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
X-linked methyl-CpG binding protein 2 mutations can induce symptoms similar to those of Parkinson’s disease and dopamine metabolism disorders, but the specific role of X-linked methyl-CpG binding protein 2 in the pat...X-linked methyl-CpG binding protein 2 mutations can induce symptoms similar to those of Parkinson’s disease and dopamine metabolism disorders, but the specific role of X-linked methyl-CpG binding protein 2 in the pathogenesis of Parkinson’s disease remains unknown. In the present study, we used 6-hydroxydopamine-induced human neuroblastoma cell （SH-SY5Y cells） injury as a cell model of Parkinson’s disease. The 6-hydroxydopamine （50 μmol/L） treatment decreased protein levels for both X-linked methyl-CpG binding protein 2 and tyrosine hydroxylase in these cells, and led to cell death. However, overexpression of X-linked methyl-CpG binding protein 2 was able to ameliorate the effects of 6-hydroxydopamine, it reduced 6-hydroxydopamine-induced apoptosis, and increased the levels of tyrosine hydroxylase in SH-SY5Y cells. These findings suggesting that X-linked methyl-CpG binding protein 2 may be a potential therapeutic target for the treatment of Parkinson’s disease.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
背景甲基化CpG结合蛋白2(methyl-CpG-binding protein 2,MeCP2)在基因转录调控中发挥重要作用,研究表明MeCP2可能是胶质瘤治疗的一个新靶点,但其在胶质瘤中的表达与患者预后的关系尚不清楚。目的探讨MeCP2在胶质瘤中的表达与患者手术后...背景甲基化CpG结合蛋白2(methyl-CpG-binding protein 2,MeCP2)在基因转录调控中发挥重要作用,研究表明MeCP2可能是胶质瘤治疗的一个新靶点,但其在胶质瘤中的表达与患者预后的关系尚不清楚。目的探讨MeCP2在胶质瘤中的表达与患者手术后临床预后的关系。方法选择2016年1月—2018年10月在贵阳市第二人民医院神经外科手术治疗的临床病理资料完整的96例胶质瘤患者,应用免疫组织化学方法检测肿瘤组织和正常脑组织中MeCP2的表达,随访患者生存情况。采用Kaplan-Meier法进行生存分析;采用Cox单因素和多因素风险回归模型分析MeCP2表达水平及相关临床病理因素与患者生存预后的关系。结果96例患者获得随访,其中男51例,女45例,年龄7~79岁,平均年龄(44.9±18.3)岁。免疫组化结果显示胶质瘤组织中MeCP2阳性表达率高于正常脑组织(75.0%vs 30.0%,P<0.05)。MeCP2表达的阳性率在WHOⅠ~Ⅳ级胶质瘤组织中分别为20.0%、66.7%、75.0%、90.6%(1/5、18/27、24/32、29/32),在高级别胶质瘤(WHOⅢ、Ⅳ级)中的阳性表达率高于低级别胶质瘤(WHOⅠ、Ⅱ级),差异有统计学意义(P<0.05)。70例出现肿瘤复发,59例死亡,中位无进展生存期(progression-free survival,PFS)和总生存期(overall survival,OS)分别为(10.7±1.7)个月和(24.1±2.9)个月。Kaplan-Meier生存分析显示,胶质瘤患者中MeCP2高表达组的中位PFS和OS显著低于低表达组[PFS:(15.6±1.8)个月vs(28.0±2.6)个月,P=0.026;OS:(16.1±2.0)个月vs(28.3±5.8)个月,P=0.022]。Cox回归分析显示,MeCP2高表达(HR:1.705,95%CI:1.019~2.854)、肿瘤病变多发(HR:2.727,95%CI:1.453~5.120)、单纯采用手术治疗(HR:1.704,95%CI:1.015~2.861)、高病理级别(WHOⅢ、Ⅳ级)(HR:3.294,95%CI:2.317~4.683)是胶质瘤患者预后不良的独立危险因素。结论MeCP2在胶质瘤手术患者中表达水平上调,且高表达水平与胶质瘤患者术后不良预后相关。展开更多
Objective: To observe the effect of puerarin on methyl-CpG binding protein 2(MeCP2) phosphorylation(pMeCP2) in the hippocampus of a rat model of vascular dementia(VD). Methods: Thirty-six healthy Sprague-Dawley rats w...Objective: To observe the effect of puerarin on methyl-CpG binding protein 2(MeCP2) phosphorylation(pMeCP2) in the hippocampus of a rat model of vascular dementia(VD). Methods: Thirty-six healthy Sprague-Dawley rats were randomly assigned to the sham-operated group, dementia group and puerarintreated group using a random number table(n=12 per group). The modified permanent bilateral common carotid artery occlusion method was used to establish the VD model. The sham-operated and dementia groups were given 2 m L/d of saline, while the puerarin-treated group was given 100 mg/(kg·d) of puerarin for 17 days. The learning and memory abilities were evaluated by the Morris water maze test. Hematoxylin-eosin staining, immunohistochemical(IHC) staining and Western blot analysis were carried out to observe changes in neuron morphology and in level of pMeCP2 in the hippocampus, respectively. Results: The morphologies of rat hippocampal neurons in the puerarintreated group were markedly improved compared with the dementia group. The escape latency of the dementia group was significantly longer than the sham-operated group(P<0.05), while the puerarin-treated group was obviously shorter than the dementia group(P<0.05). Cross-platform times of the dementia group were significantly decreased compared with the sham-operated group(P<0.05), while the puerarin-treated group was obviously increased compared with the dementia group(P<0.05). IHC staining showed no significant difference in the number of MeCP2 positive cells among 3 groups(P>0.05). The number of pMeCP2 positive cells in the CA1 region of hippocampus in the dementia group was significantly increased compared with the sham-operated group, and the puerarin-treated group was significantly increased compared with the dementia group(both P<0.05). Western blot analysis showed no significant difference of MeCP2 expression among 3 groups(P>0.05). The expression of pMeCP2 in the dementia group was significantly increased compared with the sham-operated group, while it in the puerarin-treated group was significantly increased compared with the dementia group(P<0.05). Conclusion: Puerarin could play a role in the protection of nerve cells through up-regulating pMeCP2 in the hippocampus, improving neuron morphologies, and enhancing learning and memory ablities in a rat model of VD.展开更多
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sponsored by the Ph.D.Independent Research Projects of Wuhan University,No.201130302020017a grant from the Science and Technology Bureau of Hubei Province,No.2011CDB511the National Natural Science Foundation of China,No.81170769
文摘X-linked methyl-CpG binding protein 2 mutations can induce symptoms similar to those of Parkinson’s disease and dopamine metabolism disorders, but the specific role of X-linked methyl-CpG binding protein 2 in the pathogenesis of Parkinson’s disease remains unknown. In the present study, we used 6-hydroxydopamine-induced human neuroblastoma cell （SH-SY5Y cells） injury as a cell model of Parkinson’s disease. The 6-hydroxydopamine （50 μmol/L） treatment decreased protein levels for both X-linked methyl-CpG binding protein 2 and tyrosine hydroxylase in these cells, and led to cell death. However, overexpression of X-linked methyl-CpG binding protein 2 was able to ameliorate the effects of 6-hydroxydopamine, it reduced 6-hydroxydopamine-induced apoptosis, and increased the levels of tyrosine hydroxylase in SH-SY5Y cells. These findings suggesting that X-linked methyl-CpG binding protein 2 may be a potential therapeutic target for the treatment of Parkinson’s disease.
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.
基金Supported by the National Natural Science Foundation of China(No.81270415/H2501)
文摘Objective: To observe the effect of puerarin on methyl-CpG binding protein 2(MeCP2) phosphorylation(pMeCP2) in the hippocampus of a rat model of vascular dementia(VD). Methods: Thirty-six healthy Sprague-Dawley rats were randomly assigned to the sham-operated group, dementia group and puerarintreated group using a random number table(n=12 per group). The modified permanent bilateral common carotid artery occlusion method was used to establish the VD model. The sham-operated and dementia groups were given 2 m L/d of saline, while the puerarin-treated group was given 100 mg/(kg·d) of puerarin for 17 days. The learning and memory abilities were evaluated by the Morris water maze test. Hematoxylin-eosin staining, immunohistochemical(IHC) staining and Western blot analysis were carried out to observe changes in neuron morphology and in level of pMeCP2 in the hippocampus, respectively. Results: The morphologies of rat hippocampal neurons in the puerarintreated group were markedly improved compared with the dementia group. The escape latency of the dementia group was significantly longer than the sham-operated group(P<0.05), while the puerarin-treated group was obviously shorter than the dementia group(P<0.05). Cross-platform times of the dementia group were significantly decreased compared with the sham-operated group(P<0.05), while the puerarin-treated group was obviously increased compared with the dementia group(P<0.05). IHC staining showed no significant difference in the number of MeCP2 positive cells among 3 groups(P>0.05). The number of pMeCP2 positive cells in the CA1 region of hippocampus in the dementia group was significantly increased compared with the sham-operated group, and the puerarin-treated group was significantly increased compared with the dementia group(both P<0.05). Western blot analysis showed no significant difference of MeCP2 expression among 3 groups(P>0.05). The expression of pMeCP2 in the dementia group was significantly increased compared with the sham-operated group, while it in the puerarin-treated group was significantly increased compared with the dementia group(P<0.05). Conclusion: Puerarin could play a role in the protection of nerve cells through up-regulating pMeCP2 in the hippocampus, improving neuron morphologies, and enhancing learning and memory ablities in a rat model of VD.
