• 대한수의학회지
• /
• 제39권3호
• /
• pp.538-544
• /
• 1999

To elucidate the involvement of interleukin-$1{\beta}$ converting enzyme (ICE) in the course of experimental autoimmune encephalomyelitis (EAE), we induced EAE by immunizing rats with an emulsion of rat spinal cord homogenate with complete Freund's adjuvant supplemented with Mycobacterium tuberculosis (H37Ra, 5mg/ml) and then examined the expression of ICE in the spinal cord of rats with EAE. In normal rat spinal cords, ICE is constitutively, but weakly, expressed in ependymal cells, neurons, and some neuroglial cells. In EAE, many inflammatory cells are positive for ICE, and the majority of ICE+ cells were identified as ED1+ macrophages. During this stage of EAE, the number of ICE+ cells in brain cells, including neurons and astrocytes, increased and these cells also had increased ICE immunoreactivity. These findings suggest that the upregulation of ICE in both brain cells and invading hematogenous cells is stimulated by a secretory product from inflammatory cells, and that this enzyme is involved in the pathogenesis of EAE via the production of IL-1 beta.

• Journal of Microbiology and Biotechnology
• /
• 제15권2호
• /
• pp.269-273
• /
• 2005

Five dibenzylbutyrolactones were isolated from a methanol extract of Arctii fructus (Arctium lappa L.) by bioassay-guided isolation, using the interleukin-l $\beta$ converting enzyme (caspase-l, ICE) production inhibitory assay in vitro. These compounds were spectroscopically identified as lappaol E (1), lappaol A (2), matairesinol (3), arctigenin (4), and arctiin (5). Among the compounds tested, arctigenin (4) showed the strongest inhibitory activity for ICE production in IL-$\beta$-induced proliferation of D 1 OS cells. Western blot analysis demonstrated that the arctigenin suppressed the expression of ICE protein in a dose-dependent manner. To estimate the biotransformation of Arctii fructus in vivo by human intestinal bacteria, we carried out an anaerobic incubation of the Arctii fructus extract with a human fecal suspension. From the HPLC analysis of metabolites, Arctiin (IC$_{50}$=74.2$\mu$g/ml), a major component of Arctii fructus, was transformed to aglycone, arctigenin (IC$_{50}$=12.5$\mu$g/ml), by human intestinal bacteria. The ICE production inhibitory activity of Arctii fructus would be much stronger in vivo than in vitro due to the biotransformation by human intestinal bacteria.

• Biomolecules & Therapeutics
• /
• 제23권1호
• /
• pp.31-38
• /
• 2015

Histone acetylation plays a critical role in the regulation of transcription by altering the structure of chromatin, and it may influence the resistance of some tumor cells to tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) by regulating the gene expression of components of the TRAIL signaling pathway. In this study, we investigated the effects and molecular mechanisms of trichostatin A (TSA), a histone deacetylase inhibitor, in sensitizing TRAIL-induced apoptosis in Caki human renal carcinoma cells. Our results indicate that nontoxic concentrations of TSA substantially enhance TRAIL-induced apoptosis compared with treatment with either agent alone. Cotreatment with TSA and TRAIL effectively induced cleavage of Bid and loss of mitochondrial membrane potential (MMP), which was associated with the activation of caspases (-3, -8, and -9) and degradation of poly (ADP-ribose) polymerase (PARP), contributing toward the sensitization to TRAIL. Combined treatment with TSA and TRAIL significantly reduced the levels of the cellular Fas-associated death domain (FADD)-like interleukin-$1{\beta}$-converting enzyme (FLICE) inhibitory protein (c-FLIP), whereas those of death receptor (DR) 4, DR5, and FADD remained unchanged. The synergistic effect of TAS and TRAIL was perfectly attenuated in c-$FLIP_L$-overexpressing Caki cells. Taken together, the present study demonstrates that down-regulation of c-FLIP contributes to TSA-facilitated TRAIL-induced apoptosis, amplifying the death receptor, as well as mitochondria-mediated apoptotic signaling pathways.