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A proper balance of metabolic pathways is crucial for engineering microbial strains that can efficiently produce biochemicals on an industrial scale while maintaining cell fitness. High production loads can negatively impact cell fitness and hinder industrial-scale production. To address this, fine-tuning gene expression using engineered promoters and genetic circuits can promote control over multiple targets in pathways and reduce the burden. We took advantage of the robust carbon catabolite repression system of Bacillus subtilis to engineer a glucose-inducible genetic circuit that supports growth and production. The circuit is resilient, enabling a quick switch in the production status when exposed to the correct carbon source. By performing serial cultivations for 61 generations under repressive conditions, we preserved the production capacity of the cells, which could be fully accessed by switching to glucose in the next cultivation step. Switching to glucose after 61 generations resulted in 34-fold activation and generated 70% higher production in comparison to standard cultivation in glucose. Conversely, serial cultivation under permanent induction resulted in 62% production loss after 67 generations alongside an increase in the culture growth rate. As a pathway-independent circuit activated by the preferred carbon source, our engineered glucose-inducible genetic circuit is broadly useful and imposes no additional cost to traditional production processes.
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Glucose , Redes e Vias Metabólicas , Glucose/metabolismo , Carbono/metabolismo , Bacillus subtilis/metabolismoRESUMO
Drosophila melanogaster DAxud1 is a transcription factor that belongs to the Cysteine Serine Rich Nuclear Protein (CSRNP) family, conserved in metazoans, with a transcriptional transactivation activity. According to previous studies, this protein promotes apoptosis and Wnt signaling-mediated neural crest differentiation in vertebrates. However, no analysis has been conducted to determine what other genes it might control, especially in connection with cell survival and apoptosis. To partly answer this question, this work analyzes the role of Drosophila DAxud1 using Targeted-DamID-seq (TaDa-seq), which allows whole genome screening to determine in which regions it is most frequently found. This analysis confirmed the presence of DAxud1 in groups of pro-apoptotic and Wnt pathway genes, as previously described; furthermore, stress resistance genes that coding heat shock protein (HSP) family genes were found as hsp70, hsp67, and hsp26. The enrichment of DAxud1 also identified a DNA-binding motif (AYATACATAYATA) that is frequently found in the promoters of these genes. Surprisingly, the following analyses demonstrated that DAxud1 exerts a repressive role on these genes, which are necessary for cell survival. This is coupled with the pro-apoptotic and cell cycle arrest roles of DAxud1, in which repression of hsp70 complements the maintenance of tissue homeostasis through cell survival modulation.
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Drosophila melanogaster , Drosophila , Animais , Drosophila/genética , Drosophila/metabolismo , Drosophila melanogaster/genética , Drosophila melanogaster/metabolismo , Fatores de Transcrição de Choque Térmico/metabolismo , Resposta ao Choque Térmico/genética , Proteínas de Choque Térmico HSP70/genética , Proteínas de Choque Térmico HSP70/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismoRESUMO
Epigenetic repression has been linked to the regulation of different cell states. In this study, we focus on the influence of this repression, mainly by H3K27me3, over gene expression in muscle cells, which may affect mineral content, a phenotype that is relevant to muscle function and beef quality. Based on the inverse relationship between H3K27me3 and gene expression (i.e., epigenetic repression) and on contrasting sample groups, we computationally predicted regulatory genes that affect muscle mineral content. To this end, we applied the TRIAGE predictive method followed by a rank product analysis. This methodology can predict regulatory genes that might be affected by repressive epigenetic regulation related to mineral concentration. Annotation of orthologous genes, between human and bovine, enabled our investigation of gene expression in the Longissimus thoracis muscle of Bos indicus cattle. The animals under study had a contrasting mineral content in their muscle cells. We identified candidate regulatory genes influenced by repressive epigenetic mechanisms, linking histone modification to mineral content in beef samples. The discovered candidate genes take part in multiple biological pathways, i.e., impulse transmission, cell signalling, immunological, and developmental pathways. Some of these genes were previously associated with mineral content or regulatory mechanisms. Our findings indicate that epigenetic repression can partially explain the gene expression profiles observed in muscle samples with contrasting mineral content through the candidate regulators here identified.
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Lignocellulosic biomass is a renewable raw material for producing several high-value-added chemicals and fuels. In general, xylose and glucose are the major sugars in biomass hydrolysates, and their efficient utilization by microorganisms is critical for an economical production process. Yeasts capable of co-consuming mixed sugars might lead to higher yields and productivities in industrial fermentation processes. Herein, we performed adaptive evolution assays with two xylose-fermenting yeasts, Spathaspora passalidarum and Scheffersomyces stipitis, to obtain derived clones with improved capabilities of glucose and xylose co-consumption. Adapted strains were obtained after successive growth selection using xylose and the non-metabolized glucose analog 2-deoxy-D-glucose as a selective pressure. The co-fermentation capacity of evolved and parental strains was evaluated on xylose-glucose mixtures. Our results revealed an improved co-assimilation capability by the evolved strains; however, xylose and glucose consumption were observed at slower rates than the parental yeasts. Genome resequencing of the evolved strains revealed genes affected by non-synonymous variants that might be involved with the co-consumption phenotype, including the HXT2.4 gene that encodes a putative glucose transporter in Sp. passalidarum. Expression of this mutant HXT2.4 in Saccharomyces cerevisiae improved the cells' co-assimilation of glucose and xylose. Therefore, our results demonstrated the successful improvement of co-fermentation through evolutionary engineering and the identification of potential targets for further genetic engineering of different yeast strains. KEY POINTS: ⢠Laboratory evolution assay was used to obtain improved sugar co-consumption of non-Saccharomyces strains. ⢠Evolved Sp. passalidarum and Sc. stipitis were able to more efficiently co-ferment glucose and xylose. ⢠A mutant Hxt2.4 permease, which co-transports xylose and glucose, was identified.
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Glucose , Xilose , Xilose/metabolismo , Glucose/metabolismo , Fermentação , Saccharomyces cerevisiae/metabolismo , FenótipoRESUMO
Microbial strategies for biomass deconstruction involve an incredible repertoire of enzymatic, structural, and regulatory proteins. From carbohydrate active enzymes to cellulosomes, bacteria, yeast, and filamentous fungi adapt their functional machinery to grow from alternative carbon sources such as lignocellulose and survive starvation. In that context, microbes must be able to sense, bind, degrade, and utilize lignin, cellulose, and hemicelluloses. Nature has developed specialized protein modules, RNA structures, and regulatory systems operating at a genomic, transcription, and translation level. This review briefly summarizes the main regulatory pathways involved in lignocellulose microbial degradation, including carbon catabolite repression; anti-sigma factors; regulatory RNA elements such as small RNAs, antisense RNA, RNA-binding proteins, and selective RNA processing and stabilization; and transcriptional regulators and unfolded protein response. Interplay with global regulators controlling pH response and nitrogen utilization is also revised.
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Celulose , Lignina , Lignina/metabolismo , Celulose/metabolismo , Bactérias/genética , Bactérias/metabolismo , Fungos/metabolismoRESUMO
The production of biofuels, such as bioethanol from lignocellulosic biomass, is an important task within the sustainable energy concept. Understanding the metabolism of ethanologenic microorganisms for the consumption of sugar mixtures contained in lignocellulosic hydrolysates could allow the improvement of the fermentation process. In this study, the ethanologenic strain Escherichia coli MS04 was used to ferment hydrolysates from five different lignocellulosic agroindustrial wastes, which contained different glucose and xylose concentrations. The volumetric rates of glucose and xylose consumption and ethanol production depend on the initial concentration of glucose and xylose, concentrations of inhibitors, and the positive effect of acetate in the fermentation to ethanol. Ethanol yields above 80% and productivities up to 1.85 gEtOH/Lh were obtained. Furthermore, in all evaluations, a simultaneous co-consumption of glucose and xylose was observed. The effect of deleting the xyIR regulator was studied, concluding that it plays an important role in the metabolism of monosaccharides and in xylose consumption. Moreover, the importance of acetate was confirmed for the ethanologenic strain, showing the positive effect of acetate on the co-consumption rates of glucose and xylose in cultivation media and hydrolysates containing sugar mixtures.
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Repressão Catabólica , Escherichia coli , Fermentação , Escherichia coli/metabolismo , Xilose/metabolismo , Glucose/metabolismo , Açúcares/metabolismo , Etanol/metabolismoRESUMO
Nitrogen is a crucial nutrient for microorganisms that compose essential biomolecules. However, hosts limit this nutrient as a strategy to counter infections, therefore, pathogens use adaptive mechanisms to uptake nitrogen from alternative sources. In fungi, nitrogen catabolite repression (NCR) activates transcription factors to acquire nitrogen from alternative sources when preferential sources are absent. Formamidase has been related to nitrogen depletion in Aspergillus nidulans through formamide degradation to use the released ammonia as a nitrogen source. In Paracoccidioides spp., formamidase is highly expressed in transcriptomic and proteomic analyses. Here, we aim to investigate the importance of formamidase to Paracoccidioides lutzii. Thereby, we developed a P. lutzii silenced strain of fmd gene (AsFmd) by antisense RNA technology using Agrobacterium tumefaciens-mediated transformation (ATMT). The AsFmd strain led to increased urease expression, an enzyme related to nitrogen assimilation in other fungi, suggesting that P. lutzii might explore urease as an alternative route for ammonia metabolism as a nitrogen source. Moreover, formamidase was important for fungal survival inside macrophages, as fungal recovery after macrophage infection was lower in AsFmd compared to wild-type (WT) strain. Our findings suggest potential alternatives of nitrogen acquisition regulation in P. lutzii, evidencing formamidase influence in fungal virulence.
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Phytochemicals (Pch) present in fruits, vegetables and other foods, are known to inhibit or induce drug metabolism and transport. An exhaustive search was performed in five databases covering from 2000 to 2021. Twenty-one compounds from plants were found to modulate CYP3A and/or P-gp activities and modified the pharmacokinetics and the therapeutic effect of 27 different drugs. Flavonols, flavanones, flavones, stilbenes, diferuloylmethanes, tannins, protoalkaloids, flavans, hyperforin and terpenes, reduce plasma concentration of cyclosporine, simvastatin, celiprolol, midazolam, saquinavir, buspirone, everolimus, nadolol, tamoxifen, alprazolam, verapamil, quazepam, digoxin, fexofenadine, theophylline, indinavir, clopidogrel. Anthocyanins, flavonols, flavones, flavanones, flavonoid glycosides, stilbenes, diferuloylmethanes, catechin, hyperforin, alkaloids, terpenes, tannins and protoalkaloids increase of plasma concentration of buspirone, losartan, diltiazem, felodipine, midazolam, cyclosporine, triazolam, verapamil, carbamazepine, diltiazem, aripiprazole, tamoxifen, doxorubicin, paclitaxel, nicardipine. Interactions between Pchs and drugs affect the gene expression and enzymatic activity of CYP3A and P-gp transporter, which has an impact on their bioavailability; such that co-administration of drugs with food, beverages and food supplements can cause a subtherapeutic effect or overdose. Therefore, it is important for the clinician to consider these interactions to obtain a better therapeutic effect.
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Every cell of an organism shares the same genome; even so, each cellular lineage owns a different transcriptome and proteome. The Polycomb group proteins (PcG) are essential regulators of gene repression patterning during development and homeostasis. However, it is unknown how the repressive complexes, PRC1 and PRC2, identify their targets and elicit new Polycomb domains during cell differentiation. Classical recruitment models consider the pre-existence of repressive histone marks; still, de novo target binding overcomes the absence of both H3K27me3 and H2AK119ub. The CpG islands (CGIs), non-core proteins, and RNA molecules are involved in Polycomb recruitment. Nonetheless, it is unclear how de novo targets are identified depending on the physiological context and developmental stage and which are the leading players stabilizing Polycomb complexes at domain nucleation sites. Here, we examine the features of de novo sites and the accessory elements bridging its recruitment and discuss the first steps of Polycomb domain formation and transcriptional regulation, comprehended by the experimental reconstruction of the repressive domains through time-resolved genomic analyses in mammals.
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Segments are repeated anatomical units forming the body of insects. In Drosophila, the specification of the body takes place during the blastoderm through the segmentation cascade. Pair-rule genes such as hairy (h), even-skipped (eve), runt (run), and fushi-tarazu (ftz) are of the intermediate level of the cascade and each pair-rule gene is expressed in seven transversal stripes along the antero-posterior axis of the embryo. Stripes are formed by independent cis-regulatory modules (CRMs) under the regulation of transcription factors of maternal source and of gap proteins of the first level of the cascade. The initial blastoderm of Drosophila is a syncytium and it also coincides with the mid-blastula transition when thousands of zygotic genes are transcribed and their products are able to diffuse in the cytoplasm. Thus, we anticipated a complex regulation of the CRMs of the pair-rule stripes. The CRMs of h 1, eve 1, run 1, ftz 1 are able to be activated by bicoid (bcd) throughout the anterior blastoderm and several lines of evidence indicate that they are repressed by the anterior gap genes slp1 (sloppy-paired 1), tll (tailless) and hkb (huckebein). The modest activity of these repressors led to the premise of a combinatorial mechanism regulating the expression of the CRMs of h 1, eve 1, run 1, ftz 1 in more anterior regions of the embryo. We tested this possibility by progressively removing the repression activities of slp1, tll and hkb. In doing so, we were able to expose a mechanism of additive repression limiting the anterior borders of stripes 1. Stripes 1 respond depending on their distance from the anterior end and repressors operating at different levels.
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Blastoderma , Proteínas de Drosophila , Animais , Blastoderma/metabolismo , Drosophila/genética , Proteínas de Drosophila/genética , Proteínas de Homeodomínio/genética , Fatores de Transcrição/genéticaRESUMO
Xanthophyllomyces dendrorhous is a natural source of astaxanthin and mycosporines. This yeast has been isolated from high and cold mountainous regions around the world, and the production of these secondary metabolites may be a survival strategy against the stress conditions present in its environment. Biosynthesis of astaxanthin is regulated by catabolic repression through the interaction between MIG1 and corepressor CYC8-TUP1. To evaluate the role of the stress-associated transcription factors SKN7, ROX1, and YAP6, we employed an omic and phenotypic approach. Null mutants were constructed and grown in two fermentable carbon sources. The yeast proteome and transcriptome were quantified by iTRAQ and RNA-seq, respectively. The total carotenoid, sterol, and mycosporine contents were determined and compared to the wild-type strain. Each mutant strain showed significant metabolic changes compared to the wild type that were correlated to its phenotype. In a metabolic context, the principal pathways affected were glycolysis/gluconeogenesis, the pentose phosphate (PP) pathway, and the citrate (TCA) cycle. Additionally, fatty acid synthesis was affected. The absence of ROX1 generated a significant decline in carotenoid production. In contrast, a rise in mycosporine and sterol synthesis was shown in the absence of the transcription factors SKN7 and YAP6, respectively.
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Basidiomycota , Proteínas Fúngicas , Metabolismo Secundário , Fatores de Transcrição , Basidiomycota/genética , Basidiomycota/metabolismo , Carotenoides/metabolismo , Proteínas de Ligação a DNA/metabolismo , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Proteínas Repressoras/metabolismo , Esteróis/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismoRESUMO
Cancer development by the human papillomavirus (HPV) infection can occur through the canonical HPV/p53/RB1 pathway mediated by the E2/E6/E7 viral oncoproteins. During the transformation process, HPV inserts its genetic material into host Integration Sites (IS), affecting coding genes and miRNAs. In penile cancer (PeCa) there is limited data on the miRNAs that regulate mRNA targets associated with HPV, such as the TP53 and RB1 genes. Considering the high frequency of HPV infection in PeCa patients in Northeast Brazil, global miRNA expression profiling was performed in high-risk HPV-associated PeCa that presented with TP53 and RB1 mRNA downregulated expression. The miRNA expression profile of 22 PeCa tissue samples and five non-tumor penile tissues showed 507 differentially expressed miRNAs: 494 downregulated and 13 upregulated (let-7a-5p, miR-130a-3p, miR-142-3p, miR-15b-5p miR-16-5p, miR-200c-3p, miR-205-5p, miR-21-5p, miR-223-3p, miR-22-3p, miR-25-3p, miR-31-5p and miR-93-5p), of which 11 were identified to be in HPV16-IS and targeting TP53 and RB1 genes. One hundred and thirty-one and 490 miRNA binding sites were observed for TP53 and RB1, respectively, most of which were in seedless regions. These findings suggest that up-regulation of miRNA expression can directly repress TP53 and RB1 expression by their binding sites in the non-canonical seedless regions.
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BACKGROUND: Despite antiretroviral treatment efficacy, it does not lead to the complete eradication of HIV infection. Consequently, reactivation of the virus from latently infected cell reservoirs is a major challenge toward cure efforts. Two strategies targeting viral latency are currently under investigation: the "shock and kill" and the "block and lock." The "Block and Lock" methodology aims to control HIV-1 latency reactivation, promoting a functional cure. We utilized the CRISPR/dCas9-KRAB platform, which was initially developed to suppress cellular genes transcription, to block drug-induced HIV-1 reactivation in latently infected T cells and myeloid cells. RESULTS: We identified a set of five sgRNAs targeting the HIV-1 proviral genome (LTR1-LTR5), having the lowest nominated off-target activity, and transduced them into the latently infected lymphoid (J-Lat 10.6) and myeloid (U1) cell lines. One of the sgRNAs (LTR5), which binds specifically in the HIV-1 LTR NFκB binding site, was able to promote robust repression of HIV-1 reactivation in latently infected T cells stimulated with Phorbol 12-Myristate 13-Acetate (PMA) and Ingenol B (IngB), both potent protein kinase C (PKC) stimulators. Reactivation with HDAC inhibitors, such as SAHA and Panobinostat, showed the same strong inhibition of reactivation. Additionally, we observed a hundred times reduction of HIV-1 RNA expression levels in the latently infected myeloid cell line, U1 induced with IngB. CONCLUSION: Taken together, our results show that the KRAB fused CRISPR/dCas9 system can robustly prevent the HIV-1 latency reactivation process, mediated by PMA or IngB and SAHA or Panobinostat, both in myeloid and lymphoid HIV-1 latently infected cells. In addition, we demonstrated that KRAB repressor protein is crucial to reactivation resistance phenotype, and we have identified some useful hotspots sequences in HIV-1 LTR for the design sgRNAs.
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Infecções por HIV , HIV-1 , Repetições Palindrômicas Curtas Agrupadas e Regularmente Espaçadas , HIV-1/genética , Humanos , Células Mieloides , Panobinostat/farmacologia , Ativação Viral/genética , Latência ViralRESUMO
À escala globaltem ganhado clara ascendência um paradigma antitráfico associado ao chamado "Protocolo de Palermo", da Organização das Nações Unidas. Considerando as disposições deste protocolo, procuro caracterizar e compreender uma situação que suscita evidentes incongruências estruturais na hegemonia antitráfico: a convivência entre, por um lado, uma definição dilatada do tráfico de pessoas no texto do protocolo e das leis nacionais dele resultantes, e, por outro, a apertada seletividade ideológica que, oscilando de forma quase esquizofrénica entre a compaixão e a repressão, tende apermear os processos de operacionalização dosquadros legais, nomeadamente no que diz respeito ao reconhecimento e proteção das vítimas.
On a global scale, the paradigm of the fight against human trafficking, associated with the so-called "Palermo Protocol" of the United Nations Organization, has acquired a clear ascendancy. Considering the provisions of this protocol, I attempt to characterize and understand a situation that poses evident structural inconsistencies in the anti-trafficking hegemony: the coexistence between, on the one hand, a broad definition of trafficking in persons in the text of the protocol and the resulting national laws, and, on the other, the iron ideological selectivity that, oscillating almost schizophrenically between compassion and repression, tends to permeate the processes of operationalization of legal frameworks, specifically with regard to the recognition and protection of victims.
A escala mundial, el paradigma de la lucha contra la trata de personas, asociado al llamado "Protocolo de Palermo", de la Organización de las Naciones Unidas, ha adquirido una clara ascensión. Considerando las disposiciones de este protocolo, intento caracterizar y comprender una situación que plantea evidentes incoherencias estructurales en la hegemonía antitrata: la coexistencia entre, por una parte, una definición amplia de la trata de personas en el texto del protocolo y las leyes nacionales resultantes, y, por otra, la férrea selectividad ideológica que, oscilando de forma casi esquizofrénica entre la compasión y la represión, tiende a impregnar los procesos de operacionalización de los marcos legales, concretamente en lo que se refiere al reconocimiento y protección de las víctimas.
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Humanos , Empatia , Nações Unidas , Luta Romana , JurisprudênciaRESUMO
The yeast Spathaspora passalidarum is able to produce ethanol from D-xylose and D-glucose. However, it is not clear how xylose metabolism is affected by D-glucose when both sugars are available in the culture medium. The aims of this work were to evaluate the influence of D-glucose on D-xylose consumption, ethanol production, gene expression, and the activity of key xylose-metabolism enzymes under both aerobic and oxygen-limited conditions. Ethanol yields and productivities were increased in culture media containing D-xylose as the sole carbon source or a mixture of D-xylose and D-glucose. S. passalidarum preferentially consumed D-glucose in the co-fermentations, which is consistent with the reduction in expression of genes encoding the key xylose-metabolism enzymes. In the presence of D-glucose, the specific activities of xylose reductase (XR), xylitol dehydrogenase (XDH), and xylulokinase (XK) were lower. Interestingly, in accordance with other studies, the presence of 2-deoxyglucose (2DG) did not inhibit the growth of S. passalidarum in culture medium containing D-xylose as the sole carbon source. This indicates that a non-canonical repression pathway is acting in S. passalidarum. In conclusion, the results suggest that D-glucose inhibits D-xylose consumption and prevents the D-xylose-mediated induction of the genes encoding XR, XDH, and XK.
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Saccharomycetales , Xilose , Glucose , Saccharomyces cerevisiaeRESUMO
Resumen Esta investigación aborda la noción de represión política que, atendiendo a su complejidad, requiere un enfoque interdisciplinario que considera, además de las disciplinas de la historia, las ciencias políticas o la psicología social, los aportes de la filosofía. Interesa precisar que la represión política tiene entre sus objetivos desintegrar la cohesión social y política, mediante la modificación del vínculo del sujeto con el mundo, entendida, en este estudio, como resonancia. Para ello, se investiga el caso del ex Fuerte "El Morro" (1973-1985), centro clandestino de detención y tortura instaurado durante la dictadura chilena cívico militar (1973-1990). Como método, se realizan estudios de caso que consideran entrevistas semiestructuradas, así como la revisión de fuentes de información histórica y de testimonios de sobrevivientes del lugar. Las fuentes secundarias son de tipo académicas, de prensa y audiovisuales. Los principales resultados destacan la noción de resonancia como un modelo que permite comprender, en los vínculos sociales, la relevancia de valores políticos.
Abstract This research addresses the notion of political repression which, considering its complexity, requires an interdisciplinary approach that considers in addition to the disciplines of history, political science or social psychology, the contributions of philosophy. In this regard, the complexity is linked to the semantic richness of the word repression that allows formulating some philosophical questions that can be answered from social psychology regarding the notion of trauma and violence, and from political science considering the concept of social control. Thus, the relationships and distinctions between repression and associated concepts are established in a multidimensional way and through mutual influences. It is interesting to specify that political repression has among its objectives, to disintegrate social and political cohesion, by modifying the subject's bond with the world, which has three dimensions: orientation or disposition to action towards and with the other, values personal, social and political and the nexus with the collective. In this study, resonance is understood as the mutual influence or co-variation between the subject and the world in each of these dimensions in a complementary or synchronous way. To this end, the case of the former Fort "El Morro" (1973-1985), located in the coastal zone of the Biobío region, and with an important historical antecedent of military occupation, which functioned as a clandestine detention and torture center, is being investigated during the Chilean civic-military dictatorship (1973-1990). As a method, case studies are carried out, which consider semi-structured interviews, the objective of which was to account for the experience of repression as a form of harm justified by State agents. Historical information sources that detail the background on the civic military coup in the Biobío region, mainly in the city of Concepción, and testimonies of survivors of the place that relate the repressive events of which they were direct witnesses were also reviewed. The secondary sources are academic, which in this study constitute the interdisciplinary theoretical contributions to support the notion of repression. The secondary press and audiovisual sources used are of a recent nature and reveal other historical antecedents that allowed the declaration of the site as a historical monument. The main results highlight the notion of resonance as a comprehensive model that allows a broad and complex visualization of social and political phenomena such as the case of repression, emphasizing the interactions between the subjects and institutions that make up a socio-political network. The main finding is linked to the concept of resonance, understood not only as an identification of the group with political ideology but as a proposal that, from the contributions of philosophy, articulates social ties with political values. In this regard, the resonance that considers the social ties sustained in political relationships, favors reconsidering subjectivity and social ties in relation to transcendental political principles that guide subjectivities towards the restitution of social and political cohesion. In this sense, resonance can be considered a fundamental notion since it illuminates the nexus between the social and the political from another perspective. In this way, it can be affirmed that a projection of this study consists of exploring political phenomena attending to historical, spatial and temporal dimensions from different disciplines, particularly highlighting the contribution of philosophy, whose questions can collaborate with the study of historical events from new prospects.
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After Candida albicans, Candida glabrata is one of the most common fungal species associated with candidemia in nosocomial infections. Rapid acquisition of nutrients from the host is important for the survival of pathogens which possess the metabolic flexibility to assimilate different carbon and nitrogen compounds. In Saccharomyces cerevisiae, nitrogen assimilation is controlled through a mechanism known as Nitrogen Catabolite Repression (NCR). NCR is coordinated by the action of four GATA factors; two positive regulators, Gat1 and Gln3, and two negative regulators, Gzf3 and Dal80. A mechanism in C. glabrata similar to NCR in S. cerevisiae has not been broadly studied. We previously showed that in C. glabrata, Gln3, and not Gat1, has a major role in nitrogen assimilation as opposed to what has been observed in S. cerevisiae in which both factors regulate NCR-sensitive genes. Here, we expand the knowledge about the role of Gln3 from C. glabrata through the transcriptional analysis of BG14 and gln3Δ strains. Approximately, 53.5% of the detected genes were differentially expressed (DEG). From these DEG, amino acid metabolism and ABC transporters were two of the most enriched KEGG categories in our analysis (Up-DEG and Down-DEG, respectively). Furthermore, a positive role of Gln3 in AAA assimilation was described, as was its role in the transcriptional regulation of ARO8. Finally, an unexpected negative role of Gln3 in the gene regulation of ABC transporters CDR1 and CDR2 and its associated transcriptional regulator PDR1 was found. This observation was confirmed by a decreased susceptibility of the gln3Δ strain to fluconazole.
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Aminoácidos/biossíntese , Candida glabrata/fisiologia , Farmacorresistência Fúngica/genética , Fluconazol/metabolismo , Fatores de Transcrição GATA/metabolismo , Transportadores de Cassetes de Ligação de ATP/genética , Compostos de Amônio/metabolismo , Antifúngicos/metabolismo , Antifúngicos/farmacologia , Candida glabrata/efeitos dos fármacos , Candida glabrata/genética , Candida glabrata/metabolismo , Repressão Catabólica , Farmacorresistência Fúngica/efeitos dos fármacos , Fluconazol/farmacologia , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Fatores de Transcrição GATA/genética , Perfilação da Expressão Gênica , Regulação Fúngica da Expressão Gênica , MutaçãoRESUMO
BACKGROUND: Androgen receptor (AR) and polycomb repressive complex 2 (PRC2) are known to co-occupy the loci of genes that are downregulated by androgen-stimulus. Long intergenic non-coding RNA (lincRNA) PVT1 is an overexpressed oncogene that is associated with AR in LNCaP prostate cancer cells, and with PRC2 in HeLa and many other types of cancer cells. The possible involvement of PVT1 in mediating androgen-induced gene expression downregulation in prostate cancer has not been explored. METHODS: LNCaP cell line was used. Native RNA-binding-protein immunoprecipitation with anti-AR or anti-EZH2 was followed by RT-qPCR with primers for PVT1. Knockdown of PVT1 with specific GapmeRs (or a control with scrambled GapmeR) was followed by differentially expressed genes (DEGs) determination with Agilent microarrays and with Significance Analysis of Microarrays statistical test. DEGs were tested as a tumor risk classifier with a machine learning Random Forest algorithm run with gene expression data from all TCGA-PRAD (prostate adenocarcinoma) tumors as input. ChIP-qPCR was performed for histone marks at the promoter of one DEG. RESULTS: We show that PVT1 knockdown in androgen-stimulated LNCaP cells caused statistically significant expression upregulation/downregulation of hundreds of genes. Interestingly, PVT1 knockdown caused upregulation of 160 genes that were repressed by androgen, including a significantly enriched set of tumor suppressor genes, and among them FAS, NOV/CCN3, BMF, HRK, IFIT2, AJUBA, DRAIC and TNFRSF21. A 121-gene-set (out of the 160) was able to correctly predict the classification of all 293 intermediate- and high-risk TCGA-PRAD tumors, with a mean ROC area under the curve AUC = 0.89 ± 0.04, pointing to the relevance of these genes in cancer aggressiveness. Native RIP-qPCR in LNCaP showed that PVT1 was associated with EZH2, a component of PRC2. PVT1 knockdown followed by ChIP-qPCR showed significant epigenetic remodeling at the enhancer and promoter regions of tumor suppressor gene NOV, one of the androgen-repressed genes that were upregulated upon PVT1 silencing. CONCLUSIONS: Overall, we provide first evidence that PVT1 was involved in signaling a genome-wide androgen-dependent transcriptional repressive program of tumor suppressor protein-coding genes in prostate cancer cells. Identification of transcriptional inhibition of tumor suppressor genes by PVT1 highlights the pathway to the investigation of mechanisms that lie behind the oncogenic role of PVT1 in cancer. Video Abstract.
Assuntos
Regulação Neoplásica da Expressão Gênica , Neoplasias da Próstata/genética , RNA Longo não Codificante/genética , Androgênios , Linhagem Celular Tumoral , Proteína Potenciadora do Homólogo 2 de Zeste/genética , Humanos , Estimativa de Kaplan-Meier , Masculino , Neoplasias da Próstata/mortalidade , Receptores Androgênicos/genética , Transdução de Sinais , Proteínas Supressoras de Tumor/genéticaRESUMO
Background: Androgen receptor (AR) and polycomb repressive complex 2 (PRC2) are known to co-occupy the loci of genes that are downregulated by androgen-stimulus. Long intergenic non-coding RNA (lincRNA) PVT1 is an overexpressed oncogene that is associated with AR in LNCaP prostate cancer cells, and with PRC2 in HeLa and many other types of cancer cells. The possible involvement of PVT1 in mediating androgen-induced gene expression downregulation in prostate cancer has not been explored. Methods: LNCaP cell line was used. Native RNA-binding-protein immunoprecipitation with anti-AR or anti-EZH2 was followed by RT-qPCR with primers for PVT1. Knockdown of PVT1 with specifc GapmeRs (or a control with scrambled GapmeR) was followed by diferentially expressed genes (DEGs) determination with Agilent microarrays and with Signifcance Analysis of Microarrays statistical test. DEGs were tested as a tumor risk classifer with a machine learning Random Forest algorithm run with gene expression data from all TCGA-PRAD (prostate adenocarcinoma) tumors as input. ChIP-qPCR was performed for histone marks at the promoter of one DEG. Results: We show that PVT1 knockdown in androgen-stimulated LNCaP cells caused statistically signifcant expression upregulation/downregulation of hundreds of genes. Interestingly, PVT1 knockdown caused upregulation of 160 genes that were repressed by androgen, including a signifcantly enriched set of tumor suppressor genes, and among them FAS, NOV/CCN3, BMF, HRK, IFIT2, AJUBA, DRAIC and TNFRSF21. A 121-gene-set (out of the 160) was able to correctly predict the classifcation of all 293 intermediate- and high-risk TCGA-PRAD tumors, with a mean ROC area under the curve AUC=0.89±0.04, pointing to the relevance of these genes in cancer aggressiveness. Native RIP-qPCR in LNCaP showed that PVT1 was associated with EZH2, a component of PRC2. PVT1 knockdown followed by ChIP-qPCR showed signifcant epigenetic remodeling at the enhancer and promoter regions of tumor suppressor gene NOV, one of the androgen-repressed genes that were upregulated upon PVT1 silencing. Conclusions: Overall, we provide frst evidence that PVT1 was involved in signaling a genome-wide androgendependent transcriptional repressive program of tumor suppressor protein-coding genes in prostate cancer cells. Identifcation of transcriptional inhibition of tumor suppressor genes by PVT1 highlights the pathway to the investiga‑tion of mechanisms that lie behind the oncogenic role of PVT1 in cancer.
RESUMO
O presente trabalho objetiva analisar a etiologia das neuroses em Freud e Winnicott. Para tanto, parte das principais considerações sobre os mecanismos de defesa, o recalque, a sexualidade, o complexo edípico e o conflito psíquico na psicanálise clássica freudiana, para depois propor uma nova etiologia a partir da teoria das relações objetais em Donald W. Winnicott. Os autores não consideram apenas o conflito vivido em termos da dinâmica psíquica, mas aquele vivido na dinâmica mãe-bebê, principalmente a partir dos polos opostos entre o amor e o ódio na travessia do concernimento (posição depressiva). Os autores defendem um manejo clínico de pacientes com sofrimento psíquico neurótico a partir da psicanálise transmatricial, propondo, concomitantemente à associação livre, o uso da regressão à dependência a fases primitivas de falhas ambientais (AU)
This paper aims to analyze the etiology of the neuroses in Freud and Winnicott. In order to do so, the authors build upon the main considerations on defense mechanisms, repression, sexuality, the oedipal complex, and the psychic conflict in Freudian psychoanalysis. Then they propose a new etiology based on Donald W. Winnicott's object relations theory. The authors do not only consider the conflict experienced in terms of psychic dynamics, but also the conflict experienced in the mother-baby dynamics, particularly in regards to the opposition between love and hate in the development of concern (depressive position). The authors stand for the clinical management of patients with neurotic psychic suffering based on transmatricial psychoanalysis, proposing, along with free association, the use of regression to dependence on primitive phases of environmental failures (AU)
El presente trabajo tiene por objeto analizar la etiología de las neurosis en Freud y Winnicott. Para ello, parte de las principales consideraciones sobre los mecanismos de defensa, la represión, la sexualidad, el complejo edípico y el conflicto psíquico en el psicoanálisis freudiano, para proponer una nueva etiología a partir de la teoría de las relaciones objetivas en Donald W. Winnicott. Los autores no sólo consideran el conflicto vivido en términos de la dinámica psíquica, sino el conflicto vivido en la dinámica madre-bebé, principalmente a partir de los polos opuestos entre el amor y el odio en la travesía de la concernimiento (posición depresiva). Los autores defienden un manejo clínico de pacientes con sufrimiento psíquico neurótico a partir del psicoanálisis transmatricial, proponiendo junto a la asociación libre, el uso de la regresión a la dependencia a fases primitivas de fallas ambientales (AU)