117 research outputs found
Inter- and intra-specific gene-density-correlated radial chromosome territory arrangements are conserved in Old World monkeys
Recently it has been shown that the gene-density correlated radial distribution of human 18 and 19 homologous chromosome territories (CTs) is conserved in higher primates in spite of chromosomal rearrangements that occurred during evolution. However, these observations were limited to apes and New World monkey species. In order to provide further evidence for the evolutionary conservation of gene-density-correlated CT arrangements, we extended our previous study to Old World monkeys. They comprise the remaining species group to be analyzed in order to obtain a comprehensive overview of the nuclear topology of human 18 and 19 homologous CTs in higher primates. In the present study we investigated four lymphoblastoid cell lines from three species of Old World monkeys by three-dimensional fluorescence in situ hybridization (3D-FISH): two individuals of Japanese macaque ( Macaca fuscata), crab-eating macaque ( Macaca fascicularis), and an interspecies hybrid individual between African green monkey (Cercopithecus aethiops) and Patas monkey ( Erythrocebus patas). Our data demonstrate that gene-poor human 18 homologous CTs are located preferentially close to the nuclear periphery, whereas gene-dense human 19 homologous CTs are oriented towards the nuclear center in all cell lines analyzed. The gene-density-correlated positioning of human 18 and 19 homologous CTs is evolutionarily conserved throughout all major higher primate lineages, despite chromosomal inversions, fusions, fissions or reciprocal translocations that occurred in the course of evolution in these species. This remarkable preservation of a gene-density-correlated chromatin arrangement gives further support for a functionally relevant higher-order chromatin architecture. Copyright (C) 2005 S. Karger AG, Basel
An integrated analysis of hyponatremia in cancer patients receiving platinum-based or nonplatinum-based chemotherapy in clinical trials (JCOG1405-A)
Background: Hyponatremia is a common electrolyte abnormality in cancer patients who receive chemotherapy. Among anticancer agents, platinum-based agents are reported to cause chemotherapy-induced hyponatremia. However, the actual incidence and risk factors remain unknown. Results: The reports of 29 trials were analyzed. The incidence of grade 3/4 hyponatremia was 11.9% in patients treated with platinum-based chemotherapy and 3.8% in those treated with nonplatinum-based regimens (P < 0.01). Univariable analysis revealed a high incidence of hyponatremia in patients receiving cisplatin, three-drug combination regimen, two-drug combination regimen with amrubicin or irinotecan, or high-dose cisplatin (weekly equivalent cisplatin dose ≥20 mg/m²), and in patients with small-cell lung cancer. Conclusion: This is the first report of the actual incidence and the potential risk factors of chemotherapy-induced hyponatremia. Careful monitoring of serum sodium level is needed when platinum-based chemotherapy is administered. Methods: This study included all clinical trials of systemic chemotherapies for solid cancers that were conducted by the Japan Clinical Oncology Group (JCOG) after January 2000 and of which the patient enrolment was completed by January 2014. The latest reports of each trial were used for analysis. The incidence of chemotherapy-induced grade 3/4 hyponatremia and the potential risk factors were investigated with univariable analysis
Analysis of risk factors for mild cognitive impairment based on word list memory test results and questionnaire responses in healthy Japanese individuals registered in an online database
Although the development of effective therapeutic drugs and radical treatment options for dementia and Alzheimer’s disease (AD) remains urgent, progress in recent clinical trials of AD drugs has been less than adequate. In order to advance the progress of clinical trials, it is necessary to establish more efficient methods of recruitment. In Japan, there are registration systems stratified by mild cognitive impairment and preclinical and clinical stages of early and advanced stage dementia, but there is no registration system for healthy individuals yet. Therefore, in the present study, we developed a large-scale, internet-based health registry to investigate factors associated with cognitive function among registered participants. A total of 1038 participants completed the initial questionnaire and word list memory test. Among these participants, 353 individuals completed a second questionnaire and memory test. Stepwise multiple regression analysis was performed using IBM SPSS version 23.0 for Windows at a statistical significance level of p<0.05. We found that mood, motivation, and a decreased ability to perform activities of daily living were significantly associated with cognitive function. The results of the present study suggest that maintaining social involvement is important to prevent decreases in physical activity, daily function, mood, and motivation
Two distinct prions in fatal familial insomnia and its sporadic form
Abstract
Fatal familial insomnia is a genetic prion disease, which is associated with the aspartic acid to asparagine substitution at codon 178 of the prion protein gene. Although the hallmark pathological feature is thalamic and olivary degeneration, there is a patient with an atypical fatal familial insomnia without the hallmark feature. The cause of the pathological variability is unclear. We analysed a Japanese fatal familial insomnia kindred and compared one atypical clinicopathological fatal familial insomnia phenotype case and typical fatal familial insomnia phenotype cases with transmission studies using multiple lines of knock-in mice and with protein misfolding cyclic amplification. We also analysed the transmissibility and the amplification properties of sporadic fatal insomnia. Transmission studies revealed that the typical fatal familial insomnia with thalamic and olivary degeneration showed successful transmission only using knock-in mice expressing human–mouse chimeric prion protein gene. The atypical fatal familial insomnia with spongiform changes showed successful transmission only using knock-in mice expressing bank vole prion protein gene. Two sporadic fatal insomnia cases with thalamic and olivary degeneration showed the same transmissibility as the typical fatal familial insomnia phenotype. Interestingly, one sporadic fatal insomnia case with thalamic/olivary degeneration and spongiform changes showed transmissibility of both the typical and atypical fatal familial insomnia phenotypes. Protein misfolding cyclic amplification could amplify both typical fatal familial insomnia cases and sporadic fatal insomnia cases but not the atypical fatal familial insomnia phenotype or other sporadic Creutzfeldt–Jakob disease subtypes. In addition to clinical findings and neuropathological features, the transmission properties and the amplification properties were different between the typical and atypical fatal familial insomnia phenotypes. It is suggested that two distinct prions were associated with the diversity in the fatal familial insomnia phenotype, and these two prions could also be detected in sporadic fatal insomnia
Disease-specific monoclonal antibodies targeting glutamate decarboxylase impair GABAergic neurotransmission and affect motor learning and behavioral functions
Autoantibodies to the smaller isoform of glutamate decarboxylase (GAD) can be found in patients with type 1 diabetes and a number of neurological disorders, including stiff-person syndrome, cerebellar ataxia and limbic encephalitis. The detection of disease-specific autoantibody epitopes led to the hypothesis that distinct GAD autoantibodies may elicit specific neurological phenotypes. We explored the in vitro/in vivo effects of well-characterized monoclonal GAD antibodies. We found that GAD autoantibodies present in patients with stiff person syndrome (n = 7) and cerebellar ataxia (n = 15) recognized an epitope distinct from that recognized by GAD autoantibodies present in patients with type 1 diabetes mellitus (n = 10) or limbic encephalitis (n = 4). We demonstrated that the administration of a monoclonal GAD antibody representing this epitope specificity; (1) disrupted in vitro the association of GAD with γ-Aminobutyric acid containing synaptic vesicles; (2) depressed the inhibitory synaptic transmission in cerebellar slices with a gradual time course and a lasting suppressive effect; (3) significantly decreased conditioned eyelid responses evoked in mice, with no modification of learning curves in the classical eyeblink-conditioning task; (4) markedly impaired the facilitatory effect exerted by the premotor cortex over the motor cortex in a paired-pulse stimulation paradigm; and (5) induced decreased exploratory behavior and impaired locomotor function in rats. These findings support the specific targeting of GAD by its autoantibodies in the pathogenesis of stiff-person syndrome and cerebellar ataxia. Therapies of these disorders based on selective removal of such GAD antibodies could be envisioned.SCOPUS: ar.jinfo:eu-repo/semantics/publishe
Heme Orientation of Cavity Mutant Hemoglobins (His F8 → Gly) in Either α or β Subunits: Circular Dichroism, 1H NMR, and Resonance Raman Studies
Native human adult hemoglobin (Hb A) has mostly normal orientation of heme, whereas recombinant Hb A (rHb A) expressed in E. coli contains both normal and reversed orientations of heme. Hb A with the normal heme exhibits positive circular dichroism (CD) bands at both the Soret and 260-nm regions, while rHb A with the reversed heme shows a negative Soret and decreased 260-nm CD bands. In order to examine involvement of the proximal histidine (His F8) of either α or β subunits in determining the heme orientation, we prepared two cavity mutant Hbs, rHb(αH87G) and rHb(βH92G), with substitution of glycine for His F8 in the presence of imidazole. CD spectra of both cavity mutant Hbs did not show a negative Soret band, but instead exhibited positive bands with strong intensity at the both Soret and 260-nm regions, suggesting that the reversed heme scarcely exists in the cavity mutant Hbs. We confirmed by 1H NMR and resonance Raman (RR) spectroscopies that the cavity mutant Hbs have mainly the normal heme orientation in both the mutated and native subunits. These results indicate that the heme Fe-His F8 linkage in both α and β subunits influences the heme orientation, and that the heme orientation of one type of subunit is related to the heme orientation of the complementary subunits to be the same. The present study showed that CD and RR spectroscopies also provided powerful tools for the examination of the heme rotational disorder of Hb A, in addition to the usual 1H NMR technique. Chirality 28:585–592, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.Embargo Period 24 month
eIF2α dephosphorylation and cell proliferation in CHO-K1 cells
GADD34 is a member of a growth arrest and DNA damage (GADD)-inducible gene family. Here, we established a novel Chinese hamster ovary (CHO-K1)-K1-derived cell line, CHO-K1-G34M, which carries a nonsense mutation (termed the Q525X mutation) in the GADD34 gene. The Q525X mutant protein lacks the C-terminal 66 amino acids required for GADD34 to bind to and activate protein phosphatase 1 (PP1). We investigated the effects of GADD34 with or without the Q525X mutation on the phosphorylation status of PP1 target proteins, including the α subunit of eukaryotic initiation factor 2 (eIF2α) and glycogen synthase kinase 3β (GSK3β). CHOK1-G34M cells had higher levels of eIF2α phosphorylation compared to the control CHO-K1-normal cells both in the presence and absence of endoplasmic reticulum stress. Overexpression of wild type GADD34 protein in CHOK1-normal cells largely reduced eIF2α phosphorylation, while overexpression of the Q525X mutant did not produce similar reductions. Meanwhile, neither wild type nor Q525X mutation of GADD34 affected the GSK3β phosphorylation status. GADD34 also did not affect the canonical Wnt signaling pathway downstream of GSK3β. Cell proliferation rates were higher, while expression levels of the cyclin dependent kinase inhibitor p21 were lower in CHO-K1-G34M cells compared to the CHO-K1-normal cells. The GADD34 Q525X mutant had a reduced ability to inhibit cell proliferation and enhance p21 expression of the CHO-K1-normal cells compared to the wild type GADD34 protein. These results suggest that the GADD34 protein C-terminal plays important roles in regulating not only eIF2α dephosphorylation but also cell proliferation in CHO-K1 cells
A hERG mutation E1039X produced a synergistic lesion on I <sub>Ks</sub> together with KCNQ1-R174C mutation in a LQTS family with three compound mutations
Congenital long QT syndrome (LQTS) caused by compound mutations is usually associated with more severe clinical phenotypes. We identified a LQTS family harboring three compound mutations in different genes (KCNQ1-R174C, hERG-E1039X and SCN5A-E428K). KCNQ1-R174C, hERG-E1039X and SCN5A-E428K mutations and/or relevant wild-type (WT) cDNAs were respectively expressed in mammalian cells. IKs-like, IKr-like, INa-like currents and the functional interaction between KCNQ1-R174C and hERG-E1039X channels were studied using patch-clamp and immunocytochemistry techniques. (1) Expression of KCNQ1-R174C alone showed no IKs. Co-expression of KCNQ1-WT + KCNQ1-R174C caused a loss-of-function in IKs and blunted the activation of IKs in response to isoproterenol. (2) Expression of hERG-E1039X alone and co-expression of hERG-WT + hERG-E1039X negatively shifted inactivation curves and decelerated the recovery time from inactivation. (3) Expression of SCN5A-E428K increased peak INa, but had no effect on late INa. (4) IKs and IKr interact, and hERG-E1039X caused a loss-of-function in IKs. (5) Immunocytochemical studies indicated that KCNQ1-R174C is trafficking defective and hERG-E1039X is defective in biosynthesis/degradation, but the abnormities were rescued by co-expression with WT. Thus, KCNQ1-R174C and hERG-E1039X disrupted IKs and IKr functions, respectively. The synergistic lesion, caused by KCNQ1-R174C and hERG-E1039X in IKs, is very likely why patients showed more severe phenotypes in the compound mutation case
Early Detection of Abnormal Prion Protein in Genetic Human Prion Diseases Now Possible Using Real-Time QUIC Assay
Introduction: The definitive diagnosis of genetic prion diseases (gPrD) requires pathological confirmation. To date, diagnosis has relied upon the finding of the biomarkers 14-3-3 protein and total tau (t-tau) protein in the cerebrospinal fluid (CSF), but many researchers have reported that these markers are not sufficiently elevated in gPrD, especially in Gerstmann-Sträussler-Scheinker syndrome (GSS). We recently developed a new in vitro amplification technology, designated "real-time quaking-induced conversion (RT-QUIC)", to detect the abnormal form of prion protein in CSF from sporadic Creutzfeldt-Jakob disease (sCJD) patients. In the present study, we aimed to investigate the presence of biomarkers and evaluate RT-QUIC assay in patients with gPrD, as the utility of RT-QUIC as a diagnostic tool in gPrD has yet to be determined. Method/Principal Findings: 56 CSF samples were obtained from gPrD patients, including 20 cases of GSS with P102L mutation, 12 cases of fatal familial insomnia (FFI; D178N), and 24 cases of genetic CJD (gCJD), comprising 22 cases with E200K mutation and 2 with V203I mutation. We subjected all CSF samples to RT-QUIC assay, analyzed 14-3-3 protein by Western blotting, and measured t-tau protein using an ELISA kit. The detection sensitivities of RT-QUIC were as follows: GSS (78%), FFI (100%), gCJD E200K (87%), and gCJD V203I (100%). On the other hand the detection sensitivities of biomarkers were considerably lower: GSS (11%), FFI (0%), gCJD E200K (73%), and gCJD V203I (67%). Thus, RT-QUIC had a much higher detection sensitivity compared with testing for biomarkers, especially in patients with GSS and FFI. Conclusion/Significance: RT-QUIC assay is more sensitive than testing for biomarkers in gPrD patients. RT-QUIC method would thus be useful as a diagnostic tool when the patient or the patient\u27s family does not agree to genetic testing, or to confirm the diagnosis in the presence of a positive result for genetic testing
- …