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Brückner A, Brandtner A, Rieck S, Matthey M, Geisen C, Fels B, Stei M, Kusche-Vihrog K, Fleischmann BK, Wenzel D. Site-specific genetic and functional signatures of aortic endothelial cells at aneurysm predilection sites in healthy and AngII ApoE -/- mice. Angiogenesis 2024:10.1007/s10456-024-09933-9. [PMID: 38965173 DOI: 10.1007/s10456-024-09933-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2023] [Accepted: 06/16/2024] [Indexed: 07/06/2024]
Abstract
Aortic aneurysm is characterized by a pathological dilation at specific predilection sites of the vessel and potentially results in life-threatening vascular rupture. Herein, we established a modified "Häutchen method" for the local isolation of endothelial cells (ECs) from mouse aorta to analyze their spatial heterogeneity and potential role in site-specific disease development. When we compared ECs from aneurysm predilection sites of healthy mice with adjacent control segments we found regulation of genes related to extracellular matrix remodeling, angiogenesis and inflammation, all pathways playing a critical role in aneurysm development. We also detected enhanced cortical stiffness of the endothelium at these sites. Gene expression of ECs from aneurysms of the AngII ApoE-/- model when compared to sham animals mimicked expression patterns from predilection sites of healthy animals. Thus, this work highlights a striking genetic and functional regional heterogeneity in aortic ECs of healthy mice, which defines the location of aortic aneurysm formation in disease.
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Affiliation(s)
- Alexander Brückner
- Life&Brain Center, Medical Faculty, Institute of Physiology I, University of Bonn, Bonn, Germany
| | - Adrian Brandtner
- Life&Brain Center, Medical Faculty, Institute of Physiology I, University of Bonn, Bonn, Germany
| | - Sarah Rieck
- Life&Brain Center, Medical Faculty, Institute of Physiology I, University of Bonn, Bonn, Germany
| | - Michaela Matthey
- Department of Systems Physiology, Medical Faculty, Institute of Physiology, Ruhr University of Bochum, Universitätsstr. 150, 44801, Bochum, Germany
| | - Caroline Geisen
- Life&Brain Center, Medical Faculty, Institute of Physiology I, University of Bonn, Bonn, Germany
| | - Benedikt Fels
- Institute of Physiology, University of Lübeck, Lübeck, Germany
- DZHK (German Research Centre for Cardiovascular Research), Partner SiteHamburg/Luebeck/Kiel, Luebeck, Germany
| | - Marta Stei
- Heart Center Bonn, Clinic for Internal Medicine II, University Hospital Bonn, Bonn, Germany
| | - Kristina Kusche-Vihrog
- Institute of Physiology, University of Lübeck, Lübeck, Germany
- DZHK (German Research Centre for Cardiovascular Research), Partner SiteHamburg/Luebeck/Kiel, Luebeck, Germany
| | - Bernd K Fleischmann
- Life&Brain Center, Medical Faculty, Institute of Physiology I, University of Bonn, Bonn, Germany
| | - Daniela Wenzel
- Life&Brain Center, Medical Faculty, Institute of Physiology I, University of Bonn, Bonn, Germany.
- Department of Systems Physiology, Medical Faculty, Institute of Physiology, Ruhr University of Bochum, Universitätsstr. 150, 44801, Bochum, Germany.
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MicroRNAs in Valvular Heart Diseases: Biological Regulators, Prognostic Markers and Therapeutical Targets. Int J Mol Sci 2021; 22:ijms222212132. [PMID: 34830016 PMCID: PMC8618095 DOI: 10.3390/ijms222212132] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2021] [Revised: 11/04/2021] [Accepted: 11/08/2021] [Indexed: 12/14/2022] Open
Abstract
miRNAs have recently attracted investigators’ interest as regulators of valvular diseases pathogenesis, diagnostic biomarkers, and therapeutical targets. Evidence from in-vivo and in-vitro studies demonstrated stimulatory or inhibitory roles in mitral valve prolapse development, aortic leaflet fusion, and calcification pathways, specifically osteoblastic differentiation and transcription factors modulation. Tissue expression assessment and comparison between physiological and pathological phenotypes of different disease entities, including mitral valve prolapse and mitral chordae tendineae rupture, emerged as the best strategies to address miRNAs over or under-representation and thus, their impact on pathogeneses. In this review, we discuss the fundamental intra- and intercellular signals regulated by miRNAs leading to defects in mitral and aortic valves, congenital heart diseases, and the possible therapeutic strategies targeting them. These miRNAs inhibitors are comprised of antisense oligonucleotides and sponge vectors. The miRNA mimics, miRNA expression vectors, and small molecules are instead possible practical strategies to increase specific miRNA activity. Advantages and technical limitations of these new drugs, including instability and complex pharmacokinetics, are also presented. Novel delivery strategies, such as nanoparticles and liposomes, are described to improve knowledge on future personalized treatment directions.
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Sabatino J, Wicik Z, De Rosa S, Eyileten C, Jakubik D, Spaccarotella C, Mongiardo A, Postula M, Indolfi C. MicroRNAs fingerprint of bicuspid aortic valve. J Mol Cell Cardiol 2019; 134:98-106. [DOI: 10.1016/j.yjmcc.2019.07.001] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/15/2019] [Revised: 06/17/2019] [Accepted: 07/01/2019] [Indexed: 02/07/2023]
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Chester AH, El-Hamamsy I, Butcher JT, Latif N, Bertazzo S, Yacoub MH. The living aortic valve: From molecules to function. Glob Cardiol Sci Pract 2014; 2014:52-77. [PMID: 25054122 PMCID: PMC4104380 DOI: 10.5339/gcsp.2014.11] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2014] [Accepted: 04/28/2014] [Indexed: 12/12/2022] Open
Abstract
The aortic valve lies in a unique hemodynamic environment, one characterized by a range of stresses (shear stress, bending forces, loading forces and strain) that vary in intensity and direction throughout the cardiac cycle. Yet, despite its changing environment, the aortic valve opens and closes over 100,000 times a day and, in the majority of human beings, will function normally over a lifespan of 70–90 years. Until relatively recently heart valves were considered passive structures that play no active role in the functioning of a valve, or in the maintenance of its integrity and durability. However, through clinical experience and basic research the aortic valve can now be characterized as a living, dynamic organ with the capacity to adapt to its complex mechanical and biomechanical environment through active and passive communication between its constituent parts. The clinical relevance of a living valve substitute in patients requiring aortic valve replacement has been confirmed. This highlights the importance of using tissue engineering to develop heart valve substitutes containing living cells which have the ability to assume the complex functioning of the native valve.
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Weiss RM, Miller JD, Heistad DD. Fibrocalcific aortic valve disease: opportunity to understand disease mechanisms using mouse models. Circ Res 2013; 113:209-22. [PMID: 23833295 DOI: 10.1161/circresaha.113.300153] [Citation(s) in RCA: 76] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Studies in vitro and in vivo continue to identify complex-regulated mechanisms leading to overt fibrocalcific aortic valve disease (FCAVD). Assessment of the functional impact of those processes requires careful studies of models of FCAVD in vivo. Although the genetic basis for FCAVD is unknown for most patients with FCAVD, several disease-associated genes have been identified in humans and mice. Some gene products which regulate valve development in utero also protect against fibrocalcific disease during postnatal aging. Valve calcification can occur via processes that resemble bone formation. But valve calcification can also occur by nonosteogenic mechanisms, such as formation of calcific apoptotic nodules. Anticalcific interventions might preferentially target either osteogenic or nonosteogenic calcification. Although FCAVD and atherosclerosis share several risk factors and mechanisms, there are fundamental differences between arteries and the aortic valve, with respect to disease mechanisms and responses to therapeutic interventions. Both innate and acquired immunity are likely to contribute to FCAVD. Angiogenesis is a feature of inflammation, but may also contribute independently to progression of FCAVD, possibly by actions of pericytes that are associated with new blood vessels. Several therapeutic interventions seem to be effective in attenuating the development of FCAVD in mice. Therapies which are effective early in the course of FCAVD, however, are not necessarily effective in established disease.
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Affiliation(s)
- Robert M Weiss
- Division of Cardiovascular Medicine, University of Iowa Carver College of Medicine, Iowa City, IA, USA.
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Mouse models and techniques for the isolation of the diabetic endothelium. ISRN ENDOCRINOLOGY 2013; 2013:165397. [PMID: 23840960 PMCID: PMC3693106 DOI: 10.1155/2013/165397] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/01/2013] [Accepted: 04/17/2013] [Indexed: 02/07/2023]
Abstract
Understanding the molecular mechanisms underlying diabetic endothelial dysfunction is necessary in order to improve the cardiovascular health of diabetic patients. Previously, we described an in vivo, murine model of insulin resistance induced by feeding a high-fat diet (HFD) whereby the endothelium may be isolated by fluorescence-activated cell sorting (FACS) based on Tie2-GFP expression and cell-surface staining. Here, we apply this model to two new strains of mice, ScN/Tie2-GFP and ApoE(−/−)/Tie2-GFP, and describe their metabolic responses and endothelial isolation. ScN/Tie2-GFP mice, which lack a functional toll-like receptor 4 (TLR4), display lower fasting glucose and insulin levels and improved glucose tolerance compared to Tie2-GFP mice, suggesting that TLR4 deficiency decreases susceptibility to the development of insulin resistance. ApoE(−/−)/Tie2-GFP mice display elevated glucose and cholesterol levels versus Tie2-GFP mice. Endothelial isolation by FACS achieves a pure population of endothelial cells that retain GFP fluorescence and endothelial functions. Transcriptional analysis of the aortic and muscle endothelium isolated from ApoE(−/−)/Tie2-GFP mice reveals a reduced endothelial response to HFD compared to Tie2-GFP mice, perhaps resulting from preexisting endothelial dysfunction in the hypercholesterolemic state. These mouse models and endothelial isolation techniques are valuable for assessing diabetic endothelial dysfunction and vascular responses in vivo.
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Arjunon S, Rathan S, Jo H, Yoganathan AP. Aortic valve: mechanical environment and mechanobiology. Ann Biomed Eng 2013; 41:1331-46. [PMID: 23515935 DOI: 10.1007/s10439-013-0785-7] [Citation(s) in RCA: 79] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2012] [Accepted: 03/02/2013] [Indexed: 01/11/2023]
Abstract
The aortic valve (AV) experiences a complex mechanical environment, which includes tension, flexure, pressure, and shear stress forces due to blood flow during each cardiac cycle. This mechanical environment regulates AV tissue structure by constantly renewing and remodeling the phenotype. In vitro, ex vivo and in vivo studies have shown that pathological states such as hypertension and congenital defect like bicuspid AV (BAV) can potentially alter the AV's mechanical environment, triggering a cascade of remodeling, inflammation, and calcification activities in AV tissue. Alteration in mechanical environment is first sensed by the endothelium, which in turn induces changes in the extracellular matrix, and triggers cell differentiation and activation. However, the molecular mechanism of this process is not understood very well. Understanding these mechanisms is critical for advancing the development of effective medical based therapies. Recently, there have been some interesting studies on characterizing the hemodynamics associated with AV, especially in pathologies like BAV, using different experimental and numerical methods. Here, we review the current knowledge of the local AV mechanical environment and its effect on valve biology, focusing on in vitro and ex vivo approaches.
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Affiliation(s)
- Sivakkumar Arjunon
- The Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Room 2119 U. A. Whitaker Building, 313 Ferst Drive, Atlanta, GA 30332-0535, USA
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Potential candidate genomic biomarkers of drug induced vascular injury in the rat. Toxicol Appl Pharmacol 2011; 257:284-300. [DOI: 10.1016/j.taap.2011.09.015] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2011] [Revised: 09/15/2011] [Accepted: 09/16/2011] [Indexed: 01/14/2023]
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9
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El-Hamamsy I, Chester AH, Yacoub MH. Cellular regulation of the structure and function of aortic valves. J Adv Res 2010. [DOI: 10.1016/j.jare.2010.02.007] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
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Dalmas DA, Scicchitano MS, Chen Y, Kane J, Mirabile R, Schwartz LW, Thomas HC, Boyce RW. Transcriptional Profiling of Laser Capture Microdissected Rat Arterial Elements: Fenoldopam-induced Vascular Toxicity as a Model System. Toxicol Pathol 2008; 36:496-519. [DOI: 10.1177/0192623307311400] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Transcriptional profiling of specific elements of vasculature from animal models of vascular toxicity is an approach to gain insight into molecular mechanisms of vascular injury. Feasibility of using laser capture microdissection (LCM) to evaluate differential gene expression in selected elements of mesenteric arteries (MA) from untreated rats and rats given a single vasotoxic dose of 100 mg/kg Fenoldopam and euthanized 1 or 4 hours postdose was assessed. Regions of MA (endothelial cells [EC] and vascular smooth muscle cells [VSMC]) were selectively microdissected from optimal-cutting-temperature (O.C.T.)-embedded-frozen tissue sections. RNA was isolated, linearly amplified (LA), and hybridized to Affymetrix GeneChips®. Enrichment for specific vascular elements was evident by unique gene-expression profiles. Statistical analysis indicated that Fenoldopam treatment resulted in differential expression of 333 versus 458 genes in EC and 371 versus 618 genes in VSMC at the 1-hour or 4-hour time point, respectively. Analysis of regulated EC and VSMC genes common to both time points identified several gene functions or pathways affected by treatment. Several genes were identified in EC and/or VSMC that have not been previously linked to vascular structure or function. These data indicate that tissue–element-enrichment by LCM in conjunction with LA and GeneChip analysis offers a refined approach for assessment of injury-mediated transcriptome changes in distinct elements of the vasculature.
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Affiliation(s)
| | | | - Yifeng Chen
- Discovery Technology Group, GlaxoSmithKline, King of Prussia, Pennsylvania, USA
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Lipoic acid significantly restores, in rats, the age-related decline in vasomotion. Br J Pharmacol 2008; 153:1615-22. [PMID: 18297110 DOI: 10.1038/bjp.2008.28] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
BACKGROUND AND PURPOSE The age-related decline in vasorelaxation is largely due to ceramide-induced induction of phosphatase 2A (PP2A), which limits nitric oxide synthase (eNOS) phosphorylation at stimulatory sites. We hypothesized that ceramide accumulation was from an age-related loss of endothelial glutathione (GSH) and subsequent activation of neutral sphingomyelinase (nSMase), an enzyme whose activity increases when GSH is limited. EXPERIMENTAL APPROACH Old (30-32 mo) F344xBN rats were given (R)-alpha-lipoic acid (LA), an agent known to induce GSH synthesis. Vasorelaxation was measured in aortic rings; GSH and ceramide levels, activity of nSMase and eNOS phosphorylation (by Western blot) was measured in aortic endothelial cells, isolated from the same aortas. KEY RESULTS In old animals, endothelium-dependent relaxation in aortic rings was decreased, GSH levels and its redox state in aortic endothelia were over 30% lower and nSMase activity and endothelial ceramide levels were three-fold increased, relative to young (2-4 mo) rats. LA treatment of old animals improved relaxation in aortic rings, reversed the changes in endothelial GSH, in nSMase activities and in ceramide levels. Similar effects on GSH levels and nSMase activity in old rats were also induced by treatment with GSH monoethylester. Activation (by phosphorylation) of eNOS was decreased by about 50% in old rats and this age-related decrease was partially reversed by LA treatment. CONCLUSIONS AND IMPLICATIONS Decreased endothelial GSH was partly responsible for the age-related loss of vascular endothelial function and LA might be therapeutically evaluated to treat endothelial dysfunction.
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Mohler ER, Fang Y, Shaffer RG, Moore J, Wilensky RL, Parmacek M, Levitan I. Hypercholesterolemia suppresses Kir channels in porcine bone marrow progenitor cells in vivo. Biochem Biophys Res Commun 2007; 358:317-24. [PMID: 17482574 PMCID: PMC2703014 DOI: 10.1016/j.bbrc.2007.04.138] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2007] [Accepted: 04/20/2007] [Indexed: 11/26/2022]
Abstract
OBJECTIVE Inwardly-rectifying K(+) (Kir) channels are responsible for maintaining membrane potentials in a variety of cell types including endothelial cells where they modulate endothelium-dependent vasorelaxation. The goal of this study is to determine the functional expression of Kir channels in porcine bone marrow-derived side population (BM-SP) cells that demonstrate phenotypes of endothelial progenitor cells (EPCs). We further asses the hypercholesterolemia sensitivity of Kir channels in BM-SP cells, which may play a key role in hypercholesterolemia-mediated regulation of EPCs. METHODS To assess the effect of hypercholesterolemia on Kir channels in BM-SP, Kir currents were recorded in SP cells sorted from the bone marrow of healthy or hypercholesterolemic animals. RESULTS We found Kir channels constitute the major conductance in porcine bone marrow-derived side population (BM-SP) cells. These cells are defined by their efficiency of Hoechst dye efflux and have been reported to differentiate into multiple cell lineages including endothelium in vivo. We demonstrate here that porcine BM-SP cells differentiate to an endothelial lineage (CD31(+), vWF(+)) supporting the hypothesis that these cells are endothelial progenitor cells. Also, BM-SP cells express Kir with biophysical properties recapitulating those in mature endothelial cells, but with a much higher current density. Flow cytometric (FACS) analysis indicated that the number of SP cells was unaffected by hypercholesterolemia. However, hypercholesterolemia significantly inhibited Kir channels in BM-SP cells. CONCLUSIONS We successfully demonstrate that BM side population cells represent an origin of endothelial progenitor cells. This study further shows, for the fist time, that the functional expression of Kir channels in bone marrow (BM)-derived SP. Moreover, we demonstrate that hypercholesterolemia condition significantly suppresses the Kir channels in BM-SP cells, suggesting that hypercholesterolemia-mediated regulation of Kir channels may be an important factor not only in dysfunction of mature endothelium but also in dysfunction of BM-SP cells.
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Affiliation(s)
- Emile R Mohler
- Department of Medicine, Cardiovascular Division, Section of Vascular Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.
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Pierce JD, Jegathesan J, Levant B, Winter M, McCarson KE, Clancy RL. Detection of dopamine receptor subtypes in the rat diaphragm. Heart Lung 2007; 36:58-63. [PMID: 17234478 DOI: 10.1016/j.hrtlng.2006.05.009] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2006] [Revised: 04/15/2006] [Accepted: 05/15/2006] [Indexed: 11/16/2022]
Abstract
BACKGROUND The administration of dopamine using an in vivo animal model has been shown to prevent and treat diaphragm fatigue. OBJECTIVE With the knowledge that dopamine stimulates alpha- and beta-adrenergic and dopamine receptors, the purpose of this study was to investigate whether dopamine receptors are present in the diaphragm. In addition, if dopamine receptors were detected, we would identify the class and subtype of dopamine receptors. METHOD Radioligand binding studies and reverse transcriptase polymerase chain reaction experiments were used. RESULTS The receptor binding studies were unable to establish whether dopamine receptors were present in the diaphragm. However, highly sensitive reverse transcriptase polymerase chain reaction experiments demonstrated that D(1)-like receptors (D(1) and D(5) receptors) were detected in the diaphragm. CONCLUSIONS This study is the first to report the class and specific subtype of dopamine receptors found in the diaphragm. By identifying dopamine receptors in the diaphragm, we have a better understanding of the mechanisms by which dopamine treats and prevents diaphragm fatigue.
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Affiliation(s)
- Janet D Pierce
- School of Nursing, University of Kansas Medical Center, Kansas City, Kansas 66160, USA
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Smith AR, Visioli F, Frei B, Hagen TM. Age-related changes in endothelial nitric oxide synthase phosphorylation and nitric oxide dependent vasodilation: evidence for a novel mechanism involving sphingomyelinase and ceramide-activated phosphatase 2A. Aging Cell 2006; 5:391-400. [PMID: 16930126 DOI: 10.1111/j.1474-9726.2006.00232.x] [Citation(s) in RCA: 82] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
Aging is the single most important risk factor for cardiovascular diseases (CVD), which are the leading cause of morbidity and mortality in the elderly. The underlying etiologies that elevate CVD risk are unknown, but increased vessel rigidity appears to be a major hallmark of cardiovascular aging. We hypothesized that post-translational signaling pathways become disrupted with age and adversely affect endothelial nitric oxide synthase (eNOS) activity and endothelial-derived nitric oxide (NO) production. Using arterial vessels and isolated endothelia from old (33-month) vs. young (3-month) F344XBrN rats, we show a loss of vasomotor function with age that is attributable to a decline in eNOS activity and NO bioavailability. An altered eNOS phosphorylation pattern consistent with its inactivation was observed: phosphorylation at the inhibitory threonine 494 site increased while phosphorylation at the activating serine 1176 site declined by 50%. Loss of phosphorylation on serine 1176 was related to higher ceramide-activated protein phosphatase 2 A activity, which was driven by a 125% increase in ceramide in aged endothelia. Elevated ceramide levels were attributable to chronic activation of neutral sphingomyelinases without a concomitant increase in ceramidase activity. This imbalance may stem from an observed 33% decline in endothelial glutathione (GSH) levels, a loss known to differentially induce neutral sphingomyelinases. Pretreating aged vessel rings with the neutral sphingomyelinase inhibitor, GW4869, significantly reversed the age-dependent loss of vasomotor function. Taken together, these results suggest a novel mechanism that at least partly explains the persistent loss of eNOS activity and endothelial-derived NO availability in aging conduit arteries.
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Affiliation(s)
- Anthony R Smith
- Linus Pauling Institute and Department of Biochemistry and Biophysics, Oregon State University, Corvallis, OR 97331, USA
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Simmons CA, Grant GR, Manduchi E, Davies PF. Spatial heterogeneity of endothelial phenotypes correlates with side-specific vulnerability to calcification in normal porcine aortic valves. Circ Res 2005; 96:792-9. [PMID: 15761200 PMCID: PMC3057118 DOI: 10.1161/01.res.0000161998.92009.64] [Citation(s) in RCA: 189] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Calcific aortic valve sclerosis involves inflammatory processes and occurs preferentially on the aortic side of endothelialized valve leaflets. Although the endothelium is recognized to play critical roles in focal vascular sclerosis, the contributions of valvular endothelial phenotypes to aortic valve sclerosis and side-specific susceptibility to calcification are poorly understood. Using RNA amplification and cDNA microarrays, we identified 584 genes as differentially expressed in situ by the endothelium on the aortic side versus ventricular side of normal adult pig aortic valves. These differential transcriptional profiles, representative of the steady state in vivo, identify globally distinct endothelial phenotypes on opposite sides of the aortic valve. Several over-represented biological classifications with putative relevance to endothelial regulation of valvular homeostasis and aortic-side vulnerability to calcification were identified among the differentially expressed genes. Of note, multiple inhibitors of cardiovascular calcification were significantly less expressed by endothelium on the disease-prone aortic side of the valve, suggesting side-specific permissiveness to calcification. However, coexisting putative protective mechanisms were also expressed. Specifically, enhanced antioxidative gene expression and the lack of differential expression of proinflammatory molecules on the aortic side may protect against inflammation and lesion initiation in the normal valve. These data implicate the endothelium in regulating valvular calcification and suggest that spatial heterogeneity of valvular endothelial phenotypes may contribute to the focal susceptibility for lesion development.
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Affiliation(s)
- Craig A Simmons
- Institute for Medicine and Engineering, University of Pennsylvania, Philadelphia PA 19104, USA.
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