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1.
J Neurochem ; 162(6): 501-513, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-35797221

RESUMO

Glioblastoma is the most common and malignant type of primary brain tumor. Previous studies have shown that alterations in centrosome amplification and its components are frequently found in treatment-resistant tumors and may be associated with tumor progression. A centrosome protein essential for centrosome biogenesis is the centromere protein J (CENPJ), known to control the proliferation of neural progenitors and hepatocarcinoma cells, and also neuronal migration. However, it remains unknown the role of CENPJ in glioblastoma. Here we show that CENPJ is overexpressed in human glioblastoma cell lines in comparison to human astrocytes. Using bioinformatics analysis, we find that high Cenpj expression is associated with poor prognosis in glioma patients. Examining Cenpj loss of function in glioblastoma by siRNA transfection, we find impairments in cell proliferation and migration. Using a Cenpj mutant version with the deleted PN2-3 or TCP domain, we found that a conserved PN2-3 region is required for glioblastoma migration. Moreover, Cenpj downregulation modulates glioblastoma morphology resulting in microtubules stabilization and actin filaments depolymerization. Altogether, our findings indicate that CENPJ controls relevant aspects of glioblastoma progression and might be a target for therapeutic intervention and a biomarker for glioma malignancy.


Assuntos
Neoplasias Encefálicas , Glioblastoma , Glioma , Neoplasias Encefálicas/metabolismo , Linhagem Celular Tumoral , Movimento Celular , Proliferação de Células , Centrômero/metabolismo , Centrômero/patologia , Regulação Neoplásica da Expressão Gênica , Glioblastoma/metabolismo , Glioma/metabolismo , Humanos
2.
J Neurochem ; 150(2): 138-157, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31009074

RESUMO

Parkinson's disease (PD) is characterized by selective death of dopaminergic neurons in the substantia nigra, degeneration of the nigrostriatal pathway, increases in glutamatergic synapses in the striatum and aggregation of α-synuclein. Evidence suggests that oligomeric species of α-synuclein (αSO) are the genuine neurotoxins of PD. Although several studies have supported the direct neurotoxic effects of αSO on neurons, their effects on astrocytes have not been directly addressed. Astrocytes are essential to several steps of synapse formation and function, including secretion of synaptogenic factors, control of synaptic elimination and stabilization, secretion of neural/glial modulators, and modulation of extracellular ions, and neurotransmitter levels in the synaptic cleft. Here, we show that αSO induced the astrocyte reactivity and enhanced the synaptogenic capacity of human and murine astrocytes by increasing the levels of the known synaptogenic molecule transforming growth factor beta 1 (TGF-ß1). Moreover, intracerebroventricular injection of αSO in mice increased the number of astrocytes, the density of excitatory synapses, and the levels of TGF-ß1 in the striatum of injected animals. Inhibition of TGF-ß1 signaling impaired the effect of the astrocyte-conditioned medium on glutamatergic synapse formation in vitro and on striatal synapse formation in vivo, whereas addition of TGF-ß1 protected mesencephalic neurons against synapse loss triggered by αSO. Together, our data suggest that αSO have important effects on astrocytic functions and describe TGF-ß1 as a new endogenous astrocyte-derived molecule involved in the increase in striatal glutamatergic synaptic density present in early stages of PD. OPEN SCIENCE BADGES: This article has received a badge for *Open Materials* because it provided all relevant information to reproduce the study in the manuscript. The complete Open Science Disclosure form for this article can be found at the end of the article. More information about the Open Practices badges can be found at https://cos.io/our-services/open-science-badges/. Cover Image for this issue: doi: 10.1111/jnc.14514.


Assuntos
Astrócitos/metabolismo , Transtornos Parkinsonianos/metabolismo , Sinapses/metabolismo , Fator de Crescimento Transformador beta1/metabolismo , alfa-Sinucleína/metabolismo , Animais , Modelos Animais de Doenças , Humanos , Camundongos , Neurogênese/fisiologia , Transdução de Sinais/fisiologia
3.
Purinergic Signal ; 15(4): 439-450, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31478180

RESUMO

The guanine-based purines (GBPs) have essential extracellular functions such as modulation of glutamatergic transmission and trophic effects on neurons and astrocytes. We previously showed that GBPs, such as guanosine-5'-monophosphate (GMP) or guanosine (GUO), promote the reorganization of extracellular matrix proteins in astrocytes, and increase the number of neurons in a neuron-astrocyte co-culture protocol. To delineate the molecular basis underlying these effects, we isolated cerebellar neurons in culture and treated them with a conditioned medium derived from astrocytes previously exposed to GUO or GMP (GBPs-ACM) or, directly, with GUO or GMP. Agreeing with the previous studies, there was an increase in the number of ß-tubulin III-positive neurons in both conditions, compared with controls. Interestingly, the increase in the number of neurons in the neuronal cultures treated directly with GUO or GMP was more prominent, suggesting a direct interaction of GBPs on cerebellar neurons. To investigate this issue, we assessed the role of adenosine and glutamate receptors and related intracellular signaling pathways after GUO or GMP treatment. We found an involvement of A2A adenosine receptors, ionotropic glutamate N-methyl-D-aspartate (NMDA), and non-NMDA receptors in the increased number of cerebellar neurons. The signaling pathways extracellular-regulated kinase (ERK), calcium-calmodulin-dependent kinase-II (CaMKII), protein kinase C (PKC), phosphatidilinositol-3'-kinase (PI3-K), and protein kinase A (PKA) are also potentially involved with GMP and GUO effect. Such results suggest that GMP and GUO, and molecules released in GBPs-ACM promote the survival or maturation of primary cerebellar neurons or both via interaction with adenosine and glutamate receptors.


Assuntos
Adenosina/metabolismo , Guanosina/metabolismo , Neurônios/metabolismo , Receptores de Glutamato/metabolismo , Animais , Astrócitos/metabolismo , Sistema Nervoso Central/metabolismo , Ácido Glutâmico/metabolismo , Guanosina Monofosfato/metabolismo , Receptores Purinérgicos P1/metabolismo
4.
Bioorg Chem ; 83: 87-97, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30343205

RESUMO

A new series of 1,4-disubstituted-1,2,3-triazole derivatives were synthesized through the copper-catalyzed azide-alkyne 1,3-dipolar cycloaddition (Click chemistry) and their inhibitory activities were evaluated against different human glioblastoma (GBM) cell lines, including highly drug-resistant human cell lines GBM02, GBM95. The most effective compounds were 9d, containing the methylenoxy moiety linked to triazole and the tosyl-hydrazone group, and the symmetrical bis-triazole 10a, also containing methylenoxy moiety linked to triazole. Single crystal X-ray diffraction analysis was employed for structural elucidation of compound 9d. In silico analyses of physicochemical, pharmacokinetic, and toxicological properties suggest that compounds 8a, 8b, 8c, 9d, and 10a are potential candidates for central nervous system-acting drugs.


Assuntos
Antineoplásicos/farmacologia , Desenho de Fármacos , Glioblastoma/tratamento farmacológico , Triazóis/farmacologia , Animais , Antineoplásicos/síntese química , Antineoplásicos/química , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Glioblastoma/patologia , Humanos , Estrutura Molecular , Ratos , Relação Estrutura-Atividade , Triazóis/síntese química , Triazóis/química , Células Tumorais Cultivadas
5.
An Acad Bras Cienc ; 91(4): e20191031, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31800712

RESUMO

Diosmin is a flavone glycoside clinically used as the main component of Daflon for the treatment of venous diseases. Several studies demonstrated that this natural compound can induce apoptosis in different tumors. However, isolated diosmin has not been studied regarding its effects on glioblastoma so far. Since glioblastoma is a highly lethal and fast-growing brain tumor, new therapeutic strategies are urgently needed. Herein, we evaluated the role of this flavonoid against glioblastoma cells using in vitro assays. Diosmin significantly reduced the viability of GBM95, GBM02, and U87MG glioblastoma cells, but not of healthy human astrocytes, as verified by MTT assay. Vimentin immunostaining showed that diosmin induced morphological changes in GBM95 and GBM02 cells, making them smaller and more polygonal. Diosmin did not inhibit GBM95 and GBM02 cell proliferation, but it caused DNA fragmentation, as verified by the TUNEL assay, and increased cleaved caspase-3 expression in these cells. In summary, diosmin is able to induce caspase-dependent apoptosis specifically in tumor cells and, therefore, could be considered a promising therapeutic compound against glioblastoma.


Assuntos
Apoptose/efeitos dos fármacos , Diosmina/farmacologia , Neoplasias Encefálicas/patologia , Linhagem Celular Tumoral , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Glioblastoma/patologia , Humanos , Transdução de Sinais/efeitos dos fármacos
6.
Biochem Biophys Res Commun ; 505(1): 295-301, 2018 10 20.
Artigo em Inglês | MEDLINE | ID: mdl-30249394

RESUMO

The dopamine metabolite 3,4-dihydroxyphenylacetaldehyde (DOPAL) is believed to play a central role in Parkinson's disease neurodegeneration by stabilizing potentially toxic oligomers of the presynaptic protein α-Synuclein (aSyn). Besides the formation of covalent DOPAL-Lys adducts, DOPAL promotes the oxidation of Met residues of aSyn, which is also a common oxidative post-translational modification found in the protein in vivo. Herein we set out to address the role of Met residues on the oligomerization and neurotoxic properties of DOPAL-modified aSyn. Our data indicate that DOPAL promotes the formation of two distinct types of aSyn oligomers: large and small (dimer and trimers) oligomers, which seem to be generated by independent mechanisms and cannot be interconverted by using denaturing agents. Interestingly, H2O2-treated aSyn monomer, which exhibits all-four Met residues oxidized to Met-sulfoxide, exhibited a reduced ability to form large oligomers upon treatment with DOPAL, with no effect on the population of small oligomers. In this context, triple Met-Val mutant M5V/M116V/M127V exhibited an increased population of large aSyn-DOPAL oligomers in comparison with the wild-type protein. Interestingly, the stabilization of large rather than small oligomers seems to be associated with an enhanced toxicity of DOPAL-aSyn adducts. Collectively, these findings indicate that Met residues may play an important role in modulating both the oligomerization and the neurotoxic properties of DOPAL-derived aSyn species.


Assuntos
Ácido 3,4-Di-Hidroxifenilacético/farmacologia , Metionina/química , Neurônios/efeitos dos fármacos , Multimerização Proteica/efeitos dos fármacos , alfa-Sinucleína/toxicidade , Ácido 3,4-Di-Hidroxifenilacético/análogos & derivados , Animais , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Humanos , Peróxido de Hidrogênio/farmacologia , Metionina/genética , Camundongos , Mutação , Neurônios/citologia , Oxidantes/farmacologia , Oxirredução/efeitos dos fármacos , Processamento de Proteína Pós-Traducional/efeitos dos fármacos , alfa-Sinucleína/química , alfa-Sinucleína/genética
7.
Anticancer Drugs ; 29(6): 520-529, 2018 07.
Artigo em Inglês | MEDLINE | ID: mdl-29561308

RESUMO

Glioblastoma multiform (GBM) is the most common and devastating type of primary brain tumor, being considered the deadliest of human cancers. In this context, extensive efforts have been undertaken to develop new drugs that exhibit both antiproliferation and antimetastasis effects on GBM. 1,4-Naphthoquinone (1,4-NQ) scaffold has been found in compounds able to inhibit important biological targets associated with cancer, which includes DNA topoisomerase, Hsp90 and monoamine oxidase. Among potential antineoplastic 1,4-NQs is the plant-derived lapachol (2-hydroxy-3-prenyl-1,4-naphthoquinone) that was found to be active against the Walker-256 carcinoma and Yoshida sarcoma. In the present study, we examined the effect of polyamine (PA)-conjugated derivatives of lapachol, nor-lapachol and lawsone on the growth and invasion of the human GBM cells. The conjugation with PA (a spermidine analog) resulted in dose-dependent and time-dependent increase of cytotoxicity of the 1,4-NQs. In addition, in-vitro inhibition of GBM cell invasion by lapachol was increased upon PA conjugation. Previous biochemical experiments indicated that these PA-1,4-NQs are capable of inhibiting DNA human topoisomerase II-α (topo2α), a major enzyme involved in maintaining DNA topology. Herein, we applied molecular docking to investigate the binding of PA-1,4-NQs to the ATPase site of topo2α. The most active molecules preferentially bind at the ATP-binding site of topo2α, which is energetically favored by the conjugation with PA. Taken together, these findings suggested that the PA-1,4-NQ conjugates might represent potential molecules in the development of new drugs in chemotherapy for malignant brain tumors.


Assuntos
Neoplasias Encefálicas/tratamento farmacológico , Glioblastoma/tratamento farmacológico , Naftoquinonas/farmacologia , Poliaminas/farmacologia , Trifosfato de Adenosina/metabolismo , Animais , Antineoplásicos/síntese química , Antineoplásicos/química , Antineoplásicos/farmacologia , Antineoplásicos Fitogênicos/síntese química , Antineoplásicos Fitogênicos/química , Antineoplásicos Fitogênicos/farmacologia , Astrócitos/efeitos dos fármacos , Astrócitos/patologia , Sítios de Ligação , Neoplasias Encefálicas/metabolismo , Neoplasias Encefálicas/patologia , Linhagem Celular Tumoral , Córtex Cerebral/citologia , Córtex Cerebral/efeitos dos fármacos , DNA Topoisomerases Tipo II/metabolismo , Glioblastoma/metabolismo , Glioblastoma/patologia , Humanos , Camundongos , Naftoquinonas/síntese química , Naftoquinonas/química , Poliaminas/síntese química , Poliaminas/química , Cultura Primária de Células
8.
J Biol Chem ; 290(33): 20527-40, 2015 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-26149686

RESUMO

Cerebral dopamine neurotrophic factor (CDNF) is a promising therapeutic agent for Parkinson disease. As such, there has been great interest in studying its mode of action, which remains unknown. The three-dimensional crystal structure of the N terminus (residues 9-107) of CDNF has been determined, but there have been no published structural studies on the full-length protein due to proteolysis of its C-terminal domain, which is considered intrinsically disordered. An improved purification protocol enabled us to obtain active full-length CDNF and to determine its three-dimensional structure in solution. CDNF contains two well folded domains (residues 10-100 and 111-157) that are linked by a loop of intermediate flexibility. We identified two surface patches on the N-terminal domain that were characterized by increased conformational dynamics that should allow them to embrace active sites. One of these patches is formed by residues Ser-33, Leu-34, Ala-66, Lys-68, Ile-69, Leu-70, Ser-71, and Glu-72. The other includes a flexibly disordered N-terminal tail (residues 1-9), followed by the N-terminal portion of α-helix 1 (residues Cys-11, Glu-12, Val-13, Lys-15, and Glu-16) and residue Glu-88. The surface of the C-terminal domain contains two conserved active sites, which have previously been identified in mesencephalic astrocyte-derived neurotrophic factor, a CDNF paralog, which corresponds to its intracellular mode of action. We also showed that CDNF was able to protect dopaminergic neurons against injury caused by α-synuclein oligomers. This advises its use against physiological damages caused by α-synuclein oligomers, as observed in Parkinson disease and several other neurodegenerative diseases.


Assuntos
Biopolímeros/metabolismo , Fatores de Crescimento Neural/química , Fatores de Crescimento Neural/fisiologia , Fármacos Neuroprotetores , alfa-Sinucleína/metabolismo , Animais , Linhagem Celular , Cristalografia por Raios X , Humanos , Camundongos , Ressonância Magnética Nuclear Biomolecular , Conformação Proteica , Relação Estrutura-Atividade
9.
Glia ; 62(12): 1917-31, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25042347

RESUMO

The balance between excitatory and inhibitory synaptic inputs is critical for the control of brain function. Astrocytes play important role in the development and maintenance of neuronal circuitry. Whereas astrocytes-derived molecules involved in excitatory synapses are recognized, molecules and molecular mechanisms underlying astrocyte-induced inhibitory synapses remain unknown. Here, we identified transforming growth factor beta 1 (TGF-ß1), derived from human and murine astrocytes, as regulator of inhibitory synapse in vitro and in vivo. Conditioned media derived from human and murine astrocytes induce inhibitory synapse formation in cerebral cortex neurons, an event inhibited by pharmacologic and genetic manipulation of the TGF-ß pathway. TGF-ß1-induction of inhibitory synapse depends on glutamatergic activity and activation of CaM kinase II, which thus induces localization and cluster formation of the synaptic adhesion protein, Neuroligin 2, in inhibitory postsynaptic terminals. Additionally, intraventricular injection of TGF-ß1 enhanced inhibitory synapse number in the cerebral cortex. Our results identify TGF-ß1/CaMKII pathway as a novel molecular mechanism underlying astrocyte control of inhibitory synapse formation. We propose here that the balance between excitatory and inhibitory inputs might be provided by astrocyte signals, at least partly achieved via TGF-ß1 downstream pathways. Our work contributes to the understanding of the GABAergic synapse formation and may be of relevance to further the current knowledge on the mechanisms underlying the development of various neurological disorders, which commonly involve impairment of inhibitory synapse transmission.


Assuntos
Astrócitos/química , Proteína Quinase Tipo 2 Dependente de Cálcio-Calmodulina/metabolismo , Neurônios/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos , Fator de Crescimento Transformador beta/farmacologia , Animais , Animais Recém-Nascidos , Astrócitos/metabolismo , Células Cultivadas , Córtex Cerebral/citologia , Meios de Cultivo Condicionados/farmacologia , Embrião de Mamíferos , Inibidores Enzimáticos/farmacologia , Agonistas de Aminoácidos Excitatórios/farmacologia , Ácido Glutâmico/metabolismo , Humanos , Injeções Intraventriculares , Masculino , Camundongos , N-Metilaspartato/farmacologia , Inibição Neural/efeitos dos fármacos , Inibição Neural/fisiologia , Neurônios/ultraestrutura , Receptores de GABA-A/metabolismo , Sinapses/metabolismo , Sinapses/ultraestrutura , Proteínas Vesiculares de Transporte de Aminoácidos Inibidores/metabolismo
10.
BMC Cancer ; 14: 923, 2014 Dec 08.
Artigo em Inglês | MEDLINE | ID: mdl-25482099

RESUMO

BACKGROUND: Glioblastoma (GBM) is the most common primary brain tumor and the most aggressive glial tumor. This tumor is highly heterogeneous, angiogenic, and insensitive to radio- and chemotherapy. Here we have investigated the progression of GBM produced by the injection of human GBM cells into the brain parenchyma of immunocompetent mice. METHODS: Xenotransplanted animals were submitted to magnetic resonance imaging (MRI) and histopathological analyses. RESULTS: Our data show that two weeks after injection, the produced tumor presents histopathological characteristics recommended by World Health Organization for the diagnosis of GBM in humans. The tumor was able to produce reactive gliosis in the adjacent parenchyma, angiogenesis, an intense recruitment of macrophage and microglial cells, and presence of necrosis regions. Besides, MRI showed that tumor mass had enhanced contrast, suggesting a blood-brain barrier disruption. CONCLUSIONS: This study demonstrated that the xenografted tumor in mouse brain parenchyma develops in a very similar manner to those found in patients affected by GBM and can be used to better understand the biology of GBM as well as testing potential therapies.


Assuntos
Neoplasias Encefálicas/patologia , Encéfalo/patologia , Modelos Animais de Doenças , Glioblastoma/patologia , Microambiente Tumoral , Animais , Encéfalo/irrigação sanguínea , Neoplasias Encefálicas/complicações , Glioblastoma/complicações , Glioblastoma/fisiopatologia , Gliose/etiologia , Humanos , Imunocompetência , Ativação de Macrófagos , Imageamento por Ressonância Magnética , Masculino , Camundongos , Microglia/fisiologia , Necrose/etiologia , Neovascularização Patológica/etiologia , Transplante Heterólogo
11.
J Biol Chem ; 287(49): 41432-45, 2012 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-23055518

RESUMO

Assembly of synapses requires proper coordination between pre- and postsynaptic elements. Identification of cellular and molecular events in synapse formation and maintenance is a key step to understand human perception, learning, memory, and cognition. A key role for astrocytes in synapse formation and function has been proposed. Here, we show that transforming growth factor ß (TGF-ß) signaling is a novel synaptogenic pathway for cortical neurons induced by murine and human astrocytes. By combining gain and loss of function approaches, we show that TGF-ß1 induces the formation of functional synapses in mice. Further, TGF-ß1-induced synaptogenesis involves neuronal activity and secretion of the co-agonist of the NMDA receptor, D-serine. Manipulation of D-serine signaling, by either genetic or pharmacological inhibition, prevented the TGF-ß1 synaptogenic effect. Our data show a novel molecular mechanism that might impact synaptic function and emphasize the evolutionary aspect of the synaptogenic property of astrocytes, thus shedding light on new potential therapeutic targets for synaptic deficit diseases.


Assuntos
Astrócitos/citologia , Córtex Cerebral/metabolismo , Neurônios/metabolismo , Serina/química , Sinapses/metabolismo , Fator de Crescimento Transformador beta/metabolismo , Animais , Células Cultivadas , Cognição , Meios de Cultivo Condicionados/farmacologia , Eletrofisiologia , Humanos , Camundongos , Modelos Biológicos , Técnicas de Patch-Clamp , Transdução de Sinais , Transfecção
12.
Biochim Biophys Acta ; 1826(2): 338-49, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-22677165

RESUMO

Glioblastoma (GBM) is one of the most aggressive human cancers. Despite current advances in multimodality therapies, such as surgery, radiotherapy and chemotherapy, the outcome for patients with high grade glioma remains fatal. The knowledge of how glioma cells develop and depend on the tumor environment might open opportunities for new therapies. There is now a growing awareness that the main limitations in understanding and successfully treating GBM might be bypassed by the identification of a distinct cell type that has defining properties of somatic stem cells, as well as cancer-initiating capacity - brain tumor stem cells, which could represent a therapeutic target. In addition, experimental studies have demonstrated that the combination of antiangiogenic therapy, based on the disruption of tumor blood vessels, with conventional chemotherapy generates encouraging results. Emerging reports have also shown that microglial cells can be used as therapeutic vectors to transport genes and/or substances to the tumor site, which opens up new perspectives for the development of GBM therapies targeting microglial cells. Finally, recent studies have shown that natural toxins can be conjugated to drugs that bind to overexpressed receptors in cancer cells, generating targeted-toxins to selectively kill cancer cells. These targeted-toxins are highly effective against radiation- and chemotherapy-resistant cancer cells, making them good candidates for clinical trials in GBM patients. In this review, we discuss recent studies that reveal new possibilities of GBM treatment taking into account cancer stem cells, angiogenesis, microglial cells and drug delivery in the development of new targeted-therapies.


Assuntos
Neoplasias Encefálicas/tratamento farmacológico , Glioblastoma/tratamento farmacológico , Sistemas de Liberação de Medicamentos , Proteínas Hedgehog/fisiologia , Humanos , Microglia/fisiologia , Células-Tronco Neoplásicas/efeitos dos fármacos , Interferência de RNA , Transdução de Sinais , Fator A de Crescimento do Endotélio Vascular/antagonistas & inibidores
13.
Viruses ; 15(2)2023 02 13.
Artigo em Inglês | MEDLINE | ID: mdl-36851730

RESUMO

The Salmonella enterica bacteriophage P22 is one of the most promising models for the development of virus-like particle (VLP) nanocages. It possesses an icosahedral T = 7 capsid, assembled by the combination of two structural proteins: the coat protein (gp5) and the scaffold protein (gp8). The P22 capsid has the remarkable capability of undergoing structural transition into three morphologies with differing diameters and wall-pore sizes. These varied morphologies can be explored for the design of nanoplatforms, such as for the development of cargo internalization strategies. The capsid proteic nature allows for the extensive modification of its structure, enabling the addition of non-native structures to alter the VLP properties or confer them to diverse ends. Various molecules were added to the P22 VLP through genetic, chemical, and other means to both the capsid and the scaffold protein, permitting the encapsulation or the presentation of cargo. This allows the particle to be exploited for numerous purposes-for example, as a nanocarrier, nanoreactor, and vaccine model, among other applications. Therefore, the present review intends to give an overview of the literature on this amazing particle.


Assuntos
Bacteriófago P22 , Viroides , Capsídeo , Proteínas do Capsídeo/genética , Núcleo Celular , Nanotecnologia
14.
Cancers (Basel) ; 15(19)2023 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-37835434

RESUMO

Glioblastoma (GB) is the most aggressive primary malignant brain tumor and is associated with short survival. O-GlcNAcylation is an intracellular glycosylation that regulates protein function, enzymatic activity, protein stability, and subcellular localization. Aberrant O-GlcNAcylation is related to the tumorigenesis of different tumors, and mounting evidence supports O-GlcNAc transferase (OGT) as a potential therapeutic target. Here, we used two human GB cell lines alongside primary human astrocytes as a non-tumoral control to investigate the role of O-GlcNAcylation in cell proliferation, cell cycle, autophagy, and cell death. We observed that hyper O-GlcNAcylation promoted increased cellular proliferation, independent of alterations in the cell cycle, through the activation of autophagy. On the other hand, hypo O-GlcNAcylation inhibited autophagy, promoted cell death by apoptosis, and reduced cell proliferation. In addition, the decrease in O-GlcNAcylation sensitized GB cells to the chemotherapeutic temozolomide (TMZ) without affecting human astrocytes. Combined, these results indicated a role for O-GlcNAcylation in governing cell proliferation, autophagy, cell death, and TMZ response, thereby indicating possible therapeutic implications for treating GB. These findings pave the way for further research and the development of novel treatment approaches which may contribute to improved outcomes and increased survival rates for patients facing this challenging disease.

15.
Cell Rep ; 42(3): 112189, 2023 03 28.
Artigo em Inglês | MEDLINE | ID: mdl-36857178

RESUMO

Cognitive dysfunction is often reported in patients with post-coronavirus disease 2019 (COVID-19) syndrome, but its underlying mechanisms are not completely understood. Evidence suggests that severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Spike protein or its fragments are released from cells during infection, reaching different tissues, including the CNS, irrespective of the presence of the viral RNA. Here, we demonstrate that brain infusion of Spike protein in mice has a late impact on cognitive function, recapitulating post-COVID-19 syndrome. We also show that neuroinflammation and hippocampal microgliosis mediate Spike-induced memory dysfunction via complement-dependent engulfment of synapses. Genetic or pharmacological blockage of Toll-like receptor 4 (TLR4) signaling protects animals against synapse elimination and memory dysfunction induced by Spike brain infusion. Accordingly, in a cohort of 86 patients who recovered from mild COVID-19, the genotype GG TLR4-2604G>A (rs10759931) is associated with poor cognitive outcome. These results identify TLR4 as a key target to investigate the long-term cognitive dysfunction after COVID-19 infection in humans and rodents.


Assuntos
COVID-19 , Disfunção Cognitiva , Humanos , Animais , Camundongos , COVID-19/complicações , Glicoproteína da Espícula de Coronavírus/genética , SARS-CoV-2/metabolismo , Receptor 4 Toll-Like , Síndrome de COVID-19 Pós-Aguda
16.
FEBS Lett ; 596(3): 309-322, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-34928512

RESUMO

The misfolding and aggregation of the protein α-synuclein (aSyn) into potentially neurotoxic oligomers is believed to play a pivotal role in the neuropathogenesis of Parkinson's disease (PD). Herein, we explore how apomorphine (Apo), a nonselective dopamine D1 and D2 receptor agonist utilized in the therapy for PD, affects the aggregation and toxicity of aSyn in vitro. Our data indicated that Apo inhibits aSyn fibrillation leading to the formation of large oligomeric species (Apo-aSyn-O), which exhibit remarkable toxicity in mesencephalic dopaminergic neurons in primary cultures. Interestingly, purified Apo-aSyn-O, even at very low concentrations, seems to be capable of converting unmodified aSyn monomer into neurotoxic species. Collectively, our findings warn for a possible dangerous effect of Apo on aSyn misfolding/aggregation pathway.


Assuntos
alfa-Sinucleína
17.
J Mol Med (Berl) ; 100(10): 1405-1425, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-36056255

RESUMO

Cellular prion protein (PrPC) is a highly conserved glycoprotein, present both anchored in the cell membrane and soluble in the extracellular medium. It has a diversity of ligands and is variably expressed in numerous tissues and cell subtypes, most notably in the central nervous system (CNS). Its importance has been brought to light over the years both under physiological conditions, such as embryogenesis and immune system homeostasis, and in pathologies, such as cancer and neurodegenerative diseases. During development, PrPC plays an important role in CNS, participating in axonal growth and guidance and differentiation of glial cells, but also in other organs such as the heart, lung, and digestive system. In diseases, PrPC has been related to several types of tumors, modulating cancer stem cells, enhancing malignant properties, and inducing drug resistance. Also, in non-neoplastic diseases, such as Alzheimer's and Parkinson's diseases, PrPC seems to alter the dynamics of neurotoxic aggregate formation and, consequently, the progression of the disease. In this review, we explore in detail the multiple functions of this protein, which proved to be relevant for understanding the dynamics of organism homeostasis, as well as a promising target in the treatment of both neoplastic and degenerative diseases.


Assuntos
Neoplasias , Doenças Neurodegenerativas , Proteínas PrPC , Sistema Nervoso Central/metabolismo , Humanos , Células-Tronco Neoplásicas/metabolismo , Proteínas PrPC/genética , Proteínas PrPC/metabolismo
18.
Neurosci Lett ; 771: 136466, 2022 02 06.
Artigo em Inglês | MEDLINE | ID: mdl-35051434

RESUMO

Physical exercise is considered an adjuvant treatment to Parkinson's disease (PD) patients, possibly reducing inflammatory responses in the brain. Studies have stated that physical exercise protects dopaminergic neurons in PD models produced by neurotoxins. However, few studies focused on immunohistochemically reacted astrocytes and morphometric analyses of these cells in a PD mouse model submitted to physical exercise. We investigated the effects of treadmill training on striatal astrocytes of a PD mouse model combining immunohistochemistry and western-blotting for glial fibrillary acidic protein (GFAP) with morphometric analyses. Male Swiss mice were divided into 4 groups: sedentary control (SEDCONT), exercise control (EXERCONT), sedentary Parkinson (SEDPD), and exercise Parkinson (EXERPD). Stereotaxic bilateral injections of 6-hydroxydopamine into the striatum were adopted for PD groups. Striatal astrocytes showed increased GFAP in EXERPD, and we observed a higher level of GFAP in EXERPD than SEDPD. The number of primary and secondary processes was similar in striatal astrocytes of control groups and EXERPD. The astrocyte primary processes of SEDPD were larger than those of EXERPD, EXERCONT and SEDCONT. Cell body diameters and areas showed no difference between groups. We concluded that physical exercise influences striatal astrocytes in exercised parkinsonian mice.


Assuntos
Astrócitos/metabolismo , Corpo Estriado/fisiopatologia , Doença de Parkinson/terapia , Condicionamento Físico Animal/métodos , Animais , Corpo Estriado/citologia , Proteína Glial Fibrilar Ácida/genética , Proteína Glial Fibrilar Ácida/metabolismo , Masculino , Camundongos , Corrida
19.
IET Nanobiotechnol ; 15(6): 558-564, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34694742

RESUMO

Glioblastoma is the most life-threatening tumour of the central nervous system. Temozolomide (TMZ) is the first-choice oral drug for the treatment of glioblastoma, although it shows low efficacy. Silver nanoparticles (AgNPs) have been shown to exhibit biocidal activity in a variety of microorganisms, including some pathogenic microorganisms. Herein, the antiproliferative effect of AgCl-NPs on glioblastoma cell lines (GBM02 and GBM11) and on astrocytes was evaluated through automated quantitative image-based analysis (HCA) of the cells. The cells were treated with 0.1-5.0 µg/ml AgCl-NPs or with 9.7-48.5 µg/ml TMZ. Cells that received combined treatment were also analysed. At a maximum tested concentration of AgCl-NPs, GBM02 and GBM11, the growth decreased by 93% and 40%, respectively, following 72 h of treatment. TMZ treatment decreased the proliferation of GBM02 and GBM11 cells by 58% and 34%, respectively. Combinations of AgCl-NPs and TMZ showed intermediate antiproliferative effects; the lowest concentrations caused an inhibition similar to that obtained with TMZ, and the highest concentrations caused inhibition similar to that obtained with AgCl-NPs alone. No significant changes in astrocyte proliferation were observed. The authors' findings showed that HCA is a fast and reliable approach that can be used to evaluate the antiproliferative effect of the nanoparticles at the single-cell level and that AgCl-NPs are promising agents for glioblastoma treatment.


Assuntos
Glioblastoma , Nanopartículas Metálicas , Linhagem Celular Tumoral , Cloretos , Glioblastoma/tratamento farmacológico , Humanos , Prata/farmacologia , Compostos de Prata
20.
Neurosci Lett ; 760: 136089, 2021 08 24.
Artigo em Inglês | MEDLINE | ID: mdl-34182056

RESUMO

Previous research advocates that exercise is a non-pharmacological therapy for Parkinson's disease (PD). However, few studies have investigated the effects of exercise on central nervous system structures other than the nigrostriatal pathway by using PD animal models. This study investigated the effects of exercise on tyrosine hydroxylase (TH)- and cerebral dopamine neurotrophic factor (CDNF)-containing spinal-cord neurons. Male Swiss mice were divided into 4 groups: sedentary control (SEDCONT), exercise control (EXERCONT), sedentary Parkinson (SEDPD), and exercise Parkinson (EXERPD). The PD groups were submitted to a surgical procedure for stereotaxic bilateral injection of 6-hydroxydopamine into the striatum. TH- and CDNF-containing spinal-cord neurons were evaluated in all groups, using immunohistochemistry and western-blotting. TH content in the ventral horn differed notably between the SEDPD and EXERPD groups. CDNF content was highest in the EXERPD group. SEDPD and EXERPD groups differed the most, as shown by immunohistochemistry and western-blotting. The EXERPD group showed the most intense labeling in immunohistochemistry compared to the SEDCONT and EXERCONT groups. Therefore, we showed here that exercise increased the content of both TH and CDNF in the spinal-cord neurons of a bilateral PD mouse model. We may assume that the spinal cord is affected in a PD model, and therefore this central nervous system region deserves more attention from researchers dealing with PD.


Assuntos
Neurônios Motores/metabolismo , Fatores de Crescimento Neural/metabolismo , Transtornos Parkinsonianos/reabilitação , Tirosina 3-Mono-Oxigenase/metabolismo , Animais , Corpo Estriado/metabolismo , Modelos Animais de Doenças , Humanos , Masculino , Camundongos , Fatores de Crescimento Neural/análise , Oxidopamina/metabolismo , Transtornos Parkinsonianos/patologia , Medula Espinal/citologia , Medula Espinal/metabolismo , Medula Espinal/patologia , Tirosina 3-Mono-Oxigenase/análise
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