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1.
Cells ; 10(9)2021 08 24.
Artigo em Inglês | MEDLINE | ID: mdl-34571821

RESUMO

We know little about the control of positional information (PI) during axolotl limb regeneration, which ensures that the limb regenerates exactly what was amputated, and the work reported here investigates this phenomenon. Retinoic acid administration changes the PI in a proximal direction so that a complete limb can be regenerated from a hand. Rather than identifying all the genes altered by RA treatment of the limb, we have eliminated many off-target effects by using retinoic acid receptor selective agonists. We firstly identify the receptor involved in this respecification process as RARα and secondly, identify the genes involved by RNA sequencing of the RARα-treated blastemal mesenchyme. We find 1177 upregulated genes and 1403 downregulated genes, which could be identified using the axolotl genome. These include several genes known to be involved in retinoic acid metabolism and in patterning. Since positional information is thought to be a property of the cell surface of blastemal cells when we examine our dataset with an emphasis on this aspect, we find the top canonical pathway is integrin signaling. In the extracellular matrix compartment, we find a MMP and several collagens are upregulated; several cell membrane genes and secretory factors are also upregulated. This provides data for future testing of the function of these candidates in the control of PI during limb regeneration.


Assuntos
Ambystoma mexicanum/metabolismo , Extremidades/fisiologia , Receptores do Ácido Retinoico/metabolismo , Regeneração/fisiologia , Animais , Matriz Extracelular/metabolismo , Mesoderma/metabolismo , Mesoderma/fisiologia , Transdução de Sinais/fisiologia , Tretinoína/metabolismo
2.
Development ; 148(15)2021 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-34338289

RESUMO

Transcriptional regulatory networks refine gene expression boundaries to define the dimensions of organ progenitor territories. Kidney progenitors originate within the intermediate mesoderm (IM), but the pathways that establish the boundary between the IM and neighboring vessel progenitors are poorly understood. Here, we delineate roles for the zinc-finger transcription factor Osr1 in kidney and vessel progenitor development. Zebrafish osr1 mutants display decreased IM formation and premature emergence of lateral vessel progenitors (LVPs). These phenotypes contrast with the increased IM and absent LVPs observed with loss of the bHLH transcription factor Hand2, and loss of hand2 partially suppresses osr1 mutant phenotypes. hand2 and osr1 are expressed together in the posterior mesoderm, but osr1 expression decreases dramatically prior to LVP emergence. Overexpressing osr1 during this timeframe inhibits LVP development while enhancing IM formation, and can rescue the osr1 mutant phenotype. Together, our data demonstrate that osr1 modulates the extent of IM formation and the temporal dynamics of LVP development, suggesting that a balance between levels of osr1 and hand2 expression is essential to demarcate the kidney and vessel progenitor territories.


Assuntos
Diferenciação Celular/fisiologia , Mesoderma/metabolismo , Mesoderma/fisiologia , Proteínas de Peixe-Zebra/metabolismo , Peixe-Zebra/metabolismo , Peixe-Zebra/fisiologia , Animais , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Regulação da Expressão Gênica no Desenvolvimento/fisiologia , Rim/metabolismo , Rim/fisiologia , Organogênese/fisiologia , Fatores de Transcrição/metabolismo
3.
Science ; 373(6552)2021 07 16.
Artigo em Inglês | MEDLINE | ID: mdl-34437124

RESUMO

Oocytes mature in a specialized fluid-filled sac, the ovarian follicle, which provides signals needed for meiosis and germ cell growth. Methods have been developed to generate functional oocytes from pluripotent stem cell-derived primordial germ cell-like cells (PGCLCs) when placed in culture with embryonic ovarian somatic cells. In this study, we developed culture conditions to recreate the stepwise differentiation process from pluripotent cells to fetal ovarian somatic cell-like cells (FOSLCs). When FOSLCs were aggregated with PGCLCs derived from mouse embryonic stem cells, the PGCLCs entered meiosis to generate functional oocytes capable of fertilization and development to live offspring. Generating functional mouse oocytes in a reconstituted ovarian environment provides a method for in vitro oocyte production and follicle generation for a better understanding of mammalian reproduction.


Assuntos
Células-Tronco Embrionárias Murinas/fisiologia , Oócitos/fisiologia , Oogênese , Folículo Ovariano/citologia , Animais , Técnicas de Cultura de Células , Diferenciação Celular , Desenvolvimento Embrionário , Feminino , Fertilização In Vitro , Masculino , Mesoderma/citologia , Mesoderma/fisiologia , Camundongos , Camundongos Endogâmicos ICR , Células-Tronco Embrionárias Murinas/citologia , Oócitos/citologia , Folículo Ovariano/embriologia , Folículo Ovariano/fisiologia , RNA-Seq , Fator Esteroidogênico 1/genética , Fator Esteroidogênico 1/metabolismo , Transcriptoma
4.
Dev Cell ; 56(6): 826-841.e4, 2021 03 22.
Artigo em Inglês | MEDLINE | ID: mdl-33705692

RESUMO

We describe a cellular contractile mechanism employed by fibroblasts and mesenchymal cancer cells to migrate in 3D collagen gels. During 3D spreading, fibroblasts strongly deform the matrix. They protrude, polarize, and initiate migration in the direction of highest extracellular matrix (ECM) deformation (prestrain). This prestrain is maintained through anterior cellular contractions behind the leading edge prior to protrusion, coordinating a distinct 3D migration cycle that varies between cell types. Myosin IIA is required for strain polarization, generating anterior contractions, and maintaining prestrain for efficient directional cell migration. Local matrix severing disrupts the matrix prestrain, suppressing directional protrusion. We show that epithelial cancer and endothelial cells rarely demonstrate the sustained prestrain or anterior contractions. We propose that mesenchymal cells sense ECM stiffness in 3D and generate their own matrix prestrain. This requires myosin IIA to generate polarized periodic anterior contractions for maintaining a 3D migration cycle.


Assuntos
Neoplasias da Mama/patologia , Movimento Celular , Matriz Extracelular/fisiologia , Fibroblastos/fisiologia , Mesoderma/fisiologia , Miosina não Muscular Tipo IIA/metabolismo , Estresse Mecânico , Neoplasias da Mama/metabolismo , Adesão Celular , Células Cultivadas , Feminino , Fibroblastos/citologia , Humanos , Mesoderma/citologia
5.
Development ; 148(18)2021 03 29.
Artigo em Inglês | MEDLINE | ID: mdl-33674259

RESUMO

During Xenopus gastrulation, leading edge mesendoderm (LEM) advances animally as a wedge-shaped cell mass over the vegetally moving blastocoel roof (BCR). We show that close contact across the BCR-LEM interface correlates with attenuated net advance of the LEM, which is pulled forward by tip cells while the remaining LEM frequently separates from the BCR. Nevertheless, lamellipodia persist on the detached LEM surface. They attach to adjacent LEM cells and depend on PDGF-A, cell-surface fibronectin and cadherin. We argue that active cell motility on the LEM surface prevents adverse capillary effects in the liquid LEM tissue as it moves by being pulled. It counters tissue surface-tension effects with oriented cell movement and bulges the LEM surface out to keep it close to the curved BCR without attaching to it. Proximity to the BCR is necessary, in turn, for the maintenance and orientation of lamellipodia that permit mass cell movement with minimal substratum contact. Together with a similar process in epithelial invagination, vertical telescoping, the cell movement at the LEM surface defines a novel type of cell rearrangement: vertical shearing.


Assuntos
Movimento Celular/fisiologia , Gastrulação/fisiologia , Mesoderma/fisiologia , Xenopus laevis/fisiologia , Animais , Caderinas/metabolismo , Ação Capilar , Adesão Celular/fisiologia , Endoderma/metabolismo , Endoderma/fisiologia , Fibronectinas/metabolismo , Gástrula/metabolismo , Gástrula/fisiologia , Mesoderma/metabolismo , Pseudópodes/metabolismo , Pseudópodes/fisiologia , Xenopus laevis/metabolismo
6.
Nat Commun ; 12(1): 1157, 2021 02 19.
Artigo em Inglês | MEDLINE | ID: mdl-33608545

RESUMO

Somites arising from paraxial mesoderm are a hallmark of the segmented vertebrate body plan. They form sequentially during axis extension and generate musculoskeletal cell lineages. How paraxial mesoderm becomes regionalised along the axis and how this correlates with dynamic changes of chromatin accessibility and the transcriptome remains unknown. Here, we report a spatiotemporal series of ATAC-seq and RNA-seq along the chick embryonic axis. Footprint analysis shows differential coverage of binding sites for several key transcription factors, including CDX2, LEF1 and members of HOX clusters. Associating accessible chromatin with nearby expressed genes identifies cis-regulatory elements (CRE) for TCF15 and MEOX1. We determine their spatiotemporal activity and evolutionary conservation in Xenopus and human. Epigenome silencing of endogenous CREs disrupts TCF15 and MEOX1 gene expression and recapitulates phenotypic abnormalities of anterior-posterior axis extension. Our integrated approach allows dissection of paraxial mesoderm regulatory circuits in vivo and has implications for investigating gene regulatory networks.


Assuntos
Embrião de Galinha/fisiologia , Cromatina , Regulação da Expressão Gênica no Desenvolvimento , Mesoderma/fisiologia , Sequências Reguladoras de Ácido Nucleico/fisiologia , Transcriptoma , Animais , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Fator de Transcrição CDX2/genética , Fator de Transcrição CDX2/metabolismo , Linhagem da Célula , Feminino , Gastrulação/genética , Gastrulação/fisiologia , Proteínas de Homeodomínio/genética , Proteínas de Homeodomínio/metabolismo , Fator 1 de Ligação ao Facilitador Linfoide/genética , Fator 1 de Ligação ao Facilitador Linfoide/metabolismo , Somitos/metabolismo , Fatores de Transcrição/metabolismo , Xenopus laevis
7.
Dev Biol ; 473: 119-129, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33607112

RESUMO

Retinoic acid (RA) signaling is required to restrict heart size through limiting the posterior boundary of the vertebrate cardiac progenitor field within the anterior lateral plate mesoderm (ALPM). However, we still do not fully understand how different cardiac progenitor populations that contribute to the developing heart, including earlier-differentiating first heart field (FHF), later-differentiating second heart field (SHF), and neural crest-derived progenitors, are each affected in RA-deficient embryos. Here, we quantified the number of cardiac progenitors and differentiating cardiomyocytes (CMs) in RA-deficient zebrafish embryos. While Nkx2.5+ cells were increased overall in the nascent hearts of RA-deficient embryos, unexpectedly, we found that the major effect within this population was a significant expansion in the number of differentiating FHF CMs. In contrast to the expansion of the FHF, there was a progressive decrease in SHF progenitors at the arterial pole as the heart tube elongated. Temporal differentiation assays and immunostaining in RA-deficient embryos showed that the outflow tracts (OFTs) of the hearts were significantly smaller, containing fewer differentiated SHF-derived ventricular CMs and a complete absence of SHF-derived smooth muscle at later stages. At the venous pole of the heart, pacemaker cells of the sinoatrial node also failed to differentiate in RA-deficient embryos. Interestingly, genetic lineage tracing showed that the number of neural-crest derived CMs was not altered within the enlarged hearts of RA-deficient zebrafish embryos. Altogether, our data show that the enlarged hearts in RA-deficient zebrafish embryos are comprised of an expansion in earlier differentiating FHF-derived CMs coupled with a progressive depletion of the SHF, suggesting RA signaling determines the relative ratios of earlier- and later-differentiation cardiac progenitors within an expanded cardiac progenitor pool.


Assuntos
Coração/embriologia , Mesoderma/metabolismo , Tretinoína/metabolismo , Animais , Diferenciação Celular/genética , Linhagem da Célula/genética , Regulação da Expressão Gênica no Desenvolvimento/genética , Coração/fisiologia , Ventrículos do Coração/metabolismo , Mesoderma/fisiologia , Miocárdio/metabolismo , Miócitos Cardíacos/metabolismo , Organogênese/genética , Transdução de Sinais/genética , Fatores de Transcrição/metabolismo , Tretinoína/fisiologia , Peixe-Zebra/metabolismo , Proteínas de Peixe-Zebra/metabolismo
8.
PLoS Biol ; 19(1): e3001060, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33406067

RESUMO

Collective migration of cohesive tissues is a fundamental process in morphogenesis and is particularly well illustrated during gastrulation by the rapid and massive internalization of the mesoderm, which contrasts with the much more modest movements of the ectoderm. In the Xenopus embryo, the differences in morphogenetic capabilities of ectoderm and mesoderm can be connected to the intrinsic motility of individual cells, very low for ectoderm, high for mesoderm. Surprisingly, we find that these seemingly deep differences can be accounted for simply by differences in Rho-kinases (Rock)-dependent actomyosin contractility. We show that Rock inhibition is sufficient to rapidly unleash motility in the ectoderm and confer it with mesoderm-like properties. In the mesoderm, this motility is dependent on two negative regulators of RhoA, the small GTPase Rnd1 and the RhoGAP Shirin/Dlc2/ArhGAP37. Both are absolutely essential for gastrulation. At the cellular and tissue level, the two regulators show overlapping yet distinct functions. They both contribute to decrease cortical tension and confer motility, but Shirin tends to increase tissue fluidity and stimulate dispersion, while Rnd1 tends to favor more compact collective migration. Thus, each is able to contribute to a specific property of the migratory behavior of the mesoderm. We propose that the "ectoderm to mesoderm transition" is a prototypic case of collective migration driven by a down-regulation of cellular tension, without the need for the complex changes traditionally associated with the epithelial-to-mesenchymal transition.


Assuntos
Actomiosina/metabolismo , Ectoderma/fisiologia , Mesoderma/fisiologia , Animais , Movimento Celular/genética , Regulação para Baixo/fisiologia , Ectoderma/embriologia , Embrião não Mamífero , Transição Epitelial-Mesenquimal/fisiologia , Proteínas Ativadoras de GTPase/genética , Proteínas Ativadoras de GTPase/metabolismo , Gastrulação/fisiologia , Regulação da Expressão Gênica no Desenvolvimento , Mesoderma/embriologia , Morfogênese/fisiologia , Transporte Proteico/genética , Transdução de Sinais/genética , Distribuição Tecidual/genética , Proteínas de Xenopus/genética , Proteínas de Xenopus/metabolismo , Xenopus laevis , Proteínas rho de Ligação ao GTP/genética , Proteínas rho de Ligação ao GTP/metabolismo
9.
Dev Biol ; 470: 74-83, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33159936

RESUMO

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


Assuntos
Gastrulação , Proteínas de Xenopus/fisiologia , Xenopus laevis/embriologia , Proteínas Adaptadoras de Transdução de Sinal/imunologia , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Animais , Anticorpos Monoclonais/imunologia , Movimento Celular , Ectoderma/citologia , Ectoderma/embriologia , Ectoderma/patologia , Indução Embrionária , Endoderma/citologia , Endoderma/embriologia , Endoderma/fisiologia , Fibronectinas/metabolismo , Mesoderma/citologia , Mesoderma/embriologia , Mesoderma/fisiologia , Morfolinos , Crista Neural/citologia , Crista Neural/embriologia , Proteólise , Ribonucleoproteínas/genética , Ribonucleoproteínas/metabolismo , Proteínas de Xenopus/genética , Proteínas de Xenopus/imunologia , Proteínas de Xenopus/metabolismo
10.
PLoS Biol ; 18(12): e3001032, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-33306673

RESUMO

Despite recent progress in recognizing the importance of mesenchymal cells for the homeostasis of the intestinal system, the current picture of how these cells communicate with the associated epithelial layer remains unclear. To describe the relevant cell populations in an unbiased manner, we carried out a single-cell transcriptome analysis of the adult murine colon, producing a high-quality atlas of matched colonic epithelium and mesenchyme. We identify two crypt-associated colonic fibroblast populations that are demarcated by different strengths of platelet-derived growth factor receptor A (Pdgfra) expression. Crypt-bottom fibroblasts (CBFs), close to the intestinal stem cells, express low levels of Pdgfra and secrete canonical Wnt ligands, Wnt potentiators, and bone morphogenetic protein (Bmp) inhibitors. Crypt-top fibroblasts (CTFs) exhibit high Pdgfra levels and secrete noncanonical Wnts and Bmp ligands. While the Pdgfralow cells maintain intestinal stem cell proliferation, the Pdgfrahigh cells induce differentiation of the epithelial cells. Our findings enhance our understanding of the crosstalk between various colonic epithelial cells and their associated mesenchymal signaling hubs along the crypt axis-placing differential Pdgfra expression levels in the spotlight of intestinal fibroblast identity.


Assuntos
Colo/metabolismo , Fibroblastos/classificação , Fibroblastos/metabolismo , Animais , Proteínas Morfogenéticas Ósseas/metabolismo , Diferenciação Celular/fisiologia , Proliferação de Células/fisiologia , Colo/fisiologia , Células Epiteliais/metabolismo , Feminino , Perfilação da Expressão Gênica/métodos , Homeostase , Mucosa Intestinal/metabolismo , Intestinos/fisiologia , Mesoderma/citologia , Mesoderma/fisiologia , Camundongos , Camundongos Endogâmicos C57BL , Transdução de Sinais , Análise de Célula Única/métodos , Células-Tronco/citologia , Transcriptoma/genética
11.
Nat Cell Biol ; 22(9): 1033-1041, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32884148

RESUMO

Intestinal stem and progenitor cells replicate and differentiate in distinct compartments, influenced by Wnt, BMP, and other subepithelial cues. The cellular sources of these signals were long obscure because intestinal mesenchyme was insufficiently characterised. In this Review, we discuss how recent mRNA profiles of mouse and human intestinal submucosa, coupled with fine-resolution microscopy and gene and cell disruptions, reveal a coherent picture of an organised tissue carrying cells with distinct molecular properties and functions.


Assuntos
Mucosa Intestinal/fisiologia , Nicho de Células-Tronco/fisiologia , Animais , Humanos , Mesoderma/fisiologia , RNA Mensageiro/genética , Proteínas Wnt/genética
12.
Curr Biol ; 30(16): 3141-3153.e5, 2020 08 17.
Artigo em Inglês | MEDLINE | ID: mdl-32619487

RESUMO

Most fibroblast growth factors (FGFs) function as receptor ligands through their conserved FGF domain, but sequences outside this domain vary and are not well studied. This core domain of 120 amino acids (aa) is flanked in all FGFs by highly divergent amino-terminal and carboxy-terminal sequences of variable length. Drosophila has fewer FGF genes, with only three identified to date, pyramus (pyr), thisbe (ths), and branchless (bnl), and all three encoding relatively large FGF proteins (∼80 kDa). We hypothesized that the longer FGF proteins present in Drosophila and other organisms may relate to an ancestral form, in which multiple functions or regulatory properties are present within a single polypeptide. Here, we focused analysis on Pyr, finding that it harbors a transmembrane domain (TMD) and extended C-terminal intracellular domain containing a degron. The intracellular portion limits Pyr levels, whereas the TMD promotes spatial precision in the paracrine activation of Heartless FGF receptor. Additionally, degron deletion mutants that upregulate Pyr exhibit cell polarity defects that lead to invagination defects at gastrulation, demonstrating a previously uncharacterized cell-autonomous role. In summary, our data show that Pyr is the first demonstrated transmembrane FGF, that it has both extracellular and intracellular functions, and that spatial distribution and levels of this particular FGF protein are tightly regulated. Our results suggest that other FGFs may be membrane tethered or multifunctional like Pyr.


Assuntos
Membrana Celular/metabolismo , Polaridade Celular , Proteínas de Drosophila/metabolismo , Drosophila melanogaster/metabolismo , Embrião não Mamífero/fisiologia , Fatores de Crescimento de Fibroblastos/metabolismo , Mesoderma/fisiologia , Animais , Movimento Celular , Proteínas de Drosophila/genética , Drosophila melanogaster/genética , Embrião não Mamífero/citologia , Feminino , Fatores de Crescimento de Fibroblastos/genética , Gastrulação , Masculino , Mesoderma/citologia , Transdução de Sinais
13.
Genetics ; 215(2): 297-322, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32487692

RESUMO

Mesoderm migration in the Drosophila embryo is a highly conserved, complex process that is required for the formation of specialized tissues and organs, including the somatic and visceral musculature. In this FlyBook chapter, we will compare and contrast the specification and migration of cells originating from the trunk and caudal mesoderm. Both cell types engage in collective migrations that enable cells to achieve new positions within developing embryos and form distinct tissues. To start, we will discuss specification and early morphogenetic movements of the presumptive mesoderm, then focus on the coordinate movements of the two subtypes trunk mesoderm and caudal visceral mesoderm, ending with a comparison of these processes including general insights gained through study.


Assuntos
Movimento Celular , Proteínas de Drosophila/metabolismo , Drosophila/fisiologia , Embrião não Mamífero/citologia , Regulação da Expressão Gênica no Desenvolvimento , Mesoderma/fisiologia , Mioblastos/citologia , Animais , Drosophila/embriologia , Proteínas de Drosophila/genética , Embrião não Mamífero/fisiologia , Mesoderma/embriologia , Mioblastos/fisiologia
14.
Dev Biol ; 463(1): 39-52, 2020 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-32360631

RESUMO

Netrin is a remarkably conserved midline landmark, serving as a chemotactic factor that organizes the bilateral neural architecture in the post-gastrula bilaterian embryos. Netrin signal also guides cell migration in many other neural and non-neural organogenesis events in later developmental stages but has never been found to participate in gastrulation - the earliest cell migration in metazoan embryogenesis. Here, we found that the netrin signaling molecules and their receptors are expressed during gastrulation of the leech Helobdella. Intriguingly, Hau-netrin-1 was expressed in the N lineage, which gives rise in part to the ventral midline of ectoderm, at the onset of gastrulation. We demonstrated that the N lineage is required for the entrance of mesoderm into the germinal band and that misexpression of Hau-netrin-1 in early gastrulation prevented mesoderm from entering the germinal band. Together, these results suggested that Hau-netrin-1 secreted by the N lineage guides mesoderm migration during germinal band assembly. Furthermore, ectopic expression of Hau-netrin-1 after the completion of germinal band assembly disrupted the epibolic migration of the germinal bands in a later stage of gastrulation. Thus, Hau-netrin-1 is likely involved in two distinct events in sequential stages of leech gastrulation: the assembly of germinal bands in early gastrulation and their epibolic migration in mid-gastrulation. Given that the leech netrin is expressed in the precursor cells of the ventral midline during gastrulation, we propose that a heterochronic change from the midline netrin expression had taken place in the evolution of a novel mode of gastrulation in the directly developing leech embryos.


Assuntos
Mesoderma/metabolismo , Netrinas/metabolismo , Animais , Movimento Celular/fisiologia , Ectoderma/metabolismo , Ectoderma/fisiologia , Gástrula , Gastrulação/fisiologia , Sanguessugas/metabolismo , Mesoderma/fisiologia , Morfogênese , Sistema Nervoso , Netrinas/fisiologia
15.
Elife ; 92020 03 31.
Artigo em Inglês | MEDLINE | ID: mdl-32228864

RESUMO

An extracellular matrix of Fibronectin adheres the neural tube to the two flanking columns of paraxial mesoderm and is required for normal vertebrate development. Here, we find that the bilaterally symmetric interfaces between the zebrafish neural tube and paraxial mesoderm function as optimally engineered adhesive lap joints with rounded edges, graded Fibronectin 'adhesive' and an arced adhesive spew filet. Fibronectin is a 'smart adhesive' that remodels to the lateral edges of the neural tube-paraxial mesoderm interfaces where shear stress is highest. Fibronectin remodeling is mechanically responsive to contralateral variation morphogenesis, and Fibronectin-mediated inter-tissue adhesion is required for bilaterally symmetric morphogenesis of the paraxial mesoderm. Strikingly, however, perturbation of the Fibronectin matrix rescues the neural tube convergence defect of cadherin 2 mutants. Therefore, Fibronectin-mediated inter-tissue adhesion dynamically coordinates bilaterally symmetric morphogenesis of the vertebrate trunk but predisposes the neural tube to convergence defects that lead to spina bifida.


Assuntos
Fibronectinas/fisiologia , Mesoderma/fisiologia , Morfogênese , Tubo Neural/crescimento & desenvolvimento , Coluna Vertebral/crescimento & desenvolvimento , Adesivos , Animais , Matriz Extracelular/fisiologia , Feminino , Humanos , Masculino , Coluna Vertebral/anatomia & histologia , Peixe-Zebra/fisiologia
16.
Curr Top Dev Biol ; 137: 391-431, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32143751

RESUMO

Gastrulation is the process whereby cells exit pluripotency and concomitantly acquire and pattern distinct cell fates. This is driven by the convergence of WNT, BMP, Nodal and FGF signals, which are tightly spatially and temporally controlled, resulting in regional and stage-specific signaling environments. The combination, level and duration of signals that a cell is exposed to, according its position within the embryo and the developmental time window, dictates the fate it will adopt. The key pathways driving gastrulation exhibit complex interactions, which are difficult to disentangle in vivo due to the complexity of manipulating multiple signals in parallel with high spatiotemporal resolution. Thus, our current understanding of the signaling dynamics regulating gastrulation is limited. In vitro stem cell models have been established, which undergo organized cellular differentiation and patterning. These provide amenable, simplified, deconstructed and scalable models of gastrulation. While the foundation of our understanding of gastrulation stems from experiments in embryos, in vitro systems are now beginning to reveal the intricate details of signaling regulation. Here we discuss the current state of knowledge of the role, regulation and dynamic interaction of signaling pathways that drive mouse gastrulation.


Assuntos
Padronização Corporal , Diferenciação Celular , Embrião de Mamíferos/fisiologia , Gastrulação , Regulação da Expressão Gênica no Desenvolvimento , Mesoderma/fisiologia , Animais , Embrião de Mamíferos/citologia , Técnicas In Vitro , Mesoderma/citologia , Camundongos , Transdução de Sinais
17.
Sci Rep ; 10(1): 4425, 2020 03 10.
Artigo em Inglês | MEDLINE | ID: mdl-32157178

RESUMO

Type 2 immune cells and eosinophils are transiently present in the lung tissue not only in pathology (allergic disease, parasite expulsion) but also during normal postnatal development. However, the lung developmental processes underlying airway recruitment of eosinophils after birth remain unexplored. We determined that in mice, mature eosinophils are transiently recruited to the lung during postnatal days 3-14, which specifically corresponds to the primary septation/alveolarization phase of lung development. Developmental eosinophils peaked during P10-14 and exhibited Siglec-Fmed/highCD11c-/low phenotypes, similar to allergic asthma models. By interrogating the lung transcriptome and proteome during peak eosinophil recruitment in postnatal development, we identified markers that functionally capture the establishment of the mesenchymal-epithelial interface (Nes, Smo, Wnt5a, Nog) and the deposition of the provisional extracellular matrix (ECM) (Tnc, Postn, Spon2, Thbs2) as a key lung morphogenetic event associating with eosinophils. Tenascin-C (TNC) was identified as one of the key ECM markers in the lung epithelial-mesenchymal interface both at the RNA and protein levels, consistently associating with eosinophils in development and disease in mice and humans. As determined by RNA-seq analysis, naïve murine eosinophils cultured with ECM enriched in TNC significantly induced expression of Siglec-F, CD11c, eosinophil peroxidase, and other markers typical for activated eosinophils in development and allergic inflammatory responses. TNC knockout mice had an altered eosinophil recruitment profile in development. Collectively, our results indicate that lung morphogenetic processes associated with heightened Type 2 immunity are not merely a tissue "background" but specifically guide immune cells both in development and pathology.


Assuntos
Eosinófilos/fisiologia , Matriz Extracelular/fisiologia , Regulação da Expressão Gênica , Pulmão/crescimento & desenvolvimento , Pulmão/imunologia , Mesoderma/fisiologia , Animais , Eosinófilos/citologia , Perfilação da Expressão Gênica , Pulmão/metabolismo , Mesoderma/citologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout
18.
Nat Commun ; 11(1): 665, 2020 01 31.
Artigo em Inglês | MEDLINE | ID: mdl-32005801

RESUMO

Injury, surgery, and disease often disrupt tissues and it is the process of regeneration that aids the restoration of architecture and function. Regeneration can occur through multiple strategies including stem cell expansion, transdifferentiation, or proliferation of differentiated cells. We have identified a case of regeneration in Xenopus embryonic aggregates that restores a mucociliated epithelium from mesenchymal cells. Following disruption of embryonic tissue architecture and assembly of a compact mesenchymal aggregate, regeneration first restores an epithelium, transitioning from mesenchymal cells at the surface of the aggregate. Cells establish apico-basal polarity within 5 hours and a mucociliated epithelium within 24 hours. Regeneration coincides with nuclear translocation of the putative mechanotransducer YAP1 and a sharp increase in aggregate stiffness, and regeneration can be controlled by altering stiffness. We propose that regeneration of a mucociliated epithelium occurs in response to biophysical cues sensed by newly exposed cells on the surface of a disrupted mesenchymal tissue.


Assuntos
Epiderme/química , Epiderme/fisiologia , Xenopus laevis/embriologia , Animais , Fenômenos Biomecânicos , Epiderme/embriologia , Epitélio/química , Epitélio/embriologia , Epitélio/fisiologia , Mesoderma/química , Mesoderma/embriologia , Mesoderma/fisiologia , Regeneração , Xenopus laevis/fisiologia
19.
Development ; 147(4)2020 02 26.
Artigo em Inglês | MEDLINE | ID: mdl-32001441

RESUMO

In several model animals, the earliest phases of embryogenesis are regulated by lineage-specific genes, such as Drosophila bicoid Sea urchin (echinoid) embryogenesis is initiated by zygotic expression of pmar1, a paired-class homeobox gene that has been considered to be present only in the lineage of modern urchins (euechinoids). In euechinoids, Pmar1 promotes endomesoderm specification by repressing the hairy and enhancer of split C (hesC) gene. Here, we have identified the basal echinoid (cidaroid) pmar1 gene, which also promotes endomesoderm specification but not by repressing hesC A further search for related genes demonstrated that other echinoderms have pmar1-related genes named phb Functional analyses of starfish Phb proteins indicated that, similar to cidaroid Pmar1, they promote activation of endomesoderm regulatory gene orthologs via an unknown repressor that is not HesC. Based on these results, we propose that Pmar1 may have recapitulated the regulatory function of Phb during the early diversification of echinoids and that the additional repressor HesC was placed under the control of Pmar1 in the euechinoid lineage. This case provides an exceptional model for understanding how early developmental processes diverge.


Assuntos
Endoderma/fisiologia , Proteínas de Homeodomínio/fisiologia , Mesoderma/fisiologia , Ouriços-do-Mar/embriologia , Animais , Diferenciação Celular , Linhagem da Célula , Desenvolvimento Embrionário , Perfilação da Expressão Gênica , Regulação da Expressão Gênica no Desenvolvimento , Redes Reguladoras de Genes , Larva/fisiologia , Fenótipo , Filogenia , Receptores Notch/fisiologia , Ouriços-do-Mar/genética
20.
Proc Natl Acad Sci U S A ; 117(9): 4781-4791, 2020 03 03.
Artigo em Inglês | MEDLINE | ID: mdl-32071242

RESUMO

Numerous hypotheses invoke tissue stiffness as a key parameter that regulates morphogenesis and disease progression. However, current methods are insufficient to test hypotheses that concern physical properties deep in living tissues. Here we introduce, validate, and apply a magnetic device that generates a uniform magnetic field gradient within a space that is sufficient to accommodate an organ-stage mouse embryo under live conditions. The method allows rapid, nontoxic measurement of the three-dimensional (3D) spatial distribution of viscoelastic properties within mesenchyme and epithelia. Using the device, we identify an anteriorly biased mesodermal stiffness gradient along which cells move to shape the early limb bud. The stiffness gradient corresponds to a Wnt5a-dependent domain of fibronectin expression, raising the possibility that durotaxis underlies cell movements. Three-dimensional stiffness mapping enables the generation of hypotheses and potentially the rigorous testing of mechanisms of development and disease.


Assuntos
Imageamento Tridimensional/métodos , Botões de Extremidades/diagnóstico por imagem , Botões de Extremidades/fisiologia , Mesoderma/fisiologia , Camundongos/embriologia , Animais , Movimento Celular/fisiologia , Epitélio , Fibronectinas , Imageamento Tridimensional/instrumentação , Morfogênese , Proteína Wnt-5a
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