光敏剂磺酸化铝络酞菁(SALPC)光动力作用所产生的单线态氧分子(1O2),永久性激活分离大鼠胰腺腺泡细胞内源性的和在HEK293细胞异源表达的胆囊收缩素1型受体(cholecystokinin type 1 receptor, CCK1R).基因编码的蛋白质光敏剂(genetically...光敏剂磺酸化铝络酞菁(SALPC)光动力作用所产生的单线态氧分子(1O2),永久性激活分离大鼠胰腺腺泡细胞内源性的和在HEK293细胞异源表达的胆囊收缩素1型受体(cholecystokinin type 1 receptor, CCK1R).基因编码的蛋白质光敏剂(genetically encoded protein photosensitiser, GEPP)毒杀红(KillerRed)、迷你单(miniSOG)在胰腺腺泡肿瘤细胞系AR4-2J质膜定位表达后,光动力永久激活AR4-2J细胞内源性CCK1R.细胞特异性KillerRed或miniSOG光动力作用,有望为阐述CCK1R的生理功能提供直接证据.潜在"嘎嘣脆"受体嵌合体的出现,将可实现对其他G蛋白偶联受体的在体原位远程调控.本文综述了实验室发现"嘎嘣脆"受体(可被1O2永久性激活的G蛋白偶联受体)的相关工作背景和已发表的主要研究结果,展望该领域发展前景,预测"嘎嘣脆"受体在疾病治疗中的可能应用.展开更多
Background Increased levels of plasma lipopolysaccharide （LPS） have been found in obesity and diabetes patients. This study was to investigate the effect of LPS on pancreatic beta-cell viability and the involvement ...Background Increased levels of plasma lipopolysaccharide （LPS） have been found in obesity and diabetes patients. This study was to investigate the effect of LPS on pancreatic beta-cell viability and the involvement of caspase 3 in NIT-1 cell line. Methods Mouse insulinoma NIT-1 cells were treated with LPS for the indicated time and dose. Cell viability was measured by cell counting kit-8 reagent. Toll-like receptor 4 （TLR4）, caspase 3 and cleaved caspase 3 were detected by Western blotting. Insulin was determined by radioimmunoassay （RIA）. Results LPS promoted NIT-1 cell proliferation at 1 μg/ml, peaked at 72 hours of incubation. A reduction in cleavage of caspase 3 was observed upon LPS treatment. Bay11-7082, a specific inhibitor of nuclear factor （NF）-κB, blunted LPS-induced inhibition of caspase 3 cleavage. Reduction in chronic insulin secretion was observed after treatment with LPS at 1 μg/ml for 48 and 72 hours, not for 24 hours. TLR4 protein was upregulated when NIT-1 cells were treated with LPS at 1 μg/ml for 24 hours. Conclusions LPS promotes early NIT-1 cell proliferation in association with NF-KB-mediated inhibition of caspase 3 cleavage. LPS exerts a time-dependent inhibitory effect on chronic insulin secretion from NIT-1 cells.展开更多
文摘光敏剂磺酸化铝络酞菁(SALPC)光动力作用所产生的单线态氧分子(1O2),永久性激活分离大鼠胰腺腺泡细胞内源性的和在HEK293细胞异源表达的胆囊收缩素1型受体(cholecystokinin type 1 receptor, CCK1R).基因编码的蛋白质光敏剂(genetically encoded protein photosensitiser, GEPP)毒杀红(KillerRed)、迷你单(miniSOG)在胰腺腺泡肿瘤细胞系AR4-2J质膜定位表达后,光动力永久激活AR4-2J细胞内源性CCK1R.细胞特异性KillerRed或miniSOG光动力作用,有望为阐述CCK1R的生理功能提供直接证据.潜在"嘎嘣脆"受体嵌合体的出现,将可实现对其他G蛋白偶联受体的在体原位远程调控.本文综述了实验室发现"嘎嘣脆"受体(可被1O2永久性激活的G蛋白偶联受体)的相关工作背景和已发表的主要研究结果,展望该领域发展前景,预测"嘎嘣脆"受体在疾病治疗中的可能应用.
基金This work was supported by grants from the National Natural Science Foundation of China （No. 30671974 and 81070598）. The authors declare no conflict of interest.
文摘Background Increased levels of plasma lipopolysaccharide （LPS） have been found in obesity and diabetes patients. This study was to investigate the effect of LPS on pancreatic beta-cell viability and the involvement of caspase 3 in NIT-1 cell line. Methods Mouse insulinoma NIT-1 cells were treated with LPS for the indicated time and dose. Cell viability was measured by cell counting kit-8 reagent. Toll-like receptor 4 （TLR4）, caspase 3 and cleaved caspase 3 were detected by Western blotting. Insulin was determined by radioimmunoassay （RIA）. Results LPS promoted NIT-1 cell proliferation at 1 μg/ml, peaked at 72 hours of incubation. A reduction in cleavage of caspase 3 was observed upon LPS treatment. Bay11-7082, a specific inhibitor of nuclear factor （NF）-κB, blunted LPS-induced inhibition of caspase 3 cleavage. Reduction in chronic insulin secretion was observed after treatment with LPS at 1 μg/ml for 48 and 72 hours, not for 24 hours. TLR4 protein was upregulated when NIT-1 cells were treated with LPS at 1 μg/ml for 24 hours. Conclusions LPS promotes early NIT-1 cell proliferation in association with NF-KB-mediated inhibition of caspase 3 cleavage. LPS exerts a time-dependent inhibitory effect on chronic insulin secretion from NIT-1 cells.
