scholarly journals Canine erythrocytes express the P2X7receptor: greatly increased function compared with human erythrocytes

2007 ◽  
Vol 293 (5) ◽  
pp. R2090-R2098 ◽  
Author(s):  
Ronald Sluyter ◽  
Anne N. Shemon ◽  
William E. Hughes ◽  
Ryan O. Stevenson ◽  
Jennifer G. Georgiou ◽  
...  
Keyword(s):  
Extracellular Atp ◽  
Human Erythrocytes ◽  
Channel Pore ◽  
Flow Cytometric ◽  
Phosphatidylserine Exposure ◽  
Overnight Incubation ◽  
Cation Permeability ◽  
Dose Dependent Fashion ◽  
Permeability Increase ◽  
And Function

Over three decades ago, Parker and Snow ( Am J Physiol 223: 888–893, 1972) demonstrated that canine erythrocytes undergo an increase in cation permeability when incubated with extracellular ATP. In this study we examined the expression and function of the channel/pore-forming P2X7receptor on canine erythrocytes. P2X7receptors were detected on canine erythrocytes by immunocytochemistry and immunoblotting. Extracellular ATP induced86Rb+(K+) efflux from canine erythrocytes that was 20 times greater than that from human erythrocytes. The P2X7agonist 2′(3′)- O-(4-benzoylbenzoyl)adenosine 5′-trisphosphate (BzATP) was more potent than ATP, and both stimulated86Rb+efflux from erythrocytes in a dose-dependent fashion with EC50values of ∼7 and ∼309 μM, respectively. 2-Methylthioadenosine 5′-triphosphate and adenosine 5′- O-(3-thiotriphosphate) induced a smaller86Rb+efflux from erythrocytes, whereas ADP, AMP, UTP, or adenosine had no effect. ATP-induced86Rb+efflux from erythrocytes was inhibited by oxidized ATP, KN-62, and Brilliant blue G, known P2X7antagonists. ATP also induced uptake of choline+into canine erythrocytes that was 60 times greater than that into human erythrocytes. Overnight incubation of canine erythrocytes with ATP and BzATP induced phosphatidylserine exposure in >80% of cells and caused up to 20% hemolysis. In contrast, <30% of human erythrocytes showed phosphatidylserine exposure after overnight incubation with ATP and BzATP, and hemolysis was negligible. Flow cytometric measurements of ATP-induced ethidium+uptake showed that P2X7function was three times lower in canine monocytes than in human monocytes. These data show that the massive cation permeability increase induced by extracellular ATP in canine erythrocytes results from activation and opening of the P2X7receptor channel/pore.

scholarly journals Role of Calcium in Phosphatidylserine Externalisation in Red Blood Cells from Sickle Cell Patients

Anemia ◽  
2011 ◽  
Vol 2011 ◽  
pp. 1-8 ◽  
Author(s):  
Erwin Weiss ◽  
David Charles Rees ◽  
John Stanley Gibson
Keyword(s):  
Red Blood Cells ◽  
Sickle Cell ◽  
Blood Cells ◽  
Phosphatidylserine Exposure ◽  
Channel Inhibition ◽  
Cation Conductance ◽  
Gardos Channel ◽  
Cation Permeability

Phosphatidylserine exposure occurs in red blood cells (RBCs) from sickle cell disease (SCD) patients and is increased by deoxygenation. The mechanisms responsible remain unclear. RBCs from SCD patients also have elevated cation permeability, and, in particular, a deoxygenation-induced cation conductance which mediates entry, providing an obvious link with phosphatidylserine exposure. The role of was investigated using FITC-labelled annexin. Results confirmed high phosphatidylserine exposure in RBCs from SCD patients increasing upon deoxygenation. When deoxygenated, phosphatidylserine exposure was further elevated as extracellular [] was increased. This effect was inhibited by dipyridamole, intracellular chelation, and Gardos channel inhibition. Phosphatidylserine exposure was reduced in high saline. levels required to elicit phosphatidylserine exposure were in the low micromolar range. Findings are consistent with entry through the deoxygenation-induced pathway (), activating the Gardos channel. [] required for phosphatidylserine scrambling are in the range achievablein vivo.

scholarly journals A carbohydrate-deficient membrane glycoprotein in human erythrocytes of phenotype S-s-

1977 ◽  
Vol 165 (1) ◽  
pp. 157-161 ◽  
Author(s):  
M J A Tanner ◽  
D J Anstee ◽  
P A Judson
Keyword(s):  
Blood Group ◽  
Arachis Hypogaea ◽  
Human Erythrocyte ◽  
Structure And Function ◽  
Human Erythrocytes ◽  
Erythrocyte Membranes ◽  
Membrane Glycoprotein ◽  
Blood Group Antigens ◽  
And Function ◽  
Normal Erythrocyte

1. We investigated the membranes of human erythrocytes which completely lack the blood-group antigens S and s (denoted as S-s-) as part of a study of the structure and function of the surface glycoproteins of the human erythrocyte. 2. The S-s-erythrocyte-membrane glycoprotein PAS-3 band was much less intensely stained in comparison with that of the glycoprotein from normal erythrocyte membranes. The S-s-membrane glycoprotein PAS-4 band also showed decreased staining. 3. Examination with the lectins from Maclura aurantiaca (Osage orange) and Arachis hypogaea (groundnut) showed that the PAS-3 glycoprotein of S-s-erythrocyte membranes lacked the receptors for these lectins that are present on glycoprotein PAS-3 from normal erythrocytes. 4. Radioiodination with lactoperoxidase showed the presence of the polypeptide of glycoprotein PAS-3 in S-s-cells, although it was more weakly labelled than the protein in the normal erythrocyte. 5. Our results show that the PAS-3 glycoprotein of S-s-erythrocytes is deficient in some of the carbohydrates present in the protein from normal erythrocytes. Glycoprotein PAS-4 of normal erythrocytes is shown to be a complex containing both glycoproteins PAS-1 and PAS-3.

scholarly journals Association between morphologic distortion of sickle cells and deoxygenation-induced cation permeability increase

Blood ◽  
1986 ◽  
Vol 68 (2) ◽  
pp. 450-454 ◽  
Author(s):  
N Mohandas ◽  
ME Rossi ◽  
MR Clark
Keyword(s):  
Mechanical Stress ◽  
Hemoglobin Concentration ◽  
Minimal Effect ◽  
Concomitant Increase ◽  
Sickle Cells ◽  
Cation Permeability ◽  
Extensive Growth ◽  
Permeability Increase ◽  
K Permeability ◽  
Mean Cell Hemoglobin

We hypothesized that the deoxygenation-induced increase in cation permeability of sickle cells was related to mechanical distention of the membrane by growing HbS polymer within the cell. To test this hypothesis, we determined the effect of deoxygenation on cation fluxes in sickle cells under conditions that restricted or permitted extensive growth of polymer, producing different degrees of membrane distention. Manipulation of suspending medium osmolality for density-isolated high and low mean cell hemoglobin concentration (MCHC) cells was used to regulate the extensional growth of polymer bundles and hence membrane distortion. For initially low MCHC cells, the deoxygenation-induced increase in both Na and K fluxes was markedly suppressed when the MCHC was increased by increasing the osmolality. This suppression corresponded to the inhibition of extensive morphologic cellular distortion. For initially high MCHC, ISC-rich cells, deoxygenation had minimal effect on K permeability. However, reduction of MCHC by a decrease in osmolality produced a concomitant increase in cation permeability and cellular distortion. These observations support the idea that the sickling-associated increase in membrane permeability is related to mechanical stress imposed on the membrane by bundles of HbS polymer.

scholarly journals Effect of mechanical deformation on structure and function of polymorphonuclear leukocytes

1997 ◽  
Vol 82 (5) ◽  
pp. 1397-1405 ◽  
Author(s):  
Yuko Kitagawa ◽  
Stephan F. Van Eeden ◽  
Darlene M. Redenbach ◽  
Maleki Daya ◽  
Blair A. M. Walker ◽  
...  
Keyword(s):  
Polymorphonuclear Leukocytes ◽  
Polarization Characteristic ◽  
Mechanical Deformation ◽  
Structure And Function ◽  
Functional Changes ◽  
Flow Cytometric ◽  
Pulmonary Capillaries ◽  
Pulmonary Capillary ◽  
Capillary Bed ◽  
And Function

Kitagawa, Yuko, Stephan F. Van Eeden, Darlene M. Redenbach, Maleki Daya, Blair A. M. Walker, Maria E. Klut, Barry R. Wiggs, and James C. Hogg. Effect of mechanical deformation on structure and function of polymorphonuclear leukocytes. J. Appl. Physiol. 82(5): 1397–1405, 1997.—The present studies were designed to test the hypothesis that mechanical deformation of polymorphonuclear leukocytes (PMN) leads to functional changes that might influence their transit in the pulmonary capillaries. Human leukocytes were passed through 5- or 3-μm-pore polycarbonate filters under controlled conditions. Morphometric analysis showed that the majority of PMN were deformed and that this deformation persisted longer after filtration through 3-μm filters than through 5-μm filters ( P < 0.05) but did not result in the cytoskeletal polarization characteristic of migrating cells. Flow cytometric studies of the filtered PMN showed that there was a transient increase in the cytosolic free Ca2+ concentration after both 3- and 5-μm filtration ( P< 0.01) with an increase in F-actin content after 3-μm filtration ( P < 0.05). AlthoughL-selectin expression on PMN was not changed by either 5- or 3-μm filtration, CD18 and CD11b were increased by 3-μm filtration ( P < 0.05). Priming of the PMN with N-formyl-methionyl-leucyl-phenylalanine (0.5 nM) before filtration resulted in an increase of CD11b by both 5 ( P < 0.05)- and 3-μm ( P < 0.01) filtration. Neither 5- nor 3-μm filtration induced hydrogen peroxide production. We conclude that mechanical deformation of PMN, similar to what occurs in the pulmonary microvessels, induces both structural and functional changes in the cells, which might influence their passage through the pulmonary capillary bed.

Reduced numbers of peripheral blood CD27+ IgD– memory B cells in patients with aggressive periodontitis

2015 ◽  
Vol 39 (3) ◽  
Author(s):  
Holger Jentsch ◽  
Regina Purschwitz ◽  
Catalina Suzana Stingu ◽  
Jana Schmidt ◽  
Ulrich Sack
Keyword(s):  
B Cells ◽  
Peripheral Blood ◽  
Substantial Reduction ◽  
Flow Cytometric Analysis ◽  
Aggressive Periodontitis ◽  
Memory B Cells ◽  
Multifactorial Disease ◽  
Periodontal Condition ◽  
Flow Cytometric ◽  
And Function

AbstractAggressive periodontitis (AgP) is a multifactorial disease with unknown association to the development and function of peripheral lymphocytes. The aim of this study was to elucidate a connection between the periodontal condition in 10 patients with AgP and their potential state of immunodeficiency. Based on full periodontal examination and radiographs, 10 females (ages 29.8±8.62 years) with established diagnosis of aggressive periodontitis were included in this study. Flow cytometric analysis revealed substantial reduction of switched memory B cells (IgM

Flow cytometric measurement of mitochondrial mass and function: A novel method for assessing chemoresistance

1998 ◽  
Vol 5 (3) ◽  
pp. 287-295 ◽  
Author(s):  
Mariangela Mancini ◽  
Monireh Sedghinasab ◽  
Katya Knowlton ◽  
Amy Tam ◽  
David Hockenberg ◽  
...  
Keyword(s):  
Mitochondrial Mass ◽  
Flow Cytometric ◽  
Flow Cytometric Measurement ◽  
Novel Method ◽  
And Function

scholarly journals Association between morphologic distortion of sickle cells and deoxygenation-induced cation permeability increase

Blood ◽  
1986 ◽  
Vol 68 (2) ◽  
pp. 450-454 ◽  
Author(s):  
N Mohandas ◽  
ME Rossi ◽  
MR Clark
Keyword(s):  
Mechanical Stress ◽  
Hemoglobin Concentration ◽  
Minimal Effect ◽  
Concomitant Increase ◽  
Sickle Cells ◽  
Cation Permeability ◽  
Extensive Growth ◽  
Permeability Increase ◽  
K Permeability ◽  
Mean Cell Hemoglobin

Abstract We hypothesized that the deoxygenation-induced increase in cation permeability of sickle cells was related to mechanical distention of the membrane by growing HbS polymer within the cell. To test this hypothesis, we determined the effect of deoxygenation on cation fluxes in sickle cells under conditions that restricted or permitted extensive growth of polymer, producing different degrees of membrane distention. Manipulation of suspending medium osmolality for density-isolated high and low mean cell hemoglobin concentration (MCHC) cells was used to regulate the extensional growth of polymer bundles and hence membrane distortion. For initially low MCHC cells, the deoxygenation-induced increase in both Na and K fluxes was markedly suppressed when the MCHC was increased by increasing the osmolality. This suppression corresponded to the inhibition of extensive morphologic cellular distortion. For initially high MCHC, ISC-rich cells, deoxygenation had minimal effect on K permeability. However, reduction of MCHC by a decrease in osmolality produced a concomitant increase in cation permeability and cellular distortion. These observations support the idea that the sickling-associated increase in membrane permeability is related to mechanical stress imposed on the membrane by bundles of HbS polymer.

scholarly journals Extracellular adenosine triphosphate increases cation permeability of chronic lymphocytic leukemic lymphocytes

Blood ◽  
1989 ◽  
Vol 73 (5) ◽  
pp. 1316-1323 ◽  
Author(s):  
JS Wiley ◽  
GR Dubyak
Keyword(s):  
Adenosine Triphosphate ◽  
Fold Increase ◽  
Normal Subjects ◽  
Peripheral Blood Lymphocytes ◽  
Extracellular Atp ◽  
Total Cell ◽  
Lymphocytic Leukemia ◽  
Maximal Response ◽  
Extracellular Adenosine ◽  
Cation Permeability

Abstract Extracellular adenosine triphosphate (ATP) is known to reversibly increase the cation permeability of a variety of freshly isolated and cultured cell types. In this study the effects of extracellular ATP were studied using peripheral blood lymphocytes (PBL) isolated from both normal subjects and from patients with chronic lymphocytic leukemia (CLL). Changes in the permeability to Na+, Rb+, and Li+ ions were measured using conventional isotope and flame photometry techniques. In addition, changes in cytosolic (Ca2+) were fluorimetrically monitored to assess possible changes in net Ca2+ influx. ATP produced a 12-fold increase in 22Na+ influx into CLL cells but only a 3.5-fold increase in this flux in PBL cells. A maximal response was produced by 0.1 mmol/L ATP in the absence of Mg2+, while a twofold molar excess of Mg2+ over ATP abolished the response. ATP had no effect on the passive (ouabain-insensitive) 86Rb+ influx into PBL cells but stimulated this flux by fivefold in the CLL cells. Li+ influx into CLL cells was also stimulated threefold by ATP. Under these same conditions ATP also produced a net increase in total cell Na and a decrease in total cell K in the CLL cells. Exclusion of two normally impermeable dyes, trypan blue and ethidium bromide, was not altered in the ATP-treated CLL cells. Finally, extracellular ATP (3 mmol/L) produced no significant change in the cytosolic (Ca2+) of normal, monocyte-depleted populations of PBL. Conversely, this same concentration of ATP produced a very rapid (complete within 30 seconds) and a significant (an average threefold peak change) increase in the cytosolic (Ca2+) of cell preparations derived from five out of nine CLL patients. In these latter CLL cells, the ATP-induced elevation in cytosolic (Ca2+) appeared to be due to a net increase in Ca2+ influx, since no elevations were observed when the extracellular (Ca2+) was reduced to less than 0.1 mmol/L. These actions of ATP were specific in that equimolar concentrations of other nucleotides were without effect. These data indicate that treatment of CLL lymphocytes with extracellular ATP4 produces large increases in cation permeability. In contrast, there is less or no ATP-induced permeabilization of normal PBL.

scholarly journals Evidence that the uptake of tri-iodo-l-thyronine by human erythrocytes is carrier-mediated but not energy-dependent

1982 ◽  
Vol 208 (1) ◽  
pp. 27-34 ◽  
Author(s):  
Roelof Docter ◽  
Eric P. Krenning ◽  
Greetje Bos ◽  
Durk F. Fekkes ◽  
George Hennemann
Keyword(s):  
Contrast Agents ◽  
Rat Hepatocytes ◽  
Human Erythrocytes ◽  
Uptake System ◽  
Erythrocyte Ghosts ◽  
Intact Cells ◽  
X Ray ◽  
Dose Dependent Fashion ◽  
Uptake Studies ◽  
Energy Dependent

We investigated 3,3′,5-tri-iodo-l-thyronine transport by human erythrocytes and by ‘ghosts’ prepared from these cells. Uptake of tri-iodothyronine by erythrocytes at 37°C was time-dependent with a maximum reached after 60min. Tracer analysis after incubation for 1min revealed only one saturable binding site, with Km 128±19nm (mean±s.e.m.; n=7) and Vmax. 4.6±0.7pmol of tri-iodothyronine/min per 6×107 cells. After 10min incubation Km 100±16nm (n=10) was found with Vmax. 7.7±1.2pmol of tri-iodothyronine/10min per 6×107 cells. At 0°C the uptake system is still active, with Km 132±26nm and Vmax. 1.8±0.3pmol of tri-iodothyronine/10min per 6×107 cells. The Vmax. with intact cells is 5-fold greater than the Vmax. with membranes derived from the same amount of cells when uptake studies are performed in media with similar free tri-iodothyronine concentrations. This indicates that at least 80% of tri-iodothyronine taken up by the intact erythrocytes enters the cell. This saturable uptake system can be inhibited by X-ray-contrast agents in a dose-dependent fashion. (±)-Propranolol, but not atenolol, has the same effect, indicating that the membrane-stabilizing properties of (±)-propranolol are involved. Furthermore, there is no inhibition by ouabain or vanadate, which indicates that tri-iodothyronine uptake is not dependent on the activity of Na++K+-dependent adenosine triphosphatase. We have prepared erythrocyte ‘ghosts‘, resealed after 2.5min with 0mm-, 2mm- or 4mm-ATP inside. Inclusion of ATP and integrity of the membrane of the erythrocyte ‘ghosts’ were verified on the basis of an ATP-concentration-dependent functioning of the Ca2+ pump. No difference was found in the uptake of tri-iodothyronine by erythrocyte ‘ghosts’ with or without ATP included, indicating that uptake of tri-iodothyronine is not ATP-dependent. The following conclusions are drawn. (1) Tri-iodothyronine enters human erythrocytes. (2) There is only one saturable uptake system present for tri-iodothyronine, which is neither energy (i.e. ATP)-dependent nor influenced by the absence of an Na+ gradient across the plasma membrane. This mode of uptake of tri-iodothyronine by human erythrocytes is in sharp contrast with that of rat hepatocytes, which uptake system is energy-dependent and ouabain-sensitive [Krenning, Docter, Bernard, Visser & Hennemann (1978) FEBS Lett.91, 113–116; Krenning, Docter, Bernard, Visser & Hennemann (1980) FEBS Lett.119, 279–282]. (3) X-ray-contrast agents inhibit tri-iodothyronine uptake by erythrocytes in a similar fashion to that by which they inhibit the uptake of tri-iodothyronine by rat hepatocytes [Krenning, Docter, Bernard, Visser & Hennemann (1982) FEBS Lett.140, 229–233].

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