Conformational Distortions of the Red Blood Cell Spectrin Matrix Nanostructure in Response to Temperature Changes In Vitro

Effect of the delayed wash (deglycerolisation) on the red blood cell morphology: Comparison of AFM and optical profilometry

The morphological characterisation is crucial for analysing cell states, especially for red blood cells (RBCs), which are used in transfusions. This study compared the applicability of atomic force microscopy (AFM) and confocal optical profilometry in the accurate characterisation of the RBC morphological parameters. The imaging of RBCs thawed after cryopreservation with immediate and delayed washing steps (deglycerolisation) was performed, and the morphological data obtained with AFM and optical profilometry were compared with the clinical laboratory studies. Both techniques provided close data on the morphological parameters, but optical profilometry allowed a faster and more convenient data acquisition. However, the membrane roughness analysis on discocytes and the submembrane cytoskeleton analysis on RBC ghosts was only possible with AFM due to its higher spatial resolution. Both techniques confirmed that delayed washing did not have negative effects on cells compared to immediate washing. Additional 3-day storage of both types of RBCs resulted in increased haemolysis. A decrease in the fraction of area occupied by pores in the submembrane cytoskeleton with the storage time was observed, possibly associated with the cytoskeleton deterioration. The studied conditions model the transportation of thawed RBCs in a cryoprotectant solution to medical facilities that have technical conditions to wash thawed RBCs and confirm its feasibility.

Single cell force spectroscopy of erythrocytes at physiological and febrile temperatures reveals mechano-modulatory effects of atorvastatin

RBCs are mechanically active cells and constantly deform as they circulate through vasculature. Their mechanical properties can be significantly altered by various pathophysiological conditions, and the alterations in RBC mechanics can, in turn, have functional consequences. Although numerous mechanical studies have been conducted on RBCs, surprisingly, strain-rate and temperature dependent mechanics of RBCs have not been systematically examined, and current data is primarily based on measurements at room temperature. Here, we have used state-of-the-art single-cell optical tweezers to probe atorvastatin-induced changes of RBC mechanics and its strain-rate dependency at physiologically and medically relevant temperatures. Our data indicate that RBC mechanics is strain-rate and temperature dependent, and atorvastatin treatment softens RBCs at physiological temperature, but not at febrile temperature. The observed mechanical change is a notable side effect of the drug in some therapeutic applications. However, the mechano-modulatory effects of atorvastatin on erythrocytes at physiological temperature might offer new therapeutic possibilities for diseases related to blood cell mechanics.

Topological Relationships Cytoskeleton-Membrane Nanosurface-Morphology as a Basic Mechanism of Total Disorders of RBC Structures

The state of red blood cells (RBCs) and their functional possibilities depend on the structural organization of the membranes. Cell morphology and membrane nanostructure are compositionally and functionally related to the cytoskeleton network. In this work, the influence of agents (hemin, endogenous oxidation during storage of packed RBCs, ultraviolet (UV) radiation, temperature, and potential of hydrogen (pH) changes) on the relationships between cytoskeleton destruction, membrane nanostructure, and RBC morphology was observed by atomic force microscope. It was shown that the influence of factors of a physical and biochemical nature causes structural rearrangements in RBCs at all levels of organization, forming a unified mechanism of disturbances in relationships “cytoskeleton-membrane nanosurface-cell morphology”. Filament ruptures and, consequently, large cytoskeleton pores appeared. The pores caused membrane topological defects in the form of separate grain domains. Increasing loading doses led to an increase in the number of large cytoskeleton pores and defects and their fusion at the membrane nanosurfaces. This caused the changes in RBC morphology. Our results can be used in molecular cell biology, membrane biophysics, and in fundamental and practical medicine.

Red Blood Cells' Thermodynamic Behavior in Neurodegenerative Pathologies and Aging

The main trend of current research in neurodegenerative diseases (NDDs) is directed towards the discovery of novel biomarkers for disease diagnostics and progression. The pathological features of NDDs suggest that diagnostic markers can be found in peripheral fluids and cells. Herein, we investigated the thermodynamic behavior of the peripheral red blood cells (RBCs) derived from patients diagnosed with three common NDDs—Parkinson’s disease (PD), Alzheimer’s disease (AD), and amyotrophic lateral sclerosis (ALS) and compared it with that of healthy individuals, evaluating both fresh and aged RBCs. We established that NDDs can be differentiated from the normal healthy state on the basis of the variation in the thermodynamic parameters of the unfolding of major RBCs proteins—the cytoplasmic hemoglobin (Hb) and the membrane Band 3 (B3) protein. A common feature of NDDs is the higher thermal stability of both Hb and B3 proteins along the RBCs aging, while the calorimetric enthalpy can distinguish PD from ALS and AD. Our data provide insights into the RBCs thermodynamic behavior in two complex and tightly related phenomena—neurodegenerative pathologies and aging, and it suggests that the determined thermodynamic parameters are fingerprints of the altered conformation of Hb and B3 protein and modified RBCs’ aging in the studied NDDs.

Nanoscale Changes on RBC Membrane Induced by Storage and Ionizing Radiation: A Mini-Review

The storage lesions and the irradiation of blood cellular components for medical procedures in blood banks are events that may induce nanochanges in the membrane of red blood cells (RBCs). Alterations, such as the formation of pores and vesicles, reduce flexibility and compromise the overall erythrocyte integrity. This review discusses the alterations on erythrocytic lipid membrane bilayer through their characterization by confocal scanning microscopy, Raman, scanning electron microscopy, and atomic force microscopy techniques. The interrelated experimental results may address and shed light on the correlation of biomechanical and biochemical transformations induced in the membrane and cytoskeleton of stored and gamma-irradiated RBC. To highlight the main advantages of combining these experimental techniques simultaneously or sequentially, we discuss how those outcomes observed at micro- and nanoscale cell levels are useful as biomarkers of cell aging and storage damage.

Two-step process of cytoskeletal structural damage during long-term storage of packed red blood cells

BACKGROUND

Storage of packed red blood cells (PRBC) for 42 days causes morphological, structural, and functional changes in the red cells. To assess the quality of stored PRBC, it is important to evaluate the main components of the product. The aim of this study was to evaluate the kinetics of the structural transformations in the cytoskeleton of red cells during long-term storage (up to 42 days).

MATERIALS AND METHODS

Bags of PRBC were stored with CPD/SAGM solution at +4 °C. Cytoskeletal parameters were measured on days 3, 12, 19, 21, 24, 28, 35, and 42 of storage to determine their changes. Atomic force microscopy was used to obtain images and analyse the parameters of the cytoskeletal network. As the storage time increased, a general PRBC test was performed. Membrane fixatives were not used at any stage of the preparation of the specimens for cytoskeletal imaging.

RESULTS

When PRBC were stored for 42 days, the main changes to the cytoskeletal mesh included rupture of filaments, merger of small pores into larger ones, a decrease of the number of pores, thickening of filaments, and an increase of membrane stiffness. A process of irreversible changes to the cytoskeleton started on days 19-21. A kinetic model of changes in the parameters of the cytoskeletal mesh with time of PRBC storage was created.

DISCUSSION

Two stages of impairment in cytoskeletal elements were found: rupture of filaments and clustering of protein components. The typical time of development and specifics of these stages are discussed. The consequences of the altered configuration of the cytoskeleton are also discussed. Destruction of the red cell cytoskeleton can have a negative effect on the efficacy of blood transfusion and increase the risk of post-transfusion complications. Our findings can be used in clinical medicine to evaluate the quality of PRBC for blood transfusion as well as for studies of the molecular organisation of red cells undergoing various types of physical and chemical treatment.