82 research outputs found
О влиянии остаточных индукций сердечников трансформаторов тока на эффективность уравновешивания плеч дифференциальной защиты
Annexin 2 has an essential role in actin-based macropinocytic rocketing
AbstractAnnexin 2 is a Ca2+ binding protein that binds to and aggregates secretory vesicles at physiological Ca2+ levels [1] and that also associates Ca2+ independently with early endosomes [2, 3]. These properties suggest roles in both exocytosis and endocytosis, but little is known of the dynamics of Annexin 2 distribution in live cells during these processes. We have used evanescent field microscopy to image Annexin 2-GFP in live, secreting rat basophilic leukemia cells and in cells performing pinocytosis. Although we found no evidence of Annexin 2 involvement in exocytosis, we observed an enrichment of Annexin 2-GFP in actin tails propeling macropinosomes. The association of Annexin 2-GFP with rocketing macropinosomes was specific because Annexin 2-GFP was absent from the actin tails of rocketing Listeria. This finding suggests that the association of Annexin 2 with macropinocytic rockets requires native pinosomal membrane. Annexin 2 is necessary for the formation of macropinocytic rockets since overexpression of a dominant-negative Annexin 2 construct abolished the formation of these structures. The same construct did not prevent the movement of Listeria in infected cells. These results show that recruitment of Annexin 2 to nascent macropinosome membranes 16656is an essential prerequisite for actin polymerization-dependent vesicle locomotion
The Arp2/3 complex is essential for the actin-based motility of Listeria monocytogenes
AbstractActin polymerisation is thought to drive the movement of eukaryotic cells and some intracellular pathogens such as Listeria monocytogenes. The Listeria surface protein ActA synergises with recruited host proteins to induce actin polymerisation, propelling the bacterium through the host cytoplasm [1]. The Arp2/3 complex is one recruited host factor [2,3]; it is also believed to regulate actin dynamics in lamellipodia [4,5]. The Arp2/3 complex promotes actin filament nucleation in vitro, which is further enhanced by ActA [6,7]. The Arp2/3 complex also interacts with members of the Wiskott–Aldrich syndrome protein (WASP) [8] family – Scar1 [9,10] and WASP itself [11]. We interfered with the targeting of the Arp2/3 complex to Listeria by using carboxy-terminal fragments of Scar1 that bind the Arp2/3 complex [11]. These fragments completely blocked actin tail formation and motility of Listeria, both in mouse brain extract and in Ptk2 cells overexpressing Scar1 constructs. In both systems, Listeria could initiate actin cloud formation, but tail formation was blocked. Full motility in vitro was restored by adding purified Arp2/3 complex. We conclude that the Arp2/3 complex is a host-cell factor essential for the actin-based motility of L. monocytogenes, suggesting that it plays a pivotal role in regulating the actin cytoskeleton
Antimicrobial activities of eugenol and cinnamaldehyde against the human gastric pathogen <i>Helicobacter pylori</i>
Background: Eradication of Helicobacter pylori is an important objective in overcoming gastric
diseases. Many regimens are currently available but none of them could achieve 100% success in
eradication. Eugenol and cinnamaldehyde that are commonly used in various food preparations are
known to possess antimicrobial activity against a wide spectrum of bacteria.
Aim: The present study was performed to assess the in vitro effects of eugenol and cinnamaldehyde against indigenous and standard H. pylori strains, their minimum inhibitory concentrations (MICs) and time course lethal effects at various pH.
Methods: A total of 31 strains (29 indigenous and one standard strain of H. pylori ATCC 26695,
one strain of E. coli NCIM 2089) were screened. Agar dilution method was used for the
determination of drug sensitivity patterns of isolates to the commonly used antibiotics and broth
dilution method for the test compounds.
Results: Eugenol and cinnamaldehyde inhibited the growth of all the 30 H. pylori strains tested, at
a concentration of 2 μg/ml, in the 9th and 12th hours of incubation respectively. At acidic pH,
increased activity was observed for both the compounds. Furthermore, the organism did not
develop any resistance towards these compounds even after 10 passages grown at sub-inhibitory
concentrations.
Conclusion: These results indicate that the two bioactive compounds we tested may prevent H.
pylori growth in vitro, without acquiring any resistance
ITIH5 mediates epigenetic reprogramming of breast cancer cells
Extracellular matrix (ECM) is known to maintain epithelial integrity. In carcinogenesis ECM degradation triggers metastasis by controlling migration and differentiation including cancer stem cell (CSC) characteristics. The ECM-modulator inter- α-trypsin inhibitor heavy chain family member five (ITIH5) was recently identified as tumor suppressor potentially involved in impairing breast cancer progression but molecular mechanisms underlying its function are still elusive
Sedimentological model of the lower middle Jurassic deposits in the south-east of Western Siberia
Understanding Factors Associated With Psychomotor Subtypes of Delirium in Older Inpatients With Dementia
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