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
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 expression of bcl-2 and bax in human ameloblastoma （AB）, and investigate the role of apoptosis in genesis and development of AB and the relation of apoptosis with the clinic biological chara...Objective： To study the expression of bcl-2 and bax in human ameloblastoma （AB）, and investigate the role of apoptosis in genesis and development of AB and the relation of apoptosis with the clinic biological characteristics of AB. Methods： BCL-2 and BAX proteins were detected in 75 cases of AB （primary AB 31 cases, recurrent AB 37 cases, malignant AB 7 cases） by S-P method. Oral normal mucosa （NOM） and Odontogenic kerotosyst （OKC） were used as controls. Bcl-2 and bax mRNA in 20 cases of AB, 12 cases of OKC were detected by in situ hybridization. Results： The positive ratio of BCL-2 protein was 88.0% （66/75） in AB, 74.3% （26/35） in OKC and 44.4% （4/9） in NOM, respectively （P〈0.001）. BCL-2 protein was expressed in peripheral cells and a few scattered stellate-shape cells in AB. The positive ratio of BAX protein was 74.7% （56/75）in AB, 65.7%（23/35）in OKC and 77.8%（7/9） in NOM, respectively （P〈0.001）. BAX protein was expressed in peripheral cells and stellate-shape cells with similar intensity. BCL-2 expression increased in recurrent and AB canceration（P〈0.01）, while for BAX expression, the positive ratio was higher in recurrent AB, but lower than that of malignant AB. A moderate negative correlation between BCL-2 and BAX protein was found （rk=-0.331, P〈0.001）. Conclusion： AB has much more apoptosis-inhibiting protein than apoptosis- accelarating protein. Apoptosis plays an important role in genesis, development of AB. The fashion and intensity of bcl-2 and bax expression were different in various tissues and in benign or malignant AB.展开更多
The Bcl-2 knockout mice demonstrated fulminant lymphoid apoptosis, polycystic kidneys, hypopig-mented hair, as well as abnormalities in development, bone formation and life span (Cell 75, 229). These symptoms are typi...The Bcl-2 knockout mice demonstrated fulminant lymphoid apoptosis, polycystic kidneys, hypopig-mented hair, as well as abnormalities in development, bone formation and life span (Cell 75, 229). These symptoms are typically known as deficiency of kidneys in traditional Chinese medicine. We hypothesize that the Chinese concept of the Kidneys is related to the in vivo roles of the Bcl-2 family and the traditional Chinese herbal formulates designed for affecting the functions of the Kidneys could modulate the expression of this gene family. To test this hypothesis, the blood were collected from the volunteers before and after their taking the Jin Gui Shen Qi Wan (Jin Gui) Pills for Tonifying Kidney-energy, a classic herbal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
Hepatocellular carcinoma(HCC)is a leading cause of death worldwide.Current therapies are effective for HCC patients with early disease,but many patients suffer recurrence after surgery and have a poor response to chem...Hepatocellular carcinoma(HCC)is a leading cause of death worldwide.Current therapies are effective for HCC patients with early disease,but many patients suffer recurrence after surgery and have a poor response to chemotherapy.Therefore,new therapeutic targets are needed.We analyzed gene expression profiles between HCC tissues and normal adjacent tissues from public databases and found that the expression of genes involved in lipid metabolism was significantly different.The analysis showed that AKR1C3 was upregulated in tumors,and high AKR1C3 expression was associated with a poorer prognosis in HCC patients.In vitro,assays demonstrated that the knockdown of AKR1C3 or the addition of the AKR1C3 inhibitor indomethacin suppressed the growth and colony formation of HCC cell lines.Knockdown of AKR1C3 in Huh7 cells reduced tumor growth in vivo.To explore the mechanism,we performed pathway enrichment analysis,and the results linked the expression of AKR1C3 with prostaglandin F2 alpha(PGF2a)downstream target genes.Suppression of AKR1C3 activity reduced the production of PGF2a,and supplementation with PGF2a restored the growth of indomethacin-treated Huh7 cells.Knockdown of the PGF receptor(PTGFR)and treatment with a PTGFR inhibitor significantly reduced HCC growth.We showed that indomethacin potentiated the sensitivity of Huh7 cells to sorafenib.In summary,our results indicate that AKR1C3 upregulation may promote HCC growth by promoting the production of PGF2α,and suppression of PTGFR limited HCC growth.Therefore,targeting the AKR1C3-PGF2a-PTGFR axis may be a new strategy for the treatment of HCC.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This work was supported by the Education office of Liaoning Province(No. 20122171) and the Science Committee of Shenyang City (No. 200138-7).
文摘Objective： To study the expression of bcl-2 and bax in human ameloblastoma （AB）, and investigate the role of apoptosis in genesis and development of AB and the relation of apoptosis with the clinic biological characteristics of AB. Methods： BCL-2 and BAX proteins were detected in 75 cases of AB （primary AB 31 cases, recurrent AB 37 cases, malignant AB 7 cases） by S-P method. Oral normal mucosa （NOM） and Odontogenic kerotosyst （OKC） were used as controls. Bcl-2 and bax mRNA in 20 cases of AB, 12 cases of OKC were detected by in situ hybridization. Results： The positive ratio of BCL-2 protein was 88.0% （66/75） in AB, 74.3% （26/35） in OKC and 44.4% （4/9） in NOM, respectively （P〈0.001）. BCL-2 protein was expressed in peripheral cells and a few scattered stellate-shape cells in AB. The positive ratio of BAX protein was 74.7% （56/75）in AB, 65.7%（23/35）in OKC and 77.8%（7/9） in NOM, respectively （P〈0.001）. BAX protein was expressed in peripheral cells and stellate-shape cells with similar intensity. BCL-2 expression increased in recurrent and AB canceration（P〈0.01）, while for BAX expression, the positive ratio was higher in recurrent AB, but lower than that of malignant AB. A moderate negative correlation between BCL-2 and BAX protein was found （rk=-0.331, P〈0.001）. Conclusion： AB has much more apoptosis-inhibiting protein than apoptosis- accelarating protein. Apoptosis plays an important role in genesis, development of AB. The fashion and intensity of bcl-2 and bax expression were different in various tissues and in benign or malignant AB.
基金Supported by the National Natural Science Fund of China (39900197) and Young Talent Grant ofScientific Bureau of Pudong New District, Shanghai (PK-99-13).
文摘The Bcl-2 knockout mice demonstrated fulminant lymphoid apoptosis, polycystic kidneys, hypopig-mented hair, as well as abnormalities in development, bone formation and life span (Cell 75, 229). These symptoms are typically known as deficiency of kidneys in traditional Chinese medicine. We hypothesize that the Chinese concept of the Kidneys is related to the in vivo roles of the Bcl-2 family and the traditional Chinese herbal formulates designed for affecting the functions of the Kidneys could modulate the expression of this gene family. To test this hypothesis, the blood were collected from the volunteers before and after their taking the Jin Gui Shen Qi Wan (Jin Gui) Pills for Tonifying Kidney-energy, a classic herbal
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.
基金National Yang Ming Chiao Tung University Far Eastern Memorial Hospital Joint Research Programs(NYCU-FEMH 109DN03,110DN06,111DN04,112DN05).
文摘Hepatocellular carcinoma(HCC)is a leading cause of death worldwide.Current therapies are effective for HCC patients with early disease,but many patients suffer recurrence after surgery and have a poor response to chemotherapy.Therefore,new therapeutic targets are needed.We analyzed gene expression profiles between HCC tissues and normal adjacent tissues from public databases and found that the expression of genes involved in lipid metabolism was significantly different.The analysis showed that AKR1C3 was upregulated in tumors,and high AKR1C3 expression was associated with a poorer prognosis in HCC patients.In vitro,assays demonstrated that the knockdown of AKR1C3 or the addition of the AKR1C3 inhibitor indomethacin suppressed the growth and colony formation of HCC cell lines.Knockdown of AKR1C3 in Huh7 cells reduced tumor growth in vivo.To explore the mechanism,we performed pathway enrichment analysis,and the results linked the expression of AKR1C3 with prostaglandin F2 alpha(PGF2a)downstream target genes.Suppression of AKR1C3 activity reduced the production of PGF2a,and supplementation with PGF2a restored the growth of indomethacin-treated Huh7 cells.Knockdown of the PGF receptor(PTGFR)and treatment with a PTGFR inhibitor significantly reduced HCC growth.We showed that indomethacin potentiated the sensitivity of Huh7 cells to sorafenib.In summary,our results indicate that AKR1C3 upregulation may promote HCC growth by promoting the production of PGF2α,and suppression of PTGFR limited HCC growth.Therefore,targeting the AKR1C3-PGF2a-PTGFR axis may be a new strategy for the treatment of HCC.
