ALKBH1 was recently discovered as a demethylase for DNA N6-methyladenine （N6-mA）, a new epigenetic modification, and interacts with the core transcriptional pluripotency network of embryonic stem cells. However, the...ALKBH1 was recently discovered as a demethylase for DNA N6-methyladenine （N6-mA）, a new epigenetic modification, and interacts with the core transcriptional pluripotency network of embryonic stem cells. However, the role of ALKBH1 and DNA N6-mA in regulating osteogenic differentiation is largely unknown. In this study, we demonstrated that the expression of ALKBH1 in human mesenchymal stem cells （MSCs） was upregulated during osteogenic induction. Knockdown of ALKBH1 increased the genomic DNA N6-mA levels and significantly reduced the expression of osteogenic-related genes, alkaline phosphatase activity, and mineralization. ALKBHl-depleted MSCs also exhibited a restricted capacity for bone formation in vivo. By contrast, the ectopic overexpression of ALKBH1 enhanced osteoblastic differentiation. Mechanically, we found that the depletion of ALKBH1 resulted in the accumulation of N6-mA on the promoter region of ATF4, which subsequently silenced ATF4 transcription. In addition, restoring the expression of ATP by adenovirus-mediated transduction successfully rescued osteogenic differentiation. Taken together, our results demonstrate that ALKBH1 is indispensable for the osteogenic differentiation of MSCs and indicate that DNA N6-mA modifications area new mechanism for the epigenetic regulation of stem cell differentiation.展开更多
Substituted imidazolinium salt,1,2-dimethyl-3-(p-methoxybenzenesulfonyl) imidazolinium iodide,as a tetrahydrofolate model in terms of the ability to transfer a substituted one-carbon unit (ethylidyne,nitromethylethyli...Substituted imidazolinium salt,1,2-dimethyl-3-(p-methoxybenzenesulfonyl) imidazolinium iodide,as a tetrahydrofolate model in terms of the ability to transfer a substituted one-carbon unit (ethylidyne,nitromethylethylidene),can react with a variety of mono-and bifunctional nucleophiles and lead to some carboline alkaloids and other heterocyclic compounds.展开更多
The most common and abundant DNA modification is 5-methylcytosine（5mC）,which has been well-established as an epigenetic mark regulating gene expression in eukaryotes（Jones,2012）.Another DNA modification N^6-methyl...The most common and abundant DNA modification is 5-methylcytosine（5mC）,which has been well-established as an epigenetic mark regulating gene expression in eukaryotes（Jones,2012）.Another DNA modification N^6-methyldeoxyadenosine（6mA）,previously reported as a widespread DNA methylation in prokaryotes.展开更多
Accumulating evidence in recent years indicates that DNA methylation(5-methyl-2-deoxycytidine,5-mdC) and hydroxymethylation(5-hydroxymethyl-2-deoxycytidine, 5-hmd C) have been implicated in various biological processe...Accumulating evidence in recent years indicates that DNA methylation(5-methyl-2-deoxycytidine,5-mdC) and hydroxymethylation(5-hydroxymethyl-2-deoxycytidine, 5-hmd C) have been implicated in various biological processes, and the aberrations of these DNA cytosine modifications is tightly associated with cancer. N6-methyl-2-deoxyadenosine(m~6dA), as a newly discovered epigenetic modification in genome of mammals, has been demonstrated to play vital regulatory roles in tumorigenesis. However, the content information of m~6dA in human tumor tissues is still limited and pan-cancer analysis of these DNA epigenetic modifications is lacked. Herein, we developed a sensitive and robust stable isotopediluted hydrophilic interaction liquid chromatography-tandem mass spectrometry(HILIC-MS/MS) method for accurate quantification of m~6dA, 5-mdC and 5-hmdC in genomic DNA from 82 pairs of human tumor tissues and matched tumor-adjacent normal tissues. The types of tumors included esophagus cancer, lung cancer, breast cancer, liver cancer, pancreatic cancer, gastric cancer, stromal tumor and colorectal cancer.Compared to the normal tissues, we revealed the level of m6dA was increased in tumor tissues of esophagus cancer, lung cancer and liver cancer, whereas the level of m~6dA was diminished in tumor tissues of pancreatic cancer and gastric cancer;while the contents of 5-mdC and 5-hmdC exhibited significant decrease in tumor tissues of most types of cancer. It is worth noting that we revealed, for the first time,the content of genomic m~6dA in pancreatic cancer, stromal tumor and colorectal cancer. The significant changes of these DNA epigenetic modifications indicate they may serve as indicators of cancers. In addition, this study will benefit for better understanding of the regulatory roles of these DNA epigenetic modifications in cancers.展开更多
基金supported by grants from the National Natural Science Foundation of China (No.81271178 and 81470777)
文摘ALKBH1 was recently discovered as a demethylase for DNA N6-methyladenine （N6-mA）, a new epigenetic modification, and interacts with the core transcriptional pluripotency network of embryonic stem cells. However, the role of ALKBH1 and DNA N6-mA in regulating osteogenic differentiation is largely unknown. In this study, we demonstrated that the expression of ALKBH1 in human mesenchymal stem cells （MSCs） was upregulated during osteogenic induction. Knockdown of ALKBH1 increased the genomic DNA N6-mA levels and significantly reduced the expression of osteogenic-related genes, alkaline phosphatase activity, and mineralization. ALKBHl-depleted MSCs also exhibited a restricted capacity for bone formation in vivo. By contrast, the ectopic overexpression of ALKBH1 enhanced osteoblastic differentiation. Mechanically, we found that the depletion of ALKBH1 resulted in the accumulation of N6-mA on the promoter region of ATF4, which subsequently silenced ATF4 transcription. In addition, restoring the expression of ATP by adenovirus-mediated transduction successfully rescued osteogenic differentiation. Taken together, our results demonstrate that ALKBH1 is indispensable for the osteogenic differentiation of MSCs and indicate that DNA N6-mA modifications area new mechanism for the epigenetic regulation of stem cell differentiation.
文摘Substituted imidazolinium salt,1,2-dimethyl-3-(p-methoxybenzenesulfonyl) imidazolinium iodide,as a tetrahydrofolate model in terms of the ability to transfer a substituted one-carbon unit (ethylidyne,nitromethylethylidene),can react with a variety of mono-and bifunctional nucleophiles and lead to some carboline alkaloids and other heterocyclic compounds.
基金supported by Recruitment program of Global Youth Expert of China (to X.G.)the Elite Youth Program of the Chinese Academy of Agricultural Science (to X.G.)the intramural research support from Biotechnology Research Institute, Chinese Academy of Agricultural Sciences
文摘The most common and abundant DNA modification is 5-methylcytosine（5mC）,which has been well-established as an epigenetic mark regulating gene expression in eukaryotes（Jones,2012）.Another DNA modification N^6-methyldeoxyadenosine（6mA）,previously reported as a widespread DNA methylation in prokaryotes.
基金financially supported by National Natural Science Foundation of China (No. 22176167)the Key R&D Program of Zhejiang Province (No. 2021C03125)Natural Science Foundation of Zhejiang Province (No. LY19B050007)。
文摘Accumulating evidence in recent years indicates that DNA methylation(5-methyl-2-deoxycytidine,5-mdC) and hydroxymethylation(5-hydroxymethyl-2-deoxycytidine, 5-hmd C) have been implicated in various biological processes, and the aberrations of these DNA cytosine modifications is tightly associated with cancer. N6-methyl-2-deoxyadenosine(m~6dA), as a newly discovered epigenetic modification in genome of mammals, has been demonstrated to play vital regulatory roles in tumorigenesis. However, the content information of m~6dA in human tumor tissues is still limited and pan-cancer analysis of these DNA epigenetic modifications is lacked. Herein, we developed a sensitive and robust stable isotopediluted hydrophilic interaction liquid chromatography-tandem mass spectrometry(HILIC-MS/MS) method for accurate quantification of m~6dA, 5-mdC and 5-hmdC in genomic DNA from 82 pairs of human tumor tissues and matched tumor-adjacent normal tissues. The types of tumors included esophagus cancer, lung cancer, breast cancer, liver cancer, pancreatic cancer, gastric cancer, stromal tumor and colorectal cancer.Compared to the normal tissues, we revealed the level of m6dA was increased in tumor tissues of esophagus cancer, lung cancer and liver cancer, whereas the level of m~6dA was diminished in tumor tissues of pancreatic cancer and gastric cancer;while the contents of 5-mdC and 5-hmdC exhibited significant decrease in tumor tissues of most types of cancer. It is worth noting that we revealed, for the first time,the content of genomic m~6dA in pancreatic cancer, stromal tumor and colorectal cancer. The significant changes of these DNA epigenetic modifications indicate they may serve as indicators of cancers. In addition, this study will benefit for better understanding of the regulatory roles of these DNA epigenetic modifications in cancers.
