Bacterial ceramides and sphingophospholipids induce apoptosis of human leukaemic cells.
The genus Sphingobacterium, whose members are Gram-negative non-fermentative rods, possesses ceramides and related sphingophospholipids (SPLs) with isoheptadecasphinganine and 2-hydroxy or non-hydroxy isopentadecanoic acid. This paper reports evidence that ceramides isolated from Sphingobacterium spiritivorum ATCC 33861 induce endonucleolytic DNA cleavage in human myeloid leukaemia HL-60 cells in vitro, which is the primary characteristic biochemical marker for apoptosis or programmed cell death. Ceramides and SPLs also induced DNA fragmentation and caspase-3 activation, followed by changes in morphology, such as alterations in the size of nuclei and cells, and cell cycle shortening. Apoptotic activity correlated with the ceramide structure. Ceramide with a 2-hydroxy fatty acid showed stronger apoptotic activity than ceramide with a non-hydroxy fatty acid. Furthermore, the major five SPLs (ceramide phosphorylethanolamine-1 and -2, ceramide phosphorylinositol-1 and -2, and ceramide phosphorylmannose-1) showed apoptosis-inducing activity in HL-60 cells, indicating that the ceramide moiety of the SPLs plays a crucial role as the intracellular second messenger but that their hydrophilicity is less important in this regard. The hydrophilic part of SPLs may play a role in other cellular response systems. The involvement of Fas antigen was implicated in the apoptotic event since Fas antigen expression was observed after 3 or 4 h stimulation of HL-60 cells with bacterial ceramides. However, a time-course study for caspase-3 activation indicated maximal activity at 1 h after stimulation with bacterial ceramides, suggesting that two (or possibly more) mechanisms of signal transduction, Fas-dependent and Fas-independent, may be involved. Fas antigen expression and caspase-3 activation by five kinds of SPLs were observed after 3 or 4 h. These results indicate that there is a difference in the response of HL-60 cells to bacterial ceramides and SPLs.
Minamino
Miki
M
Institute of Cosmetic Sciences, Club Cosmetics Co. Ltd, 145-1 Ichibu-cho, Ikoma-shi, Nara 630-0222, Japan.
Sakaguchi
Ikuyo
I
Institute of Cosmetic Sciences, Club Cosmetics Co. Ltd, 145-1 Ichibu-cho, Ikoma-shi, Nara 630-0222, Japan.
Naka
Takashi
T
Institute of Cosmetic Sciences, Club Cosmetics Co. Ltd, 145-1 Ichibu-cho, Ikoma-shi, Nara 630-0222, Japan.
Ikeda
Norikazu
N
Institute of Cosmetic Sciences, Club Cosmetics Co. Ltd, 145-1 Ichibu-cho, Ikoma-shi, Nara 630-0222, Japan.
Kato
Yoshiko
Y
Institute of Cosmetic Sciences, Club Cosmetics Co. Ltd, 145-1 Ichibu-cho, Ikoma-shi, Nara 630-0222, Japan.
Tomiyasu
Ikuko
I
Tezukayama Junior College, 3-1-3 Gakuen-minami, Nara 631-8585, Japan.
Yano
Ikuya
I
Japan BCG Laboratory, 3-1-5 Matsuyama, Kiyose-shi, Tokyo 204-0022, Japan.
Kobayashi
Kazuo
K
Department of Host Defense, Osaka City University Graduate School of Medicine, 1-4-3 Asahi-machi, Abeno-ku, Osaka 545-8585, Japan.
D017209:Apoptosis / Q000187:drug effects*; D053148:Caspase 3; D020169:Caspases / Q000378:metabolism; D002518:Ceramides / Q000737:chemistry / Q000494:pharmacology*; D004789:Enzyme Activation / Q000187:drug effects; D006090:Gram-Negative Bacteria / Q000737:chemistry*; D018922:HL-60 Cells; D006801:Humans; D019169:Jurkat Cells; D015394:Molecular Structure; D015290:Second Messenger Systems; D013107:Sphingolipids / Q000737:chemistry / Q000494:pharmacology*; D020298:U937 Cells; D019014:fas Receptor / Q000378:metabolism
D002518:Ceramides; D013107:Sphingolipids; D019014:fas Receptor; C505407:CASP3 protein, human; D053148:Caspase 3; D020169:Caspases