JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE
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2019
·Vol. 99
·期 8
·3785-3791
·
IF 2.422
Shan Hong,Shanshan Wang,He Cai,Songbai Liu
BACKGROUND Methylated derivatives of catechins have received great attention for health beneficial effects, especially antiallergic activity. However, the scarce natural abundance of methylated catechins limits further bioactive studies. The objective of this work was to investigate regiospecific methylation of the hydroxyls of (+)-catechin through a stepwise differentiation strategy based on electronic difference between the hydroxyl groups. RESULTS Selective methylation of the hydroxyls on different rings was realized by employing Meerwein salt as the methylation reagent. Preferential acylation of the phenolic hydroxyls on A and B rings allowed selective exposure of the aliphatic hydroxyl on C ring to methylation. The vicinal phenolic hydroxyls on B ring were preferentially methylated under mild basic condition due to the acidic properties. Methylation of the phenolic hydroxyls on A ring was achieved by sequential protection and deprotection operations. Finally, antioxidant activities of all the individual methylated (+)-catechins were explored by 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) assay. CONCLUSION Regiospecific methylation of the phenolic and aliphatic hydroxyls was systematically achieved under mild conditions. Preparation of all the individual methylated (+)-catechins was accomplished with a greener methylation reagent: nonvolatile Meerwein salt. This work laid a solid foundation for preparation of diverse O -methylated catechins for bioactivity studies. © 2019 Society of Chemical Industry
研究领域:
食品科学
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有机化学
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生物化学
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DOI
PubMed
高影响因子
ANALYTICAL CHEMISTRY
·
2017
·
IF 6.32
Jie Yu,Chan Cao,Yi-Tao Long
Detection of DNA methylation in real human serum is of great importance to push the development of clinical research and early diagnosis of human diseases. Herein, taking advantage of stable pore structure of aerolysin in a harsh environment, we distinguish methylated cytosine from cytosine using aerolysin nanopore in human serum. Since wild-type (WT) aerolysin enables high sensitivity detection of DNA, the subtle difference between methylated cytosine and cytosine could be measured directly without any specific designs. Methylated cytosine induced a population of I/I0 = 0.53 while cytosine was focused on I/I0 = 0.56. The dwell time of methylated cytosine (5.3 ± 0.1 ms) was much longer than that of cytosine (3.9 ± 0.1 ms), which improves the accuracy for the discrimination of the two oligomers. Moreover, the pore-membrane system could remain stable for more than 2 h and achieve the detection of methylated cytosine with zero-background signal in the presence of serum. Additionally, event frequency of methylated cytosine is in correspondence with the relative concentration and facilitate the quantification of methylation.
研究领域:
分子生物学
·
临床医学
·
纳米技术
✓ 已验证
DOI
高影响因子
BMC PLANT BIOLOGY
·
2025
·Vol. 25
·期 1
·1-19
·
IF 4.8
Zhang Xiaoxiao,Zhu Lili,Xu Zihan,Wang Zhimin,Dai Liping
Background DNA methylation plays a key role in regulating plant growth and development, secondary metabolism, and environmental adaptability and is affected by DNA methyltransferase (C5-MTase) and demethylase (dMTase). However, the response of C5-MTase and dMTase genes to abiotic stress in Isodon rubescens remains largely unknown. Results In this study, eight IrC5-MTase genes and five IrdMTase genes were identified within the genome of I. rubescens . The IrC5-MTases were phylogenetically divided into four subfamilies (CMT, DRM, MET and DNMT2), and the IrdMTase were divided into two subgroups (ROS and DML) on the basis sequence similarity, conserved motif and domain architecture. The IrC5-MTase and IrdMTase genes were unevenly distributed on 5 and 4 chromosomes, respectively. Cis‑acting element analysis revealed that the IrC5-MTase and IrdMTase genes were enriched with multiple light-, phytohormone- and stress-responsive elements. Importantly, the level of DNA methylation in I. rubescens was influenced by different 5-azacytidine (5-azaC) concentrations or light intensities but unaffected by different NaCl concentrations. Accordingly, the expression of IrC5-MTase and IrdMTase genes were significantly upregulated or downregulated in response to different concentrations of 5-azaC or amounts of light stress, however, no conspicuous differences were observed under different degrees of NaCl stress. Expression correlation analysis revealed that the expression of IrCMT2a , IrMET1 , and IrDML4 was most closely related to the DNA methylation level in I. rubescens . Conclusions Our results reveal the characteristics and differential expression of the IrC5-MTase and IrdMTase genes in response to 5-azaC, light or NaCl stresses and will facilitate future epigenetic studies in I. rubescens .
研究领域:
植物学
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遗传学
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表观遗传学
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产品关联
DOI
PubMed
高影响因子
APPLIED BIOCHEMISTRY AND BIOTECHNOLOGY
·
2024
·
IF 3.1
Chen Hua,Han Cailing,Ha Chunfang
Uterine corpus endometrial carcinoma (UCEC) is one of the most common gynecologic tumors. Due to the high recurrence and metastasis of UCEC, it is crucial for patients to find new biomarkers for diagnosis and therapy. In this study, R software and the TCGA database were used to screen candidate UCEC predictive markers. Western blot and RT-qPCR were performed to detect protein and mRNA expression of EXT1 in UCEC cell lines. In addition, MTT assay, flow cytometry, transwell assay, and wound healing assay were conducted to assess the cell viability, apoptosis, invasion, and migration in UCEC cells. Overlap-extension PCR technique was employed to construct the vector targeting the deletion of the methylated segment of EXT1. The results showed that a total of 11 candidate genes were obtained and EXT1 was identified as a potential target. The expression and methylation levels of EXT1 were both increased in UCEC tissues and cell lines, as well as elevated EXT1 was closely related to the poor prognosis of patients. Besides, the knockdown of EXT1 significantly inhibited the malignant biological behaviors in UCEC cells. Additionally, the current study also found that the deletion of 1559–2146 bp CpG island segment upregulated EXT1 expression and promoted malignant biological behaviors in UCEC cells. Furthermore, the presence of m7G RNA methylation in UCEC cells also was found. In conclusion, the methylation of EXT1 influenced the gene expression, thereby affecting the malignant biological behaviors in UCEC cells and regulating the pathological progression of UCEC. Graphical
研究领域:
肿瘤学
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分子生物学
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基因组学
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产品关联
DOI
PubMed
高影响因子
CARBOHYDRATE POLYMERS
·
2025
·
IF 12.5
Ye Li,Jia-Ning Gao,Jun Liang,Xin-Hua Zhu,Hai-Xue Kuang,Yong-Gang Xia
The accurate characterization of glycosyl linkages in complex carbohydrates is always a challenging task due to the occurrence of isomer diversity and the unavailability of known standards. Because of the significant difference between head and tail in structures, this article built a complete methylation analysis library based on partially methylated aldononitrile acetates (PMANs) for facilitated identification of complex glycosidic linkages in polysaccharides. This library covered full EI-MS spectra and detailed fragmentation behaviors of corresponding PMANs ascribed to 46 aldohexoses, 32 aldopentoses and 16 deoxyhexoses. Furthermore, the elute behaviors of these PMANs are summarized on two capillary columns ascribed to complementary polarities. It is quite benefit to elucidate the glycosyl linkages of polysaccharides for inexperienced researchers in this field. The newly established PMAN library has been conformed to be an effective and alternative strategy for glycosyl linkage analysis of polysaccharides.
研究领域:
分析化学
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糖生物学
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产品关联
DOI
PubMed
高影响因子
ANALYTICAL AND BIOANALYTICAL CHEMISTRY
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2025
·
IF 3.8
Li Yifei,Su Yanfei,Chen Zhengyu,Wu Jianxun,Zhang Weilai,Xu Chunming,Shi Quan,Zhang Linzhou
Comprehensive characterization of petroleum-derived sulfur compounds is crucial for researching and developing desulfurization catalysts, equipment, and processes. However, the complex composition and low concentration of sulfur compounds in oils make it challenging for molecular-level separation and characterization. In this work, sulfur compounds in the straight-run diesel fraction were selectively separated from the oil by the methylation/demethylation method, effectively yielding high-purity thiophenes and sulfides. Molecular-level compositional and structural characterization of sulfur compounds was accomplished through comprehensive two-dimensional gas chromatography (GC × GC) coupled with time-of-flight mass spectrometry. The separation significantly enhances the detection sensitivity for low-content sulfur compounds, thereby enabling a more comprehensive characterization of their molecular compositions and structures. Sulfur compounds with diverse skeletons and carbon numbers were tentatively characterized, including 1~3 cyclic sulfides, thiophenes, benzothiophenes, dihydrobenzothiophenes, dibenzothiophenes, tetrahydrodibenzothiophenes, phenanthrothiophenes, and benzonaphthothiophenes. Additionally, hundreds of individual sulfur compounds were characterized by mass spectrometry. Quantitative analysis for individual compounds and compound types was conducted using a flame ionization detector. Graphical
研究领域:
化学工程
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石油化学
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分析化学
✓ 已验证
DOI
PubMed
高影响因子
TOXICOLOGY AND INDUSTRIAL HEALTH
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2024
·
IF 1.7
Yuxin Wang,Yi Guo,Jiajia Ren,Qiling Liu,Chong Wang
Earlier research has demonstrated that developmental exposure to bisphenol A (BPA) has persistent impacts on both adult brain growth and actions. It has been suggested that BPA might obstruct the methylation coding of the genes in the brain. In this study, the methylation changes in the hippocampus tissue of male rat pups were examined following prenatal BPA exposure. Pregnant Sprague-Dawley rats were treated with either vehicle (tocopherol-stripped corn oil) or BPA (4, 40, or 400 μg/kg·body weight/day) throughout the entire duration of gestation and lactation. At 3 weeks of age, the male rat offspring were euthanized, and the hippocampus were dissected out for analysis. The expression levels of DNA methyltransferases (DNMT1, DNMT3A, and DNMT3B) and DNA demethylases (TET1, Gadd45a, Gadd45b, and Apobec1) were analyzed in the hippocampus by means of quantitative real-time polymerase chain reaction and Western blotting, respectively. The results showed that prenatal exposure to BPA upregulated the expression of enzymes associated with DNA methylation and demethylation processes in the hippocampus of male rat offspring. These findings suggest that prenatal exposure to a low dose of BPA could potentially disrupt the balance of methylation and demethylation in the hippocampus, thereby perturbing epigenetic modifications. This may represent a neurotoxicity mechanism of BPA.
研究领域:
神经科学
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表观遗传学
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毒理学
✓ 已验证
DOI
PubMed
高影响因子
ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY
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2019
·
IF 4.527
Fan Du,Peng Liu,Kai Wang,Zhaoguang Yang,Lin Wang
Uptake, translocation and speciation of As in rice plants have been investigated through hydroponic cultivations under stress from different As species. After germination, rice seedlings were treated with arsenite [As(III)], arsenate [As(V)], monomethylarsonic acid (MMA) or dimethylarsinic acid (DMA) at concentrations of 50, 100, 150, 200 and 250 μg/L for 24 days. Only inorganic As species were detected in the rice plants treated with As(III) or As(V), indicating that rice seedlings could not methylate inorganic As in hydroponic culture . As(V) in the rice roots was readily reduced to As(III) after uptake; thus, As(III) was the dominant species in the rice roots (>60%) and shoots (>80%) regardless of As(III) or As(V) treatment. The increased As(III) proportion in the nutrient solutions was due to the efflux of As(III) from the rice roots. MMA with relatively low stability in the blank nutrient solution was demethylated to As(III). Moreover, demethylation and methylation of MMA might occur simultaneously in rice plants. Specific proportions of MMA and AsB were observed in the rice roots treated with DMA, implying that MMA and AsB were the DMA metabolites in rice roots after detoxification.
研究领域:
植物学
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环境科学
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毒理学
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DOI
高影响因子
INFLAMMATION
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2019
·Vol. 42
·期 5
·1705-1718
·
IF 2.939
Chen Jing,Zhan Changsheng,Zhang Li,Zhang Ligang,Liu Yi,Zhang Yong,Du Hexi,Liang Chaozhao,Chen Xianguo
Treg cells are crucial for maintaining immune homeostasis in CP/CPPS, but the molecular mechanisms underlying the modulation of the function of Treg in CP/CPPS remain unclear. The main purpose of this study is to investigate the relationship between immunosuppressive function of Treg and the methylation level of Foxp3 promoter in experimental autoimmune prostatitis (EAP) mouse model. EAP model was induced by subcutaneous injecting prostate-steroid-binding protein (PSBP) and complete Freund’s adjuvant with NOD mice. Histological analysis revealed that EAP model was successfully induced. The expression of IFN-γ was increased, and TGF-β was decreased in the serum of EAP, respectively. The percentage of Tregs in splenic lymphocyte was increased in EAP. The suppressive ability of Tregs on Teffs was impaired in EAP. The methylation level of Foxp3 promoter was increased, and the expression of Foxp3 was decreased in EAP. By injection AZA which was DNA-methylation inhibitor into EAP mice, prostate inflammation was alleviated, expressions of TGF-β and Foxp3 were increased, and the suppressive function of Tregs was improved in vitro and in vivo . Thus, we concluded that aberrant increased methylation of Foxp3 promoter in Treg cells leads to the impaired suppressive function of Treg cells, exacerbating autoimmune inflammatory injury in EAP.
研究领域:
免疫学
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分子生物学
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自身免疫疾病
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表观遗传学
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DOI
PubMed
高影响因子
JOURNAL OF PHARMACEUTICAL AND BIOMEDICAL ANALYSIS
·
2019
·
IF 2.983
Yu Tang,Zhe Wang,Menglin Li,Ruiping Zhang,Jinlan Zhang
A rapid, sensitive and wide coverage ultra-high-performance liquid chromatography with tandem mass spectrometry (UHPLC-MS/MS) method has been developed and validated for the simultaneous quantitation of 14 alkylation DNA adducts in cell genomic DNA, RNA and cell contents isolated from the in vitro cultured human kidney cell line 293 T and the human liver cell line L02 exposed to 3 genotoxic reagents: N -methyl -N- nitrosourea (MNU), methyl methanesulfonate (MMS) and 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK). After exposure, DNA was isolated and directly hydrolysed under acid conditions or digested by enzymes to obtain the hydrolysates containing DNA alkylation adducts followed by optimization of the pretreatment method and chromatographic separation conditions. Quantification was performed on a Waters ACQUITY UPLC BEH Amide column (1.7 μm, 2.1 × 150 mm) using an electrospray ionization (ESI) source in positive mode by selective reaction monitoring (SRM) at the precursor to product ion transitions of 14 analytes. The method showed selectivity, good linearity (r＞0.9950), accuracy (82.1%–115%), and intra-day (RSD%＜14%) and inter-day (RSD%＜15%) precision for 14 analytes. The recoveries of two pretreatment methods were all more than 50.5%, and no relative matrix effects were observed. Additionally, the samples were stable after short-term storage at 20 ℃ for 2 h, at 4 ℃ for 48 h or one cycle of freeze-thaw at −80 ℃. The established UHPLC-MS/MS method was used to evaluate the changes in alkylation DNA adducts and epigenetic modification-related methylcytosine after exposure to genotoxic reagents. For the first time, the results demonstrated that 3 genotoxic reagents induced different total amounts of adducts in the following sequence: MMS ＞ NNK ＞ MNU, and showed significant differences in the ratios of 7MeG to 1MeA and 1MeG to 1MeA in the 293 T cell model. Meanwhile, 293 T and L02 cells revealed significantly different DNA adduct formation characteristics in the contents of 1MeG and 1MeA. The DNA adduct formation relationships between DNA, RNA, and cell contents were probed to predict cancer risk and potential genotoxic exposure. This approach could be used to investigate the DNA adducts, their formation and the relationship to the mutagenicity or carcinogenicity of genotoxic reagents in future studies.
研究领域:
毒理学
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分析化学
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分子生物学
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DOI
PubMed
高影响因子
MOLECULAR NUTRITION & FOOD RESEARCH
·
2013
·Vol. 57
·期 5
·877-885
·
IF 4.31
Zhong-Jian Chen,Yan-Qing Dai,Si-Si Kong,Fei-Feng Song,Li-Ping Li,Jian-Feng Ye,Ru-Wei Wang,Su Zeng,Hui Zhou,Hui-Di Jiang
Scope The study aimed to investigate the regioselectivity of methylation of luteolin (3′,4′,5,7-tetrahydroxyflavone) in human in vitro and in vivo. Methods and results Recombinant human catechol- O -methyltransferase (COMT) and human liver S9 were utilized to study the kinetics of meta (3′)- and para (4′)- methylation of luteolin, and urine samples from volunteers after giving a luteolin-containing formulation were collected to determine the ratio of para-/meta-production. The results showed luteolin favored a para-methylation, with a ratio of of para-/meta-production in CL int (1.43 in recombinant human COMT and 1.47 in human liver S9), which was contrary to the known substrates of COMT. However, the result of urine sample assay showed a preference of meta-methylation with a ratio of of para-/meta-production (0.460 ± 0.126). To elucidate the mechanism for different preference of methylation of luteolin in vitro and in vivo, metabolism stability of the meta- and para-methylated luteolin was evaluated in human liver microsomes and recombinant human CYP450s, which revealed that para-methylated luteolin was more easily demethylated by human CYP1A2 and CYP3A4/5 than meta-methylated luteolin. Conclusion Luteolin was a rare substrate of human COMT favoring a para-methylation, but further demethylation by human CYP1A2 and CYP3A4/5 caused a preference of accumulation in meta-methylated luteolin in vivo.
研究领域:
药理学
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生物化学
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分子生物学
✓ 已验证
DOI
PubMed
高影响因子
BIOCHEMICAL PHARMACOLOGY
·
2025
·
IF 5.6
Jing Zhang,Xuewei Yang,Xing Zhao,Gang Luo,Hong Jiang
Renal fibrosis is recognized as a critical pathway leading to end-stage renal disease in nearly all cases of chronic kidney disease (CKD). Analysis of the gene expression omnibus (GEO) database revealed that the transcription factor Krüppel-like factor 3 (KLF3) was elevated in kidney tissues of CKD patients, however, its specific role in CKD-associated renal fibrosis is yet to be deciphered. This study aimed to investigate the function of KLF3 on unilateral ureteral obstruction (UUO) mice and transforming growth factor-β1 (TGF-β1)-stimulated HK2 cells. Our data demonstrated that KLF3 was remarkably upregulated in the renal cortex of UUO mice and TGF-β1-treated HK-2 cells. We further confirmed that the upregulation of KLF3 was associated with its N6-methyladenosine (m6A) methylation modification. Knockdown of METTL14 reduced m6A methylation level of KLF3 and inhibited its mRNA stability. In vivo results suggested that KLF3 knockdown alleviated the pathological changes in renal tissues triggered by UUO. Additionally, KLF3 silencing mitigated renal fibrosis both in vivo and in vitro , as accompanied by decreased expression of Collagen I, Vimentin, α-SMA and Fibronectin. Mechanistically, KLF3 transcription activated dimethylarginine dimethylaminohydroxylase 2 (DDAH2) and upregulated its expression. Rescue experiments substantiated that DDAH2 overexpression eliminated the effect of KLF3 knockdown on renal fibrosis. Collectively, our findings suggest that inhibition of KLF3 may serve as a potential strategy to prevent CKD-associated renal fibrosis.
研究领域:
分子生物学
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肾脏病学
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产品关联
DOI
PubMed
高影响因子
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