The Experts below are selected from a list of 252 Experts worldwide ranked by ideXlab platform
Yinsheng Wang - One of the best experts on this subject based on the ideXlab platform.
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simultaneous quantification of methylated cytidine and adenosine in cellular and tissue rna by nano flow liquid chromatography tandem mass spectrometry coupled with the stable isotope dilution method
Analytical Chemistry, 2015Co-Authors: Nicholas J Amato, Pengcheng Wang, Sara J Mcgowan, Laura J Niedernhofer, Yinsheng WangAbstract:The rising interest in understanding the functions, regulation, and maintenance of the epitranscriptome calls for robust and accurate analytical methods for the identification and quantification of post-transcriptionally modified nucleosides in RNA. Monomethylations of cytidine and adenosine are common post-transcriptional modifications in RNA. Herein, we developed an LC–MS/MS/MS coupled with the stable isotope-dilution method for the sensitive and accurate quantifications of 5-Methylcytidine (m5C), 2′-O-methylcytidine (Cm), N6-methyladenosine (m6A), and 2′-O-methyladenosine (Am) in RNA isolated from mammalian cells and tissues. Our results showed that the distributions of m5C, Cm and Am are tissue-specific. In addition, the 2′-O-methylated ribonucleosides (Cm and Am) are present at higher levels than the corresponding methylated nucleobase products (m5C and m6A) in total RNA isolated from mouse brain, pancreas, and spleen but not mouse heart. We also found that the levels of m5C, Cm, and Am are significa...
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Simultaneous Quantification of Methylated Cytidine and Adenosine in Cellular and Tissue RNA by Nano-Flow Liquid Chromatography–Tandem Mass Spectrometry Coupled with the Stable Isotope-Dilution Method
Analytical chemistry, 2015Co-Authors: Nicholas J Amato, Pengcheng Wang, Sara J Mcgowan, Laura J Niedernhofer, Yinsheng WangAbstract:The rising interest in understanding the functions, regulation, and maintenance of the epitranscriptome calls for robust and accurate analytical methods for the identification and quantification of post-transcriptionally modified nucleosides in RNA. Monomethylations of cytidine and adenosine are common post-transcriptional modifications in RNA. Herein, we developed an LC–MS/MS/MS coupled with the stable isotope-dilution method for the sensitive and accurate quantifications of 5-Methylcytidine (m5C), 2′-O-methylcytidine (Cm), N6-methyladenosine (m6A), and 2′-O-methyladenosine (Am) in RNA isolated from mammalian cells and tissues. Our results showed that the distributions of m5C, Cm and Am are tissue-specific. In addition, the 2′-O-methylated ribonucleosides (Cm and Am) are present at higher levels than the corresponding methylated nucleobase products (m5C and m6A) in total RNA isolated from mouse brain, pancreas, and spleen but not mouse heart. We also found that the levels of m5C, Cm, and Am are significa...
Nicholas J Amato - One of the best experts on this subject based on the ideXlab platform.
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simultaneous quantification of methylated cytidine and adenosine in cellular and tissue rna by nano flow liquid chromatography tandem mass spectrometry coupled with the stable isotope dilution method
Analytical Chemistry, 2015Co-Authors: Nicholas J Amato, Pengcheng Wang, Sara J Mcgowan, Laura J Niedernhofer, Yinsheng WangAbstract:The rising interest in understanding the functions, regulation, and maintenance of the epitranscriptome calls for robust and accurate analytical methods for the identification and quantification of post-transcriptionally modified nucleosides in RNA. Monomethylations of cytidine and adenosine are common post-transcriptional modifications in RNA. Herein, we developed an LC–MS/MS/MS coupled with the stable isotope-dilution method for the sensitive and accurate quantifications of 5-Methylcytidine (m5C), 2′-O-methylcytidine (Cm), N6-methyladenosine (m6A), and 2′-O-methyladenosine (Am) in RNA isolated from mammalian cells and tissues. Our results showed that the distributions of m5C, Cm and Am are tissue-specific. In addition, the 2′-O-methylated ribonucleosides (Cm and Am) are present at higher levels than the corresponding methylated nucleobase products (m5C and m6A) in total RNA isolated from mouse brain, pancreas, and spleen but not mouse heart. We also found that the levels of m5C, Cm, and Am are significa...
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Simultaneous Quantification of Methylated Cytidine and Adenosine in Cellular and Tissue RNA by Nano-Flow Liquid Chromatography–Tandem Mass Spectrometry Coupled with the Stable Isotope-Dilution Method
Analytical chemistry, 2015Co-Authors: Nicholas J Amato, Pengcheng Wang, Sara J Mcgowan, Laura J Niedernhofer, Yinsheng WangAbstract:The rising interest in understanding the functions, regulation, and maintenance of the epitranscriptome calls for robust and accurate analytical methods for the identification and quantification of post-transcriptionally modified nucleosides in RNA. Monomethylations of cytidine and adenosine are common post-transcriptional modifications in RNA. Herein, we developed an LC–MS/MS/MS coupled with the stable isotope-dilution method for the sensitive and accurate quantifications of 5-Methylcytidine (m5C), 2′-O-methylcytidine (Cm), N6-methyladenosine (m6A), and 2′-O-methyladenosine (Am) in RNA isolated from mammalian cells and tissues. Our results showed that the distributions of m5C, Cm and Am are tissue-specific. In addition, the 2′-O-methylated ribonucleosides (Cm and Am) are present at higher levels than the corresponding methylated nucleobase products (m5C and m6A) in total RNA isolated from mouse brain, pancreas, and spleen but not mouse heart. We also found that the levels of m5C, Cm, and Am are significa...
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Tet-Mediated Formation of 5-Hydroxymethylcytosine in RNA
Journal of the American Chemical Society, 2014Co-Authors: Candace R. Guerrero, Nicholas J Amato, Na Zhong, Yunhua Liu, Shuo Liu, Qian Cai, Seung Gi Jin, Laura J NiedernhoferAbstract:Oxidation of 5-methylcytosine in DNA by ten-eleven translocation (Tet) family of enzymes has been demonstrated to play a significant role in epigenetic regulation in mammals. We found that Tet enzymes also possess the activity of catalyzing the formation of 5-hydroxymethylcytidine (5-hmrC) in RNA in vitro. In addition, the catalytic domains of all three Tet enzymes as well as full-length Tet3 could induce the formation of 5-hmrC in human cells. Moreover, 5-hmrC was present at appreciable levels (∼1 per 5000 5-Methylcytidine) in RNA of mammalian cells and tissues. Our results suggest the involvement of this oxidation in RNA biology.
Laura J Niedernhofer - One of the best experts on this subject based on the ideXlab platform.
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simultaneous quantification of methylated cytidine and adenosine in cellular and tissue rna by nano flow liquid chromatography tandem mass spectrometry coupled with the stable isotope dilution method
Analytical Chemistry, 2015Co-Authors: Nicholas J Amato, Pengcheng Wang, Sara J Mcgowan, Laura J Niedernhofer, Yinsheng WangAbstract:The rising interest in understanding the functions, regulation, and maintenance of the epitranscriptome calls for robust and accurate analytical methods for the identification and quantification of post-transcriptionally modified nucleosides in RNA. Monomethylations of cytidine and adenosine are common post-transcriptional modifications in RNA. Herein, we developed an LC–MS/MS/MS coupled with the stable isotope-dilution method for the sensitive and accurate quantifications of 5-Methylcytidine (m5C), 2′-O-methylcytidine (Cm), N6-methyladenosine (m6A), and 2′-O-methyladenosine (Am) in RNA isolated from mammalian cells and tissues. Our results showed that the distributions of m5C, Cm and Am are tissue-specific. In addition, the 2′-O-methylated ribonucleosides (Cm and Am) are present at higher levels than the corresponding methylated nucleobase products (m5C and m6A) in total RNA isolated from mouse brain, pancreas, and spleen but not mouse heart. We also found that the levels of m5C, Cm, and Am are significa...
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Simultaneous Quantification of Methylated Cytidine and Adenosine in Cellular and Tissue RNA by Nano-Flow Liquid Chromatography–Tandem Mass Spectrometry Coupled with the Stable Isotope-Dilution Method
Analytical chemistry, 2015Co-Authors: Nicholas J Amato, Pengcheng Wang, Sara J Mcgowan, Laura J Niedernhofer, Yinsheng WangAbstract:The rising interest in understanding the functions, regulation, and maintenance of the epitranscriptome calls for robust and accurate analytical methods for the identification and quantification of post-transcriptionally modified nucleosides in RNA. Monomethylations of cytidine and adenosine are common post-transcriptional modifications in RNA. Herein, we developed an LC–MS/MS/MS coupled with the stable isotope-dilution method for the sensitive and accurate quantifications of 5-Methylcytidine (m5C), 2′-O-methylcytidine (Cm), N6-methyladenosine (m6A), and 2′-O-methyladenosine (Am) in RNA isolated from mammalian cells and tissues. Our results showed that the distributions of m5C, Cm and Am are tissue-specific. In addition, the 2′-O-methylated ribonucleosides (Cm and Am) are present at higher levels than the corresponding methylated nucleobase products (m5C and m6A) in total RNA isolated from mouse brain, pancreas, and spleen but not mouse heart. We also found that the levels of m5C, Cm, and Am are significa...
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Tet-Mediated Formation of 5-Hydroxymethylcytosine in RNA
Journal of the American Chemical Society, 2014Co-Authors: Candace R. Guerrero, Nicholas J Amato, Na Zhong, Yunhua Liu, Shuo Liu, Qian Cai, Seung Gi Jin, Laura J NiedernhoferAbstract:Oxidation of 5-methylcytosine in DNA by ten-eleven translocation (Tet) family of enzymes has been demonstrated to play a significant role in epigenetic regulation in mammals. We found that Tet enzymes also possess the activity of catalyzing the formation of 5-hydroxymethylcytidine (5-hmrC) in RNA in vitro. In addition, the catalytic domains of all three Tet enzymes as well as full-length Tet3 could induce the formation of 5-hmrC in human cells. Moreover, 5-hmrC was present at appreciable levels (∼1 per 5000 5-Methylcytidine) in RNA of mammalian cells and tissues. Our results suggest the involvement of this oxidation in RNA biology.
E. Matthes - One of the best experts on this subject based on the ideXlab platform.
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Inhibition of hepatitis B virus production by modified 2',3'-dideoxy-thymidine and 2',3'-dideoxy-5-Methylcytidine derivatives. In vitro and in vivo studies.
Biochemical pharmacology, 1992Co-Authors: E. Matthes, M Von Janta-lipinski, Hans Will, H. C. Schröder, H. Merz, R. Steffen, W.e.g. MüllerAbstract:The effect of analogues of both 2',3'-dideoxy-3'-fluorothymidine (FddThd) [2',3'-dideoxy-3'-fluorouridine (FddUrd), 2',3'-dideoxy-3'-fluoro-5-chlorouridine (FddClUrd), 2',3'-dideoxy-3'-fluoro-5-bromouridine (FddBrUrd) and 2',3'-dideoxy-3'-fluoro-5-bromovinyluridine (FddBVUrd)] and 2',3'-dideoxy-3'-fluorocytidine (FddCyt) [2', 3'-dideoxy-3'-fluoro-5-fluorocytidine (FddFCyt), 2',3'-dideoxy-3'-nuoro-5-chlorocytidine (FddClCyt), 2',3'-dideoxy-3'-nuoro-5-Methylcytidine (FddMeCyt), 2',3'-dideoxy-3'-fluoro-5-ethylcytidine (FddEtCyt), 2',3'-dideoxy-3'-chloro-5-Methylcytidine (CIddMeCyt), 2 ' ,3 ' -dideoxy-3 ' -amino-5-Methylcytidine (AmddMeCyt), 2' ,3'-dideoxy-3' -azido-5-Methylcytidine (AzddMeCyt) and arabinosyl-5-methylcytosine (AraMeCyt)] were tested for their potential antiviral activity in vitro using the human hepatoblastoma cell line, Hep G2 2.2.15, which was transfected with a vector containing hepatitis B virus (HBV). It was found that FddThd, FddMeCyt, FddEtCyt, CIddMeCyt, AmddMeCyt and AraMeCyt display cytostatic activity at concentrations (CD50 values) between 0.54 (FddMeCyt) and 3.93 μM (FddEtCyt), while FddUrd, FddClUrd, FddBrUrd, FddBVUrd, FddCyt, FddFCyt, FddClCyt and AzddMeCyt do not affect cell growth at concentrations of up to 25 μM. Among the thymidine analogues tested, FddThd is the most effective antiviral agent: at a concentration of 0.03 μM a more than 90% reduction of HBV DNA synthesis was measured. On the other hand, the antiviral indexes displayed by FddClUrd, FddBrUrd and FddBVUrd are higher than that of FddThd; FddUrd was completely inactive. The most powerful antiviral agents in the group of cytidine analogues tested in vitro were FddMeCyt (more than 90% reduction of HBV DNA synthesis at 0.10 μM) and CIddMeCyt (0.10 μM); FddClCyt, FddEtCyt, AmddMeCyt and AraMeCyt were of intermediate activity. None or negligible antiviral activity was determined for FddUrd, FddCyt, FddFCyt and AzddMeCyt. FddThd and FddMeCyt displayed in vivo an antiviral effect in the duck/duck HBV (DHBV) animal system. Administration of 10 or 20 mg/kg (total daily dose) of FddThd and 5 or 10 mgkg of FddMeCyt (i.m. daily) to ducks infected with DHBV for 12 days blocked virus production. Termination of treatment with FddThd of infected animals led to reappearance of the virus in the serum though at lower levels. The in vitro and the in vivo data suggest that FddThd and FddMeCyt might be promising antiviral agents for the treatment of infection caused by HBV in humans.
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Comparative inhibition of hepatitis B virus DNA polymerase and cellular DNA polymerases by triphosphates of sugar-modified 5-methyldeoxycytidines and of other nucleoside analogs.
Antimicrobial agents and chemotherapy, 1991Co-Authors: E. Matthes, Karen Dr. Reimer, M Von Janta-lipinski, Helga Dr. Meisel, C LehmannAbstract:Of a series of 14 nucleoside 59-triphosphates, those of 29,39-dideoxy-39-fluoro-5-Methylcytidine, 39-azido-29,39-dideoxy-5-Methylcytidine, 29,39-dideoxy-39-fluoroguanosine, 29,39-didehydro-29,39-dideoxy-5-Methylcytidine, 29,39-dideoxy-39-fluoro-5-ethylcytidine, and 29,39-dideoxy-39-fluoroadenosine emerged as the most potent inhibitors of hepatitis B virus DNA polymerase (50% inhibitory dose, 0.03 to 0.35 microM). In contrast, cellular DNA polymerases proved to be resistant to (alpha) or partially affected by (beta) these analogs. These compounds are among the most effective and selective inhibitors of endogenous hepatitis B virus DNA polymerase recognized to date.
W.e.g. Müller - One of the best experts on this subject based on the ideXlab platform.
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Inhibition of hepatitis B virus production by modified 2',3'-dideoxy-thymidine and 2',3'-dideoxy-5-Methylcytidine derivatives. In vitro and in vivo studies.
Biochemical pharmacology, 1992Co-Authors: E. Matthes, M Von Janta-lipinski, Hans Will, H. C. Schröder, H. Merz, R. Steffen, W.e.g. MüllerAbstract:The effect of analogues of both 2',3'-dideoxy-3'-fluorothymidine (FddThd) [2',3'-dideoxy-3'-fluorouridine (FddUrd), 2',3'-dideoxy-3'-fluoro-5-chlorouridine (FddClUrd), 2',3'-dideoxy-3'-fluoro-5-bromouridine (FddBrUrd) and 2',3'-dideoxy-3'-fluoro-5-bromovinyluridine (FddBVUrd)] and 2',3'-dideoxy-3'-fluorocytidine (FddCyt) [2', 3'-dideoxy-3'-fluoro-5-fluorocytidine (FddFCyt), 2',3'-dideoxy-3'-nuoro-5-chlorocytidine (FddClCyt), 2',3'-dideoxy-3'-nuoro-5-Methylcytidine (FddMeCyt), 2',3'-dideoxy-3'-fluoro-5-ethylcytidine (FddEtCyt), 2',3'-dideoxy-3'-chloro-5-Methylcytidine (CIddMeCyt), 2 ' ,3 ' -dideoxy-3 ' -amino-5-Methylcytidine (AmddMeCyt), 2' ,3'-dideoxy-3' -azido-5-Methylcytidine (AzddMeCyt) and arabinosyl-5-methylcytosine (AraMeCyt)] were tested for their potential antiviral activity in vitro using the human hepatoblastoma cell line, Hep G2 2.2.15, which was transfected with a vector containing hepatitis B virus (HBV). It was found that FddThd, FddMeCyt, FddEtCyt, CIddMeCyt, AmddMeCyt and AraMeCyt display cytostatic activity at concentrations (CD50 values) between 0.54 (FddMeCyt) and 3.93 μM (FddEtCyt), while FddUrd, FddClUrd, FddBrUrd, FddBVUrd, FddCyt, FddFCyt, FddClCyt and AzddMeCyt do not affect cell growth at concentrations of up to 25 μM. Among the thymidine analogues tested, FddThd is the most effective antiviral agent: at a concentration of 0.03 μM a more than 90% reduction of HBV DNA synthesis was measured. On the other hand, the antiviral indexes displayed by FddClUrd, FddBrUrd and FddBVUrd are higher than that of FddThd; FddUrd was completely inactive. The most powerful antiviral agents in the group of cytidine analogues tested in vitro were FddMeCyt (more than 90% reduction of HBV DNA synthesis at 0.10 μM) and CIddMeCyt (0.10 μM); FddClCyt, FddEtCyt, AmddMeCyt and AraMeCyt were of intermediate activity. None or negligible antiviral activity was determined for FddUrd, FddCyt, FddFCyt and AzddMeCyt. FddThd and FddMeCyt displayed in vivo an antiviral effect in the duck/duck HBV (DHBV) animal system. Administration of 10 or 20 mg/kg (total daily dose) of FddThd and 5 or 10 mgkg of FddMeCyt (i.m. daily) to ducks infected with DHBV for 12 days blocked virus production. Termination of treatment with FddThd of infected animals led to reappearance of the virus in the serum though at lower levels. The in vitro and the in vivo data suggest that FddThd and FddMeCyt might be promising antiviral agents for the treatment of infection caused by HBV in humans.
