1
|
Böning D, Kuebler WM, Vogel D, Bloch W. The oxygen dissociation curve of blood in COVID-19-An update. Front Med (Lausanne) 2023; 10:1098547. [PMID: 36923010 PMCID: PMC10008909 DOI: 10.3389/fmed.2023.1098547] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Accepted: 02/03/2023] [Indexed: 03/02/2023] Open
Abstract
An impressive effect of the infection with SARS-Co-19 is the impairment of oxygen uptake due to lung injury. The reduced oxygen diffusion may potentially be counteracted by an increase in oxygen affinity of hemoglobin. However, hypoxia and anemia associated with COVID-19 usually decrease oxygen affinity due to a rise in [2,3-bisphosphoglycerate]. As such, COVID-19 related changes in the oxygen dissociation curve may be critical for oxygen uptake and supply, but are hard to predict. A Pubmed search lists 14 publications on oxygen affinity in COVID-19. While some investigations show no changes, three large studies found an increased affinity that was related to a good prognosis. Exact causes remain unknown. The cause of the associated anemia in COVID-19 is under discussion. Erythrocytes with structural alterations of membrane and cytoskeleton have been observed, and virus binding to Band 3 and also to ACE2 receptors in erythroblasts has been proposed. COVID-19 presentation is moderate in many subjects suffering from sickle cell disease. A possible explanation is that COVID-19 counteracts the unfavorable large right shift of the oxygen dissociation curve in these patients. Under discussion for therapy are mainly affinity-increasing drugs.
Collapse
Affiliation(s)
- Dieter Böning
- Institute of Physiology, Charité Medical University of Berlin, Berlin, Germany
| | - Wolfgang M. Kuebler
- Institute of Physiology, Charité Medical University of Berlin, Berlin, Germany
| | - Dominik Vogel
- Klinik für Interdisziplinäre Intensivmedizin, Vivantes Humboldt-Klinikum, Berlin, Germany
| | - Wilhelm Bloch
- Department of Molecular and Cellular Sport Medicine, Institute of Cardiovascular Research and Sport Medicine, German Sport University Cologne, Cologne, Germany
| |
Collapse
|
2
|
Shockley KR, Gupta S, Harris SF, Lahiri SN, Peddada SD. Quality Control of Quantitative High Throughput Screening Data. Front Genet 2019; 10:387. [PMID: 31143201 PMCID: PMC6520559 DOI: 10.3389/fgene.2019.00387] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2018] [Accepted: 04/10/2019] [Indexed: 01/08/2023] Open
Abstract
Quantitative high throughput screening (qHTS) experiments can generate 1000s of concentration-response profiles to screen compounds for potentially adverse effects. However, potency estimates for a single compound can vary considerably in study designs incorporating multiple concentration-response profiles for each compound. We introduce an automated quality control procedure based on analysis of variance (ANOVA) to identify and filter out compounds with multiple cluster response patterns and improve potency estimation in qHTS assays. Our approach, called Cluster Analysis by Subgroups using ANOVA (CASANOVA), clusters compound-specific response patterns into statistically supported subgroups. Applying CASANOVA to 43 publicly available qHTS data sets, we found that only about 20% of compounds with response values outside of the noise band have single cluster responses. The error rates for incorrectly separating true clusters and incorrectly clumping disparate clusters were both less than 5% in extensive simulation studies. Simulation studies also showed that the bias and variance of concentration at half-maximal response (AC50 ) estimates were usually within 10-fold when using a weighted average approach for potency estimation. In short, CASANOVA effectively sorts out compounds with "inconsistent" response patterns and produces trustworthy AC50 values.
Collapse
Affiliation(s)
- Keith R. Shockley
- Biostatistics and Computational Biology Branch, National Institute of Environmental Health Sciences, National Institutes of Health, Durham, NC, United States
| | - Shuva Gupta
- Statistics Department, University of Pennsylvania, Philadelphia, PA, United States
| | | | - Soumendra N. Lahiri
- Department of Statistics, North Carolina State University, Raleigh, NC, United States
| | - Shyamal D. Peddada
- Department of Biostatistics, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, PA, United States
| |
Collapse
|
3
|
Yasinska IM, Gonçalves Silva I, Sakhnevych SS, Ruegg L, Hussain R, Siligardi G, Fiedler W, Wellbrock J, Bardelli M, Varani L, Raap U, Berger S, Gibbs BF, Fasler-Kan E, Sumbayev VV. High mobility group box 1 (HMGB1) acts as an "alarmin" to promote acute myeloid leukaemia progression. Oncoimmunology 2018; 7:e1438109. [PMID: 29872582 PMCID: PMC5980411 DOI: 10.1080/2162402x.2018.1438109] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2017] [Revised: 01/30/2018] [Accepted: 02/02/2018] [Indexed: 02/08/2023] Open
Abstract
High mobility group box 1 (HMGB1) is a non-histone protein localised in the cell nucleus, where it interacts with DNA and promotes nuclear transcription events. HMGB1 levels are elevated during acute myeloid leukaemia (AML) progression followed by participation of this protein in triggering signalling events in target cells as a pro-inflammatory stimulus. This mechanism was hypothesised to be employed as a survival pathway by malignant blood cells and our aims were therefore to test this hypothesis experimentally. Here we report that HMGB1 triggers the release of tumour necrosis factor alpha (TNF-α) by primary human AML cells. TNF-α induces interleukin 1 beta (IL-1β) production by healthy leukocytes, leading to IL-1β-induced secretion of stem cell factor (SCF) by competent cells (for example endothelial cells). These results were verified in mouse bone marrow and primary human AML blood plasma samples. In addition, HMGB1 was found to induce secretion of angiogenic vascular endothelial growth factor (VEGF) and this process was dependent on the immune receptor Tim-3. We therefore conclude that HMGB1 is critical for AML progression as a ligand of Tim-3 and other immune receptors thus supporting survival/proliferation of AML cells and possibly the process of angiogenesis.
Collapse
Affiliation(s)
- Inna M Yasinska
- Medway School of Pharmacy, Universities of Kent and Greenwich, Chatham Maritime, United Kingdom
| | - Isabel Gonçalves Silva
- Medway School of Pharmacy, Universities of Kent and Greenwich, Chatham Maritime, United Kingdom
| | - Svetlana S Sakhnevych
- Medway School of Pharmacy, Universities of Kent and Greenwich, Chatham Maritime, United Kingdom
| | - Laura Ruegg
- Medway School of Pharmacy, Universities of Kent and Greenwich, Chatham Maritime, United Kingdom
| | | | | | - Walter Fiedler
- Department of Oncology, Hematology and Bone Marrow Transplantation with Section Pneumology, Hubertus Wald University Cancer Center, University Medical Center Hamburg-Eppendorf, Germany
| | - Jasmin Wellbrock
- Department of Oncology, Hematology and Bone Marrow Transplantation with Section Pneumology, Hubertus Wald University Cancer Center, University Medical Center Hamburg-Eppendorf, Germany
| | - Marco Bardelli
- Institute for Research in Biomedicine, Universita' della Svizzera italiana (USI), Bellinzona, Switzerland
| | - Luca Varani
- Institute for Research in Biomedicine, Universita' della Svizzera italiana (USI), Bellinzona, Switzerland
| | - Ulrike Raap
- Department of Medicine (Dermatology and Allergology), University of Oldenburg, Germany
| | - Steffen Berger
- Department of Pediatric Surgery and Department of Biomedical Research, Children's Hospital, Inselspital, University of Bern, Switzerland
| | - Bernhard F Gibbs
- Department of Medicine (Dermatology and Allergology), University of Oldenburg, Germany
- Medway School of Pharmacy, Universities of Kent and Greenwich, Chatham Maritime, United Kingdom
| | - Elizaveta Fasler-Kan
- Department of Pediatric Surgery and Department of Biomedical Research, Children's Hospital, Inselspital, University of Bern, Switzerland
- Department of Biomedicine, University Hospital Basel and University of Basel, Basel, Switzerland
| | - Vadim V Sumbayev
- Medway School of Pharmacy, Universities of Kent and Greenwich, Chatham Maritime, United Kingdom
| |
Collapse
|
4
|
Zot HG, Hasbun JE. Modeling Ca 2+-Bound Troponin in Excitation Contraction Coupling. Front Physiol 2016; 7:406. [PMID: 27708586 PMCID: PMC5030304 DOI: 10.3389/fphys.2016.00406] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2016] [Accepted: 08/30/2016] [Indexed: 11/25/2022] Open
Abstract
To explain disparate decay rates of cytosolic Ca2+ and structural changes in the thin filaments during a twitch, we model the time course of Ca2+-bound troponin (Tn) resulting from the free Ca2+ transient of fast skeletal muscle. In fibers stretched beyond overlap, the decay of Ca2+ as measured by a change in fluo-3 fluorescence is significantly slower than the intensity decay of the meridional 1/38.5 nm−1 reflection of Tn; this is not simply explained by considering only the Ca2+ binding properties of Tn alone (Matsuo et al., 2010). We apply a comprehensive model that includes the known Ca2+ binding properties of Tn in the context of the thin filament with and without cycling crossbridges. Calculations based on the model predict that the transient of Ca2+-bound Tn correlates with either the fluo-3 time course in muscle with overlapping thin and thick filaments or the intensity of the meridional 1/38.5 nm−1 reflection in overstretched muscle. Hence, cycling crossbridges delay the dissociation of Ca2+ from Tn. Correlation with the fluo-3 fluorescence change is not causal given that the transient of Ca2+-bound Tn depends on sarcomere length, whereas the fluo-3 fluorescence change does not. Transient positions of tropomyosin calculated from the time course of Ca2+-bound Tn are in reasonable agreement with the transient of measured perturbations of the Tn repeat in overlap and non-overlap muscle preparations.
Collapse
Affiliation(s)
- Henry G Zot
- Department of Biology, University of West Georgia Carrollton, GA, USA
| | - Javier E Hasbun
- Department of Physics, University of West Georgia Carrollton, GA, USA
| |
Collapse
|
5
|
Zot HG, Hasbun JE, Michell CA, Landim-Vieira M, Pinto JR. Enhanced troponin I binding explains the functional changes produced by the hypertrophic cardiomyopathy mutation A8V of cardiac troponin C. Arch Biochem Biophys 2016; 601:97-104. [PMID: 26976709 DOI: 10.1016/j.abb.2016.03.011] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2015] [Revised: 02/09/2016] [Accepted: 03/08/2016] [Indexed: 01/17/2023]
Abstract
Higher affinity for TnI explains how troponin C (TnC) carrying a causative hypertrophic cardiomyopathy mutation, TnC(A8V), sensitizes muscle cells to Ca(2+). Muscle fibers reconstituted with TnC(A8V) require ∼2.3-fold less [Ca(2+)] to achieve 50% maximum-tension compared to fibers reconstituted with wild-type TnC (TnC(WT)). Binding measurements rule out a significant change in N-terminus Ca(2+)-affinity of isolated TnC(A8V), and TnC(A8V) binds the switch-peptide of troponin-I (TnI(sp)) ∼1.6-fold more strongly than TnC(WT); thus we model the TnC-TnI(sp) interaction as competing with the TnI-actin interaction. Tension data are well-fit by a model constrained to conditions in which the affinity of TnC(A8V) for TnI(sp) is 1.5-1.7-fold higher than that of TnC(WT) at all [Ca(2+)]. Mean ATPase rates of reconstituted cardiac myofibrils is greater for TnC(A8V) than TnC(WT) at all [Ca(2+)], with statistically significant differences in the means at higher [Ca(2+)]. To probe TnC-TnI interaction in low Ca(2+), displacement of bis-ANS from TnI was monitored as a function of TnC. Whereas Ca(2+)-TnC(WT) displaces significantly more bis-ANS than Mg(2+)-TnC(WT), Ca(2+)-TnC(A8V) displaces probe equivalently to Mg(2+)-TnC(A8V) and Ca(2+)-TnC(WT), consistent with stronger Ca(2+)-independent TnC(A8V)-TnI(sp). A Matlab program for computing theoretical activation is reported. Our work suggests that contractility is constantly above normal in hearts made hypertrophic by TnC(A8V).
Collapse
Affiliation(s)
- Henry G Zot
- Department of Biology, University of West Georgia, Carrollton, GA 30118, USA.
| | - Javier E Hasbun
- Department of Physics, University of West Georgia, Carrollton, GA 30118, USA
| | - Clara A Michell
- Department of Biomedical Sciences, College of Medicine, Florida State University, Tallahassee, FL, USA
| | - Maicon Landim-Vieira
- Department of Biomedical Sciences, College of Medicine, Florida State University, Tallahassee, FL, USA
| | - Jose R Pinto
- Department of Biomedical Sciences, College of Medicine, Florida State University, Tallahassee, FL, USA.
| |
Collapse
|
6
|
Medina-Martel M, Urbina M, Fazzino F, Lima L. Serotonin transporter in lymphocytes of rats exposed to physical restraint stress. Neuroimmunomodulation 2013; 20:361-7. [PMID: 24022686 DOI: 10.1159/000353797] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/12/2013] [Accepted: 06/13/2013] [Indexed: 11/19/2022] Open
Abstract
OBJECTIVES Glucocorticoids and stress cause transcriptional and functional changes on the serotonin transporter (SERT) in the central nervous system. Stress can produce specific modifications of SERT in lymphocytes, which could be associated with alterations in immune response. The aim of this study was to evaluate the effect of a physical restraint stress protocol on (1) rat lymphocyte proliferation in the presence of the selective serotonin reuptake inhibitor fluoxetine and (2) SERT kinetic parameters, i.e. binding capacity (Bmax), affinity (Kd) and Hill coefficient (nH). METHODS Male adult Sprague-Dawley rats were placed in Plexiglass boxes (5 h daily for 5 days), and blood was obtained by cardiac puncture on day 6. Serum corticosterone was quantitated by an immunoenzymatic assay. Lymphocytes were isolated by density gradients and adhesion to plastic, of which there was sufficient material for further experiments, then cultured with or without the mitogen concanavalin A (Con A, 2 μg/ml) and fluoxetine (1-50 μM). Cell proliferation was measured with tetrazolium salts, and [(3)H]paroxetine was used as a SERT-specific ligand for binding assays. RESULTS Restraint produced a significant increase in serum corticosterone of stressed rats. The proliferative response to Con A was similar in the controls and stressed animals. Fluoxetine reduced cell proliferation with and without Con A. Restraint diminished the inhibitory effect of fluoxetine on proliferation. Restraint also increased Bmax and Kd, but decreased nH. Treatment of rats with actinomycin D, a transcription inhibitor, reduced Bmax in stressed animals. CONCLUSIONS Restraint stress modulated the effect of fluoxetine on cell proliferation, probably through the modification of the presence and the function of SERT.
Collapse
Affiliation(s)
- Matilde Medina-Martel
- Laboratorio de Neuroquímica, Centro de Biofísica y Bioquímica, Instituto Venezolano de Investigaciones Científicas, Caracas, Venezuela
| | | | | | | |
Collapse
|