Islets from RIP-PDE3B mice, exhibiting β-cell specific overexpression of the cAMP/cGMP-degrading enzyme phosphodiesterase 3B (PDE3B) and dysregulated insulin secretion, were subjected to microarray analysis. We show ...Islets from RIP-PDE3B mice, exhibiting β-cell specific overexpression of the cAMP/cGMP-degrading enzyme phosphodiesterase 3B (PDE3B) and dysregulated insulin secretion, were subjected to microarray analysis. We show that osteopontin (OPN) mRNA is increased in a dose-dependent manner in islets from RIP-PDE3B mice, as compared to wild-type islets. In addition, in silico analysis shows that PDE3B and OPN are interacting. Furthermore, OPN interacts with protein kinase CK2 ina distinct submodule of the protein-protein interaction network. We studied PDE3B and OPN proteins and, in some cases, also PDE1B and PDE4C, under conditions of relevance for insulin secretion. In the presence of forskolin, PDE inhibitors, insulin, or a protein kinase CK2 inhibitor, similar alterations in protein levels of PDE3B and OPN are shown. In summary, results from using a number of strategies demonstrate a connection between PDE3B and OPNas well as a role for protein kinase CK2 inpancreatic β-cells.展开更多
The endoplasmic reticulum is the central organelle within a eukaryotic cell where newly synthesized proteins are processed and properly folded. An excess of unfolded or mis-folded proteins induces ER stress signalling...The endoplasmic reticulum is the central organelle within a eukaryotic cell where newly synthesized proteins are processed and properly folded. An excess of unfolded or mis-folded proteins induces ER stress signalling pathways. Usually this means a pro-survival strategy for the cell, whereas under extended stress conditions the ER stress signalling pathways have a pro-apoptotic function. CK2 plays a key role in the regulation of the pro-survival as well as the proapoptotic ER stress signalling by directly modulating the activities of members of the ER stress signalling pathways by phosphorylation, regulating the expression of the key factors of the signalling pathways or binding to regulator proteins. The present review will summarize the state of the art in this new emerging field.展开更多
Trail, a tumor necrosis factor-related apoptosis-inducing ligand, is a novel potent endogenous activator of the cell death pathway through the activation of cell surface death receptors Trail-R1 and Trail-R2. Its role...Trail, a tumor necrosis factor-related apoptosis-inducing ligand, is a novel potent endogenous activator of the cell death pathway through the activation of cell surface death receptors Trail-R1 and Trail-R2. Its role, like FasL in activation-induced cell death (AICD), has been demonstrated in immune system. However the mechanism of Trail induced apoptosis remains unclear. In this report, the recombinant Trail protein was expressed and purified. The apoptosis-inducing activity and the regulation mechanism of recombinant Trail on Jurkat T cells were explored in vitro. Trypan blue exclusion assay demonstrated that the recombinant Trail protein actively killed Jurkat T cells in a dose-dependent manner. Trail-induced apoptosis in Jurkat T cells were remarkably reduced by Bcl-2 over expression in Bcl-2 gene transfected cells. Treatment with PMA (phorbol 12-myristate 13-acetate), a PKC activator, suppressed Trail-induced apoptosis in Jurkat T cells. The inhibition of apoptosis by PMA was abolished by pretreatment with Bis, a PKC inhibitor. Taken together, it was suggested that Bcl-2 over-expression and PMA activated PKC actively down-regulated the Trail-mediated apoptosis in Jurkat T cell.展开更多
Membrane depolarization induces the release of the serine proteinase tissue-type plasminogen activator（t PA） from the presynaptic terminal of cerebral cortical neurons.Once in the synaptic cleft this t PA promotes t...Membrane depolarization induces the release of the serine proteinase tissue-type plasminogen activator（t PA） from the presynaptic terminal of cerebral cortical neurons.Once in the synaptic cleft this t PA promotes the exocytosis and subsequent endocytic retrieval of glutamate-containing synaptic vesicles,and regulates the postsynaptic response to the presynaptic release of glutamate.Indeed,t PA has a bidirectional effect on the composition of the postsynaptic density（PSD） that does not require plasmin generation or the presynaptic release of glutamate,but varies according to the baseline level of neuronal activity.Hence,in inactive neurons t PA induces phosphorylation and accumulation in the PSD of the Ca^（2＋）/calmodulin-dependent protein kinase IIα（pCa MKIIα）,followed by pCa MKIIα-induced phosphorylation and synaptic recruitment of Glu R1-containing α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid（AMPA） receptors.In contrast,in active neurons with increased levels of pCa MKIIα in the PSD t PA induces pCa MKIIα and p Glu R1 dephosphorylation and their subsequent removal from the PSD.These effects require active synaptic N-methyl-D-aspartate（NMDA） receptors and cyclin-dependent kinase 5（Cdk5）-induced phosphorylation of the protein phosphatase 1（PP1） at T320.These data indicate that t PA is a homeostatic regulator of the postsynaptic response of cerebral cortical neurons to the presynaptic release of glutamate via bidirectional regulation of the pCa MKIIα/PP1 switch in the PSD.展开更多
目的:探讨鸢尾素调节Janus蛋白酪氨酸激酶2(Janus protein tyrosine kinase 2,JAK2)/信号转导和转录激活子3(Signal transduction and activator of transcription 3,STAT3)信号通路对牙周炎大鼠牙周组织损伤的影响。方法:通过结扎和接...目的:探讨鸢尾素调节Janus蛋白酪氨酸激酶2(Janus protein tyrosine kinase 2,JAK2)/信号转导和转录激活子3(Signal transduction and activator of transcription 3,STAT3)信号通路对牙周炎大鼠牙周组织损伤的影响。方法:通过结扎和接种牙龈卟啉单胞菌液建立牙周炎大鼠模型,将大鼠随机分为模型组、鸢尾素低(鸢尾素-L,50 mg/kg)、中(鸢尾素-M,100 mg/kg)、高剂量(鸢尾素-H,200 mg/kg)组、鸢尾素-H+激活剂(200 mg/kg鸢尾素+2 mg/kg香豆霉素)组,每组10只,并以注射等体积生理盐水的正常大鼠对照组。干预结束后,对大鼠牙龈出血指数、牙齿松动度评分;牙槽骨吸收、肿瘤坏死因子-α(Tumor necrosis factor-α,TNF-α)、白细胞介素(Interleukin,IL)-6、IL-1β以及丙二醛(Malondialdehyde,MDA)、超氧化物歧化酶(Superoxide dismutase,SOD)水平分别以Micro-CT试剂盒检测;HE检测牙周组织病理学变化;Western blot检测JAK2、STAT3、p-JAK2、p-STAT3蛋白表达。结果:与对照组相比,模型组大鼠牙周组织被破坏,炎性浸润严重,牙龈出血指数、牙齿松动度评分、牙槽骨吸收、TNF-α、IL-6、IL-1β、MDA水平、p-JAK2/JAK2、p-STAT3/STAT3表达显著增加,SOD水平显著降低(P<0.05);与模型组相比,不同剂量的鸢尾素组大鼠病理损伤得到改善,牙龈出血指数、牙齿松动度评分、牙槽骨吸收、TNF-α、IL-6、IL-1β、MDA水平、p-JAK2/JAK2、p-STAT3/STAT3表达显著降低,SOD水平显著增加,具有剂量依赖性(P<0.05);与鸢尾素-H组相比,鸢尾素-H组+激活剂组大鼠病理损伤加重,大鼠牙龈出血指数、牙齿松动度评分、牙槽骨吸收、TNF-α、IL-6、IL-1β、MDA水平、p-JAK2/JAK2、p-STAT3/STAT3表达显著增加,SOD水平显著降低(P<0.05)。结论:鸢尾素抑制牙周炎大鼠氧化应激、炎性反应,减轻大鼠牙周组织损伤,减少牙槽骨吸收,可能与抑制JAK2/STAT3信号通路有关。展开更多
Background Human antigen R （HuR） is a ubiquitously expressed member of the ELAV family, and has relatively high cytoplasmic abundance in lung tissue regenerating after injury. In this study, we investigated whether ...Background Human antigen R （HuR） is a ubiquitously expressed member of the ELAV family, and has relatively high cytoplasmic abundance in lung tissue regenerating after injury. In this study, we investigated whether mitogen-activated protein kinase （MAPK）-activated protein kinase 2 （MK2） and HuR participate in the tumor necrosis factor （TNF）-induced expression of interleukin-6 （IL-6）. Methods Human pulmonary microvascular endothelial cells were treated with TNF following short interfering RNAmediated knockdown of MK2 or HuR. Cell supernatants were collected to detect the mRNA and protein expression of IL-6 at different time points, The expression and half-life of IL-6 mRNA were then determined in cells that had been treated with actinomycin D. Finally, after knockdown of MK2, the cytoplasmic expression of HuR protein was analyzed using Western blotting. Results MK2 or HuR knockdown decreased both the mRNA and protein expression of IL-6 in TNF-stimulated cells. In MK2 knockdown cells, the half-life of IL-6 mRNA was reduced to 36 minutes, compared with 67 minutes in the control group. In HuR knockdown cells, the half-life of IL-6 mRNA decreased from 62 minutes to 24 minutes. Further analysis revealed that knockdown of MK2 resulted in reduced HuR protein expression in the cytoplasm. Conclusions MK2 regulates the TNF-induced expression of IL-6 by influencing the cytoplasmic levels of HuR.展开更多
背景与目的S期激酶相关蛋白2(Skp2)是细胞周期正性调节因子之一,它能促进周期蛋白依赖性激酶抑制剂p27的泛素化蛋白水解,在肿瘤中过表达,本研究旨在探讨非小细胞肺癌(non-small cell lung cancer NSCLC)中Skp2表达的临床意义及其与p27...背景与目的S期激酶相关蛋白2(Skp2)是细胞周期正性调节因子之一,它能促进周期蛋白依赖性激酶抑制剂p27的泛素化蛋白水解,在肿瘤中过表达,本研究旨在探讨非小细胞肺癌(non-small cell lung cancer NSCLC)中Skp2表达的临床意义及其与p27蛋白表达的关系。方法应用组织芯片和免疫组织化学方法检测Skp2和p27在68例NSCLC组织和17例正常支气管上皮细胞中的表达。结果Skp2仅在肺癌组织中表达,且与患者的组织学类型(P=0.039),肿瘤细胞的分化程度(P=0.016),性别(P=0.012)和吸烟与否(P=0.026)显著相关,而与患者的年龄和TNM分期无关。p27在正常支气管上皮细胞中均有表达,在肺癌组织中表达降低;Skp2阳性表达的患者中p27表达明显降低,两者呈负相关(P=0.021)。结论在NSCLC中,Skp2蛋白表达的增高与p27泛素化依赖的蛋白降解有关,提示Skp2蛋白过表达在NSCLC的发生和发展中可能起重要作用。展开更多
文摘Islets from RIP-PDE3B mice, exhibiting β-cell specific overexpression of the cAMP/cGMP-degrading enzyme phosphodiesterase 3B (PDE3B) and dysregulated insulin secretion, were subjected to microarray analysis. We show that osteopontin (OPN) mRNA is increased in a dose-dependent manner in islets from RIP-PDE3B mice, as compared to wild-type islets. In addition, in silico analysis shows that PDE3B and OPN are interacting. Furthermore, OPN interacts with protein kinase CK2 ina distinct submodule of the protein-protein interaction network. We studied PDE3B and OPN proteins and, in some cases, also PDE1B and PDE4C, under conditions of relevance for insulin secretion. In the presence of forskolin, PDE inhibitors, insulin, or a protein kinase CK2 inhibitor, similar alterations in protein levels of PDE3B and OPN are shown. In summary, results from using a number of strategies demonstrate a connection between PDE3B and OPNas well as a role for protein kinase CK2 inpancreatic β-cells.
文摘The endoplasmic reticulum is the central organelle within a eukaryotic cell where newly synthesized proteins are processed and properly folded. An excess of unfolded or mis-folded proteins induces ER stress signalling pathways. Usually this means a pro-survival strategy for the cell, whereas under extended stress conditions the ER stress signalling pathways have a pro-apoptotic function. CK2 plays a key role in the regulation of the pro-survival as well as the proapoptotic ER stress signalling by directly modulating the activities of members of the ER stress signalling pathways by phosphorylation, regulating the expression of the key factors of the signalling pathways or binding to regulator proteins. The present review will summarize the state of the art in this new emerging field.
基金Major State BasicResearch (973) Program of China, (G1999053905).
文摘Trail, a tumor necrosis factor-related apoptosis-inducing ligand, is a novel potent endogenous activator of the cell death pathway through the activation of cell surface death receptors Trail-R1 and Trail-R2. Its role, like FasL in activation-induced cell death (AICD), has been demonstrated in immune system. However the mechanism of Trail induced apoptosis remains unclear. In this report, the recombinant Trail protein was expressed and purified. The apoptosis-inducing activity and the regulation mechanism of recombinant Trail on Jurkat T cells were explored in vitro. Trypan blue exclusion assay demonstrated that the recombinant Trail protein actively killed Jurkat T cells in a dose-dependent manner. Trail-induced apoptosis in Jurkat T cells were remarkably reduced by Bcl-2 over expression in Bcl-2 gene transfected cells. Treatment with PMA (phorbol 12-myristate 13-acetate), a PKC activator, suppressed Trail-induced apoptosis in Jurkat T cells. The inhibition of apoptosis by PMA was abolished by pretreatment with Bis, a PKC inhibitor. Taken together, it was suggested that Bcl-2 over-expression and PMA activated PKC actively down-regulated the Trail-mediated apoptosis in Jurkat T cell.
基金supported in part by National Institutes of Health Grants NS-079331(to MY)and NS-091201(to MY)
文摘Membrane depolarization induces the release of the serine proteinase tissue-type plasminogen activator（t PA） from the presynaptic terminal of cerebral cortical neurons.Once in the synaptic cleft this t PA promotes the exocytosis and subsequent endocytic retrieval of glutamate-containing synaptic vesicles,and regulates the postsynaptic response to the presynaptic release of glutamate.Indeed,t PA has a bidirectional effect on the composition of the postsynaptic density（PSD） that does not require plasmin generation or the presynaptic release of glutamate,but varies according to the baseline level of neuronal activity.Hence,in inactive neurons t PA induces phosphorylation and accumulation in the PSD of the Ca^（2＋）/calmodulin-dependent protein kinase IIα（pCa MKIIα）,followed by pCa MKIIα-induced phosphorylation and synaptic recruitment of Glu R1-containing α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid（AMPA） receptors.In contrast,in active neurons with increased levels of pCa MKIIα in the PSD t PA induces pCa MKIIα and p Glu R1 dephosphorylation and their subsequent removal from the PSD.These effects require active synaptic N-methyl-D-aspartate（NMDA） receptors and cyclin-dependent kinase 5（Cdk5）-induced phosphorylation of the protein phosphatase 1（PP1） at T320.These data indicate that t PA is a homeostatic regulator of the postsynaptic response of cerebral cortical neurons to the presynaptic release of glutamate via bidirectional regulation of the pCa MKIIα/PP1 switch in the PSD.
基金This study was supported by the National Natural Science Foundation of China （No. 81270138）, the Natural Science Foundation of Jiangsu Province （No. BK2011657 and No. BK20130402）, and the Medical Technology Innovation Foundation of Nanjing Military Command （No. CWS 12J008）.
文摘Background Human antigen R （HuR） is a ubiquitously expressed member of the ELAV family, and has relatively high cytoplasmic abundance in lung tissue regenerating after injury. In this study, we investigated whether mitogen-activated protein kinase （MAPK）-activated protein kinase 2 （MK2） and HuR participate in the tumor necrosis factor （TNF）-induced expression of interleukin-6 （IL-6）. Methods Human pulmonary microvascular endothelial cells were treated with TNF following short interfering RNAmediated knockdown of MK2 or HuR. Cell supernatants were collected to detect the mRNA and protein expression of IL-6 at different time points, The expression and half-life of IL-6 mRNA were then determined in cells that had been treated with actinomycin D. Finally, after knockdown of MK2, the cytoplasmic expression of HuR protein was analyzed using Western blotting. Results MK2 or HuR knockdown decreased both the mRNA and protein expression of IL-6 in TNF-stimulated cells. In MK2 knockdown cells, the half-life of IL-6 mRNA was reduced to 36 minutes, compared with 67 minutes in the control group. In HuR knockdown cells, the half-life of IL-6 mRNA decreased from 62 minutes to 24 minutes. Further analysis revealed that knockdown of MK2 resulted in reduced HuR protein expression in the cytoplasm. Conclusions MK2 regulates the TNF-induced expression of IL-6 by influencing the cytoplasmic levels of HuR.
文摘背景与目的S期激酶相关蛋白2(Skp2)是细胞周期正性调节因子之一,它能促进周期蛋白依赖性激酶抑制剂p27的泛素化蛋白水解,在肿瘤中过表达,本研究旨在探讨非小细胞肺癌(non-small cell lung cancer NSCLC)中Skp2表达的临床意义及其与p27蛋白表达的关系。方法应用组织芯片和免疫组织化学方法检测Skp2和p27在68例NSCLC组织和17例正常支气管上皮细胞中的表达。结果Skp2仅在肺癌组织中表达,且与患者的组织学类型(P=0.039),肿瘤细胞的分化程度(P=0.016),性别(P=0.012)和吸烟与否(P=0.026)显著相关,而与患者的年龄和TNM分期无关。p27在正常支气管上皮细胞中均有表达,在肺癌组织中表达降低;Skp2阳性表达的患者中p27表达明显降低,两者呈负相关(P=0.021)。结论在NSCLC中,Skp2蛋白表达的增高与p27泛素化依赖的蛋白降解有关,提示Skp2蛋白过表达在NSCLC的发生和发展中可能起重要作用。
