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Foods (Basel, Switzerland) May 2024Vitamins are essential organic compounds that vary widely in chemical structure and are vital in small quantities for numerous biochemical and biological functions. They... (Review)
Review
Vitamins are essential organic compounds that vary widely in chemical structure and are vital in small quantities for numerous biochemical and biological functions. They are critical for metabolism, growth, development and maintaining overall health. Vitamins are categorised into two groups: hydrophilic and lipophilic. Vitamin K (VK), a lipophilic vitamin, occurs naturally in two primary forms: phylloquinone (VK1), found in green leafy vegetables and algae, and Menaquinones (VK2), present in certain fermented and animal foods and widely formulated in VK supplements. This review explores the possible factors contributing to VK deficiency, including dietary influences, and discusses the pharmacological and therapeutic potential of supplementary VK2, examining recent global clinical studies on its role in treating diseases such as osteoporosis, osteoarthritis, rheumatoid arthritis, cardiovascular disease, chronic kidney disease, diabetes, neurodegenerative disorders and cancers. The analysis includes a review of published articles from multiple databases, including Scopus, PubMed, Google Scholar, ISI Web of Science and CNKI, focusing on human studies. The findings indicate that VK2 is a versatile vitamin essential for human health and that a broadly positive correlation exists between VK2 supplementation and improved health outcomes. However, clinical data are somewhat inconsistent, highlighting the need for further detailed research into VK2's metabolic processes, biomarker validation, dose-response relationships, bioavailability and safety. Establishing a Recommended Daily Intake for VK2 could significantly enhance global health.
PubMed: 38890875
DOI: 10.3390/foods13111646 -
Biology Letters Jun 2024Red coralline algae create abundant, spatially vast, reef ecosystems throughout our coastal oceans with significant ecosystem service provision, but our understanding of...
Red coralline algae create abundant, spatially vast, reef ecosystems throughout our coastal oceans with significant ecosystem service provision, but our understanding of their basic physiology is lacking. In particular, the balance and linkages between carbon-producing and carbon-sequestering processes remain poorly constrained, with significant implications for understanding their role in carbon sequestration and storage. Using dual radioisotope tracing, we provide evidence for coupling between photosynthesis (which requires CO) and calcification (which releases CO) in the red coralline alga (previously )-a marine ecosystem engineer widely distributed across Atlantic mid-high latitudes. Of the sequestered HCO , 38 ± 22% was deposited as carbonate skeleton while 39 ± 14% was incorporated into organic matter via photosynthesis. Only 38 ± 2% of the sequestered HCO was transformed into CO, and almost 40% of that was internally recycled as photosynthetic substrate, reducing the net release of carbon to 23 ± 3% of the total uptake. The calcification rate was strongly dependent on photosynthetic substrate production, supporting the presence of photosynthetically enhanced calcification. The efficient carbon-recycling physiology reported here suggests that calcifying algae may not contribute as much to marine CO release as is currently assumed, supporting a reassessment of their role in blue carbon accounting.
Topics: Photosynthesis; Rhodophyta; Calcification, Physiologic; Carbon; Carbon Dioxide; Carbon Cycle; Carbon Sequestration
PubMed: 38889774
DOI: 10.1098/rsbl.2023.0598 -
Plant Direct Jun 2024Eukaryotic cells are highly compartmentalized, requiring elaborate transport mechanisms to facilitate the movement of proteins between membrane-bound compartments. Most...
Eukaryotic cells are highly compartmentalized, requiring elaborate transport mechanisms to facilitate the movement of proteins between membrane-bound compartments. Most proteins synthesized in the endoplasmic reticulum (ER) are transported to the Golgi apparatus through COPII-mediated vesicular trafficking. Sar1, a small GTPase that facilitates the formation of COPII vesicles, plays a critical role in the early steps of this protein secretory pathway. Sar1 was characterized in yeast, animals and plants, but no Sar1 homolog has been identified and functionally analyzed in algae. Here we identified a putative Sar1 homolog (CrSar1) in the model green alga through amino acid sequence similarity. We employed site-directed mutagenesis to generate a dominant-negative mutant of CrSar1 (CrSar1DN). Using protein secretion assays, we demonstrate the inhibitory effect of CrSar1DN on protein secretion. However, different from previously studied organisms, ectopic expression of CrSar1DN did not result in collapse of the ER-Golgi interface in . Nonetheless, our data suggest a largely conserved role of CrSar1 in the ER-to-Golgi protein secretory pathway in green algae.
PubMed: 38887666
DOI: 10.1002/pld3.614 -
Veterinary Pathology Jun 2024is a genus of nonphotosynthetic, green algae in the family , closely related to . It is a known pathogen of invertebrates, and its occurrence in vertebrates has not...
is a genus of nonphotosynthetic, green algae in the family , closely related to . It is a known pathogen of invertebrates, and its occurrence in vertebrates has not been documented. A captive, 10-month-old, male, albino California kingsnake () was submitted for necropsy. Gross examination revealed hemorrhagic laryngitis and a red mottled liver. Histologically, intravascular, intramonocytic/macrophagic and extracellular, eukaryotic organisms were observed in all tissues. These organisms stained positive with Grocott-Gomori methenamine silver and periodic acid-Schiff and were variably acid-fast and gram-positive. Ultrastructural analysis revealed approximately 4 µm vegetative multiplication forms and cysts with 3 parallel ovoid cells and a helically coiled filamentous cell. A polymerase chain reaction with primers targeting , amplicon sequencing, and Bayesian phylogenetic analysis confirmed it clustered within sp. with 100% posterior probability. The genus was found to nest within the genus , forming a clade with with 80% posterior probability.
PubMed: 38881033
DOI: 10.1177/03009858241259179 -
Analytica Chimica Acta Aug 2024Arsenosugars are the predominant species of arsenic in most seaweed. The analysis of these compounds is hampered by the lack of calibration standards needed in their...
Arsenosugars are the predominant species of arsenic in most seaweed. The analysis of these compounds is hampered by the lack of calibration standards needed in their unambiguous identification and quantification. This affects the availability of reliable information on their potential toxicity, which is scarce and controversial. Knowing the potential of centrifugal partition chromatography (CPC) as a preparative separation technique applied to a number of natural compounds, the aim of this work is to investigate the feasibility of CPC in the case of isolation and purification of arsenosugars from algae extracts. Several biphasic solvents systems have been studied to evaluate the distribution of the As species. Given the physical characteristics of these compounds, the presence of strong acids, the formation of ionic pairs or the presence of salts at high ionic strength have been considered. System 1-BuOH/EtOH/sat.(NH)SO/water at a volume ratio 0.2:1:1:1 originates adequate distribution constants of analytes that allows the required separation. The total arsenic content and the arsenic speciation of the eluted solutions from CPC were analyzed by ICP-MS and IC-ICP-MS, respectively. The developed CPC procedure allows us to obtain of the three arsenosugars with a purity of 98.7 % in PO-Sug, 90.4 % in SO-Sug and 96.1 % in SO-Sug.
Topics: Countercurrent Distribution; Arsenates; Seaweed; Monosaccharides
PubMed: 38879213
DOI: 10.1016/j.aca.2024.342814 -
Environment International Jul 2024Mercury is a highly toxic trace metal that can accumulate in aquatic ecosystems and when resent at high concentrations can pose risks to both aquatic life and humans...
Mercury is a highly toxic trace metal that can accumulate in aquatic ecosystems and when resent at high concentrations can pose risks to both aquatic life and humans consuming contaminated fish. This research explores the use of the metalloregulatory protein MerR, known for its high affinity and selectivity toward mercury, in a novel application. Through a cell surface engineering approach, MerR was displayed on cells of green alga Chlamydomonas reinhardtii. A hydroxyproline-rich GP1 protein was used as an anchor to construct the engineered strains GP1-MerR that expresses the fluorescent protein mVenus. The surface engineered GP1-MerR strain led up to five folds higher Hg accumulation compared to the WT strain at concentration range from 10 to 10 M Hg. The binding of Hg via MerR was specific and did not get significantly affected by major freshwater water quality variables such as Ca and dissolved organic matter. The presence of other trace metals (Zn, Cu, Ni, Pb, Cd) in a same concentration range even resulted in 30-40 % increase in the accumulated Hg. Further, the engineered cells also demonstrated the ability to accumulate Hg from the water extracts of the Hg-contaminated sediment samples. These results demonstrate a novel approach utilizing the cell surface display system in C. reinhardtii for its potential application in bioremediation.
Topics: Chlamydomonas reinhardtii; Mercury; Water Pollutants, Chemical; Bacterial Proteins; Biodegradation, Environmental; DNA-Binding Proteins
PubMed: 38878502
DOI: 10.1016/j.envint.2024.108813 -
Marine Pollution Bulletin Jun 2024Cyanobacteria harmful algal blooms (CHABs) are a growing water quality problem in the upper San Francisco Estuary (California), also known as the Sacramento-San Joaquin...
Cyanobacteria harmful algal blooms (CHABs) are a growing water quality problem in the upper San Francisco Estuary (California), also known as the Sacramento-San Joaquin Delta. We conducted cyanobacteria and cyanotoxin monitoring from 2020 to 2023, which spanned California's driest consecutive 3-year period and one of the wettest years on record (2023). To assess the impact of CHABs over this range of hydrologic conditions, we monitored invasive Asian Clams (Corbicula fluminea) for microcystin contamination and used molecular tools (qPCR and sequencing) to characterize cyanobacteria in the water column. We also used solid phase adsorption toxin tracking (SPATT) samplers to track microcystins (MCs) and other cyanotoxins in 2023. During the drought years, record breaking MCs, in excess of 1000 μg/L, were documented in water grab samples and Asian clams also accumulated higher MCs relative to the wet year. However, MCs were present in Asian clams during the entire study period. SPATT's confirmed MC presence during wet 2023 and sequencing results corroborated the integrative sampler findings. Yet, no MC was detected in water grab samples at our primary sampling sites during the drought year of 2022 or the wet year of 2023. This highlights the importance of using multiple sampling modalities to provide a more accurate assessment of MC contamination, especially in large estuaries where traditional discrete monitoring can easily miss episodic and transient CHAB events.
PubMed: 38878417
DOI: 10.1016/j.marpolbul.2024.116585 -
Ecotoxicology and Environmental Safety Jul 2024Early cyanobacterial blooms studies observed that exposure to blue-green algae led to fish gills impairment. The objective of this work was to evaluate the toxic...
Early cyanobacterial blooms studies observed that exposure to blue-green algae led to fish gills impairment. The objective of this work was to evaluate the toxic mechanisms of exudates of Microcystis aeruginosa (MaE) on fish gills. In this study, the toxic mechanism of MaE (2×10 cells/mL) and one of its main components phytosphingosine (PHS) with two concentrations 2.9 ng/mL and 145 ng/mL were conducted by integrating histopathology, biochemical biomarkers, and transcriptomics techniques in Sinocyclocheilus grahami (S. grahami) for 96 h exposure. Damaged gill tissue with epithelial hyperplasia and hypertrophy, remarkable Na/K-ATPase (NKA) enzyme activity, disrupted the redox homeostats including lipid peroxidation and inflammatory responses were observed in the fish of MaE exposure group. Compare to MaE exposure, two concentrations of PHS exposure appeared to be a trend of lower degree of tissue damage, NKA activity and oxidative stress, but induced obviously lipid metabolism disorder with higher triglycerides, total cholesterol and total bile acid, which might be responsible for inflammation responses in fish gill. By transcriptome analysis, MaE exposure were primarily enriched in pathways related to gill function and immune response. PHS exposure, with higher number of differentially expressed genes (DEGs), were enriched in Toll-like receptor (TLR), Mitogen-Activated Protein Kinase (MAPK) and NOD-like receptor protein 3 (NLRP3) pathways. We concluded that MaE and PHS were induced the inflammatory responses, with oxidative stress-induced inflammation for MaE exposure but lipid metabolism disorder-induced inflammation for PHS exposure. The present study provided two toxin-induced gill inflammation response pathways under cyanobacterial blooms, which could be a scientific basis for the ecological and health risk assessment in the aquatic environment.
Topics: Microcystis; Animals; Gills; Oxidative Stress; Inflammation; Lipid Metabolism
PubMed: 38878336
DOI: 10.1016/j.ecoenv.2024.116587 -
Marine Environmental Research Jun 2024Invasive species that outcompete endemic ones and toxic harmful algae that cause algal blooms threaten marine resources like fisheries, aquaculture, and even tourism....
Invasive species that outcompete endemic ones and toxic harmful algae that cause algal blooms threaten marine resources like fisheries, aquaculture, and even tourism. Environmental DNA (eDNA) metabarcoding can help as a method for early alert. In this study, we have analyzed communities inhabiting six lagoons within the Gulf of Lion (northwest Mediterranean Sea) with spatial protection as RAMSAR and Natura 2000 sites. Employing the COI gene as the only metabarcode, we found 15 genera that have caused recognized algal bloom outbreaks in the studied lagoons since 2000. In addition, seven alien invasive species that can pose risks to the rich marine resources of the zone and lagoons were also found. The results found from eDNA are consistent with events of toxic algae blooms before and after the sampling moment and with reported occurrences of the invasive species in nearby Mediterranean areas. Multivariate multiple analysis showed the importance of anthropic pressure in the abundance of these nuisance species. Mitigation actions and routine eDNA metabarcoding in zones of special interest like these fragile French Mediterranean lagoons are recommended for early alert of nuisance species in order to plan timely management actions.
PubMed: 38875900
DOI: 10.1016/j.marenvres.2024.106601 -
Genome Biology and Evolution Jun 2024In flowering plants, euchromatic transposons are transcriptionally silenced by RNA-directed DNA Methylation, a small RNA-guided de novo methylation pathway. RNA-directed...
In flowering plants, euchromatic transposons are transcriptionally silenced by RNA-directed DNA Methylation, a small RNA-guided de novo methylation pathway. RNA-directed DNA Methylation requires the activity of the RNA Polymerases IV and V, which produce small RNA precursors and noncoding targets of small RNAs, respectively. These polymerases are distinguished from Polymerase II by multiple plant-specific paralogous subunits. Most RNA-directed DNA Methylation components are present in all land plants, and some have been found in the charophytic green algae, a paraphyletic group that is sister to land plants. However, the evolutionary origin of key RNA-directed DNA Methylation components, including the two largest subunits of Polymerase IV and Polymerase V, remains unclear. Here, we show that multiple lineages of charophytic green algae encode a single-copy precursor of the largest subunits of Polymerase IV and Polymerase V, resolving the two presumed duplications in this gene family. We further demonstrate the presence of a Polymerase V-like C-terminal domain, suggesting that the earliest form of RNA-directed DNA Methylation utilized a single Polymerase V-like polymerase. Finally, we reveal that charophytic green algae encode a single CLSY/DRD1-type chromatin remodeling protein, further supporting the presence of a single specialized polymerase in charophytic green algae.
Topics: DNA-Directed RNA Polymerases; Evolution, Molecular; DNA Methylation; Phylogeny; Charophyceae; Plant Proteins; Chlorophyta; Protein Subunits
PubMed: 38874416
DOI: 10.1093/gbe/evae119