Dissecting Tau Isoform Control and Modeling Tauopathies in Directly-Reprogrammed Neurons

Tauopathies are a family of neurodegenerative disorders whose pathology include intracellular tau aggregates, synaptic dysfunction, and neuronal death. Advanced age is the strongest risk factor for developing a tauopathy, independent of a predisposing mutation, therefore the ability to study tauopathies in adult human neurons is vital to understand the age-associated changes which underly disease onset. Tau, the protein product of the gene Microtubule Associated Protein Tau (MAPT), is expressed highly in neurons. There are six tau isoforms whose splicing control and expression is both developmentally and tightly regulated, with only one isoform expressed in fetal brain and all six expressed in the adult brain. Alternative splicing occurs in both the N-terminal and C-terminal regions, varying between 0-2N domains or 3-4 microtubule binding domains (MBD), respectively. Tau isoforms are generally broken into two subgroups: 3R-tau and 4R-tau which represent the inclusion of either 3 or 4 MBDs, with the alternatively spliced MBD encoded by exon 10. Developmentally, the fetal brain expresses 3R-tau as the predominant isoform while the adult human brain expresses an approximately even ratio of 3R:4R. Importantly, imbalances in the isoform ratio, for instance with increased 4R-tau expression over 3R-tau, are sufficient to lead to pathogenic events leading to neurodegeneration. Currently, the molecular mechanisms controlling the tight regulation of 4R-expression remains largely unknown, and a human neuron-based platform that recapitulates 4R-tau expression of the endogenous MAPT as in the adult brain will be vital for studying tauopathies. Induced pluripotent stem cells (iPSCs) have been an instrumental tool to generate human neurons. However, evidence indicates that the induction of pluripotency in iPSCs reverts the cellular age to an embryonic state, thereby limiting the ability of iPSC-derived neurons to capture cellular events that occur in adult neurons. This is exemplified by recent studies showing that iPSC-derived neurons only produce the fetal isoform, 0N3R, limiting our ability to study the function and pathogenicity of adult tau isoforms, along with identifying the endogenous factors that regulate tau isoforms. Alternatively, direct conversion (reprogramming) of adult human fibroblasts to neurons bypasses the stem cell stage and propagates the age signature stored in original somatic cells to the reprogrammed neurons, offering the experimental benefit of modeling adult-onset neurodegenerative diseases. This transdifferentiation is directed by the ectopic expression of the brain-enriched microRNAs (miRNAs) miR-9/9* and miR-124 (miR-9/9*-124). When applied to adult fibroblasts, miR-9/9*-124 converts them to neurons (miNs) by first causing cell cycle exit and fibroblast identity erasure, followed by the neuronal program activation in sequence1. The resulting miNs maintain the epigenetic age of the starting fibroblasts, leading us to ask if they recapitulate adult tau isoform expression. Here, we reveal that miRNA-mediated direct reprogramming generates human neurons that express both 3R and 4R tau in the same ratio detected in adult human brains. RNA profiling by transcript assays and protein profiling by mass spectrometry demonstrates that adult human brain and miNs from adult fibroblasts have indistinguishable 4R tau profiles, which starkly contrasts with the low 4R tau expression in primary fetal human neurons and iPSC-Ns. The endogenous tau isoform regulation in miNs is sensitive to a point mutation within the splice site proximal to exon 10 in tauopathy patients resulting in reprogrammed neurons that showed increased 4R:3R tau ratio. Significantly, the increased level of 4R tau correlated with the formation of insoluble tau and seed-competent tau, reminiscent of that seen in human 4R tauopathies, and contrasting the lack of seed-competent tau seen in iPSC-Ns harboring the same patient mutation. Therefore, miRNA-mediated neuronal reprogramming provides a robust model for studying both the normal and abnormal biology of tau and exon 10 pathological mutations. We propose to use miNs as a model to dissect the adult protein and RNAs controlling tau isoform expression

Quadri, paesaggi, cornici: lo spazio della descrizione nel Maler Nolten di Eduard Mörike

In the novel of Eduard Mörike Maler Nolten, published in 1832 on a «threshold era» between the 1800 and 1900 modernity innovations, interesting transforming modalities of narrative techniques develop, creating continuous changes from narration to description in a space of meeting, contact and conflict between the two grounds, allowing co-belonging forms to emerge. The novel, in which the painter, with the exception of the initial paintings, will no longer be able to paint, does not present the world as a space of action, but as a space of vision and of observation, that tends to enclose, to frame and to close the image in what we could define as narration without time. In the text we have different forms of framing, in scenes, landscapes and spheres of life to which the figures are assigned (especially female characters), where characters and also objects represented do not hold a mere illustrative function, but they threaten the narrative linearity as they escape from the frame or story. If the aim of the description is to create, design spaces of life, spheres of limited action that would give order through construction and configuration, the artificial order of the textual construction is not able to be embedded into the plot and to maintain its figures within the picture. The frame theme converges with the larger theme concerning the margins of representation, meaning an act of delimitation which is at the same time closing and opening to fruition. The issues discussed concern the nature of the limit and margin around which the aesthetic relation develops, and places in which ambiguity of distinctions between what is inside, outside, marginal and constitutive may arise

Annali storici di Principato Citra, A. 6, n. 2.2 (2008)

A. 6, n. 2.2 (2008): G. Guardia, Editoriale, P. 3 ; A. Trezza, Il Cilento in semiotica del paesaggio: testo della cultura e testo paesaggistico, P. 5 ; M.L. Mautone, Un cofanetto nuziale della bottega degli Embrachi al Museo Diocesano di Vallo della Lucania, P. 35 ; E. Granito, Lotte operaie nel Salernitano dall’Unità all’Età Giolittiana. Menechella la scapricciata e i suoi compagni, P. 48 ; A. Gargano, Affreschi oligarchici: lettere anonime, ricorsi e inchieste prefettizie nella vita socio-amministrativa di Pagani nel tardo Ottocento, P. 69 ; E. Bianco, L’incastellamento medievale nel Cilento interno: il borgo murato di Stio (XI-XVI sec.). Prime indagini, P. 96 ; E. Frescani, L’arte di imparare. Note sull’apprendistato nella valle dell’Irno nel XVII secolo, P. 109 ; E. Catone, I marchesi Forcella a Buccino. Brevi note genealogiche, P. 114 ; G. Pepe, Francesco Durelli: uno storico ignorato, P. 124 ; A. La Greca, “In diem Christi conscientiam onerantes”. L’atto di rifondazione della confraternita del SS. Rosario di Montecorice e del suo trasferimento dalla cappella di S. Sofia alla nuova chiesa parrocchiale di S. Biagio (6 febbraio 1589), P. 139 ; A. Capano, Note di toponomastica in margine al Catasto provvisorio di San Giovanni a Piro (1815) e di Bosco sua frazione (20 sett. 1828), P. 146 ; Nota di Redazione, Pioppi: « culla » della Dieta Mediterranea. Celebrati i 25 anni di “Cronache Cilentane” e la XVIII Edizione degli “Incontri Mediterranei”, P. 180 ; M. Serra, Un’avvincente iniziativa editoriale del Centro di Promozione Culturale per il Cilento, P. 183 ; G. De Vita, “Oltre la torre d’avorio”. Un libro degli allievi per i sessant’anni del prof. Luigi Rossi, P. 188

Annali storici di Principato Citra, A. 7, n. 1.1 (2009)

A. 7, n. 1.1 (2009): G. Guardia, Editoriale, P. 3 ; R. Salati, Le ambre "tipo Roscigno”, P. 5 ; E. Bianco, La viabilità medievale nel Parco Nazionale del Cilento e Vallo di Diano. Il territorio del Comune di Gioi, P. 33 ; D. Petrone, Le case-torri nel territorio ebolitano, P. 51 ; A. Capano, Pollica e i suoi casali nel Catasto provvisorio del 1815. Il Sessantotto a Salerno. In margine ad un Convegno e ad un libro, P. 69 ; Francesco Sofia, Il '68: alcune riflessioni, P. 95 ; G. Acocella, Un '68 "cattolico"? P. 104 ; P. Cantillo, La profezia di una società estetica, P. 108 ; G. Foscari, Il '68, P. 112 ; M. La Via, Dal mito degli anni '60 alla utopie del '68, P. 113 ; P. Lucia, Miti, utopie, speranze di una generazione, P. 117 ; L. Marinucci, Donne, istituzioni, movimenti civili: una questione ancora attuale. La Mostra "Le frodi alimentari nella provincia di Salerno fra '800 e '900" tenutasi a Salerno il 16 ottobre 2008, a cura di Caterina Aliberti e Francesco Innnella, P. 121 ; C. Aliberti - F. Innella, La Mostra "Le frodi alimentari nella Provincia di Salerno tra Ottocento e Novecento", P. 126 ; I. Ascione, Le frodi alimentari nella provincia di Salerno fra Ottocento e Novecento, P. 128 ; A. Vacca, Inganni cibici, P. 131 ; V. Ferrara, Le attività operative del Comando Carabinieri Politiche Agricole e Alimentari e del Nucleo Antifrodi Carabinieri di Salerno. Il XIV Festival "Linea d'ombra" - Festival culture giovani, P. 134 ; P. D'Antonio, Caos: tra Filosofia, Scienza e Arte, P. 150 ; S. Metetich, Al caos, al caos! Così è (se vi piace), P. 151 ; P. Simone Di Chiara, Il caos, P. 153 ; F.M. Iandiorio, M. Autuori, P.S. Di Chiara, Il caos della natura fra letteratura e percezione, P. 154 ; S. Maritato, D. Di Stefano, A. Di Lauro, M. Massa, Caos e/è cinema, P. 156 ; F. Bonifacio, M. Talento, A. Catoio, Obiettivo caotico, P. 158 ; M. Radano, Per una "memoria" del territorio. Le celebrazioni per il Millenario di Guarrazzano di Stella Cilento (1009-2009), P. 160