Journal of Biochemistry Advance Access originally published online on April 16, 2008
Journal of Biochemistry 2008 144(1):95-106; doi:10.1093/jb/mvn050
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© 2008 The Japanese Biochemical Society
Chemical and Apoptotic Properties of Hydroxy-Ceramides Containing Long-Chain Bases with Unusual Alkyl Chain Lengths
1Division of Molecular Pathology, Aichi Cancer Center Research Institute, 1-1 Kanokoden, Chikusa-ku, Nagoya, Aichi, 464-8681; 2Department of Oncology, Graduate School of Pharmaceutical Sciences, Nagoya City University, 3-1 Tanabe-dori, Mizuho-ku, Nagoya, 467-8603; 3Department of Biochemistry, Teikyo University School of Medicine, 2-11-1 Kaga, Itabashi-ku, Tokyo, 173-8605; 4Department of Metabolic Regulation, Institute on Aging and Adaptation, Shinshu University Graduate School of Medicine, 3-1-1 Asahi, Matsumoto, Nagano, 390-8621; and 5Department of Medical Technology, Nagoya University Graduate School of Health Sciences, 1-1-20, Daiko-Minami, Higashi-ku, Nagoya, Aichi, 461-8673, Japan
*To whom correspondence should be addressed. Tel: +81 52 762 6111, Fax: +81 52 763 5233, E-mail: mkyogashi{at}aichi-cc.jp
Received February 29, 2008; Accepted March 20, 2008
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Abstract |
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We analysed four types of free ceramides (Cer 1, Cer 2, Cer 3 and Cer 4) from equine kidneys by electrospray ionization mass spectrometry. Cer 1 was composed of dihydroxy long-chain bases (dLCBs) of (4E)-sphingenine (d18:1), sphinganine and non-hydroxy fatty acids (NFAs); Cer 2 was composed of trihydroxy LCBs (tLCBs) of 4-hydroxysphinganine, t16:0, t18:0, t19:0 and t20:0, and NFAs; Cer 3 was composed of dLCBs, d16:1, d17:1, d18:1, d19:1 and d20:1, and hydroxy FAs (HFAs); and Cer 4 was composed of tLCBs, t16:0, t17:0, t18:0, t19:0 and t20:0, and HFAs. The results indicate all ceramide species containing LCBs with non-octadeca lengths (NOD-LCBs) can be classified into hydroxy-ceramides since these species always consist of tLCBs, and/or HFAs. Furthermore, such species tend to contain FAs with longer acyl chains but contain neither palmitate (C16:0) nor its hydroxylated form (C16:0h). The apoptosis-inducing activities of these hydroxyl-ceramides towards tumour cell lines were compared with that of non-hydroxy-ceramides, dLCB-NFA (Cer 1). Monohydroxy-ceramides, tLCB-NFA (Cer 2) and dLCB-HFA (Cer 3), exhibited stronger activities, whereas dihydroxy-ceramides, tLCB-HFA (Cer 4), exhibited similar or weaker activity than dLCB-NFA (Cer 1), depending on cell lines.
Key Words: apoptosis, ceramides, hydroxy-ceramides, long-chain bases, mass spectrometry
Abbreviations: C16:0h, C16:0 hydroxy fatty acid; d18:1-C16:0, ceramide possessing d18:1 with C16:0; dLCB, dihydroxy long-chain base; d16:1, (4E)-hexadecasphingenine; d17:1, (4E)-heptadecasphingenine; d18:0, sphinganine; d18:1, (4E)-sphingenine; d19:1, (4E)-nonadecasphingenine; d20:1, (4E)-icosasphingenine; ESI, electrospray ionization; HFA, hydroxy fatty acid; HPTLC, high performance thin-layer chromatography or chromatogram; MS, mass spectrometry; NFA, non-hydroxy fatty acid; NOD-LCBs, non-octadeca LCB; OD-LCBs; octadeca LCBs; PARP, poly ADP-ribose polymerase; 7-AAD, 7-amino-actinomycin D; tLCB; trihydroxy LCB; t16:0, 4D-hydroxyhexadecasphinganine; t17:0, 4D-hydroxyheptadecasphinganine; t18:0, 4D-hydroxysphinganine or phytosphingosine; t19:0, 4D-hydroxynonadecasphinganine; t20:0, 4D-hydroxyicosasphinganine