No abstract

Lipid oxidation is implicated in a wide range of pathophysiogical disorders, and leads to reactive compounds such as fatty aldehydes, of which the most well known is 4-hydroxy-2 E-nonenal (4-HNE) issued from 15-hydroperoxyeicosatetraenoic acid (15-HpETE), an arachidonic acid (AA) product. In addition to 15-HpETE, 12(S)-HpETE is synthesized by 12-lipoxygenation of platelet AA. We first show that 12-HpETE can be degraded in vitro into 4-hydroxydodeca-(2 E ,6 Z )-dienal (4-HDDE), a specific aldehyde homologous to 4-HNE. Moreover, 4-HDDE can be detected in human plasma. Second, we compare the ability of 4-HNE, 4-HDDE, and 4-hydroxy-2 E -hexenal (4-HHE) from n-3 fatty acids to covalently modify different ethanolamine phospholipids (PEs) chosen for their biological relevance, namely AA-(20: 4n-6) or docosahexaenoic acid-(22:6n-3) containing diacyl-glycerophosphoethanolamine (diacyl-GPE) and alkenylacyl-glycerophosphoethanolamine (alkenylacyl-GPE) molecular species. The most hydrophobic aldehyde used, 4-HDDE, generates more adducts with the PE subclasses than does 4-HNE, which itself appears more reactive than 4-HHE. Moreover, the aldehydes show higher reactivity toward alkenylacyl-GPE compared with diacyl-GPE, because the docosahexaenoyl-containing species are more reactive than those containing arachidonoyl. We conclude that the different PE species are differently targeted by fatty aldehydes: the higher their hydrophobicity, the higher the amount of adducts made. In addition to their antioxidant potential, alkenylacyl-GPEs may efficiently scavenge fatty aldehydes. Supplementary key words 4-hydroxydodeca-(2 E ,6 Z )-dienal • 4-hydroxy-2 E -hexenal • 4-hydroxy-2 E -nonenal

Ann M. Stevens (left) and Susanne von Bodman (right) have been research collaborators since 2001 but have known each other since their days at the University of Illinois. In 1993, Ann earned her Ph.D. from the Department of Microbiology at the University of Illinois at Urbana-Champaign in the laboratory of Abigail A. Salyers. For the next fours year, she served as a postdoctoral research associate under the supervision of E. Peter Greenberg, then in the Department of Microbiology at the University of Iowa. This is where she began studying aspects of QS in Vibrio fischeri. In 1997, she began a faculty position at Virginia Tech in the Department of Biological Sciences as an assistant professor and was promoted with tenure to the level of associate professor in 2004 and full professor in 2010. Research in her laboratory is currently focused on QS in the Vibrios and in the plant pathogen Pantoea stewartii; the latter work is done in cooperation with the von Bodman group. Susanne earned her Ph.D. from