Apoptosis and hypertrophy of cardiomyocytes are the primary causes of heart failure （HF）, a global leading cause of death, and are regulated through the complicated intracellular signaling network, limiting the deve...Apoptosis and hypertrophy of cardiomyocytes are the primary causes of heart failure （HF）, a global leading cause of death, and are regulated through the complicated intracellular signaling network, limiting the development of effective treatments due to its complexity. To identify effective therapeutic strategies for HF at a system level, we develop a large-scale comprehensive mathematical model of the cardiac signaling network by integrating all available experimental evidence. Attractor landscape analysis of the network model identifies distinct sets of control nodes that effectively suppress apoptosis and hypertrophy of cardiomyocytes under ischemic or pressure overload-induced HF, the two major types of HF. Intriguingly, our system-level analysis suggests that intervention of these control nodes may increase the efficacy of clinical drugs for HF and, of most importance, different combinations of control nodes are suggested as potentially effective candidate drug targets depending on the types of HF. Our study provides a systematic way of developing mechanism-based therapeutic strategies for HF.展开更多
Early detection of sudden cardiac death may be used for surviving the life of cardiac patients. In this paper we have investigated an algorithm to detect and predict sudden cardiac death, by processing of heart rate v...Early detection of sudden cardiac death may be used for surviving the life of cardiac patients. In this paper we have investigated an algorithm to detect and predict sudden cardiac death, by processing of heart rate variability signal through the classical and time-frequency methods. At first, one minute of ECG signals, just before the cardiac death event are extracted and used to compute heart rate variability (HRV) signal. Five features in time domain and four features in frequency domain are extracted from the HRV signal and used as classical linear features. Then the Wigner Ville transform is applied to the HRV signal, and 11 extra features in the time-frequency (TF) domain are obtained. In order to improve the performance of classification, the principal component analysis (PCA) is applied to the obtained features vector. Finally a neural network classifier is applied to the reduced features. The obtained results show that the TF method can classify normal and SCD subjects, more efficiently than the classical methods. A MIT-BIH ECG database was used to evaluate the proposed method. The proposed method was implemented using MLP classifier and had 74.36% and 99.16% correct detection rate (accuracy) for classical features and TF method, respectively. Also, the accuracy of the KNN classifier were 73.87% and 96.04%.展开更多
Previous studies have demonstrated the important role of taurine in inhibiting proliferation of myofibrob lasts（myoFb） and myocardial fibrosis. However, the underlying mechanisms are unclear. The present study was d...Previous studies have demonstrated the important role of taurine in inhibiting proliferation of myofibrob lasts（myoFb） and myocardial fibrosis. However, the underlying mechanisms are unclear. The present study was de signed to shed light on this issue through exploring the signal pathways via in vitro experiments. Angiotension II （AngII） treatment significantly increased myoFb proliferation and the levels of collagens I and III（P〈0.05）, whereas taurine, PKCα（PKC： protein kinase C） specific inhibitor L-threo-dihydro-sphingosine（D4681）, ERK1/2 inhibitor （PD98095） abrogated myoFb proliferation and collagen levels（P〈0.05, P〈0.01, respectively）, and increased the G0/G1 phase rate and decreased S phase rate. Immunocytochemistry, confocal fluorescence staining and image analy sis showed that taurine could inhibit the translocation and expression of p-PKCαin membrane, and then inhibit nuc lear translocation and expression of p-ERK1/2. These results have statistically significant differences compared with those of AngII group（P〈0.01）. Western blot results also show that taurine could inhibit the protein expression of p-PKCα and p-ERK1/2. We used p-PKCα specific inhibitor D4681 in order to elucidate the relationship between p-PKCα and p-ERK1/2 in signal transduction pathways. Finally, the results show that the protein expression of p-ERK1/2 and nuclear translocation were suppressed in D4681 group.展开更多
Objective:To explore the mechanism of Profilin-1 in regulating eNOS/NO pathway and its role in the development of myocardial hypertrophy.Methods:Spontaneously hypertensive rats(SHR) aged 5 weeks were injected with dif...Objective:To explore the mechanism of Profilin-1 in regulating eNOS/NO pathway and its role in the development of myocardial hypertrophy.Methods:Spontaneously hypertensive rats(SHR) aged 5 weeks were injected with different adenovirus vectors to induce Profilin-1expression knockdown(SHR-I) or over express(SHR-H) or to use as control(SHR-C).All these treatment were compared with Wistar-Kyoto rats(SKY) treated with control adenovirus vectors(WKY-C).The same injection was executed at the sixth week during the experiment of 12 weeks.After experiment,the left ventricular weight-to-heart weight ratio(LVW/HW)and left ventricular long axis(LVLA) were measured.Meanwhile.NO contents in blood and myocardium,Profilin-1,eNOS and Caveolin-3 niRNA and protein levels and phosphorylated eNOS(P-eNOS) protein level in myocardium were determined.Results:Compared with WKY-C group,the SHR-C group was statistically higher in LVW/HW(0.79±0.03).LVLA(11.82±0.58 mm) and Profilin-1 niRNA and prolein level(P<0.05).but lower in NO content[(18.63±6.23) μmol/L| in blood and[(2.71±0.17) μmol/L]in myocardium).eNOS activity and Caveolin-3 expression(P<0.05).The over expressing Profilin-1 led SHR-H group to a higher value of LVW/HW[(0.93±0.03) mm and LVLA(14.17±0.69) mm]in comparison with SHR-C group(P<0.05).and to a lower value of NO content(in myocardium).eNOS activity and Caveolin-3 expression(P<0.05):however,this phenomenon was reversed by the knockdown Profilin-1 expression(SHR-I group).Conclusions:Profilin-1 expression,being negative in regulating Caveolin-3 expression and eNOS/NO pathway activity,promotes the development of myocardial hypertrophy which can be reversed by Profilin-1 silencing.展开更多
Objective To investigate the change of c-myc protein, which was chosen as the response indicator to volume-overload. Methods The time and spatial course of c-myc protein expression on the model of rat cardiac volu...Objective To investigate the change of c-myc protein, which was chosen as the response indicator to volume-overload. Methods The time and spatial course of c-myc protein expression on the model of rat cardiac volume-overload hypertrophy was examined by immunohistochemical study. Results The immunohistochemical study indicated the expression of c-myc protein was increased obviously at 4-6 hours (62.73%) than that of control (45.41%, P<0.01) after the volume-overload, then decreased gradually along with development of volume-overload hypertrophy and was decreased extremely at 5 months(r=-0.514,P<0.01).Conclusion There are disorders in the signal transduction pathways governing the hypertrophic response of cardiomyocytes in hypertrophic myocardium. C-myc gene and the product of it may be only the promoter gene of myocardial hypertrophy. Once switching on,c-myc gene and the product of it do not act anymore;While it may be that c-myc gene and the product of it increased following with myocardial hypertrophy, and have not direct relation to the occurrence and development of myocardial hypertrophy.展开更多
The objective of this work is to perform automatic diagnosis using a non invasive method which consists on the bioimpedance signal processing. Bioimpedance signal (BIS) represents the aorta impedance variation during ...The objective of this work is to perform automatic diagnosis using a non invasive method which consists on the bioimpedance signal processing. Bioimpedance signal (BIS) represents the aorta impedance variation during the heart cycle activity. BIS is detected by mean of two electrodes located at the level of the ascendant aorta. Automatic diagnosis method consists on preparing, first, a data base with a set of cepstral parameters of different BIS according to normal case and different cardiac diseases. This data base is composed from n classes Yk corresponding to n diseases. The classification of anonymous individuals is based on the determination of Fisher distance between anonymous disease and class Yk using Fischer formula. Our method permits to calculate seven relevant cepstral parameters. The application of Fisher method has allowed us to perform the diagnosis of five anonymous cases. The major interest of this method is its especially useful for the exploration of cardiovascular system anomalies for emergency cases, children, elderly and pregnant women who can’t support surgical operations especially at the level of the heart.展开更多
文摘Apoptosis and hypertrophy of cardiomyocytes are the primary causes of heart failure （HF）, a global leading cause of death, and are regulated through the complicated intracellular signaling network, limiting the development of effective treatments due to its complexity. To identify effective therapeutic strategies for HF at a system level, we develop a large-scale comprehensive mathematical model of the cardiac signaling network by integrating all available experimental evidence. Attractor landscape analysis of the network model identifies distinct sets of control nodes that effectively suppress apoptosis and hypertrophy of cardiomyocytes under ischemic or pressure overload-induced HF, the two major types of HF. Intriguingly, our system-level analysis suggests that intervention of these control nodes may increase the efficacy of clinical drugs for HF and, of most importance, different combinations of control nodes are suggested as potentially effective candidate drug targets depending on the types of HF. Our study provides a systematic way of developing mechanism-based therapeutic strategies for HF.
文摘Early detection of sudden cardiac death may be used for surviving the life of cardiac patients. In this paper we have investigated an algorithm to detect and predict sudden cardiac death, by processing of heart rate variability signal through the classical and time-frequency methods. At first, one minute of ECG signals, just before the cardiac death event are extracted and used to compute heart rate variability (HRV) signal. Five features in time domain and four features in frequency domain are extracted from the HRV signal and used as classical linear features. Then the Wigner Ville transform is applied to the HRV signal, and 11 extra features in the time-frequency (TF) domain are obtained. In order to improve the performance of classification, the principal component analysis (PCA) is applied to the obtained features vector. Finally a neural network classifier is applied to the reduced features. The obtained results show that the TF method can classify normal and SCD subjects, more efficiently than the classical methods. A MIT-BIH ECG database was used to evaluate the proposed method. The proposed method was implemented using MLP classifier and had 74.36% and 99.16% correct detection rate (accuracy) for classical features and TF method, respectively. Also, the accuracy of the KNN classifier were 73.87% and 96.04%.
基金Supported by the National Basic Research Program of China(No.2007CB512006)the National Natural Science Founda-tion of China(No.30873066/C180102)
文摘Previous studies have demonstrated the important role of taurine in inhibiting proliferation of myofibrob lasts（myoFb） and myocardial fibrosis. However, the underlying mechanisms are unclear. The present study was de signed to shed light on this issue through exploring the signal pathways via in vitro experiments. Angiotension II （AngII） treatment significantly increased myoFb proliferation and the levels of collagens I and III（P〈0.05）, whereas taurine, PKCα（PKC： protein kinase C） specific inhibitor L-threo-dihydro-sphingosine（D4681）, ERK1/2 inhibitor （PD98095） abrogated myoFb proliferation and collagen levels（P〈0.05, P〈0.01, respectively）, and increased the G0/G1 phase rate and decreased S phase rate. Immunocytochemistry, confocal fluorescence staining and image analy sis showed that taurine could inhibit the translocation and expression of p-PKCαin membrane, and then inhibit nuc lear translocation and expression of p-ERK1/2. These results have statistically significant differences compared with those of AngII group（P〈0.01）. Western blot results also show that taurine could inhibit the protein expression of p-PKCα and p-ERK1/2. We used p-PKCα specific inhibitor D4681 in order to elucidate the relationship between p-PKCα and p-ERK1/2 in signal transduction pathways. Finally, the results show that the protein expression of p-ERK1/2 and nuclear translocation were suppressed in D4681 group.
基金funded by Key Disciplines Group Construction Project of Pudong Health Bureau of Shanghai(No.PWZxq2014-01)Natural Science Foundation of China(No.81401428)the fund of the Academic Leaders Training Program of Pudong Health Bureau of Shanghai(No.PWRd2013-02)
文摘Objective:To explore the mechanism of Profilin-1 in regulating eNOS/NO pathway and its role in the development of myocardial hypertrophy.Methods:Spontaneously hypertensive rats(SHR) aged 5 weeks were injected with different adenovirus vectors to induce Profilin-1expression knockdown(SHR-I) or over express(SHR-H) or to use as control(SHR-C).All these treatment were compared with Wistar-Kyoto rats(SKY) treated with control adenovirus vectors(WKY-C).The same injection was executed at the sixth week during the experiment of 12 weeks.After experiment,the left ventricular weight-to-heart weight ratio(LVW/HW)and left ventricular long axis(LVLA) were measured.Meanwhile.NO contents in blood and myocardium,Profilin-1,eNOS and Caveolin-3 niRNA and protein levels and phosphorylated eNOS(P-eNOS) protein level in myocardium were determined.Results:Compared with WKY-C group,the SHR-C group was statistically higher in LVW/HW(0.79±0.03).LVLA(11.82±0.58 mm) and Profilin-1 niRNA and prolein level(P<0.05).but lower in NO content[(18.63±6.23) μmol/L| in blood and[(2.71±0.17) μmol/L]in myocardium).eNOS activity and Caveolin-3 expression(P<0.05).The over expressing Profilin-1 led SHR-H group to a higher value of LVW/HW[(0.93±0.03) mm and LVLA(14.17±0.69) mm]in comparison with SHR-C group(P<0.05).and to a lower value of NO content(in myocardium).eNOS activity and Caveolin-3 expression(P<0.05):however,this phenomenon was reversed by the knockdown Profilin-1 expression(SHR-I group).Conclusions:Profilin-1 expression,being negative in regulating Caveolin-3 expression and eNOS/NO pathway activity,promotes the development of myocardial hypertrophy which can be reversed by Profilin-1 silencing.
文摘Objective To investigate the change of c-myc protein, which was chosen as the response indicator to volume-overload. Methods The time and spatial course of c-myc protein expression on the model of rat cardiac volume-overload hypertrophy was examined by immunohistochemical study. Results The immunohistochemical study indicated the expression of c-myc protein was increased obviously at 4-6 hours (62.73%) than that of control (45.41%, P<0.01) after the volume-overload, then decreased gradually along with development of volume-overload hypertrophy and was decreased extremely at 5 months(r=-0.514,P<0.01).Conclusion There are disorders in the signal transduction pathways governing the hypertrophic response of cardiomyocytes in hypertrophic myocardium. C-myc gene and the product of it may be only the promoter gene of myocardial hypertrophy. Once switching on,c-myc gene and the product of it do not act anymore;While it may be that c-myc gene and the product of it increased following with myocardial hypertrophy, and have not direct relation to the occurrence and development of myocardial hypertrophy.
文摘The objective of this work is to perform automatic diagnosis using a non invasive method which consists on the bioimpedance signal processing. Bioimpedance signal (BIS) represents the aorta impedance variation during the heart cycle activity. BIS is detected by mean of two electrodes located at the level of the ascendant aorta. Automatic diagnosis method consists on preparing, first, a data base with a set of cepstral parameters of different BIS according to normal case and different cardiac diseases. This data base is composed from n classes Yk corresponding to n diseases. The classification of anonymous individuals is based on the determination of Fisher distance between anonymous disease and class Yk using Fischer formula. Our method permits to calculate seven relevant cepstral parameters. The application of Fisher method has allowed us to perform the diagnosis of five anonymous cases. The major interest of this method is its especially useful for the exploration of cardiovascular system anomalies for emergency cases, children, elderly and pregnant women who can’t support surgical operations especially at the level of the heart.
