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Stevenson TK, Moore SJ, Murphy GG, Lawrence DA. Tissue Plasminogen Activator in Central Nervous System Physiology and Pathology: From Synaptic Plasticity to Alzheimer's Disease. Semin Thromb Hemost 2021; 48:288-300. [DOI: 10.1055/s-0041-1740265] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
AbstractTissue plasminogen activator's (tPA) fibrinolytic function in the vasculature is well-established. This specific role for tPA in the vasculature, however, contrasts with its pleiotropic activities in the central nervous system. Numerous physiological and pathological functions have been attributed to tPA in the central nervous system, including neurite outgrowth and regeneration; synaptic and spine plasticity; neurovascular coupling; neurodegeneration; microglial activation; and blood–brain barrier permeability. In addition, multiple substrates, both plasminogen-dependent and -independent, have been proposed to be responsible for tPA's action(s) in the central nervous system. This review aims to dissect a subset of these different functions and the different molecular mechanisms attributed to tPA in the context of learning and memory. We start from the original research that identified tPA as an immediate-early gene with a putative role in synaptic plasticity to what is currently known about tPA's role in a learning and memory disorder, Alzheimer's disease. We specifically focus on studies demonstrating tPA's involvement in the clearance of amyloid-β and neurovascular coupling. In addition, given that tPA has been shown to regulate blood–brain barrier permeability, which is perturbed in Alzheimer's disease, this review also discusses tPA-mediated vascular dysfunction and possible alternative mechanisms of action for tPA in Alzheimer's disease pathology.
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Affiliation(s)
- Tamara K. Stevenson
- Michigan Neuroscience Institute, University of Michigan Medical School, Ann Arbor, Michigan
- Department of Molecular and Integrative Physiology, Division of Cardiovascular Medicine, University of Michigan Medical School, Ann Arbor, Michigan
| | - Shannon J. Moore
- Michigan Neuroscience Institute, University of Michigan Medical School, Ann Arbor, Michigan
- Department of Molecular and Integrative Physiology, Division of Cardiovascular Medicine, University of Michigan Medical School, Ann Arbor, Michigan
| | - Geoffrey G. Murphy
- Michigan Neuroscience Institute, University of Michigan Medical School, Ann Arbor, Michigan
- Department of Molecular and Integrative Physiology, Division of Cardiovascular Medicine, University of Michigan Medical School, Ann Arbor, Michigan
| | - Daniel A. Lawrence
- Department of Molecular and Integrative Physiology, Division of Cardiovascular Medicine, University of Michigan Medical School, Ann Arbor, Michigan
- Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, Michigan
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Liao Y, Bae HJ, Zhang J, Kwon Y, Koo B, Jung IH, Kim HM, Park JH, Lew JH, Ryu JH. The Ameliorating Effects of Bee Pollen on Scopolamine-Induced Cognitive Impairment in Mice. Biol Pharm Bull 2019; 42:379-388. [DOI: 10.1248/bpb.b18-00552] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Affiliation(s)
- Yulan Liao
- Department of Life and Nanopharmaceutical Science, Kyung Hee University
| | - Ho Jung Bae
- Department of Life and Nanopharmaceutical Science, Kyung Hee University
| | - Jiabao Zhang
- Department of Life and Nanopharmaceutical Science, Kyung Hee University
| | - Yubeen Kwon
- Department of Life and Nanopharmaceutical Science, Kyung Hee University
| | - Bokyung Koo
- Department of Life and Nanopharmaceutical Science, Kyung Hee University
| | - In Ho Jung
- Department of Life and Nanopharmaceutical Science, Kyung Hee University
| | | | - Jong Hun Park
- Graduate School of East-West Medical Science, Kyung Hee University
| | - Jae Hwan Lew
- Graduate School of East-West Medical Science, Kyung Hee University
| | - Jong Hoon Ryu
- Department of Life and Nanopharmaceutical Science, Kyung Hee University
- Department of Oriental Pharmaceutical Science, Kyung Hee University
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Kidoguchi M, Noguchi E, Nakamura T, Ninomiya T, Morii W, Yoshida K, Morikawa T, Kato Y, Imoto Y, Sakashita M, Takabayashi T, Fujieda S. DNA Methylation of Proximal PLAT Promoter in Chronic Rhinosinusitis With Nasal Polyps. Am J Rhinol Allergy 2018; 32:374-379. [DOI: 10.1177/1945892418782236] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Background Nasal polyps (NP) are characterized by pseudocysts derived from stromal tissue edema and cause persistent infections in patients with chronic rhinosinusitis (CRS). A low level of tissue-type plasminogen activator (gene name PLAT) is considered a cause of stromal tissue edema because of insufficient plasmin activation in NP; however, the mechanism regulating PLAT gene expression levels is still unclear. The epigenetic mechanism regulating the PLAT gene expression has been studied in other tissues. Objective We aimed to investigate the methylation levels in the proximal PLAT promoter and their effects on gene expression in NP tissue. Methods We investigated the methylation levels at 3 CpG sites in the proximal PLAT promoter regions (−618, −121, and −105 with respect to the transcription initiation site) by bisulfite pyrosequencing and their effects on the gene expression by quantitative real-time polymerase chain reaction (qPCR) in 20 paired samples of NP and inferior turbinate tissue (IT) from patients with CRS. Results The DNA methylation levels at all CpG sites were higher ( P < .01), and the PLAT expression was lower ( P < .001) in NP compared with IT. The methylation changes at the −618 site showed a negative correlation with the gene expression changes between NP and IT ( r = −.65, P < .01). Conclusions Hypermethylation of PLAT promoter may downregulate the gene expression in NP, leading to excessive fibrin deposition by aberrant coagulation cascade. DNA methylation of proximal PLAT promoter may contribute to NP growth and have a potential as a new therapeutic target.
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Affiliation(s)
- Masanori Kidoguchi
- Department of Medical Genetics, Faculty of Medicine, University of Tsukuba, Tsukuba, Japan
- Division of Otorhinolaryngology and Head and Neck Surgery, Department of Sensory and Locomotor Medicine, Faculty of Medical Science, University of Fukui, Fukui, Japan
| | - Emiko Noguchi
- Department of Medical Genetics, Faculty of Medicine, University of Tsukuba, Tsukuba, Japan
| | - Takako Nakamura
- Department of Medical Genetics, Faculty of Medicine, University of Tsukuba, Tsukuba, Japan
| | - Takahiro Ninomiya
- Division of Otorhinolaryngology and Head and Neck Surgery, Department of Sensory and Locomotor Medicine, Faculty of Medical Science, University of Fukui, Fukui, Japan
| | - Wataru Morii
- Department of Medical Genetics, Faculty of Medicine, University of Tsukuba, Tsukuba, Japan
| | - Kanako Yoshida
- Division of Otorhinolaryngology and Head and Neck Surgery, Department of Sensory and Locomotor Medicine, Faculty of Medical Science, University of Fukui, Fukui, Japan
| | - Taiyo Morikawa
- Division of Otorhinolaryngology and Head and Neck Surgery, Department of Sensory and Locomotor Medicine, Faculty of Medical Science, University of Fukui, Fukui, Japan
| | - Yukinori Kato
- Division of Otorhinolaryngology and Head and Neck Surgery, Department of Sensory and Locomotor Medicine, Faculty of Medical Science, University of Fukui, Fukui, Japan
| | - Yoshimasa Imoto
- Division of Otorhinolaryngology and Head and Neck Surgery, Department of Sensory and Locomotor Medicine, Faculty of Medical Science, University of Fukui, Fukui, Japan
| | - Masafumi Sakashita
- Division of Otorhinolaryngology and Head and Neck Surgery, Department of Sensory and Locomotor Medicine, Faculty of Medical Science, University of Fukui, Fukui, Japan
| | - Tetsuji Takabayashi
- Division of Otorhinolaryngology and Head and Neck Surgery, Department of Sensory and Locomotor Medicine, Faculty of Medical Science, University of Fukui, Fukui, Japan
| | - Shigeharu Fujieda
- Division of Otorhinolaryngology and Head and Neck Surgery, Department of Sensory and Locomotor Medicine, Faculty of Medical Science, University of Fukui, Fukui, Japan
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Tjärnlund-Wolf A, Hultman K, Curtis M, Faull R, Medcalf R, Jern C. Allelic imbalance of tissue-type plasminogen activator (t-PA) gene expression in human brain tissue. Thromb Haemost 2017; 105:945-53. [DOI: 10.1160/th10-10-0682] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2010] [Accepted: 02/10/2011] [Indexed: 11/05/2022]
Abstract
SummaryWe have identified a single-nucleotide polymorphism (SNP) in the t-PA enhancer (-7351C>T), which is associated with endothelial t-PA release in vivo. In vitro studies demonstrated that this SNP is functional at the level of transcription. In the brain, t-PA has been implicated in both physiologic and pathophysiologic processes. The aim of the present study was to examine the effect of the t-PA –7351C>T SNP on t-PA gene expression in human brain tissue. Allelic mRNA expression was measured in heterozygous post-mortem brain tissues using quantitative TaqMan genotyping assay. Protein-DNA interactions were assessed using electrophoretic mobility shift assay (EMSA) and chromatin immunoprecipitation (ChIP). Significantly higher levels of t-PA mRNA were generated from chromosomes that harboured the wild-type –7351C allele, as compared to those generated from the mutant T allele (for the hippocampus, C to T allelic ratio of ~1.3, p=0.010, n=12; and for the cortex, C to T allelic ratio of ~1.2, p=0.017, n=12). EMSA showed reduced neuronal and astrocytic nuclear protein binding affinity to the T allele, and identified Sp1 and Sp3 as the major transcription factors that bound to the –7351 site. ChIP analyses confirmed that Sp1 recognises this site in intact cells. In conclusion, the t-PA –7351C>T SNP affects t-PA gene expression in human brain tissue. This finding might have clinical implications for neurological conditions associated with enhanced t-PA levels, such as in the acute phase of cerebral ischaemia, and also for stroke recovery.
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Effect of Regulatory Element DNA Methylation on Tissue-Type Plasminogen Activator Gene Expression. PLoS One 2016; 11:e0167588. [PMID: 27973546 PMCID: PMC5156355 DOI: 10.1371/journal.pone.0167588] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2016] [Accepted: 11/16/2016] [Indexed: 12/31/2022] Open
Abstract
Expression of the tissue-type plasminogen activator gene (t-PA; gene name PLAT) is regulated, in part, by epigenetic mechanisms. We investigated the relationship between PLAT methylation and PLAT expression in five primary human cell types and six transformed cell lines. CpG methylation was analyzed in the proximal PLAT gene promoter and near the multihormone responsive enhancer (MHRE) -7.3 kilobase pairs upstream of the PLAT transcriptional start site (TSS, -7.3 kb). In Bowes melanoma cells, the PLAT promoter and the MHRE were fully unmethylated and t-PA secretion was extremely high. In other cell types the region from -647 to -366 was fully methylated, whereas an unmethylated stretch of DNA from -121 to +94 was required but not sufficient for detectable t-PA mRNA and t-PA secretion. DNA methylation near the MHRE was not correlated with t-PA secretion. Specific methylation of the PLAT promoter region -151 to +151, inserted into a firefly luciferase reporter gene, abolished reporter gene activity. The region -121 to + 94 contains two well-described regulatory elements, a PMA-responsive element (CRE) near -106 and a GC-rich region containing an Sp1 binding site near +59. Methylation of double-stranded DNA oligonucleotides containing the CRE or the GC-rich region had little or no effect on transcription factor binding. Methylated CpGs may attract co-repressor complexes that contain histone deacetylases (HDAC). However, reporter gene activity of methylated plasmids was not restored by the HDAC inhibitor trichostatin. In conclusion, efficient PLAT gene expression requires a short stretch of unmethylated CpG sites in the proximal promoter.
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Thrombus Degradation by Fibrinolytic Enzyme of Stenotrophomonas sp. Originated from Indonesian Soybean-Based Fermented Food on Wistar Rats. Adv Pharmacol Sci 2016; 2016:4206908. [PMID: 27635131 PMCID: PMC5011239 DOI: 10.1155/2016/4206908] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2016] [Revised: 07/11/2016] [Accepted: 07/26/2016] [Indexed: 11/30/2022] Open
Abstract
Objective. To evaluate thrombus degrading effect of a fibrinolytic enzyme from food origin Stenotrophomonas sp. of Indonesia. Methods. Prior to animal study, the enzyme safety was tested using cell culture. The effect on expression of tissue plasminogen activator was also analysed in the cell culture. For in vivo studies, 25 Wistar rats were used: normal control, negative control, treatment groups with crude and semipurified enzyme given orally at 25 mg/kg, and positive control group which received Lumbrokinase at 25 mg/kg. Blood clot in the tail was induced by kappa carrageenan injection at 1 mg/kg BW. Results. Experiment with cell culture confirmed the enzyme safety at the concentration used and increased expression of tPA. Decreasing of thrombus was observed in the positive group down to 70.35 ± 23.11% of the negative control animals (100%). The thrombus observed in the crude enzyme treatment was down to 56.99 ± 15.95% and 71.5 ± 15.7% for semipurified enzyme. Scanning electron microscopy showed clearly that bood clots were found in the animals injected with kappa carrageenan; however, in the treatment and positive groups, the clot was much reduced. Conclusions. Oral treatment of enzyme from Stenotrophomonas sp. of Indonesian fermented food was capable of degrading thrombus induced in Wistar rats.
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Dependence of Proximal GC Boxes and Binding Transcription Factors in the Regulation of Basal and Valproic Acid-Induced Expression of t-PA. Int J Vasc Med 2016; 2016:7928681. [PMID: 26966581 PMCID: PMC4761389 DOI: 10.1155/2016/7928681] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2015] [Revised: 12/18/2015] [Accepted: 12/27/2015] [Indexed: 01/09/2023] Open
Abstract
Objective. Endothelial tissue-type plasminogen activator (t-PA) release is a pivotal response to protect the circulation from occluding thrombosis. We have shown that the t-PA gene is epigenetically regulated and greatly induced by the histone deacetylase (HDAC) inhibitor valproic acid (VPA). We now investigated involvement of known t-PA promoter regulatory elements and evaluated dependence of potential interacting transcription factors/cofactors. Methods. A reporter vector with an insert, separately mutated at either the t-PA promoter CRE or GC box II or GC box III elements, was transfected into HT-1080 and HUVECs and challenged with VPA. HUVECs were targeted with siRNA against histone acetyl transferases (HAT) and selected transcription factors from the Sp/KLF family. Results. An intact VPA-response was observed with CRE mutated constructs, whereas mutation of GC boxes II and III reduced the magnitude of the induction by 54 and 79% in HT-1080 and 49 and 50% in HUVECs, respectively. An attenuated induction of t-PA mRNA was observed after Sp2, Sp4, and KLF5 depletion. KLF2 and p300 (HAT) were identified as positive regulators of basal t-PA expression and Sp4 and KLF9 as repressors. Conclusion. VPA-induced t-PA expression is dependent on the proximal GC boxes in the t-PA promoter and may involve interactions with Sp2, Sp4, and KLF5.
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Tjärnlund-Wolf A, Hultman K, Blomstrand F, Nilsson M, Medcalf RL, Jern C. Species-Specific Regulation of t-PA and PAI-1 Gene Expression in Human and Rat Astrocytes. GENE REGULATION AND SYSTEMS BIOLOGY 2014; 8:113-8. [PMID: 24855337 PMCID: PMC4024051 DOI: 10.4137/grsb.s13387] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/09/2013] [Revised: 02/17/2014] [Accepted: 02/25/2014] [Indexed: 11/06/2022]
Abstract
In recent years, the role and physiological regulation of the serine protease tissue-type plasminogen activator (t-PA) and its inhibitors, including plasminogen activator inhibitor type-1 (PAI-1), in the brain have received much attention. However, as studies focusing these issues are difficult to perform in humans, a great majority of the studies conducted to date have utilized rodent in vivo and/or in vitro models. In view of the species-specific structural differences present in both the t-PA and the PAI-1 promoters, we have compared the response of these genes in astrocytes of rat and human origin. We reveal marked quantitative and qualitative species-specific differences in gene induction following treatment with various physiological and pathological stimuli. Thus, our findings are of importance for the interpretation of previous and future results related to t-PA and PAI-1 expression.
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Affiliation(s)
- Anna Tjärnlund-Wolf
- Institute of Neuroscience and Physiology, Section for Clinical Neuroscience and Rehabilitation, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Karin Hultman
- Institute of Neuroscience and Physiology, Section for Clinical Neuroscience and Rehabilitation, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Fredrik Blomstrand
- Institute of Neuroscience and Physiology, Section for Clinical Neuroscience and Rehabilitation, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Michael Nilsson
- Institute of Neuroscience and Physiology, Section for Clinical Neuroscience and Rehabilitation, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden. ; Hunter Medical Research Institute, University of Newcastle, Newcastle, Australia
| | - Robert L Medcalf
- Australian Centre for Blood Diseases, Department of Clinical Haematology, Alfred Medical Research and Education Precinct, Monash University, Victoria, Australia
| | - Christina Jern
- Institute of Biomedicine, Department of Medical and Clinical Genetics, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
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Kruithof EKO, Dunoyer-Geindre S. Human tissue-type plasminogen activator. Thromb Haemost 2014; 112:243-54. [PMID: 24718307 DOI: 10.1160/th13-06-0517] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2013] [Accepted: 03/07/2014] [Indexed: 11/05/2022]
Abstract
Tissue-type plasminogen activator (t-PA ) plays an important role in the removal of intravascular fibrin deposits and has several physiological roles and pathological activities in the brain. Its production by many other cell types suggests that t-PA has additional functions outside the vascular and central nervous system. Activity of t-PA is regulated at the level of its gene transcription, its mRNA stability and translation, its storage and regulated release, its interaction with cofactors that enhance its activity, its inhibition by inhibitors such as plasminogen activator inhibitor type 1 or neuroserpin, and its removal by clearance receptors. Gene transcription of t-PA is modulated by a large number of hormones, growth factors, cytokines or drugs and t-PA gene responses may be tissue-specific. The aim of this review is to summarise current knowledge on t-PA function and regulation of its pericellular activity, with an emphasis on regulation of its gene expression.
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Affiliation(s)
- E K O Kruithof
- Egbert K.O. Kruithof, Division of Angiology and Hemostasis, Department of internal medicine, University Hospital of Geneva and Faculty of Medicine of the University of Geneva, University Medical Center CMU 9094, 1 Rue Michel Servet, CH1211 Geneva 4, Switzerland, Tel.: +41 22 3795493 or +41 22 3795567, E-mail:
| | - S Dunoyer-Geindre
- Sylvie Dunoyer-Geindre, Division of Angiology and Hemostasis, Department of internal medicine, University Hospital of Geneva and Faculty of Medicine of the University of Geneva, University Medical Center CMU 9094, 1 Rue Michel Servet, CH1211 Geneva 4, Switzerland, Tel.: +41 22 3795493 or +41 22 3795567, E-mail:
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Ungaro P, Mirra P, Oriente F, Nigro C, Ciccarelli M, Vastolo V, Longo M, Perruolo G, Spinelli R, Formisano P, Miele C, Beguinot F. Peroxisome proliferator-activated receptor-γ activation enhances insulin-stimulated glucose disposal by reducing ped/pea-15 gene expression in skeletal muscle cells: evidence for involvement of activator protein-1. J Biol Chem 2012; 287:42951-61. [PMID: 23105093 DOI: 10.1074/jbc.m112.406637] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
The gene network responsible for inflammation-induced insulin resistance remains enigmatic. In this study, we show that, in L6 cells, rosiglitazone- as well as pioglitazone-dependent activation of peroxisome proliferator-activated receptor-γ (PPARγ) represses transcription of the ped/pea-15 gene, whose increased activity impairs glucose tolerance in mice and humans. Rosiglitazone enhanced insulin-induced glucose uptake in L6 cells expressing the endogenous ped/pea-15 gene but not in cells expressing ped/pea-15 under the control of an exogenous promoter. The ability of PPARγ to affect ped/pea-15 expression was also lost in cells and in C57BL/6J transgenic mice expressing ped/pea-15 under the control of an exogenous promoter, suggesting that ped/pea-15 repression may contribute to rosiglitazone action on glucose disposal. Indeed, high fat diet mice showed insulin resistance and increased ped/pea-15 levels, although these effects were reduced by rosiglitazone treatment. Both supershift and ChIP assays revealed the presence of the AP-1 component c-JUN at the PED/PEA-15 promoter upon 12-O-tetradecanoylphorbol-13-acetate stimulation of the cells. In these experiments, rosiglitazone treatment reduced c-JUN presence at the PED/PEA-15 promoter. This effect was not associated with a decrease in c-JUN expression. In addition, c-jun silencing in L6 cells lowered ped/pea-15 expression and caused nonresponsiveness to rosiglitazone, although c-jun overexpression enhanced the binding to the ped/pea-15 promoter and blocked the rosiglitazone effect. These results indicate that PPARγ regulates ped/pea-15 transcription by inhibiting c-JUN binding at the ped/pea-15 promoter. Thus, ped/pea-15 is downstream of a major PPARγ-regulated inflammatory network. Repression of ped/pea-15 transcription might contribute to the PPARγ regulation of muscle sensitivity to insulin.
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Affiliation(s)
- Paola Ungaro
- Dipartimento di Biologia e Patologia Cellulare e Molecolare, Università di Napoli "Federico II", Consiglio Nazionale delle Ricerche, 80131 Naples, Italy.
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Abstract
Nature has provided a vast array of bioactive compounds that have been exploited for either diagnostic or therapeutic use. The field of thrombosis and haemostasis in particular has enjoyed much benefit from compounds derived from nature, notably from snakes and blood-feeding animals. Indeed, the likelihood that blood-feeding animals would harbour reagents with relevant pharmacology and with potential pharmaceutical benefit in haemostasis was not too far-fetched. Blood-feeding animals including leeches and ticks have evolved a means to keep blood from clotting or to at least maintain the liquid state, and some of these have been the subject of clinical development. A more recent example of this has been the saliva of the common vampire bat Desmodus rotundus, which has proven to harbour a veritable treasure trove of novel regulatory molecules. Among the bioactive compounds present is a fibrinolytic compound that was shown over 40 years ago to be a potent plasminogen activator. Studies of this vampire bat-derived plasminogen activator, more recently referred to as desmoteplase, revealed that this protease shared a number of structural and functional similarities to the human fibrinolytic protease, tissue-type plasminogen activator (t-PA) yet harboured critically important differences that have rendered this molecule attractive for clinical development for patients with ischaemic stroke.
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Affiliation(s)
- Robert L Medcalf
- Australian Centre for Blood Diseases, Monash University, 89 Commercial Road, Melbourne, Victoria, Australia.
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Larsson P, Ulfhammer E, Magnusson M, Bergh N, Lunke S, El-Osta A, Medcalf RL, Svensson PA, Karlsson L, Jern S. Role of histone acetylation in the stimulatory effect of valproic acid on vascular endothelial tissue-type plasminogen activator expression. PLoS One 2012; 7:e31573. [PMID: 22363677 PMCID: PMC3282745 DOI: 10.1371/journal.pone.0031573] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2011] [Accepted: 01/13/2012] [Indexed: 11/19/2022] Open
Abstract
Aims Stimulated release of tissue-type plasminogen activator (t-PA) is pivotal for an intravascular fibrinolytic response and protects the circulation from occluding thrombosis. Hence, an impaired t-PA production is associated with increased risk for atherothrombotic events. A pharmacological means to stimulate the production of this enzyme may thus be desirable. We investigated if the anti-epileptic drug valproic acid (VPA) is capable of enhancing t-PA expression in vitro in vascular endothelial cells, and further examined if its histone deacetylase (HDAC)-inhibitory activity is of importance for regulating t-PA expression. Methods and Results Human endothelial cells were exposed to valproic acid and t-PA mRNA and protein levels were quantified. Potential changes in histone acetylation status globally and at the t-PA promoter were examined by western blot and chromatin immunoprecipitation. Valproic acid dose-dependently stimulated t-PA mRNA and protein expression in endothelial cells reaching a 2–4-fold increase at clinically relevant concentrations and 10-fold increase at maximal concentrations. Transcription profiling analysis revealed that t-PA is selectively targeted by this agent. Augmented histone acetylation was detected at the t-PA transcription start site, and an attenuated VPA-response was observed with siRNA knock of HDAC3, HDAC5 and HDAC7. Conclusions Valproic acid induces t-PA expression in cultured endothelial cells, and this is associated with increased histone acetylation at the t-PA promoter. Given the apparent potency of valproic acid in stimulating t-PA expression in vitro this substance may be a candidate for pharmacological modulation of endogenous fibrinolysis in man.
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Affiliation(s)
- Pia Larsson
- The Wallenberg Laboratory for Cardiovascular Research, Institute of Medicine, The Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Erik Ulfhammer
- The Wallenberg Laboratory for Cardiovascular Research, Institute of Medicine, The Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Mia Magnusson
- The Wallenberg Laboratory for Cardiovascular Research, Institute of Medicine, The Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Niklas Bergh
- The Wallenberg Laboratory for Cardiovascular Research, Institute of Medicine, The Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Sebastian Lunke
- Epigenetics in Human Health and Disease Laboratory, Baker IDI Heart and Diabetes Institute, The Alfred Medical Research and Education Precinct, Melbourne, Victoria, Australia
| | - Assam El-Osta
- Epigenetics in Human Health and Disease Laboratory, Baker IDI Heart and Diabetes Institute, The Alfred Medical Research and Education Precinct, Melbourne, Victoria, Australia
| | - Robert L. Medcalf
- Australian Centre for Blood Diseases, The Alfred Medical Research and Education Point, Monash University, Melbourne, Victoria, Australia
| | - Per-Arne Svensson
- Sahlgrenska Center for Cardiovascular and Metabolic Research, Department of Molecular and Clinical Medicine, Institute of Medicine, The Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Lena Karlsson
- The Wallenberg Laboratory for Cardiovascular Research, Institute of Medicine, The Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Sverker Jern
- The Wallenberg Laboratory for Cardiovascular Research, Institute of Medicine, The Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
- * E-mail:
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OHSUGI TADANORI, SUMI HIROYUKI. THE EFFECTS OF DIPICOLINIC ACID ON THE THROMBOLYTIC ACTIVITY OF HUMAN CELLS. J Food Biochem 2011. [DOI: 10.1111/j.1745-4514.2010.00388.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Dunoyer-Geindre S, Kruithof EKO. Epigenetic control of tissue-type plasminogen activator synthesis in human endothelial cells. Cardiovasc Res 2011; 90:457-63. [PMID: 21282301 DOI: 10.1093/cvr/cvr028] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
AIMS Tissue-type plasminogen activator (t-PA) is produced by endothelial cells (EC) and is responsible for the removal of intravascular fibrin deposits. We investigated whether expression of t-PA by EC is under epigenetic control. METHODS AND RESULTS Methylation analysis of the proximal t-PA promoter revealed a stretch of unmethylated CpG dinucleotides from position -121 to +59, while upstream CpG dinucleotides were all methylated. In contrast, in human primary hepatocytes, which express t-PA at much lower levels than EC, the proximal promoter was partially methylated. Treatment of EC with the non-specific histone deacetylase (HDAC) inhibitors butyrate and trichostatin and with MS275, a specific inhibitor of class I HDAC, resulted in a time- and dose-dependent increase in t-PA expression. Garcinol and anacardic acid, inhibitors of the histone acetyl transferases CBP/p300 and PCAF, reduced basal and HDAC inhibitor-induced t-PA expression, whereas curcumin, an inhibitor of CBP/p300 only, had no effect. We performed chromosome immunoprecipitation analysis of the t-PA promoter using antibodies specific for acetylated histone H3 or H4 and observed an increase in H3 acetylation of 10 ± 3 and 44 ± 14-fold in EC treated with trichostatin or MS275, respectively, and in H4 acetylation of 7.7 ± 1.4 and 16 ± 3-fold, respectively. CONCLUSION The proximal t-PA promoter is unmethylated in human EC and partially methylated in human primary hepatocytes. Expression of t-PA by EC is repressed by HDACs in a mechanism that involves de-acetylation of histone H3 and H4.
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Affiliation(s)
- Sylvie Dunoyer-Geindre
- Division of Angiology and Hemostasis, University Hospital of Geneva, University Medical Center, Room 9094, Rue Michel Servet 1, CH-1211, Geneva, Switzerland
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15
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Red wine metabolites modulate NF-κB, activator protein-1 and cAMP response element-binding proteins in human endothelial cells. Br J Nutr 2009; 103:807-14. [DOI: 10.1017/s0007114509992479] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
We have studied the effect of human serum, collected after red wine consumption (RWS), on TNF-α-dependent activation of transcription factors (NF-κB, activator protein-1 (AP-1) and cAMP response element-binding proteins) and on the expression of selected genes involved in cell adhesion or fibrinolysis processes in human primary endothelial cells (human umbilical vein endothelial cells (HUVEC)). Our data indicate that RWS containing RW metabolites, isolated after 40 min from an acute consume of wine (5 ml/kg body weight), induces nuclear translocation of NF-κB and AP-1 in the absence of any further stimulus. On the other hand, TNF-α treatment in the presence of RWS is associated with a delay in transcription factor activation and to a negative modulation on the expression of specific genes. Moreover, RWS stimulates c-jun binding to the tissue-type plasminogen activator cAMP responsive element consensus site modulating the expression of the specific gene downstream. These results confirm that RW metabolites affect the activity of different transcription factors playing an important preconditioning role in the modulation of the inflammatory pathway in endothelial cells. This is the first report on the effects of a complex food matrix, on the molecular mechanisms associated with inflammatory response in HUVEC cultured in condition that reproduces the physiological environment occurring in vivo.
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16
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Hultman K, Tjärnlund-Wolf A, Fish RJ, Wilhelmsson U, Rydenhag B, Pekny M, Kruithof EKO, Jern C. Retinoids and activation of PKC induce tissue-type plasminogen activator expression and storage in human astrocytes. J Thromb Haemost 2008; 6:1796-803. [PMID: 18647223 DOI: 10.1111/j.1538-7836.2008.03084.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
BACKGROUND Emerging data demonstrate important roles for tissue-type plasminogen activator (t-PA) in the central nervous system (CNS). In contrast to endothelial cells, little is known about the regulation of t-PA gene expression and secretion in astrocytes. OBJECTIVES The aims of the present study were to investigate whether t-PA gene expression is regulated by retinoids and the protein kinase C (PKC) activator phorbol 12-myristate 13-acetate (PMA) in human astrocytes, and to study whether t-PA is stored and subject to regulated release from these cells, as with endothelial cells. METHODS Native human astrocytes were treated with RA and/or PMA. mRNA was quantified by real-time RT-PCR and protein secretion determined by ELISA. Intracellular t-PA immunoreactivity in astrocytes was examined by immunocyto- and histochemistry. RESULTS RA and/or PMA induced a time-dependent increase in t-PA mRNA and protein levels in astrocytes, reaching 10-fold after combined treatment. This was associated with increased amounts of t-PA storage in intracellular granular structures. Both forskolin and histamine induced regulated release of t-PA. The presence of t-PA in reactive astrocytes was confirmed in human brain tissue. CONCLUSIONS These data show that RA and PKC activation induce a strong up-regulation of t-PA expression in astrocytes, and increased intracellular storage pools. Moreover, a regulated release of t-PA can be induced from these cells. This raises the possibility that astrocytes contribute to the regulation of extracellular t-PA levels in the CNS.
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Affiliation(s)
- K Hultman
- Institute of Neuroscience and Physiology, Department of Clinical Neuroscience and Rehabilitation, the Sahlgrenska Academy at University of Gothenburg, Department of Clinical Genetics, Sahlgrenska University Hospital, Gothenburg, Sweden
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17
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Holmberg M, Leonardsson G, Tor NY. The Species-Specific Differences in the cAMP Regulation of the Tissue-Type Plasminogen Activator Gene between Rat, Mouse and Human is Caused by a One-Nucleotide Substitution in the cAMP-Responsive Element of the Promoters. ACTA ACUST UNITED AC 2008. [DOI: 10.1111/j.1432-1033.1995.0466e.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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18
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Regulation of cAMP by the p75 neurotrophin receptor: insight into drug design of selective phosphodiesterase inhibitors. Biochem Soc Trans 2008; 35:1273-7. [PMID: 17956328 DOI: 10.1042/bst0351273] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Subcellular compartmentalization of PDEs (phosphodiesterases) is a major mechanism for the regulation of cAMP signalling. The identification of the proteins that recruit specific PDE isoforms to subcellular compartments can shed light on the regulation of spatial and temporal cAMP gradients in living cells and provide novel therapeutic targets for inhibiting functions of PDEs. We showed recently that p75(NTR) (p75 neurotrophin receptor) interacts directly with a single PDE isoform, namely PDE4A4/5, via binding to its unique C-terminal region, and targets cAMP degradation to the membrane. The purpose of this review is to present the biological significance of PDE4A compartmentalization by p75(NTR) and discuss the potential of inhibiting the interaction between p75(NTR) and PDE4A for the development of an isoform-specific inhihibitor for PDEs.
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19
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Sachs BD, Baillie GS, McCall JR, Passino MA, Schachtrup C, Wallace DA, Dunlop AJ, MacKenzie KF, Klussmann E, Lynch MJ, Sikorski SL, Nuriel T, Tsigelny I, Zhang J, Houslay MD, Chao MV, Akassoglou K. p75 neurotrophin receptor regulates tissue fibrosis through inhibition of plasminogen activation via a PDE4/cAMP/PKA pathway. ACTA ACUST UNITED AC 2007; 177:1119-32. [PMID: 17576803 PMCID: PMC2064370 DOI: 10.1083/jcb.200701040] [Citation(s) in RCA: 101] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Clearance of fibrin through proteolytic degradation is a critical step of matrix remodeling that contributes to tissue repair in a variety of pathological conditions, such as stroke, atherosclerosis, and pulmonary disease. However, the molecular mechanisms that regulate fibrin deposition are not known. Here, we report that the p75 neurotrophin receptor (p75NTR), a TNF receptor superfamily member up-regulated after tissue injury, blocks fibrinolysis by down-regulating the serine protease, tissue plasminogen activator (tPA), and up-regulating plasminogen activator inhibitor-1 (PAI-1). We have discovered a new mechanism in which phosphodiesterase PDE4A4/5 interacts with p75NTR to enhance cAMP degradation. The p75NTR-dependent down-regulation of cAMP results in a decrease in extracellular proteolytic activity. This mechanism is supported in vivo in p75NTR-deficient mice, which show increased proteolysis after sciatic nerve injury and lung fibrosis. Our results reveal a novel pathogenic mechanism by which p75NTR regulates degradation of cAMP and perpetuates scar formation after injury.
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Affiliation(s)
- Benjamin D Sachs
- Department of Pharmacology, University of California, San Diego, La Jolla, CA 92093, USA
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20
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Abstract
The maintenance of a given physiological process demands a coordinated and spatially regulated pattern of gene regulation. This applies to genes encoding components of enzyme cascades, including those of the plasminogen activating system. This family of proteases is vital to fibrinolysis and dysregulation of the expression pattern of one or more of these proteins in response to inflammatory events can impact on hemostasis. Gene regulation occurs on many levels, and it is apparent that the genes encoding the plasminogen activator (fibrinolytic) proteins are subject to both direct transcriptional control and significant post-transcriptional mechanisms. It is now clear that perturbation of these genes at either of these levels can dramatically alter expression levels and have a direct impact on the host's response to a variety of physiological and pharmacological challenges. Inflammatory processes are well known to impact on the fibrinolytic system and to promote thrombosis, cancer and diabetes. This review discusses how inflammatory and other signals affect the transcriptional and post-transcriptional expression patterns of this system, and how this modulates fibrinolysis in vivo.
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Affiliation(s)
- R L Medcalf
- Australian Centre for Blood Diseases, Monash University, Melbourne, Vic., Australia.
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21
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Ulfhammer E, Larsson P, Karlsson L, Hrafnkelsdóttir T, Bokarewa M, Tarkowski A, Jern S. TNF-alpha mediated suppression of tissue type plasminogen activator expression in vascular endothelial cells is NF-kappaB- and p38 MAPK-dependent. J Thromb Haemost 2006; 4:1781-9. [PMID: 16879221 DOI: 10.1111/j.1538-7836.2006.02035.x] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND Several proatherothrombotic conditions are associated with enhanced levels of circulating proinflammatory cytokines, which are believed to impair endothelial fibrinolytic capacity. OBJECTIVE This study aims at investigating how tumor necrosis factor (TNF)-alpha regulates endothelial gene expression of the key fibrinolytic enzyme tissue-type plasminogen activator (t-PA). METHODS Cultured human umbilical vein endothelial cells were pretreated with selective inhibitors of the three major inflammatory signaling pathways activated by TNF-alpha; the nuclear factor kappa-B (NF-kappaB), the p38 mitogen-activated protein kinase (p38 MAPK), and the c-jun N-terminal kinase (JNK) pathways. Following TNF-alpha stimulation, effects on t-PA gene expression were evaluated with real-time reverse transcriptase polymerase chain reaction and interactions of nuclear proteins with potential gene regulatory elements were studied with electrophoretic mobility shift assays. RESULTS Approximately 50% suppression of t-PA gene expression was observed after prolonged stimulation with TNF-alpha (> or =24 h). The repression was shown to be preferentially dependent on NF-kappaB activation, but also on p38 MAPK signaling. Further, we provide evidence for a TNF-alpha induced binding of NF-kappaB to the recently described kappaB site in the t-PA gene and of cyclic adenosine monophosphate response element binding protein (CREB) to the t-PA CRE-like site. CONCLUSIONS We conclude that TNF-alpha impairs fibrinolytic capacity in vascular endothelial cells by a NF-kappaB and p38 MAPK-dependent suppression of t-PA. This mechanism sheds a light on how inflammation contributes to the pathogenesis of cardiovascular diseases.
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Affiliation(s)
- E Ulfhammer
- Clinical Experimental Research Laboratory, Sahlgrenska University Hospital/Ostra, Göteborg University, Göteborg, Sweden
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22
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Liu HB, Hu YS, Medcalf RL, Simpson RW, Dear AE. Thiazolidinediones inhibit TNFalpha induction of PAI-1 independent of PPARgamma activation. Biochem Biophys Res Commun 2005; 334:30-7. [PMID: 15990085 DOI: 10.1016/j.bbrc.2005.06.055] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2005] [Accepted: 06/09/2005] [Indexed: 11/29/2022]
Abstract
Increased plasminogen activator inhibitor type 1 (PAI-1) levels are observed in endothelial cells stimulated by tumour necrosis factor alpha (TNFalpha). Thiazolidinediones (TZDs) may inhibit elevated endothelial cell PAI-1 accounting, in part, for the putative atheroprotective effects of TZDs. In an endothelial cell line, Rosiglitazone (RG) and Pioglitazone (PG) inhibited induction of PAI-1 by TNFalpha. The specific peroxisome proliferator-activated receptor gamma (PPARgamma) inhibitor, SR-202, failed to modulate this effect. RG also inhibited the effect of TNFalpha on a reporter gene construct harbouring the proximal PAI-1 promoter and PAI-1 mRNA in cells co-transfected with a dominant-negative PPARgamma construct. RG and PG attenuated TNFalpha-mediated induction of trans-acting factor(s) Nur77/Nurr1 and binding of nuclear proteins (NP) to the cis-acting element (NBRE). SR-202 failed to modulate these effects. The observations suggest TZDs inhibit TNFalpha-mediated PAI-1 induction independent of inducible PPARgamma activation and this may involve in the modulation of Nur77/Nurr1 expression and NP binding to the PAI-1 NBRE.
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Affiliation(s)
- H B Liu
- Australian Centre for Blood Diseases, Monash University, 6th Floor Burnet Tower, 89 Commercial Road, Prahran 3181, Melbourne, Victoria, Australia
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23
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Lux W, Klobeck HG, Daniel PB, Costa M, Medcalf RL, Schleuning WD. In vivo and in vitro analysis of the human tissue-type plasminogen activator gene promoter in neuroblastomal cell lines: evidence for a functional upstream kappaB element. J Thromb Haemost 2005; 3:1009-17. [PMID: 15869598 DOI: 10.1111/j.1538-7836.2005.01276.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Besides its well-established role in wound healing and fibrinolysis, tissue-type plasminogen activator (t-PA) has been shown to contribute to cognitive processes and memory formation within the central nervous system, and to promote glutamate receptor-mediated excitotoxicity. The t-PA gene is expressed and regulated in neuronal cells but the regulatory transcriptional processes directing this expression are still poorly characterized. We have used DNase I-hypersensitivity mapping and in vivo foot printing to identify putative regulatory elements and transcription factor binding sites in two human neuroblastomal (KELLY and SK-N-SH) and one human glioblastomal (SNB-19) cell lines. Hypersensitive sites were found in the proximal promoter region of all cell lines, and within the first exon for KELLY and SNB-19 cells. Mapping of methylation-protected residues in vivo detected a cluster of protected residues corresponding to a cAMP response element (CRE) and Sp1 sites in the proximal promoter previously shown to be essential for basal expression in other cell types. Protected residues were also found at other sites, notably a kappaB element at position bp -3081 to -3072 that was partly protected in KELLY and SNB-19 cells. Analysis of transfected reporter constructs in KELLY and SNB-19 cells confirmed that this particular element is functionally significant in the transactivation of the t-PA promoter in both cell types. This study defines, by in vivo and in vitro methods, a previously undescribed kappaB site in the t-PA gene promoter that influences t-PA expression in neuronal cells.
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Affiliation(s)
- W Lux
- Catenion Strategies GmbH, Berlin, Germany
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24
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Sheikh AM, Ochi H, Masuda J. Lysophosphatidylcholine induces tPA gene expression through CRE-dependent mechanism. Biochem Biophys Res Commun 2005; 329:71-7. [PMID: 15721275 DOI: 10.1016/j.bbrc.2005.01.094] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2005] [Indexed: 11/21/2022]
Abstract
Lysophosphatidylcholine (lysoPC) is implicated in the development of atherosclerosis and certain autoimmune diseases, and is reported to induce tissue-type plasminogen activator (tPA) at the protein level in endothelial cells. This study was designed to investigate the effect of lysoPC on tPA gene expression and the underlying molecular mechanisms in cultured endothelial cells. LysoPC transiently induced the mRNA expression of tPA in endothelial cells. LysoPC also induced the mRNA expression of urokinase-type plasminogen activator (uPA), uPA receptor, and plasminogen activator inhibitor-1, but the kinetics were different from that of tPA. Promoter analysis revealed that the cyclic AMP-responsive element of the tPA gene (tPACRE) is required for lysoPC-induced tPA expression. Furthermore, an electrophoresis mobility shift assay showed that lysoPC increased the binding activity of CRE binding protein to tPACRE. These results indicated that lysoPC transcriptionally upregulated the gene expression of tPA in endothelial cells, at least in part, via tPACRE activation.
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Affiliation(s)
- Abdullah Md Sheikh
- Department of Laboratory Medicine, Shimane University School of Medicine, Izumo, Japan
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25
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Stasinopoulos S, Tran H, Chen E, Sachchithananthan M, Nagamine Y, Medcalf RL. Regulation of protease and protease inhibitor gene expression: the role of the 3'-UTR and lessons from the plasminogen activating system. PROGRESS IN NUCLEIC ACID RESEARCH AND MOLECULAR BIOLOGY 2005; 80:169-215. [PMID: 16164975 DOI: 10.1016/s0079-6603(05)80005-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Affiliation(s)
- Stan Stasinopoulos
- Friedrich Miescher Institute, Novartis Research Foundation, Maulbeerstrasse 66, CH-4058 Basel, Switzerland
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26
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Pham NL, Franzen A, Levin EG. NF1 Regulatory Element Functions as a Repressor of Tissue Plasminogen Activator Expression. Arterioscler Thromb Vasc Biol 2004; 24:982-7. [PMID: 15044208 DOI: 10.1161/01.atv.0000126679.70877.d0] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
OBJECTIVE Analysis of the distribution of endothelial cell tissue plasminogen activator (tPA) in the vasculature of rodents and primates demonstrated that tPA is constitutively expressed predominantly in small artery endothelial cells of brain and lung. The regulatory elements responsible for the highly selective expression of arterial endothelial cell tissue plasminogen activator were sought. METHODS AND RESULTS Transcription factor binding sites were defined by electrophoretic mobility-shift assay (EMSA) analysis using rat lung and brain nuclear extracts and the tPA promoter sequence from -609 to +37 bp. Protein binding to the promoter was found to be mediated by an NF1 site between -158 and -145 bp upstream from the transcriptional start site. Specific binding was confirmed through mutational analysis and competition binding studies. Infection of endothelial cells with a tPA promoter-green fluorescent protein (GFP) (-609 to +37 bp) reporter construct resulted in expression of the GFP, whereas no expression was found in smooth muscle cells. Mutation of the NF1 site increased the GFP expression indicating that the element acts as a repressor. CONCLUSIONS These results suggest that the 600 bp of the tPA promoter upstream of the transcription start site conveys cell specificity to tPA expression and that an NF1 site within this region acts as a repressor.
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MESH Headings
- Animals
- Base Sequence
- Binding Sites
- Binding, Competitive
- Cell Line
- Consensus Sequence
- DNA-Binding Proteins/metabolism
- Electrophoretic Mobility Shift Assay
- Endothelial Cells/cytology
- Endothelial Cells/metabolism
- Endothelium, Vascular/cytology
- Endothelium, Vascular/metabolism
- Gene Expression Regulation/genetics
- Gene Silencing
- Genes, Reporter
- Green Fluorescent Proteins
- HeLa Cells
- Humans
- Luminescent Proteins/biosynthesis
- Luminescent Proteins/genetics
- Mice
- Molecular Sequence Data
- Muscle, Smooth, Vascular/cytology
- Muscle, Smooth, Vascular/metabolism
- Myocytes, Smooth Muscle/cytology
- NFI Transcription Factors
- Organ Specificity
- Promoter Regions, Genetic/genetics
- Protein Binding
- Rats
- Regulatory Sequences, Nucleic Acid
- Sequence Alignment
- Sequence Homology, Nucleic Acid
- Tissue Plasminogen Activator/biosynthesis
- Tissue Plasminogen Activator/genetics
- Transcription Factors/metabolism
- Transfection
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Affiliation(s)
- Nhat-Long Pham
- Division of Vascular Biology, La Jolla Institute for Molecular Medicine, San Diego Calif 92121, USA
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27
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Sadowski T, Steinmeyer J. Effects of polysulfated glycosaminoglycan and triamcinolone acetonid on the production of proteinases and their inhibitors by IL-1alpha treated articular chondrocytes. Biochem Pharmacol 2002; 64:217-27. [PMID: 12123742 DOI: 10.1016/s0006-2952(02)01073-0] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
In this study we determined the in vitro effects of polysulfated glycosaminoglycan (PSGAG) and the glucocorticoid triamcinolone acetonid (TA) on the IL-1 altered expression and activity of matrix metalloproteinases (MMP-1, MMP-3), tissue inhibitor of metalloproteinases-1, the plasminogen activators tPA and uPA and plasminogen activator inhibitor 1 by articular chondrocytes. Bovine chondrocytes were cultured in alginate gel beads. Cells were treated with interleukin-1alpha (IL-1alpha) in the presence of vehicle or drugs at various concentrations. After 48hr mRNA expression of MMP-1, MMP-3, TIMP-1, uPA, tPA and PAI-1 was analyzed by RT-PCR-ELISA. The protein synthesis of TIMP-1 and MMP-3 was determined by immunoprecipitation, PAI-1 protein was quantitated by ELISA. The activity of enzymes and inhibitors was measured by functional assays. Treating chondrocytes with IL-1 induced the expression of MMPs and downregulated TIMP-1 but stimulated both the expression of PAs and PAI-1. Both drugs significantly reduced collagenase and proteoglycanase activities which was accompanied by inhibition of the expression of MMP-1 and MMP-3. The IL-1 decreased expression of TIMP-1 was further reduced by TA, which resulted in a significant loss of TIMP activity. No effects on TIMP activity or TIMP-1 biosynthesis were observed after treatment of chondrocytes with PSGAG. Both drugs inhibited the IL-1-induced mRNA expression of tPA, whereas expression of uPA was only mildly reduced by PSGAG, which also induced PAI-1 above IL-1 stimulated levels. As inhibition of collagenase activities and tPA expression by PSGAG occurred at physiological concentrations it might be of clinical relevance, indicating that PSGAG could help reducing cartilage degradation and has a strong anti-fibrinolytic potential. Due to their co-regulation of MMPs and TIMP(s) glucocorticoids should be carefully studied for their overall effect on extracellular matrix proteolysis.
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Affiliation(s)
- Thorsten Sadowski
- Institute of Pharmacology and Toxicology, University of Bonn, Bonn, Germany.
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28
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Yu H, Schleuning WD, Michl M, Liberatore G, Tan SS, Medcalf RL. Control elements between -9.5 and -3.0 kb in the human tissue-type plasminogen activator gene promoter direct spatial and inducible expression to the murine brain. Eur J Neurosci 2001; 14:799-808. [PMID: 11576184 DOI: 10.1046/j.0953-816x.2001.01700.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Tissue-type plasminogen activator (t-PA) participates in the control of synaptic plasticity and memory formation in the central nervous system (CNS). Transgenic mice harbouring either 9.5, 3.0 or 1.4 kb of the human t-PA promoter fused to the LacZ reporter gene were used to assess t-PA promoter-directed expression in vivo. The 9.5 kb t-PA promoter directed expression to the brain, most notably to the dentate gyrus, superior colliculus, hippocampus, thalamus and piriform cortex. Staining was also observed in the retrosplenial and somatosensory cortex. The 3.0 kb t-PA promoter directed generalized and poorly defined expression to the cortex and hippocampus, while the 1.4 kb t-PA promoter directed expression selectively to the medial habenula. Intravenous administration of lipopolysaccharide into mice harbouring the 9.5 kb t-PA promoter resulted in an increase in reporter gene activity in the lateral orbital cortex and thalamus. Results of in vitro transfection experiments of NT2 cells with a series of t-PA promoter deletion constructs confirmed the presence of regulatory elements throughout the 9.5 kb promoter region. Finally, we describe a cis-acting element related to the NFAT recognition site that provides a protein-binding site and which may play a role in the selective expression of the 1.4 t-PA promoter in the medial habenula. These results indicate that elements between -3.0 and -9.5 kb of the t-PA promoter confer constitutive and inducible expression to specific regions of the CNS.
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Affiliation(s)
- H Yu
- Monash University Department of Medicine, Box Hill Hospital, Arnold Street, Box Hill 3128, Victoria, Australia
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29
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Costa M, Medcalf RL. Ectopic expression of the cAMP-responsive element binding protein inhibits phorbol ester-mediated induction of tissue-type plasminogen activator gene expression. EUROPEAN JOURNAL OF BIOCHEMISTRY 2001; 268:987-96. [PMID: 11179965 DOI: 10.1046/j.1432-1327.2001.01957.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The human tissue-type plasminogen activator (t-PA) gene is regulated in a cell-type dependent manner. The t-PA gene is transcriptionally induced by the phorbol ester PMA in HeLa cells, but suppressed by PMA in HT-1080 cells. A cAMP responsive element (tPACRE) and a Sp-1 site located within the proximal t-PA gene promoter are functionally important in both cell systems. HeLa and HT-1080 cells contain a different repertoire of factors that associate with the tPACRE. In HT-1080 cells, CREB and c-Jun are the two major t-PACRE binding proteins identified, while activating transcription factor 2 (ATF-2) is a predominant t-PACRE binding protein in HeLa cells. To determine whether alteration in the distribution of tPACRE binding proteins would influence the differential regulation of the t-PA gene in these cells, the tPACRE binding profiles in these two cell systems were manipulated by over expressing ATF-2 in HT-1080 cells and CREB in HeLa cells. Supershift experiments confirmed that the overexpression of these factors resulted in binding to the tPACRE site. However, the presence of ATF-2 in HT-1080 cells did not affect either constitutive or PMA-mediated suppression of the endogenous t-PA gene. In contrast, enforced tPACRE-binding activity of CREB in HeLa cells significantly reduced the magnitude of PMA-mediated induction of t-PA mRNA in HeLa cells. These results indicate that the introduction of CREB into HeLa cells disrupts the regulation of the t-PA gene.
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Affiliation(s)
- M Costa
- Monash University Department of Medicine, Box Hill Hospital, Box Hill, Victoria, Australia
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30
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Fujimori K, Kanaoka Y, Sakaguchi Y, Urade Y. Transcriptional activation of the human hematopoietic prostaglandin D synthase gene in megakaryoblastic cells. Roles of the oct-1 element in the 5'-flanking region and the AP-2 element in the untranslated exon 1. J Biol Chem 2000; 275:40511-6. [PMID: 10998423 DOI: 10.1074/jbc.m007688200] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The human hematopoietic prostaglandin D synthase (H-PGDS) gene is highly expressed in human megakaryoblastic cells, in which phorbol ester induces its expression. We characterized the promoter activity of the 5'-flanking region and the untranslated exon 1 (-1044 to +290) of the human H-PGDS gene in human megakaryoblastic Dami cells. Transient expression analysis using the luciferase reporter gene revealed that the 5'-flanking region and the untranslated exon 1 were sufficient for efficient expression of the H-PGDS gene in Dami cells, but not in monocytic U937 cells. Deletion and site-directed mutagenesis of the Oct-1 element in the 5'-flanking region decreased the promoter activity by approximately 30% compared with that of the entire region from -1044 to +290. An electrophoretic mobility shift assay demonstrated that Oct-1 specifically bound to the promoter region. Interestingly, even only untranslated exon 1 (+1 to +290) showed approximately 60% of the promoter activity of the entire region from -1044 to +290. Site-directed mutagenesis of the AP-2 element within the untranslated exon 1 abolished the basal promoter activity as well as its phorbol ester-mediated up-regulation. In AP-2-deficient HepG2 cells, the H-PGDS promoter activity was enhanced by coexpression with AP-2alpha. These findings indicate that the Oct-1 element in the 5'-flanking region acts as a positive cis-acting element and that the AP-2 element in the untranslated exon 1 is crucial for both basal and phorbol ester-mediated up-regulation of human H-PGDS gene expression in megakaryoblastic Dami cells.
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Affiliation(s)
- K Fujimori
- Department of Molecular Behavioral Biology and the Core Research for Evolutional Science and Technology, Japan Science and Technology Corporation, Osaka Bioscience Institute, 6-2-4 Furuedai, Suita, Osaka 565-0874, Japan
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Mintz-Weber CS, Johnson JP. Identification of the elements regulating the expression of the cell adhesion molecule MCAM/MUC18. Loss of AP-2 is not required for MCAM expression in melanoma cell lines. J Biol Chem 2000; 275:34672-80. [PMID: 10938273 DOI: 10.1074/jbc.m003812200] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The cell adhesion molecule melonoma cell adhesion molecule (MCAM)/MUC18/CD146 is specifically up-regulated on tumors of neuroectodermal origin and in animal models confers metastatic capacity to human melanoma cells. To identify critical regions regulating MCAM expression in melanomas, 1 kilobase of the MCAM 5' region was analyzed for promoter activity and transcription factor binding in 1 glioma, 1 carcinoma, and 4 melanoma cell lines. The minimal MCAM promoter (-106/+22 base pair (bp)) consists of 4 Sp-1 sites, two AP-2 elements, one cAMP responsive element, and the initiator surrounding the transcriptional start site. Analysis of mutated constructs indicated that the cAMP-responsive element is a major transcriptional activator in the majority of cell lines. Site-directed mutagenesis revealed that, in AP-2 expressing cells, the AP-2 site within the core promoter (-23 bp) has an inhibitory influence on MCAM expression while the AP-2 sites at -131 and -302 bp are activating. Functional AP-2 was observed in both MCAM positive and MCAM negative melanoma cell lines indicating that expression of MCAM does not require loss of this transcription factor. Furthermore, all MCAM constructs were strongly expressed in MCAM negative as well as MCAM positive cells, indicating that the expression of this gene is not controlled solely by the presence of transactivating factors binding to the investigated region.
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Affiliation(s)
- C S Mintz-Weber
- Institute for Immunology, University of Munich, Munich 80336, Germany
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Gravel M, Gao E, Hervouet-Zeiber C, Parsons V, Braun PE. Transcriptional regulation of 2',3'-cyclic nucleotide 3'-phosphodiesterase gene expression by cyclic AMP in C6 cells. J Neurochem 2000; 75:1940-50. [PMID: 11032883 DOI: 10.1046/j.1471-4159.2000.0751940.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
It was recently shown that the two transcripts encoding the isoforms of 2',3'-cyclic nucleotide 3'-phosphodiesterase (CNP1 and CNP2) are differentially regulated during the process of oligodendrocyte maturation. In oligodendrocyte precursors, only CNP2 mRNA is present, whereas in differentiating oligodendrocytes, both CNP1 and CNP2 mRNAs are expressed. This pattern of CNP expression is likely due to stage-specific transcriptional regulation of the two CNP promoters during the process of oligodendrocyte differentiation. Here, we report the influence of increased intracellular cyclic AMP (cAMP) levels on the transcription of both CNP1 and CNP2 mRNAs in rat C6 glioma cells. We found that the transcription of CNP1 mRNA was significantly increased in comparison with that of CNP2 mRNA in cells treated with cAMP analogues to elevate intracellular cAMP levels. This up-regulation of CNP1 expression (a) is due to an increase of transcription, (b) requires de novo protein synthesis, and (c) requires the activity of protein kinase A. These results are physiologically significant and support the idea that a cAMP-mediated pathway is part of the molecular mechanisms regulating the expression of CNP1 in oligodendrocytes. The regulation of CNP1 promoter activity by cAMP was then investigated in stably transfected C6 cell lines containing various deletions of the CNP promoter directing the bacterial chloramphenicol acetyltransferase gene. We showed that the sequence between nucleotides -126 and -102 was essential for the cAMP-dependent induction of CNP1 expression. Gel retardation analysis showed that two protein-DNA complexes are formed between this sequence and nuclear factors from C6 cells treated or not treated with cAMP. This suggests that the induction of CNP1 mRNA transcription is not mediated by changes in binding of nuclear factors that interact directly with the -126/-102 sequence. Sequence analysis of this region revealed the presence of a putative activator protein-2 (AP-2) binding site. It is interesting that mutagenesis of this region resulted in a significant reduction in transcriptional responses to cAMP, implying a possible role for the AP-2 factor in the expression of CNP1. In addition, we have shown that putative binding sites for activator protein-4 and nuclear factor-1 adjacent to the AP-2 site are required for efficient induction of CNP1 expression by cAMP. Taken together, our results show that the cAMP-dependent accumulation of CNP1 mRNA appears to depend on the synergistic interaction of several regulatory elements.
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Affiliation(s)
- M Gravel
- Department of Biochemistry, McGill University, Montreal, Quebec, Canada.
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Costa M, Shen Y, Medcalf RL. Overexpression of a dominant negative CREB protein in HT-1080 cells selectively disrupts plasminogen activator inhibitor type 2 but not tissue-type plasminogen activator gene expression. FEBS Lett 2000; 482:75-80. [PMID: 11018526 DOI: 10.1016/s0014-5793(00)02030-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The tissue-type plasminogen activator (t-PA) and plasminogen activator inhibitor type 2 (PAI-2) genes are differentially regulated by 12-phorbol 13-myristate acetate (PMA) in HT-1080 fibrosarcoma cells. PMA transcriptionally down-regulates the t-PA gene in HT-1080 cells, while the PAI-2 gene is simultaneously induced by this agonist. The t-PA and PAI-2 gene promoters harbour a cAMP-response element (CRE) which influences the expression of both genes. We have compared the binding activity of nuclear factors that recognise these CRE sites. We show that CREB (CRE binding protein) recognises each CRE and that the degree of constitutive Ser119-phosphorylated t-PA CRE-bound CREB was greater than for PAI-2 CRE bound CREB. Stable transfection of HT-1080 cells with a plasmid containing a CREB that could not be phosphorylated on Ser119 (pCI-CREB(ala119)) did not influence PMA-mediated suppression of t-PA mRNA, but markedly impaired PMA-mediated induction of PAI-2 mRNA. Our results demonstrate that the Ser119 residue of CREB plays a crucial role in PMA-mediated induction of PAI-2 gene expression, whereas PMA-mediated suppression of t-PA in HT-1080 cells requires a different process.
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Affiliation(s)
- M Costa
- Monash University Department of Medicine, 5th Floor Clive Ward Centre, Box Hill Hospital, Arnold Street, Box Hill, Vic. 3128, Australia
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Dear AE, Medcalf RL. The novel anti-tumour agent oxamflatin differentially regulates urokinase and plasminogen activator inhibitor type 2 expression and inhibits urokinase-mediated proteolytic activity. BIOCHIMICA ET BIOPHYSICA ACTA 2000; 1492:15-22. [PMID: 11004477 DOI: 10.1016/s0167-4781(00)00041-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Cell surface, urokinase (u-PA)-mediated, plasminogen activation has recently been recognised as a process integral to extracellular matrix degradation. The primary inhibitor of u-PA activity in the extracellular matrix is plasminogen activator inhibitor type 2 (PAI-2), a serine protease inhibitor. The malignant metastatic phenotype is associated with excessive and uncontrolled, tumour cell-associated, u-PA-mediated, extracellular matrix degradation. Inhibition of the malignant metastatic phenotype via induction of PAI-2 expression and/or inhibition of u-PA expression may represent a novel means via which the metastatic phenotype can be arrested. Agents capable of inducing PAI-2 and/or inhibiting u-PA activity may restrict u-PA-mediated tumour cell proteolysis and facilitate in the development of therapeutic strategies to combat malignant disease. We have identified the hydroxamic acid derivative oxamflatin, previously noted to revert the malignant phenotype in K-ras-transformed NIH-3T3 cells, as capable of upregulating PAI-2 and simultaneously suppressing u-PA expression in two different cell systems. In addition, zymographic analysis indicated that oxamflatin treatment results in a significant reduction in u-PA proteolytic activity in both HT-1080 fibrosarcoma and U-937 histiocytic lymphoma cells. We postulate that oxamflatin represents a novel means by which induction of PAI-2 and concomitant inhibition of u-PA gene and protein expression can be achieved and may be of benefit in inhibiting the malignant metastatic phenotype.
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Affiliation(s)
- A E Dear
- Department of Medicine, Monash University, Box Hill, Victoria 3128, Australia.
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Kramer PR, Guerrero G, Krishnamurthy R, Mitchell PJ, Wray S. Ectopic expression of luteinizing hormone-releasing hormone and peripherin in the respiratory epithelium of mice lacking transcription factor AP-2alpha. Mech Dev 2000; 94:79-94. [PMID: 10842061 DOI: 10.1016/s0925-4773(00)00316-6] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
The vertebrate transcription factor activator protein-2 (AP-2alpha) is involved in craniofacial morphogenesis. In the nasal placode AP-2alpha expression delineates presumptive respiratory epithelia from olfactory epithelia, with AP-2alpha expression restricted to the anterior region of the respiratory epithelium (absent from the olfactory epithelium) at later stages. To address the role AP-2alpha plays in differentiation of cell groups in the nasal placode, the spatiotemporal expression pattern of four markers normally associated with olfactory epithelial structures was analyzed in mice lacking AP-2alpha. These markers were the intermediate filament protein peripherin, the neuropeptide luteinizing hormone-releasing hormone (LHRH), the neural cell adhesion molecule (NCAM) and the olfactory transcription factor Olf-1. Development of cells expressing these markers was similar in both genotypes until embryonic day 12.5 (E12.5), indicating that the main olfactory epithelium and olfactory pit formation was normal. At E13.5 in mutant mice, ectopic LHRH neurons and peripherin axons were detected in respiratory epithelial areas, areas devoid of Olf-1 and NCAM staining. Over the next few days, an increase in total nasal LHRH neurons occurred. The increase in nasal LHRH neurons could be accounted for by LHRH neurons arising and migrating out of respiratory epithelial regions on peripherin-positive fibers. These results indicate that AP-2alpha is not essential for the separation of the olfactory and respiratory epithelium from the nasal placode and is consistent with AP-2alpha preventing recapitulation of developmental programs within the respiratory epithelium that lead to expression of LHRH and peripherin phenotypes.
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Affiliation(s)
- P R Kramer
- Cellular and Developmental Neurobiology Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20895, USA
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36
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Tabengwa EM, Benza RL, Grenett HE, Booyse FM. Hypertriglyceridemic VLDL downregulates tissue plasminogen activator gene transcription through cis-repressive region(s) in the tissue plasminogen activator promoter in cultured human endothelial cells. Arterioscler Thromb Vasc Biol 2000; 20:1675-81. [PMID: 10845888 DOI: 10.1161/01.atv.20.6.1675] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The relationship between tissue plasminogen activator (tPA) levels and the potential regulation by hypertriglyceridemic very low density lipoprotein (HTG-VLDL) was examined in a human umbilical vein endothelial cell (HUVEC) culture model system. HUVEC cultures were incubated in the absence/presence of HTG-VLDL or normal (NTG)-VLDL (0 to 50 microg/mL) at 37 degrees C for various times (0 to 24 hours), followed by analyses of tPA antigen (ELISA), mRNA (reverse transcription-polymerase chain reaction), endothelial cell surface-localized plasmin generation assays, and nuclear transcription run-on assays. Secreted tPA antigen levels decreased approximately 53% (3.3+/-0.14 versus 6.97+/-0.42 microg/mL) and mRNA levels decreased approximately 70% in HTG-VLDL-treated HUVECs compared with NTG-VLDL-treated and culture medium control cells. Decreased tPA antigen and mRNA expression was associated with a concomitant approximately 98% decrease in tPA-mediated plasmin generation in HTG-VLDL-treated HUVEC cultures. Nuclear transcription run-on assays demonstrated that HTG-VLDL decreased tPA gene transcription approximately 73% (tPA mRNA/GAPDH mRNA) in cultured HUVECs. To identify and localize the repressive element(s) in the tPA promoter responsive to HTG-VLDL, a tPA promoter/luciferase construct (ptPA222/luc) was generated. HUVECs transiently transfected with this construct were incubated in the absence/presence of HTG-VLDL or NTG-VLDL (20 microg/mL). HTG-VLDL decreased promoter activity approximately 52% to 57% in the ptPA222/luc-transfected cells compared with NTG-VLDL-treated or buffer control cells. These results indicate that the 2.2-kb fragment of the promoter and 5' flanking region of the tPA gene contains the repressive sequences that direct the transcriptional downregulation of the tPA promoter. Data from these studies suggest that the repression of tPA gene expression by HTG-VLDL may contribute to the impaired fibrinolysis often associated with hypertriglyceridemia.
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Affiliation(s)
- E M Tabengwa
- Division of Cardiovascular Disease, University of Alabama at Birmingham, USA. uab.edu
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37
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Kramer PR, Krishnamurthy R, Mitchell PJ, Wray S. Transcription factor activator protein-2 is required for continued luteinizing hormone-releasing hormone expression in the forebrain of developing mice. Endocrinology 2000; 141:1823-38. [PMID: 10803593 DOI: 10.1210/endo.141.5.7452] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
LHRH is the neuropeptide responsible for reproductive function. Prenatally, LHRH expression begins when neurons are in the olfactory pit and continues as these cells migrate into the brain. Thus, LHRH neurons maintain neuropeptide expression through very distinct environments. The regulatory interactions that control onset and continued expression of the LHRH phenotype are unknown. To begin to address this question primary LHRH neurons were removed from nasal explants at different ages. A complementary DNA (cDNA) subtraction screen was performed comparing a 3.5-days in vitro LHRH neuron [approximately embryonic day 15 (E15) in vivo] to two 10.5-days in vitro LHRH neurons (approximately postnatal day 1 in vivo). The transcription factor activator protein-2 (AP-2alpha) was differentially expressed and was present in the developmentally younger LHRH neuron. In vivo analysis revealed that LHRH neurons expressed AP-2 as they migrated across the cribriform plate and into the forebrain beginning on E13.5, but that coexpression of LHRH and AP-2 was no longer detected in postnatal day 1 animals. This suggested a regulatory role for AP-2 in LHRH neurons. Analysis of animals lacking AP-2alpha revealed a dramatic decrease in forebrain LHRH neurons between E13.5 and E14.5, correlating with normal onset of AP-2 expression in LHRH neurons as they entered the central nervous system. Nasal cells robustly expressing LHRH were still present on E 14.5. The continued presence of forebrain LHRH cells is proposed based on a second marker, galanin, and lack of increased apoptotic/necrotic cells in this region. A decrease in LHRH messenger RNA in forebrain neurons indicates regulation of LHRH occurred at the transcriptional or posttranscriptional level in mutant animals. These results indicate a developmentally restricted involvement of the transcription factor AP-2 in LHRH expression once the LHRH neurons have migrated into the forebrain, but before establishment of an adult-like distribution.
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Affiliation(s)
- P R Kramer
- Cellular and Developmental Neurobiology Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland 20892-4156, USA
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Koziczak M, Krek W, Nagamine Y. Pocket protein-independent repression of urokinase-type plasminogen activator and plasminogen activator inhibitor 1 gene expression by E2F1. Mol Cell Biol 2000; 20:2014-22. [PMID: 10688648 PMCID: PMC110818 DOI: 10.1128/mcb.20.6.2014-2022.2000] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Expression of genes of the plasminogen activator (PA) system declines at the G(0)/G(1)-S-phase boundary of the cell cycle. We found that overexpression of E2F1-3, which acts mainly in late G(1), inhibits promoter activity and endogenous expression of the urokinase-type PA (uPA) and PA inhibitor 1 (PAI-1) genes. This effect is dose dependent and conserved in evolution. Mutation analysis indicated that both the DNA-binding and transactivation domains of E2F1 are necessary for this regulation. Interestingly, an E2F1 mutant lacking the pRB-binding region strongly repressed the uPA and PAI-1 promoters. An E2F-mediated negative effect was also observed in pRB and p107/p130 knockout cell lines. This is the first report that E2F can act as a repressor independently of pocket proteins. Mutation of AP-1 elements in the uPA promoter abrogated E2F-mediated transcriptional inhibition, suggesting the involvement of AP-1 in this regulation. Results shown here identify E2F as an important component of transcriptional control of the PA system and thus provide new insights into mechanisms of cellular proliferation.
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Affiliation(s)
- M Koziczak
- Friedrich Miescher Institute, Basel, Switzerland
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Merchiers P, Bulens F, Stockmans I, De Vriese A, Convents R, Bouillon R, Collen D, Belayew A, Carmeliet G. 1,25-Dihydroxyvitamin D(3) induction of the tissue-type plasminogen activator gene is mediated through its multihormone-responsive enhancer. FEBS Lett 1999; 460:289-96. [PMID: 10544252 DOI: 10.1016/s0014-5793(99)01337-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
Tissue-type plasminogen activator (t-PA) is a positive modulator of the plasminogen-plasmin system, which is involved in bone remodeling. In the present study, 1,25-dihydroxyvitamin D(3) [1,25(OH)(2)D(3)] was found to stimulate t-PA gene expression in ROS17/2.8 osteosarcoma cells. Transient transfection analysis and in vitro DNA binding studies identified two vitamin D-responsive elements (VDRE) in the human t-PA enhancer. The first VDRE (bp -7175 to -7146) comprised an inverted palindrome separated by 9 bp (IP9) overlapping a palindrome separated by 3 bp. The second VDRE (bp -7315 to -7302) is an IP2 element overlapping the previously identified retinoic acid-responsive element. 1,25(OH)(2)D(3) treatment of primary osteoblasts derived from t-PAlacZ transgenic mice containing 9 kb of 5' sequence of the human t-PA gene increased the number of lacZ-positive cells, fitting with the probability model of enhancer function.
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Affiliation(s)
- P Merchiers
- Center for Molecular and Vascular Biology, University of Leuven, Campus Gasthuisberg, O and N, Herestraat 49, B-3000, Leuven, Belgium
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Merchiers P, Bulens F, De Vriese A, Collen D, Belayew A. Involvement of Sp1 in basal and retinoic acid induced transcription of the human tissue-type plasminogen activator gene. FEBS Lett 1999; 456:149-54. [PMID: 10452548 DOI: 10.1016/s0014-5793(99)00942-4] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Transcription of the human tissue-type plasminogen activator (t-PA) gene is regulated by a multi-hormonal responsive enhancer at -7 kb. Transient co-transfections of Drosophila SL2 and human HT1080 fibrosarcoma cells with t-PA reporter constructs showed that Sp1 and Sp3 activate the t-PA promoter. Moreover Sp1 (but not Sp3) binding to the promoter is involved in induction by retinoic acid (RA), a response mediated through the enhancer. The role of Sp1 is specific, since mutation of the CRE element in the promoter did not affect response to RA. In contrast, the glucocorticoid induction mediated by the enhancer is independent of these Sp1 and CRE elements.
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Affiliation(s)
- P Merchiers
- Center for Molecular and Vascular Biology, University of Leuven, Belgium
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Xavier-Neto J, Pereira AC, Junqueira ML, Carmona R, Krieger JE. Rat angiotensin-converting enzyme promoter regulation by beta-adrenergics and cAMP in endothelium. Hypertension 1999; 34:31-8. [PMID: 10406820 DOI: 10.1161/01.hyp.34.1.31] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
To shed light on mechanisms of angiotensin-converting enzyme (ACE) upregulation, we used a rabbit endothelial cell model to characterize intracellular pathways of beta-adrenergic stimulation. In these cells, ACE activity is increased by isoproterenol (ISO). The stably transfected 1273-bp ACE promoter is stimulated by ISO in the presence of isobutyl methylxanthine. This effect is abolished by propranolol. Promoter stimulation is mimicked by cholera toxin, forskolin, and 8BrcAMP, but not by 8BrcGMP. Promoter stimulation by ISO and isobutyl methylxanthine is blocked by protein kinase A inhibitors, indicating that beta-adrenergic stimulation of the ACE gene depends on phosphorylation of protein kinase A targets. Activation by cAMP, resistance to phorbol ester, and lack of synergism between cAMP and phorbol ester suggest that promoter regulation is due to cAMP responsive element rather than to activating protein-2 sequences. Okadaic acid potentiation of 8BrcAMP induction indicated that promoter activation by cAMP is regulated by phosphatases controlling activation of typical cAMP responsive element regulated genes. In summary, beta-adrenergic activation of rat ACE promoter is specific; uses G(s) proteins, adenylyl cyclase, protein kinase A; and probably includes cAMP responsive element-like sequences.
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Affiliation(s)
- J Xavier-Neto
- Laboratório de Genética e Cardiologia Molecular e Dept Clínica Médica/LIM 13, Instituto do Coração, Faculdade de Medicina da Universidade de São Paulo, São Paulo, Brazil
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Miyamoto A, Yang SX, Laufs U, Ruan XL, Liao JK. Activation of guanine nucleotide-binding proteins and induction of endothelial tissue-type plasminogen activator gene transcription by alcohol. J Biol Chem 1999; 274:12055-60. [PMID: 10207029 DOI: 10.1074/jbc.274.17.12055] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The mechanism by which moderate alcohol ingestion lowers the risk of cardiovascular disease is unknown but may be due, in part, to the ability of alcohol to increase the level of tissue-type plasminogen activator (t-PA). Human endothelial cells were treated with low concentrations of ethanol (0.25-25 mM, 0-24 h), which are associated with moderate alcohol consumption. Although treatment with ethanol alone did not affect t-PA gene transcription or mRNA expression, it augmented isoproterenol (ISO)-stimulated t-PA gene transcription and mRNA levels by 3.4- and 2.8-fold, respectively, and decreased plasminogen activator inhibitor-1 mRNA levels by 65%. These effects of ethanol correlated with 2.5- and 6.9-fold increases in ISO-stimulated cyclic AMP levels and 4x-cyclic AMP response element heterologous promoter activity, respectively. To determine whether alcohol-induced changes in agonist-stimulated cyclic AMP levels were because of modulation of guanine nucleotide-binding proteins (G proteins), we assessed the effects of ethanol on Galphas and Galphai2. Although ethanol did not affect the expression of Galphas or Galphai2, it increased ISO-stimulated Galphas GTPase and GTP binding activity by 2.2- and 2.9-fold and decreased UK14304-stimulated Galphai2 GTPase and GTP binding activity by 38 and 80%. These results indicate that treatment with relatively low concentrations of ethanol enhances agonist-stimulated cyclic AMP-dependent t-PA gene transcription in vascular endothelial cells through differential modulation of G protein.
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Affiliation(s)
- A Miyamoto
- Department of Veterinary Pharmacology, Kagoshima University, Kagoshima 890-0065, Japan
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43
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Priglinger U, Binder BR. Gewebeplasminogenaktivator: Biochemie, Molekularbiologie und Physiologie. Hamostaseologie 1999. [DOI: 10.1007/978-3-662-07673-6_49] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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Kasho M, Sakai M, Sasahara T, Anami Y, Matsumura T, Takemura T, Matsuda H, Kobori S, Shichiri M. Serotonin enhances the production of type IV collagen by human mesangial cells. Kidney Int 1998; 54:1083-92. [PMID: 9767524 DOI: 10.1046/j.1523-1755.1998.00114.x] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
BACKGROUND The plasma concentration of 5-hydroxytryptamine (5-HT) in diabetic patients is higher than that in normal subjects. Since recent reports have demonstrated the presence of 5-HT2A receptor in glomerular mesangial cells, it is possible that 5-HT may be involved in the development of diabetic nephropathy through the 5-HT2A receptor in mesangial cells. Because expansion of the glomerular mesangial lesion is a characteristic feature of diabetic nephropathy, we examined the effect of 5-HT on the production of type IV collagen by human mesangial cells. METHODS Human mesangial cells were incubated with 5-HT with or without 5-HT receptor antagonists, protein kinase C (PKC) inhibitor or transforming growth factor-beta (TGF-beta) antibody. Type IV collagen mRNA and protein concentration in medium were measured by Northern blot analysis and enzyme-linked immunosorbent assay (ELISA), respectively. TGF-beta mRNA and bioactivity in the medium were measured by Northern blot analysis and bioassay using mink lung epithelial cells, respectively. RESULTS 5-HT stimulated the production of type IV collagen by human mesangial cells, which was inhibited by ketanserin and sarpogrelate hydrochloride, 5-HT2A receptor antagonists, but not by ondansetron, a 5-HT3 receptor antagonist. 5-HT increased the bioactivities of both active and total TGF-beta. However, the 5-HT-enhanced production of type IV collagen was completely inhibited by an anti-TGF-beta antibody. Furthermore, a PKC inhibitor, calphostin C, inhibited the 5-HT-induced increase in type IV collagen secretion, and the activity of membrane PKC was increased by 5-HT. Phorbol ester activated type IV collagen production as well as active and total TGF-beta. Calphostin C completely inhibited the 5-HT-enhanced activity of active TGF-beta, but did not inhibit exogenous TGF-beta-induced increase in type IV collagen secretion. CONCLUSIONS Our results suggest that 5-HT-enhanced production of type IV collagen by human mesangial cells is mediated by activation of PKC and subsequent increase in active TGF-beta activity.
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Affiliation(s)
- M Kasho
- Department of Metabolic Medicine, Kumamoto University School of Medicine, Honjo, Japan
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Ardekani AM, Romanelli JC, Mayo KE. Structure of the rat inhibin and activin betaA-subunit gene and regulation in an ovarian granulosa cell line. Endocrinology 1998; 139:3271-9. [PMID: 9645703 DOI: 10.1210/endo.139.7.6116] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
We have isolated the rat inhibin and activin betaA-subunit gene, which is composed of three exons, and have characterized a 571-bp region upstream from the transcriptional start site that functions as a promoter in transient transfection studies in an ovarian granulosa cell line, GRMO2. Deletion analysis of the 571-bp promoter region has identified DNA sequences between -362 bp and -110 bp to be essential in mediating basal promoter activity and activation by forskolin (FSK) and/or 12-O-tetradecanoylphorbol-13-acetate (TPA). Within this region, a variant CRE (cAMP response element) has been identified at -120 bp. Point mutations in the variant CRE substantially reduce the ability of FSK and/or TPA to induce promoter activity in GRMO2 cells. A single nucleotide change in the variant CRE, which converts it to a consensus CRE, does not enhance promoter activity in response to FSK and/or TPA, but rather reduces promoter activity to the same extent as the other inactivating mutation in the variant CRE, suggesting that this element does not act as a classical CRE. Consistent with this, electrophoretic mobility shift assays performed using antibodies to a variety of cAMP and phorbol ester-responsive transcription factors indicate that the AP-1 family proteins jun-B and fos-B are present in the protein complex binding to the variant CRE. Overexpression of jun-B and fos-B in GRMO2 cells resulted in a robust activation of the betaA-subunit promoter. Our results suggest that this novel variant CRE sequence mediates both cAMP and phorbol ester regulation through its interactions with AP-1family proteins.
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Affiliation(s)
- A M Ardekani
- Department of Biochemistry, Molecular Biology and Cell Biology, Northwestern University, Evanston, Illinois 60208, USA
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Grenett HE, Aikens ML, Torres JA, Demissie S, Tabengwa EM, Davis GC, Booyse FM. Ethanol Transcriptionally Upregulates t-PA and u-PA Gene Expression in Cultured Human Endothelial Cells. Alcohol Clin Exp Res 1998. [DOI: 10.1111/j.1530-0277.1998.tb03878.x] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Muth TR, Gottardi CJ, Roush DL, Caplan MJ. A basolateral sorting signal is encoded in the alpha-subunit of Na-K-ATPase. THE AMERICAN JOURNAL OF PHYSIOLOGY 1998; 274:C688-96. [PMID: 9530100 DOI: 10.1152/ajpcell.1998.274.3.c688] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Na-K-ATPase and H-K-ATPase are highly homologous ion pumps that exhibit distinct plasma membrane distributions in epithelial cells. We have studied the alpha-subunits of these heterodimeric pumps to identify the protein domains responsible for their polarized sorting. A chimeric alpha-subunit construct (N519H) was generated in which the first 519 amino acid residues correspond to the Na-K-ATPase sequence and the remaining 500 amino acids are derived from the H-K-ATPase sequence. In stably transfected LLC-PK1 cell lines, we found that the N519H chimera is restricted to the basolateral surface under steady-state conditions, suggesting that residues within the NH2-terminal 519 amino acids of the Na-K-ATPase alpha-subunit contain a basolateral sorting signal. H-K-ATPase beta-subunit expressed alone in LLC-PK1 cells accumulates at the apical surface. When coexpressed with N519H, the H-K-ATPase beta-subunit assembles with this chimera and accompanies it to the basolateral surface. Thus the NH2-terminal basolateral signal in the Na-K-ATPase alpha-subunit masks or is dominant over any apical sorting information present in the beta-polypeptide. In gastric parietal cells, the H-K-ATPase beta-subunit targets the H-K-ATPase to an intracellular vesicular compartment which fuses with the plasma membrane in response to secretagogue stimulation. To test whether the chimera-H-K-ATPase beta-subunit complex is directed to a similar compartment in LLC-PK1 cells, we treated transfected cells with drugs that raise intracellular adenosine 3',5'-cyclic monophosphate (cAMP) levels. Elevation of cytosolic cAMP increased the surface expression of both the N519H chimera and the H-K-ATPase beta-subunit. This increase in surface expression, however, appears to be the result of transcriptional upregulation and not recruitment of chimera to the surface from a cAMP-inducible compartment.
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Affiliation(s)
- T R Muth
- Department of Cell Biology, Yale University School of Medicine, New Haven, Connecticut 06510, USA
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Sumpio BE, Chang R, Xu WJ, Wang XJ, Du W. Regulation of tPA in endothelial cells exposed to cyclic strain: role of CRE, AP-2, and SSRE binding sites. THE AMERICAN JOURNAL OF PHYSIOLOGY 1997; 273:C1441-8. [PMID: 9374627 DOI: 10.1152/ajpcell.1997.273.5.c1441] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
We have previously reported that exposure of cultured bovine aortic endothelial cells (EC) to 10% average strain resulted in an increase in tissue plasminogen activator (tPA) mRNA, immunoreactive tPA protein, and tPA activity in the medium. The present study was designed to examine the regulation of tPA gene expression in EC by cyclic strain. We performed a functional analysis of the tPA promoter by transfecting bovine aortic EC with a 1.4-kilobase (kb) construct of the human tPA promoter coupled to chloramphenicol acetyltransferase. We found that subjecting the EC to 10% average strain (and not 6% average strain) resulted in a 2.6-fold increase in activity of the 1.4-kb tPA promoter by 4 h. Analysis of deletion mutants of the promoter transfected into EC demonstrated a 60% drop-off in activity between position -145 and -105. Deoxyribonuclease I protection analysis of the segment downstream of position -196 suggested involvement of activator protein-2 (AP-2) and adenosine 3',5'-cyclic monophosphate-responsive element (CRE)-like binding sites, which was confirmed by electrophoretic mobility shift assays. Site-directed mutants of either the AP-2 or CRE-like regions resulted in a 65% decrease in activity compared with the wild type. Double mutations abolished basal transcription and any strain-induced activity. A shear stress responsive element (SSRE) binding site is present at -945, but site-directed mutants did not show any drop in activity compared with wild type by cyclic strain. These studies demonstrate that cyclic strain regulates tPA gene transcription in bovine aortic EC and that this transcriptional activation is dependent on factors that are similar to those activated with phorbol ester.
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Affiliation(s)
- B E Sumpio
- Department of Surgery (Vascular), Yale University School of Medicine, New Haven, Connecticut 06510, USA
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Leonardsson G, Ny T. Characterisation of the rat tissue-type plasminogen activator gene promoter -- identification of a TAAT-containing promoter element. EUROPEAN JOURNAL OF BIOCHEMISTRY 1997; 248:676-83. [PMID: 9342217 DOI: 10.1111/j.1432-1033.1997.t01-1-00676.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Tissue-type plasminogen activator (tPA) activates plasminogen to the active protease plasmin and is implicated in many biological processes that require extracellular proteolysis. In rat ovarian cells, gonadotropins induce the tPA gene by a cAMP-dependent pathway and this induction correlates with the time of follicular rupture. We have previously identified several promoter elements within the first 621 bp of the rat tPA promoter that are important for constitutive and cAMP-induced expression of the gene, including a cAMP responsive element (CRE), a nuclear factor 1 (NF1) element, a SP1-binding site and a G+C-rich box. In this report we have extended our study by analysing promoter constructs, ranging in size from 7.7 kb to 135 bp fused to the luciferase reporter gene. Transient transfection analysis of rat granulosa cells and human 293 cells, reveal that the proximal 268 bp of the promoter is enough to confer high basal and cAMP-induced expression of the gene. At position -162 to -172, between the previously identified CRE and NF1 sites, a novel TAAT-containing promoter element was identified. Mutational inactivation of the TAAT motif indicates that this element is important for both constitutive and cAMP-induced expression of the gene, and for the binding of a presumably novel nuclear factor that we have termed tPA promoter factor-1 (tPF-1).
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Affiliation(s)
- G Leonardsson
- Department of Medical Biochemistry and Biophysics, Umeå University, Sweden
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Okladnova O, Poleev A, Fantes J, Lee M, Plachov D, Horst J. The genomic organization of the murine Pax 8 gene and characterization of its basal promoter. Genomics 1997; 42:452-61. [PMID: 9205117 DOI: 10.1006/geno.1997.4735] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Lambda phage clones containing the murine Pax 8 gene were isolated from a C57BL/6 kidney genomic mouse library using mouse cDNA fragments as probes. A clone encompassing about 16 kb of the 5' untranslated region of the murine Pax 8 gene was isolated from a mouse embryonic stem cell (D3) library. The murine Pax 8 gene has a size of approximately 26 kb and contains the coding sequence for mRNA in 12 exons. The major and several minor transcription initiation sites were identified. Position +1 is located 488 nucleotides upstream of the ATG initiation codon and 24 bases downstream of a TATA-like sequence, ATAAAA. The translation initiation and termination sites are located in exons 2 and 12, respectively. Further analysis of 570 bases of the 5' flanking sequence revealed AP2, SP1, PEA3, zeste, NF-kappaB, and CCAAT consensus binding sites. Ribonuclease protection assays with a probe spanning the first two exons of mouse Pax 8 cDNA on total RNA samples isolated from different tissues of newborn mice show that the murine Pax 8 gene is predominantly expressed in kidney tissue. Low levels of Pax 8 gene expression were also found in the liver, spleen, lung, brain, and heart. The same transcription initiation sites are utilized in different tissues of newborn mice and embryo at Day 10.5 postconception. A FISH assay shows that the murine Pax 8 gene is located on chromosome 2, map position B.
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Affiliation(s)
- O Okladnova
- Institut für Humangenetik, Universität Munster, Germany
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