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1.
Cell ; 184(13): 3528-3541.e12, 2021 06 24.
Artigo em Inglês | MEDLINE | ID: mdl-33984278

RESUMO

Nucleotide-binding, leucine-rich repeat receptors (NLRs) are major immune receptors in plants and animals. Upon activation, the Arabidopsis NLR protein ZAR1 forms a pentameric resistosome in vitro and triggers immune responses and cell death in plants. In this study, we employed single-molecule imaging to show that the activated ZAR1 protein can form pentameric complexes in the plasma membrane. The ZAR1 resistosome displayed ion channel activity in Xenopus oocytes in a manner dependent on a conserved acidic residue Glu11 situated in the channel pore. Pre-assembled ZAR1 resistosome was readily incorporated into planar lipid-bilayers and displayed calcium-permeable cation-selective channel activity. Furthermore, we show that activation of ZAR1 in the plant cell led to Glu11-dependent Ca2+ influx, perturbation of subcellular structures, production of reactive oxygen species, and cell death. The results thus support that the ZAR1 resistosome acts as a calcium-permeable cation channel to trigger immunity and cell death.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/imunologia , Arabidopsis/metabolismo , Cálcio/metabolismo , Proteínas de Transporte/metabolismo , Resistência à Doença/imunologia , Imunidade Vegetal , Transdução de Sinais , Animais , Morte Celular , Membrana Celular/metabolismo , Permeabilidade da Membrana Celular , Ácido Glutâmico/metabolismo , Bicamadas Lipídicas/metabolismo , Oócitos/metabolismo , Células Vegetais/metabolismo , Multimerização Proteica , Protoplastos/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Imagem Individual de Molécula , Vacúolos/metabolismo , Xenopus
2.
Mol Cell Proteomics ; 22(12): 100674, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37924977

RESUMO

Salmonella enterica, the etiological agent of gastrointestinal and systemic diseases, translocates a plethora of virulence factors through its type III secretion systems to host cells during infection. Among them, SpvB has been reported to harbor an ADP-ribosyltransferase domain in its C terminus, which destabilizes host cytoskeleton by modifying actin. However, whether this effector targets other host factors as well as the function of its N terminus still remains to be determined. Here, we found that SpvB targets clathrin and its adaptor AP-1 (adaptor protein 1) via interactions with its N-terminal domain. Notably, our data suggest that SpvB-clathrin/AP-1 associations disrupt clathrin-mediated endocytosis and protein secretion pathway as well. In addition, knocking down of AP-1 promotes Salmonella intracellular survival and proliferation in host cells.


Assuntos
Salmonella enterica , Salmonella typhimurium , Salmonella typhimurium/metabolismo , Fator de Transcrição AP-1/metabolismo , Salmonella enterica/metabolismo , Fatores de Virulência/metabolismo , Actinas/metabolismo , Clatrina/metabolismo
3.
Nature ; 552(7685): 410-414, 2017 12 21.
Artigo em Inglês | MEDLINE | ID: mdl-29236694

RESUMO

Vesicular carriers transport proteins and lipids from one organelle to another, recognizing specific identifiers for the donor and acceptor membranes. Two important identifiers are phosphoinositides and GTP-bound GTPases, which provide well-defined but mutable labels. Phosphatidylinositol and its phosphorylated derivatives are present on the cytosolic faces of most cellular membranes. Reversible phosphorylation of its headgroup produces seven distinct phosphoinositides. In endocytic traffic, phosphatidylinositol-4,5-biphosphate marks the plasma membrane, and phosphatidylinositol-3-phosphate and phosphatidylinositol-4-phosphate mark distinct endosomal compartments. It is unknown what sequence of changes in lipid content confers on the vesicles their distinct identity at each intermediate step. Here we describe 'coincidence-detecting' sensors that selectively report the phosphoinositide composition of clathrin-associated structures, and the use of these sensors to follow the dynamics of phosphoinositide conversion during endocytosis. The membrane of an assembling coated pit, in equilibrium with the surrounding plasma membrane, contains phosphatidylinositol-4,5-biphosphate and a smaller amount of phosphatidylinositol-4-phosphate. Closure of the vesicle interrupts free exchange with the plasma membrane. A substantial burst of phosphatidylinositol-4-phosphate immediately after budding coincides with a burst of phosphatidylinositol-3-phosphate, distinct from any later encounter with the phosphatidylinositol-3-phosphate pool in early endosomes; phosphatidylinositol-3,4-biphosphate and the GTPase Rab5 then appear and remain as the uncoating vesicles mature into Rab5-positive endocytic intermediates. Our observations show that a cascade of molecular conversions, made possible by the separation of a vesicle from its parent membrane, can label membrane-traffic intermediates and determine their destinations.


Assuntos
Vesículas Revestidas por Clatrina/química , Vesículas Revestidas por Clatrina/metabolismo , Clatrina/metabolismo , Invaginações Revestidas da Membrana Celular/metabolismo , Endocitose , Endossomos/metabolismo , Fosfatidilinositóis/metabolismo , Animais , Auxilinas/metabolismo , Células COS , Linhagem Celular , Membrana Celular/química , Membrana Celular/metabolismo , Chlorocebus aethiops , Invaginações Revestidas da Membrana Celular/química , Endossomos/química , Humanos , Fosfatidilinositol 4,5-Difosfato/metabolismo , Fosfatos de Fosfatidilinositol/metabolismo , Fosfatidilinositóis/análise , Fosfatidilinositóis/química , Monoéster Fosfórico Hidrolases/metabolismo , Fosforilação , Fosfotransferases/metabolismo , Proteínas rab5 de Ligação ao GTP/metabolismo
4.
Yi Chuan ; 45(2): 165-175, 2023 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-36927663

RESUMO

The currently widely used CRISPR-Cas9 genome editing technology enables the editing of target genes (knock-out or knock-in) with high accuracy and efficiency. Guided by the small guide RNA, the Cas9 nuclease induces a DNA double-strand break at the targeted genomic locus. The DNA double-strand break can be repaired by the homology-directed repair pathway in the presence of a repair template. With the repair template containing the coding sequence of a fluorescent tag, the targeted gene can be inserted with the sequence of a fluorescent tag at the designed position. The genome editing mediated labeling of endogenous proteins with fluorescent tags avoids the potential artifacts caused by gene overexpression and substantially improves the reproductivity of imaging experiments. This protocol focuses on creating mammalian cell lines with endogenous proteins tagged with fluorescent proteins or self-labeling protein tags using CRISPR-Cas9 genome editing.


Assuntos
Sistemas CRISPR-Cas , Edição de Genes , Animais , Edição de Genes/métodos , Proteína 9 Associada à CRISPR/genética , Reparo de DNA por Recombinação , DNA , Mamíferos/genética
5.
Anal Chem ; 90(7): 4282-4287, 2018 04 03.
Artigo em Inglês | MEDLINE | ID: mdl-29509006

RESUMO

The dynamics and stoichiometry of receptors newly delivered on the plasma membrane play a vital role in cell signal transduction, yet knowledge of this process is limited because of the lack of suitable analytical methods. Here we developed a new strategy that combines single-molecule imaging (SMI) and fluorescence recovery after photobleaching (FRAP), named FRAP-SMI, to monitor and quantify individual newly delivered and inserted transmembrane receptors on plasma membranes of living cells. Transforming-growth-factor-ß type II receptor (TßRII), a typical serine/threoninekinase receptor, was studied with this method. We first eliminated the fluorescence signals from the pre-existing EGFP-labeled TßRII molecules on the plasma membrane, and then we recorded the individual newly appeared TßRII-GFP by total-internal-reflection fluorescence imaging. The fluorescence-intensity distributions, photobleaching steps, and diffusion rates of the single TßRII-GFP molecules were analyzed. We reported, for the first time, that TßRII was transported to the plasma membrane mainly in the monomeric form in both resting and TGF-ß1stimulated cells. This strongly supported our former discovery that TßRII could exist as a monomer on the cell membrane. We also found that ligand stimulation resulted in enhanced delivery rates and prolonged membrane-association times for the TßRII molecules. On the basis of these observations, we proposed a mechanism of TGF-ß1-induced TßRII dimerization for receptor activation. Our method provides a useful tool for the real-time quantification of the spatial arrangement, mobility, and oligomerization of cell-surface proteins in living cells, thus providing a better understanding of cell signaling.


Assuntos
Membrana Celular/metabolismo , Imagem Óptica , Receptores de Fatores de Crescimento Transformadores beta/metabolismo , Imagem Individual de Molécula , Membrana Celular/química , Células HeLa , Humanos , Receptores de Fatores de Crescimento Transformadores beta/análise , Células Tumorais Cultivadas
6.
J Virol ; 90(9): 4494-4510, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-26912630

RESUMO

UNLABELLED: Virus entry into cells is a multistep process that often requires the subversion of subcellular machineries. A more complete understanding of these steps is necessary to develop new antiviral strategies. While studying the potential role of the actin network and one of its master regulators, the small GTPase Cdc42, during Junin virus (JUNV) entry, we serendipitously uncovered the small molecule ZCL278, reported to inhibit Cdc42 function as an entry inhibitor for JUNV and for vesicular stomatitis virus, lymphocytic choriomeningitis virus, and dengue virus but not for the nonenveloped poliovirus. Although ZCL278 did not interfere with JUNV attachment to the cell surface or virus particle internalization into host cells, it prevented the release of JUNV ribonucleoprotein cores into the cytosol and decreased pH-mediated viral fusion with host membranes. We also identified SVG-A astroglial cell-derived cells to be highly permissive for JUNV infection and generated new cell lines expressing fluorescently tagged Rab5c or Rab7a or lacking Cdc42 using clustered regularly interspaced short palindromic repeat (CRISPR)-caspase 9 (Cas9) gene-editing strategies. Aided by these tools, we uncovered that perturbations in the actin cytoskeleton or Cdc42 activity minimally affect JUNV entry, suggesting that the inhibitory effect of ZCL278 is not mediated by ZCL278 interfering with the activity of Cdc42. Instead, ZCL278 appears to redistribute viral particles from endosomal to lysosomal compartments. ZCL278 also inhibited JUNV replication in a mouse model, and no toxicity was detected. Together, our data suggest the unexpected antiviral activity of ZCL278 and highlight its potential for use in the development of valuable new tools to study the intracellular trafficking of pathogens. IMPORTANCE: The Junin virus is responsible for outbreaks of Argentine hemorrhagic fever in South America, where 5 million people are at risk. Limited options are currently available to treat infections by Junin virus or other viruses of the Arenaviridae, making the identification of additional tools, including small-molecule inhibitors, of great importance. How Junin virus enters cells is not yet fully understood. Here we describe new cell culture models in which the cells are susceptible to Junin virus infection and to which we applied CRISPR-Cas9 genome engineering strategies to help characterize early steps during virus entry. We also uncovered ZCL278 to be a new antiviral small molecule that potently inhibits the cellular entry of the Junin virus and other enveloped viruses. Moreover, we show that ZCL278 also functions in vivo, thereby preventing Junin virus replication in a mouse model, opening the possibility for the discovery of ZCL278 derivatives of therapeutic potential.


Assuntos
Antivirais/farmacologia , Benzamidas/farmacologia , Descoberta de Drogas , Tioureia/análogos & derivados , Internalização do Vírus/efeitos dos fármacos , Actinas/metabolismo , Animais , Linhagem Celular , Células Cultivadas , Clatrina/metabolismo , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Endocitose/efeitos dos fármacos , Endossomos/efeitos dos fármacos , Endossomos/virologia , Técnicas de Inativação de Genes , Febre Hemorrágica Americana/genética , Febre Hemorrágica Americana/metabolismo , Febre Hemorrágica Americana/virologia , Humanos , Vírus Junin/efeitos dos fármacos , Vírus Junin/fisiologia , Camundongos , Ligação Proteica , Transporte Proteico , Proteólise , Ribonucleoproteínas/metabolismo , Tioureia/farmacologia , Carga Viral , Proteínas Virais/metabolismo , Ligação Viral/efeitos dos fármacos , Replicação Viral/efeitos dos fármacos , Proteína cdc42 de Ligação ao GTP/genética , Proteína cdc42 de Ligação ao GTP/metabolismo
7.
FASEB J ; 29(6): 2495-503, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25690657

RESUMO

Actin and dynamin work cooperatively to drive the invagination and scission of clathrin-coated pits (CCPs). However, little is known about the mechanism that orchestrates the spatiotemporal recruitment of dynamin and actin. Here, we have identified the mammalian actin-binding protein 1 (mAbp1; also called HIP-55 or SH3P7), which could bind to clathrin, actin, as well as dynamin, as an adaptor that links the dynamic recruitment of dynamin and actin for the scission of CCPs. Live-cell imaging reveals that mAbp1 is specifically recruited at a late stage of the long-lived CCPs. mAbp1 knockdown impaired CCP scission by reducing dynamin recruitment at the plasma membrane. However, actin disruption remarkably eliminates mAbp1 recruitment and thus dynamin recruitment. These data suggest that by binding to both clathrin and F-actin, mAbp1 is specifically recruited at a late stage of CCP formation, which subsequently recruits dynamin to CCPs.


Assuntos
Actinas/metabolismo , Clatrina/metabolismo , Invaginações Revestidas da Membrana Celular/metabolismo , Dinaminas/metabolismo , Proteínas dos Microfilamentos/metabolismo , Animais , Linhagem Celular Tumoral , Clatrina/genética , Invaginações Revestidas da Membrana Celular/ultraestrutura , Dinaminas/genética , Humanos , Immunoblotting , Proteínas Luminescentes/genética , Proteínas Luminescentes/metabolismo , Camundongos , Proteínas dos Microfilamentos/genética , Microscopia Eletrônica de Transmissão , Microscopia de Fluorescência/métodos , Células NIH 3T3 , Ligação Proteica , Imagem com Lapso de Tempo/métodos , Domínios de Homologia de src/genética
8.
Jpn J Clin Oncol ; 44(11): 1052-7, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25341545

RESUMO

OBJECTIVE: The aims of the study were to retrospectively evaluate the imaging characteristics of cavernous sinus angioleiomyoma and explore appropriate surgical approaches. METHODS: A total of four cases admitted to our hospital for repeated episodes of headache were enrolled. The common clinical manifestations included decreased vision, diplopia, blepharoptosis and facial numbness. The first three patients were misdiagnosed with cavernous sinus hemangioma, meningioma and chordoma, respectively. The fourth case was suspected to be angioleiomyoma. Imaging examination showed an oval-shaped tumor occupying the cavernous sinus. The tumor was hypointense on T1-weighted magnetic resonance imaging and extremely hyperintense on T2-weighted scan, which was similar to the cerebrospinal fluid, and was progressively enhanced from one side after gadolinium injection, pushing the internal carotid artery toward the inner side. RESULTS: Surgical resection was performed via an epidural approach for these four cases. Clinical symptoms were improved after surgery and no recurrence was observed during follow-up visits (average, 47.5 months). CONCLUSIONS: The initial symptom of cavernous sinus angioleiomyoma was repeated headache. The tumor seems extremely hyperintense on a T2-weighted image and expansive growth is pushing away the internal carotid artery rather than encasing it. It was progressively enhanced from one side after gadolinium injection. Surgical treatment based on an epidural approach had an excellent outcome in tumor resection and nerve protection.


Assuntos
Angiomioma/diagnóstico , Angiomioma/cirurgia , Seio Cavernoso , Neoplasias de Tecido Vascular/diagnóstico , Neoplasias de Tecido Vascular/cirurgia , Adulto , Angiomioma/complicações , Blefaroptose/etiologia , Seio Cavernoso/patologia , Seio Cavernoso/cirurgia , Feminino , Cefaleia/etiologia , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Neoplasias de Tecido Vascular/complicações , Tomografia Computadorizada por Raios X , Resultado do Tratamento , Transtornos da Visão/etiologia
9.
Eur Neurol ; 72(1-2): 116-24, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25011957

RESUMO

BACKGROUND: By definition, a cavernous sinus is a vascular plexus. A hemangioma is a vascular tumor which is rich in vascular plexus and caused by vascular deformity or tumor-like proliferation. Radiosurgery can effectively control the growth of smaller cavernous sinus hemangiomas (CSHs). This paper aimed to quantify the MRI characteristics of CSHs which provided a basis for further treatment. METHODS: A retrospective analysis was conducted of the MRI characteristics of 133 cavernous sinus lesion patients between January 2006 and December 2009, and none of them was diagnosed without histology. Two groups were set apart according to the pathological results: a CSH group (24 patients) and a non-CSH group (109 patients). The latter was further divided into 3 categories: a meningioma group (33 patients), a neurilemmoma group (37 patients) and a miscellaneous group (39 patients). A single-factor χ(2) analysis was performed to analyze the data on the 12 MRI characteristics. RESULTS: T2-weighted ultrahigh signal, signal uniformity, dumbbell-like appearance and infiltration of the sellar region were considered statistically significant for the differentiation of CSHs from non-CSHs. If these 4 items served as the diagnostic criteria, the sensitivity, specificity and accuracy was 87.5, 96.3 and 94.7%, respectively. CONCLUSION: Smaller CSHs can be treated by radiosurgery directly, without performance of a pathological biopsy.


Assuntos
Seio Cavernoso/patologia , Neoplasias do Sistema Nervoso Central/diagnóstico , Neoplasias do Sistema Nervoso Central/patologia , Hemangioma Cavernoso do Sistema Nervoso Central/diagnóstico , Hemangioma Cavernoso do Sistema Nervoso Central/patologia , Imageamento por Ressonância Magnética/métodos , Neoplasias do Sistema Nervoso Central/cirurgia , Hemangioma Cavernoso do Sistema Nervoso Central/cirurgia , Humanos , Meningioma/diagnóstico , Meningioma/patologia , Meningioma/cirurgia , Neurilemoma/diagnóstico , Neurilemoma/patologia , Neurilemoma/cirurgia , Estudos Retrospectivos , Sensibilidade e Especificidade
10.
Chin Neurosurg J ; 10(1): 15, 2024 May 12.
Artigo em Inglês | MEDLINE | ID: mdl-38734681

RESUMO

BACKGROUND: In bypass surgery for moyamoya disease (MMD), the superficial temporal artery's (STA) pressure needs to surpass that of the cortical M4 recipient of the middle cerebral artery (MCA), boosting cerebral blood flow into the MCA and enhancing cerebral circulation. This study investigates the STA-MCA arterial pressure parameters and gradients during bypass surgery, aiming to deepen our understanding of hemodynamic shifts pre- and post-operation. METHODS: DSA imaging data were prospectively collected from patients diagnosed with bilateral MMD who underwent STA-MCA bypass surgery between 2022 and 2023 and stratified according to the Suzuki stage. The mean arterial pressure (MAP) of the donor and recipient arteries was directly measured during the STA-MCA bypass procedure, and these data were statistically analyzed and evaluated. RESULTS: Among 48 MMD patients, Suzuki grading revealed that 43.8% were in early stages (II and III), while 56.2% were in advanced stages (IV, V, and VI). Predominantly, 77.1% presented with ischemic-type MMD and 22.9% with hemorrhagic type. Pre-bypass assessments showed that 62.5% exhibited antegrade blood flow direction, and 37.5% had retrograde. The mean recipient artery pressure was 35.0 ± 2.3 mmHg, with a mean donor-recipient pressure gradient (δP) of 46.4 ± 2.5 mmHg between donor and recipient arteries. Post-bypass, mean recipient artery pressure increased to 73.3 ± 1.6 mmHg. No significant correlation (r = 0.18, P = 0.21) was noted between δP and Suzuki staging. CONCLUSION: Our study elucidated that cerebral blood pressure significantly decreases beyond the moyamoya network at the distal M4 segment. Furthermore, we observed bidirectional flow in MCA territories and a significant positive pressure gradient between the STA and M4 segments. The lack of correlation between Suzuki stages and M4 pressures indicates that angiographic severity may not reflect hemodynamic conditions before surgery, highlighting the need for customized surgical approaches.

11.
iScience ; 27(3): 109180, 2024 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-38439956

RESUMO

Mutations of TRAPPC12 are associated with progressive childhood encephalopathy including abnormal white matter. However, the underlying pathogenesis is still unclear. Here, we found that Trappc12 deficiency in CG4 and oligodendrocyte progenitor cells (OPCs) affects their differentiation and maturation. In addition, TRAPPC12 interacts with Mea6/cTAGE5, and Mea6/cTAGE5 ablation in OPCs affects their proliferation and differentiation, leading to marked hypomyelination, compromised synaptic functionality, and aberrant behaviors in mice. We reveal that TRAPPC12 is associated with COPII components at ER exit site, and Mea6/cTAGE5 cKO disrupts the trafficking pathway by affecting the distribution and/or expression of TRAPPC12, SEC13, SEC31A, and SAR1. Moreover, we observed marked disturbances in the secretion of pleiotrophin (PTN) in Mea6-deficient OPCs. Notably, exogenous PTN supplementation ameliorated the differentiation deficits of these OPCs. Collectively, our findings indicate that the association between TRAPPC12 and MEA6 is important for cargo trafficking and white matter development.

12.
Nat Cell Biol ; 26(6): 917-931, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38714852

RESUMO

Upon endoplasmic reticulum (ER) stress, activation of the ER-resident transmembrane protein kinase/endoribonuclease inositol-requiring enzyme 1 (IRE1) initiates a key branch of the unfolded protein response (UPR) through unconventional splicing generation of the transcription factor X-box-binding protein 1 (XBP1s). Activated IRE1 can form large clusters/foci, whose exact dynamic architectures and functional properties remain largely elusive. Here we report that, in mammalian cells, formation of IRE1α clusters is an ER membrane-bound phase separation event that is coupled to the assembly of stress granules (SGs). In response to different stressors, IRE1α clusters are dynamically tethered to SGs at the ER. The cytosolic linker portion of IRE1α possesses intrinsically disordered regions and is essential for its condensation with SGs. Furthermore, disruption of SG assembly abolishes IRE1α clustering and compromises XBP1 mRNA splicing, and such IRE1α-SG coalescence engenders enrichment of the biochemical components of the pro-survival IRE1α-XBP1 pathway during ER stress. Our findings unravel a phase transition mechanism for the spatiotemporal assembly of IRE1α-SG condensates to establish a more efficient IRE1α machinery, thus enabling higher stress-handling capacity.


Assuntos
Estresse do Retículo Endoplasmático , Endorribonucleases , Proteínas Serina-Treonina Quinases , Proteína 1 de Ligação a X-Box , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Serina-Treonina Quinases/genética , Endorribonucleases/metabolismo , Endorribonucleases/genética , Humanos , Proteína 1 de Ligação a X-Box/metabolismo , Proteína 1 de Ligação a X-Box/genética , Animais , Splicing de RNA , Proteínas de Ligação a DNA/metabolismo , Proteínas de Ligação a DNA/genética , Retículo Endoplasmático/metabolismo , Retículo Endoplasmático/genética , Grânulos de Estresse/metabolismo , Grânulos de Estresse/genética , Fatores de Transcrição de Fator Regulador X/metabolismo , Fatores de Transcrição de Fator Regulador X/genética , Fatores de Transcrição/metabolismo , Fatores de Transcrição/genética , Resposta a Proteínas não Dobradas , Camundongos , Células HeLa , Grânulos Citoplasmáticos/metabolismo , Grânulos Citoplasmáticos/genética , Transdução de Sinais
13.
Anal Bioanal Chem ; 405(1): 43-9, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23001303

RESUMO

Monitoring single molecules in living cells is becoming a powerful tool for study of the location, dynamics, and kinetics of individual biomolecules in real time. In recent decades, several optical imaging techniques, for example epi-fluorescence microscopy, total internal reflection fluorescence microscopy (TIRFM), confocal microscopy, quasi-TIRFM, and single-point edge excitation subdiffraction microscopy (SPEED), have been developed, and their capability of capturing single-molecule dynamics in living cells has been demonstrated. In this review, we briefly summarize recent advances in the use of these imaging techniques for monitoring single-molecules in living cells for a better understanding of important biological processes, and discuss future developments.


Assuntos
Microscopia de Fluorescência/métodos , Algoritmos , Animais , Membrana Celular/metabolismo , Difusão , Corantes Fluorescentes/farmacologia , Humanos , Cinética , Microscopia Confocal/métodos , Modelos Biológicos , Nanotecnologia/métodos , Receptores de Formil Peptídeo/metabolismo , Reprodutibilidade dos Testes , Transdução de Sinais , Fatores de Tempo , Fator de Crescimento Transformador beta/metabolismo
14.
World J Surg Oncol ; 11(1): 187, 2013 Aug 12.
Artigo em Inglês | MEDLINE | ID: mdl-23938115

RESUMO

Prevention of rebleeding plays an important role in the treatment of hemorrhagic moyamoya disease, because rebleeding results in high mortality and morbidity. We discuss possible treatment for patients with moyamoya disease accompanied with distal choroidal artery aneurysms and review the literature to summarize clinical treatment and mechanisms. The cases of three male patients who suffered from intraventricular hemorrhage are presented. Computed tomography (CT) and digital subtractive angiography (DSA) revealed that bleeding was believed to be caused by ruptured aneurysms originating from distal choroidal artery aneurysms. Two patients successfully underwent superficial temporal artery (STA)-middle cerebral artery (MCA) bypass combined with encephalo-duro-myo-synangiosis (EDMS) and the obliteration of the aneurysm. The follow-up DSA or CT scan demonstrated that the aneurysms completely disappeared with the patency of the reconstructed artery. Neither of the patients experienced rebleeding during the follow-up period (up to 34 months). Given conservative treatment, the third patient experienced recurrent hemorrhages 4 months after the first ictus. This study describes treatment for moyamoya disease accompanied with distal choroidal artery aneurysms. Our experience suggests that cerebral revascularization combined with obliteration of the complicated distal aneurysm in the same session is a possible treatment.


Assuntos
Aneurisma Roto/cirurgia , Artérias Cerebrais/cirurgia , Aneurisma Intracraniano/cirurgia , Doença de Moyamoya/cirurgia , Adulto , Aneurisma Roto/complicações , Aneurisma Roto/patologia , Angiografia Digital , Artérias Cerebrais/patologia , Humanos , Aneurisma Intracraniano/complicações , Aneurisma Intracraniano/patologia , Masculino , Pessoa de Meia-Idade , Doença de Moyamoya/complicações , Doença de Moyamoya/patologia , Complicações Pós-Operatórias , Prognóstico , Literatura de Revisão como Assunto , Tomografia Computadorizada por Raios X
15.
World Neurosurg ; 178: e345-e354, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37480987

RESUMO

OBJECTIVE: Cavernous sinus hemangiomas (CSHs) are infrequent benign neoplasms. This meta-analysis was conducted with the objective of examining the prognostic outcomes of surgical interventions and radiotherapy (RT) in patients diagnosed with CSHs. METHODS: A comprehensive literature search was performed across PubMed, Embase, and Web of Science databases, with traceability up to June 22, 2021. The evaluation of continuous variables was conducted by applying the weighted mean difference (WMD) and 95% confidence interval. A one-arm meta-analysis was used to scrutinize the tumor control rate, clinical improvement rate, recovery rates of abducens nerve palsy and visual disturbance, total resection rate, and the incidence rate of permanent nerve palsy post-treatment. RESULTS: In total, 29 articles were incorporated into the meta-analysis. Post-RT for CSHs, a significant reduction in tumor volume was observed (WMD [95% confidence interval] = -17.16 [-21.52, -12.80] cm3). The tumor control rate, clinical improvement rate, recovery rate of abducens nerve palsy, and the recovery rate of visual disturbance were 97.1% (92.9, 99.7), 91.9% (82.3, 98.5), 95.6% (83.2, 100.0), and 86.3% (65.0, 99.5), respectively. Following surgical treatment, the total resection rate, mean intraoperative blood loss, recovery rate of visual disturbance, incidence rate of permanent nerve palsy, and recovery rate of abducens nerve palsy were 73.2% (57.1, 86.9), 971.17 mL (584.07, 1358.27), 66.4% (32.4, 0.942), 16.0% (4.6, 31.1), and 70.6% (51.0, 87.7), respectively. Notably, the recovery rate of abducens nerve palsy post-RT was markedly higher than postsurgical treatment. CONCLUSIONS: The results of this meta-analysis underscore that RT is an effective and safe treatment modality for CSHs. Furthermore, the prognostic outcomes of RT demonstrated superiority over surgical intervention.

16.
Cell Discov ; 9(1): 18, 2023 Feb 13.
Artigo em Inglês | MEDLINE | ID: mdl-36781849

RESUMO

HER2 belongs to the human epidermal growth factor receptor tyrosine kinase family. Its overexpression or hyperactivation is a leading cause for multiple types of cancers. HER2 functions mainly through dimerization with other family members, such as EGFR. However, the molecular details for heterodimer assembly have not been completely understood. Here, we report cryo-EM structures of the EGF- and epiregulin-bound EGFR/HER2 ectodomain complexes at resolutions of 3.3 Å and 4.5 Å, respectively. Together with the functional analyses, we demonstrate that only the dimerization arm of HER2, but not that of EGFR, is essential for their heterodimer formation and signal transduction. Moreover, we analyze the differential membrane dynamics and transient interactions of endogenous EGFR and HER2 molecules in genome-edited cells using single-molecule live-cell imaging. Furthermore, we show that the interaction with HER2 could allow EGFR to resist endocytosis. Together, this work deepens our understanding of the unique structural properties and dynamics of the EGFR/HER2 complex.

17.
Nat Biotechnol ; 41(3): 367-377, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36203012

RESUMO

The goal when imaging bioprocesses with optical microscopy is to acquire the most spatiotemporal information with the least invasiveness. Deep neural networks have substantially improved optical microscopy, including image super-resolution and restoration, but still have substantial potential for artifacts. In this study, we developed rationalized deep learning (rDL) for structured illumination microscopy and lattice light sheet microscopy (LLSM) by incorporating prior knowledge of illumination patterns and, thereby, rationally guiding the network to denoise raw images. Here we demonstrate that rDL structured illumination microscopy eliminates spectral bias-induced resolution degradation and reduces model uncertainty by five-fold, improving the super-resolution information by more than ten-fold over other computational approaches. Moreover, rDL applied to LLSM enables self-supervised training by using the spatial or temporal continuity of noisy data itself, yielding results similar to those of supervised methods. We demonstrate the utility of rDL by imaging the rapid kinetics of motile cilia, nucleolar protein condensation during light-sensitive mitosis and long-term interactions between membranous and membrane-less organelles.


Assuntos
Aprendizado Profundo , Microscopia de Fluorescência/métodos , Redes Neurais de Computação
18.
Nat Commun ; 14(1): 8165, 2023 Dec 09.
Artigo em Inglês | MEDLINE | ID: mdl-38071397

RESUMO

Cells living in geometrically confined microenvironments are ubiquitous in various physiological processes, e.g., wound closure. However, it remains unclear whether and how spatially geometric constraints on host cells regulate bacteria-host interactions. Here, we reveal that interactions between bacteria and spatially constrained cell monolayers exhibit strong spatial heterogeneity, and that bacteria tend to adhere to these cells near the outer edges of confined monolayers. The bacterial adhesion force near the edges of the micropatterned monolayers is up to 75 nN, which is ~3 times higher than that at the centers, depending on the underlying substrate rigidities. Single-cell RNA sequencing experiments indicate that spatially heterogeneous expression of collagen IV with significant edge effects is responsible for the location-dependent bacterial adhesion. Finally, we show that collagen IV inhibitors can potentially be utilized as adjuvants to reduce bacterial adhesion and thus markedly enhance the efficacy of antibiotics, as demonstrated in animal experiments.


Assuntos
Aderência Bacteriana , Colágeno , Animais , Aderência Bacteriana/fisiologia , Colágeno/metabolismo , Fenômenos Mecânicos , Bactérias/metabolismo , Adesão Celular
19.
J Nanosci Nanotechnol ; 12(6): 4478-84, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22905488

RESUMO

This study provides a parallel cytotoxicity study of water-soluble single-walled carbon nanotubes and fullerene C70(C(COOH)2)4-8 on Nicotiana tabacum BY-2 cells. After BY-2 cells were treated with single-walled carbon nanotubes or C70(C(COOH)2)4-8, the cells adopted a shrunken morphology and exhibited lower proliferation rate. Fluorescence imaging of the treated cells revealed increased reactive oxygen species generation, abnormal mitochondrial distribution, decreased mitochondrial activity, and impaired actin cytoskeleton arrangement. However, no obvious cells death was induced by either single-walled carbon nanotubes or C70(C(COOH)2)4-8. Compared with single-walled carbon nanotubes, C70(C(COOH)2)4-8 exerted more serious adverse effects on BY-2 cells.


Assuntos
Nanotubos de Carbono/efeitos adversos , Nicotiana/efeitos dos fármacos , Nicotiana/fisiologia , Espécies Reativas de Oxigênio/metabolismo , Apoptose/efeitos dos fármacos , Linhagem Celular , Proliferação de Células/efeitos dos fármacos , Tamanho Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Teste de Materiais , Nanotubos de Carbono/química , Solubilidade , Nicotiana/citologia , Água/química
20.
World Neurosurg ; 160: e464-e470, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-35051640

RESUMO

OBJECTIVE: We sought to explore a treatment protocol for patients with mesial temporal cerebral cavernoma (MTC)-associated epilepsy. METHODS: All MTC-associated epilepsy patients admitted to our center between January 2005 and December 2013 were analyzed. Seizure outcome for each presurgical epilepsy type was reported. The modified Engel classification was used to assess outcome. The neurologic outcome was scored by the modified Rankin Scale. RESULTS: Fifty-three patients admitted to the center were seen by a functional electrocortigraphy (ECoG group) or vascular (non-ECoG group) neurosurgery team. There were 21 patients with drug-resistant epilepsy (DRE), 20 patients with chronic epilepsy (CE), and 12 patients with sporadic epilepsy (SE). The neurovascular team treated 37 (69.8%) patients, and the ECoG group treated 16 (30.2%) patients. All patients underwent a mean follow-up of 106.5 ± 29.1 months. Almost all SE patients (11/12, 91.7%) in both teams achieved seizure-free status at follow-up. In the CE group, the long-term seizure-free probability among patients in the ECoG and non-ECoG groups was (66.7%) and (52.9%), respectively. DRE patients in the ECoG group had a lower seizure relapse rate after surgery than those who underwent non-ECoG surgery (P = 0.042). Fifty-two patients (98.1%) complained of postsurgery memory loss. Seizure outcome in the first postoperative year was a reasonable predictor of long-term outcome. CONCLUSIONS: A comprehensive preoperative and intraoperative assessment could help the patient with MTC-associated epilepsy choose a suitable surgical time and maximize the benefit between seizure control and cognition protection. The characters of intraoperative ECoG and postoperative seizure outcome at 1-year follow-up can predict a long-term epilepsy prognosis.


Assuntos
Epilepsia do Lobo Temporal , Epilepsia , Eletrocorticografia/métodos , Eletroencefalografia , Epilepsia/complicações , Epilepsia/cirurgia , Humanos , Recidiva Local de Neoplasia/complicações , Convulsões/complicações , Convulsões/cirurgia , Lobo Temporal/diagnóstico por imagem , Lobo Temporal/cirurgia , Resultado do Tratamento
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