Preparation of Jellyfish Mucin.

A mucin-type glycoprotein extracted from various species of jellyfish (JF) is named qniumucin (Q-mucin). Compared with general mucins, most of which are from mammals including humans, Q-mucin can be collected on a relatively large scale with high yield. Owing to its simple structure with low heterogeneity, Q-mucin has a potential to be developed into material mucins which opens various applications valuable to humans. On the basis of our present knowledge, here, we describe our protocol for the extraction of Q-mucin, which can be extracted from any JF species worldwide. Experimental protocols to identify the structure of Q-mucin are also introduced.

The branched mitochondrial respiratory chain from the jellyfish Stomolophus sp2 as a probable adaptive response to environmental changes.

During their long evolutionary history, jellyfish have faced changes in multiple environmental factors, to which they may selectively fix adaptations, allowing some species to survive and inhabit diverse environments. Previous findings have confirmed the jellyfish's ability to synthesize large ATP amounts, mainly produced by mitochondria, in response to environmental challenges. This study characterized the respiratory chain from the mitochondria of the jellyfish Stomolophus sp2 (previously misidentified as Stomolophus meleagris). The in-gel activity from isolated jellyfish mitochondria confirmed that the mitochondrial respiratory chain contains the four canonical complexes I to IV and F0F1-ATP synthase. Specific additional activity bands, immunodetection, and mass spectrometry identification confirmed the occurrence of four alternative enzymes integrated into a branched mitochondrial respiratory chain of Stomolophus sp2: an alternative oxidase and three dehydrogenases (two NADH type II enzymes and a mitochondrial glycerol-3-phosphate dehydrogenase). The analysis of each transcript sequence, their phylogenetic relationships, and each protein's predicted models confirmed the mitochondrial alternative enzymes' identity and specific characteristics. Although no statistical differences were found among the mean values of transcript abundance of each enzyme in the transcriptomes of jellyfish exposed to three different temperatures, it was confirmed that each gene was expressed at all tested conditions. These first-time reported enzymes in cnidarians suggest the adaptative ability of jellyfish's mitochondria to display rapid metabolic responses, as previously described, to maintain energetic homeostasis and face temperature variations due to climate change.

Digestive glycosidases from cannonball jellyfish (Stomolophus sp. 2): identification and temporal-spatial variability.

Jellyfish are economically important organisms in diverse countries, carnivorous organisms that consume various prey (crustaceans, mollusks, bivalves, etc.) and dissolved carbohydrates in marine waters. This study was focused on detecting and quantifying the activity of digestive glycosidases from the cannonball jellyfish (Stomolophus sp. 2) to understand carbohydrate digestion and its temporal-spatial variation. Twenty-three jellyfish gastric pouches were collected in 2015 and 2016 in the Gulf of California in three localities (Las Guásimas, Hermosillo, and Caborca). Nine samples were in intra-localities from Las Guásimas. Chitinase (Ch), ß-glucosidase (ß-glu), and ß-N-acetylhexosaminidase (ß-NAHA) were detected in the gastric pouches. However, cellulase, exoglucanase, α-amylase, polygalacturonase, xylanase, and κ-carrageenase were undetected. Detected enzymes showed halotolerant glycolytic activity (i = 0-4 M NaCl), optimal pH, and temperature at 5.0 and 30-50 °C, respectively. At least five ß-glucosidase and two ß-N-acetylhexosaminidase were detected using zymograms; however, the number of proteins with chitinase activity is not precise. The annual variation of cannonball jellyfish digestive glycosidases from Las Guásimas between 2015-2016 does not show significant differences despite the difference in phytoplankton measured as chlorophyll α (1.9 and 3.4 mg/m3, respectively). In the inter-localities, the glycosidase activity was statistically different in all localities, except for ß-N-acetylhexosaminidase activity between Caborca and Hermosillo (3,009.08 ± 87.95 and 3,101.81 ± 281.11 mU/g of the gastric pouch, respectively), with chlorophyll α concentrations of 2.6, 3.4 mg/m3, respectively. For intra-localities, the glycosidase activity did not show significant differences, with a mean chlorophyll α of 1.3 ± 0.1 mg/m3. These results suggest that digestive glycosidases from Stomolophus sp. 2 can hydrolyze several carbohydrates that may belong to their prey or carbohydrates dissolved in marine waters, with salinity over ≥ 0.6 M NaCl and diverse temperature (4-80 °C) conditions. Also, chlorophyll α is related to glycosidase activity in both seasons and inter-localities, except for chitinase activity in an intra-locality (Las Guásimas).

Jellyfish detritus supports niche partitioning and metabolic interactions among pelagic marine bacteria.

BACKGROUND: Jellyfish blooms represent a significant but largely overlooked source of labile organic matter (jelly-OM) in the ocean, characterized by a high protein content. Decaying jellyfish are important carriers for carbon export to the ocean's interior. To accurately incorporate them into biogeochemical models, the interactions between microbes and jelly-OM have yet to be fully characterized. We conducted jelly-OM enrichment experiments in microcosms to simulate the scenario experienced by the coastal pelagic microbiome after the decay of a jellyfish bloom. We combined metagenomics, endo- and exo-metaproteomic approaches to obtain a mechanistic understanding on the metabolic network operated by the jelly-OM degrading bacterial consortium. RESULTS: Our analysis revealed that OM released during the decay of jellyfish blooms triggers a rapid shuffling of the taxonomic and functional profile of the pelagic bacterial community, resulting in a significant enrichment of protein/amino acid catabolism-related enzymes in the jelly-OM degrading community dominated by Pseudoalteromonadaceae, Alteromonadaceae and Vibrionaceae, compared to unamended control treatments. In accordance with the proteinaceous character of jelly-OM, Pseudoalteromonadaceae synthesized and excreted enzymes associated with proteolysis, while Alteromonadaceae contributed to extracellular hydrolysis of complex carbohydrates and organophosphorus compounds. In contrast, Vibrionaceae synthesized transporter proteins for peptides, amino acids and carbohydrates, exhibiting a cheater-type lifestyle, i.e. benefiting from public goods released by others. In the late stage of jelly-OM degradation, Rhodobacteraceae and Alteromonadaceae became dominant, growing on jelly-OM left-overs or bacterial debris, potentially contributing to the accumulation of dissolved organic nitrogen compounds and inorganic nutrients, following the decay of jellyfish blooms. CONCLUSIONS: Our findings indicate that specific chemical and metabolic fingerprints associated with decaying jellyfish blooms are substantially different to those previously associated with decaying phytoplankton blooms, potentially altering the functioning and biogeochemistry of marine systems. We show that decaying jellyfish blooms are associated with the enrichment in extracellular collagenolytic bacterial proteases, which could act as virulence factors in human and marine organisms' disease, with possible implications for marine ecosystem services. Our study also provides novel insights into niche partitioning and metabolic interactions among key jelly-OM degraders operating a complex metabolic network in a temporal cascade of biochemical reactions to degrade pulses of jellyfish-bloom-specific compounds in the water column. Video Abstract.

The Zooxanthellate Jellyfish Holobiont Cassiopea andromeda, a Source of Soluble Bioactive Compounds.

Cassiopea andromeda (Forsskål, 1775), commonly found across the Indo-Pacific Ocean, the Red Sea, and now also in the warmest areas of the Mediterranean Sea, is a scyphozoan jellyfish that hosts autotrophic dinoflagellate symbionts (family Symbiodiniaceae). Besides supplying photosynthates to their host, these microalgae are known to produce bioactive compounds as long-chain unsaturated fatty acids, polyphenols, and pigments, including carotenoids, with antioxidant properties and other beneficial biological activities. By the present study, a fractionation method was applied on the hydroalcoholic extract from two main body parts (oral arms and umbrella) of the jellyfish holobiont to obtain an improved biochemical characterization of the obtained fractions from the two body parts. The composition of each fraction (i.e., proteins, phenols, fatty acids, and pigments) as well as the associated antioxidant activity were analyzed. The oral arms proved richer in zooxanthellae and pigments than the umbrella. The applied fractionation method was effective in separating pigments and fatty acids into a lipophilic fraction from proteins and pigment-protein complexes. Therefore, the C. andromeda-dinoflagellate holobiont might be considered as a promising natural source of multiple bioactive compounds produced through mixotrophic metabolism, which are of interest for a wide range of biotechnological applications.

Pharmacoinformatic Investigation of Silymarin as a Potential Inhibitor against Nemopilema nomurai Jellyfish Metalloproteinase Toxin-like Protein.

Jellyfish stings pose a major threat to swimmers and fishermen worldwide. These creatures have explosive cells containing one large secretory organelle called a nematocyst in their tentacles, which contains venom used to immobilize prey. Nemopilema nomurai, a venomous jellyfish belonging to the phylum Cnidaria, produces venom (NnV) comprising various toxins known for their lethal effects on many organisms. Of these toxins, metalloproteinases (which belong to the toxic protease family) play a significant role in local symptoms such as dermatitis and anaphylaxis, as well as systemic reactions such as blood coagulation, disseminated intravascular coagulation, tissue injury, and hemorrhage. Hence, a potential metalloproteinase inhibitor (MPI) could be a promising candidate for reducing the effects of venom toxicity. For this study, we retrieved the Nemopilema nomurai venom metalloproteinase sequence (NnV-MPs) from transcriptome data and modeled its three-dimensional structure using AlphaFold2 in a Google Colab notebook. We employed a pharmacoinformatics approach to screen 39 flavonoids and identify the most potent inhibitor against NnV-MP. Previous studies have demonstrated the efficacy of flavonoids against other animal venoms. Based on our analysis, Silymarin emerged as the top inhibitor through ADMET, docking, and molecular dynamics analyses. In silico simulations provide detailed information on the toxin and ligand binding affinity. Our results demonstrate that Silymarin's strong inhibitory effect on NnV-MP is driven by hydrophobic affinity and optimal hydrogen bonding. These findings suggest that Silymarin could serve as an effective inhibitor of NnV-MP, potentially reducing the toxicity associated with jellyfish envenomation.

Jellyfishes-Significant Marine Resources with Potential in the Wound-Healing Process: A Review.

The wound-healing process is a significant area of interest in the medical field, and it is influenced by both external and patient-specific factors. The aim of this review paper is to highlight the proven wound-healing potential of the biocompounds found in jellyfish (such as polysaccharide compounds, collagen, collagen peptides and amino acids). There are aspects of the wound-healing process that can benefit from polysaccharides (JSPs) and collagen-based materials, as these materials have been shown to limit exposure to bacteria and promote tissue regeneration. A second demonstrated benefit of jellyfish-derived biocompounds is their immunostimulatory effects on growth factors such as (TNF-α), (IFN-γ) and (TGF), which are involved in wound healing. A third benefit of collagens and polysaccharides (JSP) is their antioxidant action. Aspects related to chronic wound care are specifically addressed, and within this general theme, molecular pathways related to tissue regeneration are explored in depth. Only distinct varieties of jellyfish that are specifically enriched in the biocompounds involved in these pathways and live in European marine habitats are presented. The advantages of jellyfish collagens over mammalian collagens are highlighted by the fact that jellyfish collagens are not considered transmitters of diseases (spongiform encephalopathy) or various allergic reactions. Jellyfish collagen extracts stimulate an immune response in vivo without inducing allergic complications. More studies are needed to explore more varieties of jellyfish that can be exploited for their biocomponents, which may be useful in wound healing.

Characterization of the Biophysical Properties and Cell Adhesion Interactions of Marine Invertebrate Collagen from Rhizostoma pulmo.

Collagen is the most ubiquitous biomacromolecule found in the animal kingdom and is commonly used as a biomaterial in regenerative medicine therapies and biomedical research. The collagens used in these applications are typically derived from mammalian sources which poses sociological issues due to widespread religious constraints, rising ethical concern over animal rights and the continuous risk of zoonotic disease transmission. These issues have led to increasing research into alternative collagen sources, of which marine collagens, in particular from jellyfish, have emerged as a promising resource. This study provides a characterization of the biophysical properties and cell adhesion interactions of collagen derived from the jellyfish Rhizostoma pulmo (JCol). Circular dichroism spectroscopy and atomic force microscopy were used to observe the triple-helical conformation and fibrillar morphology of JCol. Heparin-affinity chromatography was also used to demonstrate the ability of JCol to bind to immobilized heparin. Cell adhesion assays using integrin blocking antibodies and HT-1080 human fibrosarcoma cells revealed that adhesion to JCol is primarily performed via ß1 integrins, with the exception of α2ß1 integrin. It was also shown that heparan sulfate binding plays a much greater role in fibroblast and mesenchymal stromal cell adhesion to JCol than for type I mammalian collagen (rat tail collagen). Overall, this study highlights the similarities and differences between collagens from mammalian and jellyfish origins, which should be considered when utilizing alternative collagen sources for biomedical research.

Identification and characterization of the key lethal toxin from jellyfish Cyanea nozakii.

Jellyfish Cyanea nozakii venom is a complex mixture of various toxins, most of which are proteinous biological macromolecules and are considered to be responsible for clinical symptoms or even death after a severe sting. Previous transcriptome and proteome analysis identified hundreds of toxins in the venom, including hemolysins, C-type lectin, phospholipase A2, potassium channel inhibitor, metalloprotease, etc. However, it is not clear which toxin in the venom plays the most important role in lethality. Herein, we isolated the key lethal toxin (Letoxcn) from jellyfish Cyanea nozakii using anion exchange chromatography, size-exclusion chromatography, and cation exchange chromatography. The molecular weight of Letoxcn is ∼50 kDa with the N-terminal sequences of QADAEKVNLPVGVCV. Peptide mass fingerprinting analysis of Letoxcn shows that it may have some motifs of phospholipase, metalloproteinase, thrombin-like enzyme, potassium channel toxin, etc. However, only metalloproteinase activity but no hemolytic, PLA2, or blood coagulation activity was observed from in vitro toxicity analysis. Overall, this study uncovered and characterized the key lethal toxin in the venom of jellyfish Cyanea nozakii, which will not only help to reveal the molecule mechanism of the lethality, but also develop effective treatment like antivenom for this jellyfish sting in the future.

Inhibition of Nematocyst Discharge from Pelagia noctiluca (Cnidaria: Scyphozoa)-Prevention Measures against Jellyfish Stings.

Pelagia noctiluca stings are common in Mediterranean coastal areas and, although the venom is non-lethal, they are painful. Due to its high toxicity and abundance, P. noctiluca is considered a target species for the focus of research on active ingredients to reduce the symptoms of its sting. To determine the effect of 31 substances and formulations on nematocyst discharge, we performed three tests: (1) screening of per se discharge activator solutions, (2) inhibitory test with nematocyst chemical stimulation (5% acetic acid) and (3) inhibitory test quantifying the hemolytic area. Ammonia, barium chloride, bleach, scented ammonia, carbonated cola, lemon juice, sodium chloride and papain triggered nematocyst discharge. All of them were ruled out as potential inhibitors. Butylene glycol showed a reduction in nematocyst discharge, while the formulations of 10% lidocaine in ethanol, 1.5% hydroxyacetophenone in distilled water + butylene glycol, and 3% Symsitive® in butylene glycol inhibited nematocyst discharge. These last results were subsequently correlated with a significant decrease in hemolytic area in the venom assays versus seawater, a neutral solution. The presented data represent a first step in research to develop preventive products for jellyfish stings while at the same time attempting to clarify some uncertainties about the role of various topical solutions in P. noctiluca first-aid protocols.

A novel endocast technique providing a 3D quantitative analysis of the gastrovascular system in Rhizostoma pulmo: An unexpected through-gut in cnidaria.

The investigation of jellyfish gastrovascular systems mainly focused on stain injections and dissections, negatively affected by thickness and opacity of the mesoglea. Therefore, descriptions are incomplete and data about tridimensional structures are scarce. In this work, morphological and functional anatomy of the gastrovascular system of Rhizostoma pulmo (Macri 1778) was investigated in detail with innovative techniques: resin endocasts and 3D X-ray computed microtomography. The gastrovascular system consists of a series of branching canals ending with numerous openings within the frilled margins of the oral arms. Canals presented a peculiar double hemi-canal structure with a medial adhesion area which separates centrifugal and centripetal flows. The inward flow involves only the "mouth" openings on the internal wing of the oral arm and relative hemi-canals, while the outward flow involves only the two outermost wings' hemi-canals and relative "anal" openings on the external oral arm. The openings differentiation recalls the functional characteristics of a through-gut apparatus. We cannot define the gastrovascular system in Rhizostoma pulmo as a traditional through-gut, rather an example of adaptive convergence, that partially invalidates the paradigm of a single oral opening with both the uptake and excrete function.

Jellyfish as an Alternative Source of Bioactive Antiproliferative Compounds.

Jellyfish are commonly considered a nuisance for their negative effects on human activities (e.g., fisheries, power plants and tourism) and human health. However, jellyfish provide several benefits to humans and are commonly eaten in eastern countries. Additionally, recent studies have suggested that jellyfish may become a source of high-value molecules. In this study, we tested the effects of the methanolic extracts and enriched fractions, obtained by solid-phase extraction fractionation, from the scyphomedusae Pelagia noctiluca, Rhizostoma pulmo, Cotylorhiza tuberculata and the cubomedusa Caryddea marsupialis on different human cancer cell lines in order to evaluate a potential antiproliferative activity. Our results indicated that fraction C from Caryddea marsupialis-(CM) and C. tuberculata oral arms (CTOA) were the most active to reduce cell viability in a dose-dependent manner. LC/MS based dereplication analyses highlighted that both bioactive fractions contained mainly fatty acids and derivatives, with CM additionally containing small peptides (0.7-0.8 kDa), which might contribute to its higher biological activity. The mechanism of action behind the most active fraction was investigated using PCR arrays. Results showed that the fraction C of CM can reduce the expression of genes involved in apoptosis inhibition in melanoma-treated cells, which makes jellyfish a potential new source of antiproliferative drugs to be exploited in the future.

Jellyfish mucin (qniumucin) extracted with a modified protocol indicated its existence as a constituent of the extracellular matrix.

Jellyfish (JF) mucin (precisely, a mucin-type glycoprotein named qniumucin: Q-mucin) first discovered in JF is mainly composed of highly O-glycosylated domains, and its unique structure suggests its wide applications as a smart material. In this study, the standard protocol used to date was thoroughly reinvestigated because the processing of raw JF was rather difficult and continuous production from frozen sources was also indispensable. Finally, we concluded that Q-mucin is involved not in mucus but in the mesoglea, i.e., the extracellular matrix (ECM), as a part of a very large polymer complex. We added a treatment procedure with a chelate reagent (e.g. EDTA) to inactivate endogenous proteases that induce the spontaneous decomposition of the collagens in ECM. The amino acid composition (AAC) of each precipitate formed upon EtOH addition indicated that Q-mucin dissociates from the biopolymer complex as a constituent highly soluble in deionized water. Since the remaining portion of ECM still seemed to contain a large amount of the precursor of Q-mucin even after the extraction with water is completed, the yield of Q-mucin is expected to increase markedly if an innovative method to decompose EtOH precipitates is developed. The existence of Q-mucin in ECM seems to be described in parallel with that of proteoglycans (PG) in mammalian cartilage because they resemble each other.

Bio-assisted synthesis of bimetallic nanoparticles featuring antibacterial and photothermal properties for the removal of biofilms.

Biofilms are responsible for about considerable amounts of cases of bacterial infections in humans. They are considered a major threat to transplant and chronic wounds patients due to their highly resistant nature against antibacterial materials and due to the limited types of techniques that can be applied to remove them. Here we demonstrate a successful in-situ bio-assisted synthesis of dual functionality nanoparticles composed of Silver and Gold. This is done using a jellyfish-based scaffold, an antibacterial material as the templating host in the synthesis. We further explore the scaffold's antibacterial and photothermal properties against various gram-negative and positive model bacteria with and without photo-induced heating at the Near-IR regime. We show that when the scaffold is loaded with these bimetallic nanoparticles, it exhibits dual functionality: Its photothermal capabilities help to disrupt and remove bacterial colonies and mature biofilms, and its antibacterial properties prevent the regrowth of new biofilms.

Jellyfish venom proteins and their pharmacological potentials: A review.

Several research in the organisms of marine invertebrates to assess the medicinal ability of its bio-active molecules have yielded very positive results in recent times. Jellyfish secreted venoms are rich sources of toxins intended to catch prey or deter predators among invertebrate species, but they may also have harmful effects on humans. The nematocyst, a complex intracellular system that injects a venomous mixture into prey or predators that come into contact with the tentacles or other parts of the body of cnidarians, determines the venomous existence of cnidarians. Nematocyst venoms are mixtures of peptides, proteins and other components that in laboratory animals can induce cytotoxicity, blockade of ion channels, membrane pore formation, in vivo cardiovascular failure and lethal effects. There are also valuable pharmacological and biological aspects of jellyfish venoms. In the present review, overviews of the variety of possible toxin families in cnidarian venoms are addressed in this analysis and these potential toxins are surveyed with those from other cnidarians that offer insight into their potential functions such as anti-oxidant, anti-cancer activity and much more. This research review will provide awareness of the growing repertoire of jellyfish venom proteins and will help to further isolate and classify particular proteins to understand its structure and functional relationship.

In Vitro Investigation of Jellyfish Collagen as a Tool in Cell Culture and (Bone) Tissue Engineering.

BACKGROUND/AIM: Jellyfish collagen serves as a competitive alternative to mammalian-sourced collagen in many practical aspects. For instance, jellyfish collagen lacks religious constraints when compared to bovine or porcine sources and promises batch-to-batch consistency. Another advantage is its structural similarity with many mammalian collagen types, providing a biocompatible matrix for different cell types as "collagen type 0". This paper intends to investigate jellyfish collagen (Jellagen®) in two applications. This investigation aims to establish an initial understanding of jellyfish collagen in biotechnology. More specifically, in cell culture and the field of tissue engineering. MATERIALS AND METHODS: The jellyfish collagen was comparatively tested as a coating material for multi-well plates as one of the most extensively used tools in cell culture and in the form of three-dimensional (3D) scaffolds intended for bone tissue engineering (BTE) applications. Both, the coated well plates and the scaffolds were seeded with fibroblasts and pre-osteoblasts, separately. In vitro cytocompatibility assays in accordance with EN ISO 10993-5/-12 regulations and LIVE-DEAD-stainings were carried out to study the cell viability, cytotoxicity and proliferation of these two cell lines. RESULTS: The results showed that collagen extracted from R. pulmo jellyfish can be an alternative to mammalian-derived collagen. Fibroblasts showed comparable cell viability to the medium control and an increased cell proliferation on the well plates indicating that these coated well plates can be used in cell culture, particularly in biocompatibility studies of biomaterials (as fibroblasts are used in this respective field extensively). The viability of pre-osteoblasts significantly exceeded the medium control in case of the jellyfish 3D scaffolds. CONCLUSION: These cells exhibited favorable healthy behavior on this marine collagen, suggesting that Jellagen® collagen can be used in studies of (bone) tissue regeneration and especially as scaffolds in BTE. In conclusion, jellyfish collagen provides biocompatibility and adhesive properties for both cell culture and BTE applications.

Extraction, anti-tyrosinase, and antioxidant activities of the collagen hydrolysate derived from Rhopilema hispidum.

The study was conducted to determine anti-tyrosinase and antioxidant activities of the extracted collagen hydrolysate (CH) derived from Malaysian jellyfish, Rhopilema hispidum. Collagen was extracted using 1:1 (w:v) 0.1 M NaOH solution at temperature 25 °C for 48 hr followed by treatment of 1:2 (w:v) distilled water for another 24 hr and freeze-dried. The extracted collagen was hydrolyzed using papain at optimum temperature, pH and enzyme/substrate ratio [E/S] of 60 °C, 7.0 and 1:50, respectively. CH was found to exhibit tyrosinase inhibitory activity, DPPH radical scavenging and metal ion-chelating assays up to 64, 28, and 83%, respectively, after 8 hr of hydrolysis process. The molecular weight of CH was found <10 kDa consisting of mainly Gly (19.219%), Glu (10.428%), and Arg (8.848%). The UV-visible spectrum analysis showed a major and minor peak at 218 and 276 nm, accordingly. The FTIR spectroscopy confirmed the amide groups in CH. The SEM images demonstrated spongy and porous structure of CH. In the cytotoxicity study, CH has no cytotoxicity against mouse embryonic 3T3 fibroblast cell line with IC50 value >500 µg/ml. Results revealed that the CH generated from this study has a potential to be developed as active ingredient in cosmeceutical application.

Danio rerio as an alternative vertebrate model for jellyfish venom study: The toxinological aspects of Nemopilema nomurai venom.

Nemopilema nomurai venom (NnV) is severely toxic to many organisms. However, the mechanism of its poisoning has not been properly understood yet. The present work demonstrates that zebrafish (Danio rerio) is an alternative vertebrate model for studying NnV jellyfish venom for the first time. In this model, NnV appears to cause severe hemorrhage and inflammation in cardiopulmonary regions of zebrafish. NnV also altered the swimming behavior of zebrafish accompanied by a significant downregulation of acetylcholinesterase (AChE) activity in brain tissues. Histopathological changes observed for various organs of D. rerio caused by NnV corresponded to an increase in lactate dehydrogenase (LDH) activity in tissues. NnV also significantly altered glutathione S-transferase (GST) activity in cardiopulmonary and brain tissues of D. rerio. SDS-PAGE revealed many protein bands of NnV of various sizes after silver staining. Taken together, these results indicate that Danio rerio can be a useful alternative animal model for jellyfish venom toxicology studies. Findings of the present study also suggest that Danio rerio could be used to develop an effective treatment strategy and discover the mechanism of action of jellyfish venom envenomation.

Protective effect of epigallocatechin-3-gallate (EGCG) on toxic metalloproteinases-mediated skin damage induced by Scyphozoan jellyfish envenomation.

Jellyfish stingings are currently raising serious public health concerns around the world. Hence, the search for an effective first aid reagent for the envenomation has been the goal of many investigators in the field. There have been a few previous reports of in vivo as well as in vivo studies suggesting the metalloproteinase activity of scyphozoan jellyfish venom, such as N. nomurai venom (NnV), plays a major role in the pathogenesis. These results have inspired us to develop a metalloproteinase inhibitor as a candidate for the treatment of Scyphozoan jellyfish envenomation. It has been previously demonstrated that the major polyphenol component in green tea, epigallocatechin-3-gallate (EGCG), can inhibit metalloproteinase activity of snake venoms. In fact, plant polyphenols as potential therapeutics have been shown to exert positive effects on neutralizing snake venoms and toxins. In the present study, we found that EGCG significantly inhibits the toxic proteases of NnV in a concentration-dependent manner. Human keratinocyte (HaCaT) and Human dermal fibroblast (HDF) cell culture studies showed that EGCG treatment can protect the cells from NnV-induced cytotoxicity which has been accompanied by the down-regulation of human matrix metalloproteinase (MMP)-2 and -9. Simulated rat NnV envenomation study disclosed that topical treatments with EGCG considerably ameliorated the progression of the dermonecrotic lesions caused by NnV. EGCG also reduced the activitions of tissue MMP-2 and MMP-9, which seem to be crucial players in the dermal toxic responses induced by NnV. Therefore, we propose that EGCG might be an effective therapeutic agent for the treatment of cutaneoous jellyfish symptoms.

Production of Injectable Marine Collagen-Based Hydrogel for the Maintenance of Differentiated Chondrocytes in Tissue Engineering Applications.

Cartilage is an avascular tissue with limited ability of self-repair. The use of autologous chondrocyte transplants represent an effective strategy for cell regeneration; however, preserving the differentiated state, which ensures the ability to regenerate damaged cartilage, represents the main challenge during in vitro culturing. For this purpose, we produced an injectable marine collagen-based hydrogel, by mixing native collagen from the jellyfish Rhizostoma pulmo with hydroxy-phenyl-propionic acid (HPA)-functionalized marine gelatin. This biocompatible hydrogel formulation, due to the ability of enzymatically reticulate using horseradish peroxidase (HPR) and H2O2, gives the possibility of trap cells inside, in the absence of cytotoxic effects, during the cross-linking process. Moreover, it enables the modulation of the hydrogel stiffness merely varying the concentration of H2O2 without changes in the concentration of polymer precursors. The maintenance of differentiated chondrocytes in culture was then evaluated via morphological analysis of cell phenotype, GAG production and cytoskeleton organization. Additionally, gene expression profiling of differentiation/dedifferentiation markers provided evidence for the promotion of the chondrogenic gene expression program. This, combined with the biochemical properties of marine collagen, represents a promising strategy for maintaining in vitro the cellular phenotype in the aim of the use of autologous chondrocytes in regenerative medicine practices.