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1.
J Allergy Clin Immunol ; 149(4): 1348-1357, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-34653514

RESUMO

BACKGROUND: Type-17 inflammation characterizes psoriasis, a chronic skin disease. Because several inflammatory cytokines contribute to psoriasis pathogenesis, inhibiting the simultaneous production of these cytokines in TH17 cells may be beneficial in psoriasis. We found that Cav1.4, encoded by CACNA1F, was the only Cav1 calcium channel expressed in TH17 cells. OBJECTIVE: We sought to investigate the role of Cav1.4 expression in early TH17-activation events and effector functions, as well as its association with TH17 signature genes in lesional psoriatic (LP) skins. METHODS: Transcriptional gene signatures associated with CACNA1F expression were examined in LP skins by RT-PCR and in situ hybridization. Cav1 inhibitor and/or shRNA lentivectors were used to assess the contribution of Cav1.4 in TH17 activation and effector functions in a 3-dimensional skin reconstruction model. RESULTS: CACNA1F expression correlated with inflammatory cytokine expression that characterizes LP skins and was preferentially associated with RORC expression in CD4+ and CD4- cells from LP biopsies. Nicardipine, a Cav1 channel antagonist, markedly reduced inflammatory cytokine production by TH17 cells from blood or LP skin. This was associated with decreased TCR-induced early calcium events at cell membrane and proximal signaling events. The knockdown of Cav1.4 in TH17 cells impaired cytokine production. Finally, Cav1 inhibition reduced the expression of the keratinocyte genes characteristic of TH17-mediated psoriasis inflammation in human skin equivalents. CONCLUSIONS: Cav1.4 channels promote TH17-cell functions both at the periphery and in inflammatory psoriatic skin.


Assuntos
Canais de Cálcio , Psoríase , Canais de Cálcio/metabolismo , Citocinas/metabolismo , Humanos , Inflamação/metabolismo , Psoríase/metabolismo , Pele/patologia , Células Th17/patologia
2.
Zygote ; 30(2): 267-278, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-34530953

RESUMO

It has previously been reported that in ex vivo planar explants prepared from Xenopus laevis embryos, the intracellular pH (pHi) increases in cells of the dorsal ectoderm from stage 10.5 to 11.5 (i.e. 11-12.5 hpf). It was proposed that such increases (potentially due to H+ being extruded, sequestered, or buffered in some manner), play a role in regulating neural induction. Here, we used an extracellular ion-selective electrode to non-invasively measure H+ fluxes at eight locations around the equatorial circumference of intact X. laevis embryos between stages 9-12 (˜7-13.25 hpf). We showed that at stages 9-11, there was a small H+ efflux recorded from all the measuring positions. At stage 12 there was a small, but significant, increase in the efflux of H+ from most locations, but the efflux from the dorsal side of the embryo was significantly greater than from the other positions. Embryos were also treated from stages 9-12 with bafilomycin A1, to block the activity of the ATP-driven H+ pump. By stage 22 (24 hpf), these embryos displayed retarded development, arresting before the end of gastrulation and therefore did not display the usual anterior and neural structures, which were observed in the solvent-control embryos. In addition, expression of the early neural gene, Zic3, was absent in treated embryos compared with the solvent controls. Together, our new in vivo data corroborated and extended the earlier explant-derived report describing changes in pHi that were suggested to play a role during neural induction in X. laevis embryos.


Assuntos
Ectoderma , Desenvolvimento Embrionário , Animais , Ectoderma/fisiologia , Regulação da Expressão Gênica no Desenvolvimento , Sistema Nervoso , Xenopus laevis/metabolismo
3.
Allergy ; 77(2): 525-539, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-34181765

RESUMO

BACKGROUND: Voltage-gated calcium (Cav 1) channels contribute to T-lymphocyte activation. Cav 1.2 and Cav 1.3 channels are expressed in Th2 cells but their respective roles are unknown, which is investigated herein. METHODS: We generated mice deleted for Cav 1.2 in T cells or Cav 1.3 and analyzed TCR-driven signaling. In this line, we developed original fast calcium imaging to measure early elementary calcium events (ECE). We also tested the impact of Cav 1.2 or Cav 1.3 deletion in models of type 2 airway inflammation. Finally, we checked whether the expression of both Cav 1.2 and Cav 1.3 in T cells from asthmatic children correlates with Th2-cytokine expression. RESULTS: We demonstrated non-redundant and synergistic functions of Cav 1.2 and Cav 1.3 in Th2 cells. Indeed, the deficiency of only one channel in Th2 cells triggers TCR-driven hyporesponsiveness with weakened tyrosine phosphorylation profile, a strong decrease in initial ECE and subsequent reduction in the global calcium response. Moreover, Cav 1.3 has a particular role in calcium homeostasis. In accordance with the singular roles of Cav 1.2 and Cav 1.3 in Th2 cells, deficiency in either one of these channels was sufficient to inhibit cardinal features of type 2 airway inflammation. Furthermore, Cav 1.2 and Cav 1.3 must be co-expressed within the same CD4+ T cell to trigger allergic airway inflammation. Accordingly with the concerted roles of Cav 1.2 and Cav 1.3, the expression of both channels by activated CD4+ T cells from asthmatic children was associated with increased Th2-cytokine transcription. CONCLUSIONS: Thus, Cav 1.2 and Cav 1.3 act as a duo, and targeting only one of these channels would be efficient in allergy treatment.


Assuntos
Asma , Canais de Cálcio , Animais , Asma/metabolismo , Cálcio/metabolismo , Canais de Cálcio/metabolismo , Citocinas/metabolismo , Humanos , Inflamação/metabolismo , Camundongos , Receptores de Antígenos de Linfócitos T/metabolismo , Células Th2/metabolismo
4.
Eur Spine J ; 30(7): 1888-1895, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-34032931

RESUMO

PURPOSE: To investigate the test-retest, intra- and inter-rater reliabilities of an ultrasound (US) reflection coefficient (RC) index measured in a lumbar vertebra to reflect bone strength on children with AIS. METHODS: Fifty-eight participants (47F; 11M) were scanned by an US imager in standing position. Twenty-four were scanned twice for a test-retest study. The RC index measures the US signal reflected from L5 to indicate bone strength. Five measurements were obtained using three different methods: (i) the maximum RC (MRC) values on the left and right sides, (ii) the average RC (ARC) values on left and right sides, and (iii) the combined average RC (CARC) from both sides. Only rater 1 measured the 24 repeated US scans once. Raters 1 and 2 measured the RC index twice on all 58 images in 1 week apart. The intraclass correlation coefficient ICC [3, 1] for test-retest and ICC [2, 1] for intra- and inter-rater reliabilities as well as the standard error of measurements (SEM) were reported. RESULTS: The means of scan 1 versus scan 2 were 0.16 ± 0.08 versus 0.16 ± 0.07 for left-MRC, 0.17 ± 0.11 versus 0.18 ± 0.11 for right-MRC, 0.08 ± 0.04 versus 0.09 ± 0.04 for left-ARC, 0.09 ± 0.04 versus 0.09 ± 0.05 for right-ARC and 0.08 ± 0.04 versus 0.09 ± 0.03 for CARC and all ICC[3, 1] ≥ 0.77. Among these 5 approaches, the CARC provided the best intra-rater and inter-rater reliabilities with ICC [2, 1] ≥ 0.84 and SEM ≤ 0.01. CONCLUSIONS: The RC index could be measured repeatably and reliably. The high RC value may reduce the risk of progression of scoliosis.


Assuntos
Escoliose , Adolescente , Criança , Humanos , Vértebras Lombares/diagnóstico por imagem , Variações Dependentes do Observador , Projetos Piloto , Reprodutibilidade dos Testes , Escoliose/diagnóstico por imagem
5.
Biochim Biophys Acta Mol Cell Res ; 1868(6): 118996, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33675852

RESUMO

Calcium is a second messenger essential, in all cells, for most cell functions. The spatio-temporal control of changes in intracellular calcium concentration is partly due to the activation of calcium channels. Voltage-operated calcium channels are present in excitable and non-excitable cells. If the mechanism of voltage-operated calcium channels is well known in excitable cells the Ca2+ toolkit used in non-excitable cells to activate the calcium channels is less described. Herein we discuss about very similar pathways involving voltage activated Cav1 channels in two unrelated non-excitable cells; ectoderm cells undergoing neural development and effector Th2 lymphocytes responsible for parasite elimination and also allergic diseases. We will examine the way by which these channels operate and are regulated, as well as the consequences in terms of gene transcription. Finally, we will consider the questions that remain unsolved and how they might be a challenge for the future.


Assuntos
Canais de Cálcio Tipo L/metabolismo , Ectoderma/metabolismo , Células Th2/metabolismo , Xenopus laevis/crescimento & desenvolvimento , Animais , Cálcio/metabolismo , Canais de Cálcio Tipo L/genética , Sinalização do Cálcio , Ectoderma/crescimento & desenvolvimento , Regulação da Expressão Gênica no Desenvolvimento , Transcrição Gênica , Proteínas de Xenopus/genética , Proteínas de Xenopus/metabolismo , Xenopus laevis/metabolismo
6.
Med Sci (Paris) ; 36(11): 1018-1026, 2020 Nov.
Artigo em Francês | MEDLINE | ID: mdl-33151865

RESUMO

Neural induction is a developmental process that allows cells from the ectoderm (the target tissue) to acquire a neural fate in response to signals coming from a specific adjacent embryonic region, the dorsal mesoderm (the inducing tissue). This process described in 1924 in amphibian embryos has not received a molecular explanation until the mid-1990s. Most of the work on neural induction has been carried out in amphibians. At these times, although the role played by the membrane of the target tissue had been suggested, no definitive work had been performed on the transduction of the neuralizing signal. Between 1990 and 2019 our aim was to decipher this transduction. We have underlined the necessary and sufficient role played by calcium signaling to induce ectoderm cells towards a neural fate from the activation of calcium channels to the direct transcription of early neural genes by calcium.


TITLE: La saga de l'induction neurale : presque un siècle de recherche. ABSTRACT: La formation du système nerveux débute par l'induction neurale, un processus qui permet aux cellules de l'ectoderme (tissu cible) d'acquérir un destin neural en réponse à des signaux provenant du mésoderme dorsal (tissu inducteur). Ce processus, décrit en 1924 sur l'amphibien, n'a reçu une explication moléculaire qu'au milieu des années 1990. Pendant cette période, plusieurs auteurs se sont intéressés au rôle joué par la membrane du tissu cible mais peu de travaux décisifs ont décrit la transduction du signal neuralisant. Entre 1990 et 2019, nous avons disséqué la transduction du signal neuralisant, un sujet très peu abordé alors. Nous avons souligné le rôle nécessaire et suffisant du calcium pour orienter les cellules de l'ectoderme vers un destin neural et établi la cascade moléculaire allant de l'activation de canaux membranaires à la transcription de gènes.


Assuntos
Embriologia/história , Indução Embrionária/fisiologia , Sistema Nervoso/embriologia , Neurogênese/fisiologia , Anfíbios/embriologia , Anfíbios/metabolismo , Animais , Pesquisa Biomédica/história , Cálcio/metabolismo , Sinalização do Cálcio/fisiologia , Embrião não Mamífero , História do Século XIX , História do Século XX , História do Século XXI , Humanos
7.
Sci Rep ; 9(1): 16049, 2019 11 05.
Artigo em Inglês | MEDLINE | ID: mdl-31690785

RESUMO

In amphibians, the inhibition of bone morphogenetic protein (BMP) in the dorsal ectoderm has been proposed to be responsible for the first step of neural specification, called neural induction. We previously demonstrated that in Xenopus laevis embryos, the BMP signalling antagonist, noggin, triggers an influx of Ca2+ through voltage-dependent L-type Ca2+ channels (LTCCs), mainly via CaV1.2, and we showed that this influx constitutes a necessary and sufficient signal for triggering the expression of neural genes. However, the mechanism linking the inhibition of BMP signalling with the activation of LTCCs remained unknown. Here, we demonstrate that the transient receptor potential canonical subfamily member 1, (Trpc1), is an intermediate between BMP receptor type II (BMPRII) and the CaV1.2 channel. We show that noggin induces a physical interaction between BMPRII and Trpc1 channels. This interaction leads to the activation of Trpc1 channels and to an influx of cations, which depolarizes the plasma membrane up to a threshold sufficient to activate Cav1.2. Together, our results demonstrate for the first time that during neural induction, Ca2+ entry through the CaV1.2 channel results from the noggin-induced interaction between Trpc1 and BMPRII.


Assuntos
Proteínas Morfogenéticas Ósseas/metabolismo , Sinalização do Cálcio , Embrião não Mamífero/embriologia , Neurogênese , Canais de Cátion TRPC/metabolismo , Proteínas de Xenopus/metabolismo , Animais , Receptores de Proteínas Morfogenéticas Ósseas Tipo II/genética , Receptores de Proteínas Morfogenéticas Ósseas Tipo II/metabolismo , Proteínas Morfogenéticas Ósseas/genética , Membrana Celular/genética , Membrana Celular/metabolismo , Potenciais da Membrana , Canais de Cátion TRPC/genética , Proteínas de Xenopus/genética , Xenopus laevis
8.
BMC Musculoskelet Disord ; 20(1): 319, 2019 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-31286903

RESUMO

BACKGROUND: The Cobb angle is proposed as the "disease process" outcome for scoliosis research because therapies aim to correct or stop curve progression. While the Scoliosis Research Society recommends the Cobb angle as the primary outcome, the Society on Scoliosis Orthopaedic and Rehabilitation Treatment prioritises, as a general goal, patient related outcomes over Cobb angle progression. OBJECTIVE: To determine the threshold of change in the Cobb angle in adolescents with idiopathic scoliosis (AIS) who perceive improvement in a 6-months randomized controlled trial comparing a Schroth exercise intervention added to the standard of care to the standard of care alone. METHODS: This is a secondary analysis of data from a randomized controlled trial of 50 patients with AIS, with curves ranging from 10° to 45°, with or without a brace. Participants with diagnoses other than AIS, surgical candidates or patients who had scoliosis surgery were excluded. The 6-month interventions consisted of Schroth exercises added to standard-of-care (observation or bracing) with daily home exercises and weekly therapy sessions (Schroth) or standard-of-care alone (Control). The anchor method for estimating the minimal important difference (MID) in the largest Cobb angles (LC) was used. Patient-reported change in back status over the 6-month treatment period was measured using the Global Rating of Change (GRC) scale as anchor varying from - 7 ("great deal worse") to + 7 ("great deal better"). Participants were divided into two groups based on GRC scores: Improved (GRC ≥2) or Stable/Not Improved (GRC ≤1). MID was defined as the change in the LC that most accurately predicted the GRC classification as per the receiver operating characteristic curve (ROC). RESULTS: The average age was 13.4 ± 1.6 years and the average LC was 28.5 ± 8.8 °s. The average GRC in the control group was - 0.1 ± 1.6, compared to + 4.4 ± 2.2 in the Schroth group. The correlation between LC and GRC was adequate (r = - 0.34, p < 0.05). The MID for the LC was 1.0 °. The area under the ROC was 0.69 (0.52-0.86), suggesting a 70% chance to properly classify a patient as perceiving No Improvement/Stable or Improvement based on the change in the LC. CONCLUSION: Patients undergoing Schroth treatment perceived improved status of their backs even if the Cobb angle did not improve beyond the conventionally accepted threshold of 5°. Standard of care aims to slow/stop progression while Schroth exercises aim to improve postural balance, signs and symptoms of scoliosis. Given the very small MID, perceived improvement in back status is likely due to something other than the Cobb angle. This study warrants investigating alternatives to the Cobb angle that might be more relevant to patients. TRIAL REGISTRATION: ClinicalTrials.gov , NCT01610908 . Retrospectively registered on April 2, 2012 (first posted on June 4, 2012 - https://clinicaltrials.gov/ct2/keydates/NCT01610908 ).


Assuntos
Terapia por Exercício/métodos , Equilíbrio Postural/fisiologia , Escoliose/terapia , Adolescente , Criança , Progressão da Doença , Feminino , Humanos , Masculino , Escoliose/diagnóstico por imagem , Escoliose/fisiopatologia , Coluna Vertebral/diagnóstico por imagem , Coluna Vertebral/fisiopatologia , Padrão de Cuidado , Resultado do Tratamento
9.
Biochim Biophys Acta Mol Cell Res ; 1866(7): 1046-1053, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-30716407

RESUMO

This review aims at giving a rational frame to understand the diversity of EF hand containing calcium binding proteins and their roles, with special focus on three members of this huge protein family, namely calmodulin, troponin C and parvalbumin. We propose that these proteins are members of structured macromolecular complexes, termed calcisomes, which constitute building devices allowing treatment of information within eukaryotic cells and namely calcium signals encoding and decoding, as well as control of cytosolic calcium levels in resting cells. Calmodulin is ubiquitous, present in all eukaryotic cells, and pleiotropic. This may be explained by its prominent role in regulating calcium movement in and out of the cell, thus maintaining calcium homeostasis which is fundamental for cell survival. The protein is further involved in decoding transient calcium signals associated with calcium movements after cell stimulation. We will show that the specificity of calmodulin's actions may be more easily explained if one considers its role in the light of calcisomes. Parvalbumin should not be considered as a simple intracellular calcium buffer. It is also a key factor for regulating calcium homeostasis in specific cells that need a rapid retrocontrol of calcium transients, such as fast muscle fibers. Finally, we propose that troponin C, with its four calcium binding domains distributed between two lobes presenting different calcium binding kinetics, exhibits all the characteristics needed to trigger and then post modulate muscle contraction and thus appears as a typical Feed Forward Loop system. If the present conjectures prove accurate, the way will be paved for a new pharmacology targeting the cell calcium signaling machinery. This article is part of a Special Issue entitled: ECS Meeting edited by Claus Heizmann, Joachim Krebs and Jacques Haiech.


Assuntos
Sinalização do Cálcio/fisiologia , Cálcio/metabolismo , Calmodulina/metabolismo , Parvalbuminas/metabolismo , Troponina C/metabolismo , Animais , Humanos
10.
Sci Rep ; 8(1): 9731, 2018 06 27.
Artigo em Inglês | MEDLINE | ID: mdl-29950651

RESUMO

Quiescence is a reversible cell-cycle arrest which allows cancer stem-like cells to evade killing following therapies. Here, we show that proliferating glioblastoma stem-like cells (GSLCs) can be induced and maintained in a quiescent state by lowering the extracellular pH. Through RNAseq analysis we identified Ca2+ signalling genes differentially expressed between proliferating and quiescent GSLCs. Using the bioluminescent Ca2+ reporter EGFP-aequorin we observed that the changes in Ca2+ homeostasis occurring during the switch from proliferation to quiescence are controlled through store-operated channels (SOC) since inhibition of SOC drives proliferating GSLCs to quiescence. We showed that this switch is characterized by an increased capacity of GSLCs' mitochondria to capture Ca2+ and by a dramatic and reversible change of mitochondrial morphology from a tubular to a donut shape. Our data suggest that the remodelling of the Ca2+ homeostasis and the reshaping of mitochondria might favours quiescent GSLCs' survival and their aggressiveness in glioblastoma.


Assuntos
Sinalização do Cálcio/fisiologia , Glioblastoma/metabolismo , Mitocôndrias/metabolismo , Células-Tronco Neoplásicas/citologia , Adulto , Apoptose/fisiologia , Divisão Celular/fisiologia , Linhagem Celular Tumoral , Proliferação de Células/fisiologia , Sobrevivência Celular/fisiologia , Humanos , Transdução de Sinais/fisiologia , Adulto Jovem
11.
Sci China Life Sci ; 61(11): 1352-1368, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-29931586

RESUMO

The development of the CNS in vertebrate embryos involves the generation of different sub-types of neurons and glia in a complex but highly-ordered spatio-temporal manner. Zebrafish are commonly used for exploring the development, plasticity and regeneration of the CNS, and the recent development of reliable protocols for isolating and culturing neural stem/progenitor cells (NSCs/NPCs) from the brain of adult fish now enables the exploration of mechanisms underlying the induction/specification/differentiation of these cells. Here, we refined a protocol to generate proliferating and differentiating neurospheres from the entire brain of adult zebrafish. We demonstrated via RT-qPCR that some isoforms of ip3r, ryr and stim are upregulated/downregulated significantly in differentiating neurospheres, and via immunolabelling that 1,4,5-inositol trisphosphate receptor (IP3R) type-1 and ryanodine receptor (RyR) type-2 are differentially expressed in cells with neuron- or radial glial-like properties. Furthermore, ATP but not caffeine (IP3R and RyR agonists, respectively), induced the generation of Ca2+ transients in cells exhibiting neuron- or glial-like morphology. These results indicate the differential expression of components of the Ca2+-signaling toolkit in proliferating and differentiating cells. Thus, given the complexity of the intact vertebrate brain, neurospheres might be a useful system for exploring neurodegenerative disease diagnosis protocols and drug development using Ca2+ signaling as a read-out.


Assuntos
Sinalização do Cálcio/fisiologia , Diferenciação Celular/fisiologia , Células-Tronco Neurais/citologia , Células-Tronco Neurais/fisiologia , Neuroglia/citologia , Neurônios/citologia , Animais , Células Cultivadas , Regulação da Expressão Gênica no Desenvolvimento , Doenças Neurodegenerativas/fisiopatologia , Transdução de Sinais , Peixe-Zebra
12.
PLoS One ; 13(6): e0198792, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29912905

RESUMO

The measurements of spinal curvatures using the ultrasound (US) imaging method on children with scoliosis have been comparable with radiography. However, factors influencing the reliability and accuracy of US measurement have not been studied. The purpose of this study is to investigate the effects of curve features and patients' demographics on US measurements and to determine which factors influence the reliability and accuracy. Two hundred children with scoliosis were recruited and scanned with US by one experienced operator and three trainees. One experienced rater measured the proxy Cobb angles from US images twice one week apart and compared the results with clinical radiographic records. The correlation and accuracy between the US and radiographic measurements were subdivided by different curve severities, curve types, subjects' weight status and US acquisition experiences. A total of 326 and 313 curves were recognized from radiographs and US images, respectively. The mean Cobb angles of the 13 missing curves were 17.4±7.4° and 11 at the thoracic region. Among the 16 curves showing large discrepancy (≥6°) between US and radiographic measurements, 7 were main thoracic and 6 were lumbar curves. Twelve had axial vertebral rotation (AVR) greater than 8°. The US scans performed by the experienced operator showed fewer large discrepancy curves, smaller difference and higher correlation than the scans from the trainees (3%, 1.7±1.5°, 0.95 vs 6%, 2.4±1.8°, 0.90). Only 4% missing and 5% large discrepancy curves were demonstrated for US measurements in comparison to radiography. The missing curves were mainly caused by small severity and in the upper spinal region. There was a higher chance of the large discrepancy curves in the main thoracic and lumbar regions with AVR>8°. A skilled operator acquired better US images and led to more accurate measurements especially for those subjects with larger curvatures, AVR and body mass index (BMI).


Assuntos
Escoliose/diagnóstico por imagem , Coluna Vertebral/diagnóstico por imagem , Ultrassonografia , Adolescente , Feminino , Humanos , Vértebras Lombares/diagnóstico por imagem , Masculino , Radiografia , Reprodutibilidade dos Testes , Vértebras Torácicas/diagnóstico por imagem
13.
Sci China Life Sci ; 61(3): 253-265, 2018 03.
Artigo em Inglês | MEDLINE | ID: mdl-29392682

RESUMO

Transient receptor potential canonical subfamily member 3 (TRPC3) is known to be important for neural development and the formation of neuronal networks. Here, we investigated the role of TRPC3 in undifferentiated mouse embryonic stem cells (mESCs) and during the differentiation of mESCs into neurons. CRISPR/Cas9-mediated knockout (KO) of TRPC3 induced apoptosis and the disruption of mitochondrial membrane potential both in undifferentiated mESCs and in those undergoing neural differentiation. In addition, TRPC3 KO impaired the pluripotency of mESCs. TRPC3 KO also dramatically repressed the neural differentiation of mESCs by inhibiting the expression of markers for neural progenitors, neurons, astrocytes and oligodendrocytes. Taken together, our new data demonstrate an important function of TRPC3 with regards to the survival, pluripotency and neural differentiation of mESCs.


Assuntos
Diferenciação Celular/fisiologia , Sobrevivência Celular/fisiologia , Células-Tronco Embrionárias Murinas/citologia , Células-Tronco Pluripotentes/citologia , Canais de Cátion TRPC/fisiologia , Animais , Apoptose , Linhagem Celular , Técnicas de Inativação de Genes , Potencial da Membrana Mitocondrial , Camundongos , Neurogênese , Neuroglia/citologia , Neurônios/citologia , Canais de Cátion TRPC/genética
14.
Eur Spine J ; 27(9): 2114-2119, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-29322312

RESUMO

PURPOSE: To investigate the threshold of the curve difference on ultrasound measurement relative to the previous radiographic measurements to detect curves progression in children who have idiopathic scoliosis (IS). METHODS: Two hundred children with IS (F:170, M:30; mean age: 14.6 ± 1.9) were recruited from a single center. A retrospective study on comparing the current ultrasound measurements with the previous radiographic measurements with threshold values from 3° to 8° to detect curve progression was conducted. The receiver operating characteristic (ROC) analysis, accuracy (ACC), and odd ratio (OR) were calculated to determine the optimal threshold value of the curve differences between ultrasound and previous radiographic measurement. RESULTS: Both thresholds of 4° and 5° for curve difference from ultrasound scans presented the sensitivities ≥ 0.90 and specificities ≥ 0.85, and can reduce by 73 and 79% of radiographs on the studied subjects, respectively. Especially, for 4° threshold, the negative likelihood ratio (LR-) was only 0.08, which indicated that there is only 8% probability that the subject has progressed if the US measurement detected non-progression. CONCLUSIONS: The ultrasound imaging method can be applied to identify curve progression in children with IS. Four degree is the preferred threshold value to detect the curve which had progressed, since it also had the lower rate of undetected progressed cases (false negatives).


Assuntos
Escoliose/diagnóstico por imagem , Coluna Vertebral/diagnóstico por imagem , Adolescente , Criança , Progressão da Doença , Feminino , Humanos , Masculino , Radiografia , Reprodutibilidade dos Testes , Estudos Retrospectivos , Escoliose/patologia , Sensibilidade e Especificidade , Ultrassonografia
15.
Front Mol Neurosci ; 11: 472, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30618619

RESUMO

Glioblastomas (GBMs) are the most aggressive and lethal primary astrocytic tumors in adults, with very poor prognosis. Recurrence in GBM is attributed to glioblastoma stem-like cells (GSLCs). The behavior of the tumor, including proliferation, progression, invasion, and significant resistance to therapies, is a consequence of the self-renewing properties of the GSLCs, and their high resistance to chemotherapies have been attributed to their capacity to enter quiescence. Thus, targeting GSLCs may constitute one of the possible therapeutic challenges to significantly improve anti-cancer treatment regimens for GBM. Ca2+ signaling is an important regulator of tumorigenesis in GBM, and the transition from proliferation to quiescence involves the modification of the kinetics of Ca2+ influx through store-operated channels due to an increased capacity of the mitochondria of quiescent GSLC to capture Ca2+. Therefore, the identification of new therapeutic targets requires the analysis of the calcium-regulated elements at transcriptional levels. In this review, we focus onto the direct regulation of gene expression by KCNIP proteins (KCNIP1-4). These proteins constitute the class E of Ca2+ sensor family with four EF-hand Ca2+-binding motifs and control gene transcription directly by binding, via a Ca2+-dependent mechanism, to specific DNA sites on target genes, called downstream regulatory element (DRE). The presence of putative DRE sites on genes associated with unfavorable outcome for GBM patients suggests that KCNIP proteins may contribute to the alteration of the expression of these prognosis genes. Indeed, in GBM, KCNIP2 expression appears to be significantly linked to the overall survival of patients. In this review, we summarize the current knowledge regarding the quiescent GSLCs with respect to Ca2+ signaling and discuss how Ca2+ via KCNIP proteins may affect prognosis genes expression in GBM. This original mechanism may constitute the basis of the development of new therapeutic strategies.

16.
Artigo em Inglês | MEDLINE | ID: mdl-29164179

RESUMO

BACKGROUND: Recent randomized controlled trials (RCTs) support using physiotherapeutic scoliosis-specific exercises (PSSE) for adolescents with idiopathic scoliosis (AIS). All RCTs reported statistically significant results favouring PSSE but none reported on clinical significance. The number needed to treat (NNT) helps determine if RCT results are clinically meaningful. The NNT is the number of patients that need to be treated to prevent one bad outcome in a given period. A low NNT suggests that a therapy has positive outcomes in most patients offered the therapy. The objective was to determine how many patients require Schroth PSSE added to standard care (observation or brace treatment) to prevent one progression (NNT) of the Largest Curve (LC) or Sum of Curves (SOC) beyond 5° and 10°, respectively over a 6-month interval. METHODS: This was a secondary analysis of a RCT. Fifty consecutive participants from a scoliosis clinic were randomized to the Schroth PSSE + standard of care group (n = 25) or the standard of care group (n = 25).We included males and females with AIS, age 10-18 years, all curve types, with curves 10°- 45°, with or without brace, and all maturity levels. We excluded patients awaiting surgery, having had surgery, having completed brace treatment and with other scoliosis diagnoses. The local ethics review board approved the study (Pro00011552).The Schroth intervention consisted of weekly 1-h supervised Schroth PSSE sessions and a daily home program delivered over six months in addition to the standard of care. A prescription algorithm was used to determine which exercises patients were to perform. Controls received only standard of care.Cobb angles were measured using a semi-automatic system from posterior-anterior standing radiographs at baseline and 6 months.We calculated absolute risk reduction (ARR) and relative risk reduction (RRR). The NTT was calculated as: NNT = 1/ARR. Patients with missing values (PSSE group; n = 2 and controls; n = 4) were assumed to have had curve progression (worst case scenario). The RRR is calculated as RRR = ARR/CER. RESULTS: For LC, NNT = 3.6 (95% CI 2.0-28.2), and for SOC, NNT = 3.1 (95% CI 1.9-14.2). The corresponding ARR was 28% for LC and 32% for the SOC. The RRR was 70% for LC and 73% for the SOC. Patients with complete follow-up attended 85% of prescribed visits and completed 82.5% of the home program. Assuming zero compliance after dropout, 76% of visits were attended and 73% of the prescribed home exercises were completed. CONCLUSIONS: The short term of Schroth PSSE intervention added to standard care provided a large benefit as compared to standard care alone. Four (LC and SOC) patients require treatment for the additional benefit of a 6-month long Schroth intervention to be observed beyond the standard of care in at least one patient. TRIAL REGISTRATION: NCT01610908 April 2, 2012.

17.
Artigo em Inglês | MEDLINE | ID: mdl-28795156

RESUMO

BACKGROUND: Four factors have been reported to affect brace treatment outcome: (1) growth or curve based risk, (2) the in-brace correction, (3) the brace wear quantity, and (4) the brace wear quality. The quality of brace design affects the in-brace correction and comfort which indirectly affects the brace wear quantity and quality. This paper reported the immediate benefits and results on using ultrasound (US) to aid orthotists to design braces for the treatment of scoliosis. METHODS: Thirty-four AIS subjects participated in this study with 17 (2 males, 15 females) in the control group and 17 (2 males, 15 females) in the intervention (US) group. All participants were prescribed full time TLSO, constructed by either of the 2 orthotists in fabrication of spinal braces. For the control group, the Providence brace design system was adopted to design full time braces. For the intervention group, the custom standing Providence brace design system, plus a medical ultrasound system, a custom pressure measurement system and an in-house software were used to assist brace casting. RESULTS: In the control group, 8 of 17 (47%) subjects needed a total of 11 brace adjustments after initial fabrication requiring a total of 28 in-brace radiographs. Three subjects (18%) required a second adjustment. For the US group, only 1 subject (6%) required adjustment. The total number of in-brace radiographs was 18. The p value of the chi-square for requiring brace adjustment was 0.006 which was a statistically significant difference between the two groups. In the intervention group, the immediate in-brace correction as measured from radiographs was 48 ± 17%, and in the control group the first and second in-brace correction was 33 ± 19% and 40 ± 20%, respectively. The unpaired 2 sided Student's t test of the in-brace correction was significantly different between the US and the first follow-up of the control group (p = 0.02), but was not significant after the second brace adjustment (p = 0.22). CONCLUSIONS: The use of the 3D ultrasound system provided a radiation-free method to determine the optimum pressure level and location to assist brace design, resulting in decreased radiation exposure during follow-up brace evaluation, increased the in-brace correction, reduced the patients' visits to both brace adjustment and scoliosis clinics. However, the final outcomes could not be reported yet as some of patients are still under brace treatment. TRIAL REGISTRATION: NCT02996643, retrospectively registered in 16 December 2016.

18.
Ultrasound Med Biol ; 43(5): 934-942, 2017 05.
Artigo em Inglês | MEDLINE | ID: mdl-28274602

RESUMO

The ultrasound imaging method was implemented to assess the spinal curve flexibility of scoliotic surgical candidates, or how much correction it can achieve while patients are bending or lying down. Fifteen participants were recruited. Pre-operative radiographs and ultrasound images in both standing and bending positions were acquired. The post-operative standing radiographs were obtained 1 wk after surgery. Two raters (RZ, EL) measured the ultrasound images twice, 1 wk apart. A curve correction index (CI) was developed to estimate the curve flexibility. The CI from the pre-operative bending radiograph, ultrasound and post-operative radiograph were 0.51 ± 0.18; R1: 0.74 ± 0.08 vs R2: 0.72 ± 0.09 and 0.60 ± 0.10, respectively. The correlation of CI between ultrasound and post-operative radiography was slightly higher than the pre-operative bending and post-operative radiography. This pilot study demonstrated the bending ultrasound method is a promising supplemental tool to assess curve flexibility before surgical intervention for scoliotic surgical candidates.


Assuntos
Escoliose/diagnóstico por imagem , Escoliose/cirurgia , Ultrassonografia/métodos , Adolescente , Criança , Feminino , Humanos , Masculino , Projetos Piloto , Postura , Reprodutibilidade dos Testes , Coluna Vertebral/diagnóstico por imagem , Coluna Vertebral/cirurgia
19.
Biochim Biophys Acta Mol Cell Res ; 1864(6): 1018-1027, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28109792

RESUMO

Glioblastoma is the most common malignant brain tumor. The heterogeneity at the cellular level, metabolic specificities and plasticity of the cancer cells are a challenge for glioblastoma treatment. Identification of cancer cells endowed with stem properties and able to propagate the tumor in animal xenografts has opened a new paradigm in cancer therapy. Thus, to increase efficacy and avoid tumor recurrence, therapies need to target not only the differentiated cells of the tumor mass, but also the cancer stem-like cells. These therapies need to be effective on cells present in the hypoxic, slightly acidic microenvironment found within tumors. Such a microenvironment is known to favor more aggressive undifferentiated phenotypes and a slow-growing "quiescent state" that preserves the cells from chemotherapeutic agents, which mostly target proliferating cells. Based on these considerations, we performed a differential screening of the Prestwick Chemical Library of approved drugs on both proliferating and quiescent glioblastoma stem-like cells and identified bisacodyl as a cytotoxic agent with selectivity for quiescent glioblastoma stem-like cells. In the present study we further characterize bisacodyl activity and show its efficacy in vitro on clonal macro-tumorospheres, as well as in vivo in glioblastoma mouse models. Our work further suggests that bisacodyl acts through inhibition of Ca2+ release from the InsP3 receptors.


Assuntos
Bisacodil/farmacologia , Neoplasias Encefálicas/patologia , Sinalização do Cálcio , Glioblastoma/patologia , Receptores de Inositol 1,4,5-Trifosfato/metabolismo , Células-Tronco Neoplásicas/patologia , Neoplasias Encefálicas/metabolismo , Linhagem Celular Tumoral , Glioblastoma/metabolismo , Humanos , Células-Tronco Neoplásicas/metabolismo
20.
Spine (Phila Pa 1976) ; 42(13): E781-E787, 2017 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-27811503

RESUMO

STUDY DESIGN: A validation study. OBJECTIVE: The aim of this study was to independently validate the diagnostic accuracy of surface topography (ST) classification trees to identify curve severity and progression using a new sample of data in participants with adolescent idiopathic scoliosis (AIS). SUMMARY OF BACKGROUND DATA: Radiographs for diagnosing and monitoring AIS involve harmful radiation exposure repeated at successive clinical visits. Classification trees using a novel ST technique have been proposed to determine curve severity and progression noninvasively that could be used to monitor scoliosis. METHODS: Forty-five adolescents with AIS treated nonoperatively, with ST scans and radiographs at baseline and follow-up (1 year later), were recruited from a scoliosis clinic. The Cobb angle (CA) from radiographs determined curve severity as mild (10° < CA < 25°) or moderate/severe (CA ≥ 25°) and progression as an increase >5°.ST scans were analyzed to calculate the best plane of symmetry and associated deviation color map. Root mean squares and maximum deviation were calculated for each area of asymmetry. ST measurements were analyzed using two published decision trees developed to maximize sensitivity and negative predictive value. Curves were classified as mild or moderate/severe and curve progression was predicted. Accuracy statistics were calculated to evaluate performance. RESULTS: For curve severity, sensitivity and specificity were 95% and 35%, respectively. Negative and positive predictive values were 90% and 53%, respectively, with an accuracy of 61%. For curve progression, sensitivity and specificity were 73% and 44%, respectively. Negative and positive predictive values were 83% and 30%, respectively, with an accuracy of 51%. Assuming that mild and nonprogressive curves would not require an x-ray, the use of ST decision trees could eliminate 31% of x-rays. CONCLUSION: Decision trees showed strong negative predictive values and sensitivity suggesting it may be possible to safely use ST asymmetry analysis with validated decision trees to reduce x-rays in patients with mild and nonprogressive curves. LEVEL OF EVIDENCE: 2.


Assuntos
Árvores de Decisões , Progressão da Doença , Escoliose/classificação , Escoliose/diagnóstico por imagem , Índice de Gravidade de Doença , Adolescente , Criança , Feminino , Humanos , Masculino
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