scholarly journals Thrombospondin stimulates motility of human neutrophils.

1990 ◽  
Vol 111 (6) ◽  
pp. 3077-3086 ◽  
Author(s):  
P J Mansfield ◽  
L A Boxer ◽  
S J Suchard
Keyword(s):  
Monoclonal Antibody ◽  
Cell Types ◽  
Human Neutrophils ◽  
Heparin Binding ◽  
Directed Movement ◽  
Surface Receptors ◽  
Chemotactic Peptides ◽  
Heparin Binding Domain ◽  
High Concentrations ◽  
Priming Activity

Polymorphonuclear leukocytes (PMNs) migrate to sites of inflammation or injury in response to chemoattractants released at those sites. The presence of extracellular matrix (ECM) proteins at these sites may influence PMN accumulation at blood vessel walls and enhance their ability to move through tissue. Thrombospondin (TSP), a 450-kD ECM protein whose major proteolytic fragments are a COOH-terminal 140-kD fragment and an NH2-terminal heparin-binding domain (HBD), is secreted by platelets, endothelial cells, and smooth muscle cells. TSP binds specifically to PMN surface receptors and has been shown, in other cell types, to promote directed movement. TSP in solution at low concentrations (30-50 nM) "primed" PMNs for f-Met-Leu-Phe (fMLP)-mediated chemotaxis, increasing the response two- to fourfold. A monoclonal antibody against the HBD of TSP totally abolished this priming effect suggesting that the priming activity resides in the HBD of TSP. Purified HBD retains the priming activity of TSP thereby corroborating the antibody data. TSP alone, in solution at high concentrations (0.5-3.0 microM), stimulated chemotaxis of PMNs and required both the HBD and the 140-kD fragment of TSP. In contrast to TSP in solution, TSP bound to nitrocellulose filters in the range of 20-70 pmol stimulated random locomotion of PMNs. The number of PMNs migrating in response to bound TSP was approximately two orders of magnitude greater than the number of cells that exhibited chemotaxis in response to soluble TSP or fMLP. Monoclonal antibody C6.7, which recognizes an epitope near the carboxyl terminus of TSP, blocked migration stimulated by bound TSP, suggesting that the activity resides in this domain. Using proteolytic fragments, we demonstrated that bound 140-kD fragment, but not HBD, promoted migration of PMNs. Therefore, TSP released at injury sites, alone or in synergy with chemotactic peptides like fMLP, could play a role in directing PMN movement.

scholarly journals Role of the extracellular matrix protein thrombospondin in the early development of the mouse embryo.

1990 ◽  
Vol 111 (6) ◽  
pp. 2713-2723 ◽  
Author(s):  
K S O'Shea ◽  
L H Liu ◽  
L H Kinnunen ◽  
V M Dixit
Keyword(s):  
Extracellular Matrix ◽  
Matrix Protein ◽  
Inner Cell Mass ◽  
Cell Mass ◽  
Cell Types ◽  
Extracellular Matrix Protein ◽  
Heparin Binding ◽  
Cell Stage ◽  
Binding Domains ◽  
Heparin Binding Domain

The distribution of the extracellular matrix protein thrombospondin (TSP) in cleavage to egg cylinder staged mouse embryos and its role in trophoblast outgrowth from cultured blastocysts were examined. TSP was present within the cytoplasm of unfertilized eggs; in fertilized one- to four-cell embryos; by the eight-cell stage, TSP was also densely deposited at cell-cell borders. In the blastocyst, although TSP was present in all three cell types; trophectoderm, endoderm, and inner cell mass (ICM), it was enriched in the ICM and at the surface of trophectoderm cells. Hatched blastocysts grown on matrix-coated coverslips formed extensive trophoblast outgrowths on TSP, grew slightly less avidly on laminin, or on a 140-kD fragment of TSP containing its COOH terminus and putative cell binding domains. There was little outgrowth on the NH2 terminus heparin-binding domain. Addition of anti-TSP antibodies (but not GRGDS) to blastocysts growing on TSP strikingly inhibited outgrowth. Consistent with its early appearance and presence in trophoblast cells during implantation, TSP may play an important role in the early events involved in mammalian embryogenesis.

scholarly journals Myeloperoxidase-mediated modulation of chemotactic peptide binding to human neutrophils

Blood ◽  
1983 ◽  
Vol 61 (6) ◽  
pp. 1203-1207 ◽  
Author(s):  
TA Lane ◽  
GE Lamkin
Keyword(s):  
Human Neutrophils ◽  
Chemotactic Peptide ◽  
Chemotactic Migration ◽  
Saturation Control ◽  
Surface Receptors ◽  
Methionine Residue ◽  
Chemotactic Peptides ◽  
Apparent Decrease ◽  
20 Nm ◽  
Mediated Oxidation

Abstract Methionine-containing chemotactic peptides, such as formyl-methionyl- leucyl-phenylalanine (FMLP), are inactivated via a neutrophil-derived, myeloperoxidase-mediated oxidation of the methionine residue. We report that extracellular inactivation of FMLP by myeloperoxidase modulates the apparent binding of methionine-containing chemotactic peptides to their surface receptors. Inhibitors of myeloperoxidase enhanced FMLP binding. At subsaturating concentrations of 3H-FMLP (20 nM), 1 mM cyanide (KCN) increased the binding of 3H-FMLP to human neutrophils (PMN) by 51% +/- 12%. Similar increases occurred with 0.1 mM azide and 10 mM aminotriazole (ATZ). KCN had little effect on maximal 3H-FMLP binding to PMN at saturation (control-17,040 +/- 910 receptors/PMN; KCN- 16,820 +/- 1,940 receptors/PMN), but decreased the concentration of 3H- FMLP required to half-saturate the PMN receptors (control-39 +/- 3 nM; KCN-17 +/- 1 nM). ATZ gave similar results. The binding to PMN of the non-methionine-containing chemotactic peptide 125I-formyl-norleucyl- leucyl-phenylalanyl-norleucyl-tyrosyl-lysine (125I-FNLPNTL) was unaltered by KCN. Also, the binding of 3H-FMLP to myeloperoxidase- deficient PMN was unaltered by KCN. Both KCN and ATZ decreased the oxidation of FMLP by PMN. Finally, ATZ (but not KCN) enhanced the chemotactic migration of PMN in response to submaximal concentrations of FMLP. These studies show that intact PMN inactivate methionine- containing chemotactic peptides by a pathway that is sensitive to myeloperoxidase inhibitors and is absent in myeloperoxidase-deficient PMN. This action results in an apparent decrease in the affinity of the chemotactic peptide receptor for methionine-containing chemotactic peptides, which may modulate chemotatic events in inflammatory loci.

Thrombospondin-1 binds to polyhistidine with high affinity and specificity

2000 ◽  
Vol 347 (2) ◽  
pp. 469-473 ◽  
Author(s):  
Vijay K. VANGURI ◽  
Shuxia WANG ◽  
Svetlana GODYNA ◽  
Sripriya RANGANATHAN ◽  
Gene LIAU
Keyword(s):  
Solid Phase ◽  
Imidazole Ring ◽  
Binding Domain ◽  
Heparin Binding ◽  
Surface Receptors ◽  
High Affinity ◽  
Thrombospondin 1 ◽  
Heparin Binding Domain ◽  
Solid Phase Binding ◽  
And Migration

Thrombospondin-1 (TSP1) is a secreted trimeric glycoprotein of 450 kDa with demonstrated effects on cell growth, adhesion and migration. Its complex biological activity is attributed to its ability to bind to cell-surface receptors, growth factors and extracellular-matrix proteins. In this study, we used a 125I solid-phase binding assay to demonstrate that TSP1 binds specifically to proteins containing polyhistidine stretches. Based on studies with three different six-histidine-containing recombinant proteins, we derived an average dissociation constant of 5 nM. The binding of 125I-labelled TSP1 to these proteins was inhibited by peptides containing histidine residues, with the degree of competition being a function of the number of histidines within the peptide. Binding was not inhibited by excess histidine or imidazole, indicating that the imidazole ring is not sufficient for recognition by TSP1. Heparin was a potent inhibitor of binding with a Ki of 50 nM, suggesting that the heparin-binding domain of TSP1 may be involved in this interaction. This was confirmed by the ability of a recombinant heparin-binding domain of TSP1 to directly compete for TSP1 binding to polyhistidine-containing proteins. Affinity chromatography with a polyhistidine-containing peptide immobilized on agarose revealed that TSP1 in platelet releasates is the major polypeptide retained on the six-histidine-peptide column. We conclude that TSP1 contains a high-affinity binding site for polyhistidine and this is likely to be the molecular basis for the observed binding of TSP1 to histidine-rich glycoprotein. The possibility that other polyhistidine-containing proteins also interact with TSP1 warrants further study.

scholarly journals Myeloperoxidase-mediated modulation of chemotactic peptide binding to human neutrophils

Blood ◽  
1983 ◽  
Vol 61 (6) ◽  
pp. 1203-1207
Author(s):  
TA Lane ◽  
GE Lamkin
Keyword(s):  
Human Neutrophils ◽  
Chemotactic Peptide ◽  
Chemotactic Migration ◽  
Saturation Control ◽  
Surface Receptors ◽  
Methionine Residue ◽  
Chemotactic Peptides ◽  
Apparent Decrease ◽  
20 Nm ◽  
Mediated Oxidation

Methionine-containing chemotactic peptides, such as formyl-methionyl- leucyl-phenylalanine (FMLP), are inactivated via a neutrophil-derived, myeloperoxidase-mediated oxidation of the methionine residue. We report that extracellular inactivation of FMLP by myeloperoxidase modulates the apparent binding of methionine-containing chemotactic peptides to their surface receptors. Inhibitors of myeloperoxidase enhanced FMLP binding. At subsaturating concentrations of 3H-FMLP (20 nM), 1 mM cyanide (KCN) increased the binding of 3H-FMLP to human neutrophils (PMN) by 51% +/- 12%. Similar increases occurred with 0.1 mM azide and 10 mM aminotriazole (ATZ). KCN had little effect on maximal 3H-FMLP binding to PMN at saturation (control-17,040 +/- 910 receptors/PMN; KCN- 16,820 +/- 1,940 receptors/PMN), but decreased the concentration of 3H- FMLP required to half-saturate the PMN receptors (control-39 +/- 3 nM; KCN-17 +/- 1 nM). ATZ gave similar results. The binding to PMN of the non-methionine-containing chemotactic peptide 125I-formyl-norleucyl- leucyl-phenylalanyl-norleucyl-tyrosyl-lysine (125I-FNLPNTL) was unaltered by KCN. Also, the binding of 3H-FMLP to myeloperoxidase- deficient PMN was unaltered by KCN. Both KCN and ATZ decreased the oxidation of FMLP by PMN. Finally, ATZ (but not KCN) enhanced the chemotactic migration of PMN in response to submaximal concentrations of FMLP. These studies show that intact PMN inactivate methionine- containing chemotactic peptides by a pathway that is sensitive to myeloperoxidase inhibitors and is absent in myeloperoxidase-deficient PMN. This action results in an apparent decrease in the affinity of the chemotactic peptide receptor for methionine-containing chemotactic peptides, which may modulate chemotatic events in inflammatory loci.

Depletion of pulmonary EC-SOD after exposure to hyperoxia

2002 ◽  
Vol 283 (4) ◽  
pp. L777-L784 ◽  
Author(s):  
Tim D. Oury ◽  
Lisa M. Schaefer ◽  
Cheryl L. Fattman ◽  
Augustine Choi ◽  
Karen E. Weck ◽  
...  
Keyword(s):  
Bronchoalveolar Lavage Fluid ◽  
Lavage Fluid ◽  
Binding Domain ◽  
Extracellular Superoxide Dismutase ◽  
Pulmonary Injury ◽  
Heparin Binding ◽  
Cell Surfaces ◽  
Heparin Binding Domain ◽  
High Concentrations ◽  
Alveolar Parenchyma

Extracellular superoxide dismutase (EC-SOD) is highly expressed in lung tissue. EC-SOD contains a heparin-binding domain that is sensitive to proteolysis. This heparin-binding domain is important in allowing EC-SOD to exist in relatively high concentrations in specific regions of the extracellular matrix and on cell surfaces. EC-SOD has been shown to protect the lung against hyperoxia in transgenic and knockout studies. This study tests the hypothesis that proteolytic clearance of EC-SOD from the lung during hyperoxia contributes to the oxidant-antioxidant imbalance that is associated with this injury. Exposure to 100% oxygen for 72 h resulted in a significant decrease in EC-SOD levels in the lungs and bronchoalveolar lavage fluid of mice. This correlated with a significant depletion of EC-SOD from the alveolar parenchyma as determined by immunofluorescence and immunohistochemistry. EC-SOD mRNA was unaffected by hyperoxia; however, there was an increase in the ratio of proteolyzed to uncut EC-SOD after hyperoxia, which suggests that hyperoxia depletes EC-SOD from the alveolar parenchyma by cutting the heparin-binding domain. This may enhance hyperoxic pulmonary injury by altering the oxidant-antioxidant balance in alveolar spaces.

scholarly journals A highly specific monoclonal antibody against monkeypox virus detects the heparin binding domain of A27

Virology ◽  
2014 ◽  
Vol 464-465 ◽  
pp. 264-273 ◽  
Author(s):  
Laura J. Hughes ◽  
Jason Goldstein ◽  
Jan Pohl ◽  
Jay W. Hooper ◽  
R. Lee Pitts ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
Binding Domain ◽  
Heparin Binding ◽  
Specific Monoclonal Antibody ◽  
Monkeypox Virus ◽  
Heparin Binding Domain

scholarly journals A heparin-binding domain from N-CAM is involved in neural cell-substratum adhesion.

1986 ◽  
Vol 102 (2) ◽  
pp. 403-412 ◽  
Author(s):  
G J Cole ◽  
L Glaser
Keyword(s):  
Monoclonal Antibody ◽  
Heparan Sulfate ◽  
Cell Attachment ◽  
Limited Proteolysis ◽  
Neural Cell ◽  
Binding Domain ◽  
Retinal Cell ◽  
Heparin Binding ◽  
Retinal Cells ◽  
Heparin Binding Domain

Cell-substratum adhesion in the embryonic chicken nervous system has been shown to be mediated in part by a 170,000-mol-wt polypeptide that is a component of adherons. Attachment of retinal cells to the 170,000-mol-wt protein is inhibited by the C1H3 monoclonal antibody and by heparan sulfate (Cole, G. J., D. Schubert, and L. Glaser, 1985, J. Cell Biol., 100:1192-1199). In the present study we have demonstrated that the 170,000-mol-wt C1H3 polypeptide is immunologically identical to the neural cell adhesion molecule N-CAM, and that the 170,000-mol-wt component of N-CAM is preferentially secreted by cells as a component of adherons. We have identified a monoclonal antibody, designated B1A3, that inhibits heparin binding to N-CAM and cell-to-substratum adhesion. A 25,000-mol-wt heparin (heparan sulfate)-binding domain of N-CAM has been identified by limited proteolysis, and this fragment promotes cell attachment when bound to glass surfaces. The fragment also partially inhibits cell binding to adherons when bound to retinal cells, and the B1A3 monoclonal antibody inhibits retinal cell attachment to substrata composed of intact N-CAM or the heparin-binding domain. These data are the first evidence that N-CAM is a multifunctional protein that contains both cell-and heparin (heparan sulfate)-binding domains.

1985 Kreshover lecture. Molecular Factors Influencing Neutrophil Defects in Periodontal Disease

1986 ◽  
Vol 65 (12) ◽  
pp. 1379-1391 ◽  
Author(s):  
R.J. Genco ◽  
T.E. Van Dyke ◽  
M.J. Levine ◽  
R.D. Nelson ◽  
M.E. Wilson
Keyword(s):  
Cervical Lymphadenopathy ◽  
Human Neutrophils ◽  
Surface Receptors ◽  
Periodontal Infection ◽  
Chemotactic Peptides ◽  
Blood Neutrophils ◽  
Localized Juvenile Periodontitis ◽  
A Cell ◽  
Crevicular Fluid ◽  
Neutrophil Surface

Major advances in our understanding of the role of the neutrophil in host defense against periodontal organisms have been made through studies of localized juvenile periodontitis (LJP). Several.lines of evidence suggest that LJP is an infectious process closely associated with Actinobacillus (Haemophilus) actinomycetemcomitans as a causative agent, although other organisms may also participate. The immunologic profile of LJP patients suggests that a cell-associated neutrophil locomotory dysfunction is a key underlying immunodeficiency resulting in increased susceptibility to periodontal infection. In addition, LJP patients often exhibit cervical lymphadenopathy and IgG-hypergammaglobulinemia, and a markedly elevated antibody response to the infecting organism, A. actinomycetemcomitans, is found in the serum and crevicular fluid of most patients. Evaluation of the locomotory properties of LJP neutrophils shows that random migration and chemokinesis are normal; however, about 70% of the LJP patients suffer from a defect in chemotaxis, with their neutrophils responding poorly to bacterial chemotaetic factors, synthetic chemotactic peptides, and complement fragments (C5a). Depressed chemotaxis of LJP neutrophils is paralleled by their reduced capacity to bind the synthetic chemotactic peptide N-formylmethionylleucylphenylalanine (FMLP), as well as C5a. Furthermore, there is a reduction in the amount of glycoprotein 110, a neutrophil membrane matrix component and differentiation antigen which is associated with FMLP- and possibly also C5a-mediated chemotaxis. Reduction ofC5a and of FMLP ligand binding, decreased expression of GP-110, and reduced neutrophil chemotaxis are consistent with a stem cell maturation error in LJP patients. This is further supported by studies demonstrating increased expression of CR2, the C3d/EBV receptor, on peripheral blood neutrophils of LJP patients. CR2 receptors are normally present on immature human neutrophils but are lost during the maturation process. These alterations in neutrophil surface components and their reduced chemotaxis may result from a genetically determined abnormality. Studies demonstrating the familial nature of both the neutrophil chemotactic disorder and the clinical entity represented by localized juvenile periodontitis point to a strong role for genetic determinants in the disease which affect neutrophil surface receptors.

Nanotheranostic agents for neurodegenerative diseases

2020 ◽  
Vol 4 (6) ◽  
pp. 645-675
Author(s):  
Parasuraman Padmanabhan ◽  
Mathangi Palanivel ◽  
Ajay Kumar ◽  
Domokos Máthé ◽  
George K. Radda ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Neurodegenerative Diseases ◽  
Cell Types ◽  
Specific Cell ◽  
Ageing Population ◽  
Target Tissue ◽  
Therapeutic Approaches ◽  
Surface Receptors ◽  
Theranostic Agents ◽  
Preclinical Animal Models

Neurodegenerative diseases (NDDs), including Alzheimer's disease (AD) and Parkinson's disease (PD), affect the ageing population worldwide and while severely impairing the quality of life of millions, they also cause a massive economic burden to countries with progressively ageing populations. Parallel with the search for biomarkers for early detection and prediction, the pursuit for therapeutic approaches has become growingly intensive in recent years. Various prospective therapeutic approaches have been explored with an emphasis on early prevention and protection, including, but not limited to, gene therapy, stem cell therapy, immunotherapy and radiotherapy. Many pharmacological interventions have proved to be promising novel avenues, but successful applications are often hampered by the poor delivery of the therapeutics across the blood-brain-barrier (BBB). To overcome this challenge, nanoparticle (NP)-mediated drug delivery has been considered as a promising option, as NP-based drug delivery systems can be functionalized to target specific cell surface receptors and to achieve controlled and long-term release of therapeutics to the target tissue. The usefulness of NPs for loading and delivering of drugs has been extensively studied in the context of NDDs, and their biological efficacy has been demonstrated in numerous preclinical animal models. Efforts have also been made towards the development of NPs which can be used for targeting the BBB and various cell types in the brain. The main focus of this review is to briefly discuss the advantages of functionalized NPs as promising theranostic agents for the diagnosis and therapy of NDDs. We also summarize the results of diverse studies that specifically investigated the usage of different NPs for the treatment of NDDs, with a specific emphasis on AD and PD, and the associated pathophysiological changes. Finally, we offer perspectives on the existing challenges of using NPs as theranostic agents and possible futuristic approaches to improve them.

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