Experimental ingestion of microplastics in three common Antarctic benthic species.

Microplastics (MP) have spread to every corner of the globe, reaching remote areas like Antarctica. Recent studies detected MP in marine environments, including biota. Benthic organisms suffer negative effects upon MP ingestion, leading to impacts on their populations.

Skeletal magnesium content in Antarctic echinoderms along a latitudinal gradient.

Ocean warming and acidification driven by anthropogenic CO emissions may impact the mineral composition of marine calcifiers. Species with high skeletal Mg content could be more susceptible in polar regions due to the increased solubility of CO at lower temperatures. We aimed to assess the environmental influence on skeletal Mg content of Antarctic echinoderms belonging to Asteroidea, Ophiuroidea, Echinoidea and Holothuroidea classes, along a latitudinal gradient from the South Shetland Islands to Rothera (Adelaide Island).

Peptide Toxins from Antarctica: The Nemertean Predator and Scavenger (McIntosh, 1876).

Peptide toxins from marine invertebrates have found use as drugs and in biotechnological applications. Many marine habitats, however, remain underexplored for natural products, and the Southern Ocean is among them. Here, we report toxins from one of the top predators in Antarctic waters: the nemertean worm (McIntosh, 1876).

Skeletal Mg content in common echinoderm species from Deception and Livingston Islands (South Shetland Islands, Antarctica) in the context of global change.

Echinoderms with high levels of magnesium (Mg) in their skeletons may be especially sensitive to ocean acidification, as the solubility of calcite increases with its Mg content. However, other structural characteristics and environmental/biological factors may affect skeletal solubility. To better understand which factors can influence skeletal mineralogy, we analyzed the Mg content of Antarctic echinoderms from Deception Island, an active volcano with reduced pH and relatively warm water temperatures, and Livingston Island.

Rhodobacteraceae dominate the core microbiome of the sea star (Koehler, 1906) in two opposite geographical sectors of the Antarctic Ocean.

Microbiota plays essential roles in the health, physiology, and in adaptation of marine multi-cellular organisms to their environment. In Antarctica, marine organisms have a wide range of unique physiological functions and adaptive strategies, useful for coping with extremely cold conditions. However, the role of microbiota associated with Antarctic organisms in such adaptive strategies is underexplored.

A Chemo-Ecological Investigation of Topsent, 1905: Identification of Deceptionin and the Effects of Heat Stress and Predation Pressure on Its Terpene Profiles.

Marine sponges usually host a wide array of secondary metabolites that play crucial roles in their biological interactions. The factors that influence the intraspecific variability in the metabolic profile of organisms, their production or ecological function remain generally unknown. Understanding this may help predict changes in biological relationships due to environmental variations as a consequence of climate change.

Quantification and distribution of marine microdebris in the surface waters of Livingston Island (South Shetland Islands, Antarctica).

Microdebris are ubiquitous and the Southern Ocean is no exception. Despite the recent increment in Antarctic studies assessing this threat, there is still scarce information available. Here, we quantified the microdebris in surface water, and their distribution within two bays of Livingston Island (South Shetlands, Antarctica).

Meridianins Inhibit GSK3β In Vivo and Improve Behavioral Alterations Induced by Chronic Stress.

Major depression disorder (MDD) is a severe mental alteration with a multifactorial origin, and chronic stress is one of the most relevant environmental risk factors associated with MDD. Although there exist some therapeutical options, 30% of patients are still resistant to any type of treatment. GSK3β inhibitors are considered very promising therapeutic tools to counteract stress-related affectations.

Would Antarctic Marine Benthos Survive Alien Species Invasions? What Chemical Ecology May Tell Us.

Many Antarctic marine benthic macroinvertebrates are chemically protected against predation by marine natural products of different types. Antarctic potential predators mostly include sea stars (macropredators) and amphipod crustaceans (micropredators) living in the same areas (sympatric). Recently, alien species (allopatric) have been reported to reach the Antarctic coasts, while deep-water crabs are suggested to be more often present in shallower waters.

Leaching material from Antarctic seaweeds and penguin guano affects cloud-relevant aerosol production.

Within the Southern Ocean, the greatest warming is occurring on the Antarctic Peninsula (AP) where clear cryospheric and biological consequences are being observed. Antarctic coastal systems harbour a high diversity of marine and terrestrial ecosystems heavily influenced by Antarctic seaweeds (benthonic macroalgae) and bird colonies (mainly penguins). Primary sea spray aerosols (SSA) formed by the outburst of bubbles via the sea-surface microlayer depend on the organic composition of the sea water surface.

Meridianins Rescue Cognitive Deficits, Spine Density and Neuroinflammation in the 5xFAD Model of Alzheimer's Disease.

Glycogen synthase kinase 3β (GSK3β) is a core protein, with a relevant role in many neurodegenerative disorders including Alzheimer's disease. The enzyme has been largely studied as a potential therapeutic target for several neurological diseases. Unfortunately, preclinical and clinical studies with several GSK3β inhibitors have failed due to many reasons such as excessive toxicity or lack of effects in human subjects.

Computer-Aided Drug Design (CADD) to De-Orphanize Marine Molecules: Finding Potential Therapeutic Agents for Neurodegenerative and Cardiovascular Diseases.

Computer-aided drug design (CADD) techniques allow the identification of compounds capable of modulating protein functions in pathogenesis-related pathways, which is a promising line on drug discovery. Marine natural products (MNPs) are considered a rich source of bioactive compounds, as the oceans are home to much of the planet's biodiversity. Biodiversity is directly related to chemodiversity, which can inspire new drug discoveries.

Distribution of trace elements in benthic infralittoral organisms from the western Antarctic Peninsula reveals no latitudinal gradient of pollution.

Antarctica is considered one of the most pristine regions on Earth, but evidences of global and local anthropogenic pollution exist. Chromium (Cr), lead (Pb) and mercury (Hg) are bioaccumulated and sometimes biomagnified through the trophic web. We aim to determine whether a latitudinal gradient of these trace elements exists in benthic organisms along the rocky shores of the Antarctic Peninsula and the South Shetland Islands.

Epiphytic diatom community structure and richness is determined by macroalgal host and location in the South Shetland Islands (Antarctica).

The marine waters around the South Shetland Islands are paramount in the primary production of this Antarctic ecosystem. With the increasing effects of climate change and the annual retreat of the ice shelf, the importance of macroalgae and their diatom epiphytes in primary production also increases. The relationships and interactions between these organisms have scarcely been studied in Antarctica, and even less in the volcanic ecosystem of Deception Island, which can be seen as a natural proxy of climate change in Antarctica because of its vulcanism, and the open marine system of Livingston Island.

Latitudinal changes in the trophic structure of benthic coastal food webs along the Antarctic Peninsula.

Stable isotopes of C and N have been used to assess the effect of the duration of the sea ice season on the structure of benthic, Antarctic coastal food webs. Samples of suspended particulate organic matter, macroalgae and macroinvertebrates were collected at five subtidal rocky sites across a latitudinal gradient along the western Antarctic Peninsula and among the South Shetland Islands. We tested the hypotheses that trophic positions of omnivores decrease, and food web structure becomes more redundant at higher latitudes.

Bioactive Compounds from Marine Heterobranchs.

The natural products of heterobranch molluscs display a huge variability both in structure and in their bioactivity. Despite the considerable lack of information, it can be observed from the recent literature that this group of animals possesses an astonishing arsenal of molecules from different origins that provide the molluscs with potent chemicals that are ecologically and pharmacologically relevant. In this review, we analyze the bioactivity of more than 450 compounds from ca.

Antibiotic Resistance Genes in Phage Particles from Antarctic and Mediterranean Seawater Ecosystems.

Anthropogenic activities are a key factor in the development of antibiotic resistance in bacteria, a growing problem worldwide. Nevertheless, antibiotics and resistances were being generated by bacterial communities long before their discovery by humankind, and might occur in areas without human influence. Bacteriophages are known to play a relevant role in the dissemination of antibiotic resistance genes (ARGs) in aquatic environments.

Meridianins and Lignarenone B as Potential GSK3β Inhibitors and Inductors of Structural Neuronal Plasticity.

Glycogen Synthase Kinase 3 (GSK3) is an essential protein, with a relevant role in many diseases such as diabetes, cancer and neurodegenerative disorders. Particularly, the isoform GSK3β is related to pathologies such as Alzheimer's disease (AD). This enzyme constitutes a very interesting target for the discovery and/or design of new therapeutic agents against AD due to its relation to the hyperphosphorylation of the microtubule-associated protein tau (MAPT), and therefore, its contribution to neurofibrillary tangles (NFT) formation.

Terpenoids in Marine Heterobranch Molluscs.

Heterobranch molluscs are rich in natural products. As other marine organisms, these gastropods are still quite unexplored, but they provide a stunning arsenal of compounds with interesting activities. Among their natural products, terpenoids are particularly abundant and diverse, including monoterpenoids, sesquiterpenoids, diterpenoids, sesterterpenoids, triterpenoids, tetraterpenoids, and steroids.

Invasive marine species discovered on non-native kelp rafts in the warmest Antarctic island.

Antarctic shallow coastal marine communities were long thought to be isolated from their nearest neighbours by hundreds of kilometres of deep ocean and the Antarctic Circumpolar Current. The discovery of non-native kelp washed up on Antarctic beaches led us to question the permeability of these barriers to species dispersal. According to the literature, over 70 million kelp rafts are afloat in the Southern Ocean at any one time.

Unmasking Antarctic mollusc lineages: novel evidence from philinoid snails (Gastropoda: Cephalaspidea).

Since its introduction, the genus Philine has epitomized numerous mollusc snails with strong morphological convergence. Recently, a molecular analysis including a wide taxon sampling split this group into four non-sister families. Although they are especially diverse in cold and deep waters, no comprehensive studies are available for the Antarctic counterparts.

The Phylum Bryozoa as a Promising Source of Anticancer Drugs.

Recent advances in sampling and novel techniques in drug synthesis and isolation have promoted the discovery of anticancer agents from marine organisms to combat this major threat to public health worldwide. Bryozoans, which are filter-feeding, aquatic invertebrates often characterized by a calcified skeleton, are an excellent source of pharmacologically interesting compounds including well-known chemical classes such as alkaloids and polyketides. This review covers the literature for secondary metabolites isolated from marine cheilostome and ctenostome bryozoans that have shown potential as cancer drugs.