Search results for "Holothuria"
showing 10 items of 25 documents
Preferential assimilation of seagrass detritus by two coexisting Mediterranean sea cucumbers: Holothuria polii and Holothuria tubulosa
2019
Abstract Holothuria polii and Holothuria tubulosa are two of the most commercially exploited sea cucumbers of the Mediterranean Sea. As deposit-feeders, they represent an important component of the benthic community. Hence, knowledge of their feeding behaviour is crucial for understanding their function in terms of benthic ecology and sediment dynamics. Using information obtained from stable isotope analysis, the food selectivity/assimilation, temporal variations in diet and trophic niche of H. polii and H. tubulosa were investigated. Analysis of carbon and nitrogen isotopic ratios in body wall tissue showed a preferential assimilation of seagrass detritus among multiple food sources, with …
Cytotoxic activity of Holothuria tubulosa (Echinodermata) coelomocytes.
2017
Abstract The immune system of marine invertebrates, in particular that of holothurians, still requires further study. Our research showed that coelomocyte cells contained in the coelomic fluid of the sea cucumber, Holothuria tubulosa, are able to lyse, in vitro, red blood cells in rabbits and sheep. A plaque-forming assay showed spherule cells to be the effector cells, able to release cytotoxic molecules after xenogenic cell contact. The coelomocyte lysate supernatant, analysed by polyacrylamide gel electrophoresis overlay technique, using rabbit and sheep erythrocytes, showed two different haemolytic protein patterns: one calcium dependent and the other calcium independent. The fractions o…
Cytotoxic Potential of the Coelomic Fluid Extracted from the Sea Cucumber Holothuria tubulosa against Triple-Negative MDA-MB231 Breast Cancer Cells
2019
Growing evidence has demonstrated that the extracts of different holothurian species exert beneficial effects on human health. Triple negative breast cancers (TNBC) are highly malignant tumors that present a poor prognosis due to the lack of effective targeted therapies. In the attempt to identify novel compounds that might counteract TNBC cell growth, we studied the effect of the exposure of the TNBC cell line MDA-MB231 to total and filtered aqueous extracts of the coelomic fluid obtained from the sea cucumber Holoturia tubulosa, a widespread species in the Mediterranean Sea. In particular, we examined cell viability and proliferative behaviour, cell cycle distribution, apoptosis, autophag…
Citocentrifugación como un método adicional para estudiar celomitos de equinodermos: un enfoque comparativo que combina células vivas, preparaciones …
2021
Abstract Introduction: Echinoderm coelomocytes have traditionally been investigated through a morphological approach using light microscopy, which relies on the idea of constant cell shape as a stable character. However, this can be affected by biotic or abiotic conditions. Objective: To analyze if the consistency in cell morphology offered by the cytocentrifugation method, might be used as a convenient tool to study echinoderm coelomocytes. Methods: Cells of Echinaster (Othilia) brasiliensis (Asteroidea), Holothuria (Holothuria) tubulosa (Holothuroidea), Eucidaris tribuloides, Arbacia lixula, Lytechinus variegatus, and Echinometra lucunter (Echinoidea) were spread on microscope slides by c…
The hemolysin-producer coelomocytes in Holothuria polii
1988
Using sodium metrizoate discontinuous gradients, two hemolysin-producer amebocyte populations have been separated from total circulating Holothuria polii coelomocytes. The amebocytes of population 1 are responsible for the production of the calcium-dependent and temperature-labile hemolysin, whereas those of population 2 produce the calcium-independent and temperature-stable one. The intracytoplasmic hemolysins were evidenced also by immunofluorescence. Petaloid and filipodial amebocytes were the only positive cell types.
Echinoderm Antimicrobial Peptides
2016
Abstract Antimicrobial peptides (AMPs) are widely expressed in organisms and have been linked to innate and acquired immunity in vertebrates. These compounds are constitutively expressed from different cellular types to interact directly with infectious agents and/or modulate immunoreactions. In invertebrates, including echinoderms, which lack a vertebrate-type adaptive immune system, AMPs represent the major humoral defense system against infection, showing a diverse spectrum of action mechanisms, most of them related to plasma membrane disturbance and lethal alteration of microbial integrity. Here, we summarize the knowledge of AMPs in echinoderms as Strongylocins identified in the sea ur…
A new neuraminic acid derivative and three types of glycopeptides isolated from the Cuvierian tubules of the sea cucumber Holothuria forskali
1973
The Cuvierian tubules of Holothuria forskali Della Chiaje, a sea cucumber found in the Adriatic Sea, were investigated with regard to their carbohydrate moieties. From a Pronase digest of these tubules three types of carbohydrate units were isolated and characterized. 1. A high-molecular-weight glycopeptide fraction was shown to contain sulphated polyfucose, galactosamine, a uronic acid and a previously unknown neuraminic acid derivative. The sulphate was shown by i.r. analysis to be present as an O-ester. The carbohydrate unit was linked O-glycosidically to threonine and serine residues in the polypeptide chain. The hitherto unknown neuraminic acid derivative (Hf-neuraminic acid) was resis…
Naturally occurring hemolysins in the coelomic fluid of Holothuria polii delle chiaie (Echinodermata).
1979
Abstract The coelomic fluid of Holothuria polii D.Ch contains hemolytic activity against erythrocytes of several vertebrate species. The hemolytic potency depends upon calcium ion concentration and varies according to erythrocyte source and cell number in the reaction mixture. Absorption experiments with formalinized rabbit erythrocytes suggest that hemolytic activity is not specific. Its heat lability, water insolubility at low pH values, and sensitivity to proteolytic enzymes suggest that hemolytic activity resides in protein molecules. The activity, maximal in alkaline media, appears to depend up time and temperature.
Inhibitory activity of sphingomyelin on hemolytic activity of coelomic fluid of Holothuria polii (echinodermata)
1987
Abstract The hemolytic activity of coelomic fluid from Holothuria polii is specifically inhibited by sphingomyelin. This phospholipid is the constituent of the membrane which probably interacts with the hemolysin thereby leading to the lysis.
Studies on Holothuriapolii (echinodermata) coelomocyte lysate II. Isolation of coelomocyte hemolysins
1988
The lytic activity of the Holothuria polii coelomocyte lysate resides in two electrophoretically distinct hemolysins identified as He1 and He2. He1 represents the calcium dependent, heat-labile component whereas He2 is calcium independent and heat-stable. The two hemolysins share serological identity. Both hemolysins appear as single protein molecules of 80KDa molecular weight by SDS-PAGE and transblotting analysis under non-reducing conditions. However under reducing conditions, they are doublets of 76 and 80KDa molecular weight. The hypothesis that the two hemolysins could be isoforms is discussed.