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Wang J, Xu J, Liu T, Yu C, Xu F, Wang G, Li S, Dai X. Biomechanics-mediated endocytosis in atherosclerosis. Front Cardiovasc Med 2024; 11:1337679. [PMID: 38638885 PMCID: PMC11024446 DOI: 10.3389/fcvm.2024.1337679] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2023] [Accepted: 03/04/2024] [Indexed: 04/20/2024] Open
Abstract
Biomechanical forces, including vascular shear stress, cyclic stretching, and extracellular matrix stiffness, which influence mechanosensitive channels in the plasma membrane, determine cell function in atherosclerosis. Being highly associated with the formation of atherosclerotic plaques, endocytosis is the key point in molecule and macromolecule trafficking, which plays an important role in lipid transportation. The process of endocytosis relies on the mobility and tension of the plasma membrane, which is sensitive to biomechanical forces. Several studies have advanced the signal transduction between endocytosis and biomechanics to elaborate the developmental role of atherosclerosis. Meanwhile, increased plaque growth also results in changes in the structure, composition and morphology of the coronary artery that contribute to the alteration of arterial biomechanics. These cross-links of biomechanics and endocytosis in atherosclerotic plaques play an important role in cell function, such as cell phenotype switching, foam cell formation, and lipoprotein transportation. We propose that biomechanical force activates the endocytosis of vascular cells and plays an important role in the development of atherosclerosis.
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Affiliation(s)
- Jinxuan Wang
- School of Basic Medical Sciences, Chengdu Medical College, Chengdu, China
- Department of Cardiology, The Third Affiliated Hospital of Chengdu Medical College, Chengdu, China
| | - Jianxiong Xu
- School of Health Management, Xihua University, Chengdu, China
| | - Tianhu Liu
- Department of Cardiology, The Third Affiliated Hospital of Chengdu Medical College, Chengdu, China
- Cardiology and Vascular Health Research Center, Chengdu Medical College, Chengdu, China
| | - Chaoping Yu
- Department of Cardiology, The Third Affiliated Hospital of Chengdu Medical College, Chengdu, China
- Cardiology and Vascular Health Research Center, Chengdu Medical College, Chengdu, China
| | - Fengcheng Xu
- Department of Cardiology, The Third Affiliated Hospital of Chengdu Medical College, Chengdu, China
- Cardiology and Vascular Health Research Center, Chengdu Medical College, Chengdu, China
| | - Guixue Wang
- Key Laboratory for Biorheological Science and Technology of Ministry of Education, State and Local Joint Engineering Laboratory for Vascular Implants, Bioengineering College of Chongqing University, Chongqing, China
| | - Shun Li
- School of Basic Medical Sciences, Chengdu Medical College, Chengdu, China
| | - Xiaozhen Dai
- Department of Cardiology, The Third Affiliated Hospital of Chengdu Medical College, Chengdu, China
- Cardiology and Vascular Health Research Center, Chengdu Medical College, Chengdu, China
- School of Biosciences and Technology, Chengdu Medical College, Chengdu, China
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Papanikolaou J, Ntalapascha M, Makris D, Koukoubani T, Tsolaki V, Zakynthinos G, Gourgoulianis K, Zakynthinos E. Diastolic dysfunction in men with severe obstructive sleep apnea syndrome but without cardiovascular or oxidative stress-related comorbidities. Ther Adv Respir Dis 2020; 13:1753466619880076. [PMID: 31566076 PMCID: PMC6769220 DOI: 10.1177/1753466619880076] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Background: We aimed to evaluate whether the severity of obstructive sleep apnea syndrome (OSAS) per se affects the prevalence of left ventricular (LV) diastolic dysfunction in patients without comorbidities. Methods: A total of 42 patients with first-diagnosed severe OSAS [apnea–hypopnea index (AHI) > 30] and 25 controls (AHI < 5), having been referred for snoring to the Sleep Laboratory Department of our tertiary Hospital, were enrolled in the study. Inclusion criteria were absence of any cardiovascular or oxidative stress-related comorbidities, and age between 20 and 70 years. Clinical, laboratory, echocardiographic, and polysomnographic data were recorded prospectively. Diastolic dysfunction diagnosis and grading was based on 2016 ASE/EACVI recommendations. Results: Severe OSAS was associated with significantly increased prevalence and degree of diastolic dysfunction (26/42; 61.9%) compared with controls (7/25; 28%) (p = 0.007). AHI ⩾ 55 (dichotomous value of severe OSAS subset) was also characterized by greater prevalence and degree of diastolic dysfunction compared with 30 < AHI < 55 patients (p = 0.015). In the severe OSAS subset, age >45 years-old, height <1.745 m, body-mass index (BMI) >27.76 kg m−2, OSAS severity (AHI > 57.35), oxidative stress (overnight reduction of reduced to oxidized glutathione ratio < 18.44%), and BMI/height ratio > 16.155 kg m−3 (an index describing ‘dense’, short-heavy patients) presented significant diagnostic utility in identifying diastolic dysfunction in ROC-curve analysis (0.697 ⩾ AUC ⩾ 0.855, 0.001 ⩽ p ⩽ 0.018). In binary logistic regression model, advanced age (OR 1.23, 95% CI 1.025–1.477; p = 0.026) and AHI (OR 1.123, 95% CI 1.007–1.253; p = 0.036) showed independent association with diastolic dysfunction in severe OSAS. Conclusions: The present prospective study may suggest that severe OSAS is significantly associated with LV diastolic dysfunction; OSAS clinical severity exerts a positive influence on (and possibly constitutes an independent risk factor of) LV diastolic dysfunction. The reviews of this paper are available via the supplementary material section.
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Affiliation(s)
- John Papanikolaou
- Department of Critical Care, University Hospital of Larissa, Biopolis, Larissa, 41110, Greece
| | | | - Demosthenes Makris
- Department of Critical Care, University Hospital of Larissa, Larissa, Thessaly, Greece
| | | | - Vasiliki Tsolaki
- Department of Critical Care, University Hospital of Larissa, Larissa, Thessaly, Greece
| | - George Zakynthinos
- Department of Critical Care, University Hospital of Larissa, Larissa, Thessaly, Greece
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Leipziger J, Praetorius H. Renal Autocrine and Paracrine Signaling: A Story of Self-protection. Physiol Rev 2020; 100:1229-1289. [PMID: 31999508 DOI: 10.1152/physrev.00014.2019] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Autocrine and paracrine signaling in the kidney adds an extra level of diversity and complexity to renal physiology. The extensive scientific production on the topic precludes easy understanding of the fundamental purpose of the vast number of molecules and systems that influence the renal function. This systematic review provides the broader pen strokes for a collected image of renal paracrine signaling. First, we recapitulate the essence of each paracrine system one by one. Thereafter the single components are merged into an overarching physiological concept. The presented survey shows that despite the diversity in the web of paracrine factors, the collected effect on renal function may not be complicated after all. In essence, paracrine activation provides an intelligent system that perceives minor perturbations and reacts with a coordinated and integrated tissue response that relieves the work load from the renal epithelia and favors diuresis and natriuresis. We suggest that the overall function of paracrine signaling is reno-protection and argue that renal paracrine signaling and self-regulation are two sides of the same coin. Thus local paracrine signaling is an intrinsic function of the kidney, and the overall renal effect of changes in blood pressure, volume load, and systemic hormones will always be tinted by its paracrine status.
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Affiliation(s)
- Jens Leipziger
- Department of Biomedicine, Aarhus University, Aarhus, Denmark; and Aarhus Institute of Advanced Studies (AIAS), Aarhus University, Aarhus, Denmark
| | - Helle Praetorius
- Department of Biomedicine, Aarhus University, Aarhus, Denmark; and Aarhus Institute of Advanced Studies (AIAS), Aarhus University, Aarhus, Denmark
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4
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Saez F, Hong NJ, Cabral PD, Garvin JL. Stretch-Induced Increases in Intracellular Ca Stimulate Thick Ascending Limb O 2- Production and Are Enhanced in Dahl Salt-Sensitive Rats. Hypertension 2019; 75:431-438. [PMID: 31865796 DOI: 10.1161/hypertensionaha.119.13765] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Mechanical stretch raises intracellular Ca (Cai) in many cell types. Luminal flow-derived stretch stimulates O2- production by thick ascending limbs (THALs). Renal O2- is greater in Dahl salt-sensitive (SS) than salt-resistant (SR) rats. We hypothesized that mechanical stretch stimulates Ca influx via TRPV4 (transient receptor potential vanilloid type 4) which in turn raises Cai in THALs; these increases in Cai are necessary for stretch to augment O2- production; and stretch-stimulated, and therefore flow-induced, O2- production is enhanced in SS compared with SR THALs due to elevated Ca influx and increased Cai. Cai and O2- were measured in SS and SR THALs from rats on normal salt using Fura2-acetoxymethyl ester and dihydroethidium, respectively. Stretch raised Cai in SS by 270.4±48.9 nmol/L and by 123.6±27.0 nmol/L in SR THALs (P<0.02). Removing extracellular Ca eliminated the increases and differences in Cai between strains. Knocking down TRPV4 in SS THALs reduced stretch-induced Cai to SR levels (SS: 92.0±15.9 nmol/L; SR: 123.6±27.0 nmol/L). RN1734, a TRPV4 inhibitor, blunted stretch-elevated Cai by ≈75% and ≈66% in SS (P<0.03) and SR (P<0.04), respectively. Stretch augmented O2- production by 58.6±10.2 arbitrary fluorescent units/min in SS and by 24.4±2.6 arbitrary fluorescent units/min in SR THALs (P<0.05). Removal of extracellular Ca blunted stretch-induced increases in O2- and eliminated differences between strains. RN1734 reduced stretch-induced O2- by ≈70% in SS (P<0.005) and ≈60% in SR (P<0.01). Conclusions are as follows: (1) stretch activates TRPV4, which raises Cai in THALs; (2) the increase in Cai stimulates O2- production; and (3) stretch-induced O2- production is enhanced in SS THALs due to greater increases in Cai.
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Affiliation(s)
- Fara Saez
- From the Department of Physiology and Biophysics, Case Western Reserve University, Cleveland, OH
| | - Nancy J Hong
- From the Department of Physiology and Biophysics, Case Western Reserve University, Cleveland, OH
| | - Pablo D Cabral
- From the Department of Physiology and Biophysics, Case Western Reserve University, Cleveland, OH
| | - Jeffrey L Garvin
- From the Department of Physiology and Biophysics, Case Western Reserve University, Cleveland, OH
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Fang Y, Wu D, Birukov KG. Mechanosensing and Mechanoregulation of Endothelial Cell Functions. Compr Physiol 2019; 9:873-904. [PMID: 30873580 PMCID: PMC6697421 DOI: 10.1002/cphy.c180020] [Citation(s) in RCA: 108] [Impact Index Per Article: 21.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Vascular endothelial cells (ECs) form a semiselective barrier for macromolecules and cell elements regulated by dynamic interactions between cytoskeletal elements and cell adhesion complexes. ECs also participate in many other vital processes including innate immune reactions, vascular repair, secretion, and metabolism of bioactive molecules. Moreover, vascular ECs represent a unique cell type exposed to continuous, time-dependent mechanical forces: different patterns of shear stress imposed by blood flow in macrovasculature and by rolling blood cells in the microvasculature; circumferential cyclic stretch experienced by the arterial vascular bed caused by heart propulsions; mechanical stretch of lung microvascular endothelium at different magnitudes due to spontaneous respiration or mechanical ventilation in critically ill patients. Accumulating evidence suggests that vascular ECs contain mechanosensory complexes, which rapidly react to changes in mechanical loading, process the signal, and develop context-specific adaptive responses to rebalance the cell homeostatic state. The significance of the interactions between specific mechanical forces in the EC microenvironment together with circulating bioactive molecules in the progression and resolution of vascular pathologies including vascular injury, atherosclerosis, pulmonary edema, and acute respiratory distress syndrome has been only recently recognized. This review will summarize the current understanding of EC mechanosensory mechanisms, modulation of EC responses to humoral factors by surrounding mechanical forces (particularly the cyclic stretch), and discuss recent findings of magnitude-specific regulation of EC functions by transcriptional, posttranscriptional and epigenetic mechanisms using -omics approaches. We also discuss ongoing challenges and future opportunities in developing new therapies targeting dysregulated mechanosensing mechanisms to treat vascular diseases. © 2019 American Physiological Society. Compr Physiol 9:873-904, 2019.
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Affiliation(s)
- Yun Fang
- Department of Medicine, University of Chicago, Chicago, Illinois, USA,Correspondence to
| | - David Wu
- Department of Medicine, University of Chicago, Chicago, Illinois, USA
| | - Konstantin G. Birukov
- Department of Anesthesiology, University of Maryland Baltimore School of Medicine, Baltimore, Maryland, USA
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Mui RK, Fernandes RN, Garver HG, Van Rooijen N, Galligan JJ. Macrophage-dependent impairment of α 2-adrenergic autoreceptor inhibition of Ca 2+ channels in sympathetic neurons from DOCA-salt but not high-fat diet-induced hypertensive rats. Am J Physiol Heart Circ Physiol 2018; 314:H863-H877. [PMID: 29351460 DOI: 10.1152/ajpheart.00536.2017] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
DOCA-salt and obesity-related hypertension are associated with inflammation and sympathetic nervous system hyperactivity. Prejunctional α2-adrenergic receptors (α2ARs) provide negative feedback to norepinephrine release from sympathetic nerves through inhibition of N-type Ca2+ channels. Increased neuronal norepinephrine release in DOCA-salt and obesity-related hypertension occurs through impaired α2AR signaling; however, the mechanisms involved are unclear. Mesenteric arteries are resistance arteries that receive sympathetic innervation from the superior mesenteric and celiac ganglia (SMCG). We tested the hypothesis that macrophages impair α2AR-mediated inhibition of Ca2+ channels in SMCG neurons from DOCA-salt and high-fat diet (HFD)-induced hypertensive rats. Whole cell patch-clamp methods were used to record Ca2+ currents from SMCG neurons maintained in primary culture. We found that DOCA-salt, but not HFD-induced, hypertension caused macrophage accumulation in mesenteric arteries, increased SMCG mRNA levels of monocyte chemoattractant protein-1 and tumor necrosis factor-α, and impaired α2AR-mediated inhibition of Ca2+ currents in SMCG neurons. α2AR dysfunction did not involve changes in α2AR expression, desensitization, or downstream signaling factors. Oxidative stress impaired α2AR-mediated inhibition of Ca2+ currents in SMCG neurons and resulted in receptor internalization in human embryonic kidney-293T cells. Systemic clodronate-induced macrophage depletion preserved α2AR function and lowered blood pressure in DOCA-salt rats. HFD caused hypertension without obesity in Sprague-Dawley rats and hypertension with obesity in Dahl salt-sensitive rats. HFD-induced hypertension was not associated with inflammation in SMCG and mesenteric arteries or α2AR dysfunction in SMCG neurons. These results suggest that macrophage-mediated α2AR dysfunction in the mesenteric circulation may only be relevant to mineralocorticoid-salt excess. NEW & NOTEWORTHY Here, we identify a contribution of macrophages to hypertension development through impaired α2-adrenergic receptor (α2AR)-mediated inhibition of sympathetic nerve terminal Ca2+ channels in DOCA-salt hypertensive rats. Impaired α2AR function may involve oxidative stress-induced receptor internalization. α2AR dysfunction may be unique to mineralocorticoid-salt excess, as it does not occur in obesity-related hypertension.
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Affiliation(s)
- Ryan K Mui
- Department of Physiology, Michigan State University , East Lansing, Michigan
| | - Roxanne N Fernandes
- Department of Pharmacology and Toxicology, Michigan State University , East Lansing, Michigan
| | - Hannah G Garver
- Department of Pharmacology and Toxicology, Michigan State University , East Lansing, Michigan
| | - Nico Van Rooijen
- Department of Molecular Cell Biology, Vrije Universiteit Medical Center , Amsterdam , The Netherlands
| | - James J Galligan
- Department of Pharmacology and Toxicology, Michigan State University , East Lansing, Michigan.,Neuroscience Program, Michigan State University , East Lansing, Michigan
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Oxidized low-density lipoprotein contributes to atherogenesis via co-activation of macrophages and mast cells. PLoS One 2015; 10:e0123088. [PMID: 25811595 PMCID: PMC4374860 DOI: 10.1371/journal.pone.0123088] [Citation(s) in RCA: 59] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2013] [Accepted: 02/27/2015] [Indexed: 12/30/2022] Open
Abstract
Oxidized low-density lipoprotein (OxLDL) is a risk factor for atherosclerosis, due to its role in endothelial dysfunction and foam cell formation. Tissue-resident cells such as macrophages and mast cells release inflammatory mediators upon activation that in turn cause endothelial activation and monocyte adhesion. Two of these mediators are tumor necrosis factor (TNF)-α, produced by macrophages, and histamine, produced by mast cells. Static and microfluidic flow experiments were conducted to determine the number of adherent monocytes on vascular endothelium activated by supernatants of oxLDL-treated macrophages and mast cells or directly by oxLDL. The expression of adhesion molecules on activated endothelial cells and the concentration of TNF-α and histamine in the supernatants were measured by flow cytometry and enzyme-linked immunosorbent assay, respectively. A low dose of oxLDL (8 μg/ml), below the threshold for the clinical presentation of coronary artery disease, was sufficient to activate both macrophages and mast cells and synergistically increase monocyte-endothelium adhesion via released TNF-α and histamine. The direct exposure of endothelial cells to a much higher dose of oxLDL (80 μg/ml) had less effect on monocyte adhesion than the indirect activation via oxLDL-treated macrophages and mast cells. The results of this work indicate that the co-activation of macrophages and mast cells by oxLDL is an important mechanism for the endothelial dysfunction and atherogenesis. The observed synergistic effect suggests that both macrophages and mast cells play a significant role in early stages of atherosclerosis. Allergic patients with a lipid-rich diet may be at high risk for cardiovascular events due to high concentration of low-density lipoprotein and histamine in arterial vessel walls.
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9
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Oxidative stress in patients with obstructive sleep apnea syndrome. Sleep Breath 2012; 17:549-55. [PMID: 22610662 DOI: 10.1007/s11325-012-0718-y] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2011] [Revised: 04/06/2012] [Accepted: 04/27/2012] [Indexed: 01/24/2023]
Abstract
PURPOSE We aimed to investigate whether systemic oxidative stress is increased in patients with obstructive sleep apnea syndrome (OSAS). METHODS A total of 18 patients with severe OSAS and 13 controls were included in the study. Inclusion criteria for OSAS patients were: snoring and apnea-hypopnea index (AHI) of >30 in full polysomnography, no previous treatment for OSAS, non-smoking status, and a medical history of being free of comorbidities known to increase oxidative stress. Controls were recruited among subjects assessed for snoring in the Sleep Laboratory Department if they had AHI<5. At baseline, patients were evaluated by the Epworth Sleepiness Scale and underwent spirometry, echocardiography, and full polysomnographic study. Blood samples were collected for evaluation of oxidative stress biomarkers [protein carbonyls, reduced (GSH) and oxidized (GSSG) glutathione, 8-isoprostane, thiobarbituric acid-reactive substances (TBARS), catalase activity, Cu-Zn superoxide dysmutase (SOD), total antioxidant capacity (TAC)] before and on the morning following polysomnography. RESULTS The overnight (morning-night) change (%) of GSH/GSSG ratio and GSH was significantly different between OSAS and controls (p = 0.03 and p = 0.048, respectively). Plasma protein carbonyls, erythrocyte catalase activity, 8-isoprostane, SOD, TBARS, and TAC plasma values were not different between OSAS and controls (p > 0.05). No significant correlation was found between changes in the levels of biomarkers and AHI, arousal, or desaturation index. CONCLUSION The present prospective investigation in a population free of comorbidities or factors which may increase systemic oxidative stress provides evidence that obstructive sleep apnea per se might be associated with increased oxidative burden possibly via GSH/GSSG pathway.
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10
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Lipid peroxidation and paraoxonase activity in nocturnal cyclic and sustained intermittent hypoxia. Sleep Breath 2012; 17:365-71. [PMID: 22528954 DOI: 10.1007/s11325-012-0703-5] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2011] [Revised: 03/02/2012] [Accepted: 04/03/2012] [Indexed: 10/28/2022]
Abstract
PURPOSE Obstructive sleep apnea (OSA) and chronic obstructive pulmonary disease (COPD) have been known to be associated with atherosclerosis and hypoxia which was suggested to have an important role in this process by the way of increased oxidative stress. In the present study, we aimed to evaluate the effects of nocturnal hypoxia pattern (intermittent versus sustained) on serum lipid peroxidation and paraoxonase (PON) activity. METHODS Blood collections were performed in 44 OSA, 11 non-apneic, nocturnal desaturated COPD, and 14 simple snorer patients after full-night polysomnographic recordings. Nocturnal sleep and respiratory parameters, oxygen desaturation indexes, serum malondialdehyde (MDA) levels by measuring with the help of the formation of thiobarbituric acid reactive substances (TBARS), and PON activity were assessed in all subjects. RESULTS OSA and COPD patients showed nocturnal hypoxemia, with a minimum oxygen saturation (SaO(2)) in ranges of 53-92 % and 50-87 %, respectively. The mean levels of TBARS was 15.7 ± 3.6 nmol and 15.3 ± 3.4 nmol malondialdehyde (MDA)/ml in OSA and COPD patients, respectively, while the mean level of the control group was 4.1 ± 1.2 nmol MDA/ml. The mean PON activity was found to be 124.2 ± 35.5 U/l in OSA patients and 124.6 ± 28.4 U/l in COPD patients. The mean PON activity of the control group was 269.0 ± 135.8 U/l. The increase in TBARS levels and the decrease in PON1 levels were statistically significant in both OSA and COPD patients according to controls (p < 0.001 for TBARS as well as PON1). CONCLUSION The results of this study revealed that both OSA and non-apneic, nocturnal desaturated COPD patients showed increased levels of lipid peroxidation and decreased PON activity despite the differences in nocturnal hypoxia pattern.
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11
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Lu D, Kassab GS. Role of shear stress and stretch in vascular mechanobiology. J R Soc Interface 2011; 8:1379-85. [PMID: 21733876 DOI: 10.1098/rsif.2011.0177] [Citation(s) in RCA: 179] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Blood vessels are under constant mechanical loading from blood pressure and flow which cause internal stresses (endothelial shear stress and circumferential wall stress, respectively). The mechanical forces not only cause morphological changes of endothelium and blood vessel wall, but also trigger biochemical and biological events. There is considerable evidence that physiologic stresses and strains (stretch) exert vasoprotective roles via nitric oxide and provide a homeostatic oxidative balance. A perturbation of tissue stresses and strains can disturb biochemical homeostasis and lead to vascular remodelling and possible dysfunction (e.g. altered vasorelaxation, tone, stiffness, etc.). These distinct biological endpoints are caused by some common biochemical pathways. The focus of this brief review is to point out some possible commonalities in the molecular pathways in response to endothelial shear stress and circumferential wall stretch.
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Affiliation(s)
- Deshun Lu
- Department of Biomedical Engineering, Indiana University-Purdue University Indianapolis, Indianapolis, IN 46202, USA
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12
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Urata J, Ikeda S, Koga S, Nakata T, Yasunaga T, Sonoda K, Koide Y, Ashizawa N, Kohno S, Maemura K. Negatively charged low-density lipoprotein is associated with atherogenic risk in hypertensive patients. Heart Vessels 2011; 27:235-42. [PMID: 21491122 DOI: 10.1007/s00380-011-0139-z] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/05/2010] [Accepted: 03/18/2011] [Indexed: 02/02/2023]
Abstract
Negatively charged low-density lipoprotein (LDL), generated via multiple processes such as oxidation, acetylation, or glycosylation, plays a key role in the initiation and progression of atherosclerosis and related diseases. Anion-exchange high-performance liquid chromatography (AE-HPLC) can subfractionate LDL into LDL-1, LDL-2, and LDL-3 based on LDL particle charge, but the clinical significance of LDL subfractions has not yet been elucidated. The aim of this study was to determine the clinical significance of these fractions with particular regard to atherogenic risk in hypertensive patients. Ninety-eight patients with essential hypertension (age 67.0 ± 10.7 years; 54 males) were enrolled in the present study. The relationships between LDL subfractions and atherogenic risk factors, including lipid profiles, blood pressure and plasma 8-isoprostane as a marker of oxidative stress, were examined. LDL-1 levels were significantly and negatively correlated with body mass index (r = -0.384, p < 0.001), systolic blood pressure (r = -0.457, p < 0.001), non-high-density lipoprotein cholesterol levels (r = -0.457, p < 0.001) and 8-isoprostane levels (r = -0.415, p < 0.001). LDL-3, which is the most negatively charged fraction of total LDL, was significantly and positively correlated with these parameters (r = 0.267, 0.481, 0.357, and 0.337, respectively). LDL-1 levels were significantly lower (p < 0.001), and LDL-2 and LDL-3 levels were significantly higher (each p < 0.001) in patients with poorly controlled hypertension than in patients with well-controlled hypertension. In addition, an increase in the total number of traditional risk factors at time of study participation, but not previous diagnosis, was associated with a decrease in LDL-1 levels and increases in LDL-2 and LDL-3 levels. These data suggest that LDL subfractions are associated with multiple atherogenic risk factors and that treatment to modify these risk factors could result in changes in LDL subfraction levels. In conclusion, LDL subfractions isolated by AE-HPLC may represent a marker of atherogenic risk in patients with hypertension.
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Affiliation(s)
- Jungo Urata
- Department of Cardiovascular Medicine, Nagasaki University Graduate School of Biomedical Sciences, 1-7-1 Sakamoto, Nagasaki, 852-8501, Japan
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Abstract
Blood vessels respond to changes in mechanical load from circulating blood in the form of shear stress and mechanical strain as the result of heart propulsions by changes in intracellular signaling leading to changes in vascular tone, production of vasoactive molecules, and changes in vascular permeability, gene regulation, and vascular remodeling. In addition to hemodynamic forces, microvasculature in the lung is also exposed to stretch resulting from respiratory cycles during autonomous breathing or mechanical ventilation. Among various cell signaling pathways induced by mechanical forces and reported to date, a role of reactive oxygen species (ROS) produced by vascular cells receives increasing attention. ROS play an essential role in signal transduction and physiologic regulation of vascular function. However, in the settings of chronic hypertension, inflammation, or acute injury, ROS may trigger signaling events that further exacerbate smooth muscle hypercontractility and vascular remodeling associated with hypertension and endothelial barrier dysfunction associated with acute lung injury and pulmonary edema. These conditions are also characterized by altered patterns of mechanical stimulation experienced by vasculature. This review will discuss signaling pathways regulated by ROS and mechanical stretch in the pulmonary and systemic vasculature and will summarize functional interactions between cyclic stretch- and ROS-induced signaling in mechanochemical regulation of vascular structure and function.
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Affiliation(s)
- Konstantin G Birukov
- Section of Pulmonary and Critical Care, Department of Medicine, University of Chicago, Chicago, Illinois 60637, USA.
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14
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Chapman KE, Sinclair SE, Zhuang D, Hassid A, Desai LP, Waters CM. Cyclic mechanical strain increases reactive oxygen species production in pulmonary epithelial cells. Am J Physiol Lung Cell Mol Physiol 2005; 289:L834-41. [PMID: 15964900 DOI: 10.1152/ajplung.00069.2005] [Citation(s) in RCA: 141] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Overdistention of lung tissue during mechanical ventilation may be one of the factors that initiates ventilator-induced lung injury (VILI). We hypothesized that cyclic mechanical stretch (CMS) of the lung epithelium is involved in the early events of VILI through the production of reactive oxygen species (ROS). Cultures of an immortalized human airway epithelial cell line (16HBE), a human alveolar type II cell line (A549), and primary cultures of rat alveolar type II cells were cyclically stretched, and the production of superoxide (O2-) was measured by dihydroethidium fluorescence. CMS stimulated increased production of O2- after 2 h in each type of cell. 16HBE cells exhibited no significant stimulation of ROS before 2 h of CMS (20% strain, 30 cycles/min), and ROS production returned to control levels after 24 h. Oxidation of glutathione (GSH), a cellular antioxidant, increased with CMS as measured by a decrease in the ratio of the reduced GSH level to the oxidized GSH level. Strain levels of 10% did not increase O2- production in 16HBE cells, whereas 15, 20, and 30% significantly increased generation of O2-. Rotenone, a mitochondrial complex I inhibitor, partially abrogated the stretch-induced generation of O2- after 2 h CMS in 16HBE cells. NADPH oxidase activity was increased after 2 h of CMS, contributing to the production of O2-. Increased ROS production in lung epithelial cells in response to elevated stretch may contribute to the onset of VILI.
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Affiliation(s)
- Kenneth E Chapman
- Department of Biomedical Engineering, Northwestern University, Evanston, Illinois, USA
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Liu JQ, Sham JSK, Shimoda LA, Kuppusamy P, Sylvester JT. Hypoxic constriction and reactive oxygen species in porcine distal pulmonary arteries. Am J Physiol Lung Cell Mol Physiol 2003; 285:L322-33. [PMID: 12665465 DOI: 10.1152/ajplung.00337.2002] [Citation(s) in RCA: 91] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
To determine whether reactive oxygen species (ROS) play an essential role in hypoxic pulmonary vasoconstriction (HPV) and the cellular locus of ROS production and action during HPV, we measured internal diameter (ID) at constant transmural pressure, lucigenin-derived chemiluminescence (LDCL), and electron paramagnetic resonance (EPR) spin adduct spectra in small distal porcine pulmonary arteries, and dichlorofluorescein (DCF) fluorescence in myocytes isolated from these arteries. Hypoxia (4% O2) decreased ID, increased DCF fluorescence, tended to increase LDCL, and in some preparations produced EPR spectra consistent with hydroxyl and alkyl radicals. Superoxide dismutase (SOD, 150 U/ml) or SOD + catalase (CAT, 200 U/ml) did not alter ID during normoxia but reduced or abolished the constriction induced by hypoxia. SOD also blocked HPV in endothelium-denuded arteries after restoration of the response by exposure to 10-10 M endothelin-1. Confocal fluorescence microscopy demonstrated that labeled SOD and CAT entered pulmonary arterial myocytes. SOD, SOD + CAT, and CAT blocked the increase in DCF fluorescence induced by hypoxia, but SOD + CAT and CAT also caused a stable increase in fluorescence during normoxia, suggesting that CAT diminished efflux of DCF from cells or oxidized the dye directly. We conclude that HPV required increased concentrations of ROS produced by and acting on pulmonary arterial smooth muscle rather than endothelium.
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Affiliation(s)
- J Q Liu
- Division of Pulmonary and Critical Care Medicine, The Johns Hopkins Asthma and Allergy Center, Baltimore, MD 21224, USA
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Quiñones-Galvan A, Pucciarelli A, Fratta-Pasini A, Garbin U, Franzoni F, Galetta F, Natali A, Cominacini L, Ferrannini E. Effective blood pressure treatment improves LDL-cholesterol susceptibility to oxidation in patients with essential hypertension. J Intern Med 2001; 250:322-6. [PMID: 11576319 DOI: 10.1046/j.1365-2796.2001.00844.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVES LDL-cholesterol particles from hypertensive patients exhibit enhanced susceptibility to in vitro oxidation, an abnormality thought to increase cardiovascular risk. We tested whether blood pressure (BP) normalization can reverse this abnormality. DESIGN Double-blind, randomized pharmacological intervention trial. SETTING Clinical research centre. Subjects. A total of 29 nondiabetic, normolipidaemic patients with essential hypertension (BP= 151 +/- 3/99 +/- 1 mmHg) and 11 normotensive controls (BP=125 +/- 3/85 +/- 1 mmHg) matched for gender, age, obesity, glucose tolerance and lipid profile. Intervention. Anti-hypertensive treatment for 3 months with a calcium-antagonist in randomized combination with either an ACE inhibitor or a beta-blocker. MAIN OUTCOME MEASURES Lag phase of copper-induced LDL oxidation, cell-mediated (human umbilical vein endothelium) generation of malondialdehyde (MDA) by LDL and vitamin E content in LDL. RESULTS At baseline in hypertensives versus controls, lag phase was shorter (89 +/- 3 vs. 107 +/- 6 min, P < 0.04), MDA generation was higher (5.8 +/- 0.1 vs. 5.1 +/- 0.2 nmol L(-1), P=0.002), and vitamin E was reduced (6.40 +/- 0.05 vs. 6.67 +/- 0.11 microg mg(-1), P=0.03). At 3 months, BP was normalized (124 +/- 3/81 +/- 1, P < 0.0001 vs. baseline, P=ns versus controls), lag phase was prolonged (to 98 +/- 3 min, P=0.0005), MDA generation was reduced (5.6 +/- 0.1 nmol L-1, P = 0.001), and vitamin E was increased (6.53 +/- 0.05 microg mg(-1), P=0.003), with no significant differences between the randomized groups. CONCLUSIONS In nondiabetic, nonobese, normolipidaemic patients with essential hypertension, LDL susceptibility to copper- and cell-mediated oxidation is increased. BP normalization is associated with a significant improvement, but not a full reversal, of this abnormality.
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Affiliation(s)
- A Quiñones-Galvan
- CNR Institute of Clinical Physiology and Department of Internal Medicine, University of Pisa, Italy
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