Niemann-Pick Type Research Articles

Results of a phase III, randomized, placebo-controlled crossover trial with N-acetyl-L-leucine for Niemann-Pick disease type C

Results of a phase III, randomized, placebo-controlled crossover trial with N-acetyl-L-leucine for Niemann-Pick disease type C

What lies beneath: Next generation sequencing unraveling Niemann-Pick disease type C in adults

What lies beneath: Next generation sequencing unraveling Niemann-Pick disease type C in adults

Transport®NPC: open phase 3 global trial of intravenous hydroxy-propyl-beta-cyclodextrin in patients with Niemann-Pick disease type C1 (NPC1)

Transport®NPC: open phase 3 global trial of intravenous hydroxy-propyl-beta-cyclodextrin in patients with Niemann-Pick disease type C1 (NPC1)

PPCS, the biomarker with the best clinical utility for Niemann-Pick disease type B?

PPCS, the biomarker with the best clinical utility for Niemann-Pick disease type B?

Real-world data collection in Niemann-Pick disease type C: Data from expanded access program with arimoclomol

Real-world data collection in Niemann-Pick disease type C: Data from expanded access program with arimoclomol

Severe form of Niemann-Pick disease type B in Iranian population: A review of the spectrum of disease in acid sphingomyelinase deficiency

Severe form of Niemann-Pick disease type B in Iranian population: A review of the spectrum of disease in acid sphingomyelinase deficiency

Novel compound heterozygous mutations of the NPC1 gene associated with Niemann-pick disease type C: a case report and review of the literature

BackgroundNiemann-Pick Disease type C is a fatal autosomal recessive lipid storage disorder caused by NPC1 or NPC2 gene mutations and characterized by progressive, disabling neurological deterioration and hepatosplenomegaly. Herein, we identified a novel compound heterozygous mutations of the NPC1 gene in a Chinese pedigree.Case presentationThis paper describes an 11-year-old boy with aggravated walking instability and slurring of speech who presented as Niemann-Pick Disease type C. He had the maternally inherited c.3452 C > T (p. Ala1151Val) mutation and the paternally inherited c.3557G > A (p. Arg1186His) mutation using next-generation sequencing. The c.3452 C > T (p. Ala1151Val) mutation has not previously been reported.ConclusionsThis study predicted that the c.3452 C > T (p. Ala1151Val) mutation is pathogenic. This data enriches the NPC1 gene variation spectrum and provides a basis for familial genetic counseling and prenatal diagnosis.

Niemann-Pick Type C2 Proteins in Aedes aegypti: Molecular Modelling and Prediction of Their Structure-Function Relationships.

Aedes aegypti is a major vector that transmits arboviruses through the saliva injected into the host. Salivary proteins help in uninterrupted blood intake and enhance the transmission of pathogens. We studied Niemann-Pick Type C2 (NPC2) proteins, a superfamily of saliva proteins that play an important role in arbovirus infections. In vertebrates, a single conserved gene encodes for the NPC2 protein that functions in cholesterol trafficking. Arthropods, in contrast, have several genes that encode divergent NPC2 proteins. We compared the sequences of 20 A. aegypti NPC2 proteins to the cholesterol-binding residues of human and bovine, and fatty-acid-binding residues of ant NPC2 protein. We identified four mosquito NPC2 proteins as potential sterol-binding proteins. Two of these proteins (AAEL006854 and/or AAEL020314) may play a key role in ecdysteroid biosynthesis and moulting. We also identified one mosquito NPC2 protein as a potential fatty-acid-binding protein. Through molecular modelling, we predicted the structures of the potential sterol- and fatty-acid-binding proteins and compared them to the reference proteins.

Filipin complex-reactive brain lesions: a cautionary tale.

Filipin complex is an autooxidation-prone fluorescent histochemical stain used in the diagnosis of Niemann-Pick Disease Type C (NP-C), a neurodegenerative lysosomal storage disorder. It is also widely used by researchers examining the distribution and accumulation of unesterified cholesterol in cell and animal models of neurodegenerative diseases including NP-C and Sanfilippo syndrome (mucopolysaccharidosis IIIA; MPS IIIA). Recently, it has been suggested to be useful in studying Alzheimer's and Huntington's disease. Given filipin's susceptibility to photobleaching, we sought to establish a quantitative biochemical method for free cholesterol measurement. Brain tissue from mice with MPS IIIA was stained with filipin. Total and free cholesterol in brain homogenates was measured using a commercially available kit and a quantitative LC-MS/MS assay was developed. Gangliosides GM1, GM2 and GM3 were also quantified using LC-MS/MS. As anticipated, the MPS IIIA mouse brain displayed large numbers of filipin-positive intra-cytoplasmic inclusions, presumptively endo-lysosomes. Challenging the prevailing dogma, however, we found no difference in the amount of free cholesterol in MPS IIIA mouse brain homogenates cf. control tissue, using either the fluorometric kit or LC-MS/MS assay. Filipin has previously been reported to bind to GM1 ganglioside, however, this lipid does not accumulate in MPS IIIA cells/tissues. Using a fluorometric assay, we demonstrate for the first time that filipin cross-reacts with both GM2 and GM3 gangliosides, explaining the filipin-reactive inclusions observed in MPS IIIA brain cells. Filipin is not specific for free cholesterol, and positive staining in any setting should be interpreted with caution.

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.

Uncovering the Challenges of Rare Diseases: Insights From a Retrospective Cross-Sectional Study in Albania (2005-2022).

Diagnosing and treating rare diseases pose significant challenges within global healthcare systems due to their low prevalence and varying criteria for defining them. In Albania, the absence of a dedicated registry for rare diseases exacerbates these challenges. Recognising this gap, a retrospective cross-sectional study was conducted from January 2005 to December 2022 to analyse the incidence and prevalence of rare haematologic diseases in the country, diagnosed in the Hematology Service at the University Hospital Centre "Mother Teresa," which is the sole diagnostic center for blood diseases in Albania. This study aims to provide insights into the frequency of these diseases within the adult Albanian population and seeks to underscore the critical need for improved data collection and research in this field of healthcare. The primary objective of this study is to assess the incidence and prevalence of rare hematologic diseases diagnosed at the Hematology Service of the University Hospital Centre "Mother Teresa" in Albania from January 2005 to December 2022. This retrospective cross-sectional study employed a descriptive study design, focusing on the analysis of rare hematologicdisease incidence and prevalence. The study was conducted exclusively at the University Hospital Centre "Mother Teresa" in Albania, the primary diagnostic center for blood-related disorders in the country. Data collection spanned a period of 18 years, from January 2005 to December 2022, encompassing patient records. Inclusion criteria encompassed adult patients aged 15 years and older who had received diagnoses of rare hematologic diseases during the specified timeframe, without specific operational definitions applied. Non-probability convenience sampling was used, including all eligible cases identified within the study's timeframe, obviating the need for formal sample size calculation. Data were extracted from the records of the Hematology Service at the University Hospital Centre "Mother Teresa," primarily using medical records containing essential patientinformation. Data analysis utilised software such as EXCEL 16.0 and SPSS (v. 25.0), applying descriptive statistical methods, including frequencies and percentages, to assess the incidence and prevalence of rare hematologic diseases. The study's findings were summarised and presented in a tabular format to provide a clear and concise overview of the results. Our study identified 64 cases of rare hematologic diseases among adults. Notably, primary myelofibrosis (MF) exhibited the highest incidence andprevalence rate, followed byWaldenström macroglobulinemia (WM) and Gaucher disease (GD) emerging as the most prevalent diagnoses after MF, with 16 and 10 cases, respectively. Several ultra-rare diseases, such as Fanconi anemia and chronic eosinophilic leukemia, were also detected, indicating a significant disease burden, while diseases such as Factor X deficiency and Niemann-Pick disease type C were exceptionally rare. Diagnosing and treating rare diseases remain formidable challenges in healthcare systems worldwide. This study underscores the need for enhanced awareness, research, and thepressing need for dedicated registries, collaborative research initiatives, and heightened attention to these conditions to enhance our understanding and management of rare hematological diseases, particularly within the Albanian healthcare context.

Cyclodextrins as therapeutic drugs for treating lipid metabolism disorders.

This study sought to systematically compare the efficacy and mechanism of cyclodextrins as drug interventions in lipid metabolism diseases, potentially providing ideas for subsequent research directions and clinical applications. We used the bibliometric method for feature mining, applied VOSviewer software for clustering analysis, and applied content analysis for objective descriptions and accurate analysis. (1) We collected more than 50 studies, which is the basic database of this study. (2) The academic bubble map showed that this research area was popular in the United States. (3) Cluster analysis showed that the intensively studied diseases in this field were Niemann-Pick type C (NPC), atherosclerosis (AS), and obesity. The hot-spot cyclodextrin types were HP-β-CD. (4) Literature measurement revealed the involvement of 15 types of lipid metabolism diseases. Among them, NPC, diabetes, and obesity were studied in clinical trials. Dyslipidemia and AS have been reported relatively more frequently in animal experiments. The studies of cellular experiments provide insight into the molecular mechanisms that intervene in lipid metabolism diseases from multiple perspectives. The exploration of the molecular mechanisms by which cyclodextrins exert their pharmacological effects mainly revolves around lipid metabolism. It is worthwhile to investigate the role and mechanism of cyclodextrins in other lipid metabolism diseases. The potential efficacy evaluation of cyclodextrins as pharmaceutical drugs for oral or injectable formulations is less studied and may become a new focus in the future.

Fut2 Deficiency Promotes Intestinal Stem Cell Aging by Damaging Mitochondrial Functions via Down-Regulating α1,2-Fucosylation of Asah2 and Npc1.

Fut2-mediated α1,2-fucosylation is important for gut homeostasis, including the intestinal stem cell (ISC). The stemness of ISC declines with age, and aging-associated ISC dysfunction is closely related to many age-related intestinal diseases. We previously found intestinal epithelial dysfunction in some aged Fut2 knockout mice. However, how Fut2-mediated α1,2-fucosylation affects ISC aging is still unknown. On this basis, the herein study aims to investigate the role of Fut2-mediated α1,2-fucosylation in ISC aging. Aging models in ISC-specific Fut2 knockout mice were established. ISCs were isolated for proteomics and N-glycoproteomics analysis. ISC functions and mitochondrial functions were examined in mice and organoids. Ulex europaeus agglutinin I chromatography and site-directed mutagenesis were used to validate the key target fucosylated proteins of Fut2. As a result, Fut2 knockout impaired ISC stemness and promoted aging marker expression in aged mice. Proteomics analysis indicated mitochondrial dysfunction in Fut2 knockout ISC. More injured mitochondria, elevated levels of reactive oxygen species, and decreased levels of adenosine 5'-triphosphate (ATP) in Fut2 knockout ISC were found. Moreover, respiratory chain complex impairment and mitophagy dysfunction in Fut2 knockout ISC were further noted. Finally, Fut2 was demonstrated to regulate mitochondrial functions mainly by regulating the α1,2-fucosylation of N-acyl sphingosine amidohydrolase 2 (Asah2) and Niemann-Pick type C intracellular cholesterol transporter 1 (Npc1). In conclusion, this study demonstrated the substantial role of Fut2 in regulating ISC functions during aging by affecting mitochondrial function. These findings provide novel insights into the molecular mechanisms of ISC aging and therapeutic strategies for age-related intestinal diseases.

Besnoitia besnoiti tachyzoite replication in bovine primary endothelial cells relies on host Niemann-Pick type C protein 1 for cholesterol acquisition.

Besnoitia besnoiti is a cyst-forming apicomplexan parasite and the causal agent of bovine besnoitiosis. During early phase of infection, tachyzoites replicate within host endothelial cells in a host cell cholesterol-dependent process. By applying U18666A treatments, we here evaluated the role of Niemann-Pick type C protein 1 (NPC1) in both, intracellular B. besnoiti replication and host cellular cholesterol distribution. Additionally, B. besnoiti-driven changes in NPC1 gene transcription were studied by qPCR. Overall, U18666A treatments significantly reduced B. besnoiti proliferation and induced cholesterol accumulation in host cytoplasmic dense vesicles. However, NPC1 gene transcription was not affected by B. besnoiti infection.

Selective labelling of GBA2 in cells with fluorescent β-d-arabinofuranosyl cyclitol aziridines.

GBA2, the non-lysosomal β-glucosylceramidase, is an enzyme involved in glucosylceramide metabolism. Pharmacological inhibition of GBA2 by N-alkyl iminosugars is well tolerated and benefits patients suffering from Sandhoff and Niemann-Pick type C diseases, and GBA2 inhibitors have been proposed as candidate-clinical drugs for the treatment of parkinsonism. With the ultimate goal to unravel the role of GBA2 in (patho)physiology, we sought to develop a GBA2-specific activity-based probe (ABP). A library of probes was tested for activity against GBA2 and the two other cellular retaining β-glucosidases, lysosomal GBA1 and cytosolic GBA3. We show that β-d-arabinofuranosyl cyclitol aziridine (β-d-Araf aziridine) reacts with the GBA2 active site nucleophile to form a covalent and irreversible bond. Fluorescent β-d-Araf aziridine probes potently and selectively label GBA2 both in vitro and in cellulo, allowing for visualization of the localization of overexpressed GBA2 using fluorescence microscopy. Co-staining with an antibody selective for the lysosomal β-glucosylceramidase GBA1, shows distinct subcellular localization of the two enzymes. We proffer our ABP technology for further delineating the role and functioning of GBA2 in disease and propose the β-d-Araf aziridine scaffold as a good starting point for the development of GBA2-specific inhibitors for clinical development.

The paracaspase MALT1 controls cholesterol homeostasis in glioblastoma stem-like cells through lysosome proteome shaping

Glioblastoma stem-like cells (GSCs) compose a tumor-initiating and -propagating population remarkably vulnerable to variation in the stability and integrity of the lysosomal compartment. Previous work has shown that the expression and activity of the paracaspase MALT1 control GSC viability via lysosome abundance. However, the underlying mechanisms remain elusive. By combining RNA sequencing (RNA-seq) with proteome-wide label-free quantification, we now report that MALT1 repression in patient-derived GSCs alters the homeostasis of cholesterol, which accumulates in late endosomes (LEs)-lysosomes. This failure in cholesterol supply culminates in cell death and autophagy defects, which can be partially reverted by providing exogenous membrane-permeable cholesterol to GSCs. From a molecular standpoint, a targeted lysosome proteome analysis unraveled that Niemann-Pick type C (NPC) lysosomal cholesterol transporters are diluted when MALT1 is impaired. Accordingly, we found that NPC1/2 inhibition and silencing partially mirror MALT1 loss-of-function phenotypes. This supports the notion that GSC fitness relies on lysosomal cholesterol homeostasis.

Unraveling the Connection: Cholesterol, Calcium Signaling, and Neurodegeneration.

Cholesterol and calcium play crucial roles as integral structural components and functional signaling entities within the central nervous system. Disruption in cholesterol homeostasis has been linked to Alzheimer's, Parkinson's, and Huntington's Disease while alterations in calcium signaling is hypothesized to be a key substrate for neurodegeneration across many disorders. Despite the importance of regulated cholesterol and calcium homeostasis for brain health there has been an absence of research investigating the interdependence of these signaling molecules and how they can tune each other's abundance at membranes to influence membrane identity. Here, we discuss the role of cholesterol in shaping calcium dynamics in a neurodegenerative disorder that arises due to mutations in the lysosomal cholesterol transporter, Niemann Pick Type C1 (NPC1). We discuss the molecular mechanisms through which altered lysosomal cholesterol transport influences calcium signaling pathways through remodeling of ion channel distribution at organelle-organelle membrane contacts leading to neurodegeneration. This scientific inquiry not only sheds light on NPC disease but also holds implications for comprehending other cholesterol-associated neurodegenerative disorders.

Neonatal presentation of Niemann-Pick disease type C2- A rare case report.

Niemann Pick type C [NP-C] disease is a rare neurodegenerative lysosomal storage disorder marked by an accumulation of unesterified cholesterol in the lysosomal system. It has autosomal recessive inheritance caused by mutations in NPC1 and NPC2 genes. The broad clinical spectrum ranges from a prenatal severe manifestation to an adult-onset chronic neurodegenerative disease. The manifestations in the perinatal period and infancy are predominantly visceral, with hepatosplenomegaly, jaundice, and pulmonary infiltrates (in some instances). Patients with NP-C usually do not show neurological manifestations during the neonatal period. Herein we present a case of neonatal cholestasis with hepatosplenomegaly and anaemia, which was diagnosed as Niemann Pick disease type C2. Thus, NP-C is an important differential diagnosis of neonatal cholestasis in the presence of visceromegaly.

Late adult-onset Niemann Pick type C (NPC): An “atypical” typical presentation at the age of 62. Expert commentary

Late adult-onset Niemann Pick type C (NPC): An “atypical” typical presentation at the age of 62. Expert commentary

Prosopagnosia: face blindness and its association with neurological disorders.

Loss of facial recognition or prosopagnosia has been well-recognized for over a century. It has been categorized as developmental or acquired depending on whether the onset is in early childhood or beyond, and acquired cases can have degenerative or non-degenerative aetiologies. Prosopagnosia has been linked to involvement of the fusiform gyri, mainly in the right hemisphere. The literature on prosopagnosia comprises case reports and small case series. We aim to assess demographic, clinical and imaging characteristics and neurological and neuropathological disorders associated with a diagnosis of prosopagnosia in a large cohort. Patients were categorized as developmental versus acquired; those with acquired prosopagnosia were further subdivided into degenerative versus non-degenerative, based on neurological aetiology. We assessed regional involvement on [18F] fluorodeoxyglucose-PET and MRI of the right and left frontal, temporal, parietal and occipital lobes. The Intake and Referral Center at the Mayo Clinic identified 487 patients with possible prosopagnosia, of which 336 met study criteria for probable or definite prosopagnosia. Ten patients, 80.0% male, had developmental prosopagnosia including one with Niemann-Pick type C and another with a forkhead box G1 gene mutation. Of the 326 with acquired prosopagnosia, 235 (72.1%) were categorized as degenerative, 91 (27.9%) as non-degenerative. The most common degenerative diagnoses were posterior cortical atrophy, primary prosopagnosia syndrome, Alzheimer's disease dementia and semantic dementia, with each diagnosis accounting for >10% of this group. The most common non-degenerative diagnoses were infarcts (ischaemic and haemorrhagic), epilepsy-related and primary brain tumours, each accounting for >10%. We identified a group of patients with non-degenerative transient prosopagnosia in which facial recognition loss improved or resolved over time. These patients had migraine-related prosopagnosia, posterior reversible encephalopathy syndrome, delirium, hypoxic encephalopathy and ischaemic infarcts. On [18F] fluorodeoxyglucose-PET, the temporal lobes proved to be the most frequently affected regions in 117 patients with degenerative prosopagnosia, while in 82 patients with non-degenerative prosopagnosia, MRI revealed the right temporal and right occipital lobes as most affected by a focal lesion. The most common pathological findings in those with degenerative prosopagnosia were frontotemporal lobar degeneration with hippocampal sclerosis and mixed Alzheimer's and Lewy body disease pathology. In this large case series of patients diagnosed with prosopagnosia, we observed that facial recognition loss occurs across a wide range of acquired degenerative and non-degenerative neurological disorders, most commonly in males with developmental prosopagnosia. The right temporal and occipital lobes, and connecting fusiform gyrus, are key areas. Multiple different pathologies cause degenerative prosopagnosia.