scholarly journals Oxidation of intracellular glutathione after exposure of human red blood cells to hypochlorous acid

1995 ◽  
Vol 307 (1) ◽  
pp. 57-62 ◽  
Author(s):  
M C M Vissers ◽  
C C Winterbourn
Keyword(s):  
Red Blood Cells ◽  
Blood Cells ◽  
Hypochlorous Acid ◽  
Low Doses ◽  
Red Cell Membrane ◽  
Human Red Blood Cells ◽  
Cell Components ◽  
Slow Infusion ◽  
Higher Doses ◽  
Selective Process

Exposure of human red blood cells to low doses of hypochlorous acid (HOCl) resulted in the loss of intracellular GSH. Oxidation occurred less than 2 min after the addition of HOCl, and required approx. 2.5 mol of HOCl per mol of GSH lost. Loss of GSH preceded oxidation of membrane thiols, the formation of chloramines and haemoglobin oxidation. The susceptibility of intracellular GSH to oxidation by HOCl was two-thirds that of GSH in cell lysates. These results indicate that HOCl can penetrate the red cell membrane, which provides little barrier protection for cytoplasmic components, and that GSH oxidation by HOCl may be a highly selective process. Virtually all of the GSH lost was converted into GSSG. If glucose was added to the medium, most of the GSH oxidized by low doses of HOCl was rapidly regenerated. At higher doses, recovery was less efficient. However, when HOCl was added as a slow infusion rather than in a single bolus, there was increased recovery at higher doses. This indicates that in metabolically active cells regeneration is rapid and GSH may protect cell components from damage by HOCl. HOCl-induced lysis was only slightly delayed by adding glucose to the medium, indicating that lytic injury is not ameliorated by GSH.

scholarly journals Hemagglutination by B. fragilis is mediated by capsular polysaccharides and is influenced by host ABO blood type

2020 ◽  
Author(s):  
Kathleen L. Arnolds ◽  
Nancy Moreno-Huizar ◽  
Maggie A. Stanislawski ◽  
Brent Palmer ◽  
Catherine Lozupone
Keyword(s):  
Red Blood Cells ◽  
Blood Cells ◽  
The Body ◽  
Blood Type ◽  
Capsular Polysaccharides ◽  
Host Interactions ◽  
Host Immune Responses ◽  
Human Red Blood Cells ◽  
Cell Components ◽  
Abo Blood Type

Bacterial hemagglutination of red blood cells (RBCs) is mediated by interactions between bacterial cell components and RBC envelope glycans that vary across individuals by ABO blood type. ABO glycans are also expressed on intestinal epithelial cells and in most individuals secreted into the intestinal mucosa, indicating that hemagglutination by bacteria may be informative about bacteria-host interactions in the intestine. Bacteroides fragilis, a prominent member of the human gut microbiota, can hemagglutinate RBCs by an unknown mechanism. Using a novel technology for quantifying bacterial hemagglutination, genetic knockout strains of B. fragilis and blocking antiserums, we demonstrate that the capsular polysaccharides of B. fragilis, polysaccharide B (PSB), and PSC are both strong hemagglutinins. Furthermore, the capacity of B. fragilis to hemagglutinate was much stronger in individuals with Type O blood compared to Types A and B, an adaptation that could impact the capacity of B. fragilis to colonize and thrive in the host.Importance StatementThis study found that the human pathobiont, B. fragilis, hemagglutinates human red blood cells using specific capsular polysaccharides (PSB and PSC) which are known to be important for interacting with and influencing host immune responses. Because the factors found on red blood cells are also abundantly expressed on other tissues and in the mucous, the ability to hemagglutinate sheds light on interactions between bacteria and host throughout the body. Intriguingly, the strength of hemagglutination varied based on the ABO blood type of the host, a finding which could have implications for understanding if an individual’s blood type may influence interactions with B. fragilis and its potential as a pathogen versus a commensal.

scholarly journals The relation between dicarbocyanine dye fluorescence and the membrane potential of human red blood cells set at varying Donnan equilibria.

1979 ◽  
Vol 74 (2) ◽  
pp. 187-212 ◽  
Author(s):  
J C Freedman ◽  
J F Hoffman
Keyword(s):  
Membrane Potential ◽  
Fluorescence Quenching ◽  
Red Blood Cells ◽  
Blood Cells ◽  
Red Cell Membrane ◽  
Human Red Blood Cells ◽  
Fluorescence Measurements ◽  
Constant E ◽  
Diffusion Potentials ◽  
Dye Fluorescence

The fluorescence, F, of two dicarbocyanine dyes, diS-C3(5) and diI-C3(5), depends both on the membrane potential, E, and on the intracellular pH, pHc, or human red blood cells. Compositions of isotonic media have been devised in which the equilibrium Donnan potential, E, varies at constant pHc and in which pHc varies at constant E. Dye fluorescence measurements in these suspensions yield calibrations of +1.7 % delta F/mV for diS-C3(5) and +0.6 % delta F/mV for diI-C3 (5). While pHo does not affect F of either dye, changes in pHc of 0.1 unit at constant E cause changes of F equivalent to those induced by 2--3mV. Based on these results, a method is given for estimating changes in E from dye fluorescence in experiments in which E and pHc co-vary. The relation of F to E also depends in a complex way on the type and concentration of cells and dye, and the wavelengths employed. The equilibrium calibration of dye fluorescence, when applied to diffusion potentials induced by 1 microM valinomycin, yields a value for the permeability ratio, PK.VAL/PCl, of 20 +/- 5, in agreement with previous estimates by other methods. The calibration of F is identical both for diffusion potentials and for equilibrium potentials, implying that diC-C3(5) responds to changes in voltage independently of ionic fluxes across the red cell membrane. Changes in the absorption spectra of dye in the presence of red cells in response to changes in E show that formation of nonfluorescent dimers contributes to fluorescence quenching of diS-C3(5). In contrast, only a hydrophobic interaction of dye monomers need be considered for diI-C3(5), indicating the occurrence of a simpler mechanism of fluorescence quenching.

scholarly journals Human red blood cells express the RNA sensor TLR7 and bind viral RNA

2022 ◽  
Author(s):  
LK Metthew Lam ◽  
Rebecca L. Clements ◽  
Kaitlyn A. Eckart ◽  
Ariel R. Weisman ◽  
Andy E. Vaughan ◽  
...  
Keyword(s):  
Nucleic Acid ◽  
Red Blood Cells ◽  
Blood Cells ◽  
Rna Binding ◽  
Protein Band ◽  
Immune Functions ◽  
Red Cell Membrane ◽  
Human Red Blood Cells ◽  
Rbc Membrane ◽  
Human Rbcs

Red blood cells (RBCs) express the nucleic acid-sensing toll-like receptor 9 (TLR9) and bind CpG-containing DNA. However, whether human RBCs express other nucleic acid-sensing TLRs and bind RNA is unknown. Here we show that human RBCs express the RNA sensor, TLR7. TLR7 is present on the red cell membrane and associates with the RBC membrane protein Band 3. RBCs bind synthetic single-stranded RNA and RNA from pathogenic single-stranded RNA viruses. RNA acquisition by RBCs is attenuated by recombinant TLR7 and inhibitory oligonucleotides. Thus, RBCs may represent a previously unrecognized reservoir for RNA, although how RNA-binding by RBCs modulates the immune response has yet to be elucidated. These findings add to the growing list of non-gas exchanging RBC immune functions.

Hypochlorous acid-induced oxidative damage of human red blood cells: effects of tert-butyl hydroperoxide and nitrite on the HOCl reaction with erythrocytes

2002 ◽  
Vol 58 (2) ◽  
pp. 127-135 ◽  
Author(s):  
Ilya B. Zavodnik ◽  
Elena A. Lapshina ◽  
Lev B. Zavodnik ◽  
Mirosław Soszyński ◽  
Grzegorz Bartosz ◽  
...  
Keyword(s):  
Oxidative Damage ◽  
Red Blood Cells ◽  
Blood Cells ◽  
Hypochlorous Acid ◽  
Butyl Hydroperoxide ◽  
Tert Butyl ◽  
Human Red Blood Cells ◽  
Tert Butyl Hydroperoxide
Sign in / Sign up

Export Citation Format

Share Document