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Dinoflagellates of the genus Alexandrium cause Harmful Algal Blooms (HABs) in coastal waters worldwide, damaging marine environments, aquaculture, and human health. They synthesize potent neurotoxic alkaloids known as PSTs (i.e., Paralytic Shellfish Toxins), the etiological agents of PSP (i.e., Paralytic Shellfish Poisoning). In recent decades, the eutrophication of coastal waters with inorganic nitrogen (e.g., nitrate, nitrite, and ammonia) has increased the frequency and scale of HABs. PSTs concentrations within Alexandrium cells can increase by up to 76% after a nitrogen enrichment event; however, the mechanisms that underlie their biosynthesis in dinoflagellates remains unclear. This study combines mass spectrometry, bioinformatics, and toxicology and investigates the expression profiles of PSTs in Alexandrium catenella grown in 0.4, 0.9 and 1.3 mM NaNO3. Pathway analysis of protein expression revealed that tRNA amino acylation, glycolysis, TCA cycle and pigment biosynthesis were upregulated in 0.4 mM and downregulated in 1.3 mM NaNO3 compared to those grown in 0.9 mM NaNO3. Conversely, ATP synthesis, photosynthesis and arginine biosynthesis were downregulated in 0.4 mM and upregulated in 1.3 mM NaNO3. Additionally, the expression of proteins involved in PST biosynthesis (sxtA, sxtG, sxtV, sxtW and sxtZ) and overall PST production like STX, NEO, C1, C2, GTX1-6 and dcGTX2 was higher at lower nitrate concentrations. Therefore, increased nitrogen concentrations increase protein synthesis, photosynthesis, and energy metabolism and decrease enzyme expression in PST biosynthesis and production. This research provides new clues about how the changes in the nitrate concentration can modulate different metabolic pathways and the expression of PST biosynthesis in toxigenic dinoflagellates.

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OBJECTIVE: This study is aimed at investigating the changes in serum CypC levels and their relationship with cardiovascular events at 12 months of follow-up in coronary artery disease (CAD) patients. METHODS: The study included a total of 125 subjects (40 patients with acute CAD, 40 patients with chronic CAD, and 45 control volunteers) and we analyzed plasma CypC levels from baseline to 6 and 12 months for a better understanding of its behavior in atherosclerosis. RESULTS: Serum CypC levels were shown to be gradually increased in CAD patients (30.63 pg/mL ± 3.77 at baseline, 38.70 pg/mL ± 6.41 at 6 months [p = 0.25], and 47.27 pg/mL ± 5.65 at 12 months [p = 0.007]). In addition, serum CypC levels during the follow-up were a significant predictor of CAD (c-statistic 0.76 at 6 months and 0.89 at 12 months; p < 0.001). Despite it, there was no significant association between CypC and cardiovascular events, but serum CypC levels tended to be higher in patients suffering cardiovascular events during the follow-up (29.02 pg/mL ± 6.39 vs. 79.96 pg/mL ± 22.18; p = 0.029). In this regard, plasma levels of high-sensitivity C-reactive protein (hsCRP) > 2.3 mg/L plus NT-proBNP > 300 pg/mL together were significant predictors of cardiovascular events during the follow-up in CAD patients with CypC levels >17.5 pg/mL (p = 0.048). CONCLUSIONS: Taken together, our results suggest that serum CypC levels increase during the follow-up in CAD patients and could be a novel biomarker with a possible prognostic value in combination with hsCRP and NT-proBNP.

OBJETIVO: Este estudio tiene como objetivo investigar los cambios en los niveles séricos de CypC y su relación con eventos cardiovasculares a los 12 meses de seguimiento en pacientes con EAC. MÉTODO: El estudio incluyó un total de 125 sujetos (40 pacientes con EAC aguda, 40 pacientes con EAC crónica y 45 voluntarios de control) y se analizaron los niveles ­plasmáticos de CypC desde el inicio hasta los 6 y 12 meses para comprender mejor su comportamiento en la aterosclerosis. RESULTADOS: Se demostró que los niveles séricos de CypC aumentaron gradualmente en pacientes con CAD [(30.63 pg/ml ± 3.77 al inicio del estudio, 38.70 pg/ml ± 6.41 a los 6 meses (p = 0.25) y 47.27 pg/ml ± 5.65 a los 12 meses (p = 0,007)]. Además, los niveles séricos de CypC durante el seguimiento fueron un predictor significativo de EAC (estadístico c 0.76 a los 6 meses y 0.89 a los 12 meses; p < 0.001). A pesar de ello, no hubo asociación significativa entre CypC y eventos cardiovasculares, pero los niveles séricos de CypC tendieron a ser más altos en los pacientes que sufrieron eventos cardiovasculares durante el seguimiento (29.02 pg/mL ± 6.39 vs. 79.96 pg/mL ± 22.18; p = 0.029). En este sentido, los niveles plasmáticos de hsCRP > 2.3 mg/L más NT-proBNP> 300 pg/ml juntos fueron predictores significativos de eventos cardiovasculares durante el seguimiento en pacientes con EAC con niveles de CypC > 17.5 pg/ml (p = 0.048). CONCLUSIONES: Tomados en conjunto, nuestros resultados sugieren que los niveles séricos de CypC aumentan durante el seguimiento en pacientes con EAC y podría ser un nuevo biomarcador con un posible valor pronóstico en combinación con hsCRP y NT-proBNP.

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Seafood represents a significant part of the human staple diet. In the recent years, the identification of emerging lipophilic marine toxins has increased, leading to the potential for consumers to be intoxicated by these toxins. In the present work, we investigate the presence of lipophilic marine toxins (both regulated and emerging) in commercial seafood products from non-European locations, including mussels Mytilus chilensis from Chile, clams Tawerea gayi and Metetrix lyrate from the Southeast Pacific and Vietnam, and food supplements based on mussels formulations of Perna canaliculus from New Zealand. All these products were purchased from European Union markets and they were analyzed by UPLC-MS/MS. Results showed the presence of the emerging pinnatoxin-G in mussels Mytilus chilensis at levels up to 5.2 µg/kg and azaspiracid-2 and pectenotoxin-2 in clams Tawera gayi up to 4.33 µg/kg and 10.88 µg/kg, respectively. This study confirms the presence of pinnatoxins in Chile, one of the major mussel producers worldwide. Chromatograms showed the presence of 13-desmethyl spirolide C in dietary supplements in the range of 33.2-97.9 µg/kg after an extraction with water and methanol from 0.39 g of the green lipped mussels powder. As far as we know, this constitutes the first time that an emerging cyclic imine toxin in dietary supplements is reported. Identifying new matrix, locations, and understanding emerging toxin distribution area are important for preventing the risks of spreading and contamination linked to these compounds.

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Two new zoanthamine alkaloids, namely 3-acetoxynorzoanthamine (1) and 3-acetoxyzoanthamine (2), have been isolated from the zoantharian Zoanthus cf. pulchellus collected off the coast of the Santa Elena Peninsula, Ecuador, together with three known derivatives: zoanthamine, norzoanthamine, and 3-hydroxynorzoanthamine. The chemical structures of 1 and 2 were determined by interpretation of their 1D and 2D NMR data and comparison with literature data. This is the first report of zoanthamine-type alkaloids from Zoanthus cf. pulchellus collected in the Tropical Eastern Pacific. The neuroinflammatory activity of all the isolated compounds was evaluated in microglia BV-2 cells and high inhibitory effects were observed in reactive oxygen species (ROS) and nitric oxide (NO) generation.

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