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1.
Acta Neuropathol ; 145(5): 637-650, 2023 05.
Article in English | MEDLINE | ID: mdl-36879070

ABSTRACT

A missense variant from methionine to arginine at codon 232 (M232R) of the prion protein gene accounts for ~ 15% of Japanese patients with genetic prion diseases. However, pathogenic roles of the M232R substitution for the induction of prion disease have remained elusive because family history is usually absent in patients with M232R. In addition, the clinicopathologic phenotypes of patients with M232R are indistinguishable from those of sporadic Creutzfeldt-Jakob disease patients. Furthermore, the M232R substitution is located in the glycosylphosphatidylinositol (GPI)-attachment signal peptide that is cleaved off during the maturation of prion proteins. Therefore, there has been an argument that the M232R substitution might be an uncommon polymorphism rather than a pathogenic mutation. To unveil the role of the M232R substitution in the GPI-attachment signal peptide of prion protein in the pathogenesis of prion disease, here we generated a mouse model expressing human prion proteins with M232R and investigated the susceptibility to prion disease. The M232R substitution accelerates the development of prion disease in a prion strain-dependent manner, without affecting prion strain-specific histopathologic and biochemical features. The M232R substitution did not alter the attachment of GPI nor GPI-attachment site. Instead, the substitution altered endoplasmic reticulum translocation pathway of prion proteins by reducing the hydrophobicity of the GPI-attachment signal peptide, resulting in the reduction of N-linked glycosylation and GPI glycosylation of prion proteins. To the best of our knowledge, this is the first time to show a direct relationship between a point mutation in the GPI-attachment signal peptide and the development of disease.


Subject(s)
Creutzfeldt-Jakob Syndrome , Prion Diseases , Prions , Animals , Mice , Humans , Prion Proteins/genetics , Point Mutation , Glycosylphosphatidylinositols/genetics , Glycosylphosphatidylinositols/metabolism , Protein Sorting Signals/genetics , Prion Diseases/genetics , Prion Diseases/pathology , Creutzfeldt-Jakob Syndrome/genetics , Creutzfeldt-Jakob Syndrome/pathology , Prions/genetics , Prions/metabolism , Mutation/genetics
2.
Neuropathology ; 43(6): 479-485, 2023 Dec.
Article in English | MEDLINE | ID: mdl-37165430

ABSTRACT

Genetic Creutzfeldt-Jakob disease (gCJD) with a V180I mutation (V180I gCJD) is the most common type of gCJD in Japan, characterized by an older age at onset, slower progression, and moderate to severe cortical degeneration with spongiform changes and sparing of the brainstem and cerebellum. Degeneration of the inferior olivary nucleus (IO) is rarely observed in patients with CJD but is known to occur in fatal familial insomnia (FFI) and MM2-thalamic-type sporadic CJD (sCJD-MM2T) involving type 2 prion protein (M2T prion). Here we report on an 81-year-old Japanese woman who initially developed depressive symptoms followed by progressive cognitive impairment, myoclonus, and hallucinations and died after a clinical course of 23 months. Insomnia was not evident. Genetic analysis of the prion protein (PrP) identified a V180I mutation with methionine/valine heterozygosity at codon 129. Pathologic analysis demonstrated extensive spongiform degeneration, neuronal loss in the cortices, and weak synaptic-type PrP deposition. Except for IO degeneration, the clinicopathologic features and Western blotting PrP band pattern were compatible with those of previously reported V180I gCJD cases. Quantitative analysis revealed that the neuronal density of the IO, especially in the dorsal area, was considerably reduced to the same extent as that of a patient with sCJD-MM2T but preserved in other patients with V180I gCJD and sCJD-MM1 (this patient, 2.3 ± 0.53/mm2 ; a patient with sCJD-MM2T, 4.2 ± 2; a patient with V180I gCJD, 60.5 ± 9.3; and a patient with sCJD-MM1, 84.5 ± 17.9). Use of the protein misfolding cyclic amplification (PMCA) method confirmed the presence of the M2T prion strain, suggesting that the latter might be associated with IO degeneration in V180I gCJD. Autopsy studies are necessary to better understand the nature of CJD, since even if patients present with the common clinical picture, pathologic analysis might provide new insights, as was the case here.


Subject(s)
Creutzfeldt-Jakob Syndrome , Prions , Female , Humans , Aged, 80 and over , Prions/metabolism , Creutzfeldt-Jakob Syndrome/pathology , Prion Proteins/genetics , Prion Proteins/metabolism , Autopsy , Olivary Nucleus/pathology
3.
BMC Neurol ; 21(1): 480, 2021 Dec 10.
Article in English | MEDLINE | ID: mdl-34893033

ABSTRACT

BACKGROUND: Late-stage Parkinson's disease (PD) often presents with neuropsychiatric symptoms such as dementia, psychosis, excessive daytime sleepiness, apathy, depression, and anxiety. However, neuropsychiatric symptoms are the cardinal features of Creutzfeldt-Jakob disease (CJD), raising the possibility that CJD may be an overlooked condition when it accompanies late-stage PD. CASE PRESENTATION: We describe a female autopsy case of PD with a typical clinical course of 17 years, in which CJD overlapped with PD during the final year of the patient's life. The patient died aged 85 years. Neuropathological features included widespread Lewy body-related α-synucleinopathy predominantly in the brainstem and limbic system, as well as the typical pathology of methionine/methionine type 1 CJD in the brain. CONCLUSIONS: Our case demonstrates the clinicopathological co-occurrence of PD and CJD in a sporadic patient. The possibility of mixed pathology, including prion pathology, should be taken into account when neuropsychiatric symptoms are noted during the disease course of PD.


Subject(s)
Creutzfeldt-Jakob Syndrome , Parkinson Disease , Prions , Autopsy , Brain/diagnostic imaging , Brain/metabolism , Creutzfeldt-Jakob Syndrome/complications , Female , Humans , Parkinson Disease/complications , Prions/metabolism
4.
Neuropathology ; 41(3): 206-213, 2021 Jun.
Article in English | MEDLINE | ID: mdl-33586250

ABSTRACT

Genetic Creutzfeldt-Jakob disease (gCJD) with a methionine to arginine substitution at codon 232 of the prion protein gene (gCJD-M232R) is rare and has only been reported in Japan. We report an autopsy case of gCJD-M232R showing alleles of codon 129 that were homozygous for methionine and the presence of multiple strains of the protease-resistant, abnormal isoform of prion protein (PrPSc ), M1 + M2C + M2T. The patient, a 54-year-old Japanese man, died after a clinical course of 21 months characterized by slowly progressive dementia and sleep disturbance. At autopsy, the neuropil of the cerebral neocortex showed a widespread and severe spongiform change. Grape-like clusters of large confluent vacuoles were admixed with fine vacuoles. Neuronal loss was moderate, but reactive astrocytosis was mild. The dorsomedial nucleus of the thalamus and the inferior olivary nucleus showed moderate and severe neuronal loss, respectively. Many amyloid plaques were present in the cerebellar molecular layer. PrPSc deposition pattern was predominantly the synaptic type in the cerebrum and corresponded to the plaques in the cerebellum. Perivacuolar deposition was also seen. Western blot analysis of PrPSc revealed the predominance of type 2. Moreover, by employing Western blot analysis in combination with the protein misfolding cyclic amplification (PMCA) method, which selectively amplifies the minor M2T prion strain, we demonstrated the presence of M2T, in addition to M1 and M2C strains, in the brain of the patient. PMCA was a powerful method for demonstrating the presence of the M2T strain, although the amount is often small and the transmission is difficult.


Subject(s)
Creutzfeldt-Jakob Syndrome/genetics , Creutzfeldt-Jakob Syndrome/pathology , Methionine/genetics , PrPSc Proteins/genetics , Atrophy/genetics , Atrophy/pathology , Autopsy , Blotting, Western , Cerebellum/pathology , Cerebrum/pathology , Humans , Japan , Magnetic Resonance Imaging , Male , Middle Aged , Mutation , Myocardium/pathology , Thalamus/pathology
5.
Bioorg Med Chem Lett ; 30(8): 127059, 2020 04 15.
Article in English | MEDLINE | ID: mdl-32127260

ABSTRACT

We synthesized novel vitamin K derivatives by converting the naphthoquinone group to benzene derivatives and benzoquinone. We evaluated their neuronal differentiation activities to investigate the effect of the quinone moiety on this process. We observed that the 1,4-quinone as well as the side chain part play important roles in neuronal differentiation. We also performed QSAR analysis to predict the compounds which would have higher differentiation activity.


Subject(s)
Benzene Derivatives/pharmacology , Benzoquinones/pharmacology , Naphthoquinones/pharmacology , Neurons/drug effects , Vitamin K/pharmacology , Animals , Benzene Derivatives/chemistry , Benzoquinones/chemistry , Cell Differentiation/drug effects , Dose-Response Relationship, Drug , Mice , Molecular Structure , Naphthoquinones/chemistry , Quantitative Structure-Activity Relationship , Vitamin K/chemistry
6.
Molecules ; 24(23)2019 Nov 26.
Article in English | MEDLINE | ID: mdl-31779181

ABSTRACT

We aimed to synthesize novel liver X receptor (LXR) agonists with potent agonist activity and subtype selectivity. Our synthetic scheme started with naphthoquinone derivatives, such as menadione and 2,3-dichloro-1,4-naphthoquinone. We introduced different substituents into the naphthoquinone structures, including aniline, piperidine, pyrrolidine, and morpholine, in one or two steps, and thus, we produced 14 target compounds. All 14 synthetic ligands were tested to determine whether they mediated LXR-mediated transcriptional activity. We investigated the transcriptional activity of each compound with two types of receptors, LXRα and LXRß. Among all 14 compounds, two showed weak LXRß-agonist activity, and two others exhibited potent LXRα-agonist activity. We also performed docking studies to obtain a better understanding of the modes of compound binding to LXR at the atomic level. In conclusion, we successfully synthesized naphthoquinone derivatives that act as LXRα/ß agonists and selective LXRα agonists.


Subject(s)
Liver X Receptors/metabolism , Naphthoquinones/pharmacology , Cell Line , HEK293 Cells , Humans , Ligands , Transcription, Genetic/drug effects , Transcription, Genetic/physiology
7.
Lab Invest ; 96(5): 581-7, 2016 05.
Article in English | MEDLINE | ID: mdl-26878132

ABSTRACT

There are two distinct subtypes of dura mater graft-associated Creutzfeldt-Jakob disease (dCJD) with methionine homozygosity at codon 129 of the PRNP gene. The majority of cases is represented by a non-plaque-type (np-dCJD) resembling sporadic CJD (sCJD)-MM1 or -MV1, while the minority by a plaque-type (p-dCJD). p-dCJD shows distinctive phenotypic features, namely numerous kuru plaques and an abnormal isoform of prion protein (PrP(Sc)) intermediate in size between types 1 and 2. Transmission studies have shown that the unusual phenotypic features of p-dCJD are linked to the V2 prion strain that is associated with sCJD subtypes VV2 or -MV2. In this study, we applied protein misfolding cyclic amplification (PMCA) using recombinant human prion protein as a substrate and demonstrated that p-dCJD prions show amplification features that are distinct from those of np-dCJD. Although no amplification of np-dCJD prions was observed with either 129 M or 129 V substrate, p-dCJD prions were drastically amplified with the 129 V substrates, despite the PRNP codon 129 incompatibility between seed and substrate. Moreover, by using a type 2 PrP(Sc)-specific antibody not recognizing PrP(Sc) in p-dCJD, we found that type 2 products are generated de novo from p-dCJD prions during PMCA with the 129 V substrates. These findings suggest that our cell-PMCA is a useful tool for easily and rapidly identifying acquired CJD associated with the transmission of the V2 CJD strain to codon 129 methionine homozygotes, based on the preference for the 129 V substrate and the type of the amplified products.


Subject(s)
Creutzfeldt-Jakob Syndrome/genetics , Creutzfeldt-Jakob Syndrome/metabolism , Dura Mater/transplantation , Prion Proteins/genetics , Prion Proteins/metabolism , Brain/metabolism , Brain/pathology , Codon , Creutzfeldt-Jakob Syndrome/transmission , Homozygote , Humans , Methionine/chemistry , Methionine/genetics , PrPSc Proteins/chemistry , PrPSc Proteins/genetics , PrPSc Proteins/metabolism , Prion Proteins/chemistry , Protein Folding , Valine/chemistry , Valine/genetics
8.
J Virol ; 89(7): 3939-46, 2015 Apr.
Article in English | MEDLINE | ID: mdl-25609817

ABSTRACT

UNLABELLED: The genotype at polymorphic codon 129 of the PRNP gene has a profound influence on both phenotypic expression and prion strain susceptibility in humans. For example, while the most common sporadic Creutzfeldt-Jakob disease (CJD) subtype, sporadic CJD-MM1 (M1 strain), induces a single phenotype after experimental transmission regardless of the codon 129 genotype of the recipient animal, the phenotype elicited by sporadic CJD-VV2 (V2 strain), the second most common subtype, varies according to the host codon 129 genotype. In particular, the propagation of the V2 strain in codon 129 methionine homozygotes has been linked only to acquired forms of CJD such as plaque-type dura mater graft-associated CJD (dCJD), a subgroup of iatrogenic CJD with distinctive phenotypic features, but has never been observed in sporadic CJD cases. In the present report, we describe atypical CJD cases carrying codon 129 methionine homozygosity, in a neurosurgeon and in a patient with a medical history of neurosurgery without dural grafting, showing the distinctive phenotypic features and transmission properties of plaque-type dCJD. These findings raise the possibility that the two cases, previously thought to represent sporadic CJD, might actually represent acquired CJD caused by infection with the V2 strain. Thus, careful analyses of phenotypic features and transmission properties in atypical cases may be useful to distinguish acquired from sporadic cases of CJD. IMPORTANCE: Susceptibility to and phenotypic expression of Creutzfeldt-Jakob disease (CJD) depend on both the prion strain and genotype at polymorphic codon 129 of the PRNP gene. For example, propagation of the second most common sporadic CJD strain (V2 strain) into codon 129 methionine homozygotes has been linked to plaque-type dura mater graft-associated CJD (dCJD), a subgroup of iatrogenic CJD with distinctive phenotypic features, but has never been observed in sporadic CJD. In the present report, we describe atypical CJD cases in a neurosurgeon and in a patient with a medical history of neurosurgery without dural grafting, showing the distinctive phenotypic features and transmission properties of plaque-type dCJD. These findings raise the possibility that the two cases, previously considered to represent sporadic CJD, might actually represent acquired CJD caused by infection with the V2 strain.


Subject(s)
Creutzfeldt-Jakob Syndrome/transmission , Iatrogenic Disease , Prions/genetics , Prions/metabolism , Surgeons , Aged , Animals , Creutzfeldt-Jakob Syndrome/pathology , Disease Models, Animal , Female , Homozygote , Humans , Male , Methionine/genetics , Mice , Middle Aged , Mutant Proteins/genetics , Mutant Proteins/metabolism , Mutation, Missense , Neurosurgical Procedures/adverse effects , Occupational Exposure , Prion Proteins
9.
Histochem Cell Biol ; 146(3): 301-9, 2016 Sep.
Article in English | MEDLINE | ID: mdl-27109495

ABSTRACT

The dystrophin gene consists of 79 exons and encodes tissue-specific isoforms. Mutations in the dystrophin gene cause Duchenne muscular dystrophy, of which a substantial proportion of cases are complicated by non-progressive mental retardation. Abnormalities of Dp71, an isoform transcribed from a promoter in intron 62, are a suspected cause of mental retardation. However, the roles of Dp71 in human brain have not been fully elucidated. Here, we characterized dystrophin in human HEK293 cells with the neuronal lineage. Reverse transcription-PCR amplification of the full-length dystrophin transcript revealed the absence of fragments covering the 5' part of the dystrophin cDNA. In contrast, fragments covering exons 64-79 were present. The Dp71 promoter-specific exon G1 was shown spliced to exon 63. We demonstrated that the Dp71 transcript comprised two subisoforms: one lacking exon 78 (Dp71b) and the other lacking both exons 71 and 78 (Dp71ab). Western blotting of cell lysates using an antibody against the dystrophin C-terminal region revealed two bands, corresponding to Dp71b and Dp71ab. Immunohistochemical examination with the dystrophin antibody revealed scattered punctate signals in the cytoplasm and the nucleus. Western blotting revealed one band corresponding to Dp71b in the cytoplasm and two bands corresponding to Dp71b and Dp71ab in the nucleus, with Dp71b being predominant. These results indicated that Dp71ab is a nucleus-specific subisoform. We concluded that Dp71, comprising Dp71b and Dp71ab, was expressed exclusively in HEK293 cells and that Dp71ab was specifically localized to the nucleus. Our findings suggest that Dp71ab in the nucleus contributes to the diverse functions of HEK293 cells.


Subject(s)
Cell Nucleus/metabolism , Dystrophin/genetics , Dystrophin/metabolism , Dystrophin/analysis , HEK293 Cells , Humans , Protein Isoforms/analysis , Protein Isoforms/genetics , Protein Isoforms/metabolism
10.
Transfusion ; 56(1): 223-30, 2016 Jan.
Article in English | MEDLINE | ID: mdl-26347231

ABSTRACT

BACKGROUND: To prevent the iatrogenic spread of variant Creutzfeldt-Jakob disease (vCJD) between humans via blood products or transfusion, highly sensitive in vitro screening tests are necessary. Protein misfolding cyclic amplification (PMCA) is one such candidate test. However, plasma has been reported to inhibit the PMCA reaction. Therefore, we investigated the cell-PMCA conditions that permit vCJD prion amplification in the presence of plasma. STUDY DESIGN AND METHODS: Cell-PMCA of vCJD samples was performed by adding various final concentrations of pooled plasma, citrate-phosphate-dextrose (CPD), albumin, globulin, or pooled plasma treated with ion exchangers. After heparin and plasma concentrations were optimized, multiround cell-PMCA was performed. RESULTS: When 1% to 50% of pooled plasma was added to heparinized cell-PMCA, amplification efficiency showed a double-peaked profile at less than 1% and 40% final plasma concentrations, indicating that plasma contains not only PMCA inhibitors but also promoters. Intravenous globulin did not inhibit cell-PMCA, but the protein G-bound fraction did. CPD, albumin-depleted plasma, and the unbound fraction of anion-exchange chromatography inhibited cell-PMCA, but albumin and the unbound fraction of the cation-exchange chromatography did not. The detection limit of abnormal prion protein in multiround cell-PMCA, when maintaining the final plasma concentration at 40% at each round, was 10(-10) dilutions of a vCJD brain specimen. CONCLUSION: We have established a novel cell-PMCA format in the presence of plasma without any pretreatment, where vCJD prion protein was amplified at comparable levels to that found without plasma. Our data suggest the feasibility of cell-PMCA as a practical blood test for vCJD prions.


Subject(s)
Biomarkers/metabolism , Blood Safety/methods , Creutzfeldt-Jakob Syndrome/diagnosis , Prions/blood , Creutzfeldt-Jakob Syndrome/blood , Hematologic Tests , Heparin , Humans , Plasma
11.
Hum Genet ; 134(9): 993-1001, 2015 Sep.
Article in English | MEDLINE | ID: mdl-26152642

ABSTRACT

Duchenne muscular dystrophy (DMD) is a progressive muscle wasting disease caused by mutations in the dystrophin gene. One-third of DMD cases are complicated by mental retardation. Here, we used reverse transcription PCR to analyze the pattern of dystrophin transcripts in neuronal SH-SY5Y cells. Among the three alternative promoters/first exons at the 5'-end, only transcripts containing the brain cortex-specific C1 exon could be amplified. The C-transcript appeared as two products: a major product of the expected size and a minor larger product that contained the cryptic exon 1a between exons C1 and 2. At the 3'-end there was complete exon 78 skipping. Together, these findings indicate that SH-SY5Y cells have neuron-specific characteristics with regard to both promoter activation and alternative splicing. We also revealed partial skipping of exons 9 and 71. Four amplified products were obtained from a fragment covering exons 36-41: a strong expected product, two weak products lacking either exon 37 or exon 38, and a second strong larger product with a 568-bp insertion between exons 40 and 41. The inserted sequence matched the 3'-end of intron 40 perfectly. We concluded that a cryptic splice site was activated in SH-SY5Y cells to create the novel, unusually large, exon 41e (751 bp). In total, we identified seven alternative splicing events in neuronal SH-SY5Y cells, and calculated that 32 dystrophin transcripts could be produced. Our results may provide clues in the analysis of transcriptype-phenotype correlations as regards mental retardation in DMD.


Subject(s)
Alternative Splicing , Dystrophin/genetics , Exons , Introns , Promoter Regions, Genetic , Base Sequence , Cell Line, Tumor , DNA Transposable Elements/genetics , Genomics , Humans , Molecular Sequence Data , Muscular Dystrophy, Duchenne/genetics , Mutation , Polymerase Chain Reaction , RNA Splice Sites/genetics , RNA, Messenger/genetics , RNA, Messenger/metabolism , Sequence Analysis, DNA
12.
J Hum Genet ; 60(6): 327-33, 2015 Jun.
Article in English | MEDLINE | ID: mdl-25833469

ABSTRACT

The dystrophin gene, which is mutated in Duchenne muscular dystrophy (DMD), comprises 79 exons that show multiple alternative splicing events. Intron retention, a type of alternative splicing, may control gene expression. We examined intron retention in dystrophin introns by reverse-transcription PCR from skeletal muscle, focusing on the nine shortest (all <1000 bp), because these are more likely to be retained. Only one, intron 40, was retained in mRNA; sequencing revealed insertion of a complete intron 40 (851 nt) between exons 40 and 41. The intron 40 retention product accounted for 1.2% of the total product but had a premature stop codon at the fifth intronic codon. Intron 40 retention was most strongly observed in the kidney (36.6%) and was not obtained from the fetal liver, lung, spleen or placenta. This indicated that intron retention is a tissue-specific event whose level varies among tissues. In two DMD patients, intron 40 retention was observed in one patient but not in the other. Examination of splicing regulatory factors revealed that intron 40 had the highest guanine-cytosine content of all examined introns in a 30-nt segment at its 3' end. Further studies are needed to clarify the biological role of intron 40-retained dystrophin mRNA.


Subject(s)
Dystrophin/genetics , Base Composition , Dystrophin/metabolism , Humans , Introns , Kidney/metabolism , Muscle, Skeletal/metabolism , Muscular Dystrophy, Duchenne/genetics , Organ Specificity , Protein Isoforms/genetics , Protein Isoforms/metabolism , RNA, Messenger/genetics , RNA, Messenger/metabolism
13.
Gastric Cancer ; 18(2): 262-70, 2015 Apr.
Article in English | MEDLINE | ID: mdl-24651981

ABSTRACT

BACKGROUND: Many malignant tumors consist of heterogeneous subpopulations of cells. This heterogeneity is associated with genetic characteristics. However, it remains unclear whether gene expression levels differ among specific sites of tumors in gastric cancer. METHODS: We studied differences in gene expression levels among specific sites of primary tumors and synchronous lymph node metastases, using formalin-fixed, paraffin-embedded specimens resected surgically from 48 patients with previously untreated advanced gastric cancer. Specimens were obtained by laser-captured microdissection from five regions: (1) nonneoplastic mucosa, (2) surface layer (mucosa) of the primary tumor (surface sections), (3) middle layer (submucosa) of the primary tumor (middle sections), (4) the deepest layer of the primary tumor (muscularis propria or deeper) at the site of deepest invasion (deep sections), and (5) level 1 synchronous lymph node metastasis (lymph node metastases). Expression levels of the following target genes were determined by quantitative real-time polymerase chain reaction: thymidylate synthase (TS), thymidine phosphorylase (TP), dihydropyrimidine dehydrogenase (DPD), epidermal growth factor receptor (EGFR), vascular endothelial growth factor (VEGF), and hypoxia-inducible factor-1α (HIF1α). RESULTS: TP, DPD, EGFR, and HIF1α gene expression levels were significantly higher in deep sections than in surface sections. TP, EGFR, VEGF, and HIF1α gene expression levels were significantly higher in lymph node metastases than in surface sections. TP, DPD, EGFR, VEGF, and HIF1α gene expression levels were positively correlated with the specific samples harvested from the tumors. CONCLUSIONS: Our results show that the expression levels of some genes in tumor cells can change in specific sites of tumors and can become higher in association with tumor progression.


Subject(s)
Adenocarcinoma/genetics , Biomarkers, Tumor/genetics , Gene Expression Regulation, Neoplastic , Neoplasms, Multiple Primary/genetics , Stomach Neoplasms/genetics , Adenocarcinoma/secondary , Adult , Aged , Female , Follow-Up Studies , Gene Expression Profiling , Humans , Lymphatic Metastasis , Male , Middle Aged , Neoplasm Invasiveness , Neoplasm Staging , Neoplasms, Multiple Primary/pathology , Oligonucleotide Array Sequence Analysis , Prognosis , RNA, Messenger/genetics , Real-Time Polymerase Chain Reaction , Retrospective Studies , Reverse Transcriptase Polymerase Chain Reaction , Stomach Neoplasms/pathology
14.
J Biol Chem ; 288(30): 21659-66, 2013 Jul 26.
Article in English | MEDLINE | ID: mdl-23792955

ABSTRACT

To date, all clinical variant Creutzfeldt-Jakob disease (vCJD) patients are homozygous for methionine at polymorphic codon 129 (129M/M) of the prion protein (PrP) gene. However, the appearance of asymptomatic secondary vCJD infection in individuals with a PRNP codon 129 genotype other than M/M and transmission studies using animal models have raised the concern that all humans might be susceptible to vCJD prions, especially via secondary infection. To reevaluate this possibility and to analyze in detail the transmission properties of vCJD prions to transgenic animals carrying distinct codon 129 genotype, we performed intracerebral inoculation of vCJD prions to humanized knock-in mice carrying all possible codon 129 genotypes (129M/M, 129M/V, or 129V/V). All humanized knock-in mouse lines were susceptible to vCJD infection, although the attack rate gradually decreased from 129M/M to 129M/V and to 129V/V. The amount of PrP deposition including florid/amyloid plaques in the brain also gradually decreased from 129M/M to 129M/V and to 129V/V. The biochemical properties of protease-resistant abnormal PrP in the brain and transmissibility of these humanized mouse-passaged vCJD prions upon subpassage into knock-in mice expressing bovine PrP were not affected by the codon 129 genotype. These results indicate that individuals with the 129V/V genotype may be more susceptible to secondary vCJD infection than expected and may lack the neuropathological characteristics observed in vCJD patients with the 129M/M genotype. Besides the molecular typing of protease-resistant PrP in the brain, transmission studies using knock-in mice carrying bovine PrP may aid the differential diagnosis of secondary vCJD infection, especially in individuals with the 129V/V genotype.


Subject(s)
Brain/metabolism , Codon/genetics , Creutzfeldt-Jakob Syndrome/genetics , Prions/genetics , Animals , Blotting, Western , Brain/pathology , Cattle , Creutzfeldt-Jakob Syndrome/metabolism , Creutzfeldt-Jakob Syndrome/transmission , Genetic Predisposition to Disease/genetics , Genotype , Humans , Immunohistochemistry , Injections, Intraventricular , Mice , Mice, Transgenic , Plaque, Amyloid/metabolism , Plaque, Amyloid/pathology , Prion Diseases/genetics , Prion Diseases/metabolism , Prions/administration & dosage , Prions/metabolism
15.
J Biol Chem ; 288(46): 33071-80, 2013 Nov 15.
Article in English | MEDLINE | ID: mdl-24085302

ABSTRACT

Mice have the ability to convert dietary phylloquinone (vitamin K1) into menaquinone-4 (vitamin K2) and store the latter in tissues. A prenyltransferase enzyme, UbiA prenyltransferase domain-containing 1 (UBIAD1), is involved in this conversion. There is evidence that UBIAD1 has a weak side chain cleavage activity for phylloquinone but a strong prenylation activity for menadione (vitamin K3), which has long been postulated as an intermediate in this conversion. Further evidence indicates that when intravenously administered in mice phylloquinone can enter into tissues but is not converted further to menaquinone-4. These findings raise the question whether phylloquinone is absorbed and delivered to tissues in its original form and converted to menaquinone-4 or whether it is converted to menadione in the intestine followed by delivery of menadione to tissues and subsequent conversion to menaquinone-4. To answer this question, we conducted cannulation experiments using stable isotope tracer technology in rats. We confirmed that the second pathway is correct on the basis of structural assignments and measurements of phylloquinone-derived menadione using high resolution MS analysis and a bioassay using recombinant UBIAD1 protein. Furthermore, high resolution MS and (1)H NMR analyses of the product generated from the incubation of menadione with recombinant UBIAD1 revealed that the hydroquinone, but not the quinone form of menadione, was an intermediate of the conversion. Taken together, these results provide unequivocal evidence that menadione is a catabolic product of oral phylloquinone and a major source of tissue menaquinone-4.


Subject(s)
Intestinal Mucosa/metabolism , Vitamin K 1/pharmacokinetics , Vitamin K 2/analogs & derivatives , Vitamin K 3/metabolism , Vitamins/pharmacokinetics , Animals , Dimethylallyltranstransferase/genetics , Dimethylallyltranstransferase/metabolism , Female , Male , Mice , Rats , Rats, Sprague-Dawley , Recombinant Proteins/genetics , Recombinant Proteins/metabolism , Species Specificity , Vitamin K 1/pharmacology , Vitamin K 2/metabolism , Vitamins/pharmacology
16.
Sci Rep ; 14(1): 6506, 2024 03 18.
Article in English | MEDLINE | ID: mdl-38499569

ABSTRACT

Pathogenic variants in WDR45 on chromosome Xp11 cause neurodegenerative disorder beta-propeller protein-associated neurodegeneration (BPAN). Currently, there is no effective therapy for BPAN. Here we report a 17-year-old female patient with BPAN and show that antisense oligonucleotide (ASO) was effective in vitro. The patient had developmental delay and later showed extrapyramidal signs since the age of 15 years. MRI findings showed iron deposition in the globus pallidus and substantia nigra on T2 MRI. Whole genome sequencing and RNA sequencing revealed generation of pseudoexon due to inclusion of intronic sequences triggered by an intronic variant that is remote from the exon-intron junction: WDR45 (OMIM #300526) chrX(GRCh37):g.48935143G > C, (NM_007075.4:c.235 + 159C > G). We recapitulated the exonization of intron sequences by a mini-gene assay and further sought antisense oligonucleotide that induce pseudoexon skipping using our recently developed, a dual fluorescent splicing reporter system that encodes two fluorescent proteins, mCherry, a transfection marker designed to facilitate evaluation of exon skipping and split eGFP, a splicing reaction marker. The results showed that the 24-base ASO was the strongest inducer of pseudoexon skipping. Our data presented here have provided supportive evidence for in vivo preclinical studies.


Subject(s)
Oligonucleotides, Antisense , RNA Splicing , Female , Humans , Adolescent , Oligonucleotides, Antisense/genetics , Oligonucleotides, Antisense/pharmacology , Mutation , Exons/genetics , Carrier Proteins/genetics
17.
Ann Hum Genet ; 77(5): 435-63, 2013 Sep.
Article in English | MEDLINE | ID: mdl-23879295

ABSTRACT

Spinal muscular atrophy (SMA) is a common neuromuscular disorder with autosomal recessive inheritance, resulting in the degeneration of motor neurons. The incidence of the disease has been estimated at 1 in 6000-10,000 newborns with a carrier frequency of 1 in 40-60. SMA is caused by mutations of the SMN1 gene, located on chromosome 5q13. The gene product, survival motor neuron (SMN) plays critical roles in a variety of cellular activities. SMN2, a homologue of SMN1, is retained in all SMA patients and generates low levels of SMN, but does not compensate for the mutated SMN1. Genetic analysis demonstrates the presence of homozygous deletion of SMN1 in most patients, and allows screening of heterozygous carriers in affected families. Considering high incidence of carrier frequency in SMA, population-wide newborn and carrier screening has been proposed. Although no effective treatment is currently available, some treatment strategies have already been developed based on the molecular pathophysiology of this disease. Current treatment strategies can be classified into three major groups: SMN2-targeting, SMN1-introduction, and non-SMN targeting. Here, we provide a comprehensive and up-to-date review integrating advances in molecular pathophysiology and diagnostic testing with therapeutic developments for this disease including promising candidates from recent clinical trials.


Subject(s)
Muscular Atrophy, Spinal/genetics , Muscular Atrophy, Spinal/therapy , SMN Complex Proteins/genetics , Animals , Clinical Trials as Topic , Gene Dosage , Genetic Testing , Humans , Muscular Atrophy, Spinal/diagnosis , Mutation , SMN Complex Proteins/metabolism
18.
Biosci Biotechnol Biochem ; 77(9): 1809-13, 2013.
Article in English | MEDLINE | ID: mdl-24018671

ABSTRACT

Bunching onion [Allium fistulosum L. (Liliaceae)] secretes mucus in the cavities of its green leaves. The effects of the mucus, which is consumed as food, were examined. The mucus augmented the production of tumor necrosis factor (TNF)-α and monocyte chemotactic protein (MCP)-1 from RAW 264 cells and of interleukin (IL)-12 from J774.1 cells; however, extracts from green leaves and white sheaths did not. An oral administration of this mucus to mice augmented the immune functions of peritoneal cells by increasing TNF-α and IL-12 production and phagocytosis. It also augmented interferon (IFN)-γ production from spleen cells and natural killer (NK) activity. These results suggest that an oral administration of the A. fistulosum mucus can enhance natural immunity.


Subject(s)
Allium/chemistry , Immunologic Factors/administration & dosage , Immunologic Factors/pharmacology , Plant Extracts/administration & dosage , Plant Extracts/pharmacology , Administration, Oral , Animals , Cell Line , Interleukin-12/biosynthesis , Macrophages/drug effects , Macrophages/immunology , Macrophages/metabolism , Male , Mice , Mice, Inbred ICR , Plant Leaves/chemistry , Tumor Necrosis Factor-alpha/biosynthesis
19.
Heliyon ; 9(3): e13974, 2023 Mar.
Article in English | MEDLINE | ID: mdl-36915552

ABSTRACT

The polymorphic heterozygosity of PRNP at codon 129 or 219 prevents the onset of sporadic Creutzfeldt-Jakob disease (sCJD). We investigated the association between polymorphic genotypes at codon 129 or 219 and comprehensive prion disease onset using non-CJD as a reference. EK heterozygotes at codon 219, versus EE homozygotes, showed a preventive effect on the extensive prion diseases-sCJD, genetic CJD (gCJD) with V180I or M232R mutation, and Gerstmann-Straussler-Scheinker disease with P102L mutation. No preventive effect was observed for E200K-gCJD and dura-grafted CJD (dCJD) in 129 MV and 219 EK heterozygotes. It was suggested that unlike other prion diseases, E200K-gCJD may not benefit from the preventive effect of 219 EK heterozygosity because complementary electrostatic interactions between PrP molecules at K200 and E219 might make homodimer formation easier. Comparison of sCJD and dCJD indicates that 219 EK heterozygosity strongly inhibits de novo synthesis of PrPSc (initial PrPSc formation), but does not inhibit accelerated propagation of existing PrPSc.

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