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In Triatoma infestans it was observed pyrethroid resistance attributed in part to an elevated oxidative metabolism mediated by cytochromes P450. The nicotinamide adenine dinucleotide phosphate (NADPH) cytochrome P450 reductase (CPR) plays a crucial role in catalysing the electron transfer from NADPH to all cytochrome P450s. The daily variations in the expression of CPR gene and a P450 gene (CYP4EM7), both associated with insecticide resistance, suggested that their expressions would be under the endogenous clock control. To clarify the involvement of the clock in orchestration of the daily fluctuations in CPR and CYP4M7 genes expression, it was proposed to investigate the effect of silencing the clock gene period (per) by RNA interference (RNAi). The results obtained allowed to establish that the silencing of per gene was influenced by intake schemes used in the interference protocols. The silencing of per gene in T. infestans reduced its expression at all the time points analysed and abolished the characteristic rhythm in the transcriptional expression of per mRNA. The effect of the per gene silencing in the expression profiles at the transcriptional level of CPR and CYP4EM7 genes showed the loss of rhythmicity and demonstrated the biological clock involvement in the regulation of t heir expression.
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Ritmo Circadiano , Resistência a Inseticidas , Interferência de RNA , Triatoma , Animais , Triatoma/genética , Triatoma/efeitos dos fármacos , Resistência a Inseticidas/genética , Ritmo Circadiano/genética , Proteínas de Insetos/genética , Proteínas de Insetos/metabolismo , Regulação da Expressão Gênica/efeitos dos fármacos , Sistema Enzimático do Citocromo P-450/genética , NADPH-Ferri-Hemoproteína Redutase/genética , NADPH-Ferri-Hemoproteína Redutase/metabolismo , Vetores de DoençasRESUMO
Plants continuously endure unpredictable environmental fluctuations that upset their physiology, with stressful conditions negatively impacting yield and survival. As a contemporary threat of rapid progression, global warming has become one of the most menacing ecological challenges. Thus, understanding how plants integrate and respond to elevated temperatures is crucial for ensuring future crop productivity and furthering our knowledge of historical environmental acclimation and adaptation. While the canonical heat-shock response and thermomorphogenesis have been extensively studied, evidence increasingly highlights the critical role of regulatory epigenetic mechanisms. Among these, the involvement under heat of heterochromatic suppression mediated by transcriptional gene silencing (TGS) remains the least understood. TGS refers to a multilayered metabolic machinery largely responsible for the epigenetic silencing of invasive parasitic nucleic acids and the maintenance of parental imprints. Its molecular effectors include DNA methylation, histone variants and their post-translational modifications, and chromatin packing and remodeling. This work focuses on both established and emerging insights into the contribution of TGS to the physiology of plants under stressful high temperatures. We summarized potential roles of constitutive and facultative heterochromatin as well as the most impactful regulatory genes, highlighting events where the loss of epigenetic suppression has not yet been associated with corresponding changes in epigenetic marks.
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Epigênese Genética , Regulação da Expressão Gênica de Plantas , Inativação Gênica , Resposta ao Choque Térmico/genética , Temperatura Alta , Metilação de DNA , Plantas/genética , Plantas/metabolismo , Heterocromatina/genética , Heterocromatina/metabolismoRESUMO
Plants evolved, over millions of years, complex defense systems against pathogens. Once infected, the interaction between pathogen effector molecules and host receptors triggers plant immune responses, which include apoptosis, systemic immune response, among others. An important protein family responsible for pathogen effector recognition is the nucleotide binding site-leucine repeat rich (NBS-LRR) proteins. The NBS-LRR gene family is the largest disease resistance gene class in plants. These proteins are widely distributed in vascular plants and have a complex multigenic cluster distribution in plant genomes. To counteract the genetic load of such a large gene family on fitness cost, plants evolved a mechanism using post transcriptional gene silencing induced by small RNAs, particularly microRNAs. For the NBS-LRR gene family, the small RNAs involved in this silencing mechanism are mainly the microRNA482/2118 superfamily. This suppression mechanism is relieved upon pathogen infection, thus allowing increased NBS-LRR expression and triggering plant immunity. In this review, we will discuss the biogenesis of microRNAs and secondary RNAs involved in this silencing mechanism, biochemical and structural features of NBS-LRR proteins in response to pathogen effectors and the evolution of microRNA-based silencing mechanism with a focus on the miR482/2118 family. Furthermore, the biotechnological manipulation of microRNA expression, using both transgenic or genome editing approaches to improve cultivated plants will be discussed, with a focus on the miR482/2118 family in soybean.
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Regulação da Expressão Gênica de Plantas , MicroRNAs , Imunidade Vegetal , Proteínas de Plantas , MicroRNAs/genética , Imunidade Vegetal/genética , Proteínas de Plantas/genética , Resistência à Doença/genética , Resistência à Doença/imunologia , Produtos Agrícolas/genética , Produtos Agrícolas/imunologia , Doenças das Plantas/genética , Doenças das Plantas/imunologia , Doenças das Plantas/microbiologiaRESUMO
INTRODUCTION: Breast cancer is one of the main causes of death in women. Luminal tumors A and B show good response with hormonal treatments, tumors that overexpress HER-2 can be treated with monoclonal antibodies, whereas triple negative tumors have few treatments available because they present low or absent expression of hormone receptors and HER-2, in addition, they present worse tumor progression. Syndecans are heparan sulfate proteoglycans that have the function of interacting with growth factors, cytokines, and extracellular matrix, thus modulating important processes in tumor progression. OBJECTIVE: Analyze the expression of syndecan-4 in different subtypes of breast tumors. METHODS: Bioinformatics is a useful tool for the study of new biomarkers. In the present study, the TCGA database (514 patients) and Metabric (1,898 patients) were analyzed using the cBioportal software. Gene expression data were analyzed by RNA-Seq and Microarray from biopsies of breast tumors. RESULTS: An alteration in syndecan-4 gene expression was observed among the different subtypes of breast tumors. Patients with a triple-negative tumor had decreased expression for syndecan-4 in both databases. CONCLUSION: Syndecan-4 is a potential biomarker for breast tumor prognosis since decreased expression of syndecan-4 is related to triple-negative breast cancer.
INTRODUÇÃO: O câncer de mama corresponde a uma das principais causas de morte em mulheres. Os tumores luminais A e B apresentam boa resposta com tratamentos hormonais, os tumores que superexpressam HER-2 podem ser tratados com anticorpos monoclonais, já os tumores triplo-negativos apresentam poucos tratamentos disponíveis por apresentarem expressão baixa ou ausente dos receptores hormonais e HER-2, além de pior progressão tumoral. Os sindecans são proteoglicanos de heparam sulfato que tem função de interagir com fatores de crescimento, citocinas e matriz extracelular, modulando assim processos importantes na progressão tumoral. OBJETIVO: Analisar a expressão o sindecam-4 nos diferentes subtipos de tumores de mama. MÉTODOS: A bioinformática vem se mostrando útil para estudo de novos biomarcadores. No presente estudo, foi analisado o banco de dados TCGA (514 pacientes) e Metabric (1898 pacientes) utilizando o software cBioportal. Foram analisados os dados de expressão gênica por RNA-Seq e Microarray. RESULTADOS: Foi verificada alteração de expressão gênica do sindecam-4 entre os diferentes subtipos de tumores de mama. Pacientes com tumor triplo-negativo tiveram a expressão diminuída para sindecam-4 em ambos os bancos de dados. CONCLUSÃO: Foi verificado que sindecam-4 parece ser um potencial biomarcador em tumores de mama, a expressão diminuída de sindecam-4 parece estar relacionada a um pior prognóstico.
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Humanos , Neoplasias da Mama , Biomarcadores Tumorais , Expressão Gênica , Sindecana-4 , Biologia ComputacionalRESUMO
The RE-1 silencing transcription factor (REST) is a repressor factor related to neuroendocrine prostate cancer (PCa) (NEPC), a poor prognostic stage mainly associated with castration-resistant PCa (CRPC). NEPC is associated with cell transdifferentiation and the epithelial-mesenchymal transition (EMT) in cells undergoing androgen deprivation therapy (ADT) and enzalutamide (ENZ). The effect of REST overexpression in the 22rv1 cell line (xenograft-derived prostate cancer) on EMT, migration, invasion, and the viability for ENZ was evaluated. EMT genes, Twist and Zeb1, and the androgen receptor (AR) were evaluated through an RT-qPCR and Western blot in nuclear and cytosolic fractions of REST-overexpressing 22rv1 cells (22rv1-REST). The migratory and invasive capacities of 22rv1-REST cells were evaluated via Transwell® assays with and without Matrigel, respectively, and their viability for enzalutamide via MTT assays. The 22rv1-REST cells showed decreased nuclear levels of Twist, Zeb1, and AR, and a decreased migration and invasion and a lower viability for ENZ compared to the control. Results were expressed as the mean + SD of three independent experiments (Mann-Whitney U test, Kruskal-Wallis, Tukey test). REST behaves like a tumor suppressor, decreasing the aggressiveness of 22rv1 cells, probably through the repression of EMT and the neuroendocrine phenotype. Furthermore, REST could represent a response marker to ENZ in PCa patients.
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Benzamidas , Nitrilas , Feniltioidantoína , Neoplasias de Próstata Resistentes à Castração , Neoplasias da Próstata , Masculino , Humanos , Neoplasias da Próstata/metabolismo , Antagonistas de Androgênios , Fatores de Transcrição , Linhagem Celular Tumoral , Receptores Androgênicos/metabolismo , Transição Epitelial-Mesenquimal/genética , Neoplasias de Próstata Resistentes à Castração/patologiaRESUMO
Fungi belonging to the genus Pseudogymnoascus have garnered increasing attention in recent years. One of the members of the genus, P. destructans, has been identified as the causal agent of a severe bat disease. Simultaneously, the knowledge of Pseudogymnoascus species has expanded, in parallel with the increased availability of genome sequences. Moreover, Pseudogymnoascus exhibits great potential as a producer of specialized metabolites, displaying a diverse array of biological activities. Despite these significant advancements, the genetic landscape of Pseudogymnoascus remains largely unexplored due to the scarcity of suitable molecular tools for genetic manipulation. In this study, we successfully implemented RNAi-mediated gene silencing and CRISPR/Cas9-mediated disruption in Pseudogymnoascus, using an Antarctic strain of Pseudogymnoascus verrucosus as a model. Both methods were applied to target azpA, a gene involved in red pigment biosynthesis. Silencing of the azpA gene to levels of 90% or higher eliminated red pigment production, resulting in transformants exhibiting a white phenotype. On the other hand, the CRISPR/Cas9 system led to a high percentage (73%) of transformants with a one-nucleotide insertion, thereby inactivating azpA and abolishing red pigment production, resulting in a white phenotype. The successful application of RNAi-mediated gene silencing and CRISPR/Cas9-mediated disruption represents a significant advancement in Pseudogymnoascus research, opening avenues for comprehensive functional genetic investigations within this underexplored fungal genus.
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Quem pode falar no divã? Como a inscrição do sujeito e do sujeito do inconsciente em relações sociais de poder de classe, gênero, sexualidade, raça, idade, validade, limita o acesso a uma elaboração analítica? O reconhecimento da colonialidade, como efeito de dominação e lugar de enunciação que persiste além da colonização, tornou possível a emergência de novas formas subjetivas, culturais e epistêmicas, incentivando a psicanálise a escutar de outra forma. Este artigo propõe se debruçar sobre a incidência da raça e da branquitude na psicanálise a partir das epistemologias do posicionamento e da epistemologia da ignorância. No contexto social francês, enquanto uma parte crescente da população francesa experimenta diariamente a discriminação racial, essa é veementemente negada por uma maioria de político·as e pesquisadore·as, que recusam até o uso da palavra "raça". A partir dessa negação oficial do racismo sistémico pelo poder político e por uma maioria de estudos acadêmicos, o artigo tenta analisar a epistemologia da ignorância que prevalece na postura clínica e teórica de uma psicanálise maioritária. Trata-se de estudar a forma como uma ignorância branca provoca uma desescuta das questões de raça no divã, produz efeitos transferenciais de silenciamento, e nega vivências particulares em nome do universalismo.
Who can speak on the couch? How does the inscription of the subject and the subject of the unconscious in class, gender, sexuality, race, age and validity social power relations limit access to a psychoanalytical elaboration? The recognition of coloniality as an effect of domination and a locus of enunciation that persists beyond colonisation has made it possible for new subjective, cultural and epistemic forms to emerge, encouraging psychoanalysis to listen differently. This article looks at the impact of race and whiteness on psychoanalysis through the perspective of the Standpoint Epistemologies and the Epistemology of Ignorance. In the French social context, while a growing part of the French population experiences racial discrimination on a daily basis, it is vehemently denied by a majority of politicians and researchers, who refuse to even use the word "race". Starting from this official denial of systemic racism by the political establishment and a majority of academic studies, the article seeks to analyse the epistemology of ignorance that prevails in the clinical and theoretical stance of a majoritian psychoanalysis. The aim is to study the way in which white ignorance causes race issues to be non-listened to on the couch produces silencing transferential effects, and denies particular experiences in the name of universalism.
¿Quién puede hablar en el diván? ¿Cómo la inscripción del sujeto y del sujeto del inconsciente en las relaciones sociales de poder de clase, género, sexualidad, raza, edad, validez, limitan el acceso a una elaboración analítica? El reconocimiento de la colonialidad como un efecto de dominación y un lugar de enunciación que persiste más allá de la colonización ha posibilitado la emergencia de nuevas formas subjetivas, culturales y epistémicas, impulsionando al psicoanálisis a escuchar de otra manera. Este artículo examina el impacto de la raza y la blanquitud en el psicoanálisis desde la perspectiva de las epistemologías del posicionamiento y la epistemología de la ignorancia. En el contexto social francés, mientras que una parte creciente de la población francesa experimenta a diario la discriminación racial, ésta es negada con vehemencia por una mayoría de políticos/as e investigadores/as, que se niegan incluso a utilizar la palabra "raza". Partiendo de esta negación oficial del racismo sistémico por parte del poder político y de una mayoría de estudios académicos, el artículo intenta analizar la epistemología de la ignorancia que prevalece en la postura clínica y teórica de un psicoanálisis mayoritario. El objetivo es estudiar el modo en que la ignorancia blanca hace que las cuestiones raciales sean des-escuchadas en el diván, produce efectos transferenciales de silenciamiento y niega las experiencias particulares en nombre del universalismo.
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Psicanálise , Interpretação Psicanalítica , Grupos Raciais , Racismo , Política , NarcisismoRESUMO
Amylomyces rouxii is a zygomycete that produces extracellular protease and tyrosinase. The tyrosinase activity is negatively regulated by the proteases and, which attempts to purify the tyrosinase (tyr) enzyme that has been hampered by the presence of a protease that co-purified with it. In this work we identified genes encoding aspartic protease II (aspII) and VI of A. rouxii. Using an RNAi strategy based on the generation of a siRNA by transcription from two opposite-orientated promoters, the expression of these two proteases was silenced, showing that this molecular tool is suitable for gene silencing in Amylomyces. The transformant strains showed a significant attenuation of the transcripts (determined by RT-qPCR), with respective inhibition of the protease activity. In the case of aspII, inhibition was in the range of 43-90 % in different transformants, which correlated well with up to a five-fold increase in tyr activity with respect to the wild type and control strains. In contrast, silencing of aspVI caused a 43-65 % decrease in protease activity but had no significant effect on the tyr activity. The results show that aspII has a negative effect on tyr activity, and that the silencing of this protease is important to obtain strains with high levels of tyr activity.
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Ácido Aspártico Proteases , Mucorales , RNA Interferente Pequeno , Monofenol Mono-Oxigenase/genética , Monofenol Mono-Oxigenase/metabolismo , Ácido Aspártico Proteases/genética , Ácido Aspártico Proteases/metabolismo , Mucorales/genéticaRESUMO
The leafhopper Dalbulus maidis is a harmful pest that causes severe damage to corn crops. Conventional chemical pesticides have negative environmental impacts, emphasizing the need for alternative solutions. RNA interference (RNAi) is a more specific and environmentally friendly method for controlling pests and reducing the negative impacts of current pest management practices. Previous studies have shown that orally administered double-stranded RNA (dsRNA) is less effective than injection protocols in silencing genes. This study focuses on identifying and understanding the role of double-stranded ribonucleases (dsRNases) in limiting the efficiency of oral RNAi in D. maidis. Three dsRNases were identified and characterized, with Dmai-dsRNase-2 being highly expressed in the midgut and salivary glands. An ex vivo degradation assay revealed significant nuclease activity, resulting in high instability of dsRNA when exposed to tissue homogenates. Silencing Dmai-dsRNase-2 improved the insects' response to the dsRNA targeting the gene of interest, providing evidence of dsRNases involvement in oral RNAi efficiency. Therefore, administering both dsRNase-specific and target gene-specific-dsRNAs simultaneously is a promising approach to increase the efficiency of oral RNAi and should be considered in future control strategies.
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Hemípteros , Ribonucleases , Animais , Ribonucleases/genética , Ribonucleases/metabolismo , Interferência de RNA , Zea mays/genética , Zea mays/metabolismo , Hemípteros/genética , Hemípteros/metabolismo , Insetos/genética , RNA de Cadeia Dupla/genéticaRESUMO
Subtelomeric gene silencing is the negative transcriptional regulation of genes located close to telomeres. This phenomenon occurs in a variety of eukaryotes with salient physiological implications, such as cell adherence, virulence, immune-system escape, and ageing. The process has been widely studied in the budding yeast Saccharomyces cerevisiae, where genes involved in this process have been identified mostly on a gene-by-gene basis. Here, we introduce a quantitative approach to study gene silencing, that couples the classical URA3 reporter with GFP monitoring, amenable to high-throughput flow cytometry analysis. This dual silencing reporter was integrated into several subtelomeric loci in the genome, where it showed a gradual range of silencing effects. By crossing strains with this dual reporter at the COS12 and YFR057W subtelomeric query loci with gene-deletion mutants, we carried out a large-scale forward screen for potential silencing factors. The approach was replicable and allowed accurate detection of expression changes. Results of our comprehensive screen suggest that the main players influencing subtelomeric silencing were previously known, but additional potential factors underlying chromatin conformation are involved. We validate and report the novel silencing factor LGE1, a protein with unknown molecular function required for histone H2B ubiquitination. Our strategy can be readily combined with other reporters and gene perturbation collections, making it a versatile tool to study gene silencing at a genome-wide scale.
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Proteínas de Saccharomyces cerevisiae , Saccharomycetales , Proteínas de Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/metabolismo , Proteínas Reguladoras de Informação Silenciosa de Saccharomyces cerevisiae/genética , Proteínas Reguladoras de Informação Silenciosa de Saccharomyces cerevisiae/metabolismo , Saccharomycetales/genética , Saccharomycetales/metabolismo , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Telômero/genética , Telômero/metabolismo , Heterocromatina/metabolismo , Regulação Fúngica da Expressão GênicaRESUMO
Small interfering RNA (siRNA) molecules have limited transfection efficiency and stability, necessitating the use of delivery systems to be effective in gene knockdown therapies. In this regard, lipid-polymeric nanocarriers have emerged as a promising class of nanoparticles for siRNA delivery, particularly for topical applications. We proposed the use of solid lipid-polymer hybrid nanoparticles (SLPHNs) as topical delivery systems for siRNA. This approach was evaluated by assessing the ability of SLPHNs-siRNA complexes to internalize siRNA molecules and both to penetrate skin layers in vitro and induce gene knocking down in a skin cell line. The SLPHNs were formed by a specific composition of solid lipids, a surfactant polymer as a dispersive agent, and a cationic polymer as a complexing agent for siRNA. The optimized nanocarriers exhibited a spherical shape with a smooth surface. The average diameter of the nanoparticles was found to be 200 nm, and the zeta potential was measured to be +20 mV. Furthermore, these nanocarriers demonstrated excellent stability when stored at 4 °C over a period of 90 days. In vitro and in vivo permeation studies showed that SLPHNs increased the cutaneous penetration of fluorescent-labeled siRNA, which reached deeper skin layers. Efficacy studies were conducted on keratinocytes and fibroblasts, showing that SLPHNs maintained cell viability and high cellular uptake. Furthermore, SLPHNs complexed with siRNA against Firefly luciferase (siLuc) reduced luciferase expression, proving the efficacy of this nanocarrier in providing adequate intracellular release of siRNA for silencing specific genes. Based on these results, the developed carriers are promising siRNA delivery systems for skin disease therapy.
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Cysteine-rich receptor-like kinases (CRKs) are a type of receptor-like kinases (RLKs) that are important for pathogen resistance, extracellular reactive oxygen species (ROS) signaling, and programmed cell death in plants. In a previous study, we identified 46 CRK family members in the Phaseolus vulgaris genome and found that CRK12 was highly upregulated under root nodule symbiotic conditions. To better understand the role of CRK12 in the Phaseolus-Rhizobia symbiotic interaction, we functionally characterized this gene by overexpressing (CRK12-OE) and silencing (CRK12-RNAi) it in a P. vulgaris hairy root system. We found that the constitutive expression of CRK12 led to an increase in root hair length and the expression of root hair regulatory genes, while silencing the gene had the opposite effect. During symbiosis, CRK12-RNAi resulted in a significant reduction in nodule numbers, while CRK12-OE roots showed a dramatic increase in rhizobial infection threads and the number of nodules. Nodule cross sections revealed that silenced nodules had very few infected cells, while CRK12-OE nodules had enlarged infected cells, whose numbers had increased compared to controls. As expected, CRK12-RNAi negatively affected nitrogen fixation, while CRK12-OE nodules fixed 1.5 times more nitrogen than controls. Expression levels of genes involved in symbiosis and ROS signaling, as well as nitrogen export genes, supported the nodule phenotypes. Moreover, nodule senescence was prolonged in CRK12-overexpressing roots. Subcellular localization assays showed that the PvCRK12 protein localized to the plasma membrane, and the spatiotemporal expression patterns of the CRK12-promoter::GUS-GFP analysis revealed a symbiosis-specific expression of CRK12 during the early stages of rhizobial infection and in the development of nodules. Our findings suggest that CRK12, a membrane RLK, is a novel regulator of Phaseolus vulgaris-Rhizobium tropici symbiosis.
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Phaseolus , Rhizobium tropici , Rhizobium , Simbiose/genética , Rhizobium tropici/genética , Rhizobium tropici/metabolismo , Phaseolus/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Raízes de Plantas/genética , Raízes de Plantas/metabolismo , Rhizobium/metabolismo , Fixação de Nitrogênio/genética , Nódulos Radiculares de Plantas/metabolismoRESUMO
BACKGROUND: Changes in Caveolin-1 (CAV-1) expression are related to tumorigenesis. The aim of this study was to evaluate the role of CAV-1 in tumor progression in oral squamous cell carcinoma (SCC) tissue samples and the effect of CAV-1 silencing on two oral tongue SCC (OTSCC) cell lines (SCC-25, from a primary tumor, and HSC-3 from lymph node metastases). METHODS: Mycroarray hybridization, mRNA expression, and immunohistochemistry were performed on OSCC tissue samples and corresponding non-tumoral margin tissues. The effects of CAV-1 silencing (siCAV-1) on cell viability, membrane fluidity, on the expression of epithelial to mesenchymal transition (EMT) markers and on cell migration and invasion capacity of OTSCC cell lines were evaluated. RESULTS: Microarray showed a greater CAV-1 expression (1.77-fold) in OSCC tumors than in non-tumoral tissues and 2.0-fold more in less aggressive OSCCs. However, significant differences in CAV-1 gene expression were not seen between tumors and non-tumoral margins nor CAV-1 with any clinicopathological parameters. CAV-1 protein was localized both in carcinoma and in spindle cells of the tumor microenvironment (TME), and CAV-1 positive TME cells were associated with smaller/more aggressive tumors, independent of the carcinoma cells' expression. Silencing of CAV-1 increased cell viability only in SCC-25 cells. It also stimulated the invasion of HSC-3 cells and increased ECAD and BCAT mRNA in these cells; however, the protein levels of the EMT markers were not affected. CONCLUSION: Decreased expression of CAV-1 by tumor cells in OSCC and an increase in the TME were associated with increased cell invasiveness and tumor aggressiveness.
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Carcinoma de Células Escamosas , Neoplasias de Cabeça e Pescoço , Neoplasias Bucais , Humanos , Neoplasias Bucais/patologia , Carcinoma de Células Escamosas/patologia , Carcinoma de Células Escamosas de Cabeça e Pescoço , Caveolina 1/genética , Caveolina 1/metabolismo , Transição Epitelial-Mesenquimal , RNA Mensageiro , Linhagem Celular Tumoral , Microambiente TumoralRESUMO
The impending need for increasing amounts of food for the world population poses enormous challenges to agriculture. Moreover, global warming has exacerbated abiotic and biotic stresses, accelerating the emergence of new pests and pathogens which threatens crop productivity. Therefore, the scientific community urgently needs to develop innovative solutions for sustainable agriculture, notably replacing synthetic pesticides by active and highly specific biomolecules for pest control. In this context, RNA-based technologies emerge as an outstanding genetically modified organism-free approach offering versatile solutions to boost productivity while conserving and harnessing the wide variety of local landraces. Here we review recent advances in the field, including RNA synthesis approaches and the development of the nanotechnology required for RNA stabilization and delivery, and we discuss the potential of RNA as the key molecule for versatile applications in the second green revolution.
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Agricultura , Nanotecnologia , Produtos Agrícolas/genéticaRESUMO
Pest control methods that can target pest species with limited environmental impacts are a conservation and economic priority. Species-specific pest control using RNA interference is a challenging but promising avenue in developing the next generation of pest management. We investigate the feasibility of manipulating a biological invader's immune system using double-stranded RNA (dsRNA) in order to increase susceptibility to naturally occurring pathogens. We used the invasive Argentine ant as a model, targeting the immunity-associated genes Spaetzle and Dicer-1 with dsRNA. We show that feeding with Spaetzle dsRNA can result in partial target gene silencing for up to 28 days in the laboratory and 5 days in the field. Dicer-1 dsRNA only resulted in partial gene knockdown after 2 days in the laboratory. Double-stranded RNA treatments were associated with significant gene expression disruptions across immune pathways in the laboratory and to a lower extent in the field. In total, 12 viruses and four bacteria were found in these ant populations. Some changes in viral loads in dsRNA-treated groups were observed. For example, Linepithema humile Polycipivirus 2 (LhuPCV2) loads increased after 2 days of treatment with Spaetzle and Dicer-1 dsRNA treatments in the laboratory. After treatment with the dsRNA in the field, after 5 days the virus Linepithema humile toti-like virus 1 (LhuTLV1) was significantly more abundant. However, immune pathway disruption did not result in a consistent increase in microbial infections, nor did it alter ant abundance in the field. Some viruses even declined in abundance after dsRNA treatment. Our study explored the feasibility of lowering a pest's immunity as a control tool. We demonstrate that it is possible to alter immune gene expression of pest species and pathogen loads, although in our specific system the affected pathogens did not appear to influence pest abundance. We provide suggestions on future directions for dsRNA-mediated immune disruption in pest species, including potential avenues to improve dsRNA delivery as well as the importance of pest and pathogen biology. Double-stranded RNA targeting immune function might be especially useful for pest control in systems in which viruses or other microorganisms are prevalent and have the potential to be pathogenic.
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Formigas , Vírus , Animais , RNA de Cadeia Dupla , Inativação Gênica , Interferência de RNA , Vírus/genéticaRESUMO
Chronic Non-Communicable Diseases (NCDs) have been considered a global health problem, characterized as diseases of multiple factors, which are developed throughout life, and regardless of genetics as a risk factor of important relevance, the increase in mortality attributed to the disease to environmental factors and the lifestyle one leads. Although the reactive species (ROS/RNS) are necessary for several physiological processes, their overproduction is directly related to the pathogenesis and aggravation of NCDs. In contrast, dietary polyphenols have been widely associated with minimizing oxidative stress and inflammation. In addition to their antioxidant power, polyphenols have also drawn attention for being able to modulate both gene expression and modify epigenetic alterations, suggesting an essential involvement in the prevention and/or development of some pathologies. Therefore, this review briefly explained the mechanisms in the development of some NCDs, followed by a summary of some evidence related to the interaction of polyphenols in oxidative stress, as well as the modulation of epigenetic mechanisms involved in the management of NCDs.
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For many years we have studied the processes involved in producing miRNAs in plants and the numerous differences from their metazoan counterpart. A well-defined catalytic process, mostly carried out by the RNase III enzyme DICER-LIKE1 (DCL1), it was identified early after the discovery of RNAi and was followed by the isolation of a plethora of miRNA biogenesis cofactors. The production of miRNAs, which later are loaded in ARGONAUTE (AGO) proteins to perform their RNA silencing functions both within the cell and non-cell autonomously, appears to be a highly regulated and dynamic process. Many regulatory events during miRNA biogenesis require the action of specific proteins. However, in recent years, many post-transcriptional modifications, structural features, and coupling with other cellular processing emerged as critical elements controlling the production of miRNA and, thus, a plant's physiology. This review discusses new evidence that has changed the way we understand how miRNAs are produced in plants. We also provide an updated view of the miRNA biogenesis pathways, focusing on the gaps in our knowledge and the most compelling questions that remain open.
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Proteínas de Arabidopsis , Arabidopsis , MicroRNAs , Animais , Proteínas de Arabidopsis/metabolismo , Arabidopsis/genética , MicroRNAs/genética , MicroRNAs/metabolismo , Proteínas de Ligação a RNA/genética , Plantas/genética , Plantas/metabolismoRESUMO
Resumo Este artigo é um desdobramento da tese de doutorado que trata das relações e processos de subjetivação entre equipes técnicas e famílias na rede de saúde mental. Neste contexto, o trabalho aborda forças conservadoras e possibilidades de resistência ao poder. O racismo está presente no cotidiano de pessoas que convivem com situações de sofrimento mental, mas poucas vezes esse marcador social é abordado nos serviços, caracterizando o silenciamento de experiências vividas. A metodologia utilizada foi a cartografia, incluindo pesquisa de campo, permitindo rastreamento de processos e considerando o posicionamento político de quem pesquisa, com orientação para práticas comprometidas com transformações sociais. A análise dos dados produzidos associa perspectiva interseccional sobre as demandas em saúde mental à esquizoanálise, buscando a construções de saída dos impasses entre familiares e equipes. Concluímos que sustentando indagações sobre modos de nos relacionar e revisitar nossa história, podemos construir práticas coletivas antirracistas na saúde mental.
Resumen Este artículo es fruto de una tesis doctoral que aborda las relaciones y los procesos de subjetivación entre los equipos técnicos y las familias en la red de salud mental. Aborda las fuerzas conservadoras y las posibilidades de resistencia al poder. El racismo está presente en el cotidiano de las personas que viven con sufrimiento mental, pero ese marcador social raramente es abordado en los servicios, caracterizando el silenciamiento de las experiencias vividas. La metodología utilizada fue la cartografía, incluyendo la investigación de campo, permitiendo rastrear procesos y teniendo en cuenta el posicionamiento político hacia prácticas comprometidas con la transformación social. El análisis de los datos asocia perspectiva interseccional de las demandas de salud mental con el esquizoanálisis, con búsquedas de salidas a los impasses entre familiares y equipos. Concluimos que apoyando preguntas sobre los modos de relacionarnos y revisitando nuestra historia, podemos construir prácticas colectivas antirracistas en salud mental.
Abstract This article is an offshoot of a doctoral thesis that deals with the relationships and processes of subjectivation between technical teams and families in the mental health network. In this context, it deals with conservative forces and possibilities of resistance to power. Racism is present in the daily lives of people who live with situations of mental suffering, but this social marker is rarely addressed in the services, characterizing the silencing of lived experiences. Cartography was the methodology used, including field research, which allows processes to be traced and takes into account the political positioning of the researcher towards practices committed to social transformation. The analysis of the data produced associates an intersectional perspective on mental health demands with schizoanalysis, seeking ways out of the impasse between family members and teams. We conclude that by supporting questions about ways of relating and revisiting our history, we can build anti-racist collective practices in mental health.
Assuntos
Família , Saúde Mental , Racismo , Racismo Sistêmico/prevenção & controle , Serviços de Saúde MentalRESUMO
Invasive insects cost the global economy around USD 70 billion per year. Moreover, increasing agricultural insect pests raise concerns about global food security constraining and infestation rising after climate changes. Current agricultural pest management largely relies on plant breeding-with or without transgenes-and chemical pesticides. Both approaches face serious technological obsolescence in the field due to plant resistance breakdown or development of insecticide resistance. The need for new modes of action (MoA) for managing crop health is growing each year, driven by market demands to reduce economic losses and by consumer demand for phytosanitary measures. The disabling of pest genes through sequence-specific expression silencing is a promising tool in the development of environmentally-friendly and safe biopesticides. The specificity conferred by long dsRNA-base solutions helps minimize effects on off-target genes in the insect pest genome and the target gene in non-target organisms (NTOs). In this review, we summarize the status of gene silencing by RNA interference (RNAi) for agricultural control. More specifically, we focus on the engineering, development and application of gene silencing to control Lepidoptera through non-transforming dsRNA technologies. Despite some delivery and stability drawbacks of topical applications, we reviewed works showing convincing proof-of-concept results that point to innovative solutions. Considerations about the regulation of the ongoing research on dsRNA-based pesticides to produce commercialized products for exogenous application are discussed. Academic and industry initiatives have revealed a worthy effort to control Lepidoptera pests with this new mode of action, which provides more sustainable and reliable technologies for field management. New data on the genomics of this taxon may contribute to a future customized target gene portfolio. As a case study, we illustrate how dsRNA and associated methodologies could be applied to control an important lepidopteran coffee pest.
Assuntos
Lepidópteros , Praguicidas , Animais , Interferência de RNA , Insetos/genética , RNA de Cadeia Dupla/genética , Inativação Gênica , Lepidópteros/genética , Praguicidas/farmacologiaRESUMO
Cotton is the most important crop for fiber production worldwide. However, the cotton boll weevil (CBW) is an insect pest that causes significant economic losses in infested areas. Current control methods are costly, inefficient, and environmentally hazardous. Herein, we generated transgenic cotton lines expressing double-stranded RNA (dsRNA) molecules to trigger RNA interference-mediated gene silencing in CBW. Thus, we targeted three essential genes coding for chitin synthase 2, vitellogenin, and ecdysis-triggering hormone receptor. The stability of expressed dsRNAs was improved by designing a structured RNA based on a viroid genome architecture. We transformed cotton embryos by inserting a promoter-driven expression cassette that overexpressed the dsRNA into flower buds. The transgenic cotton plants were characterized, and positive PCR transformed events were detected with an average heritability of 80%. Expression of dsRNAs was confirmed in floral buds by RT-qPCR, and the T1 cotton plant generation was challenged with fertilized CBW females. After 30 days, data showed high mortality (around 70%) in oviposited yolks. In adult insects fed on transgenic lines, chitin synthase II and vitellogenin showed reduced expression in larvae and adults, respectively. Developmental delays and abnormalities were also observed in these individuals. Our data remark on the potential of transgenic cotton based on a viroid-structured dsRNA to control CBW.