12 research outputs found
Different temporal windows for CB1 receptor involvement in contextual fear memory destabilisation in the amygdala and hippocampus
Reconsolidation is a process in which re-exposure to a reminder causes a previously acquired memory to undergo a process of destabilisation followed by subsequent restabilisation. Different molecular mechanisms have been postulated for destabilisation in the amygdala and hippocampus, including CB1 receptor activation, protein degradation and AMPA receptor exchange; however, most of the amygdala studies have used pre-reexposure interventions, while those in the hippocampus have usually performed them after reexposure. To test whether the temporal window for destabilisation is similar across both structures, we trained Lister Hooded rats in a contextual fear conditioning task, and 1 day later performed memory reexposure followed by injection of either the NMDA antagonist MK-801 (0.1 mg/kg) or saline in order to block reconsolidation. In parallel, we also performed local injections of either the CB1 antagonist SR141716A or its vehicle in the hippocampus or in the amygdala, either immediately before or immediately after reactivation. Infusion of SR141716A in the hippocampus prevented the reconsolidation-blocking effect of MK-801 when performed after reexposure, but not before it. In the amygdala, meanwhile, pre-reexposure infusions of SR141716A impaired reconsolidation blockade by MK-801, although the time-dependency of this effect was not as clear as in the hippocampus. Our results suggest the temporal windows for CB1-receptor-mediated memory destabilisation during reconsolidation vary between brain structures. Whether this reflects different time windows for engagement of these structures or different roles played by CB1 receptors in destabilisation across structures remains an open question for future studies
ATLANTIC EPIPHYTES: a data set of vascular and non-vascular epiphyte plants and lichens from the Atlantic Forest
Epiphytes are hyper-diverse and one of the frequently undervalued life forms in plant surveys and biodiversity inventories. Epiphytes of the Atlantic Forest, one of the most endangered ecosystems in the world, have high endemism and radiated recently in the Pliocene. We aimed to (1) compile an extensive Atlantic Forest data set on vascular, non-vascular plants (including hemiepiphytes), and lichen epiphyte species occurrence and abundance; (2) describe the epiphyte distribution in the Atlantic Forest, in order to indicate future sampling efforts. Our work presents the first epiphyte data set with information on abundance and occurrence of epiphyte phorophyte species. All data compiled here come from three main sources provided by the authors: published sources (comprising peer-reviewed articles, books, and theses), unpublished data, and herbarium data. We compiled a data set composed of 2,095 species, from 89,270 holo/hemiepiphyte records, in the Atlantic Forest of Brazil, Argentina, Paraguay, and Uruguay, recorded from 1824 to early 2018. Most of the records were from qualitative data (occurrence only, 88%), well distributed throughout the Atlantic Forest. For quantitative records, the most common sampling method was individual trees (71%), followed by plot sampling (19%), and transect sampling (10%). Angiosperms (81%) were the most frequently registered group, and Bromeliaceae and Orchidaceae were the families with the greatest number of records (27,272 and 21,945, respectively). Ferns and Lycophytes presented fewer records than Angiosperms, and Polypodiaceae were the most recorded family, and more concentrated in the Southern and Southeastern regions. Data on non-vascular plants and lichens were scarce, with a few disjunct records concentrated in the Northeastern region of the Atlantic Forest. For all non-vascular plant records, Lejeuneaceae, a family of liverworts, was the most recorded family. We hope that our effort to organize scattered epiphyte data help advance the knowledge of epiphyte ecology, as well as our understanding of macroecological and biogeographical patterns in the Atlantic Forest. No copyright restrictions are associated with the data set. Please cite this Ecology Data Paper if the data are used in publication and teaching events. © 2019 The Authors. Ecology © 2019 The Ecological Society of Americ
Catálogo Taxonômico da Fauna do Brasil: setting the baseline knowledge on the animal diversity in Brazil
The limited temporal completeness and taxonomic accuracy of species lists, made available in a traditional manner in scientific publications, has always represented a problem. These lists are invariably limited to a few taxonomic groups and do not represent up-to-date knowledge of all species and classifications. In this context, the Brazilian megadiverse fauna is no exception, and the Catálogo Taxonômico da Fauna do Brasil (CTFB) (http://fauna.jbrj.gov.br/), made public in 2015, represents a database on biodiversity anchored on a list of valid and expertly recognized scientific names of animals in Brazil. The CTFB is updated in near real time by a team of more than 800 specialists. By January 1, 2024, the CTFB compiled 133,691 nominal species, with 125,138 that were considered valid. Most of the valid species were arthropods (82.3%, with more than 102,000 species) and chordates (7.69%, with over 11,000 species). These taxa were followed by a cluster composed of Mollusca (3,567 species), Platyhelminthes (2,292 species), Annelida (1,833 species), and Nematoda (1,447 species). All remaining groups had less than 1,000 species reported in Brazil, with Cnidaria (831 species), Porifera (628 species), Rotifera (606 species), and Bryozoa (520 species) representing those with more than 500 species. Analysis of the CTFB database can facilitate and direct efforts towards the discovery of new species in Brazil, but it is also fundamental in providing the best available list of valid nominal species to users, including those in science, health, conservation efforts, and any initiative involving animals. The importance of the CTFB is evidenced by the elevated number of citations in the scientific literature in diverse areas of biology, law, anthropology, education, forensic science, and veterinary science, among others
Na/K-ATPase as a target for anticancer drugs: studies with perillyl alcohol
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Previous issue date: 2015Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Imunofarmacologia. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Imunofarmacologia. Rio de Janeiro, RJ, Brasil.Universidade Federal Fluminense. Instituto de Biologia. Departamento de Biologia Celular e Molecular. Niterói, RJ, Brasil.Universidade Federal Fluminense. Instituto de Biologia. Departamento de Biologia Celular e Molecular. Niterói, RJ, Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Imunofarmacologia. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Imunofarmacologia. Rio de Janeiro, RJ, Brasil.Universidade Federal Fluminense. Instituto de Biologia. Departamento de Biologia Celular e Molecular. Niterói, RJ, Brasil.Universidade Federal do Rio de Janeiro. Instituto de Química. Departamento de Química Analítica. Rio de Janeiro, RJ, Brasil.Universidade Federal do Rio de Janeiro. Instituto de Química. Departamento de Química Analítica. Rio de Janeiro, RJ, BrasilUniversidade Federal do Rio de Janeiro. Instituto de Ciências Biomédicas. Rio de Janeiro, RJ, Brasil.Universidade Federal do Rio de Janeiro. Instituto de Ciências Biomédicas. Rio de Janeiro, RJ, Brasil.Universidade do Estado do Rio de Janeiro. Faculdade de Ciências Médicas. Departamento de Medicina Interna. Rio de Janeiro, RJ, Brasil.Universidade Federal Fluminense. Instituto de Biologia. Departamento de Biologia Celular e Molecular. Niterói, RJ, Brasil.Background: Na/K-ATPase (NKA) is inhibited by perillyl alcohol (POH), a monoterpene used in the treatment of
tumors, including brain tumors. The NKA α1 subunit is known to be superexpressed in glioblastoma cells (GBM).
This isoform is embedded in caveolar structures and is probably responsible for the signaling properties of NKA
during apoptosis. In this work, we showed that POH acts in signaling cascades associated with NKA that control cell
proliferation and/or cellular death.
Methods: NKA activity was measured by the amount of non-radioactive Rb+ incorporation into cultured GBM cell
lines (U87 and U251) and non-tumor cells (mouse astrocytes and VERO cells). Cell viability was measured by lactate
dehydrogenase levels in the supernatants of POH-treated cells. Activated c-Jun N-terminal Kinase (JNK) and p38
were assessed by western blotting. Apoptosis was detected by flow cytometry and immunocytochemistry, and the
release of interleukins was measured by ELISA.
Results: All four cell types tested showed a similar sensitivity for POH. Perillic acid (PA), the main metabolite of
POH, did not show any effect on these cells. Though the cell viability decreased in a dose-dependent manner when
cells were treated with POH, the maximum cytotoxic effect of PA obtained was 30% at 4 mM. 1.5 mM POH activated
p38 in U87 cells and JNK in both U87 and U251 cells as well as mouse astrocytes. Dasatinib (an inhibitor of the
Src kinase family) and methyl β-cyclodextrin (which promotes cholesterol depletion in cell membranes) reduced
the POH-induced activation of JNK1/2 in U87 cells, indicating that the NKA-Src complex participates in this mechanism.
Inhibition of JNK1/2 by the JNK inhibitor V reduced the apoptosis of GBM cells that resulted from POH administration,
indicating the involvement of JNK1/2 in programmed cell death. 1.5 mM POH increased the production of interleukin
IL-8 in the U251 cell supernatant, which may indicate a possible strategy by which cells avoid the cytotoxic effects of POH.
Conclusions: A signaling mechanism mediated by NKA may have an important role in the anti-tumor action of POH in
GBM cells
Comparing quality of reporting between preprints and peer-reviewed articles in the biomedical literature
Background Preprint usage is growing rapidly in the life sciences; however, questions remain on the relative quality of preprints when compared to published articles. An objective dimension of quality that is readily measurable is completeness of reporting, as transparency can improve the reader's ability to independently interpret data and reproduce findings. Methods In this observational study, we initially compared independent samples of articles published in bioRxiv and in PubMed-indexed journals in 2016 using a quality of reporting questionnaire. After that, we performed paired comparisons between preprints from bioRxiv to their own peer-reviewed versions in journals. Results Peer-reviewed articles had, on average, higher quality of reporting than preprints, although the difference was small, with absolute differences of 5.0% [95% CI 1.4, 8.6] and 4.7% [95% CI 2.4, 7.0] of reported items in the independent samples and paired sample comparison, respectively. There were larger differences favoring peer-reviewed articles in subjective ratings of how clearly titles and abstracts presented the main findings and how easy it was to locate relevant reporting information. Changes in reporting from preprints to peer-reviewed versions did not correlate with the impact factor of the publication venue or with the time lag from bioRxiv to journal publication. Conclusions Our results suggest that, on average, publication in a peer-reviewed journal is associated with improvement in quality of reporting. They also show that quality of reporting in preprints in the life sciences is within a similar range as that of peer-reviewed articles, albeit slightly lower on average, supporting the idea that preprints should be considered valid scientific contributions