Intracerebroventricular 2-hydroxypropyl-γ-cyclodextrin alleviates hepatic manifestations without distributing to the liver in a murine model of Niemann-pick disease type C.

Niemann-Pick disease type C (NPC) is a lysosomal lipid storage disorder characterized by progressive neurodegeneration and hepatic dysfunction. A cyclic heptasaccharide, 2-hydroxypropyl-ß-cyclodextrin (HP-ß-CD), is currently under clinical investigation for NPC, but its adverse events remain problematic. We previously identified that a cyclic octasaccharide, 2-hydroxypropyl-γ-cyclodextrin (HP-γ-CD), also ameliorated NPC manifestations with higher biocompatibility than HP-ß-CD. However, preclinical studies describing the associations between the biodistribution and pharmacodynamics of these compounds, which are essential for clinical application, are still lacking. Here, we investigated these properties of HP-γ-CD by measuring its organ biodistribution and therapeutic effect after systemic and central administration. The effect of HP-γ-CD on disturbed cholesterol homeostasis appeared within several hours after exposure and persisted for several days in NPC model cells and mice. Tissue distribution indicated that only a small fraction of subcutaneously administered HP-γ-CD rapidly distributed to peripheral organs and contributed to disease amelioration. We found that a subcutaneous dose of HP-γ-CD negligibly ameliorated neurological characteristics because it has limited penetration of the blood-brain barrier; however, an intracerebroventricular microdose unexpectedly attenuated hepatic dysfunction without the detection of HP-γ-CD in the liver. These results demonstrate that central administration of HP-γ-CD can indirectly attenuate peripheral manifestations of NPC.

Upregulation of NPC1 and its association with poor prognosis in gastric cancer.

BACKGROUND: The Niemann-Pick disease type C1 (NPC1) protein plays a pivotal role in lipid transport, particularly free cholesterol, within lysosomal/late endosomal membranes. Previous studies have highlighted NPC1 as a promising target for cholesterol trafficking and cancer therapy. Nevertheless, the expression of NPC1 in gastric cancer (GC) and its clinical implications remain unexplored. This study aims to investigate NPC1 expression in GC and its correlation with patient prognosis. METHODS: NPC1 expression levels in GC and normal tissues were assessed using the GEPIA database, and survival analysis was conducted via Kaplan‒Meier Plotter. Evaluation of potential biological effects of NPC1 in GC by protein-protein interaction network and GO, KEGG bioenrichment analysis. Immunohistochemistry was performed on surgical samples collected from 306 GC patients. Correlations between NPC1 expression, clinical characteristics, and patient prognosis were analyzed. RESULTS: NPC1 mRNA expression was elevated in GC tissues compared to normal tissues (P < 0.05) and significantly associated with poorer prognosis. In our cohort of 306 patients, NPC1 exhibited significant upregulation in GC versus adjacent normal tissues (P = 0.031). High NPC1 expression correlated with adverse clinical characteristics, including lymph node metastasis, distant metastasis, and advanced TNM stage (all P < 0.05). Patients with high NPC1 expression experienced notably shorter overall survival (P < 0.001), particularly in stages III and IV (P = 0.003). Multivariate Cox regression analysis identified high NPC1 expression as an independent prognostic factor for GC patients (HR 1.57, 95% CI 1.14-2.18, P = 0.006). Lastly, an optimized nomogram incorporating NPC1, tumor size, and TNM stage was constructed. CONCLUSIONS: NPC1 expression is upregulated in GC and serves as a pivotal prognostic factor for adverse outcomes in GC patients.

Spatial neurolipidomics-MALDI mass spectrometry imaging of lipids in brain pathologies.

Given the complexity of nervous tissues, understanding neurochemical pathophysiology puts high demands on bioanalytical techniques with respect to specificity and sensitivity. Mass spectrometry imaging (MSI) has evolved to become an important, biochemical imaging technology for spatial biology in biological and translational research. The technique facilitates comprehensive, sensitive elucidation of the spatial distribution patterns of drugs, lipids, peptides, and small proteins in situ. Matrix-assisted laser desorption ionization (MALDI)-based MSI is the dominating modality due to its broad applicability and fair compromise of selectivity, sensitivity price, throughput, and ease of use. This is particularly relevant for the analysis of spatial lipid patterns, where no other comparable spatial profiling tools are available. Understanding spatial lipid biology in nervous tissue is therefore a key and emerging application area of MSI research. The aim of this review is to give a concise guide through the MSI workflow for lipid imaging in central nervous system (CNS) tissues and essential parameters to consider while developing and optimizing MSI assays. Further, this review provides a broad overview of key developments and applications of MALDI MSI-based spatial neurolipidomics to map lipid dynamics in neuronal structures, ultimately contributing to a better understanding of neurodegenerative disease pathology.

Long-term efficacy of intrathecal cyclodextrin in patients with Niemann-Pick disease type C.

BACKGROUND AND OBJECTIVES: Niemann-Pick type C (NPC) is a rare lysosomal storage disease characterized by hepatosplenomegaly and progressive neurological deterioration due to abnormal intracellular cholesterol transport. Cyclic oligosaccharide 2-hydroxypropyl-ß-cyclodextrin (HPBCD) is an effective treatment for NPC; however, few reports have shown its long-term efficacy and safety. To demonstrate long-term efficacy and safety of intrathecal HPBCD (IT-HPBCD) treatment for NPC, we herein reports five patients with NPC treated using IT-HPBCD for 4-11 years. CASES AND RESULTS: Patients' ages at the onset ranged from 1.5 to 20 years. Notably, all patients showed rapid disease progression despite treatment with miglustat before IT-HPBCD treatment. Similarly, some patients showed transient improvement; however, all patients' conditions stabilized after long-term IT-HPBCD therapy. Mild-to-moderate hearing loss was observed in three patients. Furthermore, long-term treatment with IT-HPBCD may suppress neurological deterioration in patients with NPC; however, patients still experience some disease progression. CONCLUSIONS: Long-term treatment with IT-HPBCD may suppress neurological deterioration in patients with NPC; however, the treatment outcome is dependent on the neurological status at the time of diagnosis, and disease progression is not completely inhibited. Awareness of the disease and newborn screening is needed for earlier disease detection. In addition, further optimization of the treatment protocol and additional treatments are needed to improve patient outcomes.

Differential Interferon Signaling Regulation and Oxidative Stress Responses in the Cerebral Cortex and Cerebellum Could Account for the Spatiotemporal Pattern of Neurodegeneration in Niemann-Pick Disease Type C.

Niemann-Pick disease type C (NPC) is a fatal neurodegenerative condition caused by genetic mutations of the NPC1 or NPC2 genes that encode the NPC1 and NPC2 proteins, respectively, which are believed to be responsible for cholesterol efflux from late-endosomes/lysosomes. The pathogenic mechanisms that lead to neurodegeneration in NPC are not well understood. There are, however, well-defined spatiotemporal patterns of neurodegeneration that may provide insight into the pathogenic process. For example, the cerebellum is severely affected from early disease stages, compared with cerebral regions, which remain relatively spared until later stages. Using a genome-wide transcriptome analysis, we have recently identified an aberrant pattern of interferon activation in the cerebella of pre-symptomatic Npc1-/- mice. Here, we carried out a comparative transcriptomic analysis of cerebral cortices and cerebella of pre-symptomatic Npc1-/- mice and age-matched controls to identify differences that may help explain the pathological progression within the NPC brain. We report lower cerebral expression of genes within interferon signaling pathways, and significant differences in the regulation of oxidative stress, compared with the cerebellum. Our findings suggest that a delayed onset of interferon signaling, possibly linked to lower oxidative stress, may account for the slower onset of cerebral cortical pathology in the disease.

Npc1 gene mutation abnormally activates the classical Wnt signalling pathway in mouse kidneys and promotes renal fibrosis.

Niemann-Pick disease type C1 (NPC1) is a lysosomal lipid storage disease caused by NPC1 gene mutation. Our previous study found that, compared with wild-type (Npc1+/+ ) mice, the renal volume and weight of Npc1 gene mutant (Npc1-/- ) mice were significantly reduced. We speculate that Npc1 gene mutations may affect the basic structure of the kidneys of Npc1-/- mice, and thus affect their function. Therefore, we randomly selected postnatal Day 28 (P28) and P56 Npc1+/+ and Npc1-/- mice, and observed the renal structure and pathological changes by haematoxylin-eosin staining. The level of renal fibrosis was detected by immunofluorescence histochemical techniques, and western blotting was used to detect the expression levels of apoptosis-related proteins and canonical Wnt signalling pathway related proteins. The results showed that compared with Npc1+/+ mice, the kidneys of P28 and P56 Npc1-/- mice underwent apoptosis and fibrosis; furthermore, there were obvious vacuoles in the cytoplasm of renal tubular epithelial cells of P56 Npc1-/- mice, the cell bodies were loose and foam-like, and the canonical Wnt signalling pathway was abnormally activated. These results showed that Npc1 gene mutation can cause pathological changes in the kidneys of mice. As age increased, vacuoles developed in the cytoplasm of renal tubular epithelial cells, and apoptosis of renal cells, abnormal activation of the Wnt signalling pathway, and promotion of renal fibrosis increased.

Development and validation of a new genotype-phenotype correlation for Niemann-Pick disease type C1.

Hundreds of NPC1 variants cause highly heterogeneous phenotypes. This study aims to explore the genotype-phenotype correlation of NPC1, especially for missense variants. In a well-characterized cohort, phenotypes are graded into three clinical forms: mild, intermediate, and severe. Missense residue structural location was stratified into three categories: surface, partially, and fully buried. The association of phenotypes with the topography of the amino acid substitution in the protein structure was investigated in our cohort and validated in two reported cohorts. One hundred six unrelated NPC1 patients were enrolled. A significant correlation of genotype-phenotype was found in 81 classified individuals with two or one (the second was null variant) missense variant (p < 0.001): of 25 patients with at least one missense variant of surface (group A), 19 (76%) mild, six (24%) intermediate, and none severe; of 31 cases with at least one missense variant of partially buried without surface variants (group B), 11 (35%) mild, 16 (52%) intermediate, and four (13%) severe; of the remaining 25 patients with two or one buried missense variants (group C), eight (32%) mild, nine (36%) intermediate, and eight (32%) severe. Additionally, 7-ketocholesterol, the biomarker, was lower in group A than in group B (p = 0.024) and group C (p = 0.029). A model was proposed that accurately predicted phenotypes of 72 of 90 (80%), 73 of85 (86%), and 64 of 69 (93%) patients in our cohort, Italian, and UK cohort, respectively. This study proposed a novel genotype-phenotype correlation in NPC1, linking the underlying molecular pathophysiology with clinical phenotype and aiding genetic counseling and evaluation in clinical practice.

Niemann-Pick Disease Type C (NPDC) by Mutation of NPC1 and NPC2: Aberrant Lysosomal Cholesterol Trafficking and Oxidative Stress.

Cholesterol trafficking is initiated by the endocytic pathway and transported from endo/lysosomes to other intracellular organelles. Deficiencies in cholesterol-sensing and binding proteins NPC1 and NPC2 induce accumulation in lysosomes and the malfunction of trafficking to other organelles. Each organelle possesses regulatory factors to induce cholesterol trafficking. The mutation of NPC1 and NPC2 genes induces Niemann-Pick disease type C (NPDC), which is a hereditary disease and causes progressive neurodegeneration, developmental disability, hypotonia, and ataxia. Oxidative stress induces damage in NPDC-related intracellular organelles. Although studies on the relationship between NPDC and oxidation are relatively rare, several studies have reported the therapeutic potential of antioxidants in treating NPDC. Investigating antioxidant drugs to relieve oxidative stress and cholesterol accumulation is suggested to be a powerful tool for developing treatments for NPDC. Understanding NPDC provides challenging issues in understanding the oxidative stress-lysosome metabolism of the lipid axis. Thus, we elucidated the relationship between complexes of intracellular organelles and NPDC to develop our knowledge and suggested potential antioxidant reagents for NPDC therapy.

Global Proteomics for Identifying the Alteration Pathway of Niemann-Pick Disease Type C Using Hepatic Cell Models.

Niemann-Pick disease type C (NPC) is an autosomal recessive disorder with progressive neurodegeneration. Although the causative genes were previously identified, NPC has unclear pathophysiological aspects, and patients with NPC present various symptoms and onset ages. However, various novel biomarkers and metabolic alterations have been investigated; at present, few comprehensive proteomic alterations have been reported in relation to NPC. In this study, we aimed to elucidate proteomic alterations in NPC and perform a global proteomics analysis for NPC model cells. First, we developed two NPC cell models by knocking out NPC1 using CRISPR/Cas9 (KO1 and KO2). Second, we performed a label-free (LF) global proteomics analysis. Using the LF approach, more than 300 proteins, defined as differentially expressed proteins (DEPs), changed in the KO1 and/or KO2 cells, while the two models shared 35 DEPs. As a bioinformatics analysis, the construction of a protein-protein interaction (PPI) network and an enrichment analysis showed that common characteristic pathways such as ferroptosis and mitophagy were identified in the two model cells. There are few reports of the involvement of NPC in ferroptosis, and this study presents ferroptosis as an altered pathway in NPC. On the other hand, many other pathways and DEPs were previously suggested to be associated with NPC, supporting the link between the proteome analyzed here and NPC. Therapeutic research based on these results is expected in the future.

Kinetic modelling of sterol transport between plasma membrane and endo-lysosomes based on quantitative fluorescence and X-ray imaging data.

Niemann Pick type C1 and C2 (NPC1 and NPC2) are two sterol-binding proteins which, together, orchestrate cholesterol transport through late endosomes and lysosomes (LE/LYSs). NPC2 can facilitate sterol exchange between model membranes severalfold, but how this is connected to its function in cells is poorly understood. Using fluorescent analogs of cholesterol and quantitative fluorescence microscopy, we have recently measured the transport kinetics of sterol between plasma membrane (PM), recycling endosomes (REs) and LE/LYSs in control and NPC2 deficient fibroblasts. Here, we use kinetic modeling of this data to determine rate constants for sterol transport between intracellular compartments. Our model predicts that sterol is trapped in intraluminal vesicles (ILVs) of LE/LYSs in the absence of NPC2, causing delayed sterol export from LE/LYSs in NPC2 deficient fibroblasts. Using soft X-ray tomography, we confirm, that LE/LYSs of NPC2 deficient cells but not of control cells contain enlarged, carbon-rich intraluminal vesicular structures, supporting our model prediction of lipid accumulation in ILVs. By including sterol export via exocytosis of ILVs as exosomes and by release of vesicles-ectosomes-from the PM, we can reconcile measured sterol efflux kinetics and show that both pathways can be reciprocally regulated by the intraluminal sterol transfer activity of NPC2 inside LE/LYSs. Our results thereby connect the in vitro function of NPC2 as sterol transfer protein between membranes with its in vivo function.

Urinary Metabolic Distinction of Niemann-Pick Class 1 Disease through the Use of Subgroup Discovery.

In this investigation, we outline the applications of a data mining technique known as Subgroup Discovery (SD) to the analysis of a sample size-limited metabolomics-based dataset. The SD technique utilized a supervised learning strategy, which lies midway between classificational and descriptive criteria, in which given the descriptive property of a dataset (i.e., the response target variable of interest), the primary objective was to discover subgroups with behaviours that are distinguishable from those of the complete set (albeit with a differential statistical distribution). These approaches have, for the first time, been successfully employed for the analysis of aromatic metabolite patterns within an NMR-based urinary dataset collected from a small cohort of patients with the lysosomal storage disorder Niemann-Pick class 1 (NPC1) disease (n = 12) and utilized to distinguish these from a larger number of heterozygous (parental) control participants. These subgroup discovery strategies discovered two different NPC1 disease-specific metabolically sequential rules which permitted the reliable identification of NPC1 patients; the first of these involved 'normal' (intermediate) urinary concentrations of xanthurenate, 4-aminobenzoate, hippurate and quinaldate, and disease-downregulated levels of nicotinate and trigonelline, whereas the second comprised 'normal' 4-aminobenzoate, indoxyl sulphate, hippurate, 3-methylhistidine and quinaldate concentrations, and again downregulated nicotinate and trigonelline levels. Correspondingly, a series of five subgroup rules were generated for the heterozygous carrier control group, and 'biomarkers' featured in these included low histidine, 1-methylnicotinamide and 4-aminobenzoate concentrations, together with 'normal' levels of hippurate, hypoxanthine, quinolinate and hypoxanthine. These significant disease group-specific rules were consistent with imbalances in the combined tryptophan-nicotinamide, tryptophan, kynurenine and tyrosine metabolic pathways, along with dysregulations in those featuring histidine, 3-methylhistidine and 4-hydroxybenzoate. In principle, the novel subgroup discovery approach employed here should also be readily applicable to solving metabolomics-type problems of this nature which feature rare disease classification groupings with only limited patient participant and sample sizes available.

Long-term administration of intravenous Trappsol® Cyclo™ (HP-ß-CD) results in clinical benefits and stabilization or slowing of disease progression in patients with Niemann-Pick disease type C1: Results of an international 48-week Phase I/II trial.

Background: Niemann-Pick disease type C (NPC) is a rare, fatal, pan-ethnic, autosomal recessive lysosomal storage disease characterized by progressive major organ failure and neurodegeneration. Preclinical studies confirmed a critical role of systemically administered hydroxypropyl-ß-cyclodextrin (HP-ß-CD; Trappsol® Cyclo™) in cholesterol metabolism and homeostasis in peripheral tissues of the body, including the liver, and in the central nervous system (CNS). Herein, the pharmacokinetics (PK), safety, and efficacy of HP-ß-CD, and biomarkers of NPC were assessed in pediatric and adult patients with NPC1. Methods: This was a multicenter, Phase I/II, randomized, double-blind, parallel-group, 48-week study (ClinicalTrials.gov identifier NCT02912793) to compare the PK of three different single intravenous (IV) doses of HP-ß-CD in pediatric and adult patients with NPC1 and to evaluate the efficacy and tolerability of three different dosages of HP-ß-CD in patients with NPC1 after long-term treatment. Twelve patients aged at least 2 years (2-39 years of age) with a confirmed diagnosis of NPC1 were randomized to receive one of three IV doses of HP-ß-CD (1500 mg/kg, 2000 mg/kg, or 2500 mg/kg) every 2 weeks for 48 weeks. All patients received HP-ß-CD; there was no placebo or other control. PK testing of plasma and cerebrospinal fluid (CSF) was at set times after the first infusion. Pharmacodynamic assessments included biomarkers of cholesterol metabolism (synthesis and breakdown products), N-palmitoyl-O-phosphocholineserine (PPCS), and specific biomarkers of CSF neurodegeneration (including total Tau), CNS inflammation (glial fibrillary acidic protein [GFAP] and tumor necrosis factor α [TNFα]), CNS cholesterol metabolism (24S-hydroxycholesterol) and inflammatory markers. Efficacy measures included clinical disease severity, neurologic symptoms, and clinical impressions of improvement. Safety assessment included physical examination, vital signs, clinical safety laboratory assessment and adverse events (AEs). Results: Nine patients completed the study, 2 in the 1500 mg/kg group, 4 in the 2000 mg/kg group and 3 in the 2500 mg/kg group. Three patients (all in the 1500 mg/kg group) discontinued the study because of either physician decision/site Principal Investigator (PI) discretion, withdrawal by subject/patient/parent/guardian, or other non-safety reasons. In 5 patients who underwent serial lumbar punctures, HP-ß-CD was detected in the CSF. Of the 9 patients who completed the study, 8 (88.9%) improved in at least two domains of the 17-Domain Niemann-Pick disease Type C-Clinical Severity Scale (17D-NPC-CSS), and 6 of these patients improved in at least one domain viewed by patients and their caregivers to be key to quality of life, namely, speech, swallow, fine and gross motor skills, and cognition. Of the 9 patients who completed the study, 7 were viewed by their treating physicians as having improved to some degree at the end of the study, and 2 remained stable; both outcomes are highly relevant in a progressive neurodegenerative disease. Some patients and families reported improvement in quality of life.All three doses of HP-ß-CD were well tolerated overall, with most treatment-emergent adverse events transient, mild-to-moderate in nature, and considered by the site PIs to be not related to study drug. Interpretation: This 48-week trial is the longest to date to evaluate the safety, tolerability, and efficacy across multiple clinical endpoints of IV administration of Trappsol® Cyclo™ (HP-ß-CD) in NPC1 patients. In pediatric and adult patients with NPC, Trappsol® Cyclo™ IV improved clinical signs and symptoms and was generally well tolerated. The findings presented here demonstrate a favorable benefit-risk profile and support the global pivotal trial now underway to evaluate the long-term treatment benefits and the potential of Trappsol® Cyclo™ as a disease-modifying treatment in this patient population.

Loss of Flot2 expression in deep cerebellar nuclei neurons of mice with Niemann-Pick disease type C.

Niemann-Pick disease type C (NPC) is caused by a deficiency of the NPC1 or NPC2 gene, leading to storages of unesterified cholesterol and sphingolipids. Cerebellar ataxia is a main symptom of NPC and the deep cerebellar nuclei (DCN) is the sole signal output of the cerebellum. In this study, we explored the pathological changes in DCN neurons of Npc1 knockout mice (Npc1-). We first demonstrated that DCN neurons of Npc1- mice had prominent ganglioside GM2 accumulation in the late endosomes but not in the lysosomes. More importantly, Flot2 expression, a marker for the lipid rafts, was lost. Single-nucleus RNA sequencing analysis revealed a generalized reduction in gene expression in DCN neurons, though Camk1d, encoding one of the Ca2+/calmodulin-dependent protein kinases (CaMKs), increased in expression. We treated Npc1- mice with CaMK inhibitor KN-93, but CaMK1D expression increased further. We also fed Npc1- mice with two medications for NPC. We found that miglustat, a sphingolipid synthesis inhibitor, increased the expression of Flot2. Moreover, N-acetyl l-leucine (NALL), an experimental medicine for NPC, recovered Flot2 expression. Therefore, our data suggest that in Npc1- mice, GM2 sequestration and the loss of lipid rafts lead to cell dysfunction and symptoms of NPC.

[Argentinean Consensus on the Diagnosis and Treatment of Niemann- Pick Disease Type C]. / Consenso argentino sobre diagnóstico y tratamiento de la enfermedad de Niemann-Pick Tipo C.

Niemann-Pick type C (NPC) is a disorder of the lysosomal metabolism due to biallelic pathogenic variants in NPC1 or NPC2. Intracellular deposit of lipids, mainly unesterified cholesterol, gives rise to oxidative damage in several tissues, mainly neurons, spleen and liver. This, in turn, is associated with a myriad of neurological / psychiatric and visceral symptoms, with wide variability in age of presentation, from prenatal / neonatal to adult-onset forms of the disease. The last few years have seen considerable progress in understanding this disease and its management. In this consensus, current approaches to the diagnosis, follow-up and treatment of NPC (including the use of miglustat, the only specific drug approved at the time) are discussed by an Argentinian panel of experts.

La enfermedad de Niemann-Pick tipo C (NPC) es un trastorno del metabolismo lisosomal que se debe a la presencia de variantes patogénicas bialélicas en los genes NPC1 o NPC2. El depósito intracelular de lípidos, especialmente colesterol no esterificado, provoca daño oxidativo en diversos tejidos, especialmente neuronas, bazo e hígado. Esto, a su vez, induce la aparición de un conjunto de síntomas neurológicos / psiquiátricos y viscerales, con una amplia variabilidad de edad de aparición, desde formas prenatales / neonatales hasta otras de aparición en la vida adulta. En los últimos años ha habido avances considerables en la comprensión sobre esta enfermedad y su manejo. En el presente consenso un grupo de expertos argentinos abordan los enfoques actuales de diagnóstico, seguimiento y tratamiento de NPC, incluyendo el uso de miglustat como única terapia específica aprobada en la actualidad.

Therapeutic Role of Pharmacological Chaperones in Lysosomal Storage Disorders: A Review of the Evidence and Informed Approach to Reclassification.

The treatment landscape for lysosomal storage disorders (LSDs) is rapidly evolving. An increase in the number of preclinical and clinical studies in the last decade has demonstrated that pharmacological chaperones are a feasible alternative to enzyme replacement therapy (ERT) for individuals with LSDs. A systematic search was performed to retrieve and critically assess the evidence from preclinical and clinical applications of pharmacological chaperones in the treatment of LSDs and to elucidate the mechanisms by which they could be effective in clinical practice. Publications were screened according to the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) reporting guidelines. Fifty-two articles evaluating 12 small molecules for the treatment of seven LSDs are included in this review. Overall, a substantial amount of preclinical and clinical data support the potential of pharmacological chaperones as treatments for Fabry disease, Gaucher disease, and Pompe disease. Most of the available clinical evidence evaluated migalastat for the treatment of Fabry disease. There was a lack of consistency in the terminology used to describe pharmacological chaperones in the literature. Therefore, the new small molecule chaperone (SMC) classification system is proposed to inform a standardized approach for new, emerging small molecule therapies in LSDs.

Different solubilizing ability of cyclodextrin derivatives for cholesterol in Niemann-Pick disease type C treatment.

BACKGROUND: Niemann-Pick disease type C (NPC) is a fatal neurodegenerative disorder caused by abnormal intracellular cholesterol trafficking. Cyclodextrins (CDs), the most promising therapeutic candidates for NPC, but with concerns about ototoxicity, are cyclic oligosaccharides with dual functions of unesterified cholesterol (UC) shuttle and sink that catalytically enhance the bidirectional flux and net efflux of UC, respectively, between the cell membrane and the extracellular acceptors. However, the properties of CDs that regulate these functions and how they could be used to improve treatments for NPC are unclear. METHODS: We estimated CD-UC complexation for nine CD derivatives derived from native α-, ß-, and γ-CD with different cavity sizes, using solubility and molecular docking analyses. The stoichiometry and complexation ability of the resulting complexes were investigated in relation to the therapeutic effectiveness and toxicity of each CD derivative in NPC experimental models. FINDINGS: We found that shuttle and sink activities of CDs are dependent on cavity size-dependent stoichiometry and substituent-associated stability of CD-UC complexation. The ability of CD derivatives to form 1:1 and 2:1 complexes with UC were correlated with their ability to normalize intracellular cholesterol trafficking serving as shuttle and with their cytotoxicity associated with cellular UC efflux acting as sink, respectively, in NPC model cells. Notably, the ability of CD derivatives to form an inclusion complex with UC was responsible for not only efficacy but ototoxicity, while a representative derivative without this ability negligibly affected auditory function, underscoring its preventability. CONCLUSIONS: Our findings highlight the importance of strategies for optimizing the molecular structure of CDs to overcome this functional dilemma in the treatment of NPC.

Consenso Argentino sobre Diagnóstico y Tratamiento de la Enfermedad de Niemann-Pick tipo C / Argentinean Consensus on the Diagnosis and Treatment of Niemann-Pick Disease type C

Resumen La enfermedad de Niemann-Pick tipo C (NPC) es un trastorno del metabolismo lisosomal que se debe a la presencia de variantes patogénicas bialélicas en los genes NPC1 o NPC2. El depósito intracelular de lípidos, especialmente colesterol no esterificado, provoca daño oxidativo en diversos tejidos, especialmente neuronas, bazo e hígado. Esto, a su vez, induce la aparición de un conjunto de síntomas neurológicos/psiquiátricos y viscerales, con una amplia variabilidad de edad de apa rición, desde formas prenatales/neonatales hasta otras de aparición en la vida adulta. En los últimos años ha habido avances considerables en la comprensión sobre esta enfermedad y su manejo. En el presente consenso un grupo de expertos argentinos abordan los enfoques actuales de diagnóstico, seguimiento y tratamiento de NPC, incluyendo el uso de miglustat como única terapia específica aprobada en la actualidad.

Abstract Niemann-Pick type C (NPC) is a disorder of the lyso somal metabolism due to biallelic pathogenic variants in NPC1 or NPC2. Intracellular deposit of lipids, mainly unesterified cholesterol, gives rise to oxidative damage in several tissues, mainly neurons, spleen and liver. This, in turn, is associated with a myriad of neurologi cal/psychiatric and visceral symptoms, with wide vari ability in age of presentation, from prenatal/neonatal to adult-onset forms of the disease. The last few years have seen considerable progress in understanding this disease and its management. In this consensus, current approaches to the diagnosis, follow-up and treatment of NPC (including the use of miglustat, the only specific drug approved at the time) are discussed by an Argentin ian panel of experts.

Effects of miglustat therapy on neurological disorder and survival in early-infantile Niemann-Pick disease type C: a national French retrospective study.

BACKGROUND: Niemann-Pick disease type C (NP-C) is a rare neurovisceral lysosomal lipid storage disease characterized by progressive neurodegeneration and premature death. While miglustat can stabilize neurological manifestations in later onset forms of NP-C, its efficacy in the early-infantile neurological form has not been demonstrated. In this observational retrospective study, we compared long-term neurodevelopmental outcome and survival between an untreated and a treated group of early infantile NP-C patients. METHODS: Data available on all NP-C patients with early infantile neurological onset diagnosed in France between 1990 and 2013 were compiled. Patients with incomplete data or who had died from a systemic perinatal, rapidly fatal form were excluded. RESULTS: Ten patients were included in the treated group (year of birth: 2006-2012), and 16 patients in the untreated group [born 1987-2005 (n = 15), 2012 (n = 1)]. The median age at neurological onset was 9 months (5-18) in the treated group, and 12 months (3-18) in the untreated group (p = 0.22). Miglustat therapy was started at a median age of 24.5 months (9-29) and median duration was 30 months (11-56). Gastrointestinal adverse events were reported in 7/10 patients on miglustat. All patients developed loss of psychomotor acquisitions or additional neurological symptoms despite miglustat therapy. The ages of developmental milestones and neurological involvement did not significantly differ between the two groups. Four patients in the untreated group were lost to follow up. The 22 remaining patients had died by the end of the study and no patient survived beyond the age of 7.4 years. The median survival age was 4.42 years in the untreated group and 5.56 years in the treated group; the Kaplan-Meier survival curves were not significantly different (log-rank test: p = 0.11). CONCLUSIONS: Miglustat allowed no significant long-term neurodevelopmental improvement nor significant increase of survival in patients with early infantile NP-C.

NPC1 plays a role in the trafficking of specific cargo to melanosomes.

Niemann-Pick type C1 (NPC1) protein is a multimembrane spanning protein of the lysosome limiting membrane that facilitates intracellular cholesterol and sphingolipid transport. Loss-of-function mutations in the NPC1 protein cause Niemann-Pick disease type C1, a lysosomal storage disorder characterized by the accumulation of cholesterol and sphingolipids within lysosomes. To investigate whether the NPC1 protein could also play a role in the maturation of the endolysosomal pathway, here, we have investigated its role in a lysosome-related organelle, the melanosome. Using a NPC1-KO melanoma cell model, we found that the cellular phenotype of Niemann-Pick disease type C1 is associated with a decreased pigmentation accompanied by low expression of the melanogenic enzyme tyrosinase. We propose that the defective processing and localization of tyrosinase, occurring in the absence of NPC1, is a major determinant of the pigmentation impairment in NPC1-KO cells. Along with tyrosinase, two other pigmentation genes, tyrosinase-related protein 1 and Dopachrome-tautomerase have lower protein levels in NPC1 deficient cells. In contrast with the decrease in pigmentation-related protein expression, we also found a significant intracellular accumulation of mature PMEL17, the structural protein of melanosomes. As opposed to the normal dendritic localization of melanosomes, the disruption of melanosome matrix generation in NPC1 deficient cells causes an accumulation of immature melanosomes adjacent to the plasma membrane. Together with the melanosomal localization of NPC1 in WT cells, these findings suggest that NPC1 is directly involved in tyrosinase transport from the trans-Golgi network to melanosomes and melanosome maturation, indicating a novel function for NPC1.

Novel Mutation in the Feline NPC2 Gene in Cats with Niemann-Pick Disease.

Niemann-Pick disease (NP) type C is an autosomal, recessive, and inherited neurovisceral genetic disorder characterized by the accumulation of unesterified cholesterol and glycolipids in cellular lysosomes and late endosomes, with a wide spectrum of clinical phenotypes. This study aimed to determine the molecular genetic alterations in two cases of felines with NP in Japan, a Siamese cat in 1989 and a Japanese domestic (JD) cat in 1998. Sanger sequencing was performed on 25 exons of the feline NPC1 gene and 4 exons of the feline NPC2 gene, using genomic DNA extracted from paraffin-embedded tissue specimens. The sequenced exons were compared with reference sequences retrieved from the GenBank database. The identified mutations and alterations were then analyzed using different prediction algorithms. No pathogenic mutations were found in feline NPC1; however, c.376G>A (p.V126M) was identified as a pathogenic mutation in the NPC2 gene. The Siamese cat was found to be homozygous for this mutation. The JD cat was heterozygous for the same mutation, but no other exonic NPC2 mutation was found. Furthermore, the JD cat had a homozygous splice variant (c.364-4C>T) in the NPC2 gene, which is not known to be associated with this disease. The NPC2:c.376G>A (p.V126M) mutation is the second reported pathogenic mutation in the feline NPC2 gene that may be present in the Japanese cat population.