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1.
Prog Neurobiol ; 199: 101953, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33188884

RESUMO

Protective effects of the telomerase protein TERT have been shown in neurons and brain. We previously demonstrated that TERT protein can accumulate in mitochondria of Alzheimer's disease (AD) brains and protect from pathological tau in primary mouse neurons. This prompted us to employ telomerase activators in order to boost telomerase expression in a mouse model of Parkinson's disease (PD) overexpressing human wild type α-synuclein. Our aim was to test whether increased Tert expression levels were able to ameliorate PD symptoms and to activate protein degradation. We found increased Tert expression in brain for both activators which correlated with a substantial improvement of motor functions such as gait and motor coordination while telomere length in the analysed region was not changed. Interestingly, only one activator (TA-65) resulted in a decrease of reactive oxygen species from brain mitochondria. Importantly, we demonstrate that total, phosphorylated and aggregated α-synuclein were significantly decreased in the hippocampus and neocortex of activator-treated mice corresponding to enhanced markers of autophagy suggesting an improved degradation of toxic alpha-synuclein. We conclude that increased Tert expression caused by telomerase activators is associated with decreased α-synuclein protein levels either by activating autophagy or by preventing or delaying impairment of degradation mechanisms during disease progression. This encouraging preclinical data could be translated into novel therapeutic options for neurodegenerative disorders such as PD.


Assuntos
Doença de Parkinson , alfa-Sinucleína/metabolismo , Animais , Autofagia , Modelos Animais de Doenças , Camundongos , Camundongos Transgênicos , Doença de Parkinson/genética , Telomerase/genética , alfa-Sinucleína/genética
2.
Dev Biol ; 470: 74-83, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33159936

RESUMO

We previously identified the protein Lbh as necessary for cranial neural crest (CNC) cell migration in Xenopus through the use of morpholinos. However, Lbh is a maternally deposited protein and morpholinos achieve knockdowns through prevention of translation. In order to investigate the role of Lbh in earlier embryonic events, we employed the new technique "Trim-Away" to degrade this maternally deposited protein. Trim-Away utilizes the E3 ubiquitin ligase trim21 to degrade proteins targeted with an antibody and was developed in mammalian systems. Our results show that Xenopus is amenable to the Trim-Away technique. We also show that early knockdown of Lbh in Xenopus results in defects in gastrulation that present with a decrease in fibronectin matrix assembly, an increased in mesodermal cell migration and decrease in endodermal cell cohesion. We further show that the technique is also effective on a second abundant maternal protein PACSIN2. We discuss potential advantages and limit of the technique in Xenopus embryos as well as the mechanism of gastrulation inhibition.


Assuntos
Gastrulação , Proteínas de Xenopus/fisiologia , Xenopus laevis/embriologia , Proteínas Adaptadoras de Transdução de Sinal/imunologia , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Animais , Anticorpos Monoclonais/imunologia , Movimento Celular , Ectoderma/citologia , Ectoderma/embriologia , Ectoderma/patologia , Indução Embrionária , Endoderma/citologia , Endoderma/embriologia , Endoderma/fisiologia , Fibronectinas/metabolismo , Mesoderma/citologia , Mesoderma/embriologia , Mesoderma/fisiologia , Morfolinos , Crista Neural/citologia , Crista Neural/embriologia , Proteólise , Ribonucleoproteínas/genética , Ribonucleoproteínas/metabolismo , Proteínas de Xenopus/genética , Proteínas de Xenopus/imunologia , Proteínas de Xenopus/metabolismo
3.
Mol Biol Cell ; 31(3): 167-183, 2020 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-31851597

RESUMO

Protein glycosylation plays essential roles in protein structure, stability, and activity such as cell adhesion. The cadherin superfamily of adhesion molecules carry O-linked mannose glycans at conserved sites and it was recently demonstrated that the transmembrane and tetratricopeptide repeat-containing proteins 1-4 (TMTC1-4) gene products contribute to the addition of these O-linked mannoses. Here, biochemical, cell biological, and organismal analysis was used to determine that TMTC3 supports the O-mannosylation of E-cadherin, cellular adhesion, and embryonic gastrulation. Using genetically engineered cells lacking all four TMTC genes, overexpression of TMTC3 rescued O-linked glycosylation of E-cadherin and cell adherence. The knockdown of the Tmtcs in Xenopus laevis embryos caused a delay in gastrulation that was rescued by the addition of human TMTC3. Mutations in TMTC3 have been linked to neuronal cell migration diseases including Cobblestone lissencephaly. Analysis of TMTC3 mutations associated with Cobblestone lissencephaly found that three of the variants exhibit reduced stability and missence mutations were unable to complement TMTC3 rescue of gastrulation in Xenopus embryo development. Our study demonstrates that TMTC3 regulates O-linked glycosylation and cadherin-mediated adherence, providing insight into its effect on cellular adherence and migration, as well the basis of TMTC3-associated Cobblestone lissencephaly.


Assuntos
Caderinas/metabolismo , Proteínas de Transporte/metabolismo , Retículo Endoplasmático/metabolismo , Proteínas de Membrana/metabolismo , Animais , Células COS , Proteínas de Transporte/genética , Adesão Celular/fisiologia , Moléculas de Adesão Celular/metabolismo , Chlorocebus aethiops , Gastrulação/fisiologia , Glicosilação , Células HEK293 , Humanos , Manose/metabolismo , Proteínas de Membrana/genética , Mutação , Neurônios/citologia , Neurônios/metabolismo , Xenopus laevis
4.
Colloids Surf B Biointerfaces ; 78(2): 208-16, 2010 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-20356719

RESUMO

Biofilms present operational problems to a variety of industrial areas including but not limited to, medicine, water treatment, sensor sensitivity and shipping. Bacterial adhesion resides as a tiny monolayer and builds-up over time with the production of protective slimes known as extracellular polymeric substances (EPS) forming the 'biofilm'. Infection, inefficiency and diminution of quality are caused by biofilms, which have the potential to be prohibitively expensive to repair. The value of an effective coating that prevents the adhesion of bacteria and subsequent fouling is paramount in preserving sensitivity and longevity of a subjected operational substrate. Polymer and sol-gel (SG) based coatings tender a matrix for the introduction of biocides and antimicrobial agents that offer this prevention. They present a relatively cheap and optically clear platform that can then be doped with the antimicrobial agent. This proves useful in transferring across a range of industries that may require a transparent function to the coating. Nanoparticles offer a means of new line research in combating biofouling and biocorrosion with interest stemming from silver metal nanoparticles (MNPs) that already offer antimicrobial property. The aim of this work is to investigate period four metal nanoparticles for any antimicrobial potential they offer, in the prevention of fouling in the early stages. The research presented herein uses a range of period four MNPs synthesised through an adapted polyol reduction, which have then been doped into SG coatings and tested for their efficacy in preventing levels of biofouling. After a 7-day freshwater study results showed that MNPs prevent levels of biofouling upto 125% compared to the SG blank. The work uses bacterial enumeration, minimum inhibitory concentration (MIC), surface characterisation and slime and biomass analysis to complete a range of studies in assessing the level of fouling observed on the test substrates.


Assuntos
Anti-Infecciosos/farmacologia , Incrustação Biológica/prevenção & controle , Nanopartículas Metálicas/química , Anti-Infecciosos/química , Aderência Bacteriana , Biofilmes/efeitos dos fármacos , Biofilmes/crescimento & desenvolvimento , Biomassa , Água Doce/microbiologia , Géis/química , Nanopartículas Metálicas/ultraestrutura , Testes de Sensibilidade Microbiana , Microscopia Eletrônica de Varredura , Microscopia Eletrônica de Transmissão , Oxirredução , Tamanho da Partícula , Polímeros/química , Polimetil Metacrilato/química , Espectroscopia de Infravermelho com Transformada de Fourier , Propriedades de Superfície , Microbiologia da Água
5.
Analyst ; 133(7): 835-45, 2008 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-18575632

RESUMO

Anti-microbial materials have multiple applications in medicine, industry and commercial products. Recent research has proposed the use of nanoparticles in a range of materials, as some metal nanoparticles are known to possess antibacterial properties. The development of such materials presents both the chemist and the biologist with the challenge to effectively choose analytical methods that provide relevant information regarding these materials. Herein, we describe techniques for the characterization of the nanoparticle-doped materials and methods for the determination of their efficacy against biofilm formation.


Assuntos
Antibacterianos/química , Nanopartículas , Aderência Bacteriana , Biofilmes , Humanos , Microscopia Eletrônica , Nanomedicina , Infecções Relacionadas à Prótese/tratamento farmacológico , Difração de Raios X
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