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1.
EMBO Mol Med ; 16(8): 1840-1885, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-39009887

RESUMO

We have recently identified the uncharacterized ZNF555 protein as a component of a productive complex involved in the morbid function of the 4qA locus in facioscapulohumeral dystrophy. Subsequently named DiPRO1 (Death, Differentiation, and PROliferation related PROtein 1), our study provides substantial evidence of its role in the differentiation and proliferation of human myoblasts. DiPRO1 operates through the regulatory binding regions of SIX1, a master regulator of myogenesis. Its relevance extends to mesenchymal tumors, such as rhabdomyosarcoma (RMS) and Ewing sarcoma, where DiPRO1 acts as a repressor via the epigenetic regulators TIF1B and UHRF1, maintaining methylation of cis-regulatory elements and gene promoters. Loss of DiPRO1 mimics the host defense response to virus, awakening retrotransposable repeats and the ZNF/KZFP gene family. This enables the eradication of cancer cells, reprogramming the cellular decision balance towards inflammation and/or apoptosis by controlling TNF-α via NF-kappaB signaling. Finally, our results highlight the vulnerability of mesenchymal cancer tumors to si/shDiPRO1-based nanomedicines, positioning DiPRO1 as a potential therapeutic target.


Assuntos
Diferenciação Celular , Humanos , Proliferação de Células , Mioblastos/metabolismo
2.
Cells ; 12(23)2023 11 21.
Artigo em Inglês | MEDLINE | ID: mdl-38067102

RESUMO

Satellite cells (SCs) are adult muscle stem cells that are mobilized when muscle homeostasis is perturbed. Here we show that RhoA in SCs is indispensable to have correct muscle regeneration and hypertrophy. In particular, the absence of RhoA in SCs prevents a correct SC fusion both to other RhoA-deleted SCs (regeneration context) and to growing control myofibers (hypertrophy context). We demonstrated that RhoA is dispensable for SCs proliferation and differentiation; however, RhoA-deleted SCs have an inefficient movement even if their cytoskeleton assembly is not altered. Proliferative myoblast and differentiated myotubes without RhoA display a decreased expression of Chordin, suggesting a crosstalk between these genes for myoblast fusion regulation. These findings demonstrate the importance of RhoA in SC fusion regulation and its requirement to achieve an efficient skeletal muscle homeostasis restoration.


Assuntos
Fusão Celular , Fibras Musculares Esqueléticas , Células Satélites de Músculo Esquelético , Proteína rhoA de Ligação ao GTP , Humanos , Comunicação Celular , Hipertrofia/metabolismo , Células Satélites de Músculo Esquelético/fisiologia , Proteína rhoA de Ligação ao GTP/genética , Proteína rhoA de Ligação ao GTP/fisiologia
3.
PLoS Genet ; 19(6): e1010781, 2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-37267426

RESUMO

Four SIX homeoproteins display a combinatorial expression throughout embryonic developmental myogenesis and they modulate the expression of the myogenic regulatory factors. Here, we provide a deep characterization of their role in distinct mouse developmental territories. We showed, at the hypaxial level, that the Six1:Six4 double knockout (dKO) somitic precursor cells adopt a smooth muscle fate and lose their myogenic identity. At the epaxial level, we demonstrated by the analysis of Six quadruple KO (qKO) embryos, that SIX are required for fetal myogenesis, and for the maintenance of PAX7+ progenitor cells, which differentiated prematurely and are lost by the end of fetal development in qKO embryos. Finally, we showed that Six1 and Six2 are required to establish craniofacial myogenesis by controlling the expression of Myf5. We have thus described an unknown role for SIX proteins in the control of myogenesis at different embryonic levels and refined their involvement in the genetic cascades operating at the head level and in the genesis of myogenic stem cells.


Assuntos
Proteínas de Homeodomínio , Somitos , Camundongos , Animais , Proteínas de Homeodomínio/metabolismo , Diferenciação Celular/genética , Somitos/metabolismo , Desenvolvimento Muscular/genética , Regulação da Expressão Gênica no Desenvolvimento , Músculo Esquelético/metabolismo
4.
Development ; 150(9)2023 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-37017267

RESUMO

Developmental senescence is a form of programmed senescence that contributes to morphogenesis during embryonic development. We showed recently that the SIX1 homeoprotein, an essential regulator of organogenesis, is also a repressor of adult cellular senescence. Alterations in the SIX/EYA pathway are linked to the human branchio-oto-renal (BOR) syndrome, a rare congenital disorder associated with defects in the ears, kidneys and branchial arches. Here, we have used Six1-deficient mice, an animal model of the BOR syndrome, to investigate whether dysfunction of senescence underpins the developmental defects associated with SIX1 deficiency. We have focused on the developing inner ear, an organ with physiological developmental senescence that is severely affected in Six1-deficient mice and BOR patients. We show aberrant levels and distribution of senescence markers in Six1-deficient inner ears concomitant with defective morphogenesis of senescent structures. Transcriptomic analysis and ex vivo assays support a link between aberrant senescence and altered morphogenesis in this model, associated with deregulation of the TGFß/BMP pathway. Our results show that misregulation of embryo senescence may lead to genetic developmental disorders, significantly expanding the connection between senescence and disease.


Assuntos
Síndrome Brânquio-Otorrenal , Orelha Interna , Adulto , Humanos , Camundongos , Animais , Proteínas Tirosina Fosfatases/fisiologia , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Proteínas Nucleares/genética , Síndrome Brânquio-Otorrenal/genética , Proteínas de Homeodomínio/metabolismo
5.
Ther Drug Monit ; 45(5): 637-643, 2023 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-36750447

RESUMO

PURPOSE: Vancomycin dosing remains challenging in patients receiving intermittent hemodialysis, especially in developing countries, where access to therapeutic drug monitoring and model-based dose adjustment services is limited. The objectives of this study were to describe vancomycin population PK in patients receiving hemodialysis in a Malian and French center and examine the optimal loading dose of vancomycin in this setting. METHODS: Population pharmacokinetic analysis was conducted using Pmetrics in 31 Malian and 27 French hemodialysis patients, having a total of 309 vancomycin plasma concentrations. Structural and covariate analyses were based on goodness-of-fit criteria. The final model was used to perform simulations of the vancomycin loading dose, targeting a daily area under the concentration-time curve (AUC) of 400-600 mg.h/L or trough concentration of 15-20 mg/L at 48 hours. RESULTS: After 48 hours of therapy, 68% of Malian and 63% of French patients exhibited a daily AUC of <400. The final model was a 2-compartment model, with hemodialysis influencing vancomycin elimination and age influencing the vancomycin volume distribution. Younger Malian patients exhibited a lower distribution volume than French patients. Dosing simulation suggested that loading doses of 1500, 2000, and 2500 mg would be required to minimize underexposure in patients aged 30, 50, and 70 years, respectively. CONCLUSIONS: In this study, a low AUC was frequently observed in hemodialysis patients in Mali and France after a standard vancomycin loading dose. A larger dose is necessary to achieve the currently recommended AUC target. However, the proposed dosing algorithm requires further clinical evaluation.


Assuntos
Antibacterianos , Vancomicina , Humanos , Vancomicina/farmacocinética , Antibacterianos/farmacocinética , Diálise Renal , Simulação por Computador , Monitoramento de Medicamentos , Área Sob a Curva
6.
JCI Insight ; 7(10)2022 05 23.
Artigo em Inglês | MEDLINE | ID: mdl-35420997

RESUMO

Idiopathic pulmonary fibrosis (IPF) is a fatal disease with limited treatment options. The role of the developmental transcription factor Sine oculis homeobox homolog 1 (SIX1) in the pathophysiology of lung fibrosis is not known. IPF lung tissue samples and IPF-derived alveolar type II cells (AT2) showed a significant increase in SIX1 mRNA and protein levels, and the SIX1 transcriptional coactivators EYA1 and EYA2 were elevated. Six1 was also upregulated in bleomycin-treated (BLM-treated) mice and in a model of spontaneous lung fibrosis driven by deletion of Telomeric Repeat Binding Factor 1 (Trf1) in AT2 cells. Conditional deletion of Six1 in AT2 cells prevented or halted BLM-induced lung fibrosis, as measured by a significant reduction in histological burden of fibrosis, reduced fibrotic mediator expression, and improved lung function. These effects were associated with increased macrophage migration inhibitory factor (MIF) in lung epithelial cells in vivo following SIX1 overexpression in BLM-induced fibrosis. A MIF promoter-driven luciferase assay demonstrated direct binding of Six1 to the 5'-TCAGG-3' consensus sequence of the MIF promoter, identifying a likely mechanism of SIX1-driven MIF expression in the pathogenesis of lung fibrosis and providing a potentially novel pathway for targeting in IPF therapy.


Assuntos
Proteínas de Homeodomínio , Fibrose Pulmonar Idiopática , Animais , Fibrose , Genes Homeobox , Proteínas de Homeodomínio/genética , Proteínas de Homeodomínio/metabolismo , Fibrose Pulmonar Idiopática/induzido quimicamente , Fibrose Pulmonar Idiopática/genética , Camundongos , Fatores de Transcrição/genética
7.
Nat Commun ; 13(1): 1039, 2022 02 24.
Artigo em Inglês | MEDLINE | ID: mdl-35210422

RESUMO

The contractile properties of adult myofibers are shaped by their Myosin heavy chain isoform content. Here, we identify by snATAC-seq a 42 kb super-enhancer at the locus regrouping the fast Myosin genes. By 4C-seq we show that active fast Myosin promoters interact with this super-enhancer by DNA looping, leading to the activation of a single promoter per nucleus. A rainbow mouse transgenic model of the locus including the super-enhancer recapitulates the endogenous spatio-temporal expression of adult fast Myosin genes. In situ deletion of the super-enhancer by CRISPR/Cas9 editing demonstrates its major role in the control of associated fast Myosin genes, and deletion of two fast Myosin genes at the locus reveals an active competition of the promoters for the shared super-enhancer. Last, by disrupting the organization of fast Myosin, we uncover positional heterogeneity within limb skeletal muscles that may underlie selective muscle susceptibility to damage in certain myopathies.


Assuntos
Fibras Musculares Esqueléticas , Miosinas , Animais , Camundongos , Camundongos Transgênicos , Fibras Musculares Esqueléticas/metabolismo , Músculo Esquelético/metabolismo , Cadeias Pesadas de Miosina/genética , Cadeias Pesadas de Miosina/metabolismo , Miosinas/genética , Miosinas/metabolismo , Fenótipo
8.
iScience ; 25(1): 103616, 2022 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-35106464

RESUMO

Adult skeletal muscle is a plastic tissue that can adapt its size to workload. Here, we show that RhoA within myofibers is needed for overload-induced hypertrophy by controlling satellite cell (SC) fusion to the growing myofibers without affecting protein synthesis. At the molecular level, we demonstrate that RhoA controls in a cell autonomous manner Erk1/2 activation and the expressions of extracellular matrix (ECM) regulators such as Mmp9/Mmp13/Adam8 and macrophage chemo-attractants such as Ccl3/Cx3cl1. Their decreased expression in RhoA mutants is associated with ECM and fibrillar collagen disorganization and lower macrophage infiltration. Moreover, matrix metalloproteinases inhibition and macrophage depletion in controls phenocopied the altered growth of RhoA mutants while having no effect in mutants showing that their action is RhoA-dependent. These findings unravel the implication of RhoA within myofibers, in the building of a permissive microenvironment for muscle hypertrophic growth and for SC accretion through ECM remodeling and inflammatory cell recruitment.

9.
J Med Genet ; 59(2): 165-169, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-33436522

RESUMO

BACKGROUND: Pathogenic heterozygous SIX1 variants (predominantly missense) occur in branchio-otic syndrome (BOS), but an association with craniosynostosis has not been reported. METHODS: We investigated probands with craniosynostosis of unknown cause using whole exome/genome (n=628) or RNA (n=386) sequencing, and performed targeted resequencing of SIX1 in 615 additional patients. Expression of SIX1 protein in embryonic cranial sutures was examined in the Six1nLacZ/+ reporter mouse. RESULTS: From 1629 unrelated cases with craniosynostosis we identified seven different SIX1 variants (three missense, including two de novo mutations, and four nonsense, one of which was also present in an affected twin). Compared with population data, enrichment of SIX1 loss-of-function variants was highly significant (p=0.00003). All individuals with craniosynostosis had sagittal suture fusion; additionally four had bilambdoid synostosis. Associated BOS features were often attenuated; some carrier relatives appeared non-penetrant. SIX1 is expressed in a layer basal to the calvaria, likely corresponding to the dura mater, and in the mid-sagittal mesenchyme. CONCLUSION: Craniosynostosis is associated with heterozygous SIX1 variants, with possible enrichment of loss-of-function variants compared with classical BOS. We recommend screening of SIX1 in craniosynostosis, particularly when sagittal±lambdoid synostosis and/or any BOS phenotypes are present. These findings highlight the role of SIX1 in cranial suture homeostasis.


Assuntos
Craniossinostoses/genética , Proteínas de Homeodomínio/genética , Animais , Pré-Escolar , Estudos de Coortes , Suturas Cranianas/embriologia , Suturas Cranianas/patologia , Craniossinostoses/complicações , Craniossinostoses/embriologia , Análise Mutacional de DNA , Estudos de Associação Genética , Proteínas de Homeodomínio/fisiologia , Humanos , Lactente , Camundongos , Linhagem , Fenótipo , RNA-Seq , Sequenciamento Completo do Genoma
10.
STAR Protoc ; 2(3): 100694, 2021 09 17.
Artigo em Inglês | MEDLINE | ID: mdl-34382019

RESUMO

Single-nucleus RNA sequencing allows the profiling of gene expression in isolated nuclei. Here, we describe a step-by-step protocol optimized for adult mouse skeletal muscles. This protocol provides two main advantages compared to the widely used single-cell protocol. First, it allows us to sequence the myonuclei of the multinucleated myofibers. Second, it circumvents the cell-dissociation-induced transcriptional modifications. For complete details on the use and execution of this protocol, please refer to Dos Santos et al. (2020) and Machado, Geara et al. (2021).


Assuntos
Núcleo Celular/genética , Análise de Sequência de RNA/métodos , Análise de Célula Única/métodos , Animais , Técnicas de Cultura de Células/métodos , Separação Celular/métodos , Camundongos , Fibras Musculares Esqueléticas/metabolismo , Músculo Esquelético/citologia , RNA/química , RNA/isolamento & purificação , Células Satélites de Músculo Esquelético/metabolismo
11.
Ther Drug Monit ; 43(4): 461-471, 2021 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-34250963

RESUMO

ABSTRACT: Using pharmacokinetic (PK) models and Bayesian methods in dosing software facilitates the analysis of individual PK data and precision dosing. Several Bayesian methods are available for computing Bayesian posterior distributions using nonparametric population models. The objective of this study was to compare the performance of the maximum a posteriori (MAP) model, multiple model (MM), interacting MM (IMM), and novel hybrid MM(HMM) in estimating past concentrations and predicting future concentrations during therapy. Amikacin and vancomycin PK data were analyzed in older hospitalized patients using 2 strategies. First, the entire data set of each patient was fitted using each of the 4 methods implemented in BestDose software. Then, the 4 methods were used in each therapeutic drug monitoring occasion to estimate the past concentrations available at this time and to predict the subsequent concentrations to be observed on the next occasion. The bias and precision of the model predictions were compared among the methods. A total of 406 amikacin concentrations from 96 patients and 718 vancomycin concentrations from 133 patients were available for analysis. Overall, significant differences were observed in the predictive performance of the 4 Bayesian methods. The IMM method showed the best fit to past concentration data of amikacin and vancomycin, whereas the MM method was the least precise. However, MM best predicted the future concentrations of amikacin. The MAP and HMM methods showed a similar predictive performance and seemed to be more appropriate for the prediction of future vancomycin concentrations than the other models were. The richness of the prior distribution may explain the discrepancies between the results of the 2 drugs. Although further research with other drugs and models is necessary to confirm our findings, these results challenge the widely accepted assumption in PK modeling that a better data fit indicates better forecasting of future observations.


Assuntos
Amicacina , Teorema de Bayes , Monitoramento de Medicamentos/métodos , Vancomicina , Idoso , Amicacina/farmacocinética , Humanos , Software , Vancomicina/farmacocinética
12.
Mol Metab ; 51: 101228, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-33798773

RESUMO

OBJECTIVE: The metabolic master-switch AMP-activated protein kinase (AMPK) mediates insulin-independent glucose uptake in muscle and regulates the metabolic activity of brown and beige adipose tissue (BAT). The regulatory AMPKγ3 isoform is uniquely expressed in skeletal muscle and potentially in BAT. Herein, we investigated the role that AMPKγ3 plays in mediating skeletal muscle glucose uptake and whole-body glucose clearance in response to small-molecule activators that act on AMPK via distinct mechanisms. We also assessed whether γ3 plays a role in adipose thermogenesis and browning. METHODS: Global AMPKγ3 knockout (KO) mice were generated. A systematic whole-body, tissue, and molecular phenotyping linked to glucose homeostasis was performed in γ3 KO and wild-type (WT) mice. Glucose uptake in glycolytic and oxidative skeletal muscle ex vivo as well as blood glucose clearance in response to small molecule AMPK activators that target the nucleotide-binding domain of the γ subunit (AICAR) and allosteric drug and metabolite (ADaM) site located at the interface of the α and ß subunit (991, MK-8722) were assessed. Oxygen consumption, thermography, and molecular phenotyping with a ß3-adrenergic receptor agonist (CL-316,243) treatment were performed to assess BAT thermogenesis, characteristics, and function. RESULTS: Genetic ablation of γ3 did not affect body weight, body composition, physical activity, and parameters associated with glucose homeostasis under chow or high-fat diet. γ3 deficiency had no effect on fiber-type composition, mitochondrial content and components, or insulin-stimulated glucose uptake in skeletal muscle. Glycolytic muscles in γ3 KO mice showed a partial loss of AMPKα2 activity, which was associated with reduced levels of AMPKα2 and ß2 subunit isoforms. Notably, γ3 deficiency resulted in a selective loss of AICAR-, but not MK-8722-induced blood glucose-lowering in vivo and glucose uptake specifically in glycolytic muscle ex vivo. We detected γ3 in BAT and found that it preferentially interacts with α2 and ß2. We observed no differences in oxygen consumption, thermogenesis, morphology of BAT and inguinal white adipose tissue (iWAT), or markers of BAT activity between WT and γ3 KO mice. CONCLUSIONS: These results demonstrate that γ3 plays a key role in mediating AICAR- but not ADaM site binding drug-stimulated blood glucose clearance and glucose uptake specifically in glycolytic skeletal muscle. We also showed that γ3 is dispensable for ß3-adrenergic receptor agonist-induced thermogenesis and browning of iWAT.


Assuntos
Proteínas Quinases Ativadas por AMP/metabolismo , Glicemia/metabolismo , Fibras Musculares Esqueléticas/metabolismo , Proteínas Quinases Ativadas por AMP/genética , Tecido Adiposo Marrom/metabolismo , Aminoimidazol Carboxamida/administração & dosagem , Aminoimidazol Carboxamida/análogos & derivados , Animais , Benzimidazóis/administração & dosagem , Dieta Hiperlipídica , Feminino , Teste de Tolerância a Glucose , Insulina/metabolismo , Masculino , Taxa de Depuração Metabólica/efeitos dos fármacos , Camundongos , Camundongos Knockout , Modelos Animais , Piridinas/administração & dosagem , Ribonucleotídeos/administração & dosagem , Termogênese/efeitos dos fármacos
13.
Cell Stem Cell ; 28(6): 1125-1135.e7, 2021 06 03.
Artigo em Inglês | MEDLINE | ID: mdl-33609440

RESUMO

Tissue damage dramatically alters how cells interact with their microenvironment. These changes in turn dictate cellular responses, such as stem cell activation, yet early cellular responses in vivo remain ill defined. We generated single-cell and nucleus atlases from intact, dissociated, and injured muscle and liver and identified a common stress response signature shared by multiple cell types across these organs. This prevalent stress response was detected in published datasets across a range of tissues, demonstrating high conservation but also a significant degree of data distortion in single-cell reference atlases. Using quiescent muscle stem cells as a paradigm of cell activation following injury, we captured early cell activation following muscle injury and found that an essential ERK1/2 primary proliferation signal precedes initiation of the Notch-regulated myogenic program. This study defines initial events in response to tissue perturbation and identifies a broadly conserved transcriptional stress response that acts in parallel with cell-specific adaptive alterations.


Assuntos
Células Satélites de Músculo Esquelético , Proliferação de Células , Desenvolvimento Muscular , Músculos , Células-Tronco
14.
Nat Commun ; 11(1): 5102, 2020 10 09.
Artigo em Inglês | MEDLINE | ID: mdl-33037211

RESUMO

Skeletal muscle fibers are large syncytia but it is currently unknown whether gene expression is coordinately regulated in their numerous nuclei. Here we show by snRNA-seq and snATAC-seq that slow, fast, myotendinous and neuromuscular junction myonuclei each have different transcriptional programs, associated with distinct chromatin states and combinations of transcription factors. In adult mice, identified myofiber types predominantly express either a slow or one of the three fast isoforms of Myosin heavy chain (MYH) proteins, while a small number of hybrid fibers can express more than one MYH. By snRNA-seq and FISH, we show that the majority of myonuclei within a myofiber are synchronized, coordinately expressing only one fast Myh isoform with a preferential panel of muscle-specific genes. Importantly, this coordination of expression occurs early during post-natal development and depends on innervation. These findings highlight a previously undefined mechanism of coordination of gene expression in a syncytium.


Assuntos
Núcleo Celular/genética , Regulação da Expressão Gênica , Hibridização in Situ Fluorescente/métodos , Fibras Musculares Esqueléticas/citologia , Fibras Musculares Esqueléticas/fisiologia , Análise de Sequência de RNA/métodos , Animais , Feminino , Camundongos Endogâmicos C57BL , Músculo Esquelético/citologia , Músculo Esquelético/embriologia , Músculo Esquelético/crescimento & desenvolvimento , Cadeias Pesadas de Miosina/genética , Junção Neuromuscular/citologia , Análise de Célula Única , Tendões/citologia , Transcrição Gênica
15.
Rech Soins Infirm ; (141): 78-86, 2020 06.
Artigo em Francês | MEDLINE | ID: mdl-32988194

RESUMO

Despite its proven dangers, the ward stock drug distribution system predominates in French hospitals. This system allows 12 million injectable ampoules of concentrated potassium chloride to circulate uncontrolled each year. Such a situation is absurd for the following reasons : 1) injected by mistake, concentrated potassium kills within seconds ; 2) the true incidence of potassium-related fatalities and incidents is unknown ; 3) fatal intravenous injection of potassium produces no specific anatomical changes and subtle, if any, findings at autopsy ; 4) it is used for capital punishment by lethal injection in various countries ; and 5) healthcare worker serial killers benefit from the fact that potassium is not identifiable in post-mortem examinations and that investigations to find the murderer are complex and of uncertain outcome. Other medications classed as high-risk have similar characteristics to those of concentrated potassium solutions. Injectable potassium can therefore be regarded as emblematic of the lack of safety of the drug use process in French hospitals. The priority measure to protect patients from this deadly risk is to remove these drugs from uncontrolled ward stocks and to provide premixed potassium solutions. Evidence of the increased safety of the unit dose drug dispensing system should compel health policy makers to systematically implement it, thus bringing the drug use process into compliance with existing French and European regulations.


Assuntos
Segurança do Paciente/normas , Cloreto de Potássio/intoxicação , Controle de Medicamentos e Entorpecentes , França , Hospitais , Humanos , Injeções , Cloreto de Potássio/administração & dosagem , Cloreto de Potássio/química
16.
Development ; 147(19)2020 10 09.
Artigo em Inglês | MEDLINE | ID: mdl-32591430

RESUMO

Pax7 expression marks stem cells in developing skeletal muscles and adult satellite cells during homeostasis and muscle regeneration. The genetic determinants that control the entrance into the myogenic program and the appearance of PAX7+ cells during embryogenesis are poorly understood. SIX homeoproteins are encoded by the sine oculis-related homeobox Six1-Six6 genes in vertebrates. Six1, Six2, Six4 and Six5 are expressed in the muscle lineage. Here, we tested the hypothesis that Six1 and Six4 could participate in the genesis of myogenic stem cells. We show that fewer PAX7+ cells occupy a satellite cell position between the myofiber and its associated basal lamina in Six1 and Six4 knockout mice (s1s4KO) at E18. However, PAX7+ cells are detected in remaining muscle masses present in the epaxial region of the double mutant embryos and are able to divide and contribute to muscle growth. To further characterize the properties of s1s4KO PAX7+ cells, we analyzed their transcriptome and tested their properties after transplantation in adult regenerating tibialis anterior muscle. Mutant stem cells contribute to hypotrophic myofibers that are not innervated but retain the ability to self-renew.


Assuntos
Proteínas de Homeodomínio/metabolismo , Fator de Transcrição PAX7/metabolismo , Transativadores/metabolismo , Animais , Proteínas de Homeodomínio/genética , Camundongos , Camundongos Knockout , Desenvolvimento Muscular/genética , Desenvolvimento Muscular/fisiologia , Músculo Esquelético/embriologia , Músculo Esquelético/metabolismo , Fator de Transcrição PAX7/genética , Células-Tronco/citologia , Células-Tronco/metabolismo , Transativadores/genética
17.
Cell Death Differ ; 27(12): 3307-3320, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-32572167

RESUMO

During female mammal reproductive tract development, epithelial cells of the lower Müllerian duct are committed to become stratified squamous epithelium of the vagina and ectocervix, when the expression of ΔNp63 transcription factor is induced by mesenchymal cells. The absence of ΔNp63 expression leads to adenosis, the putative precursor of vaginal adenocarcinoma. Our previous studies with genetically engineered mouse models have established that fibroblast growth factor (FGF)/mitogen-activated protein kinase (MAPK), bone morphogenetic protein (BMP)/SMAD, and activin A/runt-related transcription factor 1 (RUNX1) signaling pathways are independently required for ΔNp63 expression in Müllerian duct epithelium (MDE). Here, we report that sine oculis homeobox homolog 1 (SIX1) plays a critical role in the activation of ΔNp63 locus in MDE as a downstream transcription factor of mesenchymal signals. In the developing mouse reproductive tract, SIX1 expression was restricted to MDE within the future cervix and vagina. SIX1 expression was totally absent in SMAD4 null MDE and was reduced in RUNX1 null and FGFR2 null MDE, indicating that SIX1 is under the control of vaginal mesenchymal factors: BMP4, activin A and FGF7/10. Furthermore, Six1, Runx1, and Smad4 gene-dose-dependently activated ΔNp63 expression in MDE within the vaginal fornix. Using a mouse model of diethylstilbestrol (DES)-associated vaginal adenosis, we found DES action through epithelial estrogen receptor α (ESR1) inhibits activation of ΔNp63 locus in MDE by transcriptionally repressing SIX1 and RUNX1 in the vaginal fornix.


Assuntos
Subunidade alfa 2 de Fator de Ligação ao Core/metabolismo , Epitélio/efeitos dos fármacos , Proteínas de Homeodomínio/metabolismo , Ductos Paramesonéfricos/efeitos dos fármacos , Proteína Smad4/metabolismo , Vagina/embriologia , Ativinas/metabolismo , Animais , Diferenciação Celular/fisiologia , Dietilestilbestrol/efeitos adversos , Estrogênios não Esteroides/efeitos adversos , Feminino , Regulação da Expressão Gênica no Desenvolvimento , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Análise de Sequência com Séries de Oligonucleotídeos , Transativadores/metabolismo , Útero/embriologia , Vagina/efeitos dos fármacos , Doenças Vaginais/induzido quimicamente
18.
Semin Cell Dev Biol ; 104: 51-64, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32247726

RESUMO

SIX homeoproteins were first described in Drosophila, where they participate in the Pax-Six-Eya-Dach (PSED) network with eyeless, eyes absent and dachsund to drive synergistically eye development through genetic and biochemical interactions. The role of the PSED network and SIX proteins in muscle formation in vertebrates was subsequently identified. Evolutionary conserved interactions with EYA and DACH proteins underlie the activity of SIX transcriptional complexes (STC) both during embryogenesis and in adult myofibers. Six genes are expressed throughout muscle development, in embryonic and adult proliferating myogenic stem cells and in fetal and adult post-mitotic myofibers, where SIX proteins regulate the expression of various categories of genes. In vivo, SIX proteins control many steps of muscle development, acting through feedforward mechanisms: in the embryo for myogenic fate acquisition through the direct control of Myogenic Regulatory Factors; in adult myofibers for their contraction/relaxation and fatigability properties through the control of genes involved in metabolism, sarcomeric organization and calcium homeostasis. Furthermore, during development and in the adult, SIX homeoproteins participate in the genesis and the maintenance of myofibers diversity.


Assuntos
Proteínas de Drosophila/metabolismo , Drosophila/crescimento & desenvolvimento , Drosophila/genética , Proteínas de Homeodomínio/metabolismo , Desenvolvimento Muscular/genética , Músculo Esquelético/metabolismo , Animais , Músculo Esquelético/citologia
19.
Rech Soins Infirm ; 141(2): 78-86, 2020.
Artigo em Francês | MEDLINE | ID: mdl-35724035

RESUMO

Despite its proven dangers, the ward stock drug distribution system predominates in French hospitals. This system allows 12 million injectable ampoules of concentrated potassium chloride to circulate uncontrolled each year. Such a situation is absurd for the following reasons : 1) injected by mistake, concentrated potassium kills within seconds ; 2) the true incidence of potassium-related fatalities and incidents is unknown ; 3) fatal intravenous injection of potassium produces no specific anatomical changes and subtle, if any, findings at autopsy ; 4) it is used for capital punishment by lethal injection in various countries ; and 5) healthcare worker serial killers benefit from the fact that potassium is not identifiable in post-mortem examinations and that investigations to find the murderer are complex and of uncertain outcome. Other medications classed as high-risk have similar characteristics to those of concentrated potassium solutions. Injectable potassium can therefore be regarded as emblematic of the lack of safety of the drug use process in French hospitals. The priority measure to protect patients from this deadly risk is to remove these drugs from uncontrolled ward stocks and to provide premixed potassium solutions. Evidence of the increased safety of the unit dose drug dispensing system should compel health policy makers to systematically implement it, thus bringing the drug use process into compliance with existing French and European regulations.

20.
Theranostics ; 9(3): 661-675, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30809300

RESUMO

Hypoxic zones are common features of metastatic tumors. Due to inactivation of the von Hippel-Lindau gene (VHL), renal cell carcinomas (RCC) show constitutive stabilization of the alpha subunit of the hypoxia-inducible factor (HIF). Thus, RCC represents a model of chronic hypoxia. Development of the lymphatic network is dependent on vascular endothelial growth factor C (VEGFC) and lies at the front line of metastatic spreading. Here, we addressed the role of VEGFC in RCC aggressiveness and the regulation of its expression in hypoxia. Methods: Transcriptional and post transcriptional regulation of VEGFC expression was evaluated by qPCR and with reporter genes. The involvement of HIF was evaluated using a siRNA approach. Experimental RCC were performed with immuno-competent/deficient mice using human and mouse cells knocked-out for the VEGFC gene by a CRISPR/Cas9 method. The VEGFC axis was analyzed with an online available data base (TCGA) and using an independent cohort of patients. Results: Hypoxia induced VEGFC protein expression but down-regulated VEGFC gene transcription and mRNA stability. Increased proliferation, migration, over-activation of the AKT signaling pathway and enhanced expression of mesenchymal markers characterized VEGFC-/- cells. VEGFC-/- cells did not form tumors in immuno-deficient mice but developed aggressive tumors in immuno-competent mice. These tumors showed down-regulation of markers of activated lymphocytes and M1 macrophages, and up-regulation of M2 macrophages markers and programmed death ligand 1 (PDL1). Over-expression of lymphangiogenic genes including VEGFC was linked to increased disease-free and overall survival in patients with non-metastatic tumors, whereas its over-expression correlated with decreased progression-free and overall survival of metastatic patients. Conclusion: Our study revisited the admitted dogma linking VEGFC to tumor aggressiveness. We conclude that targeting VEGFC for therapy must be considered with caution.


Assuntos
Carcinoma de Células Renais/patologia , Fator C de Crescimento do Endotélio Vascular/metabolismo , Animais , Linhagem Celular Tumoral , Modelos Animais de Doenças , Perfilação da Expressão Gênica , Humanos , Camundongos , Transplante de Neoplasias , Transplante Heterólogo
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