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1.
Biomed Pharmacother ; 130: 110551, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32768881

RESUMO

BACKGROUND: Prostate cancer (PCa) is the most diagnosed invasive cancer and a leading cause of death in men in western countries. Most patients initially respond to androgen deprivation but finally develop hormone-refractory disease, which results in advanced clinical failure and death. Since hormone-refractory disease is highly radiotherapy and chemotherapy resistant, increasing interest has been placed on finding novel therapies for this advanced type of Pca. PURPOSE: The potential cytotoxic effects of the crude extract and fractions obtained from the leaves of Cecropia pachystachya Trécul on different human cancer cell lines were investigated. Additionally, the mechanism of cell death induction of the most active sample (triterpene-enriched fraction, TEF) on the human hormone-refractory prostate PC3 cell line was examined. METHODS: Sulforhodamine B assay was used to measure the viability of human tumor and non-tumor cell lines. To elucidate the mechanism of PC3 cells death induced by TEF, different methodological approaches were used: cell cycle analysis and annexin V/PI staining, nuclear morphological analysis, and senescence-associated-ß-galactosidase assay. Moreover, the mitochondrial membrane potential was measured, and the long-term effects of TEF on PC3 cells were evaluated. RESULTS: TEF exerted cytotoxic effects on PC3 cells but not on human non-tumor cells. The analysis of nuclear morphology of PC3 cells treated with TEF increased the number of cells with large and regular nuclei suggesting senescence induction, which was supported by ß-galactosidase overexpression. Regarding PC3 cells cycle, TEF reduced the number of cells in G1 phase and increased that in sub G0/G1. Apoptosis was not involved in PC3 cell death. However, there was a decrease in mitochondrial membrane potential without the participation of reactive oxygen species (ROS) in the cytotoxic effects detected. Furthermore, there was a decrease in the number of viable cells able to duplicate after long-term TEF treatment. CONCLUSIONS: The results showed the in vitro cytotoxic potential of the triterpene-enriched fraction obtained from the leaves of C. pachystachya on human prostate cancer PC3 cell line.


Assuntos
Antineoplásicos Fitogênicos/farmacologia , Cecropia/química , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Neoplasias da Próstata/tratamento farmacológico , Triterpenos/farmacologia , Apoptose/efeitos dos fármacos , Pontos de Checagem do Ciclo Celular/efeitos dos fármacos , Morte Celular/efeitos dos fármacos , Núcleo Celular/efeitos dos fármacos , Núcleo Celular/ultraestrutura , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Masculino , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Células PC-3 , Extratos Vegetais/farmacologia , Folhas de Planta/química , Espécies Reativas de Oxigênio/metabolismo
2.
Mol Biol Rep ; 47(8): 6043-6051, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32700127

RESUMO

Centaurea bruguierana, of the Asteraceae family, has a long history of use in traditional medicines for the treatment of various ailments. However, the anticancer activity and underlying mechanisms have not yet been assessed. The C. bruguierana was extracted with methanol and fractionated into four different fractions. Different cancer cells and one non-cancerous were used to examine the cytotoxic effects of these fractions using MTT assay. The most potent fraction, C. bruguierana ethyl acetate fraction (CB EtOAc), was explored for its effects on cell cycle progression and apoptosis induction by Hoechst staining and annexin V-PI double staining in MCF-7 cells. The expression of apoptosis-related genes was quantified by RT-PCR. Of all fractions, CB EtOAc was found to have the strongest antiproliferative activity (IC50 = 10 µg/mL) against MCF-7 cells. The antiproliferative activity of the CB EtOAc fraction against MCF-7 was correlated with arrested of cell cycle in the G1 phase, nuclear fragmentation, and the exposure of phosphatidylserine. The induction of apoptosis by CB EtOAc in MCF-7 cells was also associated with an increase in the Bax/Bcl-2 ratio and higher expression of caspases. Overall, our results demonstrated that CB EtOAc showed apoptosis-inducing effects, suggesting that C. bruguierana may be a promising source for a novel chemotherapeutic agents for the treatment of breast cancer.


Assuntos
Antineoplásicos Fitogênicos/isolamento & purificação , Neoplasias da Mama/patologia , Centaurea/química , Extratos Vegetais/farmacologia , 1-Butanol , Células A549 , Acetatos , Animais , Antineoplásicos Fitogênicos/farmacologia , Apoptose/efeitos dos fármacos , Proteínas Reguladoras de Apoptose/biossíntese , Proteínas Reguladoras de Apoptose/genética , Pontos de Checagem do Ciclo Celular/efeitos dos fármacos , Divisão Celular/efeitos dos fármacos , Núcleo Celular/efeitos dos fármacos , Núcleo Celular/ultraestrutura , Clorofórmio , Ensaios de Seleção de Medicamentos Antitumorais , Feminino , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Células Hep G2 , Células Endoteliais da Veia Umbilical Humana , Humanos , Concentração Inibidora 50 , Células MCF-7 , Metanol , Proteínas de Neoplasias/biossíntese , Proteínas de Neoplasias/genética , Componentes Aéreos da Planta/química , Solventes
3.
J Nat Prod ; 83(6): 1909-1918, 2020 06 26.
Artigo em Inglês | MEDLINE | ID: mdl-32496057

RESUMO

The need for effective candidates as cytotoxic drugs that at the same time challenge cancer multidrug resistance encouraged a search for these in plants of central Argentina. Bioassay-guided fractionation of the cytotoxic extract from Dimerostemma aspilioides led to the isolation of the germacranolide tomenphantin A (1), along with three new analogues (2-4). These efficiently inhibited the proliferation of the leukemia cell lines K562 and CCRF-CEM and their resistant variants, Lucena 1 and CEM/ADR5000, respectively, with IC50 values ranging from 0.40 to 7.7 µM. The structures and relative configurations of compounds 1-4 were elucidated by analysis of the spectroscopic data, in particular NMR spectroscopy. The most active among these was compound 1 (IC50 = 0.40-5.1 µM), and, therefore, this was selected as a model for a mechanistic study, which revealed that its antiproliferative effect was mediated by cell cycle arrest in the G2/M phase followed by apoptosis. The activity of compound 1 was selective, given the absence of cytotoxicity toward peripheral blood mononuclear cells. The results show the potential of these compounds, and in particular of compound 1, as leads for the development of drug candidates to fight sensitive and resistant leukemia cells.


Assuntos
Antineoplásicos Fitogênicos/farmacologia , Lactonas/farmacologia , Sesquiterpenos de Germacrano/química , Sesquiterpenos de Germacrano/farmacologia , Antineoplásicos Fitogênicos/química , Apoptose/efeitos dos fármacos , Pontos de Checagem do Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Núcleo Celular/efeitos dos fármacos , Núcleo Celular/ultraestrutura , Proliferação de Células/efeitos dos fármacos , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Lactonas/química , Espectroscopia de Ressonância Magnética , Estrutura Molecular , Monócitos/efeitos dos fármacos , Componentes Aéreos da Planta/química , Extratos Vegetais/química
4.
Plant Cell ; 32(4): 1270-1284, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32086364

RESUMO

Male and female gametophytes are generated from micro- or megaspore mother cells through consecutive meiotic and mitotic cell divisions. Defects in these divisions often result in gametophytic lethality. Gametophytic lethality was also reported when genes encoding ribosome-related proteins were mutated. Although numerous ribosomal proteins (RPs) have been identified in plants based on homology with their yeast and metazoan counterparts, how RPs are regulated, e.g., through dynamic subcellular targeting, is unknown. We report here that an Arabidopsis (Arabidopsis thaliana) importin ß, KETCH1 (karyopherin enabling the transport of the cytoplasmic HYL1), is critical for gametogenesis. Karyopherins are molecular chaperones mediating nucleocytoplasmic protein transport. However, the role of KETCH1 during gametogenesis is independent of HYPONASTIC LEAVES 1 (HYL1), a previously reported KETCH1 cargo. Instead, KETCH1 interacts with several RPs and is critical for the nuclear accumulation of RPL27a, whose mutations caused similar gametophytic defects. We further showed that knocking down KETCH1 caused reduced ribosome biogenesis and translational capacity, which may trigger the arrest of mitotic cell cycle progression and lead to gametophytic lethality.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/crescimento & desenvolvimento , Arabidopsis/metabolismo , Núcleo Celular/metabolismo , Gametogênese Vegetal , Carioferinas/metabolismo , Proteínas Ribossômicas/metabolismo , Arabidopsis/genética , Arabidopsis/ultraestrutura , Pontos de Checagem do Ciclo Celular , Núcleo Celular/ultraestrutura , Regulação para Baixo , Regulação da Expressão Gênica de Plantas , Mutação com Perda de Função/genética , Óvulo Vegetal/metabolismo , Óvulo Vegetal/ultraestrutura , Pólen/crescimento & desenvolvimento , Pólen/ultraestrutura , Ligação Proteica , Biossíntese de Proteínas , Proteínas de Ligação a RNA/metabolismo , Ribossomos/metabolismo , Sementes/metabolismo , Sementes/ultraestrutura
5.
Plant Reprod ; 32(1): 39-43, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30671645

RESUMO

Pollen represents the male sexual lineage in flowering plants. At maturity, pollen grains are composed of a companion vegetative cell with embedded sperm. During pollen development, these two cell types acquire vastly differing cell fates. Underlying this differential fate acquisition is dramatic reconfiguration of pollen chromatin that is highly evident at a cytological level. The precise link between histone mark deposition and fate acquisition remains largely unexplored, which in part has been hindered by the difficulty in working with pollen in model plant species like Arabidopsis. Here, we describe a simple and robust protocol to isolate Arabidopsis pollen nuclei and immunostain for histone marks. Plant growth aside, the protocol can be performed over 2 days with few Arabidopsis plants, thus allowing multiple genotypes to be analysed in parallel. We also describe a method to de-mask epitopes through antigen retrieval, which vastly improves the signal for antibodies that target heterochromatic histone marks.


Assuntos
Arabidopsis/ultraestrutura , Núcleo Celular/ultraestrutura , Pólen/ultraestrutura , Coloração e Rotulagem/métodos , Antígenos de Plantas/análise , Antígenos de Plantas/imunologia , Histonas/análise , Histonas/imunologia , Imuno-Histoquímica
6.
Biosci Biotechnol Biochem ; 83(4): 666-674, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30585123

RESUMO

Asparagus (Asparagus officinalis) has several traits that make it a useful model for cytogenetic studies, however, few studies of the meiosis process have been made in asparagus. Here, we present in detail an atlas of male meiosis in asparagus, from preleptotene to telophase II. The meiosis process in asparagus is largely similar to those of the well-characterized model plants Arabidopsis thaliana, Zea mays, and Oryza sativa. However, most asparagus prophase I meiotic chromosomes show a strongly aggregated morphology, and this phenotype persists through the pachytene stage, highlighting a property in the control of chromosome migration and distribution in asparagus. Further, we observed no obvious banding of autofluorescent dots between divided nuclei of asparagus meiocytes, as one would expect in Arabidopsis. This description of wild-type asparagus meiosis will serve as a reference for the analyses of meiotic mutants, as well as for comparative studies among difference species. Abbreviations: DAPI: 4',6-diamidino-2-phenylindole; FISH: fluorescence in situ hybridization; PBS: phosphate-buffered saline; PMC: pollen mother cell; SEM: Scanning Electron Microscope.


Assuntos
Asparagus/ultraestrutura , Cromossomos de Plantas/ultraestrutura , Meiose , Células Vegetais/ultraestrutura , Pólen/ultraestrutura , Arabidopsis/genética , Arabidopsis/crescimento & desenvolvimento , Arabidopsis/ultraestrutura , Asparagus/genética , Asparagus/crescimento & desenvolvimento , Núcleo Celular/metabolismo , Núcleo Celular/ultraestrutura , Cromossomos de Plantas/química , Flores/genética , Flores/crescimento & desenvolvimento , Flores/ultraestrutura , Hibridização in Situ Fluorescente , Microscopia Eletrônica de Varredura , Células Vegetais/metabolismo , Pólen/genética , Pólen/crescimento & desenvolvimento
7.
Analyst ; 143(24): 5926-5934, 2018 Dec 03.
Artigo em Inglês | MEDLINE | ID: mdl-30327804

RESUMO

Recent super-resolution fluorescence microscopy (3D-Structured Illumination Microscopy, 3D-SIM) studies have revealed significantly altered nuclear organization between normal lymphocyte nuclei and those of classical Hodgkin's Lymphoma. Similar changes have been found in Multiple Myeloma (MM) nuclei, as well as in a premalignant condition, Monoclonal Gammopathy of Unknown Significance (MGUS). Using 3D-SIM, an increase in DNA-poor and DNA-free voids was evident in reconstructed 3D-SIM images of diseased nuclei at 40 nm pixel resolution (x,y: 40 nm, z: 80 nm). At best, far-field FTIR imaging yields spatially resolved images at ∼500 nm spatial resolution; however, near-field infrared imaging breaks the diffraction limit at a scale comparable to that of 3D-SIM, providing details on the order of 30 nm spatial resolution. We report here the first near-field IR imaging of lymphocyte nuclei, and far-field IR imaging results of whole lymphocytes and nuclei from normal human blood. Cells and nuclei were mounted on infrared-compatible substrates, including CaF2, undoped silicon wafers, and gold-coated silicon wafers. Thermal source far-field FTIR images were obtained with an Agilent-Cary 620 microscope, 15× objective, 0.62 NA and 64 × 64 array Focal Plane Array detector (University of Manitoba), or with a similar microscope equipped with both 15× and 25× (0.81 NA) objectives, 128 × 128 FPA and either thermal source or synchrotron source (single beam) infrared light at the Advanced Light Source (ALS), LBNL, Berkeley CA. Near-field IR spectra were acquired at the ALS, on the in-house SINS equipment, as well as with a Neaspec system, both illuminated with synchrotron light. Finally, some near-field IR spectra and images were acquired at Neaspec GmbH, Germany. Far-field IR spectra of normal cells and nuclei showed the characteristic bands of DNA and proteins. Near-field IR spectra of nuclei showed variations in bands assigned to protein and nucleic acids including single and double-stranded DNA. Near-field IR images of nuclei enabled visualization of protein and DNA distribution in spatially-resolved chromosome territories and nuclear pores.


Assuntos
Núcleo Celular/ultraestrutura , Linfócitos/citologia , Linhagem Celular Tumoral , Núcleo Celular/química , Doença de Hodgkin/patologia , Humanos , Imageamento Tridimensional/métodos , Linfócitos/química , Microscopia de Fluorescência/métodos , Espectrofotometria Infravermelho/métodos
8.
Tsitol Genet ; 50(5): 3-16, 2016.
Artigo em Inglês, Russo | MEDLINE | ID: mdl-30480911

RESUMO

A comparative cytological analysis of intra- and intertissular cytomictic interactions in early micro-sporogenesis of mono- and dicotyledonous plants was performed by the example of the two cellular systems - microsporocytes and tapetum. It is found that cytomixis is the component of intratissular interactions mainly. In the tapetum cells cytomixis is notable for structural and temporary taxon specific features. The nuclear migration in microsporocytes is confined mainly to zygotene-pachytene meiotic stages and characterized by a certain synchronism with cytomixis at the tapetum. Intertissular cytomictic interactions (tapetum - microsporocytes) were found in the monocot anthers only. Intertissular interactions are likely to reflect the intensification of competitive relations between the tapetum and microsporocytes for area in the process of anther tissue differentiation. Polyploid tapetum nucleus and syncytia being powerful acceptors are able to compete with microsporocytes and direct the chromatin translocation to their favor. The absence of intertissular interactions in dicots probably reflects a better balance between the processes of differentiation at somatic and generative tissues into microsporangium compared to monocots.


Assuntos
Allium/metabolismo , Gametogênese Vegetal/genética , Lilium/metabolismo , Nicotiana/metabolismo , Allium/citologia , Comunicação Celular , Núcleo Celular/metabolismo , Núcleo Celular/ultraestrutura , Cromatina/química , Flores/citologia , Flores/metabolismo , Lilium/citologia , Meiose , Pólen/metabolismo , Pólen/ultraestrutura , Nicotiana/citologia
9.
Food Chem Toxicol ; 83: 183-92, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26116884

RESUMO

In this study, we examined the mechanism underlying the effect of Saururus chinensis Baill (saururaceae) on hepatocellular carcinoma HepG2 cells. HepG2 cells and Chang cells were exposed to various concentrations of S. chinensis Baill extract (SC-E) for 24 h. SC-E affected more significantly HepG2 cells than Chang cells in terms of cell viability and ATP production. Therefore, current study examined detailed mechanism how SC-E affected HepG2 cell survival. We found that SC-E (75 and 150 µg/ml) induced apoptosis via oxidative stress. SC-E also caused CCAAT-enhancer-binding protein homologous protein (CHOP) activation by dissociating the binding immunoglobulin protein (BiP) from inositol-requiring 1α (IRE1α) in the endoplasmic reticulum (ER) and induced Bax, cytochrome c release to cytosol, caspase-3 activation, and poly ADP ribose polymerase (PARP) cleavage, resulting in HepG2 cell apoptosis. Furthermore, SC-E caused ER Ca(2+) leakage into the cytosol; ER dilation and mitochondrial membrane damage were observed in transmission electron microscopy (TEM). Taken together, our results demonstrated that SC-E induced cancer cell apoptosis specifically through ER stress.


Assuntos
Antineoplásicos Fitogênicos/farmacologia , Apoptose/efeitos dos fármacos , Carcinoma Hepatocelular/tratamento farmacológico , Estresse do Retículo Endoplasmático/efeitos dos fármacos , Neoplasias Hepáticas/tratamento farmacológico , Extratos Vegetais/farmacologia , Saururaceae/química , Antineoplásicos Fitogênicos/efeitos adversos , Sinalização do Cálcio/efeitos dos fármacos , Carcinoma Hepatocelular/metabolismo , Carcinoma Hepatocelular/ultraestrutura , Núcleo Celular/efeitos dos fármacos , Núcleo Celular/metabolismo , Núcleo Celular/ultraestrutura , Sobrevivência Celular/efeitos dos fármacos , Retículo Endoplasmático/efeitos dos fármacos , Retículo Endoplasmático/metabolismo , Retículo Endoplasmático/ultraestrutura , Metabolismo Energético/efeitos dos fármacos , Células Hep G2 , Hepatócitos/efeitos dos fármacos , Humanos , Neoplasias Hepáticas/metabolismo , Neoplasias Hepáticas/ultraestrutura , Medicina Tradicional do Leste Asiático , Microscopia Eletrônica de Transmissão , Membranas Mitocondriais/efeitos dos fármacos , Membranas Mitocondriais/metabolismo , Membranas Mitocondriais/ultraestrutura , Estresse Oxidativo/efeitos dos fármacos , Extratos Vegetais/efeitos adversos , República da Coreia
10.
Micron ; 74: 1-7, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-25910428

RESUMO

The mature massula of H. arinaria was examined by means of transmission electron microscopy, with the aim to understand the nature of cohesion between grains, the accumulation of pollen storage reserves, and the behavior of the nucleus of the vegetative cell in this composite type of pollen. The massula was a union of a large number of polygonal pollen grains that were tightly linked together. The exine within the massula were highly simplified, consisting of a single layer of nexine-2, lacking tectum, bacula, and nexine-1, while all the four layers comprised the exine on the massula surface. The two layers of nexine-2 of adjacent grains fused into a seamless whole. Undoubtedly the fusion of the nexine-2 was the mechanism by which the grains of the massula were linked together. No starch grains, lipid bodies, or storage proteins were present in the mature massula, and so the composite pollen of this species belonged to a novel type with regard to storage reserves. The vegetative nucleus was not lobed and revealed a huge amount of highly condensed chromatin, indicating a quiescent status. The condensed status of the vegetative nuclei in this composite type of pollen system is in striking contrast to the highly decondensed status reported in the free type of pollen grains.


Assuntos
Orchidaceae/ultraestrutura , Pólen/ultraestrutura , Núcleo Celular/ultraestrutura , Microscopia Eletrônica de Transmissão , Pólen/citologia
11.
Phytomedicine ; 22(2): 238-44, 2015 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-25765828

RESUMO

A 8.7 kDa lectin with high agglutin activity was isolated by affinity chromatography and cloned from Allium chinense in this study. For the MTT assay, approximately 60 µg/ml A. chinense lectin (ACL) inhibited 50% of the human hepatoma Hep-3B cells grown after 48 h. In addition, no antiproliferative effect was observed on normal human umbilical vein endothelial cells (HUVEC) even at 100 µg/ml concentration. After treatments with ACL on Hep-3B cells, morphologic changes in the nucleus and cytoskeleton were observed under laser scanning confocal microscopy with 4',6-diamidino-2-phenylindole and tubulin Alexa Fluor 488 staining; whereas, the mitochondrial membrane potential was observed through Mito Tracker Red CMXRos staining. The results showed that ACL led to cell morphology and structure change (e.g., round cell shrinkage). Moreover, ACL resulted in significant change in the shape of the nucleus, damaged the cytoskeleton when tubulin was degraded, and reduced the mitochondrial transmembrane potential. By contrast, no changes were observed on HUVEC cells under the same treatment conditions. DNA fragmentation analysis was used to detect DNA damage. Western blot showed that ACL upregulated caspase-3 and Bax expression during apoptosis and cloned the structural gene of ACL with an open reading frame of 456 bp encoding 151 amino acid residues. The results showed that ACL is a potential anticancer drug.


Assuntos
Allium/química , Apoptose/efeitos dos fármacos , Lectinas/farmacologia , Sequência de Aminoácidos , Antineoplásicos Fitogênicos/farmacologia , Sequência de Bases , Caspase 3/metabolismo , Linhagem Celular Tumoral , Núcleo Celular/ultraestrutura , Clonagem Molecular , Citoesqueleto/ultraestrutura , Células Endoteliais da Veia Umbilical Humana/efeitos dos fármacos , Células Endoteliais da Veia Umbilical Humana/ultraestrutura , Humanos , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Dados de Sequência Molecular , Proteínas Recombinantes/farmacologia , Proteína X Associada a bcl-2/metabolismo
12.
Plant Cell Rep ; 34(5): 853-60, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25627254

RESUMO

KEY MESSAGE: We describe two types of plastid outgrowths visualised in potato tubers after carboxyfluorescein diacetate staining. Probable esterase activity of the outgrowths has been demonstrated for the first time ever. Plastid outgrowths were observed in the phelloderm and storage parenchyma cells of red potato (S. tuberosum L. cv. Rosalinde) tubers after administration of carboxyfluorescein diacetate stain. Endogenous esterases cleaved off acetic groups to release membrane-unpermeable green fluorescing carboxyfluorescein which accumulated differentially in particular cell compartments. The intensive green fluorescence of carboxyfluorescein exhibited highly branched stromules (stroma-filled plastid tubular projections of the plastid envelope) and allowed distinguishing them within cytoplasmic strands of the phelloderm cells. Stromules (1) were directed towards the nucleus or (2) penetrated the whole cells through the cytoplasmic bands of highly vacuolated phelloderm cells. Those directed towards the nucleus were flattened and adhered to the nuclear envelope. Stromule-like interconnections between two parts of the same plastids (isthmuses) were also observed. We also documented the formation of another type of the stroma-filled plastid outgrowths, referred to here as protrusions, which differed from previously defined stromules in both morphology and esterase activity. Unlike stromules, the protrusions were found to be associated with developmental processes leading to starch accumulation in the storage parenchyma cells. These results strongly suggest that stromules and protrusions exhibit esterase activity. This has been demonstrated for the first time. Morphological and biochemical features as well as possible functions of stromules and protrusions are discussed below.


Assuntos
Fluoresceínas , Corantes Fluorescentes , Tubérculos/ultraestrutura , Plastídeos/ultraestrutura , Solanum tuberosum/ultraestrutura , Núcleo Celular/metabolismo , Núcleo Celular/ultraestrutura , Citoplasma/metabolismo , Citoplasma/ultraestrutura , Tubérculos/metabolismo , Plastídeos/metabolismo , Solanum tuberosum/crescimento & desenvolvimento , Coloração e Rotulagem
13.
Micron ; 70: 7-20, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25541480

RESUMO

Tobraviruses, like other (+) stranded RNA viruses of plants, replicate their genome in cytoplasm and use such usual membranous structures like endoplasmic reticulum. Based on the ultrastructural examination of Tobacco rattle virus (TRV)-infected potato and tobacco leaf tissues, in this work we provide evidence of the participation of not only the membranous and vesicular ER structures but also other cell organelles during the viral infection cycle. Non-capsidated TRV PSG particles (potato isolate from the Netherlands) (long and short forms) were observed inside the nucleus while the presence of TRV capsid protein (CP) was detected in the nucleus caryolymph and within the nucleolus area. Both capsidated and non-capsidated viral particles were localized inside the strongly disorganized chloroplasts and mitochondria. The electron-dense TRV particles were connected with vesicular structures of mitochondria as well as with chloroplasts in both potato and tobacco tissues. At 15-30 days after infection, vesicles filled with TRV short particles were visible in mitochondria revealing the expanded cristae structures. Immunodetection analysis revealed the TRV PSG CP epitope inside chloroplast with disorganized thylakoids structure as well as in mitochondria of different tobacco and potato tissues. The ultrastructural analysis demonstrated high dynamics of the main cell organelles during the TRV PSG-Solanaceous plants interactions. Moreover, our results suggest a relationship between organelle changes and different stages of virus infection cycle and/or particle formation.


Assuntos
Retículo Endoplasmático/ultraestrutura , Organelas/ultraestrutura , Organelas/virologia , Doenças das Plantas/virologia , Vírus de Plantas/fisiologia , Vírus de RNA/fisiologia , Proteínas do Capsídeo/isolamento & purificação , Núcleo Celular/ultraestrutura , Núcleo Celular/virologia , Cloroplastos/ultraestrutura , Cloroplastos/virologia , Retículo Endoplasmático/virologia , Células do Mesofilo/ultraestrutura , Células do Mesofilo/virologia , Microscopia Eletrônica de Transmissão , Mitocôndrias/ultraestrutura , Mitocôndrias/virologia , Floema/ultraestrutura , Floema/virologia , Folhas de Planta/virologia , Vírus de Plantas/ultraestrutura , Vírus de RNA/ultraestrutura , Solanum tuberosum/virologia , Nicotiana/virologia
14.
Sci Rep ; 4: 4416, 2014 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-24646833

RESUMO

To study the mechanism of tea polyphenols (TP)-induced apoptosis of breast cancer cells. Proliferation of MCF-7 and SK-BR-3 cells was evaluated by MTT assays. Cellular ultrastructure was examined by electron microscopy. Apoptosis was detected by TUNEL. PCNA、 Cyclin D1、 Cyclin E and Survivin expression was measured by Western blot. Cell proliferation was significantly inhibited by TP. Spindle and round cells were loosely distributed with increased particles after TP treatment. Increased cell size, frequent nuclear atypia and a collapse of apoptosis were observed. The nucleus was pushed towards one side, while the cytoplasm was rich in free ribosome. The membrane of mitochondria was thickening, and the cell apoptotic body was observed. TP treated cells experienced significantly enhanced apoptosis compared with 5-Fu treated or control groups. The expression of survivin was downregulated by TP. To conclude, TP can inhibit cell growth and induce apoptosis through downregulating the expression of survivin in breast cancer.


Assuntos
Antineoplásicos Fitogênicos/farmacologia , Apoptose/efeitos dos fármacos , Regulação Neoplásica da Expressão Gênica , Proteínas Inibidoras de Apoptose/antagonistas & inibidores , Polifenóis/farmacologia , Chá/química , Animais , Antineoplásicos Fitogênicos/isolamento & purificação , Neoplasias da Mama , Linhagem Celular Tumoral , Núcleo Celular/efeitos dos fármacos , Núcleo Celular/ultraestrutura , Proliferação de Células/efeitos dos fármacos , Ciclina D1/genética , Ciclina D1/metabolismo , Ciclina E/genética , Ciclina E/metabolismo , Relação Dose-Resposta a Droga , Feminino , Humanos , Proteínas Inibidoras de Apoptose/genética , Proteínas Inibidoras de Apoptose/metabolismo , Células MCF-7 , Camundongos , Camundongos Nus , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/ultraestrutura , Polifenóis/isolamento & purificação , Antígeno Nuclear de Célula em Proliferação/genética , Antígeno Nuclear de Célula em Proliferação/metabolismo , Transdução de Sinais , Survivina , Carga Tumoral/efeitos dos fármacos , Ensaios Antitumorais Modelo de Xenoenxerto
15.
Cell Biol Int ; 38(4): 472-9, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24390765

RESUMO

The bipolar spindle is a major cytoskeletal structure, which ensures an equal chromosome distribution between the daughter nuclei. The spindle formation in animal cells depends on centrosomes activity. In flowering plant cells the centrosomes have not been identified as definite structures. The absence of these structures suggests that plants assemble their spindle via novel mechanisms. Nonetheless, the cellular and molecular mechanisms controlling the cytoskeleton remodeling during the spindle development in plants are still insufficiently clear. This article describes the results of a comparative analysis of the microtubular cytoskeleton dynamics during assembly of the second division spindle in tobacco microsporocytes with the normal and deformed nuclei. According to our observations, the bipolar spindle fibres are formed from short arrays of the disintegrated perinuclear cytoskeleton system, the perinuclear microtubular band. The microsporocytes of polyploid tobacco plants with deformed nuclei entirely lack this cytoskeleton structure. In such type of cells the overall prometaphase events are blocked, and the assembly of second division spindles is completely arrested.


Assuntos
Núcleo Celular/metabolismo , Meiose , Nicotiana/citologia , Nicotiana/metabolismo , Fuso Acromático/metabolismo , Núcleo Celular/ultraestrutura , Citoesqueleto/química , Citoesqueleto/metabolismo , Células Vegetais/química , Células Vegetais/metabolismo , Pólen/química , Pólen/metabolismo , Poliploidia , Fuso Acromático/química
16.
Morfologiia ; 146(5): 19-23, 2014.
Artigo em Russo | MEDLINE | ID: mdl-25823284

RESUMO

The aim of the present study was to investigate the ultrastructural changes developing in histaminergic neurons of the brain of 24 outbred albino male rats-after administration of ethanol in the acute experiment (single intraperitoneal dose of 1 and 4 g/kg), subacute exposure (as the sole source of drinking at a dose of 4 g/kg for 7 days), or chronic administration (at a dose of 2-3 g/kg/day for 6 months). After alcohol administration histaminergic neurons were found to develop various ultrastructural changes of their nucleus and organelles. They reflect the processes of neuron destruction, as well as adaptive changes aimed at restoring and maintaining their functions. These changes were nonspecific and -depended on the dose, time after injection and duration of alcohol administration. In general they corresponded to the structural and histochemical changes observed at light-microscopic level.


Assuntos
Alcoolismo/patologia , Etanol/toxicidade , Histamina/metabolismo , Hipotálamo/efeitos dos fármacos , Neurônios/ultraestrutura , Animais , Núcleo Celular/ultraestrutura , Etanol/administração & dosagem , Hipotálamo/patologia , Masculino , Neurônios/efeitos dos fármacos , Neurônios/metabolismo , Ratos
17.
Annu Rev Genet ; 47: 167-86, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24016193

RESUMO

Reversible modification of proteins by SUMO (small ubiquitin-like modifier) affects a large number of cellular processes. In striking contrast to the related ubiquitin pathway, only a few enzymes participate in the SUMO system, although this pathway has numerous substrates as well. Emerging evidence suggests that SUMOylation frequently targets entire groups of physically interacting proteins rather than individual proteins. Protein-group SUMOylation appears to be triggered by recruitment of SUMO ligases to preassembled protein complexes. Because SUMOylation typically affects groups of proteins that bear SUMO-interaction motifs (SIMs), protein-group SUMOylation may foster physical interactions between proteins through multiple SUMO-SIM interactions. Individual SUMO modifications may act redundantly or additively, yet they may mediate dedicated functions as well. In this review, we focus on the unorthodox principles of this pathway and give examples for SUMO-controlled nuclear activities. We propose that collective SUMOylation is typical for nuclear assemblies and argue that SUMO serves as a distinguishing mark for functionally engaged protein fractions.


Assuntos
Núcleo Celular/metabolismo , Proteínas/metabolismo , Sumoilação/fisiologia , Adenosina Trifosfatases/metabolismo , Motivos de Aminoácidos , Animais , Proteínas de Ciclo Celular/metabolismo , Núcleo Celular/ultraestrutura , Reparo do DNA/fisiologia , Enzimas/metabolismo , Humanos , Lisina/metabolismo , Modelos Biológicos , Complexos Multiproteicos , Proteínas Nucleares/metabolismo , Antígeno Nuclear de Célula em Proliferação/metabolismo , Mapeamento de Interação de Proteínas , Proteômica , Ribossomos/metabolismo , Especificidade por Substrato , Sumoilação/genética , Telômero/metabolismo , Homeostase do Telômero/fisiologia , Enzimas de Conjugação de Ubiquitina/metabolismo , Ubiquitina-Proteína Ligases/metabolismo , Ubiquitinação , Proteína com Valosina
18.
Biophys J ; 105(2): 310-9, 2013 Jul 16.
Artigo em Inglês | MEDLINE | ID: mdl-23870252

RESUMO

It is a challenging task to characterize the biodistribution of nanoparticles in cells and tissue on a subcellular level. Conventional methods to study the interaction of nanoparticles with living cells rely on labeling techniques that either selectively stain the particles or selectively tag them with tracer molecules. In this work, Raman imaging, a label-free technique that requires no extensive sample preparation, was combined with multivariate classification to quantify the spatial distribution of oxide nanoparticles inside living lung epithelial cells (A549). Cells were exposed to TiO2 (titania) and/or α-FeO(OH) (goethite) nanoparticles at various incubation times (4 or 48 h). Using multivariate classification of hyperspectral Raman data with partial least-squares discriminant analysis, we show that a surprisingly large fraction of spectra, classified as belonging to the cell nucleus, show Raman bands associated with nanoparticles. Up to 40% of spectra from the cell nucleus show Raman bands associated with nanoparticles. Complementary transmission electron microscopy data for thin cell sections qualitatively support the conclusions.


Assuntos
Núcleo Celular/metabolismo , Células Epiteliais/metabolismo , Compostos Férricos/metabolismo , Nanopartículas Metálicas , Titânio/metabolismo , Transporte Biológico , Linhagem Celular Tumoral , Núcleo Celular/ultraestrutura , Células Epiteliais/ultraestrutura , Humanos , Pulmão/citologia , Análise Multivariada , Análise Espectral Raman
19.
Cell Biol Int ; 37(3): 203-12, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23348893

RESUMO

The late stages of microsporogenesis in the family Cyperaceae are marked by the formation of an asymmetrical tetrad, degeneration of three of the four nuclei resulting from meiosis and the formation of pseudomonads. In order to understand the cytological changes involved in the development of pseudomonads, a combination of 11 different techniques (conventional staining, cytochemistry procedures, immunofluorescence, FISH and transmission electron microscopy: TEM) were used to study the later stages of microsporogenesis in Rhynchospora pubera. The results demonstrated the occurrence of two cytoplasmic domains in the pseudomonads, one functional and the other degenerative, which are physically and asymmetrically separated by cell plate with an endomembrane system rich in polysaccharides. Other changes associated with endomembrane behaviour were observed, such as a large number of lipid droplets, vacuoles containing electron-dense material and concentric layers of endoplasmic reticulum. Concomitant with the isolation of degenerative nuclei, the tapetal cells also showed evidence of degeneration, indicating that both tissues under programmed cell death (PCD), as indicated by immunofluorescence and TEM procedures. The results are significant because they associate cellular polarisation and asymmetry with different cytoplasmic domains, and hence open new possibilities for studying cellular compartmentalisation and PCD.


Assuntos
Cyperaceae/ultraestrutura , Citocinese , Pólen/ultraestrutura , Apoptose , Sequência de Bases , Núcleo Celular/metabolismo , Núcleo Celular/ultraestrutura , Parede Celular/metabolismo , Parede Celular/ultraestrutura , Cyperaceae/crescimento & desenvolvimento , Cyperaceae/metabolismo , Galactanos/metabolismo , Pectinas/metabolismo , Pólen/crescimento & desenvolvimento , Pólen/metabolismo
20.
Genetika ; 49(8): 909-20, 2013 Aug.
Artigo em Russo | MEDLINE | ID: mdl-25474878

RESUMO

Existing data in the literature on polyteny in plants and in eukaryotes in general, data on the structure of interphase chromosomes and their association with the nuclear membrane are analyzed in the paper. In light of these data, the results of our studies on the ratios of phenotypic classes of marker enzymes in agamospermy (apomictic) progeny of sugar beet are considered. The given data allow to state that chromosome polyteny and their association with nuclear membrane provide not only hereditary information, but also determine the ratio of genotypes and phenotypes in progeny.


Assuntos
Cromossomos de Plantas , Plantas/genética , Cromossomos Politênicos , Animais , Beta vulgaris/genética , Núcleo Celular/ultraestrutura , Cromossomos de Insetos
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