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1.
Commun Biol ; 6(1): 358, 2023 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-37005489

RESUMO

Two prominent concepts for the sensing of shear stress by endothelium are the PIEZO1 channel as a mediator of mechanically activated calcium ion entry and the PECAM1 cell adhesion molecule as the apex of a triad with CDH5 and VGFR2. Here, we investigated if there is a relationship. By inserting a non-disruptive tag in native PIEZO1 of mice, we reveal in situ overlap of PIEZO1 with PECAM1. Through reconstitution and high resolution microscopy studies we show that PECAM1 interacts with PIEZO1 and directs it to cell-cell junctions. PECAM1 extracellular N-terminus is critical in this, but a C-terminal intracellular domain linked to shear stress also contributes. CDH5 similarly drives PIEZO1 to junctions but unlike PECAM1 its interaction with PIEZO1 is dynamic, increasing with shear stress. PIEZO1 does not interact with VGFR2. PIEZO1 is required in Ca2+-dependent formation of adherens junctions and associated cytoskeleton, consistent with it conferring force-dependent Ca2+ entry for junctional remodelling. The data suggest a pool of PIEZO1 at cell junctions, the coming together of PIEZO1 and PECAM1 mechanisms and intimate cooperation of PIEZO1 and adhesion molecules in tailoring junctional structure to mechanical requirement.


Assuntos
Células Endoteliais , Canais Iônicos , Camundongos , Animais , Canais Iônicos/genética , Canais Iônicos/metabolismo , Células Endoteliais/metabolismo , Molécula-1 de Adesão Celular Endotelial a Plaquetas/genética , Molécula-1 de Adesão Celular Endotelial a Plaquetas/metabolismo , Mecanotransdução Celular , Junções Intercelulares/metabolismo , Endotélio/metabolismo
2.
Sci Transl Med ; 15(685): eabo3823, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36857431

RESUMO

Hexanucleotide repeat expansions in C9ORF72 are the most common genetic cause of familial amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). Studies have shown that the hexanucleotide expansions cause the noncanonical translation of C9ORF72 transcripts into neurotoxic dipeptide repeat proteins (DPRs) that contribute to neurodegeneration. We show that a cell-penetrant peptide blocked the nuclear export of C9ORF72-repeat transcripts in HEK293T cells by competing with the interaction between SR-rich splicing factor 1 (SRSF1) and nuclear export factor 1 (NXF1). The cell-penetrant peptide also blocked the translation of toxic DPRs in neurons differentiated from induced neural progenitor cells (iNPCs), which were derived from individuals carrying C9ORF72-linked ALS mutations. This peptide also increased survival of iNPC-differentiated C9ORF72-ALS motor neurons cocultured with astrocytes. Oral administration of the cell-penetrant peptide reduced DPR translation and rescued locomotor deficits in a Drosophila model of mutant C9ORF72-mediated ALS/FTD. Intrathecal injection of this peptide into the brains of ALS/FTD mice carrying a C9ORF72 mutation resulted in reduced expression of DPRs in mouse brains. These findings demonstrate that disrupting the production of DPRs in cellular and animal models of ALS/FTD might be a strategy to ameliorate neurodegeneration in these diseases.


Assuntos
Esclerose Amiotrófica Lateral , Demência Frontotemporal , Humanos , Animais , Camundongos , Dipeptídeos , Proteína C9orf72 , Transporte Ativo do Núcleo Celular , Células HEK293 , Peptídeos , Neurônios Motores , RNA , Fatores de Processamento de Serina-Arginina
3.
Acta Neuropathol ; 144(3): 437-464, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-35876881

RESUMO

Dysfunction and degeneration of synapses is a common feature of amyotrophic lateral sclerosis and frontotemporal dementia (ALS/FTD). A GGGGCC hexanucleotide repeat expansion in the C9ORF72 gene is the main genetic cause of ALS/FTD (C9ALS/FTD). The repeat expansion leads to reduced expression of the C9orf72 protein. How C9orf72 haploinsufficiency contributes to disease has not been resolved. Here we identify the synapsin family of synaptic vesicle proteins, the most abundant group of synaptic phosphoproteins, as novel interactors of C9orf72 at synapses and show that C9orf72 plays a cell-autonomous role in the regulation of excitatory synapses. We mapped the interaction of C9orf72 and synapsin to the N-terminal longin domain of C9orf72 and the conserved C domain of synapsin, and show interaction of the endogenous proteins in synapses. Functionally, C9orf72 deficiency reduced the number of excitatory synapses and decreased synapsin levels at remaining synapses in vitro in hippocampal neuron cultures and in vivo in the hippocampal mossy fibre system of C9orf72 knockout mice. Consistent with synaptic dysfunction, electrophysiological recordings identified impaired excitatory neurotransmission and network function in hippocampal neuron cultures with reduced C9orf72 expression, which correlated with a severe depletion of synaptic vesicles from excitatory synapses in the hippocampus of C9orf72 knockout mice. Finally, neuropathological analysis of post-mortem sections of C9ALS/FTD patient hippocampus with C9orf72 haploinsufficiency revealed a marked reduction in synapsin, indicating that disruption of the interaction between C9orf72 and synapsin may contribute to ALS/FTD pathobiology. Thus, our data show that C9orf72 plays a cell-autonomous role in the regulation of neurotransmission at excitatory synapses by interaction with synapsin and modulation of synaptic vesicle pools, and identify a novel role for C9orf72 haploinsufficiency in synaptic dysfunction in C9ALS/FTD.


Assuntos
Esclerose Amiotrófica Lateral , Proteína C9orf72/metabolismo , Demência Frontotemporal , Sinapsinas/metabolismo , Esclerose Amiotrófica Lateral/metabolismo , Esclerose Amiotrófica Lateral/patologia , Animais , Proteína C9orf72/genética , Expansão das Repetições de DNA , Demência Frontotemporal/metabolismo , Demência Frontotemporal/patologia , Camundongos , Camundongos Knockout , Sinapses/patologia
4.
Phytother Res ; 36(7): 2952-2963, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35537691

RESUMO

This study investigated the vasorelaxant effects of schwarzinicine A, an alkaloid recently reported from Ficus schwarzii Koord. Regulation of calcium homeostasis in vascular smooth muscle cells (VSMC) is viewed as one of the main mechanisms for controlling blood pressure. L-type voltage-gated calcium channel (VGCC) blockers are commonly used for controlling hypertension. Recently, the transient receptor potential canonical (TRPC) channels were found in blood vessels of different animal species with evidence of their roles in the regulation of vascular contractility. In this study, we studied the mechanism of actions of schwarzinicine A focusing on its regulation of L-type VGCC and TRPC channels. Schwarzinicine A exhibited the highest vasorelaxant effect (123.1%) compared to other calcium channel blockers. It also overtly attenuated calcium-induced contractions of the rat isolated aortae in a calcium-free environment showing its mechanism to inhibit calcium influx. Fluorometric intracellular calcium recordings confirmed its inhibition of hTRPC3-, hTRPC4-, hTRPC5- and hTRPC6-mediated calcium influx into HEK cells with IC50 values of 3, 17, 19 and 7 µM, respectively. The evidence gathered in this study suggests that schwarzinicine A blocks multiple TRPC channels and L-type VGCC to exert a significant vascular relaxation response.


Assuntos
Canais de Potencial de Receptor Transitório , Vasodilatação , Animais , Cálcio/metabolismo , Bloqueadores dos Canais de Cálcio/farmacologia , Canais de Cálcio Tipo L/farmacologia , Ratos , Canais de Potencial de Receptor Transitório/farmacologia , Vasodilatadores/farmacologia
5.
Acta fisiátrica ; 29(1): 50-55, mar. 2022.
Artigo em Português | LILACS-Express | LILACS | ID: biblio-1363425

RESUMO

Apesar de atingirem padrões de alta clínica, pacientes com COVID-19 não retomam as atividades cotidianas devido à incapacidade, sendo o processo de reabilitação de interesse dos serviços de saúde e sociedade. Objetivos:Descrever o nível de funcionalidade do paciente pós-COVID-19 e resultados de um processo de reabilitação multidisciplinar.Métodos: Estudo observacional, descritivo, de abordagem quantitativa, relativo à avaliação das demandas e processo de reabilitação interdisciplinar. Resultados: 22 pacientes participaram do estudo, idade 48,46 anos (±12,63), 50% homens, sendo que 81,8% apresentavam comorbidades e 95,5% sobrepeso ou algum grau de obesidade. Todos apresentaram diminuição na QV (SF36) e não alcançaram a distância média esperada para o teste de 6 minutos, 20 pacientes apresentaram dispnéia para realizar as atividades cotidianas e 21 apresentaram limitação na Escala de Status Funcional pós-COVID-19 (PCSF). O resultado do processo de reabilitação com 20 pacientes, mostrou na comparação antes e depois, diferenças significativas na força muscular (,000) PeakFlow Meter (,000), Berg (,000), Barthel (,001), teste 6 minutos para freqüência cardíaca (,002) e distância percorrida (,000). Na SF-36 para os domínios de Estado Geral da Saúde (,058) e Aspectos Emocionais (,194) a diferença não foi significativa. Para as variáveis ordinais houve diferença significativa para PCSF (,000) e dispnéia (,000).Conclusão: O estudo aponta que a incapacidade do paciente teve maior correlação na entrada do serviço com o tempo de internação e que um processo de reabilitação interdisciplinar melhora na funcionalidade e QV do paciente com sequelas de COVID-19.


Despite reaching clinical discharge standards, patients with COVID-19 do not resume daily activities due to disability, and the rehabilitation process is of interest to health services and society. Objectives:To describe the post-COVID-19 patient's level of functionality and the result of a multidisciplinary rehabilitation process. Methods:observational, descriptive study, with a quantitative approach, related to the assessment of demands and interdisciplinary rehabilitation process. Results:22 patients participated in the study, age 48.46 years (±12.63), 50% were men, 81.8% had comorbidities and 95.5% were overweight or had some degree of obesity. All of them had a decrease in QoL (SF36) and did not reach the average distance expected for the 6-minute test, 20 patients had dyspnea to perform daily activities and 21 had limitations on the Post-Covid Functional Status Scale(PCSF). The result of the rehabilitation process with 20 patients, showed in the comparison before and after, significant differences in muscle strength (.000) Peak Flow Meter (.000), Berg (.000), Barthel (.001), 6-minute test for heart rate (.002) and distance traveled (.000). In the SF-36 for the General Health Status (.058) and Emotional Aspects (.194) domains, the difference was not significant. For the ordinal variables, there was a significant difference for post-COVID-19 Functional Status Scale (PCFS)(.000) and dyspnea (.000). Conclusion:The study points out that the patient's disability had a greater correlation at the entrance of the service with the length of hospitalization and that an interdisciplinary rehabilitation process improves the functionality and QOL of the patient with sequelae of COVID-19.

6.
J Biol Chem ; 298(2): 101546, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-34999117

RESUMO

Nonsense mutations, which occur in ∼11% of patients with genetic disorders, introduce premature termination codons (PTCs) that lead to truncated proteins and promote nonsense-mediated mRNA decay. Aminoglycosides such as G418 permit PTC readthrough and so may be used to address this problem. However, their effects are variable between patients, making clinical use of aminoglycosides challenging. In this study, we tested whether TRPC nonselective cation channels contribute to the variable PTC readthrough effect of aminoglycosides by controlling their cellular uptake. Indeed, a recently reported selective TRPC5 inhibitor, AC1903, consistently suppressed G418 uptake and G418-induced PTC readthrough in the DMS-114 cancer cell line and junctional epidermolysis bullosa (JEB) patient-derived keratinocytes. Interestingly, the effect of AC1903 in DMS-114 cells was mimicked by nonselective TRPC inhibitors, but not by well-characterized inhibitors of TRPC1/4/5 (Pico145, GFB-8438) or TRPC3/6/7 (SAR7334), suggesting that AC1903 may work through additional or undefined targets. Indeed, in our experiments, AC1903 inhibited multiple TRPC channels including TRPC3, TRPC4, TRPC5, TRPC6, TRPC4-C1, and TRPC5-C1, as well as endogenous TRPC1:C4 channels in A498 renal cancer cells, all with low micromolar IC50 values (1.8-18 µM). We also show that AC1903 inhibited TRPV4 channels, but had weak or no effects on TRPV1 and no effect on the nonselective cation channel PIEZO1. Our study reveals that AC1903 has previously unrecognized targets, which need to be considered when interpreting results from experiments with this compound. In addition, our data strengthen the hypothesis that nonselective calcium channels are involved in aminoglycoside uptake.


Assuntos
Aminoglicosídeos , Códon sem Sentido , Indazóis , Canais de Cátion TRPC , Aminoglicosídeos/farmacologia , Códon sem Sentido/efeitos dos fármacos , Humanos , Indazóis/farmacologia , Inibidores da Síntese de Proteínas , Canais de Cátion TRPC/antagonistas & inibidores , Canais de Cátion TRPC/genética , Canais de Cátion TRPC/metabolismo
7.
Front Cell Neurosci ; 16: 1061559, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36619668

RESUMO

Disruption to protein homeostasis caused by lysosomal dysfunction and associated impairment of autophagy is a prominent pathology in amyotrophic lateral sclerosis and frontotemporal dementia (ALS/FTD). The most common genetic cause of ALS/FTD is a G4C2 hexanucleotide repeat expansion in C9orf72 (C9ALS/FTD). Repeat-associated non-AUG (RAN) translation of G4C2 repeat transcripts gives rise to dipeptide repeat (DPR) proteins that have been shown to be toxic and may contribute to disease etiology. Genetic variants in TMEM106B have been associated with frontotemporal lobar degeneration with TDP-43 pathology and disease progression in C9ALS/FTD. TMEM106B encodes a lysosomal transmembrane protein of unknown function that is involved in various aspects of lysosomal biology. How TMEM106B variants affect C9ALS/FTD is not well understood but has been linked to changes in TMEM106B protein levels. Here, we investigated TMEM106B function in the context of C9ALS/FTD DPR pathology. We report that knockdown of TMEM106B expression exacerbates the accumulation of C9ALS/FTD-associated cytotoxic DPR proteins in cell models expressing RAN-translated or AUG-driven DPRs as well as in C9ALS/FTD-derived iAstrocytes with an endogenous G4C2 expansion by impairing autophagy. Loss of TMEM106B caused a block late in autophagy by disrupting autophagosome to autolysosome maturation which coincided with impaired lysosomal acidification, reduced cathepsin activity, and juxtanuclear clustering of lysosomes. Lysosomal clustering required Rab7A and coincided with reduced Arl8b-mediated anterograde transport of lysosomes to the cell periphery. Increasing Arl8b activity in TMEM106B-deficient cells not only restored the distribution of lysosomes, but also fully rescued autophagy and DPR protein accumulation. Thus, we identified a novel function of TMEM106B in autophagosome maturation via Arl8b. Our findings indicate that TMEM106B variants may modify C9ALS/FTD by regulating autophagic clearance of DPR proteins. Caution should therefore be taken when considering modifying TMEM106B expression levels as a therapeutic approach in ALS/FTD.

8.
Cell Chem Biol ; 29(2): 339-350.e10, 2022 02 17.
Artigo em Inglês | MEDLINE | ID: mdl-34324879

RESUMO

There are many efficient ways to connect proteins at termini. However, connecting at a loop is difficult because of lower flexibility and variable environment. Here, we have developed DogCatcher, a protein that forms a spontaneous isopeptide bond with DogTag peptide. DogTag/DogCatcher was generated initially by splitting a Streptococcus pneumoniae adhesin. We optimized DogTag/DogCatcher through rational design and evolution, increasing reaction rate by 250-fold and establishing millimolar solubility of DogCatcher. When fused to a protein terminus, DogTag/DogCatcher reacts slower than SpyTag003/SpyCatcher003. However, inserted in loops of a fluorescent protein or enzyme, DogTag reacts much faster than SpyTag003. Like many membrane proteins, the ion channel TRPC5 has no surface-exposed termini. DogTag in a TRPC5 extracellular loop allowed normal calcium flux and specific covalent labeling on cells in 1 min. DogTag/DogCatcher reacts under diverse conditions, at nanomolar concentrations, and to 98% conversion. Loop-friendly ligation should expand the toolbox for creating protein architectures.


Assuntos
Proteínas Luminescentes/química , Oxirredutases/química , Peptídeos/química , Células Cultivadas , Escherichia coli/citologia , Humanos , Proteínas Luminescentes/metabolismo , Modelos Moleculares , Oxirredutases/metabolismo , Peptídeos/metabolismo , Conformação Proteica , Solubilidade
9.
Anticancer Res ; 40(12): 6799-6815, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33288573

RESUMO

BACKGROUND/AIM: Glioblastomas (GBMs) are the most malignant primary brain tumor. New treatment strategies against the disease are urgently needed, as therapies are not completely efficient. In this study, we evaluated the antitumorigenic activity of the carotenoid fucoxanthin (Fx) on human GBM cells in vitro. MATERIALS AND METHODS: GBM1 cell viability and proliferation was assessed by MTT reduction, Ki67 and single cell cloning assays. GBM1 migration and invasion were analyzed by wound healing and Transwell assays. Apoptosis and necrosis were analyzed by flow cytometry, and the mitochondrial membrane potential (ΔΨm) by the selective fluorescent dye tetramethylrhodamine ethyl ester. Cell morphology was analyzed through scanning electron microscopy and transmission electron microscopy. Fx anti-angiogenic effect was assessed by the CAM ex ovo assay. RESULTS: Fx decreased cell viability in a concentration-dependent manner (40-100 µ M) in GBM1, A172 and C6 cell lines and was not cytotoxic to murine astrocytes. In addition, Fx inhibited the proliferation and clonogenic potential, and decreased migration and invasion of GBM1 cells. Furthermore, Fx induced apoptosis, loss of ΔΨm and ultrastructural alterations in GBM1. Fx-treated GBM1 cells-conditioned medium reduced the quail yolk membrane vascularity. CONCLUSION: Fx induces cytotoxicity, anti-proliferative, anti-invasive and anti-angiogenic effects on GBM1 cells.


Assuntos
Antineoplásicos Fitogênicos/farmacologia , Xantofilas/farmacologia , Animais , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Meios de Cultivo Condicionados/farmacologia , Relação Dose-Resposta a Droga , Glioblastoma , Humanos , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Mitocôndrias/ultraestrutura
10.
Int J Mol Sci ; 20(20)2019 Oct 19.
Artigo em Inglês | MEDLINE | ID: mdl-31635081

RESUMO

Niemann-Pick Type C (NP-C) is a rare disorder of lipid metabolism caused by mutations within the NPC1 and NPC2 genes. NP-C is a neurovisceral disease leading to a heterogeneous, multisystemic spectrum of symptoms in those affected. Until now, there is no investigative tool to demonstrate the significance of single variants within the NPC genes. Hence, the aim of the study was to establish a test that allows for an objective assessment of the pathological potential of NPC1 gene variants. Chinese hamster ovary cells defective in the NPC1 gene accumulate cholesterol in lysosomal storage organelles. The cells were transfected with NPC1-GFP plasmid vectors carrying distinct sequence variants. Filipin staining was used to test for complementation of the phenotype. The known variant p.Ile1061Thr showed a significantly impaired cholesterol clearance after 12 and 24 h compared to the wild type. Among the investigated variants, p.Ser954Leu and p.Glu1273Lys showed decelerated cholesterol clearance as well. The remaining variants p.Gln60His, p.Val494Met, and p.Ile787Val showed a cholesterol clearance indistinguishable from wild type. Further, p.Ile1061Thr acquired an enhanced clearance ability upon 25-hydroxycholesterol treatment. We conclude that the variants that caused an abnormal clearance phenotype are highly likely to be of clinical relevance. Moreover, we present a system that can be utilized to screen for new drugs.


Assuntos
Teste de Complementação Genética , Variação Genética , Peptídeos e Proteínas de Sinalização Intracelular/genética , Alelos , Sequência de Aminoácidos , Animais , Células CHO , Células Cultivadas , Colesterol/metabolismo , Mapeamento Cromossômico , Cricetulus , Frequência do Gene , Estudos de Associação Genética , Genótipo , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/química , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Modelos Moleculares , Proteína C1 de Niemann-Pick , Doença de Niemann-Pick Tipo C/diagnóstico , Doença de Niemann-Pick Tipo C/genética , Doença de Niemann-Pick Tipo C/metabolismo , Fenótipo , Conformação Proteica , Relação Estrutura-Atividade
11.
Br J Pharmacol ; 176(20): 3924-3938, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31277085

RESUMO

BACKGROUND AND PURPOSE: The TRPC1, TRPC4, and TRPC5 proteins form homotetrameric or heterotetrameric, calcium-permeable cation channels that are involved in various disease states. Recent research has yielded specific and potent xanthine-based TRPC1/4/5 inhibitors. Here, we investigated the possibility of xanthine-based activators of these channels. EXPERIMENTAL APPROACH: An analogue of the TRPC1/4/5 inhibitor Pico145, AM237, was synthesized and its activity was investigated using HEK cells overexpressing TRPC4, TRPC5, TRPC4-C1, TRPC5-C1, TRPC1:C4 or TRPC1:C5 channels, and in A498 cells expressing native TRPC1:C4 channels. TRPC1/4/5 channel activities were assayed by measuring intracellular concentration of Ca2+ ([Ca2+ ]i ) and by patch-clamp electrophysiology. Selectivity of AM237 was tested against TRPC3, TRPC6, TRPV4, or TRPM2 channels. KEY RESULTS: AM237 potently activated TRPC5:C5 channels (EC50 15-20 nM in [Ca2+ ]i assay) and potentiated their activation by sphingosine-1-phosphate but suppressed activation evoked by (-)-englerin A (EA). In patch-clamp studies, AM237 activated TRPC5:C5 channels, with greater effect at positive voltages, but with lower efficacy than EA. Pico145 competitively inhibited AM237-induced TRPC5:C5 activation. AM237 did not activate TRPC4:C4, TRPC4-C1, TRPC5-C1, TRPC1:C5, and TRPC1:C4 channels, or native TRPC1:C4 channels in A498 cells, but potently inhibited EA-dependent activation of these channels with IC50 values ranging from 0.9 to 7 nM. AM237 (300 nM) did not activate or inhibit TRPC3, TRPC6, TRPV4, or TRPM2 channels. CONCLUSIONS AND IMPLICATIONS: This study suggests the possibility for selective activation of TRPC5 channels by xanthine derivatives and supports the general principle that xanthine-based compounds can activate, potentiate, or inhibit these channels depending on subunit composition.


Assuntos
Compostos Heterocíclicos com 2 Anéis/farmacologia , Purinas/farmacologia , Canais de Cátion TRPC/metabolismo , Cálcio/análise , Cálcio/metabolismo , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Relação Dose-Resposta a Droga , Células HEK293 , Compostos Heterocíclicos com 2 Anéis/síntese química , Compostos Heterocíclicos com 2 Anéis/química , Humanos , Estrutura Molecular , Técnicas de Patch-Clamp , Purinas/síntese química , Purinas/química , Relação Estrutura-Atividade , Canais de Cátion TRPC/antagonistas & inibidores
12.
Brain ; 142(3): 586-605, 2019 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-30698736

RESUMO

As clinical evidence supports a negative impact of dysfunctional energy metabolism on the disease progression in amyotrophic lateral sclerosis, it is vital to understand how the energy metabolic pathways are altered and whether they can be restored to slow disease progression. Possible approaches include increasing or rerouting catabolism of alternative fuel sources to supplement the glycolytic and mitochondrial pathways such as glycogen, ketone bodies and nucleosides. To analyse the basis of the catabolic defect in amyotrophic lateral sclerosis we used a novel phenotypic metabolic array. We profiled fibroblasts and induced neuronal progenitor-derived human induced astrocytes from C9orf72 amyotrophic lateral sclerosis patients compared to normal controls, measuring the rates of production of reduced nicotinamide adenine dinucleotides from 91 potential energy substrates. This approach shows for the first time that C9orf72 human induced astrocytes and fibroblasts have an adenosine to inosine deamination defect caused by reduction of adenosine deaminase, which is also observed in induced astrocytes from sporadic patients. Patient-derived induced astrocyte lines were more susceptible to adenosine-induced toxicity, which could be mimicked by inhibiting adenosine deaminase in control lines. Furthermore, adenosine deaminase inhibition in control induced astrocytes led to increased motor neuron toxicity in co-cultures, similar to the levels observed with patient derived induced astrocytes. Bypassing metabolically the adenosine deaminase defect by inosine supplementation was beneficial bioenergetically in vitro, increasing glycolytic energy output and leading to an increase in motor neuron survival in co-cultures with induced astrocytes. Inosine supplementation, in combination with modulation of the level of adenosine deaminase may represent a beneficial therapeutic approach to evaluate in patients with amyotrophic lateral sclerosis.


Assuntos
Adenosina Desaminase/metabolismo , Esclerose Amiotrófica Lateral/metabolismo , Neurônios Motores/metabolismo , Adenosina Desaminase/fisiologia , Adulto , Esclerose Amiotrófica Lateral/fisiopatologia , Animais , Astrócitos/metabolismo , Proteína C9orf72/metabolismo , Morte Celular , Sobrevivência Celular , Células Cultivadas , Técnicas de Cocultura , Progressão da Doença , Metabolismo Energético/fisiologia , Feminino , Fibroblastos/metabolismo , Humanos , Inosina/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Pessoa de Meia-Idade , Ratos , Ratos Sprague-Dawley , Células-Tronco/metabolismo
13.
Mol Psychiatry ; 24(11): 1748-1768, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-29728705

RESUMO

RLIM, also known as RNF12, is an X-linked E3 ubiquitin ligase acting as a negative regulator of LIM-domain containing transcription factors and participates in X-chromosome inactivation (XCI) in mice. We report the genetic and clinical findings of 84 individuals from nine unrelated families, eight of whom who have pathogenic variants in RLIM (RING finger LIM domain-interacting protein). A total of 40 affected males have X-linked intellectual disability (XLID) and variable behavioral anomalies with or without congenital malformations. In contrast, 44 heterozygous female carriers have normal cognition and behavior, but eight showed mild physical features. All RLIM variants identified are missense changes co-segregating with the phenotype and predicted to affect protein function. Eight of the nine altered amino acids are conserved and lie either within a domain essential for binding interacting proteins or in the C-terminal RING finger catalytic domain. In vitro experiments revealed that these amino acid changes in the RLIM RING finger impaired RLIM ubiquitin ligase activity. In vivo experiments in rlim mutant zebrafish showed that wild type RLIM rescued the zebrafish rlim phenotype, whereas the patient-specific missense RLIM variants failed to rescue the phenotype and thus represent likely severe loss-of-function mutations. In summary, we identified a spectrum of RLIM missense variants causing syndromic XLID and affecting the ubiquitin ligase activity of RLIM, suggesting that enzymatic activity of RLIM is required for normal development, cognition and behavior.


Assuntos
Retardo Mental Ligado ao Cromossomo X/genética , Ubiquitina-Proteína Ligases/genética , Ubiquitina-Proteína Ligases/metabolismo , Adolescente , Adulto , Animais , Criança , Pré-Escolar , Transtorno da Conduta/genética , Feminino , Genes Ligados ao Cromossomo X , Células HEK293 , Humanos , Recém-Nascido , Deficiência Intelectual/genética , Deficiência Intelectual/metabolismo , Masculino , Retardo Mental Ligado ao Cromossomo X/metabolismo , Camundongos , Pessoa de Meia-Idade , Mutação , Linhagem , Fatores de Transcrição/genética , Ubiquitinação , Inativação do Cromossomo X , Peixe-Zebra , Proteínas de Peixe-Zebra/genética , Proteínas de Peixe-Zebra/metabolismo
14.
J Neurosci ; 38(43): 9186-9201, 2018 10 24.
Artigo em Inglês | MEDLINE | ID: mdl-30181139

RESUMO

The putative cache (Ca2+ channel and chemotaxis receptor) domain containing 1 (CACHD1) protein has predicted structural similarities to members of the α2δ voltage-gated Ca2+ channel auxiliary subunit family. CACHD1 mRNA and protein were highly expressed in the male mammalian CNS, in particular in the thalamus, hippocampus, and cerebellum, with a broadly similar tissue distribution to CaV3 subunits, in particular CaV3.1. In expression studies, CACHD1 increased cell-surface localization of CaV3.1, and these proteins were in close proximity at the cell surface, consistent with the formation of CACHD1-CaV3.1 complexes. In functional electrophysiological studies, coexpression of human CACHD1 with CaV3.1, CaV3.2, and CaV3.3 caused a significant increase in peak current density and corresponding increases in maximal conductance. By contrast, α2δ-1 had no effect on peak current density or maximal conductance in CaV3.1, CaV3.2, or CaV3.3. A comparison of CACHD1-mediated increases in CaV3.1 current density and gating currents revealed an increase in channel open probability. In hippocampal neurons from male and female embryonic day 19 rats, CACHD1 overexpression increased CaV3-mediated action potential firing frequency and neuronal excitability. These data suggest that CACHD1 is structurally an α2δ-like protein that functionally modulates CaV3 voltage-gated calcium channel activity.SIGNIFICANCE STATEMENT This is the first study to characterize the Ca2+ channel and chemotaxis receptor domain containing 1 (CACHD1) protein. CACHD1 is widely expressed in the CNS, in particular in the thalamus, hippocampus, and cerebellum. CACHD1 distribution is similar to that of low voltage-activated (CaV3, T-type) calcium channels, in particular to CaV3.1, a protein that regulates neuronal excitability and is a potential therapeutic target in conditions such as epilepsy and pain. CACHD1 is structurally an α2δ-like protein that functionally increases CaV3 calcium current. CACHD1 increases the presence of CaV3.1 at the cell surface, forms complexes with CaV3.1 at the cell surface, and causes an increase in channel open probability. In hippocampal neurons, CACHD1 causes increases in neuronal firing. Thus, CACHD1 represents a novel protein that modulates CaV3 activity.


Assuntos
Canais de Cálcio Tipo L/metabolismo , Canais de Cálcio Tipo T/biossíntese , Hipocampo/metabolismo , Proteínas de Membrana/metabolismo , Animais , Canais de Cálcio Tipo L/química , Canais de Cálcio Tipo L/genética , Canais de Cálcio Tipo T/química , Canais de Cálcio Tipo T/genética , Feminino , Células HEK293 , Humanos , Masculino , Proteínas de Membrana/química , Proteínas de Membrana/genética , Ratos , Ratos Wistar
15.
Artigo em Inglês | MEDLINE | ID: mdl-30081549

RESUMO

The Education Against Tobacco (EAT) network delivers smoking prevention advice in secondary schools, typically using the mirroring approach (i.e., a "selfie" altered with a face-aging app and shared with a class). In November 2017, however, the German assembly of EAT opted to expand its remit to include nursing students. To assess the transferability of the existing approach, we implemented it with the self-developed face-aging app "Smokerface" (=mixed - methods approach) in six nursing schools. Anonymous questionnaires were used to assess the perceptions of 197 students (age 18⁻40 years; 83.8% female; 26.4% smokers; 23.3% daily smokers) collecting qualitative and quantitative data for our cross-sectional study. Most students perceived the intervention to be fun (73.3%), but a minority disagreed that their own animated selfie (25.9%) or the reaction of their peers (29.5%) had motivated them to stop smoking. The impact on motivation not to smoke was considerably lower than experienced with seventh graders (63.2% vs. 42.0%; notably, more smokers also disagreed (45.1%) than agreed (23.5%) with this statement. Agreement rates on the motivation not to smoke item were higher in females than in males and in year 2⁻3 than in year 1 students. Potential improvements included greater focus on pathology (29%) and discussing external factors (26%). Overall, the intervention seemed to be appealing for nursing students.


Assuntos
Abandono do Hábito de Fumar/métodos , Prevenção do Hábito de Fumar/métodos , Estudantes de Enfermagem/psicologia , Estudantes de Enfermagem/estatística & dados numéricos , Adolescente , Adulto , Estudos Transversais , Face , Feminino , Alemanha , Humanos , Masculino , Pessoa de Meia-Idade , Fotografação , Adulto Jovem
16.
Cells ; 7(6)2018 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-29865154

RESUMO

Proteins of the TRPC family can form many homo- and heterotetrameric cation channels permeable to Na⁺, K⁺ and Ca2+. In this review, we focus on channels formed by the isoforms TRPC1, TRPC4 and TRPC5. We review evidence for the formation of different TRPC1/4/5 tetramers, give an overview of recently developed small-molecule TRPC1/4/5 activators and inhibitors, highlight examples of biological roles of TRPC1/4/5 channels in different tissues and pathologies, and discuss how high-quality chemical probes of TRPC1/4/5 modulators can be used to understand the involvement of TRPC1/4/5 channels in physiological and pathophysiological processes.

17.
Hum Mol Genet ; 26(23): 4668-4679, 2017 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-28973175

RESUMO

Defective axonal transport is an early neuropathological feature of amyotrophic lateral sclerosis (ALS). We have previously shown that ALS-associated mutations in Cu/Zn superoxide dismutase 1 (SOD1) impair axonal transport of mitochondria in motor neurons isolated from SOD1 G93A transgenic mice and in ALS mutant SOD1 transfected cortical neurons, but the underlying mechanisms remained unresolved. The outer mitochondrial membrane protein mitochondrial Rho GTPase 1 (Miro1) is a master regulator of mitochondrial axonal transport in response to cytosolic calcium (Ca2+) levels ([Ca2+]c) and mitochondrial damage. Ca2+ binding to Miro1 halts mitochondrial transport by modifying its interaction with kinesin-1 whereas mitochondrial damage induces Phosphatase and Tensin Homolog (PTEN)-induced Putative Kinase 1 (PINK1) and Parkin-dependent degradation of Miro1 and consequently stops transport. To identify the mechanism underlying impaired axonal transport of mitochondria in mutant SOD1-related ALS we investigated [Ca2+]c and Miro1 levels in ALS mutant SOD1 expressing neurons. We found that expression of ALS mutant SOD1 reduced the level of endogenous Miro1 but did not affect [Ca2+]c. ALS mutant SOD1 induced reductions in Miro1 levels were Parkin dependent. Moreover, both overexpression of Miro1 and ablation of PINK1 rescued the mitochondrial axonal transport deficit in ALS mutant SOD1-expressing cortical and motor neurons. Together these results provide evidence that ALS mutant SOD1 inhibits axonal transport of mitochondria by inducing PINK1/Parkin-dependent Miro1 degradation.


Assuntos
Esclerose Amiotrófica Lateral/metabolismo , Transporte Axonal/fisiologia , Proteínas Mitocondriais/metabolismo , Superóxido Dismutase-1/genética , Superóxido Dismutase-1/metabolismo , Proteínas rho de Ligação ao GTP/metabolismo , Esclerose Amiotrófica Lateral/enzimologia , Esclerose Amiotrófica Lateral/genética , Animais , Axônios/metabolismo , Cálcio/metabolismo , Citosol/metabolismo , Modelos Animais de Doenças , Células HEK293 , Células HeLa , Humanos , Camundongos Transgênicos , Mitocôndrias/metabolismo , Neurônios Motores/metabolismo , Mutação , Proteínas Quinases/metabolismo , Ratos
18.
Sci Rep ; 7(1): 12389, 2017 09 28.
Artigo em Inglês | MEDLINE | ID: mdl-28959041

RESUMO

Calcitonin receptor-like receptor (CLR) and the receptor activity-modifying protein 2 (RAMP2) comprise a receptor for adrenomedullin (AM). Although it is known that AM induces internalization of CLR•RAMP2, little is known about the molecular mechanisms that regulate the trafficking of CLR•RAMP2. Using HEK and HMEC-1 cells, we observed that AM-induced activation of CLR•RAMP2 promoted ubiquitination of CLR. A mutant (CLRΔ9KR), lacking all intracellular lysine residues was functional and trafficked similar to the wild-type receptor, but was not ubiquitinated. Degradation of CLR•RAMP2 and CLRΔ9KR•RAMP2 was not dependent on the duration of AM stimulation or ubiquitination and occurred via a mechanism that was partially prevented by peptidase inhibitors. Degradation of CLR•RAMP2 was sensitive to overexpression of hepatocyte growth factor-regulated tyrosine kinase substrate (HRS), but not to HRS knockdown, whereas CLRΔ9KR•RAMP2 degradation was unaffected. Overexpression, but not knockdown of HRS, promoted hyperubiquitination of CLR under basal conditions. Thus, we propose a role for ubiquitin and HRS in the regulation of AM-induced degradation of CLR•RAMP2.


Assuntos
Adrenomedulina/metabolismo , Complexos Endossomais de Distribuição Requeridos para Transporte/metabolismo , Fosfoproteínas/metabolismo , Receptores de Adrenomedulina/metabolismo , Ubiquitinação/fisiologia , Proteína Semelhante a Receptor de Calcitonina/genética , Proteína Semelhante a Receptor de Calcitonina/metabolismo , Complexos Endossomais de Distribuição Requeridos para Transporte/genética , Técnicas de Silenciamento de Genes , Células HEK293 , Humanos , Fosfoproteínas/genética , Transporte Proteico , Proteólise , RNA Interferente Pequeno/metabolismo , Proteína 2 Modificadora da Atividade de Receptores/genética , Proteína 2 Modificadora da Atividade de Receptores/metabolismo , Ubiquitina/metabolismo
19.
Nat Commun ; 8: 16063, 2017 07 05.
Artigo em Inglês | MEDLINE | ID: mdl-28677678

RESUMO

Hexanucleotide repeat expansions in the C9ORF72 gene are the commonest known genetic cause of amyotrophic lateral sclerosis and frontotemporal dementia. Expression of repeat transcripts and dipeptide repeat proteins trigger multiple mechanisms of neurotoxicity. How repeat transcripts get exported from the nucleus is unknown. Here, we show that depletion of the nuclear export adaptor SRSF1 prevents neurodegeneration and locomotor deficits in a Drosophila model of C9ORF72-related disease. This intervention suppresses cell death of patient-derived motor neuron and astrocytic-mediated neurotoxicity in co-culture assays. We further demonstrate that either depleting SRSF1 or preventing its interaction with NXF1 specifically inhibits the nuclear export of pathological C9ORF72 transcripts, the production of dipeptide-repeat proteins and alleviates neurotoxicity in Drosophila, patient-derived neurons and neuronal cell models. Taken together, we show that repeat RNA-sequestration of SRSF1 triggers the NXF1-dependent nuclear export of C9ORF72 transcripts retaining expanded hexanucleotide repeats and reveal a novel promising therapeutic target for neuroprotection.


Assuntos
Esclerose Amiotrófica Lateral/metabolismo , Proteína C9orf72/metabolismo , Demência Frontotemporal/metabolismo , Proteínas de Transporte Nucleocitoplasmático/metabolismo , Proteínas de Ligação a RNA/metabolismo , Fatores de Processamento de Serina-Arginina/metabolismo , Adulto , Idoso , Esclerose Amiotrófica Lateral/etiologia , Animais , Astrócitos/fisiologia , Linhagem Celular , Técnicas de Cocultura , Modelos Animais de Doenças , Drosophila , Feminino , Demência Frontotemporal/etiologia , Humanos , Masculino , Camundongos , Pessoa de Meia-Idade , Proteínas Nucleares/metabolismo , Ratos , Fatores de Transcrição/metabolismo
20.
Mar Pollut Bull ; 114(2): 831-836, 2017 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-27847170

RESUMO

Fossil fuels, e.g. gasoline and diesel oil, account for substantial share of the pollution that affects marine ecosystems. Environmental metabolomics is an emerging field that may help unravel the effect of these xenobiotics on seaweeds and provide methodologies for biomonitoring coastal ecosystems. In the present study, FTIR and multivariate analysis were used to discriminate metabolic profiles of Ulva lactuca after in vitro exposure to diesel oil and gasoline, in combinations of concentrations (0.001%, 0.01%, 0.1%, and 1.0% - v/v) and times of exposure (30min, 1h, 12h, and 24h). PCA and HCA performed on entire mid-infrared spectral window were able to discriminate diesel oil-exposed thalli from the gasoline-exposed ones. HCA performed on spectral window related to the protein absorbance (1700-1500cm-1) enabled the best discrimination between gasoline-exposed samples regarding the time of exposure, and between diesel oil-exposed samples according to the concentration. The results indicate that the combination of FTIR with multivariate analysis is a simple and efficient methodology for metabolic profiling with potential use for biomonitoring strategies.


Assuntos
Monitoramento Ambiental/métodos , Óleos Combustíveis/análise , Metaboloma/efeitos dos fármacos , Ulva/efeitos dos fármacos , Brasil , Gasolina/análise , Metabolômica , Modelos Teóricos , Análise Multivariada , Análise de Componente Principal , Espectroscopia de Infravermelho com Transformada de Fourier , Ulva/metabolismo
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