Jie Tian

Chongqing Medical University, Ch’ung-ch’ing-shih, Chongqing Shi, China

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Publications (32)90.63 Total impact

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    ABSTRACT: Diastolic dysfunction refers to an impaired relaxation and an abnormality in ventricular blood filling during diastole while systolic function is preserved. Cardiac myofibril hypersensitivity to Ca(2+) is a major factor that causes impaired relaxation of myocardial cells. The present study investigates the effect of the green tea extract catechins on myofibril calcium desensitization and restoration of diastolic function in a restrictive cardiomyopathy (RCM) mouse model with cardiac troponin mutations. Wild type (WT) and RCM mice were treated daily with catechin (epigallocatechin-3-gallate, EGCg, 50mg/kg body weight) for 3months. Echocardiography and cell based assays were performed to measure cardiac structure and flow-related variables including chamber dimensions, fraction shortening, trans-mitral flow patterns in the experimental mice. In addition, myocyte contractility and calcium dynamics were measured in WT and RCM cardiomyocytes treated in vitro with 5μM EGCg. Our data indicated that RCM mice treated with EGCg showed an improved diastolic function while systolic function remained unchanged. At the cellular level, sarcomere relaxation and calcium decay were accelerated in RCM myocardial cells treated with EGCg. These results suggest that catechin is effective in reversing the impaired relaxation in RCM myocardial cells and rescuing the RCM mice with diastolic dysfunction. Copyright © 2015. Published by Elsevier Inc.
    Archives of Biochemistry and Biophysics 03/2015; 573. DOI:10.1016/j.abb.2015.03.015 · 3.04 Impact Factor
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    ABSTRACT: The expression of cardiac genes is precisely regulated, and any perturbation may cause developmental defects. In a previous study, we demonstrated that alcohol consumption during pregnancy could lead to uncontrolled expressions of cardiac genes and eventually result in cardiac dysplasia. However, the underlying mechanisms remain unclear. In the present study, we have investigated the alcohol-induced cardiac hypertrophy and its potential mechanisms. Furthermore, the protective effect of anacardic acid against the alcohol-induced cardiac hypertrophy has been explored in experimental mice. C57BL/6 pregnant mice were gavaged with 56% ethanol or saline and the hearts of their fetus were collected for analysis. Binding of p300, CBP, PCAF, SRC1, except GCN5, were increased to the NKX2.5 promoter in fetal mouse hearts exposed to alcohol. Increased acetylation of H3K9 and increased mRNA expression of NKX2.5, β-MHC and Cx43 were observed in the same samples. Treatment with a pan-acetylase inhibitor, anacardic acid, reduced the binding affinity of p300 and PCAF to the NKX2.5, β-MHC, Cx43 promoters and attenuated H3K9 hyperacetylation. Interestingly, anacardic acid down-regulated over-expression of these cardiac genes induced by alcohol and ultimately attenuated ethanol-induced cardiac hypertrophy in fetal mice. Our results indicate that alcohol exposure during pregnancy could lead to fetal cardiac hypertrophy. The over-expression of NKX2.5, β-MHC, Cx43 mediated by p300 and PCAF may be critical mechanisms of alcohol-induced cardiac hypertrophy. Anacardic acid can down-regulate the over-expression of cardiac genes and reverse cardiac hypertrophy caused by alcohol treatment in pregnant mice, suggesting it could be a potential therapeutic agent for the treatment of cardiac hypertrophy. Copyright © 2015. Published by Elsevier B.V.
    Biochimie 03/2015; DOI:10.1016/j.biochi.2015.03.012 · 3.12 Impact Factor
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    ABSTRACT: Cardiac gene expression regulation is controlled not only by genetic factors but also by environmental, i.e., epigenetic factors. Several environmental toxic effects such as oxidative stress and ischemia can result in abnormal myofibril gene expression during heart development. Troponin, one of the regulatory myofibril proteins in the heart, is a well-known model in study of cardiac gene regulation during the development. In our previous studies, we have demonstrated that fetal form troponin I (ssTnI) expression in the heart is partially regulated by hormones, such as thyroid hormone. In the present study, we have explored the epigenetic role of histone modification in the regulation of ssTnI expression. Mouse hearts were collected at different time of heart development, i.e., embryonic day 15.5, postnatal day 1, day 7, day 14 and day 21. Levels of histone H3 acetylation (acH3) and histone H3 lysine 9 trimethylation (H3K9me(3)) were detected using chromatin immunoprecipitation assays in slow upstream regulatory element (SURE) domain (TnI slow upstream regulatory element), 300-bp proximal upstream domain and the first intron of ssTnI gene, which are recognized as critical regions for ssTnI regulation. We found that the levels of acH3 on the SURE region were gradually decreased, corresponding to a similar decrease of ssTnI expression in the heart, whereas the levels of H3K9me(3) in the first intron of ssTnI gene were gradually increased. Our results indicate that both histone acetylation and methylation are involved in the epigenetic regulation of ssTnI expression in the heart during the development, which are the targets for environmental factors.
    Cardiovascular Toxicology 10/2014; DOI:10.1007/s12012-014-9278-7 · 2.06 Impact Factor
  • Yang Xu, Jie Tian, Xupei Huang
    10/2014; 1(2). DOI:10.5176/2345-7201_1.2.22
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    ABSTRACT: Background Alcohol abuse during gestation may cause congenital heart diseases (CHDs). The underlying mechanisms of alcohol-induced cardiac deformities are still not clear. Recent studies suggest that histone modification may play a crucial role in this pathological process. Moreover, our previous studies reported that ethanol could induce histone3 lysine9 (H3K9) hyperacetylation and overexpression of heart development-related genes in vitro. The aim of this study was to investigate the effect of alcohol consumption during gestation on the imbalance of H3K9 acetylation and the alternation of the expression of heart development-related genes during cardiogenesis.Methods Pregnant mice were exposed to a single dose of alcohol (10 μl/g/d, 56% alcohol) by gavage every day in the morning from embryo day 7.5 (E7.5) to E15.5. Hematoxylin and eosin (H&E) staining was applied for observing the structure of the embryonic hearts. Western blotting and quantitative real-time polymerase chain reaction were used for detecting the level of H3K9 acetylation and gene expression. Histone acetyltransferase (HAT) and histone deacetylase (HDAC) activities were detected by colorimetric assay and fluorometric assay.ResultsH&E staining of cardiac tissue showed abnormalities of embryonic hearts at E17.5. The level of H3K9 acetylation reached peak at E17.5 and decreased sharply to a low level at birth and maintained at low level afterward. Alcohol exposure increased H3K9 acetylation at E11.5, E14.5, E17.5, and E18.5, respectively (p < 0.05), and enhanced the expression of Gata4 in the embryonic hearts at E14.5 and E17.5, Mef2c at E14.5, and Nkx2.5 at E14.5 and E17.5, (p < 0.05) but not for Tbx5 (p > 0.05). On embryonic day 17.5, HAT activities of embryonic hearts increased significantly, however alcohol exposure did not alter HDAC activities.Conclusions These data indicate a time course of H3K9 acetylation change during heart development and demonstrate that alcohol exposure in utero may induce an increase of HAT activities, which results in H3K9 hyperacetylation and an increase of the expression of heart development-related genes. These findings reveal a novel epigenetic mechanism that connects the alcohol consumption during the pregnancy and the development of CHD in the fetus.
    Alcoholism Clinical and Experimental Research 09/2014; 38(9). DOI:10.1111/acer.12518 · 3.31 Impact Factor
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    ABSTRACT: Background Cardiovascular malformations can be caused by abnormalities in Gata4 expression during fetal development. In a previous study, we demonstrated that ethanol exposure could lead to histone hyperacetylation and Gata4 over-expression in fetal mouse hearts. However, the potential mechanisms of histone hyperacetylation and Gata4 over-expression induced by ethanol remain unclear. Methods and Results Pregnant mice were gavaged with ethanol or saline. Fetal mouse hearts were collected for analysis. The results of ethanol fed groups showed that global HAT activity was unusually high in the hearts of fetal mice while global HDAC activity remained unchanged. Binding of P300, CBP, PCAF, SRC1, but not GCN5, were increased on the Gata4 promoter relative to the saline treated group. Increased acetylation of H3K9 and increased mRNA expression of Gata4, α-MHC, cTnT were observed in these hearts. Treatment with the pan-histone acetylase inhibitor, anacardic acid, reduced the binding of P300, PCAF to the Gata4 promoter and reversed H3K9 hyperacetylation in the presence of ethanol. Interestingly, anacardic acid attenuated over-expression of Gata4, α-MHC and cTnT in fetal mouse hearts exposed to ethanol. Conclusions Our results suggest that P300 and PCAF may be critical regulatory factors that mediate Gata4 over-expression induced by ethanol exposure. Alternatively, P300, PCAF and Gata4 may coordinate over-expression of cardiac downstream genes in mouse hearts exposed to ethanol. Anacardic acid may thus protect against ethanol-induced Gata4, α-MHC, cTnT over-expression by inhibiting the binding of P300 and PCAF to the promoter region of these genes.
    PLoS ONE 08/2014; 9(8):e104135. DOI:10.1371/journal.pone.0104135 · 3.53 Impact Factor
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    ABSTRACT: Prenatal alcohol exposure leads to congenital heart abnormal development, its mechanisms are still unknown. Recent reports have associated alcohol exposure with histone H3 acetylation. In the present study, we have performed the experiments to test the hypothesis that histone H3K14 acetylation is the key role in the fetal heart leads to over-expression of cardiac specific genes DHAND and EHAND caused by prenatal alcohol exposure. Seventy pregnant C57BL/6 mice were divided randomly into seven groups (n = 10). They were the untreated group, dimethyl sulfoxide group, alcohol exposure group, curcumin treatment group, both alcohol and curcumin treatment group, SAHA treatment group, both alcohol and SAHA treatment group. Fetal mouse hearts were collected on embryonic day 14.5. The changes of HATs activities, the acetylation levels of histone H3K14 (H3K14ac), the expression levels of cardiac specific genes DHAND and EHAND, and structure of chromatin were determined. Our data indicates that curcumin and SAHA significantly reduces and increases the activities of HATs and the levels of histone H3K14ac in fetal hearts respectively. The expression of DHAND and EHAND is significantly down-regulated and up-regulated in the groups treated with curcumin and SAHA. Furthermore, our results from ChIP assays have shown that the histone H3K14ac connects with the DHAND and EHAND genes are significantly inhibited by curcumin and simulated by SAHA. Our study suggests that prenatal alcohol exposure causes the over-expression of DHAND and EHAND by increasing H3K14ac in mice.
    Toxicology Letters 08/2014; DOI:10.1016/j.toxlet.2014.05.011 · 3.36 Impact Factor
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    ABSTRACT: BMP2 signal pathway play critical roles during heart development,Smad4 encodes the only common Smad protein in mammals, which is a pivotal nuclear mediator. Our previous studies showed that BMP2 enhanced the expression of cardiac transcription factors in part by increasing histone H3 acetylation. In the present study, we tested the hypothesis that Smad4 mediated BMP2 signal pathway is essential for the expression of cardiac core transcription factors by affecting the histone H3 acetylation. We successfully constructed an lentiviral-mediated short hairpin RNA interference vector targeting Smad4 (Lv-Smad4) in rat H9c2 embryonic cardiac myocytes (H9c2 cells) and demonstrated that it suppressed the expression of the Smad4 gene. Cultured H9c2 cells were transfected with recombinant adenoviruses expressing human BMP2 (AdBMP2) with or without Lv-Smad4. Quantitative real-time RT-PCR analysis showed that knocking down of Smad4 substantially inhibited both AdBMP2-induced and basal expression levels of cardiac transcription factors GATA4 and Nkx2.5, but not MEF2c and Tbx5. Similarly, chromatin immunoprecipitation(ChIP) analysis showed that knocking down of Smad4 inhibited both AdBMP2-induced and basal histone H3 acetylation levels in the promoter regions of GATA4 and Nkx2.5, but not of Tbx5 and MEF2c. In addition, Lv-Smad4 selectively suppressed AdBMP2-induced expression of HAT p300, but not HAT GCN5 in H9c2 cells. The data indicated that inhibition of Smad4 diminished both AdBMP2 induced and basal histone acetylation level in the promoter regions of GATA4 and Nkx2.5,suggesting that Smad4 mediated BMP2 signal pathway was essential for the regulation of GATA4 and Nkx2.5 by affecting the histone H3 acetylation in H9c2 cells.
    Biochemical and Biophysical Research Communications 05/2014; 450(1). DOI:10.1016/j.bbrc.2014.05.068 · 2.28 Impact Factor
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    ABSTRACT: 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. 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. 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. 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.
    Zhongguo dang dai er ke za zhi = Chinese journal of contemporary pediatrics 04/2014; 16(4):418-23.
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    ABSTRACT: Objective: We have evaluated 106 pediatric cases of infective endocarditis (IE) to elucidate clinical manifestations and pathogenic microorganism profiling of IE in China. Methods: Clinical features, complications, pathogenic microorganisms, diagnosis and treatment of pediatric IE were reviewed in two groups of patients with IE from the different periods of time (group A, 34 cases obtained in the period from 2000 to 2011 and group B, 72 cases obtained in the period from 1964 to 1999). Results: A total of 106 pediatric patients with a definite diagnosis of IE based on the modified Duke criteria were enrolled and evaluated in this study. By comparing two groups of patients from different time periods, we found that the incidence of rheumatic heart disease was significantly reduced (from 19.4 to 5.9%), whereas congenital heart disease-associated IE had a tendency to increase (from 55.6 to 79.4%). Staphylococcus aureus was detected as the most common pathogenic microorganism, and its involvement tended to increase (from 32.0 to 58.5%), whereas the percentage of infections caused by Streptococcus viridans (8.0%) had not changed. It was interesting to note that the rate of vegetations detected was increased from 50.0 to 67.6% and the incidence of right-sided IE was also increased (from 35.0 to 60.9%). The most common valves involved in recent cases were tricuspid valves (increase from 30.0 to 47.8%), while mitral valve infection was reduced (from 60.0 to 39.1%). Penicillin was still the most commonly used antibiotic for the treatment of IE; the combination of penicillin plus cephalosporin has been recommended more and more recently. Conclusions: Comparing pediatric IE patients during the past 40 years, we found that the role of rheumatic heart disease as a predisposing factor is diminishing. Pediatric IE is still predominantly caused by staphylococci. The most commonly involved valves are tricuspid valves instead of mitral valves. Gram-positive bacteria showed an increased resistance to penicillin when used alone, and the use of combination treatment with antibiotics is increasing in the area. © 2014 S. Karger AG, Basel.
    Cardiology 03/2014; 128(2):88-91. DOI:10.1159/000358040 · 2.04 Impact Factor
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    ABSTRACT: The aim of the present study was to investigate the effects of Islet-1 on the process of mesenchymal stem cell (MSC) differentiation into cardiomyocyte-like cells and to elucidate the possible mechanisms involved. Lentiviral vectors expressing Islet-1 (Lenti-Islet-1) were constructed and used for C3H10T1/2 cell transfection. Cell morphology was observed. Cardiac-related genes and proteins were detected by qPCR and western blot analysis. Epigallocatechin gallate (EGCG) was used as an inhibitor of acetylated histone H3 (AcH3). AcH3 was detected by chromatin immunoprecipitation. Cells overexpressing Islet-1 tended to change into fibroblast-like cells and were arranged in the same direction. The enhanced expression of GATA binding protein 4 (Gata4), NK2 homeobox 5 (Nkx2.5), myocyte enhancer factor 2C (Mef2c) and cardiac troponin T (cTnT) was observed in the cells overexpressing Islet-1 following transfection with Lenti-Islet-1. However, the expression of hepatocyte-, bone- and neuronal-specific markers was not affected by Islet-1. The AcH3 relative amount increased following transfection with Lenti-Islet-1, which was associated with the enhanced expression of Gata4, Nkx2.5 and Mef2c in these cells. The expression of Gata4, Nkx2.5 and Mef2c in the C3H10T1/2 cells transfected with Lenti-Islet-1 and treated with EGCG was reduced following treatment with EGCG. The data presented in this study indicate that Islet-1 specifically induces the differentiation of C3H10T1/2 cells into cardiomyocyte-like cells, and one of the mechanisms involved is the regulation of histone acetylation.
    International Journal of Molecular Medicine 03/2014; 33(5). DOI:10.3892/ijmm.2014.1687 · 1.88 Impact Factor
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    ABSTRACT: Bacground: The occurrence of Congenital Heart Disease (CHD) is resulted from either genetic or environmental factors or the both. The CITED2 gene deletion or mutation is associated with the development of cardiac malformations. In this study, we have investigated the role of CITED2 gene mutation and methylation in the development of Congenital Heart Disease in pediatric patients in China. We have screened 120 pediatric patients with congenital heart disease. Among these patients, 4 cases were detected to carry various CITED2 gene heterozygous mutations (c.550G > A, c.574A > G, c.573-578del6) leading correspondingly to the alterations of amino acid sequences in Gly184Ser, Ser192Gly, and Ser192fs, respectively. No CITED2 gene mutations were detected in the control group. At the same time, we found that CITED2 mutations could inhibit TFAP2c expression. In addition, we have demonstrated that abnormal CITED2 gene methylation was detected in most of the tested pediatric patients with CHD, which leads to a decrease of CITED2 transcription activities. Our study suggests that CITED2 gene mutations and methylation may play an important role in the development of pediatric congenital heart disease.
    Journal of Biomedical Science 01/2014; 21(1):7. DOI:10.1186/1423-0127-21-7 · 2.74 Impact Factor
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    ABSTRACT: Histone acetylation plays an important role in heart development. However, the mechanism(s) remains unclear. This study was designed to evaluate the effect of curcumin-caused histone hypo-acetylation on the development of mouse embryonic heart and the expression of cardiac transcription factors in vivo. The results showed that curcumin treatment significantly decreased histone acetylase activity and histone acetylation level in mouse embryonic heart. In curcumin-treated mice, the hearts on E11.5 were smaller with thinner ventricular wall and a delayed development of trabeculae and ventricular septum compared with the controls. The ventricular septum was complete on E14.5; however, the ventricular wall and septum were thinner with fewer trabeculae than those in the controls. On E17.5, the cardiac structure appeared normal, but the ventricular wall and septum were thinner. The expression of GATA4, Nkx2.5 and Mef2c in the heart on E11.5 and E14.5 was decreased significantly as compared to the controls. There was no significant difference in Mef2c expression on E17.5 between curcumin-treated group and the controls, while GATA4 and Nkx2.5 expression remained significantly reduced. These results indicate that inhibition of histone acetylation by curcumin can reduce the expression of the cardiac transcription factors resulting in an abnormal heart development in mice.
    Cardiovascular toxicology 12/2013; DOI:10.1007/s12012-013-9240-0 · 2.06 Impact Factor
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    ABSTRACT: Islet-1 is an important transcription factor for cardiac development through mediating extensive interactions between DNA and proteins. The present study was to investigate the role of Islet-1 in regulating the expression of cardiac development-related transcription factors and mechanism. The expression of Islet-1 and histone acetylases (HATs) subtype p300 was determined in newborn mouse hearts and mouse embryonic hearts at different development stages using Western blot. The expression of Islet-1 and cardiac development-related transcription factors Mef2c, GATA4 and Tbx5 as well as histone H3 acetylation level were determined in cardiac progenitor cells with and without transfection of Islet-1 interference RNA (RNAi) in lentivirus using PCR and Western blot. Islet-1 peak expression occurred on day E14.5 in mouse embryonic heart, and was present in the promoter regions of Mef2c, GATA4 and Tbx5 that were precipitated with p300 antibody. When Islet-1 was inhibited with specific RNAi in cardiac progenitor cells, the expression of Mef2c and Tbx5, but not GATA4, was significantly suppressed along with selective reduction in histone H3 acetylation in the promoter region of Mef2c, but not GATA4 and Tbx5. The level of Mef2c DNA, not GATA4 and Tbx5, in the complex associated with p300 was significantly decreased in the cells with Islet-1 knockdown. These data suggested that Islet-1 might function as an assistant factor that was involved in the regulation of histone acetylation and Mef2c expression via assisting p300 on specifically targeting the promoter of Mef2c.
    PLoS ONE 10/2013; 8(10):e77690. DOI:10.1371/journal.pone.0077690 · 3.53 Impact Factor
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    ABSTRACT: To explore the dose-dependent diastolic dysfunction and the mechanisms of heart failure and early death in transgenic (TG) mice modeling human restrictive cardiomyopathy (RCM). The first RCM mouse model (cTnI(193His) mice) carrying cardiac troponin I (cTnI) R193H mutation (mouse cTnI R193H equals to human cTnI R192H) was generated several years ago in our laboratory. The RCM mice manifested a phenotype similar to that observed in RCM patients carrying the same cTnI mutation, i.e. enlarged atria and restricted ventricles. However, the causes of heart failure and early death observed in RCM mice remain unclear. In this study, we have produced RCM TG mice (cTnI(193His)-L, cTnI(193His)-M and cTnI(193His)-H) that express various levels of mutant cTnI in the heart. Histological examination and echocardiography were performed in these mice to monitor the time course of the disease development and heart failure. Our data demonstrate that cTnI mutation-caused diastolic dysfunction is dose-dependent. The key mechanism is myofibril hypersensitivity to Ca(2+) resulting in an impaired relaxation in the mutant cardiac myocytes. Prolonged relaxation time and delay of Ca(2+) decay observed in the mutant cardiac myocytes are correlated with the level of the mutant protein in the heart. Markedly enlarged atria due to the elevated end-diastolic pressure and myocardial ischemia are observed in the heart of the transgenic mice. In the mice with the highest level of the mutant protein, restricted ventricles and systolic dysfunction occurs followed immediately by heart failure and early death. Diastolic dysfunction caused by R193H troponin I mutation is specific, showing a dose-dependent pattern. These mouse models are useful tools for study of diastolic dysfunction. Impaired diastole can cause myocardial ischemia and fibrosis formation, resulting in the development of systolic dysfunction and heart failure with early death in the RCM mice with a high level of the mutant protein in the heart.
    Journal of Molecular and Cellular Cardiology 06/2013; DOI:10.1016/j.yjmcc.2013.06.007 · 5.22 Impact Factor
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    ABSTRACT: Objective: Progenitor cell-based cardiomyocyte regeneration holds great promise of repairing an injured heart. Although cardiomyogenic differentiation has been reported for a variety of progenitor cell types, the biological factors that regulate effective cardiomyogenesis remain largely undefined. Primary cardiomyogenic progenitors (CPs) have a limited life span in culture, hampering the CPs' in vitro and in vivo studies. The objective of this study is to investigate if primary CPs isolated from fetal mouse heart can be reversibly immortalized with SV40 large T and maintain long-term cell proliferation without compromising cardiomyogenic differentiation potential. Methods: Primary cardiomyocytes were isolated from mouse E15.5 fetal heart, and immortalized retrovirally with the expression of SV40 large T antigen flanked with loxP sites. Expression of cardiomyogenic markers were determined by quantitative RT-PCR and immunofluorescence staining. The immortalization phenotype was reversed by using an adenovirus-mediated expression of the Cre reconbinase. Cardiomyogenic differentiation induced by retinoids or dexamethasone was assessed by an α-myosin heavy chain (MyHC) promoter-driven reporter. Results: We demonstrate that the CPs derived from mouse E15.5 fetal heart can be efficiently immortalized by SV40 T antigen. The conditionally immortalized CPs (iCP15 clones) exhibit an increased proliferative activity and are able to maintain long-term proliferation, which can be reversed by Cre recombinase. The iCP15 cells express cardiomyogenic markers and retain differentiation potential as they can undergo terminal differentiate into cardiomyctes under appropriate differentiation conditions although the iCP15 clones represent a large repertoire of CPs at various differentiation stages. The removal of SV40 large T increases the iCPs' differentiation potential. Thus, the iCPs not only maintain long-term cell proliferative activity but also retain cardiomyogenic differentiation potential. Conclusions: Our results suggest that the reported reversible SV40 T antigen-mediated immortalization represents an efficient approach for establishing long-term culture of primary cardiomyogenic progenitors for basic and translational research.
    International journal of medical sciences 06/2013; 10(8):1035-1046. DOI:10.7150/ijms.6639 · 1.55 Impact Factor
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    ABSTRACT: Chemotherapy is an important option for the treatment of advanced breast cancer, but multidrug resistance is one of the major obstacles in the clinical control of breast cancer. The present study investigated the effects of the miR‑195-led gene pathway in the sensitization of breast cancer cells to treatment with the chemotherapeutic drug Adriamycin. Breast cancer cell lines and tissue specimens (obtained from chemotherapy-sensitive or resistant patients) as well as a normal breast cell line were used to assess expression of miR-195, Raf-1, Bcl-2 and P-glycoprotein mRNA and/or mRNA. miR-195 mimics, inhibitor and Raf-1 siRNA were used to transfect breast cancer MCF-7 and MCF-7/ADR cells (an Adriamycin-resistant MCF-7 subline) for cell viability, apoptosis and gene expression analysis. The data showed that miR-195 expression was low in breast cancer cells and multidrug-resistant breast cancer tissues, which was associated with reduced Raf-1 expression in vitro and ex vivo. Induction of miR-195 expression promoted tumor cell apoptosis and inhibited breast cancer cell viability, but induced the sensitivity of breast cancer cells to Adriamycin treatment and was associated with inhibition of Raf-1 expression in breast cancer cells. Moreover, knockdown of Raf-1 expression had similar effects of miR-195 mimics on breast cancer cells, both of which were able to suppress Bcl-2 and P-glycoprotein expression in breast cancer cells. The data from the current study demonstrated that expression of miR-195 was inversely associated with Raf-1 expression in breast cancer cell lines and tissue specimens, and that Raf-1 is the target gene of miR-195. Thus, expression of miR-195 or knockdown of Raf-1 can similarly reduce tumor cell survival but increase apoptosis through downregulation of Raf-1 and Bcl-2 and P-glycoprotein expression. In conclusion, this gene pathway mediated the sensitivity of breast cancer cells to Adriamycin treatment.
    Oncology Reports 06/2013; 30(2). DOI:10.3892/or.2013.2532 · 2.19 Impact Factor
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    ABSTRACT: Histone acetylase (HAT) p300 plays an important role in the regulation of cardiac gene expression. During cardiac development, bone morphogenetic protein (BMP)-2 induces the expression of cardiac transcription factors. However, the underlying molecular mechanism(s) is not clear. In the present study, we tested the hypothesis that p300-mediated histone acetylation was essential for the regulation of cardiac transcription factors by BMP2. Cultured rat H9c2 embryonic cardiac myocytes (H9c2 cells) were transfected with recombinant adenoviruses expressing human BMP2 (AdBMP2) with or without curcumin, a specific p300-HAT inhibitor. Quantitative real-time RT-PCR analysis showed that curcumin substantially inhibited both AdBMP2-induced and basal expression levels of cardiac transcription factors GATA4 and MEF2C, but not Tbx5. Similarly, chromatin immunoprecipitation (ChIP) analysis showed that curcumin inhibited both AdBMP2-induced and basal histone H3 acetylation levels in the promoter regions of GATA4 and MEF2C, but not of Tbx5. In addition, curcumin selectively suppressed AdBMP2-induced expression of HAT p300, but not HAT GCN5 in H9c2 cells. The data indicated that inhibition of histone H3 acetylation with curcumin diminished BMP2-induced expression of GATA4 and MEF2C, suggesting that p300-mediated histone acetylation was essential for the regulation of GATA4 and MEF2C by BMP2 in H9c2 cells.
    Cardiovascular toxicology 04/2013; DOI:10.1007/s12012-013-9212-4 · 2.06 Impact Factor
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    ABSTRACT: Bone morphogenetic protein (BMP)‑2 induces the expression of cardiac transcription factors during early heart development, however, the underlying mechanisms for this are not clear. Our previous studies indicated that histone acetylation is critical in the regulation of cardiac gene expression. In the present study, the hypothesis that BMP2 enhances the expression of cardiac transcription factors by increasing histone H3 acetylation was tested. Cultured H9c2 rat embryonic cardiac myocytes were transfected with adenoviruses expressing human BMP2 (AdBMP2). Real‑time RT‑PCR, western blotting, chromatin immunoprecipitation (ChIP) and colorimetric assays were employed to determine gene expression, histone H3 acetylation levels and histone acetylase (HAT) activities. The mRNA expression levels of BMP2, GATA4, MEF2C and p300, but not of Tbx5 and GCN5, were significantly upregulated following transfection with AdBMP2. Similarly, the histone H3 acetylation levels were enhanced in the whole chromatin and in the promoter regions of GATA4 and MEF2C, but not Tbx5, in the transfected cells. The HAT activities were also enhanced. These results indicate that BMP2 is able to upregulate the expression of the cardiac transcription factors GATA4 and MEF2C, in part by increasing histone H3 acetylation in the promoter regions of these genes.
    Molecular Medicine Reports 01/2013; 7(3). DOI:10.3892/mmr.2013.1266 · 1.48 Impact Factor
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    ABSTRACT: Taurine has been shown to have potent anti-oxidant properties under various pathophysiological conditions. We reported previously a cellular dysfunction and mitochondrial damage in cardiac myocytes of methionine sulfoxide reductase A (MsrA) gene knockout mice (MsrA(-/-) ). In the present study, we have explored the protective effects of taurine against oxidative stress in the heart of MsrA(-/-) mice with or without taurine treatment. Cardiac cell contractility and Ca(2+) dynamics were measured using cell-based assays and in vivo cardiac function was monitored using high-resolution echocardiography in the tested animals. Our data have shown that MsrA(-/-) mice exhibited a progressive cardiac dysfunction with a significant decrease of ejection fraction (EF) and fraction shortening (FS) at age of 8 months compared to the wild type controls at the same age. However, the dysfunction was corrected in MsrA(-/-) mice treated with taurine supplement in the diet for 5 months. We further investigated the cellular mechanism underlying the protective effect of taurine in the heart. Our data indicated that cardiac myocytes from MsrA(-/-) mice treated with taurine exhibited an improved cell contraction and could tolerate oxidative stress better. Furthermore, taurine treatment reduced significantly the protein oxidation levels in mitochondria of MsrA(-/-) hearts, suggesting an anti-oxidant effect of taurine in cardiac mitochondria. Our study demonstrates that long-term treatment of taurine as a diet supplement is beneficial to a heart that is vulnerable to environmental oxidative stresses. J. Cell. Biochem. 113: 3559-3566, 2012. © 2012 Wiley Periodicals, Inc.
    Journal of Cellular Biochemistry 11/2012; 113(11):3559-66. DOI:10.1002/jcb.24233 · 3.37 Impact Factor