Polychlorinated biphenyls activate caspase-3-like death protease in vitro but not in vivo.
We prove here that serum albumin inhibits apoptosis induced by polychlorinated biphenyls (PCBs), confirming that serum albumin binds to PCB, and that the albumin-PCB complexes inhibit apoptosis in HL-60 cells. We found that PCB (50 microM) increased the activity of caspase-3-like protease when HL-60 cells, as well as splenocytes, were cultured in "serum-free medium." Benzyloxycarbonyl-Val-Ala-Asp-fluoromethylketone (Z-VAD-fmk) inhibited apoptosis in cells cultured in the serum-free medium containing 50 microM PCB. To elucidate whether or not PCBs induce apoptosis in vivo, we examined apoptosis of splenocytes by administering PCB to ICR mice (100, 500, 1000 mg x kg(-1) x d(-1)) for 5 d and characterizing splenocytes. Interestingly, splenocytes treated with PCB did not show any changes characteristic of apoptosis. These results demonstrate that PCB activates the caspase-3-like death protease in vitro in serum-free medium, but does not induce apoptosis of splenocytes in vivo, suggesting that blood serum may mask the apoptosis induced by PCB.
Lee
S H
SH
Biopotency Evaluation Lab, Korea Research Institute of Bioscience and Biotechnology, Taejon.
Youk
E S
ES
Jeon
Y J
YJ
Han
S B
SB
Kim
H C
HC
Kim
H M
HM
D000818:Animals; D017209:Apoptosis / Q000187:drug effects* / Q000502:physiology; D053148:Caspase 3; D020169:Caspases / Q000378:metabolism*; D016923:Cell Death / Q000187:drug effects / Q000502:physiology; D004785:Environmental Pollutants / Q000008:administration & dosage* / Q000494:pharmacology*; D004789:Enzyme Activation / Q000187:drug effects / Q000502:physiology; D018922:HL-60 Cells; D006801:Humans; D007274:Injections, Intraperitoneal; D051379:Mice; D008810:Mice, Inbred C57BL; D008811:Mice, Inbred DBA; D008813:Mice, Inbred ICR; D011078:Polychlorinated Biphenyls / Q000008:administration & dosage* / Q000494:pharmacology*; D013154:Spleen / Q000166:cytology / Q000187:drug effects / Q000201:enzymology
D004785:Environmental Pollutants; D011078:Polychlorinated Biphenyls; C505407:CASP3 protein, human; C505409:Casp3 protein, mouse; D053148:Caspase 3; D020169:Caspases