Signaling for ethanol-induced apoptosis and repair in vitro.
OBJECTIVE
To evaluate whether caspases are involved in ethanol (EtOH)-induced apoptosis and if polyenylphosphatidylcholine (PPC) affects apoptosis, in vitro in Hep G2 cells.


METHODS
Cells were treated with 100 mmol/L EtOH for 24 h and with 2 doses of 100 mmol/L EtOH (1/24 h) in the presence of absence of 20 mmol/L of PPC or 50 micromol/L caspase 3 inhibitor (IDN). Cells were analyzed for apoptosis by transmission electron microscopy (TEM) 6000 cells/treatment, DNA fragmentation by ELISA and terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate (T dt-mediated d-UTP) nick-end-labeling, TUNEL.


RESULTS
100 mmol/L dose of EtOH resulted in 22 +/- 2.5% (p < 0.001) apoptosis (vs. control). Two consecutive doses of 100 mmol/L EtOH for 24 h each caused 36 +/- 3.0% (p < 0.001 vs. control and p < 0.05 vs. one dose). PPC significantly reduced apoptosis (vs. non exposed to PPC): 100 mmol/L -12 +/- 1.5% (p < 0.05) and 2 x 10(-)(0) mmol/L -20 +/- 2.0% (p < 0.001). Pretreatment with 50 micromol caspase inhibitor reduced EtOH-induced apoptosis in a similar proportion.


CONCLUSIONS
PPC downregulates EtOH-apoptosis by a mechanism similar to caspase inhibition.
Katz
G G
GG
Division of Clinical Pharmacology, Sunnybrook & Women's College Health Sciences Centre, Toronto, Canada.
Shear
N H
NH
Malkiewicz
I M
IM
Valentino
K
K
Neuman
M G
MG
D017209:Apoptosis / Q000187:drug effects*; D020169:Caspases / Q000378:metabolism*; D002460:Cell Line; D004260:DNA Repair / Q000187:drug effects*; D004797:Enzyme-Linked Immunosorbent Assay; D000431:Ethanol / Q000494:pharmacology*; D022781:Hepatocytes / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D006801:Humans; D020287:In Situ Nick-End Labeling; D008854:Microscopy, Electron; D015398:Signal Transduction
D000431:Ethanol; D020169:Caspases