1,720,959 research outputs found
PROTEOMIC INVESTIGATION ON NASU-HAKOLA DISEASE: SHEDDING LIGHT ON FRONTOTEMPORAL TREM2-BASED DEMENTIA.
Get PDFLa malattia di Nasu-Hakola (NHD), nota anche come osteodisplasia lipomembranosa policistica con leucoencefalopatia sclerosante (PLOSL), è una patologia sistemica ereditaria recessiva caratterizzata da demenza presenile frontotemporale e lesioni ossee. Le basi genetiche che determinano la patologia sono correlate ad un difetto strutturale di due geni, TREM2 e DAP12, che codificano per due subunità del recettore transmembrana di un complesso di segnalazione espresso dalle cellule della microglia e dagli osteoclasti. Ad oggi, studi molecolari o proteomici di questa malattia sono assenti o scarsi, infatti in letteratura sono riportati solo studi cognitivo-comportamentali e genetici di singoli pazienti. Con l’obiettivo di ottenere maggiori informazioni circa l'insorgenza e/o la progressione dell’NHD, lo scopo di questo progetto di dottorato è stato quello di caratterizzare il proteoma linfoblastoide di un'intera famiglia in cui due membri hanno manifestato un fenotipo NHD.
Il progetto è stato focalizzato sull'analisi proteomica della linea cellulare linfoblastoide (LCL) ottenuta da 7 soggetti: due omozigoti (Ho), quattro eterozigoti (He) ed un wildtype (Wt). L'approccio proteomico utilizzato è gel-free e basato sulla tecnologia MudPIT (Multidimensional Protein Identification Technology) che si avvale della combinazione di micro-cromatografia liquida bidimensionale e spettrometria di massa tandem ad alta risoluzione. L'identificazione delle sequenze peptidiche e delle relative proteine è stata ottenuta tramite un software (Bioworks) basato sull'algoritmo SEQUEST per l’interpretazione degli spettri di massa acquisiti. Le liste proteiche sono state sottoposte all'analisi bioinformatica mediante software sviluppati in laboratorio (MAProMa, Multidimensional Algorithm Protein Map) e/o disponibili in rete, allo scopo di evidenziare gli andamenti di espressione proteica e le vie metaboliche coinvolte nell'insorgenza e/o progressione dell’NHD. Lo studio ha permesso di identificare circa 3000 proteine distinte all'interno dei tre gruppi analizzati e circa 400 proteine sono state identificate come peculiari di ciascuna categoria (Ho, He, Wt). In particolare, i dati hanno evidenziato la presenza di proteine differenzialmente espresse associate a processi correlabili alla neurodegenerazione. Inoltre, le reti proteiche hanno messo in rilievo alcune via molecolari che potrebbero essere coinvolte nell'insorgenza o nella progressione di questo raro disordine frontotemporale. Pertanto, la piattaforma MudPIT, completamente automatizzata, ha dimostrato la sua efficacia nello studio dei profili di espressione proteica di pazienti affetti da NHD e si può candidare come valida piattaforma per lo studio di altre demenze frontotemporali legate a TREM2. Infatti, questo approccio ha consentito di generare, per la prima volta, il profilo proteico più completo delle cellule linfoblastoidi appartenenti a soggetti Nasu-Hakola e di caratterizzare le vie metaboliche coinvolte nelle alterazioni funzionali di questa patologia.Nasu-Hakola Disease (NHD), also known as Polycystic Lipomembranous Osteodysplasia with Sclerosing Leukoencephalopathy (PLOSL), is a recessively inherited systemic leucodystrophy disorder characterized by a combination of frontotemporal presenile dementia and lytic bone lesions. It is known that NHD is genetically related to a structural defect of TREM2 and DAP12 genes that encode for different subunits of the membrane receptor signalling complex expressed by microglia and osteoclast cells. To date, molecular or proteomic studies about this disorder are absent or scarce, and only case reports based on neuropsychological and genetic tests have been reported. In light of this, to obtain in depth knowledges about the onset and/or progression of the NHD, the aim of this PhD project was to characterize the Lymphoblastoid proteome of an entire family in which two members manifested a NHD phenotype, through an innovative proteomic approach.
The project was focused on the proteomic analysis of Lymphoblastoid cell lines (LCLs) obtained from 7 kin subjects: two homozygote (Ho), four heterozygote (He) and one wild type (Wt). Gel-free proteomic approach, based on MudPIT (Multidimensional Protein Identification Technology), was applied for the analysis of the whole protein extract. The identification of peptide sequences and their assigned proteins was obtained through an automated protein discovery software (Bioworks) based on SEQUEST algorithm for data handling of mass spectra. Protein lists were submitted to bioinformatics analysis by means of a home-made software (MAProMa, Multidimensional Algorithm Protein Map) and available on-line tools, in order to highlight the protein expression trends and the most involved pathways in the NHD onset and/or progression.
The application of a gel-free proteomic approach on NHD subjects allowed to identify about 3000 distinct proteins within the three analysed groups and about 400 proteins were identified as peculiar of each category (Ho, He, Wt). Of note, data showed the presence of differentially expressed proteins associated to neurodegenerative processes. Moreover, the protein networks highlighted some molecular pathways that could be involved in the onset or progression of this rare frontotemporal disorder. Therefore, the fully automated MudPIT platform has demonstrated its effectiveness in the study of the protein expression profiles of NHD patients and could be a valid platform for the investigation of other TREM2-based frontotemporal dementias. This approach allowed to generate, for the first time, the whole protein profile of Lymphoblastoid cells from Nasu-Hakola subjects and to characterize the metabolic pathways involved in functional alterations of this pathology
A novel approach to investigate a rare Frontotemporal Disorder: proteomic studies about Nasu-Hakola Disease
No full textFrontotemporal dementias (FTD) include a large spectrum of pathologies based on different triggers. Among the FTD related to genetic causes and behavioral disorders (bvFTD), a rare recessively inherited systemic disorder named Nasu-Hakola Disease (NHD) is worthy of note. It is phenotypically characterized by simultaneous impairment of nervous and skeletal systems and genetically related to a structural defect of the two genes DAP12 and TREM2. These genes encode for different subunits of the membrane receptor signaling complex and are expressed by cells of both systems involved. To date, the diagnosis of NHD is carried out by genetic or psychological tests only; no biochemical/molecular studies being available to obtain an early diagnosis or a follow-up of the NHD progression.
In the present study we used MudPIT (Multidimensional Protein Identification Technology) approach for the characterization of Lymphoblastoid cells from NHD patients and healthy controls.
Aim of this research was to obtain a more complete picture about the mechanisms involved into NHD onset and to evaluate the presence of possible blood biomarkers of this pathology.
Specifically, two NHD patients (DS), four healthy carriers (HC) and one healthy subject (HS) belonging to the same Italian family have been submitted to blood withdrawal to isolate and
immortalize the B-Lymphocytes. MudPIT allowed the identification of more than 3000 distinct proteins, a number 100-fold higher than that of proteins identified by gel electrophoresis (2-DE)
[Giuliano et al. PLoS One 2014; 9]. The comparison of protein profiles from DS, HC and HS groups by means of MAProMa software showed that 10% of identified proteins was peculiar of each
group. In addition, network analysis of proteomics data evidenced the disease-related pathways, such as energy metabolism, including glucose pathway.
This work represents a proof of principle for characterizing dysregulated proteins and related metabolic pathways involved in functional alterations of this pathology
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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