animales , Arteriopatías Oclusivas/metabolismo , Arteriopatías Oclusivas/fisiopatología , Arterias/fisiopatología , Arterias Cerebrales/crecimiento & desarrollo , Arteria Femoral/crecimiento & desarrollo , Miembro Posterior/irrigación sanguínea , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Neovascularización Patológica/fisiopatología , Ratas , Ratas Sprague-Dawley
20.
Technol Health Care ; 31(S1): 111-121, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37038786

RESUMEN

BACKGROUND: With the exponential increase in the volume of biomedical literature, text mining tasks are becoming increasingly important in the medical domain. Named entities are the primary identification tasks in text mining, prerequisites and critical parts for building medical domain knowledge graphs, medical question and answer systems, medical text classification. OBJECTIVE: The study goal is to recognize biomedical entities effectively by fusing multi-feature embedding. Multiple features provide more comprehensive information so that better predictions can be obtained. METHODS: Firstly, three different kinds of features are generated, including deep contextual word-level features, local char-level features, and part-of-speech features at the word representation layer. The word representation vectors are inputs into BiLSTM as features to obtain the dependency information. Finally, the CRF algorithm is used to learn the features of the state sequences to obtain the global optimal tagging sequences. RESULTS: The experimental results showed that the model outperformed other state-of-the-art methods for all-around performance in six datasets among eight of four biomedical entity types. CONCLUSION: The proposed method has a positive effect on the prediction results. It comprehensively considers the relevant factors of named entity recognition because the semantic information is enhanced by fusing multi-features embedding.


Asunto(s)
Algoritmos , Neoplasias Cutáneas , Humanos , Minería de Datos , Aprendizaje , Habla
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