Apoptotic changes preceding necrosis in lipopolysaccharide-treated macrophages in the presence of cycloheximide.
Apoptotic changes occurred specifically in a macrophage-like cell line, J774.1, treated with lipopolysaccharide (LPS) and cycloheximide (CHX) prior to the release of lactate dehydrogenase (LDH). The addition of 100 ng/ml LPS and 10 microg/ml CHX induced both the formation of DNA nicks and elevation of caspase-3-like activity (DEVDase) after 75 min, and then the cleavage of poly(ADP-ribose) polymerase (PARP) into 28-kDa fragments, formation of apoptotic bodies, and DNA ladder formation. These apoptotic changes were reversible until 60 min, however, later than 75 min after LPS and CHX addition, the apoptosis proceeded normally even on extensive washing of the macrophages, which removed the LPS and CHX. These results suggest that there is a "point of no return" in the apoptotic processes in macrophages induced by LPS and CHX and that DNA nicks and activation of DEVDase are critical for these processes.
Karahashi
H
H
Department of Biochemistry and Cell Biology, National Institute of Infectious Diseases, 1-23-1 Toyama, Shinjuku-ku, Tokyo, 162, Japan.
Amano
F
F
D000818:Animals; D017209:Apoptosis / Q000187:drug effects / Q000502:physiology*; D053148:Caspase 3; D020169:Caspases; D016923:Cell Death / Q000187:drug effects; D002460:Cell Line; D003513:Cycloheximide / Q000633:toxicity*; D003546:Cysteine Endopeptidases / Q000502:physiology; D004249:DNA Damage / Q000187:drug effects; D004789:Enzyme Activation / Q000187:drug effects; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D008070:Lipopolysaccharides / Q000633:toxicity*; D008264:Macrophages / Q000187:drug effects / Q000473:pathology* / Q000502:physiology*; D051379:Mice; D011500:Protein Synthesis Inhibitors / Q000633:toxicity*
D008070:Lipopolysaccharides; D011500:Protein Synthesis Inhibitors; D003513:Cycloheximide; D007770:L-Lactate Dehydrogenase; C505409:Casp3 protein, mouse; D053148:Caspase 3; D020169:Caspases; D003546:Cysteine Endopeptidases