[Show abstract][Hide abstract] ABSTRACT: Background:
It is well known that epigenetic modifications play an important role in controlling the regulation of gene expression during the development. Our previous studies have demonstrated that the expression of fetal troponin I gene (also called slow skeletal troponin I, ssTnI) is predominated in the fetal stage, reduced after birth and disappeared in the adulthood. The mechanism underlying the developmentally related ssTnI gene regulation is not clear. In this study, we have explored the epigenetic role of DNA methylation in the regulation of ssTnI expression in the heart during the development.
The DNA methylation levels of CpG island and CpG dinucleotides region were detected using methylation specific PCR (MSP) and bisulfite sequence PCR (BSP) in 2000 bp upstream and 100 bp upstream of ssTnI gene promoter. Real time RT-PCR and Western blot were used to detect ssTnI mRNA and protein expression levels. We found that DNA methylation levels of the CpG dinucleotides region in ssTnI gene promoter were increased with the development, corresponding to a decreased expression of ssTnI gene in mouse heart. However the DNA methylation levels of CpG islands in this gene were not changed during the development. Application of a methylation inhibitor, 5-Azacytidine, in cultured myocardial cells partially prevented the decline of ssTnI expression.
Our results indicate that DNA methylation, as an epigenetic intervention, plays a role in the regulation of the fetal TnI gene expression in the heat during the development.
Preview · Article · Oct 2015 · Journal of Biomedical Science
[Show abstract][Hide abstract] ABSTRACT: Alcohol abuse during pregnancy may cause fetal cardiac developmental abnormalities. Our previous studies showed that alcohol could induce histone hyperacetylation and over-expression of cardiac transcription factors both in vivo and in vitro. The objective of the present study was to investigate the role of ERK1/2 signaling pathway in alcohol-induced histone hyperacetylation and up-regulation of cardiac transcription factors in H9c2 cells. The Cardiac cell line H9c2 was cultured with alcohol. U0126, a specific inhibitor of ERK1/2 pathway was employed to block the ERK1/2 signaling pathway. Western blotting analysis showed that alcohol significantly enhanced the levels of phosphorylated ERK1/2 and induced hyperacetylation of histone3, which were both effectively prevented with U0126. Real-time PCR showed that U0126 treatment significantly decreased alcohol-induced over-expression of GATA4 and MEF2c, and the basal expression level of GATA4, but did not affect MEF2c. ChIP assay showed that U0126 treatment significantly decreased alcohol-induced hyperacetylation of histone3 near the promoter regions of GATA4 and MEF2c. The basal acetylation level of histone3 near the promoter region of GATA4 was affected by U0126 as well, but not that near the promoter region of MEF2c. These data indicated that ERK1/2 signaling played an important role in mediating alcohol induced over-expression of GATA4 and MEF2c, which is possibly through the up-regulation of acetylation of histone3 near the gene promoters that affects the expression of GATA4 and MEF2c in H9c2 cells. ERK1/2 pathway might be a potential target for the intervention of alcohol induced congenital heart diseases.
No preview · Article · Sep 2015 · Biochemical and Biophysical Research Communications
[Show abstract][Hide abstract] ABSTRACT: MicroRNAs (miRNAs) are small non-coding RNAs, which are important in the development of multidrug resistance in cancer by regulating gene expression at the post‑transcriptional level. The present study investigated the functional effects of miR‑522 in chemoresistant colon cancer cells. The results demonstrated that miR‑522 was significantly downregulated in doxorubicin (DOX) resistant colon cell line, HT29/DOX, compared with the parental HT29 colon cancer cell line. Overexpression of miR‑522 in the HT29/DOX cells partially restored DOX sensitivity. miRNA target prediction algorithms suggested that ABCB5 was a target gene for miR‑522. A fluorescent reporter assay confirmed that miR‑522 was able to specifically bind to the predicted site of the ABCB5 mRNA 3'‑untranslated region. When miR‑522 was overexpressed in the HT29/DOX cells, the protein expression levels of ABCB5 were downregulated. Furthermore, knockdown of ABCB5 significantly increased the growth inhibition rate of the HT29/DOX cells, compared with the control group. These results suggested that miR‑522 may affect the sensitivity of colon cancer cell lines to DOX treatment by targeting ABCB5.
No preview · Article · Jun 2015 · Molecular Medicine Reports
[Show abstract][Hide abstract] 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.
No preview · Article · Oct 2014 · Cardiovascular Toxicology
[Show abstract][Hide abstract] 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.
No preview · Article · Sep 2014 · Alcoholism Clinical and Experimental Research
[Show abstract][Hide abstract] 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.
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.
[Show abstract][Hide abstract] 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.
No preview · Article · Aug 2014 · Toxicology Letters
[Show abstract][Hide abstract] 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.
Preview · Article · May 2014 · Biochemical and Biophysical Research Communications
[Show abstract][Hide abstract] 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.
No preview · Article · Apr 2014 · Zhongguo dang dai er ke za zhi = Chinese journal of contemporary pediatrics
[Show abstract][Hide abstract] ABSTRACT: Objective:
We have evaluated 106 pediatric cases of infective endocarditis (IE) to elucidate clinical manifestations and pathogenic microorganism profiling of IE in China.
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).
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.
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.
[Show abstract][Hide abstract] 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.
Preview · Article · Mar 2014 · International Journal of Molecular Medicine
[Show abstract][Hide abstract] 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.
Preview · Article · Jan 2014 · Journal of Biomedical Science
[Show abstract][Hide abstract] 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.
No preview · Article · Dec 2013 · Cardiovascular toxicology
[Show abstract][Hide abstract] ABSTRACT: Mesenchymal stem cells (MSCs) have the potential to be the source for cell-based therapies. However, MSCs can go malignant transformation in tumor microenvironment where a high level of IL-6 is present. In this study, we have investigated the role of IL-6 and STAT3 signaling in malignant transformation of MSCs. Rat MSCs were isolated and indirectly co-cultured with C6 glioma cells. Co-culture of MSCs with astrocytes was used as a control. After 7 days of culture, the cells were assessed for malignant transformation using MTT, immunofluorescence staining. The levels of hepatocyte growth factor (HGF), interleukin-6 (IL-6) and basic fibroblast growth factor (BFGF), and the expression of STAT3 and soluble IL-6 receptor (sIL-6R) in the cultured cells and the conditioned media were measured using RT-PCR, ELISA, and Western blotting. The expression levels of STAT3 downstream targets, CyclinD1 and Bcl-xl, were determined as well. Our data have shown that almost all of the MSCs became phenotypically malignant after indirect co-culture with glioma cells, which was confirmed by tumor formation assays when these cells were injected into nude mice. The expression of IL-6 was significantly increased in the MSCs co-cultured with glioma cells, which was associated with significantly increased expressions of sIL-6R, GP130, STAT3, phosphorylated STAT3, CyclinD1, and Bcl-xl. Similar results were obtained when the MSCs were treated with IL-6. And treating the co-cultured MSCs with glioma by STA-21 to block the constitutive STAT3 signaling, the risk of MSCs tumor-like transformation in tumor microenvironment were reduced. These data suggest that IL-6 plays a critical role in malignant transformation of rat MSCs which is associated with an enhancement of STAT3 signaling pathway in tumor microenvironment. This article is protected by copyright. All rights reserved.
[Show abstract][Hide abstract] 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.
[Show abstract][Hide abstract] 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.
Full-text · Article · Jun 2013 · Journal of Molecular and Cellular Cardiology