Immunoglobulin-mediated inhibition of amyloid fibril formation in vivo is a promising strategy for the treatment of protein misfolding diseases such as the amyloidoses. Here we focus on transthyretin amyloidoses, a group of protein conformation diseases caused by the misfolding of the serum protein transthyretin into fibrillar structures that deposit in specific organs and tissues—often with serious pathological consequences. Using a structure-guided immunological approach, we report a novel antibody that selectively recognizes monomeric, misfolded conformations of transthyretin in vitro. Raised to an epitope normally buried in the native form of transthyretin, this antibody was found to suppress transthyretin fibrillogenesis at substoichiometric concentrations in vitro. Overall, the selectivity and inhibitory nature of the antibody signals the potential use of conformation specific antibodies in the diagnosis and treatment of transthyretin amyloidoses, conditions which remain difficult to treat and are widely under/misdiagnosed at the current time.

Hook-Proteine spielen eine wichtige Rolle im intrazellulären Transport. Sie binden n-terminal Mikrotubuli, haben eine coiled-coil-Domäne und binden c-terminal Organellen. Da aus humanen Hirnschnitten eine Kolokalisation mit den bei Alzheimerscher Erkrankung auftretenden neurofibrillären Tangles bekannt war, erscheint eine weitere Untersuchung der Expression und Lokalisation von Hook-Proteinen im zentralen Nervensystem interessant. Hierzu wurde die Expression der humanen Hook-Proteine mittels real-time RT-PCR quantifiziert und die Lokalisation der Hook-Proteine in verschiedenen transgenen Mausmodellen der Tauopathie mittels Immunhistochemie dargestellt. Außerdem wurde die cDNA der Hook-Proteine mittels PCR auf alternatives Spleißen untersucht.

Lead (Pb) is one of the most well known toxic heavy metals in human beings and animals, which leads to toxic neurological disorders, cognitive problems, learning and memory disabilities. Epidemiological studies revealed that chronic lead exposure is one of the environmental risk factors which may cause Alzheimer¡¦s Disease, which were speculated for the observation of cellular necrosis, apoptosis, and £]-amyloid deposition frequently occuring altogether after chronic lead exposure. Recent studies have shown that the £]-amyloid formed during autophagic turnover of APP-rich organelles supplied by both autophagy and endocytosis. Therefore, we will conduct the new perspective for studying the possible role of autophagy on amyloidogensis disorders after lead exposure. SH-SY5Y human neuroblastoma cells, used in this study, were differentiated to a neuronal phenotype by retinoic acid (RA) to the culture medium at 10 £gM for 1, 2, 3 and 4 days. Doses of lead acetate with of lead acetate were 5 £gM and applied to the neuronal culture and then cell viability measurement by MTT assay. The apoptotic effect of non-differentiation and differentiation neuroblastoma cells after lead exposure was determined by cleaved DNA fragments. Furthermore, APP, intracellular A£]1-40 and A£]1-42 expression were quantified by Real-time PCR and ELISA, respectively. The autophagy process and variation of total and phosphorylated mammalian target of rapamycin (mTOR) forms were determined after lead exposure in non-differentiation and differentiation neuroblastoma cells by western blot. The results indicate that lead exposure enhances autophagy response in both non-differentiation and differentiation SH-SY5Y cells, which might cause neuronal apoptosis associated with £]-amyloidgenesis. Otherwise, lead exposure resulted in the inhibition of mTOR signaling, which correlated with the autophagic process. Besides, in our studies, non-differentiated cells exhibited more toxic vulnerability than RA induced differentiated neuron is congruous to previous finding that lead exposure during fetal development might be a potential risk factor for AD in the adulthood.

Die Liquordiagnostik ist neben der Anamnese, neuropsychologischen Testung und der Bildgebung eine wichtige Säule in der Demenzdiagnostik. Bisher diente sie vorrangig dazu, Demenzen von nicht-dementiellen Erkrankungen abzugrenzen. Die vorliegende Arbeit beschäftigt sich mit der Trennschärfe der Kombination der Liquormarker Aß 1-42, T-Tau und P-Tau in der Differenzialdiagnostik innerhalb verschiedener Demenzformen. So bestätigten wir die liquorgestützte Alzheimerdiagnose bei erhöhten Werten von T-Tau und P-Tau, sowie bei erniedrigtem Aß 1-42. Bei den alpha-Synucleinopathien ließ sich bei einem normalen Befund eine Demenz bei Parkinson von einer Lewy-Body-Demenz abgrenzen (Aß erniedrigt). Vaskuläre Demenzen ließen sich durch ein normales Liquorprofil vom M. Alzheimer trennen; nach ischämischen Schlaganfällen jedoch traten stark erhöhte Werte des neuronalen Destruktionsmarkers T-Tau auf (abhängig von Größe und Alter des Infarktes) sodass hier die Aussagekraft eines Liquorbefundes bei Z.n. Schlaganfall gemindert war. Eine Lumbalpunktion bei Infarktnachweis in Anamnese oder Bildgebung sollte in ausreichend zeitlichen Abstand erfolgen (abhängig von Infarktgröße bis 6 Monate). Eine korrekte Therapie hängt von einer korrekten Diagnose ab, diese kann durch Liquordiagnostik unterstützt werden.

<p>Hypoxia is a profound stressor of the central nervous system implicated in numerous neurodegenerative diseases. While it is increasingly evident that the early effects of hypoxia cause impairment at the level of the axon, the precise mechanisms through which hypoxia compromises axonal structure and function remain unclear. However, links between hypoxia-induced axonopathic disease and the amyloid cascade, as well as the upregulation of amyloid precursor protein (APP) and amyloid beta (A&beta;) by hypoxic stress, give rise to the hypothesis that proteolytic cleavage of APP into A&beta; may be specifically responsible for axonopathy under conditions of hypoxia. </p><p>The goal of this dissertation was thus to understand dependence of hypoxia-induced axonal morphological and functional impairment on APP cleavage and the production of A&beta;. I have developed a model of hypoxia-induced axonopathy in retinal explants. Using this model, I have experimentally addressed the core hypothesis that APP cleavage, and in particular the formation of A&beta;, is necessary and sufficient to mediate morphological and functional axonopathy caused by hypoxia. I have found that there is a dissociation between the mechanisms responsible for hypoxia-induced morphological and functional impairment of the axon in the explanted retina, with the former being dependent on APP-to-A&beta; processing and the latter likely being dependent on cleavage of a non-APP substrate by the enzyme BACE1. These findings shed light on mechanisms of hypoxia-induced axonopathy.</p> / Dissertation

Dissertation (Ph.D.)--University of South Florida, 2007. / Title from PDF of title page. Document formatted into pages; contains 142 pages. Includes vita. Includes bibliographical references.

Thesis (Ph. D.)--Case Western Reserve University, 2007. / [School of Medicine] Department of Neurosciences. Includes bibliographical references.

Diss. (sammanfattning) Stockholm : Karol. inst., 2004. / Härtill 5 uppsatser.

Diss. (sammanfattning) Umeå : Univ., 2007. / Härtill 5 uppsatser.

Dissertation (Ph.D.)--University of South Florida, 2007. / Includes vita. Includes bibliographical references (leaves 128-139). Also available online.