[The effect of p38 on the cycloheximide-induced HL-60 cell death through mitochondria pathway].
OBJECTIVE
To study the effect of p38 on the cycloheximide (CHX)-induced HL-60 cell death through mitochondria pathway.


METHODS
Inhibition of p38 pathway was by SB203580 (SB). Four groups were set up: control, SB only, CHX only and SB + CHX. Sub-diploid cell ratio was detected by PI staining flow cytometry at 6, 9, 12, 18, 24 h time points, and apoptotic cell ratio by Annexin V-FITC/PI double staining flow cytometry at 6 h and 18 h time points. High J-aggregate cells were evaluated by the J-aggregate contents, measurement of the J-aggregate (FL2) and J-monomer (FL1) by JC-1 flow cytometry, calculation of the delta psi m by FL2/FL1 and analysis of the delta psi m changes at 18 h time points.


RESULTS
The sub-diploid cell ratio in CHX group was significantly higher than that in control group at 6 h time point, and the ratio in SB + CHX group was significantly higher than that in CHX group at 9 h time point. At 18 h time point the apoptotic cell ratios in both CHX and SB + CHX groups were significantly higher than those in control group (P < 0.01). There was no significant difference of apoptotic cell ratio between CHX group and SB + CHX group (P > 0.05). At 18 h time point the necrotic cell ratios in both CHX and SB + CHX groups were significantly higher than that in control group (P < 0.01); and that in SB + CHX group was significantly higher than that in CHX group (P < 0.01). The high J-aggregate cell ratios in CHX and SB + CHX groups were significantly lower than that in control group (P < 0.05), and that was signficantly lower in SB + CHX group than in CHX group (P < 0.01). For the FL2/FL1 value (delta psi m) CHX group (0.17 +/- 0.01) and SB + CHX group (0.05 +/- 0.003) were significantly higher than control group (0.38 +/- 0.02) (P < 0.01), and SB + CHX group was significantly lower than CHX group (P < 0.01).


CONCLUSIONS
CHX can induce HL-60 cell apoptosis and the cell mitochondria depolarization, and the latter was intensified by inhibition of the p38 pathway. p38 pathway may related to the cell necrosis in the cycloheximide-induced HL-60 cell apoptosis model. s
Liang
Pei-yan
PY
Key Laboratory of Tissue Transplantation and Immunology of National Education Dept., Jinan University, Guangzhou 510632, China.
Zeng
Yao-ying
YY
Wang
Tong
T
Xing
Fei-yue
FY
Zhao
Jing-xian
JX
Jiang
Xun
X
Di
Jing-fang
JF
D017209:Apoptosis / Q000187:drug effects*; D003513:Cycloheximide / Q000494:pharmacology; D018922:HL-60 Cells; D006801:Humans; D008564:Membrane Potentials; D008928:Mitochondria / Q000502:physiology*; D048051:p38 Mitogen-Activated Protein Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism*
D003513:Cycloheximide; D048051:p38 Mitogen-Activated Protein Kinases