Drug Repositioning for Fabry Disease: Acetylsalicylic Acid Potentiates the Stabilization of Lysosomal Alpha-Galactosidase by Pharmacological Chaperones

Identification of a novel nonsense mutation in α-galactosidase A that causes Fabry disease in a Chinese family

Fabry disease, a lysosomal storage disease, is an uncommon X-linked recessive genetic disorder stemming from abnormalities in the alpha-galactosidase gene (GLA) that codes human alpha-Galactosidase A (α-Gal A). To date, over 800 GLA mutations have been found to cause Fabry disease (FD). Continued enhancement of the GLA mutation spectrum will contribute to a deeper recognition and underlying mechanisms of FD. In this study, a 27-year-old male proband exhibited a typical phenotype of Fabry disease. Subsequently, family screening for Fabry disease was conducted, and high-throughput sequencing was employed to identify the mutated gene. The three-level structure of the mutated protein was analyzed, and its subcellular localization and enzymatic activity were determined. Apoptosis was assessed in GLA mutant cell lines to confirm the functional effects. As a result, a new mutation, c.777_778del (p. Gly261Leufs*3), in the GLA gene was identified. The mutation caused a frameshift during translation and the premature appearance of a termination codon, which led to a partial deletion of the domain in C-terminal region and altered the protein's tertiary structure. In vitro experiments revealed a significant reduction of the enzymatic activity in mutant cells. The expression was noticeably decreased at the mRNA and protein levels in mutant cell lines. Additionally, the subcellular localization of α-Gal A changed from a homogeneous distribution to punctate aggregation in the cytoplasm. GLA mutant cells exhibited significantly higher levels of apoptosis compared to wild-type cells.

Inflammatory and Cardiovascular Biomarkers to Monitor Fabry Disease Progression

Fabry disease is an invalidating multisystemic disorder affecting α-Galactosidase, a rate-limiting hydrolase dedicated to lipid catabolism. Non-metabolized substrates, such as Globotriaosylceramide and its derivatives trigger the direct or indirect activation of inflammatory events and endothelial dysfunction. In spite of the efficacy demonstrated by enzyme replacement therapy or pharmacological chaperones in delaying disease progression, few studies have analyzed whether these treatments can improve the pro-inflammatory state of FD patients. Therefore, the aim of this work was to assess cytokines and cardiovascular risk-related proteins detectable in plasma from FD patients, whether treated or not with ERT, to evaluate the reliability of these markers in monitoring disease stage and treatment effects. We identified inflammatory and endothelial dysfunction markers (ADAMTS-13, TNF-α, GDF-15, MIP-1β, VEGFA, MPO, and MIC-1) that cooperate in a common pathway and are increased in FD patients' plasma samples. As shown by the assessment of these proteins over time, they can help to evaluate the risk of higher severity in FD, as well as ERT effects. Even though the analyzed proteins cannot be considered as proper biomarkers due to their non-specificity to FD, taken together they can provide a signature of reference molecules with prognostic value for early diagnosis, and evaluation of disease progression and treatment efficacy, using blood samples.

DDCM: A Computational Strategy for Drug Repositioning Based on Support-Vector Regression Algorithm

Computational drug-repositioning technology is an effective tool for speeding up drug development. As biological data resources continue to grow, it becomes more important to find effective methods to identify potential therapeutic drugs for diseases. The effective use of valuable data has become a more rational and efficient approach to drug repositioning. The disease-drug correlation method (DDCM) proposed in this study is a novel approach that integrates data from multiple sources and different levels to predict potential treatments for diseases, utilizing support-vector regression (SVR). The DDCM approach resulted in potential therapeutic drugs for neoplasms and cardiovascular diseases by constructing a correlation hybrid matrix containing the respective similarities of drugs and diseases, implementing the SVR algorithm to predict the correlation scores, and undergoing a randomized perturbation and stepwise screening pipeline. Some potential therapeutic drugs were predicted by this approach. The potential therapeutic ability of these drugs has been well-validated in terms of the literature, function, drug target, and survival-essential genes. The method's feasibility was confirmed by comparing the predicted results with the classical method and conducting a co-drug analysis of the sub-branch. Our method challenges the conventional approach to studying disease-drug correlations and presents a fresh perspective for understanding the pathogenesis of diseases.

Drug Repurposing and Lysosomal Storage Disorders: A Trick to Treat

Rare diseases, or orphan diseases, are defined as diseases affecting a small number of people compared to the general population. Among these, we find lysosomal storage disorders (LSDs), a cluster of rare metabolic diseases characterized by enzyme mutations causing abnormal glycolipid storage. Drug repositioning involves repurposing existing approved drugs for new therapeutic applications, offering advantages in cost, time savings, and a lower risk of failure. We present a comprehensive analysis of existing drugs, their repurposing potential, and their clinical implications in the context of LSDs, highlighting the necessity of mutation-specific approaches. Our review systematically explores the landscape of drug repositioning as a means to enhance LSDs therapies. The findings advocate for the strategic repositioning of drugs, accentuating its role in expediting the discovery of effective treatments. We conclude that drug repurposing represents a viable pathway for accelerating therapeutic discovery for LSDs, emphasizing the need for the careful evaluation of drug efficacy and toxicity in disease-specific contexts.

Current trends and future prospects of drug repositioning in gastrointestinal oncology

Gastrointestinal (GI) cancers comprise a significant number of cancer cases worldwide and contribute to a high percentage of cancer-related deaths. To improve survival rates of GI cancer patients, it is important to find and implement more effective therapeutic strategies with better prognoses and fewer side effects. The development of new drugs can be a lengthy and expensive process, often involving clinical trials that may fail in the early stages. One strategy to address these challenges is drug repurposing (DR). Drug repurposing is a developmental strategy that involves using existing drugs approved for other diseases and leveraging their safety and pharmacological data to explore their potential use in treating different diseases. In this paper, we outline the existing therapeutic strategies and challenges associated with GI cancers and explore DR as a promising alternative approach. We have presented an extensive review of different DR methodologies, research efforts and examples of repurposed drugs within various GI cancer types, such as colorectal, pancreatic and liver cancers. Our aim is to provide a comprehensive overview of employing the DR approach in GI cancers to inform future research endeavors and clinical trials in this field.

Endothelial Cell Dysfunction and Hypoxia as Potential Mediators of Pain in Fabry Disease: A Human-Murine Translational Approach

Fabry disease (FD) is caused by α-galactosidase A (AGAL) enzyme deficiency, leading to globotriaosylceramide accumulation (Gb3) in several cell types. Pain is one of the pathophysiologically incompletely understood symptoms in FD patients. Previous data suggest an involvement of hypoxia and mitochondriopathy in FD pain development at dorsal root ganglion (DRG) level. Using immunofluorescence and quantitative real-time polymerase chain reaction (qRT PCR), we investigated patient-derived endothelial cells (EC) and DRG tissue of the GLA knockout (KO) mouse model of FD. We address the question of whether hypoxia and mitochondriopathy contribute to FD pain pathophysiology. In EC of FD patients (P1 with pain and, P2 without pain), we found dysregulated protein expression of hypoxia-inducible factors (HIF) 1a and HIF2 compared to the control EC (p < 0.01). The protein expression of the HIF downstream target vascular endothelial growth factor A (VEGFA, p < 0.01) was reduced and tube formation was hampered in the P1 EC compared to the healthy EC (p < 0.05). Tube formation ability was rescued by applying transforming growth factor beta (TGFβ) inhibitor SB-431542. Additionally, we found dysregulated mitochondrial fusion/fission characteristics in the P1 and P2 EC (p < 0.01) and depolarized mitochondrial membrane potential in P2 compared to control EC (p < 0.05). Complementary to human data, we found upregulated hypoxia-associated genes in the DRG of old GLA KO mice compared to WT DRG (p < 0.01). At protein level, nuclear HIF1a was higher in the DRG neurons of old GLA KO mice compared to WT mice (p < 0.01). Further, the HIF1a downstream target CA9 was upregulated in the DRG of old GLA KO mice compared to WT DRG (p < 0.01). Similar to human EC, we found a reduction in the vascular characteristics in GLA KO DRG compared to WT (p < 0.05). We demonstrate increased hypoxia, impaired vascular properties, and mitochondrial dysfunction in human FD EC and complementarily at the GLA KO mouse DRG level. Our data support the hypothesis that hypoxia and mitochondriopathy in FD EC and GLA KO DRG may contribute to FD pain development.

Congenital disorders of glycosylation: narration of a story through its patents

Congenital disorders of glycosylation are a group of more than 160 rare genetic defects in protein and lipid glycosylation. Since the first clinical report in 1980 of PMM2-CDG, the most common CDG worldwide, research made great strides, but nearly all of them are still missing a cure. CDG diagnosis has been at a rapid pace since the introduction of whole-exome/whole-genome sequencing as a diagnostic tool. Here, we retrace the history of CDG by analyzing all the patents associated with the topic. To this end, we explored the Espacenet database, extracted a list of patents, and then divided them into three major groups: (1) Drugs/therapeutic approaches for CDG, (2) Drug delivery tools for CDG, (3) Diagnostic tools for CDG. Despite the enormous scientific progress experienced in the last 30 years, diagnostic tools, drugs, and biomarkers are still urgently needed.

The Junctophilin-2 Mutation p.(Thr161Lys) Is Associated with Hypertrophic Cardiomyopathy Using Patient-Specific iPS Cardiomyocytes and Demonstrates Prolonged Action Potential and Increased Arrhythmogenicity

Hypertrophic cardiomyopathy (HCM) is one of the most common genetic cardiac diseases; it is primarily caused by mutations in sarcomeric genes. However, HCM is also associated with mutations in non-sarcomeric proteins and a Finnish founder mutation for HCM in non-sarcomeric protein junctophilin-2 (JPH2) has been identified. This study aimed at assessing the issue of modelling the rare Finnish founder mutation in cardiomyocytes (CMs) differentiated from iPSCs; therefore, presenting the same cardiac abnormalities observed in the patients. To explore the abnormal functions in JPH2-HCM, skin fibroblasts from a Finnish patient with JPH2 p.(Thr161Lys) were reprogrammed into iPSCs and further differentiated into CMs. As a control line, an isogenic counterpart was generated using the CRISPR/Cas9 genome editing method. Finally, iPSC-CMs were evaluated for the morphological and functional characteristics associated with JPH2 mutation. JPH2-hiPSC-CMs displayed key HCM hallmarks (cellular hypertrophy, multi-nucleation, sarcomeric disarray). Moreover, JPH2-hiPSC-CMs exhibit a higher degree of arrhythmia and longer action potential duration associated with slower inactivation of calcium channels. Functional evaluation supported clinical observations, with differences in beating characteristics when compared with isogenic-hiPSC-CMs. Thus, the iPSC-derived, disease-specific cardiomyocytes could serve as a translationally relevant platform to study genetic cardiac diseases.

An Innovative Tool for Evidence-Based, Personalized Treatment Trials in Mucopolysaccharidosis

Mucopolysaccharidosis (MPS) is a group of rare metabolic diseases associated with reduced life expectancy and a substantial unmet medical need. Immunomodulatory drugs could be a relevant treatment approach for MPS patients, although they are not licensed for this population. Therefore, we aim to provide evidence justifying fast access to innovative individual treatment trials (ITTs) with immunomodulators and a high-quality evaluation of drug effects by implementing a risk-benefit model for MPS. The iterative methodology of our developed decision analysis framework (DAF) consists of the following steps: (i) a comprehensive literature analysis on promising treatment targets and immunomodulators for MPS; (ii) a quantitative risk-benefit assessment (RBA) of selected molecules; and (iii) allocation phenotypic profiles and a quantitative assessment. These steps allow for the personalized use of the model and are in accordance with expert and patient representatives. The following four promising immunomodulators were identified: adalimumab, abatacept, anakinra, and cladribine. An improvement in mobility is most likely with adalimumab, while anakinra might be the treatment of choice for patients with neurocognitive involvement. Nevertheless, a RBA should always be completed on an individual basis. Our evidence-based DAF model for ITTs directly addresses the substantial unmet medical need in MPS and characterizes a first approach toward precision medicine with immunomodulatory drugs.

Rare Diseases: Implementation of Molecular Diagnosis, Pathogenesis Insights and Precision Medicine Treatment

Rare Diseases (RD) do not have an exact definition since local authorities define the criteria in different ways, from fewer than 5 people in 10,000, according to the European Union, to the standard world average of 40 cases per 100,000 people [...].

Long-Term Monitoring of Cardiac Involvement under Migalastat Treatment Using Magnetic Resonance Tomography in Fabry Disease

Background: Fabry cardiomyopathy is characterized by left ventricular hypertrophy, myocardial fibrosis, arrhythmia, and premature death. Treatment with migalastat, an oral pharmacological chaperone, was associated with a stabilization of cardiac biomarkers and a reduction in left ventricular mass index, as measured by echocardiography. A recent study, using cardiac magnetic resonance (CMR) as the gold standard, found a stable course of myocardial involvement after 18 months of treatment with migalastat. Our study aimed to provide long-term CMR data for the treatment with migalastat. Methods: A total of 11 females and four males with pathogenic amenable GLA mutations were treated with migalastat and underwent 1.5T CMR imaging for routine treatment effect monitoring. The main outcome was a long-term myocardial structural change, reflected by CMR. Results: After migalastat treatment initiation, left ventricular mass index, end diastolic volume, interventricular septal thickness, posterior wall thickness, estimated glomerular filtration rate, and plasma lyso-Gb3 remained stable during the median follow-up time of 34 months (min.: 25; max.: 47). The T1 relaxation times, reflecting glycosphingolipid accumulation and subsequent processes up to fibrosis, fluctuated over the time without a clear trend. No new onset of late gadolinium enhancement (LGE) areas, reflecting local fibrosis or scar formation of the myocardium, could be detected. However, patients with initially present LGE showed an increase in LGE as a percentage of left ventricular mass. The median α-galactosidase A enzymatic activity increased from 37.3% (IQR 5.88-89.3) to 105% (IQR 37.2-177) of the lower limit of the respective reference level (p = 0.005). Conclusion: Our study confirms an overall stable course of LVMi in patients with FD, treated with migalastat. However, individual patients may experience disease progression, especially those who present with fibrosis of the myocardium already at the time of therapy initiation. Thus, a regular treatment re-evaluation including CMR is needed to provide the optimal management for each patient.

Ursodeoxycholic Acid Binds PERK and Ameliorates Neurite Atrophy in a Cellular Model of GM2 Gangliosidosis

The Unfolded protein response (UPR), triggered by stress in the endoplasmic reticulum (ER), is a key driver of neurodegenerative diseases. GM2 gangliosidosis, which includes Tay-Sachs and Sandhoff disease, is caused by an accumulation of GM2, mainly in the brain, that leads to progressive neurodegeneration. Previously, we demonstrated in a cellular model of GM2 gangliosidosis that PERK, a UPR sensor, contributes to neuronal death. There is currently no approved treatment for these disorders. Chemical chaperones, such as ursodeoxycholic acid (UDCA), have been found to alleviate ER stress in cell and animal models. UDCA's ability to move across the blood-brain barrier makes it interesting as a therapeutic tool. Here, we found that UDCA significantly diminished the neurite atrophy induced by GM2 accumulation in primary neuron cultures. It also decreased the up-regulation of pro-apoptotic CHOP, a downstream PERK-signaling component. To explore its potential mechanisms of action, in vitro kinase assays and crosslinking experiments were performed with different variants of recombinant protein PERK, either in solution or in reconstituted liposomes. The results suggest a direct interaction between UDCA and the cytosolic domain of PERK, which promotes kinase phosphorylation and dimerization.

Enzyme Replacement Therapy for FABRY Disease: Possible Strategies to Improve Its Efficacy

Enzyme replacement therapy is the only therapeutic option for Fabry patients with completely absent AGAL activity. However, the treatment has side effects, is costly, and requires conspicuous amounts of recombinant human protein (rh-AGAL). Thus, its optimization would benefit patients and welfare/health services (i.e., society at large). In this brief report, we describe preliminary results paving the way for two possible approaches: i. the combination of enzyme replacement therapy with pharmacological chaperones; and ii. the identification of AGAL interactors as possible therapeutic targets on which to act. We first showed that galactose, a low-affinity pharmacological chaperone, can prolong AGAL half-life in patient-derived cells treated with rh-AGAL. Then, we analyzed the interactomes of intracellular AGAL on patient-derived AGAL-defective fibroblasts treated with the two rh-AGALs approved for therapeutic purposes and compared the obtained interactomes to the one associated with endogenously produced AGAL (data available as PXD039168 on ProteomeXchange). Common interactors were aggregated and screened for sensitivity to known drugs. Such an interactor-drug list represents a starting point to deeply screen approved drugs and identify those that can affect (positively or negatively) enzyme replacement therapy.

Curcumin Has Beneficial Effects on Lysosomal Alpha-Galactosidase: Potential Implications for the Cure of Fabry Disease

Fabry disease is a lysosomal storage disease caused by mutations in the GLA gene that encodes alpha-galactosidase (AGAL). The disease causes abnormal globotriaosylceramide (Gb3) storage in the lysosomes. Variants responsible for the genotypic spectrum of Fabry disease include mutations that abolish enzymatic activity and those that cause protein instability. The latter can be successfully treated with small molecules that either bind and stabilize AGAL or indirectly improve its cellular activity. This paper describes the first attempt to reposition curcumin, a nutraceutical, to treat Fabry disease. We tested the efficacy of curcumin in a cell model and found an improvement in AGAL activity for 80% of the tested mutant genotypes (four out of five tested). The fold-increase was dependent on the mutant and ranged from 1.4 to 2.2. We produced evidence that supports a co-chaperone role for curcumin when administered with AGAL pharmacological chaperones (1-deoxygalactonojirimycin and galactose). The combined treatment with curcumin and either pharmacological chaperone was beneficial for four out of five tested mutants and showed fold-increases ranging from 1.1 to 2.3 for DGJ and from 1.1 to 2.8 for galactose. Finally, we tested a long-term treatment on one mutant (L300F) and detected an improvement in Gb3 clearance and lysosomal markers (LAMP-1 and GAA). Altogether, our findings confirmed the necessity of personalized therapies for Fabry patients and paved the way to further studies and trials of treatments for Fabry disease.

Drug Repositioning Applied to Cardiovascular Disease in Mucopolysaccharidosis

Mucopolysaccharidoses (MPS) are genetic metabolic diseases characterized by defects in the activity of lysosomal hydrolases. In MPS, secondary cell disturbance affects pathways related to cardiovascular disorders. Hence, the study aimed to identify MPS-related drugs targeting cardiovascular disease and select a list of drugs for repositioning. We obtained a list of differentially expressed genes and pathways. To identify drug perturbation-driven gene expression and drug pathways interactions, we used the CMAP and LINCS databases. For molecular docking, we used the DockThor web server. Our results suggest that pirfenidone and colchicine are promising drugs to treat cardiovascular disease in MPS patients. We also provide a brief description of good practices for the repositioning analysis. Furthermore, the list of drugs and related MPS-enriched genes could be helpful to new treatments and considered for pathophysiological studies.