The P450 oxidoreductase, RedA, controls development beyond the mound stage in Dictyostelium discoideum

<p>Abstract</p> <p>Background</p> <p>NADPH-cytochrome-P450 oxidoreductase (CPR) is a ubiquitous enzyme that belongs to a family of diflavin oxidoreductases and is required for activity of the microsomal cytochrome-P450 monooxygenase system. CPR gene-disruption experiments have demonstrated that absence of this enzyme causes developmental defects both in mouse and insect.</p> <p>Results</p> <p>Annotation of the sequenced genome of <it>D. discoideum </it>revealed the presence of three genes (<it>redA</it>, <it>redB </it>and <it>redC</it>) that encode putative members of the diflavin oxidoreductase protein family. <it>redA </it>transcripts are present during growth and early development but then decline, reaching undetectable levels after the mound stage. <it>redB </it>transcripts are present in the same levels during growth and development while <it>redC </it>expression was detected only in vegetative growing cells. We isolated a mutant strain of <it>Dictyostelium discoideum </it>following restriction enzyme-mediated integration (REMI) mutagenesis in which <it>redA </it>was disrupted. This mutant develops only to the mound stage and accumulates a bright yellow pigment. The mound-arrest phenotype is cell-autonomous suggesting that the defect occurs within the cells rather than in intercellular signaling.</p> <p>Conclusion</p> <p>The developmental arrest due to disruption of <it>redA </it>implicates CPR in the metabolism of compounds that control cell differentiation.</p

Curcumin-loaded lipid and polymeric nanocapsules stabilized by nonionic surfactants: An In Vitro and In Vivo antitumor activity on B16-F10 melanoma and macrophage uptake comparative study

Curcumin is a polyphenol obtained from the plant Curcuma longa (called turmeric) that displays several pharmacological activities, including anti-inflammatory, antioxidant, antimicrobial and antitumoral activity, but clinical use has been limited by its poor solubility in water and, consequently, minimal systemic bioavailability. We have therefore formulated the drug into nanocarrier systems in an attempt to improve its therapeutic properties. This study evaluates the effect of intraperitoneally administered nanocapsules containing curcumin on subcutaneous melanoma in mice inoculated with B16-F10 cells, and on the cytotoxicity activity against B16-F10 cells in vitro. Phagocytic uptake of formulations was also evaluated upon incubation with macrophage J774 cells by fluorescence microscopy. Lipid and polymeric nanocapsules were prepared by the phase inversion and nanoprecipitation methods, respectively. The uptake of the lipid nanocapsules prepared using Solutol HS15 was significantly reduced in J774 cells. Curcumin, as free drug or as drug-loaded nanocapsules, was administrated at a dose of 6 mg/kg twice a week for 21 days. Free drug and curcuminloaded nanocapsules significantly reduced tumor volume (P < 0.05 vs. control), but no difference was found in the antitumor activity displayed by lipid and polymeric nanocapsules. This assumption was supported by the in vitro study, in which free curcumin as well as loaded into nanocapsules caused significant reduction of cell viability in a concentration- and time-dependent manner.Fil: Mazzarino, Letícia. Universidade Federal de Santa Catarina; BrasilFil: Silva, Luís F. C.. Universidade Federal de Santa Catarina; BrasilFil: Curta, Juliana C.. Universidade Federal de Santa Catarina; BrasilFil: Licínio, Marley A.. Universidade Federal de Santa Catarina; BrasilFil: Costa, Aline. Universidade Federal de Santa Catarina; BrasilFil: Pacheco, Letícia K.. Universidade Federal de Santa Catarina; BrasilFil: Siqueira, Jarbas M.. Universidade Federal de Santa Catarina; BrasilFil: Martinetti Montanari, Jorge Anibal. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Romero, Eder. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología; ArgentinaFil: Assreuy, Jamil. Universidade Federal de Santa Catarina; BrasilFil: Santos Silva, Maria C.. Universidade Federal de Santa Catarina; BrasilFil: Lemos Senna, Elenara. Universidade Federal de Santa Catarina; Brasi

Uso de softwares educativos como ferramenta na construção do conhecimento de educação ambiental

Atualmente, a informação assume um papel cada vez mais importante, com grande crescimento da Internet, multimídia, do ciberespaço, a educação para a cidadania representa a possibilidade de motivar e sensibilizar as pessoas em transformar as diversas formas de participação na defesa da qualidade de vida. Assim, a educação ambiental assume cada vez mais uma função transformadora, na qual a educação e responsabilização dos indivíduos tornam-se um objetivo essencial para promover o desenvolvimento sustentável.Dessa forma, o presente projeto teve por objetivo desenvolver um software educacional chamado “EcoMemória”, com o mesmo princípio de funcionamento do “Jogo Memória” tradicional, para facilitar o aprendizado das noções básicas de Educação Ambiental, visto que há certa dificuldade na abordagem desses conteúdos pelo corpo docente. Como motivos para esta dificuldade podemos citar: a pequena disponibilidade de material didático adequado para ser utilizado em sala de aula e os jogos didáticos desenvolvidos até o momento, não provocarem o devido estímulo a construção da cidadania e desses conhecimentos. Aos estudantes foram aplicados dois questionários previamente elaborados pela equipe. Quando questionados sobre como consideram seu nível de conhecimento em educação ambiental, 80% responderam bom, 10% muito bom, 5% regular, excelente 3% e insuficiente 2%. Entretanto, 75% dos alunos avaliados não têm informações sólidas a respeito de questões ambientais. A aplicação do Jogo EcoMemória foi realizada após uma palestra explicativa sobre Educação Ambiental e alguns aspectos relevantes (tipos de lixo, como economizar água e importância de se reciclar os resíduos, entre outros), posteriormente o jogo foi utilizado como exercício de fixação do conteúdo exposto em sala de aula. Durante a aplicação do Software em sala de aula, houve grande participação dos alunos, assim como foi possível observá-los compartilhando idéias e explorando melhor o conteúdo abordado, sendo assim o jogo EcoMemória obteve aceitação de 75% dos alunos

Agricultura de Precisão: Programas Tecnológicos no Brasil

Precision agriculture (AP) is recognized as a technological innovation tool because when applied in a preventive way during agricultural production, it improves the economic and management aspects, minimizing losses of agricultural inputs and environmental risks in relation to conventional agriculture. This article describes government incentive and free trade programs for assessing productivity, analyzing fertility deficiencies, soil and plant physical and chemical characteristics, as well as evaluating the development of pests and diseases that may occur during production

LC‐HRMS for the Identification of β‐Carboline and Canthinone Alkaloids Isolated from Natural Sources

β-carboline and canthinone alkaloids are widely distributed in the Angiosperms. Due to their diverse biological activities, the structures of these alkaloids have been used as important models for the synthesis of novel therapeutic drugs. Combining high-performance liquid chromatography (HPLC) with high-resolution mass spectrometry (HRMS) has provided a valuable tool in the analysis of these alkaloids in, for example, plants, insects, marine creatures, human tissues and body fluids. In this review, we summarized the main β-carboline and canthinone alkaloids studied by liquid chromatography high-resolution mass spectrometry (LC-HRMS) associated with mass analyzers, molecular weight information, mass fragmentation and biological activities, presenting an overview of increasing interest for carboline alkaloids study by LC-HRMS

Alpinia

Species of the genus Alpinia are widely used by the population and have many described biological activities, including activity against insects. In this paper, we describe the bioactivity of the essential oil of two species of Alpinia genus, A. zerumbet and A. vittata, against Rhodnius nasutus, a vector of Chagas disease. The essential oils of these two species were obtained by hydrodistillation and analyzed by GC-MS. The main constituent of A. zerumbet essential oil (OLALPZER) was terpinen-4-ol, which represented 19.7% of the total components identified. In the essential oil of A. vittata (OLALPVIT) the monoterpene β-pinene (35.3%) was the main constituent. The essential oils and their main constituents were topically applied on R. nasutus fifth-instar nymphs. In the first 10 min of application, OLALPVIT and OLALPZER at 125 μg/mL provoked 73.3% and 83.3% of mortality, respectively. Terpinen-4-ol at 25 μg/mL and β-pinene at 44 μg/mL provoked 100% of mortality. The monitoring of resistant insects showed that both essential oils exhibited antifeedant activity. These results suggest the potential use of A. zerumbet and A. vittata essential oils and their major constituents to control R. nasutus population

The lectin-specific activity of Toxoplasma gondii microneme proteins 1 and 4 binds Toll-like receptor 2 and 4 N-glycans to regulate innate immune priming.

Infection of host cells by Toxoplasma gondii is an active process, which is regulated by secretion of microneme (MICs) and rhoptry proteins (ROPs and RONs) from specialized organelles in the apical pole of the parasite. MIC1, MIC4 and MIC6 assemble into an adhesin complex secreted on the parasite surface that functions to promote infection competency. MIC1 and MIC4 are known to bind terminal sialic acid residues and galactose residues, respectively and to induce IL-12 production from splenocytes. Here we show that rMIC1- and rMIC4-stimulated dendritic cells and macrophages produce proinflammatory cytokines, and they do so by engaging TLR2 and TLR4. This process depends on sugar recognition, since point mutations in the carbohydrate-recognition domains (CRD) of rMIC1 and rMIC4 inhibit innate immune cells activation. HEK cells transfected with TLR2 glycomutants were selectively unresponsive to MICs. Following in vitro infection, parasites lacking MIC1 or MIC4, as well as expressing MIC proteins with point mutations in their CRD, failed to induce wild-type (WT) levels of IL-12 secretion by innate immune cells. However, only MIC1 was shown to impact systemic levels of IL-12 and IFN-γ in vivo. Together, our data show that MIC1 and MIC4 interact physically with TLR2 and TLR4 N-glycans to trigger IL-12 responses, and MIC1 is playing a significant role in vivo by altering T. gondii infection competency and murine pathogenesis