AIM： To investigate the role of opioid p-receptor subtype in opiate-induced constipation （OIC）.METHODS： The effect of Ioperamide on intestinal transit was investigated in mice. Ileum strips were isolated from 12-w...AIM： To investigate the role of opioid p-receptor subtype in opiate-induced constipation （OIC）.METHODS： The effect of Ioperamide on intestinal transit was investigated in mice. Ileum strips were isolated from 12-wk-old male BALB/c mice for identification of isometric tension. The ileum strips were precontracted with 1 μmol/L acetylcholine （ACh）. Then, decrease in muscle tone （relaxation） was characterized after cumu- lative administration of 0.1-10μ~mol/L Ioperamide into the organ bath, for a concentration-dependent study. Specific blockers or antagonists were used for pretreat- ment to compare the changes in Ioperamide-induced relaxation.RESULTS： In addition to the delay in intestinal transit, Ioperamide produced a marked relaxation in isolated ileum precontracted with ACh, in a dose-dependent manner. This relaxation was abolished by cyprodime,a selective opioid p-receptor antagonist, but not modified by naloxonazine at a dose sufficient to block opioid μ-1 receptors. Also, treatment with opioid μ-1 receptor agonist failed to modify the muscle tone. Moreover, the relaxation by Ioperamide was attenuated by glibenclamide at a dose sufficient to block ATP-sensitive K^＋ （KATP） channels, and by protein kinase A （PKA） inhibitor, but was enhanced by an inhibitor of phosphodiesterase for cyclic adenosine monophosphate （cAMP）.CONCLUSION： Loperamide induces intestinal relaxa- tion by activation of opioid μ-2 receptors via the cAMP- PKA pathway to open KATp channels, relates to OIC.展开更多
AIM:To investigate the role of insulin-like growth factor binding protein-7 (IGFBP-7) in the activation and transdifferentiation of hepatic stellate cells (HSC) in vitro.METHODS:Rat HSC-T6 cells were cultured in separ...AIM:To investigate the role of insulin-like growth factor binding protein-7 (IGFBP-7) in the activation and transdifferentiation of hepatic stellate cells (HSC) in vitro.METHODS:Rat HSC-T6 cells were cultured in separate dishes and treated with various concentration of transforming growth factor (TGF)-β1,IGFBP-7 or antiIGFBP-7 antibody for 24 h.The supernatant or a cytoplasm suspension was obtained from cultured HSC,followed by transfer of cells to form cell-coated dishes.Immunocytochemistry and Western blotting were used to analyze the expression of IGFBP-7 induced by TGF-β1 and the level of fibronectin,collagen and α-smooth muscle actin (SMA).The pro-apoptotic effect of antiIGFBP-7 antibody was determined by flow cytometry.RESULTS:Immunocytochemistry and Western blotting revealed that the expression of IGFBP-7 in TGF-β1 treated HSC was significantly up-regulated compared to that in the control group.In addition,fibronectin,collagen and α-SMA also showed enhanced expression in accordance with the transdifferentiation process in a dose-dependent manner to some extent.Moreover,flow cytometry suggested that anti-IGFBP-7 antibody induced apoptosis of activated HSC,which is responsible for the development of liver fibrosis,and may represent a novel pathway and target for therapeutic intervention.CONCLUSION:IGFBP-7 showed increased expression in activated HSC and played an important role in the activation and transdifferentiation process of HSC.AntiIGFBP-7 antibody may ameliorate liver fibrogenesis.展开更多
We have previously reported that AD5-10, a novel agonistic monoclonal antibody against DRS, possessed a strong cytotoxic activity in various tumor cells, via induction of caspase-dependent and -independent signaling p...We have previously reported that AD5-10, a novel agonistic monoclonal antibody against DRS, possessed a strong cytotoxic activity in various tumor cells, via induction of caspase-dependent and -independent signaling pathways. The present study further demonstrates that reactive oxygen species （ROS） were generated in abundance in Jurkat leukemia cells upon AD5-10 stimulation and that ROS accumulation subsequently evoked sustained activation of c-Jun N-terminal kinase （JNK）, loss of mitochondrial membrane potential, and release of endonuclease G （Endo G） from mitochondria into the cytosol. The reducing agent, N-acetylcysteine （NAC）, effectively inhibited the sustained activation of JNK, release of Endo G, and cell death in Jurkat cells treated by AD5-10. Moreover, a dominant-negative form of JNK （but not of p38） enhanced NF-κB activation, suppressed caspase-8 recruitment in death-inducing signaling complexes （DISCs）, and reduced adverse effects on mitochondria, thereby inhibiting AD5-10-induced cell death in Jnrkat leukemia cells. These data provide novel information on the DR5-mediated ceil death-signaling path- way and may shed new light on effective strategies for leukemia and solid tumor therapies.展开更多
Hydrogen sulfide(H_2S)has been found to be the third most important endogenous gaseous signaling molecule after nitric oxide(NO)and carbonic oxide(CO)and plays crucial roles in living organisms and biological systems....Hydrogen sulfide(H_2S)has been found to be the third most important endogenous gaseous signaling molecule after nitric oxide(NO)and carbonic oxide(CO)and plays crucial roles in living organisms and biological systems.Here we use aggregation-induced emission(AIE)of a small organic molecule(TPE-indo)to detect H_2S in both solution and living cells.TPE-indo can target mitochondria and aggregate to fluoresce,which can serve as a sensor for monitoring H_2S in the mitochondria.We regulate the fluorescence of AIE molecules by tuning the viscosity of the solution to form TPE-indo nanoparticles,constructing a probe for H_2S with good selectivity and high sensitivity.The nucleophilic addition of HS-to the TPE-indo is crucial for the rapid H_2S detection.The imaging and analysis of H_2S in mitochondria of living cells with the probe demonstrate potential biological applications.展开更多
基金Supported by A grant from E-Da Hospital (in part)
文摘AIM： To investigate the role of opioid p-receptor subtype in opiate-induced constipation （OIC）.METHODS： The effect of Ioperamide on intestinal transit was investigated in mice. Ileum strips were isolated from 12-wk-old male BALB/c mice for identification of isometric tension. The ileum strips were precontracted with 1 μmol/L acetylcholine （ACh）. Then, decrease in muscle tone （relaxation） was characterized after cumu- lative administration of 0.1-10μ~mol/L Ioperamide into the organ bath, for a concentration-dependent study. Specific blockers or antagonists were used for pretreat- ment to compare the changes in Ioperamide-induced relaxation.RESULTS： In addition to the delay in intestinal transit, Ioperamide produced a marked relaxation in isolated ileum precontracted with ACh, in a dose-dependent manner. This relaxation was abolished by cyprodime,a selective opioid p-receptor antagonist, but not modified by naloxonazine at a dose sufficient to block opioid μ-1 receptors. Also, treatment with opioid μ-1 receptor agonist failed to modify the muscle tone. Moreover, the relaxation by Ioperamide was attenuated by glibenclamide at a dose sufficient to block ATP-sensitive K^＋ （KATP） channels, and by protein kinase A （PKA） inhibitor, but was enhanced by an inhibitor of phosphodiesterase for cyclic adenosine monophosphate （cAMP）.CONCLUSION： Loperamide induces intestinal relaxa- tion by activation of opioid μ-2 receptors via the cAMP- PKA pathway to open KATp channels, relates to OIC.
基金Supported by National Natural Science Foundation of China No.30740031,No.30871146the New Century Excellent Talent of the Ministry of Education of China,No.NCET-06-0264
文摘AIM:To investigate the role of insulin-like growth factor binding protein-7 (IGFBP-7) in the activation and transdifferentiation of hepatic stellate cells (HSC) in vitro.METHODS:Rat HSC-T6 cells were cultured in separate dishes and treated with various concentration of transforming growth factor (TGF)-β1,IGFBP-7 or antiIGFBP-7 antibody for 24 h.The supernatant or a cytoplasm suspension was obtained from cultured HSC,followed by transfer of cells to form cell-coated dishes.Immunocytochemistry and Western blotting were used to analyze the expression of IGFBP-7 induced by TGF-β1 and the level of fibronectin,collagen and α-smooth muscle actin (SMA).The pro-apoptotic effect of antiIGFBP-7 antibody was determined by flow cytometry.RESULTS:Immunocytochemistry and Western blotting revealed that the expression of IGFBP-7 in TGF-β1 treated HSC was significantly up-regulated compared to that in the control group.In addition,fibronectin,collagen and α-SMA also showed enhanced expression in accordance with the transdifferentiation process in a dose-dependent manner to some extent.Moreover,flow cytometry suggested that anti-IGFBP-7 antibody induced apoptosis of activated HSC,which is responsible for the development of liver fibrosis,and may represent a novel pathway and target for therapeutic intervention.CONCLUSION:IGFBP-7 showed increased expression in activated HSC and played an important role in the activation and transdifferentiation process of HSC.AntiIGFBP-7 antibody may ameliorate liver fibrogenesis.
基金Acknowledgments We thank Dr Shimin Hu for his generous gifts of constructs. This work was partially supported by National Natural Science Foundation of China （Grant Nos. 30571687 and 30721063） and by State Key Basic Research Program of China （Grant No. 2007CB507404）.
文摘We have previously reported that AD5-10, a novel agonistic monoclonal antibody against DRS, possessed a strong cytotoxic activity in various tumor cells, via induction of caspase-dependent and -independent signaling pathways. The present study further demonstrates that reactive oxygen species （ROS） were generated in abundance in Jurkat leukemia cells upon AD5-10 stimulation and that ROS accumulation subsequently evoked sustained activation of c-Jun N-terminal kinase （JNK）, loss of mitochondrial membrane potential, and release of endonuclease G （Endo G） from mitochondria into the cytosol. The reducing agent, N-acetylcysteine （NAC）, effectively inhibited the sustained activation of JNK, release of Endo G, and cell death in Jurkat cells treated by AD5-10. Moreover, a dominant-negative form of JNK （but not of p38） enhanced NF-κB activation, suppressed caspase-8 recruitment in death-inducing signaling complexes （DISCs）, and reduced adverse effects on mitochondria, thereby inhibiting AD5-10-induced cell death in Jnrkat leukemia cells. These data provide novel information on the DR5-mediated ceil death-signaling path- way and may shed new light on effective strategies for leukemia and solid tumor therapies.
基金the National Basic Research Program of China(2011CB933201,2012AA022703)the National Natural Science Foundation of China(21222502,91213305)+1 种基金Youth Innovation Promotion Association(CAS),the CAS/SAFEA International Partnership Program for Creative Research Teamsthe“Strategic Priority Research Program”of the Chinese Academy of Sciences(XDA09030305)
文摘Hydrogen sulfide(H_2S)has been found to be the third most important endogenous gaseous signaling molecule after nitric oxide(NO)and carbonic oxide(CO)and plays crucial roles in living organisms and biological systems.Here we use aggregation-induced emission(AIE)of a small organic molecule(TPE-indo)to detect H_2S in both solution and living cells.TPE-indo can target mitochondria and aggregate to fluoresce,which can serve as a sensor for monitoring H_2S in the mitochondria.We regulate the fluorescence of AIE molecules by tuning the viscosity of the solution to form TPE-indo nanoparticles,constructing a probe for H_2S with good selectivity and high sensitivity.The nucleophilic addition of HS-to the TPE-indo is crucial for the rapid H_2S detection.The imaging and analysis of H_2S in mitochondria of living cells with the probe demonstrate potential biological applications.
