Rouleaux Formation of Live Human RBCs Affected by Oxygen and Heat

AbstractExtraction of biosurfactants from plants is advantageous than from microbes. The properties and robustness of biosurfactant derived from the mesocarp of Balanites aegyptiaca have been reported. However, the dark brown property of biosurfactant and lack of knowledge of its biocompatibility limits its scope. In the present work, the decolorization protocol for this biosurfactant was optimized using hydrogen peroxide. The hemolytic potential and biocompatibility based on cell toxicity and proliferation were also investigated. This study is the first report on the decolorization and toxicity assay of this biosurfactant. For decolorization of biosurfactant, 34 full factorial design was used, and the data were subjected to ANOVA. Results indicate that 1.5% of hydrogen peroxide can decolorize the biosurfactant most efficiently at 40 °C in 70 min at pH 7. Mitochondrial reductase (MTT) and reactive oxygen species (ROS) assays on M5S mouse skin fibroblast cells revealed that decolorized biosurfactant up to 50 µg/mL for 6 h had no significant toxic effect. Hemolysis assay showed ~ 2.5% hemolysis of human RBCs, indicating the nontoxic effect of this biosurfactant. The present work established a decolorization protocol making the biosurfactant chromatically acceptable. Biocompatibility assays confirm its safer use as observed by experiments on M5S skin fibroblast cells under in vitro conditions.

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Rhythmic glucose metabolism regulates the redox circadian clockwork in human red blood cells

Nature Communications ◽

10.1038/s41467-020-20479-4 ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Ratnasekhar Ch ◽

Guillaume Rey ◽

Sandipan Ray ◽

Pawan K. Jha ◽

Paul C. Driscoll ◽

...

Keyword(s):

Glucose Metabolism ◽

Red Blood Cells ◽

Blood Cells ◽

Mammalian Cells ◽

Metabolic Flux ◽

Pentose Phosphate ◽

Human Red Blood Cells ◽

Integral Process ◽

Metabolic Oscillations ◽

Human Rbcs

AbstractCircadian clocks coordinate mammalian behavior and physiology enabling organisms to anticipate 24-hour cycles. Transcription-translation feedback loops are thought to drive these clocks in most of mammalian cells. However, red blood cells (RBCs), which do not contain a nucleus, and cannot perform transcription or translation, nonetheless exhibit circadian redox rhythms. Here we show human RBCs display circadian regulation of glucose metabolism, which is required to sustain daily redox oscillations. We found daily rhythms of metabolite levels and flux through glycolysis and the pentose phosphate pathway (PPP). We show that inhibition of critical enzymes in either pathway abolished 24-hour rhythms in metabolic flux and redox oscillations, and determined that metabolic oscillations are necessary for redox rhythmicity. Furthermore, metabolic flux rhythms also occur in nucleated cells, and persist when the core transcriptional circadian clockwork is absent in Bmal1 knockouts. Thus, we propose that rhythmic glucose metabolism is an integral process in circadian rhythms.

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Evaluation of 4,4'-diisothiocyanatostilbene-2,2'-disulfonic acid in the inhibition of rouleaux formation

Transfusion ◽

10.1046/j.1537-2995.1996.36296181920.x ◽

1996 ◽

Vol 36 (2) ◽

pp. 109-112 ◽

Cited By ~ 4

Author(s):

SS Norris ◽

DD Allen ◽

TP Neff ◽

SL Wilkinson

Keyword(s):

Disulfonic Acid ◽

Rouleaux Formation

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Bat Red Blood Cells express Nucleic Acid Sensing Receptors and bind RNA and DNA

10.1101/2022.01.13.476238 ◽

2022 ◽

Author(s):

LK Metthew Lam ◽

Jane Dobkin ◽

Kaitlyn A. Eckart ◽

Ian Gereg ◽

Andrew DiSalvo ◽

...

Keyword(s):

Nucleic Acid ◽

Nucleic Acids ◽

Red Blood Cells ◽

Immune Function ◽

Blood Cells ◽

Toll Like Receptors ◽

Cpg Dna ◽

Human Rbcs ◽

Insight Into ◽

Rna And Dna

Red blood cells (RBCs) demonstrate immunomodulatory capabilities through the expression of nucleic acid sensors. Little is known about bat RBCs, and no studies have examined the immune function of bat erythrocytes. Here we show that bat RBCs express the nucleic acid-sensing Toll-like receptors TLR7 and TLR9 and bind the nucleic acid ligands, single-stranded RNA, and CpG DNA. Collectively, these data suggest that, like human RBCs, bat erythrocytes possess immune function and may be reservoirs for nucleic acids. These findings provide unique insight into bat immunity and may uncover potential mechanisms by which virulent pathogens in humans are concealed in bats.

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Inverse expression of Pk and Luke blood group antigens on human RBCs

Transfusion ◽

10.1046/j.1537-2995.2001.41070898.x ◽

2001 ◽

Vol 41 (7) ◽

pp. 898-907 ◽

Cited By ~ 11

Author(s):

Laura L. Cooling ◽

Kathleen Kelly

Keyword(s):

Blood Group ◽

Blood Group Antigens ◽

Human Rbcs

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Macrophages prevent human red blood cell reconstitution in immunodeficient mice

Blood ◽

10.1182/blood-2010-11-321414 ◽

2011 ◽

Vol 118 (22) ◽

pp. 5938-5946 ◽

Cited By ~ 84

Author(s):

Zheng Hu ◽

Nico Van Rooijen ◽

Yong-Guang Yang

Keyword(s):

Fetal Liver ◽

In Vivo Model ◽

Thymic Tissue ◽

Immunodeficient Mice ◽

Human Erythropoietin ◽

Human Cd34 ◽

Biologic Function ◽

Human Rbcs

Abstract An animal model supporting human erythropoiesis will be highly valuable for assessing the biologic function of human RBCs under physiologic and disease settings, and for evaluating protocols of in vitro RBC differentiation. Herein, we analyzed human RBC reconstitution in NOD/SCID or NOD/SCID/γc−/− mice that were transplanted with human CD34+ fetal liver cells and fetal thymic tissue. Although a large number of human CD45−CD71+ nucleated immature erythroid cells were detected in the bone marrow, human RBCs were undetectable in the blood of these mice. Human RBCs became detectable in blood after macrophage depletion but disappeared again after withdrawal of treatment. Furthermore, treatment with human erythropoietin and IL-3 significantly increased human RBC reconstitution in macrophage-depleted, but not control, humanized mice. Significantly more rapid rejection of human RBCs than CD47-deficient mouse RBCs indicates that mechanisms other than insufficient CD47-SIRPα signaling are involved in human RBC xenorejection in mice. All considered, our data demonstrate that human RBCs are highly susceptible to rejection by macrophages in immunodeficient mice. Thus, strategies for preventing human RBC rejection by macrophages are required for using immunodeficient mice as an in vivo model to study human erythropoiesis and RBC function.

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Indocyanine green angiography imaging findings in artery occlusions

European Journal of Ophthalmology ◽

10.1177/11206721211037832 ◽

2021 ◽

pp. 112067212110378

Author(s):

Ramesh Venkatesh ◽

Nikitha Gurram Reddy ◽

Vishma Prabhu ◽

Pukhraj Rishi ◽

Arpitha Pereira ◽

...

Keyword(s):

Indocyanine Green ◽

Multimodal Imaging ◽

Indocyanine Green Angiography ◽

Retinal Vessel ◽

Retinal Artery Occlusion ◽

Artery Occlusion ◽

Imaging Features ◽

Retinal Artery ◽

Choroidal Perfusion ◽

Rouleaux Formation

Purpose: To describe the multimodal imaging features including indocyanine green angiography (ICGA) in cases diagnosed clinically as central retinal artery occlusion (CRAO) at its different disease stages. Methods: In this retrospective observational study, patients diagnosed clinically as CRAO or hemi-CRAO were included. All patients underwent multimodal imaging with optical coherence tomography (OCT), fundus fluorescein angiography (FFA) and indocyanine green angiography (ICGA) were studied. Analysis of ICGA images in different stages of artery occlusions and its correlation with accompanying FFA and OCT images was done. Results: Eight such studies in five patients were available for analysis. The most important observation noted on ICGA was the presence of hypercyanescent spots seen during the acute stages of the disease in four of the five cases. The spots were accompanied by retinal vessel staining on FFA in the corresponding region. As the disease showed signs of resolution, the hypercyanescent spots on ICGA and retinal vessel staining on FFA disappeared. The hypercyanescent spots seen on the ICGA were noted due to the red blood cell aggregation or ‘rouleaux’ formation. In addition, choroidal perfusion abnormalities were noted on ICGA in all five cases in the acute stage. Conclusion: Choroidal perfusion changes can be identified in acute phase of retinal artery occlusion. Rouleaux formation in the retinal circulation occurs due to the slowing of the blood flow following artery occlusion. These are seen as hypercyanescent spots in the late phase on ICGA.

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Plasmodium falciparum Clag9-Associated PfRhopH Complex Is Involved in Merozoite Binding to Human Erythrocytes

Infection and Immunity ◽

10.1128/iai.00504-19 ◽

2019 ◽

Vol 88 (2) ◽

Author(s):

Bishwanath Kumar Chourasia ◽

Arunaditya Deshmukh ◽

Inderjeet Kaur ◽

Gourab Paul ◽

Ashutosh Panda ◽

...

Keyword(s):

Plasmodium Falciparum ◽

Cellular Localization ◽

Natural Infection ◽

Human Erythrocytes ◽

Spectrometric Analysis ◽

Endothelial Lining ◽

Content Type ◽

Protein Protein Interaction ◽

Associated Proteins ◽

Human Rbcs

ABSTRACT Cytoadherence-linked asexual gene 9 (Clag9), a conserved Plasmodium protein expressed during the asexual blood stages, is involved in the cytoadherence of infected red blood cells (RBCs) to the endothelial lining of blood vessels. Here, we show that Plasmodium falciparum Clag9 (PfClag9) is a component of the PfClag9-RhopH complex that is involved in merozoite binding to human erythrocytes. To characterize PfClag9, we expressed four fragments of PfClag9, encompassing the entire protein. Immunostaining analysis using anti-PfClag9 antibodies showed expression and localization of PfClag9 at the apical end of the merozoites. Mass spectrometric analysis of merozoite extracts after immunoprecipitation using anti-PfClag9 antibody identified P. falciparum rhoptry-associated protein 1 (PfRAP1), PfRAP2, PfRAP3, PfRhopH2, and PfRhopH3 as associated proteins. The identified rhoptry proteins were expressed, and their association with PfClag9 domains was assessed by using protein-protein interaction tools. We further showed that PfClag9 binds human RBCs by interacting with the glycophorin A-band 3 receptor-coreceptor complex. In agreement with its cellular localization, PfClag9 was strongly recognized by antibodies generated during natural infection. Mice immunized with the C-terminal domain of PfClag9 were partially protected against a subsequent challenge infection with Plasmodium berghei, further supporting a biological role of PfClag9 during natural infection. Taken together, these results provide direct evidence for the existence of a PfRhopH-Clag9 complex on the Plasmodium merozoite surface that binds to human RBCs.

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

Nanomedicine Nanotechnology Biology and Medicine ◽

10.1016/j.nano.2020.102221 ◽

2020 ◽

Vol 28 ◽

pp. 102221 ◽

Cited By ~ 1

Author(s):

Magdalena Kaczmarska ◽

Marek Grosicki ◽

Katarzyna Bulat ◽

Mateusz Mardyla ◽

Ewa Szczesny-Malysiak ◽

...

Keyword(s):

Temporal Sequence ◽

Nano Scale ◽

Complementary Techniques ◽

Human Rbcs

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Comparison of serum anti-band 3 and anti-Gal antibody binding to density-separated human red blood cells

Blood ◽

10.1182/blood.v77.3.628.628 ◽

1991 ◽

Vol 77 (3) ◽

pp. 628-636 ◽

Cited By ~ 25

Author(s):

MP Sorette ◽

U Galili ◽

MR Clark

Keyword(s):

Quantitative Relationship ◽

Band 3 ◽

T Antigen ◽

Low Ph ◽

High Density ◽

Structure Characteristic ◽

Binding Studies ◽

Serum Antibodies ◽

Human Rbcs

Abstract This study examines the quantitative relationship between two natural serum antibodies, anti-band 3 and anti-alpha-galactosyl (anti-Gal), in their capacity to bind to human red blood cell (RBC) populations separated on density gradients. The question was approached in two ways. First, we determined the extent of rebinding of affinity-purified human serum antibodies to RBCs that had been stripped of in situ antibody. Second, we eluted the in situ bound antibody at low pH from density-separated RBCs and determined the proportion of total eluted antibody that bound specifically to erythrocyte band 3 or to a Gal- alpha-(1,3)-Gal structure. Our results show that high-density human RBCs bind increased amounts of both antibodies. Anti-Gal rebinding was specific, because it was saturable and occurred in the presence of serum IgG depleted of anti-Gal. Binding assays using control natural autoantibodies directed against antigens not found on the RBC surface showed that high-density RBCs also bind increased amounts of these antibodies as compared with low-density RBCs. However, the extent of this binding is substantially lower than that of anti-band 3 and anti- Gal. Binding studies using the lectins Bandeiraea Simplicifolia (alpha- galactosyl specific) and Arachis Hypogaea (peanut agglutinin, beta- galactosyl specific) indicated that only the alpha-galactosyl sites are exposed on high density RBCs, and not the beta-galactosyl structure characteristic of T antigen. Antibody that is eluted at low pH from high density RBCs contains a 5.0% to 18.0% component that binds to band 3 protein, and a 9.1% to 39.0% component that recognizes the alpha- galactosyl structure. Together, the two antibodies appear to constitute an average of 35% (range 17.2% to 57.4%) of the in situ bound antibody from high-density human RBCs.

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