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Abstract
Atherosclerosis remains a major cause of morbidity and mortality worldwide, and a thorough understanding of the underlying pathophysiological mechanisms is crucial for the development of new therapeutic strategies. Although atherosclerosis is a systemic inflammatory disease, coronary atherosclerotic plaques are not uniformly distributed in the vascular tree. Experimental and clinical data highlight that biomechanical forces, including wall shear stress (WSS) and plaque structural stress (PSS), have an important role in the natural history of coronary atherosclerosis. Endothelial cell function is heavily influenced by changes in WSS, and longitudinal animal and human studies have shown that coronary regions with low WSS undergo increased plaque growth compared with high WSS regions. Local alterations in WSS might also promote transformation of stable to unstable plaque subtypes. Plaque rupture is determined by the balance between PSS and material strength, with plaque composition having a profound effect on PSS. Prospective clinical studies are required to ascertain whether integrating mechanical parameters with medical imaging can improve our ability to identify patients at highest risk of rapid disease progression or sudden cardiac events.
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102
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Endothelial Plasticity: Shifting Phenotypes through Force Feedback. Stem Cells Int 2016; 2016:9762959. [PMID: 26904133 PMCID: PMC4745942 DOI: 10.1155/2016/9762959] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2015] [Accepted: 12/31/2015] [Indexed: 12/28/2022] Open
Abstract
The endothelial lining of the vasculature is exposed to a large variety of biochemical and hemodynamic stimuli with different gradients throughout the vascular network. Adequate adaptation requires endothelial cells to be highly plastic, which is reflected by the remarkable heterogeneity of endothelial cells in tissues and organs. Hemodynamic forces such as fluid shear stress and cyclic strain are strong modulators of the endothelial phenotype and function. Although endothelial plasticity is essential during development and adult physiology, proatherogenic stimuli can induce adverse plasticity which contributes to disease. Endothelial-to-mesenchymal transition (EndMT), the hallmark of endothelial plasticity, was long thought to be restricted to embryonic development but has emerged as a pathologic process in a plethora of diseases. In this perspective we argue how shear stress and cyclic strain can modulate EndMT and discuss how this is reflected in atherosclerosis and pulmonary arterial hypertension.
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103
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Park WC, Seo I, Kim SH, Lee YJ, Ahn SV. Association between Resting Heart Rate and Inflammatory Markers (White Blood Cell Count and High-Sensitivity C-Reactive Protein) in Healthy Korean People. Korean J Fam Med 2016; 38:8-13. [PMID: 28197327 PMCID: PMC5305667 DOI: 10.4082/kjfm.2017.38.1.8] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2016] [Revised: 05/02/2016] [Accepted: 05/19/2016] [Indexed: 01/30/2023] Open
Abstract
Background Inflammation is an important underlying mechanism in the pathogenesis of atherosclerosis, and an elevated resting heart rate underlies the process of atherosclerotic plaque formation. We hypothesized an association between resting heart rate and subclinical inflammation. Methods Resting heart rate was recorded at baseline in the KoGES-ARIRANG (Korean Genome and Epidemiology Study on Atherosclerosis Risk of Rural Areas in the Korean General Population) cohort study, and was then divided into quartiles. Subclinical inflammation was measured by white blood cell count and high-sensitivity C-reactive protein. We used progressively adjusted regression models with terms for muscle mass, body fat proportion, and adiponectin in the fully adjusted models. We examined inflammatory markers as both continuous and categorical variables, using the clinical cut point of the highest quartile of white blood cell count (≥7,900/mm3) and ≥3 mg/dL for high-sensitivity C-reactive protein. Results Participants had a mean age of 56.3±8.1 years and a mean resting heart rate of 71.4±10.7 beats/min; 39.1% were men. In a fully adjusted model, an increased resting heart rate was significantly associated with a higher white blood cell count and higher levels of high-sensitivity C-reactive protein in both continuous (P for trend <0.001) and categorical (P for trend <0.001) models. Conclusion An increased resting heart rate is associated with a higher level of subclinical inflammation among healthy Korean people.
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Affiliation(s)
- Woo-Chul Park
- Department of Family Medicine, Yonsei University College of Medicine, Seoul, Korea
| | - Inho Seo
- Department of Family Medicine, Yonsei University College of Medicine, Seoul, Korea
| | - Shin-Hye Kim
- Department of Family Medicine, Yonsei University College of Medicine, Seoul, Korea
| | - Yong-Jae Lee
- Department of Family Medicine, Yonsei University College of Medicine, Seoul, Korea
| | - Song Vogue Ahn
- Department of Preventive Medicine, Institute of Genomic Cohort, Yonsei University Wonju College of Medicine, Wonju, Korea
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104
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Kilic ID, Findikoglu G, Alihanoglu YI, Yildiz BS, Uslu S, Rota S, Evrengul H. Circulating adhesion molecules and arterial stiffness. Cardiovasc J Afr 2015; 26:21-4. [PMID: 25784313 PMCID: PMC4392209 DOI: 10.5830/cvja-2014-060] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2014] [Accepted: 09/18/2014] [Indexed: 12/21/2022] Open
Abstract
Aim VCAM-1 and ICAM-1 are two important members of the immunoglobulin gene superfamily of adhesion molecules, and their potential role as biomarkers of diagnosis, severity and prognosis of cardiovascular disease has been investigated in a number of clinical studies. The aim of the present study was to determine the relationship between circulating ICAM-1 and VCAM-1 levels and aortic stiffness in patients referred for echocardiographic examination. Methods Aortic distensibility was determined by echocardiography using systolic and diastolic aortic diameters in 63 consecutive patients referred for echocardiography. Venous samples were collected in the morning after a 12-hour overnight fast, and serum concentrations of ICAM-1 and VCAM-1 were measured using commercial enzyme immunoassay kits. Results Data of a total of 63 participants (mean age 55.6 ± 10.5 years, 31 male) were included in the study. Circulating levels of adhesion molecules were VCAM-1: 12.604 ± 3.904 ng/ml and ICAM-1: 45.417 ± 31.429 ng/ml. We were unable to demonstrate any correlation between indices of aortic stiffness and VCAM-1 and ICAM-1 levels. Conclusion The role of soluble adhesion molecules in cardiovascular disease has not been fully established and clinical studies show inconsistent results. Our results indicate that levels of circulating adhesion molecules cannot be used as markers of aortic stiffness in patients.
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Affiliation(s)
- I D Kilic
- Department of Cardiology, Medical Faculty, Pamukkale University, Denizli, Turkey.
| | - G Findikoglu
- Department of Physical Medicine and Rehabilitation, Cardiopulmonary Unit, Medical Faculty, Pamukkale University, Denizli, Turkey
| | - Y I Alihanoglu
- Department of Cardiology, Medical Faculty, Pamukkale University, Denizli, Turkey
| | - B S Yildiz
- Department of Cardiology, Medical Faculty, Pamukkale University, Denizli, Turkey
| | - S Uslu
- Finike State Hospital, Antalya, Turkey
| | - S Rota
- Department of Biochemisty, Medical Faculty, Pamukkale University, Denizli, Turkey
| | - H Evrengul
- Department of Cardiology, Medical Faculty, Pamukkale University, Denizli, Turkey
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105
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The role of endothelial mechanosensitive genes in atherosclerosis and omics approaches. Arch Biochem Biophys 2015; 591:111-31. [PMID: 26686737 DOI: 10.1016/j.abb.2015.11.005] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2015] [Revised: 10/29/2015] [Accepted: 11/04/2015] [Indexed: 12/24/2022]
Abstract
Atherosclerosis is the leading cause of morbidity and mortality in the U.S., and is a multifactorial disease that preferentially occurs in regions of the arterial tree exposed to disturbed blood flow. The detailed mechanisms by which d-flow induces atherosclerosis involve changes in the expression of genes, epigenetic patterns, and metabolites of multiple vascular cells, especially endothelial cells. This review presents an overview of endothelial mechanobiology and its relation to the pathogenesis of atherosclerosis with special reference to the anatomy of the artery and the underlying fluid mechanics, followed by a discussion of a variety of experimental models to study the role of fluid mechanics and atherosclerosis. Various in vitro and in vivo models to study the role of flow in endothelial biology and pathobiology are discussed in this review. Furthermore, strategies used for the global profiling of the genome, transcriptome, miR-nome, DNA methylome, and metabolome, as they are important to define the biological and pathophysiological mechanisms of atherosclerosis. These "omics" approaches, especially those which derive data based on a single animal model, provide unprecedented opportunities to not only better understand the pathophysiology of atherosclerosis development in a holistic and integrative manner, but also to identify novel molecular and diagnostic targets.
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106
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Atkinson CL, Lewis NCS, Carter HH, Thijssen DHJ, Ainslie PN, Green DJ. Impact of sympathetic nervous system activity on post-exercise flow-mediated dilatation in humans. J Physiol 2015; 593:5145-56. [PMID: 26437709 PMCID: PMC4666994 DOI: 10.1113/jp270946] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2015] [Accepted: 09/21/2015] [Indexed: 02/06/2023] Open
Abstract
Transient reduction in vascular function following systemic large muscle group exercise has previously been reported in humans. The mechanisms responsible are currently unknown. We hypothesised that sympathetic nervous system activation, induced by cycle ergometer exercise, would contribute to post-exercise reductions in flow-mediated dilatation (FMD). Ten healthy male subjects (28 ± 5 years) undertook two 30 min sessions of cycle exercise at 75% HR(max). Prior to exercise, individuals ingested either a placebo or an α1-adrenoreceptor blocker (prazosin; 0.05 mg kg(-1)). Central haemodynamics, brachial artery shear rate (SR) and blood flow profiles were assessed throughout each exercise bout and in response to brachial artery FMD, measured prior to, immediately after and 60 min after exercise. Cycle exercise increased both mean and antegrade SR (P < 0.001) with retrograde SR also elevated under both conditions (P < 0.001). Pre-exercise FMD was similar on both occasions, and was significantly reduced (27%) immediately following exercise in the placebo condition (t-test, P = 0.03). In contrast, FMD increased (37%) immediately following exercise in the prazosin condition (t-test, P = 0.004, interaction effect P = 0.01). Post-exercise FMD remained different between conditions after correction for baseline diameters preceding cuff deflation and also post-deflation SR. No differences in FMD or other variables were evident 60 min following recovery. Our results indicate that sympathetic vasoconstriction competes with endothelium-dependent dilator activity to determine post-exercise arterial function. These findings have implications for understanding the chronic impacts of interventions, such as exercise training, which affect both sympathetic activity and arterial shear stress.
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Affiliation(s)
- Ceri L Atkinson
- School of Sports Science, Exercise and Health, The University of Western Australia, Crawley, Western Australia
| | - Nia C S Lewis
- School of Health and Exercise Sciences, University of British Columbia Okanagan, Kelowna, British Columbia, Canada
| | - Howard H Carter
- School of Sports Science, Exercise and Health, The University of Western Australia, Crawley, Western Australia
| | - Dick H J Thijssen
- Research Institute for Sport and Exercise Science, Liverpool John Moores University, Liverpool, UK
- Radboud Institute for Health Sciences, Department of Physiology, Nijmegen, Netherlands
| | - Philip N Ainslie
- School of Health and Exercise Sciences, University of British Columbia Okanagan, Kelowna, British Columbia, Canada
| | - Daniel J Green
- School of Sports Science, Exercise and Health, The University of Western Australia, Crawley, Western Australia
- Research Institute for Sport and Exercise Science, Liverpool John Moores University, Liverpool, UK
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107
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Palombo C, Kozakova M. Arterial stiffness, atherosclerosis and cardiovascular risk: Pathophysiologic mechanisms and emerging clinical indications. Vascul Pharmacol 2015; 77:1-7. [PMID: 26643779 DOI: 10.1016/j.vph.2015.11.083] [Citation(s) in RCA: 293] [Impact Index Per Article: 32.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2015] [Revised: 08/25/2015] [Accepted: 11/26/2015] [Indexed: 12/14/2022]
Abstract
Arterial stiffness results from a degenerative process affecting mainly the extracellular matrix of elastic arteries under the effect of aging and risk factors. Changes in extracellular matrix proteins and in the mechanical properties of the vessel wall related to arterial stiffening may activate number of mechanisms involved also in the process of atherosclerosis. Several noninvasive methods are now available to estimate large artery stiffness in the clinical setting, including carotid-femoral pulse wave velocity, the reference for aortic stiffness estimate, and local distensibility measures of superficial arteries, namely carotid and femoral. An independent predictive value of arterial stiffness for cardiovascular events has been demonstrated in general as well as in selected populations, and reference values adjusted for age and blood pressure have been established. Thus, arterial stiffness is emerging as an interesting tissue biomarker for cardiovascular risk stratification and estimation of the individual "biological age". This paper overviews the mechanisms accounting for development and progression of arterial stiffness and for associations between arterial stiffness, atherosclerotic burden and incident cardiovascular events, summarizes the evidence and caveat for clinical use of stiffness as surrogate marker of cardiovascular risk, and briefly outlines some emerging methods for large artery stiffness characterization.
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Affiliation(s)
- Carlo Palombo
- Department of Surgical, Medical and Molecular Pathology and Critical Area Medicine, University of Pisa, Italy.
| | - Michaela Kozakova
- Department of Clinical and Experimental Medicine, University of Pisa, Italy
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108
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Allan PD, Faulkner J, O'Donnell T, Lanford J, Wong LK, Saleem S, Woolley B, Lambrick D, Stoner L, Tzeng YC. Hemodynamic variability and cerebrovascular control after transient cerebral ischemia. Physiol Rep 2015; 3:3/11/e12602. [PMID: 26537345 PMCID: PMC4673632 DOI: 10.14814/phy2.12602] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
We investigated if hemodynamic variability, cerebral blood flow (CBF) regulation, and their interrelationships differ between patients with transient ischemic attack (TIA) and controls. We recorded blood pressure (BP) and bilateral middle cerebral artery flow velocity (MCAv) in a cohort of TIA patients (n = 17), and age-matched controls (n = 15). Spontaneous fluctuations in BP and MCAv were characterized by spectral power analysis, and CBF regulation was assessed by wavelet phase synchronization analysis in the very low- (0.02–0.07 Hz), low- (0.07–0.20 Hz), and high-frequency (0.20–0.40 Hz) ranges. Furthermore, cerebrovascular CO2 reactivity was assessed as a second metric of CBF regulation by inducing hypercapnia with 8% CO2 inhalation followed by hyperventilation driven hypocapnia. We found that TIA was associated with higher BP power (group effect, P < 0.05), but not MCAv power (P = 0.11). CBF regulation (assessed by wavelet phase synchronization and CO2 reactivity) was intact in patients (all P ≥ 0.075) across both hemispheres (all P ≥ 0.51). Pooled data (controls and affected hemisphere of patients) showed that BP and MCAv power were positively correlated at all frequency ranges (R2 = 0.20–0.80, all P < 0.01). Furthermore, LF phase synchronization index was a significant determinant of MCAv power (P < 0.05), while VLF and HF phase synchronization index, and TIA were not (all P ≥ 0.50). These results indicate that CBF stability and control is maintained in TIA patients, but BPV is markedly elevated. BPV attenuation may be an important therapeutic strategy for enhancing secondary stroke prevention in patients who suffer a TIA.
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Affiliation(s)
- Philip D Allan
- Centre for Translational Physiology, University of Otago, Wellington, New Zealand Department of Surgery and Anaesthesia, University of Otago, Wellington, New Zealand
| | - James Faulkner
- Department of Sport and Exercise, University of Winchester, Winchester, UK
| | - Terrence O'Donnell
- Centre for Translational Physiology, University of Otago, Wellington, New Zealand Department of Surgery and Anaesthesia, University of Otago, Wellington, New Zealand
| | - Jeremy Lanford
- Department of Neurology, Wellington Hospital, Wellington, New Zealand
| | - Lai-Kin Wong
- Department of Neurology, Wellington Hospital, Wellington, New Zealand
| | - Saqib Saleem
- Centre for Translational Physiology, University of Otago, Wellington, New Zealand School of Engineering and Computer Science, Victoria University of Wellington, Wellington, New Zealand
| | - Brandon Woolley
- School of Sport and Exercise, Massey University, Wellington, New Zealand
| | - Danielle Lambrick
- Faculty of Health Science, University of Southampton, Southampton, UK
| | - Lee Stoner
- School of Sport and Exercise, Massey University, Wellington, New Zealand
| | - Yu-Chieh Tzeng
- Centre for Translational Physiology, University of Otago, Wellington, New Zealand Department of Surgery and Anaesthesia, University of Otago, Wellington, New Zealand
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Thijssen DHJ, Schreuder THA, Newcomer SW, Laughlin MH, Hopman MTE, Green DJ. Impact of 2-Weeks Continuous Increase in Retrograde Shear Stress on Brachial Artery Vasomotor Function in Young and Older Men. J Am Heart Assoc 2015; 4:e001968. [PMID: 26416875 PMCID: PMC4845130 DOI: 10.1161/jaha.115.001968] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/09/2015] [Accepted: 08/24/2015] [Indexed: 11/16/2022]
Abstract
BACKGROUND Although acute elevation in retrograde shear rate (SR) impairs endothelial function, no previous study has explored the effect of prolonged elevation of retrograde SR on conduit artery vascular function. We examined the effect of 2-weeks elevation of retrograde SR on brachial artery endothelial function in young and in older men. METHODS AND RESULTS Thirteen healthy young (23±2 years) and 13 older men (61±5 years) were instructed to continuously wear a compression sleeve around the right forearm to chronically (2 weeks) elevate brachial artery retrograde SR in 1 arm. We assessed SR, diameter, and flow-mediated dilation in both the sleeve and contralateral control arms at baseline and after 30 minutes and 2 weeks of continuous sleeve application. The sleeve intervention increased retrograde SR after 30 minutes and 2 weeks in both young and older men (P=0.03 and 0.001, respectively). In young men, brachial artery flow-mediated dilation % was lower after 30 minutes and 2 weeks (P=0.004), while resting artery diameter was reduced after 2 weeks (P=0.005). The contralateral arm showed no change in retrograde SR or flow-mediated dilation % (P=0.32 and 0.26, respectively), but a decrease in diameter (P=0.035). In older men, flow-mediated dilation % and diameter did not change in either arm (all P>0.05). CONCLUSIONS Thirty-minute elevation in retrograde SR in young men caused impaired endothelial function, while 2-week exposure to elevated levels of retrograde SR was associated with a comparable decrease in endothelial function. Interestingly, these vascular changes were not present in older men, suggesting age-related vascular changes to elevation in retrograde SR.
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Affiliation(s)
- Dick H. J. Thijssen
- Department of PhysiologyRadboud Institute for Health SciencesRadboud University Medical CenterNijmegenThe Netherlands
- Research Institute for Sport and Exercise ScienceLiverpool John Moores UniversityLiverpoolUnited Kingdom
| | - Tim H. A. Schreuder
- Department of PhysiologyRadboud Institute for Health SciencesRadboud University Medical CenterNijmegenThe Netherlands
| | | | | | - Maria T. E. Hopman
- Department of PhysiologyRadboud Institute for Health SciencesRadboud University Medical CenterNijmegenThe Netherlands
| | - Daniel J. Green
- Research Institute for Sport and Exercise ScienceLiverpool John Moores UniversityLiverpoolUnited Kingdom
- School of Sport Science, Exercise and HealthThe University of Western AustraliaCrawleyWestern AustraliaAustralia
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110
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Vandersmissen I, Craps S, Depypere M, Coppiello G, van Gastel N, Maes F, Carmeliet G, Schrooten J, Jones EAV, Umans L, Devlieger R, Koole M, Gheysens O, Zwijsen A, Aranguren XL, Luttun A. Endothelial Msx1 transduces hemodynamic changes into an arteriogenic remodeling response. J Cell Biol 2015; 210:1239-56. [PMID: 26391659 PMCID: PMC4586738 DOI: 10.1083/jcb.201502003] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2015] [Accepted: 08/18/2015] [Indexed: 12/25/2022] Open
Abstract
During peripheral arterial disease, MSX1 acts downstream of BMP–SMAD signaling to transduce the arterial shear stimulus into an arteriogenic remodeling response. MSX1 activates collateral endothelium into a proinflammatory state through ICAM1/VCAM1 up-regulation, resulting in increased leukocyte infiltration and collateral remodeling. Collateral remodeling is critical for blood flow restoration in peripheral arterial disease and is triggered by increasing fluid shear stress in preexisting collateral arteries. So far, no arterial-specific mediators of this mechanotransduction response have been identified. We show that muscle segment homeobox 1 (MSX1) acts exclusively in collateral arterial endothelium to transduce the extrinsic shear stimulus into an arteriogenic remodeling response. MSX1 was specifically up-regulated in remodeling collateral arteries. MSX1 induction in collateral endothelial cells (ECs) was shear stress driven and downstream of canonical bone morphogenetic protein–SMAD signaling. Flow recovery and collateral remodeling were significantly blunted in EC-specific Msx1/2 knockout mice. Mechanistically, MSX1 linked the arterial shear stimulus to arteriogenic remodeling by activating the endothelial but not medial layer to a proinflammatory state because EC but not smooth muscle cellMsx1/2 knockout mice had reduced leukocyte recruitment to remodeling collateral arteries. This reduced leukocyte infiltration in EC Msx1/2 knockout mice originated from decreased levels of intercellular adhesion molecule 1 (ICAM1)/vascular cell adhesion molecule 1 (VCAM1), whose expression was also in vitro driven by promoter binding of MSX1.
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Affiliation(s)
- Ine Vandersmissen
- Department of Cardiovascular Sciences, Center for Molecular and Vascular Biology, KU Leuven, 3000 Leuven, Belgium
| | - Sander Craps
- Department of Cardiovascular Sciences, Center for Molecular and Vascular Biology, KU Leuven, 3000 Leuven, Belgium
| | - Maarten Depypere
- Department of Electrical Engineering/Processing Speech and Images, Medical Image Computing, KU Leuven, 3000 Leuven, Belgium
| | - Giulia Coppiello
- Department of Cardiovascular Sciences, Center for Molecular and Vascular Biology, KU Leuven, 3000 Leuven, Belgium Hematology and Cell Therapy Area, Clínica Universidad de Navarra and Division of Oncology, Center for Applied Medical Research, University of Navarra, 31008 Pamplona, Spain
| | - Nick van Gastel
- Laboratory of Clinical and Experimental Endocrinology, Division of Skeletal Tissue Engineering, Department of Clinical and Experimental Medicine, KU Leuven, 3000 Leuven, Belgium Prometheus, Division of Skeletal Tissue Engineering, KU Leuven, 3000 Leuven, Belgium
| | - Frederik Maes
- Department of Electrical Engineering/Processing Speech and Images, Medical Image Computing, KU Leuven, 3000 Leuven, Belgium
| | - Geert Carmeliet
- Laboratory of Clinical and Experimental Endocrinology, Division of Skeletal Tissue Engineering, Department of Clinical and Experimental Medicine, KU Leuven, 3000 Leuven, Belgium Prometheus, Division of Skeletal Tissue Engineering, KU Leuven, 3000 Leuven, Belgium
| | - Jan Schrooten
- Prometheus, Division of Skeletal Tissue Engineering, KU Leuven, 3000 Leuven, Belgium Department of Materials Engineering, KU Leuven, 3000 Leuven, Belgium
| | - Elizabeth A V Jones
- Department of Cardiovascular Sciences, Center for Molecular and Vascular Biology, KU Leuven, 3000 Leuven, Belgium
| | - Lieve Umans
- Laboratory of Developmental Signaling, VIB Center for the Biology of Disease, KU Leuven, 3000 Leuven, Belgium Laboratory of Molecular Biology (Celgen), Department of Development and Regeneration, KU Leuven, 3000 Leuven, Belgium
| | - Roland Devlieger
- Department of Gynecology and Obstetrics, University Hospital Leuven, 3000 Leuven, Belgium Department of Development and Regeneration, KU Leuven, 3000 Leuven, Belgium
| | - Michel Koole
- Department of Imaging and Pathology, KU Leuven, 3000 Leuven, Belgium
| | - Olivier Gheysens
- Department of Nuclear Medicine University Hospital Leuven, 3000 Leuven, Belgium Department of Imaging and Pathology, KU Leuven, 3000 Leuven, Belgium
| | - An Zwijsen
- Laboratory of Developmental Signaling, VIB Center for the Biology of Disease, KU Leuven, 3000 Leuven, Belgium Department of Human Genetics, KU Leuven, 3000 Leuven, Belgium
| | - Xabier L Aranguren
- Department of Cardiovascular Sciences, Center for Molecular and Vascular Biology, KU Leuven, 3000 Leuven, Belgium Hematology and Cell Therapy Area, Clínica Universidad de Navarra and Division of Oncology, Center for Applied Medical Research, University of Navarra, 31008 Pamplona, Spain
| | - Aernout Luttun
- Department of Cardiovascular Sciences, Center for Molecular and Vascular Biology, KU Leuven, 3000 Leuven, Belgium
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Totosy de Zepetnek JO, Ditor DS, Au JS, MacDonald MJ. Impact of shear rate pattern on upper and lower limb conduit artery endothelial function in both spinal cord-injured and able-bodied men. Exp Physiol 2015. [DOI: 10.1113/ep085056] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
| | - D. S. Ditor
- Department of Kinesiology; Brock University; St Catharines Ontario Canada L2S 3A1
| | - J. S. Au
- Department of Kinesiology; McMaster University; Hamilton Ontario Canada L8S 4L8
| | - M. J. MacDonald
- Department of Kinesiology; McMaster University; Hamilton Ontario Canada L8S 4L8
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Large M, Hehlgans S, Reichert S, Gaipl US, Fournier C, Rödel C, Weiss C, Rödel F. Study of the anti-inflammatory effects of low-dose radiation: The contribution of biphasic regulation of the antioxidative system in endothelial cells. Strahlenther Onkol 2015; 191:742-9. [PMID: 26051282 DOI: 10.1007/s00066-015-0848-9] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2015] [Accepted: 04/22/2015] [Indexed: 12/14/2022]
Abstract
BACKGROUND We examined (a) the expression of the antioxidative factor glutathione peroxidase (GPx) and the transcription factor nuclear factor E2-related factor 2 (Nrf2) following low-dose X-irradiation in endothelial cells (ECs) and (b) the impact of reactive oxygen species (ROS) and Nrf2 on functional properties of ECs to gain further knowledge about the anti-inflammatory mode of action of low doses of ionizing radiation. MATERIAL AND METHODS EA.hy926 ECs and primary human dermal microvascular ECs (HMVEC) were stimulated by tumor necrosis factor-α (TNF-α, 20 ng/ml) 4 h before irradiation with single doses ranging from 0.3 to 3 Gy. The expression and activity of GPx and Nrf2 were analyzed by flow cytometry, colorimetric assays, and real-time PCR. The impact of ROS and Nrf2 on peripheral blood mononuclear cell (PBMC) adhesion was assayed in the presence of the ROS scavenger N-acetyl-L-cysteine (NAC) and Nrf2 activator AI-1. RESULTS Following a low-dose exposure, we observed in EA.hy926 EC and HMVECs a discontinuous expression and enzymatic activity of GPx concomitant with a lowered expression and DNA binding activity of Nrf2 that was most pronounced at a dose of 0.5 Gy. Scavenging of ROS by NAC and activation of Nrf2 by AI-1 significantly diminished a lowered adhesion of PBMC to EC at a dose of 0.5 Gy. CONCLUSION Low-dose irradiation resulted in a nonlinear expression and activity of major compounds of the antioxidative system that might contribute to anti-inflammatory effects in stimulated ECs.
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Affiliation(s)
- Martin Large
- Department of Radiotherapy and Oncology, Goethe University Frankfurt, Theodor-Stern-Kai 7, 60590, Frankfurt am Main, Germany,
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Kim JS, Kim B, Lee H, Thakkar S, Babbitt DM, Eguchi S, Brown MD, Park JY. Shear stress-induced mitochondrial biogenesis decreases the release of microparticles from endothelial cells. Am J Physiol Heart Circ Physiol 2015; 309:H425-33. [PMID: 26024684 DOI: 10.1152/ajpheart.00438.2014] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/23/2014] [Accepted: 05/26/2015] [Indexed: 01/21/2023]
Abstract
The concept of enhancing structural integrity of mitochondria has emerged as a novel therapeutic option for cardiovascular disease. Flow-induced increase in laminar shear stress is a potent physiological stimulant associated with exercise, which exerts atheroprotective effects in the vasculature. However, the effect of laminar shear stress on mitochondrial remodeling within the vascular endothelium and its related functional consequences remain largely unknown. Using in vitro and in vivo complementary studies, here, we report that aerobic exercise alleviates the release of endothelial microparticles in prehypertensive individuals and that these salutary effects are, in part, mediated by shear stress-induced mitochondrial biogenesis. Circulating levels of total (CD31(+)/CD42a(-)) and activated (CD62E(+)) microparticles released by endothelial cells were significantly decreased (∼40% for both) after a 6-mo supervised aerobic exercise training program in individuals with prehypertension. In cultured human endothelial cells, laminar shear stress reduced the release of endothelial microparticles, which was accompanied by an increase in mitochondrial biogenesis through a sirtuin 1 (SIRT1)-dependent mechanism. Resveratrol, a SIRT1 activator, treatment showed similar effects. SIRT1 knockdown using small-interfering RNA completely abolished the protective effect of shear stress. Disruption of mitochondrial integrity by either antimycin A or peroxisome proliferator-activated receptor-γ coactivator-1α small-interfering RNA significantly increased the number of total, and activated, released endothelial microparticles, and shear stress restored these back to basal levels. Collectively, these data demonstrate a critical role of endothelial mitochondrial integrity in preserving endothelial homeostasis. Moreover, prolonged laminar shear stress, which is systemically elevated during aerobic exercise in the vessel wall, mitigates endothelial dysfunction by promoting mitochondrial biogenesis.
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Affiliation(s)
- Ji-Seok Kim
- Department of Kinesiology, Temple University, Philadelphia, Pennsylvania
| | - Boa Kim
- Department of Kinesiology, Temple University, Philadelphia, Pennsylvania; Cardiovascular Research Center, Temple University School of Medicine, Philadelphia, Pennsylvania; and
| | - Hojun Lee
- Department of Kinesiology, Temple University, Philadelphia, Pennsylvania
| | - Sunny Thakkar
- Department of Kinesiology, Temple University, Philadelphia, Pennsylvania
| | - Dianne M Babbitt
- Department of Kinesiology, Temple University, Philadelphia, Pennsylvania
| | - Satoru Eguchi
- Cardiovascular Research Center, Temple University School of Medicine, Philadelphia, Pennsylvania; and
| | - Michael D Brown
- Department of Kinesiology and Nutrition and Integrative Physiology Laboratory, University of Illinois at Chicago, Chicago, Illinois
| | - Joon-Young Park
- Department of Kinesiology, Temple University, Philadelphia, Pennsylvania; Cardiovascular Research Center, Temple University School of Medicine, Philadelphia, Pennsylvania; and
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Dunn J, Simmons R, Thabet S, Jo H. The role of epigenetics in the endothelial cell shear stress response and atherosclerosis. Int J Biochem Cell Biol 2015; 67:167-76. [PMID: 25979369 DOI: 10.1016/j.biocel.2015.05.001] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2015] [Revised: 04/30/2015] [Accepted: 05/02/2015] [Indexed: 12/15/2022]
Abstract
Currently in the field of vascular biology, the role of epigenetics in endothelial cell biology and vascular disease has attracted more in-depth study. Using both in vitro and in vivo models of blood flow, investigators have recently begun to reveal the underlying epigenetic regulation of endothelial gene expression. Recently, our group, along with two other independent groups, have demonstrated that blood flow controls endothelial gene expression by DNA methyltransferases (DNMT1 and 3A). Disturbed flow (d-flow), characterized by low and oscillating shear stress (OS), is pro-atherogenic and induces expression of DNMT1 both in vivo and in vitro. D-flow regulates genome-wide DNA methylation patterns in a DNMT-dependent manner. The DNMT inhibitor 5-Aza-2'deoxycytidine (5Aza) or DNMT1 siRNA reduces OS-induced endothelial inflammation. Moreover, 5Aza inhibits the development of atherosclerosis in ApoE(-/-) mice. Through a systems biological analysis of genome-wide DNA methylation patterns and gene expression data, we found 11 mechanosensitive genes which were suppressed by d-flow in vivo, experienced hypermethylation in their promoter region in response to d-flow, and were rescued by 5Aza treatment. Interestingly, among these mechanosensitive genes, the two transcription factors HoxA5 and Klf3 contain cAMP-response-elements (CRE), which may indicate that methylation of CRE sites could serve as a mechanosensitive master switch in gene expression. These findings provide new insight into the mechanism by which flow controls epigenetic DNA methylation patterns, which in turn alters endothelial gene expression, regulates vascular biology, and induces atherosclerosis. These novel findings have broad implications for understanding the biochemical mechanisms of atherogenesis and provide a basis for identifying potential therapeutic targets for atherosclerosis. This article is part of a Directed Issue entitled: Epigenetics dynamics in development and disease.
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Affiliation(s)
- Jessilyn Dunn
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, USA
| | - Rachel Simmons
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, USA
| | - Salim Thabet
- Division of Cardiology, Georgia Institute of Technology and Emory University, USA
| | - Hanjoong Jo
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, USA; Division of Cardiology, Georgia Institute of Technology and Emory University, USA.
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Dunn J, Thabet S, Jo H. Flow-Dependent Epigenetic DNA Methylation in Endothelial Gene Expression and Atherosclerosis. Arterioscler Thromb Vasc Biol 2015; 35:1562-9. [PMID: 25953647 DOI: 10.1161/atvbaha.115.305042] [Citation(s) in RCA: 66] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2015] [Accepted: 04/27/2015] [Indexed: 12/31/2022]
Abstract
Epigenetic mechanisms that regulate endothelial cell gene expression are now emerging. DNA methylation is the most stable epigenetic mark that confers persisting changes in gene expression. Not only is DNA methylation important in rendering cell identity by regulating cell type-specific gene expression throughout differentiation, but it is becoming clear that DNA methylation also plays a key role in maintaining endothelial cell homeostasis and in vascular disease development. Disturbed blood flow causes atherosclerosis, whereas stable flow protects against it by differentially regulating gene expression in endothelial cells. Recently, we and others have shown that flow-dependent gene expression and atherosclerosis development are regulated by mechanisms dependent on DNA methyltransferases (1 and 3A). Disturbed blood flow upregulates DNA methyltransferase expression both in vitro and in vivo, which leads to genome-wide DNA methylation alterations and global gene expression changes in a DNA methyltransferase-dependent manner. These studies revealed several mechanosensitive genes, such as HoxA5, Klf3, and Klf4, whose promoters were hypermethylated by disturbed blood flow, but rescued by DNA methyltransferases inhibitors such as 5Aza-2-deoxycytidine. These findings provide new insight into the mechanism by which flow controls epigenomic DNA methylation patterns, which in turn alters endothelial gene expression, regulates vascular biology, and modulates atherosclerosis development.
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Affiliation(s)
- Jessilyn Dunn
- From the Wallace H. Coulter Department of Biomedical Engineering (J.D., S.T., H.J.) and Division of Cardiology, Georgia Institute of Technology and Emory University, Atlanta
| | - Salim Thabet
- From the Wallace H. Coulter Department of Biomedical Engineering (J.D., S.T., H.J.) and Division of Cardiology, Georgia Institute of Technology and Emory University, Atlanta
| | - Hanjoong Jo
- From the Wallace H. Coulter Department of Biomedical Engineering (J.D., S.T., H.J.) and Division of Cardiology, Georgia Institute of Technology and Emory University, Atlanta.
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Schreuder THA, Green DJ, Hopman MTE, Thijssen DHJ. Impact of retrograde shear rate on brachial and superficial femoral artery flow-mediated dilation in older subjects. Atherosclerosis 2015; 241:199-204. [PMID: 25917080 DOI: 10.1016/j.atherosclerosis.2015.04.017] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/31/2014] [Revised: 04/03/2015] [Accepted: 04/13/2015] [Indexed: 11/18/2022]
Abstract
UNLABELLED An inverse, dose-dependent relationship between retrograde shear rate and brachial artery endothelial function exists in young subjects. This relationship has not been investigated in older adults, who have been related to lower endothelial function, higher resting retrograde shear rate and higher risk of cardiovascular disease. AIM To investigate the impact of a step-wise increase in retrograde shear stress on flow-mediated dilation in older males in the upper and lower limbs. METHODS Fifteen older (68 ± 9 years) men reported to the laboratory 3 times. We examined brachial artery flow-mediated dilation before and after 30-min exposure to cuff inflation around the forearm at 0, 30 and 60 mmHg, to manipulate retrograde shear rate. Subsequently, the 30-min intervention was repeated in the superficial femoral artery. Order of testing (vessel and intervention) was randomised. RESULTS Increases in cuff pressure resulted in dose-dependent increases in retrograde shear in both the brachial and superficial femoral artery in older subjects. In both the brachial and the superficial femoral artery, no change in endothelial function in response to increased retrograde shear was observed in older males ('time' P = 0.274, 'cuff*time P = 0.791', 'cuff*artery*time P = 0.774'). CONCLUSION In contrast with young subjects, we found that acute elevation in retrograde shear rate does not impair endothelial function in older humans. This may suggest that subjects with a priori endothelial dysfunction are less responsive or requires a larger shear rate stimulus to alter endothelial function.
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Affiliation(s)
- Tim H A Schreuder
- Radboud Institute for Health Sciences, Radboud University Medical Center, The Netherlands
| | - Daniel J Green
- Research Institute for Sport and Exercise Sciences, Liverpool John Moores University, Liverpool, United Kingdom; School of Sport Science, Exercise and Health, The University of Western Australia, Crawley, Western Australia, Australia
| | - Maria T E Hopman
- Radboud Institute for Health Sciences, Radboud University Medical Center, The Netherlands
| | - Dick H J Thijssen
- Radboud Institute for Health Sciences, Radboud University Medical Center, The Netherlands; Research Institute for Sport and Exercise Sciences, Liverpool John Moores University, Liverpool, United Kingdom.
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Davis CA, Zambrano S, Anumolu P, Allen ACB, Sonoqui L, Moreno MR. Device-Based In Vitro Techniques for Mechanical Stimulation of Vascular Cells: A Review. J Biomech Eng 2015; 137:040801. [DOI: 10.1115/1.4029016] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2013] [Accepted: 11/07/2014] [Indexed: 01/19/2023]
Abstract
The most common cause of death in the developed world is cardiovascular disease. For decades, this has provided a powerful motivation to study the effects of mechanical forces on vascular cells in a controlled setting, since these cells have been implicated in the development of disease. Early efforts in the 1970 s included the first use of a parallel-plate flow system to apply shear stress to endothelial cells (ECs) and the development of uniaxial substrate stretching techniques (Krueger et al., 1971, “An in Vitro Study of Flow Response by Cells,” J. Biomech., 4(1), pp. 31–36 and Meikle et al., 1979, “Rabbit Cranial Sutures in Vitro: A New Experimental Model for Studying the Response of Fibrous Joints to Mechanical Stress,” Calcif. Tissue Int., 28(2), pp. 13–144). Since then, a multitude of in vitro devices have been designed and developed for mechanical stimulation of vascular cells and tissues in an effort to better understand their response to in vivo physiologic mechanical conditions. This article reviews the functional attributes of mechanical bioreactors developed in the 21st century, including their major advantages and disadvantages. Each of these systems has been categorized in terms of their primary loading modality: fluid shear stress (FSS), substrate distention, combined distention and fluid shear, or other applied forces. The goal of this article is to provide researchers with a survey of useful methodologies that can be adapted to studies in this area, and to clarify future possibilities for improved research methods.
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Affiliation(s)
- Caleb A. Davis
- Department of Biomedical Engineering, Texas A&M University, College Station, TX 77843-3120 e-mail:
| | - Steve Zambrano
- Department of Biomedical Engineering, Texas A&M University, College Station, TX 77843-3120 e-mail:
| | - Pratima Anumolu
- Department of Biomedical Engineering, Texas A&M University, College Station, TX 77843-3120 e-mail:
| | - Alicia C. B. Allen
- Department of Biomedical Engineering, The University of Texas at Austin, Austin, TX 78712-1801 e-mail:
| | - Leonardo Sonoqui
- Department of Biomedical Engineering, Texas A&M University, College Station, TX 77843-3120 e-mail:
| | - Michael R. Moreno
- Department of Mechanical Engineering, Department of Biomedical Engineering, Texas A&M University, College Station, TX 77843-3123 e-mail:
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Impact of handgrip exercise intensity on brachial artery flow-mediated dilation. Eur J Appl Physiol 2015; 115:1705-13. [PMID: 25805181 DOI: 10.1007/s00421-015-3157-1] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2014] [Accepted: 03/17/2015] [Indexed: 01/22/2023]
Abstract
PURPOSE Previous studies that have examined the impact of exercise intensity on conduit artery endothelial function have involved large muscle group exercise which induces local and systemic effects. The aim of this study was to examine flow-mediated dilation (FMD) before and after incremental intensities of handgrip exercise (HE), to assess the role of local factors such as blood flow and shear rate on post-exercise brachial artery function. METHODS Eleven healthy men attended the laboratory on three occasions. Subjects undertook 30 min of handgrip exercise at three intensities (5, 10 or 15 % MVC). Brachial artery FMD, shear and blood flow patterns were examined before, immediately after and 60 min post exercise. RESULTS Handgrip exercise increased mean and antegrade shear rate (SR) and blood flow (BF) and reduced retrograde SR and BF (all P < 0.01). Exercise intensity was associated with a dose-dependent increase in both mean and antegrade BF and SR (interaction, P < 0.01). Post-hoc tests revealed that, whilst handgrip exercise did not immediately induce post-exercise changes, FMD was significantly higher 60 min post-exercise following the highest exercise intensity (5.9 ± 2.8-10.4 ± 5.8 %, P = 0.01). CONCLUSIONS Handgrip exercise leads to intensity-and time-dependent changes in conduit artery function, possibly mediated by local increases in shear, with improvement in function evident at 1 h post-exercise when performed at a higher intensity.
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Qin WD, Mi SH, Li C, Wang GX, Zhang JN, Wang H, Zhang F, Ma Y, Wu DW, Zhang M. Low shear stress induced HMGB1 translocation and release via PECAM-1/PARP-1 pathway to induce inflammation response. PLoS One 2015; 10:e0120586. [PMID: 25793984 PMCID: PMC4368774 DOI: 10.1371/journal.pone.0120586] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2012] [Accepted: 02/10/2015] [Indexed: 11/19/2022] Open
Abstract
Low shear stress (LSS) plays a critical role in the site predilection of atherosclerosis through activation of cellular mechanosensors, such as platelet endothelial cell adhesion molecule 1 (PECAM-1). Poly(ADP-ribose) polymerase 1 (PARP-1) is a nuclear enzyme that regulates the expression of various inflammatory cytokines. The nuclear enzyme high mobility group box 1 (HMGB1) can induce inflammation response by binding to toll-like receptor 4 (TLR4). In the present study, we aimed to investigate the role and mechanism of HMGB1 in LSS induced inflammation in human umbilical vein endothelial cells (HUVECs). HUVECs were stimulated by undisturbed shear stress (USS, 1 Pa) and LSS (0.4 Pa) in our experiments. Gene expression was inhibited by small interfering RNA (siRNA). ICAM-1 expression was regulated by LSS in a time dependent manner. LSS can induce HMGB1 translocation from nucleus to cytoplasm and release. Compared with the USS, LSS could increase the protein expression of PECAM-1 and PARP-1 as well as the secretion of TNF-α and IL-1β. LSS induced the translocation of HMGB1 from nucleus to cytoplasm. Inhibition of HGMB1 reduced LSS-induced inflammatory response. Inhibition of PARP-1 suppressed inflammatory response through inhibiting TLR4 expression and HMGB1 translocation. PECAM-1 inhibition reduced LSS-induced ICAM-1 expression, TNF-α and IL-1β secretion, and monocytes adhesion. LSS can induce inflammatory response via PECAM-1/PARP-1/HMGB1 pathway. PARP-1 plays a fundamental role in HMGB1 translocation and TLR4 expression. Inhibition of PARP-1 may shed light on the treatment of HMGB1 involved inflammation during atherosclerosis.
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Affiliation(s)
- Wei-dong Qin
- The Department of Critical Care Unit, Qilu Hospital of Shandong University, Jinan, Shandong, China
| | - Shao-hua Mi
- The Department of Cardiology, Yu Huang Ding Hospital, Yantai, Shandong, China,
| | - Chen Li
- The Department of Critical Care Unit, Qilu Hospital of Shandong University, Jinan, Shandong, China
| | - Gui-xia Wang
- The Department of Radiology, Linyi People’s Hospital, Linyi, Shandong, China
| | - Jian-ning Zhang
- The Department of Critical Care Unit, Qilu Hospital of Shandong University, Jinan, Shandong, China
| | - Hao Wang
- The Department of Critical Care Unit, Qilu Hospital of Shandong University, Jinan, Shandong, China
| | - Fan Zhang
- The Department of Critical Care Unit, Qilu Hospital of Shandong University, Jinan, Shandong, China
| | - Yang Ma
- The Department of Critical Care Unit, Qilu Hospital of Shandong University, Jinan, Shandong, China
| | - Da-wei Wu
- The Department of Critical Care Unit, Qilu Hospital of Shandong University, Jinan, Shandong, China
| | - Mingxiang Zhang
- The Key Laboratory of Cardiovascular Remodeling and Function Research, Chinese Ministry of Education and Chinese Ministry of Public Health, Qilu Hospital of Shandong University, Jinan, Shandong, China
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Alexy T, Pais E, Wenby RB, Mack WJ, Hodis HN, Kono N, Wang J, Baskurt OK, Fisher TC, Meiselman HJ. Abnormal blood rheology and chronic low grade inflammation: possible risk factors for accelerated atherosclerosis and coronary artery disease in Lewis negative subjects. Atherosclerosis 2015; 239:248-51. [PMID: 25626016 DOI: 10.1016/j.atherosclerosis.2015.01.015] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/20/2014] [Revised: 01/11/2015] [Accepted: 01/13/2015] [Indexed: 11/17/2022]
Abstract
OBJECTIVE To test the hypothesis that abnormal hemorheology and chronic low-grade inflammation are more prevalent in Lewis negative individuals, possibly contributing to premature atherosclerosis. METHODS AND RESULTS We enrolled 223 healthy subjects (154 females, mean age: 64yrs). Conventional risk factors, markers of inflammation and hemorheological profiles were measured; Lewis blood group was determined by serology. Conventional risk factors (age, gender, BMI, blood pressure, lipid profile, smoking habit) did not differ among Lewis phenotypes. However, markers of inflammation (WBC, hs-CRP, ESR) were significantly elevated and rheological parameters (RBC aggregation, plasma viscosity) were abnormal in Lewis negative subjects, especially when compared to the Le(a-b+) group. CONCLUSIONS With a prevalence of 33% in select populations, our data support the hypothesis that Le(a-b-) represents a pro-inflammatory phenotype that may contribute to the elevated cardiovascular risk in this group.
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Affiliation(s)
- Tamas Alexy
- University of Southern California, Keck School of Medicine, Los Angeles, CA 90033, USA; Emory University, School of Medicine, Atlanta, GA 30322, USA.
| | - Eszter Pais
- University of Southern California, Keck School of Medicine, Los Angeles, CA 90033, USA
| | - Rosalinda B Wenby
- University of Southern California, Keck School of Medicine, Los Angeles, CA 90033, USA
| | - Wendy J Mack
- University of Southern California, Keck School of Medicine, Los Angeles, CA 90033, USA
| | - Howard N Hodis
- University of Southern California, Keck School of Medicine, Los Angeles, CA 90033, USA
| | - Naoko Kono
- University of Southern California, Keck School of Medicine, Los Angeles, CA 90033, USA
| | - Jun Wang
- University of Southern California, Keck School of Medicine, Los Angeles, CA 90033, USA
| | | | - Timothy C Fisher
- University of Southern California, Keck School of Medicine, Los Angeles, CA 90033, USA
| | - Herbert J Meiselman
- University of Southern California, Keck School of Medicine, Los Angeles, CA 90033, USA
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Okada R, Okada A, Okada T, Nanasato M, Wakai K. Visit-to-visit blood pressure variability is a marker of cardiac diastolic function and carotid atherosclerosis. BMC Cardiovasc Disord 2014; 14:188. [PMID: 25510736 PMCID: PMC4273455 DOI: 10.1186/1471-2261-14-188] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2014] [Accepted: 12/11/2014] [Indexed: 01/20/2023] Open
Abstract
Background The associations between visit-to-visit blood pressure (BP) variability and cardiac function and carotid atherosclerosis is not clear. Methods Study subjects were 144 subjects (80 were female, aged 73 ± 9 years) who underwent echocardiography and cervical ultrasonography. The ratio of early ventricular filling velocity to early diastolic mitral annular velocity (E/e’), ejection fraction, left ventricular mass index (LVMI), and maximum intima-media thickness (max-IMT) of the carotid artery were compared between the highest (high variability) and lowest (low variability) tertiles of the standard deviation of systolic BP (9.9 ± 3.5 mmHg). Results E/e’ and max-IMT were significantly greater in the high variability group than in the low variability group after adjusting for age, sex, baseline systolic BP, and other covariates (high variability vs. low variability; E/e’: 13.03 ± 5.33 vs. 10.66 ± 3.30, multivariate-adjusted difference (β) = 1.82, 95% confidence interval 0.06–3.58; max-IMT: 1.65 ± 0.43 mm vs. 1.42 ± 0.46 mm, β = 0.20 mm, 95% confidence interval 0.03–0.36 mm). There were no significant differences in LVMI or ejection fraction. Conclusion These results indicate that high visit-to-visit BP variability is associated with diastolic function and carotid atherosclerosis, and is a possible risk factor for diastolic dysfunction and atherosclerosis.
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Affiliation(s)
- Rieko Okada
- Department of Preventive Medicine, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya 466-8550, Japan.
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Sun Z, Xu L. Computational fluid dynamics in coronary artery disease. Comput Med Imaging Graph 2014; 38:651-63. [PMID: 25262321 DOI: 10.1016/j.compmedimag.2014.09.002] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2014] [Revised: 08/22/2014] [Accepted: 09/03/2014] [Indexed: 01/01/2023]
Abstract
Computational fluid dynamics (CFD) is a widely used method in mechanical engineering to solve complex problems by analysing fluid flow, heat transfer, and associated phenomena by using computer simulations. In recent years, CFD has been increasingly used in biomedical research of coronary artery disease because of its high performance hardware and software. CFD techniques have been applied to study cardiovascular haemodynamics through simulation tools to predict the behaviour of circulatory blood flow in the human body. CFD simulation based on 3D luminal reconstructions can be used to analyse the local flow fields and flow profiling due to changes of coronary artery geometry, thus, identifying risk factors for development and progression of coronary artery disease. This review aims to provide an overview of the CFD applications in coronary artery disease, including biomechanics of atherosclerotic plaques, plaque progression and rupture; regional haemodynamics relative to plaque location and composition. A critical appraisal is given to a more recently developed application, fractional flow reserve based on CFD computation with regard to its diagnostic accuracy in the detection of haemodynamically significant coronary artery disease.
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Affiliation(s)
- Zhonghua Sun
- Discipline of Medical Imaging, Department of Imaging and Applied Physics, Curtin University, Perth, Western Australia 6845, Australia.
| | - Lei Xu
- Department of Radiology, Beijing Anzhen Hospital, Capital Medical University, Beijing, China.
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Mahler GJ, Frendl CM, Cao Q, Butcher JT. Effects of shear stress pattern and magnitude on mesenchymal transformation and invasion of aortic valve endothelial cells. Biotechnol Bioeng 2014; 111:2326-37. [PMID: 24898772 DOI: 10.1002/bit.25291] [Citation(s) in RCA: 98] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2014] [Revised: 04/18/2014] [Accepted: 05/07/2014] [Indexed: 01/23/2023]
Abstract
Understanding the role of mechanical forces on cell behavior is critical for tissue engineering, regenerative medicine, and disease initiation studies. Current hemodynamic bioreactors are largely limited to 2D substrates or the application of general flow conditions at a tissue level, which eliminates the investigation of some essential physiological and pathological responses. One example is the mesenchymal transformation of endothelial cells in response to shear stress. Endothelial to mesenchymal transformation (EndMT) is a valve morphogenic mechanism associated with aortic valve disease initiation. The aortic valve experiences oscillatory shear on the disease-susceptible fibrosa, and the role of hemodynamics on adult EndMT is unknown. The goal of this work was to develop and characterize a microfluidic bioreactor that applies physiologically relevant laminar or oscillatory shear stresses to endothelial cells and permits the quantitative analysis of 3D cell-extracellular matrix (ECM) interactions. In this study, porcine aortic valve endothelial cells were seeded onto 3D collagen I gels and exposed to different magnitudes of steady or oscillatory shear stress for 48 h. Cells elongated and aligned perpendicular to laminar, but not oscillatory shear. Low steady shear stress (2 dyne/cm(2) ) and oscillatory shear stress upregulated EndMT (ACTA2, Snail, TGFB1) and inflammation (ICAM1, NFKB1) related gene expression, EndMT-related (αSMA) protein expression, and matrix invasion when compared with static controls or cells exposed to high steady shear (10 and 20 dyne/cm(2) ). Our system enables direct testing of the role of shear stress on endothelial cell mesenchymal transformation in a dynamic, 3D environment and shows that hemodynamics regulate EndMT in adult valve endothelial cells.
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Affiliation(s)
- Gretchen J Mahler
- Department of Biomedical Engineering, Cornell University, Ithaca, New York; Department of Bioengineering, Binghamton University, Binghamton, New York
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Barbaro NR, Fontana V, Modolo R, De Faria AP, Sabbatini AR, Fonseca FH, Anhê GF, Moreno H. Increased arterial stiffness in resistant hypertension is associated with inflammatory biomarkers. Blood Press 2014; 24:7-13. [PMID: 25061978 DOI: 10.3109/08037051.2014.940710] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
BACKGROUND Increased levels of inflammatory biomarkers such as interleukin-6 (IL-6), 10 (IL-10), 1β (IL-1β), tumor necrosis factor-α (TNF-α) high-sensitivity C-reactive protein (hs-CRP) are associated with arterial stiffness in hypertension. Indeed, resistant hypertension (RHTN) leads to unfavorable prognosis attributed to poor blood pressure (BP) control and target organ damage. This study evaluated the potential impact of inflammatory biomarkers on arterial stiffness in RHTN. METHODS In this cross-sectional study, 32 RHTN, 20 mild hypertensive (HTN) and 20 normotensive (NT) patients were subjected to office BP and arterial stiffness measurements assessed by pulse wave velocity (PWV). Inflammatory biomarkers were measured in plasma samples. RESULTS PWV was increased in RHTN compared with HTN and NT (p < 0.05). TNF-α levels were significantly higher in RHTN and HTN than NT patients. No differences in IL-6 levels were observed. RHTN patients had a higher frequency of subjects with increased levels of IL-10 and IL-1β compared with HTN and NT patients. Finally, IL-1β was independently associated with PWV (p < 0.001; R(2) = 0.5; β = 0.077). CONCLUSION RHTN subjects have higher levels of inflammatory cytokines (TNF-α, IL-1β and IL-10) as well as increased arterial stiffness, and detectable IL-1β levels are associated arterial stiffness. These findings suggest that inflammation plays a possible role in the pathophysiology of RHTN.
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Affiliation(s)
- Natália Ruggeri Barbaro
- Laboratory of Cardiovascular Pharmacology, Faculty of Medical Sciences, University of Campinas (Unicamp) , Campinas , Brazil
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Martorell J, Santomá P, Kolandaivelu K, Kolachalama VB, Melgar-Lesmes P, Molins JJ, Garcia L, Edelman ER, Balcells M. Extent of flow recirculation governs expression of atherosclerotic and thrombotic biomarkers in arterial bifurcations. Cardiovasc Res 2014; 103:37-46. [PMID: 24841070 PMCID: PMC4670884 DOI: 10.1093/cvr/cvu124] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/12/2013] [Revised: 04/10/2014] [Accepted: 05/01/2014] [Indexed: 11/12/2022] Open
Abstract
AIMS Atherogenesis, evolution of plaque, and outcomes following endovascular intervention depend heavily on the unique vascular architecture of each individual. Patient-specific, multiscale models able to correlate changes in microscopic cellular responses with relevant macroscopic flow, and structural conditions may help understand the progression of occlusive arterial disease, providing insights into how to mitigate adverse responses in specific settings and individuals. METHODS AND RESULTS Vascular architectures mimicking coronary and carotid bifurcations were derived from clinical imaging and used to generate conjoint computational meshes for in silico analysis and biocompatible scaffolds for in vitro models. In parallel with three-dimensional flow simulations, geometrically realistic scaffolds were seeded with human smooth muscle cells (SMC) or endothelial cells and exposed to relevant, physiological flows. In vitro surrogates of endothelial health, atherosclerotic progression, and thrombosis were locally quantified and correlated best with an quantified extent of flow recirculation occurring within the bifurcation models. Oxidized low-density lipoprotein uptake, monocyte adhesion, and tissue factor expression locally rose up to three-fold, and phosphorylated endothelial nitric oxide synthase and Krüppel-like factor 2 decreased up to two-fold in recirculation areas. Isolated testing in straight-tube idealized constructs subject to static, oscillatory, and pulsatile conditions, indicative of different recirculant conditions corroborated these flow-mediated dependencies. CONCLUSIONS Flow drives variations in vascular reactivity and vascular beds. Endothelial health was preserved by arterial flow but jeopardized in regions of flow recirculation in a quasi-linear manner. Similarly, SMC exposed to flow were more thrombogenic in large recirculating regions. Health, thrombosis, and atherosclerosis biomarkers correlate with the extent of recirculation in vascular cells lining certain vascular geometries.
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Affiliation(s)
- Jordi Martorell
- Institute for Medical Engineering and Science, Massachusetts Institute of Technology, Cambridge, MA, USA Department of Chemical Engineering, IQS School of Engineering, URL, Via Augusta 390, 08017 Barcelona, Spain
| | - Pablo Santomá
- Institute for Medical Engineering and Science, Massachusetts Institute of Technology, Cambridge, MA, USA Department of Chemical Engineering, IQS School of Engineering, URL, Via Augusta 390, 08017 Barcelona, Spain
| | - Kumaran Kolandaivelu
- Institute for Medical Engineering and Science, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Vijaya B Kolachalama
- Institute for Medical Engineering and Science, Massachusetts Institute of Technology, Cambridge, MA, USA Charles Stark Draper Laboratory, Cambridge, MA, USA
| | - Pedro Melgar-Lesmes
- Institute for Medical Engineering and Science, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - José J Molins
- Department of Chemical Engineering, IQS School of Engineering, URL, Via Augusta 390, 08017 Barcelona, Spain
| | - Lawrence Garcia
- Department of Interventional Cardiology and Vascular Medicine, St. Elizabeth's Medical Center, Boston, MA, USA
| | - Elazer R Edelman
- Institute for Medical Engineering and Science, Massachusetts Institute of Technology, Cambridge, MA, USA Cardiovascular Division, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
| | - Mercedes Balcells
- Institute for Medical Engineering and Science, Massachusetts Institute of Technology, Cambridge, MA, USA Department of Biological Engineering, IQS School of Engineering, URL, Barcelona, Spain
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Wang J, Liu L, Xia Y, Wu D. Silencing of poly(ADP-ribose) polymerase-1 suppresses hyperstretch-induced expression of inflammatory cytokines in vitro. Acta Biochim Biophys Sin (Shanghai) 2014; 46:556-64. [PMID: 24829399 DOI: 10.1093/abbs/gmu035] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
In addition to biochemical stimuli, physical forces also play a critical role in regulating the structure, function, and metabolism of the lung. Hyperstretch can induce the inflammatory responses in asthma, but the mechanism remains unclear. Poly(ADP-ribose) polymerase-1 (PARP-1) is a nuclear enzyme that can regulate a variety of inflammatory cytokines expression. In the present study, we aimed to investigate the role and mechanism of PARP-1 in mechanical stretch-induced inflammation in human bronchial epithelial cells (HBEpiCs). HBEpiCs were simulated by mechanical stretch and cells under static were used as the control. PARP-1 expression was interfered by small interfering RNA. Oxidative stress was evaluated by DHE staining. DNA damage was assessed by comet assay. The results showed that interleukin-8 (IL-8) and vascular cell adhesion molecule-1 (VCAM-1) expression were regulated by hyperstretch in a time-dependent manner. Hyperstretch could increase PARP-1 expression and activity by inducing superoxide production and DNA damage. Silencing of PARP-1 attenuated hyperstretch-induced IL-8 and VCAM-1 up-regulation as well as monocytes adhesion, which were related to the inhibition of nuclear factor-kappa B (NF-κB) translocation. Our study showed that hyperstretch could induce inflammatory response and superoxide production as well as DNA damage in HBEpiCs. PARP-1 silencing decreased IL-8 and VCAM-1 expression, partly through inhibition of NF-κB translocation. PARP-1 played a fundamental role in hyperstretch-induced inflammation. PARP-1 silencing could be used as a potential therapeutic approach to reverse bronchial epithelial inflammation in asthma.
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Affiliation(s)
- Jing Wang
- Department of Intensive Care Unit, Qilu Hospital of Shandong University, Jinan 250012, China Department of Intensive Care Unit, Yu Huang Ding Hospital, Yantai 264000, China
| | - Luyi Liu
- Department of Intensive Care Unit, Yu Huang Ding Hospital, Yantai 264000, China
| | - Yonghong Xia
- Department of Intensive Care Unit, Yu Huang Ding Hospital, Yantai 264000, China
| | - Dawei Wu
- Department of Intensive Care Unit, Qilu Hospital of Shandong University, Jinan 250012, China
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Swanson TA, Conte T, Deeley B, Portugal S, Kreeger JM, Obert LA, Joseph EC, Wisialowski TA, Sokolowski SA, Rief C, Nugent P, Lawton MP, Enerson BE. Hemodynamic Correlates of Drug-induced Vascular Injury in the Rat Using High-frequency Ultrasound Imaging. Toxicol Pathol 2014; 42:784-91. [DOI: 10.1177/0192623314525687] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Several classes of drugs have been shown to cause drug-induced vascular injury (DIVI) in preclinical toxicity studies. Measurement of blood flow and vessel diameter in numerous vessels and across various tissues by ultrasound imaging has the potential to be a noninvasive translatable biomarker of DIVI. Our objective was to demonstrate the utility of high-frequency ultrasound imaging for measuring changes in vascular function by evaluating blood flow and vessel diameter in the superior mesenteric arteries (SMA) of rats treated with compounds that are known to cause DIVI and are known vasodilators in rat: fenoldopam, CI-1044, and SK&F 95654. Blood flow, vessel diameter, and other parameters were measured in the SMA at 4, 8, and 24 hr after dosing. Mild to moderate perivascular accumulations of mononuclear cells, neutrophils in tunica adventitia, and superficial tunica media as well as multifocal hemorrhage and necrosis in the tunica media were found in animals 24 hr after treatment with fenoldopam and SK&F 95654. Each compound caused marked increases in blood flow and shear stress as early as 4 hr after dosing. These results suggest that ultrasound imaging may constitute a functional correlate for the microscopic finding of DIVI in the rat.
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Affiliation(s)
- Terri A. Swanson
- Pfizer Worldwide Research and Development, Groton, Connecticut, USA
| | - Teri Conte
- FUJIFILM VisualSonics, Inc., Toronto, Ontario, Canada
| | - Ben Deeley
- FUJIFILM VisualSonics, Inc., Toronto, Ontario, Canada
| | - Susan Portugal
- Pfizer Worldwide Research and Development, Groton, Connecticut, USA
| | - John M. Kreeger
- Pfizer Worldwide Research and Development, Groton, Connecticut, USA
| | - Leslie A. Obert
- Pfizer Worldwide Research and Development, Groton, Connecticut, USA
| | - E. Clive Joseph
- Pfizer Worldwide Research and Development, Groton, Connecticut, USA
| | | | | | - Catherine Rief
- Pfizer Worldwide Research and Development, Andover, Massachusetts, USA
| | - Paul Nugent
- Pfizer Worldwide Research and Development, Groton, Connecticut, USA
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Liu Y, Liu Y, Wang P, Tian H, Ai J, Liu Y, Zhou Y, Liu Z, Guo W, Yang S. Autologous bone marrow stem cell transplantation for the treatment of postoperative hand infection with a skin defect in diabetes mellitus: A case report. Oncol Lett 2014; 7:1857-1862. [PMID: 24932248 PMCID: PMC4049741 DOI: 10.3892/ol.2014.1998] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2013] [Accepted: 02/07/2014] [Indexed: 02/05/2023] Open
Abstract
Among stem cells, autologous mesenchymal stem cells (MSCs) are ideal for transplantation by virtue of limited rejection reactions and marked proliferative ability. This study presents a novel method by which MSCs were harvested from the bone marrow of a patient who presented with severe post-traumatic infection and a non-healing skin defect in the hand, secondary to uncontrolled diabetes mellitus (DM). An autologous MSC suspension was injected into the persistent skin defect after stabilizing the blood glucose level and appropriate infection control. During the course of a regular 18-month postoperative follow-up, the patient exhibited immediate recovery with no transplant-associated complications, as well as no evidence of tumorigenicity. Thus, transplantation of autologous MSCs may play a role in the clinical application of stem cells, particularly for treatment of skin defects following surgery in cases of DM and for those caused by various other traumas.
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Affiliation(s)
- Yihong Liu
- Department of Endocrinology and Metabolism, West China Hospital, West China Medical School, Sichuan University, Chengdu, Sichuan 610041, P.R. China ; Diabetic Centre of Control and Prevention, The People's Liberation Army 520 Hospital, Mianyang, Sichuan 621000, P.R. China
| | - Yuchen Liu
- Diabetic Centre of Control and Prevention, The People's Liberation Army 520 Hospital, Mianyang, Sichuan 621000, P.R. China
| | - Pujie Wang
- Diabetic Centre of Control and Prevention, The People's Liberation Army 520 Hospital, Mianyang, Sichuan 621000, P.R. China
| | - Haoming Tian
- Department of Endocrinology and Metabolism, West China Hospital, West China Medical School, Sichuan University, Chengdu, Sichuan 610041, P.R. China
| | - Jianzhong Ai
- Core Facility of Genetically Engineered Mice, State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, West China Medical School, Sichuan University, Chengdu, Sichuan 610041, P.R. China
| | - Yangbo Liu
- Diabetic Centre of Control and Prevention, The People's Liberation Army 520 Hospital, Mianyang, Sichuan 621000, P.R. China
| | - Yi Zhou
- Diabetic Centre of Control and Prevention, The People's Liberation Army 520 Hospital, Mianyang, Sichuan 621000, P.R. China
| | - Zhongwen Liu
- Diabetic Centre of Control and Prevention, The People's Liberation Army 520 Hospital, Mianyang, Sichuan 621000, P.R. China
| | - Wenjun Guo
- Diabetic Centre of Control and Prevention, The People's Liberation Army 520 Hospital, Mianyang, Sichuan 621000, P.R. China
| | - Shenke Yang
- Diabetic Centre of Control and Prevention, The People's Liberation Army 520 Hospital, Mianyang, Sichuan 621000, P.R. China
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129
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Liu FY, Liu XY, Zhang LJ, Cheng YP, Jiang YN. Binding of prorenin to (pro)renin receptor induces the proliferation of human umbilical artery smooth muscle cells via ROS generation and ERK1/2 activation. J Renin Angiotensin Aldosterone Syst 2014; 15:99-108. [PMID: 24591529 DOI: 10.1177/1470320314525215] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
INTRODUCTION Since the discovery of the (pro)renin receptor (PRR), it has been considered as a novel bioactive molecule of the renin-angiotensin system (RAS). The activation of PRR can elicit a series of angiotensin II (AngII)-independent effects. MATERIALS AND METHODS In this study, we investigated the effects of prorenin and PRR on the proliferation of human umbilical artery smooth muscle (HUASM) cells and explored the possible mechanisms underlying these effects. RESULTS The binding of prorenin to PRR can promote proliferation and upregulate the anti-apoptotic protein Bcl-2 and downregulate the pro-apoptotic protein Bax independently of AngII in HUASM cells. In addition, the binding of prorenin to PRR can also increase the production of reactive oxygen species (ROS) and the phosphorylation of extracellular signal-regulated kinase (ERK1/2) independently of AngII. The pretreatment of HUASM cells with an NADPH oxidase inhibitor DPI decreased the production of ROS and also decreased the phosphorylation of ERK1/2. Furthermore, pretreatment of HUASM cells with DPI and the ERK1/2 inhibitor PD98059 significantly attenuated the prorenin-induced proliferation and regulation of apoptosis factors. CONCLUSION Binding of prorenin to PRR can induce HUASM cell proliferation via the ROS generation and ERK1/2 activation.
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Affiliation(s)
- Feng Y Liu
- Dalian Medical University, Dalian, PR China
| | - Xiao Y Liu
- Dalian Medical University, Dalian, PR China
| | - Li J Zhang
- Dalian Medical University, Dalian, PR China
| | - Yun P Cheng
- Department of Cardiology, The First Affiliated Hospital of Dalian Medical University, Dalian, PR China
| | - Yi N Jiang
- Department of Cardiology, The First Affiliated Hospital of Dalian Medical University, Dalian, PR China
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130
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The relationship between the 24 h blood pressure variability and carotid intima-media thickness: a compared study. COMPUTATIONAL AND MATHEMATICAL METHODS IN MEDICINE 2014; 2014:303159. [PMID: 24660021 PMCID: PMC3934393 DOI: 10.1155/2014/303159] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/19/2013] [Revised: 12/17/2013] [Accepted: 12/24/2013] [Indexed: 11/29/2022]
Abstract
Large blood pressure variability (BPV) will not only harm the target organ but also increase the possibility of the cardiovascular events. Since the damage of vascular system always leads to the alteration of the carotid wall, the structure and function of the carotid artery have been extensively examined in previous studies. In this work we conduct a study (60 subjects, aged 33–79) to evaluate the relationship between BPV and carotid intima-media thickness (IMT) in Shenzhen, which is one large city in the southern area of China. In our study, the blood pressure (BP) was collected using the 24 h ambulatory BP monitoring, and the BPV was evaluated using standard deviation (SD), coefficient of variation (CV), and average real variability (ARV) during 24 h, daytime and nighttime. All the IMT measurements are collected by ultrasound. The results show that both the daytime, and 24 h systolic BPV evaluated by three indices are positively associated with IMT. Among them, daytime systolic BPV evaluated with ARV is the best variable to represent the increasing of carotid IMT. In addition, after adjusting by age, sex, smoking, hypertension, and mean BP and PP values, 24 h diastolic BPV evaluated with SD also presents the favorable performance.
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131
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Spindel ON, Burke RM, Yan C, Berk BC. Thioredoxin-interacting protein is a biomechanical regulator of Src activity: key role in endothelial cell stress fiber formation. Circ Res 2014; 114:1125-32. [PMID: 24515523 DOI: 10.1161/circresaha.114.301315] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
RATIONALE Fluid shear stress differentially regulates endothelial cell stress fiber formation with decreased stress fibers in areas of disturbed flow compared with steady flow areas. Importantly, stress fibers are critical for several endothelial cell functions including cell shape, mechano-signal transduction, and endothelial cell-cell junction integrity. A key mediator of steady flow-induced stress fiber formation is Src that regulates downstream signaling mediators such as phosphorylation of cortactin, activity of focal adhesion kinase, and small GTPases. OBJECTIVE Previously, we showed that thioredoxin-interacting protein (TXNIP, also VDUP1 [vitamin D upregulated protein 1] and TBP-2 [thioredoxin binding protein 2]) was regulated by fluid shear stress; TXNIP expression was increased in disturbed flow compared with steady flow areas. Although TXNIP was originally characterized for its role in redox and metabolic cellular functions, recent reports show important scaffold functions related to its α-arrestin structure. Based on these findings, we hypothesized that TXNIP acts as a biomechanical sensor that regulates Src kinase activity and stress fiber formation. METHODS AND RESULTS Using en face immunohistochemistry of the aorta and cultured endothelial cells, we show inverse relationship between TXNIP expression and Src activity. Specifically, steady flow increased Src activity and stress fiber formation, whereas it decreased TXNIP expression. In contrast, disturbed flow had opposite effects. We studied the role of TXNIP in regulating Src homology phosphatase-2 plasma membrane localization and vascular endothelial cadherin binding because Src homology phosphatase-2 indirectly regulates dephosphorylation of Src tyrosine 527 that inhibits Src activity. Using immunohistochemistry and immunoprecipitation, we found that TXNIP prevented Src homology phosphatase-2-vascular endothelial cadherin interaction. CONCLUSIONS In summary, these data characterize a fluid shear stress-mediated mechanism for stress fiber formation that involves a TXNIP-dependent vascular endothelial cadherin-Src homology phosphatase-2-Src pathway.
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Affiliation(s)
- Oded N Spindel
- From the Departments of Medicine (O.N.S., R.M.B., C.Y., B.C.B.) and Pharmacology and Physiology (O.N.S., C.Y., B.C.B.), University of Rochester School of Medicine and Dentistry, Aab Cardiovascular Research Institute, NY
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132
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Hsieh HJ, Liu CA, Huang B, Tseng AH, Wang DL. Shear-induced endothelial mechanotransduction: the interplay between reactive oxygen species (ROS) and nitric oxide (NO) and the pathophysiological implications. J Biomed Sci 2014; 21:3. [PMID: 24410814 PMCID: PMC3898375 DOI: 10.1186/1423-0127-21-3] [Citation(s) in RCA: 197] [Impact Index Per Article: 19.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2013] [Accepted: 01/02/2014] [Indexed: 12/26/2022] Open
Abstract
Hemodynamic shear stress, the blood flow-generated frictional force acting on the vascular endothelial cells, is essential for endothelial homeostasis under normal physiological conditions. Mechanosensors on endothelial cells detect shear stress and transduce it into biochemical signals to trigger vascular adaptive responses. Among the various shear-induced signaling molecules, reactive oxygen species (ROS) and nitric oxide (NO) have been implicated in vascular homeostasis and diseases. In this review, we explore the molecular, cellular, and vascular processes arising from shear-induced signaling (mechanotransduction) with emphasis on the roles of ROS and NO, and also discuss the mechanisms that may lead to excessive vascular remodeling and thus drive pathobiologic processes responsible for atherosclerosis. Current evidence suggests that NADPH oxidase is one of main cellular sources of ROS generation in endothelial cells under flow condition. Flow patterns and magnitude of shear determine the amount of ROS produced by endothelial cells, usually an irregular flow pattern (disturbed or oscillatory) producing higher levels of ROS than a regular flow pattern (steady or pulsatile). ROS production is closely linked to NO generation and elevated levels of ROS lead to low NO bioavailability, as is often observed in endothelial cells exposed to irregular flow. The low NO bioavailability is partly caused by the reaction of ROS with NO to form peroxynitrite, a key molecule which may initiate many pro-atherogenic events. This differential production of ROS and RNS (reactive nitrogen species) under various flow patterns and conditions modulates endothelial gene expression and thus results in differential vascular responses. Moreover, ROS/RNS are able to promote specific post-translational modifications in regulatory proteins (including S-glutathionylation, S-nitrosylation and tyrosine nitration), which constitute chemical signals that are relevant in cardiovascular pathophysiology. Overall, the dynamic interplay between local hemodynamic milieu and the resulting oxidative and S-nitrosative modification of regulatory proteins is important for ensuing vascular homeostasis. Based on available evidence, it is proposed that a regular flow pattern produces lower levels of ROS and higher NO bioavailability, creating an anti-atherogenic environment. On the other hand, an irregular flow pattern results in higher levels of ROS and yet lower NO bioavailability, thus triggering pro-atherogenic effects.
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Affiliation(s)
| | | | | | | | - Danny Ling Wang
- Institute of Biomedical Sciences, Academia Sinica, Taipei 11529, Taiwan.
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133
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Schreuder THA, Green DJ, Hopman MTE, Thijssen DHJ. Acute impact of retrograde shear rate on brachial and superficial femoral artery flow-mediated dilation in humans. Physiol Rep 2014; 2:e00193. [PMID: 24744872 PMCID: PMC3967676 DOI: 10.1002/phy2.193] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2013] [Revised: 11/25/2013] [Accepted: 12/02/2013] [Indexed: 01/22/2023] Open
Abstract
Retrograde shear rate (SR) in the brachial artery (BA) is associated with endothelial dysfunction; a precursor to atherosclerosis. The BA does not typically manifest clinical atherosclerosis, whereas the superficial femoral artery (SFA) is more prone to developing plaque. Examine whether the impact of incremental levels of retrograde SR differs between atherosclerosis-prone (i.e., SFA) and -resistant vessels (i.e., BA) in healthy men. Thirteen healthy young men reported three times to the laboratory. We examined BA flow-mediated dilation (FMD) before and after 30-min exposure to cuff inflation around the forearm at 0, 30, and 60 mmHg, to manipulate retrograde SR. Subsequently, the 30-min intervention was repeated in the SFA, using the same cuff pressure as in the forearm. Order of testing (vessel and intervention) was randomized among subjects. We found a dose-dependent increase in retrograde SR with 30 and 60 mmHg cuff inflation, which was present in both the BA and SFA (all P < 0.05). BA and SFA FMD decreased after the 30-min intervention ("time": P = 0.012), and this was dependent on cuff pressure ("cuff × time": P = 0.024). A significant decrease in FMD was observed after 60 mmHg only and this change was similarly present in both arteries ("time × artery": P = 0.227). Moreover, the BA and SFA demonstrate a similar relationship between changes in retrograde SR and FMD (r = 0.498 and 0.475, respectively). Our study demonstrates that acute exposure to an increase in retrograde shear leads to comparable decreases in FMD in atherosclerotic-prone and -resistant conduit arteries in humans.
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Affiliation(s)
- Tim H A Schreuder
- Department of Physiology, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands
| | - Daniel J Green
- Research Institute for Sport and Exercise Science, Liverpool John Moores University, Liverpool, United Kingdom ; School of Sport Science, Exercise and Health, The University of Western Australia, Crawley, Western Australia, Australia
| | - Maria T E Hopman
- Department of Physiology, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands
| | - Dick H J Thijssen
- Department of Physiology, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands ; Research Institute for Sport and Exercise Science, Liverpool John Moores University, Liverpool, United Kingdom
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Tarbell JM, Shi ZD, Dunn J, Jo H. Fluid Mechanics, Arterial Disease, and Gene Expression. ANNUAL REVIEW OF FLUID MECHANICS 2014; 46:591-614. [PMID: 25360054 PMCID: PMC4211638 DOI: 10.1146/annurev-fluid-010313-141309] [Citation(s) in RCA: 93] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
This review places modern research developments in vascular mechanobiology in the context of hemodynamic phenomena in the cardiovascular system and the discrete localization of vascular disease. The modern origins of this field are traced, beginning in the 1960s when associations between flow characteristics, particularly blood flow-induced wall shear stress, and the localization of atherosclerotic plaques were uncovered, and continuing to fluid shear stress effects on the vascular lining endothelial) cells (ECs), including their effects on EC morphology, biochemical production, and gene expression. The earliest single-gene studies and genome-wide analyses are considered. The final section moves from the ECs lining the vessel wall to the smooth muscle cells and fibroblasts within the wall that are fluid me chanically activated by interstitial flow that imposes shear stresses on their surfaces comparable with those of flowing blood on EC surfaces. Interstitial flow stimulates biochemical production and gene expression, much like blood flow on ECs.
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Affiliation(s)
- John M Tarbell
- Department of Biomedical Engineering, The City College of New York, New York, NY 10031
| | - Zhong-Dong Shi
- Developmental Biology Program, Sloan-Kettering Institute, New York, NY 10065
| | - Jessilyn Dunn
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia 30322
| | - Hanjoong Jo
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia 30322
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135
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Huang X, Shen Y, Zhang Y, Wei L, Lai Y, Wu J, Liu X, Liu X. Rac1 mediates laminar shear stress-induced vascular endothelial cell migration. Cell Adh Migr 2013; 7:462-8. [PMID: 24430179 DOI: 10.4161/cam.27171] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
The migration of endothelial cells (ECs) plays an important role in vascular remodeling and regeneration. ECs are constantly subjected to shear stress resulting from blood flow and are able to convert mechanical stimuli into intracellular signals that affect cellular behaviors and functions. The aim of this study is to elucidate the effects of Rac1, which is the member of small G protein family, on EC migration under different laminar shear stress (5.56, 10.02, and 15.27 dyn/cm(2)). The cell migration distance under laminar shear stress increased significantly than that under the static culture condition. Especially, under relative high shear stress (15.27 dyn/cm(2)) there was a higher difference at 8 h (P<0.01) and 2 h (P<0.05) compared with static controls. RT-PCR results further showed increasing mRNA expression of Rac1 in ECs exposed to laminar shear stress than that exposed to static culture. Using plasmids encoding the wild-type (WT), an activated mutant (Q61L), and a dominant-negative mutant (T17N), plasmids encoding Rac1 were transfected into EA.hy 926 cells. The average net migration distance of Rac1Q61L group increased significantly, while Rac1T17N group decreased significantly in comparison with the static controls. These results indicated that Rac1 mediated shear stress-induced EC migration. Our findings conduce to elucidate the molecular mechanisms of EC migration induced by shear stress, which is expected to understand the pathophysiological basis of wound healing in health and diseases.
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Affiliation(s)
- Xianliang Huang
- Institute of Biomedical Engineering; School of Preclinical and Forensic Medicine; Sichuan University; Chengdu, PR China; Laboratory of Cardiovascular Diseases; West China Hospital; Sichuan University; PR China
| | - Yang Shen
- Institute of Biomedical Engineering; School of Preclinical and Forensic Medicine; Sichuan University; Chengdu, PR China; Laboratory of Cardiovascular Diseases; West China Hospital; Sichuan University; PR China
| | - Yi Zhang
- Laboratory of Biomedical Ultrasonics; Institute of Women and Children's Health; West China Second University Hospital; Sichuan University; Chengdu, PR China
| | - Lin Wei
- Institute of Biomedical Engineering; School of Preclinical and Forensic Medicine; Sichuan University; Chengdu, PR China; Laboratory of Cardiovascular Diseases; West China Hospital; Sichuan University; PR China
| | - Yi Lai
- Institute of Biomedical Engineering; School of Preclinical and Forensic Medicine; Sichuan University; Chengdu, PR China; Laboratory of Cardiovascular Diseases; West China Hospital; Sichuan University; PR China
| | - Jiang Wu
- Institute of Biomedical Engineering; School of Preclinical and Forensic Medicine; Sichuan University; Chengdu, PR China; Laboratory of Cardiovascular Diseases; West China Hospital; Sichuan University; PR China
| | - Xiaojing Liu
- Laboratory of Cardiovascular Diseases; West China Hospital; Sichuan University; PR China
| | - Xiaoheng Liu
- Institute of Biomedical Engineering; School of Preclinical and Forensic Medicine; Sichuan University; Chengdu, PR China; Laboratory of Cardiovascular Diseases; West China Hospital; Sichuan University; PR China
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136
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van Gestel AJR, Clarenbach CF, Stöwhas AC, Rossi VA, Sievi NA, Camen G, Kohler M. The speed of blood pressure fluctuations in patients with chronic obstructive pulmonary disease. Heart Lung Circ 2013; 23:280-6. [PMID: 24080024 DOI: 10.1016/j.hlc.2013.08.010] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2013] [Revised: 08/07/2013] [Accepted: 08/08/2013] [Indexed: 11/28/2022]
Abstract
BACKGROUND Chronic obstructive pulmonary disease (COPD) has been associated with increased risk for cardiovascular disease but mechanisms underlying this association are incompletely understood. The speed of beat-to-beat changes in systolic blood pressure (vSBP) was found to be pronounced in patients with elevated cardiovascular risk. Although increased vSBP may thus be a contributing mechanism to cardiovascular morbidity, no data exist on vSBP in patients with COPD. Therefore, the purpose of this study was to evaluate whether there is an association between severity of COPD and vSBP. METHODS Resting beat-to-beat blood pressure was recorded during 5 min. vSBP was assessed by calculating the slopes of oscillatory fluctuations in SBP for different inter-beat intervals (IBI). Univariate and multivariate analyses were performed to evaluate the association between forced expiratory volume in 1 s (FEV1) and vSBP. RESULTS This study comprised 60 patients with COPD (24 females) with a mean [SD] FEV1 of 45.4 [22.7] %predicted and 34 healthy controls. Short-term fluctuations in SBP were more pronounced in patients with COPD compared to healthy controls. There was a significant inverse correlation between FEV1 and vSBP (r=-0.41, p=0.001). Even after adjustment for covariates in multivariate analysis, FEV1 was found to be independently associated with vSBP. CONCLUSIONS Patients with COPD are characterised by steeper blood pressure changes than healthy controls. The speed of fluctuations in SBP is associated with the severity of airflow limitation. Increased vSBP may be a mechanism underpinning the association between COPD and cardiovascular disease.
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Affiliation(s)
- Arnoldus J R van Gestel
- Pulmonary Division, University Hospital of Zurich, Zurich, Switzerland; Department of Health, Zurich University of Applied Sciences, Winterthur, Switzerland.
| | | | | | - Valentina A Rossi
- Pulmonary Division, University Hospital of Zurich, Zurich, Switzerland.
| | - Noriane A Sievi
- Pulmonary Division, University Hospital of Zurich, Zurich, Switzerland.
| | - Giovanni Camen
- Pulmonary Division, University Hospital of Zurich, Zurich, Switzerland.
| | - Malcolm Kohler
- Pulmonary Division, University Hospital of Zurich, Zurich, Switzerland; Center for Integrative Human Physiology, University of Zurich, Zurich, Switzerland.
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137
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DeVerse JS, Sandhu AS, Mendoza N, Edwards CM, Sun C, Simon SI, Passerini AG. Shear stress modulates VCAM-1 expression in response to TNF-α and dietary lipids via interferon regulatory factor-1 in cultured endothelium. Am J Physiol Heart Circ Physiol 2013; 305:H1149-57. [PMID: 23934855 DOI: 10.1152/ajpheart.00311.2013] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Dyslipidemia is a primary risk factor for cardiovascular disease, but the specific mechanisms that determine the localization of atherosclerotic plaques in arteries are not well defined. Triglyceride-rich lipoproteins (TGRL) isolated from human plasma after a high-fat meal modulate TNF-α-induced VCAM-1 expression in cultured human aortic endothelial cells (HAECs) via an interferon regulatory factor (IRF)-1-dependent transcriptional mechanism. We examined whether fluid shear stress acts as a mediator of IRF-1-dependent VCAM-1 expression in response to cytokine and dietary lipids. IRF-1 and VCAM-1 were examined by immunofluorescence in TNF-α-stimulated HAEC monolayers exposed to TGRL and a linear gradient of shear stress ranging from 0 to 16 dyn/cm(2) in a microfluidic device. Shear stress alone modulated TNF-α-induced VCAM-1 expression, eliciting a 150% increase at low shear stress (2 dyn/cm(2)) and a 70% decrease at high shear stress (12 dyn/cm(2)) relative to static. These differences correlated with a 60% increase in IRF-1 expression under low shear stress and a 40% decrease under high shear stress. The addition of TGRL along with cytokine activated a fourfold increase in VCAM-1 expression and a twofold increase in IRF-1 expression. The combined effect of shear stress and TGRL on the upregulation of membrane VCAM-1 was abolished by transfection of HAECs with IRF-1-specific small interfering RNA. In a healthy swine model, elevated levels of endothelial IRF-1 were also observed within atherosusceptible regions of the aorta by Western blot analysis and immunohistochemistry, implicating arterial hemodynamics in the regulation of IRF-1 expression. These data demonstrate direct roles for fluid shear stress and postprandial TGRL from human serum in the regulation of IRF-1 expression and downstream inflammatory responses in HAECs.
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Affiliation(s)
- J Sherrod DeVerse
- Department of Biomedical Engineering, University of California, Davis, CA
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138
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Lauric A, Hippelheuser J, Cohen AD, Kadasi LM, Malek AM. Wall shear stress association with rupture status in volume matched sidewall aneurysms. J Neurointerv Surg 2013; 6:466-73. [DOI: 10.1136/neurintsurg-2013-010871] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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139
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Kadasi LM, Dent WC, Malek AM. Colocalization of thin-walled dome regions with low hemodynamic wall shear stress in unruptured cerebral aneurysms. J Neurosurg 2013; 119:172-9. [DOI: 10.3171/2013.2.jns12968] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Object
Wall shear stress (WSS) plays a role in regulating endothelial function and has been suspected in cerebral aneurysm rupture. The aim of this study was to evaluate the spatial relationship between localized thinning of the aneurysm dome and estimated hemodynamic factors, hypothesizing that a low WSS would correlate with aneurysm wall degeneration.
Methods
Steady-state computational fluid dynamics analysis was performed on 16 aneurysms in 14 patients based on rotational angiographic volumes to derive maps of WSS, its spatial gradient (WSSG), and pressure. Local dome thickness was estimated categorically based on tissue translucency from high-resolution intraoperative microscopy findings. Each computational model was oriented to match the corresponding intraoperative view and numerically sampled in thin and normal adjacent dome regions, with controls at the neck and parent vessel. The pressure differential was computed as the difference between aneurysm dome points and the mean neck pressure. Pulsatile time-dependent confirmatory analysis was carried out in 7 patients.
Results
Matched-pair analysis revealed significantly lower levels of WSS (0.381 Pa vs 0.816 Pa; p < 0.0001) in thin-walled dome areas than in adjacent baseline thickness regions. Similarly, log WSSG and log WSS × WSSG were both lower in thin regions (both p < 0.0001); multivariate logistic regression analysis identified lower WSS and higher pressure differential as independent correlates of lower wall thickness with an area under the curve of 0.80. This relationship was observed in both steady-state and time-dependent pulsatile analyses.
Conclusions
Thin-walled regions of unruptured cerebral aneurysms colocalize with low WSS, suggesting a cellular mechanotransduction link between areas of flow stasis and aneurysm wall thinning.
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Affiliation(s)
- Laith M. Kadasi
- 1Cerebrovascular and Endovascular Division, Department of Neurosurgery, Tufts Medical Center; and
- 2Tufts University School of Medicine, Boston, Massachusetts
| | - Walter C. Dent
- 1Cerebrovascular and Endovascular Division, Department of Neurosurgery, Tufts Medical Center; and
| | - Adel M. Malek
- 1Cerebrovascular and Endovascular Division, Department of Neurosurgery, Tufts Medical Center; and
- 2Tufts University School of Medicine, Boston, Massachusetts
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140
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Ford MD, Piomelli U. Exploring high frequency temporal fluctuations in the terminal aneurysm of the basilar bifurcation. J Biomech Eng 2013; 134:091003. [PMID: 22938370 DOI: 10.1115/1.4007279] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Cerebral aneurysms are a common cause of death and disability. Of all the cardiovascular diseases, aneurysms are perhaps the most strongly linked with the local fluid mechanic environment. Aside from early in vivo clinical work that hinted at the possibility of high-frequency intra-aneurysmal velocity oscillations, flow in cerebral aneurysms is most often assumed to be laminar. This work investigates, through the use of numerical simulations, the potential for disturbed flow to exist in the terminal aneurysm of the basilar bifurcation. The nature of the disturbed flow is explored using a series of four idealized basilar tip models, and the results supported by four patient specific terminal basilar tip aneurysms. All four idealized models demonstrated instability in the inflow jet through high frequency fluctuations in the velocity and the pressure at approximately 120 Hz. The instability arises through a breakdown of the inflow jet, which begins to oscillate upon entering the aneurysm. The wall shear stress undergoes similar high-frequency oscillations in both magnitude and direction. The neck and dome regions of the aneurysm present 180 deg changes in the direction of the wall shear stress, due to the formation of small recirculation zones near the shear layer of the jet (at the frequency of the inflow jet oscillation) and the oscillation of the impingement zone on the dome of the aneurysm, respectively. Similar results were observed in the patient-specific models, which showed high frequency fluctuations at approximately 112 Hz in two of the four models and oscillations in the magnitude and direction of the wall shear stress. These results demonstrate that there is potential for disturbed laminar unsteady flow in the terminal aneurysm of the basilar bifurcation. The instabilities appear similar to the first instability mode of a free round jet.
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Affiliation(s)
- Matthew D Ford
- Department of Mechanical and Materials Engineering, Queen's University, Kingston, Ontario K7L 3N6, Canada.
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141
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Takai J, Santu A, Zheng H, Koh SD, Ohta M, Filimban LM, Lemaître V, Teraoka R, Jo H, Miura H. Laminar shear stress upregulates endothelial Ca²⁺-activated K⁺ channels KCa2.3 and KCa3.1 via a Ca²⁺/calmodulin-dependent protein kinase kinase/Akt/p300 cascade. Am J Physiol Heart Circ Physiol 2013; 305:H484-93. [PMID: 23792675 DOI: 10.1152/ajpheart.00642.2012] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
In endothelial cells (ECs), Ca²⁺-activated K⁺ channels KCa2.3 and KCa3.1 play a crucial role in the regulation of arterial tone via producing NO and endothelium-derived hyperpolarizing factors. Since a rise in intracellular Ca²⁺ levels and activation of p300 histone acetyltransferase are early EC responses to laminar shear stress (LS) for the transcriptional activation of genes, we examined the role of Ca²⁺/calmodulin-dependent kinase kinase (CaMKK), the most upstream element of a Ca²⁺/calmodulin-kinase cascade, and p300 in LS-dependent regulation of KCa2.3 and KCa3.1 in ECs. Exposure to LS (15 dyn/cm²) for 24 h markedly increased KCa2.3 and KCa3.1 mRNA expression in cultured human coronary artery ECs (3.2 ± 0.4 and 45 ± 10 fold increase, respectively; P < 0.05 vs. static condition; n = 8-30), whereas oscillatory shear (OS; ± 5 dyn/cm² × 1 Hz) moderately increased KCa3.1 but did not affect KCa2.3. Expression of KCa2.1 and KCa2.2 was suppressed under both LS and OS conditions, whereas KCa1.1 was slightly elevated in LS and unchanged in OS. Inhibition of CaMKK attenuated LS-induced increases in the expression and channel activity of KCa2.3 and KCa3.1, and in phosphorylation of Akt (Ser473) and p300 (Ser1834). Inhibition of Akt abolished the upregulation of these channels by diminishing p300 phosphorylation. Consistently, disruption of the interaction of p300 with transcription factors eliminated the induction of these channels. Thus a CaMKK/Akt/p300 cascade plays an important role in LS-dependent induction of KCa2.3 and KCa3.1 expression, thereby regulating EC function and adaptation to hemodynamic changes.
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Affiliation(s)
- Jun Takai
- Department of Physiology and Cell Biology, University of Nevada School of Medicine, Reno, Nevada
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142
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Quantifying the speed of fluctuations in systolic blood pressure. Hypertens Res 2013; 36:1039-44. [PMID: 23784510 DOI: 10.1038/hr.2013.62] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2013] [Revised: 03/21/2013] [Accepted: 04/14/2013] [Indexed: 11/08/2022]
Abstract
Increased blood pressure variability (BPV), even in the absence of hypertension, has been identified as an important independent cardiovascular risk factor (CVRF). However, the role of the speed of changes in systolic blood pressure (SBP; vSBP) on cardiovascular risk needs to be investigated. The objective of this study was to investigate whether subjects with a high cardiovascular risk profile have an increased degree and speed of changes in SBP compared with subjects with low or no risk. Resting beat-to-beat blood pressure (BP) was recorded for 5 min. Standard BPV measures in both time and frequency domains were conducted. The s.d. of SBP (s.d.-SBP) values was used to quantify the degree of BPV. vSBP was assessed by calculating the slopes of oscillatory fluctuations in SBP for different interbeat intervals (IBI). Subjects were allocated to one of four groups according to the number of CVRFs (0, 1, 2, ≥ 3 CVRF). Of 122 subjects, 19.7% had 0 CVRF, 27.0% had 1, 32.0% had 2 and 21.3% had ≥ 3 CVRFs. There was an increase in vSBP across the four risk groups. The vSBP in patients without CVRF was 3.12 (1.09), 1 CVRF 3.23 (1.07), 2 CVRF 4.16 (2.26) and ≥ 3 CVRF 4.22 (1.66; P = 0.015). The s.d.-SBP was not significantly different between the cardiovascular risk groups. The speed of fluctuations in SBP rather than the degree of BPV is pronounced in patients with elevated cardiovascular risk. Increased speed of BP fluctuations may thus be a contributing mechanism to cardiovascular morbidity.
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143
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Leoncini G, Viazzi F, Storace G, Deferrari G, Pontremoli R. Blood pressure variability and multiple organ damage in primary hypertension. J Hum Hypertens 2013; 27:663-70. [PMID: 23739158 DOI: 10.1038/jhh.2013.45] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2012] [Revised: 04/16/2013] [Accepted: 04/26/2013] [Indexed: 02/06/2023]
Abstract
Organ damage (OD) is an indicator of increased cardiovascular risk. Blood pressure variability (BPV) is related to greater incidence of events, regardless of the severity of hypertension. We investigated the relationship between ambulatory blood pressure monitoring (ABPM)-derived indices of BPV and the presence of multiple OD in primary hypertension (PH). One hundred and sixty-nine untreated patients with PH were evaluated. Systolic (SBP) and diastolic blood pressure (DBP) variability were assessed as the crude and weighted (w.) standard deviation (s.d.), and average real variability (ARV) of the mean value of 24-h, awake and asleep ABPM recordings. Left ventricular mass index, intima-media thickness, estimated-glomerular filtration rate and urinary albumin excretion were assessed as indices of cardiac, vascular and renal damage, respectively. Risk profile progressively increased starting from patients without OD to patients with only one sign of OD, and then to those with multiple OD. In addition to greater severity of the organ involvement, the only variables that were found to significantly differ between subjects with multiple and single OD were office SBP (160 ± 14 vs 154 ± 11 mm Hg, P=0.0423) and DBP (101 ± 7 vs 97 ± 8 mm Hg, P=0.0291), ambulatory arterial stiffness index (AASI) (0.60 ± 0.10 vs 0.50 ± 0.17, P=0.0158) and indices of BPV (24-h SBP s.d., 23 ± 5 vs 20 ± 6 mm Hg, P=0.0300; awake SBP s.d., 22 ± 6 vs 19 ± 6 mm Hg, P=0.0366; 24-h SBP w.s.d., 20 ± 5 vs 17 ± 5 mm Hg, P=0.0385; and 24-h SBP ARV, 18 ± 4 vs 15 ± 5 mm Hg, P=0.0420). All the above mentioned BPV parameters turned out to be determinants of multiple OD, regardless of several confounding variables, including BP levels. Therefore, in hypertensive patients increased SBP variability is associated with multiple signs of OD, regardless of BP values.
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Affiliation(s)
- G Leoncini
- Department of Internal Medicine, University of Genoa, IRCCS Azienda Ospedaliera Universitaria San Martino - IST, Genoa, Italy
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144
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Warrick JW, Young EWK, Schmuck EG, Saupe KW, Beebe DJ. High-content adhesion assay to address limited cell samples. Integr Biol (Camb) 2013; 5:720-7. [PMID: 23426645 PMCID: PMC3832292 DOI: 10.1039/c3ib20224k] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Cell adhesion is a broad topic in cell biology that involves physical interactions between cells and other cells or the surrounding extracellular matrix, and is implicated in major research areas including cancer, development, tissue engineering, and regenerative medicine. While current methods have contributed significantly to our understanding of cell adhesion, these methods are unsuitable for tackling many biological questions requiring intermediate numbers of cells (10(2)-10(5)), including small animal biopsies, clinical samples, and rare cell isolates. To overcome this fundamental limitation, we developed a new assay to quantify the adhesion of ~10(2)-10(3) cells at a time on engineered substrates, and examined the adhesion strength and population heterogeneity via distribution-based modeling. We validated the platform by testing adhesion strength of cancer cells from three different cancer types (breast, prostate, and multiple myeloma) on both IL-1β activated and non-activated endothelial monolayers, and observed significantly increased adhesion for each cancer cell type upon endothelial activation, while identifying and quantifying distinct subpopulations of cell-substrate interactions. We then applied the assay to characterize adhesion of primary bone marrow stromal cells to different cardiac fibroblast-derived matrix substrates to demonstrate the ability to study limited cell populations in the context of cardiac cell-based therapies. Overall, these results demonstrate the sensitivity and robustness of the assay as well as its ability to enable extraction of high content, functional data from limited and potentially rare primary samples. We anticipate this method will enable a new class of biological studies with potential impact in basic and translational research.
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Affiliation(s)
- Jay W. Warrick
- University of Wisconsin, Biomedical Engineering, Madison, WI. Fax: XX XXXX XXXX; Tel: XX XXXX XXXX
| | - Edmond W. K. Young
- University of Wisconsin, Biomedical Engineering, Madison, WI. Fax: XX XXXX XXXX; Tel: XX XXXX XXXX
| | - Eric G. Schmuck
- University of Wisconsin, School of Medicine and Public Health, Madison, WI
| | - Kurt W. Saupe
- University of Wisconsin, School of Medicine and Public Health, Madison, WI
| | - David J. Beebe
- University of Wisconsin, Biomedical Engineering, Madison, WI. Fax: XX XXXX XXXX; Tel: XX XXXX XXXX
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145
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Computational study of particle size effects on selective binding of nanoparticles in arterial stenosis. Comput Biol Med 2013; 43:417-24. [PMID: 23566388 DOI: 10.1016/j.compbiomed.2013.02.004] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2012] [Revised: 05/02/2012] [Accepted: 02/09/2013] [Indexed: 11/22/2022]
Abstract
In order to elucidate particle size and wall shear effects on the selective binding of nanoparticles to vessel wall, particle binding to the wall of arterial stenosis was computationally analyzed using a transport and reaction model. The attachment rate constant was modeled as a function of shear rate and particle size. The results showed that it had a positive correlation with the shear rate for particles smaller than 600 nm and a negative correlation with the shear rate for particles larger than 800 nm. Small size particles showed high binding selectivity in the stenosis region for the normal and shear-activated wall, whereas large particles showed high binding selectivity in the low and oscillatory zone for the shear-activated wall.
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146
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Bell JW, Chen D, Bahls M, Newcomer SC. Altered resting hemodynamics in lower-extremity arteries of individuals with spinal cord injury. J Spinal Cord Med 2013; 36:104-11. [PMID: 23809524 PMCID: PMC3595957 DOI: 10.1179/2045772312y.0000000052] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
OBJECTIVE To investigate lower-extremity arterial hemodynamics in individuals with spinal cord injury (SCI). We hypothesized that oscillatory shear index would be altered and resting mean shear would be higher in the lower-extremity arteries of SCI. RESEARCH Cross-sectional study of men and women with SCIs compared to able-bodied controls. SUBJECTS Subjects included 105 ages 18-72 years with American Spinal Injury Association (ASIA) Impairment Scale grades A, B, or C and injury duration at least 5 years. Subjects were matched for age and cardiovascular disease risk factors with 156 able-bodied controls. METHODS Diameter and blood velocity were determined with subject at rest via ultrasound in superficial femoral, popliteal, brachial, and carotid arteries. Mean shear, antegrade shear, retrograde shear, and oscillatory shear index were calculated. RESULTS Oscillatory shear index was lower in SCI compared to controls for superficial femoral (0.16 ± 0.10 vs. 0.26 ± 0.06, P < 0.01) and popliteal arteries (0.20 ± 0.11 vs. 0.26 ± 0.05, P < 0.01). Mean shear rate was higher in SCI compared to controls for superficial femoral (43.54 ± 28.0 vs. 20.48 ± 13.1/second, P < 0.01) and popliteal arteries (30.43 ± 28.1 vs. 11.68 ± 9.5/second, P < 0.01). CONCLUSIONS The altered resting hemodynamics in SCI are consistent with an atheroprotective hemodynamic environment.
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Affiliation(s)
- Jeffrey W. Bell
- Department of Health and Kinesiology, Purdue University, West Lafayette, IN, USA; and Department of Science, Southwest Minnesota State University, Marshall, MN, USA
| | - David Chen
- Rehabilitation Institute of Chicago, Spinal Cord Injury Rehabilitation Program, Chicago, IL, USA
| | - Martin Bahls
- Department of Health and Kinesiology, Purdue University, West Lafayette, IN, USA
| | - Sean C. Newcomer
- Department of Health and Kinesiology, Purdue University, West Lafayette, IN, USA,Correspondence to: Sean C. Newcomer, Department of Health and Kinesiology, Purdue University, Lambert Fieldhouse, 800 West Stadium Avenue, West Lafayette, IN 47907, USA. E-mail:
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147
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Luu NT, Glen KE, Egginton S, Rainger GE, Nash GB. Integrin-substrate interactions underlying shear-induced inhibition of the inflammatory response of endothelial cells. Thromb Haemost 2012; 109:298-308. [PMID: 23238518 DOI: 10.1160/th12-06-0400] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2012] [Accepted: 11/08/2012] [Indexed: 11/05/2022]
Abstract
Conditioning of endothelial cells by shear stress suppresses their response to inflammatory cytokines. We questioned whether signalling through different integrin-matrix interactions, previously associated with the pathogenic effects of disturbed flow, supported the anti-inflammatory action of steady shear. Primary human endothelial cells were cultured on different substrates and exposed to shear stress (2.0Pa) for varying periods before stimulation with tumour necrosis factor-α (TNF). Shear-conditioning inhibited cytokine-induced recruitment of flowing neutrophils. However, the effect was similar for culture on collagen, laminin or fibronectin, even when seeding was reduced to 2 hours, and shear to 3 hours before TNF treatment (to minimise deposition of endothelial matrix). Nevertheless, in short- or longer-term cultures, reduction in expression of β(1)-integrin (but not β(3)-integrin) using siRNA essentially ablated the effect of shear-conditioning on neutrophil recruitment. Studies of focal adhesion kinase (FAK) phosphorylation, siRNA against FAK and a FAK-inhibitor (PF573228) indicated that FAK activity was an essential component downstream of β(1)-integrin. In addition, MAP-kinase p38 was phosphorylated downstream of FAK and also required for functional modification. Mechanotransduction through β(1)-integrins, FAK and p38 is required for anti-inflammatory effects of steady shear stress. Separation of the pathways which underlie pathological versus protective responses of different patterns of flow is required to enable therapeutic modification or mimicry, respectively.
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Affiliation(s)
- N Thin Luu
- Prof. Gerard Nash, School of Clinical and Experimental Medicine, College of Medical and Dental Sciences, University of Birmingham, Birmingham B15 2TT, UK, Tel.: +44 121 414 3670, Fax: +44 121 414 6919, E-mail:
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148
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Johnson BD, Mather KJ, Newcomer SC, Mickleborough TD, Wallace JP. Vitamin C prevents the acute decline of flow-mediated dilation after altered shear rate patterns. Appl Physiol Nutr Metab 2012; 38:268-74. [PMID: 23537017 DOI: 10.1139/apnm-2012-0169] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Oscillatory and retrograde shear rate (SR) impairs endothelial function, potentially through shear-induced oxidative stress. We tested the hypothesis that acute vitamin C supplementation would prevent the attenuation of brachial artery flow-mediated dilation (FMD) after a period of augmented oscillatory and retrograde SR. Twelve healthy men (aged 26 ± 3 years) participated in two 30-min study visits in which one arm was subjected to increased oscillatory and retrograde SR, using 60 mm Hg of forearm cuff compression, and the contralateral arm served as the control. Subjects ingested capsules containing either placebo (sucrose) or vitamin C at 90 and 120 min (1000 mg total vitamin C) prior to cuff compression periods in a randomized placebo-controlled double-blind crossover study. Oscillatory and retrograde SR in the cuffed arms increased during the compression periods in the placebo and vitamin C study visits (p < 0.01 for both), with no difference between studies (p > 0.05). Antegrade SR remained unchanged throughout the compression periods (p > 0.05), and mean SR was lower in the cuffed arm than in the control arm for both study visits (p < 0.05). FMD decreased after cuff compression in the placebo cuffed arm (precompression vs. postcompression, 5.2% ± 1.4% vs. 3.5% ± 1.4%; p < 0.05), but remained unchanged after vitamin C therapy in the cuffed arm (precompression vs. postcompression, 5.3% ± 2.4% vs. 5.7% ± 2.6%; p > 0.05). No FMD changes were observed in the control arm for either study visit (p > 0.05). These data demonstrate that acute vitamin C supplementation prevents the attenuation of FMD due to altered SR patterns, suggesting that oxidative stress contributes to the oscillatory and retrograde SR-induced impairment of FMD.
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Affiliation(s)
- Blair D Johnson
- a Department of Kinesiology, Indiana University, Bloomington, IN 47405, USA
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149
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Intercellular adhesion molecule-1 blockade attenuates inflammatory response and improves microvascular perfusion in rat pancreas grafts. Pancreas 2012; 41:1112-8. [PMID: 22617707 DOI: 10.1097/mpa.0b013e31824abb2c] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
OBJECTIVES After pancreas transplantation (PTx), early capillary malperfusion and leukocyte recruitment indicate the manifestation of severe ischemia/reperfusion injury (IRI). Oscillatory blood-flow redistribution (intermittent capillary perfusion, IP), leading to an overall decrease in erythrocyte flux, precedes complete microvascular perfusion failure with persistent blood flow cessation. We addressed the role of intercellular adhesion molecule-1 (ICAM-1) for leukocyte-endothelial interactions (LEIs) after PTx and evaluated the contribution of IP and malperfusion. METHODS Pancreas transplantation was performed in rats after 18-hour preservation, receiving either isotype-matched IgG or monoclonal anti-ICAM-1 antibodies (10 mg/kg intravenously) once before reperfusion. Leukocyte-endothelial interaction, IP, erythrocyte flux, and functional capillary density, respectively, were examined in vivo during 2-hour reperfusion. Nontransplanted animals served as controls. Tissue samples were analyzed by histomorphometry. RESULTS In grafts of IgG-treated animals, IP was encountered already at an early stage after reperfusion and steadily increased over 2 hours, whereas erythrocyte flux declined continuously. In contrast, inhibition of ICAM-1 significantly improved erythrocyte flux and delayed IP appearance by 2 hours. Further, anti-ICAM-1 significantly reduced LEI and leukocyte tissue infiltration when compared to IgG; edema development was less pronounced in response to anti-ICAM-1 monoclonal antibody. CONCLUSION Intercellular adhesion molecule-1 blockade significantly attenuates IRI via immediate reduction of LEI and concomitant improvement of capillary perfusion patterns, emphasizing its central role during IRI in PTx.
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150
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Yokota K, Fukuda M, Matsui Y, Hoshide S, Shimada K, Kario K. Impact of visit-to-visit variability of blood pressure on deterioration of renal function in patients with non-diabetic chronic kidney disease. Hypertens Res 2012; 36:151-7. [PMID: 23013884 DOI: 10.1038/hr.2012.145] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
An association between visit-to-visit variability (VVV) of blood pressure (BP) and renal damage was recently reported in a cross-sectional study. We aimed to clarify the longitudinal effect of VVV of BP on deterioration of renal function in patients with non-diabetic chronic kidney disease (CKD). We retrospectively studied 56 patients with non-diabetic CKD (stage 3 or 4) who visited our nephrology clinic between September 1994 and May 2011. VVV of BP was defined as the standard deviation and coefficient of variation (CV) of office BP measured at 12 consecutive visits. Main outcomes were the annual decline in the estimated glomerular filtration rate (eGFR) and the composite renal end point defined as a doubling of serum creatinine or the need for dialysis. The median observation period was 83 months. Standard deviation and CV of office systolic BP (SBP) were significantly associated with the slope of the eGFR after adjustments for confounders. The adjusted risk for composite renal end points more than doubled for each increment of 1-standard deviation of the standard deviation of office SBP (hazard ratio (HR) 2.20, P=0.001), and for each increment of 1-standard deviation of the CV of office SBP (HR 2.12, P=0.002). The present study demonstrated that the visit-to-visit variability of BP is an independent determinant of deterioration of renal function in patients with non-diabetic CKD.
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Affiliation(s)
- Kei Yokota
- Department of Medicine, Division of Cardiovascular Medicine, Jichi Medical University School of Medicine, Tochigi, Japan.
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