目的:探讨COX-2促进结直肠癌肝转移效果及其机制,从而为结直肠癌肝转移防治提供依据。方法:建立COX-2低表达和高表达CT26结肠癌细胞株,通过注射0.2 m L的对数生长期细胞浓度为1×10~6个/mL的正常CT26结肠癌细胞悬液(A组,n=20)、COX-...目的:探讨COX-2促进结直肠癌肝转移效果及其机制,从而为结直肠癌肝转移防治提供依据。方法:建立COX-2低表达和高表达CT26结肠癌细胞株,通过注射0.2 m L的对数生长期细胞浓度为1×10~6个/mL的正常CT26结肠癌细胞悬液(A组,n=20)、COX-2高表达的CT26结肠癌细胞悬液(B组,n=20)以及COX-2低表达的结肠癌细胞悬液(C组,n=20)至脾脏制作小鼠结肠癌肝转移模型,检测比较三组小鼠移植瘤COX-2、PI3K、p-Akt表达、移植瘤体积、肝脏肿瘤大小和数量以及生存期,并分析结直肠癌肝转移小鼠COX-2、PI3K、p-Akt表达的相互关系以及三者与其移植瘤体积、肝脏肿瘤大小和数量以及生存期的关系。结果:与A组比较,B组和C组移植瘤COX-2、PI3K、p-Akt蛋白检测阳性率均升高,移植瘤体积降低,肝脏肿瘤大小和数量降低,生存期延长(P<0.05)。与B组比较,C组移植瘤COX-2、PI3K、p-Akt蛋白检测阳性率均升高,移植瘤体积降低,肝脏肿瘤大小和数量降低,生存期延长(P<0.05)。Spearman相关分析结果显示,结直肠癌肝转移小鼠移植瘤COX-2蛋白表达与其PI3K、p-Akt蛋白表达呈正相关(P<0.05),且其移植瘤COX-2、PI3K、p-Akt与其移植瘤体积、肝脏肿瘤大小和数量均呈正相关(P<0.05),与其生存期均呈负相关(P<0.05)。结论:COX-2可促结直肠癌肝转移和影响其预后,在此过程中可能涉及其活化PI3K/Akt信号通路作用。展开更多
Disturbances in nitric oxide synthase (NOS) and cyclooxygenase (COX) isozyme systems, manifested by the excessive NO and prostaglandin (PGE2) generation, are well-recognized features of gastric mucosal inflammatory re...Disturbances in nitric oxide synthase (NOS) and cyclooxygenase (COX) isozyme systems, manifested by the excessive NO and prostaglandin (PGE2) generation, are well-recognized features of gastric mucosal inflammatory responses to H. pylori infection. In this study, we report that H. pylori LPS-induced enhancement in gastric mucosal inducible (i) iNOS expression and COX-2 activation was accompanied by the impairment in constitutive (c) cNOS phosphorylation, up-regulation in the inhibitory κB kinase-β (IKKβ) activation and the increase in the transcriptional factor, NF-κB, nuclear translocation. Further, we show that abrogation of cNOS control over NF-κB activation has lead to induction of iNOS expression and COX-2 activation through S-nitrosylation. Moreover, we demonstrate that the modulatory effect of peptide hormone, ghrelin, on the LPS-induced changes was reflected in the increase in Src/Akt-dependent cNOS activation through phosphorylation and the suppression of IKK-β activity through cNOS-mediated IKK-β protein S-nitrosylation. As a result, ghrelin exerted the inhibitory effect on NF-κB nuclear translocation, thus causing the repression of iNOS gene induction and the inhibition in COX-2 activation through iNOS-dependent S-nitrosylation. Our findings point to cNOS activation as a pivotal element in the signaling cascade by which ghrelin exerts modulatory control over proinflammatory events triggered in gastric mucosa by H. pylori infection.展开更多
Gastric mucosal inflammatory responses to H. pylori lipopolysaccharide (LPS), are characterized by the excessive NO and prostaglandin (PGE2) generation due to the disturbances in nitric oxide synthase (NOS) and cycloo...Gastric mucosal inflammatory responses to H. pylori lipopolysaccharide (LPS), are characterized by the excessive NO and prostaglandin (PGE2) generation due to the disturbances in nitric oxide synthase (NOS) and cyclooxygenase (COX) systems. Here, we report that the LPS-induced enhancement in gastric mucosal inducible (i) iNOS) activity and up-regulation in PGE2 production was associated with the suppression in Akt kinase activity and the impairment in constitutive (c) cNOS activation. The stimulatory effect of the LPS on PGE2 production, furthermore, was susceptible to suppression by COX-2 inhibitor, NS-398, and iNOS inhibitor, 1400 W. Further, we show that the countering effect of peptide hormone, ghrelin, on the LPS-induced changes was reflected in up-regu- lation in Akt activity and the increase in cNOS activation through phosphorylation, and accompanied by the suppression in iNOS expression and the reduction in COX-2 activity associated with the loss in COX-2 protein S-nitrosylation. Moreover, the effect of ghre-lin on the LPS-induced COX-2 S-nitrosylation was subject to repression by Akt inhibition. Our findings demonstrate that induction in iNOS with H. pylori in- fection leads to COX-2 activation through S-nitro- sylation and up-regulation in PGE2 generation, and that ghrelin counters these untoward consequences of the LPS through Akt-mediated up-regulation in cNO- S activation required for the iNOS gene repression.展开更多
Disturbances in nitric oxide synthase (NOS) system and the excessive prostaglandin (PGE2) generation are well-recognized features of oral mucosal inflammatory responses to periodontopathic bacterium, P. gingivalis. Em...Disturbances in nitric oxide synthase (NOS) system and the excessive prostaglandin (PGE2) generation are well-recognized features of oral mucosal inflammatory responses to periodontopathic bacterium, P. gingivalis. Employing rat sublingual gland acinar cells, we show that P. gingivalis LPS-induced up-regulation in PGE2 generation and the enhancement in inducible (i) iNOS activity was associated with COX-2 activation through S-nitrosylation, and accompanied by the suppression in cSrc activity and the impairment in constitutive (c) cNOS phosphorylation. Further, we demonstrate that the countering effect of peptide hormone, ghrelin, on the LPS-induced changes was reflected in the increased cNOS activation through phosphorylation, repression in iNOS induction, and the reduction in PGE2 generation associated with the loss of COX-2 protein S-nitrosylation. Moreover, the effect of ghrelin on cNOS phosphorylation and the LPS-induced COX-2 S-nitrosylation was susceptible to the blockage by cSrc inhibition. Our findings suggest that P. gingivalis-induced up-regulation in iNOS leads to COX-2 S-nitrosylation and up-regulation in PGE2 generation, and that the countering effect of ghrelin is mediated through Src-dependent cNOS activation that is obligatory for the maintenance of iNOS gene suppression.展开更多
文摘目的:探讨COX-2促进结直肠癌肝转移效果及其机制,从而为结直肠癌肝转移防治提供依据。方法:建立COX-2低表达和高表达CT26结肠癌细胞株,通过注射0.2 m L的对数生长期细胞浓度为1×10~6个/mL的正常CT26结肠癌细胞悬液(A组,n=20)、COX-2高表达的CT26结肠癌细胞悬液(B组,n=20)以及COX-2低表达的结肠癌细胞悬液(C组,n=20)至脾脏制作小鼠结肠癌肝转移模型,检测比较三组小鼠移植瘤COX-2、PI3K、p-Akt表达、移植瘤体积、肝脏肿瘤大小和数量以及生存期,并分析结直肠癌肝转移小鼠COX-2、PI3K、p-Akt表达的相互关系以及三者与其移植瘤体积、肝脏肿瘤大小和数量以及生存期的关系。结果:与A组比较,B组和C组移植瘤COX-2、PI3K、p-Akt蛋白检测阳性率均升高,移植瘤体积降低,肝脏肿瘤大小和数量降低,生存期延长(P<0.05)。与B组比较,C组移植瘤COX-2、PI3K、p-Akt蛋白检测阳性率均升高,移植瘤体积降低,肝脏肿瘤大小和数量降低,生存期延长(P<0.05)。Spearman相关分析结果显示,结直肠癌肝转移小鼠移植瘤COX-2蛋白表达与其PI3K、p-Akt蛋白表达呈正相关(P<0.05),且其移植瘤COX-2、PI3K、p-Akt与其移植瘤体积、肝脏肿瘤大小和数量均呈正相关(P<0.05),与其生存期均呈负相关(P<0.05)。结论:COX-2可促结直肠癌肝转移和影响其预后,在此过程中可能涉及其活化PI3K/Akt信号通路作用。
文摘Disturbances in nitric oxide synthase (NOS) and cyclooxygenase (COX) isozyme systems, manifested by the excessive NO and prostaglandin (PGE2) generation, are well-recognized features of gastric mucosal inflammatory responses to H. pylori infection. In this study, we report that H. pylori LPS-induced enhancement in gastric mucosal inducible (i) iNOS expression and COX-2 activation was accompanied by the impairment in constitutive (c) cNOS phosphorylation, up-regulation in the inhibitory κB kinase-β (IKKβ) activation and the increase in the transcriptional factor, NF-κB, nuclear translocation. Further, we show that abrogation of cNOS control over NF-κB activation has lead to induction of iNOS expression and COX-2 activation through S-nitrosylation. Moreover, we demonstrate that the modulatory effect of peptide hormone, ghrelin, on the LPS-induced changes was reflected in the increase in Src/Akt-dependent cNOS activation through phosphorylation and the suppression of IKK-β activity through cNOS-mediated IKK-β protein S-nitrosylation. As a result, ghrelin exerted the inhibitory effect on NF-κB nuclear translocation, thus causing the repression of iNOS gene induction and the inhibition in COX-2 activation through iNOS-dependent S-nitrosylation. Our findings point to cNOS activation as a pivotal element in the signaling cascade by which ghrelin exerts modulatory control over proinflammatory events triggered in gastric mucosa by H. pylori infection.
文摘Gastric mucosal inflammatory responses to H. pylori lipopolysaccharide (LPS), are characterized by the excessive NO and prostaglandin (PGE2) generation due to the disturbances in nitric oxide synthase (NOS) and cyclooxygenase (COX) systems. Here, we report that the LPS-induced enhancement in gastric mucosal inducible (i) iNOS) activity and up-regulation in PGE2 production was associated with the suppression in Akt kinase activity and the impairment in constitutive (c) cNOS activation. The stimulatory effect of the LPS on PGE2 production, furthermore, was susceptible to suppression by COX-2 inhibitor, NS-398, and iNOS inhibitor, 1400 W. Further, we show that the countering effect of peptide hormone, ghrelin, on the LPS-induced changes was reflected in up-regu- lation in Akt activity and the increase in cNOS activation through phosphorylation, and accompanied by the suppression in iNOS expression and the reduction in COX-2 activity associated with the loss in COX-2 protein S-nitrosylation. Moreover, the effect of ghre-lin on the LPS-induced COX-2 S-nitrosylation was subject to repression by Akt inhibition. Our findings demonstrate that induction in iNOS with H. pylori in- fection leads to COX-2 activation through S-nitro- sylation and up-regulation in PGE2 generation, and that ghrelin counters these untoward consequences of the LPS through Akt-mediated up-regulation in cNO- S activation required for the iNOS gene repression.
文摘Disturbances in nitric oxide synthase (NOS) system and the excessive prostaglandin (PGE2) generation are well-recognized features of oral mucosal inflammatory responses to periodontopathic bacterium, P. gingivalis. Employing rat sublingual gland acinar cells, we show that P. gingivalis LPS-induced up-regulation in PGE2 generation and the enhancement in inducible (i) iNOS activity was associated with COX-2 activation through S-nitrosylation, and accompanied by the suppression in cSrc activity and the impairment in constitutive (c) cNOS phosphorylation. Further, we demonstrate that the countering effect of peptide hormone, ghrelin, on the LPS-induced changes was reflected in the increased cNOS activation through phosphorylation, repression in iNOS induction, and the reduction in PGE2 generation associated with the loss of COX-2 protein S-nitrosylation. Moreover, the effect of ghrelin on cNOS phosphorylation and the LPS-induced COX-2 S-nitrosylation was susceptible to the blockage by cSrc inhibition. Our findings suggest that P. gingivalis-induced up-regulation in iNOS leads to COX-2 S-nitrosylation and up-regulation in PGE2 generation, and that the countering effect of ghrelin is mediated through Src-dependent cNOS activation that is obligatory for the maintenance of iNOS gene suppression.
