7 research outputs found

    Adeno-associated viral vector serotype 9-based gene therapy for Niemann-Pick disease type A

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    Niemann-Pick disease type A (NPD-A) is a lysosomal storage disorder characterized by neurodegeneration and early death. It is caused by loss-of-function mutations in the gene encoding for acid sphingomyelinase (ASM), which hydrolyzes sphingomyelin into ceramide. Here, we evaluated the safety of cerebellomedullary (CM) cistern injection of adeno-associated viral vector serotype 9 encoding human ASM (AAV9-hASM) in nonhuman primates (NHP). We also evaluated its therapeutic benefit in a mouse model of the disease (ASM-KO mice). We found that CM injection in NHP resulted in widespread transgene expression within brain and spinal cord cells without signs of toxicity. CM injection in the ASM-KO mouse model resulted in hASM expression in cerebrospinal fluid and in different brain areas without triggering an inflammatory response. In contrast, direct cerebellar injection of AAV9-hASM triggered immune response. We also identified a minimally effective therapeutic dose for CM injection of AAV9-hASM in mice. Two months after administration, the treatment prevented motor and memory impairment, sphingomyelin (SM) accumulation, lysosomal enlargement, and neuronal death in ASM-KO mice. ASM activity was also detected in plasma from AAV9-hASM CM-injected ASM-KO mice, along with reduced SM amount and decreased inflammation in the liver. Our results support CM injection for future AAV9-based clinical trials in NPD-A as well as other lysosomal storage brain disorders.Nation Foundation and by grants from the Spanish Ministry of Economy and Competitivity (SAF-2014-57539-R and SAF2017-87698-R) to M.D.L. and from NIH-NINDS (R01NS073940) to K.S.B. A.P.-C. was a recipient of the FPU predoctoral fellowship from the Spanish Ministry of Economy and Competitivity and Fundación Ramón Areces to the Centro Biología Molecular Severo Ochoa

    Aproximaciones terapéuticas para tratar la patología cerebral en la enfermedad de Niemann Pick tipo A

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    Tesis Doctoral inédita leída en la Universidad Autónoma de Madrid, Facultad de Ciencias, Departamento de Biología Molecular. Fecha de Lectura: 07-10-2022Esta Tesis tiene embargado el acceso al texto completo hasta el 07-04-2024Niemann Pick tipo A (NPA) es una enfermedad rara de almacenamiento lisosomal (LSD) que produce alteraciones cognitivas, neurodegeneración y muerte temprana. Está causada por mutaciones en el gen SMPD1, que codifica para la esfingomielinasa ácida (ASM). La pérdida de función de esta enzima, encargada de la degradación de esfingomielina (SM), provoca la acumulación de este lípido en distintos compartimentos celulares, incluidos la membrana plasmática y el sistema endolisosomal. La barrera hematoencefálica (BBB) es una estructura presente en los vasos sanguíneos del sistema nervioso que asegura la correcta actividad y protección de las células nerviosas, mediante la regulación del movimiento de iones, moléculas y células al parénquima cerebral, y supone la principal limitación para el tratamiento de enfermedades neurológicas. La terapia de reemplazo enzimático ha sido útil en el tratamiento de los síntomas periféricos en NPA. Sin embargo, la ASM recombinante no es capaz de atravesar la BBB y aún no existe tratamiento eficiente para la patología neurológica. En esta tesis hemos estudiado distintas estrategias terapéuticas que tratan de superar esta barrera, mediante la administración directa en el tejido cerebral, el aprovechamiento de los mecanismos de transporte de la BBB, o el uso de compuestos capaces de atravesarla. Los resultados de esta tesis, obtenidos en el modelo de ratón ASMko, demuestran que la administración en la cisterna magna de un vector adenoasociado que expresa ASM (AAV9-hASM) previene la acumulación de SM, la alteración lisosomal y la neurodegeneración de las células de Purkinje, sin producir neuroinflamación, y promueve un aumento de la esperanza de vida. Sin embargo, la inyección intravenosa de conjugados de ASM con nanopuentes que reconocen el Receptor de Transferrina en la BBB, reduce los niveles de SM hepáticos, pero no tiene efectos significativos en el sistema nervioso. Por otra parte, el ensayo tanto in vitro como in vivo de polifenoles capaces de atravesar la BBB, como las urolitinas o el ácido elágico, ha demostrado efectos positivos en la acumulación lipídica, en la patología lisosomal y en la neuroinflamación en modelos celulares y animales para NPA y para otra LSD como Niemann Pick tipo C (NPC), probablemente gracias al aumento en la secreción de vesículas extracelulares. Consideramos que estos resultados abren nuevas perspectivas terapéuticas para NPA, y permiten proponer la combinación de terapias como una solución ante la ausencia actual de tratamientos. Además, los resultados positivos observados también en modelos para NPC, apoyan el uso de ciertas estrategias en otras LSDs caracterizadas por la acumulación lipídic

    NPC1 enables cholesterol mobilization during long‐term potentiation that can be restored in Niemann–Pick disease type C by CYP46A1 activation

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    NPC is a neurodegenerative disorder characterized by cholesterol accumulation in endolysosomal compartments. It is caused by mutations in the gene encoding NPC1, an endolysosomal protein mediating intracellular cholesterol trafficking. Cognitive and psychiatric alterations are hallmarks in NPC patients pointing to synaptic defects. However, the role of NPC1 in synapses has not been explored. We show that NPC1 is present in the postsynaptic compartment and is locally translated during LTP. A mutation in a region of the NPC1 gene commonly altered in NPC patients reduces NPC1 levels at synapses due to enhanced NPC1 protein degradation. This leads to shorter postsynaptic densities, increased synaptic cholesterol and impaired LTP in NPC1nmf164 mice with cognitive deficits. NPC1 mediates cholesterol mobilization and enables surface delivery of CYP46A1 and GluA1 receptors necessary for LTP, which is defective in NPC1nmf164 mice. Pharmacological activation of CYP46A1 normalizes synaptic levels of cholesterol, LTP and cognitive abilities, and extends life span of NPC1nmf164 mice. Our results unveil NPC1 as a regulator of cholesterol dynamics in synapses contributing to synaptic plasticity, and provide a potential therapeutic strategy for NPC patients

    Ellagic acid and its metabolites urolithins A/B ameliorate most common disease phenotypes in cellular and mouse models for lysosomal storage disorders by enhancing extracellular vesicle secretion

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    Niemann Pick diseases types A (NPDA) and C (NPDC) are lysosomal storage disorders (LSDs) leading to cognitive impairment, neurodegeneration, and early death. NPDA and NPDC have different genetic origins, being caused by mutations in the acid sphingomyelinase (ASM) or the cholesterol transport protein NPC1, respectively. However, they share a common pathological hallmark in the accumulation of lipids in the endolysosomal compartment. Here, we tested the hypothesis that polyphenols reduce lipid overload in NPD cells by enhancing the secretion of extracellular vesicles (ECVs). We show that among the polyphenols tested, the ellagic acid metabolites, urolithin A and B, were the safest and most efficient in increasing ECV secretion. They reduced levels of accumulating lipids and lysosomal size and permeabilization in cultured bone marrow-derived macrophages and neurons from ASMko and NPC1 mutant mice, which mimic NPDA and NPDC, respectively. Moreover, oral treatment with ellagic acid reduced lipid levels, ameliorated lysosomal alterations, and diminished microglia activation in the brain of NPD mice. These results support the therapeutic value of ECV secretion and polyphenols for NPDs, which may also help treat other LSDs characterized by intracellular lipid overload
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