Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 86
Filtrar
1.
Naunyn Schmiedebergs Arch Pharmacol ; 397(4): 2241-2255, 2024 04.
Artigo em Inglês | MEDLINE | ID: mdl-37812239

RESUMO

Sepsis is a systemic illness for which there are no effective preventive or therapeutic therapies. Zerumbone, a natural molecule, has anti-oxidative and anti-inflammatory properties that may help to prevent sepsis. In the present study, we have assessed the protective effect of zerumbone against sepsis-induced acute lung injury (ALI) and its underlying mechanisms. During the experiment, mice were divided into five groups: a sham group, a sepsis-induced ALI group, and three sepsis groups that are pre-treated with zerumbone at different concentrations. We found that zerumbone greatly decreased the sepsis-induced ALI using histological investigations. Also, zerumbone treatment reduced the sepsis-induced inflammatory cytokine concentrations as well as the number of infiltrating inflammatory cells in BALF compared to non-treated sepsis animals. The zerumbone-pretreated sepsis groups had reduced pulmonary myeloperoxidase (MPO) activity than the sepsis groups. Moreover, the mechanism underlying the protective action of zerumbone on sepsis is accomplished by the activation of antioxidant genes such as nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), superoxide dismutase (SOD), and heme oxygenase 1 (HO-1). The obtained results revealed that zerumbone inhibited the sepsis-induced ALI through its anti-inflammatory and antioxidative activity via inhibition of the NF-κB pathway and activation of HO-1 pathway. Our findings demonstrate that zerumbone pretreatment suppresses sepsis-induced ALI via antioxidative activities and anti-inflammatory, implying that zerumbone could be a viable preventive agent for sepsis-induced ALI.


Assuntos
Lesão Pulmonar Aguda , Sepse , Sesquiterpenos , Animais , Camundongos , NF-kappa B/metabolismo , Antioxidantes/farmacologia , Transdução de Sinais , Heme Oxigenase-1/metabolismo , Lipopolissacarídeos/farmacologia , Lesão Pulmonar Aguda/patologia , Anti-Inflamatórios/farmacologia , Pulmão , Sepse/tratamento farmacológico
2.
Mol Biol Cell ; 35(2): ar14, 2024 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-38019611

RESUMO

Myosin 10 (Myo10) couples microtubules and integrin-based adhesions to movement along actin filaments via its microtubule-binding MyTH4 domain and integrin-binding FERM domain, respectively. Here we show that Myo10-depleted HeLa cells and mouse embryo fibroblasts (MEFs) both exhibit a pronounced increase in the frequency of multipolar spindles. Staining of unsynchronized metaphase cells showed that the primary driver of spindle multipolarity in Myo10-depleted MEFs and in Myo10-depleted HeLa cells lacking supernumerary centrosomes is pericentriolar material (PCM) fragmentation, which creates y-tubulin-positive acentriolar foci that serve as extra spindle poles. For HeLa cells possessing supernumerary centrosomes, Myo10 depletion further accentuates spindle multipolarity by impairing the clustering of the extra spindle poles. Complementation experiments show that Myo10 must interact with both microtubules and integrins to promote PCM/pole integrity. Conversely, Myo10 only needs interact with integrins to promote supernumerary centrosome clustering. Importantly, images of metaphase Halo-Myo10 knockin cells show that the myosin localizes exclusively to the spindle and the tips of adhesive retraction fibers. We conclude that Myo10 promotes PCM/pole integrity in part by interacting with spindle microtubules, and that it promotes supernumerary centrosome clustering by supporting retraction fiber-based cell adhesion, which likely serves to anchor the microtubule-based forces driving pole focusing.


Assuntos
Centrossomo , Fuso Acromático , Camundongos , Humanos , Animais , Células HeLa , Fuso Acromático/metabolismo , Centrossomo/metabolismo , Microtúbulos/metabolismo , Miosinas/metabolismo , Integrinas/metabolismo , Mitose
3.
J Cancer Res Clin Oncol ; 149(20): 17973-17986, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37966613

RESUMO

PURPOSE: HPV integration usually occurs in HPV-related cancer, and is the main cause of cancer. But the carcinogenic mechanism of HPV integration is unclear. The study aims to provide a theoretical basis for understanding the pathogenesis of cervical adenocarcinoma (AC) and cervical squamous carcinoma (SCC). METHODS: We used HPV capture sequencing to obtain HPV integration sites in AC and SCC, and analyzed cytobands, distribution of genetic and genomic elements, identified integration hotspot genes, clinicopathological parameters, breakpoints of HPV16 and performed pathway analysis. Then we conducted immunohistochemical (IHC) assay to preliminarily verify the expression of most frequently integrated genes in AC, STARD3 and ERBB2. RESULTS: The results revealed that the most frequently observed integrated cytoband was 17q12 in AC and 21p11.2 in SCC, respectively. The breakpoints in both AC and SCC were more tended to occur within gene regions, compared to intergenetic regions. Compared to SCC samples, AC samples had a higher prevalence of genomic elements. In AC, HPV integration has no significantly difference with clinicopathological parameters, but in SCC integration correlated with differentiation (P < 0.05). Breakpoints of HPV in SCC located in LCR more frequently compared to AC, which destroyed the activation of promoter p97. Hotspot genes of HPV integration were STARD3 and ERBB2 in AC, and RNA45S rDNA and MIR3648-1 in SCC, respectively. Meanwhile, we preliminarily proved that the expression of STARD3 and ERBB2, the most frequently integrated genes, would increase after integration. CONCLUSION: These results suggested that HPV may utilize the powerful hosts' promoters to express viral oncogenes and overexpression of viral oncogenes plays a significant role in the carcinogenesis of SCC. In AC, HPV integration may affect hosts' oncogenes, and the dysregulation of oncogenes may primarily contribute to progression of AC.


Assuntos
Adenocarcinoma , Carcinoma de Células Escamosas , Infecções por Papillomavirus , Neoplasias do Colo do Útero , Feminino , Humanos , Infecções por Papillomavirus/complicações , Infecções por Papillomavirus/genética , Infecções por Papillomavirus/epidemiologia , Papillomavirus Humano 16 , Adenocarcinoma/genética , Papillomaviridae/genética
4.
Infect Drug Resist ; 16: 6549-6566, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37817839

RESUMO

Purpose: The aim of this study was to establish risk prediction and prognosis models for multidrug-resistant bacterial infections (MDRB) in elderly patients with pulmonary infections in a multicenter setting. Patients and Methods: This study is a retrospective cohort analysis in Anhui province of China. Data dimension reduction and feature selection were performed using the lasso regression model. Multifactorial regression analysis to identify risk factors associated with MDRB infection and prognosis. The relevant risks of each patient in the prognostic training cohort were scored based on prognostic independent risk factors. Subsequently, patients were classified into high-risk and low-risk groups, and survival differences were compared between them. Finally, models were established based on independent risk factors for infection, risk groups, and independent prognostic factors, and were presented on nomograms. The predictive accuracy of the model was assessed using corresponding external validation set data. Results: The study cohort comprised 994 elderly patients with pulmonary infection. Multivariate analysis revealed that endotracheal intubation, previous antibiotic use beyond 2 weeks, and concurrent respiratory failure or cerebrovascular disease were independent risk factors associated with the incidence of MDRB infection. Cox regression analysis identified respiratory failure, malnutrition, an APACHE II score of at least 20, and higher blood creatinine levels as independent prognostic risk factors. The models were validated using an external validation dataset from multiple centers, which demonstrated good diagnostic ability and a good fit with a fair benefit. Conclusion: In conclusion, our study provides an appropriate and generalisable assessment of risk factors affecting infection and prognosis in patients with MDRB, contributing to improved early identification of patients at higher risk of infection and death, and appropriately guiding clinical management.

5.
Nature ; 620(7976): 1109-1116, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37612506

RESUMO

Dominant optic atrophy is one of the leading causes of childhood blindness. Around 60-80% of cases1 are caused by mutations of the gene that encodes optic atrophy protein 1 (OPA1), a protein that has a key role in inner mitochondrial membrane fusion and remodelling of cristae and is crucial for the dynamic organization and regulation of mitochondria2. Mutations in OPA1 result in the dysregulation of the GTPase-mediated fusion process of the mitochondrial inner and outer membranes3. Here we used cryo-electron microscopy methods to solve helical structures of OPA1 assembled on lipid membrane tubes, in the presence and absence of nucleotide. These helical assemblies organize into densely packed protein rungs with minimal inter-rung connectivity, and exhibit nucleotide-dependent dimerization of the GTPase domains-a hallmark of the dynamin superfamily of proteins4. OPA1 also contains several unique secondary structures in the paddle domain that strengthen its membrane association, including membrane-inserting helices. The structural features identified in this study shed light on the effects of pathogenic point mutations on protein folding, inter-protein assembly and membrane interactions. Furthermore, mutations that disrupt the assembly interfaces and membrane binding of OPA1 cause mitochondrial fragmentation in cell-based assays, providing evidence of the biological relevance of these interactions.


Assuntos
Microscopia Crioeletrônica , GTP Fosfo-Hidrolases , Mitocôndrias , GTP Fosfo-Hidrolases/química , GTP Fosfo-Hidrolases/genética , GTP Fosfo-Hidrolases/metabolismo , GTP Fosfo-Hidrolases/ultraestrutura , Fusão de Membrana , Mitocôndrias/enzimologia , Mitocôndrias/metabolismo , Mitocôndrias/patologia , Dinâmica Mitocondrial , Membranas Mitocondriais/metabolismo , Mutação , Nucleotídeos/metabolismo , Ligação Proteica/genética , Domínios Proteicos , Dobramento de Proteína , Multimerização Proteica , Estrutura Secundária de Proteína , Humanos
6.
bioRxiv ; 2023 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-37398378

RESUMO

Myosin 10 (Myo10) has the ability to link actin filaments to integrin-based adhesions and to microtubules by virtue of its integrin-binding FERM domain and microtubule-binding MyTH4 domain, respectively. Here we used Myo10 knockout cells to define Myo10's contribution to the maintenance of spindle bipolarity, and complementation to quantitate the relative contributions of its MyTH4 and FERM domains. Myo10 knockout HeLa cells and mouse embryo fibroblasts (MEFs) both exhibit a pronounced increase in the frequency of multipolar spindles. Staining of unsynchronized metaphase cells showed that the primary driver of spindle multipolarity in knockout MEFs and knockout HeLa cells lacking supernumerary centrosomes is pericentriolar material (PCM) fragmentation, which creates γ-tubulin-positive acentriolar foci that serve as additional spindle poles. For HeLa cells possessing supernumerary centrosomes, Myo10 depletion further accentuates spindle multipolarity by impairing the clustering of the extra spindle poles. Complementation experiments show that Myo10 must interact with both integrins and microtubules to promote PCM/pole integrity. Conversely, Myo10's ability to promote the clustering of supernumerary centrosomes only requires that it interact with integrins. Importantly, images of Halo-Myo10 knock-in cells show that the myosin localizes exclusively within adhesive retraction fibers during mitosis. Based on these and other results, we conclude that Myo10 promotes PCM/pole integrity at a distance, and that it facilitates supernumerary centrosome clustering by promoting retraction fiber-based cell adhesion, which likely provides an anchor for the microtubule-based forces driving pole focusing.

7.
Cancer Manag Res ; 15: 635-644, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37457377

RESUMO

Objective: To evaluate the diagnostic value of DNA methylation detection of multiple gene loci in cervical cancer. Methods: A total of 61 cases requiring cervical biopsy were selected from the outpatient clinic of Maternal and Child Health Hospital of Hubei Province between January 2018 and December 2019. The patients were divided into four groups based on histopathologic diagnosis: cervical cancer (CC) group, high-grade squamous intraepithelial lesion (HSIL) group, low-grade squamous intraepithelial lesion (LSIL) group, and control group. HPV examination, liquid-based cytology examination, and DNA methylation detection at multiple gene sites were performed. The positive rate of DNA methylation, sensitivity, specificity, area under the curve (AUC), and other efficacy indexes were calculated to evaluate the diagnostic value of DNA methylation detection at multiple gene loci in cervical cancer. Results: The positive rates of DNA methylation in CC, HSIL, LSIL, and control groups were 100%, 88%, 83% and 17%, respectively. The ZNF671 gene had the highest positive rate among the cervical lesion group, with rates of 57%, 76%, and 100% in LSIL, HSIL, and CC groups respectively. The combination of DNA methylation detection at multiple gene loci showed the highest diagnostic efficacy for HSIL and cervical cancer, with AUC value of 0.850 (95% CI:0.746-0.954), a Youden index of 0.654, and a sensitivity and specificity of 85% and 85.4%, respectively. The diagnostic efficacy of the combined detection was significantly higher than that of HPV examination and liquid-based cytology examination (P < 0.05). Conclusion: DNA methylation detection at multiple gene loci is highly effective and diagnostic tool for cervical cancer, and has potential application value in clinical practice.

8.
Theranostics ; 13(4): 1355-1369, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36923530

RESUMO

Objectives: Glutamic pyruvate transaminase (GPT2) catalyzes the reversible transamination between alanine and α-ketoglutarate (α-KG) to generate pyruvate and glutamate during cellular glutamine catabolism. The glutamate could be further converted to γ-aminobutyric acid (GABA). However, the role of GPT2 in tumor metastasis remains unclear. Methods: The wound healing and transwell assays were carried out to analyze breast cancer cell migration and invasion in vitro. Gene ontology analysis was utilized following RNA-sequencing to discover the associated molecule function. The mass spectrometry analysis following phosphoprotein enrichment was performed to discover the associated transcription factors. Most importantly, both the tail vein model and Mammary gland conditional Gpt2-/- spontaneous tumor mouse models were used to evaluate the effect of GPT2 on breast cancer metastasis in vivo. Results: GPT2 overexpression increases the content of GABA and promotes breast cancer metastasis by activating GABAA receptors. The delta subunit GABRD is necessary for the GPT2/GABA-induced breast cancer metastasis in xenograft and transgenic mouse models. Gpt2 knockout reduces the lung metastasis of the genetic Gpt2-/- breast cancer in mice and prolongs the overall survival of tumor burden mice. Mechanistically, GPT2-induced GABAA receptor activation increases Ca2+ influx by turning on its associated calcium channel, and the surged intracellular calcium triggers the PKC-CREB pathway activation. The activated transcription factor CREB accelerates breast cancer metastasis by upregulating metastasis-related gene expressions, such as PODXL, MMP3, and MMP9. Conclusion: In summary, this study demonstrates that GPT2 promotes breast cancer metastasis through up-regulated GABA activation of GABAAR-PKC-CREB signaling, suggesting it is a potential target for breast cancer therapy.


Assuntos
Neoplasias da Mama , Segunda Neoplasia Primária , Animais , Feminino , Humanos , Camundongos , Alanina Transaminase , Neoplasias da Mama/genética , Neoplasias da Mama/patologia , Ácido gama-Aminobutírico , Glutamatos , Camundongos Transgênicos , Piruvatos , Receptores de GABA-A , Transaminases/genética , Melanoma Maligno Cutâneo
10.
Curr Med Chem ; 30(18): 2006-2019, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36330637

RESUMO

BACKGROUND: Cantharidin (CTD) is a highly toxic substance which can be used to treat a variety of cancers. However, the clinical application of CTD is restricted due to the serious side effects. In recent years, screening its analogues, exploring the mechanism of action and using combinatory therapy with certain substances are considered to be feasible methods which can reduce side effects and improve the therapeutic activity of CTD. This review aims to describe SAR (structure-activity relationship) of CTD analogues, CTD induction mechanisms, and combinatory therapy exploration. METHODS: We searched for research about CTD by entering the database. Important information was screened and extracted purposefully, including SAR, mechanisms, methods, etc. Finally, these contents were unified into a framework to form a review. RESULTS: Some CTD analogues with imidazolium salt or double bonds at C-5 and C-6 positions demonstrate good anticancer activity. Through introducing methyl and acetoxy groups at the C-1 or C-4 position, the inhibitory effect of PP was weakened or even inactivated. Removing the two methyl groups of C-2 and C-3 can reduce side effects and improve efficacy. Replacing methyl with fluorine can also improve the activity and reduce toxicity. Water solubility and bioavailability could be improved by opening the five fivemembered anhydride ring to form carboxylic acid, salt, amide, and ester derivatives. The anticancer mechanism can be divided into the following aspects, including inhibiting cell invasion and metastasis, inducing apoptosis, regulating cell cycle and enhancing immunity. The proper formulation of CTD and its analogues (liposomes, nanoparticles and micelles) can improve the targeting of liver cancer and reduce toxic and side effects. CTD combined with anti-angiogenic therapeutics (Ginsenoside Rg3, Bevacizumab, Apatinib and Endostar) showed additive anti-pancreatic cancer effects. CONCLUSION: It was found that the potential mechanism was closely related to multi-channel and multi-target interactions, which provided a guiding direction for the later exploration of new clinical therapeutic applications. However, some detailed mechanisms are still unclear, and more evidence is required to verify. In addition, the new methods to improve the therapeutic potential of CTD and its analogues still need more clinical trials to be tested in the future. This prospect is very broad and worthy of further study.


Assuntos
Antineoplásicos , Neoplasias Hepáticas , Cantaridina/farmacologia , Cantaridina/uso terapêutico , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Lipossomos , Neoplasias Hepáticas/tratamento farmacológico , Apoptose , Humanos
11.
Front Oncol ; 12: 980884, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36185239

RESUMO

Few studies have investigated the absence of high-grade cervical intraepithelial neoplasia (CIN) in excised specimens, and sample sizes of these studies were limited. This study retrospectively analyzed clinical characteristics of 1695 patients with CIN 2/3 to determine the incidence rate and relative factors of CIN 1 or less in conization specimens from patients with colposcopic biopsy-confirmed CIN 2/3. The study group comprised 430 cases of CIN 1 or less in conization specimens, and the control group comprised 1142 cases with high-grade CIN lesions in conization specimens. Univariate and multivariate logistic regression models were established to evaluate relative factors. The 1-9 years follow-up data were analyzed to determine the persistence/recurrence rate. Multivariate logistic regression showed that patients aged 18-24 years (OR (95% CI) = 2.224 (1.014, 4.877)); with a negative hrHPV test result (OR (95% CI) = 3.210 (1.627, 6.331)); a cytology test result of normal (OR (95% CI) = 5.184 (3.138, 8.563)), ASC-US (OR (95% CI) = 3.420 (2.102, 5.564)), LSIL (OR (95% CI) = 2.588 (1.475, 4.541)), or ASC-H (OR (95% CI) = 2.434 (1.306, 4.539)); an indication of CIN 2 on biopsy (OR (95% CI) = 2.290 (1.694, 3.096)), and no glandular involvement (OR (95% CI) = 1.616 (1.205, 2.169)) were more likely to have an absence of high-grade dysplasia in conization specimens. There was no difference in the persistence/recurrence rate between the two groups (x2 = 1.55, P = 0.46). An age of 18-24 years, a negative hrHPV test result, a non-HSIL cytology test result, an indication of CIN 2 on biopsy, and no glandular involvement were relative factors for an absence of high-grade dysplasia in conization specimens. For patients with relative factors, especially young women, informed follow-up should be considered.

13.
Cells ; 11(12)2022 06 12.
Artigo em Inglês | MEDLINE | ID: mdl-35741037

RESUMO

Signaling through the TNF-family receptor Fas/CD95 can trigger apoptosis or non-apoptotic cellular responses and is essential for protection from autoimmunity. Receptor clustering has been observed following interaction with Fas ligand (FasL), but the stoichiometry of Fas, particularly when triggered by membrane-bound FasL, the only form of FasL competent at inducing programmed cell death, is not known. Here we used super-resolution microscopy to study the behavior of single molecules of Fas/CD95 on the plasma membrane after interaction of Fas with FasL on planar lipid bilayers. We observed rapid formation of Fas protein superclusters containing more than 20 receptors after interactions with membrane-bound FasL. Fluorescence correlation imaging demonstrated recruitment of FADD dependent on an intact Fas death domain, with lipid raft association playing a secondary role. Flow-cytometric FRET analysis confirmed these results, and also showed that some Fas clustering can occur in the absence of FADD and caspase-8. Point mutations in the Fas death domain associated with autoimmune lymphoproliferative syndrome (ALPS) completely disrupted Fas reorganization and FADD recruitment, confirming structure-based predictions of the critical role that these residues play in Fas-Fas and Fas-FADD interactions. Finally, we showed that induction of apoptosis correlated with the ability to form superclusters and recruit FADD.


Assuntos
Apoptose , Receptor fas , Apoptose/fisiologia , Análise por Conglomerados , Proteína Ligante Fas/metabolismo , Proteína de Domínio de Morte Associada a Fas/metabolismo , Receptores do Fator de Necrose Tumoral/metabolismo , Receptor fas/metabolismo
14.
Elife ; 112022 04 11.
Artigo em Inglês | MEDLINE | ID: mdl-35404237

RESUMO

B-cell activation and immune synapse (IS) formation with membrane-bound antigens are actin-dependent processes that scale positively with the strength of antigen-induced signals. Importantly, ligating the B-cell integrin, LFA-1, with ICAM-1 promotes IS formation when antigen is limiting. Whether the actin cytoskeleton plays a specific role in integrin-dependent IS formation is unknown. Here, we show using super-resolution imaging of mouse primary B cells that LFA-1:ICAM-1 interactions promote the formation of an actomyosin network that dominates the B-cell IS. This network is created by the formin mDia1, organized into concentric, contractile arcs by myosin 2A, and flows inward at the same rate as B-cell receptor (BCR):antigen clusters. Consistently, individual BCR microclusters are swept inward by individual actomyosin arcs. Under conditions where integrin is required for synapse formation, inhibiting myosin impairs synapse formation, as evidenced by reduced antigen centralization, diminished BCR signaling, and defective signaling protein distribution at the synapse. Together, these results argue that a contractile actomyosin arc network plays a key role in the mechanism by which LFA-1 co-stimulation promotes B-cell activation and IS formation.


The immune system has the ability to recognize a vast array of infections and trigger rapid responses. This defense mechanism is mediated in part by B cells which make antibodies that can neutralize or destroy specific disease-causing agents. When pathogens (such as bacteria or viruses) invade the body, a specialized immune cell called an 'antigen presenting cell' holds it in place and presents it to the B cell to examine. Receptors on the surface of the B cell then bind to the infectious agent and launch the B cell into action, triggering the antibody response needed to remove the pathogen. This process relies on B cells and antigen presenting cells making a close connection called an immune synapse, which has a bulls-eye pattern with the receptor in the middle surrounded by sticky proteins called adhesion molecules. A network of actin filaments coating the inside of the B cell are responsible for arranging the proteins into this bulls-eye shape. Once fully formed, the synapse initiates the production of antibodies and helps B cells to make stronger versions of these defensive proteins. So far, most studies have focused on the role the receptor plays in B cell activation. However, when there are only small amounts of the pathogen available, these receptors bind to the antigen presenting cell very weakly. When this happens, adhesion molecules have been shown to step in and promote the formation of the mature synapse needed for B cell activation. But it is not fully understood how adhesion molecules do this. To investigate, Wang et al. looked at mouse B cells using super resolution microscopes. This revealed that when B cells receive signals through both their receptors and their adhesion molecules, they rearrange their actin into a circular structure composed of arc shapes. Motors on the actin arcs then contract the structure inwards, pushing the B cell receptors into the classic bullseye pattern. This only happened when adhesion molecules were present and signals through the B cell receptors were weak. These findings suggest that adhesion molecules help form immune synapses and activate B cells by modifying the actin network so it can drive the re-patterning of receptor proteins. B cells are responsible for the long-term immunity provided by vaccines. Thus, it is possible that the findings of Wang et al. could be harnessed to create vaccines that trigger a stronger antibody response.


Assuntos
Actomiosina , Linfócitos B , Sinapses Imunológicas , Antígeno-1 Associado à Função Linfocitária , Citoesqueleto de Actina/metabolismo , Actinas/metabolismo , Actomiosina/metabolismo , Animais , Linfócitos B/imunologia , Molécula 1 de Adesão Intercelular/metabolismo , Antígeno-1 Associado à Função Linfocitária/metabolismo , Camundongos , Miosinas/metabolismo , Receptores de Antígenos de Linfócitos B/metabolismo
15.
PLoS One ; 16(12): e0252845, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34962917

RESUMO

The cytokinetic contractile ring (CR) was first described some 50 years ago, however our understanding of the assembly and structure of the animal cell CR remains incomplete. We recently reported that mature CRs in sea urchin embryos contain myosin II mini-filaments organized into aligned concatenated arrays, and that in early CRs myosin II formed discrete clusters that transformed into the linearized structure over time. The present study extends our previous work by addressing the hypothesis that these myosin II clusters also contain the crucial scaffolding proteins anillin and septin, known to help link actin, myosin II, RhoA, and the membrane during cytokinesis. Super-resolution imaging of cortices from dividing embryos indicates that within each cluster, anillin and septin2 occupy a centralized position relative to the myosin II mini-filaments. As CR formation progresses, the myosin II, septin and anillin containing clusters enlarge and coalesce into patchy and faintly linear patterns. Our super-resolution images provide the initial visualization of anillin and septin nanostructure within an animal cell CR, including evidence of a septin filament-like network. Furthermore, Latrunculin-treated embryos indicated that the localization of septin or anillin to the myosin II clusters in the early CR was not dependent on actin filaments. These results highlight the structural progression of the CR in sea urchin embryos from an array of clusters to a linearized purse string, the association of anillin and septin with this process, and provide the visualization of an apparent septin filament network with the CR structure of an animal cell.


Assuntos
Proteínas Contráteis/metabolismo , Citocinese , Embrião não Mamífero/metabolismo , Miosina Tipo II/metabolismo , Ouriços-do-Mar/embriologia , Ouriços-do-Mar/metabolismo , Septinas/metabolismo , Citoesqueleto de Actina/metabolismo , Animais , Anticorpos/metabolismo , Proteínas Contráteis/química , Proteínas Contráteis/imunologia , Imageamento Tridimensional , Domínios Proteicos , Septinas/imunologia , Proteínas rho de Ligação ao GTP/metabolismo
16.
Nature ; 600(7888): 279-284, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34837071

RESUMO

Confocal microscopy1 remains a major workhorse in biomedical optical microscopy owing to its reliability and flexibility in imaging various samples, but suffers from substantial point spread function anisotropy, diffraction-limited resolution, depth-dependent degradation in scattering samples and volumetric bleaching2. Here we address these problems, enhancing confocal microscopy performance from the sub-micrometre to millimetre spatial scale and the millisecond to hour temporal scale, improving both lateral and axial resolution more than twofold while simultaneously reducing phototoxicity. We achieve these gains using an integrated, four-pronged approach: (1) developing compact line scanners that enable sensitive, rapid, diffraction-limited imaging over large areas; (2) combining line-scanning with multiview imaging, developing reconstruction algorithms that improve resolution isotropy and recover signal otherwise lost to scattering; (3) adapting techniques from structured illumination microscopy, achieving super-resolution imaging in densely labelled, thick samples; (4) synergizing deep learning with these advances, further improving imaging speed, resolution and duration. We demonstrate these capabilities on more than 20 distinct fixed and live samples, including protein distributions in single cells; nuclei and developing neurons in Caenorhabditis elegans embryos, larvae and adults; myoblasts in imaginal disks of Drosophila wings; and mouse renal, oesophageal, cardiac and brain tissues.


Assuntos
Aprendizado Profundo , Microscopia Confocal/métodos , Microscopia Confocal/normas , Animais , Caenorhabditis elegans/citologia , Caenorhabditis elegans/embriologia , Caenorhabditis elegans/crescimento & desenvolvimento , Linhagem Celular Tumoral , Drosophila melanogaster/citologia , Drosophila melanogaster/crescimento & desenvolvimento , Humanos , Discos Imaginais/citologia , Camundongos , Mioblastos/citologia , Especificidade de Órgãos , Análise de Célula Única , Fixação de Tecidos
17.
Acta Cytol ; 65(5): 385-392, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34482310

RESUMO

OBJECTIVE: The objective of this study was to evaluate the application of DNA ploidy analysis in large-scale population screening for cervical cancer. METHODS: From March 2016 to March 2019, eligible subjects were enrolled and recommended to undergo DNA ploidy analysis, the ThinPrep cytology test (TCT), and high-risk human papillomavirus (hrHPV) detection concurrently. Patients with positive results were recommended for colposcopy, and biopsy diagnosis was regarded as the "gold standard." We compared the test efficiencies of the 3 methods and compared the efficiency and accuracy of the TCT in our hospital and the "2-cancer screening" project in Hubei Province during the same period. RESULTS: Among 20,574 women, the positive rates of DNA ploidy analysis, cytology, and hrHPV testing were 4.01%, 4.71%, and 16.28%, respectively. The sensitivities of these methods for screening for grade 2+ cervical intraepithelial neoplasia were 0.70, 0.68, and 0.96, and their specificities were 0.79, 0.82, and 0.45, respectively. On comparing DNA ploidy analysis with the TCT, there was no significant difference in the sensitivity, specificity, positive predictive value, negative predictive value, and missed diagnosis rate. In opportunistic screening and the 2-cancer screening project, the positive rates of cytology were 4.71% and 2.87%, respectively. And the efficiency and accuracy of the TCT in opportunistic screening were higher than in the 2-cancer screening project. CONCLUSION: Therefore, DNA ploidy analysis, which is of low-cost and does not depend on cytopathologists, can replace cytology and be applied in large-scale population screening for cervical cancer.


Assuntos
Programas de Rastreamento , Infecções por Papillomavirus/virologia , Displasia do Colo do Útero/genética , Neoplasias do Colo do Útero/diagnóstico , Neoplasias do Colo do Útero/genética , Adulto , Biópsia , Citodiagnóstico/métodos , DNA , Detecção Precoce de Câncer/métodos , Feminino , Humanos , Programas de Rastreamento/métodos , Pessoa de Meia-Idade , Papillomaviridae/genética , Gravidez , Sensibilidade e Especificidade , Neoplasias do Colo do Útero/patologia , Adulto Jovem , Displasia do Colo do Útero/diagnóstico , Displasia do Colo do Útero/patologia
18.
Front Oncol ; 11: 659445, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34458135

RESUMO

BACKGROUND: Emerging evidence indicates that the tumor microenvironment influences tumor progression and patient prognosis through various inflammatory cells. Polymorphonuclear neutrophils (PMNs) and their functional structures termed neutrophil extracellular traps (NETs) are prominent constituents of several malignant tumors and affect the tumor microenvironment and cancer evolution. Here, we investigate the prognostic value of PMNs and NETs for recurrence in patients with cervical cancer. METHODS: The study comprised 126 cervical cancer patients who were retrospectively enrolled. CD66b+ neutrophils and myeloperoxidase/citrullinated histone H3 (MPO/H3Cit)-labeled NETs were assessed by immunofluorescence, and the relationships with clinical and histopathologic features and patient outcome were evaluated. RESULTS: The highest density of CD66b+ neutrophils were observed in the stromal compartment (median 55 cells/mm2). Above median densities of stromal CD66b+ neutrophils and NETs were significantly associated with short recurrence-free survival (RFS) (P = 0.041 and P = 0.006, respectively). Multivariate analysis identified high clinical stage (hazard ratio [HR] 6.40; 95% confidence interval [CI] 3.51-11.64; P < 0.001), lymph node metastases (HR 4.69; 95% CI 3.09-9.66; P = 0.006) and high density of NETs (HR 2.66; 95% CI 1.21-5.82; P = 0.015) as independent prognostic factors for short RFS, whereas a high density of CD66b+ neutrophils was not significant. Patients with a high NET density showed worse recurrence status in every stage, but the difference was only significant for stage I (P = 0.042), not stages II, III, or IV (all P > 0.05). Combining stromal NET density and the tumor, nodes, metastasis (TNM) staging system had better prognostic accuracy for cervical cancer than the TNM staging system alone at five and six years respectively (P = 0.010 and P = 0.023). CONCLUSION: Stromal NET density is an independent prognostic factor for RFS in cervical cancer. Combining NETs with the TNM staging system may further improve prognostic stratification.

19.
Methods Mol Biol ; 2304: 111-130, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34028713

RESUMO

The Zeiss Airyscan microscope transforms a diffraction-limited, point-scanning confocal microscope into a super-resolution microscope using a specialized 32-channel Airyscan detector. By improving resolution twofold and signal-to-noise ratio eightfold relative to conventional confocal microscopes while retaining confocal functionality, the Airyscan microscope has become a very popular super-resolution imaging tool for cell biologists. In this chapter, we describe the fundamentals of Airyscan imaging, with the aim of helping the reader determine the proper acquisition settings for different types of experiments, optimize imaging conditions, and process the raw Airyscan images to obtain final images with the best quality. We also provide some tips, tricks, and best practices for Airyscan imaging. Of note, while our focus is on the Airyscan function of this microscope rather than its conventional confocal function, the Airyscan unit comes as an add-on to the conventional Zeiss laser scanning confocal microscope. This protocol is for the first generation Airyscan Zeiss 800 series microscope.


Assuntos
Microscopia Confocal/instrumentação , Humanos , Imageamento Tridimensional , Razão Sinal-Ruído , Interface Usuário-Computador
20.
Elife ; 102021 05 18.
Artigo em Inglês | MEDLINE | ID: mdl-34003115

RESUMO

Hedgehog (Hh) signaling patterns embryonic tissues and contributes to homeostasis in adults. In Drosophila, Hh transport and signaling are thought to occur along a specialized class of actin-rich filopodia, termed cytonemes. Here, we report that Interference hedgehog (Ihog) not only forms a Hh receptor complex with Patched to mediate intracellular signaling, but Ihog also engages in trans-homophilic binding leading to cytoneme stabilization in a manner independent of its role as the Hh receptor. Both functions of Ihog (trans-homophilic binding for cytoneme stabilization and Hh binding for ligand sensing) involve a heparin-binding site on the first fibronectin repeat of the extracellular domain. Thus, the Ihog-Ihog interaction and the Hh-Ihog interaction cannot occur simultaneously for a single Ihog molecule. By combining experimental data and mathematical modeling, we determined that Hh-Ihog heterophilic interaction dominates and Hh can disrupt and displace Ihog molecules involved in trans-homophilic binding. Consequently, we proposed that the weaker Ihog-Ihog trans interaction promotes and stabilizes direct membrane contacts along cytonemes and that, as the cytoneme encounters secreted Hh ligands, the ligands trigger release of Ihog from trans Ihog-Ihog complex enabling transport or internalization of the Hh ligand-Ihog-Patched -receptor complex. Thus, the seemingly incompatible functions of Ihog in homophilic adhesion and ligand binding cooperate to assist Hh transport and reception along the cytonemes.


Assuntos
Proteínas de Drosophila/genética , Proteínas de Drosophila/metabolismo , Drosophila melanogaster/metabolismo , Proteínas Hedgehog/metabolismo , Glicoproteínas de Membrana/metabolismo , Receptores de Superfície Celular/metabolismo , Transdução de Sinais/fisiologia , Animais , Linhagem Celular , Proteínas Hedgehog/genética , Glicoproteínas de Membrana/genética , Modelos Teóricos , Domínios Proteicos , Receptores de Superfície Celular/genética
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...