Gomesin, a peptide produced by the spider Acanthoscurria gomesiana, is a potent anticryptococcal agent that acts in synergism with fluconazole

Gomesin is an 18-residue cysteine-rich antimicrobial peptide produced by hemocytes of the spider Acanthoscurria gomesiana. in the present study, the antifungal properties of gomesin against Cryptococcus neoformans, the etiologic agent of cryptococcosis, were evaluated. Gomesin bound to the cell surface of cryptococci, which resulted in cell death associated with membrane permeabilization. Antifungal concentrations of gomesin were not toxic for human brain cells. Supplementation of cryptococcal cultures with the peptide (1 mu M) caused a decrease in capsule expression and rendered fungal cells more susceptible to killing by human brain phagocytes. the possible use of gomesin in combination with fluconazole, a standard antifungal drug, was also evaluated. in association with fluconazole, gomesin concentrations with low antimicrobial activity (0.1-1 mu M) inhibited fungal growth and enhanced the antimicrobial activity of brain phagocytes. These results reveal the potential of gomesin to promote inhibition of cryptococcal growth directly or by enhancing the effectiveness of host defenses.Univ Fed Rio de Janeiro, Inst Microbiol Prof Paulo Goes, Dept Microbiol Geral, Lab Estudos Integrados Bioquim Microbiana, BR-21941590 Rio de Janeiro, BrazilUniv São Paulo, Inst Ciencias Biomed, Dept Parasitol, BR-05508 São Paulo, BrazilUniv Texas, Dept Biol Sci, El Paso, TX 79968 USAUniversidade Federal de São Paulo, Dept Biofis, São Paulo, BrazilUniversidade Federal de São Paulo, Dept Biofis, São Paulo, BrazilWeb of Scienc

Evaluation of α,β-unsaturated ketones as antileishmanial agents

In this study, we assessed the antileishmanial activity of 126 α,β-unsaturated ketones. The compounds NC901, NC884, and NC2459 showed high leishmanicidal activity for both the extracellular (50% effective concentration [EC(50)], 456 nM, 1,122 nM, and 20 nM, respectively) and intracellular (EC(50), 1,870 nM, 937 nM, and 625 nM, respectively) forms of Leishmania major propagated in macrophages, with little or no toxicity to mammalian cells. Bioluminescent imaging of parasite replication showed that all three compounds reduced the parasite burden in the murine model, with no apparent toxicity

Controls on Coral-Ground Development along the Northern Mesoamerican Reef Tract

Coral-grounds are reef communities that colonize rocky substratum but do not form framework or three-dimensional reef structures. To investigate why, we used video transects and underwater photography to determine the composition, structure and status of a coral-ground community located on the edge of a rocky terrace in front of a tourist park, Xcaret, in the northern Mesoamerican Reef tract, Mexico. The community has a relatively low coral, gorgonian and sponge cover (<10%) and high algal cover (>40%). We recorded 23 species of Scleractinia, 14 species of Gorgonacea and 30 species of Porifera. The coral community is diverse but lacks large coral colonies, being dominated instead by small, sediment-tolerant, and brooding species. In these small colonies, the abundance of potentially lethal interactions and partial mortality is high but decreases when colonies are larger than 40 cm. Such characteristics are consistent with an environment control whereby storm waves periodically remove larger colonies and elevate sediment flux. The community only survives these storm conditions due to its slope-break location, which ensures lack of burial and continued local recruitment. A comparison with similar coral-ground communities in adjacent areas suggests that the narrow width of the rock terrace hinders sediment stabilization, thereby ensuring that communities cannot escape bottom effects and develop into three-dimensional reef structures on geological time scales

Kaolinite structural modifications induced by mechanical activation

This study presents novel characterisation techniques to evaluate the effects of mechanical activation (MA) on the kaolinite structure. MA was achieved with a planetary ball mill at various times and rotation speeds to get different activation degrees. A thermal activation was performed for comparison purposes. The results of X-ray diffraction and selective area electron diffraction demonstrated that the kaolinite content was significantly reduced as the amorphous phase increased. Illite, K-feldspars, and quartz impurities were extensively modified as well. The morphology of kaolinite particles is altered. Furthermore, the mechanical treatments significantly affected the hydroxyls, losing bonding strength with the structure, as stated with 1H nuclear magnetic resonance. Thermogravimetric analysis and infrared spectroscopy also revealed that water molecules could be formed due to the reaction of hydroxyls between them or with the atmosphere. This work improves the comprehension of MA on kaolin by clearly confirming with new techniques that the mechanical treatments distort the kaolinite structure

In vitro and in vivo characterization of potent antileishmanial methionine aminopeptidase 1 inhibitors

Leishmania major is the causative agent of cutaneous leishmaniasis (CL). No human vaccine is available for CL, and current drug regimens present several drawbacks, such as emerging resistance, severe toxicity, medium effectiveness, and/or high cost. Thus, the need for better treatment options against CL is a priority. In the present study, we validate the enzyme methionine aminopeptidase 1 of L. major (MetAP1Lm), a metalloprotease that catalyzes the removal of N-terminal methionine from peptides and proteins, as a chemotherapeutic target against CL infection. The in vitro antileishmanial activities of eight novel MetAP1 inhibitors (OJT001 to OJT008) were investigated. Three compounds, OJT006, OJT007, and OJT008, demonstrated potent antiproliferative effects in macrophages infected with L. major amastigotes and promastigotes at submicromolar concentrations, with no cytotoxicity against host cells. Importantly, the leishmanicidal effect in transgenic L. major promastigotes overexpressing MetAP1Lm was diminished by almost 10-fold in comparison to the effect in wild-type promastigotes. Furthermore, the in vivo activities of OJT006, OJT007, and OJT008 were investigated in L. major-infected BALB/c mice. In comparison to the footpad parasite load in the control group, OJT008 decreased the footpad parasite load significantly, by 86%, and exhibited no toxicity in treated mice. We propose MetAP1 inhibitor OJT008 as a potential chemotherapeutic candidate against CL infection caused by L. major infection

Development of Thiophene Compounds as Potent Chemotherapies for the Treatment of Cutaneous Leishmaniasis Caused by Leishmania major

Leishmania major (L. major) is a protozoan parasite that causes cutaneous leishmaniasis. About 12 million people are currently infected with an annual incidence of 1.3 million cases. The purpose of this study was to synthesize a small library of novel thiophene derivatives, and evaluate its parasitic activity, and potential mechanism of action (MOA). We developed a structure–activity relationship (SAR) study of the thiophene molecule 5A. Overall, eight thiophene derivatives of 5A were synthesized and purified by silica gel column chromatography. Of these eight analogs, the molecule 5D showed the highest in vitro activity against Leishmania major promastigotes (EC50 0.09 ± 0.02 µM), with an inhibition of the proliferation of intracellular amastigotes higher than 75% at only 0.63 µM and an excellent selective index. Moreover, the effect of 5D on L. major promastigotes was associated with generation of reactive oxygen species (ROS), and in silico docking studies suggested that 5D may play a role in inhibiting trypanothione reductase. In summary, the combined SAR study and the in vitro evaluation of 5A derivatives allowed the identification of the novel molecule 5D, which exhibited potent in vitro anti-leishmanial activity resulting in ROS production leading to cell death with no significant cytotoxicity towards mammalian cells

A Multi-Omics Analysis Pipeline for the Metabolic Pathway Reconstruction in the Orphan Species Quercus ilex

Holm oak (Quercus ilex) is the most important and representative species of the Mediterranean forest and of the Spanish agrosilvo-pastoral “dehesa” ecosystem. Despite its environmental and economic interest, Holm oak is an orphan species whose biology is very little known, especially at the molecular level. In order to increase the knowledge on the chemical composition and metabolism of this tree species, the employment of a holistic and multi-omics approach, in the Systems Biology direction would be necessary. However, for orphan and recalcitrant plant species, specific analytical and bioinformatics tools have to be developed in order to obtain adequate quality and data-density before to coping with the study of its biology. By using a plant sample consisting of a pool generated by mixing equal amounts of homogenized tissue from acorn embryo, leaves, and roots, protocols for transcriptome (NGS-Illumina), proteome (shotgun LC-MS/MS), and metabolome (GC-MS) studies have been optimized. These analyses resulted in the identification of around 62629 transcripts, 2380 protein species, and 62 metabolites. Data are compared with those reported for model plant species, whose genome has been sequenced and is well annotated, including Arabidopsis, japonica rice, poplar, and eucalyptus. RNA and protein sequencing favored each other, increasing the number and confidence of the proteins identified and correcting erroneous RNA sequences. The integration of the large amount of data reported using bioinformatics tools allows the Holm oak metabolic network to be partially reconstructed: from the 127 metabolic pathways reported in KEGG pathway database, 123 metabolic pathways can be visualized when using the described methodology. They included: carbohydrate and energy metabolism, amino acid metabolism, lipid metabolism, nucleotide metabolism, and biosynthesis of secondary metabolites. The TCA cycle was the pathway most represented with 5 out of 10 metabolites, 6 out of 8 protein enzymes, and 8 out of 8 enzyme transcripts. On the other hand, gaps, missed pathways, included metabolism of terpenoids and polyketides and lipid metabolism. The multi-omics resource generated in this work will set the basis for ongoing and future studies, bringing the Holm oak closer to model species, to obtain a better understanding of the molecular mechanisms underlying phenotypes of interest (productive, tolerant to environmental cues, nutraceutical value) and to select elite genotypes to be used in restoration and reforestation programs, especially in a future climate change scenario

A soft clustering approach to detect socio-ecological landscape boundaries using bayesian networks

Detecting socio-ecological boundaries in traditional rural landscapes is very important for the planning and sustainability of these landscapes. Most of the traditional methods to detect ecological boundaries have two major shortcomings: they are unable to include uncertainty, and they often exclude socio-economic information. This paper presents a new approach, based on unsupervised Bayesian network classifiers, to find spatial clusters and their boundaries in socio-ecological systems. As a case study, a Mediterranean cultural landscape was used. As a result, six socio-ecological sectors, following both longitudinal and altitudinal gradients, were identified. In addition, different socio-ecological boundaries were detected using a probability threshold. Thanks to its probabilistic nature, the proposed method allows experts and stakeholders to distinguish between different levels of uncertainty in landscape management. The inherent complexity and heterogeneity of the natural landscape is easily handled by Bayesian networks. Moreover, variables from different sources and characteristics can be simultaneously included. These features confer an advantage over other traditional techniques

Responses and Differences in Tolerance to Water Shortage under Climatic Dryness Conditions in Seedlings from Quercus spp. and Andalusian Q. ilex Populations

Analyzing differences in tolerance to drought in Quercus spp., and the characterization of these responses at the species and individual population level, are imperative for the selection of resilient elite genotypes in reforestation programs. The main objective of this work was to evaluate differences in the response and tolerance to water shortage under in five Quercus spp. and five Andalusian Q. ilex populations at the inter- and intraspecies level. Six-month-old seedlings grown in perlite were subjected to drought treatments by withholding water for 28 days under mean 37 °C temperature, 28 W m-2 solar irradiance, and 41% humidity. The use of perlite as the substrate enabled the establishment of severe drought stress with reduction in water availability from 73% (field capacity) to 28% (dryness), corresponding to matric potentials of 0 and −30 kPa. Damage symptoms, mortality rate, leaf water content, photosynthetic, and biochemical parameters (amino acids, sugars, phenolics, and pigments) were determined. At the phenotypic level, based on damage symptoms and mortality, Q. ilex behaved as the most drought tolerant species. Drought caused a significant decrease in leaf fluorescence, photosynthesis rate, and stomatal conductance in all Quercus spp. analyzed, being less pronounced in Q. ilex. There were not differences between irrigated and non-irrigated Q. ilex seedlings in the content of sugar and photosynthetic pigments, while the total amino acid and phenolic content significantly increased under drought conditions. As a response to drought, living Q. ilex seedlings adjust stomata opening and gas exchange, and keep hydrated, photosynthetically active, and metabolically competent. At the population level, based on damage symptoms, mortality, and physiological parameters, the eastern Andalusian populations were more tolerant than the western ones. These observations inform the basis for the selection of resilient genotypes to be used in breeding and reforestation programs

Características bromatológicas y fermentativas in vitro de complementos con Enterolobium cyclocarpum (Jacq.) Griseb y cáscara de Cucurbita argyrosperma Huber

Objective: To determine the bromatological and in vitro fermentative characteristics of supplements made with pod parota and pumpkin pulp shell. Methodology: The supplements evaluated were C1 = 50% pumpkin pulp shell and 50% pod parota; C2 = 60% pumpkin pulp shell and 40% pod parota; C3 = 70% pumpkin pulp shell and 30% pod parota. In the supplements, dry matter (DM), crude protein (CP), ash (As), organic matter (OM), neutral detergent fiber (NDF), acid detergent fiber (ADF), partial and accumulated production of biogas and methane were determined, biogas production kinetics, pH, total bacteria count, ammoniacal nitrogen, degradation of DM and NDF Results: On average they quantified 15.88% of CP and 42.36% of NDF. C3 produced 4.53% more accumulated biogas than C2 (P&lt;0.05). In the accumulated production of methane C2 and C3 did not show differences (P&gt;0.05); but, they produced 7.31% less methane than C1 (P&lt;0.05). In vitro degradations did not show differences between treatments (P&gt;0.05). Limitations on study: The best fermentative characteristics appear when the complement is worked with 60% pumpkin pulp shell. Conclusions: Pumpkin pulp shell with pod parota are used to elaborate complements based on in vitro biogas production and degradations, so it can represent an alternative feeding of ruminants in the tropics.Objetivo: Determinar las características bromatológicas y fermentativas in vitro de complementos elaborados con harina de vaina de parota, cascara y pulpa de calabaza. Metodología: Los complementos evaluados fueron C1 = 50% harina de cascara con pulpa de calabaza y 50% de harina de vaina de parota; C2 = 60% harina de cascara con pulpa de calabaza y 40% de harina de vaina de parota; C3 = 70% harina de cascara con pulpa de calabaza y 30% de harina de vaina de parota. En los complementos se determinó materia seca (MS), proteína cruda (PC), cenizas (Ce), materia orgánica (MO), fibra detergente neutro (FDN), fibra detergente ácido (FDA), producción parcial y acumulada de biogás y metano, cinética de producción de biogás, pH, conteo total de bacterias, nitrógeno amoniacal, degradación de MS y FDN. Resultados: En promedio cuantificaron 15.88% de PC y 42.36% de FDN. C3 produjo 4.53% más biogás acumulado que C2 (P&lt;0.05). En la producción acumulada de metano C2 y C3 no mostraron diferencias (P&gt;0.05); pero, produjeron 7.31% menos metano que C1 (P&lt;0.05). Las degradaciones in vitro no presentaron diferencias entre tratamientos (P&gt;0.05). Limitaciones del estudio: Las mejores características fermentativas se presentan cuando el complemento se labora con 60% de harina de cascara con pulpa de calabaza. Conclusiones: La harina de cascara con pulpa de calabaza con vaina de parota sirven para elaborar complementos con base en su producción de biogás y degradaciones in vitro, por lo que puede representar una alternativa de alimentación de rumiantes en el trópico