Isolated Ricin B-Chain-mediated Apoptosis in U937 Cells

Naoko Hasegawa, Yoshinobu Kimura, Tatsuya Oda, Nobukazu Komatsu, Tsuyoshi Muramatsu

Research output: Contribution to journalArticle

23 Citations (Scopus)

Abstract

We have previously reported that ricin a toxic lectin that inhibits protein synthesis induced apoptotic cell death. In this study, we have found that isolated ricin CM-B-chain, which has no effect on cellular protein synthesis, induced DNA fragmentation in U937 cells in a dose- and time-dependent manner, albeit it required a longer incubation time and higher concentration than those of holotoxin ricin. Z-Asp-CH2-DCB, a caspase family inhibitor and serine protease inhibitor, 3,4-dichloroisocoumarine (DCI) effectively inhibited the CM-B-chain-mediated DNA fragmentation as well as in ricin. Thus, like ricin, multiple proteases with different substrate specificity may also be involved in the CM-B-chain-mediated apoptotic pathway. Furthermore, BFA inhibited both ricin- and CM-B-chain-mediated DNA fragmentation, suggesting an intracellular vesicle transport system through the Golgi complex may be involved in the apoptotic induction by these proteins as a common feature. On the other hand, cycloheximide (CHA) strongly increased the CM-B-chain-mediated DNA fragmentation, but inhibited ricin-mediated DNA fragmentation. The opposite effects of CHA may reflect the difference in the apoptotic mechanism between ricin and CM-B-chain. In conclusion, our results suggest that ricin-B-chain can induce apoptosis through its lectin activity, but the underlying mechanism may be distinct from that of ricin in which the A-chain contributes profoundly to the apoptotic induction.

Original languageEnglish
Pages (from-to)1422-1429
Number of pages8
JournalBioscience, Biotechnology and Biochemistry
Volume64
Issue number7
Publication statusPublished - Jul 2000

Fingerprint

ricin
Ricin
U937 Cells
Cell death
DNA
apoptosis
Apoptosis
DNA fragmentation
DNA Fragmentation
Proteins
cells
Lectins
lectins
protein synthesis
Transport Vesicles
Serine Proteinase Inhibitors
Caspase Inhibitors
Poisons
caspases
Golgi Apparatus

Keywords

  • Apoptosis
  • Cytotoxicity
  • Lectin
  • Ricin
  • Ricin B-chain

ASJC Scopus subject areas

  • Food Science
  • Biochemistry, Genetics and Molecular Biology(all)
  • Biochemistry
  • Biotechnology
  • Chemistry (miscellaneous)
  • Applied Microbiology and Biotechnology
  • Bioengineering

Cite this

Hasegawa, N., Kimura, Y., Oda, T., Komatsu, N., & Muramatsu, T. (2000). Isolated Ricin B-Chain-mediated Apoptosis in U937 Cells. Bioscience, Biotechnology and Biochemistry, 64(7), 1422-1429.

Isolated Ricin B-Chain-mediated Apoptosis in U937 Cells. / Hasegawa, Naoko; Kimura, Yoshinobu; Oda, Tatsuya; Komatsu, Nobukazu; Muramatsu, Tsuyoshi.

In: Bioscience, Biotechnology and Biochemistry, Vol. 64, No. 7, 07.2000, p. 1422-1429.

Research output: Contribution to journalArticle

Hasegawa, N, Kimura, Y, Oda, T, Komatsu, N & Muramatsu, T 2000, 'Isolated Ricin B-Chain-mediated Apoptosis in U937 Cells', Bioscience, Biotechnology and Biochemistry, vol. 64, no. 7, pp. 1422-1429.
Hasegawa N, Kimura Y, Oda T, Komatsu N, Muramatsu T. Isolated Ricin B-Chain-mediated Apoptosis in U937 Cells. Bioscience, Biotechnology and Biochemistry. 2000 Jul;64(7):1422-1429.
Hasegawa, Naoko ; Kimura, Yoshinobu ; Oda, Tatsuya ; Komatsu, Nobukazu ; Muramatsu, Tsuyoshi. / Isolated Ricin B-Chain-mediated Apoptosis in U937 Cells. In: Bioscience, Biotechnology and Biochemistry. 2000 ; Vol. 64, No. 7. pp. 1422-1429.
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