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Heart failure is a common, costly, and potentially fatal condition. The cardiac sarcoplasmic reticulum Ca-ATPase (SERCA2a) plays a critical role in the regulation of cardiac function. Previously, low SERCA2a expression was revealed in mice with heart failure. Epigallocatechin-3-gallate (EGCG) can function as an epigenetic regulator and has been reported to enhance cardiac function. However, the underlying epigenetic regulatory mechanism is still unclear. In this study, we investigated whether EGCG can up-regulate SERCA2a via histone acetylation and play role in preventing heart failure. For this, we generated a mouse model of heart failure by performing a minimally invasive transverse aortic constriction (TAC) operation and used this to test the effects of EGCG. The TAC+EGCG group showed nearly normal cardiac function compared to that in the SHAM group. The expression of SERCA2a was decreased at both the mRNA and protein levels in the TAC group but was enhanced in the TAC+EGCG group. Levels of AcH3 and AcH3K9 were determined to decrease near the promoter region of Atp2a2 (the gene encoding SERCA-2a) in the TAC group, but were elevated in the TAC+EGCG group. Meanwhile, HDAC1 activity and binding near the Atp2a2 promoter were increased in the TAC group but decreased with EGCG addition. Further, binding levels of GATA4 and Mef2c near the Atp2a2 promoter region were reduced in TAC hearts, which might have been caused by histone hypoacetylation; this was reversed by EGCG. Together, upregulation of SERCA2a via the modification of histone acetylation plays a role in EGCG-mediated prevention of pressure overload-induced heart failure, and this might represent a novel pharmacological target for the treatment of heart failure. [ABSTRACT FROM AUTHOR]

Cardiac diastolic dysfunction ( CDD) is the most common form of cardiovascular disorders, especially in elderly people. Cardiac troponin I ( cTnI) plays a critical role in the regulation of cardiac function, especially diastolic function. Our previous studies showed that cTnI-low expression induced by histone acetylation modification might be one of the causes that result in diastolic dysfunction in ageing hearts. This study was designed to investigate whether epigallocatechin-3-gallate ( EGCG) would modify histone acetylation events to regulate cTnI expression and then improve cardiac functions in ageing mice. Our study shows that EGCG improved cardiac diastolic function of aged mice after 8-week treatment. Low expression of cTnI in the ageing hearts was reversed through EGCG treatment. EGCG inhibited the expression of histone deacetylase 1 ( HDAC1) and HDAC3, and the binding levels of HDAC1 in the proximal promoter of cTnI. Acetylated lysine 9 on histone H3 (AcH3K9) levels of cTnI's promoter were increased through EGCG treatment. Additionally, EGCG resulted in an ascent of the binding levels of transcription factors GATA4 and Mef2c with cTnI's promoter. Together, our data indicate that EGCG may improve cardiac diastolic function of ageing mice through up-regulating cTnI by histone acetylation modification. These findings provide new insights into histone acetylation mechanisms of EGCG treatment that may contribute to the prevention of CDD in ageing populations. [ABSTRACT FROM AUTHOR]

Background: Our previous studies have demonstrated that Ca2+ desensitizing catechin could correct diastolic dysfunction in experimental animals with restrictive cardiomyopathy. In this study, it is aimed to assess the effects of green tea extract catechin on cardiac function and other clinical features in pediatric patients with cardiomyopathies. Methods: Twelve pediatric cardiomyopathy patients with diastolic dysfunction were enrolled for the study. Echocardiography, ECG, and laboratory tests were performed before and after the catechin administration for 12 months. Comparison has been made in these patients before and after the treatment with catechin. Next Generation Sequencing was conducted to find out the potential causative gene variants in all patients. Results: A significant decrease of isovolumetric relaxation time (115 ± 46 vs 100 ± 42 ms, P = 0.047 at 6 months; 115 ± 46 vs 94 ± 30 ms, P = 0.033 at 12 months), an increase of left ventricle end diastolic volume (40 ± 28 vs 53 ± 28 ml, P = 0.028 at 6 months; 40 ± 28 vs 48 ± 33 ml, P = 0.011 at 12 months) and stroke volume (25 ± 16 vs 32 ± 17 ml, P = 0.022 at 6 months; 25 ± 16 vs 30 ± 17 ml, P = 0.021 at 12 months) were observed with echocardiography in these patients 6-month after the treatment with catechin. Ejection fraction, left ventricular wall thickness, biatrial dimension remained unchanged. No significant side effects were observed in the patients tested. Conclusions: This study indicates that Ca2+ desensitizing green tea extract catechin, is helpful in correcting the impaired relaxation in pediatric cardiomyopathy patients with diastolic dysfunction. [ABSTRACT FROM AUTHOR]

To investigate the mechanisms of potential cardioprotective effects of epigallocatechin-3-gallate (EGCG) in pressure overload-induced cardiac dysfunction. A chronic heart failure model was established using abdominal aortic constriction (AAC) surgery, rats were divided into sham, AAC, and AAC + EGCG groups. Echocardiography and tissue section staining were performed to evaluate cardiac function and pathology, respectively. Gene expression level were detected with quantitative real-time polymerase chain reactions. Label-free quantitative proteomics was used to investigate the whole proteomes of heart, and the differentially expressed proteins were analyzed using bioinformatics methods. Western blot was performed to validate the levels and the reliability of the differential proteins. Compared with the AAC group, systolic dysfunction was improved in AAC + EGCG group after EGCG treatment. EGCG inhibited myocardial fibrosis and cardiac hypertrophy after AAC, along with reducing atrial natriuretic protein, B-type natriuretic peptide, collagen types 1 and 3 alpha 1, and transforming growth factor β-1. Quantitative proteomics identified a total of 162 differentially expressed proteins, among them, 18 were closely related to cardiovascular disorders. Bioinformatics analyses showed that EGCG played a therapeutic role mainly by changing energy metabolism processes, such as oxidative phosphorylation and lipid metabolism. Furthermore, NADH: ubiquinone oxidoreductase subunit S4, an important component of the mitochondrial respiratory chain, was increased after AAC and then reversed by EGCG, which was consistent with the proteomics results. EGCG may correct cardiac systolic dysfunction and prevent cardiac remodeling after heart failure via enhancing the energy metabolism, which provides us with new insights into cardioprotective effects of EGCG related to the energy metabolisms in pressure overload-induced cardiac dysfunction. • EGCG had a protective effect on pressure overload-induced cardiac dysfunction by affecting energy metabolism. • EGCG ameliorated myocardial hypertrophy and fibrosis caused by pressure overload. • Proteomics was used to explore the cardioprotective effects of EGCG. [ABSTRACT FROM AUTHOR]