An ultrastructural and morphometric analysis of an in vivo contact guidance system

Development ◽  
1987 ◽  
Vol 101 (2) ◽  
pp. 363-381
Author(s):  
A. Wood ◽  
P. Thorogood
Keyword(s):  
Cell Migration ◽  
Morphometric Analysis ◽  
Mesenchymal Cell ◽  
Mesenchymal Cells ◽  
Contact Guidance ◽  
Cell Phenotype ◽  
Cell Processes ◽  
Computer Based ◽  
The Mean

The pectoral fin bud of the developing teleost embryo contains a highly ordered extracellular matrix of collagenous fibrils, called ‘actinotrichia’. During invasion of the fin fold, mesenchymal cells, migrating distally from the base of the fin, become contact aligned by the actinotrichial fibrils. Behavioural aspects of this response have previously been studied using Nomarski differential interference contrast microscopy and time-lapse video recording (Wood & Thorogood, 1984). Here we present an ultrastructural description of these cells and their matrix associations and a computer- based morphometric analysis of selected parameters within the migration substratum, relevant to this in vivo ‘contact guidance’ phenomenon. The study shows that a differentiated and aligned matrix of actinotrichial fibrils can be detected before invasion of the fin fold, at levels up to 40μm distal to the advancing mesenchymal cell margin. Subsequently, during invasion of the fin fold, aligned mesenchymal cells and processes are almost exclusively associated with actinotrichia and not the intervening surface of the epithelial basal lamina. However, aligned cell processes appear to avoid the smaller actinotrichia and at late stages of development 87á0% of actinotrichia without cell process contacts are distributed at the lower end of the size range. Study of cell ultrastructure revealed a complete absence of cytoskeletal organization within this mesenchymal cell population, although cytoskeletal components are clearly visible in adjacent epithelia. The computer-based morphometric survey of the migration substratum has shown a gradual but progressive increase in the mean diameter of actinotrichia at a level at which distal cell processes are first detectable in sections of fins. However, at similar levels over the same period the mean value for interactinotrichial spacings remained virtually constant. These results suggest that the spacing between actinotrichia is not significant in contributing to progressive changes in mesenchymal cell phenotype, but that the actinotrichia themselves are strongly implicated in providing the guidance cues to direct cell migration within the developing fin and the initiation of cell migration. These findings are discussed in the general context of cell movement and contact guidance both in vivo and in vitro.

Acetylcholinesterase (AChE) and pseudocholinesterase (BuChE) activity distribution pattern in early developing chick limbs

Development ◽  
1985 ◽  
Vol 86 (1) ◽  
pp. 89-108
Author(s):  
Carla Falugi ◽  
Margherita Raineri
Keyword(s):  
Plasma Membrane ◽  
Basal Lamina ◽  
Ache Activity ◽  
Quantitative Methods ◽  
Mesenchymal Cell ◽  
Mesenchymal Cells ◽  
Regional Localization ◽  
Stage Of Development ◽  
Limb Morphogenesis ◽  
Cell Processes

The distribution of acetylcholinesterase (AChE) and pseudocholinesterase (BuChE) activities was studied by histochemical, quantitative and electrophoretical methods during the early development of chick limbs, from stage 16 to stage 32 H.H. (Hamburger & Hamilton, 1951). By quantitative methods, true AChE activity was found, and increased about threefold during the developmental period, together with a smaller amount of BuChE which increased more rapidly in comparison with the AChE activity from stage 25 to 32 H.H. Cholinesterase activity was histochemically localized mainly in interacting tissues, such as the ectoderm (including the apical ectodermal ridge) and the underlying mesenchyme. True AChE was histochemically localized around the nuclei and on the plasma membrane of ectodermal (including AER) and mesenchymal cells, and at the plasma membrane of mesenchymal cell processes reaching the basal lamina between the ectoderm and the mesenchyme. AChE together with BuChE activity was found in the basal lamina between the ectoderm and the mesenchyme, in underlying mesenchymal cells and in deeper mesenchymal cells, especially during their transformation into unexpressed chondrocytes. During limb morphogenesis, the cellular and regional localization of the enzyme activities showed variations depending on the stage of development and on the occurrence of interactions. The possibility of morphogenetic functions of the enzyme is discussed.

Fibrogenesis IV. Fibrosis and inflammatory bowel disease: cellular mediators and animal models

2000 ◽  
Vol 279 (4) ◽  
pp. G653-G659 ◽  
Author(s):  
Jolanta B. Pucilowska ◽  
Kristen L. Williams ◽  
P. Kay Lund
Keyword(s):  
Sulfonic Acid ◽  
Genetic Manipulation ◽  
Mesenchymal Cell ◽  
Mesenchymal Cells ◽  
Acute Injury ◽  
Ethanol Administration ◽  
Cell Phenotype ◽  
Trinitrobenzene Sulfonic Acid ◽  
Intestinal Fibrosis ◽  
Cellular Mediators

The cellular mediators of intestinal fibrosis and the relationship between fibrosis and normal repair are not understood. Identification of the types of intestinal mesenchymal cells that produce collagen during normal healing and fibrosis is vital for elucidating the answers to these questions. Acute injury may cause normal mesenchymal cells to convert to a fibrogenic phenotype that is not maintained during normal healing but may lead to fibrosis when inappropriately sustained. Proliferation of normal or fibrogenic mesenchymal cells may lead to muscularis overgrowth associated with fibrosis. The presence of increased numbers of vimentin-positive cells within fibrotic, hypertrophied muscularis in Crohn's disease suggests that changes in mesenchymal cell phenotype and number may indeed be associated with fibrosis. Fibrosis is induced in rats by peptidoglycan polysaccharides or trinitrobenzene sulfonic acid-ethanol administration, but inducing fibrosis in mice has been technically challenging. The development of current mouse models of colitis, such as dextran sodium sulfate or trinitrobenzene sulfonic acid-ethanol administration, into models of fibrosis will allow us to use genetic manipulation to study molecular mediators of fibrosis.

scholarly journals Different translation dynamics of β-and γ-actin regulates cell migration

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Pavan Vedula ◽  
Satoshi Kurosaka ◽  
Brittany MacTaggart ◽  
Qin Ni ◽  
Garegin Papoian ◽  
...  
Keyword(s):  
Cell Migration ◽  
Amino Acid ◽  
Single Molecule ◽  
Amino Acid Level ◽  
Focal Adhesions ◽  
Mesenchymal Cell ◽  
Cell Periphery ◽  
Pronounced Difference ◽  
Coding Sequence

β- and γ-cytoplasmic actins are ubiquitously expressed in every cell type and are nearly identical at the amino acid level but play vastly different roles in vivo. Their essential roles in embryogenesis and mesenchymal cell migration critically depend on the nucleotide sequences of their genes, rather than their amino acid sequence, however it is unclear which gene elements underlie this effect. Here we address the specific role of the coding sequence in β- and γ-cytoplasmic actins' intracellular functions, using stable polyclonal populations of immortalized mouse embryonic fibroblasts with exogenously expressed actin isoforms and their 'codon-switched' variants. When targeted to the cell periphery using the β-actin 3′UTR, β-actin and γ-actin have differential effects on cell migration. These effects directly depend on the coding sequence. Single molecule measurements of actin isoform translation, combined with fluorescence recovery after photobleaching, demonstrate a pronounced difference in β- and γ-actins' translation elongation rates in cells, leading to changes in their dynamics at the focal adhesions, impairments in actin bundle formation, and reduced cell anchoring to the substrate during migration. Our results demonstrate that coding sequence-mediated differences in actin translation play a key role in cell migration.

The Spiegelmer Nox-A12, a Novel SDF-1 (CXCL12) Inhibitor, and Its Effects on Chronic Lymphocytic Leukemia (CLL) Cell Migration,

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 3878-3878
Author(s):  
Julia Hoellenriegel ◽  
Dirk Zboralski ◽  
Zeev Estrov ◽  
William G. Wierda ◽  
Michael Keating ◽  
...  
Keyword(s):  
Clinical Trial ◽  
Bone Marrow ◽  
Cell Migration ◽  
Stromal Cells ◽  
Leukemia Cell ◽  
Cell Trafficking ◽  
The Mean ◽  
Cxcr4 Antagonists ◽  
Cell Chemotaxis

Abstract Abstract 3878 NOX-A12 is a PEGylated mirror-image oligonucleotide (a so-called Spiegelmer), that binds the chemokine SDF-1/CXCL12 with high affinity (approx. 200 pM), thereby efficiently inhibiting its activity. CXCL12 is constitutively secreted by bone marrow stromal cells (BMSC) and acts as a homing factor for normal and malignant hematopoietic cells to the marrow. It induces leukemia cell trafficking and homing to tissue mircroenvironments (i.e. the marrow and secondary lymphatic tissues) via CXCR4 receptors that are expressed at high levels on circulating CLL cells. The microenvironments in the bone marrow and secondary lymphoid tissues favor survival and chemotherapy-resistance of CLL cells. Therefore, targeting the CXCR4-CXCL12 axis is an attractive approach for disrupting the protective effects of CXCL12-secreting stromal cells and for sensitizing CLL cells towards subsequent therapy with conventional agents (chemotherapy, antibodies). We investigated the effect of NOX-A12 on CLL chemotaxis towards CXCL12 and CLL cell migration in BMSC co-cultures. To determine the effect of NOX-A12 on CLL cell chemotaxis, we performed chemotaxis assays across polycarbonate transwell inserts towards the chemokine CXCL12 (200 ng/mL, corresponds to 25 nM). CLL cell chemotaxis was significantly reduced in a dose-dependent manner in samples from 12 patients. Even when a very low NOX-A12 concentration of 3 nM was used, the mean (±SEM) number of CLL cells migrating towards CXCL12 decreased from 1556 (±303) to 640 (±211). Higher concentrations of NOX-A12 reduced CLL cell chemotaxis as significant as AMD3100, e.g. NOX-A12 at a concentration of 100 nM reduced the chemotaxis to 340 (±73) and AMD3100 at a concentration of 10 μg/mL (12.6 μM) to 384 (±156) migrated cells, respectively. Moreover, in other leukemia cell types like the T cell leukemic cell line Jurkat as well as the acute lymphoid leukemia (ALL) cell line Nalm-6, which are very sensitive to CXCL12, NOX-A12 mediated inhibition of chemotaxis was observed with a sub-nanomolar IC50. Next we quantified CLL cell pseudoemperipolesis, i.e. spontaneous leukemia cell migration beneath BMSC, which mimics in vivo migration and homing to stromal cells in the tissues. Surprisingly and in contrast to the inhibited chemotaxis, our results showed increased migration of CLL cells beneath BMSC after NOX-A12 treatment. After pre-treatment with 100 nM NOX-A12, the mean (±SEM) number of migrating cells increased from 10382 (±1604) to 12488 (±6965) using R-15C cells, and from 17888 (±2808) to 22677 (±11492) using TSt-4 cells (n=6). In comparison, the CXCR4 antagonists AMD3100 and BKT14O inhibited the migration beneath BMSC significantly. In accordance with these findings, NOX-A12 also promoted pseudoemperipolesis of Jurkat and Nalm-6 cells beneath MS-5 BMSC layers. Interestingly, this NOX-A12-induced migration could be completely inhibited by AMD3100. We hypothesized that this increased migration of CLL cells as well as Jurkat and Nalm-6 cells beneath BMSC might be the result of a stimulating effect of NOX-A12 on CXCL12 release by the stromal cells. Therefore, we investigated the effect of NOX-A12 on the CXCL12 release in three different BMSC lines (MS-5, R15C, and TSt-4). We found that NOX-A12 induced a rapid CXCL12 release into the medium in all three cell lines. The increase of the CXCL12 concentration was approximately sevenfold in MS-5 cells and approximately twofold in R15C and TSt-4 cells. Given the fact that NOX-A12 induces leukocyte- and hemapopoiectic stem cell mobilization in vivo, the enhanced migration of CLL cells in BMSC co-cultures suggests that NOX-A12 has a unique effect on leukemia cell trafficking that is distinct from small molecule (AMD3100) or peptide (BTK140) CXCR4 antagonists. Future dissection in an in vivo CLL model and in a first clinical trial will help us to better define the effect of NOX-A12 on CLL cells migration. In summary, the CXCL12 inhibitor NOX-A12 is a novel, targeted agent for interference with CLL cell migration and homing to CXCL12-secreting stromal cells. Its effects on CLL cell chemotaxis and migration beneath BMSC make NOX-A12 distinct from CXCR4 antagonists. In vivo experiments and ultimately a clinical trial will help defining how effectively NOX-A12 can mobilize and sensitize CLL cells. Disclosures: Zboralski: NOXXON: Employment. Kruschinski:Noxxon Pharma AG: Employment. Burger:NOXXON: Consultancy, Research Funding.

scholarly journals High RhoA activity maintains the undifferentiated mesenchymal cell phenotype, whereas RhoA down-regulation by laminin-2 induces smooth muscle myogenesis

2002 ◽  
Vol 156 (5) ◽  
pp. 893-903 ◽  
Author(s):  
Safedin Beqaj ◽  
Sandhya Jakkaraju ◽  
Raymond R. Mattingly ◽  
Desi Pan ◽  
Lucia Schuger
Keyword(s):  
Smooth Muscle ◽  
Serum Response Factor ◽  
Mesenchymal Cell ◽  
Mesenchymal Cells ◽  
Small Gtpase ◽  
Cell Phenotype ◽  
Rhoa Activity ◽  
Functional Studies ◽  
Undifferentiated Mesenchymal Cell ◽  
Main Components

Round embryonic mesenchymal cells have the potential to differentiate into smooth muscle (SM) cells upon spreading/elongation (Yang, Y., K.C. Palmer, N. Relan, C. Diglio, and L. Schuger. 1998. Development. 125:2621–2629; Yang, Y., N.K. Relan, D.A. Przywara, and L. Schuger. 1999. Development. 126:3027–3033; Yang, Y., S. Beqaj, P. Kemp, I. Ariel, and L. Schuger. 2000. J. Clin. Invest. 106:1321–1330). In the developing lung, this process is stimulated by peribronchial accumulation of laminin (LN)-2 (Relan, N.K., Y. Yang, S. Beqaj, J.H. Miner, and L. Schuger. 1999. J. Cell Biol. 147:1341–1350). Here we show that LN-2 stimulates bronchial myogenesis by down-regulating RhoA activity. Immunohistochemistry, immunoblotting, and reverse transcriptase–PCR indicated that RhoA, a small GTPase signaling protein, is abundant in undifferentiated embryonic mesenchymal cells and that its levels decrease along with SM myogenesis. Functional studies using agonists and antagonists of RhoA activation and dominant positive and negative plasmid constructs demonstrated that high RhoA activity was required to maintain the round undifferentiated mesenchymal cell phenotype. This was in part achieved by restricting the localization of the myogenic transcription factor serum response factor (SRF) mostly to the mesenchymal cell cytoplasm. Upon spreading on LN-2 but not on other main components of the extracellular matrix, the activity and level of RhoA decreased rapidly, resulting in translocation of SRF to the nucleus. Both cell elongation and SRF translocation were prevented by overexpression of dominant positive RhoA. Once the cells underwent SM differentiation, up-regulation of RhoA activity induced rather than inhibited SM gene expression. Therefore, our studies suggest a novel mechanism whereby LN-2 and RhoA modulate SM myogenesis.

Embryonic mesenchymal cells share the potential for smooth muscle differentiation: myogenesis is controlled by the cell's shape

Development ◽  
1999 ◽  
Vol 126 (13) ◽  
pp. 3027-3033 ◽  
Author(s):  
Y. Yang ◽  
N.K. Relan ◽  
D.A. Przywara ◽  
L. Schuger
Keyword(s):  
Smooth Muscle ◽  
Mesenchymal Cell ◽  
Muscle Differentiation ◽  
Mesenchymal Cells ◽  
Membrane Potentials ◽  
Main Role ◽  
Visceral Muscle ◽  
Smooth Muscle Differentiation

Undifferentiated embryonic mesenchymal cells are round/cuboidal in shape. During development, visceral myogenesis is shortly preceded by mesenchymal cell elongation. To determine the role of the cell's shape on smooth muscle development, undifferentiated embryonic mesenchymal cells from intestine (abundant visceral muscle), lung (some visceral muscle) or kidney (no visceral muscle) were plated under conditions that maintained cell rounding or promoted elongation. Regardless of their fate in vivo, all the cells differentiated into smooth muscle upon elongation as indicated by the expression of smooth muscle-specific proteins and the development of membrane potentials of −60 mV and voltage-dependent Ca2+ currents, characteristic of excitable cells. Smooth muscle differentiation occurred within 24 hours and was independent of cell proliferation. Regardless of their fate in vivo, all the round cells remained negative for smooth muscle markers, had membrane potentials of −30 mV and showed no voltage-activated current. These cells, however, differentiated into smooth muscle upon elongation. The role of the cell's shape in controlling smooth muscle differentiation was not overcome by treatment with retinoic acid, TGF-beta1, PDGF BB or epithelial-conditioned medium (all modulators of smooth muscle differentiation). These studies suggest that the mesenchymal cell shape plays a main role in visceral myogenesis.

Mesenchyme-mediated effects of retinoic acid during rat intestinal development

1997 ◽  
Vol 110 (10) ◽  
pp. 1227-1238 ◽  
Author(s):  
M. Plateroti ◽  
J.N. Freund ◽  
C. Leberquier ◽  
M. Kedinger
Keyword(s):  
Retinoic Acid ◽  
Epithelial Cell ◽  
Polyclonal Antibodies ◽  
Mesenchymal Cell ◽  
Mesenchymal Cells ◽  
Cell Polarization ◽  
Cell Interactions ◽  
Intestinal Cell ◽  
Cell Phenotype ◽  
Intestinal Development

In previous experiments we showed that intestinal development was dependent upon epithelial-mesenchymal cell interactions. The aim of this study was to investigate the possible role of retinoic acid (RA), a morphogenetic and differentiating agent, on the gut epithelial-mesenchymal unit. For this purpose we first analyzed the effects of a physiological dose of RA on 14-day fetal rat intestine using short-term organ culture experiments, or long-term grafts under the skin of nude mice. In these conditions, RA accelerated villus outgrowth and epithelial cell differentiation as assessed by the onset of lactase expression, and it also stimulated muscle and crypt formation. In order to analyze potential effects of RA mediated by mesenchymal cells, we isolated and characterized gut mucosa mesenchyme-derived cell cultures (mesenchyme-derived intestinal cell lines, MIC). These cells were shown to express mRNAs for retinoid binding proteins similar to those expressed in situ in the intestinal mesenchyme. MIC cells co-cultured with 14-day intestinal endoderms promoted endodermal cell adhesion and growth, and the addition of exogeneous RA enhanced epithelial cell polarization and differentiation assessed by cytokeratin and lactase immunostaining. Such a differentiating effect of RA was not observed on endodermal cells when cultured without a mesenchymal feeder layer or maintained in conditioned medium from RA-treated MIC cells. In the co-cultures, immunostaining of laminin and collagen IV with polyclonal antibodies, as well as alpha1 and beta1 laminin chains mRNAs (analyzed by RT-PCR) increased concurrently with the RA-enhanced differentiation of epithelial cells. It is worth noting that this stimulation by RA was also obvious on the mesenchymal cells cultured alone. These results show that RA plays a role in intestinal morphogenesis and differentiation. In addition, they indicate that RA acts on the mesenchymal cell phenotype and suggest that RA may modify the mesenchymal-epithelial cell interactions during intestinal development.

scholarly journals STRUCTURAL FEATURES OF THE EPITHELIO-MESENCHYMAL INTERFACE OF RAT DUODENAL MUCOSA DURING DEVELOPMENT

1972 ◽  
Vol 52 (3) ◽  
pp. 577-588 ◽  
Author(s):  
Minnie Mathan ◽  
John A. Hermos ◽  
Jerry S. Trier
Keyword(s):  
Epithelial Cell ◽  
Lamina Propria ◽  
Basal Lamina ◽  
Plasma Membranes ◽  
Mesenchymal Cell ◽  
Duodenal Mucosa ◽  
Mesenchymal Cells ◽  
Adult Rats ◽  
Contact Sites ◽  
Cell Processes

In fetal rats 5–7 days before birth, the duodenal epithelium is separated from mesenchymal cells by a well-defined basal lamina. By 3–4 days before birth, when small rudimentary villi are first seen, direct contact between epithelial and mesenchymal cells occurs by means of epithelial cell cytoplasmic processes which project through gaps in the basal lamina into the lamina propria. At contact sites, the epithelial and mesenchymal cell plasma membranes were less than 100 A apart but membrane fusion was not seen. In number and size these epithelial cell processes increase strikingly during the last 2 days of gestation, and they persist in large numbers until 7–10 days after birth. Thereafter, they decrease gradually in both number and size until 3–4 wk after birth, when the morphology of the epithelio-mesenchymal interface resembles that seen in adult rats, i.e., there are only rare epithelial cell processes which penetrate deeply into the lamina propria. The presence of a large number of epithelio-mesenchymal contact sites during the period of rapid growth and differentiation of duodenal mucosa may reflect epithelio-mesenchymal cell interactions which may facilitate the maturation of the duodenal mucosa.

Nonhematopoietic/endothelial SSEA-1+ cells define the most primitive progenitors in the adult murine bone marrow mesenchymal compartment

Blood ◽  
2006 ◽  
Vol 109 (3) ◽  
pp. 1298-1306 ◽  
Author(s):  
Fernando Anjos-Afonso ◽  
Dominique Bonnet
Keyword(s):  
Bone Marrow ◽  
Mesenchymal Cell ◽  
Cell Types ◽  
Mesenchymal Cells ◽  
Hierarchical Organization ◽  
Mesenchymal Progenitor Cells ◽  
Murine Bone Marrow

Abstract It is believed that a primitive cell type that maintains the mesenchymal compartment exists in the bone marrow. However, this putative mesenchymal stem/progenitor cell is yet to be identified and isolated. We are reporting the identification, isolation, and detailed characterization of the most primitive mesenchymal progenitor cells in the adult murine bone marrow, based on the expression of stage-specific embryonic antigen–1 (SSEA-1). This primitive subset can be identified in mesenchymal cell cultures and also directly in the bone marrow, thus ascertaining for the first time their existence in an adult organism. Characterization of SSEA-1+ mesenchymal cells revealed that upon purification these cells gave rise to SSEA-1− mesenchymal cells, whereas the reverse could not be observed. Also, these SSEA-1+ cells have a much higher capacity to differentiate than their negative counterparts, not only to several mesenchymal cell types but also to unconventional cell types such as astrocyte-, endothelial-, and hepatocyte-like cells in vitro. Most importantly, a single-cell–derived population was capable of differentiating abundantly into different mesenchymal cell types in vivo. Altogether we are proposing a hierarchical organization of the mesenchymal compartment, placing SSEA-1+ cells at the apex of this hierarchy.

scholarly journals Patterning of Endothelial Cells and Mesenchymal Stem Cells by Laser-Assisted Bioprinting to Study Cell Migration

2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Jean-Michel Bourget ◽  
Olivia Kérourédan ◽  
Manuela Medina ◽  
Murielle Rémy ◽  
Noélie Brunehilde Thébaud ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Cell Migration ◽  
Network Architecture ◽  
Mesenchymal Cell ◽  
Mesenchymal Cells ◽  
Specific Pattern ◽  
Trophic Factors ◽  
Collagen Hydrogel ◽  
Interesting Approach

Tissue engineering of large organs is currently limited by the lack of potent vascularizationin vitro. Tissue-engineered bone grafts can be prevascularizedin vitrousing endothelial cells (ECs). The microvascular network architecture could be controlled by printing ECs following a specific pattern. Using laser-assisted bioprinting, we investigated the effect of distance between printed cell islets and the influence of coprinted mesenchymal cells on migration. When printed alone, ECs spread out evenly on the collagen hydrogel, regardless of the distance between cell islets. However, when printed in coculture with mesenchymal cells by laser-assisted bioprinting, they remained in the printed area. Therefore, the presence of mesenchymal cell is mandatory in order to create a pattern that will be conserved over time. This work describes an interesting approach to study cell migration that could be reproduced to study the effect of trophic factors.

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