Hypoxia induces robust ATP release from erythrocytes in ApoE-LDLR double-deficient mice.

Red blood cells (RBCs) play a role in the regulation of vascular tone via release of adenosine triphosphate (ATP) into the vasculature in response to various stimuli. Interestingly, ApoE/LDLR double-deficient (ApoE/LDLR) mice, a murine model of atherosclerosis, display a higher exercise capacity compared to the age-matched controls. However, it is not known whether increased exercise capacity in ApoE/LDLR mice is linked to the altered ATP release from RBCs.

Raman imaging unveils heme uptake in endothelial cells.

Heme released from damaged and senescent red blood cells (RBCs) may contribute to oxidant-mediated cell injury. One of the recently investigated physiological processes, essential in preventing the inflammatory impact of labile heme, is its uptake from the bloodstream by endothelial cells (ECs). In this study, we investigated heme uptake by ECs starting from the model studies on the in vitro cellular level, through the endothelium layer on the ex vivo murine aortic tissues.

Surface-enhanced Raman scattering (SERS) and tip-enhanced Raman scattering (TERS) in label-free characterization of erythrocyte membranes and extracellular vesicles at the nano-scale and molecular level.

The manuscript presents the potential of surface-enhanced Raman spectroscopy (SERS) and tip-enhanced Raman spectroscopy (TERS) for label-free characterization of extracellular microvesicles (EVs) and their isolated membranes derived from red blood cells (RBCs) at the nanoscale and at the single-molecule level, providing detection of a few individual amino acids, protein and lipid membrane compartments. The study shows future directions for research, such as investigating the use of the mentioned techniques for the detection and diagnosis of diseases. We demonstrate that SERS and TERS are powerful techniques for identifying the biochemical composition of EVs and their membranes, allowing the detection of small molecules, lipids, and proteins.

Reliable cell preparation protocol for Raman imaging to effectively differentiate normal leukocytes and leukemic blasts.

Leukemias are a remarkably diverse group of malignancies originating from abnormal progenitor cells in the bone marrow. Leukemia subtypes are classified according to the cell type that has undergone neoplastic transformation using demanding and time-consuming methods. Alternative is Raman imaging that can be used both for living and fixed cells.

Label-free testing strategy to evaluate packed red blood cell quality before transfusion to leukemia patients.

Patients worldwide require therapeutic transfusions of packed red blood cells (pRBCs), which is applied to the high-risk patients who need periodic transfusions due to leukemia, lymphoma, myeloma and other blood diseases or disorders. Contrary to the general hospital population where the transfusions are carried out mainly for healthy trauma patients, in case of high-risk patients the proper quality of pRBCs is crucial. This leads to an increased demand for efficient technology providing information on the pRBCs alterations deteriorating their quality.

Sulfhemoglobin under the spotlight - Detection and characterization of SHb and HbFe-SH.

Sulfhemoglobinemia is an incurable disease caused by an overdose of sulfur-containing drugs with oxidizing properties. Its diagnosis remains hindered due to the similarity of symptoms to other pathological state - methemoglobinemia, as well as contradictory information on the structure and characteristics of sulfhemoglobin. Herein, we present sulfhemoglobinemia model on living functional human erythrocytes, designed to recreate processes which could take place in a patient body in order to complement missing information and highlight distinctiveness of two hemoglobin (Hb) adducts formed after interaction with sulfur donors.

Secondary structure alterations of RBC assessed by FTIR-ATR in correlation to 2,3-DPG levels in ApoE/LDLR Mice.

In the present study, we characterized the secondary structure alterations of intact red blood cells (RBCs) cytosol with special attention to the sex-related alterations in 8- and 24-week-old female and male ApoE/LDLR mice, compared to age-matched female and male C57BL/6J control animals. Results were obtained with previously established methodology based on Fourier transform infrared spectroscopy-attenuated total reflectance (FTIR-ATR). Additionally, we evaluated 2,3-DPG levels in the RBCs and showed its potential link to the hemoglobin (Hb) secondary structure alterations.

Sex-Specific Differences of Adenosine Triphosphate Levels in Red Blood Cells Isolated From ApoE/LDLR Double-Deficient Mice.

In this study for the first time, we investigated the correlation between sex-specific differences in adenosine triphosphate (ATP) levels in red blood cells (RBCs) and their mechanical, biochemical, and morphological alterations during the progression of atherosclerosis in ApoE/LDLR double-deficient (ApoE/LDLR) mice. Our results indicate that both sex and age affect alterations in RBCs of both ApoE/LDLR and C57BL/6J mice. When compared with male RBCs, female RBCs were characterized by lower basal ATP and mean corpuscular hemoglobin concentration (MCHC), higher hemoglobin concentration (HGB), mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), deformability, and phosphatidylserine (PS) exposure levels, regardless of age in both, ApoE/LDLR and C57BL/6J mice.

Towards Raman-Based Screening of Acute Lymphoblastic Leukemia-Type B (B-ALL) Subtypes.

Acute lymphoblastic leukemia (ALL) is the most common type of malignant neoplasms in the pediatric population. B-cell precursor ALLs (BCP-ALLs) are derived from the progenitors of B lymphocytes. Traditionally, risk factors stratifying therapy in ALL patients included age at diagnosis, initial leukocytosis, and the response to chemotherapy.

Temporal relationship between systemic endothelial dysfunction and alterations in erythrocyte function in a murine model of chronic heart failure.

Aims: Endothelial dysfunction (ED) and red blood cell distribution width (RDW) are both prognostic factors in heart failure (HF), but the relationship between them is not clear. In this study, we used a unique mouse model of chronic HF driven by cardiomyocyte-specific overexpression of activated Gαq protein (Tgαq*44 mice) to characterize the relationship between the development of peripheral ED and the occurrence of structural nanomechanical and biochemical changes in red blood cells (RBCs).

Methods And Results: Systemic ED was detected in vivo in 8-month-old Tgαq*44 mice, as evidenced by impaired acetylcholine-induced vasodilation in the aorta and increased endothelial permeability in the brachiocephalic artery.

High-Resolution Fourier Transform Infrared (FT-IR) Spectroscopic Imaging for Detection of Lung Structures and Cancer-Related Abnormalities in a Murine Model.

Label-free molecular imaging is a promising utility to study tissues in terms of the identification of their compartments as well as chemical features and alterations induced by disease. The aim of this work was to assess if higher magnification of optics in the Fourier transform infrared (FT-IR) microscope coupled with the focal plane detector resulted in better resolution of lung structures and if the histopathological features correlated with clustering of spectral images. FT-IR spectroscopic imaging was performed on paraffinized lung tissue sections from mice with optics providing a total magnification of 61× and 36×.

Tauroursodeoxycholic Acid (TUDCA)-Lipid Interactions and Antioxidant Properties of TUDCA Studied in Model of Photoreceptor Membranes.

Tauroursodeoxycholic acid (TUDCA), a hydrophilic bile acid containing taurine conjugated with the ursodeoxycholic acid (UDCA), has been known and used from ancient times as a therapeutic compound in traditional Chinese medicine. TUDCA has recently been gaining significant interest as a neuroprotective agent, also exploited in the visual disorders. Among several mechanisms of TUDCA's protective action, its antioxidant activity and stabilizing effect on mitochondrial and plasma membranes are considered.

An Insight into the Stages of Ion Leakage during Red Blood Cell Storage.

Packed red blood cells (pRBCs), the most commonly transfused blood product, are exposed to environmental disruptions during storage in blood banks. In this study, temporal sequence of changes in the ion exchange in pRBCs was analyzed. Standard techniques commonly used in electrolyte measurements were implemented.

Spectroscopic Signature of Red Blood Cells in a D-Galactose-Induced Accelerated Aging Model.

This work presents a semi-quantitative spectroscopic approach, including FTIR-ATR and Raman spectroscopies, for the biochemical analysis of red blood cells (RBCs) supported by the biochemical, morphological and rheological reference techniques. This multi-modal approach provided the description of the RBC alterations at the molecular level in a model of accelerated aging induced by administration of D-galactose (D-gal), in comparison to natural aging. Such an approach allowed to conclude that most age-related biochemical RBC membrane changes (a decrease in lipid unsaturation and the level of phospholipids, or an increase in acyl chain shortening) as well as alterations in the morphological parameters and RBC deformability are well reflected in the D-gal model of accelerated aging.

Probing Heme Active Sites of Hemoglobin in Functional Red Blood Cells Using Resonance Raman Spectroscopy.

The UV-vis absorption, Raman imaging, and resonance Raman (rR) spectroscopy methods were employed to study cyanohemoglobin (HbCN) adducts inside living functional red blood cells (RBCs). The cyanide ligands are especially optically sensitive probes of the active site environment of heme proteins. The rR studies of HbCN and its isotopic analogues (CN, CN, and CN), as well as a careful deconvolution of spectral data, revealed that the ν(Fe-CN) stretching, δ(Fe-CN) bending, and ν(C≡N) stretching modes occur at 454, 382, and 2123 cm, respectively.

Age-related and atherosclerosis-related erythropathy in ApoE/LDLR mice.

In this work we applied a multimodal approach to define the age- and atherosclerosis-related biochemical and functional alterations in red blood cells (RBCs) in ApoE/LDLR mice. Our results revealed that age-related changes in RBCs, such as decreases in RBC deformability and mean height, were more pronounced in ApoE/LDLR mice than in age-matched control mice (C57BL/6J). The decreases in phospholipid content and level of lipid unsaturation were accompanied by an increase in cholesterol esters and esterified lipids in RBC membranes in aged C57BL/6J mice.

Irreversible alterations in the hemoglobin structure affect oxygen binding in human packed red blood cells.

The ability of hemoglobin (Hb) to transport respiratory gases is directly linked to its quaternary structure properties and reversible changes between T (tense) and R (relax) state. In this study we demonstrated that packed red blood cells (pRBCs) storage resulted in a gradual increase in the irreversible changes in the secondary and quaternary structures of Hb, with subsequent impairment of the T↔R transition. Such alteration was associated with the presence of irreversibly settled in the relaxed form, quaternary structure of Hb, which we termed R'.

Comparison of standard and HD FT-IR with multimodal CARS/TPEF/SHG/FLIMS imaging in the detection of the early stage of pulmonary metastasis of murine breast cancer.

Lungs, due to their high oxygen availability and vascularization, are an ideal environment for cancer cell migration, metastasis and tumour formation. These processes are directly connected with extracellular matrix (ECM) remodelling, resulting from cancer cell infiltration and preparation of the environment suitable for tumour growth. Herein, we compare the potential of fast, label-free and non-destructive methods of Fourier-transform infrared spectroscopy (FT-IR) in standard and high definition (HD) modes with nonlinear coherent anti-Stokes Raman scattering (CARS), second harmonic generation (SHG), two-photon excited fluorescence (TPEF) and a fluorescence lifetime imaging (FLIM) technique for lung metastasis detection.

Probing the structure-function relationship of hemoglobin in living human red blood cells.

Hemoglobin (Hb) is a key component of respiratory system and as such plays important role in human physiology. The studies of Hb's structure and functions are usually performed on cell-free protein; however, it has been shown that there are functionally relevant differences between isolated Hb and Hb present inside red blood cells (RBCs). It is clear that new experimental approaches are needed to understand the origin of these differences and to gain insight into the structure-function relationship of Hb within intact living cells.

Temporal sequence of the human RBCs' vesiculation observed in nano-scale with application of AFM and complementary techniques.

Based on the multimodal characterization of human red blood cells (RBCs), the link between the storage-related sequence of the nanoscale changes in RBC membranes in the relation to their biochemical profile as well as mechanical and functional properties was presented. On the background of the accumulation of RBCs waste products, programmed cell death and impaired rheological properties, progressive alterations in the RBC membranes including changes in their height and diameter as well as the in situ characterization of RBC-derived microparticles (RMPs) on the RBCs surface were presented. The advantage of atomic force microscopy (AFM) in RMPs visualization, even at the very early stage of vesiculation, was shown based on the results revealed by other reference techniques.

Tracking Extracellular Matrix Remodeling in Lungs Induced by Breast Cancer Metastasis. Fourier Transform Infrared Spectroscopic Studies.

This work focused on a detailed assessment of lung tissue affected by metastasis of breast cancer. We used large-area chemical scanning implemented in Fourier transform infrared (FTIR) spectroscopic imaging supported with classical histological and morphological characterization. For the first time, we differentiated and defined biochemical changes due to metastasis observed in the lung parenchyma, atelectasis, fibrous, and muscle cells, as well as bronchi ciliate cells, in a qualitative and semi-quantitative manner based on spectral features.

Multimodal detection and analysis of a new type of advanced Heinz body-like aggregate (AHBA) and cytoskeleton deformation in human RBCs.

A new type of aggregate, formed in human red blood cells (RBCs) in response to glutaraldehyde treatment, was discovered and analyzed with the classical and advanced biomolecular imaging techniques. Advanced Heinz body-like aggregates (AHBA) formed in a single human RBC are characterized by a higher level of hemoglobin (Hb) degradation compared to typical Heinz bodies, which consist of hemichromes. The complete destruction of the porphyrin structure of Hb and the aggregation of the degraded proteins in the presence of Fe ions are observed.

FTIR, Raman and AFM characterization of the clinically valid biochemical parameters of the thrombi in acute ischemic stroke.

The significance and utility of innovative imaging techniques in arterial clot analysis, which enable far more detailed and automated analysis compared to standard methods, are presented. The examination of two types of human thrombi is shown, representing the main ischemic stroke etiologies: fibrin-predominant clot of large vessel origin and red blood cells-rich clot of cardioembolic origin. The synergy effect of Fourier-transform infrared spectroscopy (FTIR), Raman spectroscopy (RS) and atomic force microscopy (AFM) techniques supported by chemometrics in comparison with reference histological staining was presented.