Acrolein is a highly electrophilic ␣,␤-unsaturated aldehyde to which humans are exposed in various situations. In the present study, the effects of sublethal doses of acrolein on nuclear factor B (NF-B) activation in A549 human lung adenocarcinoma cells were investigated. Immediately following a 30-min exposure to 45 fmol of acrolein/cell, glutathione (GSH) and DNA synthesis and NF-B binding were reduced by more than 80%. All parameters returned to normal or supranormal levels by 8 h post-treatment. Pretreatment with acrolein completely blocked 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced activation of NF-B. Cells treated for 1 h with 1 mM diethyl maleate (DEM) showed a 34 and 53% decrease in GSH and DNA synthesis, respectively. DEM also reduced NF-B activation by 64% at 2 h posttreatment, with recovery to within 22% of control at 8 h. Both acrolein and DEM decreased NF-B function ϳ50% at 2 h after treatment with TPA, as shown by a secreted alkaline phosphatase reporter assay. GSH returned to control levels by 8 h after DEM treatment, but proliferation remained significantly depressed for 24 h. Interestingly, DEM caused a profound decrease in NF-B binding, even at doses as low as 0.125 mM that had little effect on GSH. Neither acrolein nor DEM had any effect on the levels of phosphorylated or nonphosphorylated inhibitor B-␣ (IB-␣). Furthermore, acrolein decreased NF-B activation in cells depleted of IB-␣ by TPA stimulation in the presence of cycloheximide, demonstrating that the decrease in NF-B activation was not the result of increased binding by the inhibitory protein. This conclusion was further supported by the finding that acrolein modified NF-B in the cytosol prior to chemical dissociation from IB with detergent. Together, these data support the conclusion that the inhibition of NF-B activation by acrolein and DEM is IB-independent. The mechanism appears to be related to direct modification of thiol groups in the NF-B subunits.

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Cardiac transplant is hindered by donor shortage and preservation time. Extended extracorporeal preservation could increase the number and distribution of hearts for transplantation. Interestingly, mammalian hibernation biology closely parallels the altered cardiac cellular physiology noted with hypothermic organ storage. The present study undertook to test whether treatment with hibernation induction triggers could improve myocardial functional recovery following prolonged ischemic storage in a nonhibernating mammalian model. To study this hypothesis, isolated rabbit hearts had baseline functional and metabolic parameters recorded and then received either hypothermic storage only or standard cardioplegia, or cardioplegia containing 1 mg/kg D-Ala2-Leu5-enkaphalin (DADLE), which mimics natural hibernation, or preperfusion with DADLE, administered for 15 min at 2 mmol, 25 min prior to cardioplegic ischemia. Hearts were then subjected to 18 hr of global ischemic storage at 4 degrees C. Isovolumic developed pressure, coronary flows, and myocardial oxygen consumption were significantly improved with DADLE pretreatment vs. all groups after storage and reflow. Furthermore, DADLE hearts demonstrated better histological ultrastructure preservation following prolonged storage ischemia. This study demonstrates that hibernation protection with DADLE is beneficial for prolonged cardiac storage. The use of hibernation induction triggers is promising for organ preservation and deserve further mechanistic study.

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