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Vitamin A as a Transcriptional Regulator of Cardiovascular Disease. HEARTS 2020. [DOI: 10.3390/hearts1020013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Vitamin A is a micronutrient and signaling molecule that regulates transcription, cellular differentiation, and organ homeostasis. Additionally, metabolites of Vitamin A are utilized as differentiation agents in the treatment of hematological cancers and skin disorders, necessitating further study into the effects of both nutrient deficiency and the exogenous delivery of Vitamin A and its metabolites on cardiovascular phenotypes. Though vitamin A/retinoids are well-known regulators of cardiac formation, recent evidence has emerged that supports their role as regulators of cardiac regeneration, postnatal cardiac function, and cardiovascular disease progression. We here review findings from genetic and pharmacological studies describing the regulation of both myocyte- and vascular-driven cardiac phenotypes by vitamin A signaling. We identify the relationship between retinoids and maladaptive processes during the pathological hypertrophy of the heart, with a focus on the activation of neurohormonal signaling and fetal transcription factors (Gata4, Tbx5). Finally, we assess how this information might be leveraged to develop novel therapeutic avenues.
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Kelley MD, Phomakay R, Lee M, Niedzwiedz V, Mayo R. Retinoic acid receptor gamma impacts cellular adhesion, Alpha5Beta1 integrin expression and proliferation in K562 cells. PLoS One 2017; 12:e0178116. [PMID: 28552962 PMCID: PMC5446131 DOI: 10.1371/journal.pone.0178116] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2017] [Accepted: 05/07/2017] [Indexed: 12/30/2022] Open
Abstract
The interplay between cellular adhesion and proliferation is complex; however, integrins, particularly the α5β1 subset, play a pivotal role in orchestrating critical cellular signals that culminate in cellular adhesion and growth. Retinoids modify the expression of a variety of adhesive/proliferative signaling proteins including α5β1 integrins; however, the role of specific retinoic acid receptors involved in these processes has not been elucidated. In this study, the effect of all-trans-retinoic acid receptor (RAR) agonists on K562 cellular adhesion, proliferation, and α5β1 integrin cell surface expression was investigated. RARγ agonist exposure increased K562 cellular adhesion to RGD containing extracellular matrix proteins fibronectin and FN-120 in a time- and concentration dependent manner, while RARα or RARβ agonist treatment had no effect on cellular adhesion. Due to the novel RARγ- dependent cellular adhesion response exhibited by K562 cells, we examined α5 and β1 integrin subunit expression when K562 cells were exposed to retinoid agonists or vehicle for 24, 48, 72 or 96 hours. Our data demonstrates no differences in K562 cell surface expression of the α5 integrin subunit when cells were exposed to RARα, RARβ, or RARγ agonists for all time points tested. In contrast, RARγ agonist exposure resulted in an increase in cell surface β1 integrin subunit expression within 48 hours that was sustained at 72 and 96 hours. Finally, we demonstrate that while exposure to RARα or RARβ agonists have no effect on K562 cellular proliferation, the RARγ agonist significantly dampens K562 cellular proliferation levels in a time- and concentration- dependent manner. Our study is the first to report that treatment with a RARγ specific agonist augments cellular adhesion to α5β1 integrin substrates, increases cell surface levels of the β1 integrin subunit, and dampens cellular proliferation in a time and concentration dependent manner in a human erythroleukemia cell line.
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Affiliation(s)
- Melissa D. Kelley
- Department of Chemistry and Biochemistry, University of Central Arkansas, Conway, Arkansas, United States of America
| | - Raynin Phomakay
- Department of Chemistry and Biochemistry, University of Central Arkansas, Conway, Arkansas, United States of America
| | - Madison Lee
- Department of Chemistry and Biochemistry, University of Central Arkansas, Conway, Arkansas, United States of America
| | - Victoria Niedzwiedz
- Department of Chemistry and Biochemistry, University of Central Arkansas, Conway, Arkansas, United States of America
| | - Rachel Mayo
- Department of Chemistry and Biochemistry, University of Central Arkansas, Conway, Arkansas, United States of America
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Whelan JT, Wang L, Chen J, Metts ME, Nasser TA, McGoldrick LJ, Bridges LC. Retinoids induce integrin-independent lymphocyte adhesion through RAR-α nuclear receptor activity. Biochem Biophys Res Commun 2014; 454:537-42. [PMID: 25450689 DOI: 10.1016/j.bbrc.2014.10.120] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2014] [Accepted: 10/24/2014] [Indexed: 11/28/2022]
Abstract
Oxidative metabolites of vitamin A, in particular all-trans-retinoic acid (atRA), have emerged as key factors in immunity by specifying the localization of immune cells to the gut. Although it is appreciated that isomers of retinoic acid activate the retinoic acid receptor (RAR) and retinoid X receptor (RXR) family of nuclear receptors to elicit cellular changes, the molecular details of retinoic acid action remain poorly defined in immune processes. Here we employ a battery of agonists and antagonists to delineate the specific nuclear receptors utilized by retinoids to evoke lymphocyte cell adhesion to ADAM (adisintegrin and metalloprotease) protein family members. We report that RAR agonism is sufficient to promote immune cell adhesion in both immortal and primary immune cells. Interestingly, adhesion occurs independent of integrin function, and mutant studies demonstrate that atRA-induced adhesion to ADAM members required a distinct binding interface(s) as compared to integrin recognition. Anti-inflammatory corticosteroids as well as 1,25-(OH)2D3, a vitamin D metabolite that prompts immune cell trafficking to the skin, potently inhibited the observed adhesion. Finally, our data establish that induced adhesion was specifically attributable to the RAR-α receptor isotype. The current study provides novel molecular resolution as to which nuclear receptors transduce retinoid exposure into immune cell adhesion.
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Affiliation(s)
- Jarrett T Whelan
- Department of Biochemistry and Molecular Biology, The Brody School of Medicine at East Carolina University, Greenville, NC 27834, United States
| | - Lei Wang
- Department of Biochemistry and Molecular Biology, The Brody School of Medicine at East Carolina University, Greenville, NC 27834, United States
| | - Jianming Chen
- Department of Biochemistry and Molecular Biology, The Brody School of Medicine at East Carolina University, Greenville, NC 27834, United States
| | - Meagan E Metts
- Department of Biochemistry and Molecular Biology, The Brody School of Medicine at East Carolina University, Greenville, NC 27834, United States
| | - Taj A Nasser
- Department of Biochemistry and Molecular Biology, The Brody School of Medicine at East Carolina University, Greenville, NC 27834, United States
| | - Liam J McGoldrick
- Department of Biochemistry and Molecular Biology, The Brody School of Medicine at East Carolina University, Greenville, NC 27834, United States
| | - Lance C Bridges
- Department of Biochemistry and Molecular Biology, The Brody School of Medicine at East Carolina University, Greenville, NC 27834, United States; East Carolina Diabetes and Obesity Institute, The Brody School of Medicine at East Carolina University, Greenville, NC 27834, United States.
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Hoffmann J, Wilhelm J, Marsh LM, Ghanim B, Klepetko W, Kovacs G, Olschewski H, Olschewski A, Kwapiszewska G. Distinct differences in gene expression patterns in pulmonary arteries of patients with chronic obstructive pulmonary disease and idiopathic pulmonary fibrosis with pulmonary hypertension. Am J Respir Crit Care Med 2014; 190:98-111. [PMID: 24918967 DOI: 10.1164/rccm.201401-0037oc] [Citation(s) in RCA: 73] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
RATIONALE The development of pulmonary hypertension (PH) in patients with idiopathic pulmonary fibrosis (IPF) or chronic obstructive pulmonary disease (COPD) is associated with increased morbidity. OBJECTIVES To elucidate whether vascular remodeling in a well-characterized PH-COPD and PH-IPF patient cohort results from similar or divergent molecular changes. METHODS Vascular remodeling of donor, PH-COPD, and PH-IPF pulmonary arteries was assessed. Laser capture microdissected pulmonary artery profiles in combination with whole genome microarrays were performed. MEASUREMENTS AND MAIN RESULTS Pulmonary arteries from patients with COPD and IPF with PH exhibited remodeling of vascular layers and reduction of lumen area. Pathway analyses comparing normalized gene expression profiles obtained from patients with PH-IPF or PH-COPD revealed the retinol and extracellular matrix (ECM) receptor interaction to be the most perturbed processes. Within the ECM-receptor pathway, differential regulation of 5 out of the top 10 results (collagen, type III, α-1; tenascin C; collagen, type VI, α-3; thrombospondin 2; and von Willebrand factor) were verified by real-time polymerase chain reaction and immunohistochemical staining. CONCLUSIONS Despite clinical and histologic vascular remodeling in all patients with PH-COPD and PH-IPF, differential gene expression pattern was present in pulmonary artery profiles. Several genes involved in retinol metabolism and ECM receptor interaction enable discrimination of vascular remodeling in PH-IPF or PH-COPD. This suggests that pulmonary arterial remodeling in PH-COPD and PH-IPF is caused by different molecular mechanisms and may require specific therapeutic options.
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Affiliation(s)
- Julia Hoffmann
- 1 Ludwig Boltzmann Institute for Lung Vascular Research, Graz, Austria
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Shi QQ, Sun M, Zhang ZT, Zhang YN, Elsayed AK, Zhang L, Huang XM, Li BC. A screen of suitable inducers for germline differentiation of chicken embryonic stem cells. Anim Reprod Sci 2014; 147:74-85. [PMID: 24786547 DOI: 10.1016/j.anireprosci.2014.04.002] [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: 11/27/2013] [Revised: 03/26/2014] [Accepted: 04/06/2014] [Indexed: 11/28/2022]
Abstract
Differentiation of germ cells from embryonic stem cells in vitro could have great application for treating infertility and provide an excellent model for uncovering molecular mechanisms of germline generation. In this study, we aim to screen the suitable inducers that may prove the efficiency of driving chicken embryonic stem cells (ES cells) toward germ cells. The male ES cells were separeted into different groups: single retinoic acid (RA) treatment, co-cultured with sertoli cell feeder with RA induction, cultured on matrix proteins (fibronectin, laminin and collagen) with RA treatment, cultured on fibronectin with sertoli cell feeder and RA induction, and single bone morphogenetic protein 4 (BMP4) treatment. Quantitative RT-PCR and immunoourescence were performed to characterize the ES cells differentiation process. The results showed that spermatogonial stem cells (SSCs)-like were not detected in single RA and RA with collagen groups, but were observed in the other groups. The expression of ES specific genes (Nanog and Sox2) was decreased while SSCs marker genes (Dazl, Stra8, integrin α6, integrinβ1 and C-kit) was remarkably increased. The multiple comparsion results showed that the expression of SSCs marker genes in RA with sertoli cells group was significantly higher than the other groups(P<0.05). Collectively, our results suggested that chicken ES cells possess the potency to differentiate into SSCs-like cells in vitro through RA, matrix proteins, sertoli cells and BMP4 induction, of which co-cultured with sertoli cell feeder with RA induction was proved to be the best.
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Affiliation(s)
- Qing-Qing Shi
- College of Animal Science and Technology, Yangzhou University, Yangzhou 225009, China; Key Laboratory of Animal Breeding Reproduction and Molecular Design for Jiangsu Province, Yangzhou 225009, China.
| | - Min Sun
- College of Animal Science and Technology, Yangzhou University, Yangzhou 225009, China; Key Laboratory of Animal Breeding Reproduction and Molecular Design for Jiangsu Province, Yangzhou 225009, China.
| | - Zhen-Tao Zhang
- College of Animal Science and Technology, Yangzhou University, Yangzhou 225009, China; Key Laboratory of Animal Breeding Reproduction and Molecular Design for Jiangsu Province, Yangzhou 225009, China.
| | - Ya-Ni Zhang
- College of Animal Science and Technology, Yangzhou University, Yangzhou 225009, China; Key Laboratory of Animal Breeding Reproduction and Molecular Design for Jiangsu Province, Yangzhou 225009, China.
| | - Ahmed Kamel Elsayed
- College of Animal Science and Technology, Yangzhou University, Yangzhou 225009, China; Suez Canal University, Ismailia 41522, Egypt.
| | - Lei Zhang
- College of Animal Science and Technology, Yangzhou University, Yangzhou 225009, China; Key Laboratory of Animal Breeding Reproduction and Molecular Design for Jiangsu Province, Yangzhou 225009, China.
| | - Xiao-Mei Huang
- College of Animal Science and Technology, Yangzhou University, Yangzhou 225009, China; Key Laboratory of Animal Breeding Reproduction and Molecular Design for Jiangsu Province, Yangzhou 225009, China.
| | - Bi-Chun Li
- College of Animal Science and Technology, Yangzhou University, Yangzhou 225009, China; Key Laboratory of Animal Breeding Reproduction and Molecular Design for Jiangsu Province, Yangzhou 225009, China.
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Hanson AM, Gambill J, Phomakay V, Staten CT, Kelley MD. 9-cis-retinoic Acid and troglitazone impacts cellular adhesion, proliferation, and integrin expression in K562 cells. PLoS One 2014; 9:e93005. [PMID: 24671180 PMCID: PMC3966848 DOI: 10.1371/journal.pone.0093005] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2013] [Accepted: 02/27/2014] [Indexed: 11/19/2022] Open
Abstract
Retinoids are established pleiotropic regulators of both adaptive and innate immune responses. Recently, troglitazone, a PPAR gamma agonist, has been demonstrated to have anti-inflammatory effects. Separately, retinoids and troglitazone are implicated in immune related processes; however, their combinatory role in cellular adhesion and proliferation has not been well established. In this study, the effect of 9-cis-retinoic acid (9-cis-RA) and troglitazone on K562 cellular adhesion and proliferation was investigated. Troglitazone exposure decreased K562 cellular adhesion to RGD containing extracellular matrix proteins fibronectin, FN-120, and vitronectin in a concentration and time-dependent manner. In the presence of troglitazone, 9-cis-retinoic acid restores cellular adhesion to levels comparable to vehicle treatment alone on fibronectin, FN-120, and vitronectin substrates within 72 hours. Due to the prominent role of integrins in attachment to extracellular matrix proteins, we evaluated the level of integrin α5 subunit expression. Troglitazone treatment results in decrease in α5 subunit expression on the cell surface. In the presence of both agonists, cell surface α5 subunit expression was restored to levels comparable to vehicle treatment alone. Additionally, troglitazone and 9-cis-RA mediated cell adhesion was decreased in the presence of a function blocking integrin alpha 5 inhibitor. Further, through retinoid metabolic profiling and HPLC analysis, our study demonstrates that troglitazone augments retinoid availability in K562 cells. Finally, we demonstrate that troglitazone and 9-cis-retinoic acid synergistically dampen cellular proliferation in K562 cells. Our study is the first to report that the combination of troglitazone and 9-cis-retinoic acid restores cellular adhesion, alters retinoid availability, impacts integrin expression, and dampens cellular proliferation in K562 cells.
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Affiliation(s)
- Amanda M. Hanson
- Department of Chemistry and Biochemistry, University of Arizona, Tucson, Arizona, United States of America
| | - Jessica Gambill
- College of Medicine, University of Arkansas Medical Sciences, Little Rock, Arkansas, United States of America
| | - Venusa Phomakay
- College of Medicine, University of Arkansas Medical Sciences, Little Rock, Arkansas, United States of America
| | - C. Tyler Staten
- College of Pharmacy, Harding University, Searcy, Arkansas United States of America
| | - Melissa D. Kelley
- Department of Chemistry, University of Central Arkansas, Conway, Arkansas, United States of America
- * E-mail:
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Whelan JT, Chen J, Miller J, Morrow RL, Lingo JD, Merrell K, Shaikh SR, Bridges LC. 9-cis-retinoic acid promotes cell adhesion through integrin dependent and independent mechanisms across immune lineages. J Nutr Biochem 2012; 24:832-41. [PMID: 22925918 DOI: 10.1016/j.jnutbio.2012.05.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2012] [Revised: 04/30/2012] [Accepted: 05/02/2012] [Indexed: 12/13/2022]
Abstract
Retinoids are essential in the proper establishment and maintenance of immunity. Although retinoids are implicated in immune related processes, their role in immune cell adhesion has not been well established. In this study, the effect of 9-cis-retinoic acid (9-cis-RA) on human hematopoietic cell adhesion was investigated. 9-cis-RA treatment specifically induced cell adhesion of the human immune cell lines HuT-78, NB4, RPMI 8866 and U937. Due to the prominent role of integrin receptors in mediating immune cell adhesion, we sought to evaluate if cell adhesion was integrin-dependent. By employing a variety of integrin antagonist including function-blocking antibodies and EDTA, we establish that 9-cis-RA prompts immune cell adhesion through established integrin receptors in addition to a novel integrin-independent process. The novel integrin-independent adhesion required the presence of retinoid and was attenuated by treatment with synthetic corticosteroids. Finally, we demonstrate that 9-cis-RA treatment of primary murine B-cells induces ex vivo adhesion that persists in the absence of integrin function. Our study is the first to demonstrate that 9-cis-RA influences immune cell adhesion through at least two functionally distinct mechanisms.
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Affiliation(s)
- Jarrett T Whelan
- Department of Biochemistry and Molecular Biology, The Brody School of Medicine at East Carolina University, Greenville, NC 27834, USA
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Li P, Pashmforoush M, Sucov HM. Mesodermal retinoic acid signaling regulates endothelial cell coalescence in caudal pharyngeal arch artery vasculogenesis. Dev Biol 2011; 361:116-24. [PMID: 22040871 DOI: 10.1016/j.ydbio.2011.10.018] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2011] [Revised: 10/12/2011] [Accepted: 10/13/2011] [Indexed: 10/16/2022]
Abstract
Disruption of retinoic acid signaling causes a variety of pharyngeal arch artery and great vessel defects, as well as malformations in many other tissues, including those derived from the pharyngeal endoderm. Previous studies implied that arch artery defects in the context of defective RA signaling occur secondary to pharyngeal pouch segmentation defects, although this model has never been experimentally verified. In this study, we examined arch artery morphogenesis during mouse development, and the role of RA in this process. We show in normal embryos that the arch arteries form by vasculogenic differentiation of pharyngeal mesoderm. Using various genetic backgrounds and tissue-specific mutation approaches, we segregate pharyngeal arch artery and pharyngeal pouch defects in RA receptor mutants, and show that RA signal transduction only in pharyngeal mesoderm is required for arch artery formation. RA does not control pharyngeal mesodermal differentiation to endothelium, but instead promotes the aggregation of endothelial cells into nascent vessels. Expression of VE-cadherin was substantially reduced in RAR mutants, and this deficiency may underlie the arch artery defects. The consequences of disrupted mesodermal and endodermal RA signaling were restricted to the 4th and 6th arch arteries and to the 4th pharyngeal pouch, respectively, suggesting that different regulatory mechanisms control the formation of the more anterior arch arteries and pouches.
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Affiliation(s)
- Peng Li
- Broad Center for Regenerative Medicine and Stem Cell Research, University of Southern California Keck School of Medicine, 1425 San Pablo St., Los Angeles, CA 90033, USA
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Rhee EJ, Nallamshetty S, Plutzky J. Retinoid metabolism and its effects on the vasculature. Biochim Biophys Acta Mol Cell Biol Lipids 2011; 1821:230-40. [PMID: 21810483 DOI: 10.1016/j.bbalip.2011.07.001] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2011] [Revised: 06/15/2011] [Accepted: 07/06/2011] [Indexed: 12/16/2022]
Abstract
Retinoids, the metabolically-active structural derivatives of vitamin A, are critical signaling molecules in many fundamental biological processes including cell survival, proliferation and differentiation. Emerging evidence, both clinical and molecular, implicates retinoids in atherosclerosis and other vasculoproliferative disorders such as restenosis. Although the data from clinical trials examining effect of vitamin A and vitamin precursors on cardiac events have been contradictory, this data does suggest that retinoids do influence fundamental processes relevant to atherosclerosis. Preclinical animal model and cellular studies support these concepts. Retinoids exhibit complex effects on proliferation, growth, differentiation and migration of vascular smooth muscle cells (VSMC), including responses to injury and atherosclerosis. Retinoids also appear to exert important inhibitory effects on thrombosis and inflammatory responses relevant to atherogenesis. Recent studies suggest retinoids may also be involved in vascular calcification and endothelial function, for example, by modulating nitric oxide pathways. In addition, established retinoid effects on lipid metabolism and adipogenesis may indirectly influence inflammation and atherosclerosis. Collectively, these observations underscore the scope and complexity of retinoid effects relevant to vascular disease. Additional studies are needed to elucidate how context and metabolite-specific retinoid effects affect atherosclerosis. This article is part of a Special Issue entitled: Retinoid and Lipid Metabolism.
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Affiliation(s)
- Eun-Jung Rhee
- Cardiovascular Division, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
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Calì C, Marchaland J, Spagnuolo P, Gremion J, Bezzi P. Regulated exocytosis from astrocytes physiological and pathological related aspects. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2009; 85:261-93. [PMID: 19607976 DOI: 10.1016/s0074-7742(09)85020-4] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Astrocytes have traditionally been considered ancillary, satellite cells of the nervous system. However, it is a very recent acquisition that glial cells generate signaling loops which are integral to the brain circuitry and participate, interactively with neuronal networks, in the processing of information. Such a conceptual breakthrough makes this field of investigation one of the hottest in neuroscience, as it calls for a revision of past theories of brain function as well as for new strategies of experimental exploration of brain function. Glial cells are electrically not excitable, and it was only the use of optical recording techniques together with calcium sensitive dyes, that allowed the chemical excitability of glial cells to become apparent. Studies using these new techniques have shown for the first time that glial cells are activated by surrounding synaptic activity and translate neuronal signals into their own calcium code. Intracellular calcium concentration([Ca2+]i) elevations in glial cells have then shown to underlie spatial transfer of information in the glial network, accompanied by release of chemical transmitters (gliotransmitters) such as glutamate and back-signaling to neurons. As a consequence, optical imaging techniques applied to cell cultures or intact tissue have become a state-of-the-art technology for studying glial cell signaling. The molecular mechanisms leading to release of "gliotransmitters," especially glutamate, from glia are under debate. Accumulating evidence clearly indicates that astrocytes secrete numerous transmitters by Ca(2+)-dependent exocytosis. This review will discuss the mechanisms underlying the release of chemical transmitters from astrocytes with a particular emphasis to the regulated exocytosis processes.
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Affiliation(s)
- Corrado Calì
- Department of Cellular Biology and Morphology (DBCM), Faculty of Medicine, University of Lausanne, rue du Bugnon 9, 1005 Lausanne, Switzerland
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Ye X, Lotan R. Potential misinterpretation of data on differential gene expression in normal and malignant cells in vitro. BRIEFINGS IN FUNCTIONAL GENOMICS AND PROTEOMICS 2008; 7:322-6. [DOI: 10.1093/bfgp/eln021] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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12
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Bridges LC, Lingo JD, Grandon RA, Kelley MD. All-trans-Retinoic Acid Induces Integrin-Independent B-Cell Adhesion to ADAM Disintegrin Domains. Biochemistry 2008; 47:4544-51. [DOI: 10.1021/bi702447u] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Affiliation(s)
- Lance C. Bridges
- Department of Chemistry, University of Central Arkansas, Conway, Arkansas 72035
| | - Joshuah D. Lingo
- Department of Chemistry, University of Central Arkansas, Conway, Arkansas 72035
| | - Rachel A. Grandon
- Department of Chemistry, University of Central Arkansas, Conway, Arkansas 72035
| | - Melissa D. Kelley
- Department of Chemistry, University of Central Arkansas, Conway, Arkansas 72035
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13
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Vitamin A: a drug for prevention of restenosis/reocclusion after percutaneous coronary intervention? Clin Sci (Lond) 2008; 114:19-25. [PMID: 18047466 DOI: 10.1042/cs20070090] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The re-establishment of adequate blood flow in a vessel with a reduced lumen due to an atherosclerotic plaque by percutaneous vascular intervention is a well established procedure. However, the long-term outcome of such interventions is negatively influenced by the development of intimal hyperplasia/restenosis. Although extensively researched, this still represents a significant clinical problem. Retinoids, i.e. natural and synthetic derivates of vitamin A, represent a potential therapeutic compound, since they have been shown to influence the vast majority of processes that ultimately lead to reocclusion of the injured vessel. Retinoids exert their effects at the transcriptional level through their nuclear receptors. Targeting multiple processes, i.e. proliferation, migration, extracellular matrix composition and cell differentiation, as well as coagulation/fibrinolysis, should increase their future role in the prevention of restenosis. The purpose of this review is to summarize the diverse effects of retinoids on pathobiological and biological processes activated at sites of vascular injury with particular emphasis on intimal hyperplasia/restenosis after endovascular interventions.
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Druilhe A, Zahm JM, Benayoun L, El Mehdi D, Grandsaigne M, Dombret MC, Mosnier I, Feger B, Depondt J, Aubier M, Pretolani M. Epithelium expression and function of retinoid receptors in asthma. Am J Respir Cell Mol Biol 2007; 38:276-82. [PMID: 17884991 DOI: 10.1165/rcmb.2006-0453oc] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Abnormal epithelial repair to damage participates in airway remodeling in asthma by the paracrine regulation of mesenchymal cell functions. Retinoids control epithelial functions through nuclear retinoic acid receptor (RAR) and retinoid X receptor (RXR) activation, yet their expression and contribution to epithelial repair and to airway remodeling in asthma are unknown. We determined the plasma levels of retinol and the immunohistochemical expression of retinoid receptors in damaged and repaired bronchial epithelium from 9 control subjects, 10 subjects with intermittent asthma, 8 subjects with mild-to-moderate asthma, and 8 subjects with severe asthma. In addition, the effect of the retinoid receptor ligands, all-trans-retinoic acid, and 9-cis retinoic acid, on the synthesis of 38 factors potentially involved in epithelial repair and in airway remodeling was determined in human cultured airway epithelial cells and correlated with cell migration and proliferation. Circulating retinol was similar in the three patient groups. In contrast, the epithelial expression of RARgamma, RXRalpha, and RXRgamma was greater in subjects with severe asthma, as compared with patients with milder disease and to control subjects. Retinoid receptor expression correlated positively with the proportion of morphologically intact epithelium. In vitro, retinoids up-regulated the expression of the transcripts encoding transforming growth factor (TGF)-beta1, metalloproteinase-9, beta1-integrin, and hepatocyte growth factor receptor, and promoted wound repair and chemokinesis of human airway epithelial cells without altering proliferation. Cell treatment with an anti-TGF-beta1 monoclonal antibody partially reduced retinoid-induced effects. Persistent interaction between retinoids and some of their receptors, which are overexpressed by the bronchial epithelium of individuals with severe asthma, may contribute to an abnormal repair and to airway remodeling, partly through TGF-beta1 production.
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Affiliation(s)
- Anne Druilhe
- Inserm Unité 700, Université Paris 7, Faculté de Médecine Denis Diderot, site Xavier Bichat, 16, rue Henri Huchard, 75018 Paris, France
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15
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Bozzo C, Sabbatini M, Tiberio R, Piffanelli V, Santoro C, Cannas M. Activation of caspase-8 triggers anoikis in human neuroblastoma cells. Neurosci Res 2006; 56:145-53. [PMID: 16872704 DOI: 10.1016/j.neures.2006.06.008] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2005] [Revised: 05/31/2006] [Accepted: 06/19/2006] [Indexed: 01/23/2023]
Abstract
Cells require appropriate interaction with extracellular matrix proteins mediated by integrins to grow, differentiate and survive. Many cell types including nervous cells undergo anoikis, a substrate-dependent apoptosis, when adhesion is impaired. Resistance of tumors to cytotoxic drugs is probably due to disturbed apoptosis programs. The proteolytic enzymes caspases are the main executioners of apoptosis. It was reported that caspase-8 expression is deficient in some neuroblastoma cells. We demonstrated that human neuroblastoma cell line SK-B-BE, differentiated with retinoic acid, expressed caspases 3, 8 and 9. Caspases 8 and 3, but not caspase-9 were activated in SK-N-BE cells cultured in suspension or on aspecific adhesive substrate. Cell positive to caspase-8 were classified into four stages, by morphometric and densitometric parameters. The use of the specific caspase-8 inhibitor Z-IETD-FMK dramatically reduced apoptosis, demonstrating that caspase-8 is the upstream initiator caspase during SK-N-BE cells anoikis. Among matrix proteins, type I collagen is the most effective and fibronectin the least in delaying anoikis. The activation of caspases 8 and 3 by unligated integrins was dependent on the state of neuronal differentiation, since the most differentiated cell was the most vulnerable to anoikis. These data show that activation of caspase-8 is specifically required to promote anoikis in SK-N-BE neuroblastoma cells.
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Affiliation(s)
- Chiarella Bozzo
- Department of Clinical and Experimental Medicine, University of Eastern Piedmont A. Avogadro, Novara, Italy.
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Dhanasekaran A, Al-Saghir R, Lopez B, Zhu D, Gutterman DD, Jacobs ER, Medhora M. Protective effects of epoxyeicosatrienoic acids on human endothelial cells from the pulmonary and coronary vasculature. Am J Physiol Heart Circ Physiol 2006; 291:H517-31. [PMID: 16617127 DOI: 10.1152/ajpheart.00953.2005] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Epoxyeicosatrienoic acids (EETs) are cytochrome P-450 (CYP) metabolites synthesized from the essential fatty acid arachidonic acid to generate four regioisomers, 14,15-, 11,12-, 8,9-, and 5,6-EET. Cultured human coronary artery endothelial cells (HCAECs) contain endogenous EETs that are increased by stimulation with physiological agonists such as bradykinin. Because EETs are known to modulate a number of vascular functions, including angiogenesis, we tested each of the four regioisomers to characterize their effects on survival and apoptosis of HCAECs and cultured human lung microvascular endothelial cells (HLMVECs). A single application of physiologically relevant concentration of 14,15-, 11,12-, and 8,9-EET but not 5,6-EET (0.75-300 nM) promoted concentration-dependent increase in cell survival of HLMVECs and HCAECs after removal of serum. The lipids also protected the same cells from death via the intrinsic, as well as extrinsic, pathways of apoptosis. EETs did not increase intracellular calcium concentration ([Ca2+]i) or phosphorylate mitogen-activated protein kinase p44/42 when applied to these cells, and their protective action was attenuated by the phosphotidylinositol-3 kinase inhibitor wortmannin (10 microM) but not the cyclooxygenase inhibitor indomethacin (20 microM). Our results demonstrate for the first time the capacity of EETs to enhance human endothelial cell survival by inhibiting both the intrinsic, as well as extrinsic, pathways of apoptosis, an important underlying mechanism that may promote angiogenesis and endothelial survival during atherosclerosis and related cardiovascular ailments.
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Affiliation(s)
- Anuradha Dhanasekaran
- Division of Pulmonary and Critical Care, Department of Medicine, Cardiovascular Center, Medical College of Wisconsin, Milwaukee, Wisconsin 53226, USA
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17
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Mey J. New therapeutic target for CNS injury? The role of retinoic acid signaling after nerve lesions. ACTA ACUST UNITED AC 2006; 66:757-79. [PMID: 16688771 DOI: 10.1002/neu.20238] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Experiments with sciatic nerve lesions and spinal cord contusion injury demonstrate that the retinoic acid (RA) signaling cascade is activated by these traumatic events. In both cases the RA-synthesizing enzyme is RALDH-2. In the PNS, lesions cause RA-induced gene transcription, intracellular translocation of retinoid receptors, and increased transcription of CRBP-I, CRABP-II, and retinoid receptors. The activation of RARbeta appears to be responsible for neurotrophic and neuritogenic effects of RA on dorsal root ganglia and embryonic spinal cord. While the physiological role of RA in the injured nervous system is still under investigation three domains of functions are suggested: (1) neuroprotection and support of axonal growth, (2) modulation of the inflammatory reaction by microglia/macrophages, and (3) regulation of glial differentiation. Few studies have been performed to support nerve regeneration with RA signals in vivo, but a large number of experiments with neuronal and glial cell cultures and spinal cord explants point to beneficial effects of RA, so that future therapeutic approaches will likely focus on the activation of RA signaling.
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Affiliation(s)
- Jörg Mey
- Institut für Biologie II, RWTH Aachen, Germany.
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Martinez-Lemus LA, Crow T, Davis MJ, Meininger GA. alphavbeta3- and alpha5beta1-integrin blockade inhibits myogenic constriction of skeletal muscle resistance arterioles. Am J Physiol Heart Circ Physiol 2005; 289:H322-9. [PMID: 15722407 DOI: 10.1152/ajpheart.00923.2003] [Citation(s) in RCA: 98] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
In isolated resistance arterioles with spontaneous tone, ligation of alpha4beta1- and alpha5beta1-integrins induces vasoconstriction whereas ligation of alphavbeta3-integrin induces vasodilation. However, whether integrins directly participate in myogenic constriction to pressure elevation is not known. To answer this question, isolated rat skeletal muscle arterioles were exposed to step increments in pressure in the absence or presence of peptides and function-blocking antibodies known to bind alpha4beta1-, alpha5beta1-, or alphavbeta3-integrins while vessel diameter was continually monitored. Myogenic constriction, as assessed by the ability of isolated arterioles to reduce their diameter in response to two consecutive increments in intraluminal pressure (90-110 and 110-130 cmH2O), was not affected by treatment with any of the control peptides (RAD, LEV), a control antibody (anti-rat major histocompatibility complex), an alpha4beta1-integrin-binding peptide (LDV), or an anti-alpha4-integrin antibody. In contrast, alpha5beta1-integrin blockade with either anti-alpha5- or anti-beta1-integrin antibody caused a significant inhibition of myogenic constriction. Also, both RGD peptide and anti-beta3-integrin antibody inhibited myogenic constriction. These results indicate that alpha5beta1- and alphavbeta3-integrins are necessary for myogenic constriction and further suggest that integrins are part of the mechanosensory apparatus responsible for the ability of vascular smooth muscle cells to detect and/or respond to changes in intraluminal pressure.
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Affiliation(s)
- Luis A Martinez-Lemus
- Cardiovascular Research Inst., Dept. of Medical Physiology, Texas A&M Univ. Health Science Center, 336 Reynolds Medical Bldg., College Station, TX 77843-1114, USA
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19
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Sabbatini M, Bozzo C, Castellucci M, Cannas M. Morphometric Quantification of Apoptotic Stages in Cell Culture. Cells Tissues Organs 2005; 178:139-45. [PMID: 15655331 DOI: 10.1159/000082244] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/04/2004] [Indexed: 12/16/2022] Open
Abstract
Apoptosis is an active process of self-destruction, whereby cells undergo physiological cell death. It occurs during development and regulation of tissue homeostasis or as a result of changes in environmental stimuli. Chromatin condensation and nuclear fragmentation, which are typical features of apoptotic nuclei, are usually quantified by fluorescent DNA dyes. The present study reports a reliable method to analyze morphological apoptotic stages in cultured cells, using light microscopy. We used the human neuroblastoma cell line SK-N-BE as a model to study apoptosis induced by inadequate cell-matrix interactions. Apoptosis was detected on cells cultured for different time intervals on polyHEMA, poly-L-lysine or collagen I. Quantitative morphometric and densitometric analysis after hematoxylin nuclear staining and caspase-3 immunocytochemistry, as markers of occurring apoptosis, were performed. Our method identifies different stages of caspase-3 activation and the subsequent DNA fragmentation and condensation. This experimental procedure enables us to detect slight differences in apoptosis progression by morphological analysis.
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Affiliation(s)
- Maurizio Sabbatini
- Department of Medical Science, Human Anatomy Laboratory, University of Eastern Piedmont A. Avogadro, via Solaroli 17, IT-28100 Novara, Italy
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Mey J, McCaffery P. Retinoic acid signaling in the nervous system of adult vertebrates. Neuroscientist 2005; 10:409-21. [PMID: 15359008 DOI: 10.1177/1073858404263520] [Citation(s) in RCA: 107] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The majority of the functions of vitamin A are carried out by its metabolite, retinoic acid (RA), a potent transcriptional activator acting through members of the nuclear receptor family of transcription factors. In the CNS, RA was first recognized to be essential for the control of patterning and differentiation in the developing embryo. It has recently come to light, however, that many of the same functions that RA directs in the embryo are involved in the regulation of plasticity and regeneration in the adult brain. The same intricate metabolic control system of synthetic and catabolic enzymes, combined with cytoplasmic binding proteins, is used in both embryo and adult to create regions of high and low RA to modulate gene transcription. This review summarizes some of the discoveries in the new field of retinoid neurobiology including its functions in neural plasticity and LTP in the hippocampus; its possible role in motor disorders such as Parkinson's disease, motoneuron disease, and Huntington's disease; its role in regeneration after sciatic nerve and spinal cord injury; and its possible involvement in psychiatric diseases such as depression.
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Affiliation(s)
- Jörg Mey
- Institut für Biologie II, Aachen, Germany.
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Swartz-Basile DA, Wang L, Tang Y, Pitt HA, Rubin DC, Levin MS. Vitamin A deficiency inhibits intestinal adaptation by modulating apoptosis, proliferation, and enterocyte migration. Am J Physiol Gastrointest Liver Physiol 2003; 285:G424-32. [PMID: 12711591 DOI: 10.1152/ajpgi.00524.2002] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
In a prior study, vitamin A-deficient rats subjected to submassive small bowel resections did not mount a normal intestinal adaptive response by 10 days postoperatively, although adaptive increases in crypt cell proliferation were not attenuated and there were no differences in apoptotic indexes. The present study was designed to address the mechanisms by which vitamin A status effects adaptation by analyzing proliferation, apoptosis, and enterocyte migration in the early postoperative period (16 and 48 h) in vitamin A-sufficient, -deficient, and partially replenished sham-resected and resected rats. At 16 h postresection, apoptosis was significantly greater in the remnant ileum of resected vitamin A-deficient rats compared with the sufficient controls. Crypt cell proliferation was increased by resection in all dietary groups at both timepoints. However, at 48 h postresection, proliferation was significantly decreased in the vitamin A-deficient and partially replenished rats. By 48 h after resection, vitamin A deficiency also reduced enterocyte migration rates by 44%. This occurred in conjunction with decreased immunoreactive collagen IV at 48 h and 10 days postoperation. Laminin expression was also reduced by deficiency at 10 days postresection, whereas fibronectin and pancadherin were unchanged at 48 h and 10 days. These studies indicate that vitamin A deficiency inhibits intestinal adaptation following partial small bowel resection by reducing crypt cell proliferation, by enhancing early crypt cell apoptosis, and by markedly reducing enterocyte migration rates, which may be related to changes in the expression of collagen IV and other extracellular matrix components.
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Affiliation(s)
- Deborah A Swartz-Basile
- Washington Univ. School of Medicine, Dept. of Medicine, Campus Box 8124, 660 South Euclid Ave., St. Louis, MO 63110, USA
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Belik J, Davidge ST, Zhang W, Pan J, Greer JJ. Airway smooth muscle changes in the nitrofen-induced congenital diaphragmatic hernia rat model. Pediatr Res 2003; 53:737-43. [PMID: 12612200 DOI: 10.1203/01.pdr.0000057986.74037.7b] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
In the fetal rat, nitrofen induces congenital diaphragmatic hernia (CDH) and pulmonary vascular remodeling similar to what is observed in the human condition. Airway hyperactivity is common in infants with CDH and attributed to the ventilator-induced airway damage. The purpose of this study was to test the hypothesis that airway smooth muscle mechanical properties are altered in the nitrofen-induced CDH rat model. Lungs from nitrofen-exposed fetuses with hernias (CDH) or intact diaphragm (nitrofen) and untreated fetuses (control) were studied on gestation d 21. The left intrapulmonary artery and bronchi were removed and mounted on a wire myograph, and lung expression, content, and immunolocalization of cyclooxygenases COX-1 and COX-2 were evaluated. Pulmonary artery muscle in the CDH group had significantly (p < 0.01) lower force generation compared with control and nitrofen groups. In contrast, the same generation bronchial smooth muscle of the CDH and nitrofen groups developed higher force compared with control. Whereas no differences were found in endothelium-dependent pulmonary vascular muscle tone, the epithelium-dependent airway muscle relaxation was significantly decreased (p < 0.01) in the CDH and nitrofen groups. The lung mRNA levels of COX-1 and COX-2 were increased in the CDH and nitrofen groups. COX-1 vascular and airway immunostaining, as well as COX-1 and COX-2 lung protein content, were increased in the CDH group. This is the first report of airway smooth muscle abnormalities in the nitrofen-induced fetal rat model of CDH. We speculate that congenital airway muscle changes may be present in the human form of this disease.
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MESH Headings
- 15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5,13-dienoic Acid/pharmacology
- Acetylcholine/pharmacology
- Airway Obstruction/congenital
- Airway Obstruction/physiopathology
- Animals
- Cyclooxygenase 1
- Cyclooxygenase 2
- Disease Models, Animal
- Female
- Hernia, Diaphragmatic/chemically induced
- Hernia, Diaphragmatic/physiopathology
- Hernias, Diaphragmatic, Congenital
- Isoenzymes/genetics
- Isoenzymes/metabolism
- Membrane Proteins
- Muscle, Smooth/drug effects
- Muscle, Smooth/physiology
- Muscle, Smooth/physiopathology
- Pesticides
- Phenyl Ethers
- Potassium Chloride/pharmacology
- Pregnancy
- Prostaglandin-Endoperoxide Synthases/genetics
- Prostaglandin-Endoperoxide Synthases/metabolism
- Pulmonary Artery/physiology
- RNA, Messenger/analysis
- Rats
- Rats, Sprague-Dawley
- Vasoconstrictor Agents/pharmacology
- Vasodilator Agents/pharmacology
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Affiliation(s)
- Jaques Belik
- Department of Pediatrics, Hospital for Sick Children, University of Toronto, Ontario, Canada.
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23
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Medhora M, Daniels J, Mundey K, Fisslthaler B, Busse R, Jacobs ER, Harder DR. Epoxygenase-driven angiogenesis in human lung microvascular endothelial cells. Am J Physiol Heart Circ Physiol 2003; 284:H215-24. [PMID: 12388259 DOI: 10.1152/ajpheart.01118.2001] [Citation(s) in RCA: 93] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Angiogenesis is one of the most recent physiological functions attributed to products of cytochrome P-450 (CYP450) enymes. To test this at a molecular level in human cells, we used a cloned cDNA for the human endothelial enzyme CYP450 2C9 (CYP2C9) to study growth as well as differentiation of human microvascular endothelial cells from the lung (HMVEC-L). Using adenoviral vectors overexpressing mRNA for CYP2C9, we show that the presence of CYP2C9 doubles thymidine incorporation and stimulates proliferation of primary cultures of endothelial cells compared with Ad5-GFP (control) in 24 h. In addition, there is a significant increase of tube formation in Matrigel after infection of HMVEC-L with Ad5-2C9 than with Ad5-GFP. More interestingly, Ad5-2C9 expressing the antisense product of CYP2C9 (2C9AS) inhibited tube formation compared with both Ad5-GFP as well as the Ad5-2C9 constructs. Finally, we tested the most abundant arachidonic acid metabolite of CYP2C9, 14,15-epoxyeicosatrienoic acid, which induced angiogenesis in vivo when embedded in Matrigel plugs and implanted in adult rats. These data support an important role for CYP2C9 in promoting angiogenesis.
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MESH Headings
- 8,11,14-Eicosatrienoic Acid/analogs & derivatives
- 8,11,14-Eicosatrienoic Acid/pharmacology
- Adenoviridae
- Animals
- Aryl Hydrocarbon Hydroxylases/genetics
- Aryl Hydrocarbon Hydroxylases/pharmacology
- Cells, Cultured
- Cytochrome P-450 CYP2C9
- DNA/biosynthesis
- Endothelium, Vascular/drug effects
- Endothelium, Vascular/physiology
- Gene Transfer Techniques
- Genetic Vectors
- Humans
- Microcirculation/drug effects
- Neovascularization, Physiologic/drug effects
- Neovascularization, Physiologic/physiology
- Pulmonary Circulation/drug effects
- Rats
- Rats, Sprague-Dawley
- Vasodilator Agents/pharmacology
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Affiliation(s)
- Meetha Medhora
- Division of Pulmonary and Critical Care, Department of Medicine, Cardiovascular Center, Medical College of Wisconsin, Milwaukee 53226, USA.
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Rossi L, Corvò R. Retinoic acid modulates the radiosensitivity of head-and-neck squamous carcinoma cells grown in collagen gel. Int J Radiat Oncol Biol Phys 2002; 53:1319-27. [PMID: 12128135 DOI: 10.1016/s0360-3016(02)02865-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
PURPOSE Collagen gels are increasingly regarded as reliable scaffolds for studying cells in vitro, displaying the same three-dimensional network of collagen fibers as encountered in vivo. As a contribution to therapeutic control of head-and-neck cancer, we grew HSCO86 cells in collagen gel and assessed their behavior in the presence of retinoic acid (RA) and radiation. METHODS AND MATERIALS The malignant epithelial cell line HSCO86 was isolated from a postirradiation human oropharyngeal squamous carcinoma; it was EGFR-negative by immunocytochemical criteria. The cells were embedded in hydrated collagen I at a density of 10(6) cells/mL, and on Days 8, 10, and 12 of culture, they were treated with 10(-5) M retinoic acid. Radiation was administered using two different schedules: simultaneously with RA in three daily doses totaling 10 Gy, or with a single dose of 8 Gy on Day 29 of culture, after the effects of RA had taken place. Cell proliferation was evaluated by the MTT assay, whereas morphometric characteristics were detected in the cultured gels directly or in the gels after they were fixed and stained with hematoxylin. RESULTS Contrary to growth in monolayer, where HSCO86 cells displayed a high proliferation rate, in collagen gel only a tiny fraction of the cells, usually less than 0.02%, survived the environmental stress; these cells spontaneously organized themselves into clonal multicellular spheroids growing up to 0.8 mm in diameter. After exposure to 10(-5) M retinoic acid, cell proliferation first declined and then, about 15 days after treatment, it started to increase to a level far above that in the control group. This surge in proliferation was ascribed to the appearance of numerous fibroblast-like cells at the edge of the spheroids. These cells, called HSCO-F, were the result of epithelial-to-mesenchymal conversion. When the gels were disaggregated by collagenase, and the cells were seeded in monolayer, HSCO-F cells reversed their morphology into parental HSCO86 cells. Treatment of collagen gels with 10 Gy, fractionated in three daily doses, did not substantially affect the growth of HSCO86 spheroids. However, when radiation was given simultaneously with RA, cell growth was significantly inhibited, both in terms of cell proliferation and size of spheroids (p < 0.0001 vs. untreated controls). This synergism applied mainly to parental HSCO86 cells, because no significant damage was induced by radiation on the HSCO-F cells previously generated by treatment with RA. CONCLUSION Differences in the radiosensitivity of HSCO86 and HSCO-F cells are surprising in view of their common origin; this suggests a scenario in which, to overcome a microenvironmental stress, head-and-neck carcinoma cells can temporarily shift from an epithelial to a mesenchymal phenotype. In particular, morphologic and functional data suggested that HSCO-F cells were transformed into vascular endothelial cells whose characteristics included the following: (1) distinctive expression of Factor VIII and beta(1)-integrin, not detected in parental HSCO86 cells; (2) active migration in the collagen network by extruded pseudopodia, frequently appearing as colonies of filamentous cells aligned along the radial axis of the spheroids; and (3) efficient contraction of floating collagen gels. The implication of our study is that head-and-neck carcinomas may respond to RA treatment by selecting cell populations both resistant to radiation and capable of migrating inside the connective tissue, mimicking the behavior of vascular capillaries.
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Affiliation(s)
- Lorenzo Rossi
- Laboratory of Comparative Oncology, University of Genoa, Genoa, Italy.
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