scholarly journals Expanding the Ig Superfamily Code for Laminar Specificity in Retina: Expression and Role of Contactins

2012 ◽  
Vol 32 (41) ◽  
pp. 14402-14414 ◽  
Author(s):  
M. Yamagata ◽  
J. R. Sanes
Development ◽  
2001 ◽  
Vol 128 (15) ◽  
pp. 3029-3039
Author(s):  
Eckart Förster ◽  
Shanting Zhao ◽  
Michael Frotscher

In various brain regions, particularly in the hippocampus, afferent fiber projections terminate in specific layers. Little is known about the molecular cues governing this laminar specificity. To this end we have recently shown that the innervation pattern of entorhinal fibers to the hippocampus is mimicked by the lamina-specific adhesion of entorhinal cells on living hippocampal slices, suggesting a role of adhesion molecules in the positioning of entorhinal fibers. Here, we have analyzed the role of extracellular matrix components in mediating this lamina-specific adhesion. We show that hyaluronidase treatment of hippocampal slices abolishes lamina-specific adhesion as well as layer-specific growth of entorhinal fibers to the dentate outer molecular layer in organotypic slice cultures. We conclude that hyaluronan-associated molecules play a crucial role in the formation of the lamina-specific entorhinal projection to the hippocampus.


2017 ◽  
Vol 29 (1) ◽  
pp. 1-16 ◽  
Author(s):  
Eduardo Martin-Lopez ◽  
Kimiko Ishiguro ◽  
Charles A Greer

Abstract Piriform cortex (PC) is a 3-layer paleocortex receiving primary afferent input from the olfactory bulb. The past decade has seen significant progress in understanding the synaptic, cellular and functional organization of PC, but PC embryogenesis continues to be enigmatic. Here, using birthdating strategies and clonal analyses, we probed the early development and laminar specificity of neurogenesis/gliogenesis as it relates to the organization of the PC. Our data demonstrate a temporal sequence of laminar-specific neurogenesis following the canonical “inside-out” pattern, with the notable exception of PC Layer II which exhibited an inverse “outside-in” temporal neurogenic pattern. Of interest, we found no evidence of a neurogenic gradient along the anterior to posterior axis, although the timing of neuronal migration and laminar development was delayed rostrally by approximately 24 h. To begin probing if lineage affected cell fate in the PC, we labeled PC neuroblasts using a multicolor technique and analyzed their laminar organization. Our results suggested that PC progenitors were phenotypically committed to reach specific layers early in the development. Collectively, these studies shed new light on the determinants of the laminar specificity of neuronal/glial organization in PC and the likely role of subpopulations of committed progenitors in regulating PC embryogenesis.


Molecules ◽  
2021 ◽  
Vol 26 (13) ◽  
pp. 3943
Author(s):  
Seyed Mohammad Gheibihayat ◽  
Ricardo Cabezas ◽  
Nikita G. Nikiforov ◽  
Tannaz Jamialahmadi ◽  
Thomas P. Johnston ◽  
...  

CD47 is a receptor belonging to the immunoglobulin (Ig) superfamily and broadly expressed on cell membranes. Through interactions with ligands such as SIRPα, TSP-1, integrins, and SH2-domain bearing protein tyrosine phosphatase substrate-1 (SHPS-1), CD47 regulates numerous functions like cell adhesion, proliferation, apoptosis, migration, homeostasis, and the immune system. In this aspect, previous research has shown that CD47 modulates phagocytosis via macrophages, the transmigration of neutrophils, and the activation of T-cells, dendritic cells, and B-cells. Moreover, several studies have reported the increased expression of the CD47 receptor in a variety of diseases, including acute lymphoblastic leukemia (ALL), chronic myeloid leukemia, non-Hodgkin’s lymphoma (NHL), multiple myeloma (MM), bladder cancer, acute myeloid leukemia (AML), Gaucher disease, Multiple Sclerosis and stroke among others. The ubiquitous expression of the CD47 cell receptor on most resident cells of the CNS has previously been established through different methodologies. However, there is little information concerning its precise functions in the development of different neurodegenerative pathologies in the CNS. Consequently, further research pertaining to the specific functions and roles of CD47 and SIRP is required prior to its exploitation as a druggable approach for the targeting of various neurodegenerative diseases that affect the human population. The present review attempts to summarize the role of both CD47 and SIRP and their therapeutic potential in neurodegenerative disorders.


1999 ◽  
Vol 10 (12) ◽  
pp. 2510-2517 ◽  
Author(s):  
AN S. DE VRIESE ◽  
KARLHANS ENDLICH ◽  
MARLIES ELGER ◽  
NORBERT H. LAMEIRE ◽  
ROBERT C. ATKINS ◽  
...  

Abstract. Leukocytes play a central role in the pathogenesis of anti-glomerular basement membrane glomerulonephritis (anti-GBM GN). Understanding the mechanisms underlying their recruitment in the glomerulus is of critical importance, because this may lead to more specific anti-inflammatory drug design. The requirement for integrins, especially from the β2 group, and their Ig superfamily counter-receptors has been established, however, the role of selectins remains controversial. An intravital microscopy technique was developed to study concomitantly the glomerular and venular leukocyte kinetics and the hemodynamic alterations in a rat model of anti-GBM GN, induced by injection of 10 mg of nephrotoxic serum (NTS). Histologic studies of the kidney were performed in parallel and urinary protein excretion was measured. The animals received NTS alone or were pretreated with either a monoclonal antibody against the β2 integrin CD11b (OX42, 4 mg/kg) or fucoidan F7 (FF7, 8 mg/kg), an oligosaccharide that blocks both L- and P-selectin function. Administration of NTS resulted in a time-dependent increase in the number of adherent leukocytes in the glomeruli and a parallel decrease of the perfused glomerular capillary area. Substantial proteinuria was observed. Pretreatment with OX42 significantly attenuated these changes. FF7 almost abolished the rolling of the leukocytes in the venules, thus demonstrating efficient anti-selectin activity. Nevertheless, FF7 had no influence on the glomerular events or on the development of proteinuria. These results confirm that glomerular leukocyte adhesion in anti-GBM GN is CD11b-dependent. However, selectin-mediated interaction between the leukocytes and the glomerular capillary endothelium does not appear to be a prerequisite for leukocyte adhesion in the glomerulus. These results therefore question the potential utility of anti-selectin therapy in the treatment of anti-GBM GN.


2001 ◽  
Vol 86 (07) ◽  
pp. 276-288 ◽  
Author(s):  
Naoki Asazuma ◽  
Ben Atkinson ◽  
Oscar Berlanga ◽  
Denise Best ◽  
Regis Bobe ◽  
...  

SummaryThe major activation-inducing collagen receptor glycoprotein VI (GPVI) has been cloned within the last two years. It is a member of the Ig superfamily of proteins and is constitutively associated with the ITAM-bearing Fc receptor γ-chain (FcR γ-chain). GPVI signals through a pathway that involves several of the proteins used by Fc, B- and T-lymphocyte receptors and which takes place in glycolipid-enriched membrane domains in the plasma membrane known as GEMs. Responses to GPVI are regulated by PECAM-1 (CD31) and possibly other ITIM-bearing receptors. Despite a pivotal role for GPVI, there are important differences between signalling events to collagen and GPVI-specific ligands. This may reflect a role for co-receptors in the response to collagen.


2001 ◽  
Vol 114 (7) ◽  
pp. 1321-1329 ◽  
Author(s):  
IM van Den Nieuwenhof ◽  
C. Renardel De Lavalette ◽  
N. Diaz ◽  
I. van Die ◽  
TK van Den Berg

Signal regulatory protein-(α) (SIRP(α)) is a member of the Ig superfamily selectively expressed by neuronal and myeloid cells. The molecule mediates functional interactions with CD47/integrin-associated protein. Here we provide evidence for the tissue-specific glycosylation of neuronal and haematopoietic SIRP(α). We demonstrate a major difference in the galactosylation of N-linked glycans isolated from neuronal (i.e. brain-derived) SIRP(α) as compared to myeloid (i.e. spleen-derived) SIRP(α), with neuronal SIRP(α) almost completely lacking galactose. (β)4-galactosyltransferase assays demonstrated that this is most likely due to a low galactosylation capacity of the brain. In order to investigate the role of galactosylation of SIRP(α) in cellular interactions, soluble recombinant SIRP(α) glycoforms containing galactose (SIRP(α)-Fc) or lacking galactose (SIRP(α)((Δ)Gal)-Fc) were produced. Binding studies demonstrated superior binding of SIRP(α)((Δ)Gal)-Fc to cerebellar neurons and isolated lymphocytes. In contrast, SIRP(α)-Fc bound relatively strong to macrophages. These data show that the galactosylation of SIRP(α) determines its cellular binding specificity.


JAMA ◽  
1966 ◽  
Vol 195 (12) ◽  
pp. 1005-1009 ◽  
Author(s):  
D. J. Fernbach
Keyword(s):  

JAMA ◽  
1966 ◽  
Vol 195 (3) ◽  
pp. 167-172 ◽  
Author(s):  
T. E. Van Metre

2018 ◽  
Vol 41 ◽  
Author(s):  
Winnifred R. Louis ◽  
Craig McGarty ◽  
Emma F. Thomas ◽  
Catherine E. Amiot ◽  
Fathali M. Moghaddam

AbstractWhitehouse adapts insights from evolutionary anthropology to interpret extreme self-sacrifice through the concept of identity fusion. The model neglects the role of normative systems in shaping behaviors, especially in relation to violent extremism. In peaceful groups, increasing fusion will actually decrease extremism. Groups collectively appraise threats and opportunities, actively debate action options, and rarely choose violence toward self or others.


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