Related Experiment Videos
Cyclooxygenase inhibitors decrease apoptosis initiated by actinomycin D, cycloheximide, and staurosporine in
R M Moore1, D W Lundgren, J J Moore
1Department of Pediatrics, Case Western Reserve University School of Medicine, Cleveland, Ohio, USA.
Abstract:
Apoptosis is a process by which external or developmental factors induce a specific series of events leading to cell death. Recently, apoptotic cells have been described in rat amnion membrane at late gestation, suggesting apoptosis may be involved in membrane rupture. Mechanisms controlling amnion cell apoptosis are unknown. The objective of this study was to investigate whether cyclooxygenase and prostaglandins are integral to apoptosis in amnion, as reported in intestinal epithelial cells and renal mesangial cells. Amnion-derived WISH cells underwent apoptosis in a dose- and time-dependent manner after incubation with actinomycin D, cycloheximide, or staurosporine, as determined by cell viability, DNA fragmentation analysis, and fluorescent in situ fragmentation analysis. Cells cultured with increasing doses of these agents also demonstrated concomitant increases in prostaglandin E2 output. WISH cell coincubation with these agents and the cyclooxygenase inhibitors indomethacin or piroxicam resulted in dose-dependent decreases in both prostaglandin E2 and apoptosis. Cultures incubated with 0.5 microgram/mL actinomycin D showed 80.7% cell apoptosis after 12 hours compared with 1.1% in untreated cultures. After 24 hours incubation with actinomycin D, 0.8% of the original cell number remained attached to the plate. In cultures coincubated with 0.5 microgram/mL actinomycin D and 100 mumol/L indomethacin, only 19.2%, 24.7%, and 39.3% of the cells were found to be apoptotic after 12, 24, and 48 hours in culture, respectively. Similar trends were observed after the use of cycloheximide or staurosporine in combination with indomethacin or prioxicam. These data suggest that cyclooxygenase and/or prostaglandins play a role in programmed cell death of amnion-derived WISH cells in culture.
Insights
Cyclooxygenase (COX) and prostaglandins are involved in programmed cell death (apoptosis) in amnion cells. Inhibiting COX reduces apoptosis, suggesting a role in amnion membrane function.
Area of Science:
- Cell Biology
- Biochemistry
Background:
- Apoptosis, or programmed cell death, is crucial for development and tissue homeostasis.
- Apoptotic cells have been observed in the amnion membrane, hinting at a role in membrane rupture.
- The molecular mechanisms regulating amnion cell apoptosis remain largely unknown.
Purpose of the Study:
- To investigate the role of cyclooxygenase (COX) and prostaglandins in amnion cell apoptosis.
- To determine if COX and prostaglandins are integral to apoptosis in amnion cells, similar to their roles in intestinal and renal cells.
Main Methods:
- Amnion-derived WISH cells were treated with apoptosis-inducing agents (actinomycin D, cycloheximide, staurosporine).
- Apoptosis was assessed using cell viability assays, DNA fragmentation analysis, and fluorescent in situ fragmentation analysis.
- Prostaglandin E2 (PGE2) output was measured, and the effects of COX inhibitors (indomethacin, piroxicam) were evaluated.
Main Results:
- WISH cells exhibited dose- and time-dependent apoptosis upon treatment with apoptosis-inducing agents.
- Treatment with these agents increased PGE2 production.
- Co-incubation with COX inhibitors significantly reduced both PGE2 levels and apoptosis.
- Specific data showed a marked decrease in apoptosis when COX inhibitors were used alongside actinomycin D.
Conclusions:
- Cyclooxygenase and prostaglandins play a significant role in regulating programmed cell death in cultured amnion cells.
- These findings suggest a potential mechanism for amnion membrane rupture involving COX and prostaglandin pathways.