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PubMed1990

[Preliminary observations on the effect of sjamp on the fibrinolytic system].

The effects of Sjamp, an acidic mucopolysaccharide extracted from Stichopus japonicus Selenka, on fibrinolytic activities were studied. The results showed that Sjamp could induce fibrinolysis in vitro, and the effects were stronger than those of heparin. The fibrinolytic activity of Sjamp disappeared when plasminogen was removed from the fibrin clot. This suggested that the fibrinolytic activity of Sjamp might depend upon plasminogen activation. The fibrinolytic activity and FDP concentration of rabbit plasma increased after intravenous injection of Sjamp. Fibrin monomer polymerization (FMP) was also inhibited by Sjamp, so the structure of fibrin clots might be altered, facilitating lysis. The mechanism of fibrinolytic effect of Sjamp and the significance of this effect in biomedicine are discussed.

Animals↗

PubMed1990

[The effect of holotoxin A1 on transport of calcium ions across the lipid models of biological membranes].

Planar bilayer lipid membranes formed from trepang phospholipids possess an intrinsic Ca2(+)-permeability. These phospholipids dissolved in a non-polar solvent can extract 45Ca2+ from the aqueous to the organic phase. The triterpenic glycoside holotoxin A isolated from the trepang Stichopus japonicus inhibits the Ca2+ flux of lipid bilayers from trepang phospholipids as well as the Ca2+ flux induced in phosphatidylcholine bilayers by the calcium ionophore X-537A. Toxin inhibits the Ca2+ ionophore A23187 induced Ca2+ efflux from phosphatidylcholine liposomes and 45Ca2+ transition from the aqueous to the organic phase. Holotoxin A does not inhibit the 45Ca2+ transfer to the non-polar phase induced by holoturia phospholipids and does not affect the phosphatidylcholine hydroperoxide-induced Ca2+ flux of lipid bilayers. Using the fluorescent probe pyrene, it was demonstrated that toxin increases the microviscosity of liposomal membranes and trepang oocyte "ghosts".

Animals↗

PubMedDate not supplied

[The contraceptive activity of triterpene glycosides--the total sum of holotoxins A1 and B1 and holothurin A in an experiment].

The sum of triterpene glycosides of the Far Eastern holothurian Stichopus japonicus Selenka (holotoxins A1 and B1) possesses the contraceptive activity. Glycoside holoturin A of the tropical holothurian Holoturia atra lacks these properties. The action of the sum of holotoxins is based on the estrogenic activity which was demonstrated both in the uterotropic and vaginotropic tests. The drug under study suppresses ovulation and stimulates the contractile activity of the uterus.

Animals↗

PubMed1979

[Effect of triterpene glycosides on plasma membrane permeability for UV-absorbing substances in Saccharomyces carlsbergensis yeast cells].

The effect of triterpene glycosides of cauloside C from Caulophyllum robustum M, stichoposide A from Stichopus japonicus S. and theasaponine from Thea sinensis Z. on permeability of plasmic membranes of Saccharomyces carlsbergensis for UV-absorbing substances was studied. It was found that incorporation of 14C-uridine from the endocellular pool into the yeast acid-insoluble fraction decreased under the effect of the triterpene glycosides as a result of the precursor leakage from the cell into the medium. It was found that the triterpene glycosides stimulated the leakage of the UV-absorbing substances with an absorption maximum at 260 nm from the cells. The maximum membranotropic effect was observed at 30--40 degrees C and in the presence of monovalent potassium, sodium, ammonium and lithium ions in the medium. Cauloside C and theasaponine, pentacyclic glycosides had the highest effect on the permeability at pH 4.8--5.6, while stichoposide A, a tetracyclic glycoside, had the highest effect at pH 7.0.

Cell Membrane Permeability↗

PubMedDate not supplied

[Analysis of free cholesterol levels in human serum using holotoxin A1].

Triterpene glycosides from holothurians holotoxin A1, stichoposides C and D were used for assay of blood serum free cholesterol instead of digitonin. Blood serum lipids were extracted by a mixture of acetone-ethanol (1:1). Free cholesterol was precipitated from the extract after addition of the glycosides and analyzed in reactions with acetic anhydride, acetic and sulfuric acids. These results were compared with the data of an enzymatic test for estimation of free cholesterol. Holotoxin A1 from Stichopus japonicus enabled to obtain results similar to those demonstrated with digitonin (r = 0.98). Holotoxin A1 may be used instead of digitonin in clinical practice for assay of free cholesterol content in blood serum.

Cholesterol↗

PubMed1978

[Effect of triterpene glycosides on the plasma membrane permeability for amino acids in Saccharomyces carlsbergensis yeast cells].

The effect of triterpen glycosides, such as cauloside C from Caulophyllum robustum, stichoposide A from Stichopus japonicus S and the asaponine from Thea sinensis L on permeability of the plasmic membranes for amino acids was studied. It was shown that the glycosides induced higher levels of liberation of the amino acids with positively or negatively charged molecules from the cells of Saccharomyces carlsbergensis as compared to the control. The transport of the non-polar amino acids was least affected by addition of the saponines to the incubation medium.

Amino Acids↗

PubMedDate not supplied

[Effect of triterpene glycosides and polyene antibiotics on cell membrane permeability for K+ ions and UV-absorbing substances].

The effect of triterpene glycosides (cauloside C from Caulophyllum robustum, theasaponine from Thea sinensis, cucumarioside G from Cucumaria fraudatrix stichoposide A from Stichopus japonicus S., holothurines A and B from Holothuria mexicana, holothurine C from Bohadschia sp.) on the membrane permeability for K+ ions and UV-absorbing substances was compared with that of polyene antibiotics, viz., amphotericine B and nystatine. As a biological model fertilized eggs of sea urchin Strongylocentrotus nudus and yeast Saccharomyces carlsbergensis were used. In the sea urchin study most triterpene glycosides in low concentrations induced the outflux of K+ and in hgih concentrations that of both K+ and UV-absorbing agents. In the yeast study triterpene glycosides at identical doses induced the outflux of both K+ and UV-absorbing agents. The membranotropic effect of triterpene glycosides depended on the medium temperature and the biological system used.

Anti-Bacterial Agents↗

PubMedDate not supplied

[Effect of triterpene glycosides on the biosynthesis of sterols and fatty acids by the yeast Saccharomyces carlsbergensis].

The effect of cauloside C from Caulophyllum robustum M., theasaponine from Thea sinensis L. and stichoposide A from Stichopus japonicus S. on the biosynthesis of sterols and fatty acids by the yeast Saccharomyces carlsbergensis was studied. In in vivo and in vitro experiments cauloside C and theasaponine inhibited ergosterol biosynthesis at the stage of squalene-to-lanosterol transformation. In in vivo experiments stichoposide A inhibited squalene biosynthesis. The triterpene glycosides tested showed a typical feature: in in vivo and in vitro experiments they blocked the biosynthesis of fatty acids.

Ergosterol↗

PubMed1977

[Effect of triterpene glycosides on RNA biosynthesis in a yeast cell culture of Saccharomyces carlsbergensis].

The effect of triterpen glycosides of cauloside C from Caulophyllum robustum, theasaponine from Thea sinensis ahd stichoposide A from Stichopus japonicus on multiplication and biosynthesis of RNA in the cells of a 7-hour culture of Saccharomyces carlsbergensis was studied. It was shown that cauloside C, theasaponine and stichoposide A in concentrations of 7.5 gamma/ml inhibited multiplication of the yeast cells by 65, 10 and 90 per cent respectively. The summation RNA of the yeast cells is divided into 3 zones on Sephadex G-100. The glycosides induced no pronounced changes in the chromotographic profile of RNA. Biosynthesis of the transport and ribosomal RNA were inhibited to the same extent. Triterpen glycosides inhibited the biosynthesis of RNA at the stage of 14C-uridine in corporation into the nucleotide pool of the yeast cells.

Cells, Cultured↗

PubMed1997

Effect of depolymerized holothurian glycosaminoglycan (DHG) on tissue factor pathway inhibitor: in vitro and in vivo studies.

Depolymerized holothurian glycosaminoglycan (DHG) is a glycosaminoglycan extracted from the sea cucumber Stichopus japonicus Selenka. In previous studies, we demonstrated that DHG has antithrombotic and anticoagulant activities that are distinguishable from those of heparin and dermatan sulfate. In the present study, we examined the effect of DHG on the tissue factor pathway inhibitor (TFPI), which inhibits the initial reaction of the tissue factor (TF)-mediated coagulation pathway. We first examined the effect of DHG on factor Xa inhibition by TFPI and the inhibition of TF-factor VIIa by TFPI-factor Xa in in vitro experiments using human purified proteins. DHG increased the rate of factor Xa inhibition by TFPI, which was abolished either with a synthetic C-terminal peptide or with a synthetic K3 domain peptide of TFPI. In contrast, DHG reduced the rate of TF-factor VIIa inhibition by TFPI-factor Xa. Therefore, the effect of DHG on in vitro activity of TFPI appears to be contradictory. We then examined the effect of DHG on TFPI in cynomolgus monkeys and compared it with that of unfractionated heparin. DHG induced an increase in the circulating level of free-form TFPI in plasma about 20-fold when administered i.v. at 1 mg/kg. The prothrombin time (PT) in monkey plasma after DHG administration was longer than that estimated from the plasma concentrations of DHG. Therefore, free-form TFPI released by DHG seems to play an additive role in the anticoagulant mechanisms of DHG through the extrinsic pathway in vivo. From the results shown in the present work and in previous studies, we conclude that DHG shows anticoagulant activity at various stages of coagulation reactions, i.e., by inhibiting the initial reaction of the extrinsic pathway, by inhibiting the intrinsic Xase, and by inhibiting thrombin.

Animals↗

PubMed2004

The tryptophane residues of dimeric arginine kinase: roles of Trp-208 and Trp-218 in active site and conformation stability.

Roles of the two tryptophane residues of dimeric arginine kinase (AK) were individually investigated by site-directed mutagenesis. Both residues were fully conserved in the phosphogen kinase family and the mutant proteins were analyzed by enzyme kinetics, fluorescence spectroscopy, fluorescence quenching experiments, thermal stability and conformational stability. Our studies revealed that Trp-218 was located at the active site of AK and was the major fluorescence contributor (96.9%). Single replacement of this residue by alanine led to almost complete inactivation of the enzyme. In addition, a decrease in the melting temperature in differential scanning calorimetry (DSC) profiles and the equilibrium studies in guanidine hydrochloride (GdnHCl) denaturation after mutagenesis also suggested that Trp-218 takes part in stabilizing the conformational structure of AK. Although another tryptophane, Trp-208 was not located at the active sites, it may take part in maintaining the correct dimer conformation for catalysis. Replacement of this tryptophane by alanine decreased the activity to 70.3% and made it susceptible to heat and denaturants, such as GdnHCl. In addition, Trp-208 also seemed to play an important role in correct protein folding.

Animals↗

PubMed2026

Ossicle occurrence characteristics and related molecular mechanisms in the sea cucumber Apostichopus japonicus.

To investigate the morphogenetic pattern and molecular mechanism of ossicle formation in the sea cucumber Apostichopus japonicus, this study systematically examined the morphological development and temporal sequence of spicules using the NaClO maceration method, in-situ squash preparation and microscopic observation. Comparative transcriptome sequencing was performed between doliolaria and pentactula larvae to screen differentially expressed genes (DEGs) related to ossicles formation, followed by pathway enrichment analysis. The function of the candidate key gene papilin-like was verified using siRNA-mediated gene silencing. The results were as follows: 1) Ossicles of A. japonicus first appeared at the late auricularia stage, initiating as X-shaped ossicles at the base of the oral tentacles. The number of X-shaped ossicles increased dramatically during the doliolaria stage. X-shaped ossicles were gradually replaced by table-shaped and rosette-shaped ossicles at the pentactula stage, suggesting that X-shaped ossicles may differentiate into these two ossicle types. The morphology of table-shaped ossicles showed a "simple-complex-simple" pattern with development. 2) Key genes related to ossicles formation, including CA1, COL1A2, and papilin-like, were identified by transcriptome analysis. After papilin-like knockdown, abnormal morphologies were observed in table-shaped ossicles of 1-year-old A. japonicus, such as spine-like protrusions on the outer margin of the disc and loss of table legs, confirming its crucial roles in maintaining ossicle morphology. This study clarified the morphological development pattern of ossicles in A. japonicus and identified a key regulatory gene (papilin-like) involved in ossicle morphogenesis, providing preliminary insights into the underlying molecular regulatory mechanism. These findings enrich our understanding on ossicles formation in echinoderms, and provide important morphological and molecular biological information for further studies on the developmental mechanism of ossicles in A. japonicus.

Animals↗

PubMed2026

Evolutionary conservation and adaptability of cholecystokinin neuropeptide signaling in the sea cucumber Apostichopus japonicus.

BACKGROUND: Food ingestion is fundamental for animal survival and growth, with the cessation of feeding upon nutrient fulfillment being tightly regulated by a variety of satiety factors. Notably, sulfakinin/cholecystokinin (SK/CCK)-type neuropeptide signaling has been identified as an inhibitory regulator of food intake across the animal kingdom. However, its regulatory mechanism in feeding in deuterostome invertebrates remains unclear. Here, we characterized SK/CCK-type signaling in a deuterostome invertebrate, the sea cucumber Apostichopus japonicus (phylum Echinodermata). RESULTS: A single SK/CCK-type precursor in A. japonicus generates two mature peptides (AjSK/CCK1, AjSK/CCK2) that activate a shared receptor (AjSK/CCKR), triggering Ca2+ mobilization via the Gαq-dependent pathway and extracellular signal regulated kinase 1/2 (ERK1/2) phosphorylation. Both peptides induce dose-dependent contraction of longitudinal muscles, while AjSK/CCK2 additionally elicits sustained contraction of the posterior intestine, an effect absent in other gut regions. Long-term injection of both peptides reduces food intake and significantly downregulates orexin-type neuropeptide genes (AjOrexin1P, AjOrexin2P) in the circumoral nerve ring (CNR) and intestine. CONCLUSIONS: Unlike mammals, where CCK inhibits feeding by contracting the pyloric sphincter to delay gastric emptying, SK/CCK-type peptides in sea cucumbers exert their anorexic effect in part by selectively contracting the posterior intestine, thereby inhibiting intestinal emptying. This divergence in action sites highlights the evolutionary adaptability of SK/CCK-type signaling as a conserved inhibitory regulator of feeding across bilaterian animals. Elucidating these mechanisms in the economically important A. japonicus may inform development of appetite-promoting agents for sustainable aquaculture.

Animals↗

PubMed2025

Lytic coelomocyte death is tuned by cleavage but not phosphorylation of MLKL in echinoderms.

Lytic cell death including necroptosis and pyroptosis is induced by mixed lineage kinase domain-like protein (MLKL) phosphorylation and inflammatory caspase specific cleavage Gasdermins in higher mammals, respectively. In this study, we identified a novel MLKL homolog containing a tetrapeptide recognition motif (14-LVAD-17) of inflammatory caspase from Apostichopus japonicus,which was absent of Gasdermins member by genome screening. Functional analysis revealed that AjMLKL was involved in the regulation of Vibrio splendidus AJ01 infection induced lytic coelomocyte death in a cleavage-dependent manner, but not through RIPK3-dependent phosphorylation as mammals. Mechanistically, the activated form of cysteine-aspartic specific proteases-1 (AjCASP-1) bound to the tetrapeptide site of AjMLKL and cleaved it at Asp17. Cleaved AjMLKL18-491 displayed higher binding affinities towards phosphatidylinositol phosphate and cardiolipin compared to those of un-cleaved form. In addition, cleaved AjMLKL18-491 exerted stronger ability in disrupting the membrane integrity of liposome. More importantly, AjMLKL18-491 caused a large non-selective ionic coelomocyte pore and could directly kill the invasive AJ01. Moreover, activation of inflammatory AjCASP-1 was further found to be dependent on forming an inflammasome-like complex via CASc domain of AjCASP-1 and the N-terminal Ig domains of internalized AjNLRC4. All our results proved first evidence that lytic cell death was activated through MLKL cleavage, not MLKL phosphorylation in echinoderm, which offered insights into the functional, evolutionary mechanisms of lytic cell death in invertebrates.

Animals↗

PubMed2006

[The ultrastructural patterns of germinal and yolk granules in oocytes and embryonic cells of the holothurian Apostichopus japonicus].

The yolk germinal granules in oocytes and embryonic cells of Apostichopus japonicus were studied by transmission electron microscopy. Analysis of the features of synthesis and utilization of yolk granules made it possible to reveal ultrastructural criteria to distinguish between granules of the forming and utilized yolk, and germinal granules. Based on these findings, the authors suppose that identification of germ plasm elements in oocytes and embryonic cells of A. japonicus is quite possible with ultrastructural analysis only, and does not require utilizing molecular markers.

Animals↗

PubMed2006

[The ultrastructural patterns of germinal and yolk granules in oocytes and embryonic cells of the holothurian Apostichopus japonicus].

Animals↗