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Factors sèrics en l’Esclerosi Lateral Amiotròfica. Modulació del receptor de glutamat de tipus NMDA GluN1/GluN2ATeixidó Viyuela, Laura 18 February 2011 (has links)
L’Esclerosi Lateral Amiotròfica (ELA o ALS) és una malaltia neuromuscular caracteritzada per la degeneració selectiva de les motoneurones (MN) superiors e inferiors del còrtex motor, el tronc de l’encèfal i la medul•la espinal, que resulta en una debilitat, espasticitat i atròfia progressives de la musculatura. Menys del 10% dels casos corresponen a la forma familiar de la malaltia, i un 20% d’aquests estan relacionats a mutacions en el gen de l’enzim superòxid dismutasa 1 (mSOD1). La resta de casos corresponen a la forma esporàdica. Les causes implicades en la degeneració selectiva de les MN en la ELA són encara desconegudes. La seva patogènesi s’ha atribuït a diversos mecanismes com serien l’estrès oxidatiu, l’agregació proteica anormal, la disfunció mitocondrial, el transport axonal aberrant, la neuroinflamació, l’autoimmunitat o l’excitotoxicitat per glutamat. En el present estudi hem treballat amb dues d’aquestes hipòtesis en avaluar l’efecte dels sèrums de pacients amb ELA i altres malalties de la MN sobre l’activitat del receptor ionotròpic de glutamat de tipus N-metil-D-Aspartat (NMDAR), expressat en el model d’oòcit de Xenopus laevis. Mitjançant assaigs de ELISA hem analitzat la presència d’autoanticossos associats a ELA en el sèrum de pacients. L’acció dels sèrums control i patològics en els oòcits de Xenopus produïa la generació de corrents oscil•latoris de clorur (Cl-). Aquests corrents havien estat prèviament descrits en aquestes cèl•lules i són deguts a l’activació dels canals de Cl- dependents de calci (Ca2+), endògens en els oòcits de Xenopus, a causa de la mobilització de Ca2+ intracel•lular. L’alliberació de Ca2+ dels compartiments intracel•lulars es activada per l’acció d’un factor sèric, anomenat àcid lisofosfatídic o lisofosfatidat (LPA), sobre el seu receptor, present en la membrana dels oòcits, i a través d’una via de senyalització de segons missatgers. Així doncs, en aquest model, la generació de corrents oscil•latoris de Cl- és una mesura indirecta de la mobilització intracel•lular de Ca2+. En presència del NMDAR, les respostes generades pel sèrum ELA eren significativament superiors a les activades pel sèrum d’individus sans i d’altres malalties de la MN. La resposta generada pel sèrum ELA presentava una dependència respecte de la presència de les dues subunitats del NMDAR i era sensible al bloqueig del receptor amb MK-801, un antagonista no competitiu. Vàrem reproduir els experiments amb sèrums del model de rata transgènica mSOD1 G93A, considerat un model de la forma familiar de la malaltia. Les mostres de sèrum mSOD1 G93A generaven, en presència del NMDAR, respostes significativament superiors a les activades pel sèrum de rata WT. En analitzar l’acció de la fracció de IgG purificada dels sèrums control i patològics en el model d’oòcit de Xenopus, es generaven corrents transitoris d’entrada de tipus no oscil•latori, els quals diferien dels generats en el cas del sèrum complet. La resposta activada per IgG de pacients amb ELA en presència del NMDAR era també significativament superior a la generada per les IgG d’individus sans. En la segona part d’aquest estudi s’ha comprovat la presència d’anticossos contra la proteïna Semaforina 3A (Sema3A) en alguns sèrums de ELA i Lower Motor Neuron Disease (LMND), una altra forma comuna de malaltia de la MN. La Sema3A és una molècula quimiotàctica de guia axonal recentment relacionada amb la patologia de la ELA en detectar-se una sobreexpressió d’aquesta proteïna en cèl•lules de Schwann terminals del model de ratolí mSOD1 G93A. Tot i descartar-se que els anticossos contra Sema3A siguin un marcador específic de la ELA, al no detectar-se en tots el sèrums de pacients, i alhora, al estar presents també en algunes mostres LMND, aquests autoanticossos podrien tenir un efecte defensiu contra les senyals nocives exercides per Sema3A sobre els axons de les MN. / Amyotrophic lateral sclerosis (ALS) is a devastating neuromuscular disease, characterized by the selective degeneration of the superior motor neurons in the motor cortex and of the inferior motor neurons in the brain-stem and spinal cord. The familial form of the illness is associated with the mutation of the superoxide dismutase enzyme (SOD-1). This and other mutations accounts for fewer than 10% of cases; the rest, more than 90%, correspond to the sporadic form. In this study we tested the effect of sera from sporadic ALS patients and from mutated human SOD-1 (mSOD1 G93A) transgenic rats on N-methyl-D-aspartate receptors (NMDAR). We hypothesize that an endogenous excitotoxic factor is implicated in neuronal death in ALS, mediated by the activation of NMDAR noncanonical signalling pathways. Sera from ALS patients or healthy subjects were pretreated to inactivate complement pathways and dialysed to remove glutamate. Sera from mSOD1 G93A rats were obtained at different stages of the neurodegenerative progression. Sera from transgenic rats were also pretreated to eliminate complement system and glutamate. Immunoglobulins G (IgGs) from ALS patients and healthy subjects were obtained by affinity chromatography and dialyzed against phosphate-buffered saline. Human NMDAR were expressed in Xenopus laevis oocytes, and glutamate-induced currents were recorded using the two electrode voltage clamp technique. We observed that sera from sporadic ALS patients induced transient oscillatory currents in Xenopus oocytes expressing NMDAR with a total electric charge significantly higher than the electric charge carried by currents induced by sera from healthy subjects. The currents were inhibited by MK-801, a noncompetitive blocker of NMDAR. Results of sera from mSOD1 G93A transgenic rats were similar to those of sera from ALS patients; samples from patients with another type of neuromuscular disease did not exert this effect. IgG from ALS patients have a significant effect on NMDAR-injected oocytes and that response was doubled respect to the observed in the case of IgG from healthy subjects. Our data agree with the view that ALS patients sera contain some soluble factors that activates NMDAR, not opening directly the ionic conductance, but activating a non-canonical pathway.
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A study of human-robot interaction with an assistive robot to help people with severe motor impairmentsChoi, Young Sang. January 2009 (has links)
Thesis (Ph.D)--Industrial and Systems Engineering, Georgia Institute of Technology, 2010. / Committee Chair: Kemp, Charles; Committee Member: Glass, Jonathan; Committee Member: Griffin, Paul; Committee Member: Howard, Ayanna; Committee Member: Thomaz, Andrea. Part of the SMARTech Electronic Thesis and Dissertation Collection.
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Pharmakologische Inhibition von Rho-Kinase im Mausmodell der Amyotrophen Lateralsklerose / Pharmacological inhibition of Rho-kinase in the mouse model of amyotrophic lateral sclerosisGünther, René 23 June 2015 (has links)
No description available.
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Detection, transfer and role of an environmentally spread neurotoxin (BMAA) with focus on cyanobacteria and the Baltic Sea regionBerntzon, Lotta January 2015 (has links)
β-N-methylamino-L-alanine (BMAA) is one of the more recently discovered bioactive compounds produced by cyanobacteria. BMAA is a non-protein amino acid reported present in human brain tissues of patients deceased from a neurodegenerative disease, such as Alzheimer´s disease or amyotrophic lateral sclerosis (ALS). This observation in combination with its neurotoxic effects in eukaryotes (in vivo and in vitro) and its potential to incorporate into (human) proteins, causing protein aggregation, suggests BMAA as a possible causative environmental agent for neurodegenerative diseases. Due to the ubiquitous nature of cyanobacteria with a wide occurrence in both aquatic and terrestrial environments, BMAA could be globally spread. Hence, investigations of a possible coupling between BMAA and neurodegeneration are urgently needed as well as to identify sources of BMAA in Nature. The aim of this thesis was to examine the potential occurrence of BMAA in bloom forming cyanobacteria of the Baltic Sea and its possible transfer to other organisms of this ecosystem. Of importance was also to reveal any likely routes for human BMAA exposure in the Baltic Sea region and to further investigate BMAA as a triggering agent for neurodegenerative diseases. Acknowledged difficulties of analysing BMAA in biological samples also inferred method development as part of the experimental studies. Investigating the role of BMAA in its producers was another purpose of the thesis, which may be crucial for future management of BMAA-producing cyanobacteria. By screening natural populations of the major filamentous bloom forming cyanobacteria of the Baltic Sea, we discovered the presence of BMAA throughout the entire summer season of two consecutive years, using a highly specific analytical method (liquid chromatography-tandem mass spectrometry; LC-MS/MS). BMAA was found to bioaccumulate in zooplankton and fish, as well as in mussels and oysters from the Swedish west coast. To improve the understanding of BMAA analyses in natural samples, the formation of carbamate adducts in the presence of bicarbonate was examined. Using two derivatization techniques in combination with LC-MS/MS, we could show that BMAA detection was not hindered by carbamate formation. Exogenously added BMAA inhibited nitrogen fixation in the model cyanobacterium Nostoc sp. PCC 7120, which was also hampered in growth and displayed signs of nitrogen starvation. Finally, BMAA was detected in cerebrospinal fluid in three of 25 Swedish test individuals, and represents the first confirmation of BMAA in the human central nervous system using LC-MS/MS as the primary analytical method. However, the association of BMAA to neurodegenerative diseases could not be verified as BMAA was present in both control individuals (two) and in one ALS-patient. Nevertheless, the finding of a known neurotoxic compound in the human central nervous system is alarming and potential consequences should be investigated. The discovery of the neurotoxic compound BMAA in Baltic Sea organisms, and in the central nervous system of humans potentially consuming fish from this ecosystem is concerning and warrants continued investigations of BMAA occurrence and human exposure. Further knowledge on the function and regulation of BMAA may help in developing strategies aiming to minimise human exposure. / <p>At the time of the doctoral defense, the following paper was unpublished and had a status as follows: Paper 3: Manuscript.</p>
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Διερεύνηση της γενετικής προδιάθεσης της πλάγιας αμυοτροφικής σκλήρυνσης στον ελληνικό πληθυσμόΜερκούρη Παπαδήμα, Ελένη 13 January 2015 (has links)
Η Πλάγια Αμυοτροφική Σκλήρυνση είναι μια ετερογενής νόσος, που οφείλεται στην εκφύλιση των ανώτερων και κατώτερων κινητικών νευρώνων. Αρχικά η νόσος εκδηλώνεται είτε με μυϊκή αδυναμία και σπαστικότητα των άνω ή κάτω άκρων, είτε με δυσχέρεια στην ομιλία. Η εξέλιξη της νόσου είναι μοιραία και ο αναμενόμενος χρόνος επιβίωσης είναι 3 – 5 χρόνια. Με την εμφάνιση της νόσου έχουν συσχετιστεί πολλοί γενετικοί και περιβαλλοντικοί παράγοντες. Ταυτοχρόνως, έχουν προταθεί και πολλοί μηχανισμοί παθογένειας. Παρόλα αυτά, η ALS παραμένει ανίατη και οι υπάρχουσες θεραπείες αποσκοπούν στην βελτίωση της κλινικής εικόνας ή / και στην παράταση της επιβίωσης. Ιδιαίτερα στον ελληνικό πληθυσμό, η γενετική αιτία της νόσου δεν έχει διερευνηθεί επαρκώς. Μεταλλάξεις στα γονίδια SOD1, TARDBP και FUS στις οποίες οφείλεται το 30% των οικογενών περιπτώσεων ALS σύμφωνα με τη βιβλιογραφία, δεν απαντώνται στους ασθενείς με ελληνική καταγωγή.
Για αυτό το λόγο, με τη βοήθεια της αλληλούχησης ολόκληρου του γονιδιώματος και χρησιμοποιώντας διάφορες προσεγγίσεις πάνω στα δεδομένα που εξήχθησαν, εστιάσαμε την έρευνά μας σε συγκεκριμένες παραλλαγές. Στόχος μας ήταν ο έλεγχος για πιθανές συσχετίσεις μεταξύ των παραλλαγών αυτών και της εμφάνισης της νόσου. Η επιλογή των παραλλαγών στηρίχθηκε στους κοινούς μεταξύ των ασθενών πολυμορφισμούς που δεν υπήρχαν στο δείγμα αναφοράς. Από αυτή την προσέγγιση, επιλέχθηκαν οι κοινοί πολυμορφισμοί rs6850200 (TBC1D1), rs1861869 (FTO), rs2892469 (FTO), rs4773203 και rs10581954 (A2LD1), rs34030508 (FAM181B) και rs6676539 (KAZN). Η δεύτερη προσέγγιση, περιλάμβανε τις νέες παραλλαγές που εντοπίστηκαν στο γονιδίωμα τουλάχιστον ενός εκ των ασθενών. Μεταξύ αυτών, επιλέχθηκαν 2 παραλλαγές, στην 5’ αμετάφραστη περιοχή των γονιδίων FGF13 και SLC36A1. Σε δεύτερο χρόνο, αντιπαρατέθηκαν οι παραλλαγές των γονιδιωμάτων, με τη βάση δεδομένων Human Gene Mutation Database (HGMD) και συγκεκριμένα, με τις μεταλλάξεις που έχουν συσχετιστεί με την ALS. Ωστόσο, δεν κρίθηκε σκόπιμη η περαιτέρω διερεύνηση των αποτελεσμάτων αυτών. Το δείγμα των ασθενών επεκτάθηκε για τις επιλεγμένες παραλλαγές και τα αποτελέσματα της γονοτύπησης των ασθενών συγκρίθηκαν με τα αποτελέσματα της γονοτύπησης που πραγματοποιήθηκε σε δείγμα αναφοράς. Οι παραλλαγές που έδωσαν στατιστικά σημαντικό αποτέλεσμα, αναλύθηκαν και σε πληθυσμό Σαρδηνίων ασθενών ALS έναντι υγιών ατόμων. Εξετάσθηκε επίσης και η περίπτωση μιας οικογένειας στην οποία υπήρχαν τέσσερα άτομα τα οποία εμφάνιζαν ιδιαίτερο φαινότυπο και είχαν διαγνωστεί με πιθανή ALS. Συλλέχθηκε το πλήρες ιατρικό ιστορικό των ατόμων της οικογένειας που νοσούσαν, ενώ με τη χρήση της μεθόδου νέας γενιάς αλληλούχησης εντοπίστηκε πιθανή μετάλλαξη.
Μεταξύ των συνολικά οχτώ παραλλαγών που μελετήθηκαν (από την πρώτη και δεύτερη προσέγγιση), από την ανάλυση των δύο προέκυψε στατιστικά σημαντική διαφορά μεταξύ υγιών και ασθενών σε επίπεδο γονοτύπων, αλλά όχι σε επίπεδο αλληλομόρφων. Οι συσχετίσεις με την ALS αφορούν τους πολυμορφισμούς, rs6850200 (TBC1D1), rs1861869 και rs2892469 (FTO), στον ελληνικό πληθυσμό. Επιπλέον, οι rs1861869 και rs2892469 συνδέθηκαν με απλότυπο. Οι διαφορές αυτές δεν υπήρχαν στο δείγμα των Σαρδηνίων. Αναφορικά με την οικογένεια, επιβεβαιώθηκε η ύπαρξη μετάλλαξης μεγέθους 25 βάσεων στο γονίδιο SPG7 σε ομόζυγη κατάσταση, στα μέλη της οικογένειας που φέρουν τον φαινότυπο της ALS / HSP (Οικογενούς Σπαστικής Παραπληγίας) και σε ετερόζυγη κατάσταση στα υγιή άτομα της οικογένειας που ελέγχθηκαν. / Amyotrophic Lateral Sclerosis is a heterogeneous disorder, caused by upper and lower motor neuron degeneration. At the first stages of the disease, muscle weakness as well as spasticity of upper or lower limbs or alternatively, impaired speech become obvious. The patients deteriorate rapidly and finally die 3 – 5 years after the initiation of the symptoms. Many genetic and environmental factors have been correlated with ALS. At the same time, a wide range of pathogenesis’ mechanisms have been proposed. Nevertheless, ALS remains a fatal disease and the existing therapies, aim to symptom relief and/ or a slight prolongation of life time expectancy. In particular, the genetic causes of ALS in Greek population, have not been thoroughly investigated. Mutations in SOD1, TARDBP and FUS exons to which 30% of FALS cases are attributed according to the bibliography, are under-represented in patients with a Hellenic ancestry.
Herein, we obtained whole genome sequencing data from 10 Greek ALS patients. To interpret our data we used several approaches, which then helped us focus on certain variations. The aim of the project was to investigate those variations and their possible association with the disease. The variations of interest were chosen according to the following criteria; polymorphisms (i) being common to all patients, (ii) not present in healthy individuals and (iii) located near genes. From this approach, we chose the common polymorphisms rs6850200 (TBC1D1), rs2892469 (FTO), rs1861869 (FTO), rs4773203 and rs10581954 (A2LD1), rs34030508 (FAM181B) and rs6676539 (KAZN). The second approach, includes the annotation of all the novel variants found in at least one patient. Among these variants, two were chosen, both located in the 5’ untranslated regions of the genes FGF13 and SLC36A1. Subsequently, the patients’ genomes variants were juxtaposed with the Human Gene Mutation Database (HGMD) and only those associated with ALS were selected. In this case, however, no further investigation has been performed. Our patients’ population was expanded for the overall chosen variations and their genotypes were compared to the genotypes of healthy individuals. Whenever the outcome had a statistical significance, a replication study was attempted in Sardinian ALS patients compared to healthy individuals. In parallel, we came across a case of a family with interesting phenotype features; four individuals in this family were diagnosed with possible ALS / HSP (Hereditary spastic paraparesis) and their full medical history was acquired. Through a next generation sequencing method a new possible mutation was identified.
Overall, eight variations were studied (from the first and second approach). The polymorphisms rs6850200 (TBC1D1), rs1861869 and rs2892469 (FTO) showed a statistically significant association with ALS at a genotype level in the Greek population. At the same time, rs1861869 and rs2892469 were correlated with the existence of a haplotype. On the contrary, rs1861869 and rs2892469 showed no statistical significant differences, when Sardinian ALS patients were compared to healthy Sardinian individuals. As far as the family mentioned above is concerned, the existence of a homozygous 25bp deletion in the SPG7 gene was confirmed. All the members of the family, who manifested symptoms, bear the deletion.
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Att leva med amyotrofisk lateralskleros (ALS) : Ur ett patientperspektiv / Living with amyotrophic lateral sclerosis (ALS) : From a patient’s perspectivePetersson, Emelie, Pölönen, Katrin January 2011 (has links)
Bakgrund: ALS är en förkortning av amyotrofisk lateralskleros och är en obotlig neurologisk sjukdom. Sjukdomen orsakas av att bindväv ersätter den laterala delen av ryggmärgen vilket leder till impulsbrist och förlamning genom muskelförtvining. Syfte: Syftet med studien var att belysa hur personer med ALS upplever sitt dagliga liv. Metod: En studie av självbiografier gjordes och gav en helhetsbild av individens upplevelse av sjukdomen. Resultat: Personer med ALS påverkades av sin sjukdom både psykiskt och fysiskt. Detta kunde komma både av sjukdomen men också av omgivningen. De upplevde skam och isolering och försökte dölja sin sjukdom. De värdesatte sin självständighet och de hjälpande händerna från personal och assistenter. Diskussion: Ett av huvudfynden i resultatet var att patienter som har ALS kände sig fångade i sina egna kroppar på grund av att de successivt tappade kontrollen över sina förmågor. Ett annat fynd var hur viktigt det var med rätt information, och att ett fel i kommunikationen orsakade missnöje och en känsla av att bli kränkt. Slutligen framkom hur förändringar i omgivningen kunde göra personen mer självständig. / Background: ALS stands for amyotrophic lateral sclerosis and is an incurable neurologic disease. The disease is caused by the degeneration of motor neurons that is being replaced by connective tissue, this leads to paralysis through muscle atrophy. Aim: The aim of this study was to evaluate how people with ALS experience their daily life. Method: This study was based on self biographies to get a general impression of their experience of the disease. Result: Patients with ALS were affected by their surroundings, both mentally and physically. They experienced shame and isolation and they tried to hide their disease. They valued their independence and the helping hands from the family and personal assistants. Discussion: One of the main findings in the study was that patients found themselves imprisoned in their own bodies because they gradually lost their physical abilities. Another finding was how important it was been given the right information and how miscommunication could cause a feeling of being displeased and psychologically abused. A final finding
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Génétique des formes sporadiques de sclérose latérale amyotrophique / Genetics of sporadic amyotrophic lateral scelrosisPraline, Julien 16 December 2009 (has links)
La sclérose latérale amyotrophique (SLA) est une maladie neurodégénérative d’évolution toujours fatale. Dans les formes sporadiques (SLAS), l’étiologie demeure inconnue et l’hypothèse d’une participation génétique dans le cadre d’un modèle de maladie complexe est envisagée. Notre travail porte sur deux gènes de susceptibilité dans la SLAS : le gène de l’Apolipoprotéine E (APOE) et le gène impliqué dans l’hémochromatose familiale de type 1 (HFE). Notre première étude confirme sur une population de 1482 patients atteints de SLA sporadique le lien entre allèle ε4 et la forme bulbaire de la maladie mais uniquement chez les hommes. Nous proposons une explication physiopathologique faisant intervenir le récepteur aux androgènes, particulièrement exprimé au niveau des motoneurones bulbaires. Notre deuxième étude sur 244 patients et 302 contrôles ne retrouve pas l’association entre le polymorphisme H63D et le risque de SLA sporadique notée dans d’autres populations. En revanche, l’allèle Y du polymorphisme C282Y semble exercer un effet protecteur vis-à-vis de la SLA. Ces données sont discutées dans le contexte de l’hypothèse physiopathologique du stress oxydant. / Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease. The cause of sporadic cases (SALS) remains unknown but a genetic participation in a model of complex disease is suspected. Our work concerns two susceptibility genes for SALS: Apolipoprotein E gene (APOE) and the gene involved in familial hemochromatosis (HFE). Our first study including 1482 patients with SALS confirms a link between ε4 allele and bulbar-onset of the disease, only in men. We suggest a pathophysiological explanation with a role for the androgen receptor which is particularly abundant in motor neurons of the brainstem. Our second study about 244 patients and 302 controls did not find any association between the H63D polymorphism and SLAS, which has previously been showed. However, the Y allele of the C282Y polymorphism seems to exert a protective effect against SALS. We discuss these data within the pathophysiological hypothesis of oxidative stress in ALS.
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Vieillissement et maladies neurodégénératives : nouvelles contraintes apportées par la métallomique / Aging and Neurodegenerative Diseases : New Constraints from the MetallomicSauzéat, Lucie 18 April 2018 (has links)
Caractérisé par le déclin progressif et irréversible des fonctions biologiques vitales, le vieillissement est un processus biologique complexe qui s’accompagne souvent par l’apparition de maladies neurodégénératives. D’ici 2050, plus de 1.5 milliards de personnes dans le monde seront définies comme vieillissantes. L'amélioration de la qualité de vie des personnes âgées constitue donc un enjeu majeur pour notre société. Encore mal connue, la dégradation progressive du métallome est associée au vieillissement et à l’apparition de maladies neurodégénératives et en est probablement l’une des causes. L’objectif de cette étude est de mieux caractériser l'évolution du métallome chez deux modèles animaux au cours du temps i.e. la souris et le vers ainsi que chez l’humain atteint de sclérose latérale amyotrophique (SLA). Pour ce faire, nous avons analysé une vingtaine d'éléments traces et majeurs ainsi que les compositions isotopiques du cuivre (δ65Cu) et du zinc (δ66Zn) d’organes de souris, de différentes souches de nématodes, et de liquides céphalo-rachidiens (LCRs) humains. L’analyse des organes de souris montre que d’importants dérèglements chimiques et isotopiques se développent dans l’organisme avec l’âge, chaque organe ayant sa propre signature élémentaire et isotopique. On observe par exemple une hausse de la concentration en Cu dans le cerveau associée à une diminution de δ65Cu dans le foie au cours du vieillissement. Grâce à l’analyse métabolomique et à l’utilisation de mélanges isotopiques, nous montrons que ces variations pourraient s’expliquer par des dysfonctionnements physiologiques et métaboliques majeurs comme des dérèglements de flux hépatique et/ou la dégradation de la barrière hémato-encéphalique avec l’âge. Cela suggère que l’analyse temporelle du métallome pourrait être un marqueur de l’âge biologique. L’analyse de nématodes a révélée qu’un animal génétiquement modifié pour vivre plus longtemps se distinguait des autres nématodes à plus courte durée de vie par une baisse de sa concentration et de sa composition isotopique en Cu dès son plus jeune âge. Le suivi temporel de ces biomarqueurs devrait permettre de détecter un vieillissement précoce. Finalement, l’analyse de LCRs de patients atteints de SLA, une maladie neurodégénérative sévère pour laquelle il n’existe aucun biomarqueur ni traitement, montre qu’une personne atteinte de SLA se distingue de sujets sains et de patients touchés par la maladie d’Alzheimer par des compositions isotopiques en Cu plus positives. Cette spécificité, laissant entrevoir de nouvelles perspectives concernant l’identification de biomarqueurs spécifiques de la SLA, pourrait s'expliquer par la formation d’agrégats protéiques toxiques dans le cerveau. / Characterized by the progressive and irreversible decline of vital biological functions, ageing is a complex biological process that often comes with neurodegenerative disorders. In 2050, more than 1.5 billion elderly are expected in the world. Improve the quality of life of these ageing people is therefore a major challenge for our society. Still poorly known, the progressive degradation of the metallome is asscociated with ageing and neurodegenerative diseases development and is probably one of their causes. The objective of this study is to better characterize the metallome evolution in two animal models over time i.e. the mouse and the worm as well as in human affected by amyotrophic lateral sclerosis (ALS). To do this, we analyzed twenty trace and major elements as well as the isotopic compositions of copper (δ65Cu) and zinc (δ66Zn) of mouse organs, different strains of nematodes, and human cerebrospinal fluid (CSFs).The analysis of mouse organs shows that important chemical and isotopic changes develop in the body over time, each organ having its own elemental and isotopic signature. For example, we observe an increase of the Cu concentration in the brain associated with a decrease of the δ65Cu in the liver over time. Based on the analysis of metabolomic parameters and the use of isotopic mixings, we show that these variations may be explained by major physiological and metabolic dysfunctions, such as the deregulation of hepatic fluxes and/or the degradation of the blood-brain barrier with age. This suggests that the temporal analysis of the metallome could be used as a potential marker of the biological age.The analysis of nematodes revealed that long-lived animals differ from short-lived nematodes by an early-age decrease in their Cu isotopic composition and Cu concentration. The temporal monitoring of these biomarkers could therefore be used to detect premature ageing conditions.Finally, the analysis of CSFs of patients with amyotrophic lateral sclerosis (ALS), a severe neurodegenerative disease for which there is currently no reliable biomarker or treatment, shows that ALS patients have a higher δ65Cu compared to healthy subjects and Alzheimer’s disease patients. This feature, offering new perspectives to identify ALS-specific biomarkers, may be explained by the formation of toxic protein aggregates in the brain.
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Efeito da esclerose lateral amiotrófica na atuação do sistema estomatognático - análises eletromiográfica, ultrassonográfica, força de mordida e eficiência mastigatória / Effect of amyotrophic lateral sclerosis on the stomatognathic system - electromyographic, ultrasound, bite force and masticatory efficiency analysisLigia Maria Napolitano Gonçalves 02 June 2017 (has links)
A esclerose lateral amiotrófica (ELA) é uma doença neurodegenerativa e progressiva que acomete o sistema neuromotor impedindo a correta funcionalidade da musculatura estriada esquelética. O objetivo deste estudo foi avaliar os músculos masseteres e temporais por meio da eletromiografia de superfície, função mastigatória e ultrassonografia de indivíduos com ELA. A força de mordida molar máxima também foi avaliada. Trinta indivíduos, com idade entre 18 e 68 anos, participaram do estudo. Estes foram distribuídos em dois Grupos: GELA - participantes com ELA, n=15 (idade média de 43,46 ± 3,67 anos) e GC: controle, participantes saudáveis, n=15 (idade média foi de 43,33 ± 3,93 anos). Foi utilizado o eletromiógrafo MyoSystem-I P84 para avaliar a atividade eletromiográfica (EMG) nas condições de repouso mandibular, protrusão, lateralidade direita e esquerda, apertamento dental em contração voluntária máxima com e sem parafilme M®. A eficiência mastigatória foi analisada por meio da integral da envoltória do sinal eletromiográfico dos ciclos mastigatórios na mastigação habitual e não habitual. Para a obtenção da espessura muscular nas condições de repouso e apertamento dental em contração voluntária máxima foi utilizado o aparelho de ultrassom SonoSite NanoMax e para a análise da força de mordida molar máxima direita e esquerda foi utilizado o dinamômetro digital Kratos. Os dados eletromiográficos, ultrassonográficos e de força de mordida molar máxima foram tabulados e submetidos à análise estatística utilizando o software SPSS versão 21.0 (teste t de student; p≤0,05). Verificou-se diferença estatística entre os Grupos ELA e Controle, na condição de repouso mandibular para os músculos masseter direito (p=0,03) e esquerdo (p=0,03); na condição de protrusão para os músculos masseter esquerdo (p=0,00) e temporais direito (p=0,00) e esquerdo (p=0,03); na condição de lateralidade esquerda para os músculos masseter direito (p=0,00), masseter esquerdo (p=0,00) e temporal esquerdo (p=0,00); e na condição de mastigação não habitual para os músculos masseter direito (p=0,00) e temporal direito (p=0,04). De acordo com os resultados obtidos, os indivíduos com ELA apresentaram alteração no padrão eletromiográfico, na função mastigatória e na força de mordida molar máxima, entretanto, o mesmo não foi observado com relação à espessura muscular. Dessa forma, concluiu-se que a doença ELA promoveu alterações funcionais na atuação do complexo sistema estomatognático, como a hiperatividade muscular e diminuição da eficiência mastigatória e da força de mordida, o que compromete muito a qualidade de vida dos indivíduos com ELA. / Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disease that affects the motor neuron system preventing the skeletal striated muscles from functioning properly. The objective of this study was to analyze the masseter and temporal muscles of individuals with ALS by surface electromyography, masticatory function, and ultrasonography. Maximal molar bite force was also evaluated. Thirty individuals, aged 18 to 68 years old, were distributed into two groups: Amyotrophic lateral sclerosis group (mean age of 43.46 ± 3.67; n=15) and Control group (mean age of 43.33 ± 3.93 years; n = 15). A MyoSystem-I P84 electromyographer was used to evaluate the muscle activity in different conditions: rest, protrusion, right laterality, left laterality, tooth clenching in maximal voluntary contraction, with and without Parafilm M®. The efficiency of the masticatory cycle was analyzed by the integral of the signal envelope EMG during habitual and non-habitual mastication. Muscle thickness analyses were performed with a SonoSite NanoMax ultrasound tool. Acquisitions were made during rest, and maximal voluntary contraction. Maximal molar bite force (right and left sides) records were taken with a digital dynamometer Kratos. The electromyographic, ultrasound and maximal molar bite data were tabulated and submitted to statistical analysis using SPSS version 21.0 (Student t-test; p≤0.05). Statistically significant differences were found between the ALS group and controls during rest for the right (p = 0.03) and left masseter muscles (p = 0.03); protrusion for the left masseter (p=0.00) and right (p=000) and left temporal (p=0.03) muscles; during left laterality for the right (p=0.00), left masseter (p=0.00) and left temporal (p=0.00); and during nonhabitual mastication for the right masseter (p=0.00) and right temporal muscles (p=0.04). Based on the results obtained, the individuals with ALS showed different patterns of muscle activity and of masticatory function. Results differed for muscle thickness. In conclusion, ASL promoted functional changes in the stomatognathic system, including muscular hyperactivity and decreased masticatory efficiency and maximal molar bite force, which can affect the quality of life for individuals with ALS.
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Mutações sítio dirigidas na metaloenzima Cu,Zn-superóxido dismutase (SOD1) : efeitos estruturais e funcionais na enzimaManieri, Tania Maria January 2017 (has links)
Orientadora: Profa. Dra. Giselle Cerchiaro / Tese (doutorado) - Universidade Federal do ABC. Programa de Pós-Graduação em Ciência e Tecnologia/Química, 2017. / Entender os mecanismos pelos quais os radicais livres e espécies oxidantes atuam em processos fisiológicos torna-se cada vez mais complexo, especialmente aqueles envolvendo metais de transição com elevada atividade redox como o cobre, ou com funções celulares como o zinco, ambos presentes na metaloenzima Cu,Zn-Superóxido Dismutase (SOD1). Muitos processos envolvendo a sua agregação e função peroxidásica deletéria ainda estão em plena discussão na literatura , mesmo após mais de 40 anos de sua descoberta e caracterização. Nesta área de pesquisa, o papel de mutações na enzima relacionado a casos familiares da doença Esclerose Lateral Amiotrófica (ELA) começou a ser elucidado recentemente, quando soube-se que o tipo de agregação proteica observado e a gravidade da doença apresenta relação com o tipo de mutação na SOD1. Mutações que afetam o modo de coordenação do zinco são as mais intrigantes, pois revelam uma alta patogenicidade da ELA. Sabe-se muito pouco sobre como a SOD1 estaria envolvida com casos de ELA esporádicos, mais comumente encontrados, e nossa proposta esta relacionada a alterações no sítio de ligação ao zinco na enzima, levando a agregações proteicas e formas agressivas da doença. Portanto, neste trabalho de Doutorado, foi estudada a mutação sítio dirigida T135SK136E da SOD1 em relação ao comportamento estrutural e catalítico da proteína. Estudos de Dicroísmo Circular e Ressonância Paramagnética Eletrônica mostraram que a mutação causa alterações estruturais, sem alterar, no entanto, o sítio catalítico da enzima. A proteína mutada apresentou dificuldade em alocar os metais Cobre e Zinco em seus sítios metálicos, porem, mostrou maior atividade catalítica quando comparada à SOD1 nativa. / Mechanisms involving Free-radical and oxidant species are too complexes to understand, especially those which involves high redox activity transition metals ions as copper, or those that are part of cell function, as zinc, both present at metaloenzyme Cu,Zn-Superoxide Dismutase (SOD1). It is known that many process involving SOD1 aggregation and peroxidase activity remain in literature discussion even more than 45 years from its discovery and characterization. In this research area the role of mutation on the enzyme related to cases of familial Amyotrophic Lateral Sclerosis (ALS) begins to be elucidated and mutations related to zinc coordination are more intriguing because they seem to cause a more pathogenic ALS. In this way, in this PhD work we studied the site-direct mutation T135SK136E on SOD1, taking special attention to zinc site, to verify how the enzyme acts catalytic and structurally. Circular Dichroism and Electronic Paramagnetic Resonance assays have shown that the mutation causes structural alterations, without altering, however, the catalytic site of the enzyme. The mutated protein presented difficulty in allocating the copper and zinc metals in their metallic sites, but showed greater catalytic activity when compared to wild type SOD1.
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