Involvement of caspases in apoptotic cell death of murine macrophages infected with Actinobacillus actinomycetemcomitans

Koji Nonaka, Akira Ishisaki, Nobuo Okahashi, Takeyoshi Koseki, Satsuki Kato, Miyuki Muro, Keisuke Nakashima, Tatsuji Nishihara, Yusuke Kowashi

Research output: Contribution to journalArticlepeer-review

14 Citations (Scopus)

Abstract

Infection of murine macrophages in vitro with periodontopathic bacterium Actinobacillus actinomycetemcomitans induces apoptotic cell death. In this study, we investigated the involvement of caspases in apoptotic cell death of A. actinomycetemcomitans-infected macrophages. Two peptide inhibitors of caspases, benzyloxycarbonyl-Val-Ala-Asp (OMe)-fluoromethyl ketone (Z-VAD-FMK) and benzyloxycarbonyl-Asp-Glu-Val-Asp (OMe)-fluoromethyl ketone (Z-DEVD-FMK), inhibited apoptotic cell death of murine macrophage cell line J774.1 infected with A. actinomycetemcomitans. During the process of apoptosis, interleukin-1β (IL-1β) was detected in the culture supernatants of J774.1 cells. IL-1β secretion was blocked by the caspase-1 inhibitor, Z-VAD-FMK, indicating that caspase-1 is involved in not only the induction of apoptosis but also the IL-1β secretion from A. actinomycetemcomitans-infected J774.1 cells. Immunoblot analysis revealed that the infection of A. actinomycetemcomitans to J774.1 cells induced the cleavage of retinoblastoma protein (Rb), suggesting that caspase-3 was activated by A. actinomycetemcomitans infection. The cytosol from A. actinomycetemcomitans-infected J774.1 cells induced Rb proteolysis in vitro, which was inhibited by the caspase-3 inhibitor, Z-DEVD-FMK. Furthermore, caspase-3-like activity was markedly increased in J774.1 cells infected with A. actinomycetemcomitans between 12 h and 24 h, which was subsequently inhibited by the addition of caspase-3 inhibitor, Z-DEVD-FMK. These findings indicate that caspase-3 induces apoplosis in J774.1 cells infected with A. actinomycetemcomitans. Taken together, these results suggest that caspase-1 and caspase-3 are involved in the induction of apoptosis in A. actinomycetemcomitans-infected macrophages.

Original languageEnglish
Pages (from-to)40-47
Number of pages8
JournalJournal of Periodontal Research
Volume36
Issue number1
DOIs
Publication statusPublished - 2001 Feb
Externally publishedYes

Keywords

  • Actinobacillus actinomycetemcomitans
  • Apoptosis
  • Caspase
  • Macrophages

ASJC Scopus subject areas

  • Periodontics

Fingerprint Dive into the research topics of 'Involvement of caspases in apoptotic cell death of murine macrophages infected with Actinobacillus actinomycetemcomitans'. Together they form a unique fingerprint.

Cite this