698 research outputs found
A BIOCHEMICAL AND STRUCTURAL STUDY OF THE KINETOCHORE - CENTROMERE INTERFACE
No full textFaithful chromosome segregation during mitosis requires the dynamic interaction between spindle microtubules and kinetochores, multiprotein complexes built on centromeres.
A group of kinetochore proteins associates with centromeres throughout the cell cycle and is thus named constitutive centromere-associated network (CCAN). Biochemical and functional analyses indicate that CCAN proteins are organized in sub-complexes. However, the exact organization of these sub-complexes has not been fully elucidated to date.
The aim of my project has been the biochemical reconstitution of CCAN sub-complexes and their structural and functional characterization. In particular, this dissertation dwells upon the results I have obtained regarding three different but intrinsically related topics.
First, I present a biochemical and structural characterization of the CCAN protein CENP-M (centromere protein M), which displays the fold, but not the enzymatic activity of a G protein. In addition, I disclose its unprecedented role in the context of a quaternary complex with CENP-H, CENP-K and CENP-I and provide information about the spatial organization of this complex. The first steps towards an in vivo validation of these results are also described.
Second, I report the discovery of a direct interaction of CENP-H / CENP-K complex with CENP-C.
Third, I have been involved in establishing in the laboratory techniques for the in vitro reconstitution of recombinant nucleosomes. The production of material of good quality and quantity has recently been achieved, supporting the analysis of in vitro interactions between nucleosomes and kinetochore components. Specifically, I illustrate some preliminary observations concerning a direct interaction of Mis12 complex with nucleosomes
The pseudo GTPase CENP-M drives human kinetochore assembly
No full textBasilico, Federica et al.Kinetochores, multi-subunit complexes that assemble at the interface with centromeres, bind spindle microtubules to ensure faithful delivery of chromosomes during cell division. The configuration and function of the kinetochore–centromere interface is poorly understood. We report that a protein at this interface, CENP-M, is structurally and evolutionarily related to small GTPases but is incapable of GTP-binding and conformational switching. We show that CENP-M is crucially required for the assembly and stability of a tetramer also comprising CENP-I, CENP-H, and CENP-K, the HIKM complex, which we extensively characterize through a combination of structural, biochemical, and cell biological approaches. A point mutant affecting the CENP-M/CENP-I interaction hampers kinetochore assembly and chromosome alignment and prevents kinetochore recruitment of the CENP-T/W complex, questioning a role of CENP-T/W as founder of an independent axis of kinetochore assembly. Our studies identify a single pathway having CENP-C as founder, and CENP-H/I/K/M and CENP-T/W as CENP-C-dependent followers.AM acknowledges funding by the European Union's 7th Framework Program ERC agreement KINCON and the Integrated Project MitoSys. FH is supported by the Bavarian Research Center of Molecular Biosystems and by a LMU excellent junior grant.Peer reviewe
Draunara, installation, Federica Cellini, 2014
No full text Draunara, Federica Cellini, Ana B.K, widewalls.ch , 26/05/2014 "Washed away onto the shores of the island, migrants from Africa keep arriving to Lampedusa, a small island just off the coast of Sicily. (...) The Unstoppable Tempest Draunara takes its name from the local term for a storm that swoops over the island coming from the sea. The author of the piece draws a parallel between the tempest and the overwhelming number of people arriving from the same direction. Although the arrivals ar..
Leishmania infantum infection reduces the amyloid β42-stimulated NLRP3 inflammasome activation
No full textActivation of the NLRP3 inflammasome has been shown to play a major role in the neuroinflammation that accompanies Alzheimer’s disease (AD); interventions that down regulate the NLRP3 inflammasome could thus be beneficial in AD. Parasite infections were recently shown to be associated with improved cognitive functions in Apolipoprotein E4 (ApoE4)-expressing members of an Amazonian tribe. We verified in an in vitro model whether Leishmania infantum infection could reduce NLRP3. Results obtained in an initial experimental model in which PBMC were LPS primed and nigericin-stimulated showed that L. infantum infection significantly reduced ASC-speck formation (i.e. intracellular inflammasome proteins assembly), as well as the production of activated caspase 5 and IL-1β, but increased that of activated caspase 1 and IL-18. Moreover, L. infantum infection induced the generation of an anti-inflammatory milieu by suppressing the production of TNFα and increasing that of IL-10. These results were replicated when cells that had been LPS-primed were stimulated with Aβ42 and infected with L. infantum.. Results herein indicate that Leishmania infection favors an anti-inflammatory milieu, which includes the down-regulation of NLRP3 inflammasome activation, possibly to facilitate its survival inside host cells. A side effect of Leishmaniasis would be the hampering of neuroinflammation; this could play a protective role against AD development
Dextran-shelled oxygen-loaded nanodroplets modulate macrophages killing and inflammatory response to Enterococcus faecalis
No full textChronic wounds are associated with inflammation, infections, and hypoxic environment. Macrophages play a crucial role in wound healing removing bacteria and secreting signal molecules to coordinate tissue repair. Recently, dextran-shelled Oxygen-Loaded NanoDroplets (OLNDs) have been proposed as new tools to counteract hypoxia in chronic wounds. Here we investigated the effects of OLNDs on Enterococcus faecalis (E. faecalis) killing and the secretion of inflammatory and angiogenic factors by murine (BMDM) and human (dTHP-1, differentiated THP-1) macrophages, in normoxia and hypoxia. Both OLNDs and Oxygen-Free NanoDroplets (OFNDs) signifi-cantly increased reactive oxygen species production by BMDM in normoxia (4.1 and 4 fold increase by 10% OLNDs and OFNDs, respectively, after 120 min) and hypoxia (3.8 and 4 fold increase by 10% OLNDs and OFNDs respectively) but not by dTHP-1. Moreover, only OLNDs induced nitric oxide secretion by BMDM in normoxia. Consequently, both nanodroplets improved E. faecalis killing by BMDM in normoxia (% of killing OLNDs = 44.2%; p < 0.01; OFNDs = 41.4%; p < 0.05) and hypoxia (% of killing OLNDs = 43.1%; p < 0.01; OFNDs = 37.7%; p < 0.05), while dTHP-1-mediated killing was not affected. The secretion of the inflammatory cytokines (TNF alpha, IL-6, IL-1 beta) induced by E. faecalis infection in dTHP-1 was reduced by both types of nanodroplets, sug-gesting a novel anti-inflammatory activity of the dextran shell. Instead, the increase of VEGF induced by hypoxia was reduced only by OLNDs. These data provide new knowledge on the effects of OLNDs as innovative adjuvant in chronic wounds healing promoting bacterial killing and reducing inflammation
correction idelalisib exposure before allogenic stem cell transplantation in patients with follicular lymphoma an EBMT survey
No full textThe article “Idelalisib exposure before allogeneic stem cell transplantation in patients with follicular lymphoma: an EBMT survey”, written by Leopold Sellner, Johannes Schetelig, Linda Koster, Goda Choi, Didier Blaise, Dietrich Beelen, Fabrizio Carnevale Schianca, Jakob Passweg, Urs Schanz, Emmanuel Gyan, Federica Sora, Nicolaus Kröger, Gerald. G. Wulf, Gwendolyn Van Gorkom, Jiri Mayer, Corentin Orvain, Jean Henri Bourhis, Pavel Jindra, Victoria Potter, Francesco Zallio, Elisabeth Vandenberghe, Stephen Robinson, Patrick J. Hayden, Ibrahim Yakoub-Agha, Silvia Montoto, Peter Dreger, on behalf of the European Society for Blood and Marrow Transplantation Lymphoma and Chronic Malignancies Working Parties, was originally published Online First without Open Access. After publication in volume 55, issue 12, page 2335–2338, the author decided to opt for Open Choice and to make the article an Open Access publication. Therefore, the copyright of the article has been changed to © The Author(s) 2020 and the article is forthwith distributed under the terms of the Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder
Targeting the MET oncogene by concomitant inhibition of receptor and ligand via an antibody-“decoy” strategy
No full textMET, a master gene sustaining "invasive growth," is a relevant target for cancer precision therapy. In the vast majority of tumors, wild-type MET behaves as a "stress-response" gene and relies on the ligand (HGF) to sustain cell "scattering," invasive growth and apoptosis protection (oncogene "expedience"). In this context, concomitant targeting of MET and HGF could be crucial to reach effective inhibition. To test this hypothesis, we combined an anti-MET antibody (MvDN30) inducing "shedding" (i.e., removal of MET from the cell surface), with a "decoy" (i.e., the soluble extracellular domain of the MET receptor) endowed with HGF-sequestering ability. To avoid antibody/decoy interaction-and subsequent neutralization-we identified a single aminoacid in the extracellular domain of MET-lysine 842-that is critical for MvDN30 binding and engineered the corresponding recombinant decoyMET (K842E). DecoyMET(K842E) retains the ability to bind HGF with high affinity and inhibits HGF-induced MET phosphorylation. In HGF-dependent cellular models, MvDN30 antibody and decoyMET(K842E) used in combination cooperate in restraining invasive growth, and synergize in blocking cancer cell "scattering." The antibody and the decoy unbridle apoptosis of colon cancer stem cells grown in vitro as spheroids. In a preclinical model, built by orthotopic transplantation of a human pancreatic carcinoma in SCID mice engineered to express human HGF, concomitant treatment with antibody and decoy significantly reduces metastatic spread. The data reported indicate that vertical targeting of the MET/HGF axis results in powerful inhibition of ligand-dependent MET activation, providing proof of concept in favor of combined target therapy of MET "expedience.
Cooking pots from Alassa Pano Mantilaris and Paliotaverna
No full textThis final report on the 1984–2000 investigations at Alassa begins with the presentation of the rescue excavations of the settlement (Chapter 2) and tombs (Chapter 3) at Pano Mantilaris. This is followed by the account of the elite architecture and associated finds uncovered at Paliotaverna (Chapter 4) and a detailed description and discussion of the remarkable seal impressions found on many of the Alassa pithoi (Chapter 5). In-depth studies of the Alassa pithoi and all of the other pottery found at the site are presented in Chapters 6 and 7 by Priscilla Keswani and Ariane Jacobs, respectively. Federica Spagnoli presents a report on cooking pots in chapter 7. Reports by other specialists on a variety of topics may be found in the 10 appendices: the cylinder and stamp seals (Aruz), metallurgical finds (Kassianidou and Van-Brempt), marked pottery (Hirschfeld), C14 dates (Manning), human remains (Lorentz), faunal remains (Croft), coins (Destrooper), ground stone objects (Souter), and archaeometric studies of the pithoi (Nodarou) and other pottery (Jacobs et al.). The results from all of these studies are integrated within the conclusions that the author offers in Chapter 8 regarding the chronology and importance of Alassa within the broader cultural and sociopolitical context of LBA Cyprus
4-Aminoquinoline quinolizidinyl- and quinolizidinylalkyl-derivatives with antimalarial activity
No full textA set of quinolizidinyl and quinolizidinylalkyl derivatives of 4-amino-7-chloroquinoline and of 9-amino-6-chloro-2-methoxyacridine were prepared and tested in vitro against CQ-sensitive (D-10) and CQ-resistant (W-2) strains of Plasmodium falciparum. All compounds but one exerted significant antimalarial activity. Some of the quinolizidine derivatives were from 5 to 10 times more active than chloroquine on the CQ-resistant strain. No toxicity against mammalian cells was observed
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