72 research outputs found
Quantitative assessment of the degradation of aggregated TDP-43 mediated by the ubiquitin proteasome system and macroautophagy
No full textAmyotrophic lateral sclerosis and frontotemporal lobar degeneration with ubiquitin-positive inclusions are neurodegenerative disorders that share the cytosolic deposition of TDP-43 (TAR DNA-binding protein 43) in the CNS. TDP-43 is well known as being actively degraded by both the proteasome and macroautophagy. The well-documented decrease in the efficiency of these clearance systems in aging and neurodegeneration, as well as the genetic evidence that many of the familial forms of TDP-43 proteinopathies involve genes that are associated with them, suggest that a failure of these protein degradation systems is a major factor that contributes to the onset of TDP-43-associated disorders. Here, we inserted preformed human TDP-43 aggregates in the cytosol of murine NSC34 and N2a cells in diffuse form and observed their degradation under conditions in which exogenous TDP-43 is not expressed and endogenous nuclear TDP-43 is not recruited, thereby allowing a time zero to be established in TDP-43 degradation and to observe its disposal kinetically and analytically. TDP-43 degradation was observed in the absence and presence of selective inhibitors and small interfering RNAs against the proteasome and autophagy. We found that cytosolic diffuse aggregates of TDP-43 can be distinguished in 3 different classes on the basis of their vulnerability to degradation, which contributed to the definition-with previous reports-of a total of 6 distinct classes of misfolded TDP-43 species that range from soluble monomer to undegradable macroaggregates. We also found that the proteasome and macroautophagy-degradable pools of TDP-43 are fully distinguishable, rather than in equilibrium between them on the time scale required for degradation, and that a significant crosstalk exists between the 2 degradation processes.-Cascella, R., Fani, G., Capitini, C., Rusmini, P., Poletti, A., Cecchi, C., Chiti, F. Quantitative assessment of the degradation of aggregated TDP-43 mediated by the ubiquitin proteasome system and macroautophagy
L'incontro con Aldo Capitini
No full textIl saggio compie un'analisi del rapporto culturale e di amicizia tra Don Milani e Aldo Capitini, mettendone in evidenza gli aspetti comuni, ma anche divergenti, a livelloi pedagogico
Note di etica e di religione.
No full textdattiloscritto (a mano, a matita: Scritti di Aldo Capitini portati a Vicenza nel 1942 da A. Giuriolo
Full-length TDP-43 and its C-terminal domain form filaments in vitro having non-amyloid properties
No full textAccumulation of ubiquitin-positive, tau- and α-synuclein-negative intracellular inclusions of TDP-43 in the central nervous system represents the major hallmark correlated to amyotrophic lateral sclerosis (ALS) and frontotemporal lobar degeneration with ubiquitin-positive inclusions (FTLD-U). Such inclusions have variably been described as amorphous aggregates or more structured deposits having amyloid properties. Here we have purified full-length TDP-43 (FL TDP-43) and its C-terminal domain (Ct TDP-43) to investigate the morphological, structural and tinctorial features of aggregates formed in vitro by them at pH 7.4 and 37 °C. AFM images indicate that both protein variants show a tendency to form filaments. Moreover, we show that both FL TDP-43 and Ct TDP-43 filaments possess a largely disordered secondary structure, as ascertained by far-UV circular dichroism and Fourier transform infra-red spectroscopy, do not bind Congo red and induce a very weak increase of thioflavin T fluorescence, indicating the absence of a clear amyloid-like signature
Backbone NMR assignments of HypF-N under conditions generating toxic and non-toxic oligomers
No full textThe HypF protein is involved in the maturation and regulation of hydrogenases. The N-terminal domain of HypF (HypF-N) has served as a key model system to study the pathways of protein amyloid formation and the nature of the toxicity of pre-fibrilar protein oligomers. This domain can aggregate into two forms of oligomers having significantly different toxic effects when added to neuronal cultures. Here, NMR assignments of HypF-N backbone resonances are presented in its native state and under the conditions favouring the formation of toxic and non-toxic oligomers. The analyses of chemical shifts provide insights into the protein conformational state and the possible pathways leading to the formation of different types of oligomers
Fluorescent In Situ Staining and Flow Cytometric Procedures as New Pre-Diagnostic Tests for Sialidosis, GM1 Gangliosidosis and Niemann–Pick Type C
No full textBackground: Early diagnosis is essential in the field of lysosomal storage disorders for the proper management of patients and for starting therapies before irreversible damage occurs, particularly in neurodegenerative conditions. Currently, specific biomarkers for the diagnosis of lysosomal storage disorders are lacking in routine laboratory practice, except for enzymatic tests, which are available only in specialized metabolic centers. Recently, we established a method for measuring and verifying changes in GM1 ganglioside levels in peripheral blood lymphocytes in patients with GM1 gangliosidosis. However, fresh blood is not always available, and using frozen/thawed lymphocytes can lead to inaccurate results. Methods: We used frozen/thawed fibroblasts obtained from stored biopsies to explore the feasibility of fluorescent imaging and flow-cytometric methods to track changes in storage materials in fibroblasts from patients with three lysosomal neurodegenerative conditions: GM1 gangliosidosis, Sialidosis, and Niemann–Pick type C. We used specific markers for each pathology. Results and Conclusions: We demonstrated that with our methods, it is possible to clearly distinguish the levels of accumulated metabolites in fibroblasts from affected and unaffected patients for all the three pathologies considered. Our methods proved to be rapid, sensitive, unbiased, and potentially applicable to other LSDs
TDP-43 inclusion bodies formed in bacteria are structurally amorphous, non-amyloid and inherently toxic to neuroblastoma cells.
No full textAccumulation of ubiquitin-positive, tau- and α-synuclein-negative intracellular inclusions of TDP-43 in the central nervous system represents the major hallmark correlated to amyotrophic lateral sclerosis and frontotemporal lobar degeneration with ubiquitin-positive inclusions. Such inclusions have variably been described as amorphous aggregates or more structured deposits having an amyloid structure. Following the observations that bacterial inclusion bodies generally consist of amyloid aggregates, we have overexpressed full-length TDP-43 and C-terminal TDP-43 in E. coli, purified the resulting full-length and C-terminal TDP-43 containing inclusion bodies (FL and Ct TDP-43 IBs) and subjected them to biophysical analyses to assess their structure/morphology. We show that both FL and Ct TDP-43 aggregates contained in the bacterial IBs do not bind amyloid dyes such as thioflavin T and Congo red, possess a disordered secondary structure, as inferred using circular dichroism and infrared spectroscopies, and are susceptible to proteinase K digestion, thus possessing none of the hallmarks for amyloid. Moreover, atomic force microscopy revealed an irregular structure for both types of TDP-43 IBs and confirmed the absence of amyloid-like species after proteinase K treatment. Cell biology experiments showed that FL TDP-43 IBs were able to impair the viability of cultured neuroblastoma cells when added to their extracellular medium and, more markedly, when transfected into their cytosol, where they are at least in part ubiquitinated and phosphorylated. These data reveal an inherently high propensity of TDP-43 to form amorphous aggregates, which possess, however, an inherently high ability to cause cell dysfunction. This indicates that a gain of toxic function caused by TDP-43 deposits is effective in TDP-43 pathologies, in addition to possible loss of function mechanisms originating from the cellular mistrafficking of the protein
Il socialismo morale di Aldo Capitini (1918-1948)
No full textThis monograph is focused on the reconstruction of the socialism of Aldo Capitini (1899-1968). As the author shows, Capitini’s socialism is a very atypical one. It stems from an attempt to overcome that cultural, philosophical and religious crisis which culminates in the First World War and that is due to the end of the faith in progress. Therefore, Capitini’s socialism is peculiarly nourished by a religious perspective which cannot be reduced to Catholicism, nor to any other version of the reformed Christian churches existing in Europe. In a similar way, Capitini’s socialism rejects all those ideologies, such as communism and liberalism, which are based on the assumption that history is led by progress. Capitini’s socialism underlines the importance of individual responsibility seen as a fundamental crossroads able to promote change and revolution in a world which has become indifferent to any metaphysical reference to progress. Lots of manuscripts and unpublished materials have been consulted with a view both to uncovering the sources of Capitini’s socialism and to finding an answer to some theoretical knots, such as that – which Norberto Bobbio himself did not manage to solve in a satisfactory way - of the relationship between this kind of socialism and the institutional framework. According to this reconstruction, Capitini's socialism favours some form of integration between its moral and religious inspiration and the state
Lorenzo Milani in our times
No full textThis article pays tribute to one of Europe's foremost critical pedagogues, the Tuscan Don Lorenzo Milani, on the ninetieth anniversary of his birth. It highlights the key moments in his life as priest and educator as well as his pedagogical approach directed at challenging the class-conditioned status quo in Italian society and at achieving greater social justice. His was a pedagogy which highlighted the collective dimensions of learning and teaching, pupils being students and educators at the same time, an approach to learning akin to what Paulo Freire would call critical literacy and what contemporary writers would call critical media literacy in the sense of reading and writing the word and the world. His pedagogy entailed a process of reading history against the grain as part of an attempt to generate a culture of non-militarization. All these elements make Don Milani and his student-teachers pedagogues for our times.peer-reviewe
Highlights of the First International "Immunotherapy in Pediatric Oncology: Progress and Challenges" Meeting.
No full textThe first annual conference on immunotherapy in pediatric oncology was held in Bethesda, MD, from September 9 to 10, 2008 to discuss the state-of-the-art of immunotherapeutic strategies currently being explored in pediatric oncology. Major topics included targeting cell surface receptors, understanding and improving T-cell-based therapies, augmenting innate immune strategies, and enhancing graft-versus-leukemia for pediatric malignancies. As can be seen in the summaries of the individual presentations, significant progress has been made in developing preclinical models of pediatric tumors and a variety of novel immunobiologic therapies are approaching, or already in, the clinic. Although there is much excitement about the potential utility of these agents, a great deal of challenges lie ahead in improving the efficacy of each of these modalities and getting them to patients in a timely fashion. The resulting discussions will hopefully lead to new collaborations and insight for further translational and clinical studies
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