Diss. (sammanfattning) Stockholm : Karolinska institutet, 2006. / Härtill 4 uppsatser.

Diss. (sammanfattning) Stockholm : Karol. inst., 2006. / Härtill 4 uppsatser.

Diss. (sammanfattning) Stockholm : Karol. inst., 2006. / Härtill 4 uppsatser.

Thesis (Ph. D.)--University of Washington, 2008. / Vita. Includes bibliographical references (leaves 173-208).

Thesis (Ph.D. in Biochemistry) -- University of Colorado Denver, 2008. / Typescript. Includes bibliographical references (leaves 128-144). Free to UCD affiliates. Online version available via ProQuest Digital Dissertations;

MicroRNAs (miRNAs) represent a major system of post-transcriptional regulation, by either preventing translational initiation or by targeting messenger RNA transcripts for storage or degradation. miRNA deregulation has been reported in neurodegenerative disorders, such as Huntington’s disease (HD) and Parkinson’s disease (PD), which may impact gene expression and modify disease progression and/or severity. To assess the relationship of miRNA levels to HD, small RNA sequence analysis was performed for 26 HD and 36 non-disease control samples derived from human prefrontal cortex. 75 miRNAs were differentially expressed in HD brain as compared to controls at genome-wide significance (FDR q<0.05). Among HD brains, nine miRNAs were significantly associated with the extent of neuropathological involvement in the striatum and three of these significantly related to a continuous measure of striatal involvement, after statistical adjustment for the contribution of HD gene length. Five miRNAs were identified as having a significant, inverse relationship to age of motor onset, in particular, miR-10b-5p, the mostly strongly over-expressed miRNA in HD cases. Although prefrontal cortex was the source of tissue profiled in these studies, the relationship of miR-10b-5p levels to striatal involvement in the disease was independent of cortical involvement. In blood plasma from 26 HD, 4 asymptomatic HD gene carriers and 8 controls, miR-10b-5p levels were significantly elevated in HD as compared to non-diseased and preclinical HD subjects, demonstrating that miRNA alterations associated with diseased brain may be detected peripherally. Using small RNA sequence analysis for 29 PD brains, 125 miRNAs were identified as differentially expressed at genome-wide significance (FDR q<0.05) in PD versus controls. A set of 29 miRNAs accurately classified PD from non-diseased brain (93.9% specificity, 96.6% sensitivity, 4.8% absolute error). In contrast to HD, among PD cases, miR-10b-5p was significantly decreased and had a significant, positive association to onset age independent of age at death. These studies provide a detailed miRNA profile for HD and PD brain, identify miRNAs associated with disease pathology and suggest miRNA changes observed in brain can be detected in blood. Together, these findings support the potential of miRNA biomarkers for the diagnosis and assessment of progression for neurodegenerative diseases.

The pathological hallmark of many age-related neurodegenerative diseases is the presence of proteinaceous inclusions in nerve cells and glial cells. Alpha-synuclein is the main component of the inclusions of Parkinson’s disease, dementia with Lewy bodies and multiple system atrophy, as well as of rarer diseases, collectively called synucleinopathies. For a long time, it was widely believed that neurodegenerative diseases were cell-autonomous; however, a more recent hypothesis has suggested that some misfolded proteins resemble prions. Thus, aggregated alpha-synuclein shares features of PrPSc, the scrapie form of the prion protein. The aim of this thesis was to further characterize the prion-like properties of aggregated alpha-synuclein by studying the pathways of seeded aggregation, and to identify the species of alpha-synuclein responsible. I present evidence, using a HEK 293T cell model, that filamentous protein was the most seed-potent form of alpha-synuclein. Recombinant aggregated protein, aggregated alpha-synuclein from mice transgenic for A53T alpha-synuclein, as well as alpha-synuclein aggregates from Parkinson’s disease and multiple system atrophy brains, seeded aggregation. The mechanisms of alpha-synuclein internalization and intracellular trafficking, and how these processes affect seeded aggregation, are not fully understood. I showed that internalization of alpha-synuclein aggregates occurs through clathrin- and dynamin-independent, Cdc42-, actin- and PI3K-dependent endocytosis. Alpha-synuclein aggregates are trafficked to the endolysosomal pathway; a small fraction of lysosomes ruptures, which induces aggregation of expressed cytoplasmic alpha-synuclein, and disruption of autophagy, which in turn enhances seeded aggregation. These findings expand knowledge of the prion-like properties of assembled alpha-synuclein and identify novel mechanisms with therapeutic potential.

abstract: Healthy mitochondria are essential for cell survival. Described herein is the synthesis of a family of novel aminoquinone antioxidants designed to alleviate oxidative stress and prevent the impairment of cellular function. In addition, a library of bleomycin disaccharide analogues has also been synthesized to better probe the tumor targeting properties of bleomycin. The first study involves the synthesis of a benzoquinone natural product and analogues that closely resemble the redox core of the natural product geldanamycin. The synthesized 5-amino-3-tridecyl-1,4-benzoquinone antioxidants were tested for their ability to protect Friedreich's ataxia (FRDA) lymphocytes from induced oxidative stress. Some of the analogues synthesized conferred cytoprotection in a dose-dependent manner in FRDA lymphocytes at micromolar concentrations. The biological assays suggest that the modification of the 2-hydroxyl and N-(3-carboxypropyl) groups in the natural product can improve its antioxidant activity and significantly enhance its ability to protect mitochondrial function under conditions of oxidative stress. The second project focused on the synthesis of a library of bleomycin disaccharide-dye conjugates and monitored their cellular uptake by fluorescence microscopy. The studies reveal that the position of the carbamoyl group plays an important role in modulating the cellular uptake of the disaccharide. It also led to the discovery of novel disaccharides with improved tumor selectivity. / Dissertation/Thesis / Ph.D. Chemistry 2013

Orientador: Satoshi Kitamura / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Ciências Médicas / Made available in DSpace on 2018-08-22T11:47:36Z (GMT). No. of bitstreams: 1 Luchesi_KarenFontes_D.pdf: 2231982 bytes, checksum: 2f5ef1dbfa543808275311de510df643 (MD5) Previous issue date: 2013 / Resumo: A Doença de Parkinson (DP) é uma das doenças neurodegenerativas mundialmente mais prevalentes. Dentre as doenças do neurônio motor, a Esclerose Lateral Amiotrófica (ELA) é a mais frequente. A qualidade de vida e o prolongamento da expectativa de vida dos sujeitos com doenças neurodegenerativas, como ELA e DP, são foco da intervenção fonoaudiológica, visto que uma das maiores causas de morte são as pneumonias aspirativas. Esta pesquisa teve por objetivo analisar e descrever aspectos relacionados à disfagia e à sua progressão em sujeitos diagnosticados com ELA e DP. Ao todo, participaram 49 sujeitos com ELA e 24 sujeitos com DP. Todos foram avaliados e acompanhados no ambulatório de Otorrinolaringologia/Disfagia do Hospital de Clínicas da Universidade Estadual de Campinas. Foram incluídos no estudo, apenas os sujeitos que estavam em acompanhamento periódico no ambulatório de neurologia do referido hospital e em tratamento medicamentoso. Foram excluídos os sujeitos sem queixa de deglutição ou que apresentassem outras doenças que pudessem causar alteração na deglutição. Todos foram submetidos à entrevista estruturada, videoendoscopia da deglutição, avaliação clínica da deglutição e intervenção fonoaudiológica, além de terem a funcionalidade de ingestão oral classificada pela Functional Oral Intake Scale. Foi realizada uma análise descritiva dos dados com apresentação de frequência das variáveis categóricas e medidas de tendência central e dispersão das variáveis numéricas. Na análise exploratória foram utilizados: Regressão de Cox, teste Exato de Fisher, teste de Kruskal-Wallis, Qui-quadrado, teste de Mann-Whitney e análise de sobrevivência de Kaplan-Meier. As análises foram realizadas por meio do software SPSS versão 13.0 para Windows, tendo sido adotado o nível de significância para os testes estatísticos de 0,05. Na ELA, foi identificado como fator associado à disfagia moderada ou grave, a odinofagia (p=0,01). Foram identificados como fatores que influenciaram na progressão da disfagia na ELA a idade de início da doença (p=0,02) e o início bulbar (p=0,04). A idade de início avançada (p=0,03) e o menor tempo de doença até a primeira avaliação (p=0,004) foram identificados como fatores que levaram à necessidade de indicação de uma via alternativa de alimentação em menor tempo na ELA. Não foram identificados fatores que influenciassem a progressão da disfagia na DP. Observou-se melhora e estabilização da função de deglutição na maioria dos sujeitos com DP estudados. Conclui-se que a idade de início e o início bulbar da ELA são fatores associados à piora rápida da disfagia. Não houve fatores associados à progressão da disfagia na PD e a funcionalidade na deglutição destes pacientes foi caracterizada por melhora e manutenção / Abstract: Parkinson's disease (PD) is one of the most prevalent neurodegenerative diseases worldwide. Among the motor neuron diseases, the Amyotrophic Lateral Sclerosis (ALS) is the most common. The quality of life and longer life expectancy for these individuals with neurodegenerative diseases are the purpose of speech-language therapy, as the leading cause of death are aspirative pneumonias. The objective of this study was to analyze and describe aspects related to dysphagia and its progression in patients diagnosed with ALS and PD. Altogether, 49 patients with ALS and 24 patients with PD participated in the study. All patients were evaluated and followed by at the Otolaryngology/Dysphagia services of the Clinical Hospital of the University of Campinas. The study included only patients who have been regularly monitored at the neurology service and undergoing drug treatment. Patients who had other conditions that could cause changes in swallowing or with no complaints concerning swallowing were excluded. All patients underwent a structured interview, Fiberoptic Endoscopic Evaluation of Swallowing, clinical evaluation of swallowing and swallowing management. Furthermore, they had the swallowing functionality classified by the Functional Oral Intake Scale. We performed a descriptive analysis with presenting the frequency of categorical variables, central measures tendency and dispersion of numerical variables. In exploratory data analysis were applied Cox Regression, Kruskal-Wallis, Chi-square, Mann-Whitney and survival analysis of Kaplan-Meier. The analyses were performed using SPSS version 13.0 for Windows and the significance level for statistical tests was 5%. Odynophagia was identified as an associated factor with moderate or severe dysphagia in ALS. The onset age of ALS (p = 0.02) and the bulbar onset ALS (p = 0.04) were identified as factors that influence the progression of dysphagia in ALS. Advanced onset age (p = 0.03) and shorter disease duration (p = 0.004) were identified as factors that lead to sooner need for non-oral feeding. We did not identify any associated factors with the progression of dysphagia in PD. We noticed an improvement and stabilization of the swallowing function in most patients with PD. We conclude that the onset age and bulbar onset of ALS are factors associated with rapid worsened dysphagia / Doutorado / Epidemiologia / Doutora em Saúde Coletiva

Amyotrophic lateral sclerosis (ALS) is an incurable neurodegenerative disease of motor neurons characterized by muscle paralysis and death within 3-5 years of onset. However, due to unknown mechanisms, the extraocular muscles (EOMs) remain remarkably unaffected. The EOMs are highly specialized muscles that differ from other muscles in many respects, including innervation and satellite cells (SCs). Understanding whether these factors play a role in the relative sparing of EOMs in ALS could provide useful clues on how to slow down the progression of ALS in other muscles. The EOMs and limb muscles from terminal ALS patients and age-matched controls as well as the commonly used SOD1G93A ALS mouse model were studied with immunofluorescence. Antibodies against neurofilament and synaptophysin were used to identify nerves and neuromuscular junctions (NMJs); against Pax7, NCAM, MyoD, myogenin, Ki-67, dystrophin and laminin, to identify SCs and their progeny in EOMs and limb muscles. The proportion and fiber size of myofibers containing myosin heavy chain (MyHC) slow tonic and MyHC slow twitch were also determined in human EOMs. The abundance of SCs differed extensively along the length of control human EOMs, being twice as abundant in the anterior portion. Pax7-positive cells were also detected in non-traditional SC positions. EOMs from terminal ALS patients showed similar numbers of resting and activated SCs as the controls. In limb muscles of ALS patients, the number of resting and activated SCs ranged from low (similar to normal aged, sedentary individuals) to high numbers, especially in muscles with long duration of disease and varied between the upper and lower limbs. The EOMs maintained a high degree of innervation compared to hindlimb muscles of symptomatic SOD1G93A mice. MyHC slow tonic fibers were less abundant in ALS patients than in controls. The change seemed more pronounced in bulbar onset patients, and in this group of subjects only, there was a strong association between decline in MyHC slow tonic fibers and age of death. Notably, the decline in MyHC slow tonic fibers was unrelated to disease duration. Our data suggested that SCs play a minor role in the progression of ALS in general and in the sparing of the EOMs in particular. The generally preserved innervation in the EOMs of G93A mice may reflect distinct intrinsic properties relevant for sparing of the oculomotor system.  Even though the EOMs are relatively spared in ALS, MyHC slow tonic myofibers were selectively affected and this may reflect differences in innervation, as these fibers are multiply innervated. / Amyotrofisk lateralskleros (ALS) är en obotlig neurodegenerativ sjukdom som främst påverkar kroppens viljestyrda motoriska nervceller. ALS leder till förlamning, muskelförtvining och slutligen döden genom andningssvikt, vanligen inom tre till fem år efter sjukdomsdebuten. Av okända anledningar så bibehålls ögonmusklernas funktion mycket bättre vid ALS i jämförelse med andra muskler och är hos merparten av patienter i stort sett opåverkade. Ögonmusklerna är mycket specialiserade muskler som skiljer sig från andra muskler i kroppen på flera sätt, bland annat genom deras unika nervförsörjning och genom de satellitceller – muskelspecifika stamceller, som finns i dem. En ökad förståelse för hur dessa faktorer inverkar på ögonmusklernas motståndskraft vid ALS skulle kunna ge värdefulla ledtrådar till hur man skulle kunna sakta ned sjukdomens fortskridande i andra muskler vid ALS. Ögonmuskler och extremitetsmuskler från avlidna ALS-patienter och åldersmatchade friska kontroller, tillsammans med transgena möss med den sjukdomsalstrande mutationen SOD1G93A, studerades genom immunfluorescens och efterföljande mikroskopering. Antikroppar mot molekylerna Pax7, NCAM, MyoD, myogenin, Ki-67, laminin och dystrofin användes för att identifiera satellitceller och deras dotterceller i ögonmuskler och extremitetsmuskler. Antikroppar mot neurofilament och synaptofysin användes för att identifiera nerver och neuromuskulära synapser hos transgena SOD1-möss. Antikroppar mot toniska (tonic) och ryckande (twitch) muskelmyosinkedjor användes för att bestämma proportionen av och storleken på dessa typer av muskelfibrer i ögonmuskler från avlidna ALS-patienter och friska kontroller. Mängden satellitceller varierade mellan de främre och de mer bakre delarna i friska, humana ögonmuskler och var dubbelt så många i den främre delen av muskeln jämfört med den mellersta och bakre delen av muskeln. Celler som uttryckte satellitcellsmarkören Pax7 hittades även i icke-traditionella satellitcellspositioner i ögonmusklerna. Mängden satellitceller i ögonmusklerna från ALS-patienter var samma som hos friska kontroller. I extremitetsmusklerna hos ALS-patienter varierade mängden satellitceller mellan låga nivåer (liknande de hos friska åldrade, inaktiva individer) till höga nivåer, särskilt i muskler där sjukdomen fortskridit under lång tid. Dessutom varierade mängden satellitceller mellan övre och nedre extremiteter. Hos symptomatiska SOD1G93A-möss hade ögonmusklerna en mycket välbevarad innervation jämfört med bakbensmusklerna, där många neuromuskulära synapser saknade kontakt mellan nerven och motorändplattan. Proportionen muskelfibrer med toniska muskelmyosinkedjor var lägre hos ALS-patienter jämfört med friska kontroller. Denna minskning var tydligare hos patienter där sjukdomssymtomen hade debuterat i tugg- och ansiktsmuskulaturen – så kallad bulbär ALS. Dessutom fanns det i den här gruppen, men ingen annan studerad grupp, en stark korrelation mellan nedgången i toniska fibrer och patientens ålder. Värt att notera är att minskningen av toniska muskelfibrer saknade korrelation med hur länge patienten hade varit sjuk i ALS. Den generellt välbevarade innervationen i ögonmusklerna hos SOD1G93A-möss kan spegla distinkta inneboende egenskaper hos ögonmusklerna som är av vikt för bevarandet av ögonrörligheten vid ALS. Gällande satellitceller så antyder våra data att satellitceller och deras regenerativa kapacitet spelar en försumbar roll vid ALS i allmänhet och vid ögonmusklernas bevarande i synnerhet. Slutligen, även om ögonmuskler generellt är välbevarade vid ALS så är toniska muskelfibrer märkbart påverkade och detta kan spegla skillnader mellan olika nervcellsgruppers känslighet vid ALS.