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941.
Microenvironment‐induced PIM kinases promote CXCR4‐triggered mTOR pathway required for chronic lymphocytic leukaemia cell migration
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Emilia Białopiotrowicz Patryk Górniak Monika Noyszewska‐Kania Bartosz Puła Hanna Makuch‐Łasica Grażyna Nowak Aleksandra Bluszcz Maciej Szydłowski Ewa Jabłonska Karolina Piechna Tomasz Sewastianik Anna Polak Ewa Lech‐Marańda Bożena K. Budziszewska Maja Wasylecka‐Juszczyńska Katarzyna Borg Krzysztof Warzocha Wojciech Czardybon Michał Gałęzowski Renata Windak Krzysztof Brzózka Przemysław Juszczyński 《Journal of cellular and molecular medicine》2018,22(7):3548-3559
Lymph node microenvironment provides chronic lymphocytic leukaemia (CLL) cells with signals promoting their survival and granting resistance to chemotherapeutics. CLL cells overexpress PIM kinases, which regulate apoptosis, cell cycle and migration. We demonstrate that BCR crosslinking, CD40 stimulation, and coculture with stromal cells increases PIMs expression in CLL cells, indicating microenvironment‐dependent PIMs regulation. PIM1 and PIM2 expression at diagnosis was higher in patients with advanced disease (Binet C vs. Binet A/B) and in those, who progressed after first‐line treatment. In primary CLL cells, inhibition of PIM kinases with a pan‐PIM inhibitor, SEL24‐B489, decreased PIM‐specific substrate phosphorylation and induced dose‐dependent apoptosis in leukaemic, but not in normal B cells. Cytotoxicity of SEL24‐B489 was similar in TP53‐mutant and TP53 wild‐type cells. Finally, inhibition of PIM kinases decreased CXCR4‐mediated cell chemotaxis in two related mechanisms‐by decreasing CXCR4 phosphorylation and surface expression, and by limiting CXCR4‐triggered mTOR pathway activity. Importantly, PIM and mTOR inhibitors similarly impaired migration, indicating that CXCL12‐triggered mTOR is required for CLL cell chemotaxis. Given the microenvironment‐modulated PIM expression, their pro‐survival function and a role of PIMs in CXCR4‐induced migration, inhibition of these kinases might override microenvironmental protection and be an attractive therapeutic strategy in this disease. 相似文献
942.
Kwiatkowska Anna Justyna Spalik Krzysztof Michalak Elżbieta Palińska Anna Panufnik Dorota 《Plant Ecology》1997,129(1):1-10
The change in the species richness following a gradual invasion of Carpinus betulus in the patch of oak forest (Potentillo albae-Quercetum) in Biaowiea was studied between years 1980 and 1994. Species richness and species deletion were compared to the spatial variation in the density and size of C. betulus individuals. The study showed that, in a microscale, (1) the rate of deletion of heliophilous species was similar to that of shade-tolerant ones and was c. 2 species per 4 m2 per 10 years, (2) species richness was negatively correlated with the density and size of C. betulus saplings recruited to the shrub layer, (3) species deletion was positively correlated with the number of saplings in the shrub layer. The results support the hypothesis that the invasion of C. betulus is a proximate cause of the decline of Potentillo albae-Quercetum, and in a microscale, it has three stages: (a) initial colonisation of the ground layer by the seedlings, (b) recruitment of juveniles to the shrub layer, deterioration of light conditions and rapid deletion of species, and (c) closure of the canopy and deletion of remaining heliophilous species and vulnerable shade-tolerant species. Nomenclature: follows Ehrendorfer (1973) and Matuszkiewicz (1981). 相似文献
943.
Elżbieta Galoch Marlena Zielińska Elżbieta Burkacka-Łaukajtys 《Acta Physiologiae Plantarum》1998,20(4):399-403
The level of IAA and ABA in lateral buds of birch shoots 24 h and 5 days after the decapitation of the apical bud was determined.
Twenty four hours after decapitation, when visible signs of outgrowth of lateral buds were not observed yet, an increase in
the level of IAA and a decrease of ABA, as compared with the buds of non-decapitated shoots, was found.
Five days later, when lateral buds were in the period of intensive outgrowth, a decrease in the levels of IAA and ABA was
observed.
It has been suggested that removing the source of auxin, by the decapitation of the apical bud makes possible the lateral
buds to undertake the synthesis of their own auxin. It could lead to the decrease in the content of ABA. These all events
could create suitable conditions for the outgrowth of lateral shoots. 相似文献
944.
Antoni Murkowski Grzegorz Bartoszewski Elżbieta Skórska 《Acta Physiologiae Plantarum》1998,20(4):465-470
The parameters of chlorophyll a fluorescence induction were measured: Fv/Fm, Sc/Fm, Rfd and coefficient of Ld delayed luminescence decay kinetics, related with a course of primary photosynthesis reactions on leaves of strawberry plants,
cultured in vitro by means of the micropropagation methods. Strawberry plants cv. Ananasowa from in vitro cultures in optimal condition show significantly higher values of luminescence parameters indicating better condition of
plants of this variety in comparison with the variety Senga Sengana. After temperature lowering, however, these values were
more reduced than for plants of Senga Sengana, which can be interpreted as higher susceptibility of this variety to chill.
Addition of BAP caused disturbance of primary photosynthesis reactions rate, particularly in lower temperature. Auxin 2,4-D
had no effect on the luminescence parameters in comparison with control cultures. Dehydration stress strongly diminished the
values of measured parameters for Ananasowa variety what indicates the inhibition of primary photosynthesis reaction in leaves.
The old culture of Senga Sengana variety showed higher tolerance on linuron in comparison with the new one. 相似文献
945.
Modrý David Koudela Břetislav Al-Oran Ratib M. Amr Zuhair S. Doležel David 《Systematic parasitology》1998,39(1):45-48
Faecal samples from 17 fan-footed geckoes Ptyodactylus puiseuxi Boutan were examined for coccidian parasites. Five geckoes (29%) were found to be passing oöcysts of the genus Isospora Schneider. Comparison with other members of the genus Isospora indicates that the coccidian found represents a new species. Sporulated oöcysts of I. ptyodactyli n. sp. are spherical or subspherical, 22.1 (19.0–24.0) × 21.2 (18.0–23.0) µm, with a shape-index (length/width) of 1.04; and a smooth and bilayered oöcyst wall, 1.0–1.5 µm thick. A micropyle, oöcyst residuum and polar granule are absent. The sporocysts are ellipsoidal, 12.2 (11.0–14.0) × 8.0 (7.5–9.0) µm, with a shape index of 1.5 (1.4–1.9). Stieda and substieda bodies are present, the Stieda body being knob-like and the substieda body spherical to subspherical. A sporocyst residuum is present and composed of numerous granules of different size scattered among the sporozoites. The sporozoites are vermiform, with a slightly granulated surface appearance, and are arranged head to tail within the sporocyst. Most oöcysts have still to sporulate when excreted; sporulation was completed within 12 h at 25 °C. Endogenous development occurs inside the nuclei of enterocytes in the small intestine. 相似文献
946.
During the past decade, significant progress has been made in the development of methods for the preparation of plant chromosome suspensions suitable for flow cytometric analysis. In addition to successful classification of chromosomes (flow karyotyping), sorting of single chromosome types with a high degree of purity was reported in several plant species. Sorted chromosomes were used for the establishment of chromosome-specific DNA libraries and for gene mapping. The results confirmed the potential of plant flow cytogenetics and form a solid basis for further progress in this area. This article reviews its current status, analyzes major problems, and assesses future directions. 相似文献
947.
We have compared effects of dimethylsulfoxide (Me2SO) and two polyols on the Ca2+-ATPase purified from human erythrocytes. As studied under steady-state conditions over a broad solute concentration range and temperature, Me2SO, glycerol, and xylitol do not inhibit the Ca2+-ATPase activity; this is in contrast to numerous other organic solutes that we have investigated. Under specific experimental conditions, Me2SO (but not glycerol) substantially increases Ca2+-ATPase activity, suggesting a possible facilitation of enzyme oligomerization. The activation is more pronounced at low Ca2+ concentrations. In contrast to glycerol, Me2SO shows no protective effect on enzyme structure as assessed by determining residual Ca2+-ATPase activity after exposing the enzyme to thermal denaturation at 45°C. Under these conditions several other organic solutes strongly enhance the denaturating effect of temperature. Because of the temperature dependence of its effect on the Ca2+-ATPase activity we believe that Me2SO activates the Ca2+-ATPase by indirect water-mediated interactions. 相似文献
948.
Иэ распределения активности в отдельных отщеплениях эритромицина после прибавления уксусной кислоты, меченой 1-С14 и 2-С14, вытекает, что уксусная кислота не является прямым предшественником дезозамина и кладинозы. Распределение активности в пропион-альдегиде, изолированном из эритронолида, показывает, что уксусная кислота перед своим включением в эритромицин проходит цикл, подобный пиклу дикарбоновых или трикарбоновых кислот. 相似文献
949.
950.