A role for the EphA family in the topographic targeting of vomeronasal axons

Development ◽  
2001 ◽  
Vol 128 (6) ◽  
pp. 895-906
Author(s):  
B. Knoll ◽  
K. Zarbalis ◽  
W. Wurst ◽  
U. Drescher

We have investigated the role of the Eph family of receptor tyrosine kinases and their ligands in the establishment of the vomeronasal projection in the mouse. Our data show intriguing differential expression patterns of ephrin-A5 on vomeronasal axons and of EphA6 in the accessory olfactory bulb (AOB), such that axons with high ligand concentration project onto regions of the AOB with high receptor concentration and vice versa. These data suggest a mechanism for development of this projection that is the opposite of the repellent interaction between Eph receptors and ligands observed in other systems. In support of this idea, when given the choice of whether to grow on lanes containing EphA-F(c)/laminin or F(c)/laminin protein (in the stripe assay), vomeronasal axons prefer to grow on EphA-F(c)/laminin. Analysis of ephrin-A5 mutant mice revealed a disturbance of the topographic targeting of vomeronasal axons to the AOB. In summary, these data, which are derived from in vitro and in vivo experiments, indicate an important role of the EphA family in setting up the vomeronasal projection.

Cancers ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 1330
Author(s):  
Filipe Pinto ◽  
Liliana Santos-Ferreira ◽  
Marta T. Pinto ◽  
Catarina Gomes ◽  
Celso A. Reis

Biglycan (BGN gene), an extracellular proteoglycan, has been described to be associated with cancer aggressiveness. The purpose of this study was to clarify the clinical value of biglycan as a biomarker in multiple independent GC cohorts and determine the in vitro and in vivo role of biglycan in GC malignant features. We found that BGN is commonly over-expressed in all analyzed cohorts, being associated with disease relapse and poor prognosis in patients with advanced stages of disease. In vitro and in vivo experiments demonstrated that biglycan knock-out GC cells display major phenotypic changes with a lower cell survival, migration, and angiogenic potential when compared with biglycan expressing cells. Biglycan KO GC cells present increased levels of PARP1 and caspase-3 cleavage and a decreased expression of mesenchymal markers. Importantly, biglycan deficient GC cells that were supplemented with exogenous biglycan were able to restore biological features, such as survival, clonogenic and migratory capacities. Our in vitro and in vivo findings were validated in human GC samples, where BGN expression was associated with several oncogenic gene signatures that were associated with apoptosis, cell migration, invasion, and angiogenesis. This study provided new insights on biglycan role in GC that should be taken in consideration as a key cellular regulator with major impact in tumor progression and patients’ clinical outcome.


2007 ◽  
Vol 292 (4) ◽  
pp. L915-L923 ◽  
Author(s):  
Jaime Chávez ◽  
Patricia Segura ◽  
Mario H. Vargas ◽  
José Luis Arreola ◽  
Edgar Flores-Soto ◽  
...  

Organophosphates induce bronchoobstruction in guinea pigs, and salbutamol only transiently reverses this effect, suggesting that it triggers additional obstructive mechanisms. To further explore this phenomenon, in vivo (barometric plethysmography) and in vitro (organ baths, including ACh and substance P concentration measurement by HPLC and immunoassay, respectively; intracellular Ca2+ measurement in single myocytes) experiments were performed. In in vivo experiments, parathion caused a progressive bronchoobstruction until a plateau was reached. Administration of salbutamol during this plateau decreased bronchoobstruction up to 22% in the first 5 min, but thereafter airway obstruction rose again as to reach the same intensity as before salbutamol. Aminophylline caused a sustained decrement (71%) of the parathion-induced bronchoobstruction. In in vitro studies, paraoxon produced a sustained contraction of tracheal rings, which was fully blocked by atropine but not by TTX, ω-conotoxin (CTX), or epithelium removal. During the paraoxon-induced contraction, salbutamol caused a temporary relaxation of ∼50%, followed by a partial recontraction. This paradoxical recontraction was avoided by the M2- or neurokinin-1 (NK1)-receptor antagonists (methoctramine or AF-DX 116, and L-732138, respectively), accompanied by a long-lasting relaxation. Forskolin caused full relaxation of the paraoxon response. Substance P and, to a lesser extent, ACh released from tracheal rings during 60-min incubation with paraoxon or physostigmine, respectively, were significantly increased when salbutamol was administered in the second half of this period. In myocytes, paraoxon did not produce any change in the intracellular Ca2+ basal levels. Our results suggested that: 1) organophosphates caused smooth muscle contraction by accumulation of ACh released through a TTX- and CTX-resistant mechanism; 2) during such contraction, salbutamol relaxation is functionally antagonized by the stimulation of M2 receptors; and 3) after this transient salbutamol-induced relaxation, a paradoxical contraction ensues due to the subsequent release of substance P.


1975 ◽  
Vol 21 (4) ◽  
pp. 521-527 ◽  
Author(s):  
Noritake Asato ◽  
Maria van Soestbergen ◽  
F William Sunderman

Abstract Binding of 63Ni(Il) to ultrafiltrable constituents of rabbit serum was studied (a) after in vitro incubation (2 h, 37 °C) of rabbit serum with 63NiCl2 (10-100 µmol/liter), and (b) at intervals (0.25-2 h) after in vivo administration of 63NiCl2 (40-160 µmol/kg body wt, i.v.). Serum ultrafiltrates were fractionated by thin-layer chromatography, and the separated compounds made visible by autoradiography and by ninhydrin staining. Several (≃5) ultrafiltrable 63Ni-complexes were demonstrable as distinct radiodense 63Ni-bands with chromatographic mobilities corresponding to those of ninhydrin-positive bands. Unbound 63Ni(II) was not detected in serum ultrafiltrates in either the in vitro or in vivo experiments. In sera (n = 10) incubated in vitro with 63Ni(II) (10 µmol/ liter), the mean percentage of ultrafiltrable 63Ni was 36% (range = 33-38) of total serum 63Ni. In contrast, in sera (n = 10) obtained 2 h after i.v. injection of 63Ni(II) (40 µmol/kg), the mean concentration of total serum 63Ni was 10.8 µmol/liter (range = 6-14), and the mean percentage of ultrafiltrable 63Ni was 15% (range = 9-21) of total serum 63Ni. The disparity between the percentages of ultrafiltrable 63Ni obtained in vitro and in vivo was obviated when the in vivo experiments were performed in rabbits bilaterally nephrectomized, with ligated common bile ducts. This investigation confirms the existence of several nickel receptors in serum ultrafiltrates and substantiates the role of ultrafiltrable complexes in the excretion of nickel.


2018 ◽  
Vol 215 (6) ◽  
pp. 1709-1727 ◽  
Author(s):  
Kelly Mitchell ◽  
Laura Barreyro ◽  
Tihomira I. Todorova ◽  
Samuel J. Taylor ◽  
Iléana Antony-Debré ◽  
...  

The surface molecule interleukin-1 receptor accessory protein (IL1RAP) is consistently overexpressed across multiple genetic subtypes of acute myeloid leukemia (AML) and other myeloid malignancies, including at the stem cell level, and is emerging as a novel therapeutic target. However, the cell-intrinsic functions of IL1RAP in AML cells are largely unknown. Here, we show that targeting of IL1RAP via RNA interference, genetic deletion, or antibodies inhibits AML pathogenesis in vitro and in vivo, without perturbing healthy hematopoietic function or viability. Furthermore, we found that the role of IL1RAP is not restricted to the IL-1 receptor pathway, but that IL1RAP physically interacts with and mediates signaling and pro-proliferative effects through FLT3 and c-KIT, two receptor tyrosine kinases with known key roles in AML pathogenesis. Our study provides a new mechanistic basis for the efficacy of IL1RAP targeting in AML and reveals a novel role for this protein in the pathogenesis of the disease.


Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 3938-3938
Author(s):  
Eli I. Lev ◽  
Jing-fei Dong ◽  
Marcin Bujak ◽  
Khatira Aboulfatova ◽  
Neal S. Kleiman ◽  
...  

Abstract We and others have found that platelets play an important role in the recruitment of endothelial progenitor cells to sights of vascular injury. However, it is not clear whether the EPCs mature and differentiate to endothelial cells following recruitment to the vascular injury sites. In addition, there is limited in vivo data to support the role of EPCs in re-endothlialization following vascular injury. We conducted in vitro experiments to investigate the maturation of EPCs on platelet based-media and in vivo experiments to evaluate the recruitment of EPCs following vascular injury. In in vitro experiments human EPCs were isolated from donated buffy coats by magnetic microbeads and flow cytometry cell sorting using CD133 and VEGFR-2, respectively, as cell markers. Isolated viable EPCs (CD133+, VEGFR-2+ cells) were plated on human fibronectin or a monolayer of washed human platelets. Cell colonies were counted 7 days after plating and stained for the endothelial cell markers CD31 (PECAM-1) and CD144 (VE-cadherin). The mean number of colony-forming cells was 35±2.6 colonies/106 cells on platelets, which was significantly higher than 18±4.2 colonies/106 cells on fibronectin (n = 4, P<0.01). Apart from the difference in colony numbers, the EPC colonies grew faster on the platelet substrate, were larger, and had more spindle-shaped cells (Figure 1 - staining of EPC colonies for CD31 and CD144). In the in vivo experiments a model of transluminal injury to mouse femoral arteries was used. Femoral artery denudation was performed by 0.25-mm-diameter angioplasty guidewire. Injured femoral arteries were compared to the contra-lateral controls (uninjured), and were harvested 1.5 hours following the injury and immunostaining performed with an anti-VEGFR-2 antibody. Four experiments showed a markedly higher number of VEGFR-2+ cells in the artery that has undergone denudation. These experiments indicate that a media composed of platelets promotes the maturation and differentiation of EPCs. Furthermore, in vivo, EPCs are recruited early following vascular injury. Thus, homing, maturation, and differentiation of EPCs are mediated by platelets.


Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 46-46
Author(s):  
Loic Ysebaert ◽  
Mary Poupot ◽  
Yovan Sanchez-Ruiz ◽  
Camille Laurent ◽  
Guy Laurent ◽  
...  

Abstract Abstract 46 Introduction: CLL cells interact with many accessory cells in an environment mimicking that of normal mature B cells. Role of antigen, cytokines, adhesion pathways are critical for many aspects in the disease course (proliferation/survival, migration or homing, drug resistance, and presumably relapse). Nurse-like cells (NLC) belong to a monocytic-derived, bystander population among CLL lymph node and spleen stromal cells. Aim: To investigate the nature, functions, and location of NLC within CLL microenvironment. Methods: Gene expression profiles (GEP) from in vitro expanded NLC from patients (n=10) were produced and compared to those from normal CD14+ monocytes, M1-polarized macrophages, M2-polarized macrophages and tumor-associated macrophages (produced in the lab or downloaded from GEO datasets). Principal Component Analysis was used to categorize these five populations of cells and in-house-built GSEA software was used for functional interpretation of their relevant gene lists. Protein expression patterns were validated with multi-analyte ELISArray kits, proteome profiler arrays, flow cytometry (FC) or immunohistochemistry (IHC). Results: New insights into the physiopathological role of NLC in CLL are suggested from five lines of evidence: 1/a Òmonocytic gene signatureÓ (i.e. a set of 549 genes) is shared by the NLC and the monocyte subtypes. The genes over-represented in NLC vs normal monocytes pinpointed positive modulation of apoptotic cell clearance (scavenger, mannose and complement receptors, LXRalpha), lipid metabolism (Apolipoprotein E, PPAR signaling), extracellular matrix-receptor interactions (integrins, SPARC, Matrix MetalloProteinases) and actin cytoskeleton remodeling. 2/unsupervised clustering show that NLC represent an M2-skewed, TAM-like cell population. They down-regulate mRNA and proteins for classic M1 inflammatory markers (e.g. IL-1, IL-6, IL-12, COX2) while increase secretion of TGFbeta, IL-10, CCL17 and CCL22 soluble factors. 3/these and previously published observations suggest that B-CLL-to-NLC interactions may orchestrate immunosuppression in this disease. PBMCs from Òwatch and waitÓ CLL patients (all stage A/Rai 0, mutated IgVH, low risk cytogenetics profile) or healthy donors were stimulated with anti-CD3/CD28 beads + IL-2, either in standard RPMI+10% FCS or in conditioned medium (CM, after 14d CLL-NLC co-culture in vitro) and their proliferation/phenotype were compared after 2 weeks. Significant expansion of T cells with Treg (CD4+CD25+FoxP3+) phenotype was observed only from CLL PBMCs grown in conditioned medium (mean % Treg: 2.85 vs 3.05 in CM for normal PBMCs, and 1.54 vs 15.9 in CM for CLL PBMCs, P< 0.05). 4/although NLC make immune synapses with live B-CLL, they do not phagocytose them. Over-expression of CD47 (ÒdonÕt eat meÓ signal) by B-CLL cells (mfi= 3490 vs 2581 on normal cells, P< 0.05, n=18) may provide them with a protective signal against NLC. 5/from our GEP, flow cytometric and IHC analyses, we propose CD163 (classic M2 marker) as a reliable tool to identify NLC in vivo. Although in vitro, CLL cells can pervert healthy donor monocytes into NLC, only CLL-derived NLC are truly CD14+ CD163+. In vivo, CD163 staining reveals putative NLC in CLL lymph nodes(LN)/spleen sections but not in bone marrow. In LN from all patients, NLC reside in the subcapsular areas and line vessel structures, suggesting a role in CLL cells trafficking. Most interestingly, NLC infiltrate pseudofollicles structures only in a subset of cases. We will present updated IHC and clinical presentation correlation studies. Conclusions: Our results suggest that the role of NLC in CLL might be broader than initially thought. Beside of nursing and conferring drug resistance, NLC may also be crucial in the setting of immunosuppression, of CLL cells recruitment, and should thus be considered as therapeutic targets. Disclosures: Off Label Use: GA101 is not currently approved for CLL treatment.


2004 ◽  
Vol 15 (4) ◽  
pp. 1647-1655 ◽  
Author(s):  
Eui Kyun Park ◽  
Neil Warner ◽  
Yong-Sik Bong ◽  
David Stapleton ◽  
Ryu Maeda ◽  
...  

The Eph family of receptor tyrosine kinases regulates numerous biological processes. To examine the biochemical and developmental contributions of specific structural motifs within Eph receptors, wild-type or mutant forms of the EphA4 receptor were ectopically expressed in developing Xenopus embryos. Wild-type EphA4 and a mutant lacking both the SAM domain and PDZ binding motif were constitutively tyrosine phosphorylated in vivo and catalytically active in vitro. EphA4 induced loss of cell adhesion, ventro-lateral protrusions, and severely expanded posterior structures in Xenopus embryos. Moreover, mutation of a conserved SAM domain tyrosine to phenylalanine (Y928F) enhanced the ability of EphA4 to induce these phenotypes, suggesting that the SAM domain may negatively regulate some aspects of EphA4 activity in Xenopus. Analysis of double mutants revealed that the Y928F EphA4 phenotypes were dependent on kinase activity; juxtamembrane sites of tyrosine phosphorylation and SH2 domain-binding were required for cell dissociation, but not for posterior protrusions. The induction of protrusions and expansion of posterior structures is similar to phenotypic effects observed in Xenopus embryos expressing activated FGFR1. Furthermore, the budding ectopic protrusions induced by EphA4 express FGF-8, FGFR1, and FGFR4a. In addition, antisense morpholino oligonucleotide-mediated loss of FGF-8 expression in vivo substantially reduced the phenotypic effects in EphA4Y928F expressing embryos, suggesting a connection between Eph and FGF signaling.


2018 ◽  
Vol 11 (4) ◽  
pp. 330-346 ◽  
Author(s):  
João Alfredo Moraes ◽  
Ana Clara Frony ◽  
Pedro Barcellos-de-Souza ◽  
Marcel Menezes da Cunha ◽  
Thayanne Brasil Barbosa Calcia ◽  
...  

Exposition of neutrophils (polymorphonuclear neutrophils, PMNs) to bacterial products triggers exacerbated activation of these cells, increasing their harmful effects on host tissues. We evaluated the possibility of interfering with the classic immune innate responses of human PMNs exposed to bacterial endotoxin (lipopolysaccharide, LPS), and further stimulated with bacterial formyl peptide (N-formyl-methionine-leucine-phenylalanine, fMLP). We showed that the low- molecular-weight fucoidan (LMW-Fuc), a polysaccharide extracted from brown algae, attenuated the exacerbated activation induced by fMLP on LPS-primed PMNs, in vitro, impairing chemotaxis, NET formation, and the pro-survival and pro-oxidative effects. LMW-Fuc also inhibited the activation of canonical signaling pathways, AKT, bad, p47phox and MLC, activated by the exposition of PMN to bacterial products. The activation of PMN by sequential exposure to LPS and fMLP induced the release of L-selectin+ microparticles, which were able to trigger extracellular reactive oxygen species production by fresh PMNs and macrophages. Furthermore, we observed that LMW-Fuc inhibited microparticle release from activated PMN. In vivo experiments showed that circulating PMN-derived microparticles could be detected in mice exposed to bacterial products (LPS/fMLP), being downregulated in animals treated with LMW-Fuc. The data highlight the autocrine and paracrine role of pro-inflammatory microparticles derived from activated PMN and demonstrate the anti-inflammatory effects of LMW-Fuc on these cells.


1980 ◽  
Vol 239 (3) ◽  
pp. R326-R331
Author(s):  
S. A. Halbert ◽  
R. J. Bourdage ◽  
J. L. Boling ◽  
J. A. Ringo ◽  
R. J. Blandau

An optoelectronic instrument to record oviductal muscular activity in chronically instrumented animals was evaluated in in vitro and in vivo experiments. The intensity of red light transmitted through the oviduct was modulated by contractions of the oviductal wall producing an optical analog of the mechanical events. Accuracy of the analog was tested by Fourier analysis of signals from mechanical and optoelectronic transducers placed at the same site on the oviduct; the results validated the use of the optical device as a contraction event sensor. Contractions of the tubal mesenteries had less effect on the optical signal than on signals from extraluminal mechanical transducers. Optical and photographic recordings of luminal transport in exposed oviducts showed a correspondence of intraluminal movements to events in the optical contraction signal. This instrument does not alter tubal function, and thus it is an especially useful experimental tool to investigate the role of oviductal muscular activity in fertility.


Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 3445-3445
Author(s):  
Martin Bilban ◽  
Sherrie L. Otterbein ◽  
Emeka Ifedigbo ◽  
Keiji Enjyoji ◽  
Anny Usheva ◽  
...  

Abstract Carbon monoxide (CO) at low concentrations has generated recent interest due to its ability to modulate the inflammatory response associated with chronic graft rejection, vascular injury and septic shock. Both in vivo and in vitro CO can inhibit the expression of pro-inflammatory genes such as TNFα in macrophages while simultaneously increasing the expression of the anti-inflammatory cytokine IL-10. The mechanisms by which this occurs are still unclear. To better understand the mechanisms underlying the effects of CO, we employed the Affymetrix GeneChip technology to evaluate the time-dependent expression patterns of >12,000 genes in macrophages stimulated with bacterial endotoxin (LPS) in the presence or absence of a low concentration of CO previously demonstrated to evoke an anti-inflammatory response. We were particularly interested whether CO would, by itself, modulate in a specific manner the expression of proteins that might explain the anti-inflammatory effects observed following subsequent administration of endotoxin. RAW 264.7 murine macrophages were grown to 75% confluency and then exposed to CO (250 ppm) for 3 hr prior to administration of LPS (10 ng/ml). At 0, 15, 30, 60, 120 and 240 min thereafter, total RNA was isolated by standard methods and the RNA was then labeled and hybridized to U74Av2 GeneChips. Of >12,000 genes assessed, 116 of 270 that were LPS-responsive were affected by CO treatment. CO inhibited the majority of LPS-induced pro-inflammatory cytokines and acute phase proteins including expression of early growth response-1 (Egr-1), a transcription factor that serves as a central intermediary regulating many genes. Egr-1 was nearly completely inhibited by CO as was Egr-1-dependent expression of tissue factor (TF) and PAI-1. Treatment of cells with CO alone led to a rapid early increase in PPARγ, the expression of which was essential for the anti-inflammatory effects of CO. Inhibition of PPARγ using the selective chemical inhibitor GW9662 reversed the CO inhibitory effects on LPS-induced Egr-1 and TF expression. Correlative in vivo experiments in mice showed that CO pre-treatment blocked endotoxin-induced Egr-1 expression and decreased markers of lung inflammmation the effects of which were also lost with inhibition of PPARγ. Our analyses of gene expression patterns has led to the first molecular understanding of how treatment with CO, in this case by inducing PPARγ, blocks the pro-inflammatory response. These experiments provide novel insights into the mechanisms and pathophysiology of endotoxic shock and identify cellular targets by which CO mediates these cytoprotective effects.


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