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Development (Cambridge, England) 1988Craniofacial mesenchyme is composed of three mesodermal populations - prechordal plate, lateral mesoderm and paraxial mesoderm, which includes the segmented occipital... (Review)
Review
Craniofacial mesenchyme is composed of three mesodermal populations - prechordal plate, lateral mesoderm and paraxial mesoderm, which includes the segmented occipital somites and the incompletely segmented somitomeres - and the neural crest. This paper outlines the fates of each of these, as determined using quail-chick chimaeras, and presents similarities and differences between these cephalic populations and their counterparts in the trunk. Prechordal and paraxial mesodermal populations are the sources of all voluntary muscles of the head. The latter also provides most of the connective precursors of the calvaria, occipital, otic-parietal and basisphenoid tissues. Lateral mesoderm is the source of peripharyngeal connective tissues; the most rostral skeletal tissues it forms are the laryngeal and tracheal cartilages. When migrating neural crest cells encounter segmented paraxial mesoderm (occipital and trunk somites), most move into the region between the dermamyotome and sclerotome in the cranial half of each somite. In contrast, most cephalic crest cells migrate superficial to somitomeres. There is, however, a small subpopulation of the head crest that invades somitomeric mesoderm. These cells subsequently segregate presumptive myogenic precursors of visceral arch voluntary muscles from underlying mesenchyme. In the neurula-stage avian embryo, all paraxial and lateral mesodermal populations contain precursors of vascular endothelial cells, which can be detected in chimaeric embryos using anti-quail endothelial anti-bodies. Some of these angioblasts differentiate in situ, contributing directly to pre-existing vessels or forming isolated, nonpatent, cords that subsequently vesiculate and fuse with nearby vessels. Many angioblasts migrate in all directions, invading embryonic mesenchymal and epithelial tissues and participating in new blood vessel formation in distant sites. The interactions leading to proper spatial patterning of craniofacial skeletal, muscular, vascular and peripheral neural tissues has been studied by performing heterotopic transplants of each of these mesodermal and neural crest populations. The results consistently indicate that connective tissue precursors, regardless of their origin, contain spatial information used by the precursors of muscles and blood vessels and by outgrowing peripheral nerves. Some of these connective tissue precursors (e.g. the neural crest, paraxial mesoderm) acquire their spatial programming while in association with the central nervous system or developing sensory epithelia (e.g. otic, optic, nasal epithelia).
Topics: Animals; Chick Embryo; Face; Mesoderm; Skull
PubMed: 3074905
DOI: 10.1242/dev.103.Supplement.121 -
APMIS : Acta Pathologica,... Apr 1993This review focuses on epithelium-mesenchymal transitions (EMT), defined as dynamic cell restructurations changing the epithelial state of differentiation into a... (Review)
Review
This review focuses on epithelium-mesenchymal transitions (EMT), defined as dynamic cell restructurations changing the epithelial state of differentiation into a mesenchymal phenotype. These transitions, known to occur during embryogenesis are also involved during some pathological events of adult life, such as wound repair and metastasis of cancer cells. Numerous studies of embryonic EMTs, found during some morphogenetic processes, have stressed the importance of intercellular and cell-matrix adhesive interactions as key elements regulating cell dissociation and acquisition of cell motility. On the other hand, in vitro studies indicate that growth factors, growth-factor related molecules and extracellular matrix components are involved in initiation of EMT. Therefore, the cellular targets of EMT-inducing molecules are likely to include molecules participating in cell adhesion systems.
Topics: Amphibians; Animals; Cell Adhesion; Connective Tissue; Connective Tissue Cells; Epithelial Cells; Epithelium; Humans; Kidney; Mammals; Mesoderm; Morphogenesis
PubMed: 8323734
DOI: 10.1111/j.1699-0463.1993.tb00109.x -
PLoS Biology Sep 2011The developing pancreatic epithelium gives rise to all endocrine and exocrine cells of the mature organ. During organogenesis, the epithelial cells receive essential...
The developing pancreatic epithelium gives rise to all endocrine and exocrine cells of the mature organ. During organogenesis, the epithelial cells receive essential signals from the overlying mesenchyme. Previous studies, focusing on ex vivo tissue explants or complete knockout mice, have identified an important role for the mesenchyme in regulating the expansion of progenitor cells in the early pancreas epithelium. However, due to the lack of genetic tools directing expression specifically to the mesenchyme, the potential roles of this supporting tissue in vivo, especially in guiding later stages of pancreas organogenesis, have not been elucidated. We employed transgenic tools and fetal surgical techniques to ablate mesenchyme via Cre-mediated mesenchymal expression of Diphtheria Toxin (DT) at the onset of pancreas formation, and at later developmental stages via in utero injection of DT into transgenic mice expressing the Diphtheria Toxin receptor (DTR) in this tissue. Our results demonstrate that mesenchymal cells regulate pancreatic growth and branching at both early and late developmental stages by supporting proliferation of precursors and differentiated cells, respectively. Interestingly, while cell differentiation was not affected, the expansion of both the endocrine and exocrine compartments was equally impaired. To further elucidate signals required for mesenchymal cell function, we eliminated β-catenin signaling and determined that it is a critical pathway in regulating mesenchyme survival and growth. Our study presents the first in vivo evidence that the embryonic mesenchyme provides critical signals to the epithelium throughout pancreas organogenesis. The findings are novel and relevant as they indicate a critical role for the mesenchyme during late expansion of endocrine and exocrine compartments. In addition, our results provide a molecular mechanism for mesenchymal expansion and survival by identifying β-catenin signaling as an essential mediator of this process. These results have implications for developing strategies to expand pancreas progenitors and β-cells for clinical transplantation.
Topics: Animals; Diphtheria Toxin; Embryo, Mammalian; Epithelium; Gene Expression Regulation, Developmental; Mesoderm; Mice; Mice, Knockout; Organogenesis; Pancreas
PubMed: 21909240
DOI: 10.1371/journal.pbio.1001143 -
Developmental Biology Oct 2021In vertebrate embryos, the kidney primordium metanephros is formed from two distinct cell lineages, Wolffian duct and metanephric mesenchyme, which were classically...
In vertebrate embryos, the kidney primordium metanephros is formed from two distinct cell lineages, Wolffian duct and metanephric mesenchyme, which were classically grouped as intermediate mesoderm. Whereas the reciprocal interactions between these two cell populations in kidney development have been studied extensively, the mechanisms generating them remain elusive. Here, we show that the mouse cell lineage that forms nephric mesenchyme develops as a subpopulation of Tbx6-expressing mesodermal precursor derivatives of neuro-mesodermal progenitors (NMPs) under the condition of bone morphogenetic protein (BMP)-signal-dependent Osr1 expression. The Osr1-expressing nephric mesenchyme precursors were confirmed as descendants of NMPs because they were labeled by Sox2 N1 enhancer-EGFP. In Tbx6 mutant embryos, nephric mesenchyme changed its fate into neural tissues, which reflected its NMP origin. In Osr1 mutant embryos, the specific region of the Tbx6-expressing mesoderm precursor, which normally expresses Osr1 and develops into the nephric mesenchyme, instead expressed the somite marker FoxC2. BMP signaling activated Osr1 expression in a region of TBX6-expressing mesoderm and elicited nephric mesenchyme development. This study suggested a new model of cell lineage segregation during gastrulation.
Topics: Animals; Bone Morphogenetic Proteins; Cell Lineage; Forkhead Transcription Factors; Gastrulation; Kidney; Mesenchymal Stem Cells; Mesoderm; Mice; Neural Stem Cells; Organogenesis; Signal Transduction; Somites; Stem Cells; T-Box Domain Proteins; Transcription Factors
PubMed: 34256037
DOI: 10.1016/j.ydbio.2021.07.006 -
Cancer Surveys 1991Since adult epithelial cells from the urogenital tract are unquestionably capable of expressing alternative phenotypes when induced by embryonic or neonatal mesenchymes,... (Review)
Review
Since adult epithelial cells from the urogenital tract are unquestionably capable of expressing alternative phenotypes when induced by embryonic or neonatal mesenchymes, we examined the effect of certain inductive mesenchymes on the differentiation and growth of the DT by growing 0.5 mm3 fragments of the DT in association with mesenchyme from various embryonic and neonatal rat organ rudiments. Whereas grafts of DT alone contained narrow ducts lined with undifferentiated epithelial cells characteristic of the DT, the DT derived epithelium of UGM + DT, SVM + DT or BUG-M + DT recombinations differentiated into tall columnar secretory epithelial cells organized into large cystic ducts. These mesenchyme induced changes in histodifferentiation of the DT cells were coupled to a loss of tumorigenesis since the mesenchyme induced highly differentiated DT cells never formed tumours. This reduction in growth rate and loss in tumorigenesis of mesenchyme induced DT epithelial cells was accompanied by a reduction in [3H]thymidine labelling index and the expression of a secretory phenotype as demonstrated by both light microscopy and electron microscopy. These findings demonstrate that the connective tissue environment can have profound regulative effects on both normal and neoplastic epithelial cells.
Topics: Animals; Cell Communication; Cell Differentiation; Cell Division; Cell Transformation, Neoplastic; Epithelial Cells; Humans; Male; Mesoderm; Prostatic Neoplasms; Rats; Urogenital System
PubMed: 1841758
DOI: No ID Found -
Birth Defects Research. Part A,... Jan 2012Bronchopulmonary dysplasia (BPD) is a chronic lung disease in infants born extremely preterm, typically before 28 weeks' gestation, characterized by a prolonged need for... (Review)
Review
Bronchopulmonary dysplasia (BPD) is a chronic lung disease in infants born extremely preterm, typically before 28 weeks' gestation, characterized by a prolonged need for supplemental oxygen or positive pressure ventilation beyond 36 weeks postmenstrual age. The limited number of autopsy samples available from infants with BPD in the postsurfactant era has revealed a reduced capacity for gas exchange resulting from simplification of the distal lung structure with fewer, larger alveoli because of a failure of normal lung alveolar septation and pulmonary microvascular development. The mechanisms responsible for alveolar simplification in BPD have not been fully elucidated, but mounting evidence suggests that aberrations in the cross-talk between growth factors of the lung mesenchyme and distal airspace epithelium have a key role. Animal models that recapitulate the human condition have expanded our knowledge of the pathology of BPD and have identified candidate matrix components and growth factors in the developing lung that are disrupted by conditions that predispose infants to BPD and interfere with normal vascular and alveolar morphogenesis. This review focuses on the deviations from normal lung development that define the pathophysiology of BPD and summarizes the various candidate mesenchyme-associated proteins and growth factors that have been identified as being disrupted in animal models of BPD. Finally, future areas of research to identify novel targets affected in arrested lung development and recovery are discussed.
Topics: Animals; Bronchopulmonary Dysplasia; Humans; Infant, Newborn; Infant, Premature; Infant, Premature, Diseases; Intercellular Signaling Peptides and Proteins; Lung; Mesoderm; Mice; Proteins; Signal Transduction
PubMed: 22125178
DOI: 10.1002/bdra.22869 -
Developmental Biology May 2019The embryonic origin of pericytes is heterogeneous, both between and within organs. While pericytes of coelomic organs were proposed to differentiate from the...
The embryonic origin of pericytes is heterogeneous, both between and within organs. While pericytes of coelomic organs were proposed to differentiate from the mesothelium, a single-layer squamous epithelium, the embryonic origin of pancreatic pericytes has yet to be reported. Here, we show that adult pancreatic pericytes originate from the embryonic pancreatic mesenchyme. Our analysis indicates that pericytes of the adult mouse pancreas originate from cells expressing the transcription factor Nkx3.2. In the embryonic pancreas, Nkx3.2-expressing cells constitute the multilayered mesenchyme, which surrounds the pancreatic epithelium and supports multiple events in its development. Thus, we traced the fate of the pancreatic mesenchyme. Our analysis reveals that pancreatic mesenchymal cells acquire various pericyte characteristics, including gene expression, typical morphology, and periendothelial location, during embryogenesis. Importantly, we show that the vast majority of pancreatic mesenchymal cells differentiate into pericytes already at embryonic day 13.5 and progressively acquires a more mature pericyte phenotype during later stages of pancreas organogenesis. Thus, our study indicates the embryonic pancreatic mesenchyme as the primary origin to adult pancreatic pericytes. As pericytes of other coelomic organs were suggested to differentiate from the mesothelium, our findings point to a distinct origin of these cells in the pancreas. Thus, our study proposes a complex ontogeny of pericytes of coelomic organs.
Topics: Animals; Biomarkers; Embryonic Development; Endothelial Cells; Gene Expression Regulation, Developmental; Homeodomain Proteins; Mesoderm; Mice; Pancreas; Pericytes; Receptor, Platelet-Derived Growth Factor beta; Transcription Factors
PubMed: 30771302
DOI: 10.1016/j.ydbio.2019.01.020 -
Developmental Biology (New York, N.Y. :... 1986
Review
Topics: Animals; Cell Communication; Cell Movement; Epithelial Cells; Epithelium; Mesoderm; Morphogenesis; Sea Urchins
PubMed: 3078121
DOI: 10.1007/978-1-4613-2141-5_10 -
Microscopy Research and Technique Oct 1998Hyaline cartilage is archetypic for the appendicular skeleton and the vertebral column. It arises from pluirpotential mesenchymal ancestor cells that remain... (Review)
Review
Hyaline cartilage is archetypic for the appendicular skeleton and the vertebral column. It arises from pluirpotential mesenchymal ancestor cells that remain morphologically undifferentiated prior to a localized cell aggregation in specific regions destined to undergo chondrogenesis. The critical ultrastructural studies of limb bud mesenchymal differentiation prior to, during, and after aggregation were largely completed during the 1970s. These studies accurately and reproducibly described the changes in the cells and matrix with reference to the developmental stages of the embryonic chick and mouse. Collectively, the morphological literature concerning mouse and chick chondrogenesis is in fundamental agreement on the timing and sequence of cell and matrix changes. The morphological observations are foundational and are now extensively correlated with the molecular events of cartilage differentiation.
Topics: Animals; Cartilage; Cell Differentiation; Chondrogenesis; Humans; Mesoderm
PubMed: 9822996
DOI: 10.1002/(SICI)1097-0029(19981015)43:2<91::AID-JEMT2>3.0.CO;2-3 -
Differentiation; Research in Biological... 2016This paper reviews the importance of mesenchymal-epithelial interactions in development and gives detailed technical protocols for investigating these interactions.... (Review)
Review
This paper reviews the importance of mesenchymal-epithelial interactions in development and gives detailed technical protocols for investigating these interactions. Successful analysis of mesenchymal-epithelial interactions requires knowing the ages in which embryonic, neonatal and adult organs can be separated into mesenchymal and epithelial tissues. Methods for separation of mesenchymal and epithelial tissues and preparation of tissue recombinants are described.
Topics: Animals; Cell Differentiation; Cellular Reprogramming; Epithelium; Humans; Mesoderm; Mice; Organogenesis
PubMed: 26610327
DOI: 10.1016/j.diff.2015.10.006