The recent identification of cardiac progenitor cells （CPCs） provides a new paradigm for studying and treating heart disease. To realize the full potential of CPCs for therapeutic purposes, it is essential to unders...The recent identification of cardiac progenitor cells （CPCs） provides a new paradigm for studying and treating heart disease. To realize the full potential of CPCs for therapeutic purposes, it is essential to understand the genetic and epigenetic mechanisms guiding CPC differentiation into cardiomyocytes, smooth muscle, or endothelial cells. ATP-dependent chromatin remodelers mediate one critical epigenetic mechanism. These large multiprotein complexes open up chromatin to modulate transcription factor access to DNA. SWI/SNF, one of the major types of chromatin remodelers, plays a key role in various aspects of development （de la Serna et al., 2006; Wu et al., 2009）, including heart development and disease （Lickert et al., 2004; Wang et al., 2004; Huang et al., 2008; Stankunas et al., 2008; Hang et al., 2010）. In this review, we describe the specific function of various SWI/SNF components in cardiogenesis and cardiac progenitor cell （CPC） self-renewal and differentiation. We envision that a detailed understanding of the SWI/SNF in heart development and CPC formation and differentiation will generate novel insights into epigenetic mechanisms that govern CPC differentiation and may have significant implications in understanding and treating heart disease.展开更多
Backgroud Recent studies in adult hearts have indicated that K ATP channels in the inner mitochondrial membrance are responsible for the protection. And we investigated whether opening of mitochondrial K ATP ...Backgroud Recent studies in adult hearts have indicated that K ATP channels in the inner mitochondrial membrance are responsible for the protection. And we investigated whether opening of mitochondrial K ATP channels (mK ATP ) could provide myocardial protection for immature rabbits and determined its role in cardioprotection Methods Thirty-four 3-4-week-old rabbits, weighing 300-350 g, were divided randomly into five groups: Group Ⅰ (control group, n=8); Group Ⅱ [diazoxide preconditioning group; n=8; the hearts were pretreated with 100 μmol/L diazoxide for 5 minutes followed by 10-minute wash out with Krebs-Henseleit buffer (KHB)]; Group Ⅲ ; Group Ⅲ [diazoxide+5-hydroxydeconate (5-HD) preconditioning group; n=5; the hearts were pretreated with 100 μmol/L diazoxide and 100 μmol/L 5-HD); Group Ⅳ (diazoxide+cardioplegia group; n=8; cardioplegia containing 100 μmol/L diazoxide perfused the hearts for 5 minutes before ischemia); Group Ⅴ (diazoxide+5-HD+cardioplegia group; n=5; the cardioplegia contained 100 μmol/L diazoxide and 100 μmol/L 5-HD) All hearts were excised and connected to langendrff perfusion system and passively perfused with KHB at 38℃ under a pressure of 70 cmH 2O After reperfusion, the recovery rate of left ventricular diastolic pressure (LVDP), ±dp/dt max , coronary flow (CF), the creatinine kinase (CK), lactate dehydrogenase (LDH), aspartate aminotransferase (AST) in coronary sinus venous effluent and the tissue ATP were measured Mitochondria were evaluated semiquantitatively by morphology Results After ischemia and reperfusion (I/R), the two groups that were treated by diazoxide only (Groups Ⅱ and Ⅳ) had a significant improvement in LVDP, ±dp/dt max , and CF recovery AST, LDH, and CK were decreased, and the levels of tissue ATP in the two groups were higher Mitochondria was protected better in Group Ⅳ than in other groups Conclusions Activating mK ATP channels before and during ischemia can similarly protect immature rabbit hearts, and the mechanism is related to the direct protective effect on mitochondria Opening of mK ATP channel during ischemia provides a better protection for mitochondria than it does before ischemia展开更多
文摘The recent identification of cardiac progenitor cells （CPCs） provides a new paradigm for studying and treating heart disease. To realize the full potential of CPCs for therapeutic purposes, it is essential to understand the genetic and epigenetic mechanisms guiding CPC differentiation into cardiomyocytes, smooth muscle, or endothelial cells. ATP-dependent chromatin remodelers mediate one critical epigenetic mechanism. These large multiprotein complexes open up chromatin to modulate transcription factor access to DNA. SWI/SNF, one of the major types of chromatin remodelers, plays a key role in various aspects of development （de la Serna et al., 2006; Wu et al., 2009）, including heart development and disease （Lickert et al., 2004; Wang et al., 2004; Huang et al., 2008; Stankunas et al., 2008; Hang et al., 2010）. In this review, we describe the specific function of various SWI/SNF components in cardiogenesis and cardiac progenitor cell （CPC） self-renewal and differentiation. We envision that a detailed understanding of the SWI/SNF in heart development and CPC formation and differentiation will generate novel insights into epigenetic mechanisms that govern CPC differentiation and may have significant implications in understanding and treating heart disease.
文摘Backgroud Recent studies in adult hearts have indicated that K ATP channels in the inner mitochondrial membrance are responsible for the protection. And we investigated whether opening of mitochondrial K ATP channels (mK ATP ) could provide myocardial protection for immature rabbits and determined its role in cardioprotection Methods Thirty-four 3-4-week-old rabbits, weighing 300-350 g, were divided randomly into five groups: Group Ⅰ (control group, n=8); Group Ⅱ [diazoxide preconditioning group; n=8; the hearts were pretreated with 100 μmol/L diazoxide for 5 minutes followed by 10-minute wash out with Krebs-Henseleit buffer (KHB)]; Group Ⅲ ; Group Ⅲ [diazoxide+5-hydroxydeconate (5-HD) preconditioning group; n=5; the hearts were pretreated with 100 μmol/L diazoxide and 100 μmol/L 5-HD); Group Ⅳ (diazoxide+cardioplegia group; n=8; cardioplegia containing 100 μmol/L diazoxide perfused the hearts for 5 minutes before ischemia); Group Ⅴ (diazoxide+5-HD+cardioplegia group; n=5; the cardioplegia contained 100 μmol/L diazoxide and 100 μmol/L 5-HD) All hearts were excised and connected to langendrff perfusion system and passively perfused with KHB at 38℃ under a pressure of 70 cmH 2O After reperfusion, the recovery rate of left ventricular diastolic pressure (LVDP), ±dp/dt max , coronary flow (CF), the creatinine kinase (CK), lactate dehydrogenase (LDH), aspartate aminotransferase (AST) in coronary sinus venous effluent and the tissue ATP were measured Mitochondria were evaluated semiquantitatively by morphology Results After ischemia and reperfusion (I/R), the two groups that were treated by diazoxide only (Groups Ⅱ and Ⅳ) had a significant improvement in LVDP, ±dp/dt max , and CF recovery AST, LDH, and CK were decreased, and the levels of tissue ATP in the two groups were higher Mitochondria was protected better in Group Ⅳ than in other groups Conclusions Activating mK ATP channels before and during ischemia can similarly protect immature rabbit hearts, and the mechanism is related to the direct protective effect on mitochondria Opening of mK ATP channel during ischemia provides a better protection for mitochondria than it does before ischemia
