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41.
Ribeiro-dos-Santos  Khayat AS Silva A Alencar DO Lobato J Luz L Pinheiro DG Varuzza L Assumpção M Assumpção P Santos S Zanette DL Silva WA Burbano R Darnet S 《PloS one》2010,5(10):e13205
Background
While microRNAs (miRNAs) play important roles in tissue differentiation and in maintaining basal physiology, little is known about the miRNA expression levels in stomach tissue. Alterations in the miRNA profile can lead to cell deregulation, which can induce neoplasia.Methodology/Principal Findings
A small RNA library of stomach tissue was sequenced using high-throughput SOLiD sequencing technology. We obtained 261,274 quality reads with perfect matches to the human miRnome, and 42% of known miRNAs were identified. Digital Gene Expression profiling (DGE) was performed based on read abundance and showed that fifteen miRNAs were highly expressed in gastric tissue. Subsequently, the expression of these miRNAs was validated in 10 healthy individuals by RT-PCR showed a significant correlation of 83.97% (P<0.05). Six miRNAs showed a low variable pattern of expression (miR-29b, miR-29c, miR-19b, miR-31, miR-148a, miR-451) and could be considered part of the expression pattern of the healthy gastric tissue.Conclusions/Significance
This study aimed to validate normal miRNA profiles of human gastric tissue to establish a reference profile for healthy individuals. Determining the regulatory processes acting in the stomach will be important in the fight against gastric cancer, which is the second-leading cause of cancer mortality worldwide. 相似文献42.
A molecular dissection of the glycoprotein hormone receptors 总被引:11,自引:0,他引:11
In glycoprotein hormone receptors, a subfamily of rhodopsin-like G protein-coupled receptors, the recognition and activation steps are carried out by separate domains of the proteins. Specificity of recognition of the hormones thyrotropin (TSH), lutropin (LH), human chorionic gonadotropin (hCG) and follitropin (FSH) involves leucine-rich repeats (LRRs) present in an N-terminal ectodomain, and can be associated with a limited number of residues at key positions of the LRRs. The mechanism by which binding of the hormones results in activation is proposed to involve switching of the ectodomain from a tethered inverse agonist to a full agonist of the serpentine, rhodopsin-like region of the receptor. Unexpectedly, the picture is complicated by the observation that promiscuous activation of one of the receptors (FSHr) by hCG or TSH can result from activating mutations affecting the serpentine region of the receptors. 相似文献
43.
Background
Core histone genes are periodically expressed along the cell cycle and peak during S phase. Core histone gene expression is deeply evolutionarily conserved from the yeast Saccharomyces cerevisiae to human. 相似文献44.
Sara L. Zeigler Maile C. Neel Leonardo Oliveira Becky E. Raboy William F. Fagan 《Biodiversity and Conservation》2011,20(12):2779-2796
Functional connectivity is known to have an important, positive influence on species persistence. Measurements of functional
connectivity traditionally focus on structural attributes of landscapes such as the distance and matrix type between habitat
patches as well as on how species interact with those structural attributes. However, we propose that the social behavior
of a species, through conspecific and heterospecific attraction, will also impact connectivity by changing how dispersers
move with respect to each other and occupied patches. We analyzed functional connectivity patterns using circuit and graph
theory for golden-headed lion tamarins (Leontopithecus chrysomelas) in Brazil under three scenarios. In the first scenario, we looked at connectivity without the effects of attraction under
varying maximum dispersal distance and ecological movement cost thresholds. In the second scenario, we allowed dispersers
to travel over more hostile matrix than they normally would to reach an occupied patch. In the final scenario, we allowed
dispersers to move only to occupied patches. We found that, according to the first scenario, range-wide functional landscape
connectivity for golden-headed lion tamarins is low at realistic maximum dispersal distance and movement cost thresholds.
Incorporating the effects of conspecific or heterospecific attraction would increase functional connectivity, in the case
of scenario two, or decrease functional connectivity, in the case of scenario three. Because conspecific/heterospecific attraction
can have an impact on movement for some species, this factor should be incorporated in assessments of functional connectivity
patterns for social species and others where patch occupancy is likely to influence the movements of dispersers. 相似文献
45.
de Barros CM Andrade LR Allodi S Viskov C Mourier PA Cavalcante MC Straus AH Takahashi HK Pomin VH Carvalho VF Martins MA Pavão MS 《The Journal of biological chemistry》2007,282(3):1615-1626
The hemolymph of ascidians (Chordata-Tunicata) contains different types of hemocytes embedded in a liquid plasma. In the present study, heparin and a sulfated heteropolysaccharide were purified from the hemolymph of the ascidian Styela plicata. The heteropolysaccharide occurs free in the plasma, is composed of glucose ( approximately 60%) and galactose ( approximately 40%), and is highly sulfated. Heparin, on the other hand, occurs in the hemocytes, and high performance liquid chromatography of the products formed by degradation with specific lyases revealed that it is composed mainly by the disaccharides DeltaUA(2SO(4))-1-->4-beta-d-GlcN(SO(4)) (39.7%) and DeltaUA(2SO(4))-1-->4-beta-d-GlcN(SO(4))(6SO(4)) (38.2%). Small amounts of the 3-O-sulfated disaccharides DeltaUA(2SO(4))-1-->4-beta-d-GlcN(SO(4))(3SO(4)) (9.8%) and DeltaUA(2SO(4))-1-->4-beta-d-GlcN(SO(4))(3SO(4))(6SO(4)) (3.8%) were also detected. These 3-O-sulfated disaccharides were demonstrated to be essential for the binding of the hemocyte heparin to antithrombin III. Electron microscopy techniques were used to characterize the ultrastructure of the hemocytes and to localize heparin and histamine in these cells. At least five cell types were recognized and classified as univacuolated and multivacuolated cells, amebocytes, hemoblasts, and granulocytes. Immunocytochemistry showed that heparin and histamine co-localize in intracellular granules of only one type of hemocyte, the granulocyte. These results show for the first time that in ascidians, a sulfated galactoglucan circulates free in the plasma, and heparin occurs as an intracellular product of a circulating basophil-like cell. 相似文献
46.
D'Addio F Riella LV Mfarrej BG Chabtini L Adams LT Yeung M Yagita H Azuma M Sayegh MH Guleria I 《Journal of immunology (Baltimore, Md. : 1950)》2011,187(9):4530-4541
Fetomaternal tolerance has been shown to depend both on regulatory T cells (Tregs) and negative signals from the PD1-PDL1 costimulatory pathway. More recently, IL-17-producing T cells (Th17) have been recognized as a barrier in inducing tolerance in transplantation. In this study, we investigate the mechanisms of PDL1-mediated regulation of fetomaternal tolerance using an alloantigen-specific CD4(+) TCR transgenic mouse model system (ABM-tg mouse). PDL1 blockade led to an increase in embryo resorption and a reduction in litter size. This was associated with a decrease in Tregs, leading to a lower Treg/effector T cell ratio. Moreover, PDL1 blockade inhibited Ag-specific alloreactive T cell apoptosis and induced apoptosis of Tregs and a shift toward higher frequency of Th17 cells, breaking fetomaternal tolerance. These Th17 cells arose predominantly from CD4(+)Foxp3(-) cells, rather than from conversion of Tregs. Locally in the placenta, similar decrease in regulatory and apoptotic markers was observed by real-time PCR. Neutralization of IL-17 abrogated the anti-PDL1 effect on fetal survival rate and restored Treg numbers. Finally, the adoptive transfer of Tregs was also able to improve fetal survival in the setting of PDL1 blockade. This is to our knowledge the first report using an alloantigen-specific model that establishes a link between PDL1, Th17 cells, and fetomaternal tolerance. 相似文献
47.
48.
49.
Priscila P. Santos Fernando Oliveira Vanessa C. M. P. Ferreira Bertha F. Polegato Meliza G. Roscani Ana Angelica Fernandes Pamela Modesto Bruna P. M. Rafacho Silmeia G. Zanati Annarita Di Lorenzo Luiz S. Matsubara Sergio A. R. Paiva Leonardo A. M. Zornoff Marcos F. Minicucci Paula S. Azevedo 《PloS one》2014,9(12)
Background/Aims
Experimental and clinical studies have shown the direct toxic effects of cigarette smoke (CS) on the myocardium, independent of vascular effects. However, the underlying mechanisms are not well known.Methods
Wistar rats were allocated to control (C) and cigarette smoke (CS) groups. CS rats were exposed to cigarette smoke for 2 months.Results
After that morphometric, functional and biochemical parameters were measured. The echocardiographic study showed enlargement of the left atria, increase in the left ventricular systolic volume and reduced systolic function. Within the cardiac metabolism, exposure to CS decreased beta hydroxy acyl coenzyme A dehydrogenases and citrate synthases and increased lactate dehydrogenases. Peroxisome proliferator-activated receptor alpha (PPARα) and peroxisome proliferator-activated receptor gamma coactivator 1 alpha (PGC-1α) were expressed similarly in both groups. CS increased serum lipids and myocardial triacylglycerols (TGs). These data suggest that impairment in fatty acid oxidation and the accumulation of cardiac lipids characterize lipotoxicity. CS group exhibited increased oxidative stress and decreased antioxidant defense. Finally, the myocyte cross-sectional area and active Caspase 3 were increased in the CS group.Conclusion
The cardiac remodeling that was observed in the CS exposure model may be explained by abnormalities in energy metabolism, including lipotoxicity and oxidative stress. 相似文献50.
Chiappetta A Michelotti V Fambrini M Bruno L Salvini M Petrarulo M Azmi A Van Onckelen H Pugliesi C Bitonti MB 《Planta》2006,223(5):917-931