AIM: To investigate the relationship between Fas gene expression and calcium influx change in peroxide-induced apoptotic hepatocytes and the possible molecular mechanism of Rxa in protecting hepatocytes.METHODS: Singl...AIM: To investigate the relationship between Fas gene expression and calcium influx change in peroxide-induced apoptotic hepatocytes and the possible molecular mechanism of Rxa in protecting hepatocytes.METHODS: Single-cell Fas mRNA expression in H2O2-exposed L02 hepatocytes with or without treatment of Rxa,an extract from an anti-peroxidant, Radix Salviae Miltiorrhizae,was determined by all-cell patch clamp and single-cell reverse transcriptase polymerase chain reaction (RT-PCR). Transient calcium influx change ([Ca2+]i) in the cells was evaluated with all-cell patch clamp micro-fluorescence single-cytosolic free Ca2+ concentration technique. Fas protein expression, early apoptotic index (annexin-V+) and cell membrane change inthe cells were evaluated by immunohistochemistry, flow cytometry (FCM) and scan electron microscopy respectively.RESULTS: In cells exposed to H2O2 for 2 h, the specific lane for Fas mRNA was vivid on electrophoresis, with increased Fas protein expression, [Ca2+]i (from 143.66±34.21 to 1115.28±227.16), annexin-V+ index (from 4.00±0.79 to 16.18±0.72) and membrane vesicle formation. However, in cells exposed to H2O2 but pre-treated with Rxa, there was no increase in Fas mRNA or protein expression and [Ca2+]i (103.56±28.92). Annexin-V+ index (8.92±1.44) was lower than the controls (P＜0.01), and the cell membrane was intact.CONCLUSION: H2O2 induces apoptosis of L02 cells by increasing cytosolic [Ca2+]i, and inducing Fas mRNA and protein expression. Rxa protects the L02 cells from apoptosis through anti-peroxidation, inhibition of calcium overloading and prevention of the activation of cytosolic Fas signal pathway.展开更多
Oxidative stress, owing to the excessive production of ROS （reactive oxygen species）, is one of the leading causes for the progression of AD （Alzheimer＇s disease）. Increasing evidences suggested that oxidative st...Oxidative stress, owing to the excessive production of ROS （reactive oxygen species）, is one of the leading causes for the progression of AD （Alzheimer＇s disease）. Increasing evidences suggested that oxidative stress insult impaired the physiological functioning of neuronal cells by inducing cell apoptosis. The search for drug candidates that can effectively protect neurons from oxidative stress insult might hold therapeutic potential for AD. In the present study, we tested the neuroprotective effects and the related action mechanisms of artemisinin, a FDA-approved anti-malarial drug, against H2O2 induced oxidative damage in PC12 cells. It was found that artemisinin reduced cell viability loss caused by hydrogen peroxide （H2O2） in PC12 cells. In addition, data from Flow cytometry displayed that artemisinin significantly decreased the apoptosis of PC 12 cells induced by H2O2. Furthermore Western blot analysis displayed that artemisinin stimulated the p38MAPK signaling, while treatment of PC 12 cells with specific p38MAPK pathway inhibitor SB203580 blocked the neuroprotective effect of artemisinin. These results together indicated that artemisinin is a potential protectant, and it protects PC12 cells against H2O2 injury through activation of the p38MAPK pathway.展开更多
It was reported that exogenous hydrogen peroxide （H2O2） can induce primary root bend in Arabidopsis and pea. However, the mechanism remains unclear. Here we explored the mechanism underlying this phenomenon by using...It was reported that exogenous hydrogen peroxide （H2O2） can induce primary root bend in Arabidopsis and pea. However, the mechanism remains unclear. Here we explored the mechanism underlying this phenomenon by using the pea （Pisum sativum L.） variety ＂longwan No. 1＂ The results showed that the endogenous indole-3-acetic acid （IAA） content decreased and gibberellin A3 （GA3） content increased in the curving primary pea root induced by H2O2. Meanwhile, both of the two hormones asymmetrically distributed in the inside and outside parts of the curving root. Also, the starch content decreased due to the increased a-amylase activity in this process. However, exogenous Ca2＋ can relieve the horizontal bending of pea root induced by H2O2 and altered the contents of endogenous IAA and GA3. A working model was proposed： Exogenous H2O2 causes the increase in GA3 content, and GA3 stimulates the activity of or-amylase, which leads to the hydrolysis of starch, and then the root lost the gravity perceiving. The asymmetric distribution of IAA and GA3 in two sides of curving root may cause the horizontal bending.Exogenous Ca^2＋ can relieve root bending through altering the endogenous IAA and GA3 contents.展开更多
基金Supported by National Natural Science Fundation of China, No.39770938Whole Army Medical Scientific Research Task during the Fifteen the Five-year Plan, No. 01MA040
文摘AIM: To investigate the relationship between Fas gene expression and calcium influx change in peroxide-induced apoptotic hepatocytes and the possible molecular mechanism of Rxa in protecting hepatocytes.METHODS: Single-cell Fas mRNA expression in H2O2-exposed L02 hepatocytes with or without treatment of Rxa,an extract from an anti-peroxidant, Radix Salviae Miltiorrhizae,was determined by all-cell patch clamp and single-cell reverse transcriptase polymerase chain reaction (RT-PCR). Transient calcium influx change ([Ca2+]i) in the cells was evaluated with all-cell patch clamp micro-fluorescence single-cytosolic free Ca2+ concentration technique. Fas protein expression, early apoptotic index (annexin-V+) and cell membrane change inthe cells were evaluated by immunohistochemistry, flow cytometry (FCM) and scan electron microscopy respectively.RESULTS: In cells exposed to H2O2 for 2 h, the specific lane for Fas mRNA was vivid on electrophoresis, with increased Fas protein expression, [Ca2+]i (from 143.66±34.21 to 1115.28±227.16), annexin-V+ index (from 4.00±0.79 to 16.18±0.72) and membrane vesicle formation. However, in cells exposed to H2O2 but pre-treated with Rxa, there was no increase in Fas mRNA or protein expression and [Ca2+]i (103.56±28.92). Annexin-V+ index (8.92±1.44) was lower than the controls (P＜0.01), and the cell membrane was intact.CONCLUSION: H2O2 induces apoptosis of L02 cells by increasing cytosolic [Ca2+]i, and inducing Fas mRNA and protein expression. Rxa protects the L02 cells from apoptosis through anti-peroxidation, inhibition of calcium overloading and prevention of the activation of cytosolic Fas signal pathway.
基金Acknowledgements This research was financially supported by the National Natural Science Foundation of China （31371088） the Guangdong Provincial Project of Science and Technology （2011B050200005） SRG2015-00004-FHS and MYRG2016-00052-FHS from University of Macao, and the Science and Technology Development Fund （FDCT） of Macao （FDCT 021/2015/A1 and FDCT016/2016/A1）.
文摘Oxidative stress, owing to the excessive production of ROS （reactive oxygen species）, is one of the leading causes for the progression of AD （Alzheimer＇s disease）. Increasing evidences suggested that oxidative stress insult impaired the physiological functioning of neuronal cells by inducing cell apoptosis. The search for drug candidates that can effectively protect neurons from oxidative stress insult might hold therapeutic potential for AD. In the present study, we tested the neuroprotective effects and the related action mechanisms of artemisinin, a FDA-approved anti-malarial drug, against H2O2 induced oxidative damage in PC12 cells. It was found that artemisinin reduced cell viability loss caused by hydrogen peroxide （H2O2） in PC12 cells. In addition, data from Flow cytometry displayed that artemisinin significantly decreased the apoptosis of PC 12 cells induced by H2O2. Furthermore Western blot analysis displayed that artemisinin stimulated the p38MAPK signaling, while treatment of PC 12 cells with specific p38MAPK pathway inhibitor SB203580 blocked the neuroprotective effect of artemisinin. These results together indicated that artemisinin is a potential protectant, and it protects PC12 cells against H2O2 injury through activation of the p38MAPK pathway.
基金supported by the National Natural Science Foundation of China(31160304)Gansu Provincial Key Laboratory of Aridland Crop Science,Gansu Agricultural University,China
文摘It was reported that exogenous hydrogen peroxide （H2O2） can induce primary root bend in Arabidopsis and pea. However, the mechanism remains unclear. Here we explored the mechanism underlying this phenomenon by using the pea （Pisum sativum L.） variety ＂longwan No. 1＂ The results showed that the endogenous indole-3-acetic acid （IAA） content decreased and gibberellin A3 （GA3） content increased in the curving primary pea root induced by H2O2. Meanwhile, both of the two hormones asymmetrically distributed in the inside and outside parts of the curving root. Also, the starch content decreased due to the increased a-amylase activity in this process. However, exogenous Ca2＋ can relieve the horizontal bending of pea root induced by H2O2 and altered the contents of endogenous IAA and GA3. A working model was proposed： Exogenous H2O2 causes the increase in GA3 content, and GA3 stimulates the activity of or-amylase, which leads to the hydrolysis of starch, and then the root lost the gravity perceiving. The asymmetric distribution of IAA and GA3 in two sides of curving root may cause the horizontal bending.Exogenous Ca^2＋ can relieve root bending through altering the endogenous IAA and GA3 contents.
