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


CONCLUSIONS
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.
Zhang
Hai-tao
HT
Institute of Biochemistry and Molecular Biology, Guangdong Medical College, Zhanjiang 524023, China. taohaizhang@tom.com.
Wu
Jun
J
Zhang
Hai-feng
HF
Zhu
Qi-feng
QF
D000590:Amino Acid Chloromethyl Ketones / Q000494:pharmacology; D000890:Anti-Infective Agents / Q000494:pharmacology*; D023181:Antimicrobial Cationic Peptides / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects*; D017609:Barium Compounds / Q000494:pharmacology; D061945:Caspase Inhibitors; D048429:Cell Size / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D002712:Chlorides / Q000494:pharmacology; D053938:DNA Fragmentation / Q000187:drug effects; D004268:DNA-Binding Proteins / Q000494:pharmacology*; D018922:HL-60 Cells; D006801:Humans; D017136:Ion Transport; D008564:Membrane Potentials / Q000187:drug effects; D008928:Mitochondria / Q000502:physiology; D010456:Peptides, Cyclic / Q000494:pharmacology*; D011188:Potassium / Q000378:metabolism*
D000590:Amino Acid Chloromethyl Ketones; D000890:Anti-Infective Agents; D023181:Antimicrobial Cationic Peptides; D017609:Barium Compounds; D061945:Caspase Inhibitors; D002712:Chlorides; D004268:DNA-Binding Proteins; D010456:Peptides, Cyclic; C096713:benzyloxycarbonylvalyl-alanyl-aspartyl fluoromethyl ketone; C024986:barium chloride; C057636:tachyplesin peptide, Tachypleus tridentatus; D011188:Potassium