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Königstein K, Dipla K, Zafeiridis A. Training the Vessels: Molecular and Clinical Effects of Exercise on Vascular Health-A Narrative Review. Cells 2023; 12:2544. [PMID: 37947622 PMCID: PMC10649652 DOI: 10.3390/cells12212544] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2023] [Revised: 10/27/2023] [Accepted: 10/28/2023] [Indexed: 11/12/2023] Open
Abstract
Accelerated biological vascular ageing is still a major driver of the increasing burden of cardiovascular disease and mortality. Exercise training delays this process, known as early vascular ageing, but often lacks effectiveness due to a lack of understanding of molecular and clinical adaptations to specific stimuli. This narrative review summarizes the current knowledge about the molecular and clinical vascular adaptations to acute and chronic exercise. It further addresses how training characteristics (frequency, intensity, volume, and type) may influence these processes. Finally, practical recommendations are given for exercise training to maintain and improve vascular health. Exercise increases shear stress on the vascular wall and stimulates the endothelial release of circulating growth factors and of exerkines from the skeletal muscle and other organs. As a result, remodeling within the vascular walls leads to a better vasodilator and -constrictor responsiveness, reduced arterial stiffness, arterio- and angiogenesis, higher antioxidative capacities, and reduced oxidative stress. Although current evidence about specific aspects of exercise training, such as F-I-T-T, is limited, and exact training recommendations cannot be given, some practical implications can be extracted. As such, repeated stimuli 5-7 days per week might be necessary to use the full potential of these favorable physiological alterations, and the cumulative volume of mechanical shear stress seems more important than peak shear stress. Because of distinct short- and long-term effects of resistance and aerobic exercise, including higher and moderate intensities, both types of exercise should be implemented in a comprehensive training regimen. As vascular adaptability towards exercise remains high at any age in both healthy individuals and patients with cardiovascular diseases, individualized exercise-based vascular health prevention should be implemented in any age group from children to centenarians.
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Affiliation(s)
- Karsten Königstein
- Department of Sport, Exercise and Health, Division Sports and Exercise Medicine, University of Basel, 4052 Basel, Switzerland
| | - Konstantina Dipla
- Laboratory of Exercise Physiology and Biochemistry, Department of Physical Education and Sports Science at Serres, Aristotle University of Thessaloniki, 62100 Serres, Greece;
| | - Andreas Zafeiridis
- Laboratory of Exercise Physiology and Biochemistry, Department of Physical Education and Sports Science at Serres, Aristotle University of Thessaloniki, 62100 Serres, Greece;
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2
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Na JT, Chun-Dong Xue, Wang YX, Li YJ, Wang Y, Liu B, Qin KR. Fabricating a multi-component microfluidic system for exercise-induced endothelial cell mechanobiology guided by hemodynamic similarity. Talanta 2023; 253:123933. [PMID: 36113333 DOI: 10.1016/j.talanta.2022.123933] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2022] [Revised: 09/07/2022] [Accepted: 09/08/2022] [Indexed: 12/13/2022]
Abstract
Generating precise in vivo arterial endothelial hemodynamic microenvironments using microfluidics is essential for exploring endothelial mechanobiology. However, a hemodynamic principle guiding the fabrication of microfluidic systems is still lacking. We propose a hemodynamic similarity principle for quickly obtaining the input impedance of the microfluidic system in vitro derived from that of the arterial system in vivo to precisely generate the desired endothelial hemodynamic microenvironments. First, based on the equivalent of blood pressure (BP) and wall shear stress (WSS) waveforms, we establish a hemodynamic similarity principle to efficiently map the input impedance in vivo to that in vitro, after which the multi-component microfluidic system is designed and fabricated using a lumped parameter hemodynamic model. Second, numerical simulation and experimental studies are carried out to validate the performance of the designed microfluidic system. Finally, the intracellular Ca2+ responses after exposure to different intensities of exercise-induced BP and WSS waveforms are measured to improve the reliability of EC mechanobiological studies using the designed microfluidic system. Overall, the proposed hemodynamic similarity principle can guide the fabrication of a multi-component microfluidic system for endothelial cell mechanobiology.
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Affiliation(s)
- Jing-Tong Na
- School of Biomedical Engineering, Faculty of Medicine, Dalian University of Technology, Dalian 116024, China
| | - Chun-Dong Xue
- School of Optoelectronic Engineering and Instrumentation Science, Dalian University of Technology, Dalian 116024, China
| | - Yan-Xia Wang
- School of Rehabilitation Medicine, Weifang Medical University, Weifang 261053, China
| | - Yong-Jiang Li
- School of Optoelectronic Engineering and Instrumentation Science, Dalian University of Technology, Dalian 116024, China
| | - Yu Wang
- School of Optoelectronic Engineering and Instrumentation Science, Dalian University of Technology, Dalian 116024, China
| | - Bo Liu
- School of Biomedical Engineering, Faculty of Medicine, Dalian University of Technology, Dalian 116024, China
| | - Kai-Rong Qin
- School of Biomedical Engineering, Faculty of Medicine, Dalian University of Technology, Dalian 116024, China; School of Optoelectronic Engineering and Instrumentation Science, Dalian University of Technology, Dalian 116024, China.
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3
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Weaver SRC, Rendeiro C, Lucas RAI, Cable NT, Nightingale TE, McGettrick HM, Lucas SJE. Non-pharmacological interventions for vascular health and the role of the endothelium. Eur J Appl Physiol 2022. [PMID: 36149520 DOI: 10.1007/s00421-022-05041-y.pmid:36149520;pmcid:pmc9613570] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/26/2023]
Abstract
The most common non-pharmacological intervention for both peripheral and cerebral vascular health is regular physical activity (e.g., exercise training), which improves function across a range of exercise intensities and modalities. Numerous non-exercising approaches have also been suggested to improved vascular function, including repeated ischemic preconditioning (IPC); heat therapy such as hot water bathing and sauna; and pneumatic compression. Chronic adaptive responses have been observed across a number of these approaches, yet the precise mechanisms that underlie these effects in humans are not fully understood. Acute increases in blood flow and circulating signalling factors that induce responses in endothelial function are likely to be key moderators driving these adaptations. While the impact on circulating factors and environmental mechanisms for adaptation may vary between approaches, in essence, they all centre around acutely elevating blood flow throughout the circulation and stimulating improved endothelium-dependent vascular function and ultimately vascular health. Here, we review our current understanding of the mechanisms driving endothelial adaptation to repeated exposure to elevated blood flow, and the interplay between this response and changes in circulating factors. In addition, we will consider the limitations in our current knowledge base and how these may be best addressed through the selection of more physiologically relevant experimental models and research. Ultimately, improving our understanding of the unique impact that non-pharmacological interventions have on the vasculature will allow us to develop superior strategies to tackle declining vascular function across the lifespan, prevent avoidable vascular-related disease, and alleviate dependency on drug-based interventions.
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Affiliation(s)
- Samuel R C Weaver
- School of Sport, Exercise and Rehabilitation Sciences, College of Life and Environmental Sciences, University of Birmingham, Birmingham, UK.
- Centre for Human Brain Health, University of Birmingham, Birmingham, UK.
| | - Catarina Rendeiro
- School of Sport, Exercise and Rehabilitation Sciences, College of Life and Environmental Sciences, University of Birmingham, Birmingham, UK
- Centre for Human Brain Health, University of Birmingham, Birmingham, UK
| | - Rebekah A I Lucas
- School of Sport, Exercise and Rehabilitation Sciences, College of Life and Environmental Sciences, University of Birmingham, Birmingham, UK
| | - N Timothy Cable
- Institute of Sport, Manchester Metropolitan University, Manchester, UK
| | - Tom E Nightingale
- School of Sport, Exercise and Rehabilitation Sciences, College of Life and Environmental Sciences, University of Birmingham, Birmingham, UK
| | - Helen M McGettrick
- Institute of Inflammation and Ageing, College of Medical and Dental Sciences, University of Birmingham, Birmingham, UK
| | - Samuel J E Lucas
- School of Sport, Exercise and Rehabilitation Sciences, College of Life and Environmental Sciences, University of Birmingham, Birmingham, UK
- Centre for Human Brain Health, University of Birmingham, Birmingham, UK
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4
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Adams JA, Uryash A, Lopez JR. Non-Invasive Pulsatile Shear Stress Modifies Endothelial Activation; A Narrative Review. Biomedicines 2022; 10:biomedicines10123050. [PMID: 36551807 PMCID: PMC9775985 DOI: 10.3390/biomedicines10123050] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2022] [Revised: 11/18/2022] [Accepted: 11/21/2022] [Indexed: 11/29/2022] Open
Abstract
The monolayer of cells that line both the heart and the entire vasculature is the endothelial cell (EC). These cells respond to external and internal signals, producing a wide array of primary or secondary messengers involved in coagulation, vascular tone, inflammation, and cell-to-cell signaling. Endothelial cell activation is the process by which EC changes from a quiescent cell phenotype, which maintains cellular integrity, antithrombotic, and anti-inflammatory properties, to a phenotype that is prothrombotic, pro-inflammatory, and permeable, in addition to repair and leukocyte trafficking at the site of injury or infection. Pathological activation of EC leads to increased vascular permeability, thrombosis, and an uncontrolled inflammatory response that leads to endothelial dysfunction. This pathological activation can be observed during ischemia reperfusion injury (IRI) and sepsis. Shear stress (SS) and pulsatile shear stress (PSS) are produced by mechanical frictional forces of blood flow and contraction of the heart, respectively, and are well-known mechanical signals that affect EC function, morphology, and gene expression. PSS promotes EC homeostasis and cardiovascular health. The archetype of inducing PSS is exercise (i.e., jogging, which introduces pulsations to the body as a function of the foot striking the pavement), or mechanical devices which induce external pulsations to the body (Enhanced External Pulsation (EECP), Whole-body vibration (WBV), and Whole-body periodic acceleration (WBPA aka pGz)). The purpose of this narrative review is to focus on the aforementioned noninvasive methods to increase PSS, review how each of these modify specific diseases that have been shown to induce endothelial activation and microcirculatory dysfunction (Ischemia reperfusion injury-myocardial infarction and cardiac arrest and resuscitation), sepsis, and lipopolysaccharide-induced sepsis syndrome (LPS)), and review current evidence and insight into how each may modify endothelial activation and how these may be beneficial in the acute and chronic setting of endothelial activation and microvascular dysfunction.
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Affiliation(s)
- Jose A. Adams
- Division of Neonatology, Mount Sinai Medical Center, Miami Beach, FL 33140, USA
- Correspondence:
| | - Arkady Uryash
- Division of Neonatology, Mount Sinai Medical Center, Miami Beach, FL 33140, USA
| | - Jose R. Lopez
- Department of Research, Mount Sinai Medical Center, Miami Beach, FL 33140, USA
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Weaver SRC, Rendeiro C, Lucas RAI, Cable NT, Nightingale TE, McGettrick HM, Lucas SJE. Non-pharmacological interventions for vascular health and the role of the endothelium. Eur J Appl Physiol 2022; 122:2493-2514. [PMID: 36149520 PMCID: PMC9613570 DOI: 10.1007/s00421-022-05041-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2022] [Accepted: 09/05/2022] [Indexed: 12/11/2022]
Abstract
The most common non-pharmacological intervention for both peripheral and cerebral vascular health is regular physical activity (e.g., exercise training), which improves function across a range of exercise intensities and modalities. Numerous non-exercising approaches have also been suggested to improved vascular function, including repeated ischemic preconditioning (IPC); heat therapy such as hot water bathing and sauna; and pneumatic compression. Chronic adaptive responses have been observed across a number of these approaches, yet the precise mechanisms that underlie these effects in humans are not fully understood. Acute increases in blood flow and circulating signalling factors that induce responses in endothelial function are likely to be key moderators driving these adaptations. While the impact on circulating factors and environmental mechanisms for adaptation may vary between approaches, in essence, they all centre around acutely elevating blood flow throughout the circulation and stimulating improved endothelium-dependent vascular function and ultimately vascular health. Here, we review our current understanding of the mechanisms driving endothelial adaptation to repeated exposure to elevated blood flow, and the interplay between this response and changes in circulating factors. In addition, we will consider the limitations in our current knowledge base and how these may be best addressed through the selection of more physiologically relevant experimental models and research. Ultimately, improving our understanding of the unique impact that non-pharmacological interventions have on the vasculature will allow us to develop superior strategies to tackle declining vascular function across the lifespan, prevent avoidable vascular-related disease, and alleviate dependency on drug-based interventions.
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Affiliation(s)
- Samuel R C Weaver
- School of Sport, Exercise and Rehabilitation Sciences, College of Life and Environmental Sciences, University of Birmingham, Birmingham, UK.
- Centre for Human Brain Health, University of Birmingham, Birmingham, UK.
| | - Catarina Rendeiro
- School of Sport, Exercise and Rehabilitation Sciences, College of Life and Environmental Sciences, University of Birmingham, Birmingham, UK
- Centre for Human Brain Health, University of Birmingham, Birmingham, UK
| | - Rebekah A I Lucas
- School of Sport, Exercise and Rehabilitation Sciences, College of Life and Environmental Sciences, University of Birmingham, Birmingham, UK
| | - N Timothy Cable
- Institute of Sport, Manchester Metropolitan University, Manchester, UK
| | - Tom E Nightingale
- School of Sport, Exercise and Rehabilitation Sciences, College of Life and Environmental Sciences, University of Birmingham, Birmingham, UK
| | - Helen M McGettrick
- Institute of Inflammation and Ageing, College of Medical and Dental Sciences, University of Birmingham, Birmingham, UK
| | - Samuel J E Lucas
- School of Sport, Exercise and Rehabilitation Sciences, College of Life and Environmental Sciences, University of Birmingham, Birmingham, UK
- Centre for Human Brain Health, University of Birmingham, Birmingham, UK
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Hemingway HW, Richey RE, Moore AM, Shokraeifard AM, Thomas GC, Olivencia-Yurvati AH, Romero SA. Shear stress induced by acute heat exposure is not obligatory to protect against endothelial ischemia-reperfusion injury in humans. J Appl Physiol (1985) 2022; 132:199-208. [PMID: 34941435 PMCID: PMC8759960 DOI: 10.1152/japplphysiol.00748.2021] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Acute heat exposure protects against endothelial ischemia-reperfusion (I/R) injury in humans. However, the mechanism/s mediating this protective effect remain unclear. We tested the hypothesis that inhibiting the increase in shear stress induced by acute heat exposure would attenuate the protection of endothelial function following I/R injury. Nine (3 women) young healthy participants were studied under three experimental conditions: 1) thermoneutral control; 2) whole body heat exposure to increase body core temperature by 1.2°C; and 3) heat exposure + brachial artery compression to inhibit the temperature-dependent increase in shear stress. Endothelial function was assessed via brachial artery flow-mediated dilatation before (pre-I/R) and after (post-I/R) 20 min of arm ischemia followed by 20 min of reperfusion. Brachial artery shear rate was increased during heat exposure (681 ± 359 s-1), but not for thermoneutral control (140 ± 63 s-1; P < 0.01 vs. heat exposure) nor for heat + brachial artery compression (139 ± 60 s-1; P < 0.01 vs. heat exposure). Ischemia-reperfusion injury reduced flow-mediated dilatation following thermoneutral control (pre-I/R, 5.5 ± 2.9% vs. post-I/R, 3.8 ± 2.9%; P = 0.06), but was protected following heat exposure (pre-I/R, 5.8 ± 2.9% vs. post-I/R, 6.1 ± 2.9%; P = 0.5) and heat + arterial compression (pre-I/R, 4.4 ± 2.8% vs. post-I/R, 5.8 ± 2.8%; P = 0.1). Contrary to our hypothesis, our findings demonstrate that shear stress induced by acute heat exposure is not obligatory to protect against endothelial I/R injury in humans.NEW & NOTEWORTHY Acute heat exposure protects against endothelial ischemia-reperfusion injury in humans. However, the mechanism/s mediating this protective effect remain unclear. We utilized arterial compression to inhibit the temperature-dependent increase in brachial artery blood velocity that occurs during acute heat exposure to isolate the contribution of shear stress to the protection of endothelial function following ischemia-reperfusion injury. Our findings demonstrate that shear stress induced by acute heat exposure is not obligatory to protect against endothelial I/R injury.
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Affiliation(s)
- Holden W. Hemingway
- 1Human Vascular Physiology Laboratory, Department of Physiology and Anatomy, University of North Texas Health Science Center, Fort Worth, Texas
| | - Rauchelle E. Richey
- 1Human Vascular Physiology Laboratory, Department of Physiology and Anatomy, University of North Texas Health Science Center, Fort Worth, Texas
| | - Amy M. Moore
- 1Human Vascular Physiology Laboratory, Department of Physiology and Anatomy, University of North Texas Health Science Center, Fort Worth, Texas
| | - Austin M. Shokraeifard
- 1Human Vascular Physiology Laboratory, Department of Physiology and Anatomy, University of North Texas Health Science Center, Fort Worth, Texas
| | - Gabriel C. Thomas
- 1Human Vascular Physiology Laboratory, Department of Physiology and Anatomy, University of North Texas Health Science Center, Fort Worth, Texas
| | - Albert H. Olivencia-Yurvati
- 1Human Vascular Physiology Laboratory, Department of Physiology and Anatomy, University of North Texas Health Science Center, Fort Worth, Texas,2Department of Surgery, University of North Texas Health Science Center, Fort Worth, Texas
| | - Steven A. Romero
- 1Human Vascular Physiology Laboratory, Department of Physiology and Anatomy, University of North Texas Health Science Center, Fort Worth, Texas
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Adams JA, Uryash A, Lopez JR, Sackner MA. The Endothelium as a Therapeutic Target in Diabetes: A Narrative Review and Perspective. Front Physiol 2021; 12:638491. [PMID: 33708143 PMCID: PMC7940370 DOI: 10.3389/fphys.2021.638491] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2020] [Accepted: 01/29/2021] [Indexed: 12/18/2022] Open
Abstract
Diabetes has reached worldwide epidemic proportions, and threatens to be a significant economic burden to both patients and healthcare systems, and an important driver of cardiovascular mortality and morbidity. Improvement in lifestyle interventions (which includes increase in physical activity via exercise) can reduce diabetes and cardiovascular disease mortality and morbidity. Encouraging a population to increase physical activity and exercise is not a simple feat particularly in individuals with co-morbidities (obesity, heart disease, stroke, peripheral vascular disease, and those with cognitive and physical limitations). Translation of the physiological benefits of exercise within that vulnerable population would be an important step for improving physical activity goals and a stopgap measure to exercise. In large part many of the beneficial effects of exercise are due to the introduction of pulsatile shear stress (PSS) to the vascular endothelium. PSS is a well-known stimulus for endothelial homeostasis, and induction of a myriad of pathways which include vasoreactivity, paracrine/endocrine function, fibrinolysis, inflammation, barrier function, and vessel growth and formation. The endothelial cell mediates the balance between vasoconstriction and relaxation via the major vasodilator endothelial derived nitric oxide (eNO). eNO is critical for vasorelaxation, increasing blood flow, and an important signaling molecule that downregulates the inflammatory cascade. A salient feature of diabetes, is endothelial dysfunction which is characterized by a reduction of the bioavailability of vasodilators, particularly nitric oxide (NO). Cellular derangements in diabetes are also related to dysregulation in Ca2+ handling with increased intracellular Ca2+overload, and oxidative stress. PSS increases eNO bioavailability, reduces inflammatory phenotype, decreases intracellular Ca2+ overload, and increases antioxidant capacity. This narrative review and perspective will outline four methods to non-invasively increase PSS; Exercise (the prototype for increasing PSS), Enhanced External Counterpulsation (EECP), Whole Body Vibration (WBV), Passive Simulated Jogging and its predicate device Whole Body Periodic Acceleration, and will discuss current knowledge on their use in diabetes.
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Affiliation(s)
- Jose A Adams
- Division of Neonatology, Mount Sinai Medical Center, Miami Beach, FL, United States
| | - Arkady Uryash
- Division of Neonatology, Mount Sinai Medical Center, Miami Beach, FL, United States
| | - Jose R Lopez
- Department of Research, Mount Sinai Medical Center, Miami Beach, FL, United States
| | - Marvin A Sackner
- Department of Medicine, Mount Sinai Medical Center, Miami Beach, FL, United States
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Sano H, Watanabe M, Yamashita T, Tanishita K, Sudo R. Control of vessel diameters mediated by flow-induced outward vascular remodeling in vitro. Biofabrication 2020; 12:045008. [DOI: 10.1088/1758-5090/ab9316] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
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Calverley TA, Ogoh S, Marley CJ, Steggall M, Marchi N, Brassard P, Lucas SJE, Cotter JD, Roig M, Ainslie PN, Wisløff U, Bailey DM. HIITing the brain with exercise: mechanisms, consequences and practical recommendations. J Physiol 2020; 598:2513-2530. [PMID: 32347544 DOI: 10.1113/jp275021] [Citation(s) in RCA: 86] [Impact Index Per Article: 21.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2020] [Accepted: 04/15/2020] [Indexed: 01/30/2023] Open
Abstract
The increasing number of older adults has seen a corresponding growth in those affected by neurovascular diseases, including stroke and dementia. Since cures are currently unavailable, major efforts in improving brain health need to focus on prevention, with emphasis on modifiable risk factors such as promoting physical activity. Moderate-intensity continuous training (MICT) paradigms have been shown to confer vascular benefits translating into improved musculoskeletal, cardiopulmonary and cerebrovascular function. However, the time commitment associated with MICT is a potential barrier to participation, and high-intensity interval training (HIIT) has since emerged as a more time-efficient mode of exercise that can promote similar if not indeed superior improvements in cardiorespiratory fitness for a given training volume and further promote vascular adaptation. However, randomised controlled trials (RCTs) investigating the impact of HIIT on the brain are surprisingly limited. The present review outlines how the HIIT paradigm has evolved from a historical perspective and describes the established physiological changes including its mechanistic bases. Given the dearth of RCTs, the vascular benefits of MICT are discussed with a focus on the translational neuroprotective benefits including their mechanistic bases that could be further potentiated through HIIT. Safety implications are highlighted and components of an optimal HIIT intervention are discussed including practical recommendations. Finally, statistical effect sizes have been calculated to allow prospective research to be appropriately powered and optimise the potential for detecting treatment effects. Future RCTs that focus on the potential clinical benefits of HIIT are encouraged given the prevalence of cognitive decline in an ever-ageing population.
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Affiliation(s)
- Thomas A Calverley
- Neurovascular Research Laboratory, Faculty of Life Sciences and Education, University of South Wales, UK
| | - Shigehiko Ogoh
- Neurovascular Research Laboratory, Faculty of Life Sciences and Education, University of South Wales, UK.,Department of Biomedical Engineering, Faculty of Engineering, Toyo University, Saitama, Japan
| | - Christopher J Marley
- Neurovascular Research Laboratory, Faculty of Life Sciences and Education, University of South Wales, UK
| | - Martin Steggall
- Neurovascular Research Laboratory, Faculty of Life Sciences and Education, University of South Wales, UK
| | - Nicola Marchi
- Cerebrovascular and Glia Research Laboratory, Department of Neuroscience, Institute of Functional Genomics, Montpellier, France
| | - Patrice Brassard
- Department of Kinesiology, Faculty of Medicine, Université Laval, Québec, Canada
| | - Samuel J E Lucas
- School of Sport, Exercise and Rehabilitation Sciences, University of Birmingham, Birmingham, UK
| | - James D Cotter
- School of Physical Education, Sport and Exercise Sciences, University of Otago, Dunedin, New Zealand
| | - Marc Roig
- Faculty of Medicine, McGill University, Montreal, Canada
| | - Philip N Ainslie
- Neurovascular Research Laboratory, Faculty of Life Sciences and Education, University of South Wales, UK.,Centre for Heart, Lung and Vascular Health, School of Health and Exercise Sciences, University of British Columbia-Okanagan Campus, Kelowna, BC, Canada
| | - Ulrik Wisløff
- The Cardiac Exercise Research Group, Department of Circulation and Medical Imaging, Faculty of Medicine, Norwegian University of Science and Technology, Trondheim, Norway.,School of Human Movement and Nutrition Science, University of Queensland, Queensland, Australia
| | - Damian M Bailey
- Neurovascular Research Laboratory, Faculty of Life Sciences and Education, University of South Wales, UK
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Ma T, Bai YP. The hydromechanics in arteriogenesis. Aging Med (Milton) 2020; 3:169-177. [PMID: 33103037 PMCID: PMC7574636 DOI: 10.1002/agm2.12101] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2019] [Revised: 02/23/2020] [Accepted: 02/23/2020] [Indexed: 12/15/2022] Open
Abstract
Coronary heart diseases are tightly associated with aging. Although current revascularization therapies, such as percutaneous coronary interventions (PCI) and coronary artery bypass graft (CABG), improve the clinical outcomes of patients with coronary diseases, their application and therapeutic effects are limited in elderly patients. Thus, developing novel therapeutic strategies, like prompting collateral development or the process of arteriogenesis, is necessary for the treatment of the elderly with coronary diseases. Arteriogenesis (ie, the vascular remodeling from pre‐existent arterioles to collateral conductance networks) functions as an essential compensation for tissue hypoperfusion caused by artery occlusion or stenosis, and its mechanisms remain to be elucidated. In this review, we will summarize the roles of the major hydromechanical components in laminar conditions in arteriogenesis, and discuss the potential effects of disturbed flow components in non‐laminar conditions.
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Affiliation(s)
- Tianqi Ma
- Department of Geriatric Medicine Xiangya Hospital Central South University Changsha China
| | - Yong-Ping Bai
- Department of Geriatric Medicine Xiangya Hospital Central South University Changsha China
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11
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Mohammed M, Thurgood P, Gilliam C, Nguyen N, Pirogova E, Peter K, Khoshmanesh K, Baratchi S. Studying the Response of Aortic Endothelial Cells under Pulsatile Flow Using a Compact Microfluidic System. Anal Chem 2019; 91:12077-12084. [DOI: 10.1021/acs.analchem.9b03247] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
- Mokhaled Mohammed
- School of Engineering, RMIT University, Melbourne, VIC 3001, Australia
| | - Peter Thurgood
- School of Engineering, RMIT University, Melbourne, VIC 3001, Australia
| | | | - Ngan Nguyen
- School of Engineering, RMIT University, Melbourne, VIC 3001, Australia
| | - Elena Pirogova
- School of Engineering, RMIT University, Melbourne, VIC 3001, Australia
| | - Karlheinz Peter
- Baker Heart and Diabetes Institute, Melbourne, VIC 3004, Australia
| | | | - Sara Baratchi
- School of Health and Biomedical Sciences, RMIT University, Bundoora, VIC 3083, Australia
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12
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Is there a role for autophagy in ascending aortopathy associated with tricuspid or bicuspid aortic valve? Clin Sci (Lond) 2019; 133:805-819. [PMID: 30991346 DOI: 10.1042/cs20181092] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2018] [Revised: 02/27/2019] [Accepted: 03/18/2019] [Indexed: 01/04/2023]
Abstract
Autophagy is a conserved process by which cytoplasmatic elements are sequestered in vesicles and degraded after their fusion with lysosomes, thus recycling the precursor molecules. The autophagy-mediated removal of redundant/harmful/damaged organelles and biomolecules plays not only a replenishing function, but protects against stressful conditions through an adaptive mechanism. Autophagy, known to play a role in several pathological conditions, is now gaining increasing attention also in the perspective of the identification of the pathogenetic mechanisms at the basis of ascending thoracic aortic aneurysm (TAA), a localized or diffused dilatation of the aorta with an abnormal widening greater than 50 percent of the vessel's normal diameter. TAA is less frequent than abdominal aortic aneurysm (AAA), but is encountered with a higher percentage in patients with congenital heart disease or known genetic syndromes. Several biological aspects of TAA pathophysiology remain to be elucitated and therapeutic needs are still widely unmet. One of the most controversial and epidemiologically important forms of TAA is that associated with the congenital bicuspid malformation of the aortic valve (BAV). Dysregulated autophagy in response, for example, to wall shear stress alterations, has been demonstrated to affect the phenotype of vascular cells relevant to aortopathy, with potential consequences on signaling, remodeling, and angiogenesis. The most recent findings and hypotheses concerning the multiple aspects of autophagy and of its dysregulation are summarized, both in general and in the context of the different vascular cell types and of TAA progression, with particular reference to BAV-related aortopathy.
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Triantafillu UL, Park S, Kim Y. Fluid Shear Stress Induces Drug Resistance to Doxorubicin and Paclitaxel in the Breast Cancer Cell Line MCF7. ADVANCED THERAPEUTICS 2018. [DOI: 10.1002/adtp.201800112] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Affiliation(s)
- Ursula Lea Triantafillu
- Department of Chemical and Biological Engineering The University of Alabama Box 870203, Tuscaloosa AL 35487‐0203 USA
| | - Seungjo Park
- Department of Chemical and Biological Engineering The University of Alabama Box 870203, Tuscaloosa AL 35487‐0203 USA
| | - Yonghyun Kim
- Department of Chemical and Biological Engineering The University of Alabama Box 870203, Tuscaloosa AL 35487‐0203 USA
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Wang YX, Liu HB, Li PS, Yuan WX, Liu B, Liu ST, Qin KR. ROS and NO Dynamics in Endothelial Cells Exposed to Exercise-Induced Wall Shear Stress. Cell Mol Bioeng 2018; 12:107-120. [PMID: 31719902 DOI: 10.1007/s12195-018-00557-w] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2018] [Accepted: 09/29/2018] [Indexed: 02/06/2023] Open
Abstract
Introduction Intracellular reactive oxygen species (ROS) and nitric oxide (NO) levels are associated with vascular homeostasis and diseases. Exercise can modulate ROS and NO production through increasing frequency and magnitude of wall shear stress (WSS). However, the details of ROS and NO production in endothelial cells and their interplay under WSS induced by exercise at different intensities remain unclear. Methods In this study, we developed an in vitro multicomponent nonrectangular flow chamber system to simulate pulsatile WSS waveforms induced by moderate and high intensity exercise. Furthermore, the dynamic responses of ROS and NO in endothelial cells and the relationship between ROS and NO were investigated under the WSS induced by different intensity exercise. Results After exposing to WSS induced by moderate intensity exercise, endothelial cells produced more NO than those under high intensity exercise-induced WSS. In this process, ROS was found to play a dual role in the generation of intracellular NO. Under WSS induced by moderate intensity exercise, modest elevated ROS promoted NO production, whereas excessive ROS in endothelial cells exposed to WSS induced by high intensity exercise attenuated NO bioavailability. Interestingly, antioxidant N-acetylcysteine (NAC) could increase NO production under WSS induced by high intensity exercise. Conclusions Our results provide some cues for selecting appropriate exercise intensities and elevating benefits of exercise on endothelial function. Additionally, owing to the consistency of our results and some in vivo phenomena, this flow chamber system may serve as an in vitro exercise model of arterial vessel for future studies.
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Affiliation(s)
- Yan-Xia Wang
- Department of Engineering Mechanics, State Key Laboratory of Structural Analysis for Industrial Equipment, Dalian University of Technology, Dalian, 116024 China
| | - Hai-Bin Liu
- Department of Physical Education, Dalian University of Technology, Dalian, 116024 China
- School of Biomedical Engineering, Dalian University of Technology, Dalian, 116024 China
| | - Peng-Song Li
- Department of Physical Education, Dalian University of Technology, Dalian, 116024 China
| | - Wen-Xue Yuan
- Department of Physical Education, Dalian University of Technology, Dalian, 116024 China
| | - Bo Liu
- School of Biomedical Engineering, Dalian University of Technology, Dalian, 116024 China
| | - Shu-Tian Liu
- Department of Engineering Mechanics, State Key Laboratory of Structural Analysis for Industrial Equipment, Dalian University of Technology, Dalian, 116024 China
| | - Kai-Rong Qin
- School of Optoelectronic Engineering and Instrumentation Science, Dalian University of Technology, Dalian, 116024 China
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Park YG, Choi J, Jung HK, Song IK, Shin Y, Park SY, Seol JW. Fluid shear stress regulates vascular remodeling via VEGFR-3 activation, although independently of its ligand, VEGF-C, in the uterus during pregnancy. Int J Mol Med 2017; 40:1210-1216. [PMID: 28849193 PMCID: PMC5593466 DOI: 10.3892/ijmm.2017.3108] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2016] [Accepted: 08/22/2017] [Indexed: 11/06/2022] Open
Abstract
Early pregnancy is characterized by an increase in the blood volume of the uterus for embryonic development, thereby exerting fluid shear stress (FSS) on the vascular walls. The uterus experiences vascular remodeling to accommodate the increased blood flow. The blood flow-induced FSS elevates the expression of vascular endothelial growth factors (VEGFs) and their receptors, and regulates vascular remodeling through the activation of VEGF receptor-3 (VEGFR-3). However, the mechanisms responsible for FSS-induced VEGFR-3 expression in the uterus during pregnancy are unclear. In this study, we demonstrate that vascular remodeling in the uterus during pregnancy is regulated by FSS-induced VEGFR-3 expression. We examined the association between VEGFR-3 and FSS through in vivo and in vitro experiments. In vivo experiments revealed VEGFR-3 expression in the CD31-positive region of the uterus of pregnant mice; VEGF-C (ligand for VEGFR-3) was undetected in the uterus. These results confirmed that VEGFR-3 expression in the endometrium is independent of its ligand. In vitro studies experiments revealed that FSS induced morphological changes and increased VEGFR-3 expression in human uterine microvascular endothelial cells. Thus, VEGFR-3 activation by FSS is associated with vascular remodeling to allow increased blood flow in the uterus during pregnancy.
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Affiliation(s)
- Yang-Gyu Park
- Biosafety Research Institute, College of Veterinary Medicine, Chonbuk National University, Iksan, Jwonbuk 54596, Republic of Korea
| | - Jawun Choi
- Biosafety Research Institute, College of Veterinary Medicine, Chonbuk National University, Iksan, Jwonbuk 54596, Republic of Korea
| | - Hye-Kang Jung
- Biosafety Research Institute, College of Veterinary Medicine, Chonbuk National University, Iksan, Jwonbuk 54596, Republic of Korea
| | - In Kyu Song
- Biosafety Research Institute, College of Veterinary Medicine, Chonbuk National University, Iksan, Jwonbuk 54596, Republic of Korea
| | - Yongwhan Shin
- Auckland International College, Auckland 0600, New Zealand
| | - Sang-Youel Park
- Biosafety Research Institute, College of Veterinary Medicine, Chonbuk National University, Iksan, Jwonbuk 54596, Republic of Korea
| | - Jae-Won Seol
- Biosafety Research Institute, College of Veterinary Medicine, Chonbuk National University, Iksan, Jwonbuk 54596, Republic of Korea
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Al Asoom LI. Coronary angiogenic effect of long-term administration of Nigella sativa. Altern Ther Health Med 2017; 17:308. [PMID: 28610577 PMCID: PMC5470270 DOI: 10.1186/s12906-017-1795-z] [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] [Subscribe] [Scholar Register] [Received: 01/10/2017] [Accepted: 05/15/2017] [Indexed: 12/13/2022]
Abstract
Background Coronary angiogenesis is one of the preferable adaptive responses of aerobic training. Previous studies found inotropic and hypertrophic cardiac effects for long-term administration of Nigella sativa (NS), but no studies have explored its coronary angiogenic effect. The present study compared the effect of long-term NS- administration and exercise training on the induction of coronary angiogenesis. Method Fifteen adult male Wistar rats were divided into three groups: control, NS-fed, and exercise-trained (Ex). The NS-fed rats were administered 800 mg/Kg NS orally for eight weeks. The (Ex) rats were trained on a five-lane treadmill at a speed of 18 m/min and a grade of 32° for two hour/day for eight weeks. After the experiment, the hearts were extracted and immunohistological slides were prepared using rat vascular endothelial growth factor (VEGF), platelet endothelial cell adhesion molecule-1 (PECAM-1), Von Willebrand factor (VWF) and nitric oxide synthase-2 (NOS-2) antibodies (Ab). Photomicrographs were analysed using ImageJ software, and the % of the immunostained-area of 10 fields per specimen was recorded. Result VEGF was significantly higher in the NS- (2.59±1.37%) and Ex rats (2.51±1.86%) compared to the control group (1.58±0.78%) with P<0.01. The VWF was significantly lower in the two experimental groups (1.57±0.83%, 1.07±0.72%) for NS and Ex groups respectively, compared to the controls (2.38±1.72) with p<0.01. Only Ex group had a higher PECAM-1 (1.79±0.78%) and lower NOS-2 (0.83±0.57%) than the control group (1.19±1.17%, 1.25±1.19%) for PECAM-1 and NOS-2 with P<0.01 and P<0.05 respectively. Conclusions The present study demonstrated an increase in VEGF and a decrease of the VWF in the hearts of Nigella-fed and exercise-trained rats. This might indicate the potentiality for induction of coronary angiogenesis via long-term administration of NS and exercise training. NS effect on coronary angiogenesis needs to be explored further as it might lead to a new promising preventive and therapeutic agent of the ischemic heart disease.
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Zhang Q, Gao B, Chang Y. The study on hemodynamic effect of series type LVAD on aortic blood flow pattern: a primary numerical study. Biomed Eng Online 2016; 15:163. [PMID: 28155672 PMCID: PMC5260100 DOI: 10.1186/s12938-016-0252-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
Background Left ventricular assist device (LVAD) has become an alternative treatment for end-stage heart failure patients. Series type of LVAD, as a novel LVAD, has attracted more and more attention. The hemodynamic effects of series type LVAD on aortic blood pattern are considered as its important characteristics; however, the precise mechanism of it is still unclear. Methods To clarify the hemodynamic effects of series type LVAD on aortic blood flow pattern, a comparative study on the aortic blood flow pattern and hemodynamic states were carried out numerically for two cases, including series type LVAD support and normal condition. The steady-state computational fluid dynamic (CFD) approach was employed. The blood flow streamline, blood velocity vector and distribution of wall shear stress (WSS) were calculated to evaluate the differences of hemodynamic effects between both conditions. Results The results demonstrated that the aortic flow pattern under series type LVAD showed significant different from that of normal condition. The strength of aortic swirling flow was significantly enhanced by the series type LVAD support. Meanwhile, the rotating direction of swirling flow under LVAD support was also dominated by the rotating direction of series type LVAD. Moreover, the blood velocity and WSS under LVAD support were also significantly enhanced, compared with that under normal condition. Conclusion The hemodynamic states, including the aortic swirling flow characteristic, was significantly dominated by LVAD support. Present investigation could provide not only a useful information on the vascular complications caused by LVAD support, but also provide a useful guide for optimal the structure of the series type LVAD.
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Affiliation(s)
- Qi Zhang
- School of Life Science and BioEngineering, Beijing University of Technology, Beijing, 100124, People's Republic of China
| | - Bin Gao
- School of Life Science and BioEngineering, Beijing University of Technology, Beijing, 100124, People's Republic of China
| | - Yu Chang
- School of Life Science and BioEngineering, Beijing University of Technology, Beijing, 100124, People's Republic of China.
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Wang YX, Xiang C, Liu B, Zhu Y, Luan Y, Liu ST, Qin KR. A multi-component parallel-plate flow chamber system for studying the effect of exercise-induced wall shear stress on endothelial cells. Biomed Eng Online 2016; 15:154. [PMID: 28155716 PMCID: PMC5259904 DOI: 10.1186/s12938-016-0273-z] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
BACKGROUND In vivo studies have demonstrated that reasonable exercise training can improve endothelial function. To confirm the key role of wall shear stress induced by exercise on endothelial cells, and to understand how wall shear stress affects the structure and the function of endothelial cells, it is crucial to design and fabricate an in vitro multi-component parallel-plate flow chamber system which can closely replicate exercise-induced wall shear stress waveforms in artery. METHODS The in vivo wall shear stress waveforms from the common carotid artery of a healthy volunteer in resting and immediately after 30 min acute aerobic cycling exercise were first calculated by measuring the inner diameter and the center-line blood flow velocity with a color Doppler ultrasound. According to the above in vivo wall shear stress waveforms, we designed and fabricated a parallel-plate flow chamber system with appropriate components based on a lumped parameter hemodynamics model. To validate the feasibility of this system, human umbilical vein endothelial cells (HUVECs) line were cultured within the parallel-plate flow chamber under abovementioned two types of wall shear stress waveforms and the intracellular actin microfilaments and nitric oxide (NO) production level were evaluated using fluorescence microscope. RESULTS Our results show that the trends of resting and exercise-induced wall shear stress waveforms, especially the maximal, minimal and mean wall shear stress as well as oscillatory shear index, generated by the parallel-plate flow chamber system are similar to those acquired from the common carotid artery. In addition, the cellular experiments demonstrate that the actin microfilaments and the production of NO within cells exposed to the two different wall shear stress waveforms exhibit different dynamic behaviors; there are larger numbers of actin microfilaments and higher level NO in cells exposed in exercise-induced wall shear stress condition than resting wall shear stress condition. CONCLUSION The parallel-plate flow chamber system can well reproduce wall shear stress waveforms acquired from the common carotid artery in resting and immediately after exercise states. Furthermore, it can be used for studying the endothelial cells responses under resting and exercise-induced wall shear stress environments in vitro.
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Affiliation(s)
- Yan-Xia Wang
- State Key Laboratory of Structural Analysis for Industrial Equipment, Department of Engineering Mechanics, Dalian University of Technology, Dalian, China
| | - Cheng Xiang
- Department of Electrical and Computer Engineering, National University of Singapore, Singapore, Singapore
| | - Bo Liu
- Department of Biomedical Engineering, Dalian University of Technology, Dalian, China
| | - Yong Zhu
- Department of Biomedical Engineering, Dalian University of Technology, Dalian, China
| | - Yong Luan
- Department of Anesthesiology, The First Affiliated Hospital of Dalian Medical University, Dalian, China
| | - Shu-Tian Liu
- State Key Laboratory of Structural Analysis for Industrial Equipment, Department of Engineering Mechanics, Dalian University of Technology, Dalian, China
| | - Kai-Rong Qin
- Department of Biomedical Engineering, Dalian University of Technology, Dalian, China.
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Shear stress modulates endothelial KLF2 through activation of P2X4. Purinergic Signal 2015; 11:139-53. [PMID: 25563726 DOI: 10.1007/s11302-014-9442-3] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2014] [Accepted: 12/16/2014] [Indexed: 12/11/2022] Open
Abstract
Vascular endothelial cells that are in direct contact with blood flow are exposed to fluid shear stress and regulate vascular homeostasis. Studies report endothelial cells to release ATP in response to shear stress that in turn modulates cellular functions via P2 receptors with P2X4 mediating shear stress-induced calcium signaling and vasodilation. A recent study shows that a loss-of-function polymorphism in the human P2X4 resulting in a Tyr315>Cys variant is associated with increased pulse pressure and impaired endothelial vasodilation. Although the importance of shear stress-induced Krüppel-like factor 2 (KLF2) expression in atheroprotection is well studied, whether ATP regulates KLF2 remains unanswered and is the objective of this study. Using an in vitro model, we show that in human umbilical vein endothelial cells (HUVECs), apyrase decreased shear stress-induced KLF2, KLF4, and NOS3 expression but not that of NFE2L2. Exposure of HUVECs either to shear stress or ATPγS under static conditions increased KLF2 in a P2X4-dependent manner as was evident with both the receptor antagonist and siRNA knockdown. Furthermore, transient transfection of static cultures of human endothelial cells with the Tyr315>Cys mutant P2X4 construct blocked ATP-induced KLF2 expression. Also, P2X4 mediated the shear stress-induced phosphorylation of extracellular regulated kinase-5, a known regulator of KLF2. This study demonstrates a major physiological finding that the shear-induced effects on endothelial KLF2 axis are in part dependent on ATP release and P2X4, a previously unidentified mechanism.
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Villela NR, dos Santos AOMT, de Miranda ML, Bouskela E. Fluid resuscitation therapy in endotoxemic hamsters improves survival and attenuates capillary perfusion deficits and inflammatory responses by a mechanism related to nitric oxide. J Transl Med 2014; 12:232. [PMID: 25151363 PMCID: PMC4158098 DOI: 10.1186/s12967-014-0232-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2014] [Accepted: 08/15/2014] [Indexed: 12/21/2022] Open
Abstract
Background Relative hypovolemia is frequently found in early stages of severe sepsis and septic shock and prompt and aggressive fluid therapy has become standard of care improving tissue perfusion and patient outcome. This paper investigates the role of the nitric oxide pathway on beneficial microcirculatory effects of fluid resuscitation. Methods After skinfold chamber implantation procedures and endotoxemia induction by intravenous Escherichia coli lipopolysaccharide administration (2 mg.kg−1), male golden Syrian hamsters were fluid resuscitated and then sequentially treated with L-Nω-Nitroarginine and L-Arginine hydrochloride (LPS/FR/LNNA group). Intravital microscopy of skinfold chamber preparations allowed quantitative analysis of microvascular variables including venular leukocyte rolling and adhesion. Macro-hemodynamic, biochemical and hematological parameters as well as survival rate were also evaluated. Endotoxemic hamsters treated with fluid therapy alone (LPS/FR group) and non-treated animals (LPS group) served as controls. Results Fluid resuscitation was effective in reducing lipopolysaccharide-induced microcirculatory changes. After 3 hours of lipopolysaccharide administration, non-fluid resuscitated animals (LPS group) had the lowest functional capillary density (1% from baseline for LPS group vs. 19% for LPS/FR one; p <0.05). At the same time point, arteriolar mean internal diameter was significantly wider in LPS/FR group than in LPS one (100% vs. 50% from baseline). Fluid resuscitation also reduced leukocyte-endothelium interactions and sequestration (p <0.05 for LPS vs. LPS/FR group) and increased survival (median survival time: 2 and 5.5 days for LPS and LPS/FR groups, respectively; p <0.05). Nitric oxide synthase inhibition prevented these protective effects, while L-Arginine administration markedly restored many of them. Conclusion Our results suggest that the underlying mechanism of fluid therapy is the restoration of nitric oxide bioavailability, because inhibition of NOS prevented many of its beneficial effects. Nevertheless, further investigations are required in experimental models closer to conditions of human sepsis to confirm these results.
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Affiliation(s)
- Nivaldo Ribeiro Villela
- Department of Surgery, Division of Anesthesiology, Faculty of Medical Sciences, Rio de Janeiro State University, Boulevard 28 de Setembro, Rio de Janeiro, 77 - Vila Isabel, 20,551-030, RJ, Brazil.
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Bharath LP, Mueller R, Li Y, Ruan T, Kunz D, Goodrich R, Mills T, Deeter L, Sargsyan A, Anandh Babu PV, Graham TE, Symons JD. Impairment of autophagy in endothelial cells prevents shear-stress-induced increases in nitric oxide bioavailability. Can J Physiol Pharmacol 2014; 92:605-12. [PMID: 24941409 DOI: 10.1139/cjpp-2014-0017] [Citation(s) in RCA: 94] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Autophagy is a lysosomal catabolic process by which cells degrade or recycle their contents to maintain cellular homeostasis, adapt to stress, and respond to disease. Impairment of autophagy in endothelial cells studied under static conditions results in oxidant stress and impaired nitric oxide (NO) bioavailability. We tested the hypothesis that vascular autophagy is also important for induction of NO production caused by exposure of endothelial cells to shear stress (i.e., 3 h × ≈20 dyn/cm(2)). Atg3 is a requisite autophagy pathway mediator. Control cells treated with non-targeting control siRNA showed increased autophagy, reactive oxygen species (ROS) production, endothelial NO synthase (eNOS) phosphorylation, and NO production upon exposure to shear stress (p < 0.05 for all). In contrast, cells with >85% knockdown of Atg3 protein expression (via Atg3 siRNA) exhibited a profound impairment of eNOS phosphorylation, and were incapable of increasing NO in response to shear stress. Moreover, ROS accumulation and inflammatory cytokine production (MCP-1 and IL-8) were exaggerated (all p < 0.05) in response to shear stress. These findings reveal that autophagy not only plays a critical role in maintaining NO bioavailability, but may also be a key regulator of oxidant-antioxidant balance and inflammatory-anti-inflammatory balance that ultimately regulate endothelial cell responses to shear stress.
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Affiliation(s)
- Leena P Bharath
- a College of Health, University of Utah, Salt Lake City, UT 84112, USA
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