scholarly journals Regulation and function of axon guidance and adhesion molecules during olfactory map formation

2011 ◽  
Vol 112 (10) ◽  
pp. 2663-2671 ◽  
Author(s):  
Gerald A. Schwarting ◽  
Timothy R. Henion
Keyword(s):  
Axon Guidance ◽  
Adhesion Molecules ◽  
And Function ◽  
Olfactory Map

scholarly journals Cadherins in early neural development

2021 ◽  
Author(s):  
Karolina Punovuori ◽  
Mattias Malaguti ◽  
Sally Lowell
Keyword(s):  
Adhesion Molecules ◽  
Cell Fate ◽  
Neural Development ◽  
Ex Vivo ◽  
Directed Differentiation ◽  
Culture Dish ◽  
Cell Identity ◽  
Cell Fate Decisions ◽  
Neural Tissues ◽  
And Function

AbstractDuring early neural development, changes in signalling inform the expression of transcription factors that in turn instruct changes in cell identity. At the same time, switches in adhesion molecule expression result in cellular rearrangements that define the morphology of the emerging neural tube. It is becoming increasingly clear that these two processes influence each other; adhesion molecules do not simply operate downstream of or in parallel with changes in cell identity but rather actively feed into cell fate decisions. Why are differentiation and adhesion so tightly linked? It is now over 60 years since Conrad Waddington noted the remarkable "Constancy of the Wild Type” (Waddington in Nature 183: 1654–1655, 1959) yet we still do not fully understand the mechanisms that make development so reproducible. Conversely, we do not understand why directed differentiation of cells in a dish is sometimes unpredictable and difficult to control. It has long been suggested that cells make decisions as 'local cooperatives' rather than as individuals (Gurdon in Nature 336: 772–774, 1988; Lander in Cell 144: 955–969, 2011). Given that the cadherin family of adhesion molecules can simultaneously influence morphogenesis and signalling, it is tempting to speculate that they may help coordinate cell fate decisions between neighbouring cells in the embryo to ensure fidelity of patterning, and that the uncoupling of these processes in a culture dish might underlie some of the problems with controlling cell fate decisions ex-vivo. Here we review the expression and function of cadherins during early neural development and discuss how and why they might modulate signalling and differentiation as neural tissues are formed.

scholarly journals Three C. elegans Rac proteins and several alternative Rac regulators control axon guidance, cell migration and apoptotic cell phagocytosis

Development ◽  
2001 ◽  
Vol 128 (22) ◽  
pp. 4475-4488 ◽  
Author(s):  
Erik A. Lundquist ◽  
Peter W. Reddien ◽  
Erika Hartwieg ◽  
H. Robert Horvitz ◽  
Cornelia I. Bargmann
Keyword(s):  
Cell Migration ◽  
Axon Guidance ◽  
Apoptotic Cell ◽  
Regulatory Proteins ◽  
Axon Pathfinding ◽  
C Elegans ◽  
Cell Corpse ◽  
And Function ◽  
Redundant Functions ◽  
Caenorhabditis Elegans Genome

The Caenorhabditis elegans genome contains three rac-like genes, ced-10, mig-2, and rac-2. We report that ced-10, mig-2 and rac-2 act redundantly in axon pathfinding: inactivating one gene had little effect, but inactivating two or more genes perturbed both axon outgrowth and guidance. mig-2 and ced-10 also have redundant functions in some cell migrations. By contrast, ced-10 is uniquely required for cell-corpse phagocytosis, and mig-2 and rac-2 have only subtle roles in this process. Rac activators are also used differentially. The UNC-73 Trio Rac GTP exchange factor affected all Rac pathways in axon pathfinding and cell migration but did not affect cell-corpse phagocytosis. CED-5 DOCK180, which acts with CED-10 Rac in cell-corpse phagocytosis, acted with MIG-2 but not CED-10 in axon pathfinding. Thus, distinct regulatory proteins modulate Rac activation and function in different developmental processes.

Sperm Adhesion Molecules: Structure and Function

2000 ◽  
Vol 168 (1-2) ◽  
pp. 82-92 ◽  
Author(s):  
Stephan Jansen ◽  
Mahnaz Ekhlasi-Hundrieser ◽  
Edda Töpfer-Petersen
Keyword(s):  
Adhesion Molecules ◽  
Structure And Function ◽  
And Function

scholarly journals Renal allograft rejection: induction and function of adhesion molecules on cultured epithelial cells

2008 ◽  
Vol 90 (1) ◽  
pp. 111-116 ◽  
Author(s):  
Y. LIN ◽  
J. A. KIRBY ◽  
K. CLARK ◽  
B. K. SHENTON ◽  
J. L. R. FORSYTHE ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Adhesion Molecules ◽  
Allograft Rejection ◽  
Renal Allograft ◽  
Renal Allograft Rejection ◽  
Cultured Epithelial Cells ◽  
And Function

Pre-Target Axon Sorting Establishes the Neural Map Topography

Science ◽  
2009 ◽  
Vol 325 (5940) ◽  
pp. 585-590 ◽  
Author(s):  
Takeshi Imai ◽  
Takahiro Yamazaki ◽  
Reiko Kobayakawa ◽  
Ko Kobayakawa ◽  
Takaya Abe ◽  
...  
Keyword(s):  
Nervous System ◽  
Axon Guidance ◽  
Sensory Neuron ◽  
Sensory Neurons ◽  
Sensory Information ◽  
Topographic Map ◽  
Semaphorin 3A ◽  
Neuropilin 1 ◽  
The Brain ◽  
Olfactory Map

Sensory information detected by the peripheral nervous system is represented as a topographic map in the brain. It has long been thought that the topography of the map is determined by graded positional cues that are expressed by the target. Here, we analyzed the pre-target axon sorting for olfactory map formation in mice. In olfactory sensory neurons, an axon guidance receptor, Neuropilin-1, and its repulsive ligand, Semaphorin-3A, are expressed in a complementary manner. We found that expression levels of Neuropilin-1 determined both pre-target sorting and projection sites of axons. Olfactory sensory neuron–specific knockout of Semaphorin-3A perturbed axon sorting and altered the olfactory map topography. Thus, pre-target axon sorting plays an important role in establishing the topographic order based on the relative levels of guidance molecules expressed by axons.

scholarly journals Role of glucocorticoids in neutrophil and endothelial adhesion molecule expression and function

1992 ◽  
Vol 1 (2) ◽  
pp. 101-106 ◽  
Author(s):  
Kevin D. Forsyth ◽  
Vivienne Talbot
Keyword(s):  
Inflammatory Response ◽  
Adhesion Molecules ◽  
Adhesion Molecule ◽  
Antigen Expression ◽  
Neutrophil Adhesion ◽  
Adhesion Molecule Expression ◽  
Chronic Inflammatory Response ◽  
Endothelial Adhesion Molecule ◽  
And Function

Glucocorticoids are very effective inhibitors of both the acute and chronic inflammatory response. In this study the hypothesis that glucocorticoids inhibit an early component of the inflammatory response, neutrophil adhesion to endothelium, by down-regulation of adhesion molecules on neutrophils or endothelium was examined. No effect of dexamethasone on neutrophil adhesion to endothelium or of antigen expression by neutrophils or endothelium was found. The mechanism of action of glucocorticoids in the inflammatory response is probably not mediated by alterations in adhesion molecules.

scholarly journals Changes in Cell Vitality, Phenotype, and Function of Dromedary Camel Leukocytes After Whole Blood Exposure to Heat Stress in vitro

2021 ◽  
Vol 8 ◽  
Author(s):  
Jamal Hussen
Keyword(s):  
Heat Stress ◽  
Adhesion Molecules ◽  
Mhc Class Ii ◽  
Whole Blood ◽  
Dromedary Camel ◽  
Macrophage Phenotype ◽  
Cell Vitality ◽  
And Function

The dromedary camel (Camelus dromedarius) is well-adapted to the desert environment with the ability to tolerate increased internal body temperatures rising daily to 41–42°C during extreme hot. This study was undertaken to assess whether in vitro incubation of camel blood at 41°C, simulating conditions of heat stress, differently alters cell vitality, phenotype, and function of leukocytes, compared to incubation at 37°C (normothermia). Using flow cytometry, the cell vitality (necrosis and apoptosis), the expression of several cell markers and adhesion molecules, and the antimicrobial functions of camel leukocytes were analyzed in vitro. The fraction of apoptotic cells within the granulocytes, lymphocytes, and monocytes increased significantly after incubation of camel whole blood at 41°C for 4 h. The higher increase in apoptotic granulocytes and monocytes compared to lymphocytes suggests higher resistance of camel lymphocytes to heat stress. Functionally, incubation of camel blood at 41°C for 4 h enhanced the phagocytosis and ROS production activities of camel neutrophils and monocytes toward S. aureus. Monocytes from camel blood incubated at 41°C for 4 h significantly decreased their expression level of MHC class II molecules with no change in the abundance of CD163, resulting in a CD163high MHC-IIlow M2-like macrophage phenotype. In addition, heat stress treatment showed an inhibitory effect on the LPS-induced changes in camel monocytes phenotype. Furthermore, in vitro incubation of camel blood at 41°C reduced the expression of the cell adhesion molecules CD18 and CD11a on neutrophils and monocytes. Collectively, the present study identified some heat-stress-induced phenotypic and functional alterations in camel blood leukocytes, providing a paradigm for comparative immunology in the large animals. The clinical relevance of the observed changes in camel leukocytes for the adaptation of the camel immune response to heat stress conditions needs further in vitro and in vivo studies.

scholarly journals Characterization of adhesion molecules on human myeloma cell lines

Blood ◽  
1992 ◽  
Vol 80 (9) ◽  
pp. 2306-2314 ◽  
Author(s):  
H Uchiyama ◽  
BA Barut ◽  
D Chauhan ◽  
SA Cannistra ◽  
KC Anderson
Keyword(s):  
Adhesion Molecules ◽  
Cell Lines ◽  
Plasma Cells ◽  
Specific Binding ◽  
Myeloma Cell ◽  
Rgd Peptide ◽  
Beta 1 Integrin ◽  
Marrow Stroma ◽  
And Function ◽  
Alpha V Beta 3

In multiple myeloma, malignant plasma cells are localized in marrow and rarely circulate in peripheral blood. To investigate the role of adhesion proteins in this process, we determined the expression and function of adhesion molecules on cell lines derived from patients with myeloma. The U266, ARH-77, IM-9, and HS-Sultan cell lines strongly expressed beta 1 and alpha 4 integrins (89% to 98% positive), confirming that VLA-4 is the principal integrin on these cell lines. The U266 and IM-9 cell lines also expressed alpha 3 integrin on 15% to 20% cells. In contrast, all lines lacked cell surface alpha 2, alpha 5, and alpha 6 integrin expression (< 5% positive). These cell lines adhered to fibronectin (20% to 40% specific binding), without significant binding to either collagen or laminin. Adhesion of these cell lines to fibronectin was partially blocked with either anti-beta 1 integrin monoclonal antibody (MoAb) (75% inhibition), anti-alpha 4 integrin MoAb (75% inhibition), or RGD peptide (50% inhibition), but was unaffected by anti-alpha v beta 3 or anti-alpha IIb beta 3 MoAbs. Moreover, the combination of anti-beta 1 plus RGD peptide or anti-alpha 4 plus RGD peptide inhibited binding to fibronectin by 80% and 95%, respectively. Finally, pretreatment and coculture of the IM-9 cell line with interleukin-6 (IL-6) resulted in a 52% decrease in specific binding to fibronectin (30% +/- 6% to 15% +/- 6%; P = .001), associated with a decrease in the number of cells expressing VLA-4 and a decrease in intensity of VLA-4 expression. These data suggest that myeloma cells adhere to fibronectin through VLA-4 as well as through RGD-dependent mechanisms, and that this binding can be downregulated by IL-6. Future studies of binding of both myeloma cell lines and freshly isolated tumor cells to extracellular matrix proteins and to marrow stroma may enhance our understanding of localization and trafficking of cells within the bone marrow microenvironment.

Sign in / Sign up

Export Citation Format

Share Document