Analysis of DSG2, TTN and GATA4 gene variants in patients with Brugada syndrome from Henan / 中华医学遗传学杂志

OBJECTIVE@#To explore the correlation between DSG2, TTN and GATA4 genes and Brugada syndrome in Henan Province of China.@*METHODS@#From February 2017 to February 2019, 100 patients with Brugada syndrome and 100 healthy individuals were selected as the study and the control groups, respectively. Electrocardiogram and echocardiography were carried out, and peripheral blood samples was collected. Coding regions of DSG2, TTN and GATA4 genes were amplified by PCR and sequenced. The results were compared with standard sequences from GenBank.@*RESULTS@#Electrocardiogram showed that all patients from the study group had ventricular arrhythmia, 87 cases (87%) presented ventricular tachycardia (VT), 84 cases (84%) presented T wave inversion, and 51 cases (51%) presented Epsilon wave. Echocardiography showed that the right ventricle in the study group was enlarged with the inner diameter of the right ventricle being (40.0±13.3) mm, and the right ventricle showed various degree of abnormal systolic function. The enlargement of right atrium accounted for 64%, and the involvement of the left ventricle accounted for 27%. The right ventricular diameter and left ventricular diastolic diameter of the study group were significantly greater than those of the control group (P< 0.05). DNA sequencing showed that 60 patients carried DSG2 gene variants, among which 18 had missense variant of exon 8. Fifty patients carried TTN gene variants, including 8 in the A-band domain and 3 in the I-band domain. Twenty patients carried 3 variants of the GATA4 gene.@*CONCLUSION@#Variants of the DSG2, TTN and GATA4 genes in Henan region are correlated with the onset of Brugada syndrome.

Genetic analysis of a family with congenital heart defects caused by chromosome 8p23.1 deletion / 中华医学遗传学杂志

OBJECTIVE@#To explore the genetic basis for a family affected with congenital heart defects.@*METHODS@#G-banding karyotyping, chromosomal microarray analysis (CMA) and multiplex ligation-dependent probe amplification (MLPA) were carried out to detect copy number variants in a patient with left ventricular noncompaction (LVNC) and his fetus.@*RESULTS@#G-banding karyotyping showed the patient was 45,XY,rob(15;21)(q10;q10)[36]/46,XY[64], while the fetus had an normal karyotype. CMA revealed that both had arr[hg19]8p23.1(11 232 919-11 935 465)×1. MLPA showed both had deletion of all exons of the GATA4 gene.@*CONCLUSION@#The LVNC of the patient and the ventricular septal defect(VSD) of his fetus may result from the same 8p23.1 deletion, for which GATA4 is probably the key gene.

Association of single nucleotide polymorphisms of transcription factors with congenital heart diseases in the Chinese population: a Meta analysis / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To study the association of single nucleotide polymorphisms (SNPs) of transcription factors (NKX2.5, GATA4, TBX5, and FOG2) with congenital heart disease (CHD) in the Chinese population.</p><p><b>METHODS</b>PubMed, Google Scholar, CNKI, Wanfang Data, and Weipu Data were searched for articles on the association of SNPs of target genes with CHD in the Chinese population. If one locus was mentioned in at least two articles, the random or fixed effect model was used to perform a pooled analysis of study results and to calculate the pooled OR and its 95%CI. If a locus was mentioned in only one article, related data were extracted from this article to analyze the association between the SNPs of this locus and CHD.</p><p><b>RESULTS</b>Twenty-three articles were included. The Meta analysis showed that there were significant differences between the CHD and control groups in the genotype and allele frequencies of GATA4 rs1139244 and rs867858 and the genotype frequency of GATA4 rs904018, while there were no significant differences in the SNPs of the other genetic loci between the two groups. The single-article analysis showed that there were significant differences between the two groups in the allele frequencies of NKX2.5 rs118026695/rs703752, GATA4 rs884662/rs12825/rs12458/rs3203358/rs4841588, and TBX5 rs6489956. There were no significant differences in the SNPs of FOG2 locus between the two groups.</p><p><b>CONCLUSIONS</b>The SNPs of some loci in NKX2.5, GATA4, and TBX5 are associated with CHD in the Chinese population, but the association between the SNPs of FOG2 locus and the development of CHD has not been found yet.</p>

Intramyocardial implantation of differentiated rat bone marrow mesenchymal stem cells enhanced by TGF-ß1 improves cardiac function in heart failure rats

The present study tested the hypotheses that i) transforming growth factor beta 1 (TGF-β1) enhances differentiation of rat bone marrow mesenchymal stem cells (MSCs) towards the cardiomyogenic phenotype and ii) intramyocardial implantation of the TGF-β1-treated MSCs improves cardiac function in heart failure rats. MSCs were treated with different concentrations of TGF-β1 for 72 h, and then morphological characteristics, surface antigens and mRNA expression of several transcription factors were assessed. Intramyocardial implantation of these TGF-β1-treated MSCs to infarcted heart was also investigated. MSCs were initially spindle-shaped with irregular processes. On day 28 after TGF-β1 treatment, MSCs showed fusiform shape, orientating parallel with one another, and were connected with adjoining cells forming myotube-like structures. Immunofluorescence revealed the expression of cardiomyocyte-specific proteins, α-sarcomeric actin and troponin T, in these cells. The mRNA expression of GATA4 and Nkx2.5 genes was slightly increased on day 7, enhanced on day 14 and decreased on day 28 while α-MHC gene was not expressed on day 7, but expressed slightly on day 14 and enhanced on day 28. Transmission electron microscopy showed that the induced cells had myofilaments, z line-like substances, desmosomes, and gap junctions, in contrast with control cells. Furthermore, intramyocardial implantation of TGF-β1-treated MSCs to infarcted heart reduced scar area and increased the number of muscle cells. This structure regeneration was concomitant with the improvement of cardiac function, evidenced by decreased left ventricular end-diastolic pressure, increased left ventricular systolic pressure and increased maximal positive pressure development rate. Taken together, these results indicate that intramyocardial implantation of differentiated MSCs enhanced by TGF-β1 improved cardiac function in heart failure rats.

Experimental studies on the role of GATA4 in the endocardial cushions development / 中华心血管病杂志

<p><b>OBJECTIVE</b>To investigate the role of GATA4 gene in the endocardial cushions development.</p><p><b>METHODS</b>Target gene eukaryote expression vectors were constructed by pcDNA3.1(-) vector plasmid, and were identified by DNA sequence analysis. Recombinant plasmids were transfected into Hela cells with lipofectamine 2000, meanwhile Hela cells transfected with empty vector or those without transfection served as transfection control group and blank control group, respectively. Real-time PCR and Western blot were performed to detect the relative expression of mRNA and protein of transcription factors GATA4, Sox9, Scleraxis and ECM proteins Aggrecan, Tenascin in each group.</p><p><b>RESULTS</b>The relative mRNA expression of GATA4 in experimental group was significantly higher than in transfection control group and blank control group. GATA4 mRNA expression in Hela(GATA4), Hela(H436Y), Hela(Null) and Hela group was 310.83 ± 2.39, 146.35 ± 1.74, 0.94 ± 0.32, 1.00 ± 0.28, respectively (F = 72.508, P < 0.05). Western blot results were consistent with the results obtained by qRT-PCR. The relative mRNA and protein expressions of Sox9, Scleraxis, Aggrecan and Tenascin in both experimental groups were significantly higher than that in transfection control group and blank control group (P < 0.05), and above gene expressions were significantly downregulated in GATA4(H436Y) group, while they were similar between transfection control group and blank control group (all P > 0.05).</p><p><b>CONCLUSIONS</b>GATA4 H436Y mutation reduces it's transcriptional activation, which might serve as a theoretical framework to demonstrate the roles of GATA4 gene in endocardial cushion development.</p>

Post-transcriptional protein modification of Gata4 / 中国当代儿科杂志

Gata4 is an important transcription factor in heart development. Gata4 post-transcriptional protein modification regulates transcriptional activity and DNA binding, which in turn affects expression of downstream genes and transcription factors, differentiation of embryonic stem cells and cardiogenesis. This article summarizes the effect of post-transcriptional protein modification on transcriptional activity of Gata4 and the relationship between this effect and congenital heart disease. It was shown that acetylation, phosphorylation and SUMOylation upregulate transcriptional activity, DNA binding, downstream gene expression and embryonic stem cell differentiation. On the other hand, methylation and deacetylation downregulate Gata4 transcriptional activity. Post-transcriptional protein modification of Gata4 is very important in clinical research on congenital and other heart diseases.

The mechanism underlying the differentiation of human umbilical cord-derived mesenchymal stem cells into myocardial cells induced by 5-azacytidine.

Objective: To investigate the molecular mechanism underlying the differentiation of human umbilical cord-derived mesenchymal stem cells (hUCMSCs) into myocardial cells induced by 5-azacytidine (5-aza), and to explore the expression and significance of DLL4-Notch signaling in this process. Materials and Methods: hUCMSCs were isolated and purified from the umbilical cords of normal or cesarean term deliveries under sterile conditions. After treatment with 5-aza for 24 h, hUCMSCs was continued to culture, the expression of GATA4 and NKx2.5 at 4 weeks after induction, DLL4 and Notch1 mRNA at 1d, 3d, 5d, 7d after induction were detected. The expression of cardiac troponin I (cTnI) after 4 weeks was determined by immunocytochemistry. Results: hUCMSCs treated with 5-aza were stained positively for cTnI 4 weeks after induction. The expression of Notch1 and DLL4 mRNA in the 5-aza-induced group was stable and significantly higher than that in the control group (mean Ct value for the Notch1 gene: 0.51 ± 0.21 in the 5-aza-induced group vs. 7.85 ± 0.35 in the control group; mean Ct value for the DLL4 gene: 1.60 ± 0.49 in the 5-aza-induced group vs. 12.42 ± 0.73 in the control group). Similar results were observed for Nkx2.5 and GATA4 genes. The expressions of Nkx2.5 and GATA4 mRNA in the 5-aza group were 4.72 ± 0.58 and 3.76 ± 0.06 times higher than that in the control group, respectively, with statistical significance. Conclusions: hUCMSCs can be differentiated into myocardial cells by 5-aza induction in vitro. 5-Aza may affect this process by regulating the expression of GATA4 and Nkx2.5 genes. The DLL4-Notch signal pathway may be involved in this process.

Novel GATA4 mutations identified in patients with congenital atrial septal defects / 中华心血管病杂志

<p><b>OBJECTIVE</b>To identify the genetic defects in patients with congenital atrial septal defects (ASD).</p><p><b>METHODS</b>The clinical data and blood samples from 180 unrelated subjects with congenital ASD were collected and evaluated. Two hundred healthy individuals served as controls. The coding exons and the flanking introns of GATA4 gene were amplified by polymerase chain reaction and sequenced using the di-deoxynucleotide chain termination approach. The acquired sequences were aligned with the sequences publicized in GenBank by the aid of programme BLAST to identify the sequence variations. Clustal W software was applied for analysis of the conservation of altered amino acids.</p><p><b>RESULTS</b>Two novel heterozygous missense GATA4 mutations were identified in 2 out of 180 ASD patients. Namely, the triplet substitutions of GTC for GGC at codon 21 and TCG for CCG at codon 87 were detected, predicting the conversions of glycine into valine at amino acid residue 21 (G21V) and proline into serine at amino acid residue 87 (P87S). None of the two mutations were detected in 200 healthy controls. Across-species alignment of GATA4 encoded protein sequences displayed that the mutated amino acids were highly conserved evolutionarily. Additionally, a single nucleotide polymorphism c.99G>T was observed. However, the polymorphic frequency distribution in ASD cases was similar with that in healthy controls (for genotype GT, χ(2) = 0.7556, P = 0.3847; for allele T, χ(2) = 0.7235, P = 0.3950).</p><p><b>CONCLUSIONS</b>Two novel mutations of GATA4 gene are identified in two unrelated ASD patients. This finding provides new insight into the molecular etiology responsible for ASD.</p>

Exogenous Nkx2-5 gene expression induces the expression of cardiac markers during P19 cell differentiation in vitro / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the role of homeobox gene Nkx2-5 in cardiac myogenesis.</p><p><b>METHODS</b>Two P19 cell lines, namely cells transfected with exogenous expression of Nkx2-5 gene and non-transfected cells, were cultured in suspension for 4 days to induce cell aggregation, and the cell aggregates were transferred to the Petri dish for further adherent culture. On days 4, 8, 12 and 16 of adherent culture, the expressions of α-sarcomeric actin (α-SA) and cardiac troponin T (cTnT) protein were detected by immunocytochemistry, and the mRNA expressions of GATA-4, α-myosin heavy chain (α-MHC) and atrial natriuretic factor (ANF) genes by RT-PCR.</p><p><b>RESULTS</b>In the transfected cells, α-SA and cTnT protein expressions were detected on days 8, 12 and 16 of adhere culture, and their expressions increased gradually with time. α-SA and cTnT expression was significantly higher on day 16 than on day 8 of culture (P<0.01). RT-PCR analysis of the transfected cell showed the presence of GATA-4 expression on day 4 of adherent culture, and the expression increased on days 8 and 12 but decreased on day 16. ANF and α-MHC expressions were found on days 8, 12, and 16, increasing gradually over time and showing significant differences from those on day 4 (P<0.05 or P<0.01). The expression of α-MHC was significantly higher on days 12 and 16 than on day 8 (P<0.05 or P<0.01), and ANF expression was significantly higher on day 16 than on days 8 and 12 (P<0.01). The non-transfected cells were negative for the expressions of all these genes.</p><p><b>CONCLUSION</b>Exogenous expression of Nkx2-5 gene can induce P19 cells to express cardiac markers in vitro.</p>

Determination of GATA-4 in the testis of the mouse / 中华男科学杂志

<p><b>OBJECTIVE</b>To explore the characteristics and distribution of GATA-4 in the testis of male mice.</p><p><b>METHODS</b>Paraffin sections were obtained from the testes of 24 male B6SJLF1/J mice, aged 0 day (n = 6), 2 weeks (n = 6), 4 weeks (n = 6) and 6 weeks (n = 6), and the expressions of GATA-4 in the testis were observed by the immunohistochemical ABC method and DAB visualization at different times.</p><p><b>RESULTS</b>Positive expressions of GATA4 were found in the Sertoli cells and Leydig cells of all the mice, but significantly higher in the 4- and 6-week-old than in the 0-day and 2-week-old groups (P < 0.01). And they were also observed in the germ cells of the 4- and 6-week-old mice, significantly higher in the latter than in the former (P < 0.01).</p><p><b>CONCLUSION</b>GATA-4 exists in the testis of male mice, which has provided a morphological base for sex determination and differentiation and hormone regulation in the testis.</p>

A novel GATA4 mutation leading to congenital ventricular septal defect / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To identify the GATA4 gene mutation of congenital ventricular septal defect (VSD) and study the molecular mechanism of a novel mutation.</p><p><b>METHODS</b>The clinical data and blood samples from 185 unrelated subjects with congenital VSD were collected and evaluated together with 200 healthy individuals. The coding exons and the flanking intron regions of the GATA4 gene were amplified by PCR and sequenced using the di-deoxynucleotide chain termination approach. The GATA4 gene was cloned and the corresponding mutant was acquired by site directed mutagenesis. The recombinant plasmid expressing GATA4 and the reporter vector expressing enhanced green fluorescence protein (EGFP) driven by the promoter of atrial natrium peptide (ANP) gene were transfected into HeLa cells with Lipofectamine. The effect of mutated GATA4 gene on the transcriptional activity of encoded transcriptional factor was analyzed by reverse transcription (RT)-PCR.</p><p><b>RESULTS</b>A novel heterozygous missense GATA4 mutation, c.191G>A was identified in 1 VSD patient. The mutation leads to glycine to glutamic acid change at amino acid residue 64 (G64E) in the GATA4 protein. Functional analysis showed that GATA4 G64E mutation decreased the transcriptional activity of GATA4 transcriptional factor.</p><p><b>CONCLUSION</b>A novel heterozygous missense GATA4 mutation, G64E, was identified in 1 VSD patient. The mutation might cause VSD by impairing the transcriptional activity of GATA4 transcriptional factor.</p>

Genetic screening for novel GATA4 mutations associated with congenital atrial septal defect / 中华心血管病杂志

<p><b>OBJECTIVE</b>To screen the gene GATA4 for novel mutations associated with congenital atrial septal defect (ASD).</p><p><b>METHODS</b>The clinical data and peripheral venous blood specimen from 85 unrelated subjects with congenital ASD were collected and analyzed in contrast to 200 healthy individuals. The coding exons and the exon/intron boundaries of GATA4 gene were amplified by polymerase chain reaction and sequenced using the di-deoxynucleotide chain termination procedure. The obtained sequences were aligned with those publicized in GenBank with the help of programme BLAST to identify the sequence variations. The software Clustal W was applied to analysis of the conservation of altered amino acids.</p><p><b>RESULTS</b>Three novel heterozygous missense GATA4 mutations were identified in 3 of 85 ASD patients, respectively. Namely, the triplet substitutions of ATG for GTG at codon 267, GCC for ACC at codon 354, and CAA for CCA at codon 407, predicting the conversions of valine into methionine at amino acid residue 267 (V267M), threonine into alanine at amino acid residue 354 (T354A), and proline into glutamine at amino acid residue 407 (P407Q), were identified. No mutation was detected in 200 healthy controls. A cross-species alignment of GATA4 encoded protein sequences showed that the valine at amino acid residue 267 and proline at amino acid residue 407 were completely conserved evolutionarily.</p><p><b>CONCLUSION</b>Three novel heterozygous missense GATA4 mutations were identified in patients with congenital ASD, which reveals new molecular etiology responsible for ASD, and contributes to the early prophylaxis and therapy for ASD.</p>

The GATA family in reproduction / 中华男科学杂志

The GATA family proteins are a group of zinc finger transcription factors that are expressed in human and mammalian animals and play an important role in mammalian organ morphogenesis, cell proliferation and sex differentiation. GATA-4 and GATA-6 have been identified in the ovaries and testes of humans, mice, pigs and chickens. GATA-4 contributes to fetal male gonadal development by regulating the genes that mediate Müllerian duct regression and the onset of testosterone production. GATA-4 and GATA-6 are localized in and regulate the function of the ovarian and testicular somatic cells of fetal mice, especially granulosa cells, thecal cells, Sertoli cells and Leydig cells. GATA-4 is also present in the germ cells of fetal and prepubertal mice.

GATA4 and NKX2.5 gene analysis in Chinese Uygur patients with congenital heart disease / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Congenital heart disease (CHD) is the most common developmental anomaly in newborns. The germline mutations in GATA4 and NKX2.5 genes have been identified as responsible for CHD. The frequency of GATA4 and NKX2.5 mutations in Chinese Uygur patients with CHD and the correlation between their genotype and CHD phenotype are unknown.</p><p><b>METHODS</b>We examined the coding region of GATA4 and NKX2.5 genes in 62 Chinese Uygur patients with CHD and 117 Chinese Uygur individuals as the controls by denaturing high performance liquid chromatography (DHPLC) and sequencing.</p><p><b>RESULTS</b>Two heterozygous missense mutations of c.1220C > A and c.1273G > A in GATA4 gene, which cause the amino acid residue changes of P407Q and D425N in GATA4, were found in a patient with tetralogy of Fallot and a patient with ventricular septal defect, respectively. The two patients did not have atrioventricular conduct defects or non-cardiac abnormalities. The two mutations are expected to affect the protein function. There were no reported NKX2.5 mutations in the patients.</p><p><b>CONCLUSION</b>Our results provided the primary data on CHD phenotype associated with GATA4 mutation in the Chinese Uygur population.</p>

Association between GATA-4 mutations and congenital cardiac septal defects in Han Chinese patients / 中华心血管病杂志

<p><b>OBJECTIVE</b>To elucidate the association between GATA-4 gene mutations and congenital cardiac septal defects in Han Chinese patients.</p><p><b>METHODS</b>Fifty Han Chinese patients with congenital cardiac septal defects and 100 normal subjects with the same ethnical background were studied. Total six exons and the intron-exon boundaries of GATA-4 were amplified by the polymerase chain reaction. The polymerase chain reaction products were purified and directly sequenced with automatic sequencer.</p><p><b>RESULTS</b>Two novel heterozygous mutations were discovered in the GATA-4 gene of patients with congenital cardiac septal defects, His28Tyr in exon 2 and His436Tyr in exon 7 respectively, which were absent in the control population and not reported in the SNP database (http://www.ncbi.nlm.nih.gov/SNP).</p><p><b>CONCLUSION</b>Our finding suggests that the mutations in the transcription factor GATA-4 may be related to congenital cardiac septal defects in Han Chinese patients.</p>

Preliminary functional analysis of a novel mutation in GATA-4 gene in Chinese patients with congenital cardiac septal defects / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To perform the functional analysis of a novel H436Y mutation of GATA-4 gene identified in Han Chinese patients with congenital cardiac septal defects.</p><p><b>METHODS</b>Using bioinformatics to predict if the H436Y mutation in the GATA-4 gene affects its protein function. H436Y mutation in the GATA-4 gene was generated by Quick Change Lightning site-directed mutagenesis kit and verified by DNA sequencing. GATA-4-wt or GATA-4-mut DNA was cotransfected into Hela cells with DNA for the luciferase reporter gene atrial natriuretic factor (ANF), and luciferase activity was measured by an LKB luminometer 48 h after transient transfection.</p><p><b>RESULTS</b>Alignment of the GATA-4 amino acid sequence indicated that the histidine residue at position 436 was conserved, and H436Y mutation in the GATA-4 gene is expected to affect its protein function. The H436Y mutation significantly reduced the transcriptional activation of downstream reporter ANF when compared to wild-type GATA-4 (P<0.01).</p><p><b>CONCLUSION</b>The mutation c.1306C-->T of the GATA-4 gene impaired the activation of the downstream target, suggesting that the H436Y mutation in the C-terminal region of the GATA-4 gene might prevent its biological function.</p>

In vitro cardiogenesis can be initiated in human CD34+ cells.

BACKGROUND: The extensive damage that occurs in the cardiac tissue after myocardial infarct is the major concern in post infarct management. It is very well known that adult stem cells mobilized by administration of G-CSF result in homing of stem cells into the damaged myocardium. This is because of the fact that stem cells have the ability to proliferate and capacity to generate into multiple cell lineages. METHOD: A healthy donor was selected as per the guidelines given by the institutional ethical committee and Helsinki declaration. The donor was given G-CSF 5 microg/kg/day and stem cells were harvested from the peripheral blood using Fresenius ASTec204 cell separator. The PBSC were then evaluated by immunohistochemical staining using anti-human CD34 monoclonal antibodies. The cells were then cultured in DMEM with 10% FCS for 17 weeks and in vitro cardiogenesis was initiated by adding 4 microM/l 5'Azacytidine. RESULTS: In vitro cardiogenesis was initiated in pure CD34+ cells with 5' Azacytidine. The cells showed spontaneous beating after 24 hours of treatment and after 5 weeks, the cells connected with the adjoining cells by a myotube. In these cells, expression of myosin light chain (MLC2v) gene and GATA-4 transcription factor validated the development of cardiomyocytes. CONCLUSION: It is observed that the transplantation of autologous stem cells/fetal cardiomyocytes in the heart scar tissue developed due to infarct, limited the scar expansion, and prevented post infarct heart failures. Homing process due to the transplantation of autologous stem cells is time consuming; therefore, transplantation of cardiomyocytes developed from autologous stem cells could be the future method of correcting the infracted myocardium.

Hepatocyte growth factor combined with insulin like growth factor-1 improves expression of GATA-4 in mesenchymal stem cells cocultured with cardiomyocytes / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>In a suitable microenvironment, bone marrow mesenchymal stem cells (BMSCs) can transdifferentiate into myocardial cells whose special gene can be expressed as structural proteins. Growth factor (GF) plays an important role in the cell migration, survival and differentiation. However, the effect of GF on the cellular differentiation is not well understood. In this study, the hepatocyte growth factor (HGF) and insulin like growth factor-1 (IGF-1) were used in the mixed culture of BMSCs and myocardial cells and the effects of these growth factors on the GATA-4 expression of BMSCs were investigated.</p><p><b>METHODS</b>BMSCs were isolated from the marrow of rabbit femurs and tibias and foetal rabbit ventricular myocytes were isolated with trypsin sequential digestion. These two kinds of cells were cocultured in a ratio of 1:1 for 6 weeks; cocultured cells with added HGF and IGF-1 were the experimental group. The differentiated BMSCs were collected using the laser capture, microdissection system and their RNA isolated. Immunocytochemical staining, transmission electron microscopy and reverse transcription-polymerase chain reaction were used to evaluate the transformation of the stem cells into cardiomyocytes like cells.</p><p><b>RESULTS</b>When cultured separately, BMSCs did not express alpha-actin and the stem cells had many nucleoli. However, when cocultured with cardiomyocytes, BMSCs expressed alpha-actin and the cardiac transcription factor GATA-4 and showed cardiomyocyte like ultrastructure. In comparison with the control group, the experimental group exhibited the enhanced expression level of GATA-4. The GATA-4 expression of BMSCs increased gradually following the addition of HGF and IGF-1, reached the maximal level after two weeks and decreased slightly thereafter.</p><p><b>CONCLUSIONS</b>BMSCs can transdifferentiate into cardiomyocytes like cells and express the cardiac transcription factor GATA-4 after being cocultured with myocardial cells. HGF and IGF-1 can stimulate transdifferentiation of BMSCs into cardiac phenotype and enhance the expression of GATA-4. These results indicate that growth factors have a great potential in clinical cellular therapy.</p>

Isolation, characterization and genetic analysis of canine GATA4 gene in a family of Doberman Pinschers with an atrial septal defect.

GATA4 is expressed early in the developing heart where it plays a key role in regulating the expression of genes encoding myocardial contractile proteins. Gene mutations in the human GATA4 have been implicated in various congenital heart defects (CHD), including atrial septal defect (ASD). Although ASD is the third most common CHD in humans, it is generally rare in dogs and cats. There is also no obvious predilection for ASD in dogs and cats, based on sex or breed. However, among dogs, the incidence rate of ASD is relatively high in Samoyeds and Doberman Pinschers, where its inheritance and genetic aetiology are not well understood. In this study, we identified and investigated the genetic aetiology of an ASD affected family in a pure breed dog population. Although the GATA4 gene was screened, we did not find any mutations that would result in the alteration of the coding sequence and hence, the predicted GATA4 structure and function. Although the aetiology of ASD is multifactorial, our findings indicate that GATA4 may not be responsible for the ASD in the dogs used in this study. However, this does not eliminate GATA4 as a candidate for ASD in other dog breeds.

Effects of endothelin-1 on differentiation of cardiac myocyte induced from rabbit bone marrow stromal cells / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Cardiomyocyte transplantation for the therapy of myocardial ischaemia is being paid close attention. However, how the microenvironment controls the differentiation of transplanted bone marrow stromal cells (BMSCs) is unknown. Endothelin-1 (ET-1), a cytokine, increases during myocardial infarction, but it is not known whether ET-1 is responsible for the fate of transplanted BMSCs. In the present study, we investigated the effects of ET-1 on differentiation and maturation of induced rabbit BMSCs, in vitro, to elucidate the cellular biological mechanisms.</p><p><b>METHODS</b>The proliferation of BMSCs isolated from femur of rabbits was induced by ET-1 only, by 5-azacytidine (5-aza) or ET-1 combined with 5-aza. After 4 weeks of induced culturing, the differentiation rate and the diameter of induced myocyte like cells were estimated and the expressions of GATA-4 protein and phosphorylation level were assayed by Western-blot, RT-PCR analysis of beta-myosin heavy chain (MHC). mRNA expression, levels of troponin-I by immunohistochemical staining and ultrastructure of induce-cultured BMSCs were also determined.</p><p><b>RESULTS</b>By induction with ET-1 and 5-aza, mean cell diameter of induced BMSCs was larger than induced with 5-aza [(6.26 +/- 0.22) microm cf (5.29 +/- 0.19) microm] (P < 0.001). There was no difference in rate of differentiation of myocyte like cells between the groups induced with 5-aza and ET-1 combined with 5-aza [(29.82 +/- 0.23)% cf (29.94 +/- 0.18)%] (P > 0.05). The expressions of GATA-4 protein and phosphorylation were enhanced significantly in groups induced with ET-1 combined with 5-aza (P < 0.05). In the group induced with ET-1 combined with 5-aza, expression of beta-MHC mRNA was higher than control [(0.122 +/- 0.008) cf (0.022 +/- 0.003)] (P < 0.01), and more troponin-I positive cells were also detected in this group. Differentiated BMSCs showed formations of myofilaments and primitive sarcomere, i.e., morphological characteristics of myocyte like cells.</p><p><b>CONCLUSIONS</b>This study suggests that induced culturing of BMSCs by ET-1 combined with 5-aza can express cardiomyocytic characteristics whereas ET-1 alone could not induce BMSCs to differentiate to myocyte like cells. ET-1 upregulates the expression of GATA-4 protein and phosphorylation level of induced BMSCs, and rapidly promotes the differentiation and maturation of myocyte like cells from BMSCs.</p>