Hepatitis C Virus NS2 Protein Inhibits DNA Damage Pathway by Sequestering p53 to the Cytoplasm

Chronic hepatitis C virus (HCV) infection is an important cause of morbidity and mortality globally, and often leads to end-stage liver disease. The DNA damage checkpoint pathway induces cell cycle arrest for repairing DNA in response to DNA damage. HCV infection has been involved in this pathway. In this study, we assess the effects of HCV NS2 on DNA damage checkpoint pathway. We have observed that HCV NS2 induces ataxia-telangiectasia mutated checkpoint pathway by inducing Chk2, however, fails to activate the subsequent downstream pathway. Further study suggested that p53 is retained in the cytoplasm of HCV NS2 expressing cells, and p21 expression is not enhanced. We further observed that HCV NS2 expressing cells induce cyclin E expression and promote cell growth. Together these results suggested that HCV NS2 inhibits DNA damage response by altering the localization of p53, and may play a role in the pathogenesis of HCV infection. © 2013 Bitter et al.

A metabolic pathway assembled by enzyme selection may support herbivory of leaf-cutter ants on plant starch

Mutualistic associations shape the evolution in different organism groups. The association between the leaf-cutter ant Atta sexdens and the basidiomycete fungus Leucoagaricus gongylophorus has enabled them to degrade starch from plant material generating glucose, which is a major food source for both mutualists. Starch degradation is promoted by enzymes contained in the fecal fluid that ants deposit on the fungus culture in cut leaves inside the nests. To understand the dynamics of starch degradation in ant nests, we purified and characterized starch degrading enzymes from the ant fecal fluid and from laboratory cultures of L. gongylophorus and found that the ants intestine positively selects fungal α-amylase and a maltase likely produced by the ants, as a negative selection is imposed to fungal maltase and ant α-amylases. Selected enzymes are more resistant to catabolic repression by glucose and proposed to structure a metabolic pathway in which the fungal α-amylase initiates starch catalysis to generate byproducts which are sequentially degraded by the maltase to produce glucose. The pathway is responsible for effective degradation of starch and proposed to represent a major evolutionary innovation enabling efficient starch assimilation from plant material by leaf-cutters. © 2013 Elsevier Ltd.

Orientaciones para políticas futuras complementarias al Plan de Acción Regional para América Latina y el Caribe en relación con el Año Internacional de la Juventud = Guidelines for future policies to complement the Regional Plan of Action for Latin America and the Caribbean for the International Youth Year

Incluye Bibliografía

Triiodothyronine Increases mRNA and Protein Leptin Levels in Short Time in 3T3-L1 Adipocytes by PI3K Pathway Activation

The present study aimed to examine the effects of thyroid hormone (TH), more precisely triiodothyronine (T3), on the modulation of leptin mRNA expression and the involvement of the phosphatidyl inositol 3 kinase (PI3K) signaling pathway in adipocytes, 3T3-L1, cell culture. We examined the involvement of this pathway in mediating TH effects by treating 3T3-L1 adipocytes with physiological (P=10nM) or supraphysiological (SI=100 nM) T3 dose during one hour (short time), in the absence or the presence of PI3K inhibitor (LY294002). The absence of any treatment was considered the control group (C). RT-qPCR was used for mRNA expression analyzes. For data analyzes ANOVA complemented with Tukey's test was used at 5% significance. T3 increased leptin mRNA expression in P (2.26 ± 0.36, p< 0.001), SI (1.99 ±0.22, p< 0.01) compared to C group (1± 0.18). This increase was completely abrogated by LY294002 in P (1.31±0.05, p< 0.001) and SI (1.33±0.31, p< 0.05). Western blotting confirmed these results at protein level, indicating the PI3K pathway dependency. To examine whether leptin is directly induced by T3, we used the translation inhibitor cycloheximide (CHX). In P, the presence of CHX maintained the levels mRNA leptin, but was completely abrogated in SI (1.14±0.09, p> 0.001). These results demonstrate that the activation of the PI3K signaling pathway has a role in TH-mediated direct and indirect leptin gene expression in 3T3-L1 adipocytes. © 2013 Oliveira et al.

Alteration in cellular viability, pro-inflammatory cytokines and nitric oxide production in nephrotoxicity generation by Amphotericin B: Involvement of PKA pathway signaling

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Pesquisa de mutação do gene predito da lectina ligante de manose em cães: comparação entre dois alvos para diagnóstico molecular de leishmaniose visceral canina

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Investigação do polimorfismo do exon - 1 do gene MBL (Mannose-Binding Lectin) em pacientes portadores de tuberculose

A lectina ligante de manose (MBL) é uma proteína considerada de fase aguda com importante papel na primeira linha de defesa do sistema imune inato, cujos níveis séricos são determinados geneticamente. A MBL ativa a via da lectina do complemento, além de mediar a opsonização e fagocitose de microrganismos. Vários estudos associam os níveis séricos de MBL à suscetibilidade ou resistência a agentes infecciosos entre eles o Mycobacterium tuberculosis, agente causador da tuberculose humana. Neste estudo, com o objetivo de avaliar a ocorrência de uma possível associação entre os polimorfismos e a tuberculose, avaliamos as freqüências das mutações no éxon 1 do gene MBL em um grupo de 167 pacientes com tuberculose, subdivididos em 3 grupos: pacientes com tuberculose pulmonar, pacientes com tuberculose extrapulmonar, pacientes com tuberculose multirresistente a drogas, e grupo controle com 159 profissionais da saúde, negativos para tuberculose. A identificação dos alelos MBL *A, *B, *C e *D foi realizada por meio da reação em cadeia da polimerase, utilizando seqüências de iniciadores específicos e posterior digestão enzimática. As análises das freqüências alélicas e genotípicas do éxon 1 não mostraram qualquer diferença significativa entre pacientes com tuberculose e grupo controle (p>0,05). Não foram observadas associações significativas entre os grupos de tuberculose pulmonar, extrapulmonar e tuberculose multirresistente a drogas, quando relacionados entre si e ao grupo controle. Os dados obtidos em nosso estudo não demonstraram evidencias de qualquer influência das variações do éxon 1 do gene MBL na tuberculose ativa, sugerindo que os polimorfismos nessa região do gene não tem nenhuma influencia na susceptibilidade à tuberculose.

Effect of soybean yoghurt supplemented with isoflavones on the haemolytic activity of serum complement in mice with experimental lung metastasis of murine mammary and pulmonary adenocarcinoma

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

The expressibility of modality in representational complement clauses in Brazilian Portuguese

This paper deals with the (im)possibility of expressing a variety of modal categories within the context of the layering approach to complementation in Functional Discourse Grammar (FDG).Our hypothesis is that modal expressions in complement clauses only pertain to operator or modifier classes of the highest layer relevant for that type of embedded construction and for all lower levels. In order to test this hypothesis, occurrences of complement clauses in two databases of spoken Brazilian Portuguese are analyzed. The investigation of this hypothesis is restricted to representational complement clauses.

Métodos para identificação de moléculas com atividade herbicida com ênfase na rota de síntese de carotenóides

Pós-graduação em Agronomia (Proteção de Plantas) - FCA