AIM: Retention and accumulation of toxic hydrophobic bile salts within hepatocyte may cause hepatocyte toxicity by inducing apoptosis. Apoptosis is a pathway of cell death orchestrated by a family of proteases called ...AIM: Retention and accumulation of toxic hydrophobic bile salts within hepatocyte may cause hepatocyte toxicity by inducing apoptosis. Apoptosis is a pathway of cell death orchestrated by a family of proteases called caspases. Z-ValAla-Asp (OMe)-fluoromethyl ketone (ZVAD-fmk) is a cellpermeable irreversible inhibitor of caspase. The purpose of this study was to evaluate the possible effect of ZVAD-fmk on hepatocyte apoptosis after bile duct ligation in the rat.METHODS: Male Sprague-Dawley rats, weighing 250-300 g,were randomized to five groups of five rats each. Group 1 underwent common bile duct ligation and simultaneous treatment with ZVAD-fmk (dissolved in dimethylsulfoxide (DMSO)). Group 2 underwent common bile duct ligation and simultaneous treatment with Z-Phe-Ala-fluoromethyl ketone ( ZFA-fmk, dissolved in DMSO). Group 3 underwent sham operation and simultaneous treatment with the same amount of DMSO. Group 4 underwent sham operation and simultaneous treatment with the same amount of normal saline. Group 5 underwent common bile duct ligation without other manipulation. After three days, liver tissue was harvested for histopathologic analysis and measurements of apoptosis.RESULTS: When compared with sham operation, common bile duct ligation significantly increased hepatocyte apoptosis (P= 0.008) and ductular proliferation (P= 0.007).ZVAD-fmk significantly diminished the increased hepatocyte apoptosis and ductular proliferation after common bile duct ligation (P = 0.008 and P = 0.007, respectively). ZFA did not show the same effects.CONCLUSION: Hepatocyte apoptosis and ductular proliferation significantly increased after common bile duct ligation. ZVAD-fmk effectively diminished the increased hepatocyte apoptosis and ductular proliferation after common bile duct ligation, whereas ZFA-fmk did not.展开更多
Emerging evidence that Enterovirus A 71(EV-A71)infection closely related to apoptosis.The ZVAD is a caspase inhibitor that can prevent apoptosis.The aims of this project were to evaluate the mechanism of the ZVAD inhi...Emerging evidence that Enterovirus A 71(EV-A71)infection closely related to apoptosis.The ZVAD is a caspase inhibitor that can prevent apoptosis.The aims of this project were to evaluate the mechanism of the ZVAD inhibited EV-A71 virus and to provide experiment basis for finding new antiviral drugs.In this study,after treated with ZVAD in EV-A71 infected Vero cells,the viral replication was reduced,and the cell viability was higher than EV-A71 group.Additionally,ZVAD decreased the cell apoptosis and the level of inflammatory cytokines induced by EV-A71 in the infected Vero cells.ZVAD inhibited cell apoptosis by regulating ROS mediated signaling pathway and inflammation cytokines to achieve antiviral.展开更多
Metaphase-arrest agents and hyperthermia are both known to be capable of inducing apoptosis, and they have been used, separately, in cancer treatments. Here, we have examined whether the two treatments together may ha...Metaphase-arrest agents and hyperthermia are both known to be capable of inducing apoptosis, and they have been used, separately, in cancer treatments. Here, we have examined whether the two treatments together may have a synergistic effect. We find that when H-HeLa cells are arrested in metaphase with spindle poisons (nocodazole or paclitaxel) and then subjected to mild heat treatment (41.5℃), they exhibit morphological changes typical of apoptosis within three hours. Moreover, those changes are blocked by the pan-caspase inhibitor zVAD-fmk, indicating apoptosis, and activated Procaspase 3 is detected by immunoblotting and by staining with the fluoresce-in-labelled caspase inhibitor FAM-VAD-fmk. Interphase cells treated in the same way do not under-go apoptosis, even with spindle poisons present. Induction of apoptosis is more rapid when the cells have been arrested longer in metaphase, suggesting that accumulation or depletion of some cellular component(s) during metaphase-arrest may make them more susceptible to hyperthermia. Further work is in progress to test whether other cell lines exhibit the same behavior and to learn more about the mechanism. The phenomenon is of interest because it may provide clues to how hyperthermia induces cell death and may yield novel therapeutic approaches to block or stimulate apoptosis.展开更多
基金Supported by the grant NSC 89-2314-B-182A-165 from the National Science Council of Taiwan China
文摘AIM: Retention and accumulation of toxic hydrophobic bile salts within hepatocyte may cause hepatocyte toxicity by inducing apoptosis. Apoptosis is a pathway of cell death orchestrated by a family of proteases called caspases. Z-ValAla-Asp (OMe)-fluoromethyl ketone (ZVAD-fmk) is a cellpermeable irreversible inhibitor of caspase. The purpose of this study was to evaluate the possible effect of ZVAD-fmk on hepatocyte apoptosis after bile duct ligation in the rat.METHODS: Male Sprague-Dawley rats, weighing 250-300 g,were randomized to five groups of five rats each. Group 1 underwent common bile duct ligation and simultaneous treatment with ZVAD-fmk (dissolved in dimethylsulfoxide (DMSO)). Group 2 underwent common bile duct ligation and simultaneous treatment with Z-Phe-Ala-fluoromethyl ketone ( ZFA-fmk, dissolved in DMSO). Group 3 underwent sham operation and simultaneous treatment with the same amount of DMSO. Group 4 underwent sham operation and simultaneous treatment with the same amount of normal saline. Group 5 underwent common bile duct ligation without other manipulation. After three days, liver tissue was harvested for histopathologic analysis and measurements of apoptosis.RESULTS: When compared with sham operation, common bile duct ligation significantly increased hepatocyte apoptosis (P= 0.008) and ductular proliferation (P= 0.007).ZVAD-fmk significantly diminished the increased hepatocyte apoptosis and ductular proliferation after common bile duct ligation (P = 0.008 and P = 0.007, respectively). ZFA did not show the same effects.CONCLUSION: Hepatocyte apoptosis and ductular proliferation significantly increased after common bile duct ligation. ZVAD-fmk effectively diminished the increased hepatocyte apoptosis and ductular proliferation after common bile duct ligation, whereas ZFA-fmk did not.
基金supported by the fund from Open Project of Guangdong Key Laboratory of Marine Materia Medica(LMM2020-7)the fund from Guangzhou Institute of Pediatrics/Guangzhou Women and Children’s Medical Center(Nos.Pre-NSFC-2019-016,YIP-2019-059,IP-2019-019)+3 种基金the Project of Traditional Chinese Medicine Bureau of Guangdong Province(No.20192075)the technology planning projects of Guangdong province(No.202102010202)The Guangdong Natural Science Foundation(2020A1515110648)the Open Fund of Guangdong Provincial Key Laboratory of Functional Supramolecular Coordination Materials and Applications(2020A03).
文摘Emerging evidence that Enterovirus A 71(EV-A71)infection closely related to apoptosis.The ZVAD is a caspase inhibitor that can prevent apoptosis.The aims of this project were to evaluate the mechanism of the ZVAD inhibited EV-A71 virus and to provide experiment basis for finding new antiviral drugs.In this study,after treated with ZVAD in EV-A71 infected Vero cells,the viral replication was reduced,and the cell viability was higher than EV-A71 group.Additionally,ZVAD decreased the cell apoptosis and the level of inflammatory cytokines induced by EV-A71 in the infected Vero cells.ZVAD inhibited cell apoptosis by regulating ROS mediated signaling pathway and inflammation cytokines to achieve antiviral.
文摘Metaphase-arrest agents and hyperthermia are both known to be capable of inducing apoptosis, and they have been used, separately, in cancer treatments. Here, we have examined whether the two treatments together may have a synergistic effect. We find that when H-HeLa cells are arrested in metaphase with spindle poisons (nocodazole or paclitaxel) and then subjected to mild heat treatment (41.5℃), they exhibit morphological changes typical of apoptosis within three hours. Moreover, those changes are blocked by the pan-caspase inhibitor zVAD-fmk, indicating apoptosis, and activated Procaspase 3 is detected by immunoblotting and by staining with the fluoresce-in-labelled caspase inhibitor FAM-VAD-fmk. Interphase cells treated in the same way do not under-go apoptosis, even with spindle poisons present. Induction of apoptosis is more rapid when the cells have been arrested longer in metaphase, suggesting that accumulation or depletion of some cellular component(s) during metaphase-arrest may make them more susceptible to hyperthermia. Further work is in progress to test whether other cell lines exhibit the same behavior and to learn more about the mechanism. The phenomenon is of interest because it may provide clues to how hyperthermia induces cell death and may yield novel therapeutic approaches to block or stimulate apoptosis.
