RESUMO
Parkinson's disease (PD) is characterized by dopaminergic (DA) cell loss and the accumulation of pathological alpha synuclein (asyn), but its precise pathomechanism remains unclear, and no appropriate animal model has yet been established. Recent studies have shown that a heterozygous mutation of glucocerebrosidase (gba) is one of the most important genetic risk factors in PD. To create mouse model for PD, we crossed asyn Bacterial Artificial Chromosome transgenic mice with gba heterozygous knockout mice. These double-mutant (dm) mice express human asyn in a physiological manner through its native promoter and showed an increase in phosphorylated asyn in the regions vulnerable to PD, such as the olfactory bulb and dorsal motor nucleus of the vagus nerve. Only dm mice showed a significant reduction in DA cells in the substantia nigra pars compacta, suggesting these animals were suitable for a prodromal model of PD. Next, we investigated the in vivo mechanism by which GBA insufficiency accelerates PD pathology, focusing on lipid metabolism. Dm mice showed an increased level of glucosylsphingosine without any noticeable accumulation of glucosylceramide, a direct substrate of GBA. In addition, the overexpression of asyn resulted in decreased GBA activity in mice, while dm mice tended to show an even further decreased level of GBA activity. In conclusion, we created a novel prodromal mouse model to study the disease pathogenesis and develop novel therapeutics for PD and also revealed the mechanism by which heterozygous gba deficiency contributes to PD through abnormal lipid metabolism under conditions of an altered asyn expression in vivo.
Assuntos
Glucosilceramidase/genética , Doença de Parkinson/genética , alfa-Sinucleína/genética , Animais , Modelos Animais de Doenças , Neurônios Dopaminérgicos/metabolismo , Neurônios Dopaminérgicos/patologia , Humanos , Metabolismo dos Lipídeos/genética , Camundongos , Camundongos Knockout , Camundongos Transgênicos , Doença de Parkinson/metabolismo , Doença de Parkinson/patologia , Parte Compacta da Substância Negra/metabolismo , Parte Compacta da Substância Negra/patologia , Sintomas ProdrômicosRESUMO
Niemann-Pick disease type C (NPC) is an autosomal recessive disorder characterized by progressive nervous degeneration. Because of the diversity of clinical symptoms and onset age, the diagnosis of this disease is difficult. Therefore, biomarker tests have attracted significant attention for earlier diagnostics. In this study, we developed a simultaneous analysis method for five urinary conjugated cholesterol metabolites, which are potential diagnostic biomarkers for a rapid, convenient, and noninvasive chemical diagnosis, using LC/MS/MS. By the method, their urinary concentrations were quantified and the NPC diagnostic performances were evaluated. The developed LC/MS/MS method showed high accuracy and satisfied all analytical method validation criteria. When the urine of healthy controls and patients with NPC was analyzed, three of five urinary conjugated cholesterol metabolite concentrations corrected by urinary creatinine were significantly higher in the patients with NPC. As a result of receiver operating characteristics analysis, these urinary metabolites might have excellent diagnostic marker performance. 3ß-Sulfooxy-7ß-hydroxy-5-cholenoic acid showed particularly excellent diagnostic performance with both 100% clinical sensitivity and specificity, suggesting that it is a useful NPC diagnostic marker. The urinary conjugated cholesterol metabolites exhibited high NPC diagnostic marker performance and could be used for NPC diagnosis.
Assuntos
Colesterol/urina , Doença de Niemann-Pick Tipo C/diagnóstico , Doença de Niemann-Pick Tipo C/urina , Adolescente , Adulto , Calibragem , Estudos de Casos e Controles , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , Adulto JovemRESUMO
The present study was designed to characterize transduction of non-human primate brain and spinal cord with a modified adeno-associated virus serotype 2, incapable of binding to the heparan sulfate proteoglycan receptor, referred to as AAV2-HBKO. AAV2-HBKO was infused into the thalamus, intracerebroventricularly or via a combination of both intracerebroventricular and thalamic delivery. Thalamic injection of this modified vector encoding GFP resulted in widespread CNS transduction that included neurons in deep cortical layers, deep cerebellar nuclei, several subcortical regions, and motor neuron transduction in the spinal cord indicative of robust bidirectional axonal transport. Intracerebroventricular delivery similarly resulted in widespread cortical transduction, with one striking distinction that oligodendrocytes within superficial layers of the cortex were the primary cell type transduced. Robust motor neuron transduction was also observed in all levels of the spinal cord. The combination of thalamic and intracerebroventricular delivery resulted in transduction of oligodendrocytes in superficial cortical layers and neurons in deeper cortical layers. Several subcortical regions were also transduced. Our data demonstrate that AAV2-HBKO is a powerful vector for the potential treatment of a wide number of neurological disorders, and highlight that delivery route can significantly impact cellular tropism and pattern of CNS transduction.
Assuntos
Terapia Genética , Vetores Genéticos/efeitos adversos , Neurônios/efeitos dos fármacos , Parvovirinae/genética , Medula Espinal/efeitos dos fármacos , Animais , Transporte Axonal/efeitos dos fármacos , Encéfalo/efeitos dos fármacos , Encéfalo/patologia , Proteínas do Capsídeo/administração & dosagem , Proteínas do Capsídeo/genética , Sistema Nervoso Central/efeitos dos fármacos , Sistema Nervoso Central/patologia , Dependovirus , Modelos Animais de Doenças , Vetores Genéticos/administração & dosagem , Vetores Genéticos/genética , Proteoglicanas de Heparan Sulfato/administração & dosagem , Proteoglicanas de Heparan Sulfato/genética , Humanos , Infusões Intraventriculares , Neurônios Motores/efeitos dos fármacos , Neurônios/patologia , Primatas , Medula Espinal/patologia , Tálamo/efeitos dos fármacosRESUMO
Niemann-Pick disease Type C (NPC) is a rare lysosomal storage disease characterized by the dysfunction of intracellular cholesterol trafficking with progressive neurodegeneration and hepatomegaly. We evaluated the potential of 6-O-α-maltosyl-ß-cyclodextrin (G2-ß-CD) as a drug candidate against NPC. The physicochemical properties of G2-ß-CD as an injectable agent were assessed, and molecular interactions between G2-ß-CD and free cholesterol were studied by solubility analysis and two-dimensional proton nuclear magnetic resonance spectroscopy. The efficacy of G2-ß-CD against NPC was evaluated using Npc1 deficient Chinese hamster ovary (CHO) cells and Npc1 deficient mice. G2-ß-CD in aqueous solution showed relatively low viscosity and surface activity; characteristics suitable for developing injectable formulations. G2-ß-CD formed higher-order inclusion complexes with free cholesterol. G2-ß-CD attenuated dysfunction of intercellular cholesterol trafficking and lysosome volume in Npc1 deficient CHO cells in a concentration dependent manner. Weekly subcutaneous injections of G2-ß-CD (2.9 mmol/kg) ameliorated abnormal cholesterol metabolism, hepatocytomegaly, and elevated serum transaminases in Npc1 deficient mice. In addition, a single cerebroventricular injection of G2-ß-CD (21.4 µmol/kg) prevented Purkinje cell loss in the cerebellum, body weight loss, and motor dysfunction in Npc1 deficient mice. In summary, G2-ß-CD possesses characteristics favorable for injectable formulations and has therapeutic potential against in vitro and in vivo NPC models.
Assuntos
Colesterol/metabolismo , Proteína C1 de Niemann-Pick/deficiência , Doença de Niemann-Pick Tipo C/tratamento farmacológico , beta-Ciclodextrinas/administração & dosagem , Animais , Células CHO , Cricetinae , Cricetulus , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Injeções Subcutâneas , Camundongos , Doença de Niemann-Pick Tipo C/metabolismo , Ressonância Magnética Nuclear Biomolecular , Resultado do Tratamento , beta-Ciclodextrinas/farmacologiaRESUMO
Niemann-Pick disease type C (NPC) is an autosomal recessive disorder caused by the mutation of cholesterol-transporting proteins. In addition, early treatment is important for good prognosis of this disease because of the progressive neurodegeneration. However, the diagnosis of this disease is difficult due to a variety of clinical spectrum. Lysosphingomyelin-509, which is one of the most useful biomarkers for NPC, was applied for the rapid and easy detection of NPC. The fact that its chemical structure was unknown until recently implicates the unrevealed pathophysiology and molecular mechanisms of NPC. In this study, we aimed to elucidate the structure of lysosphingomyelin-509 by various mass spectrometric techniques. As our identification strategy, we adopted analytical and organic chemistry approaches to the serum of patients with NPC. Chemical derivatization and hydrogen abstraction dissociation-tandem mass spectrometry were used for the determination of function groups and partial structure, respectively. As a result, we revealed the exact structure of lysosphingomyelin-509 as N-acylated and O-phosphocholine adducted serine. Additionally, we found that a group of metabolites with N-acyl groups were increased considerably in the serum/plasma of patients with NPC as compared to that of other groups using targeted lipidomics analysis. Our techniques were useful for the identification of lysosphingomyelin-509.
Assuntos
Lipídeos/química , Lipídeos/isolamento & purificação , Doença de Niemann-Pick Tipo C/diagnóstico , Fosforilcolina/química , Fosforilcolina/isolamento & purificação , Serina/química , Biomarcadores/sangue , Feminino , Humanos , Masculino , Doença de Niemann-Pick Tipo C/metabolismo , Fosforilcolina/metabolismo , Serina/metabolismo , Espectrometria de Massas em Tandem/métodosRESUMO
BACKGROUND: Niemann-Pick disease type C (NPC) is a lysosomal storage disorder with severe prognosis. Disease-specific therapy is crucial to prevent disease progression; however, diagnosing NPC is quite difficult because of remarkably variable clinical presentations. The NPC Suspicion Index (NPC-SI) was developed to overcome this problem. Identifying preclinical cases is important for prevention and therapy. Here, we report three newly diagnosed NPC cases, one typical juvenile-onset case and the cases of two sisters with symptoms neurologically/psychiatrically indistinguishable from dystonia and schizophrenia, respectively. CASE PRESENTATION: In Case 1, a 25-year-old man presented with a 14-year history of intellectual disability, clumsiness, spastic ataxia, dysphagia, and frequent falls. Neurological examination revealed vertical supranuclear gaze palsy and involuntary movements. Ultrasonography revealed mild splenomegaly, and filipin staining of skin fibroblasts was positive with a variant staining pattern. NPC1 gene analysis showed compound heterozygous mutations, including c.1421C > T (p.P474L), a known causative mutation, and c.3722 T > C (p.L1241S), a new mutation. In Case 2, a 28-year-old woman, the proband, who had marked splenomegaly in her childhood, survived well, contrary to the expected severe prognosis of infantile NPC. She had minor neuropsychiatric symptoms including auditory hallucinations, nocturnal urination, and sleep paralysis. At the age of 28 years, she presented with a 1-year history of orofacial and oromandibular painful dystonia. The patient's 35-year-old sister (Case 3) was diagnosed with schizophrenia. In both cases, filipin staining of skin fibroblasts was positive with variant staining patterns, as well as elevated levels of urinary bile acids. NPC1 gene analysis showed compound heterozygous mutations including c.3011C > T (p.S1004 L), a known causative mutation, and c.160_161insG (p.D54GfsX4), a new mutation. Their mother, who was under therapy with modafinil for narcolepsy, shared the latter mutation. CONCLUSIONS: Marked clinical variability was observed in our three cases. NPC could masquerade as a pure neuropsychiatric disorder such as dystonia or schizophrenia. Abdominal ultrasonography, history evaluation, and neurological examination were quite important in the diagnostic process.
Assuntos
Proteínas de Transporte/genética , Glicoproteínas de Membrana/genética , Doença de Niemann-Pick Tipo C , Esquizofrenia , Adulto , Variação Biológica da População , Feminino , Humanos , Peptídeos e Proteínas de Sinalização Intracelular , Masculino , Proteína C1 de Niemann-Pick , Doença de Niemann-Pick Tipo C/complicações , Doença de Niemann-Pick Tipo C/genética , Esquizofrenia/complicações , Esquizofrenia/genéticaRESUMO
Niemann-Pick disease type C (NPC) is a cholesterol storage disease caused by defective cellular cholesterol transportation. The onset and progression of NPC are variable, and autopsy findings have mainly been reported for the adult and juvenile forms of this disease. Here we report the clinical and pathological findings from a 9-year-old female patient with the late infantile form of NPC due to NPC1 gene mutation. She had notable splenomegaly at 4 months of age. She lost the ability to speak at 18 months of age. She learned to walk, but often fell and could no longer walk after 30 months. At 3 years of age, she was diagnosed with NPC. Sequence analysis of the NPC1 gene revealed compound heterozygous mutation of T2108C (F703S) and C2348G (S813X) (both novel). Thereafter, the patient suffered repeated respiratory infections and died of respiratory failure at 9 years of age. Pathological findings included cerebral atrophy (particularly of white matter), severe demyelination, and the loss of neurons from the cerebrum and from the nuclei of the brain stem. Remnant neuronal cells and microglia in the cerebrum, cerebellum, and brain stem had become swollen and foamy. Neurons of the hippocampal CA1 and Purkinje cells were relatively spared, and senile plaques and axonal spheroids were not present. Foamy cells were also observed in other organs, especially the spleen and bone marrow. The F703S mutation in this patient was localized in a sterol-sensing domain (SSD). Severe neurological phenotypes have been previously reported in patients with missense mutations in an SSD. It is considered that the combination of a nonsense mutation and missense mutation in an SSD was responsible for the severe neurological phenotype of our present patient. While pathological findings of adult/juvenile forms of NPC have included swollen neurons and glia, neuronal cell loss, and NFTs, demyelination may be a predominant finding in the infantile form of NPC.
Assuntos
Encéfalo/patologia , Doenças Desmielinizantes/patologia , Doença de Niemann-Pick Tipo C/patologia , Criança , Feminino , HumanosRESUMO
An 11-year-old boy with Lesch-Nyhan syndrome (LNS) had persistently injured himself by biting his lips and buccal mucosa since infancy. Risperidone was only partially effective in suppressing this behavior. Oral administration of S-adenosylmethionine (SAMe), involving increasing the dose from 400 mg to 1 g, resulted in the amelioration of self-injurious behavior and anxiety as well as marked improvement in his self-esteem, performance at school, and friendships. No adverse effects were noted. SAMe may have a favorable effect on symptoms of LNS by activating monoaminergic pathways and/or increasing the adenosine pool in the salvage pathway of guanosine monophosphate synthesis. Defects in these pathways have been essentially implicated in the neurological pathophysiology of LNS.
Assuntos
Síndrome de Lesch-Nyhan/terapia , S-Adenosilmetionina/uso terapêutico , Comportamento Autodestrutivo/tratamento farmacológico , Criança , Humanos , Hipoxantina Fosforribosiltransferase/genética , Síndrome de Lesch-Nyhan/complicações , Masculino , Qualidade de Vida , Comportamento Autodestrutivo/etiologiaRESUMO
This study was conducted to evaluate the attenuating potential of 2-hydroxypropyl-ß-cyclodextrin (HPBCD) against Niemann-Pick Type C (NPC) disease, as well as the physical and chemical properties, particularly the cholesterol-solubilizing ability, in an NPC disease model in vitro. As parameters of NPC abnormalities, intracellular free and esterified cholesterol levels and lysosome volume were measured in Npc1 null Chinese hamster ovary cells. HPBCD showed dose-dependent effects against dysfunctional intracellular cholesterol trafficking, such as the accumulation and shortage of free and esterified cholesterols, respectively, in Npc1 null cells. However, the effectiveness was gradually offset by exposure to ≥8mM HPBCD. The same effect was also observed for increasing lysosome volume in Npc1 null cells. The degree of substitution of the hydroxypropyl group had little influence on the attenuating effects of HPBCD against the NPC abnormalities, at least in the range between 2.8 and 7.4. Next, we compared the effects of other hydroxyalkylated ß-cyclodextrin derivatives with different cholesterol-solubilizing abilities, such as 2-hydroxyethyl-ß-cyclodextrin (HEBCD) and 2-hydroxybutyl-ß-cyclodextrin (HBBCD). The cholesterol solubilizing potential, attenuating effects against NPC abnormalities and cytotoxicity induction were HBBCDâ«HPBCD>HEBCD, HBBCD=HPBCD>HEBCD and HBBCDâ«HPBCD=HEBCD, respectively. HPBCD may be superior in terms of safety and efficacy in Npc1 null cells compared with HEBCD and HBBCD. The results of this study will provide a rationale for the optimization of HPBCD therapy for NPC disease.
Assuntos
Proteínas de Transporte/metabolismo , Colesterol/metabolismo , Doença de Niemann-Pick Tipo C/metabolismo , beta-Ciclodextrinas/farmacologia , 2-Hidroxipropil-beta-Ciclodextrina , Animais , Células CHO , Cricetulus , Relação Dose-Resposta a Droga , Humanos , Lisossomos/efeitos dos fármacos , Lisossomos/metabolismo , Modelos Biológicos , Doença de Niemann-Pick Tipo C/tratamento farmacológico , beta-Ciclodextrinas/uso terapêuticoRESUMO
Niemann-Pick type C (NPC) disease is an autosomal recessive neurodegenerative disorder which is caused in 95% by a mutation in the NPC1 gene on chromosome 18 or by NPC2 mutation, encoding for 2 different lysosomal lipid transport proteins. The impaired protein function leads to systemic intralysosomal accumulation of free cholesterol and shingolipids particularly in the CNS. In Japan, currently 34 living NPC patients are known as of December 2015. Considering the prevalence of the disease in the Western countries, the real number of NPC patients is most likely to be five-folds higher. For NPC, treatment methods are established and an approved disease-specific medications are available. It is important that patients early in their disease are referred to expert centers, in order to ensure timely initiation of treatment and to delay the progression of neurological symptoms as a goal.
Assuntos
Doença de Niemann-Pick Tipo C , Biomarcadores/análise , Humanos , Doença de Niemann-Pick Tipo C/diagnóstico , Doença de Niemann-Pick Tipo C/epidemiologia , Doença de Niemann-Pick Tipo C/fisiopatologia , Doença de Niemann-Pick Tipo C/terapia , PrognósticoRESUMO
Enlarged parietal foramina (EPF) are rare congenital skull defects. These round or oval defects are situated on each parietal bone approximately 1 cm from the midline. Most patients with EPF have a positive family history. The condition is inherited as an autosomal dominant trait with relatively high, but not full, penetrance. Mutation in either MSX2 or ALX4 genes is associated with enlarged parietal foramina. Case 1 is a boy who was noticed to have a large anterior fontanelle, large posterior fontanelle, and widely opened sagittal suture at 2 months. During development, the anterior fontanelle and sagittal suture closed at 3 years and the posterior fontanelle subsequently divided into two foramina with ossification of the midline bridge by 4 years. The foramina were about 2.5 x 2.5 cm in diameter at 8 years. Case 2 is the 34-year-old mother of Case 1. She showed similar bone defects in her cranium, again about 2.5 x 2.5 cm in diameter. Neither patient showed any neurological symptoms. Genetic analysis revealed a mutation in the ALX4 gene in both patients, and magnetic resonance imaging showed a persistent falcine sinus and a hypoplastic straight sinus. Further evaluation revealed that the mother of Case 2 also had a mutation in the ALX4 gene, but no enlarged parietal foramina. Although high penetrance of this condition has been reported, this family suggests incomplete penetrance of this disorder.
Assuntos
Cavidades Cranianas/anormalidades , Proteínas de Ligação a DNA/genética , Encefalocele/diagnóstico , Encefalocele/genética , Mutação , Osso Parietal/anormalidades , Fatores de Transcrição/genética , Adulto , Cavidades Cranianas/patologia , Encefalocele/patologia , Feminino , Humanos , Imageamento Tridimensional , Lactente , Angiografia por Ressonância Magnética , Imageamento por Ressonância Magnética , Masculino , Osso Parietal/patologia , Tomografia Computadorizada por Raios XRESUMO
Most cases with Niemann-Pick disease type C carry mutations in NPC1. Some of the mutations, including the most frequent I1061T, give rise to unstable proteins selected for endoplasmic reticulum-associated degradation. The purpose of the current study was to shed mechanistic insights into the degradation process. A proteasome inhibitor MG132 prolonged the life span of the wild-type NPC1 expressed in COS cells. The expressed protein associated with multiple chaperones including heat shock protein 90 (Hsp90), Hsp70, heat shock cognate protein 70 (Hsc70), and calnexin. Accordingly, expression of an E3 ligase CHIP (carboxyl terminus of Hsp70-interacting protein) enhanced MG132-induced accumulation of ubiquitylated NPC1. Co-expression and RNAi knockdown experiments in HEK cells indicated that Hsp70/Hsp90 stabilized NPC1, whereas Hsc70 destabilized it. In human fibroblasts carrying the I1061T mutation, adenovirus-mediated expression of Hsp70 or treatment with an HSP-inducer geranylgeranylacetone (GGA) increased the level of the mutant protein. In GGA-treated cells, the rescued protein was localized in the late endosome and ameliorated cholesterol accumulation. MALDI-TOF mass spectrometry revealed three lysine residues at amino acids 318, 792, and 1180 as potential ubiquitin-conjugation sites. Substitutions of the three residues with alanine yielded a mutant protein with a steady-state level more than three times higher than that of the wild-type. Introduction of the same substitutions to the I1061T mutant resulted in an increase in its protein level and functional restoration. These findings indicated the role of HSPs in quality control of NPC1 and revealed the role of three lysine residues as ubiquitin-conjugation sites.
Assuntos
Proteínas de Choque Térmico HSC70/metabolismo , Proteínas de Choque Térmico HSP90/metabolismo , Proteínas de Membrana/metabolismo , Doenças de Niemann-Pick/metabolismo , Ubiquitina/metabolismo , Substituição de Aminoácidos , Animais , Células COS , Chlorocebus aethiops , Inibidores de Cisteína Proteinase/farmacologia , Técnicas de Silenciamento de Genes , Células HEK293 , Proteínas de Choque Térmico HSC70/genética , Proteínas de Choque Térmico HSP90/genética , Humanos , Leupeptinas/farmacologia , Proteínas de Membrana/genética , Proteínas de Membrana Transportadoras , Mutação de Sentido Incorreto , Doenças de Niemann-Pick/genética , Terpenos/farmacologia , Ubiquitina/genética , Ubiquitinação/efeitos dos fármacos , Ubiquitinação/genéticaRESUMO
Niemann-Pick type C disease (NPC), an autosomal recessive lysosomal storage disorder, is an inherited disease characterized by the accumulation of intracellular unesterified cholesterol. A solubilizing agent of lipophilic compounds, 2-hydroxypropyl-ß-cyclodextrin (HPBCD), is an attractive drug candidate against NPC disease. However, establishment of the optimum dosage of HPBCD remains to be determined. In this study, we evaluated the effective dosage of HPBCD in NPC model (Npc1(-/-)) mice, and determined serum HPBCD concentrations. Subcutaneous injection of 1000-4000 mg/kg HPBCD improved the lifespan of Npc1(-/-) mice. In addition, liver injury and cholesterol sequestration were significantly prevented by 4000 mg/kg HPBCD in Npc1(-/-) mice. Serum HPBCD concentrations, when treated at the effective dosages (1000-4000 mg/kg), were approximately 1200-2500 µg/mL at 0.5 h after subcutaneous injection, and blood HPBCD concentrations were immediately eliminated in Npc1(-/-) mice. Furthermore, we examined serum HPBCD concentrations when treated at 40000 mg (approximately 2500 mg/kg) in a patient with NPC. We observed that the effective concentration in the in vivo study using Npc1(-/-) mice was similar to that in the patient. In the patient, systemic clearance and the volume of distribution of HPBCD were in accordance with the glomerular filtration rate and extracellular fluid volume, respectively. These results could provide useful information for developing the optimal dosage regimen for HPBCD therapy when administered intravenously to NPC patients.
Assuntos
Colesterol/metabolismo , Doença de Niemann-Pick Tipo C/tratamento farmacológico , beta-Ciclodextrinas/administração & dosagem , 2-Hidroxipropil-beta-Ciclodextrina , Animais , Modelos Animais de Doenças , Humanos , Peptídeos e Proteínas de Sinalização Intracelular , Fígado/efeitos dos fármacos , Fígado/metabolismo , Hepatopatias/etiologia , Hepatopatias/metabolismo , Hepatopatias/prevenção & controle , Masculino , Camundongos , Camundongos Knockout , Proteína C1 de Niemann-Pick , Doença de Niemann-Pick Tipo C/complicações , Proteínas/genética , Solubilidade , beta-Ciclodextrinas/sangue , beta-Ciclodextrinas/farmacocinética , beta-Ciclodextrinas/uso terapêuticoRESUMO
A general approach is reported for the design of small-molecule competitive inhibitors of lysosomal glycosidases programmed to 1) promote correct folding of mutant enzymes at the endoplasmic reticulum, 2) facilitate trafficking, and 3) undergo dissociation and self-inactivation at the lysosome. The strategy is based on the incorporation of an orthoester segment into iminosugar conjugates to switch the nature of the aglycone moiety from hydrophobic to hydrophilic in the pH 7 to pH 5 window, which has a dramatic effect on the enzyme binding affinity. As a proof of concept, new highly pH-responsive glycomimetics targeting human glucocerebrosidase or α-galactosidase with strong potential as pharmacological chaperones for Gaucher or Fabry disease, respectively, were developed.
Assuntos
Glicosídeo Hidrolases/genética , Glicosídeo Hidrolases/metabolismo , Proteínas Mutantes/genética , Proteínas Mutantes/metabolismo , Bibliotecas de Moléculas Pequenas/farmacologia , Relação Dose-Resposta a Droga , Inibidores Enzimáticos/química , Inibidores Enzimáticos/farmacologia , Glicosídeo Hidrolases/antagonistas & inibidores , Glicosídeo Hidrolases/química , Humanos , Concentração de Íons de Hidrogênio , Ligantes , Lisossomos/enzimologia , Lisossomos/metabolismo , Estrutura Molecular , Proteínas Mutantes/antagonistas & inibidores , Proteínas Mutantes/química , Mutação , Dobramento de Proteína/efeitos dos fármacos , Transporte Proteico/efeitos dos fármacos , Bibliotecas de Moléculas Pequenas/química , Relação Estrutura-AtividadeRESUMO
Gaucher disease (GD) is a rare monogenetic disorder leading to dysfunction of acid ß-glucosidase (ß-glucocerebrosidase; GCase) and accumulation of glucosylceramide in lysosomes, especially in macrophages (Gaucher cells). Many of the mutations at the origin of GD do not impair the catalytic activity of GCase, but cause misfolding and subsequent degradation by the quality control system at the endoplasmic reticulum. Pharmacological chaperones (PCs) capable of restoring the correct folding and trafficking of the endogenous mutant enzyme represent promising alternatives to the currently available enzyme replacement and substrate reduction therapies (ERT and SRT, respectively), but unfavorable biodistribution and potential side-effects remain important issues. We have now designed a strategy to enhance the controlled delivery of PCs to macrophages that exploit the formation of ternary complexes between the PC, a trivalent mannosylated ß-cyclodextrin (ßCD) conjugate and the macrophage mannose receptor (MMR). First, PC candidates with appropriate relative avidities towards the ßCD cavity and the GCase active site were selected to ensure efficient transfer of the PC cargo from the host to the GCase active site. Control experiments confirmed that the ßCD carrier was selectively recognized by mannose-specific lectins and that the corresponding PC:mannosylated ßCD supramolecular complex retained both the chaperoning activity, as confirmed in human GD fibroblasts, and the MMR binding ability. Finally, fluorescence microscopy techniques proved targeting and cellular uptake of the PC-loaded system in macrophages. Altogether, the results support that combined cyclodextrin encapsulation and glycotargeting may improve the efficacy of PCs for GD.
Assuntos
Portadores de Fármacos/administração & dosagem , Portadores de Fármacos/química , Sistemas de Liberação de Medicamentos , Doença de Gaucher/tratamento farmacológico , Macrófagos/metabolismo , Chaperonas Moleculares/administração & dosagem , beta-Ciclodextrinas/química , Configuração de Carboidratos , Doença de Gaucher/patologia , Humanos , Macrófagos/efeitos dos fármacos , Microscopia de Fluorescência , Chaperonas Moleculares/farmacologia , Chaperonas Moleculares/uso terapêutico , beta-Ciclodextrinas/administração & dosagemRESUMO
Lysosomal ß-galactosidase (ß-Gal) deficiency causes a group of disorders that include neuronopathic GM1 gangliosidosis and non-neuronopathic Morquio B disease. We have previously proposed the use of small molecule ligands of ß-Gal as pharmacological chaperones (PCs) for the treatment of GM1 gangliosidosis brain pathology. Although it is still under development, PC therapy has yielded promising preclinical results in several lysosomal diseases. In this study, we evaluated the effect of bicyclic 1-deoxygalactonojirimycin (DGJ) derivative of the sp(2)-iminosugar type, namely 5N,6S-(N'-butyliminomethylidene)-6-thio-1- deoxygalactonojirimycin (6S-NBI-DGJ), as a novel PC for human mutant ß-Gal. In vitro, 6S-NBI-DGJ had the ability to inhibit the activity of human ß-Gal in a competitive manner and was able to protect this enzyme from heat-induced degradation. Computational analysis supported that the rigid glycone bicyclic core of 6S-NBI-DGJ binds to the active site of the enzyme, with the aglycone N'-butyl substituent, in a precise E-orientation, located at a hydrophobic region nearby. Chaperone potential profiling indicated significant increases of enzyme activity in 24 of 88 ß-Gal mutants, including four common mutations. Finally, oral administration of 6S-NBI-DGJ ameliorated the brain pathology of GM1 gangliosidosis model mice. These results suggest that 6S-NBI-DGJ is a novel PC that may be effective on a broad range of ß-Gal mutants.
Assuntos
1-Desoxinojirimicina/análogos & derivados , Gangliosidose GM1/tratamento farmacológico , Chaperonas Moleculares/farmacologia , 1-Desoxinojirimicina/farmacologia , Administração Oral , Animais , Compostos Bicíclicos Heterocíclicos com Pontes/farmacologia , Células Cultivadas , Biologia Computacional , Modelos Animais de Doenças , Inibidores Enzimáticos/farmacologia , Fibroblastos/efeitos dos fármacos , Fibroblastos/metabolismo , Gangliosidose GM1/genética , Imino Açúcares/química , Imino Açúcares/farmacologia , Lisossomos/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Mucopolissacaridose IV/tratamento farmacológico , Mucopolissacaridose IV/genética , Mutação , Recombinação Genética , beta-Galactosidase/química , beta-Galactosidase/genéticaRESUMO
BACKGROUND: Acute pancreatitis in patients with severe motor and intellectual disability (SMID) is a rare but life-threatening condition. Possible causes of acute pancreatitis in these patients including valproic acid therapy, hypothermia and nasoduodenal tube feeding, have not yet been investigated in detail. The aim of this study was therefore to investigate the risk factors for acute pancreatitis in patients with SMID. METHODS: Five SMID patients with acute pancreatitis and 15 SMID patients without acute pancreatitis were reviewed. Age; serum total cholesterol, triglyceride, total protein, and albumin; height; bodyweight; body surface area; body mass index; daily calorie intake; daily calorie intake per unit of body mass surface area; daily calorie intake per kilogram bodyweight; and valproic acid usage were examined. RESULTS: A statistically significant difference was observed in serum albumin level between the two groups (P = 0.026). CONCLUSION: The mechanism of acute pancreatitis in these patients was considered as pancreatic morphological change, acinar damage, and elevated serum trypsinogen level caused by malnutrition. It is likely that acute pancreatitis in patients with SMID occurs due to the same mechanism as in anorexia nervosa and malnourished patients. To prevent acute pancreatitis in these patients, it is important to maintain adequate nutritional status.
Assuntos
Deficiência Intelectual/complicações , Transtornos das Habilidades Motoras/complicações , Pancreatite/complicações , Doença Aguda , Adolescente , Criança , Pré-Escolar , Feminino , Humanos , Masculino , Estudos Retrospectivos , Fatores de Risco , Índice de Gravidade de Doença , Adulto JovemRESUMO
Niemann-Pick Type C disease (NPC) is an autosomal recessive lysosomal storage disorder characterized by progressive neurological deterioration. Currently, there are no effective treatments for NPC, although miglustat has shown some effectiveness in stabilizing neurological status in juvenile-onset NPC patients. Recent studies have demonstrated the efficacy of hydroxypropyl-ß-cyclodextrin (HPB-CD) in NPC mice. Herein, we describe the effects of HPB-CD in two patients with NPC. The two patients received HPB-CD infusions twice (Patient 2) or thrice (Patient 1) weekly, starting with a dose of 80 mg/kg per dose that was increased gradually to 2g/kg per dose (Patient 2) or 2.5 g/kg per dose (Patient 1). Although HPB-CD did not improve the neurological deficits in either patient, it was partially effective in improving hepatosplenomegaly and central nervous system dysfunction, especially during the first 6 months of treatment. No adverse effects were observed over the course of treatment, although Patient 1 exhibited transient cloudiness of the lungs with fever after 2 years. For more effective treatment of NPC patients with HPB-CD, it is necessary to improve drug delivery into the central nervous system.
Assuntos
Doença de Niemann-Pick Tipo C/tratamento farmacológico , beta-Ciclodextrinas/uso terapêutico , 2-Hidroxipropil-beta-Ciclodextrina , Adolescente , Pré-Escolar , Feminino , HumanosRESUMO
Alcohol use disorder (AUD) exacts enormous personal, social and economic costs globally. Return to alcohol use in treatment-seeking patients with AUD is common, engendered by a cycle of repeated abstinence-relapse episodes even with use of currently available pharmacotherapies. Repeated ethanol use induces dopaminergic signaling neuroadaptations in ventral tegmental area (VTA) neurons of the mesolimbic reward pathway, and sustained dysfunction of reward circuitry is associated with return to drinking behavior. We tested this hypothesis by infusing adeno-associated virus serotype 2 vector encoding human glial-derived neurotrophic factor (AAV2-hGDNF), a growth factor that enhances dopaminergic neuron function, into the VTA of four male rhesus monkeys, with another four receiving vehicle, following induction of chronic alcohol drinking. GDNF expression ablated the return to alcohol drinking behavior over a 12-month period of repeated abstinence-alcohol reintroduction challenges. This behavioral change was accompanied by neurophysiological modulations to dopamine signaling in the nucleus accumbens that countered the hypodopaminergic signaling state associated with chronic alcohol use, indicative of a therapeutic modulation of limbic circuits countering the effects of alcohol. These preclinical findings suggest gene therapy targeting relapse prevention may be a potential therapeutic strategy for AUD.