The Experts below are selected from a list of 765 Experts worldwide ranked by ideXlab platform
Matthias Wiens - One of the best experts on this subject based on the ideXlab platform.
-
An evolutionary perspective on the role of mesencephalic astrocyte-derived neurotrophic factor (MANF): At the crossroads of poriferan innate immune and apoptotic pathways
Elsevier, 2017Co-Authors: Dayane Sereno, Werner E. G. Müller, Julia S Markl, Melanie Bausen, Tarek A. Elkhooly, Matthias WiensAbstract:The mesencephalic astrocyte-derived neurotrophic factor (MANF) belongs to a recently discovered family of neurotrophic factors. MANF can be secreted but is generally resident within the endoplasmic reticulum (ER) in neuronal and non-neuronal cells, where it is involved in the ER stress response with pro-survival effects. Here we report the discovery of the MANF homolog SDMANF in the sponge Suberites domuncula. The basal positioning of sponges (phylum Porifera) in the animal tree of life offers a unique vantage point on the early evolution of the metazoan-specific genetic toolkit and molecular pathways. Since sponges lack a conventional nervous system, SDMANF presents an enticing opportunity to investigate the evolutionary ancient role of these neurotrophic factors. SDMANF shares considerable sequence similarity with its metazoan homologs. It also comprises a putative protein binding domain with sequence similarities to the Bcl-2 family of apoptotic regulators. In Suberites, SDMANF is expressed in the vicinity of bacteriocytes, where it co-localizes with the toll-like receptor SDTLR. In transfected human cells, SDMANF was detected in both the organelle protein fraction and the cell culture medium. The intracellular SDMANF protein level was up-regulated in response to both a Golgi/ER transport inhibitor and bacterial lipopolysaccharides (LPS). Upon LPS challenge, transfected cells revealed a decreased caspase-3 activity and increased cell viability with no inducible Bax expression compared to the wild type. These results suggest a deep evolutionary original cytoprotective role of MANF, at the crossroads of innate immune and apoptotic pathways, of which a neurotrophic function might have arisen later in metazoan evolution
-
Primers used to quantify gene expression in Suberites domuncula using real-time PCR.
2014Co-Authors: Johan Gardères, Matthias Wiens, Werner E. G. Müller, Joël Henry, Benoit Bernay, Andrès Ritter, Céline Zatylny-gaudin, Gael Le PennecAbstract:Primers used to quantify gene expression in Suberites domuncula using real-time PCR.
-
nocturnin in the demosponge Suberites domuncula a potential circadian clock protein controlling glycogenin synthesis in sponges
Biochemical Journal, 2012Co-Authors: Xiaohong Wang, Matthias Wiens, Vladislav A Grebenjuk, Michael Korzhev, Ute Schlossmacher, Heinz C SchroderAbstract:Sponges are filter feeders that consume a large amount of energy to allow a controlled filtration of water through their aquiferous canal systems. It has been shown that primmorphs, three-dimensional cell aggregates prepared from the demosponge Suberites domuncula and cultured in vitro , change their morphology depending on the light supply. Upon exposure to light, primmorphs show a faster and stronger increase in DNA, protein and glycogen content compared with primmorphs that remain in the dark. The sponge genome contains nocturnin, a light/dark-controlled clock gene, the protein of which shares a high sequence similarity with the related molecule of higher metazoans. The sponge nocturnin protein was found showing a poly(A)-specific 3′-exoribonuclease activity. In addition, the cDNA of the glycogenin gene was identified for subsequent expression studies. Antibodies against nocturnin were raised and used in parallel with the cDNA to determine the regional expression of nocturnin in intact sponge specimens; the highest expression of nocturnin was seen in the epithelial layer around the aquiferous canals. Quantitative PCR analyses revealed that primmorphs after transfer from light to dark show a 10-fold increased expression in the nocturnin gene. In contrast, the expression level of glycogenin decreases in the dark by 3– 4-fold. Exposure of primmorphs to light causes a decrease in nocturnin transcripts and a concurrent increase in glycogenin transcripts. It was concluded that sponges are provided with the molecular circadian clock protein nocturnin that is highly expressed in the dark where it controls the stability of a key metabolic enzyme, glycogenin. Abbreviations: BMAL1, brain and muscle ARNT (aryl hydrocarbon receptor nuclear translocator)-like 1; CLOCK, circadian locomotor output cycles kaput; CRY, cryptochrome; Cy5, indodicarbocyanine; DAPI, 4′,6-diamidino-2-phenylindole; DIG, digoxigenin; GABA, γ-aminobutyric acid; hnRNA, heterogeneous nuclear RNA; ORF, open reading frame; Per, period; qRT–PCR, quantitative real-time reverse transcription PCR; Ror, retinoic acid-related orphan receptor; SDGAPDH, Suberites domuncula glycerol 3-phosphate dehydrogenase; SDGYG, S. domuncula glycogenin; SDNOC, S. domuncula nocturnin
-
chemical mimicry hierarchical 1d tio2 zro2 core shell structures reminiscent of sponge spicules by the synergistic effect of silicatein α and silintaphin 1
Langmuir, 2011Co-Authors: Rute Andre, Matthias Wiens, Ute Kolb, Thorben Link, Muhammad Tahir, Florian D Jochum, Patrick Theato, Rudiger Berger, H. C. SchröderAbstract:In nature, mineralization of hard tissues occurs due to the synergistic effect of components present in the organic matrix of these tissues, with templating and catalytic effects. In Suberites domuncula, a well-studied example of the class of demosponges, silica formation is mediated and templated by an axial proteinaceous filament with silicatein-α, one of the main components. But so far, the effect of other organic constituents from the proteinaceous filament on the catalytic effect of silicatein-α has not been studied in detail. Here we describe the synthesis of core−shell TiO2@SiO2 and TiO2@ZrO2 nanofibers via grafting of silicatein-α onto a TiO2 nanowire backbone followed by a coassembly of silintaphin-1 through its specifically interacting domains. We show for the first time a linker-free, one-step funtionalization of metal oxides with silicatein-α using glutamate tag. In the presence of silintaphin-1 silicatein-α facilitates the formation of a dense layer of SiO2 or ZrO2 on the TiO2@protein backbon...
-
a cryptochrome based photosensory system in the siliceous sponge Suberites domuncula demospongiae
FEBS Journal, 2010Co-Authors: Xiaohong Wang, Heinz C Schroder, Dario Pisignano, Klaus Peter Jochum, Vladislav A Grebenjuk, Michael Korzhev, Julia S Markl, Matthias WiensAbstract:Based on the light-reactive behavior of siliceous sponges, their intriguing quartz glass-based spicular system and the existence of a light-generating luciferase [Muller WEG et al. (2009) Cell Mol Life Sci 66, 537–552], a protein potentially involved in light reception has been identified, cloned and recombinantly expressed from the demosponge Suberites domuncula. Its sequence displays two domains characteristic of cryptochrome, the N-terminal photolyase-related region and the C-terminal FAD-binding domain. The expression level of S. domuncula cryptochrome depends on animal’s exposure to light and is highest in tissue regions rich in siliceous spicules; in the dark, no cryptochrome transcripts/translational products are seen. From the experimental data, it is proposed that sponges might employ a luciferase-like protein, the spicular system and a cryptochrome as the light source, optical waveguide and photosensor, respectively.
Heinz C Schroder - One of the best experts on this subject based on the ideXlab platform.
-
nocturnin in the demosponge Suberites domuncula a potential circadian clock protein controlling glycogenin synthesis in sponges
Biochemical Journal, 2012Co-Authors: Xiaohong Wang, Matthias Wiens, Vladislav A Grebenjuk, Michael Korzhev, Ute Schlossmacher, Heinz C SchroderAbstract:Sponges are filter feeders that consume a large amount of energy to allow a controlled filtration of water through their aquiferous canal systems. It has been shown that primmorphs, three-dimensional cell aggregates prepared from the demosponge Suberites domuncula and cultured in vitro , change their morphology depending on the light supply. Upon exposure to light, primmorphs show a faster and stronger increase in DNA, protein and glycogen content compared with primmorphs that remain in the dark. The sponge genome contains nocturnin, a light/dark-controlled clock gene, the protein of which shares a high sequence similarity with the related molecule of higher metazoans. The sponge nocturnin protein was found showing a poly(A)-specific 3′-exoribonuclease activity. In addition, the cDNA of the glycogenin gene was identified for subsequent expression studies. Antibodies against nocturnin were raised and used in parallel with the cDNA to determine the regional expression of nocturnin in intact sponge specimens; the highest expression of nocturnin was seen in the epithelial layer around the aquiferous canals. Quantitative PCR analyses revealed that primmorphs after transfer from light to dark show a 10-fold increased expression in the nocturnin gene. In contrast, the expression level of glycogenin decreases in the dark by 3– 4-fold. Exposure of primmorphs to light causes a decrease in nocturnin transcripts and a concurrent increase in glycogenin transcripts. It was concluded that sponges are provided with the molecular circadian clock protein nocturnin that is highly expressed in the dark where it controls the stability of a key metabolic enzyme, glycogenin. Abbreviations: BMAL1, brain and muscle ARNT (aryl hydrocarbon receptor nuclear translocator)-like 1; CLOCK, circadian locomotor output cycles kaput; CRY, cryptochrome; Cy5, indodicarbocyanine; DAPI, 4′,6-diamidino-2-phenylindole; DIG, digoxigenin; GABA, γ-aminobutyric acid; hnRNA, heterogeneous nuclear RNA; ORF, open reading frame; Per, period; qRT–PCR, quantitative real-time reverse transcription PCR; Ror, retinoic acid-related orphan receptor; SDGAPDH, Suberites domuncula glycerol 3-phosphate dehydrogenase; SDGYG, S. domuncula glycogenin; SDNOC, S. domuncula nocturnin
-
a cryptochrome based photosensory system in the siliceous sponge Suberites domuncula demospongiae
FEBS Journal, 2010Co-Authors: Xiaohong Wang, Heinz C Schroder, Dario Pisignano, Klaus Peter Jochum, Vladislav A Grebenjuk, Michael Korzhev, Julia S Markl, Matthias WiensAbstract:Based on the light-reactive behavior of siliceous sponges, their intriguing quartz glass-based spicular system and the existence of a light-generating luciferase [Muller WEG et al. (2009) Cell Mol Life Sci 66, 537–552], a protein potentially involved in light reception has been identified, cloned and recombinantly expressed from the demosponge Suberites domuncula. Its sequence displays two domains characteristic of cryptochrome, the N-terminal photolyase-related region and the C-terminal FAD-binding domain. The expression level of S. domuncula cryptochrome depends on animal’s exposure to light and is highest in tissue regions rich in siliceous spicules; in the dark, no cryptochrome transcripts/translational products are seen. From the experimental data, it is proposed that sponges might employ a luciferase-like protein, the spicular system and a cryptochrome as the light source, optical waveguide and photosensor, respectively.
-
silicatein mediated incorporation of titanium into spicules from the demosponge Suberites domuncula
Cell and Tissue Research, 2010Co-Authors: Filipe Natalio, Wolfgang Tremel, Heinz C Schroder, Matthias Wiens, Xiaohong Wang, Enrico Mugnaioli, Muhammad Nawaz Tahir, Ute KolbAbstract:Primmorphs (a three-dimensional sponge primary cell culture system) have been revealed to be a cell/tissue nano-factory for the production of tailor-made hybrid nanostructures. Growth of primmorphs is stimulated by the presence of a titanium alkoxide precursor tolerating titania (TiO2) concentrations up to 250 μM. The presence and activity of silicatein in primmorphs has been analyzed by gel electrophoresis and Western blotting. Results of studies by scanning transmission electron microscopy with energy-dispersive X-ray spectroscopy have revealed silica and titania to be co-localized on nanosized spicules. Our findings suggest that the incorporation of titania into the nanosized spicule is enzymatically mediated via active silicatein in an orchestrated mechanism.
-
strombine dehydrogenase in the demosponge Suberites domuncula characterization and kinetic properties of the enzyme crucial for anaerobic metabolism
Comparative Biochemistry and Physiology B, 2009Co-Authors: Bruna Plese, Heinz C Schroder, David Brandt, Vladislav A Grebenjuk, Gerhard Wegener, Filipe NatalioAbstract:Previously, the cDNA and the respective gene for a presumed tauropine dehydrogenase (TaDH) from Suberites domuncula (GenBank accession nos. AM712888, AM712889) had been annotated. The conclusion that the sequences encode a TaDH had been inferred from the 68% identity with the TaDH protein from the marine demosponge Halichondria japonica. However, subsequent enzymatic assays shown here indicate that the presumed S. domuncula opine dehydrogenase is in fact a strombine dehydrogenase (StDH). The enzyme StDH is highly specific for glycine and is inhibited by an excess of the substrate pyruvate. Besides kinetic data, we report in this study also on the predicted tertiary and quaternary structure of the sponge StDH. It is concluded that the dimer (75 kDa) has a novel structure, distinguishing it from other known marine invertebrate OpDHs that exist as monomers.
-
histochemical and electron microscopic analysis of spiculogenesis in the demosponge Suberites domuncula
Journal of Histochemistry and Cytochemistry, 2006Co-Authors: Carsten Eckert, Heinz C Schroder, David Brandt, Sanja PerovicottstadtAbstract:The skeleton of demosponges is built of spicules consisting of biosilica. Using the primmorph system from Suberites domuncula, we demonstrate that silicatein, the biosilica-synthesizing enzyme, and silicase, the catabolic enzyme, are colocalized at the surface of growing spicules as well as in the axial filament located in the axial canal. It is assumed that these two enzymes are responsible for the deposition of biosilica. In search of additional potential structural molecules that might guide the mineralization process during spiculogenesis to species-specific spicules, electron microscopic studies with antibodies against galectin and silicatein were performed. These studies showed that silicatein forms a complex with galectin; the strings/bundles of this complex are intimately associated with the surface of the spicules and arranged concentrically around them. Collagen fibers are near the silactein/galectin complexes. The strings/bundles formed from silicatein/galectin display a lower degree of orientation than the collagen fibers arranged in a highly ordered pattern around the spicules. These data indicate that species-specific formation of spicules involves a network of (diffusible) regulatory factor(s) controlling enzymatic silica deposition; this mineralization process proceeds on a galectin/collagen organic matrix.
Isabel M. Müller - One of the best experts on this subject based on the ideXlab platform.
-
selenium affects biosilica formation in the demosponge Suberites domuncula
FEBS Journal, 2005Co-Authors: Alexandra Borejko, Anatoli Krasko, Isabel M. Müller, David Brandt, Bojan Hamer, Ronald Osinga, Hiroshi Ushijima, Cao Xupeng, Heinz C SchroderAbstract:Selenium is a trace element found in freshwater and the marine environment. We show that it plays a major role in spicule formation in the demosponge Suberites domuncula. If added to primmorphs, an in vitro sponge cell culture system, it stimulates the formation of siliceous spicules. Using differential display of transcripts, we demonstrate that, after a 72-h exposure of primmorphs to selenium, two genes are up-regulated; one codes for selenoprotein M and the other for a novel spicule-associated protein. The deduced protein sequence of selenoprotein M (14 kDa) shows characteristic features of metazoan selenoproteins. The spicule-associated protein (26 kDa) comprises six characteristic repeats of 20 amino acids, composed of 10 distinct hydrophobic regions (? 9 amino acids in length). Recombinant proteins were prepared, and antibodies were raised against these two proteins. Both were found to stain the central axial filament, which compri-ses the silicatein, as well as the surface of the spicules. In the presence of selenium, only the genes for selenoprotein M and spicule-associated protein are up-regulated, whereas the expression of the silicatein gene remains unchanged. Finally we show that, in the presence of selenium, larger silica aggregates are formed. We conclude that selenium has a stimulatory effect on the formation of siliceous spicules in sponges, and it may be involved in the enzymatic synthesis of biosilica components.
-
biosilica formation in spicules of the sponge Suberites domuncula synchronous expression of a gene cluster
Genomics, 2005Co-Authors: Heinz C Schroder, Vladislav A Grebenjuk, Sanja Perovicottstadt, Sylvia Engel, Isabel M. MüllerAbstract:The formation of spicules is a complicated morphogenetic process in sponges (phylum Porifera). The primmorph system was used to demonstrate that in the demosponge Suberites domuncula the synthesis of the siliceous spicules starts intracellularly and is dependent on the concentration of silicic acid. To understand spicule formation, a cluster of genes was isolated. In the center of this cluster is the silicatein gene, which codes for the enzyme that synthesizes spicules. This gene is flanked by an ankyrin repeat gene at one side and by a tumor necrosis factor receptor-associated factor and a protein kinase gene at the other side. All genes are strongly expressed in primmorphs and intact animals after exposure to silicic acid, and this expression is restricted to those areas where the spicule formation starts or where spicules are maintained in the animals. Our observations suggest that in S. domuncula a coordinated expression of physically linked genes is essential for the synthesis of the major skeletal elements.
-
molecular markers for germ cell differentiation in the demosponge Suberites domuncula
The International Journal of Developmental Biology, 2004Co-Authors: Sanja Perovicottstadt, Heinz C Schroder, Vera Gamulin, Helena Cetkovic, Michael Korzhev, Klaus Kropf, Claire Moss, Barbel Diehlseifert, Isabel M. MüllerAbstract:Sponges (phylum Porifera) are simple metazoans for which no molecular information on gametogenesis and larval development is available. To support the current study, it was confirmed by histology that oocytes and larvae were produced by the demosponge Suberites domuncula. Three genes/expressed products from S. domuncula whose expression correlated with sexual reproduction were identified and characterized (they are used here as marker genes): i) a receptor tyrosine kinase (RTK) with sequence similarity in the tyrosine kinase domain to fibroblast growth factor receptors; ii) the sex-determining protein FEM1 and iii) the sperm associated antigen (SAA) of triploblasts. Antibodies against the extracellular domain of the RTK specifically stained oocytes and larvae in S. domuncula tissue sections. Induction of these three genes was successful at elevated temperature, a factor which also promotes natural gametogenesis. In situ hybridization analyses revealed that FEM1 and SAA were expressed in those areas in which gametogenesis begins. Our results indicate that genes which play a role in sex determination may be present in Porifera.
-
differentiation capacity of epithelial cells in the sponge Suberites domuncula
Cell and Tissue Research, 2004Co-Authors: Heinz C Schroder, Renato Batel, Matthias Wiens, Sanja Perovicottstadt, Isabel M. MüllerAbstract:Sponges (phylum Porifera) represent the oldest metazoans. Their characteristic metazoan adhesion molecules and transcription factors enable them to establish a complex "Bauplan"; three major differentiated cell types (epithelial cells, skeletal cells/sclerocytes, and contractile cells) can be distinguished. Since no molecular markers are as yet available to distinguish these somatic cells or the corresponding embryonic cells from which they originate, we have selected the following three genes for their characterization: noggin (a signaling molecule in development), a caspase that encodes an apoptotic molecule, and silicatein. Silicatein is an enzyme that is involved in the synthesis of siliceous spicules and can hence be considered as a marker for scleroblasts. We have used the demosponge Suberites domuncula as a model system. During the hatching of the gemmules (asexual reproduction bodies) of S. domuncula, the expression of both noggin and caspase increases, whereas no transcripts for silicatein can be detected, irrespective of the presence of silicate or ferric iron (Fe3+) in the medium. In contrast, in adult specimens, silicate/Fe3+ cause an increased expression of these genes. In situ analysis has revealed that the first cells that express noggin, caspase, and silicatein lie in the epithelial layer of the pinacoderm. In a later phase, the noggin- and silicatein-positive cells migrate into the mesohyl, where they are found in association with spicules. Thus, the pinacoderm of sponges contains cells that have a differentiating capacity and from which somatic cells, such as skeletal cells/sclerocytes, derive.
-
emergence and disappearance of an immune molecule an antimicrobial lectin in basal metazoa a tachylectin related protein in the sponge Suberites domuncula
Journal of Biological Chemistry, 2003Co-Authors: Heinz C Schroder, Anatoli Krasko, Vera Gamulin, Narsinh L Thakur, Barbel Diehlseifert, Hiroshi Ushijima, Isabel M. MüllerAbstract:Sponges (phylum Porifera) represent the evolutionarily oldest metazoans that comprise already a complex immune system and are related to the crown taxa of the protostomians and the deuterostomians. Here, we demonstrate the existence of a tachylectin-related protein in the demosponge Suberites domuncula, termed Suberites lectin. The MAPK pathway was activated in response to lipopolysaccharide treatment of the three-dimensional cell aggregates, the primmorphs; this process was abolished by the monosaccharide D-GlcNAc. The cDNA encoding the S. domuncula lectin was identified and cloned; it comprises 238 amino acids (26 kDa) in the open reading frame. The deduced protein has one potential transmembrane region, three characteristic Cys residues, and six internal tandem repeats; it shares the highest sequence similarity with lectins from the horseshoe crab Tachypleus trunculus. The steady-state level of expression of the Suberites lectin rises in primmorphs in response to lipopolysaccharide, an effect that was prevented by co-incubation with D-GlcNAc. The natural sponge lectin was purified by affinity chromatography; it has a size of 27 kDa and displays antibacterial activity against the Gram-negative bacteria Escherichia coli and the Gram-positive bacteria Staphylococcus aureus. The putative protein, deduced from the cloned gene, is identical/similar to the purified natural protein, as demonstrated by immunological cross-reactivity with specific antibodies. We conclude that the S. domuncula lectin acts as an antibacterial molecule involved in immune defense against bacterial invaders.
Renato Batel - One of the best experts on this subject based on the ideXlab platform.
-
okadaic acid an apoptogenic toxin for symbiotic parasitic annelids in the demosponge Suberites domuncula
Applied and Environmental Microbiology, 2006Co-Authors: Heinz C Schroder, Matthias Wiens, Renate Steffen, Hans J Breter, Hiroshi Ushijima, Ernesto Fattorusso, Renato BatelAbstract:The role of okadaic acid (OA) in the defense system of the marine demosponge Suberites domuncula against symbiotic/parasitic annelids was examined. Bacteria within the mesohyl produced okadaic acid at concentrations between 32 ng/g and 58 ng/g of tissue (wet weight). By immunocytochemical methods and by use of antibodies against OA, we showed that the toxin was intracellularly stored in vesicles. Western blotting experiments demonstrated that OA also existed bound to a protein with a molecular weight of 35,000 which was tentatively identified as a galectin (by application of antigalectin antibodies). Annelids that are found in S. domuncula undergo apoptotic cell death. OA is one candidate inducer molecule of this process, since this toxin accumulated in these symbionts/parasites. Furthermore, we identified the cDNA encoding the multifunctional prosurvival molecule BAG-1 in S. domuncula; it undergoes strong expression in the presence of the annelid. Our data suggest that sponges use toxins (here, OA) produced from bacteria to eliminate metazoan symbionts/parasites by apoptosis.
-
differentiation capacity of epithelial cells in the sponge Suberites domuncula
Cell and Tissue Research, 2004Co-Authors: Heinz C Schroder, Renato Batel, Matthias Wiens, Sanja Perovicottstadt, Isabel M. MüllerAbstract:Sponges (phylum Porifera) represent the oldest metazoans. Their characteristic metazoan adhesion molecules and transcription factors enable them to establish a complex "Bauplan"; three major differentiated cell types (epithelial cells, skeletal cells/sclerocytes, and contractile cells) can be distinguished. Since no molecular markers are as yet available to distinguish these somatic cells or the corresponding embryonic cells from which they originate, we have selected the following three genes for their characterization: noggin (a signaling molecule in development), a caspase that encodes an apoptotic molecule, and silicatein. Silicatein is an enzyme that is involved in the synthesis of siliceous spicules and can hence be considered as a marker for scleroblasts. We have used the demosponge Suberites domuncula as a model system. During the hatching of the gemmules (asexual reproduction bodies) of S. domuncula, the expression of both noggin and caspase increases, whereas no transcripts for silicatein can be detected, irrespective of the presence of silicate or ferric iron (Fe3+) in the medium. In contrast, in adult specimens, silicate/Fe3+ cause an increased expression of these genes. In situ analysis has revealed that the first cells that express noggin, caspase, and silicatein lie in the epithelial layer of the pinacoderm. In a later phase, the noggin- and silicatein-positive cells migrate into the mesohyl, where they are found in association with spicules. Thus, the pinacoderm of sponges contains cells that have a differentiating capacity and from which somatic cells, such as skeletal cells/sclerocytes, derive.
-
okadaic acid a potential defense molecule for the sponge Suberites domuncula
Marine Biology, 2003Co-Authors: Matthias Wiens, H. C. Schröder, Renato Batel, Franz Brümmer, Renate Steffen, Barbel Diehlseifert, B Luckas, M Shokry, A Ammar, W. E. G. MüllerAbstract:Sponges are sessile filter feeders that are exposed to toxic compounds/xenobiotics and a huge number of diverse pro- and eukaryotic organisms occurring in the aqueous milieu. To cope with these threats, sponges have developed a variety of chemical and immunological defense systems. Among them are potent secondary metabolites or toxins. The demosponge Suberites domuncula contains the bioactive compound okadaic acid; concentrations of ≈50 ng/g (≈60 nM) of wet tissue have been quantified by LC/MS. In the present study, we sought to determine whether okadaic acid is beneficial for this sponge. Antibodies were raised against okadaic acid and used to localize this compound in situ. It could be demonstrated that the polyclonal antibodies/antiserum stained the sponge cells (endopinacocytes) which form the epithelium of the lacunae and the water channels. They also reacted with bacteria present in sponge tissue. Okadaic acid was found to augment the immune response of S. domuncula against the bacterial endotoxin lipopolysaccharide (LPS). If primmorphs, a special form of 3-D aggregates, are incubated with LPS at a concentration of 3 µg/ml, a reduction in the incorporation rate of [3H] phenylalanine is measured. In the presence of okadaic acid, this effect is measured already at a concentration of 1 µg/ml, suggesting that okadaic acid sensitizes this (immune) response. Okadaic acid is a known inhibitor of protein phosphatases which, as shown here, cause an increased phosphorylation of p38, a central kinase of the MAP kinase pathway; this may explain the sensitive response of the sponge cells to LPS. At higher concentrations, okadaic acid induces apoptosis, as was demonstrated here by a differential expression of the Bcl-2 homolog and the caspase gene. It is concluded that okadaic acid has two functions in the sponge; first, at low concentrations (<100 nM) a stimulation of the defense system against bacteria, and second, at concentrations above 500 nM, a differential effect on the pro-/anti-apoptotic genes.
-
the allograft inflamatory factor aif locus in seawater sponge Suberites domuncula
First croatian congress on molecular life sciences, 2002Co-Authors: Mauro Stifanic, Vladislav Grebenyuk, Werner E G Mueller, Renato BatelAbstract:AIF is a gene involved in the autoimmune response.The genomic locus of 28 kb in size was sequenced and here we report the current status of this work.
-
stimulation of protein collagen synthesis in sponge cells by a cardiac myotrophin related molecule from Suberites domuncula
The FASEB Journal, 2000Co-Authors: Heinz C Schroder, Anatoli Krasko, Renato Batel, Michael Kruse, Alexander Skorokhod, Sabine Pahler, Isabel M. MüllerAbstract:The body wall of sponges (Porifera), the lowest metazoan phylum, is formed by two epithelial cell layers of exopinacocytes and endopinacocytes, both of which are associated with collagen fibrils. Here we show that a myotrophin-like polypeptide from the sponge Suberites domuncula causes the expression of collagen in cells from the same sponge in vitro. The cDNA of the sponge myotrophin was isolated; the potential open reading frame of 360 nt encodes a 120 aa long protein (Mr of 12,837). The sequence SUBDOMYOL shares high similarity with the known metazoan myotrophin sequences. The expression of SUBDOMYOL is low in single cells but high after formation of primmorph aggregates as well as in intact animals. Recombinant myotrophin was found to stimulate protein synthesis by fivefold, as analyzed by incorporation studies using [3H] lysine. In addition, it is shown that after incubation of single cells with myotrophin, the primmorphs show an unusual elongated, oval-shaped appearance. It is demonstrated that in t...
W. E. G. Müller - One of the best experts on this subject based on the ideXlab platform.
-
MAP kinase cell signaling pathway as biomarker of environmental pollution in the sponge Suberites domuncula
Ecotoxicology, 2011Co-Authors: Alison Chatel, B. Hamer, W. E. G. Müller, H. Talarmin, H. C. Schröder, G DorangeAbstract:In the present study, we analyzed the effects of two major pollutants of the environment, tributyltin (TBT) and water-accommodated fraction (WAF) of diesel oil, on MAP kinase activation, apoptosis induction and DNA damage, in the marine sponge Suberites domuncula . Our results clearly demonstrated a differential activation of the MAPKs depending on the chemicals tested. TBT induced the activation of p38 and JNK while diesel oil enhanced activation of both ERK and p38. The activation of MAPKs was observed after 1 h exposure and 6 and 24 h of recovery in seawater. In addition, DNA fragmentation, assessed by two techniques, the Fast micromethod^® and the TUNEL assay, was detected after sponges were treated with both chemicals. Moreover, the study of caspase 3/7 activity showed that apoptosis was induced and triggered with all concentrations of TBT but only at high diesel oil concentrations. After TBT exposure, a correlation was observed between JNK activation, caspase 3 activity and DNA damage while p38 activation followed the two latter parameters at high concentrations of diesel oil, suggesting that sponges enhanced a specific apoptotic pathway depending on the xenobiotic tested. This study demonstrated a high signal response by the sponge Suberites domuncula to the tested chemicals. Cell signaling pathway studies may thus be of use in water quality biomonitoring programs.
-
luciferase a light source for the silica based optical waveguides spicules in the demosponge Suberites domuncula
Cellular and Molecular Life Sciences, 2009Co-Authors: W. E. G. Müller, H. C. Schröder, Xiaohong Wang, Dario Pisignano, M Kasueske, Y Wang, Matthias WiensAbstract:Two classes of sponges (animal phylum Porifera) possess a siliceous skeleton which is composed of spicules. Studying the optical fiber-mechanical properties of large spicules from hexactinellid sponges (> 5 cm) it was demonstrated that they are effective light-collecting optical fibers. Here, we report that the demosponge Suberites domuncula is provided with a biosensor system composed of the (organic) light producing luciferase and the (inorganic) light transducing silica spicules. The light transmission feature of these smaller spicules (200 μm) has been demonstrated and the ability of sponge tissue to generate light has been proven. Screening for a luciferase gene in S. domuncula was successful; the recombinant luciferase was prepared and shown to be bioactive. The luciferase protein is abundantly present in the close neighborhood of the spicules. The expression of the luciferase gene is under the control of light.
-
okadaic acid a potential defense molecule for the sponge Suberites domuncula
Marine Biology, 2003Co-Authors: Matthias Wiens, H. C. Schröder, Renato Batel, Franz Brümmer, Renate Steffen, Barbel Diehlseifert, B Luckas, M Shokry, A Ammar, W. E. G. MüllerAbstract:Sponges are sessile filter feeders that are exposed to toxic compounds/xenobiotics and a huge number of diverse pro- and eukaryotic organisms occurring in the aqueous milieu. To cope with these threats, sponges have developed a variety of chemical and immunological defense systems. Among them are potent secondary metabolites or toxins. The demosponge Suberites domuncula contains the bioactive compound okadaic acid; concentrations of ≈50 ng/g (≈60 nM) of wet tissue have been quantified by LC/MS. In the present study, we sought to determine whether okadaic acid is beneficial for this sponge. Antibodies were raised against okadaic acid and used to localize this compound in situ. It could be demonstrated that the polyclonal antibodies/antiserum stained the sponge cells (endopinacocytes) which form the epithelium of the lacunae and the water channels. They also reacted with bacteria present in sponge tissue. Okadaic acid was found to augment the immune response of S. domuncula against the bacterial endotoxin lipopolysaccharide (LPS). If primmorphs, a special form of 3-D aggregates, are incubated with LPS at a concentration of 3 µg/ml, a reduction in the incorporation rate of [3H] phenylalanine is measured. In the presence of okadaic acid, this effect is measured already at a concentration of 1 µg/ml, suggesting that okadaic acid sensitizes this (immune) response. Okadaic acid is a known inhibitor of protein phosphatases which, as shown here, cause an increased phosphorylation of p38, a central kinase of the MAP kinase pathway; this may explain the sensitive response of the sponge cells to LPS. At higher concentrations, okadaic acid induces apoptosis, as was demonstrated here by a differential expression of the Bcl-2 homolog and the caspase gene. It is concluded that okadaic acid has two functions in the sponge; first, at low concentrations (<100 nM) a stimulation of the defense system against bacteria, and second, at concentrations above 500 nM, a differential effect on the pro-/anti-apoptotic genes.
-
molecular response of the sponge Suberites domuncula to bacterial infection
Marine Biology, 2001Co-Authors: Markus Bohm, Isabel M. Müller, Vera Gamulin, Renate Steffen, Ute Hentschel, Anja B Friedrich, L Fieseler, W. E. G. MüllerAbstract:The aim of this study was the documentation of the molecular immune response of Suberites domuncula upon bacterial infection. Additionally, the bacteria that are naturally present in the sponge after prolonged aquarium maintenance were characterized. After 6 months of maintenance of S. domuncula in seawater aquaria, only one bacterial 16S rDNA sequence could be recovered, which belongs to the genus Pseudomonas. Concomitantly, morphologically uniform bacteria were found encapsulated in bacteriocytes. These findings indicate that certain bacteria, possibly of the genus Pseudomonas, are able to persist for long periods in host bacteriocytes. Subsequent to performing a previously established infection assay with S. domuncula, a potentially pathogenic Vibrio sp. was isolated from the tissues. Furthermore, the host tissue disintegrated and asexual propagation bodies (gemmules) were formed. In order to gain insights into the molecular events occurring after bacterial infection, the stress-response kinases, p38 protein kinase and JNK protein kinase, were analyzed. It is demonstrated that these two kinases are activated (phosphorylated) upon incubation of the tissue with the bacterial endotoxin lipopolysaccharide (LPS). Moreover, LPS strongly inhibits protein synthesis. It is concluded that there are many functionally different interactions between S. domuncula and bacteria and that the animal possesses mechanisms to differentiate between bacteria and to respond accordingly.
