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Aune Westergaard Hansen G, Ludvigsen M, Jacobsen C, Cangemi C, Melholt Rasmussen L, Vorum H, Honoré B. Fibulin-1C, C1 Esterase Inhibitor and Glucose Regulated Protein 75 Interact with the CREC Proteins, Calumenin and Reticulocalbin. PLoS One 2015; 10:e0132283. [PMID: 26161649 PMCID: PMC4498735 DOI: 10.1371/journal.pone.0132283] [Citation(s) in RCA: 4] [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] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2015] [Accepted: 06/11/2015] [Indexed: 01/12/2023] Open
Abstract
Affinity purification, immunoprecipitation, gel electrophoresis and mass spectrometry were used to identify fibulin-1C, C1 esterase inhibitor and glucose regulated protein 75, grp75, as binding partners of the CREC proteins, calumenin and reticulocalbin. Surface plasmon resonance was used to verify the interaction of all three proteins with each of the CREC proteins. Fibulin-1C interacts with calumenin and reticulocalbin with an estimated dissociation constant around 50-60 nM. The interaction, at least for reticulocalbin, was not dependent upon the presence of Ca2+. C1 esterase inhibitor interacted with both proteins with an estimated dissociation constant at 1 μM for reticulocalbin and 150 nM for calumenin. The interaction, at least for calumenin, was dependent upon the presence of Ca2+ with strong interaction at 3.5 mM while no detectable interaction could be found at 0.1 mM. Grp75 binds with an affinity of approximately 3-7 nM with reticulocalbin as well as with calumenin. These interactions suggest functional participation of the CREC proteins in chaperone activity, cell proliferation and transformation, cellular aging, haemostasis and thrombosis as well as modulation of the complement system in fighting bacterial infection.
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Affiliation(s)
| | - Maja Ludvigsen
- Department of Biomedicine, Ole Worms Allé 3, Building 1182, Aarhus University, DK-8000 Aarhus C, Denmark
| | - Christian Jacobsen
- Department of Biomedicine, Ole Worms Allé 3, Building 1182, Aarhus University, DK-8000 Aarhus C, Denmark
| | - Claudia Cangemi
- Department of Clinical Biochemistry and Pharmacology, Center for Individualized Medicine in Arterial Diseases (CIMA), Odense University Hospital, Sdr. Boulevard 29, DK-5000 Odense C, Denmark
| | - Lars Melholt Rasmussen
- Department of Clinical Biochemistry and Pharmacology, Center for Individualized Medicine in Arterial Diseases (CIMA), Odense University Hospital, Sdr. Boulevard 29, DK-5000 Odense C, Denmark
| | - Henrik Vorum
- Department of Ophthalmology, Aalborg University Hospital, Hobrovej 18–22, 9100 Aalborg, Denmark
| | - Bent Honoré
- Department of Biomedicine, Ole Worms Allé 3, Building 1182, Aarhus University, DK-8000 Aarhus C, Denmark
- * E-mail:
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2
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Abstract
Syndactyly, webbing of adjacent digits with or without bony fusion, is one of the most common hereditary limb malformations. It occurs either as an isolated abnormality or as a component of more than 300 syndromic anomalies. There are currently nine types of phenotypically diverse nonsyndromic syndactyly. Non-syndromic syndactyly is usually inherited as an autosomal dominant trait, although the more severe presenting types and subtypes may show autosomal recessive or X-linked pattern of inheritance. The phenotype appears to be not only caused by a main gene, but also dependant on genetic background and subsequent signaling pathways involved in limb formation. So far, the principal genes identified to be involved in congenital syndactyly are mainly involved in the zone of polarizing activity and sonic hedgehog pathway. This review summarizes the recent progress made in the molecular genetics, including known genes and loci responsible for non-syndromic syndactyly, and the signaling pathways those genetic factors involved in, as well as clinical features and animal models. We hope our review will contribute to the understanding of underlying pathogenesis of this complicated disorder and have implication on genetic counseling.
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Affiliation(s)
- Hao Deng
- Center for Experimental Medicine ; Department of Neurology, the Third Xiangya Hospital, Central South University, Changsha, China
| | - Ting Tan
- Center for Experimental Medicine
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3
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Twal WO, Hammad SM, Guffy SL, Argraves WS. A novel intracellular fibulin-1D variant binds to the cytoplasmic domain of integrin beta 1 subunit. Matrix Biol 2015; 43:97-108. [PMID: 25661773 DOI: 10.1016/j.matbio.2015.01.021] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2014] [Revised: 01/26/2015] [Accepted: 01/26/2015] [Indexed: 01/03/2023]
Abstract
Fibulin-1 is a member of a growing family of proteins that includes eight members and is involved in cellular functions such as adhesion, migration and differentiation. Fibulin-1 has also been implicated in embryonic development of the heart and neural crest-derived structures. It is an integral part of the extracellular matrix (ECM) and has been shown to bind to a multitude of ECM proteins. However, fibulin-1 was first identified as a protein purified from placental extracts that binds to the cytoplasmic domain of integrin β1. Human fibulin-1 is alternatively spliced into four different isoforms namely A-D. These isoforms share a common N-terminus sequence that contains a secretion sequence but differ in their carboxy-terminal fibulin-1 module. In this report we identify a new splice variant of fibulin-1 that differs from all other fibulin-1 variants in the N-terminus sequence and has a similar carboxy-terminus sequence as fibulin-1D. This variant that we named fibulin-1D prime (fibulin-1D') lacks a secretion sequence and the anaphlatoxin region of fibulin-1 variants. The protein has an apparent molecular weight of 70.5kDa. Herein we show that fibulin-1D' binds to the intracellular domain of integrin β1 as well as to integrin α5β1. The protein was localized intracellularly in CHO cells transfected with a pEF4 plasmid containing full-length coding sequence of fibulin-1D'. We also localized the protein in human placenta. We propose that the fibulin-1D' variant might play a role in early embryo development as well as in modulating integrin β1 functions including adhesion and motility.
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Affiliation(s)
- Waleed O Twal
- Department of Regenerative Medicine and Cell Biology, Medical University of South Carolina, 173 Ashley Avenue, MSC 508, Charleston, SC 29412, USA.
| | - Samar M Hammad
- Department of Regenerative Medicine and Cell Biology, Medical University of South Carolina, 173 Ashley Avenue, MSC 508, Charleston, SC 29412, USA.
| | - Sharon L Guffy
- Department of Regenerative Medicine and Cell Biology, Medical University of South Carolina, 173 Ashley Avenue, MSC 508, Charleston, SC 29412, USA
| | - William S Argraves
- Department of Regenerative Medicine and Cell Biology, Medical University of South Carolina, 173 Ashley Avenue, MSC 508, Charleston, SC 29412, USA
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Alcendor DJ, Knobel S, Desai P, Zhu WQ, Hayward GS. KSHV regulation of fibulin-2 in Kaposi's sarcoma: implications for tumorigenesis. Am J Pathol 2011; 179:1443-54. [PMID: 21741351 DOI: 10.1016/j.ajpath.2011.05.024] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/07/2010] [Revised: 04/18/2011] [Accepted: 05/17/2011] [Indexed: 10/18/2022]
Abstract
Kaposi's sarcoma is an angioproliferative tumor caused by Kaposi's sarcoma-associated herpesvirus (KSHV) infection of vascular endothelial cells. Fibulins, proteins that associate with extracellular matrix (ECM) proteins, may have both tumor-suppressive and oncogenic activities. We found that the expression of fibulin-2 protein and mRNA were decreased 50-fold and 26-fold, respectively, in 10-day KSHV-infected dermal microvascular endothelial cells (DMVEC). Using quantitative RT-PCR, we found a fivefold and 25-fold decrease of fibulin-2 extracellular matrix binding partners, fibronectin and tropoelastin, respectively. Time-course transcriptional analyses over 10 days showed that in addition to that of fibulin-2, expression of fibulins 3 and 5 was decreased in KSHV-infected DMVEC, fibulins 1C/1D were increased, and fibulins 4, 6, and 7 were unchanged. KSHV latency-associated nuclear antigen (LANA) transcription levels rose consistently over the same period. Addition of recombinant fibulin-3 or -5 for 48 hours to 10-day KSHV-infected cells caused a suppression of KSHV-induced vascular endothelial growth factor (VEGF) protein and mRNA levels. Recombinant fibulin-3 also significantly reduced VEGF receptor 3 expression. In pleural effusion lymphoma cell lines that express variable levels of KSHV lytic replication, we observed no detectable fibulin-2 or -5 expression. Finally, fibulin-2 expression was decreased in tissue microarrays from KSHV-infected, LANA-positive patient cells as compared to that in patient nontumor controls. Understanding the interactions between KSHV and the fibulins may lead to the development of novel therapies for treatment of Kaposi's sarcoma.
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Affiliation(s)
- Donald J Alcendor
- Meharry Medical College, School of Medicine, Center for AIDS Health Disparities Research, Nashville, Tennessee, USA.
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Cheng YY, Jin H, Liu X, Siu JMT, Wong YP, Ng EKO, Yu J, Leung WK, Sung JJY, Chan FKL. Fibulin 1 is downregulated through promoter hypermethylation in gastric cancer. Br J Cancer 2008; 99:2083-7. [PMID: 18985039 PMCID: PMC2607230 DOI: 10.1038/sj.bjc.6604760] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.1] [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] [Indexed: 12/27/2022] Open
Abstract
Tumour suppressor genes (TSGs) were frequently inactivated through promoter hypermethylation in gastric carcinoma as well as pre-malignant gastric lesions, suggesting that promoter hypermethylation can be used as a marker to define novel TSGs and also biomarkers for early detection of gastric cancer. In an effort to search for such genes aberrantly methylated in gastric cancer development, fibulin 1 (FBLN1) was found as a candidate TSG epigenetically downregulated in gastric cancer. FBLN1 expression was downregulated in all of gastric cancer cell lines used (100%, 7 out of 7) and the primary gastric carcinoma tissues (84%, 86 out of 102) and significantly restored after pharmacological demethylation. Hypermethylation of the FBLN1 promoter was frequently (71%, 5 out of 7) detected in gastric cancer cell lines and primary gastric carcinoma tissues. Ectopic expression of FBLN1 led to the growth inhibition of gastric cancer cells through the induction of apoptosis. In summary, FBLN1 was identified as a novel candidate TSG epigenetically downregulated in gastric cancer.
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Affiliation(s)
- Y Y Cheng
- Department of Medicine and Therapeutics, Institute of Digestive Disease, Faculty of Medicine, Li Ka Shing Institute of Health Sciences, The Chinese University of Hong Kong, Hong Kong SAR, China
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Singh U, Sun T, Larsson T, Elliott RW, Kostka G, Fundele RH. Expression and Functional Analysis of Fibulin-1 (Fbln1) During Normal and Abnormal Placental Development of the Mouse. Placenta 2006; 27:1014-21. [PMID: 16338003 DOI: 10.1016/j.placenta.2005.10.009] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/04/2005] [Revised: 10/19/2005] [Accepted: 10/20/2005] [Indexed: 12/27/2022]
Abstract
The extracellular matrix protein fibulin-1 (FBLN1) is an important component of blood vessel walls, as shown by the lethality of mice with homozygous targeted deletion of the Fbln1 gene. Here, we show that a murine placental overgrowth phenotype is associated with elevated Fbln1 transcript levels, suggesting that the gene and its product have a functional role in placentation. Fbln1 exhibits a specific expression pattern in the mouse placenta. Transcripts could not be detected prior to day 12. In subsequent stages, Fbln1 was expressed strongly in the spongiotrophoblast. Other sites of expression were endothelia of large fetal blood vessels, a tissue type reported to not express this gene. In addition, a subset of giant cells expressed the gene. This giant cell specific expression was strongly increased in hyperplastic placentas. Analysis of the placentation in fibulin null mice did not show any abnormality. Attempts to rescue the placental phenotypes of a congenic model of interspecies hybrid placental dysplasia (IHPD) by normalizing expression of Fbln1 proved that Fbln1 alone is not the key cause of phenotypes in these models of placental hyperplasia.
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Affiliation(s)
- U Singh
- Department of Development and Genetics, Evolutionary Biology Center, Uppsala University, Norbyvägen 18A, SE-75236 Uppsala, Sweden
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Nakamoto T, Okada H, Nakajima T, Ikuta A, Yasuda K, Kanzaki H. Progesterone induces the fibulin-1 expression in human endometrial stromal cells. Hum Reprod 2005; 20:1447-55. [PMID: 15774544 DOI: 10.1093/humrep/deh841] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [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: 01/06/2023] Open
Abstract
BACKGROUND By using microarray analysis with human endometrial stromal cells (ESCs), we previously reported that the mRNA for fibulin-1, an extracellular matrix as well as a plasma glycoprotein, is up-regulated by progesterone. In the present study, we tried to clarify the spatial and temporal regulation mechanism of fibulin-1 in the human endometrium. METHODS AND RESULTS Quantitative analysis with real-time PCR experiments on human endometrial tissues showed significantly higher fibulin-1 mRNA expressions in secretory phase endometria than in proliferative phase. Immunohistochemical studies revealed that the fibulin-1 protein is expressed in the glandular epithelium in proliferative phase endometria, and that expression switched to the stroma in secretory phase endometria. In culture experiments with ESCs, a significant increase of fibulin-1 mRNA expression was observed in cells treated with 6 alpha-methyl-17 alpha-hydroxy-progesterone acetate (MPA) or 8 bromoadenosine 3':5'-cyclic monophosphate (8-Br-cAMP). MPA stimulated the fibulin-1 mRNA expression in a dose-dependent manner, and a progesterone antagonist, RU-486, inhibited the stimulatory effect almost completely. By contrast, beta-estradiol alone did not increase the fibulin-1 mRNA expression. CONCLUSIONS These results suggest that fiblin-1 is an important molecule that mediates progesterone action in human ESC differentiation towards implantation.
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Affiliation(s)
- T Nakamoto
- Department of Obstetrics and Gynecology, Kansai Medical University, 10-15 Fumizono-cho, Moriguchi, Osaka, 570-8507, Japan.
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Haendler B, Yamanouchi H, Lessey BA, Chwalisz K, Hess-Stumpp H. Cycle-dependent endometrial expression and hormonal regulation of thefibulin-1gene. Mol Reprod Dev 2004; 68:279-87. [PMID: 15112320 DOI: 10.1002/mrd.20079] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [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: 12/11/2022]
Abstract
Fibulin-1 is a secreted protein associated with elastic matrix fibres and basement membranes. It plays a role in stabilizing blood vessels and can also regulate cell motility and invasiveness. We studied the regulation of the fibulin-1 gene in the rat and human endometrium, an organ where cyclic tissue remodeling and angiogenesis take place. The rat fibulin-1C and -1D-specific DNA sequences were first identified and a comparison of the deduced amino acid sequence with the mouse and human counterparts showed a very strong conservation. The exon-intron structure was also maintained. Primers were derived for RT-PCR analysis of fibulin-1 expression in rat endometrium. The highest levels of fibulin-1C and -1D transcripts were measured at metestrous and diestrous, and in early pregnancy at day 3 post-coitum. In vivo studies showed stimulation of endometrial fibulin-1D expression after estrogen application, an effect prevented by parallel treatment with progesterone. Analysis of human endometrial tissues indicated that the fibulin-1D transcript levels were higher during the mid-secretory phase than during the proliferative and early secretory phases. Cultured human endometrial stromal cells treated with progesterone responded with a dramatic increase of fibulin-1 protein expression. This was enhanced by parallel treatment with epidermal growth factor and prevented by application of the antiprogestin RU486. Altogether the results show a cycle-dependent regulation of endometrial fibulin-1 expression controlled by both progesterone and estrogen. Based on its implication in tissue remodeling and angiogenesis, fibulin-1 may play an important role in endometrial receptivity for embryo implantation.
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9
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Abstract
Fibulins are a family of five extracellular glycoproteins found in a variety of tissues in association with diverse supramolecular structures, including elastic fibers, basement membrane networks, fibronectin microfibrils, and proteoglycan aggregates. Studies of the developmental expression patterns have indicated that several fibulins are prominently expressed at sites of epithelial-mesenchymal transformations during embryogenesis; among these sites, the cardiovascular system has been analyzed in more detail. Gene targeting of fibulins in mice has provided important insights into their biological roles, and has led to the identification of gene mutations in a congenital disorder of humans, cutis laxa. Genetic linkage and molecular studies have also associated several fibulin genes with various human heritable disorders that affect a wide range of organs, including limb, eye, blood, and arteries. In this review, we discuss the role of fibulins in development, with an emphasis on the cardiovascular system, and their involvement in human genetic disease.
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Affiliation(s)
- Mon-Li Chu
- Department of Dermatology and Cutaneous Biology, Jefferson Institute of Molecular Medicine, Thomas Jefferson University, Philadelphia, Pennsylvania, USA.
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10
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Toren A, Rozenfeld-Granot G, Heath KE, Amariglio N, Rocca B, Crosson J, Epstein CJ, Laghi F, Landolfi R, Carlsson LE, Argraves S, Bizzaro N, Moxey-Mims M, Brok-Simoni F, Martignetti JA, Greinacher A, Rechavi G. MYH9 spectrum of autosomal-dominant giant platelet syndromes: unexpected association with fibulin-1 variant-D inactivation. Am J Hematol 2003; 74:254-62. [PMID: 14635206 DOI: 10.1002/ajh.10425] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [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: 01/03/2023]
Abstract
The autosomal-dominant giant platelet syndromes (Fechtner, Epstein, and Sebastian platelet syndromes and May-Hegglin anomaly) represent a group of disorders characterized by variable degrees of macrothrombocytopenia with further combinations of neutrophil inclusion bodies and Alport-like syndrome manifestations, namely, deafness, renal disease, and eye abnormalities. The disease-causing gene of these giant platelet syndromes was previously mapped by us to chromosome 22. Following their successful mapping, these syndromes were shown to represent a broad phenotypic spectrum of disorders caused by different mutations in the nonmuscle myosin heavy chain 9 gene (MYH9). In this study, we examined the potential role of another gene, fibulin-1, encoding an extracellular matrix protein as a disease modifier. Eight unrelated families with autosomal-dominant giant platelet syndromes were studied for DNA sequence mutations and expression of the four fibulin-1 splice variants (A-D). A mutation in the splice acceptor site of fibulin-1 exon 19 was found in affected individuals of the Israeli Fechtner family, whereas no MYH9 mutations were identified. Unexpectedly, fibulin-1 variant D expression was absent in affected individuals from all eight families and coupled with expression of a putative antisense RNA. Transfection of the putative antisense RNA into H1299 cells abolished variant D expression. Based on the observation that only affected individuals lack variant D expression and demonstrate antisense RNA overexpression, we suggest that these autosomal-dominant giant platelet syndromes are associated, and may be modified, by aberrant antisense gene regulation of the fibulin-1 gene.
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Affiliation(s)
- Amos Toren
- Pediatric Hemato-Oncology Department and the Institute of Hematology, the Chaim Sheba Medical Center, Tel-Hashomer, Tel-Aviv University, Israel.
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11
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Abstract
Fibulins are a newly recognized family of extracellular matrix proteins. The five known members of the family share an elongated structure and many calcium-binding sites, owing to the presence of tandem arrays of epidermal growth factor-like domains. They have overlapping binding sites for several basement-membrane proteins, tropoelastin, fibrillin, fibronectin and proteoglycans, and they participate in diverse supramolecular structures. New insights into their biological roles are now emerging from studies of transgenic mice and of some inherited human diseases.
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Affiliation(s)
- Rupert Timpl
- Laboratory of Protein Chemistry, Max Planck Institute for Biochemistry, D-82152 Martinsried, Germany.
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12
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Abstract
Fibulin-1 is a multifunctional extracellular protein involved in diverse biological processes including cardiovascular development, haemostasis and cancer. To investigate the transcriptional regulation of the gene encoding fibulin-1 we cloned and analysed about 4.0 kb of the 5'-flanking regions of both the human and mouse fibulin-1 genes. The human and mouse fibulin-1 promoters share little sequence similarity except for a short region of approx. 150-170 bp immediately upstream of the translation start site. The conserved region contains a TATA-like sequence (ATAATT) and multiple consensus binding sites for Sp1 and activator protein 2 (AP-2). That the short conserved region in each gene confers basal promoter activity is demonstrated by transient transfections of promoter deletion constructs for both the human and mouse genes into cells that express fibulin-1 constitutively. Co-transfections of promoter constructs with expression plasmids for Sp1, Sp3 and Sp4 into Drosophila SL2 cells indicate that Sp1 and Sp3 are essential for transcriptional activation and that these two factors act synergistically. Electrophoretic mobility-shift assays show that Sp1 and Sp3, but not AP-2, bind to the basal promoter of the human fibulin-1 gene. The results demonstrate the functional importance of Sp1 and Sp3 in regulating the expression of the fibulin-1 gene.
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Affiliation(s)
- Mirco Castoldi
- Department of Dermatology and Cutaneous Biology, Thomas Jefferson University, 233 South 10th Street, Philadelphia, PA 19107, U.S.A
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Moll F, Katsaros D, Lazennec G, Hellio N, Roger P, Giacalone PL, Chalbos D, Maudelonde T, Rochefort H, Pujol P. Estrogen induction and overexpression of fibulin-1C mRNA in ovarian cancer cells. Oncogene 2002; 21:1097-107. [PMID: 11850827 DOI: 10.1038/sj.onc.1205171] [Citation(s) in RCA: 83] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2001] [Revised: 10/26/2001] [Accepted: 11/07/2001] [Indexed: 01/03/2023]
Abstract
Fibulin-1 is an extracellular matrix protein induced by estradiol in estrogen receptor (ER) positive ovarian cancer cell lines. Alternative splicing of fibulin-1 mRNA results in four different variants named A, B, C and D that may have distinct biological functions. We studied the relative expression of fibulin-1 mRNA variants and their estrogen regulation in human ovarian cancer cells. In ovarian tissues and cancer cell lines, fibulin-1C and -1D are the predominant forms, whereas fibulin-1A and -1B are weakly expressed. We developed a competitive PCR assay based on coamplification of fibulin-1C and -1D to study the relative expression of these fibulin-1 variants in human ovarian samples. In ovarian cancer cell lines and ovarian cancer samples, there was a marked increase in the fibulin-1C:1D and fibulin-1C:HPRT mRNA ratios as compared to normal ovaries. In the BG1 estrogen receptor positive ovarian cancer cell line, fibulin-1C mRNA was induced by estradiol in a dose- and time-dependent manner. Since others and we have previously shown an increased expression of ERalpha as compared to ERbeta in ovarian cancer cells, we investigated whether ERalpha or ERbeta is involved in this induction. For this aim, MDA-MB-231 breast cancer cell line, which expresses both low basal levels of ERs and fibulin-1, was infected with recombinant ERalpha or ERbeta encoding adenovirus and treated with estradiol. Fibulin-1C was induced by estradiol in ERalpha- but not ERbeta-infected cells, suggesting that fibulin-1C induction is mediated through ERalpha. In ovarian tumors, a trend towards a correlation between fibulin-1C and ERalpha expression levels was noted. In conclusion, this study showed an increased fibulin-1C:-1D mRNA ratio in ovarian cancer cells as compared to normal ovaries. This finding suggests that the C variant may be involved in ovarian carcinogenesis. Fibulin-1C overexpression may thus be a clue for the understanding of a putative role of estrogens in ERalpha promoted ovarian tumor progression.
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Affiliation(s)
- Frederic Moll
- Unité INSERM 540, 60 rue de Navacelles, 34095 Montpellier, France
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Kostka G, Giltay R, Bloch W, Addicks K, Timpl R, Fässler R, Chu ML. Perinatal lethality and endothelial cell abnormalities in several vessel compartments of fibulin-1-deficient mice. Mol Cell Biol 2001; 21:7025-34. [PMID: 11564885 PMCID: PMC99878 DOI: 10.1128/mcb.21.20.7025-7034.2001] [Citation(s) in RCA: 127] [Impact Index Per Article: 5.5] [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] Open
Abstract
The extracellular matrix protein fibulin-1 is a distinct component of vessel walls and can be associated with other ligands present in basement membranes, microfibrils, and elastic fibers. Its biological role was investigated by the targeted inactivation of the fibulin-1 gene in mice. This led to massive hemorrhages in several tissues starting at midgestation, ultimately resulting in the death of almost all homozygous embryos upon birth. Histological analysis demonstrated dilation and ruptures in the endothelial lining of various small vessels but not in that of larger vessels. Kidneys displayed a distinct malformation of glomeruli and disorganization of podocytes. A delayed development of lung alveoli suggested impairment in lung inflation. Immunohistology demonstrated the absence of fibulin-1 in its typical localizations but no aberrant patterns for several other extracellular matrix proteins. Electron microscopy revealed intact basement membranes but very irregular cytoplasmic processes of capillary endothelial cells in the organs that were most severely affected. Absence of fibulin-1 caused considerable blood loss but did not compromise blood clotting. The data indicate a strong but restricted abnormality in some endothelial compartments which, together with some kidney and lung defects, may be responsible for early death.
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Affiliation(s)
- G Kostka
- Max-Planck-Institut für Biochemie, D-82152 Martinsried, Germany
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15
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Abstract
Fibulin-2, an extracellular matrix protein containing tandem arrays of calcium-binding epidermal growth factor-like motifs, is present in the basement membrane and stroma of many tissues. Its expression pattern suggested an essential role in organogenesis, particularly in embryonic heart development. In this study, we cloned the extreme 5' end of the mouse fibulin-2 cDNA, isolated phage and cosmid clones encoding the entire gene, and functionally characterized the promoter. The gene was found to consist of 18 exons spanning 55 kb of DNA. The exon-intron organization reflected the modular structure of the protein. Exon 9 was subjected to alternative splicing. All splice junctions conformed to the GT/AG rule, except that GC instead of GT was found in the splice donor site of exon 4. The gene lacked TATA and CAAT boxes but contained an initiator element (Inr) and several consensus Sp1 binding sites surrounding the transcription start sites. By transient transfection of promoter deletion constructs, a 0.46-kb region containing the clustered Sp1 sites was found to confer a high promoter activity.
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Affiliation(s)
- S Grässel
- Department of Dermatology and Cutaneous Biology and Department of Biochemistry and Molecular Pharmacology, Jefferson Institute of Molecular Medicine, Thomas Jefferson University, PA, USA
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