Top PDF Characterization of apoptosis-related oxidoreductases from Neurospora crassa.

Characterization of apoptosis-related oxidoreductases from Neurospora crassa.

Characterization of apoptosis-related oxidoreductases from Neurospora crassa.

of three more genes encoding putative oxidoreductases envisages significant genetic interactions between themselves and with the alternative dehydrogenases that may provide clues as to their function in Neurospora. Thus, we found it appropriate to assess the expression profile of alternative dehydrogenases and AIF-like genes in the different mutant strains (Fig. 4). We decided not to include amid2 in the expression profile study because, as stated before, it is a heterokaryotic strain with consequent heterogeneity in gene content. Each gene expression profile was evaluated in both early and late exponential phases of growth as we have previously demonstrated that expression of genes encoding mitochondrial respiratory enzymes varies widely depending on the stage of growth [36]. In addition, we have previously provided evidence that among mitochondrial NAD(P)H dehydrogenases, complex I (nuo-51 transcript) appears to be the most abundant and that, with the exception of nde-3, genes encoding these enzymes are significantly downregulated from early to late exponential stage of growth [36,40]. Herein, we show that AIF-like encoding genes are also downregulated from early to late exponential stage of growth, suggesting that the early exponential stage of growth in Neurospora is a period of soaring transcription events. Clearly, and corroborating the phylogenetic analysis depicted in Fig. 1B, the two classes of genes compensate among themselves. An analysis of the expression profiles in the various mutant strains provides evidence that there is an overall compensation concern- ing alternative dehydrogenases. Likewise, aif, amid and amid-2 appear up regulated in each other mutant strains suggestive of overlapping roles and compensatory regulation mechanisms. Interestingly, expression of AIF-like encoding genes appears significantly up regulated in a triple mutant devoid of NDI1, NDE1 and NDE2 (Fig. 4), although we were not able to associate this increase with an obvious phenotype. Our most striking result concerns the expression of nde-3. Indeed, its expression does not appear to be regulated according to the remaining NAD(P)H dehydrogenases since we could not detect any expression variation in the respective respiratory mutants. In contrast, we observed a robust increase in the expression pattern of nde-3 in aif and amid mutants, suggesting that NDE3 may be functionally redundant to AIF-like proteins. More so, these results once again corroborate the phylogenetic analysis depicting NDE3 as clustering with AIF and AMID proteins rather than with alternative NAD(P)H dehydrogenases (Fig. 1B).
Mostrar mais

9 Ler mais

Biochemical characterization of Neurospora crassa glycogenin (GNN), the self-glucosylating initiator of glycogen synthesis

Biochemical characterization of Neurospora crassa glycogenin (GNN), the self-glucosylating initiator of glycogen synthesis

To identify the acceptor site of glucose in the self-glucosyla- tion reaction, we used the GNND360 protein fused to GST. The full-length protein is so susceptible to proteolysis when produced in E. coli that it is impossible to produce more than a complex mixture of proteolytically related species. Therefore, we used a truncated form of GNN (GNND360), which lacks 304 amino acids from the C-terminal region and which we know to be catalytically active [13]. This form still undergoes some proteolysis to generate another species but this did not interfere with the analysis. The GST-GNND360 was allowed to self-glucosylate and the band corresponding to the non-pro- teolysed protein was excised from the SDS–PAGE gel, and analyzed by mass spectroscopy after trypsin digestion. A pep- tide corresponding to amino acid residues 179–203 (NTYNRLSFTYNVTPSAHYQYIPAYK) was identified in GNN to be modified by addition of glucose residues. This pep- tide still contains an arginine residue (Arg183) that is, most likely, a missed site for trypsin cleavage. This peptide contains the Tyr196 residue that aligns with Tyr194 and Tyr232, which were demonstrated to be the glucosylation sites in the rabbit skeletal muscle glycogenin [6], and in the yeast Glg2p [7] pro- teins, respectively. The mass spectrum (Fig. 2) indicated the presence of a peak corresponding to the parent peptide (3013.38 atomic mass observed) and seven additional ions of higher mass. The peaks represented a successive increase of 162 mass units, which corresponds to the mass difference of one additional glucose residue. The signal corresponding to +7 glu- coses is considerably weaker and the most prominent peak cor- responded to the parent peptide plus two glucose residues. Sequencing of the peptide showed that the Tyr196 residue was the primary modified residue (not shown).
Mostrar mais

7 Ler mais

Expressão e purificação de proteínas recombinantes do organismo modelo Neurospora crassa

Expressão e purificação de proteínas recombinantes do organismo modelo Neurospora crassa

Model organisms are those considered representatives to fundamental attributes of the kingdoms of organisms or even life itself. Among model organisms, the early works of George W. Beadle and Edward L. Tatum with the fungus Neurospora crassa stimulated the use of microorganisms and has initiated a new era, combining genetics and biochemistry. The fungus N. crassa is easy to grow, showing greater morphological and developmental complexity due to its multicellular characteristics. Moreover, many proteins are predicted as similar proteins in animals, plants and other filamentous fungi. This information emphasizes the potential of N. crassa as a model for elucidation of still unknown biochemical and genetic mechanisms. However, 41% of the analyzed proteins are related to known proteins. Another 30% are hypothetical proteins with no similarity to proteins deposited in databases. Among metabolic pathways targets of studies in Neurospora, an interesting feature is the glycogen metabolism. Under stress conditions, the temperature (heat shock), the glycogen concentration decreases, while in yeast the behavior is opposite. Thus, studies have identified proteins involved in these pathways. The Importin-α protein is important because of its role in recognizing proteins to be transported from the cytoplasm to the cell nucleus. Its study is important as it participates in the transport of proteins involved in the regulation of glycogen metabolism. Another protein is NCU03482, which is identified as a helicase RuvB-like protein, which is responsible for the remodeling of chromatin in human protein. In this work, the expression and purification of recombinant protein Importin-α (Imp-α) and NCU03482 were performed, and the circular dichroism experiment with the sample of Imp-α. Results indicate that the proteins were expressed in Escherichia coli successfully, as well as purification of them. However, among the proteins, the Imp-α was obtained in a concentration suitable for other experiments, while NCU03482 was unstable in solution, precipitating after purification. The circular dichroism confirmed the folding Imp-α, as expected for this protein, validating the viability of the sample for future experiments in crystallography and protein-protein interaction. The characterization of these molecules is important for understanding of the metabolic pathway of glycogen and other mechanisms still not described in Neurospora, which may be related to other Eukaryotic organisms.
Mostrar mais

31 Ler mais

Review of Prodigiosin, Pigmentation in Serratia marcescens

Review of Prodigiosin, Pigmentation in Serratia marcescens

in water and soil, on plant, in insects and in man and animal [3] . S. marcescens is the only pathogenic species, although rare reports of infection with S. plymuthica, liquefaciens, rubidaea and odifera exist. Since the early 1900’s, physicians have used S. marcescens to study transmission of microorganisms, as it was assumed to be a harmless saprophyte. In the hospital, Serratia tends to colonize the respiratory and urinary tracts of adults, rather than the GI tract. Serratia sp is responsible for 1.4% of nosocomial septicemia. It is also responsible for 2% of lower respiratory, urinary tract and surgical wound infections. Serratia sp can be a cause of meningitis, especially after surgical intervention. Also reported is endocarditis and osteomyelitis in heroin addicts. Crude mortality for Serratia septicemia is 26%, while the mortality for meningitis and endocarditis is very high [4] . S. marcescens and S. liquefaciens may
Mostrar mais

13 Ler mais

The guanine nucleotide exchange factor RIC8 regulates conidial germination through Gα proteins in Neurospora crassa.

The guanine nucleotide exchange factor RIC8 regulates conidial germination through Gα proteins in Neurospora crassa.

We observed that loss of any single G protein subunit has no effect on conidial morphology in N. crassa. However, loss of both gna-1 and gna-3 Ga genes leads to a dramatic increase in arthroconidia formation, which is also observed in the Dric8 mutant. Arthroconidia are formed by the fragmentation of vegetative hyphae [23] and their production is proposed to be a default pathway in mutants defective in macroconidiation [24]. Expression of constitutively active (GTPase deficient) GNA-1 or GNA-3 in the Dric8 mutant background does not lead to reduced arthroconidiation, suggesting RIC8 controls arthroconidia forma- tion through Ga-dependent and independent mechanisms. While the exact mechanism by which RIC8 and the Ga proteins negatively regulate arthroconidiation is unclear, it may involve the MAK-1 MAP kinase signaling pathway, as deletion of any of the three kinases of this pathway leads to an overproduction of arthroconidia [35]. Additionally, loss of rgb-1, homologous to the B subunit of type 2A Ser/Thr phosphatases, also leads to production Figure 8. Localization of Ga proteins in germinating conidia. Conidia from strains expressing GNA-1-TagRFP, GNA-2-TagRFP, GNA-3-TagRFP and untransformed controls were inoculated on solid medium and analyzed after 0, 4, 6 and 8 h of growth. Images were captured by bright field and the 543 nm HyD laser using the Leica TCS SP5 II inverted confocal microscope. The arrowhead, asterisk and solid arrow correspond to plasma membrane, vacuole and septa localization, respectively. Panels are only shown for time points in which fluorescence can be detected above background. All panels are 46 zoom, with the exception of GNA-1 at 8 h, which is 26. Scale bar = 5 mm.
Mostrar mais

13 Ler mais

Exploring NADH:quinone oxidoreductases

Exploring NADH:quinone oxidoreductases

Complex I (NADH:quinone oxidoreductase, EC. 1.6.5.3) plays a central role in the energy transduction processes of the respiratory chains from mitochondria and many bacteria and it dysfunction has been implicated in a wide range of pathologies such as Leigh’s disease and neurodegenerative diseases [1]. Complex I functions as an entry point for electrons into those respiratory chains and catalyzes the two electron oxidation of NADH and the reduction of quinone, coupled to charge translocation from the negatively charged side (N-side, prokaryotic cytoplasm or mitochondrial matrix) to the positively charged side (P-side, prokaryotic periplasm or mitochondrial intermembrane space) of the membrane. This process results in the establishment of a transmembrane difference of electrochemical potential. It is an L-shaped membrane protein, consisting of a peripheral and a membrane arm. The peripheral arm contains a series of iron-sulfur centers and a FMN at the catalytic site, where NADH is oxidized [2]. The membrane arm includes the cation translocating machinery [3, 4].
Mostrar mais

421 Ler mais

The NDR kinase scaffold HYM1/MO25 is essential for MAK2 map kinase signaling in Neurospora crassa.

The NDR kinase scaffold HYM1/MO25 is essential for MAK2 map kinase signaling in Neurospora crassa.

A similar cell fusion deficiency is described for strains defective in components of the MAK1 cell wall integrity MAP kinase pathway [12,46]. However, the relationship between the MAK1 and MAK2 MAP kinase modules during hyphal fusion is unresolved. To test if HYM1 might influence the activity of these signaling modules, we compared the phosphorylation status of the two MAP kinases in wild type and Dhym-1 by using phospho- specific antibodies against the activated proteins. In wild type cells, MAK1 and MAK2 displayed basal activities that can be Figure 1. HYM1 functions as scaffold protein for the COT1- POD6 complex. (A) Yeast two hybrid tests identify HYM1 as direct interaction partner of COT1 or POD6. Genes cloned into pGBKT7 and pGADT7 (mentioned as first or second label, respectively) were co- expressed as fusion proteins with the GAL4 DNA-binding domain and activation domains, respectively. Plasmids expressing the indicated proteins either as prey or as bait alone were used as negative controls and pGBKT7-53 (murine p53) and pGADT7-recT (SV40 large T antigen) fusion proteins as positive control. (B) Co-immunoprecipitation of GFP- tagged HYM1 recovered the small and large isoform of myc-COT1 and HA-POD6 from N. crassa cell extracts indicating the formation of a COT1-POD6-HYM1 complex in vivo. (C) Kinase activity assay of myc- COT1 purified from the indicated strains. Data represent means of five independent experiments (standard deviations are indicated as bars; the star denotes significantly different COT1 activity in the tested strains (p,0,01; unpaired Student’s t-test). (D) Reciprocal anti-myc and anti-HA immunoprecipitation experiments from strains co-expressing myc- COT1 and HA-POD6 in a Dhym-1 background failed to recover HA- POD6 and myc-COT1, respectively. (E) COT1-GFP accumulated at the hyphal tip as bright spot at the distal side of the Spitzenko¨rper (co- stained with the marker dye FM4-64) and as apex-associated crescent. HYM1, in contrast, did not form this apex-associated crescent and its apical localization fully coincided with the Spitzenko¨rper. Note that both proteins co-localized at constricting septa (Videos S1, S2). COT1-GFP in a Dhym-1 background still accumulated as a bright spot at the distal side of the Spitzenko¨rper and as an apex-associated crescent at the hyphal tip.
Mostrar mais

14 Ler mais

Neolignans isolated from twigs of Nectandra leucantha Ness Mart (Lauraceae) displayed in vitro antileishmanial activity

Neolignans isolated from twigs of Nectandra leucantha Ness Mart (Lauraceae) displayed in vitro antileishmanial activity

Leishmaniasis is a neglected tropical disease (NTD) that affects more than one billion people in tropical and sub- tropical countries, including parts of Latin America, Africa and Asia [1, 2]. This disease is caused by protozoa of the genus Leishmania and transmitted by the bite of infected sandflies. The World Health Organization esti- mated 1.3 million new cases annually, divided into 300,000 cases of visceral leishmaniasis and 1 million cases of cutaneous leishmaniasis. [2]. The therapeutic ar- senal for the treatment of leishmaniasis is limited and still unsatisfactory. The treatment is not only challenging and long, but also offers a reduced option of drugs, most of which are toxic such as antimonials, amphotericin B, pentamidine and miltefosine [3, 4]. Considering this problematic context and lack of interest from the pharmaceutical sector, the search for novel drugs is cru- cial [5]. Based on this aspect, natural products may be considered an interesting source of new molecules for the development of scaffolds for protozoal diseases, in- cluding leishmaniasis. Previous studies by our group per- formed on the n-hexane extract from twigs of Nectandra leucantha (Lauraceae) yielded three neo- lignans with significant antileishmanial and immuno- modulatory activity against Leishmania (L.) donovani [6]. Additionally, these related compounds displayed ac- tivity against Trypanosoma cruzi [7]. As part of our con- tinuous studies of N. leucantha, in the present work, the crude n-hexane extract from twigs of this plant displayed activity against promastigote and amastigote forms of L. (L.) infantum (death rate of 100% at 300 μg/mL). Aiming to characterize its bioactive compounds, the crude ex- tract was subjected to dereplication procedures using HPLC/HRESIMS to enable the identification of six re- lated neolignans (1 – 6 ). Since there was no information concerning the potential of these neolignans against amastigote forms of L. (L.) infantum, the crude bioactive extract was fractionated using different chromatographic methods to obtain pure 1 – 6 . Antileishmanial activity and cytotoxicity of each isolated compound was evalu- ated in vitro and the important chemical features related to the antileishmanial activity of these related natural products were determined.
Mostrar mais

7 Ler mais

Caracterização funcional do produto da ORF NCU03043 de Neurospora crassa homólogo ao fator de transcrição FlbC de Aspergillus nidulans

Caracterização funcional do produto da ORF NCU03043 de Neurospora crassa homólogo ao fator de transcrição FlbC de Aspergillus nidulans

a presença de poucos microconídios, formação de hifas aéreas reduzidas, morfologia das extremidades das hifas alterada, aspecto e morfologia alterados das colônias e produção acentuada do pigmento melanina, indicando que a proteína FLBC desempenha importante papel no desenvolvimento do fungo. O fator de transcrição FLBC, objeto de estudo deste trabalho, é uma proteína homóloga às proteínas FlbC e FLE1 dos fungos Aspergillus nidulans e Podospora anserina, respectivamente, ambas envolvidas nos processos de conidiação e desenvolvimento dos fungos. O objetivo deste trabalho foi realizar uma caracterização funcional detalhada deste fator de transcrição em N. crassa. Análises de expressão gênica mostraram níveis elevados do transcrito flbC durante o crescimento vegetativo do fungo e após a indução do desenvolvimento assexual. A linhagem nocaute mostrou uma desregulação no acúmulo de carboidratos de reserva (glicogênio e trehalose) durante o crescimento vegetativo do fungo, apresentando níveis elevados dos dois carboidratos. Análises de expressão gênica nas linhagens selvagem e flbC KO mostrou que os
Mostrar mais

28 Ler mais

Estudos estruturais com a importina-α e Sequências de Localização Nuclear (NLS) de proteínas envolvidas no metabolismo de Neurospora crassa

Estudos estruturais com a importina-α e Sequências de Localização Nuclear (NLS) de proteínas envolvidas no metabolismo de Neurospora crassa

Proteínas que apresentam atividades no núcleo e possuem sequência de localização nuclear (NLS) tem seu deslocamento dependente do heterodímero importina-α/β. A importina- (ImpA) é responsável pelo reconhecimento inicial do substrato a ser importado através da interação com os NLS. Os sinais são caracterizados por apresentar um ou mais grupos de aminoácidos básicos, denominados como sequências monopartidas e bipartidas. O fungo Neurospora crassa vem sendo utilizado há mais de 70 anos como organismo modelo em estudos de expressão gênica, desenvolvimento e diferenciação celular, ritmo circadiano, defesa do genoma, bem como outros aspectos da biologia de eucariotos. A presença de um grande número de genes no genoma de N. crassa ainda com funções desconhecidas aponta este organismo como um promissor modelo para o estudo de novos mecanismos genéticos e bioquímicos ainda não identificados. Considerando a importância do metabolismo do glicogênio para os organismos, o presente trabalho teve como objetivo o estudo estrutural de complexos de ImpA com peptídeos NLSs (NCM e NCB) de proteínas envolvidas no metabolismo de glicogênio do fungo N. crassa , utilizando técnicas de cristalografia de proteínas. Monocristais dos complexos ImpA-NCM e ImpA-NCB foram obtidos para a coleta dos dados de difração de raios-X, resultando em dois conjuntos de dados à 2,1Å e 2,45Å de resolução, respectivamente. Após elucidação da estrutura da ImpA, mapas de densidade eletrônica gerados revelaram uma densidade eletrônica no sítio principal de reconhecimento de NLS da ImpA de ambas estruturas, possibilitando modelagem dos peptídeos. Em uma comparação do mapa de densidade eletrônica obtido de ambos complexos com um mapa de uma estrutura nativa de ImpA (70- 529) coletada à 2,0Å de resolução, a qual usualmente apresenta um peptídeo “contaminante” no sitio de ligação, foi constatada uma semelhança entres as densidades do sítio de ligação principal, com exceção da densidade ocupada pelo resíduos Lys 232 E Lys 546 dos peptídeos NCM e NCB respectivamente. Isso sugere
Mostrar mais

23 Ler mais

Characterization of the Neurospora crassa cell fusion proteins, HAM-6, HAM-7, HAM-8, HAM-9, HAM-10, AMPH-1 and WHI-2.

Characterization of the Neurospora crassa cell fusion proteins, HAM-6, HAM-7, HAM-8, HAM-9, HAM-10, AMPH-1 and WHI-2.

The ham-9 gene encodes an 869-amino-acid protein containing a SAM domain and two PH domains. The SAM domain has been identified in yeast Ste11p (S. cerevisae homolog of N. crassa NRC- 1) [61], and the PH domains have been suggested to play a role in targeting signal transduction proteins to intracellular membrane in signaling events [62]. The C-terminal GFP-tagged and N-terminal RFP-tagged HAM-9 fusion proteins were not functional, preclud- ing any live-imaging analysis. HA-HAM-9 was expressed in both vegetative hyphae and germ tubes/CATs (Figure 3), but its Figure 10. Schematic model for the regulatory network involved in CAT fusion. PP-1, ADV-1, SNF-5, and RCO-1/RCM-1 are transcription factors required for CAT fusion. MIK-1/MEK-1/MAK-1 and NRC-1/MEK-2/MAK-2 are two MAP kinase pathways required for CAT fusion. HAM-2/HAM-3/ HAM-4/MOB-3/PP2A/PPG-1 form the STRIPAK complex that regulates MAK-1 nuclear accumulation. HAM-1/SO and MAK-2 engage in Ping-Pong signaling behavior during CAT fusion. HAM-6/HAM-7/HAM-8 are required at the plasma membrane/cell wall for MAK-1 pathway activation. HAM-10 may regulate vesicular trafficking and could potentially respond to calcium signaling during cell fusion. AMPH-1 regulates vesicular trafficking and endocytosis during cell fusion. WHI-2 may regulate the MAP kinase pathways through a general stress response pathway. The role of HAM-9 during CAT fusion remains to be determined.
Mostrar mais

15 Ler mais

Efeito da L- aminoácido oxidase de Calloselasma rhodostoma (CR-LAAO) na indução de...

Efeito da L- aminoácido oxidase de Calloselasma rhodostoma (CR-LAAO) na indução de...

FADD (Fas-associated death domain), sendo responsáveis pelas alterações bioquímicas que ocorrem na membrana plasmática, organelas, citoplasma e núcleo das células em apoptose (MARTIN et al., 1996; CULLEN et al., 2010). As caspases executoras, após serem ativadas, clivam substratos celulares necessários para o funcionamento normal das células, como proteínas estruturais do citoesqueleto e proteínas nucleares. Além disso, as caspases podem ativar enzimas como as DNAses, que clivam o DNA, resultando em eventos bioquímicos que levam ao surgimento dos fragmentos de DNA oligossomais, uma das principais características da apoptose (RICCARDI; NICOLETTI, 2006). As proteínas chamadas IAPs (Inhibitors of apoptosis), como Xiap, Ciap-1 e Ciap-2, inibem a ativação das caspases (HERR; DEBATIN, 2001).
Mostrar mais

39 Ler mais

Reactive oxygen species, apoptosis and cancer

Reactive oxygen species, apoptosis and cancer

signals and is conducted through two major pathways: mito- chondrial (intrinsic) or death receptor pathway (extrinsic). Ex- trinsic pathway of apoptosis is triggered by interaction of death receptor and its ligand in cellular plasma membrane 16 , which activates nicotinamide adenine dinucleotide phosphate (NADPH) oxidase and generation of ROS. This further leads to activation of acid sphingomielinase, generation of ceramide and clustering of the receptors. The described processes form signal platform that induces apoptotic cascade 17 . Activation of NF- țB survival path increases the transcription of anti- apoptotic proteins (FLIP, MnSOD, Bcl-X, IAP) and blocks the apoptosis. In the presence of high ROS concentrations, the im- possibility of NF- țB induction triggers the activation of ASK1/JNK kinases, which initiates apoptosis 18 .
Mostrar mais

4 Ler mais

Influence of vitamin D on cell cycle, apoptosis, and some apoptosis related molecules in systemic lupus erythematosus

Influence of vitamin D on cell cycle, apoptosis, and some apoptosis related molecules in systemic lupus erythematosus

The distribution of DNA content in cell cycle was determined using propidium iodide P) as a DNA‐ binding dye. Briefly, lymphocytes × cells were incubated with vitamin D nM for hr, the optimal dose of vitamin D and time of incubation was optimized in our lab in previous studies . Then harvested cells were washed twice with cold phosphate‐buffered saline PBS , incubated with µg/ml RNAse A GenetBio Co., Nonsan, Korea for min at ° C and subsequently incubated with P)

5 Ler mais

VIB1, a link between glucose signaling and carbon catabolite repression, is essential for plant cell wall degradation by Neurospora crassa.

VIB1, a link between glucose signaling and carbon catabolite repression, is essential for plant cell wall degradation by Neurospora crassa.

Filamentous fungi that thrive on plant biomass are the major producers of hydrolytic enzymes used to decompose lignocellulose for biofuel production. Although induction of cellulases is regulated at the transcriptional level, how filamentous fungi sense and signal carbon-limited conditions to coordinate cell metabolism and regulate cellulolytic enzyme production is not well characterized. By screening a transcription factor deletion set in the filamentous fungus Neurospora crassa for mutants unable to grow on cellulosic materials, we identified a role for the transcription factor, VIB1, as essential for cellulose utilization. VIB1 does not directly regulate hydrolytic enzyme gene expression or function in cellulosic inducer signaling/processing, but affects the expression level of an essential regulator of hydrolytic enzyme genes, CLR2. Transcriptional profiling of a Dvib-1 mutant suggests that it has an improper expression of genes functioning in metabolism and energy and a deregulation of carbon catabolite repression (CCR). By characterizing new genes, we demonstrate that the transcription factor, COL26, is critical for intracellular glucose sensing/metabolism and plays a role in CCR by negatively regulating cre-1 expression. Deletion of the major player in CCR, cre-1, or a deletion of col-26, did not rescue the growth of Dvib-1 on cellulose. However, the synergistic effect of the Dcre-1; Dcol-26 mutations circumvented the requirement of VIB1 for cellulase gene expression, enzyme secretion and cellulose deconstruction. Our findings support a function of VIB1 in repressing both glucose signaling and CCR under carbon-limited conditions, thus enabling a proper cellular response for plant biomass deconstruction and utilization.
Mostrar mais

15 Ler mais

DESMATAMENTO EM FLORESTA OMBRÓFILA MISTA NA REGIÃO SERRANA DE SANTA CATARINA

DESMATAMENTO EM FLORESTA OMBRÓFILA MISTA NA REGIÃO SERRANA DE SANTA CATARINA

ABSTRACT – Since the enactment of Law No. 11,428/06, an expectation was created as to whether more restricted rules on the use and conservation of the Atlantic Forest Biome would be sufficient to reduce deforestation. In the same sense, the inspection bodies stood out due to their responsibility in the application of this important legal instrument. In this context, the objectives of this study were: 1) to analyze the history of deforestation in the Planalto Serrano of the State of Santa Catarina, whose forest covered area is characterized by the Mixed Ombrophilous Forest, after the validity of Law 11,428/06; 2) to verify the application of the Law in the occurrence of deforestation, and 3) to identify the reasons for deforestation. A documentary research was carried out on 543 criminal procedures instituted by the Environmental Military Police for deforestation between December 2006 and December 2015. From each criminal case the following data were extracted: date, number of occurrences per year and municipality, size, successional stage of the deforested area, motive and land use of deforested areas. The results indicated that there was an accentuated reduction of 58% in the number of deforestation between 2007 and 2015. However, the selective cutting of Araucaria angustifolia (Bertol.) Kuntze was predominant with a percentage of 62.07% of the total number of occurrences. It was also verified that 71.46% of deforestation reached the middle stage of forest regeneration. In most case (33%), the reason for deforestation was for commercial purposes. The law for the protection of the Atlantic Forest Biome, conjunctly with the inspection, contributed to reduce deforestation and the cut of araucarias. Nevertheless, advancements are still needed, especially in the recovery of deforested areas, since only 28% of deforested areas were effectively restored.
Mostrar mais

12 Ler mais

Effect of byrosima crassa and phenolic constituents on helicobacter pylori: induced neutrophils oxdative burst

Effect of byrosima crassa and phenolic constituents on helicobacter pylori: induced neutrophils oxdative burst

H. pylori type strain ATCC 43504, which is metronidazole resistant (MtzR) and amoxicillin susceptible (AmxS), was obtained from the American Type Culture Collection (Manassas, VA, USA). The bacterium was cultured in Columbia agar containing 5% sheep’s blood at 36–37 °C for 3 days under a microaerophilic atmosphere. The antimicrobial activity was determined by a broth microdilution method with brain heart infusion broth supplemented with 10% heat-inactivated fetal bovine serum, as described by Bonacorsi et al. [15]. Briefly, the wells of a 96-well microplate were filled with 100 μL of various concentrations of the phenolic compounds (final concentrations of 64 to 1024 μg/mL). Then, an equal volume of H. pylori suspension (1 × 10 6 cfu/mL) was added to each well. The absorbance was determined in an automatic ELISA microplate reader (Spectra & Rainbow Readers, Tecan) at wavelength of 620 nm. The microplate was incubated at 36–37 °C for 3 days under a microaerophilic atmosphere, after which time the plate was shaken and the absorbance was read again, at the same wavelength. Readings obtained before and after incubation were compared, to determine an increase in bacterial growth. Additionally, under the same conditions, wells without test substances were inoculated with H. pylori, as positive controls, and uninoculated media were used as negative controls. The percentage of growth inhibition was estimated with respect to a control that was incubated only with the solvent (DMSO). Quercetin (Sigma, USA) was used as a phenolic compound reference. All tests were performed in triplicate and repeated at least three times.
Mostrar mais

9 Ler mais

Rev. Bras. Eng. Bioméd.  vol.30 número3

Rev. Bras. Eng. Bioméd. vol.30 número3

The proposed disease descriptor is a set of three attributes in a vector A = {Cor, Idm, 1-Chi} extracted from the SIM matrices of 72 lung images. The dataset of descriptors consists of 27 vector samples of healthy lungs (HL), 24 vector samples of COPD and 21 vector samples of pulmonary ibrosis (PF), comprising left and right sides of CT images. Experts in pulmonary diseases provided the gold standard (GS) reference labels, which are used to training and validate the classiier. A subset of the sample vectors A is used to train a multilayer perceptron (MLP) artiicial neural network (ANN) and the complementary set is used for validation in a holdout procedure. The train-test procedure is repeated 100 rounds and the performance evaluation values are registered using a confusion matrix.
Mostrar mais

8 Ler mais

Preparation of Zoledronate liposome and its impact on apoptosis of Kupffer cells in rat liver

Preparation of Zoledronate liposome and its impact on apoptosis of Kupffer cells in rat liver

Zoledronate (ZOD), a nitro diphosphonate, was the third generation of bisphosphonates, which was more potent and safe to induce osteoclast apoptosis to cure bone tumors in clinics, while the mechanism is the formation of toxic analogues of ATP in osteoclasts (macrophages residing in the bone) after they phagocytize the bisphosphonate bound to hydroxyapatite crystals leads to the intracellular energy metabolism disorder and causes osteoclast apoptosis, thereby reducing osteoclast absorption of bone 3,4 . In addition to
Mostrar mais

9 Ler mais

Snake venom L-amino acid oxidases: an overview on their antitumor effects

Snake venom L-amino acid oxidases: an overview on their antitumor effects

The apoptotic and necrotic effects of BatroxLAAO were analyzed by flow cytometry. This toxin induced cell death processes in different tumor cell lines, such as JURKAT, B16F10, PC12 and HL-60. The B16F10 and PC12 cell lines presented death by apoptosis (AV+), while JURKAT cells displayed death by necrosis (27% necrotic cells) [27]. In HL-60, 50 μg/mL BatroxLAAO showed apoptotic effect in 28.6% and necrotic effect in 14.2% of cells, maintaining a cell viability of approxi- mately 57% [13]. These data corroborate the study by Ande et al. [34], which evaluated the effects of CR- LAAO from Calloselasma rhodostoma venom on the viability of JURKAT leukemia cells and the influence of catalase on apoptosis induction. CR-LAAO induced ne- crosis (PI+) in JURKAT cells in a dose-dependent man- ner. However, in the presence of catalase, the number of necrotic cells was drastically reduced, and a correspond- ing increase in the number of apoptotic cells (AV+) was observed, probably related to the catalase treatment.
Mostrar mais

7 Ler mais

Show all 10000 documents...

temas relacionados