This mini-review highlights the chemical and cytoprotective properties of various hydralazine analogues that block the induction of cell death by acrolein, a highly toxic contributor to “carbonyl stress” during a diverse range of human diseases. Recent work on the action of hydralazine against various carbonyl-mediated pathologies is also reviewed.

Extensive protein carbonylation accompanies cellular exposure to acrolein, a ubiquitous smoke constituent implicated in life-threatening pulmonary edema in fire victims, a condition involving rapid erosion of the “watertight” properties of respiratory epithelium. Since the identities of lung epithelial proteins that sustain carbonylation by acrolein are unknown, we sought to identify significant targets in subcellular fractions from A549 cells after 30 min exposure to either subtoxic or acutely toxic acrolein concentrations (60 or 360 fmol acrolein/cell). The lower concentration mainly modified cytosolic proteins while the higher concentration also damaged nuclear, membrane, and cytoskeletal proteins. The multifunctional intermediate filament proteins vimentin, keratin-18, keratin-7 and keratin-8, were conspicuous targets. Consistent with their mechanical functions, a loss of cellular adhesive strength accompanied adduction of the two most abundant intermediate filaments in A549 cells, keratins-8 and -18. Acrolein also elicited redistribution of several chaperones (Hsp40, -70, -90, and -110) to intermediate filament fractions, suggesting chaperone-mediated autophagy contributes to the triage of acrolein-adducted proteins. The carbonyl scavenger bisulfite suppressed acrolein toxicity, intermediate filament adduction, vimentin cross-linking, Hsp90 redistribution, and loss of cellular adhesive strength, while also suppressing vimentin hyperphosphorylation. These novel observations identify intermediate filaments as key targets for the reactive smoke constituent acrolein. Antioxid. Redox Signal. 12, 337–347.