The loss of cardiomyocytes during injury and disease can result in heart failure and sudden death, while the adult heart has a limited capacity for endogenous regeneration and repair. Current stem cell-based regenerat...The loss of cardiomyocytes during injury and disease can result in heart failure and sudden death, while the adult heart has a limited capacity for endogenous regeneration and repair. Current stem cell-based regenerative medicine approaches modestly improve cardiomyocyte survival, but offer neglectable cardiomyogenesis. This has prompted the need for methodological developments that crease de novo cardiomyocytes. Current insights in cardiac development on the processes and regulatory mechanisms in embryonic cardiomyocyte differentiation provide a basis to therapeutically induce these pathways to generate new cardiomyocytes. Here, we discuss the current knowledge on embryonic cardiomyocyte differentiation and the implementation of this knowledge in state-ofthe-art protocols to the direct reprogramming of cardiac fibroblasts into de novo cardiomyocytes in vitro and in vivo with an emphasis on micro RNA-mediated reprogramming. Additionally, we discuss current advances on state-of-theart targeted drug delivery systems that can be employed to deliver these micro RNAs to the damaged cardiac tissue. Together, the advances in our understanding of cardiac development, recent advances in micro RNAbased therapeutics, and innovative drug delivery systems, highlight exciting opportunities for effective therapies for myocardial infarction and heart failure.展开更多
Objective To investigate whether cardiac tissue extracts from rats could mimic the cardiac microenvironment and act as a natural inducer in promoting the differentiation of bone marrow stromal cells (BMSCs) into car...Objective To investigate whether cardiac tissue extracts from rats could mimic the cardiac microenvironment and act as a natural inducer in promoting the differentiation of bone marrow stromal cells (BMSCs) into cardiomyocytes. Methods Three kinds of tissue extract or cell lysate [infarcted myocardial tissue extract (IMTE), normal myocardial tissue extract (NMTE) and cultured neonatal myocardial lysate (NML)] were employed to induce BMSCs into cardiomyocyte-like cells. The cells were harvested at each time point for reverse transcription-polymerase chain reaction (RT-PCR) detection, immunocytochemical analysis, and transmission electron microscopy. Results After a 7-day induction, BMSCs were enlarged and polygonal in morphology. Myofilaments, striated sarcomeres, Z-lines, and more mitochondia were observed under transmission electron microscope. Elevated expression levels of cardiac-specific genes and proteins were also confirmed by RT-PCR and immunocytochemistry. Moreover, IMTE showed a greater capacity of differentiating BMSCs into cardiomyocyte-like cells. Conclusions Cardiac tissue extracts, especially IMTE, can effectively differentiate BMSCs into cardiomyocyte-like cells.展开更多
Background:To understand the relationship between myocardial contractility and ex-ternal stimuli,detecting ex vivo myocardial contractility is necessary.Methods:We elaborated a method for contractility detection of is...Background:To understand the relationship between myocardial contractility and ex-ternal stimuli,detecting ex vivo myocardial contractility is necessary.Methods:We elaborated a method for contractility detection of isolated C57 mouse papillary muscle using Myostation-Intact system under different frequencies,volt-ages,and calcium concentrations.Results:The results indicated that the basal contractility of the papillary muscle was 0.27±0.03 mN at 10 V,500-ms pulse duration,and 1 Hz.From 0.1 to 1.0 Hz,con-tractility decreased with an increase in frequency(0.45±0.11-0.10±0.02 mN).The voltage-initiated muscle contractility varied from 3 to 6 V,and the contractility gradu-ally increased as the voltage increased from 6 to 10 V(0.14±0.02-0.28±0.03 mN).Moreover,the muscle contractility increased when the calcium concentration was increased from 1.5 to 3 mM(0.45±0.17-1.11±0.05 mN);however,the contractility stopped increasing even when the concentration was increased to 7.5 mM(1.02±0.23 mN).Conclusions:Our method guaranteed the survivability of papillary muscle ex vivo and provided instructions for Myostation-Intact users for isolated muscle contractility investigations.展开更多
Background Few studies have evaluated late clinical outcome of no-patch technique in patients with large left ventricular aneurysms. The objectives of this study were to evaluate a no-patch surgical technique to recon...Background Few studies have evaluated late clinical outcome of no-patch technique in patients with large left ventricular aneurysms. The objectives of this study were to evaluate a no-patch surgical technique to reconstruct the left ventricle in patients with left ventricular aneurysm and to assess early and late clinical outcomes.Methods In 1995, we began using a no-patch technique in patients with dyskinetic left ventricular aneurysms. A total of 145 patients underwent left ventricular reconstruction with this technique and were followed up for (59±29) months (range,1-127 months). Risk factors for early mortality were analyzed by bivariate analyses. Cox's proportional hazards model was used to calculate risk factors for all-cause mortality and hospital readmission. Kaplan-Meier methodology was used to analyze late survival.Results One week after operation, left ventricular end-diastolic diameter had decreased from (61±8) mm to (55±8)mm, and geometry of the left ventricle was restored to a more normal conical shape. Early mortality was 3% and late mortality 11%. Over a 5-year follow-up period, hospital readmission was 28%. One-, 5-, and 10-year survival estimates were 95% (95% confidence interval (CI) 91%-99%), 86% (95% CI 78%-94%), and 74% (95% CI 60%-88%).Readmission-free survival at 1 and 5 years after operation was 87% (95% CI81%-93%) and 60% (95% CI50%-70%),respectively.Conclusion The no-patch technique for left ventricular reconstruction is an effective and simple procedure that can achieve satisfactory early and late clinical outcomes in patients with left ventricular aneurysms.展开更多
Background Bioprosthetic heart valves derived from glutaraldehyde (Glut)-fixed xenografts have been widely used to replace diseased cardiac valves. However, calcification and degeneration are common following their ...Background Bioprosthetic heart valves derived from glutaraldehyde (Glut)-fixed xenografts have been widely used to replace diseased cardiac valves. However, calcification and degeneration are common following their implantation. Inflammation is closely associated with calcification of Glut-fixed xenografts via macrophage infiltration. Tannic acid (TA) possesses anti-inflammatory effects. This study was designed to investigate the anti-calcification of TA treatment on the Glut-fixed bovine pericardium (BP) in a rat subdermal model. Methods Fresh BP was divided into two groups (10 in each group) and separately subjected to different fixation procedures as follows: (1) Glut group: fixation with 0.6% Glut alone; (2) Glut/TA group: fixation with 0.6% Glut and subsequent 0.3% TA. Then the BP samples were subdermally implanted in juvenile male Sprague-Dawley rats and explanted 21 days after implantation. Each explanted BP sample was divided into three parts for calcium content analysis von Kossa's staining and immunohistochemical staining, and reverse transcription-polymerase chain reaction study. Results The data from quantitative calcium analysis and von Kossa's staining showed that Glut-fixed BP developed significantly more calcification than Glut/TA-fixed BP ((90.3+32.5) mg/g dry weight vs (6.4_+1.3) mg/g dry tissue, P 〈0.01). Immunostaining demonstrated lower matrix metalloproteinase-9 and tenascin-C expression as well as macrophage infiltration into Glut/TA-fixed BP than in its Glut-fixed counterpart (P 〈0.01 for all). Additionally, the reverse transcription-polymerase chain reaction study showed that higher levels of expression of matrix metalloproteinase-9 and tenascin-C mRNA occurred within Glut-fixed BP than within the Glut/TA-fixed ones (P 〈0.01 for all). Conclusion TA exerts excellent anti-calcification effects on Glut-fixed BP via inhibiting macrophage infiltration and expression of matrix metalloproteinase-9 and tenascin-C.展开更多
Background The European System for Cardiac Operative Risk Evaluation (EuroSCORE) is one of the most widely used risk models for the predicting mortality after cardiac surgery. The aim of this study was to validate t...Background The European System for Cardiac Operative Risk Evaluation (EuroSCORE) is one of the most widely used risk models for the predicting mortality after cardiac surgery. The aim of this study was to validate the EuroSCORE model for predicting operative mortality in heart valve surgery on a Chinese multicenter database and comparing the performance of EuroSCORE with our new risk stratification system, the Sino System for Coronary Operative Risk Evaluation (SinoSCORE). Methods Data from patients undergoing heart valve surgery between January 2007 and December 2008 were retrospectively collected, from 43 hospitals in China. The EuroSCORE and the SinoSCORE were calculated for each patient. Mortality was defined as any in-hospital death. Area under the receiver operating characteristics curve (AUC) was used to study the discriminatory abilities of the models. The Hosmer-Lemeshow (H-L) goodness-of-fit test was used to study the calibration of the predictive models. Results A total of 15 367 patients were analyzed. For the entire cohort, the observed mortality was 2.34%, the predicted mortality was 3.71% (additive), 3.19% (logistic) and 3.66% (SinoSCORE). AUC was 0.747 for SinoSCORE, 0.699 additive and 0.696 for logistic EuroSCORE. Calibration of SinoSCORE and additive EuroSCORE was good (H-L: P=-0.250 and P=0.051, respectively), but the logistic EuroSCORE model had a poor calibration (H-L: P〈0.05). The discriminatory ability and calibration of the SinoSCORE were good in low- and high-risk patients, However, the discriminatory ability of the EuroSCORE model was poor in all risk deciles. Conclusions The EuroSCORE does not accurately predict mortality in Chinese patients with heart valve surgery, and the SinoSCORE is superior to the EuroSCORE at predicting in-hospital mortality in Chinese heart valve surgery patients.展开更多
The RNA editing tool CRISPR-CasRx has provided a platform for a range of transcriptome analysis tools and therapeutic approaches with its broad efficacy and high specificity.To enable the application of CasRx in vivo,...The RNA editing tool CRISPR-CasRx has provided a platform for a range of transcriptome analysis tools and therapeutic approaches with its broad efficacy and high specificity.To enable the application of CasRx in vivo,we established a Credependent CasRx knock-in mouse.Using these mice,we specifically knocked down the expression of Meis1 and Hoxb13 in cardiomyocytes,which induced cardiac regeneration after myocardial infarction.We also knocked down the lnc RNA Mhrt in cardiomyocytes with the CasRx knock-in mice,causing hypertrophic cardiomyopathy.In summary,we generated a Credependent CasRx knock-in mouse that can efficiently knock down coding gene and lnc RNA expression in specific somatic cells.This in vivo CRISPR-CasRx system is promising for gene function research and disease modeling.展开更多
文摘The loss of cardiomyocytes during injury and disease can result in heart failure and sudden death, while the adult heart has a limited capacity for endogenous regeneration and repair. Current stem cell-based regenerative medicine approaches modestly improve cardiomyocyte survival, but offer neglectable cardiomyogenesis. This has prompted the need for methodological developments that crease de novo cardiomyocytes. Current insights in cardiac development on the processes and regulatory mechanisms in embryonic cardiomyocyte differentiation provide a basis to therapeutically induce these pathways to generate new cardiomyocytes. Here, we discuss the current knowledge on embryonic cardiomyocyte differentiation and the implementation of this knowledge in state-ofthe-art protocols to the direct reprogramming of cardiac fibroblasts into de novo cardiomyocytes in vitro and in vivo with an emphasis on micro RNA-mediated reprogramming. Additionally, we discuss current advances on state-of-theart targeted drug delivery systems that can be employed to deliver these micro RNAs to the damaged cardiac tissue. Together, the advances in our understanding of cardiac development, recent advances in micro RNAbased therapeutics, and innovative drug delivery systems, highlight exciting opportunities for effective therapies for myocardial infarction and heart failure.
基金This work was supported by the National Natural Science Foundation of China (No. 30570722)
文摘Objective To investigate whether cardiac tissue extracts from rats could mimic the cardiac microenvironment and act as a natural inducer in promoting the differentiation of bone marrow stromal cells (BMSCs) into cardiomyocytes. Methods Three kinds of tissue extract or cell lysate [infarcted myocardial tissue extract (IMTE), normal myocardial tissue extract (NMTE) and cultured neonatal myocardial lysate (NML)] were employed to induce BMSCs into cardiomyocyte-like cells. The cells were harvested at each time point for reverse transcription-polymerase chain reaction (RT-PCR) detection, immunocytochemical analysis, and transmission electron microscopy. Results After a 7-day induction, BMSCs were enlarged and polygonal in morphology. Myofilaments, striated sarcomeres, Z-lines, and more mitochondia were observed under transmission electron microscope. Elevated expression levels of cardiac-specific genes and proteins were also confirmed by RT-PCR and immunocytochemistry. Moreover, IMTE showed a greater capacity of differentiating BMSCs into cardiomyocyte-like cells. Conclusions Cardiac tissue extracts, especially IMTE, can effectively differentiate BMSCs into cardiomyocyte-like cells.
基金Specialized Project of Fuwai Hospital,Grant/Award Number:2022-FWTS07Shenzhen Sanming Project of Medicine,Grant/Award Number:2016-SZZF02+1 种基金National Natural Science Foundation of China,Grant/Award Number:81900343CAMS Innovation Fund for Medical Sciences,Grant/Award Number:CIFMS,2021-I2M-C&T-A-011。
文摘Background:To understand the relationship between myocardial contractility and ex-ternal stimuli,detecting ex vivo myocardial contractility is necessary.Methods:We elaborated a method for contractility detection of isolated C57 mouse papillary muscle using Myostation-Intact system under different frequencies,volt-ages,and calcium concentrations.Results:The results indicated that the basal contractility of the papillary muscle was 0.27±0.03 mN at 10 V,500-ms pulse duration,and 1 Hz.From 0.1 to 1.0 Hz,con-tractility decreased with an increase in frequency(0.45±0.11-0.10±0.02 mN).The voltage-initiated muscle contractility varied from 3 to 6 V,and the contractility gradu-ally increased as the voltage increased from 6 to 10 V(0.14±0.02-0.28±0.03 mN).Moreover,the muscle contractility increased when the calcium concentration was increased from 1.5 to 3 mM(0.45±0.17-1.11±0.05 mN);however,the contractility stopped increasing even when the concentration was increased to 7.5 mM(1.02±0.23 mN).Conclusions:Our method guaranteed the survivability of papillary muscle ex vivo and provided instructions for Myostation-Intact users for isolated muscle contractility investigations.
文摘Background Few studies have evaluated late clinical outcome of no-patch technique in patients with large left ventricular aneurysms. The objectives of this study were to evaluate a no-patch surgical technique to reconstruct the left ventricle in patients with left ventricular aneurysm and to assess early and late clinical outcomes.Methods In 1995, we began using a no-patch technique in patients with dyskinetic left ventricular aneurysms. A total of 145 patients underwent left ventricular reconstruction with this technique and were followed up for (59±29) months (range,1-127 months). Risk factors for early mortality were analyzed by bivariate analyses. Cox's proportional hazards model was used to calculate risk factors for all-cause mortality and hospital readmission. Kaplan-Meier methodology was used to analyze late survival.Results One week after operation, left ventricular end-diastolic diameter had decreased from (61±8) mm to (55±8)mm, and geometry of the left ventricle was restored to a more normal conical shape. Early mortality was 3% and late mortality 11%. Over a 5-year follow-up period, hospital readmission was 28%. One-, 5-, and 10-year survival estimates were 95% (95% confidence interval (CI) 91%-99%), 86% (95% CI 78%-94%), and 74% (95% CI 60%-88%).Readmission-free survival at 1 and 5 years after operation was 87% (95% CI81%-93%) and 60% (95% CI50%-70%),respectively.Conclusion The no-patch technique for left ventricular reconstruction is an effective and simple procedure that can achieve satisfactory early and late clinical outcomes in patients with left ventricular aneurysms.
文摘Background Bioprosthetic heart valves derived from glutaraldehyde (Glut)-fixed xenografts have been widely used to replace diseased cardiac valves. However, calcification and degeneration are common following their implantation. Inflammation is closely associated with calcification of Glut-fixed xenografts via macrophage infiltration. Tannic acid (TA) possesses anti-inflammatory effects. This study was designed to investigate the anti-calcification of TA treatment on the Glut-fixed bovine pericardium (BP) in a rat subdermal model. Methods Fresh BP was divided into two groups (10 in each group) and separately subjected to different fixation procedures as follows: (1) Glut group: fixation with 0.6% Glut alone; (2) Glut/TA group: fixation with 0.6% Glut and subsequent 0.3% TA. Then the BP samples were subdermally implanted in juvenile male Sprague-Dawley rats and explanted 21 days after implantation. Each explanted BP sample was divided into three parts for calcium content analysis von Kossa's staining and immunohistochemical staining, and reverse transcription-polymerase chain reaction study. Results The data from quantitative calcium analysis and von Kossa's staining showed that Glut-fixed BP developed significantly more calcification than Glut/TA-fixed BP ((90.3+32.5) mg/g dry weight vs (6.4_+1.3) mg/g dry tissue, P 〈0.01). Immunostaining demonstrated lower matrix metalloproteinase-9 and tenascin-C expression as well as macrophage infiltration into Glut/TA-fixed BP than in its Glut-fixed counterpart (P 〈0.01 for all). Additionally, the reverse transcription-polymerase chain reaction study showed that higher levels of expression of matrix metalloproteinase-9 and tenascin-C mRNA occurred within Glut-fixed BP than within the Glut/TA-fixed ones (P 〈0.01 for all). Conclusion TA exerts excellent anti-calcification effects on Glut-fixed BP via inhibiting macrophage infiltration and expression of matrix metalloproteinase-9 and tenascin-C.
文摘Background The European System for Cardiac Operative Risk Evaluation (EuroSCORE) is one of the most widely used risk models for the predicting mortality after cardiac surgery. The aim of this study was to validate the EuroSCORE model for predicting operative mortality in heart valve surgery on a Chinese multicenter database and comparing the performance of EuroSCORE with our new risk stratification system, the Sino System for Coronary Operative Risk Evaluation (SinoSCORE). Methods Data from patients undergoing heart valve surgery between January 2007 and December 2008 were retrospectively collected, from 43 hospitals in China. The EuroSCORE and the SinoSCORE were calculated for each patient. Mortality was defined as any in-hospital death. Area under the receiver operating characteristics curve (AUC) was used to study the discriminatory abilities of the models. The Hosmer-Lemeshow (H-L) goodness-of-fit test was used to study the calibration of the predictive models. Results A total of 15 367 patients were analyzed. For the entire cohort, the observed mortality was 2.34%, the predicted mortality was 3.71% (additive), 3.19% (logistic) and 3.66% (SinoSCORE). AUC was 0.747 for SinoSCORE, 0.699 additive and 0.696 for logistic EuroSCORE. Calibration of SinoSCORE and additive EuroSCORE was good (H-L: P=-0.250 and P=0.051, respectively), but the logistic EuroSCORE model had a poor calibration (H-L: P〈0.05). The discriminatory ability and calibration of the SinoSCORE were good in low- and high-risk patients, However, the discriminatory ability of the EuroSCORE model was poor in all risk deciles. Conclusions The EuroSCORE does not accurately predict mortality in Chinese patients with heart valve surgery, and the SinoSCORE is superior to the EuroSCORE at predicting in-hospital mortality in Chinese heart valve surgery patients.
基金the National Key Research and Development Project of China(2019YFA0801500)Chinese Academy of Medical Sciences Innovation Fund for Medical Sciences(CIFMS,2021-I2M-1-008)the National Natural Science Foundation of China(81770308,81900343)。
文摘The RNA editing tool CRISPR-CasRx has provided a platform for a range of transcriptome analysis tools and therapeutic approaches with its broad efficacy and high specificity.To enable the application of CasRx in vivo,we established a Credependent CasRx knock-in mouse.Using these mice,we specifically knocked down the expression of Meis1 and Hoxb13 in cardiomyocytes,which induced cardiac regeneration after myocardial infarction.We also knocked down the lnc RNA Mhrt in cardiomyocytes with the CasRx knock-in mice,causing hypertrophic cardiomyopathy.In summary,we generated a Credependent CasRx knock-in mouse that can efficiently knock down coding gene and lnc RNA expression in specific somatic cells.This in vivo CRISPR-CasRx system is promising for gene function research and disease modeling.