Increase of ceramides and its inhibition by catalase during chemically induced apoptosis of HL-60 cells determined by electrospray ionization tandem mass spectrometry

A change in all ceramide species during chemically induced apoptosis of HL- 60 cells was determined using electrospray tandem mass spectrometry. Cerami des of C16:0, C24:1 and C26:1 increased significantly 4 h after the additio n of actinomycin D, when the activation of caspase-3 was maximal. Addition of catalase, which inhibited apoptosis, the activation of caspase-3-like pr otease, and the release of cytochrome c from mitochondria to cytosol caused by actinomycin D or daunorubicin, significantly inhibited the increase of these ceramides at all time points. Ceramides of C16:0, C24:1, C18:0, C22:1 and C26:1 increased significantly 4 h after the addition of daunorubicin t o HL-60 cells. Catalase also significantly inhibited the increase of these ceramides induced by daunorubicin. Based on time courses of events and inhi bition studies, it is concluded that the increase of ceramides is downstrea m from both generation of hydrogen peroxide and cytochrome c release from m itochondria and takes place almost simultaneously with the activation of ca spase-3. (C) 2001 Elsevier Science B.V. All rights reserved.