Progress in circular RNAs of plants / 生物工程学报

With the development of high-throughput sequencing technology, circular RNAs (circRNAs) have gradually become a hotspot in the research on non-coding RNA. CircRNAs are produced by the covalent circularization of a downstream 3' splice donor and an upstream 5' splice acceptor through backsplicing, and they are pervasive in eukaryotic cells. CircRNAs used to be considered byproducts of false splicing, whereas an explosion of related studies in recent years has disproved this misconception. Compared with the rich studies of circRNAs in animals, the study of circRNAs in plants is still in its infancy. In this review, we introduced the discovery of plant circRNAs, the discovery of plant circRNAs, the circularization feature, expression specificity, conservation, and stability of plant circRNAs and expounded the identification tools, main types, and biogenesis mechanisms of circRNAs. Furthermore, we summarized the potential roles of plant circRNAs as microRNA (miRNA) sponges and translation templates and in response to biotic/abiotic stress, and briefed the degradation and localization of plant circRNAs. Finally, we discussed the challenges and proposed the future directions in the research on plant circRNAs.

The role and mechanism of leucyl-tRNA synthetase in the regulation of protein synthesis in aging skeletal muscle / 生理学报

The imbalance of protein metabolism is the major cause of skeletal muscle atrophy, and the decrease of protein synthesis directly leads to the occurrence and development of age-related sarcopenia. The canonical role of leucyl-tRNA synthetase (LeuRS) is ligating leucine to the cognate tRNA, and thus it plays a central role in genetic coding. With the further studies of LeuRS in recent years, LeuRS has been found to control protein homeostasis in aging skeletal muscle via its non-canonical role. In this paper, we reviewed the structure and biological features of aminoacyl-tRNA synthetase and LeuRS, and summarized the recent advances in studies on the effects of LeuRS in regulating aging skeletal muscle protein synthesis as an intracellular leucine sensor. Moreover, we also analyzed the potential role of LeuRS in activation of mammalian target of rapamycin complex 1 (mTORC1) signaling transduction pathway in response to anabolic stimuli such as exercise and amino acids ingestion. This paper may provide some new ideas for the prevention, diagnosis and treatment of age-related sarcopenia.

Proteína morfogénica ósea en cirugía maxilofacial. Revisión bibliográfica / Bone morphogenic protein in maxillofacial surgery. Bibliographic review

El propósito de esta revisión es presentar una visión concreta de las proteínas morfogenéticas óseas, su potencial de inducir osteogénesis y la aplicación en los procesos regenerativos. Las investigaciones acerca de los iniciadores moleculares de diferenciación ósea y cartilaginosa han identificado un grupo entero de proteínas morfogenéticas óseas que ejercen efecto regulador. La proteína morfogenética ósea (BMP) es endógena, presenta propiedades osteoinductivas, osteoconductivas y osteogénicas, y ha mostrado efectos significativos en la promoción de la formación ósea, por lo cual es una buena alternativa en reconstrucción. El uso de BMP se ha descrito en la reconstrucción de los defectos óseos de origen traumático y patológico, incluyendo: fisura nasoalveolar, aumento del reborde alveolar, elevación del seno maxilar, injerto de alvéolo postextracción y cirugía peri-implantaria.

The purpose of this review is to present a concrete vision about bone morphogenetic proteins, their potential in the induction of osteogenesis and their application in regenerative processes. Research on the molecular primers of bone and cartilage differentiation has identified an entire group of bone morphogenetic proteins that exert a regulatory effect. The bone morphogenetic protein (BMP) is an endogenous protein, has osteoinductive, osteoconductive and osteogenic properties, has shown significant effects in the promotion of bone formation, being a good alternative in reconstruction. The use of BMP has been described in the reconstruction of bone defects of traumatic and pathological origin, including nasoalveolar fissure, increased alveolar ridge, maxillary sinus elevation, post-extraction alveolar graft, and perimplant surgery

High dose vitamin C inhibits proliferation of breast cancer cells through reducing glycolysis and protein synthesis / 浙江大学学报·医学版

OBJECTIVE@#To investigate the effects of high dose vitamin C (VC) on proliferation of breast cancer cells and to explore its mechanisms.@*METHODS@#Human breast cancer cells Bcap37 and MDA-MB-453 were treated with VC at low dose (0.01 mmol/L), medium dose (0.10 mmol/L) and high dose (2.00 mmol/L). Cell proliferation was determined with CCK-8 assay, protein expression was evaluated by Western blot, and the secretion of lactic acid in tumor cells was detected by colorimetric method. Bcap37 cells were inoculated in nude mice, and tumor baring nude mice were intraperitoneally injected with high VC(4 g/kg, VC group, =5)or normal saline (control group, =5) for 24 d. Tumor weight and body weight were calculated.@*RESULTS@# experiments demonstrated that high dose VC significantly inhibited cell proliferation in Bcap37 and MDA-MB-453 cells (all <0.01); the expressions of Glut1 and mTOR signaling pathway-related proteins were decreased (all <0.05); and the secretion of lactic acid was also markedly reduced (all <0.05). experiment showed that the tumor weight was decreased in mice treated with high-dose VC as compared with control group (<0.05), but no difference in body weights between two groups was observed.@*CONCLUSIONS@#High dose VC may inhibit proliferation of breast cancer cells both and through reducing glycolysis and protein synthesis.

Interaction between wheat translationally controlled tumor protein TCTP and SNF1-related protein kinase SnRK1 / 生物工程学报

Translationally controlled tumor proteins (TCTP) and SNF1- related protein kinase (SnRK1) are conserved and widely present in eukaryotic cells. TCTP regulates cell division, plant growth and development, and mediates plant resistance against pathogen infection. SnRK1 participates in a range of physiological processes including sugar metabolism and resistance to abiotic and biotic stresses. Previous work in our laboratory demonstrated that wheat TCTP can respond to Puccinia triticina infection and induce host defense responses. In order to further investigate the mechanism of TaTCTP in wheat resistance to Puccinia triticina infection, we used TAP (tandem affinity purification) and mass spectrometry to screen the potential interactants of TaTCTP. A SNF1- related protein kinase (SnRK1) was identified as a potential interacting protein of TaTCTP. The results of yeast two-hybrid assay showed that TCTP could interact with SnRK1 in yeast, and the yeast carrying TCTP and SnRK1 could grow on SD/-Leu/-Trp/-His/-Ade (SD/-LWHA) medium. The fluorescence signal of the interaction between TCTP and SnRK1 was found to be distributed in the cytoplasm in the Bi-fluorescense complementation experiment. Co-IP experiments further showed that TCTP and SnRK1 could interact in plant cells. This study lays an important foundation for further studying the mechanism of TaTCTP in the interaction between wheat and Puccinia triticina, and it play a great influence on further improving the molecular mechanism of wheat resistant to Puccinia triticina.

Chicken RNA-binding protein T-cell internal antigen-1 contributes to stress granule formation in chicken cells and tissues

T-cell internal antigen-1 (TIA-1) has roles in regulating alternative pre-mRNA splicing, mRNA translation, and stress granule (SG) formation in human cells. As an evolutionarily conserved response to environmental stress, SGs have been reported in various species. However, SG formation in chicken cells and the role of chicken TIA-1 (cTIA-1) in SG assembly has not been elucidated. In the present study, we cloned cTIA-1 and showed that it facilitates the assembly of canonical SGs in both human and chicken cells. Overexpression of the chicken prion-related domain (cPRD) of cTIA-1 that bore an N-terminal green fluorescent protein (GFP) tag (pntGFP-cPRD) or Flag tag (pFlag-cPRD) induced the production of typical SGs. However, C-terminal GFP-tagged cPRD induced notably large cytoplasmic granules that were devoid of endogenous G3BP1 and remained stable when exposed to cycloheximide, indicating that these were not typical SGs, and that the pntGFP tag influences cPRD localization. Finally, endogenous cTIA-1 was recruited to SGs in chicken cells and tissues under environmental stress. Taken together, our study provide evidence that cTIA-1 has a role in canonical SG formation in chicken cells and tissues. Our results also indicate that cPRD is necessary for SG aggregation.

An Emerging Role for Circular RNAs in Osteoarthritis

Circular RNAs (circRNAs) are currently classed as non-coding RNAs that, unlike the better known canonical linear RNAs, form a covalently closed continuous loop without 5′ or 3′ polarities. With the development of high throughput sequencing technology, a large number of circRNAs have been discovered in many species. More importantly, growing evidence suggests that circRNAs are abundant, evolutionally conserved, and relatively stable in cells and tissues. Strikingly, recent studies have discovered that circRNAs can serve as microRNA sponges, interact with RNA-binding protein, and regulate gene transcription, as well as protein translation. Osteoarthritis (OA) is the most common chronic degenerative joint disease. CircRNAs are differentially expressed in OA cartilage. Moreover, some circRNAs are involved in multiple pathological processes during OA, mainly extracellular matrix degradation, inflammation, and apoptosis. In this review, we briefly delineate the biogenesis, characteristics, and biofunctions of circRNAs, and then, focus on the role of circRNAs in the occurrence and progression OA.

RNA binding protein 24 regulates the translation and replication of hepatitis C virus

The secondary structures of hepatitis C virus (HCV) RNA and the cellular proteins that bind to them are important for modulating both translation and RNA replication. However, the sets of RNA-binding proteins involved in the regulation of HCV translation, replication and encapsidation remain unknown. Here, we identified RNA binding motif protein 24 (RBM24) as a host factor participated in HCV translation and replication. Knockdown of RBM24 reduced HCV propagation in Huh7.5.1 cells. An enhanced translation and delayed RNA synthesis during the early phase of infection was observed in RBM24 silencing cells. However, both overexpression of RBM24 and recombinant human RBM24 protein suppressed HCV IRES-mediated translation. Further analysis revealed that the assembly of the 80S ribosome on the HCV IRES was interrupted by RBM24 protein through binding to the 5'-UTR. RBM24 could also interact with HCV Core and enhance the interaction of Core and 5'-UTR, which suppresses the expression of HCV. Moreover, RBM24 enhanced the interaction between the 5'- and 3'-UTRs in the HCV genome, which probably explained its requirement in HCV genome replication. Therefore, RBM24 is a novel host factor involved in HCV replication and may function at the switch from translation to replication.

Avances en la investigación del virus dengue en Colombia: papel de los microARNs celulares en la respuesta anti-dengue virus / Advances in dengue virus research in Colombia: the role of cellular microRNAs as an anti-dengue virus response

Dengue is one of the most important mosquito-borne diseases, and its incidence has increased at an alarming rate in recent years, becoming a real public health problem. Currently, there is no vaccine or medication or proper treatment for dengue control. Considering this situation, it is necessary to prioritize the search for new alternatives and strategies for dengue prevention and control, in order to reduce not only the economic burden of endemic countries, but also to improve the quality of life of patients. In this regard, a brief reflection on some aspects related to the search for new alternatives in Colombia is presented. This is focused on the use of microRNAs, which could be a new strategy with great therapeutic potential.

El dengue es una de las enfermedades más importantes transmitidas por mosquitos y su incidencia ha aumentado a un ritmo alarmante en los últimos años, al punto que se ha convertido en un verdadero problema de salud pública. Actualmente no existe ni vacuna, ni un medicamento o tratamiento adecuado para el control del dengue. Con dichos antecedentes, es necesario priorizar en la búsqueda de nuevas alternativas o estrategias de control y prevención del dengue con miras a disminuir no sólo la carga económica de los países endémicos, sino también a mejorar la calidad de vida de los pacientes. En este sentido, se presenta una breve reflexión sobre algunos aspectos relacionados con la búsqueda de nuevas alternativas en Colombia, enfocadas en el uso de los microARNs, que podrían constituir una nueva estrategia con un gran potencial terapéutico, dado que tendrían el potencial de contrarrestar algunas infecciones virales crónicas.

Measurement of kinetic parameters of skeletal muscle protein synthesis in rats by deuterated water / 生理学报

The aim of the present study was to measure the kinetic parameters of skeletal muscle protein synthesis in rats by deuterated water (HO). Twenty Sprague-Dawley (SD) rats were labeled byHO through intraperitoneal injection and drinking. At the each end of the 1st, 3rd, 5th, 6th and 10th week after the firstHO labeling, four rats were sacrificed by cardiac puncture for blood plasma and quadriceps femoris sampling. Skeletal muscle protein and free amino acids in plasma were purified, hydrolyzed by hydrochloric acid and derived. The deuterium enrichments ofH-labeled alanyl in skeletal muscle protein and plasma protein-boundH-labeled alanine were determined by gas chromatography-mass spectrometry (GC-MS). The fractional synthesis rate of skeletal muscle protein and synthetic dynamic equation were calculated. The fractional synthetic rate of skeletal muscle protein was 12.8%/week, and synthetic dynamic equation was f= 0.158 × (1 - e). The results suggest that the kinetic parameters of skeletal muscle protein synthesis can be measured byHO labeling, and the method can be applied in long-term labeling experiment.

Emerging Roles of microRNAs in Ischemic Stroke: As Possible Therapeutic Agents / 대한뇌졸중학회지

Stroke is one of the leading causes of death and physical disability worldwide. The consequences of stroke injuries are profound and persistent, causing in considerable burden to both the individual patient and society. Current treatments for ischemic stroke injuries have proved inadequate, partly owing to an incomplete understanding of the cellular and molecular changes that occur following ischemic stroke. MicroRNAs (miRNA) are endogenously expressed RNA molecules that function to inhibit mRNA translation and have key roles in the pathophysiological processes contributing to ischemic stroke injuries. Potential therapeutic areas to compensate these pathogenic processes include promoting angiogenesis, neurogenesis and neuroprotection. Several miRNAs, and their target genes, are recognized to be involved in these recoveries and repair mechanisms. The capacity of miRNAs to simultaneously regulate several target genes underlies their unique importance in ischemic stroke therapeutics. In this Review, we focus on the role of miRNAs as potential diagnostic and prognostic biomarkers, as well as promising therapeutic agents in cerebral ischemic stroke.

Hericium erinaceus (Bull.: Fr.) Pers., a medicinal mushroom, activates peripheral nerve regeneration / 中国结合医学杂志

<p><b>OBJECTIVE</b>To study the ability of aqueous extract of Hericium erinaceus mushroom in the treatment of nerve injury following peroneal nerve crush in Sprague-Dawley rats.</p><p><b>METHODS</b>Aqueous extract of Hericium erinaceus was given by daily oral administration following peroneal nerve crush injury in Sprague-Dawley rats. The expression of protein kinase B (Akt) and mitogen-activated protein kinase (MAPK) signaling pathways; and c-Jun and c-Fos genes were studied in dorsal root ganglia (DRG) whereas the activity of protein synthesis was assessed in peroneal nerves by immunohistochemical method.</p><p><b>RESULTS</b>Peripheral nerve injury leads to changes at the axonal site of injury and remotely located DRG containing cell bodies of sensory afferent neurons. Immunofluorescence studies showed that DRG neurons ipsilateral to the crush injury in rats of treated groups expressed higher immunoreactivities for Akt, MAPK, c-Jun and c-Fos as compared with negative control group (P <0.05). The intensity of nuclear ribonucleoprotein in the distal segments of crushed nerves of treated groups was significantly higher than in the negative control group (P <0.05).</p><p><b>CONCLUSION</b>H. erinaceus is capable of promoting peripheral nerve regeneration after injury. Potential signaling pathways include Akt, MAPK, c-Jun, and c-Fos, and protein synthesis have been shown to be involved in its action.</p>

Role of eukaryotic translation initiation factor 4G in tumor / 生理学报

Eukaryotic translation initiation factor 4G (eIF4G) is a scaffold component of eukaryotic translation initiation factor 4F (eIF4F) complex, which takes principal part in the initiating of protein synthesis. Both two subtypes (eIF4G1 and eIF4G2) of eIF4G were found to be closely related with various tumors. The eIF4G1 expression is significantly up-regulated in breast cancer, cervical cancer, nasopharyngeal carcinoma, lung squamous cell carcinoma, prostatic carcinoma and other malignant tumors, compared with those in adjacent tissues; and the eIF4G2 is obviously over-expressed in diffuse large B cell lymphoma and acute myeloid leukemia, but low-expressed in bladder transitional cell carcinoma. This paper reviews the progress in the study of the role of eIF4G in tumor genesis, development, diagnosis and prognosis.

Transcriptome analysis of Pichia pastoris in response to ethanol stress / 生物工程学报

Effective expression of pIFN-α in recombinant Pichia pastoris was conducted in a 5 L fermentor. Ethanol accumulation during the late glycerol feeding period inhibited heterologous protein expression. Comparative transcriptome analysis was thus performed to compare the gene transcription profiles of Pichia pastoris KM71H in high and low ethanol concentration environments. The results showed that during the glycerol cultivation stage, 545 genes (265 up-regulated and 280 down-regulated) were differentially expressed with ethanol stress. These genes were mainly involved in protein synthesis, energy metabolism, cell cycle and peroxisome metabolism. During the methanol induction stage, 294 genes (171 up-regulated and 123 down-regulated) were differentially expressed, which were mainly related to methanol metabolism, amino acid metabolism and protein synthesis. Ethanol stress increased protein misfolding and reduced structural integrity of ribosome and mitochondria during cultivation stage, and led to the failure of endoplasmic reticulum stress removal and damaged amino acid metabolism during induction stage in Pichia pastoris.

Mir-190b negatively contributes to the Trypanosoma cruzi- infected cell survival by repressing PTEN protein expression

Chagas disease, which is caused by the intracellular protozoanTrypanosoma cruzi, is a serious health problem in Latin America. The heart is one of the major organs affected by this parasitic infection. The pathogenesis of tissue remodelling, particularly regarding cardiomyocyte behaviour after parasite infection, and the molecular mechanisms that occur immediately following parasite entry into host cells are not yet completely understood. Previous studies have reported that the establishment of parasitism is connected to the activation of the phosphatidylinositol-3 kinase (PI3K), which controls important steps in cellular metabolism by regulating the production of the second messenger phosphatidylinositol-3,4,5-trisphosphate. Particularly, the tumour suppressor PTEN is a negative regulator of PI3K signalling. However, mechanistic details of the modulatory activity of PTEN on Chagas disease have not been elucidated. To address this question, H9c2 cells were infected with T. cruzi Berenice 62 strain and the expression of a specific set of microRNAs (miRNAs) were investigated. Our cellular model demonstrated that miRNA-190b is correlated to the decrease of cellular viability rates by negatively modulating PTEN protein expression in T. cruzi-infected cells.

Serum insulin-like growth factor-1 levels in females and males in different cervical vertebral maturation stages

OBJECTIVE: The aim of this cross sectional study was to assess serum insulin-like growth factor-1 (IGF-1) levels in female and male subjects at various cervical vertebral maturation (CVM) stages. MATERIAL AND METHODS: The study sample consisted of 60 subjects, 30 females and 30 males, in the age range of 8-23 years. For all subjects, serum IGF-1 level was estimated from blood samples by means of chemiluminescence immunoassay (CLIA). CVM was assessed on lateral cephalograms using the method described by Baccetti. Serum IGF-1 level and cervical staging data of 30 female subjects were included and taken from records of a previous study. Data were analyzed by Kruska-Wallis and Mann Whitney test. Bonferroni correction was carried out and alpha value was set at 0.003. RESULTS: Peak value of serum IGF-1 was observed in cervical stages CS3 in females and CS4 in males. Differences between males and females were observed in mean values of IGF-1 at stages CS3, 4 and 5. The highest mean IGF-1 levels in males was observed in CS4 followed by CS5 and third highest in CS3; whereas in females the highest mean IGF-1 levelswas observed in CS3 followed by CS4 and third highest in CS5. Trends of IGF-1 in relation to the cervical stages also differed between males and females. The greatest mean serum IGF-1 value for both sexes was comparable, for females (397 ng/ml) values were slightly higher than in males (394.8 ng/ml). CONCLUSIONS: Males and females showed differences in IGF-1 trends and levels at different cervical stages. .

OBJETIVO: o objetivo do presente estudo transversal foi avaliar os níveis do fator de crescimento semelhante à insulina-1 (IGF-1 sérico) em pacientes de ambos os sexos e em diferentes estágios de maturação das vértebras cervicais (MVC). MÉTODOS: a amostra consistiu de 60 pacientes, sendo 30 do sexo masculino e 30 do sexo feminino, com idades entre 8 e 23 anos. Amostras de sangue foram colhidas de todos os pacientes, cujos níveis de IGF-1 sérico foram avaliados por meio do método de imunoensaio quimioluminescente (CLIA). O estágio de MVC foi avaliado por meio de radiografias cefalométricas de perfil por meio do método descrito por Baccetti. O nível de IGF-1 sérico e o estágio de maturação das vertebras cervicais de 30 pacientes do sexo feminino foram avaliados e os dados retirados dos registros de um estudo prévio. Os dados foram submetidos aos testes de Kruskal-Wallis e de Mann-Whitney. A correção de Bonferroni foi calculada e o valor de alfa foi de 0,003. RESULTADOS: o valor de pico do IGF-1 sérico foi encontrado no estágio CS3, para mulheres, e CS4, para homens. Foram encontradas diferenças entre as médias dos valores de IGF-1 entre homens e mulheres nos estágios CS3, 4 e 5. O valor médio mais alto para os níveis de IGF-1 nos homens foi observado no estágio CS4, seguido do estágio CS5 e CS3. Nas mulheres, o valor médio mais alto foi observado em CS3, seguido do estágio CS4 e CS5. Diferenças também foram encontradas quanto à curva do IGF-1, em relação ao estágio de maturação das vértebras cervicais nos pacientes de ambos os sexos. O valor médio de IGF-1 sérico mais alto foi comparado. As pacientes do sexo feminino apresentaram valores ligeiramente mais altos (397ng/ml) em comparação aos pacientes do sexo masculino (394.8ng/ml). CONCLUSÕES: homens e mulheres apresentam valores de IGF-1 diferentes em estágios de maturação das vértebras cervicais diferentes. .

Association of junk food consumption with high blood pressure and obesity in Iranian children and adolescents: the CASPIAN-IV Study / Associação entre o consumo de junk food e a pressão arterial alta e obesidade em crianças e adolescentes iranianos: o Estudo Caspian-IV

OBJECTIVE: This study aimed to evaluate the association of junk food consumption with hypertension and obesity in a national sample of Iranian children and adolescents. METHODS: This nationwide study was conducted in 2011-2012 among 14,880 students, aged 6-18 years, selected by cluster sampling from 30 provinces. Weight, height, waist circumference (WC), hip circumference (HC), waist-to-hip ratio (WHR), waist-to-height ratio (WHtR), as well as systolic and diastolic blood pressure (BP) were measured. Junk food was divided into four categories, including salty snacks, sweets, sweetened beverages, and fast food. Subjects reported how many times they had consumed each item (daily, weekly, and seldom). RESULTS: The intake of sweets was significantly associated with anthropometric indices and BP levels. Moreover, a significant association was found between fast food consumption, BP levels, and anthropometric indices (except for WHtR and WHR). Sweet beverages consumption was significantly associated with anthropometric indices; however, the consumption of salty snacks was only significantly associated with height, HC, and WHR. The risk of general obesity (OR: 0.75, 95% CI: 0.65-0.87) and abdominal obesity (OR: 0.81, 95% CI: 0.72-0.92) among participants who seldom consumed sweets was less than those who consumed daily. Also, the risk of general obesity (OR: 0.85, 95% CI: 0.74-0.97) among students that seldom consumed sweetened beverages was less than subjects who consumed them on a daily basis. CONCLUSION: It was found that junk food consumption increased the risk of both general and abdominal obesity; therefore, consumption of junk food should be reduced via restricting TV advertisements and increasing taxes on junk foods. .

OBJETIVO: Avaliar a associação entre o consumo de junk food e a hipertensão e obesidade em uma amostra nacional de crianças e adolescentes iranianos. MÉTODOS: Este estudo nacional foi feito entre 2011 e 2012 com 14.880 estudantes com seis-18 anos, selecionados por amostra em bloco em 30 províncias. Foram medidos o peso, a estatura, a circunferência da cintura (CC), a circunferência do quadril (CQ), a razão cintura/quadril (RCQ), a razão cintura/estatura (RCE) e a pressão arterial sistólica e diastólica (PAS e PAD). A junk food foi dividida em quatro categorias, incluindo lanches salgados, doces, bebidas açucaradas e fast food. Os indivíduos relataram quantas vezes consumiam cada um dos itens (diariamente, semanalmente, raramente). RESULTADOS: O consumo de doces foi associado significativamente aos índices antropométricos e níveis de pressão arterial (PA). Além disso, havia uma associação significativa entre o consumo de fast food e os níveis de PA e os índices antropométricos (exceto RCE e RCQ). O consumo de bebidas açucaradas foi associado significativamente aos índices antropométricos, porém o consumo de lanches salgados foi associado significativamente apenas a estatura, CQ e RCQ. O risco de obesidade geral (RC: 0,75, IC de 95%: 0,65-0,87) e obesidade abdominal (RC: 0,81, IC de 95%: 0,72-0,92) entre participantes que raramente consumiam doces era menor do que naqueles que os consumiam diariamente. Além disso, o risco de obesidade geral (RC: 0,85; IC de 95%: 0,74-0,97) entre estudantes que raramente consumiam bebidas açucaradas era menor do que entre indivíduos que os consumiam diariamente. CONCLUSÃO: Constatamos que o consumo de junk food aumentou o risco de obesidade geral e abdominal; portanto, o consumo de junk food deve ser reduzido por meio da restrição de comerciais de TV e do aumento de impostos sobre esse tipo de alimento. .

Traducción independiente de la estructura 5´cap del ARN genómico del virus dengue / 5´cap-independent translation of dengue virus genomic RNA

Objetivos. Analizar la participación de la caperuza metil-guanosín-trifosfato (5´cap) y de la región inicial del ARN genómico del virus dengue serotipo 2 (DENV-2) genotipo Americano en la traducción, utilizando un sistema libre de células obtenido de placenta humana. Materiales y métodos. Se preparó el plásmido recombinante pTZ18R-D2 conteniendo el ADN que codifica la 5´UTR y los primeros 201 nucleótidos de la cápside viral. Este plásmido se utilizó para transcribir el ARN correspondiente (ARN-D2), sin la 5´cap. El ARN-D2 fue traducido en un sistema constituido por la fracción posmitocondrial (S-30) de placenta humana y se evaluó la incorporación de [14C] aminoácidos en presencia del ARN-D2 y en su ausencia (control). Se diseñaron siete oligonucleótidos antisentido (OAs1-7) dirigidos contra secuencias de las estructuras SLA, SLB y cHP del ARN-D2 y se analizó el efecto de los mismos sobre la traducción ARN-D2. Resultados.El ARN-D2 produjo un incremento significativo (p<0,001) en la incorporación de [14C] aminoácidos, con estimulación del 75% de la actividad traduccional respecto al control. El análisis de los productos de traducción mostró un pico de incorporación correspondiente a péptidos con peso molecular aparente cercano al esperado (7,746 kDa). El OAs5, complementario a una secuencia de la estructura SLB del ARN-D2, inhibió completamente la traducción. Conclusiones. El ARN-D2 fue traducido de manera específica y eficiente, bajo condiciones semejantes a las intracelulares en humanos, por un mecanismo alternativo independiente de la 5´cap, que involucraría a la estructura SLB. Este mecanismo podría considerarse como blanco en el desarrollo de terapias antisentido para inhibir la reproducción del virus.

Objetives. To analyze the involvement of methyl guanosine triphosphate cap (5Æcap) and the start site of the genomic RNA of Dengue virus serotype 2 (DENV-2) American genotype in translation, using a cell-free system prepared from human placenta. Materials and methods. The recombinant plasmid pTZ18R-D2 was prepared containing DNA encoding the 5ÆUTR and the first 201 nucleotides of the viral capsid. This plasmid was used to transcribe the corresponding RNA (RNA-D2) without the 5Æ cap. The RNA-D2 was translated in a system consisting of the postmitochondrial fraction (S-30) from human placenta and the incorporation of [14C] aminoacids in the presence of RNA-D2 and in its absence (control) was evaluated. Seven antisenseoligonucleotides (OAs1-7) directed against sequences of the SLA, SLB and CHP structures of RNA-D2 were designed and the effect thereof on RNA-D2 translation was analyzed. Results.The RNA-D2 produced a significant increase (p<0.001) in the incorporation of [14C] amino acids, with 75% stimulation of translational activity compared to the control. Analysis of the translation products showed peak incorporation corresponding to peptides with apparent molecular weight close to the expected (7.746 kDa).The OAs5, complementary to a sequence of SLB structure of RNA-D2, completely inhibited translation. Conclusions. The RNA-D2 was translated specifically and efficiently under conditions similar to human intracellular conditions, by an alternative 5Æ cap-independent mechanism, which would involve the SLB structure. This mechanism might be seen as an aim in the development of antisense therapies to inhibit virus replication.

Natural transovarial transmission of dengue virus 4 in Aedes aegypti from Cuiabá, State of Mato Grosso, Brazil

INTRODUCTION: Dengue is the most prevalent arboviral disease in tropical areas. In Mato Grosso, outbreaks are reported every year, but studies on dengue in this state are scarce. METHODS: Natural transovarial infection of Aedes aegypti by a flavivirus was investigated in the Jardim Industriário neighborhood of Cuiabá, Mato Grosso. Eggs were collected with ovitraps during the dry, intermediate, and rainy seasons of 2012. After the eggs hatched and the larvae developed to adulthood, mosquitoes (n = 758) were identified and allocated to pools of 1-10 specimens according to the collection location, sex, and climatic period. After RNA extraction, multiplex semi-nested RT-PCR was performed to detect the four dengue virus (DENV) serotypes, yellow fever virus, West Nile virus and Saint Louis encephalitis virus. RESULTS: DENV-4 was the only flavivirus detected, and it was found in 8/50 pools (16.0%). Three of the positive pools contained females, and five contained males. Their nucleotide sequences presented 96-100% similarity with DENV-4 genotype II strains from Manaus, Amazonas. The minimum infection rate was 10.5 per 1000 specimens, and the maximum likelihood estimator of the infection rate was 11.6 (95% confidence interval: 4.8; 23.3). CONCLUSIONS: This study provides the first evidence of natural transovarial infection by DENV-4 in Ae. Aegypti in Mato Grosso, suggesting that this type of infection might serve as a mechanism of virus maintenance during interepidemic periods in Cuiabá, a city where dengue epidemics are reported every year. These results emphasize the need for efficient vector population control measures to prevent arbovirus outbreaks in the state. .

Identificação de motivos relevantes para a função do fator de iniciação da tradução EIF4E3 de Leishmania sp / Identification of relevant motifs to translation initiation factor EIF4E3 function in Leishmania sp

Os tripanossomatídeos são organismos caracterizados pelo controle póstranscricional da expressão gênica, principalmente em nível de tradução. Na tradução em eucariotos, tem grande destaque o complexo eIF4F, sendo um de seus principais componentes o fator de iniciação da tradução eIF4E. Já foram descritos em tripanossomatídeos seis homólogos para o eIF4E, nomeados EIF4E1 a 6. Em um estudo com Leishmania amazonensis, focado no EIF4E3, percebeu-se que seu perfil de expressão se alterava rapidamente numa curva de crescimento, com este apresentando ao menos duas bandas. As mudanças observadas sugeriam modificações pós-traducionais do tipo fosforilação, algo posteriormente confirmado. Analisando-se a sequência do EIF4E3 de Leishmania, foi possível identificar a presença de possíveis sítios de fosforilação e de ligação a parceiros funcionais como homólogos do eIF4G, outro componente do complexo eIF4F, e da proteína de ligação á cauda poli-A (PABP). No presente estudo foi analisado o perfil de expressão e a capacidade de ligação a parceiros funcionais do EIF4E3 de Leishmania superexpresso em células transfectadas e no qual foram introduzidas mutações em motivos específicos. Os resultados mostraram um perfil de expressão de ao menos três bandas para o EIF4E3 de L. amazonensis e duas para L. infantum, com o sítio S75, presente apenas na primeira, sendo o responsável por esta diferença...