Genetic analysis of a case with MEF2C deletion in association with 5q14.3 microdeletion syndrome / 中华医学遗传学杂志

OBJECTIVE@#To explore the genetic basis for a child with febrile seizures.@*METHODS@#Peripheral venous blood samples were taken from the child and his parents for the analysis of chromosomal karyotype and dynamic variant of the FMR1 gene. The family trio was also subjected to target capture and next generation sequencing (NGS) with a gene panel related to developmental retardation, mental retardation, language retardation, epilepsy and special facial features.@*RESULTS@#The child was found to have a normal karyotype by conventional cytogenetic analysis (400 bands). No abnormal expansion was found with the CGG repeats of the FMR1 gene. NGS revealed that the child has carried a heterozygous c.864+1 delG variant of the MEF2C gene, which may lead to abnormal splicing and affect its protein function. The same variant was found in neither parent, suggesting that it has a de novo origin. Based on the American College of Medical Genetics and Genomics standards and guidelines, c.864+1delG variant of MEF2C gene was predicted to be pathogenic (PVS1+PS2+PM2).@*CONCLUSION@#MEF2C, as the key gene for chromosome 5q14.3 deletion syndrome which was speculated as a cause for febrile seizures, has an autosomal dominant effect. The c.864+1delG variant of the MEF2C gene may account for the febrile seizures in this patient.

Effect of Xiaozhong Zhitong Ointment on MEF2 mRNA and protein expression in rats with gastrointestinal muscle injury / 中国骨伤

OBJECTIVE@#To investigate the effect of Xiaozhong Zhitong Ointment(XZZTO) on remodeling and repair of skeletal muscle injury in rats based on the expression mechanism of microRNA.@*METHODS@#The rat gastrocnemius injury model was established by blunt contusion model. The expression of MEF2 gene and protein in gastrocnemius muscle was detected by quantitative PCR at 4, 7, 14 and 21 days after injury with XZZTO. The mechanism of the effect of XZZTO on the muscle remodeling and repair of rat gastrocnemius contusion model was discussed.@*RESULTS@#The expression level of MEF2 in the treatment group was significantly higher than that of the control group and model group, which further confirmed the important role of MEF2 in inducing skeletal muscle remodeling and repair process in the topical drugs. The expression of MEF2 increased at 7 days after injury and remained at a high level until 21 days after injury. Compared with the model group, the peak expression period was about 14 days, and then returned to the general state.@*CONCLUSIONS@#The expression level of MEF2 shows an upward trend. Even 21 days after injury, the expression of MEF2 dose not show a significant downward trend. It can be seen that XZZTO can promote the expression of MEF2. At the same time, XZZTO can regulate the regeneration and repair of skeletal muscle. Therefore, XZZTO can play a regeneration and repair role after skeletal muscle injury through gene regulation.

Polimorfismos de los genes JAG1, MEF2C y BDNF asociados con la densidad mineral ósea en mujeres del norte de México / JAG1, MEF2C and BDNF polymorphisms associated with bone mineral density in women from Northern México

Resumen Introducción. La osteoporosis se caracteriza por una baja densidad mineral ósea; la composición genética es uno de los factores que más influyen en ella, pero hay pocos estudios de genes asociados con esta condición en la población mexicana. Objetivo. Investigar la posible asociación de ocho polimorfismos de un solo nucleótido (Single Nucleotide Polymorphism, SNP) de los genes JAG1, MEF2C y BDNF con la densidad mineral ósea en mujeres del norte de México. Materiales y métodos. Participaron 124 mujeres de 40 a 80 años, sin parentesco entre ellas. Su densidad mineral ósea se determinó mediante absorciometría dual de rayos X y la genotipificación se hizo utilizando discriminación alélica mediante PCR en tiempo real; se estudiaron cuatro de los SNP del gen JAG1 (rs6514116, rs2273061, rs2235811 y rs6040061), tres del MEF2C (rs1366594, rs12521522 y rs11951031) y uno del BDNF (rs6265). El análisis estadístico de los datos obtenidos se hizo por regresión lineal. Resultados. El SNP rs2235811 presentó asociación significativa con la densidad mineral ósea de todo el cuerpo bajo el modelo de herencia dominante (p=0,024) y, aunque los otros SNP no tuvieron relación significativa con esta densidad, en ninguno de los modelos de herencia estudiados, se observó una tendencia hacia esta asociación. Conclusión. Los resultados sugieren que el SNP rs2235811 del gen JAG1 podría contribuir a la variación en la densidad mineral ósea de las mujeres del norte de México.

Abstract Introduction: Osteoporosis is characterized by a low bone mineral density. Genetic composition is one of the most influential factors in determining bone mineral density (BMD). There are few studies on genes associated with BMD in the Mexican population. Objective: To investigate the association of eight single nucleotide polymorphisms (SNP) of JAG1, MEF2C and BDNF genes with BMD in women of Northern México. Materials and methods: This study involved 124 unrelated Mexican women between 40 and 80 years old. BMD was determined by dual X-ray absorptiometry. Genotyping was performed using allelic discrimination by real time PCR. We analyzed the SNP of JAG1 (rs6514116, rs2273061, rs2235811 and rs6040061), MEF2C (rs1366594, rs12521522 and rs11951031), and BDNF (rs6265) and the data using linear regression. Results: The JAG1 SNP rs2235811 was associated with the BMD of the total body under the dominant inheritance model (p=0,024). Although the other SNPs were not associated with BMD in any of the inheritance models studied, a trend was observed. Conclusion: Our results suggest that the SNP rs2235811 in the JAG1 gene might contribute to the variation in BMD in women from northern México.

Expression of Myocardial Specificity Markers MEF-2C and Cx43 in Rat Bone Marrow-derived Mesenchymal Stem Cells Induced by Electrical Stimulation In Vitro / 生物医学工程学杂志

Bone marrow-derived mesenchymal stem cells (BMSCs) for repairing damaged heart tissue are a new kind of important treatment options because of their potential to differentiate into cardiomyocytes. We in this experiment investigated the effect of different electrical stimulation time on the expression of myocardial specificity gene and protein in rat bone marrow mesenchymal stem cells (rBMSCs) in vitro. The rBMSCs of second or third generation were randomly divided into three groups, i.e, electrical stimulation (ES) group, 5-Azacytidine (5-Aza) group and the control group. The rBMSCs in the ES groups with complete medium were exposed to 2 V, 2 Hz, 5 ms electrical stimulation for 0. 5 h, 2 h, 4 h, and 6 h respectively every day for 10 days. Those in the 5-Aza group were induced by 5-Aza (10 μmol/L) for 24 h, and then cultured with complete medium for 10 days. Those in the control group were only cultured with complete medium, without any treatment, for 10 days. The rBMSCs' morphological feature in each group was observed with inverted phase microscope. The mRNA expression of myocyte-specific enhancer factor 2C (MEF-2C) and connexin 43 (Cx43) were examined with Real-Time quantitative PCR and the protein expression of MEF-2C, Cx43 were detected with Western Blot method. The results showed that the mRNA expression level of the MEF-2C, Cx43 and the protein expression level of MEF-2C, Cx43 were significantly higher in the ES group and 5-Aza group than those in the relative control group (P < 0.05). It suggests that electrical stimulation could play a part of role in the induction of the rBMSCs to differentiate into the cariomyocyte-like cells in vitro and the effectiveness of the electrical stimulation with 2 h/d had the best in our experiment. But the mechanism how electrical stimulation promotes the differentiation of rBMSC into cardiomyocyte is still unclear.

Myocyte Enhancer Factor-2A Gene Mutation and Coronary Artery Disease / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Premature ventricular contractions (PVCs) are common in the general population, and frequent PVCs may result in the poor quality of life or even the damage of cardiac function. We examined the efficacy and safety of a traditional Chinese medicine Wenxin Keli for the treatment of frequent PVCs among a relatively large Chinese cohort.</p><p><b>METHODS</b>We performed a randomized, double-blind, placebo-controlled, parallel-group, multicenter trial. A total of 1200 eligible participants were randomly assigned in a ratio of 1:1 to receive Wenxin Keli or the placebo for 4 weeks. The primary and secondary endpoint was the change of PVC numbers and PVC-related symptoms after a 4-week treatment compared with baseline, respectively. In addition, vital signs, laboratory values, and electrocardiographic parameters were assessed in a safety analysis.</p><p><b>RESULTS</b>At the initial evaluation, no significant differences in the baseline characteristics were observed between the Wenxin Keli group and the placebo group. A smaller number of PVCs was observed after the 4-week treatment than at baseline, in both the Wenxin Keli group (5686 ± 5940 vs. 15,138 ± 7597 beats/d, P < 0.001) and the placebo group (10,592 ± 8009 vs. 14,529 ± 5929 beats/d, P < 0.001); moreover, the Wenxin Keli group demonstrated a significantly greater reduction in the frequency of PVCs than the placebo group (P < 0.001). In a full analysis set, patients in the Wenxin Keli group exhibited significantly higher total effective responses in the reduction of PVCs compared to those in the placebo group (83.8% vs. 43.5%,P < 0.001). The per-protocol analysis yielded similar results (83.0% vs. 39.3%,P < 0.001). Treatment with Wenxin Keli also demonstrated superior performance compared to the placebo with respect to PVC-related symptoms. No severe adverse effects attributable to Wenxin Keli were reported.</p><p><b>CONCLUSIONS</b>Wenxin Keli treatment effectively reduced the overall number of PVCs and alleviated PVC-related symptoms in patients without structural heart diseases and had no severe side effects.</p>

Temporal regulation of transcription factor Mef2c by histone acetylases during cardiogenesis / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To observe the temporal modification of transcription factor Mef2c by histone acetylases (HATs) P300, PCAF, and SRC1 during cardiogenesis and to provide a basis for investigating the pathogenesis of congenital heart disease.</p><p><b>METHODS</b>The normal heart tissues from embryonic mice (embryonic days 14.5 and 16.5) and neonatal mice (postnatal days 0.5 and 7) were collected. The binding of P300, PCAF, and SRC1 to Mef2c gene and level of histone H3 acetylation in the promoter region of Mef2c were evaluated by chromatin immunoprecipitation assays. Meanwhile, real-time PCR was used to measure the mRNA expression of Mef2c.</p><p><b>RESULTS</b>P300, PCAF, SRC1 were involved in histone acetylation in the promoter region of Mef2c during cardiogenesis in mice, and binding of P300, PCAF, and SRC1 to the promoter of Mef2c varied significantly in different stages of cardiogenesis (P<0.01). The level of histone H3 acetylation and mRNA expression of Mef2c in the promoter region of Mef2c also varied significantly in different stages of cardiac development (P<0.01). The levels of acetylated H3, Mef2c mRNA, and HATs (P300, PCAF, SRC1) changed over time. They were highest on embryonic day 14.5 (P<0.01), decreased gradually with cardiac development, and were maintained at low levels after birth.</p><p><b>CONCLUSIONS</b>The mRNA expression of Mef2c varies during cardiogenesis in mice, which indicates that Mef2c plays an important role in the process of cardiac development. Meanwhile, histone acetylation in the promoter region of Mef2c is regulated temporally by HATs P300, PCAF, and SRC1.</p>

Regulation of myostatin promoter activity by myocyte enhancer factor 2 / 生物工程学报

Myostatin (Mstn) is a member of the transforming growth factor-beta superfamily that functions as a negative regulator of skeletal muscle growth and differentiation in mammals. The transcriptional regulation of Mstn is controlled by multiple genes including MEF2, which raise the importance of identifying the binding sites of MEF2 on myostatin promoter region and mechanisms underlying. In this study, we investigated the transcriptional regulation of MEF2 on porcine Mstn promoter activity in C2C12 cells. Sequence analysis of the 1 969 bp porcine Mstn promoter region revealed that it contained three potential MEF2 motifs. Using a serial deletion strategy, we tested the activity of several promoter fragments by luciferase assay. Overexpression of MEF2C, but not MEF2A increased Mstn promoter activity in all the promoter fragments with MEF2 motifs by two to six folds, in both C2C12 myoblasts and myotubes. When we transfected exogenous MEF2C, Mstn mRNA level was also upregulated in C2C12 cells, but the protein level was only significantly increased in myotubes. Thus, we propose that MEF2C could modulate and restrain myogenesis by Mstn activation and Mstn-dependent gene processing in porcine. Our research also provided potential targets and an effective molecule to regulate Mstn expression and gave a new way to explore the functional performance of Mstn.

Expression of MEF2D on nasopharyngeal carcinoma tissues and its influence of prognostic / 临床耳鼻咽喉头颈外科杂志

OBJECTIVE@#To explore the expression of MEF2D in NPC tissues, study the relationship between the expression and prognostic.@*METHOD@#Specimens from 101 NPC patients who were follow-up visited 1 to 7 years were analyzed for MEF2D by using immunohistochemistry.@*RESULT@#(1) The expression of MEF2D was higher in the higher clinical stage. (2) Density and Grey of MEF2D was negative correlated (|r| = 0.865, P < 0.01). (3) NPC patients' survival rate after therapies was 52.5%, the survival curve of 1th clinical stage was higher than 4th. (4) The survival curves of MEF2D stages were no statistical significance.@*CONCLUSION@#There's statistical significance of the MEF2D expression in clinical stages, but not in survival curve, which indicated that MEF2D concerned with invasion and metastatic of NPC.

Study of the 482G/A variation in PGC-1alpha gene domain MEF2C as possible mechanism of type 2 diabetes / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To investigate the association of the 482G/A polymorphism of the PGC-1alpha gene with type 2 diabetes by family-based study in the Han population in South China, and to analyze the quantitative and qualitative binding force changes between the PGC-1alpha domain mutant and MEF2C, as well as to evaluate the possibility of PGC-1alpha -MEF2C-GLUT4 pathway in the pathogenesis of type 2 diabetes.</p><p><b>METHODS</b>Blood samples were collected from 350 patients with type 2 diabetes and their first-degree relatives. Genomic DNA was extracted and polymorphic PGC-1alpha genotypes were determined by polymerase chain reaction-restriction fragment length polymorphism and direct DNA sequencing. The results were analyzed by family-based transmission disequilibrium test (TDT) and haplotype relative risk (HRR). The protein-protein interaction between PGC-1alpha and MEF2C was detected by means of the site-directed mutagenesis kit and bacteriomatch two-hybrid system kit.</p><p><b>RESULTS</b>In the family-based study, HRR analyses demonstrated that the 482A allele was more often transmitted to patients than predicted by chance (chi (2)= 7.2170, P= 0.0072, HRR= 1.4496). TDT-extended test(ETDT) analyses also revealed that PGC-1alpha 482A allele was significantly deviated from 0.5 from heterozygous parents to patients than expected (219 trios, P= 0.0310; 350 trios, P= 0.0292). BacterioMatch Two-Hybrid System showed that 482A variation could lead to decreased binding force between PGC-1alpha and MEF2C (62.1+/- 8.97, P< 0.05).</p><p><b>CONCLUSION</b>The 482A polymorphism increases the risk of developing type 2 diabetic mellitus in the South China Han population, which might be mediated by the PGC-1alpha -MEF2C-GLUT4 pathway.</p>

The cSNPs analysis in whole extron-wide of PGC-1alpha gene in Chinese population and the domain MEF2C bioinformatics study / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To analyze distribution characteristics of PGC-1alpha gene coding single nucleotide polymorphisms (cSNPs), and to investigate the association between cSNPs and type 2 diabetes mellitus, and to study biological information about PGC-1alpha domain muscle enhancer factor 2C (MEF2C) in Chinese Han population.</p><p><b>METHODS</b>These cSNPs were identified by means of polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP), polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and DNA direct sequencing technology in a total of 263 type 2 diabetic patients and 282 normal glucose tolerant controls. The possible association was analyzed between type 2 diabetes mellitus and the specific cSNPs and their haplotypes by case-control method. The tertiary structure of PGC-1alpha domain MEF2C was predicated and analyzed for possible biological information by a series of bioinformatics soft wares.</p><p><b>RESULTS</b>Four variants were found in whole extron-wide of PGC-1alpha gene in Chinese Han diabetic population. They were 394G/A, 482G/A, 528A/G and 612C/T. The 482G/A polymorphism was remarkably associated with type 2 diabetes (chi2 = 14.2025, P= 0.0002). Haplotypes analysis shown that distribution frequency of haplotypes had a statistical difference between type 2 diabetes mellitus and normal glucose tolerance control groups (chi2 = 59.9, P< 0.01) and haplotype 394A-482A-528A had a linkage disequilibrium with type 2 diabetes (t= 2.361, P< 0.05). The tertiary simulant structure of PGC-1alpha domain MEF2C was established successfully by computer. The 482G/A variant accompanied with hydrogen bonds breaking might decrease hydrophobicity and lead to an incompact space configuration which was very critical to function.</p><p><b>CONCLUSION</b>The 482G/A variant could decrease binding force between PGC-1alpha and MEF2C and increase the risk of type 2 diabetes in Chinese Han population by PGC-1alpha -MEF2C-GLUT-4 pathway.</p>

Association between peroxisome proliferator-activated receptor-gamma coactivator-1alpha gene polymorphisms and type 2 diabetes in southern Chinese population: role of altered interaction with myocyte enhancer factor 2C / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Some single nucleotide polymorphisms (SNPs) in the peroxisome proliferator-activated receptor-gamma coactivator (PGC)-1alpha gene have been reported to be associated with type 2 diabetes in different populations, and studies on Chinese patients yielded controversial results. The objective of this case-control study was to explore the relationship between SNPs of PGC-1alpha and type 2 diabetes in the southern Chinese population and to determine whether the common variants: Gly482Ser and Thr394Thr, in the PGC-1alpha gene have any impacts on interaction with myocyte enhancer factor (MEF) 2C.</p><p><b>METHODS</b>The SNPs in all exons of the PGC-1alpha gene was investigated in 50 type 2 diabetic patients using polymerase chain reaction-single strand conformational polymorphism (PCR-SSCP) and direct sequencing. Thereafter, 263 type 2 diabetic patients and 282 healthy controls were genotyped by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). A bacterial two-hybrid system and site-directed mutagenesis were used to investigate whether Gly482Ser and Thr394Thr variants in the PGC-1alpha gene alter the interaction with MEF2C.</p><p><b>RESULTS</b>Three frequent SNPs (Thr394Thr, Gly482Ser and Thr528Thr) were found in exons of the PGC-1alpha gene. Only the Gly482Ser variant had a different distribution between diabetic patients and healthy subjects, with the 482Ser allele more frequent in patients than in controls (40.1% vs 29.3%, P < 0.01). Even in controls, the 482Ser (A) carriers were more likely to have higher levels of total cholesterol and low-density lipoprotein cholesterol than the 482Gly (G) carriers. The 394A-482G-528A haplotype was associated with protection from diabetes, while the 394A-482A-528A was associated with the susceptibility to diabetes. The bacterial two-hybrid system and site-directed mutagenesis revealed that the 482Ser variant was less efficient than the 482Gly variant to interact with MEF2C, whereas the 394Thr (A) had a synergic effect on the interaction between 482Ser variant and MEF2C.</p><p><b>CONCLUSIONS</b>The results suggested that the 482Ser variant of PGC-1alpha conferred the susceptibility to type 2 diabetes in the southern Chinese population. The underlying mechanism may be attributable, at least in part, to the altered interaction between the different variants (Gly482Ser, Thr394Thr) in the PGC-1alpha gene and MEF2C.</p>

MEF2A gene and susceptibility to coronary artery disease in the Chinese people / 中南大学学报(医学版)

OBJECTIVE@#To explore MEF2A gene and susceptibility to coronary artery disease in the Chinese.@*METHODS@#One hundred seventy-five coronary artery disease (CAD) patients and 228 normal subjects were recruited and their blood samples were amplified to detect sequences of all 11 exons of MEF2A gene by PCR. Single-strand conformational polymorphism (SSCP) analysis was used to detect the mutation. The amplified products were purified and sequenced.@*RESULTS@#The tri-nucleotide (CAG) length polymorphism in the last coding exon of MEF2A in the Chinese was revealed and 4 of the 175 (2.3%) CAD samples containing 4 prolines were due to one proline deletion in MEF2A gene. But all the 228 normal subjects contained 5 prolines. The mutation in both 175 CAD samples and 228 normal subjects was not found in other exons.@*CONCLUSION@#The deletion mutation in exon 11 in MEF2A gene may be related to CAD susceptibility in the Chinese population.

Study on novel mutations of MEF2A gene in Chinese patients with coronary artery disease / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To explore the mutations of MEF2A gene in Chinese patients with coronary artery disease(CAD).</p><p><b>METHODS</b>With polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) and DNA direct sequencing, the mutation analysis of exon 11 of MEF2A gene was performed to 156 patients with CAD and 93 normal controls.</p><p><b>RESULTS</b>By DNA sequence analyzing the samples of abnormal mobility shift of SSCP, the MEF2A gene mutations were found in three patients with CAD. One of mutations was 147130(C>A)(P431Q), and the second one was 21 bases deletion(147108-147128) which was leading to the absence of 7 amino acids (424QQQQQQQ430), and the third was 147191(G>T). Three mutations were all found in one patient, but meanwhile 21 bases deletion was found in the other two patients.</p><p><b>CONCLUSION</b>Mutations in exon 11 of MEF2A gene exist in the patients with CAD, and the mutations may be pathological.</p>