The action of ciliary neurotrophic factor (CNTF) on intercellular free Ca2+ concentrations [Ca2+]1 induced by glutamate (Glu) in primary cultured hippocampal neurons were detected with Fura2/AM, a Ca2+-sensitive fluor...The action of ciliary neurotrophic factor (CNTF) on intercellular free Ca2+ concentrations [Ca2+]1 induced by glutamate (Glu) in primary cultured hippocampal neurons were detected with Fura2/AM, a Ca2+-sensitive fluorophore. and the morphological influence of G-protein on it was ob-jected. Glu could induce rapid increase of [Ca2+]1 in hippo-campal neurons. CNTF had no significant action on [Ca2+]1 in resting hippocampal neurons. However, after incubation of CNTF for 5 min, the increase of [Ca2+]1 in hippocampal neurons rapidly induced by Glu was inhibited. Pretussis toxin (PTX)-sensitive G protein could block the action. These results indicate that a new non-genomic rapid sideway might exist in the upper stream of CNTF signal transduction pathway, which was related to Ca2+ signal transduction.展开更多
In order to investigate whether the non-classi- cal HLA-G classⅠmolecule protects the porcine endothelial cells (PECs) from the lysis mediated by human immune cells in pig to human discordant xenotransplantation, we ...In order to investigate whether the non-classi- cal HLA-G classⅠmolecule protects the porcine endothelial cells (PECs) from the lysis mediated by human immune cells in pig to human discordant xenotransplantation, we have cloned HLA-G cDNA from a human placenta by RT-PCR. Mammalian expression vector, pEFG-neo, was constructed by insertion of HLA-G cDNA in pEF-neo. We obtained effi-ciently expressed PECs by stable transfection. Cytotoxicity assay showed that overexpression of HLA-G on PECs was sufficient to inhibit human NK-92 cell lysis. The level of lysis was equal to or less than that of the lysis of human umbilical vein endothelial cells mediated by human NK-92 cells. It also indicated that HLA-G inhibited the lysis of PECs mediated by xeno-antigen specific T lymphocytes. The reduction of lysis ranged between 59.1% and 88.9%. These findings sug-gest that the transgenic approach to overexpress HLA-G is believed to be a new immunotherapy in overcoming the im-mune rejections in xenotransplantion, including delayed xenograft rejection and cell-mediated rejection.展开更多
基金the NationalNatural Science Foundation of China (Grant Nos. 39930080 and 39670259) and Medicine and Pharmacy Foundation of PLA (Grant Nos. 96M077 and 98M079).
文摘The action of ciliary neurotrophic factor (CNTF) on intercellular free Ca2+ concentrations [Ca2+]1 induced by glutamate (Glu) in primary cultured hippocampal neurons were detected with Fura2/AM, a Ca2+-sensitive fluorophore. and the morphological influence of G-protein on it was ob-jected. Glu could induce rapid increase of [Ca2+]1 in hippo-campal neurons. CNTF had no significant action on [Ca2+]1 in resting hippocampal neurons. However, after incubation of CNTF for 5 min, the increase of [Ca2+]1 in hippocampal neurons rapidly induced by Glu was inhibited. Pretussis toxin (PTX)-sensitive G protein could block the action. These results indicate that a new non-genomic rapid sideway might exist in the upper stream of CNTF signal transduction pathway, which was related to Ca2+ signal transduction.
基金This work was supported by the National Natural Science Foundation of China(Grant No.39993430)by the National?63?Project(Grant No.2001AA216071).
文摘In order to investigate whether the non-classi- cal HLA-G classⅠmolecule protects the porcine endothelial cells (PECs) from the lysis mediated by human immune cells in pig to human discordant xenotransplantation, we have cloned HLA-G cDNA from a human placenta by RT-PCR. Mammalian expression vector, pEFG-neo, was constructed by insertion of HLA-G cDNA in pEF-neo. We obtained effi-ciently expressed PECs by stable transfection. Cytotoxicity assay showed that overexpression of HLA-G on PECs was sufficient to inhibit human NK-92 cell lysis. The level of lysis was equal to or less than that of the lysis of human umbilical vein endothelial cells mediated by human NK-92 cells. It also indicated that HLA-G inhibited the lysis of PECs mediated by xeno-antigen specific T lymphocytes. The reduction of lysis ranged between 59.1% and 88.9%. These findings sug-gest that the transgenic approach to overexpress HLA-G is believed to be a new immunotherapy in overcoming the im-mune rejections in xenotransplantion, including delayed xenograft rejection and cell-mediated rejection.
