789 research outputs found
Salinity dependence of the distribution of multicellular magnetotactic prokaryotes in a hypersaline lagoon
Candidatus Magnetoglobus multicellularis is an unusual magnetotactic multicellular microorganism composed of a highly organized assemblage of gram-negative bacterial cells. In this work, the salinity dependence of Ca. M. multicellularis and its abundance in the hypersaline Araruama Lagoon, Brazil were studied. Viability experiments showed that Ca. M. multicellularis died in salinities >55â° and < 40â°. Low salinities were also observed to modify the cellular assemblage. In microcosms prepared with different salinities, the microorganism grew better at intermediate salinities whereas in high or low salinities, the size of the population did not increase over time. The concentrations of Ca. M. multicellularis in the lagoon were related to salinity; sites with lower and higher salinities than the lagoon average contained less Ca. M. multicellularis. These results demonstrate the influence of salinity on the survival and distribution of Ca. M. multicellularis in the environment. In sediments, the abundance of Ca. M. multicellularis ranged from 0 to 103 microorganisms/ml, which represented 0.001% of the counts of total bacteria. The ability of Ca. M. multicellularis to accumulate iron and sulfur in high numbers of magnetosomes (up to 905 per microorganism) suggests that its impact on the sequestration of these elements (0.1% for biogenic bacterial iron) is not proportional to its abundance in the lagoon. [Int Microbiol 2009; 12(3):193-201
Biochemical pathways triggered by antipsychotics in human oligodendrocytes: potential of discovering new treatment targets
Schizophrenia is a psychiatric disorder that affects more than 21 million people worldwide. It is an incurable disorder and the primary means of managing symptoms is through administration of pharmacological treatments, which consist heavily of antipsychotics. First-generation antipsychotics have the properties of D-2 receptor antagonists. Second-generation antipsychotics are antagonists of both D-2 and 5HT(2) receptors. Recently, there has been increasing interest in the effects of antipsychotics beyond their neuronal targets and oligodendrocytes are one of the main candidates. Thus, our aim was to evaluate the molecular effects of typical and atypical drugs across the proteome of the human oligodendrocyte cell line, MO3.13. For this, we performed a mass spectrometry-based, bottom-up shotgun proteomic analysis to identify differences triggered by typical (chlorpromazine and haloperidol) and atypical (quetiapine and risperidone) antipsychotics. Proteins which showed changes in their expression levels were analyzed in silico using Ingenuity (R) Pathway Analysis, which implicated dysregulation of canonical pathways for each treatment. Our results shed light on the biochemical pathways involved in the mechanisms of action of these drugs, which may guide the identification of novel biomarkers and the development of new and improved treatments10CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTĂFICO E TECNOLĂGICO - CNPQFUNDAĂĂO DE AMPARO Ă PESQUISA DO ESTADO DE SĂO PAULO - FAPESP460289/2014-42015/23049-0; 2017/18242-1; 2014/14881-1; 2014/10068-4; 2017/25588-1; 2018/03673-1CB-T, VdA, JC, and DM-d-S were supported by FAPESP (SĂŁo Paulo Research Foundation), grants 2015/23049-0, 2017/18242-1, 2014/14881-1, 2014/10068-4, 2017/25588-1, and 2018/03673-1. DM-d-S was also supported by The Brazilian National Council for Scientific and Technological Development (CNPq), grant 460289/2014-4 and Serrapilheira Institute, grant number Serra-1709-1634
Effect of MK-801 and clozapine on the proteome of cultured human oligodendrocytes
Separate lines of evidence have demonstrated the involvement of N-methyl-D-aspartate (NMDA) receptor and oligodendrocyte dysfunctions in schizophrenia. Here, we have carried out shotgun mass spectrometry proteome analysis of oligodendrocytes treated with the NMDA receptor antagonist MK-801 to gain potential insights into these effects at the molecular level. The MK-801 treatment led to alterations in the levels of 68 proteins, which are associated with seven distinct biological processes. Most of these proteins are involved in energy metabolism and many have been found to be dysregulated in previous proteomic studies of post-mortem brain tissues from schizophrenia patients. Finally, addition of the antipsychotic clozapine to MK-801-treated oligodendrocyte cultures resulted in changes in the levels of 45 proteins and treatment with clozapine alone altered 122 proteins and many of these showed opposite changes to the MK-801 effects. Therefore, these proteins and the associated energy metabolism pathways should be explored as potential biomarkers of antipsychotic efficacy. In conclusion, MK-801 treatment of oligodendrocytes may provide a useful model for testing the efficacy of novel treatment approaches10CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTĂFICO E TECNOLĂGICO - CNPQFUNDAĂĂO DE AMPARO Ă PESQUISA DO ESTADO DE SĂO PAULO - FAPESP460289/2014-413/08711-3; 14/21035-0; 14/14881-1; 14/10068-
Spatiotemporal distribution of the magnetotactic multicellular prokaryote Candidatus Magnetoglobus multicellularis in a Brazilian hypersaline lagoon and in microcosms
Candidatus Magnetoglobus multicellularis is an unusual morphotype of magnetotactic prokaryotes. These microorganisms are composed of a spherical assemblage of gram-negative prokaryotic cells capable of swimming as a unitaligned along a magnetic field. While they occur in many aquatic habitats around the world, high numbers of Ca. M. multicellularishave been detected in Araruama Lagoon, a large hypersaline lagoon near the city of Rio de Janeiro, in Brazil. Here,we report on the spatiotemporal distribution of one such population in sediments of Araruama Lagoon, including its annualdistribution and its abundance compared with the total bacterial community. In microcosm experiments, Ca. M. multicellulariswas unable to survive for more than 45 days: the population density gradually decreased coinciding with a shift to theupper layers of the sediment. Nonetheless, Ca. M. multicellularis was detected throughout the year in all sites studied. Changes in the population density seemed to be related to the input of organic matter as well as to salinity. The populationdensity of Ca. M. multicellularis did not correlate with the total bacterial counts; instead, changes in the microbial communitystructure altered their counts in the environment. [Int Microbiol 2012; 15(3):141-149
Biochemical Pathways Triggered by Antipsychotics in Human Oligodendrocytes: Potential of Discovering New Treatment Targets
Schizophrenia is a psychiatric disorder that affects more than 21 million people worldwide. It is an incurable disorder and the primary means of managing symptoms is through administration of pharmacological treatments, which consist heavily of antipsychotics. First-generation antipsychotics have the properties of D2 receptor antagonists. Second-generation antipsychotics are antagonists of both D2 and 5HT2 receptors. Recently, there has been increasing interest in the effects of antipsychotics beyond their neuronal targets and oligodendrocytes are one of the main candidates. Thus, our aim was to evaluate the molecular effects of typical and atypical drugs across the proteome of the human oligodendrocyte cell line, MO3.13. For this, we performed a mass spectrometry-based, bottom-up shotgun proteomic analysis to identify differences triggered by typical (chlorpromazine and haloperidol) and atypical (quetiapine and risperidone) antipsychotics. Proteins which showed changes in their expression levels were analyzed in silico using IngenuityÂź Pathway Analysis, which implicated dysregulation of canonical pathways for each treatment. Our results shed light on the biochemical pathways involved in the mechanisms of action of these drugs, which may guide the identification of novel biomarkers and the development of new and improved treatments
The four hexamerin genes in the honey bee: structure, molecular evolution and function deduced from expression patterns in queens, workers and drones
Background: Hexamerins are hemocyanin-derived proteins that have lost the ability to bind copper ions and transport oxygen; instead, they became storage proteins. The current study aimed to broaden our knowledge on the hexamerin genes found in the honey bee genome by exploring their structural characteristics, expression profiles, evolution, and functions in the life cycle of workers, drones and queens. Results: The hexamerin genes of the honey bee (hex 70a, hex 70b, hex 70c and hex 110) diverge considerably in structure, so that the overall amino acid identity shared among their deduced protein subunits varies from 30 to 42%. Bioinformatics search for motifs in the respective upstream control regions (UCRs) revealed six overrepresented motifs including a potential binding site for Ultraspiracle (Usp), a target of juvenile hormone (JH). The expression of these genes was induced by topical application of JH on worker larvae. The four genes are highly transcribed by the larval fat body, although with significant differences in transcript levels, but only hex 110 and hex 70a are re-induced in the adult fat body in a caste-and sex-specific fashion, workers showing the highest expression. Transcripts for hex 110, hex 70a and hex70b were detected in developing ovaries and testes, and hex 110 was highly transcribed in the ovaries of egg-laying queens. A phylogenetic analysis revealed that HEX 110 is located at the most basal position among the holometabola hexamerins, and like HEX 70a and HEX 70c, it shares potential orthology relationship with hexamerins from other hymenopteran species. Conclusions: Striking differences were found in the structure and developmental expression of the four hexamerin genes in the honey bee. The presence of a potential binding site for Usp in the respective 5' UCRs, and the results of experiments on JH level manipulation in vivo support the hypothesis of regulation by JH. Transcript levels and patterns in the fat body and gonads suggest that, in addition to their primary role in supplying amino acids for metamorphosis, hexamerins serve as storage proteins for gonad development, egg production, and to support foraging activity. A phylogenetic analysis including the four deduced hexamerins and related proteins revealed a complex pattern of evolution, with independent radiation in insect orders.Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP)[05/03926-5; 08/00541-3
Human leukemia cells (HL-60) proteomic and biological signatures underpinning cryo-damage are differentially modulated by novel cryo-additives
Cryopreservation is a routinely used methodology for prolonged storage of viable cells. The use of cryo-protective agents (CPAs) such as dimethylsulfoxide (DMSO), glycerol, or trehalose is paramount to reducing cellular cryo-injury, but their effectiveness is still limited. The current study focuses on establishing and modulating the proteomic and the corresponding biological profiles associated with the cryo-injury of human leukemia (HL-60) cells cryopreserved in DMSO alone or DMSO +/-novel CPAs (e. g., nigerose [Nig] or salidroside [Sal]). Findings: To reduce cryo-damage, HL-60 cells were cultured prior and post cryopreservation in malondialdehyde Roswell Park Memorial Institute medium-1640 media +/- Nig or Sal. Shotgun proteomic analysis showed significant alterations in the levels of proteins in cells cryopreserved in Nig or Sal compared to DMSO. Nig mostly affected cellular metabolism and energy pathways, whereas Sal increased the levels of proteins associated with DNA repair/duplication, RNA transcription, and cell proliferation. Validation testing showed that the proteome profile associated with Sal was correlated with a 2.8-fold increase in cell proliferative rate. At the functional level, both Nig and Sal increased glutathione reductase (0.0012 +/- 6.19E-05 and 0.0016 +/- 3.04E-05 mU/mL, respectively) compared to DMSO controls (0.0003 +/- 3.7E-05 mU/mL) and reduced cytotoxicity by decreasing lactate dehydrogenase activities (from -2.5 to -4.75 fold) and lipid oxidation (-1.6 fold). In contrast, only Nig attenuated protein carbonylation or oxidation. Conclusions: We have identified key molecules and corresponding functional pathways underpinning the effect of cryopreservation (+/- CPAs) of HL-60 cells. We also validated the proteomic findings by identifying the corresponding biological profiles associated with promoting an anti-oxidative environment post cryopreservation. Nig or Sal in comparison to DMSO showed differential or additive effects in regard to reducing cryo-injury and enhancing cell survival/proliferation post thaw. These results can provide useful insight to cryo-damage and the design of enhanced cryomedia formulation83CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTĂFICO E TECNOLĂGICO - CNPQFUNDAĂĂO DE AMPARO Ă PESQUISA DO ESTADO DE SĂO PAULO - FAPESP460 289/2014â42014/14 881â1; 2013/0 8711â3; 2014/10 068â4This work was supported by the King Abdul Aziz City for Science and Technology research fund. J.S.C. and D.,M.S. are funded by FAPESP (SĂŁo Paulo Research Foundation, grants 2014/14 881â1, 2013/0 8711â3, and 2014/10 068â4) and CNPq (the Brazilian National Council for Scientific and Technological Development, grant 460 289/2014â4
CEBs stabilised with geopolymeric binders: mechanical performance of dry-stack masonry
The sustainability in the building industry is currently a sounding topic, seeking the development of more environmental friendly building materials. The incorporation of industrial wastes and the reuse of construction and demolition waste (CDW) in the production of building materials are methods being used to solve this problem. Furthermore, these methods contribute to fulfilling the targets defined by European Union for the valorisation of non-hazard waste. The construction with compressed earth blocks (CEBs) stabilised with geopolymeric binders is a solution that can contribute to this objective by incorporating both CDW (excavation soil) and industrial wastes. Despite some recent research done on this topic, it still deserves further investigation. This paper intends to contribute to the development of this topic by presenting an experimental program, continuing previous research. The experimental program is addressed to the mechanical characterisation of a dry-stack CEB (stabilised with geopolymer obtained from alkaline activation of fly ash) masonry system, and includes the evolution of the strength of the CEBs with the curing time. In general, the evolution of the strength of the CEBs cured under ambient condition was shown to be a slow process, which can have implications on the production process.Portuguese Science and Technology Foundation (FCT) through the project FCOMP-01-0124-FEDER-028864 (FCT-PTDC/ECM-EST/2396/2012)
Children's exposure to indoor air in schools: Impact on wheezing
Wheezing is a common symptom in childhood and has been associated with air pollution. Children spend a large part of their time in school, this being the most important indoor environment apart from home. However, studies on the impact of children's indoor air pollution exposure at schools on respiratory health are scarce. Thus, this study aimed to assess the impact of children's exposure to indoor air pollution in a total of five urban nursery and primary schools on active wheezing. Multivariate logistic regression models were used to estimate the associations, adjusted for sex, age group (pre-school/primary school) and parental history of asthma. A microenvironmental modelling approach was used to estimate indoor air pollution exposure to each of the pollutants exceeding legislation limit values (CO2, formaldehyde and PM2.5), as the sum of the product of time spent by the child in different indoor school microenvironments and the time-averaged concentration measured in each microenvironment. Measurements were performed in 11 classrooms, two bedrooms and two canteens in Porto, Portugal. A total of 164 completed parent-reported questionnaires derived from the International Study of Asthma and Allergies in Childhood allowed to identify active wheezing (at least one wheeze episode in the previous 12 months) in 16.5% of the studied children. Although not statistically significant, the studied children's exposure to indoor air pollution in nursery and primary schools seemed to be associated with an increase in the odds of having active wheezing especially for PM2.5 (OR = 1.57, p-value = 0.675). These results highlight the importance of applying indoor air pollution mitigation measures in nursery and primary schools. The impacts of those measures, on both indoor air quality and children's respiratory health, should be evaluated in future studies. (c) 2019 WIT Pres
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