Two major apoptosis pathways have been defined in mammalian cells, the Fas/TNF-R1 death receptor pathway and the mitochondria pathway. The Bcl-2 family proteins consist of both anti-apoptosis and pro- apoptosis member...Two major apoptosis pathways have been defined in mammalian cells, the Fas/TNF-R1 death receptor pathway and the mitochondria pathway. The Bcl-2 family proteins consist of both anti-apoptosis and pro- apoptosis members that regulate apoptosis, mainly by controlling the release of cytochrome c and other mitochondrial apoptotic events. However, death signals mediated by Fas/TNF-R1 receptors can usually activate caspases directly, bypassing the need for mitochondria and escaping the regulation by Bcl-2 family proteins. Bid is a novel pro-apoptosis Bcl-2 family protein that is activated by caspase 8 in response to Fas/TNF-R1 death receptor signals. Activated Bid is translocated to mitochondria and induces cytochrome c release, which in turn activates downstream caspases. Such a connection between the two apoptosis pathways could be important for induction of apoptosis in certain types of cells and responsible for the pathogenesis of a number of human diseases.展开更多
In order to study the effects of ethyl pyruvate on cardiomyocyte apoptosis following ischemia/reperfusion （I/R） in vitro and the expression of Bcl-2 and Bax proteins, isolated rat hearts were perfused in a Langendor...In order to study the effects of ethyl pyruvate on cardiomyocyte apoptosis following ischemia/reperfusion （I/R） in vitro and the expression of Bcl-2 and Bax proteins, isolated rat hearts were perfused in a Langendorff model. Twenty-four rats were randomly divided into 3 groups （n=8 in each group）： control group was perfused for 120 min. In the I/R group, after 30 min stabilization the injury was induced by 30 min global ischemia followed by 60 min reperfusion. Ethyl pyruvate （EP） group was set up with the same protocol as I/R group except that it was supplied with 2 mmol/L EP 15 rain before ischemia and throughout reperfusion. Myocardial malonaldehyde （MDA） content was measured. Myocardial apoptotic index （AI） was tested by terminal deoxynucleotidyl transferase mediated dUTP nick end labeling （TUNEL） method. The expression of anti-apoptotic protein Bcl-2 and pro-apoptotic protein Bax in cardiac myocytes was detected by immunohistochemistry. As compared with control group, the content of MDA, myocardial AI and the expression of Bcl-2, Bax proteins were increased significantly in I/R group, but the content of MDA, myocardial AI and the expression of Bax protein were decreased obviously and the expression of Bcl-2 protein was up-regulated in EP group （P〈0.05）. These results demonstrate that EP could inhibit apoptosis of cardiac myocytes possibly via alleviating oxidative stress, up-regulating Bcl-2 and down-regulating Bax proteins.展开更多
Dioscin is a natural steroid saponin derived from several plants, showing potent anti-cancer effect against a variety of tumor cell lines. In the present study, we investigated the anti-cancer activity of dioscin agai...Dioscin is a natural steroid saponin derived from several plants, showing potent anti-cancer effect against a variety of tumor cell lines. In the present study, we investigated the anti-cancer activity of dioscin against human LNCaP cells, and evaluated the possible mechanism involved in its antineoplastic action. It was found that dioscin（1, 2 and 4 μmol/L） could significantly inhibit the viability of LNCaP cells in a time- and concentration-dependent manner. Flow cytometry revealed that the apoptosis rate was increased after treatment of LNCaP cells with dioscin for 24 h, indicating that apoptosis was an important mechanism by which dioscin inhibited cancer. Western blotting was employed to detect the expression of caspase-3, Bcl-2 and Bax in LNCaP cells. The expression of cleaved caspase-3 was significantly increased, and meanwhile procaspase-3 was markedly decreased. The expression of anti-apoptotic protein Bcl-2 was down-regulated, whereas the pro-apoptotic protein Bax was up-regulated. Moreover, the Bcl-2/Bax ratio was drastically decreased. These results suggested that dioscin possessed potential anti-tumor activity in human LNCaP cells through the apoptosis pathway, which might be associated with caspase-3 and Bcl-2 protein family.展开更多
INTRODUCTIONIn China ,the incidence and mortality of gastric cancer rank the second among all cancers. Recent development of cancer [1-20].The aim of this study was investigat the insight of apoptosis and bcl-2, p53 a...INTRODUCTIONIn China ,the incidence and mortality of gastric cancer rank the second among all cancers. Recent development of cancer [1-20].The aim of this study was investigat the insight of apoptosis and bcl-2, p53 and C-myc protein expression in the development of gastric cancer .展开更多
Objective To study whether there is the apoptosis of neural cells and the expression of Bcl-2 protein in intracerebral hemorrhage (ICH) in model of rats, for the further understanding the mechanism of the delayed dama...Objective To study whether there is the apoptosis of neural cells and the expression of Bcl-2 protein in intracerebral hemorrhage (ICH) in model of rats, for the further understanding the mechanism of the delayed damage of the neural cells around the hematoma after ICH. Methods Fifty SD rats were randomly divided into 5 groups, ten in each. With the Group A as the control, the rest 40 were used to set up intracerebral hemorrhage model. The brains were taken out at 12 th , 24 th , 48 th and 72 th hours, respectively. Apoptosis cells were detected with terminal deoxynucleotidyl transferase mediated dUTP nick end labeling (TUNEL), and the expression of Bcl-2 protein was detected with immunochemical stainging methed (SP). Results In the control group, no apoptosis cells and Bc1-2 protein were detected. In rest groups, the apoptosis cells and Bc1-2 protein were expressed in different degree. Apoptosis rates verified and corresponded with the time after ICH, with the peak at 48 th -72 th hour after hemorrhage. The peak rate of apoptosis cells was (24.50±2.69)% and Bcl-2 protein expression was (20.76±1.97)% . There was significant difference between the experimental groups and control (P<0.05), and no linear relationship between the apoptosis rate and the expression of Bcl-2 protein. Conclusion Apoptosis may be an important factor in the secondary trauma of ICH. There is a time leg after hemorrhage. All this is instructive to clinical treatment in time. Bcl-2 protein keeps increasing in a certain time after hemorrhage, but not synchronize with the cell apoptosis. This indicates that bcl-2 has the effect to reduce the apoptosis of neural cells.展开更多
BAOKGROUND： Bcl-2 and Fas proteins are well known as anti-apoptotic and pro-apoptotic factors respectively. However, whether the anti-epileptic mechanism of low-frequency repetitive transcranial magnetic stimulation ...BAOKGROUND： Bcl-2 and Fas proteins are well known as anti-apoptotic and pro-apoptotic factors respectively. However, whether the anti-epileptic mechanism of low-frequency repetitive transcranial magnetic stimulation （rTMS） involves an anti-apoptotic effect via regulating Bcl-2 and Fas protein expression remains to be determined. OBJECTIVE： To verify the correlation between the anti-epileptic mechanism following pretreatment of low-frequency rTMS and anti-hippocampal apoptosis. DESIGN, TIME AND SETTING： A randomized controlled animal experiment was performed at Institute of Neurological Disorders, Affiliated Hospital of North Sichuan Medical College between September 2007 and March 2008. MATERIALS： Pilocarpine （053K13011） was provided by Sigma, USA; lithium was provided by Shanghai Biotechnology Co., Ltd., China; Dantec Maglite-r25 rTMS instrument was provided by Dundee, Denmark. METHODS： A total of 21 adult male Wistar rats were randomly divided into control （n = 6）, rTMS pretreatment （n = 9）, and sham-stimulation （n = 6） groups. The rTMS pretreatment group was pretreated with low-frequency rTMS （0.5 Hz, 75% threshold intensity, 20 times/bundle, and 5 bundles/day）, while the sham-stimulation group was sham-stimulated with a similar sound for 7 successive days to establish lithium-pilocarpine-induced epileptic state models. MAIN OUTCOME MEASURES： Epileptic stroke latency; neuronal morphology was observed using hematoxylin and eosin staining; mean positive-reactive cell number and mean absorbance of Bcl-2 and Fas protein in the hippocampal CA1 region was observed using immunohistochemistry. RESULTS： Epileptic latency in the rTMS pretreatment group was significantly enhanced （P 〈 0.01）, and a number of degenerated neurons were observed to be apoptotic. Bcl-2 protein expression increased at each time point, but Fas protein expression decreased （P 〈 0.01）. CONCLUSION： Low-frequency rTMS has an anti-epileptic effect, which may be via regulation of Bcl-2 and Fas protein expression in the hippocampal region.展开更多
Trail, a tumor necrosis factor-related apoptosis-inducing ligand, is a novel potent endogenous activator of the cell death pathway through the activation of cell surface death receptors Trail-R1 and Trail-R2. Its role...Trail, a tumor necrosis factor-related apoptosis-inducing ligand, is a novel potent endogenous activator of the cell death pathway through the activation of cell surface death receptors Trail-R1 and Trail-R2. Its role, like FasL in activation-induced cell death (AICD), has been demonstrated in immune system. However the mechanism of Trail induced apoptosis remains nuclear. In this report, the recombinant Trail protein was expressed and purified. The apoptosis-inducing activity and the regulation mechanism of recombinant Trail on Jurkat T cells were explored in vitro. Trypan blue exclusion assay demonstrated that the recombinant Trail protein actively killed Jurkat T cells in a dose-dependent manner. Trail-induced apoptosis in Jurkat T cells were remarkably reduced by Bcl-2 over expression in BcL-2 gene transfected cells. Treatment with PMA (phorbol 12-myristate 13-acetate), a PKC activator, suppressed nail-induced apoptosis in Jurkat T cells. The inhibition of apoptosis by PMA was abolished by pretreatment with Bis, a PKC inhibitor. Taken together, it was suggested that Bcl-2 over-expression and PMA activated PKC actively down-regulated the Trail-mediated apoptosis in Jurkat T cell.展开更多
文摘Two major apoptosis pathways have been defined in mammalian cells, the Fas/TNF-R1 death receptor pathway and the mitochondria pathway. The Bcl-2 family proteins consist of both anti-apoptosis and pro- apoptosis members that regulate apoptosis, mainly by controlling the release of cytochrome c and other mitochondrial apoptotic events. However, death signals mediated by Fas/TNF-R1 receptors can usually activate caspases directly, bypassing the need for mitochondria and escaping the regulation by Bcl-2 family proteins. Bid is a novel pro-apoptosis Bcl-2 family protein that is activated by caspase 8 in response to Fas/TNF-R1 death receptor signals. Activated Bid is translocated to mitochondria and induces cytochrome c release, which in turn activates downstream caspases. Such a connection between the two apoptosis pathways could be important for induction of apoptosis in certain types of cells and responsible for the pathogenesis of a number of human diseases.
文摘In order to study the effects of ethyl pyruvate on cardiomyocyte apoptosis following ischemia/reperfusion （I/R） in vitro and the expression of Bcl-2 and Bax proteins, isolated rat hearts were perfused in a Langendorff model. Twenty-four rats were randomly divided into 3 groups （n=8 in each group）： control group was perfused for 120 min. In the I/R group, after 30 min stabilization the injury was induced by 30 min global ischemia followed by 60 min reperfusion. Ethyl pyruvate （EP） group was set up with the same protocol as I/R group except that it was supplied with 2 mmol/L EP 15 rain before ischemia and throughout reperfusion. Myocardial malonaldehyde （MDA） content was measured. Myocardial apoptotic index （AI） was tested by terminal deoxynucleotidyl transferase mediated dUTP nick end labeling （TUNEL） method. The expression of anti-apoptotic protein Bcl-2 and pro-apoptotic protein Bax in cardiac myocytes was detected by immunohistochemistry. As compared with control group, the content of MDA, myocardial AI and the expression of Bcl-2, Bax proteins were increased significantly in I/R group, but the content of MDA, myocardial AI and the expression of Bax protein were decreased obviously and the expression of Bcl-2 protein was up-regulated in EP group （P〈0.05）. These results demonstrate that EP could inhibit apoptosis of cardiac myocytes possibly via alleviating oxidative stress, up-regulating Bcl-2 and down-regulating Bax proteins.
基金supported by the National Natural Science Foundation of China(No.81173065)
文摘Dioscin is a natural steroid saponin derived from several plants, showing potent anti-cancer effect against a variety of tumor cell lines. In the present study, we investigated the anti-cancer activity of dioscin against human LNCaP cells, and evaluated the possible mechanism involved in its antineoplastic action. It was found that dioscin（1, 2 and 4 μmol/L） could significantly inhibit the viability of LNCaP cells in a time- and concentration-dependent manner. Flow cytometry revealed that the apoptosis rate was increased after treatment of LNCaP cells with dioscin for 24 h, indicating that apoptosis was an important mechanism by which dioscin inhibited cancer. Western blotting was employed to detect the expression of caspase-3, Bcl-2 and Bax in LNCaP cells. The expression of cleaved caspase-3 was significantly increased, and meanwhile procaspase-3 was markedly decreased. The expression of anti-apoptotic protein Bcl-2 was down-regulated, whereas the pro-apoptotic protein Bax was up-regulated. Moreover, the Bcl-2/Bax ratio was drastically decreased. These results suggested that dioscin possessed potential anti-tumor activity in human LNCaP cells through the apoptosis pathway, which might be associated with caspase-3 and Bcl-2 protein family.
基金Supported by the Medical Research Foundation of Guangdong Province,No.1997423
文摘INTRODUCTIONIn China ,the incidence and mortality of gastric cancer rank the second among all cancers. Recent development of cancer [1-20].The aim of this study was investigat the insight of apoptosis and bcl-2, p53 and C-myc protein expression in the development of gastric cancer .
文摘Objective To study whether there is the apoptosis of neural cells and the expression of Bcl-2 protein in intracerebral hemorrhage (ICH) in model of rats, for the further understanding the mechanism of the delayed damage of the neural cells around the hematoma after ICH. Methods Fifty SD rats were randomly divided into 5 groups, ten in each. With the Group A as the control, the rest 40 were used to set up intracerebral hemorrhage model. The brains were taken out at 12 th , 24 th , 48 th and 72 th hours, respectively. Apoptosis cells were detected with terminal deoxynucleotidyl transferase mediated dUTP nick end labeling (TUNEL), and the expression of Bcl-2 protein was detected with immunochemical stainging methed (SP). Results In the control group, no apoptosis cells and Bc1-2 protein were detected. In rest groups, the apoptosis cells and Bc1-2 protein were expressed in different degree. Apoptosis rates verified and corresponded with the time after ICH, with the peak at 48 th -72 th hour after hemorrhage. The peak rate of apoptosis cells was (24.50±2.69)% and Bcl-2 protein expression was (20.76±1.97)% . There was significant difference between the experimental groups and control (P<0.05), and no linear relationship between the apoptosis rate and the expression of Bcl-2 protein. Conclusion Apoptosis may be an important factor in the secondary trauma of ICH. There is a time leg after hemorrhage. All this is instructive to clinical treatment in time. Bcl-2 protein keeps increasing in a certain time after hemorrhage, but not synchronize with the cell apoptosis. This indicates that bcl-2 has the effect to reduce the apoptosis of neural cells.
基金Youth Foundation Project of Sichuan Province, No. 04ZQ026-010
文摘BAOKGROUND： Bcl-2 and Fas proteins are well known as anti-apoptotic and pro-apoptotic factors respectively. However, whether the anti-epileptic mechanism of low-frequency repetitive transcranial magnetic stimulation （rTMS） involves an anti-apoptotic effect via regulating Bcl-2 and Fas protein expression remains to be determined. OBJECTIVE： To verify the correlation between the anti-epileptic mechanism following pretreatment of low-frequency rTMS and anti-hippocampal apoptosis. DESIGN, TIME AND SETTING： A randomized controlled animal experiment was performed at Institute of Neurological Disorders, Affiliated Hospital of North Sichuan Medical College between September 2007 and March 2008. MATERIALS： Pilocarpine （053K13011） was provided by Sigma, USA; lithium was provided by Shanghai Biotechnology Co., Ltd., China; Dantec Maglite-r25 rTMS instrument was provided by Dundee, Denmark. METHODS： A total of 21 adult male Wistar rats were randomly divided into control （n = 6）, rTMS pretreatment （n = 9）, and sham-stimulation （n = 6） groups. The rTMS pretreatment group was pretreated with low-frequency rTMS （0.5 Hz, 75% threshold intensity, 20 times/bundle, and 5 bundles/day）, while the sham-stimulation group was sham-stimulated with a similar sound for 7 successive days to establish lithium-pilocarpine-induced epileptic state models. MAIN OUTCOME MEASURES： Epileptic stroke latency; neuronal morphology was observed using hematoxylin and eosin staining; mean positive-reactive cell number and mean absorbance of Bcl-2 and Fas protein in the hippocampal CA1 region was observed using immunohistochemistry. RESULTS： Epileptic latency in the rTMS pretreatment group was significantly enhanced （P 〈 0.01）, and a number of degenerated neurons were observed to be apoptotic. Bcl-2 protein expression increased at each time point, but Fas protein expression decreased （P 〈 0.01）. CONCLUSION： Low-frequency rTMS has an anti-epileptic effect, which may be via regulation of Bcl-2 and Fas protein expression in the hippocampal region.
基金Major State BasicResearch (973) Program of China, (G1999053905).
文摘Trail, a tumor necrosis factor-related apoptosis-inducing ligand, is a novel potent endogenous activator of the cell death pathway through the activation of cell surface death receptors Trail-R1 and Trail-R2. Its role, like FasL in activation-induced cell death (AICD), has been demonstrated in immune system. However the mechanism of Trail induced apoptosis remains nuclear. In this report, the recombinant Trail protein was expressed and purified. The apoptosis-inducing activity and the regulation mechanism of recombinant Trail on Jurkat T cells were explored in vitro. Trypan blue exclusion assay demonstrated that the recombinant Trail protein actively killed Jurkat T cells in a dose-dependent manner. Trail-induced apoptosis in Jurkat T cells were remarkably reduced by Bcl-2 over expression in BcL-2 gene transfected cells. Treatment with PMA (phorbol 12-myristate 13-acetate), a PKC activator, suppressed nail-induced apoptosis in Jurkat T cells. The inhibition of apoptosis by PMA was abolished by pretreatment with Bis, a PKC inhibitor. Taken together, it was suggested that Bcl-2 over-expression and PMA activated PKC actively down-regulated the Trail-mediated apoptosis in Jurkat T cell.
