Intravenous immunoglobulin (IVIg) has been used to treat a variety of autoimmune disorders including multiple sclerosis (MS); however, its mechanism of action remains elusive. Our results demonstrate a novel finding wherein IVIg treatment induces a dramatic surge (>1000-fold increase) in the levels of IL-11 in the circulation and that the liver is the organ of increased IL-11 transcription. Furthermore, we show that IL-11Rα knockout mice, although initially protected, become resistant to protection by IVIg during experimental autoimmune encephalomyelitis (EAE) and develop disease with a similar incidence and severity as control-treated IL-11Rα-/- mice. The inability of IVIg to prevent EAE in IL-11Rα-/- mice correlated with a failure of this agent to decrease IL-17 production by myelin-reactive T-cells in the draining lymph nodes. Finally, we show that IL-11 can directly inhibit IL-17 production by lymph node cells in culture. Together, these results implicate IL-11 as an important immune effector of IVIg in the amelioration of EAE.

Disease maps are geographical maps that display local estimates of disease risk. When the disease is rare, crude risk estimates can be highly variable, leading to extreme estimates in areas with low population density. Bayesian hierarchical models are commonly used to stabilize the disease map, making them more easily interpretable. By exploiting assumptions about the correlation structure in space and time, the statistical model stabilizes the map by shrinking unstable, extreme risk estimates to the risks in surrounding areas (local spatial smoothing) or to the risks at contiguous time points (temporal smoothing). Extreme estimates that are based on smaller populations are subject to a greater degree of shrinkage, particularly when the risks in adjacent areas or at contiguous time points do not support the extreme value and are more stable themselves. / A common goal in disease mapping studies is to identify areas of elevated risk. The objective of this thesis is to compare the accuracy of several fully Bayesian hierarchical models in discriminating between high-risk and background-risk areas. These models differ according to the various spatial, temporal and space-time interaction terms that are included in the model, which can greatly affect the smoothing of the risk estimates. This was accomplished with simulations based on the cervical cancer rate of Kentucky and at-risk person-years of the state of Kentucky's 120 counties from 1995 to 2002. High-risk areas were 'planted' in the generated maps that otherwise had background relative risks of one. The various disease mapping models were applied and their accuracy in correctly identifying high- and background-risk areas was compared by means of Receiver Operating Characteristic curve methodology. Using data on Multiple Sclerosis (MS) on the island of Sardinia, Italy we apply the more successful models to identify areas of elevated MS risk.

520 L $$aIn the CNS, myelination of axons is essential for the rapid conduction of impulses down the nerve. In demyelinated or failing axons however, conduction is less efficient and requires more energy. The principal function of mitochondria is to provide energy for the axon but in doing so they generate most of the intra-axonal reactive oxygen species (ROS). Therefore and increased energy requirement will promote an increased production of ROS which could lead to significant damage to essential DNA, proteins and lipids and could eventually damage the axon. This thesis investigates the mitochondrial involvement in axonal pathology in the CNS diseases, multiple sclerosis (MS), autosomal dominant optic atrophy (ADOA) and tosomal dominant optic atrophy with cataract (ADOAC).

No description available.

Neuropathic pain (NPP) is a chronic syndrome suffered by patients with multiple sclerosis (MS), for which there is no cure. Underlying cellular mechanisms involved in its pathogenesis are multifaceted, resulting in significant challenges in its management. In addition to its complex pathophysiology, the clinical management of MS-induced NPP is further complicated by the lack of clinical therapeutics trials specific to this population. The primary aim of the work underlying this thesis was to contribute to the evidence-based management of individuals with MS-induced NPP through the completion of two clinical therapeutics trials in this population. A secondary aim was to describe pain variability in this patient population through the development and validation of a pain variability algorithm tool. Resulting from this work, we demonstrated that nabilone – a synthetic oral cannabinoid – represents an effective, well-tolerated and novel treatment for MS-induced NPP. Additionally, we show that the SSRI paroxetine was poorly tolerated in our patient population, with a correspondingly high attrition rate. As a result, we were unable to determine any treatment effect in this trial due to insufficient recruitment due to drop-out. Lastly, we were able to define and describe pain instability in this cohort, noting that approximately 30% of individuals with MS-induced NPP experiencing highly variable daily pain. The results of these projects provide novel information for this patient population. Patients currently living with the daily burden of MS-induced NPP would benefit from additional trials ensuing from this, and other, research in order to initiate a momentum for much-needed clinical research in this complicated patient cohort.

A mutation in ER membrane protein VAPB is responsible for causing a familial form of ALS (ALS8). The VAPB-P56S mutation causes protein aggregation and a nuclear envelope defect, where retrograde transport is disrupted. Over-expression of a FFAT peptide from OSBP1 reduces the size of VAPB-P56S aggregates and restores retrograde transport. A screen was performed on FFAT-motif containing ORPs to determine if any could rescue the mutant phenotype. ORP3 successfully reduced aggregate size and restored transport to the nuclear envelope. ER membrane protein Sac1, a PI4P phosphatase cycles between the ER and Golgi and becomes trapped in expanded ERGIC compartments with VAPB-P56S. Loss of Sac1 in the ER leads to an increase in intracellular PI4P. ORP3 may increase Sac1 phosphatase activity by acting as a lipid sensor. We propose that VAPB, Sac1 and ORP3 are interacting partners that together modulate levels of PI4P. Disruptions in the gradient of PI4P may result in the vesicle trafficking defects observed in VAPB-P56S cells.

Multiple Sclerosis (MS) is an autoimmune disease of the central nervous system (CNS). Antigen induced activation of Th1 cells in the peripheral blood leads to elevated production of inflammatory cytokines such as tumor necrosis factor alpha (TNF-α) that have been directly linked to disease induction and neuropathic pain. It was hypothesized that following antigenic induction, cytokines gain access to the spinal cord and participate in direct cellular interaction with dorsal horn neurons. Using an animal model of MS, we show that TNF-α gene and protein expression in the dorsal root ganglia (DRG) and spinal cord tissue is increased in the active group. In addition, our findings show TNF-α mRNA expression in the dorsal root entry point. Therefore, our results support the hypothesis that antigen induced DRG derived TNF-α can transport to the spinal cord via the dorsal roots and is involved in the underlying pathogenesis of MS induced neuropathic pain.

In order to assess cognitive function in multiple sclerosis (MS) and the effect of cholinergic modulation, experiments were conducted using functional magnetic resonance imaging (fMRI) to assess the brain activation during cognitive tasks. A study comparing the processing of verbal working memory with an N-back task found that patients showed smaller increase in activation than healthy controls with greater task difficulty, suggesting a reduced functional reserve. Controls and patients showed differences of correlations between brain regions activated. Interactions between prefrontal regions may provide an adaptive mechanism that could limit clinical expression of the disease distinct from recruitment of novel processing regions. The effect of Rivastigmine on the cognitive processing in MS patients was tested in a longitudinal study, involving serial fMRI scans. Changes in the brain activation patterns were demonstrated with drug administration, without any changes in behavioural measures. Rivastigmine may act to increase the functioning of the normal neural network reducing the need for previously recruited compensatory mechanisms in MS patients. A study on healthy subjects examined the effect of cholinergic inhibition on cognitive processing and brain activation. Changes in functional activation due to Hyoscine during verbal working memory were found analogous to that in MS patients without any changes in behavioural measures. Processes that potentially impair brain cognitive function may recruit similar compensatory functional adaptive mechanisms. Studies on rats and MS patients explored the effect of Rivastigmine on the relationship of the BOLD fMRI signal with the underlying neural activity. Rivastigmine may be influencing the cortical excitability after direct cortical stimulation but showed only a small effect on the BOLD signal under more physiological neural activity. The neural activity in response to visual stimulation is slightly increased with Rivastigmine in MS patients, a change not detected with functional imaging. These studies suggest that changes in BOLD signal do represent sufficiently large changes of underlying neural activity in the presence of Rivastigmine. The relationship of damage in MS to measures of connectivity was studied using diffusion tensor imaging (DTI). Correlation was found between measures of connectivity and callosal size, a measure of fibre loss. The distribution of lesions was spatially correlated with changes in connectivity due to MS. Thus DTI could be utilized to explore the connectivity changes associated with MS, and the relationship with changes in functional activation.

In den letzten Jahren ist zunehmend deutlich geworden, dass die Multiple Sklerose (MS) nicht nur eine Erkrankung der weißen Substanz des zentralen Nervensystems ist, sondern auch häufig und beträchtlich die graue Substanz in allen klinischen Verlaufsformen betrifft. Besonders die kortikale Pathologie mit entmarkten Läsionen wurde durch verbesserte immunhistochemische Färbetechniken und neuen magnetresonanztomographischen Verfahren ausführlicher untersucht. MS-Patienten leiden klinisch oft an körperlichen Beeinträchtigungen und neuropsychologischen Defiziten, welche die Lebensqualität beeinflussen. Diese Symptome wurden mit Läsionen in der grauen Substanz assoziiert. Mechanismen, die zu dieser Pathologie führen, müssen daher aufgeklärt werden um vorbeugende oder akute Behandlungen entwickeln zu können. Zur pathologischen Untersuchung der grauen Substanz werden angemessene Tiermodelle benötigt, welche die humane kortikale Pathologie wiederspiegeln. Das am häufigsten verwendete Tiermodell in MS-Studien ist die Experimentelle Autoimmune Enzephalomyelitis (EAE), die in ihrem ‘konventionellen’ Immunisierungsprotokoll nur selten den zerebralen Kortex betrifft. Ein EAE-Modell mit Einbezug des Kortex, das MS-Läsionen nachahmt, wurde in Ratten beschrieben. Hierzu wurden proinflammatorische Zytokine in eine vorbestimmte kortikale Region injiziert. Da spezifisch genveränderte Rattenstämme fehlen um die Mechanismen der Pathologie in der grauen Substanz zu untersuchen ist es notwendig das Tiermodell in Mäusen zu entwickelen. Das Ziel dieses Projekts war die Entwicklung eines kortikalen EAE-Mausmodells sowie dessen histopathologische Charakterisierung. Desweiteren wurde kortikales Gehirnmaterial von MS-Patienten im späten Krankheitsstadium auf dendritische Patholgie untersucht. Die kortikale EAE wurde in Myelin Oligodendrozyten Glykoprotein (MOG)-immunisierten BiozziABH (hohe Antikörper) und F1 Nachkommen, die aus BiozziABH und Mäusen mit einem C57BL6/J-Hintergrund generiert worden sind, durch die intrakortikale Injektion von TNF-α und IFN-γ induziert. Histologische Untersuchungen zeigten eine ausgedehnte subpiale Entmarkung und Entzündung im Kortex drei Tage nach der Zytokininjektion in der betroffenen Hirnhälfte. Die Entzündung ging innerhalb von drei Wochen fast vollständig zurück und entmarkte Regionen wiesen teilweise eine Remyelinisierung auf. Axone blieben in läsionalen Regionen erhalten und neuronaler Verlust wurde im Kortex nicht beobachtet. Desweiteren wurde eine Methode etabliert, die es erlaubt detailliert dendritische Pathologien in der Maus zu untersuchen. Kortex-enthaltenes Autopsiematerial von progressiven MS-Patienten mit langandauerndem Krankheitsverlauf zeigte einen Verlust von dendritischen Dornfortsätzen (Spines) in Neurone, die in den unteren korikalen Layern sowohl in chronisch entmarkten Läsionen als auch im umliegenden normal erscheinendem Gewebe der grauen Substanz lokalisiert waren. Im vorliegenden Projekt wurde ein kortikales EAE-Mausmodell entwickelt, das die humane MS-Pathologie der grauen Substanz in frühen Krankheitsstadien wiederspiegelt. Dieses Modell ist für Untersuchungen früher Mechanismen im entmarkten Kortex und für die Erprobung therapeutischer Behandlungen wie die Erhöhung der Remyelinisierung nützlich. Darüberhinaus wurde ein ausgedehnter Verlust dendritischer Dornfortsätze im zerebralen Kortex in chronischen MS-Patienten gezeigt, der auf oft beobachtete neuropsychologische Defizite zurückgeführt werden könnte.

Peripherin is a type III intermediate filament protein that is predominately expressed in the peripheral nervous system and in subsets of efferent projections in the central nervous systems. While the exact role of peripherin remains unclear, it is found upregulated after traumatic neuronal injury and in the devastating neurodegenerative disease amyotrophic lateral sclerosis (ALS). Interestingly, peripherin overexpressing transgenic mice succumb to motor neuron disease with pathological hallmarks reminiscent of those found in ALS. Pathological peripherin abnormalities occur with high frequency in both familial and sporadic forms of ALS, with peripherin found associated with the majority intracellular inclusions present within degenerating motor neuron populations. The findings of peripherin mutations in sporadic ALS have reinforced the importance of peripherin as a prospective etiological or propagative factor of disease pathogenesis. Surprisingly, inherited peripherin gene mutations have not been identified; as such, understanding the post-transcriptional mechanism at which peripherin imparts its effect(s) is considered a key goal and represents a pathological point-of-convergence for an otherwise complex, multifaceted disease. Prior to the commencement of this work, our group identified the presence of an abnormal peripherin alternative splice variant upregulated in ALS. In doing so, we consistently observed the presence of a second peripherin species of ~45 kDa on immunoblots of cell lysates derived from full-length peripherin transfections. Here, we identified this protein as a constitutively expressed isoform, termed Per-45, that arises from alternative translation and that is required for normal filament assembly: changes to the normal isoform expression pattern are associated with malformed filaments and intracellular inclusions. In lieu of the possibility of distinct peripherin intra-isoform associations, we identified isoform-specific expression and ratio changes in traumatic neuronal injury, in mouse models of motor neuron disease, and in ALS. Finally, we explored the interrelationships between peripherin isoform expression, protein aggregation, and neuritic outgrowth by linking these phenotypes with major pathogenic features associated with ALS, including in vitro models of oxidation, glutamate excitotoxicity, and neuroinflammation. Overall, this thesis provides exciting new insight into our knowledge of basic IF biology and the role of peripherin isoforms in injury and in motor neuron disease.