Presence of oestrogen receptors in human blood mononuclear cells and thymocytes

1986 ◽  
Vol 112 (3) ◽  
pp. 409-414 ◽  
Author(s):  
J. J. A. M. Weusten ◽  
M. A. Blankenstein ◽  
F. H.J. Gmelig-Meyling ◽  
H.J. Schuurman ◽  
L. Kater ◽  
...  

Abstract. We studied oestrogen binding sites in blood mononuclear cells from healthy blood donors, patients with leukaemia or systemic lupus erythematosus, and in thymocytes, using the dextran-coated charcoal assay and Scatchard analysis of binding data. Using 3H-labelled oestradiol as ligand, inaccurate results were obtained which could be related to the low amounts of binding sites. Using 125I-labelled ligand, saturable oestradiol binding sites could be demonstrated in low amount (mean value 2.1 fmol/mg of cytosolic protein) and high affinity (mean Kd value 0.26 nm; mean Ka value 3.85 × 109 m−1). The binding could be inhibited by unlabelled oestradiol but not with oestrone, dihydrotestosterone, cortisol and the progestin-receptor ligand Org 2058. We conclude that blood mononuclear cells and thymocytes contain true oestrogen receptors. This conclusion supports current hypotheses on the involvement of such receptors in oestrogen-mediated modulation of the immune system.

1996 ◽  
Vol 313 (2) ◽  
pp. 537-541 ◽  
Author(s):  
Denis REYNAUD ◽  
Peter DEMIN ◽  
Cecil R. PACE-ASCIAK

Hepoxilins have been shown to release calcium from intracellular stores in human neutrophils [Dho, Grinstein, Corey, Su and Pace-Asciak (1990) Biochem. J. 266, 63-68; Laneuville, Reynaud, Grinstein, Nigam and Pace-Asciak (1993) Biochem. J. 295, 393-397]. In this paper we report that tritium-labelled hepoxilin A3 (8S) binds to broken neutrophil membranes in a time-, substrate- and temperature-dependent fashion. Specific binding was displaced with unlabelled hepoxilin A3. Specific binding was greatest at 37 °C. Competitive binding was best observed with unlabelled hepoxilin A3 (8S); the glutathione conjugate, HxA3-C (8S or 8R), or 12(S)-hydroxyeicosatetraenoic acid was less active. Similarly inactive in displacing the bound radiolabelled hepoxilin A3 was leukotriene B4 as well as a variety of prostaglandins and thromboxane B2. Formylmethionyl-leucylphenylalanine was similarly inactive in competing for the hepoxilin binding sites. Specific binding was inhibited by pretreatment of the broken membranes during 30 min at 37 °C with proteinase K, while specific binding of the intact cells was unaffected. Scatchard analysis of binding data revealed a single population of binding sites with apparent KD and Bmax. of 79.3±9.1 nM and 8.86±1.4 pmol/ml per 2×106 cells (±S.E.M.) respectively reflecting approx. 2.67×106 sites/cell. These results demonstrate for the first time that neutrophils contain specific binding sites to hepoxilin A3.


1977 ◽  
Author(s):  
S. Heptinstall

Extracellular calcium ions are required for platelets to aggregate in response to various aggregating agents. Although magnesium ions can sometimes stimulate aggregation they only do so when a small amount of calcium is present. The calcium bound to washed human platelets suspended in buffered saline containing 0-200μM+5CaCl2 depends upon the extracellular calcium concentration. Scatchard analysis of the binding data suggests that a few (0,8 × 106) relatively high affinity (K = 85,000) calcium binding sites are present on each platelet. When 2.5mM MgCl2 is included in the saline suspensions the calcium bound to the platelets is only reduced at the higher calcium concentrations. Magnesium ions do not displace the tightly bound calcium. It is suggested that these specific calcium binding sites are involved in platelet aggregation.


Lupus ◽  
2019 ◽  
Vol 28 (3) ◽  
pp. 359-364 ◽  
Author(s):  
F Zheng ◽  
D Tang ◽  
H Xu ◽  
Y Xu ◽  
W Dai ◽  
...  

Aim The aim of this paper is to explore the expression of 6-methyladenine (6mA) DNA and to elucidate its gene regulation role in systemic lupus erythematosus (SLE). Methods Twenty SLE patients and 20 normal control healthy individuals (HCs) were included in this study. Genomic DNA was isolated from peripheral blood mononuclear cells and subsequently underwent 6mA-immunoprecipitation-sequencing (6mA-IP-Seq) after DNA quality control and 6mA precipitation. Bioinformation analysis was applied to the raw data comparing 6mA levels between SLE patients and HCs. Results We identified 5462 hypermethylation and 431 hypomethylation genes in PBMCs of individuals with SLE, which indicated that a high level of 6mA participates in the pathogenesis of SLE. Gene ontology analysis revealed that hypermethylation genes might regulate the inflammatory process, which has been well documented in the pathogenesis of SLE. Conclusion 6mA may be involved in the initial development of SLE, which may lead to its potential use as an early diagnostic marker and therapeutic target.


1981 ◽  
Vol 91 (3) ◽  
pp. 848-853 ◽  
Author(s):  
P V Byrne ◽  
L J Guilbert ◽  
E R Stanley

CSF-1 is a subclass of the colony-stimulating factors that specifically stimulates the growth of mononuclear phagocytes. We used the binding of 125I-CSF-1 at 0 degrees C by single cell suspensions from various murine tissues, in conjunction with radioautography, to determine the frequency of binding cells, their identity, and the number of binding sites per binding cell. For all tissues examined, saturation of binding sites was achieved within 2 h at 2--3 x 10(-10) M 125I-CSF-1. The binding was irreversible and almost completely blocked by a 2 h preincubation with 5 x 10(-10) M CSF-1. 125I-CSF-1 binding was exhibited by 4.3% of bone marrow cells, 7.5% of blood mononuclear cells, 2.4% of spleen cells, 20.5% of peritoneal cells, 11.8% of pulmonary alveolar cells and 0.4% of lymph node cells. Four morphologically distinguishable cell types bound 125I-CSF-1: blast cells; mononuclear cells with a ratio of nuclear to cytoplasmic area (N/C) greater than 1; cells with indented nuclei; and mononuclear cells with N/C less than or equal to 1. No CSF-1 binding cells were detected among blood granulocytes or thymus cells. Bone marrow promyelocytes, myelocytes, neutrophilic granulocytes, eosinophilic granulocytes, nucleated erythroid cells, enucleated erythrocytes, and megakaryocytes also failed to bind. The frequency distribution of grain counts per cell for blood mononuclear cells was homogenous. In contrast, those for bone marrow, spleen, alveolar, and peritoneal cells were heterogeneous. The monocytes in blood or bone marrow (small cells, with either indented nuclei or with N/C greater than 1) were relatively uniformly labeled, possessing approximately 3,000 binding sites per cell. Larger binding cells (e.g., alveolar cells) may possess higher numbers of receptors. It is concluded that CSF-1 binding is restricted to mononuclear phagocytic cells and their precursors and that it can be used to identify both mature and immature cells of this series.


1981 ◽  
Author(s):  
P Silber ◽  
T H Finlay

The effect of ristocetin on the binding of 125I-porcine von Willebrand factor to human platelets was studied. Previously, we had shown that 125I-porcine von Willebrand factor binds to human platelets in the absence of ristocetin. The present work demonstrates that binding is stimulated by ristocetin and this stimulation is maximal at a ristocetin concentration of 2 mg/ml. At a ristocetin concentration of 0.5 mg/ml, Scatchard analysis indicates a binding constant of 5.18 × 10-9M and the presence of 105,000 binding sites. This compares with our previous finding, in the absence of ristocetin, of a binding constant of 2.92 × 10-7M and 4760 binding sites. These binding data assume the porcine von Willebrand factor to be a tetramer with a molecular weight of 9 × 105. This study indicates that ristocetin causes tighter binding and increases the number of binding sites on human platelets for porcine von Willebrand factor. Unlabelled porcine von Willebrand factor competitively inhibits the specific binding of the labelled protein and gives a binding constant of 0.17 × 10-9M. Similar results were obtained using human von Willebrand factor.


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