SEARCH · PubMed Health

Results for “Sea Cucumbers”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 19 recordsLinked to original sources

PubMed2006

Concurrence of cat and tet genes in multiple antibiotic-resistant bacteria isolated from a sea cucumber and sea urchin mariculture farm in China.

A basic understanding of abundance and diversity of antibiotic-resistant microbes and their genetic determinants is necessary for finding a way to prevent and control the spread of antibiotic resistance. For this purpose, chloramphenicol and multiple antibiotic-resistant bacteria were screened from a mariculture farm in northern China. Both sea cucumber and sea urchin rearing ponds were populated with abundant antibiotic-resistant bacteria, especially marine vibrios. Sixty-five percent chloramphenicol-resistant isolates from sea cucumber harbored a cat gene, either cat IV or cat II, whereas 35% sea urchin isolates harbored a cat gene, actually cat II. The predominant resistance determinant cat IV gene mainly occurred in isolates related to Vibrio tasmaniensis or Pseudoalteromonas atlantica, and the cat II gene mainly occurred in Vibrio splendidus-like isolates. All the cat-positive isolates also harbored one or two of the tet genes, tet(D), tet(B), or tet(A). As no chloramphenicol-related antibiotic was ever used, coselection of the cat genes by other antibiotics, especially oxytetracycline, might be the cause of the high incidence of cat genes in the mariculture farm studied.

Animals↗

PubMed2002

Enhancement of t-PA-mediated plasminogen activation by partially defucosylated glycosaminoglycans from the sea cucumber Stichopus japonicus.

Sea cucumber glycosaminoglycan (SC-GAG) was isolated from the body wall of the sea cucumber Stichopus japonicus. The SC-GAG consists of a chondroitin sulfate E-type core polymer with sulfated fucose branches attaching glycosidically to almost every disaccharide unit of the core polymer at the C-3 position of the GlcA or at C-4 and/or C-6 position(s) of GalNAc. SC-GAG was subjected to mild acid-hydrolysis, which cleaved selectively the glycosidic linkages between the core polymer and the fucose branches, resulting in two types of partially defucosylated SC-GAG derivatives. One type (type A), obtained by 3 h-hydrolysis, contained 33% of the fucose branches and the other type (type B), obtained by 6-h hydrolysis, contained 10% of the fucose branches. The molecular masses of types A and B were determined to be 8 and 4 kDa, respectively, by gel permeation HPLC. A chondroitinase ABC (Chase ABC)-digestion demonstrated that types A and B contained 46 and 66% of digestable disaccharide units, respectively, and both types contained 29% of E-type unsaturated disaccharide units bearing no fucose branches. Intact SC-GAG and types A and B were compared for t-PA-mediated plasminogen activation by an in vitro assay system. Although intact SC-GAG and type B exhibited rather weak activity at 6.25 microg/ml, type A exhibited 5 to 10-fold higher activity than intact SC-GAG and type B at the same concentration. The activity of type A was almost one-third that of purified chondroitin sulfate E (127 kDa containing 64.5% E-type disaccharide units) from squid cartilage at 6.25 microg/ml concentration. These results suggest that t-PA-mediated plasminogen activation requires the presence of E-type disaccharide units bearing no fucose branches and a molecular mass larger than 7.5 kDa in terms of the chondroitin sulfate E structure with or without fucose branching.

Animals↗

PubMed1983

The nucleotide sequences of 5S rRNAs from a sea-cucumber, a starfish and a sea-urchin.

The nucleotide sequences of 5S rRNA from three echinoderms, a sea-cucumber Stichopus oshimae, a starfish Asterina pectinifera and a sea-urchin Hemicentrotus pulcherrimus have been determined. These 5S rRNAs are all 120 nucleotides long. The echinoderm sequences are more related to the sequences of proterostomes animals such as mollusc, annelids and some others (87% identity on average) than to those of vertebrates (82% identity on average).

Animals↗

PubMed2002

A case study of human migration and the sea cucumber crisis in the Galapagos Islands.

The sea cucumber fishing crisis in Galapagos is an example of the potential consequences of rapid migration, growing economic competition, and weak regulatory mechanisms. In a short period of time sea cucumber fishing has become the most inflammatory issue in the Galapagos. The key factors that allowed for the efficient exploitation of the new resource were not the fishermen themselves but rather the new fishing techniques and access to credit and markets. This suggests that the annual sea cucumber crisis is due to factors more complex than simply more fishermen generating greater sea cucumber catches. This paper examines census data and fisher registries to analyze population growth in the islands. A public opinion survey is used to determine the population's attitudes toward sea cucumber fishing and regulations. Qualitative interviews explore the history of the sea cucumber boom. Information from the sea cucumber monitoring program provides estimates for the annual sea cucumber catches.

Animals↗

PubMed2002

Extracellular matrix remodeling and metalloproteinase involvement during intestine regeneration in the sea cucumber Holothuria glaberrima.

The sea cucumber, Holothuria glaberrima, has the capacity to regenerate its internal organs. Intestinal regeneration is accomplished by the thickening of the mesenteric border and the invasion of this thickening by mucosal epithelium from the esophagus and the cloaca. Extracellular matrix (ECM) remodeling has been associated with morphogenetic events during embryonic development and regeneration. We have used immunohistochemical techniques against ECM components to show that differential changes occur in the ECM during early regeneration. Labeling of fibrous collagenous components and muscle-related laminin disappear from the regenerating intestine and mesentery, while fibronectin labeling and 4G7 (an echinoderm ECM component) are continuously present. Western blots confirm a decrease in fibrous collagen content during the first 2 weeks of regeneration. We have also identified five 1,10-phenanthroline-sensitive bands in collagen gelatin zymographs. The gelatinolytic activities of these bands are enhanced during early stages of regeneration, suggesting that the metalloprotease activity is associated with ECM remodeling. Inhibition of MMPs in vivo with 1,10-phenanthroline, p-aminobenzoyl-Gly-Pro-D-Leu-D-Ala hydroxamate or N-CBZ-Pro-Leu-Gly hydroxamate produces a reversible inhibition of intestinal regeneration and ECM remodeling. Our results show that significant changes in ECM content occur during intestine regeneration in the sea cucumber and that the onset of these changes is correlated to the proteolytic activities of MMPs.

Animals↗

PubMed2003

Dynamic mechanical properties of body-wall dermis in various mechanical states and their implications for the behavior of sea cucumbers.

The dermis of the sea cucumber body wall is a typical catch connective tissue that rapidly changes its mechanical properties in response to various stimuli. Dynamic mechanical properties were measured in stiff, standard, and soft states of the sea cucumber Actinopyga mauritiana. Sinusoidal deformations were applied, either at a constant frequency of 0.1 Hz with varying maximum strain of 2%-20% or at a fixed maximum strain of 1.8% with varying frequency of 0.0005-50 Hz. The dermis showed viscoelasticity with both strain and strain-rate dependence. The dermis in the standard state showed a J-shaped stress-strain curve with a stiffness of 1 MPa and a dissipation ratio of 60%; the curve of the stiff dermis was linear with high stiffness (3 MPa) and a low dissipation ratio (30%). Soft dermis showed a J-shaped curve with low stiffness (0.3 MPa) and a high dissipation ratio (80%). The strain-induced softening was observed in the soft state. Stiff samples had a higher storage modulus and a lower tangent delta than soft ones, implying a larger contribution of the elastic component in the stiff state. A simple molecular model was proposed that accounted for the mechanical behavior of the dermis. The model suggested that stiffening stimulation increased inter-molecular bonds, whereas softening stimulation affected intra-molecular bonds. The adaptive significance of each mechanical state in the behavior of sea cucumbers is discussed.

Adaptation, Biological↗

PubMed1989

Amino acid sequence of a major globin from the sea cucumber Paracaudina chilensis.

The sea cucumber Paracaudina chilensis (Echinodermata) contains three major globins I, II and III in coelomic cells. The complete amino acid sequence of globin I has been determined. It is composed of 157 amino acid residues, is acetylated at the N-terminus, and has a characteristic N-terminal extension of 9-10 residues when compared with vertebrate globins. The sequence of Paracaudina globin I showed slightly higher homology with human alpha globin (25%) rather than with the invertebrate Anadara alpha globin (22%). Paracaudina globin I also showed strong homology (59%) with globin D from another sea cucumber, Molpadia arenicola (Mauri, F.C. (1985) Ph.D. dissertation, University of Texas). The globin sequences from the phylum Echinodermata have an important position in the molecular evolution of the globins, because they are the invertebrate group most closely related to the vertebrates.

Amino Acid Sequence↗

PubMed1984

Interaction of sea cucumber saponins with multilamellar liposomes.

The effect of three sea cucumber saponins, echinoside A, bivittoside D and holothurin A, on multilamellar liposomes was investigated. An ideal osmotic behavior of liposomes was described as a linear relationship between the reciprocal 3/2 s power of absorbance at 450 nm and the osmotic gradient across the membrane. Sea cucumber saponins at concentrations below critical micelle concentration (CMC) disturbed this linear relationship in liposomes composed of egg phosphatidylcholine, phosphatidic acid and cholesterol. Cholesterol-free liposomes were not susceptible to these saponins. Results of optical measurements were consistent with those of transmission electron microscopy, which showed saponin-induced changes in liposomal structure. The lytic activity of sea cucumber saponins on liposomes depended on their chemical structure. These results suggest that sea cucumber saponins as monomers can interact with liposomes and that cholesterol serve as a principal binding site for the sea cucumber saponins.

Animals↗

PubMed2004

RGD-containing peptides inhibit intestinal regeneration in the sea cucumber Holothuria glaberrima.

The sea cucumber Holothuria glaberrima is an echinoderm capable of regenerating its viscera. Previous studies from our group have shown a striking remodeling of the extracellular matrix (ECM) during intestinal regeneration. To study the role of the ECM during regeneration, we have focused on the RGD sequences present in many ECM molecules. Regenerating animals were treated with an RGDS (Arg-Gly-Asp-Ser) peptide that competes with the interaction between RGD sequence and cellular integrins. Saline and RGES (Arg-Gly-Glu-Ser) peptide injections were done as controls. The size of the regenerating intestine was determined, and the regenerating structures were analyzed by immunohistochemistry for the presence of collagen and fibronectin, as well as for muscle and other cells. The results show a delay in intestinal regeneration in animals injected with the RGDS peptide, suggesting that the ECM-integrin interaction plays an important function in the regenerative process.

Animals↗

PubMed2006

Contribution of mesenterial muscle dedifferentiation to intestine regeneration in the sea cucumber Holothuria glaberrima.

Holothurians (sea cucumbers) have been known from ancient times to have the capacity to regenerate their internal organs. In the species Holothuria glaberrima, intestinal regeneration involves the formation of thickenings along the free mesentery edge; these thickenings will later give rise to the regenerated organ. We have previously documented that a remodeling of the extracellular matrix and changes in the muscle layer occur during the formation of the intestinal primordium. In order to analyze these changes in depth, we have now used immunocytochemical techniques and transmission electron microscopy. Our results show a striking disorganization of the muscle layer together with myocyte dedifferentiation. This dedifferentiation involves nucleic activation, disruptions of intercellular junctions, and the disappearance of cell projections, but more prominently, the loss of the contractile apparatus by the formation and elimination of spindle-like structures. Muscle dedifferentiation can be seen as early as 2 days following evisceration and continues during the next 2 weeks of the regeneration process. Dedifferentiation of myocytes might result in cells that proliferate and give rise to new myocytes. Alternatively, dedifferentiating myocytes could give rise to cells with high nuclear-to-cytoplasmic ratios, with some being eliminated by apoptosis. Our results, together with those in other regeneration models, show that myocyte dedifferentiation is a common event in regeneration processes and that the dedifferentiated cells might play an important role in the formation of the new tissues or organs.

Animals↗

PubMed2006

Isolation of sphingoid bases of sea cucumber cerebrosides and their cytotoxicity against human colon cancer cells.

Sea cucumber is a health-beneficial food, and contains a variety of physiologically active substances including glycosphingolipids. We show here the sphingoid base composition of cerebrosides prepared from sea cucumber and the cytotoxicity against human colon cancer cell lines. The composition of sphingoid bases prepared from sea cucumber was different from that of mammals, and the major constituents estimated from mass spectra had a branched C17-19 alkyl chain with 1-3 double bonds. The viability of DLD-1, WiDr and Caco-2 cells treated with sea cucumber sphingoid bases was reduced in a dose-dependent manner and was similar to that of cells treated with sphingosine. The sphingoid bases induced such a morphological change as condensed chromatin fragments and increased the caspase-3 activity, indicating that the sphingoid bases reduced the cell viability by causing apoptosis in these cells. Sphingolipids of sea cucumber might therefore serve as bioactive dietary components to suppress colon cancer.

Animals↗

PubMed1993

Extensive heterogeneity of proteoglycans bearing fucose-branched chondroitin sulfate extracted from the connective tissue of sea cucumber.

The major sulfated polysaccharide in the sea cucumber body wall is a fucose-branched chondroitin sulfate. This glycosaminoglycan has side-chain disaccharide units of sulfated fucopyranosyl or sulfate esters linked to the O-3 position of the beta-D-glucuronic acid residues. These unusual fucose branches and sulfate esters block the access of chondroitinases to the chondroitin sulfate core [Vieira & Mourão (1988) J. Biol. Chem. 263, 18176-18183; Vieira et al. (1991) J. Biol. Chem. 266, 13530-13536]. We now report the isolation and preliminary characterization of the proteoglycans bearing this unique fucose-branched chondroitin sulfate. They were extracted using guanidine hydrochloride solutions containing protease inhibitors and were purified by anion-exchange and gel-filtration columns. Interestingly, the sea cucumber proteoglycans were cleaved by chondroitinase AC or ABC, indicating that the beta-D-glucuronic acid residues close to the reducing end of the polysaccharide chain are neither fucosylated nor sulfated. SDS-polyacrylamide gel electrophoresis revealed several fractions of proteoglycans of different molecular sizes but containing a similar hexuronic acid/protein ratio and a similar type of glycan chain. Possibly, the low-molecular-size fractions arise from a protease cleavage of a larger molecule. In contrast with the results observed for most vertebrate proteoglycans, which contain a single core protein for each type of proteoglycan, chondroitinase AC or ABC releases from the sea cucumber proteoglycans a wide variety of core proteins. These observations are the first detailed study of a proteoglycan from invertebrate tissue and reveal extensive heterogeneity when compared with proteoglycans from vertebrate connective tissue.

Animals↗

PubMed2002

Conserved expression pattern of BMP-2/4 in hemichordate acorn worm and echinoderm sea cucumber embryos.

The auricularia larva of sea cucumbers and tornaria larva of acorn worms share striking developmental and morphological similarities. They are regarded as not only an archetype of the nonchordate deuterostome larva, but also an archetype of the origin of chordates. Here we report the characterization and spatial expression patterns of the BMP-2/4 genes of a hemichordate acorn worm (Pf-bmp2/4) and an echinoderm sea cucumber (Sj-bmp2/4). Both the Pf-bmp2/4 and Sj-bmp2/4 genes exhibited apparently conserved expression in the region of the coelomopore complex. This is in agreement with the homology between their basic larval body plans with respect to coelomogenesis and allows us to discuss the evolutionary counterparts of the coelomopore complex in chordates.

Amino Acid Sequence↗

PubMed1999

Fatty acid compositions in local sea cucumber, Stichopus chloronotus, for wound healing.

Fatty acid profile from crude extracts of local sea cucumber Stichopus chloronotus was determined using gas chromatography (GC) technique. The extracts were prepared separately in methanol, ethanol, phosphate buffer saline (PBS), and distilled water as part of our study to look at the affinity of these solvents in extracting the lipid from sea cucumber. The PBS and distilled water extractions indicate water-soluble components, while the organic fractions are extracted in methanol and ethanol as organic solvents. Furthermore, water extraction is the conventional method practiced in Malaysia. In our analysis the C14:0 (myristic), C16:0 (palmitic), C18:0 (stearic), C18:2 (linoleic), C20:0 (arachidic), and C20:5 (eicosapentaenoic, EPA) were significantly different (p < 0.01) in the four solvent extractions. However, the PBS extraction contained a much higher percentage of EPA (25.69%) compared to 18.89% in ethanol, 7.84% in distilled water, and only 5.83% in methanol, and variances were significantly different (p < 0.01 ). On the other hand, C22:6 (docosahexaenoic acid or DHA) is much higher in water extraction (57.55%), in comparison to the others where only 3.63% in PBS and 1.20% in methanol, and this difference is significant at p < 0.01. No DHA was detected in ethanol extractions. Subsequently, C18:1 (oleic acid) was only detected in PBS (21.98%) and water extraction (7.50%). It is interesting that palmitic acid, C16:() was higher in methanol (20.82%) and ethanol (2.18%), while 12.55% was detected in PBS and only 2.20% in water extraction: and again this was significantly different at p < 0.01. Although our results have shown that all four solvents were different in terms of their ability to extract fatty acids, the major component for tissue repair was well preserved. Probably this is one of the important precocious steps when working with a delicate sea cucumber, in both experimental and/or at the preparative stages. Freshness of the sea cucumber samples is important when undertaking this type of experiment. Finally, we believe that the local sea cucumber S. chloronotus contains all the fatty acids required to play a potential active role in tissue repair.

Animals↗

PubMed1995

In vivo and in vitro biosynthesis of saponins in sea cucumbers.

The triterpene precursor of saponins in sea cucumbers has been identified as parkeol [lanost-9(11)-en-3 beta-ol] [1]. Dissection of the sea cucumbers Holothuria floridea and Actinopyga agassize after incubations with radiolabeled parkeol demonstrated that saponin biosynthesis occurs exclusively in the Cuvier gland. This result was corroborated by incubating a cell-free extract of the Cuvier gland with labeled parkeol and observing transformation of the precursor to saponins.

Animals↗

PubMed2000

A sulfated polysaccharide from the sarcoplasmic reticulum of sea cucumber smooth muscle is an endogenous inhibitor of the Ca(2+)-ATPase.

Vesicles derived from the endoplasmic reticulum of sea cucumber smooth muscle retain a membrane bound Ca(2+)-ATPase that is able to transport Ca(2+) into the vesicles at the expense of ATP hydrolysis. In contrast with vesicles obtained from rabbit muscles, the activity of the Ca(2+)-dependent ATPase from sea cucumber is dependent on monovalent cations (K(+)>Na(+)>Li(+)). With the addition of highly sulfated polysaccharide to vesicle preparations from rabbit muscle, Ca(2+) uptake decreases sharply and becomes highly sensitive to monovalent cations, as observed with vesicles from sea cucumber muscle. These results led us to investigate the possible occurrence of a highly sulfated polysaccharide on vesicles from the endoplasmic reticulum of sea cucumber smooth muscle, acting as an "endogenous" Ca(2+)-ATPase inhibitor. In fact, vesicles derived from the invertebrate, but not from rabbit muscle, contain a highly sulfated polysaccharide. This compound inhibits Ca(2+) uptake in vesicles obtained from rabbit muscle and the inhibition is antagonized by monovalent cation. In addition, sea cucumber muscles contain high concentrations of another polysaccharide, which surrounds the muscle fibers, and was characterized as a fucosylated chondroitin sulfate. Possibly the occurrence of sulfated polysaccharides in the sea cucumber muscles is related with unique properties of the invertebrate body wall, which can rapidly and reversibly alter its mechanical properties, with change in length by more than 200%.

Animals↗

PubMed1990

Glycosaminoglycan involved in the cation-induced change of body wall structure of sea cucumber Stichopus japonicus.

The body wall of sea cucumber Stichopus japonicus was treated with various concentrations of several cations, and examined for changes in toughness, taking punch force as parameter. Toughness of the body wall tended to decrease with increasing concentration of each cation, but in different modes depending mainly upon the valency of cation: e.g., the body wall completely lost toughness in 0.3 M Na+ or 0.4 M K+, whereas it retained more than half the initial toughness even in 0.4 M Ca2+ or Mg2+. Glycosaminoglycan (GAG) from the body wall was dissolved in water, and examined for viscosity changes as caused by those cations. Specific viscosity (eta sp) decreased from 0.71 (without cation) to 0.47-0.57 in the presence of 0.1 M monovalent and divalent cations. At 0.4 M, monovalent cations reduced eta sp to 0.38-0.46, but divalent cations increased eta sp to 0.56-0.63. Electron microscopy demonstrated that GAG matrix was clearly observed in the absence of cation, but disappeared in 0.4 M NaCl, forming wide free spaces in the body wall. These results all suggested that GAG is closely involved in the change of toughness of sea cucumber body wall.

Animals↗

PubMed1998

Peptides controlling stifness of connective tissue in sea cucumbers.

We present the first evidence of a system of four bioactive peptides that affect the stiffness of sea cucumber dermis. The body wall dermis of sea cucumbers consists of catch connective tissue that is characterized by quick and drastic stiffness changes under nervous control. The peptides were isolated from the body wall, their amino acid sequences determined, and identical peptides synthesized. Two peptides, which we named holokinins, are homologous with bradykinin. We tested the effect of the peptides on the mechanical properties of sea cucumber dermis. Both of the holokinins softened the dermis, and a pentapeptide that we designated as NGIWYamide stiffened it. Both effects were reversibly suppressed by anesthesia with menthol. We called the fourth peptide stichopin; it had no direct effect on the stiffness of the dermis but suppressed action of the neurotransmitter acetylcholine reversibly. The results suggest that the peptides are neuropeptides and are part of a sophisticated system of neurotransmitters and neuromodulators that controls the connective tissue stiffness of sea cucumber dermis.

Amino Acid Sequence↗