scholarly journals Heterogeneous distribution of antithrombin-binding sites in rat brain heparan sulphate proteoglycans

1991 ◽  
Vol 280 (2) ◽  
pp. 393-397 ◽  
Author(s):  
A A Horner
Keyword(s):  
Binding Sites ◽  
Heparan Sulphate ◽  
Deae Cellulose ◽  
Reciprocal Relationship ◽  
Rat Skin ◽  
Heterogeneous Distribution ◽  
Site Distribution ◽  
Heparan Sulphate Proteoglycans ◽  
High Binding Affinity

Heparan sulphates with high binding affinity for antithrombin (HA-HS), labelled in vivo with [35S]sulphate, were extracted from rat brains and purified by chromatography on DEAE-cellulose and on antithrombin-agarose. HA-HS proteoglycans (HA-HSPG) were then separated from HA-HS chains on Sepharose CL-6B. The total HA-HSPG product was rechromatographed on antithrombin-agarose. Six HA-HSPG subfractions with differing degrees of affinity for antithrombin were recovered and treated with NaOH to release their chains. Rechromatography of these six 35S-labelled HS chain preparations on antithrombin-agarose showed that their proportions of chains with no affinity for antithrombin (NA-HS chains) ranged from 36 to 71%. There was a reciprocal relationship between the proportion of NA-HS chains in each HA-HSPG subfraction and the degree of affinity for antithrombin of the rest of its chains (assessed relative to 3H-labelled HA-heparin chains with which they were co-chromatographed). Similar characteristics of antithrombin-binding-site distribution apply to HA-heparin proteoglycans from rat skin studied previously [Horner (1987) Biochem. J. 244, 693-698]. The data suggest that the sites at which 3-O-sulphation of some glucosamine N-sulphate residues occurs in the Golgi complex of brain cells (probably endothelial cells) which synthesize HA-HSPGs (as in mast cells, which synthesize HA-heparin PGs) are distributed sparsely but not randomly.

IN VIVO INTERACTION BETWEEN HUMAN PLATELET FACTOR 4 (PF4) AND PROTAMINE SULPHATE (PS) IN THE PRESENCE OF DIFFERENT GLYCOSAMI-NOGLYCANS (GAGs)

1987 ◽  
Author(s):  
G Celia ◽  
M Prosdocimi ◽  
A A Sasahara
Keyword(s):  
Binding Sites ◽  
Anticoagulant Activity ◽  
Heparan Sulphate ◽  
The Body ◽  
Platelet Factor ◽  
Protamine Sulphate ◽  
Peak Release ◽  
Few Data ◽  
The Relationship

Anti-heparin substances, like PF4 or PS, have been studied largely in reference to their ability to neutralize the anticoagulant activity of heparin. On the other hand, few data are available concerning the relationship between GAGs and anti-heparin proteins clearance. We studied the action of PS on human PF4 kinetics in anesthetized rabbits pre-treated with heparin (H, 1000 I.U.), heparan sulphate (HS, 30 mg) and derma tan sulphate (DS, 30 mg). PF4 (given at a dose of 45 μgAg) disappearance reflected its different affinity for the GAGs, with the following half lives (min): control 2.09±0.28, H 14.80±1.47, HS 10.90±1.91, DS 6.87±0.68. Moreover, circulating PF4 (ng/ml) at 1 min was as follows: control 109±8, H 873±134, HS 751±34 and DS 473±15. In another group of H pre-treated rabbits, a bolus injection of PS (10 or 20 mg) caused an immediate disappearance in th.e circulating plasma PF4, from 900±23 ng/ml (1 min after PF4) to 75±11 ng/ml (1 min after 10 mg PS). However, a subsequent H injection 10 min after PS induced a peak release of PF4 (520±21 ng/ml). In a further group of animals pre-treated with HS, the interaction between PS and PF4 was similar to that observed after H treatment. In the last group, pre-treated with DS, the interaction between PF4 and PS was also similar, however, unexpectedly, when 20 mg of PS were given a subsequent bolus of H did not produce any increase of circulating PF4We suggest that PS displaces PF4 from its binding sites on H or HS, thus allowing its uptake by the storage sites in the body, from where it can be harvested again after the subsequent H administration. In the presence of DS again PS is able to displace PF4, however the remaining excess of PS could neutralize the subsequent H injection, thus rendering it unable to induce PF4 release.

118. CHARACTERISATION OF HEPARAN SULPHATE PROTEOGLYCANS IN THE MATURING CUMULUS OOCYTE COMPLEX

2009 ◽  
Vol 21 (9) ◽  
pp. 37
Author(s):  
L. N. Watson ◽  
M. Sasseville ◽  
R. B. Gilchrist ◽  
D. L. Russell
Keyword(s):  
Growth Factors ◽  
Growth Factor ◽  
Cell Surface ◽  
Transforming Growth Factor ◽  
Heparan Sulphate ◽  
Cumulus Cells ◽  
Receptor Interaction ◽  
Heparan Sulphate Proteoglycans ◽  
Tgfβ Superfamily

Many growth factors including members of the transforming growth factor beta (TGFβ) superfamily and epidermal growth factor (Egf)-like ligands signal via interactions with heparan sulphate proteoglycans (HSPGs). Cell surface HSPGs can act by sequestering ligands at their site of action, by presenting a ligand to its signalling receptor, or by preventing ligand-receptor interaction. The oocyte secreted factors (OSF) growth differentiation factor 9 and bone morphogenetic protein 15 are members of the TGFβ superfamily that act selectively on cumulus cells. Conversely Egf-like ligands are secreted by mural granulosa cells and transmit LH-induced signals to cumulus cells. We investigated the possibility that HSPGs contribute to the spatially restricted responses these signals exert on cumulus cells. Syndecan-1 and Glypican-1 are cell surface HSPGs that are involved in numerous biological processes, including growth factor regulation, cell proliferation and differentiation. Microarray analysis showed Syndecan-1 and Glypican-1 mRNA expression induced 6-fold (P=10-9) and 3-fold (P=10-7) respectively in Egf+FSH stimulated cumulus oocyte complexes (COCs). Furthermore, Syndecan-1 and Glypican-1 mRNA were induced 27- and 16-fold respectively in COCs after hCG treatment of mice. Syndecan-1 and Glypican-1 protein was localised specifically to the COC through immunohistochemical analysis. In Vitro Maturation (IVM) of oocytes is a valuable alternative to gonadotropin mediated superovulation, but IVM COCs are less competent than those matured in vivo. Several components of the COC have been shown to be altered in IVM, including the chondroitin sulphate proteoglycan Versican. COCs from mice that underwent IVM in the presence of Egf+FSH and cilostamide for 16 hours had >16 fold reduced mRNA for Syndecan-1 when compared with In Vivo matured COCs. The lack of Syndecan-1 in IVM COCs could reduce signalling capacity of growth factors including OSFs. This may contribute to the reduced capacity of IVM oocytes to fertilise and produce a healthy embryo, and ultimately, a healthy offspring.

scholarly journals Engineered mutants of HGF/SF with reduced binding to heparan sulphate proteoglycans, decreased clearance and enhanced activity in vivo

1998 ◽  
Vol 8 (3) ◽  
pp. 125-135 ◽  
Author(s):  
Guido Hartmann ◽  
Terence Prospero ◽  
Volker Brinkmann ◽  
Öemil Ozcelik ◽  
Greg Winter ◽  
...  
Keyword(s):  
Heparan Sulphate ◽  
Enhanced Activity ◽  
Heparan Sulphate Proteoglycans

Interaction of spironolactone with rat skin androgen receptor

1979 ◽  
Vol 57 (7) ◽  
pp. 1042-1046 ◽  
Author(s):  
Andrée Boisselle ◽  
France T. Dionne ◽  
Roland R. Tremblay
Keyword(s):  
Androgen Receptor ◽  
Binding Sites ◽  
Competitive Inhibition ◽  
Male Rats ◽  
Affinity Constant ◽  
Dorsal Skin ◽  
Rat Skin ◽  
Number Of Binding Sites ◽  
Rat Prostate

Some characteristics of the dorsal skin cytoplasmic androgen receptor (AR) have been studied in male rats. The affinity constant, the binding specificity, and the sedimentation profile of the receptor have been found to be similar to the rat prostate AR. The measurement of the number of binding sites in various hormonal conditions (deprivation) led to the conclusion that this receptor was largely occupied by endogeneous hormones from gonadal and (or) adrenal sources. Administration of spironolactone or canrenone to 7-day-castrated rats was accompanied by a rapid and drastic decrease of available binding sites. This diminution was ascribed to the competitive inhibition of canrenone, the active in vivo metabolite of spironolactone. It is postulated that the antiandrogenic action of spironolactone, at the skin level, is mediated by canrenone which inhibits the formation of specific testosterone and (or) 5α-dihydrotestosterone receptor complex in cytoplasm and consequently in nuclei.

scholarly journals Studies on the incorporation of [U-14C]glucose and [35S]sulphate into the acid glycosaminoglycans of neonatal rat skin

1970 ◽  
Vol 119 (5) ◽  
pp. 885-893 ◽  
Author(s):  
T. E. Hardingham ◽  
C. F. Phelps
Keyword(s):  
Uronic Acid ◽  
Heparan Sulphate ◽  
Neonatal Rat ◽  
Rat Skin ◽  
Acid Biosynthesis ◽  
Keratan Sulphate ◽  
Sulphated Glycosaminoglycans ◽  
Acid Glycosaminoglycan ◽  
Acid Glycosaminoglycans

1. The incorporation of [35S]sulphate in vivo into the acid-soluble intermediates extracted from young rat skin showed three sulphated hexosamine-containing components. 2. The rates of synthesis of these components were determined in vivo by measuring the incorporation of radioactivity from [U-14C]glucose into their isolated hexosamine moieties. 3. The incorporation of radioactivity from [U-14C]glucose into the isolated hexosamine and uronic acid moieties of the acid glycosaminoglycans was also measured. These results, combined with those obtained on the intermediary pathways of hexosamine and uronic acid biosynthesis previously determined in this tissue, indicated that the acid-soluble sulphated hexosamine-containing components were not precursors of the sulphated hexosamine found in the acid glycosaminoglycans. 4. The rates of synthesis of the acid glycosaminoglycan fractions were calculated from the incorporation of radioactivity from [U-14C]glucose into the hexosamine moiety. The sulphated components containing principally dermatan sulphate, chondroitin 6-sulphate and in smaller amounts, chondroitin 4-sulphate, heparan sulphate and heparin appeared to be turning over about twice as rapidly as hyaluronic acid and about four times as rapidly as the small keratan sulphate fraction. The relative rates of synthesis of the sulphated glycosaminoglycans were calculated from the incorporation of [35S]sulphate and were in agreement with those from 14C-labelling studies.

scholarly journals Fibroblast growth factors share binding sites in heparan sulphate

2005 ◽  
Vol 389 (1) ◽  
pp. 145-150 ◽  
Author(s):  
Johan KREUGER ◽  
Per JEMTH ◽  
Emil SANDERS-LINDBERG ◽  
Liat ELIAHU ◽  
Dina RON ◽  
...  
Keyword(s):  
Growth Factors ◽  
Sequence Analysis ◽  
Binding Sites ◽  
Heparan Sulphate ◽  
Fibroblast Growth Factors ◽  
Fibroblast Growth ◽  
Cellular Targeting ◽  
Selective Modulation ◽  
Comprehensive Survey ◽  
Heparan Sulphate Proteoglycans

HS (heparan sulphate) proteoglycans bind secreted signalling proteins, including FGFs (fibroblast growth factors) through their HS side chains. Such chains contain a wealth of differentially sulphated saccharide epitopes. Whereas specific HS structures are commonly believed to modulate FGF-binding and activity, selective binding of defined HS epitopes to FGFs has generally not been demonstrated. In the present paper, we have identified a series of sulphated HS octasaccharide epitopes, derived from authentic HS or from biosynthetic libraries that bind with graded affinities to FGF4, FGF7 and FGF8b. These HS species, along with previously identified oligosaccharides that interact with FGF1 and FGF2, constitute the first comprehensive survey of FGF-binding HS epitopes based on carbohydrate sequence analysis. Unexpectedly, our results demonstrate that selective modulation of FGF activity cannot be explained in terms of binding of individual FGFs to specific HS target epitopes. Instead, different FGFs bind to identical HS epitopes with similar relative affinities and low selectivity, such that the strength of these interactions increases with increasing saccharide charge density. We conclude that FGFs show extensive sharing of binding sites in HS. This conclusion challenges the current notion of specificity in HS–FGF interactions, and instead suggests that a set of common HS motifs mediates cellular targeting of different FGFs.

scholarly journals Hoxb1 Enhancer and Control of Rhombomere 4 Expression: Complex Interplay between PREP1-PBX1-HOXB1 Binding Sites

2005 ◽  
Vol 25 (19) ◽  
pp. 8541-8552 ◽  
Author(s):  
Elisabetta Ferretti ◽  
Francisco Cambronero ◽  
Stefan Tümpel ◽  
Elena Longobardi ◽  
Leanne M. Wiedemann ◽  
...  
Keyword(s):  
Protein Interactions ◽  
Binding Sites ◽  
Binding Activity ◽  
Regulatory Activity ◽  
Inhibitory Effects ◽  
Transgenic Embryos ◽  
And Control ◽  
High Binding Affinity

ABSTRACT The Hoxb1 autoregulatory enhancer directs segmental expression in vertebrate hindbrain. Three conserved repeats (R1, R2, and R3) in the enhancer have been described as Pbx-Hoxb1 (PH) binding sites, and one Pbx-Meinox (PM) binding site has also been characterized. We have investigated the importance and relative roles of PH and PM binding sites with respect to protein interactions and in vivo regulatory activity. We have identified a new PM site (PM2) and found that it cooperates with the R3 PH site to form ternary Prep1-Pbx1-Hoxb1 complexes. In vivo, the combination of the R3 and PM2 sites is sufficient to mediate transgenic reporter activity in the developing chick hindbrain. In both chicken and mouse transgenic embryos, mutations of the PM1 and PM2 sites reveal that they cooperate to modulate in vivo regulatory activity of the Hoxb1 enhancer. Furthermore, we have shown that the R2 motif functions as a strong PM site, with a high binding affinity for Prep1-Pbx1 dimers, and renamed this site R2/PM3. In vitro R2/PM3, when combined with the PM1 and R3 motifs, inhibits ternary complex formation mediated by these elements and in vivo reduces and restricts reporter expression in transgenic embryos. These inhibitory effects appear to be a consequence of the high PM binding activity of the R2/PM3 site. Taken together, our results demonstrate that the activity of the Hoxb1 autoregulatory enhancer depends upon multiple Prep1-Pbx1 (PM1, PM2, and PM3) and Pbx1-Hoxb1 (R1 and R3) binding sites that cooperate to modulate and spatially restrict the expression of Hoxb1 in r4 rhombomere.

A 3.5-Second Phenomenon in Haemostasis

1973 ◽  
Vol 30 (02) ◽  
pp. 363-370
Author(s):  
D Thilo ◽  
E Böhm
Keyword(s):  
Bleeding Time ◽  
Rat Skin ◽  
Fibrin Formation ◽  
Bleeding Area ◽  
Platelet Thrombus ◽  
Platelet Aggregates ◽  
Primary Platelet ◽  
System Mechanism

SummaryExperiments with injury of the abdominal rat skin were carried out to examine the haemostatic system mechanism in vivo after zero to 30 seconds bleeding time. In the bleeding area only a few platelet aggregates could be found with no primary platelet thrombus. After 3.5 second bleeding time the first fibrin strands have been observed at the site of injury. The hypothesis is put forward that there is a very fast reacting haemostatic mechanism which results in the fibrin formation already at 3.5 seconds.

Pharmacological treatment with L-DOPA may reduce striatal dopamine transporter binding in in vivo imaging studies

2016 ◽  
Vol 55 (01) ◽  
pp. 21-28 ◽  
Author(s):  
C. Antke ◽  
H. Hautzel ◽  
H.-W. Mueller ◽  
S. Nikolaus
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Binding Sites ◽  
Human Subjects ◽  
Synaptic Cleft ◽  
Presynaptic Terminal ◽  
Imaging Studies ◽  
Psychiatric Conditions ◽  
Da Release

SummaryNumerous neurologic and psychiatric conditions are treated with pharmacological compounds, which lead to an increase of synaptic dopamine (DA) levels. One example is the DA precursor L-3,4-dihydroxyphenylalanine (L-DOPA), which is converted to DA in the presynaptic terminal. If the increase of DA concentrations in the synaptic cleft leads to competition with exogenous radioligands for presynaptic binding sites, this may have implications for DA transporter (DAT) imaging studies in patients under DAergic medication.This paper gives an overview on those findings, which, so far, have been obtained on DAT binding in human Parkinson’s disease after treatment with L-DOPA. Findings, moreover, are related to results obtained on rats, mice or non-human primates. Results indicate that DAT imaging may be reduced in the striata of healthy animals, in the unlesioned striata of animal models of unilateral Parkinson’s disease and in less severly impaired striata of Parkinsonian patients, if animal or human subjects are under acute or subchronic treatment with L-DOPA. If also striatal DAT binding is susceptible to alterations of synaptic DA levels, this may allow to quantify DA reuptake in analogy to DA release by assessing the competition between endogenous DA and the administered exogenous DAT radioligand.

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