Editorial

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6 pages, 200 KiB

Open AccessEditorial

Chemical Defense in Marine Organisms

by Chiara Lauritano and Adrianna Ianora

Mar. Drugs 2020, 18(10), 518; https://doi.org/10.3390/md18100518 - 18 Oct 2020

Cited by 8 | Viewed by 2483

Abstract

Marine organisms are constantly exposed to variations in physical parameters (e [...] Full article

(This article belongs to the Special Issue Chemical Defense in Marine Organisms)

Research

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26 pages, 2561 KiB

Open AccessArticle

De Novo Transcriptome Assembly and Gene Expression Profiling of the Copepod Calanus helgolandicus Feeding on the PUA-Producing Diatom Skeletonema marinoi

by Sneha Asai, Remo Sanges, Chiara Lauritano, Penelope K. Lindeque, Francesco Esposito, Adrianna Ianora and Ylenia Carotenuto

Mar. Drugs 2020, 18(8), 392; https://doi.org/10.3390/md18080392 - 27 Jul 2020

Cited by 21 | Viewed by 3935

Abstract

Diatoms are the dominant component of the marine phytoplankton. Several diatoms produce secondary metabolites, namely oxylipins, with teratogenic effects on their main predators, crustacean copepods. Our study reports the de novo assembled transcriptome of the calanoid copepod Calanus helgolandicus feeding on the oxylipin-producing [...] Read more.

Diatoms are the dominant component of the marine phytoplankton. Several diatoms produce secondary metabolites, namely oxylipins, with teratogenic effects on their main predators, crustacean copepods. Our study reports the de novo assembled transcriptome of the calanoid copepod Calanus helgolandicus feeding on the oxylipin-producing diatom Skeletonema marinoi. Differential expression analysis was also performed between copepod females exposed to the diatom and the control flagellate Prorocentrum minimum, which does not produce oxylipins. Our results showed that transcripts involved in carbohydrate, amino acid, folate and methionine metabolism, embryogenesis, and response to stimulus were differentially expressed in the two conditions. Expression of 27 selected genes belonging to these functional categories was also analyzed by RT-qPCR in C. helgolandicus females exposed to a mixed solution of the oxylipins heptadienal and octadienal at the concentration of 10 µM, 15 µM, and 20 µM. The results confirmed differential expression analysis, with up-regulation of genes involved in stress response and down-regulation of genes associated with folate and methionine metabolism, embryogenesis, and signaling. Overall, we offer new insights on the mechanism of action of oxylipins on maternally-induced embryo abnormality. Our results may also help identify biomarker genes associated with diatom-related reproductive failure in the natural copepod population at sea. Full article

(This article belongs to the Special Issue Chemical Defense in Marine Organisms)

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21 pages, 1445 KiB

Open AccessArticle

De novo Transcriptome of the Non-saxitoxin Producing Alexandrium tamutum Reveals New Insights on Harmful Dinoflagellates

by Giorgio Maria Vingiani, Dārta Štālberga, Pasquale De Luca, Adrianna Ianora, Daniele De Luca and Chiara Lauritano

Mar. Drugs 2020, 18(8), 386; https://doi.org/10.3390/md18080386 - 24 Jul 2020

Cited by 21 | Viewed by 4096

Abstract

Many dinoflagellates species, especially of the Alexandrium genus, produce a series of toxins with tremendous impacts on human and environmental health, and tourism economies. Alexandrium tamutum was discovered for the first time in the Gulf of Naples, and it is not known to [...] Read more.

Many dinoflagellates species, especially of the Alexandrium genus, produce a series of toxins with tremendous impacts on human and environmental health, and tourism economies. Alexandrium tamutum was discovered for the first time in the Gulf of Naples, and it is not known to produce saxitoxins. However, a clone of A. tamutum from the same Gulf showed copepod reproduction impairment and antiproliferative activity. In this study, the full transcriptome of the dinoflagellate A. tamutum is presented in both control and phosphate starvation conditions. RNA-seq approach was used for in silico identification of transcripts that can be involved in the synthesis of toxic compounds. Phosphate starvation was selected because it is known to induce toxin production for other Alexandrium spp. Results showed the presence of three transcripts related to saxitoxin synthesis (sxtA, sxtG and sxtU), and others potentially related to the synthesis of additional toxic compounds (e.g., 44 transcripts annotated as “polyketide synthase”). These data suggest that even if this A. tamutum clone does not produce saxitoxins, it has the potential to produce toxic metabolites, in line with the previously observed activity. These data give new insights into toxic microalgae, toxin production and their potential applications for the treatment of human pathologies. Full article

(This article belongs to the Special Issue Chemical Defense in Marine Organisms)

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16 pages, 4423 KiB

Open AccessArticle

A Truncated Galectin-3 Isolated from Skin Mucus of Atlantic Salmon Salmo salar Binds to and Modulates the Proteome of the Gram-Negative Bacteria Moritella viscosa

by Deepti Manjari Patel, Yoichiro Kitani, Kjetil Korsnes, Martin Haugmo Iversen and Monica Fengsrud Brinchmann

Mar. Drugs 2020, 18(2), 102; https://doi.org/10.3390/md18020102 - 04 Feb 2020

Cited by 9 | Viewed by 3833

Abstract

The mucus of fish skin plays a vital role in innate immune defense. Some mucus proteins have the potential to incapacitate pathogens and/or inhibit their passage through the skin. In this study the aim was to isolate and characterize galectin(s), β-galactosides binding proteins, [...] Read more.

The mucus of fish skin plays a vital role in innate immune defense. Some mucus proteins have the potential to incapacitate pathogens and/or inhibit their passage through the skin. In this study the aim was to isolate and characterize galectin(s), β-galactosides binding proteins, present in skin mucus. A novel short form of galectin-3 was isolated from Atlantic salmon skin mucus by α-lactose agarose based affinity chromatography followed by Sephadex G-15 gel filtration. Mass spectrometric analysis showed that the isolated protein was the C-terminal half of galectin-3 (galectin-3C). Galectin-3C showed calcium independent and lactose inhabitable hemagglutination, and agglutinated the Gram-negative pathogenic bacteria Moritella viscosa. Galectin-3 mRNA was highly expressed in skin and gill, followed by muscle, hindgut, spleen, stomach, foregut, head kidney, and liver. Moritella viscosa incubated with galectin-3C had a modified proteome. Proteins with changed abundance included multidrug transporter and three ribosomal proteins L7/12, S2, and S13. Overall, this study shows the isolation and characterization of a novel galectin-3 short form involved in pathogen recognition and modulation, and hence in immune defense of Atlantic salmon. Full article

(This article belongs to the Special Issue Chemical Defense in Marine Organisms)

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17 pages, 1841 KiB

Open AccessArticle

Genome-Wide Identification and Characterization of SODs in Zhikong Scallop Reveals Gene Expansion and Regulation Divergence after Toxic Dinoflagellate Exposure

by Shanshan Lian, Liang Zhao, Xiaogang Xun, Jiarun Lou, Moli Li, Xu Li, Shi Wang, Lingling Zhang, Xiaoli Hu and Zhenmin Bao

Mar. Drugs 2019, 17(12), 700; https://doi.org/10.3390/md17120700 - 12 Dec 2019

Cited by 24 | Viewed by 3259

Abstract

As filter-feeding animals mainly ingesting microalgae, bivalves could accumulate paralytic shellfish toxins (PSTs) produced by harmful algae through diet. To protect themselves from the toxic effects of PSTs, especially the concomitant oxidative damage, the production of superoxide dismutase (SOD), which is the only [...] Read more.

As filter-feeding animals mainly ingesting microalgae, bivalves could accumulate paralytic shellfish toxins (PSTs) produced by harmful algae through diet. To protect themselves from the toxic effects of PSTs, especially the concomitant oxidative damage, the production of superoxide dismutase (SOD), which is the only eukaryotic metalloenzyme capable of detoxifying superoxide, may assist with toxin tolerance in bivalves. To better understand this process, in the present study, we performed the first systematic analysis of SOD genes in bivalve Chlamys farreri, an important aquaculture species in China. A total of six Cu/Zn-SODs (SOD1-6) and two Mn-SODs (SOD7, SOD8) were identified in C. farreri, with gene expansion being revealed in Cu/Zn-SODs. In scallops exposed to two different PSTs-producing dinoflagellates, Alexandrium minutum and A. catenella, expression regulation of SOD genes was analyzed in the top ranked toxin-rich organs, the hepatopancreas and the kidney. In hepatopancreas, which mainly accumulates the incoming PSTs, all of the six Cu/Zn-SODs showed significant alterations after A. minutum exposure, with SOD1, 2, 3, 5, and 6 being up-regulated, and SOD4 being down-regulated, while no significant change was detected in Mn-SODs. After A. catenella exposure, up-regulation was observed in SOD2, 4, 6, and 8, and SOD7 was down-regulated. In the kidney, where PSTs transformation occurs, SOD4, 5, 6, and 8 were up-regulated, and SOD7 was down-regulated in response to A. minutum feeding. After A. catenella exposure, all the Cu/Zn-SODs except SOD1 were up-regulated, and SOD7 was down-regulated in kidney. Overall, in scallops after ingesting different toxic algae, SOD up-regulation mainly occurred in the expanded Cu/Zn-SOD group, and SOD6 was the only member being up-regulated in both toxic organs, which also showed the highest fold change among all the SODs, implying the importance of SOD6 in protecting scallops from the stress of PSTs. Our results suggest the diverse function of scallop SODs in response to the PST-producing algae challenge, and the expansion of Cu/Zn-SODs might be implicated in the adaptive evolution of scallops or bivalves with respect to antioxidant defense against the ingested toxic algae. Full article

(This article belongs to the Special Issue Chemical Defense in Marine Organisms)

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16 pages, 7755 KiB

Open AccessArticle

ABC Transporters in Prorocentrum lima and Their Expression Under Different Environmental Conditions Including Okadaic Acid Production

by Song Gu, Shao-Wen Xiao, Jian-Wei Zheng, Hong-Ye Li, Jie-Sheng Liu and Wei-Dong Yang

Mar. Drugs 2019, 17(5), 259; https://doi.org/10.3390/md17050259 - 30 Apr 2019

Cited by 11 | Viewed by 4170

Abstract

Prorocentrum lima is a typical benthic toxic dinoflagellate, which can produce phycotoxins such as okadaic acid (OA). In this study, we identified three ABC transporter genes (ABCB1, ABCC1 and ABCG2) and characterized their expression patterns, as well as OA production [...] Read more.

Prorocentrum lima is a typical benthic toxic dinoflagellate, which can produce phycotoxins such as okadaic acid (OA). In this study, we identified three ABC transporter genes (ABCB1, ABCC1 and ABCG2) and characterized their expression patterns, as well as OA production under different environmental conditions in P. lima. We found that the three ABC transporters all showed high identity with related ABC proteins from other species, and contained classical features of ABC transport proteins. Among them, ABCG2 was a half size transporter. The three ABC transporter genes displayed various expression profiles under different conditions. The high concentration of Cu²⁺ could up-regulate ABCB1, ABCC1 and ABCG2 transcripts in P. lima, suggesting the potential defensive role of ABC transporters against metal ions in surrounding waters. Cu²⁺, in some concentration, could induce OA production; meanwhile, tributyltin inhibited OA accumulation. The grazer Artemia salina could induce OA production, and P. lima displayed some toxicity to the grazer, indicating the possibility of OA as an anti-grazing chemical. Collectively, our results revealed intriguing data about OA production and the expression patterns of three ABC transporter genes. However, we could not find any significant correlation between OA production and expression pattern of the three ABC transporters in P. lima. Our results might provide new molecular insights on the defensive responses of P. lima to the surrounding environment. Full article

(This article belongs to the Special Issue Chemical Defense in Marine Organisms)

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11 pages, 2041 KiB

Open AccessArticle

Molecular and Morphological Toxicity of Diatom-Derived Hydroxyacid Mixtures to Sea Urchin Paracentrotus lividus Embryos

by Luisa Albarano, Nadia Ruocco, Adrianna Ianora, Giovanni Libralato, Loredana Manfra and Maria Costantini

Mar. Drugs 2019, 17(3), 144; https://doi.org/10.3390/md17030144 - 01 Mar 2019

Cited by 8 | Viewed by 3067

Abstract

Oxylipins such as polyunsaturated aldehydes (PUAs) and hydroxyacids (HEPEs) are signaling molecules derived from the oxidation of polyunsaturated fatty acids. They are common in diatoms that constitute a major group of microalgae in freshwater and oceanic ecosystems. Although HEPEs represent the most common [...] Read more.

Oxylipins such as polyunsaturated aldehydes (PUAs) and hydroxyacids (HEPEs) are signaling molecules derived from the oxidation of polyunsaturated fatty acids. They are common in diatoms that constitute a major group of microalgae in freshwater and oceanic ecosystems. Although HEPEs represent the most common oxylipins produced by diatoms, little information is available on their effects on marine invertebrates, and most of the information has been obtained by testing individual HEPEs. Our previous studies reported that four hydroxyacids, i.e., 5-, 9-, 11-, and 15-HEPE, were able to induce malformations and a marked developmental delay in sea urchin Paracentrotus lividus embryos, which had not been reported for other oxylipins. Here, we tested a mixture of 5-, 9-, 11-, and 15-HEPE at different concentrations for the first time. The results showed that mixtures of HEPEs have synergistic effects that are much more severe compared to those of individual HEPEs: The HEPE mixtures induced malformations in sea urchin embryos at lower concentrations. Increasing HEPE mixture concentrations induced a marked increase in the number of delayed embryos, until all embryos were delayed at the highest concentration tested. At the molecular level, the HEPE mixtures induced variations in the expression of 50 genes involved in different functional processes, mainly down-regulating these genes at the earliest stages of embryonic development. These findings are ecologically significant, considering that during diatom blooms, sea urchins could accumulate HEPEs in concentrations comparable to those tested in the present study. Full article

(This article belongs to the Special Issue Chemical Defense in Marine Organisms)

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12 pages, 1563 KiB

Open AccessArticle

Cytotoxic Nitrogenous Terpenoids from Two South China Sea Nudibranchs Phyllidiella pustulosa, Phyllidia coelestis, and Their Sponge-Prey Acanthella cavernosa

by Qihao Wu, Wen-Ting Chen, Song-Wei Li, Jian-Yu Ye, Xia-Juan Huan, Margherita Gavagnin, Li-Gong Yao, Hong Wang, Ze-Hong Miao, Xu-Wen Li and Yue-Wei Guo

Mar. Drugs 2019, 17(1), 56; https://doi.org/10.3390/md17010056 - 16 Jan 2019

Cited by 25 | Viewed by 4335

Abstract

A detailed chemical investigation of two South China Sea nudibranchs Phyllidiella pustulosa and Phyllidia coelestis, as well as their possible sponge-prey Acanthella cavernosa, led to the isolation of one new nitrogenous cadinane-type sesquiterpenoid xidaoisocyanate A (1), one new naturally [...] Read more.

A detailed chemical investigation of two South China Sea nudibranchs Phyllidiella pustulosa and Phyllidia coelestis, as well as their possible sponge-prey Acanthella cavernosa, led to the isolation of one new nitrogenous cadinane-type sesquiterpenoid xidaoisocyanate A (1), one new naturally occurring nitrogen-containing kalihinane-type diterpenoid bisformamidokalihinol A (16), along with 17 known nitrogenous terpenoids (2–15, 17–19). The structures of all the isolates were elucidated by detailed spectroscopic analysis and by the comparison of their spectroscopic data with those reported in the literature. In addition, the absolute stereochemistry of the previously reported axiriabiline A (5) was determined by X-ray diffraction (XRD) analysis. In a bioassay, the bisabolane-type sesquiterpenoids 8, 10, and 11 exhibited cytotoxicity against several human cancer cell lines. Full article

(This article belongs to the Special Issue Chemical Defense in Marine Organisms)

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28 pages, 850 KiB

Open AccessFeature PaperReview

A Review of Toxins from Cnidaria

by Isabella D’Ambra and Chiara Lauritano

Mar. Drugs 2020, 18(10), 507; https://doi.org/10.3390/md18100507 - 06 Oct 2020

Cited by 44 | Viewed by 7941

Abstract

Cnidarians have been known since ancient times for the painful stings they induce to humans. The effects of the stings range from skin irritation to cardiotoxicity and can result in death of human beings. The noxious effects of cnidarian venoms have stimulated the [...] Read more.

Cnidarians have been known since ancient times for the painful stings they induce to humans. The effects of the stings range from skin irritation to cardiotoxicity and can result in death of human beings. The noxious effects of cnidarian venoms have stimulated the definition of their composition and their activity. Despite this interest, only a limited number of compounds extracted from cnidarian venoms have been identified and defined in detail. Venoms extracted from Anthozoa are likely the most studied, while venoms from Cubozoa attract research interests due to their lethal effects on humans. The investigation of cnidarian venoms has benefited in very recent times by the application of omics approaches. In this review, we propose an updated synopsis of the toxins identified in the venoms of the main classes of Cnidaria (Hydrozoa, Scyphozoa, Cubozoa, Staurozoa and Anthozoa). We have attempted to consider most of the available information, including a summary of the most recent results from omics and biotechnological studies, with the aim to define the state of the art in the field and provide a background for future research. Full article

(This article belongs to the Special Issue Chemical Defense in Marine Organisms)

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