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1.
Mol Cell ; 75(4): 859-874.e4, 2019 08 22.
Artigo em Inglês | MEDLINE | ID: mdl-31351878

RESUMO

Homologous recombination (HR) is essential for high-fidelity DNA repair during mitotic proliferation and meiosis. Yet, context-specific modifications must tailor the recombination machinery to avoid (mitosis) or enforce (meiosis) the formation of reciprocal exchanges-crossovers-between recombining chromosomes. To obtain molecular insight into how crossover control is achieved, we affinity purified 7 DNA-processing enzymes that channel HR intermediates into crossovers or noncrossovers from vegetative cells or cells undergoing meiosis. Using mass spectrometry, we provide a global characterization of their composition and reveal mitosis- and meiosis-specific modules in the interaction networks. Functional analyses of meiosis-specific interactors of MutLγ-Exo1 identified Rtk1, Caf120, and Chd1 as regulators of crossing-over. Chd1, which transiently associates with Exo1 at the prophase-to-metaphase I transition, enables the formation of MutLγ-dependent crossovers through its conserved ability to bind and displace nucleosomes. Thus, rewiring of the HR network, coupled to chromatin remodeling, promotes context-specific control of the recombination outcome.


Assuntos
Troca Genética/fisiologia , Meiose/fisiologia , Mitose/fisiologia , Proteínas de Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/metabolismo , Espectrometria de Massas , Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/genética
2.
PLoS Pathog ; 19(10): e1011682, 2023 10.
Artigo em Inglês | MEDLINE | ID: mdl-37782657

RESUMO

Human cytomegalovirus (HCMV) encodes multiple putative G protein-coupled receptors (GPCRs). US28 functions as a viral chemokine receptor and is expressed during both latent and lytic phases of virus infection. US28 actively promotes cellular migration, transformation, and plays a major role in mediating viral latency and reactivation; however, knowledge about the interaction partners involved in these processes is still incomplete. Herein, we utilized a proximity-dependent biotinylating enzyme (TurboID) to characterize the US28 interactome when expressed in isolation, and during both latent (CD34+ hematopoietic progenitor cells) and lytic (fibroblasts) HCMV infection. Our analyses indicate that the US28 signalosome converges with RhoA and EGFR signal transduction pathways, sharing multiple mediators that are major actors in processes such as cellular proliferation and differentiation. Integral members of the US28 signaling complex were validated in functional assays by immunoblot and small-molecule inhibitors. Importantly, we identified RhoGEFs as key US28 signaling intermediaries. In vitro latency and reactivation assays utilizing primary CD34+ hematopoietic progenitor cells (HPCs) treated with the small-molecule inhibitors Rhosin or Y16 indicated that US28 -RhoGEF interactions are required for efficient viral reactivation. These findings were recapitulated in vivo using a humanized mouse model where inhibition of RhoGEFs resulted in a failure of the virus to reactivate. Together, our data identifies multiple new proteins in the US28 interactome that play major roles in viral latency and reactivation, highlights the utility of proximity-sensor labeling to characterize protein interactomes, and provides insight into targets for the development of novel anti-HCMV therapeutics.


Assuntos
Citomegalovirus , Transdução de Sinais , Animais , Camundongos , Humanos , Citomegalovirus/fisiologia , Latência Viral , Diferenciação Celular , Células-Tronco Hematopoéticas
3.
Proc Natl Acad Sci U S A ; 118(3)2021 01 19.
Artigo em Inglês | MEDLINE | ID: mdl-33431668

RESUMO

Homologous recombination (HR) is an important DNA double-strand break (DSB) repair pathway that copies sequence information lost at the break site from an undamaged homologous template. This involves the formation of a recombination structure that is processed to restore the original sequence but also harbors the potential for crossover (CO) formation between the participating molecules. Synthesis-dependent strand annealing (SDSA) is an HR subpathway that prevents CO formation and is thought to predominate in mammalian cells. The chromatin remodeler ATRX promotes an alternative HR subpathway that has the potential to form COs. Here, we show that ATRX-dependent HR outcompetes RECQ5-dependent SDSA for the repair of most two-ended DSBs in human cells and leads to the frequent formation of COs, assessed by measuring sister chromatid exchanges (SCEs). We provide evidence that subpathway choice is dependent on interaction of both ATRX and RECQ5 with proliferating cell nuclear antigen. We also show that the subpathway usage varies among different cancer cell lines and compare it to untransformed cells. We further observe HR intermediates arising as ionizing radiation (IR)-induced ultra-fine bridges only in cells expressing ATRX and lacking MUS81 and GEN1. Consistently, damage-induced MUS81 recruitment is only observed in ATRX-expressing cells. Cells lacking BLM show similar MUS81 recruitment and IR-induced SCE formation as control cells. Collectively, these results suggest that the ATRX pathway involves the formation of HR intermediates whose processing is entirely dependent on MUS81 and GEN1 and independent of BLM. We propose that the predominant ATRX-dependent HR subpathway forms joint molecules distinct from classical Holliday junctions.


Assuntos
Proteínas de Ligação a DNA/genética , Endonucleases/genética , Recombinação Homóloga/genética , RecQ Helicases/genética , Proteína Nuclear Ligada ao X/genética , Proliferação de Células/genética , Montagem e Desmontagem da Cromatina/genética , Quebras de DNA de Cadeia Dupla , Reparo do DNA/genética , DNA Cruciforme/genética , Resolvases de Junção Holliday/genética , Humanos , Antígeno Nuclear de Célula em Proliferação/genética , Radiação Ionizante , Transdução de Sinais/genética
4.
Postgrad Med J ; 96(1131): 9-13, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31324730

RESUMO

BACKGROUND: After primary percutaneous coronary intervention (PPCI) in patients with acute ST elevation myocardial infarction (STEMI), dual antiplatelet therapy (DAPT) is recommended to continue for 1 year. Occasionally, DAPT interruption may be required due to bleeding issues or unplanned surgical procedures. OBJECTIVE: To systematically evaluate the incidence of DAPT interruption within 1 year after PPCI. METHODS AND RESULTS: This was a single-centre, retrospective registry study. Consecutive patients with STEMI who underwent PPCI from 2013 to 2017 (N=538) were recruited into the analysis. The primary outcome was the incidence of interruption of DAPT within 1 year from the index PPCI. Secondary outcomes included incidence of bleeding in 1 year and prevalence of high bleeding risk (HBR) criteria at index presentation. Within 1 year, 17.1% (84/490) of post-PPCI survivors needed DAPT interruption and 7.1% (35/490) had major bleeding (Bleeding Academic Research Consortium type 3 or 5). At index presentation, HBR criteria were present in 36.1% (194/538) of patients. On univariate analysis, age, female gender, anaemia, anticoagulation, diabetes, hypertension and being a non-smoker were associated with DAPT interruption. On multivariate analysis, age was the only independent factor to predict DAPT interruption. CONCLUSION: DAPT interruption was not uncommon after PPCI in patients with STEMI particularly in the elderly. This has implication on stent selection during PPCI, and further studies are required to investigate which type of stent may best suit our real-life patients with STEMI.


Assuntos
Terapia Antiplaquetária Dupla , Hemorragia , Intervenção Coronária Percutânea , Complicações Pós-Operatórias , Infarto do Miocárdio com Supradesnível do Segmento ST/cirurgia , Terapia Antiplaquetária Dupla/efeitos adversos , Terapia Antiplaquetária Dupla/métodos , Feminino , Hemorragia/induzido quimicamente , Hemorragia/prevenção & controle , Hemorragia/terapia , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Seleção de Pacientes , Intervenção Coronária Percutânea/instrumentação , Intervenção Coronária Percutânea/métodos , Complicações Pós-Operatórias/etiologia , Complicações Pós-Operatórias/prevenção & controle , Fatores de Risco , Stents/normas , Procedimentos Cirúrgicos Operatórios/efeitos adversos , Procedimentos Cirúrgicos Operatórios/métodos , Suspensão de Tratamento/estatística & dados numéricos
5.
Circ J ; 83(4): 809-817, 2019 03 25.
Artigo em Inglês | MEDLINE | ID: mdl-30799311

RESUMO

BACKGROUND: Patients who survive myocardial infarction (MI) are at risk of recurrent cardiovascular (CV) events. This study stratified post-MI patients for risk of recurrent CV events using the Thrombolysis in Myocardial Infarction (TIMI) Risk Score for Secondary Prevention (TRS 2°P). Methods and Results: This was an observational study that applied TRS 2°P to a consecutive cohort of post-MI patients. The primary outcome was a composite endpoint of CV death, non-fatal MI, and non-fatal ischemic stroke. A total of 1,688 post-MI patients (70.3±13.6 years; male, 63.1%) were enrolled. After a mean follow-up of 41.5±34.4 months, 405 patients (24.0%) had developed a primary outcome (9.3%/year) consisting of 278 CV deaths, 134 non-fatal MI, and 33 non-fatal strokes. TRS 2°P was strongly associated with the primary outcome. The annual incidence of primary composite endpoint for patients with TRS 2°P 0 was 1.0%, and increased progressively to 39.9% for those with TRS 2°P ≥6 (HR, 27.6; 95% CI: 9.87-77.39, P<0.001). The diagnostic sensitivity of TRS 2°P for the primary composite endpoint was 76.3% (95% CI: 72.1-80.5%). Similar associations were also observed between TRS 2°P and CV death and non-fatal MI, but not non-fatal ischemic stroke. CONCLUSIONS: TRS 2°P reliably stratified post-MI patients for risk of future CV events.


Assuntos
Doenças Cardiovasculares/prevenção & controle , Infarto do Miocárdio/diagnóstico , Medição de Risco/métodos , Prevenção Secundária/métodos , Idoso , Idoso de 80 Anos ou mais , Doenças Cardiovasculares/mortalidade , Estudos de Coortes , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Recidiva , Acidente Vascular Cerebral , Terapia Trombolítica
6.
Postgrad Med J ; 95(1125): 372-377, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31123174

RESUMO

BACKGROUND: Patients who survive non-ST-elevation myocardial infarction (NSTEMI) are at heightened risk of recurrent cardiovascular events. Data on long-term secondary atherothrombotic risk stratification are limited. OBJECTIVES: To stratify post-NSTEMI patients for risk of recurrent cardiovascular events to maximise benefit from aggressive secondary prevention strategies using the TIMI Risk Score for Secondary Prevention (TRS 2°P) score in a real-world cohort of NSTEMI patients. METHODS AND RESULTS: This was a single-centre observational study of 891 post-NSTEMI patients (73.7 ± 12.7 years; male: 54.2%). The TRS 2°P is a nine-point risk stratification tool to predict cardiovascular events in patients with established cardiovascular disease. The primary outcome was a composite endpoint of cardiovascular death, non-fatal MI and non-fatal ischaemic stroke. After a median follow-up of 31 months (IQR: 11.4 - 60.2), 281 patients (31.5%) had developed a primary outcome (13.3%/year) including 196 cardiovascular deaths, 94 non-fatal MIs and 22 non-fatal strokes. The TRS 2°P score was strongly associated with the primary outcome. The annual incidence of primary composite endpoint for patients with TRS 2°P score =0 was 1.6%, and increased progressively to 47.4% for those with a TRS 2°P score ≥6 (HR: 20.18, 95% CI: 4.85 to 84.05, p<0.001). Similar associations were also observed between the TRS 2°P score and cardiovascular death and MI (fatal and non-fatal), but not non-fatal ischaemic stroke. CONCLUSION: The TRS 2°P score stratified post-NSTEMI patients for risk of future cardiovascular events and potentially help guide the selection of more aggressive secondary prevention therapy.


Assuntos
Doenças Cardiovasculares/prevenção & controle , Causas de Morte , Infarto do Miocárdio sem Supradesnível do Segmento ST/terapia , Sistema de Registros , Prevenção Secundária/métodos , Centros Médicos Acadêmicos , Síndrome Coronariana Aguda/mortalidade , Síndrome Coronariana Aguda/prevenção & controle , Idoso , Idoso de 80 Anos ou mais , Isquemia Encefálica/etiologia , Isquemia Encefálica/prevenção & controle , Doenças Cardiovasculares/etiologia , Doenças Cardiovasculares/mortalidade , Feminino , Hong Kong , Humanos , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Infarto do Miocárdio sem Supradesnível do Segmento ST/diagnóstico por imagem , Infarto do Miocárdio sem Supradesnível do Segmento ST/mortalidade , Valor Preditivo dos Testes , Recidiva , Estudos Retrospectivos , Medição de Risco , Acidente Vascular Cerebral/etiologia , Acidente Vascular Cerebral/prevenção & controle , Análise de Sobrevida , Sobreviventes
7.
Biochim Biophys Acta Mol Cell Res ; 1864(1): 1-11, 2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-27751885

RESUMO

Members of the herpesviral family use multiple strategies to hijack infected host cells and exploit cellular signaling for their pathogenesis and latent infection. Among the most intriguing weapons in the arsenal of pathogenic herpesviruses are the constitutively active virally-encoded G protein-coupled receptors (vGPCRs). Even though vGPCRs contribute to viral pathogenesis such as immune evasion and proliferative disorders, the molecular details of how vGPCRs continuously activate cellular signaling are largely unknown. Here, we report that the vGPCR of Herpesvirus saimiri (HVS), an oncogenic γ2-herpesvirus, constitutively activates T cells via a heteromeric interaction with cellular CXCR4. Constitutive T cell activation also occurs with expression of the vGPCR of Kaposi's sarcoma-associated herpesvirus (KSHV), but not the vGPCR of Epstein-Barr virus. Expression of HVS vGPCR down-regulated the surface expression of CXCR4 but did not induce the degradation of the chemokine receptor, suggesting that vGPCR/CXCR4 signaling continues in cytosolic compartments. The physical association of vGPCR with CXCR4 was demonstrated by proximity ligation assay as well as immunoprecipitation. Interestingly, the constitutive activation of T cells by HVS vGPCR is independent of proximal T cell receptor (TCR) signaling molecules, such as TCRß, Lck, and ZAP70, whereas CXCR4 silencing by shRNA abolished T cell activation by vGPCRs of HVS and KSHV. Furthermore, previously identified inactive vGPCR mutants failed to interact with CXCR4. These findings on the positive cooperativity of vGPCR with cellular CXCR4 in T cell activation extend our current understanding of the molecular mechanisms of vGPCR function and highlight the importance of heteromerization for GPCR activity.


Assuntos
Herpesvirus Saimiriíneo 2/metabolismo , Herpesvirus Humano 8/metabolismo , Receptores CXCR4/genética , Receptores de Quimiocinas/genética , Linfócitos T/virologia , Regulação da Expressão Gênica , Células HEK293 , Herpesvirus Saimiriíneo 2/genética , Herpesvirus Saimiriíneo 2/crescimento & desenvolvimento , Herpesvirus Humano 4/genética , Herpesvirus Humano 4/crescimento & desenvolvimento , Herpesvirus Humano 4/metabolismo , Herpesvirus Humano 8/genética , Herpesvirus Humano 8/crescimento & desenvolvimento , Interações Hospedeiro-Patógeno , Humanos , Ativação Linfocitária , Proteína Tirosina Quinase p56(lck) Linfócito-Específica/genética , Proteína Tirosina Quinase p56(lck) Linfócito-Específica/imunologia , Proteína Tirosina Quinase p56(lck) Linfócito-Específica/metabolismo , Cultura Primária de Células , Ligação Proteica , Multimerização Proteica , Receptores de Antígenos de Linfócitos T alfa-beta/genética , Receptores de Antígenos de Linfócitos T alfa-beta/imunologia , Receptores de Antígenos de Linfócitos T alfa-beta/metabolismo , Receptores CXCR4/imunologia , Receptores CXCR4/metabolismo , Receptores de Quimiocinas/imunologia , Receptores de Quimiocinas/metabolismo , Transdução de Sinais , Linfócitos T/imunologia , Linfócitos T/metabolismo , Proteína-Tirosina Quinase ZAP-70/genética , Proteína-Tirosina Quinase ZAP-70/imunologia , Proteína-Tirosina Quinase ZAP-70/metabolismo
8.
Appl Microbiol Biotechnol ; 100(15): 6601-6617, 2016 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-27338574

RESUMO

Fungi comprise organisms like molds, yeasts and mushrooms. They have been used as food or medicine for a long time. A large number of fungal proteins or peptides with diverse biological activities are considered as antibacterial, antifungal, antiviral and anticancer agents. They encompass proteases, ribosome inactivating proteins, defensins, hemolysins, lectins, laccases, ribonucleases, immunomodulatory proteins, and polysaccharopeptides. The target of the present review is to update the status of the various bioactivities of these fungal proteins and peptides and discuss their therapeutic potential.


Assuntos
Proteínas Fúngicas/metabolismo , Proteínas Fúngicas/farmacologia , Fungos/metabolismo , Antibacterianos/farmacologia , Antifúngicos/farmacologia , Antineoplásicos/farmacologia , Antivirais/farmacologia , Proliferação de Células/efeitos dos fármacos , Defensinas/farmacologia , Fatores Imunológicos/farmacologia , Proteínas Inativadoras de Ribossomos/farmacologia
9.
J Nanobiotechnology ; 14(1): 76, 2016 Nov 26.
Artigo em Inglês | MEDLINE | ID: mdl-27887623

RESUMO

BACKGROUND: Zinc oxide nanoparticle (ZNP) has been applied in various biomedical fields. Here, we investigated the usage of ZNP as an antigen carrier for vaccine development by combining a high affinity peptide to ZNP. RESULTS: A novel zinc oxide-binding peptide (ZBP), FPYPGGDA, with high affinity to ZNP (K a  = 2.26 × 106 M-1) was isolated from a random peptide library and fused with a bacterial antigen, ScaA of Orientia tsutsugamushi, the causative agent of scrub typhus. The ZNP/ZBP-ScaA complex was efficiently phagocytosed by a dendritic cell line, DC2.4, in vitro and significantly enhanced anti-ScaA antibody responses in vivo compared to control groups. In addition, immunization with the ZNP/ZBP-ScaA complex promoted the generation of IFN-γ-secreting T cells in an antigen-dependent manner. Finally, we observed that ZNP/ZBP-ScaA immunization provided protective immunity against lethal challenge of O. tsutsugamushi, indicating that ZNP can be used as a potent adjuvant when complexed with ZBP-conjugated antigen. CONCLUSIONS: ZNPs possess good adjuvant potential as a vaccine carrier when combined with an antigen having a high affinity to ZNP. When complexed with ZBP-ScaA antigen, ZNPs could induce strong antibody responses as well as protective immunity against lethal challenges of O. tsutsugamushi. Therefore, application of ZNPs combined with a specific soluble antigen could be a promising strategy as a novel vaccine carrier system.


Assuntos
Antígenos de Bactérias/imunologia , Nanopartículas Metálicas/química , Orientia tsutsugamushi/metabolismo , Tifo por Ácaros/prevenção & controle , Óxido de Zinco/química , Sequência de Aminoácidos , Animais , Anticorpos Antibacterianos/imunologia , Antígenos de Bactérias/química , Antígenos de Bactérias/genética , Materiais Biocompatíveis/química , Linfócitos T CD4-Positivos/citologia , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD8-Positivos/citologia , Linfócitos T CD8-Positivos/imunologia , Linhagem Celular , Citocinas/metabolismo , Células Dendríticas/citologia , Células Dendríticas/imunologia , Feminino , Camundongos , Camundongos Endogâmicos C57BL , Orientia tsutsugamushi/imunologia , Peptídeos/química , Fagocitose , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/química , Proteínas Recombinantes/imunologia , Tifo por Ácaros/veterinária , Vacinação
10.
Appl Microbiol Biotechnol ; 99(8): 3359-74, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25761622

RESUMO

Nanocomposites containing nanoparticles or nanostructured domains exhibit an even higher degree of material complexity that leads to an extremely high variability of nanostructured materials. This review introduces analytical concepts and techniques for nanomaterials and derives recommendations for a qualified selection of characterization techniques for specific types of samples, and focuses the characterization of nanoparticles and their agglomerates or aggregates. In addition, DNA nanotechnology and the more recent newcomer RNA nanotechnology have achieved almost an advanced status among nanotechnology researchers¸ therefore, the core features, potential, and significant challenges of DNA nanotechnology are also highlighted as a new discipline. Moreover, nanobiochips made by nanomaterials are rapidly emerging as a new paradigm in the area of large-scale biochemical analysis. The use of nanoscale components enables higher precision in diagnostics while considerably reducing the cost of the platform that leads this review to explore the use of nanoparticles, nanomaterials, and other bionanotechnologies for its application to nanodiagnostics in-vitro.


Assuntos
DNA/metabolismo , Técnicas In Vitro/métodos , Técnicas de Diagnóstico Molecular/métodos , Nanopartículas , Nanotecnologia/métodos , RNA/metabolismo , DNA/genética , RNA/genética
11.
J Virol ; 87(22): 12499-503, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-24027317

RESUMO

Autophagy is an important innate safeguard mechanism for protecting an organism against invasion by pathogens. We have previously discovered that Kaposi's sarcoma-associated herpesvirus (KSHV) evades this host defense through tight suppression of autophagy by targeting multiple steps of autophagy signal transduction. Here, we report that KSHV K7 protein interacts with Rubicon autophagy protein and inhibits the autophagosome maturation step by blocking Vps34 enzymatic activity, further highlighting how KSHV deregulates autophagy-mediated host immunity for its life cycle.


Assuntos
Autofagia , Herpesvirus Humano 8/fisiologia , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Proteínas Mitocondriais/metabolismo , Fagossomos/metabolismo , Sarcoma de Kaposi/patologia , Proteínas Virais/metabolismo , Proteínas Relacionadas à Autofagia , Células HeLa , Humanos , Immunoblotting , Sarcoma de Kaposi/metabolismo , Sarcoma de Kaposi/virologia , Transdução de Sinais
12.
Antonie Van Leeuwenhoek ; 106(2): 197-209, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24803238

RESUMO

Phenotypic and genotypic changes in Aspergillus niger and Penicillium chrysogenum, spore forming filamentous fungi, with respect to central chitin metabolism were studied under low shear modeled microgravity, normal gravity and static conditions. Low shear modeled microgravity (LSMMG) response showed a similar spore germination rate with normal gravity and static conditions. Interestingly, high ratio of multiple germ tube formation of A. niger in LSMMG condition was observed. Confocal laser scanning microscopy images of calcofluor flurophore stained A. niger and P. chrysogenum showed no significant variations between different conditions tested. Transmission electron microscopy images revealed number of mitochondria increased in P. chrysogenum in low shear modeled microgravity condition but no stress related-woronin bodies in fungal hyphae were observed. To gain additional insight into the cell wall integrity under different conditions, transcription level of a key gene involved in cell wall integrity gfaA, encoding the glutamine: fructose-6-phosphate amidotransferase enzyme, was evaluated using qRT-PCR. The transcription level showed no variation among different conditions. Overall, the results collectively indicate that the LSMMG has shown no significant stress on spore germination, mycelial growth, cell wall integrity of potentially pathogenic fungi, A. niger and P. chrysogenum.


Assuntos
Aspergillus niger/fisiologia , Quitina/metabolismo , Penicillium chrysogenum/fisiologia , Estresse Fisiológico , Ausência de Peso , Aspergillus niger/crescimento & desenvolvimento , Aspergillus niger/metabolismo , Aspergillus niger/ultraestrutura , Fungos/crescimento & desenvolvimento , Fungos/metabolismo , Fungos/fisiologia , Fungos/ultraestrutura , Perfilação da Expressão Gênica , Glutamina-Frutose-6-Fosfato Transaminase (Isomerizante)/biossíntese , Glutamina-Frutose-6-Fosfato Transaminase (Isomerizante)/genética , Microscopia Confocal , Microscopia Eletrônica de Transmissão , Organelas/ultraestrutura , Penicillium chrysogenum/crescimento & desenvolvimento , Penicillium chrysogenum/metabolismo , Penicillium chrysogenum/ultraestrutura , Reação em Cadeia da Polimerase em Tempo Real , Esporos Fúngicos/crescimento & desenvolvimento
13.
Metabolites ; 13(2)2023 Jan 19.
Artigo em Inglês | MEDLINE | ID: mdl-36837772

RESUMO

The importance of RNAs is commonly recognised thanks to protein-coding RNAs, whereas non-coding RNAs (ncRNAs) were conventionally regarded as 'junk'. In the last decade, ncRNAs' significance and roles are becoming noticeable in various biological activities, including those in hormonal and metabolic regulation. Among the ncRNAs: microRNA (miRNA) is a small RNA transcript with ~20 nucleotides in length; long non-coding RNA (lncRNA) is an RNA transcript with >200 nucleotides; and circular RNA (circRNA) is derived from back-splicing of pre-mRNA. These ncRNAs can regulate gene expression levels at epigenetic, transcriptional, and post-transcriptional levels through various mechanisms in insects. A better understanding of these crucial regulators is essential to both basic and applied entomology. In this review, we intend to summarise and discuss the current understanding and knowledge of miRNA, lncRNA, and circRNA in the best-studied insect model, the fruit fly Drosophila.

14.
Micromachines (Basel) ; 14(5)2023 Apr 23.
Artigo em Inglês | MEDLINE | ID: mdl-37241535

RESUMO

Developing small-scale continuum catheter robots with inherent soft bodies and high adaptability to different environments holds great promise for biomedical engineering applications. However, current reports indicate that these robots meet challenges when it comes to quick and flexible fabrication with simpler processing components. Herein, we report a millimeter-scale magnetic-polymer-based modular continuum catheter robot (MMCCR) that is capable of performing multifarious bending through a fast and general modular fabrication strategy. By preprogramming the magnetization directions of two types of simple magnetic units, the assembled MMCCR with three discrete magnetic sections could be transformed from a single curvature pose with a large tender angle to a multicurvature S shape in the applied magnetic field. Through static and dynamic deformation analyses for MMCCRs, high adaptability to varied confined spaces can be predicted. By employing a bronchial tree phantom, the proposed MMCCRs demonstrated their capability to adaptively access different channels, even those with challenging geometries that require large bending angles and unique S-shaped contours. The proposed MMCCRs and the fabrication strategy shine new light on the design and development of magnetic continuum robots with versatile deformation styles, which would further enrich broad potential applications in biomedical engineering.

15.
J Funct Biomater ; 14(4)2023 Apr 14.
Artigo em Inglês | MEDLINE | ID: mdl-37103310

RESUMO

BACKGROUND: Autogenous tooth bone graft material (AutoBT) has been advocated as a bone substitute when conducting alveolar ridge preservation. This study is aimed at using a radiomics approach in order to evaluate and testify whether AutoBT can stimulate bone growth during socket preservation in severe periodontal cases. MATERIALS AND METHODS: For this study, 25 cases with severe periodontal diseases were selected. The patients' AutoBTs were inserted into the extraction sockets and covered with Bio-Gide® collagen membranes. 3D CBCT scans and 2D X-rays were taken of the patients before surgery and after 6 months post-surgery. For the retrospective radiomics analysis, the maxillary and mandibular images were compared in different groups. Maxillary bone height was analyzed at the buccal, middle, and palatal crest sites, while the mandibular bone height was compared at the buccal, center, and lingual crest sites. RESULTS: In the maxilla, the alveolar height was increased by -2.15 ± 2.90 mm at the buccal crest; -2.45 ± 2.36 mm at the center of the socket, and -1.62 ± 3.19 mm at the palatal crest, while the height of the buccal crest was increased by 0.19 ± 3.52 mm, and the height at the center of the socket was increased by -0.70 ± 2.71 mm in the mandible. The three-dimensional radiomics analysis demonstrated significant bone growth in the local alveolar height and high density. CONCLUSION: Based on clinical radiomics analysis, AutoBT could be used as an alternative bone material in socket preservation after tooth extraction in patients with severe periodontitis.

16.
Biosens Bioelectron ; 206: 114124, 2022 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-35272215

RESUMO

Immunotherapy using CAR-T cells is a new technological paradigm for cancer treatment. To avoid severe side effects and tumor escape variants observed for conventional CAR-T cells approach, adaptor CAR technologies are under development, where intermediate target modules redirect immune cells against cancer. In this work, silicon nanowire field-effect transistors are used to develop target modules for an optimized CAR-T cell operation. Focusing on a library of seven variants of E5B9 peptide that is used as CAR targeting epitope, we performed multiplexed binding tests using nanosensor chips. These peptides had been immobilized onto the sensor to compare the transistor signals upon titration with anti-La 5B9 antibodies. The correlation of binding affinities and sensor sensitivities enabled a selection of candidates for the interaction between CAR and target modules. An extremely low detection limit was observed for the sensor, down to femtomolar concentration, outperforming the current assay of the same purpose. Finally, the CAR T-cells redirection capability of selected peptides in target modules was proven successful in an in-vitro cytotoxicity assay. Our results open the perspective for the nanosensors to go beyond the early diagnostics in clinical cancer research towards developing and monitoring immunotherapeutic treatment, where the quantitative analysis with the standard techniques is limited.


Assuntos
Técnicas Biossensoriais , Nanofios , Imunoterapia , Imunoterapia Adotiva/métodos , Linfócitos T
17.
Front Microbiol ; 12: 660901, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34025614

RESUMO

Viruses have evolved diverse strategies to manipulate cellular signaling pathways in order to promote infection and/or persistence. Human cytomegalovirus (HCMV) possesses a number of unique properties that allow the virus to alter cellular events required for infection of a diverse array of host cell types and long-term persistence. Of specific importance is infection of bone marrow derived and myeloid lineage cells, such as peripheral blood monocytes and CD34+ hematopoietic progenitor cells (HPCs) because of their essential role in dissemination of the virus and for the establishment of latency. Viral induced signaling through the Epidermal Growth Factor Receptor (EGFR) and other receptors such as integrins are key control points for viral-induced cellular changes and productive and latent infection in host organ systems. This review will explore the current understanding of HCMV strategies utilized to hijack cellular signaling pathways, such as EGFR, to promote the wide-spread dissemination and the classic life-long herpesvirus persistence.

18.
Proteomics ; 10(8): 1699-715, 2010 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-20186754

RESUMO

Orientia tsutsugamushi, an obligate intracellular bacterium, is the causative agent of Scrub typhus. The control mechanisms for bacterial gene expression are largely unknown. Here, the global gene expression of O. tsutsugamushi within eukaryotic cells was examined using a microarray and proteomic approaches for the first time. These approaches identified 643 genes, corresponding to approximately 30% of the genes encoded in the genome. The majority of expressed genes belonged to several functional categories including protein translation, protein processing/secretion, and replication/repair. We also searched the conserved sequence blocks (CSBs) in the O. tsutsugamushi genome which is unique in that up to 40% of its genome consists of dispersed repeated sequences. Although extensive shuffling of genomic sequences was observed between two different strains, 204 CSBs, covering 48% of the genome, were identified. When combining the data of CSBs and global gene expression, the CSBs correlates well with the location of expressed genes, suggesting the functional conservation between gene expression and genomic location. Finally, we compared the gene expression of the bacteria-infected fibroblasts and macrophages using microarray analysis. Some major changes were the downregulation of genes involved in translation, protein processing and secretion, which correlated with the reduction in bacterial translation rates and growth within macrophages.


Assuntos
Orientia tsutsugamushi/genética , Animais , Linhagem Celular , Sequência Conservada , Fibroblastos/química , Fibroblastos/metabolismo , Perfilação da Expressão Gênica , Genoma Bacteriano , Macrófagos/química , Macrófagos/metabolismo , Camundongos , Proteoma , RNA Mensageiro/genética
19.
PLoS Pathog ; 4(11): e1000209, 2008 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-19023411

RESUMO

Lipid rafts are membrane microdomains that function as platforms for signal transduction and membrane trafficking. Tyrosine kinase interacting protein (Tip) of T lymphotropic Herpesvirus saimiri (HVS) is targeted to lipid rafts in T cells and downregulates TCR and CD4 surface expression. Here, we report that the membrane-proximal amphipathic helix preceding Tip's transmembrane (TM) domain mediates lipid raft localization and membrane deformation. In turn, this motif directs Tip's lysosomal trafficking and selective TCR downregulation. The amphipathic helix binds to the negatively charged lipids and induces liposome tubulation, the TM domain mediates oligomerization, and cooperation of the membrane-proximal helix with the TM domain is sufficient for localization to lipid rafts and lysosomal compartments, especially the mutivesicular bodies. These findings suggest that the membrane-proximal amphipathic helix and TM domain provide HVS Tip with the unique ability to deform the cellular membranes in lipid rafts and to downregulate TCRs potentially through MVB formation.


Assuntos
Membrana Celular/virologia , Herpesvirus Saimiriíneo 2/enzimologia , Fosfoproteínas/química , Fosfoproteínas/fisiologia , Receptores de Antígenos de Linfócitos T/metabolismo , Linfócitos T/virologia , Proteínas Virais/química , Proteínas Virais/fisiologia , Antígenos CD4 , Membrana Celular/ultraestrutura , Regulação para Baixo , Humanos , Células Jurkat , Lipídeos , Lisossomos , Microdomínios da Membrana/metabolismo , Microdomínios da Membrana/virologia , Fosfoproteínas/metabolismo , Estrutura Secundária de Proteína , Linfócitos T/ultraestrutura , Proteínas Virais/metabolismo
20.
Chin Med ; 15: 31, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32256687

RESUMO

BACKGROUND: Flavonoids in Chinese Medicine have been proven in animal studies that could aid in osteogenesis and bone formation. However, there is no consented mechanism for how these phytochemicals action on the bone-forming osteoblasts, and henceforth the prediction model of chemical screening for this specific biochemical function has not been established. The purpose of this study was to develop a novel selection and effective approach of flavonoids on the prediction of bone-forming ability via osteoblastic voltage-gated calcium (CaV) activation and inhibition using molecular modelling technique. METHOD: Quantitative structure-activity relationship (QSAR) in supervised maching-learning approach is applied in this study to predict the behavioral manifestations of flavonoids in the CaV channels, and developing statistical correlation between the biochemical features and the behavioral manifestations of 24 compounds (Training set: Kaempferol, Taxifolin, Daidzein, Morin, Scutellarein, Quercetin, Apigenin, Myricetin, Tamarixetin, Rutin, Genistein, 5,7,2'-Trihydroxyflavone, Baicalein, Luteolin, Galangin, Chrysin, Isorhamnetin, Naringin, 3-Methyl galangin, Resokaempferol; test set: 5-Hydroxyflavone, 3,6,4'-Trihydroxyflavone, 3,4'-Dihydroxyflavone and Naringenin). Based on statistical algorithm, QSAR provides a reasonable basis for establishing a predictive correlation model by a variety of molecular descriptors that are able to identify as well as analyse the biochemical features of flavonoids that engaged in activating or inhibiting the CaV channels for osteoblasts. RESULTS: The model has shown these flavonoids have high activating effects on CaV channel for osteogenesis. In addition, scutellarein was ranked the highest among the screened flavonoids, and other lower ranked compounds, such as daidzein, quercetin, genistein and naringin, have shown the same descending order as previous animal studies. CONCLUSION: This predictive modelling study has confirmed and validated the biochemical activity of the flavonoids in the osteoblastic CaV activation.

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