Disturbed Red Blood Cell Structure and Function: An Exploration of the Role of Red Blood Cells in Neurodegeneration.

The structure of red blood cells is affected by many inborn and acquired factors, but in most cases this does not seem to affect their function or survival in physiological conditions. Often, functional deficits become apparent only when they are subjected to biochemical or mechanical stress , or to pathological conditions . Our data on the misshapen red blood cells of patients with neuroacanthocytosis illustrate this general mechanism: an abnormal morphology is associated with an increase in the susceptibility of red blood cells to osmotic and mechanical stress, and alters their rheological properties.

Red Blood Cell Homeostasis: Mechanisms and Effects of Microvesicle Generation in Health and Disease.

Red blood cells (RBCs) generate microvesicles to remove damaged cell constituents such as oxidized hemoglobin and damaged membrane constituents, and thereby prolong their lifespan. Damage to hemoglobin, in combination with altered phosphorylation of membrane proteins such as band 3, lead to a weakening of the binding between the lipid bilayer and the cytoskeleton, and thereby to membrane budding and microparticle shedding. Microvesicle generation is disturbed in patients with RBC-centered diseases, such as sickle cell disease, glucose 6-phosphate dehydrogenase deficiency, spherocytosis or malaria.

Acetylcholinesterase provides new insights into red blood cell ageing in vivo and in vitro.

Background: During its 120 days sojourn in the circulation, the red blood cell (RBC) remodels its membrane. Acetylcholinesterase (AChE) is a glycosylphosphatidylinositol (GPI)-linked enzyme that may serve as a marker for membrane processes occurring this ageing-associated remodelling process.

Materials And Methods: Expression and enzymatic activity of AChE were determined on RBCs of various ages, as obtained by separation based on volume and density (ageing in vivo), and on RBCs of various times of storage in blood bank conditions (ageing in vitro), as well as on RBC-derived vesicles.

The Proteome of the Red Blood Cell: An Auspicious Source of New Insights into Membrane-Centered Regulation of Homeostasis.

During the past decade, the hand-in-hand development of biotechnology and bioinformatics has enabled a view of the function of the red blood cell that surpasses the supply of oxygen and removal of carbon dioxide. Comparative proteomic inventories have yielded new clues to the processes that regulate membrane-cytoskeleton interactions in health and disease, and to the ways by which red blood cells communicate with their environment. In addition, proteomic data have revealed the possibility that many, hitherto unsuspected, metabolic processes are active in the red blood cell cytoplasm.

Inflammation-associated changes in lipid composition and the organization of the erythrocyte membrane.

Background: Reduced erythrocyte survival and deformability may contribute to the so-called anemia of inflammation observed in septic patients. Erythrocyte structure and function are affected by both the membrane lipid composition and the organization. We therefore aimed to determine whether these parameters are affected during systemic inflammation.

The involvement of erythrocyte metabolism in organismal homeostasis in health and disease.

Historically, study of erythrocyte homeostasis has focussed on the survival of erythrocytes in the blood bank and, especially in pathological circumstances, on the mechanisms leading to accelerated aging and removal from the circulation. Recent proteomic and metabolomic data suggest that erythrocyte metabolism involves more than ATP production and transport of oxygen and carbondioxide; is subject to regulation; and is likely to reflect organismal metabolism. Also, it has become clear that systemic diseases affect erythrocyte homeostasis.

Platelet microparticles inhibit IL-17 production by regulatory T cells through P-selectin.

Self-tolerance and immune homeostasis are orchestrated by FOXP3(+)regulatory T cells (Tregs). Recent data have revealed that upon stimulation, Tregs may exhibit plasticity toward a proinflammatory phenotype, producing interleukin 17 (IL-17) and/or interferon γ (IFN-γ). Such deregulation of Tregs may contribute to the perpetuation of inflammatory processes, including graft-versus-host disease.

Neuroacanthocytosis: Observations, Theories and Perspectives on the Origin and Significance of Acanthocytes.

The presence of acanthocytes in the blood is characteristic of patients suffering from neuroacanthocytosis (NA). Recent studies have described abnormal phosphorylation of the proteins involved in connecting the membrane and cytoskeleton in patient-derived erythrocytes. The involvement of lipids in the underlying signaling pathways and recent reports on in vitro disease-associated lipid alterations support renewed research into lipid composition, signal transduction, and metabolism in patient erythrocytes.

Rapid transfer of overexpressed integral membrane protein from the host membrane into soluble lipid nanodiscs without previous purification.

Structural and functional characterization of integral membrane proteins in a bilayer environment is strongly hampered by the requirement of detergents for solubilization and subsequent purification, as detergents commonly affect their structure and/or activity. Here, we describe a rapid procedure with minimal exposure to detergent to directly assemble an overexpressed integral membrane protein into soluble lipid nanodiscs prior to purification. This is exemplified with recombinant his-tagged rhodopsin, which is rapidly extracted from its host membrane and directly assembled into membrane scaffold protein (MSP) nanodiscs.

Alterations in red blood cell deformability during storage: a microfluidic approach.

Red blood cells (RBCs) undergo extensive deformation when travelling through the microcapillaries. Deformability, the combined result of properties of the membrane-cytoskeleton complex, the surface area-to-volume ratio, and the hemoglobin content, is a critical determinant of capillary blood flow. During blood bank storage and in many pathophysiological conditions, RBC morphology changes, which has been suggested to be associated with decreased deformability and removal of RBC.

Abnormal red cell features associated with hereditary neurodegenerative disorders: the neuroacanthocytosis syndromes.

Purpose Of Review: This review discusses the mechanisms involved in the generation of thorny red blood cells (RBCs), known as acanthocytes, in patients with neuroacanthocytosis, a heterogenous group of neurodegenerative hereditary disorders that include chorea-acanthocytosis (ChAc) and McLeod syndrome (MLS).

Recent Findings: Although molecular defects associated with neuroacanthocytosis have been identified recently, their pathophysiology and the related RBC abnormalities are largely unknown. Studies in ChAc RBCs have shown an altered association between the cytoskeleton and the integral membrane protein compartment in the absence of major changes in RBC membrane composition.

Survival of red blood cells after transfusion: processes and consequences.

THE CURRENTLY AVAILABLE DATA SUGGEST THAT EFFORTS TOWARD IMPROVING THE QUALITY OF RED BLOOD CELL (RBC) BLOOD BANK PRODUCTS SHOULD CONCENTRATE ON: (1) preventing the removal of a considerable fraction of the transfused RBCs that takes place within the first hours after transfusion; (2) minimizing the interaction of the transfused RBCs with the patient's immune system. These issues are important in reducing the number and extent of the damaging side effects of transfusions, such as generation of alloantibodies and autoantibodies and iron accumulation, especially in transfusion-dependent patients. Thus, it becomes important for blood bank research not only to assess the classical RBC parameters for quality control during storage, but even more so to identify the parameters that predict RBC survival, function and behavior in the patient after transfusion.

Phosphatidylserine exposure on stored red blood cells as a parameter for donor-dependent variation in product quality.

Background: Exposure of phosphatidylserine on the outside of red blood cells contributes to recognition and removal of old and damaged cells. The fraction of phosphatidylserine-exposing red blood cells varies between donors, and increases in red blood cell concentrates during storage. The susceptibility of red blood cells to stress-induced phosphatidylserine exposure increases with storage.

Gateway to understanding microparticles: standardized isolation and identification of plasma membrane-derived vesicles.

Microparticles (MPs) are small plasma membrane-derived vesicles that can expose molecules originating from their parental cells. As vectors of biological information they are likely to play an active role in both homeostasis and pathogenesis, making them promising biomarkers and nanomedicine tools. Therefore, there is an urgent need for standardization of MP isolation and analysis protocols to propel our understanding of MP biology to the next level.

Storage-induced changes in erythrocyte membrane proteins promote recognition by autoantibodies.

Physiological erythrocyte removal is associated with a selective increase in expression of neoantigens on erythrocytes and their vesicles, and subsequent autologous antibody binding and phagocytosis. Chronic erythrocyte transfusion often leads to immunization and the formation of alloantibodies and autoantibodies. We investigated whether erythrocyte storage leads to the increased expression of non-physiological antigens.

The proteome of erythrocyte-derived microparticles from plasma: new clues for erythrocyte aging and vesiculation.

Vesicle formation is an integral part of the physiological erythrocyte aging process. Recent biophysical and immunochemical data have suggested that vesicles originate by the extrusion of membrane patches that, during aging, have become damaged and simultaneously enriched in removal signals. Thereby, vesiculation may serve to postpone the untimely removal of functional cells.

Erythrocyte membrane changes of chorea-acanthocytosis are the result of altered Lyn kinase activity.

Acanthocytic RBCs are a peculiar diagnostic feature of chorea-acanthocytosis (ChAc), a rare autosomal recessive neurodegenerative disorder. Although recent years have witnessed some progress in the molecular characterization of ChAc, the mechanism(s) responsible for generation of acanthocytes in ChAc is largely unknown. As the membrane protein composition of ChAc RBCs is similar to that of normal RBCs, we evaluated the tyrosine (Tyr)-phosphorylation profile of RBCs using comparative proteomics.

Susceptibility to hyperosmotic stress-induced phosphatidylserine exposure increases during red blood cell storage.

Background: During storage of red blood cell (RBCs) before transfusion, RBCs undergo a series of structural and functional changes that include the exposure of phosphatidylserine (PS), a potent removal signal. It was postulated that, during blood bank storage, the susceptibility to stress-induced PS exposure increases, thereby rendering a considerable fraction of the RBCs susceptible to rapid removal after transfusion.

Study Design And Methods: RBCs were processed and stored following standard Dutch blood bank procedures.

Uniform stable-isotope labeling in mammalian cells: formulation of a cost-effective culture medium.

Uniform stable-isotope labeling of mammalian cells is achieved via a novel formulation of a serum-free cell culture medium that is based on stable-isotope-labeled autolysates and lipid extracts of various microbiological origin. Yeast autolysates allow complete replacement of individual amino acids and organic acids in a chemically defined medium (DMEM/F12), enabling a cost-effective formulation of a stable-isotope-labeled culture medium for mammalian cells. In addition, biomass-derived hydrolysates, autolysates, and lipid extracts of various classes of algae were explored as cell culture components, both separately and in combination with yeast autolysates.

P2X7 receptor activation induces cell death and microparticle release in murine erythroleukemia cells.

Extracellular ATP induces cation fluxes in and impairs the growth of murine erythroleukemia (MEL) cells in a manner characteristic of the purinergic P2X7 receptor, however the presence of P2X7 in these cells is unknown. This study investigated whether MEL cells express functional P2X7. RT-PCR, immunoblotting and immunofluorescence staining demonstrated the presence of P2X7 in MEL cells.

A single assay for multiple storage-sensitive red blood cell characteristics by means of infrared spectroscopy.

Background: To maintain a high quality of red blood cells (RBCs), RBC characteristics must be followed during storage under blood bank conditions. By means of infrared (IR) spectroscopy, several characteristics can be measured simultaneously.

Study Design And Methods: IR spectra were acquired for samples from RBCs that were collected and stored according to Dutch blood bank procedures for a period of up to 50 days.

Survival of red blood cells after transfusion: a comparison between red cells concentrates of different storage periods.

Background: The use of fresh red blood cells (RBCs) is recommended for critically ill patients and patients undergoing surgery, although there is no conclusive evidence that this is beneficial. In this follow-up study, the short-term and the long-term recovery of irradiated, leukoreduced RBCs transfused after either a short storage (SS) or a long storage (LS) period were compared. By consecutive transfusion of RBCs with a SS and LS period, a direct comparison of their survival within the same patient was possible.