RT Journal Article
SR Electronic
T1 Ethanol Withdrawal Provokes Opening of the Mitochondrial Membrane Permeability Transition Pore in an Estrogen-Preventable Manner
JF Journal of Pharmacology and Experimental Therapeutics
JO J Pharmacol Exp Ther
FD American Society for Pharmacology and Experimental Therapeutics
SP 692
OP 698
DO 10.1124/jpet.108.146829
VO 328
IS 3
A1 Marianna E. Jung
A1 Andrew M. Wilson
A1 Xiaohua Ju
A1 Yi Wen
A1 Daniel B. Metzger
A1 James W. Simpkins
YR 2009
UL http://jpet.aspetjournals.org/content/328/3/692.abstract
AB We have reported that the major endogenous estrogen, 17β-estradiol (E2), protects against oxidative injury during ethanol withdrawal (EW) in a cultured hippocampal cell line (HT22). Here, we investigated whether the pro-oxidant nature of EW mediates opening of the mitochondrial membrane permeability transition pore (PTP) in a manner protected by E2. Excess PTP opening provokes mitochondrial membrane swelling (MMS) and the collapse of membrane potential (ΔΨm). HT22 cells were collected at the end of ethanol exposure (100 mM) for 24 h or at 4 h of EW to assess MMS by monitoring absorbance decline at 540 nm and to assess ΔΨm using flow cytometry. Protective effects of E2 on PTP were compared with an antioxidant butylated hydroxytoluene (BHT) and an E2 analog, ZYC26 [(3-hydroxy-2-adamantyl(1)-4-methyl-estra-1,3,5(10)-17-one], with higher antioxidant potency than E2. To assess cellular consequences of PTP opening, effects of a PTP inhibitor (cyclosporin A) on EW-induced cell death were assessed using the calcein assay. Major findings were that: 1) EW resulted in rapid MMS and ΔΨm collapse; 2) cyclosporin A attenuated EW-induced cell death; and 3) E2 treatment restricted to the EW phase protected against the PTP opening more prominently than BHT and to a similar degree to ZYC26. These findings suggest that EW provokes PTP opening partly but not entirely through the pro-oxidant nature and that E2 counteracts EW-associated factors to protect against the PTP opening. The American Society for Pharmacology and Experimental Therapeutics