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Briand N, Guénantin AC, Jeziorowska D, Shah A, Mantecon M, Capel E, Garcia M, Oldenburg A, Paulsen J, Hulot JS, Vigouroux C, Collas P. The lipodystrophic hotspot lamin A p.R482W mutation deregulates the mesodermal inducer T/Brachyury and early vascular differentiation gene networks. Hum Mol Genet 2019; 27:1447-1459. [PMID: 29438482 DOI: 10.1093/hmg/ddy055] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2018] [Accepted: 02/08/2018] [Indexed: 12/21/2022] Open
Abstract
The p.R482W hotspot mutation in A-type nuclear lamins causes familial partial lipodystrophy of Dunnigan-type (FPLD2), a lipodystrophic syndrome complicated by early onset atherosclerosis. Molecular mechanisms underlying endothelial cell dysfunction conferred by the lamin A mutation remain elusive. However, lamin A regulates epigenetic developmental pathways and mutations could perturb these functions. Here, we demonstrate that lamin A R482W elicits endothelial differentiation defects in a developmental model of FPLD2. Genome modeling in fibroblasts from patients with FPLD2 caused by the lamin A R482W mutation reveals repositioning of the mesodermal regulator T/Brachyury locus towards the nuclear center relative to normal fibroblasts, suggesting enhanced activation propensity of the locus in a developmental model of FPLD2. Addressing this issue, we report phenotypic and transcriptional alterations in mesodermal and endothelial differentiation of induced pluripotent stem cells we generated from a patient with R482W-associated FPLD2. Correction of the LMNA mutation ameliorates R482W-associated phenotypes and gene expression. Transcriptomics links endothelial differentiation defects to decreased Polycomb-mediated repression of the T/Brachyury locus and over-activation of T target genes. Binding of the Polycomb repressor complex 2 to T/Brachyury is impaired by the mutated lamin A network, which is unable to properly associate with the locus. This leads to a deregulation of vascular gene expression over time. By connecting a lipodystrophic hotspot lamin A mutation to a disruption of early mesodermal gene expression and defective endothelial differentiation, we propose that the mutation rewires the fate of several lineages, resulting in multi-tissue pathogenic phenotypes.
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Affiliation(s)
- Nolwenn Briand
- Department of Molecular Medicine, Institute of Basic Medical Sciences, Faculty of Medicine, University of Oslo, 0317 Oslo, Norway.,Sorbonne Université, Inserm UMR S938, Saint-Antoine Research Centre, Institute of Cardiometabolism and Nutrition, 75012 Paris, France
| | - Anne-Claire Guénantin
- Sorbonne Université, Inserm UMR S938, Saint-Antoine Research Centre, Institute of Cardiometabolism and Nutrition, 75012 Paris, France.,Wellcome Trust Sanger Institute, Hinxton, Cambridge CB10 1SA, UK
| | - Dorota Jeziorowska
- Sorbonne Université, UPMC Université Paris 6, UMR-S1166 ICAN, 75013 Paris, France
| | - Akshay Shah
- Department of Molecular Medicine, Institute of Basic Medical Sciences, Faculty of Medicine, University of Oslo, 0317 Oslo, Norway
| | - Matthieu Mantecon
- Sorbonne Université, Inserm UMR S938, Saint-Antoine Research Centre, Institute of Cardiometabolism and Nutrition, 75012 Paris, France
| | - Emilie Capel
- Sorbonne Université, Inserm UMR S938, Saint-Antoine Research Centre, Institute of Cardiometabolism and Nutrition, 75012 Paris, France
| | - Marie Garcia
- Sorbonne Université, Inserm UMR S938, Saint-Antoine Research Centre, Institute of Cardiometabolism and Nutrition, 75012 Paris, France
| | - Anja Oldenburg
- Department of Molecular Medicine, Institute of Basic Medical Sciences, Faculty of Medicine, University of Oslo, 0317 Oslo, Norway
| | - Jonas Paulsen
- Department of Molecular Medicine, Institute of Basic Medical Sciences, Faculty of Medicine, University of Oslo, 0317 Oslo, Norway
| | - Jean-Sebastien Hulot
- Sorbonne Université, UPMC Université Paris 6, UMR-S1166 ICAN, 75013 Paris, France
| | - Corinne Vigouroux
- Sorbonne Université, Inserm UMR S938, Saint-Antoine Research Centre, Institute of Cardiometabolism and Nutrition, 75012 Paris, France.,AP-HP Saint-Antoine Hospital, Molecular Biology and Genetics Laboratory, Endocrinology Department, National Reference Center for Insulin Secretion and Insulin Sensitivity Rare Diseases, 75012 Paris, France
| | - Philippe Collas
- Department of Molecular Medicine, Institute of Basic Medical Sciences, Faculty of Medicine, University of Oslo, 0317 Oslo, Norway.,Department of Immunology and Transfusion Medicine, Norwegian Center for Stem Cell Research, Oslo University Hospital, 0424 Oslo, Norway
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Oldenburg A, Briand N, Sørensen AL, Cahyani I, Shah A, Moskaug JØ, Collas P. A lipodystrophy-causing lamin A mutant alters conformation and epigenetic regulation of the anti-adipogenic MIR335 locus. J Cell Biol 2017; 216:2731-2743. [PMID: 28751304 PMCID: PMC5584164 DOI: 10.1083/jcb.201701043] [Citation(s) in RCA: 59] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2017] [Revised: 05/04/2017] [Accepted: 06/20/2017] [Indexed: 12/30/2022] Open
Abstract
Mutations in the Lamin A/C (LMNA) gene-encoding nuclear LMNA cause laminopathies, which include partial lipodystrophies associated with metabolic syndromes. The lipodystrophy-associated LMNA p.R482W mutation is known to impair adipogenic differentiation, but the mechanisms involved are unclear. We show in this study that the lamin A p.R482W hot spot mutation prevents adipogenic gene expression by epigenetically deregulating long-range enhancers of the anti-adipogenic MIR335 microRNA gene in human adipocyte progenitor cells. The R482W mutation results in a loss of function of differentiation-dependent lamin A binding to the MIR335 locus. This impairs H3K27 methylation and instead favors H3K27 acetylation on MIR335 enhancers. The lamin A mutation further promotes spatial clustering of MIR335 enhancer and promoter elements along with overexpression of the MIR355 gene after adipogenic induction. Our results link a laminopathy-causing lamin A mutation to an unsuspected deregulation of chromatin states and spatial conformation of an miRNA locus critical for adipose progenitor cell fate.
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Affiliation(s)
- Anja Oldenburg
- Department of Molecular Medicine, Institute of Basic Medical Sciences, Faculty of Medicine, University of Oslo, Oslo, Norway
| | - Nolwenn Briand
- Department of Molecular Medicine, Institute of Basic Medical Sciences, Faculty of Medicine, University of Oslo, Oslo, Norway
| | - Anita L Sørensen
- Department of Molecular Medicine, Institute of Basic Medical Sciences, Faculty of Medicine, University of Oslo, Oslo, Norway
| | - Inswasti Cahyani
- Department of Molecular Medicine, Institute of Basic Medical Sciences, Faculty of Medicine, University of Oslo, Oslo, Norway
| | - Akshay Shah
- Department of Molecular Medicine, Institute of Basic Medical Sciences, Faculty of Medicine, University of Oslo, Oslo, Norway
| | - Jan Øivind Moskaug
- Department of Molecular Medicine, Institute of Basic Medical Sciences, Faculty of Medicine, University of Oslo, Oslo, Norway.,Norwegian Center for Stem Cell Research, Department of Immunology, Oslo University Hospital, Oslo, Norway
| | - Philippe Collas
- Department of Molecular Medicine, Institute of Basic Medical Sciences, Faculty of Medicine, University of Oslo, Oslo, Norway .,Norwegian Center for Stem Cell Research, Department of Immunology, Oslo University Hospital, Oslo, Norway
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Lund EG, Duband-Goulet I, Oldenburg A, Buendia B, Collas P. Distinct features of lamin A-interacting chromatin domains mapped by ChIP-sequencing from sonicated or micrococcal nuclease-digested chromatin. Nucleus 2015; 6:30-9. [PMID: 25602132 DOI: 10.4161/19491034.2014.990855] [Citation(s) in RCA: 65] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
The nuclear lamina has been shown to interact with the genome through lamina-associated domains (LADs). LADs have been identified by DamID, a proximity labeling assay, and more recently by chromatin immunoprecipitation-sequencing (ChIP-seq) of A- and B-type lamins. LADs form megabase-size domains at the nuclear periphery, they are gene-poor and mostly heterochromatic. Here, we show that the mode of chromatin fragmentation for ChIP, namely bath sonication or digestion with micrococcal nuclease (MNase), leads to the discovery of common but also distinct sets of lamin-interacting domains, or LiDs. Using ChIP-seq, we show the existence of lamin A/C (LMNA) LiDs with distinct gene contents, histone composition enrichment and relationships to lamin B1-interacting domains. The extent of genome coverage of lamin A/C (LMNA) LiDs in sonicated or MNase-digested chromatin is similar (∼730 megabases); however over half of these domains are uniquely detected in sonicated or MNase-digested chromatin. Sonication-specific LMNA LiDs are gene-poor and devoid of a broad panel of histone modifications, while MNase-specific LMNA LiDs are of higher gene density and are enriched in H3K9me3, H3K27me3 and in histone variant H2A.Z. LMNB1 LiDs are gene-poor and show no or little enrichment in these marks. Comparison of published LMNB1 DamID LADs with LMNB1 and LMNA LiDs identified here by ChIP-seq further shows that LMNA can associate with 'open' chromatin domains displaying euchromatin characteristics, and which are not associated with LMNB1. The differential genomic and epigenetic properties of lamin-interacting domains reflect the existence of distinct LiD populations identifiable in different chromatin contexts, including nuclease-accessible regions presumably localized in the nuclear interior.
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Affiliation(s)
- Eivind G Lund
- a Department of Molecular Medicine, Institute of Basic Medical Sciences ; University of Oslo, and Norwegian Center for Stem Cell Research , Oslo , Norway
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Shah A, Oldenburg A, Collas P. A hyper-dynamic nature of bivalent promoter states underlies coordinated developmental gene expression modules. BMC Genomics 2014; 15:1186. [PMID: 25551786 PMCID: PMC4320513 DOI: 10.1186/1471-2164-15-1186] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2014] [Accepted: 12/15/2014] [Indexed: 02/07/2023] Open
Abstract
Background Chromatin remodeling is crucial for proper programing of developmental gene expression. Recent work provides a dynamic view of post-translational histone modifications during differentiation; however there is little insight on the evolution of combinatorial genome-wide patterns of chromatin marks, excluding an essential aspect of developmental gene regulation. Results We report here a 15-chromatin state Hidden Markov Model which describes changes in chromatin signatures in relation to transcription profiles during differentiation of human pre-adipocytes into adipocytes. We identify nineteen modules of gene expression reflecting multiple waves of transcriptional up- and down-regulation which characterize adipogenic differentiation. From our model, we developed chromatin state matrices fitting each of these transcription modules to show how the complexity and dynamic nature of chromatin signatures relate to expression patterns. Spatial relationships between chromatin states underlie a high-order chromatin organization in differentiating adipocytes. We show the importance of gene expression level in generating diversity in chromatin signatures, and show that the hyper-dynamic nature of H3K4me2/H3K27me3-marked ‘bivalent’ promoter states underlies many of the gene expression patterns associated with adipogenic differentiation. Conclusions Our results reveal the highly dynamic nature of bivalent promoter states within the adipogenic lineage. The data constitute a valuable resource enabling the assessment of possibilities to alter the adipogenic program. Electronic supplementary material The online version of this article (doi:10.1186/1471-2164-15-1186) contains supplementary material, which is available to authorized users.
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Affiliation(s)
| | | | - Philippe Collas
- Department of Molecular Medicine, Institute of Basic Medical Sciences, Faculty of Medicine, University of Oslo, 0317 Oslo, Norway.
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Johansen ML, Oldenburg A, Rosthøj S, Cohn Maxild J, Rode L, Tabor A. Crown-rump length discordance in the first trimester: a predictor of adverse outcome in twin pregnancies? Ultrasound Obstet Gynecol 2014; 43:277-283. [PMID: 23754823 DOI: 10.1002/uog.12534] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/04/2013] [Revised: 05/23/2013] [Accepted: 05/29/2013] [Indexed: 06/02/2023]
Abstract
OBJECTIVES To evaluate the usefulness of first-trimester crown-rump length (CRL) discordance in predicting adverse outcome in twin pregnancies. METHODS This retrospective study included a large cohort retrieved from local ultrasound databases at 14 obstetric departments in Denmark, comprising all twin pregnancies with two live fetuses scanned between 11 and 14 weeks' gestation during the period 1 January 2004 to 31 December 2006. The association between CRL discordance ≥ 10 % and adverse outcome was evaluated. RESULTS Among 1993 twin pregnancies, 1733 were dichorionic (156 (9%) discordant; 1577 (91%) concordant) and 260 were monochorionic (32 (12%) discordant; 228 (88%) concordant). In dichorionic twin pregnancies we found an association between CRL discordance ≥ 10% and preterm delivery before 34 weeks' gestation (P=0.007), birth weight discordance (P=0.001) and mean birth weight (P=0.033). In monochorionic twin pregnancies we found an association between CRL discordance ≥ 10% and birth weight discordance (P=0.02) and mean birth weight (P=0.03). To evaluate CRL discordance as a predictor of fetal loss and preterm delivery before 34 weeks' gestation, receiver-operating characteristics curves were created for each outcome. For CRL discordance ≥ 10% as a predictor of fetal loss and preterm delivery in dichorionic twin pregnancies, sensitivity was 0.17 (95% CI, 0.06-0.28) and 0.14 (95% CI, 0.10-0.18), respectively, and in monochorionic twin pregnancies it was 0.10 (95% CI, 0.03-0.22) and 0.16 (95% CI, 0.06-0.26), respectively. CONCLUSIONS CRL discordance in twin pregnancies is associated with, but is not a strong predictor of, adverse outcome.
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Affiliation(s)
- M L Johansen
- Center for Fetal Medicine, Department of Obstetrics and Gynecology, Rigshospitalet, Copenhagen University Hospital, Copenhagen, Denmark
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Oldenburg A, Rode L, Bødker B, Ersbak V, Holmskov A, Jørgensen FS, Larsen H, Larsen T, Laursen L, Mogensen H, Petersen OB, Rasmussen S, Skibsted L, Sperling L, Stornes I, Zingenberg H, Tabor A. Influence of chorionicity on perinatal outcome in a large cohort of Danish twin pregnancies. Ultrasound Obstet Gynecol 2012; 39:69-74. [PMID: 21830245 DOI: 10.1002/uog.10057] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 07/13/2011] [Indexed: 05/31/2023]
Abstract
OBJECTIVE To assess outcome in twin pregnancies according to chorionicity. METHODS A cohort was retrieved from local ultrasound databases at 14 obstetric departments in Denmark, comprising all twin pregnancies with two live fetuses scanned between weeks 11 and 14 in the period 1 January 2004 to 31 December 2006. Outcome data were retrieved from the National Board of Health. RESULTS Among 2038 twin pregnancies, 1757 (86.2%) were dichorionic (DC) and 281 (13.8%) were monochorionic diamniotic (MC). In MC pregnancies, the rate of spontaneous fetal loss in both second and third trimesters was more than threefold higher than the comparable rate in DC pregnancies: 6.0% vs. 1.9% for at least one fetus in the second trimester (P < 0.001) and 2.1% vs. 0.7% in the third trimester (P = 0.03). In 98.4% of DC pregnancies and in 91.1% of MC pregnancies, at least one infant was liveborn. Amongst pregnancies with two live fetuses at 24 weeks, the proportion with two live infants at 28 days after delivery was 97.5% and 95.1%, respectively. CONCLUSIONS The increased incidence of fetal loss in MC pregnancies compared with DC pregnancies predominantly occurs before 24 weeks' gestation. After this stage, although the risk of intrauterine fetal death is still higher in MC than in DC pregnancies, if both fetuses are alive at 24 weeks, the chance of a woman having two live infants 1 month after delivery is similar in MC and DC pregnancies.
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Affiliation(s)
- A Oldenburg
- Department of Fetal Medicine, Copenhagen University Hospital, Copenhagen, Denmark.
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Hohmann J, Müller C, Oldenburg A, Skrok J, Frericks BB, Wolf KJ, Albrecht T. Hepatic transit time analysis using contrast-enhanced ultrasound with BR1: A prospective study comparing patients with liver metastases from colorectal cancer with healthy volunteers. Ultrasound Med Biol 2009; 35:1427-1435. [PMID: 19540656 DOI: 10.1016/j.ultrasmedbio.2009.04.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/11/2008] [Revised: 03/24/2009] [Accepted: 04/08/2009] [Indexed: 05/27/2023]
Abstract
We prospectively compared hepatic transit time (HTT) measurements in subjects with liver metastases from colorectal cancer (group a) and healthy volunteers (group b) using contrast-enhanced ultrasound with BR1. The purpose of this study was to verify our hypothesis that the hemodynamic changes of the liver, which occur during metastasis seeding, would shorten the HTT, and we expect that such changes could be used for the detection of occult liver metastases from colorectal cancer in the future. The study had institutional review board approval and all subjects gave informed written consent. Group a and group b consisted of 22 subjects each. Baseline and post contrast images were acquired starting 10 s before and ending 40 s after administration of BR1, using nonlinear imaging at a frame rate of 5/s. The baseline images were used to determine the signal intensity without contrast enhancement as the reference signal. Arrival times (AT) of the contrast agent for the hepatic artery, the portal vein and one hepatic vein were determined using (i) quantitative analysis and (ii) subjective analysis by two blinded readers. HTT was calculated based on arrival time measurements. Quantitative and subjective analysis showed significantly shorter arterial to venous and portal to venous HTT in group a compared with group b (p < 0.001). Arterial to venous HTT (quantitative analysis) was < or = 9 s in 19 of 22 subjects of group a and >9 s in 18 of 22 subjects of group b (sensitivity 86%, specificity 82%, positive predictive value 83%, negative predictive value 86%, area under the curve [AUC] 0.87). Portal to venous HTT (quantitative analysis) was < 7 s in 21 of 22 subjects of group a and > 7s in 15 of 22 subjects of group b (sensitivity 95%, specificity 68%, PPV 75%, NPV 94%, AUC 0.85). There was an inverse relation with number of liver segments involved for arterial to venous and portal to venous HTT in group a (p < 0.05), but no correlation between HTT and overall volume of metastases (group a) or subject age (group b). From the results of our study, we conclude that HTT measurements using contrast-enhanced ultrasound with BR1 can detect hemodynamic changes caused by metastatic liver disease from colorectal cancer. However, comparison with the literature suggests that the use of other contrast agents might provide better results. Comparison of different contrast agents for the purpose of transit time analysis would therefore be useful before embarking on a prospective trial looking at the detection of occult liver metastases in patients with colorectal cancer. (E-mail: jhohmann@uhbs.ch).
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Affiliation(s)
- Joachim Hohmann
- Department of Radiology, University Hospital Basel, Switzerland.
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Hohmann J, Müller C, Oldenburg A, Skrok J, Wolf KJ, Albrecht T. Hepatische Transitzeitanalyse mit MRT: Ein Vergleich von Patienten mit Lebermetastasen colorektaler Karzinome und lebergesunden Probanden. ROFO-FORTSCHR RONTG 2009. [DOI: 10.1055/s-0029-1221406] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Abstract
In patients with known malignancy, correct detection and characterization of liver lesions has important therapeutic consequences. Conventional sonography is the most commonly used modality for liver imaging in tumor patients. However, it has a lower sensitivity for the detection of liver metastases compared to contrast-enhanced computed tomography (CT) and magnetic resonance imaging (MRI). The majority of liver metastases are hypoechoic and well defined in baseline ultrasound (US), while detection of isoechoic or small liver metastases <1 cm is difficult and the differentiation of liver metastases from benign liver lesions and other malignant liver tumors can be impossible with baseline US. The use of microbubble-based ultrasound contrast agents and contrast-specific imaging techniques advanced the accuracy of ultrasound in liver imaging. Levovist and SonoVue are the US contrast agents approved for liver imaging in Europe. Compared to Levovist, SonoVue allows continuous imaging of the liver in real-time over a period of up to 5 minutes. As a result, SonoVue became the preferred contrast agent for liver imaging in the recent years, while Levovist became less important. Important for the detection of liver metastases are the portal venous and late phases in which metastases show a wash-out and can be detected as hypoechoic lesions in homogeneous enhanced liver parenchyma. The detection of hepatic metastases is substantially improved by CEUS compared to conventional B-mode sonography. Several studies showed sensitivity in detecting liver metastases comparable to that of contrast-enhanced CT and MRI. Furthermore, the typical enhancement patterns of the different benign and malignant liver lesions allow reliable characterization and differentiation from liver metastases in the majority of cases. This paper provides information about the advantages and expedient application of contrast-enhanced ultrasound (CEUS) in tumor patients.
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Affiliation(s)
- A Oldenburg
- Klinik und Hochschulambulanz für Radiologie und Nuklearmedizin, Charite, Campus Benjamin Franklin, Berlin.
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Tepe G, Zeller T, Albrecht T, Heller S, Schwarzwälder U, Beregi JP, Claussen CD, Oldenburg A, Scheller B, Speck U. Local delivery of paclitaxel to inhibit restenosis during angioplasty of the leg. N Engl J Med 2008; 358:689-99. [PMID: 18272892 DOI: 10.1056/nejmoa0706356] [Citation(s) in RCA: 588] [Impact Index Per Article: 36.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
BACKGROUND Drug-eluting stents reduce restenosis in coronary arteries, but clinical trials have failed to prove their efficacy in peripheral arteries. We investigated the use of paclitaxel-coated angioplasty balloons and paclitaxel dissolved in the angiographic contrast medium during angioplasty of the leg. METHODS In a small, multicenter trial, we randomly assigned 154 patients with stenosis or occlusion of a femoropopliteal artery to treatment with standard balloon catheters coated with paclitaxel, uncoated balloons with paclitaxel dissolved in the contrast medium, or uncoated balloons without paclitaxel (control). The primary end point was late lumen loss at 6 months. RESULTS The mean (+/-SD) age of the patients was 68+/-8 years, 24% were smokers, and 49% had diabetes. Twenty-seven percent of the lesions were total occlusions, and 36% were restenotic lesions. The mean lesion length was 7.4+/-6.5 cm. There were no significant differences in baseline characteristics between the groups. There were no adverse events attributable to the paclitaxel-coated balloons. At 6 months, the mean late lumen loss was 1.7+/-1.8 mm in the control group, as compared with 0.4+/-1.2 mm (P<0.001) in the group treated with paclitaxel-coated balloons and 2.2+/-1.6 mm (P=0.11) in the group treated with paclitaxel in the contrast medium. The rate of revascularization of target lesions at 6 months was 20 of 54 (37%) in the control group, 2 of 48 (4%) in the group treated with paclitaxel-coated balloons (P<0.001 vs. control), and 15 of 52 (29%) in the group treated with paclitaxel in the contrast medium (P=0.41 vs. control); at 24 months, the rates increased to 28 of 54 (52%), 7 of 48 (15%), and 21 of 52 (40%), respectively. CONCLUSIONS Use of paclitaxel-coated angioplasty balloons during percutaneous treatment of femoropopliteal disease is associated with significant reductions in late lumen loss and target-lesion revascularization. No significant benefit is seen with the use of a paclitaxel-containing contrast medium. (ClinicalTrials.gov number, NCT00156624 [ClinicalTrials.gov].).
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Affiliation(s)
- Gunnar Tepe
- Radiologische Klinik, Diagnostische und Interventionelle Radiologie, Eberhard-Karls-Universität, Tübingen, Germany.
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Leen E, Ceccotti P, Moug SJ, Glen P, MacQuarrie J, Angerson WJ, Albrecht T, Hohmann J, Oldenburg A, Ritz JP, Horgan PG. Potential value of contrast-enhanced intraoperative ultrasonography during partial hepatectomy for metastases: an essential investigation before resection? Ann Surg 2006; 243:236-40. [PMID: 16432357 PMCID: PMC1448920 DOI: 10.1097/01.sla.0000197708.77063.07] [Citation(s) in RCA: 149] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
OBJECTIVE The aim of the study was to assess the clinical value of contrast-enhanced intraoperative ultrasound (CE-IOUS) as a novel tool in the hepatic staging of patients undergoing liver resection. METHODS Sixty patients scheduled to undergo liver resection for metastatic disease were studied. Preoperative staging with contrast-enhanced CT and/or MR scans was performed within 2 to 6 weeks of operation. Following exploration, intraoperative ultrasound (IOUS) was performed using an HDI-5000 scanner (Philips) and a finger-probe with pulse inversion harmonic (PIH) capability. CE-IOUS in the PIH mode was performed in a standardized protocol (low MI: 0.02-0.04) after intravenous injection of 3-4 mL of SonoVue (Bracco spa, Milan); all detected lesions on precontrast and postcontrast scans were counted and mapped. Any alteration in surgical management was documented following CE-IOUS compared with IOUS. RESULTS Three patients were excluded due to disseminated disease on exploration. CE-IOUS was significantly more sensitive than CT/MR and IOUS in detecting liver metastases (96.1% versus 76.7% and 81.5%, respectively) (P<0.05); it altered surgical management in 29.8% (17 of 57) of cases, due to 1) additional metastases in 19.3% (11 of 57), 2) less metastases in 3.5% (2 of 57), 3) benign lesions wrongly diagnosed as metastasis on IOUS/CT in 5.3% (3 of 57), and 4) vascular proximity in 1.8% (1 of 57). Management was unchanged in 70.2% (40 of 57) despite additional lesions detected in 3.5% (2 of 57) and benign lesion wrongly diagnosed on IOUS and CT as metastasis in 1.8% (1 of 57). CE-IOUS altered combined IOUS/CT/MR staging in 35.1%. CONCLUSION These preliminary results suggest CE-IOUS is an essential tool prior to liver resection for metastases.
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Affiliation(s)
- Edward Leen
- Department of Surgery, Alexandra Parade, Royal Infirmary, Glasgow, UK.
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Albrecht T, Skrok J, Jenett M, Basilico R, Hohmann J, Oldenburg A, Wolf KJ. Charakterisierung fokaler Leberläsionen mit SonoVue – Vergleich von unverblindeter und verblindeter Bildauswertung. ROFO-FORTSCHR RONTG 2006. [DOI: 10.1055/s-2006-940885] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Oldenburg A, Hohmann J, Foert E, Skrok J, Hoffmann CW, Frericks B, Wolf KJ, Albrecht T. Detection of hepatic metastases with low MI real time contrast enhanced sonography and SonoVue. Ultraschall Med 2005; 26:277-84. [PMID: 16123921 DOI: 10.1055/s-2005-858526] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
AIM SonoVue is the first ultrasound contrast agent which allows repeated continuous examination of the liver in real time. The aim of this study was to compare low mechanical index (MI) real time contrast enhanced ultrasound of the liver, using the contrast agent SonoVue, with conventional B-mode sonography for the detection of hepatic metastases. METHOD 40 patients with known malignancy and at least one liver lesion on conventional B-mode sonography were included. Conventional B-mode sonography was performed followed by contrast enhanced ultrasound (CEUS) of the liver in the arterial (< 30 sec), portal-venous (40-120 sec) and delayed phase (> 120 sec) after injection of SonoVue. CEUS was performed using contrast specific imaging and low MI (< 0.3). Number, location and size of metastases on baseline and CEUS were compared with CT or MRI (blinded reader). RESULTS 37 patients had 128 metastases on CT or MRI. Baseline US showed 74 metastases confirmed by reference examination (69%), while CEUS yielded 109 metastases (sensitivity 90%) (p < 0.001). On CEUS, 35 additional metastases not seen on baseline but confirmed by reference imaging were detected in 14 patients (36%). In 8 patients, CEUS showed 13 metastases not seen on reference imaging. CONCLUSION Detection of hepatic metastases is substantially improved by low MI real time contrast enhanced ultrasound with SonoVue compared to conventional B-mode sonography.
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Affiliation(s)
- A Oldenburg
- Klinik und Poliklinik für Radiologie und Nuklearmedizin, Campus Benjamin Franklin, Charité-Universitätsmedizin Berlin.
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Albrecht T, Hohmann J, Oldenburg A. Fokale Leberläsionen: Sono. ROFO-FORTSCHR RONTG 2005. [DOI: 10.1055/s-2005-867302] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Oldenburg A, Albrecht T, Hohmann J, Skrok J, Wolf KJ. HCC-Detektion mittels KM-gestütztem Ultraschall mit SonoVue® in „low-MI-real-time-Technik“ im Vergleich zum konventionellen US. ROFO-FORTSCHR RONTG 2005. [DOI: 10.1055/s-2005-867701] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Abstract
Modern liver imaging of cancer patients requires an imaging modality that is not only highly sensitive in detecting lesions but also provides reliable characterisation of lesions and thus allows differentiation of metastases from frequently found benign lesions. Conventional ultrasound (US) has a relatively poor sensitivity and specificity for imaging liver metastases and US used to be inferior to CT and MRI mainly due to a lack of contrast agents. This has changed with the advent of microbubble contrast agents for US. The use of recent contrast agents such as SonoVue (Bracco, Italy) combined with low mechanical index contrast-specific imaging techniques such as Contrast Pulse Sequencing provides dynamic real time imaging of focal liver lesions in the arterial, portal venous and delayed phase. This improves lesion detection and characterisation. To investigate the benefit of SonoVue for detecting liver metastases we studied 40 cancer patients with liver lesions on reference imaging (CT or MRI), 37 of them had metastases. The mean number of reference confirmed metastases per patient increased from 1.85+/-1.79 on conventional ultrasound to 2.73+/-2.50 post SonoVue (p < 0.05). CEUS showed more individual metastases than baseline in 12 (34%) patients. Using CT or MRI as the reference, the mean sensitivity to individual metastases increased from 69% on baseline US to 90% post contrast (p < 0.0005). The role of SonoVue in characterisation of focal liver lesions was evaluated in 63 patients. One lesion was studied per patient. Based on standardised dynamic enhancement criteria for each lesion type, the number of correctly diagnosed lesions improved from 41 (65%) on baseline US to 58 (92%) post contrast (p < 0.001). On CEUS all 27 metastases were correctly diagnosed, while baseline US misinterpreted 2 of these. The number of correctly diagnosed benign lesions (n = 28) increased from 12 (43%) on baseline to 25 (89%) post SonoVue. In conclusion, detection and characterisation of focal liver lesions by US are markedly improved by the use of SonoVue. Contrast agents add a new dimension to sonography allowing it to rival CT and MRI, especially for lesion characterisation.
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Affiliation(s)
- T Albrecht
- Klinik und Poliklinik für Radiologie und Nuklearmedizin, Charité - Campus Benjamin Franklin, Universitätsmedizin Berlin, Freie Universität Berlin und Humboldt-Universität zu Berlin, Hindenburgdamm 30, 12200 Berlin, Germany.
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Kumar R, Musiyenko A, Oldenburg A, Adams B, Barik S. Post-translational generation of constitutively active cores from larger phosphatases in the malaria parasite, Plasmodium falciparum: implications for proteomics. BMC Mol Biol 2004; 5:6. [PMID: 15230980 PMCID: PMC459218 DOI: 10.1186/1471-2199-5-6] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2004] [Accepted: 07/01/2004] [Indexed: 11/16/2022] Open
Abstract
Background Although the complete genome sequences of a large number of organisms have been determined, the exact proteomes need to be characterized. More specifically, the extent to which post-translational processes such as proteolysis affect the synthesized proteins has remained unappreciated. We examined this issue in selected protein phosphatases of the protease-rich malaria parasite, Plasmodium falciparum. Results P. falciparum encodes a number of Ser/Thr protein phosphatases (PP) whose catalytic subunits are composed of a catalytic core and accessory domains essential for regulation of the catalytic activity. Two examples of such regulatory domains are found in the Ca+2-regulated phosphatases, PP7 and PP2B (calcineurin). The EF-hand domains of PP7 and the calmodulin-binding domain of PP2B are essential for stimulation of the phosphatase activity by Ca+2. We present biochemical evidence that P. falciparum generates these full-length phosphatases as well as their catalytic cores, most likely as intermediates of a proteolytic degradation pathway. While the full-length phosphatases are activated by Ca+2, the processed cores are constitutively active and either less responsive or unresponsive to Ca+2. The processing is extremely rapid, specific, and occurs in vivo. Conclusions Post-translational cleavage efficiently degrades complex full-length phosphatases in P. falciparum. In the course of such degradation, enzymatically active catalytic cores are produced as relatively stable intermediates. The universality of such proteolysis in other phosphatases or other multi-domain proteins and its potential impact on the overall proteome of a cell merits further investigation.
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Affiliation(s)
- Rajinder Kumar
- Department of Biochemistry and Molecular Biology, University of South Alabama, College of Medicine, 307 University Blvd., Mobile, Alabama, USA 36688-0002
| | - Alla Musiyenko
- Department of Biochemistry and Molecular Biology, University of South Alabama, College of Medicine, 307 University Blvd., Mobile, Alabama, USA 36688-0002
| | - Anja Oldenburg
- Department of Biochemistry and Molecular Biology, University of South Alabama, College of Medicine, 307 University Blvd., Mobile, Alabama, USA 36688-0002
| | - Brian Adams
- Department of Biochemistry and Molecular Biology, University of South Alabama, College of Medicine, 307 University Blvd., Mobile, Alabama, USA 36688-0002
| | - Sailen Barik
- Department of Biochemistry and Molecular Biology, University of South Alabama, College of Medicine, 307 University Blvd., Mobile, Alabama, USA 36688-0002
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Abstract
In patients with known or suspected malignancy, ultrasonography (US) is often the first choice for liver imaging because of its widespread availability and low cost. Compared with contrast-enhanced computed tomography (CT) and magnetic resonance imaging (MRI), the sensitivity of conventional US for detecting hepatic metastases is relatively poor. The advent of microbubble contrast agents changed this situation. Sensitivity and specificity increased substantially with the use of these contrast agents and contrast-specific imaging modes in recent years. Currently, numerous US imaging methods exist, based on Doppler techniques or harmonic imaging. They exploit the complex nonlinear behavior of microbubbles in a sound field to achieve marked augmentation of the US signal. Although microbubble contrast agents are essentially blood pool agents, some have a hepatosplenic specific late phase. Imaging during this late phase is particularly useful for improving the detection of malignant liver lesions and allows US to perform similarly to spiral CT as shown by recent studies. In addition, this late phase imaging is very helpful for lesion characterization. Low mechanical index imaging with the newer perfluor agents permits real-time imaging of the dynamic contrast behavior during the arterial, portal venous, and late phases and is particularly helpful for lesion characterization. The use of US for hemodynamic studies of the liver transit time may detect blood flow changes induced by micrometastases even before they become visible on imaging. In this field of functional imaging, further research is required to achieve conclusive results, which are not yet available.
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Affiliation(s)
- J Hohmann
- Klinik und Poliklinik für Radiologie und Nuklearmedizin, Campus Benjamin Franklin, Charité Universitätsmedizin Berlin, Freie Universität Berlin, Germany.
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Hohmann J, Albrecht T, Müller C, Oldenburg A, Wolf KJ. Transitzeitanalyse mit Kontrastmittel gestütztem Ultraschall (CEUS) und MRT: Vergleichende Untersuchung von Patienten mit Lebermetastasen und lebergesunden Probanden. ROFO-FORTSCHR RONTG 2004. [DOI: 10.1055/s-2004-827564] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Albrecht T, Oldenburg A, Hohmann J, Skrok J, Hoffmann CW, Schettler S, Wolf KJ. Imaging of liver metastases with contrast-specific low-MI real-time ultrasound and SonoVue. Eur Radiol 2004; 13 Suppl 3:N79-86. [PMID: 15015886 DOI: 10.1007/s00330-003-0012-2] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Affiliation(s)
- T Albrecht
- Klinik und Poliklinik für Radiologie und Nuklearmedizin, Charité-Campus Benjamin Franklin, Universitätsmedizin Berlin, Freie Universität Berlin und Humboldt-Universität zu Berlin, Germany
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Kumar R, Musiyenko A, Cioffi E, Oldenburg A, Adams B, Bitko V, Krishna SS, Barik S. A zinc-binding dual-specificity YVH1 phosphatase in the malaria parasite, Plasmodium falciparum, and its interaction with the nuclear protein, pescadillo. Mol Biochem Parasitol 2004; 133:297-310. [PMID: 14698441 DOI: 10.1016/j.molbiopara.2003.11.005] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Biochemical evidence revealed protein tyrosine kinase and phosphatase activities in the human malarial parasite Plasmodium falciparum, a member of the Apicomplexa. A novel cDNA sequence of a dual-specificity phosphatase was identified in both sexual and asexual stages of P. falciparum, and named PfYVH1, since the predicted primary structure of the 278-amino acid polypeptide showed significant similarity to the human and yeast YVH1 phosphatases. The N-terminal half of PfYVH1 contained a conserved tyrosine phosphatase catalytic domain within a dual-specificity phosphatase domain. The C-terminal region, consisting of one histidine and eight cysteines, represented a zinc-binding domain with a potentially unconventional architecture. Recombinant PfYVH1 contained 2mol of zinc per mol protein and dephosphorylated both phosphoserine and phosphotyrosine residues. Mutation of specific Cys residues in the putative zinc finger region abolished zinc binding and drastically reduced phosphatase activity, suggesting an allosteric role of zinc in catalysis. PfYVH1 was expressed in essentially all erythrocytic stages of the parasite, and shuttled between the nucleus and the cytoplasm in a stage-specific manner. A Plasmodium ortholog of the nuclear pescadillo protein (PfPES) was also characterized and shown to interact with PfYVH1, thus implicating PfYVH1 in the regulation of parasitic development. PfYVH1 represents the first dual-specificity zinc-finger phosphatase characterized in the protozoan kingdom.
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Affiliation(s)
- Rajinder Kumar
- Department of Biochemistry and Molecular Biology, College of Medicine, University of South Alabama, 307 University Boulevard, Mobile, AL 36688-0002, USA
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Oldenburg A, Hohmann J, Skrok J, Albrecht T. Imaging of paediatric splenic injury with contrast-enhanced ultrasonography. Pediatr Radiol 2004; 34:351-4. [PMID: 14652701 DOI: 10.1007/s00247-003-1092-5] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/13/2003] [Revised: 09/30/2003] [Accepted: 10/05/2003] [Indexed: 01/11/2023]
Abstract
We report two children who sustained traumatic parenchymal splenic injury and were monitored with contrast-enhanced ultrasound (CEUS). In both cases, unenhanced US failed to diagnose splenic haematoma, but the injury was well demonstrated after injection of contrast agent. In one case agreement with CT was excellent; in the other, CT was not performed due to the comprehensive information provided by CEUS.
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Affiliation(s)
- Anja Oldenburg
- Clinic and Polyclinic for Radiology and Nuclear Medicine, Charité Universitätsmedizin Berlin, Free University of Berlin and Humboldt University, Campus Benjamin Franklin, Hindenburgdamm 30, 12200 Berlin, Germany.
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Oldenburg A, Albrecht T, Hohmann J, Skrok J, Schettler S, Wolf KJ. Detektion von Lebermetastasen mittels Kontrastmittel gestützter Sonographie mit SonoVue in „low-MI-real-time“ Technik. ROFO-FORTSCHR RONTG 2004. [DOI: 10.1055/s-2004-827563] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Bitko V, Oldenburg A, Garmon NE, Barik S. Profilin is required for viral morphogenesis, syncytium formation, and cell-specific stress fiber induction by respiratory syncytial virus. BMC Microbiol 2003; 3:9. [PMID: 12740026 PMCID: PMC156654 DOI: 10.1186/1471-2180-3-9] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2003] [Accepted: 05/09/2003] [Indexed: 01/20/2023] Open
Abstract
BACKGROUND Actin is required for the gene expression and morphogenesis of respiratory syncytial virus (RSV), a clinically important Pneumovirus of the Paramyxoviridae family. In HEp-2 cells, RSV infection also induces actin stress fibers, which may be important in the immunopathology of the RSV disease. Profilin, a major regulator of actin polymerization, stimulates viral transcription in vitro. Thus, we tested the role of profilin in RSV growth and RSV-actin interactions in cultured cells (ex vivo). RESULTS We tested three cell lines: HEp-2 (human), A549 (human), and L2 (rat). In all three, RSV grew well and produced fused cells (syncytium), and two RSV proteins, namely, the phosphoprotein P and the nucleocapsid protein N, associated with profilin. In contrast, induction of actin stress fibers by RSV occurred in HEp-2 and L2 cells, but not in A549. Knockdown of profilin by RNA interference had a small effect on viral macromolecule synthesis but strongly inhibited maturation of progeny virions, cell fusion, and induction of stress fibers. CONCLUSIONS Profilin plays a cardinal role in RSV-mediated cell fusion and viral maturation. In contrast, interaction of profilin with the viral transcriptional proteins P and N may only nominally activate viral RNA-dependent RNA polymerase. Stress fiber formation is a cell-specific response to infection, requiring profilin and perhaps other signaling molecules that are absent in certain cell lines. Stress fibers per se play no role in RSV replication in cell culture. Clearly, the cellular architecture controls multiple steps of host-RSV interaction, some of which are regulated by profilin.
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Affiliation(s)
- Vira Bitko
- Department of Biochemistry and Molecular Biology, University of South Alabama, College of Medicine, 307 University Blvd., Mobile, Alabama, USA 36688-0002
| | - Anja Oldenburg
- Department of Biochemistry and Molecular Biology, University of South Alabama, College of Medicine, 307 University Blvd., Mobile, Alabama, USA 36688-0002
| | - Nicolle E Garmon
- Department of Biochemistry and Molecular Biology, University of South Alabama, College of Medicine, 307 University Blvd., Mobile, Alabama, USA 36688-0002
| | - Sailen Barik
- Department of Biochemistry and Molecular Biology, University of South Alabama, College of Medicine, 307 University Blvd., Mobile, Alabama, USA 36688-0002
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25
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Heidenreich JO, Oldenburg A, Pietilä T. [A rare manifestation of schwannoma in the main nasal cavity]. ROFO-FORTSCHR RONTG 2002; 174:1579-81. [PMID: 12471534 DOI: 10.1055/s-2002-35933] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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26
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Kumar R, Adams B, Oldenburg A, Musiyenko A, Barik S. Characterisation and expression of a PP1 serine/threonine protein phosphatase (PfPP1) from the malaria parasite, Plasmodium falciparum: demonstration of its essential role using RNA interference. Malar J 2002; 1:5. [PMID: 12057017 PMCID: PMC111503 DOI: 10.1186/1475-2875-1-5] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2002] [Accepted: 04/26/2002] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Reversible protein phosphorylation is relatively unexplored in the intracellular protozoa of the Apicomplexa family that includes the genus Plasmodium, to which belong the causative agents of malaria. Members of the PP1 family represent the most highly conserved protein phosphatase sequences in phylogeny and play essential regulatory roles in various cellular pathways. Previous evidence suggested a PP1-like activity in Plasmodium falciparum, not yet identified at the molecular level. RESULTS We have identified a PP1 catalytic subunit from P. falciparum and named it PfPP1. The predicted primary structure of the 304-amino acid long protein was highly similar to PP1 sequences of other species, and showed conservation of all the signature motifs. The purified recombinant protein exhibited potent phosphatase activity in vitro. Its sensitivity to specific phosphatase inhibitors was characteristic of the PP1 class. The authenticity of the PfPP1 cDNA was further confirmed by mutational analysis of strategic amino acid residues important in catalysis. The protein was expressed in all erythrocytic stages of the parasite. Abrogation of PP1 expression by synthetic short interfering RNA (siRNA) led to inhibition of parasite DNA synthesis. CONCLUSIONS The high sequence similarity of PfPP1 with other PP1 members suggests conservation of function. Phenotypic gene knockdown studies using siRNA confirmed its essential role in the parasite. Detailed studies of PfPP1 and its regulation may unravel the role of reversible protein phosphorylation in the signalling pathways of the parasite, including glucose metabolism and parasitic cell division. The use of siRNA could be an important tool in the functional analysis of Apicomplexan genes.
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Affiliation(s)
- Rajinder Kumar
- Department of Biochemistry and Molecular Biology (MSB 2370), University of South Alabama, College of Medicine, 307 University Blvd., Mobile, AL 36688-0002, U.S.A
| | - Brian Adams
- Department of Biochemistry and Molecular Biology (MSB 2370), University of South Alabama, College of Medicine, 307 University Blvd., Mobile, AL 36688-0002, U.S.A
| | - Anja Oldenburg
- Department of Biochemistry and Molecular Biology (MSB 2370), University of South Alabama, College of Medicine, 307 University Blvd., Mobile, AL 36688-0002, U.S.A
| | - Alla Musiyenko
- Department of Biochemistry and Molecular Biology (MSB 2370), University of South Alabama, College of Medicine, 307 University Blvd., Mobile, AL 36688-0002, U.S.A
| | - Sailen Barik
- Department of Biochemistry and Molecular Biology (MSB 2370), University of South Alabama, College of Medicine, 307 University Blvd., Mobile, AL 36688-0002, U.S.A
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27
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Stuschke M, Stahl M, Wilke H, Walz M, Oldenburg A, Stüben G, Seeber S, Sack H. Induction chemotherapy followed by concurrent chemotherapy and high-dose radiotherapy for locally advanced squamous cell carcinoma of the upper-thoracic and midthoracic esophagus. Am J Clin Oncol 2000; 23:233-8. [PMID: 10857883 DOI: 10.1097/00000421-200006000-00004] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
The purpose of this study was to evaluate the efficacy and toxicity of an induction chemotherapy schedule followed by high-dose radiotherapy and concurrent chemotherapy for locally advanced squamous cell carcinomas of the upper and midthoracic esophagus. Patients were treated with three courses of fluorouracil, leucovorin, etoposide, and cisplatin-containing induction chemotherapy followed by high-dose external beam radiotherapy to 65 Gy in 6 weeks for T4 and obstructing T3 tumors. Transversable T3 tumors received 60 Gy in 6 weeks by external radiotherapy, followed by two high-dose-rate esophageal brachytherapy fractions of 4 Gy in 5-mm tissue depth. Concurrent to radiotherapy, cisplatin and etoposide were given. Long-term survival of 22 patients was 41% and 31% at 2 and 3 years, respectively, with a median follow-up of 39 months. The probability of locoregional tumor recurrence was 60% at 3 years for all patients and 30% for those with a partial or complete response to induction chemotherapy. Acute toxicity of this schedule was moderate. Long-term survivors had a good swallowing function. This schedule offers a considerable chance of long-term survival for patients with locally advanced squamous cell carcinomas of the upper and midthoracic esophagus. Local in-field recurrences are the main risk after definitive radiochemotherapy. Dose escalation of radiotherapy is possible because of the observed low late toxicity.
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Affiliation(s)
- M Stuschke
- Department of Radiotherapy, University of Essen, Germany
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28
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Ludwig R, Kretschmer M, Caspar G, Bojunga J, Oldenburg A, Schumm-Draeger P, Stegmüller M, von Minckwitz G, Usadel KH, Kusterer K. In vivo microscopy of murine islets of Langerhans: increased adhesion of transferred lymphocytes to islets depends on macrophage-derived cytokines in a model of organ-specific insulitis. Immunology 1999; 98:111-5. [PMID: 10469241 PMCID: PMC2326899 DOI: 10.1046/j.1365-2567.1999.00826.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Environmental factors contribute to the pathogenesis of type 1 diabetes (insulin-dependent diabetes mellitus). Multiple low doses of streptozotocin (MLDS) induce hyperglycaemia and insulitis in mice. Previously we demonstrated that adhesion of lymphocytes to endothelium of islets is only increased when donor animals were diabetic and recipient mice had received 5 mg/kg streptozotocin (STZ). Therefore we used streptozotocin to evaluate the immunological relevance of such an irritation of islets. Lymphocytes, separated from diabetic mice (MLDS), were fluorescently labelled and injected to recipient mice that had received 5 mg/kg STZ. With in vivo microscopy we measured lymphocyte flow and adherence in islets. Expression of vascular cell adhesion molecule-1 (VCAM-1) and intracellular adhesion molecule-1 (ICAM-1) in the pancreas was assessed using immunohistochemistry. Very late antigen-4 (VLA-4) and leucocyte function-associated antigen-1 (LFA-1) expression on transferred lymphocytes was measured with flow cytometry. Pretreatment of recipients with antibodies to cytokines or silica reduced lymphocyte adherence to islet endothelium from 2.04% (goat immunoglobulin G; IgG) or 1.82% (rat IgG) to 0.47, 0.58, 0.39 or 0. 19% for monoclonal antibody (mAb) interferon-gamma (IFN-gamma), polyclonal antibody (pAb) tumour necrosis factor-alpha (TNF-alpha), pAb interleukin (IL)-1alpha or silica, respectively. Reduced adhesion was associated with a decreased expression of VCAM-1 and ICAM-1 in islets of treated recipients compared with mice treated with 5 mg/kg STZ alone. In conclusion, pretreatment of recipients with 5 mg/kg STZ leads to an increased expression of adhesion molecules in the islets and lymphocyte adhesion to islet endothelium in vivo, demonstrating an immune response of the islets. Prevention of increased expression of ICAM-1 or VCAM-1 and reduction of lymphocyte adhesion in islets by silica or antibody indicate an involvement of macrophages and macrophage derived cytokines in the generation of this immune response.
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Affiliation(s)
- R Ludwig
- Department of Medicine I, J.W. Goethe University, Frankfurt am Main, Germany
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Kusterer K, Pohl T, Fortmeyer HP, März W, Scharnagl H, Oldenburg A, Angermüller S, Fleming I, Usadel KH, Busse R. Chronic selective hypertriglyceridemia impairs endothelium-dependent vasodilatation in rats. Cardiovasc Res 1999; 42:783-93. [PMID: 10533619 DOI: 10.1016/s0008-6363(98)00331-9] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/18/2022] Open
Abstract
OBJECTIVE/METHODS In order to investigate whether selective hypertriglyceridemia impairs endothelium-dependent vasodilatation in the rat hindlimb, rats were selectively bred to establish two strains, one with a pronounced hypertriglyceridemia (HT) and the other with normal plasma levels of triglycerides (LT). RESULTS Carotid arteries and aortae removed from 3, 6, 9 and 12 month old LT- and HT-rats exhibited a normal morphology. However, marked morphological differences were observed between vessels from 18-20 month old HT- and LT-rats. The endothelium-dependent vasodilator acetylcholine (2 to 50 micrograms/kg), administered into the iliac artery, elicited a concentration-dependent increase in hindlimb blood flow which was not different in 3, 6 and 9 month old LT- or HT-rats but was impaired in 12 and 18-20 month old HT-rats. In contrast the endothelium-independent vasodilator sodium nitroprusside enhanced blood flow in both strains to a similar extent. Neither administration of the nitric oxide (NO) synthase (NOS) substrate, L-arginine, nor the NOS inhibitor NGnitro-L-arginine, affected the responsiveness to endothelium-dependent vasodilators in 12 month old HT-rats. These attenuated responses could not be attributed to a decrease in endothelial NOS expression as Western blot analysis revealed identical levels of this enzyme in the aortae and carotid arteries from LT- and HT-rats. Determination of superoxide anion (O2-) formation however, demonstrated a markedly elevated production of O2- in aortae from HT-rats. CONCLUSION We conclude that chronic selective hypertriglyceridemia, an independent risk factor in the development and progression of atherosclerosis, leads to an endothelial dysfunction which is associated with an increased vascular O2- production and a subsequent decrease in bioavailable NO.
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Affiliation(s)
- K Kusterer
- Department of Internal Medicine I, Johann Wolfgang Goethe University, Frankfurt am Main, Germany
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30
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Enghofer M, Bojunga J, Ludwig R, Oldenburg A, Bernd A, Usadel KH, Kusterer K. Lymphocyte transfer in streptozotocin-induced diabetes: adhesion of donor cells to islet endothelium. Am J Physiol 1998; 274:E928-35. [PMID: 9612252 DOI: 10.1152/ajpendo.1998.274.5.e928] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The interaction between intravenously transferred lymphocytes derived from spleens of multiple low-dose streptozotocin-diabetic mice with islet, exocrine pancreatic, and gastric mucosal endothelium of nondiabetic recipient mice was investigated by in vivo microscopy. Donor lymphocytes were stained with acridine red in vitro. The adoptive transfer of these cells from diabetic donor animals resulted in significantly increased lymphocyte rolling (4.46 +/- 1.32%, P < 0.05) and adhesion (3.86 +/- 1.04%, P < 0.05) in islets of nondiabetic recipients that had been pretreated with a single subdiabetogenic dose of streptozotocin. No increased endothelial interaction was noted in nonpretreated recipients or in experiments with nondiabetic donors. Rolling (1.19 +/- 0.61 to 2.71 +/- 0.62%) and adhesion (0.61 +/- 0.33 to 2.80 +/- 0.97%) of donor lymphocytes were low in exocrine pancreatic and gastric mucosal control tissue. It is concluded that, in this animal model, lymphocytes from diabetic donors interact preferentially with recipient islet endothelium. However, additional stimulation of recipient islet endothelium by exogenous factors is necessary to enable transferred cells to adhere to pancreatic islets.
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Affiliation(s)
- M Enghofer
- Department of Medicine I, Johann Wolfgang Goethe University, Frankfurt am Main, Germany
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31
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Scheiman JM, Tillner A, Pohl T, Oldenburg A, Angermüller S, Görlach E, Engel G, Usadel KH, Kusterer K. Reduction of non-steroidal anti-inflammatory drug induced gastric injury and leucocyte endothelial adhesion by octreotide. Gut 1997; 40:720-5. [PMID: 9245924 PMCID: PMC1027195 DOI: 10.1136/gut.40.6.720] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
BACKGROUND Non-steroidal anti-inflammatory drugs (NSAIDs) induce gastric ulcers. AIMS To assess whether the somatostatin analogue octreotide prevents NSAID induced mucosal gastrointestinal damage in both animals and humans. The effect of octreotide on neutrophil adhesion to the endothelium was also evaluated. METHODS Male Sprague-Dawley rats were pretreated either with saline (0.3 ml subcutaneously) or octreotide (0.001-1 ng/kg subcutaneously). After 30 minutes gastric ulcers were induced by the intragastric application of NSAIDs (20 mg/kg indomethacin, 200 mg/kg aspirin, 200 mg/kg ibuprofen, or 50 mg/kg diclofenac). Four hours later the rats were killed and gastric mucosal lesions were assessed by computed planimetry. To determine whether octreotide could prevent indomethacin induced injury in humans, 20 healthy volunteers were evaluated in a double blind, placebo controlled study. RESULTS Octreotide prevented NSAID induced gastric mucosal lesions (p < 0.05). The dose response curve was U shaped and the most effective dose was 0.1 ng/kg. Leucocyte adherence in submucosal venules of the stomach was evaluated by in vivo microscopy. Octreotide (0.1 ng/kg subcutaneously) prevented indomethacin (20 mg/kg intragastric) induced leucocyte adherence in gastric submucosal venules (p < 0.05). Healthy human volunteers received 50 mg indomethacin orally thrice a day concomitantly with either an identical placebo or 0.01 microgram, 0.1 microgram, or 1 microgram octreotide subcutaneously thrice a day for three days. Injury was assessed by endoscopy. There was a negative correlation between the octreotide dose and injury score (p < 0.03 for gastric injury, p < 0.001 for duodenal injury). CONCLUSIONS Octreotide protects the stomach from NSAID induced gastric injury, probably via its ability to reduce NSAID induced neutrophilic adhesion to the microvasculature. Octreotide also ameliorated indomethacin induced gastric and duodenal injury in humans.
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Affiliation(s)
- J M Scheiman
- Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, USA
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