Characteristics of Mitochondrial Events in Synthetic Bile Acids-induced Apoptosis of Human Osteosarcoma Cells / 체질인류학회지

ABSTRACT: Apoptosis of osteosarcoma cells induced by bile duct derivates, HS-1200 was investigated with relation to mitochodria. HS-1200 induced cytochrome c and Smac/DIABLO release from mitochondria which are major factors related to apoptosis. In these apoptosis processes, release of cytochrome c was not blocked by caspase inhibitor, but release of Smac/DIABLO was blocked. BKA, a kind of PTP (permeablity transition pore) inhibitor, did not block both of them. Interestingly, the alteration of MMP was not observed by means of using JC-1 dye. Although MitoTracker, DiOC-6 and Rhodamine123 were used to confirm previous results, the decrease of MMP was not observed. In order to investigate whether this phenomenon is apoptosis-specific or cell-specific process, genistein was added to cells which usually decreased MMP. After adding genistein, MMP was not decreased, suggesting this phenomenon is cell-specific process. Conclusionally, HS-1200 induced apoptosis of osteosarcoma cells via mitochondria, cytochrome c and Smac/DIABLO were released from mitochondria without decrease of MMP. The release of Smac/DIABLO was dependent of caspase.

The Study on the Recognition of Apoptotic Thymocyte by Macrophage / 대한해부학회지

The present study was carried out to investigate the correlation with the sugar specificity of the apoptotic cells and the phagocytosis of the macrophage. Young rat thymocytes were isolated from the thymus and macrophages were isolated from the peritoneal cavity. Isolated thymocytes were treated with dexamethasone to induce apoptosis. After identified the apoptotic cells by TUNEL method, nine kinds of lectins (PSA, UEA I, GSL I B4, ECL, DBA, SBA, DSL, GSL II or WGA) were used to investigate the sugar specificity of the apoptotic thymocyte. And we carried out the phagocytosis assay using the lectin-inhibitory sugars. By TUNEL method, the most numbers of apoptotic thymocytes were observed in the cultured thymocytes treated with 10(-6)M of dexamethasone for 6 hours. From lectin histochemistry, apoptotic thymocyte showed positive reaction with PSA, UEA I, SBA, DSL and WGA, which indicate apoptotic cells have the sugar residues of alpha-D-mannose, alpha-L-fucose, terminal beta-N-acetylgalactosamine and internal beta-1, 4-N-acetylglucosamine oligomers. From phagocytosis assay using cultured thymocytes and macrophages, apoptotic thymocytes of positive reaction with TUNEL method were phagocytosed by macrophage. When the apoptotic thymocytes treated with the lectin-inhibitory sugars were mixed with the macrophages, it was observed that the phagocytosis of macrophages was reduced by methyl-alpha-mannopyranoside and alpha-L-fucose. Considering overall results, it can be assumed that the mannose and fucose may play an important role in the recognition of apoptotic thymocytes by macrophages.