Research Joseph Merregaert

Abstract

The extracellular matrix protein 1 (ECM1) was first identified in our laboratory of Molecular Biotechnology (UA) in 1994. From experimental work from our group and others it has been shown that ECM1 is involved in photoageing as well as in chronological ageing. The aims of this project is to evaluate the role of ECM1 as potential photo-protective agent (internal sunscreen) and anti-ageing agent using a skin equivalent model and a transgenic mouse model (Ecm1 +/- heterozygotes and Ecm1 overexpressing mice).

Researcher(s)

• Promoter: Merregaert Joseph

Research team(s)

Project type(s)

• Research Project

Abstract

The Transgenic mice Service Facility is centered on several aspects of Mouse transgenesis and is operational in the Specific Pathogen Free facility of the Mouse housing facility of the University of Antwerp ¿ CDE: production of genetically modified mice via pronuclear injections, production of knock-out ands knock-in clones via embryonic stem cells, re-derivation of non-SPF mice and cryopreservation van important mouse lines. At the end of 2007 the TgSF activities were stopped.

Researcher(s)

• Promoter: Van Broeckhoven Christine
• Co-promoter: Merregaert Joseph
• Co-promoter: Snyders Dirk

Research team(s)

Project type(s)

• Research Project

Abstract

Study the biological role of ECM1 and caspase-14 using skin equivalent models. Determine the specific protein binding partners of ECM1 in human skin. Study the role of ECM1 as inducer of the NF-kB signalling pathway. Identification of soluble ECM1b inducing factor(s) produced by dermal fibroblasts. Development of a mouse model for lipoid proteinosis and caspase-14. Identification of caspase-14 substrates. Identification of the caspase-14-activating factor.

Researcher(s)

• Promoter: Merregaert Joseph

Research team(s)

Project type(s)

• Research Project

Abstract

Researcher(s)

• Promoter: Merregaert Joseph
• Fellow: Sercu Sandy

Research team(s)

Project type(s)

• Research Project

Abstract

The significance of the extracellular protein 1 (ECM1) in human biology has been highlighted by the identification of six different homozygous loss-of-function mutations wich causes the rare skin disorder Lipoid Proteinoses (LP). However, the pathophysiology underlying this disease is still unknown. The main aim of this project is the determination of the biological function of ECM1 in skin development using an in vitro skin equivalent model as well as the generation of an inducible epidermic specific mouse model to recapitulate the human LP phenotype.

Researcher(s)

• Promoter: Merregaert Joseph
• Fellow: Sercu Sandy

Research team(s)

Project type(s)

• Research Project

Abstract

Chondrolectin (Chodl) is a novel type Ia transmembrane protein homologous to the C-type lectins that is predominantly expressed in different embryonic stages and skeletal muscle tissue. The biological function of Chondrolectin is unknown. The putative function will be studied by in vivo and in vitro experiments. Knock out mice will be generated to study the function in vivo while in vitro the putative extra- and intracellular ligands will resp. be identified by Yeast Surface Display (YSD) and the Sos Recruitment System (SRS).

Researcher(s)

• Promoter: Merregaert Joseph
• Fellow: Claessens An

Research team(s)

Project type(s)

• Research Project

Abstract

This network proposal has as major theme the molecular genetics and cell biology of human inherited disorders. This network groups 11 excellent research laboratories at the University of Antwerp active in molecular genetics of diseases such as Alzheimer dementia, psychiatric disorders, mental retardation, peripheral neuropathies, hearing impairment and bone disorders. The availability of the human genome sequence will not only provide the molecular geneticists new tools to accelerate their research topics (such as bioinformatics, SNPs, etc.), but also lead to functional studies of the respective disease causing genes. The post-genome era will therefore need the integration of high-throughput techniques and bio-informatics, but also collaboration with excellent cell biology laboratories in the network located at other Belgian universities.

Researcher(s)

• Promoter: Van Broeckhoven Christine
• Co-promoter: De Jonghe Peter
• Co-promoter: Merregaert Joseph
• Co-promoter: Snyders Dirk
• Co-promoter: Timmerman Vincent

Research team(s)

Project type(s)

• Research Project

Abstract

Itm2a is a gene isolated from mandibular condyles of prenatal mice (Deleersnijder et al., 1996, J.Biol.Chem. ,271,19475-19482) and coding for a type II integral membrane protein which is expressed during the early stages of endochondral bone formation. The goal of this project is to elucidate the biological function of Itm2a by means of: Inactivation of Itm2a through homologous recombination in embryonic stem cells; Overexpression of Itm2a in chondrocytes using a collagen type II promotor/enhancer; To study in vitro the effect of overexpression in chondrocytic cell lines.

Researcher(s)

• Promoter: Merregaert Joseph
• Fellow: Van Den Plas Dave

Research team(s)

Project type(s)

• Research Project

Abstract

The Itm2-protein family consists of three members, Itm2A,Itm2B and ItmC. They belong to a novel family of type II transmembrane proteins. The biological function of the family members is at present unknown.The cDNA sequence and the deduced amino acid sequence don't show any homology with available sequences in the public databanks and as a consequence don't give a clue about the function. Therefore transgene technolgoy (Itm2b/c) will be used to elucidate their putative function. On the other hand the SRS recruitment system as well as the chimer receptor system will be used to identify putative extra and intracellular proteinbinding partners.

Researcher(s)

• Promoter: Merregaert Joseph
• Fellow: Goossens Tim

Research team(s)

Project type(s)

• Research Project

Abstract

The main goal of this project is to inactivate the Ecm1 gene in the mouse by homologous recombination. In embryonic stem cells (ES-cells) a part of the Ecm1 gene will be replaced by a ?-galactosidase expression cassette. In animals heterozygous for this locus the expression pattern of Ecm1 will be studied by histoenzymatic staining. On the other hand, homozygous animals will enable us to study, in detail, the in vivo function of the Ecm1gene. To circumvent possible problems like embryonic lethality or infertility of the females due to haploinsufficiency, a second vector will be constructed in parallel which uses the Cre-recombinase LoxP system. This will allow us to obtain a 'tissue-specific' knock out.

Researcher(s)

• Promoter: Merregaert Joseph
• Fellow: Liekens Joeri

Research team(s)

Project type(s)

• Research Project

Abstract

The aim of the project is to establish a centralised facility for transgenesis within the University of Antwerp. This facility will be responsible for the transgenesis and gene targeting of ES cells, the generation of animal models and the in vitro culture work of genetically modified non-differentiated cells ( ES cells) and differentiated cells. The transgene technology will be applied in the functional studies of: Genes involved in osteo/chondrogenic differentiation (Ecm1,Itm2a); Genes involved in the pathogenesis of affective disorders; Genes coding for voltage-gated K+ channels .

Researcher(s)

• Promoter: Merregaert Joseph
• Co-promoter: Snyders Dirk
• Co-promoter: Van Broeckhoven Christine

Research team(s)

Project type(s)

• Research Project

Abstract

In order to study the process of bone formation one need a way to monitor the degree and progress of cellular differentiation leading to osteogenesis.Therefore, the aim of this project is to analyse pattern of gene expression at the onset of osteogenesis and identify genes that could be used for this process. The search for markers proceeds by two different approaches. One is subtractive hybridization with material from undifferentiated cells as a driver and material from cells that just entered osteogenesis as a target. The second approach is done using Differential Display technique (DD-RT-PCR).

Researcher(s)

• Promoter: Merregaert Joseph

Research team(s)

Project type(s)

• Research Project

Abstract

Itm2a is a gene isolated from mandibular condyles of prenatal mice (Deleersnijder et al., 1996, J.Biol.Chem. ,271,19475-19482) and coding for a type II integral membrane protein which is expressed during the early stages of endochondral bone formation. The goal of this project is to elucidate the biological function of Itm2a by means of: Inactivation of Itm2a through homologous recombination in embryonic stem cells; Overexpression of Itm2a in chondrocytes using a collagen type II promotor/enhancer; To study in vitro the effect of overexpression in chondrocytic cell lines.

Researcher(s)

• Promoter: Merregaert Joseph
• Fellow: Van Den Plas Dave

Research team(s)

Project type(s)

• Research Project

Abstract

The network investigates the structure, function and expression-regulation of matrixcomponents, adhesion molecules and morphogens (collagens, laminins, FGFs, Wnts, BMPs...); the enzymes and enzyme-inhibitors that are responsible for the controlled assembly and turnover of these molecules (MMPS, serine-proteases, TIMPS, serpins...); cognate cell-surface receptors (cadherins, integrins, syndecans, glypicans, receptor kinases...); the connections of these receptors with the cytoskeleton and intracellular signaling pathways (catenins, syntenins, SMADS); the effects of cell-cell and cell-matrix interactions on cell behavior and differentiation (morphotype, motility, invasion, gene expression); the relevance of these pathways for embryonic development (vasculogenesis, skeletogenesis...); the relevance of these pathways for genetic and acquired disease (dysmorphology syndromes, malignancy..).

Researcher(s)

• Promoter: Merregaert Joseph

Research team(s)

Project type(s)

• Research Project

Abstract

The main goal of this project is to inactivate the Ecm1 gene in the mouse by homologous recombination. In embryonic stem cells (ES-cells) a part of the Ecm1 gene will be replaced by a ?-galactosidase expression cassette. In animals heterozygous for this locus the expression pattern of Ecm1 will be studied by histoenzymatic staining. On the other hand, homozygous animals will enable us to study, in detail, the in vivo function of the Ecm1gene. To circumvent possible problems like embryonic lethality or infertility of the females due to haploinsufficiency, a second vector will be constructed in parallel which uses the Cre-recombinase LoxP system. This will allow us to obtain a 'tissue-specific' knock out.

Researcher(s)

• Promoter: Merregaert Joseph
• Fellow: Liekens Joeri

Research team(s)

Project type(s)

• Research Project

Abstract

The biological function of the Ecm1 gene is still unknown. The Ecm 1 mRNA or its deduced amino acid sequence lacks any similarities to sequences making it difficult to deduce any putative functional role for the protein. Therefore, and because our studies on ECM 1 are relevant for important embryonic, physiological and pathological processen, we have chosen in this project to inactivate the ECM 1 gene in the mouse ('knock-out''). In addition the effect of recombinant ECM.1 protein on angiogenesis will be studied in an in vitro culture system.

Researcher(s)

• Promoter: Merregaert Joseph

Research team(s)

Project type(s)

• Research Project

Abstract

The biological function of the Ecm 1 gene is still unknown, The Ecml mRNA or its deduced amino acid sequence lacks any similarities to sequences deposit in databanks, making it difficult to deduce any putative function for the Ecml protein. Therefore, and because our studies on Ecml are relevant for important embryonic, physiological and pathological processen, we have chosen in this project to inactivate the Ecm 1 gene in the mouse (knock-out). In addtition the effect of recombinant Ecm 1 protein on angiogensis will be studied.

Researcher(s)

• Promoter: Merregaert Joseph

Research team(s)

Project type(s)

• Research Project

Abstract

In order to study the process of bone formation one need a way to monitor the degree and progress of cellular differentiation leading to osteogenesis.Therefore, the aim of this project is to analyse pattern of gene expression at the onset of osteogenesis and identify genes that could be used for this process. The search for markers proceeds by two different approaches. One is subtractive hybridization with material from undifferentiated cells as a driver and material from cells that just entered osteogenesis as a target. The second approach is done using Differential Display technique (DD-RT-PCR).

Researcher(s)

• Promoter: Merregaert Joseph

Research team(s)

Project type(s)

• Research Project

Abstract

The aim of this project is to molecular clone a breakpoint on 11q13 which has been identified in a B-cel non Hodgkins lymphoma patient. This would allow us to isolate the cancergenes involved in this particular chromosomal translocation. Their genetic organisation will be studied, the gene regulation as well as the encoded protein structure. This will enable us to understand the molecular mechanisms underlying the generation of this 11q13 aberation.

Researcher(s)

• Promoter: Merregaert Joseph

Research team(s)

Project type(s)

• Research Project

Abstract

The ultimate goal of this project is to identify preosteoblastic-specific, clinically usesful markers. Therefor, we use the mandibular condyle of neonatal mouse as a model system to study the onset of bone formation. Genes upregulated at the onset of bone differentiation are isolated using the methodology of subtractive hybridization. Subsequently, candidate marker genes are further analysed by sequence analysis, in situ hybridization and immunohistology.

Researcher(s)

• Promoter: Merregaert Joseph

Research team(s)

Project type(s)

• Research Project

Abstract

Differentiation of mesenchymal cells in the osteogenic lineage proceeds in different steps. Specific growth-/differentiation factors are involved. The objectives are to define at the molecular level the genes involved in the earliest steps of the osteogenic differentiation pathway.

Researcher(s)

• Promoter: Merregaert Joseph
• Fellow: Pittois Karen

Research team(s)

Project type(s)

• Research Project

Abstract

The goal of our project is to isolate markers that are characteristic for the early stages of the cascade of bone formation. In order to identify differentially regulated genes, we propose to improve the method fo subtractive analysis and PCR-display. As modelsystem to study in vitro bone differentiation we have chosen for organ cultures of mandibular condyles and the osteogenic stromal cell line MN7.

Researcher(s)

• Promoter: Merregaert Joseph

Research team(s)

Project type(s)

• Research Project

Abstract

Goals of the research : molecular kloning, structure determination and chromosomal localisation of the fox-c-gene en his messenger molecules; procaryotic expression of the c-fox-cDNA, preparation of the anti-serum; cellular localisation of the c-fox geneproduct.

Researcher(s)

• Promoter: Merregaert Joseph

Research team(s)

Project type(s)

• Research Project

Abstract

Goals of the research : molecular kloning, structure determination and chromosomal localisation of the fox-c-gene en his messenger molecules; procaryotic expression of the c-fox-cDNA, preparation of the anti-serum; cellular localisation of the c-fox geneproduct.

Researcher(s)

• Promoter: Merregaert Joseph

Research team(s)

Project type(s)

• Research Project

Abstract

Mutations of the p53 tumorsupprossorgene are involved in different human cancers. The introduction of the wild type p53 gene in p53 deficient osteosarcoma cells leads to revertants, losing their malignant phenotype. The suppression of the malignant phenotype at the genetic level will be studied by subtractive hybridisation procedures.

Researcher(s)

• Promoter: Merregaert Joseph
• Fellow: Smits Patrick J M

Research team(s)

Project type(s)

• Research Project

Abstract

Differentiation of mesenchymal cells in the osteogenic lineage proceeds in different steps. Specific growth-/differentiation factors are involved. The objectives are to define at the molecular level the genes involved in the earliest steps of the osteogenic differentiation pathway.

Researcher(s)

• Promoter: Merregaert Joseph
• Fellow: Pittois Karen

Research team(s)

Project type(s)

• Research Project

Abstract

The fau gen is the cellular homolog of the fox sequenties in Finkel-Biskis-Reilly murine sarcoma virus (FBR-MuSV). It encodes a fusion protein, for 55% homologous to ubiquitine, while the carboxy-terminal end is, S30, a ribosomal protein of the small ribosomal subunit. The chromosomal mapping of one Fau locus was located on human chromosome 11q13.

Researcher(s)

• Promoter: Merregaert Joseph

Research team(s)

Project type(s)

• Research Project

Abstract

The fau gene is the cellular homolog of the fox sequenties in Finkel-Biskis-Reilly murine sarcoma virus (FBR-MuSV). It encodes a fusion protein, for 55% homologous to ubiquitine, while the carboxy-terminal end is, S30, a ribosomal protein of the small ribosomal subunit. The chromosomal mapping of one Fau locus was located on human chromosome 11q13.

Researcher(s)

• Promoter: Merregaert Joseph

Research team(s)

Project type(s)

• Research Project

Abstract

The Finkel-Biskis-Reilly murine sarcomavirus (FBR-MuSV) is an osteosarcoma inducing retrovirus which has transduced two cellular sequences, fos and fox. The primary structure of the mouse c-fox gene will be elucidated with nucleotide sequence analysis and the regulatory region will be characterized

Researcher(s)

• Promoter: Merregaert Joseph

Research team(s)

Project type(s)

• Research Project

Abstract

Differentiation of mesenchymal cells in the osteogenic lineage proceeds in different steps. Specific growth-/differentiation factors are involved. The objectives are to define at the molecular level the genes involved in the earliest steps of the osteogenic differentiation pathway.

Researcher(s)

• Promoter: Merregaert Joseph
• Fellow: Pittois Karen

Research team(s)

Project type(s)

• Research Project

Abstract

Using overlapping YAC clones, a physical map of the human chromosome 11q13 region will be established. The identification and isolation of genes is the result of a combination of : identification of CpG-islands, Zoo-blots, Northern blots, "in vivo" recombinant and the exon trapping method.

Researcher(s)

• Promoter: Merregaert Joseph

Research team(s)

Project type(s)

• Research Project

Abstract

Mutations of the p53 tumorsupprossorgene are involved in different human cancers. The introduction of the wild type p53 gene in p53 deficient osteosarcoma cells leads to revertants, losing their malignant phenotype. The suppression of the malignant phenotype at the genetic level will be studied by subtractive hybridisation procedures.

Researcher(s)

• Promoter: Merregaert Joseph
• Fellow: Smits Patrick J M

Research team(s)

Project type(s)

• Research Project

Abstract

This research project is an integrated, multidisciplinary approach to the isolation and characterization of growth and differentiation factors from conditioned media of cells in order to determine the factors which are involved in the interaction of - astrocytes with other cells of brain tissue - osteoblast and osteoclast in bone tissue - growth regulators in transgenic plant cells.

Researcher(s)

• Promoter: Merregaert Joseph

Research team(s)

Project type(s)

• Research Project

Abstract

The Finkel-Biskis-Reilly murine sarcomavirus (FBR-MuSV) is an osteosarcoma inducing retrovirus which has transduced two cellular sequences, fos and fox. The primary structure of the mouse c-fox gene will be elucidated with nucleotide sequence analysis and the regulatory region will be characterized

Researcher(s)

• Promoter: Merregaert Joseph

Research team(s)

Project type(s)

• Research Project

Abstract

Mutations of the p53 tumorsupprossorgene are involved in different human cancers. The introduction of the wild type p53 gene in p53 deficient osteosarcoma cells leads to revertants, losing their malignant phenotype. The suppression of the malignant phenotype at the genetic level will be studied by subtractive hybridisation procedures.

Researcher(s)

• Promoter: Merregaert Joseph
• Fellow: Smits Patrick J M

Research team(s)

Project type(s)

• Research Project

Abstract

Mouse neonatal condyles undergo osteogenic differentiation within 1-2 weeks when cultured in vitro on collagen sponges. The aim of this project is to isolate, characterize and produce via gene cloning techniques the osteoregulatory factors that are active in this model system.

Researcher(s)

• Promoter: Merregaert Joseph

Research team(s)

Project type(s)

• Research Project

Abstract

This research project is an integrated, multidisciplinary approach to the isolation and characterization of growth and differentiation factors from conditioned media of cells in order to determine the factors which are involved in the interaction of - astrocytes with other cells of brain tissue - osteoblast and osteoclast in bone tissue - growth regulators in transgenic plant cells.

Researcher(s)

• Promoter: Merregaert Joseph
• Co-promoter: Clauwaert Julius
• Co-promoter: Slegers Herman

Research team(s)

Project type(s)

• Research Project

Abstract

The osteosarcoma inducing retrovium FBR-MuSV transduced 2 cellular genes of the mouse : fos and fox. The human version of the c-fox gen will be chromosomally mapped and sequenced to understand its regulation. Antibodies will be raised against the Fox protein to localise it within the cell and for functional analysis

Researcher(s)

• Promoter: Merregaert Joseph

Research team(s)

Project type(s)

• Research Project

Abstract

Researcher(s)

• Promoter: Merregaert Joseph

Research team(s)

Project type(s)

• Research Project

Abstract

Researcher(s)

• Promoter: Merregaert Joseph
• Fellow: Mathieu Eric

Research team(s)

Project type(s)

• Research Project

Abstract

Researcher(s)

• Promoter: Merregaert Joseph
• Fellow: Mathieu Eric

Research team(s)

Project type(s)

• Research Project

Abstract

In addition to v-fos, the mouse osteosascoma inducing retrovirus FBR-MuSV has transduced cellular sequences called c-fau. The mandibular condyle of perinatal mouse is used to study the influence of v-fos FBR-MuSV on tumorigenisis and the contribution of v-fau on bone differentiation "in vitro"

Researcher(s)

• Promoter: Merregaert Joseph

Research team(s)

Project type(s)

• Research Project