Electrophilic fatty acid species inhibit 5-lipoxygenase and attenuate sepsis-induced pulmonary inflammation

Antioxid Redox Signal. 2014 Jun 10;20(17):2667-80. doi: 10.1089/ars.2013.5473. Epub 2014 Feb 3.


Aims: The reaction of nitric oxide and nitrite-derived species with polyunsaturated fatty acids yields electrophilic fatty acid nitroalkene derivatives (NO2-FA), which display anti-inflammatory properties. Given that the 5-lipoxygenase (5-LO, ALOX5) possesses critical nucleophilic amino acids, which are potentially sensitive to electrophilic modifications, we determined the consequences of NO2-FA on 5-LO activity in vitro and on 5-LO-mediated inflammation in vivo.

Results: Stimulation of human polymorphonuclear leukocytes (PMNL) with nitro-oleic (NO2-OA) or nitro-linoleic acid (NO2-LA) (but not the parent lipids) resulted in the concentration-dependent and irreversible inhibition of 5-LO activity. Similar effects were observed in cell lysates and using the recombinant human protein, indicating a direct reaction with 5-LO. NO2-FAs did not affect the activity of the platelet-type 12-LO (ALOX12) or 15-LO-1 (ALOX15) in intact cells or the recombinant protein. The NO2-FA-induced inhibition of 5-LO was attributed to the alkylation of Cys418, and the exchange of Cys418 to serine rendered 5-LO insensitive to NO2-FA. In vivo, the systemic administration of NO2-OA to mice decreased neutrophil and monocyte mobilization in response to lipopolysaccharide (LPS), attenuated the formation of the 5-LO product 5-hydroxyeicosatetraenoic acid (5-HETE), and inhibited lung injury. The administration of NO2-OA to 5-LO knockout mice had no effect on LPS-induced neutrophil or monocyte mobilization as well as on lung injury.

Innovation: Prophylactic administration of NO2-OA to septic mice inhibits inflammation and promotes its resolution by interfering in 5-LO-mediated inflammatory processes.

Conclusion: NO2-FAs directly and irreversibly inhibit 5-LO and attenuate downstream acute inflammatory responses.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Arachidonate 5-Lipoxygenase / metabolism*
  • Fatty Acids, Unsaturated / metabolism*
  • Humans
  • Lipoxygenase Inhibitors / metabolism
  • Mice
  • Neutrophils / metabolism
  • Nitric Oxide / metabolism
  • Pneumonia / drug therapy
  • Pneumonia / etiology
  • Pneumonia / metabolism
  • Pneumonia / pathology*
  • Sepsis / complications
  • Sepsis / drug therapy
  • Sepsis / metabolism
  • Sepsis / pathology*
  • Signal Transduction / genetics


  • Fatty Acids, Unsaturated
  • Lipoxygenase Inhibitors
  • Nitric Oxide
  • Arachidonate 5-Lipoxygenase