排序方式: 共有96条查询结果,搜索用时 15 毫秒
11.
Dimitrios Tsiantoulas Thomas Perkmann Taras Afonyushkin Andreas Mangold Thomas A. Prohaska Nikolina Papac-Milicevic Vincent Millischer Caroline Bartel Sohvi H?rkk? Chantal M. Boulanger Sotirios Tsimikas Michael B. Fischer Joseph L. Witztum Irene M. Lang Christoph J. Binder 《Journal of lipid research》2015,56(2):440-448
Oxidation-specific epitopes (OSEs) present on apoptotic cells and oxidized low density lipoprotein (OxLDL) represent danger-associated molecular patterns that are recognized by different arcs of innate immunity, including natural IgM antibodies. Here, we investigated whether circulating microparticles (MPs), which are small membrane vesicles released by apoptotic or activated cells, are physiological carriers of OSEs. OSEs on circulating MPs isolated from healthy donors and patients with ST-segment elevation myocardial infarction (STE-MI) were characterized by flow cytometry using a panel of OSE-specific monoclonal antibodies. We found that a subset of MPs carry OSEs on their surface, predominantly malondialdehyde (MDA) epitopes. Consistent with this, a majority of IgM antibodies bound on the surface of circulating MPs were found to have specificity for MDA-modified LDL. Moreover, we show that MPs can stimulate THP-1 (human acute monocytic leukemia cell line) and human primary monocytes to produce interleukin 8, which can be inhibited by a monoclonal IgM with specificity for MDA epitopes. Finally, we show that MDA+ MPs are elevated at the culprit lesion site of patients with STE-MI. Our results identify a subset of OSE+ MPs that are bound by OxLDL-specific IgM. These findings demonstrate a novel mechanism by which anti-OxLDL IgM antibodies could mediate protective functions in CVD. 相似文献
12.
Silviya Velichkova Wolkerstorfer Astrid Wonisch Tatiana Stankova Nikolina Tsvetkova Michael Tausz 《Trees - Structure and Function》2011,25(6):1043-1052
Seasonal changes in physiological and biochemical parameters were studied in 35-, 55- and 140-year-old trees of Turkey oak
(Quercus cerris L.) and Hungarian oak (Q. frainetto Ten.), growing in natural stands in Eastern Balkan Mountains (Bulgaria). During the seasonal drought period (August), assimilation
activity, transpiration rate, stomatal conductance and water potential had a seasonal minimum in all the studied tree ages
and species. The foliar concentrations of glutathione, ascorbate, α-tocopherol, as well as photosynthetic pigments in oak
leaves were significantly affected by season. With the increasing age of the studied trees, we observed a decrease of the
physiological activity and an increase of the antioxidants’ accumulation. Both the species were drought tolerant and anisohydric,
where Q. frainetto exhibited higher rates of gas exchange than Q. cerris. Moreover, they differed in the extent of increase in the foliar antioxidants and carotenoids. 相似文献
13.
Kmonícková E Canová NK Farghali H Holý A Zídek Z 《Biomedical papers of the Medical Faculty of the University Palacky, Olomouc, Czechoslovakia》2005,149(2):321-324
Interference of thapsigargin (TG), an inhibitor of endoplasmic reticulum Ca(2+) ATPase, with immune reactivity of murine macrophages was investigated under conditions in vitro. The activation of cells with lipopolysaccharide (LPS), interferon-(gamma) (IFN-(gamma)), and with acyclic nucleoside phosphonate N(6)-isobutyl-9-[2-(phosphonomethoxy)ethyl]- 2,6-diaminopurine (N(6)-isobutyl-PMEDAP) resulted in enhanced production of cytokines TNF-alpha, IL-10, chemokines RANTES/CCL5 and MIP-1alpha/CCL3, as well as in substantially augmented production of nitric oxide (NO) triggered by IFN-(gamma). The effects were in a dual mode of action influenced by TG (1 microM). While TG upregulated secretion of TNF-alpha, it inhibited secretion of IL-10 and RANTES. The immune-stimulated secretion of MIP-1alpha remained virtually unaffected, though TG on its own activated expression of MIP-1alpha in macrophages. The high-output NO production induced by IFN-(gamma), high concentrations of LPS, or by combination of IFN-(gamma) plus LPS or N(6)-isobutyl-PMEDAP was inhibited by TG. On the other hand, production of NO which was marginally activated by low concentration of LPS was upregulated by TG. 相似文献
14.
We have studied the effects of high-density lipoprotein (HDL) on rat heart (H9c2) and skeletal (L6) myoblasts using two-dimensional gel electrophoresis and tandem mass spectrometry. Gels generated from control cells and cells treated with 250 microg/mL HDL showed significant differences in the 7-10 pI region and the 30-50 kDa mass region. In particular, the membrane binding protein, annexin II, the voltage-dependent anion channel, glyceraldehyde-3-phosphate dehydrogenase and other glycolytic proteins are differentially expressed. 相似文献
15.
Evolution of atrazine-degrading capabilities in the environment 总被引:2,自引:0,他引:2
Nikolina Udikovi?-Koli? Colin Scott Fabrice Martin-Laurent 《Applied microbiology and biotechnology》2012,96(5):1175-1189
Since their first introduction in the mid 1950s, man-made s-triazine herbicides such as atrazine have extensively been used in agriculture to control broadleaf weed growth in different crops, and thus contributed to improving crop yield and quality. Atrazine is the most widely used s-triazine herbicide for the control of weeds in crops such as corn and sorghum. Although atrazine was initially found to be slowly and partially biodegradable, predominantly by nonspecific P450 monoxygenases which do not sustain microbial growth, microorganisms gradually evolved as a result of repeated exposure, started using it as a growth substrate and eventually succeeded in mineralizing it. Within three decades, an entirely new hydrolase-dependent pathway for atrazine mineralization emerged and rapidly spread worldwide among genetically different bacteria. This review focuses on the enzymes involved in atrazine mineralization and their evolutionary histories, the genetic composition of microbial populations involved in atrazine degradation and the biotechnologies that have been developed, based on these systems, for the bioremediation of atrazine contamination in the environment. 相似文献
16.
The activities of acid and alkaline phosphatases along with phosphorus content in leaves of European beech (Fagus sylvatica L.) were studied for a period from April to October. The phosphorus content of beech leaves was highest in April, at the
beginning of the vegetation period; from May to October it was twofold lower than in April. Acid phosphatase activity (per
unit fresh weight) in leaves collected from the middle part of the crown decreased significantly in May and July compared
to the enzyme activity in April. In both the low and middle parts of the crown, the acid phosphatase activity had a peak in
August, and thereafter decreased in September and October. No correlations between acid phosphatase activity and phosphorus
concentrations were found. Alkaline phosphatase activity was very low and in some cases near the detection limit during the
whole observation period. 相似文献
17.
18.
Anna B. Epelbaum - s Rostislav R. Borisov Nikolina P. Kovatcheva 《Marine and Freshwater Behaviour and Physiology》2007,40(1):35-44
Phototactic responses of light-adapted zoeae IV, glaucothoe, and first stage juveniles of the red king crab to three intensities of white light were quantitatively measured under laboratory conditions. All stages observed were photopositive to all light intensities tested, except for late glaucothoe (10 days since moulting) which did not respond to light stimuli. Phototactic response changed in the early life history of the red king crab. The extent of photopositive movement decreased after each metamorphosis. Peak phototactic response in zoea IV were observed at a light intensity of 1.9 × 1013 q cm-2 s-1, in early glaucothoe at 1.1 × 1010 q cm-2 s-1 and in juveniles at 1.3 × 109 q cm-2 s-1. The data on behavioural responses to light may provide a better understanding of the early life history, survival and recruitment of the red king crab and assist the development of feasible methods and techniques for aquaculture of this species. 相似文献
19.
Kiril Tishinov Nikolina Stambolieva Svetla Petrova Boris Galunsky Peter Nedkov 《Acta Physiologiae Plantarum》2009,31(1):199-205
The sunflower seed (Helianthus annuus L.) major peptidase was purified to molecular homogeneity. It is an 80 kDa enzyme with pI of 4.6 and optimal activity at
pH 7.5–8.0 and 45–50°C. It is a thiol-dependent aminopeptidase hydrolyzing peptides in a step-by-step manner as cleaving after
the N-terminal amino acid residue of the substrate. It requires substrate acyl parts with a free amino group in either α-
or β-position and l-configuration of the adjacent carbon atom. The enzyme prefers amino acid residues with bulky hydrophobic side chains at P1-position and its catalytic efficacy is affected by the structure of both P1 and P1′ parts of the substrate. 相似文献
20.
Charis Liapi Apostolos Zarros Stamatios Theocharis Hussam Al-Humadi Foteini Anifantaki Elena Gkrouzman Zois Mellios Nikolina Skandali Stylianos Tsakiris 《Biometals》2009,22(2):329-335
Lanthanum (La) is a rare earth element that is widely used for industrial, medical and agricultural purposes. Its neurotoxic
effects are linked to its physical and chemical properties and its interaction with certain trace elements and membrane-bound
enzymes. The aim of this study was to investigate the effects of short-term La-administration (as LaCl3, 53 mg/kg) on the adult rat whole brain total antioxidant status (TAS) and the activities of acetylcholinesterase (AChE),
Na+,K+-ATPase and Mg2+-ATPase, as well as the potential effect of the co-administration of the antioxidant l-cysteine (Cys, 7 mg/kg) on the above parameters. Twenty-eight male Wistar rats were divided into four groups: A (saline-treated
control), B (La), C (Cys),and D (La and Cys). All rats were treated once daily with intraperitoneal injections of the tested
compounds, for 1-week. Rats were sacrificed by decapitation and the above mentioned parameters were measured spectrophotometrically.
Rats treated with La exhibited a significant reduction in brain TAS (−36%, P < 0.001, BvsA), that was partially limited by the co-administration of Cys (−13%, P < 0.01, DvsA), while Cys (group C) had no effect on TAS. The rat brain AChE activity was found significantly increased by
both La (+23%, P < 0.001, BvsA) and Cys (+59%, P < 0.001, CvsA), while it was adjusted to control levels by the co-administration of La and Cys. The activity of rat brain
Na+,K+-ATPase was significantly decreased by La-administration (−28%, P < 0.001, BvsA), while Cys supplementation could not reverse this decrease. The activity of Mg2+-ATPase exhibited a slight but statistically significant reduction due to La (−8%, P < 0.01, BvsA), that was further reduced by Cys co-administration (−25%, P < 0.001, DvsA). The above findings suggest that La short-term in vivo administration causes a statistically significant decrease
in the rat brain TAS and an increase in AChE activity. Both effects can be, partially or totally, reversed into control levels
by Cys co-administration, which could thus be considered for future applications as a neuroprotective agent against chronic
exposure to La. The activities of Na+,K+- and Mg2+-ATPase that were inhibited by La, could not be reversed by Cys co-administration. A role for the already reported concentration-dependent
interaction of La with Ca-binding sites (such as Ca2+-ATPase) might be considered for certain of the above phenomena. 相似文献