1
|
Amoudruz L, Economides A, Koumoutsakos P. The volume of healthy red blood cells is optimal for advective oxygen transport in arterioles. Biophys J 2024; 123:1289-1296. [PMID: 38641875 PMCID: PMC11140464 DOI: 10.1016/j.bpj.2024.04.015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2023] [Revised: 02/05/2024] [Accepted: 04/15/2024] [Indexed: 04/21/2024] Open
Abstract
Red blood cells (RBCs) are vital for transporting oxygen from the lungs to the body's tissues through the intricate circulatory system. They achieve this by binding and releasing oxygen molecules to the abundant hemoglobin within their cytosol. The volume of RBCs affects the amount of oxygen they can carry, yet whether this volume is optimal for transporting oxygen through the circulatory system remains an open question. This study explores, through high-fidelity numerical simulations, the impact of RBC volume on advective oxygen transport efficiency through arterioles, which form the area of greatest flow resistance in the circulatory system. The results show that, strikingly, RBCs with volumes similar to those found in vivo are most efficient to transport oxygen through arterioles. The flow resistance is related to the cell-free layer thickness, which is influenced by the shape and the motion of the RBCs: at low volumes, RBCs deform and fold, while at high volumes, RBCs collide and follow more diffuse trajectories. In contrast, RBCs with a healthy volume maximize the cell-free layer thickness, resulting in a more efficient advective transport of oxygen.
Collapse
Affiliation(s)
- Lucas Amoudruz
- Computational Science and Engineering Laboratory, School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts
| | - Athena Economides
- Institute of Neuropathology, University of Zurich, 8091 Zurich, Switzerland
| | - Petros Koumoutsakos
- Computational Science and Engineering Laboratory, School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts.
| |
Collapse
|
2
|
Dumbill R, Rabcuka J, Fallon J, Knight S, Hunter J, Voyce D, Barrett J, Ellen M, Weissenbacher A, Kurniawan T, Blonski S, Korczyk PM, Ploeg R, Coussios C, Friend P, Swietach P. Impaired O2 unloading from stored blood results in diffusion-limited O2 release at tissues: evidence from human kidneys. Blood 2024; 143:721-733. [PMID: 38048591 PMCID: PMC10900257 DOI: 10.1182/blood.2023022385] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2023] [Revised: 10/26/2023] [Accepted: 11/03/2023] [Indexed: 12/06/2023] Open
Abstract
ABSTRACT The volume of oxygen drawn from systemic capillaries down a partial pressure gradient is determined by the oxygen content of red blood cells (RBCs) and their oxygen-unloading kinetics, although the latter is assumed to be rapid and, therefore, not a meaningful factor. Under this paradigm, oxygen transfer to tissues is perfusion-limited. Consequently, clinical treatments to optimize oxygen delivery aim at improving blood flow and arterial oxygen content, rather than RBC oxygen handling. Although the oxygen-carrying capacity of blood is increased with transfusion, studies have shown that stored blood undergoes kinetic attrition of oxygen release, which may compromise overall oxygen delivery to tissues by causing transport to become diffusion-limited. We sought evidence for diffusion-limited oxygen release in viable human kidneys, normothermically perfused with stored blood. In a cohort of kidneys that went on to be transplanted, renal respiration correlated inversely with the time-constant of oxygen unloading from RBCs used for perfusion. Furthermore, the renal respiratory rate did not correlate with arterial O2 delivery unless this factored the rate of oxygen-release from RBCs, as expected from diffusion-limited transport. To test for a rescue effect, perfusion of kidneys deemed unsuitable for transplantation was alternated between stored and rejuvenated RBCs of the same donation. This experiment controlled oxygen-unloading, without intervening ischemia, holding all non-RBC parameters constant. Rejuvenated oxygen-unloading kinetics improved the kidney's oxygen diffusion capacity and increased cortical oxygen partial pressure by 60%. Thus, oxygen delivery to tissues can become diffusion-limited during perfusion with stored blood, which has implications in scenarios, such as ex vivo organ perfusion, major hemorrhage, and pediatric transfusion. This trial was registered at www.clinicaltrials.gov as #ISRCTN13292277.
Collapse
Affiliation(s)
- Richard Dumbill
- Nuffield Department of Surgery, University of Oxford, Oxford, United Kingdom
- Oxford Transplant Centre, Oxford University Hospitals NHS Foundation Trust, Oxford, United Kingdom
| | - Julija Rabcuka
- Department of Physiology, Anatomy & Genetics, University of Oxford, Oxford, United Kingdom
| | - John Fallon
- Nuffield Department of Surgery, University of Oxford, Oxford, United Kingdom
- Oxford Transplant Centre, Oxford University Hospitals NHS Foundation Trust, Oxford, United Kingdom
| | - Simon Knight
- Nuffield Department of Surgery, University of Oxford, Oxford, United Kingdom
- Oxford Transplant Centre, Oxford University Hospitals NHS Foundation Trust, Oxford, United Kingdom
| | - James Hunter
- Nuffield Department of Surgery, University of Oxford, Oxford, United Kingdom
- University Hospitals Coventry and Warwickshire NHS Trust, Coventry, United Kingdom
| | | | | | | | - Annemarie Weissenbacher
- Department of Visceral, Transplant and Thoracic Surgery, Center of Operative Medicine, Medical University of Innsbruck, Innsbruck, Austria
| | - Tetuko Kurniawan
- Institute of Fundamental Technological Research, Polish Academy of Sciences, Warsaw, Poland
- President University, Kota Jababeka, Bekasi, Indonesia
| | - Slawomir Blonski
- Institute of Fundamental Technological Research, Polish Academy of Sciences, Warsaw, Poland
| | - Piotr Michal Korczyk
- Institute of Fundamental Technological Research, Polish Academy of Sciences, Warsaw, Poland
| | - Rutger Ploeg
- Nuffield Department of Surgery, University of Oxford, Oxford, United Kingdom
- Oxford Transplant Centre, Oxford University Hospitals NHS Foundation Trust, Oxford, United Kingdom
| | - Constantin Coussios
- OrganOx Limited, Oxford, United Kingdom
- Institute of Biomedical Engineering, University of Oxford, Oxford, United Kingdom
| | - Peter Friend
- Nuffield Department of Surgery, University of Oxford, Oxford, United Kingdom
- Oxford Transplant Centre, Oxford University Hospitals NHS Foundation Trust, Oxford, United Kingdom
- OrganOx Limited, Oxford, United Kingdom
| | - Pawel Swietach
- Department of Physiology, Anatomy & Genetics, University of Oxford, Oxford, United Kingdom
| |
Collapse
|
3
|
Bedggood P, Ding Y, Metha A. Changes to the shape, orientation and packing of red cells as a function of retinal capillary size. BIOMEDICAL OPTICS EXPRESS 2024; 15:558-578. [PMID: 38404337 PMCID: PMC10890884 DOI: 10.1364/boe.511093] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/02/2023] [Revised: 12/13/2023] [Accepted: 12/18/2023] [Indexed: 02/27/2024]
Abstract
The free diameter of a red blood cell exceeds the lumen diameter of capillaries in the central nervous system, requiring significant deformation of cells. However the deformations undertaken in vivo are not well established due to the difficulty in observing cellular capillary flow in living human tissue. Here, we used high resolution adaptive optics imaging to non-invasively track 17,842 red blood cells in transit through 121 unique capillary segments of diameter 8 µm or less in the retina of 3 healthy human subjects. Within each vessel, a 2D en face profile was generated for the "average cell", whose shape was then inferred in 3D based on the key assumption of a circular capillary cross-section. From this we estimated the average volume, surface area, orientation, and separation between red cells within each capillary tube. Our results showed a network filtration effect, whereby narrower vessels were more likely to contain smaller cells (defined by surface area, which is thought not to vary during a cell's passage through the vascular system). A bivariate linear model showed that for larger cells in narrower vessels: cells re-orient themselves to align with the flow axis, their shape becomes more elongated, there are longer gaps between successive cells, and remarkably, that cell volume is less which implies the ejection of water from cells to facilitate capillary transit. Taken together, these findings suggest that red cells pass through retinal capillaries with some reluctance. A biphasic distribution for cell orientation and separation was evident, indicating a "tipping point" for vessels narrower than approx. 5 µm. This corresponds closely to the typical capillary lumen diameter, and may maximize sensitivity of cellular flow to small changes in diameter. We suggest that the minimization of unnecessary oxygen exchange, and hence of damage via reactive oxygen pathways, may have provided evolutionary pressure to ensure that capillary lumens are generally narrower than red blood cells.
Collapse
Affiliation(s)
- Phillip Bedggood
- Department of Optometry and Vision Sciences, The University of Melbourne, 3010, Australia
| | - Yifu Ding
- Department of Optometry and Vision Sciences, The University of Melbourne, 3010, Australia
| | - Andrew Metha
- Department of Optometry and Vision Sciences, The University of Melbourne, 3010, Australia
| |
Collapse
|
4
|
Blaszczak W, White B, Monterisi S, Swietach P. Dynamic IL-6R/STAT3 signaling leads to heterogeneity of metabolic phenotype in pancreatic ductal adenocarcinoma cells. Cell Rep 2024; 43:113612. [PMID: 38141171 PMCID: PMC11149489 DOI: 10.1016/j.celrep.2023.113612] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Revised: 09/29/2023] [Accepted: 12/07/2023] [Indexed: 12/25/2023] Open
Abstract
Malignancy is enabled by pro-growth mutations and adequate energy provision. However, global metabolic activation would be self-terminating if it depleted tumor resources. Cancer cells could avoid this by rationing resources, e.g., dynamically switching between "baseline" and "activated" metabolic states. Using single-cell metabolic phenotyping of pancreatic ductal adenocarcinoma cells, we identify MIA-PaCa-2 as having broad heterogeneity of fermentative metabolism. Sorting by a readout of lactic acid permeability separates cells by fermentative and respiratory rates. Contrasting phenotypes persist for 4 days and are unrelated to cell cycling or glycolytic/respiratory gene expression; however, transcriptomics links metabolically active cells with interleukin-6 receptor (IL-6R)-STAT3 signaling. We verify this by IL-6R/STAT3 knockdowns and sorting by IL-6R status. IL-6R/STAT3 activates fermentation and transcription of its inhibitor, SOCS3, resulting in delayed negative feedback that underpins transitions between metabolic states. Among cells manifesting wide metabolic heterogeneity, dynamic IL-6R/STAT3 signaling may allow cell cohorts to take turns in progressing energy-intense processes without depleting shared resources.
Collapse
Affiliation(s)
- Wiktoria Blaszczak
- Department of Physiology, Anatomy & Genetics, University of Oxford, Sherrington Building, Parks Road, OX1 3PT Oxford, UK
| | - Bobby White
- Department of Physiology, Anatomy & Genetics, University of Oxford, Sherrington Building, Parks Road, OX1 3PT Oxford, UK
| | - Stefania Monterisi
- Department of Physiology, Anatomy & Genetics, University of Oxford, Sherrington Building, Parks Road, OX1 3PT Oxford, UK
| | - Pawel Swietach
- Department of Physiology, Anatomy & Genetics, University of Oxford, Sherrington Building, Parks Road, OX1 3PT Oxford, UK.
| |
Collapse
|
5
|
Cremin K, Meloni GN, Valavanis D, Soyer OS, Unwin PR. Can Single Cell Respiration be Measured by Scanning Electrochemical Microscopy (SECM)? ACS MEASUREMENT SCIENCE AU 2023; 3:361-370. [PMID: 37868362 PMCID: PMC10588932 DOI: 10.1021/acsmeasuresciau.3c00019] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/27/2023] [Revised: 06/13/2023] [Accepted: 06/13/2023] [Indexed: 10/24/2023]
Abstract
Ultramicroelectrode (UME), or, equivalently, microelectrode, probes are increasingly used for single-cell measurements of cellular properties and processes, including physiological activity, such as metabolic fluxes and respiration rates. Major challenges for the sensitivity of such measurements include: (i) the relative magnitude of cellular and UME fluxes (manifested in the current); and (ii) issues around the stability of the UME response over time. To explore the extent to which these factors impact the precision of electrochemical cellular measurements, we undertake a systematic analysis of measurement conditions and experimental parameters for determining single cell respiration rates via the oxygen consumption rate (OCR) in single HeLa cells. Using scanning electrochemical microscopy (SECM), with a platinum UME as the probe, we employ a self-referencing measurement protocol, rarely employed in SECM, whereby the UME is repeatedly approached from bulk solution to a cell, and a short pulse to oxygen reduction reaction (ORR) potential is performed near the cell and in bulk solution. This approach enables the periodic tracking of the bulk UME response to which the near-cell response is repeatedly compared (referenced) and also ensures that the ORR near the cell is performed only briefly, minimizing the effect of the electrochemical process on the cell. SECM experiments are combined with a finite element method (FEM) modeling framework to simulate oxygen diffusion and the UME response. Taking a realistic range of single cell OCR to be 1 × 10-18 to 1 × 10-16 mol s-1, results from the combination of FEM simulations and self-referencing SECM measurements show that these OCR values are at, or below, the present detection sensitivity of the technique. We provide a set of model-based suggestions for improving these measurements in the future but highlight that extraordinary improvements in the stability and precision of SECM measurements will be required if single cell OCR measurements are to be realized.
Collapse
Affiliation(s)
- Kelsey Cremin
- Bio-Electrical
Engineering Innovation Hub, Department of Chemistry, Molecular Analytical
Science Centre for Doctoral Training (MAS CDT), School of Life Sciences, the University of Warwick, Coventry CV4 7AL, United Kingdom
| | - Gabriel N. Meloni
- Bio-Electrical
Engineering Innovation Hub, Department of Chemistry, Molecular Analytical
Science Centre for Doctoral Training (MAS CDT), School of Life Sciences, the University of Warwick, Coventry CV4 7AL, United Kingdom
| | - Dimitrios Valavanis
- Bio-Electrical
Engineering Innovation Hub, Department of Chemistry, Molecular Analytical
Science Centre for Doctoral Training (MAS CDT), School of Life Sciences, the University of Warwick, Coventry CV4 7AL, United Kingdom
| | - Orkun S. Soyer
- Bio-Electrical
Engineering Innovation Hub, Department of Chemistry, Molecular Analytical
Science Centre for Doctoral Training (MAS CDT), School of Life Sciences, the University of Warwick, Coventry CV4 7AL, United Kingdom
| | - Patrick R. Unwin
- Bio-Electrical
Engineering Innovation Hub, Department of Chemistry, Molecular Analytical
Science Centre for Doctoral Training (MAS CDT), School of Life Sciences, the University of Warwick, Coventry CV4 7AL, United Kingdom
| |
Collapse
|
6
|
Christie JR, Kong I, Mawdsley L, Milkovich S, Doornekamp A, Baek J, Fraser GM, Ellis CG, Sové RJ. Optical method to determine in vivo capillary hematocrit, hemoglobin concentration, and 3-D network geometry in skeletal muscle. Microcirculation 2022; 29:e12751. [PMID: 35146836 DOI: 10.1111/micc.12751] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2021] [Revised: 12/18/2021] [Accepted: 02/02/2022] [Indexed: 12/30/2022]
Abstract
OBJECTIVE The aim of this study was to develop a tool to visualize and quantify hemodynamic information, such as hemoglobin concentration and hematocrit, within microvascular networks recorded in vivo using intravital video microscopy. Additionally, we aimed to facilitate the 3-D reconstruction of the microvascular networks. METHODS Digital images taken from an intravital video microscopy preparation of the extensor digitorum longus muscle in rats for 25 capillary segments were used. The developed algorithm was used to delineate capillaries of interest, calculate the optical density for each pixel in the image, and reconstruct the 3-D capillary geometry using the calculated light path-lengths. Subsequently, the mean corpuscular hemoglobin concentration (MCHC), hemoglobin concentration, and hematocrit for these capillaries were calculated. We evaluated the hematocrit values determined by our methodology by comparing them to those obtained using a previously published method. RESULTS The hematocrit values from the proposed optical method were strongly correlated with those calculated using published methods r2 (25) = .92, p < .001, and demonstrated excellent agreement with a mean difference of 1.3% and a coefficient of variation (CV) of 11%. The average MCHC, hemoglobin concentration, and light path-lengths were 23.83 g/dl, 8.06 g/dl, and 3.92 µm, respectively. CONCLUSION The proposed methodology can quantify hemodynamic measurements and produce functional images for visualization of the microcirculation in vivo.
Collapse
Affiliation(s)
- Jaryd R Christie
- Department of Medical Biophysics, University of Western Ontario, London, Ontario, Canada
| | - Isaac Kong
- Division of Radiation Oncology, Department of Oncology, Juravinski Cancer Centre, McMaster University, Hamilton, Ontario, Canada
| | - Laura Mawdsley
- Department of Medical Biophysics, University of Western Ontario, London, Ontario, Canada.,Robarts Research Institute, University of Western Ontario, London, Ontario, Canada
| | - Stephanie Milkovich
- Department of Medical Biophysics, University of Western Ontario, London, Ontario, Canada.,Robarts Research Institute, University of Western Ontario, London, Ontario, Canada
| | - Ande Doornekamp
- Department of Medical Biophysics, University of Western Ontario, London, Ontario, Canada
| | - Jason Baek
- Temerty Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
| | - Graham M Fraser
- Division of BioMedical Sciences, Memorial University of Newfoundland, St. John's, NL, Canada
| | - Christopher G Ellis
- Department of Medical Biophysics, University of Western Ontario, London, Ontario, Canada.,Robarts Research Institute, University of Western Ontario, London, Ontario, Canada
| | - Richard J Sové
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, Maryland, USA
| |
Collapse
|
7
|
Autoregulation of H +/lactate efflux prevents monocarboxylate transport (MCT) inhibitors from reducing glycolytic lactic acid production. Br J Cancer 2022; 127:1365-1377. [PMID: 35840734 PMCID: PMC9519749 DOI: 10.1038/s41416-022-01910-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2022] [Revised: 06/24/2022] [Accepted: 06/29/2022] [Indexed: 12/02/2022] Open
Abstract
Background Pharmacological inhibition of membrane transporters is expected to reduce the flow of solutes, unless flux is restored (i.e., autoregulated) through a compensatory increase in the transmembrane driving force. Drugs acting on monocarboxylate transporters (MCTs) have been developed to disrupt glycolytic metabolism, but autoregulation would render such interventions ineffective. We evaluated whether small-molecule MCT inhibitors reduce cellular H+/lactate production. Methods Cellular assays measured the relationship between MCT activity (expressed as membrane H+/lactate permeability; PHLac) and lactic acid production (inferred from H+ and lactate excretion; JHLac) in a panel of pancreatic ductal adenocarcinoma (PDAC) cells spanning a range of glycolytic phenotype. Results MCT activity did not correlate with lactic acid production, indicating that it is not set by membrane permeability properties. MCT inhibitors did not proportionately reduce JHLac because of a compensatory increase in the transmembrane [lactate] driving force. JHLac was largely insensitive to [lactate], therefore its cytoplasmic build-up upon MCT inhibition does not hinder glycolytic production. Extracellular acidity, an MCT inhibitor, reduced JHLac but this was via cytoplasmic acidification blocking glycolytic enzymes. Conclusions We provide mathematically verified evidence that pharmacological and physiological modulators of MCTs cannot proportionately reduce lactic acid production because of the stabilising effect of autoregulation on overall flux.
Collapse
|
8
|
Metabolic reprogramming under hypoxic storage preserves faster oxygen unloading from stored red blood cells. Blood Adv 2022; 6:5415-5428. [PMID: 35736672 DOI: 10.1182/bloodadvances.2022007774] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2022] [Accepted: 06/11/2022] [Indexed: 11/20/2022] Open
Abstract
Stored red blood cells (RBCs) incur biochemical and morphological changes, collectively termed the storage lesion. Functionally, the storage lesion manifests as slower oxygen unloading from RBCs, which may compromise the efficacy of transfusions where the clinical imperative is to rapidly boost oxygen delivery to tissues. Recent analysis of large real-world data linked longer storage with increased recipient mortality. Biochemical rejuvenation with a formulation of adenosine, inosine, and pyruvate can restore gas-handling properties, but its implementation is impractical for most clinical scenarios. We tested whether storage under hypoxia, previously shown to slow biochemical degradation, also preserves gas-handling properties of RBCs. A microfluidic chamber, designed to rapidly switch between oxygenated and anoxic superfusates, was used for single-cell oxygen saturation imaging on samples stored for up to 49 days. Aliquots were also analyzed flow-cytometrically for side-scatter (a proposed proxy of O2 unloading kinetics), metabolomics, lipidomics and redox proteomics. For benchmarking, units were biochemically rejuvenated at four weeks of standard storage. Hypoxic storage hastened O2 unloading in units stored to 35 days, an effect that correlated with side-scatter but was not linked to post-translational modifications of hemoglobin. Although hypoxic storage and rejuvenation produced distinct biochemical changes, a subset of metabolites including pyruvate, sedoheptulose 1-phosphate, and 2/3 phospho-D-glycerate, was a common signature that correlated with changes in O2 unloading. Correlations between gas-handling and lipidomic changes were modest. Thus, hypoxic storage of RBCs preserves key metabolic pathways and O2 exchange properties, thereby improving the functional quality of blood products and potentially influencing transfusion outcomes.
Collapse
|
9
|
Jennings ML. Cell Physiology and Molecular Mechanism of Anion Transport by Erythrocyte Band 3/AE1. Am J Physiol Cell Physiol 2021; 321:C1028-C1059. [PMID: 34669510 PMCID: PMC8714990 DOI: 10.1152/ajpcell.00275.2021] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The major transmembrane protein of the red blood cell, known as band 3, AE1, and SLC4A1, has two main functions: 1) catalysis of Cl-/HCO3- exchange, one of the steps in CO2 excretion; 2) anchoring the membrane skeleton. This review summarizes the 150 year history of research on red cell anion transport and band 3 as an experimental system for studying membrane protein structure and ion transport mechanisms. Important early findings were that red cell Cl- transport is a tightly coupled 1:1 exchange and band 3 is labeled by stilbenesulfonate derivatives that inhibit anion transport. Biochemical studies showed that the protein is dimeric or tetrameric (paired dimers) and that there is one stilbenedisulfonate binding site per subunit of the dimer. Transport kinetics and inhibitor characteristics supported the idea that the transporter acts by an alternating access mechanism with intrinsic asymmetry. The sequence of band 3 cDNA provided a framework for detailed study of protein topology and amino acid residues important for transport. The identification of genetic variants produced insights into the roles of band 3 in red cell abnormalities and distal renal tubular acidosis. The publication of the membrane domain crystal structure made it possible to propose concrete molecular models of transport. Future research directions include improving our understanding of the transport mechanism at the molecular level and of the integrative relationships among band 3, hemoglobin, carbonic anhydrase, and gradients (both transmembrane and subcellular) of HCO3-, Cl-, O2, CO2, pH, and NO metabolites during pulmonary and systemic capillary gas exchange.
Collapse
Affiliation(s)
- Michael L Jennings
- Department of Physiology and Cell Biology, University of Arkansas for Medical Sciences, Little Rock, Arkansas, United States
| |
Collapse
|
10
|
Donovan K, Meli A, Cendali F, Park KC, Cardigan R, Stanworth S, McKechnie S, D’Alessandro A, Smethurst PA, Swietach P. Stored blood has compromised oxygen unloading kinetics that can be normalized with rejuvenation and predicted from corpuscular side-scatter. Haematologica 2021; 107:298-302. [PMID: 34498445 PMCID: PMC8719080 DOI: 10.3324/haematol.2021.279296] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2021] [Indexed: 01/07/2023] Open
Affiliation(s)
- Killian Donovan
- Department of Physiology, Anatomy & Genetics, University of Oxford, Oxford, UK
| | - Athinoula Meli
- Component Development Laboratory, NHS Blood and Transplant, Cambridge, UK
| | - Francesca Cendali
- Department of Biochemistry and Molecular Genetics, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - Kyung Chan Park
- Department of Physiology, Anatomy & Genetics, University of Oxford, Oxford, UK
| | - Rebecca Cardigan
- Component Development Laboratory, NHS Blood and Transplant, Cambridge, UK,Department of Haematology, University of Cambridge, Cambridge, UK
| | - Simon Stanworth
- Transfusion Medicine, NHS Blood and Transplant, Oxford, UK,Department of Haematology, Oxford University Hospitals NHS Foundation Trust, Oxford, UK,Radcliffe Department of Medicine, University of Oxford, and Oxford BRC Haematology Theme, Oxford, UK
| | - Stuart McKechnie
- Adult Intensive Care Unit, John Radcliffe Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford, UK
| | - Angelo D’Alessandro
- Department of Biochemistry and Molecular Genetics, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - Peter A. Smethurst
- Component Development Laboratory, NHS Blood and Transplant, Cambridge, UK
| | - Pawel Swietach
- Department of Physiology, Anatomy & Genetics, University of Oxford, Oxford, UK,PAWEL SWIETACH -
| |
Collapse
|
11
|
Vu C, Bush A, Choi S, Borzage M, Miao X, Nederveen AJ, Coates TD, Wood JC. Reduced global cerebral oxygen metabolic rate in sickle cell disease and chronic anemias. Am J Hematol 2021; 96:901-913. [PMID: 33891719 DOI: 10.1002/ajh.26203] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2021] [Revised: 04/19/2021] [Accepted: 04/21/2021] [Indexed: 12/18/2022]
Abstract
Anemia is the most common blood disorder in the world. In patients with chronic anemia, such as sickle cell disease or major thalassemia, cerebral blood flow increases to compensate for decreased oxygen content. However, the effects of chronic anemia on oxygen extraction fraction (OEF) and cerebral metabolic rate of oxygen (CMRO2 ) are less well understood. In this study, we examined 47 sickle-cell anemia subjects (age 21.7 ± 7.1, female 45%), 27 non-sickle anemic subjects (age 25.0 ± 10.4, female 52%) and 44 healthy controls (age 26.4 ± 10.6, female 71%) using MRI metrics of brain oxygenation and flow. Phase contrast MRI was used to measure resting cerebral blood flow, while T2 -relaxation-under-spin-tagging (TRUST) MRI with disease appropriate calibrations were used to measure OEF and CMRO2 . We observed that patients with sickle cell disease and other chronic anemias have decreased OEF and CMRO2 (respectively 27.4 ± 4.1% and 3.39 ± 0.71 ml O2 /100 g/min in sickle cell disease, 30.8 ± 5.2% and 3.53 ± 0.64 ml O2 /100 g/min in other anemias) compared to controls (36.7 ± 6.0% and 4.00 ± 0.65 ml O2 /100 g/min). Impaired CMRO2 was proportional to the degree of anemia severity. We further demonstrate striking concordance of the present work with pooled historical data from patients having broad etiologies for their anemia. The reduced cerebral oxygen extraction and metabolism are consistent with emerging data demonstrating increased non-nutritive flow, or physiological shunting, in sickle cell disease patients.
Collapse
Affiliation(s)
- Chau Vu
- Department of Biomedical Engineering University of Southern California Los Angeles California USA
| | - Adam Bush
- Department of Biomedical Engineering University of Southern California Los Angeles California USA
- Department of Radiology Stanford University Stanford California USA
| | - Soyoung Choi
- Neuroscience Graduate Program University of Southern California Los Angeles California USA
| | - Matthew Borzage
- Division of Neonatology, Fetal and Neonatal Institute Children's Hospital Los Angeles Los Angeles California USA
- Department of Pediatrics, Keck School of Medicine University of Southern California Los Angeles California USA
| | - Xin Miao
- Department of Biomedical Engineering University of Southern California Los Angeles California USA
| | - Aart J. Nederveen
- University of Amsterdam, Amsterdam UMC, Radiology and Nuclear Medicine Amsterdam The Netherlands
| | - Thomas D. Coates
- Division of Hematology‐Oncology, Department of Pediatrics Children's Hospital Los Angeles Los Angeles California USA
- Departments of Pediatrics and Pathology, Keck School of Medicine University of Southern California Los Angeles California USA
| | - John C. Wood
- Department of Biomedical Engineering University of Southern California Los Angeles California USA
- Division of Cardiology, Departments of Pediatrics and Radiology Children's Hospital Los Angeles Los Angeles California USA
| |
Collapse
|
12
|
C G, Shetty S, Bharati S, Chidangil S, Bankapur A. Optical Trapping and Micro-Raman Spectroscopy of Functional Red Blood Cells Using Vortex Beam for Cell Membrane Studies. Anal Chem 2021; 93:5484-5493. [PMID: 33764040 DOI: 10.1021/acs.analchem.0c05204] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
There has been a long-standing interest in Raman spectroscopic investigation of optically trapped single functional cells. Optical trapping using a Gaussian beam has helped researchers for decades to investigate single cells suspended in a physiological medium. However, complete and sensitive probing of single cells demands further advancements in experimental methods. Herein, we propose optical trapping and simultaneous micro-Raman spectroscopy of red blood cells (RBCs) in an unconventional face-on orientation using an optical vortex beam. Using this novel method, we are successful in comparing the conformational state of hemoglobin (Hb) molecules near the RBC membrane and inside the bulk of the cell. This method enabled us to successfully probe the oxy/deoxy ratio of Hb molecules near the RBC membrane and inside the bulk of the cell. Because of the face-on orientation, the Raman spectra of RBCs acquired using a vortex beam have a significant contribution from membrane components compared to that recorded using the Gaussian beam.
Collapse
Affiliation(s)
- Ghanashyam C
- Department of Atomic and Molecular Physics, Manipal Academy of Higher Education, Manipal 576104, India
| | - Sachin Shetty
- Department of Nuclear Medicine, Manipal College of Health Professions, Manipal Academy of Higher Education, Manipal 576104, India
| | - Sanjay Bharati
- Department of Nuclear Medicine, Manipal College of Health Professions, Manipal Academy of Higher Education, Manipal 576104, India
| | - Santhosh Chidangil
- Department of Atomic and Molecular Physics, Manipal Academy of Higher Education, Manipal 576104, India.,Centre of Excellence for Biophotonics, Manipal Academy of Higher Education, Manipal 576104, India
| | - Aseefhali Bankapur
- Department of Atomic and Molecular Physics, Manipal Academy of Higher Education, Manipal 576104, India.,Centre of Excellence for Biophotonics, Manipal Academy of Higher Education, Manipal 576104, India
| |
Collapse
|
13
|
Chng KZ, Ng YC, Namgung B, Tan JKS, Park S, Tien SL, Leo HL, Kim S. Assessment of transient changes in oxygen diffusion of single red blood cells using a microfluidic analytical platform. Commun Biol 2021; 4:271. [PMID: 33654170 PMCID: PMC7925684 DOI: 10.1038/s42003-021-01793-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2020] [Accepted: 01/26/2021] [Indexed: 02/07/2023] Open
Abstract
Red blood cells (RBCs) capability to deliver oxygen (O2) has been routinely measured by P50. Although this defines the ability of RBCs to carry O2 under equilibrium states, it cannot determine the efficacy of O2 delivery in dynamic blood flow. Here, we developed a microfluidic analytical platform (MAP) that isolates single RBCs for assessing transient changes in their O2 release rate. We found that in vivo (biological) and in vitro (blood storage) aging of RBC could lead to an increase in the O2 release rate, despite a decrease in P50. Rejuvenation of stored RBCs (Day 42), though increased the P50, failed to restore the O2 release rate to basal level (Day 0). The temporal dimension provided at the single-cell level by MAP could shed new insights into the dynamics of O2 delivery in both physiological and pathological conditions.
Collapse
Affiliation(s)
- Kevin Ziyang Chng
- Department of Biomedical Engineering, National University of Singapore, Singapore, Singapore
| | - Yan Cheng Ng
- Department of Biomedical Engineering, National University of Singapore, Singapore, Singapore.,NUS Graduate School for Integrative Sciences and Efngineering, National University of Singapore, Singapore, Singapore
| | - Bumseok Namgung
- Department of Biomedical Engineering, National University of Singapore, Singapore, Singapore
| | - Justin Kok Soon Tan
- Department of Biomedical Engineering, National University of Singapore, Singapore, Singapore
| | - Soyeon Park
- Department of Biomedical Engineering, National University of Singapore, Singapore, Singapore.,Institute for Health Innovation & Technology, National University of Singapore, Singapore, Singapore
| | - Sim Leng Tien
- Department of Hematology, Singapore General Hospital, Singapore, Singapore
| | - Hwa Liang Leo
- Department of Biomedical Engineering, National University of Singapore, Singapore, Singapore.,NUS Graduate School for Integrative Sciences and Efngineering, National University of Singapore, Singapore, Singapore
| | - Sangho Kim
- Department of Biomedical Engineering, National University of Singapore, Singapore, Singapore. .,NUS Graduate School for Integrative Sciences and Efngineering, National University of Singapore, Singapore, Singapore. .,Institute for Health Innovation & Technology, National University of Singapore, Singapore, Singapore.
| |
Collapse
|
14
|
Nguyen HTM, Katta N, Widman JA, Takematsu E, Feng X, Torres-Hurtado SA, Betancourt T, Baker AB, Suggs LJ, Milner TE, Tunnell JW. Laser nanobubbles induce immunogenic cell death in breast cancer. NANOSCALE 2021; 13:3644-3653. [PMID: 33538275 PMCID: PMC8710258 DOI: 10.1039/d0nr06587k] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
Recent advances in immunotherapy have highlighted a need for therapeutics that initiate immunogenic cell death in tumors to stimulate the body's immune response to cancer. This study examines whether laser-generated bubbles surrounding nanoparticles ("nanobubbles") induce an immunogenic response for cancer treatment. A single nanosecond laser pulse at 1064 nm generates micron-sized bubbles surrounding gold nanorods in the cytoplasm of breast cancer cells. Cell death occurred in cells treated with nanorods and irradiated, but not in cells with irradiation treatment alone. Cells treated with nanorods and irradiation had increased damage-associated molecular patterns (DAMPs), including increased expression of chaperone proteins human high mobility group box 1 (HMGB1), adenosine triphosphate (ATP), and heat shock protein 70 (HSP70). This enhanced expression of DAMPs led to the activation of dendritic cells. Overall, this treatment approach is a rapid and highly specific method to eradicate tumor cells with simultaneous immunogenic cell death signaling, showing potential as a combination strategy for immunotherapy.
Collapse
Affiliation(s)
- Hieu T M Nguyen
- Department of Biomedical Engineering, The University of Texas at Austin, TX, USA.
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
15
|
Huang YC, Cheng ML, Tang HY, Huang CY, Chen KM, Wang JS. Eccentric Cycling Training Improves Erythrocyte Antioxidant and Oxygen Releasing Capacity Associated with Enhanced Anaerobic Glycolysis and Intracellular Acidosis. Antioxidants (Basel) 2021; 10:antiox10020285. [PMID: 33668606 PMCID: PMC7918820 DOI: 10.3390/antiox10020285] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2021] [Revised: 02/09/2021] [Accepted: 02/10/2021] [Indexed: 11/20/2022] Open
Abstract
The antioxidant capacity of erythrocytes protects individuals against the harmful effects of oxidative stress. Despite improved hemodynamic efficiency, the effect of eccentric cycling training (ECT) on erythrocyte antioxidative capacity remains unclear. This study investigates how ECT affects erythrocyte antioxidative capacity and metabolism in sedentary males. Thirty-six sedentary healthy males were randomly assigned to either concentric cycling training (CCT, n = 12) or ECT (n = 12) at 60% of the maximal workload for 30 min/day, 5 days/week for 6 weeks or to a control group (n = 12) that did not receive an exercise intervention. A graded exercise test (GXT) was performed before and after the intervention. Erythrocyte metabolic characteristics and O2 release capacity were determined by UPLC-MS and high-resolution respirometry, respectively. An acute GXT depleted Glutathione (GSH), accumulated Glutathione disulfide (GSSG), and elevated the GSSG/GSH ratio, whereas both CCT and ECT attenuated the extent of the elevated GSSG/GSH ratio caused by a GXT. Moreover, the two exercise regimens upregulated glycolysis and increased glucose consumption and lactate production, leading to intracellular acidosis and facilitation of O2 release from erythrocytes. Both CCT and ECT enhance antioxidative capacity against severe exercise-evoked circulatory oxidative stress. Moreover, the two exercise regimens activate erythrocyte glycolysis, resulting in lowered intracellular pH and enhanced O2 released from erythrocytes.
Collapse
Affiliation(s)
- Yu-Chieh Huang
- Department of Physical Therapy, College of Medical and Health Science, Asia University, Taichung 413, Taiwan;
| | - Mei-Ling Cheng
- Metabolomics Core Laboratory, Healthy Aging Research Center, Chang Gung University, Taoyuan 333, Taiwan; (M.-L.C.); (H.-Y.T.)
- Clinical Metabolomics Core Laboratory, Chang Gung Memorial Hospital, Taoyuan 333, Taiwan
- Department of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan 333, Taiwan
| | - Hsiang-Yu Tang
- Metabolomics Core Laboratory, Healthy Aging Research Center, Chang Gung University, Taoyuan 333, Taiwan; (M.-L.C.); (H.-Y.T.)
| | - Chi-Yao Huang
- Healthy Aging Research Center, Graduate Institute of Rehabilitation Science, Medical Collage, Chang Gung University, Taoyuan 333, Taiwan; (C.-Y.H.); (K.-M.C.)
| | - Kuan-Ming Chen
- Healthy Aging Research Center, Graduate Institute of Rehabilitation Science, Medical Collage, Chang Gung University, Taoyuan 333, Taiwan; (C.-Y.H.); (K.-M.C.)
| | - Jong-Shyan Wang
- Healthy Aging Research Center, Graduate Institute of Rehabilitation Science, Medical Collage, Chang Gung University, Taoyuan 333, Taiwan; (C.-Y.H.); (K.-M.C.)
- Heart Failure Center, Department of Physical Medicine and Rehabilitation, Keelung Chang Gung Memorial Hospital, Keelung 204, Taiwan
- Research Center for Chinese Herbal Medicine, College of Human Ecology, Chang Gung University of Science and Technology, Taoyuan 333, Taiwan
- Correspondence: ; Tel.: +886-3-2118800 (ext. 5748); Fax: +886+886-3-2118700
| |
Collapse
|
16
|
Shah N, Zhou L. Regulation of Ion Channel Function by Gas Molecules. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2021; 1349:139-164. [DOI: 10.1007/978-981-16-4254-8_8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
17
|
Al-Samir S, Itel F, Hegermann J, Gros G, Tsiavaliaris G, Endeward V. O 2 permeability of lipid bilayers is low, but increases with membrane cholesterol. Cell Mol Life Sci 2021; 78:7649-7662. [PMID: 34694438 PMCID: PMC8629883 DOI: 10.1007/s00018-021-03974-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2021] [Revised: 09/06/2021] [Accepted: 10/12/2021] [Indexed: 11/18/2022]
Abstract
Oxygen on its transport route from lung to tissue mitochondria has to cross several cell membranes. The permeability value of membranes for O2 (PO2), although of fundamental importance, is controversial. Previous studies by mostly indirect methods diverge between 0.6 and 125 cm/s. Here, we use a most direct approach by observing transmembrane O2 fluxes out of 100 nm liposomes at defined transmembrane O2 gradients in a stopped-flow system. Due to the small size of the liposomes intra- as well as extraliposomal diffusion processes do not affect the overall kinetics of the O2 release process. We find, for cholesterol-free liposomes, the unexpectedly low PO2 value of 0.03 cm/s at 35 °C. This PO2 would present a serious obstacle to O2 entering or leaving the erythrocyte. Cholesterol turns out to be a novel major modifier of PO2, able to increase PO2 by an order of magnitude. With a membrane cholesterol of 45 mol% as it occurs in erythrocytes, PO2 rises to 0.2 cm/s at 35 °C. This PO2 is just sufficient to ensure complete O2 loading during passage of erythrocytes through the lung's capillary bed under the conditions of rest as well as maximal exercise.
Collapse
Affiliation(s)
- Samer Al-Samir
- AG Vegetative Physiologie 4220, Zentrum Physiologie, Medizinische Hochschule Hannover, 30625, Hannover, Germany
| | - Fabian Itel
- Empa, Swiss Federal Laboratories for Materials Science and Technology, Lerchenfeldstr. 5, CH-9014, St. Gallen, Switzerland
| | - Jan Hegermann
- Abteilung Funktionelle und Angewandte Anatomie, Elektronenmikroskopie 8840, Medizinische Hochschule Hannover, 30625, Hannover, Germany
| | - Gerolf Gros
- AG Vegetative Physiologie 4220, Zentrum Physiologie, Medizinische Hochschule Hannover, 30625, Hannover, Germany.
| | - Georgios Tsiavaliaris
- Abteilung Biophysikalische Chemie 4350, Medizinische Hochschule Hannover, 30625, Hannover, Germany
| | - Volker Endeward
- AG Vegetative Physiologie 4220, Zentrum Physiologie, Medizinische Hochschule Hannover, 30625, Hannover, Germany
| |
Collapse
|
18
|
Pias SC. How does oxygen diffuse from capillaries to tissue mitochondria? Barriers and pathways. J Physiol 2020; 599:1769-1782. [PMID: 33215707 DOI: 10.1113/jp278815] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2020] [Accepted: 11/11/2020] [Indexed: 12/17/2022] Open
Abstract
Timely delivery of oxygen (O2 ) to tissue mitochondria is so essential that elaborate circulatory systems have evolved to minimize diffusion distances within tissue. Yet, knowledge is surprisingly limited regarding the diffusion pathway between blood capillaries and tissue mitochondria. An established and growing body of work examines the influence cellular and extracellular structures may have on subcellular oxygen availability. This brief review discusses the physiological and pathophysiological significance of oxygen availability, highlights recent computer modelling studies of transport at the cell-membrane level, and considers alternative diffusion pathways within tissue. Experimental and computer modelling studies suggest that oxygen diffusion may be accelerated by cellular lipids, relative to cytosolic and interstitial fluids. Such acceleration, or 'channelling', would occur due to greatly enhanced oxygen solubility in lipids, especially near the midplane of lipid bilayers. Rapid long-range movement would be promoted by anisotropically enhanced lateral diffusion of oxygen along the midplane and by junctions holding lipid structures in close proximity to one another throughout the tissue. Clarifying the biophysical mechanism of oxygen transport within tissue will shed light on limitations and opportunities in tumour radiotherapy and tissue engineering.
Collapse
Affiliation(s)
- Sally C Pias
- Department of Chemistry, New Mexico Institute of Mining and Technology (New Mexico Tech), Socorro, NM, USA
| |
Collapse
|
19
|
Park KC, Donovan K, McKechnie S, Ramamurthy N, Klenerman P, Swietach P. Single-cell oxygen saturation imaging shows that gas exchange by red blood cells is not impaired in COVID-19 patients. Br J Haematol 2020; 190:e229-e232. [PMID: 32678950 PMCID: PMC7405117 DOI: 10.1111/bjh.17025] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Kyung Chan Park
- Department of Physiology, Anatomy & GeneticsUniversity of OxfordOxfordUK
| | - Killian Donovan
- Adult Intensive Care UnitJohn Radcliffe HospitalOxford University Hospitals NHS Foundation TrustOxfordUK
| | - Stuart McKechnie
- Adult Intensive Care UnitJohn Radcliffe HospitalOxford University Hospitals NHS Foundation TrustOxfordUK
| | - Narayan Ramamurthy
- Peter Medawar Building for Pathogen ResearchUniversity of OxfordOxfordUK
| | - Paul Klenerman
- Peter Medawar Building for Pathogen ResearchUniversity of OxfordOxfordUK
| | - Pawel Swietach
- Department of Physiology, Anatomy & GeneticsUniversity of OxfordOxfordUK
| |
Collapse
|