Biomedical Research ; Child ; Humans ; Methyl-CpG-Binding Protein 2 ; metabolism ; Rett Syndrome

Methyl-CpG-binding protein 2 gene (MECP2; OMIM 300005) is located at chromosome Xq28. Mutations of the gene including point mutation, duplication and deletion can lead to severe neurodevelopmental disorders. The disease caused by duplication of the entire MECP2 gene, named as MECP2 duplication syndrome, is mostly seen in males. The clinical manifestation of this syndrome include mental retardation, hypotonia, poor speech development, recurrent infection, progressive spasticity, epilepsy, autism or autistic features with or without midface hypoplasia. Most patients have inherited the duplication from their unaffected mothers, with only a few cases having de novo mutation. Females with duplicated MECP2 gene are typically asymptomatic because of a skewed X chromosome inactivation (XCI) pattern. Proposed mechanisms of this genomic rearrangement include fork stalling and template switching (FoSTeS) and microhomology mediated break-induced replication (MMBIR). Since no effective treatment is available for this disease, proper genetic counseling and prenatal diagnosis for the high risk families are crucial.
Animals ; Female ; Gene Duplication ; Humans ; Male ; Mental Retardation, X-Linked ; genetics ; metabolism ; Methyl-CpG-Binding Protein 2 ; genetics ; metabolism

Mutations of the X-linked methyl-CpG-binding protein 2 (MECP2) gene in humans are responsible for most cases of Rett syndrome (RTT), an X-linked progressive neurological disorder. While genome-wide screens in clinical trials have revealed several putative RTT-associated mutations in MECP2, their causal relevance regarding the functional regulation of MeCP2 at the etiologic sites at the protein level requires more evidence. In this study, we demonstrated that MeCP2 was dynamically modified by O-linked-β-N-acetylglucosamine (O-GlcNAc) at threonine 203 (T203), an etiologic site in RTT patients. Disruption of the O-GlcNAcylation of MeCP2 specifically at T203 impaired dendrite development and spine maturation in cultured hippocampal neurons, and disrupted neuronal migration, dendritic spine morphogenesis, and caused dysfunction of synaptic transmission in the developing and juvenile mouse cerebral cortex. Mechanistically, genetic disruption of O-GlcNAcylation at T203 on MeCP2 decreased the neuronal activity-induced induction of Bdnf transcription. Our study highlights the critical role of MeCP2 T203 O-GlcNAcylation in neural development and synaptic transmission potentially via brain-derived neurotrophic factor.
Animals ; Humans ; Methyl-CpG-Binding Protein 2/metabolism* ; Mice ; Neurodevelopmental Disorders/genetics* ; Rett Syndrome/genetics* ; Synaptic Transmission ; Threonine

OBJECTIVETo investigate the effects of methylation status of CpG islands of endogenous E-cadherin (CDH1) gene on the promoter activity of corresponding genes in reporter assays.

METHODSThe methylation statuses of CpG island of CDH1 in 8 different cell lines were detected by methylation-specific PCR. CDH1 protein was analyzed by Western blotting. Two sets of pGL3 reporter vectors with different genotypes/haplotypes of the CDH1 promoter were constructed [ pGL3-A(-73)/-C(-73) pGL3-H1/-H4] and used to transfect these cell lines. The differences between these promoter reporter vectors were analyzed by t-test.

RESULTS(1) CDH1 CpG island was unmethylated in AGS, MCF7, MKN74, and PC-3 cell lines, expressed in MCF7, MKN74, and PC-3, but not in AGS. Expression of CDH1 was silenced by methylation in HeLa, BGC823, A549, and RKO cell lines. (2) In the four CDH1-unmethylated MCF7, MKN74, PC-3, and AGS cell lines, the promoter activities of pGL3-C(-73), (as 0.78 +/- 0.10, 0.17 +/- 0.01, 0.11 +/- 0.01, 1.19 +/- 0.18) were significantly higher than those of pGL3-A(-73) (as 0.30 +/- 0.08, 0.07 +/- 0.01, 0.07 +/- 0.01, 0.39 +/- 0.04) (t values are -6.298, - 12.349, -8.128, -7.388, and P <. 0.1). However, in the four CDH1-methylated HeLa, BGC823, A549, and RKO cell lines, the promoter activity of pGL3-C(-73) (as 0.09 +/- 0.02, 0.13 +/- 0.02, 0.05 +/- 0.01, 0.01 +/- 0.00) was significantly lower than that of pGL3-A(-73) (as 0.16 +/- 0.01, 0.25 +/- 0.01, 0.11 +/- 0.03, 0.03 +/- 0.00) (t valued at 5.958, 11.189, 3.661, 13.866, and P<0.05). (3) In the unmethylated MKN74 and methylated RKO cell lines, the promoter activities of pGL3-H1/-H4 were obviously and contrarily different (as 1.57 +/- 0.23/0.94 +/- 0.06 and 0.38 +/- 0.02/0.50 +/- 0.04, t values were 4.577 and -4.915, P values were 0.010 and 0.003).

CONCLUSIONThe methylation status of CpG island of the target gene in the tested cell lines affects the promoter activity in Reporter Assay significantly. The most active one may be the most suppressive one.

Cadherins ; genetics ; metabolism ; Cell Line, Tumor ; CpG Islands ; genetics ; DNA Methylation ; Flow Cytometry ; Genes, Reporter ; Humans ; Luciferases ; genetics ; Methyl-CpG-Binding Protein 2 ; genetics ; Promoter Regions, Genetic

MicroRNAs (miRNAs) are critical for both development and function of the central nervous system. Significant evidence suggests that abnormal expression of miRNAs is associated with neurodevelopmental disorders. MeCP2 protein is an epigenetic regulator repressing or activating gene transcription by binding to methylated DNA. Both loss-of-function and gain-of-function mutations in the MECP2 gene lead to neurodevelopmental disorders such as Rett syndrome, autism and MECP2 duplication syndrome. In this study, we demonstrate that miR-130a inhibits neurite outgrowth and reduces dendritic spine density as well as dendritic complexity. Bioinformatics analyses, cell cultures and biochemical experiments indicate that miR-130a targets MECP2 and down-regulates MeCP2 protein expression. Furthermore, expression of the wild-type MeCP2, but not a loss-of-function mutant, rescues the miR-130a-induced phenotype. Our study uncovers the MECP2 gene as a previous unknown target for miR-130a, supporting that miR-130a may play a role in neurodevelopment by regulating MeCP2. Together with data from other groups, our work suggests that a feedback regulatory mechanism involving both miR-130a and MeCP2 may serve to ensure their appropriate expression and function in neural development.
Animals ; Dendrites ; genetics ; metabolism ; Dendritic Spines ; genetics ; metabolism ; Down-Regulation ; physiology ; Methyl-CpG-Binding Protein 2 ; biosynthesis ; genetics ; MicroRNAs ; genetics ; metabolism ; Rats

OBJECTIVETo explore the effect of DNA methyltransferase 1 (DNMT1) and methyl-CpG-binding protein 2 (MeCP2) on cervical cancer and cervix precancerous lesion.

METHODS74 patients with cervix squamous cell carcinoma(SCC), 52 patients with cervical intraepithelial neoplasm I (CIN I), 60 patients with cervical intraepithelial neoplasm II - II (CIN II-III)and 58 patients with histologically diagnosed cervix inflammation(CI), were included in this study. Information as demography, reproductive history, life style, HPV infection were collected. Western Blot were used to detect the expression of DNMT1 protein and MeCP2 protein. Real-time PCR was used to detect the expression of DNMT1 and MeCP2 mRNA.

RESULTSLevels of DNMT1 and MeCP2 protein expression increased gradually with the deterioration of cervical lesion (H = 94.33, P < 0.001;F = 21.580, P < 0.001). Along with the deterioration of cervical lesion, levels of DNMT1 and MeCP2 mRNA expression were gradually increasing( F = 4.758, P = 0.003; F = 7.804, P < 0.001). Data from Correlation analysis showed that both protein (r = 0.287, P < 0.001) and mRNA(r = 0.179, P = 0.005)were positive correlated with DNMT1 and MeCP2.

RESULTSof our study indicated that there was an additive interaction between high-expression of DNMT1 protein and high-expression of MeCP2 protein in SCC or CIN II-III. However, there was an additive interaction between high-expression of DNMT1 mRNA and high-expression of MeCP2 mRNA in SCC or CIN II-III.

CONCLUSIONResults from our study revealed the fact that both high expression of DNMT1 protein and high expression of MeCP2 protein could increase the risk of cervix cancerization. According to our findings, there might be a synergistic action existed between DNMT1 and MeCP2 during the progression of cervix cancelation.

Adult ; Aged ; Carcinoma, Squamous Cell ; metabolism ; pathology ; Cervical Intraepithelial Neoplasia ; metabolism ; pathology ; Female ; Humans ; Methyl-CpG-Binding Protein 2 ; metabolism ; Middle Aged ; O(6)-Methylguanine-DNA Methyltransferase ; metabolism ; RNA, Messenger ; genetics ; Uterine Cervical Neoplasms ; metabolism ; pathology

Objective: To explore the relationship between abnormal expression of fragile histidine triad (FHIT) gene and methyl-CpG-binding protein 2 (MeCP2) as well as their interaction on cervical cancerization. Methods: A total of 73 patients with cervical squamous cell carcinoma (SCC), 113 patients with cervical intraepithelial neoplasia (CIN Ⅰ, n=45; CINⅡ/Ⅲ, n=68) and 60 women with normal cervix (NC) were included in the study. Real time PCR and Western blot were performed to detect the expression levels of mRNA and protein about FHIT and MeCP2, respectively. The methylation status of FHIT gene CpG island was tested by methylation-specifc PCR (MSP). Kruskal-Wallis H test, χ(2) test, trend χ(2) test and Spearman correlation analysis were conducted with software SPSS 20.0. The interaction was evaluated by generalized multifactor dimensionality reduction (GMDR) model. Results: With the deterioration of cervical lesion, the methylation rates of FHIT gene CpG island (χ(2)=18.64, P<0.001; trend χ(2)=18.08, P<0.001) increased gradually, while the expression levels of FHIT mRNA (H=27.32, P<0.001; trend χ(2)=12.65, P<0.001) and protein (H=47.10, P<0.001; trend χ(2)=29.79, P<0.001) decreased gradually. There was a negative correlation between the methylation rates of FHIT gene CpG island and the expression level of FHIT protein (r=-0.226, P<0.001). The levels of MeCP2 mRNA (H=26.19, P<0.001; trend χ(2)=11.81, P=0.001) and protein (H=69.02, P<0.001; trend χ(2)=47.44, P<0.001) increased gradually with the aggravation of cervical lesions. There was a positive correlation between the expression level of MeCP2 protein and the FHIT mRNA Ct ratio (r=0.254, P<0.001). Expression of proteins were negatively correlated between MeCP2 and FHIT (r=-0.213, P=0.001). The results analyzed by GMDR model showed that there were interactions among high MeCP2 protein expression, the CpG island methylation of FHIT and mRNA and protein expression in CINⅡ/Ⅲ group, and among high MeCP2 mRNA and protein expression, the CpG island methylation of FHIT and low mRNA and protein expression in SCC group. Conclusion: High expression of MeCP2 mRNA and protein, the CpG island methylation and low mRNA and protein expression of FHIT could increase the risk of cervical carcinogenesis, and there might be a synergistic effect on cervical carcinogenesis.
Acid Anhydride Hydrolases/metabolism* ; Carcinoma, Squamous Cell/pathology* ; DNA Methylation ; Female ; Gene Expression Regulation, Neoplastic ; Humans ; Methyl-CpG-Binding Protein 2/metabolism* ; Neoplasm Proteins/metabolism* ; Polymerase Chain Reaction/methods* ; RNA, Messenger ; Uterine Cervical Neoplasms/pathology* ; Uterine Cervical Dysplasia/pathology*

OBJECTIVETo 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).

METHODSThirty-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 modifified permanent bilateral common carotid artery occlusion method was used to establish the VD model. The sham-operated and dementia groups were given 2 mL/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.

RESULTSThe 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 signifificantly 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 signifificantly increased compared with the sham-operated group, and the puerarin-treated group was signifificantly increased compared with the dementia group (both P<0.05). Western blot analysis showed no signifificant difference of MeCP2 expression among 3 groups (P>0.05). The expression of pMeCP2 in the dementia group was signifificantly increased compared with the sham-operated group, while it in the puerarin-treated group was signifificantly increased compared with the dementia group (P<0.05).

CONCLUSIONPuerarin 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.

Animals ; Dementia, Vascular ; drug therapy ; genetics ; physiopathology ; Hippocampus ; pathology ; Isoflavones ; chemistry ; pharmacology ; therapeutic use ; Memory ; drug effects ; Methyl-CpG-Binding Protein 2 ; metabolism ; Phosphorylation ; drug effects ; Rats, Sprague-Dawley ; Up-Regulation ; drug effects

The role of pulchinenoside (PULC) in the regulation of MeCP2 expression was investigated in RA model rats. Adjuvant arthritis rats were used as RA model rats, and fibroblast-like synoviocytes (FLS) from the RA model rats were cultured. The effect of 100 mg x kg(-1) PULC gavage treatment on the MeCP2 expression and the effect of MeCP2 siRNA on the expression of SFRP2 and β-catenin were detected by real time qPCR and Western blotting. The role of PULC in the FLS proliferation was detected by MTT. The results showed that the MeCP2 expression was down-regulated, the SFRP2 expression was up-regulated and the FLS proliferation was inhibited in FLS after therapy. MeCP2 siRNA significantly inhibited the MeCP2 expression, up-regulated the SFRP2 expression and inhibited the β-catenin expression in FLS from RA model rats. PULC may increase the SFRP2 expression, inhibit the Wnt signaling and inhibit the FLS proliferation in FLS from the RA model rats by inhibiting the MeCP2 expression.
Animals ; Arthritis, Rheumatoid ; drug therapy ; genetics ; metabolism ; Disease Models, Animal ; Drugs, Chinese Herbal ; administration & dosage ; Fibroblasts ; drug effects ; metabolism ; Gene Expression Regulation ; drug effects ; Humans ; Male ; Methyl-CpG-Binding Protein 2 ; genetics ; metabolism ; Rats ; Rats, Sprague-Dawley ; Synovial Membrane ; cytology ; drug effects ; metabolism ; Wnt Signaling Pathway ; drug effects ; beta Catenin ; genetics ; metabolism