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Abstract
Dynamic remodeling of the actin cytoskeleton is an essential feature for virtually all actin-dependent cellular processes, including cell migration, cell cycle progression, chromatin remodeling and gene expression, and even the DNA damage response. An altered actin cytoskeleton is a structural hallmark associated with numerous pathologies ranging from cardiovascular diseases to immune disorders, neurological diseases and cancer. The actin cytoskeleton in cells is regulated through the orchestrated actions of a myriad of actin-binding proteins. In this Review, we provide a brief overview of the structure and functions of the actin-monomer-binding protein profilin-1 (Pfn1) and then discuss how dysregulated expression of Pfn1 contributes to diseases associated with the cardiovascular system.
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Affiliation(s)
| | - David Gau
- Bioengineering, University of Pittsburgh
| | - Partha Roy
- Bioengineering, University of Pittsburgh.,Pathology, University of Pittsburgh, 306 Center for Bioengineering, University of Pittsburgh, 300 Technology Drive, Pittsburgh, PA 15219, USA
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Single cell morphological metrics and cytoskeletal alignment regulate VCAM-1 protein expression. Biochem Biophys Res Commun 2021; 555:160-167. [PMID: 33819746 DOI: 10.1016/j.bbrc.2021.03.129] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Accepted: 03/23/2021] [Indexed: 11/22/2022]
Abstract
In the initial stages of atherosclerosis, vascular adhesion molecule-1 (VCAM-1) is a surface protein that mediates leukocyte adhesion to the endothelium's luminal surface. VCAM-1 expression is upregulated on endothelial cells (ECs) under pro-inflammatory conditions and is known to be modulated by fluid shear stress (FSS). High, pulsatile FSS induces endothelial elongation and cytoskeletal alignment and downregulates pro-inflammatory induced VCAM-1 expression, which is associated with an athero-protective EC phenotype. In contrast, athero-prone ECs under low, oscillatory FSS fail to elongate and maintain a cobblestone morphology with random cytoskeletal alignment, while VCAM-1 expression is upregulated. Whether EC shape and cytoskeletal alignment play a role in the regulation of VCAM-1 protein expression independent of FSS has not been previously determined. The goal of this study was to determine the effect of EC morphology, specifically cell elongation and alignment, and cytoskeletal alignment on VCAM-1 protein expression using topographical micropatterning of an endothelial monolayer and single cell image analysis techniques. Elongated ECs with an aligned cytoskeleton significantly downregulated VCAM-1 protein expression in the absence of FSS compared to planar controls. In addition, linear correlations between morphological metrics and protein expression showed that actin alignment had a significantly stronger effect on VCAM-1 expression than cell elongation. Functionally, monocytic U937 cells statically adhered less on micropatterns compared to planar substrates, in a VCAM-1 dependent manner. Therefore, endothelial cellular elongation and alignment as well as cytoskeletal alignment regulate VCAM-1 protein expression and immunogenic functions to produce a less inflammatory phenotype in the absence of hemodynamic effects.
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Ludtka C, Silberman J, Moore E, Allen JB. Macrophages in microgravity: the impact of space on immune cells. NPJ Microgravity 2021; 7:13. [PMID: 33790288 PMCID: PMC8012370 DOI: 10.1038/s41526-021-00141-z] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Accepted: 02/26/2021] [Indexed: 12/18/2022] Open
Abstract
The effects of a microgravity environment on the myriad types of immune cells present within the human body have been assessed both by bench-scale simulation and suborbital methods, as well as in true spaceflight. Macrophages have garnered increased research interest in this context in recent years. Their functionality in both immune response and tissue remodeling makes them a unique cell to investigate in regards to gravisensitive effects as well as parameters of interest that could impact astronaut health. Here, we review and summarize the literature investigating the effects of microgravity on macrophages and monocytes regarding the microgravity environment simulation/generation methods, cell sources, experiment durations, and parameters of interest utilized within the field. We discuss reported findings on the impacts of microgravity on macrophage/monocyte structure, adhesion and migration, proliferation, genetic expression, cytokine secretion, and reactive oxygen species production, as well as polarization. Based on this body of data, we make recommendations to the field for careful consideration of experimental design to complement existing reports, as the multitude of disparate study methods previously published can make drawing direct comparisons difficult. However, the breadth of different testing methodologies can also lend itself to attempting to identify the most robust and consistent responses to microgravity across various testing conditions.
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Affiliation(s)
- Christopher Ludtka
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, FL, USA
| | - Justin Silberman
- Materials Science and Engineering, University of Florida, Gainesville, FL, USA
| | - Erika Moore
- Materials Science and Engineering, University of Florida, Gainesville, FL, USA
| | - Josephine B Allen
- Materials Science and Engineering, University of Florida, Gainesville, FL, USA.
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Monfoulet LE, Mercier S, Bayle D, Tamaian R, Barber-Chamoux N, Morand C, Milenkovic D. Curcumin modulates endothelial permeability and monocyte transendothelial migration by affecting endothelial cell dynamics. Free Radic Biol Med 2017; 112:109-120. [PMID: 28739530 DOI: 10.1016/j.freeradbiomed.2017.07.019] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/26/2017] [Revised: 07/10/2017] [Accepted: 07/21/2017] [Indexed: 01/16/2023]
Abstract
Curcumin is a phenolic compound that exhibits beneficial properties for cardiometabolic health. We previously showed that curcumin reduced the infiltration of immune cells into the vascular wall and prevented atherosclerosis development in mice. This study aimed to investigate the effect of curcumin on monocyte adhesion and transendothelial migration (TEM) and to decipher the underlying mechanisms of these actions. Human umbilical vein endothelial cells (HUVECs) were exposed to curcumin (0.5-1μM) for 3h prior to their activation by Tumor Necrosis Factor alpha (TNF-α). Endothelial permeability, monocyte adhesion and transendothelial migration assays were conducted under static condition and shear stress that mimics blood flow. We further investigated the impact of curcumin on signaling pathways and on the expression of genes using macroarrays. Pre-exposure of endothelial cells to curcumin reduced monocyte adhesion and their transendothelial migration in both static and shear stress conditions. Curcumin also prevented changes in both endothelial permeability and the area of HUVECs when induced by TNF-α. We showed that curcumin modulated the expression of 15 genes involved in the control of cytoskeleton and endothelial junction dynamic. Finally, we showed that curcumin inhibited NF-κB signaling likely through an antagonist interplay with several kinases as suggested by molecular docking analysis. Our findings demonstrate the ability of curcumin to reduce monocyte TEM through a multimodal regulation of the endothelial cell dynamics with a potential benefit on the vascular endothelial function barrier.
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Affiliation(s)
| | - Sylvie Mercier
- Université Clermont Auvergne, INRA, UNH, CRNH Auvergne, F-63000 Clermont-Ferrand, France
| | - Dominique Bayle
- Université Clermont Auvergne, INRA, UNH, CRNH Auvergne, F-63000 Clermont-Ferrand, France
| | - Radu Tamaian
- Research and Development Department, National Institute for Research and Development for Cryogenic and Isotopic Technologies, RO-240050 Râmnicu Vâlcea, Romania; SC Biotech Corp SRL, RO-240050 Râmnicu Vâlcea, Romania
| | - Nicolas Barber-Chamoux
- Université Clermont Auvergne, INRA, UNH, CRNH Auvergne, F-63000 Clermont-Ferrand, France; CHU Clermont-Ferrand, Service de Cardiologie, F-63000 Clermont-Ferrand, France
| | - Christine Morand
- Université Clermont Auvergne, INRA, UNH, CRNH Auvergne, F-63000 Clermont-Ferrand, France
| | - Dragan Milenkovic
- Université Clermont Auvergne, INRA, UNH, CRNH Auvergne, F-63000 Clermont-Ferrand, France
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Fong LY, Ng CT, Zakaria ZA, Baharuldin MTH, Arifah AK, Hakim MN, Zuraini A. Asiaticoside Inhibits TNF-α-Induced Endothelial Hyperpermeability of Human Aortic Endothelial Cells. Phytother Res 2015; 29:1501-8. [DOI: 10.1002/ptr.5404] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
- Lai Yen Fong
- Department of Biomedical Sciences, Faculty of Medicine and Health Sciences; Universiti Putra Malaysia; Serdang Selangor Malaysia
| | - Chin Theng Ng
- Department of Biomedical Sciences, Faculty of Medicine and Health Sciences; Universiti Putra Malaysia; Serdang Selangor Malaysia
| | - Zainul Amiruddin Zakaria
- Department of Biomedical Sciences, Faculty of Medicine and Health Sciences; Universiti Putra Malaysia; Serdang Selangor Malaysia
| | | | - Abdul Kadir Arifah
- Department of Preclinical Science, Faculty of Veterinary Medicine; Universiti Putra Malaysia; Serdang Selangor Malaysia
| | - Muhammad Nazrul Hakim
- Department of Biomedical Sciences, Faculty of Medicine and Health Sciences; Universiti Putra Malaysia; Serdang Selangor Malaysia
| | - Ahmad Zuraini
- Department of Biomedical Sciences, Faculty of Medicine and Health Sciences; Universiti Putra Malaysia; Serdang Selangor Malaysia
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Regulation of ICAM-1 in cells of the monocyte/macrophage system in microgravity. BIOMED RESEARCH INTERNATIONAL 2015; 2015:538786. [PMID: 25654110 PMCID: PMC4309248 DOI: 10.1155/2015/538786] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/14/2014] [Revised: 09/22/2014] [Accepted: 10/09/2014] [Indexed: 01/03/2023]
Abstract
Cells of the immune system are highly sensitive to altered gravity, and the monocyte as well as the macrophage function is proven to be impaired under microgravity conditions. In our study, we investigated the surface expression of ICAM-1 protein and expression of ICAM-1 mRNA in cells of the monocyte/macrophage system in microgravity during clinostat, parabolic flight, sounding rocket, and orbital experiments. In murine BV-2 microglial cells, we detected a downregulation of ICAM-1 expression in clinorotation experiments and a rapid and reversible downregulation in the microgravity phase of parabolic flight experiments. In contrast, ICAM-1 expression increased in macrophage-like differentiated human U937 cells during the microgravity phase of parabolic flights and in long-term microgravity provided by a 2D clinostat or during the orbital SIMBOX/Shenzhou-8 mission. In nondifferentiated U937 cells, no effect of microgravity on ICAM-1 expression could be observed during parabolic flight experiments. We conclude that disturbed immune function in microgravity could be a consequence of ICAM-1 modulation in the monocyte/macrophage system, which in turn could have a strong impact on the interaction with T lymphocytes and cell migration. Thus, ICAM-1 can be considered as a rapid-reacting and sustained gravity-regulated molecule in mammalian cells.
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Duan J, Yu Y, Yu Y, Li Y, Huang P, Zhou X, Peng S, Sun Z. Silica nanoparticles enhance autophagic activity, disturb endothelial cell homeostasis and impair angiogenesis. Part Fibre Toxicol 2014; 11:50. [PMID: 25266717 PMCID: PMC4193984 DOI: 10.1186/s12989-014-0050-8] [Citation(s) in RCA: 96] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2014] [Accepted: 09/02/2014] [Indexed: 11/30/2022] Open
Abstract
Background Given that the effects of ultrafine fractions (<0.1 μm) on ischemic heart diseases (IHD) and other cardiovascular diseases are gaining attention, this study is aimed to explore the influence of silica nanoparticles (SiNPs)-induced autophagy on endothelial cell homeostasis and angiogenesis. Methods and results Ultrastructural changes of autophagy were observed in both vascular endothelial cells and pericytes in the heart of ICR mice by TEM. Autophagic activity and impaired angiogenesis were further confirmed by the immunohistochemistry staining of LC3 and VEGFR2. In addition, the immunohistochemistry results showed that SiNPs had an inhibitory effect on ICAM-1 and VCAM-1, but no obvious effect on E-selectin in vivo. The disruption of F-actin cytoskeleton occurred as an initial event in SiNPs-treated endothelial cells. The depolarized mitochondria, autophagic vacuole accumulation, LC3-I/LC3-II conversion, and the down-regulation of cellular adhesion molecule expression were all involved in the disruption of endothelial cell homeostasis in vitro. Western blot analysis indicated that the VEGFR2/PI3K/Akt/mTOR and VEGFR2/MAPK/Erk1/2/mTOR signaling pathway was involved in the cardiovascular toxicity triggered by SiNPs. Moreover, there was a crosstalk between the VEGFR2-mediated autophagy signaling and angiogenesis signaling pathways. Conclusions In summary, the results demonstrate that SiNPs induce autophagic activity in endothelial cells and pericytes, subsequently disturb the endothelial cell homeostasis and impair angiogenesis. The VEGFR2-mediated autophagy pathway may play a critical role in maintaining endothelium and vascular homeostasis. Our findings may provide experimental evidence and explanation for cardiovascular diseases triggered by nano-sized particles. Electronic supplementary material The online version of this article (doi:10.1186/s12989-014-0050-8) contains supplementary material, which is available to authorized users.
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Affiliation(s)
| | | | | | | | | | | | | | - Zhiwei Sun
- School of Public Health, Capital Medical University, Beijing 100069, P,R, China.
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Benslimane-Ahmim Z, Poirier F, Delomenie C, Lokajczyk A, Grelac F, Galy-Fauroux I, Mohamedi A, Fischer AM, Heymann D, Lutomski D, Boisson-Vidal C. Mechanistic study of the proangiogenic effect of osteoprotegerin. Angiogenesis 2013; 16:575-93. [PMID: 23386104 DOI: 10.1007/s10456-013-9337-x] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2012] [Accepted: 01/25/2013] [Indexed: 10/27/2022]
Abstract
Osteoprotegerin (OPG), a soluble tumour necrosis factor receptor superfamily member, inhibits RANKL-mediated osteoclastogenesis. We have previously reported that OPG enhances the proangiogenic properties of endothelial colony-forming cells (ECFCs) in vitro, and promotes vasculogenesis in vivo. Here we investigated how OPG promotes neovascularisation. Proteomic experiments showed that OPG pretreatment affected ECFCs protein expression in two ways, 23 spots being down-regulated and 6 upregulated. These spots corresponded to proteins involved in cell motility, adhesion, signal transduction and apoptosis. In keeping with these proteomic results, we found that OPG induced ECFCs adhesion to activated endothelium in shear stress conditions, promoting intermediate but not focal adhesion to fibronectin and collagen. Treatment with OPG induced a reorganization of the ECFCs cytoskeleton, with the emergence of cell protrusions characteristic of a migratory phenotype. These effects correlated with decreased FAK phosphorylation and enhanced integrin αVβ3 expression. OPG drastically reduced caspase-3/7 activities and maintained ECFCs viability after 48 h of treatment. All these effects were significantly attenuated by ECFCs incubation with the CXCR4 antagonist AMD-3100, and by prior heparan sulphate proteoglycan disruption. The proangiogenic properties of OPG appeared to be mediated by the proteoglycan syndecan-1, although OPG 1-194 lacking its heparin-binding domain still had pro-vasculogenic effects in vitro and in vivo. These results suggest that OPG may interact with ECFCs by binding to HSPGs/syndecan-1, thereby induce an anti-adhesive effect and promoting ECFCs migration through a SDF-1/CXCR4 dependent pathway.
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Membrane-bound form of monocyte chemoattractant protein-1 enhances antitumor effects of suicide gene therapy in a model of hepatocellular carcinoma. Cancer Gene Ther 2012; 19:312-9. [PMID: 22402625 DOI: 10.1038/cgt.2012.3] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Suicide gene therapy using the herpes simplex virus thymidine kinase/ganciclovir (HSV-tk/GCV) system combined with monocyte chemoattractant protein-1 (MCP-1) provides significant antitumor efficacy. The current study was designed to evaluate the antitumor immunity of a newly developed membrane-bound form of MCP-1 (mMCP-1) in an immunocompetent mouse model of hepatocellular carcinoma (HCC). A recombinant adenovirus vector (rAd) harboring the human MCP-1 gene and the membrane-spanning domain of the CX3CL1 gene was used. Large amounts of MCP-1 protein were expressed and accumulated on the tumor cell surface. The growth of subcutaneous tumors was markedly suppressed when tumors were treated with mMCP-1, as compared with soluble MCP-1, in combination with the HSV-tk/GCV system (P<0.01). The numbers of Mac-1-, CD4- and CD8a-positive cells were significantly higher in tumor tissues (P<0.05), and tumor necrosis factor (TNF) mRNA expression levels with mMCP-1 were almost five-fold higher than those with soluble MCP-1. These results indicate that the delivery of the mMCP-1 gene greatly enhanced antitumor effects following the apoptotic stimuli by promoting the recruitment and activation of macrophages and T lymphocytes, suggesting a novel strategy of immune-based gene therapy in the treatment of patients with HCC.
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Urschel K, Garlichs CD, Daniel WG, Cicha I. VEGFR2 signalling contributes to increased endothelial susceptibility to TNF-α under chronic non-uniform shear stress. Atherosclerosis 2011; 219:499-509. [PMID: 22019447 DOI: 10.1016/j.atherosclerosis.2011.09.045] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/19/2011] [Revised: 09/04/2011] [Accepted: 09/27/2011] [Indexed: 01/19/2023]
Abstract
OBJECTIVES Vascular endothelial growth factor receptor 2 (VEGFR2), a tyrosine kinase receptor activated by VEGF and shear stress, is critically involved in endothelial mechanotransduction. We investigated the role of VEGFR2 in non-uniform shear stress-induced endothelial susceptibility to inflammatory stimuli. METHODS Endothelial cells (ECs) were exposed to non-uniform shear stress, followed by stimulation with TNF-α. ECs were transfected with siRNAs against VEGFR2. Alternatively, ECs were treated with blocking antibody against VEGFR2, or with inhibitors of VEGFR2 (ZM 323881), PI3K (LY 294002), or Src-kinase (PP2). THP-1 monocytes were used for dynamic adhesion assays. Endothelial protein expression was determined by immunofluorescence. RESULTS siRNA against VEGFR2 decreased VEGFR2 protein expression by 40% as determined by Western blotting. In endothelial cells exposed to non-uniform shear stress, VEGFR2 knockdown inhibited TNF-α-induced NF-κB translocation to the nucleus, and the upregulation of VCAM-1 and E-selectin. Consequently, monocytic cell recruitment to endothelium under non-uniform shear stress conditions was reduced. Similar effects were observed by blocking VEGFR2 activity using a specific inhibitor ZM 323881, or an antibody against VEGFR2 before TNF-α stimulation. Inhibition of PI3K with LY 294002 significantly reduced non-uniform shear stress-induced endothelial susceptibility to TNF-α, whereas blocking Src-kinase with PP2 was ineffective. CONCLUSION VEGFR2 is critically involved in adhesion molecule induction and monocytic cell recruitment to endothelium in response to non-uniform shear stress and TNF-α. Targeting the mechanosensory cascade can prevent endothelial activation in atherosclerosis-prone regions.
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Affiliation(s)
- Katharina Urschel
- Department of Cardiology and Angiology, University of Erlangen-Nuremberg, Erlangen, Germany
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Wang YL, Kuo JH, Lee SC, Liu JS, Hsieh YC, Shih YT, Chen CJ, Chiu JJ, Wu WG. Cobra CRISP functions as an inflammatory modulator via a novel Zn2+- and heparan sulfate-dependent transcriptional regulation of endothelial cell adhesion molecules. J Biol Chem 2010; 285:37872-83. [PMID: 20889969 DOI: 10.1074/jbc.m110.146290] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Cysteine-rich secretory proteins (CRISPs) have been identified as a toxin family in most animal venoms with biological functions mainly associated with the ion channel activity of cysteine-rich domain (CRD). CRISPs also bind to Zn(2+) at their N-terminal pathogenesis-related (PR-1) domain, but their function remains unknown. Interestingly, similar the Zn(2+)-binding site exists in all CRISP family, including those identified in a wide range of organisms. Here, we report that the CRISP from Naja atra (natrin) could induce expression of vascular endothelial cell adhesion molecules, i.e. intercellular adhesion molecule-1, vascular adhesion molecule-1, and E-selectin, to promote monocytic cell adhesion in a heparan sulfate (HS)- and Zn(2+)-dependent manner. Using specific inhibitors and small interfering RNAs, the activation mechanisms are shown to involve both mitogen-activated protein kinases and nuclear factor-κB. Biophysical characterization of natrin by using fluorescence, circular dichroism, and x-ray crystallographic methods further reveals the presence of two Zn(2+)-binding sites for natrin. The strong binding site is located near the putative Ser-His-Glu catalytic triad of the N-terminal domain. The weak binding site remains to be characterized, but it may modulate HS binding by enhancing its interaction with long chain HS. Our results strongly suggest that natrin may serve as an inflammatory modulator that could perturb the wound-healing process of the bitten victim by regulating adhesion molecule expression in endothelial cells. Our finding uncovers a new aspect of the biological role of CRISP family in immune response and is expected to facilitate future development of new therapeutic strategy for the envenomed victims.
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Affiliation(s)
- Yu-Ling Wang
- From the Institute of Bioinformatics and Structural Biology, National Tsing Hua University, Hsinchu 30013, Taiwan
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von Wedel-Parlow M, Schrot S, Lemmen J, Treeratanapiboon L, Wegener J, Galla HJ. Neutrophils cross the BBB primarily on transcellular pathways: an in vitro study. Brain Res 2010; 1367:62-76. [PMID: 20875807 DOI: 10.1016/j.brainres.2010.09.076] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2010] [Accepted: 09/21/2010] [Indexed: 01/13/2023]
Abstract
The cerebral microcapillary endothelium forms a highly important barrier between the blood and the interstitial fluid of the brain (blood-brain barrier) that controls the passage of molecules and cells in and out of the CNS. Several CNS diseases include leukocyte extravasation through the endothelium via two mechanistically distinct routes, the paracellular and the transcellular pathway. We established a new in vitro model of the inflamed blood-brain barrier consisting of primary cultured porcine brain capillary endothelial cells which express a tight endothelial barrier even under inflammatory conditions. By means of this specialized blood-brain barrier model we extensively studied the transmigration of neutrophils. Electron and scanning force microscopy as well as immunofluorescence imaging captured the penetrating neutrophil on the endothelial cellular body in between the junctions clearly suggesting a transcellular migration pathway. Electric cell-substrate impedance sensing and transendothelial electrical resistance measurements in combination with expression analysis of tight junction proteins demonstrate that the neutrophil-endothelial interaction does not disrupt the barrier. In conclusion, this study, based on an in vitro model of the blood-brain barrier under inflammatory conditions, evidently implicates that neutrophils preferentially migrate across the BBB via the transcellular route without impairing endothelial barrier function whereas paracellular transmigration plays only a minor role if the barrier is strongly expressed.
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Affiliation(s)
- Magdalena von Wedel-Parlow
- Institut für Biochemie, Westfälische Wilhelms-Universität Münster, Wilhelm-Klemm-Straße 2, D-48149 Münster, Germany
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Paclitaxel potentiates inflammatory cytokine-induced prothrombotic molecules in endothelial cells. J Cardiovasc Pharmacol 2010; 55:276-85. [PMID: 20075745 DOI: 10.1097/fjc.0b013e3181d263f7] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
To overcome the limitations of balloon expandible metal stent-induced neointimal smooth muscle cell proliferation, drug-coated stent devices have been developed. Drug eluting stents release high concentrations of antiproliferative agents, such as paclitaxel, to reduce neointimal hyperplasia. The proinflammatory cytokine, tumor necrosis factor-alpha (TNF-alpha), is known to cause severe endothelial dysfunction and accelerate atherosclerotic lesion progression. The interaction of TNF-alpha and paclitaxel on the release of prothrombotic molecules was examined in endothelial cells. Treatment of endothelial cells with paclitaxel had no direct effect on tissue factor (TF) expression, but TNF-alpha increased TF. Cotreatment of paclitaxel with TNF-alpha markedly augmented the release of TF. TNF-alpha induced release of plasminogen activator inhibitor but no synergism occurred with paclitaxel. Treatment of endothelial cells with paclitaxel and TNF-alpha reduced expression of thrombomodulin and protein C receptor. Tissue factor pathway inhibitor expression was reduced by prolonged treatment with either paclitaxel or TNF-alpha. The adhesion molecule, CD62 E, was induced by TNF-alpha; however, CD31, CD62 P, and CD106 were not affected by paclitaxel and TNF-alpha. Apoptosis was not observed with cotreatment of endothelial cells with paclitaxel and TNF-alpha. CD59-positive microparticles were released in response to TNF-alpha, but the release was not augmented by paclitaxel. Paclitaxel and TNF-alpha increased the nitrotyrosination of proteins. These findings indicate that paclitaxel enhances TNF-alpha-induced release of TF, and downregulated thrombomodulin, increased protein nitration, which may subsequently favor prothrombotic intimal surface.
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Song Y, Fullerton DA, Mauchley D, Su X, Ao L, Yang X, Cleveland JC, Meng X. Microfilaments facilitate TLR4-mediated ICAM-1 expression in human aortic valve interstitial cells. J Surg Res 2009; 166:52-8. [PMID: 19691982 DOI: 10.1016/j.jss.2009.03.101] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2009] [Revised: 03/03/2009] [Accepted: 03/13/2009] [Indexed: 10/20/2022]
Abstract
BACKGROUND Inflammation is involved in the pathogenesis of calcific aortic valve stenosis, and aortic valve interstitial cells (AVICs) play an important role in valve disease and remodeling. We have previously shown that human AVICs express functional toll-like receptor 4 (TLR4), and express increased levels of ICAM-1 in response to stimulation with bacterial lipopolysaccharide (LPS). This study examines (1) the role of TLR4 in regulating ICAM-1 expression in human AVICs, (2) the interaction of ICAM-1 with microfilaments, and (3) the influence of microfilament integrity on ICAM-1 expression. MATERIALS AND METHODS AVICs isolated from explanted human hearts were stimulated with LPS (0.2 μg/mL) to induce ICAM-1 expression, as shown by Western blot. TLR4 activity was influenced with a neutralizing antibody or by gene knockdown with siRNA. Flow cytometry and immunofluorescence were used to characterize membrane localization of ICAM-1. Immunoprecipitation and immunofluorescence were employed to show colocalization of ICAM-1 with microfilaments. Microfilament function was influenced with an actin polymerization inhibitor as well as siRNA. RESULTS Cellular ICAM-1 levels increased 10-fold after 24 h of LPS stimulation, and this increase was significantly attenuated by prior treatment with TLR4-neutralizing antibody or TLR4 siRNA. ICAM-1 exhibited a filamentous distribution pattern after 4 h LPS stimulation, which was associated with increased total and cell-surface ICAM-1 expression. ICAM-1 colocalized and coprecipitated with the microfilament proteins F-actin and α-actinin 1. Pretreatment with the actin polymerization inhibitor latrunculin B and silencing α-actinin 1 with siRNA reduced LPS-induced total and cell-surface ICAM-1 expression. CONCLUSIONS This study demonstrates that (1) LPS-stimulated ICAM-1 expression in human AVICs is mediated by TLR4, (2) ICAM-1 interacts with microfilaments soon after LPS stimulation, and (3) microfilament disruption reduces ICAM-1 expression. These results suggest that the interaction between ICAM-1 and microfilaments facilitates LPS-induced ICAM-1 expression in human AVICs.
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Affiliation(s)
- Yong Song
- Department of Surgery, Division of Cardiothoracic Surgery, University of Colorado-Denver, Aurora, Colorado 80045, USA
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Kakiashvili E, Speight P, Waheed F, Seth R, Lodyga M, Tanimura S, Kohno M, Rotstein OD, Kapus A, Szászi K. GEF-H1 mediates tumor necrosis factor-alpha-induced Rho activation and myosin phosphorylation: role in the regulation of tubular paracellular permeability. J Biol Chem 2009; 284:11454-66. [PMID: 19261619 DOI: 10.1074/jbc.m805933200] [Citation(s) in RCA: 82] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Tumor necrosis factor-alpha (TNF-alpha), an inflammatory cytokine, has been shown to activate the small GTPase Rho, but the underlying signaling mechanisms remained undefined. This general problem is particularly important in the kidney, because TNF-alpha, a major mediator of kidney injury, is known to increase paracellular permeability in tubular epithelia. Here we aimed to determine the effect of TNF-alpha on the Rho pathway in tubular cells (LLC-PK(1) and Madin-Darby canine kidney), define the upstream signaling, and investigate the role of the Rho pathway in the TNF-alpha-induced alterations of paracellular permeability. We show that TNF-alpha induced a rapid and sustained RhoA activation that led to stress fiber formation and Rho kinase-dependent myosin light chain (MLC) phosphorylation. To identify new regulators connecting the TNF receptor to Rho signaling, we applied an affinity precipitation assay with a Rho mutant (RhoG17A), which captures activated GDP-GTP exchange factors (GEFs). Mass spectrometry analysis of the RhoG17A-precipitated proteins identified GEF-H1 as a TNF-alpha-activated Rho GEF. Consistent with a central role of GEF-H1, its down-regulation by small interfering RNA prevented the activation of the Rho pathway. Moreover GEF-H1 and Rho activation are downstream of ERK signaling as the MEK1/2 inhibitor PD98059 mitigated TNF-alpha-induced activation of these proteins. Importantly TNF-alpha enhanced the ERK pathway-dependent phosphorylation of Thr-678 of GEF-H1 that was key for activation. Finally the TNF-alpha-induced paracellular permeability increase was absent in LLC-PK(1) cells stably expressing a non-phosphorylatable, dominant negative MLC. In summary, we have identified the ERK/GEF-H1/Rho/Rho kinase/phospho-MLC pathway as the mechanism mediating TNF-alpha-induced elevation of tubular epithelial permeability, which in turn might contribute to kidney injury.
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Affiliation(s)
- Eli Kakiashvili
- Keenan Research Centre in the Li Ka Shing Knowledge Institute, St. Michael's Hospital and Department of Surgery, University of Toronto, Ontario M5B 1W8, Canada
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16
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Chen HW, Lii CK, Ku HJ, Wang TS. Cigarette smoke extract induces expression of cell adhesion molecules in HUVEC via actin filament reorganization. ENVIRONMENTAL AND MOLECULAR MUTAGENESIS 2009; 50:96-104. [PMID: 19107907 DOI: 10.1002/em.20441] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Epidemiologic studies have shown a strong association between cigarette smoking and cardiovascular diseases. Various oxidative species and free radicals are produced during cigarette smoking and these lead to endothelial dysfunction and inflammation. Expression of adhesion molecules, such as intercellular adhesion molecule-1 (ICAM-1), E-selectin, and vascular cell adhesion molecule-1, and adhesion of leukocytes are present in atherosclerosis. We showed previously that a nonfractionated cigarette smoke extract (CSE) induces surface expression of ICAM-1 and E-selectin in human umbilical vein endothelial cells (HUVEC). We then investigated the role of the MAPKs (ERK1/2, JNK, and p38) and AP-1 and the role of actin cytoskeleton reorganization in the CSE-induced expression of ICAM-1 and E-selectin. Western blot analysis showed that CSE treatment rapidly and significantly caused phosphorylation of JNK and ERK1/2 but not of p38. Cytochalasin D (an actin filament disruptor) partially inhibited CSE-induced ICAM-1 and E-selectin surface expression. However, inhibitors of ERK1/2 (PD98059) and JNK (SP600125) did not attenuate the CSE-induced ICAM-1 and E-selectin surface expression. The results of electrophoretic mobility shift assay showed that CSE enhanced AP-1 binding activity. Therefore, CSE activated AP-1 and upregulated ICAM-1 and E-selectin surface expression in HUVEC seem to be via an MAPK-independent pathway. Moreover, the dynamic reorganization of the actin cytoskeleton seems to be required for the CSE-induced surface expression of ICAM-1 and E-selectin.
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Affiliation(s)
- Haw-Wen Chen
- Department of Nutrition, China Medical University, Taichung, Taiwan
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ten Hagen TLM, Seynhaeve ALB, Eggermont AMM. Tumor necrosis factor-mediated interactions between inflammatory response and tumor vascular bed. Immunol Rev 2009; 222:299-315. [PMID: 18364010 DOI: 10.1111/j.1600-065x.2008.00619.x] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Solid tumor therapy with chemotherapeutics greatly depends on the efficiency with which drugs are delivered to tumor cells. The typical characteristics of the tumor physiology promote but also appose accumulation of blood-borne agents. The leaky tumor vasculature allows easy passage of drugs. However, the disorganized vasculature causes heterogeneous blood flow, and together with the often-elevated interstitial fluid pressure, this state results in poor intratumoral drug levels and failure of treatment. Manipulation of the tumor vasculature could overcome these barriers and promote drug delivery. Targeting the vasculature has several advantages. The endothelial lining is readily accessible and the first to be encountered after systemic injection. Second, endothelial cells tend to be more stable than tumor cells and thus less likely to develop resistance to therapy. Third, targeting the tumor vasculature can have dual effects: (i) manipulation of the vasculature can enhance concomitant chemotherapy, and (ii) subsequent destruction of the vasculature can help to kill the tumor. In particular, tumor necrosis factor alpha is studied. Its action on solid tumors, both directly through tumor cell killing and destruction of the tumor vasculature and indirectly through manipulation of the tumor physiology, is complex. Understanding the mechanism of TNF and agents with comparable action on solid tumors is an important focus to further develop combination immunotherapy strategies.
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Affiliation(s)
- Timo L M ten Hagen
- Department of Surgical Oncology, Erasmus MC-Daniel den Hoed Cancer Center, Rotterdam, The Netherlands.
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Chapter 5 Cytoskeletal Interactions with Leukocyte and Endothelial Cell Adhesion Molecules. CURRENT TOPICS IN MEMBRANES 2009. [DOI: 10.1016/s1063-5823(09)64005-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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19
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Sandoval KE, Witt KA. Blood-brain barrier tight junction permeability and ischemic stroke. Neurobiol Dis 2008; 32:200-19. [PMID: 18790057 DOI: 10.1016/j.nbd.2008.08.005] [Citation(s) in RCA: 739] [Impact Index Per Article: 46.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2008] [Revised: 07/29/2008] [Accepted: 08/10/2008] [Indexed: 01/01/2023] Open
Abstract
The blood-brain barrier (BBB) is formed by the endothelial cells of cerebral microvessels, providing a dynamic interface between the peripheral circulation and the central nervous system. The tight junctions (TJs) between the endothelial cells serve to restrict blood-borne substances from entering the brain. Under ischemic stroke conditions decreased BBB TJ integrity results in increased paracellular permeability, directly contributing to cerebral vasogenic edema, hemorrhagic transformation, and increased mortality. This loss of TJ integrity occurs in a phasic manner, which is contingent on several interdependent mechanisms (ionic dysregulation, inflammation, oxidative and nitrosative stress, enzymatic activity, and angiogenesis). Understanding the inter-relation of these mechanisms is critical for the development of new therapies. This review focuses on those aspects of ischemic stroke impacting BBB TJ integrity and the principle regulatory pathways, respective to the phases of paracellular permeability.
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Affiliation(s)
- Karin E Sandoval
- Department of Pharmaceutical Sciences, School of Pharmacy, Southern Illinois University Edwardsville, Edwardsville, IL 62026, USA
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20
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Mawaribuchi S, Tamura K, Okano S, Takayama S, Yaoita Y, Shiba T, Takamatsu N, Ito M. Tumor necrosis factor-alpha attenuates thyroid hormone-induced apoptosis in vascular endothelial cell line XLgoo established from Xenopus tadpole tails. Endocrinology 2008; 149:3379-89. [PMID: 18403482 DOI: 10.1210/en.2007-1591] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Amphibian metamorphosis induced by T(3) involves programmed cell death and the differentiation of various types of cells in degenerated and reconstructed tissues. However, the signaling pathway that directs the T(3)-dependent cell-fate determinations remains unclear. TNF-alpha is a pleiotropic cytokine that affects diverse cellular responses. Engagement of TNF-alpha with its receptor (TNFR1) causes intracellular apoptotic and/or survival signaling. To investigate TNF signaling functions during anuran metamorphosis, we first identified Xenopus laevis orthologs of TNF (xTNF)-alpha and its receptor. We found that xTNF-alpha activated nuclear factor-kappaB in X. laevis A6 cells through the Fas-associated death domain and receptor-interacting protein 1. Interestingly, xTNF-alpha mRNA in blood cells showed prominent expression at prometamorphosis during metamorphosis. Next, to elucidate the apoptotic and/or survival signaling induced by xTNF-alpha in an in vitro model of metamorphosis, we established a vascular endothelial cell line, XLgoo, from X. laevis tadpole tail. XLgoo cells formed actin stress fibers and elongated in response to xTNF-alpha. T(3) induced apoptosis in these cells, but the addition of xTNF-alpha blocked the T(3)-induced apoptosis. In addition, treatment of the cells with T(3) for 2 d induced the expression of thyroid hormone receptor-beta and caspase-3, and this thyroid hormone receptor-beta induction was drastically repressed by xTNF-alpha. Furthermore, in organ culture of the tail, xTNF-alpha significantly attenuated the tail degeneration induced by T(3). These findings suggested that xTNF-alpha could protect vascular endothelial cells from apoptotic cell death induced by T(3) during metamorphosis and thereby participate in the regulation of cell fate.
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Affiliation(s)
- Shuuji Mawaribuchi
- Department of Biosciences, School of Science, Kitasato University, 1-15-1 Kitasato, Sagamihara, Japan
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McKenzie JAG, Ridley AJ. Roles of Rho/ROCK and MLCK in TNF-alpha-induced changes in endothelial morphology and permeability. J Cell Physiol 2007; 213:221-8. [PMID: 17476691 DOI: 10.1002/jcp.21114] [Citation(s) in RCA: 204] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Tumor necrosis factor-alpha (TNF-alpha) is known to induce changes in endothelial cell morphology and permeability, but the mechanisms have not been extensively characterized. TNF-alpha rapidly induced RhoA activation and myosin light chain phosphorylation, but caused only small changes to cortical F-actin, without significantly increasing paracellular permeability up to 30 min after stimulation. TNF-alpha subsequently caused a progressive increase in permeability and in stress fiber reorganization, cell elongation, and intercellular gap formation over 8-24 h. Consistent with the increased permeability, Occludin and JAM-A were removed from tight junctions and ZO-1 was partially redistributed. Rho/ROCK but not MLCK inhibition prevented the long-term TNF-alpha-induced changes in F-actin and cell morphology, but ROCK inhibition did not affect permeability. These results suggest that the gradual increase in permeability induced by TNF-alpha does not reflect contractile mechanisms mediated by Rho, ROCK, and MLCK, but involves long-term reorganization of tight junction proteins.
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Affiliation(s)
- Jenny A G McKenzie
- Ludwig Institute for Cancer Research, Royal Free and University College School of Medicine, London, United Kingdom
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Paez A, Rodriguez E, Rendon E, Varela E, Fortoul T, Espinosa B, Masso F, Guevara J, Montaño LF. Altered detection of molecules associated with leukocyte traffic in HUVECs derived from newborns with a strong family history of myocardial infarction. Acta Histochem 2007; 110:42-52. [PMID: 17765294 DOI: 10.1016/j.acthis.2007.05.007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2007] [Revised: 05/17/2007] [Accepted: 05/22/2007] [Indexed: 01/21/2023]
Abstract
Atherosclerosis is a chronic inflammatory disease. As such, recruitment of immune cells is a significant event. Tightly controlled signaling molecules regulate leukocyte adhesion and migration to the tissues. The aim of this study was to determine if human umbilical vein endothelial cells (HUVECs) derived from healthy newborns with a strong family history of myocardial infarction (FHMI) showed variations in the presence of molecules related with leukocyte traffic and migration, in comparison to control healthy newborns. For this purpose, we evaluated the labeling of sialic acid containing glycoproteins, tight junction claudins and the cytoskeleton, using lectin- and immunocytochemistry in HUVECs from individuals with and without a strong FHMI. Our results show important differences in the labeling of alpha-2,3 or alpha-2,6 sialic acid-containing glycoconjugates, a disarrangement of actin filaments secondary to the absence of cytoplasmic claudin-5 immunopositivity and an increase in the binding of FHMI HUVECs to CD3+ Jurkat cells. It is possible that these differences relate to a predisposition for early appearance of atherosclerotic lesions.
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Affiliation(s)
- Araceli Paez
- Departamento Biología Celular, Instituto Nacional de Cardiología Ignacio Chávez, Juan Badiano 1, Col. Seccion 16, México 14080, México
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23
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Fazal F, Minhajuddin M, Bijli KM, McGrath JL, Rahman A. Evidence for actin cytoskeleton-dependent and -independent pathways for RelA/p65 nuclear translocation in endothelial cells. J Biol Chem 2006; 282:3940-50. [PMID: 17158457 DOI: 10.1074/jbc.m608074200] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Activation of the transcription factor NF-kappaB involves its release from the inhibitory protein IkappaBalpha in the cytoplasm and subsequently, its translocation to the nucleus. Whereas the events responsible for its release have been elucidated, mechanisms regulating the nuclear transport of NF-kappaB remain elusive. We now provide evidence for actin cytoskeleton-dependent and -independent mechanisms of RelA/p65 nuclear transport using the proinflammatory mediators, thrombin and tumor necrosis factor alpha, respectively. We demonstrate that thrombin alters the actin cytoskeleton in endothelial cells and interfering with these alterations, whether by stabilizing or destabilizing the actin filaments, prevents thrombin-induced NF-kappaB activation and consequently, expression of its target gene, ICAM-1. The blockade of NF-kappaB activation occurs downstream of IkappaBalpha degradation and is associated with impaired RelA/p65 nuclear translocation. Importantly, thrombin induces association of RelA/p65 with actin and this interaction is sensitive to stabilization/destabilization of the actin filaments. In parallel studies, stabilizing or destabilizing the actin filaments fails to inhibit RelA/p65 nuclear accumulation and ICAM-1 expression by tumor necrosis factor alpha, consistent with its inability to induce actin filament formation comparable with thrombin. Thus, these studies reveal the existence of actin cytoskeleton-dependent and -independent pathways that may be engaged in a stimulus-specific manner to facilitate RelA/p65 nuclear import and thereby ICAM-1 expression in endothelial cells.
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Affiliation(s)
- Fabeha Fazal
- Department of Pediatrics, University of Rochester School of Medicine and Dentistry, Rochester, New York 14642, USA
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Chen Y, Girdhar G, Shao JY. Single membrane tether extraction from adult and neonatal dermal microvascular endothelial cells. Am J Physiol Cell Physiol 2006; 292:C1272-9. [PMID: 17079334 DOI: 10.1152/ajpcell.00251.2006] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Membrane tethers were found to be extracted from leukocytes and macrovascular endothelial cells (e.g., human umbilical vein endothelial cells or HUVECs) when a point pulling force was exerted. These tethers stabilize leukocyte rolling on the endothelium during the inflammatory response. However, little is known about tether extraction from other vascular cells like microvascular endothelial cells (MECs). In this study, we extracted tethers from both adult and neonatal dermal MECs with the micropipette aspiration technique. We found a linear relationship between the pulling force and tether growth velocity for both cell lines. This constitutive relationship is mainly determined by the membrane mechanical property and the underlying actin-based cytoskeleton for both attached and suspended endothelial cells. It is independent of cell surface receptor type, attachment state, cytokine stimulation, or cell lineage. For both types of MECs, the threshold forces are approximately 50 pN and the effective viscosities are around 0.5 pN x s/microm. These results, which are close to what was obtained from HUVECs, indicate that homogeneity is preserved in terms of tether extraction among different types of endothelial cells, and simultaneous tethers are likely extracted when leukocytes roll on either microvascular or macrovascular surfaces.
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Affiliation(s)
- Yong Chen
- Department of Biomedical Engineering, Washington University, Saint Louis, Missouri 63130, USA
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25
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Paez A, Méndez-Cruz AR, Varela E, Rodriguez E, Guevara J, Flores-Romo L, Montaño LF, Massó FA. HUVECs from newborns with a strong family history of myocardial infarction overexpress adhesion molecules and react abnormally to stimulating agents. Clin Exp Immunol 2005; 141:449-58. [PMID: 16045734 PMCID: PMC1809470 DOI: 10.1111/j.1365-2249.2005.02858.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/04/2005] [Indexed: 01/24/2023] Open
Abstract
Atherosclerosis is a complex disease involved in major fatal events such as myocardial infarction and stroke. It is the result of interactions between metabolic, dietetic and environmental risk factors acting on a genetic background that could result in endothelial susceptibility. Our aim was to determine the patterns of expression of adhesion molecules and whether phosphatidylserine is translocated to the cell surface of human umbilical vein endothelial cells (HUVECs) isolated from healthy newborns born to parents with a strong family history of myocardial infarction under TNF-alpha or oxLDL stimulated conditions. Compared to control HUVECs, experimental cords showed: (a) a four-fold increase in VCAM-1 expression under basal conditions, which showed no change after stimulation with the pro-atherogenic factors; (b) a two-fold increase in basal P-selectin expression that reached a 10-fold increase with any of the pro-atherogenic factors; (c) a basal ICAM-1 expression similar to P-selectin that was not modified by the pro-atherogenic molecules; (d) a similar PECAM-1 expression. Unexpectedly, phospathidylserine expression in experimental cord HUVECs was significantly increased (211 817 versus 3354 TFU) but was not associated to apoptotic death as the percentage of dead cells induced by TNF-alpha treatment was very low (0.55 versus 9.87% in control HUVECs). The latter result was corroborated by TUNEL staining. T cell adherence to HUVECs was highly up-regulated in the genetically predisposed samples. The analysis of nonpooled HUVECs, from newborns to family predisposed myocardial-infarction individuals, might represent a useful strategy to identify phenotypical and functional alterations, and hopefully, to take early preventive actions.
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Affiliation(s)
- A Paez
- Depto. Biología Celular, Instituto Nacional de Cardiología Ignacio Chávez, Tlalpan, Mexico
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Zhao T, Bokoch GM. Critical role of proline-rich tyrosine kinase 2 in reversion of the adhesion-mediated suppression of reactive oxygen species generation by human neutrophils. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2005; 174:8049-55. [PMID: 15944312 DOI: 10.4049/jimmunol.174.12.8049] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Neutrophils act as the first line of innate immune defense against invading microorganisms during infection and inflammation. The tightly regulated production of reactive oxygen species (ROS) through activation of NADPH oxidase is a major weapon used by neutrophils and other phagocytic leukocytes to combat such pathogens. Cellular adhesion signals play important physiological roles in regulating the activation of NADPH oxidase and subsequent ROS formation. We previously showed that the initial suppression of the oxidase response of chemoattractant-stimulated adherent neutrophils is mediated via inhibition of Vav1-induced activation of the NADPH oxidase regulatory GTPase Rac2 by adhesion signals. In this study we show that prior exposure of neutrophils to a number of cytokines and inflammatory mediators, including TNF-alpha, GM-CSF, and platelet-activating factor, overcomes the adhesion-mediated suppression of ROS formation. Proline-rich tyrosine kinase 2 (pyk2) activity is enhanced under these conditions, correlating with the restoration of Vav1 and Rac2 activities. Both dominant negative pyk2 and a pyk2-selective inhibitor prevented restoration of ROS production induced by TNF-alpha, GM-CSF, and platelet-activating factor, and this loss of pyk2 activity resulted in decreased Vav1 tyrosine phosphorylation and subsequent Rac2 activation. Our studies identify pyk2 as a critical regulatory component and a molecular switch to overcome the suppression of leukocyte oxidant generation by cell adhesion. This activity constitutes a mechanism by which cytokines might lead to rapid elimination of invading pathogens by adherent neutrophils under normal conditions or enhance tissue damage in pathological states.
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Affiliation(s)
- Tieming Zhao
- Department of Immunology, The Scripps Research Institute, La Jolla, CA 92037, USA.
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Haorah J, Heilman D, Knipe B, Chrastil J, Leibhart J, Ghorpade A, Miller DW, Persidsky Y. Ethanol-Induced Activation of Myosin Light Chain Kinase Leads to Dysfunction of Tight Junctions and Blood-Brain Barrier Compromise. Alcohol Clin Exp Res 2005; 29:999-1009. [PMID: 15976526 DOI: 10.1097/01.alc.0000166944.79914.0a] [Citation(s) in RCA: 135] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND Brain endothelial cells form the blood-brain barrier (BBB) that regulates solute and macromolecule flux in and out of the brain, leukocyte migration, and maintains the homeostasis of the central nervous system. BBB dysfunction is associated with disruption of tight junctions (TJ) in the brain endothelium. We propose that alcohol abuse may impair BBB permeability through TJ modification. METHODS Primary cultured bovine brain microvascular endothelial cells (BBMEC) were treated with 50 mM ethanol (EtOH), and monolayer tightness was assessed by measurement of transendothelial electrical resistance (TEER). Changes in TEER were correlated with alterations in TJ protein distribution [occludin, zonula occludens-1 (ZO-1), claudin-5] using immunofluorescence (IF). Expression of myosin light chain (MLC) kinase (MLCK), ZO-1, claudin-5, and phosphorylated MLC, occludin and claudin-5 were determined by immunoprecipitation and Western blot. EtOH-induced changes in monocyte migration across in vitro BBB constructs were also examined. RESULTS EtOH induced a decrease in TEER of BBMEC monolayers that was reversed by EtOH withdrawal. Treatment of BBMEC with EtOH or its metabolite, acetaldehyde, prior to monocyte application resulted in a 2-fold increase in monocyte migration across the BBB. IF demonstrated decrease in claudin-5 staining, occludin translocation from cell borders to cytoplasm and gap formation in EtOH-treated BBMEC monolayer. These changes paralleled significant increase in phosphorylation of MLC, occludin and claudin-5. EtOH-treated BBMEC showed reduction of total occludin and claudin-5 without changes in ZO-1 or MLC. TEER decrease, changes in occludin/claudin staining, increase in MLC, occludin and claudin-5 phosphorylation and enhanced monocyte migration across the BBB were all reversed by inhibition of MLCK. Inhibition of EtOH metabolism in BBMEC also reversed these events. CONCLUSION These results suggest that EtOH activates MLCK leading to phosphorylation of MLC, occludin and claudin-5. Cytoskeletal alterations (MLC) and TJ changes (occludin and claudin-5 phosphorylation) result in BBB impairment (decrease in TEER). TJ compromise is associated with increased monocyte migration across the BBB.
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Affiliation(s)
- James Haorah
- Center for Neurovirology and Neurodegenerative Disorders, Department of Pharmacology, University of Nebraska Medical Center, Omaha, NE 68198, USA
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Paclitaxel Impairs Endothelial Cell Adhesion But Not Cytokine-Induced Cellular Adhesion Molecule Expression. Ann Vasc Surg 2005; 19:398-406. [DOI: 10.1007/s10016-005-0013-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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29
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Bolick DT, Srinivasan S, Kim KW, Hatley ME, Clemens JJ, Whetzel A, Ferger N, Macdonald TL, Davis MD, Tsao PS, Lynch KR, Hedrick CC. Sphingosine-1-Phosphate Prevents Tumor Necrosis Factor-α–Mediated Monocyte Adhesion to Aortic Endothelium in Mice. Arterioscler Thromb Vasc Biol 2005; 25:976-81. [PMID: 15761190 DOI: 10.1161/01.atv.0000162171.30089.f6] [Citation(s) in RCA: 104] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
OBJECTIVE Endothelial activation and monocyte adhesion to endothelium are key events in inflammation. Sphingosine-1-phosphate (S1P) is a sphingolipid that binds to G protein-coupled receptors on endothelial cells (ECs). We examined the role of S1P in modulating endothelial activation and monocyte-EC interactions in vivo. METHODS AND RESULTS We injected C57BL/6J mice intravenously with tumor necrosis factor (TNF)-alpha in the presence and absence of the S1P1 receptor agonist SEW2871 and examined monocyte adhesion. Aortas from TNF-alpha-injected mice had a 4-fold increase in the number of monocytes bound, whereas aortas from TNF-alpha plus SEW2871-treated mice had few monocytes bound (P<0.0001). Using siRNA, we found that inhibiting the S1P1 receptor in vascular ECs blocked the ability of S1P to prevent monocyte-EC interactions in response to TNF-alpha. We examined signaling pathways downstream of S1P1 and found that 100 nM S1P increased phosphorylation of Akt and decreased activation of c-jun. CONCLUSIONS Thus, we provide the first evidence that S1P signaling through the endothelial S1P1 receptor protects the vasculature against TNF-alpha-mediated monocyte-EC interactions in vivo.
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Affiliation(s)
- David T Bolick
- Division of Endocrinology & Metabolism and Cardiovascular Research Center, University of Virginia, Charlottesville, Va 22908, USA
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30
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Affiliation(s)
- K Alexander Papp
- Probity Medical Research, and University of Western Ontario, London, Ontario, Canada.
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Woods A, Wang G, Beier F. RhoA/ROCK signaling regulates Sox9 expression and actin organization during chondrogenesis. J Biol Chem 2005; 280:11626-34. [PMID: 15665004 DOI: 10.1074/jbc.m409158200] [Citation(s) in RCA: 225] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Endochondral ossification is initiated by the differentiation of mesenchymal precursor cells to chondrocytes (chondrogenesis). This process is characterized by a strong interdependence of cell shape, cytoskeletal organization, and the onset of chondrogenic gene expression, but the molecular mechanisms mediating these interactions are not known. Here we investigated the role of the RhoA/ROCK pathway, a well characterized regulator of cytoskeletal organization, in chondrogenesis. We show that pharmacological inhibition of ROCK signaling by Y27632 resulted in increased glycosaminoglycan synthesis and elevated expression of the chondrogenic transcription factor Sox9, whereas overexpression of RhoA in the chondrogenic cell line ATDC5 had the opposite effects. Suppression of Sox9 expression by ROCK signaling was achieved through repression of Sox9 promoter activity. These molecular changes were accompanied by reorganization of the actin cytoskeleton, where RhoA/ROCK signaling suppressed cortical actin organization, a hallmark of differentiated chondrocytes. This led us to analyze the regulation of Sox9 expression by drugs affecting cytoskeletal dynamics. Both inhibition of actin polymerization by cytochalasin D and stabilization of existing actin filaments by jasplakinolide resulted in increased Sox9 mRNA levels, whereas inhibition of microtubule polymerization by colchicine completely blocked Sox9 expression. In conclusion, our data suggest that RhoA/ROCK signaling suppresses chondrogenesis through the control of Sox9 expression and actin organization.
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Affiliation(s)
- Anita Woods
- Canadian Institutes of Health Research Group in Skeletal Development and Remodeling, Department of Physiology and Pharmacology, University of Western Ontario, London, Ontario N6A 5C1, Canada
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