1
|
Dang Z, Li H, Xue S, Shao B, Ning Y, Su G, Zhang F, Yu W, Leng S. Histone deacetylase 9-mediated phenotypic transformation of vascular smooth muscle cells is a potential target for treating aortic aneurysm/dissection. Biomed Pharmacother 2024; 173:116396. [PMID: 38460370 DOI: 10.1016/j.biopha.2024.116396] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2023] [Revised: 02/29/2024] [Accepted: 03/06/2024] [Indexed: 03/11/2024] Open
Abstract
Aortic aneurysm/dissection (AAD) is a serious cardiovascular condition characterized by rapid onset and high mortality rates. Currently, no effective drug treatment options are known for AAD. AAD pathogenesis is associated with the phenotypic transformation and abnormal proliferation of vascular smooth muscle cells (VSMCs). However, endogenous factors that contribute to AAD progression remain unclear. We aimed to investigate the role of histone deacetylase 9 (HDAC9) in AAD pathogenesis. HDAC9 expression was considerably increased in human thoracic aortic dissection specimens. Using RNA-sequencing (RNA-seq) and chromatin immunoprecipitation, we demonstrated that HDAC9 transcriptionally inhibited the expression of superoxide dismutase 2 and insulin-like growth factor-binding protein-3, which are critically involved in various signaling pathways. Furthermore, HDAC9 triggered the transformation of VSMCs from a systolic to synthetic phenotype, increasing their proliferation and migration abilities and suppressing their apoptosis. Consistent with these results, in vivo experiments revealed that TMP195, a pharmacological inhibitor of HDAC9, suppressed the formation of the β-aminopropionitrile-induced AAD phenotype in mice. Our findings indicate that HDAC9 may be a novel endogenous risk factor that promotes the onset of AAD by mediating the phenotypic transformation of VSMCs. Therefore, HDAC9 may serve as a potential therapeutic target for drug-based AAD treatment. Furthermore, TMP195 holds potential as a therapeutic agent for AAD treatment.
Collapse
Affiliation(s)
- Zhiqiao Dang
- Department of Cardiac Surgery, Central Hospital Affiliated to Shandong First Medical University, Jinan, Shandong 250013, China
| | - Haijie Li
- Department of Cardiac Surgery, Central Hospital Affiliated to Shandong First Medical University, Jinan, Shandong 250013, China
| | - Shishan Xue
- Research Center of Translational Medicine, Central Hospital Affiliated to Shandong First Medical University, Jinan, Shandong 250013, China
| | - Baowei Shao
- Department of Cardiac Surgery, Central Hospital Affiliated to Shandong First Medical University, Jinan, Shandong 250013, China
| | - Yansong Ning
- Department of Cardiac Surgery, Central Hospital Affiliated to Shandong First Medical University, Jinan, Shandong 250013, China
| | - Guohai Su
- Research Center of Translational Medicine, Central Hospital Affiliated to Shandong First Medical University, Jinan, Shandong 250013, China
| | - Fengquan Zhang
- Department of Cardiac Surgery, Central Hospital Affiliated to Shandong First Medical University, Jinan, Shandong 250013, China.
| | - Wenqian Yu
- Department of Cardiac Surgery, Central Hospital Affiliated to Shandong First Medical University, Jinan, Shandong 250013, China; Research Center of Translational Medicine, Central Hospital Affiliated to Shandong First Medical University, Jinan, Shandong 250013, China.
| | - Shuai Leng
- Department of Cardiac Surgery, Central Hospital Affiliated to Shandong First Medical University, Jinan, Shandong 250013, China; Research Center of Translational Medicine, Central Hospital Affiliated to Shandong First Medical University, Jinan, Shandong 250013, China.
| |
Collapse
|
2
|
Cyclic-AMP Increases Nuclear Actin Monomer Which Promotes Proteasomal Degradation of RelA/p65 Leading to Anti-Inflammatory Effects. Cells 2022; 11:cells11091414. [PMID: 35563720 PMCID: PMC9101168 DOI: 10.3390/cells11091414] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2022] [Revised: 04/05/2022] [Accepted: 04/14/2022] [Indexed: 12/04/2022] Open
Abstract
The second messenger, cAMP has potent immunosuppressive and anti-inflammatory actions. These have been attributed, in part, to the ability of cAMP-induced signals to interfere with the function of the proinflammatory transcription factor Nuclear Factor-kappa B (NF-κB). However, the mechanisms underlying the modulation of NF-κB activity by cAMP remain unclear. Here we demonstrate an important role for cAMP-mediated increase in nuclear actin monomer levels in inhibiting NF-κB activity. Elevated cAMP or forced expression of a nuclear localised polymerisation defective actin mutant (NLS-ActinR62D) inhibited basal and TNFα induced mRNA levels of NF-κB-dependent genes and NF-κB-dependent reporter gene activity. Elevated cAMP or NLS-ActinR62D did not affect NF-κB nuclear translocation but did reduce total cellular and nuclear RelA/p65 levels. Preventing the cAMP-induced increase in nuclear actin monomer, either by expressing a nuclear localised active mutant of the actin polymerising protein mDIA, silencing components of the nuclear actin import complex IPO9 and CFL1 or overexpressing the nuclear export complex XPO6, rescued RelA/p65 levels and NF-κB reporter gene activity in forskolin-stimulated cells. Elevated cAMP or NLS-ActinR62D reduced the half-life of RelA/p65, which was reversed by the proteasome inhibitor MG132. Accordingly, forskolin stimulated association of RelA/p65 with ubiquitin affinity beads, indicating increased ubiquitination of RelA/p65 or associated proteins. Taken together, our data demonstrate a novel mechanism underlying the anti-inflammatory effects of cAMP and highlight the important role played by nuclear actin in the regulation of inflammation.
Collapse
|
3
|
Nguyen DDN, Zain SM, Kamarulzaman MH, Low TY, Chilian WM, Pan Y, Ting KN, Hamid A, Abdul Kadir A, Pung YF. Intracellular and exosomal microRNAome profiling of human vascular smooth muscle cells during replicative senescence. Am J Physiol Heart Circ Physiol 2021; 321:H770-H783. [PMID: 34506226 DOI: 10.1152/ajpheart.00058.2021] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Vascular aging is highly associated with cardiovascular morbidity and mortality. Although the senescence of vascular smooth muscle cells (VSMCs) has been well established as a major contributor to vascular aging, intracellular and exosomal microRNA (miRNA) signaling pathways in senescent VSMCs have not been fully elucidated. This study aimed to identify the differential expression of intracellular and exosomal miRNA in human VSMCs (hVSMCs) during replicative senescence. To achieve this aim, intracellular and exosomal miRNAs were isolated from hVSMCs and subsequently subjected to whole genome small RNA next-generation sequencing, bioinformatics analyses, and qPCR validation. Three significant findings were obtained. First, senescent hVSMC-derived exosomes tended to cluster together during replicative senescence and the molecular weight of the exosomal protein tumor susceptibility gene 101 (TSG-101) increased relative to the intracellular TSG-101, suggesting potential posttranslational modifications of exosomal TSG-101. Second, there was a significant decrease in both intracellular and exosomal hsa-miR-155-5p expression [n = 3, false discovery rate (FDR) < 0.05], potentially being a cell type-specific biomarker of hVSMCs during replicative senescence. Importantly, hsa-miR-155-5p was found to associate with cell-cycle arrest and elevated oxidative stress. Lastly, miRNAs from the intracellular pool, that is, hsa-miR-664a-3p, hsa-miR-664a-5p, hsa-miR-664b-3p, hsa-miR-4485-3p, hsa-miR-10527-5p, and hsa-miR-12136, and that from the exosomal pool, that is, hsa-miR-7704, were upregulated in hVSMCs during replicative senescence (n = 3, FDR < 0.05). Interestingly, these novel upregulated miRNAs were not functionally well annotated in hVSMCs to date. In conclusion, hVSMC-specific miRNA expression profiles during replicative senescence potentially provide valuable insights into the signaling pathways leading to vascular aging.NEW & NOTEWORTHY This is the first study on intracellular and exosomal miRNA profiling on human vascular smooth muscle cells during replicative senescence. Specific dysregulated sets of miRNAs were identified from human vascular smooth muscle cells. Hsa-miR-155-5p was significantly downregulated in both intracellular and exosomal hVSMCs, suggesting its crucial role in cellular senescence. Hsa-miR-155-5p might be the mediator in linking cellular senescence to vascular aging and atherosclerosis.
Collapse
Affiliation(s)
- Diem Duong Ngoc Nguyen
- Division of Biomedical Science, School of Pharmacy, University of Nottingham Malaysia, Selangor, Malaysia
| | - Shamsul Mohd Zain
- The Pharmacogenomics Laboratory, Department of Pharmacology, University of Malaya, Kuala Lumpur, Malaysia
| | | | - Teck Yew Low
- UKM Medical Molecular Biology Institute, Universiti Kebangsaan Malaysia, Kuala Lumpur, Malaysia
| | - William M Chilian
- Integrative Medical Sciences, Northeast Ohio Medical University, Rootstown, Ohio
| | - Yan Pan
- Division of Biomedical Science, School of Pharmacy, University of Nottingham Malaysia, Selangor, Malaysia
| | - Kang Nee Ting
- Division of Biomedical Science, School of Pharmacy, University of Nottingham Malaysia, Selangor, Malaysia
| | - Aini Hamid
- Division of Biomedical Science, School of Pharmacy, University of Nottingham Malaysia, Selangor, Malaysia
| | - Arifah Abdul Kadir
- Department of Veterinary Preclinical Sciences, Faculty of Veterinary Medicine, University Putra Malaysia, Selangor, Malaysia
| | - Yuh-Fen Pung
- Division of Biomedical Science, School of Pharmacy, University of Nottingham Malaysia, Selangor, Malaysia
| |
Collapse
|
4
|
Nguyen DND, Chilian WM, Zain SM, Daud MF, Pung YF. MicroRNA regulation of vascular smooth muscle cells and its significance in cardiovascular diseases. Can J Physiol Pharmacol 2021; 99:827-838. [PMID: 33529092 DOI: 10.1139/cjpp-2020-0581] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Cardiovascular disease (CVD) is among the leading causes of death worldwide. MicroRNAs (miRNAs), regulatory molecules that repress protein expression, have attracted considerable attention in CVD research. The vasculature plays a big role in CVD development and progression and dysregulation of vascular cells underlies the root of many vascular diseases. This review provides a brief introduction of the biogenesis of miRNAs and exosomes, followed by overview of the regulatory mechanisms of miRNAs in vascular smooth muscle cells (VSMCs) intracellular signaling during phenotypic switching, senescence, calcification, and neointimal hyperplasia. Evidence of extracellular signaling of VSMCs and other cells via exosomal and circulating miRNAs is also presented. Lastly, current drawbacks and limitations of miRNA studies in CVD research and potential ways to overcome these disadvantages are discussed in detail. In-depth understanding of VSMC regulation via miRNAs will add substantial knowledge and advance research in diagnosis, disease progression, and (or) miRNA-derived therapeutic approaches in CVD research.
Collapse
Affiliation(s)
- Duong Ngoc Diem Nguyen
- Division of Biomedical Science, School of Pharmacy, University of Nottingham Malaysia, Semenyih, 43500 Selangor, Malaysia
| | - William M Chilian
- Integrative Medical Sciences, Northeast Ohio Medical University, 4209 St. Rt. 44, P.O. Box 95, Rootstown, OH P.O. Box 95, USA
| | - Shamsul Mohd Zain
- The Pharmacogenomics Laboratory, Department of Pharmacology, University of Malaya, 50603 Kuala Lumpur, Malaysia
| | - Muhammad Fauzi Daud
- Institute of Medical Science Technology, Universiti Kuala Lumpur, Kajang, 43000 Selangor, Malaysia
| | - Yuh-Fen Pung
- Division of Biomedical Science, School of Pharmacy, University of Nottingham Malaysia, Semenyih, 43500 Selangor, Malaysia
| |
Collapse
|
5
|
Li G, Wang M, Caulk AW, Cilfone NA, Gujja S, Qin L, Chen PY, Chen Z, Yousef S, Jiao Y, He C, Jiang B, Korneva A, Bersi MR, Wang G, Liu X, Mehta S, Geirsson A, Gulcher JR, Chittenden TW, Simons M, Humphrey JD, Tellides G. Chronic mTOR activation induces a degradative smooth muscle cell phenotype. J Clin Invest 2020; 130:1233-1251. [PMID: 32039915 DOI: 10.1172/jci131048] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2019] [Accepted: 12/03/2019] [Indexed: 01/01/2023] Open
Abstract
Smooth muscle cell (SMC) proliferation has been thought to limit the progression of thoracic aortic aneurysm and dissection (TAAD) because loss of medial cells associates with advanced disease. We investigated effects of SMC proliferation in the aortic media by conditional disruption of Tsc1, which hyperactivates mTOR complex 1. Consequent SMC hyperplasia led to progressive medial degeneration and TAAD. In addition to diminished contractile and synthetic functions, fate-mapped SMCs displayed increased proteolysis, endocytosis, phagocytosis, and lysosomal clearance of extracellular matrix and apoptotic cells. SMCs acquired a limited repertoire of macrophage markers and functions via biogenesis of degradative organelles through an mTOR/β-catenin/MITF-dependent pathway, but were distinguishable from conventional macrophages by an absence of hematopoietic lineage markers and certain immune effectors even in the context of hyperlipidemia. Similar mTOR activation and induction of a degradative SMC phenotype in a model of mild TAAD due to Fbn1 mutation greatly worsened disease with near-uniform lethality. The finding of increased lysosomal markers in medial SMCs from clinical TAAD specimens with hyperplasia and matrix degradation further supports the concept that proliferation of degradative SMCs within the media causes aortic disease, thus identifying mTOR-dependent phenotypic modulation as a therapeutic target for combating TAAD.
Collapse
Affiliation(s)
- Guangxin Li
- Department of Surgery, Yale School of Medicine, New Haven, Connecticut, USA.,Department of Breast and Thyroid Surgery, Peking University Shenzhen Hospital, Shenzhen, Guangdong Province, China
| | - Mo Wang
- Department of Surgery, Yale School of Medicine, New Haven, Connecticut, USA
| | - Alexander W Caulk
- Department of Biomedical Engineering, Yale School of Engineering and Applied Science, New Haven, Connecticut, USA
| | - Nicholas A Cilfone
- Computational Statistics and Bioinformatics Group, Advanced Artificial Intelligence Research Laboratory, WuXi NextCODE, Cambridge, Massachusetts, USA
| | - Sharvari Gujja
- Computational Statistics and Bioinformatics Group, Advanced Artificial Intelligence Research Laboratory, WuXi NextCODE, Cambridge, Massachusetts, USA
| | - Lingfeng Qin
- Department of Surgery, Yale School of Medicine, New Haven, Connecticut, USA
| | | | - Zehua Chen
- Computational Statistics and Bioinformatics Group, Advanced Artificial Intelligence Research Laboratory, WuXi NextCODE, Cambridge, Massachusetts, USA
| | - Sameh Yousef
- Department of Surgery, Yale School of Medicine, New Haven, Connecticut, USA
| | - Yang Jiao
- Department of Surgery, Yale School of Medicine, New Haven, Connecticut, USA
| | - Changshun He
- Department of Surgery, Yale School of Medicine, New Haven, Connecticut, USA
| | - Bo Jiang
- Department of Surgery, Yale School of Medicine, New Haven, Connecticut, USA
| | - Arina Korneva
- Department of Biomedical Engineering, Yale School of Engineering and Applied Science, New Haven, Connecticut, USA
| | - Matthew R Bersi
- Department of Biomedical Engineering, Yale School of Engineering and Applied Science, New Haven, Connecticut, USA
| | | | - Xinran Liu
- Cell Biology, Yale School of Medicine, New Haven, Connecticut, USA.,Center for Cellular and Molecular Imaging, EM Core Facility, Yale School of Medicine, New Haven, Connecticut, USA
| | | | - Arnar Geirsson
- Department of Surgery, Yale School of Medicine, New Haven, Connecticut, USA.,Program in Vascular Biology and Therapeutics, Yale School of Medicine, New Haven, Connecticut, USA
| | - Jeffrey R Gulcher
- Computational Statistics and Bioinformatics Group, Advanced Artificial Intelligence Research Laboratory, WuXi NextCODE, Cambridge, Massachusetts, USA
| | - Thomas W Chittenden
- Computational Statistics and Bioinformatics Group, Advanced Artificial Intelligence Research Laboratory, WuXi NextCODE, Cambridge, Massachusetts, USA
| | - Michael Simons
- Internal Medicine.,Program in Vascular Biology and Therapeutics, Yale School of Medicine, New Haven, Connecticut, USA
| | - Jay D Humphrey
- Department of Biomedical Engineering, Yale School of Engineering and Applied Science, New Haven, Connecticut, USA.,Program in Vascular Biology and Therapeutics, Yale School of Medicine, New Haven, Connecticut, USA
| | - George Tellides
- Department of Surgery, Yale School of Medicine, New Haven, Connecticut, USA.,Program in Vascular Biology and Therapeutics, Yale School of Medicine, New Haven, Connecticut, USA.,Veterans Affairs Connecticut Healthcare System, West Haven, Connecticut, USA
| |
Collapse
|
6
|
Smith SA, Newby AC, Bond M. Ending Restenosis: Inhibition of Vascular Smooth Muscle Cell Proliferation by cAMP. Cells 2019; 8:cells8111447. [PMID: 31744111 PMCID: PMC6912325 DOI: 10.3390/cells8111447] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2019] [Revised: 11/14/2019] [Accepted: 11/14/2019] [Indexed: 12/17/2022] Open
Abstract
Increased vascular smooth muscle cell (VSMC) proliferation contributes towards restenosis after angioplasty, vein graft intimal thickening and atherogenesis. The second messenger 3′ 5′ cyclic adenosine monophosphate (cAMP) plays an important role in maintaining VSMC quiescence in healthy vessels and repressing VSMC proliferation during resolution of vascular injury. Although the anti-mitogenic properties of cAMP in VSMC have been recognised for many years, it is only recently that we gained a detailed understanding of the underlying signalling mechanisms. Stimuli that elevate cAMP in VSMC inhibit G1-S phase cell cycle progression by inhibiting expression of cyclins and preventing S-Phase Kinase Associated Protein-2 (Skp2-mediated degradation of cyclin-dependent kinase inhibitors. Early studies implicated inhibition of MAPK signalling, although this does not fully explain the anti-mitogenic effects of cAMP. The cAMP effectors, Protein Kinase A (PKA) and Exchange Protein Activated by cAMP (EPAC) act together to inhibit VSMC proliferation by inducing Cyclic-AMP Response Element Binding protein (CREB) activity and inhibiting members of the RhoGTPases, which results in remodelling of the actin cytoskeleton. Cyclic-AMP induced actin remodelling controls proliferation by modulating the activity of Serum Response Factor (SRF) and TEA Domain Transcription Factors (TEAD), which regulate expression of genes required for proliferation. Here we review recent research characterising these mechanisms, highlighting novel drug targets that may allow the anti-mitogenic properties of cAMP to be harnessed therapeutically to limit restenosis.
Collapse
Affiliation(s)
| | | | - Mark Bond
- Correspondence: ; Tel.: +44-117-3423586
| |
Collapse
|
7
|
Dobaczewski M, Akrivakis S, Nasser K, Michael LH, Entman ML, Frangogiannis NG. Vascular Mural Cells in Healing Canine Myocardial Infarcts. J Histochem Cytochem 2016; 52:1019-29. [PMID: 15258177 DOI: 10.1369/jhc.3a6210.2004] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Angiogenesis is a critical process in healing of myocardial infarcts, leading to the formation of highly vascular granulation tissue. However, effective cardiac repair depends on mechanisms that inhibit the angiogenic process after a mature scar is formed, preventing inappropriate expansion of the fibrotic process. Using a canine model of reperfused myocardial infarction, we demonstrated that maturation of the infarct leads to the formation of neovessels, with a thick muscular coat, that demonstrate distinct morphological characteristics. Many of these “neoarterioles” lack a defined internal elastic lamina and demonstrate irregular deposits of extracellular matrix in the media. Vascular mural cells in healing infarcts undergo phenotypic changes, showing minimal expression of desmin during the proliferative phase (1 hr occlusion/7 days reperfusion) but in the mature scar (8 weeks reperfusion) acquire a phenotype similar to that of vascular smooth muscle cells in control areas. Non-muscle myosin heavy chains A and B are induced in infarct endothelial cells and myofibroblasts, respectively, but are not expressed in neovascular mural cells. Recruitment of a muscular coat and formation of neoarterioles in mature scars may inhibit endothelial cell proliferation and vascular sprouting, stabilizing the infarct vasculature.
Collapse
Affiliation(s)
- Marcin Dobaczewski
- Section of Cardiovascular Sciences, One Baylor Plaza M/S F-602, Baylor College of Medicine, Houston, TX 77030, USA
| | | | | | | | | | | |
Collapse
|
8
|
Orekhov AN, Bobryshev YV, Chistiakov DA. The complexity of cell composition of the intima of large arteries: focus on pericyte-like cells. Cardiovasc Res 2014; 103:438-51. [PMID: 25016615 DOI: 10.1093/cvr/cvu168] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Pericytes, which are also known as Rouget cells or perivascular cells, are considered to represent a likely distinct pool of vascular cells that are extremely branched and located mostly in the periphery of the vascular system. The family of pericytes is a heterogeneous cell population that includes pericytes and pericyte-like cells. Accumulated data indicate that networks of pericyte-like cells exist in normal non-atherosclerotic intima, and that pericyte-like cells can be involved in the development of atherosclerotic lesions from the very early stages of disease. The pathogenic role of arterial pericytes and pericyte-like cells also might be important in advanced and complicated atherosclerotic lesions via realizing mechanisms of vascular remodelling, ectopic ossification, intraplaque neovascularization, and probably thrombosis.
Collapse
Affiliation(s)
- Alexander N Orekhov
- Institute for Atherosclerosis Research, Skolkovo Innovative Center, Moscow, Russia
| | - Yuri V Bobryshev
- Institute for Atherosclerosis Research, Skolkovo Innovative Center, Moscow, Russia Faculty of Medicine, School of Medical Sciences, University of New South Wales, Kensington, Sydney, NSW 2052, Australia
| | - Dimitry A Chistiakov
- Department of Medical Nanobiotechnology, Pirogov Russian State Medical University, Moscow, Russia
| |
Collapse
|
9
|
Bi Y, Zhong H, Xu K, Qi X. Combination of Periaortic Elastase Incubation and Cholesterol-Rich Diet: A Novel Model of Atherosclerosis in Rabbit Abdominal Aorta. Cell Biochem Biophys 2013; 68:611-4. [DOI: 10.1007/s12013-013-9753-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
|
10
|
Lin Y, Chiba S, Suzuki A, Yamaguchi S, Nakanishi T, Matsumoto H, Ikeda Y, Ishibashi-Ueda H, Hirano KI, Kato S. Vascular smooth muscle cells isolated from adipose triglyceride lipase-deficient mice exhibit distinct phenotype and phenotypic plasticity. Biochem Biophys Res Commun 2013; 434:534-40. [PMID: 23583398 DOI: 10.1016/j.bbrc.2013.03.109] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2013] [Accepted: 03/19/2013] [Indexed: 10/27/2022]
Abstract
The alteration of triglyceride (TG) metabolism in vascular smooth muscle cells (SMC) is likely to be correlated with certain phenotype, though this has not been elucidated. Adipose triglyceride lipase (ATGL) exerts major TG catalytic activity in both adipotic and non-adipotic cells. In the present study, we isolated SMC from ATGL-deficient mice (ATGL(-/-)mSMC). ATGL(-/-)mSMC showed spontaneous TG accumulation with lower mitogenic response and smooth muscle actin (SMA) expression compared to ATGL (+/+)mSMC. Percentage of senescence-associated β-galactosidase positive cells was also increased in ATGL(-/-)mSMC. Real-time PCR followed by screening with focused DNA array analysis revealed up-regulated expression of glucokinase (1.7-fold), lipoprotein lipase (3.8-fold) and interleukin-6 (3.7-fold) and down-regulated expression of vascular endothelial growth factor-A (0.2-fold), type I collagen (0.5-fold), and transforming growth factor-β (0.4-fold) in ATGL(-/-)mSMC compared to ATGL(+/+)mSMC. Next, ectopic gene transfer of human ATGL was attempted using doxycycline (Dox)-regulatable myc-DDK-tagged adenovirus vector (AdvATGL). AdvATGL infection resulted in a reduction of TG accumulation with elevated mitogenic response and SMA expression, and decreased in senescent cell numbers in ATGL(-/-)mSMC. Moreover, deviated gene expression pattern in ATGL(-/-)mSMC was potentially corrected. Our data suggest that ATGL(-/-)mSMC have a distinct phenotype that may be related to vascular pathogenesis. Plasticity of SMC phenotypes correlated to lipid metabolism could be a therapeutic target.
Collapse
Affiliation(s)
- Yanhui Lin
- Department of Pathology and Cell Biology, Graduate School of Medicine, University of the Ryukyus, 207 Uehara, Nishihara, Okinawa 903-0215, Japan
| | | | | | | | | | | | | | | | | | | |
Collapse
|
11
|
Ikeda K, Souma Y, Akakabe Y, Kitamura Y, Matsuo K, Shimoda Y, Ueyama T, Matoba S, Yamada H, Okigaki M, Matsubara H. Macrophages play a unique role in the plaque calcification by enhancing the osteogenic signals exerted by vascular smooth muscle cells. Biochem Biophys Res Commun 2012; 425:39-44. [PMID: 22820183 DOI: 10.1016/j.bbrc.2012.07.045] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2012] [Accepted: 07/11/2012] [Indexed: 01/07/2023]
Abstract
Vascular calcification is a major risk factor for the cardiovascular disease, yet its underlying molecular mechanisms remain to be elucidated. Recently, we identified that osteogenic signals via bone morphogenetic protein (BMP)-2 exerted by vascular smooth muscle cells (VSMCs) play a crucial role in the formation of atherosclerotic plaque calcification. Here we report a synergistic interaction between macrophages and VSMCs with respect to plaque calcification. Treatment with conditioned medium (CM) of macrophages dramatically enhanced BMP-2 expression in VSMCs, while it substantially reduced the expression of matrix Gla-protein (MGP) that inhibits the BMP-2 osteogenic signaling. As a result, macrophages significantly accelerated the osteoblastic differentiation of C2C12 cells induced by VSMC-CM. In contrast, macrophage-CM did not enhance the osteoblastic gene expressions in VSMCs, indicating that macrophages unlikely induced the osteoblastic trans-differentiation of VSMCs. We then examined the effect of recombinant TNF-α and IL-1β on the VSMC-derived osteogenic signals. Similar to the macrophage-CM, both cytokines enhanced BMP-2 expression and reduced MGP expression in VSMCs. Nevertheless, only the neutralization of TNF-α but not IL-1β attenuated the effect of macrophage-CM on the expression of these genes in VSMCs, due to the very low concentration of IL-1β in the macrophage-CM. On the other hand, VSMCs significantly enhanced IL-1β expression in macrophages, which might in turn accelerate the VSMC-mediated osteogenic signals. Together, we identified a unique role of macrophages in the formation of plaque calcification in coordination with VSMCs. This interaction between macrophages and VSMCs is a potential therapeutic target to treat and prevent the atherosclerotic plaque calcification.
Collapse
Affiliation(s)
- Koji Ikeda
- Department of Cardiovascular Medicine, Kyoto Prefectural University School of Medicine, 465 Kajii, Kawaramachi-Hirokoji, Kamigyo, Kyoto 602-8566, Japan.
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
12
|
Last JA, Pan T, Ding Y, Reilly CM, Keller K, Acott TS, Fautsch MP, Murphy CJ, Russell P. Elastic modulus determination of normal and glaucomatous human trabecular meshwork. Invest Ophthalmol Vis Sci 2011; 52:2147-52. [PMID: 21220561 DOI: 10.1167/iovs.10-6342] [Citation(s) in RCA: 258] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
PURPOSE Elevated intraocular pressure (IOP) is a risk factor for glaucoma. The principal outflow pathway for aqueous humor in the human eye is through the trabecular meshwork (HTM) and Schlemm's canal (SC). The junction between the HTM and SC is thought to have a significant role in the regulation of IOP. A possible mechanism for the increased resistance to flow in glaucomatous eyes is an increase in stiffness (increased elastic modulus) of the HTM. In this study, the stiffness of the HTM in normal and glaucomatous tissue was compared, and a mathematical model was developed to predict the impact of changes in stiffness of the juxtacanalicular layer of HTM on flow dynamics through this region. METHODS Atomic force microscopy (AFM) was used to measure the elastic modulus of normal and glaucomatous HTM. According to these results, a model was developed that simulated the juxtacanalicular layer of the HTM as a flexible membrane with embedded pores. RESULTS The mean elastic modulus increased substantially in the glaucomatous HTM (mean = 80.8 kPa) compared with that in the normal HTM (mean = 4.0 kPa). Regional variation was identified across the glaucomatous HTM, possibly corresponding to the disease state. Mathematical modeling suggested an increased flow resistance with increasing HTM modulus. CONCLUSIONS The data indicate that the stiffness of glaucomatous HTM is significantly increased compared with that of normal HTM. Modeling exercises support substantial impairment in outflow facility with increased HTM stiffness. Alterations in the biophysical attributes of the HTM may participate directly in the onset and progression of glaucoma.
Collapse
Affiliation(s)
- Julie A Last
- Department of Chemical and Biological Engineering, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | | | | | | | | | | | | | | | | |
Collapse
|
13
|
Last JA, Russell P, Nealey PF, Murphy CJ. The applications of atomic force microscopy to vision science. Invest Ophthalmol Vis Sci 2011; 51:6083-94. [PMID: 21123767 DOI: 10.1167/iovs.10-5470] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
The atomic force microscope (AFM) is widely used in materials science and has found many applications in biological sciences but has been limited in use in vision science. The AFM can be used to image the topography of soft biological materials in their native environments. It can also be used to probe the mechanical properties of cells and extracellular matrices, including their intrinsic elastic modulus and receptor-ligand interactions. In this review, the operation of the AFM is described along with a review of how it has been thus far used in vision science. It is hoped that this review will serve to stimulate vision scientists to consider incorporating AFM as part of their research toolkit.
Collapse
Affiliation(s)
- Julie A Last
- Department of Chemical and Biological Engineering, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | | | | | | |
Collapse
|
14
|
Nakagawa Y, Ikeda K, Akakabe Y, Koide M, Uraoka M, Yutaka KT, Kurimoto-Nakano R, Takahashi T, Matoba S, Yamada H, Okigaki M, Matsubara H. Paracrine osteogenic signals via bone morphogenetic protein-2 accelerate the atherosclerotic intimal calcification in vivo. Arterioscler Thromb Vasc Biol 2010; 30:1908-15. [PMID: 20651281 DOI: 10.1161/atvbaha.110.206185] [Citation(s) in RCA: 102] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
OBJECTIVE Vascular calcification is an important risk factor for cardiovascular diseases. Here, we investigated a role of dedifferentiated vascular smooth muscle cells (VSMCs) in the atherosclerotic intimal calcification. METHODS AND RESULTS We prepared human cultured VSMCs in either redifferentiatiated or dedifferentiated state and analyzed the gene expressions of bone-calcification regulatory factors. Expression of bone morphogenetic protein-2 (BMP-2), a potent initiator for osteoblast differentiation, was significantly enhanced in dedifferentiated VSMCs. Furthermore, endogenous BMP-2 antagonists, such as noggin, chordin, and matrix gamma-carboxyglutamic acid protein, were all downregulated in the dedifferentiated VSMCs. Conditioned medium from dedifferentiated VSMCs, but not from redifferentiated VSMCs, stimulated the osteoblastic differentiation of the mesenchymal progenitor C2C12 cells, which was abolished by BMP-2 knockdown. In atherosclerotic intima from apolipoprotein (apo)E-deficient mice, αSM-actin-positive cells, presumably dedifferentiated VSMCs, expressed BMP-2. We generated BMP-2-transgenic mice using αSM-actin promoter and crossed them with apoE-deficient mice (BMP-2-transgenic/apoE-knockout). Significantly accelerated atherosclerotic intimal calcification was detected in BMP-2-transgenic/apoE-knockout mice, although serum lipid concentration and atherosclerotic plaque size were not different from those in apoE-knockout mice. Enhanced calcification appeared to be associated with the frequent emergence of osteoblast-like cells in atherosclerotic intima in BMP-2-transgenic/apoE-knockout mice. CONCLUSIONS Our findings collectively demonstrate an important role of dedifferentiated VSMCs in the pathophysiology of atherosclerotic calcification through activating paracrine BMP-2 osteogenic signals.
Collapse
Affiliation(s)
- Yusuke Nakagawa
- Department of Cardiovascular Medicine, Kyoto Prefectural University School of Medicine, Kamigyo, Kyoto, Japan
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
15
|
|
16
|
Perrotta I, Brunelli E, Sciangula A, Zuccalà V, Donato G, Tripepi S, Martinelli GL, Cassese M. Inducible and endothelial nitric oxide synthase expression in human atherogenesis: an immunohistochemical and ultrastructural study. Cardiovasc Pathol 2009; 18:361-8. [DOI: 10.1016/j.carpath.2008.08.005] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/10/2008] [Revised: 06/25/2008] [Accepted: 08/19/2008] [Indexed: 10/21/2022] Open
|
17
|
Last JA, Liliensiek SJ, Nealey PF, Murphy CJ. Determining the mechanical properties of human corneal basement membranes with atomic force microscopy. J Struct Biol 2009; 167:19-24. [PMID: 19341800 DOI: 10.1016/j.jsb.2009.03.012] [Citation(s) in RCA: 143] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2008] [Revised: 02/17/2009] [Accepted: 03/24/2009] [Indexed: 01/17/2023]
Abstract
Biophysical cues such as substrate modulus have been shown to influence a variety of cell behaviors. We have determined the elastic modulus of the anterior basement membrane and Descemet's membrane of the human cornea with atomic force microscopy (AFM). A spherical probe was used with a radius approximating that of a typical cell focal adhesion. Values obtained for the elastic modulus of the anterior basement membrane range from 2 to 15 kPa, with a mean of 7.5+/-4.2 kPa. The elastic modulus of Descemet's membrane was found to be slightly higher than those observed for the anterior basement membrane, with a mean of 50+/-17.8 kPa and a range of 20-80 kPa. The topography of Descemet's membrane has been shown to be similar to that of the anterior basement, but with smaller pore sizes resulting in a more tightly packed structure. This structural difference may account for the observed modulus differences. The determination of these values will allow for the design of a better model of the cellular environment as well as aid in the design and fabrication of artificial corneas.
Collapse
Affiliation(s)
- Julie A Last
- Department of Surgical Sciences, School of Veterinary Medicine, 2015 Linden Drive, University of Wisconsin, Madison, WI 53706, USA
| | | | | | | |
Collapse
|
18
|
Patel MK, Clunn GF, Lymn JS, Austin O, Hughes AD. Effect of serum withdrawal on the contribution of L-type calcium channels (CaV1.2) to intracellular Ca2+ responses and chemotaxis in cultured human vascular smooth muscle cells. Br J Pharmacol 2005; 145:811-7. [PMID: 15880143 PMCID: PMC1576191 DOI: 10.1038/sj.bjp.0706237] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Vascular smooth muscle cell (VSMC) chemotaxis is fundamental to atherosclerosis and intimal hyperplasia. An increase in intracellular Ca2+ [Ca2+]i is an important signal in chemotaxis, but the role of L-type calcium channels (CaV1.2) in this response in human vascular smooth muscle cells (hVSMC) has not been examined. hVSMC were grown from explant cultures of saphenous vein. Confluent hVSMC at passage 3 were studied after culture in medium containing 15% foetal calf serum (FCS) (randomly cycling) or following serum deprivation for up to 7 days. Smooth muscle alpha-actin was measured by immunoblotting and immunofluorescence microscopy. [Ca2+]i was measured using fura 2 fluorimetry. Chemotaxis was measured using a modified Boyden chamber technique and cell attachment to gelatin-coated plates was also quantified. The number and affinity of dihydropyridine-binding sites was assessed using [5-methyl-3H]PN 200-110 binding. In randomly cycling cells, the calcium channel agonist, Bay K 8644a and 100 mM KCl did not affect [Ca2+]i. In addition, the rise in [Ca2+]i induced by platelet-derived growth factor-BB (PDGF) was unaffected by the CaV1.2 antagonists, amlodipine and verapamil. In randomly cycling cells amlodipine did not affect PDGF-induced migration. In serum-deprived cells, smooth muscle alpha-actin was increased and Bay K 8644a and 100 mM KCl increased [Ca2+]i. PDGF-induced rises in [Ca2+]i were also inhibited by amlodipine and verapamil. The ability of Bay K 8644a to increase [Ca2+]i and verapamil to inhibit PDGF-induced rises in [Ca2+]i was evident within 3 days after serum withdrawal. In serum-deprived hVSMC Bay K 8644a induced chemotaxis and amlodipine inhibited PDGF-induced migration. Cell attachment in the presence of PDGF was unaffected by amlodipine in either randomly cycling or serum-deprived hVSMC. Serum withdrawal was associated with a decrease in the maximum number of dihydropyridine-binding sites (B(max)) and a decrease in affinity (K(D)). Serum deprivation of hVSMC results in increased expression of smooth muscle alpha-actin, a marker of more differentiated status, and increased [Ca2+]i responses and chemotaxis mediated by CaV1.2. These observations may have important implications for understanding the therapeutic benefits of calcium channel antagonists in cardiovascular disease.
Collapse
MESH Headings
- 3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethyl-5-nitro-4-(2-(trifluoromethyl)phenyl)-, Methyl ester/pharmacology
- Actins/metabolism
- Amlodipine/pharmacology
- Becaplermin
- Calcium/metabolism
- Calcium Channel Agonists/pharmacology
- Calcium Channel Blockers/pharmacology
- Calcium Channels, L-Type/drug effects
- Calcium Channels, L-Type/metabolism
- Cells, Cultured
- Chemotaxis/drug effects
- Chemotaxis/physiology
- Culture Media, Serum-Free/pharmacology
- Humans
- Muscle, Smooth, Vascular/cytology
- Muscle, Smooth, Vascular/drug effects
- Muscle, Smooth, Vascular/metabolism
- Myocytes, Smooth Muscle/drug effects
- Myocytes, Smooth Muscle/metabolism
- Platelet-Derived Growth Factor/pharmacology
- Proto-Oncogene Proteins c-sis
- Saphenous Vein/cytology
- Verapamil/pharmacology
Collapse
Affiliation(s)
- Mahendra K Patel
- Clinical Pharmacology, NHLI Division, Faculty of Medicine, Imperial College London, St Mary's Campus, South Wharf Road, London W2 1NY
| | - Gerard F Clunn
- Clinical Pharmacology, NHLI Division, Faculty of Medicine, Imperial College London, St Mary's Campus, South Wharf Road, London W2 1NY
| | - Joanne S Lymn
- Clinical Pharmacology, NHLI Division, Faculty of Medicine, Imperial College London, St Mary's Campus, South Wharf Road, London W2 1NY
| | - Oneka Austin
- Clinical Pharmacology, NHLI Division, Faculty of Medicine, Imperial College London, St Mary's Campus, South Wharf Road, London W2 1NY
| | - Alun D Hughes
- Clinical Pharmacology, NHLI Division, Faculty of Medicine, Imperial College London, St Mary's Campus, South Wharf Road, London W2 1NY
- Author for correspondence:
| |
Collapse
|
19
|
Gamble W. Atherosclerosis: the carbonic anhydrase, carbon dioxide, calcium concerted theory. J Theor Biol 2005; 239:16-21. [PMID: 16183078 DOI: 10.1016/j.jtbi.2005.07.008] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2005] [Revised: 07/12/2005] [Accepted: 07/15/2005] [Indexed: 11/16/2022]
Abstract
Atherosclerosis is a dynamic multifaceted disease which affects the aorta and its major branches, characterized by the presence of lesions called atheromatous plaques. The plaque is a focal thickening of the intima caused by proliferation of smooth muscle cells, and the deposition of cholesterol, other lipids, hydroxyapatite and fibrous connective tissue. It is proposed that the determinant step of the process which leads to the disease atherosclerosis is the calcium precipitation which traps cholesterol in the plaque precursor matrix which contains lipoproteins, calcium carbonate, hydroxyapapatite, triglycerides, albumin, calmodulin and other proteins. The bear, a species which does not contract the disease is used as an example in support of the hypothesis. The bear's ability to regulate calcium levels and the regulation of acid base balance via regulation of carbon dioxide levels permits the control of the determinant step of plaque formation, that is calcification of the plaque.
Collapse
Affiliation(s)
- Wilbert Gamble
- Department of Biochemistry and Biophysics, Oregon State University, 2011 ALS, Corvallis, OR 97331 USA.
| |
Collapse
|
20
|
Lener T, Burgstaller G, Crimaldi L, Lach S, Gimona M. Matrix-degrading podosomes in smooth muscle cells. Eur J Cell Biol 2005; 85:183-9. [PMID: 16546560 DOI: 10.1016/j.ejcb.2005.08.001] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Activation of protein kinase C by phorbol esters triggers the remodelling of the actin cytoskeleton and the formation of podosomes in smooth muscle cells (SMCs). Regional control of actin dynamics at specialised microdomains results in a local reduction in contractile forces. The molecular basis for this local inhibition of contractility includes the clustering of cortactin during podosome formation (which precedes the rapid, local dispersion of myosin, tropomyosin and h1 calponin), and the specific recruitment of 110-kDa actin filament-associated protein (AFAP-110) and 190-kDa Rho-specific GTPase-activating protein (p190RhoGAP) to the microdomains. Podosome formation also correlates with cell polarisation, the induction of cell motility, and local degradation of the extracellular matrix. These findings may provide explanations for the complex mechanisms underlying SMC invasion in the course of the development of atherosclerotic lesions and restenosis, and support the concept that matrix degradation and the concomitant engagement of the molecular machinery initiating actin-based cell motility drive tissue invasion in smooth muscle.
Collapse
Affiliation(s)
- Thomas Lener
- Division of Cell Biology, University of Salzburg, Hellbrunnerstrasse 34, A-5020 Salzburg, Austria
| | | | | | | | | |
Collapse
|
21
|
Burgstaller G, Gimona M. Podosome-mediated matrix resorption and cell motility in vascular smooth muscle cells. Am J Physiol Heart Circ Physiol 2005; 288:H3001-5. [PMID: 15695563 DOI: 10.1152/ajpheart.01002.2004] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The migration of vascular smooth muscle cells (VSMCs) is a principal factor for the development and progression of vascular diseases. In addition, phenotypic alteration from the contractile (differentiated) to the synthetic (dedifferentiated) state and a proteolytic process in the form of extra cellular matrix degradation are necessary for SMC invasion. The actual mechanism leading to the focal degradation of basement membrane matrix components and, hence, SMC migration within the tissue itself is, however, unclear. In response to phorbol ester [phorbol-12,13-dibutyrate (PDBu)], VSMCs in culture form podosomes, dynamic organelles critical for cell adhesion and substrate degradation that are typically found in invasive cells and cells that cross tissue boundaries. Here, we show that PDBu-stimulated VSMCs resorb the extracellular matrix at the sites of podosomes. Podosome formation correlates with an increased polarization of VSMCs on fibronectin- or collagen-coated flexible substrates in addition to a concomitant induction of cell motility. VSMCs embedded in reconstituted basement membrane support adopt the typical spindle-shaped morphology of differentiated SMCs in vivo and, after PDBu treatment, form peripheral lamellipodia and podosomes around their matrix-contacting surface. Our findings demonstrate that podosome formation is the potential mechanism underlying the ability of VSMCs to traverse the surrounding basement membrane and escape the barrier of the tunica media in vascular diseases.
Collapse
Affiliation(s)
- Gerald Burgstaller
- Consorzio Mario Negri Sud, Dept. of Cell Biology and Oncology, Unit of Actin Cytoskeleton Regulation, Via Nazionale 8a, I-66030 Santa Maria Imbaro, Italy
| | | |
Collapse
|
22
|
Engler AJ, Griffin MA, Sen S, Bönnemann CG, Sweeney HL, Discher DE. Myotubes differentiate optimally on substrates with tissue-like stiffness: pathological implications for soft or stiff microenvironments. ACTA ACUST UNITED AC 2004; 166:877-87. [PMID: 15364962 PMCID: PMC2172122 DOI: 10.1083/jcb.200405004] [Citation(s) in RCA: 1172] [Impact Index Per Article: 58.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Contractile myocytes provide a test of the hypothesis that cells sense their mechanical as well as molecular microenvironment, altering expression, organization, and/or morphology accordingly. Here, myoblasts were cultured on collagen strips attached to glass or polymer gels of varied elasticity. Subsequent fusion into myotubes occurs independent of substrate flexibility. However, myosin/actin striations emerge later only on gels with stiffness typical of normal muscle (passive Young's modulus, E approximately 12 kPa). On glass and much softer or stiffer gels, including gels emulating stiff dystrophic muscle, cells do not striate. In addition, myotubes grown on top of a compliant bottom layer of glass-attached myotubes (but not softer fibroblasts) will striate, whereas the bottom cells will only assemble stress fibers and vinculin-rich adhesions. Unlike sarcomere formation, adhesion strength increases monotonically versus substrate stiffness with strongest adhesion on glass. These findings have major implications for in vivo introduction of stem cells into diseased or damaged striated muscle of altered mechanical composition.
Collapse
Affiliation(s)
- Adam J Engler
- School of Engineering and Applied Science, University of Pennsylvania, Philadelphia, PA 19104, USA
| | | | | | | | | | | |
Collapse
|
23
|
Abstract
DNA methylation is a form of epigenetic modification of the genome that can regulate gene expression. Hypermethylation of CpG islands in the promoter areas leads to decreased gene expression, whereas promoters of actively transcribed genes remain nonmethylated. Because of cellular proliferation and monoclonality of at least some of the lesion cells, atherosclerotic lesions have been compared with benign vascular tumors.1,2 However, although genetic and epigenetic background favors neoplastic transformation, atherosclerotic plaques never develop to malignant tumors. Among cancer cells, common features are genome-wide hypomethylation, which correlates with transformation and tumor progression. Recent studies have shown that DNA methylation changes occur also during atherogenesis and may contribute to the lesion development.
Collapse
|
24
|
Patel RP, Moellering D, Murphy-Ullrich J, Jo H, Beckman JS, Darley-Usmar VM. Cell signaling by reactive nitrogen and oxygen species in atherosclerosis. Free Radic Biol Med 2000; 28:1780-94. [PMID: 10946220 DOI: 10.1016/s0891-5849(00)00235-5] [Citation(s) in RCA: 166] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The production of reactive oxygen and nitrogen species has been implicated in atherosclerosis principally as means of damaging low-density lipoprotein that in turn initiates the accumulation of cholesterol in macrophages. The diversity of novel oxidative modifications to lipids and proteins recently identified in atherosclerotic lesions has revealed surprising complexity in the mechanisms of oxidative damage and their potential role in atherosclerosis. Oxidative or nitrosative stress does not completely consume intracellular antioxidants leading to cell death as previously thought. Rather, oxidative and nitrosative stress have a more subtle impact on the atherogenic process by modulating intracellular signaling pathways in vascular tissues to affect inflammatory cell adhesion, migration, proliferation, and differentiation. Furthermore, cellular responses can affect the production of nitric oxide, which in turn can strongly influence the nature of oxidative modifications occurring in atherosclerosis. The dynamic interactions between endogenous low concentrations of oxidants or reactive nitrogen species with intracellular signaling pathways may have a general role in processes affecting wound healing to apoptosis, which can provide novel insights into the pathogenesis of atherosclerosis.
Collapse
Affiliation(s)
- R P Patel
- Center for Free Radical Biology, University of Alabama, Birmingham, AL 35294-0019, USA
| | | | | | | | | | | |
Collapse
|
25
|
Song J, Wan Y, Rolfe BE, Campbell JH, Campbell GR. Effect of estrogen on vascular smooth muscle cells is dependent upon cellular phenotype. Atherosclerosis 1998; 140:97-104. [PMID: 9733220 DOI: 10.1016/s0021-9150(98)00122-1] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
To investigate the growth-regulating action of estrogen on vascular smooth muscle cells (SMC), effects of beta-17-estradiol (beta-E2) on phenotypic modulation and proliferation of rabbit aortic SMC were observed in vitro. At 10(-8)M, beta-E2 significantly slowed the decrease in volume fraction of myofilaments (Vv myo) of freshly dispersed SMCs in primary culture, indicating an inhibitory effect of beta-E2 on spontaneous phenotypic modulation of SMC from a contractile to a synthetic phenotype. Freshly dispersed SMCs treated with beta-E2 also had a relatively longer quiescent phase than control cells before intense proliferation occurred. This was in contrast to SMCs in passage 2 3 (synthetic state), where beta-E2-treated cells replicated significantly faster than untreated cells. beta-E2 also markedly enhanced the serum-induced DNA synthesis of synthetic SMCs in a concentration-dependent manner within physiological range (10(-10)to 10(-8)M). These findings indicate that the growth-regulating effect of estrogen on vascular SMC is dependent on the cell's phenotypic state. It delays the cell cycle re-entry of the contractile SMCs by retarding their phenotypic modulation: however, once cells have modulated to the synthetic phenotype, it promotes their replication.
Collapse
Affiliation(s)
- J Song
- Centre for Research in Vascular Biology, Department of Anatomical Sciences, University of Queensland, Brisbane, Australia
| | | | | | | | | |
Collapse
|
26
|
Firulli AB, Han D, Kelly-Roloff L, Koteliansky VE, Schwartz SM, Olson EN, Miano JM. A comparative molecular analysis of four rat smooth muscle cell lines. In Vitro Cell Dev Biol Anim 1998; 34:217-26. [PMID: 9557939 DOI: 10.1007/s11626-998-0127-5] [Citation(s) in RCA: 68] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Transcriptional regulation of smooth muscle cell (SMC) differentiation is a rapidly growing area of interest that has relevance for understanding intimal disease. Despite the wealth of data accumulating in vitro, however, no study has compared the cell-specific marker profile, transfectability, promoter activity, and growth characteristics among several SMC culture systems. Accordingly, we performed a comprehensive analysis of the marker profile, growth properties, transfectability, and SMC promoter activity in four rat SMC lines (A7r5, adult and pup aortic, and PAC1). Despite alterations in chromosomal number and structure, A7r5, adult aortic, and PAC1 cells express all SMC markers studied including SM alpha-actin, SM calponin, SM22, tropoelastin, and to a lesser extent, SM myosin heavy chain (SMMHC). In contrast, pup aortic cells express very low or undetectable levels of all the above markers except tropoelastin. Adult aortic, pup, and PAC1 cells display similar growth curves and levels of proto-oncogene transcripts, whereas those in the A7r5 line are comparatively less. All cell lines studied except pup cells show expression of SMC differentiation genes during active growth, indicating that growth and differentiation are not mutually exclusive in cultured smooth muscle. Transfection studies reveal dramatic differences in DNA uptake and SMC-restricted promoter activity between cell lines. Collectively, these results provide detailed information relating to SMC molecular biology in culture that should facilitate the selection of a cell line for studying the transcriptional regulatory mechanisms underlying SMC differentiation.
Collapse
Affiliation(s)
- A B Firulli
- Hamon Center for Basic Research, The University of Texas Southwestern Medical Center at Dallas, 75235-9148, USA
| | | | | | | | | | | | | |
Collapse
|
27
|
McAndrew J, Patel RP, Jo H, Cornwell T, Lincoln T, Moellering D, White CR, Matalon S, Darley-Usmar V. The interplay of nitric oxide and peroxynitrite with signal transduction pathways: implications for disease. Semin Perinatol 1997; 21:351-66. [PMID: 9352609 DOI: 10.1016/s0146-0005(97)80002-x] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Since the discovery that at least one form of endothelium derived relaxing factor is nitric oxide (NO), numerous studies have uncovered diverse roles for this free radical in a variety of physiological and pathophysiological processes. NO production, a process mediated by a family of enzymes termed NO synthases, has been detected in most cell types. Many of the effects of NO are thought to be mediated through its direct interaction with specific and defined cell signaling pathways. The nature of such interactions are highly dependent on the concentration of NO and cell type. Furthermore, specific NO derived reaction products, such as peroxynitrite, also have the potential to effect cell signal transduction events. As with NO, this can occur through diverse mechanisms and depends on concentration and cell type. It is perhaps not surprising that the reported effects of NO in different disease states are often conflicting. In this brief overview, a framework for placing these apparently disparate properties of NO will be described and will focus on the effects of NO and peroxynitrite on signaling pathways.
Collapse
Affiliation(s)
- J McAndrew
- Department of Pathology, University of Birmingham at Alabama, USA
| | | | | | | | | | | | | | | | | |
Collapse
|
28
|
van der Loop FT, Schaart G, Timmer ED, Ramaekers FC, van Eys GJ. Smoothelin, a novel cytoskeletal protein specific for smooth muscle cells. J Biophys Biochem Cytol 1996; 134:401-11. [PMID: 8707825 PMCID: PMC2120883 DOI: 10.1083/jcb.134.2.401] [Citation(s) in RCA: 178] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
The characterization of a novel 59-kD cytoskeletal protein is described. It is exclusively observed in smooth muscle cells by Northern blotting and immunohistochemical analysis and therefore designated "smoothelin." A human smooth muscle cDNA library was screened with the monoclonal antibody R4A, and a full-size cDNA of the protein was selected. The cDNA was sequenced and appeared to contain a 1,113-bp open reading frame. Based on the cDNA sequence, the calculated molecular weight of the polypeptide was 40 kD and it was demonstrated to contain two N-glycosylation sites. Computer assisted analysis at the protein level revealed a 56-amino acid domain with homologies of approximately 40% with a sequence bordering the actin-binding domains of dystrophin, utrophin, beta-spectrin and alpha-actinin. In situ hybridization demonstrated that human smoothelin is encoded by a single copy gene which is located on chromosome 22. Immunohistochemistry and Western blotting revealed synthesis of smoothelin in smooth muscle of species evolutionarily as far apart as human and teleost. Northern blotting indicated that sequence as well as size of the mRNA (approximately 1,500 bases) are conserved among vertebrates. Cell fractionation studies and differential centrifugation showed that the protein cannot be extracted with Triton X-100, which indicates that it is a part of the cytoskeleton. Transfection of the human cDNA into smooth muscle cells and COS7 cells produced a protein of 59 kD, which assembled into a filamentous network. However, in rat heart-derived myoblasts association with stress fibers was most prominent. Smoothelin was not detected in primary or long term smooth muscle cell cultures. Also, transcription of smoothelin mRNA was almost instantly halted in smooth muscle tissue explants. We conclude that smoothelin is a new cytoskeletal protein that is only found in contractile smooth muscle cells and does not belong to one of the classes of structural proteins presently known.
Collapse
Affiliation(s)
- F T van der Loop
- Department of Molecular Cell Biology & Genetics, University of Limburg, Maastricht, The Netherlands
| | | | | | | | | |
Collapse
|
29
|
Parish MA, Grossi EA, Baumann FG, Asai T, Rifkin DB, Colvin SB, Galloway AC. Effects of a single administration of fibroblast growth factor on vascular wall reaction to injury. Ann Thorac Surg 1995; 59:948-54. [PMID: 7695423 DOI: 10.1016/0003-4975(95)00016-e] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Expansion of the vascular wall through formation of neointimal fibromuscular lesions is the basic mechanism underlying stenosis of vascular grafts, restenosis of arteries treated by balloon angioplasty, and other major cardiovascular problems. This study examined the effect of a single, systemic, low dose of basic fibroblast growth factor (bFGF) on formation of neointimal fibromuscular lesions in response to injury. New Zealand white rabbits (n = 76) were subjected to balloon injury of the abdominal aorta. Forty-five rabbits were given a single intravenous dose of bFGF (0.5 microgram/kg) immediately after injury, and 31 rabbits were given only the vehicle solution as controls. After 2 (n = 15), 5 (n = 21), 14 (n = 29), or 28 (n = 11) days the rabbits were sacrificed. Those rabbits receiving the single administration of bFGF exhibited significantly greater intimal thickening (intima/media ratio) than the control group at 5 days (mean +/- standard error of the mean, 0.091 +/- 0.009 versus 0.058 +/- 0.006; p < 0.002), but not at 14 or 28 days. These results were achieved without any significant differences in mitotic indices, as determined by a mitostatic method, between the two groups at any postinjury interval examined. The findings suggest that a single systemic dose of exogenous bFGF has a relatively long term effect on enhancing the neointimal response to vascular injury. Therefore, local control of endogenous bFGF may be useful in limiting formation of vascular neointimal fibromuscular lesions, thus improving the long-term results of vascular grafts, balloon angioplasty, and other cardiovascular procedures.
Collapse
Affiliation(s)
- M A Parish
- Department of Surgery, New York University Medical Center, New York 10016
| | | | | | | | | | | | | |
Collapse
|
30
|
Abstract
Scatter factor (hepatocyte growth factor) is a mesenchyme-derived cytokine that stimulates motility, proliferation, and morphogenesis of epithelia. These responses are transduced through the c-met protooncogene product, a transmembrane tyrosine kinase that functions as the SF receptor. SF is a potent angiogenic molecule, and its angiogenic activity is mediated primarily through direct actions on endothelial cells. These include stimulation of cell motility, proliferation, protease production, invasion, and organization into capillary-like tubes. SF is chronically overexpressed in tumors, suggesting that it may function as a tumor angiogenesis factor. SF production in tumors may be due, in part, to an abnormal tumor-stroma interaction, in which the tumor cells secrete factors (SF-IFs) that stimulate SF production by tumor-associated stromal cells. Studies suggest a link between tumor suppressors (antioncogenes) and inhibition of angiogenesis. We hypothesize that tumor suppressor gene mutations may contribute to the activation of an SF-IF-->SF-->c-met pathway, leading to an invasive and angiogenic tumor phenotype. Modulation of this pathway may, ultimately, provide clinically useful methods of enhancing or inhibiting angiogenesis.
Collapse
Affiliation(s)
- E M Rosen
- Department of Radiation Oncology, Long Island Jewish Medical Center, New Hyde Park, New York 11042, USA
| | | |
Collapse
|
31
|
Ruckman JL, Luvalle PA, Hill KE, Giro MG, Davidson JM. Phenotypic stability and variation in cells of the porcine aorta: collagen and elastin production. Matrix Biol 1994; 14:135-45. [PMID: 7520335 DOI: 10.1016/0945-053x(94)90003-5] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
The extracellular matrix of the developing vasculature varies in composition as a function of time and position. Cellular models of vascular biology and pathology depend on the assumption that stable phenotypic characteristics of vascular cells can be propagated through several generations of in vitro cultivation. We show that the positional and developmental heterogeneity of matrix phenotypes in the porcine aorta are expressed by explanted vascular smooth muscle cell (SMC) and adventitial cell populations for a limited number of passages. Elastin was expressed most highly by thoracic SMC while interstitial collagen production was usually maximal in abdominal segments. Parallel gradients of collagen types I, III and V, detected by specific ELISA assays, were expressed in early-passage SMC. Adventitial cell populations from the abdominal aorta of the neonatal pig accumulated significant levels of collagen, while these fibroblasts produced less than 10% of the elastin made by SMC. All cell populations expressed alpha-smooth muscle actin in vitro. Gradients of collagen and elastin expression were evident for no more than three passages, and direct outgrowth of cells without limited digestion of the matrix further reduced phenotypic stability. Variation and decline of the elastin phenotype could be due to hypermethylation of regulatory sequences in the elastin gene or trans-acting factors, but elastin production was dose-dependently stimulated to a similar extent (100%; 10 microM 5-azacytidine) in all segmental SMC populations at early (p1) and late (p3) passage. These data indicated that faithful reflection of in vivo SMC behavior was limited to a few population doublings, at least under standard culture conditions. Modification of the cellular environment by reducing serum factors, changing matrix, or adding mechanical stimulation may increase phenotypic stability.
Collapse
Affiliation(s)
- J L Ruckman
- Department of Pathology, University of Utah School of Medicine, Salt Lake City
| | | | | | | | | |
Collapse
|
32
|
Ferns GA, Stewart-Lee AL, Anggård EE. Arterial response to mechanical injury: balloon catheter de-endothelialization. Atherosclerosis 1992; 92:89-104. [PMID: 1385956 DOI: 10.1016/0021-9150(92)90268-l] [Citation(s) in RCA: 90] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Coronary angioplasty has been used clinically for over a decade. Its initial promise as an alternative to coronary bypass surgery has only partially been fulfilled because of the high rate of post-operative restenosis. A number of animal models have been devised to study this phenomenon and although none is entirely satisfactory, they have, together with recent advances in molecular biology provided an insight into the cellular mechanisms that may contribute to this complication. This knowledge may ultimately lead to a means of therapeutic intervention. This review summarises our present understanding of the pathology of post-angioplasty re-stenosis as revealed by studies using the balloon catheter de-endothelialization model, and discusses some of the intervention strategies that have been attempted.
Collapse
Affiliation(s)
- G A Ferns
- William Harvey Research Institute, St. Bartholomew's Hospital Medical College University of London, U.K
| | | | | |
Collapse
|
33
|
Mecham RP, Stenmark KR, Parks WC. Connective tissue production by vascular smooth muscle in development and disease. Chest 1991; 99:43S-47S. [PMID: 1997269 DOI: 10.1378/chest.99.3_supplement.43s] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Affiliation(s)
- R P Mecham
- Department of Medicine, Jewish Hospital, Washington University Medical Center, St Louis
| | | | | |
Collapse
|
34
|
McMurray HF, Parrott DP, Bowyer DE. A standardised method of culturing aortic explants, suitable for the study of factors affecting the phenotypic modulation, migration and proliferation of aortic smooth muscle cells. Atherosclerosis 1991; 86:227-37. [PMID: 1872916 DOI: 10.1016/0021-9150(91)90219-s] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The study of factors affecting phenotypic change and growth of aortic smooth muscle cells (SMC) typically involves either the isolation of SMC by enzymatic dissociation or observation of outgrowth of cells from primary explants of vascular tissue. Explants provide a system in which the growth of cells can be investigated without dissociating them totally from their normal environment and avoids some of the problems of variability associated with enzymatic digestion. We describe here a standardised method for the preparation of medial explants of arterial tissue using a McIlwain tissue chopper, which is both fast and reproducible. Measurement was made of the percentage of explants showing outgrowth and of the distance migrated by cells at various times after plating explants singly into wells of a 96-well plate. Using this method, by 12 days after explanting, more than 95% of explants from normal rabbit aorta had shown outgrowth, in contrast to only 50% of explants prepared using a scalpel blade. Explants from atherosclerotic rabbit aorta showed a shorter lag phase before outgrowth commenced than explants from normal rabbit aorta of a similar age, but the subsequent rate of growth was the same. In contrast, when explants of normal rabbit aorta were grown in hyperlipidic rabbit serum, the lag phase was the same as for normal serum, but the subsequent rate of growth was greater. Explants from normal rabbit aorta treated with heparin showed an increased lag phase but reduced rate of growth. Treatment with heparinase decreased the lag phase and increased the rate of growth as did elastase.
Collapse
Affiliation(s)
- H F McMurray
- Department of Pathology, University of Cambridge, U.K
| | | | | |
Collapse
|
35
|
Abstract
In a human, the cells function adequately to the needs of the organism, and to their own needs. Consequently, adequate cell function is comprised of the organism-oriented, and cell-oriented functions. It is suggested that an independent stage in the pathogenesis of a chronic disease exists which so far has not been considered. This is the disturbance of the cell-oriented function of the cells involved. This initial stage may last for years and decades, whereas function of the organ remains preserved. Organism-oriented cellular function appears to become involved in the pathologic process long after the disease has actually started. At this time the cells themselves are severely impaired, and as a result a disease acquires its progressive, irreversible course. Pathogenesis of atherosclerosis is considered as an example of the above-mentioned developments.
Collapse
|
36
|
Betz E, Hämmerle H, Strohschneider T. Inhibition of smooth muscle cell proliferation and endothelial permeability with flunarizine in vitro and in experimental atheromas. RESEARCH IN EXPERIMENTAL MEDICINE. ZEITSCHRIFT FUR DIE GESAMTE EXPERIMENTELLE MEDIZIN EINSCHLIESSLICH EXPERIMENTELLER CHIRURGIE 1985; 185:325-40. [PMID: 4048654 DOI: 10.1007/bf01851958] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Repeated weak electrical stimulations of rabbit carotid artery walls with implanted electrodes cause intimal proliferations of smooth muscle cells (SMC) and lead to fibromuscular plaques beneath the anode. If the animals receive a cholesterol-enriched diet the plaques become typical atheromas. The endothelial lining is maintained. The procedure for the production of an atheroma with 11 +/- 4 layers of SMC lasts 4 weeks. Addition of the calcium antagonist Flunarizine to the food during the stimulation periods inhibits the growth of the plaque. The inhibition is dose-dependent. Whether the drug inhibits atherogenesis by direct action on SMC or via an effect on permeation of macromolecules through the endothelium has been studied by measurement of (1) peroxidase (MW 40,000 dalton) permeability through the stimulated endothelium of the artery and (2) the inhibitory effects of Flunarizine on cultures of arterial SMC. Endothelial permeability increases for some hours after stimulation mainly beneath the anode. Flunarizine inhibits the permeation of peroxidase through the endothelial lining for the most part by its action on intercellular transport. The drug also inhibits the growth of SMC in mass cultures and clone cultures. The inhibition of proliferation is not specific for SMC. Skin fibroblasts obtained from the same animals as the artery smooth muscle cells are also inhibited in mass cultures and clone cultures. From the results it can be concluded that Flunarizine exerts its inhibitory action not only by its effect on the permeation through the endothelial lining but by a combined action on permeability and proliferation of cells in the artery wall.
Collapse
|
37
|
Abstract
Numerous spontaneous lesions, characterized principally by a gap in the internal elastic lamina, form with age in the caudal artery of the young, male Wistar rat. Such newly formed lesions were studied, with special reference to the state of the endothelium, using three techniques: "en face" examination of silver-stained caudal artery, [3H]thymidine autoradiography, and light and electron microscopy. In many, but perhaps not all cases, areas of endothelium are damaged or removed either simultaneously or shortly after the formation of the break in the internal elastic lamina and some underlying smooth muscle cells are damaged. Polymorphonuclear cells and monocytes are attracted to the site of injury. A repair process rapidly ensues including rapid regeneration of the endothelium and proliferation of smooth muscle cells in the underlying media and of some adventitial fibroblasts. This process results in the restitution of the endothelial monolayer and the laying down of one or several layers of longitudinal smooth muscle and collagen and elastic fibers in the subendothelial space. This demonstration of naturally occurring damage to fairly large areas of endothelium and the events which occur in the repair process is of interest in view of the "response-to-injury" theory of atherogenesis; observations are discussed in the light of previous studies performed on experimentally removed endothelium.
Collapse
|
38
|
Campbell JH, Popadynec L, Nestel PJ, Campbell GR. Lipid accumulation in arterial smooth muscle cells. Influence of phenotype. Atherosclerosis 1983; 47:279-95. [PMID: 6882501 DOI: 10.1016/0021-9150(83)90059-x] [Citation(s) in RCA: 54] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Isolated smooth muscle cells from the adult pig and rabbit aorta in primary culture undergo a spontaneous change in phenotype from a contractile to a synthetic state over 6-8 days, losing their capacity to contract and gaining the capacity to divide. The change in smooth muscle phenotype to the synthetic state is accompanied by distinct changes in the cells' ability to metabolize LDL, with the rate of degradation of 125I-labelled LDL decreasing to about one fifth of the level in contractile state cells. This does not appear to be due to changes in the number or affinity of LDL receptors since saturable binding of LDL is unaltered. The specific activities of the lysosomal enzymes acid phosphatase and N-acetyl-beta-glucosaminidase increase with change to the synthetic state as do cytochrome c oxidase (mitochondria) and NADPH-dependent cytochrome c reductase (endoplasmic reticulum). In contrast there is a slight but not significant decrease in the specific activity of the lysosomal enzyme acid cholesteryl esterase of rabbit smooth muscle cells and a significant decrease in the activity of pig cells with change in phenotype to the synthetic state. Significantly more [3H]cholesteryl oleate is recovered in synthetic state than in contractile state cells following incubation with 20 micrograms/ml unlabelled LDL and [3H]sodium oleate. Morphologically there is no difference in the number of lipid droplets in contractile and synthetic state cells after incubation in 5% normolipemic serum, but in cells grown in 10% hyperlipemic serum for 4 days synthetic state cells become almost completely filled with lipid droplets while contractile state cells are unaffected. Lipid accumulation also occurs selectively in vivo in synthetic as compared with contractile state smooth muscle cells within intimal fibromuscular thickenings induced by de-endothelialization of the carotid artery of cholesterol-fed rabbits. We suggest that accumulation of lipid in smooth muscle cells of atherosclerotic plaques is related to reduced catabolism of LDL following smooth muscle phenotypic change from the contractile to synthetic state.
Collapse
|
39
|
Campbell GR, Chamley-Campbell JH. Invited review: the cellular pathobiology of atherosclerosis. Pathology 1981; 13:423-40. [PMID: 6458011 DOI: 10.3109/00313028109059061] [Citation(s) in RCA: 67] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
|