Inhibition of Soluble Epoxide Hydrolase Ameliorates Phenotype and Cognitive Abilities in a Murine Model of Niemann Pick Type C Disease.

Niemann-Pick type C (NPC) disease is a rare autosomal recessive inherited childhood neurodegenerative disease characterized by the accumulation of cholesterol and glycosphingolipids, involving the autophagy-lysosome system. Inhibition of soluble epoxide hydrolase (sEH), an enzyme that metabolizes epoxy fatty acids (EpFAs) to 12-diols, exerts beneficial effects in modulating inflammation and autophagy, critical features of the NPC disease. This study aims to evaluate the effects of UB-EV-52, an sEH inhibitor (sEHi), in an NPC mouse model (Npc) by administering it for 4 weeks (5 mg/kg/day). Behavioral and cognitive tests (open-field test (OF)), elevated plus maze (EPM), novel object recognition test (NORT) and object location test (OLT) demonstrated that the treatment produced an improvement in short- and long-term memory as well as in spatial memory. Furthermore, UB-EV-52 treatment increased body weight and lifespan by 25% and reduced gene expression of the inflammatory markers (i.e., Il-1ß and Mcp1) and enhanced oxidative stress (OS) markers (iNOS and Hmox1) in the treated Npc mice group. As for autophagic markers, surprisingly, we found significantly reduced levels of LC3B-II/LC3B-I ratio and significantly reduced brain protein levels of lysosomal-associated membrane protein-1 (LAMP-1) in treated Npc mice group compared to untreated ones in hippocampal tissue. Lipid profile analysis showed a significant reduction of lipid storage in the liver and some slight changes in homogenated brain tissue in the treated NPC mice compared to the untreated groups. Therefore, our results suggest that pharmacological inhibition of sEH ameliorates most of the characteristic features of NPC mice, demonstrating that sEH can be considered a potential therapeutic target for this disease.

Mutational spectrum by phenotype: panel-based NGS testing of patients with clinical suspicion of RASopathy and children with multiple café-au-lait macules.

Children with neurofibromatosis type 1 (NF1) may exhibit an incomplete clinical presentation, making difficult to reach a clinical diagnosis. A phenotypic overlap may exist in children with other RASopathies or with other genetic conditions if only multiple café-au-lait macules (CALMs) are present. The syndromes that can converge in these inconclusive phenotypes have different clinical courses. In this context, an early genetic testing has been proposed to be clinically useful to manage these patients. We present the validation and implementation into diagnostics of a custom NGS panel (I2HCP, ICO-IMPPC Hereditary Cancer Panel) for testing patients with a clinical suspicion of a RASopathy (n = 48) and children presenting multiple CALMs (n = 102). We describe the mutational spectrum and the detection rates identified in these two groups of individuals. We identified pathogenic variants in 21 out of 48 patients with clinical suspicion of RASopathy, with mutations in NF1 accounting for 10% of cases. Furthermore, we identified pathogenic mutations mainly in the NF1 gene, but also in SPRED1, in more than 50% of children with multiple CALMs, exhibiting an NF1 mutational spectrum different from a group of clinically diagnosed NF1 patients (n = 80). An NGS panel strategy for the genetic testing of these two phenotype-defined groups outperforms previous strategies.

Bone development and remodeling in metabolic disorders.

There are many metabolic disorders that present with bone phenotypes. In some cases, the pathological bone symptoms are the main features of the disease whereas in others they are a secondary characteristic. In general, the generation of the bone problems in these disorders is not well understood and the therapeutic options for them are scarce. Bone development occurs in the early stages of embryonic development where the bone formation, or osteogenesis, takes place. This osteogenesis can be produced through the direct transformation of the pre-existing mesenchymal cells into bone tissue (intramembranous ossification) or by the replacement of the cartilage by bone (endochondral ossification). In contrast, bone remodeling takes place during the bone's growth, after the bone development, and continues throughout the whole life. The remodeling involves the removal of mineralized bone by osteoclasts followed by the formation of bone matrix by the osteoblasts, which subsequently becomes mineralized. In some metabolic diseases, bone pathological features are associated with bone development problems but in others they are associated with bone remodeling. Here, we describe three examples of impaired bone development or remodeling in metabolic diseases, including work by others and the results from our research. In particular, we will focus on hereditary multiple exostosis (or osteochondromatosis), Gaucher disease, and the susceptibility to atypical femoral fracture in patients treated with bisphosphonates for several years.

Sanfilippo Syndrome: Molecular Basis, Disease Models and Therapeutic Approaches.

Sanfilippo syndrome or mucopolysaccharidosis III is a lysosomal storage disorder caused by mutations in genes responsible for the degradation of heparan sulfate, a glycosaminoglycan located in the extracellular membrane. Undegraded heparan sulfate molecules accumulate within lysosomes leading to cellular dysfunction and pathology in several organs, with severe central nervous system degeneration as the main phenotypical feature. The exact molecular and cellular mechanisms by which impaired degradation and storage lead to cellular dysfunction and neuronal degeneration are still not fully understood. Here, we compile the knowledge on this issue and review all available animal and cellular models that can be used to contribute to increase our understanding of Sanfilippo syndrome disease mechanisms. Moreover, we provide an update in advances regarding the different and most successful therapeutic approaches that are currently under study to treat Sanfilippo syndrome patients and discuss the potential of new tools such as induced pluripotent stem cells to be used for disease modeling and therapy development.

Correction: Stereodivergent synthesis of right- and left-handed iminoxylitol heterodimers and monomers. Study of their impact on ß-glucocerebrosidase activity.

Correction for 'Stereodivergent synthesis of right- and left-handed iminoxylitol heterodimers and monomers. Study of their impact on ß-glucocerebrosidase activity' by Fabien Stauffert et al., Org. Biomol. Chem., 2017, 15, 3681-3705.

Stereodivergent synthesis of right- and left-handed iminoxylitol heterodimers and monomers. Study of their impact on ß-glucocerebrosidase activity.

A library of dimers and heterodimers of both enantiomers of 2-O-alkylated iminoxylitol derivatives has been synthesised and evaluated on ß-glucocerebrosidase (GCase), the enzyme responsible for Gaucher disease (GD). Although the objective was to target simultaneously the active site and a secondary binding site of the glucosidase, the (-)-2-iminoxylitol moiety seemed detrimental for imiglucerase inhibition and no significant enhancement was obtained in G202R, N370S and L444P fibroblasts. However, all compounds having at least one (+)-2-O-alkyl iminoxylitol are GCase inhibitors in the nano molar range and are significant GCase activity enhancers in G202R fibroblats, as confirmed by a decrease of glucosylceramide levels and by co-localization studies.

Screening of CD96 and ASXL1 in 11 patients with Opitz C or Bohring-Opitz syndromes.

Opitz C trigonocephaly (or Opitz C syndrome, OTCS) and Bohring-Opitz syndrome (BOS or C-like syndrome) are two rare genetic disorders with phenotypic overlap. The genetic causes of these diseases are not understood. However, two genes have been associated with OTCS or BOS with dominantly inherited de novo mutations. Whereas CD96 has been related to OTCS (one case) and to BOS (one case), ASXL1 has been related to BOS only (several cases). In this study we analyze CD96 and ASXL1 in a group of 11 affected individuals, including 2 sibs, 10 of them were diagnosed with OTCS, and one had a BOS phenotype. Exome sequences were available on six patients with OTCS and three parent pairs. Thus, we could analyze the CD96 and ASXL1 sequences in these patients bioinformatically. Sanger sequencing of all exons of CD96 and ASXL1 was carried out in the remaining patients. Detailed scrutiny of the sequences and assessment of variants allowed us to exclude putative pathogenic and private mutations in all but one of the patients. In this patient (with BOS) we identified a de novo mutation in ASXL1 (c.2100dupT). By nature and location within the gene, this mutation resembles those previously described in other BOS patients and we conclude that it may be responsible for the condition. Our results indicate that in 10 of 11, the disease (OTCS or BOS) cannot be explained by small changes in CD96 or ASXL1. However, the cohort is too small to make generalizations about the genetic etiology of these diseases.

Characterisation of two deletions involving NPC1 and flanking genes in Niemann-Pick type C disease patients.

Niemann-Pick type C (NPC) disease is an autosomal recessive lysosomal disorder characterised by the accumulation of a complex pattern of lipids in the lysosomal-late endosomal system. More than 300 disease-causing mutations have been identified so far in the NPC1 and NPC2 genes, including indel, missense, nonsense and splicing mutations. Only one genomic deletion, of more than 23 kb, has been previously reported. We describe two larger structural variants, encompassing NPC1 and flanking genes, as a cause of the disease. QMPSF, SNP inheritance and CytoScan® HD Array were used to confirm and further characterise the presence of hemizygous deletions in two patients. One of the patients (NPC-57) bore a previously described missense mutation (p.T1066N) and an inherited deletion that included NPC1, C18orf8 and part of ANKRD29 gene. The second patient (NPC-G1) had a 1-bp deletion (c.852delT; p.F284Lfs*26) and a deletion encompassing the promoter region and exons 1-10 of NPC1 and the adjacent ANKRD29 and LAMA3. This study characterised two novel chromosomal microdeletions at 18q11-q12 that cause NPC disease and provide insight into missing NPC1 mutant alleles.

Glucocerebrosidase mutations confer a greater risk of dementia during Parkinson's disease course.

Mutations in the glucocerebrosidase gene are associated with Parkinson's disease and Lewy body dementia. However, whether these alterations have any effect on the clinical course of Parkinson's disease is not clear. The glucocerebrosidase coding region was fully sequenced in 225 Parkinson's disease patients, 17 pathologically confirmed Lewy body dementia patients, and 186 controls from Spain. Twenty-two Parkinson's disease patients (9.8%) and 2 Lewy body dementia patients (11.8%) carried mutations in the glucocerebrosidase gene, compared with only 1 control (0.5%); P = .016 and P = .021 for Parkinson's disease and Lewy body dementia, respectively. The N370S and the L444P mutations represented 50% of the alterations. Two novel variants, L144V and S488T, and 7 previously described alterations were also found. Alterations in glucocerebrosidase were associated with a significant risk of dementia during the clinical course of Parkinson's disease (age at onset, years of evolution, and sex-adjusted odds ratio, 5.8; P = .001). Mutation carriers did not show worse motor symptoms, had good response to L-dopa, and tended to present the intermediate parkinsonian phenotype. Our findings suggest that mutations in the glucocerebrosidase gene not only increase the risk of both Parkinson's disease and Lewy body dementia but also strongly influence the course of Parkinson's disease with respect to the appearance of dementia.

Genome Editing Using Cas9-gRNA Ribonucleoprotein in Human Pluripotent Stem Cells for Disease Modeling.

The discovery that the CRISPR/Cas9 system could be used for genome editing purposes represented a major breakthrough in the field. This advancement has notably facilitated the introduction or correction of disease-specific mutations in healthy or disease stem cell lines respectively; therefore, easing disease modeling studies in combination with differentiation protocols. For many years, variability in the genetic background of different stem cell lines has been a major burden to specifically identify phenotypes arising uniquely from the presence of the mutation and not from differences in other genomic regions.Here, we provide a complete protocol to introduce random indels in human wild type pluripotent stem cells using CRISPR/Cas9 in order to generate clonal lines with potential pathogenic alterations in any gene of interest. In this protocol, we use transfection of a ribonucleoprotein complex to diminish the risk of off-target effects, and select clonal lines with promising indels to obtain disease induced pluripotent stem cell lines.

Fifteen years of enzyme replacement therapy for mucopolysaccharidosis type VI (Maroteaux-Lamy syndrome): a case report.

BACKGROUND: Mucopolysaccharidosis VI, or Maroteaux-Lamy disease, is an autosomal recessive disease characterized by deficiency of the enzyme arylsulfatase B in the lysosomal catabolism of glycosaminoglycans. Due to reduced (or even null) enzyme activity, glycosaminoglycans (mainly dermatan sulfate) accumulates, leading to a multisystemic disease. Mucopolysaccharidosis VI induces reduced growth, coarse face, audiovisual deficits, osteoarticular deformities, and cardiorespiratory issues, hampering the quality of life of the patient. Enzyme replacement therapy with galsulfase (Naglazyme, BioMarin Pharmaceuticals Inc., USA) is the specific treatment for this condition. Although studies have shown that enzyme replacement therapy slows the progression of the disease, the effects of long-term enzyme replacement therapy remain poorly understood. CASE PRESENTATION: A 29-year-old, Caucasian, male patient diagnosed with mucopolysaccharidosis VI was treated with enzyme replacement therapy for over 15 years. Enzyme replacement therapy was initiated when patient was 13 years old. The patient evolved multiplex dysostosis, carpal tunnel syndrome, thickened mitral valve, and hearing and visual loss. CONCLUSIONS: Although enzyme replacement therapy did not prevent the main signs of mucopolysaccharidosis VI, it slowed their progression. Additionally, enzyme replacement therapy was associated with a longer survival compared with the untreated affected sibling. Taken together, the results indicate that enzyme replacement therapy positively modified the course of the disease.

Molecular characterization of a new deletion of the GBA1 gene due to an inter Alu recombination event.

Gaucher disease is the most frequent lysosomal storage disorder due to the autosomal recessive deficiency of acid ß-glucosidase. More than 300 mutations in the GBA1 gene have been described. However only one large deletion of the GBA1 gene has been reported to date. Here, using a combination of different experimental approaches including PCR, sequencing and Southern blot analysis, we describe the identification and characterization of a new large deletion of the GBA1 gene due to an inter Alu recombination event.

ß-Glucocerebrosidase gene mutations in two cohorts of Greek patients with sporadic Parkinson's disease.

An increasing number of clinical, neuropathological and experimental evidence linking Gaucher disease and a spectrum of synucleinopathies, including Parkinson's disease (PD) has emerged over the last decade. In particular, several studies, despite individual differences, have shown that mutations in the ß-glucocerebrosidase gene (GBA) are a risk factor for PD. Recently a study from Northern Greece has shown a significant overrepresentation of such mutations only in patients with early onset PD. In the present study 8 different GBA mutations covering 87% of the mutations identified in Gaucher disease patients diagnosed in Greece were investigated in two ethnic Greek cohorts of patients with sporadic Parkinson's disease. Cohort A included patients residing and originating from Thessaly, Central Greece (n=100) and cohort B included patients residing and/or originating from the greater area of Athens (n=105). Age-gender-ethnicity matched healthy individuals from the same areas were included as controls (n=206). In patients of cohort A 11 carriers of GBA mutations were identified (5/11:N370S, 2/11:L444P, 2/11: D409H;H255Q, 1/11:H255Q, 1/11D409H) as opposed to 3 in the controls (n=105) (1/3:N370S, 1/3:H255Q, 1/3:Y108C) (p=0.021, OR 4.2, 95% CI=1.14-15.54). In patients of cohort B 10 carriers of GBA mutations were identified (4/10:L444P, 4/10:D409H;H255Q, 1/10:N370S, 1/10:IVS10-1G→A) as opposed to 4 in controls (n=101) (3/4:N370S, 1/4:L444P). However the difference was not statistically significant (p=0.113, OR 2.5, 95% CI=0.77-8.42). In both cohorts, patients with PD harboring a GBA mutation had an earlier onset of symptoms than non-carriers (p=0.034, p=0.004). The overall difference in the number of carriers identified in PD patients and controls was statistically significant (p=0.006; OR 3.24; 95% CI=1.35-7.81). The association was reinforced in the early onset PD patients (EOPD; n=28, p=0.000, OR 11.37; 95% CI=3.73-34.6). In conclusion GBA mutations were identified with increased frequency in both geographical cohorts of patients with sporadic PD studied compared to control individuals, with the difference being statistically significant only in cohort A. An impressive association with EOPD was found and one third of the EOPD patients examined harbored a GBA mutation. Qualitative differences regarding the type of mutations and/or their relative frequencies were observed between cohorts A and B of PD patients. Genetic and/or environmental factors may account for the observed differences.

Gaucher disease: Biochemical and molecular findings in 141 patients diagnosed in Greece.

Gaucher disease (GD) is characterized by a marked phenotypic and genetic diversity. It is caused by the functional deficiency of the lysosomal enzyme ß-glucocerebrosidase (GCase), which in most instances results from mutations in the GBA1 gene and over 500 different disease causing mutations have been described. We present the biochemical and molecular findings in 141 GD cases (14 were siblings) with the three types of the disorder diagnosed in Greece over the last 35 years. 111/141 (78%) GD patients were of Greek origin. The remaining patients were Albanian (24/141; 17%), Syrian (2/141; 1.4%), Egyptian (2/141; 1.4%), Italian (1/141; 0.7%) and Polish (1/141; 0.7%). Mutation analysis identified 28 different mutations and 37 different genotypes. Seven of the mutations were not previously reported (T231I, D283N, N462Y, LI75P, F81L, Y135S and T482K). The most frequent mutations were N370S, D409H;H255Q and L444P. Mutation D409H;H255Q was only identified in Greek and Albanian patients. Sixteen mutations, including the novel ones, were identified only in one allele. Although the N370S mutation was identified only in type 1 patients, not all of type 1 patients carried this mutation. Our results highlight the heterogeneity of Gaucher disease and support the Balkan origin of the double mutant allele D409H;H255Q.

A novel mutation deep within intron 7 of the GBA gene causes Gaucher disease.

BACKGROUND: Mutations in the GBA gene that encodes the lysosomal enzyme acid ß-glucocerebrosidase cause Gaucher disease (GD), the most common lysosomal storage disorder. Most of the mutations are missense/nonsense, however, a few splicing mutations within or close to conserved consensus donor or acceptor splice sites have also been described. The aim of the study was to identify the mutation(s) in a Cypriot patient with type I GD. METHODS: The genomic DNA of the proband was screened for nine common mutations using Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis. All exons and exon-intron boundaries, and the 5'UTR and 3'UTR regions of the GBA gene, were investigated by Sanger sequencing. RNA analysis was performed using standard procedures, and the abnormal transcript was further cloned into pGEM-T-Easy plasmid vector and sequenced. The relevant intronic region was further sequenced by the Sanger method to identify the genetic variant. RESULTS: A novel point mutation, g.12599C > A (c.999 + 242C > A), was detected deep in intron 7 of the GBA gene. This type of mutation has been previously described for other diseases but this is the first time, as far as we know, that it is described for GD. This mutation creates a new donor splice site leading to aberrant splicing and resulting in the insertion of the first 239nt of intron 7 as a pseudoexon in the mRNA, creating a premature stop codon. CONCLUSION: This study expands the mutation spectrum of GD and highlights the importance of RNA sequencing for the molecular diagnosis of patients bearing mutations in nonexonic regions.

Neuronal and Astrocytic Differentiation from Sanfilippo C Syndrome iPSCs for Disease Modeling and Drug Development.

Sanfilippo syndrome type C (mucopolysaccharidosis IIIC) is an early-onset neurodegenerative lysosomal storage disorder, which is currently untreatable. The vast majority of studies focusing on disease mechanisms of Sanfilippo syndrome were performed on non-neural cells or mouse models, which present obvious limitations. Induced pluripotent stem cells (iPSCs) are an efficient way to model human diseases in vitro. Recently developed transcription factor-based differentiation protocols allow fast and efficient conversion of iPSCs into the cell type of interest. By applying these protocols, we have generated new neuronal and astrocytic models of Sanfilippo syndrome using our previously established disease iPSC lines. Moreover, our neuronal model exhibits disease-specific molecular phenotypes, such as increase in lysosomes and heparan sulfate. Lastly, we tested an experimental, siRNA-based treatment previously shown to be successful in patients' fibroblasts and demonstrated its lack of efficacy in neurons. Our findings highlight the need to use relevant human cellular models to test therapeutic interventions and shows the applicability of our neuronal and astrocytic models of Sanfilippo syndrome for future studies on disease mechanisms and drug development.

Antisense oligonucleotide treatment for a pseudoexon-generating mutation in the NPC1 gene causing Niemann-Pick type C disease.

Niemann-Pick type C disease is an autosomal recessive disorder caused by mutations in either the NPC1 or NPC2 gene. While most of the mutations are missense, a few splicing mutations have also been described. We identified and characterized a novel point mutation c.1554-1009G>A located in intron 9 of the NPC1 gene in a Spanish patient. Sequencing of the cDNA from the patient showed that this intronic mutation creates a cryptic donor splice site resulting in the incorporation of 194 bp of intron 9 as a new exon (pseudoexon) in the mRNA. This new transcript bears a premature termination codon and is degraded by the nonsense-mediated mRNA decay mechanism. Experimental confirmation that the point mutation generates the inclusion of a pseudoexon in the mRNA was obtained using a minigene. A specific antisense morpholino oligonucleotide targeted to the cryptic splice site was designed and transfected into fibroblasts from the patient. Using this approach, normal splicing was restored. These results demonstrate the importance of screening deep intronic regions and support the efficacy of antisense therapeutics for the treatment of diseases caused by pseudoexon-generating mutations.

Identification and characterization of SMPD1 mutations causing Niemann-Pick types A and B in Spanish patients.

Niemann-Pick disease (NPD) types A/B are both caused by a deficiency of lysosomal acid sphingomyelinase and display autosomal recessive inheritance. These two types of the disease were described according to the presence (type A) or absence (type B) of neurological symptoms. We present a molecular analysis of 19 Spanish NPD A/B patients and two from Maghreb. Eight of the patients had type A and 13 had type B NPD. All mutant SMPD1 alleles were identified, including 17 different mutations, 10 of which were novel. The only frequent mutations in the 21 NPD patients were c.1823_1825delGCC (p.R608del) (38%) and c.1445C>A (p.A482E) (9%). Genotype-phenotype correlations were established for most of the mutations and, in particular, the p.R608del-type B association was confirmed. This mutation accounts for 61.5% of the mutant alleles in the type B subgroup of patients. Expression studies performed on six of the identified mutations confirmed them to be disease-causing due to their low enzyme activity. An allele with a mutation affecting a noncanonical donor splice site produced only aberrant mRNAs, corresponding to previously reported nonfunctional SMPD1 minor transcripts. This study is the first exhaustive mutational analysis of Spanish Niemann-Pick A/B disease patients.

Promising results of the chaperone effect caused by imino sugars and aminocyclitol derivatives on mutant glucocerebrosidases causing Gaucher disease.

Gaucher disease is an autosomal recessive disorder. It is characterized by the accumulation of glucosylceramide in lysosomes of mononuclear phagocyte system, attributable to acid beta-glucosidase deficiency. The main consequences of this disease are hepatosplenomegaly, skeletal lesions and, sometimes, neurological manifestations. At sub-inhibitory concentrations, several competitive inhibitors act as chemical chaperones by inducing protein stabilization and increasing enzymatic activity. Here we tested two iminosugars (NB-DNJ and NN-DNJ) and four aminocyclitols with distinct degrees of lipophilicity as pharmacological chaperones for glucocerebrosidase (GBA). We report an increase in the activity of GBA using NN-DNJ, NB-DNJ and aminocyclitol 1 in stably transfected cell lines, and an increment with NN-DNJ and aminocyclitol 4 in patient fibroblasts. These results on specific mutations validate the use of chemical chaperones as a therapeutic approach for Gaucher disease. However, the development and analysis of new compounds is required in order to find more effective therapeutic agents that are active on a broader range of mutations.

Haplotype analysis suggests a single Balkan origin for the Gaucher disease [D409H;H255Q] double mutant allele.

Gaucher disease is an autosomal recessive lysosomal storage disease that is mainly due to mutations in the GBA gene. Most of the mutant alleles described so far bear a single mutation. However, there are a few alleles bearing two or more DNA changes. It has been reported that patients homozygous for the [D409H;H255Q] double mutant allele (HGVS-approved nomenclature, p.[D448H;H294Q]) present a more severe phenotype than patients homozygous for the relatively common D409H mutation. In this study, we confirmed the detrimental cumulative effect of these two mutations at the enzymatic activity level by the heterologous expression of the single and double mutant alleles. Additionally, we found a high frequency of the [D409H;H255Q] allele in patients from the Balkans and the Adriatic area of Italy. This prompted us to perform a haplotype analysis, using five microsatellite polymorphisms close to the GBA gene, to determine the origin of this allele. The results of the 37 chromosomes analysed showed that most of them share a common haplotype and are consistent with a single origin in the Balkans and the Adriatic area of Italy for the [D409H;H255Q] allele.