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Zhuang W, Mitrou NGA, Kulak S, Cupples WA, Braam B. Modulation of the expression of connexins 37, 40, and 43 in endothelial cells in a culture. FRONTIERS IN NETWORK PHYSIOLOGY 2024; 4:1199198. [PMID: 38558785 PMCID: PMC10978589 DOI: 10.3389/fnetp.2024.1199198] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/03/2023] [Accepted: 02/28/2024] [Indexed: 04/04/2024]
Abstract
Connexin (Cx) 37, 40, and 43 are implicated in vascular function, specifically in the electrical coupling of endothelial cells and vascular smooth-muscle cells. In the present study, we investigated whether factors implicated in vascular dysfunction can modulate the gene expression of Cx37, Cx40, and Cx43 and whether this is associated with changes in endothelial layer barrier function in human microvascular endothelial cells (HMEC-1). First, HMEC-1 were subjected to stimuli for 4 and 8 h. We tested their responses to DETA-NONOate, H2O2, high glucose, and angiotensin II, none of which relevantly affected the transcription of the connexin genes. Next, we tested inflammatory factors IL-6, interferon gamma (IFNγ), and TNFα. IFNγ (10 ng/mL) consistently induced Cx40 expression at 4 and 8 h to 10-20-fold when corrected for the control. TNFα and IL-6 resulted in small but significant depressions of Cx37 expression at 4 h. Two JAK inhibitors, epigallocatechin-3-gallate (EGCG) (100-250 μM) and AG490 (100-250 μM), dose-dependently inhibited the induction of Cx40 expression by IFNγ. Subsequently, HMEC-1 were subjected to 10 ng/mL IFNγ for 60 h, and intercellular and transcellular impedance was monitored by electric cell-substrate impedance sensing (ECIS). In response to IFNγ, junctional-barrier impedance increased more than cellular-barrier impedance; this was prevented by AG490 (5 μM). In conclusion, IFNγ can strongly induce Cx40 expression and modify the barrier properties of the endothelial cell membrane through the JAK/STAT pathway. Moreover, the Cx37, Cx40, and Cx43 expression in endothelial cells is stable and, apart from IFNγ, not affected by a number of factors implicated in endothelial dysfunction and vascular diseases.
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Affiliation(s)
- Wenqing Zhuang
- Division of Nephrology, Department of Medicine, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada
| | | | - Steve Kulak
- Division of Nephrology, Department of Medicine, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada
| | | | - Branko Braam
- Division of Nephrology, Department of Medicine, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada
- Department of Physiology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada
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Graceffa V. Therapeutic Potential of Reactive Oxygen Species: State of the Art and Recent Advances. SLAS Technol 2020; 26:140-158. [PMID: 33345675 DOI: 10.1177/2472630320977450] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
In the last decade, several studies have proven that when at low concentration reactive oxygen species (ROS) show an adaptive beneficial effect and posited the idea that they can be utilized as inexpensive and convenient inducers of tissue regeneration. On the other hand, the recent discovery that cancer cells are more sensitive to oxidative damage paved the way for their use in the selective killing of tumor cells, and sensors to monitor ROS production during cancer treatment are under extensive investigation. Nevertheless, although ROS-activated signaling pathways are well established, less is known about the mechanisms underlying the switch from an anabolic to a cytotoxic response. Furthermore, a high variability in biological response is observed between different modalities of administration, cell types, donor ages, eventual concomitant diseases, and external microenvironment. On the other hand, available preclinical studies are scarce, whereas the quest for the most suitable systems for in vivo delivery is still elusive. Furthermore, new strategies to control the temporal pattern of ROS release need to be developed, if considering their tumorigenic potential. This review initially discusses ROS mechanisms of action and their potential application in stem cell biology, tissue engineering, and cancer therapy. It then outlines the state of art of ROS-based drugs and identifies challenges faced in translating ROS research into clinical practice.
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Affiliation(s)
- Valeria Graceffa
- Cellular Health and Toxicology Research Group (CHAT), Institute of Technology Sligo, Bellanode, Sligo, Ireland.,Department of Life Sciences, Institute of Technology Sligo, Bellanode, Sligo, Ireland
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Labonté LE, Bourbeau J, Daskalopoulou SS, Zhang M, Coulombe P, Garland K, Baglole CJ. Club Cell-16 and RelB as Novel Determinants of Arterial Stiffness in Exacerbating COPD Patients. PLoS One 2016; 11:e0149974. [PMID: 26914709 PMCID: PMC4767820 DOI: 10.1371/journal.pone.0149974] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2015] [Accepted: 02/08/2016] [Indexed: 01/15/2023] Open
Abstract
Background Exacerbations of chronic obstructive pulmonary disease (COPD) are acute events of worsened respiratory symptoms that may increase the risk of cardiovascular disease (CVD), a leading cause of mortality amongst COPD patients. The utility of lung-specific inflammatory mediators such as club cell protein-16 (CC-16) and surfactant protein D (SPD) and that of a novel marker of CV outcomes in COPD- RelB- in predicting adverse cardiovascular events during exacerbation is not known. Methods Thirty-eight subjects with COPD admitted to the hospital for severe exacerbation were included in this analysis. Clinical, physiological and arterial stiffness measurements were performed within 72 hours of admission; this was followed by measurements taken every 3 days until hospital discharge, then once a week until 30 days after discharge, and then again at 90 and 180 days. Plasma concentrations of inflammatory mediators were measured from peripheral venous blood taken at admission, and at days 15, 30, 90 and 180. Results CC-16 and RelB concentrations were increased at day 15 of exacerbations whereas SPD concentrations were decreased. The course of change in CC-16 and RelB levels over time was inversely associated with that of carotid-femoral pulse wave velocity, the gold-standard measure of arterial stiffness. Increases in CC-16 could predict a decreased number of subsequent exacerbations during follow-up. Conclusions Lung-specific (CC-16) and novel (RelB) biomarkers are associated with systemic cardiovascular changes over time. CC-16 can predict subsequent exacerbations in subjects with severe COPD and may be an important biomarker of pulmonary and systemic stress in COPD.
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Affiliation(s)
- Laura E. Labonté
- Department of Medicine, McGill University, Montreal, Quebec, Canada
- Respiratory Epidemiology and Clinical Research Unit, Research Institute of the McGill University Health Center, Montreal, Québec, Canada
| | - Jean Bourbeau
- Department of Medicine, McGill University, Montreal, Quebec, Canada
- Respiratory Epidemiology and Clinical Research Unit, Research Institute of the McGill University Health Center, Montreal, Québec, Canada
| | | | - Michele Zhang
- Respiratory Epidemiology and Clinical Research Unit, Research Institute of the McGill University Health Center, Montreal, Québec, Canada
| | - Patrick Coulombe
- Respiratory Epidemiology and Clinical Research Unit, Research Institute of the McGill University Health Center, Montreal, Québec, Canada
| | - Katie Garland
- Respiratory Epidemiology and Clinical Research Unit, Research Institute of the McGill University Health Center, Montreal, Québec, Canada
| | - Carolyn J. Baglole
- Department of Medicine, McGill University, Montreal, Quebec, Canada
- Department of Pathology, McGill University, Montreal, Quebec, Canada
- Department of Pharmacology & Therapeutics, McGill University, Montreal, Québec, Canada
- Meakins Christie Laboratories, McGill University, Montreal, Québec, Canada
- * E-mail:
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Labonté L, Coulombe P, Zago M, Bourbeau J, Baglole CJ. Alterations in the expression of the NF-κB family member RelB as a novel marker of cardiovascular outcomes during acute exacerbations of chronic obstructive pulmonary disease. PLoS One 2014; 9:e112965. [PMID: 25409035 PMCID: PMC4237338 DOI: 10.1371/journal.pone.0112965] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2014] [Accepted: 10/16/2014] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Chronic obstructive pulmonary disease (COPD) exacerbations are acute events of worsened respiratory symptoms and enhanced inflammation partly mediated by NF-κB activation. RelB, an NF-κB family member, suppresses cigarette smoke-induced inflammation but its expression in COPD is unknown. Moreover, there is no information on its association with clinical features of COPD. The objectives of this study were to assess RelB expression relative to markers of inflammation as well as its association with cardiovascular and pulmonary features of COPD patients at stable-state and exacerbation. METHODS Data from 48 COPD patients were analyzed. Blood samples were collected from stable-state and exacerbating patients. After RNA isolation, quantitative real-time polymerase chain reaction (qRT-PCR) was performed to assess RelB, Cox-2, IL-8 and IL-1β mRNA expression and their associations with measured clinical variables. RESULTS Of the 48 COPD subjects, 18 were in stable-state and 30 were in exacerbation. RelB mRNA expression was lower than that of Cox-2, IL-8, and IL-1β in all cases (all p<0.001, except for IL-8 at exacerbation (p = 0.22)). Cox-2, IL-8 and IL-1β were significantly associated with clinical features of patients in both stable-state and at exacerbation. There was no association with RelB expression and any clinical features in COPD subjects at stable-state. RelB mRNA levels were significantly associated with cardiovascular events such as systolic blood pressure during exacerbation. CONCLUSIONS RelB mRNA expression is lower than that of the other inflammatory mediators. Expression of Cox-2, IL-8 and IL-1β were related to clinical features in both stable-state and at exacerbation. However, RelB expression was associated with clinical features of patients only during exacerbation, suggesting that RelB may represent a novel marker of health outcomes, in particular cardiovascular, during exacerbation in COPD.
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Affiliation(s)
- Laura Labonté
- Department of Medicine, McGill University, Montreal, Quebec, Canada
- Respiratory Epidemiology and Clinical Research Unit (RECRU), Montreal Chest Institute, McGill University Health Centre, Montreal, Quebec, Canada
| | - Patrick Coulombe
- Respiratory Epidemiology and Clinical Research Unit (RECRU), Montreal Chest Institute, McGill University Health Centre, Montreal, Quebec, Canada
| | - Michela Zago
- Department of Medicine, McGill University, Montreal, Quebec, Canada
- Meakins-Christie Laboratories, McGill University, Montreal, Quebec, Canada
| | - Jean Bourbeau
- Department of Medicine, McGill University, Montreal, Quebec, Canada
- Respiratory Epidemiology and Clinical Research Unit (RECRU), Montreal Chest Institute, McGill University Health Centre, Montreal, Quebec, Canada
| | - Carolyn J. Baglole
- Department of Medicine, McGill University, Montreal, Quebec, Canada
- Meakins-Christie Laboratories, McGill University, Montreal, Quebec, Canada
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Stinghen AEM, Chillon JM, Massy ZA, Boullier A. Differential effects of indoxyl sulfate and inorganic phosphate in a murine cerebral endothelial cell line (bEnd.3). Toxins (Basel) 2014; 6:1742-60. [PMID: 24902077 PMCID: PMC4073127 DOI: 10.3390/toxins6061742] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2014] [Revised: 05/17/2014] [Accepted: 05/26/2014] [Indexed: 12/29/2022] Open
Abstract
Endothelial dysfunction plays a key role in stroke in chronic kidney disease patients. To explore the underlying mechanisms, we evaluated the effects of two uremic toxins on cerebral endothelium function. bEnd.3 cells were exposed to indoxyl sulfate (IS) and inorganic phosphate (Pi). Nitric oxide (NO), reactive oxygen species (ROS) and O2•⁻ were measured using specific fluorophores. Peroxynitrite and eNOS uncoupling were evaluated using ebselen, a peroxide scavenger, and tetrahydrobiopterin (BH₄), respectively. Cell viability decreased after IS or Pi treatment (p < 0.01). Both toxins reduced NO production (IS, p < 0.05; Pi, p < 0.001) and induced ROS production (p < 0.001). IS and 2 mM Pi reduced O2•⁻ production (p < 0.001). Antioxidant pretreatment reduced ROS levels in both IS- and Pi-treated cells, but a more marked reduction of O2•⁻ production was observed in Pi-treated cells (p < 0.001). Ebselen reduced the ROS production induced by the two toxins (p < 0.001); suggesting a role of peroxynitrite in this process. BH₄ addition significantly reduced O2•⁻ and increased NO production in Pi-treated cells (p < 0.001), suggesting eNOS uncoupling, but had no effect in IS-treated cells. This study shows, for the first time, that IS and Pi induce cerebral endothelial dysfunction by decreasing NO levels due to enhanced oxidative stress. However, Pi appears to be more deleterious, as it also induces eNOS uncoupling.
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Affiliation(s)
- Andréa E M Stinghen
- Inserm U1088, Department of Pharmacy, 1 rue des Louvels, Amiens F-80037 Cédex 1, France.
| | - Jean-Marc Chillon
- Inserm U1088, Department of Pharmacy, 1 rue des Louvels, Amiens F-80037 Cédex 1, France.
| | - Ziad A Massy
- Inserm U1088, Department of Pharmacy, 1 rue des Louvels, Amiens F-80037 Cédex 1, France.
| | - Agnès Boullier
- Inserm U1088, Department of Pharmacy, 1 rue des Louvels, Amiens F-80037 Cédex 1, France.
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Methods for detection and characterization of protein S-nitrosylation. Methods 2013; 62:138-50. [PMID: 23628946 DOI: 10.1016/j.ymeth.2013.04.016] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2012] [Revised: 04/15/2013] [Accepted: 04/18/2013] [Indexed: 11/24/2022] Open
Abstract
Reversible protein S-nitrosylation, defined as the covalent addition of a nitroso moiety to the reactive thiol group on a cysteine residue, has received increasing recognition as a critical post-translational modification that exerts ubiquitous influence in a wide range of cellular pathways and physiological processes. Due to the lability of the S-NO bond, which is a dynamic modification, and the low abundance of endogenously S-nitrosylated proteins in vivo, unambiguous identification of S-nitrosylated proteins and S-nitrosylation sites remains methodologically challenging. In this review, we summarize recent advancements and the use of state-of-art approaches for the enrichment, systematic identification and quantitation of S-nitrosylation protein targets and their modification sites at the S-nitrosoproteome scale. These advancements have facilitated the global identification of >3000 S-nitrosylated proteins that are associated with wide range of human diseases. These strategies hold promise to site-specifically unravel potential molecular targets and to change S-nitrosylation-based pathophysiology, which may further the understanding of the potential role of S-nitrosylation in diseases.
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Nitric oxide attenuates matrix metalloproteinase-9 production by endothelial cells independent of cGMP- or NFκB-mediated mechanisms. Mol Cell Biochem 2013; 378:127-35. [PMID: 23456480 DOI: 10.1007/s11010-013-1602-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2012] [Accepted: 02/23/2013] [Indexed: 01/14/2023]
Abstract
Cardiovascular diseases involve critical mechanisms including impaired nitric oxide (NO) levels and abnormal matrix metalloproteinase (MMP) activity. While NO downregulates MMP expression in some cell types, no previous study has examined whether NO downregulates MMP levels in endothelial cells. We hypothesized that NO donors could attenuate MMP-9 production by human umbilical vein endothelial cells (HUVECs) as a result of less NFκB activation or cyclic GMP (cGMP)-mediated mechanisms. We studied the effects of DetaNONOate (10-400 μM) or SNAP (50-400 μM) on phorbol 12-myristate 13-acetate (PMA; 10 nM)-induced increases in MMP-9 activity (by gel zymography) or concentrations (by ELISA) as well as on a tissue inhibitor of MMPs' (TIMP)-1 concentrations (by ELISA) in the conditioned medium of HUVECs incubated for 24 h with these drugs. We also examined whether the irreversible inhibitor of soluble guanylyl cyclase ODQ modified the effects of SNAP or whether 8-bromo-cGMP (a cell-permeable analog of cGMP) influenced PMA-induced effects on MMP-9 expression. Total and phospho-NFκB p65 concentrations were measured in HUVEC lysates to assess NFκB activation. Both NO donors attenuated PMA-induced increases in MMP-9 activity and concentrations without significantly affecting TIMP-1 concentrations. This effect was not modified by ODQ, and 8-bromo-cGMP did not affect MMP-9 concentrations. While PMA increased phospho-NFκB p65 concentrations, SNAP had no influence on this effect. In conclusion, this study shows that NO donors may attenuate imbalanced MMP expression and activity in endothelial cells independent of cGMP- or NFκB-mediated mechanisms. Our results may offer an important pharmacological strategy to approach cardiovascular diseases.
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Gentile C, Muise-Helmericks RC, Drake CJ. VEGF-mediated phosphorylation of eNOS regulates angioblast and embryonic endothelial cell proliferation. Dev Biol 2012; 373:163-75. [PMID: 23103584 DOI: 10.1016/j.ydbio.2012.10.020] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2012] [Revised: 10/04/2012] [Accepted: 10/16/2012] [Indexed: 10/27/2022]
Abstract
To evaluate potential roles of nitric oxide (NO) in the regulation of the endothelial lineage and neovascular processes (vasculogenesis and angiogenesis) we evaluated endothelial nitric oxide synthase (eNOS) and phosphorylated eNOS (p-eNOS) expression in 7.2-8.5 days post-coitum (dpc) mouse embryos. Analysis revealed that p-eNOS((S1177)) but not P-eNOS((S617)) or P-eNOS((T495)) was expressed in a subpopulation of angioblasts (TAL-1(+)/Flk-1(+)/CD31(-)/CD34(-)/VE-Cadherin(-)) at 7.2 dpc. A role of the VEGF/Akt1/eNOS signaling pathway in the regulation of the endothelial cell (EC) lineage was suggested by the strong correlation observed between cell division and p-eNOS((S1177)) expression in both angioblasts and embryonic endothelial cells (EECs, TAL-1(+)/Flk-1(+)/CD31(+)/CD34(+)/VE-Cadherin(+)). Our studies using Akt1 null mouse embryos show a reduction in p-eNOS((S1177)) expression in angioblast and EECs that is correlated with a decrease in endothelial cell proliferation and results in changes in VEGF-induced vascular patterning. Further, we show that VEGF-mediated cell proliferation in Flk-1(+) cells in allantoic cultures is decreased by pharmacological inhibitors of the VEGF/Akt1/eNOS signaling pathways. Taken together, our findings suggest that VEGF-mediated eNOS phosphorylation on Ser1177 regulates angioblast and EEC division, which underlies the formation of blood vessels and vascular networks.
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Affiliation(s)
- Carmine Gentile
- Department of Regenerative Medicine and Cell Biology, Medical University of South Carolina, Charleston, SC 29425, USA
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Koeners MP, Braam B, Joles JA. Blood pressure follows the kidney: Perinatal influences on hereditary hypertension. Organogenesis 2012; 4:153-7. [PMID: 19279727 DOI: 10.4161/org.4.3.6504] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2008] [Accepted: 05/13/2008] [Indexed: 12/24/2022] Open
Abstract
Epidemiological and experimental data strongly suggest that cardiovascular diseases can originate from an aberrant environment during fetal development, a phenomenon referred to as perinatal programming. This review will focus on the role of the kidneys in determining blood pressure, and how (re)programming the renal development can persistently ameliorate hereditary hypertension. By combining physiologic and genomic studies we have discovered some candidate pathways suited for (re)programming the development of hypertension. This sets the stage for mechanistic analysis in future studies.
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Affiliation(s)
- Maarten P Koeners
- Department of Nephrology and Hypertension; University Medical Center; Utrecht The Netherlands
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Effects of Thai medicinal herb extracts with anti-psoriatic activity on the expression on NF-κB signaling biomarkers in HaCaT keratinocytes. Molecules 2011; 16:3908-32. [PMID: 21555979 PMCID: PMC6263342 DOI: 10.3390/molecules16053908] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2011] [Revised: 04/25/2011] [Accepted: 05/04/2011] [Indexed: 01/01/2023] Open
Abstract
Psoriasis is a chronic inflammatory skin disorder characterized by rapid proliferation of keratinocytes and incomplete keratinization. Discovery of safer and more effective anti-psoriatic drugs remains an area of active research at the present time. Using a HaCaT keratinocyte cell line as an in vitro model, we had previously found that ethanolic extracts from three Thai medicinal herbs, namely Alpinia galanga, Curcuma longa and Annona squamosa, possessed anti-psoriatic activity. In the current study, we aimed at investigating if these Thai medicinal herb extracts played a molecular role in suppressing psoriasis via regulation of NF-κB signaling biomarkers. Using semi-quantitative RT-PCR and report gene assays, we analyzed the effects of these potential herbal extracts on 10 different genes of the NF-κB signaling network in HaCaT cells. In accordance with our hypothesis, we found that the extract derived from Alpinia galanga significantly increased the expression of TNFAIP3 and significantly reduced the expression of CSF-1 and NF-κB2. Curcuma longa extract significantly decreased the expression of CSF-1, IL-8, NF-κB2, NF-κB1 and RelA, while Annona squamosa extract significantly lowered the expression of CD40 and NF-κB1. Therefore, this in vitro study suggested that these herbal extracts capable of functioning against psoriasis, might exert their activity by controlling the expression of NF-κB signaling biomarkers.
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Nitric oxide affects IL-6 expression in human peripheral blood mononuclear cells involving cGMP-dependent modulation of NF-κB activity. Cytokine 2011; 54:282-8. [PMID: 21414799 DOI: 10.1016/j.cyto.2011.02.015] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2010] [Revised: 02/14/2011] [Accepted: 02/15/2011] [Indexed: 01/08/2023]
Abstract
Interleukin 6 (IL-6) and nitric oxide (NO) are important mediators of the inflammatory response. We report that in human peripheral blood mononuclear cells (PBMCs), NO exerts a biphasic effect on the expression of IL-6. Using sodium nitroprusside (SNP) and S-nitrosoglutathione (GSNO) as NO-donating compounds, we observed that both mRNA and protein levels of IL-6 increased at lower (≤10μM) and decreased at higher (>100μM) concentrations of NO donors. Changes in the expression of IL-6 correlated with changes in the activity of NF-κB, which increased at lower and decreased at higher concentrations of both NO donors as shown by the electrophoretic mobility shift assay (EMSA). The effects of NO on NF-κB activity were cGMP-dependent because they were reversed in the presence of ODQ, the inhibitor of soluble guanylyl cyclase (sGC), and KT5823, the inhibitor of cGMP-dependent protein kinase (PKG). Moreover, the membrane permeable analog of cGMP (8-Br-cGMP) mimicked the effect of the NO donors. These observations show that NO, depending on its concentration, may act in human PBMCs as a stimulator of IL-6 expression involving the sGC/cGMP/PKG pathway.
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Stewart JA, West TA, Lucchesi PA. Nitric oxide-induced collagen IV expression and angiogenesis: FAK or fiction? Focus on "Collagen IV contributes to nitric oxide-induced angiogenesis of lung endothelial cells". Am J Physiol Cell Physiol 2011; 300:C968-9. [PMID: 21389280 DOI: 10.1152/ajpcell.00059.2011] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Chen YJ, Ku WC, Lin PY, Chou HC, Khoo KH, Chen YJ. S-alkylating labeling strategy for site-specific identification of the s-nitrosoproteome. J Proteome Res 2010; 9:6417-39. [PMID: 20925432 DOI: 10.1021/pr100680a] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
S-nitrosylation, a post-translational modification of cysteine residues induced by nitric oxide, mediates many physiological functions. Due to the labile nature of S-nitrosylation, detection by mass spectrometry (MS) is challenging. Here, we developed an S-alkylating labeling strategy using the irreversible biotinylation on S-nitrosocysteines for site-specific identification of the S-nitrosoproteome by LC-MS/MS. Using COS-7 cells without endogenous nitric oxide synthase, we demonstrated that the S-alkylating labeling strategy substantially improved the blocking efficiency of free cysteines, minimized the false-positive identification caused by disulfide interchange, and increased the digestion efficiency for improved peptide identification using MS analyses. Using this strategy, we identified total 586 unique S-nitrosylation sites corresponding to 384 proteins in S-nitroso-N-acetylpenicillamine (SNAP)/l-cysteine-treated mouse MS-1 endothelial cells, including 234 previously unreported S-nitrosylated proteins. When the topologies of 84 identified transmembrane proteins were further analyzed, their S-nitrosylation sites were found to mostly face the cytoplasmic side, implying that S-nitrosylation occurs in the cytoplasm. In addition to the previously known acid/basic motifs, the ten deduced consensus motifs suggested that combination of local hydrophobicity and acid/base motifs in the tertiary structure contribute to the specificity of S-nitrosylation. Moreover, the S-nitrosylated cysteines showed preference on beta-strand, having lower relative surface accessibility at the S-nitrosocysteines.
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Affiliation(s)
- Yi-Ju Chen
- Institute of Biochemical Sciences, National Taiwan University, Taipei, Taiwan.
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Rabkin SW. Nitric oxide and peroxynitrite induce gene expression of interleukin receptors increasing IL-21, IL-7, IL-1 and oncostatin M in cardiomyocytes. Life Sci 2010; 86:45-51. [DOI: 10.1016/j.lfs.2009.11.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2009] [Revised: 11/03/2009] [Accepted: 11/04/2009] [Indexed: 11/25/2022]
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Genome expression profiling and network analysis of nitrite therapy during chronic ischemia: possible mechanisms and interesting molecules. Nitric Oxide 2009; 22:168-79. [PMID: 19963074 DOI: 10.1016/j.niox.2009.11.008] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2009] [Revised: 11/10/2009] [Accepted: 11/26/2009] [Indexed: 12/12/2022]
Abstract
Sodium nitrite is widely recognized to be a highly effective NO donor for the treatment of several ischemic tissue disorders. However, mechanisms by which nitrite confers cytoprotection during ischemic disorders remain largely unknown. In this study, we used genome expression profiling approaches to evaluate changes in gene expression in the hind-limb ischemia model using vehicle or sodium nitrite therapy. Sodium nitrite significantly restored ischemic tissue perfusion by day 3 post-ligation which returned to normal by day 7. Genesifter analysis of Affymetrix GeneChip data revealed a significant down-regulation of gene expression profiles at day 3, whereas gene expression profiles were predominantly up-regulated at day 7. Ingenuity network analysis of gene expression profiles at day 3 showed a strong decrease in gene expression from networks associated with immune functions such as acute inflammatory responses, antigen presentation, and humoral immune responses while networks containing increased gene expression profiles were associated with cardiovascular, skeletal, and muscle system development and function. Network analysis of day 7 gene array data revealed predominant up-regulation of genes associated with cell survival, tissue morphology, connective tissue function, skeletal and muscular system development, and lymphoid tissue structure and development. These data suggest that sodium nitrite elicits potent anti-inflammatory and pro-angiogenic gene responses at early time points which is later followed by up-regulation of genes associated with tissue repair and homeostasis.
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Illi B, Colussi C, Grasselli A, Farsetti A, Capogrossi MC, Gaetano C. NO sparks off chromatin: tales of a multifaceted epigenetic regulator. Pharmacol Ther 2009; 123:344-52. [PMID: 19464317 DOI: 10.1016/j.pharmthera.2009.05.003] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2009] [Accepted: 05/11/2009] [Indexed: 10/20/2022]
Abstract
The discovery of nitric oxide (NO) revealed its ambiguous nature, which is related to its pleiotropic activities that control the homeostasis of every organism from bacteria to mammals in several physiological and pathological situations. The wide range of action of NO basically depends on two features: 1) the variety of chemical reactions depending on NO, and 2) the differential cellular responses elicited by distinct NO concentrations. Despite the increasing body of knowledge regarding its chemistry, biology and NO-dependent signaling pathways, little information is available on the nuclear actions of NO in terms of gene expression regulation. Indeed, studies of a putative role for this diatomic compound in regulating chromatin remodeling are still in their infancy. Only recently has the role of NO in epigenetics emerged, and some of its putative epigenetic properties are still only hypothetical. In the present review, we discuss the current evidence for NO-related mechanisms of epigenetic gene expression regulation. We link some of the well known NO chemical reactions and metabolic processes (e.g., S-nitrosylation of thiols, tyrosine nitration, cGMP production) to chromatin modification and address the most recent, striking hypothesis about NO and the control of chromosomes structure.
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Affiliation(s)
- Barbara Illi
- Laboratorio di Biologia Vascolare e Medicina Rigenerativa, Centro Cardiologico Monzino-IRCCS, Milan, Italy
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The presence and activity of SP-D in porcine coronary endothelial cells depend on Akt/PI3K, Erk and nitric oxide and decrease after multiple passaging. Mol Immunol 2009; 46:1050-7. [DOI: 10.1016/j.molimm.2008.09.027] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2008] [Accepted: 09/24/2008] [Indexed: 12/23/2022]
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18
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Lee MYK, Tse HF, Siu CW, Zhu SG, Man RYK, Vanhoutte PM. Genomic changes in regenerated porcine coronary arterial endothelial cells. Arterioscler Thromb Vasc Biol 2007; 27:2443-9. [PMID: 17942849 DOI: 10.1161/atvbaha.107.141705] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
OBJECTIVE Genomic changes were defined in cultures of regenerated porcine coronary endothelial cells to explain the alterations that underlie their dysfunction. METHODS AND RESULTS Regeneration of the endothelium was triggered in vivo by endothelial balloon denudation. After 28 days, both left circumflex (native cells) and left anterior descending (regenerated cells) coronary arteries were dissected, their endothelial cells harvested, and primary cultures established. The basal cyclic GMP production was reduced in regenerated cells without significant reduction in the response to bradykinin and A23187. The mRNA expression levels in both native and regenerated cells were measured by microarray and RT-PCR. The comparison revealed genomic changes related to vasomotor control (cyclooxygenase-1, angiotensin II receptor), coagulation (F2 and TFPI), oxidative stress (Mn SOD, GPX3, and GSR), lipid metabolism (PLA2 and HPGD), and extracellular matrix (MMPs). A-FABP and MMP7 were induced by regeneration. RT-PCR revealed upregulation of A-FABP and downregulation of eNOS and TR. The differential gene expression profiles were confirmed at the protein level by Western blotting for eNOS, F2, Mn SOD, MMP7, and TR. CONCLUSIONS Cultures from regenerated coronary endothelial cells exhibit genomic changes explaining endothelial dysfunction and suggesting facilitation of coagulation, lipid peroxidation, and extracellular matrix remodeling.
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Affiliation(s)
- Mary Y K Lee
- Department of Pharmacology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, 2F Laboratory Block, 21 Sassoon Road, Pokfulam, Hong Kong
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19
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Wesseling S, Joles JA, van Goor H, Bluyssen HA, Kemmeren P, Holstege FC, Koomans HA, Braam B. Transcriptome-based identification of pro- and antioxidative gene expression in kidney cortex of nitric oxide-depleted rats. Physiol Genomics 2007; 28:158-67. [PMID: 17047089 DOI: 10.1152/physiolgenomics.00077.2006] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Nitric oxide (NO) depletion in rats induces severe endothelial dysfunction within 4 days. Subsequently, hypertension and renal injury develop, which are ameliorated by α-tocopherol (VitE) cotreatment. The hypothesis of the present study was that NO synthase (NOS) inhibition induces a renal cortical antioxidative transcriptional response and invokes pro-oxidative and proinflammatory gene expression due to elimination of dampening effects of NO and enhanced oxidative stress. Male Sprague-Dawley rats received NOS inhibitor Nω-nitro-l-arginine (l-NNA, 500 mg/l water) for 4 (4d-LNNA), 21 (21d-LNNA), or 21 days with VitE in chow (0.7 g/kg body wt/day). Renal cortical RNA was applied to oligonucleotide rat arrays. In 4d-LNNA, 21d-LNNA, and 21d-LNNA+VitE, 120, 320, and 184 genes were differentially expressed, respectively. Genes related to glutathione and bilirubin synthesis were suppressed during 4d and 21d-LNNA and not corrected by VitE. Proteinuria, tubulointerstitial macrophages, and heme-oxygenase-1 (HO-1) expression were strongly correlated. Remarkably, pro-oxidative genes were not induced. Inflammation- and injury-related genes, including kidney injury molecule-1 and osteopontin, were unchanged at day 4, induced at 21d, and partly corrected by VitE. Superimposing HO-1 inhibition on NOS inhibition had no impact on the development of hypertension. To summarize, renal expression of genes involved in synthesis of the antioxidants glutathione and bilirubin seemed directly NO dependent, but there were no direct effects of NO depletion on pro-oxidant systems. This indicates that renal transcriptional regulation of two defense systems, glutathione and bilirubin syntheses, seems to depend upon adequate NO synthesis. Interaction between NO synthesis and heme degradation pathways for blood pressure regulation was not found.
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Gruel G, Lucchesi C, Pawlik A, Frouin V, Alibert O, Kortulewski T, Zarour A, Jacquelin B, Gidrol X, Tronik-Le Roux D. Novel Microarray-Based Method for Estimating Exposure to Ionizing Radiation. Radiat Res 2006; 166:746-56. [PMID: 17067202 DOI: 10.1667/rr0260.1] [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: 04/22/2005] [Accepted: 06/23/2006] [Indexed: 11/03/2022]
Abstract
Accurate estimation of the dose of ionizing radiation to which individuals have been exposed is critical for therapeutic treatment. We investigated whether gene expression profiles could be used to evaluate the dose received, thereby serving as a biological dosimeter. We used cDNA microarrays to monitor changes in gene expression profiles induced by ionizing radiation in mouse total blood. The subsets of genes best characterizing each dose were identified by resampling the original data set and calculating the intersection of the dose signatures. This analytical strategy minimizes the impact of potential genetic/epigenetic variation between mice and overcomes the bias in gene selection inherent to microarray technology. The significance of the identified signatures was evaluated by monitoring the type I error rate by in silico negative control simulation. Based on the distribution of the mean ratios of the selected probes, we were able to identify transcription profiles giving 83% to 100% correct estimation of the dose received by test mice, demonstrating that the selected probes could be used to determine the dose of radiation to which the animals had been exposed. This method could potentially be generalized to determine the level of exposure to other toxins and could be used to develop new related clinical applications.
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Affiliation(s)
- Gaëtan Gruel
- Service de Génomique Fonctionnelle, Commissariat a l'Energie Atomique (CEA), 91057 Evry Cedex, France
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21
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Covacu R, Danilov AI, Rasmussen BS, Hallén K, Moe MC, Lobell A, Johansson CB, Svensson MA, Olsson T, Brundin L. Nitric oxide exposure diverts neural stem cell fate from neurogenesis towards astrogliogenesis. Stem Cells 2006; 24:2792-800. [PMID: 16916924 DOI: 10.1634/stemcells.2005-0640] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Regeneration of cells in the central nervous system is a process that might be affected during neurological disease and trauma. Because nitric oxide (NO) and its derivatives are powerful mediators in the inflammatory cascade, we have investigated the effects of pathophysiological concentrations of NO on neurogenesis, gliogenesis, and the expression of proneural genes in primary adult neural stem cell cultures. After exposure to NO, neurogenesis was downregulated, and this corresponded to decreased expression of the proneural gene neurogenin-2 and beta-III-tubulin. The decreased ability to generate neurons was also found to be transmitted to the progeny of the cells. NO exposure was instead beneficial for astroglial differentiation, which was confirmed by increased activation of the Janus tyrosine kinase/signal transducer and activator of transcription transduction pathway. Our findings reveal a new role for NO during neuroinflammatory conditions, whereby its proastroglial fate-determining effect on neural stem cells might directly influence the neuroregenerative process.
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Affiliation(s)
- Ruxandra Covacu
- Department of Clinical Neuroscience, Division of Neurology, Neuroimmunology Unit, Karolinska Institutet, Stockholm, Sweden
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22
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Chon H, Verhaar MC, Koomans HA, Joles JA, Braam B. Role of Circulating Karyocytes in the Initiation and Progression of Atherosclerosis. Hypertension 2006; 47:803-10. [PMID: 16520401 DOI: 10.1161/01.hyp.0000210554.61293.90] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Cardiovascular disease is still hard to predict in an individual. The main focus in cardiovascular research has been on endothelial cells and vascular smooth muscle cells of the vessel wall and their interactions with the blood flow. Alterations in the properties of the blood have received a lot of attention in biochemical terms. Interestingly, alterations in the properties of circulating cells have received less attention. We propose that presence of 1 or more risk factors together with normal physiological stimuli induce redox-dependent changes in leukocyte gene transcription with pathophysiological responses. Thus, risk factors render leukocytes hypersensitive to normal stimuli. Risk factors can be subdivided into physical and chemical factors. Superimposed on physiological regulators of leukocyte function, these risk factors promote a cellular pro-oxidative state. Redox-sensitive transcription factors are activated, leading to responses involving inflammation, adhesion, migration, and additional reactive oxygen species generation. As a consequence, monitoring of individual gene expression signatures of these cells could well increase our understanding of the mechanisms by which leukocytes and, in particular, monocytes function. Furthermore, transcriptomes of these cells could be used to investigate the aggressiveness of the atherosclerotic process or to guide treatment in the patient with risk factors for atherosclerosis.
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Affiliation(s)
- Helena Chon
- Department of Nephrology and Hypertension, University Medical Center Utrecht, Utrecht, The Netherlands
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23
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Waldow T, Witt W, Weber E, Matschke K. Nitric oxide donor-induced persistent inhibition of cell adhesion protein expression and NFkappaB activation in endothelial cells. Nitric Oxide 2006; 15:103-13. [PMID: 16504556 DOI: 10.1016/j.niox.2005.12.005] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2005] [Revised: 12/12/2005] [Accepted: 12/14/2005] [Indexed: 02/07/2023]
Abstract
Nitric oxide (NO), applied by inhalation or released from NO donors, has been used to reduce the expression of cell adhesion molecules (CAM) and ameliorate other consequences of ischemia/reperfusion (I/R) injury. In this study, we have assessed the time frames of pretreatment and of the duration of the preconditioned state using human umbilical vein endothelial cells (HUVECs) and the NO donor, SNAP, in combination with cysteine. The induction of vascular cell adhesion molecule (VCAM), intercellular adhesion molecule (ICAM) and E-selectin by the cytokines TNFalpha and IL-1beta, and by bacterial lipopolysaccharide (LPS) was reduced by SNAP/Cys preincubation (30 min, 1mM) to less than 10% of controls. This refractory state in respect to cytokine-induced CAM expression persisted for 6h after washout of the NO donor in the combination TNFalpha/VCAM, and a partial block was still observed after 8h. The effect was not mediated by the cGMP pathway, as was demonstrated by using the inhibitor of guanylyl cyclase, ODQ, and the cGMP analogue, 8-Br-cGMP. The TNFalpha-induced expression of CAM was exclusively dependent on the transcription factor NFkappaB since the inhibitor of NFkappaB activation, BAY 11-7082, completely blocked the induction. The TNFalpha-induced phosphorylation and degradation of the inhibitor of kappaB (IkappaBalpha) was suppressed for up to 8h after SNAP/Cys pretreatment. The inhibitory S-nitrosation of IkappaB kinase (IKKbeta), as assessed by the biotin-switch-procedure and immunoprecipitation, was only detectable immediately after SNAP/Cys incubation but not at later time points. In summary, a short preincubation of HUVEC with SNAP/Cys results in a persistent suppression of NFkappaB-dependent expression of CAM. The stabilization of IkappaBalpha over the same time span may be causally related to this effect.
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Affiliation(s)
- Thomas Waldow
- Herzzentrum Dresden GmbH, Universitätsklinikum Carl Gustav Carus, 01307 Dresden, Germany.
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24
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Dekker RJ, Boon RA, Rondaij MG, Kragt A, Volger OL, Elderkamp YW, Meijers JCM, Voorberg J, Pannekoek H, Horrevoets AJG. KLF2 provokes a gene expression pattern that establishes functional quiescent differentiation of the endothelium. Blood 2006; 107:4354-63. [PMID: 16455954 DOI: 10.1182/blood-2005-08-3465] [Citation(s) in RCA: 260] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The flow-responsive transcription factor KLF2 is acquiring a leading role in the regulation of endothelial cell gene expression. A genome-wide microarray expression profiling is described employing lentivirus-mediated, 7-day overexpression of human KLF2 at levels observed under prolonged flow. KLF2 is not involved in lineage typing, as 42 endothelial-specific markers were unaffected. Rather, KLF2 generates a gene transcription profile (> 1000 genes) affecting key functional pathways such as cell migration, vasomotor function, inflammation, and hemostasis and induces a morphology change typical for shear exposure including stress fiber formation. Protein levels for thrombomodulin, endothelial nitric oxide synthase, and plasminogen activator inhibitor type-1 are altered to atheroprotective levels, even in the presence of the inflammatory cytokine TNF-alpha. KLF2 attenuates cell migration by affecting multiple genes including VEGFR2 and the potent antimigratory SEMA3F. The distribution of Weibel-Palade bodies in cultured cell populations is normalized at the single-cell level without interfering with their regulated, RalA-dependent release. In contrast, thrombin-induced release of Weibel-Palade bodies is significantly attenuated, consistent with the proposed role of VWF release at low-shear stress regions of the vasculature in atherosclerosis. These results establish that KLF2 acts as a central transcriptional switch point between the quiescent and activated states of the adult endothelial cell.
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Affiliation(s)
- Rob J Dekker
- Department of Medical Biochemistry, Academic Medical Center, University of Amsterdam, Meibergdreef 15, 1105 AZ Amsterdam, The Netherlands
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25
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Bevers LM, Braam B, Post JA, van Zonneveld AJ, Rabelink TJ, Koomans HA, Verhaar MC, Joles JA. Tetrahydrobiopterin, but not L-arginine, decreases NO synthase uncoupling in cells expressing high levels of endothelial NO synthase. Hypertension 2006; 47:87-94. [PMID: 16344367 DOI: 10.1161/01.hyp.0000196735.85398.0e] [Citation(s) in RCA: 100] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Endothelial NO synthase (eNOS) produces superoxide when depleted of (6R)-5,6,7,8-tetrahydro-L-biopterin (BH4) and L-arginine by uncoupling the electron flow from NO production. High expression of eNOS has been reported to have beneficial effects in atherosclerotic arteries after relatively short periods of time. However, sustained high expression of eNOS may have disadvantageous vascular effects because of uncoupling. We investigated NO and reactive oxygen species (ROS) production in a microvascular endothelial cell line (bEnd.3) with sustained high eNOS expression and absent inducible NOS and neuronal NOS expression using 4,5-diaminofluorescein diacetate and diacetyldichlorofluorescein as probes, respectively. Unstimulated cells produced both NO and ROS. After stimulation with vascular endothelial growth factor (VEGF), NO and ROS production increased. VEGF-induced ROS production was even further increased by the addition of extra L-arginine. Nomega-nitro-L-arginine methyl ester decreased ROS production. These findings strongly suggest that eNOS is a source of ROS in these cells. Although BH4 levels were increased as compared with another endothelial cell line, eNOS levels were >2 orders of magnitude higher. The addition of BH4 resulted in increased NO production and decreased generation of ROS, indicating that bEnd.3 cells produce ROS through eNOS uncoupling because of relative BH4 deficiency. Nevertheless, eNOS-dependent ROS production was not completely abolished by the addition of BH4, suggesting intrinsic superoxide production by eNOS. This study indicates that potentially beneficial sustained increases in eNOS expression and activity could lead to eNOS uncoupling and superoxide production as a consequence. Therefore, sustained increases of eNOS or VEGF activity should be accompanied by concomitant supplementation of BH4.
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Affiliation(s)
- Lonneke M Bevers
- Department of Nephrology and Hypertension, Institute and Graduate School of Biomembranes, University Medical Centre, Utrecht, The Netherlands
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Tang EHC, Feletou M, Huang Y, Man RYK, Vanhoutte PM. Acetylcholine and sodium nitroprusside cause long-term inhibition of EDCF-mediated contractions. Am J Physiol Heart Circ Physiol 2005; 289:H2434-40. [PMID: 16040712 DOI: 10.1152/ajpheart.00568.2005] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Preliminary studies suggested that previous exposure to acetylcholine (ACh) exerts a delayed inhibition of subsequent contractions mediated by endothelium-derived contracting factor (EDCF). To confirm this long-term inhibitory effect of ACh and to determine whether nitric oxide (NO) mediates the phenomenon, we suspended rings of spontaneously hypertensive rat (SHR) aortas in organ chambers for the recording of isometric force. The rings were incubated in the absence or presence of Nω-nitro-l-arginine methyl ester (l-NAME; inhibitor of NO synthases) or 1 H-[1,2,4]oxadiazolo[4,3-α]quinoxalin-1-one (ODQ; inhibitor of soluble guanylyl cyclase) before exposure to increasing concentrations of ACh or sodium nitroprusside (SNP) during contractions to phenylephrine. Thereafter, EDCF-mediated contractions to ACh or the calcium ionophore A-23187 were elicited. If the rings were preexposed to ACh or SNP, the subsequent ACh-induced EDCF-mediated contractions were reduced compared with those obtained in rings of the same arteries not previously exposed to either agent. ODQ did not affect the inhibition caused by preexposure to ACh but significantly reduced that caused by preexposure to SNP. Previous exposure to SNP reduced, whereas previous exposure to ACh did not affect, endothelium-dependent contractions to A-23187. Previous exposure to either ACh or SNP did not affect the contractions to the thromboxane mimetic U-46619. Thus ACh and SNP exert delayed inhibition of EDCF-mediated contractions via distinct pathways. The effect of ACh is NO independent and upstream of the increase in calcium concentration that triggers the release of EDCF. The effect of SNP is downstream of the calcium rise and is mainly NO dependent.
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Affiliation(s)
- Eva H C Tang
- Dept. of Pharmacology, Univ. of Hong Kong, 2/F, Laboratory Block, Faculty of Medicine Bldg., 21 Sassoon Road, Pokfulam, Hong Kong
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Hu J, Kapoor M, Zhang W, Hamilton SR, Coombes KR. Analysis of dose-response effects on gene expression data with comparison of two microarray platforms. Bioinformatics 2005; 21:3524-9. [PMID: 16081476 DOI: 10.1093/bioinformatics/bti592] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
MOTIVATION The problems of analyzing dose effects on gene expression are gaining attention in biomedical research. A specific challenge is to detect genes with expression levels that change according to dose levels in a non-random manner, but nonetheless may be considered as potential biomarkers. METHOD We are among the first to formally apply a tool that uses an isotonic (monotonic) regression approach to this area of study. We introduce a test statistic to select genes with significant dose-response expression in a monotonic fashion based on a permutation procedure. We then compare the results with those achieved from the application of a likelihood ratio-based test. RESULTS We apply the isotonic regression approach to a study of gene expression in the RKO colon carcinoma cell line in response to varying dosage levels of the chemotherapeutic agent 5-fluorouracil. A feature of both Affymetrix and printed 75mer oligomer cDNA arrays produced from the same samples provides an opportunity to compare the two microarray platforms. AVAILABILITY Statistical software S-plus Code to implement the method is available from the authors. CONTACT kcoombes@mdanderson.org
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Affiliation(s)
- Jianhua Hu
- Department of Biostatistics and Applied Mathematics, University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
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Braam B, de Roos R, Bluyssen H, Kemmeren P, Holstege F, Joles JA, Koomans H. Nitric oxide-dependent and nitric oxide-independent transcriptional responses to high shear stress in endothelial cells. Hypertension 2005; 45:672-80. [PMID: 15699468 DOI: 10.1161/01.hyp.0000154683.33414.94] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Shear stress modulates gene expression in endothelial cells (ECs) partly through nitric oxide (NO), acting via enhanced cGMP formation by guanylyl cyclase (GC). We addressed non-cGMP-mediated transcriptional responses to shear stress in human umbilical ECs subjected to high-laminar shear stress (25 dyn/cm2; 150 minutes). RNA was isolated, reverse-transcribed, Cy3/5-labeled, and hybridized to 19 K human microarrays. High shear (n=6), high shear with 100 micromol/L L-NAME (n=3), and high shear with 10 micromol/L ODQ (GC inhibitor) in the perfusate (n=3) was compared with samples not subjected to flow. Among genes responding to high shear were HMOX1 (up) and PPARG (down). A high percentage of gene expression modulation by shear was absent during concomitant L-NAME or ODQ. Several transcriptional modulators were found (up: SOX5, SOX25, ZNF151, HOXD10; down: SOX11); a number of genes were regulated by shear and by shear with ODQ, but not regulated during L-NAME, indicating a nitric oxide synthase (NOS)-dependent, guanylyl cyclase (GC)-independent pathway. Several genes only responded to shear stress during L-NAME, others only responded to shear during ODQ. Upstream binding site analysis indicated shear stress and NO-dependent regulation of transcription via SOX5 and SOX9. Although NO importantly modulated the effect of shear stress on EC transcription, HMOX1 was consistently induced by shear stress, but not dependent on NOS or GC. Using bio-informatics software and databases, a promoter analysis identified SOX5 and SOX9 as potential, novel, shear-sensitive, and NO-dependent transcriptional regulators. The role of HMOX1 as a potential backup for NOS and the downstream role of SOXes should be explored.
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Affiliation(s)
- Branko Braam
- Department of Nephrology and Hypertension, University Medical Center, F03.226, P.O. Box 85500, 3508 GA Utrecht, The Netherlands.
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