344 research outputs found
AVALIAÇÃO PRELIMINAR DO EXTRATO HIDROALCOÓLICO DE TABERNAEMONTANA CATHARINENSIS NO PROCESSO DE CICATRIZAÇÃO DE FERIDAS EM PELE DE RATOS (RATTUS NORVEGICUS)
A pele representa uma barreira física com o meio externo, quando lesionada, o organismo reage para reparação através do processo de cicatrização. Determinadas plantas que possuem componentes farmacológicos ativos são utilizadas para diminuir o período de cicatrização e para alcançar melhores resultados. O presente trabalho teve como objetivo avaliar a cicatrização de feridas com o extrato de Tabernaemontana catharinensis. Foram utilizados 12 ratos (machos) divididos em 3 grupos experimentais, os quais foram submetidos a incisão na região dorso-costal e feito o tratamento tópico durante 7 dias: Grupo Controle (GC) com salina, Grupo Extrato (GE) com extrato hidroalcoólico de Tabernaemontana catharinensis, Grupo Fármaco (GF) com Bepantanol®. Os animais do GC e GE foram os quais obtiveram maior sucesso em relação a diminuição da área da ferida no decorrer dos dias, sugerindo que a planta tem um efeito cicatrizante importante sobre a epiderme de ratos. 10.5216/ref.v8i3.1580
Multicenter Evaluation of Independent High-Throughput and RT-qPCR Technologies for the Development of Analytical Workflows for Circulating miRNA Analysis.
BACKGROUND:Among emerging circulating biomarkers, miRNA has the potential to detect lung cancer and follow the course of the disease. However, miRNA analysis deserves further standardization before implementation into clinical trials or practice. Here, we performed international ring experiments to explore (pre)-analytical factors relevant to the outcome of miRNA blood tests in the context of the EU network CANCER-ID. METHODS:Cell-free (cfmiRNA) and extracellular vesicle-derived miRNA (EVmiRNA) were extracted using the miRNeasy Serum/Plasma Advanced, and the ExoRNeasy Maxi kit, respectively, in a plasma cohort of 27 NSCLC patients and 20 healthy individuals. Extracted miRNA was investigated using small RNA sequencing and hybridization platforms. Validation of the identified miRNA candidates was performed using quantitative PCR. RESULTS:We demonstrate the highest read counts in healthy individuals and NSCLC patients using QIAseq. Moreover, QIAseq showed 15.9% and 162.9% more cfmiRNA and EVmiRNA miRNA counts, respectively, in NSCLC patients compared to healthy control samples. However, a systematic comparison of selected miRNAs revealed little agreement between high-throughput platforms, thus some miRNAs are detected with one technology, but not with the other. Adding to this, 35% (9 of 26) of selected miRNAs in the cfmiRNA and 42% (11 of 26) in the EVmiRNA fraction were differentially expressed by at least one qPCR platform; about half of the miRNAs (54%) were concordant for both platforms. CONCLUSIONS:Changing of (pre)-analytical methods of miRNA analysis has a significant impact on blood test results and is therefore a major confounding factor. In addition, to confirm miRNA biomarker candidates screening studies should be followed by targeted validation using an independent platform or technology
Interplay between phosphorylation and palmitoylation mediates plasma membrane targeting and sorting of GAP43.
Phosphorylation and lipidation provide posttranslational mechanisms that contribute to the distribution of cytosolic proteins in growing nerve cells. The growth-associated protein GAP43 is susceptible to both phosphorylation and S-palmitoylation and is enriched in the tips of extending neurites. However, how phosphorylation and lipidation interplay to mediate sorting of GAP43 is unclear. Using a combination of biochemical, genetic, and imaging approaches, we show that palmitoylation is required for membrane association and that phosphorylation at Ser-41 directs palmitoylated GAP43 to the plasma membrane. Plasma membrane association decreased the diffusion constant fourfold in neuritic shafts. Sorting to the neuritic tip required palmitoylation and active transport and was increased by phosphorylation-mediated plasma membrane interaction. Vesicle tracking revealed transient association of a fraction of GAP43 with exocytic vesicles and motion at a fast axonal transport rate. Simulations confirmed that a combination of diffusion, dynamic plasma membrane interaction and active transport of a small fraction of GAP43 suffices for efficient sorting to growth cones. Our data demonstrate a complex interplay between phosphorylation and lipidation in mediating the localization of GAP43 in neuronal cells. Palmitoylation tags GAP43 for global sorting by piggybacking on exocytic vesicles, whereas phosphorylation locally regulates protein mobility and plasma membrane targeting of palmitoylated GAP43
The Discursive Legitimation of Political Regimes: A Network Perspective
In this working paper, we treat legitimacy and legitimation as interactive, discursive and relational concepts: Legitimacy is socially constructed in the public spheres of (democratic) political regimes, that is, in discursive exchanges of political elites and citizens about the acceptability of these regimes. Legitimacy claims and assessments establish a link between regimes and their institutions on the one hand, and normative benchmarks on the other. Hence they may be examined with the help of discourse network analysis - a novel application of network analysis whose rationale and potential are illustrated on the basis of a corpus of legitimation statements gleaned from German and US quality newspapers. Our method enables us to discover and visualize the structures of legitimation discourses - prominent speaker types, privileged legitimation criteria and discourse coalitions - and to offer some conjectures on the link between discourses and the institutional arrangements of the German and US polities.Dieses Arbeitspapier behandelt Legitimität und Legitimation als interaktive, diskursive und relationale Konzepte: Legitimität wird in den Öffentlichkeiten (demokratischer) politischer Regimes, also in einem diskursiven Austausch von politischen Eliten und Bürgern über die Akzeptabilität politischer Herrschaft, sozial konstruiert. In Legitimitätsbehauptungen und -bewertungen wird eine Verbindung zwischen Regimes und ihren Institutionen auf der einen und normativen Kriterien auf der anderen Seite hergestellt. Diese können mit Hilfe der Diskursnetzwerkanalyse untersucht werden; Logik und Potential dieser neuen Anwendung der Netzwerkanalyse werden auf der Basis eines Korpus von Legitimationsstatements aus deutschen und US-amerikanischen Qualitätszeitungen illustriert. Unsere Methode erlaubt es, die Strukturen von Legitimationsdiskursen - etwa prominente Sprechertypen, privilegierte Legitimationskriterien und Diskurskoalitionen - aufzudecken und zu visualisieren; daraus lassen sich schließlich auch Erkenntnisse über die Verbindung zwischen Diskursen und politischen Institutionenarrangements in Deutschland und den USA ableiten
The effect of magnesium on early osseointegration in osteoporotic bone: a histological and gene expression investigation
Inositol 1,4,5- Trisphosphate Receptor Function in Drosophila Insulin Producing Cells
The Inositol 1,4,5- trisphosphate receptor (InsP3R) is an intracellular ligand gated channel that releases calcium from intracellular stores in response to extracellular signals. To identify and understand physiological processes and behavior that depends on the InsP3 signaling pathway at a systemic level, we are studying Drosophila mutants for the InsP3R (itpr) gene. Here, we show that growth defects precede larval lethality and both are a consequence of the inability to feed normally. Moreover, restoring InsP3R function in insulin producing cells (IPCs) in the larval brain rescues the feeding deficit, growth and lethality in the itpr mutants to a significant extent. We have previously demonstrated a critical requirement for InsP3R activity in neuronal cells, specifically in aminergic interneurons, for larval viability. Processes from the IPCs and aminergic domain are closely apposed in the third instar larval brain with no visible cellular overlap. Ubiquitous depletion of itpr by dsRNA results in feeding deficits leading to larval lethality similar to the itpr mutant phenotype. However, when itpr is depleted specifically in IPCs or aminergic neurons, the larvae are viable. These data support a model where InsP3R activity in non-overlapping neuronal domains independently rescues larval itpr phenotypes by non-cell autonomous mechanisms
The highly potent AhR agonist picoberin modulates Hh-dependent osteoblast differentiation
Identification and analysis of small molecule bioactivity in target-agnostic cellular assays and monitoring changes in phenotype followed by identification of the biological target are a powerful approach for the identification of novel bioactive chemical matter in particular when the monitored phenotype is disease-related and physiologically relevant. Profiling methods that enable the unbiased analysis of compound-perturbed states can suggest mechanisms of action or even targets for bioactive small molecules and may yield novel insights into biology. Here we report the enantioselective synthesis of natural-product-inspired 8-oxotetrahydroprotoberberines and the identification of Picoberin, a low picomolar inhibitor of Hedgehog (Hh)-induced osteoblast differentiation. Global transcriptome and proteome profiling revealed the aryl hydrocarbon receptor (AhR) as the molecular target of this compound and identified a cross talk between Hh and AhR signaling during osteoblast differentiation
Synthesis of Indomorphan Pseudo Natural Product Inhibitors of Glucose Transporters GLUT‐1 and ‐3
Bioactive compound design based on natural product (NP) structure may be limited due to partial coverage of NP‐like chemical space and biological target space. These limitations can be overcome by combining NP‐centered strategies with fragment‐based compound design through combination of NP‐derived fragments to structurally unprecedented “pseudo natural products” (pseudo‐NPs). We describe the design, synthesis and biological evaluation of a collection of indomorphan pseudo‐NPs that combine biosynthetically unrelated indole‐ and morphan‐alkaloid fragments. Biological investigation in a cell‐based screen for modulators of glucose uptake identified the indomorphane derivative Glupin as potent inhibitor of glucose uptake. Glupin selectively targets and upregulates both, glucose transporters GLUT‐1 and GLUT‐3. Glupin suppresses glycolysis, reduces the levels of glucose‐derived metabolites and attenuates the growth of various cancer cell lines. Our findings underscore the importance of dual GLUT‐1 and GLUT‐3 inhibition to efficiently suppress tumor cell growth and the cellular rescue mechanism, which counteracts glucose scarcity
The pseudo‐natural product rhonin targets RHOGDI
For the discovery of novel chemical matter generally endowed with bioactivity, strategies may be particularly efficient that combine previous insight about biological relevance, e.g., natural product (NP) structure, with methods that enable efficient coverage of chemical space, such as fragment-based design. We describe the de novo combination of different 5-membered NP-derived N-heteroatom fragments to structurally unprecedented “pseudo-natural products” in an efficient complexity-generating and enantioselective one-pot synthesis sequence. The pseudo-NPs inherit characteristic elements of NP structure but occupy areas of chemical space not covered by NP-derived chemotypes, and may have novel biological targets. Investigation of the pseudo-NPs in unbiased phenotypic assays and target identification led to the discovery of the first small-molecule ligand of the RHO GDP-dissociation inhibitor 1 (RHOGDI1), termed Rhonin. Rhonin inhibits the binding of the RHOGDI1 chaperone to GDP-bound RHO GTPases and alters the subcellular localization of RHO GTPases
The pseudo‐natural product rhonin targets RHOGDI
For the discovery of novel chemical matter generally endowed with bioactivity, strategies may be particularly efficient that combine previous insight about biological relevance, e.g., natural product (NP) structure, with methods that enable efficient coverage of chemical space, such as fragment-based design. We describe the de novo combination of different 5-membered NP-derived N-heteroatom fragments to structurally unprecedented “pseudo-natural products” in an efficient complexity-generating and enantioselective one-pot synthesis sequence. The pseudo-NPs inherit characteristic elements of NP structure but occupy areas of chemical space not covered by NP-derived chemotypes, and may have novel biological targets. Investigation of the pseudo-NPs in unbiased phenotypic assays and target identification led to the discovery of the first small-molecule ligand of the RHO GDP-dissociation inhibitor 1 (RHOGDI1), termed Rhonin. Rhonin inhibits the binding of the RHOGDI1 chaperone to GDP-bound RHO GTPases and alters the subcellular localization of RHO GTPases
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