Efeitos de combinações entre o ácido anacárdico derivado da casca da castanha do caju (Anacardium occidentale) e o óleo de açaí (Euterpe oleracea Mart.), livres ou nanoestruturados, no tratamento de células de câncer de pele não melanoma, in vitro

Dissertação (mestrado)—Universidade de Brasília, Instituto de Ciências Biológicas, Pós-Graduação em Nanociência e Nanobiotecnologia, 2017.O Câncer de Pele Não Melanoma (CNPM) o tipo de câncer que possui maior incidência no Brasil e no mundo. O ácido anacárdico (AA) é um composto proveniente da casca da castanha do caju (Anacardium occidentale) que vem atraindo grande interesse nos últimos anos devido ás suas propriedades antitumorais, antibióticas, gastroprotetoras e antioxidantes. O açaí (Euterpe oleracea Mart.) também vem atraindo a atenção de pesquisadores, por ser rico em polifenóis com atividades como supressão tumoral, antiproliferativo e pró-apoptótica. Grande parte desses fitoquímicos que possuem atividades terapêuticas são pouco solúveis em soluções aquosas, o que dificulta sua administração e absorção no organismo. Desta forma, a encapsulação desses compostos em nanoestruturas se torna uma alternativa plausível para potencializar seus efeitos biológicos. Diante do exposto, o presente projeto de pesquisa tem como objetivo avaliar os efeitos de combinações entre o ácido anacárdico (AA) derivado da casca da castanha do caju (Anacardium occidentale) e o óleo de açaí (Euterpe oleracea Mart.), livres ou nanoestruturados, no tratamento de câncer de pele não melanoma in vitro. Os testes de estabilidade mostraram que a nanoemulsão à base de óleo de açaí (AçNE) apresentaram gotículas com diâmetro hidrodinâmico de ± 140 nm, com índice de polidespersão de 0,229, potencial de superfície de ± 17,6 mV e pH 7 por 120 dias. Foi possível modificar a superfície das AçNE adicionando polímeros de quitosana (CH), polietileno glicol (PEG) e fosfolipídios catiônicos DOTAP (1,2-Dioleoiloxi-3-(trimetilamónio) propano). Tais formulações não apresentaram efeito citotóxico nas linhagens A431 e HaCaT, independentemente do tipo de superfície. Os tratamentos AçNE associado ao AA provocaram uma significativa redução na viabilidade das células A431, porém não foi observado efeito de sinergismo entre os mesmos. Em contrapartida, quando ambos compostos foram adicionados na forma não-nanoestruturada, observou-se redução de 90% da viabilidade de células A431 em 24 horas. Dados de citometria de fluxo indicam que a combinação dos compostos livres resulta em morte celular por apoptose e bloqueio do ciclo celular. O presente estudo sugere que a combinação de óleo de açaí e AA é uma promissora alternativa terapêutica antitumoral a ser mais explorada em estudos futuros.Non-Melanoma Skin Cancer (CNPM) is the type of cancer that has the highest incidence in Brazil and worldwide. Anacardic acid (AA) is a compound derived from cashew nuts (Anacardium occidentale) that has attracted great interest in recent years due to its antitumor, antibiotic, gastroprotective and antioxidant properties. Açaí (Euterpe oleracea Mart.) has also attracted the attention of researchers, because it is rich in polyphenols which shows great activity as a tumor suppressor, antiproliferative and pro-apoptotic. Most of these phytochemicals that have therapeutic activities are poorly soluble in aqueous solutions, which hinders their administration and absorption in the body. In this way, the encapsulation of these compounds in nanostructures becomes a plausible alternative to enhance their biological effects. Thus, the present research project has the objective of evaluating the effects of anacardic acid (AA) derived from cashew nut shell (Anacardium occidentale) and açaí oil (Euterpe oleracea Mart.), free or nanostructured, in the treatment of non-melanoma skin cancer in vitro. The stability tests showed that the açaí oil-based nanoemulsion (AçNE) showed droplets with a hydrodynamic diameter of ± 140 nm, with a polydispersion index of 0.229, surface potential of ± 17.6 mV and pH 7 for 120 days. It was possible to modify the surface of the AçNE by adding polymers of chitosan (CH), polyethylene glycol (PEG) and cationic phospholipids DOTAP (1,2-Dioleoyloxy-3- (trimethylammonium) propane). Such formulations showed no cytotoxic effect on the A431 and HaCaT cell lines, regardless of surface type. The AçNE treatments associated with AA caused a significant reduction in the viability of A431 cells, but no synergism was observed between them. On the other hand, when both compounds were added in the non-nanostructured form, a 90% reduction in the viability of A431 cells was observed in 24 hours. Flow cytometry data indicate that the combination of the free compounds results in cell death by apoptosis and cell cycle block. The present study suggests that the combination of acai oil and AA is a promising alternative antitumor therapy to be further explored in future studies

Sexual Size Dimorphism and Body Condition in the Australasian Gannet

Funding: The research was financially supported by the Holsworth Wildlife Research Endowment. Acknowledgments We thank the Victorian Marine Science Consortium, Sea All Dolphin Swim, Parks Victoria, and the Point Danger Management Committee for logistical support. We are grateful for the assistance of the many field volunteers involved in the study.Peer reviewedPublisher PD

Millimeter-scale genetic gradients and community-level molecular convergence in a hypersaline microbial mat

To investigate the extent of genetic stratification in structured microbial communities, we compared the metagenomes of 10 successive layers of a phylogenetically complex hypersaline mat from Guerrero Negro, Mexico. We found pronounced millimeter-scale genetic gradients that were consistent with the physicochemical profile of the mat. Despite these gradients, all layers displayed near-identical and acid-shifted isoelectric point profiles due to a molecular convergence of amino-acid usage, indicating that hypersalinity enforces an overriding selective pressure on the mat community

Current and Historical Drivers of Landscape Genetic Structure Differ in Core and Peripheral Salamander Populations

With predicted decreases in genetic diversity and greater genetic differentiation at range peripheries relative to their cores, it can be difficult to distinguish between the roles of current disturbance versus historic processes in shaping contemporary genetic patterns. To address this problem, we test for differences in historic demography and landscape genetic structure of coastal giant salamanders (Dicamptodon tenebrosus) in two core regions (Washington State, United States) versus the species' northern peripheral region (British Columbia, Canada) where the species is listed as threatened. Coalescent-based demographic simulations were consistent with a pattern of post-glacial range expansion, with both ancestral and current estimates of effective population size being much larger within the core region relative to the periphery. However, contrary to predictions of recent human-induced population decline in the less genetically diverse peripheral region, there was no genetic signature of population size change. Effects of current demographic processes on genetic structure were evident using a resistance-based landscape genetics approach. Among core populations, genetic structure was best explained by length of the growing season and isolation by resistance (i.e. a ‘flat’ landscape), but at the periphery, topography (slope and elevation) had the greatest influence on genetic structure. Although reduced genetic variation at the range periphery of D. tenebrosus appears to be largely the result of biogeographical history rather than recent impacts, our analyses suggest that inherent landscape features act to alter dispersal pathways uniquely in different parts of the species' geographic range, with implications for habitat management

Ancestral absence of electron transport chains in Patescibacteria and DPANN

© The Author(s), 2020. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Beam, J. P., Becraft, E. D., Brown, J. M., Schulz, F., Jarett, J. K., Bezuidt, O., Poulton, N. J., Clark, K., Dunfield, P. F., Ravin, N. V., Spear, J. R., Hedlund, B. P., Kormas, K. A., Sievert, S. M., Elshahed, M. S., Barton, H. A., Stott, M. B., Eisen, J. A., Moser, D. P., Onstott, T. C., Woyke, T., & Stepanauskas, R. Ancestral absence of electron transport chains in Patescibacteria and DPANN. Frontiers in Microbiology, 11, (2020): 1848, doi:10.3389/fmicb.2020.01848.Recent discoveries suggest that the candidate superphyla Patescibacteria and DPANN constitute a large fraction of the phylogenetic diversity of Bacteria and Archaea. Their small genomes and limited coding potential have been hypothesized to be ancestral adaptations to obligate symbiotic lifestyles. To test this hypothesis, we performed cell–cell association, genomic, and phylogenetic analyses on 4,829 individual cells of Bacteria and Archaea from 46 globally distributed surface and subsurface field samples. This confirmed the ubiquity and abundance of Patescibacteria and DPANN in subsurface environments, the small size of their genomes and cells, and the divergence of their gene content from other Bacteria and Archaea. Our analyses suggest that most Patescibacteria and DPANN in the studied subsurface environments do not form specific physical associations with other microorganisms. These data also suggest that their unusual genomic features and prevalent auxotrophies may be a result of ancestral, minimal cellular energy transduction mechanisms that lack respiration, thus relying solely on fermentation for energy conservation.This work was funded by the USA National Science Foundation grants 1441717, 1826734, and 1335810 (to RS); and 1460861 (REU site at Bigelow Laboratory for Ocean Sciences). RS was also supported by the Simons Foundation grant 510023. TW, FS, and JJ were funded by the U.S. Department of Energy Joint Genome Institute, a DOE Office of Science User Facility supported under Contract No. DE-AC02-05CH11231. NR group was funded by the Russian Science Foundation (grant 19-14-00245). SS was funded by USA National Science Foundation grants OCE-0452333 and OCE-1136727. BH was funded by NASA Exobiology grant 80NSSC17K0548

SARS-CoV-2 evolution during treatment of chronic infection

SARS-CoV-2 Spike protein is critical for virus infection via engagement of ACE21, and is a major 54 antibody target. Here we report chronic SARS-CoV-2 with reduced sensitivity to neutralising 55 antibodies in an immune suppressed individual treated with convalescent plasma, generating 56 whole genome ultradeep sequences over 23 time points spanning 101 days. Little change was 57 observed in the overall viral population structure following two courses of remdesivir over the 58 first 57 days. However, following convalescent plasma therapy we observed large, dynamic 59 virus population shifts, with the emergence of a dominant viral strain bearing D796H in S2 and 60 H69/V70 in the S1 N-terminal domain NTD of the Spike protein. As passively transferred 61 serum antibodies diminished, viruses with the escape genotype diminished in frequency, before 62 returning during a final, unsuccessful course of convalescent plasma. In vitro, the Spike escape 63 double mutant bearing H69/V70 and D796H conferred modestly decreased sensitivity to 64 convalescent plasma, whilst maintaining infectivity similar to wild type. D796H appeared to be 65 the main contributor to decreased susceptibility but incurred an infectivity defect. The 66 H69/V70 single mutant had two-fold higher infectivity compared to wild type, possibly 67 compensating for the reduced infectivity of D796H. These data reveal strong selection on SARS68 CoV-2 during convalescent plasma therapy associated with emergence of viral variants with 69 evidence of reduced susceptibility to neutralising antibodies.COG-UK is supported by funding from the Medical Research Council (MRC) part of UK Research & Innovation (UKRI), the National Institute of Health Research (NIHR) and Genome Research Limited, operating as the Wellcome Sanger Institute

Deep Sequencing of the Vaginal Microbiota of Women with HIV

BACKGROUND: Women living with HIV and co-infected with bacterial vaginosis (BV) are at higher risk for transmitting HIV to a partner or newborn. It is poorly understood which bacterial communities constitute BV or the normal vaginal microbiota among this population and how the microbiota associated with BV responds to antibiotic treatment. METHODS AND FINDINGS: The vaginal microbiota of 132 HIV positive Tanzanian women, including 39 who received metronidazole treatment for BV, were profiled using Illumina to sequence the V6 region of the 16S rRNA gene. Of note, Gardnerella vaginalis and Lactobacillus iners were detected in each sample constituting core members of the vaginal microbiota. Eight major clusters were detected with relatively uniform microbiota compositions. Two clusters dominated by L. iners or L. crispatus were strongly associated with a normal microbiota. The L. crispatus dominated microbiota were associated with low pH, but when L. crispatus was not present, a large fraction of L. iners was required to predict a low pH. Four clusters were strongly associated with BV, and were dominated by Prevotella bivia, Lachnospiraceae, or a mixture of different species. Metronidazole treatment reduced the microbial diversity and perturbed the BV-associated microbiota, but rarely resulted in the establishment of a lactobacilli-dominated microbiota. CONCLUSIONS: Illumina based microbial profiling enabled high though-put analyses of microbial samples at a high phylogenetic resolution. The vaginal microbiota among women living with HIV in Sub-Saharan Africa constitutes several profiles associated with a normal microbiota or BV. Recurrence of BV frequently constitutes a different BV-associated profile than before antibiotic treatment

The Role of Natural Killer (NK) Cells and NK Cell Receptor Polymorphisms in the Assessment of HIV-1 Neutralization

The importance of innate immune cells in HIV-1 pathogenesis and protection has been highlighted by the role of natural killer (NK) cells in the containment of viral replication. Use of peripheral blood mononuclear cells (PBMC) in immunologic studies provides both HIV-1 target cells (ie. CD4+ T cells), as well as anti-HIV-1 effector cells, such as NK cells. In this study, NK and other immune cell populations were analyzed in HIV-negative donor PBMC for an impact on the anti-HIV activity of polyclonal and monoclonal antibodies. NK cell percentages were significantly higher in donor PBMC that supported lower levels of viral replication. While the percentage of NK cells was not directly associated with neutralization titers, NK cell-depletion significantly diminished the antiviral antibody activity by up to three logs, and polymorphisms in NK killer immunoglobulin receptor (KIR) and FcγRIIIa alleles appear to be associated with this affect. These findings demonstrate that NK cells and NK cell receptor polymorphisms may influence assessment of traditional HIV-1 neutralization in a platform where antibody is continuously present. This format appears to simultaneously assess conventional entry inhibition (neutralization) and non-neutralizing antibody-dependent HIV inhibition, which may provide the opportunity to delineate the dominant antibody function(s) in polyclonal vaccine responses

Controlling Viral Immuno-Inflammatory Lesions by Modulating Aryl Hydrocarbon Receptor Signaling

Ocular herpes simplex virus infection can cause a blinding CD4+ T cell orchestrated immuno-inflammatory lesion in the cornea called Stromal Keratitis (SK). A key to controlling the severity of SK lesions is to suppress the activity of T cells that orchestrate lesions and enhance the representation of regulatory cells that inhibit effector cell function. In this report we show that a single administration of TCDD (2, 3, 7, 8- Tetrachlorodibenzo-p-dioxin), a non-physiological ligand for the AhR receptor, was an effective means of reducing the severity of SK lesions. It acted by causing apoptosis of Foxp3- CD4+ T cells but had no effect on Foxp3+ CD4+ Tregs. TCDD also decreased the proliferation of Foxp3- CD4+ T cells. The consequence was an increase in the ratio of Tregs to T effectors which likely accounted for the reduced inflammatory responses. In addition, in vitro studies revealed that TCDD addition to anti-CD3/CD28 stimulated naïve CD4+ T cells caused a significant induction of Tregs, but inhibited the differentiation of Th1 and Th17 cells. Since a single TCDD administration given after the disease process had been initiated generated long lasting anti-inflammatory effects, the approach holds promise as a therapeutic means of controlling virus induced inflammatory lesions