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Cyclosporine inhibited calcium-mediated apoptosis of HL-60 cells
Insights
Cyclosporine (Cyc) inhibits apoptosis in HL-60 cells only when it is induced by increased intracellular calcium. This suggests distinct mechanisms for apoptosis triggered by calcium-increasing agents versus others like harringtonine or camptothecin.
Area of Science:
- Cell Biology
- Pharmacology
Background:
- Apoptosis, or programmed cell death, is a critical cellular process.
- Understanding the modulators of apoptosis is crucial for developing targeted therapies.
Purpose of the Study:
- To investigate the impact of cyclosporine (Cyc) on apoptosis in HL-60 cells.
- To determine if Cyc affects apoptosis induced by various agents and explore the role of intracellular calcium.
Main Methods:
- HL-60 cells were induced to undergo apoptosis using harringtonine (Har), camptothecin (Cam), calcimycin (Cal), or thapsigargin (Tha).
- Apoptosis was assessed via DNA electrophoresis, cell morphology, and flow cytometry.
- Intracellular calcium levels ([Ca2+]i) in apoptotic cells were measured using flow cytometry.
Main Results:
- Calcimycin (Cal) and thapsigargin (Tha) induced apoptosis in HL-60 cells, accompanied by an increase in intracellular calcium.
- Cyclosporine (Cyc) at a nontoxic concentration inhibited apoptosis induced by Cal and Tha.
- Cyc did not affect apoptosis induced by Har or Cam, which did not alter intracellular calcium levels.
Conclusions:
- Cyclosporine (Cyc) selectively inhibits apoptosis in HL-60 cells when the process is mediated by increased intracellular calcium.
- The mechanisms of apoptosis induced by calcium-increasing agents (Cal, Tha) differ from those induced by Har or Cam.
Aim:
To study the effects of cyclosporine (Cyc) on apoptosis of HL-60 cells.
Methods:
Apoptotic cells induced by harringtonine (Har), camptothecin (Cam), or calcimycin (Cal), thapsigargin (Tha) were identified with DNA electrophoresis, morphology, and flow cytometry. Relative [Ca2+]i alteration of apoptotic HL-60 cells were determined with flow cytometry.
Results:
Cal 1 mg.L-1 or Tha 0.5 mg.L-1 induced apoptosis of HL-60 cells. This effect was inhibited by nontoxic concentration of Cyc 1 mg.L-1. Cyc did not inhibit Har- or Cam-induced apoptosis of HL-60 cells. Both Cal and Tha increased intracellular calcium, whereas Har or Cam did not.
Conclusion:
Cyc inhibited apoptosis only induced by calcium increasement in HL-60 cells. The mechanism of apoptosis induced by Cal or Tha was different from that by Har or Cam.