scholarly journals In Vivo and In VitroExpression of Tenascin by Human Thymic Microenvironmental Cells

1995 ◽  
Vol 4 (2) ◽  
pp. 139-147 ◽  
Author(s):  
Claudia Sondermann Freitas ◽  
Jurandy Susana Patricia O'Campo Lyra ◽  
Sergio Ranto Dalmau ◽  
Wilson Savino
Keyword(s):  
Extracellular Matrix ◽  
Matrix Protein ◽  
Basement Membranes ◽  
Extracellular Matrix Protein ◽  
Thymic Epithelial Cell ◽  
Normal Infant ◽  
Cell Network ◽  
Extracellular Matrix Components

Increasing evidence reveals that extracellular matrix components can be regarded as a group of mediators in intrathymic T-cell migration and/or differentiation. Yet, little is kown about the expression and putative function of one particular extracellular matrix protein, namely, tenascin in the thymus. Herein we investigated, by means of immunocytochemistry, tenascin expression in normal infant and fetal human thymuses, as well as in cultures of thymic microenvironmental cells.In situ, tenascin distribution is restricted to the medulla and cortico-medullary regions of normal thymuses. This pattern thus differed from that of fibronectin, laminin and type IV collagen, in which subseptal basement membranes were strongly labeled. Interestingly, tenascin did not co-localize with the cytokeratin-defined thymic epithelial cell network. This was in keeping with thein vitrodata showing that tenascin-bearing cells were nonepithelial (and probably nonfibroblastic) microenvironmental elements.Studies with fetal thymuses revealed a developmentally regulated expression of tenascin, with a faint but consistent network labeling, in thymic rudiments as early as 12 weeks of gestational age, that progressed to a strong TN expression at 18 weeks of fetal development, which was similar to the distribution pattern observed thereafter, including postnatally.Our results clearly indicated that tenascin is constitutively expressed in the human thymus, since early stages of thymic ontogeny, and suggest that the cell type responsible for its secretion is a nonepithelial microenvironmental cell.

scholarly journals Extracellular matrix components of the mouse thymus microenvironment: ontogenetic studies and modulation by glucocorticoid hormones.

1991 ◽  
Vol 39 (11) ◽  
pp. 1539-1546 ◽  
Author(s):  
J Lannes-Vieira ◽  
M Dardenne ◽  
W Savino
Keyword(s):  
Extracellular Matrix ◽  
Basement Membrane ◽  
Type I Collagen ◽  
Basement Membranes ◽  
Thymic Epithelial Cell ◽  
Epithelial Cell Line ◽  
Type I ◽  
Extracellular Matrix Components

The present investigation was an ontogenetic study on the distribution of extracellular matrix (ECM) components in the thymic microenvironment of C57BL/6 mice (comprising young and old adults and developing embryos) and NZB mice. In addition, we evaluated the in vivo and in vitro influence of hydrocortisone treatment on basement membrane protein production by a thymic epithelial cell line. In young normal animals, Type I collagen was restricted to the interstitial spaces of the capsule and septa, where Type IV collagen, fibronectin, and laminin could be detected in the basement membranes. In addition, fibronectin-containing fibers were seen within the medulla of the thymic lobules. The ECM distribution pattern in the developing embryos was distinct from that observed in adults, since a fine meshwork of basement membrane-containing proteins was clearly seen throughout the parenchyma. Moreover, aging normal and NZB mice exhibited a denser ECM pattern than young adult normal animals. Treatment with hydrocortisone, both in vivo and in vitro, resulted in enhancement of ECM expression, detected in mice as early as 2 hr post injection and lasting for several days. Considering that the fluctuations of ECM expression parallel important events in thymocyte differentiation, we discuss the possibility that the two phenomena may be associated.

scholarly journals The extracellular matrix protein mindin serves as an integrin ligand and is critical for inflammatory cell recruitment

Blood ◽  
2005 ◽  
Vol 106 (12) ◽  
pp. 3854-3859 ◽  
Author(s):  
Wei Jia ◽  
Hong Li ◽  
You-Wen He
Keyword(s):  
Extracellular Matrix ◽  
Matrix Protein ◽  
Inflammatory Cell ◽  
Neutrophil Migration ◽  
Extracellular Matrix Protein ◽  
Hek 293 ◽  
Cell Recruitment ◽  
Inflammatory Cell Recruitment

Leukocyte recruitment to inflammation sites depends on interactions between integrins and extracellular matrix (ECM). In this report we show that mice lacking the ECM protein mindin exhibit severely impaired recruitment of neutrophils and macrophages in 4 different inflammation models. Furthermore, neutrophils directly bind to immobilized mindin, and mindin matrix mediates neutrophil migration in vitro. The adhesion of neutrophils to mindin is blocked by anti–integrin α4, anti–integrin αM, and anti–integrin β2 antibodies. We also show that HEK-293 cells transfected with cDNA encoding these integrins exhibit enhanced binding to immobilized mindin matrix and the increased binding can be blocked by anti-integrin antibodies. Our results suggest that mindin serves as a novel ligand for integrins and mindin-integrin interactions are critical for inflammatory cell recruitment in vivo.

scholarly journals Venular basement membranes contain specific matrix protein low expression regions that act as exit points for emigrating neutrophils

2006 ◽  
Vol 203 (6) ◽  
pp. 1519-1532 ◽  
Author(s):  
Shijun Wang ◽  
Mathieu-Benoit Voisin ◽  
Karen Y. Larbi ◽  
John Dangerfield ◽  
Christoph Scheiermann ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Serine Proteases ◽  
Matrix Protein ◽  
Unit Area ◽  
Protein Localization ◽  
Basement Membranes ◽  
Extracellular Matrix Protein ◽  
Plausible Mechanism ◽  
Low Expression

The mechanism of leukocyte migration through venular walls in vivo is largely unknown. By using immunofluorescence staining and confocal microscopy, the present study demonstrates the existence of regions within the walls of unstimulated murine cremasteric venules where expression of key vascular basement membrane (BM) constituents, laminin 10, collagen IV, and nidogen-2 (but not perlecan) are considerably lower (<60%) than the average expression detected in the same vessel. These sites were closely associated with gaps between pericytes and were preferentially used by migrating neutrophils during their passage through cytokine-stimulated venules. Although neutrophil transmigration did not alter the number/unit area of extracellular matrix protein low expression sites, the size of these regions was enlarged and their protein content was reduced in interleukin-1β–stimulated venules. These effects were entirely dependent on the presence of neutrophils and appeared to involve neutrophil-derived serine proteases. Furthermore, evidence was obtained indicating that transmigrating neutrophils carry laminins on their cell surface in vivo. Collectively, through identification of regions of low extracellular matrix protein localization that define the preferred route for transmigrating neutrophils, we have identified a plausible mechanism by which neutrophils penetrate the vascular BM without causing a gross disruption to its intricate structure.

Phosphorylation of the carboxyl-terminal region of dystrophin

1996 ◽  
Vol 74 (4) ◽  
pp. 431-437 ◽  
Author(s):  
Marek Michalak ◽  
Susan Y. Fu ◽  
Rachel E. Milner ◽  
Jody L. Busaan ◽  
Jacqueline E. Hance
Keyword(s):  
Extracellular Matrix ◽  
Muscular Dystrophy ◽  
Protein Kinases ◽  
Protein Interactions ◽  
Matrix Protein ◽  
Casein Kinase ◽  
Terminal Region ◽  
Extracellular Matrix Protein

Dystrophin is a protein product of the gene responsible for Duchenne and Becker muscular dystrophy. The protein is localized to the inner surface of sarcolemma and is associated with a group of membrane (glyco)proteins. Dystrophin links cytoskeletal actins via the dystrophin-associated protein complex to extracellular matrix protein, laminin. This structural organization implicates the role of dystrophin in stabilizing the sarcolemma of muscle fibers. Precisely how dystrophin functions is far from clear. The presence of an array of isoforms of the C-terminal region of dystrophin suggests that dystrophin may have functions other than structural. In agreement, many potential phosphorylation sites are found in the C-terminal region of dystrophin, and the C-terminal region of dystrophin is phosphorylated both in vitro and in vivo by many protein kinases, including MAP kinase, p34cdc2 kinase, CaM kinase, and casein kinase, and is dephosphorylated by calcineurin. The C-terminal domain of dystrophin is also a substrate for hierarchical phosporylation by casein kinase-2 and GSK-3. These observations, in accordance with the finding that the cysteine-rich region binds to Ca2+, Zn2+, and calmodulin, suggest an active involvement of dystrophin in transducing signals across muscle sarcolemma. Phosphorylation–dephosphorylation of the C-terminal region of dystrophin may play a role in regulating dystrophin–protein interactions and (or) transducing signal from the extracellular matrix via the dystrophin molecule to the cytoskeleton.Key words: Duchenne muscular dystrophy, protein phosphorylation, protein kinases, calcineurin, cytoskeleton.

scholarly journals The Ig-like domain of Punctin/MADD-4 is the primary determinant for interaction with the ectodomain of neuroligin NLG-1

2020 ◽  
pp. jbc.RA120.014591
Author(s):  
Semeli Platsaki ◽  
Xin Zhou ◽  
Bérangère Pinan-Lucarré ◽  
Vincent Delauzun ◽  
Haijun Tu ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Matrix Protein ◽  
Neuromuscular Junctions ◽  
Heparan Sulphate ◽  
Extracellular Matrix Protein ◽  
Inhibitory Synapses ◽  
Primary Determinant ◽  
Gabaergic Synapses

Punctin/MADD-4, a member of the ADAMTSL extracellular matrix protein family, was identified as an anterograde synaptic organizer in the nematode Caenorhabditis elegans. At GABAergic neuromuscular junctions, the short isoform MADD-4B binds the ectodomain of neuroligin NLG-1, itself a postsynaptic organizer of inhibitory synapses. To identify the molecular bases of their partnership, we generated recombinant forms of the two proteins and carried out a comprehensive biochemical and biophysical study of their interaction, complemented by an in vivo localisation study. We show that spontaneous proteolysis of MADD-4B first generates a shorter N-MADD-4B form, which comprises four thrombospondin (TSP) and one Ig-like domains and binds NLG-1. A second processing event eliminates the C-terminal Ig-like domain along with the ability of N-MADD-4B to bind NLG-1. These data identify the Ig-like domain as the primary determinant for N-MADD-4B interaction with NLG-1 in vitro. We further demonstrate in vivo that this Ig-like domain is essential, albeit not sufficient per se, for efficient recruitment of GABAA receptors at GABAergic synapses in C. elegans. The interaction of N-MADD-4B with NLG-1 is also disrupted by heparin, used as a surrogate for the extracellular matrix component, heparan sulphate, and whose high-affinity binding to the Ig-like domain may proceed from surface charge complementarity, as suggested by homology 3D modelling. These data point to N-MADD-4B processing and cell-surface proteoglycan binding as two possible mechanisms that can regulate the interaction between MADD-4B and NLG-1 at GABAergic synapses.

Acute knockdown of extracellular matrix protein Tinagl1 disrupts heart laterality and pronephric cilia in zebrafish embryonic development

2020 ◽  
Author(s):  
Hannah Neiswender ◽  
Ellen K. LeMosy
Keyword(s):  
Spinal Cord ◽  
Extracellular Matrix ◽  
Matrix Protein ◽  
Extracellular Matrix Protein ◽  
Pronephric Duct ◽  
Motile Cilia ◽  
Somatic Mutagenesis ◽  
Genetic Compensation

AbstractA highly-conserved extracellular matrix protein, Tinagl1, modulates Wnt, integrin, TGF-β, and EGF-R signaling in vitro, but its significance in vivo has remained in doubt. To bypass possible genetic compensation by an ortholog encoded exclusively in mammalian genomes, we examine Tinagl1 function in zebrafish embryos. In this model, tinagl1 mRNA is detected in the developing spinal cord and pronephros. Acute knockdown using either CRISPR/Cas9 somatic mutagenesis or splice-blocking morpholinos reveals left-right (LR) heart looping defects, pronephros dilatations, and ventral body curvature. This constellation of defects characteristically results from the loss of motile cilia function, and we confirm the presence of shortened and fewer cilia in the pronephric duct and in the Kupffer’s vesicle where LR asymmetry is established. A link to known Wnt3a/β-catenin signaling that activates the motile cilia transcriptional program is supported by manipulation of Wnt3a and β-catenin levels in tinagl1 knockdown embryos. In addition to ciliopathy-like defects, the tinagl1 knockdown shows disorganization of longitudinal axon tracts in the spinal cord and defects in motor neuron outgrowth. Together, these results provide evidence that Tinagl1 is important in development, and that zebrafish is an ideal model in which to explore its relationships to cilia and secreted signaling molecules.

scholarly journals Correction: A novel chemotactic factor derived from the extracellular matrix protein decorin recruits mesenchymal stromal cells in vitro and in vivo

PLoS ONE ◽  
2020 ◽  
Vol 15 (9) ◽  
pp. e0238964
Author(s):  
Sandi G. Dempsey ◽  
Christopher H. Miller ◽  
Julia Schueler ◽  
Robert W. F. Veale ◽  
Darren J. Day ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Mesenchymal Stromal Cells ◽  
Stromal Cells ◽  
Matrix Protein ◽  
Chemotactic Factor ◽  
Extracellular Matrix Protein

scholarly journals A novel chemotactic factor derived from the extracellular matrix protein decorin recruits mesenchymal stromal cells in vitro and in vivo

PLoS ONE ◽  
2020 ◽  
Vol 15 (7) ◽  
pp. e0235784 ◽  
Author(s):  
Sandi Grainne Dempsey ◽  
Christopher Hamilton Miller ◽  
Julia Schueler ◽  
Robert W. F. Veale ◽  
Darren J. Day ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Mesenchymal Stromal Cells ◽  
Stromal Cells ◽  
Matrix Protein ◽  
Chemotactic Factor ◽  
Extracellular Matrix Protein

scholarly journals Low-Intensity Pulsed Ultrasound Promotes Autophagy-Mediated Migration of Mesenchymal Stem Cells and Cartilage Repair

2021 ◽  
Vol 30 ◽  
pp. 096368972098614
Author(s):  
Peng Xia ◽  
Xinwei Wang ◽  
Qi Wang ◽  
Xiaoju Wang ◽  
Qiang Lin ◽  
...  
Keyword(s):  
Cartilage Repair ◽  
Matrix Protein ◽  
Extracellular Matrix Protein ◽  
Histopathological Analysis ◽  
Pulsed Ultrasound ◽  
Low Intensity Pulsed Ultrasound ◽  
Low Intensity ◽  
Autophagy Inhibitor

Mesenchymal stem cell (MSC) migration is promoted by low-intensity pulsed ultrasound (LIPUS), but its mechanism is unclear. Since autophagy is known to regulate cell migration, our study aimed to investigate if LIPUS promotes the migration of MSCs via autophagy regulation. We also aimed to investigate the effects of intra-articular injection of MSCs following LIPUS stimulation on osteoarthritis (OA) cartilage. For the in vitro study, rat bone marrow-derived MSCs were treated with an autophagy inhibitor or agonist, and then they were stimulated by LIPUS. Migration of MSCs was detected by transwell migration assays, and stromal cell-derived factor-1 (SDF-1) and C-X-C chemokine receptor type 4 (CXCR4) protein levels were quantified. For the in vivo study, a rat knee OA model was generated and treated with LIPUS after an intra-articular injection of MSCs with autophagy inhibitor added. The cartilage repair was assessed by histopathological analysis and extracellular matrix protein expression. The in vitro results suggest that LIPUS increased the expression of SDF-1 and CXCR4, and it promoted MSC migration. These effects were inhibited and enhanced by autophagy inhibitor and agonist, respectively. The in vivo results demonstrate that LIPUS significantly enhanced the cartilage repair effects of MSCs on OA, but these effects were blocked by autophagy inhibitor. Our results suggest that the migration of MSCs was enhanced by LIPUS through the activation autophagy, and LIPUS improved the protective effect of MSCs on OA cartilage via autophagy regulation.

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