Search Results (163)

Due to their clinical heterogeneity, nonspecific symptoms, and the limitations of existing biomarkers and imaging modalities, metabolic brain diseases (MBDs), such as mitochondrial encephalopathies, lysosomal storage disorders, and glucose metabolism syndromes, pose significant diagnostic challenges. This review examines the growing potential of cell-free DNA (cfDNA) derived from cerebrospinal fluid (CSF) epigenetic profiling as a dynamic, cell-type-specific, minimally invasive biomarker approach for MBD diagnosis and monitoring. We review important technological platforms and their use in identifying CNS-specific DNA methylation patterns indicative of neuronal injury, neuroinflammation, and metabolic reprogramming, including cfMeDIP-seq, enzymatic methyl sequencing (EM-seq), and targeted bisulfite sequencing. By synthesizing current findings across disorders such as MELAS, Niemann–Pick disease, Gaucher disease, GLUT1 deficiency syndrome, and diabetes-associated cognitive decline, we highlight the superior diagnostic and prognostic resolution offered by CSF cfDNA methylation signatures relative to conventional CSF markers or neuroimaging. We also address technical limitations, interpretive challenges, and translational barriers to clinical implementation. Ultimately, this review explores CSF cfDNA epigenetic analysis as a liquid biopsy modality. The central objective is to assess whether epigenetic profiling of CSF-derived cfDNA can serve as a reliable and clinically actionable biomarker for improving the diagnosis and longitudinal monitoring of metabolic brain diseases. Full article

Background/Objectives: Niemann-Pick disease Type C (NPC) represents an autosomal recessive disorder with an incidence rate of 1 in 100,000 live births that belongs to the lysosomal storage diseases (LSDs). NPC is characterized by the abnormal accumulation of unesterified cholesterol, in addition to being an autosomal recessive inherited pathology, which belongs to LSDs. It occurs in 95% of cases due to mutations in the NPC1 gene, while 5% of cases are due to mutations in the NPC2 gene. In the cerebral cortex (CC), the disease shows lipid inclusions, increased cholesterol and multiple sphingolipids in neuronal membranes, and protein aggregates such as hyperphosphorylated tau, α-Synuclein, TDP-43, and β-amyloid peptide. Mitochondrial damage and oxidative stress are some alterations at the cellular level in NPC. Therefore, the aim of this work was to determine the gene expression profile in the CC of NPC1 mice in order to identify altered molecular pathways that may be related to the pathophysiology of the disease. Methods: In this study, we performed a microarray analysis of a 22,000-gene chip from the cerebral cortex of an NPC mutant mouse compared to a WT mouse. Subsequently, we performed a bioinformatic analysis in which we found groups of dysregulated genes, and their expression was corroborated by qPCR. Finally, we performed Western blotting to determine the expression of proteins probably dysregulated. Results: We found groups of dysregulated genes in the cerebral cortex of the NPC mouse involved in the ubiquitination, fatty acid metabolism, differentiation and development, and underexpression in genes with mitochondrial functions, which could be involved in intrinsic apoptosis reported in NPC, in addition, we found a generalized deregulation in the cortical circadian rhythm pathway, which could be related to the depressive behavior that has even been reported in NPC patients. Conclusions: Recognizing that there are changes in the expression of genes related to ubiquitination, mitochondrial functions, and cortical circadian rhythm in the NPC mutant mouse lays the basis for targeting treatments to new potential therapeutic targets. Full article

Defects in lysosomal cholesterol handling provoke fatal disorders presenting neurovisceral symptoms with variable onset and life spans. A prime example is Niemann–Pick type C disease (NPCD), where cholesterol export from the endosomal–lysosomal system is impaired due to variants of either NPC intracellular cholesterol transporter 1 (NPC1) or NPC intracellular cholesterol transporter 2 (NPC2). Therapeutic options for NPCD are limited to palliative care and disease-modifying drugs, and there is a need for new treatments. Here, we explored bromodomain and extra-terminal domain (BET) proteins as new drug targets for NPCD using patient-derived skin fibroblasts. Treatment with JQ1, a prototype BET protein inhibitor, raised the level of NPC1 protein, diminished lysosomal expansion and cholesterol accumulation, and induced extracellular release of lysosomal components in a dose-, time-, and patient-dependent manner. Lastly, JQ1 enhanced and reduced cholesterol accumulation induced by pharmacologic inhibition of NPC1 and of histone deacetylase (HDAC) activity, respectively. Taken together, bromodomain proteins should be further explored as therapeutic drug targets for lysosomal diseases like NPCD, and as new components regulating lysosomal function and cholesterol metabolism. Full article

Background: Lysosomal storage disorders (LSDs) are rare inherited metabolic diseases characterized by defects in lysosomal enzyme function or membrane transport. These defects lead to substrate accumulation and multisystemic manifestations. This review focuses on gastrointestinal (GI) involvement in LSDs, which is a significant but often overlooked aspect of these disorders. Methods: A comprehensive literature review was conducted to examine the pathophysiology, clinical presentation, diagnosis and management of GI manifestations in several LSDs, including Fabry disease, Gaucher disease, Pompe disease, Niemann–Pick disease type C, mucopolysaccharidoses and Wolman disease. Results: The pathogenesis of GI involvement in LSDs varies and encompasses substrate accumulation in enterocytes, mesenteric lymphadenopathy, mass effects, smooth muscle dysfunction, vasculopathy, neuropathy, inflammation and alterations to the microbiota. Clinical presentations range from non-specific symptoms, such as abdominal pain, diarrhea and malabsorption, to more severe complications, such as protein-losing enteropathy and inflammatory bowel disease. Diagnosis often requires a high level of suspicion, as GI symptoms may precede the diagnosis of the underlying LSD or be misattributed to more common conditions. Management strategies include disease-specific treatments, such as enzyme replacement therapy or substrate reduction therapy, as well as supportive care and targeted interventions for specific GI complications. Conclusions: This review highlights the importance of recognizing and properly managing GI manifestations in LSDs to improve patient outcomes and quality of life. It also emphasizes the need for further research to develop more effective treatments for life-threatening GI complications associated with these rare genetic disorders. Full article

Lysosomal storage diseases (LSDs) are characterized by the accumulation of undegraded substrates within lysosomes, often associated with oxidative stress and impaired lysosomal function. In this study, we investigate the role of the c-Abl/TFEB pathway in different LSDs: Gaucher, Niemann-Pick type A (NPA), and Niemann-Pick type C (NPC). Our findings identify c-Abl activation (p-c-Abl) as a common pathogenic mechanism in these disorders. We demonstrate that c-Abl phosphorylates TFEB at Tyr173, leading to its cytoplasmic retention. Using pharmacological models of Gaucher, NPA and NPC in SH-SY5Y neuronal cells and HeLa cells, we assess the effects of the c-Abl inhibitors Imatinib and Neurotinib, as well as the antioxidant α-Tocopherol (α-TOH), on TFEB nuclear translocation and p-c-Abl protein levels. Additionally, we explore the effects of c-Abl inhibitors in cholesterol accumulation in LSDs neuronal models. Our results show that treatment with c-Abl inhibitors or α-TOH promotes TFEB nuclear translocation, enhances lysosomal clearance, and reduces cholesterol accumulation in all three LSD models. These findings highlight the c-Abl/TFEB pathway as a potential therapeutic target for LSDs and potentially other neurodegenerative disorders associated with lysosomal dysfunction. Full article

This article profiles 27 innovative advancements in small-molecule drugs approved by the U.S. Food and Drug Administration (FDA) in 2024. These drugs target various therapeutic areas including non-small cell lung cancer, advanced or metastatic breast cancer, glioma, relapsed or refractory acute leukemia, urinary tract infection, Staphylococcus aureus bloodstream infections, nonalcoholic steatohepatitis, primary biliary cholangitis, Duchenne muscular dystrophy, hypertension, anemia due to chronic kidney disease, extravascular hemolysis, primary axillary hyperhidrosis, chronic obstructive pulmonary disease, severe alopecia areata, WHIM syndrome, Niemann–Pick disease type C, schizophrenia, supraventricular tachycardia, congenital adrenal hyperplasia, and cystic fibrosis. Among these approved small-molecule drugs, those with unique mechanisms of action and designated as breakthrough therapies by the FDA represent a significant proportion, highlighting ongoing innovation. Notably, eight of these drugs (including Rezdiffra^®, Voydeya^®, Iqirvo^®, Voranigo^®, Livdelzi^®, Miplyffa^®, Revuforj^®, and Crenessity^®) are classified as “first-in-class” and have received breakthrough therapy designation. These agents not only exhibit distinct mechanisms of action but also offer substantial improvements in efficacy for patients compared to prior therapeutic options. This article offers a comprehensive analysis of the mechanisms of action, clinical trials, drug design, and synthetic methodologies related to representative drugs, aiming to provide crucial insights for future pharmaceutical development. Full article

Niemann–Pick Disease Type C (NPC) is a hereditary neurodegenerative disease characterized by selective cell vulnerability, particularly affecting cerebellar anterior Purkinje neurons. These neurons exhibit a distinctive pattern of degeneration due to the loss of NPC1 and/or NPC2 protein function, progressively extending towards posterior cerebellar regions. Our study aimed to explore the early factors influencing this selective vulnerability of anterior Purkinje neurons in NPC. Oxytosis/ferroptosis, a novel form of regulated cell death, has been implicated in neurodegenerative diseases, with its inhibition showing promising therapeutic potential. Our laboratory has previously identified parallels between NPC cellular pathology and ferroptotic markers, including elevated levels of lipid peroxidation and iron, mitochondrial dysfunction, and Ca²⁺ dyshomeostasis. However, whether oxytosis/ferroptosis underlies NPC cellular pathology remains unexplored. We hypothesize that loss of NPC1 function increases vulnerability to ferroptosis and that anti-ferroptotic compounds will reverse NPC cellular pathology. Through bioinformatic analyses of pre-symptomatic Npc1^−/− Purkinje neurons and in vitro studies using primary dermal fibroblasts derived from NPC patients, we provide evidence suggesting that oxytosis/ferroptosis may play a pathogenic role in NPC. These findings highlight the potential of anti-ferroptotic compounds as a promising therapeutic strategy to mitigate neurodegeneration in NPC and potentially other related disorders. Full article

In 2024, the FDA approved fifty novel drugs, including four peptides and oligonucleotides (TIDEs) (two pepTIDEs and two oligonucleoTIDEs), highlighting their increasing importance as effective alternatives to traditional drug classes. TIDEs provide essential therapies for complex diseases, such as genetic disorders, rather than merely addressing symptoms. In addition to oligonucleotide therapeutics for various genetic conditions, peptides became the first approved treatment for Rett Syndrome in 2023 and were also used to treat Niemann–Pick disease type C (NPC) in 2024. Interestingly, among the strategies employed in recent approvals to enhance stability and/or delivery, the prodrug approach, exemplified by palopegteriparatide and pegulicianine, is emerging as a more targeted and precise therapeutic strategy. Additionally, the Enhanced Stabilization Chemistry (ESC)-GalNAc platform has been expanded for hepatic delivery of a new oligonucleotide drug, olezarsen. Furthermore, novel modifications to the ribose moiety in oligonucleotides, such as the 3′-amino substitution in imetelstat, enhance their stability. This review examines the TIDES approved in 2024 based on their chemical structure, medical targets, modes of action, administration routes, and common adverse effects. In addition, it highlights how the prodrug strategy has improved targeting efficiency and extended the half-lives of the active drugs. Full article

DHDDS (dehydrodolichol diphosphate synthetase) and NgBR (Nogo-B Receptor) collectively form an enzymatic complex important for the synthesis of dolichol, a key component of protein N-glycosylation. Mutations in DHDDS and the gene encoding NgBR (NUS1) are associated with neurodevelopmental disorders that clinically present with epilepsy, motor impairments, and developmental delay. Previous work has demonstrated both DHDDS and NgBR can also interact with NPC2 (Niemann-Pick C (NPC) type 2), a protein which functions to traffic cholesterol out of the lysosome and, when mutated, can cause a lysosomal storage disorder (NPC disease) characterised by an accumulation of cholesterol and glycosphingolipids. Abnormal cholesterol accumulation has also been reported in cells from both individuals and animal models with mutations in NUS1, and suspected lipid storage has been shown in biopsies from individuals with mutations in DHDDS. Our findings provide further evidence for overlap between NPC2 and DHDDS disorders, showing that DHDDS patient fibroblasts have increased lysosomal volume, store cholesterol and ganglioside GM1, and have altered lysosomal Ca²⁺ homeostasis. Treatment of DHDDS cells, with the approved NPC small molecule therapy, miglustat, improves these disease-associated phenotypes, identifying a possible therapeutic option for DHDDS patients. These data suggest that treatment options currently approved for NPC disease may be translatable to DHDDS/NUS1 patients. Full article

Objective: Cholesin is a recently discovered gut-derived hormone secreted by enterocytes upon dietary cholesterol uptake via the transmembrane sterol transporter Niemann–Pick disease C1-like intracellular cholesterol transporter 1 (NPC1L1). In the liver, cholesin activates G protein-coupled receptor 146 (GPR146), causing reduced cholesterol synthesis. In this exploratory, hypothesis-generating study based on post hoc analysis, human data on the cholesin system are presented. Methods: Mucosal biopsies were collected throughout the intestinal tract from 12 individuals with type 2 diabetes (T2D) and 12 healthy, matched controls. Upper small intestinal mucosal biopsies were collected from 20 individuals before and after Roux-en-Y gastric bypass (RYGB) surgery. Liver biopsies were collected from 12 men with obesity and 15 matched controls without obesity. Subcutaneous abdominal adipose tissue biopsies were collected from 20 men with type 1 diabetes (T1D). All biopsies underwent full mRNA sequencing. Results: Cholesin mRNA expression was observed throughout the intestinal tracts of the individuals with T2D and the controls, in the livers of men with and without obesity, and in adipose tissue of men with T1D. NPC1L1 mRNA expression was robust throughout the small intestines but negligible in the large intestines of both individuals with and without T2D. RYGB surgery induced the expression of NPC1L1 mRNA in the upper small intestine. GPR146 mRNA was expressed in the livers of men, both with and without obesity, and in the adipose tissue of men with T1D, but not in the intestines. Conclusions: Our results suggest a role of the cholesin system in human physiology, but whether it is perturbed in metabolic diseases remains unknown. Clinical trial registration numbers: NCT03044860, NCT03093298, NCT02337660, NCT03734718. Full article

Niemann–Pick type C (NPC) is a lysosomal storage disorder (LSD) caused by pathogenic variants in either the NPC1 or NPC2 genes, which encode proteins involved in the lysosomal export of unesterified cholesterol. In patients of Western European descent, the p.Ile1061Thr variant in NPC1 is especially prevalent. However, mounting evidence has positioned p.Ala1035Val as the most common variant in Portugal and the second most prevalent variant worldwide. By analyzing 10 Portuguese NPC patients homozygous for p.Ala1035Val, we found an SNP in cis on position 858 (p.Ile858Val), which we hypothesize could have a disease-modifying effect. To address this query, we created variant-specific in vitro models of NPC by stably transducing NPC1^−/− ARPE-19 cells with constructs encoding different fluorescently-tagged variants of NPC1, which we used, alongside patient-derived skin fibroblasts, to investigate lysosomal positioning and the trafficking routes elicited by p.Ile1061Thr and p.Ala1035Val (with and without the p.Ile858Val SNP in cis). Our results corroborate the previously described decrease in p.Ile1061Thr-NPC1 trafficking to the lysosome and suggest a similar, if not worse, scenario for the p.Ala1035Val variant, especially when in cis with p.Ile858Val. This is the first reported functional study addressing the impact of the p.Ala1035Val variant at the cellular level, paving the way for novel therapeutic options. Full article

Niemann–Pick type C (NPC) disease is an autosomal recessive lysosomal storage disorder where 95% of the cases are caused by mutations in the Niemann–Pick C1 (NPC1) gene. Loss of function in NPC1 mutants trigger the accumulation of cholesterol in late endo-lysosomes and lysosomal dysfunction. The current study examined the potential of polyphenol-rich methanol extracts from Rosa canina L. (RCME) and two of its components, rutin and quercitrin, to enhance protein trafficking of NPC1 and restore cholesterol levels in fibroblasts derived from NPC patients, in comparison with miglustat, a drug approved in Europe for NPC treatment. Interestingly, RCME improved the trafficking of the compound heterozygous mutant NPC1^I1061T/P887L, homozygous mutant NPC1^R1266Q, and heterozygous mutant NPC1^N1156S between the endoplasmic reticulum and the Golgi and significantly reduced the levels of cellular cholesterol in the cell lines examined. Miglustat did not affect the trafficking of the three NPC1 mutants individually nor in combination with RCME. Markedly, rutin and quercitrin exerted their effects on cholesterol, but not in the trafficking pathway of NPC1, indicating that other components in RCME are implicated in regulating the trafficking of NPC1 mutants. By virtue of its dual function in targeting the trafficking of mutants of NPC1 as well as the cholesterol contents, RCME is more beneficial than available drugs that target substrate reduction and should be therefore considered in further studies for its feasibility as a therapeutic agent for NPC patients. Full article

Lysosomal storage diseases (LSDs) are caused by the deficient activity of a lysosomal hydrolase or the lack of a functional membrane protein, transporter, activator, or other protein. Lysosomal enzymes break down macromolecular compounds, which contribute to metabolic homeostasis. Stored, undegraded materials have multiple effects on cells that lead to the activation of autophagy and apoptosis, including the toxic effects of lyso-lipids, the disruption of intracellular Ca²⁺ ion homeostasis, the secondary storage of macromolecular compounds, the activation of signal transduction, apoptosis, inflammatory processes, deficiencies of intermediate compounds, and many other pathways. Clinical observations have shown that carriers of potentially pathogenic variants in LSD-associated genes and patients affected with some LSDs are at a higher risk of cancer, although the results of studies on the frequency of oncological diseases in LSD patients are controversial. Cancer is found in individuals affected with Gaucher disease, Fabry disease, Niemann-Pick type A and B diseases, alfa-mannosidosis, and sialidosis. Increased cancer prevalence has also been reported in carriers of a potentially pathogenic variant of an LSD gene, namely CLN3, SGSH, GUSB, NEU1, and, to a lesser extent, in other genes. In this review, LSDs in which oncological events can be observed are described. Full article

Background: Niemann-Pick disease type C (NPC) is an inherited disorder characterized by a functional deficiency of cholesterol transport proteins. However, the molecular mechanisms and pathophysiology of the disease remain unknown. Methods: In this study, we identified several metabolite characteristics of NPC that may fluctuate in a cellular model of the disease, using both global and targeted metabolomic analyses by liquid chromatography/tandem mass spectrometry (LC-MS/MS). Three cell lines, HepG2 cells (wild-type[WT]) and two NPC model HepG2 cell lines in which NPC1 was genetically ablated (knockout [KO]1 and KO2), were used for metabolomic analysis. Data were subjected to enrichment analysis using the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways. Results: The enrichment analysis of global metabolomics revealed that 8 pathways in KO1 and 16 pathways in KO2 cells were notably altered. In targeted metabolomics for 15 metabolites, 4 metabolites in KO1 and 10 metabolites in KO2 exhibited statistically significant quantitative changes in KO1 or KO2 relative to WT. Most of the altered metabolites were related to creatinine synthesis and cysteine metabolism pathways. Conclusions: In the future, our objective will be to elucidate the relationship between these metabolic alterations and pathophysiology. Full article

The productive replication of human immunodeficiency virus type 1 (HIV-1) involves intricate interactions between viral proteins and host cell machinery. However, the contributions of the lysosomal pathways for HIV-1 replication are not fully understood. The goal of this study was to determine the impact of lysosome-targeting compounds on HIV-1 replication and identify the cellular changes that are linked to HIV-1 inhibition using cell culture models of HIV-1 infection. Here, we demonstrate that the treatment of cells with various pharmacological agents known to inhibit lysosomal functions interfere with HIV-1 replication. The vacuolar ATPase (V-ATPase) inhibitor bafilomycin A1 exerted a potent inhibition of HIV-1 replication. Bafilomycin A1 inhibition of HIV-1 was independent of coreceptor tropism of HIV-1. Our data suggest that bafilomycin A1 inhibits HIV-1 at the post-integration steps of the virus life cycle, which include viral gene expression, virus assembly, and/or egress. Analysis of the cellular alterations following bafilomycin A1 treatment indicates that bafilomycin A1 causes a disruption in lysosome structure and functions. Treatment of cells with bafilomycin A1 caused an accumulation of unesterified cholesterol in lysosomes along with the expansion of the lysosomal compartments. Interestingly, the overexpression of the lysosomal cholesterol transporter Niemann–Pick type C 1 (NPC1) partially relieved bafilomycin A1 inhibition of HIV-1. Collectively, our data suggest that bafilomycin A1 inhibits HIV-1 replication in part by disrupting the lysosomal cholesterol trafficking pathway. Full article