Asterias Amurensis Research Articles

Structural determination of cerebrosides isolated from Asterias amurensis starfish eggs using high‐energy collision‐induced dissociation of sodium‐adducted molecules

Six cerebrosides were isolated from the eggs of the starfish Asterias amurensis using solvent extraction, silica gel column chromatography, and reversed-phase high-performance liquid chromatography. This study demonstrated that the structures of cerebrosides could be completely characterized, based on their sodium-adducted molecules, using fast atom bombardment (FAB) tandem mass spectrometry. The high-energy collision-induced dissociation of the sodium-adducted molecule, [M + Na](+), of each cerebroside molecular species generated abundant ions, providing information on the compositions of the 2-hydroxy fatty acids and long-chain sphingoid bases, as well as the sugar moiety polar head group. Each homologous ion series along the fatty acid and aliphatic chain of the sphingoid base was useful for locating the double-bond positions of both chains and the methyl branching position of the long-chain base. The N-fatty acyl portions were primarily long-chain saturated or monoenoic acids (C16 to C24) with an α-hydroxy group. The sphingoid long-chain base portions were aliphatic chains (C18 or C22) with two or three degrees of unsaturation and with or without methyl branching.

Ethylacetate fraction from Korean seaside starfish, Asterias amurensis, has an inhibitory effect on MMP-9 activity and expression and on migration behavior of TNF-α induced human aortic smooth muscle cells

Atherosclerosis is accompanied by the proliferation of human aortic smooth muscle cells (HASMC) and their movement into the intima. Many reports have indicated the involvement of gelatinases (MMP-9 and MMP-2) in this pathogenesis. The ethylacetate fraction from starfish, Asterias amurensis (EFA), harvested from the Korean seaside has an inhibitory effect on MMP-9 and MMP-2 activities, as well as on the expression of MMP-9 in TNF-α induced HASMC in a dose-dependent manner. Also, EFA inhibits the migration of TNF-α induced HASMC in transwells containing gelatin coated plugs. EFA was not cytotoxic to HASMC over the range 0–1 mg/ml. By Western-blot analysis, it was revealed that the phosphorylation of extracellular signal regulated kinase (ERK) in TNF-α induced cells was inhibited and nuclear factor kappa B (NF-κB) p65 levels in nuclear extracts were decreased by EFA treatment. In addition, ERK inhibitor (U0126) treated cells exhibited decreased MMP-9 activity in the zymographic assay. From these results, it was found that the gelatinolytic activity was regulated (1) by enzymatic inhibition of both MMP-9 and MMP-2, as well as (2) by the decreased production of MMP-9 via ERK pathways in EFA treated HASMCs. Taken together, it has been shown that EFA has a putative anti-atherosclerotic effect.

Starfish, Asterias amurensis and Asterina pectinifera, as Potential Sources of Th1 Immunity-Stimulating Adjuvants

Saponin is the generic name of steroid or triterpene glycosides, and the capacities of some saponins to stimulate both Th1 immune response and production of cytotoxic T cells are useful as vaccine components against intracellular pathogens. Because saponins have been found commonly in starfish, we assessed the potential of starfish, Asterias amurensis and Asterina pectinifera, as adjuvant sources. Crude starfish saponins had hemolytic activities (EC(50)=10 to 100 µg/ml) and thin layer chromatography indicated heterogeneity of their constituents. When starfish saponis were subcutaneously injected into mice with ovalbumin (OVA), OVA-specific IgG, especially IgG2a instead of IgG1 was produced in mouse blood, suggesting starfish saponins stimulated Th1 type immunity and they were potential sources of new adjuvants.

Asterosaponins Isolated from the Starfish Asterias amurensis

Three new asterosaponins 1-3 and four known saponins 4-7 have been isolated from the starfish Asterias amurensis LÜTKEN. By means of high magnetic field 1D- and 2D-NMR ((1)H-(1)H correlation spectroscopy (COSY), total correlation spectroscopy (TOCSY), heteronuclear multiple quantum coherence (HMQC), heteronuclear single quantum coherence (HSQC), heteronuclear multiple bond correlation (HMBC), and nuclear Overhauser effect spectroscopy (NOESY)) and MS analyses, the chemical structures of new compounds were determined to be 6α-O-[β-D-fucopyranosyl-(1→2)-β-D-galactopyranosyl-(1→4)-[β-D-quinovopyranosyl-(1→2)]-β-D-quinovopyranosyl-(1→3)-β-D-galactopyranosyl]-5α-chol-9(11)-en-23-one-3β-yl sodium sulfate (1), 6α-O-[β-D-fucopyranosyl-(1→2)-β-D-galactopyranosyl-(1→4)-[β-D-quinovopyranosyl-(1→2)]-β-D-quinovopyranosyl-(1→3)-β-D-galactopyranosyl]-5α-cholesta-9(11),24-dien-23-one-3β-yl sodium sulfate (2), and 6α-O-[β-D-fucopyranosyl-(1→2)-β-D-galactopyranosyl-(1→4)-[β-D-quinovopyranosyl-(1→2)]-β-D-quinovopyranosyl-(1→3)-β-D-galactopyranosyl]-5α-cholest-9(11)-en-23-one-3β-yl sodium sulfate (3). In addition, the NMR data for known saponins 4-7 were completely assigned by extensive 2D-NMR analysis without chemical degradation.

Novel conserved structural domains of acrosome reaction‐inducing substance are widespread in invertebrates

In the starfish Asterias amurensis, acrosome reaction inducing substance (ARIS) is the main factor responsible for allowing sperm to recognize the egg jelly and begin the acrosome reaction (AR). ARIS is a large proteoglycan-like molecule, and its pentasaccharide repeat, Fragment 1 (Fr. 1), is responsible for inducing AR. Here, we investigated the primary structure of ARIS for the first time in order to improve our understanding of its functionality. Electrophoretic analysis revealed that ARIS is a complex of three proteins, all of which are modified by the Fr. 1 sugar chain. Sequencing indicated that there are two novel, conserved domains in all three ARIS proteins: ARIS N-terminus (AR-N) and ARIS C-terminus (AR-C) domains. We also found that other echinoderms possess ARIS proteins that are capable of inducing the AR for homologous sperm, indicating that ARIS proteins may be a ubiquitous component for echinoderm fertilization. Moreover, we identified ARIS-like genes from Ctenophora to Protochordata.

Perceptions of environmental change over more than six decades in two groups of people interacting with the environment of Port Phillip Bay, Australia

Assessment of environmental change over long periods of time is often impossible due to the absence of long-term quantitative data. Because it is not possible to collect such data retrospectively, qualitative data may provide some understanding of variation in environmental parameters over large temporal scales. The potential of qualitative data to yield valid and informative conclusions hinges on the extent of consistency in those data. The present study explored the potential for semi-structured interviews to serve as a data source for the retrospective assessment of environmental change. Two groups of people (anglers and divers) interacting with the environment of Port Phillip Bay, Australia, were questioned about their perceptions of change in that environment. Accounts covered more than six decades and several patterns emerged. Commercial dredging for scallop ( Pecten fumatus) was assumed to have had a major negative impact on many taxa. Abundance of Snapper ( Pagrus auratus) increased after dredging ceased in the mid-1990s though size and abundance were reduced relative to the early 1960s. The abundance of Flathead spp. ( Neoplathycephalus richardsoni, Plathycephalus laevigatus & Plathycephalus arenarius) declined, and the spread of an introduced seastar ( Asterias amurensis) was implicated in this decline. Importantly, the overall condition of Port Phillip Bay appears to have deteriorated on a large scale. Many species of fish and invertebrates purportedly disappeared or declined over the course of six decades. Similarly, a substantial reduction of macroalgae was noted. This preliminary study underscores the potential of qualitative data to assess environmental conditions in the past and illustrates the capacity for interdisciplinary research to aid in management and conservation.

Acrosome reaction-related steroidal saponin, Co-ARIS, from the starfish induces structural changes in microdomains

Cofactor for acrosome reaction-inducing substance (Co-ARIS) is a steroidal saponin from the starfish Asterias amurensis. Saponins exist in many plants and few animals as self-defensive chemicals, but Co-ARIS has been identified as a cofactor for inducing the acrosome reaction (AR). In A. amurensis, the AR is induced by the cooperative action of egg coat components (ARIS, Co-ARIS, and asterosap); however, the mechanism of action of Co-ARIS is obscure. In this study we elucidated the membrane dynamics involved in the action of Co-ARIS. We found that cholesterol specifically inhibited the Co-ARIS activity for AR induction and detected the binding of labeled compounds with sperm using radioisotope-labeled Co-ARIS. Co-ARIS treatment did not reduce the content of sperm sterols, however, the condition was changed and localization of GM1 ganglioside on the periacrosomal region disappeared. We then developed a caveola-breaking assay, a novel method to detect the effect of chemicals on microdomains of culture cell, and confirmed the disturbance of somatic cell caveolae in the presence of Co-ARIS. Finally, by atomic force microscopy observations and surface plasmon resonance measurements using an artificial membrane, we revealed that Co-ARIS colocalized with GM1 clusters on the microdomains. Through this study, we revealed a capacitation-like event for AR in starfish sperm.

The Effect of Low Salinity on the Eertilization and Development in the Starfish, Asterias amurensis

The Effect of Low Salinity on the Eertilization and Development in the Starfish, Asterias amurensis

ChemInform Abstract: In situ Activating Glycosylation of 6-Deoxysugars: Synthesis of O-α-D-Fucosyl-(1→4)-O-α-D-fucosyl- (1→4)-O-α-D-quinovosyl-(1→4)-D-quinovose.

The linear tetrasaccharide, α-D-fucopyranosyl-(1→4)-α-D-fucopyranosyl-(1→4)-α-D-quinovopyranosyl-(1→4)-D-quinovopyranose, the sugar cluster of asterosaponin A from the starfish, Asterias amurensis, was synthesized in a convergent manner. We employed an in situ activating glycosylation using 1-OH sugar derivatives and a system of p-nitrobenzenesulfonyl chloride, silver trifluoromethanesulfonate, and triethylamine as well as a related system.

Isolation of a new glycoside from starfish, Asterias amurensis Lutken, and its stimulation activity on the proliferation of the UMR106 cell

A new glycoside compound (1) was isolated from the starfish Asteria amurensis Lutken. The structure for compound 1 was identified as 1-O-{β-D-quinovopyranosyl–(1-2)-β-D-fucopyranosyl-(1-4)-[β-D-fucopyranosyl(1-2)] β-D-quinovopyranosyl}-butanol by extensive NMR experiments as well as chemical evidence. The effects of compound 1 on UMR106 cell proliferation were screened by MTT assay. The results indicate that compound 1 (0.01–100 µM) significantly promotes osteoblastic proliferation.

Quantitative distribution of the starfish in some bays of the far east

The quantitative distribution of the starfish was analyzed in Vostok Bay, Nakhodka Bay, and Kievka Bay (the Sea of Japan). Nine species were found. Three species of Asteroidea dominated (Asterina pectinifera, Asterias amurensis, and Leptasterias sp.). The population density of A. pectinifera and A. amurensis was higher in the shallow waters compared to the sublittoral zone. The frequency of the occurrence, the biomass, and the population density of Leptasterias sp. were the highest for the shallow waters and decreased accordingly when the water temperature decline on the transect from Vostok Bay to Kievka Bay. In Kievka Bay, which was characterized by the lowest water temperatures, Leptasterias sp. dominated in the littoral and sublittoral zones followed by A. pectinifera and A. amurensis.

Colwellia asteriadis sp. nov., a marine bacterium isolated from the starfish Asterias amurensis

A marine bacterial strain, KMD 002T, was isolated from an Amur starfish, Asterias amurensis, collected in the East Sea of Korea. Strain KMD 002T was a Gram-negative, beige-pigmented, rod-shaped bacterium. The strain was capable of growth at relatively low temperatures (4-25 degrees C) and over a broad pH range (pH 4.0-10.0). The major fatty acids were C16:1omega7c and/or iso-C15:0 2-OH and C16:0 and the predominant isoprenoid quinone was Q-8. The DNA G+C content of strain KMD 002T was 40.3 mol%. Phylogenetic analysis using 16S rRNA gene sequences revealed that strain KMD 002T belonged to the genus Colwellia. However, various phenotypic properties as well as low 16S rRNA gene sequence similarities to members of the genus Colwellia (94.1-96.7%) suggested that strain KMD 002T is a representative of a novel species, for which the name Colwellia asteriadis sp. nov. is proposed. The type strain is KMD 002T (=KCCM 90077T =JCM 15608T).

Kistimonas asteriae gen. nov., sp. nov., a gammaproteobacterium isolated from Asterias amurensis

A novel marine bacterium, strain KMD 001(T), was isolated from the starfish Asterias amurensis, which inhabits the East Sea of Korea. Strain KMD 001(T) was aerobic, light-yellow pigmented and Gram-stain-negative. Analyses of the 16S rRNA gene sequence revealed that strain KMD 001(T) represents a novel lineage within the class Gammaproteobacteria. Strain KMD 001(T) is closely related to the genera Endozoicomonas and Zooshikella, which belong to the family Hahellaceae and to the order Oceanospirillales. The 16S rRNA gene sequence of strain KMD 001(T) shows similarities of approximately 91.8-94.6 % with the above-mentioned genera. The DNA G+C content of KMD 001(T) is 47.6 mol%. It contains Q-9 as the major isoprenoid quinone. The predominant fatty acids were determined to be anteiso-C(15 : 0), iso-C(15 : 0), iso-C(14 : 0) and iso-C(16 : 0). Strain KMD 001(T) should be assigned to a novel bacterial genus within the class Gammaproteobacteria based on its phylogenetic, chemotaxonomic and phenotypic characteristics. The name Kistimonas asteriae gen. nov., sp. nov. is proposed. The type strain is KMD 001(T) (=KCCM 90076(T) =JCM 15607(T)).

Biochemical Characterization of Collagen from the Starfish Asterias amurensis

The industrial use of bovine and porcine collagen has been expanded to include foods, cosmetics, and biomaterials. However, due to outbreaks of bovine spongiform encephalopathy and foot and mouth disease, new, alternative, safe sources of collagen are being sought. In this study, pepsinsolubilized collagen (PSC) was isolated from the tissue of a starfish (Asterias amurensis) and shown to consist of (α1)2α2 heterotrimer, which is similar to calf skin type I collagen. However, the PSC was denaturated at 24.7oC, which is about 12oC lower than mammalian collagen. Immunoblotting assay using polyclonal anti-type I collagen antibody revealed that the starfish collagen contained similar affinity motifs. In XTT assay, PSC suspension had cell growth activity and no showed no cytotoxicity.

Dynamics of the abundance of some bivalve species in Russian waters of the Sea of Japan and its prognosis

The abundance dynamics of several species of bivalve mollusks spats were studied on scallop collectors situated in Minonosok bay of Pos’eta Gulf for 27 years and for 4 years in Kit bay of the Sea of Japan (Russia). A significant positive relation was found between the species having similar thermopathy: the Japanese scallop Mizuhopecten yessoensis and Swift’s scallop Swiftopecten swifti, as well as between the wrinkled rock borer Hiatella arctica and Swift’s scallop Swiftopecten swifti. A significant reverse relation was found between the bay mussel Mytilus trossulus and the Northern Pacific seastar Asterias amurensis. Some of the studied mollusks of Minonosok bay and the remote Kit bay display a significant reversed interrelation in their abundance dynamics caused by the precipitation regime. The one-way dispersion analysis a revealed significant influence of the water temperature in June and the precipitation abundance in the summer on Swift’s scallop’s dynamic abundance. The two-way dispersion analysis showed a significant influence of the ice period duration and the solar activity expressed in Wolf’s numbers on the Japanese scallop abundance dynamics. The uneven years in the period from 1977 to 1984 were usually productive for M. yessoensis and S. swifti spat. After 1985, the even years became more productive (there was asynchronicity in the abundance dynamics compared with 1977–1984). Such asynchronicity appeared with the advent of the new 22-year solar cycle, which caused a change in the magnet polarity in 1986.

Insecticidal and Repellent Activities of Crude Saponin from the Starfish Asterias Amurensis

Crude saponin, extracted from the starfish Asterias amurensis, was assessed for its capacity as a biological pesticide. As part of this analysis, its insecticidal and repellent activities, in addition to its acute and chronic toxicities were tested. In comparison with the control group, insecticidal activity of saponin against tobacco cutworm, Spodoptera litura, in kale, Brassica loeracea was low at 36.4%. Repellent activities of the extracted saponin against green peach aphid, Myzus persicae, and S. litura, on soybean leaf, Glycine max and kale were 65.6% and 35.0% at day, and 54.5% and 30.0% at day, respectively. Acute and chronic toxicity analysis was carried out using acute immobilizatioin test and reproduction impairment test, respectively. The saponin had 48 h- of . Twenty-one day accumulative reproduction after treatment was lower in Daphnia magna at $7{\mu}g/mL$ saponin (78 youngs), compared with the control group (129 youngs). These results indicate that the extracted saponin exhibited some toxicity and has potential as a repellent against insects.

Long-term Changes in Intra- and Inter-specific Relationships in a Community of Scallops and Sea Stars under Bottom Scallop Mariculture

Changes in a common benthic community of mobile Japanese scallops Patinopecten (=Mizuhopecten) yessoensis and predatory sea stars under introduction of mariculture were assessed by comparing the distribution and abundance of each species, and the relationships between densities of these community elements in natural biotope and after twice-repeated seeding of young scallops on the bottom. Under mariculture, at high scallop density (up to 6 ind./m2), the scallop growth rates noticeably decreased. The density of the sea star Asterina (=Patiria) pectinifera markedly decreased, and its distribution was not dependent on scallop density both before and during mariculture. Mean sea star Distolasterias nipon density was also diminished, but aggregate response to high prey density increased. In contrast, the sea star Asterias amurensis density noticeably increased, and it positively correlated with scallop density before and during mariculture. The reduction of densities of sea stars A. pectinifera and D. nipon in mariculture conditions is likely to be explained by the increase in abundance of the large and mobile sea star A. amurensis as the competition for food resources seems to occur. Even big 2-y-old scallops (85.4 ± 1.5 mm shell height) at high density (>2 or 4 scallops per m2, for different sea stars) attract such predatory sea stars as A. amurensis and D. nipon. The results indicate that seeding of young scallops on the bottom and especially reseeding markedly increase the attraction of the biotope to predatory sea stars for a long time.

Conserved sequences of sperm-activating peptide and its receptor throughout evolution, despite speciation in the sea star Asterias amurensis and closely related species

The asteroidal sperm-activating peptides (asterosaps) from the egg jelly bind to their sperm receptor, a membrane-bound guanylate cyclase, on the tail to activate sperm in sea stars. Asterosaps are produced as single peptides and then cleaved into shorter peptides. Sperm activation is followed by the acrosome reaction, which is subfamily specific. In order to investigate the molecular details of the asterosap-receptor interaction, corresponding cDNAs have been cloned, sequenced and analysed from the Asteriinae subfamily including Asterias amurensis, A. rubens, A. forbesi and Aphelasterias japonica, as well as Distolasterias nipon from the Coscinasteriinae subfamily. Averages of 29% and 86% identity were found from the deduced amino acid sequences in asterosap and its receptor extracellular domains, respectively, across all species examined. The phylogenic tree topology for asterosap and its receptor was similar to that of the mitochondrial cytochrome c oxidase subunit I. In spite of a certain homology, the amino acid sequences exhibited speciation. Conservation was found in the asterosap residues involved in disulphide bonding and proteinase-cleaving sites. Conversely, similarities were detected between potential asterosap-binding sites and the structure of the atrial natriuretic peptide receptor. Although the sperm-activating peptide and its receptor share certain common sequences, they may serve as barriers that ensure speciation in the sea star A. amurensis and closely related species.

Two new steroidal compounds from starfish Asterias amurensis Lutken

Two new sulfated steroidal compounds (1 and 2), along with three known steroidal saponins (3, 4, and 5) were isolated from the starfish Asterias amurensis Lutken. The structures of new compounds were elucidated as 3β-O-sulfated-cholest-5-ene-7α-ol (1) and (E) 25-O-β-d-xylopyranosyl-26, 27-dinor-24(S)-methyl-22-ene-15α-O-sulfated-5α-cholest-3β,6α-ol (2) by extensive NMR experiments and chemical evidence. Their effects on UMR106 cell proliferation were screened by MTT method. The results indicated that compounds 2 and 2a (0.01–100 μM) significantly promoted the osteoblastic proliferation. The initial structure–activity relationship analysis suggests that the sugar moiety is the necessary group for the activity.

Management of an invasive marine species: defining and testing the effectiveness of ballast-water management options using management strategy evaluation

Abstract Dunstan, P. K., and Bax, N. J. 2008. Management of an invasive marine species: defining and testing the effectiveness of ballast-water management options using management strategy evaluation. – ICES Journal of Marine Science, 65: 841–850. Invasive marine and fresh-water species are being spread around the world in ships' ballast water, damaging industries and natural resources. Management policies are being developed nationally and internationally in response to the threat, but these options are not being rigorously evaluated for their potential to meet management objectives. We used management strategy evaluation (MSE) simulation to compare the performance of different management rules for controlling the spread of an invasive sea star, Asterias amurensis, around the southern coast of Australia. A model incorporating population dynamics, oceanographic patterns, and vessel movement was developed to compare the performance of different ballast-water exchange rules at reducing the likelihood of new populations establishing at locations along the coast over time. Static management rules, where ballast exchange was mandated on all voyages, reduced the median likelihood of new invasions from 0.67 with no ballast control to between 0.36 and 0.42 as distance from the coast was varied. Reducing the volume of high-risk ballast water by 95% did not reduce the likelihood of invasion by 95%, but by an average of 21%. Exchanging ballast farther from the coast did not reduce the likelihood of invasion for any of the static management rules. Feedback management rules using a port monitoring programme to assess the risk of transporting larvae between ports were at least as effective as the static rules, but at a significantly reduced cost for this single-species example. MSE provides a method to compare management options against objectives in this uncertain environment, and can be used to evaluate new and expensive treatment options for their effectiveness and value.