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991.
Morphological changes and EGF expression in the granular convoluted tubule cells of submandibular glands of Trypanosoma cruzi infected rats 总被引:1,自引:0,他引:1
Moreira A Napimoga MH Benatti BB Silva GA Rocha-Rodrigues DB Clemente-Napimoga JT Vieira GA Alves JB 《Tissue & cell》2008,40(4):293-298
We have previously demonstrated in rats that Chagas' disease affects the salivary glands, by promoting an enlargement of the submandibular gland. In order to further investigate possible functional alterations on infected submandibular glands, the objective of the present study was to analyze epidermal growth factor (EGF) expression on rat submandibular glands during Trypanosoma cruzi infection. Results demonstrated that infected rats presented lower levels of testosterone, and morphological changes in the granular convoluted tubule (GCT) cells of the submandibular glands, along with acinar enlargement and delayed ductal maturation at the developing granular ducts. Immunohistochemistry analysis additionally showed that only few cells immunolabelled with anti-EGF on infected rats during the acute phase of Chagas' disease, while after 64 and 90 days (chronic phase) of infection, EGF expression was similar to non-infected rats. The present findings suggest that at the acute phase of Chagas' disease, lower levels of testosterone may lead to a delayed maturation of GCT, which positively correlates with decreased EGF production by submandibular glands cells. 相似文献
992.
Prion protein complexed to N2a cellular RNAs through its N-terminal domain forms aggregates and is toxic to murine neuroblastoma cells 总被引:1,自引:0,他引:1
Gomes MP Millen TA Ferreira PS e Silva NL Vieira TC Almeida MS Silva JL Cordeiro Y 《The Journal of biological chemistry》2008,283(28):19616-19625
Conversion of the cellular prion protein (PrP(C)) into its altered conformation, PrP(Sc), is believed to be the major cause of prion diseases. Although PrP is the only identified agent for these diseases, there is increasing evidence that other molecules can modulate the conversion. We have found that interaction of PrP with double-stranded DNA leads to a protein with higher beta-sheet content and characteristics similar to those of PrP(Sc). RNA molecules can also interact with PrP and potentially modulate PrP(C) to PrP(Sc) conversion or even bind differentially to both PrP isoforms. Here, we investigated the interaction of recombinant murine PrP with synthetic RNA sequences and with total RNA extracted from cultured neuroblastoma cells (N2aRNA). We found that PrP interacts with N2aRNA with nanomolar affinity, aggregates upon this interaction, and forms species partially resistant to proteolysis. RNA does not bind to N-terminal deletion mutants of PrP, indicating that the N-terminal region is important for this process. Cell viability assays showed that only the N2aRNA extract induces PrP-RNA aggregates that can alter the homeostasis of cultured cells. Small RNAs bound to PrP give rise to nontoxic small oligomers. Nuclear magnetic resonance measurements of the PrP-RNA complex revealed structural changes in PrP, but most of its native fold is maintained. These results indicate that there is selectivity in the species generated by interaction with different molecules of RNA. The catalytic effect of RNA on the PrP(C)-->PrP(Sc) conversion depends on the RNA sequence, and small RNA molecules may exert a protective effect. 相似文献
993.
Edith Laugier Lionel Tarrago Christina Vieira Dos Santos Françoise Eymery Michel Havaux Pascal Rey 《The Plant journal : for cell and molecular biology》2010,61(2):271-282
Methionine oxidation to methionine sulfoxide (MetSO) is reversed by two types of methionine sulfoxide reductases (MSRs), A and B, specific to MetSO S‐ and R‐diastereomers, respectively. Two MSRB isoforms, MSRB1 and MSRB2, are present in chloroplasts of Arabidopsis thaliana. To assess their physiological role, we characterized Arabidopsis mutants knockout for the expression of MSRB1, MSRB2 or both genes. Measurements of MSR activity in leaf extracts revealed that the two plastidial MSRB enzymes account for the major part of leaf peptide MSR capacity. Under standard conditions of light and temperature, plants lacking one or both plastidial MSRBs do not exhibit any phenotype, regarding growth and development. In contrast, we observed that the concomitant absence of both proteins results in a reduced growth for plants cultivated under high light or low temperature. In contrast, double mutant lines restored for MSRB2 expression display no phenotype. Under environmental constraints, the MetSO level in leaf proteins is higher in plants lacking both plastidial MSRBs than in Wt plants. The absence of plastidial MSRBs is associated with an increased chlorophyll a/b ratio, a reduced content of Lhca1 and Lhcb1 proteins and an impaired photosynthetic performance. Finally, we show that MSRBs are able to use as substrates, oxidized cpSRP43 and cpSRP54, the two main components involved in the targeting of Lhc proteins to the thylakoids. We propose that plastidial MSRBs fulfil an essential function in maintaining vegetative growth of plants during environmental constraints, through a role in the preservation of photosynthetic antennae. 相似文献
994.
Claudia Trigo Pedroso Moraes Danielle Bruna Leal Oliveira Angelica Cristine Almeida Campos Patricia Alves Bosso Hildener Nogueira Lima Klaus Eberhard Stewien Alfredo Elias Gilio Sandra Elisabete Vieira Viviane Fongaro Botosso Edison Luiz Durigon 《Memórias do Instituto Oswaldo Cruz》2015,110(1):138-141
Human respiratory syncytial virus (HRSV) is an important respiratory pathogens among
children between zero-five years old. Host immunity and viral genetic variability are
important factors that can make vaccine production difficult. In this work,
differences between biological clones of HRSV were detected in clinical samples in
the absence and presence of serum collected from children in the convalescent phase
of the illness and from their biological mothers. Viral clones were selected by
plaque assay in the absence and presence of serum and nucleotide sequences of the G2
and F2 genes of HRSV biological clones were compared. One non-synonymous mutation was
found in the F gene (Ile5Asn) in one clone of an HRSV-B sample and one non-synonymous
mutation was found in the G gene (Ser291Pro) in four clones of the same HRSV-B
sample. Only one of these clones was obtained after treatment with the child''s serum.
In addition, some synonymous mutations were determined in two clones of the HRSV-A
samples. In conclusion, it is possible that minor sequences could be selected by host
antibodies contributing to the HRSV evolutionary process, hampering the development
of an effective vaccine, since we verify the same codon alteration in absence and
presence of human sera in individual clones of BR-85 sample. 相似文献
995.
996.
997.
R. Fortes-Silva I.E. Oliveira V.P. Vieira E.U. Winkaler B. Guerra-Santos R.B. Cerqueira 《Biological Rhythm Research》2016,47(2):183-190
This study aimed to assess the daily rhythms of locomotor activity and to quantify bacteria populations in the tambaqui digestive tract during light and dark periods. Photoelectric cells and a recording computational system were used to quantify the locomotor activity, and the existing Gram-positive and Gram-negative bacteria populations were evaluating during the daytime and night-time periods. The results showed a typical pattern for nocturnal locomotor activity (91%), and lower percentages of Gram-positive 6?×?103, 24% and Gram-negative cocci (approximately 38%) were observed during the same periods compared with the diurnal period (76 and 62%, respectively). Additionally, lower percentages of Gram-positive (42%) and Gram-negative (44%) Bacillus were observed during the same periods compared with the diurnal period (29?×?106 CFU/g, 58% and 23?×?106 CFU/g (56%), respectively). These data should be considered when animals are subjected to high stress loads for more appropriate management strategies and collaborating with future studies of what is the best schedule to vaccinate or provide probiotics to fish. 相似文献
998.
Luciana Miato Gon?alves Silva Camila Aparecida Alves da Silva Aline da Silva Rodolfo Paula Vieira Raquel Agnelli Mesquita-Ferrari José Carlos Cogo Stella Regina Zamuner 《PloS one》2016,11(4)
BackgroundSnakebites is a neglected disease and in Brazil is considered a serious health problem, with the majority of the snakebites caused by the genus Bothrops. Antivenom therapy and other first-aid treatments do not reverse local myonecrose which is the main sequel caused by the envenomation. Several studies have shown the effectiveness of low level laser (LLL) therapy in reducing local myonecrosis induced by Bothropic venoms, however the mechanism involved in this effect is unknown. In this in vitro study, we aimed to analyze the effect of LLL irradiation against cytotoxicity induced by Bothrops jararacussu venom on myoblast C2C12 cells.MethodologyC2C12 were utilized as a model target and were incubated with B. jararacussu venom (12.5 μg/mL) and immediately irradiated with LLL at wavelength of red 685 nm or infrared 830 nm with energy density of 2.0, 4.6 and 7.0 J/cm2. Effects of LLL on cellular responses of venom-induced cytotoxicity were examined, including cell viability, measurement of cell damage and intra and extracellular ATP levels, expression of myogenic regulatory factors, as well as cellular differentiation.ResultsIn non-irradiated cells, the venom caused a decrease in cell viability and a massive release of LDH and CK levels indicating myonecrosis. Infrared and red laser at all energy densities were able to considerably decrease venom-induced cytotoxicity. Laser irradiation induced myoblasts to differentiate into myotubes and this effect was accompanied by up regulation of MyoD and specially myogenin. Moreover, LLL was able to reduce the extracellular while increased the intracellular ATP content after venom exposure. In addition, no difference in the intensity of cytotoxicity was shown by non-irradiated and irradiated venom.ConclusionLLL irradiation caused a protective effect on C2C12 cells against the cytotoxicity caused by B. jararacussu venom and promotes differentiation of these cells by up regulation of myogenic factors. A modulatory effect of ATP synthesis may be suggested as a possible mechanism mediating cytoprotection observed under laser irradiation. 相似文献
999.
Erratum: GLUT4 translocation is not impaired after acute exercise in skeletal muscle of women with obesity and polycystic ovary syndrome 下载免费PDF全文
Wagner Silva Dantas José Antonio Miguel Marcondes Samuel Katsuyuki Shinjo Luiz Augusto Perandini Vanessa Olzon Zambelli Willian Das Neves Cristiano Roberto Grimaldi Barcellos Michele Patrocínio Rocha Viviane Dos Reis Vieira Yance Renato Tavares Dos Santos Pereira Igor Hisashi Murai Ana Lucia De Sá Pinto Hamilton Roschel Bruno Gualano 《Obesity (Silver Spring, Md.)》2016,24(9):2012-2012
1000.