BACKGROUND Thrombocytopenia 2,an autosomal dominant inherited disease characterized by moderate thrombocytopenia,predisposition to myeloid malignancies and normal platelet size and function,can be caused by 5’-untran...BACKGROUND Thrombocytopenia 2,an autosomal dominant inherited disease characterized by moderate thrombocytopenia,predisposition to myeloid malignancies and normal platelet size and function,can be caused by 5’-untranslated region(UTR)point mutations in ankyrin repeat domain containing 26(ANKRD26).Runt related transcription factor 1(RUNX1)and friend leukemia integration 1(FLI1)have been identified as negative regulators of ANKRD26.However,the positive regulators of ANKRD26 are still unknown.AIM To prove the positive regulatory effect of GATA binding protein 2(GATA2)on ANKRD26 transcription.METHODS Human induced pluripotent stem cells derived from bone marrow(hiPSC-BM)INTRODUCTION Ankyrin repeat domain containing protein 26(ANKRD26)acts as a regulator of adipogenesis and is involved in the regulation of feeding behavior[1-3].The ANKRD26 gene is located on chromosome 10 and shares regions of homology with the primate-specific gene family POTE.According to the Human Protein Atlas database,the ANKRD26 protein is localized to the Golgi apparatus and vesicles,and its expression can be detected in nearly all human tissues[4].Moreover,UniProt annotation revealed that ANKRD26 is localized in the centrosome and contains coiled-coil domains formed by spectrin helices and ankyrin repeats[5,6].The most common disease related to ANKRD26 is thrombocytopenia 2(THC2),which is a rare autosomal dominant inherited disease characterized by lifelong mild-to-moderate thrombocytopenia and mild bleeding[7-9].Caused by the variants in the 5’-untranslated region(UTR)of ANKRD26,THC2 is defined by a decrease in the number of platelets in circulating blood and results in increased bleeding and decreased clotting ability[8,10].Due to the point mutations that occur in the 5’-UTR of ANKRD26,its negative transcription factors(TFs),Runt related transcription factor 1(RUNX1)and friend leukemia integration 1(FLI1),lose their repression effect[11].The persistent expression of ANKRD26 increases the activity of the mitogen activated protein kinase and extracellular signal regulated kinase 1/2 signaling pathways,which are potentially involved in the regulation of thrombopoietin-dependent signaling and further impair proplatelet formation by megakaryocytes(MKs)[11].However,the positive regulators of ANKRD26,which might be associated with THC2 pathology,are still unknown.展开更多
Summary： The role of methyl-CpG binding domain protein 2 （MBD2） in an ApoE-deficient mouse model of age-related macular degeneration （AMD） was investigated. Eight-week-old Mbd2/ApoE double deficient （Mbd2^-/- Ap...Summary： The role of methyl-CpG binding domain protein 2 （MBD2） in an ApoE-deficient mouse model of age-related macular degeneration （AMD） was investigated. Eight-week-old Mbd2/ApoE double deficient （Mbd2^-/- ApoE^-/-） mice （n=12, 24 eyes, experimental group） and MBD2 （wt） ApoE^-/- mice （n=12, 24 eyes, control group） were fed on Western-type diet for 4 months. The mice were sacrificed, and total serum cholesterol levels were analyzed and Bruch＇s membrane （BM） of the eyes was removed for ultrastructural observation by transmission electron microscopy. Moreover, intercellular adhesion molecule 1 （ICAM-1） immunoreactivities were evaluated by fluorescence microscopy in sections of the eyes in both groups for further understanding the function mechanism of MBD2. There was no significant difference in the total serum cholesterol levels between control group and experimental group （P〉0.05）. Transmission electron microscopy revealed that AMD-like lesions, various vacuoles accumulated on BM, notable outer collagenous layer deposits and dilated basal infoldings of retinal pigment epithelium （RPE） were seen in both groups, and the BM in control group was significantly thickened as compared with experimental group （P〈0.05）. Fluorescence micrographs exhibited the expression of ICAM-1 in choroid was higher in control group than in experimental group. We are led to conclude that MBD2 gene knockout may lead to accumulation of more deposits on the BM and influence the pathogenesis of AMD via triggering endothelial activation and inflammatory response in choroid, improving microcirculation, and reducing lipid deposition so as to inhibit the development of AMD-like lesions. Our study helps to provide a new therapeutic approach for the clinical treatment of AMD.展开更多
AIM:To investigate the reciprocal modulation between microRNA(miRNA) and DNA methylation via exploring the correlation between miR-373 and methyl-CpGbinding domain protein(MBD)2.METHODS:MiR-373 expression was examined...AIM:To investigate the reciprocal modulation between microRNA(miRNA) and DNA methylation via exploring the correlation between miR-373 and methyl-CpGbinding domain protein(MBD)2.METHODS:MiR-373 expression was examined using the TaqMan miRNA assay.Methylation of miR-373 was investigated using methylation-specific polymerase chain reaction,and recruitment of methyl binding proteins was studied using the chromatin immunoprecipitation assay.Mutation analysis was conducted using the QuikChange Site-Directed Mutagenesis kit.The activity of miR-373 gene promoter constructs and targeting at MBD2-three prime untranslated region(3'UTR) by miR-373 were evaluated by a dual-luciferase reporter gene assay.RESULTS:In hilar cholangiocarcinoma,miR-373 decreased and was closely associated with poor cell differentiation,advanced clinical stage,and shorter survival.The promoter-associated CpG island of miR-373 gene was hypermethylated and inhibited expression of miR-373.MBD2 was up-regulated and enriched at the promoter-associated CpG island of miR-373.Methylation-mediated suppression of miR-373 required MBD2 enrichment at the promoter-associated CpG island,and miR-373 negatively regulated MBD2 expression through targeting the 3'UTR.CONCLUSION:MiR-373 behaves as a direct transcriptional target and negative regulator of MBD2 activity through a feedback loop of CpG island methylation.展开更多
Caused by the mutation of methyl-CpG binding protein 2(MeCP2),Rett syndrome leads to a battery of severe neural dysfunctions including the regression of motor coordination and motor learning.Current understanding has ...Caused by the mutation of methyl-CpG binding protein 2(MeCP2),Rett syndrome leads to a battery of severe neural dysfunctions including the regression of motor coordination and motor learning.Current understanding has revealed the motor cortex as the critical region mediating voluntary movement.In this review article,we will summarize major findings from human patients and animal models regarding the cortical synaptic plasticity under the regulation of MeCP2.We will also discuss how mutation of MeCP2 leads to the disruption of cortical circuitry homeostasis to cause motor deficits.Lastly,potential values of physical exercise and neuromodulation approaches to recover neural plasticity and motor function will be evaluated.All of this evidence may help to accelerate timely diagnosis and effective interventions for Rett syndrome patients.展开更多
Methyl-CpG(mCpG)binding domain(MBD)proteins especially bind with methylated DNA,and are involved in many important biological processes;however,the binding mechanism between insect MBD2/3 and mCpG remains unclear.In t...Methyl-CpG(mCpG)binding domain(MBD)proteins especially bind with methylated DNA,and are involved in many important biological processes;however,the binding mechanism between insect MBD2/3 and mCpG remains unclear.In this study,we identified 2 isoforms of the MBD2/3 gene in Bombyx mori,MBD2/3-S and MBD2/3-L.Binding analysis of MBD2/3-L,MBD2/3-S,and 7 mutant MBD2/3-L proteins deficient inβ1−β6 orα1 in the MBD showed thatβ2−β3-turns in theβ-sheet of the MBD are necessary for the formation of the MBD2/3–mCpG complex;furthermore,other secondary structures,namely,β4−β6 and anα-helix,play a role in stabilizing theβ-sheet structure to ensure that the MBD is able to bind mCpG.In addition,sequence alignment and binding analyses of different insect MBD2/3s indicated that insect MBD2/3s have an intact and conserved MBD that binds to the mCpG of target genes.Furthermore,MBD2/3 RNA interference results showed that MBD2/3-L plays a role in regulating B.mori embryonic development,similar to that of DNA methylation;however,MBD2/3-S withoutβ4−β6 andα-helix does not alter embryonic development.These results suggest that MBD2/3-L recognizes and binds to mCpG through the intactβ-sheet structure in its MBD,thus ensuring silkworm embryonic development.展开更多
目的:研究甲基化CpG结合结构蛋白2(methyl-CpG-binding domain protein 2,MBD2)在胃癌的表达及靶向抑制。方法:免疫组化法对40例胃癌及配对胃黏膜组织,免疫荧光法对胃癌细胞SGC-7901行MBD2表达研究。构建3个靶向抑制MBD2的siRNA(MBD2-si...目的:研究甲基化CpG结合结构蛋白2(methyl-CpG-binding domain protein 2,MBD2)在胃癌的表达及靶向抑制。方法:免疫组化法对40例胃癌及配对胃黏膜组织,免疫荧光法对胃癌细胞SGC-7901行MBD2表达研究。构建3个靶向抑制MBD2的siRNA(MBD2-siRNA-1、MBD2-siRNA-2、MBD2-siRNA-3)。转染MBD2-siRNA入SGC-7901,RT-PCR及Western blot验证MBD2的抑制效果。噻唑蓝比色法检测SGC-7901增殖率。结果:胃癌组织MBD2表达较对照胃黏膜组织增强(χ2=6.646,P=0.010);且低分化胃癌与伴幽门螺杆菌感染的胃癌中MBD2表达更强(χ2值分别为9.730、8.700,P值分别为0.01和0.04)。MBD2蛋白在胃癌胞核分布。MBD2-siRNA可成功转染SGC-7901,并成功筛选靶向抑制MBD2的siRNA(MBD2-siRNA-2)。发现转染MBD2-siRNA-2后96 h,SGC-7901增值率被抑制。结论:MBD2在胃癌表达增强,抑制MBD2可能抑制胃癌增殖。展开更多
基金Supported by General Program of National Natural Science Foundation of China,No.81770197Scientific and Technological Research Major Program of Chongqing Municipal Education Commission,No.KJZD-M202312802+1 种基金Chongqing Natural Science Foundation of China,No.CSTB2022NSCQ-MSX0190,No.CSTB2022NSCQ-MSX0176,and No.cstc2020jcyj-msxmX0051Xinqiao Young Postdoc Talent Incubation Program,No.2022YQB098.
文摘BACKGROUND Thrombocytopenia 2,an autosomal dominant inherited disease characterized by moderate thrombocytopenia,predisposition to myeloid malignancies and normal platelet size and function,can be caused by 5’-untranslated region(UTR)point mutations in ankyrin repeat domain containing 26(ANKRD26).Runt related transcription factor 1(RUNX1)and friend leukemia integration 1(FLI1)have been identified as negative regulators of ANKRD26.However,the positive regulators of ANKRD26 are still unknown.AIM To prove the positive regulatory effect of GATA binding protein 2(GATA2)on ANKRD26 transcription.METHODS Human induced pluripotent stem cells derived from bone marrow(hiPSC-BM)INTRODUCTION Ankyrin repeat domain containing protein 26(ANKRD26)acts as a regulator of adipogenesis and is involved in the regulation of feeding behavior[1-3].The ANKRD26 gene is located on chromosome 10 and shares regions of homology with the primate-specific gene family POTE.According to the Human Protein Atlas database,the ANKRD26 protein is localized to the Golgi apparatus and vesicles,and its expression can be detected in nearly all human tissues[4].Moreover,UniProt annotation revealed that ANKRD26 is localized in the centrosome and contains coiled-coil domains formed by spectrin helices and ankyrin repeats[5,6].The most common disease related to ANKRD26 is thrombocytopenia 2(THC2),which is a rare autosomal dominant inherited disease characterized by lifelong mild-to-moderate thrombocytopenia and mild bleeding[7-9].Caused by the variants in the 5’-untranslated region(UTR)of ANKRD26,THC2 is defined by a decrease in the number of platelets in circulating blood and results in increased bleeding and decreased clotting ability[8,10].Due to the point mutations that occur in the 5’-UTR of ANKRD26,its negative transcription factors(TFs),Runt related transcription factor 1(RUNX1)and friend leukemia integration 1(FLI1),lose their repression effect[11].The persistent expression of ANKRD26 increases the activity of the mitogen activated protein kinase and extracellular signal regulated kinase 1/2 signaling pathways,which are potentially involved in the regulation of thrombopoietin-dependent signaling and further impair proplatelet formation by megakaryocytes(MKs)[11].However,the positive regulators of ANKRD26,which might be associated with THC2 pathology,are still unknown.
基金supported by grants from Natural Science Foundation of Hubei Province(No:2012FFB02304)Scientific Research Foundation of Ministry of Education(No:2013-1792),China
文摘Summary： The role of methyl-CpG binding domain protein 2 （MBD2） in an ApoE-deficient mouse model of age-related macular degeneration （AMD） was investigated. Eight-week-old Mbd2/ApoE double deficient （Mbd2^-/- ApoE^-/-） mice （n=12, 24 eyes, experimental group） and MBD2 （wt） ApoE^-/- mice （n=12, 24 eyes, control group） were fed on Western-type diet for 4 months. The mice were sacrificed, and total serum cholesterol levels were analyzed and Bruch＇s membrane （BM） of the eyes was removed for ultrastructural observation by transmission electron microscopy. Moreover, intercellular adhesion molecule 1 （ICAM-1） immunoreactivities were evaluated by fluorescence microscopy in sections of the eyes in both groups for further understanding the function mechanism of MBD2. There was no significant difference in the total serum cholesterol levels between control group and experimental group （P〉0.05）. Transmission electron microscopy revealed that AMD-like lesions, various vacuoles accumulated on BM, notable outer collagenous layer deposits and dilated basal infoldings of retinal pigment epithelium （RPE） were seen in both groups, and the BM in control group was significantly thickened as compared with experimental group （P〈0.05）. Fluorescence micrographs exhibited the expression of ICAM-1 in choroid was higher in control group than in experimental group. We are led to conclude that MBD2 gene knockout may lead to accumulation of more deposits on the BM and influence the pathogenesis of AMD via triggering endothelial activation and inflammatory response in choroid, improving microcirculation, and reducing lipid deposition so as to inhibit the development of AMD-like lesions. Our study helps to provide a new therapeutic approach for the clinical treatment of AMD.
基金Supported by National Natural Science Foundation of China,No. 81071998Hubei Natural Science Foundation,No.2008CDB159Specialized Research Fund for the Doctoral Program of Higher Education,No. 20070487114
文摘AIM:To investigate the reciprocal modulation between microRNA(miRNA) and DNA methylation via exploring the correlation between miR-373 and methyl-CpGbinding domain protein(MBD)2.METHODS:MiR-373 expression was examined using the TaqMan miRNA assay.Methylation of miR-373 was investigated using methylation-specific polymerase chain reaction,and recruitment of methyl binding proteins was studied using the chromatin immunoprecipitation assay.Mutation analysis was conducted using the QuikChange Site-Directed Mutagenesis kit.The activity of miR-373 gene promoter constructs and targeting at MBD2-three prime untranslated region(3'UTR) by miR-373 were evaluated by a dual-luciferase reporter gene assay.RESULTS:In hilar cholangiocarcinoma,miR-373 decreased and was closely associated with poor cell differentiation,advanced clinical stage,and shorter survival.The promoter-associated CpG island of miR-373 gene was hypermethylated and inhibited expression of miR-373.MBD2 was up-regulated and enriched at the promoter-associated CpG island of miR-373.Methylation-mediated suppression of miR-373 required MBD2 enrichment at the promoter-associated CpG island,and miR-373 negatively regulated MBD2 expression through targeting the 3'UTR.CONCLUSION:MiR-373 behaves as a direct transcriptional target and negative regulator of MBD2 activity through a feedback loop of CpG island methylation.
基金Supported by the National Natural Science Foundation of China,No.81771222the Guangdong Province Basic and Applied Basic Research Fund Project,No.2019A1515011316the Guangzhou Science and Technology Plan Project,No.202007030011.
文摘Caused by the mutation of methyl-CpG binding protein 2(MeCP2),Rett syndrome leads to a battery of severe neural dysfunctions including the regression of motor coordination and motor learning.Current understanding has revealed the motor cortex as the critical region mediating voluntary movement.In this review article,we will summarize major findings from human patients and animal models regarding the cortical synaptic plasticity under the regulation of MeCP2.We will also discuss how mutation of MeCP2 leads to the disruption of cortical circuitry homeostasis to cause motor deficits.Lastly,potential values of physical exercise and neuromodulation approaches to recover neural plasticity and motor function will be evaluated.All of this evidence may help to accelerate timely diagnosis and effective interventions for Rett syndrome patients.
基金funded by the National Natural Sci-ence Foundation of China,grant numbers 32100374 and 31872286.
文摘Methyl-CpG(mCpG)binding domain(MBD)proteins especially bind with methylated DNA,and are involved in many important biological processes;however,the binding mechanism between insect MBD2/3 and mCpG remains unclear.In this study,we identified 2 isoforms of the MBD2/3 gene in Bombyx mori,MBD2/3-S and MBD2/3-L.Binding analysis of MBD2/3-L,MBD2/3-S,and 7 mutant MBD2/3-L proteins deficient inβ1−β6 orα1 in the MBD showed thatβ2−β3-turns in theβ-sheet of the MBD are necessary for the formation of the MBD2/3–mCpG complex;furthermore,other secondary structures,namely,β4−β6 and anα-helix,play a role in stabilizing theβ-sheet structure to ensure that the MBD is able to bind mCpG.In addition,sequence alignment and binding analyses of different insect MBD2/3s indicated that insect MBD2/3s have an intact and conserved MBD that binds to the mCpG of target genes.Furthermore,MBD2/3 RNA interference results showed that MBD2/3-L plays a role in regulating B.mori embryonic development,similar to that of DNA methylation;however,MBD2/3-S withoutβ4−β6 andα-helix does not alter embryonic development.These results suggest that MBD2/3-L recognizes and binds to mCpG through the intactβ-sheet structure in its MBD,thus ensuring silkworm embryonic development.
