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1.
Immunity ; 57(1): 124-140.e7, 2024 Jan 09.
Artigo em Inglês | MEDLINE | ID: mdl-38157853

RESUMO

Natural killer (NK) cells are present in the circulation and can also be found residing in tissues, and these populations exhibit distinct developmental requirements and are thought to differ in terms of ontogeny. Here, we investigate whether circulating conventional NK (cNK) cells can develop into long-lived tissue-resident NK (trNK) cells following acute infections. We found that viral and bacterial infections of the skin triggered the recruitment of cNK cells and their differentiation into Tcf1hiCD69hi trNK cells that share transcriptional similarity with CD56brightTCF1hi NK cells in human tissues. Skin trNK cells arose from interferon (IFN)-γ-producing effector cells and required restricted expression of the transcriptional regulator Blimp1 to optimize Tcf1-dependent trNK cell formation. Upon secondary infection, trNK cells rapidly gained effector function and mediated an accelerated NK cell response. Thus, cNK cells redistribute and permanently position at sites of previous infection via a mechanism promoting tissue residency that is distinct from Hobit-dependent developmental paths of NK cells and ILC1 seeding tissues during ontogeny.


Assuntos
Coinfecção , Humanos , Células Matadoras Naturais/metabolismo , Diferenciação Celular
2.
Cell ; 157(2): 340-356, 2014 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-24725403

RESUMO

Innate lymphoid cells (ILCs) are a recently recognized group of lymphocytes that have important functions in protecting epithelial barriers against infections and in maintaining organ homeostasis. ILCs have been categorized into three distinct groups, transcriptional circuitry and effector functions of which strikingly resemble the various T helper cell subsets. Here, we identify a common, Id2-expressing progenitor to all interleukin 7 receptor-expressing, "helper-like" ILC lineages, the CHILP. Interestingly, the CHILP differentiated into ILC2 and ILC3 lineages, but not into conventional natural killer (cNK) cells that have been considered an ILC1 subset. Instead, the CHILP gave rise to a peculiar NKp46(+) IL-7Rα(+) ILC lineage that required T-bet for specification and was distinct of cNK cells or other ILC lineages. Such ILC1s coproduced high levels of IFN-γ and TNF and protected against infections with the intracellular parasite Toxoplasma gondii. Our data significantly advance our understanding of ILC differentiation and presents evidence for a new ILC lineage that protects barrier surfaces against intracellular infections.


Assuntos
Diferenciação Celular , Linfócitos/citologia , Linfócitos/imunologia , Animais , Células da Medula Óssea/citologia , Células da Medula Óssea/imunologia , Fator de Transcrição GATA3/metabolismo , Imunidade Inata , Proteína 2 Inibidora de Diferenciação/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Receptores de Interleucina-7/metabolismo , Células-Tronco/citologia , Toxoplasma , Toxoplasmose/imunologia
3.
Development ; 149(22)2022 11 15.
Artigo em Inglês | MEDLINE | ID: mdl-36326003

RESUMO

Stem cell-derived three-dimensional (3D) gastruloids show a remarkable capacity of self-organisation and recapitulate many aspects of gastrulation stage mammalian development. Gastruloids can be rapidly generated and offer several experimental advantages, such as scalability, observability and accessibility for manipulation. Here, we present approaches to further expand the experimental potency of murine 3D gastruloids by using functional genetics in mouse embryonic stem cells (mESCs) to generate chimeric gastruloids. In chimeric gastruloids, fluorescently labelled cells of different genotypes harbouring inducible gene expression or loss-of-function alleles are combined with wild-type cells. We showcase this experimental approach in chimeric gastruloids of mESCs carrying homozygous deletions of the Tbx transcription factor brachyury or inducible expression of Eomes. Resulting chimeric gastruloids recapitulate reported Eomes and brachyury functions, such as instructing cardiac fate and promoting posterior axial extension, respectively. Additionally, chimeric gastruloids revealed previously unrecognised phenotypes, such as the tissue sorting preference of brachyury deficient cells to endoderm and the cell non-autonomous effects of brachyury deficiency on Wnt3a patterning along the embryonic axis, demonstrating some of the advantages of chimeric gastruloids as an efficient tool for studies of mammalian gastrulation.


Assuntos
Gastrulação , Mamíferos , Animais , Camundongos , Endoderma , Células-Tronco Embrionárias Murinas , Alelos
4.
Development ; 148(1)2021 01 07.
Artigo em Inglês | MEDLINE | ID: mdl-33199445

RESUMO

Anterior mesoderm (AM) and definitive endoderm (DE) progenitors represent the earliest embryonic cell types that are specified during germ layer formation at the primitive streak (PS) of the mouse embryo. Genetic experiments indicate that both lineages segregate from Eomes-expressing progenitors in response to different Nodal signaling levels. However, the precise spatiotemporal pattern of the emergence of these cell types and molecular details of lineage segregation remain unexplored. We combined genetic fate labeling and imaging approaches with single-cell RNA sequencing (scRNA-seq) to follow the transcriptional identities and define lineage trajectories of Eomes-dependent cell types. Accordingly, all cells moving through the PS during the first day of gastrulation express Eomes AM and DE specification occurs before cells leave the PS from Eomes-positive progenitors in a distinct spatiotemporal pattern. ScRNA-seq analysis further suggested the immediate and complete separation of AM and DE lineages from Eomes-expressing cells as last common bipotential progenitor.


Assuntos
Linhagem da Célula , Endoderma/citologia , Endoderma/metabolismo , Gastrulação , Mesoderma/citologia , Mesoderma/metabolismo , Alelos , Animais , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Diferenciação Celular , Células Epiteliais/metabolismo , Regulação da Expressão Gênica no Desenvolvimento , Camadas Germinativas/citologia , Camundongos , Modelos Biológicos , Linha Primitiva/embriologia , Linha Primitiva/metabolismo , Células-Tronco/metabolismo , Proteínas com Domínio T/metabolismo , Fatores de Tempo , Transcrição Gênica
5.
Immunity ; 41(2): 230-43, 2014 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-25148024

RESUMO

CD8αα(+) intraepithelial lymphocytes (IELs) are instrumental in maintaining the epithelial barrier in the intestine. Similar to natural killer cells and other innate lymphoid cells, CD8αα(+) IELs constitutively express the T-box transcription factor T-bet. However, the precise role of T-bet for the differentiation or function of IELs is unknown. Here we show that mice genetically deficient for T-bet lacked both TCRαß(+) and TCRγδ(+) CD8αα(+) IELs and thus are more susceptible to chemically induced colitis. Although T-bet was induced in thymic IEL precursors (IELPs) as a result of agonist selection and interleukin-15 (IL-15) receptor signaling, it was dispensable for the generation of IELPs. Subsequently, T-bet was required for the IL-15-dependent activation, differentiation, and expansion of IELPs in the periphery. Our study reveals a function of T-bet as a central transcriptional regulator linking agonist selection and IL-15 signaling with the emergence of CD8αα(+) IELs.


Assuntos
Antígenos CD8/biossíntese , Interleucina-15/genética , Receptores de Antígenos de Linfócitos T alfa-beta/genética , Receptores de Antígenos de Linfócitos T gama-delta/genética , Proteínas com Domínio T/genética , Animais , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD8-Positivos/imunologia , Diferenciação Celular/imunologia , Colite/induzido quimicamente , Colite/imunologia , Células Epiteliais/imunologia , Interleucina-15/imunologia , Mucosa Intestinal/citologia , Mucosa Intestinal/imunologia , Intestinos/citologia , Intestinos/imunologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Receptores de Interleucina-15/imunologia , Transdução de Sinais/imunologia , Proteínas com Domínio T/biossíntese
6.
PLoS Pathog ; 16(9): e1008870, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32991634

RESUMO

The two T-box transcription factors T-bet and Eomesodermin (Eomes) are important regulators of cytotoxic lymphocytes (CTLs), such as activated CD8 T cells, which are essential in the fight against intracellular pathogens and tumors. Both transcription factors share a great degree of homology based on sequence analysis and as a result exert partial functional redundancy during viral infection. However, the actual degree of redundancy between T-bet and Eomes remains a matter of debate and is further confounded by their distinct spatiotemporal expression pattern in activated CD8 T cells. To directly investigate the functional overlap of these transcription factors, we generated a new mouse model in which Eomes expression is under the transcriptional control of the endogenous Tbx21 (encoding for T-bet) locus. Applying this model, we demonstrate that the induction of Eomes in lieu of T-bet cannot rescue T-bet deficiency in CD8 T cells during acute lymphocytic choriomeningitis virus (LCMV) infection. We found that the expression of Eomes instead of T-bet was not sufficient for early cell expansion or effector cell differentiation. Finally, we show that imposed expression of Eomes after acute viral infection promotes some features of exhaustion but must act in concert with other factors during chronic viral infection to establish all hallmarks of exhaustion. In summary, our results clearly underline the importance of T-bet in guiding canonical CTL development during acute viral infections.


Assuntos
Linfócitos T CD8-Positivos/metabolismo , Diferenciação Celular/fisiologia , Proteínas com Domínio T/metabolismo , Animais , Proliferação de Células , Células Cultivadas , Proteínas Fetais/metabolismo , Regulação da Expressão Gênica/fisiologia , Interferon gama/metabolismo , Camundongos Transgênicos
7.
Ultraschall Med ; 43(6): 608-613, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33951737

RESUMO

PURPOSE: We sought to determine the diagnostic agreement between the revised ultrasonography approach by the German Society of Ultrasound in Medicine (DEGUM) and the established Society of Radiologists in Ultrasound (SRU) consensus criteria for the grading of carotid artery disease. MATERIALS AND METHODS: Post-hoc analysis of a prospective multicenter study, in which patients underwent ultrasonography and digital subtraction angiography (DSA) of carotid arteries for validation of the DEGUM approach. According to DEGUM and SRU ultrasonography criteria, carotid arteries were independently categorized into clinically relevant NASCET strata (normal, mild [1-49 %], moderate [50-69 %], severe [70-99 %], occlusion). On DSA, carotid artery findings according to NASCET were considered the reference standard. RESULTS: We analyzed 158 ultrasonography and DSA carotid artery pairs. There was substantial agreement between both ultrasonography approaches for severe (κw 0.76, CI95 %: 0.66-0.86), but only fair agreement for moderate (κw 0.38, CI95 %: 0.19-0.58) disease categories. Compared with DSA, both ultrasonography approaches were of equal sensitivity (79.7 % versus 79.7 %; p = 1.0) regarding the identification of severe stenosis, yet the DEGUM approach was more specific than the SRU approach (70.2 % versus 56.4 %, p = 0.0002). There was equality of accuracy parameters (p > 0.05) among both ultrasonography approaches for the other ranges of carotid artery disease. CONCLUSION: While the sensitivity was equivalent, false-positive identification of severe carotid artery stenosis appears to be more frequent when using the SRU ultrasonography approach than the revised multiparametric DEGUM approach.


Assuntos
Doenças das Artérias Carótidas , Estenose das Carótidas , Humanos , Artéria Carótida Interna/diagnóstico por imagem , Estudos Prospectivos , Consenso , Estenose das Carótidas/diagnóstico por imagem , Angiografia Digital , Ultrassonografia , Radiologistas , Sensibilidade e Especificidade
8.
Nat Rev Mol Cell Biol ; 10(2): 91-103, 2009 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-19129791

RESUMO

Genetic studies have identified the key signalling pathways and developmentally regulated transcription factors that govern cell lineage allocation and axis patterning in the early mammalian embryo. Recent advances have uncovered details of the molecular circuits that tightly control cell growth and differentiation in the mammalian embryo from the blastocyst stage, through the establishment of initial anterior-posterior polarity, to gastrulation, when the germ cells are set aside and the three primary germ layers are specified. Relevant studies in lower vertebrates indicate the conservation and divergence of regulatory mechanisms for cell lineage allocation and axis patterning.


Assuntos
Padronização Corporal/fisiologia , Linhagem da Célula , Embrião de Mamíferos , Animais , Proteínas Morfogenéticas Ósseas/genética , Proteínas Morfogenéticas Ósseas/metabolismo , Proteínas de Ligação a DNA , Embrião de Mamíferos/anatomia & histologia , Embrião de Mamíferos/fisiologia , Gastrulação , Camundongos , Morfogênese , Fator 1 de Ligação ao Domínio I Regulador Positivo , Proteínas de Ligação a RNA , Transdução de Sinais/fisiologia , Proteínas Smad/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
9.
Development ; 144(21): 3917-3931, 2017 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-28939666

RESUMO

During corticogenesis, distinct classes of neurons are born from progenitor cells located in the ventricular and subventricular zones, from where they migrate towards the pial surface to assemble into highly organized layer-specific circuits. However, the precise and coordinated transcriptional network activity defining neuronal identity is still not understood. Here, we show that genetic depletion of the basic helix-loop-helix (bHLH) transcription factor E2A splice variant E47 increased the number of Tbr1-positive deep layer and Satb2-positive upper layer neurons at E14.5, while depletion of the alternatively spliced E12 variant did not affect layer-specific neurogenesis. While ChIP-Seq identified a big overlap for E12- and E47-specific binding sites in embryonic NSCs, including sites at the cyclin-dependent kinase inhibitor (CDKI) Cdkn1c gene locus, RNA-Seq revealed a unique transcriptional regulation by each splice variant. E47 activated the expression of the CDKI Cdkn1c through binding to a distal enhancer. Finally, overexpression of E47 in embryonic NSCs in vitro impaired neurite outgrowth, and overexpression of E47 in vivo by in utero electroporation disturbed proper layer-specific neurogenesis and upregulated p57(KIP2) expression. Overall, this study identifies E2A target genes in embryonic NSCs and demonstrates that E47 regulates neuronal differentiation via p57(KIP2).


Assuntos
Processamento Alternativo/genética , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Diferenciação Celular/genética , Córtex Cerebral/embriologia , Inibidor de Quinase Dependente de Ciclina p57/genética , Neurônios/citologia , Fator 3 de Transcrição/metabolismo , Animais , Sequência de Bases , Sítios de Ligação/genética , Ciclo Celular/genética , Córtex Cerebral/citologia , Cromatina/metabolismo , Inibidor de Quinase Dependente de Ciclina p57/metabolismo , Elementos Facilitadores Genéticos/genética , Regulação da Expressão Gênica no Desenvolvimento , Camundongos Endogâmicos C57BL , Células-Tronco Neurais/citologia , Células-Tronco Neurais/metabolismo , Neurogênese/genética , Neurônios/metabolismo , Ligação Proteica , Fator 3 de Transcrição/deficiência , Transcrição Gênica
10.
Hum Mutat ; 40(3): 267-280, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30520571

RESUMO

Next-generation sequencing (NGS) has been instrumental in solving the genetic basis of rare inherited diseases, especially neurodevelopmental syndromes. However, functional workup is essential for precise phenotype definition and to understand the underlying disease mechanisms. Using whole exome (WES) and whole genome sequencing (WGS) in four independent families with hypotonia, neurodevelopmental delay, facial dysmorphism, loss of white matter, and thinning of the corpus callosum, we identified four previously unreported homozygous truncating PPP1R21 alleles: c.347delT p.(Ile116Lysfs*25), c.2170_2171insGGTA p.(Ile724Argfs*8), c.1607dupT p.(Leu536Phefs*7), c.2063delA p.(Lys688Serfs*26) and found that PPP1R21 was absent in fibroblasts of an affected individual, supporting the allele's loss of function effect. PPP1R21 function had not been studied except that a large scale affinity proteomics approach suggested an interaction with PIBF1 defective in Joubert syndrome. Our co-immunoprecipitation studies did not confirm this but in contrast defined the localization of PPP1R21 to the early endosome. Consistent with the subcellular expression pattern and the clinical phenotype exhibiting features of storage diseases, we found patient fibroblasts exhibited a delay in clearance of transferrin-488 while uptake was normal. In summary, we delineate a novel neurodevelopmental syndrome caused by biallelic PPP1R21 loss of function variants, and suggest a role of PPP1R21 within the endosomal sorting process or endosome maturation pathway.


Assuntos
Alelos , Endocitose , Mutação com Perda de Função/genética , Transtornos do Neurodesenvolvimento/genética , Transtornos do Neurodesenvolvimento/patologia , Fosfoproteínas Fosfatases/genética , Adulto , Criança , Pré-Escolar , Endossomos/metabolismo , Endossomos/ultraestrutura , Feminino , Fibroblastos/metabolismo , Fibroblastos/ultraestrutura , Homozigoto , Humanos , Lactente , Recém-Nascido , Masculino , Bainha de Mielina/metabolismo , Bainha de Mielina/ultraestrutura , Linhagem , Fosfoproteínas Fosfatases/química , Síndrome , Transferrina/metabolismo
11.
EMBO J ; 34(8): 1078-89, 2015 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-25712475

RESUMO

Mucociliary clearance and fluid transport along epithelial surfaces are carried out by multiciliated cells (MCCs). Recently, human mutations in Cyclin O (CCNO) were linked to severe airway disease. Here, we show that Ccno expression is restricted to MCCs and the genetic deletion of Ccno in mouse leads to reduced numbers of multiple motile cilia and characteristic phenotypes of MCC dysfunction including severe hydrocephalus and mucociliary clearance deficits. Reduced cilia numbers are caused by compromised generation of centrioles at deuterosomes, which serve as major amplification platform for centrioles in MCCs. Ccno-deficient MCCs fail to sufficiently generate deuterosomes, and only reduced numbers of fully functional centrioles that undergo maturation to ciliary basal bodies are formed. Collectively, this study implicates CCNO as first known regulator of deuterosome formation and function for the amplification of centrioles in MCCs.


Assuntos
Centríolos/fisiologia , Ciclinas/fisiologia , Animais , Diferenciação Celular/genética , Células Cultivadas , Centríolos/ultraestrutura , Cílios/fisiologia , Cílios/ultraestrutura , Embrião de Mamíferos , Regulação da Expressão Gênica no Desenvolvimento , Hidrocefalia/embriologia , Hidrocefalia/genética , Camundongos , Camundongos Transgênicos , Depuração Mucociliar/genética , Organogênese/genética , Traqueia/citologia , Traqueia/embriologia , Traqueia/metabolismo
12.
Genes Dev ; 25(3): 238-50, 2011 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-21245162

RESUMO

Understanding the molecular mechanisms controlling early cell fate decisions in mammals is a major objective toward the development of robust methods for the differentiation of human pluripotent stem cells into clinically relevant cell types. Here, we used human embryonic stem cells and mouse epiblast stem cells to study specification of definitive endoderm in vitro. Using a combination of whole-genome expression and chromatin immunoprecipitation (ChIP) deep sequencing (ChIP-seq) analyses, we established an hierarchy of transcription factors regulating endoderm specification. Importantly, the pluripotency factors NANOG, OCT4, and SOX2 have an essential function in this network by actively directing differentiation. Indeed, these transcription factors control the expression of EOMESODERMIN (EOMES), which marks the onset of endoderm specification. In turn, EOMES interacts with SMAD2/3 to initiate the transcriptional network governing endoderm formation. Together, these results provide for the first time a comprehensive molecular model connecting the transition from pluripotency to endoderm specification during mammalian development.


Assuntos
Diferenciação Celular , Endoderma , Regulação da Expressão Gênica no Desenvolvimento , Células-Tronco Pluripotentes , Proteínas com Domínio T/metabolismo , Ativinas/metabolismo , Animais , Biomarcadores/metabolismo , Linhagem Celular , Endoderma/citologia , Endoderma/metabolismo , Redes Reguladoras de Genes/genética , Proteínas de Homeodomínio/metabolismo , Humanos , Camundongos , Proteína Homeobox Nanog , Proteína Nodal/metabolismo , Fator 3 de Transcrição de Octâmero/metabolismo , Células-Tronco Pluripotentes/citologia , Células-Tronco Pluripotentes/metabolismo , Fatores de Transcrição SOXB1/metabolismo , Proteínas com Domínio T/genética
13.
Glia ; 66(8): 1566-1576, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-29537098

RESUMO

Adult hippocampal neurogenesis is implicated in learning and memory processing. It is tightly controlled at several levels including progenitor proliferation as well as migration, differentiation and integration of new neurons. Hippocampal progenitors and immature neurons reside in the subgranular zone (SGZ) and are equipped with the CXCL12-receptor CXCR4 which contributes to defining the SGZ as neurogenic niche. The atypical CXCL12-receptor CXCR7 functions primarily by sequestering extracellular CXCL12 but whether CXCR7 is involved in adult neurogenesis has not been assessed. We report that granule neurons (GN) upregulate CXCL12 and CXCR7 during dentate gyrus maturation in the second postnatal week. To test whether GN-derived CXCL12 regulates neurogenesis and if neuronal CXCR7 receptors influence this process, we conditionally deleted Cxcl12 and Cxcr7 from the granule cell layer. Cxcl12 deletion resulted in lower numbers, increased dispersion and abnormal dendritic growth of immature GN and reduced neurogenesis. Cxcr7 ablation caused an increase in progenitor proliferation and progenitor numbers and reduced dispersion of immature GN. Thus, we provide a new mechanism where CXCL12-signals from GN prevent dispersion and support maturation of newborn GN. CXCR7 receptors of GN modulate the CXCL12-mediated feedback from GN to the neurogenic niche.


Assuntos
Quimiocina CXCL12/metabolismo , Giro Denteado/metabolismo , Neurogênese/fisiologia , Neurônios/metabolismo , Animais , Diferenciação Celular/fisiologia , Proliferação de Células/fisiologia , Dendritos/metabolismo , Hipocampo/metabolismo , Camundongos Transgênicos , Células-Tronco Neurais/metabolismo
14.
Ultraschall Med ; 39(5): 535-543, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-29797307

RESUMO

PURPOSE: The German Society of Ultrasound in Medicine (DEGUM) recently revised its multiparametric criteria for duplex ultrasonography (DUS) grading of internal carotid artery (ICA) disease. We determined the diagnostic accuracy of the revised DEGUM criteria for ultrasonography grading of ICA disease in a prospective multicenter study. MATERIALS AND METHODS: We evaluated consecutive patients who underwent digital subtraction angiography of the extracranial carotid arteries at four tertiary care hospitals. Blinded investigators graded ICA disease according to DEGUM-recommended ultrasonography criteria and calculated NASCET-type percent stenosis from angiography images. Endpoints included overall classification accuracy, prediction of clinically relevant disease categories and between-test agreement in the continuous range of percent stenosis. RESULTS: A total of 121 patients (median age: 69 [IQR, 16] years; 74 % men; median time between DUS and angiography: 1 day [IQR, 2]) provided 163 DUS-angiography carotid artery pairs. The classification accuracy of the DEGUM criteria to predict stenosis within 10 % increments as compared to angiography was 34.9 % (95 % CI, 28.0 - 42.6). The sensitivity of DUS for the detection of moderate (50 - 69 %) and severe (70 - 99 %) stenosis was 35 % and 81 %, with an overall accuracy of 73 % and 74 %, respectively. The specificity was 89 % and 69 %, respectively. Considering the continuous spectrum of the disease (0 - 100 %), the Bland-Altman interval limit of agreement was 51 %. CONCLUSION: At laboratories experienced with ultrasound grading of the extracranial ICA, the revised DEGUM multiparametric ultrasonography criteria do not eliminate the need for a confirmatory test for the identification of clinically relevant grades of the disease.


Assuntos
Angiografia Digital , Doenças das Artérias Carótidas , Estenose das Carótidas , Idoso , Doenças das Artérias Carótidas/diagnóstico por imagem , Artéria Carótida Interna/diagnóstico por imagem , Estenose das Carótidas/diagnóstico por imagem , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Ultrassonografia , Ultrassonografia Doppler Dupla
15.
Genesis ; 55(8)2017 08.
Artigo em Inglês | MEDLINE | ID: mdl-28646547

RESUMO

The T-box transcription factor Eomes (also known as Tbr2) shows short-lived expression in various localized domains of the embryo, including epiblast cells during gastrulation and intermediate progenitor cells in the cerebral cortex. In these tissues Eomes fulfills crucial roles for lineage specification of progenitors. To directly observe Eomes-dependent cell lineages in the living embryo, we generated a novel dual-fluorescence reporter allele that expresses a membrane-bound tdTomato protein for investigation of cell morphology and a nuclear GFP for cell tracing. This allele recapitulates endogenous EOMES protein expression and is suitable for live imaging. We found that the allele can also be used as a short-to-medium-term lineage tracer, as GFP persists in cells longer than EOMES protein and marks Eomes-dependent lineages with a timeframe of days to weeks depending on the proliferation rate. In summary, we present a novel genetic tool for investigation of Eomes-dependent cell types by live imaging and lineage tracing.


Assuntos
Linhagem da Célula , Rastreamento de Células/métodos , Genes Reporter , Engenharia Genética/métodos , Imagem Óptica/métodos , Proteínas com Domínio T/genética , Animais , Feminino , Proteínas Luminescentes/genética , Proteínas Luminescentes/metabolismo , Masculino , Camundongos , Proteínas com Domínio T/metabolismo
16.
Pflugers Arch ; 469(2): 303-311, 2017 02.
Artigo em Inglês | MEDLINE | ID: mdl-27987038

RESUMO

Recent advances in genome editing technologies have enabled the rapid and precise manipulation of genomes, including the targeted introduction, alteration, and removal of genomic sequences. However, respective methods have been described mainly in non-differentiated or haploid cell types. Genome editing of well-differentiated renal epithelial cells has been hampered by a range of technological issues, including optimal design, efficient expression of multiple genome editing constructs, attainable mutation rates, and best screening strategies. Here, we present an easily implementable workflow for the rapid generation of targeted heterozygous and homozygous genomic sequence alterations in renal cells using transcription activator-like effector nucleases (TALENs) and the clustered regularly interspaced short palindromic repeat (CRISPR) system. We demonstrate the versatility of established protocols by generating novel cellular models for studying autosomal dominant polycystic kidney disease (ADPKD). Furthermore, we show that cell culture-validated genetic modifications can be readily applied to mouse embryonic stem cells (mESCs) for the generation of corresponding mouse models. The described procedure for efficient genome editing can be applied to any cell type to study physiological and pathophysiological functions in the context of precisely engineered genotypes.


Assuntos
Diferenciação Celular/genética , Células Epiteliais/metabolismo , Genoma/genética , Rim/metabolismo , Animais , Repetições Palindrômicas Curtas Agrupadas e Regularmente Espaçadas/genética , DNA Complementar/genética , Células-Tronco Embrionárias/metabolismo , Edição de Genes/métodos , Genótipo , Humanos , Camundongos , Doenças Renais Policísticas/genética , Nucleases dos Efetores Semelhantes a Ativadores de Transcrição/genética
17.
Cell Tissue Res ; 369(1): 185-197, 2017 07.
Artigo em Inglês | MEDLINE | ID: mdl-28560692

RESUMO

Growing knowledge of how cell identity is determined at the molecular level has enabled the generation of diverse tissue types, including renal cells from pluripotent or somatic cells. Recently, several in vitro protocols involving either directed differentiation or transcription-factor-based reprogramming to kidney cells have been established. Embryonic stem cells or induced pluripotent stem cells can be guided towards a kidney fate by exposing them to combinations of growth factors or small molecules. Here, renal development is recapitulated in vitro resulting in kidney cells or organoids that show striking similarities to mammalian embryonic nephrons. In addition, culture conditions are also defined that allow the expansion of renal progenitor cells in vitro. Another route towards the generation of kidney cells is direct reprogramming. Key transcription factors are used to directly impose renal cell identity on somatic cells, thus circumventing the pluripotent stage. This complementary approach to stem-cell-based differentiation has been demonstrated to generate renal tubule cells and nephron progenitors. In-vitro-generated renal cells offer new opportunities for modelling inherited and acquired renal diseases on a patient-specific genetic background. These cells represent a potential source for developing novel models for kidney diseases, drug screening and nephrotoxicity testing and might represent the first steps towards kidney cell replacement therapies. In this review, we summarize current approaches for the generation of renal cells in vitro and discuss the advantages of each approach and their potential applications.


Assuntos
Técnicas de Reprogramação Celular/métodos , Reprogramação Celular , Regulação da Expressão Gênica , Rim , Engenharia Tecidual/métodos , Fatores de Transcrição , Animais , Humanos , Rim/citologia , Rim/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
18.
J Immunol ; 195(10): 4742-52, 2015 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-26453746

RESUMO

CD4(+) T cells polarize into effector Th subsets characterized by signature transcription factors and cytokines. Although T-bet drives Th1 responses and represses the alternative Th2, Th17, and Foxp3(+) regulatory T cell fates, the role of the T-bet-related transcription factor eomesodermin (Eomes) in CD4(+) T cells is less well understood. In this study, we analyze the expression and effects of Eomes in mouse CD4(+) T lymphocytes. We find that Eomes is readily expressed in activated CD4(+) Th1 T cells in vivo. Eomes(+) CD4(+) T cells accumulated in old mice, under lymphopenic conditions in a T cell transfer model of colitis, and upon oral Ag administration. However, despite its expression, genetic deletion of Eomes in CD4(+) T cells did not impact on IFN-γ production nor increase Th2 or Th17 responses. In contrast, Eomes deficiency favored the accumulation of Foxp3(+) cells in old mice, after in vivo differentiation of Eomes-deficient naive CD4(+) T cells, and in response to oral Ag in a cell-intrinsic way. Enforced Eomes expression during in vitro regulatory T cell induction also reduced Foxp3 transcription. Likewise, bystander Eomes-deficient CD4(+) T cells were more efficient at protecting from experimental autoimmune encephalitis compared with wild-type CD4(+) T cells. This enhanced capacity of Eomes-deficient CD4(+) T cells to inhibit EAE in trans was associated with an enhanced frequency of Foxp3(+) cells. Our data identify a novel role for Eomes in CD4(+) T cells and indicate that Eomes expression may act by limiting Foxp3 induction, which may contribute to the association of EOMES to susceptibility to multiple sclerosis.


Assuntos
Linfócitos T CD4-Positivos/metabolismo , Encefalomielite Autoimune Experimental/imunologia , Fatores de Transcrição Forkhead/biossíntese , Proteínas com Domínio T/fisiologia , Envelhecimento/imunologia , Animais , Linfócitos T CD4-Positivos/imunologia , Diferenciação Celular/imunologia , Modelos Animais de Doenças , Interferon gama/biossíntese , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Proteínas com Domínio T/genética , Linfócitos T Reguladores/imunologia , Linfócitos T Reguladores/metabolismo , Células Th1/imunologia , Células Th1/metabolismo , Células Th17/imunologia , Células Th17/metabolismo , Células Th2/imunologia , Células Th2/metabolismo
19.
J Neurosci ; 35(38): 13053-63, 2015 Sep 23.
Artigo em Inglês | MEDLINE | ID: mdl-26400936

RESUMO

Glutamatergic principal neurons, GABAergic interneurons and thalamocortical axons (TCAs) are essential elements of the cerebrocortical network. Principal neurons originate locally from radial glia and intermediate progenitors (IPCs), whereas interneurons and TCAs are of extrinsic origin. Little is known how the assembly of these elements is coordinated. C-X-C motif chemokine 12 (CXCL12), which is known to guide axons outside the neural tube and interneurons in the cortex, is expressed in the meninges and IPCs. Using mouse genetics, we dissected the influence of IPC-derived CXCL12 on TCAs and interneurons by showing that Cxcl12 ablation in IPCs, leaving meningeal Cxcl12 intact, attenuates intracortical TCA growth and disrupts tangential interneuron migration in the subventricular zone. In accordance with strong CXCR4 expression in the forming thalamus and TCAs, we identified a CXCR4-dependent growth-promoting effect of CXCL12 on TCAs in thalamus explants. Together, our findings indicate a cell-autonomous role of CXCR4 in promoting TCA growth. We propose that CXCL12 signals from IPCs link cortical neurogenesis to the progression of TCAs and interneurons spatially and temporally. Significance statement: The cerebral cortex exerts higher brain functions including perceptual and emotional processing. Evolutionary expansion of the mammalian cortex is mediated by intermediate progenitors, transient amplifying cells generating cortical excitatory neurons. During the peak period of cortical neurogenesis, migrating precursors of inhibitory interneurons originating in subcortical areas and thalamic axons invade the cortex. Although defects in the assembly of cortical network elements cause neurological and mental disorders, little is known how neurogenesis, interneuron recruitment, and axonal ingrowth are coordinated. We demonstrate that intermediate progenitors release the chemotactic cytokine CXCL12 to promote intracortical interneuron migration and growth of thalamic axons via the cognate receptor CXCR4. This paracrine signal may ensure thalamocortical connectivity and dispersion of inhibitory neurons in the rapidly growing cortex.


Assuntos
Córtex Cerebral/citologia , Quimiocina CXCL12/metabolismo , Interneurônios/fisiologia , Transdução de Sinais/fisiologia , Células-Tronco/fisiologia , Tálamo/citologia , Animais , Axônios/metabolismo , Córtex Cerebral/embriologia , Quimiocina CXCL12/genética , Embrião de Mamíferos , Regulação da Expressão Gênica no Desenvolvimento/genética , Filamentos Intermediários/metabolismo , Proteínas Luminescentes/genética , Proteínas Luminescentes/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Proteínas do Tecido Nervoso , Vias Neurais/fisiologia , Técnicas de Cultura de Órgãos , Receptores CXCR/genética , Receptores CXCR/metabolismo , Receptores CXCR4/genética , Receptores CXCR4/metabolismo , Tálamo/embriologia
20.
Cereb Cortex ; 25(10): 3290-302, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-24927931

RESUMO

The individual contribution of different progenitor subtypes towards the mature rodent cerebral cortex is not fully understood. Intermediate progenitor cells (IPCs) are key to understanding the regulation of neuronal number during cortical development and evolution, yet their exact contribution is much debated. Intermediate progenitors in the cortical subventricular zone are defined by expression of T-box brain-2 (Tbr2). In this study we demonstrate by using the Tbr2(Cre) mouse line and state-of-the-art cell lineage labeling techniques, that IPC derived cells contribute substantial proportions 67.5% of glutamatergic but not GABAergic or astrocytic cells to all cortical layers including the earliest generated subplate zone. We also describe the laminar dispersion of clonally derived cells from IPCs using a recently described clonal analysis tool (CLoNe) and show that pair-generated cells in different layers cluster closer (142.1 ± 76.8 µm) than unrelated cells (294.9 ± 105.4 µm). The clonal dispersion from individual Tbr2 positive intermediate progenitors contributes to increasing the cortical surface. Our study also describes extracortical contributions from Tbr2+ progenitors to the lateral olfactory tract and ventromedial hypothalamic nucleus.


Assuntos
Córtex Cerebral/embriologia , Células-Tronco Neurais/fisiologia , Células-Tronco/fisiologia , Proteínas com Domínio T/metabolismo , Animais , Astrócitos/metabolismo , Astrócitos/fisiologia , Encéfalo/embriologia , Encéfalo/metabolismo , Córtex Cerebral/metabolismo , Neurônios GABAérgicos/metabolismo , Neurônios GABAérgicos/fisiologia , Ventrículos Laterais/metabolismo , Ventrículos Laterais/fisiologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Células-Tronco Neurais/metabolismo , Células-Tronco/metabolismo , Proteínas com Domínio T/genética
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