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Fan WT, Zhao Y, Wu WT, Qin Y, Yan J, Liu YL, Huang WH. Redox Homeostasis Alteration in Endothelial Mechanotransduction Monitored by Dual Stretchable Electrochemical Sensors. Anal Chem 2022; 94:7425-7432. [PMID: 35543487 DOI: 10.1021/acs.analchem.2c01227] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
In vivo, endothelial cells are permanently subjected to dynamic cyclic stretch and adapt to it through the release of vasoactive substances. Among them, reactive oxygen species (ROS) and nitric oxide (NO) are indispensable redox molecules, the contents of which and their ratio are closely implicated with endothelial redox homeostasis. However, simultaneous and quantitative monitoring of ROS and NO release in endothelial mechanotransduction remains a great challenge. Herein, a stretchable electrochemical device is developed with a dual electrode based on gold nanotubes decorated with uniform and tiny platinum nanoparticles. This hybrid nanostructure endows the sensor with high sensitivity toward both hydrogen peroxide (H2O2) (as the most stable ROS) and NO electrooxidation. Importantly, the two species can be well discriminated by applying different potentials, which allows simultaneous monitoring of H2O2 and NO release in stretch-induced endothelial mechanotransduction by the same device. The results of quantitative analysis suggest that endothelial redox homeostasis and its alteration are strongly related to vascular biomechanical and biochemical milieus. Further investigation reveals that the interplay of ROS and NO signaling has an important role in the regulation of endothelial redox state. This work will greatly facilitate the deep understanding of the molecular mechanism of endothelial dysfunction and vascular disorder.
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Affiliation(s)
- Wen-Ting Fan
- College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072, China
| | - Yi Zhao
- College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072, China
| | - Wen-Tao Wu
- College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072, China
| | - Yu Qin
- College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072, China
| | - Jing Yan
- College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072, China
| | - Yan-Ling Liu
- College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072, China
| | - Wei-Hua Huang
- College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072, China
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Fan WT, Qin Y, Hu XB, Yan J, Wu WT, Liu YL, Huang WH. Stretchable Electrode Based on Au@Pt Nanotube Networks for Real-Time Monitoring of ROS Signaling in Endothelial Mechanotransduction. Anal Chem 2020; 92:15639-15646. [PMID: 33179904 DOI: 10.1021/acs.analchem.0c04015] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Vascular endothelial cells (ECs) are natively exposed to dynamic cyclic stretch and respond to it by the production of vasoactive molecules. Among them, reactive oxygen species (ROS) are closely implicated to the endothelial function and vascular homeostasis. However, the dynamic monitoring of ROS release during endothelial mechanotransduction remains a steep challenge. Herein, we developed a stretchable electrochemical sensor by decoration of uniform and ultrasmall platinum nanoparticles (Pt NPs) on gold nanotube (Au NT) networks (denoted as Au@Pt NTs). The orchestrated structure exhibited prominent electrocatalytic property toward the oxidation of hydrogen peroxide (H2O2) (as the most stable ROS) while maintaining excellent mechanical compliance of Au NT networks. Moreover, the favorable biocompatibility of Au NTs and Pt NPs promoted the adhesion and proliferation of ECs cultured thereon. These allowed in situ inducing ECs mechanotransduction and synchronously real-time monitoring of H2O2 release. Further investigation revealed that the production of H2O2 was positively correlated with the applied mechanical strains and could be boosted by other coexisting pathogenic factors. This indicates the great prospect of our proposed sensor in exploring ROS-related signaling for the deep understanding of cell mechanotransduction and vascular disorder.
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Affiliation(s)
- Wen-Ting Fan
- College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072, China
| | - Yu Qin
- College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072, China
| | - Xue-Bo Hu
- College of Chemistry and Chemical Engineering, Xinyang Normal University, Xinyang 464000, China
| | - Jing Yan
- College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072, China
| | - Wen-Tao Wu
- College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072, China
| | - Yan-Ling Liu
- College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072, China
| | - Wei-Hua Huang
- College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072, China
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Wojewodzka-Zelezniakowicz M, Gromotowicz-Poplawska A, Kisiel W, Konarzewska E, Szemraj J, Ladny JR, Chabielska E. Angiotensin-converting enzyme inhibitors attenuate propofol-induced pro-oxidative and antifibrinolytic effect in human endothelial cells. J Renin Angiotensin Aldosterone Syst 2017; 18:1470320316687197. [PMID: 28090801 PMCID: PMC5843862 DOI: 10.1177/1470320316687197] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Introduction: The aim of this study was to investigate the effects of plasma and tissue angiotensin-converting enzyme inhibitors (ACE-Is) against propofol-induced endothelial dysfunction and to elucidate the involved mechanisms in vitro. Materials and methods: We examined the effects of propofol (50 μM), quinaprilat and enalaprilat (10−5 M) on fibrinolysis (t-PA, PAI-1, TAFI antigen levels), oxidative stress parameters (H2O2 and MDA antigen levels and SOD and NADPH oxidase mRNA levels) and nitric oxide bioavailability (NO2/NO3 concentration and NOS expression at the level of mRNA) in human umbilical vein endothelial cells (HUVECs). Results: We found that both ACE-Is promoted similar endothelial fibrinolytic properties and decreased oxidative stress in vitro. Propofol alone increased the release of antifibrinolytic and pro-oxidative factors from the endothelium and increased mRNA iNOS expression. We also found that the incubation of HUVECs in the presence of propofol following ACE-Is pre-incubation caused weakness of the antifibrinolytic and pro-oxidative potential of propofol and this effect was similar after both ACE-Is. Conclusions: This observation suggests that the studied ACE-Is exerted protective effects against endothelial cell dysfunction caused by propofol, independently of hemodynamics.
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Affiliation(s)
| | | | - Wioleta Kisiel
- 2 Department of Biopharmacy, Medical University of Bialystok, Poland
| | - Emilia Konarzewska
- 1 Department of Emergency and Disaster Medicine, Medical University of Bialystok, Poland
| | - Janusz Szemraj
- 3 Department of Medical Biochemistry, Medical University of Lodz, Poland
| | - Jerzy Robert Ladny
- 1 Department of Emergency and Disaster Medicine, Medical University of Bialystok, Poland
| | - Ewa Chabielska
- 2 Department of Biopharmacy, Medical University of Bialystok, Poland
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Kiya K, Kubo T, Kawai K, Matsuzaki S, Maeda D, Fujiwara T, Nishibayashi A, Kanazawa S, Yano K, Amano G, Katayama T, Hosokawa K. Endothelial cell-derived endothelin-1 is involved in abnormal scar formation by dermal fibroblasts through RhoA/Rho-kinase pathway. Exp Dermatol 2017; 26:705-712. [PMID: 27892645 DOI: 10.1111/exd.13264] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/14/2016] [Indexed: 12/22/2022]
Abstract
Hypertrophic scars and keloids are characterized by excessive dermal deposition of extracellular matrix due to fibroblast-to-myofibroblast differentiation. Endothelin-1 (ET-1) is primarily produced by vascular endothelial cells and plays multiple roles in the wound-healing response and organ fibrogenesis. In this study, we investigated the pathophysiological significance of ET-1 and involvement of RhoA, a member of the Rho GTPases, in hypertrophic scar/keloid formation. We found that ET-1 expression on dermal microvascular endothelial cells (ECs) in hypertrophic scars and keloids was higher than that in normal skin and mature scars. We also confirmed that ET-1 induced myofibroblast differentiation and collagen synthesis in cultured human dermal fibroblasts through the RhoA/Rho-kinase pathway. Finally, since hypertrophic scar/keloid formation was most prominent in areas exposed to mechanical stretch, we examined how mechanical stretch affected ET-1 secretion in human dermal microvascular ECs, and found that mechanical stretch increased ET-1 gene expression and secretion from ECs. Taken together, these results suggest that dermal microvascular ECs release ET-1 in response to mechanical stretch, and thereby contribute to the formation of hypertrophic scars and keloids through the RhoA/Rho-kinase pathway.
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Affiliation(s)
- Koichiro Kiya
- Department of Plastic Surgery, Osaka University Graduate School of Medicine, Suita, Osaka, Japan
| | - Tateki Kubo
- Department of Plastic Surgery, Osaka University Graduate School of Medicine, Suita, Osaka, Japan
| | - Kenichiro Kawai
- Department of Plastic Surgery, Hyogo College of Medicine, Nishinomiya, Hyogo, Japan
| | - Shinsuke Matsuzaki
- Department of Pharmacology, Wakayama Medical University, Kimiidera, Wakayama, Japan
| | - Daisuke Maeda
- Department of Plastic Surgery, Osaka University Graduate School of Medicine, Suita, Osaka, Japan
| | - Toshihiro Fujiwara
- Department of Plastic Surgery, Hyogo College of Medicine, Nishinomiya, Hyogo, Japan
| | - Akimitsu Nishibayashi
- Department of Plastic Surgery, Osaka University Graduate School of Medicine, Suita, Osaka, Japan
| | - Shigeyuki Kanazawa
- Department of Plastic Surgery, Osaka University Graduate School of Medicine, Suita, Osaka, Japan
| | - Kenji Yano
- Department of Plastic Surgery, Osaka University Graduate School of Medicine, Suita, Osaka, Japan
| | - Genki Amano
- Department of Child Development and Molecular Brain Science, United Graduate School of Child Development, Osaka University, Suita, Osaka, Japan
| | - Taiichi Katayama
- Department of Child Development and Molecular Brain Science, United Graduate School of Child Development, Osaka University, Suita, Osaka, Japan
| | - Ko Hosokawa
- Department of Plastic Surgery, Osaka University Graduate School of Medicine, Suita, Osaka, Japan
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Gorąca A, Kleniewska P, Skibska B. ET-1 mediates the release of reactive oxygen species and TNF-α in lung tissue by protein kinase C α and β1. Pharmacol Rep 2015; 68:121-6. [PMID: 26721363 DOI: 10.1016/j.pharep.2015.07.007] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2014] [Revised: 07/28/2015] [Accepted: 07/29/2015] [Indexed: 01/09/2023]
Abstract
BACKGROUND The aim of this study was to determine the involvement of protein kinase C (PKC) in the ET-1 induced generation of reactive oxygen species and TNF-α in rat lungs. METHODS Experiments were performed on 6 groups of rats: Group I: saline-treated control; Group II: saline followed by endothelin-1 (ET-1) (3μg/kg); Group III: saline followed by selective PKC αβ1 inhibitor (Gö6976) (2μg/kg); Group IV: Gö6976 (2μg/kg) administered 30min before ET-1 (3μg/kg); Group V: saline followed by the PKC activator phorbol 12-myristate 13-acetate (PMA) (50μg/kg); Group VI: Gö6976 (2μg/kg) administered 30min before PMA (50μg/kg). After 5h, the animals were euthanized and their lungs were isolated for measurements. RESULTS ET-1 resulted in increase in thiobarbituric acid reactive substances (TBARS) and hydrogen peroxide (H2O2) levels and lung edema, as well as a decrease in GSH/GSSG ratio compared to the controls. The level of TNF-α also was elevated in the presence of ET-1. Administration of Gö6976 30min before ET-1 injection significantly decreased lung edema, as well as the concentrations of TBARS, H2O2 and TNF-α, but increased the GSH/GSSG redox ratio compared to ET-1. Conversely, PMA elevated lung edema and TBARS, H2O2 and TNF-α concentrations, but decreased the GSH/GSSG redox ratio compared to the control group. Treatment with Gö6976 significantly ameliorated the PMA-induced oxidative stress parameters, decreased tissue TNF-α level, and lung edema. CONCLUSION Endothelin-1 induces ROS generation, increases TNF-α level and lung edema via activation of PKC αβ1.
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Affiliation(s)
- Anna Gorąca
- Experimental and Clinical Physiology, Department of Cardiovascular Physiology, Medical University of Lodz, Łódź, Poland.
| | - Paulina Kleniewska
- Department of Immunopathology, Faculty of Biomedical Sciences and Postgraduate Training, Medical University of Lodz, Łódź, Poland
| | - Beata Skibska
- Department of Applied Pharmacy, Department of Pharmacy, Medical University of Lodz, Łódź, Poland
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Freese C, Schreiner D, Anspach L, Bantz C, Maskos M, Unger RE, Kirkpatrick CJ. In vitro investigation of silica nanoparticle uptake into human endothelial cells under physiological cyclic stretch. Part Fibre Toxicol 2014; 11:68. [PMID: 25539809 PMCID: PMC4318365 DOI: 10.1186/s12989-014-0068-y] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2014] [Accepted: 11/14/2014] [Indexed: 12/18/2022] Open
Abstract
BACKGROUND In general the prediction of the toxicity and therapeutic efficacy of engineered nanoparticles in humans is initially determined using in vitro static cell culture assays. However, such test systems may not be sufficient for testing nanoparticles intended for intravenous application. Once injected, these nanoparticles are caught up in the blood stream in vivo and are therefore in continuous movement. Physical forces such as shear stress and cyclic stretch caused by the pulsatile blood flow are known to change the phenotype of endothelial cells which line the luminal side of the vasculature and thus may be able to affect cell-nanoparticle interactions. METHODS In this study we investigated the uptake of amorphous silica nanoparticles in primary endothelial cells (HUVEC) cultured under physiological cyclic stretch conditions (1 Hz, 5% stretch) and compared this to cells in a standard static cell culture system. The toxicity of varying concentrations was assessed using cell viability and cytotoxicity studies. Nanoparticles were also characterized for the induction of an inflammatory response. Changes to cell morphology was evaluated in cells by examining actin and PECAM staining patterns and the amounts of nanoparticles taken up under the different culture conditions by evaluation of intracellular fluorescence. The expression profile of 26 stress-related was determined by microarray analysis. RESULTS The results show that cytotoxicity to endothelial cells caused by silica nanoparticles is not significantly altered under stretch compared to static culture conditions. Nevertheless, cells cultured under stretch internalize fewer nanoparticles. The data indicate that the decrease of nanoparticle content in stretched cells was not due to the induction of cell stress, inflammation processes or an enhanced exocytosis but rather a result of decreased endocytosis. CONCLUSIONS In conclusion, this study shows that while the toxic impact of silica nanoparticles is not altered by stretch this dynamic model demonstrates altered cellular uptake of nanoparticles under physiologically relevant in vitro cell culture models. In particular for the development of nanoparticles for biomedical applications such improved in vitro cell culture models may play a pivotal role in the reduction of animal experiments and development costs.
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Affiliation(s)
- Christian Freese
- REPAIR-lab, Institute of Pathology, University Medical Center of the Johannes Gutenberg University Mainz, European Institute of Excellence on Tissue Engineering and Regenerative Medicine, Mainz, Germany.
| | - Daniel Schreiner
- REPAIR-lab, Institute of Pathology, University Medical Center of the Johannes Gutenberg University Mainz, European Institute of Excellence on Tissue Engineering and Regenerative Medicine, Mainz, Germany.
| | - Laura Anspach
- REPAIR-lab, Institute of Pathology, University Medical Center of the Johannes Gutenberg University Mainz, European Institute of Excellence on Tissue Engineering and Regenerative Medicine, Mainz, Germany.
| | | | | | - Ronald E Unger
- REPAIR-lab, Institute of Pathology, University Medical Center of the Johannes Gutenberg University Mainz, European Institute of Excellence on Tissue Engineering and Regenerative Medicine, Mainz, Germany.
| | - C James Kirkpatrick
- REPAIR-lab, Institute of Pathology, University Medical Center of the Johannes Gutenberg University Mainz, European Institute of Excellence on Tissue Engineering and Regenerative Medicine, Mainz, Germany.
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TAKASE SHINYA, LEROND LAURANCE, BERGAN JOHNJ, SCHMID-SCHÖNBEIN GEERTW. The Inflammatory Reaction During Venous Hypertension in the Rat. Microcirculation 2013. [DOI: 10.1111/j.1549-8719.2000.tb00741.x] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Spironolactone rescues Dot1a-Af9-mediated repression of endothelin-1 and improves kidney injury in streptozotocin-induced diabetic rats. PLoS One 2012; 7:e47360. [PMID: 23077601 PMCID: PMC3471839 DOI: 10.1371/journal.pone.0047360] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2012] [Accepted: 09/11/2012] [Indexed: 01/01/2023] Open
Abstract
The molecular mechanism linking aldosterone and endothelin-1 in the development of diabetic nephropathy has not been completely elucidated. Here, we provide evidence showing that streptozotocin-induced diabetic rats have significantly increased aldosterone and endothelin-1 in the kidney tissue and markedly decreased expression of Dot1a and Af9. Blocking aldosterone with spironolactone significantly reduced proteinuria, glomerulosclerosis, tubulointerstitial injury and endothelin-1 expression, and significantly increased Dot1a and Af9 expression. Increasing Dot1a and Af9 expression by spironolactone or by stable transfection led to impaired endothelin-1 expression in NRK-52 cells. In contrast, downregulation of Dot1a and Af9 by aldosterone in NRK-52E cells caused upregulation of endothelin-1. Genetic inactivation of Dot1l, which encodes Dot1a, in Aqp2-expressing principal cells of mouse kidney impaired association of Dot1a and H3 dimethyl K79 with the specific subregions of endothelin-1 promoter, and upregulates endothelin-1 mRNA and protein expression. Our data suggest that Dot1a and Af9 repress endothelin-1 in vitro and in vivo. Excessive aldosterone induces kidney injury, in part possibly by downregulating Dot1a and Af9, and thus relieving Dot1a-Af9-mediated repression to increase endothelin-1 transcription. Spironolactone ameliorates kidney injury in Streptozotocin-induced diabetic rats, possibly by restoring Dot1a-Af9-mediated repression to reduce endothelin-1 expression. Therefore, Dot1a and Af9 as aldosterone-downregulated targets are negative regulators of endothelin-1 transcription in vitro and in vivo, and may be considered as new potential therapeutic targets of kidney injury in diabetes.
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Stricklett PK, Strait KA, Kohan DE. Novel regulation of endothelin-1 promoter activity by protein kinase C. Cell Biochem Biophys 2012; 61:643-50. [PMID: 21818684 DOI: 10.1007/s12013-011-9250-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Endothelin-1 (ET-1) is produced in unusually large amounts by the renal collecting duct and acts locally to control renal salt and water excretion and arterial pressure; disorders of collecting duct ET-1 activity can cause marked hypertension. The mechanisms regulating collecting duct ET-1 synthesis are, however, poorly understood. In this study, we investigated the role of protein kinase C (PKC), a known regulator of ET-1 production in endothelial cells, in (1) the control of collecting duct ET-1 production; and (2) the modulation of ET-1 promoter region activity. Cultured rat inner medullary collecting duct (IMCD) cells were studied. Calphostin C, a PKC inhibitor, greatly reduced IMCD ET-1 release. Sustained exposure to phorbol myristate acetate (PMA) also decreased ET-1 secretion. PKC inhibition decreased steady-state ET-1 mRNA content. A brief exposure (15 min) to PMA augmented ET-1 mRNA levels, while prolonged PMA exposure (120 min) reduced ET-1 mRNA content, PKC inhibition did not affect ET-1 mRNA stability. Transfection of ET-1 promoter-luciferase reporter constructs into IMCD cells demonstrated that PKC inhibition reduced activity of only the larger promoter fragments (containing at least 1,725 bp 5' to the ET-1 gene transcription start site). Mutation of a previously identified AP-1 site at -186 in the ET-1 promoter greatly reduced activity of transfected ET-1 promoter-reporter constructs (containing 366 or 1,725 bp 5' to the transcription start site); however, this region appears not to be regulated by PKC in IMCD cells. In summary, PKC stimulates collecting duct ET-1 synthesis via transcriptional activation of the ET-1 promoter. Such transcriptional activation occurs at a heretofore undescribed PKC-regulated region of the ET-1 promoter.
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Affiliation(s)
- Peter K Stricklett
- Division of Nephrology, University of Utah Health Sciences Center, Salt Lake City, UT 84132, USA
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Abstract
Over two decades of research have demonstrated that the peptide hormone endothelin-1 (ET-1) plays multiple, complex roles in cardiovascular, neural, pulmonary, reproductive, and renal physiology. Differential and tissue-specific production of ET-1 must be tightly regulated in order to preserve these biologically diverse actions. The primary mechanism thought to control ET-1 bioavailability is the rate of transcription from the ET-1 gene (edn1). Studies conducted on a variety of cell types have identified key transcription factors that govern edn1 expression. With few exceptions, the cis-acting elements bound by these factors have been mapped in the edn1 regulatory region. Recent evidence has revealed new roles for some factors originally believed to regulate edn1 in a tissue or hormone-specific manner. In addition, other mechanisms involved in epigenetic regulation and mRNA stability have emerged as important processes for regulated edn1 expression. The goal of this review is to provide a comprehensive overview of the specific factors and signaling systems that govern edn1 activity at the molecular level.
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Affiliation(s)
- Lisa R Stow
- Department of Biochemistry and Molecular Biology, University of Florida, Gainesville, FL 32610, USA
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Lindstedt I, Xu CB, Zhang Y, Edvinsson L. Increased perfusion pressure enhances the expression of endothelin (ETB) and angiotensin II (AT1, AT2) receptors in rat mesenteric artery smooth muscle cells. Blood Press 2009; 18:78-85. [PMID: 19353416 DOI: 10.1080/08037050902850184] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
In the present study, we hypothesized that changes in perfusion pressure result in altered expression of mRNA and protein encoding for the ETA-, ETB-, AT1- and AT2-receptors in rat mesenteric vessels. Segments of the rat mesenteric artery were cannulated with glass micropipettes, pressurized and luminally perfused in a perfusion chamber. After either exposure to no ("organ culture" (0 mmHg)), normal (85/75 mmHg) or high pressure (160/150 mmHg) at constant flow for 1-17 h, the vessel segments were snap frozen and real-time polymerase chain reaction was performed to quantify the ET- and AT-receptor mRNA content, or immersed in a fixative solution, dehydrated, frozen, cut in a cryostat and immunohistology stained for ET- and AT-receptor protein. The mRNA expressions of ETB and of AT2 were significantly enhanced in vessels exposed to high perfusion pressure, compared with normal and no perfusion pressure at 4 h. In concordance, AT1-, AT2- and ETB-receptor proteins were up-regulated at 17 h of high perfusion pressure. In conclusion, the results from our rat perfusion model suggest a more important role of shear stress than pure pressure alone and may serve as a surrogate model for studies designed to investigate hypertension mechanisms.
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Affiliation(s)
- Isak Lindstedt
- Division of Experimental Vascular Research, Institute of Clinical Science in Lund, Lund University, Lund, Sweden.
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Chiou CS, Lin JW, Kao PF, Liu JC, Cheng TH, Chan P. EFFECTS OF HESPERIDIN ON CYCLIC STRAIN-INDUCED ENDOTHELIN-1 RELEASE IN HUMAN UMBILICAL VEIN ENDOTHELIAL CELLS. Clin Exp Pharmacol Physiol 2008; 35:938-43. [DOI: 10.1111/j.1440-1681.2008.04939.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Bi WF, Yang HY, Liu JC, Cheng TH, Chen CH, Shih CM, Lin H, Wang TC, Lian WS, Chen JJ, Chiu HC, Chang NC. INHIBITION OF CYCLIC STRAIN-INDUCED ENDOTHELIN-1 SECRETION BY TETRAMETHYLPYRAZINE. Clin Exp Pharmacol Physiol 2005; 32:536-40. [PMID: 16026512 DOI: 10.1111/j.1440-1681.2005.04227.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
1. Chuanxiong is a Chinese herb that has been used widely in China to treat vascular disorders. 2,3,5,6-Tetramethylpyrazine (TMP) is one of the major components purified from chuanxiong. Many studies have demonstrated that TMP is effective in the treatment of cardiovascular diseases. However, the mechanism of action by which TMP exerts relaxation in vascular vessels remains unclear. 2. Endothelin (ET)-1 is a potent vasopressor synthesised by endothelial cells both in culture and in vivo. The aims of the present study were to test the hypothesis that TMP may alter strain-induced ET-1 secretion and to identify the putative underlying signalling pathways in endothelial cells. 3. We showed that TMP inhibits strain-induced ET-1 secretion. 2,3,5,6-Tetramethylpyrazine also inhibits the strain-induced formation of reactive oxygen species (ROS) and phosphorylation of extracellular signal-regulated kinases (ERK) 1/2. Furthermore, pretreating cells with TMP or the anti-oxidant N-acetyl-cysteine decreased strain-induced increases in ET-1 secretion and ERK1/2 phosphorylation. Using a reporter gene assay, TMP and N-acetyl-cysteine were demonstrated to also attenuate the strain-induced activity of the activator protein-1 reporter. 4. In summary, we have demonstrated, for the first time, that TMP inhibits strain-induced ET-1 gene expression, in part by interfering with the ERK1/2 pathway via attenuation of ROS formation. Thus, the present study provides important new insights into the molecular pathways that may contribute to the proposed beneficial effects of TMP in the vascular system.
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Affiliation(s)
- Wei-Fung Bi
- Department of Medicine, Taipei Medical University Hospital, Taipei, Taiwan ROC
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Ostrow LW, Sachs F. Mechanosensation and endothelin in astrocytes--hypothetical roles in CNS pathophysiology. ACTA ACUST UNITED AC 2004; 48:488-508. [PMID: 15914254 DOI: 10.1016/j.brainresrev.2004.09.005] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2003] [Revised: 08/19/2004] [Accepted: 09/09/2004] [Indexed: 01/23/2023]
Abstract
Endothelin (ET) is a potent autocrine mitogen produced by reactive and neoplastic astrocytes. ET has been implicated in the induction of astrocyte proliferation and other transformations engendered by brain pathology, and in promoting the malignant behavior of astrocytomas. Reactive astrocytes containing ET are found in the periphery/penumbra of a wide array of CNS pathologies. Virtually all brain pathology deforms the surrounding parenchyma, either by direct mass effect or edema. Mechanical stress is a well established stimulus for ET production and release by other cell types, but has not been well studied in the brain. However, numerous studies have illustrated that astrocytes can sense mechanical stress and translate it into chemical messages. Furthermore, the ubiquitous reticular meshwork formed by interconnected astrocytes provides an ideal morphology for sensing and responding to mechanical disturbances. We have recently demonstrated stretch-induced ET production by astrocytes in vitro. Inspired by this finding, the purpose of this article is to review the literature on (1) astrocyte mechanosensation, and (2) the endothelin system in astrocytes, and to consider the hypothesis that mechanical induction of the ET system may influence astrocyte functioning in CNS pathophysiology. We conclude by discussing evidence supporting future investigations to determine whether specific inhibition of stretch-activated ion channels may represent a novel strategy for treating or preventing CNS disturbances, as well as the relevance to astrocyte-derived tumors.
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Affiliation(s)
- Lyle W Ostrow
- Department of Physiology and Biophysics, S.U.N.Y. at Buffalo, School of Medicine and Biomedical Sciences, Buffalo, NY 14214, USA
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Schiffrin EL, Touyz RM. From bedside to bench to bedside: role of renin-angiotensin-aldosterone system in remodeling of resistance arteries in hypertension. Am J Physiol Heart Circ Physiol 2004; 287:H435-46. [PMID: 15277186 DOI: 10.1152/ajpheart.00262.2004] [Citation(s) in RCA: 185] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- Ernesto L Schiffrin
- Canadian Institutes of Health Research Multidisciplinary Research Group on Hypertension and Hypertension Clinic, Clinical Research Institute of Montréal, Quebec, Canada H2W 1R7.
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Juan SH, Chen JJ, Chen CH, Lin H, Cheng CF, Liu JC, Hsieh MH, Chen YL, Chao HH, Chen TH, Chan P, Cheng TH. 17β-Estradiol inhibits cyclic strain-induced endothelin-1 gene expression within vascular endothelial cells. Am J Physiol Heart Circ Physiol 2004; 287:H1254-61. [PMID: 15130882 DOI: 10.1152/ajpheart.00723.2003] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
It has been well documented previously that 17β-estradiol (E2) exerts a protective effect on cardiovascular tissue. The possible role of E2in the regulation of endothelin (ET)-1 production has been previously reported, although the complex mechanisms by which E2inhibits ET-1 expression are not completely understood. The aims of this study were to examine whether E2was able to alter strain-induced ET-1 gene expression and also to identify the putative underlying signaling pathways that exist within endothelial cells. For cultured endothelial cells, E2(1–100 nM), but not 17α-estradiol, inhibited the level of strain-induced ET-1 gene expression and also peptide secretion. This inhibitory effect elicited by E2was able to be prevented by the coincubation of endothelial cells with the estrogen receptor antagonist ICI-182,780 (1 μM). E2also inhibited strain-enhanced NADPH oxidase activity and intracellular reactive oxygen species (ROS) generation as measured by the redox-sensitive fluorescent dye 2′,7′-dichlorofluorescin diacetate and the level of extracellular signal-regulated kinase (ERK) phosphorylation. Furthermore, the presence of E2and antioxidants such as N-acetylcysteine and diphenylene iodonium were able to elicit a decrease in the level of strain-induced ET-1 secretion, ET-1 promoter activity, ET-1 mRNA, ERK phosphorylation, and activator protein-1 binding activity. In summary, we demonstrated, for the first time, that E2inhibits strain-induced ET-1 gene expression, partially by interfering with the ERK pathway via the attenuation of strain-induced ROS generation. Thus this study delivers important new insight regarding the molecular pathways that may contribute to the proposed beneficial effects of estrogen on the cardiovascular system.
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Affiliation(s)
- Shu-Hui Juan
- Graduate Institute of Medical Sciences and Department of Physiology, School of Medicine, Taipei Medical University, Republic of China
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18
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Wan S, Yim APC, Johnson JL, Shukla N, Angelini GD, Smith FCT, Dashwood MR, Jeremy JY. The endothelin 1a receptor antagonist BSF 302146 is a potent inhibitor of neointimal and medial thickening in porcine saphenous vein–carotid artery interposition grafts. J Thorac Cardiovasc Surg 2004; 127:1317-22. [PMID: 15115988 DOI: 10.1016/j.jtcvs.2003.06.018] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
OBJECTIVE Late saphenous vein graft failure after coronary artery bypass graft surgery is initiated by medial thickening and neointima formation, both of which are mediated by the proliferation of vascular smooth muscle cells. Because porcine vein grafts contain high levels of endothelin 1 receptor subtypes and endothelin 1 promotes the proliferation of vascular smooth muscle cells, the effect of administration of the endothelin 1(A) receptor antagonist BSF 302146 ([+]-[S]-2-[4,6-dimethyl-pyrimidin-2-yloxy]-3,3-diphenyl-butanoic acid) on porcine vein graft thickening was investigated. METHODS Saphenous vein-carotid artery interposition grafting was performed in 4 groups of large white pigs (30-35 kg, n = 10 for each group). BSF 302146 was administered orally (3, 10, and 30 mg x kg(-1) x d(-1)) for 4 weeks to one group of pigs, and placebo was administered to the other group (control animals). Pigs were then anesthetized, and the grafts were removed and fixed at 100 mm Hg with 4% paraformaldehyde. Histologic sections were prepared, and graft morphometry was carried out by using computer-aided planimetry. RESULTS In vein grafts from animals treated with BSF 302146 compared with grafts from control animals (untreated), there were significant dose-dependent reductions in the increase in medial thickness and neointimal thickness, an increase in luminal area, and a decrease in proliferating cell nuclear antigen-positive cells in the medial-intimal area. CONCLUSIONS The administration of BSF 302146 reduces graft thickening and promotes positive remodeling through an endothelin 1(A)-mediated effect on vascular smooth muscle cell replication. The administration of this endothelin 1(A) receptor antagonist might therefore be therapeutically effective in preventing late vein graft failure in patients undergoing coronary artery bypass grafting.
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Affiliation(s)
- Song Wan
- Department of Surgery, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong, China
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19
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Grikscheit TC. Tissue engineering of the gastrointestinal tract for surgical replacement: a nutrition tool of the future? Proc Nutr Soc 2004; 62:739-43. [PMID: 14692609 DOI: 10.1079/pns2003289] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Optimal nutrition depends on the multiple complex functions performed by the gastrointestinal tract, which range from basic functions such as storage, conduit and mechanical processing to more finely regulated capabilities such as vectorial transport, immune defence and cell signalling. Surgical strategies to supply lacking gastrointestinal tract tissues have relied on either replacement by proxy (surgical substitution) or the introduction of prostheses. Tissue engineering seeks to replace missing tissues with engineered tissues that more accurately reproduce the native physiological and anatomical milieu. It is now possible to engineer several areas of the gastrointestinal tract with high fidelity, and to employ tissue-engineered bowel in replacement in animal models. These replacement models have reflected excellent anatomical and physiological recapitulation of native bowel by the tissue-engineered constructs in vivo.
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Affiliation(s)
- Tracy C Grikscheit
- Department of Surgery, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114, USA.
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20
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Liu JC, Chen JJ, Chan P, Cheng CF, Cheng TH. Inhibition of Cyclic Strain-Induced Endothelin-1 Gene Expression by Resveratrol. Hypertension 2003; 42:1198-205. [PMID: 14623829 DOI: 10.1161/01.hyp.0000103162.76220.51] [Citation(s) in RCA: 73] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Resveratrol is a phytoestrogen naturally found in grapes and is among the major constituents of wine thought to have a cardioprotective effect. Endothelin-1 (ET-1) is a potent vasopressor synthesized by endothelial cells both in culture and in vivo. The aims of this study were to test the hypothesis that resveratrol may alter strain-induced ET-1 gene expression and to identify the putative underlying signaling pathways in endothelial cells. We show that resveratrol indeed potently inhibits strain-induced ET-1 secretion, ET-1 mRNA level, and ET-1 promoter activity. Resveratrol also inhibits strain-increased NADPH oxidase activity, reactive oxygen species formation, and extracellular signal–regulated kinases1/2 (ERK1/2) phosphorylation. Furthermore, pretreating cells with resveratrol or antioxidant
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-acetyl-cysteine decreases strain-increased or hydrogen peroxide–increased ET-1 secretion, ET-1 promoter activity, and ET-1 mRNA and ERK1/2 phosphorylation. Using both the electrophoretic mobility shift assay and a reporter gene assay, resveratrol and
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-acetyl-cysteine also attenuated the strain-stimulated activator protein-1 binding activity and activator protein-1 reporter activity. In summary, we demonstrate for the first time that resveratrol inhibits strain-induced ET-1 gene expression, partially by interfering with the ERK1/2 pathway through attenuation of reactive oxygen species formation. Thus, this study provides important new insights in the molecular pathways that may contribute to the proposed beneficial effects of resveratrol in the cardiovascular system.
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Affiliation(s)
- Ju-Chi Liu
- Department of Medicine, Taipei Medical University, Wan Fang Hospital, Wen-Shan District, Taipei, Taiwan
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21
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Wang DS, Proffit D, Tsao PS. Mechanotransduction of endothelial oxidative stress induced by cyclic strain. ENDOTHELIUM : JOURNAL OF ENDOTHELIAL CELL RESEARCH 2003; 8:283-91. [PMID: 11824481 DOI: 10.3109/10623320109090806] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Atherosclerotic lesions display a nonuniform distribution throughout the vascular tree. Mechanical forces produced by local alterations in blood flow may play an important role in the localization of atherosclerosis. One such force, cyclic strain, has been hypothesized to promote atherogenesis by inducing oxidative stress in endothelial cells, resulting in enhanced endothelial adhesiveness for monocytes. To investigate the signal transduction systems involved, human aortic endothelial cells were plated on flexible silicone strips that were either non-coated or adsorbed with poly-L-lysine, vitronectin, fibronectin, or collagen I. Cells were then subjected to uniform sinusoidal stretch (10%) for 6 h. Endothelial superoxide anion production was increased in cells exposed to cyclic strain compared to static conditions. Furthermore, endothelial oxidative response to stretch was matrix protein-dependent, whereas cells grown on fibronectin and collagen I produced significantly more superoxide. The oxidative response to cyclic strain was reduced by coincubation with RGD peptides, blocking antibodies to alpha2- and beta-integrins antibodies, as well as inhibitors of protein kinase C. To investigate the effect of oxidative stress on gene transcription, endothelial cells grown on collagen I were transfected with an NFkappaB-sensitive luciferase construct. Cells that underwent cyclic strain displayed a tenfold induction of NFkappaB activation compared to static controls. Strain-induced luciferase activity was blunted by coincubation with RGD peptides or calphostin C. Thus, exposure of endothelial cells to cyclic strain led to integrin activation of a PKC-sensitive pathway that results in increased superoxide anion production and mobilization of NFkappaB.
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Affiliation(s)
- D S Wang
- Department of Medicine, Stanford University, School of Medicine, CA 94305-5406, USA
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22
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Tschumperlin DJ, Shively JD, Kikuchi T, Drazen JM. Mechanical stress triggers selective release of fibrotic mediators from bronchial epithelium. Am J Respir Cell Mol Biol 2003; 28:142-9. [PMID: 12540481 DOI: 10.1165/rcmb.2002-0121oc] [Citation(s) in RCA: 113] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Transforming growth factor-beta (TGF-beta) and endothelin (ET) are found in elevated amounts in the airways of individuals with asthma. The cellular source of these peptides and their role in mediating the airway fibrosis of chronic asthma are unknown. In response to mechanical stresses similar to those occurring in vivo during airway constriction, bronchial epithelial cells increase the steady-state level of mRNA for both ET-1 and ET-2, followed by increased release of ET protein. Mechanical stress also enhances release of TGF-beta2 from a preformed cell-associated pool. TGF-beta2 and ET act individually and, more importantly, synergistically to promote fibrotic protein synthesis in reporter fibroblasts. To confirm the role of these intermediates in stress-induced fibrosis, conditioned medium from mechanically stressed bronchial epithelial cells was shown to elicit fibrotic protein synthesis in reporter fibroblasts; this effect was significantly inhibited by combined treatment with ET receptor antagonists and a neutralizing antibody to TGF-beta2. These data are consistent with a primary pathogenic role for mechanical stress-induced release of both TGF-beta2 and ET in the subepithelial fibrosis that characterizes chronic asthma.
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Affiliation(s)
- Daniel J Tschumperlin
- Pulmonary and Critical Care Division, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA
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23
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Cheng JJ, Chao YJ, Wang DL. Cyclic strain activates redox-sensitive proline-rich tyrosine kinase 2 (PYK2) in endothelial cells. J Biol Chem 2002; 277:48152-7. [PMID: 12368297 DOI: 10.1074/jbc.m110937200] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Proline-rich tyrosine kinase 2 (PYK2), structurally related to focal adhesion kinase, has been shown to play a role in signaling cascades. Endothelial cells (ECs) under hemodynamic forces increase reactive oxygen species (ROS) that modulate signaling pathways and gene expression. In the present study, we found that bovine ECs subjected to cyclic strain rapidly induced phosphorylation of PYK2 and Src kinase. This strain-induced PYK2 and Src phosphorylation was inhibited by pretreating ECs with an antioxidant N-acetylcysteine. Similarly, ECs exposed to H(2)O(2) increased both PYK2 and Src phosphorylation. An increased association of Src to PYK2 was observed in ECs after cyclic strain or H(2)O(2) exposure. ECs treated with an inhibitor to Src (PPI) greatly reduced Src and PYK2 phosphorylation, indicating that Src mediated PYK2 activation. Whereas the protein kinase C (PKC) inhibitor (calphostin C) pretreatment was shown to inhibit strain-induced NADPH oxidase activity, ECs treated with either calphostin C or the inhibitor to NADPH oxidase (DPI) reduced strain-induced ROS levels and then greatly inhibited the Src and PYK2 activation. In contrast to the activation of PYK2 and Src with calcium ionophore (ionomycin), ECs treated with a Ca(2+) chelator inhibited both phosphorylation, indicating that PYK2 and Src activation requires Ca(2+). ECs transfected with antisense to PKCalpha, but not antisense to PKCepsilon(,) reduced cyclic strain-induced PYK2 activation. These data suggest that cyclic strain-induced PYK2 activity is mediated via Ca(2+)-dependent PKCalpha that increases NADPH oxidase activity to produce ROS crucial for Src and PYK2 activation. ECs under cyclic strain thus activate redox-sensitive PYK2 via Src and PKC, and this PYK2 activation may play a key role in the signaling responses in ECs under hemodynamic influence.
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Affiliation(s)
- Jing-Jy Cheng
- Cardiovascular Division, Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan 11529
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24
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Schwarzacher SP, Tsao PS, Ward M, Hayase M, Niebauer J, Cooke JP, Yeung AC. Effects of stenting on adjacent vascular distensibility and neointima formation: role of nitric oxide. Vasc Med 2002; 6:139-44. [PMID: 11789967 DOI: 10.1177/1358836x0100600303] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Intravascular stents increase long-term patency but their effects on the vascular mechanics of adjacent segments have not been studied. In this study, stents were deployed in the rabbit abdominal aorta after 1 week of normal diet, 1% cholesterol diet or 1% cholesterol diet with L-nitro arginine (L-NA 60 mg/l water). Intravascular ultrasound showed a small distal decrease in vessel distensibility (area/pressure * 100) before stenting. Distensibility was almost abolished by stenting (0.12 +/- 0.01, p < 0.001), but was increased proximal to the stent and decreased distal to the stent both acutely (proximal: 1.18 +/- 0.10 vs distal: 0.65 +/- 0.06, p < 0.001), and at 4 weeks (proximal: 1.05 +/- 0.08 vs distal: 0.37 +/- 0.07, p < 0.001). Nitric oxide (NO) activity was enhanced proximal to and within the stent, and remained constant distal to the stent, (versus control, proximal: 57 +/- 23%, stent: 136 +/- 35%, distal: 2 +/- 12%, p < 0.01). The I/M ratio was significantly higher proximal to and within the stent than in the distal segment (proximal: 0.40 +/- 0.10, stent: 0.37 +/- 0.12, distal: 0.12 +/- 0.11, p < 0.01). NO blockade with L-NA prevented hyperdistensibility proximally, and significantly increased the I/M ratio within the stent and distally (stent: 0.81 +/- 0.19, distal: 0.30 +/- 0.10, p < 0.05) but not proximally (0.38 +/- 0.09). In conclusion, aortic stenting increases proximal vascular distensibility and intimal lesion formation. Nitric oxide blockade augments intimal growth within but not proximal to the stent.
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Affiliation(s)
- S P Schwarzacher
- University of Innsbruck School of Medicine, Division of Cardiology, Innsbruck, Austria
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25
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Rossi GP, Seccia TM, Nussdorfer GG. Reciprocal regulation of endothelin-1 and nitric oxide: relevance in the physiology and pathology of the cardiovascular system. INTERNATIONAL REVIEW OF CYTOLOGY 2002; 209:241-72. [PMID: 11580202 DOI: 10.1016/s0074-7696(01)09014-3] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
The endothelium plays a crucial role in the regulation of cardiovascular structure and function by releasing several mediators in response to biochemical and physical stimuli. These mediators are grouped into two classes: (1) endothelium-derived constricting factors (EDCFs) and (2) endothelium-derived relaxing factors (EDRFs), the roles of which are considered to be detrimental and beneficial, respectively. Endothelin-1 (ET-1) and nitric oxide (NO) are the prototypes of EDCFs and EDRFs, respectively, and their effects on the cardiovascular system have been studied in depth. Numerous conditions characterized by an impaired availability of NO have been found to be associated with enhanced synthesis of ET-1, and vice versa, thereby suggesting that these two factors have a reciprocal regulation. Experimental studies have provided evidence that ET-1 may exert a bidirectional effect by either enhancing NO production via ETB receptors located in endothelial cells or blunting it via ETA receptors prevalently located in the vascular smooth muscle cells. Conversely, NO was found to inhibit ET-1 synthesis in different cell types. In vitro and in vivo studies have started to unravel the molecular mechanisms involved in this complex interaction. It has been clarified that several factors affect in opposite directions the transcription of preproET-1 and NO-synthase genes, nuclear factor-KB and peroxisome proliferator-activated receptors playing a key role in these regulatory mechanisms. ET-1 and NO interplay seems to have a great relevance in the physiological regulation of vascular tone and blood pressure, as well as in vascular remodeling. Moreover, an imbalance between ET-1 and NO systems may underly the mechanisms involved in the pathogenesis of systemic and pulmonary hypertension and atherosclerosis.
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Affiliation(s)
- G P Rossi
- Department of Clinical and Experimental Medicine, University Hospital, University of Padua, Italy
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26
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Cattaruzza M, Eberhardt I, Hecker M. Mechanosensitive transcription factors involved in endothelin B receptor expression. J Biol Chem 2001; 276:36999-7003. [PMID: 11457849 DOI: 10.1074/jbc.m105158200] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Growing evidence suggests an involvement of the endothelin B receptor (ET(B)-R) in blood pressure-dependent arterial remodeling. To study the molecular mechanisms leading to deformation-induced ET(B)-R expression, we have cultured rat aortic smooth muscle cells on flexible elastomers and, when grown to 70% confluence, periodically stretched them for 6 h (15% elongation, 0.5 Hz). The cells responded with an increase both in ET(B)-R mRNA (12-fold compared with control) and protein (4-fold). According to nuclear run-on analysis this increase in ET(B)-R expression occurred at the level of transcription. Among various kinase pathways, Rho kinase (ROCK) and p38 mitogen-activated protein kinase (p38 MAPK) mediated part of the deformation-induced increase in ET(B)-R expression, as judged by the inhibitory effect of Y27632 (1 microm, 38% inhibition) and SB202190 (10 microm, 44% inhibition), respectively. Gel shift assaying of the three transcription factors principally activated by these kinases revealed a transient deformation-induced activation of activator protein-1 (AP-1) and CCAAT/enhancer-binding protein (C/EBP), but not activating transcription factor, that was sensitive to both Y27632 and SB212190. The potential role of AP-1 and C/EBP in deformation-induced ET(B)-R expression was verified both by using decoy oligodeoxynucleotides mimicking the DNA-binding sites of these transcription factors and a nuclear run-on-based assay employing specific antibodies directed against AP-1 and C/EBP. Both techniques unequivocally demonstrated that activation of these transcription factors, namely that of C/EBP beta, contribute to the increase of ET(B)-R gene expression in response to cyclic stretch.
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Affiliation(s)
- M Cattaruzza
- Department of Cardiovascular Physiology, University of Goettingen, Humboldtallee 23, 37073 Goettingen, Germany
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27
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Cheng TH, Shih NL, Chen SY, Loh SH, Cheng PY, Tsai CS, Liu SH, Wang DL, Chen JJ. Reactive oxygen species mediate cyclic strain-induced endothelin-1 gene expression via Ras/Raf/extracellular signal-regulated kinase pathway in endothelial cells. J Mol Cell Cardiol 2001; 33:1805-14. [PMID: 11603923 DOI: 10.1006/jmcc.2001.1444] [Citation(s) in RCA: 89] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Endothelin-1 (Et-1) is a peptide synthesized by endothelial cells (ECs) both in culture and in vivo. Cyclic strain induces gene expression of Et-1, however, the molecular mechanisms remain unclear. Since cyclic strain induces a sustained increase in intracellular reactive oxygen species (ROS), we hypothesized that the ROS could be a modulator in strain-induced Et-1 gene expression. Human umbilical vein ECs (HUVECs) subjected to cyclic strain had increased Et-1 secretion. Pretreatment of HUVECs with antioxidants, catalase (300 U/ml) or 1,3-dimethyl-2-thiourea (DMTU, 0.1 mm), abolished the strain-induced Et-1 release. ECs strained for 6 h had elevated Et-1 mRNA levels. In contrast, ECs treated with catalase or DMTU did not have increase Et-1 mRNA levels stimulated by cyclic strain. Bovine aortic ECs (BAECs) transfected with fusion plasmid containing Et-1 5'-flanking sequence (4.4 kb) and chloramphenicol acetyltransferase reporter gene produced a maximal Et-1 promoter activity after undergoing strain for 6 h, whereas pretreatment with catalase decreased this activity. BAECs cotransfected with a dominant negative mutant of Ras (RasN17), Raf-1 (Raf301), or catalytically inactive mutant of extracellular signal-regulated kinase (mERK2) had inhibited strain-induced Et-1 promoter activity, indicating the Ras/Raf/ERK pathway was involved; moreover, ERK phosphorylation was induced in ECs which were strained. This strain-activated ERK phosphorylation was attenuated in the presence of catalase. Functional analysis of the Et-1 promoter with site-directed mutagenesis indicates that the activator protein-1 (AP-1) binding site had to be within 143 base-pairs upstream of transcription initiation site for strain-induced promoter activity. Pretreatment of ECs with catalase also decreased the strain-induced promoter activity in the minimal construct (-143 bp). Our data demonstrate that strain-induced Et-1 gene expression is modulated by ROS via Ras/Raf/ERK signaling pathway, and indicate the responsiveness of the AP-1 binding site for strain-induced Et-1 expression.
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Affiliation(s)
- T H Cheng
- Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan, ROC
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28
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Cheng JJ, Wung BS, Chao YJ, Wang DL. Sequential activation of protein kinase C (PKC)-alpha and PKC-epsilon contributes to sustained Raf/ERK1/2 activation in endothelial cells under mechanical strain. J Biol Chem 2001; 276:31368-75. [PMID: 11399752 DOI: 10.1074/jbc.m011317200] [Citation(s) in RCA: 64] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Endothelial cells (ECs) are constantly subjected to hemodynamic forces including cyclic pressure-induced strain. The role of protein kinase C (PKC) in cyclic strain-treated ECs was studied. PKC activities were induced as cyclic strain was initiated. Cyclic strain to ECs caused activation of PKC-alpha and -epsilon. The translocation of PKC-alpha and -epsilon but not PKC-beta from the cytosolic to membrane fraction was observed. An early transient activation of PKC-alpha versus a late but sustained activation of PKC-epsilon was shown after the onset of cyclic strain. Consistently, a sequential association of PKC-alpha and -epsilon with the signaling molecule Raf-1 was shown. ECs treated with a PKC inhibitor (calphostin C) abolished the cyclic strain-induced Raf-1 activation. ECs under cyclic strain induced a sustained activation of extracellular signal-regulated protein kinases (ERK1/2), which was inhibited by treating ECs with calphostin C. ECs treated with a specific Ca(2+)-dependent PKC inhibitor (Go 6976) showed an inhibition in the early phase of ERK1/2 activation but not in the late and sustained phase. ECs transfected with the antisense to PKC-alpha, the antisense to PKC-epsilon, or the inhibition peptide to PKC-epsilon reduced strain-induced ERK1/2 phosphorylation in a temporal manner. PKC-alpha mediated mainly the early ERK1/2 activation, whereas PKC-epsilon was involved in the sustained ERK1/2 activation. Strained ECs increased transcriptional activity of Elk1 (an ERK1/2 substrate). ECs transfected with the antisense to each PKC isoform reduced Elk1 and monocyte chemotactic protein-1 promotor activity. Our findings conclude that a sequential activation of PKC isoform (alpha and epsilon) contribute to Raf/ERK1/2 activation, and PKC-epsilon appears to play a key role in endothelial adaptation to hemodynamic environment.
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Affiliation(s)
- J J Cheng
- Cardiovascular Division, Institute of Biomedical Sciences, Academia Sinica, 11529 Taipei, Taiwan, Republic of China
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29
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Loennechen JP, Støylen A, Beisvag V, Wisløff U, Ellingsen O. Regional expression of endothelin-1, ANP, IGF-1, and LV wall stress in the infarcted rat heart. Am J Physiol Heart Circ Physiol 2001; 280:H2902-10. [PMID: 11356651 DOI: 10.1152/ajpheart.2001.280.6.h2902] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
We hypothesized that myocardial infarction induces regional and temporal differences in endothelin-1 (ET-1), atrial natriuretic peptide (ANP), and insulin-like growth factor-1 (IGF-1) gene expression that correlate with left ventricular (LV) wall stress. Echocardiography and LV pressure measurements were performed in coronary artery-ligated or sham-operated rats. Gene expression was measured by competitive RT-PCR in the infarct, border zone, and remote area and in regionally isolated cardiomyocytes. ET-1 and IGF-1 expression was highest in the infarcted myocardium, whereas ANP expression was highest in noninfarcted myocardium. For all genes, remote area expression was highest after 7 days. At 42 days, ANP maintained maximum expression, ET-1 decreased to 50% of peak levels, and IGF-1 was normalized. Cardiomyocyte expression followed the same pattern as in the myocardium except for a markedly lower IGF-1 expression. Diastolic wall stress was the best hemodynamic variable to predict ET-1 and ANP expression in the remote area. We conclude that ET-1, ANP, and IGF-1 are expressed in different patterns in the infarcted heart in relation to time, functional regions, cellular distribution, and mechanical load.
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Affiliation(s)
- J P Loennechen
- Department of Physiology and Biomedical Engineering, Norwegian University of Science and Technology, N-7489 Trondheim, Norway
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30
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Lauth M, Cattaruzza M, Hecker M. ACE inhibitor and AT1 antagonist blockade of deformation-induced gene expression in the rabbit jugular vein through B2 receptor activation. Arterioscler Thromb Vasc Biol 2001; 21:61-6. [PMID: 11145934 DOI: 10.1161/01.atv.21.1.61] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Deformation-induced endothelin-1 synthesis in endothelial cells may contribute to the intimal hyperplasia of venous bypass grafts. ACE inhibitors and angiotensin II type 1 (AT(1)) receptor antagonists are capable of reducing vein graft disease. Therefore, the effects of these drugs on endothelial preproendothelin-1 (ppET-1) and smooth muscle endothelin B receptor (ET(B)-R) expression were investigated in isolated perfused segments of the rabbit jugular vein. Pretreatment with ramiprilat (0.3 micromol/L) or irbesartan (0.01 to 1 micromol/L) had no effect on basal ppET-1 or ET(B)-R expression but markedly attenuated the deformation-induced expression of these gene products, and these effects were reversed by the B(2) receptor antagonist icatibant (Hoe 140) and by the NO synthase inhibitor N(G)-nitro-L-arginine. Candesartan (1 micromol/L) mimicked the inhibitory effect of irbesartan. Moreover, reporter gene analysis with a rat ppET-1 promoter-luciferase construct transiently transfected into porcine aortic cultured endothelial cells revealed that the inhibitory effect of both ramiprilat and irbesartan on deformation-induced ppET-1 expression is species independent and mediated at the level of transcription. In addition, RT-PCR analysis detected only AT(1) receptor expression in the endothelium-intact rabbit jugular vein, and neither irbesartan nor ramiprilat affected endothelial NO synthase expression. Thus, ACE inhibitors and AT(1) receptor antagonists are capable of suppressing deformation-induced gene expression in the vessel wall in both an autocrine (ppET-1) and a paracrine (ET(B)-R) manner via a common mechanism of action that constitutes a B(2) receptor-mediated increase in endothelial NO release.
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MESH Headings
- Angiotensin Receptor Antagonists
- Angiotensin-Converting Enzyme Inhibitors/pharmacology
- Animals
- Biphenyl Compounds/pharmacology
- Cells, Cultured
- Endothelin-1/biosynthesis
- Endothelin-1/genetics
- Endothelin-1/metabolism
- Gene Expression Regulation/drug effects
- Glyceraldehyde-3-Phosphate Dehydrogenases/pharmacology
- In Vitro Techniques
- Irbesartan
- Male
- Peptide Fragments/pharmacology
- Perfusion
- Pressure
- RNA, Messenger/biosynthesis
- Rabbits
- Ramipril/analogs & derivatives
- Ramipril/pharmacology
- Receptor, Angiotensin, Type 1
- Receptor, Angiotensin, Type 2
- Receptor, Bradykinin B2
- Receptor, Endothelin B
- Receptors, Angiotensin/metabolism
- Receptors, Bradykinin/metabolism
- Receptors, Endothelin/biosynthesis
- Receptors, Endothelin/genetics
- Receptors, Endothelin/metabolism
- Swine
- Tetrazoles/pharmacology
- Transfection
- Vasoconstriction/drug effects
- Vasoconstriction/genetics
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Affiliation(s)
- M Lauth
- Department of Cardiovascular Physiology, University of Göttingen, Göttingen, Germany
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31
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Matrougui K, Lévy BI, Henrion D. Tissue angiotensin II and endothelin-1 modulate differently the response to flow in mesenteric resistance arteries of normotensive and spontaneously hypertensive rats. Br J Pharmacol 2000; 130:521-6. [PMID: 10821779 PMCID: PMC1572118 DOI: 10.1038/sj.bjp.0703371] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
In resistance arteries pressure-induced (myogenic) tone (MT) and flow (shear stress)-induced dilation (FD) are potent determinant of vascular resistance. We investigated the role of angiotensin II and endothelin-1 in FD and MT in resistance arteries and their potential change in hypertension. Flow - diameter - pressure relationship was established in situ, under anaesthesia, in two daughter branches of a mesenteric resistance artery (180 microM, n=7 per group) from spontaneously hypertensive (SHR) or normotensive (WKY) rats. One artery was ligated distally, so that it was submitted to pressure only, while the other was submitted to pressure and flow. Drugs were added to the preparation and external diameter, pressure and flow measured continuously. External diameter (with flow) ranged from 150+/-3 to 191+/-7 microM in WKY (n=28) rats and from 168+/-6 to 186+/-6 microM in SHR (n=28). Flow induced a dilation of the non-ligated arteries which was lower in SHR (13+/-5 - 31+/-4 microM vs WKY: 5+/-5 - 44+/-4 microM). In the ligated artery, the diameter did not significantly change, due to MT. In the vessels submitted to flow angiotensin converting enzyme inhibition (perindopril, 10 micromol L(-1)) increased the diameter in SHR (+11+/-2 microM) significantly more than in WKY (+2+/-1 microM). Angiotensin type 1 receptor (AT(1)R) blockade (losartan, 10 micromol L(-1)) increased the diameter in the vessels with flow in SHR only (+6+/-1 microM). Angiotensin type 2 receptor (AT(2)R) blockade (PD 123319, 1 micromol L(-1)) decreased arterial diameter in WKY only (9+/-2). Endothelin-1 type A receptor (ET(A)R) blockade (LU135252, 0.1 micromol L(-1)) increased the diameter only in SHR in the artery submitted to flow (by 6+/-1 microM). Thus FD was counteracted by a flow-dependent AT(1) and ET(A) receptors-activation in SHR whereas in WKY FD AT(2)-dependent dilation is involved.
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Affiliation(s)
- K Matrougui
- Institut National de la Santé et de la Recherche Médicale (INSERM) U 541, IFR 6, Université Paris VII, 41 Bd de la Chapelle, 75475 Paris, cedex 10, France
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32
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Ressler B, Lee RT, Randell SH, Drazen JM, Kamm RD. Molecular responses of rat tracheal epithelial cells to transmembrane pressure. Am J Physiol Lung Cell Mol Physiol 2000; 278:L1264-72. [PMID: 10835333 DOI: 10.1152/ajplung.2000.278.6.l1264] [Citation(s) in RCA: 83] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Smooth muscle constriction in asthma causes the airway to buckle into a rosette pattern, folding the epithelium into deep crevasses. The epithelial cells in these folds are pushed up against each other and thereby experience compressive stresses. To study the epithelial cell response to compressive stress, we subjected primary cultures of rat tracheal epithelial cells to constant elevated pressures on their apical surface (i.e., a transmembrane pressure) and examined changes in the expression of genes that are important for extracellular matrix production and maintenance of smooth muscle activation. Northern blot analysis of RNA extracted from cells subjected to transmembrane pressure showed induction of early growth response-1 (Egr-1), endothelin-1, and transforming growth factor-beta1 in a pressure-dependent and time-dependent manner. Increases in Egr-1 protein were detected by immunohistochemistry. Our results demonstrate that airway epithelial cells respond rapidly to compressive stresses. Potential transduction mechanisms of transmembrane pressure were also investigated.
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Affiliation(s)
- B Ressler
- Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge 02139, USA
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33
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Cattaruzza M, Dimigen C, Ehrenreich H, Hecker M. Stretch-induced endothelin B receptor-mediated apoptosis in vascular smooth muscle cells. FASEB J 2000; 14:991-8. [PMID: 10783154 DOI: 10.1096/fasebj.14.7.991] [Citation(s) in RCA: 77] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Growing evidence suggests that a pressure-induced increase in the synthesis of endothelin (ET-1) is involved in arterial remodeling and, as a consequence, in the manifestation of chronic hypertension. To study potential stretch-induced changes in gene expression and their functional consequences, we have cultured rat aortic smooth muscle cells (raSMC) and porcine aortic endothelial cells (PAEC) on flexible elastomer membranes. The cells were periodically stretched (up to 20% elongation, 0.5 Hz, 6 h) and the expression of prepro-ET-1 and that of the endothelin A and B receptors (ET(A)-R and ET(B)-R) were analyzed by semi-quantitative RT-PCR analysis and ELISA (ET-1). In contrast to PAEC where ET-1 synthesis was up-regulated up to eightfold on exposure to cyclic stretch, ET-1 synthesis in raSMC was decreased by more than 80% under these conditions. ET(A) R -mRNA expression in stretched raSMC declined to 50% whereas ET(B) R -mRNA levels were increased up to 10-fold. One functional consequence of this apparent shift in receptor abundance was an apoptosis-promoting action of exogenous ET-1 (10 nM), as judged by the appearance of subdiploid peaks during FACS analysis, caspase-3 activation and chromatin condensation. This ET-1-induced apoptosis appeared to be ET(B)-R mediated, as it was completely suppressed by the ET(B)-R antagonist BQ 788 but not by the ET(A)-R antagonist BQ 123. Moreover, raSMC derived from homozygous spotting lethal rats, which lack a functional ET(B)-R, showed no signs of apoptosis after exposure to cyclic strain and exogenous ET-1. These findings suggest a central role for the endothelin system in the onset of hypertension-induced remodeling in conduit arteries, which may proceed via an initial stretch-induced apoptosis of the smooth muscle cells.
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MESH Headings
- Animals
- Apoptosis/physiology
- Base Sequence
- Cells, Cultured
- DNA Primers
- Endothelin-1/genetics
- Endothelin-1/metabolism
- Gene Expression Regulation
- Male
- Muscle, Smooth, Vascular/cytology
- Muscle, Smooth, Vascular/metabolism
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- Rats
- Rats, Wistar
- Receptor, Endothelin B
- Receptors, Endothelin/genetics
- Receptors, Endothelin/physiology
- Reverse Transcriptase Polymerase Chain Reaction
- Swine
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Affiliation(s)
- M Cattaruzza
- Department of Cardiovascular Physiology, University of Goettingen. Max-Planck-Institute for Experimental Medicine and Departments of Neurology and Psychiatry, University of Goettingen, Germany
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34
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Lauth M, Berger MM, Cattaruzza M, Hecker M. Elevated perfusion pressure upregulates endothelin-1 and endothelin B receptor expression in the rabbit carotid artery. Hypertension 2000; 35:648-54. [PMID: 10679512 DOI: 10.1161/01.hyp.35.2.648] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
To investigate the hypothesis that high blood pressure activates the endothelin system in the vessel wall, isolated segments of the rabbit carotid artery were subjected to different levels of perfusion pressure. Both preproendothelin-1 (ppET-1) mRNA abundance and intravascular ET-1 peptide content were strongly upregulated on raising the intraluminal pressure from 90 to 160 mm Hg for 3 to 12 hours, and this increase in ppET-1 mRNA occurred predominantly in the endothelial cells. Endothelin-converting enzyme-1 and endothelin A receptor (ET(A)-R) expression were pressure-insensitive, whereas that of the ET(B)-R in the smooth muscle cells was also significantly enhanced. Both the pressure-induced increase in ppET-1 and ET(B)-R expression required RNA synthesis because they were abolished by actinomycin D. The nuclear signaling mechanisms involved therein, however, appeared to be different. Thus, the pressure-induced expression of ppET-1 and activation of CCAAT-enhancer binding proteins beta and delta were blocked by the tyrosine kinase inhibitor herbimycin A, whereas ET(B)-R expression and the nuclear translocation of activator protein-1 were abolished by the protein kinase C inhibitor Ro 31-8220. One consequence of these presumably deformation-induced changes in gene expression was an increased rate of apoptosis of the smooth muscle cells in the media that if transferable to the situation in human blood vessels may contribute to hypertension-induced arterial remodeling.
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Affiliation(s)
- M Lauth
- Department of Cardiovascular Physiology, University of Goettingen, Germany
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35
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Morrison B, Eberwine JH, Meaney DF, McIntosh TK. Traumatic injury induces differential expression of cell death genes in organotypic brain slice cultures determined by complementary DNA array hybridization. Neuroscience 2000; 96:131-9. [PMID: 10683418 DOI: 10.1016/s0306-4522(99)00537-0] [Citation(s) in RCA: 67] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
The expression of a large panel of selected genes hypothesized to play a central role in post-traumatic cell death was shown to be differentially altered in response to a precisely controlled, mechanical injury applied to an organotypic slice culture of the rat brain. Within 48 h of injury, the expression of nerve growth factor messenger RNA was significantly increased whereas the levels of bcl-2, alpha-subunit of calcium/calmodulin-dependent protein kinase II, cAMP response element binding protein, 65,000 mol. wt isoform of glutamate decarboxylase, 1beta isoform of protein kinase C, and ubiquitin messenger RNA were significantly decreased. Because the expression levels of a number of other messenger RNAs such as the neuron-specific amyloid precursor protein, beta(2) microglobulin, bax, bcl(xl), brain-derived neurotrophic factor, cyclooxygenase-2, interleukin-1beta, interleukin-6, tumor necrosis factor-alpha, receptor tyrosine kinase A, and receptor tyrosine kinase B were unaffected, these selective changes may represent components of an active and directed response of the brain initiated by mechanical trauma. Interpretation of these co-ordinated alterations suggests that mechanical injury to the central nervous system may lead to disruption of calcium homeostasis resulting in altered gene expression, an impairment of intracellular cascades responsible for trophic factor signaling, and initiation of apoptosis via multiple pathways. An understanding of these transcriptional changes may contribute to the development of novel therapeutic strategies to enhance beneficial and blunt detrimental, endogenous, post-injury response mechanisms.
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Affiliation(s)
- B Morrison
- Department of Bioengineering, University of Pennsylvania, Philadelphia 19104, USA
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36
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Lauth M, Berger MM, Cattaruzza M, Hecker M. Pressure-induced upregulation of preproendothelin-1 and endothelin B receptor expression in rabbit jugular vein in situ : implications for vein graft failure? Arterioscler Thromb Vasc Biol 2000; 20:96-103. [PMID: 10634805 DOI: 10.1161/01.atv.20.1.96] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Upregulation of endothelin-1 (ET-1) synthesis in venous bypass grafts in response to arterial levels of blood pressure may play a major role in graft failure. To investigate this hypothesis, isolated segments of the rabbit jugular vein were perfused at physiological (0 to 5 mm Hg) and nonphysiological (20 mm Hg) levels of intraluminal pressure. As judged by reverse transcription-polymerase chain reaction analysis (mRNA level), neither endothelin-converting enzyme nor endothelin A receptor expression appeared to be pressure sensitive. In contrast, there was a profound and time-dependent increase in endothelial prepro-ET-1 mRNA and intravascular ET-1 abundance (by ELISA) as well as in smooth muscle endothelin B receptor mRNA and functional protein (by superfusion bioassay) on raising the perfusion pressure from 5 to 20 mm Hg, but not from 0 to 5 mm Hg, for up to 12 hours. Video microscopy analysis revealed that the segments were distended by 75% at 5 mm Hg and near maximally at 20 mm Hg compared with the resting diameter at 0 to 1 mm Hg. Treatment of the segments with actinomycin D (1 micromol/L), the specific protein kinase C inhibitor, Ro 31-8220 (0.1 micromol/L), or the c-Src family-specific tyrosine kinase inhibitor, herbimycin A (0.1 micromol/L), demonstrated that the pressure-induced expression of these gene products occurs at the level of transcription and requires activation of protein kinase C, but not c-Src. In venous bypass grafts such deformation-induced changes in gene expression may contribute not only to acute graft failure through ET-1-induced vasospasm but also to endothelin A receptor- and/or endothelin B receptor-mediated smooth muscle cell hyperplasia and graft occlusion.
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Affiliation(s)
- M Lauth
- Department of Cardiovascular Physiology, University of Goettingen, Goettingen, Germany
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37
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38
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Wung BS, Cheng JJ, Chao YJ, Hsieh HJ, Wang DL. Modulation of Ras/Raf/extracellular signal-regulated kinase pathway by reactive oxygen species is involved in cyclic strain-induced early growth response-1 gene expression in endothelial cells. Circ Res 1999; 84:804-12. [PMID: 10205148 DOI: 10.1161/01.res.84.7.804] [Citation(s) in RCA: 89] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Endothelial cells (ECs) exposed to cyclic strain induce gene expression. To elucidate the signaling mechanisms involved, we studied the effects of cyclic strain on ECs by using early growth response-1 (Egr-1) as a target gene. Cyclic strain induced a transient increase of Egr-1 mRNA levels that resulted in an increase of binding of nuclear proteins to the Egr-1 binding sequences in the platelet-derived growth factor-A promoter region. ECs subjected to strain enhanced Egr-1 transcription as revealed by promoter activities. Catalase pretreatment inhibited this induction. ECs, transfected with a dominant positive mutant of Ras (RasL61), increased Egr-1 promoter activities. In contrast, transfection with a dominant negative mutant of Ras (RasN17) attenuated this strain inducibility. ECs transfected with a dominant negative mutant of Raf-1 (Raf301) or the catalytically inactive mutant of extracellular signal-regulated kinase (ERK)-2 (mERK2) diminished strain-induced promoter activities. However, little effect on strain inducibility was observed in ECs transfected with a dominant negative mutant of Rac (RacN17) or a catalytically inactive mutant of JNK (JNK[K-R]). Consistently, strain-induced Egr-1 expression was inhibited after ECs were treated with a specific inhibitor (PD98059) to mitogen-activated protein kinase kinase. Moreover, strain to ECs induced mitogen-activated protein kinase/ERK activity. The activation of the ERK pathway was further substantiated by an increase of strain-induced transcriptional activity of Elk1, an ERK substrate. This strain-induced ERK activity was attenuated after ECs were treated with N-acetylcysteine or catalase. Consequently, this Egr-1 gene induction was abolished after ECs were treated with N-acetylcysteine or catalase. Deletion analyses of the promoter region (-698 bp) indicated that cyclic strain and H2O2 shared a common serum response element. Our data clearly indicate that cyclic strain-induced Egr-1 expression is mediated mainly via the Ras/Raf-1/ERK pathway and that strain-induced reactive oxygen species can modulate Egr-1 expression at least partially via this signaling pathway.
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Affiliation(s)
- B S Wung
- Cardiovascular Division, Institute of Biomedical Sciences, Academia Sinica, and Department of Chemical Engineering, National Taiwan University, Taipei, Taiwan, ROC
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39
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Villard E, Alonso A, Agrapart M, Challah M, Soubrier F. Induction of angiotensin I-converting enzyme transcription by a protein kinase C-dependent mechanism in human endothelial cells. J Biol Chem 1998; 273:25191-7. [PMID: 9737980 DOI: 10.1074/jbc.273.39.25191] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Angiotensin I-converting enzyme (ACE) has been implicated in various cardiovascular diseases; however, little is known about the ACE gene regulation in endothelial cells. We have investigated the effect of the protein kinase C activator phorbol 12-myristate 13-acetate (PMA) on ACE activity and gene expression in human umbilical vein endothelial cells (HUVEC). Our results showed a 3- and 5-fold increase in ACE activity in the medium and in the cells, respectively, after 24-h stimulation by PMA. We also observed an increase in the cellular ACE mRNA content starting after 6 h and reaching a 10-fold increase at 24 h in response to 100 ng/ml PMA as measured by ribonuclease protection assay. This effect was mediated by an increased transcription of the ACE gene as demonstrated by nuclear run-on experiments and nearly abolished by the specific PKC inhibitor GF 109203X. Our results indicate that PMA-activated PKC strongly increases ACE mRNA level and ACE gene transcription in HUVEC, an effect associated with an increased ACE secretion. A role for early growth response factor-1 (Egr-1) as a factor regulating ACE gene expression is suggested by both the presence of an Egr-1-responsive element in the proximal portion of the ACE promoter and the kinetics of the Egr-1 mRNA increase in HUVEC treated with PMA.
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Affiliation(s)
- E Villard
- INSERM Unité 358, Hôpital Saint-Louis, 1 avenue Claude Vellefaux, 75475 Paris Cedex 10, France
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40
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Abstract
Shear stress and the endothelium. Vascular endothelial cells (ECs) in vivo are influenced by two distinct hemodynamic forces: cyclical strain due to vessel wall distention by transmural pressure, and shear stress, the frictional force generated by blood flow. Shear stress acts at the apical cell surface to deform cells in the direction of blood flow; wall distention tends to deform cells in all directions. The shear stress response differs, at least partly, from the cyclical strain response, suggesting that cytoskeletal strain alone cannot explain it. Acute shear stress in vitro elicits rapid cytoskeletal remodeling and activates signaling cascades in ECs, with the consequent acute release of nitric oxide and prostacyclin; activation of transcription factors nuclear factor (NF)kappaB, c-fos, c-jun and SP-1; and transcriptional activation of genes, including ICAM-1, MCP-1, tissue factor, platelet-derived growth factor-B (PDGF-B), transforming growth factor (TGF)-beta1, cyclooxygenase-II, and endothelial nitric oxide synthase (eNOS). This response thus shares similarities with EC responses to inflammatory cytokines. In contrast, ECs adapt to chronic shear stress by structural remodeling and flattening to minimize shear stress. Such cells become very adherent to their substratum and show evidence of differentiation. Increased adhesion following chronic shear stress has been exploited to generate vascular grafts with confluent EC monolayers, retained after implantation in vivo, thus overcoming a major obstacle to endothelialization of vascular prostheses.
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Affiliation(s)
- B J Ballermann
- Department of Medicine, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, USA.
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41
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Bouaziz A, de Ficquelmont-Loïzos MM, Richert A, Caprani A. Direct physical factors and PGI2 and TXA2 secretions by a human endothelial cell line: in vitro investigation of pressure and shear stress applied independently or in synergy. Thromb Res 1998; 90:279-89. [PMID: 9700858 DOI: 10.1016/s0049-3848(98)00059-0] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
The direct effect of two types of mechanical stress was measured through the prostacyclin (PGI2) and thromboxane A2 (TXA2) secretions by a confluent monolayer of cells from the EA.hy926 line. Eight values of constant pressure were applied in the gas phase above the culture medium, around atmospheric pressure taken as a control (0 mm Hg), from -500 to +760 mm Hg. Three amplitudes of sinewave modulated pressure (+/- 40; +/- 80; +/- 160 mm Hg) were explored at a frequency of 1 Hz. Modulated pressure (+/- 40 mm Hg) was also applied synergetically to a shear stress generated under steady state conditions by a rectilinear laminar motion of the medium. The cells remained adherent and exhibited unchanged morphology and viability. Constant pressure or depressure increased both PGI2 and TXA2 release but to an extent depending on the pressure value. Under pressure, the PGI2/TXA2 ratio was unchanged, but was higher under depressure, compared to the control. Pressure modulation strongly stimulated the secretion of PGI2 but had no effect on TXA2. Modulation strongly increased the PGI2/TXA2 ratio to a similar extent for the three amplitudes. Pressure-shear synergy enhanced secretion of PGI2 markedly more than shear stress alone, but the level reached was similar to the one induced by pressure modulation. No cumulative effect on the secretion of PGI2 was observed, whereas TXA2 synthesis undergoes a more than cumulative effect. The PGI2/TXA2 ratio remained unchanged under shear alone or under combined shear-pressure modulation but was higher with the modulated pressure alone. These results demonstrate that pressure has an outstanding effect on secretion that may be origin to local disturbances of the vascular system, thus inducing pathologies such as thrombosis or atherosclerosis.
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Affiliation(s)
- A Bouaziz
- Laboratoire de Biorhéologie et d'Hydrodynamique Physico-chimique (LBHP), ESA 7057 CNRS, Université Denis-Diderot, Paris, France
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42
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Ziegler T, Bouzourène K, Harrison VJ, Brunner HR, Hayoz D. Influence of oscillatory and unidirectional flow environments on the expression of endothelin and nitric oxide synthase in cultured endothelial cells. Arterioscler Thromb Vasc Biol 1998; 18:686-92. [PMID: 9598825 DOI: 10.1161/01.atv.18.5.686] [Citation(s) in RCA: 222] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
In vivo, endothelial cells (ECs) are subjected to a complex mechanical environment composed of shear stress, pressure, and circumferential stretch. The aim of this study was to subject bovine aortic ECs to a pulsatile pressure oscillating from 70 to 130 mm Hg (mean of 100 mm Hg) in combination with pulsatile shear stresses from 0.1 to 6 dyne/cm2 (1 dyne/cm2=0.1 N/m2) with or without a cyclic circumferential stretch of 4% for 1, 4, and 24 hours. The effect of highly reversing oscillatory shear stress (range -3 to +3 dyne/cm2, mean of 0.3 dyne/cm2) typical of regions prone to the development of atherosclerotic plaques was also studied at 4 and 24 hours. Endothelin-1 (ET-1) and endothelial constitutive nitric oxide synthase (ecNOS) mRNA expression was time and mechanical force dependent. ET-1 mRNA was maximal at 4 hours and decreased to less than static culture expression at 24 hours, whereas ecNOS mRNA increased over time. Pressure combined with low shear stress upregulated ET-1 and ecNOS mRNA compared with static control. Additional increase in expression for both genes was observed under a combination of higher shear stress and pressure. A cyclic circumferential stretch of 4% did not induce a further increase in ET-1 and ecNOS mRNA at either low or high shear stress. Oscillatory shear stress with pressure induced a higher expression of ET-1 mRNA but lower expression of ecNOS mRNA compared with unidirectional shear stress and pressure. We have shown that the combination of pressure and oscillatory shear stress can downregulate ecNOS levels, as well as upregulate transient expression of ET-1, compared with unidirectional shear stress. These results provide a new insight into the exact role of mechanical forces in endothelial dysfunction in regions prone to the development of atherosclerosis.
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Affiliation(s)
- T Ziegler
- Division of Hypertension and Vascular Medicine, Lausanne University Hospital, Switzerland.
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43
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Chien S, Li S, Shyy YJ. Effects of mechanical forces on signal transduction and gene expression in endothelial cells. Hypertension 1998; 31:162-9. [PMID: 9453297 DOI: 10.1161/01.hyp.31.1.162] [Citation(s) in RCA: 373] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Fluid shear stress and circumferential stretch play important roles in maintaining the homeostasis of the blood vessel, and they can also be pathophysiological factors in cardiovascular diseases such as atherosclerosis and hypertension. The uses of flow channels and stretch devices as in vitro models have helped to elucidate the mechanisms of signal transduction and gene expression in cultured endothelial cells in response to shear stress, which is a function of blood flow and vascular geometry, or mechanical strain, which is a function of transmural pressure and the mechanical properties and geometry of the vessel. Shear stress has been found to increase the activities of a number of kinases to modulate the phosphorylation of many signaling proteins in endothelial cells, eg, the proteins in focal adhesion sites and the proteins in the mitogen-activated protein kinase pathways. Downstream to such signaling cascades, multiple transcription factors such as AP-1, NF-kappaB, Sp-1, and Egr-1 are activated. The actions of these transcription factors on the corresponding cis-elements result in the induction of genes encoding for vasoactivators, adhesion molecules, monocyte chemoattractants, and growth factors in endothelial cells, thus modulating vascular structure and function. Some of the effects of mechanical strain on endothelial cells are similar to those by shear stress, eg, the signaling pathways and the genes activated, but there are differences, eg, the time course of the responses. Studies on the effects of mechanical forces on signal transduction and gene expression provide insights into the molecular mechanisms by which hemodynamic factors regulate vascular physiology, and pathophysiology.
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Affiliation(s)
- S Chien
- Department of Bioengineering and Institute for Biomedical Engineering, University of California, San Diego, La Jolla 92093-0412, USA.
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44
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Cheng JJ, Wung BS, Chao YJ, Wang DL. Cyclic strain-induced reactive oxygen species involved in ICAM-1 gene induction in endothelial cells. Hypertension 1998; 31:125-30. [PMID: 9449403 DOI: 10.1161/01.hyp.31.1.125] [Citation(s) in RCA: 72] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Vascular endothelial cells (ECs) are constantly subjected to pressure-induced strain. We have previously demonstrated that strain can induce intercellular adhesion molecule-1 (ICAM-1) expression in ECs. The molecular mechanisms of gene induction by strain, however, remain unclear. Recent evidence suggests that intracellular reactive oxygen species (ROS) may act as second messengers. The potential role of ROS in strain-induced ICAM-1 expression was examined. ECs grown on a flexible membrane base were deformed with various sinusoidal negative pressures to produce an average strain of 12%. Cyclic strain induced an increase in intracellular ROS measured by fluorescent intensity of dichlorofluorescein formed after peroxidation. Maximal levels of ROS were seen after 30 minutes. Levels subsequently decreased but remained elevated compared with unstrained groups. Concomitantly, a sustained increase of H2O2 decomposition activity was observed in strained ECs. Both ROS and H2O2 decomposition activity returned to basal levels after removal of the strain. ECs treated with an antioxidant (N-acetylcysteine or catalase) inhibited strain-induced ROS generation and ICAM-1 mRNA levels followed by decreased ICAM-1 expression on EC surfaces. This inhibition may account for the reduced monocytic cell adhesion in antioxidant-treated ECs but not in strained controls. Our findings indicate that cyclic strain-induced monocyte adhesion to ECs is mediated, at least in part, by an increase of ICAM-1 gene expression via the elevation of ROS levels in strained ECs. Our results support the importance of intracellular ROS in the modulation of hemodynamic force-induced endothelial responses.
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Affiliation(s)
- J J Cheng
- Graduate Institute of Life Sciences, National Defense Medical Center, Taipei, Taiwan, ROC
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45
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Wung BS, Cheng JJ, Hsieh HJ, Shyy YJ, Wang DL. Cyclic strain-induced monocyte chemotactic protein-1 gene expression in endothelial cells involves reactive oxygen species activation of activator protein 1. Circ Res 1997; 81:1-7. [PMID: 9201021 DOI: 10.1161/01.res.81.1.1] [Citation(s) in RCA: 174] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Endothelial cells (ECs) are constantly exposed to blood pressure-induced mechanical strain. We have previously demonstrated that cyclic strain can induce gene expression of monocyte chemotactic protein-1 (MCP-1). The molecular mechanisms of gene induction by strain, however, remain unclear. Recent evidence indicates that intracellular reactive oxygen species (ROS) can act as a second messenger for signal transduction and thus affect gene expression. The potential role of ROS in strain-induced MCP-1 expression was investigated. ECs under cyclic strain induced a sustained elevated production of intracellular superoxide. ECs under strain or pretreated with either H2O2 or xanthine oxidase/hypoxanthine induced MCP-1 expression. Strain- or oxidant-induced MCP-1 mRNA levels could be inhibited by treating ECs with catalase or antioxidant N-acetyl-cysteine (NAC). Functional analysis of MCP-1 promoter and site-specific mutations indicates that the proximal tissue plasminogen activator-responsive element (TRE) in the -60-bp promoter region is sufficient for strain or H2O2 inducibility. Electrophoretic mobility shift assays demonstrated an increase of nuclear proteins binding to TRE sequences from ECs subsequent to strain or H2O2 treatment. NAC or catalase pretreatment of ECs inhibited the strain- or H2O2-induced AP-1 binding. These results clearly indicate that cyclic strain inducibility of MCP-1 in ECs uses the interaction of AP-1 proteins with TRE sites via the elevation of intracellular ROS levels in strained ECs. These findings emphasize the importance of intracellular ROS in the modulation of hemodynamic force-induced gene expression in vascular ECs.
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Affiliation(s)
- B S Wung
- Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan, ROC
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Abstract
Endothelin-1 (ET-1) is a 21-amino acid peptide that potently modulates renal function. ET-1 is produced by, and binds to, most renal cell types. ET-1 exerts a wide range of biologic effects in the kidney, including constriction of most renal vessels, mesangial cell contraction, inhibition of sodium and water reabsorption by the nephron, enhancement of glomerular cell proliferation, and stimulation of extracellular matrix accumulation. ET-1 functions primarily as an autocrine or paracrine factor; its renal effects must be viewed in the context of its local production and actions. This is particularly important when comparing ET-1 biology in the nephron, where it promotes relative hypotension through increased salt and water excretion, with ET-1 effects in the vasculature, where it promotes relative hypertension through vasoconstriction. Numerous studies indicate that ET-1 is involved in the pathogenesis of a broad spectrum of renal diseases. These include those characterized by excessive renal vascular resistance, such as ischemic renal failure, cyclosporine (CyA) nephrotoxicity, radiocontrast nephropathy, endotoxemia, rhabdomyolysis, acute liver rejection, and others. ET-1 appears to play a role in cell proliferation in the setting of inflammatory glomerulonephritides. The peptide also may mediate, at least in part, excessive extracellular matrix accumulation and fibrosis occurring in chronic renal failure, diabetes mellitus, and other disorders. Deranged ET-1 production in the nephron may cause inappropriate sodium and water retention, thereby contributing to the development and/or maintenance of hypertension. Finally, impaired renal clearance of ET-1 may cause hypertension in patients with end-stage renal disease. Many ET-1 antagonists have been developed; however, their clinical usefulness has not yet been determined. Despite this, these agents hold great promise for the treatment of renal diseases; it is hoped that the next decade will witness their introduction into clinical practice.
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Affiliation(s)
- D E Kohan
- Department of Medicine, Veterans Affairs Medical Center, Salt Lake City 84132, USA
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Cheng JJ, Wung BS, Chao YJ, Wang DL. Cyclic strain enhances adhesion of monocytes to endothelial cells by increasing intercellular adhesion molecule-1 expression. Hypertension 1996; 28:386-91. [PMID: 8794821 DOI: 10.1161/01.hyp.28.3.386] [Citation(s) in RCA: 71] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Since endothelial cells are constantly subjected to pressure-induced strain, we examined how cyclic strain affects the expression of intercellular adhesion molecule-1 (ICAM-1). Endothelial cells grown on a flexible membrane base were deformed by different sinusoidal negative pressures (-10, -15, or -20 kPa) to produce an average strain of 9%, 11%, and 12%, respectively, for various times. The release of the soluble form of ICAM-1 from strained endothelial cells increased in a time- and strain-dependent manner. Using flow cytometric analysis, we showed the induction of ICAM-1 expression on the endothelial cell surface to depend on both time and the amount of strain. Northern blot analysis revealed a sustained, approximately 1.8-fold increase in ICAM-1 mRNA levels in 11% strained cells. Strain-induced expression of ICAM-1 correlated with a strain-dependent increase in adhesion of monocytic cells to strained cells. This increase in monocytic cell adhesion could be partially inhibited by pretreatment of strained cells with antibody to ICAM-1. These results indicate that mechanical strain can stimulate the expression of ICAM-1 by endothelial cells and thus contribute to the increased adhesion of monocytes to strained cells. Such strain-induced expression of ICAM-1 may contribute to the trapping of monocytes on local vascular walls where strain is high and to the initiation of atherogenesis, thus providing a possible link between hypertension and atherogenesis.
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Affiliation(s)
- J J Cheng
- Cardiovascular Division, Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan, ROC
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Wang DL, Wung BS, Shyy YJ, Lin CF, Chao YJ, Usami S, Chien S. Mechanical strain induces monocyte chemotactic protein-1 gene expression in endothelial cells. Effects of mechanical strain on monocyte adhesion to endothelial cells. Circ Res 1995; 77:294-302. [PMID: 7614716 DOI: 10.1161/01.res.77.2.294] [Citation(s) in RCA: 82] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Monocyte chemotactic protein-1 (MCP-1), a potent monocyte chemoattractant secreted by endothelial cells (ECs), is believed to play a key role in the early events of atherogenesis. Since vascular ECs are constantly subjected to mechanical stresses, we examined how cyclic strain affects the expression of the MCP-1 gene in human ECs grown on a flexible membrane base deformed by sinusoidal negative pressure (peak level, -16 kPa at 60 cycles per minute). Northern blot analysis demonstrated that the MCP-1 mRNA levels in ECs subjected to strain for 1, 5, or 24 hours were double those in control ECs (P < .05). This strain-induced increase was mainly serum independent, and MCP-1 mRNA level returned to its control basal level 3 hours after release of strain. Culture media from strained ECs contained approximately twice the MCP-1 concentration and more than twice the monocyte chemotactic activity of media from control ECs (P < .05). Pretreatment of collected media with anti-MCP-1 antibody suppressed such activity. Monocyte adhesion to ECs subjected to strain for 12 hours was 1.8-fold greater than adhesion to unstrained control ECs (P < .05). A protein kinase C inhibitor, calphostin C, abolished the strain-induced MCP-1 gene expression. In addition, cAMP- or cGMP-dependent protein kinase inhibitors (KT5720 and KT5823, respectively) partially inhibited such expression. Pretreatment with EGTA or the intracellular Ca2+ chelator BAPTA/AM strongly suppressed the strain-induced MCP-1 mRNA. Verapamil, a Ca2+ channel blocker, greatly reduced MCP-1 mRNA levels in both strained and unstrained ECs.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- D L Wang
- Cardiovascular Division, Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan, ROC
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