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Hernández-Espinosa LC, Hernández-Muñoz R. Blood flow-bearing physical forces, endothelial glycocalyx, and liver enzyme mobilization: A hypothesis. J Gen Physiol 2024; 156:e202313462. [PMID: 38231124 PMCID: PMC10794122 DOI: 10.1085/jgp.202313462] [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: 08/02/2023] [Revised: 10/13/2023] [Accepted: 12/18/2023] [Indexed: 01/18/2024] Open
Abstract
Numerous elements involved in shear stress-induced signaling have been identified, recognizing their functions as mechanotransducing ion channels situated at cellular membranes. This form of mechanical signaling relies on transmembrane proteins and cytoplasmic proteins that restructure the cytoskeleton, contributing to mechanotransduction cascades. Notably, blood flow generates mechanical forces that significantly impact the structure and remodeling of blood vessels. The primary regulation of blood vessel responses occurs through hemodynamic forces acting on the endothelium. These mechanical events intricately govern endothelial biophysical, biochemical, and genetic responses. Endothelial cells, positioned on the intimal surface of blood vessels, have the capability to express components of the glycocalyx. This endothelial structure emerges as a pivotal factor in mechanotransduction and the regulation of vascular tone. The endothelial glycocalyx assumes diverse roles in both health and disease. Our findings propose a connection between the release of specific enzymes from the rat liver and variations in the hepatic blood flow/mass ratio. Importantly, this phenomenon is not correlated with liver necrosis. Consequently, this review serves as an exploration of the potential involvement of membrane proteins in a hypothetical mechanotransducing phenomenon capable of controlling the release of liver enzymes.
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Affiliation(s)
- Lorena Carmina Hernández-Espinosa
- Department of Cell Biology and Development, Institute of Cellular Physiology, Universidad Nacional Autónoma de México (UNAM), Mexico City, Mexico
| | - Rolando Hernández-Muñoz
- Department of Cell Biology and Development, Institute of Cellular Physiology, Universidad Nacional Autónoma de México (UNAM), Mexico City, Mexico
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2
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Thota LNR, Lopez Rosales JE, Placencia I, Zemskov EA, Tonino P, Michael AN, Black SM, Chignalia AZ. The Pulmonary Endothelial Glycocalyx Modifications in Glypican 1 Knockout Mice Do Not Affect Lung Endothelial Function in Physiological Conditions. Int J Mol Sci 2023; 24:14568. [PMID: 37834029 PMCID: PMC10573009 DOI: 10.3390/ijms241914568] [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: 07/31/2023] [Revised: 09/11/2023] [Accepted: 09/20/2023] [Indexed: 10/15/2023] Open
Abstract
The endothelial glycocalyx is a dynamic signaling surface layer that is involved in the maintenance of cellular homeostasis. The glycocalyx has a very diverse composition, with glycoproteins, proteoglycans, and glycosaminoglycans interacting with each other to form a mesh-like structure. Due to its highly interactive nature, little is known about the relative contribution of each glycocalyx constituent to its overall function. Investigating the individual roles of the glycocalyx components to cellular functions and system physiology is challenging, as the genetic manipulation of animals that target specific glycocalyx components may result in the development of a modified glycocalyx. Thus, it is crucial that genetically modified animal models for glycocalyx components are characterized and validated before the development of mechanistic studies. Among the glycocalyx components, glypican 1, which acts through eNOS-dependent mechanisms, has recently emerged as a player in cardiovascular diseases. Whether glypican 1 regulates eNOS in physiological conditions is unclear. Herein, we assessed how the deletion of glypican 1 affects the development of the pulmonary endothelial glycocalyx and the impact on eNOS activity and endothelial function. Male and female 5-9-week-old wild-type and glypican 1 knockout mice were used. Transmission electron microscopy, immunofluorescence, and immunoblotting assessed the glycocalyx structure and composition. eNOS activation and content were assessed by immunoblotting; nitric oxide production was assessed by the Griess reaction. The pulmonary phenotype was evaluated by histological signs of lung injury, in vivo measurement of lung mechanics, and pulmonary ventilation. Glypican 1 knockout mice showed a modified glycocalyx with increased glycocalyx thickness and heparan sulfate content and decreased expression of syndecan 4. These alterations were associated with decreased phosphorylation of eNOS at S1177. The production of nitric oxides was not affected by the deletion of glypican 1, and the endothelial barrier was preserved in glypican 1 knockout mice. Pulmonary compliance was decreased, and pulmonary ventilation was unaltered in glypican 1 knockout mice. Collectively, these data indicate that the deletion of glypican 1 may result in the modification of the glycocalyx without affecting basal lung endothelial function, validating this mouse model as a tool for mechanistic studies that investigate the role of glypican 1 in lung endothelial function.
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Affiliation(s)
- Lakshmi N. R. Thota
- Department of Anesthesiology, College of Medicine-Tucson, The University of Arizona, Tucson, AZ 85724, USA (J.E.L.R.)
| | - Joaquin E. Lopez Rosales
- Department of Anesthesiology, College of Medicine-Tucson, The University of Arizona, Tucson, AZ 85724, USA (J.E.L.R.)
| | - Ivan Placencia
- Department of Anesthesiology, College of Medicine-Tucson, The University of Arizona, Tucson, AZ 85724, USA (J.E.L.R.)
| | - Evgeny A. Zemskov
- Center for Translational Science, Florida International University, Port St. Lucie, FL 34987, USA
- Department of Cellular Biology & Pharmacology, Howard Wertheim College of Medicine, Florida International University, Miami, FL 33199, USA
| | - Paola Tonino
- Research, Innovation & Impact Cores Facilities, Imaging Cores-Electron, Life Sciences North, The University of Arizona, Tucson, AZ 85719, USA;
| | - Ashley N. Michael
- Asthma and Airway Disease Research Center, The University of Arizona, Tucson, AZ 85724, USA
| | - Stephen M. Black
- Center for Translational Science, Florida International University, Port St. Lucie, FL 34987, USA
- Department of Cellular Biology & Pharmacology, Howard Wertheim College of Medicine, Florida International University, Miami, FL 33199, USA
- Department of Environmental Health Sciences, Robert Stempel College of Public Health and Social Work, Florida International University, Miami, FL 33174, USA
| | - Andreia Z. Chignalia
- Department of Anesthesiology, College of Medicine-Tucson, The University of Arizona, Tucson, AZ 85724, USA (J.E.L.R.)
- Department of Physiology, College of Medicine-Tucson, The University of Arizona, Tucson, AZ 85724, USA
- Sarver Heart Center, The University of Arizona, Tucson, AZ 85724, USA
- Department of Pharmacology and Toxicology, College of Pharmacy, The University of Arizona, Tucson, AZ 85721, USA
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3
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Kaur G, Harris NR. Endothelial glycocalyx in retina, hyperglycemia, and diabetic retinopathy. Am J Physiol Cell Physiol 2023; 324:C1061-C1077. [PMID: 36939202 PMCID: PMC10125029 DOI: 10.1152/ajpcell.00188.2022] [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: 05/05/2022] [Revised: 02/28/2023] [Accepted: 03/16/2023] [Indexed: 03/21/2023]
Abstract
The endothelial glycocalyx (EG) is a meshlike network present on the apical surface of the endothelium. Membrane-bound proteoglycans, the major backbone molecules of the EG, consist of glycosaminoglycans attached to core proteins. In addition to maintaining the integrity of the endothelial barrier, the EG regulates inflammation and perfusion and acts as a mechanosensor. The loss of the EG can cause endothelial dysfunction and drive the progression of vascular diseases including diabetic retinopathy. Therefore, the EG presents a novel therapeutic target for treatment of vascular complications. In this review article, we provide an overview of the structure and function of the EG in the retina. Our particular focus is on hyperglycemia-induced perturbations in the glycocalyx structure in the retina, potential underlying mechanisms, and clinical trials studying protective treatments against degradation of the EG.
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Affiliation(s)
- Gaganpreet Kaur
- Department of Molecular and Cellular Physiology, Louisiana State University Health Sciences Center-Shreveport, Shreveport, Louisiana, United States
| | - Norman R Harris
- Department of Molecular and Cellular Physiology, Louisiana State University Health Sciences Center-Shreveport, Shreveport, Louisiana, United States
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4
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Mortazavi CM, Hoyt JM, Patel A, Chignalia AZ. The glycocalyx and calcium dynamics in endothelial cells. CURRENT TOPICS IN MEMBRANES 2023; 91:21-41. [PMID: 37080679 DOI: 10.1016/bs.ctm.2023.02.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/22/2023]
Abstract
The endothelial glycocalyx is a dynamic surface layer composed of proteoglycans, glycoproteins, and glycosaminoglycans with a key role in maintaining endothelial cell homeostasis. Its functions include the regulation of endothelial barrier permeability and stability, the transduction of mechanical forces from the vascular lumen to the vessel walls, serving as a binding site to multiple growth factors and vasoactive agents, and mediating the binding of platelets and the migration of leukocytes during an inflammatory response. Many of these processes are associated with changes in intracellular calcium levels that may occur through mechanisms that alter calcium entry in the endothelium or the release of calcium from the endoplasmic reticulum. Whether the endothelial glycocalyx can regulate calcium dynamics in endothelial cells is unresolved. Interestingly, during cardiovascular disease progression, changes in calcium dynamics are observed in association with the degradation of the glycocalyx and with changes in barrier permeability and vascular reactivity. Herein, we aim to provide a summarized overview of what is known regarding the role of the glycocalyx as a regulator of endothelial barrier and vascular reactivity during homeostatic and pathological conditions and to provide a perspective on how such processes may relate to calcium dynamics in endothelial cells, exploring a possible connection between components of the glycocalyx and calcium-sensitive pathways in the endothelium.
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Affiliation(s)
- Cameron M Mortazavi
- Department of Anesthesiology, University of Arizona, College of Medicine, Tucson, AZ, United States
| | - Jillian M Hoyt
- Department of Anesthesiology, University of Arizona, College of Medicine, Tucson, AZ, United States
| | - Aamir Patel
- Department of Anesthesiology, University of Arizona, College of Medicine, Tucson, AZ, United States
| | - Andreia Z Chignalia
- Department of Anesthesiology, University of Arizona, College of Medicine, Tucson, AZ, United States; Department of Physiology, University of Arizona, College of Medicine, Tucson, AZ, United States; Department of Pharmacology & Toxicology, University of Arizona, College of Pharmacy, Tucson, AZ, United States.
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5
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Raredon MSB, Engler AJ, Yuan Y, Greaney AM, Niklason LE. Microvascular fluid flow in ex vivo and engineered lungs. J Appl Physiol (1985) 2021; 131:1444-1459. [PMID: 34554016 PMCID: PMC8616606 DOI: 10.1152/japplphysiol.00286.2020] [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: 04/15/2020] [Revised: 08/23/2021] [Accepted: 09/15/2021] [Indexed: 11/22/2022] Open
Abstract
In recent years, it has become common to experiment with ex vivo perfused lungs for organ transplantation and to attempt regenerative pulmonary engineering using decellularized lung matrices. However, our understanding of the physiology of ex vivo organ perfusion is imperfect; it is not currently well understood how decreasing microvascular barrier affects the perfusion of pulmonary parenchyma. In addition, protocols for lung perfusion and organ culture fluid-handling are far from standardized, with widespread variation on both basic methods and on ideally controlled parameters. To address both of these deficits, a robust, noninvasive, and mechanistic model is needed which is able to predict microvascular resistance and permeability in perfused lungs while providing insight into capillary recruitment. Although validated mathematical models exist for fluid flow in native pulmonary tissue, previous models generally assume minimal intravascular leak from artery to vein and do not assess capillary bed recruitment. Such models are difficult to apply to both ex vivo lung perfusions, in which edema can develop over time and microvessels can become blocked, and to decellularized ex vivo organomimetic cultures, in which microvascular recruitment is variable and arterially perfused fluid enters into the alveolar space. Here, we develop a mathematical model of pulmonary microvascular fluid flow which is applicable in both instances, and we apply our model to data from native, decellularized, and regenerating lungs under ex vivo perfusion. The results provide substantial insight into microvascular pressure-flow mechanics, while producing previously unknown output values for tissue-specific capillary-alveolar hydraulic conductivity, microvascular recruitment, and total organ barrier resistance.NEW & NOTEWORTHY We present a validated model of pulmonary microvascular fluid mechanics and apply this model to study the effects of increased capillary permeability in decellularized and regenerating lungs. We find that decellularization alters microvascular steady-state mechanics and that re-endothelialization partially rescues key biologic parameters. The described model provides powerful insight into intraorgan microvascular dynamics and may be used to guide regenerative engineering experiments. We include all data and derivations necessary to replicate this work.
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Affiliation(s)
- Micha Sam Brickman Raredon
- Department of Biomedical Engineering, Yale University, New Haven, Connecticut
- Vascular Biology and Therapeutics, Yale University, New Haven, Connecticut
- Medical Scientist Training Program, Yale University, New Haven, Connecticut
| | - Alexander J Engler
- Department of Biomedical Engineering, Yale University, New Haven, Connecticut
- Vascular Biology and Therapeutics, Yale University, New Haven, Connecticut
| | - Yifan Yuan
- Vascular Biology and Therapeutics, Yale University, New Haven, Connecticut
- Department of Anesthesiology, Yale University, New Haven, Connecticut
| | - Allison M Greaney
- Department of Biomedical Engineering, Yale University, New Haven, Connecticut
- Vascular Biology and Therapeutics, Yale University, New Haven, Connecticut
| | - Laura E Niklason
- Department of Biomedical Engineering, Yale University, New Haven, Connecticut
- Vascular Biology and Therapeutics, Yale University, New Haven, Connecticut
- Department of Anesthesiology, Yale University, New Haven, Connecticut
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6
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Smart L, Hughes D. The Effects of Resuscitative Fluid Therapy on the Endothelial Surface Layer. Front Vet Sci 2021; 8:661660. [PMID: 34026896 PMCID: PMC8137965 DOI: 10.3389/fvets.2021.661660] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2021] [Accepted: 03/16/2021] [Indexed: 01/20/2023] Open
Abstract
The goal of resuscitative fluid therapy is to rapidly expand circulating blood volume in order to restore tissue perfusion. Although this therapy often serves to improve macrohemodynamic parameters, it can be associated with adverse effects on the microcirculation and endothelium. The endothelial surface layer (ESL) provides a protective barrier over the endothelium and is important for regulating transvascular fluid movement, vasomotor tone, coagulation, and inflammation. Shedding or thinning of the ESL can promote interstitial edema and inflammation and may cause microcirculatory dysfunction. The pathophysiologic perturbations of critical illness and rapid, large-volume fluid therapy both cause shedding or thinning of the ESL. Research suggests that restricting the volume of crystalloid, or “clear” fluid, may preserve some ESL integrity and improve outcome based on animal experimental models and preliminary clinical trials in people. This narrative review critically evaluates the evidence for the detrimental effects of resuscitative fluid therapy on the ESL and provides suggestions for future research directions in this field.
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Affiliation(s)
- Lisa Smart
- School of Veterinary Medicine, College of Science, Health, Engineering and Education, Murdoch University, Murdoch, WA, Australia
| | - Dez Hughes
- Department of Veterinary Clinical Sciences, Faculty of Veterinary and Agricultural Sciences, Melbourne Veterinary School, Werribee, VIC, Australia
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Endothelial Glycocalyx as a Regulator of Fibrotic Processes. Int J Mol Sci 2021; 22:ijms22062996. [PMID: 33804258 PMCID: PMC7999025 DOI: 10.3390/ijms22062996] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Revised: 03/02/2021] [Accepted: 03/11/2021] [Indexed: 12/31/2022] Open
Abstract
The endothelial glycocalyx, the gel layer covering the endothelium, is composed of glycosaminoglycans, proteoglycans, and adsorbed plasma proteins. This structure modulates vessels’ mechanotransduction, vascular permeability, and leukocyte adhesion. Thus, it regulates several physiological and pathological events. In the present review, we described the mechanisms that disturb glycocalyx stability such as reactive oxygen species, matrix metalloproteinases, and heparanase. We then focused our attention on the role of glycocalyx degradation in the induction of profibrotic events and on the possible pharmacological strategies to preserve this delicate structure.
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8
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Erkens R, Totzeck M, Brum A, Duse D, Bøtker HE, Rassaf T, Kelm M. Endothelium-dependent remote signaling in ischemia and reperfusion: Alterations in the cardiometabolic continuum. Free Radic Biol Med 2021; 165:265-281. [PMID: 33497796 DOI: 10.1016/j.freeradbiomed.2021.01.040] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/08/2020] [Revised: 01/15/2021] [Accepted: 01/19/2021] [Indexed: 02/07/2023]
Abstract
Intact endothelial function plays a fundamental role for the maintenance of cardiovascular (CV) health. The endothelium is also involved in remote signaling pathway-mediated protection against ischemia/reperfusion (I/R) injury. However, the transfer of these protective signals into clinical practice has been hampered by the complex metabolic alterations frequently observed in the cardiometabolic continuum, which affect redox balance and inflammatory pathways. Despite recent advances in determining the distinct roles of hyperglycemia, insulin resistance (InR), hyperinsulinemia, and ultimately diabetes mellitus (DM), which define the cardiometabolic continuum, our understanding of how these conditions modulate endothelial signaling remains challenging. It is widely accepted that endothelial cells (ECs) undergo functional changes within the cardiometabolic continuum. Beyond vascular tone and platelet-endothelium interaction, endothelial dysfunction may have profound negative effects on outcome during I/R. In this review, we summarize the current knowledge of the influence of hyperglycemia, InR, hyperinsulinemia, and DM on endothelial function and redox balance, their influence on remote protective signaling pathways, and their impact on potential therapeutic strategies to optimize protective heterocellular signaling.
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Affiliation(s)
- Ralf Erkens
- Department of Cardiology, Pulmonology and Angiology Medical Faculty, Heinrich Heine University of Düsseldorf, Düsseldorf, Germany.
| | - Matthias Totzeck
- Department of Cardiology and Vascular Medicine, West German Heart and Vascular Center, University Hospital Essen, Germany
| | - Amanda Brum
- Department of Cardiology, Pulmonology and Angiology Medical Faculty, Heinrich Heine University of Düsseldorf, Düsseldorf, Germany
| | - Dragos Duse
- Department of Cardiology, Pulmonology and Angiology Medical Faculty, Heinrich Heine University of Düsseldorf, Düsseldorf, Germany
| | - Hans Erik Bøtker
- Department of Cardiology, Institute of Clinical Medicine, Aarhus University Hospital, Denmark
| | - Tienush Rassaf
- Department of Cardiology and Vascular Medicine, West German Heart and Vascular Center, University Hospital Essen, Germany
| | - Malte Kelm
- Department of Cardiology, Pulmonology and Angiology Medical Faculty, Heinrich Heine University of Düsseldorf, Düsseldorf, Germany.
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9
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Dull RO, Chignalia AZ. The Glycocalyx and Pressure-Dependent Transcellular Albumin Transport. Cardiovasc Eng Technol 2020; 11:655-662. [PMID: 33006050 PMCID: PMC7782381 DOI: 10.1007/s13239-020-00489-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Accepted: 09/24/2020] [Indexed: 12/17/2022]
Abstract
Purpose Acute increases in hydrostatic pressure activate endothelial signaling pathways that modulate barrier function and vascular permeability. We investigated the role the glycocalyx and established mechanotransduction pathways in pressure-induced albumin transport across rat lung microvascular endothelial cells.
Methods Rat lung microvascular endothelial cells (RLMEC) were cultured on Costar Snapwell chambers. Cell morphology was assessed using silver nitrate staining. RLMEC were exposed to zero pressure (Control) or 30 cmH2O (Pressure) for 30 or 60 min. Intracellular albumin uptake and transcellular albumin transport was quantified. Transcellular transport was reported as solute flux (Js) and an effective permeability coefficient (Pe). The removal of cell surface heparan sulfates (heparinase), inhibition of NOS (L-NAME) and reactive oxygen species (apocynin, Apo) was investigated. Results Acute increase in hydrostatic pressure augmented albumin uptake by 30–40% at 60 min and Js and Pe both increased significantly. Heparinase increased albumin uptake but attenuated transcellular transport while L-NAME attenuated both pressure-dependent albumin uptake and transport. Apo interrupted albumin uptake under both control and pressure conditions, leading to a near total lack of transcellular transport, suggesting a different mechanism and/or site of action. Conclusion Pressure-dependent albumin uptake and transcellular transport is another component of endothelial mechanotransduction and associated regulation of solute flux. This novel albumin uptake and transport pathway is regulated by heparan sulfates and eNOS. Albumin uptake is sensitive to ROS. The physiological and clinical implications of this albumin transport are discussed.
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Affiliation(s)
- Randal O Dull
- Department of Anesthesiology, University of Illinois College of Medicine, Chicago, IL, USA. .,Department of Anesthesiology, Banner-University Medical Center, University of Arizona College of Medicine, Suite 4401, 1501 N. Campbell Avenue, Tucson, AZ, 85724-5114, USA. .,Department of Pathology, Banner-University Medical Center, University of Arizona College of Medicine, Tucson, AZ, USA. .,Department of Surgery, Banner-University Medical Center, University of Arizona College of Medicine, Tucson, AZ, USA.
| | - Andreia Z Chignalia
- Department of Anesthesiology, University of Illinois College of Medicine, Chicago, IL, USA.,Department of Anesthesiology, Banner-University Medical Center, University of Arizona College of Medicine, Suite 4401, 1501 N. Campbell Avenue, Tucson, AZ, 85724-5114, USA.,Department of Physiology, Banner-University Medical Center, University of Arizona College of Medicine, Tucson, AZ, USA.,Department of Pharmacology and Toxicology, College of Pharmacy, University of Arizona, Tucson, AZ, USA
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10
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The Glycocalyx and Its Role in Vascular Physiology and Vascular Related Diseases. Cardiovasc Eng Technol 2020; 12:37-71. [PMID: 32959164 PMCID: PMC7505222 DOI: 10.1007/s13239-020-00485-9] [Citation(s) in RCA: 51] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Accepted: 09/02/2020] [Indexed: 02/08/2023]
Abstract
Purpose In 2007 the two senior authors wrote a review on the structure and function of the endothelial glycocalyx layer (Weinbaum in Annu Rev Biomed Eng 9:121–167, 2007). Since then there has been an explosion of interest in this hydrated gel-like structure that coats the luminal surface of endothelial cells that line our vasculature due to its important functions in (A) basic vascular physiology and (B) vascular related diseases. This review will highlight the major advances that have occurred since our 2007 paper. Methods A literature search mainly focusing on the role of the glycocalyx in the two major areas described above was performed using electronic databases. Results In part (A) of this review, the new formulation of the century old Starling principle, now referred to as the Michel–Weinbaum glycoclayx model or revised Starling hypothesis, is described including new subtleties and physiological ramifications. New insights into mechanotransduction and release of nitric oxide due to fluid shear stress sensed by the glycocalyx are elaborated. Major advances in understanding the organization and function of glycocalyx components, and new techniques for measuring both its thickness and spatio-chemical organization based on super resolution, stochastic optical reconstruction microscopy (STORM) are presented. As discussed in part (B) of this review, it is now recognized that artery wall stiffness associated with hypertension and aging induces glycocalyx degradation, endothelial dysfunction and vascular disease. In addition to atherosclerosis and cardiovascular diseases, the glycocalyx plays an important role in lifestyle related diseases (e.g., diabetes) and cancer. Infectious diseases including sepsis, Dengue, Zika and Corona viruses, and malaria also involve the glycocalyx. Because of increasing recognition of the role of the glycocalyx in a wide range of diseases, there has been a vigorous search for methods to protect the glycocalyx from degradation or to enhance its synthesis in disease environments. Conclusion As we have seen in this review, many important developments in our basic understanding of GCX structure, function and role in diseases have been described since the 2007 paper. The future is wide open for continued GCX research.
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11
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Butler MJ, Down CJ, Foster RR, Satchell SC. The Pathological Relevance of Increased Endothelial Glycocalyx Permeability. THE AMERICAN JOURNAL OF PATHOLOGY 2020; 190:742-751. [PMID: 32035881 DOI: 10.1016/j.ajpath.2019.11.015] [Citation(s) in RCA: 63] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2019] [Revised: 10/25/2019] [Accepted: 11/22/2019] [Indexed: 01/06/2023]
Abstract
The endothelial glycocalyx is a vital regulator of vascular permeability. Damage to this delicate layer can result in increased protein and water transit. The clinical importance of albuminuria as a predictor of kidney disease progression and vascular disease has driven research in this area. This review outlines how research to date has attempted to measure the contribution of the endothelial glycocalyx to vessel wall permeability. We discuss the evidence for the role of the endothelial glycocalyx in regulating permeability in discrete areas of the vasculature and highlight the inherent limitations of the data that have been produced to date. In particular, this review emphasizes the difficulties in interpreting urinary albumin levels in early disease models. In addition, the research that supports the view that glycocalyx damage is a key pathologic step in a diverse array of clinical conditions, including diabetic complications, sepsis, preeclampsia, and atherosclerosis, is summarized. Finally, novel methods are discussed, including an ex vivo glomerular permeability assay that enhances the understanding of permeability changes in disease.
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Affiliation(s)
- Matthew J Butler
- Bristol Renal, Translational Health Sciences, Bristol Medical School, University of Bristol, Bristol, United Kingdom.
| | - Colin J Down
- Bristol Renal, Translational Health Sciences, Bristol Medical School, University of Bristol, Bristol, United Kingdom
| | - Rebecca R Foster
- Bristol Renal, Translational Health Sciences, Bristol Medical School, University of Bristol, Bristol, United Kingdom
| | - Simon C Satchell
- Bristol Renal, Translational Health Sciences, Bristol Medical School, University of Bristol, Bristol, United Kingdom
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12
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Zhang D, Qi BY, Zhu WW, Huang X, Wang XZ. Crocin alleviates lipopolysaccharide-induced acute respiratory distress syndrome by protecting against glycocalyx damage and suppressing inflammatory signaling pathways. Inflamm Res 2020; 69:267-278. [PMID: 31925528 PMCID: PMC7095881 DOI: 10.1007/s00011-019-01314-z] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2019] [Revised: 12/25/2019] [Accepted: 12/31/2019] [Indexed: 12/15/2022] Open
Abstract
Objective To explore the mechanisms of crocin against glycocalyx damage and inflammatory injury in lipopolysaccharide (LPS)-induced acute respiratory distress syndrome (ARDS) mice and LPS-stimulated human umbilical vein endothelial cells (HUVECs). Methods Mice were randomly divided into control, LPS, and crocin + LPS (15, 30, and 60 mg/kg) groups. HUVECs were separated into eight groups: control, crocin, matrix metalloproteinase 9 inhibitor (MMP-9 inhib), cathepsin L inhibitor (CTL inhib), LPS, MMP-9 inhib + LPS, CTL inhib + LPS, and crocin + LPS. The potential cytotoxic effect of crocin on HUVECs was mainly evaluated through methylthiazolyldiphenyl-tetrazolium bromide assay. Histological changes were assessed via hemotoxylin and eosin staining. Lung capillary permeability was detected on the basis of wet–dry ratio and through fluorescein isothiocyanate-albumin assay. Then, protein levels were detected through Western blot analysis, immunohistochemical staining, and immunofluorescence. Results This study showed that crocin can improve the pulmonary vascular permeability in mice with LPS-induced ARDS and inhibit the inflammatory signaling pathways of high mobility group box, nuclear factor κB, and mitogen-activated protein kinase in vivo and in vitro. Crocin also protected against the degradation of endothelial glycocalyx heparan sulfate and syndecan-4 by inhibiting the expressions of CTL, heparanase, and MMP-9 in vivo and in vitro. Overall, this study revealed the protective effects of crocin on LPS-induced ARDS and elaborated their underlying mechanism. Conclusion Crocin alleviated LPS-induced ARDS by protecting against glycocalyx damage and suppressing inflammatory signaling pathways.
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Affiliation(s)
- Dong Zhang
- Department of Respirator Medicine and Intensive Care Unit, Affiliated Hospital of Binzhou Medical University, Binzhou, 256603, Shandong, China
| | - Bo-Yang Qi
- Department of Respirator Medicine and Intensive Care Unit, Affiliated Hospital of Binzhou Medical University, Binzhou, 256603, Shandong, China
| | - Wei- Wei Zhu
- Department of Respirator Medicine and Intensive Care Unit, Affiliated Hospital of Binzhou Medical University, Binzhou, 256603, Shandong, China
| | - Xiao Huang
- Department of Respirator Medicine and Intensive Care Unit, Affiliated Hospital of Binzhou Medical University, Binzhou, 256603, Shandong, China
| | - Xiao-Zhi Wang
- Department of Respirator Medicine and Intensive Care Unit, Affiliated Hospital of Binzhou Medical University, Binzhou, 256603, Shandong, China.
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Abstract
Objective: The endothelial glycocalyx (eGC) is a dynamic and multicomponent layer of macromolecules found at the surface of vascular endothelium, which is largely underappreciated. It has recently been recognized that eGC is a major regulator of endothelial function and may have therapeutic value in organ injuries. This study aimed to explore the role of the eGC in various pathologic and physiologic conditions, by reviewing the basic research findings pertaining to the detection of the eGC and its clinical significance. We also explored different pharmacologic agents used to protect and rebuild the eGC. Data sources: An in-depth search was performed in the PubMed database, focusing on research published after 2003 with keywords including eGC, permeability, glycocalyx and injuries, and glycocalyx protection. Study selection: Several authoritative reviews and original studies were identified and reviewed to summarize the characteristics of the eGC under physiologic and pathologic conditions as well as the detection and protection of the eGC. Results: The eGC degradation is closely associated with pathophysiologic changes such as vascular permeability, edema formation, mechanotransduction, and clotting cascade, together with neutrophil and platelet adhesion in diverse injury and disease states including inflammation (sepsis and trauma), ischemia-reperfusion injury, shock, hypervolemia, hypertension, hyperglycemia, and high Na+ as well as diabetes and atherosclerosis. Therapeutic strategies for protecting and rebuilding the eGC should be explored through experimental test and clinical verifications. Conclusions: Disturbance of the eGC usually occurs at early stages of various clinical pathophysiologies which can be partly prevented and reversed by protecting and restoring the eGC. The eGC seems to be a promising diagnostic biomarker and therapeutic target in clinical settings.
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Patel M, Chignalia AZ, Isbatan A, Bommakanti N, Dull RO. Ropivacaine inhibits pressure-induced lung endothelial hyperpermeability in models of acute hypertension. Life Sci 2019; 222:22-28. [PMID: 30822427 DOI: 10.1016/j.lfs.2019.02.053] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2018] [Revised: 02/18/2019] [Accepted: 02/25/2019] [Indexed: 11/18/2022]
Abstract
AIMS Increases in hydrostatic pressure results in endothelial hyperpermeability via eNOS-dependent pathways. Ropivacaine is known to inhibit eNOS activation and to attenuate lung injury. Herein, we sought to determine if ropivacaine regulates pressure-induced lung endothelial hyperpermeability. MAIN METHODS The effects of ropivacaine on lung permeability were assessed in two models of acute hypertension (AH): the isolated perfused lung preparation where acute increases in left atrial pressure model the hemodynamic changes of severe hypertension, and an animal model of AH induced by norepinephrine. In the IPL model, whole lung filtration coefficient (Kf) was used as the index of lung permeability; pulmonary artery pressure (Ppa), pulmonary capillary pressures (Ppc), and zonal characteristics (ZC) were measured to assess the effects of ropivacaine on hemodynamics and their relationship to Kf2/Kf1. In vivo, ropivacaine effects were investigated on indices of pulmonary edema (changes in PaO2, lung wet-to-dry ratio), changes in plasma volume and nitric oxide (NO) production. KEY FINDINGS Ropivacaine provided robust protection from pressure-dependent barrier failure; it inhibited pressure-induced increases in Kf without affecting Ppa, Ppc or ZC. In vivo, ropivacaine prevented pressure-induced lung edema and associated hyperpermeability as evidence by maintaining PaO2, lung wet-to-dry ratio and plasma volume in levels similar to sham rats. Ropivacaine inhibited pressure-induced NO production as evidenced by decreased lung nitro-tyrosine content when compared to hypertensive lungs. SIGNIFICANCE Collectively these data show that ropivacaine inhibits pressure-induced lung endothelial hyperpermeability and suggest that ropivacaine may be a clinically useful agent to prevent endothelial hyperpermeability when pulmonary pressure is acutely increased.
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Affiliation(s)
- Milan Patel
- Department of Anesthesiology, University of Illinois at Chicago. 1740 West Taylor Street, Suite 3200, Chicago, Il 60612, USA
| | - Andreia Z Chignalia
- Department of Anesthesiology, University of Illinois at Chicago. 1740 West Taylor Street, Suite 3200, Chicago, Il 60612, USA; Department of Anesthesiology, University of Arizona COM and Banner-University Medical Center, Suite 4401, Room 4443, 1501 N. Campbell Avenue, PO Box 245114, Tucson, AZ 85724, USA.
| | - Ayman Isbatan
- Department of Anesthesiology, University of Illinois at Chicago. 1740 West Taylor Street, Suite 3200, Chicago, Il 60612, USA
| | - Nikhil Bommakanti
- Department of Anesthesiology, University of Illinois at Chicago. 1740 West Taylor Street, Suite 3200, Chicago, Il 60612, USA
| | - Randal O Dull
- Department of Anesthesiology, University of Illinois at Chicago. 1740 West Taylor Street, Suite 3200, Chicago, Il 60612, USA; Department of Anesthesiology, University of Arizona COM and Banner-University Medical Center, Suite 4401, Room 4443, 1501 N. Campbell Avenue, PO Box 245114, Tucson, AZ 85724, USA
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15
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Chignalia AZ, Isbatan A, Patel M, Ripper R, Sharlin J, Shosfy J, Borlaug BA, Dull RO. Pressure-dependent NOS activation contributes to endothelial hyperpermeability in a model of acute heart failure. Biosci Rep 2018; 38:BSR20181239. [PMID: 30355657 PMCID: PMC6250809 DOI: 10.1042/bsr20181239] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2018] [Revised: 10/11/2018] [Accepted: 10/21/2018] [Indexed: 12/12/2022] Open
Abstract
Aims: Acute increases in left ventricular end diastolic pressure (LVEDP) can induce pulmonary edema (PE). The mechanism(s) for this rapid onset edema may involve more than just increased fluid filtration. Lung endothelial cell permeability is regulated by pressure-dependent activation of nitric oxide synthase (NOS). Herein, we demonstrate that pressure-dependent NOS activation contributes to vascular failure and PE in a model of acute heart failure (AHF) caused by hypertension.Methods and results: Male Sprague-Dawley rats were anesthetized and mechanically ventilated. Acute hypertension was induced by norepinephrine (NE) infusion and resulted in an increase in LVEDP and pulmonary artery pressure (Ppa) that were associated with a rapid fall in PaO2, and increases in lung wet/dry ratio and injury scores. Heart failure (HF) lungs showed increased nitrotyrosine content and ROS levels. L-NAME pretreatment mitigated the development of PE and reduced lung ROS concentrations to sham levels. Apocynin (Apo) pretreatment inhibited PE. Addition of tetrahydrobiopterin (BH4) to AHF rats lung lysates and pretreatment of AHF rats with folic acid (FA) prevented ROS production indicating endothelial NOS (eNOS) uncoupling.Conclusion: Pressure-dependent NOS activation leads to acute endothelial hyperpermeability and rapid PE by an increase in NO and ROS in a model of AHF. Acute increases in pulmonary vascular pressure, without NOS activation, was insufficient to cause significant PE. These results suggest a clinically relevant role of endothelial mechanotransduction in the pathogenesis of AHF and further highlights the concept of active barrier failure in AHF. Therapies targetting the prevention or reversal of endothelial hyperpermeability may be a novel therapeutic strategy in AHF.
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Affiliation(s)
- Andreia Z Chignalia
- Department of Anesthesiology, University of Illinois at Chicago, Chicago, IL 60612, U.S.A.
| | - Ayman Isbatan
- Department of Anesthesiology, University of Illinois at Chicago, Chicago, IL 60612, U.S.A
| | - Milan Patel
- Department of Anesthesiology, University of Illinois at Chicago, Chicago, IL 60612, U.S.A
| | - Richard Ripper
- Department of Anesthesiology, University of Illinois at Chicago, Chicago, IL 60612, U.S.A
- Research and Development Service, Jesse Brown Veterans Affairs Medical Center, 820 S Damen Ave., Chicago, IL 60612, U.S.A
| | - Jordan Sharlin
- Department of Anesthesiology, University of Illinois at Chicago, Chicago, IL 60612, U.S.A
| | - Joelle Shosfy
- Department of Anesthesiology, University of Illinois at Chicago, Chicago, IL 60612, U.S.A
| | - Barry A Borlaug
- Department of Cardiovascular Medicine, Mayo Clinic and Foundation, 200 First St SW, Rochester, MN 55905, U.S.A
| | - Randal O Dull
- Department of Anesthesiology, University of Illinois at Chicago, Chicago, IL 60612, U.S.A
- Department of Anesthesiology, University of Arizona College of Medicine and Banner-University Medical Center, Tucson, AZ 85724, U.S.A
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Song JW, Goligorsky MS. Perioperative implication of the endothelial glycocalyx. Korean J Anesthesiol 2018; 71:92-102. [PMID: 29619781 PMCID: PMC5903118 DOI: 10.4097/kjae.2018.71.2.92] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2018] [Revised: 03/25/2018] [Accepted: 03/25/2018] [Indexed: 11/10/2022] Open
Abstract
The endothelial glycocalyx (EG) is a gel-like layer lining the luminal surface of healthy vascular endothelium. Recently, the EG has gained extensive interest as a crucial regulator of endothelial funtction, including vascular permeability, mechanotransduction, and the interaction between endothelial and circulating blood cells. The EG is degraded by various enzymes and reactive oxygen species upon pro-inflammatory stimulus. Ischemia-reperfusion injury, oxidative stress, hypervolemia, and systemic inflammatory response are responsible for perioperative EG degradation. Perioperative damage of the EG has also been demonstrated, especially in cardiac surgery. However, the protection of the EG and its association with perioperative morbidity needs to be elucidated in future studies. In this review, the present knowledge about EG and its perioperative implication is discussed from an anesthesiologist's perspective.
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Affiliation(s)
- Jong Wook Song
- Department of Anesthesiology and Pain Medicine, Yonsei University College of Medicine, Seoul, Korea
| | - Michael S Goligorsky
- Renal Research Institute and Departments of Medicine, Pharmacology, and Physiology, New York Medical College, Valhalla, NY, USA
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17
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Bommakanti N, Isbatan A, Bavishi A, Dharmavaram G, Chignalia AZ, Dull RO. Hypercapnic acidosis attenuates pressure-dependent increase in whole-lung filtration coefficient (K f). Pulm Circ 2017; 7:719-726. [PMID: 28727979 PMCID: PMC5841912 DOI: 10.1177/2045893217724414] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Hypercapnic acidosis (HCA) has beneficial effects in experimental models of lung injury by attenuating inflammation and decreasing pulmonary edema. However, HCA increases pulmonary vascular pressure that will increase fluid filtration and worsen edema development. To reconcile these disparate effects, we tested the hypothesis that HCA inhibits endothelial mechanotransduction and protects against pressure-dependent increases in the whole lung filtration coefficient (Kf). Isolated perfused rat lung preparation was used to measure whole lung filtration coefficient (Kf) at two levels of left atrial pressure (PLA = 7.5 versus 15 cm H2O) and at low tidal volume (LVt) versus standard tidal volume (STVt) ventilation. The ratio of Kf2/Kf1 was used as the index of whole lung permeability. Double occlusion pressure, pulmonary artery pressure, pulmonary capillary pressures, and zonal characteristics (ZC) were measured to assess effects of HCA on hemodynamics and their relationship to Kf2/Kf1. An increase in PLA2 from 7.5 to 15 cm H2O resulted in a 4.9-fold increase in Kf2/Kf1 during LVt and a 4.8-fold increase during STVt. During LVt, HCA reduced Kf2/Kf1 by 2.7-fold and reduced STVt Kf2/Kf1 by 5.2-fold. Analysis of pulmonary hemodynamics revealed no significant differences in filtration forces in response to HCA. HCA interferes with lung vascular mechanotransduction and prevents pressure-dependent increases in whole lung filtration coefficient. These results contribute to a further understanding of the lung protective effects of HCA.
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Affiliation(s)
- Nikhil Bommakanti
- 1 Department of Anesthesiology, University of Illinois at Chicago, College of Medicine, Chicago, IL, USA.,2 Department of Bioengineering, University of Illinois at Chicago, College of Medicine, Chicago, IL, USA
| | - Ayman Isbatan
- 1 Department of Anesthesiology, University of Illinois at Chicago, College of Medicine, Chicago, IL, USA.,3 Lung Vascular Biology Laboratory, University of Illinois at Chicago, College of Medicine, Chicago, IL, USA
| | - Avni Bavishi
- 1 Department of Anesthesiology, University of Illinois at Chicago, College of Medicine, Chicago, IL, USA.,3 Lung Vascular Biology Laboratory, University of Illinois at Chicago, College of Medicine, Chicago, IL, USA
| | - Gourisree Dharmavaram
- 1 Department of Anesthesiology, University of Illinois at Chicago, College of Medicine, Chicago, IL, USA.,3 Lung Vascular Biology Laboratory, University of Illinois at Chicago, College of Medicine, Chicago, IL, USA
| | - Andreia Z Chignalia
- 1 Department of Anesthesiology, University of Illinois at Chicago, College of Medicine, Chicago, IL, USA.,3 Lung Vascular Biology Laboratory, University of Illinois at Chicago, College of Medicine, Chicago, IL, USA
| | - Randal O Dull
- 1 Department of Anesthesiology, University of Illinois at Chicago, College of Medicine, Chicago, IL, USA.,2 Department of Bioengineering, University of Illinois at Chicago, College of Medicine, Chicago, IL, USA.,3 Lung Vascular Biology Laboratory, University of Illinois at Chicago, College of Medicine, Chicago, IL, USA
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18
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Assaad S, Kratzert WB, Shelley B, Friedman MB, Perrino A. Assessment of Pulmonary Edema: Principles and Practice. J Cardiothorac Vasc Anesth 2017; 32:901-914. [PMID: 29174750 DOI: 10.1053/j.jvca.2017.08.028] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/08/2017] [Indexed: 12/24/2022]
Abstract
Pulmonary edema increasingly is recognized as a perioperative complication affecting outcome. Several risk factors have been identified, including those of cardiogenic origin, such as heart failure or excessive fluid administration, and those related to increased pulmonary capillary permeability secondary to inflammatory mediators. Effective treatment requires prompt diagnosis and early intervention. Consequently, over the past 2 centuries a concentrated effort to develop clinical tools to rapidly diagnose pulmonary edema and track response to treatment has occurred. The ideal properties of such a tool would include high sensitivity and specificity, easy availability, and the ability to diagnose early accumulation of lung water before the development of the full clinical presentation. In addition, clinicians highly value the ability to precisely quantify extravascular lung water accumulation and differentiate hydrostatic from high permeability etiologies of pulmonary edema. In this review, advances in understanding the physiology of extravascular lung water accumulation in health and in disease and the various mechanisms that protect against the development of pulmonary edema under physiologic conditions are discussed. In addition, the various bedside modalities available to diagnose early accumulation of extravascular lung water and pulmonary edema, including chest auscultation, chest roentgenography, lung ultrasonography, and transpulmonary thermodilution, are examined. Furthermore, advantages and limitations of these methods for the operating room and intensive care unit that are critical for proper modality selection in each individual case are explored.
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Affiliation(s)
- Sherif Assaad
- Cardiothoracic Anesthesia Service, VA Connecticut Healthcare System, Yale University School of Medicine, New Haven, CT.
| | - Wolf B Kratzert
- Department of Anesthesiology and Perioperative Medicine, David Geffen School of Medicine at University of California at Los Angeles, Los Angeles, CA
| | - Benjamin Shelley
- Golden Jubilee National Hospital /West of Scotland Heart and Lung Centre, University of Glasgow, Glasgow, Scotland
| | - Malcolm B Friedman
- Department of Radiology and Biomedical Imaging, Yale University School of Medicine, VA Connecticut Healthcare System, New Haven, CT
| | - Albert Perrino
- Cardiothoracic Anesthesia Service, VA Connecticut Healthcare System, Yale University School of Medicine, New Haven, CT
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19
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Job KM, O'Callaghan R, Hlady V, Barabanova A, Dull RO. The Biomechanical Effects of Resuscitation Colloids on the Compromised Lung Endothelial Glycocalyx. Anesth Analg 2017; 123:382-93. [PMID: 27331777 DOI: 10.1213/ane.0000000000001284] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
BACKGROUND The endothelial glycocalyx is an important component of the vascular permeability barrier, forming a scaffold that allows serum proteins to create a gel-like layer on the endothelial surface and transmitting mechanosensing and mechanotransduction information that influences permeability. During acute inflammation, the glycocalyx is degraded, changing how it interacts with serum proteins and colloids used during resuscitation and altering its barrier properties and biomechanical characteristics. We quantified changes in the biomechanical properties of lung endothelial glycocalyx during control conditions and after degradation by hyaluronidase using biophysical techniques that can probe mechanics at (1) the aqueous/glycocalyx interface and (2) inside the glycocalyx. Our goal was to discern the location-specific effects of albumin and hydroxyethyl starch (HES) on glycocalyx function. METHODS The effects of albumin and HES on the mechanical properties of bovine lung endothelial glycocalyx were studied using a combination of atomic force microscopy and reflectance interference contrast microscopy. Logistic regression was used to determine the odds ratios for comparing the effects of varying concentrations of albumin and HES on the glycocalyx with and without hyaluronidase. RESULTS Atomic force microscopy measurements demonstrated that both 0.1% and 4% albumin increased the thickness and reduced the stiffness of glycocalyx when compared with 1% albumin. The effect of HES on glycocalyx thickness was similar to albumin, with thickness increasing significantly between 0.1% and 1% HES and a trend toward a softer glycocalyx at 4% HES. Reflectance interference contrast microscopy revealed a concentration-dependent softening of the glycocalyx in the presence of albumin, but a concentration-dependent increase in stiffness with HES. After glycocalyx degradation with hyaluronidase, stiffness was increased only at 4% albumin and 1% HES. CONCLUSIONS Albumin and HES induced markedly different effects on glycocalyx mechanics and had notably different effects after glycocalyx degradation by hyaluronidase. We conclude that HES is not comparable with albumin for studies of vascular permeability and glycocalyx-dependent signaling. Characterizing the molecular and biomechanical effects of resuscitation colloids on the glycocalyx should clarify their indicated uses and permit a better understanding of how HES and albumin affect vascular function.
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Affiliation(s)
- Kathleen M Job
- From the *Department of Bioengineering, University of Utah, Salt lake City, Utah; and †Department of Anesthesiology, University of Illinois Chicago, Chicago, Illinois
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20
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Lukasz A, Hillgruber C, Oberleithner H, Kusche-Vihrog K, Pavenstädt H, Rovas A, Hesse B, Goerge T, Kümpers P. Endothelial glycocalyx breakdown is mediated by angiopoietin-2. Cardiovasc Res 2017; 113:671-680. [PMID: 28453727 DOI: 10.1093/cvr/cvx023] [Citation(s) in RCA: 91] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/01/2016] [Accepted: 01/31/2017] [Indexed: 01/01/2023] Open
Abstract
AIMS The endothelial glycocalyx (eGC), a carbohydrate-rich layer lining the luminal surface of the endothelium, provides a first vasoprotective barrier against vascular leakage and adhesion in sepsis and vessel inflammation. Angiopoietin-2 (Angpt-2), an antagonist of the endothelium-stabilizing receptor Tie2 secreted by endothelial cells, promotes vascular permeability through cellular contraction and junctional disintegration. We hypothesized that Angpt-2 might also mediate the breakdown of the eGC. METHODS AND RESULTS Using confocal and atomic force microscopy, we show that exogenous Angpt-2 induces a rapid loss of the eGC in endothelial cells in vitro. Glycocalyx deterioration involves the specific loss of its main constituent heparan sulphate, paralleled by the secretion of the heparan sulphate-specific heparanase from late endosomal/lysosomal stores. Corresponding in vivo experiments revealed that exogenous Angpt-2 leads to heparanase-dependent eGC breakdown, which contributes to plasma leakage and leukocyte recruitment in vivo. CONCLUSION Our data indicate that eGC breakdown is mediated by Angpt-2 in a non-redundant manner.
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Affiliation(s)
- Alexander Lukasz
- Department of Medicine D, Division of General Internal Medicine, Nephrology, and Rheumatology, University Hospital Münster, Albert-Schweitzer-Campus 1, 48149 Münster, Germany
- Institute of Physiology II, University Hospital Münster, Robert-Koch-Straße 27b, 48149 Münster, Germany
| | - Carina Hillgruber
- Department of Dermatology, University Hospital Münster, Von-Esmarch-Straße 58, 48149 Münster, Germany
| | - Hans Oberleithner
- Institute of Physiology II, University Hospital Münster, Robert-Koch-Straße 27b, 48149 Münster, Germany
| | - Kristina Kusche-Vihrog
- Institute of Physiology II, University Hospital Münster, Robert-Koch-Straße 27b, 48149 Münster, Germany
| | - Hermann Pavenstädt
- Department of Medicine D, Division of General Internal Medicine, Nephrology, and Rheumatology, University Hospital Münster, Albert-Schweitzer-Campus 1, 48149 Münster, Germany
| | - Alexandros Rovas
- Department of Medicine D, Division of General Internal Medicine, Nephrology, and Rheumatology, University Hospital Münster, Albert-Schweitzer-Campus 1, 48149 Münster, Germany
| | - Bettina Hesse
- Department of Medicine D, Division of General Internal Medicine, Nephrology, and Rheumatology, University Hospital Münster, Albert-Schweitzer-Campus 1, 48149 Münster, Germany
- Institute of Physiology II, University Hospital Münster, Robert-Koch-Straße 27b, 48149 Münster, Germany
| | - Tobias Goerge
- Department of Dermatology, University Hospital Münster, Von-Esmarch-Straße 58, 48149 Münster, Germany
| | - Philipp Kümpers
- Department of Medicine D, Division of General Internal Medicine, Nephrology, and Rheumatology, University Hospital Münster, Albert-Schweitzer-Campus 1, 48149 Münster, Germany
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Rat Liver Enzyme Release Depends on Blood Flow-Bearing Physical Forces Acting in Endothelium Glycocalyx rather than on Liver Damage. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2017; 2017:1360565. [PMID: 28337244 PMCID: PMC5350326 DOI: 10.1155/2017/1360565] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/04/2016] [Accepted: 12/29/2016] [Indexed: 12/03/2022]
Abstract
We have found selective elevation of serum enzyme activities in rats subjected to partial hepatectomy (PH), apparently controlled by hemodynamic flow-bearing physical forces. Here, we assess the involvement of stretch-sensitive calcium channels and calcium mobilization in isolated livers, after chemical modifications of the endothelial glycocalyx and changing perfusion directionality. Inhibiting in vivo protein synthesis, we found that liver enzyme release is influenced by de novo synthesis of endothelial glycocalyx components, and released enzymes are confined into a liver “pool.” Moreover, liver enzyme release depended on extracellular calcium entry possibly mediated by stretch-sensitive calcium channels, and this endothelial-mediated mechanotransduction in liver enzyme release was also evidenced by modifying the glycocalyx carbohydrate components, directionality of perfusing flow rate, and the participation of nitric oxide (NO) and malondialdehyde (MDA), leading to modifications in the intracellular distribution of these enzymes mainly as nuclear enrichment of “mitochondrial” enzymes. In conclusion, the flow-induced shear stress may provide fine-tuned control of released hepatic enzymes through mediation by the endothelium glycocalyx, which provides evidence of a biological role of the enzyme release rather to be merely a biomarker for evaluating hepatotoxicity and liver damage, actually positively influencing progression of liver regeneration in mammals.
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Abstract
In the United States trauma is the leading cause of mortality among those under the age of 45, claiming approximately 192,000 lives each year. Significant personal disability, lost productivity, and long-term healthcare needs are common and contribute 580 billion dollars in economic impact each year. Improving resuscitation strategies and the early acute care of trauma patients has the potential to reduce the pathological sequelae of combined exuberant inflammation and immune suppression that can co-exist, or occur temporally, and adversely affect outcomes. The endothelial and epithelial glycocalyx has emerged as an important participant in both inflammation and immunomodulation. Constituents of the glycocalyx have been used as biomarkers of injury severity and have the potential to be target(s) for therapeutic interventions aimed at immune modulation. In this review, we provide a contemporary understanding of the physiologic structure and function of the glycocalyx and its role in traumatic injury with a particular emphasis on lung injury.
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Dimitrievska S, Gui L, Weyers A, Lin T, Cai C, Wu W, Tuggle CT, Sundaram S, Balestrini JL, Slattery D, Tchouta L, Kyriakides TR, Tarbell JM, Linhardt RJ, Niklason LE. New Functional Tools for Antithrombogenic Activity Assessment of Live Surface Glycocalyx. Arterioscler Thromb Vasc Biol 2016; 36:1847-53. [PMID: 27386939 DOI: 10.1161/atvbaha.116.308023] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2016] [Accepted: 06/15/2016] [Indexed: 12/12/2022]
Abstract
OBJECTIVE It is widely accepted that the presence of a glycosaminoglycan-rich glycocalyx is essential for endothelialized vasculature health; in fact, a damaged or impaired glycocalyx has been demonstrated in many vascular diseases. Currently, there are no methods that characterize glycocalyx functionality, thus limiting investigators' ability to assess the role of the glycocalyx in vascular health. APPROACH AND RESULTS We have developed novel, easy-to-use, in vitro assays that directly quantify live endothelialized surface's functional heparin weights and their anticoagulant capacity to inactivate Factor Xa and thrombin. Using our assays, we characterized 2 commonly used vascular models: native rat aorta and cultured human umbilical vein endothelial cell monolayer. We determined heparin contents to be ≈10 000 ng/cm(2) on the native aorta and ≈10-fold lower on cultured human umbilical vein endothelial cells. Interestingly, human umbilical vein endothelial cells demonstrated a 5-fold lower anticoagulation capacity in inactivating both Factor Xa and thrombin relative to native aortas. We verified the validity and accuracy of the novel assays developed in this work using liquid chromatography-mass spectrometry analysis. CONCLUSIONS Our assays are of high relevance in the vascular community because they can be used to establish the antithrombogenic capacity of many different types of surfaces such as vascular grafts and transplants. This work will also advance the capacity for glycocalyx-targeting therapeutics development to treat damaged vasculatures.
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Affiliation(s)
- Sashka Dimitrievska
- From the Department of Biomedical Engineering (S.D., T.L., W.W., T.R.K., L.E.N.), Department of Anesthesiology (L.G., S.S., J.L.B., L.E.N.), Department of Surgery (W.W., C.T.T.), Department of Medicine (L.T.), and Department of Pharmacology (T.R.K.), Yale University, New Haven, CT; Howard Hughes Medical Institute, Chevy Chase, MD (S.D., R.J.L.); Department of Chemical and Biological Engineering, Rensselaer Polytechnic Institute, Troy, NY (A.W., C.C., R.J.L.); Department of Biomedical Engineering, University of Connecticut, Storrs (D.S.); and Department of Biomedical Engineering, The City College of New York (J.M.T.)
| | - Liqiong Gui
- From the Department of Biomedical Engineering (S.D., T.L., W.W., T.R.K., L.E.N.), Department of Anesthesiology (L.G., S.S., J.L.B., L.E.N.), Department of Surgery (W.W., C.T.T.), Department of Medicine (L.T.), and Department of Pharmacology (T.R.K.), Yale University, New Haven, CT; Howard Hughes Medical Institute, Chevy Chase, MD (S.D., R.J.L.); Department of Chemical and Biological Engineering, Rensselaer Polytechnic Institute, Troy, NY (A.W., C.C., R.J.L.); Department of Biomedical Engineering, University of Connecticut, Storrs (D.S.); and Department of Biomedical Engineering, The City College of New York (J.M.T.)
| | - Amanda Weyers
- From the Department of Biomedical Engineering (S.D., T.L., W.W., T.R.K., L.E.N.), Department of Anesthesiology (L.G., S.S., J.L.B., L.E.N.), Department of Surgery (W.W., C.T.T.), Department of Medicine (L.T.), and Department of Pharmacology (T.R.K.), Yale University, New Haven, CT; Howard Hughes Medical Institute, Chevy Chase, MD (S.D., R.J.L.); Department of Chemical and Biological Engineering, Rensselaer Polytechnic Institute, Troy, NY (A.W., C.C., R.J.L.); Department of Biomedical Engineering, University of Connecticut, Storrs (D.S.); and Department of Biomedical Engineering, The City College of New York (J.M.T.)
| | - Tylee Lin
- From the Department of Biomedical Engineering (S.D., T.L., W.W., T.R.K., L.E.N.), Department of Anesthesiology (L.G., S.S., J.L.B., L.E.N.), Department of Surgery (W.W., C.T.T.), Department of Medicine (L.T.), and Department of Pharmacology (T.R.K.), Yale University, New Haven, CT; Howard Hughes Medical Institute, Chevy Chase, MD (S.D., R.J.L.); Department of Chemical and Biological Engineering, Rensselaer Polytechnic Institute, Troy, NY (A.W., C.C., R.J.L.); Department of Biomedical Engineering, University of Connecticut, Storrs (D.S.); and Department of Biomedical Engineering, The City College of New York (J.M.T.)
| | - Chao Cai
- From the Department of Biomedical Engineering (S.D., T.L., W.W., T.R.K., L.E.N.), Department of Anesthesiology (L.G., S.S., J.L.B., L.E.N.), Department of Surgery (W.W., C.T.T.), Department of Medicine (L.T.), and Department of Pharmacology (T.R.K.), Yale University, New Haven, CT; Howard Hughes Medical Institute, Chevy Chase, MD (S.D., R.J.L.); Department of Chemical and Biological Engineering, Rensselaer Polytechnic Institute, Troy, NY (A.W., C.C., R.J.L.); Department of Biomedical Engineering, University of Connecticut, Storrs (D.S.); and Department of Biomedical Engineering, The City College of New York (J.M.T.)
| | - Wei Wu
- From the Department of Biomedical Engineering (S.D., T.L., W.W., T.R.K., L.E.N.), Department of Anesthesiology (L.G., S.S., J.L.B., L.E.N.), Department of Surgery (W.W., C.T.T.), Department of Medicine (L.T.), and Department of Pharmacology (T.R.K.), Yale University, New Haven, CT; Howard Hughes Medical Institute, Chevy Chase, MD (S.D., R.J.L.); Department of Chemical and Biological Engineering, Rensselaer Polytechnic Institute, Troy, NY (A.W., C.C., R.J.L.); Department of Biomedical Engineering, University of Connecticut, Storrs (D.S.); and Department of Biomedical Engineering, The City College of New York (J.M.T.)
| | - Charles T Tuggle
- From the Department of Biomedical Engineering (S.D., T.L., W.W., T.R.K., L.E.N.), Department of Anesthesiology (L.G., S.S., J.L.B., L.E.N.), Department of Surgery (W.W., C.T.T.), Department of Medicine (L.T.), and Department of Pharmacology (T.R.K.), Yale University, New Haven, CT; Howard Hughes Medical Institute, Chevy Chase, MD (S.D., R.J.L.); Department of Chemical and Biological Engineering, Rensselaer Polytechnic Institute, Troy, NY (A.W., C.C., R.J.L.); Department of Biomedical Engineering, University of Connecticut, Storrs (D.S.); and Department of Biomedical Engineering, The City College of New York (J.M.T.)
| | - Sumati Sundaram
- From the Department of Biomedical Engineering (S.D., T.L., W.W., T.R.K., L.E.N.), Department of Anesthesiology (L.G., S.S., J.L.B., L.E.N.), Department of Surgery (W.W., C.T.T.), Department of Medicine (L.T.), and Department of Pharmacology (T.R.K.), Yale University, New Haven, CT; Howard Hughes Medical Institute, Chevy Chase, MD (S.D., R.J.L.); Department of Chemical and Biological Engineering, Rensselaer Polytechnic Institute, Troy, NY (A.W., C.C., R.J.L.); Department of Biomedical Engineering, University of Connecticut, Storrs (D.S.); and Department of Biomedical Engineering, The City College of New York (J.M.T.)
| | - Jenna L Balestrini
- From the Department of Biomedical Engineering (S.D., T.L., W.W., T.R.K., L.E.N.), Department of Anesthesiology (L.G., S.S., J.L.B., L.E.N.), Department of Surgery (W.W., C.T.T.), Department of Medicine (L.T.), and Department of Pharmacology (T.R.K.), Yale University, New Haven, CT; Howard Hughes Medical Institute, Chevy Chase, MD (S.D., R.J.L.); Department of Chemical and Biological Engineering, Rensselaer Polytechnic Institute, Troy, NY (A.W., C.C., R.J.L.); Department of Biomedical Engineering, University of Connecticut, Storrs (D.S.); and Department of Biomedical Engineering, The City College of New York (J.M.T.)
| | - David Slattery
- From the Department of Biomedical Engineering (S.D., T.L., W.W., T.R.K., L.E.N.), Department of Anesthesiology (L.G., S.S., J.L.B., L.E.N.), Department of Surgery (W.W., C.T.T.), Department of Medicine (L.T.), and Department of Pharmacology (T.R.K.), Yale University, New Haven, CT; Howard Hughes Medical Institute, Chevy Chase, MD (S.D., R.J.L.); Department of Chemical and Biological Engineering, Rensselaer Polytechnic Institute, Troy, NY (A.W., C.C., R.J.L.); Department of Biomedical Engineering, University of Connecticut, Storrs (D.S.); and Department of Biomedical Engineering, The City College of New York (J.M.T.)
| | - Lise Tchouta
- From the Department of Biomedical Engineering (S.D., T.L., W.W., T.R.K., L.E.N.), Department of Anesthesiology (L.G., S.S., J.L.B., L.E.N.), Department of Surgery (W.W., C.T.T.), Department of Medicine (L.T.), and Department of Pharmacology (T.R.K.), Yale University, New Haven, CT; Howard Hughes Medical Institute, Chevy Chase, MD (S.D., R.J.L.); Department of Chemical and Biological Engineering, Rensselaer Polytechnic Institute, Troy, NY (A.W., C.C., R.J.L.); Department of Biomedical Engineering, University of Connecticut, Storrs (D.S.); and Department of Biomedical Engineering, The City College of New York (J.M.T.)
| | - Themis R Kyriakides
- From the Department of Biomedical Engineering (S.D., T.L., W.W., T.R.K., L.E.N.), Department of Anesthesiology (L.G., S.S., J.L.B., L.E.N.), Department of Surgery (W.W., C.T.T.), Department of Medicine (L.T.), and Department of Pharmacology (T.R.K.), Yale University, New Haven, CT; Howard Hughes Medical Institute, Chevy Chase, MD (S.D., R.J.L.); Department of Chemical and Biological Engineering, Rensselaer Polytechnic Institute, Troy, NY (A.W., C.C., R.J.L.); Department of Biomedical Engineering, University of Connecticut, Storrs (D.S.); and Department of Biomedical Engineering, The City College of New York (J.M.T.)
| | - John M Tarbell
- From the Department of Biomedical Engineering (S.D., T.L., W.W., T.R.K., L.E.N.), Department of Anesthesiology (L.G., S.S., J.L.B., L.E.N.), Department of Surgery (W.W., C.T.T.), Department of Medicine (L.T.), and Department of Pharmacology (T.R.K.), Yale University, New Haven, CT; Howard Hughes Medical Institute, Chevy Chase, MD (S.D., R.J.L.); Department of Chemical and Biological Engineering, Rensselaer Polytechnic Institute, Troy, NY (A.W., C.C., R.J.L.); Department of Biomedical Engineering, University of Connecticut, Storrs (D.S.); and Department of Biomedical Engineering, The City College of New York (J.M.T.)
| | - Robert J Linhardt
- From the Department of Biomedical Engineering (S.D., T.L., W.W., T.R.K., L.E.N.), Department of Anesthesiology (L.G., S.S., J.L.B., L.E.N.), Department of Surgery (W.W., C.T.T.), Department of Medicine (L.T.), and Department of Pharmacology (T.R.K.), Yale University, New Haven, CT; Howard Hughes Medical Institute, Chevy Chase, MD (S.D., R.J.L.); Department of Chemical and Biological Engineering, Rensselaer Polytechnic Institute, Troy, NY (A.W., C.C., R.J.L.); Department of Biomedical Engineering, University of Connecticut, Storrs (D.S.); and Department of Biomedical Engineering, The City College of New York (J.M.T.)
| | - Laura E Niklason
- From the Department of Biomedical Engineering (S.D., T.L., W.W., T.R.K., L.E.N.), Department of Anesthesiology (L.G., S.S., J.L.B., L.E.N.), Department of Surgery (W.W., C.T.T.), Department of Medicine (L.T.), and Department of Pharmacology (T.R.K.), Yale University, New Haven, CT; Howard Hughes Medical Institute, Chevy Chase, MD (S.D., R.J.L.); Department of Chemical and Biological Engineering, Rensselaer Polytechnic Institute, Troy, NY (A.W., C.C., R.J.L.); Department of Biomedical Engineering, University of Connecticut, Storrs (D.S.); and Department of Biomedical Engineering, The City College of New York (J.M.T.).
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Haeger SM, Yang Y, Schmidt EP. Heparan Sulfate in the Developing, Healthy, and Injured Lung. Am J Respir Cell Mol Biol 2016; 55:5-11. [PMID: 26982577 PMCID: PMC4942210 DOI: 10.1165/rcmb.2016-0043tr] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2016] [Accepted: 03/11/2016] [Indexed: 11/24/2022] Open
Abstract
Remarkable progress has been achieved in understanding the regulation of gene expression and protein translation, and how aberrancies in these template-driven processes contribute to disease pathogenesis. However, much of cellular physiology is controlled by non-DNA, nonprotein mediators, such as glycans. The focus of this Translational Review is to highlight the importance of a specific glycan polymer-the glycosaminoglycan heparan sulfate (HS)-on lung health and disease. We demonstrate how HS contributes to lung physiology and pathophysiology via its actions as both a structural constituent of the lung parenchyma as well as a regulator of cellular signaling. By highlighting current uncertainties in HS biology, we identify opportunities for future high-impact pulmonary and critical care translational investigations.
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Affiliation(s)
- Sarah M. Haeger
- Department of Medicine, University of Colorado School of Medicine, Aurora, Colorado; and
| | - Yimu Yang
- Department of Medicine, University of Colorado School of Medicine, Aurora, Colorado; and
| | - Eric P. Schmidt
- Department of Medicine, University of Colorado School of Medicine, Aurora, Colorado; and
- Department of Medicine, Denver Health Medical Center, Denver, Colorado
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25
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Kang H, Fan Y, Zhao P, Ren C, Wang Z, Deng X. Regional specific modulation of the glycocalyx and smooth muscle cell contractile apparatus in conduit arteries of tail-suspended rats. J Appl Physiol (1985) 2016; 120:537-45. [DOI: 10.1152/japplphysiol.00245.2015] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2015] [Accepted: 12/16/2015] [Indexed: 11/22/2022] Open
Abstract
The glycocalyx is a key mechanosensor on the surfaces of vascular cells (endothelial cells and smooth muscle cells), and recently, we reported that the redistribution of the hemodynamic factors in tail-suspended (TS) hindlimb-unloaded rats induces the dimensional adaptation of the endothelial glycocalyx in a regional-dependent manner. In the present study, we investigated the coverage and gene expression of the glycocalyx and its possible relationship with smooth muscle contractility in the conduit arteries from the TS rats. The coverage of the glycocalyx, determined by the area analysis of the fluorescein isothiocyanate-labeled wheat germ agglutinin (WGA-FITC) staining to the cryosections of rat vessels, showed a 27.2% increase in the common carotid artery, a 13.3 and 8.0% decrease in the corresponding abdominal aorta and the femoral artery after 3 wk of tail suspension. The relative mRNA levels of syndecan-2, 3, 4, glypican-1, smooth muscle protein 22 (SM22), smoothelin (SMTN), and calponin were enhanced to 1.40, 1.53, 1.70, 1.90, 2.93, 2.30, and 5.23-fold, respectively, in the common carotid artery of the TS rat. However, both glycocalyx-related genes and smooth muscle contractile apparatus were totally or partially downregulated in the abdominal aorta and femoral artery of the TS rat. A linear positive correlation between the normalized coverage of glycocalyx and normalized mRNA levels of SM22, SMTN, and calponin exists. These results suggest the regional-dependent adaptation of the glycocalyx in simulated microgravity condition, which may affect its mechanotransduction of shear stress to regulate the contractility of the smooth muscle, finally contributing to postspaceflight orthostatic intolerance.
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Affiliation(s)
- Hongyan Kang
- Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, School of Biological Science and Medical Engineering, Beihang University, Beijing, China
| | - Yubo Fan
- Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, School of Biological Science and Medical Engineering, Beihang University, Beijing, China
| | - Ping Zhao
- Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, School of Biological Science and Medical Engineering, Beihang University, Beijing, China
| | - Changhui Ren
- Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, School of Biological Science and Medical Engineering, Beihang University, Beijing, China
| | - Zhenze Wang
- Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, School of Biological Science and Medical Engineering, Beihang University, Beijing, China
| | - Xiaoyan Deng
- Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, School of Biological Science and Medical Engineering, Beihang University, Beijing, China
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26
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Mehta D, Ravindran K, Kuebler WM. Novel regulators of endothelial barrier function. Am J Physiol Lung Cell Mol Physiol 2014; 307:L924-35. [PMID: 25381026 PMCID: PMC4269690 DOI: 10.1152/ajplung.00318.2014] [Citation(s) in RCA: 88] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2014] [Accepted: 11/05/2014] [Indexed: 12/15/2022] Open
Abstract
Endothelial barrier function is an essential and tightly regulated process that ensures proper compartmentalization of the vascular and interstitial space, while allowing for the diffusive exchange of small molecules and the controlled trafficking of macromolecules and immune cells. Failure to control endothelial barrier integrity results in excessive leakage of fluid and proteins from the vasculature that can rapidly become fatal in scenarios such as sepsis or the acute respiratory distress syndrome. Here, we highlight recent advances in our understanding on the regulation of endothelial permeability, with a specific focus on the endothelial glycocalyx and endothelial scaffolds, regulatory intracellular signaling cascades, as well as triggers and mediators that either disrupt or enhance endothelial barrier integrity, and provide our perspective as to areas of seeming controversy and knowledge gaps, respectively.
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Affiliation(s)
- Dolly Mehta
- Department of Pharmacology and Center for Lung and Vascular Biology, College of Medicine, University of Illinois at Chicago, Chicago, Illinois;
| | - Krishnan Ravindran
- Keenan Research Centre for Biomedical Science, St. Michael's Hospital, Toronto, Ontario, Canada
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27
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Kang H, Sun L, Huang Y, Wang Z, Zhao P, Fan Y, Deng X. Regional specific adaptation of the endothelial glycocalyx dimension in tail-suspended rats. Pflugers Arch 2014; 467:1291-301. [DOI: 10.1007/s00424-014-1568-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2014] [Revised: 06/10/2014] [Accepted: 06/26/2014] [Indexed: 10/25/2022]
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28
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Ebong EE, Lopez-Quintero SV, Rizzo V, Spray DC, Tarbell JM. Shear-induced endothelial NOS activation and remodeling via heparan sulfate, glypican-1, and syndecan-1. Integr Biol (Camb) 2014; 6:338-47. [PMID: 24480876 PMCID: PMC3996848 DOI: 10.1039/c3ib40199e] [Citation(s) in RCA: 155] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Mammalian epithelial cells are coated with a multifunctional surface glycocalyx (GCX). On vascular endothelial cells (EC), intact GCX is atheroprotective. It is degraded in many vascular diseases. GCX heparan sulfate (HS) is essential for healthy flow-induced EC nitric oxide (NO) release, elongation, and alignment. The HS core protein mechanisms involved in these processes are unknown. We hypothesized that the glypican-1 (GPC1) HS core protein mediates flow-induced EC NO synthase (eNOS) activation because GPC1 is anchored to caveolae where eNOS resides. We also hypothesized that the HS core protein syndecan-1 (SDC1) mediates flow-induced EC elongation and alignment because SDC1 is linked to the cytoskeleton which impacts cell shape. We tested our hypotheses by exposing EC monolayers treated with HS degrading heparinase III (HepIII), and monolayers with RNA-silenced GPC1, or SDC1, to 3 to 24 hours of physiological shear stress. Shear-conditioned EC with intact GCX exhibited characteristic eNOS activation in short-term flow conditions. After long-term exposure, EC with intact GCX were elongated and aligned in the direction of flow. HS removal and GPC1 inhibition, not SDC1 reduction, blocked shear-induced eNOS activation. EC remodeling in response to flow was attenuated by HS degradation and in the absence of SDC1, but preserved with GPC1 knockdown. These findings clearly demonstrate that HS is involved in both centralized and decentralized GCX-mediated mechanotransduction mechanisms, with GPC1 acting as a centralized mechanotransmission agent and SDC1 functioning in decentralized mechanotransmission. This foundational work demonstrates how EC can transform fluid shear forces into diverse biomolecular and biomechanical responses.
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Affiliation(s)
- Eno E Ebong
- Department of Neuroscience, Albert Einstein College of Medicine, 1300 Morris Park Ave, K-840, Bronx, NY 10461
- Department of Biomedical Engineering, City College of New York, 140 Street and Convent Avenue, T-404B, New York, NY 10031
| | - Sandra V Lopez-Quintero
- Department of Neuroscience, Albert Einstein College of Medicine, 1300 Morris Park Ave, K-840, Bronx, NY 10461
| | - Victor Rizzo
- Cardiovascular Research Center, Temple University School of Medicine, 3500 N. Broad Street, MERB 1080, Philadelphia, PA 19140
| | - David C Spray
- Department of Neuroscience, Albert Einstein College of Medicine, 1300 Morris Park Ave, K-840, Bronx, NY 10461
| | - John M Tarbell
- Department of Biomedical Engineering, City College of New York, 140 Street and Convent Avenue, T-404B, New York, NY 10031
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29
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Collins SR, Blank RS, Deatherage LS, Dull RO. Special article: the endothelial glycocalyx: emerging concepts in pulmonary edema and acute lung injury. Anesth Analg 2013; 117:664-674. [PMID: 23835455 PMCID: PMC3790575 DOI: 10.1213/ane.0b013e3182975b85] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
The endothelial glycocalyx is a dynamic layer of macromolecules at the luminal surface of vascular endothelium that is involved in fluid homeostasis and regulation. Its role in vascular permeability and edema formation is emerging but is still not well understood. In this special article, we highlight key concepts of endothelial dysfunction with regards to the glycocalyx and provide new insights into the glycocalyx as a mediator of processes central to the development of pulmonary edema and lung injury.
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Affiliation(s)
- Stephen R Collins
- From the Department of Anesthesiology, University of Virginia Health System, Charlottesville, Virginia; Department of Anesthesiology, University of Utah, Salt Lake City, Utah; and Department of Anesthesiology and Bioengineering, University of Illinois at Chicago College of Medicine, Chicago, Illinois
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30
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Giantsos-Adams KM, Koo AJA, Song S, Sakai J, Sankaran J, Shin JH, Garcia-Cardena G, Dewey CF. Heparan Sulfate Regrowth Profiles Under Laminar Shear Flow Following Enzymatic Degradation. Cell Mol Bioeng 2013; 6:160-174. [PMID: 23805169 PMCID: PMC3689914 DOI: 10.1007/s12195-013-0273-z] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2012] [Accepted: 02/07/2013] [Indexed: 11/17/2022] Open
Abstract
The local hemodynamic shear stress waveforms present in an artery dictate the endothelial cell phenotype. The observed decrease of the apical glycocalyx layer on the endothelium in atheroprone regions of the circulation suggests that the glycocalyx may have a central role in determining atherosclerotic plaque formation. However, the kinetics for the cells' ability to adapt its glycocalyx to the environment have not been quantitatively resolved. Here we report that the heparan sulfate component of the glycocalyx of HUVECs increases by 1.4-fold following the onset of high shear stress, compared to static cultured cells, with a time constant of 19 h. Cell morphology experiments show that 12 h are required for the cells to elongate, but only after 36 h have the cells reached maximal alignment to the flow vector. Our findings demonstrate that following enzymatic degradation, heparan sulfate is restored to the cell surface within 12 h under flow whereas the time required is 20 h under static conditions. We also propose a model describing the contribution of endocytosis and exocytosis to apical heparan sulfate expression. The change in HS regrowth kinetics from static to high-shear EC phenotype implies a differential in the rate of endocytic and exocytic membrane turnover.
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Affiliation(s)
- Kristina M. Giantsos-Adams
- Department of Mechanical Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Rm. 3-254, Cambridge, MA 02139 USA
- Department of Mechanical Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Rm. 3-254, Cambridge, MA 02139 USA
| | - Andrew Jia-An Koo
- Department of Biological Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA USA
| | - Sukhyun Song
- Department of Bioengineering, Korean Advanced Institute for Science and Technology, 291 Daehak-ro (373-1 Guseong-dong), Yuseong-gu, Daejeon Korea
| | - Jiro Sakai
- Department of Mechanical Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Rm. 3-254, Cambridge, MA 02139 USA
| | - Jagadish Sankaran
- National University of Singapore, E4-04-10, 4 Engineering Drive 3, Singapore, Singapore
| | - Jennifer H. Shin
- Department of Bioengineering, Korean Advanced Institute for Science and Technology, 291 Daehak-ro (373-1 Guseong-dong), Yuseong-gu, Daejeon Korea
| | - Guillermo Garcia-Cardena
- Department of Pathology, Brigham and Women’s Hospital, Harvard Medical School, 77 Avenue Louis Pasteur, Boston, MA USA
| | - C. Forbes Dewey
- Department of Mechanical Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Rm. 3-254, Cambridge, MA 02139 USA
- Department of Biological Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA USA
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31
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Glycocalyx degradation causes microvascular perfusion failure in the ex vivo perfused mouse lung: hydroxyethyl starch 130/0.4 pretreatment attenuates this response. Shock 2013; 38:559-66. [PMID: 23042196 DOI: 10.1097/shk.0b013e31826f2583] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
The endothelial glycocalyx (GLX) is pivotal to vascular barrier function. We investigated the consequences of GLX degradation on pulmonary microvascular perfusion and, prompted by evidence that hydroxyethyl starch (HES) improves microcirculation, studied the effects of two HES preparations during GLX diminution. C57 BL/6 black mice lungs were explanted and perfused with 1-mL/min buffer solution containing autologous erythrocytes (red blood cells) at a hematocrit of 5%. Microvessel perfusion was quantified by video fluorescence microscopy at 0 and 90 min. To register interstitial edema, alveolar septal width was quantified. Pulmonary artery pressure (PAP), airway pressure, and left atrial pressure were recorded continuously. Lungs were randomly assigned to four groups (each n = 5): (i) control: no treatment, (ii) HEP1: heparinase I (1 mU/mL) was injected for GLX degradation, (iii) HES 130, and (iv) HES 200: one third of perfusion fluid was exchanged for 6% HES 130/0.4 or 10% HES 200/0.5 before GLX degradation. Analysis of variance on ranks and pairwise multiple comparisons were used for statistics, P < 0.05. Compared with control, GLX degradation effected perfusion failure in microvessels, increased PAP, and facilitated interstitial edema formation after a 90-min period of perfusion. In contrast to HES 200/0.5, pretreatment with HES 130/0.4 attenuated all of these consequences. Sequelae of GLX degradation in lung include perfusion failure in microvessels, interstitial edema formation, and increase in PAP. We assume that these effects are a consequence of vascular barrier dysfunction. Beneficial effects of HES 130/0.4 are presumably a result of its lower red blood cell bridging capacity compared with HES 200/0.5.
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32
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Yang Y, Schmidt EP. The endothelial glycocalyx: an important regulator of the pulmonary vascular barrier. Tissue Barriers 2013; 1. [PMID: 24073386 PMCID: PMC3781215 DOI: 10.4161/tisb.23494] [Citation(s) in RCA: 77] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Once thought to be a structure of small size and uncertain significance, the endothelial glycocalyx is now known to be an important regulator of endothelial function. Studies of the systemic vasculature have demonstrated that the glycocalyx forms a substantial in vivo endothelial surface layer (ESL) critical to inflammation, barrier function and mechanotransduction. The pulmonary ESL is significantly thicker than the systemic ESL, suggesting unique physiologic function. We have recently demonstrated that the pulmonary ESL regulates exposure of endothelial surface adhesion molecules, thereby serving as a barrier to neutrophil adhesion and extravasation. While the pulmonary ESL is not a critical structural component of the endothelial barrier to fluid and protein, it serves a major role in the mechanotransduction of vascular pressure, with impact on the active regulation of endothelial permeability. It is likely that the ESL serves numerous additional functions in vascular physiology, representing a fertile area for future investigation.
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Affiliation(s)
- Yimu Yang
- Program in Translational Lung Research, Division of Pulmonary Sciences and Critical Care Medicine, University of Colorado School of Medicine, Aurora, Colorado
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33
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Job KM, Dull RO, Hlady V. Use of reflectance interference contrast microscopy to characterize the endothelial glycocalyx stiffness. Am J Physiol Lung Cell Mol Physiol 2012; 302:L1242-9. [PMID: 22505668 DOI: 10.1152/ajplung.00341.2011] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Reflectance interference contrast microscopy (RICM) was used to study the mechanics of the endothelial glycocalyx. This technique tracks the vertical position of a glass microsphere probe that applies very light fluctuating loads to the outermost layer of the bovine lung microvascular endothelial cell (BLMVEC) glycocalyx. Fluctuations in probe vertical position are used to estimate the effective stiffness of the underlying layer. Stiffness was measured before and after removal of specific glycocalyx components. The mean stiffness of BLMVEC glycocalyx was found to be ~7.5 kT/nm(2) (or ~31 pN/nm). Enzymatic digestion of the glycocalyx with pronase or hyaluronan with hyaluronidase increased the mean effective stiffness of the glycocalyx; however, the increase of the mean stiffness on digestion of heparan sulfate with heparinase III was not significant. The results imply that hyaluronan chains act as a cushioning layer to distribute applied forces to the glycocalyx structure. Effective stiffness was also measured for the glycocalyx exposed to 0.1%, 1.0%, and 4.0% BSA; glycocalyx compliance increased at two extreme BSA concentrations. The RICM images indicated that glycocalyx thickness increases with BSA concentrations. Results demonstrate that RICM is sensitive to detect the subtle changes of glycocalyx compliance at the fluid-fiber interface.
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Affiliation(s)
- Kathleen M Job
- Dept. of Bioengineering, Univ. of Utah, BPRB, Rm. 108A, Salt Lake City, UT 84312, USA
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34
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Dull RO, Cluff M, Kingston J, Hill D, Chen H, Hoehne S, Malleske DT, Kaur R. Lung heparan sulfates modulate K(fc) during increased vascular pressure: evidence for glycocalyx-mediated mechanotransduction. Am J Physiol Lung Cell Mol Physiol 2011; 302:L816-28. [PMID: 22160307 DOI: 10.1152/ajplung.00080.2011] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Lung endothelial cells respond to changes in vascular pressure through mechanotransduction pathways that alter barrier function via non-Starling mechanism(s). Components of the endothelial glycocalyx have been shown to participate in mechanotransduction in vitro and in systemic vessels, but the glycocalyx's role in mechanosensing and pulmonary barrier function has not been characterized. Mechanotransduction pathways may represent novel targets for therapeutic intervention during states of elevated pulmonary pressure such as acute heart failure, fluid overload, and mechanical ventilation. Our objective was to assess the effects of increasing vascular pressure on whole lung filtration coefficient (K(fc)) and characterize the role of endothelial heparan sulfates in mediating mechanotransduction and associated increases in K(fc). Isolated perfused rat lung preparation was used to measure K(fc) in response to changes in vascular pressure in combination with superimposed changes in airway pressure. The roles of heparan sulfates, nitric oxide, and reactive oxygen species were investigated. Increases in capillary pressure altered K(fc) in a nonlinear relationship, suggesting non-Starling mechanism(s). nitro-l-arginine methyl ester and heparanase III attenuated the effects of increased capillary pressure on K(fc), demonstrating active mechanotransduction leading to barrier dysfunction. The nitric oxide (NO) donor S-nitrosoglutathione exacerbated pressure-mediated increase in K(fc). Ventilation strategies altered lung NO concentration and the K(fc) response to increases in vascular pressure. This is the first study to demonstrate a role for the glycocalyx in whole lung mechanotransduction and has important implications in understanding the regulation of vascular permeability in the context of vascular pressure, fluid status, and ventilation strategies.
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Affiliation(s)
- Randal O Dull
- Department of Anesthesiology, Lung Vascular Biology Laboratory, University of Utah School of Medicine, Salt Lake City, UT 84132-2304, USA.
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O'Callaghan R, Job KM, Dull RO, Hlady V. Stiffness and heterogeneity of the pulmonary endothelial glycocalyx measured by atomic force microscopy. Am J Physiol Lung Cell Mol Physiol 2011; 301:L353-60. [PMID: 21705487 DOI: 10.1152/ajplung.00342.2010] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The mechanical properties of endothelial glycocalyx were studied using atomic force microscopy with a silica bead (diameter ∼18 μm) serving as an indenter. Even at indentations of several hundred nanometers, the bead exerted very low compressive pressures on the bovine lung microvascular endothelial cell (BLMVEC) glycocalyx and allowed for an averaging of stiffness in the bead-cell contact area. The elastic modulus of BLMVEC glycocalyx was determined as a pointwise function of the indentation depth before and after enzymatic degradation of specific glycocalyx components. The modulus-indentation depth profiles showed the cells becoming progressively stiffer with increased indentation. Three different enzymes were used: heparinases III and I and hyaluronidase. The main effects of heparinase III and hyaluronidase enzymes were that the elastic modulus in the cell junction regions increased more rapidly with the indentation than in BLMVEC controls, and that the effective thickness of glycocalyx was reduced. Cytochalasin D abolished the modulus increase with the indentation. The confocal profiling of heparan sulfate and hyaluronan with atomic force microscopy indentation data demonstrated marked heterogeneity of the glycocalyx composition between cell junctions and nuclear regions.
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Affiliation(s)
- Ryan O'Callaghan
- 20 S. 2030 E., Rm. 108A, Dept. of Bioengineering, Univ. of Utah, Salt Lake City, UT 84112, USA
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Mechano-transduction and barrier regulation in lung microvascular endothelial cells. Methods Mol Biol 2011; 763:291-301. [PMID: 21874460 DOI: 10.1007/978-1-61779-191-8_20] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Alterations in endothelial permeability are a hallmark of inflammation as well as the underlying cause of many clinical syndromes. Quantifying changes in endothelial barrier properties to water and macromolecules can be an important means of assessing the degree of cellular injury and, conversely, the effect of therapies to attenuate the inflammatory cascade. We use a combination of an isolated organ system and two cell culture models to investigate mechanisms of endothelial barrier regulation under variety of experimental conditions. Each assay has its own experimental strengths and limitations and must be used appropriately for the questions being asked. When used collectively, they can provide significant insight into the molecular regulation of lung endothelial permeability.
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A model of giant vacuole dynamics in human Schlemm's canal endothelial cells. Exp Eye Res 2010; 92:57-66. [PMID: 21075103 DOI: 10.1016/j.exer.2010.11.003] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2010] [Revised: 10/01/2010] [Accepted: 11/02/2010] [Indexed: 10/18/2022]
Abstract
Aqueous humour transport across the inner wall endothelium of Schlemm's canal likely involves flow through giant vacuoles and pores, but the mechanics of how these structures form and how they influence the regulation of intraocular pressure (IOP) are not well understood. In this study, we developed an in vitro model of giant vacuole formation in human Schlemm's canal endothelial cells (HSCECs) perfused in the basal-to-apical direction (i.e., the direction that flow crosses the inner wall in vivo) under controlled pressure drops (2 or 6 mmHg). The system was mounted on a confocal microscope for time-lapse en face imaging, and cells were stained with calcein, a fluorescent vital dye. At the onset of perfusion, elliptical void regions appeared within an otherwise uniformly stained cytoplasm, and 3-dimensional reconstructions revealed that these voids were dome-like outpouchings of the cell to form giant vacuole-like structures or GVLs that reproduced the classic "signet ring" appearance of true giant vacuoles. Increasing pressure drop from 2 to 6 mmHg increased GVL height (14 ± 4 vs. 21 ± 7 μm, p < 0.0001) and endothelial hydraulic conductivity (1.15 ± 0.04 vs. 2.11 ± 0.49 μl min⁻¹ mmHg⁻¹ cm⁻²; p < 0.001), but there was significant variability in the GVL response to pressure between cell lines isolated from different donors. During perfusion, GVLs were observed "migrating" and agglomerating about the cell layer and often collapsed despite maintaining the same pressure drop. GVL formation was also observed in human umbilical vein and porcine aortic endothelial cells, suggesting that giant vacuole formation is not a unique property of Schlemm's canal cells. However, in these other cell types, GVLs were rarely observed "migrating" or contracting during perfusion, suggesting that Schlemm's canal endothelial cells may be better adapted to withstand basal-to-apical directed pressure gradients. In conclusion, we have established an in vitro model system to study giant vacuole dynamics, and we have demonstrated that this system reproduces key aspects of giant vacuole morphology and behaviour. This model offers promising opportunities to investigate the role of endothelial cell biomechanics in the regulation of intraocular pressure in normal and glaucomatous eyes.
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Giantsos-Adams K, Lopez-Quintero V, Kopeckova P, Kopecek J, Tarbell JM, Dull R. Study of the therapeutic benefit of cationic copolymer administration to vascular endothelium under mechanical stress. Biomaterials 2010; 32:288-94. [PMID: 20932573 DOI: 10.1016/j.biomaterials.2010.08.092] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2010] [Accepted: 08/27/2010] [Indexed: 11/28/2022]
Abstract
Pulmonary edema and the associated increases in vascular permeability continue to represent a significant clinical problem in the intensive care setting, with no current treatment modality other than supportive care and mechanical ventilation. Therapeutic compound(s) capable of attenuating changes in vascular barrier function would represent a significant advance in critical care medicine. We have previously reported the development of HPMA-based copolymers, targeted to endothelial glycocalyx that are able to enhance barrier function. In this work, we report the refinement of copolymer design and extend our physiological studies to demonstrate that the polymers: 1) reduce both shear stress and pressure-mediated increase in hydraulic conductivity, 2) reduce nitric oxide production in response to elevated hydrostatic pressure and, 3) reduce the capillary filtration coefficient (K(fc)) in an isolated perfused mouse lung model. These copolymers represent an important tool for use in mechanotransduction research and a novel strategy for developing clinically useful copolymers for the treatment of vascular permeability.
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Affiliation(s)
- Kristina Giantsos-Adams
- Department of Anesthesiology, University of Utah, School of Medicine, Salt Lake City, UT 84312, USA
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Becker BF, Chappell D, Jacob M. Endothelial glycocalyx and coronary vascular permeability: the fringe benefit. Basic Res Cardiol 2010; 105:687-701. [DOI: 10.1007/s00395-010-0118-z] [Citation(s) in RCA: 191] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/17/2010] [Revised: 08/25/2010] [Accepted: 08/26/2010] [Indexed: 12/11/2022]
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Abstract
The shear stress of flowing blood on the surfaces of endothelial cells that provide the barrier to transport of solutes and water between blood and the underlying tissue modulates the permeability to solutes and the hydraulic conductivity. This review begins with a discussion of transport pathways across the endothelium and then considers the experimental evidence from both in vivo and in vitro studies that shows an influence of shear stress on endothelial transport properties after both acute (minutes to hours) and chronic (hours to days) changes in shear stress. Next, the effects of shear stress on individual transport pathways (tight junctions, adherens junctions, vesicles and leaky junctions) are described, and this information is integrated with the transport experiments to suggest mechanisms controlling both acute and chronic responses of transport properties to shear stress. The review ends with a summary of future research challenges.
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Affiliation(s)
- John M Tarbell
- Department of Biomedical Engineering, The City College of New York, Convent Avenue at 140th Street, New York, NY 10031, USA
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Scallan J, Huxley VH, Korthuis RJ. Capillary Fluid Exchange: Regulation, Functions, and Pathology. ACTA ACUST UNITED AC 2010. [DOI: 10.4199/c00006ed1v01y201002isp003] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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Giantsos KM, Kopeckova P, Dull RO. The use of an endothelium-targeted cationic copolymer to enhance the barrier function of lung capillary endothelial monolayers. Biomaterials 2009; 30:5885-91. [PMID: 19615737 DOI: 10.1016/j.biomaterials.2009.06.048] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2009] [Accepted: 06/19/2009] [Indexed: 10/20/2022]
Abstract
Acute changes in lung capillary permeability continue to complicate procedures such as cardiopulmonary bypass, solid organ transplant, and major vascular surgery and precipitate the more severe disease state Adult Respiratory Distress Syndrome (ARDS). To date there is no treatment targeted directly to the lung microvasculature. We hypothesized that biomimetic polymers could be used to enhance passive barrier function by reducing the porosity of the endothelial glycocalyx and attenuate mechanotransduction by restricting the motion of the glycoproteins implicated in signal transduction. To this end, cationic copolymers containing methacrylamidopropyl trimethylammonium chloride (P-TMA Cl) have been developed as an infusible therapy to target the lung capillary glycocalyx in order to mechanically enhance the capillary barrier and turn off pressure-induced mechanotransduction. Copolymers were tested for functional efficacy by measuring both albumin permeability (P(DA)) and hydraulic conductivity (L(p)) across cultured endothelial monolayers. P-TMA Cl significantly decreased P(DA) in normal and inflamed cells and attenuated pressure-induced increases in L(p). Decreases in L(p) across endothelial monolayers in the presence of P-TMA Cl is evidence of a dampening of mechanotransduction-induced barrier dysfunction. We show the potential for biomimetic polymers targeted to lung endothelium as a viable therapy to enhance endothelial barrier function thereby attenuating a major component of vascular inflammation.
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Affiliation(s)
- Kristina M Giantsos
- Department of Pharmaceutics and Pharmaceutical Chemistry, University of Utah, Salt Lake City, UT 84112, USA
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Balligand JL, Feron O, Dessy C. eNOS activation by physical forces: from short-term regulation of contraction to chronic remodeling of cardiovascular tissues. Physiol Rev 2009; 89:481-534. [PMID: 19342613 DOI: 10.1152/physrev.00042.2007] [Citation(s) in RCA: 315] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Nitric oxide production in response to flow-dependent shear forces applied on the surface of endothelial cells is a fundamental mechanism of regulation of vascular tone, peripheral resistance, and tissue perfusion. This implicates the concerted action of multiple upstream "mechanosensing" molecules reversibly assembled in signalosomes recruiting endothelial nitric oxide synthase (eNOS) in specific subcellular locales, e.g., plasmalemmal caveolae. Subsequent short- and long-term increases in activity and expression of eNOS translate this mechanical stimulus into enhanced NO production and bioactivity through a complex transcriptional and posttranslational regulation of the enzyme, including by shear-stress responsive transcription factors, oxidant stress-dependent regulation of transcript stability, eNOS regulatory phosphorylations, and protein-protein interactions. Notably, eNOS expressed in cardiac myocytes is amenable to a similar regulation in response to stretching of cardiac muscle cells and in part mediates the length-dependent increase in cardiac contraction force. In addition to short-term regulation of contractile tone, eNOS mediates key aspects of cardiac and vascular remodeling, e.g., by orchestrating the mobilization, recruitment, migration, and differentiation of cardiac and vascular progenitor cells, in part by regulating the stabilization and transcriptional activity of hypoxia inducible factor in normoxia and hypoxia. The continuum of the influence of eNOS in cardiovascular biology explains its growing implication in mechanosensitive aspects of integrated physiology, such as the control of blood pressure variability or the modulation of cardiac remodeling in situations of hemodynamic overload.
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Affiliation(s)
- J-L Balligand
- Unit of Pharmacology and Therapeutics, Université catholique de Louvain, Brussels, Belgium.
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Lopez-Quintero SV, Amaya R, Pahakis M, Tarbell JM. The endothelial glycocalyx mediates shear-induced changes in hydraulic conductivity. Am J Physiol Heart Circ Physiol 2009; 296:H1451-6. [PMID: 19286951 DOI: 10.1152/ajpheart.00894.2008] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Recent in vitro and in vivo studies have reported fluid shear stress-induced increases in endothelial layer hydraulic conductivity (L(p)) that are mediated by an increased production of nitric oxide (NO). Other recent studies have shown that NO induction by shear stress is mediated by the glycocalyx that decorates the surface of endothelial cells. Here we find that a selective depletion of the major components of the glycocalyx with enzymes can block the shear stress-induced response of L(p). Heparinase and hyaluronidase block shear-induced increases in L(p), which is consistent with their effects on NO production. But chondroitinase, which does not suppress shear-induced NO production, also inhibits shear-induced L(p). A further surprise is that treatment with the general proteolytic enzyme pronase does not suppress the shear L(p) response. We also find that heparinase does not alter baseline L(p) significantly, whereas chondroitinase, hyaluronidase, and pronase increase it significantly.
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Affiliation(s)
- Sandra V Lopez-Quintero
- Dept. of Biomedical Engineering, The City College of the City Univ. of New York, Steinman Hall, Rm. T403, 140th St. and Convent Ave., New York, NY 10031, USA
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Vandenbroucke E, Mehta D, Minshall R, Malik AB. Regulation of endothelial junctional permeability. Ann N Y Acad Sci 2008; 1123:134-45. [PMID: 18375586 DOI: 10.1196/annals.1420.016] [Citation(s) in RCA: 432] [Impact Index Per Article: 27.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
The endothelium is a semi-permeable barrier that regulates the flux of liquid and solutes, including plasma proteins, between the blood and surrounding tissue. The permeability of the vascular barrier can be modified in response to specific stimuli acting on endothelial cells. Transport across the endothelium can occur via two different pathways: through the endothelial cell (transcellular) or between adjacent cells, through interendothelial junctions (paracellular). This review focuses on the regulation of the paracellular pathway. The paracellular pathway is composed of adhesive junctions between endothelial cells, both tight junctions and adherens junctions. The actin cytoskeleton is bound to each junction and controls the integrity of each through actin remodeling. These interendothelial junctions can be disassembled or assembled to either increase or decrease paracellular permeability. Mediators, such as thrombin, TNF-alpha, and LPS, stimulate their respective receptor on endothelial cells to initiate signaling that increases cytosolic Ca2+ and activates myosin light chain kinase (MLCK), as well as monomeric GTPases RhoA, Rac1, and Cdc42. Ca2+ activation of MLCK and RhoA disrupts junctions, whereas Rac1 and Cdc42 promote junctional assembly. Increased endothelial permeability can be reversed with "barrier stabilizing agents," such as sphingosine-1-phosphate and cyclic adenosine monophosphate (cAMP). This review provides an overview of the mechanisms that regulate paracellular permeability.
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Affiliation(s)
- Emily Vandenbroucke
- Department of Pharmacology and Center for Lung and Vascular Biology, The University of Illonois College of Medicine, Chicago, IL 60612, USA
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Pournaras CJ, Rungger-Brändle E, Riva CE, Hardarson SH, Stefansson E. Regulation of retinal blood flow in health and disease. Prog Retin Eye Res 2008; 27:284-330. [PMID: 18448380 DOI: 10.1016/j.preteyeres.2008.02.002] [Citation(s) in RCA: 387] [Impact Index Per Article: 24.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Optimal retinal neuronal cell function requires an appropriate, tightly regulated environment, provided by cellular barriers, which separate functional compartments, maintain their homeostasis, and control metabolic substrate transport. Correctly regulated hemodynamics and delivery of oxygen and metabolic substrates, as well as intact blood-retinal barriers are necessary requirements for the maintenance of retinal structure and function. Retinal blood flow is autoregulated by the interaction of myogenic and metabolic mechanisms through the release of vasoactive substances by the vascular endothelium and retinal tissue surrounding the arteriolar wall. Autoregulation is achieved by adaptation of the vascular tone of the resistance vessels (arterioles, capillaries) to changes in the perfusion pressure or metabolic needs of the tissue. This adaptation occurs through the interaction of multiple mechanisms affecting the arteriolar smooth muscle cells and capillary pericytes. Mechanical stretch and increases in arteriolar transmural pressure induce the endothelial cells to release contracting factors affecting the tone of arteriolar smooth muscle cells and pericytes. Close interaction between nitric oxide (NO), lactate, arachidonic acid metabolites, released by the neuronal and glial cells during neural activity and energy-generating reactions of the retina strive to optimize blood flow according to the metabolic needs of the tissue. NO, which plays a central role in neurovascular coupling, may exert its effect, by modulating glial cell function involved in such vasomotor responses. During the evolution of ischemic microangiopathies, impairment of structure and function of the retinal neural tissue and endothelium affect the interaction of these metabolic pathways, leading to a disturbed blood flow regulation. The resulting ischemia, tissue hypoxia and alterations in the blood barrier trigger the formation of macular edema and neovascularization. Hypoxia-related VEGF expression correlates with the formation of neovessels. The relief from hypoxia results in arteriolar constriction, decreases the hydrostatic pressure in the capillaries and venules, and relieves endothelial stretching. The reestablished oxygenation of the inner retina downregulates VEGF expression and thus inhibits neovascularization and macular edema. Correct control of the multiple pathways, such as retinal blood flow, tissue oxygenation and metabolic substrate support, aiming at restoring retinal cell metabolic interactions, may be effective in preventing damage occurring during the evolution of ischemic microangiopathies.
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Affiliation(s)
- Constantin J Pournaras
- Department of Ophthalmology, Vitreo-Retina Unit, University Hospitals of Geneva, 22 rue Alcide Jentzer, CH-1211 Geneva 14, Switzerland.
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Burns AR, Zheng Z, Soubra SH, Chen J, Rumbaut RE. Transendothelial flow inhibits neutrophil transmigration through a nitric oxide-dependent mechanism: potential role for cleft shear stress. Am J Physiol Heart Circ Physiol 2007; 293:H2904-10. [PMID: 17720767 DOI: 10.1152/ajpheart.00871.2007] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Endothelial cells in vivo are well known to respond to parallel shear stress induced by luminal blood flow. In addition, fluid filtration across endothelium (transendothelial flow) may trigger nitric oxide (NO) production, presumably via shear stress within intercellular clefts. Since NO regulates neutrophil-endothelial interactions, we determined whether transendothelial flow regulates neutrophil transmigration. Interleukin-1β-treated human umbilical vein endothelial cell (HUVEC) monolayers cultured on a polycarbonate filter were placed in a custom chamber with or without a modest hydrostatic pressure gradient (ΔP, 10 cmH2O) to induce transendothelial flow. In other experiments, cells were studied in a parallel plate flow chamber at various transendothelial flows (ΔP = 0, 5, and 10 cmH2O) and luminal flows (shear stress of 0, 1, and 2 dyn/cm2). In the absence of luminal flow, transendothelial flow reduced transmigration of freshly isolated human neutrophils from 57% to 14% ( P < 0.05) and induced an increase in NO detected with a fluorescent assay (DAF-2DA). The NO synthase inhibitor l-NAME prevented the effects of transendothelial flow on neutrophil transmigration, while a NO donor (DETA/NO, 1 mM) inhibited neutrophil transmigration. Finally, in the presence of luminal flow (1 and 2 dyn/cm2), transendothelial flow also inhibited transmigration. On the basis of HUVEC morphometry and measured transendothelial volume flow, we estimated cleft shear stress to range from 49 to 198 dyn/cm2. These shear stress estimates, while substantial, are of similar magnitude to those reported by others with similar analyses. These data are consistent with the hypothesis that endothelial cleft shear stress inhibits neutrophil transmigration via a NO-dependent mechanism.
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Affiliation(s)
- Alan R Burns
- Department of Medicine, Baylor College of Medicine, Houston, TX 77030, USA
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