Search Results (122)

Background/Objectives: Gaucher disease (GD) is an autosomal recessive lysosomal storage disorder caused by mutations in the GBA1 gene. Type 1 Gaucher disease is characterised by substrate accumulation in the visceral organs, which occurs in combination with acute and chronic neurodegeneration that distinguish type 2 and type 3 GD, respectively. We have previously shown the efficacy of neonatal AAV9 gene therapy for treating type 2 GD and aimed to investigate post-symptomatic administration into a model of type 1 disease. Current murine models of type 1 disease are limited in their recapitulation of early onset phenotypic manifestation and thus we aimed to create a novel model of type 1 in which to test the efficacy of adult gene therapy. Methods: The novel AAV-GD1 model was created through intracerebroventricular injection of AAV9 containing the human GBA1 gene under control of the neuron-specific synapsin promoter (AAV9.hSynI.hGBA1) to the pre-existing acute K14-lnl/lnl model of type 2 GD. Administration of AAV9.hSynI.hGBA1 aimed to restore glucocerebrosidase expression in the brain and extend the lifespan beyond 14 days, allowing the visceral pathology to develop further. The organ pathology was characterised by immunohistochemistry at various time points. Once visceral disease was confirmed, an intravenous injection of AAV9 containing a ubiquitously active CAG promoter driving hGBA1 (AAV9.CAG.hGBA1) was administered to post-symptomatic mice. Animals were aged for 2 and 4 months post-treatment with AAV9.CAG.hGBA1, and immunohistochemistry and enzymatic activity were assessed to investigate therapeutic efficacy. Results: The AAV-GD1 model displayed visceral pathology in the spleen, lung, and liver from 2 months of age. This allowed us to validate the efficacy of adult gene therapy; intravenous administration of AAV9.CAG.hGBA1 transiently ameliorated the lung pathology and rescued the spleen pathology up to 4 months post-administration. Conclusions: The creation of the novel AAV-GD1 model with more aggressive visceral pathology presents a unique opportunity for investigation of new therapies to treat type 1 GD. AAV9.CAG.hGBA1 represents a potential therapeutic option for all forms of Gaucher disease. Full article

Gaucher disease is an autosomal recessive disorder caused by dysfunction of the enzyme glucocerebrosidase. The enzyme deficiency is mainly due to mutations in the GBA1 gene, and it is responsible for the accumulation of glucosylceramide within the lysosomes of monocyte macrophage-derived cells; causing the associated symptomatology. In this paper, we describe six new mutations identified in the GBA1 gene, which, in combination with other mutations already documented, lead to absent or reduced glucocerebrosidase activity, resulting in pathological accumulation of the specific substrate and the clinical manifestations associated with Gaucher disease. We have identified three mutations (c.1578_1581dup, c.1308dup, and Y492X) that determine the formation of a premature stop codon in the translation process and three missense mutations (C342F, M280L, and Q247R) that lead to amino acid changes in proteins, resulting in decreased glucocerebrosidase activity. These mutations were never observed in our group of healthy control subjects > 1500 individuals. The patients examined had several clinical manifestations, which included hepatosplenomegaly and bone and hematologic involvement; considering the absence of enzyme activity, this suggests that the new mutations described here are associated with type I Gaucher disease. The identification of new mutations in patients with symptoms referable to Gaucher disease increases the molecular knowledge related to the GBA1 gene and offers to clinicians significant support for the accurate diagnosis of the pathology. Full article

Sidransky syndrome represents a distinct variant of Parkinson’s disease (PD) that is linked to pathogenic variants in the glucocerebrosidase (GBA1) gene. This disorder exhibits an earlier onset, a more severe course, and a higher dementia prevalence compared to idiopathic PD. While the pathogenesis remains debated between loss-of-function and gain-of-function mechanisms, targeted therapies are emerging. Pharmacological chaperones (PCs), like high-dose Ambroxol, aim to mitigate enzyme misfolding—a primary driver of this disorder—rather than addressing metabolic deficiencies seen in Gaucher disease. Despite failed trials of substrate reduction therapies, current clinical trials with Ambroxol and other PCs highlight promising avenues for disease modification. This commentary advocates for increased awareness of Sidransky syndrome to advance diagnostic strategies, promote genetic testing, and refine targeted treatments, with the potential to transform care for GBA1-related PD and prodromal stages of the disease. Full article

Introduction: The differential diagnosis of splenomegaly is a complex process that encompasses a wide variety of diseases. Moreover, it is not always standardized and lacks a definitive consensus on which tests should be performed and in what order. Gaucher disease (GD) and acid sphingomyelinase deficiency (ASMD) are lysosomal diseases (LD) that present with splenomegaly, the diagnosis of which requires a high index of suspicion and specific biochemical and genetic techniques. The aim of the project for the education and diagnosis of Gaucher disease and acid sphingomyelinase deficiency (PREDIGA) was to conduct educational training alongside an observational, multicenter, ambispective, cross-sectional, single-cohort study among patients having an enlarged spleen or undergone splenectomy to further assess these subjects to exclude two lysosomal diseases, namely GD and ASMD. Methods: Using dried blood spot (DBS) testing, we identified patients with abnormally low values of the enzymes glucocerebrosidase and acid sphingomyelinase, who then underwent sequencing of the GBA1 and SPMD1 genes, respectively. The study involved 34 hospitals and 52 medical specialists. Results: We identified 220 patients (208 adults and 12 children under 18 years) with cryptogenic splenomegaly or who had undergone splenectomy (12 patients) without having reached a diagnosis. The median age was 11 years (interquartile range [IQR] 3–16) in the pediatric population and 51 years (IQR 38–65) in the adult population. Lower-than-normal enzyme values were detected in 19 DBSs, confirming eight positive cases, which corresponded to six patients with GD and two with ASMD. The rest of the DBSs with low enzyme activity were not genetically confirmed (58%). We determined that lysosomal diseases accounted for 3.6% of cryptogenic splenomegaly/splenectomy cases in our setting: 2.7% were GD and 0.9% ASMD, in a ratio of 1 ASMD patient to every 3 GD patients. Lyso-GL1 values in patients with GD were elevated in all but one individual, corresponding to a child diagnosed at 4 months old. The variants detected in the GBA1 gene were consistent with the most frequent variants found in Spain. Discussion/Conclusion: The development and implementation of this protocol for the education and diagnosis of cryptogenic splenomegaly/splenectomy, even in asymptomatic patients, constitutes a comprehensive, simple, rapid, and effective screening method for the diagnosis of GD and ASMD. Full article

Macrophages are specialised cells that degrade a range of substrates during their lifetime. In inherited lysosomal storage disorders, particularly the sphingolipidoses, macrophages transform into storage cells and contribute to pathology. An appropriate cultured macrophage model is desired for fundamental research and the assessment of considered therapeutic interventions. We compared commonly used macrophage cell lines, RAW264.7, J774A.1, and THP-1 cells, with human monocyte-derived macrophages (HMDMs) isolated from peripheral blood. Specific lysosomal glucosidases were analysed by enzymatic activity measurements and visualised with fluorescent activity-based probes. Special attention was given to lysosomal glucocerebrosidase (GBA1), the enzyme deficient in Gaucher disease in which lipid-laden macrophages are a hallmark. In macrophage cell lines and HMDMs, various (glyco)sphingolipids relevant to GBA1 activity were determined. Finally, the feasibility of inactivation of GBA1 with a cell-permeable suicide inhibitor was established, as well as the monitoring of uptake of therapeutic recombinant human GBA1. Major differences among various cell lines were noted in terms of morphology, lysosomal enzyme expression, and glycosphingolipid content. HMDMs appear to be the most suitable model for investigations into GBA1 and Gaucher disease. Moreover, they serve as a valuable model for mannose-receptor mediated uptake of therapeutic human GBA1, effectively mimicking enzyme replacement therapy for Gaucher disease. Full article

Background: Gaucher disease (GD) is a rare autosomal recessive lysosomal storage disorder caused by mutations in the GBA1 gene, leading to deficient β-glucocerebrosidase activity. This results in the accumulation of glucocerebroside in macrophages, primarily affecting the liver, spleen, bone marrow, and bones. Understanding the clinical outcomes and genetic mutation profiles in specific populations, such as Turkish patients, is essential for optimized disease management and personalized therapy and preventing morbidity and mortality. Method: This retrospective study analyzed data from 29 Turkish patients with previously diagnosed type 1 GD at a single center between September and December 2023. Genetic analyses were performed to identify GBA1 mutations using next-generation sequencing. Genetic mutations were the primary criterion for diagnosing GD. Clinical features, treatment responses, and outcomes were evaluated. Clinical parameters included hematological findings, organomegaly, and bone involvement. Data were analyzed to identify potential correlations between genetic mutations and clinical manifestations. Results: This study included 14 male and 15 female patients, with a mean diagnosis age of 22.1 years. A significant family history was observed in 93% of cases, and 52% had consanguineous parents. Epistaxis (72%) was the most common pre-diagnosis symptom. Most patients received enzyme replacement therapy with 60 units/kg. Treatment led to significant improvements, including increased hemoglobin (21.1%), higher platelet count (86.1%), and reduced organomegaly (liver (10.02%), spleen (25.22%)). Genetic analysis identified seven mutations, with c.1226A>G (p.N409S) being the most frequent. Conclusions: This study highlights the spectrum of clinical outcomes and genetic mutations in Turkish patients with GD, emphasizing the variability in disease severity based on genotype. GD should be considered for patients with unexplained nosebleeds, hepatosplenomegaly, bone pain, weakness, or siblings or other family members with similar symptoms. The genetic analysis revealed considerable heterogeneity among patients, which indicates the necessity of observing this in the development of personalized treatment strategies. Future studies with larger cohorts and long-term follow-up are needed to further elucidate genotype–phenotype correlations in this population. Full article

Preimplantation genetic testing (PGT) is practiced worldwide, allowing the prevention of the transmission and expression of various genetic conditions. Socio-ethical considerations of justified applications for PGT are part of an ongoing debate. Pathogenic variants in the glucocerebrosidase (GBA1) gene, causing Gaucher disease (GD), have emerged as a risk factor for Parkinson’s disease (PD) in both patients and carriers. Genotype–phenotype correlations exist between different GBA1 pathogenic variants and the risk to develop PD: mild pathogenic variants increase the risk of developing PD by ~3-fold, while severe pathogenic variants increase this risk by ~15-fold, occurring at a younger age. A woman with GD, a compound heterozygote of N370S (now commonly described as c.1226A>G (N409S)—mild pathogenic variant) and 84insG (severe pathogenic variant), had PGT consulting before planned in vitro-fertilization. Her mother, an 84insG carrier, had early-onset PD. GBA1 sequencing of her spouse was negative. We discussed the selection for N370S carrier embryos to reduce PD risk. This case report demonstrates the expansion of PGT for late-onset conditions. These novel indications will increase the number of subjects who would be candidates for PGT. The medical and bioethical considerations of these cases should be acknowledged by the professional community and discussed with couples during genetic counseling. Full article

Parkinson’s disease (PD) is the second most common neurodegenerative disease in the world. Currently, PD is incurable, and the diagnosis of PD mainly relies on clinical manifestations. The central pathological event in PD is the abnormal aggregation and deposition of misfolded α-synuclein (α-Syn) protein aggregates in the Lewy body (LB) in affected brain areas. Behaving as a prion-like seeding, the misfolded α-syn protein can induce and facilitate the aggregation of native unfolded α-Syn protein to aggravate α-Syn protein aggregation, leading to PD progression. Recently, in a blood-based α-Syn seeding amplification assay (SAA), Kluge et al. identified pathological α-Syn seeding activity in PD patients with Parkin (PRKN) gene variants. Additionally, pathological α-syn seeding activity was also identified in sporadic PD and PD patients with Leucine-rich repeat kinase 2 (LRRK2) or glucocerebrosidase (GBA) gene variants. Principally, the α-Syn SAA can be used to detect pathological α-Syn seeding activity, which will significantly enhance PD diagnosis, progression monitoring, prognosis prediction, and anti-PD therapy. The significance and future strategies of α-Syn SAA protocol are highlighted and proposed, whereas challenges and limitations of the assay are discussed. Full article

Mutations in the GBA1 gene, which encodes the lysosomal enzyme glucocerebrosidase (GCase), are associated with Gaucher disease and increased risk of Parkinson’s disease. This study describes the discovery and characterization of novel allosteric pharmacological chaperones for GCase through an innovative computational approach combined with experimental validation. Utilizing virtual screening and structure-activity relationship optimization, researchers identified several compounds that significantly enhance GCase activity and stability across various cellular models, including patient-derived fibroblasts and neuronal cells harboring GBA1 mutations. Among these, compound 3 emerged as a lead candidate, demonstrating the ability to enhance GCase protein levels and enzymatic activity while effectively reducing the accumulation of toxic substrates in neuronal models. Importantly, pharmacokinetic studies revealed that compound 3 has favorable brain penetration, indicating its potential as a disease-modifying therapy for GBA1-related disorders affecting the central nervous system. This research not only offers a framework for developing allosteric GCase modulators but also unveils promising new therapeutic strategies for managing Gaucher disease and Parkinson’s disease. The ability of compound 3 to cross the blood-brain barrier emphasizes its potential significance in addressing neurological symptoms associated with these conditions. Full article

Background: Gaucher disease (GD) is a rare autosomal recessive disorder caused by mutations in the GBA1 gene that lead to a deficiency in the glucocerebrosidase gene. This deficiency results in the accumulation of glucocerebrosides in macrophages, primarily affecting the liver, spleen, and bone marrow. Focusing on the Mexican population, this study aims to review GD’s epidemiology, clinical manifestations, and treatment options to enhance early diagnosis and optimize treatment outcomes. Methods: This study is a comprehensive literature review analyzing epidemiological data, clinical presentations, and current therapeutic approaches for Gaucher disease, including enzyme replacement therapy (ERT) and substrate reduction therapy (SRT). Conclusions: Early diagnosis and individualized treatment, primarily through enzyme replacement therapy, significantly improve the prognosis of patients with Gaucher disease, particularly type 1. Continued research is required to enhance therapeutic approaches for the neuropathic types and better understand the disease’s epidemiology in Mexico. These efforts will contribute to improved clinical outcomes and quality of life for patients. Full article

Parkinson’s disease (PD) is considered to be the second most prominent neurodegenerative disease and has a global prevalence. Glucocerebrosidase (GBA1) gene mutations represent a significant hereditary risk factor for the development of PD and have a profound impact on the motor and cognitive progression of the disease. The aim of this review is to summarize the literature data on the prevalence, type, and peculiarities of GBA1 mutations in populations of different ethnic backgrounds. We reviewed articles spanning the 2000–2024 period. GBA1-related PD has a worldwide distribution. It has long been recognized that pathogenic GBA1 mutations are particularly common in certain ethnic populations, including PD patients of Ashkenazi Jewish ancestry. Moreover, a considerable number of studies focused on European ancestry patients from Europe and North America have revealed a high proportion (up to 15%) of carriers among the PD population. GBA1 mutations also appear to play an important role in patient groups with an East Asian background, although the frequency of specific variants may differ as compared to those of European ancestry. Notably, the assessment of underrepresented populations in other parts of Asia (including India) and Latin America is in the spotlight of current research, while a variant with a newly described pathogenic mechanism has been reported in Sub-Saharan Africans. Given the importance of GBA1 mutations for PD genetics and clinical phenotype, a focused assessment of the prevalence and type of GBA1 variants in distinct ethnic populations will possibly inform ongoing PD-related clinical studies and facilitate upcoming therapeutic trials. Full article

Dementia with Lewy bodies (DLB) is a progressive neurodegenerative disorder marked by the accumulation of α-synuclein (αSyn), often co-existing with amyloid β (Aβ) pathology. Current treatments are largely symptomatic, highlighting a critical need for disease-modifying therapies. Evidence suggests that αSyn aggregates contribute to neuronal death in DLB, particularly when exacerbated by Aβ. Given the role of autophagy in clearing misfolded proteins, exploring agents that promote this pathway is essential for developing effective treatments. Ambroxol (AMBX), a mucolytic drug, has demonstrated potential in activating glucocerebrosidase (GCase), an enzyme that enhances lysosomal function and facilitates the autophagic clearance of toxic protein aggregates, including αSyn. This study aims to evaluate AMBX’s neuroprotective effects in a cellular model of DLB, with the goal of identifying new therapeutic agents that target the underlying pathology of DLB. In this study, HT-22 hippocampal neuronal cells were exposed to αSyn and Aβ, followed by AMBX treatment. Our results showed that AMBX significantly improved cell viability and reduced apoptosis in cells co-treated with αSyn and Aβ. Additionally, AMBX restored GCase activity, promoted autophagy, and reduced oxidative stress, which in turn mitigated αSyn aggregation and phosphorylation. These findings suggest that by activating GCase and enhancing autophagy, AMBX may help alleviate DLB-associated neurodegeneration. This study underscores the potential of AMBX as a therapeutic agent for DLB and supports further investigation in animal models and clinical trials to validate its efficacy in neurodegenerative disease contexts. Full article

Gaucher disease (GD) is a lysosomal lipid storage disorder caused by β-glucocerebrosidase (encoded by GBA1 gene) activity deficiency, resulting in the accumulation of glucosylceramide (Gb1) and its deacylated metabolite glucosylsphingosine (lyso-Gb1). Lyso-Gb1 has been studied previously and proved to be a sensitive biomarker, distinguishing patients with GD from carriers and healthy subjects. It was shown that its level corresponds with β-glucocerebrosidase activity, thus it remains unknown as to why carriers have slightly higher lyso-Gb1 level than healthy population. This is the first report on lyso-Gb1 levels describing representative cohort of GD carriers. Our data of 48 GD carriers, including three newborns, indicated that there are significant differences in lyso-Gb1 levels between carriers having a GD-affected mother and a healthy mother (11.53 and 8.45, respectively, p = 0.00077), and between carriers of the L483P GBA1 variant and carriers of other GBA1 pathogenic variants (9.85 and 7.03, respectively, p = 0.07). Through analysing our unique data of three newborns whose mothers are patients with GD, we also found that lyso-Gb1 is most probably transferred to the foetus via placenta. Full article

Heterozygous mutations or genetic variants in the GBA1 gene, which encodes for the β-glucocerebrosidase (GCase), a lysosomal hydrolase enzyme, may increase the risk of Parkinson’s disease (PD) onset. The heterozygous E326K form is one of the most common genetic risk factors for PD worldwide, but, to date, the underlying molecular mechanisms remain unclear. Here, we investigate the effect of the E326K on the structure, stability, dimerization process, and interaction mode with some proteins of the interactome of GCase using multiple molecular dynamics (MD) simulations at pH 5.5 and pH 7.0 to mimic the lysosomal and endoplasmic reticulum environments, respectively. The analysis of the MD trajectories highlights that the E326K mutation did not significantly alter the structural conformation of the catalytic dyad but significantly makes the structure of the dimeric complexes unstable, especially at lysosomal pH, potentially impacting the organization of the quaternary structure. Furthermore, the E326K mutation significantly impacts protein interactions by altering the binding mode with the activator Saposin C (SapC), reducing the binding affinity with the inhibitor α-Synuclein (α-Syn), and increasing the affinity for the Lysosomal integral membrane protein-2 (LIMP-2) transporter. Full article

The human GBA1 gene encodes lysosomal acid β-glucocerebrosidase, whose activity is deficient in Gaucher disease (GD). In Drosophila, there are two GBA1 orthologs, Gba1a and Gba1b, and Gba1b is the bona fide GCase encoding gene. Several fly lines with different deletions in the Gba1b were studied in the past. However, since most GD-associated GBA1 mutations are point mutations, we created missense mutations homologous to the two most common GD mutations: the mild N370S mutation (D415S in Drosophila) and the severe L444P mutation (L494P in Drosophila), using the CRISPR-Cas9 technology. Flies homozygous for the D415S mutation (dubbed D370S hereafter) presented low GCase activity and substrate accumulation, which led to lysosomal defects, activation of the Unfolded Protein Response (UPR), inflammation/neuroinflammation, and neurodegeneration along with earlier death compared to control flies. Surprisingly, the L494P (called L444P hereafter) flies presented higher GCase activity with fewer lysosomal defects and milder disease in comparison to that presented by the D370S homozygous flies. Treatment with ambroxol had a limited effect on all homozygous fly lines tested. Overall, our results underscore the differences between the fly and human GCase enzymes, as evidenced by the distinct phenotypic outcomes of mutations in flies compared to those observed in human GD patients. Full article