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1.
Chem Pharm Bull (Tokyo) ; 68(1): 91-95, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31902904

RESUMO

Magnolia Flower is a crude drug used for the treatment of headaches, toothaches, and nasal congestion. Here, we focused on Magnolia kobus, one of the botanical origins of Magnolia Flower, and collected the flower parts at different growth stages to compare chemical compositions and investigate potential inhibitory activities against interleukin-2 (IL-2) production in murine splenic T cells. After determining the structures, we examined the inhibitory effects of the constituents of the bud, the medicinal part of the crude drug, against IL-2 production. We first extracted the flower parts of M. kobus from the bud to fallen bloom stages and analysed the chemical compositions to identify the constituents characteristic to the buds. We found that the inhibitory activity of the buds against IL-2 production was more potent than that of the blooms. We isolated two known compounds, tiliroside (1) and syringin (2), characteristic to the buds from the methanol (MeOH) extract of Magnolia Flower. Moreover, we examined the inhibitory activities of both compounds against IL-2 production and found that tiliroside (1) but not syringin (2), showed strong inhibitory activity against IL-2 production and inhibited its mRNA expression. Thus, our strategy to examine the relationship between chemical compositions and biological activities during plant maturation could not only contribute to the scientific evaluation of medicinal parts of crude drugs but also assist in identifying biologically active constituents that have not yet been reported.


Assuntos
Interleucina-2/metabolismo , Magnolia/química , Extratos Vegetais/química , Animais , Linhagem Celular , Flavonoides/química , Flavonoides/isolamento & purificação , Flavonoides/farmacologia , Flores/química , Flores/metabolismo , Glucosídeos/química , Glucosídeos/isolamento & purificação , Glucosídeos/farmacologia , Interleucina-2/genética , Magnolia/metabolismo , Camundongos , Fenilpropionatos/química , Fenilpropionatos/isolamento & purificação , Fenilpropionatos/farmacologia , Linfócitos T/citologia , Linfócitos T/efeitos dos fármacos , Linfócitos T/metabolismo
3.
Sci Rep ; 9(1): 1903, 2019 Feb 13.
Artigo em Inglês | MEDLINE | ID: mdl-30760837

RESUMO

To elucidate the mechanisms of malignant progression of lower-grade glioma, molecular profiling using methylation array, whole-exome sequencing, and RNA sequencing was performed for 122, 36 and 31 gliomas, respectively. This cohort included 24 matched pairs of initial lower-grade gliomas and recurrent tumors, most of which showed malignant progression. Nearly half of IDH-mutant glioblastomas that had progressed from lower-grade gliomas exhibited characteristic partial DNA demethylation in previously methylated genomic regions of their corresponding initial tumors, which had the glioma CpG island methylator phenotype (G-CIMP). In these glioblastomas, cell cycle-related genes, RB and PI3K-AKT pathway genes were frequently altered. Notably, late-replicating domain was significantly enriched in the demethylated regions that were mostly located in non-regulatory regions, suggesting that the loss of DNA methylation during malignant transformation may involve mainly passive demethylation due to a delay in maintenance of methylation during accelerated cell division. Nonetheless, a limited number of genes including IGF2BP3, which potentially drives cell proliferation, were presumed to be upregulated due to demethylation of their promoter. Our data indicated that demethylation of the G-CIMP profile found in a subset of recurrent gliomas reflects accelerated cell divisions accompanied by malignant transformation. Oncogenic genes activated by such epigenetic change represent potential therapeutic targets.

4.
Acta Neuropathol ; 134(6): 941-956, 2017 12.
Artigo em Inglês | MEDLINE | ID: mdl-28852847

RESUMO

Recent studies have demonstrated that tumor-driving alterations are often different among gliomas that originated from different brain regions and have underscored the importance of analyzing molecular characteristics of gliomas stratified by brain region. Therefore, to elucidate molecular characteristics of diffuse cerebellar gliomas (DCGs), 27 adult, mostly glioblastoma cases were analyzed. Comprehensive analysis using whole-exome sequencing, RNA sequencing, and Infinium methylation array (n = 17) demonstrated their distinct molecular profile compared to gliomas in other brain regions. Frequent mutations in chromatin-modifier genes were identified including, noticeably, a truncating mutation in SETD2 (n = 4), which resulted in loss of H3K36 trimethylation and was mutually exclusive with H3F3A K27M mutation (n = 3), suggesting that epigenetic dysregulation may lead to DCG tumorigenesis. Alterations that cause loss of p53 function including TP53 mutation (n = 9), PPM1D mutation (n = 2), and a novel type of PPM1D fusion (n = 1), were also frequent. On the other hand, mutations and copy number changes commonly observed in cerebral gliomas were infrequent. DNA methylation profile analysis demonstrated that all DCGs except for those with H3F3A mutations were categorized in the "RTK I (PDGFRA)" group, and those DCGs had a gene expression signature that was highly associated with PDGFRA. Furthermore, compared with the data of 315 gliomas derived from different brain regions, promoter methylation of transcription factors genes associated with glial development showed a characteristic pattern presumably reflecting their tumor origin. Notably, SOX10, a key transcription factor associated with oligodendroglial differentiation and PDGFRA regulation, was up-regulated in both DCG and H3 K27M-mutant diffuse midline glioma, suggesting their developmental and biological commonality. In contrast, SOX10 was silenced by promoter methylation in most cerebral gliomas. These findings may suggest potential tailored targeted therapy for gliomas according to their brain region, in addition to providing molecular clues to identify the region-related cellular origin of DCGs.


Assuntos
Neoplasias Cerebelares/genética , Neoplasias Cerebelares/metabolismo , Glioma/genética , Glioma/metabolismo , Adulto , Idoso , Idoso de 80 Anos ou mais , Neoplasias Cerebelares/patologia , Neoplasias Cerebelares/cirurgia , Cerebelo/diagnóstico por imagem , Cerebelo/metabolismo , Cerebelo/patologia , Cerebelo/cirurgia , Epigênese Genética , Regulação Neoplásica da Expressão Gênica , Predisposição Genética para Doença , Glioma/patologia , Glioma/cirurgia , Humanos , Pessoa de Meia-Idade
5.
J Am Chem Soc ; 138(43): 14178-14181, 2016 11 02.
Artigo em Inglês | MEDLINE | ID: mdl-27766835

RESUMO

5-Hydroxymethylcytosine (hmC) is an essential intermediate in the active DNA demethylation pathway. Here we report a new base-resolution method for measuring hmC by combining peroxotungstate-mediated oxidation and sequencing analysis. We reveal that an oxidized product of hmC, trihydroxylated thymine (thT), tolerated the incorporation of dATP as a substrate in the process of DNA polymerase elongation. By comparing the results of Sanger sequencing before and after the oxidation, we observed that hmC sites on single-stranded DNAs could be discriminated from unmethylated cytosines. We found that a thermal cycle condition during peroxotungstate treatment enhanced the oxidation reaction of hmC in double-stranded DNA. Furthermore, Illumina sequencing analysis of hmC-containing synthetic genome fragments enabled us to identify simultaneously the positions of hmC in base resolution. This bisulfite-free simple hmC detection technique could facilitate the acquisition of epigenomic information.


Assuntos
5-Metilcitosina/análogos & derivados , Compostos de Tungstênio/química , 5-Metilcitosina/química , Pareamento de Bases , Sequência de Bases , DNA/química , DNA/genética , Radioisótopos de Selênio , Sulfitos/química
6.
Hum Mol Genet ; 19(5): 761-73, 2010 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-19966329

RESUMO

Copy number variations (CNVs) are universal genetic variations, and their association with disease has been increasingly recognized. We designed high-density microarrays for CNVs, and detected 3000-4000 CNVs (4-6% of the genomic sequence) per population that included CNVs previously missed because of smaller sizes and residing in segmental duplications. The patterns of CNVs across individuals were surprisingly simple at the kilo-base scale, suggesting the applicability of a simple genetic analysis for these genetic loci. We utilized the probabilistic theory to determine integer copy numbers of CNVs and employed a recently developed phasing tool to estimate the population frequencies of integer copy number alleles and CNV-SNP haplotypes. The results showed a tendency toward a lower frequency of CNV alleles and that most of our CNVs were explained only by zero-, one- and two-copy alleles. Using the estimated population frequencies, we found several CNV regions with exceptionally high population differentiation. Investigation of CNV-SNP linkage disequilibrium (LD) for 500-900 bi- and multi-allelic CNVs per population revealed that previous conflicting reports on bi-allelic LD were unexpectedly consistent and explained by an LD increase correlated with deletion-allele frequencies. Typically, the bi-allelic LD was lower than SNP-SNP LD, whereas the multi-allelic LD was somewhat stronger than the bi-allelic LD. After further investigation of tag SNPs for CNVs, we conclude that the customary tagging strategy for disease association studies can be applicable for common deletion CNVs, but direct interrogation is needed for other types of CNVs.


Assuntos
Variações do Número de Cópias de DNA , Genoma Humano , Dosagem de Genes , Frequência do Gene , Genética Populacional , Haplótipos , Humanos , Desequilíbrio de Ligação , Polimorfismo de Nucleotídeo Único , Grupos Populacionais/genética
7.
Theor Popul Biol ; 70(3): 289-99, 2006 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-16828136

RESUMO

The aim of this article is to investigate the distribution of the coalescence time (T) for sampled genes in the structured coalescent. We obtain some exact solutions for small samples and approximate distributions for n sampled genes in strong and weak migration. We also conduct computer simulation to evaluate efficiencies of these approximations and show the dependency of the distribution of the coalescence time on the geographical structure and the intensity of migration. In a panmictic population, we prove that the conditional distribution of the coalescence time given the number of segregating sites (S) among sampled genes is given by the weighted mean of the convolution of gamma distributions. We also study the joint distribution of T and S in the structured coalescent model and show some exact solutions.


Assuntos
Frequência do Gene/genética , Modelos Genéticos , Seleção Genética , Análise de Variância , Evolução Biológica , Segregação de Cromossomos/genética , Simulação por Computador , Emigração e Imigração , Efeito Fundador , Genética Populacional , Geografia , Humanos , Cadeias de Markov , Mutação/genética , Linhagem , Distribuição de Poisson , Polimorfismo Genético/genética , Fatores de Tempo
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