Mucopolysaccharidosis type IIIB (MPSIIIB) is a lysosomal storage disease (LSD) characterized by accumulation of heparan sulfate oligosaccharides (HSO), which results in progressive mental retardation, neurodegeneration and premature death in children. The underlying mechanisms are poorly understood. Coming to a better understanding of the pathophysiology of MPSIIIB has become a necessity to assess the efficacy of gene therapy treatment regarding loss of neuronal plasticity, and to define the best conditions for treatment. To address the link between HSO accumulation and downstream pathological events, new cell models of MPSIIIB were created. First, induced pluripotent stem cells (iPSc) were generated from fibroblasts of affected children, followed by differentiation of patient-derived iPSc into a neuronal progeny. Second, a HeLa cell model was created in which expression of shRNAs directed against a-N-acetylglucosaminidase (NAGLU), the deficient enzyme in MPSIIIB, is induced by tetracycline. Success in the isolation of these different models was pointed by the presence of cardinal features of MPSIIIB cell pathology. Studies in these models showed that: I) HSO excreted in the extracellular matrix modifies cell perception of environmental cues, affecting downstream signalling pathways with consequences on the Golgi morphology. II) Accumulation of intracellular storage vesicles, a hallmark of LSDs is due to overexpression of the cis-Golgi protein GM130 and subsequent Golgi alterations. It is likely that these vesicles are abnormal lysosomes formed in the cis- and medial-Golgi which are misrouted at an early step of lysosome biogenesis, giving rise to a dead-end compartment. III) Other cell functions controlled by GM130 are affected, including centrosome morphology and microtubule nucleation. These data point to possible consequences on cell polarization, cell migration and neuritogenesis.

Descrevem-se os achados epidemiológicos, clínico-patológicos, ultra-estruturais e lectino-histoquímicos de herbívoros intoxicados naturalmente por Sida carpinifolia no Estado do Rio Grande do Sul, Brasil. Este estudo incluiu a elaboração de três artigos. Foi realizado um estudo retrospectivo de intoxicação natural por Sida carpinifolia em bovinos no Rio Grande do Sul, outro relata pela primeira vez uma intoxicação natural por esta planta em um animal silvestre e o terceiro artigo relata os achados patológicos observados em fetos de fêmeas caprina e bovina que foram intoxicadas experimentalmente e naturalmente respectivamente por Sida carpinifolia. No primeiro artigo foram afetados cinco bovinos entre os anos de 2001 a 2008. O quadro clínico foi caracterizado por emagrecimento, incoordenação, dificuldade de locomoção, tremores generalizados, quedas frequentes e morte. Microscopicamente as principais alterações foram vacuolização dos neurônios de Purkinje do cerebelo, vacuolização das células acinares do pâncreas e das células foliculares da tireoide. No segundo artigo, o cervídeo desenvolveu uma síndrome neurológica caracterizada por fraqueza muscular, tremores de intensão, déficit visual, quedas, postura e comportamento anormal. Os principais achados microscópicos foram vacuolização citoplasmática nos neurônios de Purkinje do cerebelo. No terceiro artigo duas cabras prenhes foram intoxicadas experimentalmente com Sida carpinifolia nas doses de 10 e 13 g/kg respectivamente durante 30 dias e foram acompanhados durante 15 dias após o consumo da planta. Após este período foram eutanasiadas e necropsiadas. Adicionalmente foi incluído um feto bovino no qual a mãe havia sido intoxicada naturalmente por S. carpinifolia. As principais alterações microscópicas observadas nos fetos foram vacuolização do epitélio dos túbulos renais, das células foliculares da tireoide e cerebelo com discreta vacuolização dos neurônios de Purkinje. Na microscopia eletrônica de todos os casos foi observado vacúolos contendo material finamente granulado e delimitado por membrana. Na lectinahistoquímica dos bovinos, do cervídeo e dos fetos observou-se marcação em neurônios com as lectinas Concanavalia ensiformis (Con-A), Triticum vulgaris (WGA) e Succinyl WGA (sWGA). / Describes the epidemiological, clinical, pathological, ultrastructural and lectinhistochemical herbivore naturally poisoned by Sida carpinifolia in Rio Grande do Sul, Brazil. This study included the preparation of three articles. We conducted a retrospective study of natural poisoning by Sida carpinifolia in cattle in Rio Grande do Sul and the other reports for the first time a natural poisoning by this plant in a wild animal. The third article reports the pathologic findings observed in fetuses of female goats and cattle that were naturally and experimentally poisoned by Sida carpinifolia respectively. In the first paper were affected five cattle between the years 2001 to 2008. The clinical picture was characterized by weight loss, incoordination, difficulty walking, generalized tremors, frequent falls and death. Microscopically the main changes were vacuolation of the Purkinje neurons of cerebellum, vacuolization of acinar cells of the pancreas and thyroid follicular cells. In the second paper, the deer developed a neurological syndrome characterized by muscular weakness, intention tremors, visual and standing-up deficits, falls, and abnormal behavior and posture. The main microscopic findings were vacuolation in Purkinje neurons of cerebellum. In the third paper were two pregnant goats experimentally poisoned with Sida carpinifolia in doses of 10 and 13 g / kg for 30 days and were followed for 15 days after consumption of the plant. Additionally included a bovine fetus where the mother had been poisoned by S. carpinifolia. The main microscopic changes observed in the fetuses were vacuolation of the epithelium of renal tubules, thyroid follicular cells in the cerebellum and mild vacuolation of Purkinje neurons. On electron microscopy all cases was observed vacuoles containing finely granular material and bordered by membrane. In lectin-histochemistry of cattle, the deer and fetuses was observed in neurons marking to lectins Concanavalia ensiformis (Con-A), Triticum vulgaris (WGA) e Succinyl WGA (sWGA).

Descrevem-se os achados epidemiológicos, clínico-patológicos, ultra-estruturais e lectino-histoquímicos de herbívoros intoxicados naturalmente por Sida carpinifolia no Estado do Rio Grande do Sul, Brasil. Este estudo incluiu a elaboração de três artigos. Foi realizado um estudo retrospectivo de intoxicação natural por Sida carpinifolia em bovinos no Rio Grande do Sul, outro relata pela primeira vez uma intoxicação natural por esta planta em um animal silvestre e o terceiro artigo relata os achados patológicos observados em fetos de fêmeas caprina e bovina que foram intoxicadas experimentalmente e naturalmente respectivamente por Sida carpinifolia. No primeiro artigo foram afetados cinco bovinos entre os anos de 2001 a 2008. O quadro clínico foi caracterizado por emagrecimento, incoordenação, dificuldade de locomoção, tremores generalizados, quedas frequentes e morte. Microscopicamente as principais alterações foram vacuolização dos neurônios de Purkinje do cerebelo, vacuolização das células acinares do pâncreas e das células foliculares da tireoide. No segundo artigo, o cervídeo desenvolveu uma síndrome neurológica caracterizada por fraqueza muscular, tremores de intensão, déficit visual, quedas, postura e comportamento anormal. Os principais achados microscópicos foram vacuolização citoplasmática nos neurônios de Purkinje do cerebelo. No terceiro artigo duas cabras prenhes foram intoxicadas experimentalmente com Sida carpinifolia nas doses de 10 e 13 g/kg respectivamente durante 30 dias e foram acompanhados durante 15 dias após o consumo da planta. Após este período foram eutanasiadas e necropsiadas. Adicionalmente foi incluído um feto bovino no qual a mãe havia sido intoxicada naturalmente por S. carpinifolia. As principais alterações microscópicas observadas nos fetos foram vacuolização do epitélio dos túbulos renais, das células foliculares da tireoide e cerebelo com discreta vacuolização dos neurônios de Purkinje. Na microscopia eletrônica de todos os casos foi observado vacúolos contendo material finamente granulado e delimitado por membrana. Na lectinahistoquímica dos bovinos, do cervídeo e dos fetos observou-se marcação em neurônios com as lectinas Concanavalia ensiformis (Con-A), Triticum vulgaris (WGA) e Succinyl WGA (sWGA). / Describes the epidemiological, clinical, pathological, ultrastructural and lectinhistochemical herbivore naturally poisoned by Sida carpinifolia in Rio Grande do Sul, Brazil. This study included the preparation of three articles. We conducted a retrospective study of natural poisoning by Sida carpinifolia in cattle in Rio Grande do Sul and the other reports for the first time a natural poisoning by this plant in a wild animal. The third article reports the pathologic findings observed in fetuses of female goats and cattle that were naturally and experimentally poisoned by Sida carpinifolia respectively. In the first paper were affected five cattle between the years 2001 to 2008. The clinical picture was characterized by weight loss, incoordination, difficulty walking, generalized tremors, frequent falls and death. Microscopically the main changes were vacuolation of the Purkinje neurons of cerebellum, vacuolization of acinar cells of the pancreas and thyroid follicular cells. In the second paper, the deer developed a neurological syndrome characterized by muscular weakness, intention tremors, visual and standing-up deficits, falls, and abnormal behavior and posture. The main microscopic findings were vacuolation in Purkinje neurons of cerebellum. In the third paper were two pregnant goats experimentally poisoned with Sida carpinifolia in doses of 10 and 13 g / kg for 30 days and were followed for 15 days after consumption of the plant. Additionally included a bovine fetus where the mother had been poisoned by S. carpinifolia. The main microscopic changes observed in the fetuses were vacuolation of the epithelium of renal tubules, thyroid follicular cells in the cerebellum and mild vacuolation of Purkinje neurons. On electron microscopy all cases was observed vacuoles containing finely granular material and bordered by membrane. In lectin-histochemistry of cattle, the deer and fetuses was observed in neurons marking to lectins Concanavalia ensiformis (Con-A), Triticum vulgaris (WGA) e Succinyl WGA (sWGA).

La mucopolysaccharidose IIIB (MPSIIIB) est une maladie de surcharge lysosomale (MSL) causée par une accumulation d’oligosaccharides d’héparane sulphate (OHS), induisant chez les enfants atteints un retard mental progressif, une neurodégénérescence et une mort prématurée. Les mécanismes physiopathologiques impliqués sont mal compris. Il est nécessaire d’élucider ces mécanismes, afin d’évaluer l’efficacité d’un traitement par thérapie génique en regard de la perte de la plasticité neuronale, et pour définir les meilleures conditions de traitement. Pour cela, de nouveaux modèles cellulaires de la maladie ont été créés. Des cellules souches pluripotentes induites ont été générées à partir de fibroblastes de patients, lesquelles ont ensuite été différenciées en une lignée neuronale. Un modèle HeLa a également été créé dans lequel l’expression de shRNAs dirigés contre la a-N-acétylglucosaminidase (NAGLU), l’enzyme manquante dans la MPSIIIB, est induite par la tétracycline. Ces modèles ont été isolés avec succès, et présentent les caractéristiques pathologiques fondamentales de la MPSIIIB. L’étude de ces modèles a montré que : I) Les OHS excrétés dans la matrice extracellulaire modifient la perception cellulaire des signaux environnementaux, affectant les voies de signalisation en aval avec des conséquences sur la morphologie du Golgi. II) L’accumulation de vésicules de stockage intracellulaires qui caractérisent les MSLs est due à la surexpression de la protéine cis-golgienne GM130 et aux altérations du Golgi qui en résultent. Ces vésicules sont possiblement des lysosomes anormaux formés dans le Golgi cis et médian qui sont déroutés à une étape précoce de la biogenèse du lysosome, donnant naissance à un compartiment « cul-de-sac ». III) D’autres fonctions cellulaires contrôlées par GM130 sont affectées dont la morphologie du centrosome ou la nucléation des microtubules. Ces données suggèrent de possibles conséquences sur la polarisation et la migration cellulaire, et la neuritogenèse. / Mucopolysaccharidosis type IIIB (MPSIIIB) is a lysosomal storage disease (LSD) characterized by accumulation of heparan sulfate oligosaccharides (HSO), which results in progressive mental retardation, neurodegeneration and premature death in children. The underlying mechanisms are poorly understood. Coming to a better understanding of the pathophysiology of MPSIIIB has become a necessity to assess the efficacy of gene therapy treatment regarding loss of neuronal plasticity, and to define the best conditions for treatment. To address the link between HSO accumulation and downstream pathological events, new cell models of MPSIIIB were created. First, induced pluripotent stem cells (iPSc) were generated from fibroblasts of affected children, followed by differentiation of patient-derived iPSc into a neuronal progeny. Second, a HeLa cell model was created in which expression of shRNAs directed against a-N-acetylglucosaminidase (NAGLU), the deficient enzyme in MPSIIIB, is induced by tetracycline. Success in the isolation of these different models was pointed by the presence of cardinal features of MPSIIIB cell pathology. Studies in these models showed that: I) HSO excreted in the extracellular matrix modifies cell perception of environmental cues, affecting downstream signalling pathways with consequences on the Golgi morphology. II) Accumulation of intracellular storage vesicles, a hallmark of LSDs is due to overexpression of the cis-Golgi protein GM130 and subsequent Golgi alterations. It is likely that these vesicles are abnormal lysosomes formed in the cis- and medial-Golgi which are misrouted at an early step of lysosome biogenesis, giving rise to a dead-end compartment. III) Other cell functions controlled by GM130 are affected, including centrosome morphology and microtubule nucleation. These data point to possible consequences on cell polarization, cell migration and neuritogenesis.

Background: Lysosomal storage diseases (LSD) often manifest with cherry red macular spots. Diagnosis is based on clinical features and specific biochemical and enzymatic patterns. In uncertain cases, genetic testing with next generation sequencing can establish a diagnosis, especially in milder or atypical phenotypes. We report on the diagnostic work-up in a boy with sialidosis type I, presenting initially with marked cherry red macular spots but non-specific urinary oligosaccharide patterns and unusually mild excretion of bound sialic acid. Methods: Biochemical, enzymatic and genetic tests were performed in the patient. The clinical and electrophysiological data was reviewed and a genotype-phenotype analysis was performed. In addition a systematic literature review was carried out. Case report and results: Cherry red macular spotswere first noted at 6 years of age after routine screening myopia. Physical examination, psychometric testing, laboratory investigations aswell as cerebralMRIwere unremarkable at 9 years of age. So far no clinical myoclonic seizures occurred, but EEG displays generalized epileptic discharges and visual evoked potentials are prolonged bilaterally. Urine thin layer chromatography showed an oligosaccharide pattern compatible with different LSD including sialidosis, galactosialidosis, GM1 gangliosidosis or mucopolysaccharidosis type IV B. Urinary bound sialic acid excretion was mildly elevated in spontaneous and 24 h urine samples. In cultured fibroblasts, α-sialidase activity was markedly decreased to b1%; however, bound and free sialic acid were within normal range. Diagnosis was eventually established by multigene panel next generation sequencing of genes associated to LSD, identifying two novel, compound heterozygous variants in NEU1 gene (c.699CNA, p.S233R in exon 4 and c.803ANG; p.Y268C in Exon 5 in NEU1 transcriptNM_000434.3), leading to amino acid changes predicted to impair protein function. Discussion: Sialidosis should be suspected in patients with cherry red macular spots, even with non-significant urinary sialic acid excretion. Multigene panel next generation sequencing can establish a definite diagnosis, allowing for counseling of the patient and family.

Submitted by Sandra Pereira (srpereira@ufrrj.br) on 2018-04-11T13:17:41Z No. of bitstreams: 1 2010 - Bruno Leite dos Anjos.pdf: 12893665 bytes, checksum: 99b4dd0f8ecdebb1f227aa0522ac061f (MD5) / Made available in DSpace on 2018-04-11T13:17:42Z (GMT). No. of bitstreams: 1 2010 - Bruno Leite dos Anjos.pdf: 12893665 bytes, checksum: 99b4dd0f8ecdebb1f227aa0522ac061f (MD5) Previous issue date: 2010-08-17 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico, CNPq, Brasil. / Cases of diseases induced by toxic plants in domestic herbivores are well reported throughout the world and have been studied also in Brazil. However, not much is known about the epidemiological and pathological aspectos of these conditions in free-living wildlife or bred in captivity. The risk for developing the toxicoses in captivity has been increasing, since natural habitats are destroyed by human action, and more centers of wildlife conservation and zoological comes are created. This study describes the epidemiological, biological and clinicopathological, lectin-histochemical and ultrastructural aspects of an outbreak of lysosomal storage disease of oligosaccharides induced by ingestion of Sida carpinifolia in young Sambar deer (Cervus unicolor) in the Rio-Zoo Foundation in the State of Rio de Janeiro, Brazil. Nine deer showed neurological signs characterized by motor and proprioceptive deficits. Then neurological signs were mainly depression, incoordination, dysmetria, ataxia, broad-based members, muscle tremors, loss of tongue tone, frequent falls and death. Grossly hematomas were observed secondary to trauma caused by dominant males of the flock, and whitish striations, especially in the renal cortex. Histologic changes included marked swelling/cytoplasmic vacuolization especially in neurons, progressing to neuronal lysis and axonal spheroids, in exocrine pancreas, thyroid follicular cells and renal tubular epithelial cells. In the lectin-histochemical examination the vacuoles were formed by the accumulation of oligosaccharides specially marked by the lectins WGA, WGA and Con-A. Ultrastructurally, the swelling/vacuolation corresponded to intense cytoplasmic distention of lysosomes, formation of residual bodies or dense granular fragments of membranes and mielinoides bodies. The study has shown the susceptibility of Cervus unicolor to swainsonine by ingestion of S. carpinifolia. Possibly poisoning the animals in this study was conducted by food restriction by the hierarchy among males in the group. It might also determine the marked similarity between clinical and pathological aspects in Sambar deer with the one presented by other herbivores. / Casos de doen?as induzidas por plantas t?xicas em herb?voros dom?sticos s?o bastante relatados por todo o mundo e v?m sendo estudados tamb?m no Brasil. Pouco se sabe, contudo, sobre os aspectos epidemiol?gicos e patol?gicos dessas condi??es em animais selvagens de vida livre ou criados em cativeiro. Os riscos de desenvolvimento dessas toxicoses em cativeiros v?m aumentando, conforme os habitats naturais s?o destru?dos pela a??o humana, e mais centros de conserva??o de vida silvestre e zool?gicos s?o criados. Nesse estudo s?o descritos os aspectos epidemiol?gicos, biol?gicos e clinicopatol?gicos, lectinohistoqu?micos e ultraestruturais de um surto de doen?a do armazenamento lisossomal de oligossacar?deos induzido pela ingest?o de Sida carpinifolia em cervos Sambar jovens (Cervus unicolor) no zool?gico da Funda??o Rio-Zoo no Estado do Rio de Janeiro. Nove cervos apresentaram sinais cl?nicos neurol?gicos caracterizados por d?ficits proprioceptivo e motor. Os sinais neurol?gicos inclu?ram principalmente depress?o, incoordena??o, dismetria, ataxia, membros em base ampla, tremores musculares, perda do t?nus lingual, quedas frequentes e morte. Macroscopicamente foram observados hematomas, secund?rios a traumas provocados por machos dominantes do rebanho, e estria??es esbranqui?adas, principalmente no c?rtex renal. As les?es histol?gicas inclu?am acentuada tumefa??o/vacuoliza??o citoplasm?tica especialmente em neur?nios, p?ncreas ex?crino, c?lulas foliculares da tireoides e do epit?lio renal, necrose neuronal com evolu??o para lise e esferoides axonais. Pelo exame lectino-histoqu?mico os vac?olos eram formados por ac?mulo de oligossacar?deos marcado especialmente pelas lectinas S-WGA, WGA e Con-A. Ultraestruturalmente, a tumefa??o/vacuoliza??o citoplasm?tica correspondeu ? intensa distens?o de lisossomos, forma??o de corpos residuais densos ou granulares, fragmentos de membranas e corpos mielinoides. O estudo demonstrou a suscetibilidade de Cervus unicolor ? swainsonina contida na S. carpinifolia. Possivelmente, a intoxica??o nos animais deste estudo ocorreu pela restri??o alimentar sofrida pelos animais mais jovens, decorrente da hierarquia entre machos no grupo. P?de-se determinar ainda a marcada similaridade do quadro cl?nico e patol?gico entre os cervos descritos nesse trabalho e outros herb?voros dom?sticos.

No description available.

Mucopolysaccharidosis type III (Sanfilippo) is comprised of four phenotypically similar lysosomal storage disorders (MPS IIIA-D) caused by the deficiency of enzymes that catabolise heparan sulphate (HS). Progressive accumulation of HS results in abnormal behaviour, progressive cognitive and motor impairment and death in mid-teens. There are currently no treatments for MPS III. To assess the effect of novel therapeutics in the mouse models of MPS III it is necessary to examine the effect on primary storage of HS, secondary storage and behaviour. The reported behaviour of MPS IIIA and B mice is conflicting therefore we developed a one-hour open field test, performed at the same time of day during a period of hyperactivity observed in a previous circadian rhythm study of MPS IIIB mice. At 8 months of age MPS IIIB mice were hyperactive, with increased rapid exploratory behaviour and a reduction in immobility time. The MPS IIIA mice presented with the same behavioural phenotype as the MPS IIIB mice and were significantly hyperactive at 4 and 6 months of age and also displayed a reduced sense of danger. The hyperactivity and reduced sense of danger observed in the mice is consistent with the patient phenotype. Whilst haematopoietic stem cell transplant (HSCT) is the standard therapy used to treat the similar HS storage disorder MPS I Hurler, it is ineffectual in MPS IIIA. We hypothesise that HSCT failure in MPS IIIA is due to insufficient enzyme production in the brain by donor-derived microglial cells. By increasing expression of N-sulphoglucosamine sulphohydrolase (SGSH) we may be able to treat MPS IIIA. Therefore we compared the effect of HSCT using normal haematopoietic stem cells (WT-HSCT) to lentiviral overexpression of SGSH in normal cells (LV-WT-HSCT) or MPS IIIA cells (LV-IIIA-HSCT) in MPS IIIA mice, using the behavioural tests developed.SGSH activity in the brain of MPS IIIA recipients was not significantly increased by WT-HSCT, but was significantly increased by LV-IIIA-HSCT and LV-WT-HSCT. HS was significantly reduced by all transplants but the best treatment was LV-WT-HSCT. Neuroinflammation, indicated by the number of microglia in the brain, was significantly reduced by all treatments but remains significantly elevated. GM2 gangliosides were significantly reduced by WT-HSCT and LV-WT-HSCT and were no longer significantly elevated, but LV-IIIA-HSCT had no significant effect. Critically LV-WT-HSCT corrected the behaviour at 4 and 6 months of age whilst the other treatments had no significant effect. LV-WT-HSCT and WT-HSCT reduced GM2 gangliosides and neuroinflammation equally but only LV-WT-HSCT corrected behaviour and primary HS storage, suggesting they are the important factors in MPS IIIA pathology. LV-WT-HSCT corrects the neurological phenotype in MPS IIIA mice and is a clinically viable approach to treat MPS IIIA and other neuropathic lysosomal storage disorders.

Le récepteur du mannose-6-phosphate cation indépendant (RM6P-CI) permet l'endocytose puis le transfert de molécules porteuses du marqueur M6P vers les lysosomes. Pour améliorer à la fois l'affinité pour le RM6P-CI et la stabilité du résidu M6P, nous avons procédé à la synthèse d'analogues isostères stables et fonctionnalisés en position anomère pour permettre un couplage efficace à des molécules d'intérêt thérapeutique. Tout d'abord un couplage à des enzymes recombinantes humaines a été réalisé. Le remodelage de la partie oligosaccharidique de l'enzyme lysosomale GAA, dont la déficience est responsable de la maladie de Pompe, a permis de mettre en évidence que la néoglycoGAA est reconnue efficacement par les RM6P-CI et que son activité enzymatique est totalement conservée. Deuxièmement, le couplage de ces analogues du M6P à des porphyrines en vue de la thérapie photodynamique des cancers est envisagé. Le modèle mis au point en série du mannose a permis de valider notre approche de ligation de saccharides à des photosensibilisateurs par des méthodes évitant après couplage les étapes classiques de déprotection des saccharides. L'étude biologique menée sur les porphyrines glycosylées préparées a démontré leur cytotoxicité photoinduite. / The cation independent mannose-6-phosphate receptor (CI-M6PR) allows the endocytosis and the transfer of molecules bearing the M6P marker to lysosomes. To improve both the affinity for the CI-M6PR and stability of the M6P residue, we carried out the synthesis of isosteric M6P analogues functionalized at the anomeric position to allow efficient coupling to molecules of therapeutic interest. First, the coupling on human recombinant enzymes was performed. The remodelling of the oligosaccharide part of the lysosomal enzyme GAA, whose deficiency is responsible for Pompe disease, helped to highlight the neoglycoGAA is recognized efficiently by CI-M6PR and its enzymatic activity is completely preserved. Second, the coupling of these analogues of M6P to porphyrins for photodynamic therapy of cancer was considered. The model developed in the mannose series has validated our strategy of ligation of saccharides to photosensitizers. The employed methods avoid the conventional steps of deprotection of saccharides after coupling. The biological study with the prepared glycosylporphyrins demonstrated the photoinduced cytotoxicity.

<p><strong>Abstract</strong></p> <p>Sandhoff disease (SD) is a monogenic lysosomal storage disorder caused by a lack of a functional β-subunit of the beta-hexosaminidase A and B enzymes. The clinical phenotype of <em>Hexb</em>^-/-mouse model recapitulates the symptoms and signs of Tay-Sachs and Sandhoff diseases in human. To gain insight into the neuropathology of Sandhoff disease, we defined the role of TNFα in the development and progression of Sandhoff disease pathology in mice, by generating a <em>Hexb^-/-Tnf</em><em>a</em><em>^-/-</em> double knock-out mouse. Behavioural testing and immunostaining data revealed the neurodegenerative role of TNFα in disease pathology. Double knock-out mice showed ameliorated clinical course, with prolonged life span. TNFα-deficient Sandhoff mice also demonstrate decreased levels of astrogliosis, and reduced neuronal cell death. Deletion of <em>Tnfα</em> in Sandhoff mice inhibited JAK2/STAT3 pathway, implicating its role in glia cell activation. This result points to TNFa as a potential therapeutic target to attenuate neuro-pathogenesis.</p> <p>To investigate whether blood-derived or CNS-derived TNFα has the major impact on neurological function, we transplanted <em>Hexb^-/-Tnfα^+/+</em> with bone marrow from either <em>Hexb^-/-Tnfα^-/-</em>or <em>Hexb^-/-Tnf</em><em>a</em><em>^+/+</em> mice donors. Neurological tests shows a significant clinical improvement for Hexb<em>^-/-Tnfα^-/-</em> compared to <em>Hexb^-/-Tnf</em><em>a</em><em>^+/+</em> recipient, regardless the genotype of donor cells. These findings highlight the importance of resident-derived TNFα during the robust neurodegenerative consequences in Sandhoff disease. To understand of the role of microRNAs in Sandhoff pathology, we investigated the miRNA profile in Sandhoff brains. A pattern of dys-regulated microRNAs was evident in Sandhoff CNS. Microarray identified miR-210 and miR-96 dys-regulated pattern in the CNS of Sandhoff mice. Strikingly, neuronal pentraxin, a putative target gene for miR-210, was induced in Sandhoff brains.</p> <p>Taken together, this work establishes the proinflammatory role of TNFα in Sandhoff pathology, leading to massive neuro-apoptosis. Importantly, our studies propose that neuronal pentraxin as a novel target gene for microRNA-210 in Sandhoff brain samples, providing a potential modulator of neurodegeneration.</p> / Doctor of Philosophy (PhD)