Concanavalin A-induced apoptosis in murine macrophages through a Ca2+-independent pathway
Publication in refereed journal



摘要Concanavalin A (ConA), normally a mitogen of T lymphocytes, was found to induce apoptosis or programmed cell death in murine peritoneal macrophages. The following observations support this assertion: 1) incubation of peritoneal macrophages or cultured PU5-1.8 macrophage cells with ConA caused a dose- and time-dependent reduction of mitochondrial dehydrogenase activity as measured by 3-(4,5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay, 2) treatment of cells with ConA induced formation of apoptotic bodies as seen under the confocal laser scanning microscope, 3) challenge of cells with ConA produced a considerable amount of cell debris with DNA content next to G0 phase as revealed by flow cytometry and 4) ConA was able to elicit DNA fragmentation in these cells, The involvement of Ca2+ in mediating the apoptosis was studied in single cells by confocal laser scanning microscope using the Ca2+ fluorescence dye, fluo-3. Our results show that ConA induced an immediate rise of intracellular free Ca2+ concentration as well as opening of Ca2+ channels on cell surface. But when the cells were treated with 1,2-bis(o-aminophenoxy) ethane-N,N,N',N'-tetraacetic acid/AM (BAPTA/AM), a Ca2+ chelator, to buffer the rise of internal Ca2+, ConA still caused DNA fragmentation, Furthermore, injection of Ca2+ into the cell with ionomycin had no stimulatory effect on DNA fragmentation. These results suggest that Ca2+ changes induced by ConA are not a prerequisite for apoptosis in macrophages.
著者Kong SK, Suen YK, Chan YM, Chan CW, Choy YM, Fung KP, Lee CY
期刊名稱Cell Death and Differentiation
頁次307 - 314
關鍵詞apoptosis; cellular calcium; concanavalin A; macrophage
Web of Science 學科類別Biochemistry & Molecular Biology; BIOCHEMISTRY & MOLECULAR BIOLOGY; Cell Biology; CELL BIOLOGY

上次更新時間 2020-29-07 於 02:39