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Pacia MZ, Mateuszuk L, Chlopicki S, Baranska M, Kaczor A. Biochemical changes of the endothelium in the murine model of NO-deficient hypertension. Analyst 2015; 140:2178-84. [DOI: 10.1039/c4an01870b] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
Alterations in the α-helix and β-sheet content and the lipid-to-protein ratio are the most striking features of hypertension development in the vascular endothelium.
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Affiliation(s)
- M. Z. Pacia
- Faculty of Chemistry
- Jagiellonian University
- 30-060 Krakow
- Poland
- Jagiellonian Centre for Experimental Therapeutics (JCET)
| | - L. Mateuszuk
- Jagiellonian Centre for Experimental Therapeutics (JCET)
- Jagiellonian University
- 30-348 Krakow
- Poland
| | - S. Chlopicki
- Jagiellonian Centre for Experimental Therapeutics (JCET)
- Jagiellonian University
- 30-348 Krakow
- Poland
- Department of Experimental Pharmacology
| | - M. Baranska
- Faculty of Chemistry
- Jagiellonian University
- 30-060 Krakow
- Poland
- Jagiellonian Centre for Experimental Therapeutics (JCET)
| | - A. Kaczor
- Faculty of Chemistry
- Jagiellonian University
- 30-060 Krakow
- Poland
- Jagiellonian Centre for Experimental Therapeutics (JCET)
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102
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Humphrey JD, Dufresne ER, Schwartz MA. Mechanotransduction and extracellular matrix homeostasis. Nat Rev Mol Cell Biol 2014; 15:802-12. [PMID: 25355505 PMCID: PMC4513363 DOI: 10.1038/nrm3896] [Citation(s) in RCA: 1333] [Impact Index Per Article: 133.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Soft connective tissues at steady state are dynamic; resident cells continually read environmental cues and respond to them to promote homeostasis, including maintenance of the mechanical properties of the extracellular matrix (ECM) that are fundamental to cellular and tissue health. The mechanosensing process involves assessment of the mechanics of the ECM by the cells through integrins and the actomyosin cytoskeleton, and is followed by a mechanoregulation process, which includes the deposition, rearrangement or removal of the ECM to maintain overall form and function. Progress towards understanding the molecular, cellular and tissue-level effects that promote mechanical homeostasis has helped to identify key questions for future research.
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Affiliation(s)
| | - Eric R Dufresne
- 1] Department of Mechanical Engineering, Yale University. [2] Department of Cell Biology, Yale University
| | - Martin A Schwartz
- 1] Department of Biomedical Engineering, Yale University. [2] Department of Cell Biology, Yale University. [3] Department of Medicine, Yale University, New Haven, Connecticut, 06520 USA
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103
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Zainalabidin S, Budin SB, Ramalingam A, Lim YC. Aortic remodelling in chronic nicotine-administered rat. THE KOREAN JOURNAL OF PHYSIOLOGY & PHARMACOLOGY : OFFICIAL JOURNAL OF THE KOREAN PHYSIOLOGICAL SOCIETY AND THE KOREAN SOCIETY OF PHARMACOLOGY 2014; 18:411-8. [PMID: 25352761 PMCID: PMC4211125 DOI: 10.4196/kjpp.2014.18.5.411] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/05/2014] [Revised: 08/05/2014] [Accepted: 08/13/2014] [Indexed: 01/22/2023]
Abstract
Vascular remodelling is an adaptive mechanism, which counteracts pressure changes in blood circulation. Nicotine content in cigarette increases the risk of hypertension. The exact relationship between nicotine and vascular remodelling still remain unknown. Current study was aimed to determine the effect of clinically relevant dosage of nicotine (equivalent to light smoker) on aortic reactivity, oxidative stress markers and histomorphological changes. Twelve age-matched male Sprague-Dawley rats were randomly divided into two groups, i.e.: normal saline as control or 0.6 mg/kg nicotine for 28 days (i.p., n=6 per group). On day-29, the rats were sacrificed and the thoracic aorta was dissected immediately for further studies. Mean arterial pressure (MAP) and pulse pressure (PP) of nicotine-treated vs. control were significantly increased (p<0.05). Nicotine-treated group showed significant (p<0.05) increase tunica media thickness, and decrease in lumen diameter, suggesting vascular remodelling which lead to prior hypertension state. The phenylephrine (PE)-induced contractile response in nicotine group was significantly higher than control group (ED50=1.44×10(5) M vs. 4.9×10(6) M) (p<0.05~0.001). However, nicotine-treated rat showed significantly lower endothelium-dependent relaxation response to acetylcholine (ACh) than in control group (ED50=6.17×10(7) M vs. 2.82×10(7) M) (p<0.05), indicating loss of primary vascular function. Malondialdehyde (MDA), a lipid peroxidation marker was significantly higher in nicotine group. Superoxide dismutase (SOD) enzymatic activity and glutathione (GSH) were all reduced in nicotine group (p<0.05) vs. control, suggesting nicotine induces oxidative imbalance. In short, chronic nicotine administration impaired aortic reactivity, probably via redox imbalance and vascular remodelling mechanism.
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Affiliation(s)
- Satirah Zainalabidin
- Programme of Biomedical Science, School of Diagnostic and Applied Health Sciences, Faculty of Health Sciences, Universiti Kebangsaan Malaysia, Kuala Lumpur 50300, Malaysia
| | - Siti Balkis Budin
- Programme of Biomedical Science, School of Diagnostic and Applied Health Sciences, Faculty of Health Sciences, Universiti Kebangsaan Malaysia, Kuala Lumpur 50300, Malaysia
| | - Anand Ramalingam
- Programme of Biomedical Science, School of Diagnostic and Applied Health Sciences, Faculty of Health Sciences, Universiti Kebangsaan Malaysia, Kuala Lumpur 50300, Malaysia
| | - Yi Cheng Lim
- Programme of Biomedical Science, School of Diagnostic and Applied Health Sciences, Faculty of Health Sciences, Universiti Kebangsaan Malaysia, Kuala Lumpur 50300, Malaysia
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104
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Xu J, Shi GP. Vascular wall extracellular matrix proteins and vascular diseases. Biochim Biophys Acta Mol Basis Dis 2014; 1842:2106-2119. [PMID: 25045854 DOI: 10.1016/j.bbadis.2014.07.008] [Citation(s) in RCA: 238] [Impact Index Per Article: 23.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2014] [Revised: 07/07/2014] [Accepted: 07/14/2014] [Indexed: 01/08/2023]
Abstract
Extracellular matrix proteins form the basic structure of blood vessels. Along with providing basic structural support to blood vessels, matrix proteins interact with different sets of vascular cells via cell surface integrin or non-integrin receptors. Such interactions induce vascular cell de novo synthesis of new matrix proteins during blood vessel development or remodeling. Under pathological conditions, vascular matrix proteins undergo proteolytic processing, yielding bioactive fragments to influence vascular wall matrix remodeling. Vascular cells also produce alternatively spliced variants that induce vascular cell production of different matrix proteins to interrupt matrix homeostasis, leading to increased blood vessel stiffness; vascular cell migration, proliferation, or death; or vascular wall leakage and rupture. Destruction of vascular matrix proteins leads to vascular cell or blood-borne leukocyte accumulation, proliferation, and neointima formation within the vascular wall; blood vessels prone to uncontrolled enlargement during blood flow diastole; tortuous vein development; and neovascularization from existing pathological tissue microvessels. Here we summarize discoveries related to blood vessel matrix proteins within the past decade from basic and clinical studies in humans and animals - from expression to cross-linking, assembly, and degradation under physiological and vascular pathological conditions, including atherosclerosis, aortic aneurysms, varicose veins, and hypertension.
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Affiliation(s)
- Junyan Xu
- Department of Medicine, Zhujiang Hospital, Southern Medical University, Guangzhou 510515, China
| | - Guo-Ping Shi
- Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA.
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105
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dos Santos PP, Rafacho BPM, Gonçalves ADF, Jaldin RG, do Nascimento TB, Silva MAB, Cau SBA, Roscani MG, Azevedo PS, Minicucci MF, Tostes RDC, Zornoff LAM, de Paiva SAR. Vitamin D induces increased systolic arterial pressure via vascular reactivity and mechanical properties. PLoS One 2014; 9:e98895. [PMID: 24921930 PMCID: PMC4055656 DOI: 10.1371/journal.pone.0098895] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2014] [Accepted: 05/08/2014] [Indexed: 11/18/2022] Open
Abstract
Background/Aims The aim of this study was to evaluate whether supplementation of high doses of cholecalciferol for two months in normotensive rats results in increased systolic arterial pressure and which are the mechanisms involved. Specifically, this study assesses the potential effect on cardiac output as well as the changes in aortic structure and functional properties. Methods Male Wistar rats were divided into three groups: 1) Control group (C, n = 20), with no supplementation of vitamin D, 2) VD3 (n = 19), supplemented with 3,000 IU vitamin D/kg of chow; 3) VD10 (n = 21), supplemented with 10,000 IU vitamin D/kg of chow. After two months, echocardiographic analyses, measurements of systolic arterial pressure (SAP), vascular reactivity, reactive oxygen species (ROS) generation, mechanical properties, histological analysis and metalloproteinase-2 and -9 activity were performed. Results SAP was higher in VD3 and VD10 than in C rats (p = 0.001). Echocardiographic variables were not different among groups. Responses to phenylephrine in endothelium-denuded aortas was higher in VD3 compared to the C group (p = 0.041). Vascular relaxation induced by acetylcholine (p = 0.023) and sodium nitroprusside (p = 0.005) was impaired in both supplemented groups compared to the C group and apocynin treatment reversed impaired vasodilation. Collagen volume fraction (<0.001) and MMP-2 activity (p = 0.025) was higher in VD10 group compared to the VD3 group. Elastin volume fraction was lower in VD10 than in C and yield point was lower in VD3 than in C. Conclusion Our findings support the view that vitamin D supplementation increases arterial pressure in normotensive rats and this is associated with structural and functional vascular changes, modulated by NADPH oxidase, nitric oxide, and extracellular matrix components.
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Affiliation(s)
- Priscila Portugal dos Santos
- Department of Internal Medicine, Botucatu Medical School, UNESP - Universidade Estadual Paulista, Botucatu, São Paulo, Brazil
| | - Bruna Paola Murino Rafacho
- Department of Internal Medicine, Botucatu Medical School, UNESP - Universidade Estadual Paulista, Botucatu, São Paulo, Brazil
| | - Andréa de Freitas Gonçalves
- Department of Internal Medicine, Botucatu Medical School, UNESP - Universidade Estadual Paulista, Botucatu, São Paulo, Brazil
| | - Rodrigo Gibin Jaldin
- Department of Surgery and Orthopaedics, Botucatu Medical School, UNESP - Universidade Estadual Paulista, Botucatu, São Paulo, Brazil
| | - Thiago Bruder do Nascimento
- Department of Pharmacology, School of Medicine at Ribeirao Preto - USP, University of São Paulo, São Paulo, Brazil
| | | | - Stêfany Bruno Assis Cau
- Department of Pharmacology, School of Medicine at Ribeirao Preto - USP, University of São Paulo, São Paulo, Brazil
| | - Meliza Goi Roscani
- Department of Internal Medicine, Botucatu Medical School, UNESP - Universidade Estadual Paulista, Botucatu, São Paulo, Brazil
| | - Paula Schimdt Azevedo
- Department of Internal Medicine, Botucatu Medical School, UNESP - Universidade Estadual Paulista, Botucatu, São Paulo, Brazil
| | - Marcos Ferreira Minicucci
- Department of Internal Medicine, Botucatu Medical School, UNESP - Universidade Estadual Paulista, Botucatu, São Paulo, Brazil
| | - Rita de Cássia Tostes
- Department of Pharmacology, School of Medicine at Ribeirao Preto - USP, University of São Paulo, São Paulo, Brazil
| | - Leonardo Antonio Memede Zornoff
- Department of Internal Medicine, Botucatu Medical School, UNESP - Universidade Estadual Paulista, Botucatu, São Paulo, Brazil
| | - Sergio Alberto Rupp de Paiva
- Department of Internal Medicine, Botucatu Medical School, UNESP - Universidade Estadual Paulista, Botucatu, São Paulo, Brazil
- * E-mail:
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106
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Ferreira ADS, Moura NGRD. Asserted and neglected issues linking evidence-based and Chinese medicines for cardiac rehabilitation. World J Cardiol 2014; 6:295-303. [PMID: 24944759 PMCID: PMC4062128 DOI: 10.4330/wjc.v6.i5.295] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/28/2013] [Revised: 03/28/2014] [Accepted: 04/29/2014] [Indexed: 02/06/2023] Open
Abstract
High blood pressure is among the most prevalent chronic disease in adults that impacts on the quality of life of patients, which are often subjected to physical rehabilitation. Chinese medicine intervention in patients with hypertension presents promising albeit inconclusive results, mostly due to methodological issues. This paper discusses asserted and neglected issues linking evidence-based and Chinese medicines as related to systemic arterial hypertension, as well as their impact on the physical rehabilitation of those patients. On the one hand, natural history of hypertension, pulse palpation, and herbal therapy are among the asserted issues because of the scientific evidence collected about them, either in favor or against its integration to the current medical practice. On the other hand, anatomical variations of vessels and comparative physiology are among the most commonly neglected issues because previous researches on integrative medicine ignored the possible effects of these issues as related to the study’s outcome. The asserted issues highlighted in this paper stimulate the increasing use of Chinese medicine for health care and the continuity of research on integrative medicine in the cardiovascular field for rehabilitation. The neglected issues poses additional challenges that must not be overlooked in future research on this topic so that the integration of both traditional and current knowledge may be of benefit to the population with cardiovascular disease.
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107
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Suki B. Assessing the Functional Mechanical Properties of Bioengineered Organs With Emphasis on the Lung. J Cell Physiol 2014; 229:1134-40. [DOI: 10.1002/jcp.24600] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2014] [Accepted: 03/03/2014] [Indexed: 01/16/2023]
Affiliation(s)
- Béla Suki
- Department of Biomedical Engineering; Boston University; Boston Massachusetts
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108
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Avogaro A, Rattazzi M, Fadini GP. Ectopic calcification in diabetic vascular disease. Expert Opin Ther Targets 2014; 18:595-609. [DOI: 10.1517/14728222.2014.894021] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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109
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Ghods R, Gharooni M, Amin G, Nazem E, Nikbakht Nasrabadi A. Hypertension from the perspective of Iranian traditional medicine. IRANIAN RED CRESCENT MEDICAL JOURNAL 2014; 16:e16449. [PMID: 24829789 PMCID: PMC4005451 DOI: 10.5812/ircmj.16449] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 11/28/2013] [Revised: 12/22/2013] [Accepted: 01/11/2014] [Indexed: 12/17/2022]
Abstract
Background: Nowadays, hypertension is considered as a global public health issue and in recent decades, it has shown a growing trend due to changes in lifestyle. Objectives: The purpose of this investigation was to compare symptoms of hypertension with known diseases in ancient medical texts and to find a disease that had the maximum overlap of symptoms with hypertension. Materials and Methods: In this qualitative study, reliable sources of traditional medicine such as The Canon of Medicine by Avicenna, The Complete Art of Medicine (Kitab Kamil as-Sina’aat-Tibbiyya) by Haly Abbas, Facilitating Treatment and a letter for Health preservation (Tahsil Al-Elaj and Resale Hafez Al-Sehha) by Mohammad Taghi Shirazi, and some reliable resources of conventional medicine such as Harrison’s principles of internal medicine and databases such as Pubmed, Scopus, SID, and Magiran were probed base on keywords to find a disease that had the most overlapping symptoms with hypertension. By taking notes from the relevant materials, the extracted texts were compared and analyzed. Results: Findings showed that hypertension has the most overlap with Imila (accumulation of normal or abnormal fluid in the body) symptoms in Iranian traditional medicine. Although this is not a quietly perfect overlap and there are other causes and reasons including dry dystemperament of vessel wall (atherosclerosis), hot dystemperament of heart or damages to other organs like liver, kidney and nervous system that could also lead to hypertension according to Iranian traditional medicine. Conclusions: Finding the equivalent disease to HTN based on Iranian traditional medicine, could suggest a better strategy for preventing, treating and reducing debilitating its complications in the future. In conclusion, we can approach to hypertension with recommendations for reducing Imtila when we are dealing with a kind of hypertension that corresponds to Imtila. Therefore, if patient is suffering from another type of hypertension like dry dystemperament of vessel wall, it surely requires another treatment approach for reducing vessel wall dryness.
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Affiliation(s)
- Roshanak Ghods
- College of Traditional Medicine, Tehran University of Medical Sciences, Tehran, IR Iran
- College of Traditional Medicine, Iran University of Medical Sciences, Tehran, IR Iran
- Corresponding Author: Roshanak Ghods, College of Traditional Medicine, Iran University of Medical Sciences, Tehran, IR Iran. Tel: +98-9123163494, E-mail:
| | | | - Gholamreza Amin
- College of Traditional Medicine, Tehran University of Medical Sciences, Tehran, IR Iran
- Department of Pharmacognosy, Faculty of Pharmacy, Tehran University of Medical Sciences, Tehran, IR Iran
| | - Esmaeil Nazem
- College of Traditional Medicine, Tehran University of Medical Sciences, Tehran, IR Iran
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110
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Mao S, Wang Y, Zhang M, Hinek A. Phytoestrogen, tanshinone IIA diminishes collagen deposition and stimulates new elastogenesis in cultures of human cardiac fibroblasts. Exp Cell Res 2014; 323:189-197. [PMID: 24525372 DOI: 10.1016/j.yexcr.2014.02.001] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2013] [Revised: 01/30/2014] [Accepted: 02/03/2014] [Indexed: 12/16/2022]
Abstract
It has been previously reported that oral or intra-peritoneal administration of tanshinone IIA can alleviate the ventricular hypertrophy and fibrosis that develops in rats after experimental cardiac infarction. Our present studies, performed on cultures of human cardiac fibroblasts, investigated the mechanism by which tanshinone IIA produces these beneficial effects. We found that treatment of cardiac fibroblasts with 0.1-10µM tanshinone IIA significantly inhibited their deposition of collagen I, while enhancing production of new elastic fibers. Moreover, both anti-collagenogenic and pro-elastogenic effects of tanshinone IIA occurred only after selective activation of the G protein-coupled estrogen receptor (GPER). This subsequently leads to initiation of the PKA/CREB phosphorylation pathway that inversely modulated transcription of collagen I and elastin genes. Interestingly, treatment of human cardiac fibroblasts with tanshinone IIA additionally up-regulated the production of the 67-kDa elastin binding protein, which facilitates tropoelastin secretion, and increased synthesis of lysyl oxidase, catalyzing cross-linkings of tropoelastin. Moreover, tanshinone IIA also caused up-regulation in the synthesis of collagenolytic MMP-1, but down-regulated levels of elastolytic MMP-2 and MMP-9. In summary, our data validate a novel mechanism in which tanshinone IIA, interacting with a non-classic estrogen receptor, maintains the proper balance between the net deposition of collagen and elastin, allowing for optimal durability and resiliency of the newly deposited matrix.
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Affiliation(s)
- Shuai Mao
- Physiology & Experimental Medicine Program, Heart Center, Hospital for Sick Children, 555 University Avenue, Ontario, Toronto, QJ;Canada M5G 1X8; Department of Laboratory Medicine and Pathobiology, University of Toronto, Ontario, Canada; Second Clinical Medical College, Guangzhou University of Traditional Chinese Medicine, Guangzhou, China; Guangdong Provincial Hospital of Traditional Chinese Medicine, Guangzhou, China
| | - Yanting Wang
- Physiology & Experimental Medicine Program, Heart Center, Hospital for Sick Children, 555 University Avenue, Ontario, Toronto, QJ;Canada M5G 1X8
| | - Minzhou Zhang
- Second Clinical Medical College, Guangzhou University of Traditional Chinese Medicine, Guangzhou, China; Guangdong Provincial Hospital of Traditional Chinese Medicine, Guangzhou, China
| | - Aleksander Hinek
- Physiology & Experimental Medicine Program, Heart Center, Hospital for Sick Children, 555 University Avenue, Ontario, Toronto, QJ;Canada M5G 1X8; Department of Laboratory Medicine and Pathobiology, University of Toronto, Ontario, Canada.
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111
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Lan TH, Huang XQ, Tan HM. Vascular fibrosis in atherosclerosis. Cardiovasc Pathol 2013; 22:401-7. [DOI: 10.1016/j.carpath.2013.01.003] [Citation(s) in RCA: 94] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/19/2012] [Revised: 12/10/2012] [Accepted: 01/08/2013] [Indexed: 01/10/2023] Open
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112
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Zeinali-Davarani S, Chow MJ, Turcotte R, Zhang Y. Characterization of biaxial mechanical behavior of porcine aorta under gradual elastin degradation. Ann Biomed Eng 2013; 41:1528-38. [PMID: 23297000 DOI: 10.1007/s10439-012-0733-y] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2012] [Accepted: 12/19/2012] [Indexed: 11/29/2022]
Abstract
Arteries are composed of multiple constituents that endow the wall with proper structure and function. Many vascular diseases are associated with prominent mechanical and biological alterations in the wall constituents. In this study, planar biaxial tensile test data of elastase-treated porcine aortic tissue (Chow et al. in Biomech Model Mechanobiol 2013) is re-examined to characterize the altered mechanical behavior at multiple stages of digestion through constitutive modeling. Exponential-based as well as recruitment-based strain energy functions are employed and the associated constitutive parameters for individual digestion stages are identified using nonlinear parameter estimation. It is shown that when the major portion of elastin is degraded from a cut-open artery in the load-free state, the embedded collagen fibers are recruited at lower stretch levels under biaxial loads, leading to a rapid stiffening behavior of the tissue. Multiphoton microscopy illustrates that the collagen waviness decreases significantly with the degradation time, resulting in a rapid recruitment when the tissue is loaded. It is concluded that even when residual stresses are released, there exists an intrinsic mechanical interaction between arterial elastin and collagen that determines the mechanics of arteries and carries important implications to vascular mechanobiology.
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113
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Kinnear C, Chang WY, Khattak S, Hinek A, Thompson T, de Carvalho Rodrigues D, Kennedy K, Mahmut N, Pasceri P, Stanford WL, Ellis J, Mital S. Modeling and rescue of the vascular phenotype of Williams-Beuren syndrome in patient induced pluripotent stem cells. Stem Cells Transl Med 2012; 2:2-15. [PMID: 23283491 DOI: 10.5966/sctm.2012-0054] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Elastin haploinsufficiency in Williams-Beuren syndrome (WBS) leads to increased vascular smooth muscle cell (SMC) proliferation and stenoses. Our objective was to generate a human induced pluripotent stem (hiPS) cell model for in vitro assessment of the WBS phenotype and to test the ability of candidate agents to rescue the phenotype. hiPS cells were reprogrammed from skin fibroblasts of a WBS patient with aortic and pulmonary stenosis and healthy control BJ fibroblasts using four-factor retrovirus reprogramming and were differentiated into SMCs. Differentiated SMCs were treated with synthetic elastin-binding protein ligand 2 (EBPL2) (20 μg/ml) or the antiproliferative drug rapamycin (100 nM) for 5 days. We generated four WBS induced pluripotent stem (iPS) cell lines that expressed pluripotency genes and differentiated into all three germ layers. Directed differentiation of BJ iPS cells yielded an 85%-92% pure SMC population that expressed differentiated SMC markers, were functionally contractile, and formed tube-like structures on three-dimensional gel assay. Unlike BJ iPS cells, WBS iPS cells generated immature SMCs that were highly proliferative, showed lower expression of differentiated SMC markers, reduced response to the vasoactive agonists, carbachol and endothelin-1, impaired vascular tube formation, and reduced calcium flux. EBPL2 partially rescued and rapamycin fully rescued the abnormal SMC phenotype by decreasing the smooth muscle proliferation rate and enhancing differentiation and tube formation. WBS iPS cell-derived SMCs demonstrate an immature proliferative phenotype with reduced functional and contractile properties, thereby recapitulating the human disease phenotype. The ability of rapamycin to rescue the phenotype provides an attractive therapeutic candidate for patients with WBS and vascular stenoses.
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Affiliation(s)
- Caroline Kinnear
- Department of Pediatrics, University of Toronto, Toronto, Ontario, Canada
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114
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Ng CY, Kamisah Y, Faizah O, Jaarin K. The role of repeatedly heated soybean oil in the development of hypertension in rats: association with vascular inflammation. Int J Exp Pathol 2012; 93:377-87. [PMID: 22974219 DOI: 10.1111/j.1365-2613.2012.00839.x] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Thermally oxidized oil generates reactive oxygen species that have been implicated in several pathological processes including hypertension. This study was to ascertain the role of inflammation in the blood pressure raising effect of heated soybean oil in rats. Male Sprague-Dawley rats were divided into four groups and were fed with the following diets, respectively, for 6 months: basal diet (control); fresh soybean oil (FSO); five-time-heated soybean oil (5HSO); or 10-time-heated soybean oil (10HSO). Blood pressure was measured at baseline and monthly using tail-cuff method. Plasma prostacyclin (PGI(2) ) and thromboxane A(2) (TXA(2) ) were measured prior to treatment and at the end of the study. After six months, the rats were sacrificed, and the aortic arches were dissected for morphometric and immunohistochemical analyses. Blood pressure was increased significantly in the 5HSO and 10HSO groups. The blood pressure was maintained throughout the study in rats fed FSO. The aortae in the 5HSO and 10HSO groups showed significantly increased aortic wall thickness, area and circumferential wall tension. 5HSO and 10HSO diets significantly increased plasma TXA(2) /PGI(2) ratio. Endothelial VCAM-1 and ICAM-1 were significantly increased in 5HSO, as well as LOX-1 in 10HSO groups. In conclusion, prolonged consumption of repeatedly heated soybean oil causes blood pressure elevation, which may be attributed to inflammation.
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Affiliation(s)
- Chun-Yi Ng
- Department of Pharmacology, Universiti Kebangsaan Malaysia, Kuala Lumpur, Malaysia
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115
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da Costa CA, de Oliveira PRB, de Bem GF, de Cavalho LCRM, Ognibene DT, da Silva AFE, dos Santos Valença S, Pires KMP, da Cunha Sousa PJ, de Moura RS, Resende AC. Euterpe oleracea Mart.-derived polyphenols prevent endothelial dysfunction and vascular structural changes in renovascular hypertensive rats: role of oxidative stress. Naunyn Schmiedebergs Arch Pharmacol 2012; 385:1199-209. [DOI: 10.1007/s00210-012-0798-z] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2012] [Accepted: 09/18/2012] [Indexed: 01/25/2023]
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117
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Humphrey JD. Possible mechanical roles of glycosaminoglycans in thoracic aortic dissection and associations with dysregulated transforming growth factor-β. J Vasc Res 2012; 50:1-10. [PMID: 23018968 DOI: 10.1159/000342436] [Citation(s) in RCA: 92] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2012] [Accepted: 07/25/2012] [Indexed: 01/22/2023] Open
Abstract
BACKGROUND Four distinguishing histopathological characteristics of thoracic aortic aneurysms and dissections (TAADs) are the fragmentation or degradation of elastic fibers, loss of smooth muscle, pooling of glycosaminoglycans, and remodeling of fibrillar collagens. Of these, pooling of glycosaminoglycans appears to be unique to these lesions. METHODS This review acknowledges the importance of dysregulated transforming growth factor-β (TGF-β) in TAADs and offers a complementary hypothesis that increased TGF-β could contribute to the accumulation of glycosaminoglycans in the media of the proximal thoracic aorta. Regardless, observed pools of glycosaminoglycans could decrease tensile strength, cause stress concentrations, and increase intralamellar swelling pressure, all of which could initiate local delaminations that could subsequently propagate as dissections and result in a false lumen or rupture. CONCLUSIONS There is a pressing need to investigate potential mechanical as well as biological consequences of accumulated glycosaminoglycans in TAADs and to elucidate responsible signaling pathways, with particular attention to synthetic cells of nonmesodermal lineage. Such research could provide insight into the mechanisms of dissection and the seemingly paradoxical role of the over-expression of a cytokine that is typically associated with fibrosis but is implicated in a degenerative disease of the aorta that can result in a catastrophic mechanical failure.
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Affiliation(s)
- J D Humphrey
- Department of Biomedical Engineering, Yale University, and Vascular Biology and Therapeutics Program, Yale School of Medicine, New Haven, CT 06520, USA.
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118
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Tare M, Parkington HC, Bubb KJ, Wlodek ME. Uteroplacental Insufficiency and Lactational Environment Separately Influence Arterial Stiffness and Vascular Function in Adult Male Rats. Hypertension 2012; 60:378-86. [DOI: 10.1161/hypertensionaha.112.190876] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- Marianne Tare
- From the Department of Physiology (M.T., H.C.P., K.J.B.), Monash University, Clayton, Victoria, Australia; Department of Physiology (M.E.W.), University of Melbourne, Melbourne, Victoria, Australia
| | - Helena C. Parkington
- From the Department of Physiology (M.T., H.C.P., K.J.B.), Monash University, Clayton, Victoria, Australia; Department of Physiology (M.E.W.), University of Melbourne, Melbourne, Victoria, Australia
| | - Kristen J. Bubb
- From the Department of Physiology (M.T., H.C.P., K.J.B.), Monash University, Clayton, Victoria, Australia; Department of Physiology (M.E.W.), University of Melbourne, Melbourne, Victoria, Australia
| | - Mary E. Wlodek
- From the Department of Physiology (M.T., H.C.P., K.J.B.), Monash University, Clayton, Victoria, Australia; Department of Physiology (M.E.W.), University of Melbourne, Melbourne, Victoria, Australia
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119
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Zou Y, Zhang Y. The biomechanical function of arterial elastin in solutes. J Biomech Eng 2012; 134:1475435. [PMID: 24763624 DOI: 10.1115/1.4006593] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2011] [Indexed: 11/08/2022]
Abstract
Elastin is essential to accommodate physiological deformation and provide elastic support for blood vessels. As a long-lived extracellular matrix protein, elastin can suffer from cumulative effects of exposure to chemical damage, which greatly compromises the mechanical function of elastin. The mechanical properties of elastin are closely related to its microstructure and the external chemical environments. The purpose of this study is to investigate the changes in the macroscopic elastic and viscoelastic properties of isolated porcine aortic elastin under the effects of nonenzymatic mediated in vitro elastin-lipid interactions and glycation. Sodium dodecyl sulfate (SDS) was used for elastin-lipid interaction, while glucose was used for glycation of elastin. Elastin samples were incubated in SDS (20 mM) or glucose (2 M) solutions and were allowed to equilibrate for 48 h at room temperature. Control experiments were performed in 1 × Phosphate buffered saline (PBS). Biaxial tensile and stress relaxation experiments were performed to study the mechanical behavior of elastin with solute effects. Experimental results reveal that both the elastic and viscoelastic behaviors of elastin change in different biochemical solvents environments. The tangent stiffness of SDS treated elastin decreases to 63.57 ± 4.7% of the control condition in circumference and to 58.43 ± 2.65% in the longitude. Glucose treated elastin exhibits an increase in stiffness to 145.06 ± 1.48% of the control condition in the longitude but remains similar mechanical response in the circumferential direction. During stress relaxation experiments with a holding period of half an hour, elastin treated with SDS or glucose shows more prominent stress relaxation than the untreated ones.
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120
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Involvement of inflammation and adverse vascular remodelling in the blood pressure raising effect of repeatedly heated palm oil in rats. Int J Vasc Med 2012; 2012:404025. [PMID: 22778962 PMCID: PMC3388444 DOI: 10.1155/2012/404025] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2012] [Accepted: 04/12/2012] [Indexed: 11/18/2022] Open
Abstract
Oil thermoxidation during deep frying generates harmful oxidative free radicals that induce inflammation and increase the risk of hypertension. This study aimed to investigate the effect of repeatedly heated palm oil on blood pressure, aortic morphometry, and vascular cell adhesion molecule-1 (VCAM-1) expression in rats. Male Sprague-Dawley rats were divided into five groups: control, fresh palm oil (FPO), one-time-heated palm oil (1HPO), five-time-heated palm oil (5HPO), or ten-time-heated palm oil (10HPO). Feeding duration was six months. Blood pressure was measured at baseline and monthly using tail-cuff method. After six months, the rats were sacrificed and the aortic arches were dissected for morphometric and immunohistochemical analyses. FPO group showed significantly lower blood pressure than all other groups. Blood pressure was increased significantly in 5HPO and 10HPO groups. The aortae of 5HPO and 10HPO groups showed significantly increased thickness and area of intima-media, circumferential wall tension, and VCAM-1 than other groups. Elastic lamellae were disorganised and fragmented in 5HPO- and 10HPO-treated rats. VCAM-1 expression showed a significant positive correlation with blood pressure. In conclusion, prolonged consumption of repeatedly heated palm oil causes blood pressure elevation, adverse remodelling, and increased VCAM-1, which suggests a possible involvement of inflammation.
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121
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Dokholyan NV. Physical microscopic model of proteins under force. J Phys Chem B 2012; 116:6806-9. [PMID: 22375559 DOI: 10.1021/jp212543m] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Nature has evolved proteins to counteract forces applied on living cells, and has designed proteins that can sense forces. One can appreciate Nature's ingenuity in evolving these proteins to be highly sensitive to force and to have a high dynamic force range at which they operate. To achieve this level of sensitivity, many of these proteins are composed of multiple domains and linking peptides connecting these domains, each of them having their own force response regimes. Here, using a simple model of a protein, we address the question of how each individual domain responds to force. We also ask how multidomain proteins respond to forces. We find that the end-to-end distance of individual domains under force scales linearly with force. In multidomain proteins, we find that the force response has a rich range: at low force, extension is predominantly governed by "weaker" linking peptides or domain intermediates, while at higher force, the extension is governed by unfolding of individual domains. Overall, the force extension curve comprises multiple sigmoidal transitions governed by unfolding of linking peptides and domains. Our study provides a basic framework for the understanding of protein response to force, and allows for interpretation experiments in which force is used to study the mechanical properties of multidomain proteins.
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Affiliation(s)
- Nikolay V Dokholyan
- Department of Biochemistry and Biophysics, University of North Carolina, School of Medicine, Chapel Hill, North Carolina 27599, USA.
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122
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Progressive structural and biomechanical changes in elastin degraded aorta. Biomech Model Mechanobiol 2012; 12:361-72. [PMID: 22623109 DOI: 10.1007/s10237-012-0404-9] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2011] [Accepted: 05/01/2012] [Indexed: 10/28/2022]
Abstract
Aortic aneurysm is an important clinical condition characterized by common structural changes such as the degradation of elastin, loss of smooth muscle cells, and increased deposition of fibrillary collagen. With the goal of investigating the relationship between the mechanical behavior and the structural/biochemical composition of an artery, this study used a simple chemical degradation model of aneurysm and investigated the progressive changes in mechanical properties. Porcine thoracic aortas were digested in a mild solution of purified elastase (5 U/mL) for 6, 12, 24, 48, and 96 h. Initial size measurements show that disruption of the elastin structure leads to increased artery dilation in the absence of periodic loading. The mechanical properties of the digested arteries, measured with a biaxial tensile testing device, progress through four distinct stages termed (1) initial-softening, (2) elastomer-like, (3) extensible-but-stiff, and (4) collagen-scaffold-like. While stages 1, 3, and 4 are expected as a result of elastin degradation, the S-shaped stress versus strain behavior of the aorta resulting from enzyme digestion has not been reported previously. Our results suggest that gradual changes in the structure of elastin in the artery can lead to a progression through different mechanical properties and thus reveal the potential existence of an important transition stage that could contribute to artery dilation during aneurysm formation.
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123
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Wilson JS, Baek S, Humphrey JD. Importance of initial aortic properties on the evolving regional anisotropy, stiffness and wall thickness of human abdominal aortic aneurysms. J R Soc Interface 2012; 9:2047-58. [PMID: 22491975 DOI: 10.1098/rsif.2012.0097] [Citation(s) in RCA: 85] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Complementary advances in medical imaging, vascular biology and biomechanics promise to enable computational modelling of abdominal aortic aneurysms to play increasingly important roles in clinical decision processes. Using a finite-element-based growth and remodelling model of evolving aneurysm geometry and material properties, we show that regional variations in material anisotropy, stiffness and wall thickness should be expected to arise naturally and thus should be included in analyses of aneurysmal enlargement or wall stress. In addition, by initiating the model from best-fit material parameters estimated for non-aneurysmal aortas from different subjects, we show that the initial state of the aorta may influence strongly the subsequent rate of enlargement, wall thickness, mechanical behaviour and thus stress in the lesion. We submit, therefore, that clinically reliable modelling of the enlargement and overall rupture-potential of aneurysms may require both a better understanding of the mechanobiological processes that govern the evolution of these lesions and new methods of determining the patient-specific state of the pre-aneurysmal aorta (or correlation to currently unaffected portions thereof) through knowledge of demographics, comorbidities, lifestyle, genetics and future non-invasive or minimally invasive tests.
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Affiliation(s)
- J S Wilson
- Department of Biomedical Engineering, Yale University, New Haven, CT 06520, USA
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124
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Humphrey JD, Holzapfel GA. Mechanics, mechanobiology, and modeling of human abdominal aorta and aneurysms. J Biomech 2012; 45:805-14. [PMID: 22189249 PMCID: PMC3294195 DOI: 10.1016/j.jbiomech.2011.11.021] [Citation(s) in RCA: 187] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/10/2011] [Indexed: 12/25/2022]
Abstract
Biomechanical factors play fundamental roles in the natural history of abdominal aortic aneurysms (AAAs) and their responses to treatment. Advances during the past two decades have increased our understanding of the mechanics and biology of the human abdominal aorta and AAAs, yet there remains a pressing need for considerable new data and resulting patient-specific computational models that can better describe the current status of a lesion and better predict the evolution of lesion geometry, composition, and material properties and thereby improve interventional planning. In this paper, we briefly review data on the structure and function of the human abdominal aorta and aneurysmal wall, past models of the mechanics, and recent growth and remodeling models. We conclude by identifying open problems that we hope will motivate studies to improve our computational modeling and thus general understanding of AAAs.
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Affiliation(s)
- J D Humphrey
- Department of Biomedical Engineering and Vascular Biology and Therapeutics Program, Malone Engineering Center, Yale University, New Haven, CT 06520-8260, USA.
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125
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Coogan JS, Humphrey JD, Figueroa CA. Computational simulations of hemodynamic changes within thoracic, coronary, and cerebral arteries following early wall remodeling in response to distal aortic coarctation. Biomech Model Mechanobiol 2012; 12:79-93. [PMID: 22415052 DOI: 10.1007/s10237-012-0383-x] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2011] [Accepted: 02/23/2012] [Indexed: 01/19/2023]
Abstract
Mounting evidence suggests that the pulsatile character of blood pressure and flow within large arteries plays a particularly important role as a mechano-biological stimulus for wall growth and remodeling. Nevertheless, understanding better the highly coupled interactions between evolving wall geometry, structure, and properties and the hemodynamics will require significantly more experimental data. Computational fluid-solid-growth models promise to aid in the design and interpretation of such experiments and to identify candidate mechanobiological mechanisms for the observed arterial adaptations. Motivated by recent aortic coarctation models in animals, we used a computational fluid-solid interaction model to study possible local and systemic effects on the hemodynamics within the thoracic aorta and coronary, carotid, and cerebral arteries due to a distal aortic coarctation and subsequent spatial variations in wall adaptation. In particular, we studied an initial stage of acute cardiac compensation (i.e., maintenance of cardiac output) followed by early arterial wall remodeling (i.e., spatially varying wall thickening and stiffening). Results suggested, for example, that while coarctation increased both the mean and pulse pressure in the proximal vessels, the locations nearest to the coarctation experienced the greatest changes in pulse pressure. In addition, after introducing a spatially varying wall adaptation, pressure, left ventricular work, and wave speed all increased. Finally, vessel wall strain similarly experienced spatial variations consistent with the degree of vascular wall adaptation.
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Affiliation(s)
- Jessica S Coogan
- Department of Bioengineering, Stanford University, Stanford, CA, USA
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126
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Aupperle H, Disatian S. Pathology, protein expression and signaling in myxomatous mitral valve degeneration: comparison of dogs and humans. J Vet Cardiol 2012; 14:59-71. [PMID: 22364722 DOI: 10.1016/j.jvc.2012.01.005] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2011] [Revised: 12/25/2011] [Accepted: 01/02/2012] [Indexed: 01/19/2023]
Abstract
Myxomatous degenerative mitral valve disease (MMVD) is a common heart disease in dogs. Although several morphological similarities occur between human and canine MMVD differences exist. However, in advanced stages the accumulation of proteoglycans is the main finding in both species. The extracellular matrix (ECM) in normal canine and human mitral valves is similar. In MMVD of both species proteoglycans is the major alteration, although specific changes in collagen distribution exists. The valvular expression pattern of matrix metalloproteinases (MMPs) and of their inhibitors (TIMPs) differs, in part, between dogs and humans. The MMPs and TIMPs expression patterns are similar in normal canine and human mitral valves, but they are quite different during degenerative progression. Valve endothelial cells (VEC) and interstitial cells (VIC) are phenotypically transformed in canine and human MMVD. Inflammation is an unlikely cause of valve degeneration in humans and dogs. There are several lines of evidence suggesting that transforming growth factor β1 (TGF β1) and serotonin signaling may mediate valve degeneration in humans and dogs. Although human and canine MMVD share structural similarities, there are some differences in ECM changes, enzyme expression and cell transformation, which may reflect a varied pathogenesis of these diseases.
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Affiliation(s)
- Heike Aupperle
- Institute of Veterinary-Pathology, University Leipzig, Germany.
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127
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Ceron CS, Rizzi E, Guimaraes DA, Martins-Oliveira A, Cau SB, Ramos J, Gerlach RF, Tanus-Santos JE. Time course involvement of matrix metalloproteinases in the vascular alterations of renovascular hypertension. Matrix Biol 2012; 31:261-70. [PMID: 22342460 DOI: 10.1016/j.matbio.2012.01.009] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2011] [Accepted: 01/26/2012] [Indexed: 11/19/2022]
Abstract
Increased vascular matrix metalloproteinases (MMPs) levels play a role in late phases of hypertensive vascular remodeling. However, no previous study has examined the time course of MMPs in the various phases of two-kidney, one-clip hypertension (2K1C). We examined structural vascular changes, collagen and elastin content, vascular oxidative stress, and MMPs levels/activities during the development of 2K1C hypertension. Plasma angiotensin converting enzyme (ACE) activity was measured to assess renin-angiotensin system activation. Sham or 2K1C hypertensive rats were studied after 2, 4, 6, and 10weeks of hypertension. Systolic blood pressure (SBP) was monitored weekly. Morphometry of structural changes in the aortic wall was studied in hematoxylin/eosin, orcein and picrosirius red sections. Aortic NADPH activity and superoxide production was evaluated. Aortic gelatinolytic activity was determined by in situ zymography, and MMP-2, MMP-14, and tissue inhibitor of MMPs (TIMP)-2 levels were determined by gelatin zymography, immunofluorescence and immunohistochemistry. 2K1C hypertension was associated with increased ACE activity, which decreased to normal after 10 weeks. We found increased aortic collagen and elastin content in the early phase of hypertension, which were associated with vascular hypertrophy, increased vascular MMP-2 and MMP-14 (but not TIMP-2) levels, and increased gelatinolytic activity, possibly as a result of increased vascular NADPH oxidase activity and oxidative stress. These results indicate that vascular remodeling of renovascular hypertension is an early process associated with early increases in MMPs activities, enhanced matrix deposition and oxidative stress. Using antioxidants or MMPs inhibitors in the early phase of hypertension may prevent the vascular alterations of hypertension.
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Affiliation(s)
- Carla S Ceron
- Department of Pharmacology, Faculty of Medicine of Ribeirao Preto, University of Sao Paulo, Ribeirao Preto, SP, 14049-900, Brazil
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128
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Ruseva B, Atanasova M, Georgieva M, Shumkov N, Laleva P. Effects of selenium on the vessel walls and anti-elastin antibodies in spontaneously hypertensive rats. Exp Biol Med (Maywood) 2012; 237:160-6. [PMID: 22312058 DOI: 10.1258/ebm.2011.011212] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Selenium (Se) is an exogenous antioxidant that performs its role via expression of selenoproteins. Pathological changes of the structure of the vessel wall, elastin turnover and collagen production may lead to increased stiffness of the vessels with decreased blood flow to the peripheries. The level of anti-elastin antibodies (AEABs) may give information for elastin metabolism. The aim of the study is to investigate the influence of Se intake on the vessel wall changes and production of AEABs in spontaneously hypertensive rats (SHR). Twenty-four male, 32-week-old SHR were used, divided into three groups, G1, G2 and G3. Before blood and morphological testing, G1 received a low-Se diet for eight weeks, G2 received a diet with adequate Se content and G3 received a diet with Se supplementation. The Se nutritional status was assessed by determination of glutathione peroxidase-1 (GPx-1) activity in whole blood, using the 'Ransel' kit. The rats from group G3 showed higher GPx-1 activity and lower level of AEABs than the other groups (P = 0.021), and the aortic wall histology showed slight degenerative changes compared with other rats. A low-Se diet caused severe changes to the aortic wall's ultrastructure, whereas Se supplementation slowed the changes down. The morphometry revealed a thicker abdominal aortic wall in rats of G1 compared with the other groups, and reduced thickness of the wall of the left coronary artery in G3 compared with the other groups (P < 0.05). Our results have shown that low Se intake leads to severe changes in the vessel walls in SHR, whereas selenium supplementation slows down the elastin degradation and degenerative changes of the vessel walls.
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Affiliation(s)
- Boryana Ruseva
- Department of Physiology, Medical University-Pleven, 1 Kliment Ohridski Street, Pleven, Bulgaria.
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129
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Insulin induces production of new elastin in cultures of human aortic smooth muscle cells. THE AMERICAN JOURNAL OF PATHOLOGY 2012; 180:715-26. [PMID: 22236491 DOI: 10.1016/j.ajpath.2011.10.022] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/2011] [Revised: 09/27/2011] [Accepted: 10/23/2011] [Indexed: 11/23/2022]
Abstract
Diabetes mellitus accelerates atherosclerotic progression, peripheral angiopathy development, and arterial hypertension, all of which are associated with elastic fiber disease. However, the potential mechanistic links between insulin deficiency and impaired elastogenesis in diabetes have not been explored. Results of the present study reveal that insulin administered in therapeutically relevant concentrations (0.5 to 10 nmol/L) selectively stimulates formation of new elastic fibers in cultures of human aortic smooth muscle cells. These concentrations of insulin neither up-regulate collagen type I and fibronectin deposition nor stimulate cellular proliferation. Further, the elastogenic effect of insulin occurs after insulin receptor activation, which triggers the PI3K downstream signaling pathway and activates elastin gene transcription. In addition, the promoter region of the human elastin gene contains the CAAATAA sequence, consistent with the FoxO-recognized element, and the genomic effects of insulin occur after removal of the FoxO1 transcriptional inhibitor from the FoxO-recognized element in the elastin gene promoter. In addition, insulin signaling facilitates the association of tropoelastin with its specific 67-kDa elastin-binding protein/spliced form of β-galactosidase chaperone, enhancing secretion. These results are crucial to understanding of the molecular and cellular mechanisms of diabetes-associated vascular disease, and, in particular, endorse use of insulin therapy for treatment of atherosclerotic lesions in patients with type 1 diabetes, in which induction of new elastic fibers would mechanically stabilize the developing plaques and prevent arterial occlusions.
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130
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Tomiyama H, Yamashina A. Arterial Stiffness in Prehypertension: A Possible Vicious Cycle. J Cardiovasc Transl Res 2012; 5:280-6. [DOI: 10.1007/s12265-011-9345-4] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/23/2011] [Accepted: 12/21/2011] [Indexed: 12/31/2022]
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131
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Karšaj I, Humphrey JD. A Multilayered Wall Model of Arterial Growth and Remodeling. MECHANICS OF MATERIALS : AN INTERNATIONAL JOURNAL 2012; 44:110-119. [PMID: 22180692 PMCID: PMC3237688 DOI: 10.1016/j.mechmat.2011.05.006] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Adaptations of large arteries to sustained alterations in hemodynamics that cause changes in both caliber and stiffness are increasingly recognized as important initiators or indicators of cardiovascular risk to high flow, low resistance organs such as the brain, heart, and kidney. There is, therefore, a pressing need to understand better the underlying causes of geometric and material adaptations by large arteries and the associated time courses. Although such information must ultimately come from well designed experiments, mathematical models will continue to play a vital role in the design of these experiments and their interpretation. In this paper, we present a new multilayered model of the time course of basilar artery growth and remodeling in response to sustained alterations in blood pressure and flow. We show, for example, that single- and multi-layered models consistently predict similar changes in caliber and wall thickness, but multilayered models provide additional insight into other important metrics such as the residual stress related opening angle and the axial prestress, both of which are fundamental to arterial homeostasis and responses to injury or insult.
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Affiliation(s)
- Igor Karšaj
- Faculty of Mechanical Engineering and Naval Architecture, University of Zagreb, I. Lučića 5, Croatia
| | - Jay D Humphrey
- Department of Biomedical Engineering, Yale University, New Haven, CT, USA
- Corresponding author: J.D. Humphrey, Ph.D., Department of Biomedical Engineering, Yale University, New Haven, CT 06520-8260, (P) +1-203-432-6428, (F) +1-203-432-0030,
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133
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Hlavačková L, Janegová A, Uličná O, Janega P, Cerná A, Babál P. Spice up the hypertension diet - curcumin and piperine prevent remodeling of aorta in experimental L-NAME induced hypertension. Nutr Metab (Lond) 2011; 8:72. [PMID: 22005253 PMCID: PMC3214182 DOI: 10.1186/1743-7075-8-72] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2011] [Accepted: 10/17/2011] [Indexed: 11/10/2022] Open
Abstract
Background Increase of blood pressure is accompanied by functional and morphological changes in the vascular wall. The presented study explored the effects of curcuma and black pepper compounds on increased blood pressure and remodeling of aorta in the rat model of experimental NO-deficient hypertension. Methods Wistar rats were administered for 6 weeks clear water or L-NAME (40 mg/kg/day) dissolved in water, piperine (20 mg/kg/day), curcumin (100 mg/kg/day) or their combination in corn oil by oral gavage. The systolic blood pressure was measured weekly. Histological slices of thoracic aorta were stained with hematoxylin and eosin, Mallory's phosphotungstic acid hematoxylin (PTAH), orcein, picrosirius red and van Gieson staining and with antibodies against smooth muscle cells actin. Microscopic pictures were digitally processed and morphometrically evaluated. Results The increase of blood pressure caused by L-NAME was partially prevented by piperine and curcumin, but the effect of their combination was less significant. Animals with hypertension had increased wall thickness and cross-sectional area of the aorta, accompanied by relative increase of PTAH positive myofibrils and decrease of elastin, collagen and actin content. Piperine was able to decrease the content of myofibrils and slightly increase actin, while curcumin also prevented elastin decrease. The combination of spices had similar effects on aortic morphology as curcumin itself. Conclusions Administration of piperine or curcumin, less their combination, is able to partially prevent the increase of blood pressure caused by chronic L-NAME administration. The spices modify the remodeling of the wall of the aorta induced by hypertension. Our results show that independent administration of curcumin is more effective in preventing negative changes in blood vessel morphology accompanying hypertensive disease.
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Affiliation(s)
- Livia Hlavačková
- Department of Pathology, Faculty of Medicine Comenius University, Sasinkova 4, 81372 Bratislava, Slovakia.
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Thompson JA, Gimbel SA, Richardson BS, Gagnon R, Regnault TRH. The Effect of Intermittent Umbilical Cord Occlusion on Elastin Composition in the Ovine Fetus. Reprod Sci 2011; 18:990-7. [DOI: 10.1177/1933719111401655] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Affiliation(s)
- Jennifer A. Thompson
- Department of Physiology, The University of Western Ontario, London, Ontario, Canada
| | - Sarah A. Gimbel
- Department of Obstetrics and Gynecology, The University of Western Ontario, London, Ontario, Canada
| | - Bryan S. Richardson
- Department of Physiology, The University of Western Ontario, London, Ontario, Canada
- Department of Obstetrics and Gynecology, The University of Western Ontario, London, Ontario, Canada
| | - Robert Gagnon
- Department of Obstetrics and Gynecology, McGill University, Montreal, Quebec, Canada
| | - Timothy R. H. Regnault
- Department of Physiology, The University of Western Ontario, London, Ontario, Canada
- Department of Obstetrics and Gynecology, The University of Western Ontario, London, Ontario, Canada
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135
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Eberth JF, Cardamone L, Humphrey JD. Evolving biaxial mechanical properties of mouse carotid arteries in hypertension. J Biomech 2011; 44:2532-7. [PMID: 21851943 PMCID: PMC3169381 DOI: 10.1016/j.jbiomech.2011.07.018] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2011] [Revised: 06/06/2011] [Accepted: 07/17/2011] [Indexed: 10/17/2022]
Abstract
Quantifying the time course of load-induced changes in arterial wall geometry, microstructure, and properties is fundamental to developing mathematical models of growth and remodeling. Arteries adapt to altered pressure and flow by modifying wall thickness, inner diameter, and axial length via marked cell and matrix turnover. To estimate particular biomaterial implications of such adaptations, we used a 4-fiber family constitutive relation to quantify passive biaxial mechanical behaviors of mouse carotid arteries 0 (control), 7-10, 10-14, or 35-56 days after an aortic arch banding surgery that increased pulse pressure and pulsatile flow in the right carotid artery. In vivo circumferential and axial stretches at mean arterial pressure were, for example, 11% and 26% lower, respectively, in hypertensive carotids 35-56 days after banding than in normotensive controls; this finding is consistent with observations that hypertension decreases distensibility. Interestingly, the strain energy W stored in the carotids at individual in vivo conditions was also less in hypertensive compared with normotensive carotids. For example, at 35-56 days after banding, W was 24%, 39%, and 47% of normal values at diastolic, mean, and systolic pressures, respectively. The energy stored during the cardiac cycle, W(sys)-W(dias), also tended to be less, but this reduction did not reach significance. When computed at normal in vivo values of biaxial stretch, however, W was well above normal for the hypertensive carotids. This net increase resulted from an overall increase in the collagen-related anisotropic contribution to W despite a decrease in the elastin-related isotropic contribution. The latter was consistent with observed decreases in the mass fraction of elastin.
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Affiliation(s)
- J F Eberth
- Department of Engineering Technology, University of Houston and The Methodist Hospital Research Institute, Houston, TX, USA.
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Hale SA, Weger L, Mandala M, Osol G. Reduced NO signaling during pregnancy attenuates outward uterine artery remodeling by altering MMP expression and collagen and elastin deposition. Am J Physiol Heart Circ Physiol 2011; 301:H1266-75. [PMID: 21856919 DOI: 10.1152/ajpheart.00519.2011] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Recent findings indicate that endothelial nitric oxide (NO) plays a key role in uterine artery outward circumferential remodeling during pregnancy. Although the underlying mechanisms are not known, they likely involve matrix metalloproteinases (MMPs). The goal of this study was to examine the linkage among NO inhibition, expansive remodeling, and MMP expression within the uterine vascular wall. Adult female rats were treated with N(G)-nitro-L-arginine methyl ester [L-NAME (LPLN)] beginning on day 10 of pregnancy and until death at day 20 and compared with age-matched controls [late pregnant (LP)]. Mean arterial pressure of LPLN rats was significantly higher than controls. LPLN fetal and placental weights were significantly reduced compared with controls. Main uterine arteries (mUA) were collected to determine dimensional properties (lumen area and wall thickness), collagen and elastin content, and levels of endothelial nitric oxide synthase (eNOS) and MMP expression. Circumferential remodeling was attenuated, as evidenced by significantly smaller lumen diameters. eNOS RNA and protein were significantly (>90%) decreased in the LPLN mUA compared with LP. Collagen and elastin contents were significantly increased in LPLN rats by ∼10 and 25%, respectively, compared with LP (P < 0.05). Both MMP-2 and tissue inhibitors of metalloproteinase-2 as assessed by immunofluorescence were lower in the endothelium (reduction of 60%) and adventitia (reduction of 50%) of LPLN compared with LP mUA. Membrane bound MMP-1 (MT1-MMP) as assessed by immunoblot was significantly decreased in LPLN. These data suggest a novel contribution of MMPs to gestational uterine vascular remodeling and substantiate the linkage between NO signaling and gestational remodeling of the uterine circulation via altered MMP, TIMP-2, and MT1-MMP expression and activity.
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Affiliation(s)
- Sarah A Hale
- Department of Obstetrics, Gynecology and Reproductive Sciences, University of Vermont, Burlington, Vermont 05405, USA.
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Jordão MT, Ladd FV, Coppi AA, Chopard RP, Michelini LC. Exercise Training Restores Hypertension-Induced Changes in the Elastic Tissue of the Thoracic Aorta. J Vasc Res 2011; 48:513-24. [DOI: 10.1159/000329590] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2010] [Accepted: 05/20/2011] [Indexed: 01/13/2023] Open
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138
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Souza-Smith FM, Katz PS, Trask AJ, Stewart JA, Lord KC, Varner KJ, Vassallo DV, Lucchesi PA. Mesenteric resistance arteries in type 2 diabetic db/db mice undergo outward remodeling. PLoS One 2011; 6:e23337. [PMID: 21829729 PMCID: PMC3150429 DOI: 10.1371/journal.pone.0023337] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2011] [Accepted: 07/14/2011] [Indexed: 11/19/2022] Open
Abstract
OBJECTIVE Resistance vessel remodeling is controlled by myriad of hemodynamic and neurohormonal factors. This study characterized structural and molecular remodeling in mesenteric resistance arteries (MRAs) in diabetic (db/db) and control (Db/db) mice. METHODS Structural properties were assessed in isolated MRAs from 12 and 16 wk-old db/db and Db/db mice by pressure myography. Matrix regulatory proteins were measured by Western blot analysis. Mean arterial pressure and superior mesenteric blood flow were measured in 12 wk-old mice by telemetry and a Doppler flow nanoprobe, respectively. RESULTS Blood pressure was similar between groups. Lumen diameter and medial cross-sectional area were significantly increased in 16 wk-old db/db MRA compared to control, indicating outward hypertrophic remodeling. Moreover, wall stress and cross-sectional compliance were significantly larger in diabetic arteries. These remodeling indices were associated with increased expression of matrix regulatory proteins matrix metalloproteinase (MMP)-9, MMP-12, tissue inhibitors of matrix metalloproteinase (TIMP)-1, TIMP-2, and plasminogen activator inhibitor-1 (PAI-1) in db/db arteries. Finally, superior mesenteric artery blood flow was increased by 46% in 12 wk-old db/db mice, a finding that preceded mesenteric resistance artery remodeling. CONCLUSIONS These data suggest that flow-induced hemodynamic changes may supersede the local neurohormonal and metabolic milieu to culminate in hypertrophic outward remodeling of type 2 DM mesenteric resistance arteries.
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Affiliation(s)
- Flavia M. Souza-Smith
- Department of Pharmacology and Experimental Therapeutics, Louisiana State University Health Sciences Center, New Orleans, Louisiana, United States of America
- Department of Physiological Sciences, Federal University of Espirito Santo, Vitoria, Espirito Santo, Brazil
| | - Paige S. Katz
- Department of Physiology, Louisiana State University Health Sciences Center, New Orleans, Louisiana, United States of America
- Center for Cardiovascular and Pulmonary Research and The Heart Center, The Research Institute at Nationwide Children's Hospital, Columbus, Ohio, United States of America
- Department of Pediatrics, The Ohio State University, Columbus, Ohio, United States of America
| | - Aaron J. Trask
- Center for Cardiovascular and Pulmonary Research and The Heart Center, The Research Institute at Nationwide Children's Hospital, Columbus, Ohio, United States of America
- Department of Pediatrics, The Ohio State University, Columbus, Ohio, United States of America
| | - James A. Stewart
- Center for Cardiovascular and Pulmonary Research and The Heart Center, The Research Institute at Nationwide Children's Hospital, Columbus, Ohio, United States of America
- Department of Pediatrics, The Ohio State University, Columbus, Ohio, United States of America
| | - Kevin C. Lord
- Feik School of Pharmacy, University of the Incarnate Word, San Antonio, Texas, United States of America
| | - Kurt J. Varner
- Department of Pharmacology and Experimental Therapeutics, Louisiana State University Health Sciences Center, New Orleans, Louisiana, United States of America
| | - Dalton V. Vassallo
- Department of Physiological Sciences, Federal University of Espirito Santo, Vitoria, Espirito Santo, Brazil
| | - Pamela A. Lucchesi
- Center for Cardiovascular and Pulmonary Research and The Heart Center, The Research Institute at Nationwide Children's Hospital, Columbus, Ohio, United States of America
- Department of Pediatrics, The Ohio State University, Columbus, Ohio, United States of America
- * E-mail:
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139
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Association of intronic single-nucleotide polymorphisms in the EMILIN1 gene with essential hypertension in a Chinese population. J Hum Hypertens 2011; 26:553-61. [PMID: 21753788 DOI: 10.1038/jhh.2011.68] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Studies in mice suggest that the elastin microfibril interfacer-1 gene (EMILIN1), the gene encoding elastin microfibril interfacer-1 protein, contributes to the pathogenesis of essential hypertension (EH) in humans. EMILIN1 in part maintains elastic fibres in vessel walls, and hence peripheral arterial compliance. In a case-control study, we assessed 942 non-obese non-diabetic Chinese, comprising 467 patients with EH and 475 normotensive control subjects (166 without, and 309 with, family history of hypertension in first-degree relatives (FHH)). Hypertension in first-degree relatives occurred in 88%, 65% and 0% of cases, all controls and controls without FHH, respectively. We scanned for single-nucleotide polymorphisms (SNPs) and genotyped them in the EMILIN1 gene using high-resolution melt-curve analysis. No exonic variants were detected. We assessed the association of SNPs and their haplotypes with EH. Three SNPs in introns 1 and 5 (rs2289360, rs2011616 and rs7424556) were in strong pair-wise linkage disequilibrium (r(2)>0.89). All three SNPs were significantly associated with hypertension. Genotypic frequencies at the three SNPs differed significantly between cases and only those controls without FHH. Healthy controls with FHH should be excluded to increase the odds of detecting association. All the G alleles of rs2289360 (odds ratio = 1.69, P = 0.010), rs2011616 (odds ratio = 1.52, P = 0.038) and rs7424556 (odds ratio = 1.59, P = 0.023) were high-risk alleles in the recessive genetic model. We observed significant overall haplotypic association with EH (empirical P = 0.0072); GGG is a risk haplotype (P = 0.043). The overall results support EMILIN1 as a candidate gene for human EH.
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140
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Localised micro-mechanical stiffening in the ageing aorta. Mech Ageing Dev 2011; 132:459-67. [PMID: 21777602 PMCID: PMC3192262 DOI: 10.1016/j.mad.2011.07.003] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2011] [Revised: 05/09/2011] [Accepted: 07/05/2011] [Indexed: 12/31/2022]
Abstract
Age-related loss of tissue elasticity is a common cause of human morbidity and arteriosclerosis (vascular stiffening) is associated with the development of both fatal strokes and heart failure. However, in the absence of appropriate micro-mechanical testing methodologies, multiple structural remodelling events have been proposed as the cause of arteriosclerosis. Therefore, using a model of ageing in female sheep aorta (young: <18 months, old: >8 years) we: (i) quantified age-related macro-mechanical stiffness, (ii) localised in situ micro-metre scale changes in acoustic wave speed (a measure of tissue stiffness) and (iii) characterised collagen and elastic fibre remodelling. With age, there was an increase in both macro-mechanical stiffness and mean microscopic wave speed (and hence stiffness; young wave speed: 1701 ± 1 m s−1, old wave speed: 1710 ± 1 m s−1, p < 0.001) which was localized to collagen fibril-rich regions located between large elastic lamellae. These micro-mechanical changes were associated with increases in both collagen and elastic fibre content (collagen tissue area, young: 31 ± 2%, old: 40 ± 4%, p < 0.05; elastic fibre tissue area, young: 55 ± 3%, old: 69 ± 4%, p < 0.001). Localised collagen fibrosis may therefore play a key role in mediating age-related arteriosclerosis. Furthermore, high frequency scanning acoustic microscopy is capable of co-localising micro-mechanical and micro-structural changes in ageing tissues.
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141
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Ferruzzi J, Collins MJ, Yeh AT, Humphrey JD. Mechanical assessment of elastin integrity in fibrillin-1-deficient carotid arteries: implications for Marfan syndrome. Cardiovasc Res 2011; 92:287-95. [DOI: 10.1093/cvr/cvr195] [Citation(s) in RCA: 103] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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142
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Hunter KS, Lammers SR, Shandas R. Pulmonary vascular stiffness: measurement, modeling, and implications in normal and hypertensive pulmonary circulations. Compr Physiol 2011; 1:1413-35. [PMID: 23733649 PMCID: PMC4113421 DOI: 10.1002/cphy.c100005] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
This article introduces the concept of pulmonary vascular stiffness, discusses its increasingly recognized importance as a diagnostic marker in the evaluation of pulmonary vascular disease, and describes methods to measure and model it clinically, experimentally, and computationally. It begins with a description of systems-level methods to evaluate pulmonary vascular compliance and recent clinical efforts in applying such techniques to better predict patient outcomes in pulmonary arterial hypertension. It then progresses from the systems-level to the local level, discusses proposed methods by which upstream pulmonary vessels increase in stiffness, introduces concepts around vascular mechanics, and concludes by describing recent work incorporating advanced numerical methods to more thoroughly evaluate changes in local mechanical properties of pulmonary arteries.
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Affiliation(s)
- Kendall S. Hunter
- Department of Bioengineering, University of Colorado at Denver Anschutz Medical Campus (UCD-AMC), Aurora, Colorado
- Division of Cardiology, Department of Pediatrics, The Children’s Hospital of Denver, UCD-AMC, Aurora, Colorado
| | - Steven R. Lammers
- Department of Bioengineering, University of Colorado at Denver Anschutz Medical Campus (UCD-AMC), Aurora, Colorado
- Cardiovascular Pulmonary (CVP) Research Laboratory, UCD-AMC, Aurora, Colorado
| | - Robin Shandas
- Department of Bioengineering, University of Colorado at Denver Anschutz Medical Campus (UCD-AMC), Aurora, Colorado
- Division of Cardiology, Department of Pediatrics, The Children’s Hospital of Denver, UCD-AMC, Aurora, Colorado
- Department of Surgery, UCD-AMC, Aurora, Colorado
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143
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Moore J, Thibeault S. Insights into the role of elastin in vocal fold health and disease. J Voice 2011; 26:269-75. [PMID: 21708449 DOI: 10.1016/j.jvoice.2011.05.003] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2011] [Accepted: 05/04/2011] [Indexed: 02/02/2023]
Abstract
Elastic fibers are large, complex, and surprisingly poorly understood extracellular matrix macromolecules. The elastin fiber, generated from a single human gene--elastin, is a self assembling integral protein that endows critical mechanical proprieties to elastic tissues and organs such as the skin, lungs, and arteries. The biology of elastic fibers is complex because they have multiple components, a tightly regulated developmental deposition, a multistep hierarchical assembly, and unique biomechanical functions. Elastin is present in vocal folds, where it plays a pivotal role in the quality of phonation. This review article provides an overview of the genesis of elastin and its wide-ranging structure and function. Specific distribution within the vocal fold lamina propria across the lifespan in normal and pathological states and its contribution to vocal fold biomechanics will be examined. Elastin and elastin-derived molecules are increasingly investigated for their application in tissue engineering. The properties of various elastin-based materials will be discussed and their current and future applications evaluated. A new level of understanding of the biomechanical properties of vocal fold elastin composites and their molecular basis should lead to new strategies for elastic fiber repair and regeneration in aging and disease.
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Affiliation(s)
- Jaime Moore
- Department of Surgery, Wisconsin Institutes for Medical Research, School of Medicine and Public Health, University of Wisconsin Madison, Madison, WI 53705-2275, USA
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144
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Shen C, Lu X, Wang L, Chen S, Li Y, Liu X, Li J, Huang J, Gu D. Novel genetic variation in exon 28 of FBN1 gene is associated with essential hypertension. Am J Hypertens 2011; 24:687-93. [PMID: 21331051 DOI: 10.1038/ajh.2011.21] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
BACKGROUND Recently, fibrillin-1 (FBN1) was reported to play an important role in maintaining the physiological arterial stiffness of essential hypertension (EH). Here, we designed a two-stage case-control study to investigate whether the FBN1 gene harbored any genetic variations associated with EH. METHODS In stage 1, six candidate single-nucleotide polymorphisms (SNPs) of the FBN1 gene were genotyped and tested in 503 cases and 490 controls. SNPs associated with EH (P < 0.05) in stage 1 would be genotyped in stage 2 (814 cases and 779 controls), and analyzed in all the individuals by allele, genotype, haplotype, and diplotype. A meta-analysis was performed and inverse-variance method with random effect model was employed to estimate combined odds ratio (OR) and its 95% confidence interval (CI) for the identified SNPs. RESULTS In stage 1, rs140598 and rs6493333 had statistical association with EH (P < 0.05) and enter stage 2. Multiple logistic regression analysis confirmed that rs140598 but not rs6493333 significantly associated with EH in stage 2 sample. Meta-analysis showed that there was nearly no heterogeneity (I(2) = 0) of genetic variance of rs140598 in the two stages, and the associations of rs140598 in all three genetic models presented statistical significance. Further haplotype analyses showed that the Hap2 (G-C) might decreased the risk of EH when compared with reference haplotype Hap1 (C-C), adjusted OR (95%CI) was 0.823 (0.715-0.948), P = 0.006. CONCLUSION Our finding suggested there is a significant association of rs140598 of FBN1 gene with EH and further replication in other population for association study or prospective study should be warranted.
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145
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Wagner HP, Humphrey JD. Differential Passive and Active Biaxial Mechanical Behaviors of Muscular and Elastic Arteries: Basilar Versus Common Carotid. J Biomech Eng 2011; 133:051009. [DOI: 10.1115/1.4003873] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Cerebrovascular disease continues to be responsible for significant morbidity and mortality. There is, therefore, a pressing need to understand better the biomechanics of both intracranial arteries and the extracranial arteries that feed these vessels. We used a validated four-fiber family constitutive relation to model passive biaxial stress-stretch behaviors of basilar and common carotid arteries and we developed a new relation to model their active biaxial responses. These data and constitutive relations allow the first full comparison of circumferential and axial biomechanical behaviors between a muscular (basilar) and an elastic (carotid) artery from the same species. Our active model describes the responses by both types of vessels to four doses of the vasoconstrictor endothelin-1 (10−10M, 10−9M, 10−8M, and 10−7M) and predicts levels of smooth muscle cell activation associated with basal tone under specific in vitro testing conditions. These results advance our understanding of the biomechanics of intracranial and extracranial arteries, which is needed to understand better their differential responses to similar perturbations in hemodynamic loading.
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Affiliation(s)
- H. P. Wagner
- Department of Biomedical Engineering, Texas A&M University, College Station, TX 77843
| | - J. D. Humphrey
- Fellow ASME
- Department of Biomedical Engineering, Yale University, New Haven, CT 06520; Vascular Biology and Therapeutics Program, Yale School of Medicine, New Haven, CT 06520
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146
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Xu H, Hu JJ, Humphrey JD, Liu JC. Automated measurement and statistical modelling of elastic laminae in arteries. Comput Methods Biomech Biomed Engin 2011; 13:749-63. [PMID: 20221934 DOI: 10.1080/10255840903580033] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Structural features of elastic laminae within arteries can provide vital information for both the mechanobiology and the biomechanics of the wall. In this paper, we propose, test and illustrate a new computer-based scheme for automated analysis of regional distributions of elastic laminae thickness, inter-lamellar distances and fragmentation furcation points (FPs) from standard histological images. Our scheme eliminates potential artefacts produced by tissue cutting, automatically aligns tissue according to physiologic orientations and performs cross-sectional measurements along radial directions. A statistical randomised complete block design and F test were used to assess the potential (non)-uniformity of lamellar thicknesses and separations along both radial and circumferential directions. Illustrative results for both normotensive and hypertensive thoracic porcine aorta revealed marked heterogeneity along the radial direction in nearly stress-free samples. Clearly, regional measurements can provide more detailed information about morphologic changes that cannot be gained by globally averaged evaluations alone. We also found that quantifying FP densities offers new information about potential elastin fragmentation, particularly in response to increased loading due to hypertension.
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Affiliation(s)
- Hai Xu
- Department of Computer Science, Texas A&M University, College Station, TX, USA
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147
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Castro MM, Tanus-Santos JE, Gerlach RF. Matrix metalloproteinases: targets for doxycycline to prevent the vascular alterations of hypertension. Pharmacol Res 2011; 64:567-72. [PMID: 21514386 DOI: 10.1016/j.phrs.2011.04.002] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Hypertension is associated with well known structural and functional alterations in both resistance and conduit arteries, which may be the result from long-lasting high blood pressure and may also be the cause of maintained hypertension and its complications. Therefore, in addition to lowering blood pressure, therapeutic strategies targeting the structural and functional modifications found in hypertensive patients may prevent the cardiovascular events and decrease the death rates associated with hypertension. Mounting evidence indicates that many vascular alterations associated with sustained hypertension are due to imbalanced matrix metalloproteinases (MMPs), a family of zinc-endopeptidases that degrade not only proteins of extracellular matrix (ECM) but several other substrates. Recent observations showed that abnormal MMP activity is a feature of the pathogenesis of hypertension and other diseases, thus justifying the development of drugs aiming at MMP downregulation. This review focuses on the extracellular actions of MMPs in hypertension-induced chronic vascular alterations. We then discuss the effects of MMP inhibitors, especially doxycycline, on the vascular changes associated with hypertension. There is now strong evidence that MMP inhibition with doxycycline (and maybe other MMP inhibitors) may attenuate the functional and structural alterations associated with hypertension, including increases in arterial stiffness. These beneficial effects may be, at least in part, independent of their antihypertensive effects.
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Affiliation(s)
- Michele M Castro
- Department of Pharmacology, Cardiovascular Research Centre, 4-62 Heritage Medical Research Centre, University of Alberta, Edmonton, Alberta, Canada T6G 2S2
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148
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Moreno MJ, Ajji A, Mohebbi-Kalhori D, Rukhlova M, Hadjizadeh A, Bureau MN. Development of a compliant and cytocompatible micro-fibrous polyethylene terephthalate vascular scaffold. J Biomed Mater Res B Appl Biomater 2011; 97:201-14. [PMID: 21391300 DOI: 10.1002/jbm.b.31774] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2009] [Revised: 08/19/2010] [Accepted: 09/25/2010] [Indexed: 01/09/2023]
Abstract
Bioengineering approaches have been intensively applied to create small diameter vascular grafts using artificial materials. However, a fully successful, high performing and anti-thrombogenic structure has not been achieved yet. In this study, we have designed and fabricated a novel non-woven fibrous vascular graft with biomechanical properties closely resembling those of native vessels. Vascular cell growth, preservation of cell phenotype, retention of vasoactive properties, as well as the effect of gelatin coating on the cellular interaction with the scaffolds under static and shear stress conditions were investigated. The non-woven fibrous scaffolds were made from melt blown polyethylene terephthalate fiber webs stacked by means of a consolidation technique. The scaffold variables were fiber diameter distribution and the number of consolidated web stacks. SEM analysis confirmed various fiber diameter and pore size ranges corresponding to the different conditions. The scaffolds showed burst pressure values of ∼1500 mmHg and compliance (8.4 ± 1.0 × 10(-2) % mmHg(-1) ) very similar to those of native arteries (∼8 × 10(-2) % mmHg(-1) ). The structure with the smallest fiber diameter range (1-5 μm) and pore size range (1-20 μm) was the most suitable for the growth of human brain endothelial cells and aortic smooth muscle cells. The cells maintained their specific cell phenotype, expressed collagen and elastin and produced cAMP in response to α-calcitonin gene-related peptide. However, under shear stress conditions (0.9 dyne cm(-2) ), only 30% of the cells were retained in both uncoated and gelatin-coated scaffolds indicating the need for improving the cell retention capacity of these structures, which is our future research direction. This study indicates that the biomechanical and biocompatible properties of this novel vascular scaffold are promising for the development of a vascular graft with similar characteristics to those of native vessels.
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Affiliation(s)
- M J Moreno
- Institute for Biological Sciences, National Research Council of Canada, M54, Ottawa, ON, K1A 0R6, Canada
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149
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A multi-layered computational model of coupled elastin degradation, vasoactive dysfunction, and collagenous stiffening in aortic aging. Ann Biomed Eng 2011; 39:2027-45. [PMID: 21380570 DOI: 10.1007/s10439-011-0287-4] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2010] [Accepted: 02/21/2011] [Indexed: 02/07/2023]
Abstract
Arterial responses to diverse pathologies and insults likely occur via similar mechanisms. For example, many studies suggest that the natural process of aging and isolated systolic hypertension share many characteristics in arteries, including loss of functional elastin, decreased smooth muscle tone, and altered rates of deposition, and/or crosslinking of fibrillar collagen. Our aim is to show computationally how these coupled effects can impact evolving aortic geometry and mechanical behavior. Employing a thick-walled, multi-layered constrained mixture model, we suggest that a coupled loss of elastin and vasoactive function are fundamental mechanisms by which aortic aging occurs. Moreover, it is suggested that collagenous stiffening, although itself generally an undesirable process, can play a key role in attenuating excessive dilatation, perhaps including the enlargement of abdominal aortic aneurysms.
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150
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Chabot N, Moreau S, Mulani A, Moreau P, Keillor JW. Fluorescent probes of tissue transglutaminase reveal its association with arterial stiffening. ACTA ACUST UNITED AC 2011; 17:1143-50. [PMID: 21035737 DOI: 10.1016/j.chembiol.2010.06.019] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2010] [Revised: 06/28/2010] [Accepted: 06/30/2010] [Indexed: 10/18/2022]
Abstract
Tissue transglutaminase (TG2) catalyzes the crosslinking of proteins. TG2 has been implicated in fibrosis and vascular calcification, both of which lead to a common feature of aging known as arterial stiffness. In order to probe the role of TG2 in arterial rigidification, we have prepared a fluorescent irreversible inhibitor as a probe for TG2 activity (RhodB-PGG-K(Acr)-LPF-OH). This probe was synthesized on solid support, characterized kinetically (k(inact) = 0.68 min⁻¹, K(I) = 79 μM), and then used to stain the aorta from rats used as a model of isolated systolic hypertension (ISH). Interestingly, TG2 activity was thus shown to increase over 4 weeks of the hypertension model, corresponding with the previously observed increase in arterial stiffness. These results clearly suggest an association between TG2 and the phenomenon of arterial rigidification.
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Affiliation(s)
- Nicolas Chabot
- Département de Chimie, Université de Montréal, C.P. 6128, Succursale Centre-ville, Montréal, QC H3C3J7, Canada
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