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71.
It was shown that tobacco leaf treatment with 100 mM H2O2 increased their content of endogenous H2O2 and activities of catalase and hydrolases (acid phosphatase, proteases, and RNase) and also caused various changes in the cell structure. In this case, programmed cell death (PCD) occurred in some cells, which was observed as chromatin condensation, cytoplasm collapse, etc. In the meantime, many cells displayed organelle activation rather than PCD. It is suggested that cells that undergo H2O2-dependent PCD release signaling molecules inducing protective mechanisms against oxidative stress in neighboring cells not exhibiting PCD. 相似文献
72.
Cuiqing Liu Rajagopal Desikan Zhekang Ying Liubov Gushchina Thomas Kampfrath Jeffrey Deiuliis Aixia Wang Xiaohua Xu Jixin Zhong Xiaoquan Rao Qinghua Sun Andrei Maiseyeu Sampath Parthasarathy Sanjay Rajagopalan 《PloS one》2012,7(12)
Inflammation and oxidative stress play fundamental roles in the pathogenesis of atherosclerosis. Myeloperoxidase has been extensively implicated as a key mediator of inflammatory and redox-dependent processes in atherosclerosis. However, the effect of synthetic myeloperoxidase inhibitors on atherosclerosis has been insufficiently studied. In this study, ApoE−/− mice were randomized to low- and high-dose INV-315 groups for 16 weeks on high-fat diet. INV-315 resulted in reduced plaque burden and improved endothelial function in response to acetylcholine. These effects occurred without adverse events or changes in body weight or blood pressure. INV-315 treatment resulted in a decrease in iNOS gene expression, superoxide production and nitrotyrosine content in the aorta. Circulating IL-6 and inflammatory CD11b+/Ly6Glow/7/4hi monocytes were significantly decreased in response to INV-315 treatment. Acute pretreatment with INV-315 blocked TNFα-mediated leukocyte adhesion in cremasteric venules and inhibited myeloperoxidase activity. Cholesterol efflux was significantly increased by high-dose INV-315 via ex-vivo reverse cholesterol transport assays. Our results suggest that myeloperoxidase inhibition may exert anti-atherosclerotic effects via inhibition of oxidative stress and enhancement of cholesterol efflux. These findings demonstrate a role for pharmacologic modulation of myeloperoxidase in atherosclerosis. 相似文献
73.
A. V. Reunov I. V. Gnutova L. A. Lapshina V. P. Nagorskaya V. F. Tolkach 《Biology Bulletin》2006,33(4):409-415
Accumulation of considerable amounts of viral particles has been demonstrated in parenchymal cells of young leaves in tobacco cultivar Samsun systemically infected with any of studied tobacco mosaic virus (TMV) strains isolated from pepper (TMV-p), tomato (TMV-t), and eggplant (TMV-e). Abnormal (swollen and thin) virions were found, which points to their destruction. Cell infection with all studied strains was accompanied by the activation of the lysosomal compartment manifested as formation of nascent dictyosomes, elements of smooth endoplasmic reticulum, cytoplasmic vacuoles, various vesicles, invaginated mitochondria, and multivesicular bodies. The studied viral strains could be arranged in the following sequence according to the degree of lysosomal compartment stimulation and induction of intracellular lytic processes mediating the destruction of viral particles and cell structures: TMV-p > TMV-e > TMV-t. 相似文献
74.
Ostracod diversity and abundance was studied in 10 different types of water bodies of Belarus (bogs, brooks, canals, oxbows,
ponds, reservoirs, rivers, springs, shoal of lake and temporary pools). Hydrochemical variables, sediment, and vegetation
were analyzed. In total 156 different localities were investigated. Habitat diversity was based mainly upon the closely correlated
hydrochemical variables of mineralization (hardness total and carbonate, conductivity, total value of dissolved substances),
although bottom, vegetation characteristics and other factors (pH, dissolved oxygen, nutrients) were also significant. The
ostracods found included 62 species in 27 genera comprising 8 cosmopolitan, 17 Holarctic, 13 Palearctic species; 21 of these
species are known from central and southern Europe and adjacent areas, while 3 are characteristic for eastern Europe. The
distribution of freshwater ostracod assemblages reflected the habitat and depended on water body type. Heterogeneous oxbows
and temporary pools supported 37 species, while other types of pool maintained only 27–14 species. The population density
of different species varied from 0.5 to more than 10 000 ind./m2. Indices of local alpha diversity were significantly correlated with the number of species and temperature and were maximal
in heterogeneous habitats. The variation of population density was not connected with habitat patterns but appeared to be
regulated by the biotic interactions in the community. Habitat diversity, verified by the beta-diversity indices, enabled
us to find localities with a similar heterogeneity level and species richness. Beta-diversity values were independent of species
number as well as abundance but a significant positive correlation (p < 0.05) was found with temperature, pH and dissolved oxygen. This index probably reflected the general patterns of different
localities. 相似文献
75.
L. A. Lapshina A. V. Reunov V. P. Nagorskaya T. N. Zvyagintseva N. M. Shevchenko 《Cell and Tissue Biology》2009,3(4):381-386
The accumulation of potato virus X (PVX) in mesophyll cells of detached Datura stramonium L. leaves treated with fucoidan from brown algae Fucus evanescens C. Ag. have been evaluated by electron microscopy during the early infection period (three days after infection). It was
found that cells of the leaves treated with fucoidan 24 h before infection accumulated virus less than untreated control.
Ultrastructure-morphometric assay showed that fucoidan treatment causes an increase in the protein-synthesizing capability
of cells (nucleolus dimention and amount of both mitochondria and rough endoplasmic reticulum membranes increased). At the
same time, fucoidan treatment slightly activates the lytic compartment, which leads to the destruction of virus particles.
Therefore, it may be considered that fucoidan induces a cellular defense mechanism that limits virus accumulation. Stimulation
by the fucoidan of the formation of PVX-specific laminar structures able to bind virus particles may be another antiviral
cell defense mechanism induced by the virus that prevents PVX reproduction and its intra- and intercellular transport. 相似文献
76.
Although endosomal compartments have been suggested to play a role in unconventional protein secretion, there is scarce experimental evidence for such involvement. Here we report that recycling endosomes are essential for externalization of cytoplasmic secretory protein tissue transglutaminase (tTG). The de novo synthesized cytoplasmic tTG does not follow the classical ER/Golgi-dependent secretion pathway, but is targeted to perinuclear recycling endosomes, and is delivered inside these vesicles prior to externalization. On its route to the cell surface tTG interacts with internalized β1 integrins inside the recycling endosomes and is secreted as a complex with recycled β1 integrins. Inactivation of recycling endosomes, blocking endosome fusion with the plasma membrane, or downregulation of Rab11 GTPase that controls outbound trafficking of perinuclear recycling endosomes, all abrogate tTG secretion. The initial recruitment of cytoplasmic tTG to recycling endosomes and subsequent externalization depend on its binding to phosphoinositides on endosomal membranes. These findings begin to unravel the unconventional mechanism of tTG secretion which utilizes the long loop of endosomal recycling pathway and indicate involvement of endosomal trafficking in non-classical protein secretion. 相似文献
77.
L. A. Lapshina A. V. Reunov V. P. Nagorskaya O. P. Shestak V. L. Novikov 《Applied Biochemistry and Microbiology》2013,49(1):59-63
The activity of hydrolases (protease, RNase) in uninfected and tobacco mosaic virus-infected tobacco leaves of the Samsun variety, untreated and treated with disodium salt of 2-acetyl-4-hydroxycarbonyl-methylthio-5-chlorocyclopent-4-en-1,3-dione (DS), was determined. It was shown that treatment of leaves with this compound significantly increased the activity of hydrolases in them compared to untreated leaves. In infected leaves treated with DS one day before infection, along with an increased level of hydrolases, one revealed more viral particles exposed to destructive changes in infected, rather than untreated, leaves. It is assumed that the DS-caused activation of hydrolases promotes the destruction of viral particles and is therefore one of the cell defense mechanisms induced by this compound that prevents the intracellular accumulation of virus. 相似文献
78.
Lo?c Treffel Liubov Dmitrieva Guillemette Gauquelin-Koch Marc-Antoine Custaud Stéphane Blanc Claude Gharib Catherine Millet 《PloS one》2016,11(2)
The objective of the study was to determine the influence of simulated microgravity by exposure to dry immersion on the craniomandibular system. Twelve healthy male volunteers participated in a 3-day dry immersion study. Before and immediately after exposure we measured maximal bite force using piezoresistive sensors. The mechanical properties of the jaw and cervical muscles were evaluated before, during, and after dry immersion using MyotonPRO. Because recent studies reported the effects of jaw motor activity on the postural stability of humans, stabilometric measurements of center of pressure were performed before and after dry immersion in two mandibular positions: rest position without jaw clenching, and intercuspidal position during voluntary teeth clenching. Results revealed no significant changes of maximal bite force after dry immersion. All postural parameters were significantly altered by dry immersion. There were however no significant differences in stabilometric data according to mandibular position. Moreover the masseter tonicity increased immediately after the end of dry immersion period. Dry immersion could be used as a valid model for studying the effects of microgravity on human subjects. However, 3 days appear insufficient in duration to evaluate the effects of weightlessness on maximal bite force. Our research suggests a link between postural disturbance after dry immersion and masseter tonicity. 相似文献
79.
Inhibition of ERK1/2 signaling prevents epileptiform behavior in rats prone to audiogenic seizures 下载免费PDF全文
Margarita V. Glazova Liubov S. Nikitina Kirill A. Hudik Olga D. Kirillova Nadezhda A. Dorofeeva Anatoly A. Korotkov Elena V. Chernigovskaya 《Journal of neurochemistry》2015,132(2):218-229
It has recently been proposed that extracellular signal‐regulated kinases 1 and 2 (ERK1/2) are one of the factors mediating seizure development. We hypothesized that inhibition of ERK1/2 activity could prevent audiogenic seizures by altering GABA and glutamate release mechanisms. Krushinsky–Molodkina rats, genetically prone to audiogenic seizure, were recruited in the experiments. Animals were i.p. injected with an inhibitor of ERK1/2 SL 327 at different doses 60 min before audio stimulation. We demonstrated for the first time that inhibition of ERK1/2 activity by SL 327 injections prevented seizure behavior and this effect was dose‐dependent and correlated with ERK1/2 activity. The obtained data also demonstrated unchanged levels of GABA production, and an increase in the level of vesicular glutamate transporter 2. The study of exocytosis protein expression showed that SL 327 treatment leads to downregulation of vesicle‐associated membrane protein 2 and synapsin I, and accumulation of synaptosomal‐associated protein 25 (SNAP‐25). The obtained data indicate that the inhibition of ERK1/2 blocks seizure behavior presumably by altering the exocytosis machinery, and identifies ERK1/2 as a potential target for the development of new strategies for seizure treatment.
80.
Hublin JJ Pääbo S Derevianko AP Doronichev VB Golovanova LV Friess M Froment A Hoffmann A Jillani Kachache NE Kullmer O Lordkipanidze D Moncel MH Potts R Radovcic J Rak YZ Richards M Méndez JR Rosas A Schmauder M Schmitz RW Semal P Smith T Tafuri MA Tattersall I Tournepiche JF Toussaint M Vassiliev S Vialet A White T Ziegler R 《Journal of human evolution》2008,55(4):756-757