The proinflammatory cytokine tumor necrosis factor-α (TNF-α) regulates immune responses, inflammation and programmed cell death. The ultimate fate of a cell exposed to TNF-αis determined by signal integration betwe...The proinflammatory cytokine tumor necrosis factor-α (TNF-α) regulates immune responses, inflammation and programmed cell death. The ultimate fate of a cell exposed to TNF-αis determined by signal integration between its downstream effectors, including caspases, IKB kianse (IKK) and c-Jun N-terminal protein kinase (JNK). However, the molecular mechanisms are incompletely understood. We investigated this issue using genetic and biochemical approaches. We identified IKK β, a catalytic subunit of the IKK complex that is required for NF-KB activation and cell survival in response to TNF-α, was proteolyzed by casp-3-related caspases. This proteolysis eliminated IKK activity and promoted TNF-α, killing.展开更多
Objective: To investigate the correlation between JNK signal and the apoptosis of VSMC as well as the expression of Cathepsin B and to explore the role of JNK signal in the development of cerebral aneurysm. Methods: R...Objective: To investigate the correlation between JNK signal and the apoptosis of VSMC as well as the expression of Cathepsin B and to explore the role of JNK signal in the development of cerebral aneurysm. Methods: Rat models of cerebral aneurysm were established and histopathologic changes of cerebral aneurysm and the apoptosis of VSMC were analyzed. Rat models were respectively subject to subcutaneous injection of Cathepsin B si RNA and JNK inhibitor SP600125. Western blot technique was used to detect the expression of proteins like Cathepsin B, Caspase-3, and p-JNK. Spearman's rho was used to examine the correlation between p-JNK and Cathepsin B, as well as the expression of relevant proteins. Results:The success rate of modeling rats with cerebral aneurysm was 88.75%. After the respective injection of Cathepsin B si RNA, SP600125 and their combination, the cell densities of VSMC of rats with cerebral aneurysm all increased significantly(P<0.05 or P<0.01), but the apoptosis rate of VSMC decreased significantly(P<0.01). Compared with normal rats, the expression of Cathepsin B, Caspase-3 and p-JNK in cerebral aneurysm models increased significantly. Effectively intervening Cathepsin B genes with Cathepsin B si RNA could significantly inhibit the expression of Cathepsin B and Caspase-3, but hardly influence the expression of p-JNK. JNK inhibitor SP600125 had no influence on the expression of Cathepsin B and Caspase-3, but effectively inhibited the expression of p-JNK. In cerebral aneurysm tissues, positive correlation was observed between the expression of p-JNK and Cathepsin B, the correlation coefficient was r=0.640. Conclusion: After the attack of cerebral aneurysm, proteins like Cathepsin B, Caspase-3 and p-JNK are all involved in the apoptosis of VSMCs. This process may be realized by Cathepsin B which activates the apoptosis mechanism of Caspase-3 and mediate the apoptosis of VSMC through the JNK signaling pathway. Therefore, silencing Cathepsin B gene or inhibiting the conduction through JNK signaling pathway can mitigate the apoptosis of vascular smooth muscle cells in cerebral aneurysm.展开更多
Aim Alpha7 nicotinic acetylcholine receptor （α7nAChR）, a subtype of nAChR regulating neurotrans- mission in central nervous system, is an essential regulator of cholinergic antiinflammatory pathway in periphery. Th...Aim Alpha7 nicotinic acetylcholine receptor （α7nAChR）, a subtype of nAChR regulating neurotrans- mission in central nervous system, is an essential regulator of cholinergic antiinflammatory pathway in periphery. The present study was to determine the effects of activation of α7nAChR on oxidant stress-induced injury in endo- thelial cells. Methods Cultured human umbilical vein endothelial cells were treated with H202 （400 μmol · L^-1） or H202plus PNU-282987 （ 10 μmol · L^-1 ）. Cell viability and membrane integrity were measured. AnnexinV ＋ PI assay, immunoblotting of bcl-2, bax and cleaved caspase-3, and immunofluorescence of apoptosis inducing factor （AIF） were performed to evaluate apoptosis. Protein expression of vascular peroxidase-1 （ VPO-1 ） and phosphor- JNK were measured by immunoblotting. Results Activation of α7nAChR by a selective agonist PNU-282987 pre-vented H202-indced decrease of cell viability and increase of lactate dehydrogenase release. Activation of α7nAChR markedly reduced cell apoptosis and intracellular oxidative stress level. Moreover, activation of α7nAChR reduced H2 02 -induced VPO-1 protein upregulation and JNK1/2 phosphorylation. The inhibitory effect of α7nAChR activa- tion on VPO-1 was blocked by JNK inhibitor SP600125. In addition, pretreatment of α7nAChR antagonist methyl- lycaconitine blocked the cytoprotective effect of PNU-282987. Conclusion These results provide the first evidence that activation of α7nAChR protects against oxidant stress-induced damage by suppressing VPO-1 in a JNK signa- ling pathway-dependent manner in endothelial cells.展开更多
Objective:To investigate the effects of butylphthalide on reducing neuronal apoptosis in rats with cerebral infarction by inhibiting the JNK/P38 MAPK signaling pathway.Methods:Forty-eight SD male rats were divided int...Objective:To investigate the effects of butylphthalide on reducing neuronal apoptosis in rats with cerebral infarction by inhibiting the JNK/P38 MAPK signaling pathway.Methods:Forty-eight SD male rats were divided into DZ group(control group),CI group(model group)and NBP group(butylphthalide group).Rats in CI group and NBP group were used to establish cerebral infarction models.NBP group used NBP.The solution(80 mg/(kg?d))was administered orally,and the remaining two groups were administered with the same volume of peanut oil.After 14 consecutive days of treatment,the Zea Longa score was used to evaluate the neurological function of DZ,CI and NBP rats.Scoring,TTC staining was used to observe the cerebral infarction volume of rats in DZ group,CI group and NBP group,HE staining was used to observe the pathological morphology of brain tissue in DZ group,CI group and NBP group.Neuronal apoptosis,Western blot was used to detect the expression of p-JNK and p-p38MAPK in brain tissues of DZ group,CI group and NBP group.Results:The neurological function of the rats in the CI group was higher than that in the DZ group,and the difference was statistically significant(P<0.05).The neurological function score of the rats in the NBP group was reduced compared with the CI group,and the difference was statistically significant(P<0.05).The cerebral infarction volume in the group was 35.56%higher than that in the DZ group,and the difference was statistically significant(P<0.05).The minor infarct volume in the NBP group was 21.59%,which was less than that in the CI group,and the difference was statistically significant(P<0.05).Nerve cells are neatly sorted,with a large number.The gap between blood vessels and interstitial tissue in the CI group is enlarged,the cells are severely contracted,and the neuron structure is incomplete.Compared with the CI group,the NBP group has reduced neuron contraction and increased number;The dead nerve cells were brown.The apoptosis rate of nerve cells in the CI group was 79.65%higher than that in the DZ group was 5.82%.The difference was statistically significant(P<0.05).The nerve cell apoptosis rate in the NBP group was 30.23%.Compared with CI group,the difference was statistically significant(P<0.05);Western blot results showed that p-JNK and p-p38MAPK protein expression in CI group was higher than that in DZ group,and the difference was statistically significant(P<0.05).The levels of p-JNK and p-p38MAPK proteins in the NBP group were lower than those in the CI group.There was statistically significant(P<0.05).Conclusion:Butylphthalide can improve neurological damage,reduce apoptotic nerve cells,and reduce infarct volume in rats with cerebral infarction,which is related to the inhibition of JNK/P38 MAPK pathway expression.展开更多
Ligands for macrophage scavenger receptors are reported to induce a wide range of host cell responses, including the production of inflammatory cytokines;however, the underlying mechanisms have not yet been fully unde...Ligands for macrophage scavenger receptors are reported to induce a wide range of host cell responses, including the production of inflammatory cytokines;however, the underlying mechanisms have not yet been fully understood and which remain obscure. In this study, we have examined the effect of maleylated bovine serum albumin (maleylated-BSA), a well-known ligand of the scavenger receptor, on the murine macrophage cell line RAW264.7. Maleylated-BSA strongly induced the production of tumor necrosis factor-α (TNF-α) and induced phosphorylation of extracellular signal-regulated kinase (ERK) and NF-kB p65. We also observed that maleylated-BSA-induced TNF-α production was blocked by the ERK inhibitor U0126. Together, these data demonstrates that maleylated-BSA- induced production of TNF-α requires the ERK/NF-κB signaling cascade in murine RAW- 264.7 macrophages.展开更多
文摘The proinflammatory cytokine tumor necrosis factor-α (TNF-α) regulates immune responses, inflammation and programmed cell death. The ultimate fate of a cell exposed to TNF-αis determined by signal integration between its downstream effectors, including caspases, IKB kianse (IKK) and c-Jun N-terminal protein kinase (JNK). However, the molecular mechanisms are incompletely understood. We investigated this issue using genetic and biochemical approaches. We identified IKK β, a catalytic subunit of the IKK complex that is required for NF-KB activation and cell survival in response to TNF-α, was proteolyzed by casp-3-related caspases. This proteolysis eliminated IKK activity and promoted TNF-α, killing.
基金supported by The Scientific and Technological Research Key Project of the Education Department of Henan Province(grant No.14A320037)
文摘Objective: To investigate the correlation between JNK signal and the apoptosis of VSMC as well as the expression of Cathepsin B and to explore the role of JNK signal in the development of cerebral aneurysm. Methods: Rat models of cerebral aneurysm were established and histopathologic changes of cerebral aneurysm and the apoptosis of VSMC were analyzed. Rat models were respectively subject to subcutaneous injection of Cathepsin B si RNA and JNK inhibitor SP600125. Western blot technique was used to detect the expression of proteins like Cathepsin B, Caspase-3, and p-JNK. Spearman's rho was used to examine the correlation between p-JNK and Cathepsin B, as well as the expression of relevant proteins. Results:The success rate of modeling rats with cerebral aneurysm was 88.75%. After the respective injection of Cathepsin B si RNA, SP600125 and their combination, the cell densities of VSMC of rats with cerebral aneurysm all increased significantly(P<0.05 or P<0.01), but the apoptosis rate of VSMC decreased significantly(P<0.01). Compared with normal rats, the expression of Cathepsin B, Caspase-3 and p-JNK in cerebral aneurysm models increased significantly. Effectively intervening Cathepsin B genes with Cathepsin B si RNA could significantly inhibit the expression of Cathepsin B and Caspase-3, but hardly influence the expression of p-JNK. JNK inhibitor SP600125 had no influence on the expression of Cathepsin B and Caspase-3, but effectively inhibited the expression of p-JNK. In cerebral aneurysm tissues, positive correlation was observed between the expression of p-JNK and Cathepsin B, the correlation coefficient was r=0.640. Conclusion: After the attack of cerebral aneurysm, proteins like Cathepsin B, Caspase-3 and p-JNK are all involved in the apoptosis of VSMCs. This process may be realized by Cathepsin B which activates the apoptosis mechanism of Caspase-3 and mediate the apoptosis of VSMC through the JNK signaling pathway. Therefore, silencing Cathepsin B gene or inhibiting the conduction through JNK signaling pathway can mitigate the apoptosis of vascular smooth muscle cells in cerebral aneurysm.
文摘Aim Alpha7 nicotinic acetylcholine receptor （α7nAChR）, a subtype of nAChR regulating neurotrans- mission in central nervous system, is an essential regulator of cholinergic antiinflammatory pathway in periphery. The present study was to determine the effects of activation of α7nAChR on oxidant stress-induced injury in endo- thelial cells. Methods Cultured human umbilical vein endothelial cells were treated with H202 （400 μmol · L^-1） or H202plus PNU-282987 （ 10 μmol · L^-1 ）. Cell viability and membrane integrity were measured. AnnexinV ＋ PI assay, immunoblotting of bcl-2, bax and cleaved caspase-3, and immunofluorescence of apoptosis inducing factor （AIF） were performed to evaluate apoptosis. Protein expression of vascular peroxidase-1 （ VPO-1 ） and phosphor- JNK were measured by immunoblotting. Results Activation of α7nAChR by a selective agonist PNU-282987 pre-vented H202-indced decrease of cell viability and increase of lactate dehydrogenase release. Activation of α7nAChR markedly reduced cell apoptosis and intracellular oxidative stress level. Moreover, activation of α7nAChR reduced H2 02 -induced VPO-1 protein upregulation and JNK1/2 phosphorylation. The inhibitory effect of α7nAChR activa- tion on VPO-1 was blocked by JNK inhibitor SP600125. In addition, pretreatment of α7nAChR antagonist methyl- lycaconitine blocked the cytoprotective effect of PNU-282987. Conclusion These results provide the first evidence that activation of α7nAChR protects against oxidant stress-induced damage by suppressing VPO-1 in a JNK signa- ling pathway-dependent manner in endothelial cells.
基金Key research project of medical science of Hubei province
文摘Objective:To investigate the effects of butylphthalide on reducing neuronal apoptosis in rats with cerebral infarction by inhibiting the JNK/P38 MAPK signaling pathway.Methods:Forty-eight SD male rats were divided into DZ group(control group),CI group(model group)and NBP group(butylphthalide group).Rats in CI group and NBP group were used to establish cerebral infarction models.NBP group used NBP.The solution(80 mg/(kg?d))was administered orally,and the remaining two groups were administered with the same volume of peanut oil.After 14 consecutive days of treatment,the Zea Longa score was used to evaluate the neurological function of DZ,CI and NBP rats.Scoring,TTC staining was used to observe the cerebral infarction volume of rats in DZ group,CI group and NBP group,HE staining was used to observe the pathological morphology of brain tissue in DZ group,CI group and NBP group.Neuronal apoptosis,Western blot was used to detect the expression of p-JNK and p-p38MAPK in brain tissues of DZ group,CI group and NBP group.Results:The neurological function of the rats in the CI group was higher than that in the DZ group,and the difference was statistically significant(P<0.05).The neurological function score of the rats in the NBP group was reduced compared with the CI group,and the difference was statistically significant(P<0.05).The cerebral infarction volume in the group was 35.56%higher than that in the DZ group,and the difference was statistically significant(P<0.05).The minor infarct volume in the NBP group was 21.59%,which was less than that in the CI group,and the difference was statistically significant(P<0.05).Nerve cells are neatly sorted,with a large number.The gap between blood vessels and interstitial tissue in the CI group is enlarged,the cells are severely contracted,and the neuron structure is incomplete.Compared with the CI group,the NBP group has reduced neuron contraction and increased number;The dead nerve cells were brown.The apoptosis rate of nerve cells in the CI group was 79.65%higher than that in the DZ group was 5.82%.The difference was statistically significant(P<0.05).The nerve cell apoptosis rate in the NBP group was 30.23%.Compared with CI group,the difference was statistically significant(P<0.05);Western blot results showed that p-JNK and p-p38MAPK protein expression in CI group was higher than that in DZ group,and the difference was statistically significant(P<0.05).The levels of p-JNK and p-p38MAPK proteins in the NBP group were lower than those in the CI group.There was statistically significant(P<0.05).Conclusion:Butylphthalide can improve neurological damage,reduce apoptotic nerve cells,and reduce infarct volume in rats with cerebral infarction,which is related to the inhibition of JNK/P38 MAPK pathway expression.
文摘Ligands for macrophage scavenger receptors are reported to induce a wide range of host cell responses, including the production of inflammatory cytokines;however, the underlying mechanisms have not yet been fully understood and which remain obscure. In this study, we have examined the effect of maleylated bovine serum albumin (maleylated-BSA), a well-known ligand of the scavenger receptor, on the murine macrophage cell line RAW264.7. Maleylated-BSA strongly induced the production of tumor necrosis factor-α (TNF-α) and induced phosphorylation of extracellular signal-regulated kinase (ERK) and NF-kB p65. We also observed that maleylated-BSA-induced TNF-α production was blocked by the ERK inhibitor U0126. Together, these data demonstrates that maleylated-BSA- induced production of TNF-α requires the ERK/NF-κB signaling cascade in murine RAW- 264.7 macrophages.
