排序方式: 共有275条查询结果,搜索用时 15 毫秒
61.
Renato Milani Carmen V. Ferreira José M. Granjeiro Edgar J. Paredes‐Gamero Rodrigo A. Silva Giselle Z. Justo Helena B. Nader Eduardo Galembeck Maikel P. Peppelenbosch Hiroshi Aoyama Willian F. Zambuzzi 《Journal of cellular biochemistry》2010,109(5):957-966
Cell adhesion on surfaces is a fundamental process in the emerging biomaterials field and developmental events as well. However, the mechanisms regulating this biological process in osteoblasts are not fully understood. Reversible phosphorylation catalyzed by kinases is probably the most important regulatory mechanism in eukaryotes. Therefore, the goal of this study is to assess osteoblast adhesion through a molecular prism under a peptide array technology, revealing essential signaling proteins governing adhesion‐related events. First, we showed that there are main morphological changes on osteoblast shape during adhesion up to 3 h. Second, besides classical proteins activated upon integrin activation, our results showed a novel network involving signaling proteins such as Rap1A, PKA, PKC, and GSK3β during osteoblast adhesion on polystyrene. Third, these proteins were grouped in different signaling cascades including focal adhesion establishment, cytoskeleton rearrangement, and cell‐cycle arrest. We have thus provided evidence that a global phosphorylation screening is able to yield a systems‐oriented look at osteoblast adhesion, providing new insights for understanding of bone formation and improvement of cell–substratum interactions. Altogether, these statements are necessary means for further intervention and development of new approaches for the progress of tissue engineering. J. Cell. Biochem. 109: 957–966, 2010. © 2010 Wiley‐Liss, Inc. 相似文献
62.
RNA-mediated interference (RNAi) was employed to systematically inactivate the four subunits of complex II in the mitochondrial electron transport chain. Embryonic lethality was the predominant result of inactivating three subunits (ceSDHB, ceSDHC, and ceSDHD) when using the soaking method to inactivate RNA. The feeding method was employed to deliver dsRNA from the fourth subunit (ceSDHA) to wild-type, mev-1 (mutated in ceSDHC of complex II), and gas-1 animals (mutated in a complex I gene). Survival was reduced only in the mev-1 genetic background, and in an oxygen-dependent fashion. Collectively, these data provide further evidence that compromised complex II integrity can result in sensitivity to oxidative stress. 相似文献
63.
Summary Quantitative esterification of polyethylene glycol (PEG) 400 using oleic acid and Lipozyme was achieved in hexane. The effects of temperature, nature of acyl donor, substrate ratio, enzyme quantity and reaction time upon PEG esterification were examined. Nearly selective production of either PEG monooleate or PEG dioleate was achieved. Lipozyme was still 80% active after five reaction cycles. 相似文献
64.
Nielsen V Hurtado P Janzen DH Tamayo G Sittenfeld A 《Revista de biología tropical》2004,52(1):119-132
This study describes the results and collection practices for obtaining arthropod samples to be studied as potential sources of new medicines in a bioprospecting effort. From 1994 to 1998, 1800 arthropod samples of 6-10 g were collected in 21 sites of the Area de Conservaci6n Guancaste (A.C.G) in Northwestern Costa Rica. The samples corresponded to 642 species distributed in 21 orders and 95 families. Most of the collections were obtained in the rainy season and in the tropical rainforest and dry forest of the ACG. Samples were obtained from a diversity of arthropod orders: 49.72% of the samples collected corresponded to Lepidoptera, 15.75% to Coleoptera, 13.33% to Hymenoptera, 11.43% to Orthoptera, 6.75% to Hemiptera, 3.20% to Homoptera and 7.89% to other groups. Different life stages per arthropod species were obtained in most samples, 54.26% of them were adults, 19.90% corresponded to larvae, 6.46% to pupae, 6.12% to pre-pupae, 2.07% to nymphs and 3.74% to other stages. Other materials associated to insects like frass represented 11.20% of the samples collected. Several collecting methods were explored, based on the possibility of accessing the necessary amount of material causing the less impact. Most of the samples were obtained by manual collection (44.38%),. followed by insects breeding (25.73%), light traps (18.80%), different types of nets (10.52%) and other methods (0.16%). In general, collecting methods and practices excluded the use of solvents, mixing different species or life stages in the same bag, which might have introduced undesirable effects in the screening systems for new compounds. Based on the possibility of finding new chemicals in similar samples associated to one arthropod species, the collecting strategy included the generation of several samples from same species, separated according to differences in life stages, collecting sites, ecosystems. seasons, feeding materials or behavioral aspects. This strategy allowed the generation a larger number of samples submitted to bioassays in different areas of pharmaceutical research. 相似文献
65.
Curcumin inhibits formation of amyloid beta oligomers and fibrils, binds plaques, and reduces amyloid in vivo 总被引:2,自引:0,他引:2
Yang F Lim GP Begum AN Ubeda OJ Simmons MR Ambegaokar SS Chen PP Kayed R Glabe CG Frautschy SA Cole GM 《The Journal of biological chemistry》2005,280(7):5892-5901
Alzheimer's disease (AD) involves amyloid beta (Abeta) accumulation, oxidative damage, and inflammation, and risk is reduced with increased antioxidant and anti-inflammatory consumption. The phenolic yellow curry pigment curcumin has potent anti-inflammatory and antioxidant activities and can suppress oxidative damage, inflammation, cognitive deficits, and amyloid accumulation. Since the molecular structure of curcumin suggested potential Abeta binding, we investigated whether its efficacy in AD models could be explained by effects on Abeta aggregation. Under aggregating conditions in vitro, curcumin inhibited aggregation (IC(50) = 0.8 microM) as well as disaggregated fibrillar Abeta40 (IC(50) = 1 microM), indicating favorable stoichiometry for inhibition. Curcumin was a better Abeta40 aggregation inhibitor than ibuprofen and naproxen, and prevented Abeta42 oligomer formation and toxicity between 0.1 and 1.0 microM. Under EM, curcumin decreased dose dependently Abeta fibril formation beginning with 0.125 microM. The effects of curcumin did not depend on Abeta sequence but on fibril-related conformation. AD and Tg2576 mice brain sections incubated with curcumin revealed preferential labeling of amyloid plaques. In vivo studies showed that curcumin injected peripherally into aged Tg mice crossed the blood-brain barrier and bound plaques. When fed to aged Tg2576 mice with advanced amyloid accumulation, curcumin labeled plaques and reduced amyloid levels and plaque burden. Hence, curcumin directly binds small beta-amyloid species to block aggregation and fibril formation in vitro and in vivo. These data suggest that low dose curcumin effectively disaggregates Abeta as well as prevents fibril and oligomer formation, supporting the rationale for curcumin use in clinical trials preventing or treating AD. 相似文献
66.
Cerchiaro G Aquilano K Filomeni G Rotilio G Ciriolo MR Ferreira AM 《Journal of inorganic biochemistry》2005,99(7):1433-1440
Some copper(II) complexes with isatin (isa) or imine ligands derived from isatin were prepared, characterized by analytical and spectroscopic techniques, and had their biological activity toward proliferation of two different cell types verified. These complexes exhibit keto-enolic equilibria in aqueous solution, very dependent of pH, although isolated in the solid state in one defined form, and this type of equilibrium was previously verified to be crucial for their catalytic activity in the oxidation of carbohydrates, through intermediary generation of reactive oxygen species. Herein, biological studies carried out with tumor cells of different origin such as human neuroblastoma (SH-SY5Y) and promonocytic (U937) cells showed that these compounds exert different toxicity. In particular, while compounds [Cu(isaen)(H(2)O)]ClO(4).2H(2)O 2, [Cu(isahist)(H(2)O)](ClO(4))(2)4 and [Cu(isa)(2)]ClO(4)6 are not toxic for both cell lines at the concentrations used in this study, compounds [Cu(isapn)](ClO(4))(2)1, [Cu(isaepy)(2)](ClO(4))(2).2H(2)O 3 and [Cu(isami)(H(2)O)]ClO(4)5 are cytotoxic, with the compound 3 being the most effective. In these compounds, isaen, isahist, isapn, isaepy and isami stand for imine ligands prepared by condensation of ethylenediamine (en), histamine (hist), 1,3-diaminopropane (pn), 2-aminoethylpyridine (epy), and 8-aminoquinoline (ami) with isatin (isa). Cells treated with these compounds were committed to the apoptotic program as evidenced by cytofluorimetric analyses of cell cycle. Moreover, the toxicity of compound 5 was equivalent for both cell lines while the compound 1 was almost not toxic at 24h for SH-SY5Y cells where only an arrest in G1 phase was observed. Compound 3 was more efficient in inducing cell death and also in this case a striking effect on U937 cells (apoptotic cells 68% compared with 11% of SH-SY5Y) was observed. Therefore, the results indicated that their activity seems to be cell type specific. 相似文献
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68.
Giselle Villa Flor Brunoro Vitor Marcel Fa?a Marcelle Almeida Caminha André Teixeira da Silva Ferreira Monique Trugilho Kelly Cristina Gallan de Moura Jonas Perales Richard Hemmi Valente Rubem Figueiredo Sadok Menna-Barreto 《PLoS neglected tropical diseases》2016,10(8)
BackgroundThe obligate intracellular protozoan Trypanosoma cruzi is the causative agent of Chagas disease, a neglected illness affecting millions of people in Latin America that recently entered non-endemic countries through immigration, as a consequence of globalization. The chemotherapy for this disease is based mainly on benznidazole and nifurtimox, which are very efficient nitroderivatives against the acute stage but present limited efficacy during the chronic phase. Our group has been studying the trypanocidal effects of naturally occurring quinones and their derivatives, and naphthoimidazoles derived from β-lapachone N1, N2 and N3 were the most active. To assess the molecular mechanisms of action of these compounds, we applied proteomic techniques to analyze treated bloodstream trypomastigotes, which are the clinically relevant stage of the parasite.Conclusion/SignificanceOur results point to different modes of action for N1, N2 and N3, which indicate a great variety of metabolic pathways involved and allow for novel perspectives on the development of trypanocidal agents. 相似文献
69.
Paula D. B. Adamis Sergio C. Mannarino Cristiano J. Riger Giselle Duarte Ana Cruz Marcos D. Pereira Elis C. A. Eleutherio 《Biometals》2009,22(2):243-249
In Saccharomyces cerevisiae, accumulation of cadmium-glutathione complex in cytoplasm inhibits cadmium absorption, glutathione transferase 2 is required
for the formation of the complex and the vacuolar gamma-glutamyl transferase participates of the first step of glutathione
degradation. Here, we proposed that Lap4, a vacuolar amino peptidase, is involved in glutathione catabolism under cadmium
stress. Saccharomyces cerevisiae cells deficient in Lap4 absorbed almost 3-fold as much cadmium as the wild-type strain (wt), probably due to the lower rate
of cadmium-glutathione complex synthesis in the cytoplasm. In wt, but not in lap4 strain, the oxidized/reduced GSH ratio and the Gtt activity increased in response to cadmium, confirming that the mutant
is deficient in the synthesis of the complex probably because the degradation of vacuolar glutathione is impaired. Thus, under
cadmium stress, Lap4 and gamma-glutamyl transferase seem to work together to assure an efficient glutathione turnover stored
in the vacuole. 相似文献
70.
Paula Rêgo Bittencourt-Cunha Livia Silva-Cardoso Giselle Almeida de Oliveira José Roberto da Silva Alan Barbosa da Silveira George Eduardo Gabriel Kluck Michele Souza-Lima Katia Calp Gondim Marilvia Dansa-Petretsky Carlos Peres Silva Hatisaburo Masuda Mario Alberto Cardoso da Silva Neto Georgia Correa Atella 《Memórias do Instituto Oswaldo Cruz》2013,108(4):494-500
In this study, we describe the fate of fatty acids that are
incorporated from the lumen by the posterior midgut epithelium of
Rhodnius prolixus and the biosynthesis of lipids. We also
demonstrate that neutral lipids (NL) are transferred to the haemolymphatic
lipophorin (Lp) and that phospholipids remain in the tissue in which they are
organised into perimicrovillar membranes (PMMs). 3H-palmitic acid added at the
luminal side of isolated midguts of R. prolixus females was
readily absorbed and was used to synthesise phospholipids (80%) and NL (20%).
The highest incorporation of 3H-palmitic acid was on the first day after a blood
meal. The amounts of diacylglycerol (DG) and triacylglycerol synthesised by the
tissue decreased in the presence of Lp in the incubation medium. The metabolic
fates of 3H-lipids synthesised by the posterior midgut were followed and it was
observed that DG was the major lipid released to Lp particles. However, the
majority of phospholipids were not transferred to Lp, but remained in the
tissue. The phospholipids that were synthesised and accumulated in the posterior
midgut were found to be associated with Rhodnius luminal
contents as structural components of PMMs. 相似文献