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Bruijn LE, van den Akker BEWM, van Rhijn CM, Hamming JF, Lindeman JHN. Extreme Diversity of the Human Vascular Mesenchymal Cell Landscape. J Am Heart Assoc 2020; 9:e017094. [PMID: 33190596 PMCID: PMC7763765 DOI: 10.1161/jaha.120.017094] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/27/2020] [Accepted: 10/05/2020] [Indexed: 12/17/2022]
Abstract
Background Human mesenchymal cells are culprit factors in vascular (patho)physiology and are hallmarked by phenotypic and functional heterogeneity. At present, they are subdivided by classic umbrella terms, such as "fibroblasts," "myofibroblasts," "smooth muscle cells," "fibrocytes," "mesangial cells," and "pericytes." However, a discriminative marker-based subclassification has to date not been established. Methods and Results As a first effort toward a classification scheme, a systematic literature search was performed to identify the most commonly used phenotypical and functional protein markers for characterizing and classifying vascular mesenchymal cell subpopulation(s). We next applied immunohistochemistry and immunofluorescence to inventory the expression pattern of identified markers on human aorta specimens representing early, intermediate, and end stages of human atherosclerotic disease. Included markers comprise markers for mesenchymal lineage (vimentin, FSP-1 [fibroblast-specific protein-1]/S100A4, cluster of differentiation (CD) 90/thymocyte differentiation antigen 1, and FAP [fibroblast activation protein]), contractile/non-contractile phenotype (α-smooth muscle actin, smooth muscle myosin heavy chain, and nonmuscle myosin heavy chain), and auxiliary contractile markers (h1-Calponin, h-Caldesmon, Desmin, SM22α [smooth muscle protein 22α], non-muscle myosin heavy chain, smooth muscle myosin heavy chain, Smoothelin-B, α-Tropomyosin, and Telokin) or adhesion proteins (Paxillin and Vinculin). Vimentin classified as the most inclusive lineage marker. Subset markers did not separate along classic lines of smooth muscle cell, myofibroblast, or fibroblast, but showed clear temporal and spatial diversity. Strong indications were found for presence of stem cells/Endothelial-to-Mesenchymal cell Transition and fibrocytes in specific aspects of the human atherosclerotic process. Conclusions This systematic evaluation shows a highly diverse and dynamic landscape for the human vascular mesenchymal cell population that is not captured by the classic nomenclature. Our observations stress the need for a consensus multiparameter subclass designation along the lines of the cluster of differentiation classification for leucocytes.
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Affiliation(s)
- Laura E. Bruijn
- Division of Vascular SurgeryDepartment of SurgeryLeiden University Medical CenterLeidenthe Netherlands
| | | | - Connie M. van Rhijn
- Division of Vascular SurgeryDepartment of SurgeryLeiden University Medical CenterLeidenthe Netherlands
| | - Jaap F. Hamming
- Division of Vascular SurgeryDepartment of SurgeryLeiden University Medical CenterLeidenthe Netherlands
| | - Jan H. N. Lindeman
- Division of Vascular SurgeryDepartment of SurgeryLeiden University Medical CenterLeidenthe Netherlands
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Huang L, Li L, Yang T, Li W, Song L, Meng X, Gu Q, Xiong C, He J. Transgelin as a potential target in the reversibility of pulmonary arterial hypertension secondary to congenital heart disease. J Cell Mol Med 2018; 22:6249-6261. [PMID: 30338626 PMCID: PMC6237561 DOI: 10.1111/jcmm.13912] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2018] [Revised: 08/13/2018] [Accepted: 08/20/2018] [Indexed: 12/21/2022] Open
Abstract
BACKGROUND The reversibility of pulmonary arterial hypertension (PAH) in congenital heart disease (CHD) is of great importance for the operability of CHD. Proteomics analysis found that transgelin was significantly up-regulated in the lung tissue of CHD-PAH patients, especially in the irreversible group. However, how exactly it participated in CHD-PAH development is unknown. METHODS Immunohistochemical staining and Western blot were performed for further qualitative and quantitative analysis of transgelin in the lung tissues of CHD-PAH patients. The mechanism of transgelin in CHD-PAH development was explored in vitro. Primary human pulmonary arterial smooth muscle cells (hPASMCs) were cultured and infected with TAGLN siRNA or TAGLN lentiviral vector. Cell morphologic change (Coomassie Brilliant Blue staining), proliferation (cell count and EdU assay), apoptosis (terminal deoxyribonucleotidyl transferase mediated dUTP nick end labeling assay and Annexin-V flow cytometry) and migration (transwell) were evaluated following the cell treatment. The mRNA and protein expression levels were detected in real-time PCR and Western blot. RESULTS In line with the proteomic findings, transgelin was obviously expressed in PASMC of the middle pulmonary arterioles, especially in the irreversible PAH group. Also, transgelin expression showed positive relation with pathological grading. Experiment in vitro demonstrated that transgelin overexpression promoted PASMC proliferation and migration, strengthened cytoskeleton and was accompanied by increased expression of synthetic phenotype markers (osteopontin, proliferating cell nuclear antigen) and anti-apoptotic protein (bcl-2). On the other hand, suppression of transgelin expression activated PASMC apoptosis, reducing cell proliferation and migration. CONCLUSIONS Transgelin may be a potential target in the development of irreversible CHD-PAH through inducing PASMC phenotype change, proliferation, migration and reducing cell apoptosis.
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Affiliation(s)
- Li Huang
- Center of Pulmonary Vascular DiseaseState Key Laboratory of Cardiovascular DiseaseFuwai HospitalNational Center for Cardiovascular DiseasesChinese Academy of Medical Sciences and Peking Union Medical CollegeBeijingChina
| | - Li Li
- Department of PathologyState Key Laboratory of Cardiovascular DiseaseFuwai HospitalNational Center for Cardiovascular DiseasesChinese Academy of Medical Sciences and Peking Union Medical CollegeBeijingChina
| | - Tao Yang
- Center of Pulmonary Vascular DiseaseState Key Laboratory of Cardiovascular DiseaseFuwai HospitalNational Center for Cardiovascular DiseasesChinese Academy of Medical Sciences and Peking Union Medical CollegeBeijingChina
| | - Wen Li
- Center of Pulmonary Vascular DiseaseState Key Laboratory of Cardiovascular DiseaseFuwai HospitalNational Center for Cardiovascular DiseasesChinese Academy of Medical Sciences and Peking Union Medical CollegeBeijingChina
| | - Li Song
- State Key Laboratory of Cardiovascular DiseaseFuwai HospitalNational Center for Cardiovascular DiseasesChinese Academy of Medical Sciences and Peking Union Medical CollegeBeijingChina
| | - Xianmin Meng
- State Key Laboratory of Cardiovascular DiseaseFuwai HospitalNational Center for Cardiovascular DiseasesChinese Academy of Medical Sciences and Peking Union Medical CollegeBeijingChina
| | - Qing Gu
- Center of Pulmonary Vascular DiseaseState Key Laboratory of Cardiovascular DiseaseFuwai HospitalNational Center for Cardiovascular DiseasesChinese Academy of Medical Sciences and Peking Union Medical CollegeBeijingChina
| | - Changming Xiong
- Center of Pulmonary Vascular DiseaseState Key Laboratory of Cardiovascular DiseaseFuwai HospitalNational Center for Cardiovascular DiseasesChinese Academy of Medical Sciences and Peking Union Medical CollegeBeijingChina
| | - Jianguo He
- Center of Pulmonary Vascular DiseaseState Key Laboratory of Cardiovascular DiseaseFuwai HospitalNational Center for Cardiovascular DiseasesChinese Academy of Medical Sciences and Peking Union Medical CollegeBeijingChina
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3
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Abstract
Following its initial description over a century ago, pulmonary arterial hypertension (PAH) continues to challenge researchers committed to understanding its pathobiology and finding a cure. The last two decades have seen major developments in our understanding of the genetics and molecular basis of PAH that drive cells within the pulmonary vascular wall to produce obstructive vascular lesions; presently, the field of PAH research has taken numerous approaches to dissect the complex amalgam of genetic, molecular and inflammatory pathways that interact to initiate and drive disease progression. In this review, we discuss the current understanding of PAH pathology and the role that genetic factors and environmental influences share in the development of vascular lesions and abnormal cell function. We also discuss how animal models can assist in elucidating gene function and the study of novel therapeutics, while at the same time addressing the limitations of the most commonly used rodent models. Novel experimental approaches based on application of next generation sequencing, bioinformatics and epigenetics research are also discussed as these are now being actively used to facilitate the discovery of novel gene mutations and mechanisms that regulate gene expression in PAH. Finally, we touch on recent discoveries concerning the role of inflammation and immunity in PAH pathobiology and how they are being targeted with immunomodulatory agents. We conclude that the field of PAH research is actively expanding and the major challenge in the coming years is to develop a unified theory that incorporates genetic and mechanistic data to address viable areas for disease modifying drugs that can target key processes that regulate the evolution of vascular pathology of PAH.
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Chaabane C, Coen M, Bochaton-Piallat ML. Smooth muscle cell phenotypic switch: implications for foam cell formation. Curr Opin Lipidol 2014; 25:374-9. [PMID: 25110900 DOI: 10.1097/mol.0000000000000113] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
PURPOSE OF REVIEW It is well accepted that LDLs and its modified form oxidized-LDL (ox-LDL) play a major role in the development of atherosclerosis and foam cell formation. Whereas the majority of these cells have been demonstrated to be derived from macrophages, smooth muscle cells (SMCs) give rise to a significant number of foam cells as well. During atherosclerotic plaque formation, SMCs switch from a contractile to a synthetic phenotype. The contribution of this process to foam cell formation is still not well understood. RECENT FINDINGS It has been confirmed that a large proportion of foam cells in human atherosclerotic plaques and in experimental intimal thickening arise from SMCs. SMC-derived foam cells express receptors involved in ox-LDL uptake and HDL reverse transport. In-vitro studies show that treatment of SMCs with ox-LDL induces typical foam-cell formation; this process is associated with a transition of SMCs toward a synthetic phenotype. SUMMARY This review summarizes data regarding the phenotypic switch of arterial SMCs within atherosclerotic lesion and their contribution to intimal foam cell formation.
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Affiliation(s)
- Chiraz Chaabane
- Department of Pathology and Immunology, Faculty of Medicine, University of Geneva, Geneva, Switzerland
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Veith C, Zakrzewicz D, Dahal BK, Bálint Z, Murmann K, Wygrecka M, Seeger W, Schermuly RT, Weissmann N, Kwapiszewska G. Hypoxia- or PDGF-BB-dependent paxillin tyrosine phosphorylation in pulmonary hypertension is reversed by HIF-1α depletion or imatinib treatment. Thromb Haemost 2014; 112:1288-303. [PMID: 25231004 DOI: 10.1160/th13-12-1031] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2013] [Accepted: 07/10/2014] [Indexed: 12/27/2022]
Abstract
Chronic exposure to hypoxia induces a pronounced remodelling of the pulmonary vasculature leading to pulmonary hypertension (PH). The remodelling process also entails increased proliferation and decreased apoptosis of pulmonary arterial smooth muscle cells (PASMC), processes regulated by the cytoskeletal protein paxillin. In this study, we aimed to examine the molecular mechanisms leading to deregulation of paxillin in PH. We detected a time-dependent increase in paxillin tyrosine 31 (Y31) and 118 (Y118) phosphorylation following hypoxic exposure (1 % O2) or platelet-derived growth factor (PDGF)-BB stimulation of primary human PASMC. In addition, both, hypoxia- and PDGF-BB increased the nuclear localisation of phospho-paxillin Y31 as indicated by immunofluorescence staining in human PASMC. Elevated paxillin tyrosine phosphorylation in human PASMC was attenuated by hypoxia-inducible factor (HIF)-1α depletion or by treatment with the PDGF-BB receptor antagonist, imatinib. Moreover, we observed elevated paxillin Y31 and Y118 phosphorylation in the pulmonary vasculature of chronic hypoxic mice (21 days, 10 % O2) which was reversible by imatinib-treatment. PDGF-BB-dependent PASMC proliferation was regulated via the paxillin-Erk1/2-cyclin D1 pathway. In conclusion, we suggest paxillin up-regulation and phosphorylation as an important mechanism of vascular remodelling underlying pulmonary hypertension.
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Affiliation(s)
| | | | | | | | | | | | | | | | - N Weissmann
- Norbert Weissmann, Excellence Cluster Cardio-Pulmonary System (ECCPS), Justus-Liebig-University Giessen, Aulweg 130, 35392 Giessen, Germany, Tel.: +49 641 99 46000, Fax: +49 641 99 42419, E-mail:
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Townsley MI. Structure and composition of pulmonary arteries, capillaries, and veins. Compr Physiol 2013; 2:675-709. [PMID: 23606929 DOI: 10.1002/cphy.c100081] [Citation(s) in RCA: 166] [Impact Index Per Article: 15.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The pulmonary vasculature comprises three anatomic compartments connected in series: the arterial tree, an extensive capillary bed, and the venular tree. Although, in general, this vasculature is thin-walled, structure is nonetheless complex. Contributions to structure (and thus potentially to function) from cells other than endothelial and smooth muscle cells as well as those from the extracellular matrix should be considered. This review is multifaceted, bringing together information regarding (i) classification of pulmonary vessels, (ii) branching geometry in the pulmonary vascular tree, (iii) a quantitative view of structure based on morphometry of the vascular wall, (iv) the relationship of nerves, a variety of interstitial cells, matrix proteins, and striated myocytes to smooth muscle and endothelium in the vascular wall, (v) heterogeneity within cell populations and between vascular compartments, (vi) homo- and heterotypic cell-cell junctional complexes, and (vii) the relation of the pulmonary vasculature to that of airways. These issues for pulmonary vascular structure are compared, when data is available, across species from human to mouse and shrew. Data from studies utilizing vascular casting, light and electron microscopy, as well as models developed from those data, are discussed. Finally, the need for rigorous quantitative approaches to study of vascular structure in lung is highlighted.
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Affiliation(s)
- Mary I Townsley
- University of South Alabama, Department of Physiology, and Center for Lung Biology, Mobile, Alabama, USA.
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7
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Sluiter I, van der Horst I, van der Voorn P, Boerema-de Munck A, Buscop-van Kempen M, de Krijger R, Tibboel D, Reiss I, Rottier RJ. Premature differentiation of vascular smooth muscle cells in human congenital diaphragmatic hernia. Exp Mol Pathol 2012; 94:195-202. [PMID: 23018129 DOI: 10.1016/j.yexmp.2012.09.010] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2012] [Accepted: 09/15/2012] [Indexed: 10/27/2022]
Abstract
BACKGROUND Congenital diaphragmatic hernia (CDH) is a rare congenital anomaly characterized by the herniation of abdominal organs into the chest cavity. The high mortality and morbidity of CDH patients are primarily caused by the associated pulmonary hypertension (PH), characterized by the thickening of the vascular media and adventitia. The media consist of heterogeneous populations of vascular smooth muscle cells (VSMC), ranging from synthetic to the characteristic contractile cells. VSMCs are influenced by developmental and environmental cues and may play a role in the development of the structural changes observed in CDH patients. Therefore, we hypothesized that the distribution of the VSMC populations may already be different at the origin of CDH development. METHODOLOGY We analyzed the protein expression of specific markers associated with synthetic and contractile VSMC phenotypes in human lungs at different developmental stages. Next, we compared lungs of premature and term CDH patients, as well as patients with lung hypoplasia due to renal agenesis or PROM, with age-matched controls. RESULTS Synthetic and contractile VSMCs are distributed in a temporal and spatial specific pattern along the proximodistal axis of the lung. CDH patients have more abundant contractile VSMCs which are also more distally distributed. This different distribution pattern is already observed from 19 weeks of gestation onwards. CONCLUSION Our data suggest that the more extensive distribution of contractile VSMCs is associated with an early maturation of the pulmonary vasculature, contrasting the concept that CDH might be the result of delayed maturation of the epithelium.
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Affiliation(s)
- Ilona Sluiter
- Department of Pediatric Surgery, Erasmus MC Rotterdam, The Netherlands.
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Park C, Yan W, Ward SM, Hwang SJ, Wu Q, Hatton WJ, Park JK, Sanders KM, Ro S. MicroRNAs dynamically remodel gastrointestinal smooth muscle cells. PLoS One 2011; 6:e18628. [PMID: 21533178 PMCID: PMC3077387 DOI: 10.1371/journal.pone.0018628] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2010] [Accepted: 03/08/2011] [Indexed: 11/18/2022] Open
Abstract
Smooth muscle cells (SMCs) express a unique set of microRNAs (miRNAs) which regulate and maintain the differentiation state of SMCs. The goal of this study was to investigate the role of miRNAs during the development of gastrointestinal (GI) SMCs in a transgenic animal model. We generated SMC-specific Dicer null animals that express the reporter, green fluorescence protein, in a SMC-specific manner. SMC-specific knockout of Dicer prevented SMC miRNA biogenesis, causing dramatic changes in phenotype, function, and global gene expression in SMCs: the mutant mice developed severe dilation of the intestinal tract associated with the thinning and destruction of the smooth muscle (SM) layers; contractile motility in the mutant intestine was dramatically decreased; and SM contractile genes and transcriptional regulators were extensively down-regulated in the mutant SMCs. Profiling and bioinformatic analyses showed that SMC phenotype is regulated by a complex network of positive and negative feedback by SMC miRNAs, serum response factor (SRF), and other transcriptional factors. Taken together, our data suggest that SMC miRNAs are required for the development and survival of SMCs in the GI tract.
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Affiliation(s)
- Chanjae Park
- Department of Physiology and Cell Biology, University of Nevada School of Medicine, Reno, Nevada, United States of America
| | - Wei Yan
- Department of Physiology and Cell Biology, University of Nevada School of Medicine, Reno, Nevada, United States of America
| | - Sean M. Ward
- Department of Physiology and Cell Biology, University of Nevada School of Medicine, Reno, Nevada, United States of America
| | - Sung Jin Hwang
- Department of Physiology and Cell Biology, University of Nevada School of Medicine, Reno, Nevada, United States of America
| | - Qiuxia Wu
- Department of Physiology and Cell Biology, University of Nevada School of Medicine, Reno, Nevada, United States of America
| | - William J. Hatton
- Department of Physiology and Cell Biology, University of Nevada School of Medicine, Reno, Nevada, United States of America
| | - Jong Kun Park
- Division of Biological Science, Wonkwang University, Iksan, Chonbuk, South Korea
| | - Kenton M. Sanders
- Department of Physiology and Cell Biology, University of Nevada School of Medicine, Reno, Nevada, United States of America
| | - Seungil Ro
- Department of Physiology and Cell Biology, University of Nevada School of Medicine, Reno, Nevada, United States of America
- * E-mail:
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Aoshima D, Murata T, Hori M, Ozaki H. Time-dependent phenotypic and contractile changes of pulmonary artery in chronic hypoxia-induced pulmonary hypertension. J Pharmacol Sci 2009; 110:182-90. [PMID: 19498269 DOI: 10.1254/jphs.09059fp] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
Abstract
Phenotypic and contractile changes in pulmonary arterial smooth muscle cells (PASMCs) were examined in rats with pulmonary hypertension induced by hypoxia. Exposure to hypoxia induced pulmonary hypertension within 1-4 weeks. Staining with BrdU revealed that proliferative activities of PASMCs peaked at 1 week of hypoxic exposure, and then moderate proliferative activity was maintained for the next 2-4 weeks. The beta-actin/alpha-actin ratio also increased at 1-2 weeks of exposure to hypoxia. Absolute contractility of the pulmonary arterial ring continuously decreased during hypoxia, whereas the basal active tonus of the pulmonary artery increased at 1-3 weeks. Nicardipine, the ETA-receptor antagonis, CI-1034 and the rho-kinase inhibitor Y27632 partially inhibited the elevated active tonus. Endothelin-1 content in the pulmonary hypertensive lung was continuously increased during exposure to hypoxia. In conclusion, the hypoxia-induced proliferative activity of PASMCs comprised a transient phase followed by a sustained phase. The change in PASMCs from a contractile to a synthetic phenotype also correlated with proliferative activity, which subsequently decreased PASMC contractility. The continuous production of endothelin-1 upon hypoxic exposure might contribute to the increased basal tonus of the pulmonary arterial wall, which might subsequently increase pulmonic arterial pressure, resulting in accelerated pulmonary hypertension.
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Affiliation(s)
- Daigo Aoshima
- Department of Veterinary Pharmacology, Graduate School of Agriculture and Life Sciences, University of Tokyo, Tokyo, Japan
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10
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Liu J, Gao Y, Negash S, Longo LD, Raj JU. Long-term effects of prenatal hypoxia on endothelium-dependent relaxation responses in pulmonary arteries of adult sheep. Am J Physiol Lung Cell Mol Physiol 2009; 296:L547-54. [PMID: 19136582 DOI: 10.1152/ajplung.90333.2008] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Chronic hypoxia during the course of pregnancy is a common insult to the fetus. However, its long-term effect on the pulmonary vasculature in adulthood has not been described. In this study, the vasorelaxation responses of conduit pulmonary arteries in adult female sheep that were chronically hypoxic as fetuses and raised postnatally at sea level were investigated. Vessel tension studies revealed that endothelium-dependent relaxation responses were attenuated in pulmonary arteries from adult sheep that experienced prenatal hypoxia. Endothelial nitric oxide synthase (eNOS) protein expression was unchanged, but eNOS activity was significantly decreased in pulmonary arteries from prenatally hypoxic sheep. Protein expression of eNOS partners, caveolin-1, calmodulin, and heat shock protein 90 (Hsp90) did not change following prenatal hypoxia. However, the association between eNOS and caveolin-1, its inhibitory binding partner, was significantly increased, whereas association between eNOS and its stimulatory partners calmodulin and Hsp90 was greatly decreased. Furthermore, phosphorylation of Ser(1177) in eNOS decreased, whereas phosphorylation of Thr(495) increased, in the prenatally hypoxic pulmonary arteries, events that are related to eNOS activity. These data demonstrate that prenatal hypoxia results in persistent abnormalities in endothelium-dependent relaxation responses of pulmonary arteries in adult sheep due to decreased eNOS activity resulting from altered posttranslational regulation.
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Affiliation(s)
- Jie Liu
- Division of Neonatology, Harbor-University of California, Los Angeles Medical Center, Geffen School of Medicine at University of California, and Los Angeles Biomedical Research Institute, Los Angeles, California 90502, USA.
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St Hilaire C, Yang D, Schreiber BM, Ravid K. B-Myb regulates the A(2B) adenosine receptor in vascular smooth muscle cells. J Cell Biochem 2008; 103:1962-74. [PMID: 17979185 DOI: 10.1002/jcb.21586] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The A(2B) adenosine receptor (A(2B)AR) has been described to control various vascular functions, including inhibition of smooth muscle cell proliferation. Here, we sought to understand the regulation of A(2B)AR gene expression in aortic vascular smooth muscle cells (VSMCs), with a focus on the proliferation phase. Assays with A(2B)AR-beta-gal aortic VSMCs, in which the endogenous A(2B)AR gene promoter drives the expression of prokaryotic beta-galactosidase (beta-gal) instead of the endogenous A(2B)AR gene, show that beta-gal expression is upregulated when the cells are induced to exit from cell cycle arrest. Similarly, the level of A(2B)AR mRNA is upregulated in proliferating primary aortic VSMCs. In search of related mechanisms, it was noted that the A(2B)AR gene promoter contains several putative binding sites for the proliferation-inducing transcription factor, B-Myb. Using a clone of the 5' region upstream of the mouse A(2B)AR gene linked to a reporter gene, B-Myb site deletion mutants were generated. It was determined that B-Myb upregulates the A(2B)AR gene promoter, and specific promoter binding sites were identified as functional. In accordance, B-Myb also elevates endogenous A(2B)AR mRNA and receptor activity, and this activity decreases cell proliferation. Our data are novel in that they show that this proliferation-inhibiting A(2B)AR is itself an inducible receptor regulated by B-Myb.
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Affiliation(s)
- Cynthia St Hilaire
- Department of Biochemistry and Whitaker Cardiovascular Institute, Boston University School of Medicine, Boston, Massachusetts 02118, USA
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Madden JA, Dantuma MW, Sorokina EA, Weihrauch D, Kleinman JG. Telokin expression and the effect of hypoxia on its phosphorylation status in smooth muscle cells from small and large pulmonary arteries. Am J Physiol Lung Cell Mol Physiol 2008; 294:L1166-73. [PMID: 18375742 DOI: 10.1152/ajplung.00375.2007] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Small pulmonary arteries (SPA), <500 microm diameter of the cat, constrict when exposed to hypoxia, whereas larger arteries (large pulmonary arteries; LPA), >800 microm diameter, show little or no response. It is unknown why different contractile responses occur within the same vascular bed, but activator or repressor proteins within the smooth muscle cell (SMC) can modify myosin phosphatase and myosin light chain kinase (MLCK), thereby influencing the phosphorylation state of myosin light chain (MLC) and ultimately, contraction. Telokin, a protein with a sequence identical to the COOH-terminal domain of MLCK, is expressed in smooth muscle where in its phosphorylated state it inhibits myosin phosphatase, binds to unphosphorylated myosin, and helps maintain smooth muscle relaxation. We measured telokin mRNA and telokin protein in smooth muscle from different diameter feline pulmonary arteries and sought to determine whether changes in the phosphorylation status of telokin and MLC occurred during hypoxia. In pulmonary arteries, telokin expression varied inversely with artery diameter, but cerebral arteries showed neither telokin protein nor telokin mRNA. Although telokin and MLC were distributed uniformly throughout the SPA muscle cell cytoplasm, they were not colocalized. During hypoxia, telokin dephosphorylated, and MLC became increasingly phosphorylated in SPA SMC, whereas in LPA SMC there was no change in either telokin or MLC phosphorylation. When LPA SMC were exposed to phenylephrine, MLC phosphorylation increased with no change in telokin phosphorylation. These results suggest that in SPA, phosphorylated telokin may help maintain relaxation under unstimulated conditions, whereas in LPA, telokin's function remains undetermined.
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Affiliation(s)
- Jane A Madden
- Department of Neurology, Zablocki Veterans Affairs Medical Center, Milwaukee, Wisconsin 53295, USA.
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Abstract
Smooth muscles develop isometric force over a very wide range of cell lengths. The molecular mechanisms of this phenomenon are undefined, but are described as reflecting "mechanical plasticity" of smooth muscle cells. Plasticity is defined here as a persistent change in cell structure or function in response to a change in the environment. Important environmental stimuli that trigger muscle plasticity include chemical (e.g., neurotransmitters, autacoids, and cytokines) and external mechanical signals (e.g., applied stress and strain). Both kinds of signals are probably transduced by ionic and protein kinase signaling cascades to alter gene expression patterns and changes in the cytoskeleton and contractile system. Defining the signaling mechanisms and effector proteins mediating phenotypic and mechanical plasticity of smooth muscles is a major goal in muscle cell biology. Some of the signaling cascades likely to be important include calcium-dependent protein kinases, small GTPases (Rho, Rac, cdc42), Rho kinase, protein kinase C (PKC), Src family tyrosine kinases, mitogen-activated protein (MAP) kinases, and p21 activated protein kinases (PAK). There are many potential targets for these signaling cascades including nuclear processes, metabolic pathways, and structural components of the cytoskeleton. There is growing appreciation of the dynamic nature of the actin cytoskeleton in smooth muscles and the necessity for actin remodeling to occur during contraction. The actin cytoskeleton serves many functions that are probably critical for muscle plasticity including generation and transmission of force vectors, determination of cell shape, and assembly of signal transduction machinery. Evidence is presented showing that actin filaments are dynamic and that actin-associated proteins comprising the contractile element and actin attachment sites are necessary for smooth muscle contraction.Key words: integrin, muscle mechanics, paxillin, Rho, HSP27.
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Affiliation(s)
- William T Gerthoffer
- Department of Pharmacology, University of Nevada School of Medicine, Reno, NV 89557-0270, USA.
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Abstract
Persistent pulmonary hypertension of the newborn (PPHN), among the most rapidly progressive and potentially fatal of vasculopathies, is a disorder of vascular transition from fetal to neonatal circulation, manifesting as hypoxemic respiratory failure. PPHN represents a common pathway of vascular injury activated by numerous perinatal stresses: hypoxia, hypoglycemia, cold stress, sepsis, and direct lung injury. As with other multifactorial diseases, a single inciting event may be augmented by multiple concurrent/subsequent phenomena that result in differing courses of disease progression. I review the various mechanisms of vascular injury involved in neonatal pulmonary hypertension: endothelial dysfunction, inflammation, hypoxia, and mechanical strain, in the context of downstream effects on pulmonary vascular endothelial-myocyte interactions and myocyte phenotypic plasticity.
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Affiliation(s)
- S Dakshinamurti
- Department of Pediatrics, University of Manitoba, Manitoba Institute of Child Health, Winnipeg, Canada.
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Mulvihill ER, Jaeger J, Sengupta R, Ruzzo WL, Reimer C, Lukito S, Schwartz SM. Atherosclerotic Plaque Smooth Muscle Cells Have a Distinct Phenotype. Arterioscler Thromb Vasc Biol 2004; 24:1283-9. [PMID: 15142862 DOI: 10.1161/01.atv.0000132401.12275.0c] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Objective—
The present study addresses the question, “Are plaque smooth muscles cells (SMCs) genetically distinct from medial SMCs as reflected by the ability to maintain a distinctive expression phenotype in vitro?”
Methods and Results—
Multiple cell strains were developed from carotid endarcterectomy specimens, and quadruplicate array hybridizations were completed for each sample. A new normalization protocol was developed and used to analyze the data. Permutation analysis suggests that most of the significant differences in expression could not have occurred by chance. A broad pattern of significant expression differences, consisting of almost 5% of the genes probed, was detected. Quantitative polymerase chain reaction (QPCR) confirmation was found in 70% of a subset of genes selected for validation.
Conclusions—
The SMC cultures were nearly indistinguishable by morphological features, population doubling time, and sensitivity to cell death induced by Fas cross-linking. Surprisingly, array expression analysis identified differences so extensive that we conclude that plaque and medial SMCs are distinctly different SMC cell types.
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Affiliation(s)
- Eileen R Mulvihill
- Department of Pathology, University of Washington, Box 357335, Seattle, Wash 98195-7335, USA.
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16
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Rosenhek R, Korschineck I, Gharehbaghi-Schnell E, Jakowitsch J, Bonderman D, Huber K, Czerny M, Schleef RR, Maurer G, Lang IM. Fibrinolytic balance of the arterial wall: pulmonary artery displays increased fibrinolytic potential compared with aorta. J Transl Med 2003; 83:871-6. [PMID: 12808122 DOI: 10.1097/01.lab.0000073127.46392.9d] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
Classic pulmonary thromboembolism research has documented that large pulmonary thromboemboli lyse spontaneously, suggesting potent fibrinolytic activity in human pulmonary artery (Pa). This concept conflicts with published animal studies in which the proximal Pa was reported to be devoid of tissue plasminogen activator (t-PA) expression. The current study used in situ hybridization protocols to demonstrate t-PA expression in samples of human main Pa (n = 30). Real-time PCR was used to demonstrate quantitatively that the levels of t-PA transcripts were higher than those of its primary regulator [ie, plasminogen activator-inhibitor 1 (PAI-1)] in the Pa samples. Immunologic and functional assays extended these observations by demonstrating that levels of t-PA antigen were higher than PAI-1 antigen, which resulted in the detection of free t-PA activity. This contrasted with the fibrinolytic balance of matched samples of aorta (n = 6) in which PAI-1 transcripts and antigen values were higher than the corresponding t-PA values, and only M(r) 110 kDa t-PA-PAI-1 complexes could be detected in functional assays. To assess the relative fibrinolytic contribution of the endothelial cell layer, Pa endothelial cells and aortic endothelial cells were scraped and propagated in culture for 20 +/- 6 days. Pa endothelial cell-conditioned media revealed increased t-PA/PAI-1 antigen ratios. Taken together, our data indicate that the balance between t-PA and PAI-1 is shifted in human main Pa to favor net PA activity.
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Affiliation(s)
- Raphael Rosenhek
- Department of Cardiology, University of Vienna, and the Ludwig Boltzmann Institute for Cardiovascular Research, Vienna, Austria
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17
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Stevens T. Bronchial endothelial cell phenotypes and the form:function relationship. Am J Physiol Lung Cell Mol Physiol 2002; 283:L518-9. [PMID: 12169569 DOI: 10.1152/ajplung.00103.2002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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18
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Scholfield CN, Curtis TM. Heterogeneity in cytosolic calcium regulation among different microvascular smooth muscle cells of the rat retina. Microvasc Res 2000; 59:233-42. [PMID: 10684729 DOI: 10.1006/mvre.1999.2227] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Rat retinae were dissociated to yield intact microvessels 7 to 42 microm in diameter. These were loaded with fura-2 AM and single fragments anchored down in a recording bath. Intracellular Ca(2+) levels from 20- to 30-microm sections of vessel were estimated by microfluorimetry. The vessels studied were identified as metarterioles and arterioles. Only the microvascular smooth muscle cells loaded with fura-2 AM and changes in the fluorescence signal were confined to these cells: Endothelial cells did not make any contribution to the fluorescence signal nor did they contribute to the actions of the drugs. Caffeine (10 mM) or elevated K(+) (100 mM) produced a transient rise in cell Ca(2+) in the larger vessels (diameters >18 microm) but had no effect on smaller vessels (diameters <18 microm). Rises in cell Ca(2+) were accompanied by a rapid ( approximately 2 s to peak) contraction followed by relaxation. Caffeine and K(+) responses were blocked by ryanodine (10 microM) and nifedipine (1 microM), respectively. In all the vessels tested, vasopressin (arginine, 10 nM) elicited a transient increase in cell Ca(2+) and a constriction, irrespective of the diameter of the vessel. All vessels tested also responded to endothelin-1 (1-10 nM) through an Et(A) receptor to produce a transient rise in cell Ca(2+) followed by a plateau phase of elevated Ca(2+) and a constriction. In contrast to the transient effects of vasopressin, caffeine, and K(+), the cell Ca(2+) remained elevated (>30 min) on washing out the endothelin and the vessel failed to relax. These results demonstrate heterogeneity between smaller and larger retinal vessels with regard to Ca(2+) mobilisation and homogeneity with respect to the actions of vasoactive peptides.
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MESH Headings
- Animals
- Arginine Vasopressin/pharmacology
- Arterioles/metabolism
- Caffeine/pharmacology
- Calcium/metabolism
- Calcium Channels, L-Type/drug effects
- Calcium Channels, L-Type/metabolism
- Female
- Ion Transport
- Male
- Microcirculation
- Muscle, Smooth, Vascular/cytology
- Muscle, Smooth, Vascular/drug effects
- Muscle, Smooth, Vascular/metabolism
- Potassium/pharmacology
- Rats
- Rats, Sprague-Dawley
- Receptor, Endothelin A
- Receptors, Endothelin/drug effects
- Retinal Artery/metabolism
- Ryanodine/pharmacology
- Ryanodine Receptor Calcium Release Channel/drug effects
- Ryanodine Receptor Calcium Release Channel/metabolism
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Affiliation(s)
- C N Scholfield
- Smooth muscle group, Department of Physiology, Queens University, 97, Lisburn Road, Belfast, BT9 7BL, United Kingdom.
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