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Fantini DA, Yang G, Khanna A, Subramanian D, Phillippi JA, Huang NF. Overcoming big bottlenecks in vascular regeneration. Commun Biol 2024; 7:876. [PMID: 39020071 PMCID: PMC11255241 DOI: 10.1038/s42003-024-06567-x] [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: 12/04/2023] [Accepted: 07/05/2024] [Indexed: 07/19/2024] Open
Abstract
Bioengineering and regenerative medicine strategies are promising for the treatment of vascular diseases. However, current limitations inhibit the ability of these approaches to be translated to clinical practice. Here we summarize some of the big bottlenecks that inhibit vascular regeneration in the disease applications of aortic aneurysms, stroke, and peripheral artery disease. We also describe the bottlenecks preventing three-dimensional bioprinting of vascular networks for tissue engineering applications. Finally, we describe emerging technologies and opportunities to overcome these challenges to advance vascular regeneration.
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Affiliation(s)
- Dalia A Fantini
- Department of Bioengineering, Swanson School of Engineering, University of Pittsburgh, Pittsburgh, PA, USA
| | - Guang Yang
- Department of Cardiothoracic Surgery, Stanford University, Stanford, CA, USA
- Epicrispr Biotechnologies, Inc, South San Francisco, CA, USA
| | | | - Divya Subramanian
- Department of Bioengineering, University of Texas at Dallas, Richardson, TX, USA
| | - Julie A Phillippi
- Department of Bioengineering, Swanson School of Engineering, University of Pittsburgh, Pittsburgh, PA, USA.
- Department of Cardiothoracic Surgery, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA.
- McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, PA, USA.
| | - Ngan F Huang
- Department of Cardiothoracic Surgery, Stanford University, Stanford, CA, USA.
- Stanford Cardiovascular Institute, Stanford, CA, USA.
- Department of Chemical Engineering, Stanford University, Stanford, CA, USA.
- Veterans Affairs Palo Alto Health Care System, Palo Alto, CA, USA.
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Laird M, Ku JC, Raiten J, Sriram S, Moore M, Li Y. Mitochondrial metabolism regulation and epigenetics in hypoxia. Front Physiol 2024; 15:1393232. [PMID: 38915781 PMCID: PMC11194441 DOI: 10.3389/fphys.2024.1393232] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2024] [Accepted: 05/13/2024] [Indexed: 06/26/2024] Open
Abstract
The complex and dynamic interaction between cellular energy control and gene expression modulation is shown by the intersection between mitochondrial metabolism and epigenetics in hypoxic environments. Poor oxygen delivery to tissues, or hypoxia, is a basic physiological stressor that sets off a series of reactions in cells to adapt and endure oxygen-starved environments. Often called the "powerhouse of the cell," mitochondria are essential to cellular metabolism, especially regarding producing energy through oxidative phosphorylation. The cellular response to hypoxia entails a change in mitochondrial metabolism to improve survival, including epigenetic modifications that control gene expression without altering the underlying genome. By altering the expression of genes involved in angiogenesis, cell survival, and metabolism, these epigenetic modifications help cells adapt to hypoxia. The sophisticated interplay between mitochondrial metabolism and epigenetics in hypoxia is highlighted by several important points, which have been summarized in the current article. Deciphering the relationship between mitochondrial metabolism and epigenetics during hypoxia is essential to understanding the molecular processes that regulate cellular adaptation to reduced oxygen concentrations.
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Affiliation(s)
- Madison Laird
- Western Michigan University Homer Stryker School of Medicine, Kalamazoo, MI, United States
| | - Jennifer C. Ku
- Western Michigan University Homer Stryker School of Medicine, Kalamazoo, MI, United States
| | - Jacob Raiten
- Western Michigan University Homer Stryker School of Medicine, Kalamazoo, MI, United States
| | - Sashwat Sriram
- Western Michigan University Homer Stryker School of Medicine, Kalamazoo, MI, United States
| | - Megan Moore
- Western Michigan University Homer Stryker School of Medicine, Kalamazoo, MI, United States
| | - Yong Li
- Department of Orthopaedic Surgery, Biomedical Engineering, Western Michigan University Homer Stryker School of Medicine, Kalamazoo, MI, United States
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Tarvainen S, Wirth G, Juusola G, Hautero O, Kalliokoski K, Sjöros T, Nikulainen V, Taavitsainen J, Hytönen J, Frimodig C, Happonen K, Selander T, Laitinen T, Hakovirta HH, Knuuti J, Laham-Karam N, Hartikainen J, Mäkinen K, Ylä-Herttuala S, Korpisalo P. Critical limb-threatening ischaemia and microvascular transformation: clinical implications. Eur Heart J 2024; 45:255-264. [PMID: 37634134 PMCID: PMC10821383 DOI: 10.1093/eurheartj/ehad562] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Revised: 08/08/2023] [Accepted: 08/21/2023] [Indexed: 08/29/2023] Open
Abstract
BACKGROUND AND AIMS Clinical management of critical limb-threatening ischaemia (CLTI) is focused on prevention and treatment of atherosclerotic arterial occlusions. The role of microvascular pathology in disease progression is still largely unspecified and more importantly not utilized for treatment. The aim of this explorative study was to characterize the role of the microvasculature in CLTI pathology. METHODS Clinical high-resolution imaging of CLTI patients (n = 50) and muscle samples from amputated CLTI limbs (n = 40) were used to describe microvascular pathology of CLTI at the level of resting muscle blood flow and microvascular structure, respectively. Furthermore, a chronic, low arterial driving pressure-simulating ischaemia model in rabbits (n = 24) was used together with adenoviral vascular endothelial growth factor A gene transfers to study the effect of microvascular alterations on muscle outcome. RESULTS Resting microvascular blood flow was not depleted but displayed decreased capillary transit time (P < .01) in CLTI muscles. Critical limb-threatening ischaemia muscle microvasculature also exhibited capillary enlargement (P < .001) and further arterialization along worsening of myofibre atrophy and detaching of capillaries from myofibres. Furthermore, CLTI-like capillary transformation was shown to worsen calf muscle force production (P < .05) and tissue outcome (P < .01) under chronic ischaemia in rabbits and in healthy, normal rabbit muscle. CONCLUSIONS These findings depict a progressive, hypoxia-driven transformation of the microvasculature in CLTI muscles, which pathologically alters blood flow dynamics and aggravates tissue damage under low arterial driving pressure. Hypoxia-driven capillary enlargement can be highly important for CLTI outcomes and should therefore be considered in further development of diagnostics and treatment of CLTI.
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Affiliation(s)
- Santeri Tarvainen
- Heart Center, Kuopio University Hospital, Puijonlaaksontie 2, 70210 Kuopio, Finland
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio, Finland
| | - Galina Wirth
- Heart Center, Kuopio University Hospital, Puijonlaaksontie 2, 70210 Kuopio, Finland
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio, Finland
| | - Greta Juusola
- Heart Center, Kuopio University Hospital, Puijonlaaksontie 2, 70210 Kuopio, Finland
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio, Finland
| | - Olli Hautero
- Turku University Hospital, Turku, Finland
- Vaasa Central Hospital, Vaasa, Finland
| | - Kari Kalliokoski
- Turku University Hospital, Turku, Finland
- Turku PET Centre, Turku, Finland
- University of Turku, Turku, Finland
- Åbo Akademi University, Turku, Finland
| | - Tanja Sjöros
- Turku University Hospital, Turku, Finland
- Turku PET Centre, Turku, Finland
- University of Turku, Turku, Finland
- Åbo Akademi University, Turku, Finland
| | | | - Jouni Taavitsainen
- Heart Center, Kuopio University Hospital, Puijonlaaksontie 2, 70210 Kuopio, Finland
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio, Finland
| | - Jarkko Hytönen
- Heart Center, Kuopio University Hospital, Puijonlaaksontie 2, 70210 Kuopio, Finland
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio, Finland
| | - Crister Frimodig
- Heart Center, Kuopio University Hospital, Puijonlaaksontie 2, 70210 Kuopio, Finland
| | - Krista Happonen
- Heart Center, Kuopio University Hospital, Puijonlaaksontie 2, 70210 Kuopio, Finland
| | - Tuomas Selander
- Research Services, Kuopio University Hospital, Puijonlaaksontie 2, 70210 Kuopio, Finland
| | - Tomi Laitinen
- Imaging Center, Kuopio University Hospital, Puijonlaaksontie 2, 70210 Kuopio, Finland
| | - Harri H Hakovirta
- Turku University Hospital, Turku, Finland
- University of Turku, Turku, Finland
- Satasairaala, Pori, Finland
| | - Juhani Knuuti
- Turku University Hospital, Turku, Finland
- Turku PET Centre, Turku, Finland
- University of Turku, Turku, Finland
- Åbo Akademi University, Turku, Finland
| | - Nihay Laham-Karam
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio, Finland
| | - Juha Hartikainen
- Heart Center, Kuopio University Hospital, Puijonlaaksontie 2, 70210 Kuopio, Finland
| | - Kimmo Mäkinen
- Heart Center, Kuopio University Hospital, Puijonlaaksontie 2, 70210 Kuopio, Finland
| | - Seppo Ylä-Herttuala
- Heart Center, Kuopio University Hospital, Puijonlaaksontie 2, 70210 Kuopio, Finland
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio, Finland
| | - Petra Korpisalo
- Heart Center, Kuopio University Hospital, Puijonlaaksontie 2, 70210 Kuopio, Finland
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio, Finland
- Turku University Hospital, Turku, Finland
- Turku PET Centre, Turku, Finland
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Dargent A, Dumargne H, Labruyère M, Brezillon S, Brassart-Pasco S, Blot M, Charles PE, Fournel I, Quenot JP, Jacquier M. Role of the interstitium during septic shock: a key to the understanding of fluid dynamics? J Intensive Care 2023; 11:44. [PMID: 37817235 PMCID: PMC10565984 DOI: 10.1186/s40560-023-00694-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2023] [Accepted: 09/29/2023] [Indexed: 10/12/2023] Open
Abstract
BACKGROUND While not traditionally included in the conceptual understanding of circulation, the interstitium plays a critical role in maintaining fluid homeostasis. Fluid balance regulation is a critical aspect of septic shock, with a well-known association between fluid balance and outcome. The regulation of transcapillary flow is the first key to understand fluid homeostasis during sepsis. MAIN TEXT Capillary permeability is increased during sepsis, and was classically considered to be necessary and sufficient to explain the increase of capillary filtration during inflammation. However, on the other side of the endothelial wall, the interstitium may play an even greater role to drive capillary leak. Indeed, the interstitial extracellular matrix forms a complex gel-like structure embedded in a collagen skeleton, and has the ability to directly attract intravascular fluid by decreasing its hydrostatic pressure. Thus, interstitium is not a mere passive reservoir, as was long thought, but is probably major determinant of fluid balance regulation during sepsis. Up to this date though, the role of the interstitium during sepsis and septic shock has been largely overlooked. A comprehensive vision of the interstitium may enlight our understanding of septic shock pathophysiology. Overall, we have identified five potential intersections between septic shock pathophysiology and the interstitium: 1. increase of oedema formation, interacting with organ function and metabolites diffusion; 2. interstitial pressure regulation, increasing transcapillary flow; 3. alteration of the extracellular matrix; 4. interstitial secretion of inflammatory mediators; 5. decrease of lymphatic outflow. CONCLUSIONS We aimed at reviewing the literature and summarizing the current knowledge along these specific axes, as well as methodological aspects related to interstitium exploration.
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Affiliation(s)
- Auguste Dargent
- Service d'Anesthésie Médecine Intensive-Réanimation, Hospices Civils de Lyon, Hôpital Lyon Sud, 165 Chemin du Grand Revoyet, Pierre-Bénite, 69495, Lyon, France.
- APCSe VetAgro Sup UPSP 2016.A101, 1 Avenue Bourgelat, 69280, Marcy l'Etoile, France.
| | - Hugo Dumargne
- Service d'Anesthésie Médecine Intensive-Réanimation, Hospices Civils de Lyon, Hôpital Lyon Sud, 165 Chemin du Grand Revoyet, Pierre-Bénite, 69495, Lyon, France
| | - Marie Labruyère
- Médecine Intensive et Réanimation, CHU François Mitterrand, 14 Rue Paul Gaffarel, 21000, Dijon, France
| | | | | | - Mathieu Blot
- Maladies Infectieuses et Tropicales, CHU François Mitterrand, 14 Rue Paul Gaffarel, 21000, Dijon, France
- Lipness Team, INSERM LNC-UMR1231 et LabEx LipSTIC, Université de Bourgogne, 7 Bd Jeanne d'Arc, 21000, Dijon, France
| | - Pierre-Emmanuel Charles
- Médecine Intensive et Réanimation, CHU François Mitterrand, 14 Rue Paul Gaffarel, 21000, Dijon, France
- Lipness Team, INSERM LNC-UMR1231 et LabEx LipSTIC, Université de Bourgogne, 7 Bd Jeanne d'Arc, 21000, Dijon, France
| | - Isabelle Fournel
- Module Épidémiologie Clinique, Inserm, CHU Dijon, Bourgogne, Université de Bourgogne, CIC1432, 14 Rue Paul Gaffarel, 21000, Dijon, France
| | - Jean-Pierre Quenot
- Médecine Intensive et Réanimation, CHU François Mitterrand, 14 Rue Paul Gaffarel, 21000, Dijon, France
- Lipness Team, INSERM LNC-UMR1231 et LabEx LipSTIC, Université de Bourgogne, 7 Bd Jeanne d'Arc, 21000, Dijon, France
- Module Épidémiologie Clinique, Inserm, CHU Dijon, Bourgogne, Université de Bourgogne, CIC1432, 14 Rue Paul Gaffarel, 21000, Dijon, France
| | - Marine Jacquier
- Médecine Intensive et Réanimation, CHU François Mitterrand, 14 Rue Paul Gaffarel, 21000, Dijon, France
- Lipness Team, INSERM LNC-UMR1231 et LabEx LipSTIC, Université de Bourgogne, 7 Bd Jeanne d'Arc, 21000, Dijon, France
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Friberg M, Woeller K, Iberi V, Mancheno PP, Riedeman J, Bohman L, Davis CC. Development of in vitro methods to model the impact of vaginal lactobacilli on Staphylococcus aureus biofilm formation on menstrual cups as well as validation of recommended cleaning directions. FRONTIERS IN REPRODUCTIVE HEALTH 2023; 5:1162746. [PMID: 37671283 PMCID: PMC10475951 DOI: 10.3389/frph.2023.1162746] [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: 02/09/2023] [Accepted: 07/25/2023] [Indexed: 09/07/2023] Open
Abstract
Introduction Menstrual cups (MC) are a reusable feminine hygiene product. A recent publication suggested that Staphylococcus aureus (S. aureus) biofilms can form on MCs which may lead to increased risk of menstrual Toxic Shock Syndrome (mTSS). Additionally, there is concern that buildup of residual menses may contribute to microbial growth and biofilm formation further increasing mTSS risk. Quantitative and qualitative analysis of in vitro tests were utilized to determine if S. aureus biofilm could form on MC in the presence of the keystone species Lactobacillus after 12 h of incubation. The methodology was based on a modification of an anaerobic in vitro method that harnesses the keystone species hypothesis by including a representative of vaginal lactic acid bacteria. Methods MCs were incubated anaerobically for 12 h in Vaginal Defined Media (VDM) with the two morphologically distinct bacteria, Lactobacillus gasseri (L. gasseri) and S. aureus. Colony Forming Units (CFU) for each organism from the VDM broth and sonicated MC were estimated. In addition, a separate experiment was conducted where S. aureus was grown for 12 h in the absence of L. gasseri. Qualitative analysis for biofilm formation utilized micro-CT (µ-CT) and cryogenic scanning electron microscopy (Cryo-SEM). Results Samples collected from the media control had expected growth of both organisms after 12 h of incubation. Samples collected from VDM broth were similar to media control at the end of the 12-h study. Total S. aureus cell density on MC following sonication/rinsing was minimal. Results when using a monoculture of S. aureus demonstrated that there was a significant growth of the organism in the media control and broth as well as the sonicated cups indicating that the presence of L. gasseri was important for controlling growth and adherence of S. aureus. Few rod-shaped bacteria (L. gasseri) and cocci (S. aureus) could be identified on the MCs when grown in a dual species culture inoculum and no biofilm was noted via µ-CT and cryo-SEM. Additionally, efforts to model and understand the validity of the current labeled recommendations for MC cleaning in-between uses are supported. Discussion The data support continued safe use of the Tampax® cup when used and maintained as recommended.
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Affiliation(s)
- Maria Friberg
- Baby, Feminine and Family Care Microbiology, The Procter & Gamble Company, Mason, OH, United States
| | - Kara Woeller
- Baby, Feminine and Family Care, Global Product Stewardship, The Procter & Gamble Company, Cincinnati, OH, United States
| | - Vighter Iberi
- Corporate Functions Analytical, The Procter & Gamble Company, Mason, OH, United States
| | | | - James Riedeman
- Baby, Family and Feminine Care Analytical Chemistry, The Procter & Gamble Company, Cincinnati, OH, United States
| | - Lisa Bohman
- Data Modeling and Sciences, The Procter & Gamble Company, Mason, OH, United States
| | - Catherine C. Davis
- Department of Medical Microbiology and Immunology, School of Medicine, Creighton University, Omaha, NE, United States
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Wang H, Falcoz S, Morales J, Berteau JP. Investigating bone resorption in Atlantic herring fish intermuscular bones with solid-state NMR. Phys Chem Chem Phys 2023; 25:9336-9348. [PMID: 36920434 DOI: 10.1039/d2cp03023c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/08/2023]
Abstract
Bones are connective tissues mainly made of collagen proteins with calcium phosphate deposits. They undergo constant remodeling, including destroying existing bones tissues (known as bone resorption) and rebuilding new ones. Bone remodeling has been well-described in mammals, but it is not the case in fish. Here, we focused on the mobile phase of the bone vascular system by carefully preserving moisture in adult Atlantic herring intermuscular bones. We detected pore water with high ionic strength and soluble degraded peptides whose 1H-transverse relaxation times, T2s, exceed 15 milliseconds. With favorable T2s, we incorporated a solution state spinlock scheme into the INEPT techniques to unequivocally demonstrate collagen degradation. In addition, we detected a substantial amount of inorganic phosphate in solution with 31P-NMR in the considerable background of solid hydroxyapatite calcium phosphate by saturation recovery experiment. It is consistent with the idea that bone resorption degrades bone collagen and releases calcium ions and phosphate ions in the pore water with increased ionic strength. Our report is the first to probe the resorption process in the heterogenous bone microstructure with a rigorous characterization of 1H and 13C relaxation behavior and direct assignments. In addition, we contribute to the fish bones literature by investigating fish bone remodeling using NMR for the first time.
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Affiliation(s)
- Hsin Wang
- Department of Chemistry and Biochemistry, The City College of New York, 85 St. Nicholas Terrace, New York, NY 10031, USA.
| | - Steve Falcoz
- Department of Physical Therapy, The College of Staten Island, 2800 Victory Blvd, Staten Island, NY 10314, USA
| | - Jorge Morales
- Department of Chemistry and Biochemistry, The City College of New York, 85 St. Nicholas Terrace, New York, NY 10031, USA.
| | - Jean-Philippe Berteau
- Department of Physical Therapy, The College of Staten Island, 2800 Victory Blvd, Staten Island, NY 10314, USA.,New York Centre for Biomedical Engineering, City University of New York - City College of New York, New York 10031, USA.,Nanosciences Initiative, City University of New York - Advanced Science Research Center, New York 10031, USA
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7
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Dotson RJ, McClenahan E, Pias SC. Updated Evaluation of Cholesterol's Influence on Membrane Oxygen Permeability. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2021; 1269:23-30. [PMID: 33966190 DOI: 10.1007/978-3-030-48238-1_4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
There is a surprising gap in knowledge regarding the mechanism of oxygen (O2) diffusional delivery at the level of tissues and cells. Yet, the effectiveness of tumor radiotherapy, the success of tissue engineering, and healthy metabolism all require ample intracellular oxygen. Tissue-level diffusion takes place in a complex and crowded macromolecular environment. Cholesterol-rich cellular membranes have been thought to reduce oxygen flux. Here, we use atomistic molecular dynamics simulations to update prior estimates of bilayer permeability and related parameters for 1-palmitoyl,2-oleoylphosphatidylcholine (POPC) and POPC/cholesterol bilayers, using a modified O2 model with improved membrane-water partitioning behavior. This work estimates an oxygen permeability coefficient of 15 ± 1 cm/s for POPC and 11.5 ± 0.4 cm/s for POPC/cholesterol (1:1 molecular ratio) at 37 °C. The permeability of POPC is found to be ~1/3 that of a water layer of similar thickness, and the permeability of POPC/cholesterol is estimated to be 20-30% below that of POPC. Void pathway visualization and free energy data support channeling of oxygen toward the center of cholesterol-incorporating membranes, while partition coefficient data suggest reduced membrane solubility of oxygen due to cholesterol. Further study is needed to understand whether diffusion pathway changes due to cholesterol and other molecular compositional factors influence oxygen availability within tissue.
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Affiliation(s)
- Rachel J Dotson
- Department of Chemistry, New Mexico Institute of Mining and Technology (New Mexico Tech), Socorro, NM, USA
| | - Emily McClenahan
- Department of Chemistry, New Mexico Institute of Mining and Technology (New Mexico Tech), Socorro, NM, USA
| | - Sally C Pias
- Department of Chemistry, New Mexico Institute of Mining and Technology (New Mexico Tech), Socorro, NM, USA.
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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.
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Affiliation(s)
- Sally C Pias
- Department of Chemistry, New Mexico Institute of Mining and Technology (New Mexico Tech), Socorro, NM, USA
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Swartz HM, Flood AB, Schaner PE, Halpern H, Williams BB, Pogue BW, Gallez B, Vaupel P. How best to interpret measures of levels of oxygen in tissues to make them effective clinical tools for care of patients with cancer and other oxygen-dependent pathologies. Physiol Rep 2020; 8:e14541. [PMID: 32786045 PMCID: PMC7422807 DOI: 10.14814/phy2.14541] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2020] [Revised: 07/01/2020] [Accepted: 07/01/2020] [Indexed: 02/07/2023] Open
Abstract
It is well understood that the level of molecular oxygen (O2 ) in tissue is a very important factor impacting both physiology and pathological processes as well as responsiveness to some treatments. Data on O2 in tissue could be effectively utilized to enhance precision medicine. However, the nature of the data that can be obtained using existing clinically applicable techniques is often misunderstood, and this can confound the effective use of the information. Attempts to make clinical measurements of O2 in tissues will inevitably provide data that are aggregated over time and space and therefore will not fully represent the inherent heterogeneity of O2 in tissues. Additionally, the nature of existing techniques to measure O2 may result in uneven sampling of the volume of interest and therefore may not provide accurate information on the "average" O2 in the measured volume. By recognizing the potential limitations of the O2 measurements, one can focus on the important and useful information that can be obtained from these techniques. The most valuable clinical characterizations of oxygen are likely to be derived from a series of measurements that provide data about factors that can change levels of O2 , which then can be exploited both diagnostically and therapeutically. The clinical utility of such data ultimately needs to be verified by careful studies of outcomes related to the measured changes in levels of O2 .
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Affiliation(s)
- Harold M Swartz
- Department of Radiology, Dartmouth Medical School, Hanover, NH, USA
- Department of Medicine, Section of Radiation Oncology, Dartmouth-Hitchcock Medical Center, Lebanon, NH, USA
- Thayer School of Engineering, Dartmouth College, Hanover, NH, USA
| | - Ann Barry Flood
- Department of Radiology, Dartmouth Medical School, Hanover, NH, USA
| | - Philip E Schaner
- Department of Medicine, Section of Radiation Oncology, Dartmouth-Hitchcock Medical Center, Lebanon, NH, USA
| | - Howard Halpern
- Department Radiation and Cellular Oncology, University of Chicago, Chicago, IL, USA
| | - Benjamin B Williams
- Department of Radiology, Dartmouth Medical School, Hanover, NH, USA
- Department of Medicine, Section of Radiation Oncology, Dartmouth-Hitchcock Medical Center, Lebanon, NH, USA
- Thayer School of Engineering, Dartmouth College, Hanover, NH, USA
| | - Brian W Pogue
- Thayer School of Engineering, Dartmouth College, Hanover, NH, USA
- Department of Surgery, Dartmouth-Hitchcock Medical Center, Lebanon, NH, USA
| | - Bernard Gallez
- Louvain Drug Research Institute, Université catholique de Louvain, Brussels, Belgium
| | - Peter Vaupel
- Department Radiation Oncology, University Medical Center, University of Freiburg, Freiburg, Germany
- German Cancer Center Consortium (DKTK) Partner Site Freiburg, German Cancer Research Center (DKFZ), Heidelberg, Germany
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