Original Article

Efflux of potassium ion is an important reason of HL-60 cells apoptosis induced by tachyplesin

Hai-tao Zhang, Jun Wu, Hai-feng Zhang, Qi-feng Zhu

Abstract

Aim: To investigate the role of intercellular potassium in tachyplesin-induced HL-60 cells apoptosis.
Methods: The concentration of intercellular potassium, cell volume and mitochondrial membrane potential were examined by flow cytometry.
Results: The concentration of intercellular potassium reduced in a time-dependent manner in tachyplesin-treated HL-60 cells. In addition, the loss of mitochondrial membrane potential was tightly coupled with the shrinkage of cell volume. Different caspase inhibitors protected against DNA degradation but did not prevent the loss of HL-60 cell viability induced by tachyplesin. Ba2+, which was a kind of blocker of volume-regulatory K+ channels, increased the viability of tachyplesin-treated HL-60 cells and maintained mitochondrial membrane potential and cell volume.
Conclusion: Efflux of K+ was an important reason for apoptosis in tachyplesin-treated HL-60 cells. Efflux of K+ affected the viability of tachyplesin-treated HL-60 cells independent of the process of caspase activation.
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