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Yilmaz O, Jensen AM, Harboe T, Møgster M, Jensen RM, Mjaavatten O, Birkeland E, Spriet E, Sandven L, Furmanek T, Berven FS, Wargelius A, Norberg B. Quantitative proteome profiling reveals molecular hallmarks of egg quality in Atlantic halibut: impairments of transcription and protein folding impede protein and energy homeostasis during early development. BMC Genomics 2022; 23:635. [PMID: 36071374 PMCID: PMC9450261 DOI: 10.1186/s12864-022-08859-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Accepted: 08/30/2022] [Indexed: 11/24/2022] Open
Abstract
Background Tandem mass tag spectrometry (TMT labeling-LC-MS/MS) was utilized to examine the global proteomes of Atlantic halibut eggs at the 1-cell-stage post fertilization. Comparisons were made between eggs judged to be of good quality (GQ) versus poor quality (BQ) as evidenced by their subsequent rates of survival for 12 days. Altered abundance of selected proteins in BQ eggs was confirmed by parallel reaction monitoring spectrometry (PRM-LC-MS/MS). Correspondence of protein levels to expression of related gene transcripts was examined via qPCR. Potential mitochondrial differences between GQ and BQ eggs were assessed by transmission electron microscopy (TEM) and measurements of mitochondrial DNA (mtDNA) levels. Results A total of 115 proteins were found to be differentially abundant between GQ and BQ eggs. Frequency distributions of these proteins indicated higher protein folding activity in GQ eggs compared to higher transcription and protein degradation activities in BQ eggs. BQ eggs were also significantly enriched with proteins related to mitochondrial structure and biogenesis. Quantitative differences in abundance of several proteins with parallel differences in their transcript levels were confirmed in egg samples obtained over three consecutive reproductive seasons. The observed disparities in global proteome profiles suggest impairment of protein and energy homeostasis related to unfolded protein response and mitochondrial stress in BQ eggs. TEM revealed BQ eggs to contain significantly higher numbers of mitochondria, but differences in corresponding genomic mtDNA (mt-nd5 and mt-atp6) levels were not significant. Mitochondria from BQ eggs were significantly smaller with a more irregular shape and a higher number of cristae than those from GQ eggs. Conclusion The results of this study indicate that BQ Atlantic halibut eggs are impaired at both transcription and translation levels leading to endoplasmic reticulum and mitochondrial disorders. Observation of these irregularities over three consecutive reproductive seasons in BQ eggs from females of diverse background, age and reproductive experience indicates that they are a hallmark of poor egg quality. Additional research is needed to discover when in oogenesis and under what circumstances these defects may arise. The prevalence of this suite of markers in BQ eggs of diverse vertebrate species also begs investigation. Supplementary Information The online version contains supplementary material available at 10.1186/s12864-022-08859-0.
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Affiliation(s)
- Ozlem Yilmaz
- Institute of Marine Research, Austevoll Research Station, 5392, Storebø, Norway.
| | | | - Torstein Harboe
- Institute of Marine Research, Austevoll Research Station, 5392, Storebø, Norway
| | - Margareth Møgster
- Institute of Marine Research, Austevoll Research Station, 5392, Storebø, Norway
| | | | - Olav Mjaavatten
- Department of Biomedicine, The Proteomics Facility of the University of Bergen (PROBE), 5009, Bergen, Norway
| | - Even Birkeland
- Department of Biomedicine, The Proteomics Facility of the University of Bergen (PROBE), 5009, Bergen, Norway
| | - Endy Spriet
- Department of Biomedicine, The Molecular Imaging Center (MIC), University of Bergen, 5009, Bergen, Norway
| | - Linda Sandven
- Department of Biomedicine, The Molecular Imaging Center (MIC), University of Bergen, 5009, Bergen, Norway
| | - Tomasz Furmanek
- Institute of Marine Research, P.O. Box 1870, Nordnes, 5817, Bergen, Norway
| | - Frode S Berven
- Department of Biomedicine, The Proteomics Facility of the University of Bergen (PROBE), 5009, Bergen, Norway
| | - Anna Wargelius
- Institute of Marine Research, P.O. Box 1870, Nordnes, 5817, Bergen, Norway
| | - Birgitta Norberg
- Institute of Marine Research, Austevoll Research Station, 5392, Storebø, Norway
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Binder V, Bergum B, Jaisson S, Gillery P, Scavenius C, Spriet E, Nyhaug AK, Roberts HM, Chapple ILC, Hellvard A, Delaleu N, Mydel P. Impact of fibrinogen carbamylation on fibrin clot formation and stability. Thromb Haemost 2017; 117:899-910. [PMID: 28382370 PMCID: PMC5442607 DOI: 10.1160/th16-09-0704] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2016] [Accepted: 02/07/2016] [Indexed: 01/20/2023]
Abstract
Carbamylation is a non-enzymatic post-translational modification induced upon exposure of free amino groups to urea-derived cyanate leading to irreversible changes of protein charge, structure and function. Levels of carbamylated proteins increase significantly in chronic kidney disease and carbamylated albumin is considered as an important biomarker indicating mortality risk. High plasma concentrations and long half-life make fibrinogen a prime target for carbamylation. As aggregation and cross-linking of fibrin monomers rely on lysine residues, it is likely that carbamylation impacts fibrinogen processing. In this study we investigated carbamylation levels of fibrinogen from kidney disease patients as well as the impact of carbamylation on fibrinogen cleavage by thrombin, fibrin polymerisation and cross-linking in vitro. In conjunction, all these factors determine clot structure and stability and thus control biochemical and mechanical properties. LC-MS/MS analyses revealed significantly higher homocitrulline levels in patient fibrinogen than in fibrinogen isolated from control plasma. In our in vitro studies we found that although carbamylation does not affect thrombin cleavage per se, it alters fibrin polymerisation kinetics and impairs cross-linking and clot degradation. In addition, carbamylated fibrin clots had reduced fiber size and porosity associated with decreased mechanical stability. Using mass spectroscopy, we discovered that N-terminally carbamylated fibrinopeptide A was generated in this process and acted as a strong neutrophil chemoattractant potentially mediating recruitment of inflammatory cells to sites of fibrin(ogen) turnover. Taken together, carbamylation of fibrinogen seems to play a role in aberrant fibrin clot formation and might be involved in haemostatic disorders associated with chronic inflammatory diseases.
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Affiliation(s)
- Veronika Binder
- Veronika Binder, Broegelmann Research Laboratory, Department of Clinical Science, University of Bergen, The Laboratory Building, 5th floor, Bergen, Norway, Tel.: +47 55 97 46 48, Fax: +47 55 97 58 17, E-mail:
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Van Nieuwenhove Y, Spriet E, Sablon T, Van Daele E, Willaert W, Ceelen W, Pattyn P. Metabolic surgery in patients over 60 years old: short- and long-term results. Acta Chir Belg 2016; 116:362-366. [PMID: 27426660 DOI: 10.1080/00015458.2016.1181323] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [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: 12/28/2022]
Abstract
PURPOSE Laparoscopic Roux-en-Y gastric bypass can treat obesity related comorbidities and can prolong life expectancy. It remains unclear whether this type of surgery is also indicated in obese patients with advanced age. MATERIALS AND METHODS In this retrospective monocentric study, we investigated the morbidity and outcomes of weight and metabolic control of bariatric surgery in patients older than 60 years and compared these findings with those of younger patients. RESULTS At 18 months after RY gastric bypass, weight losses of respectively 30 ± 11% and 34 ± 9% of total initial body weight were measured in the older and younger patients (p < 0.05). After 12 months, HbA1c dropped below 6.5% in 89% of patients younger and in 81% of patients older than 60 (p = 0.11). There was no mortality in either group, but there were significantly more complications and there was a longer hospital stay in the older patients. CONCLUSION RY gastric bypass comes with a significantly higher morbidity and hospital stay in older patients, but weight loss and improvement of DM are similar as in the younger patients.
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Affiliation(s)
- Y. Van Nieuwenhove
- Department of Gastrointestinal Surgery, Ghent University Hospital, Ghent, Belgium
| | - E. Spriet
- Department of Gastrointestinal Surgery, Ghent University Hospital, Ghent, Belgium
| | - T. Sablon
- Department of Gastrointestinal Surgery, Ghent University Hospital, Ghent, Belgium
| | - E. Van Daele
- Department of Gastrointestinal Surgery, Ghent University Hospital, Ghent, Belgium
| | - W. Willaert
- Department of Gastrointestinal Surgery, Ghent University Hospital, Ghent, Belgium
| | - W. Ceelen
- Department of Gastrointestinal Surgery, Ghent University Hospital, Ghent, Belgium
| | - P. Pattyn
- Department of Gastrointestinal Surgery, Ghent University Hospital, Ghent, Belgium
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Aasen SN, Pospisilova A, Eichler TW, Panek J, Hruby M, Stepanek P, Spriet E, Jirak D, Skaftnesmo KO, Thorsen F. A Novel Nanoprobe for Multimodal Imaging Is Effectively Incorporated into Human Melanoma Metastatic Cell Lines. Int J Mol Sci 2015; 16:21658-80. [PMID: 26370983 PMCID: PMC4613273 DOI: 10.3390/ijms160921658] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2015] [Revised: 08/07/2015] [Accepted: 08/25/2015] [Indexed: 02/04/2023] Open
Abstract
To facilitate efficient drug delivery to tumor tissue, several nanomaterials have been designed, with combined diagnostic and therapeutic properties. In this work, we carried out fundamental in vitro and in vivo experiments to assess the labeling efficacy of our novel theranostic nanoprobe, consisting of glycogen conjugated with a red fluorescent probe and gadolinium. Microscopy and resazurin viability assays were used to study cell labeling and cell viability in human metastatic melanoma cell lines. Fluorescence lifetime correlation spectroscopy (FLCS) was done to investigate nanoprobe stability. Magnetic resonance imaging (MRI) was performed to study T1 relaxivity in vitro, and contrast enhancement in a subcutaneous in vivo tumor model. Efficient cell labeling was demonstrated, while cell viability, cell migration, and cell growth was not affected. FLCS showed that the nanoprobe did not degrade in blood plasma. MRI demonstrated that down to 750 cells/μL of labeled cells in agar phantoms could be detected. In vivo MRI showed that contrast enhancement in tumors was comparable between Omniscan contrast agent and the nanoprobe. In conclusion, we demonstrate for the first time that a non-toxic glycogen-based nanoprobe may effectively visualize tumor cells and tissue, and, in future experiments, we will investigate its therapeutic potential by conjugating therapeutic compounds to the nanoprobe.
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Affiliation(s)
- Synnøve Nymark Aasen
- NorLux Neuro-Oncology Laboratory, Department of Biomedicine, University of Bergen, 5020 Bergen, Norway.
| | - Aneta Pospisilova
- Institute of Macromolecular Chemistry, Academy of Sciences of the Czech Republic, 162 06 Prague, Czech Republic.
| | - Tilo Wolf Eichler
- Department of Clinical Medicine, University of Bergen, 5020 Bergen, Norway.
| | - Jiri Panek
- Institute of Macromolecular Chemistry, Academy of Sciences of the Czech Republic, 162 06 Prague, Czech Republic.
| | - Martin Hruby
- Institute of Macromolecular Chemistry, Academy of Sciences of the Czech Republic, 162 06 Prague, Czech Republic.
| | - Petr Stepanek
- Institute of Macromolecular Chemistry, Academy of Sciences of the Czech Republic, 162 06 Prague, Czech Republic.
| | - Endy Spriet
- Molecular Imaging Center, Department of Biomedicine, University of Bergen, 5020 Bergen, Norway.
| | - Daniel Jirak
- Department of Diagnostic and Interventional Radiology, Institute for Clinical and Experimental Medicine, 140 21 Prague, Czech Republic.
- Institute of Biophysics and Informatics, 1st Medicine Faculty, Charles University, 120 00 Prague, Czech Republic.
| | - Kai Ove Skaftnesmo
- NorLux Neuro-Oncology Laboratory, Department of Biomedicine, University of Bergen, 5020 Bergen, Norway.
| | - Frits Thorsen
- NorLux Neuro-Oncology Laboratory, Department of Biomedicine, University of Bergen, 5020 Bergen, Norway.
- Molecular Imaging Center, Department of Biomedicine, University of Bergen, 5020 Bergen, Norway.
- Kristian Gerhard Jebsen Brain Tumour Research Centre, Department of Biomedicine, University of Bergen, 5020 Bergen, Norway.
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Aasen SN, Eichler TW, Hruby M, Pospisilova A, Stepanek P, Spriet E, Jirak D, Skaftnesmo KO, Thorsen F. Abstract 5195: A novel, multimodal theranostic nanoprobe is effectively incorporated into melanoma brain metastatic cells. Cancer Res 2015. [DOI: 10.1158/1538-7445.am2015-5195] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Metastatic cancer is a significant cause of death worldwide, despite continuing advances in research on diagnostics and therapy. To overcome unsuccessful drug delivery to the tumor tissue, several different nanoprobes have been designed, of which some have combined diagnostic and therapeutic properties. It is an advantage to use non-toxic, biodegradable materials in the design of nanoprobes, as such compounds are easily eliminated from the body. In this work we report for the first time the use of a recently developed nanoprobe to label melanoma metastatic cell lines, for multimodal imaging of cellular uptake and drug delivery. Our nanoprobe consisted of a backbone of glycogen, where the red fluorescent marker Dyo-615 for fluorescence microscopy and Gadolinium for MRI were incorporated.
Fluorescence microscopy showed effective labeling of human melanoma metastatic cells over 24 hours and cell viability was not affected by the labeling. The nanoprobe was found in the cytosol of the cells, and a gradual degradation of the probe inside the lysosomes could be observed. In vitro MRI relaxivity measurements showed significant reduction in T1 mapping times, compared to unlabeled cells. In vivo MRI studies showed that subcutaneous melanoma tumors in mice could be effectively visualized with T1 weighted MRI after intravenous injection of the nanoprobe, and the contrast enhancement was comparable to what was seen after using standard Omniscan contrast agent.
In summary, our biodegradable glycogen nanoprobe shows a high potential to be used further as a theranostic entity. The nanoprobe may offer additional advantages over MRI contrast agents, as tumor uptake of pharmaceuticals attached to the nanoprobe can be traced in real-time in vivo.
Citation Format: Synnøve N. Aasen, Tilo W. Eichler, Martin Hruby, Aneta Pospisilova, Petr Stepanek, Endy Spriet, Daniel Jirak, Kai Ove Skaftnesmo, Frits Thorsen. A novel, multimodal theranostic nanoprobe is effectively incorporated into melanoma brain metastatic cells. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 5195. doi:10.1158/1538-7445.AM2015-5195
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Affiliation(s)
| | | | - Martin Hruby
- 3Institute of Macromolecular Chemistry, Prague, Czech Republic
| | | | - Petr Stepanek
- 3Institute of Macromolecular Chemistry, Prague, Czech Republic
| | | | - Daniel Jirak
- 4Institute for Clinical and Experimental Medicine, Prague, Czech Republic
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Flood PR, Spriet E, Erichsen ES, Dovgal IV. FIRST RECORD OF A CILIATE SUCTORIAN (CILIOPHORA, SUCTOREA) EPIBIONT ON THE JELLYFISH PELAGIA NOCTILUCA (SCYPHOZOA, SEMAEOSTOMAEIDA). Ecol Mont 2015. [DOI: 10.37828/em.2015.2.36] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In the course of a survey of a specimen of the jellyfish Pelagia noctiluca (collected at Villefranche-sur-Mer, France) using scanning electron microscopy, the suctorian ciliate Trichophrya salparum was found on the jellyfish exumbrella. This ciliate species is reported for the first time on a scyphozoan jellyfish host. A redescription of this suctorian species is presented together with data on its distribution and host prevalence.
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Rebbestad K, Herredsvela S, Sornes S, Eide GE, Müller KE, Spriet E, Sjursen H, Naess A. Flow cytometry technique for analysing Leishmania promastigote phagocytosis by human polymorphonuclear leucocytes and monocytes. Parasite Immunol 2012; 34:528-35. [PMID: 22845183 DOI: 10.1111/j.1365-3024.2012.01385.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
In this study, we developed a flow cytometry technique for studying Leishmania (L.) mexicana phagocytosis by human polymorphonuclear leucocytes (PMNs) and monocytes. Leishmania promastigotes are elongated in shape and flagellated. This influences the light scatter when phagocytosis is measured by flow cytometry. Accordingly, we developed an oxidative burst method for measuring the phagocytic process. As this is an indirect marker of phagocytosis, we used confocal, light and electron microscopy to verify that promastigotes were, indeed, internalized by the phagocytes. For both PMNs and monocytes, the optimal conditions for achieving high sensitivity in flow cytometry detection were 5% pooled human serum and 15 min. incubation time. Incubations at 35, 37 and 39°C were also equally efficient for both PMNs and monocytes. Optimal parasite ratios were 10 parasites per PMN and 20 parasites per monocyte. Under these conditions, Leishmania were readily phagocytosed by human PMNs and monocytes and the effects of other influences, such as treatment, would be readily detectable. This indicated that these cells may play a role in the immune response against Leishmania.
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Affiliation(s)
- K Rebbestad
- Institute of Medicine, University of Bergen, Bergen, Norway.
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Ardawatia VV, Masià-Balagué M, Krakstad BF, Johansson BB, Kreitzburg KM, Spriet E, Lewis AE, Meigs TE, Aragay AM. Gα12 binds to the N-terminal regulatory domain of p120ctn, and downregulates p120ctn tyrosine phosphorylation induced by Src family kinases via a RhoA independent mechanism. Exp Cell Res 2011; 317:293-306. [DOI: 10.1016/j.yexcr.2010.10.017] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2010] [Revised: 10/18/2010] [Accepted: 10/18/2010] [Indexed: 01/23/2023]
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Bouquet JM, Spriet E, Troedsson C, Otterå H, Chourrout D, Thompson EM. Culture optimization for the emergent zooplanktonic model organism Oikopleura dioica. J Plankton Res 2009; 31:359-370. [PMID: 19461862 PMCID: PMC2651036 DOI: 10.1093/plankt/fbn132] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/23/2008] [Accepted: 12/09/2008] [Indexed: 05/16/2023]
Abstract
The pan-global marine appendicularian, Oikopleura dioica, shows considerable promise as a candidate model organism for cross-disciplinary research ranging from chordate genetics and evolution to molecular ecology research. This urochordate, has a simplified anatomical organization, remains transparent throughout an exceptionally short life cycle of less than 1 week and exhibits high fecundity. At 70 Mb, the compact, sequenced genome ranks among the smallest known metazoan genomes, with both gene regulatory and intronic regions highly reduced in size. The organism occupies an important trophic role in marine ecosystems and is a significant contributor to global vertical carbon flux. Among the short list of bona fide biological model organisms, all share the property that they are amenable to long-term maintenance in laboratory cultures. Here, we tested diet regimes, spawn densities and dilutions and seawater treatment, leading to optimization of a detailed culture protocol that permits sustainable long-term maintenance of O. dioica, allowing continuous, uninterrupted production of source material for experimentation. The culture protocol can be quickly adapted in both coastal and inland laboratories and should promote rapid development of the many original research perspectives the animal offers.
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Affiliation(s)
- Jean-Marie Bouquet
- Sars International Centre for Marine Molecular Biology, Thormøhlensgate 55, N-5008 Bergen, Norway
| | - Endy Spriet
- Sars International Centre for Marine Molecular Biology, Thormøhlensgate 55, N-5008 Bergen, Norway
- corresponding author:
| | - Christofer Troedsson
- Sars International Centre for Marine Molecular Biology, Thormøhlensgate 55, N-5008 Bergen, Norway
- Department of Biology, University of Bergen, N-5020 Bergen, Norway
| | - Helen Otterå
- Sars International Centre for Marine Molecular Biology, Thormøhlensgate 55, N-5008 Bergen, Norway
| | - Daniel Chourrout
- Sars International Centre for Marine Molecular Biology, Thormøhlensgate 55, N-5008 Bergen, Norway
| | - Eric M. Thompson
- Sars International Centre for Marine Molecular Biology, Thormøhlensgate 55, N-5008 Bergen, Norway
- corresponding author:
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Seo HC, Kube M, Edvardsen RB, Jensen MF, Beck A, Spriet E, Gorsky G, Thompson EM, Lehrach H, Reinhardt R, Chourrout D. Miniature genome in the marine chordate Oikopleura dioica. Science 2001; 294:2506. [PMID: 11752568 DOI: 10.1126/science.294.5551.2506] [Citation(s) in RCA: 132] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Affiliation(s)
- H C Seo
- Sars [corrected] Centre for Marine Molecular Biology, Thormø- hlensgt. 55, 5020 Bergen, Norway
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Spada F, Steen H, Troedsson C, Kallesoe T, Spriet E, Mann M, Thompson EM. Molecular patterning of the oikoplastic epithelium of the larvacean tunicate Oikopleura dioica. J Biol Chem 2001; 276:20624-32. [PMID: 11279070 DOI: 10.1074/jbc.m100438200] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.0] [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: 11/06/2022] Open
Abstract
Appendicularia are protochordates that rely on a complex mucous secretion, the house, to filter food particles from seawater. A monolayer of cells covering the trunk of the animal, the oikoplastic epithelium, secretes the house. This epithelium contains a fixed number of cells arranged in characteristic patterns with distinct sizes and nuclear morphologies. Certain house structures appear to be spatially related to defined, underlying groups of cells in the epithelium. We show that the house is composed of at least 20 polypeptides, a number of which are highly glycosylated, with glycosidase treatments resulting in molecular mass shifts exceeding 100 kDa. Nanoelectrospray tandem mass spectrometric microsequencing of house polypeptides was used to design oligonucleotides to screen an adult Oikopleura dioica cDNA library. This resulted in the isolation of cDNAs coding for three different proteins, oikosin 1, oikosin 2, and oikosin 3. The latter two are novel proteins unrelated to any known data base entries. Oikosin 1 has 13 repeats of a Cys domain, previously identified as a subunit of repeating sequences in some vertebrate mucins. We also find one repeat of this Cys domain in human cartilage intermediate layer protein but find no evidence of this domain in any invertebrate species, including those for which entire genomes have been sequenced. The three oikosins show distinct and complementary expression patterns restricted to the oikoplastic epithelium. This easily accessible epithelium, with differential gene expression patterns in readily identifiable groups of cells with distinctive nuclear morphologies, is a highly attractive model system for molecular studies of pattern formation.
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Affiliation(s)
- F Spada
- Sars International Centre for Marine Molecular Biology, Bergen High Technology Centre, N-5008 Bergen, Norway
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