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Search Results: 1 - 10 of 18309 matches for " programmed cell death "
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MicroRNA-21, 204 and 125b Play Potential Roles in Tumorigenesis of Melanoma  [PDF]
Chengtan Li, Xiayu Wang, Ya’ni Chen, Xiaohua Tan, Wen Li, Sheng Yan, Weibin Cai, Xianrong Xu, Liangwen Xu, Lei Yang, Yutao Yan
Advances in Bioscience and Biotechnology (ABB) , 2015, DOI: 10.4236/abb.2015.612071
Abstract: Aim: The high mortality rate of melanoma is due to partially the lack of good diagnostic markers and treatment strategies. Over the past several years, several microRNA (miRNA) profiling studies have been performed on melanoma tissues, but with extremely inconsistency, the diagnostic value of miRNA candidates in melanoma remains under debate. Thus, this study aims to systematically evaluate the consistency of miRNAs tissue in multiple independent studies in melanoma. Method: Eligible studies were screened and selected from the PubMed, EMBASE, and Web of Science. A systematic analysis of published miRNA expression studies that compared the miRNA expression profiles between melanoma tissues and normal skin tissue was conducted. A vote-counting strategy was followed with the collection of information. Real time PCRs were employed to validate miRNA candidates with high consistency. Targets of consistent miRNAs were predicted by online programs (like miRTarBase, microRNA.org and TargetScanHuman 6.2). Enrichment analyses for gene ontology (GO) terms and Kyoto encyclopedia of genes and genomes (KEGG) pathways were carried out with Database for Annotation, Visualization, and Integrated Discovery (DAVID). Results: A total of 303 differentially expressed miRNAs were reported in the 10 miRNA-profiling studies during comparison of melanoma tissues with normal tissues; 132 were up-regulated in melanoma, and 171 were down-regulated. However, in the group of consistently reported miRNAs (cutoff > 3 times), only moderate numbers of consistent and differentially expressed miRNAs were selected. miRNA-21 was found increased in 5 different studies, miRNA-146b, miRNA-17 and miRNA-18a were reported up-regulated in 4 profiling studies. Meanwhile, miRNA-204 and miRNA-125b were found down-regulated in 5 studies, miRNA-141, miRNA-149, miRNA-224, miRNA-200b, miRNA-200c were consistently decreased in just 4 out of 10 profiling studies in total. The directions of differential expression of these miRNA candidates were confirmed by real time PCRs. Enrichment analyses demonstrated that programmed cell death and transcription regulation played very important roles in the involvement of miRNAs in tumorigenesis of melanoma. Conclusion: This systematic study of melanoma miRNA profiling studies would provide rich information on miRNAs with potential role as the biomarkers and therapeutic agents with high consistency in melanoma.
PAR-1 activation by SFLLRNP decreases myelin deposition on lumbar motor neuron axons as assessed with cupric silver staining
Candice Meuleners,Victoria Turgeon
Impulse : an Undergraduate Journal for Neuroscience , 2010,
Abstract: Working through protease-activated receptors (PARs), serine proteases have been shown to play important roles in neuronal and glial cell survival during development and in neurodegeneration. Past studies in chick embryos have shown that PAR-1 activation during the period of lumbar motor neuron programmed cell death (PCD) leads to a decreased number of surviving motor neurons by embryonic day 10 (E10). Retrospective analysis of these tissues revealed increased thionin staining in the white matter of these spinal cords, interesting because thionin does not normally stain myelinated areas. We hypothesized that PAR-1 activation decreases myelin deposition in developing spinal cords. To activate PAR-1, embryos were treated with the amino acid sequence SFLLRNP for five consecutive days beginning on E5. Embryos were sacrificed on E10, prepared for histology, and stained with cupric silver. The ventral hemispheres of lumbar sections were examined for the degree of demyelination as characterized by punctate or linear silver markings in the white matter. Experimental embryos were found to exhibit statistically more punctate markings and linear markings. This study shows that in addition to decreasing motor neuron survival, PAR-1 activation potentially decreases the conducting ability and viability of the surviving motor neurons.
Effects of three controlled mechanical ventilation modes on rat lung hydrogen peroxide and apoptosis during hemorrhagic shock  [PDF]
Amanda R. Thimmesch, Qiuhua Shen, Richard L. Clancy, Janet D. Pierce
Open Journal of Molecular and Integrative Physiology (OJMIP) , 2013, DOI: 10.4236/ojmip.2013.31005
Abstract: Hemorrhagic shock causes a reduction in oxygen supply to tissues leading to increased reactive oxygen species resulting in lung injury. Often mechanical ventilation is required as supportive treatment; however, ventilation can also induce lung injury and apoptosis. The purpose of this study was to examine the effects of three modes of controlled mechanical ventilation: volume control, pressure control, and pressure regulated volume control on lung injury as measured by hydrogen peroxide and apoptosis during hemorrhagic shock. Male Sprague-Dawley rats were randomized to the three controlled mechanical ventilation groups. Hemorrhagic shock was elicited by removing approximately 40% of the blood volume over 30 minutes. The rats were treated with one of three modes of mechanical ventilation with 40% oxygen for 60 minutes. The lungs were removed and measured for hydrogen peroxide and apoptosis based on nuclear differential dye uptake. There were no significant differences in hemodynamics, arterial blood values, peak inspiratory pressures, tidal volume, respiratory rates, and intrathoracic pressures across three groups. However, lung hydrogen peroxide production and apoptosis were significantly increased in volume control and pressure control, compared to pressure-regulated volume control. In this study, early signs of ventilator induced lung injury were not detected using commonly employed clinical measurements. However, when examining lung cellular injury (hydrogen peroxide and apoptosis), we were able to measure significant lung damage in volume control and pressure control, but not pressure-regulated volume control. Thus, our results suggest that pressure-regulated volume control is the preferable mode of mechanical ventilation during hemorrhagic shock.
Stress responses of tomato protoplasts to copper and paraquat
Rueda, Antoni;Rojas, Mauricio;Lobo, Mario;Urrea, Aura;Restrepo, Catalina;Botero, Catalina;Pelaez, Carlos;
Tropical Plant Pathology , 2011, DOI: 10.1590/S1982-56762011000200003
Abstract: plants are often exposed to external biotic or abiotic agents that can damage cells. biotic agents include molecules produced by pathogens, and abiotic agents include ultraviolet radiation, heavy metals and xenobiotic agents such as herbicides. because of the importance of abiotic stresses and the limited knowledge of the defense responses of plants to stresses, a study was conducted using flow cytometry to evaluate endocellular events in protoplasts of two tomato species, lycopersicon hirsutum and lycopersicon esculentum, following exposure to 10 mm cucl2 and 1% paraquat. during the first 30 min of exposure to 10 mm cucl2, mean fluorescence intensity values in both species decreased by more than 50% compared to the untreated control. during the first 30 min of paraquat treatment, the production of reactive oxygen species, evaluated as the incidence of protoplasts in which the superoxide anion was present, was 32.9 % and 25.4%, respectively, for l. hirsutum and l. esculentum. hyperpolarization of the mitochondria for both tomatoes species was observed during the first 2 h. the absence of early membrane damage and the markedly detrimental effects of the treatments on the mitochondria suggest that additional mechanisms which lead to cell death may be involved in these processes, and that these mechanisms may be associated with apoptosis.
Cloning and characterization of a gene encoding cysteine proteases from senescent leaves of Gossypium hirsutum
Fafu Shen,Shuxun Yu,Xiulan Han,Shuli Fan
Chinese Science Bulletin , 2004, DOI: 10.1360/982004-401
Abstract: A gene encoding a cysteine proteinase was isolated from senescent leave of cotton (Gossypium hirsutum) cv liaomian No. 9 by utilizing rapid amplification of cDNA ends polymerase chain reaction (RACE-PCR), and a set of consensus oligonucleotide primers was designed to anneal the conserved sequences of plant cysteine protease genes. The cDNA, which designated Ghcysp gene, contained 1368 bp terminating in a poly(A)+ trail, and included a putative 5′(98 bp) and a 3′(235 bp) non-coding region. The opening reading frame (ORF) encodes polypeptide 344 amino acids with the predicted molecular mass of 37.88 kD and theoretical pI of 4.80. A comparison of the deduced amino acid sequence with the sequence in the GenBank database has shown considerable sequence similarity to a novel family of plant cysteine proteases. This putative cotton Ghcysp protein shows from 67% to 82% identity to the other plants. All of them share catalytic triad of residues, which are highly conserved in three regions. Hydropaths analysis of the amino acid sequence shows that the Ghcysp is a potential membrane protein and localizes to the vacuole, which has a transmembrane helix between resides 7–25. A characteristic feature of Ghcysp is the presence of a putative vacuole-targeting signal peptide of 19-amino acid residues at the N-terminal region. The expression of Ghcysp gene was determined using northern blot analysis. The Ghcysp mRNA levels are high in development senescent leaf but below the limit of detection in senescent root, hypocotyl, faded flower, 6 d post anthesis ovule, and young leaf.
Temporal and spatial changes in Ca2+ distribution during the programmed cell death of tracheary elements
Zongshen Zhang,Rongqian Li,Jianbo Wang
Chinese Science Bulletin , 2001, DOI: 10.1007/BF02901166
Abstract: The changes in Ca2+ distribution in the tracheary elements (TEs) of the pepper leaves were studied using the cytochemical method of potassium antimonate. At the early stage of TEs formation, the vacuole and the nucleus held large volume, and antimonate Ca2+ deposits were observed mainly in the intercellular space and the cell wall. As the thickening of secondary wall occurred, the vacuole, nucleus and other organelles began to rupture, concomitant with the increase of calcium deposits in the cytosol, showing the influx of Ca2+ into the cell. With the further rupture of cytoplasm and other organelles, the number of calcium deposits at the non-thickening cell wall increased, but declined at the thickening bands of the secondary wall. When the cytoplasmic contents disappeared completely, the level of Ca2+ decreased at the non-thickening wall, but by contrast, increased at the thickening bands of the secondary wall. These observations indicated that the dynamic changes in Ca2+ distribution spatially and temporarily might have a close correlation with its distinct roles played during the formation of the secondary walls.
Utility of Computational Methods to Identify the Apoptosis Machinery in Unicellular Eukaryotes
Pierre Marcel Durand,Theresa Louise Coetzer
Bioinformatics and Biology Insights , 2008,
Abstract: Apoptosis is the phenotypic result of an active, regulated process of self-destruction. Following various cellular insults, apoptosis has been demonstrated in numerous unicellular eukaryotes, but very little is known about the genes and proteins that initiate and execute this process in this group of organisms. A bioinformatic approach presents an array of powerful methods to direct investigators in the identification of the apoptosis machinery in protozoans. In this review, we discuss some of the available computational methods and illustrate how they may be applied using the identification of a Plasmodium falciparum metacaspase gene as an example.
Ultrabithorax confers spatial identity in a context-specific manner in the Drosophila postembryonic ventral nervous system
Marin Elizabeth C,Dry Katie E,Alaimo Danielle R,Rudd Kirstin T
Neural Development , 2012, DOI: 10.1186/1749-8104-7-31
Abstract: Background In holometabolous insects such as Drosophila melanogaster, neuroblasts produce an initial population of diverse neurons during embryogenesis and a much larger set of adult-specific neurons during larval life. In the ventral CNS, many of these secondary neuronal lineages differ significantly from one body segment to another, suggesting a role for anteroposterior patterning genes. Results Here we systematically characterize the expression pattern and function of the Hox gene Ultrabithorax (Ubx) in all 25 postembryonic lineages. We find that Ubx is expressed in a segment-, lineage-, and hemilineage-specific manner in the thoracic and anterior abdominal segments. When Ubx is removed from neuroblasts via mitotic recombination, neurons in these segments exhibit the morphologies and survival patterns of their anterior thoracic counterparts. Conversely, when Ubx is ectopically expressed in anterior thoracic segments, neurons exhibit complementary posterior transformation phenotypes. Conclusion Our findings demonstrate that Ubx plays a critical role in conferring segment-appropriate morphology and survival on individual neurons in the adult-specific ventral CNS. Moreover, while always conferring spatial identity in some sense, Ubx has been co-opted during evolution for distinct and even opposite functions in different neuronal hemilineages.
Tomato Plants Overexpressing a Celery Mannitol Dehydrogenase (MTD) Have Decreased Susceptibility to Botrytis cinerea  [PDF]
Takshay K. Patel, Sergei F. Krasnyanski, George C. Allen, Frank J. Louws, Dilip R. Panthee, John D. Williamson
American Journal of Plant Sciences (AJPS) , 2015, DOI: 10.4236/ajps.2015.68116
Abstract: The oxidative burst is a critical early event in plant-pathogen interactions that leads to a localized, programmed cell death (PCD) called the hypersensitive response (HR). The HR and associated PCD retard infection by biotrophic pathogens, but can, in fact, enhance infection by necrotrophic pathogens like Botrytis cinerea. In addition to signaling the induction of the HR, reactive oxygen species (ROS) produced during the oxidative burst are?antimicrobial. We hypothesize that pathogens such as B. cinerea survive the antimicrobial effects of ROS, at least partially by secreting the antioxidant mannitol during infection. This is supported by the previous observation that overexpression of the catabolic enzyme mannitol dehydrogenase (MTD) can decrease a plants susceptibility to mannitol-secreting pathogens like B. cinerea. To extend the above hypothesis, and test the general utility of this approach in an important horticultural crop, we overexpressed celery MTD in tomato (Solanum lycopersicum cv. “Moneymaker”). In these studies, we observed a significant increase (up to 90%) in resistance to B. cinerea in transgenic tomatoes expressing high amounts of MTD.
Yeast Programed Cell Death and Aging
Manuela C?rte-Real,Frank Madeo
Frontiers in Oncology , 2013, DOI: 10.3389/fonc.2013.00283
Abstract:
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