AIM: To analyze the protein expression essential for apoptosis in liver steatosis. METHODS: The expression of proapoptotic proteins p53, Bax, and antiapoptotic Bcl-2 in hepatocytes with steatosis (SH) and without stea...AIM: To analyze the protein expression essential for apoptosis in liver steatosis. METHODS: The expression of proapoptotic proteins p53, Bax, and antiapoptotic Bcl-2 in hepatocytes with steatosis (SH) and without steatosis (NSH) was evaluated in 84 patients at various stages of non-alcoholic fatty liver disease (NAFLD). RESULTS: Immunohistochemical staining of liver tissue showed the activation of p53 protein in SH and NSH with increased liver steatosis, diminished Bcl-2 and slightly decreased Bax protein. Positive correlation was found between the stage of liver steatosis with p53 expression in SH (r = 0.54, P < 0.01) and NSH (r = 0.49, P < 0.01). The antiapoptotic protein Bcl-2 was diminished together with the advancement of liver steatosis, especially in non-steatosed hepatocytes (r =0.43, P < 001). CONCLUSION: Apoptosis is one of the most important mechanisms leading to hepatocyte elimination in NAFLD. The intensification of inflammation in NAFLD induces proapoptotic protein p53 with the inhibition of antiapoptotic Bcl-2.展开更多
The fresh water polyp Hydra belongs to the phylum Cnidaria, which diverged from the metazoan lineage before the appearance of bilaterians. In order to understand the evolution of apoptosis in metazoans, we have begun ...The fresh water polyp Hydra belongs to the phylum Cnidaria, which diverged from the metazoan lineage before the appearance of bilaterians. In order to understand the evolution of apoptosis in metazoans, we have begun to elucidate the molecular cell death machinery in this model organism. Based on ESTs and the whole Hydra genome assembly, we have identified 15 caspases. We show that one is activated during apoptosis, four have characteristics of initiator caspases with N-terminal DED, CARD or DD domain and two undergo autoprocessing in vitro. In addition, we describe seven Bcl-2-1ike and two Bak-like proteins. For most of the Bcl-2 family proteins, we have observed mitochondrial localization. When expressed in mammalian cells, HyBak-like 1 and 2 strongly induced apoptosis. Six of the Bcl-2 family members inhibited apoptosis induced by camptothecin in mammalian ceils with HyBcl-2-1ike 4 showing an especially strong protective effect. This protein also interacted with HyBak-like 1 in a yeast two-hybrid assay. Mutation of the conserved leucine in its BH3 domain abolished both the interaction with HyBak-like 1 and the anti-apoptotic effect. Moreover, we describe novel Hydra BH-3-only proteins. One of these interacted with Bcl-2-1ike 4 and induced apoptosis in mammalian cells. Our data indicate that the evolution of a complex network for cell death regulation arose at the earliest and simplest level of multicellular organization, where it exhibited a substantially higher level of complexity than in the protostome model organisms Caenorhabditis and Drosophila.展开更多
The BH3 mimetics targeting the interaction between the BH3-only proteins and their prosurvival Bcl-2family proteins have shown enormous potential as cancer therapeutics. Herein, seven analogues targeting anti-apoptoti...The BH3 mimetics targeting the interaction between the BH3-only proteins and their prosurvival Bcl-2family proteins have shown enormous potential as cancer therapeutics. Herein, seven analogues targeting anti-apoptotic Bcl-2 proteins derived from the Bim BH3 domain via sequence simplification and/or modification are described. The in vitro binding affinity on anti-apoptotic Bcl-2 proteins and cell killing activity were evaluated. The results showed that analogues could significantly bind to target proteins and exhibited anti-cancer effect against three cancer cell lines. Of particular interest were the analogue SM-5(KD= 9.48 nmol/L for Bcl-2) and SM-6(KD= 0.08 nmol/L for Bcl-xL), which exhibited improved binding affinity compared with the lead Bim(KD= 16.90 nmol/L for Bcl-2 and 22.2 nmol/L for Bcl-xL, respectively). These results indicated that the peptide sequence containing the four hydrophobic side chains occupying pockets within the BH3-recognition cleft of anti-apoptotic Bcl-2 proteins might be the minimum sequence required for the bioactivity and the active core region of Bim. Promising inhibitors of anti-apoptotic Bcl-2 proteins with high bioactivity might be designed based on the active core.展开更多
Walnut dreg protein hydrolysates(WDPHs)exhibit a variety of biological activities,however,the cyclooxygenase-2(COX-2)inhibitory peptide of WDPHs remain unclear.The aim of this study was to rapidly screen for such pept...Walnut dreg protein hydrolysates(WDPHs)exhibit a variety of biological activities,however,the cyclooxygenase-2(COX-2)inhibitory peptide of WDPHs remain unclear.The aim of this study was to rapidly screen for such peptides in WDPHs through a combination of in silico and in vitro analysis.In total,1262 peptide sequences were observed by nano liquid chromatography/tandem mass spectrometry(nano LC-MS/MS)and 4 novel COX-2 inhibitory peptides(AGFP,FPGA,LFPD,and VGFP)were identified.Enzyme kinetic data indicated that AGFP,FPGA,and LFPD displayed mixed-type COX-2 inhibition,whereas VGFP was a non-competitive inhibitor.This is mainly because the peptides form hydrogen bonds and hydrophobic interactions with residues in the COX-2 active site.These results demonstrate that computer analysis combined with in vitro evaluation allows for rapid screening of COX-2 inhibitory peptides in walnut protein dregs.展开更多
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
AIM To study the expression of Fas and Bcl 2 proteins in BEL 7404 human hepatoma cells in order to analyze the possible relationship between cell growth regulation by alpha fetoprotein(AFP) and Fas/Bcl 2 prot...AIM To study the expression of Fas and Bcl 2 proteins in BEL 7404 human hepatoma cells in order to analyze the possible relationship between cell growth regulation by alpha fetoprotein(AFP) and Fas/Bcl 2 proteins. METHODS BEL 7404 human hepatoma cells were maintained in RPMI 1640 medium supplemented with 10% new born calf serum. Cells adhered to coverslips were used to detect Fas and Bcl 2 protein expression by the avidin biotin complex (ABC) immunocytochemical assay. RESULTS Immunocytochemical study showed that essentially all the BEL 7404 human hepatoma cells could express Fas and Bcl 2 proteins, although in various amounts. No positive staining for Fas and Bcl 2 proteins was observed when cells were incubated with non relevant sera to establish the specificity. CONCLUSION Fas apoptosis signals and Bcl 2 rescue/survival signals from apoptosis are expressed in BEL 7404 human hepatoma cells. The finding strongly implys that AFP mediated cell apoptosis and growth enhancement are potentially associated with Fas and Bcl 2 proteins present in those cells.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
Summary: Whether conventional hypothermic CPB induces myocyte apoptosis in dog hearts and modulation of bcl-2, bcl-xl, bax, bad, and caspase-3 pathways in this setting was investigated. Ten healthy adult dogs were ra...Summary: Whether conventional hypothermic CPB induces myocyte apoptosis in dog hearts and modulation of bcl-2, bcl-xl, bax, bad, and caspase-3 pathways in this setting was investigated. Ten healthy adult dogs were randomized into sham-operated and CPB groups. Samples of left ventricle were obtained before, during and 3 h after CPB. In situ TUNEL was used to detect apoptotic myocytes. Immunohistochemistry and flow cytometry were employed for detection of expressions of bcl-2, bcl-xl, bax and bad proteins. Z-DEVD-AMC substrate cleavage and TBARS methods were used to measure the activity of caspase-3 and the content of lipid peroxide in LV myocardium, respectively. After CPB, the number of apoptotic myocytes in CPB group was significantly increased. The results of immunohistichemistry demonstrated that bcl-2, bcl-xl, bax and bad proteins were constitutionally present on the sarcolemma of the LV myocytes. FACS results showed that, after CPB, expressions of bax and bad in CPB group were significantly upregulated, while the expressions of bcl-2 and bcl-xl were not significantly changed in both groups. The activity of caspase-3 and the content of lipid peroxide in LV myocardium in CPB group were also significantly increased after CPB. The present study shows that there exists myocardiocyte apoptosis in dog hearts undergoing conventional hypothermic CPB and the myocyte apoptosis is initiated by ischemia and performed during reperfusion. Moreover, the CPB-induced myocyte apoptosis was associated with upregulation of expressions of bax and bad proteins, activation of caspase-3 and increase of oxidative stress.展开更多
Commitment of cells to apoptosis is governed largely by protein-protein interactions between members of the Bcl-2 protein family. Its three sub-families have distinct roles: the BH3-only proteins trigger apoptosis by...Commitment of cells to apoptosis is governed largely by protein-protein interactions between members of the Bcl-2 protein family. Its three sub-families have distinct roles: the BH3-only proteins trigger apoptosis by binding via their BH3 domain to pro-survival relatives, while the pro-apoptotic Bax and Bak have an essential downstream role involving disruption of organellar membranes and induction of caspase activation. The BH3-only proteins act as damage sensors, held inert until their activation by stress signals. Once activated, they were thought to bind promiscuously to pro-survival protein targets but unexpected selectivity has recently emerged from analysis of their interactions. Some BH3-only proteins also bind to Bax and Bak. Whether Bax and Bak are activated directly by these BH3-only proteins, or indirectly as a consequence of BH3-only proteins neutralizing their pro-survival targets is the subject of intense debate. Regardless of this, a detailed understanding of the interactions between family members, which are often selective, has notable implications for designing anti-cancer drugs to target the Bcl-2 family.展开更多
Objective: To study the relationship between the expression of Bax, Bcl 2 proteins, and apoptosis in radiation compound wound healing of rats. Methods: Apoptosis, Bax and Bcl 2 proteins were estimated by in situ termi...Objective: To study the relationship between the expression of Bax, Bcl 2 proteins, and apoptosis in radiation compound wound healing of rats. Methods: Apoptosis, Bax and Bcl 2 proteins were estimated by in situ terminal labeling (TUNEL) and immunohistochemical methods. Results: (1) Changes of the apoptosis in wound healing showed three typical characteristics: early occurrence, high frequency and delayed disappearance after radiation to rats when compared with those of simple wound group, which might be an important reason for radiation induced delayed wound healing. (2) The expression of Bax protein increased evidently with the increment of apoptosis and showed a good corresponding relationship with the apoptotic frequency in the process of wound healing. While the expression of Bcl 2 protein decreased obviously as the apoptosis reached a maximum and showed increasing tendency up to normal level when the apoptosis decreased distinctively. Conclusions: Bax and Bcl 2 proteins play an important role in the apoptotic regulation of radiation compound wound healing in rats.展开更多
Genistein is one of several isoflavones that has a structure similar to 17β-estradiol, has a strong antioxidant effect, and a high affinity to estrogen receptors. At 15 weeks after ovariectomy, the expression of Bcl-...Genistein is one of several isoflavones that has a structure similar to 17β-estradiol, has a strong antioxidant effect, and a high affinity to estrogen receptors. At 15 weeks after ovariectomy, the expression of Bcl-2 in the hippocampus of rats decreased and Bax expression increased, with an obvious upregulation of apoptosis. However, intraperitoneal injection of genistein or 17β-estradiol for 15 consecutive weeks from the second day after operation upregulated Bcl-2 protein expression downregulated Bax protein expression, and attenuated hippocampal neuron apoptosis. Our experimental findings indicate that long-term intervention with genistein can lead to a decrease in apoptosis in hippocampal neurons following ovadectomy, upregulate the expression of Bcl-2, and downregulate the expression of Bax. In addition, genistein and 17β-estradiol play equal anti-apoptotic and neuroprotective roles.展开更多
Objective To investigate the variance of expression of bcl-2 and bax genes in the genesis or gastric carcinoma as well as their relationship. Methods Thirty-five cases of early-stage gastric carcinoma and Twenty-four ...Objective To investigate the variance of expression of bcl-2 and bax genes in the genesis or gastric carcinoma as well as their relationship. Methods Thirty-five cases of early-stage gastric carcinoma and Twenty-four cases ot chronic atrophic gastritis were studied by immunohistochemical method. Results There were no statistical differences of bcl-2 expression levels between gastric carcinoma and atypical hyperplasia or paracancerous intestinal- epithelial metaplasia(IEM) (P>0.05).There were statistical differences of bcl-2 expression between normal epithe- lial tissues (or non-cancerous IEM) and the other three groups(P<0.05), but no statistical difference between the normal epithelial and the non-cancerous IEM group was observed(P>0.05). The expressions or bax protein were found in the normal epithelial and the other groups in varying degrees,but there were no statistical differences be- tween either two of the groups (P>0.05). The bcl-2/bax ratio was higher in early-stage gastric carcinoma,atypical hy- perplasia and paracancerous intestinal-metaplasia than in the non-cancerous intestinal-metaplasia (P<0.05) and nor- mal epithelial tissues(P<0.01). Conclusion The abnormal expression of bcl-2 protein and bax protein,especially the increased bcl-2/bax ratio, probably play an important role in the course of carcinogenesis or gastric carcinoma.展开更多
AIM : To study the effects of PAMd ( Phenolic alkaloids from Menispermum dauricum on Brain ischemia and ischemic reperfusion injury in mice. METHODS : Bilateral carotid arteries of mice were ligated and 0. 3ml blood w...AIM : To study the effects of PAMd ( Phenolic alkaloids from Menispermum dauricum on Brain ischemia and ischemic reperfusion injury in mice. METHODS : Bilateral carotid arteries of mice were ligated and 0. 3ml blood was letted from post-eyeball venous jungle, one hour later the carotid arteries were loosed. After cerebral ischemia-reperfusion,展开更多
Melatonin, the principal secretory product of the pineal gland, functions as a potent antioxidant and free radical scavenger. Additionally, the antiapoptotic effect of melatonin has been observed both in vivo and in v...Melatonin, the principal secretory product of the pineal gland, functions as a potent antioxidant and free radical scavenger. Additionally, the antiapoptotic effect of melatonin has been observed both in vivo and in vitro. The aim of this study was to investigate the protective effects of melatonin against burn-induced injury in rat liver and whether these changes were associated with oxidative stress and changes in the expression of apoptosis related genes Bcl-2 and Bax. Melatonin (10 mg/kg, i.p.) was applied immediately after 30% of total body surface area (TBSA) burns of male Wistar rats. Malondialdehyde (MDA) as marker of oxidative stress and tumor necrosis factor (TNF-α) as inflammatory marker were assayed by biochemical methods. The hepatic apoptosis related genes Bcl-2 and Bax using light immunоchistochemistry were investigated, too. Hepatic TNF-α and MDA levels were increased significantly following severe burn. Thermal trauma increased the Bax expression without any changes of anti-apoptotic Bcl-2 protein in sinusoidal endothelial cells (SECs) of burn-treated animals compared with the control group animals as well as elevated ratio Bax/Bcl-2 suggesting the susceptibility of these cells to apoptosis. Melatonin significantly decreased the MDA and TNF-α levels in the liver tissue. It decreased also expression of Bax, increased expression of Bcl-2 and reduced Bax/Bcl-2 ratio. In conclusion, experimental data show that melatonin modulates the expression of Bcl-2 family proteins by increasing anti-apoptotic Bcl-2, inhibits apoptosis and restricts the burn-induced damage.展开更多
To study the effects of low dose radiation (LDR) on tumor apoptosis, cellcycle progression and changes of apoptosis-related protein Bcl-2 in tumor-bearing mice. Methods:Male mice of Kunming strain were implanted subcu...To study the effects of low dose radiation (LDR) on tumor apoptosis, cellcycle progression and changes of apoptosis-related protein Bcl-2 in tumor-bearing mice. Methods:Male mice of Kunming strain were implanted subcutaneously with S180 sarcoma cells in the left inguenas an in situ experimental animal model. Seven days later, the mice were subjected to 75 mGywhole-body γ-irradiation. At 24 and 48 h after the irradiation, all mice were sacrificed. The tumorsizes were measured, and tumor cell apoptosis and cell cycle progression were analyzed by flowcytometry. The expression of apoptosis-related protein Bcl-2 and the apoptotic rate of tumor cellswere observed by immunohistochemistry and electron microscopy. Results: Tumors grew significantlyslower after LDR (P 【 0.05). The tumor cells were arrested in G1 phrase and the expression of Bcl-2protein decreased at 24 h. Apoptotic rate of tumor cells was increased significantly at 48 h afterLDR (P 【 0.01). Conclusion: LDR could cause a G1-phase arrest and increase the apoptosis of tumorcells through the low level of apoptosis-related protein bcl-2 in the tumor-bearing mice. Theorganized immune function and anti-tumor ability are markedly increased after LDR. Our studyprovides practical evidence of clinical application to cancer treatment.展开更多
文摘AIM: To analyze the protein expression essential for apoptosis in liver steatosis. METHODS: The expression of proapoptotic proteins p53, Bax, and antiapoptotic Bcl-2 in hepatocytes with steatosis (SH) and without steatosis (NSH) was evaluated in 84 patients at various stages of non-alcoholic fatty liver disease (NAFLD). RESULTS: Immunohistochemical staining of liver tissue showed the activation of p53 protein in SH and NSH with increased liver steatosis, diminished Bcl-2 and slightly decreased Bax protein. Positive correlation was found between the stage of liver steatosis with p53 expression in SH (r = 0.54, P < 0.01) and NSH (r = 0.49, P < 0.01). The antiapoptotic protein Bcl-2 was diminished together with the advancement of liver steatosis, especially in non-steatosed hepatocytes (r =0.43, P < 001). CONCLUSION: Apoptosis is one of the most important mechanisms leading to hepatocyte elimination in NAFLD. The intensification of inflammation in NAFLD induces proapoptotic protein p53 with the inhibition of antiapoptotic Bcl-2.
文摘The fresh water polyp Hydra belongs to the phylum Cnidaria, which diverged from the metazoan lineage before the appearance of bilaterians. In order to understand the evolution of apoptosis in metazoans, we have begun to elucidate the molecular cell death machinery in this model organism. Based on ESTs and the whole Hydra genome assembly, we have identified 15 caspases. We show that one is activated during apoptosis, four have characteristics of initiator caspases with N-terminal DED, CARD or DD domain and two undergo autoprocessing in vitro. In addition, we describe seven Bcl-2-1ike and two Bak-like proteins. For most of the Bcl-2 family proteins, we have observed mitochondrial localization. When expressed in mammalian cells, HyBak-like 1 and 2 strongly induced apoptosis. Six of the Bcl-2 family members inhibited apoptosis induced by camptothecin in mammalian ceils with HyBcl-2-1ike 4 showing an especially strong protective effect. This protein also interacted with HyBak-like 1 in a yeast two-hybrid assay. Mutation of the conserved leucine in its BH3 domain abolished both the interaction with HyBak-like 1 and the anti-apoptotic effect. Moreover, we describe novel Hydra BH-3-only proteins. One of these interacted with Bcl-2-1ike 4 and induced apoptosis in mammalian cells. Our data indicate that the evolution of a complex network for cell death regulation arose at the earliest and simplest level of multicellular organization, where it exhibited a substantially higher level of complexity than in the protostome model organisms Caenorhabditis and Drosophila.
基金financially supported by Postdoctoral Applied Research Project of Qingdao(No.861605040085,to CZ,SW)Grant of Innovation Plan in Biomedical Research of Qingdao City(No.15-10-3-15-(28)-zch,to SW)
文摘The BH3 mimetics targeting the interaction between the BH3-only proteins and their prosurvival Bcl-2family proteins have shown enormous potential as cancer therapeutics. Herein, seven analogues targeting anti-apoptotic Bcl-2 proteins derived from the Bim BH3 domain via sequence simplification and/or modification are described. The in vitro binding affinity on anti-apoptotic Bcl-2 proteins and cell killing activity were evaluated. The results showed that analogues could significantly bind to target proteins and exhibited anti-cancer effect against three cancer cell lines. Of particular interest were the analogue SM-5(KD= 9.48 nmol/L for Bcl-2) and SM-6(KD= 0.08 nmol/L for Bcl-xL), which exhibited improved binding affinity compared with the lead Bim(KD= 16.90 nmol/L for Bcl-2 and 22.2 nmol/L for Bcl-xL, respectively). These results indicated that the peptide sequence containing the four hydrophobic side chains occupying pockets within the BH3-recognition cleft of anti-apoptotic Bcl-2 proteins might be the minimum sequence required for the bioactivity and the active core region of Bim. Promising inhibitors of anti-apoptotic Bcl-2 proteins with high bioactivity might be designed based on the active core.
基金supported by the Major Project of Science and Technology Department of Yunnan Province (202002AA100005 and 202102AE090027-2)the Project of Yunnan Province Food and Drug Homologous Resources Functional Food Innovation Team (A3032023057)+2 种基金the YEFICRC project of Yunnan provincial key programs (2019ZG009)Yunnan Province Ten Thousand Plan Industrial Technology Talents project (YNWR-CYJS-2020-010)the Yunnan Provincial Department of Science and Technology Agricultural Joint Special Project (202101BD070001-120)。
文摘Walnut dreg protein hydrolysates(WDPHs)exhibit a variety of biological activities,however,the cyclooxygenase-2(COX-2)inhibitory peptide of WDPHs remain unclear.The aim of this study was to rapidly screen for such peptides in WDPHs through a combination of in silico and in vitro analysis.In total,1262 peptide sequences were observed by nano liquid chromatography/tandem mass spectrometry(nano LC-MS/MS)and 4 novel COX-2 inhibitory peptides(AGFP,FPGA,LFPD,and VGFP)were identified.Enzyme kinetic data indicated that AGFP,FPGA,and LFPD displayed mixed-type COX-2 inhibition,whereas VGFP was a non-competitive inhibitor.This is mainly because the peptides form hydrogen bonds and hydrophobic interactions with residues in the COX-2 active site.These results demonstrate that computer analysis combined with in vitro evaluation allows for rapid screening of COX-2 inhibitory peptides in walnut protein dregs.
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.
文摘AIM To study the expression of Fas and Bcl 2 proteins in BEL 7404 human hepatoma cells in order to analyze the possible relationship between cell growth regulation by alpha fetoprotein(AFP) and Fas/Bcl 2 proteins. METHODS BEL 7404 human hepatoma cells were maintained in RPMI 1640 medium supplemented with 10% new born calf serum. Cells adhered to coverslips were used to detect Fas and Bcl 2 protein expression by the avidin biotin complex (ABC) immunocytochemical assay. RESULTS Immunocytochemical study showed that essentially all the BEL 7404 human hepatoma cells could express Fas and Bcl 2 proteins, although in various amounts. No positive staining for Fas and Bcl 2 proteins was observed when cells were incubated with non relevant sera to establish the specificity. CONCLUSION Fas apoptosis signals and Bcl 2 rescue/survival signals from apoptosis are expressed in BEL 7404 human hepatoma cells. The finding strongly implys that AFP mediated cell apoptosis and growth enhancement are potentially associated with Fas and Bcl 2 proteins present in those cells.
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Summary: Whether conventional hypothermic CPB induces myocyte apoptosis in dog hearts and modulation of bcl-2, bcl-xl, bax, bad, and caspase-3 pathways in this setting was investigated. Ten healthy adult dogs were randomized into sham-operated and CPB groups. Samples of left ventricle were obtained before, during and 3 h after CPB. In situ TUNEL was used to detect apoptotic myocytes. Immunohistochemistry and flow cytometry were employed for detection of expressions of bcl-2, bcl-xl, bax and bad proteins. Z-DEVD-AMC substrate cleavage and TBARS methods were used to measure the activity of caspase-3 and the content of lipid peroxide in LV myocardium, respectively. After CPB, the number of apoptotic myocytes in CPB group was significantly increased. The results of immunohistichemistry demonstrated that bcl-2, bcl-xl, bax and bad proteins were constitutionally present on the sarcolemma of the LV myocytes. FACS results showed that, after CPB, expressions of bax and bad in CPB group were significantly upregulated, while the expressions of bcl-2 and bcl-xl were not significantly changed in both groups. The activity of caspase-3 and the content of lipid peroxide in LV myocardium in CPB group were also significantly increased after CPB. The present study shows that there exists myocardiocyte apoptosis in dog hearts undergoing conventional hypothermic CPB and the myocyte apoptosis is initiated by ischemia and performed during reperfusion. Moreover, the CPB-induced myocyte apoptosis was associated with upregulation of expressions of bax and bad proteins, activation of caspase-3 and increase of oxidative stress.
文摘Commitment of cells to apoptosis is governed largely by protein-protein interactions between members of the Bcl-2 protein family. Its three sub-families have distinct roles: the BH3-only proteins trigger apoptosis by binding via their BH3 domain to pro-survival relatives, while the pro-apoptotic Bax and Bak have an essential downstream role involving disruption of organellar membranes and induction of caspase activation. The BH3-only proteins act as damage sensors, held inert until their activation by stress signals. Once activated, they were thought to bind promiscuously to pro-survival protein targets but unexpected selectivity has recently emerged from analysis of their interactions. Some BH3-only proteins also bind to Bax and Bak. Whether Bax and Bak are activated directly by these BH3-only proteins, or indirectly as a consequence of BH3-only proteins neutralizing their pro-survival targets is the subject of intense debate. Regardless of this, a detailed understanding of the interactions between family members, which are often selective, has notable implications for designing anti-cancer drugs to target the Bcl-2 family.
基金ThisprojectwasgrantedbyUnit"95"Foundation (No .98Q0 86)andNational" 973"FoundationofChina (No .1 9990 542 0 4 )
文摘Objective: To study the relationship between the expression of Bax, Bcl 2 proteins, and apoptosis in radiation compound wound healing of rats. Methods: Apoptosis, Bax and Bcl 2 proteins were estimated by in situ terminal labeling (TUNEL) and immunohistochemical methods. Results: (1) Changes of the apoptosis in wound healing showed three typical characteristics: early occurrence, high frequency and delayed disappearance after radiation to rats when compared with those of simple wound group, which might be an important reason for radiation induced delayed wound healing. (2) The expression of Bax protein increased evidently with the increment of apoptosis and showed a good corresponding relationship with the apoptotic frequency in the process of wound healing. While the expression of Bcl 2 protein decreased obviously as the apoptosis reached a maximum and showed increasing tendency up to normal level when the apoptosis decreased distinctively. Conclusions: Bax and Bcl 2 proteins play an important role in the apoptotic regulation of radiation compound wound healing in rats.
基金supported by Hunan Provincial Traditional Medicine Administration Bureau,No.2010044
文摘Genistein is one of several isoflavones that has a structure similar to 17β-estradiol, has a strong antioxidant effect, and a high affinity to estrogen receptors. At 15 weeks after ovariectomy, the expression of Bcl-2 in the hippocampus of rats decreased and Bax expression increased, with an obvious upregulation of apoptosis. However, intraperitoneal injection of genistein or 17β-estradiol for 15 consecutive weeks from the second day after operation upregulated Bcl-2 protein expression downregulated Bax protein expression, and attenuated hippocampal neuron apoptosis. Our experimental findings indicate that long-term intervention with genistein can lead to a decrease in apoptosis in hippocampal neurons following ovadectomy, upregulate the expression of Bcl-2, and downregulate the expression of Bax. In addition, genistein and 17β-estradiol play equal anti-apoptotic and neuroprotective roles.
文摘Objective To investigate the variance of expression of bcl-2 and bax genes in the genesis or gastric carcinoma as well as their relationship. Methods Thirty-five cases of early-stage gastric carcinoma and Twenty-four cases ot chronic atrophic gastritis were studied by immunohistochemical method. Results There were no statistical differences of bcl-2 expression levels between gastric carcinoma and atypical hyperplasia or paracancerous intestinal- epithelial metaplasia(IEM) (P>0.05).There were statistical differences of bcl-2 expression between normal epithe- lial tissues (or non-cancerous IEM) and the other three groups(P<0.05), but no statistical difference between the normal epithelial and the non-cancerous IEM group was observed(P>0.05). The expressions or bax protein were found in the normal epithelial and the other groups in varying degrees,but there were no statistical differences be- tween either two of the groups (P>0.05). The bcl-2/bax ratio was higher in early-stage gastric carcinoma,atypical hy- perplasia and paracancerous intestinal-metaplasia than in the non-cancerous intestinal-metaplasia (P<0.05) and nor- mal epithelial tissues(P<0.01). Conclusion The abnormal expression of bcl-2 protein and bax protein,especially the increased bcl-2/bax ratio, probably play an important role in the course of carcinogenesis or gastric carcinoma.
文摘AIM : To study the effects of PAMd ( Phenolic alkaloids from Menispermum dauricum on Brain ischemia and ischemic reperfusion injury in mice. METHODS : Bilateral carotid arteries of mice were ligated and 0. 3ml blood was letted from post-eyeball venous jungle, one hour later the carotid arteries were loosed. After cerebral ischemia-reperfusion,
文摘Melatonin, the principal secretory product of the pineal gland, functions as a potent antioxidant and free radical scavenger. Additionally, the antiapoptotic effect of melatonin has been observed both in vivo and in vitro. The aim of this study was to investigate the protective effects of melatonin against burn-induced injury in rat liver and whether these changes were associated with oxidative stress and changes in the expression of apoptosis related genes Bcl-2 and Bax. Melatonin (10 mg/kg, i.p.) was applied immediately after 30% of total body surface area (TBSA) burns of male Wistar rats. Malondialdehyde (MDA) as marker of oxidative stress and tumor necrosis factor (TNF-α) as inflammatory marker were assayed by biochemical methods. The hepatic apoptosis related genes Bcl-2 and Bax using light immunоchistochemistry were investigated, too. Hepatic TNF-α and MDA levels were increased significantly following severe burn. Thermal trauma increased the Bax expression without any changes of anti-apoptotic Bcl-2 protein in sinusoidal endothelial cells (SECs) of burn-treated animals compared with the control group animals as well as elevated ratio Bax/Bcl-2 suggesting the susceptibility of these cells to apoptosis. Melatonin significantly decreased the MDA and TNF-α levels in the liver tissue. It decreased also expression of Bax, increased expression of Bcl-2 and reduced Bax/Bcl-2 ratio. In conclusion, experimental data show that melatonin modulates the expression of Bcl-2 family proteins by increasing anti-apoptotic Bcl-2, inhibits apoptosis and restricts the burn-induced damage.
文摘To study the effects of low dose radiation (LDR) on tumor apoptosis, cellcycle progression and changes of apoptosis-related protein Bcl-2 in tumor-bearing mice. Methods:Male mice of Kunming strain were implanted subcutaneously with S180 sarcoma cells in the left inguenas an in situ experimental animal model. Seven days later, the mice were subjected to 75 mGywhole-body γ-irradiation. At 24 and 48 h after the irradiation, all mice were sacrificed. The tumorsizes were measured, and tumor cell apoptosis and cell cycle progression were analyzed by flowcytometry. The expression of apoptosis-related protein Bcl-2 and the apoptotic rate of tumor cellswere observed by immunohistochemistry and electron microscopy. Results: Tumors grew significantlyslower after LDR (P 【 0.05). The tumor cells were arrested in G1 phrase and the expression of Bcl-2protein decreased at 24 h. Apoptotic rate of tumor cells was increased significantly at 48 h afterLDR (P 【 0.01). Conclusion: LDR could cause a G1-phase arrest and increase the apoptosis of tumorcells through the low level of apoptosis-related protein bcl-2 in the tumor-bearing mice. Theorganized immune function and anti-tumor ability are markedly increased after LDR. Our studyprovides practical evidence of clinical application to cancer treatment.