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1.
Bioorg Med Chem ; 93: 117443, 2023 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-37634417

RESUMO

Photodynamic therapy (PDT) is an established anticancer treatment that combines the use of a photosensitiser (PS) and a light source of a specific wavelength for the generation of reactive oxygen species (ROS) that are toxic to the tumour cells. Foscan® (mTHPC) is a clinically-approved chlorin used for the PDT treatment of advanced head and neck, prostate and pancreatic cancers but is characterized by being photochemically unstable and associated with prolonged skin photosensitivity. Herein, we report the synthesis of new 4,5,6,7-tetrahydropyrazolo[1,5-a]pyridine-fused chlorins, having the meso-tetra(3-hydroxyphenyl)macrocycle core of mTHPC, by exploring the [8π + 2π] cycloaddition of a meso-tetra(3-hydroxyphenyl)porphyrin derivative with diazafulvenium methides. These chlorins have photochemical properties similar to Foscan® but are much more photostable. Among the novel compounds, two chlorins with a hydroxymethyl group and its azide derivative present in the 4,5,6,7-tetrahydropyrazolo[1,5-a]pyridine-fused system, are promising photodynamic agents with activity in the 100 nM range against triple-negative breast cancer cells and, in the case of azidomethyl chlorin, a safer phototherapeutic index compared to Foscan®.


Assuntos
Neoplasias Pancreáticas , Fotoquimioterapia , Porfirinas , Masculino , Humanos , Porfirinas/farmacologia , Piridinas
2.
J Neurochem ; 163(2): 74-93, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-35950924

RESUMO

Microglia are tissue-resident macrophages responsible for the surveillance, neuronal support, and immune defense of the brain parenchyma. Recently, the role played by microglia in the formation and function of neuronal circuits has garnered substantial attention. During development, microglia have been shown to engulf neuronal precursors and participate in pruning mechanisms while, in the mature brain, they influence synaptic signaling, provide trophic support and shape synaptic plasticity. Recently, studies have unveiled different microglial characteristics associated with specific brain regions. This emerging view suggests that the maturation and function of distinct neuronal circuits may be potentially associated with the molecular identity microglia adopts across the brain. Here, we review and summarize the known role of these cells in the thalamus, hippocampus, cortex, and cerebellum. We focus on in vivo studies to highlight the characteristics of microglia that may be important in the remodeling of these neuronal circuits and in relation to neurodevelopmental and neuropsychiatric disorders.


Assuntos
Microglia , Plasticidade Neuronal , Encéfalo/fisiologia , Hipocampo/fisiologia , Microglia/fisiologia , Plasticidade Neuronal/fisiologia , Neurônios , Sinapses/fisiologia
3.
Molecules ; 27(4)2022 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-35209094

RESUMO

Diels-Alder cycloaddition reaction is one of the most powerful strategies for the construction of six-membered carbocyclic and heterocyclic systems, in most cases with high regio- and stereoselectivity. In this review, an insight into the most relevant advances on sustainable Diels-Alder reactions since 2010 is provided. Various environmentally benign solvent systems are discussed, namely bio-based derived solvents (such as glycerol and gluconic acid), polyethylene glycol, deep eutectic solvents, supercritical carbon dioxide, water and water-based aqueous systems. Issues such as method's scope, efficiency, selectivity and reaction mechanism, as well as sustainability, advantages and limitations of these reaction media, are addressed.

4.
Clin Oral Investig ; 25(9): 5317-5329, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-33630165

RESUMO

OBJECTIVES: To compare the regenerative properties of human stem cells of the apical papilla (SCAPs) embedded in a platelet-rich plasma (PRP) scaffold, when implanted in vivo using an organotypic model composed of human root segments, with or without the presence of the bioactive cements - ProRoot MTA or Biodentine. MATERIAL AND METHODS: SCAPs were isolated from third molars with incomplete rhizogenesis and expanded and characterized in vitro using stem cell and surface markers. The pluripotency of these cells was also assessed using adipogenic, chondrogenic, and osteogenic differentiation protocols. SCAPs together with a scaffold of PRP were added to the root segment lumen and the organotypic model implanted on the dorsal region of immunodeficient rats for a period of 4 months. RESULTS: Presence of SCAPs induced de novo formation of dentin-like and pulp-like tissue. A barrier of either ProRoot MTA or Biodentine did not significantly affect the fraction of sections from roots segments observed to contain deposition of hard material (P > 0.05). However, the area of newly deposited dentin was significantly greater in segments containing a barrier of Biodentine compared with ProRoot MTA (P < 0.001). CONCLUSIONS AND CLINICAL RELEVANCE: SCAPs offer a viable alternative to other dental stem cells (DSCs) in their regenerative properties when enclosed in the microenvironment of human tooth roots. The present study also suggests that the presence of bioactive materials does not hinder or impede the formation of new hard tissues, but the presence of Biodentine may promote greater mineralized tissue deposition.


Assuntos
Osteogênese , Células-Tronco , Animais , Diferenciação Celular , Células Cultivadas , Papila Dentária , Polpa Dentária , Dentina , Humanos , Ratos , Regeneração
5.
Chem Rev ; 118(23): 11324-11352, 2018 12 12.
Artigo em Inglês | MEDLINE | ID: mdl-30495939

RESUMO

This review aims to present the most recent contributions in the chemistry of nitrosoalkenes and azoalkenes, highlighting the chemical behavior that makes them important and versatile building blocks in organic synthesis. These are heterodienes used in the assembly of a variety of heterocyclic systems, spanning from five- to seven-membered heterocycles, as well as for the functionalization of heterocycles.

6.
Hum Mol Genet ; 26(22): 4375-4387, 2017 11 15.
Artigo em Inglês | MEDLINE | ID: mdl-28973155

RESUMO

Glioblastoma (GBM) is a deadly and therapy resistant malignant brain tumour, characterized by an aggressive and diffuse growth pattern, which prevents complete surgical resection. Despite advances in the identification of genomic and molecular alterations that fuel the tumour, average patient survival post-diagnosis remains very low (∼14.6-months). In addition to being highly heterogeneous, GBM tumour cells exhibit high adaptive capacity to targeted molecular therapies owing to an established network of signalling cascades with functional redundancy, which provides them with robust compensatory survival mechanisms. Here, we investigated whether a multimodal strategy combining multitargeted tyrosine kinase inhibitors (MTKIs) and microRNA (miRNA) modulation could overcome the signalling pathway redundancy in GBM and, hence, promote tumour cell death. By performing a high-throughput screening, we identified a myriad of miRNAs, including those belonging to the miR-302-3p/372-3p/373-3p/520-3p family, which coordinately act with the MTKI sunitinib to decrease GBM cell viability. Two members of this family, hsa-miRNA-302a-3p and hsa-miRNA-520 b, were found to modulate the expression of receptor tyrosine kinase mediators (including AKT1, PIK3CA and SOS1) in U87 and DBTRG human GBM cells. Importantly, administration of mimics of these miRNAs with sunitinib or axitinib resulted in decreased tumour cell proliferation and enhanced cell death, whereas no significant effect was observed when coupling miRNA modulation with temozolomide, the first-line drug for GBM therapy. Overall, our results provide evidence that combining the 'horizontal' inhibition of signalling pathways promoted by MTKIs with the 'vertical' inhibition of the downstream signalling cascade promoted by hsa-miR-302a-3p and hsa-miR-520 b constitutes a promising approach towards GBM treatment.


Assuntos
Neoplasias Encefálicas/genética , Neoplasias Encefálicas/terapia , Glioblastoma/genética , Glioblastoma/terapia , MicroRNAs/genética , Inibidores de Proteínas Quinases/farmacologia , Neoplasias Encefálicas/tratamento farmacológico , Neoplasias Encefálicas/metabolismo , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Proliferação de Células/genética , Terapia Combinada , Predisposição Genética para Doença , Glioblastoma/tratamento farmacológico , Glioblastoma/metabolismo , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Humanos , MicroRNAs/metabolismo , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/genética , Transfecção
7.
Biochim Biophys Acta ; 1860(1 Pt A): 28-35, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26434535

RESUMO

BACKGROUND: Overexpression of transferrin receptors (TfRs), which are responsible for the intracellular uptake of ferric transferrin (Tf), has been described in various cancers. Although molecular biology methods allow the identification of different types of receptors in cancer cells, they do not provide features about TfRs internalization, quantification and distribution on cell surface. This information can, however, be accessed by fluorescence techniques. In this work, the quantum dots (QDs)' unique properties were explored to strengthen our understanding of TfRs in cancer cells. METHODS: QDs were conjugated to Tf by covalent coupling and QDs-(Tf) bioconjugates were applied to quantify and evaluate the distribution of TfRs in two human glioblastoma cells lines, U87 and DBTRG-05MG, and also in HeLa cells by using flow cytometry and confocal microscopy. RESULTS: HeLa and DBTRG-05MG cells showed practically the same TfR labeling profile by QDs-(Tf), while U87 cells were less labeled by bioconjugates. Furthermore, inhibition studies demonstrated that QDs-(Tf) were able to label cells with high specificity. CONCLUSIONS: HeLa and DBTRG-05MG cells presented a similar and a higher amount of TfR than U87 cells. Moreover, DBTRG-05MG cells are more efficient in recycling the TfR than the other two cells types. GENERAL SIGNIFICANCE: This is the first study about TfRs in human glioblastoma cells using QDs. This new fluorescent tool can contribute to our understanding of the cancer cell biology and can help in the development of new therapies targeting these receptors.


Assuntos
Neoplasias Encefálicas/química , Glioblastoma/química , Pontos Quânticos , Receptores da Transferrina/análise , Corantes Fluorescentes , Células HeLa , Humanos , Microscopia Confocal
8.
Bioorg Med Chem ; 25(3): 1122-1131, 2017 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-28062194

RESUMO

A novel synthetic approach to bis(indolyl)methanes has been established. Our one-pot synthetic strategy based on two consecutive hetero-Diels-Alder cycloaddition reactions of electrophilic conjugated nitrosoalkenes with indoles was extended to a range of new 1-hydroxyiminomethyl-bis(indolyl)methanes. Furthermore, a similar and broad range approach was applied to the synthesis of previously unknown 1-hydrazonomethyl-bis(indolyl)methanes. The biological evaluation of the new bis(indolyl)methanes as anti-cancer agents was investigated.


Assuntos
Antineoplásicos/farmacologia , Indóis/farmacologia , Metano/farmacologia , Antineoplásicos/síntese química , Antineoplásicos/química , Linhagem Celular , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Reação de Cicloadição , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Indóis/síntese química , Indóis/química , Metano/análogos & derivados , Metano/química , Estrutura Molecular , Estereoisomerismo , Relação Estrutura-Atividade
9.
Hum Mol Genet ; 23(23): 6286-301, 2014 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-24990149

RESUMO

MicroRNAs (miRNAs) have emerged as a class of small, endogenous, regulatory RNAs that exhibit the ability to epigenetically modulate the translation of mRNAs into proteins. This feature enables them to control cell phenotypes and, consequently, modify cell function in a disease context. The role of inflammatory miRNAs in Alzheimer's disease (AD) and their ability to modulate glia responses are now beginning to be explored. In this study, we propose to disclose the functional role of miR-155, one of the most well studied immune-related miRNAs in AD-associated neuroinflammatory events, employing the 3xTg AD animal model. A strong upregulation of miR-155 levels was observed in the brain of 12-month-old 3xTg AD animals. This event occurred simultaneously with an increase of microglia and astrocyte activation, and before the appearance of extracellular Aß aggregates, suggesting that less complex Aß species, such as Aß oligomers may contribute to early neuroinflammation. In addition, we investigated the contribution of miR-155 and the c-Jun transcription factor to the molecular mechanisms that underlie Aß-mediated activation of glial cells. Our results suggest early miR-155 and c-Jun upregulation in the 3xTg AD mice, as well as in Aß-activated microglia and astrocytes, thus contributing to the production of inflammatory mediators such as IL-6 and IFN-ß. This effect is associated with a miR-155-dependent decrease of suppressor of cytokine signaling 1. Furthermore, since c-Jun silencing decreases the levels of miR-155 in Aß-activated microglia and astrocytes, we propose that miR-155 targeting can constitute an interesting and promising approach to control neuroinflammation in AD.


Assuntos
Doença de Alzheimer/patologia , Encéfalo/metabolismo , MicroRNAs/metabolismo , Neurônios/metabolismo , Doença de Alzheimer/imunologia , Doença de Alzheimer/metabolismo , Peptídeos beta-Amiloides/metabolismo , Animais , Astrócitos/metabolismo , Encéfalo/patologia , Linhagem Celular , Inflamação/imunologia , Inflamação/metabolismo , Inflamação/patologia , Proteínas Quinases JNK Ativadas por Mitógeno/metabolismo , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Microglia/metabolismo , Proteína 1 Supressora da Sinalização de Citocina , Proteínas Supressoras da Sinalização de Citocina/metabolismo , Regulação para Cima
10.
J Org Chem ; 81(19): 9028-9036, 2016 10 07.
Artigo em Inglês | MEDLINE | ID: mdl-27606692

RESUMO

(1H-Tetrazol-5-yl)-allenes have been prepared for the first time, and their reactivity toward aziridines explored. Reaction of a (1-benzyl-1H-tetrazol-5-yl)-phosphonium chloride and acyl chlorides in the presence of triethylamine afforded the target allenes via Wittig reaction of the in situ generated phosphorus ylide and ketenes. 1-(1-Benzyl-1H-tetrazol-5-yl)propa-1,2-diene and 3-methyl-, 3-ethyl- and 3-benzyl derivatives undergo microwave-induced formal [3 + 2] cycloaddition with cis-N-benzyl-2-benzoyl-3-phenylaziridine, through C-N bond cleavage, to give selectively tetrasubstituted pyrroles. In contrast, with (1H-tetrazol-5-yl)-allenes bearing bulkier substituents at C-3, such as i-propyl or a tert-butyl, 4-methylenepyrrolidines were obtained exclusively via [3 + 2] cycloaddition of the in situ generated azomethine ylide. The latter allenes also gave 4-methylenepyrrolidines on reacting with cis-2-benzoyl-N-cyclohexyl-3-phenylaziridine, whereas with the other allenes, pyrroles were obtained as major products together with the formation of 4-methylenepyrrolidines. All the studied (1H-tetrazol-5-yl)-allenes reacted with N-benzyl-cis-3-phenylaziridine-2-carboxylate to give the corresponding 4-methylenepyrrolidines exclusively.

11.
Hum Mol Genet ; 22(5): 904-18, 2013 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-23201752

RESUMO

Highly malignant glioblastoma (GBM) is characterized by high genetic heterogeneity and infiltrative brain invasion patterns, and aberrant miRNA expression has been associated with hallmark malignant properties of GBM. The lack of effective GBM treatment options prompted us to investigate whether miRNAs would constitute promising therapeutic targets toward the generation of a gene therapy approach with clinical significance for this disease. Here, we show that microRNA-21 (miR-21) is upregulated and microRNA-128 (miR-128) is downregulated in mouse and human GBM samples, a finding that is corroborated by analysis of a large set of human GBM data from The Cancer Genome Atlas. Moreover, we demonstrate that oligonucleotide-mediated miR-21 silencing in U87 human GBM cells resulted in increased levels of the tumor suppressors PTEN and PDCD4, caspase 3/7 activation and decreased tumor cell proliferation. Cell exposure to pifithrin, an inhibitor of p53 transcriptional activity, reduced the caspase activity associated with decreased miR-21 expression. Finally, we demonstrate for the first time that miR-21 silencing enhances the antitumoral effect of the tyrosine kinase inhibitor sunitinib, whereas no therapeutic benefit is observed when coupling miR-21 silencing with the first-line drug temozolomide. Overall, our results provide evidence that miR-21 is uniformly overexpressed in GBM and constitutes a highly promising target for multimodal therapeutic approaches toward GBM.


Assuntos
Neoplasias Encefálicas/genética , Glioblastoma/genética , Indóis/administração & dosagem , MicroRNAs/genética , Pirróis/administração & dosagem , Inibidores da Angiogênese/administração & dosagem , Animais , Proteínas Reguladoras de Apoptose/genética , Neoplasias Encefálicas/tratamento farmacológico , Neoplasias Encefálicas/patologia , Linhagem Celular Tumoral , Proliferação de Células , Regulação para Baixo , Regulação Neoplásica da Expressão Gênica , Glioblastoma/tratamento farmacológico , Glioblastoma/patologia , Humanos , Camundongos , MicroRNAs/metabolismo , PTEN Fosfo-Hidrolase/genética , Proteínas de Ligação a RNA/genética , Transdução de Sinais , Sunitinibe , Regulação para Cima
12.
Mol Pharm ; 12(3): 716-30, 2015 Mar 02.
Artigo em Inglês | MEDLINE | ID: mdl-25634573

RESUMO

Gene delivery targeting mitochondria has the potential to transform the therapeutic landscape of mitochondrial genetic diseases. Taking advantage of the nonuniversal genetic code used by mitochondria, a plasmid DNA construct able to be specifically expressed in these organelles was designed by including a codon, which codes for an amino acid only if read by the mitochondrial ribosomes. In the present work, gemini surfactants were shown to successfully deliver plasmid DNA to mitochondria. Gemini surfactant-based DNA complexes were taken up by cells through a variety of routes, including endocytic pathways, and showed propensity for inducing membrane destabilization under acidic conditions, thus facilitating cytoplasmic release of DNA. Furthermore, the complexes interacted extensively with lipid membrane models mimicking the composition of the mitochondrial membrane, which predicts a favored interaction of the complexes with mitochondria in the intracellular environment. This work unravels new possibilities for gene therapy toward mitochondrial diseases.


Assuntos
Técnicas de Transferência de Genes , Genes Mitocondriais , Compostos de Amônio Quaternário , Alcenos/química , Polarização de Fluorescência , Expressão Gênica , Proteínas de Fluorescência Verde/biossíntese , Proteínas de Fluorescência Verde/genética , Células HeLa , Humanos , Lipídeos de Membrana/química , Plasmídeos/administração & dosagem , Plasmídeos/genética , Compostos de Amônio Quaternário/química , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/genética , Tensoativos/química
13.
Molecules ; 20(12): 22351-63, 2015 Dec 12.
Artigo em Inglês | MEDLINE | ID: mdl-26703533

RESUMO

The synthesis and reactivity of tetrazol-5-yl-phosphorus ylides towards N-halosuccinimide/TMSN3 reagent systems was explored, opening the way to new haloazidoalkenes bearing a tetrazol-5-yl substituent. These compounds were obtained as single isomers, except in one case. X-ray crystal structures were determined for three derivatives, establishing that the non-classical Wittig reaction leads to the selective synthesis of haloazidoalkenes with (Z)-configuration. The thermolysis of the haloazidoalkenes afforded new 2-halo-2-(tetrazol-5-yl)-2H-azirines in high yields. Thus, the reported synthetic methodologies gave access to important building blocks in organic synthesis, vinyl tetrazoles and 2-halo-2-(tetrazol-5-yl)-2H-azirine derivatives.


Assuntos
Azirinas/química , Tetrazóis/química , Cristalografia por Raios X/métodos , Estrutura Molecular , Estereoisomerismo
14.
Hum Mol Genet ; 21(23): 5118-30, 2012 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-22922228

RESUMO

Glioblastoma (GBM) is a highly heterogeneous type of tumor characterized by genomic and signaling abnormalities affecting pathways involved in control of cell fate, including tumor-suppressor- and growth factor-regulated pathways. An aberrant miRNA expression has been observed in GBM, being associated with impaired cellular functions resulting in malignant transformation, proliferation and invasion. Here, we demonstrate for the first time that platelet-derived growth factor-B (PDGF-B), a potent angiogenic growth factor involved in GBM development and progression, promotes downregulation of pro-oncogenic (miR-21) and anti-oncogenic (miR-128) miRNAs, as well as upregulation/downregulation of several miRNAs involved in GBM pathology. Retrovirally mediated overexpression of PDGF-B in U87 human GBM cells or their prolonged exposure, as well as that of F98 rat glioma cells to this ligand, resulted in decreased miR-21 and miR-128 levels, which was associated with increased cell proliferation. Furthermore, siRNA-mediated PDGF-B silencing led to increased levels of miR-21 and miR-128, while miRNA modulation through overexpression of miR-21 did not alter the levels of PDGF-B. Finally, we demonstrate that modulation of tumor suppressors PTEN and p53 in U87 cells does not affect the decrease in miR-21 levels associated with PDGF-B overexpression. Overall, our findings suggest that, besides its role in inducing GBM tumorigenesis, PDGF-B may enhance tumor proliferation by modulating the expression of oncomiRs and tumor suppressor miRNAs in U87 human GBM cells.


Assuntos
Regulação Neoplásica da Expressão Gênica , Glioblastoma/genética , Glioblastoma/metabolismo , MicroRNAs/genética , Proteínas Proto-Oncogênicas c-sis/metabolismo , Transdução de Sinais , Animais , Linhagem Celular Tumoral , Modelos Animais de Doenças , Regulação para Baixo/genética , Perfilação da Expressão Gênica , Inativação Gênica , Humanos , Camundongos , PTEN Fosfo-Hidrolase/genética , PTEN Fosfo-Hidrolase/metabolismo , Proteínas Proto-Oncogênicas c-sis/genética , Interferência de RNA , Ratos , Células Tumorais Cultivadas , Proteína Supressora de Tumor p53/genética , Proteína Supressora de Tumor p53/metabolismo
15.
Mol Pharm ; 11(3): 819-27, 2014 Mar 03.
Artigo em Inglês | MEDLINE | ID: mdl-24428614

RESUMO

Gene knockdown has emerged as an important tool for cancer gene therapy as well as for viral infections and dominantly inherited genetic disorders. The generation of suitable siRNA delivery systems poses some challenges, namely, to avoid nuclease degradation, to surpass the cytoplasmic membrane, and to release the nucleic acids into the cytosol. Aiming at evaluating the ability of thermoresponsive block copolymers formed by units of N-isopropylacrylamide and of (3-acrylamidopropyl)trimethylammonium chloride to efficiently deliver siRNAs, an extensive study was performed with four different copolymers using a human fibrosarcoma cell line as cell model. The silencing ability and cytotoxicity of the generated copolymer-based siRNA delivery systems were found to be dependent on the cloud point of the polymer, which corresponds to the transition temperature at which the aggregation or precipitation of the polymer molecules becomes thermodynamically more favorable than their solubilization. In the present study, a system capable of delivering siRNAs efficiently, specifically and without presenting relevant cytotoxicity, even in the presence of serum, was developed. Confocal fluorescence experiments showed that the ability of the generated systems to silence the target gene is related to some extent to nucleic acid internalization, being also dependent on polymer/siRNA dissociation at 37 °C. Thus, a delicate balance between nucleic acid internalization and intracellular release must be met in order to reach an ideal knockdown efficiency. The special features and potential for manipulation of the N-isopropylacrylamide-based copolymers make them suitable materials for the design and synthesis of new and promising siRNA delivery systems.


Assuntos
Anticorpos Monoclonais/uso terapêutico , Carcinoma de Células Escamosas/radioterapia , Proliferação de Células/efeitos da radiação , Receptores ErbB/antagonistas & inibidores , Neoplasias de Cabeça e Pescoço/radioterapia , Lutécio/uso terapêutico , Radioimunoterapia , Animais , Anticorpos Monoclonais/farmacocinética , Anticorpos Monoclonais Humanizados/uso terapêutico , Antineoplásicos/uso terapêutico , Carcinoma de Células Escamosas/diagnóstico por imagem , Carcinoma de Células Escamosas/imunologia , Carcinoma de Células Escamosas/metabolismo , Proliferação de Células/efeitos dos fármacos , Cetuximab , Receptores ErbB/imunologia , Feminino , Neoplasias de Cabeça e Pescoço/diagnóstico por imagem , Neoplasias de Cabeça e Pescoço/imunologia , Neoplasias de Cabeça e Pescoço/metabolismo , Humanos , Lutécio/farmacocinética , Camundongos , Camundongos Endogâmicos BALB C , Panitumumabe , Distribuição Tecidual , Tomografia Computadorizada de Emissão de Fóton Único , Ensaios Antitumorais Modelo de Xenoenxerto
16.
Biochim Biophys Acta ; 1818(3): 877-88, 2012 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-22230348

RESUMO

The present work aims to gain insights into the role of peptide-lipid interactions in the mechanisms of cellular internalization and endosomal escape of the S4(13)-PV cell-penetrating peptide, which has been successfully used in our laboratory as a nucleic acid delivery system. A S4(13)-PV analogue, S4(13)-PVscr, displaying a scrambled amino acid sequence, deficient cell internalization and drug delivery inability, was used in this study for comparative purposes. Differential scanning calorimetry, fluorescence polarization and X-ray diffraction at small and wide angles techniques showed that both peptides interacted with anionic membranes composed of phosphatidylglycerol or a mixture of this lipid with phosphatidylethanolamine, increasing the lipid order, shifting the phase transition to higher temperatures and raising the correlation length between the bilayers. However, S4(13)-PVscr, in contrast to the wild-type peptide, did not promote lipid domain segregation and induced the formation of an inverted hexagonal lipid phase instead of a cubic phase in the lipid systems assayed. Electron microscopy showed that, as opposed to S4(13)-PVscr, the wild-type peptide induced the formation of a non-lamellar organization in membranes of HeLa cells. We concluded that lateral phase separation and destabilization of membrane lamellar structure without compromising membrane integrity are on the basis of the lipid-driven and receptor-independent mechanism of cell entry of S4(13)-PV peptide. Overall, our results can contribute to a better understanding of the role of peptide-lipid interactions in the mechanisms of cell-penetrating peptide membrane translocation, helping in the future design of more efficient cell-penetrating peptide-based drug delivery systems.


Assuntos
Membrana Celular/metabolismo , Peptídeos Penetradores de Células/química , Peptídeos Penetradores de Células/farmacocinética , Bicamadas Lipídicas/química , Peptídeos/química , Peptídeos/farmacocinética , Membrana Celular/química , Membrana Celular/ultraestrutura , Peptídeos Penetradores de Células/farmacologia , Sistemas de Liberação de Medicamentos/métodos , Células HeLa , Humanos , Bicamadas Lipídicas/metabolismo , Peptídeos/farmacologia , Fosfatidiletanolaminas/química , Fosfatidiletanolaminas/metabolismo , Fosfatidilgliceróis/química , Fosfatidilgliceróis/metabolismo
17.
Mol Pharm ; 10(7): 2653-66, 2013 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-23697649

RESUMO

The successful application of gene therapy approaches is highly dependent on the efficient delivery of nucleic acids into target cells. In the present study, new peptide-based nonviral systems were developed to enhance plasmid DNA and siRNA delivery, aiming at generating appropriate gene delivery and gene silencing tools for preclinical and clinical application. For this purpose, a new cell-penetrating peptide derived from the wild-type S4(13)-PV peptide was synthesized through the addition of a five-histidine tail to its N-terminus (H5-S4(13)-PV), and its ability to mediate gene expression and gene silencing was evaluated and compared to that of the wild-type peptide. The histidine-enriched peptide, H5-S4(13)-PV, proved to be generally more efficient and less toxic than the wild-type peptide in the delivery of plasmid DNA. In addition, complexes of H5-S4(13)-PV with siRNAs, but not of S4(13)-PV, were efficiently internalized by cells and presented high knockdown activity (63%). Interestingly, systems containing the S4(13)-PV or the H5-S4(13)-PV peptide exhibited superior biological activity when compared to those containing the reverse NLS or scrambled peptides, suggesting that both the cell-penetrating sequence and the NLS of the S4(13)-PV peptide influence the competence of binary and ternary complexes to accomplish nucleic acid delivery. In order to unravel the cancer therapeutic potential of formulations with the histidine-enriched peptide, their efficiency to mediate silencing of the oncogenic protein survivin was evaluated. As opposed to complexes with the wild-type peptide, H5-S4(13)-PV complexes showed the ability to promote a high survivin knockdown at the level of both protein (44%) and mRNA (73%), in HT1080 cells.


Assuntos
Peptídeos Penetradores de Células/química , Western Blotting , Linhagem Celular , Sobrevivência Celular/genética , Sobrevivência Celular/fisiologia , Citometria de Fluxo , Terapia Genética/métodos , Células HeLa , Humanos , Proteínas Inibidoras de Apoptose/genética , Lipossomos/química , Survivina , Transfecção/métodos
18.
Immunology ; 135(1): 73-88, 2012 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22043967

RESUMO

Innate immunity constitutes the first line of defence against both external and endogenous threats in the brain, and microglia cells are considered key mediators of this process. Recent studies have shown that microRNAs (miRNAs) may play a determinant role in the regulation of gene expression during innate immune responses. The major goal of this work was to investigate the contribution of a specific miRNA - miR-155 - to the modulation of the microglia-mediated immune response. For this purpose, in vitro studies were performed in N9 microglia cells to evaluate changes in the levels of this miRNA following microglia activation. A strong up-regulation of miR-155 expression was observed following microglia exposure to lipopolysaccharide, which was consistent with a decrease in the levels of the suppressor of cytokine signalling 1 (SOCS-1) protein, a key inhibitor of the inflammatory process and a predicted target of miR-155. The miR-155 knockdown by anti-miRNA oligonucleotides up-regulated SOCS-1 mRNA and protein levels and significantly decreased the production of nitric oxide and the expression of inflammatory cytokines and inducible nitric oxide synthase. Finally, treatment of neuronal primary cultures with conditioned medium obtained from microglia cells, in which miR-155 was inhibited before cell activation, decreased inflammatory-mediated neuronal cell death. Overall, our results show that miR-155 has a pro-inflammatory role in microglia and is necessary for the progression of the immune response through the modulation of SOCS-1, suggesting that, in a chronic inflammatory context, miR-155 inhibition can have a neuroprotective effect.


Assuntos
Citocinas/imunologia , MicroRNAs/imunologia , Microglia/imunologia , Óxido Nítrico/imunologia , Proteínas Supressoras da Sinalização de Citocina/imunologia , Animais , Células Cultivadas , Citocinas/biossíntese , Regulação para Baixo/efeitos dos fármacos , Lipopolissacarídeos/imunologia , Lipopolissacarídeos/farmacologia , Camundongos , MicroRNAs/biossíntese , Microglia/metabolismo , Óxido Nítrico/biossíntese , Proteína 1 Supressora da Sinalização de Citocina , Regulação para Cima/efeitos dos fármacos
19.
Mech Ageing Dev ; 197: 111512, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-34022277

RESUMO

Among all major organs, the brain is one of the most susceptible to the inexorable effects of aging. Throughout the last decades, several studies in human cohorts and animal models have revealed a plethora of age-related changes in the brain, including reduced neurogenesis, oxidative damage, mitochondrial dysfunction and cell senescence. As the main immune effectors and first responders of the nervous tissue, microglia are at the center of these events. These cells experience irrevocable changes as a result from cumulative exposure to environmental triggers, such as stress, infection and metabolic dysregulation. The age-related immunosenescent phenotype acquired by microglia is characterized by profound modifications in their transcriptomic profile, secretome, morphology and phagocytic activity, which compromise both their housekeeping and defensive functions. As a result, aged microglia are no longer capable of establishing effective immune responses and sustaining normal synaptic activity, directly contributing to age-associated cognitive decline and neurodegeneration. This review discusses how lifestyle and environmental factors drive microglia dysfunction at the molecular and functional level, also highlighting possible interventions to reverse aging-associated damage to the nervous and immune systems.


Assuntos
Envelhecimento/metabolismo , Encéfalo/metabolismo , Disfunção Cognitiva/metabolismo , Microglia/metabolismo , Plasticidade Neuronal , Estresse Oxidativo , Envelhecimento/patologia , Animais , Encéfalo/patologia , Senescência Celular , Disfunção Cognitiva/patologia , Humanos , Microglia/patologia , Neurogênese
20.
Neuropsychopharmacology ; 45(9): 1438-1447, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32492699

RESUMO

Social hierarchies are present in most mammalian species. In nature, hierarchies offer a tradeoff between reduction of in-group fighting between males, at the expense of an asymmetric sharing of resources. Early life experiences and stress are known to influence the rank an individual attains in adulthood, but the associated cellular and synaptic alterations are poorly understood. Using a maternal separation protocol, we show that care-deprived mice display a long-lasting submissive phenotype, increased social recognition, and enhanced explorative behavior. These alterations are consistent with an adaptation that favors exploration rather than confrontation within a group setting. At the neuronal level, these animals display dendritic atrophy and enhanced inhibitory synaptic inputs in medial prefrontal cortex (mPFC) neurons. To determine what could underlie this synaptic modification, we first assessed global gene expression changes via RNAseq, and next focused on a smaller subset of putatively altered synaptic receptors that could explain the changes in synaptic inhibition. Using different cohorts of maternally deprived mice, we validated a significant increase in the expression of Npy1r, a receptor known to play a role in maternal care, anxiety, foraging, and regulation of group behavior. Using electrophysiological recordings in adult mice while blocking NPY1R signaling, we determined that this receptor plays a key role in enhancing GABAergic currents in mice that experience maternal deprivation. Taken together, our work highlights the potential of regulating NPY1R in social anxiety disorders and the alterations induced in brain circuitry as a consequence of early life stress and adversity.


Assuntos
Hierarquia Social , Córtex Pré-Frontal , Estresse Psicológico , Animais , Masculino , Camundongos , Ansiedade , Comportamento Exploratório , Privação Materna
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