Establishment and validation of cyberknife irradiation in a syngeneic glioblastoma mouse model

CyberKnife stereotactic radiosurgery (CK-SRS) precisely delivers radiation to intracranial tumors. However, the underlying radiobiological mechanisms at high single doses are not yet fully understood. Here, we established and evaluated the early radiobiological effects of CK-SRS treatment at a single dose of 20 Gy after 15 days of tumor growth in a syngeneic glioblastoma-mouse model. Exact positioning was ensured using a custom-made, non-invasive, and trackable frame. One superimposed target volume for the CK-SRS planning was created from the fused tumor volumes obtained from MRIs prior to irradiation. Dose calculation and delivery were planned using a single-reference CT scan. Six days after irradiation, tumor volumes were measured using MRI scans, and radiobiological effects were assessed using immunofluorescence staining. We found that CK-SRS treatment reduced tumor volume by approximately 75%, impaired cell proliferation, diminished tumor vasculature, and increased immune response. The accuracy of the delivered dose was demonstrated by staining of DNA double-strand breaks in accordance with the planned dose distribution. Overall, we confirmed that our proposed setup enables the precise irradiation of intracranial tumors in mice using only one reference CT and superimposed MRI volumes. Thus, our proposed mouse model for reproducible CK-SRS can be used to investigate radiobiological effects and develop novel therapeutic approaches

Deep-sea megabenthos communities of the Eurasian Central Arctic are influenced by ice-cover and sea-ice algal falls

Quantitative camera surveys of benthic megafauna were carried out during the expedition ARK-XXVII/3 to the Eastern Central Arctic Basins with the research icebreaker Polarstern in summer 2012 (2 August-29 September). Nine transects were performed for the first time in deep-sea areas previously fully covered by ice, four of them in the Nansen Basin (3571-4066m) and five in the Amundsen Basin (4041-4384m). At seven of these stations benthic Agassiz trawls were taken near the camera tracks for species identification. Observed Arctic deep-sea megafauna was largely endemic. Several taxa showed a substantially greater depth or geographical range than previously assumed. Variations in the composition and structure of megabenthic communities were analysed and linked to several environmental variables, including state of the sea ice and phytodetritus supply to the seafloor. Three different types of communities were identified based on species dominating the biomass. Among these species were the actiniarian Bathyphellia margaritacea and the holothurians Elpidia heckeri and Kolga hyalina. Variations in megafaunal abundance were first of all related to the proximity to the marginal ice zone. Stations located closer to this zone were characterized by relatively high densities and biomass of B. margaritacea. Food supply was higher at these stations, as suggested by enhanced concentrations of pigments, organic carbon, bacterial cell abundances and nutrients in the sediments. Fully ice-covered stations closer to the North Pole and partially under multi-year ice were characterized by lower concentrations of the same biogeochemical indicators for food supply. These stations nevertheless hosted relatively high density and biomass of the holothurians E. heckeri or K. hyalina, which were observed to feed on large food falls of the sea-ice colonial diatom Melosira arctica. The link between the community structure of megafauna and the extent and condition of the Central Arctic sea-ice cover suggests that future climate changes may substantially affect deep ocean biodiversity

EphrinB2 activation enhances vascular repair mechanisms and reduces brain swelling after mild cerebral ischemia

Objective- Cerebral edema caused by the disruption of the blood-brain barrier is a major complication after stroke. Therefore, strategies to accelerate and enhance neurovascular recovery after stroke are of prime interest. Our main aim was to study the role of ephrinB2/EphB4 signaling in mediating the vascular repair and in blood-brain barrier restoration after mild cerebral ischemia occlusion/reperfusion. Approach and results- Here, we show that the guidance molecule ephrinB2 plays a key role in neurovascular protection and blood-brain barrier restoration after stroke. In a focal stroke model, we characterize the stroke-induced damage to cerebral blood vessels and their subsequent endogenous repair on a cellular, molecular, and functional level. EphrinB2 and its tyrosine kinase receptor EphB4 are upregulated early after stroke by endothelial cells and perivascular support cells, in parallel to their reassembly during neurovascular recovery. Using both retroviral and pharmacological approaches, we show that the inhibition of ephrinB2/EphB4 signaling suppresses post-middle cerebral artery occlusion neurovascular repair mechanisms resulting in an aggravation of brain swelling. In contrast, the activation of ephrinB2 after brain ischemia leads to an increased pericyte recruitment and increased endothelial-pericyte interaction, resulting in an accelerated neurovascular repair after ischemia. Conclusions- We show that reducing swelling could result in improved outcome because of reduction in damaged brain tissue. We also identify a novel role for ephrinB2/EphB4 signaling in the maintenance of the neurovascular homeostasis and provide a novel therapeutic approach in reducing brain swelling after stroke

Benthic megafauna of the western Clarion-Clipperton Zone, Pacific Ocean

There is a growing interest in the exploitation of deep-sea mineral deposits, particularly on the abyssal seafloor of the central Pacific Clarion-Clipperton Zone (CCZ), which is rich in polymetallic nodules. In order to effectively manage potential exploitation activities, a thorough understanding of the biodiversity, community structure, species ranges, connectivity, and ecosystem functions across a range of scales is needed. The benthic megafauna plays an important role in the functioning of deep-sea ecosystems and represents an important component of the biodiversity. While megafaunal surveys using video and still images have provided insight into CCZ biodiversity, the collection of faunal samples is needed to confirm species identifications to accurately estimate species richness and species ranges, but faunal collections are very rarely carried out. Using a Remotely Operated Vehicle, 55 specimens of benthic megafauna were collected from seamounts and abyssal plains in three Areas of Particular Environmental Interest (APEI 1, APEI 4, and APEI 7) at 3100–5100 m depth in the western CCZ. Using both morphological and molecular evidence, 48 different morphotypes belonging to five phyla were found, only nine referrable to known species, and 39 species potentially new to science. This work highlights the need for detailed taxonomic studies incorporating genetic data, not only within the CCZ, but in other bathyal, abyssal, and hadal regions, as representative genetic reference libraries that could facilitate the generation of species inventories.</jats:p

FUN Azores: a FUNctional Trait Database for the Meio-, Macro-, and Megafauna From the Azores Marine Park (Mid-Atlantic Ridge)

Trait-based approaches that complement taxonomy-based studies have increased in popularity among the scientific community over the last decades. The collection of biological and ecological characteristics of species (i.e., traits) provides insight into species and ecosystem vulnerability to environmental and anthropogenic changes, as well as ecosystem functioning. Here, we present the FUN Azores trait database, describe our approach, evaluate its scope, compare it to other marine trait databases, and explore the spatial distribution of its traits with “functional maps.” While most of the available trait databases to date contain essential information to understand the functional diversity of a taxonomic or functional group, our ecosystem-based approach provides a comprehensive assessment of diverse fauna (i.e., meio-, macro-, and megafauna) from benthic and pelagic environments in the Azores Marine Park; including ridges, seamounts, hydrothermal vents, and the overlying water column. We used a collaborative approach involving 30 researchers with different expertise to develop the FUN Azores database, which contains compiled data on 14 traits representing morphological, behavioral, and life history characteristics for 1,210 species across 10 phyla. The “functional maps” show a distinct distribution of the two most common size classes, suggesting different communities with different functionalities. The following traits had the best scoring coverage (i.e., \u3e95% of OPEN ACCESS EDITED BY Peter Convey, British Antarctic Survey (BAS), United Kingdom REVIEWED BY Sarah Faulwetter, University of Patras, Greece Kai Horst George, Senckenberg am Meer Wilhelmshaven, Germany *CORRESPONDENCE Neus Campanyà-Llovet [email protected] RECEIVED 21 September 2022 ACCEPTED 29 May 2023 PUBLISHED 27 July 2023 CITATION Campanyà-Llovet N, Bates AE, Cuvelier D, Giacomello E, Catarino D, Gooday AJ, Berning B, Figuerola B, Malaquias MAE, Moura CJ, Xavier JR, Sutton TT, Fauconnet L, Ramalho SP, Neves BdM, Machado GM, Horton T, Gebruk AV, Minin K, Bried J, Molodtsova T, Silva MA, Dilman A, Kremenetskaia A, Costa EFS, Clarke J, Martins HR, Pham CK, Carreiro-Silva M and Colaço A (2023) FUN Azores: a FUNctional trait database for the meio-, macro-, and megafauna from the Azores Marine Park (Mid-Atlantic Ridge). Front. Ecol. Evol. 11:1050268. doi: 10.3389/fevo.2023.1050268 COPYRIGHT © 2023 Campanyà-Llovet, Bates, Cuvelier, Giacomello, Catarino, Gooday, Berning, Figuerola, Malaquias, Moura, Xavier, Sutton, Fauconnet, Ramalho, Neves, Machado, Horton, Gebruk, Minin, Bried, Molodtsova, Silva, Dilman, Kremenetskaia, Costa, Clarke, Martins, Pham, Carreiro-Silva and Colaço. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms. TYPE Data Report PUBLISHED 27 July 2023 DOI 10.3389/fevo.2023.1050268 Campanyà-Llovet et al. 10.3389/fevo.2023.1050268 Frontiers in Ecology and Evolution 02 frontiersin.org the species scored): maximum body size, body form, skeleton material, feeding structure, motility, environmental position, substratum affinity, distribution, and depth range; while traits related to species behavior (e.g., sociability or aggregation tendencies) and life history (e.g., developmental mechanism) had lower scoring coverage, highlighting the need for further research to fill these knowledge gaps. We found a larger number of species in the benthic compared to the pelagic environment and differing species composition between areas within the Azores Marine Park resulting from varying biodiversity, ecosystem types, sampling effort, and methodologies used. The FUN Azores database will foster and facilitate trait-based approaches in the area, develop a framework for expansion of cross-ecosystem and cross-taxa trait databases elsewhere, and improve our ecological understanding of the Azores Marine Park and its conservation requirements