Bright spots in the darkness of cancer: A review of starfishes-derived compounds and their anti-tumor action

The fight against cancer represents a great challenge for researchers and, for this reason, the search for new promising drugs to improve cancer treatments has become inevitable. Oceans, due to their wide diversity of marine species and environmental conditions have proven to be precious sources of potential natural drugs with active properties. As an example, in this context several studies performed on sponges, tunicates, mollusks, and soft corals have brought evidence of the interesting biological activities of the molecules derived from these species. Also, echinoderms constitute an important phylum, whose members produce a huge number of compounds with diverse biological activities. In particular, this review is the first attempt to summarize the knowledge about starfishes and their secondary metabolites that exhibited a significant anticancer effect against different human tumor cell lines. For each species of starfish, the extracted molecules, their effects, and mechanisms of action are described

The Role of Spatial Exploration and Territoriality in Establishing Gilthead Seabream (Sparus aurata) Hierarchies, and Their Effects upon Underlying Stress Physiology

Territoriality, spatial exploration and social hierarchy are strictly related behaviors in gregarious fishes, and are often under-appreciated in farms where the individuals are confined within crowded spaces. In this study, we investigated the role of spatial exploration, elucidating the importance of time upon forming the social organization, and the role of the territoriality in gilthead seabream (Sparus aurata), using two experimental approaches. In the first approach, three fish were placed sequentially in the aquarium with an interval of two days (sequential model), while in the second (simultaneous model), two fish were simultaneously placed in an aquarium divided by a barrier which was removed after a certain period of time. To study the effect of social stress and spatial perception in the two models, we monitored behavior (aggressive acts and feeding priority), integrated with the evaluation of physiological and cellular stress parameters, such as phagocytosis, cortisol, glucose, and blood osmolarity levels. After the establishment of the social hierarchy in the "sequential model", we observed that the levels of cortisol and an immunological cell-mediated marker were higher in subordinate individuals than in the dominant ones. We observed a different modulation of phagocytic activity in peritoneal cavity cells between dominant and subordinates, demonstrating that social stress acts upon immune response. Differently from the first model, no behavioral, physiological, or phagocytic differences were found between the two fish involved in the simultaneous model, where both fish acted as co-dominants, defending their territory. The study achieved a deeper understanding of the role of spatial exploration, territorial dominance and intraspecific interaction in gilthead seabream, and elucidated the link between them and physiological stress indicators. The results highlight aspects of interest to the aquaculture industry, showing the importance of a greater focus on rearing conditions, finding solutions to mitigate crowding effects and promoting the quality of aquacultural products

Hemocyte types and some plasmatic properties of two edible crabs Cancer borealis and Cancer pagurus

Cancer pagurus and Cancer borealis and are edible crabs produced by economically relevant aquaculture. In this study the hemocytes and some plasmatic parameters of Cancer borealis and Cancer pagurus were examined. The cell features of the hemocytes were observed using light and scanning electron microscopy (SEM). Granulocytes, semigranulocytes and hyalinocytes were mainly identified on the basis of size, presence/absence and quantity of the cytoplasmic granules and the nucleus-to-citoplasma (N/C) ratio. SEM observations were useful for disclosing the surface features of these cells, and the same characteristics were found in both crab species. A smooth surface distinguishes elongated hyalinocytes and a rough texture the irregular surface of spherical/ovoid granular cells. Total (THC) and differential hemocyte counts (DHC) were performed, and the differences between the two crab species were disclosed. Also we were valuated pH and osmolarity values, agglutinating activity and different protein contents of the hemolymp

Seabream (Sparus aurata) long-term dominant-subordinate interplay affects phagocytosis by peritoneal cavity cells

Fish are sensitive to stressful conditions that affect their innate immune systems and increase their susceptibility to diseases. We examined the social stress of paired gilthead seabream (Sparus aurata). Social hierarchies (dominant/subordinate) were characterised by behavioural changes, such as \u201caggressiveness\u201d and \u201cfeeding order\u201d; hierarchical positions were established within an hour of exposure to social stress and remained unchanged for approximately 1 year. To characterise physiological stress, we measured blood plasma levels of cortisol, glucose, and lactate as well as osmolarity and observed that the levels of these stress markers were higher in subordinate individuals than in dominant ones. The discriminant analysis revealed a separation of the subordinate fish groups, and at 15 days, a significant separation among groups was observed. Moreover, diminished phagocytic and respiratory burst activities revealed that social stress appeared to affect the cellular innate immune response of the subordinate specimens. Finally, to examine the effect of cortisol on phagocytosis, peritoneal cavity cells were treated in vitro, and an inhibitory effect was observed

The use of an integrative approach to identify coelomocytes in three species of the genus Holothuria (Echinodermata)

Coelomocytes in the Holothuroidea are traditionally identified according to their morphology through light, fluorescence, or electron microscopy. Former studies have typically used only one method, with few works combining two or more approaches. Studies using cytocentrifugation to study these cells are scarcer. Thus, for the first time, an integrative approach was used to compare coelomocytes in Holothuroidea. This approach consisted of living and stained cells, scanning electron microscopy (for spherule cells), and accurate morphometric analyses. Specifically, we used specimens of Holothuria grisea, Holothuria arenicola, and Holothuria tubulosa to test whether cytocentrifugation could be valuable in comparative studies with coelomocytes, whether an integrative approach could help to understand spherule cell diversity, and whether closely related species, even those having distinct geographic distributions and ecological requirements, would have a similar population of coelomocytes. Our results showed seven distinct cell types in these species, including phagocytes, fusiform cells, morula cells, acidophilic spherulocytes, spherulocytes, progenitor cells, and crystal cells. Total and differential cell counts, along with morphometric parameters, were similar among species. Morphometric analyses of spherule cells revealed consistent differences among the diameter of their cytoplasmic spherules, as well as a set of different morphotypes in acidophilic spherulocytes and spherulocytes. Cytospin preparations proved to be quite useful because they provided constant morphological and morphometric data, allowing accurate identification of the cell types and comparisons among species. Moreover, this study highlighted (1) that the spherule diameter is a good parameter to separate spherule cells and (2) a putative maturation process to acidophilic spherulocytes and spherulocytes. Lastly, we showed that the cells of these species are very similar, regardless of their geographic distribution and ecology. Thus, our work contributes to a better understanding of the coelomocytes in Holothuria, a genus with a wide geographic distribution. The present study may be useful to establish these species as important model organisms, as well as bring insights into the functions of coelomocytes

Differential expression of two glucocorticoid receptors in seabass (teleost fish) head kidney after exogeneous cortisol inoculation

Stressful conditions include a prompt release of corticosteroid hormones which can mediate gene expression through glucocorticoid receptors (GR). Since two seabass (Dicentrarchus labrax) GRs have been cloned and sequenced from peritoneal cavity cells (DlGR1) and liver (DlGR2), a comparative amino acid sequence analysis that included Haplochromis burtoni HbGRs, was carried out and homologies disclosed. The DlGR1 and DlGR2 deduced aminoacid sequences showed 61% identity (I) and 70% similarity (S). Moreover, DlGR2 was similar to HbGR2b (69% I, 73% S), and the DlGR1 to HbGR1 (72% I, 78% S). In addition, we examined the expression of the DlGRs after exogeneous cortisol inoculation into the peritoneal cavity, mimicking stress effects. At various times after the administration (3 h, 24 h, 1 week), gene expressions was evaluated in head kidney by real-time PCR. In addition, immunoblotting and densitometry analyses were performed with anti- DlGR1 antibodies. Although sea bass head kidney expressed both DlGR1 and DlGR2 they were differentially modulated by intraperitoneal implant of exogeneous cortisol

Cytocentrifugation as an additional method to study echinoderm coelomocytes: A comparative approach combining living cells, stained preparations, and energy-dispersive x-ray spectroscopy

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 cytocentrifugation, stained, and analyzed through light microscopy. Additionally, fluorescence microscopy, scanning electron microscopy, and energy-dispersive x-ray spectroscopy were applied to cytospin preparations, to complement the analysis of granular and colorless spherulocytes of Eucidaris tribuloides. Results: Altogether, 11 cell types, including phagocytes, spherulocytes, vibratile cells, and progeni-tor cells were identified in the samples analyzed. The granular spherulocyte, a newly-described cell type, was observed in all Echinoidea and was very similar to the acidophilic spherulocytes of Holothuria (Holothuria) tubulosa. Conclusions: Cytocentrifugation proved to be versatile, either as the main method of investigation in stained preparations, or as a framework on which other procedures may be performed. Its ability to maintain a constant morphology allowed accurate correspondence between live and fixed/stained cells, differentiation among similar spherulocytes as well as comparisons between similar cells of Holothuroidea and Echinoidea

Effects of diclofenac on the gametes and embryonic development of Arbacia lixula

Diclofenac (DCF), a non-steroidal anti-inflammatory drug (NSAID), is among the main pollutants of aquatic environments. Nevertheless, even if several authors evaluated its effects on marine organisms, no work has ever analysed its impact on the sea urchin Arbacia lixula. The purpose of this study was to analyse, for the first time, the impact of DCF at different concentrations (50 mg/l, 5 mg/l, 0.5 mg/l, 0.05 mg/l) on A. lixula embryos and gametes to indicate possible safe minimum levels of release of this drug in marine environments. Our results showed significant concentration-dependent effects on embryonic development (decrease in the number of developed embryos and increase in the quantity of degenerated eggs) and significant levels of bioaccumulation at DCF concentrations of 50 mg/l in both gametes and embryos. DCF showed a significant impact on the fertilisation of A. lixula due to its effects on gametes, confirming the possibility of environmental risk and highlighting the need to improve wastewater treatment and drug disposal processes

Sucrose phosphate synthase activity and the co-ordination of carbon partitioning during sucrose and amino acid accumulation in desiccation-tolerant leaf material of the C4 resurrection plant Sporobolus stapfianus during dehydration.

Both sucrose and amino acids accumulate in desiccation-tolerant leaf material of the C(4) resurrection plant, Sporobolus stapfianus Gandoger (Poaceae). The present investigation was aimed at examining sucrose phosphate synthase (SPS) activity and various metabolic checkpoints involved in the co-ordination of carbon partitioning between these competing pathways during dehydration. In the initial phase of dehydration, photosynthesis and starch content declined to immeasurable levels, whilst significant increases in hexose sugars, sucrose, and amino acids were associated with concomitant significant increases in SPS and pyruvate kinase (PK) activities, and maximal activity levels of phosphoenolpyruvate carboxylase (PEPCase), NADP-dependent isocitrate dehydrogenase (NADP-ICDH), and NADH-dependent glutamate synthase (NADH-GOGAT). The next phase of dehydration was characterized by changes in metabolism coinciding with net hexose sugar phosphorylation. This phase was characterized by a further significant increase in sucrose accumulation, with increased rates of net sucrose accumulation and maximum rates of SPS activity measured under both saturating and limiting (inhibitory) conditions. SPS protein was also increased. The stronger competitive edge of SPS for carbon entering glycolysis during hexose phosphorylation was also demonstrated by the further decrease in respiration and the simultaneous, significant decline in both PEPCase and PK activities. A decreased anabolic demand for 2-oxoglutarate (2OG), which remained constant, was shown by the co-ordinated decrease in GOGAT. It is proposed that the further increase in amino acids in this phase of dehydration may be in part attributable to the breakdown of insoluble proteins