Extracellular HSP70 Activates ERK1/2, NF-kB and Pro-Inflammatory Gene Transcription Through Binding with RAGE in A549 Human Lung Cancer Cells

BACKGROUND/AIMS

Heat shock protein 70 (HSP70) has been recently described with extracellular actions, where it is actively released in inflammatory conditions. Acting as DAMPs (damage associated molecular pattern), extracellular HSP70 (eHSP70) interacts with membrane receptors and activates inflammatory pathways. At this context, the receptor for advanced glycation endproducts (RAGE) emerges as a possible candidate for interaction with eHSP70. RAGE is a pattern-recognition receptor and its expression is increased in several diseases related to a chronic pro-inflammatory state. One of the main consequences of RAGE ligand-binding is the ERK1/2 (extracellular signal-regulated kinases)-dependent activation of NF-kB (nuclear factor kappa B), which leads to expression of TNF-α (tumor necrosis factor alpha) and other cytokines. The purpose of this work is to elucidate if eHSP70 is able to evoke RAGE-dependent signaling using A549 human lung cancer cells, which constitutively express RAGE.

METHODS

Immunoprecipitation and protein proximity assay were utilized to demonstrate the linkage between RAGE and eHSP70. To investigate RAGE relevance on cell response to eHSP70, siRNA was used to knockdown the receptor expression. Signaling pathways activation were evaluated by western blotting, gene reporter luciferase and real time quantitative PCR.

RESULTS

Protein eHSP70 shown to be interacting physically with the receptor RAGE in our cell model. Treatment with eHSP70 caused ERK1/2 activation and NF-κB transactivation impaired by RAGE knockdown. Moreover, the stimulation of pro-inflammatory cytokines expression by eHSP70 was inhibited in RAGE-silenced cells. Finally, conditioned medium of eHSP70-treated A549 cells caused differential effects in monocytes cytokine expression when A549 RAGE expression is inhibited.

CONCLUSIONS

Our results evidence eHSP70 as a novel RAGE agonist capable of influence the cross-talk between cancer and immune system cells.

The effect of plasma-treated polyethylene fiber on the fracture strength of polymethyl methacrylate

The effect of a plasma-treated polyethylene fiber on the fracture strength of polymethyl methacrylate was evaluated in this study. Sixteen treated and 16 untreated polymethyl methacrylate bars were tested by use of a three-point compression loading apparatus. Under the conditions of this experiment the treated bars showed a mean fracture strength of 12.56 MPa compared with 9.81 MPa for the untreated samples. In addition to the increased fracture strength, the treated bars also demonstrated resistance to crack propagation. The bars remained in one piece, held together throughout the compression loading by the polyethylene fiber. The clinical implication of these findings is a reduced incidence of fixed provisional restoration failure.

Cyanobacterial diversity held in microbial biological resource centers as a biotechnological asset: the case study of the newly established LEGE culture collection

Cyanobacteria are a well-known source of bioproducts which renders culturable strains a valuable resource for biotechnology purposes. We describe here the establishment of a cyanobacterial culture collection (CC) and present the first version of the strain catalog and its online database (http://lege.ciimar.up.pt/). The LEGE CC holds 386 strains, mainly collected in coastal (48%), estuarine (11%), and fresh (34%) water bodies, for the most part from Portugal (84%). By following the most recent taxonomic classification, LEGE CC strains were classified into at least 46 genera from six orders (41% belong to the Synechococcales), several of them are unique among the phylogenetic diversity of the cyanobacteria. For all strains, primary data were obtained and secondary data were surveyed and reviewed, which can be reached through the strain sheets either in the catalog or in the online database. An overview on the notable biodiversity of LEGE CC strains is showcased, including a searchable phylogenetic tree and images for all strains. With this work, 80% of the LEGE CC strains have now their 16S rRNA gene sequences deposited in GenBank. Also, based in primary data, it is demonstrated that several LEGE CC strains are a promising source of extracellular polymeric substances (EPS). Through a review of previously published data, it is exposed that LEGE CC strains have the potential or actual capacity to produce a variety of biotechnologically interesting compounds, including common cyanotoxins or unprecedented bioactive molecules. Phylogenetic diversity of LEGE CC strains does not entirely reflect chemodiversity. Further bioprospecting should, therefore, account for strain specificity of the valuable cyanobacterial holdings of LEGE CC.

Methods to detect cyanobacteria and their toxins in the environment

Cyanobacteria blooms are since early times a cause for environmental concern because of their negative impact through the release of odors, water discoloration, and more dangerously through the release of toxic compounds (i.e. the cyanotoxins) that can affect both human and animal welfare. Surveillance of the aquatic ecosystems is therefore obligatory, and methods to achieve such require a prompt answer not only regarding the species that are producing the blooms but also the cyanotoxins that are being produced and/or released. Moreover, besides this well-known source of possible intoxication, it has been demonstrated the existence of several other potential routes of exposure, either for humans or other biota such as through food additives and in terrestrial environments (in plants, lichens, biological soil crusts) and the recognition of their harmful impact on less studied ecosystems (e.g. coral reefs). Nowadays, the most frequent approaches to detect toxic cyanobacteria and/or their toxins are the chemical-, biochemical-, and molecular-based methods. Above their particular characteristics and possible applications, they all bring to the environmental monitoring several aspects that are needed to be discussed and scrutinized. The end outcome of this review will be to provide newer insights and recommendations regarding the methods needed to apply in an environmental risk assessment program. Therefore, a current state of the knowledge concerning the three methodological approaches will be presented, while highlighting positive and negative aspects of each of those methods within the purpose of monitoring or studying cyanobacteria and their toxins in the environment.

Use of rhBMP-2 Activated Chitosan Films To Improve Osseointegration

Considering the design and development of biomaterials used in tissue engineering, not only is it important that they are biocompatible but also that they induce the desired cellular response for tissue regeneration. Chitosan, a biocompatible and bioresorbable polymer of N-acetylglucosamine and glucosamine is used in our work combined with recombinant human BMP-2 (rhBMP-2), a potentially useful activation factor for bone repair. In this way, we try to combine the biological and filmogenic properties of this biopolymer with the osseoinductive ability of the rhBMP-2. Results showed that the chitosan films employed, without and with rhBMP-2 activation, are able to support cellular growth and proliferation on them and that only the rhBMP-2 activated ones are able to differentiate from a myoblastic mouse cell line (C2C12) toward osteoblastic phenotype. Osseoinduction properties of rhBMP-2 activated films persist for a long storage time. The in vivo experiments performed confirm the expectative created by the in vitro results obtained and are an indication that rhBMP-2 activated chitosan films could be a very attractive biomaterial for the enhancement of osseointegration of surgical prostheses and implants and for the purpose of tissue engineering bone regeneration.

Actinobacteria and Cyanobacteria Diversity in Terrestrial Antarctic Microenvironments Evaluated by Culture-Dependent and Independent Methods

Bacterial diversity from McMurdo Dry Valleys in Antarctica, the coldest desert on earth, has become more easily assessed with the development of High Throughput Sequencing (HTS) techniques. However, some of the diversity remains inaccessible by the power of sequencing. In this study, we combine cultivation and HTS techniques to survey actinobacteria and cyanobacteria diversity along different soil and endolithic micro-environments of Victoria Valley in McMurdo Dry Valleys. Our results demonstrate that the Dry Valleys actinobacteria and cyanobacteria distribution is driven by environmental forces, in particular the effect of water availability and endolithic environments clearly conditioned the distribution of those communities. Data derived from HTS show that the percentage of cyanobacteria decreases from about 20% in the sample closest to the water source to negligible values on the last three samples of the transect with less water availability. Inversely, actinobacteria relative abundance increases from about 20% in wet soils to over 50% in the driest samples. Over 30% of the total HTS data set was composed of actinobacterial strains, mainly distributed by 5 families: Sporichthyaceae, Euzebyaceae, Patulibacteraceae, Nocardioidaceae, and Rubrobacteraceae. However, the 11 actinobacterial strains isolated in this study, belonged to Micrococcaceae and Dermacoccaceae families that were underrepresented in the HTS data set. A total of 10 cyanobacterial strains from the order Synechococcales were also isolated, distributed by 4 different genera (Nodosilinea, Leptolyngbya, Pectolyngbya, and Acaryochloris-like). In agreement with the cultivation results, Leptolyngbya was identified as dominant genus in the HTS data set. Acaryochloris-like cyanobacteria were found exclusively in the endolithic sample and represented 44% of the total 16S rRNA sequences, although despite our efforts we were not able to properly isolate any strain from this Acaryochloris-related group. The importance of combining cultivation and sequencing techniques is highlighted, as we have shown that culture-dependent methods employed in this study were able to retrieve actinobacteria and cyanobacteria taxa that were not detected in HTS data set, suggesting that the combination of both strategies can be usefull to recover both abundant and rare members of the communities.

Antitumor activity of hierridin B, a cyanobacterial secondary metabolite found in both filamentous and unicellular marine strains

Cyanobacteria are widely recognized as a valuable source of bioactive metabolites. The majority of such compounds have been isolated from so-called complex cyanobacteria, such as filamentous or colonial forms, which usually display a larger number of biosynthetic gene clusters in their genomes, when compared to free-living unicellular forms. Nevertheless, picocyanobacteria are also known to have potential to produce bioactive natural products. Here, we report the isolation of hierridin B from the marine picocyanobacterium Cyanobium sp. LEGE 06113. This compound had previously been isolated from the filamentous epiphytic cyanobacterium Phormidium ectocarpi SAG 60.90, and had been shown to possess antiplasmodial activity. A phylogenetic analysis of the 16S rRNA gene from both strains confirmed that these cyanobacteria derive from different evolutionary lineages. We further investigated the biological activity of hierridin B, and tested its cytotoxicity towards a panel of human cancer cell lines; it showed selective cytotoxicity towards HT-29 colon adenocarcinoma cells.

Complete dentures for a child with hypohidrotic ectodermal dysplasia: a clinical report

Young children with anodontia caused by hypohidrotic ectodermal dysplasia not only have difficulties in eating and speaking but can also sense that their appearance is different than others. Enabling children with HED to look and act more like their peers through the use of well-fitting and functioning dentures with age-appropriate denture teeth will greatly assist in their transitioning into the school years. Although denture fabrication requires multiple patient appointments and good cooperation, it is shown that even young children can cooperate for the denture-making process. The desire to be like others who have teeth can be a motivator for cooperation in even the young child. Children should be given every opportunity to develop to their fullest potential. The dentist can make a significant contribution to the overall development and well being of a child with HED.

Culture-dependent characterization of cyanobacterial diversity in the intertidal zones of the Portuguese coast: a polyphasic study

Cyanobacteria are important primary producers, and many are able to fix atmospheric nitrogen playing a key role in the marine environment. However, not much is known about the diversity of cyanobacteria in Portuguese marine waters. This paper describes the diversity of 60 strains isolated from benthic habitats in 9 sites (intertidal zones) on the Portuguese South and West coasts. The strains were characterized by a morphological study (light and electron microscopy) and by a molecular characterization (partial 16S rRNA, nifH, nifK, mcyA, mcyE/ndaF, sxtI genes). The morphological analyses revealed 35 morphotypes (15 genera and 16 species) belonging to 4 cyanobacterial Orders/Subsections. The dominant groups among the isolates were the Oscillatoriales. There is a broad congruence between morphological and molecular assignments. The 16S rRNA gene sequences of 9 strains have less than 97% similarity compared to the sequences in the databases, revealing novel cyanobacterial diversity. Phylogenetic analysis, based on partial 16S rRNA gene sequences showed at least 12 clusters. One-third of the isolates are potential N(2)-fixers, as they exhibit heterocysts or the presence of nif genes was demonstrated by PCR. Additionally, no conventional freshwater toxins genes were detected by PCR screening.

Factors predicting a hospital stay of over 3 days in patients with acute exacerbation of chronic obstructive pulmonary disease

OBJECTIVE

To investigate the factors predicting a hospital stay of over 3 days in patients who required hospitalization for acute exacerbation of chronic obstructive pulmonary disease (COPD).

DESIGN AND SETTING

A cross-sectional study was done at a tertiary hospital serving an area of 500 000 inhabitants.

SUBJECTS

A total of 273 patients (alpha=0.05; accuracy=5.94%) who had been admitted consecutively to the Short Stay Medical Unit at the Juan Canalejo Hospital in A Coruña, from February 1998 to March 1999, with a diagnosis focusing on exacerbation of COPD. Methods. Demographic variables, past medical history, symptoms, arterial blood gases, functional tests, treatment and the cause of exacerbation were studied in each patient. The hospital stay was dichotomized into <or=3 vs. >3 days. The prognostic factors of a hospital stay were determined by log regression. Results. The mean stay was 4.6 +/- 5.1 days (range: 1-64). After monitoring the associated covariables, the following were found to have an independent effect on the prediction of a hospital stay of over 3 days: weekend admissions (OR=4.17; 95% CI: 2.42-7.18), the presence of cor pulmonale (OR=2.19; 95% CI: 1.27-3.78), and the respiratory rate on admission (OR=1.09; 95% CI: 1.03-1.14). Arterial blood gases and functional tests showed no independent effect. Conclusions. The factors having an independent prognostic value in determining the length of hospital stays in patients with COPD are weekend admission, cor pulmonale and respiratory rate. Additional studies are required to validate these findings.

Oxidation-resistant silver nanostructures for ultrastable plasmonic applications

Reduced degradation (oxidation) of silver nanoparticles (NPs) is achieved by contacting Ag with immiscible Co NPs. The relative decay of the plasmon peak (plot) shows that pure Ag NPs (blue dashed curve) decay by 25% in ca 20 days, whereas AgCo NPs last about 10 times longer, requiring nearly five months for a similar decay (red solid curve). The TEM images for both Ag and AgCo were taken after 50 days of storage under ambient conditions.

Increased glycolysis is an early consequence of palmitate lipotoxicity mediated by redox signaling

Exposure to toxic levels of fatty acids (lipotoxicity) leads to cell damage and death and is involved in the pathogenesis of the metabolic syndrome. Since the metabolic consequences of lipotoxicity are still poorly understood, we studied the bioenergetic effects of the saturated fatty acid palmitate, quantifying changes in mitochondrial morphology, real-time oxygen consumption, ATP production sources, and extracellular acidification in hepatoma cells. Surprisingly, glycolysis was enhanced by the presence of palmitate as soon as 1 h after stimulus, while oxygen consumption and oxidative phosphorylation were unchanged, despite overt mitochondrial fragmentation. Palmitate only induced mitochondrial fragmentation if glucose and glutamine were available, while glycolytic enhancement did not require glutamine, showing it is independent of mitochondrial morphological changes. Redox state was altered by palmitate, as indicated by NAD(P)H quantification. Furthermore, the mitochondrial antioxidant mitoquinone, or a selective inhibitor of complex I electron leakage (S1QEL) further enhanced palmitate-induced glycolysis. Our results demonstrate that palmitate overload and lipotoxicity involves an unexpected and early increase in glycolytic flux, while, surprisingly, no changes in oxidative phosphorylation are observed. Interestingly, enhanced glycolysis involves signaling by mitochondrially-generated oxidants, uncovering a novel regulatory mechanism for this pathway.

Cyanobacterium Microcystis aeruginosa response to pentachlorophenol and comparison with that of the microalga Chlorella vulgaris

Pentachlorophenol (PCP) effects on a strain of the cyanobacterium Microcystis aeruginosa were investigated at laboratory scale. This is the first systematic ecotoxicity study of the effects of PCP on an aquatic cyanobacterium. The microalga Chlorella vulgaris was studied in the same conditions as the cyanobacterium, in order to compare the PCP toxicity and its removal by the species. The cells were exposed to environmental levels of PCP during 10 days, in Fraquil culture medium, at nominal concentrations from 0.01 to 1000 μg L(-1), to the cyanobacterium, and 0.01 to 5000 μg L(-1), to the microalga. Growth was assessed by area under growth curve (AUC, optical density vs time) and chlorophyll a content (chla). The toxicity profiles of the two species were very different. The calculated effective concentrations EC20 and EC50 were much lower to M. aeruginosa, and its growth inhibition expressed by chla was concentration-dependent while by AUC was not concentration-dependent. The cells might continue to divide even with lower levels of chla. The number of C. vulgaris cells decreased with the PCP concentration without major impact on the chla. The effect of PCP on M. aeruginosa is hormetic: every concentration studied was toxic except 1 μg L(-1), which promoted its growth. The legal limit of PCP set by the European Union for surface waters (1 μg L(-1)) should be reconsidered since a toxic cyanobacteria bloom might occur. The study of the removal of PCP from the culture medium by the two species is an additional novelty of this work. M. aeruginosa could remove part of the PCP from the medium, at concentrations where toxic effects were observed, while C. vulgaris stabilized it.

Detection of anatoxin-a and three analogs in Anabaena spp. cultures: new fluorescence polarization assay and toxin profile by LC-MS/MS

Anatoxin-a (ATX) is a potent neurotoxin produced by several species of Anabaena spp. Cyanobacteria blooms around the world have been increasing in recent years; therefore, it is urgent to develop sensitive techniques that unequivocally confirm the presence of these toxins in fresh water and cyanobacterial samples. In addition, the identification of different ATX analogues is essential to later determine its toxicity. In this paper we designed a fluorescent polarization (FP) method to detect ATXs in water samples. A nicotinic acetylcholine receptor (nAChR) labeled with a fluorescein derivative was used to develop this assay. Data showed a direct relationship between the amount of toxin in a sample and the changes in the polarization degree of the emitted light by the labeled nAChR, indicating an interaction between the two molecules. This method was used to measure the amount of ATX in three Anabaena spp. cultures. Results indicate that it is a good method to show ATXs presence in algal samples. In order to check the toxin profile of Anabaena cultures a LC-MS/MS method was also developed. Within this new method, ATX-a, retention time (RT) 5 min, and three other molecules with a mass m/z 180.1 eluting at 4.14 min, 5.90 min and 7.14 min with MS/MS spectra characteristic of ATX toxin group not previously identified were detected in the Anabaena spp. cultures. These ATX analogues may have an important role in the toxicity of the sample.

Self-organized bimetallic Ag-Co nanoparticles with tunable localized surface plasmons showing high environmental stability and sensitivity

We demonstrate a promising synthesis route based on pulsed laser dewetting of bilayer films (Ag and Co) to make bimetallic nanoparticle arrays. By combining experiment and theory we establish a parameter space for the independent control of composition and diameter for the bimetallic nanoparticles. As a result, physical properties, such as the localized surface plasmon resonance (LSPR), that depend on particle size and composition can be readily tuned over a wavelength range one order of magnitude greater than for pure Ag nanoparticles. The LSPR detection sensitivity of the bimetallic nanoparticles with narrow size distribution was found to be high-comparable with pure Ag (∼60 nm/RIU). Moreover, they showed significantly higher long-term environmental stability over pure Ag.

Phylogenetic, chemical and morphological diversity of cyanobacteria from Portuguese temperate estuaries

Cyanobacteria from estuarine habitats have been poorly studied regarding diversity and potential bioactive compounds production compared with their fresh and marine waters' congeners. In this work, 44 cyanobacteria isolates characterised from three Portuguese estuarine environments. Identification was performed based on diacritical morphological features of the isolates (e.g. cell shape, cell size, presence/absence of sheaths) and on 16S rRNA gene sequences phylogenetic analysis. Diversity of produced secondary metabolites was assessed by molecular and analytical tools. The isolates (mostly benthic forms) belonged to: (i) Chroococcales (Cyanobium, Synechocystis and Synechococcus), (ii) Oscillatoriales (Leptolyngbya, Microcoleus, Phormidium and Romeria) and (iii) Nostocales (Nostoc and Nodularia). 19 morphotypes were assigned at the species level, while phylogeny allowed us to distinguish 21 phylotypes spread amongst three distinct large clades. McyA and sxtI gene fragments were detected in some isolates, despite absence of toxins. Simultaneous presence of anabaenopeptins A and D was for the first time identified in Nostoc (LEGE06077). No correlation between morphological/phylogenetic relationships and the secondary-metabolite profile of the isolates was found. This is the first comprehensive study of estuarine cyanobacteria of Portuguese habitats revealing a diverse array of cyanobacteria that constitute an important source of potential bioactive compounds with ecological relevance and/or biomedical application.

Frequency of myocarditis in cases of fatal meningococcal infection in children: observations on 31 cases studied at autopsy

The frequency of myocarditis associated with meningococcal disease in children was reported only in two autopsied series (United States and South Africa). Here we report the frequency of associated myocarditis in 31 children who died of meningococcal infection at Hospital Infantile N.S. da Glória in Vitória, Espirito Santo State, Brazil. The diagnosis was confirmed by isolation of Neisseria meningitidis. At least three sections of fragments of both atria and ventricles were studied using the Dallas Criteria for the morphologic diagnosis of myocarditis. The mean age was 47.6 +/- 39.8 months and the mean survival time after the onset of symptoms was 46.1 +/- 26.5 h (12-112 h). Myocarditis was present in 13 (41.9%) patients, being of minimal severity in 11 cases and of moderate severity in 2 cases. There were no cases with severe diffuse myocarditis. The frequency of myocarditis was not influenced by sex, presence of meningitis, survival time after the onset of symptoms or use of vasoactive drugs. The frequency of myocarditis reported here was intermediate between the values reported in the only two case series published in the literature (57% in the United States and 27% in South Africa). Although our data confirm the high frequency of myocarditis in meningococcal disease, further investigations are necessary to elucidate the contribution of myocarditis to myocardial dysfunction observed in cases of meningococcal infection in children.

Inhibition of Bacterial and Fungal Biofilm Formation by 675 Extracts from Microalgae and Cyanobacteria

Bacterial biofilms are complex biological systems that are difficult to eradicate at a medical, industrial, or environmental level. Biofilms confer bacteria protection against external factors and antimicrobial treatments. Taking into account that about 80% of human infections are caused by bacterial biofilms, the eradication of these structures is a great priority. Biofilms are resistant to old-generation antibiotics, which has led to the search for new antimicrobials from different sources, including deep oceans/seas. In this study, 675 extracts obtained from 225 cyanobacteria and microalgae species (11 phyla and 6 samples belonging to unknown group) were obtained from different culture collections: The Blue Biotechnology and Ecotoxicology Culture Collection (LEGE-CC), the Coimbra Collection of Algae (ACOI) from Portugal, and the Roscoff Culture Collection (RCC) from France. The largest number of samples was made up of the microalgae phylum Chlorophyta (270) followed by Cyanobacteria (261). To obtain a large range of new bioactive compounds, a method involving three consecutive extractions (hexane, ethyl acetate, and methanol) was used. The antibiofilm activity of extracts was determined against seven different bacterial species and two Candida strains in terms of minimal biofilm inhibitory concentration (MBIC). The highest biofilm inhibition rates (%) were achieved against Candida albicans and Enterobacter cloacae. Charophyta, Chlorophyta, and Cyanobacteria were the most effective against all microorganisms. In particular, extracts of Cercozoa phylum presented the lowest MBIC₅₀ and MBIC₉₀ values for all the strains except C. albicans.

A lumbar chordoma treated with a wide resection

Chordomas are rare skeletal tumors arising from the embryonic remains of the notochord [18, 30]. These tumors tend to appear in midline regions, particularly at the upper and lower extremities of the spinal column. We report the case of a 74-year-old woman with radicular compression associated with an L3 chordoma that was treated with a wide resection.

Simultaneous death of twins. An environmental hazard or SIDS?

The sudden and simultaneous death of twin infants is described. The search for hazards in the home and the postmortem investigation provided an insight into the possible mechanism of death. Instead of a diagnosis of simultaneous sudden infant death syndrome (SIDS), the infants were determined to be victims of a combination of several environmental factors that led suddenly to death. Strong circumstancial evidence of nonnatural (accidental) death included sublethal levels of carbon monoxide (CO), overwrapping, and mechanical obstruction of upper airways. The literature concerning the phenomenon of simultaneous twin death is also reviewed.

Autophagy in Hepatic Steatosis: A Structured Review

Steatosis is the accumulation of neutral lipids in the cytoplasm. In the liver, it is associated with overeating and a sedentary lifestyle, but may also be a result of xenobiotic toxicity and genetics. Non-alcoholic fatty liver disease (NAFLD) defines an array of liver conditions varying from simple steatosis to inflammation and fibrosis. Over the last years, autophagic processes have been shown to be directly associated with the development and progression of these conditions. However, the precise role of autophagy in steatosis development is still unclear. Specifically, autophagy is necessary for the regulation of basic metabolism in hepatocytes, such as glycogenolysis and gluconeogenesis, response to insulin and glucagon signaling, and cellular responses to free amino acid contents. Also, genetic knockout models for autophagy-related proteins suggest a critical relationship between autophagy and hepatic lipid metabolism, but some results are still ambiguous. While autophagy may seem necessary to support lipid oxidation in some contexts, other evidence suggests that autophagic activity can lead to lipid accumulation instead. This structured literature review aims to critically discuss, compare, and organize results over the last 10 years regarding rodent steatosis models that measured several autophagy markers, with genetic and pharmacological interventions that may help elucidate the molecular mechanisms involved.

Chemoecological screening reveals high bioactivity in diverse culturable Portuguese marine cyanobacteria

Marine cyanobacteria, notably those from tropical regions, are a rich source of bioactive secondary metabolites. Tropical marine cyanobacteria often grow to high densities in the environment, allowing direct isolation of many secondary metabolites from field-collected material. However, in temperate environments culturing is usually required to produce enough biomass for investigations of their chemical constituents. In this work, we cultured a selection of novel and diverse cyanobacteria isolated from the Portuguese coast, and tested their organic extracts in a series of ecologically-relevant bioassays. The majority of the extracts showed activity in at least one of the bioassays, all of which were run in very small scale. Phylogenetically related isolates exhibited different activity profiles, highlighting the value of microdiversity for bioprospection studies. Furthermore, LC-MS analyses of selected active extracts suggested the presence of previously unidentified secondary metabolites. Overall, the screening strategy employed here, in which previously untapped cyanobacterial diversity was combined with multiple bioassays, proved to be a successful strategy and allowed the selection of several strains for further investigations based on their bioactivity profiles.

Microbial community changes elicited by exposure to cyanobacterial allelochemicals

An increasing body of evidence points out that allelopathy may be an important process shaping microbial communities in aquatic ecosystems. Cyanobacteria have well-documented allelopathic properties, mainly derived from the evaluation of the activity of allelopathic extracts or pure compounds towards monocultures of selected target microorganisms. Consequently, little is known regarding the community dynamics of microorganisms associated with allelopathic interactions. In this laboratory-based study, a Microcystis spp.-dominated microbial community from a freshwater lake was exposed, for 15 days, to exudates from the cyanobacterium Oscillatoria sp. strain LEGE 05292 in laboratory conditions. This cyanobacterium is known to produce the allelochemicals portoamides, which were among the exuded compounds. The community composition was followed (by means of polymerase chain reaction followed by denaturing gradient gel electrophoresis and microscopic analyses) and compared to that of a non-exposed situation. Following exposure, clear differences in the community structure were observed, in particular for cyanobacteria and unicellular eukaryotic taxa. Interestingly, distinct Microcystis genotypes present in the community were differentially impacted by the exposure, highlighting the fine-scale dynamics elicited by the exudates. These results support a role for cyanobacterial allelochemicals in the structuring of aquatic microbial communities.

Acute Consumption of Bordo Grape Juice and Wine Improves Serum Antioxidant Status in Healthy Individuals and Inhibits Reactive Oxygen Species Production in Human Neuron-Like Cells

Few studies investigated the biological effects of American grape cultivars. We investigated the metabolic response after acute consumption of grape juice or wine from Bordo grapes (Vitis labrusca) in a placebo-controlled crossover study with fifteen healthy volunteers. Blood samples were collected 1 hour after the intake of 100 mL of water, juice, or wine to measure TBARS, ABTS, FRAP, glucose, and uric acid levels. To evaluate differences in cellular response, intracellular reactive species production (DCFH-DA) and metabolic mitochondrial viability (MTT) were assessed after exposure of human neuron-like cells (SH-SY5Y) to juice or wine. Glycemia was reduced after juice or wine consumption, whereas blood levels of uric acid were reduced after juice consumption but increased after wine consumption. Juice and wine consumption reduced plasma lipid peroxidation and increased plasma antioxidant capacity (ABTS and FRAP assays). Furthermore, juice inhibited H2O2-induced intracellular production of reactive species (RS) and increased the viability of SH-SY5Y cells. In contrast, wine (dealcoholized) exhibited a per se effect by inducing the production of RS and reducing cell viability. These results indicate a positive impact of acute consumption of Bordo juice and wine on human oxidative status, whereas only juice had protective effects against oxidative stress-induced cytotoxicity.