Objective Our previous study identified Threonine 161 （Thr-161）, located in the second intracellular loop of the 6-opioid receptor （DOR）, as the only consensus phosphorylation Cdte for cyclin-dqpendent kinase 5 （...Objective Our previous study identified Threonine 161 （Thr-161）, located in the second intracellular loop of the 6-opioid receptor （DOR）, as the only consensus phosphorylation Cdte for cyclin-dqpendent kinase 5 （CdkS）. The aim of this study was to assess the function of DOR phosphorylation by Cdk5 in complete Freund＇s adjuvant （CFA）-induced inflammatory pain and morphine tolerance. Methods Dorsal root ganglion （DRG） neurons of rats with CFA-induced in- flammatory pain were acutely dissociated and the biotinylation method was used to explore the membrane localization of phosphorylated DOR at Thr-161 （pThr-161-DOR）, and paw withdrawal latency was measured after intrathecal delivery of drugs or Tat-peptide, using a radiant heat stimulator in rats with CFA-induced inflammatory pain. Results Both the total amount and the surface localization of pThr-161-DOR were significantly enhanced in the ipsilateral DRG following CFA injection. lntrathecal delivery of the engineered Tat fusion-interefering peptide corresponding to the second intracellular loop of DOR （Tat-DOR-2L） increased inflammatory hypersensitivity, and inhibited DOR- but not μ-opioid receptor-mediated spinal analgesia in CFA-treated rats. However, intrathecal delivery of Tat-DOR-2L postponed morphine antinociceptive tolerance in rats with CFA-induced inflammatory pain. Conclusion Phosphorylation of DOR at Thr-161 by Cdk5 attenuates hypersensitivity and potentiates morphine tolerance in rats with CFA-induced inflammatory pain, while disruption of the phosphorylation of DOR at Thr- 161 attenuates morphine tolerance.展开更多
OBJECTIVE MicroR NA(miR NA)holds promise as a novel therapeutic tool for cancer treatment.However,the transfection efficiency of current delivery systems represents a bottleneck for clinical applications.Here,we demon...OBJECTIVE MicroR NA(miR NA)holds promise as a novel therapeutic tool for cancer treatment.However,the transfection efficiency of current delivery systems represents a bottleneck for clinical applications.Here,we demonstrate that gap junctions mediate an augmentative effect on the antiproliferation mediated by mi R-124-3p in U87 and C6 glioblastoma cells.METHODS The functional inhibition of gap junctions using either si RNA or pharmacological inhibition eliminated the mi R-124-3p-mediated antiproliferation,whereas the enhancement of gap junctions with retinoic acid treatment augmented this mi R-124-3p-mediated antiproliferation.A similar effect was observed in glioblastoma xenograft models.RESULTS More importantly,patch clamp and co-culture assays demonstrated the transmission of mi R-124-3p through gap junction channels into adjacent cells.In further exploring the impact of gap junction-mediated transport of mi R-124-3p on mi R-124-3p target pathways,we found that mi R-124-3p inhibited glioblastoma cell growth in part by decreasing the protein expression of cyclindependent kinase 6,leading to cel cycle arrest at the G0/G1phase;moreover,pharmacological regulation of gap junctions affected this cell cycle arrest.CONCLUSION Our results indicate that the″bystander″effects of functional gap junctions composed of connexin 43 enhance the antitumor effect of mi R-124-3p in glioblastoma cells by transferring mi R-124-3p to adjacent cells,thereby enhancing G0/G1cell cycle arrest.These observations provide a new guiding strategy for the clinical application of mi RNA therapy in tumor treatment.展开更多
基金supported by grants from the National Natural Science Foundation of China (30830044, 30925015, 30800330, and 81161120497)Beijing Natural Science Foundation (7092061)Specialized Research Fund for Doctoral Program of Higher Education Grants, China (200800011028 and 20060001121)
文摘Objective Our previous study identified Threonine 161 （Thr-161）, located in the second intracellular loop of the 6-opioid receptor （DOR）, as the only consensus phosphorylation Cdte for cyclin-dqpendent kinase 5 （CdkS）. The aim of this study was to assess the function of DOR phosphorylation by Cdk5 in complete Freund＇s adjuvant （CFA）-induced inflammatory pain and morphine tolerance. Methods Dorsal root ganglion （DRG） neurons of rats with CFA-induced in- flammatory pain were acutely dissociated and the biotinylation method was used to explore the membrane localization of phosphorylated DOR at Thr-161 （pThr-161-DOR）, and paw withdrawal latency was measured after intrathecal delivery of drugs or Tat-peptide, using a radiant heat stimulator in rats with CFA-induced inflammatory pain. Results Both the total amount and the surface localization of pThr-161-DOR were significantly enhanced in the ipsilateral DRG following CFA injection. lntrathecal delivery of the engineered Tat fusion-interefering peptide corresponding to the second intracellular loop of DOR （Tat-DOR-2L） increased inflammatory hypersensitivity, and inhibited DOR- but not μ-opioid receptor-mediated spinal analgesia in CFA-treated rats. However, intrathecal delivery of Tat-DOR-2L postponed morphine antinociceptive tolerance in rats with CFA-induced inflammatory pain. Conclusion Phosphorylation of DOR at Thr-161 by Cdk5 attenuates hypersensitivity and potentiates morphine tolerance in rats with CFA-induced inflammatory pain, while disruption of the phosphorylation of DOR at Thr- 161 attenuates morphine tolerance.
基金The project supported by National Natural Science Foundation of China(81473234,U1303221)
文摘OBJECTIVE MicroR NA(miR NA)holds promise as a novel therapeutic tool for cancer treatment.However,the transfection efficiency of current delivery systems represents a bottleneck for clinical applications.Here,we demonstrate that gap junctions mediate an augmentative effect on the antiproliferation mediated by mi R-124-3p in U87 and C6 glioblastoma cells.METHODS The functional inhibition of gap junctions using either si RNA or pharmacological inhibition eliminated the mi R-124-3p-mediated antiproliferation,whereas the enhancement of gap junctions with retinoic acid treatment augmented this mi R-124-3p-mediated antiproliferation.A similar effect was observed in glioblastoma xenograft models.RESULTS More importantly,patch clamp and co-culture assays demonstrated the transmission of mi R-124-3p through gap junction channels into adjacent cells.In further exploring the impact of gap junction-mediated transport of mi R-124-3p on mi R-124-3p target pathways,we found that mi R-124-3p inhibited glioblastoma cell growth in part by decreasing the protein expression of cyclindependent kinase 6,leading to cel cycle arrest at the G0/G1phase;moreover,pharmacological regulation of gap junctions affected this cell cycle arrest.CONCLUSION Our results indicate that the″bystander″effects of functional gap junctions composed of connexin 43 enhance the antitumor effect of mi R-124-3p in glioblastoma cells by transferring mi R-124-3p to adjacent cells,thereby enhancing G0/G1cell cycle arrest.These observations provide a new guiding strategy for the clinical application of mi RNA therapy in tumor treatment.
