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1.
STAR Protoc ; 4(4): 102735, 2023 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-37991921

RESUMO

Primary human lung organoid-derived air-liquid interface (ALI) cultures serve as a physiologically relevant model to study human airway epithelium in vitro. Here, we present a protocol for establishing these cultures from cryopreserved human lung tissue. We describe steps for lung tissue cryostorage, tissue dissociation, lung epithelial organoid generation, and ALI culture differentiation. We also include quality control steps and technical readouts for monitoring virus response. This protocol demonstrates severe acute respiratory syndrome coronavirus 2 infection in these cultures as an example of their utility. For complete details on the use and execution of this protocol, please refer to Diana Cadena Castaneda et al. (2023).1.


Assuntos
Células Epiteliais , Pulmão , Humanos , Células Cultivadas , Organoides
2.
Nat Immunol ; 22(4): 497-509, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33790474

RESUMO

Classic major histocompatibility complex class I (MHC-I) presentation relies on shuttling cytosolic peptides into the endoplasmic reticulum (ER) by the transporter associated with antigen processing (TAP). Viruses disable TAP to block MHC-I presentation and evade cytotoxic CD8+ T cells. Priming CD8+ T cells against these viruses is thought to rely solely on cross-presentation by uninfected TAP-functional dendritic cells. We found that protective CD8+ T cells could be mobilized during viral infection even when TAP was absent in all hematopoietic cells. TAP blockade depleted the endosomal recycling compartment of MHC-I molecules and, as such, impaired Toll-like receptor-regulated cross-presentation. Instead, MHC-I molecules accumulated in the ER-Golgi intermediate compartment (ERGIC), sequestered away from Toll-like receptor control, and coopted ER-SNARE Sec22b-mediated vesicular traffic to intersect with internalized antigen and rescue cross-presentation. Thus, when classic MHC-I presentation and endosomal recycling compartment-dependent cross-presentation are impaired in dendritic cells, cell-autonomous noncanonical cross-presentation relying on ERGIC-derived MHC-I counters TAP dysfunction to nevertheless mediate CD8+ T cell priming.


Assuntos
Membro 2 da Subfamília B de Transportadores de Cassetes de Ligação de ATP/metabolismo , Transportadores de Cassetes de Ligação de ATP/metabolismo , Linfócitos T CD8-Positivos/imunologia , Apresentação Cruzada , Células Dendríticas/imunologia , Antígenos de Histocompatibilidade Classe I/imunologia , Vírus da Influenza A/imunologia , Infecções por Orthomyxoviridae/imunologia , Infecções por Orthomyxoviridae/metabolismo , Infecções por Orthomyxoviridae/virologia , Membro 2 da Subfamília B de Transportadores de Cassetes de Ligação de ATP/genética , Transportadores de Cassetes de Ligação de ATP/genética , Animais , Linfócitos T CD8-Positivos/metabolismo , Linfócitos T CD8-Positivos/virologia , Proliferação de Células , Células Cultivadas , Técnicas de Cocultura , Células Dendríticas/metabolismo , Células Dendríticas/virologia , Modelos Animais de Doenças , Retículo Endoplasmático/imunologia , Retículo Endoplasmático/metabolismo , Retículo Endoplasmático/virologia , Feminino , Complexo de Golgi/imunologia , Complexo de Golgi/metabolismo , Complexo de Golgi/virologia , Antígenos de Histocompatibilidade Classe I/metabolismo , Interações Hospedeiro-Patógeno , Humanos , Vírus da Influenza A/patogenicidade , Ativação Linfocitária , Masculino , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Knockout , Infecções por Orthomyxoviridae/genética
3.
bioRxiv ; 2020 Oct 23.
Artigo em Inglês | MEDLINE | ID: mdl-33106810

RESUMO

The search for vaccines that protect from severe morbidity and mortality as a result of infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the virus that causes coronavirus disease 2019 (COVID-19) is a race against the clock and the virus. Several vaccine candidates are currently being tested in the clinic. Inactivated virus and recombinant protein vaccines can be safe options but may require adjuvants to induce robust immune responses efficiently. In this work we describe the use of a novel amphiphilic imidazoquinoline (IMDQ-PEG-CHOL) TLR7/8 adjuvant, consisting of an imidazoquinoline conjugated to the chain end of a cholesterol-poly(ethylene glycol) macromolecular amphiphile). This amphiphile is water soluble and exhibits massive translocation to lymph nodes upon local administration, likely through binding to albumin. IMDQ-PEG-CHOL is used to induce a protective immune response against SARS-CoV-2 after single vaccination with trimeric recombinant SARS-CoV-2 spike protein in the BALB/c mouse model. Inclusion of amphiphilic IMDQ-PEG-CHOL in the SARS-CoV-2 spike vaccine formulation resulted in enhanced immune cell recruitment and activation in the draining lymph node. IMDQ-PEG-CHOL has a better safety profile compared to native soluble IMDQ as the former induces a more localized immune response upon local injection, preventing systemic inflammation. Moreover, IMDQ-PEG-CHOL adjuvanted vaccine induced enhanced ELISA and in vitro microneutralization titers, and a more balanced IgG2a/IgG1 response. To correlate vaccine responses with control of virus replication in vivo, vaccinated mice were challenged with SARS-CoV-2 virus after being sensitized by intranasal adenovirus-mediated expression of the human angiotensin converting enzyme 2 (ACE2) gene. Animals vaccinated with trimeric recombinant spike protein vaccine without adjuvant had lung virus titers comparable to non-vaccinated control mice, whereas animals vaccinated with IMDQ-PEG-CHOL-adjuvanted vaccine controlled viral replication and infectious viruses could not be recovered from their lungs at day 4 post infection. In order to test whether IMDQ-PEG-CHOL could also be used to adjuvant vaccines currently licensed for use in humans, proof of concept was also provided by using the same IMDQ-PEG-CHOL to adjuvant human quadrivalent inactivated influenza virus split vaccine, which resulted in enhanced hemagglutination inhibition titers and a more balanced IgG2a/IgG1 antibody response. Enhanced influenza vaccine responses correlated with better virus control when mice were given a lethal influenza virus challenge. Our results underscore the potential use of IMDQ-PEG-CHOL as an adjuvant to achieve protection after single immunization with recombinant protein and inactivated virus vaccines against respiratory viruses, such as SARS-CoV-2 and influenza viruses.

4.
Int J Gynecol Cancer ; 30(11): 1791-1797, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-32747410

RESUMO

INTRODUCTION: Sarcopenia is a condition described as the progressive generalized loss of muscle mass and strength. While sarcopenia has been linked with poorer outcomes following a variety of malignancies, its relationship with all gynecological cancer clinical outcomes has, to date, not been evaluated. This review interrogates the concept of sarcopenia as a prognostic tool for oncological outcomes and adverse effects of treatments in all primary gynecological malignancies. METHODS: This systematic review and meta-analysis was performed in accordance with the Preferred Reporting Items for Systematic reviews and Meta-Analysis guidelines, searching PubMed, Embase, and CINAHL without date or language restriction for studies reporting on sarcopenia and gynecological malignancies. Random effects meta-analysis models were used to determine the effects of sarcopenia on progression-free survival, overall survival, and treatment-related adverse events. RESULTS: Data were analyzed from 13 studies, including 2446 patients (range 60-323) with ovarian cancer (n=1381), endometrial cancer (n=354), or cervical cancer (n=481). Sarcopenia was associated with lower progression-free survival (HR 1.69, 95% CI 1.03 to 2.76), overall survival (HR 1.33, 95% CI 1.08 to 1.64), and no increase in adverse events (HR 1.28, 95% CI 0.69 to 2.40). The risk of bias of the studies was mostly rated unclear, and Begg's and Egger's test revealed a potential publication bias for progression-free survival and overall survval, although the HRs remained significant when adjusting for it. CONCLUSION: Sarcopenia is associated with worse progression-free survival and overall survival in gynecological oncology malignancies. Further research is warranted to validate these findings in larger and prospective samples using standardized methodology and to examine if an intervention could reverse its effect in gynecological oncology trials.


Assuntos
Neoplasias do Endométrio/mortalidade , Neoplasias Ovarianas/mortalidade , Sarcopenia/epidemiologia , Neoplasias do Colo do Útero/mortalidade , Adulto , Idoso , Idoso de 80 Anos ou mais , Progressão da Doença , Intervalo Livre de Doença , Feminino , Humanos , Pessoa de Meia-Idade , Intervalo Livre de Progressão
5.
Nature ; 586(7827): 113-119, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32707573

RESUMO

The emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in 2019 has triggered an ongoing global pandemic of the severe pneumonia-like disease coronavirus disease 2019 (COVID-19)1. The development of a vaccine is likely to take at least 12-18 months, and the typical timeline for approval of a new antiviral therapeutic agent can exceed 10 years. Thus, repurposing of known drugs could substantially accelerate the deployment of new therapies for COVID-19. Here we profiled a library of drugs encompassing approximately 12,000 clinical-stage or Food and Drug Administration (FDA)-approved small molecules to identify candidate therapeutic drugs for COVID-19. We report the identification of 100 molecules that inhibit viral replication of SARS-CoV-2, including 21 drugs that exhibit dose-response relationships. Of these, thirteen were found to harbour effective concentrations commensurate with probable achievable therapeutic doses in patients, including the PIKfyve kinase inhibitor apilimod2-4 and the cysteine protease inhibitors MDL-28170, Z LVG CHN2, VBY-825 and ONO 5334. Notably, MDL-28170, ONO 5334 and apilimod were found to antagonize viral replication in human pneumocyte-like cells derived from induced pluripotent stem cells, and apilimod also demonstrated antiviral efficacy in a primary human lung explant model. Since most of the molecules identified in this study have already advanced into the clinic, their known pharmacological and human safety profiles will enable accelerated preclinical and clinical evaluation of these drugs for the treatment of COVID-19.


Assuntos
Antivirais/análise , Antivirais/farmacologia , Betacoronavirus/efeitos dos fármacos , Infecções por Coronavirus/tratamento farmacológico , Infecções por Coronavirus/virologia , Avaliação Pré-Clínica de Medicamentos , Reposicionamento de Medicamentos , Pneumonia Viral/tratamento farmacológico , Pneumonia Viral/virologia , Monofosfato de Adenosina/análogos & derivados , Monofosfato de Adenosina/farmacologia , Alanina/análogos & derivados , Alanina/farmacologia , Células Epiteliais Alveolares/citologia , Células Epiteliais Alveolares/efeitos dos fármacos , Betacoronavirus/crescimento & desenvolvimento , COVID-19 , Linhagem Celular , Inibidores de Cisteína Proteinase/análise , Inibidores de Cisteína Proteinase/farmacologia , Relação Dose-Resposta a Droga , Sinergismo Farmacológico , Regulação da Expressão Gênica/efeitos dos fármacos , Humanos , Hidrazonas , Células-Tronco Pluripotentes Induzidas/citologia , Modelos Biológicos , Morfolinas/análise , Morfolinas/farmacologia , Pandemias , Pirimidinas , Reprodutibilidade dos Testes , SARS-CoV-2 , Bibliotecas de Moléculas Pequenas/análise , Bibliotecas de Moléculas Pequenas/farmacologia , Triazinas/análise , Triazinas/farmacologia , Internalização do Vírus/efeitos dos fármacos , Replicação Viral/efeitos dos fármacos , Tratamento Farmacológico da COVID-19
6.
J Virol ; 93(14)2019 07 15.
Artigo em Inglês | MEDLINE | ID: mdl-31043537

RESUMO

The mosquito-borne Zika virus (ZIKV) has been causing epidemic outbreaks on a global scale. Virus infection can result in severe disease in humans, including microcephaly in newborns and Guillain-Barré syndrome in adults. Here, we characterized monoclonal antibodies isolated from a patient with an active Zika virus infection that potently neutralized virus infection in Vero cells at the nanogram-per-milliliter range. In addition, these antibodies enhanced internalization of virions into human leukemia K562 cells in vitro, indicating their possible ability to cause antibody-dependent enhancement of disease. Escape variants of the ZIKV MR766 strain to a potently neutralizing antibody, AC10, exhibited an amino acid substitution at residue S368 in the lateral ridge region of the envelope protein. Analysis of publicly availably ZIKV sequences revealed the S368 site to be conserved among the vast majority (97.6%) of circulating strains. We validated the importance of this residue by engineering a recombinant virus with an S368R point mutation that was unable to be fully neutralized by AC10. Four out of the 12 monoclonal antibodies tested were also unable to neutralize the virus with the S368R mutation, suggesting this region to be an important immunogenic epitope during human infection. Last, a time-of-addition infection assay further validated the escape variant and showed that all monoclonal antibodies inhibited virus binding to the cell surface. Thus, the present study demonstrates that the lateral ridge region of the envelope protein is likely an immunodominant, neutralizing epitope.IMPORTANCE Zika virus (ZIKV) is a global health threat causing severe disease in humans, including microcephaly in newborns and Guillain-Barré syndrome in adults. Here, we analyzed the human monoclonal antibody response to acute ZIKV infection and found that neutralizing antibodies could not elicit Fc-mediated immune effector functions but could potentiate antibody-dependent enhancement of disease. We further identified critical epitopes involved with neutralization by generating and characterizing escape variants by whole-genome sequencing. We demonstrate that the lateral ridge region, particularly the S368 amino acid site, is critical for neutralization by domain III-specific antibodies.


Assuntos
Anticorpos Monoclonais/imunologia , Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais , Evasão da Resposta Imune , Mutação Puntual , Proteínas do Envelope Viral , Zika virus , Substituição de Aminoácidos , Anticorpos Antivirais/genética , Anticorpos Antivirais/imunologia , Células HEK293 , Humanos , Evasão da Resposta Imune/genética , Evasão da Resposta Imune/imunologia , Proteínas do Envelope Viral/genética , Proteínas do Envelope Viral/imunologia , Zika virus/genética , Zika virus/imunologia
7.
Nat Immunol ; 18(4): 464-473, 2017 04.
Artigo em Inglês | MEDLINE | ID: mdl-28192418

RESUMO

Infection with influenza virus induces antibodies to the viral surface glycoproteins hemagglutinin and neuraminidase, and these responses can be broadly protective. To assess the breadth and magnitude of antibody responses, we sequentially infected mice, guinea pigs and ferrets with divergent H1N1 or H3N2 subtypes of influenza virus. We measured antibody responses by ELISA of an extensive panel of recombinant glycoproteins representing the viral diversity in nature. Guinea pigs developed high titers of broadly cross-reactive antibodies; mice and ferrets exhibited narrower humoral responses. Then, we compared antibody responses after infection of humans with influenza virus H1N1 or H3N2 and found markedly broad responses and cogent evidence for 'original antigenic sin'. This work will inform the design of universal vaccines against influenza virus and can guide pandemic-preparedness efforts directed against emerging influenza viruses.


Assuntos
Anticorpos Antivirais/imunologia , Reações Cruzadas/imunologia , Vírus da Influenza A/imunologia , Influenza Humana/imunologia , Infecções por Orthomyxoviridae/imunologia , Proteínas do Envelope Viral/imunologia , Adolescente , Adulto , Fatores Etários , Animais , Análise por Conglomerados , Modelos Animais de Doenças , Ensaio de Imunoadsorção Enzimática , Feminino , Furões , Cobaias , Glicoproteínas de Hemaglutininação de Vírus da Influenza/imunologia , Humanos , Imunoglobulina G/imunologia , Vírus da Influenza A/classificação , Masculino , Camundongos , Pessoa de Meia-Idade , Neuraminidase/imunologia , Proteínas Virais/imunologia , Adulto Jovem
8.
Immunobiology ; 218(2): 255-62, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22698984

RESUMO

Eosinophils are the principal effector cells of allergic inflammation, and hematopoietic cytokine granulocyte macrophage colony-stimulating factor (GM-CSF) is the primary cytokine that activates and prolongs the survival of eosinophils in local inflammatory sites by mediating anti-apoptotic activity in allergic inflammation. To investigate the immunopathological role of microRNA (miRNA) in allergic inflammation, we elucidated the regulatory mechanisms of miRNA on the GM-CSF-mediated in vitro survival in eosinophils. Eosinophils were purified from fresh human peripheral blood buffy coat fraction obtained from adult volunteer using microbead magnetic cell sorting. The apoptosis, viability and phosphorylation of extracellular signal-regulated kinase (ERK) were assessed by flow cytometry, and the expression of miRNA was analyzed using Agilent Human miRNA Microarray with Human miRNA Microarray Version 3 and real time RT-PCR. We have confirmed the increased in vitro viability of GM-CSF-treated eosinophils and upregulated expression of miRNA-21* (miR-21*), a complementary miRNA of miR-21, in GM-CSF-treated eosinophils. The transfection of pre-miR miR-21* precursor molecule could up-regulate the miR-21* expression, subsequently enhance the GM-CSF-activated ERK pathway and reverse the apoptosis of eosinophils, while anti-miR-21* inhibitor could down-regulate the miR-21* expression, suppress the GM-CSF-activated ERK pathway and enhance the apoptosis. Our results should shed light on the potential immunopathological role of miRNA-21* regulating the in vitro apoptosis of eosinophils and development of novel molecular treatment of allergic inflammation.


Assuntos
Eosinófilos/imunologia , Hipersensibilidade/genética , Hipersensibilidade/imunologia , Inflamação/genética , MicroRNAs/metabolismo , Adulto , Apoptose/efeitos dos fármacos , Apoptose/genética , Apoptose/imunologia , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/genética , Microambiente Celular , Eosinófilos/efeitos dos fármacos , Regulação da Expressão Gênica/efeitos dos fármacos , Regulação da Expressão Gênica/imunologia , Fator Estimulador de Colônias de Granulócitos e Macrófagos/farmacologia , Humanos , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Sistema de Sinalização das MAP Quinases/genética , Sistema de Sinalização das MAP Quinases/imunologia , MicroRNAs/genética , Análise em Microsséries , Terapia de Alvo Molecular , Transgenes/genética
9.
PLoS One ; 7(1): e29815, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22272250

RESUMO

BACKGROUND: IL-31 is a pruritogenic cytokine, and IL-33 is an alarmin for damaging inflammation. They together relate to the pathogenesis of atopic dermatitis (AD). Eosinophil infiltration into the inner dermal compartment is a predominant pathological feature of AD. We herein investigated the in vitro inflammatory effects of IL-31 and IL-33 on the activation of human eosinophils and dermal fibroblasts. METHODOLOGY/PRINCIPAL FINDINGS: Receptors, adhesion molecules and signaling molecules were assessed by Western blot or flow cytometry. Chemokines and cytokine were quantitated by multiplex assay. Functional IL-31 receptor component IL-31RA, OSMR-ß and IL-33 receptor component ST2 were constitutively expressed on the surface of eosinophils. Co-culture of eosinophils and fibroblasts significantly induced pro-inflammatory cytokine IL-6 and AD-related chemokines CXCL1, CXCL10, CCL2 and CCL5. Such inductions were further enhanced with IL-31 and IL-33 stimulation. IL-31 and IL-33 could significantly provoke the release of CXCL8 from eosinophils and fibroblasts, respectively, which was further enhanced upon co-culture. In co-culture, eosinophils and fibroblasts were the main source for the release of CCL5, and IL-6, CXCL1, CXCL8, CXCL10 and CCL2, respectively. Direct interaction between eosinophils and fibroblasts was required for CXCL1, CXCL10, CXCL8 and CCL5 release. Cell surface expression of intercellular adhesion molecule-1 on eosinophils and fibroblasts was up-regulated in co-culture upon IL-31 and IL-33 stimulation. The interaction between eosinophils and fibroblasts under IL-31 and IL-33 stimulation differentially activated extracellular signal-regulated kinase, c-Jun N-terminal kinase, p38 mitogen-activated protein kinase, nuclear factor-κB and phosphatidylinositol 3-kinase-Akt pathways. Using specific signaling molecule inhibitors, the differential induction of IL-31 and IL-33-mediated release of cytokines and chemokines such as IL-6 and CXCL8 from co-culture should be related to their distinct activation profile of intracellular signaling pathways. CONCLUSIONS/SIGNIFICANCE: The above findings suggest a crucial immunopathological role of IL-31 and IL-33 in AD through the activation of eosinophils-fibroblasts interaction via differential intracellular signaling mechanisms.


Assuntos
Comunicação Celular/efeitos dos fármacos , Eosinófilos/efeitos dos fármacos , Fibroblastos/efeitos dos fármacos , Interleucinas/farmacologia , Western Blotting , Comunicação Celular/imunologia , Células Cultivadas , Quimiocina CCL2/imunologia , Quimiocina CCL2/metabolismo , Quimiocina CCL5/imunologia , Quimiocina CCL5/metabolismo , Quimiocina CXCL1/imunologia , Quimiocina CXCL1/metabolismo , Quimiocina CXCL10/imunologia , Quimiocina CXCL10/metabolismo , Técnicas de Cocultura , Dermatite Atópica/imunologia , Dermatite Atópica/metabolismo , Derme/citologia , Eosinófilos/imunologia , Eosinófilos/metabolismo , Fibroblastos/imunologia , Fibroblastos/metabolismo , Citometria de Fluxo , Humanos , Proteína 1 Semelhante a Receptor de Interleucina-1 , Interleucina-33 , Interleucina-6/imunologia , Interleucina-6/metabolismo , Interleucina-8/imunologia , Interleucina-8/metabolismo , Interleucinas/genética , Interleucinas/imunologia , Receptores de Superfície Celular/imunologia , Receptores de Superfície Celular/metabolismo , Receptores de Interleucina/imunologia , Receptores de Interleucina/metabolismo , Proteínas Recombinantes/imunologia , Proteínas Recombinantes/farmacologia
10.
Nanomedicine (Lond) ; 4(3): 277-90, 2009 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-19331537

RESUMO

AIM: Toxicity of nanoparticles developed for biomedical applications is extensively debated as no uniform guidelines are available for studying nanomaterial safety, resulting in conflicting data obtained from different cell types. This study demonstrates the varied toxicity of a selected type of nanoparticle, cadmium telluride quantum dots (QDs), in three increasingly complex cell models of the peripheral nervous system. MATERIALS & METHODS: QD-induced cytotoxicity was assessed via cell viability assays and biomarkers of subcellular damage in PC12 cells and mixed primary dispersed dorsal root ganglia (DRG) cultures. Morphological analysis of neurite outgrowth was used to determine the viability of axotomized DRG explant cultures. RESULTS & DISCUSSION: Cadmium telluride QDs and their core metals exert different degrees of toxicity in the three cell models, the primary dispersed DRGs being the most susceptible. alpha-lipoic acid is an effective, multimodal, cytoprotective agent that can act as an antioxidant, metal chelator and QD-surface modifier in these cell systems. CONCLUSION: Complex multicellular model systems, along with homogenous cell models, should be utilized in standard screening and monitoring procedures for evaluating nanomaterial safety.


Assuntos
Compostos de Cádmio/toxicidade , Citoproteção , Gânglios Espinais/citologia , Pontos Quânticos , Telúrio/toxicidade , Ácido Tióctico/farmacologia , Animais , Antioxidantes/química , Antioxidantes/farmacologia , Compostos de Cádmio/química , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Gânglios Espinais/efeitos dos fármacos , Glutationa/metabolismo , Camundongos , Células PC12 , Ratos , Telúrio/química , Ácido Tióctico/química
11.
J Mol Med (Berl) ; 86(3): 291-302, 2008 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-17965848

RESUMO

The staggering array of nanotechnological products, found in our environment and those applicable in medicine, has stimulated a growing interest in examining their long-term impact on genetic and epigenetic processes. We examined here the epigenomic and genotoxic response to cadmium telluride quantum dots (QDs) in human breast carcinoma cells. QD treatment induced global hypoacetylation implying a global epigenomic response. The ubiquitous responder to genotoxic stress, p53, was activated by QD challenge resulting in translocation of p53, with subsequent upregulation of downstream targets Puma and Noxa. Consequential decrease in cell viability was in part prevented by the p53 inhibitor pifithrin-alpha, suggesting that p53 translocation contributes to QD-induced cytotoxicity. These findings suggest three levels of nanoparticle-induced cellular changes: non-genomic, genomic and epigenetic. Epigenetic changes may have long-term effects on gene expression programming long after the initial signal has been removed, and if these changes remain undetected, it could lead to long-term untoward effects in biological systems. These studies suggest that aside from genotoxic effects, nanoparticles could cause more subtle epigenetic changes which merit thorough examination of environmental nanoparticles and novel candidate nanomaterials for medical applications.


Assuntos
Neoplasias da Mama/genética , Dano ao DNA , Epigênese Genética , Pontos Quânticos , Acetilação , Animais , Proteínas Reguladoras de Apoptose/genética , Proteínas Reguladoras de Apoptose/metabolismo , Linhagem Celular Tumoral , Núcleo Celular/metabolismo , Núcleo Celular/ultraestrutura , Cromatina/metabolismo , Cromatina/ultraestrutura , Regulação Neoplásica da Expressão Gênica , Histonas/metabolismo , Humanos , Mitocôndrias/ultraestrutura , Modelos Biológicos , Células PC12 , Fosforilação , Processamento de Proteína Pós-Traducional , Transporte Proteico , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Ratos , Proteína Supressora de Tumor p53/metabolismo
12.
J Nanobiotechnology ; 5: 1, 2007 Feb 12.
Artigo em Inglês | MEDLINE | ID: mdl-17295922

RESUMO

BACKGROUND: Neuroblastoma, a frequently occurring solid tumour in children, remains a therapeutic challenge as existing imaging tools are inadequate for proper and accurate diagnosis, resulting in treatment failures. Nanoparticles have recently been introduced to the field of cancer research and promise remarkable improvements in diagnostics, targeting and drug delivery. Among these nanoparticles, quantum dots (QDs) are highly appealing due to their manipulatable surfaces, yielding multifunctional QDs applicable in different biological models. The biocompatibility of these QDs, however, remains questionable. RESULTS: We show here that QD surface modifications with N-acetylcysteine (NAC) alter QD physical and biological properties. In human neuroblastoma (SH-SY5Y) cells, NAC modified QDs were internalized to a lesser extent and were less cytotoxic than unmodified QDs. Cytotoxicity was correlated with Fas upregulation on the surface of treated cells. Alongside the increased expression of Fas, QD treated cells had increased membrane lipid peroxidation, as measured by the fluorescent BODIPY-C11 dye. Moreover, peroxidized lipids were detected at the mitochondrial level, contributing to the impairment of mitochondrial functions as shown by the MTT reduction assay and imaged with confocal microscopy using the fluorescent JC-1 dye. CONCLUSION: QD core and surface compositions, as well as QD stability, all influence nanoparticle internalization and the consequent cytotoxicity. Cadmium telluride QD-induced toxicity involves the upregulation of the Fas receptor and lipid peroxidation, leading to impaired neuroblastoma cell functions. Further improvements of nanoparticles and our understanding of the underlying mechanisms of QD-toxicity are critical for the development of new nanotherapeutics or diagnostics in nano-oncology.

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