scholarly journals MCOLN1 gene-replacement therapy corrects neurologic dysfunction in the mouse model of mucolipidosis IV

2020 ◽  
Author(s):  
Samantha DeRosa ◽  
Monica Salani ◽  
Sierra Smith ◽  
Madison Sangster ◽  
Victoria Miller-Browne ◽  
...  
Keyword(s):  
Gene Transfer ◽  
Mouse Model ◽  
Motor Function ◽  
Transient Receptor Potential ◽  
Vision Loss ◽  
Unmet Need ◽  
Gene Replacement ◽  
Lysosomal Storage ◽  
Loss Of Function ◽  
Mucolipidosis Iv

AbstractMucolipidosis IV (MLIV, OMIM 252650) is an orphan disease leading to debilitating psychomotor deficits and vision loss. It is caused by loss-of-function mutations in the MCOLN1 gene that encodes thethe lysosomal transient receptor potential channel mucolipin 1 (TRPML1). With no existing therapy, the unmet need in this disease is very high. Here we show that AAV-mediated gene transfer of the human MCOLN1 gene rescues motor function and alleviates brain pathology in the Mcoln1−/− MLIV mouse model. Using the AAV-PHP.b vector for initial proof-of-principle experiments in symptomatic mice, we showed long-term reversal of declined motor function and significant delay of paralysis. Next, we designed self-complimentary AAV9 vector for clinical use and showed that its intracerebroventricular administration in post-natal day 1 mice significantly improved motor function and myelination and reduced lysosomal storage load in the MLIV mouse brain. We also showed that CNS targeted gene transfer is necessary to achieve therapeutic efficacy in this disease. Based on our data and general advancements in the gene therapy field, we propose scAAV9-mediated CSF-targeted MCOLN1 gene transfer as a therapeutic strategy in MLIV.

scholarly journals Peripheral Inflammatory Cytokine Signature Mirrors Motor Deficits in Mucolipidosis IV

2021 ◽  
Author(s):  
Albert Misko ◽  
Laura D Weinstock ◽  
Sitara B Sankar ◽  
Amanda Furness ◽  
Yulia Grishchuk ◽  
...  
Keyword(s):  
Motor Function ◽  
Transient Receptor Potential ◽  
Receptor Potential ◽  
Motor Dysfunction ◽  
Motor Deficits ◽  
Loss Of Function ◽  
Brief Assessment ◽  
Blood Cytokines ◽  
Mucolipidosis Iv ◽  
Transient Receptor

Mucolipidosis IV (MLIV) is an autosomal-recessive pediatric disease that leads to motor and cognitive deficits and loss of vision. It is caused by loss-of-function of the lysosomal channel transient receptor potential mucolipin-1 and is associated with an early pro-inflammatory brain phenotype, including increased cytokine expression. We thus hypothesized that peripheral blood cytokines would reflect inflammatory changes in the brain and would be linked to motor dysfunction. To test this, we collected plasma from MLIV patients and parental controls concomitantly with assessment of motor function using the Brief Assessment of Motor Function and Modified Ashworth scores. We found that MLIV patients had prominently increased cytokine levels compared to familial controls and identified profiles of cytokines correlated with motor dysfunction, including IFN-γ, IFN-α2, IL-17, IP-10. We found that IP-10 was a key differentiating factor separating MLIV cases from controls based on data from human plasma, mouse plasma, and mouse brain. Like MLIV patients, IL-17 and IP-10 were up-regulated in blood of symptomatic mice. Together, our data indicate that MLIV is characterized by increased blood cytokines, which are strongly related to underlying neurological and functional deficits in MLIV patients. Moreover, our data identify the interferon pro-inflammatory axis in both human and mouse signatures, suggesting an importance for interferon signaling in MLIV.

scholarly journals Mutation of SLC7A14 Causes Auditory Neuropathy and Retinitis Pigmentosa Mediated by Lysosomal Dysfunction

2021 ◽  
Author(s):  
Kimberlee P Giffen ◽  
Yi Li ◽  
Huizhan Liu ◽  
Xiao-Chang Zhao ◽  
Chang-Jun Zhang ◽  
...  
Keyword(s):  
Retinitis Pigmentosa ◽  
Hair Cells ◽  
Vision Loss ◽  
Nutrient Sensing ◽  
Auditory Neuropathy ◽  
Recessive Mutation ◽  
Lysosomal Storage ◽  
Loss Of Function ◽  
Cell Degeneration ◽  
Lysosomal Dysfunction

Lysosomes contribute to cellular homeostasis via processes including phagocytosis, macromolecule catabolism, secretion, and nutrient sensing mechanisms. Defective proteins related to lysosomal macromolecule catabolism are known to cause a broad range of lysosomal storage diseases. It is unclear, however, if mutations in genes in the autophagy-lysosomal pathway can cause syndromic disease. Here we show that SLC7A14, a transporter protein mediating lysosomal uptake of cationic amino acids, is evolutionarily conserved in vertebrate mechanosensitive hair cells and highly expressed in lysosomes of mammalian cochlear inner hair cells (IHCs) and retinal photoreceptors. Autosomal recessive mutation of SLC7A14 caused loss of IHCs and photoreceptors, leading to pre-synaptic auditory neuropathy and retinitis pigmentosa in mice and humans. Loss of function mutation altered protein trafficking and disrupted lysosomal homeostasis, resulting in dysregulation of basal autophagy and progressive cell degeneration. This study is the first to implicate autophagy-lysosomal dysfunction in syndromic hearing and vision loss in mice and humans. 

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

2019 ◽  
Vol 11 (506) ◽  
pp. eaat3738 ◽  
Author(s):  
Lluis Samaranch ◽  
Azucena Pérez-Cañamás ◽  
Beatriz Soto-Huelin ◽  
Vivek Sudhakar ◽  
Jerónimo Jurado-Arjona ◽  
...  
Keyword(s):  
Mouse Model ◽  
Viral Vector ◽  
Type A ◽  
Disease Type ◽  
Acid Sphingomyelinase ◽  
Lysosomal Storage ◽  
Loss Of Function ◽  
Niemann Pick Disease ◽  
Niemann Pick ◽  
Pick Disease

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.

scholarly journals Fingolimod phosphate inhibits astrocyte inflammatory activity in mucolipidosis IV

2018 ◽  
Vol 27 (15) ◽  
pp. 2725-2738 ◽  
Author(s):  
Laura D Weinstock ◽  
Amanda M Furness ◽  
Shawn S Herron ◽  
Sierra S Smith ◽  
Sitara B Sankar ◽  
...  
Keyword(s):  
Mouse Model ◽  
Protein Signaling ◽  
Loss Of Function ◽  
Neurodevelopmental Disease ◽  
Mapk Pathways ◽  
Inflammatory Activation ◽  
Mucolipidosis Iv ◽  
Pro Inflammatory Cytokines

Abstract Mucolipidosis IV (MLIV) is an orphan neurodevelopmental disease that causes severe neurologic dysfunction and loss of vision. Currently there is no therapy for MLIV. It is caused by loss of function of the lysosomal channel mucolipin-1, also known as TRPML1. Knockout of the Mcoln1 gene in a mouse model mirrors clinical and neuropathologic signs in humans. Using this model, we previously observed robust activation of microglia and astrocytes in early symptomatic stages of disease. Here we investigate the consequence of mucolipin-1 loss on astrocyte inflammatory activation in vivo and in vitro and apply a pharmacologic approach to restore Mcoln1−/− astrocyte homeostasis using a clinically approved immunomodulator, fingolimod. We found that Mcoln1−/− mice over-express numerous pro-inflammatory cytokines, some of which were also over-expressed in astrocyte cultures. Changes in the cytokine profile in Mcoln1−/− astrocytes are concomitant with changes in phospho-protein signaling, including activation of PI3K/Akt and MAPK pathways. Fingolimod promotes cytokine homeostasis, down-regulates signaling within the PI3K/Akt and MAPK pathways and restores the lysosomal compartment in Mcoln1−/− astrocytes. These data suggest that fingolimod is a promising candidate for preclinical evaluation in our MLIV mouse model, which, in case of success, can be rapidly translated into clinical trial.

scholarly journals Early evidence of delayed oligodendrocyte maturation in the mouse model of mucolipidosis type IV

2020 ◽  
Vol 13 (7) ◽  
pp. dmm044230 ◽  
Author(s):  
Molly Mepyans ◽  
Livia Andrzejczuk ◽  
Jahree Sosa ◽  
Sierra Smith ◽  
Shawn Herron ◽  
...  
Keyword(s):  
Mouse Model ◽  
Transient Receptor Potential ◽  
Vision Loss ◽  
Cerebellar Atrophy ◽  
Receptor Potential ◽  
Transient Receptor Potential Channel ◽  
Lysosomal Disease ◽  
Mucolipidosis Type Iv ◽  
Type Iv ◽  
Mucolipidosis Type

ABSTRACTMucolipidosis type IV (MLIV) is a lysosomal disease caused by mutations in the MCOLN1 gene that encodes the endolysosomal transient receptor potential channel mucolipin-1, or TRPML1. MLIV results in developmental delay, motor and cognitive impairments, and vision loss. Brain abnormalities include thinning and malformation of the corpus callosum, white-matter abnormalities, accumulation of undegraded intracellular ‘storage’ material and cerebellar atrophy in older patients. Identification of the early events in the MLIV course is key to understanding the disease and deploying therapies. The Mcoln1−/− mouse model reproduces all major aspects of the human disease. We have previously reported hypomyelination in the MLIV mouse brain. Here, we investigated the onset of hypomyelination and compared oligodendrocyte maturation between the cortex/forebrain and cerebellum. We found significant delays in expression of mature oligodendrocyte markers Mag, Mbp and Mobp in the Mcoln1−/− cortex, manifesting as early as 10 days after birth and persisting later in life. Such delays were less pronounced in the cerebellum. Despite our previous finding of diminished accumulation of the ferritin-bound iron in the Mcoln1−/− brain, we report no significant changes in expression of the cytosolic iron reporters, suggesting that iron-handling deficits in MLIV occur in the lysosomes and do not involve broad iron deficiency. These data demonstrate very early deficits of oligodendrocyte maturation and critical regional differences in myelination between the forebrain and cerebellum in the mouse model of MLIV. Furthermore, they establish quantitative readouts of the MLIV impact on early brain development, useful to gauge efficacy in pre-clinical trials.

scholarly journals Reconstitution of lysosomal NAADP-TRP-ML1 signaling pathway and its function in TRP-ML1−/− cells

2011 ◽  
Vol 301 (2) ◽  
pp. C421-C430 ◽  
Author(s):  
Fan Zhang ◽  
Ming Xu ◽  
Wei-Qing Han ◽  
Pin-Lan Li
Keyword(s):  
Transient Receptor Potential ◽  
Human Fibroblasts ◽  
Receptor Potential ◽  
Channel Activity ◽  
Lysosomal Storage ◽  
Release Channel ◽  
Lipid Trafficking ◽  
Intracellular Ca ◽  
Mucolipidosis Iv ◽  
Transient Receptor

It is well known that the mutation of TRP-ML1 (transient receptor potential-mucolipin-1) causes mucolipidosis IV, a lysosomal storage disease. Given that lysosomal nicotinic acid adenine dinucleotide phosphate (NAADP)-Ca2+ release channel activity is associated with TRP-ML1, the present study was designed to test the hypothesis that NAADP regulates lysosome function via activation of TRP-ML1 channel activity. Using lysosomal preparations from wild-type (TRP-ML1+/+) human fibroblasts, channel reconstitution experiments demonstrated that NAADP (0.01–1.0 μM) produced a concentration-dependent increase in TRP-ML1 channel activity. This NAADP-induced activation of TRP-ML1 channels could not be observed in lysosomes from TRP-ML1−/− cells, but was restored by introducing a TRP-ML1 transgene into these cells. Microscopic Ca2+ fluorescence imaging showed that NAADP significantly increased intracellular Ca2+ concentration to 302.4 ± 74.28 nM (vs. 180 ± 44.13 nM of the basal) in TRP-ML1+/+ cells, but it had no effect in TRP-ML1−/− cells. If a TRP-ML1 gene was transfected into TRP-ML1−/− cells, the Ca2+ response to NAADP was restored to the level comparable to TRP-ML1+/+ cells. Functionally, confocal microscopy revealed that NAADP significantly enhanced the dynamic interaction of endosomes and lysosomes and the lipid delivery to lysosomes in TRP-ML1+/+ cells. This functional action of NAADP was abolished in TRP-ML1−/− cells, but restored after TRP-ML1 gene was rescued in these cells. Our results suggest that NAADP increases lysosomal TRP-ML1 channel activity to release Ca2+, which promotes the interaction of endosomes and lysosomes and thereby regulates lipid transport to lysosomes. Failure of NAADP-TRP-ML1 signaling may be one of the important mechanisms resulting in intracellular lipid trafficking disorder and consequent mucolipidosis.

scholarly journals A Mild Phenotype Caused by Two Novel Compound Heterozygous Mutations in CEP290

Genes ◽  
2020 ◽  
Vol 11 (11) ◽  
pp. 1240
Author(s):  
Agnieszka Rafalska ◽  
Anna M. Tracewska ◽  
Anna Turno-Kręcicka ◽  
Milena J. Szafraniec ◽  
Marta Misiuk-Hojło
Keyword(s):  
Vision Loss ◽  
Compound Heterozygous ◽  
Loss Of Function ◽  
Mild Phenotype ◽  
Cone Function ◽  
Retinal Disorders ◽  
Molecular Inversion Probes ◽  
Disease Experience ◽  
The Individual ◽  
Inherited Retinal Disorders

CEP290 is a ciliary gene frequently mutated in ciliopathies, resulting in a broad range of phenotypes, ranging from isolated inherited retinal disorders (IRDs) to severe or lethal syndromes with multisystemic involvement. Patients with non-syndromic CEP290-linked disease experience profound and early vision loss due to cone-rod dystrophy, as in Leber congenital amaurosis. In this case report, we describe two novel loss-of-function heterozygous alterations in the CEP290 gene, discovered in a patient suffering from retinitis pigmentosa using massive parallel sequencing of a molecular inversion probes library constructed for 108 genes involved in IRDs. A milder phenotype than expected was found in the individual, which serves to prove that some CEP290-associated disorders may display preserved cone function.

scholarly journals Identification of a novel homozygous loss-of-function mutation in FUCA1 gene causing severe fucosidosis: A case report

2021 ◽  
Vol 49 (4) ◽  
pp. 030006052110059
Author(s):  
Xinwen Zhang ◽  
Shaozhi Zhao ◽  
Hongwei Liu ◽  
Xiaoyan Wang ◽  
Xiaolei Wang ◽  
...  
Keyword(s):  
Amino Acids ◽  
Lysosomal Storage Disorder ◽  
Autosomal Recessive ◽  
Signs And Symptoms ◽  
Lysosomal Storage ◽  
Loss Of Function ◽  
Wild Type ◽  
Single Nucleotide ◽  
Whole Exome ◽  
Exon 1

Fucosidosis is a rare lysosomal storage disorder characterized by deficiency of α-L-fucosidase with an autosomal recessive mode of inheritance. Here, we describe a 4-year-old Chinese boy with signs and symptoms of fucosidosis but his parents were phenotypically normal. Whole exome sequencing (WES) identified a novel homozygous single nucleotide deletion (c.82delG) in the exon 1 of the FUCA1 gene. This mutation will lead to a frameshift which will result in the formation of a truncated FUCA1 protein (p.Val28Cysfs*105) of 132 amino acids approximately one-third the size of the wild type FUCA1 protein (466 amino acids). Both parents were carrying the mutation in a heterozygous state. This study expands the mutational spectrum of the FUCA1 gene associated with fucosidosis and emphasises the benefits of WES for accurate and timely clinical diagnosis of this rare disease.

scholarly journals Beneficial Effects of Acetyl-DL-Leucine (ADLL) in a Mouse Model of Sandhoff Disease

2020 ◽  
Vol 9 (4) ◽  
pp. 1050 ◽  
Author(s):  
Ecem Kaya ◽  
David A. Smith ◽  
Claire Smith ◽  
Barry Boland ◽  
Michael Strupp ◽  
...  
Keyword(s):  
Mouse Model ◽  
Sandhoff Disease ◽  
Lysosomal Storage ◽  
Gm2 Ganglioside ◽  
Beneficial Effects ◽  
New Therapeutic Approaches ◽  
Late Endosomes ◽  
Altered Glucose ◽  
Cerebellar Ataxias ◽  
Niemann Pick

Sandhoff disease is a rare neurodegenerative lysosomal storage disease associated with the storage of GM2 ganglioside in late endosomes/lysosomes. Here, we explored the efficacy of acetyl-DL-leucine (ADLL), which has been shown to improve ataxia in observational studies in patients with Niemann–Pick Type C1 and other cerebellar ataxias. We treated a mouse model of Sandhoff disease (Hexb-/-) (0.1 g/kg/day) from 3 weeks of age with this orally available drug. ADLL produced a modest but significant increase in life span, accompanied by improved motor function and reduced glycosphingolipid (GSL) storage in the forebrain and cerebellum, in particular GA2. ADLL was also found to normalize altered glucose and glutamate metabolism, as well as increasing autophagy and the reactive oxygen species (ROS) scavenger, superoxide dismutase (SOD1). Our findings provide new insights into metabolic abnormalities in Sandhoff disease, which could be targeted with new therapeutic approaches, including ADLL.

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